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10,765,065 | ACCEPTED | Multi-step method of manufacturing a medical device | A multi-step method of manufacturing a medical device containing therapeutic agents that results in a lower maximum error in the amount of therapeutic agents actually disposed thereon and that allows for differential drug release kinetics along the length of the medical device. | 1. A method of manufacturing a medical device comprising a total desired amount of a first and a second therapeutic agent disposed thereon, the method comprising: applying a first desired amount of a first therapeutic agent to a first portion of the medical device; determining a first actual amount of the first therapeutic agent, wherein the first actual amount is the amount of the first therapeutic agent disposed on the first portion of the medical device; and applying a second desired amount of a second therapeutic agent to a second portion of the medical device, wherein the second desired amount equals the difference between the total desired amount and the first actual amount. 2. The method of claim 1, wherein the first portion has a greater surface area than the second portion. 3. The method of claim 1, wherein the first therapeutic agent is disposed in a first coating and the second therapeutic agent is disposed in a second coating. 4. The method of claim 3, wherein the first coating defines a first plurality of reservoirs and the second coating defines a second plurality of reservoirs, the first therapeutic agent being disposed in the first plurality of reservoirs and the second therapeutic agent being disposed in the second plurality of reservoirs. 5. The method of claim 1, wherein the first and the second therapeutic agents comprise different compositions. 6. The method of claim 1, wherein the first and the second therapeutic agents comprise the same compositions. 7. The method of claim 1, wherein the first portion is exposable to a first area of a target site and the second portion is exposable to a second area of a target site, wherein the first and the second therapeutic agents have different release kinetics and wherein the different release kinetics are targeted to anatomical or pathological characteristics of the first area and the second area of the target site. 8. The method of claim 7, wherein the medical device further comprises a first coating in which the first therapeutic agent is disposed and a second coating in which the second therapeutic agent is disposed, wherein the different release kinetics are a result of the first and second coatings having different bioabsorption rates. 9. The method of 8, wherein the first and second coatings are different compositions. 10. The method of claim 7, wherein the anatomical characteristics of the first area and the second area comprises the first area and the second area being exposed to different flow rates. 11. The method of claim 7, wherein the pathological characteristics of the first area and the second area comprises the first area and the second area being in different stages of disease. 12. The method of claim 7, wherein the pathological characteristics of the first area and the second area comprises the first area being diseased and the second area being non-diseased. 13. A method of manufacturing a medical device comprising a desired amount of a positive therapeutic agent disposed thereon, the method comprising: applying a desired amount of a positive therapeutic agent to the medical device; determining an actual amount of the positive therapeutic agent, wherein the actual amount is the amount of the positive therapeutic agent disposed on the medical device; determining if the actual amount of the positive therapeutic agent is greater than the desired amount of the positive therapeutic agent; and applying a negative agent to the medical device if the actual amount of the positive therapeutic agent disposed on the medical device is greater than the desired amount of the positive therapeutic agent, wherein the negative agent has a neutralizing or opposing effect on the positive therapeutic agent. 14. The method of claim 13, wherein the negative agent is a therapeutic agent. 15. The method of claim 13, wherein the negative agent is ultraviolet light. 16. The method of claim 13, wherein the negative agent is heat. 17. The method of claim 13, wherein the negative agent is a conducting electroactive polymer. 18. The method of claim 13, wherein the desired amount of the positive therapeutic agent is encapsulated in microcapsules, the microcapsules further comprising the negative agent, the negative agent being a paramagnetic particle that is capable of causing elimination of the microcapsules upon exposure of the medical device to an external magnetic field. | FIELD OF THE INVENTION The present invention relates to a multi-step method of manufacturing a medical device containing therapeutic agents disposed thereon. BACKGROUND OF THE INVENTION Minimally invasive medical devices such as stents, grafts, and balloon catheters, are used for a number of medical purposes including the treatment of vascular disease, reinforcement of recently re-enlarged lumens, and the replacement of ruptured vessels. It is often beneficial to incorporate in such medical devices, therapeutic agents, which are often contained within a coating applied to the surface of the medical device, to provide desired therapeutic properties and effects. For example, it is useful to apply a coating containing therapeutic agents to medical devices to provide for the localized delivery of therapeutic agents to target locations within the body, such as an occluded body lumen. Compared to systemic drug administration, such localized drug delivery minimizes unwanted effects on parts of the body which are not to be treated and allows for the delivery of higher amounts of therapeutic agent to the afflicted part of the body. Coatings containing therapeutic agents may also provide for controlled release, which includes long-term or sustained release, of the therapeutic agent. Conventionally, coatings have been applied to medical devices by processes such as dipping, spraying, vapor deposition, plasma polymerization, and electro-deposition. Although these processes have been used to produce satisfactory coatings, there are numerous drawbacks associated with these processes. For example, with current spraying processes, it is difficult to achieve a narrow weight distribution of the therapeutic agent on the medical device. Furthermore, the evaporation of solvents used in the coatings, the complex geometries of many medical devices, and the low amounts of therapeutic agents applied to the coatings contribute to the difficulty in measuring the amount of therapeutic agent actually disposed on the medical device. In addition, there is no direct feedback loop associated with these medical devices to ascertain the actual amount of therapeutic agent disposed on the medical device and therefore it is often necessary to maintain processing parameters as constant as possible. However, due to the large number of processing parameters associated with coating a medical device, there is still a significant amount of variation in the amount of drug disposed on the medical device. In addition to the difficulties associated with achieving a narrow weight distribution of a therapeutic agent on a medical device, current coating procedures are designed to result in a uniform application of therapeutic agent across the medical device, which is suitable and often desired for many current medical devices. Such a coating process, however, does not allow for differentiation in drug amount across the medical device. Therefore, there is a need in the art for a coating process that allows for a broader weight distribution on the medical device and that allows for non-uniform application of the therapeutic agent on the medical device. SUMMARY OF THE INVENTION The present invention provides a method of manufacturing a medical device comprising a total desired amount of a first and second therapeutic agent disposed thereon. The method includes applying a first desired amount of a first therapeutic agent to a first portion of a medical device and then determining a first actual amount of the first therapeutic agent, wherein the first actual amount is the amount of the first therapeutic agent actually disposed on the first portion of the medical device. The method further comprises applying a second desired amount of a second therapeutic agent to a second portion of a medical device, wherein the second desired amount is determined by calculating the difference between the total desired amount and the first actual amount. The present invention additionally provides a method of manufacturing a medical device comprising a desired amount of a positive therapeutic agent disposed thereon. The method comprises applying a desired amount of a positive therapeutic agent to the medical device and then determining the actual amount of the positive therapeutic agent. The actual amount is the amount of the positive therapeutic agent that is actually disposed on the medical device. The method then comprises determining if the actual amount of the positive therapeutic agent is greater than the desired amount of the positive therapeutic agent. If the actual amount of the positive therapeutic agent is greater than the desired amount of the positive therapeutic agent, the method further comprises applying to the medical device, a negative agent that has a neutralizing or opposing effect on the positive therapeutic agent. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a medical device according to an embodiment of the present invention. FIG. 2 illustrates a medical device according to an embodiment of the present invention. FIG. 3 illustrates a medical device according to an embodiment of the present invention. FIG. 4 illustrates a medical device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION As referred to herein, the terms “therapeutic agent” or “therapeutic agents” are used interchangeably with the term “drug” or “drugs.” In addition, the use herein of the terms “first therapeutic agent” and “second therapeutic agent,” does not necessarily mean the first and second therapeutic agents are different compositions although the first and second therapeutic agents may be different compositions. Similarly, the use herein of the terms “first coating” and “second coating” does not necessarily mean the first and second coatings are different compositions although the first and second coatings may be different compositions. The present invention provides a multi-step method of manufacturing a medical device containing a first and a second therapeutic agent that results in a lower maximum error in the total amount of the first and the second therapeutic agent actually disposed on the medical device. In one embodiment, a method of manufacturing a medical device having a total desired amount of a first and a second therapeutic agent includes the steps of applying a first desired amount of a first therapeutic agent to a first portion of the medical device wherein the first desired amount refers to the predetermined amount of the first therapeutic agent desired to be applied to first portion of the medical device. The next step of the method of the present invention is determining a first actual amount of the first therapeutic agent. The first actual amount refers to the amount of the first therapeutic agent actually disposed on the medical device, which may be, and often is, different than the first desired amount of the first therapeutic agent applied to the first portion. After the first actual amount is determined, the method includes the step of applying a second desired amount of a second therapeutic agent to a second portion of the medical device, wherein the second desired amount is determined by calculating the difference between the total desired amount and the first actual amount. For example, if the total desired amount of a therapeutic agent desired to be applied to the medical device is 100 milligrams (mg) and the first portion comprises 40% of the surface area of the medical device, then a first desired amount of 40 mg of first therapeutic agent is applied to the first portion. The amount of first therapeutic agent actually disposed on the first portion is then measured by weighing, for example, the medical device. If the first actual amount of the first therapeutic agent disposed on the medical device is 36 mg, for example, then a second desired amount of 64 mg of the second therapeutic agent is applied to the second portion of the medical device. In a preferred embodiment, the first portion has a greater surface area than the second portion. In a more preferred embodiment, the first therapeutic agent is contained in a first coating that is applied to the first portion and the second therapeutic agent is contained in a second coating that is applied to the second portion. The multi-step coating process according to the present invention provides for a lower maximum final error in the amount of the total first and second therapeutic agents disposed on the medical device. For example, with current industry standard processes of coating medical devices, there is approximately a +/−10% variation in the amount of therapeutic agent actually disposed on the medical device. If, for purposes of this example, the first portion comprises 90% of the medical device, then initially coating the first portion according to the present invention results in disposition of 81% to 99% of the total desired amount of the therapeutic agent. The amount of therapeutic agent subsequently applied to the second portion can thus be adjusted to between 1% and 19%, resulting in a maximum final error of disposed therapeutic agent being 2% instead of 10%. Furthermore, because the first and second therapeutic agents are being applied to the medical device in separate steps, the medical device can have differential drug properties along its length. Specifically, first and second therapeutic agents can have differences in their drug release kinetics, such as difference in the amount, rate, and/or duration of drug release, which result in the medical device having differential drug release properties along its length. The specific differences in drug release kinetics can be targeted to the anatomical and/or pathological characteristics of the areas of the target site to which the first and second portions of the medical device (and therefore the first and second therapeutic agents) are respectively to be exposed. Non-limiting examples of such anatomical characteristics include the shape, diameter, number of side branches of the arteries, and location with respect to the ostium of the areas of the target site and the consequential flow behaviors of the areas of the target site. Non-limiting examples of pathological characteristics include the stage or presence of disease of the areas of the target site. For example, if the area of the target site that is exposed to the first portion of the medical device is the “first area” and the area of the target site that is exposed to the second portion of the medical device is the “second area,” the medical device may be placed in a bifurcation or ostium in a blood vessel and the first area may be an area of the blood vessel that experience greater turbulent flow (and therefore the first portion may have a greater exposure to deposited material in the vessel) than the second area of the target site. Similarly, the first area may be an outer arcuate section of a vessel and the second area may be an inner arcuate section of a vessel, such sections experiencing different flow behaviors. Furthermore, the medical device may be placed in a tapered vessel and the first area may have a greater diameter than the second area. Alternatively, the first area may be in a disease state and the second area may be in a non-diseased state. For example, the first area may be the site of a vulnerable plaque in an artery and the second area may be the unaffected side of the artery. Alternatively, the first area and the second area may both be diseased but the first area may be in a more advanced disease state than the second area of the target site. To account for these different anatomical and pathological characteristics of the first and second areas of the target site and therefore the different anatomical and pathological characteristics to which the first and second portions are exposed, the first and second therapeutic agents may have different drug release kinetics. With respect to these specific examples, first therapeutic agent would have an amount, duration and/or rate of release that is greater than that of second therapeutic agent. Of course, the above-mentioned anatomical and pathological characteristics are exemplary and merely illustrate examples of how and why the release kinetics of the first and second therapeutic agents may differ. The first and second portions of the medical device may be targeted to any anatomical and/or pathological conditions of the first and second areas of the target site. Such differences in drug release kinetics of the first and second therapeutic agents can occur because of the different amounts of the first and second therapeutic agents that can be applied to the first and second portions, respectively, of the medical device during the multi-step manufacturing process. Furthermore, the compositions of the first and second therapeutic agents applied during the multi-step manufacturing process can be differed to provide for different drug release kinetics. For example, the first therapeutic agent may be a composition that has a sustained release rate and the second therapeutic agent may be a composition that has an immediate release rate. Alternatively, the compositions may have other different therapeutic properties dependent on the anatomical or pathological characteristics of the first and second areas. For example, in the case where the first area of the target site has a vulnerable plaque and the second area is non-inflamed, the first therapeutic agent may be an anti-inflammatory drug and the second therapeutic may be an endothelial cell stimulating substance. Alternatively, the first and second therapeutic agents may be distributed in a first and a second coating respectively that are applied to the respective first portion and second portion of the medical device. The first and second coatings may have different properties such that the first and second therapeutic agents have different drug release kinetics. For example, the first and second coatings may be different polymer compositions that have different bioabsorption rates thereby providing different release rates of the first and second therapeutic agents. Alternatively, the first and second coatings may be manufactured of the same composition but may be applied to the first and section portions in different amounts such that the first and second coatings have different thickness, which also results in the first and second therapeutic agents having different release rates. Of course it is understood that these mechanisms of providing different drug release kinetics between the first and second therapeutic agents are merely exemplary and other mechanisms will be readily known to one in the art. Further, any described or known mechanism may be used alone or in combination with other mechanisms. The first therapeutic agent and the second therapeutic agent used in the multi-step manufacturing process of the present invention comprise at least one first therapeutic agent and at least one second therapeutic agent. As such, the therapeutic agents should not be interpreted as necessarily being single respective therapeutic agents. The present invention contemplates the first therapeutic agent to include any number or combination of therapeutic agents and similarly contemplates the second therapeutic agent to include any number or combination of therapeutic agents. Furthermore, although the aforementioned method of the present invention involves a two-step process, the application process may include more than two steps involving coating more than two portions of the medical device with more than two therapeutic agents. For example, to manufacture a medical device comprising a first portion, a second portion, and a third portion, therapeutic agents are sequentially applied to each portion with intermediate determinations of the actual amount of drug disposed on the medical device between application steps. Preferably the first, second and third portions have respectively decreasing surface areas. For example, if the total amount of therapeutic agent desired to be applied to the medical device is 100 milligrams (mg) and the first portion comprises 60% of the surface area, the second portion comprises 30% of the surface area, and the third portion comprises 10% of the surface area of the medical device, then a first desired amount of 60 mg of a first therapeutic agent is first applied to first portion. The amount of first therapeutic agent actually disposed on the first portion is then determined. If, for example, it is determined that 54 mg, for example, of the first therapeutic agent is actually disposed on the first portion, then in the next application step, a second desired amount of 36 mg of a second therapeutic agent is applied to the second portion. The amount of the second therapeutic agent actually disposed on the second portion is then measured. If, for example, it is determined that approximately 32 mg of the second therapeutic agent is actually disposed on the second portion, then in the next application step, approximately a third desired amount of 14 mg is applied to the third portion. Of course, the above-mentioned amounts are exemplary and merely illustrate an application of the multi-step application process according to the present invention. In another embodiment, the multi-step coating process according to the present invention is performed before assembly of the medical device. In other words, the first portion and the second portion are initially separate and unconnected and coated with therapeutic agents while being separate and unconnected. After coating, the first and second portions are connected or otherwise attached to each other to form a fully assembled medical device. Specifically, in this embodiment, a first desired amount of a first therapeutic agent is applied to the first portion and a first actual amount of the first therapeutic agent is determined. Then a second desired amount of a second therapeutic agent is applied to the second portion by calculating the difference between the total desired amount and the first actual amount. The first and second portions are then assembled together. With respect to how the first and second therapeutic agents are applied using the multi-step application process of the present invention, in embodiments where the first and second therapeutic agents are contained within first and second coatings respectively, the medical device may be sequentially coated by using a spraying process that involves covering the second portion, with a shield, for example, while coating the first portion and then covering the first portion while covering the second portion. Alternatively, the first and second portions may be coated using an inkjet coating principle by coating the first portion with a first therapeutic agent, which may be in the form of microdroplets and then coating the second portion with a second therapeutic agent, which may also be in the form of microdroplets. Alternatively, a single coating could be applied to the first and second portions of the medical device and then a first plurality of reservoirs and a second plurality of reservoirs could be created in the single coating, such as by a heat, UV, chemical, or laser source. In this embodiment, the part of the coating defining the first plurality of reservoirs coats the first portion and the part of the coating defining the second plurality of reservoirs coats the second portion. The first and second therapeutic agents could then be placed in the first and second plurality of reservoirs, respectively. With respect to the locations in which first and second therapeutic agents are applied to medical device, the first and second therapeutic agents may be applied to any relative locations of the medical device in any pattern or arrangement. For example, referring to FIG. 1, in embodiments where the first therapeutic agent is applied to first portion 20 and second therapeutic agent is applied to second portion 30 and first portion 20 has a greater surface area than second portion 30, a distal section 50 and a medial section 60 of medical device 10 may comprise first portion 20 and a proximal section 70 may comprise second portion 30. Accordingly, distal section 50 and medial section 60 would have a first therapeutic agent applied thereon, the amount of first therapeutic agent actually disposed on distal and medial sections 50 and 60 would be determined and then a second desired amount of a second therapeutic agent would be applied to proximal section 70, wherein the second amount is determined by calculating the difference between the total desired amount of therapeutic agent to be disposed on medical device 10 and the first actual amount of first therapeutic agent. Alternatively, referring to FIG. 2, first portion 20 and second portion 30 may be adjacent to each other with respect to the longitudinal axis of medical device 10. Referring to FIG. 3, in an alternative embodiment, first portion 20 comprises a first layer of coating 100 containing first therapeutic agent, and second portion 30 comprises a second layer of coating 110 containing a second therapeutic agent and located between first layer 100 and the outer surface 120 of medical device 10. Preferably, the locations where first and second therapeutic agents are applied to medical device 10 are targeted to the intended application of medical device 10 and in particular the anatomical or pathological characteristics of the target site to which first and second portions 20 and 30 are exposed. Referring to FIG. 4, in an alternative embodiment, first portion 20 and second portion 30 each comprise a plurality of subsections. It should be emphasized that in the multi-coating process of the present invention, the medical device may comprise any number and/or pattern of portions and such portions may comprise any number and/or combination of therapeutic agents. In another aspect, the present invention provides a multi-step coating process to manufacture a medical device comprising a total desired amount of a positive therapeutic agent. In this aspect, a negative agent that has a neutralizing or opposing effect on the positive therapeutic agent is applied to the medical device if, for example, an excess of the positive therapeutic agent is initially applied to the medical device. Specifically, the method comprises applying a desired amount of a positive therapeutic agent to the medical device and then determining the amount of the positive therapeutic agent actually disposed on the medical device (the actual amount). The method then comprises determining if the actual amount of the positive therapeutic agent is greater than the total desired amount of the positive therapeutic agent. If the actual amount of the positive therapeutic agent is greater than the total desired amount, i.e. an excess of positive therapeutic agent is actually disposed on the medical device, then a negative agent is applied to the medical device. In a more preferred embodiment, positive therapeutic agent and negative agent are each contained in coatings that are applied to the medical device. Negative agent can be any agent(s) that has a neutralizing or opposing effect on positive therapeutic agent. For example, negative therapeutic agent may be a solvent, a therapeutic agent, a source of energy, an agent that is activated by a source of energy, or electroactive polymers. In the case of negative agent being a therapeutic agent, combinations of positive therapeutic agent and negative agent include, for example, heparin and anti-heparin, and proteins and complementary neutralizing proteins. In the case of negative agent being a source of energy, negative agent could be ultraviolet light or heat that could be applied to medical device after application of positive therapeutic agent to de-activate positive therapeutic agent. In the case of negative agent being an agent that is activated by a source of energy, the desired amount of positive therapeutic agent could be encapsulated in microcapsules that are placed in a coating that is applied to the medical device. The microcapsules could also contain a negative agent such as paramagnetic particles that are activated upon application of an external magnetic field and that cause elimination of the coating upon activation. In such a circumstance, a magnetic field is exposed to areas of the medical device after the coating containing the microcapsules is applied to the medical device. Exposure to the magnetic energy activates the paramagnetic particles and causes degradation of the areas of the coating that are exposed to the magnetic energy thereby eliminating the positive therapeutic agent in those respective areas. Alternatively, the negative agent could be a conducting electro-active polymer (CEP), such as polypyrroles, polythiophenes, and polyanilines (I-III), which typically exhibit high electrical conductivity in the raneg 1-103 S cm−1. Such CEPs can be rapidly and reversibly switched between different oxidation states and can be synthesized by oxidative polymerization of the appropriate monomer. The oxidation can be achieved either chemically (e.g. using FeCl3 or S2O8 2− as an oxidant) or electrochemically in a conventional cell with the dopant anion (A−) being incorporated into the growing polymer chains. As with other aspects of the present invention, the positive therapeutic agent and the negative agent comprise at least one positive therapeutic agent and at least one negative agent. With respect to specific details of the present invention, therapeutic agents according to the present invention may be any pharmaceutically acceptable agents such as a non-genetic therapeutic agents, biomolecules, small molecules, or cells. Exemplary non-genetic therapeutic agents include anti-thrombogenic agents such heparin, heparin derivatives, prostaglandin (including micellar prostaglandin E1), urokinase, and PPack (dextrophenylalanine proline arginine chloromethylketone); anti-proliferative agents such as enoxaprin, angiopeptin, sirolimus (rapamycin), tacrolimus, everolimus, monoclonal antibodies capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid; anti-inflammatory agents such as dexamethasone, rosiglitazone, prednisolone, corticosterone, budesonide, estrogen, estrodiol, sulfasalazine, acetylsalicylic acid, mycophenolic acid, and mesalamine; anti-neoplastic/anti-proliferative/anti-mitotic agents such as paclitaxel, cladribine, 5-fluorouracil, methotrexate, doxorubicin, daunorubicin, cyclosporine, cisplatin, vinblastine, vincristine, epothilones, endostatin, trapidil, and angiostatin; anti-cancer agents such as antisense inhibitors of c-myc oncogene; anti-microbial agents such as triclosan, cephalosporins, aminoglycosides, nitrofurantoin, silver ions, compounds, or salts; biofilm synthesis inhibitors such as non-steroidal anti-inflammatory agents and chelating agents such as ethylenediaminetetraacetic acid, O,O′-bis(2-aminoethyl)ethyleneglycol-N,N,N′,N′-tetraacetic acid and mixtures thereof; antibiotics such as gentamycin, rifampin, minocyclin, and ciprofolxacin; antibodies including chimeric antibodies and antibody fragments; anesthetic agents such as lidocaine, bupivacaine, and ropivacaine; nitric oxide; nitric oxide (NO) donors such as lisidomine, molsidomine, L-arginine, NO-carbohydrate adducts, polymeric or oligomeric NO adducts; anti-coagulants such as D-Phe-Pro-Arg chloromethyl ketone, an RGD peptide-containing compound, heparin, antithrombin compounds, platelet receptor antagonists, anti-thrombin antibodies, anti-platelet receptor antibodies, enoxaparin, hirudin, Warafin sodium, Dicumarol, aspirin, prostaglandin inhibitors, platelet inhibitors and tick antiplatelet factors; vascular cell growth promotors such as growth factors, transcriptional activators, and translational promotors; vascular cell growth inhibitors such as growth factor inhibitors, growth factor receptor antagonists, transcriptional repressors, translational repressors, replication inhibitors, inhibitory antibodies, antibodies directed against growth factors, bifunctional molecules consisting of a growth factor and a cytotoxin, bifunctional molecules consisting of an antibody and a cytotoxin; cholesterol-lowering agents; vasodilating agents; agents which interfere with endogeneus vascoactive mechanisms; and any combinations and prodrugs of the above. Exemplary biomolecules include peptides, polypeptides and proteins; oligonucleotides; nucleic acids such as double or single stranded DNA (including naked and cDNA), RNA, antisense nucleic acids such as antisense DNA and RNA, small interfering RNA (siRNA), and ribozymes; genes; carbohydrates; angiogenic factors including growth factors; cell cycle inhibitors; and anti-restenosis agents. Nucleic acids may be incorporated into delivery systems such as, for example, vectors (including viral vectors), plasmids or liposomes. Non-limiting examples of proteins include monocyte chemoattractant proteins (“MCP-1) and bone morphogenic proteins (“BMP's”), such as, for example, BMP-2, BMP-3, BMP-4, BMP-5, BMP-6 (Vgr-1), BMP-7 (OP-1), BMP-8, BMP-9, BMP-10, BMP-11, BMP-12, BMP-13, BMP-14, BMP-15. Preferred BMPS are any of BMP-2, BMP-3, BMP-4, BMP-5, BMP-6, and BMP-7. These BMPs can be provided as homdimers, heterodimers, or combinations thereof, alone or together with other molecules. Alternatively, or in addition, molecules capable of inducing an upstream or downstream effect of a BMP can be provided. Such molecules include any of the “hedghog” proteins, or the DNA's encoding them. Non-limiting examples of genes include survival genes that protect against cell death, such as anti-apoptotic Bcl-2 family factors and Akt kinase and combinations thereof. Non-limiting examples of angiogenic factors include acidic and basic fibroblast growth factors, vascular endothelial growth factor, epidermal growth factor, transforming growth factor α and β, platelet-derived endothelial growth factor, platelet-derived growth factor, tumor necrosis factor α, hepatocyte growth factor, and insulin like growth factor. A non-limiting example of a cell cycle inhibitor is a cathespin D (CD) inhibitor. Non-limiting examples of anti-restenosis agents include p15, p16, p18, p19, p21, p27, p53, p57, Rb, nFkB and E2F decoys, thymidine kinase (“TK”) and combinations thereof and other agents useful for interfering with cell proliferation. Exemplary small molecules include hormones, nucleotides, amino acids, sugars, and lipids and compounds have a molecular weight of less than 100 kD. Exemplary cells include stem cells, progenitor cells, endothelial cells, adult cardiomyocytes, and smooth muscle cells. Cells can be of human origin (autologous or allogenic) or from an animal source (xenogenic), or genetically engineered. Any of the therapeutic agents may be combined to the extent such combination is biologically compatible. As mentioned above, the therapeutic agents may be incorporated into coatings and such coatings may comprise polymers that are biodegradable or non-biodegradable. Non-limiting examples of suitable non-biodegradable polymers include polyvinylpyrrolidone including cross-linked polyvinylpyrrolidone; polyvinyl alcohols, copolymers of vinyl monomers such as EVA; polyvinyl ethers; polyvinyl aromatics; polyethylene oxides; polyesters including polyethylene terephthalate; polyamides; polyacrylamides; polyethers including polyether sulfone; polyalkylenes including polypropylene, polyethylene and high molecular weight polyethylene; polyurethanes; polycarbonates, silicones; siloxane polymers; cellulosic polymers such as cellulose acetate; polymer dispersions such as polyurethane dispersions (BAYHDROL®); squalene emulsions; and mixtures and copolymers of any of the foregoing. Non-limiting examples of suitable biodegradable polymers include polycarboxylic acid, polyanhydrides including maleic anhydride polymers; polyorthoesters; poly-amino acids; polyethylene oxide; polyphosphazenes; polylactic acid, polyglycolic acid and copolymers and mixtures thereof such as poly(L-lactic acid) (PLLA), poly(D,L,-lactide), poly(lactic acid-co-glycolic acid), 50/50 (DL-lactide-co-glycolide); polydioxanone; polypropylene fumarate; polydepsipeptides; polycaprolactone and co-polymers and mixtures thereof such as poly(D,L-lactide-co-caprolactone) and polycaprolactone co-butylacrylate; polyhydroxybutyrate valerate and blends; polycarbonates such as tyrosine-derived polycarbonates and arylates, polyiminocarbonates, and polydimethyltrimethylcarbonates; cyanoacrylate; calcium phosphates; polyglycosaminoglycans; macromolecules such as polysaccharides (including hyaluronic acid; cellulose, and hydroxypropylmethyl cellulose; gelatin; starches; dextrans; alginates and derivatives thereof), proteins and polypeptides; and mixtures and copolymers of any of the foregoing. The biodegradable polymer may also be a surface erodable polymer such as polyhydroxybutyrate and its copolymers, polycaprolactone, polyanhydrides (both crystalline and amorphous), maleic anhydride copolymers, and zinc-calcium phosphate. In a preferred embodiment, the polymer is polyacrylic acid available as HYDROPLUS® (Boston Scientific Corporation, Natick, Mass.), and described in U.S. Pat. No. 5,091,205, the disclosure of which is incorporated by reference herein. In a more preferred embodiment, the polymer is a co-polymer of polylactic acid and polycaprolactone. Such coatings used with the present invention may be formed by any method known to one in the art. For example, an initial polymer/solvent mixture can be formed and then the therapeutic agent added to the polymer/solvent mixture. Alternatively, the polymer, solvent, and therapeutic agent can be added simultaneously to form the mixture. The polymer/solvent mixture may be a dispersion, suspension or a solution. The therapeutic agent may also be mixed with the polymer in the absence of a solvent. The therapeutic agent may be dissolved in the polymer/solvent mixture or in the polymer to be in a true solution with the mixture or polymer, dispersed into fine or micronized particles in the mixture or polymer, suspended in the mixture or polymer based on its solubility profile, or combined with micelle-forming compounds such as surfactants or adsorbed onto small carrier particles to create a suspension in the mixture or polymer. The coatings may comprise multiple polymers and/or multiple therapeutic agents. The coatings can be applied to the medical device by any known method in the art including dipping, spraying, rolling, brushing, electrostatic plating or spinning, vapor deposition, air spraying including atomized spray coating, and spray coating using an ultrasonic nozzle. It is also within the scope of the present invention to apply multiple layers of polymer coatings onto the medical device. Such multiple layers may contain the same or different therapeutic agents and/or the same or different polymers. Methods of choosing the type, thickness and other properties of the polymer and/or therapeutic agent to create different release kinetics are well known to one in the art. The medical device may also contain a radio-opacifying agent within its structure to facilitate viewing the medical device during insertion and at any point while the device is implanted. Non-limiting examples of radio-opacifying agents are bismuth subcarbonate, bismuth oxychloride, bismuth trioxide, barium sulfate, tungsten, and mixtures thereof. Non-limiting examples of medical devices according to the present invention include catheters, guide wires, balloons, filters (e.g., vena cava filters), stents, stent grafts, vascular grafts, intraluminal paving systems, implants and other devices used in connection with drug-loaded polymer coatings. Such medical devices may be implanted or otherwise utilized in body lumina and organs such as the coronary vasculature, esophagus, trachea, colon, biliary tract, urinary tract, prostate, brain, and the like. The medical devices of the present invention can be used, for example, in any application for treating, preventing, or otherwise affecting the course of a disease or tissue or organ dysfunction. For example, the methods and devices of the present invention can be used to induce or inhibit angiogenesis, as desired, to present or treat restenosis, to treat a cardiomyopathy or other dysfunction of the heart, for treating Parkinson's disease or a stroke or other dysfunction of the brain, for treating cystic fibrosis or other dysfunction of the lung, for treating or inhibiting malignant cell proliferation, for treating any malignancy, and for inducing nerve, blood vessel or tissue regeneration in a particular tissue or organ. The foregoing description has been set forth merely to illustrate the invention is not intended as being limiting. Each of the disclosed embodiments may be considered individually or in combination with other embodiments of the invention, other variations, and other aspects of the invention. Modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art. Therefore, the present invention should be construed to include everything within the scope of the appended claims and equivalents thereof. | <SOH> BACKGROUND OF THE INVENTION <EOH>Minimally invasive medical devices such as stents, grafts, and balloon catheters, are used for a number of medical purposes including the treatment of vascular disease, reinforcement of recently re-enlarged lumens, and the replacement of ruptured vessels. It is often beneficial to incorporate in such medical devices, therapeutic agents, which are often contained within a coating applied to the surface of the medical device, to provide desired therapeutic properties and effects. For example, it is useful to apply a coating containing therapeutic agents to medical devices to provide for the localized delivery of therapeutic agents to target locations within the body, such as an occluded body lumen. Compared to systemic drug administration, such localized drug delivery minimizes unwanted effects on parts of the body which are not to be treated and allows for the delivery of higher amounts of therapeutic agent to the afflicted part of the body. Coatings containing therapeutic agents may also provide for controlled release, which includes long-term or sustained release, of the therapeutic agent. Conventionally, coatings have been applied to medical devices by processes such as dipping, spraying, vapor deposition, plasma polymerization, and electro-deposition. Although these processes have been used to produce satisfactory coatings, there are numerous drawbacks associated with these processes. For example, with current spraying processes, it is difficult to achieve a narrow weight distribution of the therapeutic agent on the medical device. Furthermore, the evaporation of solvents used in the coatings, the complex geometries of many medical devices, and the low amounts of therapeutic agents applied to the coatings contribute to the difficulty in measuring the amount of therapeutic agent actually disposed on the medical device. In addition, there is no direct feedback loop associated with these medical devices to ascertain the actual amount of therapeutic agent disposed on the medical device and therefore it is often necessary to maintain processing parameters as constant as possible. However, due to the large number of processing parameters associated with coating a medical device, there is still a significant amount of variation in the amount of drug disposed on the medical device. In addition to the difficulties associated with achieving a narrow weight distribution of a therapeutic agent on a medical device, current coating procedures are designed to result in a uniform application of therapeutic agent across the medical device, which is suitable and often desired for many current medical devices. Such a coating process, however, does not allow for differentiation in drug amount across the medical device. Therefore, there is a need in the art for a coating process that allows for a broader weight distribution on the medical device and that allows for non-uniform application of the therapeutic agent on the medical device. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a method of manufacturing a medical device comprising a total desired amount of a first and second therapeutic agent disposed thereon. The method includes applying a first desired amount of a first therapeutic agent to a first portion of a medical device and then determining a first actual amount of the first therapeutic agent, wherein the first actual amount is the amount of the first therapeutic agent actually disposed on the first portion of the medical device. The method further comprises applying a second desired amount of a second therapeutic agent to a second portion of a medical device, wherein the second desired amount is determined by calculating the difference between the total desired amount and the first actual amount. The present invention additionally provides a method of manufacturing a medical device comprising a desired amount of a positive therapeutic agent disposed thereon. The method comprises applying a desired amount of a positive therapeutic agent to the medical device and then determining the actual amount of the positive therapeutic agent. The actual amount is the amount of the positive therapeutic agent that is actually disposed on the medical device. The method then comprises determining if the actual amount of the positive therapeutic agent is greater than the desired amount of the positive therapeutic agent. If the actual amount of the positive therapeutic agent is greater than the desired amount of the positive therapeutic agent, the method further comprises applying to the medical device, a negative agent that has a neutralizing or opposing effect on the positive therapeutic agent. | 20040128 | 20080805 | 20050728 | 57927.0 | 0 | CAMERON, ERMA C | MULTI-STEP METHOD OF MANUFACTURING A MEDICAL DEVICE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,765,083 | ACCEPTED | Offset printing press unit with removable cylinders | An offset printing press having plate and blanket cylinder retention mechanisms, each retention mechanism having at least one trunnion axially displaceable between an operative position and a disengaged position. Said trunnion is freely disconnected from an associated cylinder end in the disengaged position such that the plate cylinder and the blanket cylinder are removable from the printing press from between the frame structure. One of the cylinder retention mechanisms is selectively displaceable relative to the frame structure such that a distance between the cylinder axes of rotation is variable. The plate and blanket cylinders are thus removable from the printing press and substitutable with replacement cylinders having a different outer circumference. The press comprises a gear drive system which remains in gear meshed engagement with both the plate cylinder and the blanket cylinder regardless of the variable relative positions thereof. | 1. An offset printing press comprising: a plate cylinder, a blanket cylinder and an impression cylinder each mounted in a frame structure for rotation about parallel individual axes of rotation, the plate cylinder and the blanket cylinder having a common outer circumference defining a print repeat size produced by the plate and blanket cylinders; plate and blanket cylinder retention mechanisms respectively engaging the plate cylinder and the blanket cylinder, each retention mechanism comprising first and second trunnions rotatable within the frame structure and respectively engageable to a corresponding cylinder end, at least one of said first and second trunnions being axially displaceable by an actuating member between an operative position and a disengaged position, said at least one trunnion being fastenable in mating engagement with said corresponding cylinder end in the operative position and freely disconnected from said corresponding cylinder end in the disengaged position, such that the plate cylinder and the blanket cylinder are removable from the printing press from between the frame structure; and wherein at least one of the plate and blanket cylinder retention mechanisms is selectively displaceable relative to the frame structure such that a distance between the axes of rotation is variable, said at least one cylinder retention mechanism being fastenable in a desired position to maintain the distance at a predetermined value; whereby the plate and blanket cylinders are removable from the printing press and substitutable with replacement cylinders having a different outer circumference, thereby providing a correspondingly different sized print repeat when the replacement cylinders are installed into the printing press. 2. The printing press as defined in claim 1, wherein each of the plate and blanket cylinders comprises a central mandrel shaft on which an outer sleeve is removably fixed, the outer sleeves being removable from the central mandrel shafts when the cylinders are removed from the printing press such that substitution of the outer sleeves by replacement sleeves is possible. 3. The printing press as defined in claim 1, wherein the plate cylinder is eccentrically mounted, permitting disengagement of the plate cylinder from contacting engagement with the blanket cylinder to temporarily interrupt printing. 4. The printing press as defined in claim 1, wherein the trunnions are rotatable in the frame structure within bearings, the bearings remaining in contacting engagement with the frame structure when the trunnions are disposed in either one of the operative position and the disengaged position. 5. The printing press as defined in claim 1, wherein the cylinder retention mechanism of the blanket cylinder comprises translating bearing blocks selectively displaceable within corresponding slots in the frame structure such that the blanket cylinder is located in the desired position relative to the substantially fixed plate cylinder. 6. The printing press as defined in claim 1, further comprising a lateral adjustment mechanism providing axial displacement of the plate cylinder relative to the blanket cylinder, thereby permitting fine axial relative adjustment of the plate cylinder and the blanket cylinder to precisely control a contact stripe therebetween. 7. The printing press as defined in claim 6, wherein an independent motor is provided for driving the lateral adjustment mechanism. 8. The printing press as defined in claim 1, wherein the trunnions for each of the plate and blanket cylinders are independently operable, such that each of the plate cylinder and blanket cylinder is independently removable when the corresponding trunnions are displaced to the disengaged position. 9. The printing press as defined in claim 1, wherein the actuating member is pneumatically operated. 10. The printing press as defined in claim 1, further comprising a drive system having a drive motor operatively connected to one of the plate cylinder and the blanket cylinder to provide driven rotation thereto and a gear drive linkage mechanism operably inter-engaging the plate cylinder and the blanket cylinder for mutual rotation thereof, the gear drive linkage mechanism remaining in gear meshed engagement with both the plate cylinder and the blanket cylinder regardless of their variable relative positions. 11. The printing press as defined in claim 10, wherein the drive motor directly drives the plate cylinder. 12. The printing press as defined in claim 11, wherein angular speed of the drive motor is variable, such that the replacement cylinders having the different outer circumference are employable without having to replace gear elements of the drive system. 13. The printing press as defined in claim 1, wherein the plate and blanket cylinder retention mechanisms are independently operable. 14. A cylinder drive system for an offset printing press having a plate cylinder and a blanket cylinder mounted in a frame structure such that a distance between axes of rotation thereof is selectively variable, the cylinder drive system comprising: a drive motor operatively connected to one of the plate cylinder and the blanket cylinder to provide driven rotation thereto; a gear drive linkage mechanism operably inter-engaging the plate cylinder and the blanket cylinder such that the drive motor drives both the plate and blanket cylinders; and wherein the gear drive linkage mechanism remains in gear meshed engagement with both the plate cylinder and the blanket cylinder regardless of the variable relative positions thereof. 15. The cylinder drive system as defined in claim 14, wherein the drive motor drives the plate cylinder. 16. The cylinder drive system as defined in claim 14, wherein the gear drive linkage mechanism comprises a plate cylinder gear, a blanket cylinder gear, a first linkage arm having a first idler gear rotatably mounted thereto, and a second linkage arm pivotably engaged with the first linkage arm and having a second idler gear rotatably mounted thereto, the first and second idler gears remaining intermeshed with each other and the plate cylinder and blanket cylinder respectively, regardless of the relative positions of the plate and blanket cylinders. 17. The cylinder drive system as defined in claim 16, wherein the first linkage arm is pivotable about a plate cylinder rotation axis and the second linkage arm is pivotable about a blanket cylinder rotation axis, the first and second linkage arms being relatively pivotable about a pivot axis coaxial with a rotation axis of one of the first and second idler gears. 18. The cylinder drive system as defined in claim 14, wherein the gear drive linkage mechanism comprises a lateral retaining mechanism which prevents excessive lateral movement thereof. | TECHNICAL FIELD The present invention relates generally to offset printing presses, and more particularly to an offset printing press unit having removable plate and blanket cylinders. BACKGROUND OF THE INVENTION Offset printing presses are well known in the art. Typically, water and ink are supplied to a printing plate cylinder, and are then transferred to a blanket cylinder for printing onto sheets or web, fed between the blanket cylinder and an impression cylinder. The water supply to the plate cylinder usually comprises a dampening unit having a dampening form roller which contacts the plate cylinder and is fed water from a water pan through intermediate water transferring rollers. Similarly, an inking unit transfers ink from an ink supply to the plate cylinder through an ink transfer and application rollers. While such presses have fixed lateral dimensions, and as such printed products wider than the length of the cylinders cannot be produced, the circumference of the rotating cylinders determines the length of each repeated pattern being printed onto the web or sheets passing therethrough. Accordingly, the larger the circumference of the plate and blanket cylinders being used, the longer the printed pattern that can be produced. Therefore, in order to permit a press to be modified to permit printing of difference sized “repeats”, or each repeated pattern that is printed onto the web for each revolution of the cylinders, it is desirable to be able to use plate and blanket cylinders of different circumferences in order to be able to vary the repeat size provided by the press. To achieve this desired press convertibility, it has been know to provide an offset press with a removable cylinder cartridge, having at least the plate and blanket cylinders mounted therein. For such a cartridge to be removed from the rest of the printing press, the cylinders must be disengaged from one another, and the entire cartridge is slid out as a single unit from the frame of the press. A replacement cartridge having therein plate and blanket cylinders of a smaller or larger circumference, is then inserted into the press in place of the original cartridge. This therefore permits the press to be converted to change the size of the repeat produced with each rotation of the press cylinders. While this solution provides the press with repeat size flexibility, each cartridge is large and costly, and therefore the practical range of flexibility is generally limited by the cost and space considerations of keeping many different cartridges having cylinders of various sizes. Various printing presses having removable cylinders are also known. However, to permit the removal of the cylinders requires them to be disengageable from one another. The precisely set contact stripe between the cylinders is therefore often lost. Further, this typically also requires that the intermeshed gears driving the cylinders can be completely disengaged from each other every time a cylinder is to be removed, and easily re-engaged once a new replacement cylinder is introduced into the press. A known way to avoid this problem is to completely replace the gear train by drive motors used to drive the cylinders at the necessary speeds. Particularly, some presses employ a drive motor for each cylinder, thereby circumventing the requirement of gear trains completely. However, printing presses which are completely driven by servo drive systems are more expensive and more complex than those which use traditional gear train drives. Further, if any of the drive motors are incorrectly set or malfunction, the resultant mismatch in cylinder speeds can cause defective printed product or damage to the press. SUMMARY OF THE INVENTION It is an object of the present invention to provide an offset printing press with independently removable plate and blanket cylinders. It is also an object of the present invention to provide an offset printing press having plate and blanket cylinders with replaceable outer sleeves. It is an object of the present invention to provide an offset printing press having a cylinder drive linkage mechanism which maintains gear mesh when cylinders are disengaged from one another. It is another object of the present invention to provide a variable form roller throw-off and strip adjustment mechanism for an offset printing press. Therefore in accordance with the present invention, there is provided an offset printing press comprising: a plate cylinder, a blanket cylinder and an impression cylinder each mounted in a frame structure for rotation about parallel individual axes of rotation, the plate cylinder and the blanket cylinder having a common outer circumference defining a print repeat size produced by the plate and blanket cylinders; plate and blanket cylinder retention mechanisms respectively engaging the plate cylinder and the blanket cylinder, each retention mechanism comprising first and second trunnions rotatable within the frame structure and respectively engageable to a corresponding cylinder end, at least one of said first and second trunnions being axially displaceable by an actuating member between an operative position and a disengaged position, said at least one trunnion being fastenable in mating engagement with said corresponding cylinder end in the operative position and freely disconnected from said corresponding cylinder end in the disengaged position, such that the plate cylinder and the blanket cylinder are removable from the printing press from between the frame structure; and wherein at least one of the plate and blanket cylinder retention mechanisms is selectively displaceable relative to the frame structure such that a distance between the axes of rotation is variable, said at least one cylinder retention mechanism being fastenable in a desired position to maintain the distance at a predetermined value; whereby the plate and blanket cylinders are removable from the printing press and substitutable with replacement cylinders having a different outer circumference, thereby providing a correspondingly different sized print repeat when the replacement cylinders are installed into the printing press. There is also provided, in accordance with the present invention, a cylinder drive system for an offset printing press having a plate cylinder and a blanket cylinder mounted in a frame structure such that a distance between axes of rotation thereof is selectively variable, the cylinder drive system comprising: a drive motor operatively connected to one of the plate cylinder and the blanket cylinder to provide driven rotation thereto; a gear drive linkage mechanism operably inter-engaging the plate cylinder and the blanket cylinder such that the drive motor drives both the plate and blanket cylinders; and wherein the gear drive linkage mechanism remains in gear meshed engagement with both the plate cylinder and the blanket cylinder regardless of the variable relative positions thereof. There may also be provided, in accordance with the present invention, an offset printing press including a plate cylinder, a blanket cylinder and an impression cylinder mounted in a frame structure in serial contactable engagement, the printing press comprising a cylinder adjustment mechanism operable to displace at least one of the plate cylinder and the impression cylinder between a predetermined printing position, wherein said at least one of the plate cylinder and the impression cylinder is in contacting engagement with the blanket cylinder, and a disengaged position, wherein said at least one of the plate cylinder and the impression cylinder is removed from contacting engagement with the blanket cylinder, the cylinder adjustment mechanism being selectively actuable and providing controlled variable displacement of said at least one of the plate cylinder and the impression cylinder relative to the blanket cylinder. BRIEF DESCRIPTION OF THE DRAWINGS Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which: FIG. 1 shows a schematic side elevation view of an offset printing press according to the present invention; FIG. 2 is a schematic perspective view of a drive linkage mechanism according to the present invention, for use on the printing press of FIG. 1; FIG. 3a is a schematic side elevation view of the drive linkage mechanism of FIG. 2, showing the plate and blanket cylinders of the present printing press in a first position; FIG. 3b is a schematic side elevation view of the drive linkage mechanism of FIG. 2, showing the plate and blanket cylinders in a second position; FIG. 4 is a schematic front elevation view of the plate and blanket cylinders and the drive linkage mechanism of FIG. 2; FIG. 5a is a schematic side elevation of the offset printing press of FIG. 1, having plate and blanket cylinders of a first diameter; and FIG. 5b is a schematic side elevation of the offset printing press of FIG. 1, having plate and blanket cylinders of a second, larger diameter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 and FIGS. 5a and 5b, the offset printing press 10 generally comprises a cartridge or unit 15, which can be selectively removed from the main portion of the printing press 10. The printing unit 15 comprises a plate cylinder 12, blanket cylinder 14 and an impression cylinder 16 all supported within a common frame structure 18. Water and ink are supplied to the plate cylinder 12 by the dampening unit 22 and the inking unit 20 respectively. The inking unit 20 generally comprises ink transmission rollers 26 and ink application rollers 28. The inking unit 20 receives ink from an ink supply and transmits it to the plate cylinder 12. The multi roller dampening unit 22 generally comprises a dampening form roller 30 in direct contacting engagement with the plate cylinder 12 and with dampening fluid transfer rollers 32, which transfer the dampening fluid from the dampening supply 34 to the dampening form roller 30. The plate cylinder 12 generally comprises a circumferentially disposed printing plate on the outer surface thereof, the circumference of the plate cylinder corresponding to the length of the print repeat produced by the printing plate. The water and ink fed to the plate cylinder 12 are transferred from the exterior surface thereof to the blanket cylinder 14, which is in contacting engagement with the plate cylinder 12. Either sheets or a continuous web are fed between the blanket cylinder 14 and an impression cylinder 16, which is similarly in contacting engagement with the blanket cylinder 14. All cylinder rollers are rotatable and in precise contacting engagement with each adjacent roller along a contact stripe, such that fluid is transferred from one roller to the next. The term contact stripe is used herein to define the line of contact between two cylindrical rollers in contacting engagement. This contact stripe is precisely set, to ensure exact and uniform contact pressure the entire length of the rollers. As mentioned above, the circumference of the rotating cylinders determines the length of each repeated pattern being printed onto the web passing therethrough. The term repeat is generally used herein to define this repeated pattern that is printed on the web for every revolution of the plate and blanket cylinders. In order to allow for a wide range of print repeat sizes at a relatively low cost, the offset printing press 10 of the present invention permits the plate and blanket cylinders 12 and 14 respectively to be independently removed from the printing unit 15 such that they can be replaced with corresponding cylinders having a different circumference. This accordingly permits the size of the repeat to be easily changed. Rather than having to store a large number of pairs of plate and blanket cylinders 12,14 having different circumferences, the interchangeable plate and blanket cylinders 12,14 of the present invention preferably have common central mandrel shafts to which outer sleeves of various circumferences can be selectively engaged. Particularly, referring to FIG. 1, the plate cylinder 12 comprises a central mandrel shaft 52, which has a central axis 46, and an outer plate sleeve 54 mounted thereto. The outer plate sleeve 54, as with all interchangeable sleeves disclosed herein, is mounted to the central mandrel such that the sleeve is removably engaged thereto and is rotatable therewith. The sleeve may be press fit onto the mandrel, or otherwise fixed in place thereon. To remove such a press fit sleeve, air pressure is preferably used to create an air layer between the sleeve and the mandrel shaft, thereby permitting the sleeve to freely slide off the mandrel shaft. The central mandrel shaft 52 of the plate cylinder 12 is held in the press by a plate cylinder retention mechanism, which comprises at least one axially displaceable plate cylinder trunnion 47a (seen in FIGS. 2 and 4). An axially fixed plate cylinder trunnion 47b supports the opposite end of the cylinder, and is rotatable within the press frame. The plate cylinder trunnions 47a,b engage the mandrel shaft 52 in a predetermined center position and are free to rotate in their frame mountings. The trunnions 47a,b are positioned in place in the frame structure 18 by bearings within which they are free to rotate. The trunnions 47a,b engage the ends of the mandrel shaft 52 such that substantially no relative rotation therebetween occurs when they are in mated engagement. Axial outward displacement of at least the trunnions 47a permits the removal of the plate cylinder 12 from the press, and will be described in further detail below. While preferably only the one plate cylinder trunnion 47a is axially displaceable, it is understood that both plate cylinder trunnions 47a and 47b may be axially displaceable. The blanket cylinder 14 comprises a central mandrel shaft 58 having a central axis 48. In the embodiment of FIG. 1, an outer sleeve 60, having the same first outer circumference as the plate sleeve 54, is similarly mounted to the central mandrel shaft 58 of the blanket cylinder 14. The blanket cylinder's displacement line 43 depicts the possible locations for the blanket cylinder central axis 48 within the frame. The blanket cylinder 14 is also preferably removably engaged within the press by a blanket cylinder retention mechanism, which comprises at least one axially displaceable blanket cylinder trunnion 49a (seen in FIGS. 2 and 4) that engages and supports one end of the central mandrel shaft 58 of the blanket cylinder 14. An axially fixed blanket cylinder trunnion 49b supports the opposite end of the cylinder, and is rotatable within the press frame. The blanket cylinder trunnions 49a and 49b extend through the frame structure 18 of the printing unit 15, being supported and located therein by translating bearing-blocks 63 (as seen FIGS. 5a and 5b) which can slide within corresponding guide slots 84 defined in the frame structure 18, such that the central axis 48 of the blanket cylinder 14 can be located anywhere along the blanket cylinder central axis displacement line 43. The translating bearing-blocks 63 can be fixed in any desired position within the guide slots 84. While preferably only the one blanket cylinder trunnion 49a is axially displaceable, it is understood that both blanket cylinder trunnions 49a and 49b may be axially displaceable. Actuating members are preferably used to displace at least the trunnions 47a and 49a between inner the operative position, wherein the trunnions are forced into mating engagement with the ends of each cylinder such that the trunnions and the cylinders rotate together, and the disengaged position, where the trunnions are freely disconnected from the ends of the cylinders such that removal of the cylinders is possible. The actuating members can be any suitable mechanism for axially displacing the trunnions inward and outward relative to the cylinders, such as for example a pneumatically operated cylinder. Preferably, the actuating members are remotely operated, such that the trunnions can be engaged and disengaged from the cylinders by a press operator from a control station. However, a manual override for such a pneumatically operated actuating member can also provided. Thus, both the plate cylinder 12 and blanket cylinder 14 can be independently removed from the press. Once removed, the outer sleeves 54 and 60 can be disengaged from the central mandrel shafts 52 and 58 of the plate cylinder 12 and the blanket cylinder 14 respectively. This therefore permits the outer sleeves to be replaced by alternately sized sleeves, such that the overall outer circumference of the cylinders can be varied. Preferably, only the outer sleeves on the common central mandrel shafts need be replaced in order to change the size of the repeat produced. However, it is also possible to use solid or one-piece cylinders without sleeves, in which case the entire cylinder is replaced. Although, this may be more expensive and necessitate greater storage requirements, one-piece cylinders are nonetheless useful for certain printing applications. The bearing mounting assembly 53 of the plate cylinder 12 are preferably not translatable within the frame structure 18, regardless of the size of the plate cylinder 12, however the mounting assemblies 53 are rotatable therewithin. Referring to FIG. 2, each end of the plate cylinder 12 (more particularly each trunnions 47a) is preferably eccentrically engaged within the rotatable mounting assembly 53, which can be selectively rotated within the frame 18 by a suitable mechanism such that the plate cylinder is disconnected from contacting engagement with the blanket cylinder 14. This “throw-off” permits the printing to be interrupted, and subsequently resumed, without having to precisely re-adjust the contact stripe between the two cylinders. When printing is thus interrupted, the impression cylinder 16 can also be “thrown-off” (ie: disconnected from contacting engagement with the blanket cylinder 14) with a suitable mechanism. The inking unit 20 and dampening unit 22 are displaceable as required to accommodate the particular size of plate cylinder employed, while remaining in contact therewith. Although the plate cylinder 12 is eccentrically mounted, and therefore can be slightly displaced such that it is disengaged from contact with the blanket cylinder 14, the central axis 46 of the plate cylinder 12 otherwise remains secured in place within the frame structure 18. This, therefore, requires that the blanket cylinder 14 is selectively displaceable using the translatable bearing-blocks 63 as described above, such that cylinders of various diameters can be accommodated and a desired contact stripe is maintained between the adjacent cylinders, irrespective of the size of the cylinder (or the outer sleeve thereof) being used. As shown in FIGS. 5a and 5b, the relative positions of different sized printing cylinders can be seen. In FIG. 5a, a plate cylinder 12a and blanket cylinder 14a having a first (smallest) diameter are shown. The bearing-blocks 63 of the blanket cylinder are therefore located at the uppermost position within the guide slots 84. In FIG. 5b, replacement plate cylinder 12b and blanket cylinder 14b having a larger diameter have been installed in the press unit in place of the original plate and blanket cylinders 12a, 14a. The central axis 46 of the plate cylinder is evidently disposed in the same position, while the central axis 48 of the blanket cylinder has been displaced away therefrom, due to the translation of the blanket cylinder bearing-blocks 63 which have been displaced within the guide slots 84 such that the larger diameter plate and blanket cylinders 12b,14b are repositioned having a predetermined contact stripe therebetween. As seen in FIGS. 5a and 5b, the fixed-size impression cylinder 16 is preferably not interchanged regardless of the size of plate and blanket cylinders installed, and remains pivotably engaged within the press. Particularly, the impression cylinder 16 is adjustable on pivoting arms 40 such that the impression cylinder 16 can be correctly positioned with respect to the blanket cylinder 14, irrespective of the size of outer sleeve being employed on the central mandrel shaft 58 thereof. The contact stripe can therefore be maintained therebetween, throughout the range of print repeat sizes possible using the selected sleeve circumferences. The center of rotation 44 of the impression cylinder 16 is thus displaceable, by the pivot arms 40, along the impression cylinder adjustment arc 42. Once the impression cylinder 16 is positioned in the desired location on the displacement arc 42, it can be fixed in position such that the contact stripe between the blanket cylinder 14 and the impression cylinder 16 is maintained, and the impression cylinder 16 can nevertheless rotate about its central rotation axis 44. The impression cylinder 16 is accordingly always the same size, regardless of the chosen circumferences of the plate and blanket cylinders 12,14. Referring now to FIGS. 2 to 4, a single drive motor 71, which directly drives the plate cylinder 12 of the printing unit 15, and the plate cylinder 12 is linked with the blanket cylinder 14 by a drive linkage mechanism 70. The drive motor 71 can either be coaxially arranged with the plate cylinder (as shown in FIG. 4) or offset therefrom and interlinked by an idler gear. When the drive motor is said to “directly drive” the plate cylinder herein, it is to be understood that this includes the embodiment in which the plate cylinder gear and the drive motor are offset from each other and linked by an idler gear meshed therebetween. As best seen in FIG. 2, the drive linkage mechanism 70 comprises a blanket cylinder gear 76 and a plate cylinder gear 72, disposed on common ends of each respective cylinder. First and second idler gears 74 and 75, intermeshed with each other and the plate cylinder gear 72 and the blanket cylinder gear 76 respectively, complete the gear train between the two cylinders. The drive linkage mechanism 70 comprises a first linkage arm 78 and a second linkage arm 80, relatively pivotal with respect to each other about a first pivot axis 79, which is preferably coaxial with the shaft of the second idler gear 75 in meshing engagement with the blanket cylinder gear 76. The first linkage arm 78 is also pivotal about the central axis 46 of the plate cylinder 12. The first linkage arm 78 comprises a lateral retaining mechanism 82 which engages the frame structure 18 such that substantial lateral movement of the linkage arms is prevented. Accordingly, the drive linkage mechanism 70 ensures that the distance between the central axes of the plate cylinder gear 72 and the first idler gear 74 remains constant, as does the distance between the blanket cylinder gear 76 and the second idler gear 75. The two idler gears remain intermeshed regardless of the positions of the first and second linkage arms 78 and 80. Accordingly, the drive linkage mechanism 70 permits the distance between the central axes 46 and 48 of the plate cylinder 12 and the blanket cylinder 14 to be varied, without disengaging the gear train linkage therebetween. This enables the gear mesh through the gear train to be maintained, even as the cylinders are moved relative to each other. The blanket cylinder 14 can accordingly be translated along the blanket cylinder displacement line 43, the translating bearing-blocks 63, within which the trunnions 49a,b of the blanket cylinder are mounted, sliding in the correspondingly shaped slot 84 defined in the frame structure 18, without having to disengage to the gear train. This therefore permits sleeves of various diameters to be used, thereby requiring various positions of the cylinders, without having to disengage or reset the mechanical gear linkage between the plate and blanket cylinders. This represents a significant time savings and makes modifying the printing press to vary the repeat length of the printed product much easier. In some prior art systems which permit for interchangeable cylinders or cylinder sleeves, the gear ring for each cylinder must also be changed at the same time as the sleeve thereon. This is not true of the present drive train and linkage mechanism, as the gears remain intermeshed regardless of the position of the cylinders, and the drive motor can be driven at a selected angular speed required to accommodate the chosen sleeve diameters. The impression cylinder 16 is preferably driven by a smaller transfer gear 64, located at the pivot point 41 of the impression cylinder 16, which can be driven by an independent drive motor or the press main drive. FIG. 3a discloses the drive linkage mechanism 70 of the printing unit 15, wherein the plate cylinder 12 and the blanket cylinder 14 have smallest sized cylinder sleeves thereon. Accordingly, the blanket cylinder 14 is located in an uppermost position within the slot 84. FIG. 3b depicts the printing unit, wherein the cylinder sleeves of the plate and blanket cylinders 12,14 have been interchanged for ones having a larger outer diameter. Accordingly, the spacing necessary between the central axes of the two cylinders is much greater, such that the larger diameters of the cylinders can be accommodated. The blanket cylinder is therefore displaced, along the blanket cylinder displacement line 43, to the lower end of the slot 84 in the frame. This is done without having to disengage the gear train linkage between the plate and blanket cylinders. Particularly, by sliding the bearing blocks of the blanket cylinder downward, the second linkage arm 80 is forced to pivot downward about the first pivot axis 79 and the first linkage arm 78 correspondingly moves by slightly pivoting about the central axis 46 of the plate cylinder 12. The idler gears 74 and 75 maintain intermeshed engagement, with each other and the plate and blanket cylinder gears respectively, during the full range of movement. Further, by accurately controlling the movement of the drive linkage mechanism 70, the contact stripe between the plate cylinder 12 and the blanket cylinder 14 can also be precisely selected. Referring now back to FIG. 4, the trunnions 47a and 49a of the plate cylinder 12 and the blanket cylinder 14 respectively, are adapted for translation within the frame structure 18 in a direction 51 parallel to, and more particularly coaxially with, the central axes 46 and 48 of the plate and blanket cylinders respectively. In order to permit the complete removal of the plate and blanket cylinders from the press, the trunnions 47a,49a can be slid outwardly, thereby disengaged the inner ends of the trunnions 47a,b and 49a,b from the outer ends of the central mandrel shafts 52 and 58 of the plate and blanket cylinders respectively. The trunnions 47a,49a are only required to outwardly translate by a distance large enough to permit the cylinder to drop out from the inner ends of the trunnions. While the trunnions 47b,49b are preferably fixed, it is to be understood that these trunnions could also similarly be axially displaced simultaneously with the trunnions 47a,49a to engage and disengage both ends of the plate and blanket cylinders. The trunnions 47a,49a of each cylinder can be independently operated, such that each cylinder can be selectively removed when desired. This can be done either remotely, such as by a pneumatically operated mechanism, or manually. The translation of the trunnions does not affect the position of the gear train and drive linkage mechanism 70, which remain substantially laterally fixed in place regardless of whether the trunnions are in the engaged mode, wherein the trunnions and central mandrel shafts are pressed into engagement such that no relative rotation therebetween is possible, or in the disengaged mode, wherein the cylinders can be completely removed from the press. Thus, removal of the cylinders is possible without having to remove or disengage the bearings, within which the cylinder trunnions rotate, from the frame structure 18 of the printing unit 15. Additionally, the sleeves can be easily changed on the central mandrel shafts once they have been removed from the press. The plate cylinder 12 is also preferably provided with a lateral adjustment mechanism, driven by an independent motor, which allows the press operator to make slight lateral adjustments in the position of the plate cylinder 12 relative to the blanket cylinder 14. This permits fine lateral relative adjustment of the two cylinders to ensure a precise contact stripe therebetween. The dampening unit 22 and the inking unit 20 are preferably driven by the same drive used for the impression cylinder 16. A servo motor drive, independent of the main motor 71 used to drive the plate cylinder 12, is preferably provided for the impression cylinder 16. However, this impression cylinder servo drive is preferably only used to make small adjustments to the speed of the impression cylinder (ie: to “trim” the speed) and is therefore used for control rather than power. The main drive power for the impression cylinder 16 is preferably provided by the main press gear linkage. In order to provide the maximum mechanical rigidity of the blanket cylinder 14, and in order to eliminate issues of imprecise impression setting repeatability, an impression “throw off/on” control is further preferably provided. The impression throw-off feature permits the plate cylinder 12 and the impression cylinder 16 to be displaced by a small preset amount, such that they are disengaged from contact with the blanket cylinder 14. This permits printing to be interrupted, without having to drastically displace the cylinders relative to each other, and permits printing to be easily re-started, without having to precisely reset the contact stripes between the cylinders. As described above, the plate cylinder can be “thrown-off” to stop printing by being eccentrically mounted in the rotatable mounting assembly 53. Thus, the rotatable mounting assembly 53 can be rotated within the frame structure 18, such that the plate cylinder is slightly displaced away from the blanket cylinder. The impression cylinder 16 is also disengageable from the blanket cylinder 14 by an adjustment mechanism 86, described in greater detail below. Particularly referring to FIGS. 5a and 5b, the impression cylinder adjustment mechanism 86 comprises a first actuator 81, such as a pneumatic cylinder for example, having a first translating end 83 which is pivotably engaged to the impression cylinder pivot arm 40. A second, opposed end 85 of the first actuator 81 is pivotably engaged to an eccentric mounting assembly 87 which is rotatable within the frame structure 18 of the printing unit 15. The eccentric rotating assembly 87 of the first actuator 81 is rotatable by a second actuator 89, preferably a smaller pneumatic cylinder. A first translating end 95 of the second actuator 89 is engaged to the eccentric rotating assembly 87 by a link member 88. Each end of the link member 88 is respectively pivotably connected with the translating end 95 of the second actuator 89 and the second end 85 of the first actuator which is eccentrically engaged to the rotating assembly 87. A second end 97 of the second actuator 89 is not displaceable, but is pivotably fixed to the frame structure 18. Accordingly, the first actuator 81 is used for impression adjustment, such that the impression cylinder can be displaced to accommodate the particular size of blanket and plate cylinders being employed, and to control the contact pressure between the impression cylinder 16 and the blanket cylinder 14. By extending or retracting the first translating end 83 of the first actuator 81, the impression cylinder pivot arm 44 is thus pivoted such that the impression cylinder 16 displaced as required. The first actuator 81 preferably has a relatively large travel, such that plate and blanket cylinder of various sizes can be accommodated. However, the first actuator is also preferably precisely controlled, such that a desired contact pressure between the impression cylinder 16 and the blanket cylinder 14 can be set. Once this is set, the first actuator 81 is locked, such that the relative positions of the first and second ends thereof are fixed. The second actuator 89 of the impression cylinder adjustment mechanism 86 is used to “throw-on” or “throw-off” the impression cylinder 16, such that printing can be started or stopped when required. Displacing the translating end 95 of the second actuator 89 acts to rotate the eccentric rotating assembly 87 within the frame structure 18, thereby slightly displacing the second end 85 of the locked first actuator 81 by a slight distance, which accordingly disengages the impression cylinder 16 from contact with web 11 and the blanket cylinder 14 by said slight distance. This slight distance generally corresponds to the eccentricity of the second end 85 of the first actuator 81 relative to the center of rotation of the rotating assembly 87. Thus, the precise location of the impression cylinder and the contact stripe relative to the blanket cylinder can be preset by the first actuator 81 and then locked in position, and the second actuator 89 can be activated to easily engage and disengaged the impression cylinder 16 with the blanket cylinder 14, without having to reset the position and contact stripe each time. The embodiments of the invention described above are intended to be exemplary. Those skilled in the art will therefore appreciate that the forgoing description is illustrative only, and that various alternatives and modifications can be devised without departing from the spirit of the present invention. Accordingly, the present is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Offset printing presses are well known in the art. Typically, water and ink are supplied to a printing plate cylinder, and are then transferred to a blanket cylinder for printing onto sheets or web, fed between the blanket cylinder and an impression cylinder. The water supply to the plate cylinder usually comprises a dampening unit having a dampening form roller which contacts the plate cylinder and is fed water from a water pan through intermediate water transferring rollers. Similarly, an inking unit transfers ink from an ink supply to the plate cylinder through an ink transfer and application rollers. While such presses have fixed lateral dimensions, and as such printed products wider than the length of the cylinders cannot be produced, the circumference of the rotating cylinders determines the length of each repeated pattern being printed onto the web or sheets passing therethrough. Accordingly, the larger the circumference of the plate and blanket cylinders being used, the longer the printed pattern that can be produced. Therefore, in order to permit a press to be modified to permit printing of difference sized “repeats”, or each repeated pattern that is printed onto the web for each revolution of the cylinders, it is desirable to be able to use plate and blanket cylinders of different circumferences in order to be able to vary the repeat size provided by the press. To achieve this desired press convertibility, it has been know to provide an offset press with a removable cylinder cartridge, having at least the plate and blanket cylinders mounted therein. For such a cartridge to be removed from the rest of the printing press, the cylinders must be disengaged from one another, and the entire cartridge is slid out as a single unit from the frame of the press. A replacement cartridge having therein plate and blanket cylinders of a smaller or larger circumference, is then inserted into the press in place of the original cartridge. This therefore permits the press to be converted to change the size of the repeat produced with each rotation of the press cylinders. While this solution provides the press with repeat size flexibility, each cartridge is large and costly, and therefore the practical range of flexibility is generally limited by the cost and space considerations of keeping many different cartridges having cylinders of various sizes. Various printing presses having removable cylinders are also known. However, to permit the removal of the cylinders requires them to be disengageable from one another. The precisely set contact stripe between the cylinders is therefore often lost. Further, this typically also requires that the intermeshed gears driving the cylinders can be completely disengaged from each other every time a cylinder is to be removed, and easily re-engaged once a new replacement cylinder is introduced into the press. A known way to avoid this problem is to completely replace the gear train by drive motors used to drive the cylinders at the necessary speeds. Particularly, some presses employ a drive motor for each cylinder, thereby circumventing the requirement of gear trains completely. However, printing presses which are completely driven by servo drive systems are more expensive and more complex than those which use traditional gear train drives. Further, if any of the drive motors are incorrectly set or malfunction, the resultant mismatch in cylinder speeds can cause defective printed product or damage to the press. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide an offset printing press with independently removable plate and blanket cylinders. It is also an object of the present invention to provide an offset printing press having plate and blanket cylinders with replaceable outer sleeves. It is an object of the present invention to provide an offset printing press having a cylinder drive linkage mechanism which maintains gear mesh when cylinders are disengaged from one another. It is another object of the present invention to provide a variable form roller throw-off and strip adjustment mechanism for an offset printing press. Therefore in accordance with the present invention, there is provided an offset printing press comprising: a plate cylinder, a blanket cylinder and an impression cylinder each mounted in a frame structure for rotation about parallel individual axes of rotation, the plate cylinder and the blanket cylinder having a common outer circumference defining a print repeat size produced by the plate and blanket cylinders; plate and blanket cylinder retention mechanisms respectively engaging the plate cylinder and the blanket cylinder, each retention mechanism comprising first and second trunnions rotatable within the frame structure and respectively engageable to a corresponding cylinder end, at least one of said first and second trunnions being axially displaceable by an actuating member between an operative position and a disengaged position, said at least one trunnion being fastenable in mating engagement with said corresponding cylinder end in the operative position and freely disconnected from said corresponding cylinder end in the disengaged position, such that the plate cylinder and the blanket cylinder are removable from the printing press from between the frame structure; and wherein at least one of the plate and blanket cylinder retention mechanisms is selectively displaceable relative to the frame structure such that a distance between the axes of rotation is variable, said at least one cylinder retention mechanism being fastenable in a desired position to maintain the distance at a predetermined value; whereby the plate and blanket cylinders are removable from the printing press and substitutable with replacement cylinders having a different outer circumference, thereby providing a correspondingly different sized print repeat when the replacement cylinders are installed into the printing press. There is also provided, in accordance with the present invention, a cylinder drive system for an offset printing press having a plate cylinder and a blanket cylinder mounted in a frame structure such that a distance between axes of rotation thereof is selectively variable, the cylinder drive system comprising: a drive motor operatively connected to one of the plate cylinder and the blanket cylinder to provide driven rotation thereto; a gear drive linkage mechanism operably inter-engaging the plate cylinder and the blanket cylinder such that the drive motor drives both the plate and blanket cylinders; and wherein the gear drive linkage mechanism remains in gear meshed engagement with both the plate cylinder and the blanket cylinder regardless of the variable relative positions thereof. There may also be provided, in accordance with the present invention, an offset printing press including a plate cylinder, a blanket cylinder and an impression cylinder mounted in a frame structure in serial contactable engagement, the printing press comprising a cylinder adjustment mechanism operable to displace at least one of the plate cylinder and the impression cylinder between a predetermined printing position, wherein said at least one of the plate cylinder and the impression cylinder is in contacting engagement with the blanket cylinder, and a disengaged position, wherein said at least one of the plate cylinder and the impression cylinder is removed from contacting engagement with the blanket cylinder, the cylinder adjustment mechanism being selectively actuable and providing controlled variable displacement of said at least one of the plate cylinder and the impression cylinder relative to the blanket cylinder. | 20040128 | 20060314 | 20050728 | 74554.0 | 1 | EVANISKO, LESLIE J | OFFSET PRINTING PRESS UNIT WITH REMOVABLE CYLINDERS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,765,116 | ACCEPTED | Data acquisition, control, and spectral analysis software for multi-channel analyzers | A system for detecting and identifying low-level (weak) radioactive sources moving past stationary detectors. The system, which can detect low-level sources moving at speeds of 30 m/s (about 70 mph), uses the differences between background counts and gamma counts from a moving source to determine that a source has passed the detector, when a source has passed the detector, and the identification of the source. This system has been demonstrated to work successfully for ordinary passenger vehicles transporting a variety of sources, and also for boats at lower speeds on a waterway. | 1. A method for detecting and identifying low-level radioactive sources moving past at least two stationary detectors, comprising the steps of: determining and storing background spectra for each of a first detector and a second detector, said background spectra representing an expected number of background counts in a channel for a period of time corresponding to an acquisition time slice, j; inputting from said first detector and said second detector a first and second number of counts, respectively, in the channel during the acquisition time slice, j; calculating a first probability that said first number of counts is due to said background spectra; calculating a second probability that said second number of counts is due to said background spectra; comparing said first and second probabilities to a threshold; in response to both said first and said second probabilities being below said threshold, identifying a source of said first and second number of counts as a radioactive source; and in response to only one or neither of said first and said second probabilities being below said threshold, adding said first and second number of counts to said background spectra. 2. The method as set forth in claim 1, wherein said acquisition time slice, j, is one-third to one-half of a smallest expected interaction time. 3. The method as set forth in claim 1, further comprising the steps of: inputting from said first detector and said second detector, respectively, a previous number of counts during an acquisition time slice, j−1; comparing said first and second number of counts with said previous number of counts; and in response to a correlation between said first and said number of counts and said previous number of counts, identifying the source of said first and second number of counts as a radioactive source; and in response to only one or neither of said first and said number of counts correlating with said previous number of counts, identifying the count source as background spectra. 4. The method as set forth in claim 1, further comprising the steps of: inputting from said first detector and said second detector, respectively, a previous number of counts during an acquisition time slice, j−1, and a subsequent number of counts during an acquisition time slice, j+1; comparing said first and second number of counts with said previous and said subsequent number of counts during time slices j−1, j+1; and in response to a correlation between said first and said number of counts and at least one of said previous and subsequent number of counts, identifying the source of said first and second number of counts as a radioactive source; and in response to only one or neither of said first and said number of counts correlating with said previous or subsequent number of counts, identifying the count source as background spectra. 5. The method as set forth in claim 1, further comprising the steps of: inputting from said first detector and said second detector, respectively, a third and fourth number of counts from another channel adjacent said channel; comparing said first and second number of counts with said third and fourth number of counts, respectively; and in response to a correlation between said first and said number of counts and said third and fourth number of counts, identifying the source of said first, second, third and fourth number of counts as a radioactive source; and in response to only one or neither of said first and said number of counts correlating with said third and fourth number of counts, identifying the count source as background spectra. 6. The method as set forth in claim 5, wherein a plurality of adjacent channels are input for count comparison, a number of said plurality of adjacent channels increasing with a numeric value of said channel. 7. The method as set forth in claim 6, wherein the numeric value of said channel is between 26-75, and the number of said plurality of adjacent channels from which count sums are taken is three. 8. The method as set forth in claim 6, wherein the numeric value of said channel is between 76-125, and the number of said plurality of adjacent channels from which count sums are taken is five. 9. The method as set forth in claim 6, wherein the numeric value of said channel is between 126-175, and the number of said plurality of adjacent channels from which count sums are taken is seven. 10. The method as set forth in claim 6, wherein the numeric value of said channel is between 176-250, and the number of said plurality of adjacent channels from which count sums are taken is nine. 11. A method for detecting and identifying low-level radioactive sources moving past at least two detectors, comprising the steps of: determining and storing background spectra for each of a first detector and a second detector, said background spectra representing an expected number of background counts in an energy bin for a period of time corresponding to an acquisition time slice; inputting from said first detector and said second detector a first and second number of counts, respectively, in the energy bin during the acquisition time slice; calculating a first probability that said first number of counts is due to said background spectra; calculating a second probability that said second number of counts is due to said background spectra; comparing said first and second probabilities to a first threshold and a second threshold, said first threshold being greater than said second threshold; in response to both said first and said second probabilities being less than said first threshold, or to either said first and said second probabilities being less than said second threshold, identifying a source of said first and second number of counts as a radioactive source; in response to only one or neither of said first and said second probabilities being less than said first threshold, adding said first and second number of counts to said background spectra. 12. The method as set forth in claim 11, wherein said energy bin includes a plurality of adjacent channels, said first and second probabilities representing a sum of probabilities obtained from said plurality of channels. 13. The method as set forth in claim 11, wherein said step of inputting includes inputting counts from said first and second detectors for at least two sequential time slices, said first and second probabilities being calculated by adding probabilities obtained from counts for each time slice. 14. The method as set forth in claim 11, wherein said first threshold has a value of approximately 10−6 and said second threshold has a value of approximately 10−9. 15. The method as set forth in claim 1, further comprising the steps of: inputting from said first detector and said second detector, respectively, a previous number of counts received by each detector during an acquisition time slice, j−1; adding said first and second number of counts with said previous number of counts, respectively to obtain first and second sums; and performing said steps of calculating the first and second probabilities using said first and second sums. 16. The method as set forth in claim 1, further comprising the steps of: inputting from said first detector and said second detector, respectively, a previous number of counts received by each detector during an acquisition time slice, j−1, and a subsequent number of counts during an acquisition time slice, j+1; adding each of said first and second number of counts with respective previous and subsequent numbers of counts, to obtain first and second sums; and performing said steps of calculating the first and second probabilities using said first and second sums. 17. The method as set forth in claim 1, further comprising the steps of: inputting from said first detector and said second detector, respectively, a third and fourth number of counts from another channel adjacent said channel; adding said first and second number of counts with said third and fourth number of counts, respectively, to obtain first and second sums; and performing said steps of calculating the first and second probabilities using said first and second sums. 18. A method for detecting and identifying low-level radioactive sources moving past at least two detectors, comprising the steps of: determining and storing background spectra for each of a first detector and a second detector, said background spectra representing an expected number of background counts in an energy bin for a period of time corresponding to an acquisition time slice; inputting from said first detector and said second detector a first and second number of counts, respectively, in the energy bin during the acquisition time slice; calculating a first probability that said first number of counts is due to said background spectra; calculating a second probability that said second number of counts is due to said background spectra; inputting from said first detector-and said second detector a third and fourth number of counts, respectively, in the energy bin during a subsequent adjacent acquisition time slice; calculating a third probability that said third number of counts is due to said background spectra; calculating a fourth probability that said fourth number of counts is due to said background spectra; adding said first and third probabilities to obtain a first probability sum; adding said second and fourth probabilities to obtain a second probability sum; comparing said first and second probability sums to a first threshold and a second threshold, said first threshold being greater than said second threshold; in response to both said first and said second probability sums being less than said first threshold, or to either said first or said second probability sum being less than said second threshold, identifying a source of said counts as a radioactive source; in response to only one or neither of said first and said second probability sums being less than said first threshold, adding said first, second, third and fourth number of counts to said background spectra. 19. The method as set forth in claim 18, wherein said first threshold has a value of approximately 10−6 and said second threshold has a value of approximately 10−9. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is related to the field of radioactive source identification and, more particularly, to a device for detecting and identifying low-level radioactive sources moving past stationary detectors. 2. Description of the Related Art According to the prior art, detection of radioactive sources has not been accomplished at full highway speeds, a scenario known as drive-by or pass-by detection, and certainly real-time identification of sources at these speeds has not been possible. By contrast, most nuclear radiation detection is done using a detector and source that are both stationary. Since, due to source speed, the interaction time of the radioactive source with the detector is short in a drive-by detection scenario, detector counting time must also be short. This leads to many counting intervals each second. In order for the system to be sensitive, it must be capable of reacting to a small number of counts. However, if the system reacts to a small number of counts, it is possible that normal background fluctuations may activate the system. The high frequency of the time slices thus forces the threshold of the system to be high, to keep the false alarm rate low, but a high threshold is inconsistent with sensitivity to a low count source. Therefore, a need exists for a system that is able to detect radioactive sources moving at highway speeds, having high sensitivity coupled with substantial resistance to false alarms. SUMMARY OF THE INVENTION In view of the foregoing, one object of the present invention is to overcome the difficulties associated with detection of low-level radiation sources in drive-by or pass-by detection scenarios. Another object of the present invention is to provide a detector that counts in small time slices on the order of one eighth of a second to accommodate the high speed of the source. A further object of the present invention is to provide a detector that uses the differences between source counts and background counts to distinguish between the two, providing the high sensitivity with low false alarm rate needed for such a system to be useful. In accordance with these and other objects, the present invention is directed to a method for detecting and identifying low-level radioactive sources moving past at least two stationary detectors by comparing stored background spectra representing an expected number of counts over one or more time slices in one or more channels for each of the detectors with currently received spectra in a corresponding time period and channel range for each detector. A probability that the number of counts received by each of the detectors is attributable to background is calculated and, depending upon the relationship of the two probabilities to each other and to a threshold value, it is determined whether or not the source of the counts is a radioactive source. These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of the hardware for a detector system in accordance with the present invention; FIG. 2 illustrates a representative photopeak for radioactive cesium (137Cs); FIG. 3 is a graph of an expected number of background counts in a 0.125 second time slice (riτ); FIG. 4 is a graph of the counts required to exceed probability levels in a single detector, single time slice; and FIG. 5 is a flowchart of the hit detection process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. As shown in FIG. 1, the system includes two or more NaI(Tl) detectors 10, each including a sodium iodide (NaI) crystal with an associated photomultiplier tube (PMT) and electronics. The NaI crystals are sensitive to gamma rays from a radioactive source, producing a flash of light in response to absorption of these rays which is detected and processed by the PMT and electronics for further processing by a respective one of a plurality of multichannel analyzers 20 which are, in turn, coupled to an internal memory 30 within a control computer 40. Each multichannel analyzer (MCA) 20 provides the energy vs. count distribution for a respectively connected NaI detector 10. As the potential interaction time is very short (˜0.2-0.3 seconds), the MCA must acquire data in very small time slices (˜0.1-0.125 seconds). For the hit determination algorithm to work optimally, the acquisition time slices must be about one-third to one-half of the smallest expected interaction time. In the short interaction time used, the relative fluctuations of counts in any given channel may be quite large. However, as there are certain indicators that typically accompany source versus background counts, the spectra obtained from the MCA's are checked for events that are not likely to have come from background fluctuations. Background fluctuations have three main characteristics that are important to the effective operation of the system according to the present invention. First, background counts are not correlated with respect to channel numbers. Therefore, if there is a count in channel i, there is no greater probability of a count appearing in channel i−1 or channel i+1. Second, background counts are not correlated with respect to time slice; if there is a count in channel i during time slice j, then there is no greater probability of a count appearing in time slice j−1 or j+1. Third, background counts are not correlated with respect to detector such that, if there is a count in channel i of detector 1, there is no greater probability of there being a count in channel i of detector 2. Counts from sources follow different patterns from those demonstrated by background counts. Particularly, counts from sources tend to group around the source photopeak such that there exists a channel or group of channels where source counts are more likely to occur, depending on the γ energy of the source. As previously noted, the NaI detectors produce a flash of light in response to gamma ray absorption. For gamma rays that have all of their energy converted to light, i.e., they are completely absorbed, the MCA puts those counts into a few channels which represent the photopeak for that source, while gamma rays that are not completely converted to light occur in what is known by those of skill in the art as the Compton Continuum; a representative photopeak and Compton Continuum for a cesium source(137Cs) is shown in FIG. 2. Next, source counts arrive only during time slices during which the source was close to the detector. Thus, if for two to three time slices there are counts in channel i during time slice j, there will be a greater probability of counts occurring during time slice j−1 or j+1 if the counts arise from a radioactive source. Finally, source counts are correlated with respect to detector; if counts from a source occur in channel i of detector 1, there is a greater probability of counts occurring in channel i of detector 2, assuming proper calibration of the two detectors. Accordingly, the analysis algorithm according to the present invention looks for the correlations that are unique to source counts. When events with a high degree of correlation consistent with source counts appear, they are counted as a source. The power of the technique is that the probability of the predictable patterns caused by γ ray sources occurring as a result of background fluctuations is so small as to be virtually non-existent. Analysis Algorithm In a given channel, the mean number of counts expected from the background during a time slice is given by Poisson statistics Pi(n)=(riτ)n exp (−riτ)/n!, Equation 1 where Pi(n) is the probability of obtaining n counts in channel i, ri is the background rate of channel i, σ is the counting or acquisition time of the time slice, and n is the number of counts in channel i. With the value of riσ representing the background spectra, the hit detection algorithm takes the number of counts in a channel and calculates the probability that the counts came from the background. If the probability is below a threshold, it is assumed that the counts did not come from background fluctuation, that is, the counts came from a nearby radioactive source. For illustration, the background shown in FIG. 3 was accumulated over 1000 seconds, and scaled to give the expected number of counts in a 0.125 second time slice. For this particular detector, at this particular time, the expected number of background counts in a 0.125 second time slice is less than one in all channels; these are the values of riτ used in Equation 1. A spectrum is checked by using the actual number of counts that occurred in each channel during the time slice (n in Equation 1). If the probability that the fluctuation is due to background is sufficiently small, a hit is considered to have occurred. The number of counts required to exceed various probability levels is shown in FIG. 4. Simply obtaining counts above a predetermined threshold level in a channel is not sufficient to qualify an event, however. There must also be counts in the other detector in the same channel. This is because background counts are not correlated across the detectors. Only sources give counts simultaneously in both detectors. Comparing the counts of two or more detectors, and noting as a source only those instances in which both detectors register counts, is one of the main ways in which false alarms due to background fluctuations are reduced. In this way, the required count threshold for a single detector can be set quite low, while still yielding a low rate of false alarm. The sensitivity of the system is increased by using correlations across time slices and across the energy spectra. As previously identified, background counts do not correlate from one time slice to the next. Instead, the time correlations are seen only while a radioactive source is passing in front of the detector. Events with a low probability due to background fluctuations that repeat from time slice to time slice are a unique signature of a passing radioactive source. Finally, most photopeaks occur in more than one channel. When a source is present, the counts over a region of channels or energy bins increases. This is another signature unique to radioactive sources. Furthermore, the width of a peak varies with channel number. The larger the bin or channel number, the wider the peak. The analysis program of the present invention looks for anomalous numbers of counts over regions consistent with the width of a predicted source photopeak. Basic Implementation Background spectrum is first obtained for the 256 channels in the spectrum and recorded over some period of time, typically 1000 seconds, as was undertaken to obtain the background in FIG. 3. At 1000 seconds of counting time there is a low probability that there will be zero counts in a channel, i.e., that ri will be zero. The average number of counts that could be expected per second is then found by dividing each channel by the 1000 second acquisition time. The Poisson formula is written in natural log form as −ln(Pi(n))=riτ+ln(n!)−n(ln(ri)+ln(τ)) Equation 2 Given the small probabilities being used, this implementation reduces round off errors and provides values that are more easily implemented. As the formula uses the natural log of the scattering rate, a value of zero for ri must be avoided. The long background acquisition time (1000 seconds) helps to avoid this pathological situation. Also, the program checks for a value of zero in background bins. Any bin with a zero is changed to a value of one. Since the acquisition time τ actually varies slightly from time slice to time slice, this number is measured and the actual acquisition time is used in the calculation. The average scattering or background rate ri is contained in a 256 element array, as is the ln(ri). The natural logs of n! from 0-50 are also pre-computed, and stored in an array. Values of n greater than 50 use ln(50!) . At the highest background rate, the peak number of counts expected in a time slice is a little greater than one, and the probability of more than 50 counts occurring due to background alone is so low as to be meaningless. The negative of the natural log is used to make hits appear as positive numbers. The probability values for a 256 channel spectrum can be calculated in about 50 τs. In the two-detector system, there are 50 ms of time within which to do the hit calculations, so with the current algorithm there are no calculation time issues. Counts from the photopeak usually occur over a number of channels. The width of the peak increases with increasing channel number. Because of this, the value of ri is actually the mean number of counts expected over a number of adjacent channels, with the number of adjacent channels corresponding with the expected width of the photopeak. The number of channels to be summed, i.e., the width of the window, for the current spectra corresponds with the width of the window taken when determining the background or scattering rate. This number of channels used in the sum is shown in Table 1. FIG. 5 provides a conceptual overview of the hit detection process. Background spectra (μn) is stored for each detector, step 70, with μn being the average number of counts over the number of channels constituting the expected photopeak width. Spectra from each detector is then collected, step 72, and the probability of the counts from each channel having resulted from background is computed, step 74, using the following formula, Pn=(μn)c exp (−μn)/c! Equation 3 where c is the number of counts from the current spectra over the same number of channels used to obtain μn. Spectra determined to exceed a probability threshold in corresponding channels of the two detectors, step 76, is identified as a “hit” arising from a radioactive source, step 78. Spectra which does not demonstrate this correlation is added to the background spectra, step 80, whether for the first detector 70a or the second detector 70b. The process of FIG. 5 may be repeated for spectra from consecutive time slices to identify those spectra also showing correlation across two or more sequential time slices, with the probabilities from multiple time slices being summed and compared with threshold values to determine whether or not the spectra represents a hit. For channels 0-25, the calculated probability is based on one channel and two time slices. This means −ln(Pi) from the preceding time slice is added to the present probability. The previous two time slices for the second detector are also summed and, if the count probability from each detector is above some minimum threshold, the event is classified as a radioactive source. Alternatively, in considering multiple time slices, the probability 74a obtained from two slices with the first detector 72a may be added to the probability 74b for the corresponding two time slices for the second detector 72b, and if the resulting sum is above a threshold, the event is classified as a radioactive source provided that the count probability from each detector is also above some minimum threshold. This reduces the probability that a large background fluctuation in one detector could be mistaken for a radioactive source. If the event passes both of these tests, it is considered to be caused by a passing source. TABLE 1 Summing width as a function of channel number Number of Channel summed Numbers channels 0-25 1 (i) 26-75 3 (i +/− 1) 76-125 5 (i +/− 2) 126-175 7 (i +/− 3) 176-250 9 (i +/− 4) The calculations are similar for energy bins greater than channel 25. However, because the photopeaks are spreading with higher channel numbers, the number of channels over which the probabilities must be summed increases. For channels 26-75, the probability for channel i is calculated by summing counts over three channels. The number of channels used in the sum is determined by measuring the e−1 peak width as a function of peak channel number. The same time steps taken with regard to time slice and detector are then performed with this probability. A spectrum is analyzed for a hit by using Equation 2. The probability that the number of counts over the channels occurred due to background is calculated. This probability of occurrence vs. channel number is summed with the natural log of the probabilities from the previous time slice. Since a source is expected to be in the field of view for at least two time slices, counts from sources should be elevated over two adjacent time slices. This is compared with the probability vs. channel number of the other detector. Currently, if either of the detectors has a channel with probability due to background of less than 10−9, or if both detectors have a channel (the same channel in each detector) with a probability of less than 10−6, the event is counted as a radioactive source. These numbers have not been optimized with respect to sensitivity and false alarm rate. The values were sufficient for the sources used in system demonstrations. System sensitivity can be estimated from FIG. 4. With the current threshold values used (both detectors must be showing a two-time slice probability of 10−6) the number of counts required as a function of channel can be calculated. For lower energy channels (channels 0-25) with higher background rates, about three to four counts/time slice must be reported from each detector in order for the event to be counted as a radioactive source. Higher energy channels, with lower backgrounds, will be reported as a hit if one or two counts/time slice are observed in each detector, in the same energy bin. The system described herein applies to other radiation detectors using a multi-channel analyzer, such as cesium iodide (CsI) and high-purity germanium (HPGe) detectors. In the case of detectors capable of high spectral resolution, such as HPGe, the software would be required to operate with a larger number of channels in many applications. This change is a straightforward extension of the current system. The foregoing descriptions and drawings should be considered as illustrative only of the principles of the invention. The invention may be otherwise configured and is not limited to the configurations of the preferred embodiment. Numerous applications of the present invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention is related to the field of radioactive source identification and, more particularly, to a device for detecting and identifying low-level radioactive sources moving past stationary detectors. 2. Description of the Related Art According to the prior art, detection of radioactive sources has not been accomplished at full highway speeds, a scenario known as drive-by or pass-by detection, and certainly real-time identification of sources at these speeds has not been possible. By contrast, most nuclear radiation detection is done using a detector and source that are both stationary. Since, due to source speed, the interaction time of the radioactive source with the detector is short in a drive-by detection scenario, detector counting time must also be short. This leads to many counting intervals each second. In order for the system to be sensitive, it must be capable of reacting to a small number of counts. However, if the system reacts to a small number of counts, it is possible that normal background fluctuations may activate the system. The high frequency of the time slices thus forces the threshold of the system to be high, to keep the false alarm rate low, but a high threshold is inconsistent with sensitivity to a low count source. Therefore, a need exists for a system that is able to detect radioactive sources moving at highway speeds, having high sensitivity coupled with substantial resistance to false alarms. | <SOH> SUMMARY OF THE INVENTION <EOH>In view of the foregoing, one object of the present invention is to overcome the difficulties associated with detection of low-level radiation sources in drive-by or pass-by detection scenarios. Another object of the present invention is to provide a detector that counts in small time slices on the order of one eighth of a second to accommodate the high speed of the source. A further object of the present invention is to provide a detector that uses the differences between source counts and background counts to distinguish between the two, providing the high sensitivity with low false alarm rate needed for such a system to be useful. In accordance with these and other objects, the present invention is directed to a method for detecting and identifying low-level radioactive sources moving past at least two stationary detectors by comparing stored background spectra representing an expected number of counts over one or more time slices in one or more channels for each of the detectors with currently received spectra in a corresponding time period and channel range for each detector. A probability that the number of counts received by each of the detectors is attributable to background is calculated and, depending upon the relationship of the two probabilities to each other and to a threshold value, it is determined whether or not the source of the counts is a radioactive source. These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. | 20040128 | 20070904 | 20050728 | 64962.0 | 0 | GAGLIARDI, ALBERT J | DATA ACQUISITION, CONTROL, AND SPECTRAL ANALYSIS SOFTWARE FOR MULTI-CHANNEL ANALYZERS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,765,338 | ACCEPTED | Methods and system for creating and managing identity oriented networked communication | A software application for managing routing of communiqués across one or more communication channels supported by a data-packet-network includes one or more workspaces for segregating communication activity; one or more unique user identities assigned per workspace; and one or more contact identities assigned to and approved to communicate with a workspace administrator of the one or more workspaces using the assigned user identities. In a preferred embodiment the application enforces a policy implicitly defined by the existing architecture of the workspaces and associated user and contact identities. | 1. A software application for managing routing of communiqués across one or more communication channels supported by a data-packet-network comprising: one or more workspaces for segregating communication activity; one or more unique user identities assigned per workspace; and one or more contact identities assigned to and approved to communicate with a workspace administrator of the one or more workspaces using the assigned user identities; characterized in that the application enforces a policy implicitly defined by the existing architecture of the workspaces and associated user and contact identities. 2. The application of claim 1 wherein the data-packet-network is the Internet network. 3. The application of claim 1 wherein the one or more workspaces are created zones segregated primarily by genre. 4. The application of claim 1 wherein a user identity relates to a workspace in terms of a supported communication channel. 5. The application of claim 1 wherein the one or more contact identities include one or more user identities of other users also using an instance of the software application. 6. The application of claim 3 wherein the zones define user communication parameters for various social environments known to and engaged upon by the user. 7. The application of claim 1 wherein the routing of a communiqué to a particular workspace is managed by contact identity and user identity pairing, the identities applicable to the supported communication channel used in communication. 8. The application of claim 1 wherein the communication channels include email, instant messaging, RSS, and voice channels. 9. The application of claim 8 wherein the voice channels include voice over Internet protocol and voicemail messages. 10. The application of claim 4 wherein a user identity is one of an email address, a telephone number, a machine address, an IP address, or an Enum address particular to the administrator for a particular workspace and communication channel. 11. The application of claim 1 further including user alerts generated according to violations of policy. 12. The application of claim 1 wherein the workspaces include at least one inbox for accepting incoming communiqués. 13. The application of claim 12 further including at least one file folder for holding certain content. 14. The application of claim 13 wherein the certain content includes newsletters received from news groups. 15. The application of claim 13 wherein the certain content includes binary files collected from a news server. 16. The application of claim 1 wherein the communiqués include one or a combination of email messages, voice messages, instant messages, facsimiles, newsletters, chat invitations, instant message invitations, and RSS feeds. 17. The application of claim 1 wherein one or more user identities per workspace are temporary identities created for correspondence and expiring when no longer needed for correspondence. 18. A firewall for directing handling of communiqués of multiple media types transmitted to a single interface over a data-packet-network according to detected identity information associated with corresponding parties involved comprising: a identity analyzer for analyzing and validating the identities detected; and a directory manager for managing validated identities for future reference; characterized in that communiqués received at the interface having a sender and a user identification validated as a recognized identity pair are filed in one or more separate workspaces that support the identities detected and validated. 19. The firewall of claim 18 wherein the data-packet-network is the Internet network. 20. The firewall of claim 18 wherein the one or more workspaces are created zones segregated primarily by genre. 21. The firewall of claim 18 wherein an identity is one of a sender identity or a user identity and an identity pair is indicated by the existence of at least one of each for a communiqué. 22. The firewall of claim 18 further including a content analyzer for searching content and or attachments of a communiqué for information leading to identification and validation of the sender if correct sender identity is not detected by the identity analyzer. 23. The firewall of claim 18 further including policy violation alerts generated if identity paring cannot be accomplished for a communiqué. 24. A method for routing communiqués received at a single interface according to identity information and workspace category comprising steps of: (a) creating one or more workspaces to segregate communication; (b) creating one or more user identities for each created workspace; (c) assigning contact identities to certain ones of the created workspaces authorizing those contacts for communication using the workspace; (d) receiving a communiqué; (e) determining the sender and user identities of the communiqué; and (f) filing the communiqué into the appropriate workspace supporting the detected identities. 25. The method of claim 24 wherein the single interface is a third-party server. 26. The method of claim 24 practiced over the Internet network. 27. The method of claim 24 wherein in step (a) the one or more workspaces are zones administered by a user or a user group. 28. The method of claim 24 wherein in step (a) the one or more workspaces reflect social or business environments known to and engaged upon by the user. 29. The method of claim 24 wherein in step (b) the user identities are related to communication channels by contact information. 30. The method of claim 24 wherein in step (b) some of the user identities are temporary ad hoc identities. 31. The method of claim 24 wherein in step (c) the contact identities relate to contact parameters of appropriate media types. 32. The method of claim 24 wherein in step (c) some contact identities can be applied to more than one workspace. 33. The method of claim 24 wherein in step (a) creating a workspace includes creation of one or more inboxes and one or more additional file folders. 34. The method of claim 24 wherein in step (d) the communiqué is one of an email, an instant message, a voice call, a voice message, a chat request, a facsimile, or a file transfer. 35. The method of claim 24 wherein in step (d) the communiqué is handled by a media handler according to media type. 36. The method of claim 24 wherein in step (d) the communiqué is received by a third party hosting service. 37. The method of claim 24 wherein in step (e) the determination is conducted by an identity analyzer as part of a firewall application. 38. The method of claim 24 wherein in step (e) content analysis is used to help determine the sender identity of the communiqué. 39. The method of claim 24 wherein in step (f) a firewall application orders inbound and outbound routing according to identity pairing, the detected pair comprising the sender identity and the user identity. | FIELD OF THE INVENTION The present invention is in the field of network-based communications including digital transactions and file transfers and pertains particularly to methods and apparatus for managing communications including file transfers and file acquisitions based on user and contact identity information. BACKGROUND OF THE INVENTION With the advent and development of the Internet network, including the World Wide Web and other connected sub-networks; the network interaction experience has been continually enriched over the years and much development continues. In a large part, network users, both veteran and novice have a basic human commonality in that they all share three basic desires that materialize into behavioral traits when engaging in network-enhanced interaction. These behavioral traits are the desire for communication with others, the desire to collect and/or acquire digital content, and the desire to collaborate with others to help solve some problem or to resolve an issue. As behavioral traits, these basic needs can be expanded into many sub-categories. Communication includes interaction over channels such as Instant Messaging (IM), email, posting boards, chat, voice over Internet protocol (VoIP), analog voice, etc. Collection includes collecting art, knowledge, music, photographs, software, news, and so on. Collaboration includes group discussions, task fulfillment, and any other collective efforts to solve a problem or perform a function. In basic form communication, collection, and collaboration are very tightly intertwined as basic desires. As practices many users may unequally engage in the just-mentioned behaviors. For example, virtually all network users have active email accounts and active Instant Messaging capabilities. Most users have IP telephony capabilities and networking collaboration capabilities, at least installed on their computer systems if not actively configured for use. Many users have peer-to-peer file sharing capabilities, often coupled with communication capabilities. General communication may arguably be the most dominant network practice, followed by collection and sharing of content and network collaboration not necessarily in the stated order. To further illustrate the imbalance of the three core behaviors for any one user consider that some users engage heavily in instant messaging, voice and, or email correspondence, while almost never engaging in file transfers or content downloading. Others engage more heavily in collaboration while lightly engaged in file transfer, content download, and common or casual communication. Still others practice content downloading and file sharing more often than collaboration. One can readily attest that it is difficult to practice one behavior exclusively without also practicing the others to some extent. Software providers have long recognized the need to fulfill these basic desires by providing the capabilities in a single interface and have provided many well-known communication applications that provide access to casual and business communication as well as collaboration and file transfer capabilities. Programs like Net-Meeting™ and ICQ™, among many others attempt to aggregate these capabilities into a single accessible interface some times integrating separate communications applications for single point launching. Users generally belong to a variety of communities and organizations that may or may not be tightly structured or organized. For example, a user may have family and friends in their on-line address book along with work associates from the job (two communities that should be separated). The same user may belong to a church group and a golf group, or some other sports group. The same user may also volunteer at a wildlife rehabilitation center. However loosely formed and organized, these separate groups often have a central Web presence, for example, a Web site, posting board, or the like. Likewise many of the group members or associates also have individual on-line capabilities like ISP accounts, email addresses and so on. A user associated with more than one group logically has varying personas or faces that he or she presents to each group. Moreover, the user may logically be willing to share only varying degrees and depth of information with these separate groups largely restricted to the subject matter(s) appropriate to the group. For example, the user's family members and close friends would not share the same type and depth of information as the user's work associates, or the user's wildlife rehab associates. It may be desired by a user, and in fact is logical to conclude that in association with these different groups that group boundaries should be respected with reference to communication channels and formal as well as informal information sharing. A drawback to virtually all of the available communication channels whether they are separate channels or integrated into a communication application, is that a user may have to provide a basic permanent identity and profile for these programs to work successfully. For example, an email account generally requires a permanent email address that the user may have to maintain unless the account is to be abandoned. Using more than one email address generally requires more than one email account for a given user. Likewise instant message applications may require a standard email account and identity. Collaborative tools for business like IP telephone, white boarding, and file transfer services similarly boil down to a single user identity, most likely one he or she uses for most communication channels. Therefore, a user wishing to establish boundaries between different activities associated with different groups in a social architecture generally has a daunting organization task of managing communication methods and channels between different members of different groups as well as manually separating contacts within one or more address books or contact lists. It is extremely likely that many times information that was for one group inadvertently becomes available to another group such as an email address and profile or some file or attachment. Communication channels for each group become blurred and any established boundaries between groups tend to deteriorate over time. One mechanism for enabling users to communicate, collaborate, and collect digital content is the well-known Usenet convention. Usenet is a collection of user-submitted notes or messages about various subjects posted to loosely organized servers known as news servers. News servers can be Internet-hosted or hosted on a sub-network accessible through the Internet. These servers operate according to a network protocol termed network News Transfer Protocol or NNTP. Users of Usenet use software applications known as newsreaders that are adapted to enable a user to subscribe to one or more of many hundreds or even thousands of available news groups for the purpose of reading messages posted by other users and posting messages for others to read. Subject matter available for access in a news server is loosely organized under different topics or subjects, referred to collectively as newsgroups. Therefore, for any given newsgroup, there will be hundreds if not thousands of ongoing interactions loosely organized according to a post/response format threading of message headers, posted messages, and posted replies. In some cases newsgroups are moderated so that the headings and posted messages are somewhat in-line with the topic of the group and unwanted content is edited out. A great many newsgroups are completely un-moderated and anonymous. In these groups a user can post any type of message that he or she desires. Whether or not the posting actually fits the general topic is immaterial. Of course, any conceivable topic may be fodder for a newsgroup. Many companies offer moderated newsgroups that cater to their clients or customers wherein the subject matters for the groups are about their offered products. In these types of groups, users often collaborate with each other to resolve problems or issues. More recently, news servers have become repositories for storing binary content in the form of picture files, movie files, game files and other downloadable content. Collectors often subscribe to specific newsgroups through which content that the user wants to collect is posted. While formerly used more for communication and collaboration, Usenet is now used more and more for collection and sharing of binary files and HTTP links to binary files. As Usenet has evolved over the years, so has the software that enables users to partake in the experience. Although most Web browsers and email clients support Usenet, there are especially dedicated programs that enable more efficient sampling, subscribing and manipulation of content from Usenet. The inventors have developed a particular newsreader known in the market as the Agent reader. The Agent reader allows conventional Usenet practices of newsgroup sampling through header sampling; finding and subscribing to newsgroups; finding and subscribing to free newsgroups; posting of messages to newsgroups after subscribing or to free groups; download of binaries; posting of binaries; integration with point-of-presence (POP) and Simple Message Transfer Protocol (SMTP) email accounts. Agent™ also provides database conventions for managing and archiving retrieved content and a search convention for finding specific content within any particular newsgroup. Evolution of Usenet to a more media-heavy, digital collection environment has also invited more undesirable content encountered in the way of Spam messaging, unwanted pop-ups and the like wherein the content matter of the message or binary has nothing even remotely to do with a particular newsgroup topic. In some cases sampling 50 headers of a group returns mostly junk messages that are not topically aligned to the group subject matter. Still, the popularity of Usenet has increased with many attracted to its relative anonymity and loose organization. Communication, collaboration, and collection behaviors are all possible and practiced currently with reference to many programs already mentioned above including newsreaders, peer-to-peer applications, chat software programs, some email clients, and so on. Many users of these applications become overwhelmed when receiving great numbers of messages, sorting through huge address books for contacts, and trying to regulate and manage contacts and downloaded messages and attached files. Most conventions for sorting and filing messages are manual conventions. In other words a user most often than not has to physically create file folders, if those in a list are not sufficient, and manually select and move messages and other content into them. Another drawback in prior-art is that virtually all available applications for communication, collaboration, and collection focus mainly on content management to protect against Spam messages, undesirable downloads or attachments, and other unwanted messages. Content management is handled through user-configured or regulated filters that sort messages, for example, and eliminate those messages found to fit the filter description. Some applications allow you to block messages sent from certain senders based on the sender's identity through a user-created block list or ignore list. Generally speaking though, users must exert much time, effort, and patience to manually configure one or most often more than one application to manage content. Many businesses use a plurality of identities when sending messages to users through email for example. A particular entity may have several different identities relating to differing departments of service, some of which the user would rather not receive messages from. Because the user has a permanent identity when dealing with other on-line entities, his or her identity information and, in some cases behavioral information gets aggregated and sold to other businesses who then begin spamming the user with emails, instant message pop-ups, even faxes and telephone calls if the information is known to them. As previously described, when messages abound in all groups subscribed to and created by any user, the tasks of managing those messages according to which group, which address book, which contact list, which download folder, and so on becomes rather arduous. Most automated mechanisms for management of messages are task intensive and difficult to understand and configure. Lack of understanding complex management tasks that depend on multiple created rules for success renders a user in a state of constant distraction when the number of rules and tasks become more numerous. A user facing many configuration tasks for content and messaging management for more than one medium is more likely than not to revert to manual threadbare techniques. It has occurred to the inventors that in an interface supporting messaging communication, collaboration, and content collection an architecture focused more on message management through user and sender identities would be a far more efficient tool set than what is currently available in the art. Digital collectors also collaborate and communicate to try and locate specific content and to share content with specific others. In the case of Usenet, content authors may be largely anonymous however they do publish their Usenet identities so that other users can respond to them and communicate or collaborate with them. For the most part digital collection in Usenet and other applications is not organized in the sense that a user gets what he or she downloads. In many cases, especially in Usenet environments, there may or may not be thumbnails to sample for picture files or for movie snippets as part of a series description. Moreover descriptions of content depend on the perception of the poster or author and are more likely than not limited to only a few descriptive words or phrases. Digital collections in Usenet comprise basically postings of a series of binary files, for example, a series of pictures, a movie that may be split-up into a series of short clips, or a software utility or game that is posted as a series of downloads split from the whole by a file splitter and compression application such as WinRAR. In many cases there are re-posts of content that is missing some of its pieces or files. A program known as SmartPAR is sometimes used to provide recovery of missing RAR files of a series. Also, there may be different quality versions of a posted series authored by different Posters. In this case it is desirable to be able to locate the best quality version, or the version that may be compatible with a specific user platform or digital player or viewer. Bandwidth and time spent on-line are also issues to contend with. It would be desirable to be able to locate through identity and enhanced content sampling the best digital content from a particular newsgroup without spending a lot of time and bandwidth downloading. Music finder and picture finder applications are available in most readers, but they simply point out the existence of a jpeg or movie file or series. It would be desirable to be able to sample content by locating rich content description elements that fully describe a series and individual elements of a series. Moreover, applying identity management to the task of searching for content can enable a user to locate content based on similar identity profile information between poster and user. One object of the present invention is to provide a user friendly interface for Usenet and other communication channels that will enable a user to manage multiple identities in a way that a correct identity and, in some cases profile is presented when the user is engaged in an interaction within an environment or specific channel that the user approves of for the use of a particular identity. Another object of the present invention is to provide a mechanism for managing incoming communiqués and user contacts based on identities in a way that automatically organizes and prioritizes incoming messages and contact lists according to user approved environments and communication channels. Yet another object of the present invention is to provide a mechanism for managing workflow tasks in coordination with active identities and user environments. Still another object of the present invention is to provide an enhanced content collection experience wherein binary content can be sampled in a more granular and enriched fashion based on author intent and can reflect style and character that can be disseminated by the collector efficiently before accepting or downloading the content. Therefore, what is clearly needed in the art is an enhanced identity oriented communication, collaboration, and enhanced digital collection platform that will manage content, contacts, and communication-based tasks according to preferred user environments, activities, and identities. A platform such as this will perform management duties in the background while the user can concentrate on immediate communication, collaboration, and collection activities. Such a platform will enrich interaction between users and other network-based entities without compromising user-pertinent information for un-solicited use by certain entities. SUMMARY OF THE INVENTION The inventor provides a software application for managing routing of communiqués across one or more communication channels supported by a data-packet-network. The application includes one or more workspaces for segregating communication activity; one or more unique user identities assigned per workspace; and one or more contact identities assigned to and approved to communicate with a workspace administrator of the one or more workspaces using the assigned user identities. In a preferred embodiment the application enforces a policy implicitly defined by the existing architecture of the workspaces and associated user and contact identities. In one embodiment the supporting data-packet-network is the Internet network and the one or more workspaces are created zones segregated primarily by genre. In this embodiment a user identity relates to a workspace in terms of a supported communication channel. Also in this embodiment the one or more contact identities include one or more user identities of other users also using an instance of the software application. In a preferred embodiment the zones define user communication parameters for various social environments known to and engaged upon by the user. In this embodiment the routing of a communiqué to a particular workspace is managed by contact identity and user identity pairing, the identities applicable to the supported communication channel used in communication. In one embodiment of the invention the communication channels include email, instant messaging, RSS, and voice channels. In this embodiment the voice channels include voice over Internet protocol and voicemail messages. Also in one embodiment a user identity is one of an email address, a telephone number, a machine address, an IP address, or an Enum address particular to the administrator for a particular workspace and communication channel. In one embodiment of the invention the application may include user alerts generated according to violations of policy. In a preferred embodiment workspaces include at least one inbox for accepting incoming communiqués. In this embodiment workspaces may also include at least one file folder for holding certain content. The certain content may include newsletters received from news groups. In another embodiment content may include binary files collected from a news server. In a preferred embodiment of the invention the communiqués include one or a combination of email messages, voice messages, instant messages, facsimiles, newsletters, chat invitations, instant message invitations, and RSS feeds. In one embodiment one or more user identities per workspace are temporary identities created for correspondence and expiring when no longer needed for correspondence. According to another embodiment of the present invention a firewall is provided for directing handling of communiqués of multiple media types transmitted to a single interface over a data-packet-network according to detected identity information associated with corresponding parties involved. The firewall may include an identity analyzer for analyzing and validating the identities detected; and a directory manager for managing validated identities for future reference. In this embodiment communiqués received at the interface having a sender and a user identification validated as a recognized identity pair are filed in one or more separate workspaces that support the identities detected and validated. In a preferred embodiment the data-packet-network is the Internet network and the one or more workspaces are created zones segregated primarily by genre. In this embodiment an identity is one of a sender identity or a user identity and an identity pair is indicated by the existence of at least one of each for a communiqué. In one embodiment of the present invention the firewall includes a content analyzer for searching content and or attachments of a communiqué for information leading to identification and validation of the sender if the identity analyzer does not detect correct sender identity. In one embodiment the firewall further includes policy violation alerts, which are generated if identity paring cannot be accomplished for a communiqué. According to yet another embodiment of the present invention a method for routing communiqués received at a single interface according to identity information and workspace category is provided including steps (a) creating one or more workspaces to segregate communication; (b) creating one or more user identities for each created workspace; (c) assigning contact identities to certain ones of the created workspaces authorizing those contacts for communication using the workspace; (d) receiving a communiqué; (e) determining the sender and user identities of the communiqué; and (f) filing the communiqué into the appropriate workspace supporting the detected identities. According to one embodiment the single interface is a third-party server. In a preferred embodiment the methods are practiced over the Internet network. In another embodiment with respect to (a) the one or more workspaces are zones administered by a user or a user group. In this embodiment the zones may reflect social or business environments known to and engaged upon by the user. In a preferred embodiment with respect to (b) the user identities are related to communication channels by contact information. In a variation of this embodiment some of the user identities are temporary ad hoc identities. In a preferred embodiment with respect to (c) the contact identities relate to contact parameters of appropriate media types. In this embodiment some contact identities can be applied to more than one workspace. Also in a preferred embodiment with respect to (a) creating a workspace includes creation of one or more inboxes and one or more additional file folders. Also in this embodiment with respect to (d) the communiqué is one of an email, an instant message, a voice call, a voice message, a chat request, a facsimile, or a file transfer. In one embodiment with respect to (d) the communiqué is handled by a media handler according to media type. In still another embodiment a third party hosting service receives the communiqué. In a preferred application with respect to (e) the determination is conducted by an identity analyzer as part of a firewall application. In a variant of this application content analysis is used to help determine the sender identity of the communiqué. Also in this preferred application with respect to (f) a firewall application orders inbound and outbound routing according to identity pairing, the detected pair comprising the sender identity and the user identity. BRIEF DESCRIPTION OF THE DRAWING FIGURES FIG. 1 is an architectural overview of a communications network for practicing identity and zone-managed communication and digital collection according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating software applications and system components of an Agent software suite according to an embodiment of the present invention. FIG. 3 is an entity relationship diagram illustrating structure of a zone according to an embodiment of the present invention. FIG. 4 is an architectural view of a user interacting with Web-based zone creation services according to an embodiment of the present invention. FIG. 5 is a block diagram illustrating interaction paths between an IOM client and network peers and services according to an embodiment of the present invention FIG. 6 is an architectural overview illustrating an example of replication of messages according to an embodiment of the present invention. FIG. 7 is a block diagram illustrating architecture of a personal zone according to one embodiment of the present invention. FIG. 8 is a block diagram illustrating a hosted email account firewall application according to an embodiment of the present invention. FIG. 9 is a block diagram 900 illustrating components and function of an identity oriented firewall application 119 according to an embodiment of the present invention. FIG. 10 is a block diagram illustrating firewall alert features according to an embodiment of the present invention. FIG. 11 is an architectural overview of a Web-based service adapted for third-party zone hosting according to an embodiment of the present invention. FIG. 12 is a block diagram illustrating software layers and components according to one embodiment of the present invention. FIG. 13 is a block diagram illustrating portal interface functionality according to an embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a preferred embodiment of the present invention, a software suite is provided for managing network communication and digital collection activities according to user and contact identities. The methods and apparatus of the present invention are described in enabling detail below. FIG. 1 is an architectural overview of a communications network 100 for practicing identity and zone-managed communication and digital collection according to an embodiment of the present invention. Communications network 100 encompasses a data-packet-network (DPN) 101 and accessing users a-h. DPN 101 is the well-known Internet network in a preferred example, which includes any sub-networks that might be connected thereto such as an Ethernet network, an Intranet network, or any other compatible data networks. The inventor chooses the Internet as a preferred example because of a characteristic of unlimited public accessibility. Users a-h are illustrated in this example as an array of desktop computer icons representing computer stations capable of Internet access and interaction. One with skill in the art will appreciate that there are a variety of computer station types known as well as a variety of Internet-access methods known. For exemplary purposes users a-h are shown connected to Internet network 101 through a public-switched-telephony-network (PSTN) represented herein by telephony connectivity network (114,121), which provides access through an illustrated telephony switch 113 to an Internet service provider (ISP) 102. Telephony switch 113 is a local switch (LS) local to particular user group a-h. In this example, the Internet connection method is simple dial-up services through an ISP as is common in the art. Other Internet access conventions such as cable/modem, digital subscriber line (DSL), integrated services digital network (ISDN), and more recently developed wireless conventions can also be used. ISP 102 connects to an Internet pipeline or backbone 104, which represents all of the lines, connection points, and equipment that make up the Internet network as a whole. Therefore, taken into account the known ranges of the Internet and PSTN network, there are no geographic limits to the practice of the present invention. A gateway 122 is illustrated in this example and represents a gateway between Internet 101 and PSTN (114, 121) such as the well-known Bell core standard of SS7, for bi-directional transformation of telephony signaling and data-packet-streams for communication over the respective networks. Gateway 122 may also be a wireless application gateway into network 101 without departing from the spirit and scope of the present invention. Gateway 122 is connected to backbone 104 by an Internet line 124. Internet 101 represented in breadth by backbone 104 has a plurality of electronic data servers illustrated therein and adapted individually to provide some form of communication services or other network services. A Lightweight Directory Access Protocol (LDAP) server is illustrated as connected to backbone 104 and adapted to provide access to users analogous to users a-h to directory services. LDAP is a software protocol that enables any user to locate any other user, organization, resources file, or network connected device. In this example, LDAP server 106 may play a roll in providing access to loose social groups whose members use identity-oriented routing of messaging and zone management for communication and collaboration with each other and fringe associates that may not have client software used by group members as will be described in more detail later in this specification. An instant message server 107 is illustrated within Internet 101 and connected to backbone 104 for communication. IM messaging is an asynchronous form of communication comprising routed messages. A goal of the present invention is to enable routing of IM messages according to identities and zones. IM server 107 represents any of the widely available and known instant message services like AOL™, Microsoft™, ICQ™, and others including those that leverage presence protocols. A network news transport protocol (NNTP) server 108 is illustrated within Internet 101 and connected to backbone 104 for access. NNTP is the predominant protocol used by software clients like Agent and servers for managing notes and files posted to Usenet groups. NNTP protocol replaced the original Usenet protocol Unix-to-Unix-Copy Protocol (UUCP). NNTP servers manage the global network of collected Usenet newsgroups and include servers that provide Internet access. An NNTP client is included as part of a Web browser or, in the case of this example, a separate client program called a newsreader described further below. An NNTP sever is accessed for the purpose of browsing messages, posting messages, and for downloading messages and files. As described further above with reference to the background section of this specification, NNTP servers also can be dedicated to storing binaries (music, movies, pictures, games, etc.), available for downloading and allowing Usenet patrons to post binaries to the server. A goal of the present invention is to provide routing of Usenet messages and binaries according to identities and zones as described further above. As described further above with reference to the background section of this specification, the inventor is aware of and has developed the newsreader application known as Agent. The present invention relates to novel enhancements to the prior-art version of the application, the enhancements enabling identity oriented routing and message management according to created zones. A voice server 109 is illustrated within Internet 101 and connected to backbone 104 for access. Voice server 109 is analogous to a Voice over Internet Protocol (VoIP) server capable of storing and forwarding voice messages or of conducting real-time voice session between two or more parties connected to the network including connection from a remote analog network via telephony gateway. Although methods of the present invention deal largely with asynchronous communication, one goal of the present invention is to enable network-hosted interaction services that use identities of sender and receiver in the concept of created identities that are zone specific to route live voice interactions sourced from either network 101 or PSTN 114,121. Voice server 109 may also be assumed to represent an analog counterpart held within the PSTN network in terms of functionality. An email server 110 is illustrated within Internet 101 and connected to backbone 104 for access. Server 110 represents a typical email server having a port for post office protocol (POP), a port for simple message transport protocol (SMTP), and a port for Internet mail access protocol (IMAP), which is a Web-based service that allows users access to email from any browser interface. A goal of the present invention is to enable routing of emails according to created identities and zones managed by a unique firewall application described further below. A peer-to-peer server (P2P) 111 is illustrated within network 101 and connected to backbone 104 for access. P2P server 111 is analogous to any source or relay server of digital music, movie, or picture files that can be downloaded there from by users. Server 111 can be a proxy server that accesses individual desktop computers to retrieve content from a “shared folder” adapted for the purpose, as is the general practice of well-known music download services. A really simple syndicate (RSS) server 112 is illustrated within Internet 101 and connected to backbone 104 for network access. RSS is a format for syndicating news and the content of news-like sites, including major news sites like Wired™, news-oriented community sites like Slashdot™, and personal Weblogs. An RSS server can handle other formats besides news formats. Any topic that can be broken down into discrete items can be syndicated using RSS, for example, the history of a book. When a subject matter is presented in RSS format it is delivered as an RSS feed to an RSS-enhanced reader, which can periodically check or monitor the feed for any changes and react to the changes in an appropriate way. An RSS enhanced reader can be thought of as a news aggregator that alerts the user to any new items in the RSS feeds. It is a goal of the present invention to enable identity oriented routing of RSS feeds using created identities and managed zones. It will be apparent to one with skill in the art that the plurality of servers illustrated in this example represent differing types and forms of communication and interaction including “digital collection” interaction. One goal of the present invention is to enable fast sampling of digital postings of binaries and downloaded collections thereof in a more efficient and identity oriented manner, including routing downloads of such materials into appropriate user zones based on identity and content-related information. Users a-h may be assumed to be operating an Agent software suite 120 shown in display on user computer c in this example. It may be assumed that all users a-h have SW 120 resident on their workstations or at least a portion of suite 120 operational and locally executable. SW 120 is expanded in illustration from display on station c to reveal several application components. These are a reader application 115, a posting application 116, a collector application 117, a zone manager application 118, and an identity/zone firewall application 119. As a software suite (120), applications 115-119 may be provided having various levels of integration and standalone functionality without departing from the spirit and scope of the present invention. The inventor illustrates the functional portions or applications of suite 120 separately for the purposes of describing separate functions and capabilities and in actual practice some of applications 115-119 may be provided as standalone applications that can be installed separately from each other the whole of which when installed work together as a functional and integrated application suite. Reader application 115 encompasses functionality for accessing and browsing news servers like NNTP server 108 for sampling and subscribing to news groups and message boards. In this example, reader 115 is enhanced (RSS plug-in) for navigation to an RSS server like RSS server 112 for the purpose of sampling and subscribing to news feeds and other informational feeds. Reader 115 may be assumed to contain all of the former functionality of the Agent newsreader described with reference to the background section and which is available to the inventor. Reader 115, for example, allows a user to read and download messages and to monitor message threads of certain users that have posted to a server. Reader 115 can also monitor news feeds and alert a user when new feed content is available. Reader 115 may be assumed to include a graphical user interface (GUI not illustrated) that includes capabilities of navigation to different online news servers and other typical browser functions. Reader 115, in preferred embodiment, has interactive GUI linking capability to and is, in various capacities, integrated with posting application 116, collector application 117, zone manager 118, and firewall application 119. In one embodiment, a single main GUI is provided that interlinks access to the functions provided by all of applications 115-119. In this embodiment a partial suite 120 not including all of applications 115-119 would have GUI icons that represent the missing components, however such icons might be “grayed out” or otherwise caused to indicate that one or more applications of suite 120 is not installed. In a preferred embodiment application 119 is provided as a default component of suite 120 because it provides the basis for identity-oriented routing of messages and interactions. In another embodiment, separate GUIs are provided as standalone GUIs for each functional application wherein appropriate GUI links are provided for navigation from one interface (functional application control) to another. There are many possible design possibilities. Posting application 116 encompasses the capability to post (upload) messages and binaries to NNTP servers and posting boards. Poster 116 has an interface, not illustrated, for creation and upload of created postings, which include text-based postings and binary postings. Poster 116 is RSS-enhanced as was described with reference to reader application 115. In this way a posting user can create news and informational feeds upload them to RSS server 112, for example, for other users to download. Collector application 117 enables digital sampling and collection of binaries from NNTP sever 108 and in some configured cases from P2P (server 111). Collector application 117 enables identity-oriented tracking and sampling of posted materials. Collector 117 is provided as a dedicated application, in a preferred embodiment, however it may also be integrated with reader 115 and poster 116 without departing from the spirit and scope of the present invention. In one embodiment collector 117 may be integrated with other applications as well such as a music jukebox application, media server applications, content management applications, and streaming content applications. Zone manager 118 is a utility for enabling a user to create special identity-oriented (IO) workspace zones (not illustrated) that may have one or more associated identities. By default, a certain generic set of IO zones might be provided with suite 120, however a user may create as many IO zones as is required to comfortably manage messaging according to identity. The policies of IO zones are enforced by firewall application 119. The concepts of IO zones will be detailed later in this specification. Firewall application 119 is a utility for enforcing IO-routing of messaging and interaction according to policy related to active zones. Firewall 119 provides a single security and message routing solution that can be used to handle incoming and outgoing email, IM interactions, and interaction associated with other media channels including voice channels using multiple identities and of various accounts. In practice of the present invention, suite 120 enhances prior-art functionality associated with standalone newsreaders, messaging clients, and digital collecting utilities by first providing a single or series of linked interfaces through which all of the activities can be accomplished and secondly by providing new and novel capabilities of managing interactions and work-related tasks according to one or a combination of user and sender identities, including contact identities. IO zones are firewall-protected (firewall 119) containers of content and workspace having a specified and implicit relationship to the overall activity and workflow generated by suite 120. Several advantages of identity-oriented zone-management capabilities will be described according to various exemplary embodiments detailed later in this specification. FIG. 2 is a block diagram illustrating software applications and system components of an Agent software suite according to an embodiment of the present invention. Agent software applications include Agent Reader application 115, Agent Poster application 116, and Agent Collector application 117 as described with reference to FIG. 1 above. Firewall 119 is illustrated as a block 119 to preserve hierarchy in description and also in expanded form (119) to show supported routing function and supported communications channels. Firewall 119 is in a preferred example, a resident and self-configurable part of Agent suite 120 and is minimally adapted to direct final destination routing of incoming messages and to provide zone and identity policy violation alerts to users when user or external contact behavior might trigger such alerts. Agent Reader application 115 includes a plug-in for disseminating RSS feeds as previously described. Reader 115 is adapted to enable a user to subscribe to NNTP news groups and to collaborate using messaging and posting in conjunction with Agent Poster 116. In a preferred embodiment of the present invention, a user has identity oriented zones (200), which are segregated from one another and may include separate identities associated thereto each separate identity belonging to the same user and administrator of the zones. In this example, reader 115 lists the exemplary user zones 200 reading from top to bottom within block 115 as a personal zone, a work zone, a business zone, a political zone, and an after hours zone. Each zone is adapted for material segregation and messaging according to the differing identities of the user enforced by firewall application 119. For example, the personal zone would be used in routing all of the user's correspondence messages and subscribed-to materials that are of a personal nature or considered personal such as messages to and from personal friends, family members, and trusted individuals. A personal zone has at least one user identity (contact parameter) that the user is willing to share with personal friends, family, and other trusted individuals. A work zone is adapted for correspondence and collaboration between the user and those associates related to the user's employment. The user identity associated with his or her work zone may be shared only with those individuals associated with the employment environment of the user. All correspondence associated with the work environment of the user is routed to and from the work zone. A business zone is exemplary of a zone adapted with a user's business identity. Perhaps a user has a separate business he or she is conducting separately from work. All correspondence then that relates to the user's business is routed to and from this zone. The identity (contact information identifying the user) associated with the business zone is the identity that the user leverages in correspondence to all those related to the business. A political zone contains the user's political identity and segregates the user's political correspondence and activities from other zones. Political fund-raising activities, campaign work, political correspondence, letter writing, and so on is contained within the political zone. An after hours zone contains the user's after hours identity that he or she is willing to share with related organizations, Web-sites, and so on. The user may be single and belong to one or more dating services. The after hours identity then would be used to correspond with other singles of the same service for example. The user's after hours identity is separate from all other zone-specific identities and no one has this identity of the user except those authorized to correspond with the user along any subject falling within the after hours zone policy. It will be apparent to one with skill in the art that the zones listed and associated with Agent Reader 115 are exemplary and may be of different titles and number than are illustrated in this embodiment without departing from the spirit and scope of the present invention. It is also noted herein that different activities enabled by different portions of the Agent suite may be associated with different zones as evidenced by the listing of only some of zones 200 within block 115. Different portions of the Agent suite may also utilize the same zones without departing from the spirit and scope of the present invention. In one embodiment of the present invention, certain generic zones common to most users like personal zone and work zone for example are pre-configured and provided for a user. A user may configure new zones and identities as needed or desired. When an existing zone encompasses subject matter that begins to vary within the context of the zone, a user may split the zone into two new zones having separate identities if desired. There are many possibilities. Agent poster 116 is used to post information (messages and binaries) to Usenet groups, posting boards, and other supported venues. Reader 115 and Poster 116 are in a preferred embodiment integrated and accessible through a common interface. However, poster 116 may also be provided with its own interface as a standalone application packaged separately without departing from the spirit and scope of the present invention. The active or configured zones 200 listed within Agent Poster 116 include, but are not limited to a music zone, a literature zone, a travel zone, a sports zone, and a family zone. It is noted again here that the actual zones used may be entirely different than the one listed in this example. The inventor provides certain zone description in this example for discussion purposes only. A music zone is associated with a user's music identity and may govern all of the user's posting activities with music services, and music binary servers such as may be subscribed to by the user through Usenet or a similar platform. For example, a user's binary collection of MP3 files might be accessible for posting through the music zone interface. A literature zone is associated with a user's literature interests and might govern a collection of pieces of literature that a user will post to a certain newsgroup for download by others. The zones travel, sports, and family govern materials appropriately associated therewith. For example, the travel zone would contain information about the user's travels, vacation information, and so on. Using poster 116, the user may post information to others related to travel opportunities or experience the user has had. Perhaps a user might post some e-tickets to a certain destination for others to view and perhaps purchase or download. A user might post e-tickets to a basketball game through the sports zone. The same user might post homemade movie files and picture albums through his or her family zone. All correspondence with the user related to such activity is conducted to and from the identity appropriate zone. It is noted herein that along with segregated user identities attributed to each user zone, zones also have separate contact identity lists identifying those entities that have firewall access to the user through a particular zone and which are allowed to have and know the zone specific identity. All of the activity conducted in zone specificity is managed by firewall 119. Agent collector 117 is used to find and download binaries posted on Usenet binary servers using NNTP protocols, or other supported Web-storage servers like FTP servers. In the case of FTP (file transfer protocol) sites, both the poster and collector application would be adapted to work with FTP protocols. It is noted that the same zones listed in Agent Poster 116 are also listed in Agent Collector 117. These represent zones that support binary collections in terms of collecting, posting, and viewing. It is noted herein that poster 116 and collector 117 may be integrated using one common interface without departing from the spirit and scope of the present invention. It is also noted herein that collection of binaries can be practiced in conjunction with use of reader 115 without departing from the spirit and scope of the present invention. Furthermore, the zones listed in reader 115 may also govern posting and collection activities conducted under the identities associated with the appropriate zones. For example, if a user subscribes to a newsgroup server that aids his or her employment and that server allows posting and download of binaries, then the work zone would also be visible or at least accessible from poster 116 and collector 117. Agent Collector 117, like Agent Poster 116 might also be provided as a separate and standalone plug-in to the overall Agent suite. Identity/Zone firewall 119 provides zone and identity policy enforcement through implicit adherence to the most current zone configuration and identity states. Application 119 may be thought of as a final destination router for incoming messages, interactions and downloads. Similarly, application 119 controls outgoing correspondence insuring that zone and identity policies are not inadvertently violated. Firewall 119 enforces routing of all incoming and outgoing messages according to zone policy. Firewall 119 may be configured for any or all zones and for any or all identities. For example if a user attempted to email a contact listed in a specific zone while working in a zone where the contact is not supported then firewall 119 would generate an alert describing a zone policy violation and display it for the user before sending of the message would be allowed. Application 119 directs final destination routing or sorting of all incoming messages and materials according to current zone policy. This may include structured Web-browsing in a zone specific manner. In a simple example of messaging, email directed to specific user identities would be filtered according to appropriate zone inboxes. Other interaction types including RSS, IM, NTTP, Voice, P2P, and Chat may be supported for final destination routing according to zone policy in different ways appropriate to the communication channels supported. In one example an instant message addressed to a zone-specific user identity causes firewall application 119 to dress the IM interface with an icon or skin that identifies the appropriate zone that the message relates to. If the user is currently messaging with another contact related to another zone then a new IM window reflecting the zone of the new message may pop-up. Similarly, if a user attempts to IM a contact supported by a specific zone using a generic IM interface, then firewall 119 might change the interface to reflect the appropriate zone that supports the contact. If more than one zone supports the contact then firewall 119 might display a message to the user stating that the contact is common to, for example, your work zone and your sports zone. The user may then select the appropriate zone for the communication. Zone/ID manager 118 described with reference to FIG. 1 above enables configuration of the physical zones and provides update and identity creation services. Zone/ID manager 118 has a user interface or configuration form (not illustrated) that supports zone and identity creation. The exact configuration of a set of zones and associated identities provides implicit rules for firewall application 119 to use in enforcement of zone policy. Additionally, zone manager 118 allows for creation of explicit rules that firewall application 119 can use. An explicit rule can be a permanent rule or a temporary rule and can include a zone, an identity, and a communication channel alone or in combination. A message replication module 202 is provided and adapted for the purpose of replicating incoming messages to multiple pre-assigned zone inboxes if applicable. In one example using message replication, a user might replicate an incoming email message specific to a user zone to other zones of the user account or other user accounts held on one computer or computer network for example. In this case the user might be an administrator of more than one identity oriented managed account. Zone manager 118 and message replication module 202 as well as IO firewall 119 may be, in one embodiment, provided as proxy Web-based services that enable interaction routing and Web-based workflow management for users accessing and, in some cases interacting in real time with the system through a Web-based portal. In another embodiment, a user may configure and manage zones and identities locally with minimal or no Web-based service support. A Web-based example of identity-oriented-management (IOM) services is described in detail further below. Firewall 119 as described above is provided and adapted to provide security services for each zone and associated identities and contacts according to zone policy so that no zone cross routing or cross-communication is allowed if it is not desired. Firewall 119 uses zone, identity and contact configuration as implicit policy for managing communication related to each separate zone. In this way an incoming message that should be routed to a user's work zone for example is not routed to any other zone inbox. Communication activity is governed chiefly by identity/contact pair (sender and receiver identities) enforced by firewall 119. A specific contact listed for a zone-enabled user might exist and may have the same parameters listed for more than one user zone if the contact has only one identity (email address for example). However the destination address (user's zone-specific identity) the contact chooses for email correspondence is preferably specific to only one user zone. For example if a co-worker [email protected] sends an e-mail to a zone-specific identity [email protected] and [email protected] is associated only with a work zone, then that message would be routed to the associated work zone inbox. Identities are generated for zone management purposes. However, it is possible that John only has one contact identity and in addition to being a co-worker also is a trusted family friend that has knowledge of a user identity specific to the family zone, perhaps [email protected]. If John uses family.net as the destination address in the To: line of the email message then the email message is automatically routed to the family inbox instead of the work inbox according to identity. In the above-described routing example, John could inadvertently send a work-related mail to the family inbox if he types or inserts the family identity into the destination address by mistake instead of the work identity if he is privy to both identities. However, the fact that the identity visibly suggests to John that this is a family-related identity might alert him of the mistake before send. In actual practice, John will most likely have a work and a home email address even if he does not use the system of the invention. The contact information for John can be strictly managed so that the work zone does not support John's home email address and the family zone does not support John's work email address. More simply stated, if John mistakenly sends a message to the family identity from work firewall 119 will catch the mistake and alert the user of an incompatible identity-contact pair. In one embodiment an appropriate media handler adapted for a specific message of type can parse subject lines and content of an email message, for example, for an indication of zone specificity. It might be that John has only one identity that is shared as a same contact parameter across more than one user zone. In this case if John's subject line reads, “project management report” for example, but the destination address of the message is the family zone identity, firewall 119 will designate the work zone as the appropriate destination instead of the family zone according to subject line interpretation. In this case it is assumed that a list of keywords and phrases would be provided that are zone specific for parsing to work successfully. If the subject line is blank or otherwise not recognized, firewall 119 may intervene with a user alert to manually select which of the zones listing [email protected] the message from John should be routed to. It is noted herein that if John of the above example is operating from an interface of the present invention to collaborate with Frank, then John will likely have separate identities for his own work zone and family zone, the identities listed as contacts in Frank's respective work and family zones. In this case, zone-to-zone collaboration is performed seamlessly with no errors due to synchronization of identity/contact parameters. More detail and specific examples of message routing according to identity/contact pair will be provided later in this specification. All zones of a user may be configured on the user's desktop and some or all of them can be replicated at a network portal if the user has subscribed to network hosted services. Such services may be offered through zone host 103 described with reference to FIG. 1 above. Exemplary zone list 200 is illustrated in this example and includes the zone descriptions work, community, business, family, literature, travel, personal, sports, music, after hours, political, and pet. Zones 200 are exemplary only as any one user may have fewer or more zones. List 200 simply exemplifies the possibilities of different zone types that might be created. It is also noted that not all of the existing zones in this example are necessarily configured for posting and collecting activities. However, it may be assumed that all created zones support at least messaging and news group association. In this particular case, the user may have 12 different identities, one for each illustrated zone. FIG. 3 is an entity relationship diagram 300 illustrating structure and function of a zone according to one embodiment of the present invention. Zone structure 300 illustrates the existence of certain zone objects and their relationships in a zone object hierarchy. A first zone or Zone 1 is illustrated herein with an indication that the zone is hosted (IsHosted). This means that the zone in question including all associated objects thereof is managed by proxy by a network-based service that keeps track of message routing and replicates activity to desktop systems when user's log in to access the system. In one embodiment, zone 1 might not be network hosted. Zone 1 has a Directory, which is adapted to list one or more Contact(s) that are approved for that particular zone. Contact can be of Type person or entity. Directory may also list one or more Group(s), which may be of Type List or Company. List or Company implies a generic contact parameter that is associated with more than one possible final destination. For example, a Group might be labeled Machine World and might be of Identity Business, which has an Address of Type [email protected] and a message sent there might be routed to one of a number of possible sales agents. Contact has an Identity that can be of type home, work, etc. A contact Jim might include Jim's work identity=“Jim at work” or his home identity=“Jim at home”. Jim might also have an Identity=Jim mobile (not at work or home). Identity has an Address, which can be of Type email, telephone number, IM address, etc. For one zone it is typical that a contact specific to that zone would have one identity and only one of each supported address per supported communication channel. For example if zone 1 is a family zone then Contact=person, Identity=home, and Address=email and telephone number would be a logical configuration. The email address and telephone number identifies the channels and destination parameters used to reach Contact at Home. Zone 1 has a User Identity, which may be of Type home, work, etc. Like a contact, User Identity has an Address of Type email, telephone, IM, etc. User Identity might=Frank at Home and have an Address of Type [email protected] and a home telephone number, and an IM [email protected]. User Identity identifies the zone owner or administrator. A user identity is specific to a zone and identifies the owner of the zone in a manner specific to the zone adaptation. For example an identity can be a home identity, a work identity, an after hours identity and so on. If the identity is a work identity then the zone it is associated to will be a work zone. A user identity has an address where mail is routed (email) and may also include a telephone number, an IM address, and other communications address information if desired. For example a user identity for a work zone will include a work telephone number whereas a user identity for a home zone will include the home telephone number. That is to say if telephone contact information is included. A directory may, in one embodiment, physically include the zone identity (user identity for zone) along with listed contacts but may be segregated and not explicitly identified as a contact but as the identity of the user for that zone. In this example, User Identity is not illustrated as included within Directory but is a separate attribute of Zone 1. A user identity might also be expressed as a “Group” identity although the possibility is not illustrated in this diagram. A group identity might include a number of separate users all having administrative access at one time or another to the same zone wherein the sum of users are expressed as a single group identity=Maple Church, for example, wherein a list of church zone-authorized members might be aggregated together under an Address or Type [email protected]. There are many configurable possibilities. The case of group user identity implies administrative equivalence among the listed individuals sharing the zone. Zone 1 has at least one Inbox, which may include an email box, a voice mail box, a box holding subscribed-to mailings from a list server, a box for newsletters or notices from subscribed-to news groups, RSS Feed, etc. Inboxes are flexible according to supported channel. For example, an inbox might be provided to take incoming communication or materials coming in over any supported communication channel. In one embodiment there will be a single inbox set up for each supported communication form. For example an email inbox specific to the email address of the user identity is provided to contain incoming emails sent to the particular email address specifying the user identity of the zone. For example, all mail incoming to [email protected] goes into the email inbox of that zone. An inbox may include an interaction logging function, for example, to record message or call details of incoming and outgoing activity for accounting purposes and the like. In one embodiment only a single inbox is provided within a zone and adapted to accept all supported communications addressed to the user identity for that zone. For example, if a user has a private telephone number that is specific to the zone and published to approved contacts, then all calls to that telephone number wherein the sender identity of the caller matches one in the zones contact directory will be routed to the zone message inbox as voice messages. Inbox may contain one or more Message(s), which can be email messages, newsletters, Internet postings, Instant messages, etc. Likewise any message can be part of a message thread such as an ongoing email correspondence. In one embodiment Identity, an attribute of Contact may have a Contact History of kept messages that can be reviewed as a thread. In this case messages that are part of correspondence with a certain contact can be sorted serially or by other methods and isolated as correspondence records attributed to that contact. Message(s) can be sorted to one or more Folder(s) setup within an inbox for sorting messages appropriately according to folder type such as “message threads”, “newsletters”, “chat transcripts” and so one. In this case a user may click on an appropriate folder to view any new messages that have been filed since the last inbox access. Folders may also include a Spam folder, or a folder for unsorted messages. Message(s) is linked to Collection, which is an activity attribute of a Collection Module that includes a Binary attribute. Binary files, which may be audio files, video files, picture (Jpeg) files and so on may be sampled and collected (downloaded) through inbox architecture. Collection includes sampling available files that are marked or tagged with a digital collection markup language (DCML), which is a convention provided by the inventor to enable more structure in sampling and tracking digital content that may be posted for example, in a binary server. When posting material with an application adapted for the purpose, a poster may use DCML tags to summarize and identify posted materials. A user looking for posted materials has use of a DCML reader that can find and interpret DCML tags. In this way a user can more effectively and efficiently obtain materials from servers and from P2P networks. In this case a binary server for zone 1 might be a listed contact (entity) and might have an identity of “collection”. It is noted herein that Folder is also an attribute that is applicable to Binary and Collection where digital content may be sorted and kept in specified folders accessible through inbox architecture. Zone 1 is associated in this example to a second Zone 2 at the level of directory. In one embodiment a directory might be shared between two separate zones as illustrated by a dotted rectangle labeled Shared Directory. The attribute Contact of Zone 1 is linked to Contact of Zone 2. This indicates that certain contacts of Zone 1 are also approved and available from the directory of Zone 2 while working from Zone 2. In this sense, both directories share one or more common contacts. The level of contact linking across two or more zones is a matter of design and sharing can be configured such that the shared contacts may be the same only in abstract identity but may exhibit differing attributes with respect to actual contact parameters. As described further above, the concept of hosted zones as illustrated in ER diagram 300 relates to a unique service for routing and managing zone specific interaction wherein zone owners have unique identities that the outside world sees and wherein contacts approved to interact within a user zone are the only entities capable of interaction with the user in a particular zone. In a hosted embodiment, the user subscribes to a portal service that provides routing services that are identity and zone specific as described further above. In this regard a portal page is provided for the user to check and view zone activity from any network-capable device. In a hosted embodiment a user may synchronize with the Web-service updating zone structure and content between a local computer and the server hosting the zones. The zone-hosting service is especially useful for a person or a group of persons having many zones and identities to manage. A person having only two zones for example may not require host services. If more thin one user or a user group shares a zone then zone hosting may be more likely. Identity oriented management then may encompass all interactions between a zone owner (zone ID) and outside entities in a secure manner such that no disapproved contacts become privy to zone identities and similarly wherein no created user identities are provided inadvertently to disapproved contacts. In one embodiment a user may elect that no zones are hosted and may manage all of his or her zone-specific communication and archiving on his or her own computer. In either case of hosted or non-hosted zones, the structure is essentially the same and zone policy is enforced in both cases by a zone firewall (119, FIGS. 1 and 2) that will be described in yet more detail later in this specification. It will be apparent to one with skill in the art that ER diagram 300 may include more or fewer attributes and may be extended to provide additional component types and different associations between components without departing from the spirit and scope of the present invention. In one embodiment of the present invention, a user may have an IP telephony application configured to be accessible from the well-known PSTN network through normal telephone dialing for example. In this case a telephone number may be mapped to an IP application and specified to a particular zone so that live voice sessions may be conducted in a zone-specific manner. Any incoming calls that do not include information of the caller that matches a contact in the zone directory would be automatically rejected or sent directly to voice mail as a zone policy violation by firewall 119. Instant messaging and other application-based sessions like P2P file sharing can be conducted as well in a zone-specific manner. Outbound campaigns specific to media types such as voice or email may also be conducted in an identity oriented manner. In one embodiment, the message attribute of Inbox can identify an interaction thread (chain of correspondence) with one or more contacts having access to the zone identity for communication. Such interactions can include, but are not limited to voice messages or transcripts, email correspondence chains, chat transcripts, message board or Usenet postings and reply threads specific to contact/user identity pairs, and so on. These correspondence histories or threads may be stored as separate interactions in one or more folders adapted to contain them. Folders can be identified in any number of ways. For example, in a pet zone there may be a folder labeled after a news group topic alt.showdogs wherein the messaging history is recorded as an ongoing interaction between the user identity and one or more approved contacts participating in the group. In this sense, all of the related communiqués posted by the specified contacts (newsgroup members) listed in the zone directory would be automatically downloaded and stored in the folder as an ongoing interaction. Further, the system can alert users by any one of various communication protocols of any new updates to interaction threads maintained in any of various sub-folders that might be created. As previously described, folders may be provided to segregate materials that are received in a zone inbox or inboxes. Folders are shortcuts to data and can be navigated in typical OS fashion wherein opening of a folder reveals the files contained therein. Each inbox may have one or more folders associated with it. A Zone and its navigable components including Inbox, Message, Binary, Collection, and Folder typically reference folders that are visible to an operating system of a host computing device as a navigable tree of files and folders. It is noted herein that interaction may also involve downloading, posting, or even sharing binaries (via P2P, NNTP, email or IM) that belong to a user's binary collection. For example, if the zone is a music zone and there are contacts in the contact directory that are authorized for content sharing, then binaries that are posted by those contacts can be detected and downloaded to the appropriate zone specific inbox. In one embodiment a zone can support P2P contacts that can be listed in a zone directory and can be given access to a zone interaction folder for the purpose of uploading content there from or depositing content thereto using an application similar to a file sharing application or an FTP application. In traditional P2P networks there is a proxy server that accesses a user's computer on behalf of another requesting user that is looking for a specific file to download such as a music file. In this case, the service might be network hosted by the zone host described with reference to FIG. 1 above and members may be prevented from accessing a file unless they are added to a zone directory list of authorized content sharers. FIG. 4 is an architectural view 400 of a user interacting with Web-based zone and ID creation services (124) according to one embodiment of the present invention. Zone-host server 105 provides zone-hosting services represented herein by zone/ID services software 124. Zone host 105 is represented logically herein as a single server, however one with skill in the art will recognize that as an entity providing zone management and firewall routing services, there may, in actual practice, be more equipment associated with the function. The inventor represents host 105 as single server herein for simplicity in illustration only. A more detailed example of zone-host architecture according to one embodiment of the invention will be provided later in this specification. As previously described above, zones uniquely identify a genre and a user. Hosted zones enable server-based activity and local computer-based activity with synchronization of the two. A user 401 has an instance of zone wizard or manager 118 executed and running on a local computer for the purpose of creating zone architecture and zone IDs. User 401 has computer connection on-line through ISP 102 to backbone 104 and zone-host server 105 offering Zone/ID services 124. In this case, server 105 thereafter hosts the zones created by the user and wizard 118 is served in this example as a series of Web-forms 402, for creating zone architecture, and 403 for creating identities specific to created zones. In this example there is a zone 404, a zone 405, and a zone 406 all created with the aid of Web-forms 402 and 403. In a one embodiment zones are first created and then identities are created for each zone. Shopping zone 404 has a directory for including zone-approved contacts. Contacts may be added singularly or selected and imported from other applications. The contacts added to a zone will be privileged with the user identity and contact parameters attributed to that zone for enabling correspondence between the zone owner and the approved contact. Contacts may also be added to zone contact lists implicitly as a result of workflow activity, if a rule is configured for the purpose. It is noted herein that shopping zone 404 does not have a permanent identity associated with it. Rather it has one or more, in this case two ad hoc identities, ad hoc identity 1 and ad hoc identity 2. This might be because the particular user does not wish that any sales or service organizations he or she might purchase from over the network has access to any permanent contact information. The user in this case prefers to use a temporary email address for example as the only means of contact with an organization. To illustrate a simple example, identities for shopping zone 404 could be temporary email addresses used to conduct online transactions with selected organizations that then would be listed as approved contact entities for zone 406. Zone-host server 105 through an identity creation service provides the temporary email addresses. In actual practice the host owns a domain and sub-domain for enabling users to apply for ad-hoc identities that can be used until such time a user no longer requires the address. In one embodiment a generic email address domain can be provided to all subscribers to use when applying for an ad-hoc identity wherein the user creates the identity portion or name portion for each address. Ad-hoc identities enable users to keep consumer related mail segregated from their other identities used for personal correspondence, work-related correspondence, and other correspondence where wading through sales-related adds, service offers, and so on is not desired. An ad-hoc identity facilitates correspondence with a service organization, for example, until the user no longer desires or requires communication with that particular contact. At that the time the ad-hoc identity can be expired from service leaving the contact with no simple way to reach the user. Similarly, the contact can also be purged from the contact directory if desired, or the next time correspondence is desired with the particular contact a new ad-hoc identity can be created. Another advantage for using ad-hoc identities is that if the contact compromises the identity by providing it to third parties then the user can simply expire the identity. Personal zone 405 has a user identity of [email protected] used for personal correspondence with friends and other trusted contacts. Zone 405 also has an ad-hoc identity that can be used for example in correspondence with some contact entities like a dating service for example, where the user will correspond with a contact for a period before letting that contact have access to the users permanent identity. Work zone 406 contains the users work identity [email protected] used for work correspondence. An ad-hoc identity is similarly acquired for temporary work relationships where it is not desired that the contact or contacts have permanent access to the user. All of the users work associates would be listed in the contact directory for zone 406. In typical application for zones where there is at least one permanent identity and at least one ad-hoc identity, the contacts listed in the directory would be associated with one or the other appropriately so that outgoing messages do not provide the wrong contact with the wrong identity. It is also noted herein that zones 404-406 each have at least one inbox. Inboxes for the illustrated zones may include identified folders and sub-folders that are specific to certain messages or message threads involving correspondence with certain contacts as described above with respect to FIG. 3. In typical practice of network hosted zone management, after a user has created zones, server 105 functions as a store and forward server that can receive correspondence addressed to the hosted zone identities and route the messages to the appropriate inboxes and folders based on identity of user (recipient) and contact (sender) enforced by firewall. Server 105 becomes the user's email server; phone message server; IM server; and voice server. User 401 may connect to server 105 and view stored messages through a portal page user interface (UI) dedicated to and personalized for that user. Several different views can be presented and the user may delete, download, or view messages and can reply to and send messages from the same portal interface. If the user has a personal email account at email server 110, server 105 can be designated as a forward destination for all email activity addressed to the original account. The forwarded email may be sorted according to zone policy and may be retrieved using computer 401. Likewise, server 105 can be configured as a routing destination for voice calls (VoIP, etc.) coming in through gateway 122 to voice server 109. The user may create telephone numbers to give to contacts and may have calls to his or her own static personal numbers (cell, landline) forwarded to server 105 for voice message routing into appropriate zone inboxes for voice messages. If user 401 maintains an open-line connection to server 105 for a definitive period such as a work period, the user operating a computer-based telephony application may take live calls filtered through appropriate zones. If a user desires, he or she may turn off zone-host services for a period of time and receive and send messages directly without inserting server 105 into the routing paths. In any case, zone configuration, contacts, and messages may be synchronized between server 105 and station 401. Synchronization between the server and a remote user station is not required however to practice the invention. FIG. 5 is a block diagram illustrating possible interaction paths between an IOM client, network peers and service providers according to an embodiment of the present invention. IOM client 120 contains identity-oriented firewall 119, replication manager 202, zone manager 118, and configured communication zones 200. Client 120 might run locally on a user desktop computer, a laptop computer, and in light versions, on other network-capable computing devices having a means of display and input. The network side of this example (within the domain of network 101) contains service providers 106-112 introduced with respect to FIG. 1 above, a zone host implementation (124) and IOM peers 500, which encompass other users operating all or a portion of an instance of client 120. In this example, IOM client 120 has numerous zones 200 set up for communication. Zones 200 reading from left to right in zones 200 include a personal zone, a work zone, a collection zone, a sports zone, a hobbies zone, and a community zone. One with skill in the art will recognize that the number and label of zones 200 configured for client 120 may vary widely. In one embodiment, typical zone suggestions like work, personal, family, etc, might be provided and to some extent already set up for a user. A user may build upon the model by adding more zones as required. Although contacts and even identities can be shared between zones if desired, directories for each zone may also be zone specific. Each zone might have one or multiple inboxes including private and shared inboxes. If zones 200 are hosted zones then the functions of zone manager 118, firewall 119, and replication manager 202 are performed at network level and do not specifically have to be provided locally although they may be. In a zone-hosted embodiment synchronization between on-line and desktop data may be ordered for downloaded/uploaded materials and messages. In this case zone architecture (zones 200) is duplicated at both locations. In this way a user may view or access data on-line using any supported network-capable device including a normal telephone in some IVR-assisted embodiments. In the event of non-hosted zones 200, then the replication, zone management, and firewall functions are all performed within client 120 where they are illustrated in this example. Any of service providers 106-112 identified with respect to FIG. 1 above might interact directly over the network with client 120 in the case of non-hosted zones 200. Firewall 119 cooperates with replication manager 202 to ensure that messages requiring local replication and local distribution to appropriate zone specific inboxes occurs. For example, if an email from a family member is assigned to an inbox within the personal zone it may also be replicated to another inbox within the same or even different zone if zone policy allows the replication. It is noted herein that service providers 106-112 and peers 500 may connect from a network other than local Internet 101. For example, one service provider may be a telephony integration provider or carrier through which an interaction or event that will be routed to IOM client 120 is sourced from the PSTN network or another communications network such as a wireless network and carried through network 101. Similarly, peers 500 may be connected to the PSTN (telephone) or another network and interact with client 120 through network 101. Zones 200 may not all belong to a same user for a given IOM client 120. It is possible to allocate zones to other users. For example a zone administrator may control the personal zone, while a different family member may own the hobbies zone. A replication rule may be set up by the administrator to replicate email assigned to a specific inbox within the hobbies zone to a designated inbox within the personal zone. Such a replication rule would be an explicit rule that may override contact/identity policy thus overriding firewall protection. IOM peers 500 represent other users that are operating with the software of the present invention and therefore have their own client versions installed, which may be hosted or not hosted. Peers 500 would interact directly with specific service providers 106-112 (depending on communication form) to communicate with the user through firewall 119 in application 120, which actually forms the final zone-specific sorting or routing. In one embodiment where a message is replicated to more than one inbox as part of a collaboration workflow, and the message requires a reply from only one of the involved parties, one user may reply to the message, the action causing notification to the other users that they need not reply to the message. Alternatively if zones 200 are hosted, then peers 500 and service providers 106-112 would interact directly with services software 124 to propagate text messages, voice messages, and so on. In this case, the server associated with routing an interaction would publish the IP address, telephone number, Enum number, etc. of the client domain maintained by the server. Enum is a known protocol for assigning contact parameters to any networked device or application and renders that device or application accessible from the same or connected networks. In the case of hosted zones it is noted that when a user connects to the service (124) from a client-enhanced, network-capable device, synchronization may be automated meaning that all messages that have been routed to service-side inboxes and folders are simply synchronized with the user's resident zone architecture if present. In the case of access with a non-client enhanced device, interaction and management can still be performed, as is the case with Web-based email programs for example wherein a user may view mail and download copies without erasing the server-based messages. It is also noted herein that when a user is connected live to services 124 then real time interaction is possible. FIG. 6 is an architectural overview 600 illustrating an example of replication of messages according to an embodiment of the present invention. Overview 600 encompasses Internet 101 and an exemplary IOM client domain 603. Domain 603 may represent one IOM client having multiple accounts or it may represent more than one separate IOM client account resident on one machine. In the case of separate accounts (3 in this case), they may be distributed to more than one networked machine wherein each machine shares a same and active Internet connection such as a DSL connection. In this example according to one embodiment of a single client having multiple accounts, IOM client 603 is integrated for more than one user. An administrator 1 is illustrated within client 603 and is represented herein by a dotted rectangle 606. An administrator 2 is illustrated within client 603 and is represented herein by a dotted rectangle 605. A non-administrator is illustrated within client domain 603 and is represented herein by a dotted rectangle 604. Assuming for example that IOM client 603 is used by a family, then administrator 1 (606) might logically be a father, administrator 2 (605) might logically be a mother, and non-administrator (604) might logically be a son or daughter, the aggregate comprising a family sharing one IOM client. In this case, replication of messages is governed by zone policy, with replication ordered across the included user accounts. This case can exist regardless of whether zones within client 603 are hosted or not. It may be assumed for purpose of discussion that zone host 103, which is accessible to client 603 through ISP 102 and backbone 104, hosts the illustrated zones. In the zone-hosted embodiment, all firewall routing, zone management, and replication is performed at server-side. Within zone host 103 is illustrated a portal server 601, which is analogous in a logical sense to server 105 described with reference to FIGS. 1 and 4 above. Server 601 serves as a Web interface to, in this case users 604-606. Another server icon is illustrated within zone host 103 and represents any other included equipment that might be provided to perform services such as routing, zone management, zone configuration, and so on. Zone host 103 has a zone policy base 602 that is partitioned per client, and may be further partitioned if more than one user is classed as one client. Policy base 602 contains zone policy and certain zone management options available to, in this case, administrators of IOM client 603. It is noted herein that administrator 606 has a personal zone (P-Zone) that is divided into a private portion and a shared portion. Administrator 605 has a personal zone similarly divided into a private portion and a shared portion. Non-administrator 604 has a personal zone that is divided into a shared portion and a private/screened portion. There may be other zones attributed to each account however only a personal zone for each account is illustrated for purpose of discussion. Administrator 606 has a private inbox IB where only mail addressed to the appropriate identity (A1) for that zone is deposited. Administrator 606 has 2 inboxes (IB) in the shared area or portion of the personal zone. One shared inbox accepts all messages addressed to family@home. The remaining shared inbox of administrator 606 accepts messages addressed to the identity of non-administrator 604, the messages deposited there by rule. Administrator 605 (A2) has a personal zone with 3 inboxes set up identically as that described above accept for the private inbox has the identity of A2@home attributed thereto, the at-home identity of administrator 2. Non-administrator 604 has one illustrated inbox where all messages to NA@home are deposited. In a zone-hosted embodiment, Firewall routing, Zone management, and Message replication for the emails addressed to A1, A2, Family, and NA are functions performed within zone host 103. However for purposes of simplicity in illustration the 4 mentioned zone identities are illustrated in a rectangular box logically representing function performed in this case at portal 601. Assume that email server 110 has forwarded (SMTP) an email addressed to A1@home to portal 601 for routing. The message A1@home is private (not to be shared) and is routed to the private inbox of A1 personal zone as illustrated by logical a routing path (dotted line). Note there are no replication rules that apply and no replication is performed. Similarly, a message addressed to A2@home is routed to the associated private 113 of administrator 605 with no replication. For email messages addressed to the family identity=family@home, A1 and A2 have access to a copy of the email through a replication rule. The rule might state that for the identity=family@home, replicate to P-Zone (A1), shared Inbox (A1, A2), and to P-Zone (A2), shared IB (A1, A2). Following a hierarchy of administrative power, the message may be routed originally to administrator 1 and then replicated (R) to administrator 2. In this example, any email messages routed to non-administrator 604 (NA@home) are replicated to another shared inbox set-up in both P-zone A2 and identically in P-zone A1. IB NA then is a monitored Inbox that enables administrators 606 and 605 to see messages routed to non-administrator 604. In a family situation, the above-described feature represents a parental control feature. Contact (sender) identities for those entities corresponding with NA@home are kept in a directory generic to P-zone 604 (non-administrator). The contacts being monitored may be replicated to the directories of P-zone A1 and P-zone A2 as “monitored contacts”. After some given period of monitoring, either A1 or A2 may delete the contact from the appropriate contact list to nullify replication to that zone of emails to NA@home from the specific contact. Provided that both “parents” delete the contact being monitored from their directory future emails with that “approved” contact will be routed to a private/screened 113 in the P-zone of NA. In one embodiment a sub-rule may also be provided that replicates a deletion action performed to delete a contact whereupon if either A1 or A2 deletes a contact related to emails routed to NA then the contact deletion will replicate to the contact list of the P-zone directory of the non-initiating parent. In this sense, zone-specific policy rules may be created based on identity/contact pairs or on identities or contacts separately. For example, if a contact sending mail to NA@home is to be banned, then instead of deleting the contact from a list of monitored contacts, it is moved to a contact blacklist. In this case the list is replicated back to the zone hosting service and published, for example, in policy base 602. Subsequent messages from that contact may be blocked or “killed” by the zone firewall regardless of client identity. Moreover, a contact may also be placed under partial ban. For example, A1 may decide that messages from a contact banned for P-zone of NA are still appropriate for sending to P-zone A2. For example, if a newsletter about drugs is periodically sent to identities A1, A2, and NA@home from the same contact then messages from the contact to NA@home (contact/identity pair) are the only ones blocked by firewall. It will be apparent to one with skill in the art that zone architecture can be shared by more than one user and replicated for more than one user without departing from the spirit and scope of the present invention. In a case where there are multiple separate client applications distributed to machines or workstations on a LAN, for example, then integration and control by one or more administrators is still possible through policy-based administration. A separate integration tool may be provided for the purpose of integrating multiple client instances on separate machines that function, for example as a service business or the like. FIG. 7 is a block diagram illustrating architecture of a personal zone 700 according to one embodiment of the present invention. Personal zone 700 has a private directory 701 and, in this example, a shared directory 703. In one embodiment, private directory 701 and shared directory 703 are part of a physical single zone directory with designation of shared for the entries that are shared. In another embodiment, a separated shared directory may be provided. Private directory 701 contains all of the contacts that have firewall access to the user's personal zone 700 where no other user has firewall access to view that portion of zone 700. Contacts may have a number of actual contact parameters attributed thereto. In this case 1 contact is illustrated as an office ID for a contact Joe Smith. Joe's office email address is [email protected]. Joe's ID# for work is his workplace telephone number of (919)-942-7068. In one embodiment some number other than a telephone number may be provided as a contact ID number. Joe, in this example, is an associated at work and also a family friend. Therefore, shared directory 703 lists Joe with respect to his home ID. Contact parameters listed for Joe's home ID are an email address [email protected] and a telephone ID# 919-942-1792, which is a number for reaching Joe at his home. Personal zone 700 is analogous to personal zone 606 described above with reference to FIG. 6. It may be assumed that there are two inboxes associated with zone 700, a private inbox and a shared inbox. Messages incoming to zone 700 from [email protected] may be considered private to the user and therefore are routed to a private inbox. The fact that the private email contact for Joe is a work email may indicate that the collaboration between Joe and the user is private and not to be viewed by any other persons. However, in order for messages from Joe to be routed to the private inbox of the user, in one embodiment, he has to have access to one of the user's identities that are set up for the personal zone 700. In this example, in private identities 702 there are 3 personal IDs set up for zone 700. In some embodiments there may be only one personal ID set up for zone 700. Personal ID# 1 is [email protected] with an ID# (telephone) of 760-603-8822. It is noted in this example that a second ID for Chris is the same email contact parameter as the personal ID. In this case the user's ISP email account is the same as his personal zone ID. In this case all email messages addressed to [email protected] are replicated to the personal inbox of Chris as long as the sender is listed in private directory 701. Chris may import trusted contacts from is ISP account and paste them into directory 701 and in some cases into a replication directory (not illustrated). A third private ID for zone 700 is listed as a portal ID [email protected]. All messages addressed to [email protected] will make it through to the private inbox so long as the senders are listed as contacts in private directory 701 and in some cases, in a replication directory. A replication directory contains contacts approved for replication to inboxes other than default account inboxes. In a zone-hosted embodiment, the service entity can intercept email sent to various and unrelated email accounts held by Chris and can replicate only those emails where the sender is listed in directory 701 so that Chris may access all trusted email from one interface. However, in another embodiment zone 700 may be set up with a single identity that is unique such as [email protected]. In this case Chris may elect to physically “share” this identity with trusted contacts that normally send email using one of Chris's other identities by sending the contact an email where the identity is listed in the from field of the message. If the contact chooses to use the identity but he or she is not listed in directory 701 then the firewall application might alert Chris that a non-listed contact has your identity. An option may be then presented for enabling Chris to add the sender address to directory 701. Moreover, a contact might be added virtually without giving the contact knowledge of a zone identity just for the purpose of having emails from that contact routed to the private inbox of zone 700 for viewing. In this case a special rule might be set up that directs all emails from a specific contact addressed to a generic identity (other account) to be routed to or replicated to the private inbox of my personal zone 700. This can be accomplished by equating identities. When replying to messages received from the contact the generic email interface would automatically be called up and the from address listed would be the email account address of the specific email account and not the personal identity of zone 700. There are many possibilities. A fourth ID listed in private identities list 702 is an ad hoc identity. An ad hoc identity allows Chris to temporarily correspond with contacts through zone 700 where the contacts are not granted firewall access to a permanent zone identity. In this case, the ad hoc identity is [email protected]. This ad hoc identity allows Chris to do personal shopping, for example, from private zone 700. Chris may share the ad hoc identity with outside entities by sending them email using the identity such as when shopping. The entities receiving an email from the ad hoc identity perceive the identity to be the email address of Chris Jones and will correspond with Chris using that email address. Such entities will, temporarily, be added to private directory 701 with a constraint to the ad hoc identity (temporary contacts). At such a time when the life of the ad-hoc identity expires, the entities no longer have firewall access to Chris and are then purged or archived from directory 701. In this way, Chris may correspond with non-trusted contacts for any purpose without divulging a permanent email identity for example. Zone 700 in this example has shared identities 704 and thus, presumably, a shared inbox. Shared identities 704 are identities that are also provided to one or more zones other than zone 700. A first listed identity in shared identities 704 is [email protected] with an ID # 760-603-8823, which may be the family telephone line accessible to anyone in the family. This identity may be a single identity for a family zone that is, in this case shared with zone 700. All emails addressed to [email protected] are routed to the family zone. Certain ones or all of those messages may be replicated to a shared inbox of zone 700 provided the senders of those messages are listed in shared directory 703. [email protected] with ID# 919-942-1792 is a family contact whose messages sent to the family ID from the contact ID are routed to the family inbox and replicated, in this case to a shared inbox of personal zone 700. In this case [email protected] is listed in the directory for the family zone and in directory 703 (shared across zones). A second ID listed in shared identities list 704 is a family member ID [email protected]. with an ID # of 760-603-8823. This ID belongs to a family member Justin, for example, and might be a single ID for Justin's inbox of his personal zone. Certain contacts sending email to Justin are replicated to a shared inbox of personal zone 700 provided those contacts are listed in directory 700. In this case, if Joe sends an email to Justin using [email protected], that message will be replicated to zone 700, perhaps in a shared inbox adapted for the purpose. In this way Chris has access to all emails sent to Justin by Joe. If Chris decides that he no longer needs to see email from Joe sent to Justin he may simply delete [email protected] from shared directory 703. However, it may be that Chris also corresponds with Joe regularly using the contact identity [email protected]. In this case, the identity [email protected] would be retained in private directory 701. In this way messages from Joe to Justin would not be replicated because [email protected] is not a private identity in list 702. In one embodiment, all email addressed to Justin's inbox might be initially replicated to a shared inbox accessible to Chris with the sender addresses automatically added to shared directory 703. After some monitoring, Chris may delete any of the contact listings thereby flagging that contact listed in Justin's personal zone directory so that further email from that contact is not replicated. Similarly, the deleted contacts may later be reactivated to directory 703 if Chris desires to resume monitoring email messages addressed to Justin sent from the deleted contacts. Zone policy is what determines final routing of all messages. In one embodiment telephone numbers can be similarly treated. For example, all telephone calls from Joe at 919-942-7068 can be routed to 760-603-8822 even if Joe dialed 760-603-8823, which is the family telephone. In this case a rule may exist that specifies that all calls from Joe at his office should be private and should ring the private line of Chris (8822). This can be accomplished either at the level of the network (hosted zones), or by an in-home routing application integrated with a home computer network. Telephone routing may also include computer-based telephony applications as well without departing from the spirit and scope of the present invention. FIG. 8 is a block diagram illustrating a hosted email account firewall application according to an embodiment of the present invention. In this example a user has three separate email accounts 800 set up according to normal protocols. These are an email account 1, an email account 2, and an email account 3. It is assumed for purpose of discussion that email accounts 1-3 have separate user email addresses associated therewith. According to one embodiment of the present invention, activity related to all three accounts can be aggregated through a single interface using one method of the present invention in a zone-hosted embodiment. At the bottom of this exemplary diagram there are three zone inboxes illustrated. By label, these are Inbox Zone1, Inbox Zone2, and Inbox Zone3. A user may elect that the service of the present invention intercept email from designated email servers of accounts email 1-3 wherein the senders of the intercepted emails are listed in directories of inboxes 1-3, which are zone specific. Contacts that have sent email to the user using a To: address associated with any of accounts 1-3 can be listed in any of directories associated with zones 1-3. Zones 1-3 might, in one embodiment, be adapted with any of email addresses from accounts 1-3 as user identities. In such a case of hosted zones, the service accesses each of the email servers attributed to the user through accounts 1-3 and retrieves all email messages stored for the user that exhibit the sender identities listed as contacts in zone directories. These email messages may then be deposited in a message queue 801 provided for the user at the network service portal hosting the zones on behalf of the user. A message filter 803 using may provide message filtering such as virus filtering and the like using a variety of known filters 802. This process may be optional in one embodiment because it might be assumed that since the user has listed the contacts in zone directories they would be those contacts that are trusted. An email parser 804 then checks each email message for sender address (contact) and sends the information to firewall application 805. Firewall application 805 is analogous to firewall 119 described further above. Firewall application 805 may then check the sender address of a message against zone/identity rules to determine which zone inbox to route the message to. In a simplest case the rule is simply the zone that has the address listed. In this embodiment only the contacts that are listed in a specified zone directory can send messages that are redirected or replicated from email servers to the appropriate zone inboxes. In this case the user may open a zone and see all of the email from the listed contacts and can reply to those contacts from the zone inbox transparent to each contact. In another embodiment zones 1-3 have single unique identities and do not include generic user email addresses attributed to other user accounts. In this case the user can import those trusted contacts into zone-specific directories and can send them email from a single interface containing the user identity for the zone that the user wants the contact to have firewall access to. If a contact chooses then he or she can send email directly to a granted identity address thus addressing the email server of the system, which then uses sender/identity pair matching to ensure that the email is routed to the appropriate inbox. Firewall 805 is adapted to alert a user, for example, if a user identity has been compromised (zone policy violation alert). If a listed contact has shared a unique user identity with another user who then sends an email message to the user using the identity, the firewall alerts the user of a zone policy violation (correct user identity; non-listed contact). The user has an option of adding the non-listed contact or revoking the identity privilege of the contact that compromised the identity if that contact can be identified from a list of one or more contacts that had firewall access to the compromised identity. Email history might be useful in identifying such a contact. For example, the non-listed contact might be a CC or BCC of a message previously sent to the user from the contact that compromised the identity. Another option might be to simply blacklist the non-listed contact for future reference. Still another option might be to create an ad hoc identity and reply to the non-listed contact using the identity informing the contact that the old address is being replaced with a new one. In this case the non-listed contact may adopt the new email identity, which can be revoked at a later time. In a preferred embodiment only trusted contacts have firewall access to any of the user's resident zone identities for email or other correspondence. In this respect all specific zone email identities are paired to email contacts that are granted firewall access to them. Firewall protections ensure that no messages are improperly routed. Outgoing messaging is also protected by firewall 805 in a preferred example. Zone identities in the case of email for example are all associated with a single email account that is useable with all of the created zone identities. A user can work from within a zone to send and receive email where the contact list is specific to that zone. A user may also work outside of a zone initially when sending email, however if the user types a contact or selects on from a contact list, the action by default causes zone identification by some graphic indication such as the appearance of a zone-specific icon or skin in the interfaces the user is working with. FIG. 9 is a block diagram 900 illustrating components and function of an identity oriented firewall application 119 according to an embodiment of the present invention. In a preferred embodiment of the present invention, IO firewall 119 controls interaction flow in both zone-hosted and non-zone-hosted embodiments. In this example, a plurality of interaction or media queues 902 are provided to queue incoming interactions. Queues 902 can include, but are not limited to an email queue, a voice mail queue, a newsletter queue, a telephony queue, a presence queue (IM etc.) and so on. A media handler (not illustrated) may be provided, in one embodiment, for each distinctly different type of media supported by the system. A media handler may be adapted to recognize any supported interaction of media type and to ensure that the correct media type enters the correct queue type according to zone policies enforced by firewall 119. In one embodiment of the present invention, queues 902 can be implemented with a single interaction queue that sorts and prioritizes all incoming interactions. In a live embodiment where a user is connected for communication, queues can be adapted to queue live calls waiting and so on. Firewall 119 is the main application between any sender of a media interaction and the final user destinations for the interactions whether they are live interactions or queued messages or the like. Firewall 119, in this example, has an identity analyzer 906, a content analyzer 904, and a directory manager 905. An incoming message 901 is illustrated waiting to be processed in queue(s) 902. Identity analyzer 906 is a software component that attempts to determine the identities associated with any incoming or outgoing message. For example, identity analyzer begins processing an incoming message by looking up the sender identity or ID of the entity responsible for sending the interaction. Identity analyzer also looks up the user identity, which is the destination ID for message 901. In many instances all of the information required for firewall 119 to successfully route message 901 might be determined by identity analyzer 906. However, content analyzer 904 can be consulted in an event that more information is required to successfully route message 901. In an example of email, message 901 should have a sender ID and a user ID (destination of message). The unique sender ID and user ID combination may define a specific zone inbox, illustrated herein as inboxes 908, as an appropriate destination for message 901. In this case the user ID is the zone-specific ID and the sender ID is listed in the approved contact list in the particular directory for that zone. Firewall 119 determines which zone or zones is appropriate for message routing and determines if there are any zone violations. If the sender ID is not correct for the user ID found in message 901, for example, then firewall 119 attempts to further analyze message 901 before triggering a zone policy alert or an outright zone violation. One additional step is to check CC and BCC identities in the message. If these identities are listed as approved contacts for a particular zone, then a zone policy alert (short of a violation alert) may be sent to the user asking the user for permission to ad the new sender to the contact list for the zone. In this case, the new sender was given the user's identity either directly or indirectly and the user is asked to arbitrate routing of the message. If the user is not available then the message may be filed, after a period of time into a quarantine folder of the inbox. Likewise, if a sender approved as a contact for a particular zone, but uses a user ID of another zone firewall 119 attempts to resolve the issue by checking if the user is a contact in the other zone. If not, then there may be a zone policy alert. It is noted herein that a fact of a sender being listed as a contact for a particular zone may by default enable routing of the message to the zone if there are no other possibilities. In one embodiment message 901 may have more than one user ID listed as a destination. In this case, firewall 119 will check sender ID against zone directories of each zone and if found in a particular zone directory then that zone receives the message. It is important to note herein that in some cases with some media types may result in no detectable sender ID such as a blocked telephone number. However, a user ID for a zone might include a telephone number with a unique extension identifying the zone. In any case, a user ID parameter must be present in order for a message to reach queue(s) 902 to be processed for further routing. If for some reason zone policy cannot be determined because identity analyzer 906 cannot determine sender ID, then content analyzer 904 may be called to help determine origin of the message. For example, a reply related to an ongoing communication between several parties might be allowed if through content analyzing, it is determined that the message belongs to a particular message thread specific to a particular user zone and the user wishes to accept all content generated by the thread. In one embodiment where binary attachments are involved such as those that might be taken from a binary news server, then content analyzer can be called on to verify content of the attached file as content that the user is interested in or has subscribed to. In this case, a zone violation might occur if a content poster identity is found in a zone directory as an approved contact but the content does not fit an approved profile of content allowed for download. It might be that a malicious user has compromised the poster's identity and is attempting, disguised as the legitimate poster, to post undesirable material. In a case where a user might download content of any kind, content analyzer might be called by default to verify content against a content profile accepted by the user for a particular zone. In some cases, a contact might be detected and/or validated as legitimate for a zone according to content analyzing. For example, if a contact is not listed for a particular user zone according to use of user ID, but the content analysis shows that the attachment could only have come from the approved contact then the correct contact information for the specific zone can be implied beyond reasonable doubt. Encryption keys, digital signatures, and other forms of validation can be associated with a particular contact so that if the contact uses an unlisted or otherwise unknown parameter, the contact may still be determined and validated. In a preferred embodiment of the present invention, content analyzer 904 functions as a back-up component to identity analyzer 906. However, in some embodiments, content analyzer 904 is called by requirement where binary attachments are concerned such as to verify legitimacy of a contact listed as a news group contact, for example. In this example, directory manager 905 controls contact whitelisting, contact blacklisting, and manages identity contact history tracking. For example, new identified contacts that have been validated for a zone, but not previously listed in a zone contact directory can be added to a zone directory and provided as a whitelisted contact. Similarly, contacts found to have compromised a zone identity or found to be responsible for undesirable content can be deleted from zone directories and added to a blacklist. Identity analyzer 906, content analyzer 904, and directory manager 905 are connected in this example by a logical bus structure 907. A message router 911 represents routing function for all interaction. Router 911 represents final destination routing caused by firewall 119, more particularly zone determination and inbox specification. It is noted herein that router 911 may represent different routing applications according to various embodiments. For example, in a zone-hosted environment there my be one or more physical routers involved in interaction routing depending on design and media types supported. In a non-hosted environment like, for example, a desktop implementation, routing applications normally in use or set-up for a specific media type may be supported. In all cases however, final zone and inbox sorting is enforced by firewall application 119. In practice of the present invention message flow generally follows a path beginning with identity analysis then content analysis (if required) followed by directory management (if ordered). Messages that are zone policy violations, including spam and other rejected messages may be sorted accordingly. In this example, each zone has a quarantine folder 909 provided therein and adapted to receive messages that otherwise cannot be successfully filed according to zone policy. A data access and update module enables a user, through an interface, to view and edit current zone policy and to add any explicit zone policy rules that may be created to override certain policy issues. One with skill in the art will recognize that in the case of firewall 119 identities that make up contact or sender information and user or zone-specific information will take the form of normal contact parameters of the media types supported. Email identities will be of the form of email addresses for example while telephone identities will be in the form of a telephone number. All routable media types can utilize zone specific variations for user identities and in the case of a peer using the software of the present invention, sender identities (contact identities from the user perspective) may be as varied as user identities further aiding in identity pair management. FIG. 10 is a block diagram illustrating firewall alert features according to an embodiment of the present invention. A user 1001 (computer icon) may accept messages in a zone-specific manner and may send messages in a zone-specific manner according to identity oriented zone policy enforced by firewall. In this example, user 1001 is working from within an exemplary zone 1002 labeled Ebay, which for discussion purposes has an email identity of [email protected]. In this example, email is one of communication media types supported and sender/user Ids are of the form of email parameters. A collection of exemplary zones 1004 belonging to user 1001 is illustrated at left in the diagram and contains a golf zone 1005, a music zone 1006, a business zone (Ebay) 1007, and a car zone 1008. User 1001 has contact directories for each zone and identities for each zone. Business zone 1007 is the zone currently being used. This example is of a desktop implementation of the software of the invention that is not zone-hosted. A data store 1009 is provided to contain all of the actual zone data and activity history. Data store 1009 can be provided in dedicated fashion from memory resources generic to the computer of user 1001. The data may be provided, for example, as a dedicated portion of the user's hard drive. In this case, firewall implementation is on the computer. In another embodiment the firewall application and data may be hosted on an appliance or peripheral, perhaps a physical router and may not be present on a PC. Each of the zones owned by user 1001 has a user identity, which is some form of joe i.e. joe, jb etc. A user identity for a zone may be permanent (lasting the life of the zone) or temporary as in an ad hoc identity. For example a user identity for golf zone 1005 might be [email protected]. A user identity for music zone 1006 might be [email protected]. The identity for business zone is [email protected] as described above. The identity for zone 1008 might be [email protected]. These identities are one that user 1001 is willing to share with certain contacts on a permanent or, in the case of ad hoc, temporary basis. A pop-up alert 1000 represents an identity/zone firewall alert pop-up that may be sent to alert user 1001 of any violations. Pop-up alert 1000 may be displayed at any time of need or convenience on the display of user 1001. In this case, pop-up alert 1000 contains more than one alert for discussion purposes. Typically one alert may only contain reference to a single violation of zone policy. Because user 1001 is working from within zone interface 1002 (email) of zone 1007, his interface has some graphic representation of the specific selected zone. Alert 100- contains two alerts illustrated. These are an outgoing message alert 1008 and an incoming message alert 1009. Alert 1008 (also labeled alert 1) reads that a message user 1001 is attempting to send violates zone policy. This may be because the user is attempting to send email to a contact not listed in a directory. The firewall breach is based on a non-listed contact. More particularly, [email protected] has attempted to send an email to someone that is not listed in a directory of zone 1007. Pop-up 1000 can immediately be generated because the system knows that Joe is already working within zone 1007. In this case Joe sends a message to a contact [email protected], which is not listed in a directory for business zone 1007. Before the email message is queued for send, alert 1008 is displayed and has an option of accepting the email as addressed or rejecting the email and re-selecting a proper contact or zone for emailing the message. If user 1001 accepts the message as addressed then [email protected] might be added to a directory specific to business zone 1007 for future reference. If user 1001 rejects the message as written then further options are provided accordingly. For example, user 1001 may have intended that Jim is the correct recipient. In this case preserving Jim as the contact in the message may cause the interface to change graphically to represent golf zone 1005 listing Jim as a contact. If golf zone and one other zone list Jim as a contact using he same email identity then a zone list may be presented so that user 1001 may select the appropriate zone, hence user identity for the message. Zone alert 1009 also labeled alert 2 reflects an incoming message violation where a message is received from [email protected] that is addressed to [email protected]. The violation here is that Dean is not listed in a directory for business zone 1007. User 1001 may arbitrate the violation by adding Dean to a contact directory for business zone 1007 or the message can be rejected. If the offending message is rejected in this case, a problem still remains as to how the contact [email protected] became aware of the user identity [email protected]. CC or BCC records on any activity history conducted with the address [email protected] through zone 1008 may shed some light if a contact found in CC or BCC records is one that is also listed in the directory of business zone 1007. It is possible that the contact may have shared the user identity information with the owner of [email protected]. One option is to send an email to [email protected] directing the recipient not to use the identity or be blacklisted from all zones. Also, the contact identified as a possible source for the identity leak can be contacted and if uncooperative, blacklisted. In case the contact that compromised the user's Ebay identity cannot be distinguished from other contacts listed in business zone 1007 using communication history records, then the user still has an option of changing the identity for the zone. In all embodiments of the present invention, a contact cannot reach a user through any zone wherein the contact identity used in the media type to gain firewall access is not listed in a contact directory of the zone. Other than explicit rule such as for example “replicate all messages from [email protected] to all inboxes”, firewall 119 adheres to implicit identity rules existing according to current zone directories and identities. It is noted herein that contacts using shared identities reach user facilities like email servers and the like directly. However contacts that do not have firewall access to zone identities may still have their communications routed according to contact listing in zone directories if such communication is intercepted by ordered forwarding or by password protected third party access as in the case of generic email accounts. In a zone-hosted embodiment, all communications to any user-related identity of any supported media type can be zone managed. FIG. 11 is an architectural overview of a Web-based service adapted for third-party zone hosting according to an embodiment of the present invention. A zone-hosting service party 1100 is illustrated in this example as a service organization that can provide third-party interaction routing, and zone management services for users on a private level or on a business level. Service provider 1100 is analogous to zone host 103 described with reference to FIG. 1 of this specification. In this example, exemplary internal equipment and exemplary connection equipment types are illustrated to show separated function. A PSTN switch 1101 is illustrated in this example and represents any telephony switch within the PSTN network local to party 1100. The presence of telephony switch 1101 illustrates that clients may access third-party services offered by zone-host 1100 through the PSTN network and a gateway 1105 by way of a telephony trunk 1113. Gateway 1105 can be an SS-7 gateway or any other known gateway adapted to bridge telephone calls between telephone and data-packet networks. Gateway 1105 may be maintained, in one embodiment by the enterprise hosting zone services. In another embodiment, gateway 1105 is leased from a telephony service company or a network provider. PSTN switch 1101 may also direct incoming voice calls destined to clients that subscribe to zone-host services. A laptop computer icon 1102 is illustrated in this example and represents client capability for accessing services through a wireless connection 1114 and an Internet or other WAN backbone 1115. Icon 1102 represents a wireless computer in this example, but may also represent a wireless cellular telephone capable of network browsing or any other network-capable wireless device. A business server 1103 is illustrated in this example and represents any business-to-business (B2B) server. Server 1103 may access zone host 1100 over a network access line 1116 and network backbone 1115. Server 1103 can be an automated system that accesses zone host periodically or one that maintains a session-connected state with zone-host 1100 over a period of time. Zone host 1100 may manage interaction routing and zone management services for many individuals of a business that maintains one or more servers 1103 that enable identity-managed access and, in some cases live session interaction between clients and associates of the business and the business itself using zone host 1100 as a proxy interaction routing and zone-management entity. B2B server 1103 may also be a business-to-client (B2C) server or a client-to-client (C2C) server such as a community portal application practicing presence protocols without departing from the spirit and scope of the present invention. A computer desktop icon 1104 is illustrated in this example and represents individual client access to zone host 1100 through a network-access line 1117 and network backbone 1115. Desktop computer 1104 represents any client or client group accessing services provided by zone host 1100 through network access methods such as digital subscriber network (DSL), dial-up methods, or other known network access methods using dedicated or shared physical lines. Zone host 1100 maintains at least one web portal 1106 through which services may be accessed. Web portal 1106 presents client information according to zone policy enforced by IOM firewall application 1108 represented in the form of a server in this example. Portal 1106, in a preferred embodiment, is a server which may be adapted for HTML, WML, and other data presentation protocols enabling display and data access to clients operating user interfaces adapted for the purpose according to method, equipment type, and protocols used by the client. Zone host 1100 has an interaction router 1107 adapted for the purpose of routing incoming interactions according to zone policy enforced by IOM firewall application 1108. Router 1107 is illustrated logically as a standalone piece of equipment in this example; however in actual practice routing applications may be provided as dedicated applications serving specific media types and may be distributed over more than one physical node. For example, a router may be provided and dedicated to incoming email in the form of a mail service. Another routing application may be provided and dedicated to route telephony calls. VoIP calls may be handled by yet another routing application. The inventor illustrates router 1107 as a dedicated node for purpose of clearly separating and explaining routing function from other functions enabled within host 1100. IOM firewall 1108 enforces all identity oriented routing and sorting of messages and in some embodiments, live sessions according to zone policy. A zone manager application 1109 is logically illustrated herein and is adapted to provide zone and identity creation and management services. Portal 1106 is, in this example, connected to a back-end data server 1110 by way of a high-speed data connection 1121. Server 1110 is adapted to maintain and serve data relating to interaction and communication activity recorded for clients of host 1100. Data server 1110 has access to an on-line data store 1111 that is partitioned according to existing clients of host 1100. In one embodiment, data store 1111 is internal to server 1110 and maintains the actual data relating to communication activity for clients. In one embodiment, the functions of data store 1111, back-end server 1110 and portal 1106 are hosted in a single node. In another embodiment there may be more than one portal server as well as more than one back-end data server 1110 and data store 1111. It is noted herein that the illustrated equipment types of this example are logical implementations only and should not be construed as requirements in form or function for the practice of the present invention. For example, data service, portal services, interaction routing, IOM firewall protection, zone management services, and network gateway services may all be implemented in one or more than one machine in a variety of combinations without departing from the spirit and scope of the present invention. In practice of the present invention according to one embodiment, clients represented by network-capable devices such as wireless device 1102, and desktop device 1104 have direct network access to portal server 1106 by way of backbone 1115 and server access line 1119. In a preferred embodiment server 1106 is a Web portal and the operating network is the Internet network. In this case, a client operating a device such as laptop 1102 forges a wireless connection to the Internet, for example, through a wireless ISP and navigates to server 1106 and further to a particular presentation page maintained for the particular client and accessible through normal Internet address protocols such as URL and URI protocols. Once client 1102 is in session with server 1106, he or she may access and view messages and other communiqués that have occurred since the last time the client logged into the service. A client represented by desktop computer 1104 also has direct access to portal 1106 through UI function and network navigation although in a tethered (wired) embodiment. Clients operating wireless devices and tethered devices can, in one embodiment, conduct live interactive sessions such as telephony or VoIP sessions through portal 1106 during a period of time when they are connected in session with portal 1106. Business server 1103 may connected to portal 1106 using an automated interface adapted to automatically update messages and other activity for multiple clients whose zone structures are represented both in server 1103 and in data store 1111. In one embodiment a separate portal function may be provided and specially adapted to communicate with server 1103 using a machine-readable mark-up language like an XML-based language. In this same embodiment, live interaction may be conducted as well. Zone host 1100 receives incoming messages and, in some embodiments, live voice calls on behalf of subscribed clients and routes all of those incoming communiqués based on zone policy set up for the subscribed clients. For example, incoming voice calls may arrive at host 1100 through gateway 1105 from anywhere in the PSTN network. Interaction router 1107 treats each voice call according to zone policy enforced by IOM firewall application 1108. Router 1107 has a logical network connection to firewall application 1108 by way of internal data network 1118 in this example. Router 1107 consults firewall application 1108 for each incoming communiqué. Firewall application 1108 is responsible for determining identities of the incoming communiqués, more particularly the senders ID (calling party) and the destination ID (receiving party). For asynchronous calls (voice messages) that are not part of live two-way communication between parties, router 1107 routes the messages to back-end server 1110 where they may be queued in the appropriate inboxes (voice message boxes) of the identified clients according to current zone policy of the client. Subscribers may periodically access portal server 1106 to check their voice messages and to download them to their devices. In typical fashion a client would login to server 1106 and provide authentication. After providing authentication, a portal interfacing Web page is presented to the client. The Web page has at least summary information of current and past activity conducted on behalf of the client including indication of whether voice messages are present and what zones and inboxes any existing messages belong to. The client may sample voice messages by browsing zone architecture presented in a navigable tree or by short-cut navigation to the inboxes identified as containing new messages. The client may then download all or selected voice messages to his or her duplicate zone architecture contained on his or her access device. Downloading voice messages is conducted according to current zone policy, which may include replication orders for replicating certain selected messages to particular inboxes or other folders contained on the user's device or to a folder on a selected other device connected to a network that also includes the user's device. A zone manager (Z-Mgr.) 1109 may enforce replication using a message replication application similar in function to application 202 described with reference to FIG. 2. It is noted herein that an inbox or folder designated to receive a replicated message does not require representation by zone architecture for the client at the server side. All that is required is that the server knows the destination of the designated folder on the user device, which can be made known in a download request. When a user requests download of voice messages for example, portal server 1106 retrieves the appropriate data from server 1110 over data link 1121. In one embodiment, a client may access portal 1106 from a PSTN-based telephone through gateway 1105. In this embodiment gateway 1105 functions as a proxy interfacing node holding the live call and interfacing with portal 1106 over a special data link 1120 provided for the purpose. IVR technology may be used to provide a client with means for accessing specific information. Client identities for voice may include telephone extensions that vary for each zone. For wireless cellular clients, wireless markup language (WML) and other wireless data presentation languages can be used. In one embodiment voice sessions may be conducted between clients and callers wherein the calls are routed live through portal 1106. In this case an incoming voice calls at gateway 1105 may be routed according to identity information to a telephony application operated by a subscribing client. The calls are firewall protected, as are voice messages and identities for the client may include Enum identities assigned to client voice applications or telephony peripherals. In the case of routed live sessions Portal 1106 functions as a call bridge and establishes the call connection between the caller and the client's accessing device. Email, news letters and other message types including voice messages and live voice sessions may arrive at zone host 1100 from any network-capable device connected to network backbone 1115. Interaction router 1107 routes each message type according to zone policy enforced by firewall application 1108 as with all other communication. Messages are accessible through portal 1106 according to zone policy and live sessions may also be conducted as previously described. One with skill in the art will recognize that router 1107 is represented logically in this example. In one embodiment there are separate media handlers for each supported media type. The media handlers in such an embodiment are dedicated handlers that are responsible for identifying particular media types of communiqués incoming and for directing routing of those using the appropriate routing applications. Zone manager 1109 enables clients to construct and organize zones and in some cases to create user identities for the constructed zones. In one embodiment, a separate identity creation service is provided for the purpose of creating user identities for zones and any ad hoc identities for outgoing communications. A user may access a zone management Web form or page from portal server 1106. In one embodiment, zone manager 1109 is accessible without requiring portal connection. In such an embodiment, all modifications and additions of zone architecture parameters can be updated directly from server 1109 to server 1110. In one embodiment, all incoming and outgoing communication between a client of host 1100 and other parties is routed through zone host 1100. In another embodiment clients may select a level of zone hosting that may provide routing services for only incoming communication. In still other embodiments some of client zone architecture may be serviced and managed while some of the same zone architecture is not hosted. In this particular example of zone hosting, router application 1107 is essentially dumb meaning that it cannot enforce complex identity oriented policy across one or more media types. Firewall application 1108 outputs routing instruction to router 1107 whichever media type is involved. Primarily, firewall application 1108 is concerned with identities and how they interpolate with zone policy. However as described with reference to FIG. 9 above application 1108 can also analyze attachments, message threads, and may also check email CC and BCC identities and identities included in other recipient list types that may apply to other broadcast-capable mediums like RSS and IM. It will be apparent to one with skill in the art that identity oriented messaging and live interaction may involve several media types supported by a particular clients with multiple identities used for each of those supported media types. In a business environment a server such as server 1103 can be adapted to retrieve messaging for multiple clients having multiple zone structures and identities. Live interaction routing is possible in both business and single user embodiments. In a preferred embodiment of the present invention zone hosting can be applied to one or more zones that are part of client zone structure and can support one, a combination of, or all of the media types and protocols described with reference to FIG. 1. FIG. 12 is a block diagram illustrating software layers and components according to one embodiment of the present invention. In this embodiment software 1200 is illustrated in three basic software layers. These are a data storage layer 1201, a zone firewall layer 1202, and a media presentation layer 1203. Data storage layer 1201 has a data store 1204 partitioned for clients A-(n) and an archive engine 1205 for compiling old history data for clients and storing them in an organized fashion for later access if necessary. Layer 1201 is responsible for maintenance and service of activity data for clients of the IOM service. Layer 1202 is responsible for establishment and maintenance of zone architecture and message replication as well as identity oriented management of communication. In addition to IOM services layer 1202 also manages contact directories, white listing, black listing, and communication history tracking. In this embodiment, zone configuration manager 1213 is included in the domain of firewall application 1212. Also included within the domain of firewall application 1212 is the replication manager 1211. Firewall 1212 has, in addition, a directory management function 1206, an identity analyzing function 1207, a message routing function 1208, a content analyzing function 1209, and a zone authenticator 1210. Media presentation layer 1203 is responsible for presenting media to client subscribers upon request and may in one embodiment serve as interceptors of messages incoming for processing. In this regard a plurality of dedicated media handlers work to identify communication that is incoming and to identify communiqués stored on behalf of any client. Media handlers provided in this example include but are not limited to a voice handler 1214, an IM handler 1215, a binary handler 1216, a news handler 1217, an email handler 1218, and an RSS feed handler 1219. As constructed in this example, application 1200 can be implemented on a single machine such as a desktop computer. In a desktop embodiment, presentation layer 1203 provides one or more UI views of activity conducted by a client according to zone policies. In a server-side hosting embodiment, layer 1203 presents a portal interface (Web page) for each subscribing client or client group. It will be apparent to one with skill in the art that software 1200 can be provided in various configurations including some or all of the described components without departing from the spirit and scope of the present invention. Moreover, software 1200 can be implemented on a single machine or it can be distributed over more than one machine without departing from the spirit and scope of the present invention. Likewise, software 1200 may be provided as a desktop application that may vary in design and implementation from a server-based version used in a zone-hosting embodiment. FIG. 13 is a block diagram illustrating portal interface functionality according to an embodiment of the present invention. A portal interface page 1300 is logically illustrated in this example to show exemplary functions that are provided to clients of a zone hosting service according to a preferred embodiment of the present invention. Interface 1300 is personalized to particular subscribed clients having access to it. Interface 1300 enables IOM management and may be provided according to several known markup language formats used to enable access and manipulation of data through various possible access devices. Some examples include the HTML-based formats and wireless access protocols (WAP) including WML. In this example, interface 1300 is in the form of a browser frame supporting all of the generic browser pull-down menus 1301 and all of the generic browser icons 1302. Like all browser frame architectures, there is an Internet or network navigation address window or bar, which in this example reads http://www.myzoneportal.com/activitysummary illustrating the personal nature of the Web page to a client. Portal interface 1300 may be preceded in delivery to a client by an appropriate login page or procedure. Interface or portal page 1300 has a zone navigation tree 1303 provided in a hierarchical format familiar to most operating systems. Tree 1303 enables direct navigation to inboxes and folders that may be associated with user zones that are established for the client. At the top of tree 1303 is an icon labeled My Zones. Activating this icon such as by mouse over or mouse click reveals zones, labeled Z in this example. By selecting a desired zone, inboxes (IB) and listed folders (F) are revealed. Interface 1300 has a viewable workspace 1304 adapted, in this example, to display new activity that has occurred across all zones since the last user login. Workspace 1304 has a familiar search input window typically provided by a third-party search engine. When online a user may search the Web or prevailing network through this interface. Activity summary information 1306 is, in this example, displayed for view within workspace 1304. Activity 1306 represents a summary of all of the activity across hosted zones that has occurred since the last user login was performed as was stated above. In this example it is shown that the current client has 6 new emails in an IB for zone 2 (Z2), which is a work zone in this case. There is also one voice message queued for the client in the same inbox. A selectable icon labeled Details is provided and associated with the information for zone 2 so that a client may immediately call up the details and any function for viewing and downloading messages. In this example, further activity 1306 is displayed and associated to a zone 4 (Z4), which is a play zone. There are 3 new instant message invitations waiting in an IB associated with Z4. Also displayed are 5 new emails that were deposited in a folder associated to a zone 6 (Z6), which is a music zone in this example. Activity summary information 1306 can be configured to list all new activity that has occurred according to all supported media types not limited to email messages, voice messages, binary files, RSS feeds, news letters, chat invitations and other presence alerts, and so on. Portal interface 1300 has a second viewable workspace 1305 adapted in this case to display details from the summary activity displayed in workspace 1304 through interaction with one of the displayed details icons. In this example, a user has highlighted the “one new voice message” line in summary information 1306 associated with the work zone (Z2) and activated the details icon. In the details workspace 1305 the IB and Z2 heading appears. The detailed description 1311 of the new voice message appears including identification of whom the message is from ([email protected]), and the time and date the message was received. In this case, a play icon and a reply icon are provided within workspace 1305 and associated with message 1311. The play icon initiates audible rendering of the message and the reply icon invokes an appropriate hosted application a user may manipulate for replying to the message. Such an application may be a version of an IMAP email interface that is hosted by the service and enhanced to allow voice messaging. In one embodiment, after sampling viewing activity summary 1306, a user may elect to synchronize the information with his or her accessing device. Afterward, a user may reply to messages and the like off-line using local applications instead of using server-based applications. Interface 1300 has scroll functions represented logically in this example by a vertical scroll bar 1308 and a horizontal scroll bar 1309. Although it is not illustrated herein, each displayed information window or workspace may be separately scrollable (having dedicated scroll functions). Another way a user may obtain ordered views of activity is by using a traditional drop-down menu approach as is illustrated in this example by a drop-down menu 1307. In this case an activity summary view was ordered and displayed as information 1306 and upon further manipulation, 1306. However, other ordered views are possible and should not be limited to views of all messages, specified zone views, replicated activity, shared activity, timeline alerts, general alerts, and archived information. To exemplify other possible views that can be formatted in various ways without departing from the spirit and scope of the invention, consider a zone view of a specific zone. A user may click option Zones from menu 1307 and receive an iconic representation of all of the current zones. By clicking on a detail icon associated with any listed zone, a user may receive a detailed architecture (tree portion) specific to that zone showing the inboxes and folders of the zone. Such detail may be presented for display in workspace 1305. If desired, a user may further order detail by selection of an option, provided for the purpose, for viewing activity for that zone. Selecting the option view activity may then enable the user to browse through the inbox messages and folder contents for the selected zone. Therefore, all of the function provided through navigation of tree 1303 is, in this example, replicable through other functional means such as by manipulating menu 1307. Moreover, mouse over and right clicking on options can also provide a means to drill down to detail in zone inboxes and folders. One with skill in the art of various network-capable devices will appreciate that interface 1300 may both visually and functionally appear differently according to device type, access protocol, and supported media types without departing from the spit and scope of the present invention. In one embodiment, for example, a user may access his or her portal page 1300 using a standard telephone and negotiate available option through such as IVR interaction. A view of replicated activity selected from menu 1307 may bring up a workspace 1304 containing activity information similar in structure to activity information 1306 accept that new messages that were not replicated would not be displayed. Selection of the option shared may call up a workspace wherein all shared components like shared inboxes and folders are displayed. Moreover, shared contact directories can also be viewed through this option. In one embodiment of the present invention a view for time alerts can be ordered by selection the option Time Alerts in menu 1306. In this case workspace 1304 may indicate the existence of any time sensitive activity across all zones. A user may pre-configure certain correspondence threads identified by contact and user identity, for example, as time sensitive correspondence. In this case the timeline related to the receipt of and reply to messages of thread can be displayed along with the message activity summary. In this way a user may be alerted if, for example, if a time window for responding to the latest received message is approaching or exceeding a pre-specified time allotted for response to certain types of messages, or to a threshold time window established a particular correspondence thread involving one or more contact identities. A time alert may be displayed to a user at any time whether or not a timeline view is ordered. Such alerts may appear as pop-up alerts or on an alert bar provided for the purpose. In one embodiment of the present invention an administrative control-view option (not illustrated) may be provided for enabling an administrator to access zone architecture and apply certain service levels to specific zones or zone activities specific to zones or across multiple zones. For example, if a zone architecture reflects a hosted business environment where users might be sales agents sharing zones and/or inboxes and folders, administrative response time rules may be applied for outgoing communiqués that are in response to client requests for information or service. In such an embodiment a response rule for purchase order requests queued in an inbox in an offered products zone might be “respond to all request within 2 hours of queue time” whereas a response rule for customer service in a customer care zone might be “respond within 8 hours of queue time”. An administrator may order a service view, for example, across zones to analyze how well agents are performing. The same embodiment immediately described above can be extended to a non-business or family-oriented zone architecture having shared activity. In this case the administrator could be a parent and response rules can be applied to one or more family shared inboxes to insure that members of the family respond to certain messages in an appropriate time. For example if a grandmother sends an email to a son, it is socially important that the son respond to the grandmother in a reasonable amount of time out of respect. Likewise if a son or daughter is involved in a collaborative school project, it is important that communiqués received from peers involved in the project are addressed in a responsible time frame. There are many possibilities. General alerts can be generated and displayed for users at any time while a user is logged in to the portal system. Alerts related to zone policy violations and other administrative alerts related to account status and so on may be considered general alerts. By selecting view alerts option in menu 1307, the user can view all zone policy and other alerts generated since the last login. A user may also order views of archived information by selecting Archived from menu 1307. Such views ordered can be zone specific views or views across all hosted zones. Portal interface 1300 has an interaction mode option 1310 that allows a user to set interaction status according to presence information. For example, an option Live can be selected if a user wishes to accept live interaction while logged into portal page 1300. An away icon is provided to indicate presence information that the user is logged in and currently away. If a user activates the Live option, he or she can accept live calls, instant messaging, and so on through the portal interface with all interaction conforming to zone policy enforced by firewall as described further above. In one embodiment a user may be defined as a business of multiple users or agents having multiple hosted zones and identities. Live interaction in this case may be a default state for a business having all communication routed to and from the business by proxy with incoming communication routed to appropriate user or agent inboxes and identified telephony extinctions and outgoing communications routed to destinations in a zone and identity specific manner. In the case of hosting a business, portal page 1300 can be provided in multiple instances for the agents that are receiving service. An example would be for multiple agents accessing the server simultaneously from a LAN network of connected devices. A very large business with many agents might have a separate portal server dedicated to hosting the business. A user may elect to operate off-line or not hosted for periods of time wherein hosting services are not used. In this case it is assumed that the user has zone architecture and policy installed locally so that when next online the activity can be replicated or synchronized with the hosted architecture. In the case of live interaction, telephone numbers and extensions can be published in the telephone network at one or more local CTI switches maintained by or leased by the hosting service. IVR services and other telephone network services can be similarly provided and maintained and or provided and leased by the zone host and adapted to cooperate with the portal system so that during live interaction where hosting is performed, incoming and outgoing communications are conducted according to zone policy and identities. One such example might be a contact calling a client where the contact uses a business telephone number to reach the client. An IVR service can be used to identify the contact and purpose of the call. Automatic number identification (ANI) and destination number identification service (DNS) as well as IVR prompting can be used to properly identify the contact identity. The destination number can be assigned to one or more zone-specific user identities including telephone extensions, IP addresses, message boxes, and so on. The host then using the identity-oriented firewall performs the final destination routing to the appropriate live extension or application on the local station of the client (if live) or to the appropriate message inboxes and folders (if away). It will be apparent to one with skill in he art that interface 1300 can have many function variations and view possibilities without departing from the spirit and scope of the present invention. Interface 1300 may be customized for a single client or a client defined by multiple users. The methods and apparatus of the present invention provide a unique capability of managing communication and digital collection according to multiple client and contact identities, which can be personalized according to a variety of zone descriptions. The invention can be implemented with or without zone hosting capabilities and can tie virtually any communication media to zone architecture enforced by zone policy. The methods and apparatus of the present invention empower a user in constructing a social communication environment that successfully excludes undesired communication and provides convenience and security in communication management for a client or client group of individuals. In accordance with the many and varied embodiments described in this specification, the methods and apparatus of the claimed invention should be afforded the broadest interpretation. The methods and apparatus of the invention should be limited only by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>With the advent and development of the Internet network, including the World Wide Web and other connected sub-networks; the network interaction experience has been continually enriched over the years and much development continues. In a large part, network users, both veteran and novice have a basic human commonality in that they all share three basic desires that materialize into behavioral traits when engaging in network-enhanced interaction. These behavioral traits are the desire for communication with others, the desire to collect and/or acquire digital content, and the desire to collaborate with others to help solve some problem or to resolve an issue. As behavioral traits, these basic needs can be expanded into many sub-categories. Communication includes interaction over channels such as Instant Messaging (IM), email, posting boards, chat, voice over Internet protocol (VoIP), analog voice, etc. Collection includes collecting art, knowledge, music, photographs, software, news, and so on. Collaboration includes group discussions, task fulfillment, and any other collective efforts to solve a problem or perform a function. In basic form communication, collection, and collaboration are very tightly intertwined as basic desires. As practices many users may unequally engage in the just-mentioned behaviors. For example, virtually all network users have active email accounts and active Instant Messaging capabilities. Most users have IP telephony capabilities and networking collaboration capabilities, at least installed on their computer systems if not actively configured for use. Many users have peer-to-peer file sharing capabilities, often coupled with communication capabilities. General communication may arguably be the most dominant network practice, followed by collection and sharing of content and network collaboration not necessarily in the stated order. To further illustrate the imbalance of the three core behaviors for any one user consider that some users engage heavily in instant messaging, voice and, or email correspondence, while almost never engaging in file transfers or content downloading. Others engage more heavily in collaboration while lightly engaged in file transfer, content download, and common or casual communication. Still others practice content downloading and file sharing more often than collaboration. One can readily attest that it is difficult to practice one behavior exclusively without also practicing the others to some extent. Software providers have long recognized the need to fulfill these basic desires by providing the capabilities in a single interface and have provided many well-known communication applications that provide access to casual and business communication as well as collaboration and file transfer capabilities. Programs like Net-Meeting™ and ICQ™, among many others attempt to aggregate these capabilities into a single accessible interface some times integrating separate communications applications for single point launching. Users generally belong to a variety of communities and organizations that may or may not be tightly structured or organized. For example, a user may have family and friends in their on-line address book along with work associates from the job (two communities that should be separated). The same user may belong to a church group and a golf group, or some other sports group. The same user may also volunteer at a wildlife rehabilitation center. However loosely formed and organized, these separate groups often have a central Web presence, for example, a Web site, posting board, or the like. Likewise many of the group members or associates also have individual on-line capabilities like ISP accounts, email addresses and so on. A user associated with more than one group logically has varying personas or faces that he or she presents to each group. Moreover, the user may logically be willing to share only varying degrees and depth of information with these separate groups largely restricted to the subject matter(s) appropriate to the group. For example, the user's family members and close friends would not share the same type and depth of information as the user's work associates, or the user's wildlife rehab associates. It may be desired by a user, and in fact is logical to conclude that in association with these different groups that group boundaries should be respected with reference to communication channels and formal as well as informal information sharing. A drawback to virtually all of the available communication channels whether they are separate channels or integrated into a communication application, is that a user may have to provide a basic permanent identity and profile for these programs to work successfully. For example, an email account generally requires a permanent email address that the user may have to maintain unless the account is to be abandoned. Using more than one email address generally requires more than one email account for a given user. Likewise instant message applications may require a standard email account and identity. Collaborative tools for business like IP telephone, white boarding, and file transfer services similarly boil down to a single user identity, most likely one he or she uses for most communication channels. Therefore, a user wishing to establish boundaries between different activities associated with different groups in a social architecture generally has a daunting organization task of managing communication methods and channels between different members of different groups as well as manually separating contacts within one or more address books or contact lists. It is extremely likely that many times information that was for one group inadvertently becomes available to another group such as an email address and profile or some file or attachment. Communication channels for each group become blurred and any established boundaries between groups tend to deteriorate over time. One mechanism for enabling users to communicate, collaborate, and collect digital content is the well-known Usenet convention. Usenet is a collection of user-submitted notes or messages about various subjects posted to loosely organized servers known as news servers. News servers can be Internet-hosted or hosted on a sub-network accessible through the Internet. These servers operate according to a network protocol termed network News Transfer Protocol or NNTP. Users of Usenet use software applications known as newsreaders that are adapted to enable a user to subscribe to one or more of many hundreds or even thousands of available news groups for the purpose of reading messages posted by other users and posting messages for others to read. Subject matter available for access in a news server is loosely organized under different topics or subjects, referred to collectively as newsgroups. Therefore, for any given newsgroup, there will be hundreds if not thousands of ongoing interactions loosely organized according to a post/response format threading of message headers, posted messages, and posted replies. In some cases newsgroups are moderated so that the headings and posted messages are somewhat in-line with the topic of the group and unwanted content is edited out. A great many newsgroups are completely un-moderated and anonymous. In these groups a user can post any type of message that he or she desires. Whether or not the posting actually fits the general topic is immaterial. Of course, any conceivable topic may be fodder for a newsgroup. Many companies offer moderated newsgroups that cater to their clients or customers wherein the subject matters for the groups are about their offered products. In these types of groups, users often collaborate with each other to resolve problems or issues. More recently, news servers have become repositories for storing binary content in the form of picture files, movie files, game files and other downloadable content. Collectors often subscribe to specific newsgroups through which content that the user wants to collect is posted. While formerly used more for communication and collaboration, Usenet is now used more and more for collection and sharing of binary files and HTTP links to binary files. As Usenet has evolved over the years, so has the software that enables users to partake in the experience. Although most Web browsers and email clients support Usenet, there are especially dedicated programs that enable more efficient sampling, subscribing and manipulation of content from Usenet. The inventors have developed a particular newsreader known in the market as the Agent reader. The Agent reader allows conventional Usenet practices of newsgroup sampling through header sampling; finding and subscribing to newsgroups; finding and subscribing to free newsgroups; posting of messages to newsgroups after subscribing or to free groups; download of binaries; posting of binaries; integration with point-of-presence (POP) and Simple Message Transfer Protocol (SMTP) email accounts. Agent™ also provides database conventions for managing and archiving retrieved content and a search convention for finding specific content within any particular newsgroup. Evolution of Usenet to a more media-heavy, digital collection environment has also invited more undesirable content encountered in the way of Spam messaging, unwanted pop-ups and the like wherein the content matter of the message or binary has nothing even remotely to do with a particular newsgroup topic. In some cases sampling 50 headers of a group returns mostly junk messages that are not topically aligned to the group subject matter. Still, the popularity of Usenet has increased with many attracted to its relative anonymity and loose organization. Communication, collaboration, and collection behaviors are all possible and practiced currently with reference to many programs already mentioned above including newsreaders, peer-to-peer applications, chat software programs, some email clients, and so on. Many users of these applications become overwhelmed when receiving great numbers of messages, sorting through huge address books for contacts, and trying to regulate and manage contacts and downloaded messages and attached files. Most conventions for sorting and filing messages are manual conventions. In other words a user most often than not has to physically create file folders, if those in a list are not sufficient, and manually select and move messages and other content into them. Another drawback in prior-art is that virtually all available applications for communication, collaboration, and collection focus mainly on content management to protect against Spam messages, undesirable downloads or attachments, and other unwanted messages. Content management is handled through user-configured or regulated filters that sort messages, for example, and eliminate those messages found to fit the filter description. Some applications allow you to block messages sent from certain senders based on the sender's identity through a user-created block list or ignore list. Generally speaking though, users must exert much time, effort, and patience to manually configure one or most often more than one application to manage content. Many businesses use a plurality of identities when sending messages to users through email for example. A particular entity may have several different identities relating to differing departments of service, some of which the user would rather not receive messages from. Because the user has a permanent identity when dealing with other on-line entities, his or her identity information and, in some cases behavioral information gets aggregated and sold to other businesses who then begin spamming the user with emails, instant message pop-ups, even faxes and telephone calls if the information is known to them. As previously described, when messages abound in all groups subscribed to and created by any user, the tasks of managing those messages according to which group, which address book, which contact list, which download folder, and so on becomes rather arduous. Most automated mechanisms for management of messages are task intensive and difficult to understand and configure. Lack of understanding complex management tasks that depend on multiple created rules for success renders a user in a state of constant distraction when the number of rules and tasks become more numerous. A user facing many configuration tasks for content and messaging management for more than one medium is more likely than not to revert to manual threadbare techniques. It has occurred to the inventors that in an interface supporting messaging communication, collaboration, and content collection an architecture focused more on message management through user and sender identities would be a far more efficient tool set than what is currently available in the art. Digital collectors also collaborate and communicate to try and locate specific content and to share content with specific others. In the case of Usenet, content authors may be largely anonymous however they do publish their Usenet identities so that other users can respond to them and communicate or collaborate with them. For the most part digital collection in Usenet and other applications is not organized in the sense that a user gets what he or she downloads. In many cases, especially in Usenet environments, there may or may not be thumbnails to sample for picture files or for movie snippets as part of a series description. Moreover descriptions of content depend on the perception of the poster or author and are more likely than not limited to only a few descriptive words or phrases. Digital collections in Usenet comprise basically postings of a series of binary files, for example, a series of pictures, a movie that may be split-up into a series of short clips, or a software utility or game that is posted as a series of downloads split from the whole by a file splitter and compression application such as WinRAR. In many cases there are re-posts of content that is missing some of its pieces or files. A program known as SmartPAR is sometimes used to provide recovery of missing RAR files of a series. Also, there may be different quality versions of a posted series authored by different Posters. In this case it is desirable to be able to locate the best quality version, or the version that may be compatible with a specific user platform or digital player or viewer. Bandwidth and time spent on-line are also issues to contend with. It would be desirable to be able to locate through identity and enhanced content sampling the best digital content from a particular newsgroup without spending a lot of time and bandwidth downloading. Music finder and picture finder applications are available in most readers, but they simply point out the existence of a jpeg or movie file or series. It would be desirable to be able to sample content by locating rich content description elements that fully describe a series and individual elements of a series. Moreover, applying identity management to the task of searching for content can enable a user to locate content based on similar identity profile information between poster and user. One object of the present invention is to provide a user friendly interface for Usenet and other communication channels that will enable a user to manage multiple identities in a way that a correct identity and, in some cases profile is presented when the user is engaged in an interaction within an environment or specific channel that the user approves of for the use of a particular identity. Another object of the present invention is to provide a mechanism for managing incoming communiqués and user contacts based on identities in a way that automatically organizes and prioritizes incoming messages and contact lists according to user approved environments and communication channels. Yet another object of the present invention is to provide a mechanism for managing workflow tasks in coordination with active identities and user environments. Still another object of the present invention is to provide an enhanced content collection experience wherein binary content can be sampled in a more granular and enriched fashion based on author intent and can reflect style and character that can be disseminated by the collector efficiently before accepting or downloading the content. Therefore, what is clearly needed in the art is an enhanced identity oriented communication, collaboration, and enhanced digital collection platform that will manage content, contacts, and communication-based tasks according to preferred user environments, activities, and identities. A platform such as this will perform management duties in the background while the user can concentrate on immediate communication, collaboration, and collection activities. Such a platform will enrich interaction between users and other network-based entities without compromising user-pertinent information for un-solicited use by certain entities. | <SOH> SUMMARY OF THE INVENTION <EOH>The inventor provides a software application for managing routing of communiqués across one or more communication channels supported by a data-packet-network. The application includes one or more workspaces for segregating communication activity; one or more unique user identities assigned per workspace; and one or more contact identities assigned to and approved to communicate with a workspace administrator of the one or more workspaces using the assigned user identities. In a preferred embodiment the application enforces a policy implicitly defined by the existing architecture of the workspaces and associated user and contact identities. In one embodiment the supporting data-packet-network is the Internet network and the one or more workspaces are created zones segregated primarily by genre. In this embodiment a user identity relates to a workspace in terms of a supported communication channel. Also in this embodiment the one or more contact identities include one or more user identities of other users also using an instance of the software application. In a preferred embodiment the zones define user communication parameters for various social environments known to and engaged upon by the user. In this embodiment the routing of a communiqué to a particular workspace is managed by contact identity and user identity pairing, the identities applicable to the supported communication channel used in communication. In one embodiment of the invention the communication channels include email, instant messaging, RSS, and voice channels. In this embodiment the voice channels include voice over Internet protocol and voicemail messages. Also in one embodiment a user identity is one of an email address, a telephone number, a machine address, an IP address, or an Enum address particular to the administrator for a particular workspace and communication channel. In one embodiment of the invention the application may include user alerts generated according to violations of policy. In a preferred embodiment workspaces include at least one inbox for accepting incoming communiqués. In this embodiment workspaces may also include at least one file folder for holding certain content. The certain content may include newsletters received from news groups. In another embodiment content may include binary files collected from a news server. In a preferred embodiment of the invention the communiqués include one or a combination of email messages, voice messages, instant messages, facsimiles, newsletters, chat invitations, instant message invitations, and RSS feeds. In one embodiment one or more user identities per workspace are temporary identities created for correspondence and expiring when no longer needed for correspondence. According to another embodiment of the present invention a firewall is provided for directing handling of communiqués of multiple media types transmitted to a single interface over a data-packet-network according to detected identity information associated with corresponding parties involved. The firewall may include an identity analyzer for analyzing and validating the identities detected; and a directory manager for managing validated identities for future reference. In this embodiment communiqués received at the interface having a sender and a user identification validated as a recognized identity pair are filed in one or more separate workspaces that support the identities detected and validated. In a preferred embodiment the data-packet-network is the Internet network and the one or more workspaces are created zones segregated primarily by genre. In this embodiment an identity is one of a sender identity or a user identity and an identity pair is indicated by the existence of at least one of each for a communiqué. In one embodiment of the present invention the firewall includes a content analyzer for searching content and or attachments of a communiqué for information leading to identification and validation of the sender if the identity analyzer does not detect correct sender identity. In one embodiment the firewall further includes policy violation alerts, which are generated if identity paring cannot be accomplished for a communiqué. According to yet another embodiment of the present invention a method for routing communiqués received at a single interface according to identity information and workspace category is provided including steps (a) creating one or more workspaces to segregate communication; (b) creating one or more user identities for each created workspace; (c) assigning contact identities to certain ones of the created workspaces authorizing those contacts for communication using the workspace; (d) receiving a communiqué; (e) determining the sender and user identities of the communiqué; and (f) filing the communiqué into the appropriate workspace supporting the detected identities. According to one embodiment the single interface is a third-party server. In a preferred embodiment the methods are practiced over the Internet network. In another embodiment with respect to (a) the one or more workspaces are zones administered by a user or a user group. In this embodiment the zones may reflect social or business environments known to and engaged upon by the user. In a preferred embodiment with respect to (b) the user identities are related to communication channels by contact information. In a variation of this embodiment some of the user identities are temporary ad hoc identities. In a preferred embodiment with respect to (c) the contact identities relate to contact parameters of appropriate media types. In this embodiment some contact identities can be applied to more than one workspace. Also in a preferred embodiment with respect to (a) creating a workspace includes creation of one or more inboxes and one or more additional file folders. Also in this embodiment with respect to (d) the communiqué is one of an email, an instant message, a voice call, a voice message, a chat request, a facsimile, or a file transfer. In one embodiment with respect to (d) the communiqué is handled by a media handler according to media type. In still another embodiment a third party hosting service receives the communiqué. In a preferred application with respect to (e) the determination is conducted by an identity analyzer as part of a firewall application. In a variant of this application content analysis is used to help determine the sender identity of the communiqué. Also in this preferred application with respect to (f) a firewall application orders inbound and outbound routing according to identity pairing, the detected pair comprising the sender identity and the user identity. | 20040126 | 20121120 | 20050908 | 62807.0 | 2 | CHEEMA, UMAR | METHODS AND SYSTEM FOR CREATING AND MANAGING IDENTITY ORIENTED NETWORKED COMMUNICATION | SMALL | 0 | ACCEPTED | 2,004 |
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10,765,353 | ACCEPTED | Planetary gear actuator apparatus and method | A traction cable actuator has a sun gear, with a lever, at least two planetary gears engaged with the sun gear, and a housing with a toothed race engaging the planetary gears. The housing further has a lock spring seat, and a traction cable sleeve seat. A drive shaft operatively engages with the sun gear to turn the sun gear. The shaft has at least one release tab. A pulley is disposed within the housing. The pulley has planetary gear axles disposed to receive driving force from the planetary gears. The pulley also has a traction cable wire seat. A lock spring disposed to engage said lock spring seat in the housing engages the lever on the sun gear when the sun gear is turned. The lock spring holds said pulley in a position selected by turning the drive shaft. A bearing and groove stop assembly may be included. | 1. A traction cable actuator comprising: a sun gear, having a lever; at least two planetary gears engaged with said sun gear; a housing having a toothed race engaging said planetary gears, said housing further having a lock spring seat, and said housing further having a traction cable sleeve seat; a drive shaft operatively engaged with said sun gear to turn said sun gear, said shaft having at least one release tab; a pulley disposed within said housing, said pulley having planetary gear axles, said axles being disposed to receive driving force from said planetary gears and said pulley having a traction cable wire seat; a lock spring disposed to engage said lock spring seat in said housing and to engage said lever on said sun gear when said sun gear is turned; whereby, said lock spring holds said pulley in a position selected by turning said drive shaft. 2. The actuator of claim 1 wherein said a gear ratio between said sun gear and said pulley is in the range of about 4.0 to about 4.5 to 1. 3. The actuator of claim 1 wherein said lock spring holds said pulley in position by expanding against said lock spring seat in a frictional engagement, and by a lock spring end abutting said lever of said sun gear. 4. The actuator of claim 1 wherein said release tab is disposed to abut an end of said lock spring such that rotation of said release tab compresses said lock spring in order to release it from a friction engagement with said lock spring seat. 5. The actuator of claim 1 further comprising a positive stop device. 6. An actuator stop for a traction actuation device comprising: a bottom element, said bottom element having a substantially planar top side; a top element, said top element having a substantially planar bottom side; one of said top element or said bottom element being operatively engaged with a force applicator; the other of said top side of said bottom element or said bottom side of said top element being operatively engaged with a force transfer assembly, said force transfer assembly being adapted to transfer force from said force applicator to a traction device; said force transfer assembly having a range of travel; a concavity in one of said top side of said bottom element or said bottom side of said top element; a stopper between said top side of said bottom element and bottom side of said top element, said stopper being disposed to engage said concavity such that movement of said top element and said bottom element relative to one another is stopped, arresting said force transfer, substantially when said force transfer assembly is at an end of said range of travel. 7. The actuator of claim 6 wherein said force transfer assembly is a planetary gear assembly. 8. The actuator of claim 6 wherein said force applicator is manual. 9. The actuator of claim 6 wherein said force applicator is an electric motor. 10. The actuator of claim 6 wherein said traction device is a Bowden cable. 11. The actuator of claim 6 wherein at least one of said top element and said bottom element rotates. 12. The actuator of claim 6 wherein said concavity has length and has ends. 13. The actuator of claim 6 wherein said stopper is a bearing. 14. The actuator of claim 6 wherein said stopper is a convexity in the other of said top side of said bottom element or said bottom side of said top element from said concavity. 15. The actuator of claim 6 wherein said concavity is a groove. 16. The actuator of claim 6 wherein said concavity is a spiral groove. 17. The actuator of claim 6 wherein said concavity is a spiral groove having substantially between 720° and 1,440° of rotation. | CROSS-REFERENCE TO RELATED APPLICATIONS None. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not Applicable. Appendix Not Applicable. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is in the field of mechanical actuators for traction cables, especially as applied to the control of ergonomic supports in seating, particularly automobile seats. 2. Related Art Ergonomic supports for seats, such as automobile seats, need to be adjustable. Movement of the internal components of ergonomic supports, such as lumbar supports, is often made by applying traction to a traction cable such as Bowden cable. The ergonomic supports frequently require the application of traction under some tension to overcome a static bias of a component and/or the weight of the seat occupant, in order to bring the moving parts into an ergonomically weight supporting position for the comfort of the passenger. Traction cables such as Bowden cables are typically comprised of a wire that slides axially through a sleeve. At the lumbar support, the wire will be attached to one portion of a stamped metal or molded plastic pressure surface that is mounted to arch into a supporting position when traction is applied to one or both of its ends. The traction cable sleeve is attached to another portion of the pressure surface, or the mount, to apply the traction. See U.S. Pat. No. 6,254,187, incorporated by reference herein, for examples, of such components. Other components may slide in and out of a channel in a housing, with the sliding being powered by the application of traction through the Bowden cable wire. In such devices, the wire is attached to the moving portion and the sleeve to a housing or mount. See U.S. Pat. No. 6,619,739, incorporated by reference herein, for an example of these components. The present invention may be applied to any moving parts that may be actuated by a traction cable. The mounting of the traction cable on the components of the ergonomic device require that the Bowden cable sleeve end be fixed to a portion of the ergonomic support and the end of the wire that slides through the sleeve be attached to another portion of the ergonomic support. An actuation device mounted at the other end of the traction cable must be able to apply traction to pull the wire through and from the sleeve and also must be able to hold the wire at a selected position along its axial travel relative to the sleeve, in order to thereby hold the connected ergonomic support in a position selected by the user. Power actuators typically achieve these necessary functions by holding the sleeve end in a fixed position and attaching the wire end to a moving part in order to draw it from the sleeve. In some actuators the moving part is an axially translating lead screw, see U.S. patent application Ser. No. 10/008,896, incorporated by reference herein. In other actuators the moving part is a pulley having a seat for a wire end bullet. Turning the pulley thereby pulls the wire from the sleeve. In addition to the necessary functions recited above, there is a variety of traits that are desirable in the marketplace for actuators that apply traction manually. Among these are ease of use and a perception by the user that the components move smoothly. Planetary gears applied to other applications are known. The equilateral symmetry of the drive train is desirable for its mechanical advantage, which promotes ease of use, and for its smooth application of power. However, the planetary gear itself would not be capable of holding a selected position against the tension applied to the traction cable by use of the ergonomic support it is used to actuate. There is a need in the art for a smooth, easy to operate planetary gear mechanical actuator that is capable of holding a selected position. As always, there is a continuing need in the art to produce components that are durable and economical. SUMMARY OF THE INVENTION It is in view of the above problems that the present invention was developed. The present invention is a planetary gear mechanical actuator for a traction cable having a locking spring. A traction cable sleeve is mounted in a stationary position in a housing. The traction cable wire extends from the sleeve and into the housing where it is seated on a pulley. The pulley is rotated by a planetary gear assembly. A sun gear includes a fixed tab, flange or lever. A drive shaft turns the sun gear. The drive shaft also has a tab or boss disposed to articulate with the sun gear flange or lever. The housing has a seat for a locking spring. The ends of the spring are disposed against the lever or flange of the sun gear such that turning the sun gear expands the spring. Expansion of the spring engages a spring seat in the housing in a friction fit, locking the actuator and ergonomic support in a selected position. The tabs on the drive shaft are disposed adjacent to the spring ends in order to compress the spring and release the friction lock when the actuator is turned in a reverse direction. In one embodiment, the locking spring is a circular spring coaxial with the sun gear. In one embodiment, a bearing and groove assembly provide a positive stop to prevent overloading components at the end of a range of travel Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and together with the description, serve to explain the principles of the invention. In the drawings: FIG. 1 is an exploded perspective view of the planetary gear manual actuator of the present invention. FIG. 2 is an assembled, cut away, perspective view of the planetary gear manual actuator of the present invention. FIG. 3 is a perspective view of an assembled actuator. FIG. 4 is an exploded view of an alternative embodiment of the actuator. FIG. 5 is an exploded perspective view of the positive stop feature of the alternative embodiment. FIG. 6 is a perspective view of the positive stop. FIG. 7 is a perspective view of the positive stop. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the accompanying drawings in which like reference numbers indicate like elements, FIGS. 1 and 2 are perspective views of the planetary gear manual actuator of the present invention. FIG. 1 is exploded and FIG. 2 is assembled and cut away. The housing 10 has attached to it or, in the depicted embodiment, integrally formed as a part of it, Bowden cable sleeve seats 12. A key hole slot 14 allows for assembly of the actuator with a traction cable. The interior of the housing includes a toothed race 16. The recess 20 comprises a seat for a locking spring. In the depicted embodiment, the recess is annular. A seat for a pulley is substantially on a plane with the Bowden cable sleeve seats 12 and key hole slots 14. Pulley 30 is dimensioned to fit within the pulley seat in the housing. The pulley has a slot 34 for receiving a traction cable wire (not shown) as the pulley turns to apply traction to the wire. The pulley also has a seat 36 for a traction cable wire end bullet. The faces of this seat will contact the wire end bullet and apply traction to it when the pulley is turned. The pulley also has axles 32 for mounting of planetary gears 40 and for receiving rotational force applied through them. Those with skill in the art will understand that although three planetary gears and planetary gear axles are depicted in this embodiment, any number of planetary gears and planetary gear axles are within the scope of the present invention. Locking spring 50 has a first end 52 and a second end 54, each of which ends have a tab, bent end or other face for engaging other herein described components of the actuator. Locking spring 50 is dimensioned to seat in close cooperation with recess 20 in housing 10 when the spring is in its relaxed state. That is, the dimensions of the spring and recess 20 are such that there is enough room for the spring to rotate, but insufficient room for the spring to expand. The spring may actually touch the housing seat wall 20 when the spring is still relaxed, provided it can turn when not expanded. More particularly, if ends 52 and 54 were forced apart outside the housing, the overall diameter of spring 50 would enlarge. Inside the housing, though, the recess 20 forestalls expansion of the spring 50 diameter. Accordingly, recess 20 also forestalls a movement tending to separate a first spring end 52 from second spring end 54. Sun gear disk 60 includes a sun gear 62 and a lever, flange, tab 64 or other element having at least one face for engaging at least one end (52 and/or 54) of spring 50. Drive shaft 70 includes a hub 72 configured to be assembled with a handle 90 and, in operation, to receive rotational driving force through a users turning of the handle 90. The drive shaft axle 74 proceeds downward and through a central hole 66 in the sun gear disk 60. In the depicted embodiment, drive shaft axle 74 includes a key rail 76 configured to fit into a key slot (not shown) in hole 66 and to apply driving force to sun gear disk 60 via its engagement with sun gear disk hole 66. Drive shaft 70 also has a disk 78. The disk 78 includes first and second and tabs of flanges 80 disposed to straddle lever 64, when assembled, and abut and engage ends 52 and/or 54 of spring 50. The housing top 88 has mounting ears 86 for receiving pins or screws 92. Pins, screws, rivets or other known fixation devices are used to attach the housing top 88 to housing 10 and thereby encapsulate the other operative components within the assembled actuator in functional relationship to one another. In assembly, handle 90 is inserted through a central hole in the housing top 88 to receive its friction fit with drive shaft hub 72. To be assembled with a traction cable, (not shown) the traction cable sleeve is mounted on sleeve seat 12 and the traction cable wire is extended and fit through a key hole slot 14 so that the wire end bullet may be placed in wire end bullet seat 36 such that the wire may be received into pulley slot 34. This is done after assembly of the actuator components 10-90. During assembly with an ergonomic support, traction cable will be mounted on the ergonomic support when the ergonomic support is in a rest position. At the actuator, the Bowden cable wire end bullet will be mounted with both the locking spring 50 and the lumbar support in a rest or untensioned position. The planetary gears 40 are mounted on axles 32 to engage with toothed race 16. Thereafter spring 50 is seated in recess 20. The sun gear disk 60 is installed on top of this assembly so that sun gear 62 engages planetary gears 40. Also, sun gear lever 64 is disposed between the ends 52 and 54 of spring 50. The drive shaft axle 74 is inserted into the sun gear disk 60. The drive shaft disk 78 is disposed such that tabs 80 descend downward into the plane occupied by the sun gear lever 64 and spring 50. Whether aligned by a key (76) or not, tabs 80 straddle the lever 64 and ends 52 and 54 of the spring 50. In this manner, each end 52 and 54 of spring 50 is sandwiched between a side face of lever 64 and one of the tabs 80, in close cooperation with them and with a small amount of tolerance. Assembly is completed by screwing the housing top 80 on the housing bottom 10 and installing lever 90. As can be seen, the actuator as a whole and the traction cable mounting aspects of it are bilateral and symmetrical. Accordingly, the actuator may be used an either right or left handed seating, may be used for differing ergonomic supports on the right or left hand side of the same seat or may for any other reason receive mounting of a single traction cable on either side of housing 10. A unilateral version with only one tab 80 is within the scope of the present invention. In operation, a user will adjust the ergonomic support, for example a lumbar support, from a rest position to a selected position by turning handle 90. Turning handle 90 turns drive shaft 70, which turns sun gear 62. The sun gear's engagement with planetary gears 40 causes them to rotate in an encapsulated path defined by the toothed race 16. Planetary gears 40 will in turn move in a circular path, causing pulley 30 to rotate. The rotation of pulley 30 in a first direction will apply tension to draw a traction cable wire out of a traction cable sleeve, causing a corresponding traction at the other end of the traction cable to actuate an ergonomic support. The depicted embodiment has a gear ratio of 4.3 to 1, whereby the pulley 30 turns once for 4.3 turns of the handle 90. Three handle turns would yield 230° of pulley turn, corresponding to a traction cable range of travel of about 30 to about 50 millimeters, which is a common range of travel for auto seat ergonomic supports. This gear ration imparts a desirable ease of use to the actuator. As the sun gear rotates to bring an ergonomic support into a selected position, the lever 64 and disk 78 rotate. Because the ends 52 and 54 of spring 50 are adjacent to lever 64, the spring 50 will rotate in unison with the sun gear disk 66 and the drive axle disk 78. As rotation continues, tension increases on the traction cable and tends to pull pulley 30 tangentially back towards its original position. When the user releases handle 90, in a selected position, this tractive force on the wire and counter rotational force on the pulley will need to be resisted if the selected position is to be held. After a users release, this force will be transferred through the planetary and sun gears to sun gear disk 66 and its lever 64. This force will be exerted by lever 64 on the spring end closest to the neutral position, which in the depicted embodiment is spring end 52. However, such a force on spring end 52 will tend to cause an expansion of the spring 50. As described earlier, expansion of spring 50 is arrested by the housing wall in circumference around recess 20. The counter rotational force of the wire that expands the spring holds it in a friction fit with the housing seat. The device locks in the selected position. The opposite spring end, 54 in the depicted embodiment, is not also pushed in a counter rotating direction by the tab 80 because a small amount of play or space is dimensioned between them. This space, although remaining quite small, is slightly larger than the amount of circumferential space necessary to move spring 50 into locking engagement with recess wall 20. The locking effect of spring 50's expansion against the recess wall 20 correspondingly holds lever 60 in place and prevents its counter rotation. Accordingly, sun gear 62, planetary gears 40 and pulley 30 are all prevented from counter rotation. Thus, the user selected position is held in place against the tension on the traction wire being exerted in a returning or counter rotational direction. To release the selected position and return to a home position, the drive shaft is turned in the opposite direction. Release tab 80 then closes the small space between itself and spring end 52 or 54, and pushes it. This contracts spring 50, releasing it from locking engagement with spring seat wall 20, so that the spring can counter rotate towards the home position in conjunction with lever 64 and disk 78. FIG. 3 depicts an assembled alternative embodiment of the planetary gear actuator. As can be seen through key hole slot 122 in lower housing part 110, the pulley 130 and its wire end bullet seat 136 are visible and accessible for assembly with a traction cable. The upper housing component 188, has ribbing molded into it for increased strength. FIG. 4 depicts an exploded view of alternative embodiment of the actuator in the present invention. Components 110 through 154, 172, 178, 188 and 190 all correspond to the equivalent components 10 through 54, etc. in FIGS. 1 and 2. Their configuration, assembly, function and operation are the same. Disk 178 also has tabs on its underside for engaging spring end 152 and 154, however from the perspective of FIG. 4 they are obscured by the top of disk 178. FIGS. 4, 5, 6 and 7, also disclose a further novel feature of the present invention. It is a positive stop mechanism comprised of a spiral or helical groove 204 in which is disposed a ball bearing or other traveling component 202. When assembled, bearing 202 is held in groove 204 by the sandwich assembly of disk 178 with a housing top 188. Component 202 may be a convexity in top element 188, on its bottom side. As described above, several turns of the actuator may be required to move an ergonomic support through its entire range of motion, as in most anticipated installations of the present invention. At either terminal end of the ergonomic support's range of motion, continued turning of the handle 190 by a user may lead to unnecessary stress and tension on the components, and possibly an imprecise feel to the users touch. A positive stop incorporated in the actuator itself eliminates those effects. Accordingly, in the depicted embodiment, the number of turns (3) of the spiral groove 204 correspond to the number of turns of the hand crank 190 required to take the ergonomic support anticipated to be actuated by the present invention through its entire range of motion. Other degrees of rotation of the spiral groove, other groove configurations and other ranges of travel are within the scope of the present invention. Such positive stop, when used with a high speed gear train such as the planetary gear, will reduce the load in the gear train. As an example of this protective capacity, the depicted embodiment has a gear ratio between the sun gear and pulley of 4.33 to 1. This means that the torque received at the pulley (30, 130) is 4.33 times that applied to handle (90, 190). For the depicted manual system, the minimal requirement for this torque 8 Nm. The presently depicted planetary gear train would amplify this to 34.64 Nm (4.33 times 8). When the components are made of plastic, that load is sufficient to damage each of the components if applied after the end of a range of travel is reached. The positive stop depicted in FIGS. 4-7, prevents this magnified load from being applied to the subsequent portion of the gear train, and leaves them under the stress of only the ergonomic support, as they are designed to withstand. The positive stop system comprised of bearing 202 and groove 204 in the top surface of disk 178 may also be applied for actuators powered by electric motors. Alternatively, the groove may be in the bottom surface of a top element, e.g. 188, engaged with a top surface of a bottom element, e.g. 178. Again, the effect of these is to reduce the load on the components and increase their durability and prolong their usable lifetime. The positive stop feature may be incorporated with other actuators, especially rotational and/or coaxial pulley type actuators. The stop feature may be used with electric motors used as force actuators. FIG. 6 schematically depicts an electric motor 300 and motor housing and geared transfer assembly 302, which are conventional features in known actuators. In view of the foregoing, it will be seen that the several advantages of the invention are achieved and attained. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention is in the field of mechanical actuators for traction cables, especially as applied to the control of ergonomic supports in seating, particularly automobile seats. 2. Related Art Ergonomic supports for seats, such as automobile seats, need to be adjustable. Movement of the internal components of ergonomic supports, such as lumbar supports, is often made by applying traction to a traction cable such as Bowden cable. The ergonomic supports frequently require the application of traction under some tension to overcome a static bias of a component and/or the weight of the seat occupant, in order to bring the moving parts into an ergonomically weight supporting position for the comfort of the passenger. Traction cables such as Bowden cables are typically comprised of a wire that slides axially through a sleeve. At the lumbar support, the wire will be attached to one portion of a stamped metal or molded plastic pressure surface that is mounted to arch into a supporting position when traction is applied to one or both of its ends. The traction cable sleeve is attached to another portion of the pressure surface, or the mount, to apply the traction. See U.S. Pat. No. 6,254,187, incorporated by reference herein, for examples, of such components. Other components may slide in and out of a channel in a housing, with the sliding being powered by the application of traction through the Bowden cable wire. In such devices, the wire is attached to the moving portion and the sleeve to a housing or mount. See U.S. Pat. No. 6,619,739, incorporated by reference herein, for an example of these components. The present invention may be applied to any moving parts that may be actuated by a traction cable. The mounting of the traction cable on the components of the ergonomic device require that the Bowden cable sleeve end be fixed to a portion of the ergonomic support and the end of the wire that slides through the sleeve be attached to another portion of the ergonomic support. An actuation device mounted at the other end of the traction cable must be able to apply traction to pull the wire through and from the sleeve and also must be able to hold the wire at a selected position along its axial travel relative to the sleeve, in order to thereby hold the connected ergonomic support in a position selected by the user. Power actuators typically achieve these necessary functions by holding the sleeve end in a fixed position and attaching the wire end to a moving part in order to draw it from the sleeve. In some actuators the moving part is an axially translating lead screw, see U.S. patent application Ser. No. 10/008,896, incorporated by reference herein. In other actuators the moving part is a pulley having a seat for a wire end bullet. Turning the pulley thereby pulls the wire from the sleeve. In addition to the necessary functions recited above, there is a variety of traits that are desirable in the marketplace for actuators that apply traction manually. Among these are ease of use and a perception by the user that the components move smoothly. Planetary gears applied to other applications are known. The equilateral symmetry of the drive train is desirable for its mechanical advantage, which promotes ease of use, and for its smooth application of power. However, the planetary gear itself would not be capable of holding a selected position against the tension applied to the traction cable by use of the ergonomic support it is used to actuate. There is a need in the art for a smooth, easy to operate planetary gear mechanical actuator that is capable of holding a selected position. As always, there is a continuing need in the art to produce components that are durable and economical. | <SOH> SUMMARY OF THE INVENTION <EOH>It is in view of the above problems that the present invention was developed. The present invention is a planetary gear mechanical actuator for a traction cable having a locking spring. A traction cable sleeve is mounted in a stationary position in a housing. The traction cable wire extends from the sleeve and into the housing where it is seated on a pulley. The pulley is rotated by a planetary gear assembly. A sun gear includes a fixed tab, flange or lever. A drive shaft turns the sun gear. The drive shaft also has a tab or boss disposed to articulate with the sun gear flange or lever. The housing has a seat for a locking spring. The ends of the spring are disposed against the lever or flange of the sun gear such that turning the sun gear expands the spring. Expansion of the spring engages a spring seat in the housing in a friction fit, locking the actuator and ergonomic support in a selected position. The tabs on the drive shaft are disposed adjacent to the spring ends in order to compress the spring and release the friction lock when the actuator is turned in a reverse direction. In one embodiment, the locking spring is a circular spring coaxial with the sun gear. In one embodiment, a bearing and groove assembly provide a positive stop to prevent overloading components at the end of a range of travel Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings. | 20040127 | 20060214 | 20050728 | 73905.0 | 0 | PANG, ROGER L | PLANETARY GEAR ACTUATOR APPARATUS AND METHOD | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,765,381 | ACCEPTED | Green diode laser | A green diode laser includes a tubular laser casing, a heat sink sealedly mounted at the laser casing, a semiconductor chip supported by the heat sink, an optical resonant cavity supported within the laser casing, including a lasing medium and an intracavity frequency doubler, an IR blocking filter inclinedly and seadedly mounted at the laser casing to optically communicate with an output facet, and a photodiode supported within the laser casing at a position that when the laser beam exits the output facet, the IR blocking filter reflects a portion of the laser beam towards the photodiode such that the photodiode is adapted for detecting the laser beam from the IR blocking filter as a feedback for controlling a power output of the green laser chip. | 1-21. (canceled) 22. A green Diode laser, comprising: a tubular laser casing having a first opening end and a second opening end; a heat sink sealedly mounted at said first opening end of said laser casing; a semiconductor chip supported by said heat sink for emitting a pumping radiation; an optical resonant cavity supported within said laser casing, including a lasing medium to optically communicate with said semiconductor chip for a light amplification of fundamental frequency, and an intracavity frequency doubler to optically communicate with said lasing medium for frequency doubling of said fundamental frequency, wherein an input facet is formed at said lasing medium for said pumping radiation entering thereinto, an output facet is formed at said intracavity frequency doubler for said frequency-double beam exiting therefrom; an IR blocking filter inclinedly and sealedly mounted at said second opening end of said laser casing to optically communicate with said output facet of said intracavity frequency doubler; and a photodiode supported by said heat sink at a position that when said frequency-double beam exits said output facet, said IR blocking filter reflects a portion of said frequency-double beam towards said photodiode such that said photodiode is adapted for detecting said frequency-double beam from said IR blocking filter as a feedback for controlling a power output of said optical resonant cavity. 23. The green diode laser, as recited in claim 22, wherein said lasing medium and said intracavity frequency doubler are combined together, said input facet of said lasing medium is coated with a coating having a high transmissivity at a wavelength of 808 nm and a high reflectance at wavelength of 1064 nm and 532 nm while said output facet of said intracavity frequency doubler is coated with a coating having a high transmissivity at a wavelength of 532 nm and a high reflectance at a wavelength of 1064 nm. 24. The green diode laser, as recited in claim 23, wherein a filter having a high transmissivity at a wavelength of 532 nm and a high reflectance at wavelength of 1064 nm and 808 nm is covered on the light detecting surface of the photodiode. 25. The green diode laser, as recited in claim 24, wherein said intracavity frequency doubler is KTP. 26. The green diode laser, as recited in claim 25, wherein said lasing medium is Nd:YVO4. 27. The green diode laser, as recited in claim 26, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation. 28. The green diode laser, as recited in claim 25, wherein said lasing medium is Nd:GdVO4. 29. The green diode laser, as recited in claim 28, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation. 30. The green diode laser, as recited in claim 23, wherein a light detecting surface of said photodiode is coated with a coating having a high transmissivity at a wavelength of 532 nm and a high reflectance at wavelength of 1064 nm and 808 nm. 31. The green diode laser, as recited in claim 30, wherein said intracavity frequency doubler is KTP. 32. The green diode laser, as recited in claim 31, wherein said lasing medium is Nd:YVO4. 33. The green diode laser, as recited in claim 32, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation. 34. The green diode laser, as recited in claim 31, wherein said lasing medium is Nd:GdVO4. 35. The green diode laser, as recited in claim 34, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation. 36. The green diode laser, as recited in claim 22, wherein said lasing medium and said intracavity frequency doubler are spaced with each other, said input facet of said lasing medium is coated with a coating having a high transmissivity at a wavelength of 808 nm and a high reflectance at wavelength of 1064 nm and 532 nm while a facet of said lasing medium opposite to said input facet is coated with a coating having a high transmissivity at wavelength of 1064 nm and 532 nm, said output facet of said intracavity frequency doubler is coated with a coating having a high transmissivity at a wavelength of 532 nm and a high reflectance at a wavelength of 1064 nm while a facet of said intracavity frequency doubler opposite to said output facet is coated with a coating having a high transmissivity at wavelength of 1064 nm and 532 nm. 37. The green diode laser, as recited in claim 36, wherein a filter having a high transmissivity at a wavelength of 532 nm and a high reflectance at wavelength of 1064 nm and 808 nm is covered on the light detecting surface of the photodiode. 38. The green diode laser, as recited in claim 37, wherein said intracavity frequency doubler is KTP. 39. The green diode laser, as recited in claim 38, wherein said lasing medium is Nd:YVO4. 40. The green diode laser, as recited in claim 39, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation. 41. The green diode laser, as recited in claim 38, wherein said lasing medium is Nd:GdVO4. 42. The green diode laser, as recited in claim 41, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation. 43. The green diode laser, as recited in claim 22, further comprising a Q-switch crystal supported within said laser casing between said lasing medium and said intracavity frequency doubler for converting said laser beam into a pulsed one. 44. The green diode laser, as recited in claim 22, further comprising a single mode device supported within said laser casing between said lasing medium and said intracavity frequency doubler for converting said laser into a single longitude mode laser. | BACKGROUND OF THE PRESENT INVENTION 1. Field of Invention The present invention relates to a diode laser, and more particularly to a green diode laser a volume and a weight thereof are significantly reduced with respect to conventional ones. 2. Description of Related Arts Diode Pumped Solid State (DPSS) lasers have got increasingly popularly used due to their energy efficiency, high reliability, ruggedness, internal blanking and low Total Cost of Ownership (TCO). Their example applications include laser pointer, machining, material processing, spectroscopy, wafer inspection, light show, medical diagnostics and etc. A typical green DPSS laser 9 is as schematically shown in FIGS. 1a and 1b. The green DPSS laser consists of a laser diode assembly 102 having a case 109 containing a pump diode 102. The pump diode 102, powered by a driver circuit providing current therefor, is attached to a heat sink 101 part of which is also contained in the case 109. The pump diode 102 is an infrared (IR) laser diode emitting at 808 nanometer (nm). Laser beam produced by the pump diode 102 passes through an output window defined in the case 109 and a microlens covering on the window. An optical resonant cavity is provided in the path of the laser beam, having a lasing medium 104 and an intracavity frequency doubler 105, either departuring with each other or optically glued together. If the lasing medium 104 and the intracavity frequency doubler 105 are optically glued together, an anti-reflection coating at 808 nm (AR@808) and a high-reflection coating at 532 (HR@532) nm and HR@1064 nm are applied to an input facet facing the pump diode light, and an HR@1064 and an AR@532 are applied to an output facet opposite to the input facet. When the lasing medium 104 and the intracavity frequency doubler 105 are discrete, an AR@808 and an HR@1064 are applied to the input facet of the lasing medium 104, and an AR@1064 to an output facet of the lasing medium 104 opposite to the input facet thereof; while an AR@1064 and an AR@532 to an input facet of the intracavity frequency doubler 105 facing the output facet of the lasing medium 104, and an HR@1064 and an AR@532 to an output facet of the intracavity frequency doubler 105 opposite to the input facet thereof. The lasing medium 104 can be, most often, Nd:YAG or Nd:YVO4, or another crystal that amplifies the input light that passes through it. The intracavity frequency doubler 105 is usually KTP, KDP, LBO, BBO, ADP, LiIO3, or another non-linear material that is able to efficiently produce an output that is twice the frequency of the signal applied to its input. Generally, a focusing optics (also known as “circularizing optics”, must be inserted between the laser diode assembly and the optical resonant cavity for shaping the laser beam from the pump diode as round as possible. An infrared (IR) blocking filter is provided in the path of the laser beam for removing the unwanted IR rays while providing excellent transmission for green wavelength. Optically, an electro-optic crystal (also known as Q-switch, 94) and/or a single mode device can also be inserted between the optical resonant cavity (93) and the IR blocking filter respectively for making the laser into a pulse laser and/or a single longitudinal mode laser. A photodiode is attached in the case of the laser diode assembly for receiving and sensing a reflected laser from the microlens and thus establishing a negative feedback for controlling the optical power output by the pump diode. Up until now, all conventional diode pumped solid state lasers arrange the optical resonant cavity within a small inner barrel placed in front of the laser diode assembly to form an “external” resonant cavity. The focusing optics, the Q-switch, and/or the single mode device are selectively, as needed, attached to the inner barrel and then installed within a diode laser module along with the laser diode assembly. So, it is thought that if the optical resonant cavity, together with other wanted optics, can be put into within the case of the laser diode assembly before the pump diode, the volume and weight of the whole DPSS laser will thus significantly lowered. SUMMARY OF THE PRESENT INVENTION A main object of the present invention is to provide a green diode laser, wherein a volume thereof is substantially smaller than the conventional ones. Another object of the present invention is to provide a green diode laser, wherein a weight thereof is substantially less than the conventional ones. Accordingly, in order to accomplish the above objects, the present invention provides a green diode laser, comprising: a tubular laser casing having a first opening end and a second opening end; a heat sink sealedly mounted at the first opening end of the laser casing; a green laser chip comprising a semiconductor chip supported by the heat sink for producing a laser beam, a lasing medium supported within the laser casing to communicate with the semiconductor chip, and an intracavity frequency doubler mounted to the lasing medium, wherein an input facet is formed at the lasing medium for the laser beam entering thereinto, an output facet is formed at the intracavity frequency doubler for the laser beam exiting therefrom, an optical resonant cavity is defined between the inner and output facets; an IR blocking filter inclinedly and sealedly mounted at the second opening end of the laser casing to optically communicate with the output facet; and a photodiode supported within the laser casing at a position that when the laser beam exits the output fact, the IR blocking filter reflects a portion of the laser beam towards the photodiode such that the photodiode is adapted for detecting the laser beam from the IR blocking filter as a feedback for controlling a power output of the green laser chip. These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B are conventional diode laser. FIGS. 2A and 2B are schematic views of a green diode laser according to a preferred embodiment of the present invention. FIGS. 3A and 3B illustrate a first alternative mode of the green diode laser according to the above preferred embodiment of the present invention. FIG. 4 illustrates a second alternative mode of the green diode laser according to the above preferred embodiment of the present invention. FIG. 5 illustrates a third alternative mode of the green diode laser according to the above preferred embodiment of the present invention. FIG. 6 illustrates a fourth alternative mode of the green diode laser according to the above preferred embodiment of the present invention. FIG. 7 illustrates a fifth alternative mode of the green diode laser according to the above preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 2A and 2B, a green diode laser according to a preferred embodiment of the present invention is illustrated, wherein the green diode laser comprises a tubular laser casing 208 having a first opening end and a second opening end, a heat sink 201 sealedly mounted at the first opening end of the laser casing 208. The green diode laser further comprises a green laser chip (GLC) comprising a semiconductor chip 202 supported by the heat sink 201 for producing a laser beam, a lasing medium 203 supported within the laser casing 208 to communicate with the semiconductor chip 202, and an intracavity frequency doubler 204 mounted to the lasing medium 203, wherein an input facet is formed at the lasing medium for the laser beam entering thereinto, an output facet is formed at the intracavity frequency doubler for the laser beam exiting therefrom as a green laser beam at 532 nm, an optical resonant cavity is defined between the inner and output facets. The green diode laser further comprises an IR blocking filter 205 inclinedly and sealedly mounted at the second opening end of the laser casing 208 to optically communicate with the output facet, and a photodiode 206 supported within the laser casing 208 at a position that when the laser beam exits the output fact, the IR blocking filter 205 reflects a portion of the laser beam towards the photodiode 206 such that the photodiode 206 is adapted for detecting the laser beam from the IR blocking filter 205 as a feedback for controlling a power output of the green laser chip. The lasing medium 203 can be, most often, Nd:YAG or Nd:YVO4, or another crystal that amplifies the input light that passes through it. The intracavity frequency doubler 204 is usually KTP, KDP, LBO, BBO, ADP, LiIO3, or another non-linear material that is able to efficiently produce an output that is twice the frequency of the signal applied to its input. According to the preferred embodiment, a 808 nm anti-reflection layer, a 532 nm high-reflection layer, and a 1064 nm high-reflection layer are respectively coated at the input facet. A 1064 nm high-reflection layer and a 532 nm anti-reflection layer are respectively coated at the output facet. The photodiode 206 has a light detecting surface for receiving the laser beam from the IR blocking filter 205. A 532 nm anti-reflection layer, a 808 nm high-reflection layer, and a 1064 nm high-reflection layer are respectively coated on the light detecting surface of the photodiode 206. Alternatively, a lens filter having a 532 nm anti-reflection ability, a 808 nm high-reflection and a 1064 nm high-reflection ability can be provided at the light detecting surface of the photodiode 206. As shown in FIGS. 3A and 3B, a focusing device 303 is mounted between the semiconductor chip 202 and the input facet for enhancing the laser beam from the semiconductor chip 202. As shown in FIG. 4, a 808 nm anti-reflection layer and a 1064 nm high-reflection layer are respectively coated at the input facet of the lasing medium 203 and a 1064 nm anti-reflection layer is coated at the output facet of the lasing medium 203. A 1064 nm anti-reflection layer and a 532 nm anti-reflection layer are respectively coated at the input facet of the intracavity frequency doubler 204 and a 1064 nm high-reflection layer and a 532 nm anti-reflection layer are respectively coated at the output facet of the intracavity frequency doubler 204. Therefore, when the laser beam from the semiconductor chip 202 enters into the lasing medium 203 as a red laser at 1064 nm, a green laser beam at 532 nm is formed and exited from the lasing medium 203. As shown in FIG. 5, an electro-optic crystal 505, which is also known as Q-switch, is mounted between the semiconductor chip 202 and IR blocking filter 205 within the laser casing 208 for making the laser into a pulse laser. The infrared (IR) blocking filter 206 can be provided in the path of the laser beam closely neighboring a microlens, either within or out of the laser casing 208, for removing the unwanted IR rays while providing excellent transmission for green wavelength. Optically, this IR blocking filter 206 can be dispensed with and the microlens is so made as able to take such a function. As shown in FIG. 6, a single mode device 605 is mounted between the semiconductor chip 202 and the IR blocking filter 205 within the laser casing for converting the laser into a single longitudinal mode laser. As shown in FIG. 7, when the intracavity frequency doubler 204 is omitted, a infrared light at 1064 nm is output. Accordingly, a 808 nm anti-reflection layer and a 1064 nm high-reflection layer are respectively coated at the input facet of the lasing medium 203 while a 1064 nm high-reflection layer is coated at the output facet of the lasing medium 203. In addition, a 1064 nm anti-reflection layer and a 808 nm high reflection layer are respectively coated at the light detecting surface of the photodiode 206. Therefore, the photodiode 206 is adapted for detecting the infrared light from the IR blocking filter 205 as a feedback for controlling a power output of the laser chip. From above disclosure, it could be seen that by installing and supporting the resonant cavity and the necessary optics within the laser casing 208 of an existing green laser chip (GLC), a volume and weight of the present invention will be substantially reduced. One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. It will thus be seen that the objects of the present invention have been fully and effectively accomplished. Its embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims. | <SOH> BACKGROUND OF THE PRESENT INVENTION <EOH>1. Field of Invention The present invention relates to a diode laser, and more particularly to a green diode laser a volume and a weight thereof are significantly reduced with respect to conventional ones. 2. Description of Related Arts Diode Pumped Solid State (DPSS) lasers have got increasingly popularly used due to their energy efficiency, high reliability, ruggedness, internal blanking and low Total Cost of Ownership (TCO). Their example applications include laser pointer, machining, material processing, spectroscopy, wafer inspection, light show, medical diagnostics and etc. A typical green DPSS laser 9 is as schematically shown in FIGS. 1 a and 1 b . The green DPSS laser consists of a laser diode assembly 102 having a case 109 containing a pump diode 102 . The pump diode 102 , powered by a driver circuit providing current therefor, is attached to a heat sink 101 part of which is also contained in the case 109 . The pump diode 102 is an infrared (IR) laser diode emitting at 808 nanometer (nm). Laser beam produced by the pump diode 102 passes through an output window defined in the case 109 and a microlens covering on the window. An optical resonant cavity is provided in the path of the laser beam, having a lasing medium 104 and an intracavity frequency doubler 105 , either departuring with each other or optically glued together. If the lasing medium 104 and the intracavity frequency doubler 105 are optically glued together, an anti-reflection coating at 808 nm (AR@808) and a high-reflection coating at 532 (HR@532) nm and HR@1064 nm are applied to an input facet facing the pump diode light, and an HR@1064 and an AR@532 are applied to an output facet opposite to the input facet. When the lasing medium 104 and the intracavity frequency doubler 105 are discrete, an AR@808 and an HR@1064 are applied to the input facet of the lasing medium 104 , and an AR@1064 to an output facet of the lasing medium 104 opposite to the input facet thereof; while an AR@1064 and an AR@532 to an input facet of the intracavity frequency doubler 105 facing the output facet of the lasing medium 104 , and an HR@1064 and an AR@532 to an output facet of the intracavity frequency doubler 105 opposite to the input facet thereof. The lasing medium 104 can be, most often, Nd:YAG or Nd:YVO 4 , or another crystal that amplifies the input light that passes through it. The intracavity frequency doubler 105 is usually KTP, KDP, LBO, BBO, ADP, LiIO3, or another non-linear material that is able to efficiently produce an output that is twice the frequency of the signal applied to its input. Generally, a focusing optics (also known as “circularizing optics”, must be inserted between the laser diode assembly and the optical resonant cavity for shaping the laser beam from the pump diode as round as possible. An infrared (IR) blocking filter is provided in the path of the laser beam for removing the unwanted IR rays while providing excellent transmission for green wavelength. Optically, an electro-optic crystal (also known as Q-switch, 94 ) and/or a single mode device can also be inserted between the optical resonant cavity ( 93 ) and the IR blocking filter respectively for making the laser into a pulse laser and/or a single longitudinal mode laser. A photodiode is attached in the case of the laser diode assembly for receiving and sensing a reflected laser from the microlens and thus establishing a negative feedback for controlling the optical power output by the pump diode. Up until now, all conventional diode pumped solid state lasers arrange the optical resonant cavity within a small inner barrel placed in front of the laser diode assembly to form an “external” resonant cavity. The focusing optics, the Q-switch, and/or the single mode device are selectively, as needed, attached to the inner barrel and then installed within a diode laser module along with the laser diode assembly. So, it is thought that if the optical resonant cavity, together with other wanted optics, can be put into within the case of the laser diode assembly before the pump diode, the volume and weight of the whole DPSS laser will thus significantly lowered. | <SOH> SUMMARY OF THE PRESENT INVENTION <EOH>A main object of the present invention is to provide a green diode laser, wherein a volume thereof is substantially smaller than the conventional ones. Another object of the present invention is to provide a green diode laser, wherein a weight thereof is substantially less than the conventional ones. Accordingly, in order to accomplish the above objects, the present invention provides a green diode laser, comprising: a tubular laser casing having a first opening end and a second opening end; a heat sink sealedly mounted at the first opening end of the laser casing; a green laser chip comprising a semiconductor chip supported by the heat sink for producing a laser beam, a lasing medium supported within the laser casing to communicate with the semiconductor chip, and an intracavity frequency doubler mounted to the lasing medium, wherein an input facet is formed at the lasing medium for the laser beam entering thereinto, an output facet is formed at the intracavity frequency doubler for the laser beam exiting therefrom, an optical resonant cavity is defined between the inner and output facets; an IR blocking filter inclinedly and sealedly mounted at the second opening end of the laser casing to optically communicate with the output facet; and a photodiode supported within the laser casing at a position that when the laser beam exits the output fact, the IR blocking filter reflects a portion of the laser beam towards the photodiode such that the photodiode is adapted for detecting the laser beam from the IR blocking filter as a feedback for controlling a power output of the green laser chip. These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. | 20040126 | 20060221 | 20050728 | 94870.0 | 0 | VY, HUNG T | GREEN DIODE LASER | SMALL | 0 | ACCEPTED | 2,004 |
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10,765,618 | ACCEPTED | System and method of collecting imaging subject positioning information for x-ray flux control | A system and method of diagnostic imaging is provided that includes positioning a subject in an imaging device, collecting positioning information of the subject from at least one sensor disposed in proximity of the imaging device, and determining a relative position of the subject within the imaging device from at least the position information. The present invention automatically selects a proper attenuation filter configuration, corrects patient centering, and corrects noise prediction errors, thereby increasing dose efficiency and tube output. | 1. A tomographic system comprising: a rotatable gantry having a bore centrally disposed therein; a table movable within the bore and configured to position a subject for tomographic data acquisition within the bore; a high frequency electromagnetic energy projection source positioned within the rotatable gantry and configured to project high frequency electromagnetic energy toward the subject; a detector array disposed within the rotatable gantry and configured to detect high frequency electromagnetic energy projected by the projection source and impinged by the subject; and at least one sensor to provide subject position feedback. 2. The system of claim 1 wherein at least one sensor includes at least one of a laser sensor and a sonic sensor. 3. The system of claim 1 further comprising a computer programmed to: perform at least one scout scan; and associate the subject-position feedback with data derived from the scout scan. 4. The system of claim 3 wherein the computer is further programmed to determine at least one of a projection area (PA), a projection measure (PM), and an oval ratio (OR) from the subject-position feedback and the data derived from the scout scan. 5. The system of claim 3 wherein the computer is further programmed to determine an elevational offset of the subject from the table. 6. The system of claim 3 wherein the computer is further programmed to dynamically control attenuation characteristics of a pre-subject attenuation filter such that the attenuation characteristics match a desired attenuation profile. 7. The system of claim 6 wherein the attenuation profile is determined from the at least one scout scan. 8. The system of claim 1 wherein the position feedback includes subject-contour feedback. 9. A computer readable storage medium having stored thereon a computer program representing a set of instructions which, when executed by at least one processor, cause the at least one processor to: receive feedback regarding a subject position from at least one sensor of an imaging device; and determine a centering error from the feedback. 10. The computer readable storage medium of claim 9 wherein the imaging device includes a medical imaging device. 11. The computer readable storage medium of claim 9 wherein the at least one processor is further caused to determine an adjustment in a table elevation relative to isocenter to reduce the centering error. 12. The computer readable storage medium of claim 9 wherein the at least one processor is further caused to associate the feedback with data received from a scout scan. 13. The computer readable storage medium of claim 9 wherein the at least one processor is further caused to determine at least one of a PA, a PM, and an OR from the subject-contour feedback and the data derived from the scout scan. 14. The computer readable storage medium of claim 9 wherein the sensors include at least one of a laser sensor and a sonic sensor. 15. The computer readable storage medium of claim 9 wherein the at least on processor is further caused to determine a lateral repositioning value for subject recentering from the feedback. 16. The computer readable storage medium of claim 9 wherein the at least on processor is further caused to determine an attenuation profile of an attenuation filter. 17. The computer readable storage medium of claim 16 wherein the at least on processor is further caused to determine an attenuation pattern over a scan duration. 18. The computer readable storage medium of claim 9 wherein the at least on processor is further caused to determine a projection error ratio from the positioning information. 19. A method of imaging comprising the steps of: positioning a subject in an imaging device; collecting positioning information of the subject from at least one sensor disposed in proximity to the imaging device; and determining a relative position of the subject within the imaging device from at least the position information. 20. The method of claim 19 further comprising the step of determining a table elevation relative to isocenter. 21. The method of claim 20 further comprising the step of determining a centering error of the subject in at least one direction. 22. The method of claim 21 further comprising the step of repositioning the subject to reduce the centering error. 23. The method of claim 22 further comprising the step of adjusting table elevation to reduce the centering error. 24. The method of claim 19 wherein the at least one sensor is disposed in a bore of the imaging device. 25. The method of claim 19 further comprising the step of acquiring medical diagnostic data of the subject. 26. The method of claim 19 further comprising the step of detecting a top surface position of the subject from the positioning information. 27. The method of claim 26 further comprising the step of determining from the top surface position an elevational offset of the subject. 28. The method of claim 27 further comprising the step of performing a scout scan. 29. The method of claim 28 further comprising the step of determining the relative position from data acquired during the scout scan. 30. The method of claim 19 wherein the positioning information includes vector position information. 31. The method of claim 19 further comprising the step of adjusting an attenuation characteristic of an attenuation filter according to the determined position of the subject. 32. The method of claim 19 further comprising the step of determining at least one of a PA, a PM, and an OR from the position information. | CROSS-REFERENCE TO RELATED APPLICATION The present invention claims the benefit of U.S. Ser. No. 60/514,711 filed Oct. 27, 2003. BACKGROUND OF THE INVENTION The present invention relates generally to diagnostic imaging and, more particularly, to a method and apparatus to optimize dose efficiency by dynamically filtering radiation emitted toward the subject during radiographic imaging in a manner tailored to the position and/or shape of the subject to be imaged. Typically, in computed tomography (CT) imaging systems, an x-ray source emits a fan-shaped beam toward a subject or object, such as a patient or a piece of luggage. Hereinafter, the terms “subject” and “object” shall include anything capable of being imaged. The beam, after being attenuated by the subject, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-ray beam by the subject. Each detector element of the detector array produces a separate electrical signal indicative of the attenuated beam received by each detector element. The electrical signals are transmitted to a data processing system for analysis and subsequent image reconstruction. There is an increasing desire to reduce radiation expose to a patient during radiographic data acquisition. It is generally well known that significant radiation or “dose” reduction may be achieved by using an attenuation filter to shape the intensity profile of an x-ray beam. Surface dose reductions may be as much as 50% using an attenuation filter. It is also generally known that radiation exposure for data acquisition from different anatomical regions of a patient may be optimized by using specifically shaped attenuation filters tailored to the anatomical region-of-interest (ROI). For example, scanning of the head or a small region of a patient may be optimized using a filter shape that is significantly different than a filter used during data acquisition from the heart. Therefore, it is desirable to have an imaging system with a large number of attenuation filter shapes available to best fit each patient and/or various anatomical ROIs. However, fashioning an imaging system with a sufficient number of attenuation filters to accommodate the numerous patient sizes and shapes that may be encountered can be impractical given the variances in a possible population. Additionally, manufacturing an imaging system with a multitude of attenuation filters would increase the overall manufacturing cost of the imaging system. Further, for optimum dose efficiency, i.e. best image quality at the lowest possible dose, the attenuation profile created by the attenuation filter should be particular to the patient. That is, it is desirable and preferred that when selecting a pre-patient or attenuation filter that it be adjusted according to the particulars of the patient, such as the patient's size, shape, and relative position in the bore of the scanner, be taken into account. By taking these and other particulars into consideration, radiation exposure can be optimized for the patient and the scan session. Known CT scanners use both an attenuation filter and dynamic current modulation to shape the intensity of the x-ray beam incident to the patient. To reduce radiation exposure, the attenuation filer is typically configured to minimize x-ray exposure to edges of the patient where path lengths are shorter and noise in the projection data has a less degrading impact on overall image quality. Accordingly, one such implementation of the attenuation filter is the bowtie filter, which, as a function of form, increases attenuation of x-ray intensity incident upon of the peripheral of the imaging subject. However, improper patient centering and/or bowtie filter selection can significantly degrade image quality and dose efficiency because x-ray attenuation is misapplied to the particulars of the subject. The bowtie filter is aligned with a point of maximum radiation dose or isocenter. The bowtie filter minimizes attenuation of x-ray intensity to isocenter and attenuates radiation significantly with radial distance beyond the center region of the bowtie, because, ideally, the isocenter corresponds to an imaging center of the subject. However, this is not always the case, e.g. when the subject is mis-centered in the scanner. FIG. 1 illustrates a bowtie filter ideally matched to a patient. Specifically, bowtie filter 10 is aligned within an imaging beam 12 such that an x-ray profile 14 is generated by the incidence of the imaging beam 12 upon the patient 16. However, if the patient 16 is not centered with respect to the bowtie center and the corresponding isocenter, significant image degradation can occur. The degradation is dependent upon a multitude of factors, such as the size of the central region of the bowtie filter, size and shape of the patient, and the amount and direction of patient mis-centering. FIG. 2 illustrates one such example of a bowtie filter opening that is improperly matched to the patient. That is, the bowtie filter 10 is aligned within the imaging beam 12 such that an improper x-ray profile 18 is generated by the incidence of the imaging beam 12 upon the patient 16. Specifically, photon incidence or flux at the edges of the patent may increase image noise to a level that may be prohibitively high for diagnostically valuable images. Recent improvements in imaging devices include a continuously adjustable bowtie filter having a pair of filtering elements to compensate for factors that may lead to non-ideal imaging. Such a filter is described in U.S. Ser. No. 10/605,789, the disclosure of which is incorporated herein and is assigned to GE Medical Systems Global Technology Co., LLC, which is also the Assignee of this application. Each filter element has a long low attenuating tail section that varies in attenuation power across its length such that as the elements are moved relative to one another, the attenuation of the beam is controlled. Each filter element is dynamically positioned with a dedicated motor assembly. The filter elements may be positioned in the x-ray beam so as to shape the profile of the x-ray beam to match a desired ROI or anatomical point-of-interest. The filter portions are positionable and adjustable using precision positioners to control the radiation pattern for the patient or the anatomy currently being imaged. However, image degradation may occur if the bowtie opening created is too small for a large patient since useful x-ray needed for imaging is attenuated by the bowtie thereby causing high image noise. As a result, the operator must manually determine the appropriate beam width and position according to size, shape, and positioning of the subject within the scanner bore. A properly sized bowtie configuration, however, does not ensure acceptable image quality. If the subject is mis-centered, image degradation may still persist. This degradation is typically a result of two factors. First, if subject mis-centering is caused by mis-elevation of the subject with respect to the bowtie filter then the calculation of tube current will result in an underestimate of the subject size. Referring to FIG. 3, a patient 16 is shown mis-centered in an x-ray beam 12. Specifically, the patient 16 is positioned at an improper centering elevation 20 by a centering error 22 below a proper centering elevation or y-position 24. As a result, a portion of the imaging beam 26 is not incident upon the patient 16 and a projection area 28 is understated by an error margin 30 because the patient 16 intercepts fewer rays in the imaging beam 12. As such, when determining tube current with the imaging tube at top-dead-center, as is convention, a lower tube current than actually required for proper imaging will be determined. As a result of the lower tube current, excessive image noise will be present relative to the user's selection. For example, a calculated milliamp (mA) that is 30% lower than actually required for proper imaging occurs for a typical 30 cm×20 cm body mis-centered in elevation by three cm. In such a case, noise introduction is increased by approximately 15% from a properly centered, properly imaged, patient. Secondly, patient mis-centering with respect to elevation may also position the thickest part of the patient such that x-rays for lateral projections pass through the thickest part of the bowtie which results in over-attenuation of the imaging beam. Referring to FIG. 4, the patient 16 is shown mis-centered within the imaging beam 12 by a centering error 22 below the proper centering elevation 24. As a result, the imaging beam 12 passes through the thickest parts of the bowtie filter 10 and patient 16, as exemplified by projection route 32. Such mis-centering can result in an additional image noise increase by as much as 70%. These errors can cause images of such high noise that the diagnostic value is compromised. Moreover, since traditional CT imaging methods rely on operator input to perfect patient centering, including elevation, elevational patient mis-centering can be common. Furthermore, traditional edge detection methods rely on identifying the center of the patient indirectly by detecting the edges of the patient, which can be particularly susceptible to error. Additionally, recent advancements in detector technology has increased the desire to control x-ray flux management to within very accurate constraints. For example, photon counting (PC) and energy discriminating (ED) detector CT systems have the potential to greatly increase the medical benefits of CT by differentiating materials such as a contrast agent in the blood and calcifications that may otherwise be indistinguishable in traditional CT systems. Additionally, PC and ED CT systems produce less image noise for the same dose than photon energy integrating detectors and hence can be more dose efficient than conventional CT systems. However, while PC and ED CT systems have the potential to realize numerous advantages over traditional CT detectors, the systems may be impractical for some scan protocols. Therefore, it would be desirable to design an apparatus and method to automatically control flux by dynamically filtering radiation emitted toward the subject during radiographic imaging in a manner tailored to the position and/or shape of the subject to be imaged so as to optimize radiation exposure during data acquisition. It would be further desirable to have a system that tailors the radiation emitted toward the subject during data acquisition based on a scout scan of the subject. Furthermore, it would be advantageous to have a system and method of controlling x-ray flux management to avoid photon pileup. Additionally, it would be desirable to have a system and method of dynamically adjusting radiation filtering to follow a user defined-region-of interest. It would also be desirable to have an apparatus to automatically collect patient centering and surface elevation information include a direct method of detecting patient centering. Furthermore, it would be desirable to have a method of accurately determining patient mis-centering within an imaging volume and adjusting the patient position to compensate for the determined mis-centering. BRIEF DESCRIPTION OF THE INVENTION The present invention is a directed method and apparatus to optimize radiation exposure that overcomes the aforementioned drawbacks. The present invention includes a method and apparatus for collecting imaging subject positioning information and automatically controlling an x-ray dose to be tailored to the position of the imaging subject. In accordance with one aspect of the invention, a tomographic system is disclosed that includes a rotatable gantry having a bore centrally disposed therein, a table movable within the bore and configured to position a subject for tomographic data acquisition within the bore, and a high frequency electromagnetic energy projection source positioned within the rotatable gantry and configured to project high frequency electromagnetic energy toward the subject. A detector array is disposed within the rotatable gantry and configured to detect high frequency electromagnetic energy projected by the projection source and impinged by the subject and at least one sensor is included to provide subject position feedback. In accordance with another aspect of the invention, a computer readable storage medium is disclosed having stored thereon a computer program representing a set of instructions. When the instructions are executed by at least one processor, the at least one processor is caused to receive feedback regarding a subject position from at least one sensor of an imaging device and determine a centering error from the feedback. In accordance with another aspect of the invention, a method of imaging is disclosed that includes positioning a subject in an imaging device, collecting positioning information of the subject from at least one sensor disposed in proximity of the imaging device, and determining a relative position of the subject within the imaging device from at least the position information. Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention. In the drawings: FIG. 1 is a schematic view of a properly aligned attenuation filter assembly and a resulting x-ray profile. FIG. 2 is a schematic view of an improperly aligned attenuation filter assembly and a resulting x-ray profile. FIG. 3 is a schematic view of an improperly centered patient within an imaging beam and a resulting projection area. FIG. 4 is a schematic view of an improperly centered patient within an imaging beam. FIG. 5 is a pictorial view of a CT imaging system. FIG. 6 is a block schematic diagram of the system illustrated in FIG. 5. FIG. 7 is a plan view of a representative x-ray system. FIG. 8 is a sectional view of a portion of the x-ray system shown in FIG. 5. FIG. 9 is a flow chart showing a process in accordance with the present invention that may be implemented with systems of FIGS. 5-8. FIG. 10 is a schematic view of an attenuation filter assembly with an improperly centered patient and the resulting flux profile. FIG. 11 is a flow chart showing a process for selecting an attenuation filter configuration and tube current modulation scheme utilizing AP and lateral scout scans. FIG. 12 is a graph of a set of optimum bowtie opening values derived from patient size. FIG. 13 is a graph of a quality factor versus attenuation filter opening for a plurality of patient sizes. FIG. 14 is an illustration of a lateral scout scan showing an improperly centered patient. FIG. 15 is an illustration of a user-defined ROI by placement of reference markers on an interface in accordance with one aspect of the present invention. FIG. 16 is a flow chart showing a process for selecting an attenuation filter configuration and tube current modulation scheme utilizing a lateral scout scan. FIG. 17 is a flow chart showing a process for selecting an attenuation filter configuration and tube current modulation scheme utilizing an AP scout scan. FIG. 18 is an illustration of surface elevation derivation with known patient height data in accordance with the present invention. FIG. 19 is an illustration of surface elevation derivation with unknown patient height data in accordance with the present invention. FIG. 20 is a schematic view of a sensor assembly incorporated into an imaging scanner for derivation of patient surface elevation. FIG. 21 is a pictorial view of a CT system for use with a non-invasive package inspection system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is directed to a method and system that automatically determines the patient's size, shape, and centering within an imaging volume and dynamically controls x-ray flux accordingly. Preferably, one or two scout scans together with a plurality of sensors integrally formed with the CT scanner provide patient particulars. The present invention uses the information to provide centering information to the user, allow user input, automatically re-center the patient elevation, correct projection area measurements for dynamic tube current control and select the correct bowtie filter for the optimum dose efficiency. The operating environment of the present invention is described with respect to a four-slice computed tomography (CT) system. However, it will be appreciated by those skilled in the art that the present invention is equally applicable for use with single-slice or other multi-slice configurations. Moreover, the present invention will be described with respect to the detection and conversion of x-rays. However, one skilled in the art will further appreciate that the present invention is equally applicable for the detection and conversion of other high frequency electromagnetic energy. The present invention will be described with respect to “third generation” CT systems but is equally applicable with a wide variety of CT systems. That is, it is contemplated that the present invention may be utilized with energy integrating, photon counting (PC), and/or photon energy discriminating (ED) CT detector systems. Specifically, it should be recognized that the present invention provides a technique that controls and effectively limits detector saturation. The technique is adaptable such that it may be tailored to specific the requirements and constraints of a particular detector type and/or detector arrangement. For example, energy integrating detectors, which integrate the amount of x-ray flux recorded during an exposure time, have an inherent flux level tolerance that is relatively high. On the other hand, direct conversion detectors such as photon counting detectors, which actually count each photon as it passes, have a very different, typically lower, flux level tolerance. The present invention provides a dynamically adaptable technique whereby specific flux level tolerances may be observed to avoid detector saturation. Referring to FIGS. 5 and 6, a computed tomography (CT) imaging system 100 is shown as including a gantry 102 representative of a “third generation” CT scanner. Gantry 102 has an x-ray source 104 that projects a beam of x-rays 106 through a filter assembly 105 toward a detector array 108 on the opposite side of the gantry 102. Detector array 108 is formed by a plurality of detectors 110 which together sense the projected x-rays that pass through a medical patient 112. Each detector 110 produces an electrical signal that represents the intensity of an impinging x-ray beam and hence the attenuated beam as it passes through the patient 112. Moreover, the detectors may be photon energy integrating detectors, photon counting, and photon energy discriminating detectors. During a scan to acquire x-ray projection data, gantry 102 and the components mounted thereon rotate about a center of rotation 114. Rotation of gantry 102 and the operation of x-ray source 104 are governed by a control mechanism 116 of CT system 100. Control mechanism 116 includes an x-ray controller 118 that provides power and timing signals to an x-ray source 104, a gantry motor controller 120 that controls the rotational speed and position of gantry 102, and filter assembly controller 123 that controls filter assembly 105. A data acquisition system (DAS) 122 in control mechanism 116 samples analog data from detectors 110 and converts the data to digital signals for subsequent processing. An image reconstructor 124 receives sampled and digitized x-ray data from DAS 122 and performs high speed reconstruction. The reconstructed image is applied as an input to a computer 126 which stores the image in a mass storage device 128. Computer 126 also receives commands and scanning parameters from an operator via console 130 that has a user interface device. An associated cathode ray tube display 132 allows the operator to observe the reconstructed image and other data from computer 126. The operator supplied commands and parameters are used by computer 126 to provide control signals and information to DAS 122, x-ray controller 118 and gantry motor controller 120. In addition, computer 126 operates a table motor/table centering controller 134 which controls a motorized table 136 to position patient 112 and gantry 102. Particularly, table motor/table centering controller 134 adjusts table 136 to move portions of patient 112 through and center patient 112 in a gantry opening 138. Sensors 140 are positioned within gantry opening 138 to collect patient position and contour data. Sensors 140 are connected to a sensor controller 142 that controls the operation of sensors 140 and provides the acquired data to computer 126 to be processed. As shown in FIGS. 7 and 8, an x-ray system 150 incorporating the present invention is shown. The x-ray system 150 includes an oil pump 152, an anode end 154, and a cathode end 156. A central enclosure 158 is provided and positioned between the anode end 154 and the cathode end 156. Housed within the central enclosure 158 is an x-ray generating device or x-ray tube 160. A fluid chamber 162 is provided and housed within a lead lined casing 164. Fluid chamber 162 is typically filled with coolant 166 that will be-used to dissipate heat within the x-ray generating device 160. Coolant 166 is typically a dielectric oil, but other coolants including air may be implemented. Oil pump 152 circulates the coolant through the x-ray system 150 to cool the x-ray generating device 160 and to insulate casing 164 from high electrical charges found within vacuum vessel 168. To cool the coolant to proper temperatures, a radiator 170 is provided and positioned at one side of the central enclosure 158. Additionally, fans 172, 174 may be mounted near the radiator 170 to provide cooling air flow over the radiator 170 as the dielectric oil circulates therethrough. Electrical connections are provided in anode receptacle 176 and cathode receptacle 178 that allow electrons 179 to flow through the x-ray system 150. Casing 164 is typically formed of an aluminum-based material and lined with lead to prevent stray x-ray emissions. A stator 170 is also provided adjacent to vacuum vessel 168 and within the casing 164. A window 182 is provided that allows for x-ray emissions created within the system 150 to exit the system and be projected toward an object, such as, a medical patient for diagnostic imaging. Typically, window 182 is formed in casing 164. Casing 164 is designed such that most generated x-rays 184 are blocked from emission except through window 182. X-ray system 150 includes an attenuation filter assembly 186 designed to control an attenuation profile of x-rays 184. As stated, the present invention provides a means to determine patient particulars such as patient size, shape, and centering from one or two scout scans. The information is used to provide centering information to the user, allow user selection of a ROI, automatically center the patient elevation, correct projection area measurements for dynamic tube current control, and select the correct bowtie filter configuration for the optimum dose efficiency. The methods include automatic selection of the proper bowtie filter opening to control the impact of the bowtie filter and patient mis-centering on tube current or x-ray flux modulation. Referring now to FIG. 9, a flow chart setting forth the steps of an imaging technique in accordance with the present invention is shown. The technique is particularly tailored for dynamic bowtie and tube current control. The technique begins at 200 with the performance of at least one scout scan and/or sensing a patient elevational profile 202 to determine a required tube current modulation 204 in the x, y and z-directions for a desired image noise assuming a properly centered patient. As will be described in detail, the scout scan(s) may be a lateral scout scan or an anterior-posterior (AP) or posterior-anterior (PA) scout scan. Depending on the orientation of the available scout scan(s), a starting CT scan angle, a location in the z-direction, and positions for the left and right filter segments of the continuously variable bowtie filter, such as that described in commonly assigned patent application U.S. Ser. No. 10/605,789, are selected 206. The starting bowtie (attenuation) filter positions are determined 206 independently for each side, as will be described with respect to FIG. 10. Once the starting bowtie filter positions have been set 206, scanning begins 208. Bowtie position information is collected and included for each projection during the scan to allow the bowtie attenuation profile to be properly normalized during image reconstruction. Bowtie positioning repeatability is preferably maintained within ten micrometers to allow dynamic calibration and correction of the moving bowtie during patient scanning. That is, during the scan 208 the information from the scout scan(s) and/or sensed patient elevational profile 202 is/are used to adjust operating parameters. Specifically, a maximum edge x-ray flux is sensed 210 and a closed loop feedback system is utilized to determine whether such is within a select range 212. If it is determined that the maximum edge x-ray flux is outside the selected range 214, the bowtie filter is adjusted to maintain the maximum edge x-ray flux 216. That is, as the maximum flux at the edge of the imaging object increases, an associated filter segment of the bowtie filter is moved toward isocenter. Conversely, if the flux at the edge relative to the center flux is below the selected range, an associated filter segment of the bowtie filter is moved away from isocenter. However, if it is determined that the maximum edge x-ray flux is inside the selected range 218, the bowtie filter is not adjusted and sensing of the maximum edge x-ray flux continues. At the same time, a mean x-ray flux rate at the central portion of the imaging subject is sensed 220 and a determination of whether the mean x-ray flux rate at the central portion of the imaging subject is outside a selected range is made at 222. If the mean x-ray flux rate at the central portion of the imaging subject is outside the selected range 224, the tube current (mA) is adjusted to maintain the desired mean x-ray flux rate in the central projection region of the imaging subject 226. On the other hand, if the mean flux rate at the central portion of the imaging subject is within the selected range 228, no change to tube current is made and sensing 220 continues. However, since mA modulation influences the edge flux, it is contemplated that the control of edge flux levels may be done relative to the average central flux level. As such, in accordance with one embodiment of the present invention, the adjustment of bowtie filter toward isocenter 216 and the adjustment of tube current 226 are based on an interdependent consideration of both the sensed maximum flux at the edge of the imaging object 210 and the sensed mean flux rate at the central portion of the imaging object 210. Furthermore, as will be described, it is contemplated to use a priori positioning for dynamic bowtie positioning with the feedback loop and to use filter positioning moves to prevent photon pileup only when absolute flux limitations are at risk thereby also compensating for the fact that mA modulation influences the edge flux. In this way, the bowtie filter can be positioned for optimum dose efficiency based on imaging subject size, shape, and centering as a first priority whereby positioning for prevention of photon pileup during scanning has precedence. However, it is contemplated that for situations where the central projection region may have the highest x-ray flux, such as for AP projections when scanning legs, for example, adjusting the mA to avoid photon pileup in the center of the projections may be given priority over the tube current modulation objectives. As will be shown, reliable patient size and centering determinations can be made from projections using two orthogonal scout scans or a single scout scan. However, as will be shown, the present invention includes systems to compensate for the absence of a second scout scan by accurately sensing patient elevational contours. The present invention also includes a method of improved calculations of subject center whereby the centroid (center of mass) is determined from two orthogonal scout projections or estimated from a single scout scan. The method of FIG. 9 may be utilized to maintain the x-ray flux rates below an absolute maximum limit of a detector. That is, x-ray rates for some detector configurations may be significantly lower than other detectors. Hence, flux rates must be carefully managed to avoid count rate saturation (photon pileup). Since patient attenuation, projection centering error, and desired flux rate levels are known; x-ray flux rates can be controlled by appropriate filter positioning and tube current adjustments using expressions representing the fundamental x-ray physics attenuation and absorption equations. Referring now to FIG. 10, an example of a patient mis-centering to the left is illustrated 230. That is, the patient 232 is mis-centered with respect to the isocenter 234 of the x-ray flux passing through a bowtie filter configuration 236. The bowtie filter configuration 236 includes a left bowtie portion 238 and a right bowtie portion 240 that are dynamically adjustable by left control motor 242 and right control motor 244. The bowtie configuration and the tube current are controlled such that a central patient region 246 is within a desired object flux 248 according to a desired image noise. Furthermore, the left bowtie portion 238 is positioned to maintain a left patient edge region flux profile 250 below a max flux limit 252. Similarly, the right bowtie portion 240 is positioned to maintain a right patient edge region flux profile 254 below the max flux limit 252. Accordingly, a filter and patient x-ray flux profile 256 has a relative flux level 258 below the max flux limit 252. As such, flux rates are maintained to remain under the x-ray rates required for specific detector configurations, thereby avoiding photon pileup. Specifically, the system may be used to overcome limitations, such as photon pileup, which is commonly encountered with the use of photon counting (PC) and photon energy discriminating detectors (ED) CT as opposed to traditional photon energy integrating CT detectors. Photon counting CT systems include detector systems that are capable of distinguishing between photons such that a photon is differentiated from another photon and counted as it is received by the detector. Energy discriminating CT systems are capable of tagging each photon count with its associated energy level. As will be described in detail below, the present invention provides a means to determine an imaging subject's size, shape, and centering and to use this information to provide centering information for automatically re-center patient elevation. Accordingly, as shown in FIG. 10, x-ray flux management may be controlled to maintain a flux profile 250, 254 that is below a max flux limit 252 of a specific detector and its respective flux limits. For example, the flux profile 250, 254 may be specifically controlled to satisfy the requirements of ED or PC CT detectors so as to avoid photon pileup. Referring now to FIG. 11, FIG. 11 provides a detailed method for adjusting pre-imaging and imaging parameters. Specifically, two scout scans are performed 300 that include an AP scout scan and a lateral scout scan. From the two scout scans a centroid projection 302 is made. Specifically, the distance of the centroid from a point of reference is made. In a preferred embodiment, the point of reference is isocenter of the x-ray fan beam and the distance of the centroid from isocenter is determined. However, it is also contemplated that the point of reference may be the center of the medical imaging device or the center of the bore of the medical imaging device, or any other stationary point that is readily identifiable. Additionally, it is contemplated that the point of reference may be a map of an ideally positioned imaging subject with similar physical features. In any case, the distance of the centroid from the point of reference is used to geometrically calculate an x and y centering error for the patient relative to a reference position 304. In accordance with a preferred embodiment of the present invention, the reference position is at a center of the scanning bay located in the y-direction. However, it is also contemplated that the reference position may be arbitrarily selected as long as the reference position is fixed with respect to patient position within the CT bore. Having calculated the y-axis patient centering error over the extent of the prescribed CT scan, the system determines the mean center with respect to the reference position, to provide the optimum fixed table height for the duration of the CT scan. The x and y mis-centering is then compared to a threshold 305. Accordingly, a direct determination of the center of the imaging subject is made. That is, by utilizing centroid calculations the center of maximum attenuation that should be positioned in the maximum x-ray field is determined rather than the physical center relative to the edges of the object. If the mis-centering is less than the threshold 306, indicating that the current position of the patient is within the imaging tolerance of the system, no adjustment is necessary and the system is ready for scanning 307. However, if the mis-centering is greater than the threshold 308, the operator is notified of the centering error 309 and presented with an auto-correction prompt whereby the operator is prompted to accept or reject 310 the table elevation change. However, it is contemplated that operator approval may be bypassed whereby auto-correction is completed without operator approval 310. As such, a fully automated correction system may be implemented. As will be described with respect to FIGS. 11 and 12, should the operator reject the auto-correction 311, the operator may use a graphical indication or other means to enter a user-selected centering correction 312 according to which scanning is performed 313. Should the operator accept the auto-correction 314, the patient elevation is automatically corrected 316. Additionally, the x and y centering errors are used to correct the projection area (PA) 318. The PA is the sum of the attenuation values of the x-rays that intercept the patient. Therefore, PA is dependent on the distance of the patient from the fan beam x-ray source. By utilizing the accuracy of the centroid calculated x and y centering errors, a corrected PA is directly calculated using geometric equations 318. The PA from both the AP and lateral scouts can be corrected using the centering error determined from the orthogonal scout scan and the average AP scout scan. That is, lateral PA can be used to improve the accuracy of a tube current modulation noise prediction algorithm 322. Additionally, the oval ratio (OR) is directly computed 320 using the projection measure (PM) ratio from the two orthogonal scouts to further improve the accuracy of the tube current modulation noise prediction 322. That is, the tube current is then boosted to compensate for the centroid calculated mis-centering 324. Once adjustments according to the centroid calculated mis-centering are complete 316-324, the proper bowtie filter configuration is selected 326. Specifically, for a given bowtie filter shape and a given patient size and shape there exists an optimum opening, measured in flat width (FW), that provides the best image quality at the lowest dose. The optimum value is the value of FW that maximizes a quality factor Q as calculated as follows: Q = KC ( a , b , FW ) N ( a , b , FW ) D ( a , b , FW ) ; where: N is the overall noise in the image or scan data (standard deviation); D is the dose to the object; C is the contrast between two materials such as iodine and water (dependent on the spectral characteristics of the system); K interpolates linearly between Q = 1 N 2 D and Q = C N 2 D ; a and b are the axes parameters for an ellipse; and FW is one half of the flat width (i.e. ½ the length of the uniform low attenuation region of the bowtie filter in mm). In accordance with an alternative embodiment, quality factor may be determined using a single diameter parameter d, where d is the average of a and b. In either case, once the proper bowtie filter configuration is selected 226, the system is ready for scanning 328. As such, the patient table is raised or lowered dynamically during the execution of a helical CT scan to accommodate the changing optimum elevations depending on patient anatomy and centering/mis-centering. Elevation data is included in the scan data header to properly position the views during image reconstruction. If a continuous bowtie is present, the bowtie is positioned dynamically to follow the sineogram of the patient. That is, an attenuation pattern may be utilized that maps a dynamic configuration of the attenuation of the bowtie so as to achieve desired attenuation over time, i.e. during data acquisition. Referring now to FIG. 12, the optimum bowtie filter opening can be determined experimentally by constructing various phantom sizes and shapes and then scanning the phantoms with various bowtie filters having different FW values, reconstructing images, measuring the noise, dose, and contrast for each case, and fitting a curve to the Q values vs. FW as shown in FIG. 13. The optimum FW value for a given patient size can then be determined by reviewing FW value against the Q value. Specifically, the FW value where Q is at a maximum is the optimum FW value, as illustrated in FIG. 13. The Q values can also be determined by computer modeling using fundamental x-ray physics attenuation and absorption equations to estimate the noise, contrast, and dose in the image for each case. The contrast weighting value K can be chosen between 0 and 1. In the given example, the value of K is zero in order to exclude any benefits of improved object contrast. From experimental data or simulations the set of optimum bowtie opening values can be determined versus patient or object size as shown in FIG. 12. The relationship is approximately linear and can be represented by the equation FW=0.45 (d-10) for the K=0 assumption where d is the patient diameter in centimeters. Patients with diameters less than 10 cm would use a bowtie opening FW value of zero. As such, optimum bowtie opening FW can be accurately selected given the patient diameter d. The patient diameter can be determined from the PM (amplitude of projection) and a patient density assumption μ. The average PM can be obtained from the orthogonal scout scan pair since d=avg(PM/μ). For the human body, the density assumption μ can be assumed to be 0.2, which is the attenuation coefficient of water, except for the chest and head. For the chest and head, μ can be approximated as 0.14 and 0.24, respectively, due to the density decrease of the lungs and the density increase of the skull. For CT systems with a continuously variable addressable bowtie, the FW value can be determined directly by the equation, d=avg(PM/μ). On CT systems without an addressable continuous bowtie, the equation can be used to select the nearest optimum bowtie from the selection of available discrete bowtie filters. For example a set of discrete bowtie filters that covers the patient range from infants to large obese adults would typically include bowtie filters with openings having FW values of 1, 5, 9, and a flat filter. From the graph on FIG. 12, the following lookup table can be constructed to automatically select the most optimum discrete bowtie for the patient as follows: DIAMETER: <15 cm 15 to 25 cm >25 to 35 cm >35 cm BOWTIE FILTER: FW 1 FW 5 FW 9 Flat The optimum filter opening, however, is dependent on how well the patient is centered in addition to the patient's diameter. The effect of patient mis-centering is comparable to a patient radius increase for the projections perpendicular to the mis-centering axis. Hence the proper filter selection is a function of the patient diameter plus the mis-centering and can be determined using the equation, FW=0.45 (d−10+2ew), where e is the patient mis-centering error in centimeters and w is a weighting factor or function. The weighting factor is typically 1.0 but could be less than 1.0 to constrain the dose increase that would otherwise result when the bowtie is opened to fully account for the worst case effect of mis-centering. The value of w could also be a function of the object size, shape, and mis-centering to more closely match the behavior of image noise with mis-centering of various size objects. A discrete bowtie selection can also be obtained by adding the centering error factor (2ew) to the phantom diameter for the lookup table index. For example, from the table, a 24 cm patient with a 3 cm error would be considered a 30 cm diameter and hence, filter FW 9 should be selected instead of FW 5 for the centered case. Furthermore, in the event that tube current modulation is used and the patient is mis-centered in a smaller than optimum bowtie, the mA can be boosted to avoid an unacceptable noise increase in the image. Referring now to FIG. 14, an example of the user interface through which manual entry of a user-selected centering correction 312, FIG. 11, may be entered is shown. In the given example, the user is performing a spine study. In this case, a spine study is optimally centered on the spine 410 instead of the overall attenuation centroid for the patient 412. However, the automatically calculated adjustments will be based upon the mean center of the patient over the scan length and yield the overall attenuation centroid of the patient as the center point 412. Accordingly, the automatically calculated adjustments based on the centroid calculations to compensate for mis-centering are not optimal for the spine study and the operator will choose to manually enter a user-selected centering correction such that recentering is along the mean center of the spine over the scan length 414. Referring to FIG. 15, another view of the example of the user interface through which manual entry of a user-selected centering correction may be entered on a pair of scout scans is shown. Through the interface, the user marks the location of the spine or other area of interest on scout scans using cursor markers 416. Via the user-defined cursor markers 416, a diameter of interest 418 is defined that includes a center of interest 420 independent of the centroid calculated isocenter 422. Accordingly, the patient table may be raised or lowered dynamically during the execution of a CT scan to accommodate the changing optimum elevations depending on patient anatomy to track the user-defined cursor markers. Elevation data is included in the scan data header to properly position the views during image reconstruction. If a continuous bowtie filter is present, the bowtie filter may be controlled dynamically to follow the sineogram of the patient. That is, if the location of a ROI is designated 418 via markers 416, the bowtie filter is dynamically positioned to follow the sineogram of the ROI. This positioning obtains improved image quality for the ROI and reduces dose elsewhere. FIG. 16 illustrates an implementation of the method illustrated in FIG. 11 when only a lateral patient scout scan 510 is available. From the lateral scout scan 510, a centroid projection is made at 512 and y mis-centering is determined relative to a reference position 514 according to the methods previously described. However, since no AP scout scan data is available, x mis-centering is assumed to be zero. The assumption that x mis-centering is 0 provides a reasonable estimation as long as the operator utilizes the edges of the patient table as a guide when positioning the patient in x. Then, having determined the y axis patient centering error over the extent of the prescribed CT scan, the system determines the mean center to provide the optimum fixed table height for the duration of the CT scan. The y mis-centering is then compared to a threshold 516. If the mis-centering is less than the threshold 518, indicating that the current position of the patient is within the imaging tolerance of the system, no adjustment is necessary and the system is ready for scanning 520. However, if the mis-centering is greater than the threshold 522, the operator is notified of the centering error 524 and presented with an auto-correction prompt whereby the operator is prompted to accept or reject 526 the table elevation change. However, it is contemplated that operator approval may be bypassed whereby auto-correction is completed without operator approval 526. As was described with respect to FIGS. 11 and 12, should the operator reject the auto-correction 528, the operator may use a graphical indication or other means to enter a user-selected centering correction 530 according to which scanning is performed 532. Should the operator accept the auto-correction 534, the patient elevation is automatically corrected 536. The PA, PM, and OR are calculated 538-540 from the single scout using known methods utilizing y mis-centering calculations. However, since only one PM is available from the single scout scan, the diameter for bowtie selection is determined by the equation, d=(PM/μ)(OR+1)/2 because the OR, by definition, is the ratio of the axis parameters of the elliptical patient model. As such, mA modulation is calculated 542, the mA boost factor is implemented 544, and the appropriate bowtie is selected 546 based on the y-axis centering information using the methods previously described herein. Accordingly, scanning is performed at 548. FIG. 17 illustrates an implementation of the method illustrated in FIG. 11 when only an AP patient scout is available. Fundamentally, the method shown in FIG. 17 is substantially similar to that of FIG. 16; however, the y-axis centering error can not be directly determined since it is in the same orientation as the scout projections. Nevertheless, an estimate of the y-axis error relative to a reference position can be made if elevation information relative to the surface of the patient is available. Once the AP scout scan is complete 610, the system determines whether the surface elevation of the patient is known 612. If the surface elevation of the patient is unknown 614, the operator is prompted to manually select a bowtie filter configuration and calculate tube current per traditional manual methods 616 and a scan is performed 617. However, if the surface elevation of the patient is known or derived 618, as will be described with respect to FIGS. 18-20, an estimation of y mis-centering is performed 620. The estimation of y mis-centering is then compared to a threshold 622. If the mis-centering is less than the threshold 624, indicating that the current position of the patient is within the imaging tolerance of the system, no adjustment is necessary and the system is ready for scanning 626. However, if the mis-centering is greater than the threshold 628, the operator is notified of the centering error 630 and presented with an auto-correction prompt whereby the operator is prompted to accept or reject 632 the table elevation change. However, it is contemplated that operator approval may be bypassed whereby auto-correction is completed without prior operator approval 632. As was described with respect to FIGS. 11 and 12, should the operator reject the auto-correction 634, the operator uses a graphical indication or other means to enter a user-selected centering correction 636 according to which scanning is performed 638. Should the operator accept the auto-correction 640, the patient elevation is automatically corrected 642. The PA is then corrected 644 for the estimated y-axis centering error. This is done by direct geometric calculations or as a fitted function of elevation, PA, and OR, as will be described with respect to FIG. 18-20. As such, mA modulation is determined 646, the mA boost factor is implemented 648, and the appropriate bowtie is selected 650 based on the y-axis centering information using the methods previously described herein. Accordingly, the system is ready for scanning 652. However, it is also contemplated that estimations for PA, PM and mis-centering may be generated from the surface contour of the patient. As such, it is possible to determine mA modulation, boost mA to compensate for patient mis-centering, and select a desired bowtie configuration without the benefit of scout scans. That is, for the selection of the bowtie filter configuration, it is assumed that the patient is centered and the bowtie configuration is selected based on patient size estimated from the PM and density assumption of μ as previously described herein. Referring to FIGS. 18, 19, and 20, surface elevation information about the patient can be obtained by various methods. If the patient 706 is resting directly on the patient table, as in FIG. 18, the table elevation can be used to determine y-axis centering error. Specifically, with respect to FIG. 18, the table height 708 is known and, as such, the upper horizontal axis 710 of the patient 706 is known or reasonably estimated. Therefore, once the vertical axis 712 is determined, as described above, the upper center 714 of the patient 706 can be determined from the intersection of the upper horizontal axis 710 of the patient 706 and the vertical axis 712. Accordingly, the center 716 of the patient 706 is disposed halfway between the upper center 714 and the table height 708. Given the determination of these values, table elevation relative to isocenter (E) can be calculated by solving for the equation E=R+H−C, wherein H is the height of the table 714, R is the difference between the center 716 of the patient 706 and the table height 708, and C is the height of the upper center 714 of the patient 706. Specifically, mis-centering is determined by measuring the offset of the contour projections from isocenter. However, in cases where the patient 706 is propped up, as in FIG. 19, with pillows or other positioning devices 718, the centering can be determined from a laser or sonic displacement measuring device positioned on the gantry or otherwise disposed on the scanner to locate the top surface of the patient 706. As such, a vector of position information is collected and associated with each scout projection to allow the centering error to be calculated as a function of the z-direction. Specifically, since the center 716 of the patient 706 cannot readily be readily discerned because it is not disposed halfway between the upper center 714 and the table height 708 due to the offset created by the positioning device 718, as shown in FIG. 18, a laser or sonic displacement sensor 720 may be utilized to determine a distance L to the upper horizontal axis 710 of the patient 706. As such, E can be calculated in this case according to: E=C−R−L. However, referring to FIG. 20, it is also contemplated that a plurality of lasers and/or sonic displacement 720 sensors may be utilized to measure the distance from an array of points to obtain the specific contour of the patient 706. As such, an improved accuracy determination of overall patient contour is achieved. In any case, the PA can be determined from the external patient contour and the μ for the associated anatomy as described previously herein. The OR is determined directly from the distance measurements or from the PM which can be determined from the μ and patient surface distances. Mis-centering is determined by measuring offset of the contour projections from isocenter. Once the contour of the patient is known, it is possible to calculate the projection error ratio and fit it to a cubic or other function of elevation, PA, and OR to determine equation coefficients in order to calculate the PA corrected for y-axis centering error according to the following: PA = P / C1 + ( C2 * E ) + ( C3 * p ) + ( C4 * O ) + ( C5 * E * P ) + ( C6 * E * O ) + ( C7 * P * O ) + ( C8 * E 2 ) + ( C9 * P 2 ) + ( C10 * O 2 ) + ) C11 * E * P * O ) + ( C12 * E 2 * P ) + ( C13 * E 2 * O ) + ( C14 * P 2 * E ) + ( C15 * P 2 * O ) + ( C16 * O 2 * P ) + ( C17 * O 2 * P ) + ( C18 * E 3 ) ; wherein: Eq coeff Variable C1 constant C2 elevation C3 PA C4 OVR C5 elevation * PA C6 elevation * OVR C7 PA * OVR C8 elevation2 C7 PA2 C10 OVR2 C11 elevation * PA * OVR C12 elevation2 * PA C13 elevation2 * OVR C14 PA2 * elevation C15 PA2 * OVR C16 OVR2 * elevation C17 OVR2 * PA C18 OVR3 and E is the table elevation relative to isocenter; P is the measured projection area; PA is the projection area corrected for table/patient elevation; and O is the oval ratio. It is contemplated that the above-described invention be utilized with “third generation” CT systems as well as a wide variety of other CT-type systems. That is, it is contemplated that the present invention may be utilized with energy integrating, PC, and ED CT detector systems. Furthermore, it is contemplate that the above-described invention may be utilized with non-traditional and non-medical CT applications. For example, it is contemplated that the above-described invention may be utilized with a non-invasive package/baggage inspection system, such as the system shown in FIG. 21. Referring now to FIG. 21, package/baggage inspection system 800 includes a rotatable gantry 810 having an opening 812 therein through which packages or pieces of baggage may pass. The rotatable gantry 810 houses a high frequency electromagnetic energy source 814 aligned with an attenuation filter 815 as well as a detector assembly 816. A conveyor system 818 is also provided and includes a conveyor belt 820 supported by structure 822 to automatically and continuously pass packages or baggage pieces 824 through opening 812 to be scanned. Objects 824 are fed through opening 812 by conveyor belt 820, imaging data is then acquired, and the conveyor belt 820 removes the packages 824 from opening 812 in a controlled and continuous manner. As a result, postal inspectors, baggage handlers, and other security personnel may non-invasively inspect the contents of packages 824 for explosives, knives, guns, contraband, and the like. Therefore, in accordance with one embodiment of the current invention, a method of diagnostic imaging is disclosed that includes determining a position of a subject in a scanning bay relative to a reference position, automatically adjusting an attenuation characteristic of an attenuation filter based on the determined position of the subject and imaging the subject. In accordance with another embodiment of the invention, a computer readable storage medium is disclosed that has stored thereon a computer program representing a set of instructions. When the instructions are executed by at least one processor, the at least one processor is caused to receive feedback regarding mis-centering of a subject to be scanned, determine a value of mis-centering of the subject to be scanned, and adjust at least one of an attenuation filter configuration and a subject position based on the value of mis-centering. The processor is then caused to acquire radiographic diagnostic data from the subject. In accordance with still another embodiment of the invention, a tomographic system is disclosed. The tomographic system includes a rotatable gantry having a bore centrally disposed therein, a table movable within the bore and configured to position a subject for tomographic data acquisition within the bore, and a high frequency electromagnetic energy projection source positioned within the rotatable gantry and configured to project high frequency electromagnetic energy toward the subject. A detector array is disposed within the rotatable gantry and configured to detect high frequency electromagnetic energy projected by the projection source and impinged by the subject and an attenuation filter positioned between the high frequency electromagnetic energy projection source and the subject. A computer is programmed to adjust at least one of an attenuation characteristic of the attenuation filter and a table position based on a specific position of the subject in the bore. In accordance with yet another embodiment of the invention, a method of centering a subject in a medical imaging device is disclosed that includes positioning a subject in a scanning bay, comparing a center of mass of the subject to a reference point, and repositioning the subject in the scanning bay to reduce a difference in position between the center of mass of the subject and the reference point. In accordance with another embodiment of the invention, a computer readable storage medium having stored thereon a computer program representing a set of instructions is disclosed. The instructions, when executed by at least one processor, causes the at least one processor to determine a centroid of a subject, determine a value of mis-centering of the centroid of the subject within a medical imaging device, and adjust a position of the subject within the imaging device to compensate for the value of mis-centering. In accordance with yet another embodiment of the invention, a method of medical imaging is disclosed that includes positioning a subject in a medical imaging device, determining a value of mis-elevation of the subject, and adjusting an elevation of the subject device to reduce the value of mis-elevation. In accordance with still another embodiment of the invention, a tomographic system is disclosed that includes a rotatable gantry having a bore centrally disposed therein, a table movable within the bore and configured to position a subject for tomographic data acquisition within the bore, and a high frequency electromagnetic energy projection source positioned within the rotatable gantry and configured to project high frequency electromagnetic energy toward the subject. The tomographic system also includes a detector array disposed within the rotatable gantry and configured to detect high frequency electromagnetic energy projected by the projection source and impinged by the subject and computer. The computer is programmed to determine a centroid of the subject and adjust an elevation of the subject to align the centroid with a reference position. In accordance with one embodiment of the invention, a method of imaging is disclosed that includes positioning a subject in an imaging device, performing at least one scout scan, and marking a user-defined region-of-interest (ROI). An attenuation characteristic of an attenuation filter is then automatically adjusted based on the user-defined ROI. In accordance with another embodiment of the invention, a tomographic system is disclosed that includes a rotatable gantry having a bore centrally disposed therein, a table movable within the bore and configured to position a subject for tomographic data acquisition, and a high frequency electromagnetic energy projection source positioned within the rotatable gantry and configured to project high frequency electromagnetic energy toward the subject. A detector array is disposed within the rotatable gantry and is configured to detect high frequency electromagnetic energy projected by the projection source and impinged by the subject. An attenuation filter is positioned between the high frequency electromagnetic energy projection source and the subject. A computer is included that is programmed to display a user interface including an illustration of a position of the subject and allow selection of a ROI and determine an attenuation profile of the attenuation filter based on the user-selected ROI. In accordance with another embodiment of the invention, a computer readable storage medium having stored thereon a computer program representing a set of instructions is disclosed. The instructions, when executed by at least one processor, cause the at least one processor to perform at least one scout scan, display an interface including a reconstructed image from the at least one scout scan and receive user-selection identifying a ROI. The instructions then cause the at least one processor to adjust at least one of an attenuation filter configuration and a subject position based on the ROI. In accordance with yet another embodiment of the invention, a tomographic system is disclosed that includes a rotatable gantry having a bore centrally disposed therein, a table movable within the bore and configured to position a subject for tomographic data acquisition within the bore, and a high frequency electromagnetic energy projection source positioned within the rotatable gantry and configured to project high frequency electromagnetic energy toward the subject. A detector array is disposed within the rotatable gantry and configured to detect high frequency electromagnetic energy projected by the projection source and impinged by the subject and at least one sensor is included to provide subject position feedback. In accordance with another embodiment of the invention, a computer readable storage medium is disclosed having stored thereon a computer program representing a set of instructions. When the instructions are executed by at least one processor, the at least one processor is caused to receive feedback regarding a subject position from at least one sensor of an imaging device and determine a centering error from the feedback. In accordance with one more embodiment of the invention, a method of imaging is disclosed that includes positioning a subject in an imaging device, collecting positioning information of the subject from at least one sensor disposed in proximity of the imaging device, and determining a relative position of the subject within the imaging device from at least the position information. The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates generally to diagnostic imaging and, more particularly, to a method and apparatus to optimize dose efficiency by dynamically filtering radiation emitted toward the subject during radiographic imaging in a manner tailored to the position and/or shape of the subject to be imaged. Typically, in computed tomography (CT) imaging systems, an x-ray source emits a fan-shaped beam toward a subject or object, such as a patient or a piece of luggage. Hereinafter, the terms “subject” and “object” shall include anything capable of being imaged. The beam, after being attenuated by the subject, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-ray beam by the subject. Each detector element of the detector array produces a separate electrical signal indicative of the attenuated beam received by each detector element. The electrical signals are transmitted to a data processing system for analysis and subsequent image reconstruction. There is an increasing desire to reduce radiation expose to a patient during radiographic data acquisition. It is generally well known that significant radiation or “dose” reduction may be achieved by using an attenuation filter to shape the intensity profile of an x-ray beam. Surface dose reductions may be as much as 50% using an attenuation filter. It is also generally known that radiation exposure for data acquisition from different anatomical regions of a patient may be optimized by using specifically shaped attenuation filters tailored to the anatomical region-of-interest (ROI). For example, scanning of the head or a small region of a patient may be optimized using a filter shape that is significantly different than a filter used during data acquisition from the heart. Therefore, it is desirable to have an imaging system with a large number of attenuation filter shapes available to best fit each patient and/or various anatomical ROIs. However, fashioning an imaging system with a sufficient number of attenuation filters to accommodate the numerous patient sizes and shapes that may be encountered can be impractical given the variances in a possible population. Additionally, manufacturing an imaging system with a multitude of attenuation filters would increase the overall manufacturing cost of the imaging system. Further, for optimum dose efficiency, i.e. best image quality at the lowest possible dose, the attenuation profile created by the attenuation filter should be particular to the patient. That is, it is desirable and preferred that when selecting a pre-patient or attenuation filter that it be adjusted according to the particulars of the patient, such as the patient's size, shape, and relative position in the bore of the scanner, be taken into account. By taking these and other particulars into consideration, radiation exposure can be optimized for the patient and the scan session. Known CT scanners use both an attenuation filter and dynamic current modulation to shape the intensity of the x-ray beam incident to the patient. To reduce radiation exposure, the attenuation filer is typically configured to minimize x-ray exposure to edges of the patient where path lengths are shorter and noise in the projection data has a less degrading impact on overall image quality. Accordingly, one such implementation of the attenuation filter is the bowtie filter, which, as a function of form, increases attenuation of x-ray intensity incident upon of the peripheral of the imaging subject. However, improper patient centering and/or bowtie filter selection can significantly degrade image quality and dose efficiency because x-ray attenuation is misapplied to the particulars of the subject. The bowtie filter is aligned with a point of maximum radiation dose or isocenter. The bowtie filter minimizes attenuation of x-ray intensity to isocenter and attenuates radiation significantly with radial distance beyond the center region of the bowtie, because, ideally, the isocenter corresponds to an imaging center of the subject. However, this is not always the case, e.g. when the subject is mis-centered in the scanner. FIG. 1 illustrates a bowtie filter ideally matched to a patient. Specifically, bowtie filter 10 is aligned within an imaging beam 12 such that an x-ray profile 14 is generated by the incidence of the imaging beam 12 upon the patient 16 . However, if the patient 16 is not centered with respect to the bowtie center and the corresponding isocenter, significant image degradation can occur. The degradation is dependent upon a multitude of factors, such as the size of the central region of the bowtie filter, size and shape of the patient, and the amount and direction of patient mis-centering. FIG. 2 illustrates one such example of a bowtie filter opening that is improperly matched to the patient. That is, the bowtie filter 10 is aligned within the imaging beam 12 such that an improper x-ray profile 18 is generated by the incidence of the imaging beam 12 upon the patient 16 . Specifically, photon incidence or flux at the edges of the patent may increase image noise to a level that may be prohibitively high for diagnostically valuable images. Recent improvements in imaging devices include a continuously adjustable bowtie filter having a pair of filtering elements to compensate for factors that may lead to non-ideal imaging. Such a filter is described in U.S. Ser. No. 10/605,789, the disclosure of which is incorporated herein and is assigned to GE Medical Systems Global Technology Co., LLC, which is also the Assignee of this application. Each filter element has a long low attenuating tail section that varies in attenuation power across its length such that as the elements are moved relative to one another, the attenuation of the beam is controlled. Each filter element is dynamically positioned with a dedicated motor assembly. The filter elements may be positioned in the x-ray beam so as to shape the profile of the x-ray beam to match a desired ROI or anatomical point-of-interest. The filter portions are positionable and adjustable using precision positioners to control the radiation pattern for the patient or the anatomy currently being imaged. However, image degradation may occur if the bowtie opening created is too small for a large patient since useful x-ray needed for imaging is attenuated by the bowtie thereby causing high image noise. As a result, the operator must manually determine the appropriate beam width and position according to size, shape, and positioning of the subject within the scanner bore. A properly sized bowtie configuration, however, does not ensure acceptable image quality. If the subject is mis-centered, image degradation may still persist. This degradation is typically a result of two factors. First, if subject mis-centering is caused by mis-elevation of the subject with respect to the bowtie filter then the calculation of tube current will result in an underestimate of the subject size. Referring to FIG. 3 , a patient 16 is shown mis-centered in an x-ray beam 12 . Specifically, the patient 16 is positioned at an improper centering elevation 20 by a centering error 22 below a proper centering elevation or y-position 24 . As a result, a portion of the imaging beam 26 is not incident upon the patient 16 and a projection area 28 is understated by an error margin 30 because the patient 16 intercepts fewer rays in the imaging beam 12 . As such, when determining tube current with the imaging tube at top-dead-center, as is convention, a lower tube current than actually required for proper imaging will be determined. As a result of the lower tube current, excessive image noise will be present relative to the user's selection. For example, a calculated milliamp (mA) that is 30% lower than actually required for proper imaging occurs for a typical 30 cm×20 cm body mis-centered in elevation by three cm. In such a case, noise introduction is increased by approximately 15% from a properly centered, properly imaged, patient. Secondly, patient mis-centering with respect to elevation may also position the thickest part of the patient such that x-rays for lateral projections pass through the thickest part of the bowtie which results in over-attenuation of the imaging beam. Referring to FIG. 4 , the patient 16 is shown mis-centered within the imaging beam 12 by a centering error 22 below the proper centering elevation 24 . As a result, the imaging beam 12 passes through the thickest parts of the bowtie filter 10 and patient 16 , as exemplified by projection route 32 . Such mis-centering can result in an additional image noise increase by as much as 70%. These errors can cause images of such high noise that the diagnostic value is compromised. Moreover, since traditional CT imaging methods rely on operator input to perfect patient centering, including elevation, elevational patient mis-centering can be common. Furthermore, traditional edge detection methods rely on identifying the center of the patient indirectly by detecting the edges of the patient, which can be particularly susceptible to error. Additionally, recent advancements in detector technology has increased the desire to control x-ray flux management to within very accurate constraints. For example, photon counting (PC) and energy discriminating (ED) detector CT systems have the potential to greatly increase the medical benefits of CT by differentiating materials such as a contrast agent in the blood and calcifications that may otherwise be indistinguishable in traditional CT systems. Additionally, PC and ED CT systems produce less image noise for the same dose than photon energy integrating detectors and hence can be more dose efficient than conventional CT systems. However, while PC and ED CT systems have the potential to realize numerous advantages over traditional CT detectors, the systems may be impractical for some scan protocols. Therefore, it would be desirable to design an apparatus and method to automatically control flux by dynamically filtering radiation emitted toward the subject during radiographic imaging in a manner tailored to the position and/or shape of the subject to be imaged so as to optimize radiation exposure during data acquisition. It would be further desirable to have a system that tailors the radiation emitted toward the subject during data acquisition based on a scout scan of the subject. Furthermore, it would be advantageous to have a system and method of controlling x-ray flux management to avoid photon pileup. Additionally, it would be desirable to have a system and method of dynamically adjusting radiation filtering to follow a user defined-region-of interest. It would also be desirable to have an apparatus to automatically collect patient centering and surface elevation information include a direct method of detecting patient centering. Furthermore, it would be desirable to have a method of accurately determining patient mis-centering within an imaging volume and adjusting the patient position to compensate for the determined mis-centering. | <SOH> BRIEF DESCRIPTION OF THE INVENTION <EOH>The present invention is a directed method and apparatus to optimize radiation exposure that overcomes the aforementioned drawbacks. The present invention includes a method and apparatus for collecting imaging subject positioning information and automatically controlling an x-ray dose to be tailored to the position of the imaging subject. In accordance with one aspect of the invention, a tomographic system is disclosed that includes a rotatable gantry having a bore centrally disposed therein, a table movable within the bore and configured to position a subject for tomographic data acquisition within the bore, and a high frequency electromagnetic energy projection source positioned within the rotatable gantry and configured to project high frequency electromagnetic energy toward the subject. A detector array is disposed within the rotatable gantry and configured to detect high frequency electromagnetic energy projected by the projection source and impinged by the subject and at least one sensor is included to provide subject position feedback. In accordance with another aspect of the invention, a computer readable storage medium is disclosed having stored thereon a computer program representing a set of instructions. When the instructions are executed by at least one processor, the at least one processor is caused to receive feedback regarding a subject position from at least one sensor of an imaging device and determine a centering error from the feedback. In accordance with another aspect of the invention, a method of imaging is disclosed that includes positioning a subject in an imaging device, collecting positioning information of the subject from at least one sensor disposed in proximity of the imaging device, and determining a relative position of the subject within the imaging device from at least the position information. Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings. | 20040127 | 20071225 | 20050428 | 99394.0 | 0 | SONG, HOON K | SYSTEM AND METHOD OF COLLECTING IMAGING SUBJECT POSITIONING INFORMATION FOR X-RAY FLUX CONTROL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,765,657 | ACCEPTED | Method and system for spread spectrum gating | A gating module for gating an image intensifier tube. The gating module includes a frequency generator generating a base signal having a base frequency. A modulator spread-spectrum modulates the base frequency of the base signal to generate a modulated signal. A gating circuit coupled to the modulator generates a gating signal in response to the modulated signal. | 1. A gating module for gating an image intensifier tube, the gating module comprising: a frequency generator generating a base signal having a base frequency; a modulator for spread-spectrum modulating said base frequency of said base signal to generate a modulated signal; and a gating circuit coupled to said modulator, said gating circuit generating a gating signal in response to said modulated signal. 2. The gating module of claim 1 wherein: said frequency generator and said modulator are implemented by an oscillator. 3. The gating module of claim 2 wherein: said oscillator includes a first resistor establishing said base frequency. 4. The gating module of claim 3 wherein: said oscillator includes a second resistor coupled to a modulation pin of said oscillator, said second resistor establishing a percent of modulation of said base frequency. 5. The gating module of claim 4 wherein: said oscillator includes a switch connecting said modulation input to ground, closure of said switch deactivating said modulating said base frequency. 6. The gating module of claim 2 wherein: said oscillator is a band-limited random noise generator. 7. The gating module of claim 1 wherein: said modulator is a pseudorandom sequence generator. 8. The gating module of claim 1 wherein: said gating circuit is a one-shot. 9. A system for viewing an object under low light conditions, the system comprising: an image intensifier tube generating an image of said object; a power supply providing power to said image intensifier tube; a gating module coupled to said power supply, said gating module generating a spread-spectrum modulated gating signal to said power supply to provide gated power to said image intensifier tube. 10. The system of claim 9 wherein: said image intensifier tube includes a sensor, a microchannel plate and an anode. 11. The system of claim 9 wherein: said sensor is a photocathode sensor. 12. The system of claim 9 wherein: said gating module includes: a frequency generator generating a base signal having a base frequency; a modulator for spread-spectrum modulating said base frequency of said base signal to generate a modulated signal; and a gating circuit coupled to said modulator, said gating circuit generating said gating signal in response to said modulated signal. 13. The system of claim 12 wherein: said frequency generator and said modulator are implemented by an oscillator. 14. The system of claim 13 wherein: said oscillator includes a first resistor establishing said base frequency. 15. The system of claim 14 wherein: said oscillator includes a second resistor coupled to a modulation pin of said oscillator, said second resistor establishing a percent of modulation of said base frequency. 16. The system of claim 15 wherein: said oscillator includes a switch connecting said modulation input to ground, closure of said switch deactivating said modulating said base frequency. 17. The system of claim 13 wherein: said oscillator is a band-limited random noise generator. 18. The gating module of claim 12 wherein: said modulator is a pseudorandom sequence generator. 19. The system of claim 12 wherein: said gating circuit is a one-shot. 20. A method for gating an image intensifier tube, the method comprising: generating a base signal having a base frequency; spread-spectrum modulating said base frequency of said base signal to generate a modulated signal; generating a gating signal in response to said modulated signal; and applying said gating signal to said image intensifier tube. | BACKGROUND OF THE INVENTION Night vision devices enable a user to view a scene with little or no visible ambient light. Law enforcement and military personnel often use night vision devices during night time surveillance and maneuvers. Night vision devices typically employ an image intensifier tube that amplifies light in order to provide an enhanced image to the user. Gated night vision devices, however, are susceptible to interference associated with oscillatory ambient light, which causes bright flashes of light that interfere with the viewed image. Some systems attempt to avoid the interference by determining the frequency of the ambient light and then using a gating frequency that avoids the interference. A disadvantage of these systems is that interference may occur if the frequency of the ambient light changes. Additionally, these systems may experience interference if the ambient light includes multiple frequencies or does not follow a regular pattern. Consequently, avoiding interference has posed challenges for the design of gated night vision devices and other gated sensors. Gating the cathode of image tubes combined with periodic scene brightness variations can produce intermodulation products, which fall within the band that is detectable by the human eye. Since it is not possible to predict the frequency of scene brightness variations, such as line frequency flicker at 50, 60, 100, 120 hz, or computer monitor flicker at frequencies between 15 hz and several hundred khz, intermodulation products can be generated in the visible range. Furthermore, gating at a fixed frequency may produce a gating signal, which occurs at a frequency that is a mechanical resonant frequency of image tube elements. This makes the image tube assembly produce an audible sound. Audible emissions from a night vision system are undesirable. BRIEF SUMMARY OF THE INVENTION An embodiment of the invention is a gating module for gating an image intensifier tube. The gating module includes a frequency generator generating a base signal having a base frequency. A modulator spread-spectrum modulates the base frequency of the base signal to generate a modulated signal. A gating circuit coupled to the modulator generates a gating signal in response to the modulated signal. Another embodiment of the invention is a system for viewing an object under low light conditions. The system includes an image intensifier tube generating an image of the object. A power supply provides power to the image intensifier tube. A gating module is coupled to the power supply. The gating module generates a spread-spectrum modulated gating signal to the power supply to provide gated power to the image intensifier tube. Another embodiment of the invention is a method for gating an image intensifier tube. The method includes generating a base signal having a base frequency. The base frequency of the base signal is spread-spectrum modulated said to generate a modulated signal. A gating signal is generated in response to the modulated signal and applied to the image intensifier tube. BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawings, wherein like elements are numbered alike in the several FIGURES: FIG. 1 is a block diagram of one embodiment of a system for viewing an object; FIG. 2 is a block diagram of a gating module in one embodiment; FIG. 3 is a schematic diagram of a gating module in one embodiment; and FIGS. 4A-4C depict waveforms in the gating module. DETAILED DESCRIPTION FIG. 1 is a block diagram of one embodiment of a system 101 for viewing an object under low light conditions. System 101 generally includes optics 30 that receive light 32 from a scene that includes an object 34 to be viewed. A gated sensor device, for example, an image intensifier tube 36, receives and amplifies light 32 to produce an image 38 of object 34 for a viewer 40. A gating module 10 provides a gating signal that directs a power supply 44 to supply a voltage to image intensifier tube 36 that reduces interference while amplifying light 32, thus improving image 38. In one embodiment, gating module 10 and power supply 44 may be integrated at a circuit design level. In one embodiment, power supply 44 includes a source of electrical power, for example, a battery. Image intensifier tube 36 includes a sensor 18, a micro-channel plate 48, and an anode 50. Light 32 incident on sensor 18 causes photoelectrons to be emitted in proportion to the intensity of light 32. Micro-channel plate 48 multiples the photoelectrons, which flow to anode 50. Anode 50 provides image 38, which is transmitted to viewer 40. Image intensifier tube 36 is gated on and off with a gating frequency to amplify light 32. In one embodiment, sensor 18 is gated. Any construction of sensor 18, micro-channel plate 48, and/or anode 50, however, may be gated. Sensor 18 may include a photo cathode or any other suitable imaging sensor, such as a charged couple device array or an infrared focal plane array. When image intensifier tube 36 is gated on, light 32 is amplified, and when image intensifier tube 36 is gated off, light 32 is not amplified. Although image intensifier tube 36 is used in this example, any gated sensor device may be used, for example, a photo multiplier tube, a biased semiconductor sensor, or a biased photo voltaic sensor. A display 52 displays information about light 32 to viewer 40. FIG. 2 illustrates an exemplary gating module 10 in embodiments of the invention. Gating module 10 includes a frequency generator 60 that generates a base signal having a base frequency for gating the image intensifier tube 36. A modulator 62 modulates the frequency of the base signal to provide a modulated signal. In exemplary embodiments, the modulator 62 provides a spread spectrum modulation. The percent of frequency modulation variation may be user-defined. The modulator 62 may be deactivated to provide the base signal to gating circuit 64. Gating circuit 64 generates a gating signal to the image intensifier tube 36, including sensor 18. FIG. 3 is a schematic diagram of a gating module in one embodiment. The frequency generator 60 and modulator 62 are implemented using a Linear Tech LTC6902 multi-phase oscillator with spread spectrum frequency modulation. A first resistor Rset establishes the frequency of the base signal. A second resistor Rmod is used to set the modulation percentage of the base frequency. A switch S1 couples the modulation input of the oscillator to ground. When switch S1 is closed, modulation of the base signal is deactivated. In an embodiment of the invention, the resistors Rset and Rmod are selected to define a base frequency with 20% spread spectrum modulation added. An output from the oscillator is provided to the threshold input of a 555 timer that is configured as a one-shot. The 555 timer produces a series of narrow low-logic level pulses, the pulse width of which is determined by resistor and capacitor component values connected to the 555 timer to form the one-shot circuit. The repetition rate of the pulses is controlled by the repetition rate of the signal from the spread spectrum oscillator 60/62. The output of the 555 timer is fed through the transistor of an optocoupler which allows a feedback control circuit to vary the amount of current that passes through the optocoupler. The current charges a timing capacitor to a threshold known by a threshold detector. When the threshold is exceeded, the threshold detector controls a high voltage switch that applies a signal of the correct polarity to the image intensifier to the intensifier off. The intensifier remains off until the next period is initiated by the spread spectrum oscillator. By controlling the amount of current into the LED of the optocoupler, the current that charges the time capacitor can be varied, the rate at which it charges can be varied, the amount of time before the threshold is reached can be varied and the ON time of the image intensifier can be varied. FIGS. 4A-4C depict waveforms in the gating module 10. FIG. 4A depicts voltage at the output of the modulator 62. The frequency f is randomly varied based on a user defined percentage established by resistor Rmod. FIG. 4B depicts a voltage at the input of gating circuit 64. In the embodiment shown in FIG. 3, this voltage appears at the threshold pin of the 555 timer. FIG. 4C depicts voltage at the output of the gating module 64. Embodiments of the spread-spectrum gating are not limited to modulation of a base frequency as described above. Alternate embodiments include using a pseudorandom sequence generator as modulator 62. The oscillator 60/62 may also be implemented together as a band-limited random noise generator. The use of a spread-spectrum modulated gating signal provides several advantages. Tests have verified that when spread spectrum gating was enabled there was a visual affect on flicker when looking at a CRT monitor. When spread-spectrum gating was enabled, the audible emissions caused by the image tube resonance were reduced. Tests have also verified that spread-spectrum gating reduces the amplitude of beat frequency (gating to scene) flicker. RF emissions will be reduced as the spread-spectrum gating reduces the amplitude of the power at any given frequency. While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out the invention, but that the invention will include all embodiments falling within the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Night vision devices enable a user to view a scene with little or no visible ambient light. Law enforcement and military personnel often use night vision devices during night time surveillance and maneuvers. Night vision devices typically employ an image intensifier tube that amplifies light in order to provide an enhanced image to the user. Gated night vision devices, however, are susceptible to interference associated with oscillatory ambient light, which causes bright flashes of light that interfere with the viewed image. Some systems attempt to avoid the interference by determining the frequency of the ambient light and then using a gating frequency that avoids the interference. A disadvantage of these systems is that interference may occur if the frequency of the ambient light changes. Additionally, these systems may experience interference if the ambient light includes multiple frequencies or does not follow a regular pattern. Consequently, avoiding interference has posed challenges for the design of gated night vision devices and other gated sensors. Gating the cathode of image tubes combined with periodic scene brightness variations can produce intermodulation products, which fall within the band that is detectable by the human eye. Since it is not possible to predict the frequency of scene brightness variations, such as line frequency flicker at 50, 60, 100, 120 hz, or computer monitor flicker at frequencies between 15 hz and several hundred khz, intermodulation products can be generated in the visible range. Furthermore, gating at a fixed frequency may produce a gating signal, which occurs at a frequency that is a mechanical resonant frequency of image tube elements. This makes the image tube assembly produce an audible sound. Audible emissions from a night vision system are undesirable. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>An embodiment of the invention is a gating module for gating an image intensifier tube. The gating module includes a frequency generator generating a base signal having a base frequency. A modulator spread-spectrum modulates the base frequency of the base signal to generate a modulated signal. A gating circuit coupled to the modulator generates a gating signal in response to the modulated signal. Another embodiment of the invention is a system for viewing an object under low light conditions. The system includes an image intensifier tube generating an image of the object. A power supply provides power to the image intensifier tube. A gating module is coupled to the power supply. The gating module generates a spread-spectrum modulated gating signal to the power supply to provide gated power to the image intensifier tube. Another embodiment of the invention is a method for gating an image intensifier tube. The method includes generating a base signal having a base frequency. The base frequency of the base signal is spread-spectrum modulated said to generate a modulated signal. A gating signal is generated in response to the modulated signal and applied to the image intensifier tube. | 20040126 | 20060919 | 20050728 | 64653.0 | 0 | LUU, THANH X | METHOD AND SYSTEM FOR SPREAD SPECTRUM GATING | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,765,892 | ACCEPTED | Fuel injection system | During a short duration injection, a triangular geometry is drawn in terms of the injection rate with respect to time, while a trapezoidal geometry is drawn during a long duration injection. The ON timing of the drive pulse is determined to be at a valve opening pressure achieving time before the start point of formation in time of the geometry. An injection pulse duration is determined from “the valve opening pressure achieving time+a needle rise time−a valve closing pressure achieving time,” and then the OFF timing of the drive pulse is determined. | 1. A fuel injection system comprising: an injector for injecting high-pressure fuel, and a controller for determining request injection timing and a request injection quantity in response to a running condition of an internal combustion engine to controllably open or close the injector in accordance with the request injection timing and the request injection quantity, the controller further comprising: means for determining a geometry defined by a change in injection rate of the injector with respect to time, and determining drive signal generation timing and drive signal termination timing of the injector from the geometry of the injection rate having an area corresponding to the request injection quantity. 2. A fuel injection system according to claim 1, wherein the fuel injection system determines a geometry defined by a change in needle lift amount of the injector with respect to time, and converts the geometry of needle lift quantity to determine the geometry of the injection rate. 3. A fuel injection system according to claim 2, wherein the determination of the geometry of the injection rate by converting the geometry of needle lift quantity includes dividing an injection region into a seat aperture region in which an injection quantity is determined between a needle and a nozzle seat of the injector and an injection hole aperture region in which an injection quantity is determined in accordance with an aperture level of an injection hole of the injector, making a linear approximation of injection flow rate against needle lift quantity characteristics in the seat aperture region for an injection rate against needle lift quantity conversion, and making a linear approximation of injection flow rate against needle lift quantity characteristics in the injection hole aperture region for an injection rate against needle lift quantity conversion. 4. A fuel injection system according to claim 1, wherein the geometry of the injection rate is drawn to have conditions of a pressure at which high-pressure fuel is supplied to the injector and a specification of a discharge line of the injector. 5. A fuel injection system according to claim 1, wherein the geometry of the injection rate is drawn in terms of a rising injection rate provided when the needle rises in the injector, a falling injection rate provided when the needle falls in the injector, and a maximum injection rate applied when the rising injection rate reaches a maximum injection rate. 6. A fuel injection system according to claim 1, wherein the drive signal generation timing of the injector is determined to be at a valve opening pressure achieving time before a start point of formation in time of the injection rate against time geometry, the valve opening pressure achieving time being measured from a valve opening command being given to the injector to an actual start of fuel injection by the injector. 7. A fuel injection system according to claim 1, wherein the fuel injection system determines the valve opening pressure achieving time measured from the start point of formation in time of the injection rate against time geometry until the valve opening command is provided to the injector to actually start injecting fuel, a valve closing pressure achieving time measured from a valve closing command being given to the injector until an injection rate actually starts falling, and a needle rise time measured from the start point of formation in time of the injection rate against time geometry until a control chamber of the injector reaches a valve closing pressure, and a duration measured from the drive signal generation timing to the drive signal termination timing of the injector is determined by Tds+Tqr−Tde1. 8. A fuel injection system according to claim 7, wherein the needle rise time is determined in terms of the request injection quantity, the rising injection rate provided when the needle rises in the injector, and the falling injection rate provided when the needle lowers in the injector. 9. A fuel injection system according to claim 6, wherein the valve opening pressure achieving time is determined by a function of a pressure of the high-pressure fuel supplied to the injector and multiple-injection intervals at which fuel is injected separately in a multiple number of times in once cycle. 10. A fuel injection system according to claim 1, wherein to correct for a variation in injection quantity, the controller employs at least one of the following injection parameters as an adjustment parameter, and stores the adjustment parameter as a learned value to reflect the value on a next injection, the injection parameters including the valve opening pressure achieving time measured from the start point of formation in time of the injection rate against time geometry until the valve opening command is provided to the injector to actually start injecting fuel, the rising injection rate provided when the needle rises in the injector, the falling injection rate provided when the needle lowers in the injector. the maximum injection rate applied when the rising injection rate reaches a maximum injection rate, the valve closing pressure achieving time measured from a valve closing command being given to the injector until an injection rate actually starts falling, the needle rise time measured from the start point of formation in time of the injection rate against time geometry until the control chamber of the injector reaches a valve closing pressure, and a duration measured from the drive signal generation timing to the drive signal termination timing of the injector. 11. A fuel injection system according to claim 10, wherein to correct for a variation in injection quantity, the controller employs two or more of the injection parameters as adjustment parameters and weights the adjustment parameters to correct for the variation in injection quantity, and stores the respective adjustment parameters as a learned value to reflect the value on a next injection. 12. A fuel injection system according to claim 1, wherein to correct for a variation in injection quantity, the controller estimates the variation in injection quantity as being caused by a change in a parameter of a predetermined portion defining a specification of the injector to employ the parameter of the predetermined portion as an adjustment parameter and store the adjustment parameter as a learned value to reflect the value on a next injection. 13. A method of controlling a fuel injection system utilizing an injector for injecting high-pressure fuel, the method comprising: providing a controller for determining request injection timing and a request injection quantity in response to a running condition of an internal combustion engine; controllably opening or closing the injector in accordance with the request injection timing and the request injection quantity; determining a geometry defined by a change in injection rate of the injector with respect to time; and determining a drive signal generation timing and a drive signal termination timing of the injector from the geometry of the injection rate having an area corresponding to the request injection quantity. 14. The method of controlling a fuel injection system according to claim 13, the method further comprising: determining a geometry defined by a change in needle lift amount of the injector with respect to time; and converting the geometry of needle lift amount to determine the geometry of the injection rate. 15. The method of controlling a fuel injection system according to claim 14, the method further comprising: determining the geometry of the injection rate by converting the geometry of needle lift amount by: dividing an injection region into a seat aperture region in which an injection quantity is determined between a needle and a nozzle seat of the injector and an injection hole aperture region in which an injection quantity is determined in accordance with an aperture level of an injection hole of the injector; making a linear approximation of injection flow rate against needle lift amount characteristics in the seat aperture region for an injection rate against needle lift amount conversion; and making a linear approximation of injection flow rate against needle lift amount characteristics in the injection hole aperture region for an injection rate against needle lift amount conversion. 16. The method of controlling a fuel injection system according to claim 13, the method further comprising: developing the geometry of the injection rate in accordance with conditions of a pressure at which high-pressure fuel is supplied to the injector and a specification of a discharge line of the injector. 17. The method of controlling a fuel injection system according to claim 13, the method further comprising: developing the geometry of the injection rate in accordance with a rising injection rate provided when the needle rises in the injector, a falling injection rate provided when the needle falls in the injector, and a maximum injection rate applied when the rising injection rate reaches a maximum injection rate. 18. The method of controlling a fuel injection system according to claim 13, further comprising: determining the drive signal generation timing of the injector to be at a valve opening pressure achieving time before a start point of formation in time of the injection rate against time geometry; and measuring the valve opening pressure achieving time from a valve opening command being given to the injector to an actual start of fuel injection by the injector. 19. The method of controlling a fuel injection system according to claim 13, the method further comprising: determining the valve opening pressure achieving time measured from the start point of formation in time of the injection rate against time geometry until the valve opening command is provided to the injector to actually start injecting fuel; determining a valve closing pressure achieving time measured from a valve closing command being given to the injector until an injection rate actually starts falling; determining a needle rise time measured from the start point of formation in time of the injection rate against time geometry until a control chamber of the injector reaches a valve closing pressure; and determining a duration measured from the drive signal generation timing to the drive signal termination timing of the injector by Tds+Tqr−Tde1. 20. The method of controlling a fuel injection system according to claim 19, further comprising: determining the needle rise time in terms of: the request injection amount, the rising injection rate provided when the needle rises in the injector, and the falling injection rate provided when the needle falls in the injector. | CROSS REFERENCE TO RELATED APPLICATIONS This application is based upon, claims the benefit of priority of, and incorporates by reference Japanese Patent Application No. 2003-21880 filed Jan. 30, 2003, and No. 2003-289869 filed Aug. 8, 2003. 1. Technical Field of the Invention The present invention relates to a fuel injection system for injecting fuel into an internal combustion engine (hereinafter referred to as the engine), and more particularly, to controlling the opening and closing operation that supplies fuel to the injector. 2. Background of the Invention As an example, reference will be made to a conventional fuel injection system shown in FIG. 5 that employs multiple injections (or multi-stage injections of fuel to be separately carried out a multiple number of times in one cycle). As shown in FIG. 5, in a multiple number of times of injection in one cycle, the second and subsequent stage injections are affected by the previous injection (due to pulsation that occurs in a line for supplying fuel to the injector), which leads to a variation in injection commencement delay or injection termination delay. This will be described more specifically with reference to the lower portion of FIG. 5. Suppose that a drive pulse as shown in the lower portion in FIG. 5 is provided to the injector in the absence of pulsation. In this case, the injection rate starts rising from the point in time at which the valve opening pressure achieving time Tds has elapsed after the drive pulse is generated, and starts falling from the point in time at which the valve closing pressure achieving time Tde1 has elapsed after the drive pulse is terminated. Thus, the geometry drawn in terms of the injection rate takes the shape of a reference triangle, as shown in FIG. 5. An injection quantity Q′ to be actually injected from the injector is a quantity corresponding to the area of the reference triangle. Suppose that the effect of pulsation causes an increase in fuel pressure to be supplied to the injector. In this case, in general, the valve opening pressure achieving time Tds is reduced by the amount of arrow (1) of FIG. 5, while the maximum injection rate is increased as shown by arrow (2), and the needle falling time Tde2 is extended as shown by arrow (3). As a result, the geometry drawn in terms of the injection rate takes the shape of a larger triangle, as shown in FIG. 5. That is, the injection quantity Q′ that is actually injected from the injector is a quantity corresponding to the area of the larger triangle, thus causing the injection quantity to be larger than the request injection quantity Q. To the contrary, a decrease in fuel pressure to be supplied to the injector due to the effect of pulsation would cause the geometry drawn in terms of the injection rate to be smaller than the reference triangle, thus making the injection quantity less than the request injection quantity Q. The effect of pulsation would also vary the pressure of fuel to be supplied to the injector thereby causing a variation in the valve opening pressure achieving time Tds. This causes a deviation in actual injection timing before or after the request injection start timing made by the controller. In the prior art, independently provided were a correction map for determining the valve opening pressure achieving time Tds varied by pulsation, a correction map for determining the valve closing pressure achieving time Tde1 varied by pulsation, and a correction map for determining the injection quantity varied by pulsation, in addition to a map for determining a fundamental pulse duration of the injector from the fundamental injection quantity and a common rail pressure. In these respective maps, an independent operation was carried out to correct the output timing of a drive pulse, thereby preventing a variation in injection quantity due to the effect of pulsation (e.g., see Japanese Patent Laid-Open Publication No. Hei 10-266888). In the prior art mentioned above, even to solve a drawback caused by one factor, such as the effect of pulsation, it is necessary to use a number of independent correction maps to separately determine the valve opening pressure achieving time Tds, the valve closing pressure achieving time Tde1, and the injection quantity, which are varied by pulsation, and use the resulting values for correction of the output timing of drive pulses. Accordingly, for example, in multi-stage injection, it is necessary to perform an operational step using a number of independent correction maps by the number of the injection stages, thereby imposing a very heavy operational load on a controller. This load is caused by the multiple operation steps of correcting the drive pulse and thus an enormous number of adaptation steps are required for the operational step. SUMMARY OF THE INVENTION The present invention was developed in view of the aforementioned problems. It is therefore the object of the present invention to provide a fuel injection system that allows for the reduction of the adaptation steps to correct the output duration and timing of a drive pulse for drivingly closing or opening an injector. The fuel injection system employing the means according to a first aspect determines a geometry defined by a change in injection rate of the injector with respect to time, and drive signal generation timing and drive signal termination timing of the injector from the geometry of the injection rate having an area corresponding to the request injection quantity Q. As described above, the fuel injection system employing the means according to the first aspect determines the drive signal generation timing and the drive signal termination timing of the injector from the geometry of the injection rate having an area corresponding to the request injection quantity Q. Accordingly, this permits an operational result (the formation of the geometry of the injection rate) based on a certain factor (e.g., a change in valve opening pressure achieving time Tds) to be automatically reflected on another operational result (such as the drive signal generation timing or the drive signal termination timing that is derived from the geometry of the injection rate). It is thus possible to significantly reduce the adaptation time required of the controller. The fuel injection system employing the means according to a second aspect determines the geometry defined by a change in needle lift quantity of the injector with respect to time and converts the geometry of needle lift quantity to determine the geometry of the injection rate. The fuel injection system employing the means according to a third aspect allows the determination of the geometry of the injection rate by converting the geometry of the needle lift quantity to include dividing an injection region into a seat aperture region and an injection hole aperture region. In the seat aperture region, an injection quantity is determined between a needle and a nozzle seat of the injector, while in the injection hole aperture region, an injection quantity is determined in accordance with an aperture level of an injection hole of the injector. Also included are making a linear approximation of injection flow rate against needle lift quantity characteristics in the seat aperture region for an injection rate against needle lift quantity conversion, and making a linear approximation of injection flow rate against needle lift quantity characteristics in the injection hole aperture region for an injection rate against needle lift quantity conversion. The fuel injection system employing the means according to a fourth aspect allows the geometry of the injection rate to be drawn at least using a pressure at which high-pressure fuel is supplied to the injector and a specification of a discharge line of the injector. That is, using the supply fuel pressure and the specification of the discharge line of the injector makes it possible to draw the geometry of the injection rate at which fuel is injected from the injector. The fuel injection system employing the means according to a fifth aspect allows the geometry of the injection rate to be drawn in terms of the rising injection rate Qup provided when the needle rises in the injector, the falling injection rate Qdn provided when the needle falls in the injector, and the maximum injection rate Qmax applied when the rising injection rate Qup reaches a maximum injection rate. In other words, for such a low level injection as the rising injection rate, Qup does not reach the maximum injection rate Qmax, the geometry of the injection rate is defined by the triangle specified in terms of the rising injection rate Qup and the falling injection rate Qdn. This results in a triangle having an area corresponding to the request injection quantity Q being expressed by a second order equation in terms of the duration of injection. Accordingly, the drive signal generation timing and the drive signal termination timing can be analytically determined from the triangle to implement the request injection timing and the request injection quantity Q. On the other hand, for such a high level injection as the rising injection rate Qup reaching the maximum injection rate Qmax, the geometry of the injection rate is defined by the trapezoid specified in terms of the rising injection rate Qup, the maximum injection rate Qmax, and the falling injection rate Qdn. This results in a trapezoid having an area corresponding to the request injection quantity Q being expressed by a linear equation in terms of the duration of injection. Accordingly, the drive signal generation timing and the drive signal termination timing can be analytically determined from the trapezoid to implement the request injection timing and the request injection quantity Q. The fuel injection system employing the means according to a sixth aspect determines the drive signal generation timing of the injector to be at a valve opening pressure achieving time Tds before a start point of formation in time of the injection rate against time geometry. The valve opening pressure achieving time (Tds) is measured from a valve opening command being given to the injector to an actual start of fuel injection by the injector. The fuel injection system employing the means according to a seventh aspect determines the valve opening pressure achieving time Tds, the valve closing pressure achieving time Tde1, and the needle rise time Tqr, and then determines the duration Tqf measured from the drive signal generation timing to the drive signal termination timing of the injector by Tds+Tqr−Tde1. The fuel injection system employing the means according to an eighth aspect determines the needle rise time Tqr in terms of the request injection quantity Q, the rising injection rate Qup, and the falling injection rate Qdn. The fuel injection system employing the means according to a ninth aspect determines the valve opening pressure achieving time Tds by the function of a pressure of the high-pressure fuel supplied to the injector and multiple-injection intervals at which fuel is injected separately a multiple number of times in one cycle. The fuel injection system employing the means according to a tenth aspect employs, when correcting for a variation in injection quantity, at least one of the injection parameters (Tds, Qup, Qdn, Qmax, Tde1, Tqr, and Tqf) as an adjustment parameter and stores the adjustment parameter as a learned value to reflect the value on the next injection. This arrangement allows for correction of a variation in injection quantity corresponding to the difference between individual fuel injection systems and the degradation therein. The fuel injection system employing the means according to an eleventh aspect employs, when correcting for a variation in injection quantity, two or more of the two or more injection parameters (Tds, Qup, Qdn, Qmax, Tde1, Tqr, and Tqf) as adjustment parameters and weights the adjustment parameters to correct for the variation in injection quantity. The respective adjustment parameters are stored as a learned value to reflect the value on the next injection. This arrangement allows for correction of a variation in injection quantity corresponding to the difference between individual fuel injection systems and the degradation therein as well as a variation in injection timing (the commencement or termination of injection or both of them). The fuel injection system employing the means according to a twelfth aspect estimates, when correcting for a variation in injection quantity, the variation in injection quantity as being caused by a change in a parameter of a predetermined portion defining a specification of the injector to employ the parameter of the predetermined portion as an adjustment parameter and store the adjustment parameter as a learned value to reflect the value on the next injection. The parameter of a predetermined portion defining the specification of the injector is corrected in this manner, thereby allowing for correction of the injection parameter determined using the parameter of the predetermined portion. That is, the geometry of a corrected injection rate is drawn, thus requiring no additional correction (such as injection quantity or injection timing). To summarize the modes in which the fuel injection system operates, the controller of the fuel injection system determines the geometry defined by a change in injection rate of the injector with respect to time, and the drive signal generation timing and the drive signal termination timing of the injector from the geometry of the injection rate having an area corresponding to the request injection quantity Q. The controller of the fuel injection system determines the geometry defined by a change in needle lift amount of the injector with respect to time and converts the geometry of the needle lift amount to determine the geometry of the injection rate. Then, the drive signal generation timing and the drive signal termination timing of the injector are determined from the geometry of the injection rate having an area corresponding to the request injection quantity Q. The controller of the fuel injection system determines the geometry defined by a change in needle lift amount of the injector with respect to time. Then, the drive signal generation timing and the drive signal termination timing of the injector are determined from the geometry of the needle lift amount having an area corresponding to the request injection quantity Q. Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: FIG. 1 is a graph illustrating relationships between a drive pulse and various injection parameters during a short duration injection pulse of an embodiment of the invention; FIG. 2 is a graph illustrating relationships between a drive pulse and various injection parameters during a long duration injection pulse of an embodiment of the invention; FIG. 3 is a schematic view illustrating a common rail fuel injection system of an embodiment of the invention; FIG. 4 is a cross-sectional view illustrating an injector of an embodiment; and FIG. 5 is a graph of an injection pulse and a drive pulse and how they correspond to an actual injection and an injection rate, respectively, of the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. First Embodiment Now, reference is made to FIGS. 1 to 4 to explain the first embodiment of the present invention, which is applied to a common rail fuel injection system. First, the configuration of the common rail fuel injection system will be explained with reference to FIG. 3. As an example, the common rail fuel injection system is designed to inject fuel into a diesel engine (hereinafter referred to as an engine) 1, and includes a common rail 2, injectors 3, a supply pump 4, and an ECU 5 (abbreviated as Engine Control Unit, corresponding to a controller). The engine 1 has a multiple number of cylinders, each of which experiences an intake, compression, combustion, and exhaust stroke. As an example, FIG. 3 shows a four-cylinder engine, however, the present invention is also applicable to an engine having a different number of cylinders. The common rail 2 is an accumulator vessel for accumulating high-pressure fuel to be supplied to the injector 3. The common rail 2 is connected to the discharge port of the supply pump 4 in order to supply fuel under high pressure via a fuel line (high-pressure fuel passageway) 6 to accumulate pressure in the common rail 2 that corresponds to the fuel injection pressure. Fuel leakage from the injector 3 is returned to a fuel tank 8 via a leakage conduit (fuel return pipe) 7. A relief conduit (fuel return passageway) 9 from the common rail 2 to the fuel tank 8 is provided with a pressure limiter 11. The pressure limiter 11 is a pressure relief valve, which opens when the pressure of fuel exceeds a pressure limit setpoint to reduce the pressure of fuel in the common rail 2 to below the pressure limit setpoint. The injector 3 is mounted to each cylinder of the engine 1 to supply fuel into each cylinder by injection. The injector 3 is connected to the downstream end of a multiple number of high-pressure fuel conduits 10, which branch from the common rail 2, to supply high-pressure fuel accumulated in the common rail 2 to each cylinder by injection. The injector 3 will be described later in more detail. The supply pump 4 is a fuel pump for supplying high-pressure fuel under high pressure to the common rail 2. The supply pump 4 includes a feed pump, for pumping fuel in the fuel tank 8 to the supply pump 4, and a high-pressure pump, for compressing the fuel pumped by the feed pump to a high pressure, to supply the fuel under high pressure to the common rail 2. The feed pump and the high-pressure pump are driven by a common camshaft 12. As shown in FIG. 3, the camshaft 12 is rotatably driven by a crankshaft 13 of the engine 1 or the like. The supply pump 4 is also equipped with a pump control valve (not shown) for adjusting the quantity of fuel to be pumped by the high-pressure pump. The pump control valve is controlled by the ECU 5 to thereby adjust the common rail pressure. The ECU 5 is provided with a microcomputer of a known structure, which includes functions such as a CPU for performing control and operation processing, a storage device (a memory such as a ROM, a stand-by RAM or EEPROM, or RAM) for storing various programs and data, an input circuit, an output circuit, a power supply circuit, an injector drive circuit, and a pump drive circuit. Various operation processings are performed in accordance with the sensor signals (engine parameters, and signals responsive to the driving condition of the driver and the running condition of the engine 1) which are read into the ECU 5. As shown in FIG. 3, the sensors connected to the ECU 5 include an accelerator sensor 21 for sensing the degree of opening of the accelerator, an RPM sensor 22 for sensing the revolutions per minute of the engine, a water temperature sensor 23 for sensing the temperature of the cooling water in the engine 1, a common rail pressure sensor 24 for sensing the pressure of the common rail, and other sensors 25. Now, the fuel injection control according to the first embodiment of the present invention will be described below. In the first embodiment, fuel is injected a multiple number of times during one cycle (multiple injections) to simultaneously provide a high level of prevention with regard to engine vibrations and noises, cleanness of exhaust gas, engine output, and fuel economy. The ECU 5 is designed to determine the request injection timing and the request injection quantity Q in response to the current running condition in accordance with a program stored in the ROM (such as maps) and an engine parameter read into the RAM. The ECU 5 then delivers a drive pulse to the injector 3 so as to obtain the request injection quantity Q at the request injection timing. The control provided by the ECU 5 is explained below. The ECU 5 draws the geometry of the injection rate having an area corresponding to the request injection quantity Q to deliver a drive pulse to the injector 3 so as to obtain the request injection quantity Q at the request injection timing. This geometry is drawn in terms of the injection rate of the injector 3 with respect to time. The ECU 5 determines the drive signal generation timing (drive pulse ON timing) and the drive signal termination timing (drive pulse OFF timing) of the injector 3 from the geometry of the injection rate having an area corresponding to the request injection quantity Q (which is the function of the drive timing calculation means). The geometry of the injection rate is drawn to have the conditions of the pressure (e.g., a common rail pressure Pc) of high-pressure fuel to be supplied to the injector 3 and the specification of the discharge line of the injector 3. The operation principles of the injector 3 will now be explained with reference to FIGS. 1, 2, and 4. As shown in FIG. 4, the injector 3 of this type according to the first embodiment allows an electromagnetic valve 32 to control the pressure of a control chamber (back-pressure chamber) 31 in order to drive a needle 33. As shown in FIGS. 1 and 2, an injection pulse (pulse ON) given by the ECU 5 to the electromagnetic valve 32 allows a valve body (2WV in the figure) 32a of the electromagnetic valve 32 to start to be lifted up and an out-orifice 34 to open at the same time, thereby causing the pressure of the control chamber 31, decompressed by an in-orifice 35, to start decreasing. A decrease in the pressure of the control chamber 31 to that of the valve opening pressure or less causes the needle 33 to start rising. Disengagement of the needle 33 from its nozzle seat 36 causes the nozzle chamber 37 to communicate with an injection hole 38, thereby allowing the fuel supplied under high pressure to the nozzle chamber 37 to be injected from the injection hole 38. The time from the drive pulse ON to the commencement of injection is called the valve opening pressure achieving time Tds. As the needle 33 rises, the injection rate increases. An increase in injection rate is called the rising injection rate Qup. When the rising injection rate Qup reaches the maximum injection rate Qmax, the injection rate will not increase further (see FIG. 2). When the injection pulse given by the ECU 5 to the electromagnetic valve 32 is terminated (pulse OFF), the valve body 32a of the electromagnetic valve 32 starts being directed down. Then, when the valve body 32a of the electromagnetic valve 32 closes the out-orifice 34, the pressure of the control chamber 31 starts increasing. When the pressure of the control chamber 31 increases to the valve closing pressure or higher, the needle 33 starts lowering. The time from the pulse OFF to the commencement of the lowering of the needle 33 is called the valve closing pressure achieving time Tde1. The time from the commencement of the rising to the commencement of the lowering of the needle 33 is called the needle rise time Tqr, and a decrease in injection rate during the lowering of the needle 33 is called the falling injection rate Qdn. The needle 33 lowering to engage the nozzle seat 36 blocks the communication between the nozzle chamber 37 and the injection hole 38, thereby terminating fuel injection from the injection hole 38, that is, the time from the commencement of the lowering of the needle 33 to the termination of injection is called time Tde2. As described above, when the rising injection rate Qup does not reach the maximum injection rate Qmax (e.g., for a short duration injection), a triangular geometry results, as shown in FIG. 1, in terms of the injection rate, that is, the rising injection rate Qup and the falling injection rate Qdn, with respect to time. On the other hand, when the rising injection rate Qup reaches the maximum injection rate Qmax (e.g., for a large level injection), a trapezoidal geometry is produced, as shown in FIG. 2, in terms of the injection rate, that is, the rising injection rate Qup, the maximum injection rate Qmax, and the falling injection rate Qdn, with respect to time. Now, each parameter of the geometry of the injection rate will be explained. (1) When the rising injection rate Qupdoes not reach the maximum injection rate Qmax (e.g., for a short duration injection) and the geometry of the injection rate is a triangle; Rising injection rate Qup=func (Pc, Tint) Falling injection rate Qdn=func (Pc) Needle Rise Time Tqr = 2 Q Q up ( 1 + Q up / Q dn ) [ Equation 1 ] Valve opening pressure achieving time Tds=func (Pc, Tint) Valve closing pressure achieving time Tde1=func (Pc) Injection pulse duration Tqf=Tqr+Tds−Tde1 Needle falling time Tde2=Tqr (Qup/Qdn) (2) When the rising injection rate Qup reaches the maximum injection rate Qmax (e.g., for a long duration injection) and the geometry of the injection rate is a trapezoid; Rising injection rate Qup=func (Pc, Tint) Falling injection rate Qdn=func (Pc) Maximum injection rate Qmax=func (Pc) Needle rise time Tqr=Qdn/(Qup+Qdn)×Q/Qm+½×Qm/Qup [Equation 2] Valve opening pressure achieving time Tds=func (Pc, Tint) Valve closing pressure achieving time Tde1=func (Pc) Injection pulse duration Tqf=Tqr+Tds−Tde1 Needle falling time Tde2=Tqr (Qup/Qdn) In the foregoing, Tint is an interval (injection interval) at which multiple injections are carried out, and the injection pulse duration Tqf corresponds to a period of time from the drive signal generation timing (drive pulse ON timing) to the drive signal termination timing (drive pulse OFF timing) of the injector 3. The “func” indicates a function (having the specified conditions of the discharge line of the injector 3) or a map stored in the storage device (the map being prepared based on the specified conditions of the discharge line of the injector 3), a numerical value being derived from the function or the map. The “Pc” is a common rail pressure read by the common rail pressure sensor 24, the common rail pressure corresponding to the pressure of the high-pressure fuel to be supplied to the injector 3. In the foregoing, the needle rise time Tqr is determined in terms of the request injection quantity Q, the rising injection rate Qup, and the falling injection rate Qdn. That is, it is determined from the relationship between the geometry of the injection rate and the request injection quantity Q. As described above, the valve opening pressure achieving time Tds may be determined from the function of the common rail pressure Pc and the interval Tint, or alternatively from a map (a three-dimensional map of the common rail pressure Pc, the interval Tint, and the valve opening pressure achieving time Tds). That is, a three-dimensional map of the common rail pressure Pc, the interval Tint, and the valve opening pressure achieving time Tds may be pre-stored in a ROM area of the ECU 5. Then, the valve opening pressure achieving time Tds may be determined from the three-dimensional map corresponding to the common rail pressure Pc associated with the running condition and the interval Tint determined by operation. As shown in FIGS. 1 and 2, the ECU 5 determines the ON timing of the drive pulse to be at a valve opening pressure achieving time Tds before the start point of formation in time a1 of the geometry of the injection rate with respect to time. That is, the ON timing of the drive pulse is determined by a1−Tds. As described above, the ON timing of the drive pulse is determined to be at the valve opening pressure achieving time Tds before the injector 3 actually starts to inject fuel, thereby enabling an injection to start at the request injection timing made by the ECU 5. The ECU 5 also determines the injection pulse duration Tqf by adding the needle rise time Tqr to the valve opening pressure achieving time Tds and subtracting the valve closing pressure achieving time Tde1 therefrom. That is, the injection pulse duration Tqf is determined by Tds+Tqr−Tde1. As described above, the interval between the ON and OFF states of the drive pulse is determined by the injection pulse duration Tqf to find the OFF timing of the drive pulse, thereby allowing the injector 3 to actually inject fuel of the request injection quantity Q made by the ECU 5. In the first embodiment, such an example was shown in which the OFF timing of the drive pulse was determined in terms of the injection pulse duration Tqf. However, the OFF timing of the drive pulse may also be determined to be at the valve closing pressure achieving time Tde1 before a point in time a2 at which the pressure of the control chamber 31 reaches the valve closing pressure. That is, the OFF timing of the drive pulse may be determined by a2−Tde1. The OFF timing of the drive pulse may also be determined to be at the valve closing pressure achieving time Tde1 plus the needle falling time Tde2 before an end point of formation in time a3 of the geometry of the injection rate with respect to time. That is, the OFF timing of the drive pulse can be determined by a3−Tde1−Tde2. As described above, the fuel injection system according to the first embodiment determines the ON and OFF timing of the drive pulse from the geometry of the injection rate having an area corresponding to the request injection quantity Q. This permits an operational result (the formation of the geometry of the injection rate) based on a change in valve opening pressure achieving time Tds to be automatically reflected on another operational result, such as the duration from the drive signal generation timing to the drive signal termination timing that is derived from the geometry of the injection rate. That is, adaptation of only the valve opening pressure achieving time Tds that is varied by the effect of pulsation would make it possible to automatically determine the ON and OFF timing of the drive pulse corresponding to the request injection timing and the request injection quantity Q in accordance with the geometry of the injection rate (the aforementioned triangle or trapezoid) determined by the ECU 5. This eliminates the need for the conventional individual correction maps and separate correction operations, thereby making it possible to significantly reduce the time for adaptation required of the ECU 5 as compared with the prior art. Second Embodiment In the first embodiment above, such an example was shown in which the rising injection rate Qup, the falling injection rate Qdn, and the maximum injection rate Qmax were directly determined, which were then used to determine the geometry of the injection rate. The example was also adapted such that the rising injection rate Qup, the falling injection rate Qdn, and the maximum injection rate Qmax were determined using the function or map based on the injector supply pressure (the common rail pressure Pc) and the specification of the injector 3. That is, in the first embodiment above, such an example was shown in which the geometry of the injection rate was directly determined using the function or map based on the injector supply pressure (the common rail pressure Pc) and the specification of the injector 3. In contrast to this, in the second embodiment, a geometry defined by a change in needle lift quantity with respect to time is first determined, and then the geometry of needle lift quantity is converted to determine the geometry of the injection rate. Now, a method for converting the geometry of the needle lift quantity to determine the geometry of the injection rate will be explained below. The injection region is divided into a seat aperture region and an injection hole aperture region. The seat aperture region is a region in which the injection quantity is determined by the supply fuel pressure and between the needle 33 and the nozzle seat 36, or the region of the aforementioned rising injection rate Qup and falling injection rate Qdn. The injection hole aperture region is a region in which the supply fuel pressure and the aperture level of the injection hole 38 determine the injection quantity, or the region of the aforementioned maximum injection rate Qmax. When injection takes place only in the seat aperture region, the geometry of the needle lift quantity (a triangle) is converted into the geometry of the injection rate (a triangle). More specifically, a linear approximation is made to the injection flow rate against needle lift quantity characteristics (or the lift—flow rate characteristics) for an injection rate against needle lift quantity conversion (or the lift—injection rate conversion). This allows for drawing the geometry of the injection rate (a triangle) for the case of the rising injection rate Qup not reaching the maximum injection rate Qmax (e.g., for a short duration injection). When injection is also carried out in the injection hole aperture region in addition to the seat aperture region, the geometry of the needle lift quantity (a trapezoid) is determined with the maximum value of the seat aperture region employed as the value of the injection hole aperture region. Then, the geometry of the needle lift quantity (a trapezoid) is converted into the geometry of the injection rate (a trapezoid). More specifically, a linear approximation is made to the injection quantity against the needle lift quantity characteristics (or the lift—flow rate characteristics) for an injection rate against needle lift quantity conversion (or the lift—injection rate conversion). This allows for drawing the geometry of the injection rate (a trapezoid) for the case of the rising injection rate Qup reaching the maximum injection rate Qmax (e.g., for a large level injection). The geometry of the injection rate determined in this manner can be used to provide the same effects as those of the first embodiment. Third Embodiment The ECU 5 is provided with a correction function for changing the quantity of injection (e.g., a function for correcting for variations between the cylinders) to eliminate a variation in revolutions per minute of the engine when the RPM sensor 22 or the like detects the variation. More specifically, when a variation is detected in the revolutions per minute of the engine, correction is made to the ECU 5 to change the quantity of injection to eliminate the variation. To this end, used as an adjustment parameter is at least one of the injection parameters (for preparing the geometry of the injection rate) consisting of the valve opening pressure achieving time Tds, the rising injection rate Qup, the falling injection rate Qdn, the maximum injection rate Qmax, the valve closing pressure achieving time Tde1, the needle rise time Tqr, and the injection pulse duration Tqf. Then, the correction value of the adjustment parameter is stored as a learned value to reflect the value on the next injection. Of course, when the amount of the variation in the revolutions per minute of the engine is varied, the correction function works to update the correction value of the adjustment parameter in response to the amount of the variation as well as the updated correction value of the adjustment parameter as a learned value, thus there is continuous adjustment to eliminate variations in the revolutions per minute of the engine. The correction function including the learning function makes it possible to prevent deterioration in injection accuracy caused by the difference between individual fuel injection systems (variations between the injectors 3) and by degradation of the individual fuel injection systems (e.g., variations in seat diameter or the diameter of engagement of the needle 33 with the nozzle seat 36). Fourth Embodiment For the correction function according to the third embodiment above, such an example was shown in which correction was made using, as an adjustment parameter, at least one of the injection parameters consisting of the valve opening pressure achieving time Tds, the rising injection rate Qup, the falling injection rate Qdn, the maximum injection rate Qmax, the valve closing pressure achieving time Tde1, the needle rise time Tqr, and the injection pulse duration Tqf. In contrast to this, to correct for a variation in injection quantity, the correction function according to the fourth embodiment employs two or more of the injection parameters as adjustment parameters, while weighting the adjustment parameters for the correction of the variation in injection quantity and storing the respective adjustment parameters as a learned value to reflect the value on the next injection. As a specific example, suppose that when a variation in revolutions per minute of the engine is detected, correction is made to eliminate the variation using as adjustment parameters the three parameters consisting of the valve opening pressure achieving time Tds, the rising injection rate Qup, and the falling injection rate Qdn. In this case, the heaviest weight is assigned to the degree of correction of the valve opening pressure achieving time Tds (e.g., weight 6), while a low weight is assigned to the degree of correction of the rising injection rate Qup and the falling injection rate Qdn (e.g., weight 2, respectively). This arrangement allows for making correction to a variation in injection quantity corresponding to the difference between individual fuel injection systems and degradation thereof as well as in injection timing (the commencement or termination of injection or both of them). Fifth Embodiment For the correction function according to the third and fourth embodiment above, an example was shown in which when a variation in revolutions per minute of the engine was detected, correction was directly made to the value of the injection parameters (the valve opening pressure achieving time Tds, the rising injection rate Qup, the falling injection rate Qdn, the maximum injection rate Qmax, the valve closing pressure achieving time Tde1, the needle rise time Tqr, and the injection pulse duration Tqf) in order to eliminate the variation. To the contrary, when a variation in revolutions per minute of the engine is detected, the correction function according to the fifth embodiment estimates that the variation is caused by a change in the parameter of a predetermined portion defining the specification of the injector 3. Then, the function uses the parameter of the predetermined portion as an adjustment parameter and stores the adjustment parameter as a learned value to reflect the value on the next injection. As a specific example, suppose that a determination is made using the valve opening pressure achieving time Tds=func (Dst, Qin, Qout). In the equation, “func” indicates a function or a map stored in a storage device as described above, Dst is the diameter of the seat (the seat diameter of engagement of the needle 33 with the nozzle seat 36, or an exemplary parameter of a predetermined portion), Qin is the aperture flow rate of the in-orifice 35, and Qout is the aperture flow rate of the out-orifice 34. When a variation in revolutions per minute of the engine is detected, it is estimated that the variation is caused by a change in seat diameter defining the specification of the injector 3, and then the value of the seat diameter Dst is changed. That is, correction is made to the value of the seat diameter Dst in the valve opening pressure achieving time Tds=func (Dst, Qin, Qout), resulting in the value of the valve opening pressure achieving time Tds being corrected. Furthermore, correction is made only once to the value of the seat diameter Dst, thereby causing the value of the other injection parameters prepared using the seat diameter Dst to also be corrected at the same time. The “other injection parameters” include the rising injection rate Qup, the falling injection rate Qdn, but not the valve opening pressure achieving time, Tds. Correction is made to the parameter of a predetermined portion defining the specification of the injector 3, thereby simultaneously correcting an injection parameter that is determined using the parameter of the predetermined portion. That is, since the geometry of a corrected injection rate is drawn, no additional correction needs to be made to the injection quantity or the injection timing. Modified Examples In each of the aforementioned embodiments, such an example was shown in which the effect of pulsation occurring during multiple injections was processed under a light operational load. However, the present invention is not limited to multiple injections but is also applicable to a single injection in which injection is carried out once in a cycle, for example. In multiple injection applications, the invention may be applied such that the injection quantity to be provided in one cycle is divided into generally equal amounts, each to be injected separately in multiple injections. The present invention may also be applied to multiple injections in which the injection to be performed in one cycle is divided into a minor injection and a main injection so as to conduct the minor injection once or multiple times before the main injection. Alternatively, the present invention may also be applied to multiple injections in which the minor injection is conducted once or multiple times after the main injection, or to multiple injections in which the minor injection is conducted once or multiple times before and after the main injection. In each of the aforementioned embodiments, such an example was shown which applied the present invention to the common rail fuel injection system in which fuel leakage occurred during the operation of the injector 3. However, the present invention may also be applied to a common rail fuel injection system of the type that allows a linear solenoid mounted to the injector 3 to directly drive the needle 33 without causing any fuel leakage. That is, the present invention may also be applied to the fuel injection system that incorporates the injector 3 of the type that directly drives the needle 33 by a piezoelectric injector or the like. In each of the aforementioned embodiments, such an example was shown in which the geometry of the injection rate is drawn in terms of the rising injection rate Qup, the falling injection rate Qdn, and the maximum injection rate Qmax that is applied only when the rising injection rate Qup reaches the maximum injection rate. However, the geometry of the injection rate with respect to time can be drawn given that the pressure of the high-pressure fuel to be supplied to the injector 3 and the specification of the discharge line of the injector 3, such as the specification of an injection outlet or the set point of the valve opening pressure, are known. Accordingly, it is also acceptable to determine the geometry of the injection rate in accordance with the pressure of the high-pressure fuel to be supplied to the injector 3 and the specification of the discharge line of the injector 3. In each of the aforementioned embodiments, such an example was shown in which the present invention was applied to the common rail fuel injection system. However, the present invention may also be applied to a fuel injection system that employs no common rail. That is, the present invention can also be applied to a fuel injection system that is used, for example, in a gasoline engine or engine that combusts a fuel other than diesel fuel. The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | <SOH> 2. Background of the Invention <EOH>As an example, reference will be made to a conventional fuel injection system shown in FIG. 5 that employs multiple injections (or multi-stage injections of fuel to be separately carried out a multiple number of times in one cycle). As shown in FIG. 5 , in a multiple number of times of injection in one cycle, the second and subsequent stage injections are affected by the previous injection (due to pulsation that occurs in a line for supplying fuel to the injector), which leads to a variation in injection commencement delay or injection termination delay. This will be described more specifically with reference to the lower portion of FIG. 5 . Suppose that a drive pulse as shown in the lower portion in FIG. 5 is provided to the injector in the absence of pulsation. In this case, the injection rate starts rising from the point in time at which the valve opening pressure achieving time Tds has elapsed after the drive pulse is generated, and starts falling from the point in time at which the valve closing pressure achieving time Tde 1 has elapsed after the drive pulse is terminated. Thus, the geometry drawn in terms of the injection rate takes the shape of a reference triangle, as shown in FIG. 5 . An injection quantity Q′ to be actually injected from the injector is a quantity corresponding to the area of the reference triangle. Suppose that the effect of pulsation causes an increase in fuel pressure to be supplied to the injector. In this case, in general, the valve opening pressure achieving time Tds is reduced by the amount of arrow ( 1 ) of FIG. 5 , while the maximum injection rate is increased as shown by arrow ( 2 ), and the needle falling time Tde 2 is extended as shown by arrow ( 3 ). As a result, the geometry drawn in terms of the injection rate takes the shape of a larger triangle, as shown in FIG. 5 . That is, the injection quantity Q′ that is actually injected from the injector is a quantity corresponding to the area of the larger triangle, thus causing the injection quantity to be larger than the request injection quantity Q. To the contrary, a decrease in fuel pressure to be supplied to the injector due to the effect of pulsation would cause the geometry drawn in terms of the injection rate to be smaller than the reference triangle, thus making the injection quantity less than the request injection quantity Q. The effect of pulsation would also vary the pressure of fuel to be supplied to the injector thereby causing a variation in the valve opening pressure achieving time Tds. This causes a deviation in actual injection timing before or after the request injection start timing made by the controller. In the prior art, independently provided were a correction map for determining the valve opening pressure achieving time Tds varied by pulsation, a correction map for determining the valve closing pressure achieving time Tde 1 varied by pulsation, and a correction map for determining the injection quantity varied by pulsation, in addition to a map for determining a fundamental pulse duration of the injector from the fundamental injection quantity and a common rail pressure. In these respective maps, an independent operation was carried out to correct the output timing of a drive pulse, thereby preventing a variation in injection quantity due to the effect of pulsation (e.g., see Japanese Patent Laid-Open Publication No. Hei 10-266888). In the prior art mentioned above, even to solve a drawback caused by one factor, such as the effect of pulsation, it is necessary to use a number of independent correction maps to separately determine the valve opening pressure achieving time Tds, the valve closing pressure achieving time Tde 1 , and the injection quantity, which are varied by pulsation, and use the resulting values for correction of the output timing of drive pulses. Accordingly, for example, in multi-stage injection, it is necessary to perform an operational step using a number of independent correction maps by the number of the injection stages, thereby imposing a very heavy operational load on a controller. This load is caused by the multiple operation steps of correcting the drive pulse and thus an enormous number of adaptation steps are required for the operational step. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention was developed in view of the aforementioned problems. It is therefore the object of the present invention to provide a fuel injection system that allows for the reduction of the adaptation steps to correct the output duration and timing of a drive pulse for drivingly closing or opening an injector. The fuel injection system employing the means according to a first aspect determines a geometry defined by a change in injection rate of the injector with respect to time, and drive signal generation timing and drive signal termination timing of the injector from the geometry of the injection rate having an area corresponding to the request injection quantity Q. As described above, the fuel injection system employing the means according to the first aspect determines the drive signal generation timing and the drive signal termination timing of the injector from the geometry of the injection rate having an area corresponding to the request injection quantity Q. Accordingly, this permits an operational result (the formation of the geometry of the injection rate) based on a certain factor (e.g., a change in valve opening pressure achieving time Tds) to be automatically reflected on another operational result (such as the drive signal generation timing or the drive signal termination timing that is derived from the geometry of the injection rate). It is thus possible to significantly reduce the adaptation time required of the controller. The fuel injection system employing the means according to a second aspect determines the geometry defined by a change in needle lift quantity of the injector with respect to time and converts the geometry of needle lift quantity to determine the geometry of the injection rate. The fuel injection system employing the means according to a third aspect allows the determination of the geometry of the injection rate by converting the geometry of the needle lift quantity to include dividing an injection region into a seat aperture region and an injection hole aperture region. In the seat aperture region, an injection quantity is determined between a needle and a nozzle seat of the injector, while in the injection hole aperture region, an injection quantity is determined in accordance with an aperture level of an injection hole of the injector. Also included are making a linear approximation of injection flow rate against needle lift quantity characteristics in the seat aperture region for an injection rate against needle lift quantity conversion, and making a linear approximation of injection flow rate against needle lift quantity characteristics in the injection hole aperture region for an injection rate against needle lift quantity conversion. The fuel injection system employing the means according to a fourth aspect allows the geometry of the injection rate to be drawn at least using a pressure at which high-pressure fuel is supplied to the injector and a specification of a discharge line of the injector. That is, using the supply fuel pressure and the specification of the discharge line of the injector makes it possible to draw the geometry of the injection rate at which fuel is injected from the injector. The fuel injection system employing the means according to a fifth aspect allows the geometry of the injection rate to be drawn in terms of the rising injection rate Qup provided when the needle rises in the injector, the falling injection rate Qdn provided when the needle falls in the injector, and the maximum injection rate Qmax applied when the rising injection rate Qup reaches a maximum injection rate. In other words, for such a low level injection as the rising injection rate, Qup does not reach the maximum injection rate Qmax, the geometry of the injection rate is defined by the triangle specified in terms of the rising injection rate Qup and the falling injection rate Qdn. This results in a triangle having an area corresponding to the request injection quantity Q being expressed by a second order equation in terms of the duration of injection. Accordingly, the drive signal generation timing and the drive signal termination timing can be analytically determined from the triangle to implement the request injection timing and the request injection quantity Q. On the other hand, for such a high level injection as the rising injection rate Qup reaching the maximum injection rate Qmax, the geometry of the injection rate is defined by the trapezoid specified in terms of the rising injection rate Qup, the maximum injection rate Qmax, and the falling injection rate Qdn. This results in a trapezoid having an area corresponding to the request injection quantity Q being expressed by a linear equation in terms of the duration of injection. Accordingly, the drive signal generation timing and the drive signal termination timing can be analytically determined from the trapezoid to implement the request injection timing and the request injection quantity Q. The fuel injection system employing the means according to a sixth aspect determines the drive signal generation timing of the injector to be at a valve opening pressure achieving time Tds before a start point of formation in time of the injection rate against time geometry. The valve opening pressure achieving time (Tds) is measured from a valve opening command being given to the injector to an actual start of fuel injection by the injector. The fuel injection system employing the means according to a seventh aspect determines the valve opening pressure achieving time Tds, the valve closing pressure achieving time Tde 1 , and the needle rise time Tqr, and then determines the duration Tqf measured from the drive signal generation timing to the drive signal termination timing of the injector by Tds+Tqr−Tde 1 . The fuel injection system employing the means according to an eighth aspect determines the needle rise time Tqr in terms of the request injection quantity Q, the rising injection rate Qup, and the falling injection rate Qdn. The fuel injection system employing the means according to a ninth aspect determines the valve opening pressure achieving time Tds by the function of a pressure of the high-pressure fuel supplied to the injector and multiple-injection intervals at which fuel is injected separately a multiple number of times in one cycle. The fuel injection system employing the means according to a tenth aspect employs, when correcting for a variation in injection quantity, at least one of the injection parameters (Tds, Qup, Qdn, Qmax, Tde 1 , Tqr, and Tqf) as an adjustment parameter and stores the adjustment parameter as a learned value to reflect the value on the next injection. This arrangement allows for correction of a variation in injection quantity corresponding to the difference between individual fuel injection systems and the degradation therein. The fuel injection system employing the means according to an eleventh aspect employs, when correcting for a variation in injection quantity, two or more of the two or more injection parameters (Tds, Qup, Qdn, Qmax, Tde 1 , Tqr, and Tqf) as adjustment parameters and weights the adjustment parameters to correct for the variation in injection quantity. The respective adjustment parameters are stored as a learned value to reflect the value on the next injection. This arrangement allows for correction of a variation in injection quantity corresponding to the difference between individual fuel injection systems and the degradation therein as well as a variation in injection timing (the commencement or termination of injection or both of them). The fuel injection system employing the means according to a twelfth aspect estimates, when correcting for a variation in injection quantity, the variation in injection quantity as being caused by a change in a parameter of a predetermined portion defining a specification of the injector to employ the parameter of the predetermined portion as an adjustment parameter and store the adjustment parameter as a learned value to reflect the value on the next injection. The parameter of a predetermined portion defining the specification of the injector is corrected in this manner, thereby allowing for correction of the injection parameter determined using the parameter of the predetermined portion. That is, the geometry of a corrected injection rate is drawn, thus requiring no additional correction (such as injection quantity or injection timing). To summarize the modes in which the fuel injection system operates, the controller of the fuel injection system determines the geometry defined by a change in injection rate of the injector with respect to time, and the drive signal generation timing and the drive signal termination timing of the injector from the geometry of the injection rate having an area corresponding to the request injection quantity Q. The controller of the fuel injection system determines the geometry defined by a change in needle lift amount of the injector with respect to time and converts the geometry of the needle lift amount to determine the geometry of the injection rate. Then, the drive signal generation timing and the drive signal termination timing of the injector are determined from the geometry of the injection rate having an area corresponding to the request injection quantity Q. The controller of the fuel injection system determines the geometry defined by a change in needle lift amount of the injector with respect to time. Then, the drive signal generation timing and the drive signal termination timing of the injector are determined from the geometry of the needle lift amount having an area corresponding to the request injection quantity Q. Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. | 20040129 | 20090106 | 20051124 | 63299.0 | 0 | MOULIS, THOMAS N | FUEL INJECTION SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,765,911 | ACCEPTED | Non-volatile zero field splitting resonance memory | A low-volatility or non-volatility memory device utilizing zero field splitting properties to store data. In response to an electrical pulse or a light pulse, in the absence of any externally applied magnetic field, the host material can switch between stable energy-absorbing states based on the zero field splitting properties of the metal ions and the surrounding host material. The invention also includes a device and method for the storage of multiple bits in a single cell using a plurality of metal ion species in a single host material. | 1. A memory cell, comprising: a host material layer, said host material layer exhibiting zero field splitting and being configured to store data as an energy-absorbing state and a lesser-energy-absorbing state; and a first electrode and a second electrode, each being electrically coupled to said host material layer. 2. The memory cell of claim 1, wherein said host material layer incorporates metal ions, said metal ions exhibiting said zero field splitting. 3. The memory cell of claim 1, wherein said lesser-energy-absorbing state is a non-energy-absorbing state. 4. The memory cell of claim 1, wherein said host material layer is organic. 5. The memory cell of claim 1, wherein said host material layer is a polymer. 6. The memory cell of claim 1, wherein said host material layer is inorganic. 7. The memory cell of claim 1, wherein said host material layer is a chalcogenide glass. 8. The memory cell of claim 1, wherein said host material layer is germanium selenide. 9. The memory cell of claim 8, wherein said germanium selenide is Ge40Se60. 10. The memory cell of claim 2, wherein said metal ions comprise ions of a metal selected from the group consisting of Co, Cr, Fe, Mn, Ti, Cu, Zn, V, Cd, and Ni. 11. The memory cell of claim 2, wherein said metal ions comprise Mn+2. 12. The memory cell of claim 1, wherein said host material layer is Ge40Se60 that incorporates about 3 wt. % Mn+2 as metal ions. 13. The memory cell of claim 2, wherein said host material layer and said metal ions are configured to absorb a detectable amount of energy corresponding to a separation in electron spin level energy of said metal ions at zero field. 14. The memory cell of claim 2, wherein said host material layer and said metal ions are configured to absorb about 0.03 cm−1 to about 3.3 cm−1 when said memory device is programmed to said energy-absorbing state. 15. The memory cell of claim 2, wherein said hose material layer and said metal ions are configured to absorb about 0.33 cm−1 when said memory device is programmed to said energy-absorbing state. 16. The memory cell of claim 1, wherein one of said first and second electrodes is manganese and the other is tungsten. 17. The memory cell of claim 1, wherein said device is configured to be programmed to said energy-absorbing state by a light pulse. 18. The memory cell of claim 1, wherein said device is configured to be programmed to said energy-absorbing state by an electrical pulse. 19. A zero-field splitting memory device, comprising: a first electrode; a germanium selenide layer in contact with said first electrode, said germanium selenide layer having a stoichiometry of GexSe100-x; metal ions incorporated into said germanium selenide layer, wherein said germanium selenide and said metal ions are configured to absorb a detectable amount of energy when said memory device is programmed to an energy-absorbing state; and a second electrode in contact with said germanium selenide layer. 20. The zero-field splitting memory device of claim 19, wherein said first electrode, said germanium selenide layer, and said second electrode are vertically stacked. 21. The zero-field splitting memory device of claim 19, wherein said germanium selenide is Ge40Se60 and said metal ions comprise Mn+2. 22. The zero-field splitting memory device of claim 21, wherein said Ge40Se60 incorporates about 3 wt. % Mn+2. 23. The zero-field splitting memory device of claim 22, wherein said detectable amount of energy is about 0.03 cm−1 to about 3.3 cm−1. 24. The zero-field splitting memory device of claim 19, wherein said germanium selenide layer is about 100 Å to about 2,000 Å in thickness. 25. The zero-field splitting memory device of claim 19, wherein said metal ions comprise ions of a metal selected from the group consisting of Co, Cr, Fe, Mn, Ti, Cu, Zn, Ni, V, Cd, and combinations thereof. 26. The zero-field splitting memory device of claim 19, wherein said device comprises a plurality of memory cells each comprising a respective said first electrode, said germanium selenide layer, and said second electrode. 27. A multiple-bit memory device, comprising: a host material incorporating a plurality of different metal ion types, said each of said different metal ion types exhibiting zero field splitting, said host material and said different metal ion types being configured to store data as a plurality of energy-absorbing states and a non-energy-absorbing state; and a first electrode and a second electrode, each being electrically coupled to said host material. 28. The multiple-bit memory device of claim 27, wherein said first electrode, said host material, and said second electrode are stacked vertically. 29. The multiple-bit memory device of claim 27, wherein said host material is organic. 30. The multiple-bit memory device of claim 27, wherein said host material is a polymer. 31. The multiple-bit memory device of claim 27, wherein said host material is inorganic. 32. The multiple-bit memory device of claim 27, wherein said host material is a chalcogenide glass. 33. The multiple-bit memory device of claim 27, wherein said host material is germanium selenide. 34. The multiple-bit memory device of claim 33, wherein said germanium selenide is Ge40Se60. 35. The multiple-bit memory device of claim 27, wherein said plurality of different metal ion types comprise ions of at least two metal species selected from the group consisting of Co, Cr, Fe, Mn, Ti, Cu, Zn, V, Cd, and Ni. 36. The multiple-bit memory device of claim 27, wherein said plurality of different metal ion types comprise Mn+3. 37. The multiple-bit memory device of claim 27, wherein said host material is Ge40Se60 incorporating Mn+2 and Cu+2 as said plurality of different metal ion types. 38. The multiple-bit memory device of claim 27, wherein said host material and said plurality of different metal ion types are configured to absorb a detectable amount of energy corresponding to a separation in energy of the electron spin levels of each of said plurality of different metal ion types at zero field. 39. The multiple-bit memory device of claim 27, wherein said host material and said metal ions are configured to absorb about 0.03 cm−1 to about 3.3 cm−1 when said memory device is programmed to one of said plurality of energy-absorbing states and a different amount of energy at a different one of said plurality of energy-absorbing states. 40. The multiple-bit memory device of claim 27, wherein said device is configured to be programmed to said plurality of energy-absorbing states by light pulses. 41. The multiple-bit memory device of claim 27, wherein said device is configured to be programmed to said plurality of energy-absorbing states by electrical pulses. 42. A processor-based device, comprising: a processor; and a memory cell, comprising: a host material incorporating metal ions, said metal ions exhibiting zero field splitting and said host material being configured to store data as an energy-absorbing state and a non-energy-absorbing state; and a first electrode and a second electrode, each being electrically coupled to said host material. 43. The processor-based device of claim 42, wherein said metal ions comprise Mn+2. 44. The processor-based device of claim 41, wherein said host material is Ge40Se60 incorporating about 3 wt. % Mn+2 as said metal ions. 45. The processor-based device of claim 42, wherein said host material and said metal ions are configured to absorb a detectable amount of energy corresponding to a separation in the electron spin level energy of said metal ions at zero field. 46. The processor-based device of claim 42, wherein said host material and one of said plurality of different metal ion types are configured to absorb about 0.03 cm−1 to about 3.3 cm−1 when said memory device is programmed to said energy-absorbing state. 47. A method of operating a memory device, comprising: providing a memory device comprising a host material which incorporates metal ions exhibiting zero field splitting; programming said memory device to an energy-absorbing state corresponding to a separation of spin states of said metal ions at zero magnetic field; and reading said memory device by sensing the absorption or transmission of a read energy pulse through said host material. 48. The method of claim 47, wherein said host material comprises an organic ligand. 49. The method of claim 47, wherein said host material comprises a polymer. 50. The method of claim 47, wherein said host material comprises an inorganic ligand. 51. The method of claim 47, wherein said host material comprises a chalcogenide glass. 52. The method of claim 47, wherein said host material comprises germanium selenide. 53. The method of claim 47, wherein said host material comprises Ge40Se60 glass. 54. The method of claim 47, wherein said metal ions comprise ions of a metal selected from the group consisting of Co, Cr, Fe, Mn, Ti, Cu, Zn, Ni, V, Cd, and combinations thereof. 55. The method of claim 47, wherein said metal ions comprise Mn+2. 56. The method of claim 47, wherein said programming said memory device comprises applying a write voltage to said host material. 57. The method of claim 47, wherein said programming said memory device comprises applying a light pulse to said host material. 58. The method of claim 47, wherein said reading said memory device comprises applying energy to said host material without changing the programming of said memory device. 59. The method of claim 47, wherein said reading said memory device comprises applying energy to said host material in the microwave frequency range. 60. The method of claim 47, wherein said reading said memory device comprises applying an energy pulse to said host material of at least about 0.03 cm−1. 61. The method of claim 47, further comprising programming said memory device to a non-energy-absorbing state after reading. 62. A method of operating a multiple-bit memory cell, comprising: providing a memory cell comprising a host material which incorporates a plurality of metal ion species, each said species exhibiting zero field splitting; programming said memory cell to at least one of a plurality of energy-absorbing states, each said energy-absorbing state corresponding to a separation of spin states of a respective one of said plurality of metal ion species at zero magnetic field; and reading said memory device by sensing the absorption or transmission of one of a plurality of read energy pulses through said host material, said one read energy pulse corresponding to said respective one metal ion species. 63. The method of claim 62, wherein said host material comprises an organic ligand. 64. The method of claim 62, wherein said host material comprises a polymer. 65. The method of claim 62, wherein said host material comprises an inorganic ligand. 66. The method of claim 62, wherein said host material comprises a chalcogenide glass. 67. The method of claim 62, wherein said host material comprises germanium selenide. 68. The method of claim 62, wherein said host material comprises Ge40Se60 glass. 69. The method of claim 62, wherein said plurality of metal ion species comprises ions of at least two metals selected from the group consisting of Co, Cr, Fe, Mn, Ti, Cu, Zn, V, Cd, and Ni. 70. The method of claim 62, wherein said respective one metal ion species is Mn+2. 71. The method of claim 62, wherein a second respective metal ion species is Cu+2. 72. The method of claim 62, wherein said programming said memory cell comprises applying a write voltage to said host material. 73. The method of claim 62, wherein said programming said memory cell comprises applying a light pulse to said host material. 74. The method of claim 62, wherein said reading said memory cell comprises applying energy to said host material without changing the programming of said memory device. 75. The method of claim 62, wherein said reading said memory cell comprises applying energy to said host material in the microwave frequency range. 76. The method of claim 62, wherein said reading said memory cell comprises applying an energy pulse to said host material of at least about 0.03 cm−1 for said respective one metal ion species. 77. The method of claim 62, further comprising programming said memory cell to a non-energy-absorbing state after reading. | The invention disclosed in this application is related to the invention disclosed by U.S. patent application ______ (Attorney Docket No. M4065.1009/P1009), filed concurrently with this application by Kristy A. Campbell and Terry L. Gilton. The entirety of this related application is hereby incorporated by reference herein in its entirety. FIELD OF THE INVENTION The invention relates to memory devices utilizing zero field splitting parameters and methods of making and using such memory devices. BACKGROUND Integrated circuit designers have always sought the ideal semiconductor memory: a device that is randomly accessible, can be written or read very quickly, is non-volatile, but indefinitely alterable, consumes little power, and is scalable. The search for such devices has led to investigations into atomic-level properties of materials for switching and memory applications. Studies have been conducted into electron spin transistors and memory components. Even in the absence of a magnetic field, some metal ions exhibit splitting of the electron spin energy levels. This is referred to as zero field splitting. Zero field splitting is different from Zeeman splitting (i.e., separation of the electron spin energy levels in the presence of an externally applied magnetic field). The difference being that some molecules may exhibit splitting of the electron energy levels at zero externally applied magnetic field, due in part, to the natural crystal fields present around a metal ion (in the case of molecules with transition metal ions) or to spin-spin coupling within a molecule or between molecules. Molecules with transition metals (e.g., Mn, V, Fe, Co, Cr, Ni, Cu, Zn, Cd, and others) are quite frequently paramagnetic and may have electron spin energy levels at zero magnetic field with an energy splitting between levels for which a spin transition is allowed that is within a range detectable with microwave radiation. For example, as shown in FIG. 1, Mn+3 ions have a spin system with an effective spin S=2, with a positive zero field splitting value. The inset portion of FIG. 1 is an expanded view of the Ms=±2 energy levels in the region of observed parallel mode electron paramagnetic resonance transitions (indicated by the double arrows). Analytical techniques, such as microwave spectroscopy or electron paramagnetic resonance (EPR) spectroscopy can identify molecular systems that exhibit zero field splitting properties. Spin-spin interactions occur when there is at least one unpaired electron interacting with another unpaired electron (S greater than or equal to 1, where S is the effective spin). An example molecular system that could give rise to this situation includes a molecule containing Mn+3, which has a total spin S=2 (e.g., the molecule Mn(salen)). In this case, there are 4 unpaired electrons interacting with each other. Microwave absorption spectroscopy has been used to identify atomic properties of chemical species. Microwave absorption has been shown to be a viable means of determining energy absorption at frequencies corresponding to the zero field splitting value of the absorbing material. It would be advantageous to utilize the zero field splitting properties of ions as a memory device. It would be additionally advantageous if such a memory device was non-volatile or semi-volatile, operated at speeds necessary for present memory functions, and could be scaled to sub-micron sizes. SUMMARY An exemplary embodiment of the invention provides a low-volatility or non-volatile memory cell utilizing the zero field splitting properties of a material to store data. The memory cell may incorporate at least one transition metal ion species. In response to an energy pulse, e.g., electrical or optical, the host material can switch between energy absorbing and non-energy absorbing (or less energy absorbing) states based on the zero field splitting properties of the material induced by the applied signal. Exemplary host material and metal ion combinations include chalcogenide glass with manganese ions, standard float glass (e.g., Na2O-CaO-MgO-SiO2) with ions (e.g., Mn ions), perovskite (e.g., CaTiO3 and MgSiO3) materials with manganese ions, porphyrins with manganese or zinc, or ferrocenes with ion species. Another exemplary embodiment of the invention provides a memory cell, which can store multiple bits of data using a plurality of metal ion species in a single host material. These and other features of exemplary embodiments of the invention will be more apparent from the following detailed description and drawings which illustrate the various embodiments. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an energy level diagram of an S=2 system illustrating zero field splitting for a transition metal ion species. FIG. 2 is an illustration of a cross-section of a memory cell in accordance with an exemplary embodiment of the invention; FIG. 3 is a graph showing the low field signal where zero field splitting may be observed in an exemplary embodiment of the invention; FIG. 4 is a representative portion of a memory array incorporating memory cells in accordance with the invention; and FIG. 5 is a representation of a processor system employing a memory device incorporating exemplary embodiments of memory cells in accordance with the invention. DETAILED DESCRIPTION In the following detailed description, reference is made to the accompanying drawings, which are a part of the specification, and in which is shown by way of illustration various embodiments whereby the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to make and use the invention. It is to be understood that other embodiments may be utilized, and that structural, logical, and electrical changes, as well as changes in the materials used, may be made without departing from the spirit and scope of the present invention. Additionally, certain processing steps are described and a particular order of processing steps is disclosed; however, the sequence of steps is not limited to that set forth herein and may be changed as is known in the art, with the exception of steps or acts necessarily occurring in a certain order. The terms “wafer” and “substrate” are to be understood as interchangeable and as including any foundation suitable for supporting a memory element of the invention. For example, the substrate can be silicon, silicon-on-insulator (SOI), silicon-on-sapphire (SOS), doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor, conductor, or insulator structures. Furthermore, when reference is made to a “wafer” or “substrate” in the following description, previous process steps may have been utilized to form regions, junctions or material layers in or on the base structure or foundation. In addition, the semiconductor substrate need not be silicon-based, but could be based on silicon-germanium, germanium, gallium arsenide, or other known semiconductor materials. Further, the substrate need not be semiconductor-based at all, but can be any material suitable for supporting an integrated circuit memory structure, for instance, polymer, glass, metals, insulated metals, ceramics, and other materials. The invention utilizes zero field splitting (ZFS) properties of certain metal ions to form a memory cell. Transition metal ions, such as ions of Co, Cr, Fe, Mn, Ti, Cu, Zn, V, Cd, and Ni, and others, are preferred and can be added to a host material, such as an organic molecular matrix or an inorganic matrix. The selection of the metal ions and the host material determines the zero field splitting energy; the host material may or may not play a role in the zero field splitting properties of the ions in memory operation. The selection of these ions and host materials should result in microwave absorption energies of about 0.03 cm−1 to 3.3 cm−1 at zero field to satisfy requirements for memory state sensing. The separation of spin states in the metal ions within the host material at zero magnetic field should be be small enough to be able to utilize the energy available on a standard semiconductor chip. The host material, if organic, can be polymer based or porphyrin based. If the host material is inorganic, it may be a chalcogenide glass, e.g., arsenic selenide or germanium selenide, a semiconductor, or a silicate, for example. Now referring to the figures, where like reference numbers designate like elements, FIG. 2 shows a simplified illustration of a specific memory cell construction in accordance with an exemplary embodiment of the invention. The memory cell 10 is shown as supported by a substrate 12, which may be silicon-based, but as indicated above, the substrate can be any of a number of materials. The substrate 12 can be formed or provided as is known in the art by conventional means, depending on its composition. An optional insulating layer 14 is provided over the substrate 12 if it is semiconductor-based. The optional insulating layer 14 can be, for example, silicon oxide or silicon nitride, and can be formed by CVD (chemical vapor deposition), sputtering, oxidation of the substrate 12, or other known techniques. Over the optional insulating layer 14, or substrate 12 if that layer 14 is excluded, is provided an electrode 16 of a conductive material. The conductive material for the electrode 16 can be any of a number of materials, including, but not limited to, tungsten, tungsten nitride, aluminum, copper, doped polysilicon, nickel, titanium, and platinum. The electrode 16 material can be deposited by CVD, PECVD (plasma enhanced chemical vapor deposition), sputtering, plating, or other known techniques, and the electrode 16 can thereafter be defined by patterning and etching, if desired. Over and electrically coupled to the electrode 18 is deposited a layer of host material 18, which incorporates metal ions, such as Mn+2, for example. The host material 18 can be an organic or inorganic molecular matrix (as indicated above) and can be formed by blanket deposition techniques, which may be followed by patterning and etching if desired, or, alternatively, may be formed by an in-via process; either deposition process may include CVD, sputtering, co-sputtering, thermal evaporation, or other known techniques. The host material 18 can be about 100 Å to about 2,000 Å thick. For example, one suitable and exemplary host material 18 is a GexSe100-x glass, for example, a Ge40Se60 glass. Preferably, the glass and ions (e.g., Mn+2 ions, which may be provided as MnSe) are deposited together by cosputtering or co-evaporation. In another method, the glass is first deposited, for example, by sputtering, and then a layer of ions is formed over the Ge40Se60 host material 18, for example, by sputtering or thermal evaporation. The ions can be incorporated into the host material 18 by photodoping or thermal diffusion, or by other means. If the host material 18 itself exhibits zero field splitting properties, the step of adding ions may be omitted. Depending on the selection of host material 18 and metal ion pairing, the host material 18 can incorporate from less than about 0.3% to up to about 10% (by weight) metal ions. About 1 wt. % ion concentration is preferred. A second electrode 20 is next deposited over the ion-doped host material 18. The second electrode 20 can be of the same or similar materials as the first electrode 16 and can be formed by the same or similar techniques. The memory device 10 stack can be surrounded by an insulating material 22, such as BPSG (borophosphosilicate glass) or polyimide, and the wafer can be planarized by CMP (chemical mechanical polishing) using the top electrode 20 as a stop, if desired. The memory device 10 shown in FIG. 2 is representative of one of a plurality of such devices that can be arranged in a memory array. The Mn+2 ions in the above-described exemplary Ge40Se60 glass enable the host material 18 to display a relatively large microwave absorption at zero field, which enables the device to store data as energy absorption states. A memory device in accordance with this exemplary embodiment can absorb about 0.33 cm−1 of energy of a potential pulse having a rise time of about 35 picoseconds and a frequency of about 9.68 GHz. As shown by the graph in FIG. 3, the zero field splitting absorption is observed at relatively low field signal in the structure of this embodiment. The germanium selenide stoichiometry plays a role in the functioning of this exemplary cell, with the Ge40Se60 glass being preferred over other germanium selenide stoichiometries. Other glass types and stoichiometries can be used in the invention, however. In the embodiment discussed in the preceding paragraphs in relation to FIG. 2, the first electrode 16 can comprise manganese. The second electrode 20 can be tungsten. These electrodes 16 and 20 are not limited to such materials, however. Other conductive materials such as doped polysilicon, titanium, aluminum, copper, silver, platinum, nickel, and conductive nitrides can be used as well. Other combinations of metal ions and host materials 18 can also be used for a memory device in accordance with the invention. As previously indicated, such combinations should be able to absorb a detectable amount of energy when in a programmed state. For example, a standard float glass doped with less than about 1% Mn+2, Mn+3, or Fe+3 has been shown to absorb a detectable amount of energy in the microwave frequency range. Float glass can comprise Na2O-CaO-MgO-SiO2, and the metal ions can be incorporated into the glass as about 1 wt. % MnO2 or Fe2O3. Additionally, borosilicate glasses doped with Cu, Ni, Co, and Fe in high concentrations (greater than about 10%) exhibit detectable non-resonant microwave absorption at zero field. The energy absorption characteristics of these alternative host material/metal ion combinations at zero magnetic field have been known in the art, but never utilized as part of a memory device. Other examples of materials that could be engineered to contain transition metals that could be oxidized/reduced by applied potentials or light to exhibit zero field splitting memory behavior include porphyrins, ferrocenes, and perovskites. As shown in FIG. 4, the memory cells 10 of the invention can be utilized in a memory array by being formed between conductive intersecting column lines 30 and row lines 32. At each intersection is located the host material 18 comprising metal ions. When the host material 18 is of the appropriate composition (e.g., the correct matrix material supporting the correct ions and ligands), it can be written, read, and erased in a non-volatile manner for operation as a memory device as discussed herein. A memory cell in accordance with an exemplary embodiment of the invention stores information as a stable energy absorption state; which is one of two states, the other being a stable non-energy-absorbing state. The energy absorbing property of the memory cell should be sufficient to absorb a detectable amount of an energy (e.g., electrical or optical) impulse at a bandwidth corresponding to the splitting at zero field of the ions in the host material. Energy, bandwidth frequency, and pulse rise time are interrelated variables relating to the programming of the memory cell. These variables are interrelated in general accordance with the following formulas: Bandwidth frequency ( Hz ) ≈ 0.35 pulse rise time ( seconds ) ( 1 a ) Energy ( cm - 1 ) ≈ Bandwidth frequency ( Hz ) 3 × 10 10 ( cm / s ) ( 1 b ) Although the two memory states of the memory cells of the invention have been described as an energy-absorbing state and a non-energy-absorbing state, the invention is not limited to such states. Two energy-absorbing states may also be used, where the amount of energy absorption each state exhibits is great enough for individual detection and also allows effective differentiation between the two states. Writing (as well as erasing) the memory cells can be accomplished by three phenomena: (1) changing the oxidation state of the metal ions of the cell; (2) changing the ligand field environment of the metal ions; each induced either by using a voltage potential or light impulse; or (3) a combination of (1) and (2). Either of these inducement techniques can change the zero field splitting parameters of the metal ions in a host material 18. The exemplary memory device of the invention can be written by a potential pulse as already discussed. For example, as shown in FIG. 4, a column line 30 is charged with a programming potential while an intersecting row line 32a is grounded. The memory cell 10a at the intersection of the column line 30 and row line 32a is then programmed (e.g., by redox reaction or ligand field change) to the stable energy-absorbing memory state from a stable non-energy-absorbing state. The specific mechanism enabling the memory cell to switch between energy-absorbing and non-energy-absorbing states will vary depending upon the way the metal ion is altered. Examples include a change in oxidation state of the ions (e.g., Mn+2) within the host material (e.g., Ge40Se60) or because of an alteration of the distribution of molecular species within the memory element of the device such that the metal ions are associated with a charged ligand field environment around the ion. Under the oxidation theory, the metal ions of the host material may form a redox pair, such as Mn+2/Mn+3, Cu+2/Cu+1, or Fe+2/Fe+3, which permits energy absorption within the cell. Under the altered ligand theory, the ligand field around the metal ions may undergo a structural change within the memory cell. For example, if a potential applied in a specific direction across the cell causes a rearrangement in the molecular matrix or if the metal ions redistribute non-homogeneously and see more spin-spin interactions (electrons interacting with each other) due to ion proximity, energy absorption can be enabled or disabled within the cell. Because the memory cell's ability to store data is based on a changeable physical property of the cell, the memory cell can be non-volatile, or at least has very low volatility compared with prior art memory technologies such as DRAM. For example, if the programming mechanism is based on a redox reaction, once the potential applied across the cell generates a larger distribution of one redox state of the metal ions, removal of the potential does not initiate a reverse redox reaction. Likewise, a rearrangement of the molecular matrix remains until another input of energy changes the matrix. After programming, the memory device can be returned to its original energy absorption state. One method of turning off programmed devices is by applying a reverse voltage potential relative to the programming potential of the stimulation pulse. Another method is by utilizing a light pulse. The programmed state of the memory cell can be read, preferably, by sensing the absorption or transmission of energy from a read electrical pulse applied to the cell. After programming a cell to an energy-absorbing state, the metal ions of the cell have a zero field interaction, which results in the metal ions being able to absorb a detectable amount of energy corresponding to the splitting at zero field. If the pulse rise time corresponds to the separation in energy of the electron spin levels at zero field, the signal (or at least a detectable portion thereof) is absorbed by the memory cell and a reduced or absent energy transmission can be sensed by read circuitry. However, if no energy is absorbed because the cell is not programmed to an energy-absorbing state, the energy applied to the cell remains largely intact and can be sensed by read circuitry as corresponding to the non-programmed state of the cell. The energy pulse rise time of the read signal is selected (in accordance with Equations (1a) and (1b)) so that a non-programmed cell does not affect the pulse, but a programmed cell absorbs at least a detectable amount of the transmitted energy. Pulse rise times are specific to the zero field splitting parameters of the molecular system. Pulse rise times in accordance with the exemplary embodiments of the invention (FIG. 2) described above should be about 380 picoseconds to less than 4 picoseconds in order to correspond to the separation in electron spin level energy at zero field of the metal ions used in the memory cells; Mn+2, Cu+2, and Fe+2 being examples. The memory device's access speed is limited only by the speed of the access electronics. A memory cell 10a can be addressed for reading by a read pulse input at the column line 30 (with row line 32a grounded). As the pulse propagates down the column line it is absorbed by the memory cell 10a host material 18 if: (1) the host material 18 is in a zero field splitting state; and (2) the row line 32a at the address is grounded. The memory cell 10a is read by sense circuitry 34 in electrical communication with the column line 30 according to the amount of the column line 30 pulse absorbed by the memory cell 10a. In accordance with another embodiment of the invention, the memory cells 10 can be induced to change state by a light pulse. The light pulse may either make the cells permanently change state (e.g., to an energy-absorbing state) for a write-once device, or a second wavelength of light (or some other energy input) could reverse the state written by the first wavelength (e.g., to a non-energy-absorbing state), making for a non-volatile memory (e.g., random access memory). The light pulse can induce an oxidation state change in the memory cells 10. Physical changes in the glass matrix host material 18 system or molecular conformal changes may occur. In another embodiment in accordance with the invention, the host material 18 incorporates multiple transition metal ion species (more than one ion type) to make a memory cell 10 having a multi-state zero field splitting resonance memory, which is capable of storing multiple bits. The basic structure of such a memory cell 10 can be like that shown in FIG. 2 and described above. However, where the host material 18 of the embodiment described in accordance with FIG. 2 is doped only with one metal ion species, the host material 18 of this embodiment incorporates at least two metal ion species, for example, one ion can be Mn+2 and another can be Cu+2. Both can be incorporated in a Ge40Se60 host material. This embodiment is capable of multiple oxidation states or multiple configurations which have different zero field splitting parameters. Because each transition metal ion (e.g., ions of Mn, Ti, Co, Cr, Cu, Zn, Ni, Fe, Cd, V, and others) has a different zero field splitting energy in the matrix, each programmed state relating to the different ion types can be accessed for a reading operation using a different electrical energy pulse with a rise time corresponding to the energy splitting of a particular ion. For example, a pulse corresponding to a zero field splitting energy of 0.35 cm−1 may be used to read a bit corresponding to Mn+3 ions, but a pulse of greater or lesser magnitude and different rise time may be used for reading a bit stored by Cu+2, where the latter pulse would have no effect on the bit stored by the Mn+3 ion because rise times are coordinated with the different ion species. A single memory cell 10 can therefore contain a plurality of independent memory states, which can each be independently read by changing the rise time of the read pulse. As with other embodiments discussed above, the memory cells 10 of this embodiment can be programmed by either application of a light pulse of a certain wavelength or by application of a potential across the memory cell 10. The ions of different metal species may respond to a programming input with either an oxidation state change or a ligand field rearrangement, as discussed. In this embodiment, it is possible that programming for an ion species with a higher potential programming needs could affect the programmed state of an ion species with lower potential programming needs. Therefore, there should be an order in programming through the various ion species types that takes this into consideration. It is also possible to use various combinations of electrical and light pulses to program the memory cells. The reading of memory states would be independent because pulse rise times used for reading the various ions of a memory cell would be specific to individual ion types and would have no effect on other ion types since these rise times can be correlated to the zero field splitting energy. FIG. 5 shows a typical processor-based system 400, which includes a memory circuit 448, for example, a programmable RAM, employing memory devices having memory cells 10 constructed in accordance with the invention. A processor system, such as computer system, generally comprises a central processing unit (CPU) 444, such as a microprocessor, a digital signal processor, or other programmable digital logic devices. Such devices communicate with an input/output (I/O) device 446 over a bus 452. The memory 448 communicates with the system over the bus 452, typically by a memory controller. In the case of a computer system, the processor may include peripheral devices, such as a disk drive 454 and a CDROM drive 456, which also communicate with the CPU 444 over the bus 452. Memory 448 is preferably constructed as an integrated circuit, which includes one or more memory devices having memory cells 10. If desired, the memory 448 may be combined with the processor, for example CPU 444, in a single integrated circuit. The processes and devices described above are merely illustrative of but a few of the preferred methods and devices that could be used and produced in accordance with the invention. The above description and drawings illustrate embodiments, which achieve the objects, features, and advantages of the invention. However, it is not intended that the invention be strictly limited to the above-described and illustrated embodiments. Any modifications of the invention that come within the spirit and scope of the following claims should be considered part of the invention. What is claimed as new and desired to be protected by Letters Patent of the United States is: | <SOH> BACKGROUND <EOH>Integrated circuit designers have always sought the ideal semiconductor memory: a device that is randomly accessible, can be written or read very quickly, is non-volatile, but indefinitely alterable, consumes little power, and is scalable. The search for such devices has led to investigations into atomic-level properties of materials for switching and memory applications. Studies have been conducted into electron spin transistors and memory components. Even in the absence of a magnetic field, some metal ions exhibit splitting of the electron spin energy levels. This is referred to as zero field splitting. Zero field splitting is different from Zeeman splitting (i.e., separation of the electron spin energy levels in the presence of an externally applied magnetic field). The difference being that some molecules may exhibit splitting of the electron energy levels at zero externally applied magnetic field, due in part, to the natural crystal fields present around a metal ion (in the case of molecules with transition metal ions) or to spin-spin coupling within a molecule or between molecules. Molecules with transition metals (e.g., Mn, V, Fe, Co, Cr, Ni, Cu, Zn, Cd, and others) are quite frequently paramagnetic and may have electron spin energy levels at zero magnetic field with an energy splitting between levels for which a spin transition is allowed that is within a range detectable with microwave radiation. For example, as shown in FIG. 1 , Mn +3 ions have a spin system with an effective spin S=2, with a positive zero field splitting value. The inset portion of FIG. 1 is an expanded view of the Ms=±2 energy levels in the region of observed parallel mode electron paramagnetic resonance transitions (indicated by the double arrows). Analytical techniques, such as microwave spectroscopy or electron paramagnetic resonance (EPR) spectroscopy can identify molecular systems that exhibit zero field splitting properties. Spin-spin interactions occur when there is at least one unpaired electron interacting with another unpaired electron (S greater than or equal to 1, where S is the effective spin). An example molecular system that could give rise to this situation includes a molecule containing Mn +3 , which has a total spin S=2 (e.g., the molecule Mn(salen)). In this case, there are 4 unpaired electrons interacting with each other. Microwave absorption spectroscopy has been used to identify atomic properties of chemical species. Microwave absorption has been shown to be a viable means of determining energy absorption at frequencies corresponding to the zero field splitting value of the absorbing material. It would be advantageous to utilize the zero field splitting properties of ions as a memory device. It would be additionally advantageous if such a memory device was non-volatile or semi-volatile, operated at speeds necessary for present memory functions, and could be scaled to sub-micron sizes. | <SOH> SUMMARY <EOH>An exemplary embodiment of the invention provides a low-volatility or non-volatile memory cell utilizing the zero field splitting properties of a material to store data. The memory cell may incorporate at least one transition metal ion species. In response to an energy pulse, e.g., electrical or optical, the host material can switch between energy absorbing and non-energy absorbing (or less energy absorbing) states based on the zero field splitting properties of the material induced by the applied signal. Exemplary host material and metal ion combinations include chalcogenide glass with manganese ions, standard float glass (e.g., Na 2 O-CaO-MgO-SiO 2 ) with ions (e.g., Mn ions), perovskite (e.g., CaTiO 3 and MgSiO 3 ) materials with manganese ions, porphyrins with manganese or zinc, or ferrocenes with ion species. Another exemplary embodiment of the invention provides a memory cell, which can store multiple bits of data using a plurality of metal ion species in a single host material. These and other features of exemplary embodiments of the invention will be more apparent from the following detailed description and drawings which illustrate the various embodiments. | 20040129 | 20060912 | 20050804 | 97617.0 | 0 | NGUYEN, THINH T | NON-VOLATILE ZERO FIELD SPLITTING RESONANCE MEMORY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,766,165 | ACCEPTED | Synthetic urine and method of manufacturing same | A synthetic urine solution and method of its manufacture are disclosed. The solution includes water having a pH between 3 and 10. The solution further includes creatinine and means for removing bacteria from the solution so as to control or eliminate sepsis of the urine solution, preferably through the use of biocide. The solution exhibits a specific gravity of from 1.005 g/cm3 to 1.025 g/cm3. Additional compounds may also be included to further enhance the aesthetics or apparent authenticity of the synthetic urine produced according to this invention. | 1. A synthetic urine solution consisting essentially of: water having a pH between 3 and 10; creatinine and a biocide, said creatinine and biocide dissolved within said water to form a solution exhibiting a specific gravity and said creatinine and biocide selected in relative concentrations to minimize sepsis; and at least one dissociated ionic compound also dissolved within said solution to adjust the specific gravity of the solution to between 1.005 g/cm3 and 1.025 g/cm3. 2. The synthetic urine solution of claim 1, also including urea dissolved within said solution. 3. The synthetic urine solution of claim 1, wherein said biocide is selected from the group consisting of an oxidizing biocide, an organic biocide and an in situ agent. 4. The synthetic urine solution of claim 1, wherein said at least one ionic compound is selected from the group consisting of carbonate salts, halide salts, hydroxide salts and bromides. 5. The synthetic urine solution of claim 4, wherein said biocide is selected from the group consisting of an oxidizing biocide, an organic biocide and an in situ agent. 6. The synthetic urine solution of claim 4, further including urea dissolved within said solution. 7. A method of manufacturing a synthetic urine solution comprising: providing water; dissolving creatinine and biocide into said water to form a solution exhibiting a specific gravity level, said creatinine and biocide being selected in relative concentrations to minimize sepsis; adjusting said specific gravity level of said solution to between 1.005 g/cm3 and 1.025 g/cm3, and if necessary, adjusting the pH level of the solution to between 3 and 10. 8. The method of claim 7 further comprising sealing said synthetic urine solution within a container so as to further minimize sepsis of said synthetic urine solution. 9. The method of claim 8 wherein said biocide is selected from the group consisting of an oxidizing biocide, an organic biocide and an in situ agent. 10. The method of claim 9 further comprising adding urea to said synthetic urine solution. 11. The method of claim 7 wherein said biocide is selected from the group consisting of an oxidizing biocide, an organic biocide and an in situ agent. 12. The method of claim 7 further comprising adding urea to said synthetic urine solution. 13. A method of manufacturing a synthetic urine solution comprising: providing water having a pH between 3 and 10; dissolving creatinine and at least one dissociating ionic compound in the water to form a solution exhibiting a specific gravity, said creatinine and at least one dissociating ionic compound selected in relative concentrations to adjust said specific gravity to between 1.005 g/cm3 and 1.025 g/cm3; and removing bacteria from said solution. 14. The method of claim 13 wherein the step of dissolving creatinine and at least one dissociating ionic compound also includes dissolving urea in the water, said urea selected in a concentration relative to that of said creatinine and at least one dissociating ionic compound so as to maintain the specific gravity of the solution between 1.005 g/cm3 and 1.025 g/cm3. 15. The method of claim 14 further comprising the step of adding a biocide to said synthetic urine solution. 16. The method of claim 15 wherein said biocide is selected from the group consisting of an oxidizing biocide, an organic biocide and an in situ agent. 17. The method of claim 13 further comprising the steps of adding a biocide to the synthetic urine solution. 18. The method of claim 17 wherein said biocide is selected from the group consisting of an oxidizing biocide, an organic biocide and an in situ agent. 19. The method of claim 13, further comprising the step of sealing said synthetic urine solution within a container. 20. The method of claim 14, further comprising the step of sealing said synthetic urine solution within a container. | BACKGROUND OF THE INVENTION This invention relates to a composition and method of manufacturing synthetic urine. The kidneys remove unwanted substances circulating in the blood by way of producing urine, which is excreted from the body. Consequently, diverse waste substances and other substances unwanted by the body find their way into urine for subsequent removal from the body. Urinalysis is the testing of the composition and amounts of waste substances in urine, and provides a tremendously powerful diagnostic tool for the medical profession. In particular, many of these substances are indicative of certain medical conditions or other substances which have been metabolized by a person's kidneys. Using current urinalysis techniques, unwanted substances in a urine sample can mask existing medical conditions, while still some others can masquerade as non-existent medical conditions. In each instance, these unwanted substance undermine the usefulness of urinalysis as a medical diagnostic tool. Some of the unwanted substances that find their way into a urine sample are drugs (both legal and illegal) and metabolites thereof, along with other chemical residues or contaminants that may be present or otherwise contacted during the handling procedures. These substances can disturb the sensitive tests, making the actual state of the body difficult or impossible to determine. For example, insulin levels, para-aminohippuric acid, phenol sulfonphthalein, phosphate, arylsulfatase-A, lysosome, urine amylase, total urine estrogens, specific estrogens, progestins, aldosterone, catecholamines, 5-hydroxyindoleacetic acid, cortisol, homovanillic acid, human chorionic gonadotrophin, creatine, urea, uric acid, bilirubin, hemoglobin, hydroxyproline, melanin, porphorins, total protein, acid mucopolysaccharide, copper, glucose oxidase and urine ketone can all influence the results of most standard urinalysis testing methods in unintended or unpredictable ways. Essentially, these testing methods include a variety of immunoassays or assays by other techniques, such as isolation followed by gas or liquid chromatography followed by mass spectrometry. These tests make urinalysis a powerful diagnostic tool for identifying a whole range of conditions. For example, substance abuse and other indicia of disease or bodily state can easily be detected by urinalysis. However, in order to accurately establish standards of comparison for such tests, reliable urine samples are needed which are entirely free from any of the aforementioned substances. Thus, the development of a suitable, synthetic urine substitute would improve testing methods by providing researchers, potential urine donors and testing technicians with an accurate baseline reading for “clean” urine samples to compare against other suspect samples. To illustrate, a method for detecting this compound is described in U.S. Pat. No. 5,036,013, issued to El Sohly et al., where various deuterated cannabinoids are synthesized to help determine the quantitative amount of tetrahydrocannabinol in a urine sample. One method in particular involves spiking a clean urine sample with known amount of deuterated tetrahydrocannabinol and analyzing the resultant sample with gas chromatography/mass spectrometry in order to establish set standards of comparison. However, a failure to possess a truly clean sample could substantially influence and negatively affect the results of these methods. Another example of the problems created by interfering chemicals in urine is exemplified by the case of ibuprophan. Ibuprophan is a prostaglandin synthetase inhibitor that may be taken in large doses to relive pain and inflammation characteristic of arthritis. When a patient taking these massive doses is subjected to urinalysis, it may mask other drugs being taken by the donor, or may even be mistaken for tetrahydrocannabinol (a metabolite which many testing technicians classify as being indicative of marijuana use). Any misidentification of controlled substance use/abuse, personal information (pregnancy, use of cigarettes, etc.) or any of the numerous medical conditions that can be determined using urinalysis can have devastating personal consequences for the urine donor. Thus, some companies sell inexpensive home testing kits in order to provide some level or reassurance to potential urine donors whether they may have such a misidentification. However, given the potential liability for a misidentified or positive test, many lay persons feel intimidated by testing procedures, and these persons would welcome the ability to utilize a known sample, free from unwanted or unknown substances, for the sake of comparison. In response to the need for a reliable source of relatively inexpensive, “clean” urine samples which are free from any unwanted or unknown substances, numerous attempts to formulate synthetic urine have been made. For example, U.S. Pat. No. 6,306,422 to Batich et al. (table 3, col. 16, line 50 et seq.), U.S. Pat. No. 5,328,954 to Sarangapani (table 1, col. 9, line 29 et seq.), U.S. Pat. No. 5,489,281 to Watanabe et al. (col. 12, example 6) and U.S. Pat. No. 4,146,644 to Griffith et al. (table 1, col. 10). However, none of these references appears to address a simple composition which can be manufactured in an inexpensive manner. Additionally, all of these references require the use of creatinine or other compounds which can be consumed by bacteria present in the sample. Accordingly, all of these samples will undergo sepsis unless they are immediately used, thereby making these compounds as unattractive candidates for mass production and/or consumer sales. SUMMARY OF THE INVENTION It is an object of this invention to provide a reliable source of synthetic urine, along with a method for its manufacture, which is free from any and all unwanted or unknown substances. It is a further object of this invention to provide a synthetic urine, along with a method for its manufacture, which is capable of retaining its viability and utility for extended periods of time. Still further uses for such a synthetic urine can and will be devised by a prospective user based upon her or her own personal disposition, interests and privacy concerns. Accordingly, a composition of synthetic urine is claimed. This composition includes water, having a pH between 3 and 10 with creatinine and biocide dissolved therein. The composition further includes any compound which dissolves and dissociates in a water solution in a manner which insures that the specific gravity of the resulting solution mixture is between 1.005 g/cm3 and 1.025 g/cm3. Urea can be added as another possible element of the invention, and those skilled in the art will readily identify appropriate specific types of biocide oxiders, organics or in situ agents, along with a host of carbonates, halide salts, hydroxide salts and other chemicals which could serve as ideal ionic compounds within the meaning of the invention. A method for manufacturing synthetic urine is also disclosed. The method involves providing water, dissolving creatinine and biocide in the water, adjusting the resulting solution's specific gravity to be between 1.005 and 1.025 and, if necessary, the pH level of the solution. In another aspect, the method contemplates providing water with a pH between 3 and 10, mixing creatinine and at least one dissociating ionic compound to adjust the specific gravity of the resulting solution to be between 1.005 g/cm3 and 1.025 g/cm3 and removing bacteria from the solution so as to avoid sepsis of the creatinine. In each of these embodiments the same types of biocides and ionic compounds can be used as were identified in the composition embodiment above. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS While human urine may at varying times reflect a wide range of chemical compounds, almost all current urinalysis rely upon observation of three basic traits: pH level, specific gravity and the presence of creatinine. Consequently, it was discovered that an effective, yet cost efficient, synthetic urine solution having a final specific gravity between 1.005 g/cm3 and 1.025 g/cm3 needed only to contain three basic components: water with a pH between 3 and 10; creatinine; and some means for controlling or eliminating the unwanted sepsis of the creatinine. With respect to this final element, this bacteria control/elimination is most readily accomplished through the use of a biocide. Examining each of these three traits separately, the need for a water-based solution should be apparent. However, it is significant to note that human urine displays a wide range in terms of pH variation—anywhere from 3 to 10. This variation can be attributed to any number of factors regarding regional water quality, metabolic idiosyncrasies displayed by each individual and the like. Thus, the water supplied for the composition and method may need to have its pH adjusted accordingly. Significantly, while use of distilled, deionized water will produce the most reliable synthetic urine solutions in terms of elimination of unwanted substances, the invention may be practiced with equal efficacy using distilled water, deionized water or even regular tap water (drawn from any fresh water source having an appropriately low specific gravity—discussed below). Unless specifically noted to the contrary, use of the term “water” throughout this specification and appended claims is intended to embrace the broadest array of appropriate water sources available. The final synthetic urine solution must also have a specific gravity between 1.005 g/cm3 and 1.025 g/cm3. Insofar as specific gravity is a measure of relative ionic content of a solution, it should be a apparent to those familiar with body chemistry or kidney functioning that certain ions and compounds will be commonly found in human urine, especially those commonly encountered in food and water sources (for example, sodium, potassium, chloride, etc.). In contrast, other elements will be inherently unwise choices at anything beyond a trace level (for example Lanthanoid and Actinoid series ions). The precise amount of the particular compound or compounds selected to adjust the specific gravity will depend directly on the concentration of compound (if in solution), the molecular weight of its constituents, water temperature, relative volume of water solvent being used and other similar factors. With respect to the water used to manufacture the synthetic urine of the present invention, it is anticipated that significant increases will need to be made to the specific gravity, as distilled, deionized water has a specific gravity of 1.000 g/cm3 and tap water, while likely to vary by region, has a specific gravity around 1.003 g/cm3. In terms of the best compounds to utilize in adjusting the specific gravity, the single most important trait is that the compound must dissociate when dissolved in water. Additionally, it is preferred to find an inexpensive, widely available compound so as to minimize production costs. To that end, it is believed that carbonate salts, halide salts, hydroxide salts and certain bromides will have particular applicability. By way of illustration rather than limitation, these salts might include sodium bicarbonate, sodium, potassium, magnesium or calcium chlorides; sodium, potassium, or calcium hydroxides; and other similarly inexpensive and widely available salts. Creatinine is a protein created in connection with muscular activity. As such, medical science recognizes creatinine as an important constituent in the human bloodstream and, to the extent that the kidneys cleanse and purify the bloodstream, in the waste stream expelled from the kidneys in the form of urine. Significantly, because creatinine is a protein, it is the subject of sepsis and decomposition. Thus, creatinine serves as an excellent indicator in urinalysis because it is indicative of human origin and, by virtue of its septic disposition, creatinine also provides a natural measure to determine whether or not a sample was, in fact, recently produced. In order to insure stable creatinine levels in synthetic urine, it is therefore essential to remove or control the presence of sepsis-causing bacteria. However, whatever method of control is applied must also not interfere with the processes underpinning most urinalysis techniques. Thus, the use of an appropriate biocide is absolutely critical to the proper practice of the present invention. To the extent that human urine is sterile when excreted (under normal body conditions), the use of biocide represents a distinct departure from previous approaches to the manufacture of synthetic urine which relied solely on mimicking the compounds in actual urine without any regard for the long term shelf life of the synthetic solution. Moreover, it further demonstrates the need to select a biocide which is biologically active, yet does not interfere overtly with the chemistry of the synthetic urine solution itself (either through its chemical signature or by virtue of an abnormally large amount being detectable in the solution). Biocide can be generically defined as substances used to control or eliminate microbial populations in a sample. Three general classes have been identified as having particular applicability when used in connection with the present invention: oxidizing biocides, organic biocides and a somewhat more generalized category referred to as in situ agents. Each will be discussed briefly below, although it should be understood that biocides are a term of art, known to those familiar with water chemistry processes. Oxidizing biocides are generally self explanatory. This class includes any biologically effective agent which relies upon an oxidation process, including but not limited to various peroxides, hypochlorites, bromides and super oxides. Organic biocides encompass an expansive list of proteins and cyclical compounds known to those skilled in the art. In situ agents can be chemical compounds or actual physical processes designed to kill bacteria in a manner which is either self-generating or effective enough to prevent future degradation of the urine. Generic examples of such in situ agents include ozone, chlorine dioxide (or other dioxides), and ultraviolet radiation or irradiation processes followed by hermetic sealing of the sample. Specific examples of various biocides contemplated above include: BHAP (such as 2-Bromo-4-hydroxyacetophenone, an organo-bromine group); Bronopol (such as 2-Bromo-2-nitropropane-1,3 diol, an organo-bromine group); Carbamates (such as a mix of sodium dimethyldithiocarbamate (DIBAM) and disodium ethylene bisdithiocarbamate (NIBAM), or single product, such as potassium n-hydroxymethyl-n-methyldithiocarbamate, an organo-sulfur group); Chlorothioether (such as 2,2 Dihydroxy-5,5-dichlorodiphenyl monosulfide, a chlorinated phenolic thioether); DBNPA (such as 2-2-Dibromo-3-nitrilopropionamide, an organo-bromine group); DTEA, DTEA II (such as 2-(Decylthio)ethanamine, an alkylthioamine group); Guanides (including Guanidine and Biguanides) (such as dodecylguanidine hydrochloride and acetate, also polyhexamethylene biguanide hydrochloride, and tetradecylguanidine, all aliphatic guanadines); Glutaraldehyde (such as Pentane-1,5-dial., an aldehyde group); Isothiazolines (such as Alkyl isothiazolin-3-ones, an organo-sulfur group); MBT (such as Methylene bis(thiocyanate), an organo-sulfur group); Polyquat (such as broad-spectrum, cationic polymers of low molecular weight); Quats (ADBACs) (such as Alkyldimethylbenzylammonium chloride (also known as alkylbenzyldimethyl ammonium chloride or benzalkonium chloride), a quaternary ammonium compound group); Sulfone (such as Bis(trichloromethyl)sulfone, an organo-sulfur group); TBTO (such as Bis(tributyltin)oxide, an organo-tin group); TBZ (Tertbuthylazine) (such as 2-(tert-butylamino)-4-chloro-6-(ethylamino)-s-triazine, a Triazine group); TCCBN (such as Tetrachloro-2,4,6-cyano-3-benzonitrile, TCCBN functions similarly to the chlorophenols); TCMTB (such as 2(thiocyanomethylthio)benzothiazole); Thione (such as Tetrahydro-3,5,dimethyl-2H-1,3,5-thiadiazine-2-thione, an organo-sulfur group); THPS (TKHPS) (such as Tetrakish(hydroxymethyl)phosphonium sulfate, an alkyl phosphonium group); and TTPC (such as Tributyltetradecylphosphonium chloride, an alkylphosphonium group). Additionally, with respect to more commonly understood items, such as peroxides, hypochlorites and the like, it should be understood that this specification encompasses all forms of such compounds (for example, hydrogen peroxide, sodium peroxide, sodium hypochlorite, potassium hypochlorite, etc.). Other examples of biocides may exist and are expressly encompassed within the purvey of this specification. Notably, as embraced by this specification, oxidizing biocides—and hypochlorite in particular—should not be confused with the agents that are employed to oxidize metabolites in urine samples. Such metabolite oxidizers are often referred to as “adulterants” within the urinalysis industry. Adulterants are substances deliberately added to actual urine samples to chemically alter the metabolites indicative of certain conditions so as to render these metabolites undetectable by standard urinalysis techniques. Even though some substances like hypochlorite may possess utility as both a biocide and as an adulterant, the intended use of that substance (as either a biocide or an metabolite oxidizer) will substantially influence the conditions, concentration and manner in which the substance is provided. In particular, use as a biocide requires smaller concentrations and little to no regard for when the biocide is added during the manufacturing process. To illustrate, an oxidizing biocide such as sodium hypochlorite can be added in amounts as small as 1 mL per 3.8 L of water. Similar concentrations of other oxidizing biocides will have equal efficacy, as recognized by those skilled in the art. In contrast, use of hypochlorite as an adulterant as taught, inter alia, in U.S. Patent Application Serial No. 2002/0106807 must occur at higher concentrations and in a specific manner so as to oxidize certain metabolites or compounds. Thus, hypochlorite (and other oxidizing biocides) found in the present solution prevents the unwanted growth of bacteria. Moreover, to the extent that adulterants are often added to actual urine samples, the composition of the resulting mixture is substantially more complex, in terms of the variety of chemical species present, than the simplified composition of the present invention. /Another aspect of the present urine solution relates to the addition of urea in some form to the synthetic urine sample. While urea is not presently accounted for in most urinalysis techniques, its presence within a synthetic urine could add an additional level of realism for some applications. Notably, to the extent that urea is provided, it will need to be considered in the calculations of the amount of ionic dissociating compounds required to adjust the specific gravity and/or pH to the desired levels. Other functionally inconsequential additives or steps may also be included without departing from the principles of this invention. While these additives and steps expressly cover all foreseeable equivalents of the elements recited above, additional variations are possible. For example, it is possible to include a coloring agent and or olfactory substances to enhance the aesthetics or apparent authenticity of the synthetic urine produced according to this invention. The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom as some modifications will be obvious to those skilled in the art without departing from the scope and spirit of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates to a composition and method of manufacturing synthetic urine. The kidneys remove unwanted substances circulating in the blood by way of producing urine, which is excreted from the body. Consequently, diverse waste substances and other substances unwanted by the body find their way into urine for subsequent removal from the body. Urinalysis is the testing of the composition and amounts of waste substances in urine, and provides a tremendously powerful diagnostic tool for the medical profession. In particular, many of these substances are indicative of certain medical conditions or other substances which have been metabolized by a person's kidneys. Using current urinalysis techniques, unwanted substances in a urine sample can mask existing medical conditions, while still some others can masquerade as non-existent medical conditions. In each instance, these unwanted substance undermine the usefulness of urinalysis as a medical diagnostic tool. Some of the unwanted substances that find their way into a urine sample are drugs (both legal and illegal) and metabolites thereof, along with other chemical residues or contaminants that may be present or otherwise contacted during the handling procedures. These substances can disturb the sensitive tests, making the actual state of the body difficult or impossible to determine. For example, insulin levels, para-aminohippuric acid, phenol sulfonphthalein, phosphate, arylsulfatase-A, lysosome, urine amylase, total urine estrogens, specific estrogens, progestins, aldosterone, catecholamines, 5-hydroxyindoleacetic acid, cortisol, homovanillic acid, human chorionic gonadotrophin, creatine, urea, uric acid, bilirubin, hemoglobin, hydroxyproline, melanin, porphorins, total protein, acid mucopolysaccharide, copper, glucose oxidase and urine ketone can all influence the results of most standard urinalysis testing methods in unintended or unpredictable ways. Essentially, these testing methods include a variety of immunoassays or assays by other techniques, such as isolation followed by gas or liquid chromatography followed by mass spectrometry. These tests make urinalysis a powerful diagnostic tool for identifying a whole range of conditions. For example, substance abuse and other indicia of disease or bodily state can easily be detected by urinalysis. However, in order to accurately establish standards of comparison for such tests, reliable urine samples are needed which are entirely free from any of the aforementioned substances. Thus, the development of a suitable, synthetic urine substitute would improve testing methods by providing researchers, potential urine donors and testing technicians with an accurate baseline reading for “clean” urine samples to compare against other suspect samples. To illustrate, a method for detecting this compound is described in U.S. Pat. No. 5,036,013, issued to El Sohly et al., where various deuterated cannabinoids are synthesized to help determine the quantitative amount of tetrahydrocannabinol in a urine sample. One method in particular involves spiking a clean urine sample with known amount of deuterated tetrahydrocannabinol and analyzing the resultant sample with gas chromatography/mass spectrometry in order to establish set standards of comparison. However, a failure to possess a truly clean sample could substantially influence and negatively affect the results of these methods. Another example of the problems created by interfering chemicals in urine is exemplified by the case of ibuprophan. Ibuprophan is a prostaglandin synthetase inhibitor that may be taken in large doses to relive pain and inflammation characteristic of arthritis. When a patient taking these massive doses is subjected to urinalysis, it may mask other drugs being taken by the donor, or may even be mistaken for tetrahydrocannabinol (a metabolite which many testing technicians classify as being indicative of marijuana use). Any misidentification of controlled substance use/abuse, personal information (pregnancy, use of cigarettes, etc.) or any of the numerous medical conditions that can be determined using urinalysis can have devastating personal consequences for the urine donor. Thus, some companies sell inexpensive home testing kits in order to provide some level or reassurance to potential urine donors whether they may have such a misidentification. However, given the potential liability for a misidentified or positive test, many lay persons feel intimidated by testing procedures, and these persons would welcome the ability to utilize a known sample, free from unwanted or unknown substances, for the sake of comparison. In response to the need for a reliable source of relatively inexpensive, “clean” urine samples which are free from any unwanted or unknown substances, numerous attempts to formulate synthetic urine have been made. For example, U.S. Pat. No. 6,306,422 to Batich et al. (table 3, col. 16, line 50 et seq.), U.S. Pat. No. 5,328,954 to Sarangapani (table 1, col. 9, line 29 et seq.), U.S. Pat. No. 5,489,281 to Watanabe et al. (col. 12, example 6) and U.S. Pat. No. 4,146,644 to Griffith et al. (table 1, col. 10). However, none of these references appears to address a simple composition which can be manufactured in an inexpensive manner. Additionally, all of these references require the use of creatinine or other compounds which can be consumed by bacteria present in the sample. Accordingly, all of these samples will undergo sepsis unless they are immediately used, thereby making these compounds as unattractive candidates for mass production and/or consumer sales. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of this invention to provide a reliable source of synthetic urine, along with a method for its manufacture, which is free from any and all unwanted or unknown substances. It is a further object of this invention to provide a synthetic urine, along with a method for its manufacture, which is capable of retaining its viability and utility for extended periods of time. Still further uses for such a synthetic urine can and will be devised by a prospective user based upon her or her own personal disposition, interests and privacy concerns. Accordingly, a composition of synthetic urine is claimed. This composition includes water, having a pH between 3 and 10 with creatinine and biocide dissolved therein. The composition further includes any compound which dissolves and dissociates in a water solution in a manner which insures that the specific gravity of the resulting solution mixture is between 1.005 g/cm 3 and 1.025 g/cm 3 . Urea can be added as another possible element of the invention, and those skilled in the art will readily identify appropriate specific types of biocide oxiders, organics or in situ agents, along with a host of carbonates, halide salts, hydroxide salts and other chemicals which could serve as ideal ionic compounds within the meaning of the invention. A method for manufacturing synthetic urine is also disclosed. The method involves providing water, dissolving creatinine and biocide in the water, adjusting the resulting solution's specific gravity to be between 1.005 and 1.025 and, if necessary, the pH level of the solution. In another aspect, the method contemplates providing water with a pH between 3 and 10, mixing creatinine and at least one dissociating ionic compound to adjust the specific gravity of the resulting solution to be between 1.005 g/cm 3 and 1.025 g/cm 3 and removing bacteria from the solution so as to avoid sepsis of the creatinine. In each of these embodiments the same types of biocides and ionic compounds can be used as were identified in the composition embodiment above. detailed-description description="Detailed Description" end="lead"? | 20040128 | 20070320 | 20050728 | 73031.0 | 6 | WALLENHORST, MAUREEN | SYNTHETIC URINE AND METHOD OF MANUFACTURING SAME | SMALL | 0 | ACCEPTED | 2,004 |
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10,766,217 | ACCEPTED | Efficient verification for coarse/fine programming of non-volatile memory | A non-volatile memory device is programmed by first performing a coarse programming process and subsequently performing a fine programming process. The coarse/fine programming methodology is enhanced by using an efficient verification scheme that allows some non-volatile memory cells to be verified for the coarse programming process while other non-volatile memory cells are verified for the fine programming process. The fine programming process can be accomplished using current sinking, charge packet metering or other suitable means. | 1. An apparatus for programming non-volatile storage elements, comprising: a programming circuit in communication with said non-volatile storage elements; and one or more verification selection circuits in communication with said non-volatile storage elements, said one or more verification selection circuits cause a first subset of said non-volatile storage elements to be subjected to coarse verification concurrently while a second subset of said non-volatile storage elements are subjected to fine verification. 2. An apparatus according to claim 1, further comprising: a set of bit lines, each of said non-volatile storage elements are associated with at least one of said bit lines, said one or more verification selection circuits include one verification selection circuit for each of said bit lines. 3. An apparatus according to claim 1, wherein: said one or more verification selection circuits include one verification selection circuit for each non-volatile storage element of a subset of non-volatile storage elements. 4. An apparatus according to claim 1, wherein at least one of said one or more verification selection circuits comprises: a sense circuit in communication with a first non-volatile storage element; a programming mode indication circuit, in communication with said sense circuit, providing an output indicating whether said first non-volatile storage element is in a coarse programming mode or a fine programming mode based on said sense circuit; and a selection circuit in communication with said programming mode indication circuit, said selection circuit applies a coarse verification signal to said first non-volatile storage element if said first non-volatile storage element is in said coarse programming mode and applies a fine verification signal to said first non-volatile storage element if said first non-volatile storage element is in said fine programming mode. 5. An apparatus according to claim 1, wherein at least one of said one or more verification selection circuits comprises: a storage unit, said storage unit storing data indicating whether a first non-volatile storage element is in a coarse programming mode or a fine programming mode; a first switch in communication with a first non-volatile storage element; sense circuit connected to said first switch and providing an output to said storage unit, said storage unit uses said output from said sense circuit to indicate whether said first non-volatile storage element is in said coarse programming mode or said fine programming mode; and a second switch in communication with said storage unit and having an output connected to said sense circuit, said second switch receiving a coarse reference signal and a fine reference signal and providing either said coarse reference signal or said fine reference signal at said output of said second switch in response to said storage unit. 6. An apparatus according to claim 5, wherein: said non-volatile storage elements are flash memory devices. 7. An apparatus according to claim 5, wherein: said coarse reference signal and said fine reference signal provide reference currents. 8. An apparatus according to claim 5, wherein: said coarse reference signal and said fine reference signal provide reference voltages. 9. An apparatus according to claim 5, wherein: said coarse reference signal and said fine reference signal provide an indication of discharge times. 10. An apparatus according to claim 1, wherein: said coarse verification and said fine verification are performed using a discharge method. 11. An apparatus according to claim 1, wherein: said programming circuit includes a controller and a state machine; and said programming circuit is separate from said one or more verification selection circuits. 12. An apparatus according to claim 1, wherein: said non-volatile storage elements are multi-state flash memory devices. 13. An apparatus used during programming of a non-volatile storage element, comprising: a sense circuit in communication with said non-volatile storage element; a programming mode indication circuit providing an output indicating whether said non-volatile storage element is in a coarse programming mode or a fine programming mode based on said sense circuit; and a first selection circuit in communication with said programming mode indication circuit, said first selection circuit applies a coarse reference signal to said non-volatile storage element if said non-volatile storage element is in said coarse programming mode and applies a fine reference signal to said non-volatile storage element if said non-volatile storage element is in said fine programming mode. 14. An apparatus according to claim 13, wherein: said coarse reference signal and said fine reference signal are from voltage sources. 15. An apparatus according to claim 13, wherein: said coarse reference signal and said fine reference signal are from current sources. 16. An apparatus according to claim 13, wherein: said coarse reference signal and said fine reference signal indicate timing information. 17. An apparatus according to claim 16, wherein: said sense circuit includes electronic circuitry to perform a bit line discharge analysis to determine if said non-volatile storage element is verified. 18. An apparatus according to claim 13, wherein: said non-volatile storage element is a multi-state flash memory device. 19. An apparatus according to claim 13, wherein: said non-volatile storage element is a flash memory device. 20. An apparatus for programming non-volatile storage elements, comprising: means for providing a programming signal to said non-volatile storage elements as part of a programming process that includes a coarse programming phase and a fine programming phase such that one or more of said non-volatile storage elements are in said coarse programming phase while one or more of said non-volatile storage elements are in said fine programming phase; means for performing coarse verification for said one or more non-volatile storage elements that are in said coarse programming phase without performing fine verification for said one or more non-volatile storage elements that are in said coarse programming phase; and means for performing fine verification for said one or more non-volatile storage elements that are in said fine programming phase without performing coarse verification for said one or more non-volatile storage elements that are in said fine programming phase. 21. An apparatus according to claim 20, wherein: said means for performing coarse verification performs said coarse verification for said one or more non-volatile storage elements that are in said coarse programming phase while concurrently said means for performing fine verification performs said fine verification for said one or more non-volatile storage elements that are in said fine programming phase. 22. An apparatus according to claim 20, wherein: said means for performing coarse verification and said means for performing fine verification utilize a bit line discharge verification process. 23. An apparatus according to claim 20, wherein: said non-volatile storage elements are multi-state flash memory devices. 24. A method for programming non-volatile storage elements, comprising: providing a programming signal to said non-volatile storage elements, said step of providing is part of a programming process that includes a coarse programming phase and a fine programming phase such that one or more of said non-volatile storage elements are in said coarse programming phase while one or more of said non-volatile storage elements are in said fine programming phase; and performing coarse verification for said one or more of said non-volatile storage elements that are in said coarse programming phase while concurrently performing fine verification for said one or more of said non-volatile storage elements that are in said fine programming phase. 25. A method according to claim 24, wherein: said step of providing includes providing said programming signal to a word line common to at least a subset of said one or more of said non-volatile storage elements that are in said coarse programming phase and said one or more of said non-volatile storage elements that are in said fine programming phase. 26. A method according to claim 24, wherein: said non-volatile storage elements are flash memory devices. 27. A method according to claim 24, wherein: said non-volatile storage elements are multi-state flash memory devices. 28. A method according to claim 24, further comprising: using said coarse verification to determine when a particular non-volatile storage element completes said coarse programming phase and causing said particular non-volatile storage element to begin said fine programming phase. 29. A method according to claim 28, wherein: following said non-volatile storage element beginning said fine programming phase, said non-volatile storage element begins said fine verification. 30. A method according to claim 28, wherein: causing said particular non-volatile storage element to begin said fine programming phase includes raising a bit line voltage. 31. A method according to claim 28, wherein said step of performing comprises: performing coarse verification for said particular non-volatile storage element without performing fine verification for said particular non-volatile storage element, if said particular non-volatile storage element is determined to be in said coarse programming phase; and performing fine verification for said particular non-volatile storage element without performing coarse verification for said particular non-volatile storage element, if said particular non-volatile storage element is determined to be in said fine programming phase. 32. A method according to claim 24, wherein: said coarse verification and said fine verification are based on a bit line discharge process. 33. A method according to claim 24, wherein said step of performing comprises: pre-charging a first bit line based on a coarse pre-charge signal if a first non-volatile storage element is in said coarse programming phase; pre-charging said first bit line based on a fine pre-charge signal if said first non-volatile storage element is in said fine programming phase; applying a verify signal to a control gate for said first non-volatile storage element; and allowing said bit line to discharge for a fixed period of time. 34. A method according to claim 24, wherein said step of performing comprises: pre-charging a first bit line for a first non-volatile storage element; applying a verify signal to a control gate for said first non-volatile storage element; determining a time for said bit line to discharge until said bit line reaches a predetermined value; comparing a coarse compare value to said time, if said first non-volatile storage element is in said coarse programming phase; and comparing a fine compare value to said time, if said first non-volatile storage element is in said fine programming phase. 35. A method according to claim 34, wherein: said predetermined value is a first value if said first non-volatile storage element is in said coarse programming phase; and said predetermined value is a second value if said first non-volatile storage element is in said fine programming phase. 36. A method performed when programming a non-volatile storage element, comprising: determining whether said non-volatile storage element is in a coarse programming mode or a fine programming mode; performing coarse verification for said non-volatile storage element without performing fine verification for said non-volatile storage element, if said non-volatile storage element is determined to be in said coarse programming mode; and performing fine verification for said non-volatile storage element without performing coarse verification for said non-volatile storage element, if said non-volatile storage element is determined to be in said fine programming mode. 37. A method according to claim 36, wherein: said coarse verification and said fine verification are based on a bit line discharge process. 38. A method according to claim 36, wherein: said non-volatile storage element is a flash memory device. 39. A method according to claim 36, wherein: said non-volatile storage element is a multi-state flash memory device. | CROSS-REFERENCE TO RELATED APPLICATIONS This Application is related to the following two United States Patent Applications: “Charge Packet Metering For Coarse/Fine Programming Of Non-Volatile Memory,” Daniel C. Guterman, Nima Mokhlesi and Yupin Fong, filed the same day as the present application; and “Variable Current Sinking For Coarse/Fine Programming Of Non-Volatile Memory,” Daniel C. Guterman, Nima Mokhlesi and Yupin Fong, filed the same day as the present application. The two above-listed related applications are both incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to technology for non-volatile memory. 2. Description of the Related Art Semiconductor memory devices have become more popular for use in various electronic devices. For example, non-volatile semiconductor memory is used in cellular telephones, digital cameras, personal digital assistants, mobile computing devices, non-mobile computing devices and other devices. Electrical Erasable Programmable Read Only Memory (EEPROM) and flash memory are among the most popular non-volatile semiconductor memories. Both EEPROM and flash memory utilize a floating gate that is positioned above and insulated from a channel region in a semiconductor substrate. The floating gate is positioned between source and drain regions. A control gate is provided over and insulated from the floating gate. The threshold voltage of the transistor is controlled by the amount of charge that is retained on the floating gate. That is, the minimum amount of voltage that must be applied to the control gate before the transistor is turned on to permit conduction between its source and drain is controlled by the level of charge on the floating gate. Some EEPROM and flash memory devices have a floating gate that is used to store two ranges of charges and, therefore, the memory cell can be programmed/erased between two states. When programming an EEPROM or flash memory device, typically a program voltage is applied to the control gate and the bit line is grounded. Electrons from the channel are injected into the floating gate. When electrons accumulate in the floating gate, the floating gate becomes negatively charged and the threshold voltage of the memory cell is raised. Typically, the program voltage applied to the control gate is applied as a series of pulses. The magnitude of the pulses is increased with each successive pulse by a predetermined step size (e.g. 0.2 v). In the periods between the pulses, verify operations are carried out. That is, the programming level of each cell of a group of cells being programmed in parallel is read between successive programming pulses to determine whether it is equal to or greater than a verify level to which it is being programmed. One means of verifying the programming is to test conduction at a specific compare point. The cells that are verified to be sufficiently programmed are locked out, for example in NAND cells, by raising the bit line voltage from 0 to Vdd (e.g., 2.5 volts) to stop the programming process for those cells. In some cases, the number of pulses will be limited (e.g. 20 pulses) and if a given memory cell is not completely programmed by the last pulse, then an error is assumed. In some implementations, memory cells are erased (in blocks or other units) prior to programming. More information about programming can be found in U.S. patent application Ser. No. 10/379,608, titled “Self Boosting Technique,” filed on Mar. 5, 2003; and in U.S. patent application Ser. No. 10/629,068, titled “Detecting Over Programmed Memory,” filed on Jul. 29, 2003, both applications are incorporated herein by reference in their entirety. FIG. 1 shows a program voltage signal Vpgm applied to the control gates (or, in some cases, steering gates) of flash memory cells. The program voltage signal Vpgm includes a series of pulses that increase in magnitude over time. At the start of the program pulses, the bit lines (e.g. connected to the drain) of all cells that are to be programmed are grounded, thereby, creating a voltage difference of Vpgm-0v from gate to channel. Once a cell reaches the targeted voltage (passing program verify), the respective bit line voltage is raised to Vdd so that the memory cell is in the program inhibit mode (e.g. program to that cell stops). A multi-state flash memory cell is implemented by identifying multiple, distinct allowed threshold voltage ranges separated by forbidden voltage ranges. For example, FIG. 2 shows eight threshold ranges (0, 1, 2, 3, 4, 5, 6, 7), corresponding to three bits of data. Other memory cells can use more than eight threshold ranges or less than eight threshold ranges. Each distinct threshold voltage range corresponds to predetermined values for the set of data bits. In some implementations, these data values (e.g. logical states) are assigned to the threshold ranges using a gray code assignment so that if the threshold voltage of a floating gate erroneously shifts to its neighboring physical state, only one bit will be affected. The specific relationship between the data programmed into the memory cell and the threshold voltage ranges of the cell depends upon the data encoding scheme adopted for the cells. For example, U.S. Pat. No. 6,222,762 and U.S. patent application Ser. No. 10/461,244, “Tracking Cells For A Memory System,” filed on Jun. 13, 2003, both of which are incorporated herein by reference in their entirety, describe various data encoding schemes for multi-state flash memory cells. As described above, when programming flash memory cells, between the programming pulses the memory cells are verified to see if they reached the target threshold value. One means for verifying is to apply a pulse at the word line corresponding to the target threshold value and determine whether the memory cell turns on. If so, the memory cell has reached its target threshold voltage value. For arrays of flash memory cells, many cells are verified in parallel. For arrays of multi-state flash memory cells, the memory cells will perform a verification step of each state to determine which state the memory cell is within. For example, a multi-state memory cell capable of storing data in eight states may need to perform verify operations for seven compare points. FIG. 3 shows three programming pulses 10a, 10b and 10c (each of which are also depicted in FIG. 1). Between the programming pulses are seven verify pulses in order to perform seven verify operations. Based on the seven verify operations, the system can determine the state of the memory cells. Performing seven verify operations after each programming pulses slows down the programming process. One means for reducing the time burden of verifying is to use a more efficient verify process. For example, in U.S. patent application Ser. No. 10/314,055, “Smart Verify for Multi-State Memories,” filed Dec. 5, 2002, incorporated herein by reference in its entirety, a Smart Verify process is disclosed. In an exemplary embodiment of the write sequence for the multi-state memory during a program/verify sequence using the Smart Verify process, at the beginning of the process only the lowest state (e.g. state 1 of FIG. 2) of the multi-state range to which the selected memory cells are being programmed is checked during the verify phase. Once the first storage state (e.g. state 1 of FIG. 2) is reached by one or more of the memory cells, the next state (e.g. state 2 of FIG. 2) in the sequence of multi-states is added to the verify process. This next state can either be added immediately upon the fastest cells reaching this preceding state in the sequence or, since memories are generally designed to have several programming steps to move from state to state, after a delay of several cycles. The amount of delay can either be fixed or use a parameter based implementation, which allows the amount of delay to be set according to device characteristics. The adding of states to the set being checked in the verify phase continues as per above until the highest state has been added. Similarly, lower states can be removed from the verify set as all of the memory cells bound for these levels verify successfully to those target values and are locked out from further programming. In addition to programming with reasonable speed, to achieve proper data storage for a multi-state cell, the multiple ranges of threshold voltage levels of the multi-state memory cell should be separated from each other by sufficient margin so that the level of the memory cell can be programmed and read in an unambiguous manner. Additionally, a tight threshold voltage distribution is recommended. To achieve a tight threshold voltage distribution, small program steps typically have been used, thereby, programming the threshold voltage of the cells more slowly. The tighter the desired threshold distribution, the smaller the steps and the slower the programming process. One solution for achieving tight threshold distributions without unreasonably slowing down the programming process is to use a two phase programming process. The first phase, a coarse programming phase, includes attempts to raise the threshold voltage in a faster manner and paying relatively less attention to achieving a tight threshold distribution. The second phase, a fine programming phase, attempts to raise the threshold voltage in a slower manner in order to reach the target threshold voltage while also achieving a tighter threshold distribution. Example of coarse/fine programming methodologies can be found in the following patent documents that are incorporated herein by reference in their entirety: U.S. patent application Ser. No. 10/051,372, “Non-Volatile Semiconductor Memory Device Adapted to Store A Multi-Valued Data in a Single Memory Cell,” filed Jan. 22, 2002; U.S. Pat. No. 6,301,161; U.S. Pat. No. 5,712,815; U.S. Pat. No. 5,220,531; and U.S. Pat. No. 5,761,222. When verifying a memory cell during programming, some prior solutions will first perform the verify process for the coarse mode and then subsequently perform the verify process for the fine mode. Such a verification process increases the time needed for verification. The coarse/fine programming methodology can be used in conjunction with the Smart Verify process described above. As memory devices become smaller and more dense, the need for tighter threshold distributions and reasonable program times has increased. Although the coarse/fine programming methodology provides a solution to some existing issues, there is further need to improve the coarse/fine programming methodology to provide the desired tighter threshold distributions and reasonable program times. SUMMARY OF THE INVENTION The present invention, roughly described, pertains to technology for non-volatile memory. More specifically, the technology described herein can be used to provide an improved coarse/fine programming methodology. One embodiment of the present invention includes an apparatus for programming non-volatile storage elements. The apparatus includes non-volatile storage elements in communication with a programming circuit and one or more verification selection circuits. The verification selection circuits cause a first subset of the non-volatile storage elements to be subjected to coarse verification concurrently while a second subset of non-volatile storage elements are subjected to fine verification. Some embodiments of the present invention include a sense circuit in communication with a non-volatile storage element, a programming mode indication circuit providing output indicating whether the non-volatile storage element is in a coarse programming mode or a fine programming mode based on the sense circuit, and a first selection circuit in communication with the programming mode indication circuit. The first selection circuit applies a coarse verification signal to the non-volatile storage element if the non-volatile storage element is in a coarse programming mode and applies a fine verification signal to the non-volatile storage element if the non-volatile storage element is in a fine programming mode. In one example of an implementation, the apparatus performs a method comprising the steps of determining whether the non-volatile storage element is in a coarse programming mode or a fine programming mode. Coarse verification is performed for the non-volatile storage element without performing fine verification on the non-volatile storage element if that non-volatile storage element is determined to be in the coarse programming mode. Fine verification is performed for that non-volatile storage element without performing coarse verification on the non-volatile storage element if that non-volatile storage element is determined to be in the fine programming mode. Another embodiment in the present invention includes a non-volatile storage element having a gate and a set of control terminals. The apparatus also includes a switchable current sinking device in communication with at least one of the control terminals. The switchable current sinking device provides a coarse current sink to the control terminal if the non-volatile storage element is in a coarse programming mode and provides a fine current sink to the control terminal if the non-volatile storage element is in a fine programming mode. In some embodiments, a current sink is provided during the fine programming mode but not during the coarse programming mode. Another embodiment of the present invention includes a sense circuit in communication with the non-volatile storage element, a programming mode indication circuit providing output indicating whether the non-volatile storage element is in a coarse programming mode or fine programming mode based on the sense circuit, and a switchable current sinking device in communication with the programming mode indication circuit and the non-volatile storage element. The switchable current sinking device provides a coarse current sink to the non-volatile storage element if the non-volatile storage element is in the coarse programming mode and provides a fine current sink to the non-volatile storage element if the non-volatile storage element is in fine programming mode. In one embodiment, an apparatus will apply a common programming signal to a gate for a non-volatile storage element, sink a first current from the non-volatile storage element during coarse programming, determine that a threshold voltage of the non-volatile storage element has reached a first verify level and switch the sinking to seek a second current in response to determining if the threshold voltage of the non-volatile storage element has reached the first verify level. Another embodiment of the present invention includes a sense circuit in communication with a non-volatile storage element, a programming mode indication circuit providing an output indicating whether the non-volatile storage element is in a coarse programming mode or a fine programming mode based on the sense circuit, and a switchable charge packet metering circuit in communication with the programming mode indication circuit and the non-volatile storage element. The switchable charge packet metering circuit provides a metered charge to the non-volatile storage element in response to the programming mode indication circuit indicating that the non-volatile storage element is in the fine programming mode. Yet another embodiment of the present invention includes a set of non-volatile storage elements and an individually switchable charge packet metering system in communication with the non-volatile storage elements. The individually switchable charge packet metering system is individually switched to provide a particular metered charge to program non-volatile storage elements in a fine programming mode without providing that particular metered charge to program non-volatile storage elements in a coarse programming mode. One embodiment includes performing a coarse programming process on the non-volatile storage elements, determining that the non-volatile storage elements should switch to a fine programming process, and performing the fine programming process in response. One implementation of the fine programming process includes the pre-charging of a control line for a non-volatile storage element and discharging that control line via the non-volatile storage element in order to program that non-volatile storage element. These and other objects and advantages of the present invention will appear more clearly from the following description in which the preferred embodiment of the invention has been set forth in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts an example of a program voltage used to program non-volatile memory cells. FIG. 2 depicts an example of a state space for a non-volatile memory device. FIG. 3 depicts an example of program voltage pulses used to program flash memory cells and verification pulses between the program pulses. FIG. 4 is a block diagram of one embodiment of a flash memory system that can implement the present invention. FIG. 5 is a plan view of one embodiment of a portion of the memory cell array of the system of FIG. 4. FIG. 6 is a partial cross-sectional view of the memory cell array of FIG. 5 taken at section A-A. FIG. 7 is an electrical equivalent circuit to the structure of FIG. 3. FIG. 8 is a table providing example voltages for one way to operate the memory cells. FIG. 9A includes graphs of threshold voltage and bit line voltage versus time for coarse/fine programming. FIG. 9B includes alternative graphs of threshold voltage and bit line voltage versus time for coarse/fine programming. FIG. 10 is a flow chart describing one embodiment of a process for programming non-volatile memory. FIG. 11 is a flow chart describing one embodiment of a process for performing coarse/fine verification. FIG. 12 is a block diagram of components used to verify a non-volatile memory cell. FIG. 13 is a graph of bit line voltage versus time for sensing. FIG. 14 is an alternative block diagram of components used to verify a non-volatile memory cell. FIG. 15 is an alternative block diagram of components used to verify a non-volatile memory cell. FIG. 16 is a graph of threshold voltage versus program pulse. FIG. 17 is a schematic of non-volatile memory using a first embodiment of current sinking. FIG. 18 is a schematic of non-volatile memory using a second embodiment of current sinking. FIG. 19 is a flow chart describing one embodiment of a coarse/fine programming process that uses current sinking. FIG. 20 is a schematic of non-volatile memory using a first embodiment of charge packet metering. FIG. 21 depicts graphs of voltage versus time. FIG. 22 is a flow chart describing one embodiment of a coarse/fine programming process that uses charge packet metering. FIG. 23 is a schematic of non-volatile memory using a second embodiment of charge packet metering. FIG. 24 is a schematic of non-volatile memory using a third embodiment of charge packet metering. FIG. 25 is a schematic of non-volatile memory using a fourth embodiment of charge packet metering. DETAILED DESCRIPTION I. Memory System An example memory system incorporating the various aspects of the present invention is generally illustrated in the block diagram of FIG. 4. Architectures other than that of FIG. 4 can also be used with the present invention. A large number of individually addressable memory cells 11 are arranged in an array of rows and columns. Bit lines, which extend along columns of array 11, are electrically connected with bit line decoder, driver and sense amplifiers circuit 13 through lines 15. Word lines, which extend along rows of array 11, are electrically connected through lines 17 to word line decoders and drivers circuit 19. Steering gates, which extend along columns of memory cells in array 11, are electrically connected to steering gate decoders and drivers circuit 21 through lines 23. Each of the circuits 13, 19 and 21 receives addresses from controller 27 via bus 25. The decoder and driving circuits 13, 19 and 21 are also connected to controller 27 over respective control and status signal lines 29, 31, and 33. Voltages applied to the steering gates and bit lines are coordinated through bus 22 that interconnects the controller and driver circuits 13 and 21. In some embodiments, controller 27 includes a state machine to coordinate performance of the functions described herein. In other embodiments, the state machine operates separately from the controller. Controller 27 is connectable through lines 35 to a host device (not shown). The host may be a personal computer, notebook computer, handheld device, digital camera, audio player, cellular telephone or various other devices. The memory system of FIG. 4 can be implemented in a card according to one of several existing physical and electrical standards, such as one from the PCMCIA, the CompactFlash™ Association, the MMC™ Association, Smart Media, Secure Digital™, Memory Stick, and others. When in a card format, the lines 35 terminate in a connector on the card which interfaces with a complementary connector of the host device. Alternatively, the memory system of FIG. 4 can be embedded in the host device. In yet another alternative, controller 27 can be embedded in the host device while the other components of the memory system are on a removable card. In other embodiments, the memory system can be in packaging other than a card. For example, the memory system can be in one or more integrated circuits, one or more circuit boards or other packages. Decoder and driver circuits 13, 19 and 21 generate appropriate voltages in their respective lines of array 11, as addressed over the bus 25, according to control signals in respective control and status lines 29, 31 and 33 to execute programming, reading and erasing functions. Status signals, including voltage levels and other array parameters, are provided by array 11 to controller 27 over the same control and status lines 29, 31 and 33. A plurality of sense amplifiers within the circuit 13 receive current or voltage levels that are indicative of the states of addressed memory cells within array 11. The sense amplifiers provide controller 27 with information about the states of the memory cells over lines 41 during a read operation. A large number of sense amplifiers are usually used in order to be able to read the states of a large number of memory cells in parallel. II. Memory Cell FIG. 5 is a plan view of a first embodiment of a portion of memory array 11. FIG. 6 is a partial cross-sectional view of the memory array taken at Section A-A. The substrate and conductive elements are illustrated with little detail of dielectric layers that exist therebetween in order to simplify the figures. However, it will be understood that appropriate oxide layers are to be included between the conductive layers themselves, and the conductive layers and the substrate. A silicon substrate 45 includes a planar top surface 47. Elongated diffusions 49, 51 and 53 are formed into the substrate 45 through the surface 47 by an initial ion implantation and subsequent diffusion. Elongated diffusions 49, 51 and 53 serve as sources and drains of the memory cells. In order to provide a convention for this description, the diffusions are shown to be spaced apart in a first “x” direction, with lengths extending in a second “y” direction. These “x” and “y” directions are essentially orthogonal with each other. A number of floating gates are included across the substrate surface 47, with suitable gate dielectric therebetween, in an array of rows and columns. One row of floating gates 55, 56, 57, 58, 59, 60 is adjacent to and parallel with another row of floating gates 62, 63, 64, 65, 66, 67. A column of floating gates 69, 55, 62, 71 and 73 is adjacent to and parallel with a column of floating gates 75, 56, 63, 77 and 79. The floating gates are formed from a first layer of conductively doped polycrystalline silicon (“polysilicon”) that is deposited over the surface and then separated by etching using one or more masking steps into the individual floating gates. Bit line decoder and driver circuit 13 (See FIG. 4) is connected through lines 15 with all of the bit line source/drain diffusions of the array, including the diffusions 49, 51 and 53 of FIG. 5. The sources and drains of columns of individual memory cells are connected to proper operating voltages for either reading or programming in response to addresses supplied over bus 25 and control signals over the lines 29. The structure of FIGS. 5 and 6 uses one steering gate for every two columns of floating gates. Steering gates 81, 83 and 85 are elongated in the “y” direction and have a width in the “x” direction that extends across two adjacent columns of floating gates and a source/drain diffusion that is positioned in between them. The space between any two of the steering gates is at least as great as the space in the “x” direction between adjacent columns of floating gates that are overlaid by the two steering gates, in order to allow a gate to be later formed at the substrate in this space. The steering gates are formed by etching a second layer of conductively doped polysilicon that is deposited over the entire surface over the first polysilicon layer and an appropriate inter-polysilicon layer dielectric. Steering gate decoder and driver circuit 21 (see FIG. 4) connects though lines 23 to all the steering gates and is able to individually control their voltages in response to addresses provided on the bus 25, control signals on the lines 33, and data from drivers and sense amplifiers 13. Word lines 91, 92, 93, 94 and 95 are elongated in the “x” direction and extend over the steering gates with spaces between them in the “y”-direction that places each word line in alignment with a row of floating gates. The word lines are formed by etching a third layer of conductively doped polysilicon that is deposited over the entire surface on top of a dielectric that is first formed over the second polysilicon layer and regions exposed between the steering gates. The word lines allow selection of all the memory cells in its row for reading or writing. Select gate decoder and driver circuit 19 (see FIG. 4) is connected with each word line in order to individually select one row of the memory array. Individual cells within a selected row are then enabled for reading or writing by the bit line and steering gate decoder and driver circuits 13 and 21 (see FIG. 4). Although the gates in the foregoing structure are preferably made of doped polysilicon material, other suitable electrically conductive materials may be used in place of one or more of the three polysilicon layers described. The third layer, for example, from which the word lines and select gates are formed, may be a polycide material, which is polysilicon with a conductive refractory metal silicide on its top, such as tungsten, in order to increase its conductivity. Polycides are generally not used in place of either the first or second polysilicon layers because the quality of inter-polycrystalline-silicon oxides formed from a polycide is usually not satisfactory. Not shown in FIGS. 5 and 6 are the metal conductor layers. Since the diffusions and polysilicon elements usually have a conductivity that is significantly less than that of metal, metal conductors are included in separate layers with connections made to respective metal lines through any intermediate layers at periodical intervals along the lengths of the polysilicon elements and diffusions. Since all of the diffusions and polysilicon elements of the embodiment of FIGS. 5-6 need to be separately driven, there is typically a one-to-one correspondence between the number of these metal lines and the number of diffusions and polysilicon elements. FIG. 7 depicts an electrically equivalent circuit to the structure of FIG. 6, where equivalent elements are identified by the same reference numbers as in FIGS. 5 and 6, but with a prime (′) added. The illustrated structure shares the source and drain diffusions with a neighboring structure. Conduction through the channel in the substrate between the adjacent diffusions 49 and 51 is controlled by different gate elements in three different regions. A first region to the left (T1-left) has the floating gate 56 immediately above it and the steering gate 81 capacitively coupled with it. A second region to the right (T1-right) is controlled in a similar manner by the floating gate 57 and the steering gate 83. A third region T2, between T1-left and T1-right, is controlled by select gate 99 that is part of word line 92. The level of conduction of electrons through the channel between diffusions 49 and 51 is thus affected by the electric fields imparted by these different gate elements to their respective channel regions through the voltages placed on the gates. The voltage on a floating gate is dependent upon the level of net electrical charge it carries plus all displacement charge that is capacitively coupled from other gates and nodes. The level of conduction that is permitted through the channel portion under a floating gate is controlled by the voltage on that floating gate. The voltage on select gate 99 simply turns the channel off and to a targeted conduction level in order to select individual cells for connection with their source/drain regions. In one embodiment, an individual memory cell can be considered as a series connection of three transistors, one for each of the three different regions (T1-left, T2, T1-Right) of the channel. In other embodiments, each floating gate can be considered a memory cell. One of the two floating gates of a single memory cell is selected for programming or reading by placing a voltage on the steering gate above the other (non-selected) floating gate of the cell that is sufficient to cause the channel region under the other floating gate to become adequately conductive no matter what charge (which is related to its state) is carried by that other floating gate. When that cell's select transistor is turned on by a sufficient voltage applied to its word line, it is only the selected floating gate that responds to reading or programming operations directed to the cell. During a reading of the state of the one floating gate, current through the cell between its source and drain is then dependent upon the charge carried by the selected floating gate without regard to the charge on the other floating gate. Although the voltage placed on the steering gate over the non-selected floating gate to render the channel portion under the non-selected floating gate conductive is also coupled to an adjacent floating gate of an adjacent cell through the same steering gate, impact on the adjacent cell is avoided by placing proper voltage conditions on the other elements of the adjacent cell. The floating gates of the embodiment of FIGS. 5-7 are preferably programmed by placing voltages on its bit lines (source and drain diffusions) and its two steering gates that cause electrons to obtain enough energy in the substrate channel region to be injected across the gate dielectric into the selected floating gate. A preferred technique for this is “source side injection,” described in the U.S. Pat. Nos. 5,313,421 and 5,712,180, both of which are incorporated herein by reference in their entirety. In order to erase the memory cells of the embodiment of FIGS. 5-7, they may be designed and operated so that electrons are removed from the selected floating gates to either the channel or the select gate of the word line. If erased to the select gate, the dielectric between floating gate edge 103 and select gate 99 is preferably a thin layer of oxide that has been grown on the floating gate edge and through which electrons tunnel when appropriate voltages are placed on the various elements of the cell. The same is provided between floating gate edge 105 and select gate 99. When designed to be erased to select gate 99, care is taken to make sure that a resulting voltage gradient across the gate dielectric between the select gate and substrate surface 47 remains sufficiently below a breakdown level of that dielectric. This is a concern because the word line is typically raised to a level in excess of 10 volts and sometimes to 20 volts or more during erase, while other voltages applied to the cell are usually 5 volts or less. The voltage gradient across the select gate dielectric can be reduced by making it thicker or the select gate dielectric can be selected to have a dielectric constant that is higher than normally used. The later can adversely affect operation of the select transistor. If the cells are to be erased to the channel, the embodiment of FIGS. 5-7 is modified somewhat. First, the dielectric between select gate 99 and the adjacent floating gate edges 103 and 105 is made to be thicker to prevent erasing of the floating gates to the select gate. Second, the thickness of the gate dielectric between an underside of the floating gates and the substrate surface 47 is made thinner, such as about 100 Angstroms, to facilitate electrons tunneling through it. Third, the cells to be simultaneously erased as a block are grouped together along columns or within blocks. In one embodiment, a block is isolated on the substrate from other blocks. This is typically done by a triple well process, where an n-well is formed in a p-substrate, and a p-well carrying the block of cells is positioned within the n-well that isolates the block from others. An appropriate erase voltage is then applied to the p-wells of the blocks to be erased, while other blocks are not affected. More details about the structures of FIGS. 4-7 can be found in U.S. Pat. No. 6,151,248, which is incorporated herein by reference in its entirety. The memory structure of FIGS. 4-7 is one example of a suitable memory cell. Other structures can also be used to implement the present invention. For example, one embodiment can use a multi-layer dielectric that includes a charge storing dielectric. Other embodiments of the present invention can use NAND type flash memory cells or NOR type flash memory cells. Relevant examples of NAND type flash memories and their operation are provided in the following U.S. Patents/Patent Applications, all of which are incorporated herein by reference in their entirety: U.S. Pat. No. 5,570,315; U.S. Pat. No. 5,774,397; U.S. Pat. No. 6,046,935; U.S. Pat. No. 5,386,422; U.S. Pat. No. 6,456,528 and U.S. patent application. Ser. No. 09/893,277 (Publication No. U.S. 2003/0002348). The following patents describe NOR type flash memories and are incorporated herein by reference in their entirety: U.S. Pat. Nos. 5,095,344; 5,172,338; 5,890,192 and 6,151,248. Other types of flash memory cells and other types of non-volatile storage elements can also be used. III. Memory Array Operation Example operating voltages to program, read and erase the memory cells of array 11 are provided in the table of FIG. 8. Line (2) pertains to the operation of the type of cells that are erased to the select gates (word lines), while line (8) shows a modification for operating the type of cells that are erased to the substrate. In these examples, the substrate portion in which the cells are formed contains p-type doping and the bit line diffusions are of n-type. The substrate is held at ground potential throughout these operations. In line (1) of the FIG. 8 table, the voltage conditions are given for a row that is not selected. The word line of an unselected row is placed at ground potential by driver circuit 19 (FIG. 4). The “X” in the columns for the bit lines (diffusions) and steering gates of cells along an unselected row indicates that the voltages on those elements do not matter—a “don't care” situation. Since there are no negative voltages generated by any of the circuits 13, 19 and 21 for elements of the array, in this example, a zero voltage on the select gates of a row assures that none of the cells along that row are enabled. No current can flow through their channels. Programming or reading of other cells in the same columns of a different row can take place without affecting the row having a zero voltage on its word line. The second line (2) of the table provides an example set of voltages for erasing the type of cells designed to be erased to the word line's select gate. A high erase voltage VE in a range of 10-25 volts (e.g. 20 volts) is applied by driver circuits 19 to all the word lines whose floating gates are to be erased. This is usually at least one defined block of cells including all cells in a large number of contiguous rows. However, in applications where it is preferred, fewer or more cells may be simultaneously erased. The erase block can, alternatively, even be limited to a single row of cells. The steering gates of the cells along the one or more selected rows are set to a low voltage by the driving circuit 21 (e.g., zero volts) in order to maintain, by the high degree of capacitive coupling between the steering and floating gates, the voltage of the floating gates at a low level. The resulting potential difference between the floating gates and their respective select gates (word lines) causes electron tunneling through the intermediate dielectric. More information about erasing is found in U.S. Pat. No. 5,270,979, incorporated herein by reference. Lines (3) and (4) in the table of FIG. 5 provide example voltages for reading the state of the two floating gates of a memory cell: line (3) for the left floating gate and line (4) for the right floating gate. In each case, the cell is enabled by the select gate being raised to a voltage VSR sufficient to turn on the cell's select transistor to enable current to flow through the channel. This voltage is typically one volt higher than the threshold of the select transistor. When reading the voltage state of one floating gate, the steering gate over the floating gate being read has a voltage VM applied to it and the steering gate over the other floating gate is raised to VBR, as shown in lines (3) and (4) of the table of FIG. 8. The voltage VBR is made to be high enough (e.g., 8 volts) to render the cell's channel portion under the non-selected floating gate sufficiently conductive, no matter what the programmed state of the non-selected floating gate. To read the state of the selected floating gate, the voltage VM is stepped through multiple voltages (described below) during the reading step, and its value when the cell current passes through a defined threshold is detected by the sense amplifiers within circuit 13. Example voltages for programming one floating gate of a dual floating gate cell are given in lines (5) and (6) of the table of FIG. 8. In order to select the cell for operation, the select gate is raised sufficiently to turn on the cell's select transistor. The voltage VSP may be different from the voltage VSR used during reading in order to optimize the source side injection programming speed. An example is VSP=2.2 volts when the threshold of the select transistor is one volt. The bit line diffusion on the same side of the cell as the floating gate selected to be programmed is raised to a maximum bit line voltage (e.g., 5 volts) during the programming operation. This voltage is made high enough to enable a sufficient field to be built up across the gap between the floating and select gate channels to obtain source side hot electron programming. The bit line diffusion on the same side of the cell as the non-selected floating gate is biased at or near zero volts during programming. The steering gate over the non-selected floating gate is raised to a voltage VBP that is sufficient to render the channel region under the non-selected floating gate sufficiently conductive (e.g. VBP=8 volts) in order to pose no interference to programming of the target floating gate, regardless of what floating gate voltage exists on the non-selected floating gate, within a programming window range of floating gate voltages. A voltage VP is applied to the steering gate over the selected floating gate with a level that drives the selected floating gate to a voltage that assists in creating the desired field conditions in the channel below it for hot electron programming. For example, the voltage VP can be within the range of 5-12 volts. This voltage may vary during the programming operation. Typically, the appropriate set of programming voltages is first applied to an erased cell, followed by the appropriate set of reading voltages, and, if the reading step does not indicate that the selected floating gate has been programmed to the desired voltage state, which may be the programming state for binary storage or one of the variable storage states for multi-level storage, programming voltages are again applied which may in part be different from the earlier set. Line (7) of the table of FIG. 8 shows voltages that are applied to those cells within a row selected for programming that are themselves not to be programmed. For example, the number of cells programmed at the same time within one row of a segmented portion of an array are spaced alternately along the row with other cells in between them that are not being programmed. It is these other cells not being programmed that receive the voltages of line (7) of the table of FIG. 8. The opposing bit line diffusions are maintained at the same voltage in order to prevent any current from flowing in the channel (e.g., both at zero or both at 5 volts). As with the notation used in line (1), the “x” indicates that the voltages on the steering gates of these cells are a don't care. In the case of memory arrays designed to be erased to the substrate, erase voltage conditions of line (8) are applied instead of those of line (2). Both the p-well containing a block of cells to be erased and its surrounding n-well are raised to the erase voltage VE, within an example range of 10-25 volts (e.g. 20 volts preferred). During reading and programming such cells, their wells are held at ground potential. A positive voltage VSE is preferably applied to the select gates during erase in order to reduce the voltage applied across the select gate dielectric, since an excessive voltage differential between the substrate and select gate can damage the dielectric material or cause it to be made thicker than otherwise desirable for operation of the cells. Since such a voltage is partially coupled from the select gates to the adjoining floating gates sought to be erased, it cannot be too high or else the voltage differential between the floating gates and the substrate channel, which is made high to effect the erase, is reduced too far. An example range of VSE is 3-12 volts, depending upon the level of VE. VSE=10 volts is preferred when VE=20 volts. The values provided in FIG. 8 are one set of examples. Those skilled in the art will be able to use other suitable values and methodologies for operating the memory system. IV. Coarse/Fine Programming FIG. 9A provides graphs of threshold voltage (VTH) versus time and bit line voltage (VBL) versus time to indicate how one example of a coarse/fine programming process is performed. Various alternatives and embodiments of the coarse/fine programming methodology can also be used. The method depicted in FIG. 9A starts with the programming-process performing the coarse phase of the programming process. When the threshold voltage of the memory cell reaches voltage of VLA, then the memory cell enters a fine programming phase by raising the bit line voltage of the cell to a value of V1 in order to slow down the programming. During the fine programming phrase, programming is slowed, as compared to the coarse programming phase. Therefore, the change in threshold voltage per program step is likely to be smaller during the fine programming phase. The memory cell will remain in the fine programming phase until the threshold voltage of the memory cell has reached the target threshold voltage level of Vv. When the threshold voltage of the memory cell reaches Vv, the memory cell's bit line voltage is raised to Vdd to inhibit further programming of that cell. In one embodiment, VLA is one Vpgm step size below Vv. In other embodiments, the difference between VLA and Vv is greater. The process depicted by FIG. 9A assumes one coarse programming mode and one fine mode. In other embodiments, multiple coarse modes and/or multiple fine modes can be used. For example, FIG. 9B shows three modes. In other embodiments more than three modes can be used. The embodiment to FIG. 9B shows a first mode (the most coarse mode) which is performed until the threshold voltage of the memory cell reaches VLA2. At that point the memory cell transitions to the intermediate programming mode (finer than the most coarse mode and coarser than the most fine mode), at which point the bit line is raised to the VI1. The memory cell will remain in intermediate mode until the threshold voltage of the memory cell reaches VLA1, at which time the memory cell will enter the finest program mode and the bit line will be raised to Vi2. The memory cell will remain in the finest program mode until the threshold voltage of the memory cell reaches Vv. When the memory cell threshold voltage reaches Vv, the bit line will be raised to Vdd in order to inhibit further programming of that memory cell. In other embodiments, as discussed above, more than three modes can be used (e.g. 4 modes, 5 modes, etc.). FIG. 10 is a flow chart describing one embodiment of the coarse/fine programming process. In step 202, the portion of the memory to be programmed is selected. In one implementation, this can be one or more write units appropriate to the memory structure. One example of a write unit is referred to as a page. In other embodiments, other units and/or structures can also be used. In step 204, a pre-programming process is sometimes used wherein the addressed memory cells are given non-data dependent programming to level out storage element wear and provide a more uniform starting point for the subsequent erase. In step 206, an erased process is performed, as appropriate for the type of storage element being used. One example of a suitable smart erase process is described in U.S. Pat. No. 5,095,344, incorporated herein by reference in its entirety. Step 208 includes a soft programming process designed to put the threshold voltages of erased memory cells into a more uniform starting range for the actual write phase. In one embodiment, if any of the memory cells fail to verify during erase (or during soft programming), they can be mapped out of the logical address space. At this point the memory is ready for the data conditional programming phase. In step 210, the program voltage (Vpgm) is set to an initial value. For example, in some embodiments, the staircase wave form of FIG. 1 is used and step 210 includes setting the initial pulse. Also, in step 210, a program counter (PC) is initialized to zero. In step 220, a program pulse is applied. For example, one iteration of step 220 could include applying program pulse 10A of FIG. 3. In step 222, a concurrent course and fine verification process is performed. One or more memory cells are verified for coarse programming in a manner that overlaps in time with one or more memory cells being verified for fine programming. For example in regard to binary memory cells (e.g., two states), while some memory cells are being verified for coarse programming, other memory cells are being verified for fine programming. With regard to multi-state memory cells, while some memory cells are being verified for coarse programming for a particular state, other memory cells are being verified for fine programming for the same particular state. In other embodiments regarding multi-state memory cells, different memory cells can be concurrently programmed/verified for different states where some memory cells are being verified for coarse programming while other memory cells are being verified for fine programming. More details of step 222 are described below. In step 224, it is determined whether all of the memory cells have verified that their threshold voltages are at the final target voltage for that memory cell. If so, the programming process is completed successfully (status=pass) in step 226. If all of the memory cells are not all verified, then it is determined whether the program counter (PC) is less than 20. If the program counter (PC) is not less than 20 (step 228), then the program process has failed (step 230). If the program counter (PC) is less than 20, then the program counter (PC) is incremented by 1 and the program voltage is stepped up to the next pulse in step 230. Subsequent to step 230, the process loops back to step 220 and the next program pulse is applied to the memory cells. V. Verification FIG. 11 provides a flow chart describing one embodiment of a process of performing coarse verification concurrently with fine verification (see step 222 of FIG. 10). In step 302 of FIG. 11, the system will check a register (or other storage device) to determine whether the particular flash memory cell is in the coarse programming mode or the fine programming mode. If the memory cell is in the coarse phase (step 304), then a coarse verification is performed in step 306. For example, looking at FIG. 9A, the memory cell could have its threshold voltage compared to voltage VLA. If the threshold voltage of the memory cell is above VLA (step 308), then the memory cell has passed the coarse verification test. If the threshold voltage of the memory cell is less VLA, then the memory cell has not passed the verification test. If the memory cell has not passed the coarse verification test, then the memory cell remains in the coarse programming mode (step 310). If the memory cell passes the coarse verification test, the memory cell will change programming modes to the fine programming mode (step 312). If, in step 304, it is determined that the memory cell was in the fine programming mode, then a fine verification process will be performed in step 320. For example, looking at FIG. 9A, the threshold voltage of the memory cell can be compared to the final target threshold voltage Vv. If the memory cell's threshold voltage is greater than the target voltage Vv (step 322), then the fine verification test has passed and the memory cell will be inhibited from programming in step 324. One embodiment for inhibiting a memory cell from further programming is to raise the bit line to Vdd. Other means for locking out a memory cell can also be used. If, in step 322, it is determined that the verification test did not pass (e.g. because the threshold voltage of the memory cell is less than target voltage Vv), then the memory cell will not be inhibited from further programming (step 326). The process in FIG. 11 is performed on an individual cell. In many embodiments, multiple cells will be programmed concurrently. Thus, the process of FIG. 11 will be performed on multiple cells concurrently. During such programming, some of the cells will be in the coarse programming process while other cells are in the fine programming process. Thus, some of the cells will perform coarse verification step 306 while other cells will perform fine verification step 320. For example, a set of cells being programmed to State 2 (see FIG. 2) may have some cells programming faster than other cells. The faster programming cells may enter the fine phase sooner. Those cells in the fine phase will have their threshold voltage compared to verified point Vv of state 2 while the memory cells in the coarse phase may have their threshold voltage compared to VLA of state 2. The process of FIG. 11 provides efficiency because at each verification step any given cell will only have a coarse verification performed or a fine verification performed, but not both. On the other hand, prior systems would do both coarse and fine verification sequentially. With one embodiment of the present invention, if the memory cell is a multi-state cell and has to test for verification for multiple states, then there will be coarse verifications for the multiple states or there will be fine verification for the multiple states. However, there will not be both coarse and fine verifications for the multiple states for a particular memory cell. For example, looking back at FIG. 3, seven verification pulses are depicted. In an eight-state memory cell, the seven verification pulses will be used for a coarse verification process or the seven verification pulses will be used for the fine verification process. In some prior art devices, if there were eight states, they would need fourteen verification pulses, seven pulses for the coarse phase and seven pulses for the fine phase. Thus, the process in FIG. 11 can reduce the number of verification pulses needed. FIG. 12 is a block diagram depicting components used to implement one embodiment of the process of FIG. 11. FIG. 12 shows a circuit for one bit line. In one embodiment, there would be such a circuit for each bit line. In another embodiment, there would be such a circuit for a pair of bit lines. FIG. 12 shows a bit line connected to switch 400 and capacitor 402. The capacitor is also connected to ground. Switch 400 receives a signal from multiplexer 404. The signal received from multiplexer 404 is used for programming. Multiplexer 404 receives two signals Vpc and Vpf, and chooses between those two signals based on an indication from C/F register 420. Switch 400 is also connected to an input of sense amplification circuit 410. The signal Vref is also connected to an input of sense amplification circuit 410. The output of sense amplification circuit 410 provides data to C/F register 420. The output of C/F register 420 provides data to multiplexer 404, lock out register 422 and multiplexer 430. Multiplexer 430 receives signals Tc and Tf, and chooses between the two signals based on the data from C/F register 420. The output of multiplexer 430 is connected to another input of sense amplification circuit 410. The operation of the components of FIG. 12 is based on a bit line discharge verification process. First, a bit line is charged. Next, a verification pulse is provided to the control gate (or steering gate) of the memory cell attached to that bit line. The bit line is then allowed to discharge. Based on the rate of discharge, it can be determined whether the memory cell is above or below a particular threshold voltage level. FIG. 13 shows a graph of bit line voltage (Vb1) versus time. In one implementation, the bit lines are allowed to discharge over a period of time T. At time T, the voltage of the bit line is compared against the reference voltage Vref. If the bit line voltage is greater than Vref, then the memory cell has a lower driving capability and is more programmed than the target threshold voltage. If at time T the bit line voltage is less than Vref, then the threshold voltage of the memory cell is less than the target threshold. In another embodiment, instead of measuring the voltage on the bit line after a fixed time T, the bit line can be allowed to discharge until it reaches Vref. Then, this discharge time is compared to a set of predetermined times to determine whether the threshold voltage is above or below the target threshold. In a cell being programmed using the coarse/fine methodology, in one embodiment the compare point can be changed between coarse and fine by having one Vref for coarse and another Vref for fine programming. In an alternative embodiment, the amount of time T can be changed so that there is one time T1 for discharge associated with coarse programming and another time T2 associated with discharging during the fine programming. In another embodiment, the pre-charging the bit line can vary such that there is one pre-charge value used for coarse programming and another pre-charge value used for fine programming. Alternatively, combinations of the above can be used. In another embodiment, a static sensing approach utilizing current comparators can be utilized. In that embodiment, the fixed reference Vref is replaced with a set of reference currents specific to coarse/fine programming. For a given memory cell, when the reference current exceeds the cell current, the associated sense amplifier will indicate a cell threshold voltage more programmed than the target voltage. Further information can be found in U.S. Pat. No. 6,222,762, which is incorporated herein by reference in its entirety. In one embodiment of the apparatus depicted in FIG. 12, C/F register 420 is a 1-bit register that indicates whether the particular memory cell is in the coarse programming mode or in the fine programming mode. During programming, if the memory cell is in the coarse programming mode, multiplexer 404 will send the coarse mode programming voltage (Vpc) to the bit line via switch 400. If the memory cell is in the fine programming mode, multiplexer 404 will send the fine mode programming voltage (Vpf) to the bit line via switch 400. During verification, sense amplifier 410 will include a circuit that compares the bit line voltage to the reference voltage Vref. During verification, if the memory cell is in the coarse mode, multiplexer 430 will select the coarse time strobe Tc based on C/F register 420. Sense amplifier 410 will determine whether the bit line discharged to the fixed reference value Vref within the time indicated by Tc. If the sense amplifier determines that the memory cell has passed the coarse verification because the bit line discharged to the fixed reference value Vref within the time indicated by Tc, then a signal will be sent to C/F register 420 to change that register to indicate that the memory cell is now in the fine programming mode. At this point, multiplexers 404 and 430 will then change their selection so that multiplexer 404 will send voltage Vpf to the bit line the next time the cell is programmed, and multiplexer 430 will send time strobe Tf to sense amplifier 410 next time there is a comparison for the verify operation. If, during the fine mode, sense amplification circuit 410 determines that the fine verification process passed successfully because the bit line discharged to the fixed reference value Vref within the time indicated by Tf, then the sense amplifier 410 will so indicate to C/F register 420, which will then cause lock out register 422 to indicate that the cell should be locked out (inhibited) from further programming. FIG. 14 is a second embodiment for performing verification. Rather than using a pair of sensing times with a fixed reference voltage for comparing the bit line voltage, a pair of reference current sources are used. For a given memory cell, when the reference current exceeds its cell current, the associated sense amplifier will indicate such a condition, reflecting that the memory cell is programmed to meet the target threshold condition. Thus, multiplexer 430 will select, based on the output of C/F register 420, whether to provide the current source for the coarse phase (Ic) or the current source of the fine phase (If). FIG. 15 depicts another alternative embodiment. In FIG. 15, multiplexer 448 will select either a reference voltage for the coarse programming phase (Vrc) or the reference voltage for the fine programming phase (Vrf) to provide to sense amplifier 410. In this embodiment, sense amplifier 410 will compare the voltage on the discharging bit line after a fixed period of time (T) to the voltage reference received from multiplexer 448, based in turn on C/F register 420. VI. Current Sinking As described above, one method for transitioning a memory cell from the coarse programming mode to the fine programming mode is to raise the voltage on the bit line. Raising the voltage on the bit line tends to slow down the programming. Thus, the threshold voltage for memory cells in the fine programming mode will be raised in smaller increments, and a tighter threshold voltage distribution can be achieved. Another means for transitioning a memory cell from the coarse programming phase to the fine programming phase is to change the amount of current through the channel of the memory cell. During programming, the source of the memory cell will rise above ground, as governed by the select gate's conduction characteristics. A current sink can be connected to the source to control how much current will flow through the channel. The greater the sinking current, the greater the current through the channel and the faster the memory cell will program. As the current sink is lowered (sinking less current), then the current in the channel will drop and the memory cell will program more slowly. For example, if the current sink is sinking 1000 nA during the coarse phase and then sinks 100 nA during the fine phase, the channel current will drop to {fraction (1/10)}th of its original value and the memory cell will program about ten times slower. FIG. 16 is a graph of relative threshold voltage increase (Vt) versus staircase control gate program pulses, following a series of 250 mV staircase control gate programming pulses with 1000 nA current sinking, thereby setting up a steady state programming condition. FIG. 16 shows five programming curves 500, 502, 504, 506 and 508 for a memory cell programmed using different current sinks. The memory cell associated with graph 500 has a current sink of 1,000 nA, continuing the steady state programming operation. The memory cell associated with curve 502 has a current sink dropped to 562 nA. The memory cell associated with curve 504 has a current sink dropped to 316 nA. The memory cell associated with curve 506 has a current sink dropped to 178 nA. The memory cell associated with curve 508 has a current sink dropped to 100 nA. As can be seen from the graphs of FIG. 16, the greater the current sink the faster the memory cell will program. For example, after a first program pulse, the memory cell associated with curve 508 has its threshold voltage increased by 20 mv, the memory cell associated with curve 506 has its threshold voltage increased by 33 mv, the memory cell associated with curve 504 has its threshold voltage increased by 68 mv, the memory cell associated with curve 502 has its threshold voltage increased by 112 mv and the memory cell associated with curve 500 has its threshold voltage increased by 234 mv, reflecting the steady state response to the 250 mV per step control gate programming staircase. After the second programming pulse, the memory cell associated with curve 508 has a threshold voltage of 47 mv, the memory cell associated with curve 506 has a threshold voltage of 90 mv, the memory cell associated with curve 504 has a threshold voltage of 159 mv and the memory cell associated with curve 502 has a threshold voltage of 270 mv. After the third programming pulse, the threshold voltage of the memory cell associated with curve 508 is 87 mv, the threshold voltage of memory cell associated with curve 506 is 159 mv and the threshold voltage of the memory cell associated with curve 504 is 271 mv. After the fourth programming step, the memory cell associated with step 508 has a threshold voltage of 144 mv and the memory cell associated with the curve 506 has a threshold voltage of 249 mv. At the fifth programming step, the threshold voltage of the memory cell associated with curve 508 is 221 mv. Consequently, as described for FIG. 16, by lowering the amount of current sinking, the rate of programming can be slowed down. Thus, in one embodiment, change between two current sinks is used to change between coarse and fine modes. For example, a coarse mode can have a large current sink (e.g., 1000 nA) and a fine mode can have a smaller current sink (e.g., 100 nA). Alternatively, the coarse mode can have no current sink, while the fine mode has a current sink to reduce the speed of programming. Other configurations can also be used. FIG. 17 depicts a memory element according to the schematic of FIG. 7, with the addition of current sink 600 connected to the right bit or control line (BL right, terminal 51′). In the implementation of FIG. 17, floating gate 56 is being programmed. In some embodiments, the control lines at 51 and 49 are both considered bit lines. In other embodiments, the control line at terminal 51 could be considered a source line or a different control line. Current sink 600 is connected to C/F register 420 (described above). In one embodiment, current sink 600 is a variable current sink. That is, current sink 600 can sink different levels of current. For example, current sink can sink two different levels of current, one level for the fine mode and another level for the coarse mode. Based on the indication from C/F register 420, the appropriate current sink value will be selected. For example, if C/F register 420 indicates that the floating gate 56′ is in the coarse mode, then the appropriate current sink for the coarse mode will be selected by current sink 600. If C/F register 420 indicates at floating gate 56′ is in the fine mode, then current sink 600 will select the appropriate sink value for the fine mode. In another embodiment, current sink 600 will only be used to sink current for the fine mode and there will be a switch between terminal 51 and ground supply to bypass current sink 600 during coarse mode. That switch would be controlled based on the value stored in C/F register 420. In the embodiment of FIG. 17, the program voltage (e.g., the staircase control gate programming voltage described above), is applied to the left steering gate 81′. In another embodiment, current sink 600 of FIG. 17 is a variable current sink that can sink different sets of coarse and fine values for each state of a multistate memory cell. For example, if there were seven programmed states, current sink 600 would be able to sink fourteen (or less if there is overlap) different levels of current. Alternatively, there can be fourteen (or less if there is overlap) different current sinks. Employing different sets of current sink values for different states allows the programming process to be more efficient so that less programming pulses are needed (e.g., 200 mV step size) and the more heavily programmed memory cells (e.g., being programmed to state 7) will program faster without causing the cells that are targeted to be programmed to lower states (e.g. being programmed to state 1) to be over programmed. One implementation of the above described scheme, may verify against all states after each programming pulse, rather than using the Smart Verify Scheme mentioned above. The table below provides an example set of current sink values. Note that two options are provided for the fine mode. A circuit designer designing the fine mode can choose either option depending on how much the designer wishes to slow down the programming in the fine mode, with Option 2 corresponding to a stronger slowing down of programming when transitioning from coarse to fine mode. Assuming a state-to-state separation of 500 mV Fine Current Sink Coarse Current Fine Current Sink Value (Option 2) State VT Sink Value (nA) Value (Option 1) (nA) (nA) 7 3.5 1000.19 409.67 167.79 6 3.0 409.67 167.79 68.73 5 2.5 167.79 68.73 28.15 4 2.0 68.73 28.15 11.53 3 1.5 28.15 11.53 4.72 2 1.0 11.53 4.72 1.93 1 0.5 4.72 1.93 0.79 State-to-state separations can be reduced to the same extent that programming distributions can be tightened, keeping the state-to-state margin the same for any two schemes that are compared. To this end, the next table depicts the range of necessary constant currents sink values to program seven states with a state-to-state separation of 400 mV. Assuming a state-to-state separation of 400 mV Coarse Fine Current Sink Fine Current Sink Current Sink Value (Option 1) Value (Option 2) State VT Value (nA) (nA) (nA) 7 2.8 1000.15 489.71 239.78 6 2.4 489.71 239.78 117.40 5 2.0 239.78 117.40 57.48 4 1.6 117.40 57.48 28.14 3 1.2 57.48 28.14 13.78 2 0.8 28.14 13.78 6.74 1 0.4 13.78 6.74 3.30 Note that the above sets of current sink values are for example purposes and many other different values can also be used depending on the particular implementation. Further note that many of the values used for current sinking in the fine mode are the same as current sink values used in the coarse mode for a different state. For example, the current sink value for state 5 of the fine mode (Option 1) and the current sink value for state 4 of the coarse mode are both 117.40 nA. This overlap can reduce the logic needed to implement this feature and, in some cases, the number or current sinks or the complexity of the current sink(s). FIG. 18 graphically depicts an alternative embodiment where the C/F register 420 is used to control switch 620. Switch 620 selects between two current sinks 622 and 624. Current sink 622 sinks current for the coarse mode and current sink 624 sinks current for the fine mode. If C/F register 420 indicates that floating gate 56 is being programmed in the coarse mode, then it will send a signal to switch 628 to choose current sink 622. If floating gate 56 is being programmed in the fine mode, then C/F register 420 will indicate to switch 620 to choose current sink 624. Thus, switching from coarse programming mode to fine programming mode is performed by switching current sinks. It is contemplated that current sink 624 for fine mode will sink less current than current sink 622 for coarse mode. FIG. 19 is a flow chart describing a process using the current sinking technology described herein. In step 650, the memory cell will start programming in the coarse programming mode. The coarse programming mode will continue until the first threshold voltage verify level is reached. In order to perform the coarse programming mode, the current sink mechanism will be set to the coarse mode current sinking setting in step 652. In some embodiments, no current sinking will be used in the coarse mode. Step 652 can include appropriately controlling current sink 600 in FIG. 17 or selecting current sink 622 in FIG. 18. Step 650 and step 652 will continue until the coarse mode is completed (which is why the arrow below step 652 is dotted). When the coarse mode is completed because the coarse verification level has been reached, fine programming mode will begin in step 654. As part of the fine programming mode, the current sink will be set to the fine mode current sinking setting in step 656. In one embodiment, step 656 includes appropriately setting current sink 600 in FIG. 17. In another embodiment, step 656 includes selecting current sink 624 in FIG. 18. The process of FIG. 19 is for one memory cell. It is contemplated that multiple memory cells will be performing the process of FIG. 19 concurrently, with some memory cells in the coarse programming mode while others are in the fine programming mode. The process of FIG. 19 concurrently with the current sinking technology described herein can be used in other types of memory cells in addition to those depicted in FIGS. 17 and 18. For example, FIGS. 17 and 18 include dual floating gates per memory cell. The current sinking technology as described herein can be used in a memory cell with only one floating gate, in which case the current sink is preferably connected to the source side of the one floating gate. The current sinking technology can also be used in memory cells with more than two floating gates. Typically, the current sink will be applied to a source side with respect to a floating gate being programmed. However, in other embodiments it can be connected to other control lines which thereby govern programming speed. For example, the designation of source and drain can be arbitrary in some structures and thus the invention is not limited to the “source” side. Note that the use of current sinks for coarse/fine programming, described above, can be combined with the concurrent coarse/fine verification process described earlier. In alternative modes, the current sink process for entering fine mode versus coarse mode can be used without the concurrent coarse/fine verification process described earlier. Additionally, the current sink technology described herein (in combination with the concurrent coarse/fine verification or without the concurrent coarse/fine verification) can be used with or without the Smart Verify process described earlier. Additionally, the Smart Verify process can also be used with the concurrent coarse/fine verification process, without using the current sinking to change between coarse/fine. VII. Charge Packet Metering Another set of embodiments for causing a memory cell to enter a fine programming mode is described with respect to FIGS. 20-25. These embodiments provide for a fine programming mode by limiting the charge available for programming a memory cell. For example, FIG. 20 shows the memory cell of FIG. 7 in a configuration where floating gate 56′ is being programmed. Attached to bit line right terminal 51 is a switch 700 that is controlled by C/F register 420. Switch 700 has two inputs. The first input is labeled by reference number 702. When C/F register 420 indicates that the floating gate 56 is in the coarse mode, the switch 700 will select input 702 which will be the normal components connected to the bit line during the coarse programming mode. That is, during coarse programming mode, in one embodiment, there is no charge packet metering. If floating gate 56 is in the fine programming mode, as indicated by C/F register 420, switch 700 will connect terminal 51 to switch 708 and capacitor 710. The opposite side of capacitor 710 is connected to a reference potential (e.g. ground). Switch 708 is connected to a pre-charge supply (e.g., voltage supply) 712. Components 708, 710 and 712 are used for the fine programming mode as part of a two step method. In the first step, capacitor 710 is connected to power supply 712 via switch 708 and charged to a pre-charge voltage, the programming source bias. In the second step, capacitor 710 is disconnected from voltage supply 712 followed by a control gate programming voltage pulse applied to the left steering gate 81′. The pre-charge voltage stored in capacitor 710 is discharged via current passed through the memory cell, and electrons are injected into floating gate 56. When the capacitor is sufficiently discharged, hot electron injection stops and programming ceases. Thus, the relative amount of charge stored on the capacitor 710 limits how much programming occurs. Less relative charge on the capacitor means that the threshold voltage will move a smaller amount. For example, a capacitor which is twice as large (e.g. 2C) pre-charged to the same voltage value stores twice the relative charge and programs twice as much as a capacitor with capacitance of C pre-charged to the same voltage value. FIG. 20 shows the components 420 and 700-712 for one bit line. In one embodiment, there is a similar set of components for each bit line. FIG. 21 provides two graphs. The upper graph shows the voltage at terminal 51 versus time. The lower graph shows the voltage at the select gate versus time. At time t0, capacitor 710 is pre-charged, thus pre-charging the control line at terminal 51. When the select gate turns on at time t1, capacitor 710 of FIG. 20 will start sinking current, and its voltage will rise, reducing current flow. Eventually, the current in the channel stops flowing when the capacitor is sufficiently discharged. FIG. 22 is a flow chart describing one embodiment of a process for performing the charge metering described above. In step 740, the appropriate pre-charge circuit is selected. In one embodiment, there is only a pre-charge circuit for the fine mode with no pre-charge circuit for the coarse mode. Further embodiments, can use a first pre-charge circuit for coarse mode and a second pre-charge circuit for fine mode. In step 742 the switch that allows pre-charging (e.g. switch 708) is closed to start the pre-charging. In step 744, the switch is opened, which ends the pre-charging. In step 746, the pulse supplied to the steering gate is applied and the select gate is turned on so that current flows through the channel and electrons are injected into the floating gate until the capacitor is sufficiently discharged. FIG. 23 provides a block drawing of an alternative embodiment which uses one pre-charge circuit for the course programming mode and another pre-charge circuit for the fine programming mode. Switch 780 is connected to terminal 51 and is controlled by C/F register 420. If C/F register 420 indicates that the floating gate 56 is in the coarse programming mode, switch 780 will select components 782, 784 and 786. If C/F register 420 indicates that the floating gate 56′ is in the fine programming mode, then switch 780 will select components 790, 792 and 794. Pre-charge supply 786 is connected to switch 782, which is connected to capacitor 784. When switch 782 is closed, pre-charge supply 786 charges capacitor 784 for the coarse programming mode. After charging capacitor 784, switch 782 is opened and capacitor 784 is allowed to discharge (via switch 780) through the memory cell to program floating gate 56′. Pre-charge supply 794 is used to pre-charge capacitor 792 when switch 790 is closed. After pre-charging capacitor 792, switch 790 is opened, thereby allowing capacitor 792 to discharge through the memory cell during the fine programming mode in order to program floating gate 56′. In one embodiment, pre-charge supply 786 will be at a lower voltage than pre-charge supply 794 so that capacitor 784 is charged to a relatively larger value for the coarse programming mode than is capacitor 792 for the fine programming mode. The greater the value of the charge on the capacitor, the more programming that will take place. Thus, more programming can be allowed for the coarse mode and less programming can be allowed for the fine mode. The exact values of the supply (voltage or other type of supply) and the capacitors are determined based on specific requirements and device optimization, simulation, and/or device characterization, as well as the targets for differentiating coarse versus fine programming. FIG. 24 provides an alternative embodiment for metering the charge within the memory cell. FIG. 24 shows C/F register 420 connected to a variable pre-charge supply 800. Pre-charge supply 800 can supply at least two different supply levels, one level for coarse programming mode and another level for fine programming mode. Based on the value in C/F register 420, the appropriate level is supplied to switch 802. Switch 802 is also connected to capacitor 804 and terminal 51′. Thus, during the coarse programming phase, pre-charge supply 800 will be used to send a coarse charging level to capacitor 804 for programming floating gate 56′. During fine programming mode, pre-charge supply 800 will provide a fine charge (of less relative magnitude than the coarse charge) for programming floating gate 56′. FIG. 25 provides yet another alternative embodiment for charge metering as described above. The embodiment of FIG. 25 includes using a common pre-charge supply 848 for both coarse and fine modes. However, switch 840 is used to select between two different capacitors. Capacitor 842 is used for programming during the coarse mode and capacitor 844, which has smaller capacitance than that of capacitor 842, is used for programming during the fine mode. Switch 840 selects between capacitor 842 and 844 based on the value stored in C/F register 420. Note that in some embodiments, pre-charging the control line (e.g. 51′) using the capacitor would bring the control line to ground. When the pulse is supplied to the steering gate, the pre-charge causes sinking of a current to the capacitor, and the voltage will rise until the device ultimately shuts itself down. As current flows into the capacitor, the voltage at terminal 51′ will increase until it reaches a sufficiently high value to effectively stop programming. This charge limited operation is performed for each pulse during programming. After each pulse is applied, the memory cell is verified. The charge packet metering technology described above can optionally be used in combination with Smart Verify process and/or the concurrent coarse/fine verify process described above. Note that in some embodiments the concurrent coarse/fine verification, current sinking during programming and charge metering during programming all contemplate a common signal (e.g. Vpgm staircase) being provided to the word line or steering gates (depending on the memory cell structure) for multiple memory cells. The foregoing detailed description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention is directed to technology for non-volatile memory. 2. Description of the Related Art Semiconductor memory devices have become more popular for use in various electronic devices. For example, non-volatile semiconductor memory is used in cellular telephones, digital cameras, personal digital assistants, mobile computing devices, non-mobile computing devices and other devices. Electrical Erasable Programmable Read Only Memory (EEPROM) and flash memory are among the most popular non-volatile semiconductor memories. Both EEPROM and flash memory utilize a floating gate that is positioned above and insulated from a channel region in a semiconductor substrate. The floating gate is positioned between source and drain regions. A control gate is provided over and insulated from the floating gate. The threshold voltage of the transistor is controlled by the amount of charge that is retained on the floating gate. That is, the minimum amount of voltage that must be applied to the control gate before the transistor is turned on to permit conduction between its source and drain is controlled by the level of charge on the floating gate. Some EEPROM and flash memory devices have a floating gate that is used to store two ranges of charges and, therefore, the memory cell can be programmed/erased between two states. When programming an EEPROM or flash memory device, typically a program voltage is applied to the control gate and the bit line is grounded. Electrons from the channel are injected into the floating gate. When electrons accumulate in the floating gate, the floating gate becomes negatively charged and the threshold voltage of the memory cell is raised. Typically, the program voltage applied to the control gate is applied as a series of pulses. The magnitude of the pulses is increased with each successive pulse by a predetermined step size (e.g. 0.2 v). In the periods between the pulses, verify operations are carried out. That is, the programming level of each cell of a group of cells being programmed in parallel is read between successive programming pulses to determine whether it is equal to or greater than a verify level to which it is being programmed. One means of verifying the programming is to test conduction at a specific compare point. The cells that are verified to be sufficiently programmed are locked out, for example in NAND cells, by raising the bit line voltage from 0 to Vdd (e.g., 2.5 volts) to stop the programming process for those cells. In some cases, the number of pulses will be limited (e.g. 20 pulses) and if a given memory cell is not completely programmed by the last pulse, then an error is assumed. In some implementations, memory cells are erased (in blocks or other units) prior to programming. More information about programming can be found in U.S. patent application Ser. No. 10/379,608, titled “Self Boosting Technique,” filed on Mar. 5, 2003; and in U.S. patent application Ser. No. 10/629,068, titled “Detecting Over Programmed Memory,” filed on Jul. 29, 2003, both applications are incorporated herein by reference in their entirety. FIG. 1 shows a program voltage signal Vpgm applied to the control gates (or, in some cases, steering gates) of flash memory cells. The program voltage signal Vpgm includes a series of pulses that increase in magnitude over time. At the start of the program pulses, the bit lines (e.g. connected to the drain) of all cells that are to be programmed are grounded, thereby, creating a voltage difference of Vpgm-0v from gate to channel. Once a cell reaches the targeted voltage (passing program verify), the respective bit line voltage is raised to Vdd so that the memory cell is in the program inhibit mode (e.g. program to that cell stops). A multi-state flash memory cell is implemented by identifying multiple, distinct allowed threshold voltage ranges separated by forbidden voltage ranges. For example, FIG. 2 shows eight threshold ranges (0, 1, 2, 3, 4, 5, 6, 7), corresponding to three bits of data. Other memory cells can use more than eight threshold ranges or less than eight threshold ranges. Each distinct threshold voltage range corresponds to predetermined values for the set of data bits. In some implementations, these data values (e.g. logical states) are assigned to the threshold ranges using a gray code assignment so that if the threshold voltage of a floating gate erroneously shifts to its neighboring physical state, only one bit will be affected. The specific relationship between the data programmed into the memory cell and the threshold voltage ranges of the cell depends upon the data encoding scheme adopted for the cells. For example, U.S. Pat. No. 6,222,762 and U.S. patent application Ser. No. 10/461,244, “Tracking Cells For A Memory System,” filed on Jun. 13, 2003, both of which are incorporated herein by reference in their entirety, describe various data encoding schemes for multi-state flash memory cells. As described above, when programming flash memory cells, between the programming pulses the memory cells are verified to see if they reached the target threshold value. One means for verifying is to apply a pulse at the word line corresponding to the target threshold value and determine whether the memory cell turns on. If so, the memory cell has reached its target threshold voltage value. For arrays of flash memory cells, many cells are verified in parallel. For arrays of multi-state flash memory cells, the memory cells will perform a verification step of each state to determine which state the memory cell is within. For example, a multi-state memory cell capable of storing data in eight states may need to perform verify operations for seven compare points. FIG. 3 shows three programming pulses 10 a , 10 b and 10 c (each of which are also depicted in FIG. 1 ). Between the programming pulses are seven verify pulses in order to perform seven verify operations. Based on the seven verify operations, the system can determine the state of the memory cells. Performing seven verify operations after each programming pulses slows down the programming process. One means for reducing the time burden of verifying is to use a more efficient verify process. For example, in U.S. patent application Ser. No. 10/314,055, “Smart Verify for Multi-State Memories,” filed Dec. 5, 2002, incorporated herein by reference in its entirety, a Smart Verify process is disclosed. In an exemplary embodiment of the write sequence for the multi-state memory during a program/verify sequence using the Smart Verify process, at the beginning of the process only the lowest state (e.g. state 1 of FIG. 2 ) of the multi-state range to which the selected memory cells are being programmed is checked during the verify phase. Once the first storage state (e.g. state 1 of FIG. 2 ) is reached by one or more of the memory cells, the next state (e.g. state 2 of FIG. 2 ) in the sequence of multi-states is added to the verify process. This next state can either be added immediately upon the fastest cells reaching this preceding state in the sequence or, since memories are generally designed to have several programming steps to move from state to state, after a delay of several cycles. The amount of delay can either be fixed or use a parameter based implementation, which allows the amount of delay to be set according to device characteristics. The adding of states to the set being checked in the verify phase continues as per above until the highest state has been added. Similarly, lower states can be removed from the verify set as all of the memory cells bound for these levels verify successfully to those target values and are locked out from further programming. In addition to programming with reasonable speed, to achieve proper data storage for a multi-state cell, the multiple ranges of threshold voltage levels of the multi-state memory cell should be separated from each other by sufficient margin so that the level of the memory cell can be programmed and read in an unambiguous manner. Additionally, a tight threshold voltage distribution is recommended. To achieve a tight threshold voltage distribution, small program steps typically have been used, thereby, programming the threshold voltage of the cells more slowly. The tighter the desired threshold distribution, the smaller the steps and the slower the programming process. One solution for achieving tight threshold distributions without unreasonably slowing down the programming process is to use a two phase programming process. The first phase, a coarse programming phase, includes attempts to raise the threshold voltage in a faster manner and paying relatively less attention to achieving a tight threshold distribution. The second phase, a fine programming phase, attempts to raise the threshold voltage in a slower manner in order to reach the target threshold voltage while also achieving a tighter threshold distribution. Example of coarse/fine programming methodologies can be found in the following patent documents that are incorporated herein by reference in their entirety: U.S. patent application Ser. No. 10/051,372, “Non-Volatile Semiconductor Memory Device Adapted to Store A Multi-Valued Data in a Single Memory Cell,” filed Jan. 22, 2002; U.S. Pat. No. 6,301,161; U.S. Pat. No. 5,712,815; U.S. Pat. No. 5,220,531; and U.S. Pat. No. 5,761,222. When verifying a memory cell during programming, some prior solutions will first perform the verify process for the coarse mode and then subsequently perform the verify process for the fine mode. Such a verification process increases the time needed for verification. The coarse/fine programming methodology can be used in conjunction with the Smart Verify process described above. As memory devices become smaller and more dense, the need for tighter threshold distributions and reasonable program times has increased. Although the coarse/fine programming methodology provides a solution to some existing issues, there is further need to improve the coarse/fine programming methodology to provide the desired tighter threshold distributions and reasonable program times. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention, roughly described, pertains to technology for non-volatile memory. More specifically, the technology described herein can be used to provide an improved coarse/fine programming methodology. One embodiment of the present invention includes an apparatus for programming non-volatile storage elements. The apparatus includes non-volatile storage elements in communication with a programming circuit and one or more verification selection circuits. The verification selection circuits cause a first subset of the non-volatile storage elements to be subjected to coarse verification concurrently while a second subset of non-volatile storage elements are subjected to fine verification. Some embodiments of the present invention include a sense circuit in communication with a non-volatile storage element, a programming mode indication circuit providing output indicating whether the non-volatile storage element is in a coarse programming mode or a fine programming mode based on the sense circuit, and a first selection circuit in communication with the programming mode indication circuit. The first selection circuit applies a coarse verification signal to the non-volatile storage element if the non-volatile storage element is in a coarse programming mode and applies a fine verification signal to the non-volatile storage element if the non-volatile storage element is in a fine programming mode. In one example of an implementation, the apparatus performs a method comprising the steps of determining whether the non-volatile storage element is in a coarse programming mode or a fine programming mode. Coarse verification is performed for the non-volatile storage element without performing fine verification on the non-volatile storage element if that non-volatile storage element is determined to be in the coarse programming mode. Fine verification is performed for that non-volatile storage element without performing coarse verification on the non-volatile storage element if that non-volatile storage element is determined to be in the fine programming mode. Another embodiment in the present invention includes a non-volatile storage element having a gate and a set of control terminals. The apparatus also includes a switchable current sinking device in communication with at least one of the control terminals. The switchable current sinking device provides a coarse current sink to the control terminal if the non-volatile storage element is in a coarse programming mode and provides a fine current sink to the control terminal if the non-volatile storage element is in a fine programming mode. In some embodiments, a current sink is provided during the fine programming mode but not during the coarse programming mode. Another embodiment of the present invention includes a sense circuit in communication with the non-volatile storage element, a programming mode indication circuit providing output indicating whether the non-volatile storage element is in a coarse programming mode or fine programming mode based on the sense circuit, and a switchable current sinking device in communication with the programming mode indication circuit and the non-volatile storage element. The switchable current sinking device provides a coarse current sink to the non-volatile storage element if the non-volatile storage element is in the coarse programming mode and provides a fine current sink to the non-volatile storage element if the non-volatile storage element is in fine programming mode. In one embodiment, an apparatus will apply a common programming signal to a gate for a non-volatile storage element, sink a first current from the non-volatile storage element during coarse programming, determine that a threshold voltage of the non-volatile storage element has reached a first verify level and switch the sinking to seek a second current in response to determining if the threshold voltage of the non-volatile storage element has reached the first verify level. Another embodiment of the present invention includes a sense circuit in communication with a non-volatile storage element, a programming mode indication circuit providing an output indicating whether the non-volatile storage element is in a coarse programming mode or a fine programming mode based on the sense circuit, and a switchable charge packet metering circuit in communication with the programming mode indication circuit and the non-volatile storage element. The switchable charge packet metering circuit provides a metered charge to the non-volatile storage element in response to the programming mode indication circuit indicating that the non-volatile storage element is in the fine programming mode. Yet another embodiment of the present invention includes a set of non-volatile storage elements and an individually switchable charge packet metering system in communication with the non-volatile storage elements. The individually switchable charge packet metering system is individually switched to provide a particular metered charge to program non-volatile storage elements in a fine programming mode without providing that particular metered charge to program non-volatile storage elements in a coarse programming mode. One embodiment includes performing a coarse programming process on the non-volatile storage elements, determining that the non-volatile storage elements should switch to a fine programming process, and performing the fine programming process in response. One implementation of the fine programming process includes the pre-charging of a control line for a non-volatile storage element and discharging that control line via the non-volatile storage element in order to program that non-volatile storage element. These and other objects and advantages of the present invention will appear more clearly from the following description in which the preferred embodiment of the invention has been set forth in conjunction with the drawings. | 20040127 | 20061121 | 20050728 | 61709.0 | 0 | HUR, JUNG H | EFFICIENT VERIFICATION FOR COARSE/FINE PROGRAMMING OF NON-VOLATILE MEMORY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,766,221 | ACCEPTED | Double wall cooking vessel | A dual wall cooking vessel is formed by the impact or friction bonding of the an inner to an outer vessel wherein a laminate of aluminum and copper layers is disposed between the outer surface of the bottom of the inner vessel and the inner surface of the bottom of the outer vessel. The aluminum layers are arranged to surround the copper layer of the uppermost aluminum layer being the upper aluminum layer being thinner than the lower aluminum layer and having a slightly smaller diameter than the copper and aluminum layer. The appropriate dimensions of the aluminum layers and sequence of welding and bonding operation results in the co-extrusion of both aluminum layers into a portion of the adjacent sidewall formed by the gap between the walls of the inner and outer vessel. This co-extruded layer s of aluminum within the side walls and the bottom of the vessel improves the heat transfer from the outer vessel to the inner vessel during cooking, but without significantly diminishing the insulating properties of the dual wall vessel that serve to keep the food warm while it is being served. | 1. A dual wall cooking vessel, the vessel comprising: a) an inner vessel having a bottom portion surrounded by vertical walls terminating at an inner rim to form an inner surface for containing fluids, b) an outer vessel having a bottom portion surrounded by vertical walls terminating at an outer rim to form an inner surface capable of containing fluids and surrounding the inner vessel, c) wherein the inner vessels is nested within the outer vessel such that the inner rim and the outer rim are concentrically aligned with each other, and a cavity is formed between the inner surface of the outer vessel and the outer surface of the inner vessel, d) a thermally conductive material interposed between the inner surface of the outer vessel and the outer surface of the inner vessel, said material bonding the inner and outer vessel together, and extending over the bottoms of the inner and outer vessel and upward to partially fill a portion of the cavity adjacent to the bottom portion of each of said inner and said outer vessel. 2. A dual wall cooking vessel according to claim 1 wherein the inner and outer rim are in contact and welded together to form a substantially hermitic cavity. 3. A dual wall cooking vessel according to claim 1 wherein the rim of the inner vessel flairs outward in a substantially vertical direction and includes a concave upward facing portion for receiving a the matting edge of a cover for the cooking vessel. 4. A dual wall cooking vessel according to claim 3 further comprising a cover that mates with the concave upward portion of the rim to form a waterless cooking vessel. 5. A dual wall cooking vessel according to claim 1 wherein the thermally conductive material comprises one or more layers of aluminum or an alloy thereof. 6. A dual wall cooking vessel according to claim 5 wherein the thermally conductive material includes copper sheet interposed between the two or more layers of aluminum. 7. A dual wall cooking vessel according to claim 1 wherein the wherein the copper sheet is perforated and the aluminum layers extend through the perforations to encapsulate the copper sheet. 8. A dual wall cooking vessel according to claim 5 wherein the aluminum layers have a combined thickness of at least about 3 mm. 9. A dual wall cooking vessel according to claim 1 wherein the thermally conductive material comprises a copper sheet interposed by two laminated sheets of aluminum, each laminate aluminum sheet comprising: a) a hard aluminum alloy inner layer, b) two layers of a softer aluminum or an alloy thereof surrounding the hard aluminum inner layer. 10. A dual wall cooking vessel according to claim 1 wherein the inner vessel is fabricated from stainless steel. 11. A dual wall cooking vessel according to claim 1 wherein the outer vessel is fabricated from stainless steel. 12. A method of forming a dual wall cooking vessel, the method comprising: a) providing a preformed internal body and a preformed external body, each body having a substantially circular bottom surface and surrounded by upward extending walls that terminate at a rim portion, b) providing a lamination assembly including; i) a lower aluminum plate having substantially the same lateral dimensions as the bottom of the preformed internal body ii) an upper aluminum plate having a smaller diameter than the lower aluminum plate, iii) the upper and lower plates having disposed there between a layer of copper sheeting, the plates being concentrically aligned with the center of gravity of the copper sheet, c) impact bonding the internal body to the external body such that at least a portion of the aluminum layers is extruded into the vertical extending cavity formed between the inner body and the outer body. 13. A method of forming a dual wall cooking vessel according to claim 12, the method further comprising the step of concentrically aligning the lamination assembly with the axis of at least one of the internal body or external body prior to said step of impact bonding and welding the concentrically aligned lamination assembly to said body at the center thereof. 14. A method of forming a dual wall cooking vessel according to claim 13, wherein the concentrically aligned lamination assembly is welded to the center of the internal and external body prior to said step of impact bonding. a) A method of forming a dual wall cooking vessel according to claim 12, the method further comprising the step of concentrically aligning the welded body and lamination assembly with the axis of the other body so that the inner body is nested within the outer body with the lamination assembly disposed there between and welding the lamination assembly to both the inner and outer body prior to said step of impact bonding. 15. A method of forming a dual wall cooking vessel according to claim 11 wherein the aluminum plate in contact with the inner surface of the outer body has a greater thickness than the aluminum plate in contact with the outer surface of the inner body. 16. A method of forming a dual wall cooking vessel according to claim 11 wherein the lower aluminum plate has a thickness greater than about 3 mm and the upper aluminum plate has a thickness of less than about 4 mm. 17. A method of forming a dual wall cooking vessel according to claim 11 wherein the copper sheet has a plurality of perforations. 18. A method of forming a dual wall cooking vessel according to claim 11 wherein at least one of the upper and lower aluminum plate is a multiple ply laminate of two or more discrete layers, at least one layer comprising aluminum or an alloy thereof 19. A method of forming a dual wall cooking vessel according to claim 11, the method further comprising the step of welding the rim portion of the internal body to the rim portion of the external body. 20. A method of forming a dual wall cooking vessel according to claim 19 further comprising trimming an annular portion of the welded upper and lower rim to form and upper rim of the dual wall vessel that seal the cavity between the inner and outer body. | BACKGROUND OF INVENTION The present invention relates to improved cooking vessels, particularly to double wall cooking vessels. Double wall cooking vessels have a solid bottom surface and a pair of concentric co-axial sidewalls separated by an air gap there between. The double wall construction provides insulation so that the food stays warm after cooking, permitting the same cookware to be used as serving ware at the table. Also known in the art is “waterless cookware”, that is a cooking vessel with a self-sealing lid so that a minimum of water is used to cook the food, with the steam generated from the added water and the foodstuff itself is retained, rather than lost through the gap between the vessel's rim and cover. The extreme example of “waterless cookware” is a pressure cooker, in which a pressure containing cooking vessel has a match lid that locks to secure a gasket between the rim and the lid. The lid must have a pressure release valve, lest the internal pressure cause a violent explosion of the vessel. The other form of “waterless cookware” involves a pot or vessel rim that extends outward from the vessel's perimeter to provide a slightly concave region where steam can condense between the extended rim and the matching lid, thus forming a “water” seal in placed of the rubber gasket in the pressure cooker. The mass of the lid serves as a “release valve” preventing excess pressure within the confined volume that holds the foodstuff. Both forms of “waterless cooking” are popular as they offer a superior method of preserving vitamins, nutrients and natural flavors, creating a more pleasing an uniform texture to the cooking food than microware methods. Double wall cookware however has certain disadvantages. The contained wall must be sealed from water for the expected lifetime of the product, as any water that enters or seeps in during use or washing presents a hazard when covert to steam during cooking. Thus the cookware is difficult to manufacture, as well as costly. Dual wall cookware also suffers in performance relative to single wall cooking vessels, as the outer surface near the bottom of the vessels is easily overheated during cooking, being insulated from the remainder of the vessel. This rapidly leads to discoloration, and distortion under extreme conditions, making the cookware unattractive for use at the table, or display in the kitchen. Accordingly, there is a need for an improved dual wall cooking vessel and method of making the same that overcomes the aforementioned disadvantages, and in particular making the vessel suitable use a “waterless cookware”. It is therefore a first object of the present invention to provide an improved construction for dual wall cookware. It is a further object for providing a reliable and cost effective method of making such an improved construction, that results in a complete an secure seal at the rim where the inner and outer walls meet. It is a further object of the invention that the securely sealing rim be suited shaped so that the vessel may serve as waterless cookware with the appropriate matching lid. SUMMARY OF INVENTION In the present invention, the first object is achieved by constructing the dual wall cookware in a manner that the lower portion of the dual adjacent the bottom of the pan is filled with a thermally conductive material. Another object of the invention is achieved by filling the lower wall portion with aluminum during the forming of the pan and attachment of a thermally conductive bottom deployed for generating a uniform temperature profile over the interior bottoms that serves as the cooking, or foodstuff contact surface. The object of achieving a suitable rim for waterless cooking is to align and weld the bottoms of the inner and outer vessels, that form the dual walls, together before friction bonding them together. This results in the precise alignment of the a previously formed inner and outer rim portions that can be consistently welded together to form the water tight seal between the inner and outer wall. The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS FIG. 1A is a cross-sectional elevation of a first embodiment of a dual wall cooking vessel. FIG. 1B is an expanded view of a portion of FIG. 1A. FIG. 2 is a cross-sectional elevation of the bottom of the vessel showing the inner and outer pans as well as the materials used to form the thermally conductive bottom prior to friction bonding. FIG. 2B illustrates the same region after friction bonding. FIG. 3A-3G illustrate via a sequence of cross-sectional elevations the steps used to construct the dual wall cooking vessel of FIG. 1. FIG. 4 is a plan view to further illustrate a preferred method of conducting the step of sealing the inner and outer wall rim portions by welding, corresponding to FIG. 3F. DETAILED DESCRIPTION In accordance with the present invention, FIG. 1 illustrates . . . thermally conductive material is interposed between inner pan 135 and outer pan 125 encompassing the bottom 200 of vessel 100. However, by fabricating the vessel 100 according to the teachings of this invention the thermally conductive material extends upward to fill the lower portion of the cavity 105 separating the outer surface 130a of the upright wall 130 of the inner pan 202 and the inner surface 120b of the upward wall 120 of the outer pan 201. As illustrated in the expanded view in FIG. 1B, marked as A, the thermally conductive material in this preferred embodiment comprises at least three layers of materials. The first layer 150 is in contact with the outer surface 135a of the inner pan, having the opposing side in contact with a middle or second layer 150. The other side of the middle layer 150 is in contact with the a first surface of the third layer 160, the other surface of layer 160 being contact with the inner surface 125b of the outer pan. As will be further illustrated with reference to FIG. 2, the middle layer generally does not extend upward into the cavity 105, thus layers 150 and 160 are connected over the extent of the cavity 105 which they partially fill, terminating at an edge 210, having a common interface therein 206. Layers 150 and 160 are preferably aluminum, or a suitable allow thereof, and surround a middle layer 150 comprising copper or a suitable allow thereof. The middle copper layer, being more thermally conductive than the surrounding aluminum layers transfer heater laterally from layer 160, such that the temperature across the inside bottom surface 135b of the inner pan 202 is uniform for cooking foodstuff, thus accommodating a range of heating methods and burner or flame configures used to heat the vessel 100 from the bottom of surface of the outer pan 125a. Referring back to FIG. 1A, the cooking vessel has an upper rim 102 formed at the termination of the edge 103 of the outer upper wall 120, with edge 104 of the inner upper wall 130. Edges 104 and 103 are preferably welded together during fabrication to prevent water from seeping in or entering cavity 105. The heati from cooking would rapidly vaporize a small quantity of water trapped in cavity 105, which may present a hazard or damage the vessel 100 in escaping rapidly therefrom. Further, edge 104 flairs outward in a substantially horizontal direction before terminating at the contact point with upper end of the inner wall 130, thus forming a sealable surface for receiving lid 110. Lid 110 has a domelike central region 112 terminating at its periphery with an edge 115 that conforms to the shape of rim 104. A slight upward facing concavity in rim 104 provides for the collection of condensed moisture therein, thus providing a sealing liquid between rim 102 and lid 110 to form a so called “waterless” cooking vessel. Lid 110 is illustrated as including an optional handle or knob 166 for ease of placement and removal from vessel 100. It should be noted that the outward extending flair of rim portion 104 also approximately defines the width of cavity 105, as wall section 103 extends in the substantially vertical direction where it intersect rim 104 at edge 102. Dual wall cooking vessel 100 also preferably includes one or more handles (not shown) disposed on the exterior side surface for grasping during cooking or serving. The method and result of friction bonding the inner and outer vessels is illustrated by the schematic expanded view of FIGS. 2A and 2B, which corresponds to region B in FIG. 1. Initially an aluminum plate 160 is disposed on the bottom surface 125b of the outer vessels 125. A copper layer in the form of a sheet or plate 140 is disposed on top of aluminum plate 160. A second aluminum plate 150 is then disposed on top of copper plate 140. Finally, the outer surface 135b of the bottom of vessel 201 is disposed on top of aluminum plate 150. As the copper plate 140 has a series perforations or holes to enhance the attachment with the surrounding aluminum plates 150 and 160, which are illustrated as a series of gaps 145. As will be further described with respect to FIG. 3, upon impact or friction bonding of the assembly in FIG. 2A the gaps 145, caused by perforations in copper plate 140, are filled as the upper surface of aluminum plate 160 has become bonded or welded to the lower surface of aluminum plate 150 at interface 205. Both the upper 150 and lower aluminum plate 160 have are essentially welded or fused to the surrounding stainless steel layers 125b and 135b respectively by the friction bonding process. Both aluminum plates 150 and 160 are reduced in thickness due to the lateral flow caused by the impact bonding, the upper aluminum plate 150 is reduced in thickness more than the lower plate 160. The preferred sequential steps used to construct a dual wall vessels from the two single wall vessels is illustrated in FIGS. 3A through 3G, inclusive. FIGS. 3A and 3B merely illustrate that the inner vessel 201 and outer vessels 202, which are initially formed of stainless steel by a drawing operation that shapes the inchoate rims 104 and 103 in shaping the upper portions proximal to the open end of each vessel. In FIG. 3C the previously described assembly of the lower aluminum plate or layer 150, copper layer 140 and upper aluminum layer 160 are spot welded via electrodes 301 (disposed on the inside of the vessel 201, and electrode 302, contacting bottom of the lower aluminum layer 150, the assembly of layer being aligned with the center of vessel 201. Preferably, each of the aluminum plates and copper plate are substantially circular corresponding to the shape of the bottom of vessel s 201 and 202, however the upper aluminum plate 150 in addition to being about half the thickness of aluminum plate 160 in this preferred embodiment also has a smaller diameter owing to its greater propensity to flow during impact bonding process illustrated by FIG. 3E. However, prior to impact bonding of the inner and outer vessels to the intervening aluminum copper layers, as shown in FIG. 3D, it is also preferable that the the inner vessel 201 and outer vessel 202 are carefully co-axially aligns such that the inchoate rim 103 of outer vessel 202 is in contact with the inchoate rim 104 of inner vessel 201. This assembly is then stabilized by spot welding at the center of the bottom of vessels 201 and 202 a shown by the presence of inner electrode 301′ and the outer electrode 302′. Thus the inner vessel 201 and outer vessel 202 is attached at the centers of their respective bottom portion 135 and 125 to aluminum later or plate 160, copper sheet 140 and aluminum plate 150. In the step portrayed by FIG. 3E the inner and outer pans are impact or friction bonded to each after first pre-heating the assembly 300e to about 500° C. o, after which a forming mandrel contacting the inner bottom surface 135b is accelerated by a driven mass downward toward the support under the bottom surface 125a of vessel assembly 300E. As the aluminum layer having the lowest melting point of the material in the assembly and have been preheated to about 80% of its melting point, the friction and heat generated by the sudden impact causes the flow and fusion of the intervening aluminum layers to each other and the remainder of the contacting layers of the vessels not previously welded together to form strong bonds there between. It should be noted in FIG. 3C that as upper aluminum layer 150 has a narrower diameter than both the copper layer 140 and the bottom aluminum layer 105 such that the force applied by the friction or impact bonding process results in a proportionately higher compressive stress on layer 150, thus causing it to extrude laterally and upward into cavity 105. As lower aluminum layer 160 also flows into cavity 105, generally surrounding and embedding copper layer 140, its flow terminates at substantially the same height as extruded aluminum layer 150 about the air-metal interface labeled 210 in FIG. 1B. Not wishing to be bound by theory, it is believed that the initial flow of layer 150 eventually equalizes the stress on both layers causing them to flow together into cavity 105. Also not wishing to be bound by theory, it is further believed that the initial and greater extrusion of layer 150 serves another purposes in that it facilitates the initial fusion bonding of layer 160 to the stainless steel bottom 125 at interface 125b, further stabilizing the friction bonding and flow of the other layers in a uniform and repeatable manner. As the fusion or friction bonding occurs in less than a fraction of a second the actual manner and operation of the invention is not certain, and hence was not readily predictable. After impact bonding as described with respect to FIG. 3E, the rim of the pan is formed in the steps illustrated by FIG. 3F and FIG. 4. In the first of a sequence of two steps, the now aligned and contacting inchoate rims of the inner 104 and outer wall 103 as welded by the electrode assembly and process illustrated further detail in FIG. 4. Counter rotating electrodes 410 and 420 substantially conform with the external shape of the inchoate rim surfaces formed during the drawing processes in the internal vessel 210 and external vessel 202 Illustrated in FIGS. 3A and 3B. Thus, complmentary shaped electrodes 400 and 420 rotating about their respective spindles 411 and 423 grasp the mating rim portion causing the rotation of the bonded assembly (which will form double wall vessel 100 shown in FIG. 3G) about its central axis 431, thus exposing the entire periphery of the rim to the welding electrodes 410 and 420. Therfore the entire periphery of the contact wall edges that form surface 103 and 104 in FIG. 1 are welded together. The welding operation thus seals cavity 105. In the second step, illustrated in FIG. 3F, the final rim shape of vessel 10 is formed by a circular cutting tool 310 that follows around the upper end of outer wall 120 of vessel 202 trimming an annulus through the weld to form the top edge 102 illustrated in FIG. 1. The thus completed double wall vessel 100 is illustrated in FIG. 3G. It should be appreciated that the aluminum layers 160 and 150 are optionally laminates of multiple layers of thinner aluminum sheet with the outer layers being selected for their ability to adhere to stainless steel, copper, the adjacent aluminum layer encountered between the gaps in the copper sheet, or alternative materials used to formed the inner and outer vessels, or a substitute heat transfer layer for the copper sheet. In a preferred embodiment the lower aluminum sheet 160 is constructed of three layers of aluminum in which aluminum alloy 3003 is surrounded by layers of aluminum alloy 1050 to provide a total thickness of 6 mm. The outer aluminum layers in this laminate preferably have thickness of about 0.2 to 0.3 mm. The upper aluminum layer 150 is similarly of a three layer construction with aluminum alloy 3003 being surrounded by sheets of aluminum alloy 1050, however the initial thickness is preferably less, or about 3.5 mm. This construction is preferred as the 3003 aluminum alloy is harder than the surrounding 1050 aluminum alloys. However, it should be appreciated that the other metals may be substituted for the inner layer of 1003 aluminum layer. The copper layer preferably has a thickness of about 0.6 mm before impact bonding. The holes or gaps in the copper layer are preferably of a diameter of about 2 to 10 mm and cover less than about 30% of the area of the sheet. After impact bonding the upper aluminum layer 150 is reduced in thickness from its initial value of about 3.5 mm to about 1.5 mm. The lower aluminum layer or plate 160 undergoes a more limited reduction of thickness, from the initial value of 6 mm to about 3 mm. The copper layer is only slightly deformed from about 0.6 mm to 0.5 mm. The surrounding inner and outer vessel walls if fabricated from stainless steel do not undergo a substantial change thickness upon impact bonding, retaining their initial thickness of about 0.5 mm. Although the copper layer is preferably of comparable dimensions to the bottom of the inner and outer vessels, it may also extend into the cavity 105 there between, as it can be initially fabricated in a bowl like shape to conform to the intended cavity shape or, being significantly thinner than the surrounding aluminum layers, is readily deformed from a plate into a bowl like shape as the inner and outer vessel are nested together in FIG. 3D. It should be appreciated that the outer surface of the outer vessel can have cladding or decorative layers outside of the stainless steel, for example one or more layers of external copper cladding optionally extends partly upward corresponding to the portion of the cavity that is filled with the aluminum layers during fusion or impact bonding. Such a contrasting external layer also serves a non-decorative function of alerting the consumer to the distinct thermal characteristics of the bottom portion of the pan, as opposed to prior art dual wall cooking vessels. While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be within the spirit and scope of the invention as defined by the appended claims. | <SOH> BACKGROUND OF INVENTION <EOH>The present invention relates to improved cooking vessels, particularly to double wall cooking vessels. Double wall cooking vessels have a solid bottom surface and a pair of concentric co-axial sidewalls separated by an air gap there between. The double wall construction provides insulation so that the food stays warm after cooking, permitting the same cookware to be used as serving ware at the table. Also known in the art is “waterless cookware”, that is a cooking vessel with a self-sealing lid so that a minimum of water is used to cook the food, with the steam generated from the added water and the foodstuff itself is retained, rather than lost through the gap between the vessel's rim and cover. The extreme example of “waterless cookware” is a pressure cooker, in which a pressure containing cooking vessel has a match lid that locks to secure a gasket between the rim and the lid. The lid must have a pressure release valve, lest the internal pressure cause a violent explosion of the vessel. The other form of “waterless cookware” involves a pot or vessel rim that extends outward from the vessel's perimeter to provide a slightly concave region where steam can condense between the extended rim and the matching lid, thus forming a “water” seal in placed of the rubber gasket in the pressure cooker. The mass of the lid serves as a “release valve” preventing excess pressure within the confined volume that holds the foodstuff. Both forms of “waterless cooking” are popular as they offer a superior method of preserving vitamins, nutrients and natural flavors, creating a more pleasing an uniform texture to the cooking food than microware methods. Double wall cookware however has certain disadvantages. The contained wall must be sealed from water for the expected lifetime of the product, as any water that enters or seeps in during use or washing presents a hazard when covert to steam during cooking. Thus the cookware is difficult to manufacture, as well as costly. Dual wall cookware also suffers in performance relative to single wall cooking vessels, as the outer surface near the bottom of the vessels is easily overheated during cooking, being insulated from the remainder of the vessel. This rapidly leads to discoloration, and distortion under extreme conditions, making the cookware unattractive for use at the table, or display in the kitchen. Accordingly, there is a need for an improved dual wall cooking vessel and method of making the same that overcomes the aforementioned disadvantages, and in particular making the vessel suitable use a “waterless cookware”. It is therefore a first object of the present invention to provide an improved construction for dual wall cookware. It is a further object for providing a reliable and cost effective method of making such an improved construction, that results in a complete an secure seal at the rim where the inner and outer walls meet. It is a further object of the invention that the securely sealing rim be suited shaped so that the vessel may serve as waterless cookware with the appropriate matching lid. | <SOH> SUMMARY OF INVENTION <EOH>In the present invention, the first object is achieved by constructing the dual wall cookware in a manner that the lower portion of the dual adjacent the bottom of the pan is filled with a thermally conductive material. Another object of the invention is achieved by filling the lower wall portion with aluminum during the forming of the pan and attachment of a thermally conductive bottom deployed for generating a uniform temperature profile over the interior bottoms that serves as the cooking, or foodstuff contact surface. The object of achieving a suitable rim for waterless cooking is to align and weld the bottoms of the inner and outer vessels, that form the dual walls, together before friction bonding them together. This results in the precise alignment of the a previously formed inner and outer rim portions that can be consistently welded together to form the water tight seal between the inner and outer wall. The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings. | 20040128 | 20060829 | 20050728 | 98500.0 | 0 | GROSSO, HARRY A | DOUBLE WALL COOKING VESSEL | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,766,294 | ACCEPTED | Systems and methods for sorting aerosols | An aerosol deflection system having a concentration zone expelling an air stream through a first detection zone, a second detection zone, and a deflection zone. The first detection zone activates the second detection zone based upon detection of a suspect aerosol of a pre-selected size. The second detection zone activates the deflection zone when the suspect aerosol of the pre-selected size has a predetermined light-induced-fluorescence signature. The deflection zone directs a pressure pulse at the suspect aerosol having the predetermined light-induced-fluorescence signature to deflect the suspect aerosol from the air stream. | 1. An aerosol deflection system comprising: a concentration zone configured to expel an air stream through a first detection zone, a second detection zone, and a deflection zone; said first detection zone configured to activate said second detection zone based upon detection of a suspect aerosol of a pre-selected size; said second detection zone configured to activate said deflection zone when said suspect aerosol of said pre-selected size has a predetermined signature; and said deflection zone configured to direct a pressure pulse at said suspect aerosol having said predetermined signature to deflect the suspect aerosol from said air stream. 2. The system of claim 1, wherein said suspect aerosol is a pathogenic biological aerosol. 3. The system of claim 2, wherein the system deflects said suspect aerosol from ambient air with an enrichment factor about 6×106. 4. The system of claim 1, further comprising a collection zone configured to collect said suspect aerosols deflected by said deflection zone, said collection zone comprising one or more pathogen identification devices configured to further analyze said suspect aerosols deflected by said deflection zone. 5. The system of claim 1, wherein said predetermined signature is a predetermined LIBS signature. 6. The system of claim 1, wherein said predetermined signature is a predetermined LIF signature. 7. The system of claim 6, wherein said second detection zone comprises: a light source configured to radiate light at said suspect aerosol of said pre-selected size; and a spectrally resolved photo-detector configured to detect a resultant LIF signature. 8. The system of claim 7, further comprising an integrated circuit in parallel communication with said spectrally resolved photo-detector, said integrated circuit having said predetermined LIF signatures resident thereon for comparison with said resultant LIF signature. 9. The system of claim 7, wherein said spectrally resolved photo-detector comprises at least two channels. 10. The system of claim 7, wherein said spectrally resolved photo-detector comprises at least thirty-two channels. 11. The system of claim 1, wherein said pressure pulse is selected from the group consisting of a positive pressure pulse, a negative pressure pulse, and any combination of the foregoing. 12. The system of claim 1, wherein said first detection zone is further configured to activate said second detection zone based upon elastic scattering signals. 13. A method for deflecting aerosols from ambient air, comprising: generating a defined stream of the ambient air; causing a suspected aerosol suspended in said defined stream to emit a signature when said suspect aerosol has a predetermined size; detecting said signature from said suspected aerosol; and removing said suspected aerosol from said defined stream via a pressure pulse when said signature is a predetermined signature. 14. The method of claim 13, further comprising removing said suspected aerosol from said defined stream in less than about 100 microseconds from the time said suspected aerosol is caused to emit said signature. 15. The method of claim 13, wherein suspected aerosols are removed from said defined stream with an enrichment factor of about 6×106. 16. The method of claim 13, further comprising analyzing said suspect aerosol after removing it from said defined stream. 17. The method of claim 13, wherein said pressure pulse is selected from the group consisting of a positive pressure pulse, a negative pressure pulse, and any combination of the foregoing. 18. The method of claim 13, further comprising receiving elastically scattered signals from at least two laser beams to determine said predetermined size. 19. The method of claim 18, wherein removing said suspected aerosol is further based on said elastically scattered signals. 20. The method of claim 13, wherein said signature is a LIBS signature or a LIF signature. | CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application Ser. No. 60/506,471 filed on Sep. 26, 2003 and the benefit of U.S. Provisional Application Ser. No. 60/448,794 filed on Feb. 20, 2003, the contents of each are incorporated by reference herein in their entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure is related to aerosol sorting. More particularly, the present disclosure is related to systems and methods for on demand sorting of pathogenic biological aerosols. 2. Description of Related Art The events of the present day have made real time detection of pathogenic biological aerosols a necessity for both civilian and military applications. For example, recent outbreaks of airborne illnesses, such as Sudden Acute Respiratory Syndrome (SARS), recent terrorist motivated biological attacks, and other events all highlight the need for real time detection and identification of pathogenic biological aerosols. As used herein, the term “aerosol” shall mean any suspension of solid or liquid particles in a gas, such as air. Thus, pathogenic biological aerosols are those airborne viruses or bacteria that cause or are capable of causing disease. Biochemical techniques exist that can identify genus and species of many biological aerosols. However, these techniques often take a long time to obtain results. Moreover, the results of these techniques are often hampered by background or ambient aerosols and, thus, detecting pathogenic biological aerosols in the wide-variety of background aerosols (usually fewer than 1 in 105) is analogous to looking for a needle in the haystack. Accordingly, it has been determined by the present application that there is a need for systems and methods that sort pathogenic aerosols from ambient air samples. SUMMARY OF THE INVENTION Systems and methods for sorting biological aerosols from ambient air in real time are provided. The present disclosure provides systems and methods for discriminating between pathogenic and non-pathogenic biological aerosols such that the pathogens can be sorted from ambient air in real time. The present disclosure also provides a compact and/or portable system and method for pathogenic biological aerosol sorting. The present disclosure also provides an efficient biological aerosol sorter having an aerodynamic deflector cued by fluorescence from the biological aerosols. The present disclosure also provides systems and methods for sorting pathogenic biological aerosols from ambient air with an enrichment factor of at least about 6×106. In one embodiment, an aerosol sorting system is provided. The system has a concentration zone configured to expel an air stream through a first detection zone, a second detection zone, and a deflection zone. The first detection zone activates the second detection zone based upon detection of a suspect aerosol of a pre-selected size. The second detection zone activates the deflection zone when the suspect aerosol of the pre-selected size has a predetermined signature. The deflection zone directs a pressure pulse at the suspect aerosol having the predetermined signature to deflect the suspect aerosol from the air stream. A method for sorting aerosols from ambient air is also provided. The method includes generating a defined stream of the ambient air; causing a suspected aerosol in the defined stream to emit a signature when the suspect aerosol has a predetermined size; detecting the signature from the suspected aerosol; and removing the suspected aerosol from the defined stream with a pressure pulse when the signature is determined to be a predetermined signature. The above-described and other features and advantages of the present disclosure will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS This patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. FIG. 1 is a side schematic view of an exemplary embodiment of a real time aerosol sorting system according to the present disclosure; FIG. 2 is a top view of a first detection zone of the system of FIG. 1; FIG. 3 is a cross sectional view of an exemplary embodiment of a deflection device according to the present disclosure; FIGS. 4 through 10 are color photographs illustrating first experimental results of the real time aerosol sorting system of FIG. 1; and FIGS. 11 through 16 are color photographs illustrating second experimental results of the real time aerosol sorting system of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the figures, and in particular to FIG. 1, an exemplary embodiment of a system 10 capable of real time sorting of pathogenic biological aerosols from an air sample is illustrated. System 10 is configured to rapidly sort aerosols having a diameter of less than about 10 micrometers (μm) from a stream of ambient air, or other gas stream as needed, based on a combination of aerosol size data and fluorescence spectrum of the aerosol. Thus, system 10 is configured to rapidly classify the aerosols in the air stream based on several measured parameters. Advantageously, system 10 is compact and/or portable, which allows the system to be used discretely in a site to be sampled, such as an airport or hospital, and allows the system to be easily moved through out the area. System 10 has at least one detection zone and at least one deflection zone. In the exemplary embodiment illustrated by FIG. 1, system 10 has a concentration zone 14, a first detection zone 16, a second detection zone 18, and a deflection zone 20. In some embodiments, system 10 can includes a collection zone 22. System 10 can also include housing 24 for enclosing one or more of zones 14-22. Preferably, housing 24 encloses all of the zones of system 10. Concentration zone 14 is configured to draw ambient air 26 into system 10 and expel the air in a stream 28. For example, concentration zone 14 can include an aerodynamic focusing nozzle 30 that expels defined stream 28 in a first direction, which is projected through zones 16-20. Stream 28 is, preferably, a laminar air stream having a diameter of about 600 micrometers (μm) and a speed of about 10 meters per second (m/s). Of course, it is contemplated by the present disclosure for stream 28 to have a larger or smaller diameter and/or speed, as well as for the stream to have laminar portions and non-laminar portions. First detection zone 16 can be configured to detect the size of the aerosols in stream 28. In a preferred embodiment, first detection zone 16 uses Doppler velocimetry (LDV) also known as laser Doppler anemometry. Here, two coherent laser beams 32, 34 with different angles of incidence and different wavelengths are focused on a sample volume 36 of stream 28. The aerosols in stream 28 simultaneously scatter light from laser beams 32, 34. One or more photo-detectors (not shown) receive the scattered light and generate a frequency representing the heterodyne difference in Doppler shift frequencies produced by aerosol motion relative to the beams. The elastic scattering signals from laser beams 32, 34 as received by the photo-detector(s) can be used to determine size and speed of the aerosols in sample volume 36. An example LDV system is disclosed in U.S. Pat. No. 5,561,515 to Hairston et al. the contents of which are incorporated by reference herein. Of course, it should be recognized that other means for detecting the size of the aerosols in stream 28 are contemplated by the present disclosure. First detection zone 16 activates second detection zone 18 upon detection of a suspect aerosol of a pre-selected size in sample volume 36. For example, when the elastic scattering signals from laser beams 32, 34 as received by the photo-detector(s) are in a predetermined voltage range (corresponding to a pre-selected aerosol size), first detection zone 16 provides a first signal 38 to activate second detection zone 18. In one embodiment of the present disclosure, sample volume 36 has a diameter that is smaller than the diameter of stream 28 as seen in FIG. 2. For example, stream 28 can have a diameter of about 600 μm and sample volume 36 can have a diameter of about 300 μm. Since sample volume 36 is smaller than stream 28, any aerosols outside of the sample volume but in the stream are not detected by first detection zone 16. Here, aerosols outside of sample volume 36 but in stream 28 do not cause first detection zone 16 to activate second detection zone 18. Of course, it is contemplated by the present disclosure for system 10 to have a sample volume 36 with a diameter that is at least equal to the diameter of the stream 28. Alternately, it is contemplated by the present disclosure for system 10 to have more than one sample volume 36 providing larger sample coverage of the diameter of the stream 28 than possible with one sample volume. Second detection zone 18 has an excitation source 40 and a detector 42. In one embodiment, second detection zone 18 uses light-induced-fluorescence (LIF). Here, excitation source 40 is a light source such as can be a laser, a light emitting diode, a lamp, and any combinations thereof and detector 42 is a spectrally resolved photo-detector such as a spectrometer, spectral filters with a photodiode, a photomultiplier tube (PMT), a photodiode array, and any combinations thereof. Second detection zone 18 performs a spectral analysis of the fluorescence of aerosols in stream 28 upon receipt of first signal 38. Advantageously, second detection zone 18 can distinguish between biological and non-biological aerosols since light-induced-fluorescence from biological aerosols have a particular fluorescence spectral finger signature. Further, system 10 can use the spectral signatures of the biological aerosols to determine if the aerosols are pathogenic or non-pathogenic. In some embodiments, system 10 can be calibrated such that the light-induced-fluorescence signature can determine if the biological aerosol is alive or dead. Second detection zone 18 can be triggered within about 3 microseconds (μs) from the time a suspect aerosol is detected by first detection zone 16. Second detection zone 18 is positioned with respect to first detection zone 16 to account for this trigger time. In the example where the speed of the stream is about 10 m/s, suspect aerosols detected by first detection zone 16 travel about 30 μm during the 3 μs trigger time. Here, light source 40 and spectrally resolved photo-detector 42 can be positioned about 30 μm below sample volume 36. Light source 40 radiates light 44 through stream 28. Light 44 can be monochromatic light, multi-spectral light, ultraviolet light, broad spectrum light, and any combinations thereof. Once activated, light 44 from light source 40 excites the biological aerosols in stream 28 to a higher energy state, causing the aerosols to emit light-induced-fluorescence from the UV to the visible. Spectrally resolved photo-detector 42 detects the light-induced-fluorescence (LIF) from the biological aerosols in stream 28. Second detection zone 18 compares the light-induced-fluorescence signature for the aerosols in stream 28 as detected by spectrally resolved photo-detector 42 to predetermined LIF signatures for one or more suspect biological aerosols. Based on this comparison, second detection zone 18 generates a second signal 46 when suspect biological aerosols are detected, where the second signal 46 is configured to activate sorting zone 20. Since system 10 generates second signal 46 based on the whole fluorescence spectrum as detected by second detection zone 18, the system is capable of distinguishing aerosols with similar fluorescence peaks, which would otherwise not be determinable using only two fluorescence bands divided by ultraviolet or visible range. In some embodiments of the present disclosure, the elastic scattering pattern from laser beams 32, 34 can be used along with or in the absence of the LIF signature to generate second signal 46. It should be recognized that second detection zone 18 is described above by way of example making use of LIF. Of course, it is contemplated by the present disclosure for second detection zone 18 to use Laser Induced Breakdown Spectroscopy (LIBS) instead of fluorescence. Here, second detection zone 18 detects plasma generation information about the aerosol composition. Advantageously, system 10 is configured to deflect the suspect aerosol into suspect portion 54 on demand. Specifically, second detection zone 18 is configured to rapidly generate second signal 46 and is positioned with respect to deflection zone 20 to account for the rapid generation time. For example, in one embodiment of the present disclosure second detection zone 18 is configured to generate second signal 46 in less than about 20 μs, more preferably less than about 14 μs, with less than about 8.7 μs being most preferred. In the example where the speed of stream 28 is about 10 m/s and the generation time is 20 μs, suspect aerosols detected by second detection zone 18 travel about 200 μm. Here, second detection zone 18 can be positioned about 200 μm from light source 40. In one embodiment of second detection zone 18 according to the present disclosure, spectrally resolved photo-detector 42 is based on a multi-channel PMT having at least two channels, more preferably at least sixteen channels, with at least thirty-two channels being most preferred. Here, second detection zone 18 includes an integrated comparison circuit 52 in parallel communication with PMT 42. Circuit 52 has resident thereon the predetermined LIF signatures for one or more suspect biological aerosols. Circuit 52 compares the light-induced-fluorescence signature detected by PMT 42 to the predetermined LIF signatures resident on the circuit and generates second signal 46 when suspect biological aerosols are detected. In this manner, second detection zone 18 mitigates the need for an external processor to perform the required comparison operation and signal generation operation. Thus, second detection zone 18 rapidly generates second signal 46, which allows system 10 to deflect suspect aerosols into suspect portion 54 in real time (i.e., on demand). Deflection zone 20 has a deflection device 48 configured selectively to emit a pressure pulse 50 towards stream 28 upon receipt of second signal 46 from second detection zone 18. Pressure pulse 50 is sufficient to deflect aerosols from stream 28. Thus, pressure pulse 50 deflects stream 28 into a suspect portion 54 and a non-suspect portion 56. In one exemplary embodiment, stream 28 has a substantially vertical (i.e., downward) direction and pressure pulse 50 has a substantially horizontal direction. Of course, it is contemplated by the present disclosure for stream 28 and/or pressure pulse 50 to have any desired direction, where the pressure pulse can impinge on the stream. Advantageously, deflection zone 20 enables system 10 to be more compact and/or portable, less destructive to the deflected aerosols, and more independent of the condition of ambient air 26 than previously possible. Devices that electrostatically sort aerosols suspended in a flowing fluid, such as flow cytometry devices, are known. Here, aerosols to be sorted are suspended in a fluid, charged to a known electrical state, and then subsequently deflected based on that electrical state. Thus, electrostatic sorting devices require both a charging device and a deflecting device, which are larger than the simple deflection device 48 of system 10. Consequently, system 10 can be substantially smaller and more compact as compared to electrostatic deflection devices. It has also been determined that deflection device 48 is less destructive than electrostatic deflection as it does not change the electrical state of the aerosols. Thus, it has been determined that system 10 mitigates damage to the deflected aerosols in stream 28. Further, it has been found that deflection device 48 is more robust to changing conditions in ambient air 26. For example, the electrical state used in electrostatic deflection can be dependent on various physical properties of the aerosols, as well as the properties of ambient air 26, such as humidity and temperature. Advantageously, system 10 also configured to mitigate deflection of surrounding non-suspect aerosols into suspect portion 54. For example, system 10 rapidly cycles a tightly focus pressure pulse to deflect as few aerosols as possible from stream 28. Referring now to FIG. 3, an exemplary embodiment of deflection device 48 having a rapid cycle time is illustrated. Here, deflection device 48 is a piezoelectric pulsed valve having a piezoelectric disk 58 in electrical communication with a power supply 60. Disk 58 is configured to move a valve rod 62 along direction 64 in response to the application of power from power supply 60. In an exemplary embodiment, disk 58 has a diameter of about 2 inches. Deflection device 48 also has a pressure source 66 feeding a nozzle 68. Rod 62 has a first position closing nozzle 68 such that pressure source 66 is not in fluid communication with the nozzle, preventing deflection device 48 from emitting pressure pulse 50. Rod 62 also has a second position (not shown) such that pressure source 66 is in fluid communication with the nozzle, causing deflection device 48 to emit pressure pulse 50. In this manner, deflection device 48 is configured to emit pressure pulse 50 having about 18 pounds per square inch (psi), which has been found to be sufficient to deflect stream 28 into suspect portion 54 and non-suspect portion 56. Deflection device 48 is configured to focus pressure pulse 50 to diameter of about 500 μm, which allows the pressure pulse to propagate several millimeters from the nozzle. In addition, deflection device 48 emits pressure pulse 50 for a very short duration of about 60 μs (microseconds). Thus, pressure pulse 50 is well-localized and causes a very short interruption in stream 28, which ensures that as few aerosols proximate to the suspected aerosol are deflected from the stream 28. Specifically, pressure pulse 50 is configured to deflect suspect portion 54 from stream 28 equal to: □R2v(t), where R is the radius of stream 28, v is the velocity of the stream, and t is the duration of pressure pulse 50. For example, assume that stream 28 has one suspect aerosol entrained in 100,000 aerosols per liter, a radius of 300 μm, and a velocity of 10 m/s. Also, assume that pressure pulse 50 has a duration of 60 μs. Therefore, suspect portion 54 has a volume of about 1.7×10−7 liters, which correlates to about 1.7×10−2 aerosols. After this procedure one biological aerosol is detected within 1.7×10−2 aerosol particles which is to be compared to the initial concentration of one biological aerosol in 100,000. The enrichment factor is therefore 100,000/1.7×10−2=6×106. In addition, deflection device 48 has a response time of less than about 20 μs from the time that it receives second signal 46. Because the suspect aerosols do not need to pass through a charging area with a long delay, and the response time of deflection device 48 is less than 20 μs, system 10 is configured to precisely deflect a suspect aerosol within 200 μm (micrometers) from the time when second detection zone 18 provides second signal 46. Again, system 10 can be substantially smaller and more compact as compared to electrostatic deflection devices. In one embodiment, second detection zone 18 generates second signal 46 in less than about 20 μs from the time when the suspected aerosol is excited by light 44, deflection zone 20 begins deflecting the suspected aerosol in less than about 20 μs from receipt of the second signal, and completes the deflection in about 60 μs. Accordingly, system 10 radiates and deflects suspected aerosols from steam 28 in less than about 100 μs. The compact nature of system 10 results from this rapid response time. Further, system 10 provides the desired enrichment factor as a result of this rapid response time. Further, deflection device 48 is configured to cycle from open, to closed, to open in about 60 μs. Thus, deflection zone 20 can selectively deflect aerosols that are about 500 μm apart from one another since stream 28 has a velocity of 10 m/s. It should be recognized that system 10 is described above by way of example deflecting the suspect aerosols from stream 28 using one positive pressure deflection device 48 to push the suspect aerosol from the stream. Of course, it is contemplated by the present disclosure for system 10 have more than one deflection device 48. It is also contemplated by the present disclosure for system 10 to deflect non-suspect aerosols from stream 28, thus leaving any suspect aerosols in the stream for further processing. It is also contemplated by the present disclosure for system 10 to deflect aerosols (suspect or non-suspect) from stream 28 using a negative pressure pulse to pull the suspect aerosol from the stream. Further, it is contemplated by the present disclosure for system 10 to deflect aerosols from stream 28 using a combination of negative and positive pressure to push and pull the various aerosols in desired directions. Moreover, it is contemplated by the present disclosure for system 10 to modify the deflection force and/or deflection direction based the type of aerosol detected. Here, system 10 can deflect a first type of aerosol to a first location, but a second type of aerosol to a second location. Accordingly, deflection zone 20 is configured to deflect suspect portion 54 from non-suspect portion 56. In one embodiment, collection zone 22 collects suspect portion 54 for further analysis and/or pathogen identification. Here, the enrichment of stream 28 by the aforementioned enrichment factor serves to make further analysis and/or pathogen identification of suspect portion 54 easier, more reliable, and/or faster than possible when using only ambient air 26. For example, collection zone 16 can include one or more devices (not shown) providing for further analysis and/or pathogen identification using methods, such as, but not limited to, biochemical assays, spectroscopic techniques (Raman or FTIR), and others. If using only ambient air 26, the large quantity of background aerosols could contaminate the reactions, disable the biochemical assays, mask the Raman and IR peaks, and other deleterious effects. In contrast, use of enriched suspect portion 54 mitigates one or more of the aforementioned deleterious effects. In other embodiments, collection zone 22 collects both suspect portion 54 and non-suspect portion 56. In still other embodiments, collection zone 22 collects only non-suspect portion 56 and, thus, system 10 acts to filter the suspect aerosols from ambient air 26. Experimental Results—Test #1 A mixture having about 85% of non-suspect aerosols and about 15% of suspect biological aerosols was used to test system 10. Tryptophan aerosols were used as suspect biological aerosols, while riboflavin (RBF) was used as the background or non-suspect aerosols. The aerosols of tryptophan and RBF were obtained using ink-jet aerosol generators and mixed to flow into the aerosol stream. The results of this first test are illustrated in FIGS. 4 through 10. Collection zone 22 included a microscope glass slide positioned one centimeter (cm) beneath nozzle 30 for collecting suspect portion 54 in a first area 70 and non-suspect portion 56 in a second area 72. A fluorescence microscope (Olympus BX60) and a color digital camera (Diagnostic Instruments Inc. 2.2.0) were used to image the collected aerosols when illuminated by a UV light source and a weak background white light such that tryptophan exhibits a blue color with a round shape, while RBF exhibits a yellow color with a needle-like crystalline shape. FIG. 4 illustrates the entire collection zone 22, which includes both first and second areas 70, 72. FIGS. 5 through 7 illustrate, at increasing magnification levels, the aerosols collected in first area 70, while FIGS. 8 through 10 illustrate, at increasing magnification levels, the aerosols collected in second area 72. As can be seen, most of the aerosols remaining in first area 70 are RBF aerosols, namely non-suspect portion 56. However, the tryptophan aerosols (i.e., suspect portion 54) are primarily located in second area 72, which is defined along the direction of pressure pulse 50. As seen in FIG. 9, the highest density of tryptophan aerosols in second area 72 is found at about 2 millimeters (mm) from the center of the RBF aerosols in first area 70. Only a few RBF aerosols are deflected 1 mm away from the center and substantially none beyond the 1 mm distance. By counting the concentration ratio of tryptophan to RBF aerosols in second area 72 beyond 1 mm, the result shows that the enriching factor is higher than 104 in this test In the tested embodiment of system 10, sample volume 36 has a smaller diameter (i.e., 300 μm) than the diameter of stream 28 (i.e., 600 μm). Thus, any aerosols outside of sample volume 36 but in stream 28 were not detected by first detection zone 16. This creates a high density of undeflected tryptophan aerosols around the central RBF aerosols in first area 70 as best seen at the right side of FIG. 5, about 400 μm from the center of the first area. Experimental Results—Test #2 A second mixture having about 85% of non-suspect aerosols and about 15% of suspect biological aerosols was also used to test system 10. In this test, Bacillus subtilis (“BG”) or tryptophan aerosols were used as suspect biological aerosols, where BG is used to simulate anthrax. Arizona road dust (ARD), riboflavin (RBF), or sodium chlorine (NaCl) were used as background or non-suspect aerosols. ARD is one of the standard background aerosols. RBF is a biological material but has a shape and fluorescence spectrum different from BG aerosols. NaCl has a shape similar to the suspect aerosols. The mixed aerosols from one of the suspect aerosols and one of the background aerosols were obtained by combining the outputs of two ink-jet aerosol generators. The results of this second test are illustrated in FIGS. 11 through 16. Here, the fluorescent aerosols (e.g., BG, RBF, and tryptophan) are observed by their fluorescence images induced by UV lamp illumination, while ARD and NaCl aerosols are observed with an additional white light illumination. FIGS. 11 through 13 illustrate that the center of non-suspect portion 56 is dominated by ARD, RBF, or NaCl aerosols. Conversely, FIGS. 14 through 16 illustrate that 2 mm from the center of non-suspect portion 56 along the direction of the pressure pulse is mainly occupied by the suspect portion 54 of BG or tryptophan. Accordingly, system 10 sorts suspect aerosols based on their similar LIF fingerprint, despite background aerosol fluorescence or aerosols similarly shaped to the BG aerosols. The counting results show that all enrichment factors are higher than 104. Accordingly and as set forth herein, system 10 combines rapid aerodynamic or pressure based sorting with two or more rapid detection zones to provide selective and efficient sorting of potentially pathogenic biological aerosols from background aerosols. System 10 can also be used to deflect aerosols depending on properties other than fluorescence, such as aerosol size, morphology from elastic scattering patterns, and any combinations thereof. It should be noted that the terms “first”, “second”, “third”, “upper”, “lower”, and the like may be used herein to modify various elements. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated. It should also be noted that the ranges provided herein, if any, are meant to include all subranges therebetween unless specifically stated to the contrary. While the present disclosure has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment(s) disclosed as the best mode contemplated, but that the disclosure will include all embodiments falling within the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present disclosure is related to aerosol sorting. More particularly, the present disclosure is related to systems and methods for on demand sorting of pathogenic biological aerosols. 2. Description of Related Art The events of the present day have made real time detection of pathogenic biological aerosols a necessity for both civilian and military applications. For example, recent outbreaks of airborne illnesses, such as Sudden Acute Respiratory Syndrome (SARS), recent terrorist motivated biological attacks, and other events all highlight the need for real time detection and identification of pathogenic biological aerosols. As used herein, the term “aerosol” shall mean any suspension of solid or liquid particles in a gas, such as air. Thus, pathogenic biological aerosols are those airborne viruses or bacteria that cause or are capable of causing disease. Biochemical techniques exist that can identify genus and species of many biological aerosols. However, these techniques often take a long time to obtain results. Moreover, the results of these techniques are often hampered by background or ambient aerosols and, thus, detecting pathogenic biological aerosols in the wide-variety of background aerosols (usually fewer than 1 in 10 5 ) is analogous to looking for a needle in the haystack. Accordingly, it has been determined by the present application that there is a need for systems and methods that sort pathogenic aerosols from ambient air samples. | <SOH> SUMMARY OF THE INVENTION <EOH>Systems and methods for sorting biological aerosols from ambient air in real time are provided. The present disclosure provides systems and methods for discriminating between pathogenic and non-pathogenic biological aerosols such that the pathogens can be sorted from ambient air in real time. The present disclosure also provides a compact and/or portable system and method for pathogenic biological aerosol sorting. The present disclosure also provides an efficient biological aerosol sorter having an aerodynamic deflector cued by fluorescence from the biological aerosols. The present disclosure also provides systems and methods for sorting pathogenic biological aerosols from ambient air with an enrichment factor of at least about 6×10 6 . In one embodiment, an aerosol sorting system is provided. The system has a concentration zone configured to expel an air stream through a first detection zone, a second detection zone, and a deflection zone. The first detection zone activates the second detection zone based upon detection of a suspect aerosol of a pre-selected size. The second detection zone activates the deflection zone when the suspect aerosol of the pre-selected size has a predetermined signature. The deflection zone directs a pressure pulse at the suspect aerosol having the predetermined signature to deflect the suspect aerosol from the air stream. A method for sorting aerosols from ambient air is also provided. The method includes generating a defined stream of the ambient air; causing a suspected aerosol in the defined stream to emit a signature when the suspect aerosol has a predetermined size; detecting the signature from the suspected aerosol; and removing the suspected aerosol from the defined stream with a pressure pulse when the signature is determined to be a predetermined signature. The above-described and other features and advantages of the present disclosure will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims. | 20040128 | 20070313 | 20050210 | 84356.0 | 0 | NGUYEN, TU T | SYSTEMS AND METHODS FOR SORTING AEROSOLS | SMALL | 0 | ACCEPTED | 2,004 |
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10,766,516 | ACCEPTED | Sheet material clamp | A sheet material clamp having a rigid clamp base of a pre-selected length. The rigid clamp base has a clamping surface and at least two clamping apparatus attached to the clamping base for applying clamping pressure through a pressure foot toward the clamping surface. The apparatus for applying clamping pressure are spaced along the length of the clamp base so that clamping pressure can be applied evenly along the edge of the sheet material being clamped. | 1. A sheet material clamp comprising: a rigid clamp base having a select length and a clamping surface; at least two means for applying clamping pressure attached to the rigid clamp base, the means for applying clamping pressure being spaced along the length of the rigid clamp base; and a pressure foot operatively associated with each means for applying clamping pressure, the pressure foot configured such that actuation of the means for applying clamping pressure drives the pressure foot toward the clamping surface. 2. The sheet material clamp of claim 1 wherein each means for applying clamping pressure is fixedly attached to the rigid clamp base. 3. The sheet material clamp of claim 1 wherein the means for applying clamping pressure is attached to the rigid clamp base in a manner enabling it to move lengthwise relative to the clamp base. 4. The sheet material clamp of claim 1 wherein each means for applying clamping pressure comprises: a female threaded socket formed in a clamping frame; a mating male threaded shaft, threaded through the female threaded socket, the male threaded shaft having a first end operatively associated with the pressure foot, and a second end opposite the first end; and a handle operatively associated with the second end of the male threaded shaft configured such that rotation of the handle can drive the pressure foot toward the clamping surface. 5. The sheet material clamp of claim 1 wherein each means for applying clamping pressure comprises: an actuator; a drive shaft operatively associated with the actuator; and the pressure foot being operatively associated with the drive shaft such that actuation of the actuator advances the drive shaft and thereby drives the pressure foot toward the clamping surface. 6. The sheet material clamp of claim 5 wherein each actuator is fluid driven. 7. The sheet material clamp of claim 5 wherein each actuator is fluid driven and part of the same fluid circuit, whereby each actuator is substantially simultaneously actuated by application of fluid pressure to the circuit. 8. The sheet material clamp of claim 1 wherein the clamp base is a substantially elongate rectangular bar. 9. The sheet material clamp of claim 4 wherein the clamp base is a substantially elongate rectangular bar. 10. The sheet material clamp of claim 5 wherein the clamp base is a substantially elongate rectangular bar. 11. The sheet material clamp of claim 1 wherein the clamp base is a channel member having a channel opening sized to receive at least two juxtaposed sheets of sheet material therein. 12. The sheet material clamp of claim 4 wherein the clamp base is a channel member having a channel opening sized to receive at least two juxtaposed sheets of sheet material therein. 13. The sheet material clamp of claim 5 wherein the clamp base is a channel member having a channel opening sized to receive at least two juxtaposed sheets of sheet material therein. 14. The sheet material clamp of claim 1 wherein the clamp base comprises at least two lengthwise clamp base segments each having a clamping surface joined in series by a hinge, whereby lengthwise segments are pivotable lengthwise relative to each other while maintaining each clamping surface substantially coplanar. 15. The sheet material clamp of claim 8 wherein the clamp base comprises at least two lengthwise clamp base segments each having a clamping surface joined in series by a hinge, whereby lengthwise segments are pivotable lengthwise relative to each other while maintaining each clamping surface substantially coplanar. 16. The sheet material clamp of claim 11 wherein the clamp base comprises at least two lengthwise clamp base segments each having a clamping surface joined in series by a hinge, whereby lengthwise segments are pivotable lengthwise relative to each other while maintaining each clamping surface substantially coplanar. 17. The sheet material clamp of claim 16 where a hinge is operatively associated with each clamp base segment on opposite sides of the channel opening. 18. The sheet material clamp of claim 14 wherein at least one means for applying clamping pressure is attached to each clamp base segment. 19. The sheet material clamp of claim 18 wherein each means for applying clamping pressure comprises: a female threaded socket formed in a clamping frame; a mating male threaded shaft, threaded through the female threaded socket, the male threaded shaft having a first end operatively associated with the pressure foot, and a second end opposite the first end; and a handle operatively associated with the second end of the male threaded shaft configured such that rotation of the handle can drive the pressure foot toward the clamping surface. 20. The sheet material clamp of claim 18 wherein each means for applying clamping pressure comprises: an actuator; a drive shaft operatively associated with the actuator; and the pressure foot being operatively associated with the drive shaft such that actuation of the actuator advances the drive shaft and thereby drives the pressure foot toward the clamping surface. | RELATED APPLICATIONS This application claims priority from U.S. Provisional Patent Application Ser. No. 60/442,856, filed Jan. 27, 2003, entitled “Sheet Material Clamp.” BACKGROUND OF THE INVENTION 1. Technical Field The present invention is directed toward a sheet material clamp and more particularly toward a sheet material clamp with multiple clamping structures positioned lengthwise along a clamping surface. 2. Background Art It is customary in the building and construction trades to install countertops in various residential and commercial building locations such as kitchens, bathrooms or office workspaces. Relatively simple countertop designs can be fabricated offsite and installed by a finish carpenter as delivered. In the alternative, more highly specialized countertops are often fabricated from sheet materials onsite as part of the installation process. This second onsite method of installation and fabrication is typically used in more highly customized applications such as luxury homes. Custom countertops which are fabricated onsite can be created from laminated wood products, stone or specialized plastic sheet materials. In many installations it is desired to bond a double thickness of the sheet material being used to the front edge of the countertop. The double thickness material along the front edge of a countertop can provide a more durable and aesthetically appealing edge surface toward the living or high use area. In addition, the use of a relatively thin length of material to form the double thickness edge can provide a significant overall savings of material costs. Typically, the two portions of sheet material which are being bound together to form a double thickness edge are affixed to each other with an adhesive specially formulated for the material in use. Clamping pressure must be applied along the front edge of the countertop to assure that the sheet materials being bound are held in close proximity while the adhesive sets. A row of C-clamps along the countertop edge can be used to apply the necessary clamping pressure. However, the use of C-clamps in this application can be difficult since numerous separate clamps must be applied along the countertop edge and it can be difficult to get an even application of pressure along the edge with a series of individual clamps. In addition the installation of individual clamps requires the countertop craftsman to position and tighten multiple clamps quickly as appropriate clamping pressure must be applied before the adhesive begins to set. It is quite possible through the inexpert use of C-clamps to ruin a countertop edge by not applying pressure evenly and quickly enough. In many custom countertops, the countertops have curved edges and the curved edges can vary from inner and outer radii or corners and straight edges. These complicated edge configurations can further enhance the risk of ruining countertop edges by not applying suitable pressure. The present invention is directed toward overcoming one or more of the problems discussed above. SUMMARY OF THE INVENTION One aspect of the present invention is a sheet material clamp having a rigid clamp base of a pre-selected length. The length of the clamp base should substantially equal or exceed the length of the countertop edge being clamped. The rigid clamp base has a clamping surface running along its length and at least two clamping apparatus rigidly bonded to the clamping base. The clamping apparatus function by applying clamping pressure through a pressure foot toward the clamping surface. The apparatus for applying clamping pressure are preferably spaced along the length of the clamp base so that clamping pressure will be applied evenly along the edge of the countertop being fabricated. The apparatus for applying clamping pressure can feature a captive C-clamp type design with a female threaded socket formed in a claming frame and a mating male threaded shaft. The male shaft can be attached at one end to the pressure foot and have a handle associated with the other end. In this configuration turning the handle similar to the operation of a C-clamp will drive the pressure foot toward the clamping surface. Alternatively the apparatus for applying clamping pressure can be a fluid driven actuator such as a hydraulic or pneumatic cylinder, or alternatively an electromechanical motor. The actuator can be operatively associated with a shaft connected to the pressure foot so that application of power to the actuator drives the pressure foot toward the clamping surface. In a highly preferred embodiment, the rigid clamp base consists of a number of lengthwise segments joined in series by hinges that enable pivotal movement of the various lengthwise segments relative to one another. The rigid clamp base can be made of a substantially elongate rectangular bar or a channel member having a channel opening sized to receive layered sheet material to be clamped, and either the rectangular bar or the channel member can be divided into lengthwise segments and joined by hinges as described above. The present invention provides a sheet material clamp which can be used to efficiently and quickly apply clamping pressure to two lengthwise portions of sheet material which are being bonded together. In addition, the sheet material clamp is optimized to provide pressure which is evenly distributed along the length of the materials being bonded. Furthermore, the present invention provides a clamp structure that can quickly clamp edges having inner or outer corners or radii. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the sheet material clamp featuring manually actuated clamping means; FIG. 2 is a perspective view of the sheet material clamp featuring fluid actuated clamping means; FIG. 3 is perspective view of an alternate embodiment of the sheet material clamp featuring manually actuated clamping means of FIG. 1 with the base broken into lengthwise segments; and FIG. 4 is a perspective view of an alternate embodiment of the sheet material clamp featuring fluid actuated clamping means of FIG. 2 broken into lengthwise segments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A sheet material clamp 10 includes a rigid clamp base 12 having a select length 14 and a clamping surface 16. As shown in FIG. 1 the rigid clamp base 12 can be a substantially elongate rectangular bar to which clamping structures 18 are attached at specified intervals along the rigid clamp base 12. In the alternative, as shown in FIG. 2, the rigid clamp base 12 can be fabricated as a channel member having a channel opening 13 sized to receive layered sheet material which will be clamped within the interior of the channel. As illustrated in FIGS. 1 and 2, the clamping structures are rigidly attached to the clamp base at select intervals. Alternatively, the clamping structures can be attached in a manner that enables them to slide lengthwise relative to the rigid clamp base 12. For example, each clamping structure could be mounted in a lengthwise groove in a rail on the clamp base 12, as discussed below with reference to FIGS. 3 and 4. In either embodiment the length 14 of the rigid clamp base 12 preferably should equal or exceed the length of the sheet material edge being clamped. Alternatively, multiple sheet material clamps can be used in series where the length of the sheet material edge being clamped exceeds the length 14. In one embodiment of the present invention clamping pressure is applied by use of a manual clamping system 20. This embodiment is depicted in FIG. 1. In a preferred embodiment of the present invention clamping pressure is applied automatically and simultaneously at each clamping point by use of an automatic clamping system 22. This embodiment is shown in FIG. 2. It is important to note that although the manual clamping system 20 is shown with a bar type rigid clamp base 12, and the automatic clamping system 22 is shown with a channel type rigid clamp base 12, either type of clamping system can be used with either type base 12. Referring again to FIG. 1, the manual clamping system 20 consists of a female threaded socket 24 formed in the portion of the clamping structure 18 opposite the clamping surface 16. In addition a male threaded shaft 26 is matingly engaged with the female threaded socket 24. The threaded shaft 26 when engaged in the operative position has a first end 28 facing toward the clamping surface 16. The first end 28 of the threaded shaft 26 is operatively associated with a pressure foot 30. The male shaft 26 has in addition a second end 32 opposite the first end 28. The second end 32 of the male shaft 26 is operatively associated with a handle 34. As depicted in FIG. 2, the automatic clamping system 22 also features a pressure foot 30 which is attached to a drive shaft 36. The drive shaft 36 is operatively associated with a fluid driven actuator 38 which can be a pneumatic or hydraulic device. That is, as used herein, “fluid” means any suitable compressible gas or incompressible liquid, depending upon whether the system is pneumatic or hydraulic. Fluid is supplied to the fluid driven actuator 38 by supply line 40. In addition a supplemental tightening device 42, consisting of a shaft 44 and knob (or nut) 46 can be associated with each fluid driven actuator 38. In an alternative analogous embodiment not shown on FIG. 1 or FIG. 2, the automatic clamping system 22 could consist of an electromechanical actuation device or any other type of actuator for selectively advancing the pressure foot 30. With the sheet material clamp 10 assembled as described above, the system functions as follows: Two elongate pieces of sheet material stock 48, 50, (typically with one 48 being significantly narrower than the other 50) are positioned juxtaposed for bonding as shown in phantom lines in FIG. 1, forming a double thickness edge. Adhesive is applied to the bonding surfaces of one or both pieces of sheet material 48, 50. If the manual sheet material clamp of FIG. 1 is employed, the handle 34 associated with each male threaded shaft 26 is rotated in the clockwise or counterclockwise direction, as is necessary to back the pressure foot 30 away from the clamping surface 16 a sufficient distance to allow placement of the sheet material clamp 10 over the two pieces of sheet material which are to be bound. The handle 34 is then rotated in a clockwise or counterclockwise direction as is necessary to advance the male threaded shaft 26 and associated pressure foot 30 toward the clamping surface, thereby applying clamping pressure to the two pieces of sheet material received between the clamping surface 16 and the pressure foot 30. Care must be taken by the craftsman applying the clamp 10 to assure that even pressure is applied along the length of the countertop edge. An alternative preferred embodiment features use of the automatic clamping system 22 as shown in FIG. 2. In this embodiment, the pressure foot 30 and associated drive shaft 36 are backed either manually or automatically into the fluid driven actuator 38 opening a space between the pressure foot 30 and the clamping surface 16 wide enough to receive the double thickness countertop edge 48, 50. The sheet material clamp 10 is placed over the double thickness countertop edge with the edge being received within the channel of the rigid clamping base 12 as depicted in FIG. 2. At this point, pressure is applied to each pressure foot 30 simultaneously by actuation of each interconnected fluid drive actuator 38, thereby applying clamping pressure to the double thickness countertop edge received between the pressure foot 30 and the clamping surface 16. In addition, it may be desirable to apply clamping pressure to the sheet materials received within the clamp in excess of that generated by the fluid driven actuator 38. In such case the craftsman can apply supplement pressure by tightening the supplemental tightening device 42 associated with each automatic clamping system 22. FIG. 3 depicts a manual clamping system similar to FIG. 1, although differing in that the rigid clamp base 12 is broken into a number of lengthwise clamp base segments, 12A, 12B and 12C, each having a clamping surface 16 joined in series by a hinge 60 so that lengthwise segments 12A, 12B and 12C are pivotable relative to each other while maintaining the clamping surfaces 16 substantially coplanar. The hinge 60 preferably consists of a plate 62 that is attached to each of the adjacent lengthwise segments by a bolt 64 or some other known attachment device enabling the various lengthwise segments 12A, 12B and 12C to pivot relative to the plate 62 and each other. The bolt 64 preferably does not protrude through surface 16. Referring further to FIG. 3, and in particular to lengthwise segment 12A, each lengthwise segment may be provided with a T-shaped groove 66 in a surface opposite the clamping surface 16. In this embodiment, each clamping structure 18 has a foot (not shown) configured to be received within the T-shaped slot 66 so as to slide lengthwise of the segment without becoming detached from the segment. Ideally a weld or some other obstruction would be provided at each end of the T-shaped groove 66 to prevent the clamping structure 18 from sliding out lengthwise from the T-shaped groove 66. As shown in FIG. 3, lengthwise segments 12A and 12B are substantially the same length. Numerous other segments of substantially the same length could be attached in series with segments 12A and 12B as desired. 12C is shown being greater length than 12A or 12B. 12C could be of any desired length and have a number of clamping structures 18 associated therewith, basically having a configuration identical to that illustrated in FIG. 1. In this manner, the embodiment illustrated in FIG. 3 can be used for clamping sheet material stock 48, 50 having a straight edge as illustrated in FIG. 1 or having inside or outside curved edges so as to accommodate virtually any edge curvature or inside or outside corners. FIG. 4 is somewhat similar to FIG. 2 although it is modified by the channel member being in lengthwise segments joined by hinges 60 in the same manner and for the same purpose as discussed above with respect to FIG. 3. While FIG. 4 shows a top and bottom hinge, a single top or bottom hinge or a back plate hinge are within the spirit of the invention. The plates 62 are similarly attached by bolts 64 to allow pivoting between the lengthwise segments 12A, 12B and 12C. As likewise described above with respect to FIG. 3, the bolts or pivotal attachments 64 are attached in a manner to prevent interference with the substantially coplanar clamping surfaces 16. For example, as seen in FIG. 4, the bolt or attachment structure 64 could be a pin 67 received in a countersunk bore 68 and secured therein with a cotter pin 70, all of which resides within the countersunk bore below the clamping surface 16. Other suitable hinge structures could be substituted. In the embodiment illustrated in FIG. 4, the automatic clamping system 22 allows each of the clamps to be simultaneously actuated. Referring to segment 12A, a lengthwise slot 72 may receive an automatic clamping system 22 to allow the automatic clamping system 22 to slide lengthwise of the segment 12A. Such a slot could be provided in each of the segments 12A, 12B and 12C to allow the automatic clamping systems to be moved lengthwise as desired by the user. Alternatively, as illustrated with respect to lengthwise segments 12B and 12C, the automatic clamping systems 22 can be fixedly attached to each lengthwise segment at a select lengthwise spacing. The clamping systems described herein allow a fabricator to quickly and easily adhere juxtaposed sheet material stock without having to fumble with multiple clamps. A user need simply align the various embodiments along juxtaposed edges with adhesive therebetween to be secured and the clamps can be readily fastened. The embodiments illustrated in FIGS. 2 and 4 including the automatically clamping system are particularly advantageous because of the speed and uniformity with which pressure can be applied to the juxtaposed edges. The embodiments illustrated in FIGS. 3 and 4 have particular advantages because they can be used to attach curved edges, whether they have inner or outer radii or corners. Including the feature of the clamps being slidable relative to the rigid clamp base allows adjustability that may be advantageous in particular applications. Significantly, all of the illustrated embodiments can be readily manufactured from conventional steel, aluminum or other metal alloy channel or plate stock to minimize cost of the sheet material clamp systems describe herein. Other materials that are sufficiently rigid could be substituted for the metals discussed above. Thus, the many advantages described herein can be provided through inexpensive off-the-shelf commodity materials and easily assembled by workers of limited skill. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Technical Field The present invention is directed toward a sheet material clamp and more particularly toward a sheet material clamp with multiple clamping structures positioned lengthwise along a clamping surface. 2. Background Art It is customary in the building and construction trades to install countertops in various residential and commercial building locations such as kitchens, bathrooms or office workspaces. Relatively simple countertop designs can be fabricated offsite and installed by a finish carpenter as delivered. In the alternative, more highly specialized countertops are often fabricated from sheet materials onsite as part of the installation process. This second onsite method of installation and fabrication is typically used in more highly customized applications such as luxury homes. Custom countertops which are fabricated onsite can be created from laminated wood products, stone or specialized plastic sheet materials. In many installations it is desired to bond a double thickness of the sheet material being used to the front edge of the countertop. The double thickness material along the front edge of a countertop can provide a more durable and aesthetically appealing edge surface toward the living or high use area. In addition, the use of a relatively thin length of material to form the double thickness edge can provide a significant overall savings of material costs. Typically, the two portions of sheet material which are being bound together to form a double thickness edge are affixed to each other with an adhesive specially formulated for the material in use. Clamping pressure must be applied along the front edge of the countertop to assure that the sheet materials being bound are held in close proximity while the adhesive sets. A row of C-clamps along the countertop edge can be used to apply the necessary clamping pressure. However, the use of C-clamps in this application can be difficult since numerous separate clamps must be applied along the countertop edge and it can be difficult to get an even application of pressure along the edge with a series of individual clamps. In addition the installation of individual clamps requires the countertop craftsman to position and tighten multiple clamps quickly as appropriate clamping pressure must be applied before the adhesive begins to set. It is quite possible through the inexpert use of C-clamps to ruin a countertop edge by not applying pressure evenly and quickly enough. In many custom countertops, the countertops have curved edges and the curved edges can vary from inner and outer radii or corners and straight edges. These complicated edge configurations can further enhance the risk of ruining countertop edges by not applying suitable pressure. The present invention is directed toward overcoming one or more of the problems discussed above. | <SOH> SUMMARY OF THE INVENTION <EOH>One aspect of the present invention is a sheet material clamp having a rigid clamp base of a pre-selected length. The length of the clamp base should substantially equal or exceed the length of the countertop edge being clamped. The rigid clamp base has a clamping surface running along its length and at least two clamping apparatus rigidly bonded to the clamping base. The clamping apparatus function by applying clamping pressure through a pressure foot toward the clamping surface. The apparatus for applying clamping pressure are preferably spaced along the length of the clamp base so that clamping pressure will be applied evenly along the edge of the countertop being fabricated. The apparatus for applying clamping pressure can feature a captive C-clamp type design with a female threaded socket formed in a claming frame and a mating male threaded shaft. The male shaft can be attached at one end to the pressure foot and have a handle associated with the other end. In this configuration turning the handle similar to the operation of a C-clamp will drive the pressure foot toward the clamping surface. Alternatively the apparatus for applying clamping pressure can be a fluid driven actuator such as a hydraulic or pneumatic cylinder, or alternatively an electromechanical motor. The actuator can be operatively associated with a shaft connected to the pressure foot so that application of power to the actuator drives the pressure foot toward the clamping surface. In a highly preferred embodiment, the rigid clamp base consists of a number of lengthwise segments joined in series by hinges that enable pivotal movement of the various lengthwise segments relative to one another. The rigid clamp base can be made of a substantially elongate rectangular bar or a channel member having a channel opening sized to receive layered sheet material to be clamped, and either the rectangular bar or the channel member can be divided into lengthwise segments and joined by hinges as described above. The present invention provides a sheet material clamp which can be used to efficiently and quickly apply clamping pressure to two lengthwise portions of sheet material which are being bonded together. In addition, the sheet material clamp is optimized to provide pressure which is evenly distributed along the length of the materials being bonded. Furthermore, the present invention provides a clamp structure that can quickly clamp edges having inner or outer corners or radii. | 20040127 | 20060606 | 20050106 | 67571.0 | 0 | RAMIREZ, RAMON O | SHEET MATERIAL CLAMP | SMALL | 0 | ACCEPTED | 2,004 |
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10,766,613 | ACCEPTED | Method for the use of information in an auxiliary data system in relation to automated testing of graphical user interface based applications | A system and method for using information in an auxiliary data system to enhance the capability of automated testing of graphical user interface (GUI) based applications. Embodiments of the invention establish a method to map auxiliary data to automated tests of the GUI in order to map out all tests that need to be created, which tests need to be changed as this auxiliary data changes, and how each automated test needs to be updated to handle these changes. | 1. A method for managing testing scripts used to test an application, the method comprising: selecting test scripts, wherein each test script corresponds to auxiliary data items; storing data that associates the selected test scripts with their corresponding auxiliary data items; receiving an indication that one of the auxiliary data items has been altered; searching the stored data to identify the test scripts that correspond with the altered one of the auxiliary data items; and generating an indication of the identified test scripts. 2. The method of claim 1, further comprising: recording a user's interaction with the application, thereby generating a test script. 3. The method of claim 2, further comprising: recording default values relied upon by the application during a user's interaction with the application, wherein the default values are included with the test script. 4. The method of claim 1, further comprising: recording auxiliary data corresponding to a user's interaction with the application. 5. The method of claim 4, wherein recording the auxiliary data comprises: querying a database that includes the auxiliary data. 6. The method of claim 4, wherein recording the auxiliary data comprises: querying a auxiliary data file that includes the auxiliary data. 7. The method of claim 4, wherein recording the auxiliary data comprises: calling an API that can return the auxiliary data. 8. The method of claim 4, wherein recording the auxiliary data comprises: querying a Web service that can return the auxiliary data. 9. The method of claim 1, wherein storing data that associates the selected test scripts with their corresponding auxiliary data items further comprises: tagging user interface objects that the user interacts with when operating the application; and mapping the tagged elements with their corresponding auxiliary data items. 10. The method of claim 1, wherein storing data that associates the selected test scripts with their corresponding auxiliary data items comprises: storing a record of each auxiliary data item and the test script with which it is associated. 11. The method of claim 1, wherein storing data that associates the selected test scripts with their corresponding auxiliary data items comprises: storing a record of each test script and the corresponding auxiliary data items. 12. The method of claim 1, further comprising: prompting a user to generate a new test script to test the altered one of the auxiliary data items. 13. The method of claim 1, further comprising: prompting a user to alter a test script to test the altered one of the auxiliary data items. 14. The method of claim 1, further comprising: prompting a user to remove a test script if the objects it tests have been deleted from the auxiliary data items. 15. A method for managing testing scripts used to test an application, the method comprising: selecting user-interface objects, wherein each user-interface object corresponds to auxiliary data items; storing data that associates the selected user-interface objects with their corresponding auxiliary data items; receiving an indication that one of the auxiliary data items has been altered; searching the stored data to identify user-interface objects that correspond with the altered one of the auxiliary data items; and generating an indication of the identified user-interface objects. 16. The method of claim 15, further comprising: prompting a user to generate a new user-interface object to test the altered one of the auxiliary data items. 17. The method of claim 15, further comprising: prompting a user to alter a user-interface object to test the altered one of the auxiliary data items. 18. A system for managing testing scripts used to test an application, the system comprising: a processor; a memory device; a plurality of instructions stored on the memory device, the instruction configured to cause the processor to: select test scripts, wherein each test script corresponding to auxiliary data items; store data that associates the selected test scripts with their corresponding auxiliary data items; process an indication that one of the auxiliary data items has been altered; search the stored data to identify the test scripts that correspond with the altered one of the auxiliary data items; and generate an indication of the identified test scripts. 19. A system for managing testing scripts used to test an application, the system comprising: means for selecting user-interface objects, wherein each user-interface object corresponds to auxiliary data items; means for storing data that associates the selected user-interface objects with their corresponding auxiliary data items; means for receiving an indication that one of the auxiliary data items has been altered; means for searching the stored data to identify user-interface objects that correspond with the altered one of the auxiliary data items; and means for generating an indication of the identified user-interface objects. | PRIORITY The present application claims priority from commonly owned and assigned application No. 60/443,030, entitled A Method for the Use of Information in an Auxiliary Data System in Relation to Automated Testing of Graphical User Interface Based Applications, which is incorporated herein by reference. COPYRIGHT A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights. FIELD OF THE INVENTION The present invention relates generally to tools designed to help with application maintenance through the design, development, and deployment phases. More particularly, but not by way of limitation, the present invention relates to the process of testing application quality through automated user interface (“UI”) testing. BACKGROUND OF THE INVENTION Automated testing is the process of repetitively and iteratively running through common user or use scenarios in an application to effectively test the known features, boundary conditions, expected application responses and underlying software code paths of the application. Technology to automatically replay user actions to simulate interaction with the application removes the requirement of having a human operator to run though the application repeatedly. Automated testing can be performed on many types of software from imbedded systems to web-browser-based applications. Automated testing traditionally captures the actions of a user interacting with the user interface of an application through a recording process. The software monitors and recognizes user actions such as button clicks, mouse movements, entering text, and using navigation keys (such as the commonly used <TAB>, <ALT>, <ESC> keys). These actions are then “replayed” by the automated testing software. And as user interactions are replayed systematically, the automated testing software captures any changes in the way the application responds (such as unexpected graphical representations, inconsistent data returned or changes in workflow) and reports them to the automated test software user as possible defects in the application being tested. To be able to replay a user's interaction with an application over and over again, the automated testing software must keep a script of the user actions. This script describes which actions a user has taken (button clicks, text entries, mouse movements, etc.) as well as the graphical interface objects the user has interacted with. A graphical interface object might be a textbox that accepts text entry, a button that can be clicked, a hyperlink in a web browser that directs the application to a new page, a dropdown list of values, or an application menu command. The script describes both what action was performed by the user and which object the action was performed on. Thus, when the script is “replayed”, the automated testing software can reconstruct the user's actions as closely as possible. Scripts are usually written automatically by the test recorder in a familiar contemporary programming language such as Visual Basic, Java, C++, or JavaScript. This resulting program code is exposed to the user of the automated testing system, providing a programmatic environment that the user of the automated testing system can take advantage of to add additional programmatic logic. It is not uncommon for automated testing software to extend the underlying programming language to incorporate commands to identify and manipulate graphical interface objects as well as mimic user interactions. The recorder uses these language extensions when automatically writing the script code during a recording session. But problems exist with this current approach. To comprehensively test an application, a number of these scripts are created to test common features, functionality, logic paths, and programmatic logic of the application. Because these scripts reference graphical interface objects that existed while the original recording took place, they are very susceptible to changes in the application. That is, if a graphical interface object has changed (been renamed, replaced by a different type, a new object has been added, or workflow has changed), the references to the object in the original script may not work. Additionally, scripts are susceptible to changes in the underlying data structure of the application because they are only written at the user interface level (e.g. what UI objects have been interacted with). If, for example, a UI object receives some data that will be stored in a database, and the definition of the type of data that can be stored in the database changes, the script will have no knowledge of this. This leads to entry of erroneous data in the application and potentially incongruous results during testing. The script may not be wrong at the UI level, but its lack of understanding of the underlying application effectively invalidates its accuracy. The only solution to such a set of problems is to replay all scripts that have been recorded and track down any obvious problems (scripts failing because a UI object that is referenced does not exist anymore) or indirect problems (underlying requirements for data changing). This turns out to be a very time consuming process for the automated test software user. For large software systems, the number of scripts required to comprehensively test an application can be very large. With a very large number of test scripts, maintenance of the tests themselves can be a complex and sizable task. Many times, maintenance of test scripts is the largest component of time involved in implementing automation. Although present devices are functional, they are not sufficiently accurate or otherwise satisfactory. Accordingly, a system and method are needed to address the shortfalls of present technology and to provide other new and innovative features. SUMMARY OF THE INVENTION Exemplary embodiments of the present invention that are shown in the drawings are summarized below. These and other embodiments are more fully described in the Detailed Description section. It is to be understood, however, that there is no intention to limit the invention to the forms described in this Summary of the Invention or in the Detailed Description. One skilled in the art can recognize that there are numerous modifications, equivalents and alternative constructions that fall within the spirit and scope of the invention as expressed in the claims. The present invention can provide a system and method for using information in an auxiliary data system to enhance the capability of automated testing of graphical user interfaces. In one exemplary embodiment, the present invention can: 1) record user actions into a set of scripts; 2) correlate data from the auxiliary data system with graphical objects that have been interacted with; 3) store correlations alongside actual programmatic test scripts; 4) monitor changes to the auxiliary data; and 5) use this auxiliary data mapping (and any changes recognized in the auxiliary data) to facilitate a number of new features in automated testing. BRIEF DESCRIPTION OF THE DRAWINGS Various objects and advantages and a more complete understanding of the present invention are apparent and more readily appreciated by reference to the following Detailed Description and to the appended claims when taken in conjunction with the accompanying Drawings wherein: FIG. 1 is a block diagram of one embodiment of the present invention. FIG. 2 is a screen shot of a UI with the UI elements labeled. FIG. 3 is a screen shot of a UI with the auxiliary data labeled. FIG. 4 illustrates the correlation between the UI elements and the auxiliary data; FIG. 5 illustrates one embodiment of a system constructed according to the principals of the patent invention. DETAILED DESCRIPTION One embodiment of the present invention captures auxiliary data (sometimes called “meta data”) about a user interface, data requirements, and expected functionality of an application in order to advance the way automated tests are planned, created, and maintained. Many times this auxiliary data is an integral part of the tested application's design and may describe how the final application should be rendered in the user interface and what data is acceptable to be input into the system. Generally, most applications use this architecture in one form or another to efficiently abstract data from the display. More particularly, but not by way of limitation, a contemporary class of applications called “packaged applications” use this architecture extensively (by way of example, vendors in this class would include PeopleSoft, SAP, Siebel, Oracle, JD Edwards, Lawson, and 12). Auxiliary data can be captured through any reference mechanism such as a database, flat files, API, shared memory segment, or web service as long as the underlying application stores such information. One embodiment of the present invention correlates this auxiliary data with the final graphical interface objects, application properties, functionality, data requirements, and/or workflow. This embodiment then determines which recorded automated test scripts reference the elements, data, or functionality described by the auxiliary data. And, by examining the auxiliary data and also watching for any changes in this auxiliary data set, this embodiment of the invention can determine which automated tests need to be created, updated, removed or otherwise changed. Referring now to the drawings, where like or similar elements are designated with identical reference numerals throughout the several views, and referring in particular to FIG. 1, it is a flow chart of one embodiment of the present invention. This embodiment includes four parts: (1) the recording of a test script against the user interface (Block 50), (2) the correlation of user interface objects to underlying auxiliary data (Block 52), (3) the monitoring of change in underlying auxiliary data (Block 54), and (4) the application of these changes to automated testing (Block 56). Other embodiments do not include all four steps and yet other embodiments add additional steps. Each of these actions is described in greater detail below. Recording a Test Script Against The User Interface As previously described, an automated test of a graphical user interface can be represented by a script. In general terms, this script can be a manual set of actions (testing can be performed repetitively by a human user as well) or a script designed to be replayed by a piece of automation software. An automation test script is an interpretable piece of code that can be replayed by software equipped to interpret and execute this code. This script can be coded in a number of formats or languages but is usually stored in a common contemporary programming language such a Visual Basic, Java, or C++. Regardless of language format, there is usually the capability in the script's language to reference UI elements, recreate user actions, and manage application test workflow in a way that the original recording can be replayed programmatically. Test scripts are usually stored as files on a disk or saved in a central repository for team development. Some embodiments of the present invention use common techniques to record, write test scripts, and replay user actions with an application. These techniques work with traditional desktop applications as well as applications derived through web browsers or other common application presentation tools. Correlation of User Interface Objects to Underlying Auxiliary Data Many applications (including ERP systems, CRM systems, and Web-based systems) contain auxiliary data about the way the application works. This descriptive data may include (but is not limited to): Multiple different definitions of the UI structure (such as the name, type, and location of all user interface objects to be presented in the application). A definition of where data presented in the interface is retrieved from (such as a list of information retrieved from a specific database record). A description of workflow in the application (the multiple steps at the graphical layer a user would need to take to complete a “process” in the application). Descriptions of aesthetic or programmatic customizations made to the application. Descriptions of external APIs or systems connected into the application. Descriptions of versions of the application, interface, configurations, or application data This information is commonly stored in several formats, including database systems, file systems, application protocol interface captures, Web services, etc. Four of these systems are described below. Database Systems In many large systems much of the data (both application data as well as auxiliary data about the application itself) is stored in an underlying database. The invention uses all auxiliary data in the database that describes the functionality, aesthetic, configuration or workflow of the system. TABLE 1 Example Database Tables with Relevant Auxiliary Data Table - PANEL_WORKFLOW PANEL_ID ELEMENT NEXT_PANEL_ID 1 OK_BUTTON 2 1 HELP_BUTTON 3 2 HELP_BUTTON 3 Table - PANEL_EVENTS PANEL_ID ELEMENT EVENT_TYP EVENT_CODE 1 NONE PANEL_LOAD (code segment . . . ) 1 OK_BUTTON CHECK_VALUES (code segment . . . ) Table - PANEL_ELEMENTS ELEMENT— DB— PANEL_ID ELEMENT TYPE DB_TABLE COLUMN 1 EMP— TEXT_BOX EMPLOYEE FIRST— NAME NAME 1 EMP_DEPT DROP_DOWN ORG— DEPART- STRUCT MENTS File Systems In replacement of (or in addition to) a database system, many applications contain auxiliary application data in a set of additional files. These files can be formatted in many ways. The files may be used in the process of creating or displaying the user interface or may define report parameters that the application uses to display information to the user. These parameters can be important information about the final displayed result to the user through the application or even tie directly back into which elements in a database to report on. TABLE 2 Example File Referencing Database Elements // Report parameters for customer relationship application report name = example report report time period = last seven days report x-axis = DATABASE.CUSTOMER_ACCOUNT report y-axis = DATABASE.BILLING_PER_DAY Application Programming Interfaces (API) Many times, auxiliary data about a system can be captured by querying the application through a known programming interface. The information returned can be similar to the data from a direct database query of a data file. Web Services Similar to an application programming interface, some applications supply web-based services that when queried will return similar information about the application such as a database, data file, or API. In many applications, this underlying auxiliary data is the source for the final UI display. The auxiliary data may describe the layout of the screen, the types of UI elements (textboxes, dropdown lists), where data entered into the application will reside in the underlying data system, data processing code, and underlying workflow of the application as a user navigates from screen to screen. In the UI generation process, the underlying application generally tags elements in the user interface in such a way that data returned from the UI to application can be recognized. Thus, each user interface element can be identified by its tag and this tag can be mapped back to the underlying auxiliary data representation. The invention captures these mappings and integrates them with the recording process. When a user is navigating an application, each UI element interacted with is recognized both at the UI level (e.g., how to identify the object through the interface API) as well as the underlying auxiliary data that generated the UI element. Just as a script is generated that references the user interface objects, a repository of auxiliary data mappings can be created as well. For example purposes, Table 3 sets forth a generic test script to enter data into the dialogue box and submit it to the application. The response from the application (in another dialogue box or screen that would appear) would appear in the elements at the bottom of the dialogue. These results would be checked against expected results. TABLE 3 Example Script for Automated Test // identify the dialogue box and open it DialogueBox(“Requisition Items”).Open( ) DialogueBox(“Requisition Items”).Tab(“Requisition Form”).Select( ) // select a value from the drop down box DialogueBox(“Requisition Items”).DropDown(“Requester”).Select(“Susan Miller”) // check the results on the returned screen resultID = DialogueBox(“Requisition Items”).TextBox(“Item ID”).GetValue( ) resultRQ = DialogueBox(“Requisition Items”).TextBox(“Requisition Quantity”).GetValue( ) If resultID != 999 then Print(“Error with Item ID”) If resultRQ !=999 then Print(“Error with Requisition Quantity”) The resulting script identifies the UI elements on the screen and writes them into the test script. FIG. 2 illustrates an example. The scripts for the UI elements are represented by references number 58. At the same time the script generates the UI specific identifiers, the invention also keeps track of the underlying auxiliary data that generated the UI elements as well as all of their properties. FIG. 3 illustrates the auxiliary data at reference number 60. Each underlying auxiliary data source has a number of properties associated with it which will depend on the type of source data. For example, the COMPONENT may describe a set of pages in a logical workflow in the application. The valid properties for a COMPONENT may be a list (and order) of all PAGES in the workflow. A PAGE may describe all the UI elements that appear on it as well as any custom code that manages data manipulation such as sorting or formatting. A UI ELEMENT would describe the object type (textbox, dropdown, tab, button, etc.) as well as the destination database table for entered data and this database field's type and length. The auxiliary data types of their specific properties may be custom to each application. As users interact with UI objects, their underlying auxiliary data tags are discovered and the auxiliary data that generated them are stored in an additional file along with the script. The invention uses the XML data format to allow flexibility in which auxiliary data types are present, their individual properties, and the current value of each of their properties. <DEFINE PS_REQUEST_PANEL> <TYPE> COMPONENT </TYPE> <SOURCE> DATABASE:PS_HRMS8.8 </SOURCE> <PAGE> PS_REQUEST_PANEL_START </PAGE> <PAGE> PS_REQUEST_PANEL_DETAILS </PAGE> <VERSION> 1.3.2 </VERSION> <LAST-MODIFICATION> 01/24/04 11:22:33 </LAST- MODIFICATION> </DEFINE> <DEFINE PS_REQUEST_PANEL_START> <TYPE> PAGE </TYPE> <SOURCE> DATABASE:PS_HRMS8.8 </SOURCE> <UI_ELEMENT> PS_TEXTBOX_REQUESTER </PAGE> <VERSION> 1.3.1 </VERSION> <LAST-MODIFICATION> 01/24/04 11:01:33 </LAST- MODIFICATION> </DEFINE> <DEFINE PS_TEXTBOX_REQUESTER> <TYPE> UI ELEMENT </TYPE> <SOURCE> DATABASE:PS_HRMS8.8: PS— REQUESTER_TABLE: REQUESTER_NAME </SOURCE> <DB_TYPE> CHAR </TEXT> <DB_LENGTH> 256 </DB_LENGTH> <LAST-MODIFICATION> 01/24/04 09:01:33 </LAST- MODIFICATION> </DEFINE> After the recorder generates the script to reference the UI object and the invention captures the current information about the underlying auxiliary data, the two items can effectively be correlated together. FIG. 4 illustrates this correlation. It should be noted that embodiments of the invention include the ability to capture both explicit UI objects being interacted with (e.g., objects where text is entered or buttons being clicked) as well as implicit objects such as the environment of the page or UI elements that are not interacted with but provide default values. This is important because a test script can rely on UI element default settings to work properly even if the element has not been directly interacted with. In the example shown, even if the “Status” dropdown is not manipulated by the user during recording, it is implied that the value “Open” is selected. The need to record the auxiliary data value for this UI element is the same as if the user has selected the dropdown in the UI and picked the “Open” entry explicitly. Monitoring Change in Underlying Auxiliary Data Once the auxiliary data mapping files have been created, the invention can find changes in the underlying auxiliary data that may affect the functionality of a test script. If the auxiliary data that generates a user interface element has changed, the script may not work any longer if the UI reference has become invalid because of this change. By comparing the values in the auxiliary data mapping file to existing values in the auxiliary data system containing current auxiliary data information (e.g., a database) a list of all changes can be made. Once the list of changes is identified, the invention can organize changes into categories that describe how the test script might be affected. For example, if an auxiliary data representation of a PAGE has a number of UI_ELEMENTS removed from it, a test script that references those removed objects will not function properly. Additionally, if the auxiliary data representation of a dropdown box has a new default value, a test script which depends on this default value may enter erroneous information into the application. Embodiments of the invention categorize the changes, correlates them back to the test script that has been written and lets the user of the automated testing software decide how to update their test scripts to comply with any changes that have been made in the auxiliary data. Once the objects are defined and equated, a complete list of objects from the auxiliary data system can be created. This list of objects is called the object repository (OR). This OR is used as the baseline and reference version. Once this baseline reference version is created, a continual scan is set up of the objects in the auxiliary data source. As objects change, they are recorded as new versions in the OR. Each time a change is made to an object, the associated test scripts are flagged for change. With the change information from the OR, three types of actions on the test script set can be managed: adding new scripts, maintaining existing scripts, removing existing scripts. Application of Changes to Automated Testing A number of uses for the invention are listed below to illustrate how the technical solution manifests itself into automated test software. Typical uses involve test planning and maintenance, both of which are described below. Use of the Invention for Test Planning Before ever recording a test script, the auxiliary data source can be queried for all auxiliary data types of interest. This could include screens, pages, UI elements, etc. This catalogue of all objects can be used to create a skeleton test plan for the automated testing user. Using this test plan, the user can record test scripts to ensure that every relevant auxiliary data source object has a test written against it. This provides a simple coverage mechanism for the user to understand exactly what test scripts need to be recorded to fully test the underlying application which will be generated from its auxiliary data. TABLE 4 Example Test Plan Outline Generated From Auxiliary Data DATABASE:Human Resources:COMPONENT: Employee:PAGE: Test New Smoke DATABASE:Human Resources:COMPONENT: Employee:CODE: Code:Panel Load New Event DATABASE:Human Resources:COMPONENT: Employee:CODE: Code:Verify Data New Event DATABASE:Human Resources:COMPONENT: Employee: New BUTTON: Submit Form Use of the Invention for Test Maintenance As a set of tests (scripts in our example) are created to cover all the functionality of a software application the need to maintain and update the scripts increases. There are three main ways the script base is maintained: 1) New scripts are added to the script set to cover new functionality. 2) Existing scripts are updated to reflect changes in the UI elements tested, the data entered or examined, or workflow of the application. Scripts are removed when the functionality or elements they are testing become obsolete. Add New Scripts to Cover New Functionality As the auxiliary data changes show new objects in the system (components, page, and individual UI elements) the automated test user can be prompted to create a new test for the new object. Modify Existing Scripts As changes are identified in the auxiliary data, all scripts that are equated to those objects will be flagged. The automated test software user can choose to update the test script based on the type of change to the object. Also, new objects may appear on a UI. These changes will be flagged for the testing user as well as in case they are interested in adding them to the test script. Removal of Scripts Many times, objects are removed from the system. Using the OR, all objects that are removed are tied to test scripts as well. If an object is removed, the related test script can be augmented or removed altogether. FIG. 5 illustrates one system constructed according to the present invention. This embodiment includes an application server 62 connected through a network 64 to a user 66 and a testing server 68. These devices can be of any computer architecture. Additionally, the devices can be integrated in some embodiments. In conclusion, the present invention provides, among other things, a system and method for using information in an auxiliary data system to enhance the capability of automated testing of graphical user interface (GUI) based applications. Those skilled in the art can readily recognize that numerous variations and substitutions may be made in the invention, its use and its configuration to achieve substantially the same results as achieved by the embodiments described herein. Accordingly, there is no intention to limit the invention to the disclosed exemplary forms. Many variations, modifications and alternative constructions fall within the scope and spirit of the disclosed invention as expressed in the claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Automated testing is the process of repetitively and iteratively running through common user or use scenarios in an application to effectively test the known features, boundary conditions, expected application responses and underlying software code paths of the application. Technology to automatically replay user actions to simulate interaction with the application removes the requirement of having a human operator to run though the application repeatedly. Automated testing can be performed on many types of software from imbedded systems to web-browser-based applications. Automated testing traditionally captures the actions of a user interacting with the user interface of an application through a recording process. The software monitors and recognizes user actions such as button clicks, mouse movements, entering text, and using navigation keys (such as the commonly used <TAB>, <ALT>, <ESC> keys). These actions are then “replayed” by the automated testing software. And as user interactions are replayed systematically, the automated testing software captures any changes in the way the application responds (such as unexpected graphical representations, inconsistent data returned or changes in workflow) and reports them to the automated test software user as possible defects in the application being tested. To be able to replay a user's interaction with an application over and over again, the automated testing software must keep a script of the user actions. This script describes which actions a user has taken (button clicks, text entries, mouse movements, etc.) as well as the graphical interface objects the user has interacted with. A graphical interface object might be a textbox that accepts text entry, a button that can be clicked, a hyperlink in a web browser that directs the application to a new page, a dropdown list of values, or an application menu command. The script describes both what action was performed by the user and which object the action was performed on. Thus, when the script is “replayed”, the automated testing software can reconstruct the user's actions as closely as possible. Scripts are usually written automatically by the test recorder in a familiar contemporary programming language such as Visual Basic, Java, C++, or JavaScript. This resulting program code is exposed to the user of the automated testing system, providing a programmatic environment that the user of the automated testing system can take advantage of to add additional programmatic logic. It is not uncommon for automated testing software to extend the underlying programming language to incorporate commands to identify and manipulate graphical interface objects as well as mimic user interactions. The recorder uses these language extensions when automatically writing the script code during a recording session. But problems exist with this current approach. To comprehensively test an application, a number of these scripts are created to test common features, functionality, logic paths, and programmatic logic of the application. Because these scripts reference graphical interface objects that existed while the original recording took place, they are very susceptible to changes in the application. That is, if a graphical interface object has changed (been renamed, replaced by a different type, a new object has been added, or workflow has changed), the references to the object in the original script may not work. Additionally, scripts are susceptible to changes in the underlying data structure of the application because they are only written at the user interface level (e.g. what UI objects have been interacted with). If, for example, a UI object receives some data that will be stored in a database, and the definition of the type of data that can be stored in the database changes, the script will have no knowledge of this. This leads to entry of erroneous data in the application and potentially incongruous results during testing. The script may not be wrong at the UI level, but its lack of understanding of the underlying application effectively invalidates its accuracy. The only solution to such a set of problems is to replay all scripts that have been recorded and track down any obvious problems (scripts failing because a UI object that is referenced does not exist anymore) or indirect problems (underlying requirements for data changing). This turns out to be a very time consuming process for the automated test software user. For large software systems, the number of scripts required to comprehensively test an application can be very large. With a very large number of test scripts, maintenance of the tests themselves can be a complex and sizable task. Many times, maintenance of test scripts is the largest component of time involved in implementing automation. Although present devices are functional, they are not sufficiently accurate or otherwise satisfactory. Accordingly, a system and method are needed to address the shortfalls of present technology and to provide other new and innovative features. | <SOH> SUMMARY OF THE INVENTION <EOH>Exemplary embodiments of the present invention that are shown in the drawings are summarized below. These and other embodiments are more fully described in the Detailed Description section. It is to be understood, however, that there is no intention to limit the invention to the forms described in this Summary of the Invention or in the Detailed Description. One skilled in the art can recognize that there are numerous modifications, equivalents and alternative constructions that fall within the spirit and scope of the invention as expressed in the claims. The present invention can provide a system and method for using information in an auxiliary data system to enhance the capability of automated testing of graphical user interfaces. In one exemplary embodiment, the present invention can: 1) record user actions into a set of scripts; 2) correlate data from the auxiliary data system with graphical objects that have been interacted with; 3) store correlations alongside actual programmatic test scripts; 4) monitor changes to the auxiliary data; and 5) use this auxiliary data mapping (and any changes recognized in the auxiliary data) to facilitate a number of new features in automated testing. | 20040128 | 20080902 | 20050127 | 97774.0 | 0 | VU, TUAN A | METHOD FOR THE USE OF INFORMATION IN AN AUXILIARY DATA SYSTEM IN RELATION TO AUTOMATED TESTING OF GRAPHICAL USER INTERFACE BASED APPLICATIONS | SMALL | 0 | ACCEPTED | 2,004 |
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10,767,131 | ACCEPTED | Tablecloth covering and method of covering and skirting a table | The invention relates to fitted tablecloth coverings that may be affixed to a table without the use of a tool or affixing devices. The object of the present invention is to provide a tablecloth that may conveniently and quickly be affixed to a table and to provide an appealing visual presentation that does not require the use of installation tools and that will not damage the table. | 1. A table cover for covering a tabletop, said table cover comprising: a top cover for covering a top surface of a tabletop, the top cover having a generally polygonal contour with a plurality of sides at its outer periphery thereof; and a plurality of side drops, each extending outwards from the respective one of the sides of the top cover, each of two adjacent ones of the side drops defining an adjoining corner with a first drop fold area and a second drop fold area configured to fold for binding the respective adjoining corner of the side drops with an adjacent side drop of the plurality of side drops. 2. The table cover of claim 1, wherein the first and second drop fold areas are symmetrical to each other. 3. The table cover of claim 2, wherein the first and second drop fold areas each has a generally triangular shape. 4. The table cover of claim 1, wherein the first and second drop fold areas are configured to fold and bind by binding agents. 5. The table cover of claim 1, wherein the first and second drop fold areas are configured to fold and bind by sewing or application of heat. 6. The table cover of claim 1, wherein the table cover is for using as a trade show tablecloth. 7. The table cover of claim 1, wherein the table cover is formed of a resilient material. 8. The table cover of claim 7, wherein the table cover is formed of vinyl. 9. The table cover of claim 7, wherein the top cover has a dimension shorter than that of the tabletop, and is applicable to cover the tabletop by stretching. 10. The table cover of claim 9, wherein each of the side drops has a width larger than the thickness of the tabletop. 11. The table cover of claim 1 further including a plurality of identifications to identify boundaries of between the top cover and adjacent side drops, and of between the first and second drop fold areas. 12. The table cover of claim 11, wherein the boundary identifications are pressed or embedded lines. 13. A table cover for covering a tabletop, said table cover comprising: a top cover for covering a top surface of a tabletop, the top cover formed of a resilient material and sized a little smaller than the top surface of the tabletop the top cover including a plurality of sides at its outer periphery thereof; and a plurality of side drops formed of a resilient material, each of the side drops extending outwards from the respective one of the sides of the top cover, each of two adjacent ones of the side drops defining an adjoining corner, each of the adjoining corners being folded and bound respectively to an adjacent side drop of the plurality of side drops. 14. A covered table comprising: a tabletop covered with a resilient table cover, the table cover having a top cover and a plurality of side drop portions extending from the top cover, each of two adjacent side drop portions defining an adjoining corner area there-between, the adjoining corner areas each being folded and bound to at least one of two adjacent side drop portions of the table cover, thereby forming a plurality of fitted corners of the table cover. 15. The table of claim 14 further including a skirt attached around the sides of the tabletop on top of the fitted sides of the table cover. 16. The table of claim 15, wherein the skirt is formed of fabric. 17. The table of claim 16, wherein the skirt is attached to the sides of the tabletop by a plurality of staples, tacks, or pins. 18. The table of claim 17, wherein the fabric skirt includes a reinforced band portion at an upper area thereof, and the skirt is attached to the tabletop by a plurality of staples, tacks, or pins applied at the reinforced band portion. 19. The table of claim 15, wherein the table is usable for a trade show. 20. A method of making a table cover for covering a tabletop, comprising: providing a table cover formed of a resilient material and having a top cover and a plurality of side drop portions, the top cover being sized a little smaller than the top surface of the tabletop, the side drop portions including a plurality of adjoining corner areas between two adjacent side drop portions, each of the corner area including a first drop fold area and a second drop fold area; folding each of the adjoining corner areas about the first and second drop fold areas; and binding each of the folded adjoining corner areas with adjacent side drop portions of the table cover so as to make the side drop portions drawn in a generally vertical direction when the table cover is placed over the tabletop. 21. The method of claim 20 further comprising the step of applying binding agents about the first and second drop fold areas of the adjoining corner areas for the binding of the folded adjoining corner areas with adjacent side drop portions. 22. The method of claim 20, wherein the binding of the folded adjoining corner areas with adjacent side drop portions is performed by sewing or application of heat. 23. A method of placing a table cover over a tabletop, comprising: providing a table cover formed of a resilient material and having a top cover and a plurality of side drop portions, the top cover being sized a little smaller than the top surface of the tabletop, the side drop portions including an adjoining corner area between two adjacent side drop portions, each of the corner area including a first drop fold area and a second drop fold area, the adjoining corner area being folded and bound to at least one of the two adjacent side drop portions of the table cover, thereby forming a plurality of fitted corners of the table cover; locking at least two of the fitted corners of the table cover onto corresponding corners of the tabletop; pulling and stretching the table cover across over opposite corners of the tabletop; and locking the rest of the fitted corners of the table cover onto corresponding corners of the tabletop. 24. A method of applying table coverings and skirts onto a table, the table having a tabletop, the method comprising: providing a table cover formed of a resilient material and having a top cover and a plurality of side drop portions, the top cover being sized a little smaller than the top surface of the tabletop, the side drop portions including an adjoining corner area between two adjacent side drop portions, each of the corner area including a first drop fold area and a second drop fold area, the adjoining corner area being folded and bound to at least one of the two adjacent side drop portions of the table cover, thereby forming a plurality of fitted corners of the table cover; locking at least two of the fitted corners of the table cover onto corresponding corners of the tabletop; pulling and stretching the table cover across over opposite corners of the tabletop; locking the rest of the fitted corners of the table cover onto corresponding corners of the tabletop; providing a skirt formed of a fabric material and dimensioned to cover side areas of the table; and attaching the skirt around the tabletop on top of the fitted sides of the table cover. 25. The method of claim 24, further comprising the step of pulling and smoothing the tablecloth cover across the surface thereof for removing wrinkles during the attaching of the skirt. 26. The method of claim 24, wherein the attaching of the skirt is performed by applying a plurality of fasteners along the sides of the tabletop. 27. The method of claim 26 further comprising the disassembling steps of: pulling the fabric skirt, and thereby detaching the fabric skirt and the plurality of fasteners attached to the fabric skirt; and peeling the fitted table cover off from the tabletop. 28. The method of claim 27 further comprising the step of reusing the removed table cover to a tabletop. | RELATED APPLICATIONS This patent application claims the benefit of, under Title 35, United States Code, Section 119(e), U.S. Provisional Patent Application No. 60/532,121, filed Dec. 23, 2003. FIELD OF THE INVENTION The invention relates to the field of tablecloth coverings and more particularly, to fitted tablecloth coverings that may be affixed to a table, and a method of covering and skirting a table. BACKGROUND OF THE INVENTION Tables used in for instance, trade shows have been utilized for many years. The tables typically have several standard sizes. The visual appeal of the presentation is closely related to the success of the product being advertised. However, these tables are typically used many times over leading to wear and tear. Therefore, these tables used for trade shows generally require a covering to be placed over the top surface and partially down the side of the table in order to dress up the table and to better present the product being advertised. Referring to FIGS. 1 and 2, the current industry way of topping trade show tables 10 is utilizing a white vinyl material 12 that comes on, for instance, rolls 14, that is then cut by hand using scissors 16 to fit the approximate size of the table and then is stapled to the side of the table 10 using an industrial staple gun 18. A fabric skirt is then attached to the edge of the table, also by stapling. This approach has many drawbacks. For instance, because the material 12 comes on a roll 14 and is manually cut to size, it is generally cut much larger than needed and sometimes under cut, therefore creating wasted material. Another problem is that current installation of the vinyl to the tabletop is to staple the material 12 directly to the sides of the table 10. The staples 20 damage the wood upon insertion and when the vinyl 12 is removed after the show; it is torn off leaving the staples 20 in the table. This greatly reduces the life span of the table as well as many wasted man hours removing the staples 20 by hand using a staple removal tool 22 (see FIG. 3). Still another problem is that as the staples 20 accumulate on the side of the table 10, it becomes increasing difficult to install the vinyl top and skirting. Also, as the tables 10 are removed as well as brought to the events they are placed on table dollies (not shown). During this procedure it is very common for equipment handlers to become injured from protruding staples. In addition, during such events, exhibitors themselves and attendees can become injured as well as clothing and trade show materials can become damaged from protruding un-removed staples. Finally, the current installation procedure is time consuming with the vinyl material 12 coming on 50 pound rolls 14 making it cumbersome to handle. SUMMARY OF THE INVENTION What is desired then is an apparatus and method that will address the aforementioned problems. Accordingly, it is an object of the present invention to provide a tablecloth that may conveniently and quickly be affixed to a table and to provide an appealing visual presentation. This and other objects of the invention are achieved by providing a tablecloth that is pre-sized according to standard table dimensions. Some of the benefits to use of the present invention include for instance, there is no wasted material because the tablecloth is pre-cut to the correct size. In addition, the installation and removal of the tablecloth take very little time and pre-made tablecloths allow for a more exact piece count when, for instance, shipping to a show site. According to one aspect of the present invention, a table cover for covering a tabletop, comprises: a top cover for covering a top surface of a tabletop, the top cover having a generally polygonal contour with a plurality of sides at its outer periphery thereof; and, a plurality of side drops, each extending outwards from the respective one of the sides of the top cover, each of two adjacent ones of the side drops defining an adjoining corner with a first drop fold area and a second drop fold area configured to fold for binding the respective adjoining corner of the side drops with an adjacent side drop of the plurality of side drops. The first and second drop fold areas are preferably symmetrical to each other, configured to fold and bind by binding agents, sewing, application of heat, or other known binding methods. The table cover is useful, in particular, as a trade show tablecloth. The table cover is preferably formed of a resilient material such as vinyl, and the top cover can be made to a dimension a little shorter than that of the tabletop and is applicable to cover the tabletop by stretching it. According to another aspect of the present invention, a table cover for covering a tabletop, comprises: a top cover for covering a top surface of a tabletop, the top cover formed of a resilient material and sized a little smaller than the top surface of the tabletop, the top cover including a plurality of sides at its outer periphery thereof; and, a plurality of side drops formed of a resilient material, each of the side drops extending outwards from the respective one of the sides of the top cover, each of two adjacent ones of the side drops defining an adjoining corner, each of the adjoining corners being folded and bound respectively to an adjacent side drop of the plurality of side drops. According to another aspect of the present invention, a covered table comprises a tabletop covered with a resilient table cover, the table cover having a top cover and a plurality of side drop portions extending from the top cover, each of two adjacent side drop portions defining an adjoining corner area there-between, the adjoining corner areas each being folded and bound to at least one of two adjacent side drop portions of the table cover, thereby forming a plurality of fitted corners of the table cover. The covered table preferably includes a skirt attached around the sides of the tabletop on top of the fitted sides of the table cover. The skirt can be formed of a fabric material and attached to the tabletop by applying a plurality of staples, tacks, or pins. According to another aspect of the present invention, a method of making a table cover for covering a tabletop, comprises: providing a table cover formed of a resilient material and having a top cover and a plurality of side drop portions, the top cover being sized a little smaller than the top surface of the tabletop, the side drop portions including a plurality of adjoining corner areas between two adjacent side drop portions, each of the corner area including a first drop fold area and a second drop fold area; folding each of the adjoining corner areas about the first and second drop fold areas; and, binding each of the folded adjoining corner areas with adjacent side drop portions of the table cover so as to make the side drop portions drawn in a generally vertical direction when the table cover is placed over the tabletop. According to still another aspect of the present invention, a method of placing a table cover over a tabletop, comprising: providing a table cover formed of a resilient material and having a top cover and a plurality of side drop portions, the top cover being sized a little smaller than the top surface of the tabletop, the side drop portions including an adjoining corner area between two adjacent side drop portions, each of the corner area including a first drop fold area and a second drop fold area, the adjoining corner area being folded and bound to at least one of the two adjacent side drop portions of the table cover, thereby forming a plurality of fitted corners of the table cover; locking at least two of the fitted corners of the table cover onto corresponding corners of the tabletop; pulling and stretching the table cover across over opposite corners of the tabletop; and, locking the rest of the fitted corners of the table cover onto corresponding corners of the tabletop. According to a further aspect of the present invention, a method of applying table coverings onto a table, the table having a tabletop, the method comprises: providing a table cover formed of a resilient material and having a top cover and a plurality of side drop portions, the top cover being sized a little smaller than the top surface of the tabletop, the side drop portions including an adjoining corner area between two adjacent side drop portions, each of the corner area including a first drop fold area and a second drop fold area, the adjoining corner area being folded and bound to at least one of the two adjacent side drop portions of the table cover, thereby forming a plurality of fitted corners of the table cover; locking at least two of the fitted corners of the table cover onto corresponding corners of the tabletop; pulling and stretching the table cover across over opposite corners of the tabletop; locking the rest of the fitted corners of the table cover onto corresponding corners of the tabletop; providing a skirt formed of a fabric material and dimensioned to cover side areas of the table; and, attaching the skirt around the tabletop on top of the fitted sides of the table cover. The invention and its particular features and advantages will become more apparent form the following detailed description considered with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates installation of a tablecloth covering according to a method known in the prior art; FIG. 2 illustrates installation of the tablecloth covering of FIG. 1, showing the tablecloth being stapled to the side of the table; FIG. 3 illustrates removal of the staples according to the prior art; FIG. 4A is an illustration of one preferred embodiment of the present invention showing the tablecloth being initially applied to one end of the table; FIG. 4B is an illustration of one preferred embodiment of the present invention according to FIG. 4A, showing the tablecloth being drawn across to the table; FIG. 4C is an illustration of one preferred embodiment of the present invention according to FIG. 4A, showing the tablecloth being applied over an opposite end of the table; FIG. 4D is an illustration of one preferred embodiment of the present invention according to FIG. 4A, showing the tablecloth applied to the table; FIG. 5 is a perspective view of a typical table top showing dimensions of surfaces to be covered by the tablecloth; FIG. 6 is a partial top view of one preferred embodiment of the present invention; FIG. 7 is a partial bottom view of one preferred embodiment of the present invention according to FIG. 6; FIG. 8 is a partial top view of the tablecloth according to FIG. 6 showing a folding of a corner; FIG. 9 is a partial bottom view of the tablecloth according to FIG. 8; FIG. 10 is a partial bottom view of the tablecloth according to FIG. 9 illustrating a further fold of the corner for binding onto an inside drop of the tablecloth; and FIG. 11 is a perspective view of one preferred embodiment of the present invention, illustrating application of a skirt along the sides of the tabletop on top of the covered tablecloth. DETAILED DESCRIPTION OF THE DRAWINGS In one preferred embodiment of the present invention, a custom fitted, slip over tablecloth is provided that installs onto, for example, trade show tables with a non-intrusive application. With reference to FIG. 6, a tablecloth 50 includes a top cover “A” for covering the top surface of a tabletop 60 (FIGS. 4-5), and a plurality of (e.g., four) side drop portions “B” extending outwards from the top cover “A”. The tablecloth material is precut to size to accommodate the existing size tables that are offered, or any other size tables for applying thereon. Existing size tables are typically 24″×48″, 24″×72″ and 24″×96″ and having a 2½″ drop on all sides. In a trade show, for example, the site may accommodate many tables of different dimensions. For applying the tablecloths of the invention to these tables, the exact number of the tablecloths 50 can be cut to the corresponding sizes and shipped to the show site. As such, many tablecloths 50 can be cut in advance to cover the existing tables of one or many different dimensions. FIG. 5 illustrates a typical dimension of a conventional six foot table. The present invention, however, is not intended to be limited to any particular sizes and configurations of such tabletops. For example, the tablecloth of the invention is also applicable to any custom made tabletops with a wide variety of different sizes. It is also applicable to a tabletop having a rectangular, hexagonal, or other polygonal configuration. Tablecloths 50 is preferably formed of a thin resilient material such as a thin vinyl. For example, thin (e.g., about 4 mm thick) taffeta can be used for the material. Various polymers, or resilient fabric materials may also be used. However, tablecloth 50 can be formed of a substantially non-resilient material. Tablecloth 50 may be transparent, white, colored, or include suitable decorations or pictures thereon. The top cover “A” of the tablecloth 50 is sized a little shorter than the actual dimension of the tabletop 60 so the resilient material may be stretched to fit tightly onto the tabletop 60. The side drops “B” of the tablecloth 50 is preferably a little wider than the drop size of the table 60 to sufficiently cover thereover. For example, in order to apply onto the conventional size tabletops with two and a half inch drops (see FIG. 5), thin vinyl material is cut into a rectangular shaped table cover 50 with the central top-cover portion “A” dimensioned about one (1) or one half (½) inch shorter than the size of the tabletop and the side drops 52 dimensioned to be about three inch wide. Typical dimensions of the top-cover portion “A” are as follows (when using 4 mm-thick taffeta): For four-foot (48″) tabletop: 47.5″ long; For six-foot (72″) tabletop: 71.5″ long; For eight-foot (96″) tabletop: 95″ long; and Where, the width of the top-cover portion “A” is made to be the same as that of the tabletop (i.e., 24″). Alternatively, if the tablecloth 50 is formed of a substantially non-resilient material as discussed above, the top cover “A” of the tablecloth is sized to be the same or a little bigger than the actual dimension of the tabletop to slip onto the tabletop. Then, the fitted tablecloth formed in accordance with the description below, may include an elasticized portion particularly along the end sides of the tablecloth to secure the formed tablecloth onto the tabletop. For example, elastic materials such as rubber strings may be attached along the edges of the tablecloth resembling conventional bed sheets. According to one preferred embodiment of the present invention as described herein below, four corners of the tablecloth 50 are now suitably folded and then bound with respective adjacent side drops 52 of the tablecloth 50 in order to provide a custom “fitted” cover applicable over the tabletop 60. With reference to FIG. 6 which shows the tablecloth from outside of the tablecloth, the side drops “B” of the tablecloth 50 are first folded backwards along lines “P”. Then, each corner area 54 defined by the folding is now inversely folded along line “Q” as shown in FIG. 8. This forms a first drop fold area “C” and a second drop fold area “D” at the corner area 54, each in a triangular shape facing one another. Then, the first and second drop fold areas C and D are bound to each other by a conventional binding method. Typically, binding agents are applied on the areas C and D for the connection thereof. However, other binding methods can also be applied, for example, such as vinyl welding, riveting, sewing, gluing, elastic or hot knifed or sonic welding, heat formed connection, and Velcro-type connection, etc. After binding of the areas C and D, binding agents are similarly applied to an opposite side of the corner area 54, i.e., on the left inside drop fold area F (shown FIGS. 7 and 8). Then, the combined corner 54 is folded toward a direction 56, and the drop fold area F is bound to the inside drop E as shown in FIG. 10. Alternately, the corner 54 can be folded in an opposite direction (i.e., inversely to the direction 56) and bound onto the other side of drop E, with binding agents previously applied there-about. The above-described folding and binding is repeated on all four sides. To facilitate the folding of the corners, boundary identification lines “P” and “Q” can be printed in advance on the tablecloth 50, preferably with ink or in pressed or embedded lines. Finished exterior corners illustrate only the areas A and B as finished corners when seen from the outside. This finished process creates a monolithic table covering for fitting over a tabletop. The following are letter keys for use in reference with FIGS. 6-10: For 3″ Drop fold— A: Top cover=24″×48″/72″196″ B: Outside drop C: Outside drop fold/left D: Outside drop fold/right E: Inside drop F: Inside drop fold/left G: Inside drop fold/right Where, C is fused to D; and F is fused to E. In accordance with one preferred embodiment of the invention, application of the tablecloth or table cover is described herein, with reference to FIGS. 4A-4C. Two formed corners 52 of the tablecloth 50 are first locked onto two corresponding corners on one lateral side of the tabletop 60, as shown in FIG. 4A. Then, the tablecloth 50 is drawn across the corners on the opposite sides of the table, as indicated by arrow “X” in FIG. 4B. Now, the resilient material 50 is pulled and stretched a little, and the rest two formed corners of the tablecloth 50 are locked onto two corresponding corners of the table as shown in FIG. 4C, thus allowing for a custom “fitted” top. Here, in order to prevent development of wrinkles on the fitted tablecloth 50, the resilient tablecloth 50 is to be adequately pulled and smoothed by the hands or with the aid of a ruler or a straight bar. The tablecloth 50 covers the top of the table as well as the lip around the four sides as shown in FIG. 4D. Such tables with their tabletops 60 covered by the resilient tablecloth 50 can be used, for example, as trade show tables. However, in accordance with another preferred embodiment of the invention as described herein below, the tables can be preferably covered by additional skirts around the side areas of the table. With reference now to FIG. 11, application of side skirts onto the covered table is described herein. Skirt 70 is preferably formed of fabric or a similar material which is tougher than the resilient tablecloth material. The skirt 70 has a width for suitably covering the sides of the table, and is provided in a roll 72. The skirt 70 may include a reinforced band 74 around the top area of the skirt. The band 74 is similarly formed of a fabric-like material and can provide a tougher foundation for applying staples or tacks, as will be described herein below. A free end of the rolled skirt 70 is first affixed onto a side of the tabletop 60 with staples 76 applied along the side of the tabletop 60 by using a suitable staple applicator 78. Instead of applying staples 76, other known fasteners such as pins, tacks, or the like can be applied either by hands or using an applicator known in the art. The remaining portion of the skirt 70 is now adequately placed onto the sides of the tabletop 60 and affixed there-around in a similar way. During installation of the skirt 70, the tablecloth may be further pulled tight to remove wrinkles. Also, it is advantageous to apply the fasteners (such as staples, tacks, or pins) onto the reinforced band 74 because it can more securely hold the staples or the like. Accordingly, covered tables of appealing appearance can be provided for using, for example, in a trade show. One preferred method for disassembly of the coverings (i.e., the skirt 70 and the tablecloth 50) is now described. First, one end side of the fabric skirt 70, which is affixed onto the tabletop 60 by staples 76, is pulled for disassembly. Since the skirt is formed of a fabric material and preferably reinforced with the band 74, this pulling action causes the corresponding portions of the fabric skirt 70 and the staples 76 to be detached from the tabletop 60 without damaging the skirt 70 and the tablecloth 50. The remaining portion of the skirt 70 is then pulled to complete the disassembly of the skirt and the staples (or tacks). Now, the tablecloth 50 is peeled off from the tabletop 60 in a reverse order to that of the application of the tablecloth as described above, and this completes the disassembly process. The tablecloth 50 removed from the tabletop 60 is typically discarded. However, since the removed tablecloth 50 my not be damaged, it can be reused for a later trade show. Although the invention has been described with reference to particular ingredients and formulations and the like, these are not intended to exhaust all possible arrangements or features, and indeed many other modifications and variations will be ascertainable to those of skill in the art. For example, the tablecloth of the invention may have a hexagonal (or other polygonal) shape, as described above, for accommodating with a similarly shaped tabletop. Then, its drop fold areas may have a different shape other than that described above to adequately fold and bind to an adjacent side drop. | <SOH> BACKGROUND OF THE INVENTION <EOH>Tables used in for instance, trade shows have been utilized for many years. The tables typically have several standard sizes. The visual appeal of the presentation is closely related to the success of the product being advertised. However, these tables are typically used many times over leading to wear and tear. Therefore, these tables used for trade shows generally require a covering to be placed over the top surface and partially down the side of the table in order to dress up the table and to better present the product being advertised. Referring to FIGS. 1 and 2 , the current industry way of topping trade show tables 10 is utilizing a white vinyl material 12 that comes on, for instance, rolls 14 , that is then cut by hand using scissors 16 to fit the approximate size of the table and then is stapled to the side of the table 10 using an industrial staple gun 18 . A fabric skirt is then attached to the edge of the table, also by stapling. This approach has many drawbacks. For instance, because the material 12 comes on a roll 14 and is manually cut to size, it is generally cut much larger than needed and sometimes under cut, therefore creating wasted material. Another problem is that current installation of the vinyl to the tabletop is to staple the material 12 directly to the sides of the table 10 . The staples 20 damage the wood upon insertion and when the vinyl 12 is removed after the show; it is torn off leaving the staples 20 in the table. This greatly reduces the life span of the table as well as many wasted man hours removing the staples 20 by hand using a staple removal tool 22 (see FIG. 3 ). Still another problem is that as the staples 20 accumulate on the side of the table 10 , it becomes increasing difficult to install the vinyl top and skirting. Also, as the tables 10 are removed as well as brought to the events they are placed on table dollies (not shown). During this procedure it is very common for equipment handlers to become injured from protruding staples. In addition, during such events, exhibitors themselves and attendees can become injured as well as clothing and trade show materials can become damaged from protruding un-removed staples. Finally, the current installation procedure is time consuming with the vinyl material 12 coming on 50 pound rolls 14 making it cumbersome to handle. | <SOH> SUMMARY OF THE INVENTION <EOH>What is desired then is an apparatus and method that will address the aforementioned problems. Accordingly, it is an object of the present invention to provide a tablecloth that may conveniently and quickly be affixed to a table and to provide an appealing visual presentation. This and other objects of the invention are achieved by providing a tablecloth that is pre-sized according to standard table dimensions. Some of the benefits to use of the present invention include for instance, there is no wasted material because the tablecloth is pre-cut to the correct size. In addition, the installation and removal of the tablecloth take very little time and pre-made tablecloths allow for a more exact piece count when, for instance, shipping to a show site. According to one aspect of the present invention, a table cover for covering a tabletop, comprises: a top cover for covering a top surface of a tabletop, the top cover having a generally polygonal contour with a plurality of sides at its outer periphery thereof; and, a plurality of side drops, each extending outwards from the respective one of the sides of the top cover, each of two adjacent ones of the side drops defining an adjoining corner with a first drop fold area and a second drop fold area configured to fold for binding the respective adjoining corner of the side drops with an adjacent side drop of the plurality of side drops. The first and second drop fold areas are preferably symmetrical to each other, configured to fold and bind by binding agents, sewing, application of heat, or other known binding methods. The table cover is useful, in particular, as a trade show tablecloth. The table cover is preferably formed of a resilient material such as vinyl, and the top cover can be made to a dimension a little shorter than that of the tabletop and is applicable to cover the tabletop by stretching it. According to another aspect of the present invention, a table cover for covering a tabletop, comprises: a top cover for covering a top surface of a tabletop, the top cover formed of a resilient material and sized a little smaller than the top surface of the tabletop, the top cover including a plurality of sides at its outer periphery thereof; and, a plurality of side drops formed of a resilient material, each of the side drops extending outwards from the respective one of the sides of the top cover, each of two adjacent ones of the side drops defining an adjoining corner, each of the adjoining corners being folded and bound respectively to an adjacent side drop of the plurality of side drops. According to another aspect of the present invention, a covered table comprises a tabletop covered with a resilient table cover, the table cover having a top cover and a plurality of side drop portions extending from the top cover, each of two adjacent side drop portions defining an adjoining corner area there-between, the adjoining corner areas each being folded and bound to at least one of two adjacent side drop portions of the table cover, thereby forming a plurality of fitted corners of the table cover. The covered table preferably includes a skirt attached around the sides of the tabletop on top of the fitted sides of the table cover. The skirt can be formed of a fabric material and attached to the tabletop by applying a plurality of staples, tacks, or pins. According to another aspect of the present invention, a method of making a table cover for covering a tabletop, comprises: providing a table cover formed of a resilient material and having a top cover and a plurality of side drop portions, the top cover being sized a little smaller than the top surface of the tabletop, the side drop portions including a plurality of adjoining corner areas between two adjacent side drop portions, each of the corner area including a first drop fold area and a second drop fold area; folding each of the adjoining corner areas about the first and second drop fold areas; and, binding each of the folded adjoining corner areas with adjacent side drop portions of the table cover so as to make the side drop portions drawn in a generally vertical direction when the table cover is placed over the tabletop. According to still another aspect of the present invention, a method of placing a table cover over a tabletop, comprising: providing a table cover formed of a resilient material and having a top cover and a plurality of side drop portions, the top cover being sized a little smaller than the top surface of the tabletop, the side drop portions including an adjoining corner area between two adjacent side drop portions, each of the corner area including a first drop fold area and a second drop fold area, the adjoining corner area being folded and bound to at least one of the two adjacent side drop portions of the table cover, thereby forming a plurality of fitted corners of the table cover; locking at least two of the fitted corners of the table cover onto corresponding corners of the tabletop; pulling and stretching the table cover across over opposite corners of the tabletop; and, locking the rest of the fitted corners of the table cover onto corresponding corners of the tabletop. According to a further aspect of the present invention, a method of applying table coverings onto a table, the table having a tabletop, the method comprises: providing a table cover formed of a resilient material and having a top cover and a plurality of side drop portions, the top cover being sized a little smaller than the top surface of the tabletop, the side drop portions including an adjoining corner area between two adjacent side drop portions, each of the corner area including a first drop fold area and a second drop fold area, the adjoining corner area being folded and bound to at least one of the two adjacent side drop portions of the table cover, thereby forming a plurality of fitted corners of the table cover; locking at least two of the fitted corners of the table cover onto corresponding corners of the tabletop; pulling and stretching the table cover across over opposite corners of the tabletop; locking the rest of the fitted corners of the table cover onto corresponding corners of the tabletop; providing a skirt formed of a fabric material and dimensioned to cover side areas of the table; and, attaching the skirt around the tabletop on top of the fitted sides of the table cover. The invention and its particular features and advantages will become more apparent form the following detailed description considered with reference to the accompanying drawings. | 20040129 | 20120612 | 20050623 | 96010.0 | 1 | CHEN, JOSE V | TABLECLOTH COVERING AND METHOD OF COVERING AND SKIRTING A TABLE | SMALL | 0 | ACCEPTED | 2,004 |
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10,767,349 | ACCEPTED | CONCRETE CASK AND METHOD FOR MANUFACTURING THEREOF | It is an object of the present invention to obtain a containment concrete cask which has heat removal capacity maintained at the conventional level or beyond it and which prevents radiation from leaking to the outside. In a concrete cask, a shielding body composed of concrete and heat transfer fins made from metal are provided between an inner shell and an outer shell made from metal, and an accommodation portion for accommodating a radioactive substance is provided inside the inner shell. The accommodation portion has a containment structure to be insulated from the outside of the cask. In the heat transfer fins, the portions thereof at the outer shellside are provided in contact with the outer shell and the portions thereof at the inner shell side are cut so as to form a separation portion with respect to the inner shell. | 1. A concrete cask comprising: an inner shell made from metal; an outer shell made from metal; a shielding body composed of concrete and provided between said inner shell and said outer shell; heat transfer fins provided between said inner shell and said outer shell; and an accommodation portion formed inside said inner shell for accommodating a radioactive substance therein thereby being kept from the outside of the cask, wherein said concrete includes portland cement, and said heat transfer fins each has an inner shell-side and an outer shell-side and is configured such that said inner shell-side is in contact with the inner shell and the outer shell-side is formed with at least a portion that is not in contact with the outer shell; or such that said outer shell-side is in contact with the outer shell and the inner shell-side is formed with at least a portion that is not in contact with the inner shell. 2. The concrete cask according to claim 1, comprising at least a first heat transfer fin provided in contact with said outer shell and a second heat transfer fin provided in contact with said inner shell, the first heat transfer fin and the second heat transfer fin being provided so as to overlap each other and so that there is a clearance between said first and said second heat transfer fins in said overlap portion. 3. The concrete cask according to claim 2, wherein when the length of the overlap portion of said first and said second heat transfer fins is denoted by w1 and the clearance between said first and said second heat transfer fins in the overlap portion is denoted by a1, then the following relation is satisfied: a1·(2·λb·w1·Lc)/(λf·t), where λc: thermal conductivity of the concrete (W/m·K); Lc: thickness of the concrete shielding body (m); λf: thermal conductivity of the heat transfer fins (W/m·K); t: thickness of the heat transfer fins (m). 4. The concrete cask according to claim 1, wherein the side of said heat transfer fins that forms said separation portion is formed to have substantially an L-like shape so as to be provided with an opposite surface facing said inner shell or said outer shell. 5. The concrete cask according to claim 4, wherein if the separation clearance of said separation portion is denoted by a2, the following relationship is satisfied: a2·(2·λc·w2·Lc)/(λf·t), where λc: thermal conductivity of the concrete (W/m·K); Lc: thickness of the concrete shielding body (m); λf: thermal conductivity of the heat transfer fins (W/m·K); t: thickness of the heat transfer fins (m); w2: length of said opposite surface in the width direction (m). 6. The concrete cask according to claim 1, wherein said heat transfer fins are formed to have substantially an I-like shape, when viewed from the shell end. 7. The concrete cask according to claim 1, wherein said separation portion is composed so as to separate completely the heat transfer fins and the inner shell or outer shell. 8. The concrete cask according to claim 1, wherein said heat transfer fins are disposed at an angle to the radial direction of said shielding body. 9. The concrete cask according to claim 1, wherein openings are formed in said heat transfer fins. 10. A concrete cask comprising: an inner shell made from metal; an outer shell made from metal; a shielding body composed of concrete and provided between said inner shell and said outer shell; and an accommodation portion for accommodating a radioactive substance inside said inner shell thereby being kept from the outside of the cask, wherein said shielding body is composed of said concrete including portland cement and a metal material that has a high thermal conductivity. 11. The concrete cask according to claim 10, wherein the thermal conductivity of the shielding body is 4 (W/m·K) or more. 12. The concrete cask according to claim 1, wherein said shielding body comprises a metal material in at least one shape of grains, particles, or fibers. 13. The concrete cask according to claim 10, wherein said shielding body comprises a metal material in at least one shape of grains, particles, or fibers. 14. The concrete cask according to claim 1, wherein said shielding body contains 15 mass % or more of hydroxide retaining water as crystals with a melting point and decomposition temperature higher than 100° C. 15. The concrete cask according to claim 10, wherein said shielding body contains 15 mass % or more of hydroxide retaining water as crystals with a melting point and decomposition temperature higher than 100° C. 16. The concrete cask according to claim 15, wherein said hydroxide shows poor solubility or insolubility in water. 17. The concrete cask according to claim 1, wherein said shielding body is sealed so as to be shielded from outside air. 18. The concrete cask according to claim 10, wherein said shielding body is sealed so as to be shielded from outside air. 19. A method for manufacturing the concrete cask comprising: an inner shell made from metal; an outer shell made from metal; a shielding body composed of concrete and provided between said inner shell and said outer shell; heat transfer fins provided between said inner shell and said outer shell; and an accommodation portion formed inside said inner shell for accommodating a radioactive substance, wherein a containment structure is employed to shield said accommodation portion from the outside of the cask, and said heat transfer fins each has an inner shell-side and an outer shell-side and is configured such that said inner shell-side is in contact with the inner shell and the outer shell-side is formed with at least a portion that is not in contact with the outer shell; or such that said outer shell-side is in contact with the outer shell and the inner shell-side is formed with at least a portion that is not in contact with the inner shell, comprising the step of: a mixing step for mixing a shielding body material that forms said shielding body and a placing step for placing the mixed shielding body materials, wherein said shielding body material is vacuum degassed in at least one of the steps. 20. The method for manufacturing the concrete cask according to claim 19, wherein in said mixing step, the shielding body material is vacuum degassed by mixing the shielding body material in a mixing chamber of a mixing machine and degassing the inside of said mixing chamber with a vacuum pump. 21. The method for manufacturing the concrete cask according to claim 19, wherein in said placing step, the shielding body material is vacuum degassed by placing the shielding body material mixed in said mixing step into a space formed between said inner shell and said outer shell and degassing the space with a vacuum pump. 22. The method for manufacturing the concrete cask according to claim 20, wherein in said placing step, the shielding body material is vacuum degassed by placing the shielding body material mixed in said mixing step into a space formed between said inner shell and said outer shell and degassing the space with a vacuum pump. 23. The concrete cask according to claim 2, wherein said separation portion is composed so as to separate completely the heat transfer fins and the inner shell or outer shell. 24. The concrete cask according to claim 3, wherein said separation portion is composed so as to separate completely the heat transfer fins and the inner shell or outer shell. 25. The concrete cask according to claim 4, wherein said separation portion is composed so as to separate completely the heat transfer fins and the inner shell or outer shell. 26. The concrete cask according to claim 5, wherein said separation portion is composed so as to separate completely the heat transfer fins and the inner shell or outer shell. 27. The concrete cask according to claim 6, wherein said separation portion is composed so as to separate completely the heat transfer fins and the inner shell or outer shell. 28. The concrete cask according to claim 1, wherein said radioactive substance is contained in a canister which includes a body and a lid, and said canister is placed in said accommodation portion. 29. The concrete cask according to claim 10, wherein said radioactive substance is contained in a canister which includes a body and a lid, and said canister is placed in said accommodation portion. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete cask suitable for the transportation or long-term storage of radioactive material such as spent nuclear fuels. 2. Description of the Related Art Concrete casks described in Japanese Patent Applications Laid-open No. 2001-141891 and Japanese Patent No. 3342994 are known as the conventional concrete casks. Japanese Patent Application Laid-open No. 2001-141891 describes a representative conventional concrete cask provided in the top part thereof with a gas outlet opening and in the lower part thereof with a gas inlet opening. In this structure, convection is generated in a gap between the concrete cask and a canister so as to introduce outside air through the inlet opening and release it through the outlet opening. As a result, heat is removed from the canister (sealed container containing the spent fuel) that is stored inside the concrete cask. Japanese Patent No. 3342994 described a metal cask structure in which a neutron shielding material is provided between an outer shell and an inner shell. In order to enhance the heat transfer between the outer and inner shells, both ends of heat transfer fins made from a metal material with good thermal conduction, such as copper, are connected in their entirety to the inner shell and outer shell. The heat transfer fins are provided radially along the radial direction. In the structure of Japanese Patent Application Laid-open No. 2001-141891, heat is removed by providing gas inlet and outlet openings and introducing outside air. In this case, corrosion-inducing substances such as sea salt particles contained in the outside air are unavoidably introduced into the concrete cask and adhere to the canister surface. As a result the canister surface is corroded and sometimes stress corrosion cracking can occur under the combined effect with the residual stresses present in the vicinity of welds in the canister. Such cracking means that the containment of canister is disrupted and radioactive material can be emitted to the outside. Furthermore, because the above-mentioned openings serving as the inlet and outlet were the portions that were not covered with a shielding body (portions that lack shielding), radiation streaming from those openings could not be avoided. In the configuration described in Japanese Patent 3342994, the inner shell and outer shell were connected by both ends of the heat transfer fins in their entirety. Therefore, the problem was that no shielding body was present in the heat transfer fin portions and radiation penetrated through the heat transfer fins and streamed in the radial direction. Furthermore, because of the structure in which the heat transfer fins were in contact with the inner and outer shells, the neutron shielding material such as a concrete had to be placed in the spaces bounded by the inner and outer shells and heat transfer fins one by one, or structural blocks had to be assembled. In this case the manufacture was a time-consuming operation. It is an object of the present invention to provide a concrete cask that is effective in suppressing the radiation streaming and is easy to manufacture. SUMMARY OF THE INVENTION Problems addressed by the present invention are described hereinabove. In order to solve the above mentioned problems according to the present invention, a concrete cask in which a shielding body composed of concrete and heat transfer fins made from metal are provided between an inner shell and an outer shell made from metal and which comprises an accommodation portion formed inside the inner shell for accommodating a radioactive substance, a containment structure is employed to shield the accommodation portion from the outside of the cask, and in the heat transfer fins, the portions thereof at the inner shell-side are provided in contact with the inner shell and the portions thereof at the outer shell-side are cut so as to form a separation portion with respect to the outer shell, or the portions thereof at the outer shell-side are provided in contact with the outer shell and the portions thereof at the inner shell-side are cut so as to form a separation portion with respect to the inner shell. These and other objects, features, and advantages of the present invention will become more apparent upon reading the following detailed description along with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is partially cut-out perspective view illustrating the storage state of the concrete cask of the first embodiment in accordance with the present invention; FIG. 2A is a longitudinal sectional view of the concrete cask of the first embodiment; FIG. 2B is a lateral sectional view; FIG. 3 is a lateral sectional view of the concrete cask of the second embodiment; FIG. 4 is a lateral sectional view of the concrete cask of the third embodiment; FIG. 5 is a lateral sectional view of the concrete cask of the fourth embodiment; FIG. 6 is a lateral sectional view of the concrete cask of the fifth embodiment; FIG. 7 is a lateral sectional view of the concrete cask of the sixth embodiment; FIG. 8 is a lateral sectional view of the concrete cask of the seventh embodiment; FIG. 9 is a lateral sectional view of the concrete cask of the eighth embodiment; FIG. 10 is a partly enlarged lateral sectional view of the container of the fifth embodiment; FIG. 11 is a partly enlarged lateral sectional view of the container of the structure according to the comparative reference example (related technology); FIG. 12 is a partly enlarged lateral sectional view of the container of the third embodiment; FIG. 13 is a partly enlarged lateral sectional view of the container of the fourth embodiment; FIG. 14 is a partly enlarged lateral sectional view of the container in the structure without heat transfer fins; FIG. 15 illustrates a structural example of vacuum degassing during concrete mixing; FIG. 16 illustrates a structural example of vacuum degassing during concrete placing; FIG. 17A is a longitudinal sectional view of a sample in a heat transfer capacity verification test of concrete cask of the fifth embodiment; FIG. 17B is a lateral sectional view; and FIG. 18A is a longitudinal sectional view showing a heat transfer fin formed with a cutout potion on its radial end thereof; FIG. 18B is a longitudinal sectional view showing a heat transfer fin formed with an opening; FIG. 18C is an explanatory perspective view showing arrangement of heat transfer fins of the fifth embodiment and the openings formed thereon; and FIG. 18D is a longitudinal sectional view showing a heat transfer fin formed with openings. DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic structure of a concrete cask and the structure of heat transfer fins in the concrete cask will be described below. FIG. 1 is a perspective view with a partial cut-out illustrating the storage state of the concrete cask of the first embodiment of the present invention. FIG. 2A is a longitudinal sectional view of the concrete cask of the first embodiment, FIG. 2B is a lateral sectional view. The concrete cask A of the first embodiment shown in FIG. 1 and FIG. 2 is composed of a tubular container body 1 open at both ends. A canister (a) is provided inside the concrete cask A. The container body 1 has a structure in which a concrete container 3 is covered with an outer shell 4 made from carbon steel, a bottom cover 5 made from carbon steel, a thick flange made from carbon steel, and an inner shell 7 made from carbon steel. An accommodation portion for accommodating the canister (a) is constructed inside the inner shell 7 (inside the container body 1). A lid 2 has a structure in which a concrete lid member 8 is covered with a thick upper lid 9 made from carbon steel and a lower cover 10 made from carbon steel. Multiple heat transfer fins 11 made from copper, carbon steel, or aluminum alloy are embedded and installed in the container 3 so as to be connected to the inner wall of the outer shell 4, as shown in FIG. 1 or FIG. 2B. The heat transfer fins are not required to be provided along the entire length in the axial direction of the container and may be provided only in the zones necessary for heat emission. For example, it is not particularly necessary to provide the heat transfer fins in the portion below the canister. Disposing the lid 2 on the container body 1 seals the space (accommodation portion) inside the inner shell 7 and shields the concrete cask A from the outside. A seal monitoring device 12 is installed in the lid 2 to check the sealing state (see FIG. 1). The canister (a) is a sealed container composed of a container body 13 and a lid 14. The inside thereof is filled with a radioactive substance (x) such as spent nuclear fuel. As shown in FIG. 2B, multiple heat transfer fins 11 are provided equidistantly between the inner shell 7 and outer shell 4 in the tangential direction for enhancing the dissipation of heat emitted from the radioactive substance (x) to the outside of the concrete cask A. Respective heat transfer fins 11 are formed to have a flat shape (I-like shape in a lateral sectional view) and are disposed radially along the radial direction of the container 3. The end portions of the respective heat transfer fins 11 at the side of the outer shell 4 are connected to the inner wall of the outer shell 4, whereas the end portions thereof at the side of the inner shell 7 are provided with separation portions with respect to the outer wall of the inner shell 7. Thus, the ends at the inner side of heat transfer fins 11 are cut out and the end portions are located at an appropriate distance from the inner shell 7. As for the cut portions, the cutting is conducted along the entire axial direction of the container, and the heat transfer fins 11 and the inner shell 7 are completely separated. In the structure of the first embodiment, even if the radiation penetrates through the heat transfer fins 11 in the radial direction, because a separation portion is present between the inner shell 7 and the heat transfer fins 11, the radiation has to pass through the concrete 3 of the separation portion. It means that even when the radiation leaks in the radial direction, it has to pass through the concrete 3 serving as a shielding body, and the structure of the concrete cask A with excellent radiation shielding capacity can be provided. Another advantage of this structure is that the container 1 body can be manufactured easily. Thus, when the container 1 is manufactured, the inner and outer shells 7 and 4 are formed and then fresh concrete 3 is placed between the inner and outer shells 7 and 4. With respect to this issue, when the conventional configuration (configuration shown in FIG. 11), such as described in Japanese Patent No. 3342994, is manufactured, a fresh concrete 3 has to be placed in all the cells one by one (that is, in all the spaces separated by respective heat transfer fins 30 shown in FIG. 11). However, in the configuration of the present embodiment, the individual cells are linked together by the separation portion, and even when the fresh concrete 3 is poured in only one place, the fresh concrete can spread to all the cells. Therefore, the number of production process is reduced. Furthermore, the fact that the heat transfer fins 11 and the inner shell 7 are completely separated means that the inner and outer shells 7 and 4 are not connected by the heat transfer fins 11. Therefore, a manufacturing process can be employed by which the inner shell 7 and the outer shell 4 are produced separately in advance and then assembled. As a result, in this sense, too, the structure of the first embodiment can be advantageous in terms of reducing the number of production process. The above-described effects are also demonstrated in the second to eighth embodiments described hereinbelow. All those embodiments will be explained below. FIGS. 3 through 9 are the lateral sectional views of the second to eighth embodiments. In the second embodiment illustrated by a lateral sectional view in FIG. 3, the end portions of the heat transfer fins 11 at the side of the inner shell 7 are connected to the outer wall of the inner shell 7, whereas the end portions at the side of the outer shell 4 are disposed via a separation portion with respect to the inner wall of the outer shell 4. Thus, the heat transfer fins 11′ are disposed at a certain distance from the outer shell 4, that is the structure is inversed with respect to that of the first embodiment (FIG. 2B). In the third embodiment illustrated by a lateral sectional view in FIG. 4, the end portions of the heat transfer fins 18 at the side of the outer shell 4 are connected to the inner wall of the outer shell 4, whereas the end portions at the side of the inner shell 7 (ends that form a separation portion with respect to the inner shell 7) are bent at an almost right angle along the appropriate width to obtain an L-like shape. As a result, the portions that were bent (bent portions) form opposite surfaces that face the outer wall of the inner surface 7 at an appropriate distance therefrom (separation portion). In the fourth embodiment illustrated by a lateral sectional view in FIG. 5, the end portions of the heat transfer fins 18′ at the side of the inner shell 7 are connected to the outer wall of the inner shell 7, whereas the end portions at the side of the outer shell 4 (ends that form a separation portion with respect to the outer shell 4) are bent at an almost right angle along the appropriate width to obtain an L-like shape. As a result, the portions that were bent (bent portions) form opposite surfaces that face the inner wall of the outer shell 4 at an appropriate distance therefrom (separation portion). In the above-described third and fourth embodiments, the heat transfer fins 18, 18′ have such bent portions. Therefore, a large surface area of the surfaces (opposite surfaces) of the heat transfer fins 18, 18′ that face the inner shell 7 or outer shell 4 can be ensured. As a result, heat transfer can be enhanced and a concrete cask A with excellent cooling capacity can be obtained. In the configuration of the fifth embodiment illustrated by a lateral sectional view in FIG. 6, first heat transfer fins 21 and second heat transfer fins 22 are disposed alternately and equidistantly in the tangential direction of the container 3. The first heat transfer fins 21 are cut so that the end portions thereof at the side of the outer shell 4 are connected to the inner wall of the outer shell 4, whereas the end portions thereof at the side of the inner shell 7 form a separation portion with respect to the outer wall of the inner shell 7. The second heat transfer fins 22 are cut so that the end portions thereof at the side of the inner shell 7 are connected to the outer wall of the inner shell 7, whereas the end portions thereof at the side of the outer shell 4 form a separation portion with respect to the inner wall of the outer shell 4. Heat transfer fins of one type (21 or 22) are disposed so as to be inserted between the adjacent fins (22 or 21) of the other type. As a result, the first heat transfer fins 21 and second heat transfer fins 22 have overlap portions in the radial direction of the container 3. In the structure of the fifth embodiment, the first heat transfer fins 21 and second heat transfer fins 22 have overlapping portions. Therefore, the advantage of this structure is that heat transfer between the heat transfer fins 21 and 22 is enhanced and excellent cooling effect is attained. Another merit of this structure is that because the heat transfer fins 21, 22 are formed to have a flat shape without bent portions, as in the first and second embodiments (the so-called I-like shape), bending of the heat transfer fins 21, 22 is not required and the number of processing operations can be reduced. In the sixth embodiment illustrated by the lateral sectional view in FIG. 7, the heat transfer fins 11 of the first embodiment are inclined at a prescribed angle from the radial direction of the container 3 (reference symbol 11b). A structure can be also considered in which the heat transfer fins 11′ of the second embodiment are similarly inclined at a prescribed angle from the radial direction (this structure is not shown in the figures). In the seventh embodiment illustrated by the lateral sectional view in FIG. 8, the portions of the heat transfer fins 18 of the third embodiment, which follow the radial direction of the container 3 (portions other than the aforesaid bend portions), are inclined at a prescribed angle from the radial direction of the container 3 (reference symbol 18b). A structure can be also considered in which the heat transfer fins 18′ of the fourth embodiment are similarly inclined at a prescribed angle from the radial direction (this structure is not shown in the figures). In the eighth embodiment illustrated by the lateral sectional view in FIG. 9, the first heat transfer fins 21 and second heat transfer fins 22 of the fifth embodiment are similarly inclined at a prescribed angle from the radial direction (reference symbols 21b, 22b). In those sixth to eighth embodiments, the heat transfer fins (11b, 18b, 21b, 22b) are disposed in an inclined state so as to decline from the radiation direction (radial direction of the container 3). The effect of such an arrangement is that streaming of radiation in the radial direction can be suppressed even more reliably. Further, the heat transfer capacity (heat removal capability) of the concrete cask will be explained hereinbelow with reference to the case in which heat transfer fins 21, 22 are installed alternately in a zigzag manner, as in the fifth embodiment. FIG. 10 is a partially expanded lateral sectional view of the container of the fifth embodiment, and FIG. 11 is a partially expanded lateral sectional view of the container with the configuration of the comparative reference example (conventional technology). It is well known that the equation relating to heat conduction can be represented by the following equation [A]: Q=λ×S×ΔT/L [A] where: λ: thermal conductivity of a thermally conductive substance (W/m·K); S: surface area of the heat transfer path of the thermally conductive substance (heat transfer surface area perpendicular to the direction of heat flux) (m2); ΔT: difference in temperature between the inner shell and outer shell (K); L: length of the heat transfer path (m). In the above-described fifth embodiment of the present invention in which a discontinuous portion is present in the heat transfer fins 21, 22, the following designations can be used: λc: thermal conductivity of the concrete shielding body 3 (W/m·K); Sc: surface area of the heat transfer path of the concrete shielding body 3 in the region where the heat transfer fins 21, 22 overlap (referred to hereinbelow as “overlap portion”)(m2); Tif: temperature of the heat transfer fins 22 at the side of the inner shell 7 in the overlap portion (K); Tof: temperature of the heat transfer fins 22 at the side of the outer shell 4 in the overlap portion (K); (a) distance between the heat transfer fins 21, 22 in the overlap portion (m), and λ=λc, S=Sc, ΔT=Tif−Tof, L=a can be substituted into the aforesaid equation [A]. As a result, the heat transfer quantity QI between the heat transfer fins of two types can be obtained in the following form: QI=λc×Sc(Tif−Tof)/a [C] Further, as a comparative reference example corresponding to the above-described configuration, a structure will be considered in which the inner and outer shells 7, 4 are directly connected by heat transfer fins 30 (structure shown in FIG. 11 disclosed in Japanese Patent Application Laid-open No. 2001-3342994). In this case, the following designations can be used: λf: thermal conductivity of the heat transfer fins 30 (W/m·K); Sf: surface area of the heat transfer fins 30(m2); Tis: temperature of the inner shell 7 (K); Tos: temperature of the outer shell 4 (K); Lc: thickness of the concrete shielding body 3(m), and λ=λf, S=Sf, ΔT=Tis−Tos, L=Lc can be substitute into the aforesaid equation [A]. The heat transfer quantity QP between the inner and outer shells in this structure can be obtained in the following form: QP=λf×Sf(Tis−Tos)/Lc [B] Here, the heat transfer capacity (QI) of the concrete area in the structure of the fifth embodiment is inevitably somewhat inferior to the heat transfer capacity (QP) in the structure in which the inner and outer shells 7, 4 were directly connected by the heat transfer fins 30. However, if the number of the heat transfer fins 21, 22 is increased to compensate for this deficiency, then the heat transfer capacity (heat removal capability) necessary for the concrete cask A can be ensured. However, because the arrangement space of heat transfer fins 21, 22 is also limited, limitations are also placed on the possibility of such compensation. Therefore, the heat transfer quantity QI of the concrete area of this embodiment can be assumed to be limited to ½ of the heat transfer quantity QP obtained in the case in which the inner and outer shells 7, 4 are directly connected to the heat transfer fins 30. Accordingly, if the condition QP×0.5≧QI [D] is satisfied, it will apparently be possible to obtain a concrete cask 4 in which the required heat transfer capacity can be actually attained, while effectively avoiding the radiation streaming as described hereinabove. Based on those results, the following formula (λf×Sf×(Tis−Tos)/Lc)×0.5≦λc×Sc×(Tif−Tof)/a [E] can be obtained by substituting formulas [B] and [C] into formula [D]. Here, when the heat transfer fins 30 are installed uniformly in the axial direction of the container 3, as in the comparative reference example shown in FIG. 11, the following equation is valid: Sf=t×M [F] Here, M stands for a length of the heat transfer fins 30 in the axial direction of the container 3. Further, in the fifth embodiment, when the heat transfer fins 21, 22 uniformly overlap in the axial direction of the container 3 (the case in which the lateral section of FIG. 10 appears uniform regardless of the position in the axial direction in which the container was cut), the following equation is valid: Sc=w×M [G] Here, w stands for a length of the overlap region of the first and second heat transfer fins 21, 22. Furthermore, when the heat conductivity of the heat transfer fins (21, 22, 30) is sufficiently large by comparison with that of the concrete shielding body 3, the following approximation is possible: Tis−Tos≈Tif−Tof [H] Therefore, substituting formulas [F]-[H] makes it possible to simplify the formula [E] as the formula [I] presented below: (λf×t)/Lc×0.5≦(λc−w)/a [I] The formula of claim 3 can be obtained from the formula [I]. The aforesaid formula [I] demonstrates that the heat transfer capacity (QI) in the concrete heat transfer region of the overlap portion in the fifth embodiment may be not less than the heat transfer capacity (QP) of the configuration of the comparative reference example, that is, the configuration in which the inner and outer shells 7, 4 were directly connected by the heat transfer fins 30, multiplied by 0.5 (QP×0.5≦QI). However, from the standpoint of the production cost and the number of operations, it is better to avoid the increase in the number of installed heat transfer fins 21, 22 even in the fifth embodiment. Furthermore, it is even more preferred that the heat transfer capacity QI be equal to or more than the heat transfer capacity QP obtained when the inner and outer shells 7, 4 are connected by the heat transfer fins 30 (QP≦QI). If the above-described formulas [F]-[H] are substituted into this formula, then formula [J] given below can be derived. (λf×t)/Lc≦(λc×w)/a [J] By equating the lefthand side and the right-hand side of the above mathematical expression [J], the relation of “w” (overlapping amount of heat transfer fins in radial direction) and “a” (separation amount at the overlapping portion) can be obtained in the desired case where the heat transfer capacity Qi and the heat transfer capacity Qp become equal to each other. Hereinafter, example values as practical example to be substituted into the mathematical expression are: λf=392 W/(m·K)(In case of Cupper Fin) λc=1.37W/(m·K)(In case of Concrete Material) Lc=0.855 m t=0.006 m Plug all the above values into the mathematical expression, then we get the following relation between “w” and “a”. w=2.0a (J-1) From the obtained relation in the above [J-1], it can be observed that the overlapping amount “w” needs to be set twice as much as the separation distance “a” in order to have a heat transfer capacity QI substantially the same as the heat transfer capacity Qp. Accordingly, from the following list, it is desirable to pick one or several value combination such that the flow of raw concrete during the filling of the space between the inner shell and the outer shell with concrete is not blocked. w (mm) a (mm) 20 10 40 20 60 30 80 40 100 50 120 60 141 70 161 80 181 90 201 100 Note the above values such as Lc and t are merely for the samples and the suitable values are to be determined for an individual situation. The heat transfer capacity (heat removal capacity) of the concrete cask A obtained when the L-shaped heat transfer fins 18 were mounted as in the third embodiment will be described below. FIG. 12 is a partially expanded lateral sectional view of the container of the third embodiment. Similarly to the approach followed with respect to formula [D] above, the heat transfer capacity (QI1) obtained when the heat transfer fins 18 are disposed on the side of the outer shell 4, as in the third embodiment, because of the formula QP×0.5≦QI1, the following condition should be satisfied: (λf×Sf(Tis−Tos)/Lc×0.5≦λc×Sc×(Tis−Tof)/a [K] Here, Sc: surface area of the heat transfer path of the concrete in the region between the bent portion at the distal end of the heat transfer fin 18 and the inner shell 7 (m2); Tof: temperature of the region (the aforesaid bent portion) of the heat transfer fin 18 that faces the inner shell 7 (K); a: distance between the region (the aforesaid bent portion) of the heat transfer fin 18 that faces the inner shell 7 and the inner shell 7 (m). The definitions of other parameters are absolutely identical to those of the parameters in the formulas of the above-described fifth embodiment and comparative reference example. When the thermal conductivity of the heat transfer fins (18, 30) is sufficiently larger than that of the concrete shielding body, the following formula is valid: Tis−Tos≈Tis−Tof [L] Furthermore, when the heat transfer fins 18 in the third embodiment are disposed uniformly in the axial direction, the equation Sc=w×M [M] is valid. Here, w stands for a length of the bent portion (portion facing the outer wall of the inner shell 7) of the heat transfer fin 18. Thus, w means the widthwise length of the opposite surface. Therefore, the aforesaid formula [K] can be simplified as follows: ((λf×t)/Lc)×0.5≦(λc×w)/a [N] The formula of claim 5 can be obtained from this formula [N]. Similarly to the approach followed with respect to formula [J] above, based on the formula QP≦QI1, it is preferred that the following formula be satisfied, which will allow the number of heat transfer fins 18 to be decreased: (λf×t)/Lc≦(λc×w)/a [O] The heat transfer capacity (heat removal capacity) of the concrete cask obtained when the L-shaped heat transfer fins 18′ were mounted on the side of the inner shell 7, as in the fourth embodiment, will be described below. FIG. 13 is a partially expanded lateral sectional view of the container of the fourth embodiment. Similarly to the approach followed with respect to formula [D] above, the heat transfer capacity (QI2) obtained when the heat transfer fins 18 are disposed on the side of the inner shell 7, as in the fourth embodiment (FIG. 13), because of the formula QP×0.5≦QI2, the following condition should be satisfied: (λf×Sf(Tis−Tos)/Lc×0.5≦λc×Sc×(Tif−Tos)/a [P] Here, Sc: surface area of the heat transfer path of the concrete in the region between the bent portion at the distal end of the heat transfer fin 18′ and the outer shell 4 (m2); Tif: temperature of the region (the aforesaid bent portion) of the heat transfer fin 18′ that faces the outer shell 4 (K); a: distance between the region (the aforesaid bent portion) of the heat transfer fin 18′ that faces the outer shell 4 and the outer shell 4 (m). The definitions of other parameters are absolutely identical to those of the parameters in the formulas of the above-described fifth embodiment and comparative reference example. When the thermal conductivity of the heat transfer fins (18′, 30) is sufficiently larger than that of the concrete shielding body, the following formula is valid: Tis−Tos≈Tif−Tos [Q] Furthermore, when the heat transfer fins 18′ in the fourth embodiment are disposed uniformly in the axial direction, the equation Sc=w×M [R] is valid. Here, w stands for a length of the bent portion (portion facing the inner wall of the outer shell 4) of the heat transfer fin 18′. Thus, w means the widthwise length of the opposite surface. Therefore, the aforesaid formula [K] can be simplified as follows: ((λf×t)/Lc)×0.5≦(λc×w)/a [S] The formula [S] is identical to the formula [N] and can be also used to obtain the formula of claim 5. Similarly to the approach followed with respect to formula [J] above, based on the formula QP≦QI2, it is preferred that the following formula be satisfied, which will allow the number of heat transfer fins 18′ to be decreased: (λf×t)/Lc≦(λc×w)/a [T] The heat transfer capacity (heat removal capacity) of the concrete cask having no heat transfer fins will be explained below. FIG. 14 is a partially expanded lateral sectional view of the container with a configuration containing no heat transfer fins. An assumption will be made that in the structure shown in FIG. 14 heat transfer fins 31 are present in the radial direction between the inner and outer shells 7, 4, and the width of the region of the concrete shielding body 3 of one-pitch spacing sandwiching the heat transfer fin 31 will be denoted by w. Further, the following designations will be used: Lc: thickness of the concrete shielding body 3 (m); a: length of the virtual heat transfer fin 31 in the radial direction (m); λc: thermal conductivity of the concrete shielding body 3 (W/m·K); λf: thermal conductivity of the virtual heat transfer fin 31 (W/m·K); t: thickness of the virtual heat transfer fin 31 (m); w: width of the region of the concrete shielding body 3 of one-pitch spacing sandwiching the heat transfer fin 31 (m). In this case, as a singular example of the above-described formulas [N] and [S], the following equation is valid: Lc=a [U] Therefore, the following formula is valid: λf×t≦λc×w [V] This formula [V] means that if a concrete is used that has thermal conductivity satisfying the relation described by the aforesaid formulas, then a concrete cask with a sufficient heat removal capacity can be designed (even if the heat transfer fins that have been considered indispensable in the past are absent). The thermal conductivity of a concrete shielding material enabling the heat removal design without heat transfer fins will be found hereinbelow by assuming a specific design structure of the concrete cask. The size, caloric value, and temperature difference between the inner and outer shells in the cask for which the heat removal capacity is to be established are substituted into the aforesaid formula [A] (Q=λ×s×ΔT/L). Those values were obtained by preliminary testing. More specifically, those values are: Internal caloric value: Q=14 kW. Difference in temperature between the inner shell 7 and the outer shell 4: ΔT=50K. Thickness of the shielding body: L=Lc=0.35 m. Inner diameter of the inner shell 7: D=1.6 m. Length of the heat-generating region in the axial direction: M=3.7 m. As for the heat transfer path surface area S, the virtual cylinder obtained by dividing the shielding body 3 into two equal sections in the radial direction is considered and the surface area of the circumference thereof is considered as a mean heat transfer path surface area. Furthermore, to simplify the calculations, the thickness of the inner and outer shells 7, 4 is ignored, and the diameter of the virtual cylinder is considered to be D+Lc. Therefore, the following equation is valid S=π(D+Lc)×M=π×(1.6+0.35)×3.7=23 (m2). If those numerical values are substituted into the equation (A), then λ=14000/23/50×0.35=4.3 (W/m·K). Thus, this calculation example shows that if a concrete shielding body with a thermal conductivity of at least about 4 W/m·k is prepared, then the heat removal capacity identical to that of the concrete cask of the conventional type having heat transfer fins can be demonstrated even without the heat transfer fins. A concrete material with the above-described excellent thermal conduction characteristic can be obtained by admixing copper or copper alloys having excellent thermal conduction characteristic in the form of a powder, fibers, lumps, and the like. Furthermore, from the standpoint of increasing the density (effective for gamma radiation shielding), in addition to improving the thermal conduction characteristic of this concrete material, the addition of a metal material or compounds comprising iron, copper, tungsten, and the like is also effective. Using copper or copper alloys for the above-described heat transfer fins (11, 11′, 18, 18′, 21, 22) is most preferred because of their excellent thermal conduction capacity and high corrosion resistance in the alkali environment of concrete. However, when the caloric value of the radioactive substance, x, introduced into the canister (a) is comparatively small, it is not necessary to use copper or copper alloys, and ferrous materials may be used. Examples of materials with an excellent heat transfer capacity also include aluminum and aluminum alloys, but because they are dissolved in alkali environment, they can hardly be used by mixing with concrete. However, if the surface thereof is plated or subjected to anodization, they still can be used as heat transfer fins for the concrete cask. Because the concrete cask A with the present structure does not allow for the ventilation of the canister (a) (the structure such as disclosed in Japanese Patent Application laid-open No. 2001-141891), it is highly probable that the concrete material will be exposed to a high temperature of 100° C. or higher. In such an atmosphere, the free water contained in the concrete material will be released. As a result, the content ratio of hydrogen (effective for neutron shielding) can be decreased and the neutron shielding capacity can be degraded. To prevent those effects, the necessary hydrogen content in the concrete material used for this concrete cask A can be maintained by admixing hydroxides retaining water (hydrogen) in the form of crystals, rather than retaining hydrogen in form of free water. In this case, even if the concrete temperature exceeds 100° C., the content of hydrogen necessary for neutron shielding will be present and the neutron shielding capacity of the concrete will be maintained as long as the decomposition temperature (temperature at which the dissociation pressure becomes 1 atm) and melting temperature of the hydroxides are not reached. It is preferred that the hydroxides be contained at a ratio of 15 mass % or more, based on the concrete material. Examples of hydroxides with a melting point and decomposition temperature higher than 100° C., that is, hydroxides in which water is not decomposed at a temperature of 100° C., include hydroxides of alkaline earth metals such as Ca, Sr, Ba, Ra and hydroxides of metals analogous thereto, e.g. Mg. Such hydroxides hold water (hydrogen) as water of crystallization when mixed with the cured product and have excellent neutron shielding capacity. For example, because the decomposition temperature of calcium hydroxide is 580° C. and the melting point of barium hydroxide is 325° C. and the decomposition temperature thereof is 998° C., those compounds retain water (hydrogen) up to a high-temperature range. Examples of other hydroxides that can be mixed with the composition or cured product include lithium hydroxide, sodium hydroxide, potassium hydroxide, lanthanum hydroxide, chromium hydroxide, manganese hydroxide, iron hydroxide, cobalt hydroxide, nickel hydroxide, copper hydroxide, zinc hydroxide, aluminum hydroxide, lead hydroxide, gold hydroxide, platinum hydroxide, and ammonium hydroxide. Furthermore, it is preferred that the hydroxide be insoluble or poorly soluble in water. Adding such hydroxides makes it possible to introduce reliably the hydroxides that do not release water by decomposing at a temperature of more than 100° C. in the cured product after hydration reaction with cement. The hydroxides for mixing with the concrete composition have a dissolution quantity in 100 g of pure water at 20° C. of 15 g or less, more preferably of 5 g or less, most preferably 1 g or less. In terms of solubility, too, the above-mentioned hydroxides of alkaline earth metal or Mg which is a metal analogous thereto are preferred. For example, the aforesaid dissolution quantity of hydroxides of calcium, strontium and magnesium is 1 g or less, and the dissolution quantity of barium hydroxide is 5 g or less. Among those hydroxides, the hydroxides of calcium and magnesium are especially effective for increasing the neutron shielding capacity because the ratio of hydrogen contained in these hydroxides is high due to a low atomic weight of Ca and Mg. Furthermore, because calcium contained in calcium hydroxide is the main component of Portland cement and because calcium hydroxide is a substance formed by a hydration reaction in usual cements, the calcium hydroxide is most preferred among the above-mentioned hydroxides. As described hereinabove, hydroxides are introduced into the present concrete material, thereby ensuring the necessary content of hydrogen. However, because hydroxides are sometimes decomposed by reacting with carbon dioxide present in the atmosphere and release water, they have to be shielded from the atmosphere. For example, in the case of calcium hydroxide, if it reacts with carbon dioxide present in the atmosphere, it eventually becomes calcium carbonate and water (hydrogen) can be released from the crystals, causing long-term degradation of neutron shielding capacity. This reaction is represented by the following chemical formula: Ca(OH)2+CO2→CaCO3+H2O To prevent this effect, in the present embodiment, the concrete material is provided in a space shielded by the inner shell 7, outer shell 4, flanges, and a bottom plate composed from a carbon steel, stainless steel and the like, as a concrete cask structure. The term “containment” as mentioned hereinabove means that outside air comprising carbon dioxide has no contact with the concrete cured body (the aforesaid concrete shielding body 3), and the “containment” in the aforesaid sense is not lost even if a safety relief valve is provided, for example in the outer shell 4, this valve serving to release gases generated during use of the concrete cask A to the outside. Moreover, the “containment” in the aforesaid sense may be substantially attained with a structure in which contact of the concrete cured body with carbon dioxide is prevented by adsorbing carbon dioxide with an adsorbent or the like. Degassing of concrete during the manufacture of the concrete cask A will be explained below. Thus, there is a high probability that the air will penetrate into the concrete and pores will be formed therein when the concrete is mixed and placed. When the container 3 is composed of such a concrete, the pores present therein become the loss areas of the shielding body, which is undesirable from the standpoint of preventing the streaming of radiation. Therefore, a method for vacuum degassing during mixing or placing may be used. FIG. 15 illustrates an example of the configuration for vacuum degassing during concrete mixing, and FIG. 16 illustrates an example of the configuration for vacuum degassing during concrete placing. Vacuum degassing during mixing can be conducted by employing a containment (sealed) structure of the mixing chamber of a mixing machine such as a pot mixer, a screw mixer, or a puddle mixer, and disposing a vacuum pump therein. An example of the configuration for vacuum degassing during concrete mixing is shown in FIG. 15. In FIG. 15, the reference numeral 61 stands for a pot-type concrete mixer with a mixing chamber constructed inside the pot. The pot is equipped with a disk-like vacuum flange 62 detachably provided in the opening 61a of the pot. The vacuum flange 62 has an appropriate containment structure and can air-tightly cover the opening 61a. As a result, the inside of the pot is sealed. An air suction opening (not shown in the figures) is formed on one side surface of the vacuum flange 62, and when the vacuum flange 62 is mounted on the concrete mixer 61, this air suction opening is connected to the space inside the pot. A boss portion is provided in a protruding condition in the center of the surface on the other side of the vacuum flange 62, and a linking hole 63 is formed in the boss portion. The linking hole 63 is connected to the aforesaid air suction opening via an appropriate path formed in the space inside the vacuum flange 62. One end of the flexible hose 65 is attached to the linking hole 63. In order to prevent the flexible hose from twisting, a rotary joint 64 is introduced into a place of connection to the linking hole 63. The other end of the flexible hose 65 is connected to the suction side of the vacuum pump 66. In the above-described structure, air bubbles are introduced into the concrete by mixing inside the pot, but the air bubbles can be sucked out and removed via the flexible hose 65 and the concrete can be degassed by degassing the inside of the mixing chamber by driving the vacuum pump 66 in parallel with the mixing operation. FIG. 16 illustrates a structure for vacuum degassing during concrete placing. In the structure shown in FIG. 16, a sealable lid 68 is disposed above the inner and outer shells 7, 4. In the lid, concrete placing holes 69 are provided in several zones and a suction opening 70 is formed. The suction opening 70 is connected via an appropriate hose 71 to a vacuum pump 72. A pipe denoted by the reference numeral 73 serves for feeding the concrete. When concrete is placed in this structure, fresh concrete is poured from the placing holes 69 into the space between the inner and outer shells 7, 4, and the vacuum pump 72 is driven to degas the space between the inner and outer shells 7, 4. As a result, the concrete is degassed. In the structure of the embodiments of the present invention, because the inner and outer shells 7, 4 are not entirely partitioned by the heat transfer fins (11, etc.), the fresh concrete can flow from one cell to another. As a result, the number of zones for disposing the concrete placing holes 69 can be reduced, as shown in FIG. 16. Further, the above-described easiness of concrete placement can be similarly improved even in the structure in which the heat transfer fins 180, each is formed with a cutout portion 180C, that is, cut only partially as shown in FIG. 18A, rather than completely, in the axial direction of the container 3 in the separation space like the one 181A shown in FIG. 18B. Needless to say the cutout similar to the one 180C can also be formed on the inner-side end of the heat transfer fin 180. Moreover, if through holes (openings 181C) are provided in addition to the aforesaid separation portion 181A in the heat transfer fins 181 as shown in FIG. 18B, then the concrete can be also caused to flow through those through holes 181C, thereby also increasing the easiness of placing. The shape, number and location of the openings may be appropriately set in balance with the above-described heat transfer capacity. For example, in the case of the zigzag arrangement of heat transfer fins 21, 22 as in the fifth embodiment as shown in FIG. 6, it is preferred that the openings, 182C1, 182C2, be provided in the regions aside of the overlap portions of the both the heat transfer fins 182A, 182B, in order to minimize the decrease in heat transfer capacity. Yet moreover, it may be possible to provide a heat transfer fin 183, as shown in FIG. 18D, having both of radial ends fixed to the outer shell 4 and the inner shell 7, respectively, and on which it is formed with a plurality of openings 183C1, 183C2 (not limited to the plural opening configuration but a single opening can be used). As described for the embodiments shown in FIGS. 18A, 18B, and 18C, the shape, number and location of the openings may be appropriately set in balance with the above-mentioned heat transfer capacity. Furthermore, any feasible combination of the openings shown in FIGS. 18A to 18D, can be made without departing the essential concept of the present invention. The verification test of heat transfer performance of the concrete cask will be described below. FIG. 17A is a longitudinal sectional view of a sample in the heat transfer capacity verification test of the concrete cask of the fifth embodiment. FIG. 17B is a lateral sectional view. A heat transfer sample C used in the verification test is shown in FIG. 17. The heat transfer sample C is equivalent to the structure in which a tubular portion of the container body 1 of the concrete cask of the fifth embodiment is cut out and comprises the aforesaid inner and outer shells 7, 4 and the concrete shielding body 3. As shown in FIG. 17A, both end surfaces in the axial direction of the heat transfer sample C are covered with thermally insulating materials 80, 80. A thermally insulating material 81 is also disposed inside the inner shell 7. A cylindrical gap of an appropriate thickness if formed between the thermally insulating material 81 and the inner shell 7, and a heater 82 for heating is disposed in this gap portion. The thermally insulating material 81 and heater 82 are not shown in FIG. 17B. In the structure shown in FIG. 17, a heat transfer test was carried out with a heater output of 2.1 kW. The heat transfer analysis was also conducted under the identical conditions and the analysis results were compared with the results of the heat transfer test. Here, (w) was 90 mm and (a) was 38 mm. The mixing composition of the concrete material used for the heat transfer test is shown in Table 1. The materials used for the sample are shown in Table 2. TABLE 1 mixing composition of the concrete material used for the heat transfer test Unit Amount (Kg/m3) Chemical Admixture high low performance de- heat Metal AE water form- Portland silica calcium iron iron reducing ing cement fume hydroxide powder fiber agent agent water 287 32 1131 640 157 94 0.9 281 TABLE 2 Materials Used for the Test Heat Thickness Conductivity Parts Name Material (mm) (W/m · K) Inner shell carbon steel 16 52 Outer shell carbon steel 16 52 Heat Trans cupper 2 398 Fin Shielding concrete 250 2.0 body Calculating (λf×t)/Lc and (λc×w)/a from those dimensions and physical property values, yields the following: (λf×t)/Lc=3.1 (W/m·K) (λc×w)/a=3.3 (W/m·K). It is clear, that the aforesaid formula [T], that is, (λf×t)/Lc≦(λc×w)/a, is satisfied. The results of the heat transfer test and heat transfer analysis are shown in Table 3. TABLE 3 results of the heat transfer test and heat transfer analysis (Unit: degree in Celsius) Temp of Inner Temp of Outer shell shell Test results 88 68 Result by Heat 88 67 Transfer Analysis The results matched well and the difference in temperature between the inner shell and outer shell was about 20° C. in both the heat transfer test and the heat transfer analysis. On the other hand, the difference in temperature between the inner shell and outer shell that was calculated for the conventional structure in which the inner and outer shells were connected by heat transfer fins by using the present test model was about 20° C. and was confirmed to be equal to that of the heat transfer test results and heat analysis results obtained for the concrete cask of the present invention. The above results proved that the concrete cask in accordance with the present invention has sufficient heat transfer capacity (heat removal capacity). Eight embodiments of the present invention are described above, but the present invention is not limited to the configurations of the above-described embodiments, and a variety of modifications can be made without departing from the essence of the present invention. For example, in the first embodiment, the explanation was conducted with respect to a concrete cask for accommodating a radioactive substance contained in a canister in an accommodation unit. However, the present invention is also applicable to a concrete cask accommodating a radioactive substance contained in a basket. Furthermore, in the above-described embodiments, the heat transfer fins (11, etc.) were installed radially along the axial direction of the container 3. However, a configuration may be also employed in which the heat transfer fins are formed to have a fan-like shape perpendicular to the axial direction of the container and are mounted with equal spacing in the axial direction, alternately on the inner and outer shells 7, 4, while ensuring the overlap region necessary for thermal conduction (modification example of the aforesaid fifth embodiment). Further, when a structure is used with the heat transfer fins having a fan-like shape, if air bubbles are introduced into the concrete during placing, the problem is that they hang on the heat transfer fins and are difficult to remove. In order to resolve this problem associated with degassing, the heat transfer fins may be inclined so that the edge portions thereof be higher than the mounting position or the heat transfer fins may be inclined spirally. The present invention has the above-described configuration and therefore produces the following effects. In summary, the present invention relates to a concrete cask, in which a shielding body composed of concrete and heat transfer fins made from metal are provided between an inner shell and an outer shell made from metal and which comprises an accommodation portion formed inside the inner shell for accommodating a radioactive substance, a containment structure is employed to shield the accommodation portion from the outside of the cask, and said heat transfer fins each has an inner shell-side and an outer shell-side and is configured such that said inner shell-side is in contact with the inner shell and the outer shell-side is formed with at least a portion that is not in contact with the outer shell or such that said outer shell-side is in contact with the outer shell and the inner shell-side is formed with at least a portion that is not in contact with the inner shell. Therefore, in the conventional structure in which the heat transfer fins were connected to both the inner shell and the outer shell, it was necessary to place the concrete in each cell individually, whereas in accordance with the present invention such a configuration is not necessary and the manufacture is facilitated. Furthermore, in the conventional structure, because the heat transfer fins could create a region in which the shielding body was not present over the entire range in the radial direction, there was a problem associated with radiation streaming. However, in accordance with the present invention, even if the radiation passes through the heat transfer fins, it also has to pass through the shielding body before it can reach the outer shell. Therefore, the radiation streaming can be suppressed. In the above described cask, the concrete cask may comprise at least first heat transfer fins provided in contact with the outer shell-side and second heat transfer fins provided in contact with the inner shell-side, the first heat transfer fins and second heat transfer fins being provided so as to overlap each other and so that there is a distance between both the heat transfer fins in the overlap portion. The advantage of this configuration is that, in addition to the effect identical to that of claim 1, because the overlap portion is present, thermally conductive properties can be sufficiently ensured by the discontinuous region of heat transfer fins. Furthermore, if the length of the overlap portion of the both the heat transfer fins is denoted by w1 and the distance between the both the heat transfer fins in the overlap portion is denoted by a1, the following relationship is preferably satisfied: a1≦(2·λc·w1·Lc)/(λf·t). Therefore, heat transfer capacity equal to or better than that obtained when the heat transfer fins connect the outer and inner shells, as in the conventional configuration, can be obtained. Moreover, the side of the heat transfer fins that forms the separation portion can be formed to have an almost L-like shape so as to be provided with an opposite surface facing the inner shell or the outer shell. Therefore, heat transfer to the side opposite to that where the heat transfer fins are mounted can be enhanced. Furthermore, because the heat transfer fins are secured only to one shell of the inner shell and outer shell, the mounting time is shortened. Furthermore, if the separation distance of the separation portion is denoted by a2, the following relationship is satisfied: a2≦(2·λc·w2·Lc)/(λf·t). Therefore, heat transfer capacity equal to or better than that obtained when the heat transfer fins connect the outer and inner shells, as in the conventional configuration, can be obtained. As an alternate example, the heat transfer fins can be formed to have an almost I-like shape. Therefore, the manufacture of the heat transfer fins is facilitated and the production cost and the number of operations can be reduced. In one example, the separation portion can be composed so as to separate completely the heat transfer fins and the inner shell or outer shell. Therefore, because the heat transfer fins are mounted only on the outer shell or inner shell, the time required for mounting the heat transfer fins can be saved. Furthermore, because the inner shell and outer shell are not connected, the inner shell and outer shell can be manufactured independently. Therefore, the manufacturing process can be shortened. In another example, the heat transfer fins are disposed at an angle to the radial direction of the shielding body. Therefore, the radiation streaming can be avoided more reliably. Furthermore, openings can be formed in the heat transfer fins. Therefore, concrete can easily flow through the opening and concrete placing is facilitated. In another form of the embodiment of the present invention, a concrete cask comprising a shielding body composed of concrete and provided between the inner shell and the outer shell made from metal and an accommodation portion for accommodating a radioactive substance inside the inner shell, wherein a containment structure is employed to shield the accommodation portion from the outside of the cask, and the shielding body is composed of concrete that has good thermal conductivity comprising a metal material. Therefore, introducing a metal material increases thermal conduction capacity and makes it possible to provide a cut portion between the heat exchange fins and the inner shell or outer shell, thereby suppressing radiation streaming. Furthermore, the concrete density is increased and gamma radiation shielding capacity is increased. In the aforementioned embodiments, the thermal conductivity of the shielding body is preferably 4 (W/m·K) or more. Therefore sufficient thermal conduction capacity can be obtained. In particular, because a sufficient heat removal capacity can be attained even when no heat transfer fins are present, the heat transfer fins can be omitted and the structure of the concrete cask can be simplified. In the aforementioned embodiments, the shielding body comprises a metal material in at least one shape of grains, particles, or fibers. Therefore, thermal conduction capacity can be improved. Moreover, the shielding body preferably contains 15 mass % or more of hydroxide retaining water as crystals with a melting point and decomposition temperature higher than 100° C. Therefore, the shielding body has excellent neutron shielding capacity, in particular in a high-temperature environment with a temperature of 100° C. and higher. Yet moreover, the hydroxide shows poor solubility or insolubility in water. Therefore, the hydroxide that neither decomposes nor releases water at a temperature of 100° C. and higher can be reliably introduced into the cured body obtained after hydration with the cement. Furthermore, the shielding body is preferably sealed so as to be shielded from outside air. Therefore, the concrete material is prevented from reacting with carbon dioxide present in the atmosphere and releasing hydrogen present therein and the degradation of neutron shielding capacity can be prevented. The invention also related to a method for manufacturing the concrete cask, the method comprises a mixing step for mixing a shielding body material that forms the shielding body and a placing step for placing the mixed shielding body materials, wherein the shielding body material is vacuum degassed in at least one of those processes. Therefore, pores present in the concrete shielding body can be eliminated and a concrete cask with excellent shielding capacity can be obtained. In the mixing step, the shielding body material is vacuum degassed by mixing the shielding body material in a mixing chamber of a mixing machine and degassing the inside of the mixing chamber with a vacuum pump. Therefore, the introduction of air during mixing is prevented. As a result, pores present in the concrete shielding body can be eliminated and a concrete cask with excellent shielding capacity can be obtained. In the placing step, the shielding body material is vacuum degassed by placing the shielding body material mixed in the mixing step into a space formed between the inner shell and the outer shell and degassing the space with a vacuum pump. Therefore, the introduction of air during placing is prevented. As a result, pores present in the concrete shielding body can be eliminated and a concrete cask with excellent shielding capacity can be obtained. This application is based on Japanese patent application serial no. 2003-24208, filed in Japan Patent Office on Jan. 31, 2003, the contents of which are hereby incorporated by reference. Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be understood that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention hereinafter defined, they should be construed as being included therein. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a concrete cask suitable for the transportation or long-term storage of radioactive material such as spent nuclear fuels. 2. Description of the Related Art Concrete casks described in Japanese Patent Applications Laid-open No. 2001-141891 and Japanese Patent No. 3342994 are known as the conventional concrete casks. Japanese Patent Application Laid-open No. 2001-141891 describes a representative conventional concrete cask provided in the top part thereof with a gas outlet opening and in the lower part thereof with a gas inlet opening. In this structure, convection is generated in a gap between the concrete cask and a canister so as to introduce outside air through the inlet opening and release it through the outlet opening. As a result, heat is removed from the canister (sealed container containing the spent fuel) that is stored inside the concrete cask. Japanese Patent No. 3342994 described a metal cask structure in which a neutron shielding material is provided between an outer shell and an inner shell. In order to enhance the heat transfer between the outer and inner shells, both ends of heat transfer fins made from a metal material with good thermal conduction, such as copper, are connected in their entirety to the inner shell and outer shell. The heat transfer fins are provided radially along the radial direction. In the structure of Japanese Patent Application Laid-open No. 2001-141891, heat is removed by providing gas inlet and outlet openings and introducing outside air. In this case, corrosion-inducing substances such as sea salt particles contained in the outside air are unavoidably introduced into the concrete cask and adhere to the canister surface. As a result the canister surface is corroded and sometimes stress corrosion cracking can occur under the combined effect with the residual stresses present in the vicinity of welds in the canister. Such cracking means that the containment of canister is disrupted and radioactive material can be emitted to the outside. Furthermore, because the above-mentioned openings serving as the inlet and outlet were the portions that were not covered with a shielding body (portions that lack shielding), radiation streaming from those openings could not be avoided. In the configuration described in Japanese Patent 3342994, the inner shell and outer shell were connected by both ends of the heat transfer fins in their entirety. Therefore, the problem was that no shielding body was present in the heat transfer fin portions and radiation penetrated through the heat transfer fins and streamed in the radial direction. Furthermore, because of the structure in which the heat transfer fins were in contact with the inner and outer shells, the neutron shielding material such as a concrete had to be placed in the spaces bounded by the inner and outer shells and heat transfer fins one by one, or structural blocks had to be assembled. In this case the manufacture was a time-consuming operation. It is an object of the present invention to provide a concrete cask that is effective in suppressing the radiation streaming and is easy to manufacture. | <SOH> SUMMARY OF THE INVENTION <EOH>Problems addressed by the present invention are described hereinabove. In order to solve the above mentioned problems according to the present invention, a concrete cask in which a shielding body composed of concrete and heat transfer fins made from metal are provided between an inner shell and an outer shell made from metal and which comprises an accommodation portion formed inside the inner shell for accommodating a radioactive substance, a containment structure is employed to shield the accommodation portion from the outside of the cask, and in the heat transfer fins, the portions thereof at the inner shell-side are provided in contact with the inner shell and the portions thereof at the outer shell-side are cut so as to form a separation portion with respect to the outer shell, or the portions thereof at the outer shell-side are provided in contact with the outer shell and the portions thereof at the inner shell-side are cut so as to form a separation portion with respect to the inner shell. These and other objects, features, and advantages of the present invention will become more apparent upon reading the following detailed description along with the accompanying drawings. | 20040130 | 20061010 | 20061005 | 75182.0 | G21C1100 | 0 | QUASH, ANTHONY G | CONCRETE CASK AND METHOD FOR MANUFACTURING THEREOF | UNDISCOUNTED | 0 | ACCEPTED | G21C | 2,004 |
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10,767,477 | ACCEPTED | SEU and SEFI fault tolerant computer | A non-hardened processor is made fault tolerant to SEUs and SEFIs. A processor is provided utilizing time redundancy to detect and respond to SEUs. Comparison circuitry is provided in a radiation hardened module to provide special redundancy with the need to run additional processors. Additionally, a hardened SEFI circuit is provided to periodically send a signal to the process which, in the case of a processor not in the SEFI state, initiates production by the processor of a “correct” response. If the correct response is not received within a particular time window, the SEFI circuit initiates progressively severe actions until a reset is achieved. | 1. A fault tolerant computer comprising: a processor to execute instructions, said processor including instructions to execute an original and mirror instructions to produce results to be compared in a redundancy routine, a radiation hardened comparison circuit coupled to compare an original result and a first mirror result, said comparison circuit providing an output of a first state when said original result agrees with said mirror result and an output of a second state when said original result and said mirror result disagree, said second state comprising an SEU error signal. 2. A fault tolerant computer according to claim 1 wherein absence of an original or mirror result comprises disagreement with the other result. 3. A fault tolerant computer according to claim 1 wherein said comparison circuit output is coupled to inhibit production of additional mirror results when said output is in the first state. 4. A fault tolerant computer according to claim 3 wherein said processor is provided with instructions to perform an SEU recovery routine in response to detection of an SEU error signal. 5. A fault tolerant computer according to claim 4 wherein said processor comprises means for storing the original result and the mirror result in response to an SEU error signal, means coupling the SEU error signal to command production of a next original result and a next mirror result, coupling means coupling said original result for comparison with said next original result by said comparison circuit and coupling said mirror result for comparison with said next mirror result by said comparison circuit and said comparison circuit comprising means for producing a signal of the first state when at least one of the original result and next original result or the mirror result and next mirror result match to allow use of a result matching a next result by said processor. 6. A fault tolerant computer according to claim 5 wherein allowing use comprises transmitting the result to a processor bus. 7. A fault tolerant computer method comprising: executing an original and mirror instructions to produce an original and a mirror result respectively to be compared in a redundancy routine, comparing said original and mirror results in a radiation hardened comparison circuit, and providing an output of a first state when said original result agrees with said mirror result and an output of a second state when said original result and said mirror result disagree, said second state comprising an SEU error signal. 8. A method according to claim 7 comprising producing an output of the second state from said comparison circuit in the absence of the original or the mirror result. 9. A method according to claim 7 further comprising inhibiting production of additional mirror results when said output is in the first state. 10. A method according to claim 9 further comprising performing an SEU recovery routine in response to detection of an SEU error signal. 11. A method according to claim 10 further comprising storing the original result and the mirror result in response to an SEU error signal, coupling the SEU error signal to command production of a next original result and a next mirror result, coupling said original result for comparison with said next original result by said comparison circuit and coupling said mirror result for comparison with said next mirror result by said comparison circuit and producing in said comparison circuit a signal of the first state when at least one of the original result and next original result or the mirror result and next mirror result match to allow use of a result matching a next result by said processor. 12. A method according to claim 11 wherein allowing use comprises transmitting the result to a processor bus. 13. A programmed medium which when executed on a processor performs the steps of: executing an original and mirror instructions to produce an original and a mirror result respectively to be compared in a redundancy routine, and receiving signals indicative of a comparison by a radiation hardened comparison circuit, and responding to an output of a first state from said comparison circuit when said original result agrees with said mirror result to treat the original result as true and responding to an output of a second state from said comparison circuit when said original result and said mirror result disagree, said second state comprising an SEU error signal, to treat the original result as not true. 14. A medium according to claim 13 further performing the step of inhibiting production of additional mirror results when said output is in the first state. 15. A medium according to claim 14 further performing the step performing an SEU recovery routine in response to detection of an SEU error signal. 16. A medium according to claim 15 further performing the steps of storing the original result and the mirror result in response to an SEU error signal, coupling the SEU error signal to command production of a next original result and a next mirror result, coupling said original result for comparison with said next original result by said comparison circuit and coupling said mirror result for comparison with said next mirror result by said comparison circuit and responding to producing in said comparison circuit a signal of the first state when at least one of the original result and next original result or the mirror result and next mirror result match to allow use of a result matching a next result by said processor. | CROSS REFERENCE TO RELATED APPLICATIONS This patent application claims priority of provision patent application 60/442,727, filed Jan. 28, 2003. BACKGROUND OF THE INVENTION The present invention relates to fault tolerant computers and more specifically to a method and apparatus for operating in an error free manner when a microprocessor error is induced. Three basic factors contributing to the functioning of a computer, and more specifically to a microprocessor or microprocessors included in a computer are power, performance and environment-induced radiation effects. New models or generations of computers seek to achieve higher performance at lower power levels. Additionally, in applications in which microprocessors are exposed to ionizing radiation, it is necessary to provide a mechanism for maintaining reliable operation when it is a virtual certainty that the ionizing radiation will cause processor errors. An example of applications in which sufficient levels of radiation will be encountered to cause errors in spaceborne computers. In applications in which particle or ionizing radiation is not present, errors can be caused by other fault mechanisms such as electrically induced noise pulses. The most significant error events are Single Event Upset (SEU) and Single Event Functional Interrupt (SEFI). SEU is defined by NASA as “radiation-induced errors in microelectronic circuits caused when charged particles (usually from the radiation belts or from cosmic rays) lose energy by ionizing the medium through which they pass, leaving behind a wake of electron-hole pairs. In other words SEU is a change of state or transient induced by an energetic particle such as a cosmic ray or proton in a device. SEUs are “soft errors” in that a reset or rewriting of the device causes normal device behavior thereafter. However, the error must be accounted for when it is included in data to be acted upon. An SEFI is a condition in which an SEU in the device's control circuitry places the device into a test mode, halt, or undefined state. The SEFI halts normal operations, and is believed to require a power reset to recover. SEU error rates in a nominal application for commercial microprocessors can range from 0.2 to 9 MeV/mg/cm2. This range of rates is reflected in processor performance, depending on the processor and its environment, from a quite acceptable single upset per year to an unacceptable multiple upsets per hour. Improved SEU performance when designing microprocessor systems commonly results in increased power consumption. However, this technique does not solve the problem of SEUs and SEFIs due to radiation or electrically induced noise pulses. One prior art approach comprises utilizing radiation hardened microprocessors which will not be susceptible to the errors induced by radiation. However, radiation hardened microprocessors are not available in state of the art versions. They have over the past ten years lagged non-hardened processors by two to three generations. For example, currently available radiation hardened microprocessors include a 0.35 micron SOI (Silicon on Insulator) microprocessor and a 0.25 micron bulk CMOS on EPI processor (Complimentary Metal Oxide Semiconductor on Epitaxial Layer). However, state of the art microprocessors utilize 0.13 and 0.10 geometries. Radiation hardened microprocessors also lag the state of the art in terms of MIPS (Million Instructions Per Second) capability. Another known technique is TMR, triple modular redundancy, applied at the system level, also known as spatial redundancy. Three individual or discrete processors run instructions in parallel and synchronously. The outputs of the processors are sent to a comparator that utilizes voting logic. When an SEU occurs in one processor, the other two processors will still produce matching outputs. The comparator will pass the majority output. SEFI errors are treated as SEUs. However, the processor experiencing the SEFI will remain offline until reset or otherwise corrected. TMR triples the processor power requirements compared to a single processor. Synchronizing the processors is difficult, and operation must be slowed with respect to the speed achievable by a single processor. Time redundancy has been employed at the system level to provide the advantage of redundancy as described above while permitting the use of a single processor. In this technique, the processor executes the same instruction three times, or two times, comparing results, and runs a third time when the results do not agree. The result, or a checksum indicative of the result, is stored and the three stored outputs are compared. Three matching results indicate the absence of an SEU. If there is an SEU, a voting circuit selects the correct result. When the SEU corrupts data, the time redundancy technique will operate correctly. However, if the SEU causes an instruction to be corrupted, the technique will not operate correctly. A bit instructing a wrong operation will cause the wrong operation to be performed all three times. SEUs are not detected and SEFIs are not corrected. An improved form of time redundancy was developed by the Stanford Advanced Research and Global Observations Satellite Project (ARGOS). This technique is described in Oh, N., P. P. Shirvani and E.J. McCluskey, “Error Detection by Duplicated Instructions In Super-scalar Processors,” IEEE Transactions on Reliability, Vo. 49, No. 7, September 2001, pp. 273-284. Many errors were corrected, but still others were not. Another prior art alternative is to build a processor using commercial, non-radiation hardened integrated circuit process and apply known RHBD (radiation hardness by design) techniques to improve radiation hardness. Once again, as in the case of radiation hardened processors, die area is increased and operating speed are compromised. Also, while commercial switching logic utilizes simple flip-flops, RHBD logic requires latches built out of many flip-flops and further logic such as inverters. Performance comparable to commercial processors which are not radiation hardened is not provided. Examples of an improved radiation hardened system and a time redundant system are respectively disclosed in my copending patent application Ser. No. 10/435,626 filed May 6, 2003 entitled Fault Tolerant Computer and Ser. No. 10/656,720 (with a coinventor) filed Sep. 8, 2003 entitled Functional Interrupt Mitigation for Fault Tolerant Computer, the disclosures of which are incorporated by reference herein. It is desirable to provide a system in which a minimal amount of radiation hardening need be done. It is desirable to provide a system in which a time redundant system is also made space redundant, but in an efficient, reliable manner. For example, it is desired to avoid the problem of synchronizing a plurality of processors. There is little patent literature on SEFIs. Many testing efforts with microprocessors do not report SEFIs, or “hangs.” It is probable that all microprocessors will exhibit SEFIs whether they have been previously observed or not. This will include both commercial and radiation hardened devices. SEUs may take place in any transistor within a complex microprocessor. When the upset occurs in a memory location, whether a register or memory site, this can be measured and corrected. However, when the upset occurs in more subtle ways, the processor may be placed in a state from which it is not recoverable. An example is the case of an induced error in combinatorial logic or in state-machine transistors. It may be initially impossible to observe an error condition within the processor. However, the error may propagate within combinatorial logic. Other unrecoverable faults could include illegal branching, upset induced exceptions, upsets in the program counter or other unobservable faults. Work by such researchers as Dr. James W. Howard of Jackson and Tull Chartered Engineers of Washington, D.C. has demonstrated that SEFIs will occur in Pentium®, PowerPC and other processors. It is highly probable that all microprocessors will exhibit SEFIs whether they have been previously observed or not. It is therefor highly desirable to provide a way of detecting SEFIs so they may be responded to and also providing a way of responding to them. SUMMARY OF THE INVENTION Briefly stated, in accordance with the present invention, a method and apparatus are provided utilizing time redundancy combined with spatial redundancy in which benefits of modular redundancy are provided by in which the addition of components is minimized and in which benefits of time redundancy are provided with a minimum increase in operational complexity and in which errors not resolved by prior art time redundancy techniques are detected. SEUs are responded to. Additionally, the occurrence of SEFIs is accounted for. A non-hardened processor is made fault tolerant to SEUs and SEFIs. A processor is provided utilizing time redundancy combined with spatial redundancy, which is also referred by applicant's trademarks time-triple modular redundancy and TTMR, using a single processor to detect and respond to SEUs. External comparison circuitry is provided in a radiation hardened module to provide “TTMR” redundancy to protect for SEU errors on input output buses. Additionally, a hardened SEFI circuit is provided to periodically send a signal to the process which, in the case of a processor not in the SEFI state, initiates production by the processor of a “correct” response. If the correct response is not received within a particular time window, the SEFI circuit initiates progressively severe actions until a reset is achieved. Other aspects of the invention are further described below. This summary is neither exhaustive nor determinative of the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The invention may be further understood by reference to the following description taken in connection with the following drawings. Of the drawings: FIG. 1 is a block diagram of a computer constructed in accordance with the present invention including an SEU detection circuit and SEU recovery circuit; FIG. 2 is a timing diagram useful in understanding the operation of the embodiment of FIG. 1; FIG. 3 is a flow diagram illustrating the operation of the SEU recovery circuit and the programmed media commanding the operation; FIG. 4 is a flow diagram illustrating an alternative operation of the SEU recovery circuit and the programmed media commanding the operation; and FIG. 5 is a flow diagram illustrating the operation of the SEFI monitoring circuit of FIG. 1. DETAILED DESCRIPTION FIG. 1 is a block diagrammatic illustration of a processor 1 communicating via a bus 3 to peripheral devices 5. The processor 1 could, for example, be included in a satellite. The peripheral devices 5 may include a communication device 7 and sensors 8. Any number of well-known input and output devices may interact with the processor 1. The term processor is used here to denote a device which functions as a computer, e.g. a Pentium microprocessor chip, and does not describe only a subcomponent such as a discrete arithmetic unit. The processor 1 will in contemplated embodiments comprise a silicon chip, but may comprise any processor subject to the Single Event Upset (SEU) and Single Event Functional Interrupt (SEFI) phenomena, whether due to radiation or noise. It should be noted that a computer to be used in accordance with the present invention need not have the particular architecture as illustrated here. There are many well-known architectures providing the operation described here. Also, since microprocessor chips have many, many subsystems, it is common that representations of identical chips may take many different forms. Commercially available chips have detailed date sheets describing units available in the chips to perform various functions. In one preferred embodiment, the processor 1 is an Equator BSP-15 processor from Equator Technologies, Inc. of Campbell, Calif. The bus 3 may be interfaced to the peripheral devices 5 by a universal asynchronous receiver/transmitter (UART) 10. The processor 1 also uses a peripheral component interconnect (PCI) 12 to decouple a central processing unit 14, also coupled to the bus 3, from the relatively slow peripheral devices 5. Components of the processor 1 are coupled to communicate via the bus 3. The processor 1 comprises a main memory 18 which is a synchronous dynamic random access memory (SDRAM) 18 coupled to the bus 3. In other embodiments, other forms of dynamic storage could be utilized. The SDRAM 18 is controlled by an SDRAM controller 20. An instruction control unit 28 coupled to the bus 3 coordinates execution of program instructions, In the present embodiment, arithmetic operations are performed by an arithmetic logic unit 30. In the BSP 15 processor, the arithmetic logic unit 30 comprises first and second units 31 and 32. A clock control 36 and memory cache 38 are also coupled to the bus 3. An SEFI control circuit 40, discussed further below, is coupled to the bus 3. SEFI circuit 40 is external to processor 1. In the “time-triple modular redundancy” (TTMR) technique, a calculation is performed at times t0, t1, and t2, each time corresponding to a successive cycle of the bus 3. The results are polled for “two out of three” matching to assure a correct result. The present invention examines both memory and bus data transfers by adding an external hardware compare operation in the path of data being processed. The additional hardware should be radiation hardened. By simplifying the technique, the additional hardware, and thus the expense in its implementation is minimized. In the present invention, the computation is performed twice. The first computation is the original computation, and the second computation is referred to as a mirror calculation. If a match is obtained when the successive results produced at times t0 and t1 are compared, then two matching results are known to exist. It is, therefore, unnecessary to perform the third computation using the value produced at time t2. Since, in a nominal application, SEUs occur only about 1% of the time, it is not necessary to perform the third calculation 99% of the time. In an SEU detection circuit 48, a comparison of first and second signals is made by a comparator 50. As used herein, discrete logic primarily refers to a “hardware” rather than “software” implementation. While logic elements in FIG. 1 are illustrated as discrete logic elements, they do not need to be discrete components. The logic circuitry of FIG. 1 could be embodied in a larger chip either as separately identifiable components or embodied within an integrated circuit, e.g. a field programmable gate array (FPGA). A first input is provided to the comparator 50 from a delay line 52. A second input to the comparator 50 is coupled from the SDRAM 18. The comparator provides an output to the bus 3 having a first state indicative of a match between the two inputs or a second state indicate of a non-match. The second state is referred to as an SEU error flag. The SEU error flag initiates operation of the SEU recovery circuit 60. A first comparator 62 compares the outputs calculated at times t1 and t2. A second comparator compares 64 the results produced at times t0 and t2. Error flag logic circuit 66 receives the outputs of the comparators 62 and 64 to provide an output of the first state if either of the comparators 62 and 54 indicate a match. If there is not a match at either comparator 62 or 64, the error flag logic circuit produces an error signal to prohibit use of an incorrect calculation. Operation is described with respect to FIG. 2, which is a timing diagram. In FIG. 2, the abscissa is time, divided into cycles of the bus 3, and the ordinate is amplitude on an arbitrary scale indicative of logical zeros or ones. FIG. 2a illustrates the signal to the first input of the comparator 50, FIG. 2b illustrates the second input to the comparator 50 and FIG. 2c illustrates the output of the comparator 50. At time t0, an input indicative of a first result is supplied to the delay line 52 from the SDRAM 18 under the control of the SDRAM control 20. At time t1, an input indicative of a second result is supplied to the second input of the comparator 50 and also to the input of the delay line 52. By time t1, the first result has propagated to the first input of the comparator 50. Consequently, the comparator 50 compares the first and second results produced by the processor 1. If the inputs to the comparator agree, an output of the first state is provided by the comparator 50. This output is interpreted by the SDRAM control 20 so that the value produced by the calculation under consideration. The value is released for further processing in accordance with the programmed instructions. The input, delay and comparison process is not repeated. If the inputs do not agree, as illustrated in the example of FIG. 2, then the comparator 50 produces the SEU error flag. The SEU error flag is used to call operation of the SEU recovery circuit 60. Operation of the SEU recovery circuit is illustrated in FIG. 3, which is a flow diagram. In the situation in which an SEU occurs, at block 100, the SEU error flag is produced by the comparator 50 and supplied to the processor 3 to call the operation of FIG. 3. The SEU may also be detected in the absence of a value to be compared as well as in the case of a mismatch. Absence of a signal in the present example is the failure of an input to the comparator to occur prior to a timeout, which will not exceed on bus 3 cycle. At block 102, the inputs data to the comparator 50 are each written to a storage location. The original and mirror outputs produced at t0 and t1 are respectively referred to as C and C′. The processor 1 is commanded at block 104 to produce two further successive outputs at successive cycles of the bus 3. The results of the initial calculation and the mirror calculation are stored as D and D′ at block 106. In the nominal environment for the present invention, if there has been an SEU in the cycle in which C and C′ were produced, the probabilities are such that there should not be an SEU in the calculation of D and D′. C is compared to D at block 110. C′ is compared to D′ at block 112. At block 110, if C matches D, the value of C is treated as “true,” and the value of C is sent to bus 3 to be utilized as a valid result. At block 112, if C′ matches D′, the value of C′ is treated as “true,” and the value of C is sent to bus 3 to be utilized as a valid result. Alternatively, the method of FIG. 4 may be used to respond to an SEU error flag. At block 150, a command is issued to store instructions a each instruction is determined to be error free. At block 152, the SEU error flag is generated. At block 154, the stored commands are examined to determine the last instruction having an error free status. At block 156, the instruction control unit 28 is “decremented” to return to the last error free operation, and at block 158, the instruction stream is resumed and discarded operations are repeated. It is also desirable to detect SEFIs. These are faults from which the processor 1 does not recover. The SEFI circuit 40 (FIG. 1) is a radiation hardened circuit to monitor status of the processor 3 and reset it. As indicated in FIG. 5, at block 200, the SEFI circuit 40 provides a test signal to the processor 1. The period of the test signal production may be relatively long. The test signal 1 requires processing by the CPU 14, as indicated at block 202. If the processor 1 is not in the SEFI mode, it will respond by producing a “correct” answer as indicated at block 204. The SEFI circuit 40 must receive the correct answer before a preselected time-out, such as one or a preselected number of cycles of the bus 3. As indicated at block 206, if the correct answer is received, operation returns to block 200 to be resumed at the beginning of a next test signal period. If not, operation proceeds to block 210, where a corrective action routine is called. A first corrective action is initiated at block 212. This action is toggling of the interrupt of the CPU 14. At block 214, operation is tested. If the processor 1 is returned to a known, operative state, the operation ceases until the next test signal. If not, operation proceeds to block 216, which is a software reboot with a flag set to signify an SEFI event. At block 218, operation is tested. If the processor 1 is returned to a known, operative state, the operation ceases until the next test signal. Also, the SEFI circuit 40 may produce a “return from SEFI” flag. In not, operation proceeds to block 220. The corrective action at block 220 is a hardware reset utilizing the “reset” input of the CPU 14. At block 222, operation is tested. If the processor 1 is returned to a known, operative state, the operation ceases until the next test signal. If not, operation proceeds to block 224 at which the CPU 14 is run through a power cycle. At block 226, operation is tested. If the processor 1 is returned to a known, operative state, the operation ceases until the next test signal. If not, operation proceeds to block 228. At block 228, the processor 1 is powered down and then restarted. Each correction will attempt to return the CPU from SEFI by operating special software routines to self-test of roll back operation to return the hardware to a known state. The SEFI circuit 40 can be implemented by triple modular redundant FPGAs or it can be radiation hardened application specific integrated circuit (ASIC). Since the digital logic needed for the SEFI circuit 40 is estimated to be 6,000 gates, it can be implemented on a relatively small silicon chip at reasonable cost. Recovery capabilities are embedded in software routines, such as the ability to store selected data variables in memory for later recovery. Additional recovery capabilities are embedded in software routines such as the ability to store selected data variables in memory for later recovery in response to the “return from SEFI” flag. Software embodying the above operation may be made available to users with standard software tools and languages. The most common engineering language is C/C++. This language is supported by the Equator BSP-15 of the preferred embodiment and many widely used processors. A precompiler will duplicate computation code to produce mirror code to perform time redundant operations. The code produced for the present invention can be implemented in a real time operating system (RTOS). A preferred real time operating system is OSECK from Enea Embedded Technology of San Diego, Calif. The techniques of the present invention can be applied to the design of a new very long instruction work (VLIW) processor to achieve a greatly improved SEU and SEFI error rate using either hardware or software implementations. Advantageously, a microprocessor integrated circuit (IC or chip) may be designed from commercially available VLIW cores. Combined time and special redundancy and RHBD logic to a microprocessor with attention to SEU tolerance and performance will allow for significant advances in SEU hardened computing. The combined time and special redundancy can be adapted for both memory and bus data transfers by adding a hardware compare in SEU hardened logic in the data path along with the proper sequencing of data transfer and design of an SEU interrupt routine. The above teachings will enable those skilled in the art to take many departures from the specific examples above to produce systems in accordance with the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to fault tolerant computers and more specifically to a method and apparatus for operating in an error free manner when a microprocessor error is induced. Three basic factors contributing to the functioning of a computer, and more specifically to a microprocessor or microprocessors included in a computer are power, performance and environment-induced radiation effects. New models or generations of computers seek to achieve higher performance at lower power levels. Additionally, in applications in which microprocessors are exposed to ionizing radiation, it is necessary to provide a mechanism for maintaining reliable operation when it is a virtual certainty that the ionizing radiation will cause processor errors. An example of applications in which sufficient levels of radiation will be encountered to cause errors in spaceborne computers. In applications in which particle or ionizing radiation is not present, errors can be caused by other fault mechanisms such as electrically induced noise pulses. The most significant error events are Single Event Upset (SEU) and Single Event Functional Interrupt (SEFI). SEU is defined by NASA as “radiation-induced errors in microelectronic circuits caused when charged particles (usually from the radiation belts or from cosmic rays) lose energy by ionizing the medium through which they pass, leaving behind a wake of electron-hole pairs. In other words SEU is a change of state or transient induced by an energetic particle such as a cosmic ray or proton in a device. SEUs are “soft errors” in that a reset or rewriting of the device causes normal device behavior thereafter. However, the error must be accounted for when it is included in data to be acted upon. An SEFI is a condition in which an SEU in the device's control circuitry places the device into a test mode, halt, or undefined state. The SEFI halts normal operations, and is believed to require a power reset to recover. SEU error rates in a nominal application for commercial microprocessors can range from 0.2 to 9 MeV/mg/cm 2 . This range of rates is reflected in processor performance, depending on the processor and its environment, from a quite acceptable single upset per year to an unacceptable multiple upsets per hour. Improved SEU performance when designing microprocessor systems commonly results in increased power consumption. However, this technique does not solve the problem of SEUs and SEFIs due to radiation or electrically induced noise pulses. One prior art approach comprises utilizing radiation hardened microprocessors which will not be susceptible to the errors induced by radiation. However, radiation hardened microprocessors are not available in state of the art versions. They have over the past ten years lagged non-hardened processors by two to three generations. For example, currently available radiation hardened microprocessors include a 0.35 micron SOI (Silicon on Insulator) microprocessor and a 0.25 micron bulk CMOS on EPI processor (Complimentary Metal Oxide Semiconductor on Epitaxial Layer). However, state of the art microprocessors utilize 0.13 and 0.10 geometries. Radiation hardened microprocessors also lag the state of the art in terms of MIPS (Million Instructions Per Second) capability. Another known technique is TMR, triple modular redundancy, applied at the system level, also known as spatial redundancy. Three individual or discrete processors run instructions in parallel and synchronously. The outputs of the processors are sent to a comparator that utilizes voting logic. When an SEU occurs in one processor, the other two processors will still produce matching outputs. The comparator will pass the majority output. SEFI errors are treated as SEUs. However, the processor experiencing the SEFI will remain offline until reset or otherwise corrected. TMR triples the processor power requirements compared to a single processor. Synchronizing the processors is difficult, and operation must be slowed with respect to the speed achievable by a single processor. Time redundancy has been employed at the system level to provide the advantage of redundancy as described above while permitting the use of a single processor. In this technique, the processor executes the same instruction three times, or two times, comparing results, and runs a third time when the results do not agree. The result, or a checksum indicative of the result, is stored and the three stored outputs are compared. Three matching results indicate the absence of an SEU. If there is an SEU, a voting circuit selects the correct result. When the SEU corrupts data, the time redundancy technique will operate correctly. However, if the SEU causes an instruction to be corrupted, the technique will not operate correctly. A bit instructing a wrong operation will cause the wrong operation to be performed all three times. SEUs are not detected and SEFIs are not corrected. An improved form of time redundancy was developed by the Stanford Advanced Research and Global Observations Satellite Project (ARGOS). This technique is described in Oh, N., P. P. Shirvani and E.J. McCluskey, “ Error Detection by Duplicated Instructions In Super - scalar Processors,” IEEE Transactions on Reliability , Vo. 49, No. 7, September 2001, pp. 273-284. Many errors were corrected, but still others were not. Another prior art alternative is to build a processor using commercial, non-radiation hardened integrated circuit process and apply known RHBD (radiation hardness by design) techniques to improve radiation hardness. Once again, as in the case of radiation hardened processors, die area is increased and operating speed are compromised. Also, while commercial switching logic utilizes simple flip-flops, RHBD logic requires latches built out of many flip-flops and further logic such as inverters. Performance comparable to commercial processors which are not radiation hardened is not provided. Examples of an improved radiation hardened system and a time redundant system are respectively disclosed in my copending patent application Ser. No. 10/435,626 filed May 6, 2003 entitled Fault Tolerant Computer and Ser. No. 10/656,720 (with a coinventor) filed Sep. 8, 2003 entitled Functional Interrupt Mitigation for Fault Tolerant Computer, the disclosures of which are incorporated by reference herein. It is desirable to provide a system in which a minimal amount of radiation hardening need be done. It is desirable to provide a system in which a time redundant system is also made space redundant, but in an efficient, reliable manner. For example, it is desired to avoid the problem of synchronizing a plurality of processors. There is little patent literature on SEFIs. Many testing efforts with microprocessors do not report SEFIs, or “hangs.” It is probable that all microprocessors will exhibit SEFIs whether they have been previously observed or not. This will include both commercial and radiation hardened devices. SEUs may take place in any transistor within a complex microprocessor. When the upset occurs in a memory location, whether a register or memory site, this can be measured and corrected. However, when the upset occurs in more subtle ways, the processor may be placed in a state from which it is not recoverable. An example is the case of an induced error in combinatorial logic or in state-machine transistors. It may be initially impossible to observe an error condition within the processor. However, the error may propagate within combinatorial logic. Other unrecoverable faults could include illegal branching, upset induced exceptions, upsets in the program counter or other unobservable faults. Work by such researchers as Dr. James W. Howard of Jackson and Tull Chartered Engineers of Washington, D.C. has demonstrated that SEFIs will occur in Pentium®, PowerPC and other processors. It is highly probable that all microprocessors will exhibit SEFIs whether they have been previously observed or not. It is therefor highly desirable to provide a way of detecting SEFIs so they may be responded to and also providing a way of responding to them. | <SOH> SUMMARY OF THE INVENTION <EOH>Briefly stated, in accordance with the present invention, a method and apparatus are provided utilizing time redundancy combined with spatial redundancy in which benefits of modular redundancy are provided by in which the addition of components is minimized and in which benefits of time redundancy are provided with a minimum increase in operational complexity and in which errors not resolved by prior art time redundancy techniques are detected. SEUs are responded to. Additionally, the occurrence of SEFIs is accounted for. A non-hardened processor is made fault tolerant to SEUs and SEFIs. A processor is provided utilizing time redundancy combined with spatial redundancy, which is also referred by applicant's trademarks time-triple modular redundancy and TTMR, using a single processor to detect and respond to SEUs. External comparison circuitry is provided in a radiation hardened module to provide “TTMR” redundancy to protect for SEU errors on input output buses. Additionally, a hardened SEFI circuit is provided to periodically send a signal to the process which, in the case of a processor not in the SEFI state, initiates production by the processor of a “correct” response. If the correct response is not received within a particular time window, the SEFI circuit initiates progressively severe actions until a reset is achieved. Other aspects of the invention are further described below. This summary is neither exhaustive nor determinative of the scope of the present invention. | 20040128 | 20070821 | 20050106 | 74853.0 | 0 | LOHN, JOSHUA A | SEU AND SEFI FAULT TOLERANT COMPUTER | SMALL | 0 | ACCEPTED | 2,004 |
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10,767,633 | ACCEPTED | Finishing compositions with reduced volatile organic compounds | Finishing composition substantially free of non-volatile silicone materials and comprises a mixture of abrasive particles and an emulsion, which comprises water, a volatile siloxane, and a lubricant. | 1. A finishing composition comprising a mixture of abrasive particles and an emulsion, wherein: the emulsion comprises water, a volatile siloxane, and a lubricant; and the finishing composition is substantially free of non-volatile silicone materials. 2. The finishing composition of claim 1, wherein the volatile siloxane constitutes about 3-20% by weight of the finishing composition. 3. The finishing composition of claim 1, wherein the volatile siloxane comprises a volatile cyclic siloxane. 4. The finishing composition of claim 3, wherein the volatile cyclic siloxane is selected from a group consisting of octamethylcyclictetrasiloxane, decamethylcyclicpentasiloxane, dodecamethylcyclichexasiloxane, and combinations thereof. 5. The finishing composition of claim 1, wherein the finishing composition further comprises a volatile hydrocarbon solvent. 6. The finishing composition of claim 1, wherein the abrasive particles have an average particle size of about one-hundred micrometers or less. 7. The finishing composition of claim 1, wherein the abrasive particles is selected from a group consisting of aluminum oxide, silica, alumina silicates, silicon carbides, and combinations thereof. 8. The finishing composition of claim 7, wherein the volatile siloxane comprises a volatile cyclic siloxane. 9. The finishing composition of claim 1 wherein: the water constitutes about 10 to about 60% by weight of the finishing composition; the volatile siloxane constitutes about 3 to about 20% by weight of the finishing composition; the lubricant constitutes about 0. 1 to about 10% by weight of the finishing composition; and the abrasive particles constitute about 1 to about 60% by weight of the finishing composition. 10. The finishing composition of claim 9 wherein: the water constitutes about 30 to about 50% by weight of the finishing composition; the volatile siloxane constitutes about 5 to about 10% by weight of the finishing composition; the lubricant constitutes about 1 to about 5% by weight of the finishing composition; and the abrasive particles constitute about 3 to about 50% by weight of the finishing composition. 11. The finishing composition of claim 10, wherein the volatile siloxane comprises a volatile cyclic siloxane. 12. A finishing composition comprising: a volatile cyclic siloxane; a non-silicone-based lubricant; a thickening agent; a volatile hydrocarbon solvent; water; an emulsifier effective to create a stable emulsion comprising the volatile cyclic siloxane; and aluminum oxide particles; with the proviso that the finishing composition is substantially free of non-volatile silicone materials. 13. The finishing composition of claim 12, wherein the volatile cyclic siloxane is selected from a group consisting of octamethylcyclictetrasiloxane, decamethylcyclicpentasiloxane, dodecamethylcyclichexasiloxane, and combinations thereof. 14. The finishing composition of claim 12 wherein: the volatile siloxane constitutes about 3 to about 20% by weight of the finishing composition; the lubricant constitutes about 0.1 to about 10% by weight of the finishing composition; the thickening agent constitutes about 0.2 to about 5% by weight of the finishing composition; the volatile hydrocarbon solvent constitutes about 5 to about 17% by weight of the finishing composition; water constitutes about 10 to about 60% by weight of the finishing composition; the emulsifier constitutes about 0.1 to about 10% by weight of the finishing composition; and the abrasive particles constitute about 1 to about 60% by weight of the finishing composition. 15. A method of making a composition, said method comprising: combining a mixture of water, a volatile siloxane, a non-silicone-based lubricant, and an emulsifier to form an emulsion, wherein the emulsifier is effective to create a stable emulsion; and mixing abrasive particles into the emulsion to form the composition, with the proviso that there is a substantial absence of non-volatile silicone materials from the ingredients used in making the composition. 16. A method of finishing a surface, said method comprising: applying a finishing composition on the surface, wherein the finishing composition comprises water, abrasive particles, a volatile siloxane, a non-silicone-based lubricant, and an emulsifier effective to create a stable emulsion; and allowing the volatile siloxane to substantially evaporate from the surface and leave a remaining portion of the finishing composition on the surface, wherein the remaining portion of the finishing composition is substantially free of oily residue, provided that the finishing composition is substantially free of non-volatile silicone materials. | FIELD OF THE INVENTION The present invention relates to finishing compositions. More particularly, the present invention relates to finishing compositions that have low concentrations of volatile organic compounds and exhibit good handling properties. BACKGROUND Finishing compositions may be used as paint refinishing materials to remove scratches left by sanding operations, which remove paint defects on vehicle surfaces. Typically when removing a paint defect, the defect is sprayed with a clearcoat and then removed using an abrasive material (e.g., sandpaper). However, this leaves visible scratch marks on the vehicle surface. The scratch marks may be removed by applying and distributing a finishing composition with abrasive buffing pads. A surface-protective sealant (seal coat) may then optionally be applied. Conventional finishing compositions contain solvents to improve the handling properties of the compositions (e.g., working time, product deposition on the surface, pick-up with a buffing pad, and clean up). These solvents evaporate after the finishing is applied to the surface. However, environmental regulations require relatively low concentrations (e.g., less than 17 percent, by weight) of volatile organic compounds (VOC) in certain products. SUMMARY The present invention relates to a finishing composition that exhibits good handling properties and leaves substantially no oily residue after application. The inventive compositions can be formulated as compounds, polishes, or glazes for finishing surfaces such as painted surfaces, marine gel coats, metals, and ceramics. This finishing composition is substantially free of non-volatile silicone materials and includes a mixture of abrasive particles and an emulsion, in which the emulsion includes water, a volatile siloxane, and a lubricant. The term “non-volatile silicone material” is defined herein as a silicone having a boiling point of at least 250° C. selected from: a non-cyclic, silicone-containing material that exhibits a kinematic viscosity greater than 5 centistokes (cSt) (5.0×10−6 m2/s) at 25° C.; a non-cyclic, silicone-containing material that exhibits a kinematic viscosity of 5 cSt (5.0×10−6 m2/s) at 25° C. provided that the concentration of such non-cyclic silicone-containing material in the finishing composition is at least seven percent by weight; and a cyclic silicone-containing material that exhibits a kinematic viscosity greater than 7 cSt (7.0×10−6 m2/s) at 25° C. The inventive finishing composition uses environmentally acceptable solvents while avoiding the use of high boiling solvents in quantities that can leave oily residue on the surface to be treated, such as a vehicle surface being repaired. The oily residue is difficult to remove from the vehicle surface and visually obscures scratch marks to be removed. With such high boiling solvents, extra time and effort are required to ensure proper repair of the paint defects. Being free of non-volatile silicone materials and oily residue, the inventive finishing yields an improvement in the appearance of painted surfaces. The invention further relates to a method of making a composition. The method includes combining a mixture of water, a volatile siloxane, a non-silicone-based lubricant, and an emulsifier to form an emulsion, the emulsifier being effective to make a stable emulsion. Abrasive particles are mixed into the emulsion to complete formation of the composition. The invention further relates to a method of treating a surface. The method includes applying a finishing composition on the surface, the finishing composition comprising water, abrasive particles, a volatile siloxane, a non-silicone-based lubricant, and an emulsifier effective to create a stable emulsion. The volatile siloxane is allowed to substantially evaporate from the surface, and leave a remaining portion of the finishing composition on the surface, said remaining portion being substantially free of oily residue. DETAILED DESCRIPTION The present invention includes a finishing composition capable of functioning as a paint refinishing material, or rubbing compound, and includes a mixture of abrasive particles dispersed within an emulsion. The emulsion may be formed with an emulsifier, and includes water, a volatile siloxane, and a lubricant. The finishing composition exhibits good handling properties and leaves substantially no oily residue after application. The finishing composition is also substantially free of non-volatile silicone materials (i.e., less than 0.2% by weight of the finishing composition of the present invention). Prior finishing compositions incorporate non-volatile silicone materials to aid with handling properties, gloss, and water repellency. However, unlike volatile silicone materials, such as volatile siloxanes, non-volatile silicone materials do not evaporate after application. Non-volatile silicone materials create residual films that may diffuse into the surrounding air (e.g., as droplets in an automobile body shop) and contaminate other surfaces (such as other vehicles being painted). Use of non-volatile silicone materials in finishing compositions requires extra clean-up measures for facilities such as automobile-body repair shops. One or more volatile siloxanes are included in the finishing composition of the present invention to improve handling properties. A particularly important handling property affected by the volatile siloxane(s) is working time. Generally, finishing compositions should allow for a working time of about 4½ to about 5 minutes for a three-cycle process (i.e., applying and buffing the finishing composition three times to remove all scratch marks). The working time is generally governed by the rate of evaporation of volatile solvents in the finishing composition. If solvent evaporation is too fast, the working time may be too short to allow adequate removal of the scratch marks. Additional applications of the finishing material may then be required. If evaporation is too slow or non-existent, a residual film remains. The residual film or oily residue typically consists of non-evaporated high-boiling organic solvents. When volatile siloxanes evaporate from an applied film of the inventive finishing, the remaining portion of the finishing composition is at least substantially free of oily residue. The volatile siloxanes used in the present invention may include linear, cyclic, and branched structures, and combinations thereof all with a boiling point less than 250° C. In general, cyclic siloxanes retain volatility at higher kinematic viscosities than non-cyclic siloxanes. Suitable kinematic viscosities for non-cyclic volatile siloxanes are less than 5 cSt (5.0×10−6 m2/s) at 25° C., and may further include 5 cSt (5.0×10−6 m2/s) at 25° C. if the concentration of the non-cyclic volatile siloxanes in the finishing composition is less than about 7% by weight. For cyclic volatile siloxanes, suitable kinematic viscosities are 7 cSt (7.0×10−6 m2/s) at 25° C., or less. Siloxanes with higher kinematic viscosities at 25° C. are typically not very volatile, and may cause an undesirable effect when refinishing existing materials (called “fisheye” by painters). The fisheye effect is a beading of paint on a surface, which detracts from the desired appearance. Volatile linear siloxanes usable in the present invention may be represented by the average formula: (CH3)2SiO{SiO(CH3)2}aSi(CH3)3 in which suitable integer values for “a” include 0-5. Accordingly, examples of suitable volatile linear siloxanes include hexamethyldisiloxane, having a formula (CH3)3SiOSi(CH3)3; octamethyltrisiloxane, having a formula (CH3)3SiO(CH3)2Si(CH3)3; decamethyltetrasiloxane, having a formula (CH3)3SiO{SiO(CH3)2}2Si(CH3)3; dodecamethylpentasiloxane, having a formula (CH3)3{SiO(CH3)}3Si(CH3)3; tetradecamethylhexasiloxane, having a formula (CH3)3SiO{SiO(CH3)2}4Si(CH3)3; hexadecamethylheptasiloxane, having a formula (CH3)3SiO{SiO(CH3)2}5Si(CH3)3; and combinations thereof. Volatile cyclic siloxanes are particularly suitable materials for the volatile siloxane, and may be represented by the formula {SiO(CH3)2}b in which suitable integer values for “b” include 4-6. Examples of suitable volatile cyclic siloxanes include octamethylcyclotetrasiloxane, having a formula {(CH3)2SiO}4, and commercially available from Dow Corning Corp., Midland, Mich., under the trade designations “Dow Corning 244 and 344 Fluids” (kinematic viscosities of 0.25 cSt (2.5×10−7 m2/s) at 25° C.); decamethylcyclopentasiloxane, having a formula {(CH3)2SiO}5, and commercially available from Dow Corning Corp. under the trade designations “Dow Corning 245 and 345 Fluids” (kinematic viscosities of 4.2 cSt (4.2×10−6 m2/s) and 5 cSt (5.0×10−6 m2/s) at 25° C., respectively); dodecamethylcyclohexasiloxane, having a formula {(CH3)2SiO}6, and commercially available from Dow Corning Corp. under the trade designation “Dow Corning 246 Fluid” (kinematic viscosity of 6.8 cSt (6.8×10−6 m2/s) at 25° C.); and combinations thereof. Volatile branched siloxanes are derivations of volatile linear and cyclic siloxanes. Examples of volatile branched siloxanes usable in the present invention include heptamethyl-3-{(trimethylsilyl)oxy}trisiloxane, having a formula C10H30O3Si4; hexamethyl-3,3,bis{(trimethylsilyl)oxy}trisiloxane, having a formula C12H36O4Si5; pentamethyl{(trimethylsilyl)oxy}cyclotrisiloxane, having a formula C8H24O4Si4; heptamethyl{(trimethylsilyl)oxy}cyclotetrasiloxane, having a formula C10H30O5Si5; and combinations thereof. The suitable volatile siloxanes described herein may be used alone or in any combination. Similar information regarding suitable volatile siloxanes is disclosed in Bahr et al., U.S. Pat. No. 5,531,814, which is incorporated herein by reference in its entirety. The lubricants that may be used in the finishing composition include substantially silicone-free materials that aid the finishing composition in lubrication and handling properties. Examples of suitable lubricants include oils (e.g., mineral, pine, and paraffinic oils), oleic acid, glycerol, polypropylene glycols, polybutylene glycols, and combinations thereof. The emulsifier of the finishing composition may be any emulsifier useful in preparing stable oil-in-water emulsions or stable water-in-oil emulsions. A stable emulsion is one in which the dispersed phase remains dispersed substantially within the continuous phase over a long time, which substantially prevents phase separation over time (sufficient for storage of the composition). Examples of suitable emulsifiers include nonionic emulsifiers, anionic emulsifiers, cationic emulsifiers, and combinations thereof. Nonionic emulsifiers are particularly suitable for use with the finishing composition, and include alcohol ethoxylates (e.g., “Neodol”, commercially available from Shell Chemical, Houston, Tex.; “Tomadol”, commercially available from Tomah3 Products, Inc., Milton, Wis.; and “Tergitol”, commercially available from Dow Corning Corp.), alkyl phenol ethoxylates (e.g., “Triton”, commercially available from Dow Corning Co.; and “Macol OP 10 SP” commercially available from BASF Corp., Mount Olive, N.J.), polyoxypropolene/polyoxyethylene block copolymers (e.g., “Pluronic”, commercially available from BASF Corp.), sorbitan fatty esters (e.g., “Span”, commercially available from ICI Americas, Wilmington, Del.), castor oil (e.g., “Emulsion A Oil”, commercially available from CasChem, Bayonne, N.J.), polyoxyethylene fatty esters, polyoxyalkylene monostearates (e.g., “Tween”, commercially available from Uniquema, New Castle, Del.), alkynols (e.g., “Surfynol”, commercially available from Air Products and Chemicals, Inc., Allentown, Pa.), polyoxyethylene nonylphenols, polyoxyethylene fatty alcohols, and combinations thereof. Suitable anionic emulsifiers include alkyl-aryl sulphonates. Suitable cationic emulsifiers include polyoxyethylene fatty amines. Examples of suitable abrasive particles include aluminum oxides, silica, aluminum silicates, silicon carbides, and combinations thereof. Suitable average particle sizes range from about 0.1 to about 100 micrometers. Particularly suitable average particle sizes range from about 2 to about 50 micrometers. The type of filler used in the finishing composition generally provides the color of the finishing composition. For example, when incorporating silica abrasive particles, the finishing composition exhibits a tan-brown color. Alternatively, when incorporating aluminum oxide abrasive particles, the finishing composition exhibits a white color. All concentrations herein are expressed in weight percent, unless otherwise stated. Additionally, all amounts are expressed on a weight basis, unless otherwise stated. Suitable compositional ranges in the finishing composition include an effective amount of about 10.0% to about 60.0% water, about 3.0% to about 20.0% volatile siloxane, about 0.1% to about 10.0% lubricant, about 0.1% to about 10.0% emulsifier, and greater than 0% to about 60.0% abrasive particles. Particularly suitable compositional ranges include about 30.0% to about 50.0% water, about 5.0% to about 10.0% volatile siloxane, about 1.0% to about 5.0% lubricant, about 0.1% to about 5.0% emulsifier, and about 3.0% to about 50.0% abrasive particles. In addition to the components listed above, the finishing composition may also include other conventional additives for finishing compositions in appropriate amounts, such as thickening agents, volatile hydrocarbon solvents, preservatives, dispersants, and fragrances. Thickening agents may be incorporated into the finishing composition in effective amounts of about 0.2% to about 5.0%, more particularly about 0.5% to about 3.0%, to increase the viscosity and alter rheological characteristics. Examples of suitable thickening agents include carboxyvinyl resins (e.g., “Carbopol”, commercially available from Noveon Inc., Cleveland, Ohio), acrylics (e.g., “Acrysol”, commcerically available from Rohm and Haas Co., Philadelphia, Pa.), clay (e.g., “Bentone”, commercially available from Elementis Specialties Rheox, Highstown, N.J.), and combinations thereof. Thickening agents such as Acrysol acrylics are associative thickening agents, which require associated base chemicals. Base chemicals may be incorporated into the finishing composition in effectives amounts of about 0.05% to about 3.0%, more particularly about 0.1% to about 1.0%. Suitable base chemicals include monoethanolamine, diethanolamine, triethanolamine, morpholine, and combinations thereof. Volatile hydrocarbon solvents may be incorporated into the finishing composition to aid with handling properties. Any volatile hydrocarbon solvent(s) employed are desirably substantially silicone-free. The volatile hydrocarbon solvents may be present in the finishing composition in effective amounts of about 5.0% to about 17.0%, and more particularly in effective amounts of about 10.0% to about 17.0%. Examples of suitable volatile hydrocarbon solvents include petroleum distillates (e.g., “Stoddard Solvent” and “Mineral Spirits”, both commercially available from ExxonMobil Chemical Co., Houston, Tex.; “Unocal”, commercially available from Citgo Petroleum Corp., Rolling Meadows, Ill.; and “Varsol”, commercially available from ExxonMobil Chemical Co.), isoparaffin solvents (e.g., “Isopar”, commercially available from ExxonMobil Chemical Co.), saturated hydrocarbon solvents (e.g., “Drakesol”, commercially available from Penreco, Houston, Tex.), aliphatic hydrocarbon solvents (e.g., “Exxsol”, commercially available from ExxonMobil Chemical Co.), alcohols, ethoxylated alcohols, ethoxylated glycols, and combinations thereof. Examples of suitable preservatives include aqueous, non-chlorinated, non-metallic preservatives (e.g., “Nuosept”, commercially available from International Specialty Products, Wayne, N.J.), microbicide preservatives (e.g., “Nuocide”, commercially available from International Specialty Products, Wayne, N.J.), personal-care product preservatives (e.g., “Kathon” commercially available from Rohm and Haas Co.), and combinations thereof. The preservatives may be present in the finishing composition in effective amounts of about 0.1% to about 0.5%, and more particularly in effective amounts of about 0.1% to about 0.3%. Dispersants may be added to help disperse the abrasive particles in the emulsion of the finishing composition. Examples of suitable dispersants include anionic suspending agents (e.g., “Disperbyk”, Byk-Chemie USA, Melville, N.Y.), anionic wetting agents (e.g., “Bykumen”, Byk-Chemie USA), and combinations thereof. The dispersants may be present in the finishing composition in effective amounts of about 0.1% to about 5.0%, and more particularly in effective amounts of about 0.2% to about 3.0%. The finishing composition of the present invention may be formed by mixing water, the volatile siloxane, the lubricant, and, optionally, other additives, such as the volatile hydrocarbon solvent, the base chemical, and the preservative at room temperature. A stable emulsion may be formed at room temperature by combining the emulsifier and the mixture. After the stable emulsion is formed, abrasive particles may be mixed into the emulsion and dispersed. The dispersant may then be optionally added to disperse the abrasive particles in the emulsion. The thickening agent may then be optionally added in appropriate amounts to react with the optional base chemical for increasing the viscosity of the finishing composition. Once all of the desired components are incorporated, the finishing composition may be mixed using a high-shear mixer for about five minutes at room temperature. A suitable high-shear mixer includes a Premier model mixer, commercially available from the Dispersator Company, Temple, Pa. Once prepared, the finishing composition of the present invention may be used to remove paint defects on vehicle surfaces. After the defect has been sprayed with a clearcoat and removed with an abrasive material, scratch marks remain on the vehicle surface. The finishing composition of the present invention may then be applied and distributed on the vehicle surface with an abrasive buffing pad to remove the scratch marks. Because of the volatile siloxane, the finishing material exhibits good handling properties, such as an acceptable buffing time. After the initial application and buffing cycle is completed, the volatile siloxane evaporates from the remaining finishing composition. The portion of the finishing composition that remains is substantially free of oily residue, and provides a clear coating through which any remaining scratch marks are visible. Additional cycles of distributing the finishing composition on the surface with abrasive buffing pads may also take place. Preferably, this occurs using a series of abrasive buffing pads with decreasing abrasive to provide a finer rubbing effect on the vehicle surface. Generally, about three cycles, with a total working time of about 4½ to about 5 minutes, are sufficient to remove the scratch marks and provide a smooth surface upon completion. However, additional application and buffing cycles may be used as appropriate for individual needs. After completion, a surface-protective sealant (seal coat) may optionally be applied to the buffed surface. Property Analysis and Characterization Procedures Various analytical techniques are available for characterizing the finishing compositions of the present invention. Several of the analytical techniques are employed herein. An explanation of these analytical techniques follows. Surface Energy Test The following test method was used to qualitatively evaluate the surface energy of painted panels after being treated with various finishing compositions. Each finishing composition was applied (not buffed) onto a painted panel in a 5.1-centimeter (cm) diameter circle, and left for one minute. After the minute time period, the remaining finishing composition was wiped off. Krylon Black spray paint, commercially available from Sherwin Williams, Cleveland, Ohio, was then sprayed over the finishinged circle on the painted panel. The sprayed paint was then evaluated for fisheye beading (e.g., retraction and non-uniformity of the sprayed paint). If the finishinged circle was contaminated with a low surface energy residue, a fisheye beading of the paint would become visually noticeable within one minute. Working Time and Amount of Oily Residue Test The following test method was used to qualitatively evaluate the total working time and the amount of oily residue remaining for various finishing compositions. For each finishing composition eight grams of the finishing composition was applied to a 20.3 cm foam buffing pad, commercially available under the trade designation “Perfect-it”, part number 05723, from 3M Company, St. Paul, Minn. The buffing pad was attached to a buffing tool, model number DW849, from Dewalt Industrial Tool Company, Baltimore, Md. The buffing pad was then run at 1,500 rotations-per-minute (rpm) at a zero degree angle on a 45.7×61.0×0.081 cm unfinishinged black automotive test panel from ACT Laboratory, Hillsdale, Mich. The test panel included the following coatings: ED6060 E-coat; 764204 Primer; 542AB921 Basecoat; RK8010A Clearcoat. The test panel was buffed until either dry or until about 1½ to 2 minutes passed if a residual film still remained, whichever came first. The 1½ to 2 minute limit was imposed for the buffing cycle because after about 1½ minutes, the volatile materials within the finishing composition would have substantially evaporated. Any remaining residual film was difficult to remove within a reasonable time by buffing. After the buffing cycle, the amount of oily residue remaining was qualitatively determined. The buffing cycle was then repeated two more times on the same area of the test panel (i.e., a total of three buffing cycles). After the three buffing cycles, the total working time for the three buffing cycles was recorded. Table 1 provides a numerical scale for the total working time of all three buffing cycles and the amount of oily residue remaining after each buffing cycle. TABLE 1 Total Working Time Scale (seconds) Amount of Oily Residue 1 270-300 None 2 240-269 or 300-330 Light film 3 210-239 Moderate film 4 180-209 Heavy film 5 Less than 180 or Very heavy film greater than 330 A rating of 4 or greater was considered unacceptable for the total working time and for the amount of oily residue. EXAMPLES The present invention is more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those skilled in the art. Unless otherwise noted, all parts, percentages, and ratios reported in the following examples are on a weight basis, and all reagents used in the examples were obtained, or are available, from general chemical suppliers such as the Sigma-Aldrich Chemical Company, Saint Louis, Mo., or may be synthesized by conventional techniques. The following compositional abbreviations are used in the following Examples: “Siloxane 1”: Fluid mixture of decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane exhibiting a kinematic viscosity of 5 cSt (5.0×10−6 m2/s) at 25° C., and commercially available under the trade designation “Dow Corning 345 Fluid” from Dow Corning Corp., Midland, Mich.; “Siloxane 2”: Hexamethyldisiloxane liquid exhibiting a kinematic viscosity of 0.65 cSt (6.5×10−7 m2/s) at 25° C., and commercially available under the trade designation “Dow Corning 200 Fluid, 0.65 CST.” from Dow Corning Corp., Midland, Mich.; “Siloxane 3”: Polydimethylsiloxane liquid exhibiting a kinematic viscosity of 5 cSt (5.0×10−6 m2/s) at 25° C., and commercially available under the trade designation “Dow Corning 200 Fluid, 5 CST.” from Dow Corning Corp., Midland, Mich.; “Siloxane 4”: Polydimethylsiloxane liquid exhibiting a kinematic viscosity of 10 cSt (1.0×10−5 m2/s) at 25° C., and commercially available under the trade designation “Dow Corning 200 Fluid, 10 CST.” from Dow Corning Corp., Midland, Mich.; “Lubricant 1”: Paraffinic oil, commercially available under the trade designation “Sunpar 110” from Sunoco, Inc., Philadelphia, Pa.; “Lubricant 2”: Glycerol, commercially available from Witco Corporation, Memphis, Tenn.; “Lubricant 3”: Mineral oil, commercially available under the trade designation “Parol 70” from Penreco, Houston, Tex.; “Emulsifier 1”: Non-ionic surfactant, commercially available under the trade designation “Tomadol 1-5”, from Tomah3 Products, Inc., Milton, Wis.; “Emulsifier 2”: Acetylenic diol-ethylene oxide adduct surfactant, commercially available under the trade designation “Surfynol 465”, from Air Products and Chemicals, Inc., Allentown, Pa.; “Emulsifier 3”: Poly(oxyethylene)(20)-sorbitane monooleate non-ionic surfactant, commercially available under the trade designation “Tween 80” from Uniquema, New Castle, Del.; “Emulsifier 4”: 4-(1,1,3,3-Tetramethylbutyl)phenyl-polyethylene glycol non-ionic surfactant, commercially available under the trade designation “Triton X-45” from Dow Chemical Company, Midland, Mich.; “Emulsifier 5”: Non-ionic surfactant, commercially available under the trade designation “Tomadol 1-9”, from Tomah3 Products, Inc., Milton, Wis.; “Emulsifier 6”: Polyoxyethylene (10) octylphenol ether non-ionic surfactant, commercially available under the trade designation “Macol OP 10 SP” from BASF Corp., Mount Olive, N.J.; “Emulsifier 7”: Castor oil, commercially available under the trade designation “Emulsion A Oil” from CasChem Inc., Bayonne, N.J.; “Abrasive 1”: Aluminum oxide abrasive in a 40 weight percent aqueous dispersion, designated “784”, and manufactured by Ferro Corporation, Cleveland, Ohio; “Abrasive 2”: Aluminum silicate, commercially available under the trade designation “Kaopolite SF” from Imerys Performance Minerals, Dry Branch, Ga.; “Abrasive 3”: Aluminum silicate, commercially available under the trade designation “Kaopolite 1152” from Imerys Performance Minerals, Dry Branch, Ga.; “Abrasive 4”: Aluminum oxide abrasive, designated “783”, and manufactured by Ferro Corporation, Cleveland, Ohio; “Thickener”: Alkali swellable acrylic associative thickener, commercially available under the trade designation “Acrysol TT-615” from Rohm and Haas Co., Philadelphia, Pa.; “Base”: Triethanolamine, commercially available from Sigma-Aldrich Chemical Company, Saint Louis, Mo.; “Solvent 1”: Isoparaffin solvent, commercially available under the trade designation “Isopar H” from ExxonMobil Chemical Company, Houston, Tex.; “Solvent 2”: Isoparaffin solvent, commercially available under the trade designation “Isopar M” from ExxonMobil Chemical Company, Houston, Tex.; “Solvent 3”: De-aromitized aliphatic hydrocarbon solvent, commercially available under the trade designation “Exxsol D80” from ExxonMobil Chemical Company, Houston, Tex.; “Solvent 4”: Saturated hydrocarbon solvent, commercially available under the trade designation “Drakesol 165 AT” (formerly “Penreco 2251”) from Penreco, Houston, Tex.; “Solvent 5”: Petroleum distillate, commercially available under the trade designation “Stoddard Solvent” from ExxonMobil Chemical Company, Houston, Tex.; “Solvent 6”: Petroleum distillate commercially available under the trade designation “Mineral spirits” from ExxonMobil Chemical Company, Houston, Tex.; “Solvent 7”: Isoparaffin solvent, commercially available under the trade designation “Isopar G” from ExxonMobil Chemical Company, Houston, Tex.; “Preservative”: Aqueous, non-chlorinated, non-metallic preservative, commercially available under the trade designation “Nuosept 95” from International Specialty Products, Wayne, N.J. “Dispersant”: Anionic suspending agent, commercially available under the trade designation “Disperbyk” from Byk-Chemie USA, Melville, N.Y. Tables 2-19 provide component concentrations for finishing compositions of Examples 1-7 and Comparative Examples A-K, in weight percent based upon the total weight of the given finishing composition. Each finishing composition was formed with the following generalized procedure. The liquid components (e.g., deionized water, Siloxanes 1-4, Lubricants 1-3, Solvents 1-7, the Base, and the Preservative) were combined with the emulsifying component(s) (e.g., Emulsifiers 1-7) and mixed with a laboratory mixer at 21° C. for 15 minutes to form an emulsion. The abrasive particles (e.g., Abrasives 1-3) were then added to the emulsion and mixed with the laboratory mixer at 21° C. for 5 minutes to disperse the abrasive particles within the emulsion. The entire mixture was then mixed with a high-shear mixer (Premier model, commercially available from the Dispersator Co., Temple, Pa.) at 21° C. for 5 minutes. During the high-shear mixing, the Thickener was incrementally added. For the compositions including the Dispersant, the Dispersant was added after the abrasive particles were added and mixed, and prior to the high shear mixing. The Dispersant was added and mixed with a laboratory air mixer at 21° C. for an additional 5 minutes. Example 1 Example 1 concerns a finishing composition that includes about 6% of the fluid mixture of decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane, which are volatile cyclic siloxanes. The fluid mixture exhibits a kinematic viscosity of 5 cSt (5.0×10−6 m2/s) at 25° C. Table 2 provides the component concentrations for the finishing composition of Example 1. TABLE 2 Component Percent by Weight Deionized Water 40.59 Siloxane 1 5.99 Lubricant 1 1.90 Lubricant 2 1.20 Emulsifier 4 0.25 Abrasive 1 29.96 Abrasive 3 3.00 Thickener 1.55 Base 0.40 Solvent 1 9.99 Solvent 4 4.99 Preservative 0.19 Example 2 Example 2 concerns a finishing composition that includes about 7% of the volatile cyclic siloxane fluid. Table 3 provides the component concentrations for the finishing composition of Example 2. TABLE 3 Component Percent by Weight Deionized Water 31.75 Siloxane 1 7.00 Lubricant 1 2.00 Lubricant 2 1.00 Lubricant 4 0.25 Emulsifier 1 0.10 Abrasive 1 37.50 Abrasive 2 4.00 Thickener 0.91 Base 0.30 Solvent 1 10.00 Solvent 3 5.00 Preservative 0.19 Example 3 Example 3 concerns a finishing composition that includes hexamethyldisiloxane, which is a volatile linear siloxane that exhibits a kinematic viscosity of 0.65 cSt (6.5×10−7 m2/s) at 25° C. Table 4 provides the component concentrations for the finishing composition of Example 3. The hexamethyldisiloxane is in approximately the same concentration as the volatile cyclic siloxane provided in the finishing composition of Example 1. TABLE 4 Component Percent by Weight Deionized Water 31.75 Siloxane 2 7.00 Lubricant 1 2.00 Lubricant 2 1.00 Lubricant 4 0.25 Emulsifier 1 0.10 Abrasive 1 37.50 Abrasive 2 3.00 Thickener 1.91 Base 0.30 Solvent 1 10.00 Solvent 3 5.00 Preservative 0.19 Example 4 Example 4 concerns a finishing composition that includes about 8% of the volatile cyclic siloxane fluid. Table 5 provides the component concentrations for the finishing composition of Example 4. TABLE 5 Component Percent by Weight Deionized Water 40.01 Siloxane 1 7.95 Lubricant 3 2.98 Emulsifier 2 5.72 Abrasive 4 24.85 Thickener 1.39 Solvent 3 4.97 Solvent 5 9.94 Preservative 0.19 Dispersant 1.99 Example 5 Example 5 concerns a finishing composition that includes about 8.5% of the volatile cyclic siloxane fluid. Table 6 provides the component concentrations for the 10 finishing composition of Example 5. TABLE 6 Component Percent by Weight Deionized Water 39.49 Siloxane 1 8.41 Lubricant 1 7.01 Lubricant 2 0.93 Emulsifier 3 0.23 Abrasive 1 23.37 Abrasive 3 4.67 Thickener 1.31 Base 0.37 Solvent 4 5.61 Solvent 6 8.41 Preservative 0.18 Example 6 Example 6 concerns a finishing composition that includes about 8.75% of the volatile cyclic siloxane fluid. Table 7 provides the component concentrations for the finishing composition of Example 6. TABLE 7 Component Percent by Weight Deionized Water 25.38 Siloxane 1 8.79 Lubricant 1 1.95 Lubricant 2 0.78 Lubricant 3 1.95 Emulsifier 5 0.24 Abrasive 1 41.49 Abrasive 2 2.93 Thickener 1.37 Base 0.29 Solvent 3 5.86 Solvent 7 8.79 Preservative 0.19 Example 7 Example 7 concerns a finishing composition that includes about 3% of the 5 polydimethylsiloxane, which exhibits a kinematic viscosity of 5 cSt (5.0×10−6 m2/s) at 25° C. Table 8 provides the component concentrations for the finishing composition of Example 7. TABLE 8 Component Percent by Weight Deionized Water 43.59 Siloxane 3 3.00 Lubricant 1 1.90 Lubricant 2 1.20 Emulsifier 4 0.25 Abrasive 1 29.96 Abrasive 3 3.00 Thickener 1.55 Base 0.40 Solvent 1 9.99 Solvent 4 4.99 Preservative 0.19 Comparative Example A Comparative Example A concerns a finishing composition that does not include a volatile siloxane, but includes a total hydrocarbon solvent concentration of 19%. Table 9 provides the component concentrations for the finishing composition of Comparative Example A. TABLE 9 Component Percent by Weight Deionized Water 36.00 Lubricant 2 2.00 Lubricant 3 1.75 Emulsifier 6 0.75 Abrasive 1 37.50 Thickener 1.90 Base 0.90 Solvent 2 5.00 Solvent 4 14.00 Preservative 0.19 Comparative Example B Comparative Example B concerns a finishing composition that includes about 7% of a polydimethylsiloxane, which is a non-volatile linear siloxane that exhibits a kinematic viscosity of 10 cSt (1.0×10−5 m2/s) at 25° C. Comparative Example B also includes a total hydrocarbon solvent concentration of 15%. Table 10 provides the component concentrations for the finishing composition of Comparative Example B. TABLE 10 Component Percent by Weight Deionized Water 31.75 Siloxane 4 7.00 Lubricant 1 2.00 Lubricant 2 1.00 Lubricant 4 0.25 Emulsifier 1 0.10 Abrasive 1 37.50 Abrasive 2 3.00 Thickener 1.90 Base 0.30 Solvent 1 10.00 Solvent 3 5.00 Preservative 0.19 Comparative Example C Comparative Example C concerns a finishing that does not include a volatile siloxane, but includes a total hydrocarbon solvent concentration of 15%. Table 11 provides the component concentrations for the finishing composition of Comparative Example C. TABLE 11 Component Percent by Weight Deionized Water 38.75 Lubricant 1 2.00 Lubricant 2 1.00 Lubricant 4 0.25 Emulsifier 1 0.10 Abrasive 1 37.50 Abrasive 2 3.00 Thickener 1.90 Base 0.30 Solvent 1 10.00 Solvent 3 5.00 Preservative 0.19 Comparative Example D Comparative Example D concerns a finishing composition that does not include a volatile siloxane, but includes a total hydrocarbon solvent concentration of 22%. Table 12 provides the component concentrations for the finishing composition of Comparative Example D. TABLE 12 Component Percent by Weight Deionized Water 31.75 Lubricant 1 2.00 Lubricant 2 1.00 Lubricant 4 0.25 Emulsifier 1 0.10 Abrasive 1 37.50 Abrasive 2 3.00 Thickener 1.90 Base 0.30 Solvent 1 10.00 Solvent 2 7.00 Solvent 3 5.00 Preservative 0.19 Comparative Example E Comparative Example E concerns a finishing composition that does not include a volatile siloxane, but includes a total hydrocarbon solvent concentration of about 15%. Table 13 provides the component concentrations for the finishing composition of Comparative Example E. TABLE 13 Component Percent by Weight Deionized Water 46.46 Lubricant 1 1.89 Lubricant 2 1.20 Emulsifier 4 0.25 Abrasive 1 29.87 Abrasive 2 2.99 Thickener 1.77 Base 0.40 Solvent 1 9.99 Solvent 4 5.00 Preservative 0.19 Comparative Example F Comparative Example F concerns a finishing composition that does not include a volatile siloxane, but includes a total hydrocarbon solvent concentration of about 21%. Table 14 provides the component concentrations for the finishing composition of Comparative Example F. TABLE 14 Component Percent by Weight Deionized Water 40.46 Lubricant 1 1.89 Lubricant 2 1.20 Emulsifier 4 0.25 Abrasive 1 29.87 Abrasive 2 2.99 Thickener 1.77 Base 0.40 Solvent 1 9.99 Solvent 2 5.99 Solvent 4 5.00 Preservative 0.19 Comparative Example G Comparative Example G concerns a finishing composition that does not include a volatile siloxane, but includes a total hydrocarbon solvent concentration greater than 22%. Table 15 provides the component concentrations for the finishing composition of Comparative Example G. TABLE 15 Component Percent by Weight Deionized Water 39.84 Lubricant 3 2.97 Emulsifier 2 5.69 Abrasive 4 24.74 Thickener 1.53 Base 0.30 Solvent 2 7.92 Solvent 3 4.95 Solvent 5 9.90 Preservative 0.19 Dispersant 1.98 Comparative Example H Comparative Example H concerns a finishing composition that does not include a volatile siloxane, but includes a total hydrocarbon solvent concentration of about 15%. Table 16 provides the component concentrations for the finishing composition of Comparative Example H. TABLE 16 Component Percent by Weight Deionized Water 47.75 Lubricant 3 2.97 Emulsifier 2 5.69 Abrasive 4 24.74 Thickener 1.53 Base 0.30 Solvent 3 4.95 Solvent 5 9.90 Preservative 0.19 Dispersant 1.98 Comparative Example I Comparative Example I concerns a finishing composition that does not include a volatile siloxane, but includes a total hydrocarbon solvent concentration of about 15%. Table 17 provides the component concentrations for the finishing composition of Comparative Example I. TABLE 17 Component Percent by Weight Deionized Water 49.51 Lubricant 1 1.99 Lubricant 2 1.00 Emulsifier 3 0.25 Abrasive 1 24.93 Abrasive 2 4.99 Thickener 1.79 Base 0.40 Solvent 4 4.99 Solvent 6 9.97 Preservative 0.19 Comparative Example J Comparative Example J concerns a finishing composition that does not include a volatile siloxane, but includes a total hydrocarbon solvent concentration of about 23%. Table 18 provides the component concentrations for the finishing composition of Comparative Example J. TABLE 18 Component Percent by Weight Deionized Water 41.68 Lubricant 1 2.01 Lubricant 2 1.01 Emulsifier 3 0.25 Abrasive 1 25.17 Abrasive 2 5.03 Thickener 1.61 Base 0.40 Solvent 2 7.55 Solvent 4 5.03 Solvent 6 10.07 Preservative 0.19 Comparative Example K Comparative Example K concerns a finishing composition that includes about 7% of a polydimethylsiloxane, which is a non-volatile linear siloxane that exhibits a kinematic viscosity of 5 cSt (5.0×10−6 m2/s) at 25° C. Comparative Example K also includes a total hydrocarbon solvent concentration of about 15%. Table 19 provides the 1 5 component concentrations for the finishing composition of Comparative Example K. TABLE 19 Component Percent by Weight Deionized Water 31.74 Siloxane 3 7.00 Lubricant 1 2.00 Lubricant 2 1.00 Lubricant 4 0.25 Emulsifier 1 0.10 Abrasive 1 37.49 Abrasive 2 3.00 Thickener 1.95 Base 0.30 Solvent 1 10.00 Solvent 3 5.00 Preservative 0.19 Surface Energy Testing for Examples 2, 3, and 7 and Comparative Examples B, D, and K The finishing compositions of Examples 2, 3, and 7 and Comparative Examples B, D, and K were tested according the “Surface Energy Test” procedure described above. Table 20 provides the level of retraction and non-uniformity of paint (i.e., level of fisheye beading) for the finishing compositions of Examples 2, 3, and 7 and Comparative Examples B, D, and K. TABLE 20 Level of Retraction and Sample non-uniformity of Paint Example 2 None Example 3 None Comparative Example B Severe Comparative Example D None Comparative Example K Minor The data provided in Table 20 illustrates the benefits of incorporating volatile siloxanes in the finishing composition of the present invention. The finishing compositions of Examples 2 and 3 did not exhibit any observable fisheye beading. The 15 finishing composition of Example 2 included 7% polydimethylsiloxane with a kinematic viscosity of 0.65 cSt (6.5×10−7 m2/s) at 25° C. Similarly, the finishing composition of Example 3 included 7% of a fluid mixture of decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane, with a kinematic viscosity of 5 cSt (5.0×10−6 m2/s) at 25° C. These are volatile siloxanes, which evaporated upon application. The finishing composition of Comparative Example D also did not exhibit any fisheye beading because the composition was substantially free of siloxane materials. In contrast, the finishing compositions of Comparative Examples B and K exhibited fisheye beading. This was due to the non-volatile siloxanes contained within these finishing compositions. The finishing compositions of Comparative Example B included 7% polydimethylsiloxane with kinematic viscosity of 10 cSt (1.0×10−7 m2/s) at 25° C. The finishing compositions of Comparative Example K included 7% polydimethylsiloxane with a kinematic viscosity of 5 cSt (5.0×10−6 m2/s) at 25° C. The polydimethylsiloxanes were non-volatile siloxanes, and did not substantially evaporate upon application. Instead, they remained with the compositions, which lowered the surface energy of the test panel, and resulted in the fisheye beading. In further comparison, the finishing composition of Example 2, which included 7% of a volatile cyclic siloxane with a kinematic viscosities of 5 cSt (5.0×10−6 m2/s) at 25° C., exhibited less observable fisheye beading than the finishing compositions of Example 7 and Comparative Examples K. Working Time and Amount of Oily Residue Testing for Examples 1-7 and Comparative Examples A-K The finishing compositions of Examples 1-7 and Comparative Examples A-K were tested according the “Working Time and Amount of Oily Residue Test” procedure described above. Table 21 provides the total working time rating and the amount of oily residue rating for the finishing compositions of Examples 1-7 and Comparative Examples A-K, pursuant to the numerical scales provided in Table 1. For each finishing composition, the numerical value for the total working time rating represents the working time after all three buffing cycles. The three numerical values for the amount of oily residue rating represent the amount of oily residue after each buffing cycle. Table 21 provides the values for the amount of oily residue after each buffing cycle to further demonstrate the differences in the amounts of oily residue produced by the finishing compositions of Examples 1-7 and Comparative Examples A-K. TABLE 21 Total Working Amount of Oily Sample Time Ratings Residue Ratings Example 1 1 2, 2, 3 Example 2 1 1, 2, 2 Example 3 3 1, 2, 2 Example 4 1 2, 3, 3 Example 5 1 2, 2, 3 Example 6 1 2, 3, 3 Example 7 1 2, 3, 3 Comparative Example A 2 3, 5, 5 Comparative Example C 5 1, 1, 2 Comparative Example D 2 3, 4, 5 Comparative Example E 5 1, 1, 1 Comparative Example F 2 3, 4, 5 Comparative Example G 2 5, 5, 5 Comparative Example H 5 2, 3, 3 Comparative Example I 5 1, 1, 1 Comparative Example J 2 3, 5, 5 Comparative Example K 1 4, 5, 5 The data provided in Table 20 further illustrates the benefit of incorporating volatile siloxanes in the finishing composition of the present invention. The finishing compositions of Examples 1-7 exhibited both acceptable total working times and acceptable amounts of oily residue. The finishing compositions of Examples 1-7 included volatile siloxanes, which provided an adequate amount of time to buff out scratch marks, and also evaporated fast enough for a quick and efficient buffing. Moreover, upon evaporation, the volatile siloxanes did not leave undesirable oily residue behind. In contrast, the finishing compositions of Comparative Examples A-K exhibited either unacceptable total working times or unacceptable amounts of oily residue. In general, the finishing compositions that were free of siloxane materials and included high concentrations of volatile hydrocarbon solvents (i.e., Comparative Examples A, D, F, G, and J) exhibited acceptable total working times and unacceptable amounts of oily residue. Alternatively, the finishing compositions that were free of siloxane materials and included low concentrations of volatile hydrocarbon solvents (i.e., Comparative Examples C, E, H, I, and K) exhibited acceptable amounts of oily residue and unacceptable total working times. The finishing composition of Comparative Example B was not tested due to the severe amount of fisheye beading. This would render the finishing composition of Comparative Example B effectively unworkable. With respect to the finishing compositions of Example 7 and Comparative Example K, the data in Table 21 further illustrates the viscosity barrier between volatile and non-volatile siloxanes. The finishing composition of Comparative Example K exhibited a higher amount of oily residue compared to the finishing composition of Example 7. This result exists despite the small concentration differences, and despite the fact that both compositions incorporated polydimethylsiloxanes that exhibited kinematic viscosities of 5 cSt (5.0×10−6 m2/s) at 25° C. In comparison, the finishing compositions of Examples 1, 2, and 4-6, which included about 6% to about 8.75% of a cyclic siloxane fluid with a kinematic viscosity of 5 cSt (5.0×10−6 m2/s) at 25° C., exhibited acceptable total working times and amounts of oily residue. Additionally, the finishing composition of Example 3, which included 7% of a polydimethylsiloxane with a kinematic viscosity of 0.65 cSt (6.5×10−7 m2/s) at 25° C., and also exhibited acceptable total working times and amounts of oily residue. Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | <SOH> BACKGROUND <EOH>Finishing compositions may be used as paint refinishing materials to remove scratches left by sanding operations, which remove paint defects on vehicle surfaces. Typically when removing a paint defect, the defect is sprayed with a clearcoat and then removed using an abrasive material (e.g., sandpaper). However, this leaves visible scratch marks on the vehicle surface. The scratch marks may be removed by applying and distributing a finishing composition with abrasive buffing pads. A surface-protective sealant (seal coat) may then optionally be applied. Conventional finishing compositions contain solvents to improve the handling properties of the compositions (e.g., working time, product deposition on the surface, pick-up with a buffing pad, and clean up). These solvents evaporate after the finishing is applied to the surface. However, environmental regulations require relatively low concentrations (e.g., less than 17 percent, by weight) of volatile organic compounds (VOC) in certain products. | <SOH> SUMMARY <EOH>The present invention relates to a finishing composition that exhibits good handling properties and leaves substantially no oily residue after application. The inventive compositions can be formulated as compounds, polishes, or glazes for finishing surfaces such as painted surfaces, marine gel coats, metals, and ceramics. This finishing composition is substantially free of non-volatile silicone materials and includes a mixture of abrasive particles and an emulsion, in which the emulsion includes water, a volatile siloxane, and a lubricant. The term “non-volatile silicone material” is defined herein as a silicone having a boiling point of at least 250° C. selected from: a non-cyclic, silicone-containing material that exhibits a kinematic viscosity greater than 5 centistokes (cSt) (5.0×10 −6 m 2 /s) at 25° C.; a non-cyclic, silicone-containing material that exhibits a kinematic viscosity of 5 cSt (5.0×10 −6 m 2 /s) at 25° C. provided that the concentration of such non-cyclic silicone-containing material in the finishing composition is at least seven percent by weight; and a cyclic silicone-containing material that exhibits a kinematic viscosity greater than 7 cSt (7.0×10 −6 m 2 /s) at 25° C. The inventive finishing composition uses environmentally acceptable solvents while avoiding the use of high boiling solvents in quantities that can leave oily residue on the surface to be treated, such as a vehicle surface being repaired. The oily residue is difficult to remove from the vehicle surface and visually obscures scratch marks to be removed. With such high boiling solvents, extra time and effort are required to ensure proper repair of the paint defects. Being free of non-volatile silicone materials and oily residue, the inventive finishing yields an improvement in the appearance of painted surfaces. The invention further relates to a method of making a composition. The method includes combining a mixture of water, a volatile siloxane, a non-silicone-based lubricant, and an emulsifier to form an emulsion, the emulsifier being effective to make a stable emulsion. Abrasive particles are mixed into the emulsion to complete formation of the composition. The invention further relates to a method of treating a surface. The method includes applying a finishing composition on the surface, the finishing composition comprising water, abrasive particles, a volatile siloxane, a non-silicone-based lubricant, and an emulsifier effective to create a stable emulsion. The volatile siloxane is allowed to substantially evaporate from the surface, and leave a remaining portion of the finishing composition on the surface, said remaining portion being substantially free of oily residue. detailed-description description="Detailed Description" end="lead"? | 20040129 | 20080603 | 20050804 | 98528.0 | 1 | MARCHESCHI, MICHAEL A | FINISHING COMPOSITIONS WITH REDUCED VOLATILE ORGANIC COMPOUNDS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,767,670 | ACCEPTED | SHACKLE POCKET BUOY | A buoy for tethering a vessel has a pocket that retains a fastening device below an outer surface of the buoy to protect the vessel from contact by the fastening device. A method of manufacturing the buoy utilizes a processing line that molds elements of the buoy including the pocket. | 1. A buoy for mooring vessels comprising: a shell having an outer surface with a pocket defined therein, the pocket configured to maintain a fastening device below a plane of the outer surface in a direction of a midpoint of the buoy such that a vessel moored to the buoy is shielded from contact by the fastening device; a buoyant element retained within the shell to provide flotation and a support plate disposed in the pocket, the fastening device connected to the support plate such that an external force acting on the fastening device is diffused by the support plate. 2. The buoy as in claim 1, further comprising a tube depending through the midpoint of the buoy, the tube configured for routing a line to anchor the buoy in a body of water, the tube made from a material configured to resist wear and tear from a movement of the line resulting from a motion of the body of water, a motion of the vessel or combinations thereof. 3. The buoy as in claim 1, wherein the buoyant element is one of a polystyrene material, a polyurethane foam, a cork, or a gas. 4. The buoy as in claim 1, wherein the shell is made of a material selected from the group consisting of a polyethylene, a polyvinyl chloride, a rubber, a fiberglass, a nylon, an acetal plastic, a polypropylene, and a polyetheretherketone. 5. The buoy as in claim 4, wherein the shell is made from polyethylene and the polyethylene is a high-density polyethylene. 6. The buoy as in claim 1, wherein the shell is ball-shaped, can-shaped, cone-shaped, or drum-shaped. 7. The buoy as in claim 1, wherein the pocket defines a wall depending downwardly in a direction of the midpoint. 8. The buoy as in claim 7, wherein the wall is bowl-shaped and depends from about 25 degrees to about 75 degrees from a centerline of the buoy. 9. The buoy as in claim 1, wherein the pocket is or funnel-shaped. 10. The buoy as in claim 1, wherein the fastening device is a shackle. 11. The buoy as in claim 1, wherein the fastening device is configured to swivel about a centerline of the buoy. 12. The buoy as in claim 1, further comprising an annular lip formed on the outer surface of the shell proximate the pocket, the annular lip configured to increase a depth of the pocket to further shield the fastening device within the pocket. 13. (canceled) 14. The buoy as in claim 1, wherein the pocket defines a support plate pocket therein, the support plate pocket shaped complementary to the support plate to house the support plate. 15. The buoy as in claim 1, further comprising a ballast configured to affect a buoy characteristic. 16. The buoy as in claim 15, wherein the characteristic is upright stability, or counterweight. 17. The buoy as in claim 1, further comprising a line to anchor the buoy in the body of water. 18. A mooring device for a buoy comprising: a shackle for attaching a mooring line from a vessel; a pocket defined in a surface of a buoy to retain the shackle below the surface in a direction of a midpoint of the buoy such that a hull of the vessel moored to the buoy is shielded from contact by the shackle; a protrusion disposed proximate the pocket depending from the surface of the buoy in a direction away from the midpoint, the protrusion configured to increase a size of the pocket such that the shackle is further removed from the surface of the buoy, the protrusion further configured to make contact with the vessel in lieu of the shackle; and a support plate disposed in the pocket, the support plate connected to the shackle and to an anchor chain for anchoring the buoy in a body of water. 19. The mooring device as in claim 18, wherein the shackle is configured to swivel about a centerline of the buoy. 20. The mooring device as in claim 18, wherein a distal end of the shackle terminates beneath an outermost edge of the protrusion. 21. The mooring device as in claim 18, wherein the pocket is bowl-shaped, or funnel-shaped. 22. The mooring device as in claim 18, wherein the surface of the buoy is made of a material selected from the group consisting of a polypropylene, a polyethylene, a polyvinyl chloride, a rubber, a fiberglass, a wood and combinations thereof. 23. The mooring device as in claim 18, wherein the protrusion is a collar affixed to the surface. 24. The mooring device as in claim 18, further comprising a buoyant element disposed beneath the surface of the buoy, the buoyant element selected from the group consisting of a polystyrene material, a polyurethane foam, a cork, a gas, and combinations thereof. 25. (canceled) 26. The mooring device as in claim 18, wherein the pocket defines a support plate pocket therein, the support plate pocket shaped complementary to the support plate to house the support plate. 27. A method of manufacturing a buoy, comprising the steps of: forming a shell defining a shackle pocket therein; bonding a tube within the shell; inserting a buoyant element into the shell and about the tube; attaching a shackle within the shackle pocket such that the shackle is disposed beneath a surface of the shell; and attaching a support plate in the shackle pocket, the shackle attached to the support plate. 28. The method as in claim 27, wherein the shell is formed by rotational molding, blow molding, or injection molding. 29. The method as in claim 27, further comprising the steps of forming the buoyant element, placing the formed buoyant element about the tube, and forming the shell about the buoyant element and tube for encapsulation by the shell. 30. The method as in claim 27, further comprising the step of injecting the buoyant element into the formed shell. 31. The method as in claim 30, further comprising the step of hardening the buoyant element about the tube in the formed shell. 32. (canceled) 33. The method as in claim 27, further comprising the step of attaching an anchor chain, a dead weight, an anchor or combinations thereof to the buoy. 34. The method as in claim 27, further comprising the step of adding ballast to the buoy. 35. The method as in claim 27, further comprising the step of forming a lip on the shell proximate the shackle pocket, the lip configured to shield a vessel from the shackle. 36. The method as in claim 27, further comprising the step of attaching a lip on the shell proximate the shackle pocket after formation of the shell, the lip configured to shield a vessel from the shackle. 37. A processing line for manufacturing a mooring buoy according to claim 1, the processing line comprising: means for forming a buoy shell defining a shackle pocket therein; means for bonding a tube within the buoy shell; means for inserting a buoyant element into the shell and about the tube; and means for attaching a shackle within the shackle pocket such that the shackle is disposed beneath a surface of the buoy shell. 38. A buoy for mooring vessels comprising: a shell having an outer surface with a pocket defined therein, the pocket configured to maintain a fastening device below a plane of the outer surface in a direction of a midpoint of the buoy such that a vessel moored to the buoy is shielded from contact by the fastening device; a buoyant element retained within the shell to provide flotation; and a support plate disposed in the pocket, the fastening device and the line connected to the support plate such that an external force acting on the fastening device or the line is diffused by the support plate. | FIELD OF THE INVENTION This invention relates to buoys. More specifically, the invention is directed to a buoy having a pocket in which a tethering device is retained to prevent its contact and damage to a vessel tethered to the buoy. BACKGROUND OF THE INVENTION Mooring buoys are well known for mooring a vessel in open water without having to dock the vessel pierside. One drawback of the typical mooring buoy is its exposed shackle, which can contact a vessel hull due to wave action and other forces acting on the vessel and the buoy. Contact between the vessel hull and the conventional buoy mars the vessel hull and in some cases, may cause significant damage and affect the vessel's seaworthiness. A mooring buoy is needed that safeguards vessel hulls from contact by exposed shackles and the associated damage caused by such contact. BRIEF SUMMARY OF THE INVENTION The present invention provides a buoy having a shackle pocket in which the shackle is recessed beneath a plane of an outer surface of the buoy to protect a vessel moored to the buoy from exposure to the shackle. The component parts of the buoy are simple and economical to manufacture, assemble, and use. Other advantages of the invention will be apparent from the following description and the attached drawings or can be learned through practice of the invention. According to one aspect of the invention, a buoy for mooring vessels is provided with a shell having an outer surface with a pocket defined therein. The pocket is formed to maintain a fastening device below a plane of the outer surface in a direction of a midpoint of the buoy such that a vessel moored to the buoy is shielded from contact by the fastening device. A buoyant element is retained within the shell to provide flotation for the buoy. In another aspect of the invention, a mooring device for a buoy is provided having a shackle for attaching a mooring line from a vessel; a pocket defined in a surface of a buoy to retain the shackle below the surface in a direction of a midpoint of the buoy such that a hull of the vessel moored to the buoy is shielded from contact by the shackle; and a protrusion disposed proximate the pocket depending from the surface of the buoy in a direction away from the midpoint, the protrusion configured to increase a size of the pocket such that the shackle is further removed from the surface of the buoy, the protrusion further configured to make contact with the vessel in lieu of the shackle. Other aspects and advantages of the invention will be apparent from the following description and the attached drawings, or can be learned through practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The above and other aspects and advantages of the present invention are apparent from the detailed description below and in combination with the drawings in which: FIG. 1 is a perspective view of one embodiment of a mooring buoy in accordance with the present invention; FIG. 2a shows a conventional buoy and particularly, damage to a vessel hull caused by an exposed shackle; FIG. 2b shows a buoy similar to FIG. 1; FIG. 3 is a cross sectional view of a buoy similar to FIGS. 1 and 2b and including a ballast device; and FIG. 4 is a schematic view of an embodiment of a processing line for performing a method of manufacturing a buoy as in FIG. 1. DETAILED DESCRIPTION OF THE DRAWINGS Detailed reference will now be made to the drawings in which examples embodying the present invention are shown. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention. The drawings and detailed description provide a full and detailed written description of the invention, and of the manner and process of making and using it, so as to enable one skilled in the pertinent art to make and use it, as well as the best mode of carrying out the invention. However, the examples set forth in the drawings and detailed description are provided by way of explanation of the invention and are not meant as limitations of the invention. The present invention thus includes any modifications and variations of the following examples as come within the scope of the appended claims and their equivalents. As broadly embodied in FIGS. 1, 2b and 3, a buoy, generally designated by the number 10, is shown with a shackle pocket 20 in which a mooring or fastening device such as a shackle 30 is embedded to protect a vessel hull from contact and damage by the shackle 30. As described in detail below, the components of the buoy 10, their placement and dimensions are modifiable to accommodate various vessel and anchor line sizes and manufacturing requirements and are not limited to only those examples shown in the Figures. For instance, although the buoy 10 is shown generally ball-shaped, any shape such as can-shaped, box-shaped, pyramid-shaped, nun-buoy (cone) shaped, drum-shaped, or combinations of these and other shapes are within the scope of the present invention. Additionally, the buoy 10 can be sized to meet any manufacturing or customer requirement such as by adjusting its diameter (from about 12 inches to about 32 inches) and its weight (from about 25 pounds to about 530 pounds). With particular reference to FIG. 1, the buoy 10 generally includes a shell 12 in which the shackle pocket 20 is formed and in which the shackle 30 is attached. The shackle pocket 20 defines a support plate pocket 22 and a bowl-shaped wall 24. A protrusion or annular lip 26 is formed about the shackle pocket 20 in this example. Also, a complementarily shaped support plate 28 is seated in the support plate pocket 22 to protect other components of the buoy 10 from external forces. For instance, a line 32 from a vessel V (see, e.g., FIG. 2b) is attached to the shackle 30, which is attached to the support plate 28. An anchor chain 34 is also attached to the support plate 28. Described by example operation below, as the line 32 and the anchor chain 34 move due to external forces, they act on the support plate 28 rather than other components of the buoy 10. The shell 12 in FIG. 1 is made of made of any impact- and weather-resistant material such as polyethylene, more particularly, high-density polyethylene (HDPE), or polypropylene, polyvinyl chloride, rubber, fiberglass, nylon, POM (polyoxymethylene; i.e., acetal plastic), PEEK (polyetheretherketone), or any natural (e.g., wood) or synthetic materials or their combinations suitable for flotation on a body of water. In one aspect of the invention, the shell 12 has a wall thickness of about 3/16 of an inch, although other wall thicknesses can be made to meet specific requirements. A method of producing the buoy 10 including the shell 12 is described in detail below. The shackle 30 in FIG. 1 is swivelably attached to the support plate 28 to permit the vessel V (FIG. 2b) freedom to swing about the buoy 10 as wind and current change. The shackle 30 can be any fixed or swivelable fastening device such as a link of chain, a D-shaped ring, an O-shaped ring, a clasp, a hook and eye apparatus, or combinations of these and other devices suitable for attaching the line 32. Turning to FIG. 2a, a conventional mooring buoy Bc is shown with a typical ring-type shackle Sc projecting from the mooring buoy Bc. Due to wave action and other external forces on one or both of a tethered vessel Vc and the mooring buoy Bc, the exposed shackle Sc repeatedly strikes a hull Hc of the vessel Vc causing scratches and dents at area D. With repeated exposure and sufficient force, the shackle Sc can compromise the vessel hull Hc and adversely affect seaworthiness of the vessel Vc. FIG. 2b shows the unique shackle pocket 20 in operation. In this example, the vessel V is moored to the buoy 10 by attaching the line 32, which can be a chain, a rope, a cable, a line or similar rigging. The buoy 10 itself is anchored in an area of water by the anchor chain 34, which also can be a rope, cable, line or the like. As shown, the shackle 30 is safely recessed within the shackle pocket 20 in contrast to the conventional mooring buoy Bc and its exposed shackle Sc. Thus, the shackle 30 does not contact a hull H of the vessel V due to wave or wind action or movement of the vessel V or varying aspect angles of the buoy 10 and the vessel V relative to each other. FIG. 3 shows a detailed cross-section of the buoy 10. The shell 12 encapsulates a buoyant element 14, which is an expanded polystyrene fill material in this example. As known, polystyrene is a polymer of styrene, and expanded polystyrene appears as a rigid white foam often used as packing or insulation material. A suitable expanded polystyrene fill material is available from Huntsman Chemical Corporation headquartered in Houston, Tex. Other materials or elements that are lighter than water are also suitable to provide flotation to the buoy 10. For instance, polyurethane foam, cork, a gas such as helium, or combinations of these elements can be substituted for polystyrene. FIG. 3 further shows a ballast 62, which is attached to or added in the buoy 10 to positively affect a characteristic of the buoy 10. For instance, by adding weight (i.e., counterweights) in the form of the ballast 62 in specific regions of the buoy 10, above-water exposure of the buoy 10 can be controlled. Also, upright stability of the buoy 10 can be ensured to maintain an aspect of the shackle pocket 20 relative to a horizontal plane; i.e., to maintain a centerline CL of the buoy 10, e.g., +/−30 degrees of the horizontal plane for 360 degrees of rotation. Alternatively stated, the ballast 62 can be utilized to control bobbing, rolling, and drifting behaviors of the buoy 10. Also shown in FIG. 3, a passage or core 16 is coaxially aligned with the centerline CL of the buoy 10. The core 16 has a first opening 16a and a second opening 16b and passes through a midpoint M of the buoy 10. A pipe or tube 18 inserted in the core 16 and is therefore also coaxially aligned with the centerline CL and passes through the midpoint M. The tube 18 defines a first end 18a and a second end 18b, which respectively lie in co-circumferential relationship with the first and second openings 16a, 16b of the core 16. In one aspect of the invention, an inner diameter of the tube 18 is about 1½-3 inches but can be sized to accommodate various sizes of anchor chain 34. Similarly, a length of the tube 18 can be varied in accordance with a size of the buoy 10. The tube 18 is made from any material such as a hardened plastic (having a thickness of at least about 1/4 inch polyethylene), a metal, or another suitably hard material made to resist wear and tear by the anchor chain 34 as the anchor chain 34 moves within the tube 18 due to wave or wind action, a motion of the vessel V, or combinations of these external forces. Further description of the tube 18 and its attachment and interaction with the support plate 28 are discussed below. FIG. 3 also shows the shackle pocket 20 recessed in a surface 12a of the shell 12 and centered about the centerline CL. As briefly introduced above, the support plate 28 is seated in the support plate pocket 22 of the shackle pocket 20. The support plate 28 is secured to the support plate pocket 22 such as by press-fitting or molding, or by adhesives, screws, rivets, bolts, and similar mechanical attachments. The first end 18a of the tube 18 is attached to the support plate 28 on one side 28a such as by welding or appropriate mechanical attachment. The shackle 30 is attached to an opposing side 28b of the support plate 28 by adhesives, screws, rivets, bolts, and similar mechanical attachments. In this manner, as the anchor chain 34 (see, e.g., FIG. 2b) moves within the tube 18 due to the external forces noted above, the support plate 28 receives and diffuses the forces, which protects other components of the buoy 10 such as the buoyant element 14. Also shown in FIG. 3, the shackle pocket 20 defines the bowl-shaped wall 24 briefly introduced above. The wall 24 is annular and slopes downwardly in a direction of the midpoint M in this example. A slope of the wall 24 from about 25 degrees to about 75 degrees relative to the centerline CL effectively recesses the shackle 30 for protection of the vessel hull H. Other angles or slopes of the bowl-shaped wall 24 can also be provided. It will be further appreciated that the exemplary pocket 20 can be other than bowl-shaped, such as a box-shape, a pyramid-shape, a funnel-shape or combinations of these and other shapes. FIG. 3 further shows an annular protrusion or lip 26 formed on the outer surface 12a of the shell 12 near the pocket 20. As shown, the lip 26 depends from the surface 12a in a direction away from the midpoint M approximately ½ inch to about 6 inches from the surface 12a. Various sizes and shapes of the lip 26 can be provided to accommodate manufacturing or customer requirements. For example, the annular lip 26 can be a series of raised bumps or the like. Alternatively, the annular lip 26 can be a collar device made for permanent affixation to the buoy 10 after the buoy 10 is formed. Further, the collar can be detachable for subsequent attachment to or detachment from the buoy 10. As shown, the annular lip 26 virtually increases a depth or length L of the pocket 20 relative to the surface 12a to further shield the shackle 30 within the pocket 20. Specifically, the lip 26 serves to limit an extent of a distal end 30a of the shackle 30 since the length L of the pocket 20 from proximate the plate pocket 22 at the centerline CL to an outermost edge of the lip 26 is greater than the extent of the distal end 30a. Thus, the distal end 30a terminates short of the outermost edge of the lip 26; i.e., within the pocket 20. However, even without the lip 26, the pocket 20 is sufficiently deep to terminate the distal end 30a of the shackle 30 below the surface 12a of the shell 12. Alternatively stated, if the shell 12 covered the pocket 20, the distal end 30a would also be covered. Accordingly, with further reference to FIG. 2b, the lip 26 will make contact with the vessel V instead of the shackle 30 in the event the buoy 10 pitches toward the vessel V in a manner that directs the pocket 20 toward the vessel V. Turning to FIG. 4, a method of manufacturing the buoy 10 as in FIG. 3 is provided in another aspect of the invention. A processing line 50 is used to practice the method. The method includes the steps of forming the shell 12 to include the shackle pocket 20 and optionally, the lip 26; bonding the tube 18 into the shell 12; injecting or inserting the buoyant element 14 into the shell 12 and about the tube 18; and attaching the support plate 28, the shackle 30, the anchor chain 34, and/or a dead weight or anchor 36. The step of forming the shell 12 is performed by rotational molding (rotomolding), injection molding, blow molding or the like. By way of example, the rotomolding process starts with a quality cast or fabricated mold 52 as schematically shown in FIG. 4. The mold 52 is placed in a rotomolding machine 54 that has a loading area 50a, a heating area 50b, a cooling area 50c, and a finishing or staging area 50d. Pre-measured plastic resin 56 such as HDPE is loaded into the mold 52 in the loading area 50a. The mold 52 is moved into an oven 58 in the heating area 50b where it is slowly rotated on both vertical and horizontal axes as indicated by the rotating axes symbol R. The melting resin 56 sticks to the hot mold 52 and evenly coats every surface of the mold 52 unless otherwise required, e.g., to form various wall thicknesses. Lastly, the rotomolded shell 12 is moved to the cooling area 50c where it is cooled and released from the mold 52 and sent to the staging or finishing area 50d. Rotational speed, heating and cooling times are all controlled throughout the foregoing process and each can be adjusted to modify characteristics of the shell 12, such as its wall thickness. As noted above, the shell 12 can have differing wall thicknesses in particular sections, for instance, about 3/16 of an inch of HDPE at upper and lower sections of the buoy 10 and about ½ of an inch HDPE in a middle section of the buoy 10. Further, although rotomolding the shell 12 has been described by way of example, the shell 12 can be otherwise formed using other steps and materials; for example, by blow molding polypropylene. The step of bonding the tube 18 into the shell 12 can be performed when the resin 56 is loaded into the mold 52, or after the shell 12 is released from the mold 52. Similarly, the buoyant element 14, described in detail above, can be preformed and placed about the tube 18 for subsequent encapsulation by the shell 12, or injected as a foam for hardening about the tube 18, or as a gas following formation of the shell 12. Another step in the exemplary method is to affix the lip 26 in the form of a collar device if the lip 26 was not unitarily formed with the shell 12. Also, the shell 12 can be colored during its formation or subsequently painted, and/or customized graphics or color schemes 60 can be applied. The ballast 62 can also be added prior to insertion of the buoyant element 14 or thereafter. Additionally, an underwater float 64 can be attached to the anchor chain 34, for instance, to locate the chain 34. While preferred embodiments of the invention have been shown and described, those skilled in the art will recognize that other changes and modifications may be made to the foregoing embodiments without departing from the scope and spirit of the invention. For example, specific buoy sizes and dimensions and specific shapes of various elements of the illustrated embodiments may be altered to suit particular applications. It is intended to claim all such changes and modifications as fall within the scope of the appended claims and their equivalents. Moreover, references herein to “top,” “lower,” “bottom,” “upward,” “downward,” “upright”, and “side” structures, elements and geometries and the like are intended solely for purposes of providing an enabling disclosure and in no way suggest limitations regarding the operative orientation of the exemplary embodiments or any components thereof. | <SOH> BACKGROUND OF THE INVENTION <EOH>Mooring buoys are well known for mooring a vessel in open water without having to dock the vessel pierside. One drawback of the typical mooring buoy is its exposed shackle, which can contact a vessel hull due to wave action and other forces acting on the vessel and the buoy. Contact between the vessel hull and the conventional buoy mars the vessel hull and in some cases, may cause significant damage and affect the vessel's seaworthiness. A mooring buoy is needed that safeguards vessel hulls from contact by exposed shackles and the associated damage caused by such contact. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention provides a buoy having a shackle pocket in which the shackle is recessed beneath a plane of an outer surface of the buoy to protect a vessel moored to the buoy from exposure to the shackle. The component parts of the buoy are simple and economical to manufacture, assemble, and use. Other advantages of the invention will be apparent from the following description and the attached drawings or can be learned through practice of the invention. According to one aspect of the invention, a buoy for mooring vessels is provided with a shell having an outer surface with a pocket defined therein. The pocket is formed to maintain a fastening device below a plane of the outer surface in a direction of a midpoint of the buoy such that a vessel moored to the buoy is shielded from contact by the fastening device. A buoyant element is retained within the shell to provide flotation for the buoy. In another aspect of the invention, a mooring device for a buoy is provided having a shackle for attaching a mooring line from a vessel; a pocket defined in a surface of a buoy to retain the shackle below the surface in a direction of a midpoint of the buoy such that a hull of the vessel moored to the buoy is shielded from contact by the shackle; and a protrusion disposed proximate the pocket depending from the surface of the buoy in a direction away from the midpoint, the protrusion configured to increase a size of the pocket such that the shackle is further removed from the surface of the buoy, the protrusion further configured to make contact with the vessel in lieu of the shackle. Other aspects and advantages of the invention will be apparent from the following description and the attached drawings, or can be learned through practice of the invention. | 20040129 | 20051018 | 20050804 | 96021.0 | 1 | SWINEHART, EDWIN L | SHACKLE POCKET BUOY | SMALL | 0 | ACCEPTED | 2,004 |
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10,767,692 | ACCEPTED | Selection of neurostimulator parameter configurations using genetic algorithms | In general, the invention is directed to a technique for selection of parameter configurations for a neurostimulator using genetic algorithms. The technique may be employed by a programming device to allow a clinician to select parameter configurations, and then program an implantable neurostimulator to deliver therapy using the selected parameter configurations. In operation, the programming device executes an electrode configuration search algorithm to guide the clinician in the selection of electrode configurations. The search algorithm relies on a genetic algorithms to identify potential optimum electrode configurations within an electrode set. The genetic algorithms provide guidance in the electrode configuration selections process, interactively guiding the clinician by suggesting the configurations that are most likely to be efficacious given the results of tests already performed during an evaluation session. | 1. A method comprising: selecting a first parameter configuration for a neurostimulator; receiving an indication of observed efficacy of the first parameter configuration; and selecting a second parameter configuration for the neurostimulator based on the indication of observed efficacy and a genetic algorithm. 2. The method of claim 1, wherein the parameter configurations include electrode configurations, each of the electrode configurations defining a combination of two or more electrodes for delivery of neurostimulation energy. 3. The method of claim 2, wherein each of the electrode configurations defines polarities for electrodes in the combination. 4. The method of claim 2, wherein the electrodes are carried by two or more implanted leads. 5. The method of claim 4, wherein the electrodes are associated with different target regions within a body of a patient. 6. The method of claim 4, wherein the leads are implanted proximate a spine of a patient. 7. The method of claim 2, further comprising iteratively selecting additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the genetic algorithm. 8. The method of claim 7, further comprising terminating the iterative selection of the additional electrode configurations when one or more termination criteria are satisfied. 9. The method of claim 8, wherein the termination criteria include selection of one of the electrode configurations with an observed efficacy that satisfies a threshold efficacy. 10. The method of claim 2, further comprising: iteratively selecting additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the genetic algorithm; terminating the iterative selection of the additional electrode configurations at a final electrode configuration when one or more termination criteria are satisfied; and programming the neurostimulator to employ the final electrode configuration in delivery of neurostimulation therapy. 11. The method of claim 10, wherein the neurostimulator is a spinal cord stimulator, and the final electrode configuration includes electrodes deployed on one more implanted spinal leads. 12. The method of claim 11, wherein the final electrode configuration defines a combination of two electrodes from a set of at least eight electrodes. 13. The method of claim 1, wherein selecting the first and second parameter configurations includes suggesting the first and second parameter configurations to a clinician. 14. The method of claim 1, wherein receiving an indication relating to observed efficacy includes receiving user input indicating observed efficacy. 15. The method of claim 1, further comprising updating the genetic algorithm based on the observed efficacy. 16. The method of claim 15, wherein updating the genetic algorithm comprises performing at least one of cross-over between different solutions identified by the genetic algorithm and mutation of one or more solutions identified by the genetic algorithm. 17. The method of claim 16, wherein the genetic algorithm identifies solutions associated with the first and second parameter configurations, and updating the genetic algorithm includes generating one or more successive generations of the solutions. 18. The method of claim 16, wherein cross-over includes swapping electrodes between different solutions. 19. The method of claim 16, wherein mutation includes introducing random electrode changes in different solutions. 20. A computer-readable medium comprising instructions to cause a processor to: select a first parameter configuration for a neurostimulator; receive an indication of observed efficacy of the first parameter configuration; and select a second parameter configuration for the neurostimulator based on the indication of observed efficacy and a genetic algorithm. 21. The computer-readable medium of claim 20, wherein the parameter configurations include electrode configurations, each of the electrode configurations defining a combination of two or more electrodes for delivery of neurostimulation energy. 22. The computer-readable medium of claim 21, wherein each of the electrode configurations defines polarities for electrodes in the combination. 23. The computer-readable medium of claim 21, wherein the electrodes are carried by two or more implanted leads. 24. The computer-readable medium of claim 23, wherein the electrodes are associated with different target regions within a body of a patient. 25. The computer-readable medium of claim 23, wherein the leads are implanted proximate a spine of a patient. 26. The computer-readable medium of claim 21, further comprising instructions to cause the processor to iteratively select additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the genetic algorithm. 27. The computer-readable medium of claim 26, further comprising instructions to cause the processor to terminate the iterative selection of the additional electrode configurations when one or more termination criteria are satisfied. 28. The computer-readable medium of claim 27, wherein the termination criteria include selection of one of the electrode configurations with an observed efficacy that satisfies a threshold efficacy. 29. The computer-readable medium of claim 21, further comprising instructions to cause the processor to: iteratively select additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the genetic algorithm; terminate the iterative selection of the additional electrode configurations at a final electrode configuration when one or more termination criteria are satisfied; and program the neurostimulator to employ the final electrode configuration in delivery of neurostimulation therapy. 30. The computer-readable medium of claim 29, wherein the neurostimulator is a spinal cord stimulator, and the final electrode configuration includes electrodes deployed on one more implanted spinal leads. 31. The computer-readable medium of claim 30, wherein the final electrode configuration defines a combination of two electrodes from a set of at least eight electrodes. 32. The computer-readable medium of claim 20, wherein the instructions cause the processor to suggest the first and second parameter configurations to a clinician. 33. The computer-readable medium of claim 20, wherein the instructions to cause the processor to receive an indication relating to observed efficacy include instructions to cause the processor to receive user input indicating observed efficacy. 34. The computer-readable medium of claim 20, further comprising updating the genetic algorithm based on the observed efficacy. 35. The computer-readable medium of claim 34, wherein updating the genetic algorithm comprises performing at least one of cross-over between different solutions identified by the genetic algorithm and mutation of one or more solutions identified by the genetic algorithm. 36. The computer-readable medium of claim 35, wherein the genetic algorithm identifies solutions associated with the first and second parameter configurations, and updating the genetic algorithm includes generating one or more successive generations of the solutions. 37. The computer-readable medium of claim 35, wherein cross-over includes swapping electrodes between different solutions. 38. The computer-readable medium of claim 35, wherein mutation includes introducing random electrode changes in different solutions. 39. A device comprising a processor programmed to: select a first parameter configuration for a neurostimulator; receive an indication of observed efficacy of the first parameter configuration; and select a second parameter configuration for the neurostimulator based on the indication of observed efficacy and a genetic algorithm. 40. The device of claim 39, wherein the parameter configurations include electrode configurations, each of the electrode configurations defining a combination of two or more electrodes for delivery of neurostimulation energy. 41. The device of claim 40, wherein each of the electrode configurations defines polarities for electrodes in the combination. 42. The device of claim 40, wherein the electrodes are carried by two or more implanted leads. 43. The device of claim 42, wherein the electrodes are associated with different target regions within a body of a patient. 44. The device of claim 42, wherein the leads are implanted proximate a spine of a patient. 45. The device of claim 40, wherein the processor iteratively selects additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the genetic algorithm. 46. The device of claim 45, wherein the processor terminates the iterative selection of the additional electrode configurations when one or more termination criteria are satisfied. 47. The device of claim 46, wherein the termination criteria include selection of one of the electrode configurations with an observed efficacy that satisfies a threshold efficacy. 48. The device of claim 40, wherein the processor: iteratively selects additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the genetic algorithm; terminates the iterative selection of the additional electrode configurations at a final electrode configuration when one or more termination criteria are satisfied; and programs the neurostimulator to employ the final electrode configuration in delivery of neurostimulation therapy. 49. The device of claim 48, wherein the neurostimulator is a spinal cord stimulator, and the final electrode configuration includes electrodes deployed on one more implanted spinal leads. 50. The device of claim 49, wherein the final electrode configuration defines a combination of two electrodes from a set of at least eight electrodes. 51. The device of claim 39, wherein the processor generates a suggestion of the first and second parameter configurations to a clinician. 52. The device of claim 39, wherein the processor receives user input indicating observed efficacy. 53. The device of claim 39, wherein the processor updates the genetic algorithm based on the observed efficacy. 54. The device of claim 53, wherein the processor updates the genetic algorithm by performing at least one of cross-over between different solutions identified by the genetic algorithm and mutation of one or more solutions identified by the genetic algorithm. 55. The device of claim 54, wherein the genetic algorithm identifies solutions associated with the first and second parameter configurations, and the processor updates the genetic algorithm by generating one or more successive generations of the solutions. 56. The device of claim 54, wherein cross-over includes swapping electrodes between different solutions. 57. The device of claim 54, wherein mutation includes introducing random electrode changes in different solutions. | This application claims the benefit of U.S. provisional application Ser. No. 60/503,208, filed Sep. 15, 2003, the entire content of which is incorporated herein by reference. TECHNICAL FIELD The invention relates to neurostimulation therapy and, more particularly, to techniques for selection of configurations for an implantable neurostimulator. BACKGROUND Implantable medical devices are used to deliver neurostimulation therapy to patients to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson's disease, epilepsy, incontinence, sexual dysfunction, or gastroparesis. The implantable medical device delivers neurostimulation therapy via one or more leads that include electrodes located proximate to the spinal cord, pelvic nerves, sacrum, or stomach, or within the brain of a patient. In general, the implantable medical device delivers neurostimulation therapy in the form of electrical pulses. A clinician selects values for a number of programmable parameters in order to define a parameter configuration for the neurostimulation therapy to be delivered to a patient. For example, the clinician may select an amplitude, which may be a current or voltage amplitude, and pulse width for a stimulation waveform to be delivered to the patient, as well as a rate at which the pulses are to be delivered to the patient, and duration for which the stimulation energy is delivered. In addition, the clinician also selects particular electrodes within an electrode set to be used to deliver the pulses, and the polarities of the selected electrodes. The electrode combinations and polarities may be referred to as an electrode configuration. Hence, a parameter configuration may involve a variety of parameters including electrode configuration, amplitude, pulse width, pulse rate, and duration. The process of selecting parameter configurations can be time consuming, and may require a great deal of trial and error before an optimum electrode configuration is discovered. The optimum parameter configuration may be better than other configurations in balancing clinical results and side effects experienced by the patient. This balance represents overall efficacy of a parameter configuration. The process for selecting parameter configurations can be difficult due to the combinatorial possibilities of parameters, the complexity of the underlying biophysics, and subjective and possibly inconsistent feedback from the patient concerning observed efficacy for a given parameter configuration. SUMMARY In general, the invention is directed to a technique for selection of parameter configurations for a neurostimulator using genetic algorithms. The technique may be employed by a programming device to allow a clinician to select parameter configurations, and then program an implantable neurostimulator to deliver therapy using the selected parameter configurations. A parameter configuration may define one or more parameters for delivery of neurostimulation, such as electrode configuration, amplitude, pulse width, pulse rate, or duration. For example, the parameter configurations may define electrode configurations that specify electrode combinations and polarities for an electrode set implanted in a patient. The electrode set may be carried by one or more implanted leads that are electrically coupled to the neurostimulator. In some embodiments, the parameter configurations may further define one or more parameters such as amplitudes, pulse widths, pulse rates, and durations of stimulation energy delivered by electrodes in the electrode configuration. In operation, the programming device executes a parameter configuration search algorithm to guide the clinician in the selection of parameter configurations. The search algorithm relies on genetic algorithms to identify potential optimum parameter configurations, such as electrode configurations within an electrode set. The genetic algorithms provide guidance in the electrode configuration selections process, interactively guiding the clinician by suggesting the configurations that are most likely to be efficacious given the results of tests already performed during an evaluation session. Genetic algorithms encode potential solutions to a problem as members of a population of solutions. This population is then judged based on a fitness function. The best performers, i.e., the most fit solutions, are then retained and a new generation is created based upon their characteristics. The new generation is composed of solutions similar in nature to the best performers of the previous generation. This process of creation can use one or more techniques for generating new solutions. These techniques include cross-over, i.e., sharing of parts of a solution from one member to another, and mutation, i.e., random changes within a solution from one generation to the next. Hence, the genetic algorithm identifies solutions associated with the different parameter configurations, and updates the genetic algorithm by generating one or more successive generations of the solutions, e.g., by cross-over or mutation. These techniques can be applied to the problem of parameter optimization, including selection of electrode configurations. Each potential solution, such as a parameter or electrode configuration, can be encoded as one member of the population. As an example, one solution might encode values for amplitude, rate, pulse width, and electrode combination of a stimulation device therapy. The fitness function used for selection then becomes the subjective efficacy rating assigned by the patient when the clinician tries the solution during a session. After some number of ratings are collected, the system ‘kills’ off the least fit, generates a new population based upon the more fit, and continues the cycle. This repeats until a satisfactory solution is discovered, or “evolved.” In one embodiment, the invention provides a method comprising selecting a first parameter configuration for a neurostimulator, receiving an indication of observed efficacy of the first parameter configuration, and selecting a second parameter configuration for the neurostimulator based on the indication of observed efficacy and a genetic algorithm. In another embodiment, the invention provides a computer-readable medium comprising instructions to cause a processor to select a first parameter configuration for a neurostimulator, receive an indication of observed efficacy of the first parameter configuration, and select a second parameter configuration for the neurostimulator based on the indication of observed efficacy and a genetic algorithm. In a further embodiment, the invention provides a device comprising a processor programmed to select a first parameter configuration for a neurostimulator, receive an indication of observed efficacy of the first parameter configuration, and select a second parameter configuration for the neurostimulator based on the indication of observed efficacy and a genetic algorithm. The invention may provide a number of advantages. For example, the invention may allow a clinician to more quickly identify desirable parameter configurations such as electrode combinations, reducing the overall amount of time the clinician spends programming neurostimulation therapy for a patient. In contrast to random or idiosyncratic search techniques, a technique based on genetic algorithms is capable of learning from the evaluation of earlier parameter configurations, and developing a series of algorithms that lead to an optimum configuration. In general, the invention can reduce the length of a programming session for the clinician and the patient, and support selection of optimum electrode configurations to achieve overall efficacy. In addition, with the invention, it may be possible to identify optimal or near optimal parameter configurations that otherwise might not be identified by the clinician. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram illustrating a system for programming and delivering neurostimulation therapy. FIG. 2 is a diagram illustrating an example electrode set implanted proximate to the spine of a patient. FIG. 3 is a block diagram illustrating a programming device used to identify desirable parameter configurations for neurostimulation therapy programs. FIG. 4 is a flow diagram illustrating application of genetic algorithms to select electrode configurations. DETAILED DESCRIPTION FIG. 1 is a diagram illustrating an example system 10 for programming neurostimulation therapy for and delivering neurostimulation therapy to a patient 12. System 10 includes an implantable medical device (IMD) 14 that delivers neurostimulation therapy to patient 12. IMD 14 may be an implantable pulse generator, and may deliver neurostimulation therapy to patient 12 in the form of electrical pulses. System 10 makes use of genetic algorithms for selection of parameter configurations. IMD 14 delivers neurostimulation therapy to patient 12 via leads 16A and 16B (collectively “leads 16”). Leads 16 may, as shown in FIG. 1, be implanted proximate to the spinal cord 18 of patient 12, and IMD 14 may deliver spinal cord stimulation (SCS) therapy to patient 12 in order to, for example, reduce pain experienced by patient 12. However, the invention is not limited to the configuration of leads 16 shown in FIG. 1 or the delivery of SCS therapy. For example, one or more leads 16 may extend from IMD 14 to the brain (not shown) of patient 12, and IMD 14 may deliver deep brain stimulation (DBS) therapy to patient 12 to, for example, treat tremor or epilepsy. As further examples, one or more leads 16 may be implanted proximate to the pelvic nerves (not shown), sacrum (not shown) or stomach (not shown), and IMD 14 may deliver neurostimulation therapy to treat incontinence, sexual dysfunction, or gastroparesis. IMD 14 delivers neurostimulation therapy to patient 12 according to one or more neurostimulation therapy programs. A neurostimulation therapy program may include values for a number of parameters, and the parameter values define a parameter configuration for delivery of the neurostimulation therapy delivered according to that program. In embodiments where IMD 14 delivers neurostimulation therapy in the form of electrical pulses, the parameters may include pulse voltage or current amplitudes, pulse widths, pulse rates, durations and the like. Further, each of leads 16 includes electrodes (not shown in FIG. 1), and the parameters for a program may include information identifying which electrodes have been selected for delivery of pulses according to the program, and the polarities of the selected electrodes. Hence, a parameter configuration may involve one or more of a variety of parameters including electrode configuration, amplitude, pulse width, pulse rate, and duration. Although the invention may be applicable to neurostimulation parameter configuration in general, including configuration of parameters such as amplitude, pulse width, pulse rate, duration and electrode configuration, the invention generally will be described for purposes of illustration in the context of determining an electrode configuration. A selected subset of the electrodes located on leads 16 and the polarities of the electrodes of the subset collectively define an “electrode configuration.” The electrodes may be arranged in a standard inline lead configuration, or as a surgical paddle lead, grid or other format. The electrodes may be associated with different target regions within a body of a patient. Electrode configurations refer to combinations of single or multiple cathode electrodes and single or multiple anode electrodes. Stimulation current flows between the cathodes and anodes for delivery of neurostimulation therapy. Hence, the polarities of the individual electrodes are another feature of the electrode configuration. Electrodes forming part of an electrode configuration may reside together on a single lead or on different leads System 10 also includes a programmer 20. Programmer 20 may, as shown in FIG. 1, be a handheld computing device. Programmer 20 includes a display 22, such as a LCD or LED display, to display information to a user. Programmer 20 may also include a keypad 24, which may be used by a user to interact with programmer 20. In some embodiments, display 22 may be a touch screen display, and a user may interact with programmer 20 via display 22. A user may also interact with programmer 20 using peripheral pointing devices, such as a stylus or mouse. Keypad 24 may take the form of an alphanumeric keypad or a reduced set of keys associated with particular functions. A clinician (not shown) may use programmer 20 to program neurostimulation therapy for patient 12. In particular, the clinician may use programmer 20 to create neurostimulation therapy programs. As part of the program creation process, programmer 20 allows the clinician to identify parameter configurations that enable IMD 14 to deliver neurostimulation therapy that is desirable in terms of, for example, symptom relief, coverage area relative to symptom area, and side effects. Programmer 20 may also allow the clinician to identify parameter configurations that enable IMD 14 to deliver effective neurostimulation therapy with desirable device performance characteristics, e.g., low battery consumption. In addition, techniques as described herein may used to optimize therapy over the course of use of a chronically implanted IMD, e.g., by interaction between patient 12 and a patient programmer to record efficacy observations over time. In this case, a programmer carried by the patient may incorporate some or all of the functionality attributed to programmer 20 as described herein, including functionality designed to assist in identification of parameter configurations using genetic algorithms. Programmer 20 controls IMD 14 to test parameter configurations in order to allow a clinician to identify desirable parameter configurations in an efficient manner. As will be described in greater detail below, in some embodiments, programmer 20 selects parameter configurations to test based on an electrode configuration search algorithm, as described herein. In particular, according to such an algorithm, programmer 20 may first control IMD 14 to test one or more electrodes to identify a first electrode configuration, and then test other electrode configurations based on guidance built into the search algorithm. Other neurostimulation parameters such as amplitude, pulse width, pulse rate, and duration also may be evaluated with the electrode configuration. For example, various parameters may be observed simultaneously with observation of each electrode configuration. Alternatively, once a smaller set of electrode configurations has been identified as providing efficacy for a given baseline set of amplitude, pulse width and pulse rate, then different amplitude, pulse width and pulse rate parameters may be iteratively observed for that smaller set of electrode configurations. By controlling IMD 14 to test electrode configurations in an intelligent manner, programmer 20 allows the clinician to more quickly identify desirable electrode configurations. Duration of the delivery of neurostimulation energy also may be observed. In this manner, amplitude, pulse width, and pulse rate parameters need not be evaluated for every electrode configuration, and especially those electrode configurations that do not present a high probability of efficacy as inferred from the genetic algorithm solutions. By controlling IMD 14 to test parameter configurations in an intelligent manner, programmer 20 allows the clinician to more quickly identify desirable parameter configurations, reducing the overall amount of time the clinician spends programming neurostimulation therapy for patient 12. For example, in contrast to existing neurostimulation programming systems that present electrode configurations in a random order or idiosyncratic search methodologies employed by clinicians, programmer 20 may select electrode configurations to test in a way that is more likely to enable desirable configurations to be selected earlier in the search. Consequently, the clinician may be able to end the search before all potential electrode combinations have been tested if one or more desirable configurations have already been identified, saving the amount clinician and patient time required to achieve an efficacious electrode configuration. In addition, with the invention, it may be possible to identify optimal or near optimal parameter configurations that otherwise might not be identified by the clinician. Even if the clinician elects to test all potential electrode combinations, e.g., if the electrode set is small enough to make testing all electrode configurations practical, programmer 20 may reduce the time required to identify desirable electrode configurations by automating selection of each new configuration to test. Additionally, programmer 20 may improve the search process by collecting efficacy information for each combination tested. As will be described in greater detail below, programmer 20 may present a list of electrode configurations to the clinician, ordered according to the efficacy information, allowing the clinician to more easily identify and select desirable configurations. This list of electrode configurations may be ordered and updated according to newly observed efficacy information as additional electrode configurations are evaluated. Similar techniques may be applied for other neurostimulation parameters forming part of a parameter configuration, such as amplitude, pulse width, pulse rate, and duration. In order to control IMD 14 to test electrode combinations, programmer 20 may communicate with IMD 14 via telemetry techniques known in the art. For example, programmer 20 may communicate with IMD 14 via an RF telemetry head (not shown). Information identifying desirable combinations of electrodes identified by the clinician may be stored as part of parameter configurations associated with neurostimulation therapy programs. Neurostimulation therapy programs created by the clinician using programmer 20 may be transmitted to IMD 14 via telemetry, and/or may be transmitted to another programmer (not shown), e.g., a patient programmer, that is used by patient 12 to control the delivery of neurostimulation therapy by IMD 14. FIG. 2 is a block diagram illustrating an example configuration of leads 16. In the example configuration, lead 16A includes electrodes 26A-26H, and lead 16B includes electrodes 26I-26P. Hence, each lead 16 includes eight electrodes, although a lesser or greater number of electrodes are possible. Electrodes 26A-P (collectively “electrodes 26”) may be ring electrodes. Electrodes 26 collectively form an electrode set 28 implanted within patient 12. As shown in FIG. 2, electrode set 28 includes eight electrodes on each of the two leads 16, which, as shown in FIG. 1, are implanted such that they are substantially parallel to each other and spinal cord 18 (FIG. 1), on substantially opposite sides of spinal cord 18, at approximately the same height relative to spinal cord 18, and oriented such that the distal ends of leads 16 are higher relative to the spinal cord than the proximal ends of leads 16. Therefore, the illustrated configuration of electrode set 28 may be described as a two-by-eight, side-by-side, upwardly oriented configuration. Of course, electrode set 28 is provided for purposes of example, and the invention may be applicable to other types of leads and electrode sets, including single lead electrode sets, flat paddle leads, grid arrays, and the like. Such an electrode set is commonly used to provide SCS therapy. However, programmer 20 may be used to identify desirable combinations of electrodes within electrode sets that are configured in any way, and used to provide any type neurostimulation therapy. For example, a single lead including four or eight electrodes, two leads including four electrodes per lead, in-line leads, and offset leads, all of which may be oriented in any manner relative to patient 12, provide electrode set configurations that may be searched by programmer 20. In the example of FIG. 2, electrodes 26 are placed on opposite sides of the T7 vertebra 23, T8 vertebra 25 and T9 vertebra 27 of a human spine. IMD 14 (FIG. 1) may deliver neurostimulation via any combination of electrodes 26. IMD 14 may independently activate each electrode 26 of set 28 to act as a cathode or anode for a configuration, and .each configuration will include at least one cathode and at least one anode. In some embodiments, it is possible that an electrode configuration may include a single electrode 26 acting as the cathode, with a can of IMD 14, i.e., the IMD housing, acting as the anode for the configuration. In an electrode configuration, electrons flow from one or more electrodes acting as anodes for the configuration to one or more electrodes acting as cathodes for the configuration. The current between anodes and cathodes stimulates neurons between and proximate to the anodes and cathodes. Generally speaking, an electrode configuration enables desirable neurostimulation therapy when current is delivered in a direction and with an intensity sufficient to stimulate specific neurons or a sufficient number of specific neurons to alleviate a symptom without causing unacceptable side effects. Further, an electrode configuration enables desirable neurostimulation therapy when the symptom is alleviated without resorting to undesirably high pulse amplitudes. As mentioned above, programmer 20 selects individual electrodes 26 or electrode configuration to test to allow a clinician to identify desirable electrode configuration according to an electrode search algorithm. Programmer 20 may select an appropriate search algorithm based on the configuration of electrode set 28, and may select electrodes 26 or electrode configurations based on the selected search algorithm. Programmer 20 controls IMD 14 to test a selected electrode 26 or electrode combination by controlling IMD 14 to deliver neurostimulation via the selected electrode 26 or combination. In some embodiments, programmer 20 may first control IMD 14 to test one or more of electrodes 26 individually to identify the individual electrode or electrodes 26 which will act as a first cathode. In other embodiments, programmer 20 starts with a combination of selected electrodes 26. Generally, a clinician implants leads 16 in a location such that the center of electrode set 28 is proximate to an area that the clinician believes should be stimulated in order to alleviate symptoms. Therefore, programmer 20 may test electrodes 26 as the first cathode in an order such that electrodes 26 located centrally within electrode set 28, e.g., electrodes 26D-E and 26L-M illustrated in FIG. 2, are tested before peripherally located electrodes. If the clinician's estimation of the target region is inaccurate, programmer 20 will continue to test individual electrodes 26 in such an order until one of the electrodes 26 that enables desirable neurostimulation therapy when activated as the first cathode is identified. Initially locating a first cathode provides a “coarse” optimization of electrode combinations, allowing programmer 20 and the clinician to quickly identify the general area to which neurostimulation therapy should be delivered. Programmer 20 may then control IMD 14 to test electrode configurations that include the first cathode. The various electrode configurations may be tested with a common set of stimulation parameters, such as a common voltage or current amplitude, frequency, and pulse width. In some embodiments, a series of different stimulation parameters may be applied for each combination of electrodes to test not only the efficacy of electrode combinations, but also electrode combinations with particular stimulation parameters such as amplitude, frequency and pulse width. Hence, an electrode configuration may apply to the combination of electrodes forming part of the neurostimulation parameter configuration, and the parameters associated with delivery of neurostimulation energy via the electrodes, such as amplitude, pulse width and pulse rate, may form another part of the parameter configuration. Programmer 20 may control IMD 14 to try different ones of electrodes 26 as the first anode in a pair with the first cathode, and may add additional anodes and/or cathodes. In accordance with an embodiment of the invention, programmer 20 controls IMD 14 to test remaining electrodes 26 as first anodes, and additional anodes or cathodes, based on electrode configurations identified by genetic algorithms. The genetic algorithms may be employed by programmer 20 to allow a clinician to select electrode configurations, and then program IMD 14 to lead to optimum electrode configurations. The search algorithm uses the genetic algorithms to select possible electrode configurations based on the efficacies of parameter configurations already observed in the course of evaluation. The previous observations are used to refine the algorithms. In particular, the observations are used to compare the genetic algorithms to an applicable fitness function, and then refine, or “evolve,” the structure of the algorithms to select optimum parameter configurations, such as electrode configurations. The first generation of the genetic algorithms may be established based on an existing set of data, or developed based on the input of a neurostimulation expert, and then updated to produce new algorithms based on efficacy information for newly considered parameter configurations. With the aid of genetic algorithms, a programmer 20 provides a clinician with suggestions of electrode configurations that are likely to be efficacious given observations already obtained during the selection process. In response, the clinician may select the suggested electrode configurations next. In some cases, the selection of electrode configurations, or other parameters, may be automated in response to suggestions generated using the genetic algorithms. In other cases, the selection of the parameter configurations may require human intervention from the clinician, but be aided by the suggestions. FIG. 3 is a block diagram illustrating an example configuration of programmer 20. A clinician or other user may interact with a processor 30 via a user interface 31 in order to identify and select electrode configurations as described herein. User interface 31 may include display 22 and keypad 24 (FIG. 1), and may also include a touch screen or peripheral pointing devices as described above. Processor 30 may also provide a graphical user interface (GUI) via user interface 31 to facilitate interaction with a clinician, technician, or other medical personnel. Processor 30 may include a microprocessor, a controller, a DSP, an ASIC, an FPGA, discrete logic circuitry, or the like. Clinician programmer 20 also includes a memory 32. Memory 32 may include program instructions that, when executed by processor 30, cause clinician programmer 20 to perform the functions ascribed to clinician programmer 20 herein. For example, processor may execute one or more parameter configuration search algorithms 34 stored within memory 32. In particular, processor 30 may execute an electrode configuration search algorithm to select individual electrodes 26 or electrode combinations to test to allow the clinician to identify desirable electrode combinations. Search algorithm 34 executes based on the genetic algorithm, which yields electrode configurations within electrode set 28 with increased efficacy. In particular, search algorithm 34 is evaluated according to one or more fitness functions 36 stored within memory 32 to generate new algorithms designed to lead to better parameter configurations. Hence, programmer 20 provides interactive guidance to a clinician during the process of optimizing implantable device parameters. In particular, programmer 20 guides the clinician by suggesting the electrode configurations that are most likely to be efficacious given the results of tests already performed during the source of an evaluation session. This is accomplished by building the genetic algorithm based on previous results. Search algorithm 34, in the form of genetic algorithms that evolve according to search results, encode potential solutions to a problem as members of a population of solutions. This population is then judged based on fitness function 36. The best performers, i.e., the most fit solutions, are then retained and a new generation is created based upon their characteristics. The new generation comprises solutions similar in nature to the best performers of the previous generation. This process of creation can use one or more techniques for generating new solutions. These techniques include cross-over, i.e., sharing of parts of a solution from one member to another, and mutation, i.e., random changes within a solution from one generation to the next. Each potential solution (parameter configuration) can be encoded as one member of the population. As an example, one solution might encode values for amplitude, rate, pulse width, and electrode combination of a stimulation device therapy. The fitness function used for selection then becomes the efficacy rating assigned by the patient when the clinician tries the parameter configuration corresponding to the solution during a session. In general, efficacy refers to the balance between therapeutic benefit and undesirable side effects. As examples, efficacy can be observed by verbal feedback from the patient concerning therapeutic benefit and side effects, marking of a pain/parasthesia map, objective measurement using pain rating scales, quantification of side effects, a combination of the forgoing, or other observation techniques. After some number of ratings are collected, the system ‘kills’ off the least fit solution, generates a new population based upon the more fit, and continues the cycle. This repeats until a satisfactory solution is discovered, or “evolved.” As an illustration, genetic algorithms can be applied to the problem of determining the best electrode configuration for a specific individual. The solutions to this problem are possible configurations of the electrodes on the leads, such as the electrodes 26 depicted in FIG. 2. These solutions might be encoded by a series of characters—‘o’ representing off, ‘+’ representing the anode, and ‘−’ representing the cathode. A lead configuration for a 2×8 system as shown in FIG. 2 may then be encoded as follows. Lead 1 Lead 2 oooo+−oo oo−+oooo Hence, in the above example, a fifth electrode (+) in the first lead and a fourth electrode (+) in the second lead represent selection as anodes, whereas the sixth electrode (−) in the first lead and the third electrode (−) in the second lead represent selection as cathodes. A population of such solutions could then be generated at random to seed genetic search algorithm 34. Alternatively, the search algorithm 34 can be seeded with a population hand-picked by system designers as a good starting point. For this example, a population size of three will be chosen. In practice, this population size may be larger. The set of three genetic algorithm solutions may be represented as follows: Lead 1 Lead 2 Solution #1 oooo+−oo oo−+oooo Solution #2 +−oooooo oooooo+− Solution #3 ooo+−ooo oooo+−oo The above solutions can then each be trialed by the clinician and rated by the patient in terms of efficacy, which may reflect both positives such as therapeutic benefit and negatives such as side-effects. Assume, for the purposes of this example, that the first and last solutions (#1 and #3) were rated highly and the middle solution (#2) was rated poorly. Processor 30 in programmer 20 would then generate a new set of solutions using crossover and/or mutation. In this domain, examples of crossover may involve swapping selected single electrodes from one solution to another, swapping bipoles from one solution to another, and swapping ranges of electrodes, e.g., the bottom four, middle four, or top four electrode values with another solution. Examples of mutation may involve adding a single electrode at a random location (cathode or anode), adding a single electrode near exising electrodes (cathode or anode), adding a pair of electrodes, removing a single electrode, inveting polarities of pairs (cathode to anode, anode to cathode), inverting polarities of single electrodes, shifting all elctrodes up or down a lead, and randomly turning two adjacent off-electrodes into a bipole pair. Other variations on crossover or mutation may be viable. All of these crossover and mutation techniques need not be used at one. In general, one may try to balance speed of convergence with optimality of the end result. For instance, since is is known that the problem is relatively dependent on the locations of the electrodes, experimenting “near” a known good electrode combination will cause solutions to converge more quickly. For example, mutation may be conducted only near existing electrodes. However, this approach may cause the algorithm to exclude more radical solutions that may work better. In this case, mutation on a more random basis may be more desirable. The solution population for the next generation might look as follows: Lead 1 Lead 2 Solution #4 ooo+−ooo oo−++−oo //new solution formed by crossing over first 4 electrodes of second lead of old solution #1 to old solution #3 Solution #5 o+−o+−oo oo−+oooo //new solution formed by mutating 2nd and 3rd electrodes of old solution #1 Solution #6 ooo+−ooo oooo+−oo //new solution formed by bringing forward old solution #3 unchanged. This process of creating new generations of solutions, e.g., by cross-over, mutation, or a combination of both, then repeats until a satisfactory solution is reached. For example, the process may repeat until one of the solutions satisfies an efficacy threshold. This process may be implemented, as described herein, as a feature of clinician programmer 20, with the evolution of solutions occurring within a clinical visit. As an alternative, or in addition, this process may also be implemented within a patient programmer. In this configuration, the patient would initiate a new cycle when he or she was dissatisfied with the current therapy. The patient device would then present the new population and capture the patient's efficacy ratings. The patient could then repeat this process at his or her leisure until an optimal solution was achieved. Processor 30 collects information relating to the parameter configurations identified by the genetic algorithm process, and stores the information in memory 32 for later retrieval and review by the clinician to facilitate identification of desirable parameter configurations. Neurostimulation therapy programs 38 created by the clinician may be stored in memory 32, and information identifying electrode configurations selected by the clinician to be utilized for one or more of programs 38 with the aid of the genetic algorithms may be stored as part of the programs 38 within memory 32. Memory 32 may include any volatile, non-volatile, fixed, removable, magnetic, optical, or electrical media, such as a RAM, ROM, CD-ROM, hard disk, removable magnetic disk, memory cards or sticks, NVRAM, EEPROM, flash memory, and the like. Processor 30 controls IMD 14 to test selected individual electrodes 26 or electrode combinations, by controlling IMD 14 to deliver neurostimulation therapy to patient 12 via the selected individual electrodes 26 or electrode combinations via a telemetry circuit 40. Processor 30 may transmit programs 38 created by the clinician to IMD 14 via telemetry circuit 40, or to another programmer used by the patient to control delivery of neurostimulation therapy via input/output circuitry 42. I/O circuitry 42 may include transceivers for wireless communication, appropriate ports for wired communication or communication via removable electrical media, or appropriate drives for communication via removable magnetic or optical media. Using the genetic algorithm process, programmer 20 provides suggestions on which electrode configurations are most likely to be efficacious. In this manner, the genetic algorithms can be used to guide the clinician to a set of optimum parameter configurations, such as electrode configurations, for evaluation, reducing the number of observations that need be made to ensure a good outcome. In other words, the genetic algorithms may permit the clinician to avoid a number of parameter configurations that, based on previous experience, are unlikely to yield efficacious results. Rather, the genetic algorithms lead to solutions that provide optimum electrode configurations. The genetic technique benefits from past observations, and is more likely to produce optimum efficacy results. FIG. 4 is a flow diagram illustrating a process that is executable by a programmer to select parameter configurations using genetic algorithms as described herein. The example of FIG. 4 is directed to electrode configurations for purposes of illustration. As shown in FIG. 4, the process involves initiating a genetic search algorithm (44) to generate one or more electrode configuration solutions (46). The solutions are evaluated using a fitness function (48). The fitness function may be based on overall efficacy ratings provided by a patient. The efficacy rating can be solicited from the patient by the clinician, or entered directly by the patient. Again, efficacy refers to the balance between therapeutic benefit and undesirable side effects. As examples, efficacy ratings can be obtained by verbal feedback from the patient concerning therapeutic benefit and side effects, marking of a pain/parasthesia map, objective measurement using pain rating scales, quantification of side effects, a combination of the forgoing, or other observation techniques. Then, the process involves genetically refining the solutions based on fitness (50). For example, the solutions may be genetically refined using techniques such as cross-over, i.e., by sharing of parts of a solution from one member to another, and/or mutation, i.e., by incorporating random changes within a solution from one generation to the next, or combinations of both. Upon evaluating the solutions with the fitness function (51), the fitness level is compared to a fitness threshold (52). The fitness threshold may relate to a desired efficacy threshold. Again, the efficacy may be rated positively in terms of pain relief or other therapeutic benefit, and negatively in terms of side effects of the therapy. The search capability can be implemented as a feature in an implantable device programmer 20. When a fitness threshold is satisfied (52), the electrode configuration or configurations represented by the present solution or set of solutions are added to a neurostimulation program for selection by the clinician (56). If the fitness threshold is not satisfied (52), and an iteration limit has been exceeded (54), the algorithm terminates. In this case, the current electrode configuration may be selected and added to a neurostimulation program (56), or the clinician may be prompted to take other action. If the iteration limit is not exceeded (54), the genetic algorithm process continues iteratively (58) until the efficacy threshold is satisfied or the iteration limit is exceeded. The iteration limit may be established by the clinician. If the clinician stops the search before all possible combinations of electrodes 26 have been tested, programmer 20 may create a bracket of untested combinations that the clinician may elect to include in neurostimulation therapy programs. The bracket may consist of any number of electrode combinations, and may comprise the next n combinations that would have been tested according to the electrode combination search algorithm. By providing the clinician with a bracket, programmer 20 may allow clinician to spend less time searching for desirable electrode combinations in a subsequent programming session. Specifically, the programs created using the bracket combinations may enable desirable neurostimulation therapy similar to that provided in a program created with the most recently tested combination, and may be provided to patient 12 so that patient 12 can experiment with the bracket programs outside of the clinic. As described herein, programmer 20 controls IMD 14 to test electrode configurations by controlling IMD 14 to deliver neurostimulation therapy via combinations of electrodes. In addition, programmer 20 may be configured to facilitate a search for other optimum therapy parameters. For example, the clinician or programmer 20 may select desired starting points for pulse amplitude, rate and pulse width for each electrode configuration, and programmer 20 may ramp the amplitude from the starting point at a first rate of amplitude increase using similar techniques. Programmer 20 may increase the amplitude in, for example, a linear or step-wise fashion. In some embodiments, the clinician or patient 12 may control the rate of amplitude increase. The clinician or patient 12 stops the ramping of the amplitude when the stimulation causes discomfort, or other undesirable side effects. Programmer 20 may reduce the amplitude at the time the ramp is stopped by some amount, e.g., a percentage, and ramps the amplitude again in order to allow the clinician and/or patient 12 to identify the amplitude that provides the best neurostimulation therapy. This second time, programmer 20 may ramp the amplitude at a slower rate of amplitude increase in order to facilitate identification of the point where best neurostimulation is achieved. Again, in some embodiments, the clinician or patient 12 may control the amplitude. Programmer 20 stores the amplitude at the time when the best neurostimulation therapy is indicated by the clinician and/or patient 12, and rating information for the electrode combination. The clinician and/or patient 12 may provide efficacy rating information, e.g., a numerical value for one or more metrics for rating the combination, which relates to the efficacy enabled by the combination or the side effects resulting from use of the combination, or both. The clinician may use rating information and/or the amplitude values stored for each tested combination to identify desirable electrode configurations. The configurations and their associated information and values may be presented in a list that may be ordered according to the information, the values, or a combination of the two. The amplitude value may, for example, be used to distinguish between tested combinations with similar ratings based on the power that must be consumed in order for each combination to enable desirable neurostimulation therapy. Various embodiments of the invention have been described. However, one skilled in the art will appreciate that various additions and modifications can be made to these embodiments without departing from the scope of the invention. The invention may be generally applicable to any programming optimization problem in which the feedback from a configuration is available relatively quickly and within the context of the clinical programming environment. This includes the stimulation therapies for pain and movement disorders and may include other stimulation-based therapies as well. For example, although programmer 20 has been described herein as a hand-held computing device, programmer 20 may take the form of any type of computing device, such as a laptop or desktop computer, may access resources, such as memory 54, via a computer network, such as a LAN, WAN, or the World Wide Web. Further, programmer 20 may include a plurality of computing devices, which may communicate to provide the functionality ascribed to programmer 20 herein via a computer network. Although described herein as associated with and interacting with a clinician, i.e., a clinician programmer, programmer 20 may be associated with patient 12, i.e., a patient programmer. In some embodiments, patient 12 may simply interact with programmer 20 in place of the clinician for some or all of the electrode combination identification process. In other embodiments, patient 12 may perform parts of the configuration identification process without being supervised by the clinician, e.g., away from the clinic, using a patient programmer. These and other embodiments are within the scope of the following claims. | <SOH> BACKGROUND <EOH>Implantable medical devices are used to deliver neurostimulation therapy to patients to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson's disease, epilepsy, incontinence, sexual dysfunction, or gastroparesis. The implantable medical device delivers neurostimulation therapy via one or more leads that include electrodes located proximate to the spinal cord, pelvic nerves, sacrum, or stomach, or within the brain of a patient. In general, the implantable medical device delivers neurostimulation therapy in the form of electrical pulses. A clinician selects values for a number of programmable parameters in order to define a parameter configuration for the neurostimulation therapy to be delivered to a patient. For example, the clinician may select an amplitude, which may be a current or voltage amplitude, and pulse width for a stimulation waveform to be delivered to the patient, as well as a rate at which the pulses are to be delivered to the patient, and duration for which the stimulation energy is delivered. In addition, the clinician also selects particular electrodes within an electrode set to be used to deliver the pulses, and the polarities of the selected electrodes. The electrode combinations and polarities may be referred to as an electrode configuration. Hence, a parameter configuration may involve a variety of parameters including electrode configuration, amplitude, pulse width, pulse rate, and duration. The process of selecting parameter configurations can be time consuming, and may require a great deal of trial and error before an optimum electrode configuration is discovered. The optimum parameter configuration may be better than other configurations in balancing clinical results and side effects experienced by the patient. This balance represents overall efficacy of a parameter configuration. The process for selecting parameter configurations can be difficult due to the combinatorial possibilities of parameters, the complexity of the underlying biophysics, and subjective and possibly inconsistent feedback from the patient concerning observed efficacy for a given parameter configuration. | <SOH> SUMMARY <EOH>In general, the invention is directed to a technique for selection of parameter configurations for a neurostimulator using genetic algorithms. The technique may be employed by a programming device to allow a clinician to select parameter configurations, and then program an implantable neurostimulator to deliver therapy using the selected parameter configurations. A parameter configuration may define one or more parameters for delivery of neurostimulation, such as electrode configuration, amplitude, pulse width, pulse rate, or duration. For example, the parameter configurations may define electrode configurations that specify electrode combinations and polarities for an electrode set implanted in a patient. The electrode set may be carried by one or more implanted leads that are electrically coupled to the neurostimulator. In some embodiments, the parameter configurations may further define one or more parameters such as amplitudes, pulse widths, pulse rates, and durations of stimulation energy delivered by electrodes in the electrode configuration. In operation, the programming device executes a parameter configuration search algorithm to guide the clinician in the selection of parameter configurations. The search algorithm relies on genetic algorithms to identify potential optimum parameter configurations, such as electrode configurations within an electrode set. The genetic algorithms provide guidance in the electrode configuration selections process, interactively guiding the clinician by suggesting the configurations that are most likely to be efficacious given the results of tests already performed during an evaluation session. Genetic algorithms encode potential solutions to a problem as members of a population of solutions. This population is then judged based on a fitness function. The best performers, i.e., the most fit solutions, are then retained and a new generation is created based upon their characteristics. The new generation is composed of solutions similar in nature to the best performers of the previous generation. This process of creation can use one or more techniques for generating new solutions. These techniques include cross-over, i.e., sharing of parts of a solution from one member to another, and mutation, i.e., random changes within a solution from one generation to the next. Hence, the genetic algorithm identifies solutions associated with the different parameter configurations, and updates the genetic algorithm by generating one or more successive generations of the solutions, e.g., by cross-over or mutation. These techniques can be applied to the problem of parameter optimization, including selection of electrode configurations. Each potential solution, such as a parameter or electrode configuration, can be encoded as one member of the population. As an example, one solution might encode values for amplitude, rate, pulse width, and electrode combination of a stimulation device therapy. The fitness function used for selection then becomes the subjective efficacy rating assigned by the patient when the clinician tries the solution during a session. After some number of ratings are collected, the system ‘kills’ off the least fit, generates a new population based upon the more fit, and continues the cycle. This repeats until a satisfactory solution is discovered, or “evolved.” In one embodiment, the invention provides a method comprising selecting a first parameter configuration for a neurostimulator, receiving an indication of observed efficacy of the first parameter configuration, and selecting a second parameter configuration for the neurostimulator based on the indication of observed efficacy and a genetic algorithm. In another embodiment, the invention provides a computer-readable medium comprising instructions to cause a processor to select a first parameter configuration for a neurostimulator, receive an indication of observed efficacy of the first parameter configuration, and select a second parameter configuration for the neurostimulator based on the indication of observed efficacy and a genetic algorithm. In a further embodiment, the invention provides a device comprising a processor programmed to select a first parameter configuration for a neurostimulator, receive an indication of observed efficacy of the first parameter configuration, and select a second parameter configuration for the neurostimulator based on the indication of observed efficacy and a genetic algorithm. The invention may provide a number of advantages. For example, the invention may allow a clinician to more quickly identify desirable parameter configurations such as electrode combinations, reducing the overall amount of time the clinician spends programming neurostimulation therapy for a patient. In contrast to random or idiosyncratic search techniques, a technique based on genetic algorithms is capable of learning from the evaluation of earlier parameter configurations, and developing a series of algorithms that lead to an optimum configuration. In general, the invention can reduce the length of a programming session for the clinician and the patient, and support selection of optimum electrode configurations to achieve overall efficacy. In addition, with the invention, it may be possible to identify optimal or near optimal parameter configurations that otherwise might not be identified by the clinician. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. | 20040129 | 20070703 | 20050317 | 69711.0 | 0 | BOCKELMAN, MARK | SELECTION OF NEUROSTIMULATOR PARAMETER CONFIGURATIONS USING GENETIC ALGORITHMS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,767,779 | ACCEPTED | Methods of amplifying and sequencing nucleic acids | An apparatus and method for performing rapid DNA sequencing, such as genomic sequencing, is provided herein. The method includes the steps of preparing a sample DNA for genomic sequencing, amplifying the prepared DNA in a representative manner, and performing multiple sequencing reaction on the amplified DNA with only one primer hybridization step. | 1. A method for sequencing nucleic acids comprising: (a) fragmenting large template nucleic acid molecules to generate a plurality of fragmented nucleic acids; (b) delivering the fragmented nucleic acids into aqueous microreactors in a water-in-oil emulsion such that a plurality of aqueous microreactors comprise a single copy of a fragmented nucleic acid, a single bead capable of binding to the fragmented nucleic acid, and amplification reaction solution containing reagents necessary to perform nucleic acid amplification; (c) amplifying the fragmented nucleic acids in the microreactors to form amplified copies of said nucleic acids and binding the amplified copies to beads in the microreactors; (d) delivering the beads to an array of at least 10,000 reaction chambers on a planar surface, wherein a plurality of the reaction chambers comprise no more than a single bead; and (e) performing a sequencing reaction simultaneously on a plurality of the reaction chambers. 2. The method of claim 1 wherein the reaction chambers have a center to center spacing of 20 to 100 μm. 3. The method of claim 1 wherein the fragmented nucleic acids are 30-500 bases. 4. The method of claim 1 wherein a plurality of the beads bind at least 10,000 amplified copies. 5. The method of claim 1 wherein step (c) is accomplished using polymerase chain reaction. 6. The method of claim 1 wherein the sequencing reaction is a pyrophosphate-based sequencing reaction. 7. The method of claim 1 wherein the sequencing reaction comprises the steps of: (a) annealing an effective amount of a sequencing primer to the amplified copies of the nucleic acid and extending the sequencing primer with a polymerase and a predetermined nucleotide triphosphate to yield a sequencing product and, if the predetermined nucleotide triphosphate is incorporated onto a 3′ end of said sequencing primer, a sequencing reaction byproduct; and (b) identifying the sequencing reaction byproduct, thereby determining the sequence of the nucleic acid in a plurality of the reaction chambers. 8. The method of claim 1 wherein the sequencing reaction comprises the steps of: (a) hybridizing two or more sequencing primers to one or a plurality of single strands of the nucleic acid molecule wherein all the primers except for one are reversibly blocked primers; (b) incorporating at least one base onto the nucleic acid molecule by polymerase elongation from an unblocked primer; (c) preventing further elongation of said unblocked primer; (d) deblocking one of the reversibly blocked primers into an unblocked primer; and (e) repeating steps (b) to (d) until at least one of the reversibly blocked primers are deblocked and used for determining a sequence. 9. The method of claim 1 wherein the reaction chambers are cavities formed by etching one end of a fiber optic bundle. 10. An array comprising a planar surface with a plurality of cavities thereon, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and each cavity has a width in at least one dimension of between 20 μm and 70 μm, and wherein there are at least 10,000 reaction chambers. 11. The array of claim 10 wherein a plurality of reaction chambers contains at least 100,000 copies of a single species of single stranded nucleic acid template. 12. The array of claim 11 wherein the single stranded nucleic acid templates are immobilized on mobile solid supports disposed in the reaction chambers. 13. The array of claim 10 wherein the center to center spacing is between 40 to 60 μm. 14. The array of claim 10 wherein each cavity has a depth of between 20 μm and 60 μm. 15. An array comprising a planar top surface and a planar bottom surface wherein the planar top surface has at least 10,000 cavities thereon, each cavity forming an analyte reaction chamber, the planar bottom surface is optically conductive such that optical signals from the reaction chambers can be detected through the bottom planar surface, wherein the distance between the top surface and the bottom surface is no greater than 5 mm, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and each chamber having a width in at least one dimension of between 20 μm and 70 μm. 16. The array of claim 15 wherein the distance between the top surface and the bottom surface is no greater than 2 mm. 17. The array of claim 10 or 15 wherein the number of cavities is greater than 50,000. 18. The array of claim 10 or 15 wherein the number of cavities is greater than 100,000. 19. The array of claim 10 or 15 wherein the shape of each reaction chamber is substantially hexagonal. 20. The array of claim 10 or 15 wherein each cavity has at least one irregular wall surface. 21. The array of claim 10 or 15 wherein the array is formed in a fused fiber optic bundle. 22. The array of claim 10 or 15 wherein each cavity has a smooth wall surface. 23. The array of claim 10 or 15 wherein the cavities are formed by etching one end of the fiber optic bundle. 24. The array of claim 10 or 15 wherein each cavity contains reagents for analyzing a nucleic acid or protein. 25. The array of claim 10 or 15 further comprising a second surface spaced apart from the planar array and in opposing contact therewith such that a flow chamber is formed over the array. 26. An array means for carrying out separate parallel common reactions in an aqueous environment, wherein the array means comprises a substrate comprising at least 10,000 discrete reaction chambers containing a starting material that is capable of reacting with a reagent, each of the reaction chambers being dimensioned such that when one or more fluids containing at least one reagent is delivered into each reaction chamber, the diffusion time for the reagent to diffuse out of the well exceeds the time required for the starting material to react with the reagent to form a product. 27. The array of claim 26 wherein each cavity contains reagents for analyzing a nucleic acid or protein. 28. The array of claim 26 further comprising a population of mobile solid supports disposed in the reaction chambers, each mobile solid support having one or more bioactive agents attached thereto. 29. The array of claim 26 wherein the cavities are formed in the substrate via etching, molding or micromaching. 30. The array of claim 17 wherein the substrate is a fiber optic bundle. 31. The array of claims 10, 15 or 26 wherein at least 5% to 20% of the reaction chambers contain at least one mobile solid support having at least one reagent immobilized thereon. 32. The array of claims 10, 15 or 26 wherein at least 20% to 60% of the reaction chambers have at least one mobile solid support having at least one reagent immobilized thereon. 33. The array of claims 10, 15 or 26 wherein at least 50% to 100% of the reaction chambers have at least one mobile solid support having at least one reagent immobilized thereon. 34. The array of claim 31 wherein the reagent immobilized on the mobile solid support is a polypeptide with sulfurylase activity. 35. The array of claims 31 wherein the reagent immobilized on the mobile solid support is a polypeptide with luciferase activity. 36. The array of claims 31 wherein the mobile solid support has both sulfurylase and luciferase immobilized. 37. The array of claim 31 wherein a plurality of reaction chambers contains at least 100,000 copies of a single species of single stranded nucleic acid template. 38. The array of claim 31 wherein the single stranded nucleic acid templates are immobilized on mobile solid supports disposed in the reaction chambers. 39. The array of claim 10, 15 or 26 wherein the nucleic acid is suitable for use in a pyrosequencing reaction. 40. A method for delivering a bioactive agent to an array, comprising dispersing over the array a plurality of mobile solid supports, each mobile solid support having at least one reagent immobilized thereon, wherein the reagent is suitable for use in a nucleic acid sequencing reaction, where the array comprises a planar surface with a plurality of reaction chambers disposed thereon, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and each reaction chamber has a width in at least one dimension of between 20 μm and 70 μm. 41. An apparatus for simultaneously monitoring an array of reaction chambers for light indicating that a reaction is taking place at a particular site, the apparatus comprising: (a) an array of reaction chambers formed from a planar substrate comprising a plurality of cavitated surfaces, each cavitated surface forming a reaction chamber adapted to contain analytes, and wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, each reaction chamber having a volume of between 10 to 150 pL, the array comprising more than 10,000 discrete reaction chambers; (b) an optically sensitive device arranged so that in use the light from a particular reaction chamber will impinge upon a particular predetermined region of said optically sensitive device; (c) means for determining the light level impinging upon each of said predetermined regions and (d) means to record the variation of said light level with time for each of said reaction chamber. 42. An analytic sensor, comprising: (a) an array formed from a first bundle of optical fibers with a plurality of cavitated surfaces at one end thereof, each cavitated surface forming a reaction chamber adapted to contain analytes, and wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, a width of 20 to 70 μm, the array comprising more than 10,000 discrete reaction chambers; (b) an enzymatic or fluorescent means for generating light in the reaction chambers; (c) light detection means comprising a light capture means and a second fiber optic bundle for transmitting light to the light detecting means, the second fiber optic bundle being in optical contact with the array, such that light generated in an individual reaction chamber is captured by a separate fiber or groups of separate fibers of the second fiber optic bundle for transmission to the light capture means. 43. The sensor of claim 42 wherein said sensor is suitable for use in a biochemical assay. 44. The sensor of claim 42 wherein said sensor is suitable for use in a cell-based assay. 45. The sensor of claim 42 wherein the light capture means is a CCD camera. 46. The sensor of claim 42 wherein the reaction chambers contain one or more mobile solid supports with a bioactive agent immobilized thereon. 47. A method for carrying out separate parallel common reactions in an aqueous environment, comprising: (a) delivering a fluid containing at least one reagent to an array, wherein the array comprises a substrate comprising at least 10,000 discrete reaction chambers, each reaction chamber adapted to contain analytes, and wherein the reaction chambers have a volume of between 10 to 150 pL and containing a starting material that is capable of reacting with the reagent, each of the reaction chambers being dimensioned such that when the fluid is delivered into each reaction chamber, the diffusion time for the reagent to diffuse out of the well exceeds the time required for the starting material to react with the reagent to form a product; and (b) washing the fluid from the array in the time period (i) after the starting material has reacted with the reagent to form a product in each reaction chamber but (ii) before the reagent delivered to any one reaction chamber has diffused out of that reaction chamber into any other reaction chamber. 48. The method of claim 47 wherein the product formed in any one reaction chamber is independent of the product formed in any other reaction chamber, but is generated using one or more common reagents 49. The method of claim 47 wherein the starting material is a nucleic acid sequence and at least one reagent in the fluid is a nucleotide or nucleotide analog 50. The method of claim 47 wherein the fluid additionally comprises a polymerase capable of reacting the nucleic acid sequence and the nucleotide or nucleotide analog 51. The method of claim 47 additionally comprising repeating steps (a) and (b) sequentially. 52. A method for delivering nucleic acid sequencing enzymes to an array, said array having a planar surface with a plurality of cavities thereon, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm; the method comprising dispersing over the array a plurality of mobile solid supports having one or more nucleic acid sequencing enzymes immobilized thereon, such that a plurality of the reaction chambers contain at least one mobile solid support. 53. The method of claim 52 wherein one of the nucleic acid sequencing enzymes is a polypeptide having sulfurylase activity, luciferase activity or both. 54. A method for delivering a plurality of nucleic acid templates to an array, said array having a planar surface with a plurality of cavities thereon, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and the array having at least 10,000 reaction chambers; the method comprising dispersing over the array a plurality of mobile solid supports, each mobile solid support having no more than a single species of nucleic acid template immobilized thereon, the dispersion causing no more than one mobile solid support to be disposed within any one reaction chamber. 55. The method of claim 54 wherein the nucleic acid sequence is a single stranded nucleic acid. 56. The method of claim 54 wherein at least 100,000 copies of a single species of nucleic acid template are immobilized on a plurality of the mobile solid supports. 57. The method of claim 54 wherein each single species of nucleic acid template is amplified on a picotiter plate to produce at least 2,000,000 copies per well of said nucleic acid template after being disposed in the reaction chamber. 58. The method of claim 57 wherein the nucleic acid sequence is amplified using an amplification technology selected from the group consisting of polymerase chain reaction, ligase chain reaction and isothermal DNA amplification. 59. A method for sequencing a nucleic acid, the method comprising: (a) providing a plurality of single-stranded nucleic acid templates disposed within a plurality of cavities on a planar surface, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and the planar surface has at least 10,000 reaction chambers; (b) performing a pyrophosphate based sequencing reaction simultaneously on all reaction chambers by annealing an effective amount of a sequencing primer to the nucleic acid templates and extending the sequencing primer with a polymerase and a predetermined nucleotide triphosphate to yield a sequencing product and, if the predetermined nucleotide triphosphate is incorporated onto the 3′ end of said sequencing primer, a sequencing reaction byproduct; and (c) identifying the sequencing reaction byproduct, thereby determining the sequence of the nucleic acid in each reaction chamber. 60. The method of claim 59, wherein the sequencing reaction byproduct is PPi and a coupled sulfurylase/luciferase reaction is used to generate light for detection. 61. The method of claim 60, wherein either or both of the sulfurylase and luciferase are immobilized on one or more mobile solid supports disposed at each reaction site. 62. A method of determining the base sequence of a plurality of nucleotides on an array, the method comprising: (a) providing at least 10,000 DNA templates, each separately disposed within a plurality of cavities on a planar surface, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, and a volume of between 10 to 150 pL; wherein (b) adding an activated nucleotide 5′-triphosphate precursor of one known nitrogenous base to a reaction mixture in each reaction chamber, each reaction mixture comprising a template-directed nucleotide polymerase and a single-stranded polynucleotide template hybridized to a complementary oligonucleotide primer strand at least one nucleotide residue shorter than the templates to form at least one unpaired nucleotide residue in each template at the 3′-end of the primer strand, under reaction conditions which allow incorporation of the activated nucleoside 5′-triphosphate precursor onto the 3′-end of the primer strands, provided the nitrogenous base of the activated nucleoside 5′-triphosphate precursor is complementary to the nitrogenous base of the unpaired nucleotide residue of the templates; (c) detecting whether or not the nucleoside 5′-triphosphate precursor was incorporated into the primer strands in which incorporation of the nucleoside 5′-triphosphate precursor indicates that the unpaired nucleotide residue of the template has a nitrogenous base composition that is complementary to that of the incorporated nucleoside 5′-triphosphate precursor; and (d) sequentially repeating steps (b) and (c), wherein each sequential repetition adds and, detects the incorporation of one type of activated nucleoside 5′-triphosphate precursor of known nitrogenous base composition; and (e) determining the base sequence of the unpaired nucleotide residues of the template in each reaction chamber from the sequence of incorporation of said nucleoside precursors. 63. A method of identifying the base in a target position in a DNA sequence of template DNA, wherein: (a) at least 10,000 separate DNA templates are separately disposed within a plurality of cavities on a planar surface, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, said DNA being rendered single stranded either before or after being disposed in the reaction chambers, (b) an extension primer is provided which hybridizes to said immobilized single-stranded DNA at a position immediately adjacent to said target position; (c) said immobilized single-stranded DNA is subjected to a polymerase reaction in the presence of a predetermined deoxynucleotide or dideoxynucleotide, wherein if the predetermined deoxynucleotide or dideoxynucleotide is incorporated onto the 3′ end of said sequencing primer then a sequencing reaction byproduct is formed; and (d) identifying the sequencing reaction byproduct, thereby determining the nucleotide complementary to the base at said target position in each of the 10,000 DNA templates. 64. The method of claim 63 wherein in place of deoxy- or dideoxy adenosine triphosphate (ATP) a dATP or ddATP analogue is used which is capable of acting as a substrate for a polymerase but incapable of acting as a substrate for said PPi-detection enzyme. 65. An apparatus for analyzing a nucleic acid sequence, the apparatus comprising: (a) a reagent delivery cuvette, wherein the cuvette includes an array comprising a planar surface with a plurality of cavities thereon, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, and there are in excess of 10,000 reaction chambers, and wherein the reagent delivery cuvette contains reagents for use in a sequencing reaction; (b) a reagent delivery means in communication with the reagent delivery cuvette; (c) an imaging system in communication with the reagent delivery chamber; and (d) a data collection system in communication with the imaging system. 66. An apparatus for determining the base sequence of a plurality of nucleotides on an array, the apparatus comprising: (a) a reagent cuvette containing a plurality of cavities on a planar surface, each cavity forming an analyte reaction chamber, wherein there are in excess of 10,000 reaction chambers, each having a center to center spacing of between 20 to 100 μm and a volume of between 10 to 150 pL; (b) reagent delivery means for simultaneously adding to each reaction chamber an activated nucleotide 5′-triphosphate precursor of one known nitrogenous base to a reaction mixture in each reaction chamber, each reaction mixture comprising a template-directed nucleotide polymerase and a single-stranded polynucleotide template hybridized to a complementary oligonucleotide primer strand at least one nucleotide residue shorter than the templates to form at least one unpaired nucleotide residue in each template at the 3′-end of the primer strand, under reaction conditions which allow incorporation of the activated nucleoside 5′-triphosphate precursor onto the 3′-end of the primer strands, provided the nitrogenous base of the activated nucleoside 5′-triphosphate precursor is complementary to the nitrogenous base of the unpaired nucleotide residue of the templates; (c) detection means for detecting in each reaction chamber whether or not the nucleoside 5′-triphosphate precursor was incorporated into the primer strands in which incorporation of the nucleoside 5′-triphosphate precursor indicates that the unpaired nucleotide residue of the template has a nitrogenous base composition that is complementary to that of the incorporated nucleoside 5′-triphosphate precursor; and (d) means for sequentially repeating steps (b) and (c), wherein each sequential repetition adds and, detects the incorporation of one type of activated nucleoside 5′-triphosphate precursor of known nitrogenous base composition; and (e) data processing means for determining the base sequence of the unpaired nucleotide residues of the template simultaneously in each reaction chamber from the sequence of incorporation of said nucleoside precursors. 67. An apparatus for processing a plurality of analytes, the apparatus comprising: (a) a flow chamber having disposed therein a substrate comprising at least 50,000 cavitated surfaces on a fiber optic bundle, each cavitated surface forming a reaction chamber adapted to contain analytes, and wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and a diameter of 20 to 70 μm; (b) fluid means for delivering processing reagents from one or more reservoirs to the flow chamber so that the analytes disposed in the reaction chambers are exposed to the reagents; and (c) detection means for simultaneously detecting a sequence of optical signals from each of the reaction chambers, each optical signal of the sequence being indicative of an interaction between a processing reagent and the analyte disposed in the reaction chamber, wherein the detection means is in communication with the cavitated surfaces. 68. The apparatus of claim 67 wherein the detection means is a CCD camera. 69. The apparatus of claim 67 wherein the analyte is nucleic acid. 70. The apparatus of claim 67 wherein the analytes are immobilized on one or more mobile solid supports that are disposed in the reaction chamber. 71. The apparatus of claim 67 wherein the processing reagents are immobilized on one or more mobile solid supports. 72. A method for sequencing a nucleic acid, the method comprising: (a) providing a plurality of single-stranded nucleic acid templates in an array having at least 50,000 discrete reaction sites; (b) contacting the nucleic acid templates with reagents necessary to perform a pyrophosphate-based sequencing reaction coupled to light emission; (c) detecting the light emitted from a plurality of reaction sites on respective portions of an optically sensitive device; (d) converting the light impinging upon each of said portions of said optically sensitive device into an electrical signal which is distinguishable from the signals from all of said other reaction sites; (e) determining the sequence of the nucleic acid templates based on light emission for each of said discrete reaction sites from the corresponding electrical signal. 73. The method of claim 1 further comprising the steps of: (a) uniquely tagging fragmented nucleic acids from different biological sources libraries to create libraries of fragmented nucleic acids with different detectable sequence tags; (b) sequencing said fragmented nucleic acids and detecting said detectable sequence tag from each said tagged nucleic acid fragment. 74. The method of claim 1 wherein the libraries are delivered individually or wherein the libraries are mixed and delivered simultaneously. 75. The method of claim 1 wherein said detectable sequence tag comprises an oligonucleotide of between 2 and 50 bases. 76. A method for sequencing nucleic acids comprising: (a) fragmenting large template nucleic acid molecules to generate a plurality of fragmented nucleic acids; (b) attaching one strand of a plurality of the fragmented nucleic acids individually to beads to generate single stranded nucleic acids attached individually to beads; (c) delivering a population of the single stranded fragmented nucleic acids attached individually to beads to an array of at least 10,000 reaction chambers on a planar surface, wherein a plurality of the wells comprise no more than a one bead with on single stranded fragmented nucleic acid; (d) performing a sequencing reaction simultaneously on a plurality of the reaction chambers. 77. The method of claim 76 wherein the reaction chambers have a center to center spacing of between 20 to 100 μm. 78. The method of claim 76 wherein the fragmented nucleic acids are between 30-500 bases. 79. The method of claim 76 wherein the fragmented nucleic acids are amplified in the reaction chambers prior to step (d). 80. The method of claim 76 wherein the amplifying step is accomplished using polymerase chain reaction. 81. The method of claim 76 wherein the sequencing reaction is a pyrophosphate-based sequencing reaction. 82. The method of claim 76 wherein the sequencing reaction comprises the steps of: (f) annealing an effective amount of a sequencing primer to the single stranded fragmented nucleic acid templates and extending the sequencing primer with a polymerase and a predetermined nucleotide triphosphate to yield a sequencing product and, if the predetermined nucleotide triphosphate is incorporated onto the 3′ end of said sequencing primer, a sequencing reaction byproduct; and (g) identifying the sequencing reaction byproduct, thereby determining the sequence of the nucleic acid in a plurality of the reaction chambers. 83. The method of claim 76 wherein the sequencing reaction comprises the steps of: (a) hybridizing two or more sequencing primers to one or a plurality of single strands of the nucleic acid molecule wherein all the primers except for one are reversibly blocked primers; (b) incorporating at least one base onto the nucleic acid molecule by polymerase elongation from an unblocked primer; (c) preventing further elongation of said unblocked primer; (d) deblocking one of the reversibly blocked primers into an unblocked primer; and (e) repeating steps (b) to (d) until at least one of the reversibly blocked primers are deblocked and used for determining a sequence. 84. The method of claim 76 wherein the reaction chambers are cavities formed by etching one end of a fiber optic bundle. | RELATED APPLICATIONS This application claims the benefit of priority to the following applications: U.S. Ser. No. 60/476,602, filed Jun. 6, 2003, entitled “Method For Preparing Single-Stranded DNA Libraries (21465-507 PRO)”, U.S. Ser. No. 60/476,504, filed Jun. 6, 2003, entitled “Bead Emulsion Nucleic Acid Amplification (21465-508 PRO)”, U.S. Ser. No. 60/443,471, filed Jan. 29, 2003, entitled “Double Ended Sequencing (21465-509 PROA)”, U.S. Ser. No. 60/476,313, filed Jun. 6, 2003, entitled “Double Ended Sequencing (21465-509 PROB)”, U.S. Ser. No. 60/476,592, filed Jun. 6, 2003, entitled “Methods Of Amplifying And Sequencing Nucleic Acids (21465-510 PRO A)”, U.S. Ser. No. 60/465,071, filed Apr. 23, 2003, entitled “Massively Parallel High Throughput, Low Cost Sequencing (21465-510 PRO B)”, and U.S. Ser. No. 60/497,985, filed Aug. 25, 2003, entitled “A Massively Parallel Picotiterplate-Based Platform For Discrete Picoliter-Scale Polymerase Chain Reactions (21465-510 PRO C).” This application incorporates by reference the following copending U.S. patent applications: application entitled “Method For Preparing Single-Stranded DNA Libraries (21465-507)”, filed Jan. 28, 2004, with a serial number to be assigned, application entitled “Bead Emulsion Nucleic Acid Amplification (21465-508)”, filed Jan. 28, 2004, with a serial number to be assigned, application entitled “Double Ended Sequencing (21465-509 PROA),” filed Jan. 28, 2004, with a serial number to be assigned, All patent and patent applications referred to in this application are hereby fully incorporated by reference. FIELD OF THE INVENTION This invention relates to a method and apparatus for determining the base sequences of DNA. More particularly, this invention relates to methods and an apparatus with which the base sequences of a genome can be amplified and determined automatically or semiautomatically. BACKGROUND OF THE INVENTION Development of rapid and sensitive nucleic acid sequencing methods utilizing automated DNA sequencers has revolutionized modern molecular biology. Analysis of entire genomes of plants, fungi, animals, bacteria, and viruses is now possible with a concerted effort by a series of machines and a team of technicians. However, the goal of rapid and automated or semiautomatic sequencing of a genome in a short time has not been possible. There continues to be technical problems for accurate sample preparation, amplification and sequencing. One technical problem which hinders sequence analysis of genomes has been the inability of the investigator to rapidly prepare numerous nucleic acid sample encompassing a complete genome in a short period of time. Another technical problem is the inability to representatively amplified a genome to a level that is compatible with the sensitivity of current sequencing methods. Modern economically feasible sequencing machines, while sensitive, still require in excess of one million copies of a DNA fragment for sequencing. Current methods for providing high copies of DNA sequencing involves variations of cloning or in vitro amplification which cannot amplify the number of individual clones (600,000 or more, and tens of millions for a human genome) necessary for sequencing a whole genome economically. Yet another technical problem in the limitation of current sequencing methods which can perform, at most, one sequencing reaction per hybridization of oligonucleotide primer. The hybridization of sequencing primers is often the rate limiting step constricting the throughput of DNA sequencers. In most cases, Polymerase Chain Reaction (PCR; Saiki, R. K., et al., Science 1985, 230, 1350-1354; Mullis, K., et al., Cold Spring Harb. Symp. Quant. Biol. 1986, 51 Pt 1, 263-273) plays an integral part in obtaining DNA sequence information, amplifying minute amounts of specific DNA to obtain concentrations sufficient for sequencing. Yet, scaling current PCR technology to meet the increasing demands of modern genetics is neither cost effective nor efficient, especially when the requirements for full genome sequencing are considered. Efforts to maximize time and cost efficiencies have typically focused on two areas: decreasing the reaction volume required for amplifications and increasing the number of simultaneous amplifications performed. Miniaturization confers the advantage of lowered sample and reagent utilization, decreased amplification times and increased throughput scalability. While conventional thermocyclers require relatively long cycling times due to thermal mass restrictions (Woolley, A. T., et al., Anal. Chem. 1996, 68, 4081-4086), smaller reaction volumes can be cycled more rapidly. Continuous flow PCR devices have utilized etched microchannels in conjunction with fixed temperature zones to reduce reaction volumes to sub-microliter sample levels (Lagally, E. T., et al., Analytical Chemistry 2001, 73, 565-570; Schneegas, I., et al., Lab on a Chip—The Royal Society of Chemistry 2001, 1, 42-49). Glass microcapillaries, heated by air (Kalinina, O., et al., Nucleic Acids Res. 1997, 25, 1999-2004) or infrared light (Oda, R. P., et al., Anal. Chem. 1998, 70, 4361-4368; Huhmer, A. F. and Landers, J. P., Anal. Chem. 2000, 72, 5507-5512), have also served as efficient vessels for nanoliter scale reactions. Similar reaction volumes have been attained with microfabricated silicon thermocyclers (Burns, M. A., et al., Proc. Natl. Acad. Sci. USA 1996, 93, 5556-5561). In many cases, these miniaturizations have reduced total PCR reaction times to less than 30 minutes for modified electric heating elements (Kopp, M. U., et al., Science 1998, 280, 1046-1048; Chiou, J., Matsudaira, P., Sonin, A. and Ehrlich, D., Anal. Chem. 2001, 73, 2018-2021) and hot air cyclers (Kalinina, O., et al., Nucleic Acids Res. 1997, 25, 1999-2004), and to 240 seconds for some infrared controlled reactions (Giordano, B. C., et al., Anal. Biochem. 2001, 291, 124-132). Certain technologies employ increased throughput and miniaturization simultaneously; as in the 1536-well system design by Sasaki et al. (Sasaki, N., et al., DNA Res. 1997, 4, 387-391), which maintained reaction volumes under 1 μl. As another example, Nagai et al. (Nagai, H., et al., Biosens. Bioelectron. 2001, 16, 1015-1019; Nagai, H., et al., Anal. Chem. 2001, 73, 1043-1047) reported amplification of a single test fragment in ten thousand 86 pl reaction pits etched in a single silicon wafer. Unfortunately, recovery and utilization of the amplicon from these methods have proven problematic, requiring evaporation through selectively permeable membranes. Despite these remarkable improvements in reactions volumes and cycle times, none of the previous strategies have provided the massively parallel amplification required to dramatically increase throughput to levels required for analysis of the entire human genome. DNA sequencers continue to be slower and more expensive than would be desired. In the pure research setting it is perhaps acceptable if a sequencer is slow and expensive. But when it is desired to use DNA sequencers in a clinical diagnostic setting such inefficient sequencing methods are prohibitive even for a well financed institution. The large-scale parallel sequencing of thousands of clonally amplified targets would greatly facilitate large-scale, whole genome library analysis without the time consuming sample preparation process and expensive, error-prone cloning processes. Successful high capacity, solid-phase, clonal DNA amplification can be used for numerous applications. Accordingly, it is clear that there exists a need for preparation of a genome or large template nucleic acids for sequencing, for amplification of the nucleic acid template, and for the sequencing of the amplified template nucleic acids without the constraint of one sequencing reaction per hybridization. Furthermore, there is a need for a system to connect these various technologies into a viable automatic or semiautomatic sequencing machine. BRIEF SUMMARY OF THE INVENTION This invention describes an integrated system, comprising novel methods and novel apparatus for (1) nucleic acid sample preparation, (2) nucleic acid amplification, and (3) DNA sequencing. The invention provides a novel method for preparing a library of multiple DNA sequences, particularly derived from large template DNA or whole (or partial) genome DNA. Sequences of single stranded DNA are prepared from a sample of large template DNA or whole or partial DNA genomes through fragmentation, polishing, adaptor ligation, nick repair, and isolation of single stranded DNA. The method provides for generating a ssDNA library linked to solid supports comprising: (a) generating a library of ssDNA templates; (b) attaching the ssDNA templates to solid supports; and (c) isolating the solid supports on which one ssDNA template is attached. The invention also provides for a method of amplifying each individual member of a DNA library in a single reaction tube, by, e.g., encapsulating a plurality of DNA samples individually in a microcapsule of an emulsion, performing amplification of the plurality of encapsulated nucleic acid samples simultaneously, and releasing said amplified plurality of DNA from the microcapsules for subsequent reactions. In one embodiment, single copies of the nucleic acid template species are hybridized to DNA capture beads, suspended in complete amplification solution and emulsified into microreactors (typically 100 to 200 microns in diameter), after which amplification (e.g., PCR) is used to clonally increase copy number of the initial template species to more than 1,000,000 copies of a single nucleic acid sequence, preferably between 2 and 20 million copies of a single nucleic acid. The amplification reaction, for example, may be performed simultaneously with at least 3,000 microreactors per microliter of reaction mix, and may be performed with over 300,000 microreactors in a single 100 μl volume test tube (e.g., a PCR reaction tube). The present invention also provides for a method of enriching for those beads that contains a successful DNA amplification event (i.e., by removing beads that have no DNA attached thereto). The invention also provides for a method of sequencing a nucleic acid from multiple primers with a single primer hybridization step. Two or more sequencing primers are hybridized to the template DNA to be sequenced. All the sequencing primers are then protected except for one. Sequencing (e.g., pyrophosphate sequencing) is performed again by elongating the unprotected primer. The elongation is either allowed to go to completion (with additional polymerase and dNTPs if necessary) or is terminated (by polymerase and ddNTPs). Chain completion and/or termination reagents are removed. Then one of the protected primers is unprotected and sequencing is performed by elongating the newly unprotected primer. This process is continued until all the sequencing primers are deprotected and sequenced. In a preferred embodiment, two primers (one protected and one unprotected) are used to sequence both ends of a double stranded nucleic acid. The invention also provides an apparatus and methods for sequencing nucleic acids using a pyrophosphate based sequencing approach. The apparatus has a charge coupled device (CCD) camera, microfluidics chamber, sample cartridge holder, pump and flow valves. The apparatus uses chemiluminescence as the detection method, which for pyrophosphate sequencing has an inherently low background. In a preferred embodiment, the sample cartridge for sequencing is termed the ‘PicoTiter plate,’ and is formed from a commercial fiber optics faceplate, acid-etched to yield hundreds of thousands of very small wells, each well volume of 75 pL. The apparatus includes a novel reagent delivery cuvette adapted for use with the arrays described herein, to provide fluid reagents to the picotiter plate, and a reagent delivery means in communication with the reagent delivery cuvette. Photons from each well on the picotiter plate are channeled into specific pixels on the CCD camera to detect sequencing reactions. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 depicts a schematic representation of the entire process of library preparation including the steps of template DNA fragmentation (FIG. 1A), end polishing (FIG. 1B), adaptor ligation (FIG. 1C), nick repair, strand extension and gel isolation (FIG. 1D). FIG. 1E depicts a schematic representation of the stages for amplification and sequencing of template DNA (FIG. 1E). FIG. 1F depicts a representative agarose gel containing a sample preparation of a 180-350 base pair adenovirus DNA library according to the methods of this invention. FIG. 1G depicts a detailed schematic representation of library preparation, amplification, and sequencing. FIG. 2A depicts a schematic representation of the universal adaptor design according to the present invention. Each universal adaptor is generated from two complementary ssDNA oligonucleotides that are designed to contain a 20 bp nucleotide sequence for PCR priming, a 20 bp nucleotide sequence for sequence priming and a unique 4 bp discriminating sequence comprised of a non-repeating nucleotide sequence (i.e., ACGT, CAGT, etc.). FIG. 2B depicts a representative universal adaptor sequence pair for use with the invention. Adaptor A sense strand: SEQ ID NO:1; Adaptor A antisense strand: SEQ ID NO:2; Adaptor B sense strand: SEQ ID NO:3; Adaptor B antisense strand: SEQ ID NO:4. FIG. 2C depicts a schematic representation of universal adaptor design for use with the invention. FIG. 3 depicts the strand displacement and extension of nicked double-stranded DNA fragments according to the present invention. Following the ligation of universal adaptors generated from synthetic oligonucleotides, double-stranded DNA fragments will be generated that contain two nicked regions following T4 DNA ligase treatment (FIG. 3A). The addition of a strand displacing enzyme (i.e., Bst DNA polymerase I) will bind nicks (FIG. 3B), strand displace the nicked strand and complete nucleotide extension of the strand (FIG. 3C) to produce non-nicked double-stranded DNA fragments (FIG. 3D). FIG. 4 depicts the isolation of directionally-ligated single-stranded DNA according to the present invention using streptavidin-coated beads. Following ligation with universal adaptors A and B (the two different adaptors are sometimes referred to as a “first” and “second” universal adaptor), double-stranded DNA will contain adaptors in four possible combinations: AA, BB, AB and BA. When universal adaptor B contains a 5′-biotin, magnetic streptavidin-coated solid supports are used to capture and isolate the AB, BA and BB populations (population AA is washed away). The BB population is retained on the beads as each end of the double-stranded DNA is attached to a bead and is not released. However, upon washing in the presence of a low salt buffer, only populations AB and BA will release a single-stranded DNA fragment that is complementary to the bound strand. Single-stranded DNA fragments are isolated from the supernatant and used as template for subsequent amplification and sequencing. This method is described below in more detail. FIG. 5 depicts a schematic of the structure of a DNA capture bead. FIG. 6 depicts a schematic of one embodiment of a bead emulsion amplification process. FIG. 7 depicts a schematic of an enrichment process to remove beads that do not have any DNA attached thereto. FIGS. 8A-B depict a schematic representation of the double ended sequencing reaction according to the present invention. FIG. 9 depicts a double-ended sequencing demonstration on a pyrosequencing apparatus according to the invention. FIGS. 10A-F depict an exemplary double ended sequencing process. FIGS. 11A-D depict schematic illustrations of rolling circle-based amplification using an anchor primer. FIG. 12 depicts a drawing of a sequencing apparatus according to the present invention. FIG. 13 depicts a drawing of a reagent delivery/perfusion chamber according to the present invention. FIG. 14 depicts a micrograph of a cavitated fiber optic bundle, termed a PicoTiter Plate™, of the invention. FIG. 15 depicts a micrograph of a picotiter plate carpeted with beads having DNA template immobilized thereon and sulfurylase and luciferase immobilized thereon. FIG. 16 depicts a schematic illustration of the reagent flow chamber and FORA (PicoTiter Plate™). FIG. 17 depicts a diagram of the analytical instrument of the present invention. FIG. 18 depicts a schematic illustration of microscopic parallel sequencing reactions within a PicoTiter Plate™. FIG. 19 depicts a micrograph of single well reactions. FIG. 20 depicts a PicoTiterPlate™ loading cartridge. “A” refers to a PicoTiterPlate™ with microwells facing into the cartridge, the distance between the open sides of the PicoTiterPlate™ wells and the wall of the loading cartridge is 0.3 mm; “B” refers to a silicon sealing gasket; “C” refers to an inlet port; “D” refers to an inlet loading tube; “E” refers to an outlet port and “F” refers to an outlet tube. The PicoTiterPlate™ is held in the cartridge with plastic clamps. The liquid is filled via the inlet loading tube D and enters the space between the open sides of the PicoTiterPlate™ wells and the wall of the laoding cartridge through the inlet port C. The area defined by the silicon sealing gasket B is filled and excess liquid leaves the cartridge via the outlet port E and the outlet tubing F. FIG. 21 depicts a PicoTiterPlate™ amplification chamber in exploded view. “A” refers to an amplification chamber lid with six retaining bolts; “B” refers to a closed cell foam insulation pad; “C” refers to a 25 mm by 75 mm standard glass microscope slide; “D” refers to a 0.25 mm thick silicon sheet; “E” refers to a PicoTiterPlate™; “F” refers to an amplification chamber base; “G” refers to a second 0.25 mm thick silicon sheet. FIG. 22 depicts a schematic diagram of solid phase PicoTiterPlate™ PCR. The cylindrical structures symbolize individual PicoTiterPlate™ wells. Gray spheres symbolize beads with immobilized primers. Forward “F” (red) and Reverse “R” (blue) primers are shown in 5′ to 3′ orientation as indicated by arrows. Synthesized sequence complementary to the Forward and Reverse primers are shown as dark red (F complement) and dark blue (R complement) bars. Single stranded template DNA is shown as solid gray line, newly synthesized DNA strands as dashed gray lines. Fluorescently labeled hybridization probes are shown as green bars. FIGS. 23A-C depict fluorescent probes hybridization to bead-immobilized test DNA fragments. FIG. 23A (upper left) and 23B (upper right) illustrate the specificity of a mixed population of probes hybridized to fragment A and fragment B immobilized on control beads, respectively. Fragment B beads exhibited the Alexa Fluor 647 signal (red), and the fragment A beads exhibited the Alexa Fluor 488 signal (green). FIG. 23C (bottom panel) depicts probe fluorescence from DNA capture beads after PTPCR. Beads displayed homogenous fragment A and fragment B signals, as well as mixes of templates, shown as varying degrees of yellow. FIG. 24 depicts representative BioAnalyzer output from analysis of a single stranded DNA library. FIG. 25 depicts an insert flanked by PCR primers and sequencing primers. FIG. 26 depicts truncated product produced by PCR primer mismatch at cross-hybridization region (CHR). FIG. 27 depicts the calculation for primer candidates based on melting temperature. FIGS. 28A-D depict the assembly for the nebulizer used for the methods of the invention. A tube cap was placed over the top of the nebulizer (FIG. 7A) and the cap was secured with a nebulizer clamp assembly (FIG. 7B). The bottom of the nebulizer was attached to the nitrogen supply (FIG. 7C) and the entire device was wrapped in parafilm (FIG. 7D). FIG. 29A depicts representative results for LabChip analysis of a single stranded DNA library following nebulization and polishing. FIG. 29B depicts representative size distribution results for an adaptor-ligated single stranded DNA library following nebulization, polishing, and gel purification. FIG. 30 depiction of jig used to hold tubes on the stir plate below vertical syringe pump. The jig was modified to hold three sets of bead emulsion amplification reaction mixtures. The syringe was loaded with the PCR reaction mixture and beads. FIG. 31 depiction of optimal placement of syringes in vertical syringe pump and orientation of emulsion tubes below syringe outlets. FIG. 32 depiction of optimal placement of syringe pump pusher block against syringe plungers, and optimal orientation of jig on the stir plate. Using this arrangement, the syringe contents were expelled into the agitated emulsion oil. FIG. 33 depiction of beads (see arrows) suspended in individual microreactors according to the methods of the invention. FIG. 34 depiction of double ended sequencing results showing that the sequence of both ends of a DNA template are determined. SEQ ID NO:44: atgcacatggttgacacagtggt; SEQ ID NO:45: atgcacatggttgacacagtgg; SEQ ID NO:46: atgccaccgacctagtctcaaactt. FIG. 35 illustrates the encapsulation of a bead comprising two oligonucleotide sequences for double stranded sequencing. FIG. 36 illustrates solution phase PCR and drive to bead procedure—a step in a preferred embodiment of double ended sequencing. FIG. 37 illustrates emulsion breaking and recovery of amplified template DNA on a bead—a step in a preferred embodiment of double ended sequencing. FIG. 38 depicts a schematic representation of a preferred method of double stranded sequencing. FIG. 39 illustrates the results of sequencing a Staphylococcus aureus genome. FIG. 40 illustrates the average read lengths in one experiment involving double ended sequencing. FIG. 41 illustrates the number of wells for each genome span in a double ended sequencing experiment. FIG. 42 illustrates a typical output and alignment string from a double ended sequencing procedure. Sequences shown in order, from top to bottom: SEQ ID NO:47-SEQ ID NO:60. DETAILED DESCRIPTION OF THE INVENTION A novel platform is described herein which permits simultaneous amplification of three hundred thousand discrete PCR reactions (PTPCR) in volumes as low as 39.5 picoliters. The pooled PTPCR products from the entire reaction can be recovered through a wash step and assayed via real-time PCR for the presence and abundance of specific templates. Of greater interest, it is shown herein that these PTPCR products can be driven to solid supports and detected by hybridization with two color fluorescent probes, allowing high capacity, solid-phase, clonal DNA amplification and large-scale parallel sequencing. The present invention is directed to a method and apparatus for performing genomic sequencing which satisfies the objectives of (1) preparing a nucleic acid (e.g., a genome) in a rapid and efficient manner for sequencing, (2) amplifying the nucleic acid in a representative manner, and (3) performing multiple sequencing reactions with only one primer hybridization. The present invention is particularly suited for genotyping, detection and diagnosis from a small sample of nucleic acid in a cost efficient manner. Each of these objectives are listed below. Definitions: Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Methods and materials similar or equivalent to those described herein can be used in the practice of the present invention, and exemplified suitable methods and materials are described below. For example, methods may be described which comprise more than two steps. In such methods, not all steps may be required to achieve a defined goal and the invention envisions the use of isolated steps to achieve these discrete goals. The disclosures of all publications, patent applications, patents and other references are incorporated in toto herein by reference. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. As used herein, the term “universal adaptor” refers to two complementary and annealed oligonucleotides that are designed to contain a nucleotide sequence for PCR priming and a nucleotide sequence for sequence priming. Optionally, the universal adaptor may further include a unique discriminating key sequence comprised of a non-repeating nucleotide sequence (i.e., ACGT, CAGT, etc.). A set of universal adaptors comprises two unique and distinct double-stranded sequences that can be ligated to the ends of double-stranded DNA. Therefore, the same universal adaptor or different universal adaptors can be ligated to either end of the DNA molecule. When comprised in a larger DNA molecule that is single stranded or when present as an oligonucleotide, the universal adaptor may be referred to as a single stranded universal adaptor. “Target DNA” shall mean a DNA whose sequence is to be determined by the methods and apparatus of the invention. Binding pair shall mean a pair of molecules that interact by means of specific non-covalent interactions that depend on the three-dimensional structures of the molecules involved. Typical pairs of specific binding partners include antigen-antibody, hapten-antibody, hormone-receptor, nucleic acid strand-complementary nucleic acid strand, substrate-enzyme, substrate analog-enzyme, inhibitor-enzyme, carbohydrate-lectin, biotin-avidin, and virus-cellular receptor. As used herein, the term “discriminating key sequence” refers to a sequence consisting of at least one of each of the four deoxyribonucleotides (i.e., A, C, G, T). The same discriminating sequence can be used for an entire library of DNA fragments. Alternatively, different discriminating key sequences can be used to track libraries of DNA fragments derived from different organisms. As used herein, the term “plurality of molecules” refers to DNA isolated from the same source, whereby different organisms may be prepared separately by the same method. In one embodiment, the plurality of DNA samples is derived from large segments of DNA, whole genome DNA, cDNA, viral DNA or from reverse transcripts of viral RNA. This DNA may be derived from any source, including mammal (i.e., human, nonhuman primate, rodent or canine), plant, bird, reptile, fish, fungus, bacteria or virus. As used herein, the term “library” refers to a subset of smaller sized DNA species generated from a single DNA template, either segmented or whole genome. As used herein, the term “unique”, as in “unique PCR priming regions” refers to a sequence that does not exist or exists at an extremely low copy level within the DNA molecules to be amplified or sequenced. As used herein, the term “compatible” refers to an end of double stranded DNA to which an adaptor molecule may be attached (i.e., blunt end or cohesive end). As used herein, the term “fragmenting” refers to a process by which a larger molecule of DNA is converted into smaller pieces of DNA. As used herein, “large template DNA” would be DNA of more than 25 kb, preferably more than 500 kb, more preferably more than 1 MB, and most preferably 5 MB or larger. As used herein, the term “stringent hybridization conditions” refers to those conditions under which only complimentary sequences will hybridize to each other. The invention described here is generally a system and methods for processing nucleic acids. The system and methods can be used to process nucleic acids in a multitude of ways that utilize sequencing of nucleic acids. Such sequencing can be performed to determine the identity of a sequence of nucleic acids, or for single nucleotide polymorphism detection in nucleic acid fragments, for nucleic acid expression profiling (comparing the nucleic acid expression profile between two or more states—e.g., comparing between diseased and normal tissue or comparing between untreated tissue and tissue treated with drug, enzymes, radiation or chemical treatment), for haplotying (comparing genes or variations in genes on each of the two alleles present in a human subject), for karyotyping (diagnostically comparing one or more genes in a test tissue—typically from an embryo/fetus prior to conception to detect birth defects—with the same genes from “normal” karyotyped subjects), and for genotyping (comparing one or more genes in a first individual of a species with the same genes in other individuals of the same species). The system has a number of components. These include (1) the nucleic acid template that is to be processed, (2) a picotiter plate for containing the nucleic acid template, (3) a flow chamber and fluid delivery means that permits flow of nucleic acid processing reagents over the nucleic acid template where the processing reagents generate light as the nucleic acid is processed, (4) a light capture means that detects light emitted as the nucleic acid is processed and that converts the captured light into data, and (5) data processing means that processes the data to yield meaningful information about the nucleic acid that has been processed. Each of these components of the system will be discussed in detail below. 1. Nucleic Acid Template and Preparation Thereof Nucleic Acid Templates The nucleic acid templates that can be sequenced according to the invention, e.g., a nucleic acid library, in general can include open circular or closed circular nucleic acid molecules. A “closed circle” is a covalently closed circular nucleic acid molecule, e.g., a circular DNA or RNA molecule. An “open circle” is a linear single-stranded nucleic acid molecule having a 5′ phosphate group and a 3′ hydroxyl group. In one embodiment, the single stranded nucleic acid contains at least 100 copies of a specific nucleic acid sequence, each copy covalently linked end to end. In some embodiments, the open circle is formed in situ from a linear double-stranded nucleic acid molecule. The ends of a given open circle nucleic acid molecule can be ligated by DNA ligase. Sequences at the 5′ and 3′ ends of the open circle molecule are complementary to two regions of adjacent nucleotides in a second nucleic acid molecule, e.g., an adapter region of an anchor primer (sometimes referred to as an adapter), or to two regions that are nearly adjoining in a second DNA molecule. Thus, the ends of the open-circle molecule can be ligated using DNA ligase, or extended by DNA polymerase in a gap-filling reaction. Open circles are described in detail in Lizardi, U.S. Pat. No. 5,854,033, fully incorporated herein by reference. An open circle can be converted to a closed circle in the presence of a DNA ligase (for DNA) or RNA ligase following, e.g., annealing of the open circle to an anchor primer. If desired, nucleic acid templates can be provided as padlock probes. Padlock probes are linear oligonucleotides that include target-complementary sequences located at each end, and which are separated by a linker sequence. The linkers can be ligated to ends of members of a library of nucleic acid sequences that have been, e.g., physically sheared or digested with restriction endonucleases. Upon hybridization to a target-sequence, the 5′- and 3′-terminal regions of these linear oligonucleotides are brought in juxtaposition. This juxtaposition allows the two probe segments (if properly hybridized) to be covalently-bound by enzymatic ligation (e.g., with T4 DNA ligase), thus converting the probes to circularly-closed molecules which are catenated to the specific target sequences (see e.g., Nilsson, et al., 1994. Science 265: 2085-2088). The resulting probes are suitable for the simultaneous analysis of many gene sequences both due to their specificity and selectivity for gene sequence variants (see e.g., Lizardi, et al., 1998. Nat. Genet. 19: 225-232; Nilsson, et al., 1997. Nat. Genet. 16: 252-255) and due to the fact that the resulting reaction products remain localized to the specific target sequences. Moreover, intramolecular ligation of many different probes is expected to be less susceptible to non-specific cross-reactivity than multiplex PCR-based methodologies where non-cognate pairs of primers can give rise to irrelevant amplification products (see e.g., Landegren and Nilsson, 1997. Ann. Med. 29: 585-590). A starting nucleic acid template library can be constructed comprising either single-stranded or double-stranded nucleic acid molecules, provided that the nucleic acid sequence includes a region that, if present in the library, is available for annealing, or can be made available for annealing, to an anchor primer sequence. For example, when used as a template for rolling circle amplification, a region of a double-stranded template needs to be at least transiently single-stranded in order to act as a template for extension of the anchor primer. Library templates can include multiple elements, including, but not limited to, one or more regions that are complementary to the anchor primer. For example, the template libraries may include a region complementary to a sequencing primer, a control nucleotide region, and an insert sequence comprised of the sequencing template to be subsequently characterized. As is explained in more detail below, the control nucleotide region is used to calibrate the relationship between the amount of byproduct and the number of nucleotides incorporated. As utilized herein the term “complement” refers to nucleotide sequences that are able to hybridize to a specific nucleotide sequence to form a matched duplex. In one embodiment, a library template includes: (i) two distinct regions that are complementary to the anchor primer, (ii) one region homologous to the sequencing primer, (iii) one optional control nucleotide region, (iv) an insert sequence of, e.g., 30-500, 50-200, or 60-100 nucleotides, that is to be sequenced. The template can, of course, include two, three, or all four of these features. The template nucleic acid can be constructed from any source of nucleic acid, e.g., any cell, tissue, or organism, and can be generated by any art-recognized method. Suitable methods include, e.g., sonication of genomic DNA and digestion with one or more restriction endonucleases (RE) to generate fragments of a desired range of lengths from an initial population of nucleic acid molecules. Preferably, one or more of the restriction enzymes have distinct four-base recognition sequences. Examples of such enzymes include, e.g., Sau3A1, MspI, and TaqI. Preferably, the enzymes are used in conjunction with anchor primers having regions containing recognition sequences for the corresponding restriction enzymes. In some embodiments, one or both of the adapter regions of the anchor primers contain additional sequences adjoining known restriction enzyme recognition sequences, thereby allowing for capture or annealing to the anchor primer of specific restriction fragments of interest to the anchor primer. In other embodiments, the restriction enzyme is used with a type IIS restriction enzyme. Alternatively, template libraries can be made by generating a complementary DNA (cDNA) library from RNA, e.g., messenger RNA (mRNA). The cDNA library can, if desired, be further processed with restriction endonucleases to obtain a 3′ end characteristic of a specific RNA, internal fragments, or fragments including the 3′ end of the isolated RNA. Adapter regions in the anchor primer may be complementary to a sequence of interest that is thought to occur in the template library, e.g., a known or suspected sequence polymorphism within a fragment generated by endonuclease digestion. In one embodiment, an indexing oligonucleotide can be attached to members of a template library to allow for subsequent correlation of a template nucleic acid with a population of nucleic acids from which the template nucleic acid is derived. For example, one or more samples of a starting DNA population can be fragmented separately using any of the previously disclosed methods (e.g., restriction digestion, sonication). An indexing oligonucleotide sequence specific for each sample is attached to, e.g., ligated to, the termini of members of the fragmented population. The indexing oligonucleotide can act as a region for circularization, amplification and, optionally, sequencing, which permits it to be used to index, or code, a nucleic acid so as to identify the starting sample from which it is derived. Distinct template libraries made with a plurality of distinguishable indexing primers can be mixed together for subsequent reactions. Determining the sequence of the member of the library allows for the identification of a sequence corresponding to the indexing oligonucleotide. Based on this information, the origin of any given fragment can be inferred. The invention includes a sample preparation process that results in a solid or a mobile solid substrate array containing a plurality of anchor primers or adapaters covalently linked to template nucleic acids. When the template nucleic acid is circular, formation of the covalently linked anchor primer and one or more copies of the target nucleic acid preferably occurs by annealing the anchor primer to a complementary region of a circular nucleic acid, and then extending the annealed anchor primer with a polymerase to result in formation of a nucleic acid containing one or more copies of a sequence complementary to the circular nucleic acid. Attachment of the anchor primer to a solid or mobile solid substrate can occur before, during, or subsequent to extension of the annealed anchor primer. Thus, in one embodiment, one or more anchor primers are linked to the solid or a mobile solid substrate, after which the anchor primer is annealed to a target nucleic acid and extended in the presence of a polymerase. Alternatively, in a second embodiment, an anchor primer is first annealed to a target nucleic acid, and a 3′OH terminus of the annealed anchor primer is extended with a polymerase. The extended anchor primer is then linked to the solid or mobile solid substrate. By varying the sequence of anchor primers, it is possible to specifically amplify distinct target nucleic acids present in a population of nucleic acids. Outlined below is a preferred embodiment for the preparation of template nucleic acids for amplification and sequencing reactions. The invention includes a method for preparing the sample DNA comprised of seven general steps: (a) fragmenting large template DNA or whole genomic DNA samples to generate a plurality of digested DNA fragments; (b) creating compatible ends on the plurality of digested DNA samples; (c) ligating a set of universal adaptor sequences onto the ends of fragmented DNA molecules to make a plurality of adaptor-ligated DNA molecules, wherein each universal adaptor sequence has a known and unique base sequence comprising a common PCR primer sequence, a common sequencing primer sequence and a discriminating four base key sequence and wherein one adaptor is attached to biotin; (d) separating and isolating the plurality of ligated DNA fragments; (e) removing any portion of the plurality of ligated DNA fragments; (f) nick repair and strand extension of the plurality of ligated DNA fragments; (g) attaching each of the ligated DNA fragments to a solid support; and (h) isolating populations comprising single-stranded adaptor-ligated DNA fragments for which there is a unique adaptor at each end (i.e., providing directionality). The following discussion summarizes the basic steps involved in the methods of the invention. The steps are recited in a specific order, however, as would be known by one of skill in the art, the order of the steps may be manipulated to achieve the same result. Such manipulations are contemplated by the inventors. Further, some steps may be minimized as would also be known by one of skill in the art. Fragmentation In the practice of the methods of the present invention, the fragmentation of the DNA sample can be done by any means known to those of ordinary skill in the art. Preferably, the fragmenting is performed by enzymatic or mechanical means. The mechanical means may be sonication or pnysical shearing. The enzymatic means may be performed by digestion with nucleases (e.g., Deoxyribonuclease I (DNase I)) or one or more restriction endonucleases. In a preferred embodiment, the fragmentation results in ends for which the sequence is not known. In a preferred embodiment, the enzymatic means is DNase I. DNase I is a versatile enzyme that nonspecifically cleaves double-stranded DNA (dsDNA) to release 5′-phosphorylated di-, tri-, and oligonucleotide products. DNase I has optimal activity in buffers containing Mn, Mg and Ca2+, but no other salts. The purpose of the DNase I digestion step is to fragment a large DNA genome into smaller species comprising a library. The cleavage characteristics of DNase I will result in random digestion of template DNA (i.e., no sequence bias) and in the predominance of blunt-ended dsDNA fragments when used in the presence of manganese-based buffers (Melgar, E. and D. A. Goldthwait. 1968. Deoxyribonucleic acid nucleases. II. The effects of metal on the mechanism of action of deoxyribonuclease I. J. Biol. Chem. 243: 4409). The range of digestion products generated following DNase I treatment of genomic templates is dependent on three factors: i) amount of enzyme used (units); ii) temperature of digestion (° C.); and iii) incubation time (minutes). The DNase I digestion conditions outlined below have been optimized to yield genomic libraries with a size range from 50-700 base pairs (bp). In a preferred embodiment, the DNase I digests large template DNA or whole genome DNA for 1-2 minutes to generate a population of polynucleotides. In another preferred embodiment, the DNase I digestion is performed at a temperature between 10° C.-37° C. In yet another preferred embodiment, the digested DNA fragments are between 50 bp to 700 bp in length. Polishing Digestion of genomic DNA (gDNA) templates with DNase I in the presence of Mn2+ will yield fragments of DNA that are either blunt-ended or have protruding termini with one or two nucleotides in length. In a preferred embodiment, an increased number of blunt ends are created with Pfu DNA polymerase. In other embodiments, blunt ends can be created with less efficient DNA polymerases such as T4 DNA polymerase or Klenow DNA polymerase. Pfu “polishing” or blunt ending is used to increase the amount of blunt-ended species generated following genomic template digestion with DNase I. Use of Pfu DNA polymerase for fragment polishing will result in the fill-in of 5′ overhangs. Additionally, Pfu DNA polymerase does not exhibit DNA extendase activity but does have 3′→5′ exonuclease activity that will result in the removal of single and double nucleotide extensions to further increase the amount of blunt-ended DNA fragments available for adaptor ligation (Costa, G. L. and M. P. Weiner. 1994a. Protocols for cloning and analysis of blunt-ended PCR-generated DNA fragments. PCR Methods Appl 3(5):S95; Costa, G. L., A. Grafsky and M. P. Weiner. 1994b. Cloning and analysis of PCR-generated DNA fragments. PCR Methods Appl 3(6):338; Costa, G. L. and M. P. Weiner. 1994c. Polishing with T4 or Pfu polymerase increases the efficiency of cloning of PCR products. Nucleic Acids Res. 22(12):2423). Adaptor Ligation If the libraries of nucleic acids are to be attached to the solid substrate, then preferably the nucleic acid templates are annealed to anchor primer sequences using recognized techniques (see, e.g., Hatch, et al., 1999. Genet. Anal. Biomol. Engineer. 15: 35-40; Kool, U.S. Pat. No. 5,714,320 and Lizardi, U.S. Pat. No. 5,854,033). In general, any procedure for annealing the anchor primers to the template nucleic acid sequences is suitable as long as it results in formation of specific, i.e., perfect or nearly perfect, complementarity between the adapter region or regions in the anchor primer sequence and a sequence present in the template library. In a preferred embodiment, following fragmentation and blunt ending of the DNA library, universal adaptor sequences are added to each DNA fragment. The universal adaptors are designed to include a set of unique PCR priming regions that are typically 20 bp in length located adjacent to a set of unique sequencing priming regions that are typically 20 bp in length optionally followed by a unique discriminating key sequence consisting of at least one of each of the four deoxyribonucleotides (i.e., A, C, G, T). In a preferred embodiment, the discriminating key sequence is 4 bases in length. In another embodiment, the discriminating key sequence may be combinations of 1-4 bases. In yet another embodiment, each unique universal adaptor is forty-four bp (44 bp) in length. In a preferred embodiment the universal adaptors are ligated, using T4 DNA ligase, onto each end of the DNA fragment to generate a total nucleotide addition of 88 bp to each DNA fragment. Different universal adaptors are designed specifically for each DNA library preparation and will therefore provide a unique identifier for each organism. The size and sequence of the universal adaptors may be modified as would be apparent to one of skill in the art. For example, to prepare two distinct universal adaptors (i.e., “first” and “second”), single-stranded oligonucleotides may be ordered from a commercial vendor (i.e., Integrated DNA Technologies, IA or Operon Technologies, CA). In one embodiment, the universal adaptor oligonucleotide sequences are modified during synthesis with two or three phosphorothioate linkages in place of phosphodiester linkages at both the 5′ and 3′ ends. Unmodified oligonucleotides are subject to rapid degradation by nucleases and are therefore of limited utility. Nucleases are enzymes that catalyze the hydrolytic cleavage of a polynucleotide chain by cleaving the phosphodiester linkage between nucleotide bases. Thus, one simple and widely used nuclease-resistant chemistry available for use in oligonucleotide applications is the phosphorothioate modification. In phosphorothioates, a sulfur atom replaces a non-bridging oxygen in the oligonucleotide backbone making it resistant to all forms of nuclease digestion (i.e. resistant to both endonuclease and exonuclease digestion). Each oligonucleotide is HPLC-purified to ensure there are no contaminating or spurious oligonucleotide sequences in the synthetic oligonucleotide preparation. The universal adaptors are designed to allow directional ligation to the blunt-ended, fragmented DNA. Each set of double-stranded universal adaptors are designed with a PCR priming region that contains noncomplementary 5′ four-base overhangs that cannot ligate to the blunt-ended DNA fragment as well as prevent ligation with each other at these ends. Accordingly, binding can only occur between the 3′ end of the adaptor and the 5′ end of the DNA fragment or between the 3′ end of the DNA fragment and the 5′ end of the adaptor. Double-stranded universal adaptor sequences are generated by using single-stranded oligonucleotides that are designed with sequences that allow primarily complimentary oligonucleotides to anneal, and to prevent cross-hybridization between two non-complimentary oligonucleotides. In one embodiment, 95% of the universal adaptors are formed from the annealing of complimentary oligonucleotides. In a preferred embodiment, 97% of the universal adaptors are formed from the annealing of complimentary oligonucleotides. In a more preferred embodiment, 99% of the universal adaptors are formed from the annealing of complimentary oligonucleotides. In a most preferred embodiment, 100% of the universal adaptors are formed from the annealing of complimentary oligonucleotides. One of the two adaptors can be linked to a support binding moiety. In a preferred embodiment, a 5′ biotin is added to the first universal adaptor to allow subsequent isolation of ssDNA template and noncovalent coupling of the universal adaptor to the surface of a solid support that is saturated with a biotin-binding protein (i.e. streptavidin, neutravidin or avidin). Other linkages are well known in the art and may be used in place of biotin-streptavidin (for example antibody/antigen-epitope, receptor/ligand and oligonucleotide pairing or complimentarily) one embodiment, the solid support is a bead, preferably a polystyrene bead. In one preferred embodiment, the bead has a diameter of about 2.8 μm. As used herein, this bead is referred to as a “sample prep bead”. Each universal adaptor may be prepared by combining and annealing two ssDNA oligonucleotides, one containing the sense sequence and the second containing the antisense (complementary) sequence. Schematic representation of the universal adaptor design is outlined in FIG. 2. Isolation of Ligation Products The universal adaptor ligation results in the formation of fragmented DNAs with adaptors on each end, unbound single adaptors, and adaptor dimers. In a preferred embodiment, agarose gel electrophoresis is used as a method to separate and isolate the adapted DNA library population from the unligated single adaptors and adaptor dimer populations. In other embodiments, the fragments may be separated by size exclusion chromatography or sucrose sedimentation. The procedure of DNase I digestion of DNA typically yields a library population that ranges from 50-700 bp. In a preferred embodiment, upon conducting agarose gel electrophoresis in the presence of a DNA marker, the addition of the 88 bp universal adaptor set will shift the DNA library population to a larger size and will result in a migration profile in the size range of approximately 130-800 bp; adaptor dimers will migrate at 88 bp; and adaptors not ligated will migrate at 44 bp. Therefore, numerous double-stranded DNA libraries in sizes ranging from 200-800 bp can be physically isolated from the agarose gel and purified using standard gel extraction techniques. In one embodiment, gel isolation of the adapted ligated DNA library will result in the recovery of a library population ranging in size from 200-400 bp. Other methods of distinguishing adaptor-ligated fragments are known to one of skill in the art. Nick Repair Because the DNA oligonucleotides used for the universal adaptors are not 5′ phosphorylated, gaps will be present at the 3′ junctions of the fragmented DNAs following ligase treatment (see FIG. 3A). These two “gaps” or “nicks” can be filled in by using a DNA polymerase enzyme that can bind to, strand displace and extend the nicked DNA fragments. DNA polymerases that lack 3′→5′ exonuclease activity but exhibit 5′→3′ exonuclease activity have the ability to recognize nicks, displace the nicked strands, and extend the strand in a manner that results in the repair of the nicks and in the formation of non-nicked double-stranded DNA (see FIGS. 3B and 3C) (Hamilton, S. C., J. W. Farchaus and M. C. Davis. 2001. DNA polymerases as engines for biotechnology. BioTechniques 31:370). Several modifying enzymes are utilized for the nick repair step, including but not limited to polymerase, ligase and kinase. DNA polymerases that can be used for this application include, for example, E. coli DNA pol I, Thermoanaerobacter thermohydrosulfuricus pol I, and bacteriophage phi 29. In a preferred embodiment, the strand displacing enzyme Bacillus stearothermophilus pol I (Bst DNA polymerase I) is used to repair the nicked dsDNA and results in non-nicked dsDNA (see FIG. 3D). In another preferred embodiment, the ligase is T4 and the kinase is polynucleotide kinase. Isolation of Single-Stranded DNA Following the generation of non-nicked dsDNA, ssDNAs comprising both the first and second adaptor molecules are to be isolated (desired populations are designated below with asterisks; “A” and “B” correspond to the first and second adaptors). Double-stranded DNA libraries will have adaptors bound in the following configurations: Universal Adaptor A-DNA fragment-Universal Adaptor A Universal Adaptor B—DNA fragment-Universal Adaptor A* Universal Adaptor A-DNA fragment-Universal Adaptor B* Universal Adaptor B-DNA fragment-Universal Adaptor B Universal adaptors are designed such that only one universal adaptor has a 5′ biotin moiety. For example, if universal adaptor B has a 5′biotin moiety, streptavidin-coated sample prep beads can be used to bind all double-stranded DNA library species with universal adaptor B. Genomic library populations that contain two universal adaptor A species will not contain a 5′ biotin moiety and will not bind to streptavidin-containing sample prep beads and thus can be washed away. The only species that will remain attached to beads are those with universal adaptors A and B and those with two universal adaptor B sequences. DNA species with two universal adaptor B sequences (i.e., biotin moieties at each 5′end) will be bound to streptavidin-coated sample prep beads at each end, as each strand comprised in the double strand will be bound. Double-stranded DNA species with a universal adaptor A and a universal adaptor B will contain a single 5′biotin moiety and thus will be bound to streptavidin-coated beads at only one end. The sample prep beads are magnetic, therefore, the sample prep beads will remain coupled to a solid support when magnetized. Accordingly, in the presence of a low-salt (“melt” or denaturing) solution, only those DNA fragments that contain a single universal adaptor A and a single universal adaptor B sequence will release the complementary unbound strand. This single-stranded DNA population may be collected and quantitated by, for example, pyrophosphate sequencing, real-time quantitative PCR, agarose gel electrophoresis or capillary gel electrophoresis. Attachment of Template to Beads In one embodiment, ssDNA libraries that are created according to the methods of the invention are quantitated to calculate the number of molecules per unit volume. These molecules are annealed to a solid support (bead) that contain oligonucleotide capture primers that are complementary to the PCR priming regions of the universal adaptor ends of the ssDNA species. Beads are then transferred to an amplification protocol. Clonal populations of single species captured on DNA beads may then sequenced. In one embodiment, the solid support is a bead, preferably a sepharose bead. As used herein, this bead is referred to as a “DNA capture bead”. The beads used herein may be of any convenient size and fabricated from any number of known materials. Example of such materials include: inorganics, natural polymers, and synthetic polymers. Specific examples of these materials include: cellulose, cellulose derivatives, acrylic resins, glass; silica gels, polystyrene, gelatin, polyvinyl pyrrolidone, co-polymers of vinyl and acrylamide, polystyrene cross-linked with divinylbenzene or the like (see, Merrifield Biochemistry 1964, 3, 1385-1390), polyacrylamides, latex gels, polystyrene, dextran, rubber, silicon, plastics, nitrocellulose, celluloses, natural sponges, silica gels, glass, metals plastic, cellulose, cross-linked dextrans (e.g., Sephadex™) and agarose gel (Sepharose™) and solid phase supports known to those of skill in the art. In one embodiment, the diameter of the DNA capture bead is in the range of 20-70 μm. In a preferred embodiment, the diameter of the DNA capture bead is in a range of 20-50 μm. In a more preferred embodiment, the diameter of the DNA capture bead is about 30 μm. In one aspect, the invention includes a method for generating a library of solid supports comprising: (a) preparing a population of ssDNA templates according to the methods disclosed herein; (b) attaching each DNA template to a solid support such that there is one molecule of DNA per solid support; (c) amplifying the population of single-stranded templates such that the amplification generates a clonal population of each DNA fragment on each solid support; (d) sequencing clonal populations of beads. In one embodiment, the solid support is a DNA capture bead. In another embodiment, the DNA is genomic DNA, cDNA or reverse transcripts of viral RNA. The DNA may be attached to the solid support, for example, via a biotin-streptavidin linkage, a covalent linkage or by complementary oligonucleotide hybridization. In one embodiment, each DNA template is ligated to a set of universal adaptors. In another embodiment, the universal adaptor pair comprises a common PCR primer sequence, a common sequencing primer sequence and a discriminating key sequence. Single-stranded DNAs are isolated that afford unique ends; single stranded molecules are then attached to a solid support and exposed to amplification techniques for clonal expansion of populations. The DNA may be amplified by PCR. In another aspect, the invention provides a library of solid supports made by the methods described herein. The nucleic acid template (e.g., DNA template) prepared by this method may be used for many molecular biological procedures, such as linear extension, rolling circle amplification, PCR and sequencing. This method can be accomplished in a linkage reaction, for example, by using a high molar ratio of bead to DNA. Capture of single-stranded DNA molecules will follow a poisson distribution and will result in a subset of beads with no DNA attached and a subset of beads with two molecules of DNA attached. In a preferred embodiment, there would be one bead to one molecule of DNA. In addition, it is possible to include additional components in the adaptors that may be useful for additional manipulations of the isolated library. 2. Nucleic Acid Template Amplification In order for the nucleic acid template to be sequenced according to the methods of this invention the copy number must be amplified to generate a sufficient number of copies of the template to produce a detectable signal by the light detection means. Any suitable nucleic acid amplification means may be used. A number of in vitro nucleic acid amplification techniques have been described. These amplification methodologies may be differentiated into those methods: (i) which require temperature cycling—polymerase chain reaction (PCR) (see e.g., Saiki, et al., 1995. Science 230: 1350-1354), ligase chain reaction (see e.g., Barany, 1991. Proc. Natl. Acad. Sci. USA 88: 189-193; Barringer, et al., 1990. Gene 89: 117-122) and transcription-based amplification (see e.g., Kwoh, et al., 1989. Proc. Natl. Acad. Sci. USA 86: 1173-1177) and (ii) isothermal amplification systems—self-sustaining, sequence replication (see e.g., Guatelli, et al., 1990. Proc. Natl. Acad. Sci. USA 87: 1874-1878); the Qβ replicase system (see e.g., Lizardi, et al., 1988. BioTechnology 6: 1197-1202); strand displacement amplification Nucleic Acids Res. Apr. 11, 1992;20(7): 1691-6.; and the methods described in PNAS Jan. 1, 1992;89(1):392-6; and NASBA J Virol Methods. 1991 December;35(3):273-86. In one embodiment, isothermal amplification is used. Isothermal amplification also includes rolling circle-based amplification (RCA). RCA is discussed in, e.g., Kool, U.S. Pat. No. 5,714,320 and Lizardi, U.S. Pat. No. 5,854,033; Hatch, et al., 1999. Genet. Anal. Biomol. Engineer. 15: 35-40. The result of the RCA is a single DNA strand extended from the 3′ terminus of the anchor primer (and thus is linked to the solid support matrix) and including a concatamer containing multiple copies of the circular template annealed to a primer sequence. Typically, 1,000 to 10,000 or more copies of circular templates, each having a size of, e.g., approximately 30-500, 50-200, or 60-100 nucleotides size range, can be obtained with RCA. The product of RCA amplification following annealing of a circular nucleic acid molecule to an anchor primer is shown schematically in FIG. 11A. A circular template nucleic acid 102 is annealed to an anchor primer 104, which has been linked to a surface 106 at its 5′ end and has a free 3′ OH available for extension. The circular template nucleic acid 102 includes two adapter regions 108 and 110 which are complementary to regions of sequence in the anchor primer 104. Also included in the circular template nucleic acid 102 is an insert 112 and a region 114 homologous to a sequencing primer, which is used in the sequencing reactions described below. Upon annealing, the free 3′-OH on the anchor primer 104 can be extended using sequences within the template nucleic acid 102. The anchor primer 102 can be extended along the template multiple times, with each iteration adding to the sequence extended from the anchor primer a sequence complementary to the circular template nucleic acid. Four iterations, or four rounds of rolling circle replication, are shown in FIG. 11A as the extended anchor primer amplification product 114. Extension of the anchor primer results in an amplification product covalently or otherwise physically attached to the substrate 106. A number of in vitro nucleic acid amplification techniques may be utilized to extend the anchor primer sequence. The amplification is typically performed in the presence of a polymerase, e.g., a DNA or RNA-directed DNA polymerase, and one, two, three, or four types of nucleotide triphosphates, and, optionally, auxiliary binding proteins. In general, any polymerase capable of extending a primed 3′-OH group can be used a long as it lacks a 3′ to 5′ exonuclease activity. Suitable polymerases include, e.g., the DNA polymerases from Bacillus stearothermophilus, Thermus acquaticus, Pyrococcus furiosis, Thermococcus litoralis, and Thermus thermophilus, bacteriophage T4 and T7, and the E. coli DNA polymerase I Klenow fragment. Suitable RNA-directed DNA polymerases include, e.g., the reverse transcriptase from the Avian Myeloblastosis Virus, the reverse transcriptase from the Moloney Murine Leukemia Virus, and the reverse transcriptase from the Human Immunodeficiency Virus-I. Additional embodiments of circular templates and anchor primers are shown in more detail in FIG. 11B-11D. FIG. 11B illustrates an annealed open circle linear substrate that can serve, upon ligation, as a template for extension of an anchor primer. A template molecule having the sequence 5′-tcg tgt gag gtc tca gca tct tat gta tat tta ctt cta ttc tca gtt gcc taa gct gca gcc a-3′ (SEQ ID NO:5) is annealed to an anchor primer having a biotin linker at its 5′ terminus and the sequence 5′-gac ctc aca cga tgg ctg cag ctt-3′ (SEQ ID NO:6). Annealing of the template results in juxtaposition of the 5′ and 3′ ends of the template molecule. The 3′OH of the anchor primer can be extended using the circular template. The use of a circular template and an anchor primer for identification of single nucleotide polymorphisms is shown in FIG. 11C. Shown is a generic anchor primer having the sequence 5′-gac ctc aca cga tgg ctg cag ctt-3′(SEQ ID NO:7). The anchor primer anneals to an SNP probe having the sequence 5′-ttt ata tgt att cta cga ctc tgg agt gtg cta ccg acg tcg aat ccg ttg act ctt atc ttc a-3′ (SEQ ID NO:8). The SNP probe in turn hybridizes to a region of a SNP-containing region of a gene having the sequence 5′-cta gct cgt aca tat aaa tga aga taa gat cct g-3′ (SEQ ID NO:9). Hybridization of a nucleic acid sequence containing the polymorphism to the SNP probe complex allows for subsequent ligation and circularization of the SNP probe. The SNP probe is designed so that its 5′ and 3′ termini anneal to the genomic region so as to abut in the region of the polymorphic site, as is indicated in FIG. 11C. The circularized SNP probe can be subsequently extended and sequenced using the methods described herein. A nucleic acid lacking the polymorphism does not hybridize so as to result in juxtaposition of the 5′ and 3′ termini of the SNP probe. In this case, the SNP probe cannot be ligated to form a circular substrate needed for subsequent extension. FIG. 11D illustrates the use of a gap oligonucleotide to along with a circular template molecule. An anchor primer having the sequence 5′-gac ctc aca cga gta gca tgg ctg cag ctt-3′ (SEQ ID NO: 10) is attached to a surface through a biotin linker. A template molecule having the sequence 5′-tcg tgt gag gtc tca gca tct tat gta tat tta ctt cta ttc tca gtt gcc taa gct gca gcc a-3′ (SEQ ID NO:11) is annealed to the anchor primer to result in partially single stranded, or gapped region, in the anchor primer flanked by a double-stranded region. A gapping molecule having the sequence 5′-tgc tac-3′ then anneals to the anchor primer. Ligation of both ends of the gap oligonucleotide to the template molecule results in formation of a circular nucleic acid molecule that can act as a template for rolling circle amplification. RCA can occur when the replication of the duplex molecule begins at the origin. Subsequently, a nick opens one of the strands, and the free 3′-terminal hydroxyl moiety generated by the nick is extended by the action of DNA polymerase. The newly synthesized strand eventually displaces the original parental DNA strand. This aforementioned type of replication is known as rolling-circle replication (RCR) because the point of replication may be envisaged as “rolling around” the circular template strand and, theoretically, it could continue to do so indefinitely. Additionally, because the newly synthesized DNA strand is covalently-bound to the original template, the displaced strand possesses the original genomic sequence (e.g., gene or other sequence of interest) at its 5′-terminus. In RCR, the original genomic sequence is followed by any number of “replication units” complementary to the original template sequence, wherein each replication unit is synthesized by continuing revolutions of said original template sequence. Hence, each subsequent revolution displaces the DNA which is synthesized in the previous replication cycle. Through the use of the RCA reaction, a strand may be generated which represents many tandem copies of the complement to the circularized molecule. For example, RCA has recently been utilized to obtain an isothermal cascade amplification reaction of circularized padlock probes in vitro in order to detect single-copy genes in human genomic DNA samples (see Lizardi, et al., 1998. Nat. Genet. 19: 225-232). In addition, RCA has also been utilized to detect single DNA molecules in a solid phase-based assay, although difficulties arose when this technique was applied to in situ hybridization (see Lizardi, et al., 1998. Nat. Genet. 19: 225-232). If desired, RCA can be performed at elevated temperatures, e.g., at temperatures greater than 37° C., 42° C., 45° C., 50° C., 60° C., or 70° C. In addition, RCA can be performed initially at a lower temperature, e.g., room temperature, and then shifted to an elevated temperature. Elevated temperature RCA is preferably performed with thermostable nucleic acid polymerases and with primers that can anneal stably and with specificity at elevated temperatures. RCA can also be performed with non-naturally occurring oligonucleotides, e.g., peptide nucleic acids. Further, RCA can be performed in the presence of auxiliary proteins such as single-stranded binding proteins. The development of a method of amplifying short DNA molecules which have been immobilized to a solid support, termed RCA has been recently described in the literature (see e.g., Hatch, et al., 1999. Genet. Anal. Biomol. Engineer. 15: 35-40; Zhang, et al., 1998. Gene 211: 277-85; Baner, et al., 1998. Nucl. Acids Res. 26: 5073-5078; Liu, et al., 1995. J. Am. Chem. Soc. 118: 1587-1594; Fire and Xu, 1995. Proc. Natl. Acad. Sci. USA 92: 4641-4645; Nilsson, et al., 1994. Science 265: 2085-2088). RCA targets specific DNA sequences through hybridization and a DNA ligase reaction. The circular product is then subsequently used as a template in a rolling circle replication reaction. Other examples of isothermal amplification systems include, e.g., (i) self-sustaining, sequence replication (see e.g., Guatelli, et al., 1990. Proc. Natl. Acad. Sci. USA 87: 1874-1878), (ii) the Qβ replicase system (see e.g., Lizardi, et al., 1988. BioTechnology 6: 1197-1202), and (iii) nucleic acid sequence-based amplification (NASBA™; see Kievits, et al., 1991. J. Virol. Methods 35: 273-286). PCR Amplification of Nucleic Acid Templates In a preferred embodiment, polymerase chain reaction (“PCR”) is used to generate additional copies of the template nucleic acids. The PCR amplification step may be performed prior to distribution of the nucleic acid templates onto the picotiter plate or may be performed after the nucleic acid templates have been distributed onto the picotiter plate. Bead Emulsion PCR Amplification In a preferred embodiment, a PCR amplification step is performed prior to distribution of the nucleic acid templates onto the picotiter plate. In a particularly preferred embodiment, a novel amplification system, herein termed “bead emulsion amplification” is performed by attaching a template nucleic acid (e.g., DNA) to be amplified to a solid support, preferably in the form of a generally spherical bead. A library of single stranded template DNA prepared according to the sample prepration methods of this invention is an example of one suitable source of the starting nucleic acid template library to be attached to a bead for use in this amplification method. The bead is linked to a large number of a single primer species (i.e., primer B in FIG. 6) that is complementary to a region of the template DNA. Template DNA annealed to the bead bound primer. The beads are suspended in aqueous reaction mixture and then encapsulated in a water-in-oil emulsion. The emulsion is composed of discrete aqueous phase microdroplets, approximately 60 to 200 um in diameter, enclosed by a thermostable oil phase. Each microdroplet contains, preferably, amplification reaction solution (i.e., the reagents necessary for nucleic acid amplification). An example of an amplification would be a PCR reaction mix (polymerase, salts, dNTPs) and a pair of PCR primers (primer A and primer B). See, FIG. 6A. A subset of the microdroplet population also contains the DNA bead comprising the DNA template. This subset of microdroplet is the basis for the amplification. The microcapsules that are not within this subset have no template DNA and will not participate in amplification. In one embodiment, the amplification technique is PCR and the PCR primers are present in a 8:1 or 16:1 ratio (i.e., 8 or 16 of one primer to 1 of the second primer) to perform asymmetric PCR. In this overview, the DNA is annealed to an oligonucleotide (primer B) which is immobilized to a bead. During thermocycling (FIG. 6B), the bond between the single stranded DNA template and the immobilized B primer on the bead is broken, releasing the template into the surrounding microencapsulated solution. The amplification solution, in this case, the PCR solution, contains addition solution phase primer A and primer B. Solution phase B primers readily bind to the complementary b′ region of the template as binding kinetics are more rapid for solution phase primers than for immobilized primers. In early phase PCR, both A and B strands amplify equally well (FIG. 6C). By midphase PCR (i.e., between cycles 10 and 30) the B primers are depleted, halting exponential amplification. The reaction then enters asymmetric amplification and the amplicon population becomes dominated by A strands (FIG. 6D). In late phase PCR (FIG. 6E), after 30 to 40 cycles, asymmetric amplification increases the concentration of A strands in solution. Excess A strands begin to anneal to bead immobilized B primers. Thermostable polymerases then utilize the A strand as a template to synthesize an immobilized, bead bound B strand of the amplicon. In final phase PCR (FIG. 6F), continued thermal cycling forces additional annealing to bead bound primers. Solution phase amplification may be minimal at this stage but concentration of immobilized B strands increase. Then, the emulsion is broken and the immobilized product is rendered single stranded by denaturing (by heat, pH etc.) which removes the complimentary A strand. The A primers are annealed to the A′ region of immobilized strand, and immobilized strand is loaded with sequencing enzymes, and any necessary accessory proteins. The beads are then sequenced using recognized pyrophosphate techniques (described, e.g., in U.S. Pat. Nos. 6,274,320, 6258,568 and 6,210,891, incorporated in toto herein by reference). Template Design In a preferred embodiment, the DNA template to be amplified by bead emulsion amplification can be a population of DNA such as, for example, a genomic DNA library or a cDNA library. It is preferred that each member of the population have a common nucleic acid sequence at the first end and a common nucleic acid sequence at a second end. This can be accomplished, for example, by ligating a first adaptor DNA sequence to one end and a second adaptor DNA sequence to a second end of the DNA population. Many DNA and cDNA libraries, by nature of the cloning vector (e.g., Bluescript, Stratagene, La Jolla, Calif.) fit this description of having a common sequence at a first end and a second common sequence at a second end of each member DNA. The DNA template may be of any size amenable to in vitro amplification (including the preferred amplification techniques of PCR and asymmetric PCR). In a preferred embodiment, the DNA template is between about 150 to 750 bp in size, such as, for example about 250 bp in size. Binding Nucleic Acid Template to Capture Beads In a first step, a single stranded nucleic acid template to be amplified is attached to a capture bead. The nucleic acid template may be attached to the solid support capture bead in any manner known in the art. Numerous methods exist in the art for attaching DNA to a solid support such as the preferred microscopic bead. According to the present invention, covalent chemical attachment of the DNA to the bead can be accomplished by using standard coupling agents, such as water-soluble carbodiimide, to link the 5′-phosphate on the DNA to amine-coated capture beads through a phosphoamidate bond. Another alternative is to first couple specific oligonucleotide linkers to the bead using similar chemistry, and to then use DNA ligase to link the DNA to the linker on the bead. Other linkage chemistries to join the oligonucleotide to the beads include the use of N-hydroxysuccinamide (NHS) and its derivatives. In such a method, one end of the oligonucleotide may contain a reactive group (such as an amide group) which forms a covalent bond with the solid support, while the other end of the linker contains a second reactive group that can bond with the oligonucleotide to be immobilized. In a preferred embodiment, the oligonucleotide is bound to the DNA capture bead by covalent linkage. However, non-covalent linkages, such as chelation or antigen-antibody complexes, may also be used to join the oligonucleotide to the bead. Oligonucleotide linkers can be employed which specifically hybridize to unique sequences at the end of the DNA fragment, such as the overlapping end from a restriction enzyme site or the “sticky ends” of bacteriophage lambda based cloning vectors, but blunt-end ligations can also be used beneficially. These methods are described in detail in U.S. Pat. No. 5,674,743. It is preferred that any method used to immobilize the beads will continue to bind the immobilized oligonucleotide throughout the steps in the methods of the invention. In one embodiment, each capture bead is designed to have a plurality of nucleic acid primers that recognize (i.e., are complementary to) a portion of the nucleic template, and the nucleic acid template is thus hybridized to the capture bead. In the methods described herein, clonal amplification of the template species is desired, so it is preferred that only one unique nucleic acid template is attached to any one capture bead. The beads used herein may be of any convenient size and fabricated from any number of known materials. Example of such materials include: inorganics, natural polymers, and synthetic polymers. Specific examples of these materials include: cellulose, cellulose derivatives, acrylic resins, glass, silica gels, polystyrene, gelatin, polyvinyl pyrrolidone, co-polymers of vinyl and acrylamide, polystyrene cross-linked with divinylbenzene or the like (as described, e.g., in Merrifield, Biochemistry 1964, 3, 1385-1390), polyacrylamides, latex gels, polystyrene, dextran, rubber, silicon, plastics, nitrocellulose, natural sponges, silica gels, control pore glass, metals, cross-linked dextrans (e.g., Sephadex™) agarose gel (Sepharose™), and solid phase supports known to those of skill in the art. In a preferred embodiment, the capture beads are Sepharose beads approximately 25 to 40 μm in diameter. Emulsification Capture beads with attached single strand template nucleic acid are emulsified as a heat stable water-in-oil emulsion. The emulsion may be formed according to any suitable method known in the art. One method of creating emulsion is described below but any method for making an emulsion may be used. These methods are known in the art and include adjuvant methods, counterflow methods, crosscurrent methods, rotating drum methods, and membrane methods. Furthermore, the size of the microcapsules may be adjusted by varying the flow rate and speed of the components. For example, in dropwise addition, the size of the drops and the total time of delivery may be varied. Preferably, the emulsion contains a density of bead “microreactors” at a density of about 3,000 beads per microliter. The emulsion is preferably generated by suspending the template-attached beads in amplification solution. As used herein, the term “amplification solution” means the sufficient mixture of reagents that is necessary to perform amplification of template DNA. One example of an amplification solution, a PCR amplification solution, is provided in the Examples below—it will be appreciated that various modifications may be made to the PCR solution. In one embodiment, the bead/amplification solution mixture is added dropwise into a spinning mixture of biocompatible oil (e.g., light mineral oil, Sigma) and allowed to emulsify. The oil used may be supplemented with one or more biocompatible emulsion stabilizers. These emulsion stabilizers may include Atlox 4912, Span 80, and other recognized and commercially available suitable stabilizers. Preferably, the droplets formed range in size from 5 micron to 500 microns, more preferably, from between about 50 to 300 microns, and most preferably, from 100 to 150 microns. There is no limitation in the size of the microreactors. The microreactors should be sufficiently large to encompass sufficient amplification reagents for the degree of amplification required. However, the microreactors should be sufficiently small so that a population of microreactors, each containing a member of a DNA library, can be amplified by conventional laboratory equipment (e.g., PCR thermocycling equipment, test tubes, incubators and the like). With the limitations described above, the optimal size of a microreactor may be between 100 to 200 microns in diameter. Microreactors of this size would allow amplification of a DNA library comprising about 600,000 members in a suspension of microreactors of less than 10 ml in volume. For example, if PCR was the chosen amplification method, 10 mls would fit in 96 tubes of a regular thermocycler with 96 tube capacity. In a preferred embodiment, the suspension of 600,000 microreactors would have a volume of less than 1 ml. A suspension of less than 1 ml may be amplified in about 10 tubes of a conventional PCR thermocycler. In a most preferred embodiment, the suspension of 600,000 microreactors would have a volume of less than 0.5 ml. Amplification After encapsulation, the template nucleic acid may be amplified by any suitable method of DNA amplification including transcription-based amplification systems (Kwoh D. et al., Proc. Natl. Acad. Sci. (U.S.A.) 86:1173 (1989); Gingeras T. R. et al., PCT appl. WO 88/10315; Davey, C. et al., European Patent Application Publication No. 329,822; Miller, H. I. et al., PCT appl. WO 89/06700, and “race” (Frohman, M. A., In: PCR Protocols: A Guide to Methods and Applications, Academic Press, NY (1990)) and “one-sided PCR” (Ohara, O. et al., Proc. Natl. Acad. Sci. (U.S.A.) 86.5673-5677 (1989)). Still other less common methods such as “di-oligonucleotide” amplification, isothermal amplification (Walker, G. T. et al., Proc. Natl. Acad. Sci. (U.S.A.) 89:392-396 (1992)), and rolling circle amplification (reviewed in U.S. Pat. No. 5,714,320), may be used in the present invention. In a preferred embodiment, DNA amplification is performed by PCR. PCR according to the present invention may be performed by encapsulating the target nucleic acid, bound to a bead, with a PCR solution comprising all the necessary reagents for PCR. Then, PCR may be accomplished by exposing the emulsion to any suitable thermocycling regimen known in the art. In a preferred embodiment, between 30 and 50 cycles, preferably about 40 cycles, of amplification are performed. It is desirable, but not necessary, that following the amplification procedure there be one or more hybridization and extension cycles following the cycles of amplification. In a preferred embodiment, between 10 and 30 cycles, preferably about 25 cycles, of hybridization and extension are performed (e.g., as described in the examples). Routinely, the template DNA is amplified until typically at least two million to fifty million copies, preferably about ten million to thirty million copies of the template DNA are immobilized per bead. Breaking the Emulsion and Bead Recovery Following amplification of the template, the emulsion is “broken” (also referred to as “demulsification” in the art). There are many methods of breaking an emulsion (see, e.g., U.S. Pat. No. 5,989,892 and references cited therein) and one of skill in the art would be able to select the proper method. In the present invention, one preferred method of breaking the emulsion is to add additional oil to cause the emulsion to separate into two phases. The oil phase is then removed, and a suitable organic solvent (e.g., hexanes) is added. After mixing, the oil/organic solvent phase is removed. This step may be repeated several times. Finally, the aqueous layers above the beads are removed. The beads are then washed with an organic solvent/annealing buffer mixture (e.g., one suitable annealing buffer is described in the examples), and then washed again in annealing buffer. Suitable organic solvents include alcohols such as methanol, ethanol and the like. The amplified template-containing beads may then be resuspended in aqueous solution for use, for example, in a sequencing reaction according to known technologies. (See, Sanger, F. et al., Proc. Natl. Acad. Sci. U.S.A. 75, 5463-5467 (1977); Maxam, A. M. & Gilbert, W. Proc Natl Acad Sci USA 74, 560-564 (1977); Ronaghi, M. et al., Science 281, 363, 365 (1998); Lysov, I. et al., Dokl Akad Nauk SSSR 303, 1508-1511 (1988); Bains W. & Smith G. C. J. Theor Biol 135, 303-307(1988); Dmanac, R. et al., Genomics 4, 114-128 (1989); Khrapko, K. R. et al., FEBS Lett 256. 118-122 (1989); Pevzner P. A. J Biomol Struct Dyn 7, 63-73 (1989); Southern, E. M. et al., Genomics 13, 1008-1017 (1992).) If the beads are to be used in a pyrophosphate-based sequencing reaction (described, e.g., in U.S. Pat. Nos. 6,274,320, 6258,568 and 6,210,891, and incorporated in toto herein by reference), then it is necessary to remove the second strand of the PCR product and anneal a sequencing primer to the single stranded template that is bound to the bead. Briefly, the second strand is melted away using any number of commonly known methods such as NaOH, low ionic (e.g., salt) strength, or heat processing. Following this melting step, the beads are pelleted and the supernatant is discarded. The beads are resuspended in an annealing buffer, the sequencing primer added, and annealed to the bead-attached single stranded template using a standard annealing cycle. Purifying the Beads At this point, the amplified DNA on the bead may be sequenced either directly on the bead or in a different reaction vessel. In an embodiment of the present invention, the DNA is sequenced directly on the bead by transferring the bead to a reaction vessel and subjecting the DNA to a sequencing reaction (e.g., pyrophosphate or Sanger sequencing). Alternatively, the beads may be isolated and the DNA may be removed from each bead and sequenced. In either case, the sequencing steps may be performed on each individual bead. However, this method, while commercially viable and technically feasible, may not be most effective because many of the beads will be negative beads (a bead that does not have amplified DNA attached). Accordingly, the following optional process may be used for removing beads that contain no nucleic acid template prior to distribution onto the picotiter plate. A high percentage of the beads may be “negative” (i.e., have no amplified nucleic acid template attached thereto) if the goal of the initial DNA attachment is to minimize beads with two different copies of DNA. For useful pyrophosphate sequencing, each bead should contain multiple copies of a single species of DNA. This requirement is most closely approached by maximizing the total number of beads with a single fragment of DNA bound (before amplification). This goal can be achieved by the observation of a mathematical model. For the general case of “N” number of DNAs randomly distributed among M number of beads, the relative bead population containing any number of DNAs depends on the ratio of N/M. The fraction of beads containing N DNAs R(N) may be calculated using the Poisson distribution: R(N)=exp−(N/M)×(N/M)N/N! (where X is the multiplication symbol) The table below shows some calculated values for various N/M (the average DNA fragment to bead ratio) and N (the number of fragments actually bound to a bead). N/M 0.1 0.5 1 2 R(0) 0.9 0.61 0.37 0.13 R(1) 0.09 0.3 0.37 0.27 R(N > 1) 0.005 0.09 0.26 0.59 In the table the top row denotes the various ratios of N/M. R(0) denotes the fraction of beads with no DNA, R(1) denotes the fraction of beads with one DNA attached (before amplification) and R(N>1) denotes the fraction of DNA with more than one DNA attached (before amplification). The table indicates that the maximum fraction of beads containing a single DNA fragment is 0.37 (37%) and occurs at a fragment to bead ratio of one. In this mixture, about 63% of the beads is useless for sequencing because they have either no DNA or more than a single species of DNA. Additionally, controlling the fragment to bead ratio require complex calculations and variability could produce bead batches with a significantly smaller fraction of useable beads. This inefficiency could be significantly ameliorated if beads containing amplicon (originating from the binding of at least one fragment) could be separated from those without amplicon (originating from beads with no bound fragments). An amplicon is defined as any nucleic acid molecules produced by an in vitro nucleic amplification technique. Binding would be done at low average fragment-to-bead ratios (N/M<1), minimizing the ratio of beads with more than one DNA bound. A separation step would remove most or all of the beads with no DNA leaving an enriched population of beads with one species of amplified DNA. These beads may be applied to any method of sequencing such as, for example, pyrophosphate sequencing. Because the fraction of beads with one amplicon (N=1) has been enriched, any method of sequencing would be more efficient. As an example, with an average fragment to bead ratio of 0.1, 90% of the beads will have no amplicon, 9% of the beads would be useful with one amplicon, and 0.5% of the beads will have more than one amplicon. An enrichment process of the invention will remove the 90% of the zero amplicon beads leaving a population of beads where the sequenceable fraction (N=1) is: 1−(0.005/0.09)=94%. Dilution of the fragment to bead mixture, along with separation of beads containing amplicon can yield an enrichment of 2.5 folds over the optimal unenriched method. 94%/37% (see table above N/M=1)=2.5. An additional benefit of the enrichment procedure of the invention is that the ultimate fraction of sequenceable beads is relatively insensitive to variability in N/M. Thus, complex calculations to derive the optimal N/M ratio are either unnecessary or may be performed to a lower level of precision. This will ultimately make the procedure more suitable to performance by less trained personnel or automation. An additional benefit of the procedure is that the zero amplicon beads may be recycled and reused. While recycling is not necessary, it may reduce cost or the total bulk of reagents making the method of the invention more suitable for some purposes such as, for example, portable sampling, remote robotic sampling and the like. In addition, all the benefits of the procedure (i.e., less trained personnel, automation, recycling of reagents) will reduce the cost of the procedure. The procedure is described in more detail below. The enrichment procedure may be used to treat beads that have been amplified in the bead emulsion method above. The amplification is designed so that each amplified molecule contains the same DNA sequence at its 3′ end. The nucleotide sequence may be a 20 mer but may be any sequence from 15 bases or more such as 25 bases, 30 bases, 35 bases, or 40 bases or longer. Naturally, while longer oligonucleotide ends are functional, they are not necessary. This DNA sequence may be introduced at the end of an amplified DNA by one of skill in the art. For example, if PCR is used for amplification of the DNA, the sequence may be part of one member of the PCR primer pair. A schematic of the enrichment process is illustrated in FIG. 7. Here, the amplicon-bound bead mixed with 4 empty beads represents the fragment-diluted amplification bead mixture. In step 1, a biotinylated primer complementary to the 3′ end of the amplicon is annealed to the amplicon. In step 2, DNA polymerase and the four natural deoxynucleotides triphosphates (dNTPs) are added to the bead mix and the biotinylated primer is extended. This extension is to enhance the bonding between the biotinylated primer and the bead-bound DNA. This step may be omitted if the biotinylated primer—DNA bond is strong (e.g., in a high ionic environment). In Step 3, streptavidin coated beads susceptible to attraction by a magnetic field (referred to herein as “magnetic streptavidin beads”) are introduced to the bead mixtures. Magnetic beads are commercially available, for example, from Dynal (M290). The streptavidin capture moieties binds biotins hybridized to the amplicons, which then specifically fix the amplicon-bound beads to the magnetic streptavidin beads. In step 5, a magnetic field (represented by a magnet) is applied near the reaction mixture, which causes all the “magnetic streptavidin beads/amplicon bound bead complexes” to be positioned along one side of the tube most proximal to the magnetic field. Magnetic beads without amplicon bound beads attached are also expected to be positioned along the same side. Beads without amplicons remain in solution. The bead mixture is washed and the beads not immobilized by the magnet (i.e., the empty beads) are removed and discarded. In step 6, the extended biotinylated primer strand is separated from the amplicon strand by “melting”—a step that can be accomplished, for example, by heat or a change in pH. The heat may be 60° C. in low salt conditions (e.g., in a low ionic environment such as 0.1×SSC). The change in pH may be accomplished by the addition of NaOH. The mixture is then washed and the supernatant, containing the amplicon bound beads, is recovered while the now unbound magnetic beads are retained by a magnetic field. The resultant enriched beads may be used for DNA sequencing. It is noted that the primer on the DNA capture bead may be the same as the primer of step 2 above. In this case, annealing of the amplicon-primer complementary strands (with or without extension) is the source of target-capture affinity. The biotin streptavidin pair could be replaced by a variety of capture-target pairs. Two categories are pairs whose binding can be subsequently cleaved and those which bind irreversibly, under conditions that are practically achievable. Cleavable pairs include thiol-thiol, Digoxigenin/anti-Digoxigenin, -Captavidin™ if cleavage of the target-capture complex is desired. As described above, step 2 is optional. If step 2 is omitted, it may not be necessary to separate the magnetic beads from the amplicon bound beads. The amplicon bound beads, with the magnetic beads attached, may be used directly for sequencing. If the sequencing were to be performed in a microwell, separation would not be necessary if the amplicon bound bead-magnetic bead complex can fit inside the microwell. While the use of magnetic capture beads is convenient, capture moieties can be bound to other surfaces. For example, streptavidin could be chemically bound to a surface, such as, the inner surface of a tube. In this case, the amplified bead mixture may be flowed through. The amplicon bound beads will tend to be retained until “melting” while the empty beads will flow through. This arrangement may be particularly advantageous for automating the bead preparation process. While the embodiments described above is particularly useful, other methods can be envisioned to separate beads. For example, the capture beads may be labeled with a fluorescent moiety which would make the target-capture bead complex fluorescent. The target capture bead complex may be separated by flow cytometry or fluorescence cell sorter. Using large capture beads would allow separation by filtering or other particle size separation techniques. Since both capture and target beads are capable of forming complexes with a number of other beads, it is possible to agglutinate a mass of cross-linked capture-target beads. The large size of the agglutinated mass would make separation possible by simply washing away the unagglutinated empty beads. The methods described are described in more detail, for example, in Bauer, J.; J. Chromatography B, 722 (1999) 55-69 and in Brody et al., Applied Physics Lett. 74 (1999) 144-146. The DNA capture beads each containing multiple copies of a single species of nucleic acid template prepared according to the above method are then suitable for distribution onto the picotiter plate. Nucleic Acid Amplification on the Picotiter Plate In an alternative embodiment, the nucleic acid template is distributed onto the picotiter plate prior to amplification and then amplified in situ on the picotiter plate. This method is described in detail in the Examples. 3. Sequencing the Nucleic Acid Template Pyrophosphate sequencing is used according to the methods of this invention to sequence the nucleic acid template. This technique is based on the detection of released pyrophosphate (Ppi) during DNA synthesis. See, e.g., Hyman, 1988. A new method of sequencing DNA. Anal Biochem. 174:423-36; Ronaghi, 2001. Pyrosequencing sheds light on DNA sequencing. Genome Res. 11:3-11. In a cascade of enzymatic reactions, visible light is generated proportional to the number of incorporated nucleotides. The cascade starts with a nucleic acid polymerization reaction in which inorganic Ppi is released with nucleotide incorporation by polymerase. The released Ppi is converted to ATP by ATP sulfurylase, which provides the energy to luciferase to oxidize luciferin and generates light. Because the added nucleotide is known, the sequence of the template can be determined. Solid-phase pyrophosphate sequencing utilizes immobilized DNA in a three-enzyme system (see Figures). To increase the signal-to-noise ratio, the natural dATP has been replaced by dATPαS. Typically dATPαS is a mixture of two isomers (Sp and Rp); the use of pure 2′-deoxyadenosine-5′-O′-(1-thiotriphosphate) Sp-isomer in pyrophosphate sequencing allows substantially longer reads, up to doubling of the read length. 4. Apparatus for Sequencing Nucleic Acids This invention provides an apparatus for sequencing nucleic acids, which generally comprises one or more reaction chambers for conducting a sequencing reaction, means for delivering reactants to and from the reaction chamber(s), and means for detecting a sequencing reaction event. In another embodiment, the apparatus includes a reagent delivery cuvette containing a plurality of cavities on a planar surface. In a preferred embodiment, the apparatus is connected to at least one computer for controlling the individual components of the apparatus and for storing and/or analyzing the information obtained from detection of the sequence reaction event. The invention also provides one or more reaction chambers are arranged on an inert substrate material, also referred to herein as a “solid support”, that allows for discrete localization of the nucleic acid template and of the reactants in a sequencing reaction in a defined space, as well as for detection of the sequencing reaction event. Thus, as used herein, the terms “reaction chamber” or “analyte reaction chamber” refer to a localized area on the substrate material that facilitates interaction of reactants, e.g., in a nucleic acid sequencing reaction. As discussed more fully below, the sequencing reactions contemplated by the invention preferably occur on numerous individual nucleic acid samples in tandem, in particular simultaneously sequencing numerous nucleic acid samples derived from genomic and chromosomal nucleic acid templates (e.g., DNA). The apparatus of the invention therefore preferably comprises a sufficient number of reaction chambers to carry out such numerous individual sequencing reactions. In one embodiment, there are at least 10,000 reaction chambers, preferably at least 50,000 reaction chambers, more preferably greater than 100,000 reaction chambers, even more preferably greater than 200,000 reaction chambers. Since the number of simultaneous sequencing reactions is limited by the number of reaction chambers, the throughput may be increased by fabricating plates containing increasing densities of wells. The table below shows this progression for a 14×43 mm and 30×60 mm active areas, derived from 25×75 mm and 40×75 mm arrays, respectively. TABLE Development of higher well count arrays. Pitch Well # of Wells # of Wells (um) Diameter (um) (14 × 43 mm) (30 × 60 mm) 50 44 275K 800K 43 38 375K 1.2M 35 31 575K 1.6M 25 22 1.1M 3.2M The reaction chambers on the array typically take the form of a cavity or well in the substrate material, having a width and depth, into which reactants can be deposited. Typically the nucleic acid template is distributed into the reaction chamber on one or more solid supports or beads; the reactants are in a medium which facilitates the reaction and which flows through the reaction chamber. When formed as cavities or wells, the chambers are preferably of sufficient dimension and order to allow for (i) the introduction of the necessary reactants into the chambers, (ii) reactions to take place within the chamber and (iii) inhibition of mixing of reactants between chambers. The shape of the well or cavity is preferably circular or cylindrical, but can be multisided so as to approximate a circular or cylindrical shape. In one preferred embodiment, the shape of the well or cavity is substantially hexagonal. The cavity can have a smooth wall surface. In an additional embodiment, the cavity can have at least one irregular wall surface. The cavities can have a planar bottom or a concave bottom. The reaction chambers can be spaced between 5 μm and 200 μm apart. Spacing is determined by measuring the center-to-center distance between two adjacent reaction chambers. Typically, the reaction chambers can be spaced between 10 μm and 150 μm apart, preferably between 20 μm and 100 μm apart, most preferably between 40 and 60 μm apart. In one embodiment, the reaction chambers have a width (diameter) in one dimension of between 0.3 μm and 100 μm, more preferably between 20 μm and 70 μm and most preferably about 30 and 50 μm. The depth of the reaction chambers are preferably between 10 μm and 100 μm, preferably between 20 μm and 60 μm. Alternatively, the reaction chambers may have a depth that is between 0.25 and 5 times the width in one dimension of the reaction chamber or, in another embodiment, between 0.3 and 1 times the width in one dimension of the reaction chamber. In a preferred embodiment, the array is fashioned from a sliced fiber optic bundle (i.e., a bundle of fused fiber optic cables) and the reaction chambers are formed by etching one surface of the fiber optic reactor array. The cavities can also be formed in the substrate via etching, molding or micromachining. Each cavity or reaction chamber typically has a depth of between 10 μm and 100 μm; alternatively, the depth is between 0.25 and 5 times the size of the width of the cavity, preferably between 0.3 and 1 times the size of the width of the cavity. In one embodiment, the arrays described herein typically include a planar top surface and a planar bottom surface, which is optically conductive such that optical signals from the reaction chambers can be detected through the bottom planar surface. In these arrays, typically the distance between the top surface and the bottom surface is no greater than 10 cm, preferably no greater than 2 cm, and usually between 0.5 mm to 5 mm, most preferably about 2 mm. In a particularly preferred embodiment, the solid support is termed a picotiterplate, with reaction chambers having a center to center spacing of about 43 μm to 50 μm, a well diameter of between 38 μm to 44 μm, and a well volume of between 10 to 150 pL, preferably between 20 to 90 pL, more preferably between 40 to 85 pL, and most preferably about 75 pL. In one embodiment, each cavity or reaction chamber of the array contains reagents for analyzing a nucleic acid or protein. Typically those reaction chambers that contain a nucleic acid (not all reaction chambers in the array are required to) contain only a single species of nucleic acid (i.e., a single sequence that is of interest). There may be a single copy of this species of nucleic acid in any particular reaction chamber, or there may be multiple copies. It is generally preferred that a reaction chamber contain at least 100,000 copies of the nucleic acid template sequence, preferably at least 1,000,000 copies, and more preferably between 2,000,000 to 20,000,000 copies, and most preferably between 5,000,000 to 15,000,000 copies of the nucleic acid. The ordinarily skilled artisan will appreciate that changes in the number of copies of a nucleic acid species in any one reaction chamber will affect the number of photons generated in a pyrosequencing reaction, and can be routinely adjusted to provide more or less photon signal as is required. In one embodiment the nucleic acid species is amplified to provide the desired number of copies using PCR, RCA, ligase chain reaction, other isothermal amplification, or other conventional means of nucleic acid amplification. In one embodiment, the nucleic acid is single stranded. Solid Support Material Any material can be used as the solid support material, as long as the surface allows for stable attachment of the primers and detection of nucleic acid sequences. The solid support material can be planar or can be cavitated, e.g., in a cavitated terminus of a fiber optic or in a microwell etched, molded, or otherwise micromachined into the planar surface, e.g. using techniques commonly used in the construction of microelectromechanical systems. See e.g., Rai-Choudhury, HANDBOOK OF MICROLITHOGRAPHY, MICROMACHINING, AND MICROFABRICATION, VOLUME I: MICROLITHOGRAPHY, Volume PM39, SPEE Press (1997); Madou, CRC Press (1997), Aoki, Biotech. Histochem. 67: 98-9 (1992); Kane et al., Biomaterials. 20: 2363-76 (1999); Deng et al., Anal. Chem. 72:3176-80 (2000); Zhu et al., Nat. Genet. 26:283-9 (2000). In some embodiments, the solid support is optically transparent, e.g., glass. An array of attachment sites on an optically transparent solid support can be constructed using lithographic techniques commonly used in the construction of electronic integrated circuits as described in, e.g., techniques for attachment described in U.S. Pat. Nos. 5,143,854, 5,445,934, 5,744,305, and 5,800,992; Chee et al., Science 274: 610-614 (1996); Fodor et al., Nature 364: 555-556 (1993); Fodor et al., Science 251: 767-773 (1991); Gushin, et al., Anal. Biochem. 250: 203-211 (1997); Kinosita et al., Cell 93: 21-24 (1998); Kato-Yamada et al., J. Biol. Chem. 273: 19375-19377 (1998); and Yasuda et al., Cell 93: 1117-1124 (1998). Photolithography and electron beam lithography sensitize the solid support or substrate with a linking group that allows attachment of a modified biomolecule (e.g., proteins or nucleic acids). See e.g., Service, Science 283: 27-28 (1999); Rai-Choudhury, HANDBOOK OF MICROLITHOGRAPHY, MICROMACHINING, AND MICROFABRICATION, VOLUME I: MICROLITHOGRAPHY, Volume PM39, SPIE Press (1997). Alternatively, an array of sensitized sites can be generated using thin-film technology as described in Zasadzinski et al., Science 263: 1726-1733 (1994). The substrate material is preferably made of a material that facilitates detection of the reaction event. For example, in a typical sequencing reaction, binding of a dNTP to a sample nucleic acid to be sequenced can be monitored by detection of photons generated by enzyme action on phosphate liberated in the sequencing reaction. Thus, having the substrate material made of a transparent or light conductive material facilitates detection of the photons. In some embodiments, the solid support can be coupled to a bundle of optical fibers that are used to detect and transmit the light product. The total number of optical fibers within the bundle may be varied so as to match the number of individual reaction chambers in the array utilized in the sequencing reaction. The number of optical fibers incorporated into the bundle is designed to match the resolution of a detection device so as to allow 1:1 imaging. The overall sizes of the bundles are chosen so as to optimize the usable area of the detection device while maintaining desirable reagent (flow) characteristics in the reaction chamber. Thus, for a 4096×4096 pixel CCD (charge-coupled device) array with 15 μm pixels, the fiber bundle is chosen to be approximately 60 mm×60 mm or to have a diameter of approximately 90 mm. The desired number of optical fibers are initially fused into a bundle or optical fiber array, the terminus of which can then be cut and polished so as to form a “wafer” of the required thickness (e.g., 1.5 mm). The resulting optical fiber wafers possess similar handling properties to that of a plane of glass. The individual fibers can be any size diameter (e.g., 3 μm to 100 μm). In some embodiments two fiber optic bundles are used: a first bundle is attached directly to the detection device (also referred to herein as the fiber bundle or connector) and a second bundle is used as the reaction chamber substrate (the wafer or substrate). In this case the two are placed in direct contact, optionally with the use of optical coupling fluid, in order to image the reaction centers onto the detection device. If a CCD is used as the detection device, the wafer could be slightly larger in order to maximize the use of the CCD area, or slightly smaller in order to match the format of a typical microscope slide—25 mm×75 mm. The diameters of the individual fibers within the bundles are chosen so as to maximize the probability that a single reaction will be imaged onto a single pixel in the detection device, within the constraints of the state of the art. Exemplary diameters are 6-8 μm for the fiber bundle and 6-50 μm for the wafer, though any diameter in the range 3-100 μm can be used. Fiber bundles can be obtained commercially from CCD camera manufacturers. For example, the wafer can be obtained from Incom, Inc. (Charlton, Mass.) and cut and polished from a large fusion of fiber optics, typically being 2 mm thick, though possibly being 0.5 to 5 mm thick. The wafer has handling properties similar to a pane of glass or a glass microscope slide. Reaction chambers can be formed in the substrate made from fiber optic material. The surface of the optical fiber is cavitated by treating the termini of a bundle of fibers, e.g., with acid, to form an indentation in the fiber optic material. Thus, in one embodiment cavities are formed from a fiber optic bundle, preferably cavities can be formed by etching one end of the fiber optic bundle. Each cavitated surface can form a reaction chamber. Such arrays are referred to herein as fiber optic reactor arrays or FORA. The indentation ranges in depth from approximately one-half the diameter of an individual optical fiber up to two to three times the diameter of the fiber. Cavities can be introduced into the termini of the fibers by placing one side of the optical fiber wafer into an acid bath for a variable amount of time. The amount of time can vary depending upon the overall depth of the reaction cavity desired (see e.g., Walt, et al., 1996. Anal. Chem. 70: 1888). A wide channel cavity can have uniform flow velocity dimensions of approximately 14 mm×43 mm. Thus, with this approximate dimension and at approximately 4.82×10−4 cavities/um2 density, the apparatus can have approximately 290,000 fluidically accessible cavities. Several methods are known in the art for attaching molecules (and detecting the attached molecules) in the cavities etched in the ends of fiber optic bundles. See, e.g., Michael, et al., Anal. Chem. 70: 1242-1248 (1998); Ferguson, et al., Nature Biotechnology 14: 1681-1684 (1996); Healey and Walt, Anal. Chem. 69: 2213-2216 (1997). A pattern of reactive sites can also be created in the microwell, using photolithographic techniques similar to those used in the generation of a pattern of reaction pads on a planar support. See, Healey, et al., Science 269: 1078-1080 (1995); Munkholm and Walt, Anal. Chem. 58: 1427-1430 (1986), and Bronk, et al., Anal. Chem. 67: 2750-2757 (1995). The opposing side of the optical fiber wafer (i.e., the non-etched side) is typically highly polished so as to allow optical-coupling (e.g., by immersion oil or other optical coupling fluids) to a second, optical fiber bundle. This second optical fiber bundle exactly matches the diameter of the optical wafer containing the reaction chambers, and serve to act as a conduit for the transmission of light product to the attached detection device, such as a CCD imaging system or camera. In one preferred embodiment, the fiber optic wafer is thoroughly cleaned, e.g. by serial washes in 15% H2O2/15% NH4OH volume:volume in aqueous solution, then six deionized water rinses, then 0.5M EDTA, then six deionized water, then 15% H2O2/15% NH4OH, then six deionized water (one-half hour incubations in each wash). The surface of the fiber optic wafer is preferably coated to facilitate its use in the sequencing reactions. A coated surface is preferably optically transparent, allows for easy attachment of proteins and nucleic acids, and does not negatively affect the activity of immobilized proteins. In addition, the surface preferably minimizes non-specific absorption of macromolecules and increases the stability of linked macromolecules (e.g., attached nucleic acids and proteins). Suitable materials for coating the array include, e.g., plastic (e.g. polystyrene). The plastic can be preferably spin-coated or sputtered (0.1 μm thickness). Other materials for coating the array include gold layers, e.g. 24 karat gold, 0.1 μm thickness, with adsorbed self-assembling monolayers of long chain thiol alkanes. Biotin is then coupled covalently to the surface and saturated with a biotin-binding protein (e.g. streptavidin or avidin). Coating materials can additionally include those systems used to attach an anchor primer to a substrate. Organosilane reagents, which allow for direct covalent coupling of proteins via amino, sulfhydryl or carboxyl groups, can also be used to coat the array. Additional coating substances include photoreactive linkers, e.g. photobiotin, (Amos et al., “Biomaterial Surface Modification Using Photochemical Coupling Technology,” in Encyclopedic Handbook of Biomaterials and Bioengineering, Part A: Materials, Wise et al. (eds.), New York, Marcel Dekker, pp. 895926, 1995). Additional coating materials include hydrophilic polymer gels (polyacrylamide, polysaccharides), which preferably polymerize directly on the surface or polymer chains covalently attached post polymerization (Hjerten, J. Chromatogr. 347,191 (1985); Novotny, Anal. Chem. 62,2478 (1990), as well as pluronic polymers (triblock copolymers, e.g. PPO-PEO-PPO, also known as F-108), specifically adsorbed to either polystyrene or silanized glass surfaces (Ho et al., Langmuir 14:3889-94, 1998), as well as passively adsorbed layers of biotin-binding proteins. The surface can also be coated with an epoxide which allows the coupling of reagents via an amine linkage. In addition, any of the above materials can be derivatized with one or more functional groups, commonly known in the art for the immobilization of enzymes and nucleotides, e.g. metal chelating groups (e.g. nitrilo triacetic acid, iminodiacetic acid, pentadentate chelator), which will bind 6×His-tagged proteins and nucleic acids. Surface coatings can be used that increase the number of available binding sites for subsequent treatments, e.g. attachment of enzymes (discussed later), beyond the theoretical binding capacity of a 2D surface. In a preferred embodiment, the individual optical fibers utilized to generate the fused optical fiber bundle/wafer are larger in diameter (i.e., 6 μm to 12 μm) than those utilized in the optical imaging system (i.e., 3 μm). Thus, several of the optical imaging fibers can be utilized to image a single reaction site. In a particularly preferred embodiment, the sample cartridge for nucleic acid templete sequencing, termed the ‘PicoTiter plate’ is formed from a commercial fiber optics faceplate, acid-etched to yield well structures. Each optic fiber core is about 44 microns in diameter, with a 2-3 micron cladding, each well formed by acid etching to form a reaction well volume of about 65 pL to 85 pL, most preferably about 75 pL. The use of etched wells on a fiber optics faceplate surface serves a threefold purpose; i) delayed diffusion of the luminescence from emitting light in a different region of the array, ii) isolation of reaction chambers (“test-tubes”) that contain the amplified template molecules, and iii) very efficient, high numerical aperture optical coupling to the CCD. Finally, the larger the amount of sequencing template immobilized within a well, the more optical signal one is able to achieve. Delivery Means An example of the means for delivering reactants to the reaction chamber is the perfusion chamber of the present invention is illustrated in FIG. 13. The perfusion chamber includes a sealed compartment with transparent upper and lower side. It is designed to allow flow of solution over the surface of the substrate surface and to allow for fast exchange of reagents. Thus, it is suitable for carrying out, for example, the pyrophosphate sequencing reactions. The shape and dimensions of the chamber can be adjusted to optimize reagent exchange to include bulk flow exchange, diffusive exchange, or both in either a laminar flow or a turbulent flow regime. The perfusion chamber is preferably detached from the imaging system while it is being prepared and only placed on the imaging system when sequencing analysis is performed. In one embodiment, the solid support (i.e., a DNA chip or glass slide) is held in place by a metal or plastic housing, which may be assembled and disassembled to allow replacement of said solid support. The lower side of the solid support of the perfusion chamber carries the reaction chamber array and, with a traditional optical-based focal system, a high numerical aperture objective lens is used to focus the image of the reaction center array onto the CCD imaging system. Many samples can thereby be analyzed in parallel. Using the method of the invention, many nucleic acid templates may be analyzed in this was by allowing the solution containing the enzymes and one nucleotide to flow over the surface and then detecting the signal produced for each sample. This procedure can then be repeated. Alternatively, several different oligonucleotides complementary to the template may be distributed over the surface followed by hybridization of the template. Incorporation of deoxynucleotides or dideoxynucleotides may be monitored for each oligonucleotide by the signal produced using the various oligonucleotides as primer. By combining the signals from different areas of the surface, sequence-based analyses may be performed by four cycles of polymerase reactions using the various dideoxynucleotides. When the support is in the form of a cavitated array, e.g., in the termini of a picotiter plate or other array of microwells, suitable delivery means for reagents include flowing and washing and also, e.g., flowing, spraying, electrospraying, ink jet delivery, stamping, ultrasonic atomization (Sonotek Corp., Milton, N.Y.) and rolling. When spraying is used, reagents may be delivered to the picotiter plate in a homogeneous thin layer produced by industrial type spraying nozzles (Spraying Systems, Co., Wheaton, Ill.) or atomizers used in thin layer chromatography (TLC), such as CAMAG TLC Sprayer (Camag Scientific Inc., Wilmington, N.C.). These sprayers atomize reagents into aerosol spray particles in the size range of 0.3 to 10 μm. Successive reagent delivery steps are preferably separated by wash steps using techniques commonly known in the art. These washes can be performed, e.g., using the above described methods, including high-flow sprayers or by a liquid flow over the picotiter plate or microwell array surface. The washes can occur in any time period after the starting material has reacted with the reagent to form a product in each reaction chamber but before the reagent delivered to any one reaction chamber has diffused out of that reaction chamber into any other reaction chamber. In one embodiment, any one reaction chamber is independent of the product formed in any other reaction chamber, but is generated using one or more common reagents. An embodiment of a complete apparatus is illustrated in FIG. 12. The apparatus includes an inlet conduit 200 in communication with a detachable perfusion chamber 226. The inlet conduit 200 allows for entry of sequencing reagents via a plurality of tubes 202-212, which are each in communication with a plurality of sequencing dispensing reagent vessels 214-224. Reagents are introduced through the conduit 200 into the perfusion chamber 226 using either a pressurized system or pumps to drive positive flow. Typically, the reagent flow rates are from 0.05 to 50 ml/minute (e.g., 1 to 50 ml/minute) with volumes from 0.100 ml to continuous flow (for washing). Valves are under computer control to allow cycling of nucleotides and wash reagents. Sequencing reagents, e.g., polymerase can be either pre-mixed with nucleotides or added in stream. A manifold brings all six tubes 202-212 together into one for feeding the perfusion chamber. Thus several reagent delivery ports allow access to the perfusion chamber. For example, one of the ports may be utilized to allow the input of the aqueous sequencing reagents, while another port allows these reagents (and any reaction products) to be withdrawn from the perfusion chamber. In a preferred embodiment, one or more reagents are delivered to an array immobilized or attached to a population of mobile solid supports, e.g., a bead or microsphere. The bead or microsphere need not be spherical, irregular shaped beads may be used. They are typically constructed from numerous substances, e.g., plastic, glass or ceramic and bead sizes ranging from nanometers to millimeters depending on the width of the reaction chamber. Various bead chemistries can be used e.g., methylstyrene, polystyrene, acrylic polymer, latex, paramagnetic, thoria sol, carbon graphite and titanium dioxide. The construction or chemistry of the bead can be chosen to facilitate the attachment of the desired reagent. In another embodiment, the bioactive agents are synthesized first, and then covalently attached to the beads. As is appreciated by someone skilled in the art, this will be done depending on the composition of the bioactive agents and the beads. The functionalization of solid support surfaces such as certain polymers with chemically reactive groups such as thiols, amines, carboxyls, etc. is generally known in the art. In a preferred embodiment, the nucleic acid template is delivered to the picotiter plate on beads. The luciferase and sulfurylase enzymes are likewise delivered to each well on beads (see Figure), as is the DNA polymerase. It is noted that the one or more of the nucleic acid template, luciferase and sulfurylase may be delivered each on separate beads, or together on the same bead. To allow sequencing DNA at raised temperatures, we have cloned and modified the thermostable sulfurylase from Bacillus steareothermophilus. We have also cloned and modified several luciferase enzymes for solid-phase enzyme activity, including P. pennsylvanica and P. pyralis. The P. pyralis luciferase is used in a preferred embodiment. “Blank” beads may be used that have surface chemistries that facilitate the attachment of the desired functionality by the user. Additional examples of these surface chemistries for blank beads include, but are not limited to, amino groups including aliphatic and aromatic amines, carboxylic acids, aldehydes, amides, chloromethyl groups, hydrazide, hydroxyl groups, sulfonates and sulfates. These functional groups can be used to add any number of different candidate agents to the beads, generally using known chemistries. For example, candidate agents containing carbohydrates may be attached to an amino-functionalized support; the aldehyde of the carbohydrate is made using standard techniques, and then the aldehyde is reacted with an amino group on the surface. In an alternative embodiment, a sulfhydryl linker may be used. There are a number of sulfhydryl reactive linkers known in the art such as SPDP, maleimides, α-haloacetyls, and pyridyl disulfides (see for example the 1994 Pierce Chemical Company catalog, technical section on cross-linkers, pages 155-200, incorporated here by reference) which can be used to attach cysteine containing proteinaceous agents to the support. Alternatively, an amino group on the candidate agent may be used for attachment to an amino group on the surface. For example, a large number of stable bifunctional groups are well known in the art, including homobifunctional and heterobifunctional linkers (see Pierce Catalog and Handbook, pages 155-200). In an additional embodiment, carboxyl groups (either from the surface or from the candidate agent) may be derivatized using well known linkers (see Pierce catalog). For example, carbodiimides activate carboxyl groups for attack by good nucleophiles such as amines (see Torchilin et al., Critical Rev. Thereapeutic Drug Carrier Systems, 7(4):275-308 (1991)). Proteinaceous candidate agents may also be attached using other techniques known in the art, for example for the attachment of antibodies to polymers; see Slinkin et al., Bioconj. Chem. 2:342-348 (1991); Torchilin et al., supra; Trubetskoy et al., Bioconj. Chem. 3:323-327 (1992); King et al., Cancer Res. 54:6176-6185 (1994); and Wilbur et al., Bioconjugate Chem. 5:220-235 (1994). It should be understood that the candidate agents may be attached in a variety of ways, including those listed above. Preferably, the manner of attachment does not significantly alter the functionality of the candidate agent; that is, the candidate agent should be attached in such a flexible manner as to allow its interaction with a target. Specific techniques for immobilizing enzymes on beads are known in the prior art. In one case, NH2 surface chemistry beads are used. Surface activation is achieved with a 2.5% glutaraldehyde in phosphate buffered saline (10 mM) providing a pH of 6.9 (138 mM NaCl, 2.7 mM KCl). This mixture is stirred on a stir bed for approximately 2 hours at room temperature. The beads are then rinsed with ultrapure water plus 0.01% Tween 20 (surfactant)-0.02%, and rinsed again with a pH 7.7 PBS plus 0.01% tween 20. Finally, the enzyme is added to the solution, preferably after being prefiltered using a 0.45 μm amicon micropure filter. The population of mobile solid supports are disposed in the reaction chambers. In some embodiments, 5% to 20% of the reaction chambers can have a mobile solid support with at least one reagent immobilized thereon, 20% to 60% of the reaction chambers can have a mobile solid support with at least one reagent immobilized thereon or 50% to 100% of the reaction chambers can have a mobile solid support with at least one reagent immobilized thereon. Preferably, at least one reaction chamber has a mobile solid support having at least one reagent immobilized thereon and the reagent is suitable for use in a nucleic acid sequencing reaction. In some embodiments, the reagent immobilized to the mobile solid support can be a polypeptide with sulfinurylase activity, a polypeptide with luciferase activity or a chimeric polypeptide having both sulfurylase and luciferase activity. In one embodiment, it can be a ATP sulfurylase and luciferase fusion protein. Since the product of the sulfurylase reaction is consumed by luciferase, proximity between these two enzymes may be achieved by covalently linking the two enzymes in the form of a fusion protein. This invention would be useful not only in substrate channeling but also in reducing production costs and potentially doubling the number of binding sites on streptavidin-coated beads. In another embodiment, the sulfurylase is a thermostable ATP sulfurylase. In a preferred embodiment, the thermostable sulfurylase is active at temperatures above ambient (to at least 50° C.). In one embodiment, the ATP sulfurylase is from a thermophile. In an additional embodiment, the mobile solid support can have a first reagent and a second reagent immobilized thereon, the first reagent is a polypeptide with sulfurylase activity and the second reagent is a polypeptide with luciferase activity. In another embodiment, the reagent immobilized to the mobile solid support can be a nucleic acid; preferably the nucleic acid is a single stranded concatamer. In a preferred embodiment, the nucleic acid can be used for sequencing a nucleic acid, e.g., a pyrosequencing reaction. The invention also provides a method for detecting or quantifying ATP activity using a mobile solid support; preferably the ATP can be detected or quantified as part of a nucleic acid sequencing reaction. A picotiter plate that has been “carpeted” with mobile solid supports with either nucleic acid or reagent enzymes attached thereto is shown as FIG. 15. 5. Methods of Sequencing Nucleic Acids Pyrophosphate-based sequencing is then performed. The sample DNA sequence and the extension primer are then subjected to a polymerase reaction in the presence of a nucleotide triphosphate whereby the nucleotide triphosphate will only become incorporated and release pyrophosphate (PPi) if it is complementary to the base in the target position, the nucleotide triphosphate being added either to separate aliquots of sample-primer mixture or successively to the same sample-primer mixture. The release of PPi is then detected to indicate which nucleotide is incorporated. In one embodiment, a region of the sequence product is determined by annealing a sequencing primer to a region of the template nucleic acid, and then contacting the sequencing primer with a DNA polymerase and a known nucleotide triphosphate, i.e., dATP, dCTP, dGTP, dTTP, or an analog of one of these nucleotides. The sequence can be determined by detecting a sequence reaction byproduct, as is described below. The sequence primer can be any length or base composition, as long as it is capable of specifically annealing to a region of the amplified nucleic acid template. No particular structure for the sequencing primer is required so long as it is able to specifically prime a region on the amplified template nucleic acid. Preferably, the sequencing primer is complementary to a region of the template that is between the sequence to be characterized and the sequence hybridizable to the anchor primer. The sequencing primer is extended with the DNA polymerase to form a sequence product. The extension is performed in the presence of one or more types of nucleotide triphosphates, and if desired, auxiliary binding proteins. Incorporation of the dNTP is preferably determined by assaying for the presence of a sequencing byproduct. In a preferred embodiment, the nucleotide sequence of the sequencing product is determined by measuring inorganic pyrophosphate (PPi) liberated from a nucleotide triphosphate (dNTP) as the dNMP is incorporated into an extended sequence primer. This method of sequencing, termed Pyrosequencing™ technology (PyroSequencing AB, Stockholm, Sweden) can be performed in solution (liquid phase) or as a solid phase technique. PPi-based sequencing methods are described generally in, e.g., WO9813523A1, Ronaghi, et al., 1996. Anal. Biochem. 242: 84-89, Ronaghi, et al., 1998. Science 281: 363-365 (1998) and U.S. Ser. No. 2001/0024790. These disclosures of PPi sequencing are incorporated herein in their entirety, by reference. See also, e.g., U.S. Pat. Nos. 6,210,891 and 6,258,568, each fully incorporated herein by reference. Pyrophosphate released under these conditions can be detected enzymatically (e.g., by the generation of light in the luciferase-luciferin reaction). Such methods enable a nucleotide to be identified in a given target position, and the DNA to be sequenced simply and rapidly while avoiding the need for electrophoresis and the use of potentially dangerous radiolabels. PPi can be detected by a number of different methodologies, and various enzymatic methods have been previously described (see e.g., Reeves, et al., 1969. Anal. Biochem. 28: 282-287; Guillory, et al., 1971. Anal. Biochem. 39: 170-180; Johnson, et al., 1968. Anal. Biochem. 15: 273; Cook, et al., 1978. Anal. Biochem. 91: 557-565; and Drake, et al., 1979. Anal. Biochem. 94: 117-120). PPi liberated as a result of incorporation of a dNTP by a polymerase can be converted to ATP using, e.g., an ATP sulfurylase. This enzyme has been identified as being involved in sulfur metabolism. Sulfur, in both reduced and oxidized forms, is an essential mineral nutrient for plant and animal growth (see e.g., Schmidt and Jager, 1992. Ann. Rev. Plant Physiol. Plant Mol. Biol. 43: 325-349). In both plants and microorganisms, active uptake of sulfate is followed by reduction to sulfide. As sulfate has a very low oxidation/reduction potential relative to available cellular reductants, the primary step in assimilation requires its activation via an ATP-dependent reaction (see e.g., Leyh, 1993. Crit. Rev. Biochem. Mol. Biol. 28: 515-542). ATP sulfurylase (ATP: sulfate adenylyltransferase; EC 2.7.7.4) catalyzes the initial reaction in the metabolism of inorganic sulfate (SO4−2); see e.g., Robbins and Lipmann, 1958. J. Biol. Chem. 233: 686-690; Hawes and Nicholas, 1973. Biochem. J. 133: 541-550). In this reaction SO4−2 is activated to adenosine 5′-phosphosulfate (APS). ATP sulfurylase has been highly purified from several sources, such as Saccharomyces cerevisiae (see e.g., Hawes and Nicholas, 1973. Biochem. J. 133: 541-550); Penicillium chrysogenum (see e.g., Renosto, et al., 1990. J. Biol. Chem. 265: 10300-10308); rat liver (see e.g., Yu, et al., 1989. Arch. Biochem. Biophys. 269: 165-174); and plants (see e.g., Shaw and Anderson, 1972. Biochem. J. 127: 237-247; Osslund, et al., 1982. Plant Physiol. 70: 39-45). Furthermore, ATP sulfurylase genes have been cloned from prokaryotes (see e.g., Leyh, et al., 1992. J. Biol. Chem. 267: 10405-10410; Schwedock and Long, 1989. Mol. Plant Microbe Interaction 2: 181-194; Laue and Nelson, 1994. J. Bacteriol. 176: 3723-3729); eukaryotes (see e.g., Cherest, et al., 1987. Mol. Gen. Genet. 210: 307-313; Mountain and Korch, 1991. Yeast 7: 873-880; Foster, et al., 1994. J. Biol. Chem. 269: 19777-19786); plants (see e.g., Leustek, et al., 1994. Plant Physiol. 105: 897-90216); and animals (see e.g., Li, et al., 1995. J. Biol. Chem. 270: 29453-29459). The enzyme is a homo-oligomer or heterodimer, depending upon the specific source (see e.g., Leyh and Suo, 1992. J. Biol. Chem. 267: 542-545). In some embodiments, a thermostable sulfurylase is used. Thermostable sulfurylases can be obtained from, e.g., Archaeoglobus or Pyrococcus spp. Sequences of thermostable sulfurylases are available at database Acc. No. 028606, Acc. No. Q9YCR4, and Acc. No. P56863. ATP sulfurylase has been used for many different applications, for example, bioluminometric detection of ADP at high concentrations of ATP (see e.g., Schultz, et al., 1993. Anal. Biochem. 215: 302-304); continuous monitoring of DNA polymerase activity (see e.g., Nyrbn, 1987. Anal. Biochem. 167: 235-238); and DNA sequencing (see e.g., Ronaghi, et al., 1996. Anal. Biochem. 242: 84-89; Ronaghi, et al., 1998. Science 281: 363-365; Ronaghi, et al., 1998. Anal. Biochem. 267: 65-71). Several assays have been developed for detection of the forward ATP sulfurylase reaction. The colorimetric molybdolysis assay is based on phosphate detection (see e.g., Wilson and Bandurski, 1958. J. Biol. Chem. 233: 975-981), whereas the continuous spectrophotometric molybdolysis assay is based upon the detection of NADH oxidation (see e.g., Seubert, et al., 1983. Arch. Biochem. Biophys. 225: 679-691; Seubert, et al., 1985. Arch. Biochem. Biophys. 240: 509-523). The later assay requires the presence of several detection enzymes. In addition, several radioactive assays have also been described in the literature (see e.g., Daley, et al., 1986. Anal. Biochem. 157: 385-395). For example, one assay is based upon the detection of 32PPi released from 32P-labeled ATP (see e.g., Seubert, et al., 1985. Arch. Biochem. Biophys. 240: 509-523) and another on the incorporation of 35S into [35S]-labeled APS (this assay also requires purified APS kinase as a coupling enzyme; see e.g., Seubert, et al., 1983. Arch. Biochem. Biophys. 225: 679-691); and a third reaction depends upon the release of 35SO4−2 from [35S]-labeled APS (see e.g., Daley, et al., 1986. Anal. Biochem. 157: 385-395). For detection of the reversed ATP sulfurylase reaction a continuous spectrophotometric assay (see e.g., Segel, et al., 1987. Methods Enzymol. 143: 334-349); a bioluminometric assay (see e.g., Balharry and Nicholas, 1971. Anal. Biochem. 40: 1-17); an 35SO4−2 release assay (see e.g., Seubert, et al., 1985. Arch. Biochem. Biophys. 240: 509-523); and a 32PPi incorporation assay (see e.g., Osslund, et al., 1982. Plant Physiol. 70: 39-45) have been previously described. ATP produced by an ATP sulfurylase can be hydrolyzed using enzymatic reactions to generate light. Light-emitting chemical reactions (i.e., chemiluminescence) and biological reactions (i.e., bioluminescence) are widely used in analytical biochemistry for sensitive measurements of various metabolites. In bioluminescent reactions, the chemical reaction that leads to the emission of light is enzyme-catalyzed. For example, the luciferin-luciferase system allows for specific assay of ATP and the bacterial luciferase-oxidoreductase system can be used for monitoring of NAD(P)H. Both systems have been extended to the analysis of numerous substances by means of coupled reactions involving the production or utilization of ATP or NAD(P)H (see e.g., Kricka, 1991. Chemiluminescent and bioluminescent techniques. Clin. Chem. 37: 1472-1281). The development of new reagents have made it possible to obtain stable light emission proportional to the concentrations of ATP (see e.g., Lundin, 1982. Applications of firefly luciferase In; Luminescent Assays (Raven Press, New York) or NAD(P)H (see e.g., Lovgren, et al., Continuous monitoring of NADH-converting reactions by bacterial luminescence. J. Appl. Biochem. 4: 103-111). With such stable light emission reagents, it is possible to make endpoint assays and to calibrate each individual assay by addition of a known amount of ATP or NAD(P)H. In addition, a stable light-emitting system also allows continuous monitoring of ATP- or NAD(P)H-converting systems. Suitable enzymes for converting ATP into light include luciferases, e.g., insect luciferases. Luciferases produce light as an end-product of catalysis. The best known light-emitting enzyme is that of the firefly, Photinus pyralis (Coleoptera). The corresponding gene has been cloned and expressed in bacteria (see e.g., de Wet, et al., 1985. Proc. Natl. Acad. Sci. USA 80: 7870-7873) and plants (see e.g., Ow, et al., 1986. Science 234: 856-859), as well as in insect (see e.g., Jha, et al., 1990. FEBS Lett. 274: 24-26) and mammalian cells (see e.g., de Wet, et al., 1987. Mol. Cell. Biol. 7: 725-7373; Keller, et al., 1987. Proc. Natl. Acad. Sci. USA 82: 3264-3268). In addition, a number of luciferase genes from the Jamaican click beetle, Pyroplorus plagiophihalamus (Coleoptera), have recently been cloned and partially characterized (see e.g., Wood, et al., 1989. J. Biolumin. Chemilumin. 4: 289-301; Wood, et al., 1989. Science 244: 700-702). Distinct luciferases can sometimes produce light of different wavelengths, which may enable simultaneous monitoring of light emissions at different wavelengths. Accordingly, these aforementioned characteristics are unique, and add new dimensions with respect to the utilization of current reporter systems. Firefly luciferase catalyzes bioluminescence in the presence of luciferin, adenosine 5′-triphosphate (ATP), magnesium ions, and oxygen, resulting in a quantum yield of 0.88 (see e.g., McElroy and Selinger, 1960. Arch. Biochem. Biophys. 88: 136-145). The firefly luciferase bioluminescent reaction can be utilized as an assay for the detection of ATP with a detection limit of approximately 1×10−13 M (see e.g., Leach, 1981. J. Appl. Biochem. 3: 473-517). In addition, the overall degree of sensitivity and convenience of the luciferase-mediated detection systems have created considerable interest in the development of firefly luciferase-based biosensors (see e.g., Green and Kricka, 1984. Talanta 31: 173-176; Blum, et al., 1989. J Biolumin. Chemilumin. 4: 543-550). Using the above-described enzymes, the sequence primer is exposed to a polymerase and a known dNTP. If the dNTP is incorporated onto the 3′ end of the primer sequence, the dNTP is cleaved and a PPi molecule is liberated. The PPi is then converted to ATP with ATP sulfurylase. Preferably, the ATP sulfurylase is present at a sufficiently high concentration that the conversion of PPi proceeds with first-order kinetics with respect to PPi. In the presence of luciferase, the ATP is hydrolyzed to generate a photon. The reaction preferably has a sufficient concentration of luciferase present within the reaction mixture such that the reaction, ATP→DP+PO43−+photon (light), proceeds with first-order kinetics with respect to ATP. The photon can be measured using methods and apparatuses described below. In one embodiment, the PPi and a coupled sulfurylase/luciferase reaction is used to generate light for detection. In some embodiments, either or both the sulfurylase and luciferase are immobilized on one or more mobile solid supports disposed at each reaction site. The present invention thus permits PPi release to be detected during the polymerase reaction giving a real-time signal. The sequencing reactions may be continuously monitored in real-time. A procedure for rapid detection of PPi release is thus enabled by the present invention. The reactions have been estimated to take place in less than 2 seconds (Nyren and Lundin, supra). The rate limiting step is the conversion of PPi to ATP by ATP sulftirylase, while the luciferase reaction is fast and has been estimated to take less than 0.2 seconds. Incorporation rates for polymerases have also been estimated by various methods and it has been found, for example, that in the case of Klenow polymerase, complete incorporation of one base may take less than 0.5 seconds. Thus, the estimated total time for incorporation of one base and detection by this enzymatic assay is approximately 3 seconds. It will be seen therefore that very fast reaction times are possible, enabling real-time detection. The reaction times could further be decreased by using a more thermostable luciferase. For most applications it is desirable to use reagents free of contaminants like ATP and PPi. These contaminants may be removed by flowing the reagents through a pre-column containing apyrase and/-or pyrophosphatase bound to resin. Alternatively, the apyrase or pyrophosphatase can be bound to magnetic beads and used to remove contaminating ATP and PPi present in the reagents. In addition it is desirable to wash away diffusible sequencing reagents, e.g., unincorporated dNTPs, with a wash buffer. Any wash buffer used in pyrophosphate sequencing can be used. In some embodiments, the concentration of reactants in the sequencing reaction include 1 pmol DNA, 3 pmol polymerase, 40 pmol dNTP in 0.2 ml buffer. See Ronaghi, et al., Anal. Biochem. 242: 84-89 (1996). The sequencing reaction can be performed with each of four predetermined nucleotides, if desired. A “complete” cycle generally includes sequentially administering sequencing reagents for each of the nucleotides DATP, dGTP, dCTP and dTTP (or dUTP), in a predetermined order. Unincorporated dNTPs are washed away between each of the nucleotide additions. Alternatively, unincorporated dNTPs are degraded by apyrase (see below). The cycle is repeated as desired until the desired amount of sequence of the sequence product is obtained. In some embodiments, about 10-1000, 10-100, 10-75, 20-50, or about 30 nucleotides of sequence information is obtained from extension of one annealed sequencing primer. In some embodiments, the nucleotide is modified to contain a disulfide-derivative of a hapten such as biotin. The addition of the modified nucleotide to the nascent primer annealed to the anchored substrate is analyzed by a post-polymerization step that includes i) sequentially binding of, in the example where the modification is a biotin, an avidin- or streptavidin-conjugated moiety linked to an enzyme molecule, ii) the washing away of excess avidin- or streptavidin-linked enzyme, iii) the flow of a suitable enzyme substrate under conditions amenable to enzyme activity, and iv) the detection of enzyme substrate reaction product or products. The hapten is removed in this embodiment through the addition of a reducing agent. Such methods enable a nucleotide to be identified in a given target position, and the DNA to be sequenced simply and rapidly while avoiding the need for electrophoresis and the use of potentially dangerous radiolabels. A preferred enzyme for detecting the hapten is horse-radish peroxidase. If desired, a wash buffer, can be used between the addition of various reactants herein. Apyrase can be used to remove unreacted dNTP used to extend the sequencing primer. The wash buffer can optionally include apyrase. Example haptens, e.g., biotin, digoxygenin, the fluorescent dye molecules cy3 and cy5, and fluorescein, are incorporated at various efficiencies into extended DNA molecules. The attachment of the hapten can occur through linkages via the sugar, the base, and via the phosphate moiety on the nucleotide. Example means for signal amplification include fluorescent, electrochemical and enzymatic. In a preferred embodiment using enzymatic amplification, the enzyme, e.g. alkaline phosphatase (AP), horse-radish peroxidase (HRP), beta-galactosidase, luciferase, can include those for which light-generating substrates are known, and the means for detection of these light-generating (chemiluminescent) substrates can include a CCD camera. In a preferred mode, the modified base is added, detection occurs, and the hapten-conjugated moiety is removed or inactivated by use of either a cleaving or inactivating agent. For example, if the cleavable-linker is a disulfide, then the cleaving agent can be a reducing agent, for example dithiothreitol (DTT), beta-mercaptoethanol, etc. Other embodiments of inactivation include heat, cold, chemical denaturants, surfactants, hydrophobic reagents, and suicide inhibitors. Luciferase can hydrolyze dATP directly with concomitant release of a photon. This results in a false positive signal because the hydrolysis occurs independent of incorporation of the dATP into the extended sequencing primer. To avoid this problem, a dATP analog can be used which is incorporated into DNA, i.e., it is a substrate for a DNA polymerase, but is not a substrate for luciferase. One such analog is α-thio-dATP. Thus, use of α-thio-dATP avoids the spurious photon generation that can occur when dATP is hydrolyzed without being incorporated into a growing nucleic acid chain. Typically, the PPi-based detection is calibrated by the measurement of the light released following the addition of control nucleotides to the sequencing reaction mixture immediately after the addition of the sequencing primer. This allows for normalization of the reaction conditions. Incorporation of two or more identical nucleotides in succession is revealed by a corresponding increase in the amount of light released. Thus, a two-fold increase in released light relative to control nucleotides reveals the incorporation of two successive dNTPs into the extended primer. If desired, apyrase may be “washed” or “flowed” over the surface of the solid support so as to facilitate the degradation of any remaining, non-incorporated dNTPs within the sequencing reaction mixture. Apyrase also degrades the generated ATP and hence “turns off” the light generated from the reaction. Upon treatment with apyrase, any remaining reactants are washed away in preparation for the following dNTP incubation and photon detection steps. Alternatively, the apyrase may be bound to the solid or mobile solid support. Double Ended Sequencing In a preferred embodiment we provide a method for sequencing from both ends of a nucleic acid template. Traditionally, the sequencing of two ends of a double stranded DNA molecule would require at the very least the hybridization of primer, sequencing of one end, hybridization of a second primer, and sequencing of the other end. The alternative method is to separate the individual strands of the double stranded nucleic acid and individually sequence each strand. The present invention provides a third alternative that is more rapid and less labor intensive than the first two methods. The present invention provides for a method of sequential sequencing of nucleic acids from multiple primers. References to DNA sequencing in this application are directed to sequencing using a polymerase wherein the sequence is determined as the nucleotide triphosphate (NTP) is incorporated into the growing chain of a sequencing primer. One example of this type of sequencing is the pyro-sequencing detection pyrophosphate method (see, e.g., U.S. Pat. Nos. 6,274,320, 6258,568 and 6,210,891, each of which is incorporated in total herein by reference.). In one embodiment, the present invention provides for a method for sequencing two ends of a template double stranded nucleic acid. The double stranded DNA is comprised of two single stranded DNA; referred to herein as a first single stranded DNA and a second single stranded DNA. A first primer is hybridized to the first single stranded DNA and a second primer is hybridized to the second single stranded DNA. The first primer is unprotected while the second primer is protected. “Protection” and “protected” are defined in this disclosure as being the addition of a chemical group to reactive sites on the primer that prevents a primer from polymerization by DNA polymerase. Further, the addition of such chemical protecting groups should be reversible so that after reversion, the now deprotected primer is once again able to serve as a sequencing primer. The nucleic acid sequence is determined in one direction (e.g., from one end of the template) by elongating the first primer with DNA polymerase using conventional methods such as pyrophosphate sequencing. The second primer is then deprotected, and the sequence is determined by elongating the second primer in the other direction (e.g., from the other end of the template) using DNA polymerase and conventional methods such as pyrophosphate sequencing. The sequences of the first and second primers are specifically designed to hybridize to the two ends of the double stranded DNA or at any location along the template in this method. In another embodiment, the present invention provides for a method of sequencing a nucleic acid from multiple primers. In this method a number of sequencing primers are hybridized to the template nucleic acid to be sequenced. All the sequencing primers are reversibly protected except for one. A protected primer is an oligonucleotide primer that cannot be extended with polymerase and dNTPs which are commonly used in DNA sequencing reactions. A reversibly protected primer is a protected primer which can be deprotected. All protected primers referred to in this invention are reversibly protected. After deprotection, a reversibly protected primer functions as a normal sequencing primer and is capable of participating in a normal sequencing reaction. The present invention provides for a method of sequential sequencing a nucleic acid from multiple primers. The method comprises the following steps: First, one or more template nucleic acids to be sequenced are provided. Second, a plurality of sequencing primers are hybridized to the template nucleic acid or acids. The number of sequencing primers may be represented by the number n where n can be any positive number greater than 1. That number may be, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10 or greater. Of the primers, n−1 number may be protected by a protection group. So, for example, if n is 2, 3, 4, 5, 6, 7, 8, 9 or 10, n−1 would be 1, 2, 3, 4, 5, 6, 7, 8, 9 respectively. The remaining primer (e.g., n number primers−(n−1) number of protected primers=one remaining primer) is unprotected. Third, the unprotected primer is extended and the template DNA sequence is determined by conventional methods such as, for example, pyrophosphate sequencing. Fourth, after the sequencing of the first primer, one of the remaining protected primers is unprotected. Fifth, unprotected primer is extended and the template DNA sequence is determined by conventional methods such as, for example, pyrophosphate sequencing. Optionally, the method may be repeated until sequencing is performed on all the protected primers. In another aspect, the present invention includes a method of sequential sequencing of a nucleic acid comprising the steps of: (a) hybridizing 2 or more sequencing primers to the nucleic acid wherein all the primers except for one are reversibly protected; (b) determining a sequence of one strand of the nucleic acid by polymerase elongation from the unprotected primer; (c) deprotecting one of the reversibly protected primers into an unprotected primer; (d) repeating steps (b) and (c) until all the reversibly protected primers are deprotected and used for determining a sequence. In one embodiment, this method comprises one additional step between steps (b) and (c), i.e., the step of terminating the elongation of the unprotected primer by contacting the unprotected primer with DNA polymerase and one or more of a nucleotide triphosphate or a dideoxy nucleotide triphosphate. In yet another embodiment, this method further comprises an additional step between said step (b) and (c), i.e., terminating the elongation of the unprotected primer by contacting the unprotected primer with DNA polymerase and a dideoxy nucleotide triphosphate from ddATP, ddTTP, ddCTP, ddGTP or a combination thereof. In another aspect, this invention includes a method of sequencing a nucleic acid comprising: (a) hybridizing a first unprotected primer to a first strand of the nucleic acid; (b) hybridizing a second protected primer to a second strand; (c) exposing the first and second strands to polymerase, such that the first unprotected primer is extended along the first strand; (d) completing the extension of the first sequencing primer; (e) deprotecting the second sequencing primer; and (f) exposing the first and second strands to polymerase so that the second sequencing primer is extended along the second strand. In a preferred embodiment, completing comprises capping or terminating the elongation. In another embodiment, the present invention provides for a method for sequencing two ends of a template double stranded nucleic acid that comprises a first and a second single stranded DNA. In this embodiment, a first primer is hybridized to the first single stranded DNA and a second primer is hybridized to the second single stranded DNA in the same step. The first primer is unprotected while the second primer is protected. Following hybridization, the nucleic acid sequence is determined in one direction (e.g., from one end of the template) by elongating the first primer with DNA polymerase using conventional methods such as pyrophosphate sequencing. In a preferred embodiment, the polymerase is devoid of 3′ to 5′ exonuclease activity. The second primer is then deprotected, and its sequence is determined by elongating the second primer in the other direction (e.g., from the other end of the template) with DNA polymerase using conventional methods such as pyrophosphate sequencing. As described earlier, the sequences of the first primer and the second primer are designed to hybridize to the two ends of the double stranded DNA or at any location along the template. This technique is especially useful for the sequencing of many template DNAs that contain unique sequencing primer hybridization sites on its two ends. For example, many cloning vectors provide unique sequencing primer hybridization sites flanking the insert site to facilitate subsequent sequencing of any cloned sequence (e.g., Bluescript, Stratagene, La Jolla, Calif.). One benefit of this method of the present invention is that both primers may be hybridized in a single step. The benefits of this and other methods are especially useful in parallel sequencing systems where hybridizations are more involved than normal. Examples of parallel sequencing systems are disclosed in copending U.S. patent application Ser. No. 10/104,280, the disclosure of which is incorporated in total herein. The oligonucleotide primers of the present invention may be synthesized by conventional technology, e.g., with a commercial oligonucleotide synthesizer and/or by ligating together subfragments that have been so synthesized. In another embodiment of the invention, the length of the double stranded target nucleic acid may be determined. Methods of determining the length of a double stranded nucleic acid are known in the art. The length determination may be performed before or after the nucleic acid is sequenced. Known methods of nucleic acid molecule length determination include gel electrophoresis, pulsed field gel electrophoresis, mass spectroscopy and the like. Since a blunt ended double stranded nucleic acid is comprised of two single strands of identical lengths, the determination of the length of one strand of a nucleic acid is sufficient to determine the length of the corresponding double strand. The sequence reaction according to the present invention also allows a determination of the template nucleic acid length. First, a complete sequence from one end of the nucleic acid to another end will allow the length to be determined. Second, the sequence determination of the two ends may overlap in the middle allowing the two sequences to be linked. The complete sequence may be determined and the length may be revealed. For example, if the template is 100 bps long, sequencing from one end may determine bases 1 to 75; sequencing from the other end may determine bases 25 to 100; there is thus a 51 base overlap in the middle from base 25 to base 75; and from this information, the complete sequence from 1 to 100 may be determined and the length, of 100 bases, may be revealed by the complete sequence. Another method of the present invention is directed to a method comprising the following steps. First a plurality of sequencing primers, each with a different sequence, is hybridized to a DNA to be sequenced. The number of sequencing primers may be any value greater than one such as, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more. All of these primers are reversibly protected except for one. The one unprotected primer is elongated in a sequencing reaction and a sequence is determined. Usually, when a primer is completely elongated, it cannot extend and will not affect subsequent sequencing from another primer. If desired, the sequenced primer may be terminated using excess polymerase and dNTP or using ddNTPs. If a termination step is taken, the termination reagents (dNTPs and ddNTPs) should be removed after the step. Then, one of the reversibly protected primers is unprotected and sequencing from the second primer proceeds. The steps of deprotecting a primer, sequencing from the deprotected primer, and optionally, terminating sequencing from the primer is repeated until all the protected primers are unprotected and used in sequencing. The reversibly protected primers should be protected with different chemical groups. By choosing the appropriate method of deprotection, one primer may be deprotected without affecting the protection groups of the other primers. In a preferred embodiment, the protection group is PO4. That is, the second primer is protected by PO4 and deprotection is accomplished by T4 polynucleotide kinase (utilizing its 3′-phosphatase activity). In another preferred embodiment, the protection is a thio group or a phosphorothiol group. The template nucleic acid may be a DNA, RNA, or peptide nucleic acid (PNA). While DNA is the preferred template, RNA and PNA may be converted to DNA by known techniques such as random primed PCR, reverse transcription, RT-PCR or a combination of these techniques. Further, the methods of the invention are useful for sequencing nucleic acids of unknown and known sequence. The sequencing of nucleic acid of known sequence would be useful, for example, for confirming the sequence of synthesized DNA or for confirming the identity of suspected pathogen with a known nucleic acid sequence. The nucleic acids may be a mixture of more than one population of nucleic acids. It is known that a sequencing primer with sufficient specificity (e.g., 20 bases, 25 bases, 30 bases, 35 bases, 40 bases, 45 bases, or 50 bases) may be used to sequence a subset of sequences in a long nucleic acid or in a population of unrelated nucleic acids. Thus, for example, the template may be one sequence of 10 Kb or ten sequences of 1 Kb each. In a preferred embodiment, the template DNA is between 50 bp to 700 bp in length. The DNA can be single stranded or double stranded. In the case where the template nucleic acid is single stranded, a number of primers may be hybridized to the template nucleic acid as shown below: In this case, it is preferred that the initial unprotected primer would be the primer that hybridizes at the most 5′ end of the template. See primer 1 in the above illustration. In this orientation, the elongation of primer 1 would not displace (by strand displacement) primer 2, 3, or 4. When sequencing from primer 1 is finished, primer 2 can be unprotected and nucleic acid sequencing can commence. The sequencing from primer 2 may displace primer 1 or the elongated version of primer one but would have no effect on the remaining protected primers (primers 3 and 4). Using this order, each primer may be used sequentially and a sequencing reaction from one primer would not affect the sequencing from a subsequent primer. One feature of the invention is the ability to use multiple sequencing primers on one or more nucleic acids and the ability to sequence from multiple primers using only one hybridization step. In the hybridization step, all the sequencing primers (e.g., the n number of sequencing primers) may be hybridized to the template nucleic acid(s) at the same time. In conventional sequencing, usually one hybridization step is required for sequencing from one primer. One feature of the invention is that the sequencing from n primers (as defined above) may be performed by a single hybridization step. This effectively eliminates n−1 hybridization step. In a preferred embodiment, the sequences of the n number of primers are sufficiently different that the primers do not cross hybridize or self-hybridize. Cross hybridization refers to the hybridization of one primer to another primer because of sequence complementarity. One form of cross hybridization is commonly referred to as a “primer dimer.” In the case of a primer dimer, the 3′ ends of two primers are complementary and form a structure that when elongated, is approximately the sum of the length of the two primers. Self-hybridization refers to the situation where the 5′ end of a primer is complementary to the 3′ end of the primer. In that case, the primer has a tendency to self hybridize to form a hairpin-like structure. A primer can interact or become associated specifically with the template molecule. By the terms “interact” or “associate”, it is meant herein that two substances or compounds (e.g., primer and template; chemical moiety and nucleotide) are bound (e.g., attached, bound, hybridized, joined, annealed, covalently linked, or otherwise associated) to one another sufficiently that the intended assay can be conducted. By the terms “specific” or “specifically”, it is meant herein that two components bind selectively to each other. The parameters required to achieve specific interactions can be determined routinely, e.g., using conventional methods in the art. To gain more sensitivity or to help in the analysis of complex mixtures, the protected primers can be modified (e.g., derivatized) with chemical moieties designed to give clear unique signals. For example, each protected primer can be derivatized with a different natural or synthetic amino acid attached through an amide bond to the oligonucleotide strand at one or more positions along the hybridizing portion of the strand. The chemical modification can be detected, of course, either after having been cleaved from the target nucleic acid, or while in association with the target nucleic acid. By allowing each protected target nucleic acid to be identified in a distinguishable manner, it is possible to assay (e.g., to screen) for a large number of different target nucleic acids in a single assay. Many such assays can be performed rapidly and easily. Such an assay or set of assays can be conducted, therefore, with high throughput efficiency as defined herein. In the methods of the invention, after a first primer is elongated and the sequence of the template DNA is determined, a second primer is deprotected and sequenced. There is no interference between the sequencing reaction of the first primer with the sequencing reaction of the second, now unprotected, primer because the first primer is completely elongated or terminated. Because the first primer is completely elongated, the sequencing from the second primer, using conventional methods such a pyrophosphate sequencing, will not be affected by the presence of the elongated first primer. The invention also provides a method of reducing any possible signal contamination from the first primer. Signal contamination refers to the incidences where the first primer is not completely elongated. In that case, the first primer will continue to elongate when a subsequent primer is deprotected and elongated. The elongation of both the first and second primers may interfere with the determination of DNA sequence. In a preferred embodiment, the sequencing reaction (e.g., the chain elongation reaction) from one primer is first terminated or completed before a sequencing reaction is started on a second primer. A chain elongation reaction of DNA can be terminated by contacting the template DNA with DNA polymerase and dideoxy nucleotide triphosphates (ddNTPs) such as ddATP, ddTTP, ddGTP and ddCTP. Following termination, the dideoxy nucleotide triphosphates may be removed by washing the reaction with a solution without ddNTPs. A second method of preventing further elongation of a primer is to add nucleotide triphosphates (dNTPs such as dATP, dTTP, dGTP and dCTP) and DNA polymerase to a reaction to completely extend any primer that is not completely extended. Following complete extension, the dNTPs and the polymerases are removed before the next primer is deprotected. By completing or terminating one primer before deprotecting another primer, the signal to noise ratio of the sequencing reaction (e.g., pyrophosphate sequencing) can be improved. The steps of (a) optionally terminating or completing the sequencing, (b) deprotecting a new primer, and (c) sequencing from the deprotected primer may be repeated until a sequence is determined from the elongation of each primer. In this method, the hybridization step comprises “n” number of primers and one unprotected primer. The unprotected primer is sequenced first and the steps of (a), (b) and (c) above may be repeated. In a preferred embodiment, pyrophosphate sequencing is used for all sequencing conducted in accordance with the method of the present invention. In another preferred embodiment, the double ended sequencing is performed according to the process outlined in FIG. 10. This process may be divided into six steps: (1) creation of a capture bead (FIG. 10A); (2) drive to bead (DTB) PCR amplification (FIG. 10B); (3) SL reporter system preparation (FIG. 10C); (4) sequencing of the first strand (FIG. 10D); (5) preparation of the second strand (FIGS. 10E and 10F); and (6) analysis of each strand (FIG. 10G). This exemplary process is outlined below. In step 1, an N-hydroxysuccinimide (NHS)-activated capture bead (e.g., Amersham Biosciences, Piscataway, N.J.) is coupled to both a forward primer and a reverse primer. NHS coupling forms a chemically stable amide bond with ligands containing primary amino groups. The capture bead is also coupled to biotin (FIG. 10A). The beads (i.e., solid nucleic acid capturing supports) used herein may be of any convenient size and fabricated from any number of known materials. Example of such materials include: inorganics, natural polymers, and synthetic polymers. Specific examples of these materials include: cellulose, cellulose derivatives, acrylic resins, glass; silica gels, polystyrene, gelatin, polyvinyl pyrrolidone, co-polymers of vinyl and acrylamide, polystyrene cross-linked with divinylbenzene or the like (see, Merrifield Biochemistry 1964, 3, 1385-1390), polyacrylamides, latex gels, polystyrene, dextran, rubber, silicon, plastics, nitrocellulose, celluloses, natural sponges, silica gels, glass, metals plastic, cellulose, cross-linked dextrans (e.g., Sephadex™) and agarose gel (Sepharose™) and solid phase supports known to those of skill in the art. In a preferred embodiment, the capture beads are Sepharose beads approximately 25 to 40 μM in diameter. In step 2, template DNA which has hybridized to the forward and reverse primers is added, and the DNA is amplified through a PCR amplification strategy (FIG. 10B). In one embodiment, the DNA is amplified by Emulsion Polymerase Chain Reaction, Drive to Bead Polymerase Chain Reaction, Rolling Circle Amplification or Loop-mediated Isothermal Amplification. In step 3, streptavidin is added followed by the addition of sulfurylase and luciferase which are coupled to the streptavidin (FIG. 10C). The addition of auxiliary enzymes during a sequencing method has been disclosed in U.S. Ser. No. 10/104,280 and U.S. Ser. No. 10/127,906, which are incorporated herein in their entireties by reference. In one embodiment, the template DNA has a DNA adaptor ligated to both the 5′ and 3′ end. In a preferred embodiment, the DNA is coupled to the DNA capture bead by hybridization of one of the DNA adaptors to a complimentary sequence on the DNA capture bead. In the first step, single stranded nucleic acid template to be amplified is attached to a capture bead. The nucleic acid template may be attached to the capture bead in any manner known in the art. Numerous methods exist in the art for attaching the DNA to a microscopic bead. Covalent chemical attachment of the DNA to the bead can be accomplished by using standard coupling agents, such as water-soluble carbodiimide, to link the 5′-phosphate on the DNA to amine-coated microspheres through a phosphoamidate bond. Another alternative is to first couple specific oligonucleotide linkers to the bead using similar chemistry, and to then use DNA ligase to link the DNA to the linker on the bead. Other linkage chemistries include the use of N-hydroxysuccinamide (NHS) and its derivatives, to join the oligonucleotide to the beads. In such a method, one end of the oligonucleotide may contain a reactive group (such as an amide group) which forms a covalent bond with the solid support, while the other end of the linker contains another reactive group which can bond with the oligonucleotide to be immobilized. In a preferred embodiment, the oligonucleotide is bound to the DNA capture bead by covalent linkage. However, non-covalent linkages, such as chelation or antigen-antibody complexes, may be used to join the oligonucleotide to the bead. Oligonucleotide linkers can be employed which specifically hybridize to unique sequences at the end of the DNA fragment, such as the overlapping end from a restriction enzyme site or the “sticky ends” of bacteriophage lambda based cloning vectors, but blunt-end ligations can also be used beneficially. These methods are described in detail in U.S. Pat. No. 5,674,743, the disclosure of which is incorporated in toto herein. It is preferred that any method used to immobilize the beads will continue to bind the immobilized oligonucleotide throughout the steps in the methods of the invention. In a preferred embodiment, the oligonucleotide is bound to the DNA capture bead by covalent linkage. However, non-covalent linkages, such as chelation or antigen-antibody complexes, may be used to join the oligonucleotide to the bead. In step 4, the first strand of DNA is sequenced by depositing the capture beads onto a PicoTiter plate (PTP), and sequencing by a method known to one of ordinary skill in the art (e.g., pyrophosphate sequencing) (FIG. 10D). Following sequencing, a mixture of dNTPs and ddNTPs are added in order to “cap” or terminate the sequencing process (FIG. 10E). In step 5, the second strand of nucleic acid is prepared by adding apyrase to remove the ddNTPs and polynucleotide kinase (PNK) to remove the 3′ phosphate group from the blocked primer strand (FIG. 10F). Polymerase is then added to prime the second strand followed by sequencing of the second strand according to a standard method known to one of ordinary skill in the art (FIG. 10G). In step 7, the sequence of the both the first and second strand is analyzed such that a contiguous DNA sequence is determined. Detection Means The solid support is optically linked to an imaging system 230, which includes a CCD system in association with conventional optics or a fiber optic bundle. In one embodiment the perfusion chamber substrate includes a fiber optic array wafer such that light generated near the aqueous interface is transmitted directly through the optical fibers to the exterior of the substrate or chamber. When the CCD system includes a fiber optic connector, imaging can be accomplished by placing the perfusion chamber substrate in direct contact with the connector. Alternatively, conventional optics can be used to image the light, e.g., by using a 1-1 magnification high numerical aperture lens system, from the exterior of the fiber optic substrate directly onto the CCD sensor. When the substrate does not provide for fiber optic coupling, a lens system can also be used as described above, in which case either the substrate or the perfusion chamber cover is optically transparent. An exemplary CCD imaging system is described above. The imaging system 230 is used to collect light from the reactors on the substrate surface. Light can be imaged, for example, onto a CCD using a high sensitivity low noise apparatus known in the art. For fiber-optic based imaging, it is preferable to incorporate the optical fibers directly into the cover slip or for a FORA to have the optical fibers that form the microwells also be the optical fibers that convey light to the detector. The imaging system is linked to a computer control and data collection system 240. In general, any commonly available hardware and software package can be used. The computer control and data collection system is also linked to the conduit 200 to control reagent delivery. The photons generated by the pyrophosphate sequencing reaction are captured by the CCD only if they pass through a focusing device (e.g., an optical lens or optical fiber) and are focused upon a CCD element. However, the emitted photons will escape equally in all directions. In order to maximize their subsequent “capture” and quantitation when utilizing a planar array (e.g., a DNA chip), it is preferable to collect the photons as close as possible to the point at which they are generated, e.g. immediately at the planar solid support. This is accomplished by either: (i) utilizing optical immersion oil between the cover slip and a traditional optical lens or optical fiber bundle or, preferably, (ii) incorporating optical fibers directly into the cover slip itself. Similarly, when a thin, optically transparent planar surface is used, the optical fiber bundle can also be placed against its back surface, eliminating the need to “image” through the depth of the entire reaction/perfusion chamber. The reaction event, e.g., photons generated by luciferase, may be detected and quantified using a variety of detection apparatuses, e.g., a photomultiplier tube, a CCD, CMOS, absorbance photometer, a luminometer, charge injection device (CID), or other solid state detector, as well as the apparatuses described herein. In a preferred embodiment, the quantitation of the emitted photons is accomplished by the use of a CCD camera fitted with a fused fiber optic bundle. In another preferred embodiment, the quantitation of the emitted photons is accomplished by the use of a CCD camera fitted with a microchannel plate intensifier. A back-thinned CCD can be used to increase sensitivity. CCD detectors are described in, e.g., Bronks, et al., 1995. Anal. Chem. 65: 2750-2757. An exemplary CCD system is a Spectral Instruments, Inc. (Tucson, Ariz.) Series 600 4-port camera with a Lockheed-Martin LM485 CCD chip and a 1-1 fiber optic connector (bundle) with 6-8 μm individual fiber diameters. This system has 4096×4096, or greater than 16 million pixels and has a quantum efficiency ranging from 10% to >40%. Thus, depending on wavelength, as much as 40% of the photons imaged onto the CCD sensor are converted to detectable electrons. In other embodiments, a fluorescent moiety can be used as a label and the detection of a reaction event can be carried out using a confocal scanning microscope to scan the surface of an array with a laser or other techniques such as scanning near-field optical microscopy (SNOM) are available which are capable of smaller optical resolution, thereby allowing the use of “more dense” arrays. For example, using SNOM, individual polynucleotides may be distinguished when separated by a distance of less than 100 nm, e.g., 10 nm×10 nm. Additionally, scanning tunneling microscopy (Binning et al., Helvetica Physica Acta, 55:726-735, 1982) and atomic force microscopy (Hanswa et al., Annu Rev Biophys Biomol Struct, 23:115-139, 1994) can be used. Haplotype Application Virtually any sequencing application can be accomplished using the methods and apparatus of this invention. In one embodiment we contemplate haplotype mapping. Human gene diversity is an important factor in the variability of patient response to pharmaceuticals. The most precise measurement of this diversity is the haplotype, which is the organization of polymorphic variation as it is found on a chromosome. Recently, major government and academic genome researchers in the US, Canada and Europe have agreed that haplotypes are a powerful tool that can reduce the complexity of genetic information to a practical form. Haplotypes can be used in drug discovery to improve the outcome of target validation and drug screening studies and in drug development to improve the design and reliability of clinical trials. Haplotype markers can be used to predict the efficacy and safety of new and approved drugs and will serve as the foundation for a new paradigm of personalized medicine matching patients to the right drug at the right dose via guidance from a database of clinical marker-associations. Numerous empirical studies have shown that nearby SNP alleles are often in linkage disequilibrium (LD) with each other, such that the state of one SNP allele is often highly correlated with the allele of another close SNP. These correlations exist because of the shared history of tightly linked SNP's, which are co-transmitted from generation to generation. Patterns of human sequence variation (haplotypes) thus represent ancestral DNA segments. Historical meioses have slowly dissociated alleles from neighboring alleles on ancestral chromosomes, except for tightly linked variants. The extent of linkage disequilibrium in founder populations with recent bottlenecks had been the object of numerous studies—particularly in the cloning of simple Mendelian disorders disorders such as cystic fibrosis (16), Huntington's disease (11), diastrophic dysplasia (DTD) (8). Whereas these cloning studies benefited from the large chromosomal segments showing LD spanning over large distances (often in the megabase range), very little empirical data was available until recently regarding LD across the human genome in the world population. We focus on three recent examples of large-scale surveys of LD (and haplotypes): (see, e.g, Reich, D. E., Cargill, M., Bolk, S., Ireland, J., Sabeti, P. C., Richter, D. J., Layery, T., Kouyoumjian, R., Farhadian, S. F., Ward, R. & Lander, E. S. 2001. Linkage disequilibrium in the human genome. Nature 411, 199-204.26). We sampled 19 chromosome regions for their SNP content. High frequency SNP's spanning intervals of 2 to 160 kb were first genotyped in a Caucasian samples. Over all regions, LD was detectable at distances of about 60 kb, with a significant difference between regions, as the range was as short as 6 kb at one locus and as long 155 kb in another. Not surprisingly, LD was significantly correlated with the estimated local recombination rates. Further analysis in a Nigerian sample provided evidence of shorter LD in this population—although the allelic combinations over short distances were similar to the Caucasian sample. Overall—this work provided evidence that large blocks of LD are common across the human genome, and that genome-wide LD mapping of disease genes will be feasible. Kits The invention also comprises kits for use in methods of the invention which could include one or more of the following components: (a) a test specific primer which hybridizes to sample DNA so that the target position is directly adjacent to the 3′ end of the primer; (b) a polymerase; (c) detection enzyme means for identifying PPi release; (d) deoxynucleotides including, in place of dATP, a dATP analogue which is capable of acting as a substrate for a polymerase but incapable of acting as a substrate for a said PPi-detection enzyme; and (e) optionally dideoxynucleotides, optionally ddATP being replaced by a ddATP analogue which is capable of acting as a substrate for a polymerase but incapable of acting as a substrate for a said PPi-detection enzyme. If the kit is for use with initial PCR amplification then it could also include the following components: (i) a pair of primers for PCR, at least one primer having means permitting immobilization of said primer; (ii) a polymerase which is preferably heat stable, for example TaqI polymerase; (iii) buffers for the PCR reaction; and (iv) deoxynucleotides. Where an enzyme label is used to evaluate PCR, the kit will advantageously contain a substrate for the enzyme and other components of a detection system. One embodiment of the invention is directed to a method for sequencing nucleic acids. The method involves fragmenting large template nucleic acid molecules to generate a plurality of fragmented nucleic acids. Then the fragmented nucleic acids are delivered into aqueous microreactors in a water-in-oil emulsion such that a plurality of aqueous microreactors comprise a single copy of a fragmented nucleic acid, a single bead capable of binding to the fragmented nucleic acid, and amplification reaction solution containing reagents necessary to perform nucleic acid amplification. In the next step, the fragmented nucleic acids is amplified in the microreactors to form amplified copies of the nucleic acids and binding the amplified copies to beads in the microreactors. Next, the beads are delivered to an array of at least 10,000 reaction chambers on a planar surface, wherein a plurality of the reaction chambers comprise no more than a single bead. Finally, a sequencing reaction is performed simultaneously on a plurality of the reaction chambers. Another embodiment of the invention is directed to an array comprising a planar surface with a plurality of cavities thereon, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and each cavity has a width in at least one dimension of between 20 μm and 70 μm. Further, there are at least 10,000 reaction chambers in the array. Each reaction chambers may contain at least 100,000 copies of a single species of single stranded nucleic acid template. Another embodiment of the invention is directed to an array comprising a planar top surface and a planar bottom surface wherein the planar top surface has at least 10,000 cavities thereon, each cavity forming an analyte reaction chamber, the planar bottom surface is optically conductive such that optical signals from the reaction chambers can be detected through the bottom planar surface, wherein the distance between the top surface and the bottom surface is no greater than 5 mm, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and each chamber having a width in at least one dimension of between 20 μm and 70 μm. The distance between the top surface and the bottom surface, in one embodiment, is no greater than 2 mm. Another embodiment of the invention is directed to an array means for carrying out separate parallel common reactions in an aqueous environment. The array means may comprise a substrate comprising at least 10,000 discrete reaction chambers containing a starting material that is capable of reacting with a reagent, each of the reaction chambers being dimensioned such that when one or more fluids containing at least one reagent is delivered into each reaction chamber, the diffusion time for the reagent to diffuse out of the well exceeds the time required for the starting material to react with the reagent to form a product. Another embodiment of the invention is directed to a method for delivering a bioactive agent to an array. The method comprises dispersing over the array a plurality of mobile solid supports, each mobile solid support having at least one reagent immobilized thereon, wherein the reagent is suitable for use in a nucleic acid sequencing reaction, where the array comprises a planar surface with a plurality of reaction chambers disposed thereon. The the reaction chambers may have a center to center spacing of between 20 to 100 μm and each reaction chamber has a width in at least one dimension of between 20 μm and 70 μm. Another embodiment of the invention is directed to an apparatus for simultaneously monitoring an array of reaction chambers for light indicating that a reaction is taking place at a particular site. The apparatus comprises (a) an array of reaction chambers formed from a planar substrate comprising a plurality of cavitated surfaces, each cavitated surface forming a reaction chamber adapted to contain analytes, and wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, each reaction chamber having a volume of between 10 to 150 pL, the array comprising more than 10,000 discrete reaction chambers; (b) an optically sensitive device arranged so that in use the light from a particular reaction chamber will impinge upon a particular predetermined region of the optically sensitive device; (c) means for determining the light level impinging upon each of the predetermined regions; and (d) means to record the variation of the light level with time for each of the reaction chamber. Another embodiment of the invention is directed to an analytic sensor, comprising (a) an array formed from a first bundle of optical fibers with a plurality of cavitated surfaces at one end thereof, each cavitated surface forming a reaction chamber adapted to contain analytes, and wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, a width of 20 to 70 μm, the array comprising more than 10,000 discrete reaction chambers; (b) an enzymatic or fluorescent means for generating light in the reaction chambers; and (c) light detection means comprising a light capture means and a second fiber optic bundle for transmitting light to the light detecting means, the second fiber optic bundle being in optical contact with the array, such that light generated in an individual reaction chamber is captured by a separate fiber or groups of separate fibers of the second fiber optic bundle for transmission to the light capture means. Another embodiment of the invention is directed to a method for carrying out separate parallel common reactions in an aqueous environment. The first step involves delivering a fluid containing at least one reagent to an array, wherein the array comprises a substrate comprising at least 10,000 discrete reaction chambers, each reaction chamber adapted to contain analytes, and wherein the reaction chambers have a volume of between 10 to 150 pL and containing a starting material that is capable of reacting with the reagent, each of the reaction chambers being dimensioned such that when the fluid is delivered into each reaction chamber, the diffusion time for the reagent to diffuse out of the well exceeds the time required for the starting material to react with the reagent to form a product. The second step involves washing the fluid from the array in the time period (i) after the starting material has reacted with the reagent to form a product in each reaction chamber but (ii) before the reagent delivered to any one reaction chamber has diffused out of that reaction chamber into any other reaction chamber. Another embodiment of the invention is directed to a method for delivering nucleic acid sequencing enzymes to an array. The array having a planar surface with a plurality of cavities thereon, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm. The method involves the step of dispersing over the array a plurality of mobile solid supports having one or more nucleic acid sequencing enzymes immobilized thereon, such that a plurality of the reaction chambers contain at least one mobile solid support. Another embodiment of the invention is directed to a method for delivering a plurality of nucleic acid templates to an array. The array may have a planar surface with a plurality of cavities thereon, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and the array having at least 10,000 reaction chambers. The method comprise the step of dispersing over the array a plurality of mobile solid supports, each mobile solid support having no more than a single species of nucleic acid template immobilized thereon, the dispersion causing no more than one mobile solid support to be disposed within any one reaction chamber. Another embodiment of the invention is directed to a method for sequencing a nucleic acid. The method comprises the step of providing a plurality of single-stranded nucleic acid templates disposed within a plurality of cavities on a planar surface, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and the planar surface has at least 10,000 reaction chambers. The next step involves performing a pyrophosphate based sequencing reaction simultaneously on all reaction chambers by annealing an effective amount of a sequencing primer to the nucleic acid templates and extending the sequencing primer with a polymerase and a predetermined nucleotide triphosphate to yield a sequencing product and, if the predetermined nucleotide triphosphate is incorporated onto the 3′ end of the sequencing primer, a sequencing reaction byproduct. The third step involves identifying the sequencing reaction byproduct, thereby determining the sequence of the nucleic acid in each reaction chamber. Another embodiment of the invention is directed to a method of determining the base sequence of a plurality of nucleotides on an array. The first step involves providing at least 10,000 DNA templates, each separately disposed within a plurality of cavities on a planar surface, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, and a volume of between 10 to 150 pL. The second step involves adding an activated nucleotide 5′-triphosphate precursor of one known nitrogenous base to a reaction mixture in each reaction chamber, each reaction mixture comprising a template-directed nucleotide polymerase and a single-stranded polynucleotide template hybridized to a complementary oligonucleotide primer strand at least one nucleotide residue shorter than the templates to form at least one unpaired nucleotide residue in each template at the 3′-end of the primer strand, under reaction conditions which allow incorporation of the activated nucleoside 5′-triphosphate precursor onto the 3′-end of the primer strands, provided the nitrogenous base of the activated nucleoside 5′-triphosphate precursor is complementary to the nitrogenous base of the unpaired nucleotide residue of the templates. The third step involves detecting whether or not the nucleoside 5′-triphosphate precursor was incorporated into the primer strands in which incorporation of the nucleoside 5′-triphosphate precursor indicates that the unpaired nucleotide residue of the template has a nitrogenous base composition that is complementary to that of the incorporated nucleoside 5′-triphosphate precursor. The fourth step involves sequentially repeating steps (b) and (c), wherein each sequential repetition adds and, detects the incorporation of one type of activated nucleoside 5′-triphosphate precursor of known nitrogenous base composition. The fifth step involves determining the base sequence of the unpaired nucleotide residues of the template in each reaction chamber from the sequence of incorporation of the nucleoside precursors. Another embodiment of the invention is directed to a method of identifying the base in a target position in a DNA sequence of template DNA. The first step involves providing at least 10,000 separate DNA templates are separately disposed within a plurality of cavities on a planar surface, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, the DNA being rendered single stranded either before or after being disposed in the reaction chambers. The second step involves providing an extension primer is provided which hybridizes to the immobilized single-stranded DNA at a position immediately adjacent to the target position. The immobilized single-stranded DNA is subjected to a polymerase reaction in the presence of a predetermined deoxynucleotide or dideoxynucleotide, wherein if the predetermined deoxynucleotide or dideoxynucleotide is incorporated onto the 3′ end of the sequencing primer then a sequencing reaction byproduct is formed. The fourth step involves identifying the sequencing reaction byproduct, thereby determining the nucleotide complementary to the base at the target position in each of the 10,000 DNA templates. Another embodiment of the invention is directed to an apparatus for analyzing a nucleic acid sequence. The apparatus comprises: (a) a reagent delivery cuvette, wherein the cuvette includes an array comprising a planar surface with a plurality of cavities thereon, each cavity forming an analyte reaction chamber, wherein the reaction chambers have a center to center spacing of between 20 to 100 μm, and there are in excess of 10,000 reaction chambers, and wherein the reagent delivery cuvette contains reagents for use in a sequencing reaction; (b) a reagent delivery means in communication with the reagent delivery cuvette; (c) an imaging system in communication with the reagent delivery chamber; and (d) a data collection system in communication with the imaging system. Another embodiment of the invention is directed to an apparatus for determining the base sequence of a plurality of nucleotides on an array. The apparatus comprises: (a) a reagent cuvette containing a plurality of cavities on a planar surface, each cavity forming an analyte reaction chamber, wherein there are in excess of 10,000 reaction chambers, each having a center to center spacing of between 20 to 100 μm and a volume of between 10 to 150 pL; (b) reagent delivery means for simultaneously adding to each reaction chamber an activated nucleotide 5′-triphosphate precursor of one known nitrogenous base to a reaction mixture in each reaction chamber, each reaction mixture comprising a template-directed nucleotide polymerase and a single-stranded polynucleotide template hybridized to a complementary oligonucleotide primer strand at least one nucleotide residue shorter than the templates to form at least one unpaired nucleotide residue in each template at the 3′-end of the primer strand, under reaction conditions which allow incorporation of the activated nucleoside 5′-triphosphate precursor onto the 3′-end of the primer strands, provided the nitrogenous base of the activated nucleoside 5′-triphosphate precursor is complementary to the nitrogenous base of the unpaired nucleotide residue of the templates; (c) detection means for detecting in each reaction chamber whether or not the nucleoside 5′-triphosphate precursor was incorporated into the primer strands in which incorporation of the nucleoside 5′-triphosphate precursor indicates that the unpaired nucleotide residue of the template has a nitrogenous base composition that is complementary to that of the incorporated nucleoside 5′-triphosphate precursor; and (d) means for sequentially repeating (b) and (c), wherein each sequential repetition adds and, detects the incorporation of one type of activated nucleoside 5′-triphosphate precursor of known nitrogenous base composition; and (e) data processing means for determining the base sequence of the unpaired nucleotide residues of the template simultaneously in each reaction chamber from the sequence of incorporation of the nucleoside precursors. Another embodiment of the invention is directed to an apparatus for processing a plurality of analytes. The apparatus comprises: (a) a flow chamber having disposed therein a substrate comprising at least 50,000 cavitated surfaces on a fiber optic bundle, each cavitated surface forming a reaction chamber adapted to contain analytes, and wherein the reaction chambers have a center to center spacing of between 20 to 100 μm and a diameter of 20 to 70 μm; (b) fluid means for delivering processing reagents from one or more reservoirs to the flow chamber so that the analytes disposed in the reaction chambers are exposed to the reagents; and (c) detection means for simultaneously detecting a sequence of optical signals from each of the reaction chambers, each optical signal of the sequence being indicative of an interaction between a processing reagent and the analyte disposed in the reaction chamber, wherein the detection means is in communication with the cavitated surfaces. Another embodiment of the invention is directed to a method for sequencing a nucleic acid. The first step involves providing a plurality of single-stranded nucleic acid templates in an array having at least 50,000 discrete reaction sites. The second step involves contacting the nucleic acid templates with reagents necessary to perform a pyrophosphate-based sequencing reaction coupled to light emission. The third step involves detecting the light emitted from a plurality of reaction sites on respective portions of an optically sensitive device. The forth step involves converting the light impinging upon each of the portions of the optically sensitive device into an electrical signal which is distinguishable from the signals from all of the other reaction sites. The fifth step involves determining the sequence of the nucleic acid templates based on light emission for each of the discrete reaction sites from the corresponding electrical signal. Another embodiment of the invention is directed to a method for sequencing nucleic acids. The first step involves fragmenting large template nucleic acid molecules to generate a plurality of fragmented nucleic acids. The second step involves attaching one strand of a plurality of the fragmented nucleic acids individually to beads to generate single stranded nucleic acids attached individually to beads. The third step involves delivering a population of the single stranded fragmented nucleic acids attached individually to beads to an array of at least 10,000 reaction chambers on a planar surface, wherein a plurality of the wells comprise no more than a one bead with on single stranded fragmented nucleic acid. The fourth step involves performing a sequencing reaction simultaneously on a plurality of the reaction chambers. The sequencing reaction may have the steps of (a) annealing an effective amount of a sequencing primer to the single stranded fragmented nucleic acid templates and extending the sequencing primer with a polymerase and a predetermined nucleotide triphosphate to yield a sequencing product and, if the predetermined nucleotide triphosphate is incorporated onto the 3′ end of the sequencing primer, a sequencing reaction byproduct; and (b) identifying the sequencing reaction byproduct, thereby determining the sequence of the nucleic acid in a plurality of the reaction chambers. Alternatively, the sequencing reaction may comprises the steps of: (a) hybridizing two or more sequencing primers to one or a plurality of single strands of the nucleic acid molecule wherein all the primers except for one are reversibly blocked primers; (b) incorporating at least one base onto the nucleic acid molecule by polymerase elongation from an unblocked primer; (c) preventing further elongation of the unblocked primer; (d) deblocking one of the reversibly blocked primers into an unblocked primer; and (e) repeating steps (b) to (d) until at least one of the reversibly blocked primers are deblocked and used for determining a sequence. Other materials and methods may be found in the following copending U.S. patent applications: U.S. Ser. No. 60/443,471 filed Jan. 29, 2003 and U.S. Ser. No. 60/465,071 filed Apr. 23, 2003. All patents, patent applications, and references cited in this disclosure are incorporated herein by reference. EXAMPLES Example 1 Sample Preparation DNA Sample: The DNA should be of high quality and free from contaminants such as proteins, nucleases, lipids, and other chemicals (such as residual EDTA from preparation) and salts. It is preferred that genomic DNA should have a 260/280 ratio of 1.8 or higher. If it is desired to sequence the genome of only one organism, then the DNA should be quality checked to ensure that there is no contaminating DNA. For example: a preparation of human DNA may be checked by PCR to ensure that it is not contaminated by bacterial DNA molecules. Another method of checking for contamination is by restriction digestion patterns and especially restriction digestion followed by Southern Blot using suitable probes known to be specific for an organism (e.g., human or mouse) and a second probe known to be specific for a possible contaminating organism (e.g., E. coli). If it is desired, the DNA should originate from a single clone of the organism (e.g., a colony if from bacteria). Step 1: DNase I Digestion The purpose of the DNase I digestion step is to fragment a large stretch of DNA such as a whole genome or a large portion of a genome into smaller species. This population of smaller-sized DNA species generated from a single DNA template is referred to as a “library”. Deoxyribonuclease I (DNase I) is an endonuclease which cleaves double-stranded template DNA. The cleavage characteristics of DNase I allow random digestion of template DNA (i.e., minimal sequence bias) and will result in the predominance of blunt-ended, double-stranded DNA fragments when used in the presence of manganese-based buffers (Melgar and Goldthwait 1968). The digestion of genomic templates by DNase I is dependent on three factors: i) quantity of enzyme used (units); ii) temperature of digestion (° C.); and iii) incubation time (minutes). The DNase I digestion conditions outlined below were optimized to yield DNA libraries in a size range from 50-700 base pairs (bp). 1. DNA was obtained and prepared to a concentration of 0.3 mg/ml in Tris-HCl (10 mM, pH 7-8). A total of 134 μl of DNA (15 μg) was needed for this preparation. It is recommended to not use DNA preparations diluted with buffers containing EDTA (i.e., TE, Tris/EDTA). The presence of EDTA is inhibitory to enzyme digestion with DNase I. If the DNA preparation contains EDTA, it is important that the DNA be “salted” out of solution and reconstituted with the appropriate Tris-HCl buffer (10 mM, pH 7-8) or nanopure H2O (pH 7-8). 2. In a 0.2 ml tube, DNase I Buffer, comprising 50 μl Tris pH 7.5 (1M), 10 μl MnCl2 (IM), 1 μl BSA (100 mg/ml), and 39 μl water was prepared. 3. In a separate 0.2 ml tube, 15 μl of DNase I Buffer and 1.5 μl of DNase I (IU/ml) was added. The reaction tube was placed in a thermal cycler set to 15° C. 4. The 134 μl of DNA (0.3 mg/ml) was added to the DNase I reaction tube placed in the thermal cycler set at 15° C. The lid was closed and the sample was incubated for exactly 1 minute. Following incubation, 50 μl of 50 mM EDTA was added to stop the enzyme digestion. 5. The digested DNA was purified by using the QiaQuick PCR purification kit. The digestion reaction was then split into four aliquots, and four spin columns were used to purify each aliquot (37.5 μl per spin column). Each column was eluted with 30 μl elution buffer (EB) according to the manufacturer's protocol. The eluates were then combined to generate a final reaction volume of 120 μl. 6. One 3 μl aliquot of the digestion reaction was saved for analysis using a BioAnalzyer DNA 1000 LabChip. Step 2: Pfu Polishing Digestion of DNA templates with DNase I yields fragments of DNA that are primarily blunt-ended, however, some fragments will have ends that contain protruding termini that are one or two nucleotides in length. Pfu polishing is used to increase the amount of blunt-ended species by fill-in (i.e., “blunting”) of 5′ overhangs. Additionally, Pfu DNA polymerase has 3′-5′ exonuclease activity that will result in the removal of single and double nucleotide extensions. Pfu polishing increases the amount of blunt-ended DNA fragments available for adaptor ligation (Costa 1994a, 1994b, 1994c). The following Pfu polishing protocol was used. 1. In a 0.2 ml tube, 115 μl purified, DNase I-digested DNA fragments, 15 μL 10× Cloned Pfu buffer, 5 μl dNTPs (10 mM), and 15 μl cloned Pfu DNA polymerase (2.5 U/μl) were added in order. 2. The polishing reaction components were mixed well and incubated at 72° C for 30 minutes. 3. Following incubation, the reaction tube was removed and placed on ice for 2 minutes. 4. The polishing reaction mixture was then split into four aliquots and purified using QiaQuick PCR purification columns (37.5 μL on each column). Each column was eluted with 30 μl buffer EB according to the manufacturer's protocol. The eluates were then combined to generate a final reaction volume of 120 μL. 5. One 3 μl aliquot of the final polishing reaction was saved for analysis using a BioAnalzyer DNA 1000 LabChip. Step 3: Ligation of Universal Adaptors to Fragmented DNA Library Following fragmentation and polishing of the genomic DNA library, primer sequences are added to the ends of each DNA fragment. These primer sequences are termed “Universal Adaptors” and are comprised of double-stranded oligonucleotides that contain specific priming regions that afford both PCR amplification and nucleotide sequencing. The Universal Adaptors are designed to include a set of unique PCR priming regions that are 20 base pairs in length located adjacent to a set of unique sequencing priming regions that are 20 base pairs in length, followed by a unique 4-base “key” consisting of one of each deoxyribonucleotide (i.e., A, C, G, T). Each unique Universal Adaptor (termed “Universal Adaptor A” and “Universal Adaptor B”) is forty-four base pairs (44 bp) in length. Universal Adaptors are ligated, using T4 DNA ligase, onto each end of the DNA fragment to generate a total nucleotide addition of 88 bp to each DNA fragment. Different Universal Adaptors are designed specifically for each genomic DNA library preparation and will therefore provide a unique identifier for each organism. To prepare a pair of Universal Adaptors, single-stranded oligonucleotides are designed in-house and are manufactured through a commercial vendor. Universal Adaptor DNA oligonucleotides are designed with two phosphorothioate linkages at each oligonucleotide end that serve to protect against nuclease activity (Samini, T. D., B. Jolles, and A. Laigle. 2001. Best minimally modified antisense oligonucleotides according to cell nuclease activity. Antisense Nucleic Acid Drug Dev. 11(3):129., the disclosure of which is incorporated in toto herein by reference.). Each oligonucleotide is HPLC-purified to ensure there are no contaminating or spurious DNA oligonucleotide sequences in the final prep. The Universal Adaptors are designed to allow directional ligation to the blunt-ended, fragmented genomic DNA. For each Universal Adaptor pair, the PCR priming region contains a 5′ four-base overhang and a blunt-ended 3′ Key region. Directionality is achieved as the blunt-end side of the Universal Adaptor ligates to the blunt-ended DNA fragment while the 5′ overhang of the adaptor cannot ligate to the blunt-ended DNA fragment. Additionally, a 5′ biotin is added to the Universal Adaptor B to allow subsequent isolation of ssDNA template (Step 8). Each Universal Adaptor is prepared by annealing, in a single tube, the two single-stranded complementary DNA oligonucleotides (i.e., one oligo containing the sense sequence and the second oligo containing the antisense sequence). The following ligation protocol was used. 1. In a 0.2 ml tube, 39 μl nH2O (molecular biology grade water), 25 μl digested, polished DNA Library, 100 μl 2×Quick Ligase Reaction Buffer, 20 μl MMP1 (10 pm/μl) adaptor set, 100:1 ratio, and 16 μl Quick Ligase were added in order. The ligation reaction was mixed well and incubated at RT for 20 minutes. 2. The ligation reaction was then removed and a 10-μl aliquot of the ligation reaction was purified for use on the BioAnalyzer. A single spin column from the Qiagen Min-Elute kit was used. The column was eluted with 10 μl EB according to the procedure per manufacturers' protocol. A 1-μl aliquot of the purified ligation reaction was loaded using a BioAnalyzer DNA 1000 LabChip. This purification step is recommended as the unpurified ligation reaction contains high amounts of salt and PEG that will inhibit the sample from running properly on the BioAnalyzer. 3. The remainder of the ligation reaction (190 μL) was used for gel isolation in Step 4. Step 3a: Microcon Filtration and Adaptor Construction. Total Preparation Time was Approximately 25 Min. The Universal Adaptor ligation reaction requires a 100-fold excess of adaptors. To aid in the removal of these excess adaptors, the double-stranded gDNA library is filtered through a Microcon YM-100 filter device. Microcon YM-100 membranes can be used to remove double stranded DNA smaller than 125 bp. Therefore, unbound adaptors (44 bp), as well as adaptor dimers (88 bp) can be removed from the ligated gDNA library population. The following filtration protocol was used: 1. The 190 μL of the ligation reaction from Step 4 was applied into an assembled Microcon YM-100 device. 2. The device was placed in a centrifuge and spun at 5000×g for approximately 6 minutes, or until membrane was almost dry. 3. To wash, 200 μl of 1×TE was added. 4. Sample was spun at 5000×g for an additional 9 minutes, or until membrane was almost dry. 5. To recover, the reservoir was inserted into a new vial and spun at 3000×g for 3 minutes. The reservoir was discarded. The recovered volume was approximately 10 μl. Next, 80 μl TE was added. The Adaptors (A and B) were HPLC-purified and modified with phosphorothioate linkages prior to use. For Adaptor “A” (10 μM), 10 μl of 100 μM Adaptor A (44 bp, sense) was mixed with 10 μl of 100 μM Adaptor A (40 bp, antisense), and 30 μl of 1× Annealing Buffer (Vf=50 μl) were mixed. The primers were annealed using the ANNEAL program on the Sample Prep Labthermal cycler (see below). For Adaptor “B” (10 μM), 10 μl of 100 μM Adaptor B (40 bp, sense) was mixed with 10 μl of 100 μM Adaptor B (44 bp, antisense), and 30 μl of 1× Annealing Buffer (Vf=50 μl). The primers were annealed using the ANNEAL program on the Sample Prep Lab thermal cycler. Adaptor sets could be stored at −20° C. until use. ANNEAL-A program for primer annealing: 1. Incubate at 95° C., 1 min; 2. Decrease temperature to 15° C., at 0.1° C./sec; and 3. Hold at 15° C. There was no orientation required for the genomic DNA insert fragment and the adaptors. Fragments could be ligated at either end. Four single-stranded DNA oligonucleotides were included in the Universal Adaptor set. Each single-stranded oligonucleotide was synthesized at 1 micromole scale and HPLC-purified. Each single-stranded oligonucleotide included four phosphorothioate linkages at each end. Step 4: Gel Electrophoresis and Extraction of Adapted DNA Library The Universal Adaptor ligation protocol produces the following: 1) fragmented DNAs with adaptors on either end; 2) unbound single adaptors; or 3) the formation of adaptor dimers. Agarose gel electrophoresis is used as a method to separate and isolate the adapted DNA library population from the unligated, single adaptors and adaptor dimer populations. The procedure of DNase I digestion of genomic DNA yields a library population that ranges from 50-700 bp (Step 1). The addition of the 88-bp Universal Adaptor set will shift the population to a larger size and will result in a migration profile in the size range of approximately 130-800 bp. Adaptor dimers will migrate at 88 bp and adaptors unligated will migrate at 44 bp. Therefore, genomic DNA libraries in size ranges>200 bp can be physically isolated from the agarose gel and purified using standard gel extraction techniques. Gel isolation of the adapted DNA library will result in the recovery of a library population in a size range that is >200 bp (size range of library can be varied depending on application). The following electrophoresis and extraction protocol was used. 1. A 2% agarose gel was prepared. 2. 10 μl of 10×Ready-Load Dye was added to the remaining 90 μL of the DNA ligation mixture. 3. The dye/ligation reaction mixture was loaded into the gel using four adjacent lanes (25 μl per lane). 4. 10 μl of the 100 bp ladder (0.1 μg/μl) was loaded two lanes away from ligation reaction lanes. 5. The gel was run at 100V for 3 hours. 6. When the gel run was complete, the gel was removed from the gel box and transferred to a flat surface covered with plastic wrap. DNA bands were visualized using a hand-held long-wave UV light. Using a sterile, single-use scalpel, the fragment sizes of 200-400 bp were cut out from the agarose gel. Using this approach, libraries with any size range can be isolated. It is also possible to isolate more than one size range. Where the library size range is 200-900 bp, it is possible to isolate several size ranges from a single well (i.e., 200-400 bp and 500-700 bp). 7. The DNA embedded in the agarose gel was isolated using a Qiagen MinElute Gel Extraction kit following the manufacturer's instructions. Briefly, Buffer QG was added to cover the agarose in the tube. The agarose was allowed to completely dissolve. The color of the Buffer QG was maintained by adjusting the pH according to the Qiagen instructions to minimize sample loss. Two MinElute spin columns (Qiagen) were used for purification. The large volume of dissolved agarose required each column to be loaded several times. The columns were eluded with 10 μl of Buffer EB which was pre-warmed at 55° C. The eluates were pooled to produce 20 μl of gDNA library. 8. One 1 μL aliquot of each isolated DNA library was analyzed using a BioAnalyzer DNA 1000 LabChip to assess the exact distribution of the DNA library population. Step 5: Strand Displacement and Extension of Nicked Double Stranded DNA Library Because the DNA oligonucleotides used for the Universal Adaptors are not phosphorylated, gaps are present at the 3′ junctions of the fragmented gDNAs. These two “gaps” or “nicks” can be filled in by using a strand displacing DNA polymerase. The polymerase recognizes nicks, displaces the nicked strands, and extends the strand in a manner that results in repair of nicks and in the formation of non-nicked double-stranded DNA. The strand displacing enzyme used is the large fragment of Bst DNA polymerase. 1. In a 0.2 ml tube, 19 μl gel-extracted DNA library, 40 μl nH2O, 8 μl 10× ThermoPol Reaction Buffer, 8 μl BSA (1 mg/ml), 2 μl dNTPs (10 mM), and 3 μl Bst I Polymerase (8 U/μl) were added in order. 2. The samples were mixed well and placed in a thermal cycler and incubated using the Strand Displacement incubation program: “BST”. BST program for stand displacement and extension of nicked double-stranded DNA: 1. Incubate at 65° C., 30 minutes; 2. Incubate at 80° C., 10 minutes; 3. Incubate at 58° C., 10 minutes; and 4. Hold at 14° C. 3. One 1 μL aliquot of the Bst-treated DNA library was run using a BioAnalyzer DNA 1000 LabChip. Step 6: Preparation of Streptavidin Beads Following the generation of unnicked double-stranded genomic DNA, it is necessary to isolate single-stranded genomic DNAs containing flanking Universal Adaptor sequences. This step outlines the binding of biotin-tagged double-stranded DNA to streptavidin beads. For preparing streptavidin beads, the following protocol was used. 1. 100 μl Dynal M-270 Streptavidin beads were washed two times with 200 μl of 1× Binding Buffer (1 M NaCl, 0.5 mM EDTA, 5 mM Tris, pH 7.5) by applying the magnetic beads to the MPC. 2. The beads were resuspended in 100 μl 2× Binding buffer, then the remaining 79 μl of the Bst-treated DNA sample (from Step 5) and 20 μl water was added. 3. The bead solution was mixed well and placed on a tube rotator at RT for 20 minutes. The bead mixtures were washed, using the MPC, two times with 100 μl of 1× Binding Buffer, then washed two times with nH2O. Binding & Washing (B&W) Buffer (2× and 1×): 2×B&W buffer was prepared by mixing 10 mM Tris.HCl (pH 7.5), 1 mM EDTA, and 2 M NaCl. The reagents were combined as listed above and mixed thoroughly. The solution can be stored at RT for 6 months; 1×B&W buffer was prepared by mixing 2×B&W buffer with nH2O, 1:1. The final concentrations were half the above, i.e., 5 mM Tris.HCl (pH 7.5), 0.5 mM EDTA, and 1 M NaCl. Step 7: Isolation of Single-Stranded DNA Library Using Streptavidin Beads Following binding of the double-stranded gDNA library to streptavidin beads, it is preferred to isolate from the ligated pool only the single-stranded gDNAs containing Universal Adaptor A and Universal Adaptor B (desired populations are designated below with asterisks). Double-stranded genomic DNA fragment pools will have adaptors bound in the following possible configurations: Universal Adaptor A-gDNA Fragment-Universal Adaptor A Universal Adaptor B-gDNA Fragment-Universal Adaptor A* Universal Adaptor A-gDNA Fragment-Universal Adaptor B* Universal Adaptor B-gDNA Fragment-Universal Adaptor B Because only the Universal Adaptor B has a 5′ biotin moiety, magnetic streptavidin-containing beads can be used to bind all gDNA library species that possess the Universal Adaptor B. Genomic library populations that contain two Universal Adaptor A species (or nonligated species) do not bind to streptavidin-containing beads and are removed during the wash procedure. The species that remain bound to bead after washing include those with Universal Adaptors A and B or those with two Universal Adaptor B ends. Genomic DNA species with two Universal Adaptor B sequences with two biotin molecules can bind to the streptavidin-containing beads at both ends. Species with A and B adaptors having only a single biotin molecule can bind to the beads only at the “B” end. To isolate the single-stranded population, the bead-bound double-stranded DNA is treated with a sodium hydroxide solution that serves to disrupt the hydrogen bonding between the complementary DNA strands. If the DNA fragment has biotin on each end (Universal Adaptor B ends), both resulting single strands remain bound to the beads. If the fragment has only a single biotin (Universal Adaptors A and B), then the complementary strand separates from the DNA-bead complex. The resulting single-stranded genomic DNA library is collected from the solution phase and is quantitated, e.g., using pyrophosphate sequencing (PyroSequence) or by using a RNA Pico 6000 LabChip (Agilent, Palo Alto, Calif.). Single-stranded genomic DNA libraries are quantitated by calculating the number of molecules per unit volume. Single-stranded gDNA molecules are then annealed (at a half copy per bead to obtain one effective copy per bead) to 25-30 μm sepharose beads containing DNA capture primers (PCR primer B). The templates are then amplified using emulsion polymerase chain reaction protocols. Subsequent sequencing may be conducted using known techniques. For isolation of the single stranded library, the following protocol was used. 1. 250 μl Melt Solution (0.125 M NaOH, 0.1 M NaCl)was added to washed beads from Step 6 above. 2. The bead solution was mixed well and the bead mixture was incubated at room temperature for 10 minutes on a tube rotator. 3. A Dynal MPC (magnetic particle concentrator) was used, the pellet beads were carefully removed, and the supernatant was set aside. The 250-μl supernatant included the single-stranded DNA library. 4. In a separate tube, 1250 μl PB (from QiaQuick Purification kit) was added and the solution was neutralized by adding 9 μl of 20% acetic acid. 5. Using a Dynal MPC, beads from the 250-μl supernatant including the single-stranded gDNA library were pelleted and the supernatant was carefully removed and transferred to the freshly prepared PB/acetic acid solution. 6. The 1500 μl solution was purified using a single QiaQuick purification spin column (load sample through same column two times at 750 μl per load). The single-stranded DNA library was eluted with 50 μl EB. Step 8a: Single-Stranded gDNA Quantitation Using Pyrophosphate Sequencing. Total Preparation Time was Approximately 1 hr. 1. In a 0.2 ml tube, the following reagents were added in order: 25 μl single-stranded gDNA 1 μl MMP2B sequencing primer 14 μl Library Annealing Buffer 40 μl total 2. The DNA was allowed to anneal using the ANNEAL-S Program (see Appendix, below). 3. The samples were run on PSQ (pyrophosphate sequencing jig) to determine the number of picomoles of template in each sample (see below). Methods of sequencing can be found in U.S. Pat. No. 6,274,320; U.S. Pat. No. 4,863,849; U.S. Pat. No. 6,210,891; and U.S. Pat. No. 6,258,568, the disclosures of which are incorporated in toto herein by reference. Calculations were performed to determine the number of single-stranded gDNA template molecules per microliter. The remaining 25 μL of prepared single-stranded gDNA library was used for amplification and subsequent sequencing (approximately 1×106 reactions). Step 8b: Single-Stranded gDNA Quantitation Using RNA Pico 6000 LabChip. Total Preparation Time was Approximately 30 Minutes. 1. The mRNA Pico-assay option was selected on the BioAnalyzer (Software version 2.12). 2. An RNA Pico 6000 LabChip was prepared on the BioAnalyzer according to the manufacturers' guidelines. 3. An RNA LabChip ladder (RNA 6000 ladder) was prepared according to manufacturer's (Ambion) directions. Briefly, the RNA LabChip ladder, in solution, was heated to 70° C. for 2 minutes. The solution was chilled on ice for 5 minutes to snap cool the ladder. The solution was briefly centrifuged to clear any condensate from tube walls. The RNA LabChip Ladder was stored on ice and used within one day. 4. The ssDNA library to be analyzed was run in triplicate, in adjacent lanes, using three 1 μl aliquots. 5. The BioAnalyzer software was used to calculate the concentration of each ssDNA library lane (see the Table below and FIG. 24. The average of all three lanes was used to calculate the DNA concentration of the library using the procedure outlined below. a. The peak integration lower limit line (large dash in FIG. 24) was moved immediately in front of the library peak (see below). b. The peak integration upper limit line (large dash in the FIG. 24) was moved immediately after the library peak. In this way, the peak integration line connecting the lower and upper integration lines followed the slope of the background. c. The mouse arrow was used to determine the average size of the peak in bases (usually near the peaks highest point) or a defined peak was used as chosen by the software. d. The integrated value was used for the amount of material in the peak. The value obtained for picograms recovered was converted into molecules recovered (see Table, below). The library concentration was then determined (molecules per microliter). TABLE 5 6 7 8 9 2 3 4 Average Mean Mean Mean Average 1 pg/μL (1) pg/μL (2) pg/μL (3) pg/μL Size (bp) 1 Size (bp) 2 Size (bp) 3 Size (bp) sample 1633 1639 1645 1639 435 435 432 434 10 11 12 Ave MW (g/mole) Ave MW Library 13 14 15 Ribonucleotide (g/mole) g/μL moles/g moles/μL molecules/μL 328.2 1.42E+05 1.64E−09 7.02E−06 1.15E−14 6.93E+09 As shown in the Table above, the concentration of Library 1 was calculated as 1639 pg/μl (Column 5) and the average fragment size was 434 nucleotides (Column 9). These values were obtained from the Agilent 2100 software as described in Steps (a)-(d), above. The average molecular weight (MW) of a ribonucleotide is 328.2 g/mole (Column 10). The MW of the average library fragment (1.42×105 g/mole, Column 11) was calculated by multiplying the average fragment length (434) by the average ribonucleotide (328.2). The quantitated library (1639 pg/μl) was converted to grams per microliter (1.64×10−9 g/μl, Column 12). The number of moles per microliter (1.15×10−14 moles/μl, Column 14) was calculated by dividing the grams per microliter (1.64×10−9 g/μl, Column 12) by the average molecular weight of the library fragments (1.42×105, Column 11). Finally, the number of molecules per microliter (6.93×109 molecules/μl, Column 15) was derived by multiplying the number of moles per microliter (1.15×10−14 moles/el, Column 14) by Avogadro's number (6.02×1023 molecules/mole). The final library concentration was expected to be greater than 1×108 molecules/μl. A more important factor for library quality was adaptor dimer concentration. In FIG. 24, the height of the library peak was determined approximately 10 fold greater than the adaptor dimer peak (the first peak after the marker). A library of good quality is expected to have a peak height at least 2 fold greater than the dimer peak. It should be noted that the RNA Pico 6000 LabChip provided estimates within 500% accuracy of the single-stranded gDNA concentration. Thus, it was important to perform an initial sequencing run using a titration of template to determine the number of copies per bead (cpb) of input gDNA. The recommended input DNA is 2.5 cpb, 1 cpb, 0.5 cpb, and 0.1 cpb. This titration was easily checked using the 4slot bead loading chamber on a 14×43 PTP. Step 9: Dilution and Storage of Single-Stranded gDNA Library The single-stranded gDNA library was eluted and quantitated in Buffer EB. To prevent degradation, the single-stranded gDNA library was stored frozen at −20° C. in the presence of EDTA. After quantitation, an equal volume of 10 mM TE was added to the library stock. All subsequent dilutions was in TE. The yield was as follows: Remaining final volume of ssDNA library following PSQ analysis=25 μl. Remaining final volume of ssDNA library following LabChip analysis=47 μl. For the initial stock dilution, single-stranded gDNA library was diluted to 100 million molecules/μl in 1× Library-Grade Elution Buffer. Aliquots of single-stranded gDNA library were prepared for common use. For this, 200,000 molecules/μl were diluted in 1× Library-Grade Elution Buffer and 20 μl aliquots were measured. Single-use library aliquots were stored at −20° C. Step 10: Emulsion Polymerase Chain Reaction Where increased numbers of cpb were preferred, bead emulsion PCR was performed as described in U.S. Patent Application Serial No. 06/476,504 filed Jun. 6, 2003, incorporated herein by reference in its entirety. Reagent Preparation The Stop Solution (50 mM EDTA) included 100 μl of 0.5 M EDTA mixed with 900 μl of nH2O to obtain 1.0 ml of 50 mM EDTA solution. For 10 mM dNTPs, (10 μl dCTP (100 mM), 10 μl dATP (100 mM), 10 PI dGTP (100 mM), and 10 PI dTTP (100 mM) were mixed with 60 μl molecular biology grade water. All four 100 mM nucleotide stocks were thawed on ice. Then, 10 μl of each nucleotide was combined with 60 PI of nH2O to a final volume of 100 μl, and mixed thoroughly. Next, 1 ml aliquots were dispensed into 1.5 ml microcentrifuge tubes. The stock solutions could be stored at −20° C. for one year. The 10× Annealing buffer included 200 mM Tris (pH 7.5) and 50 mM magnesium acetate. For this solution, 24.23 g Tris was added to 800 ml nH2O and the mixture was adjusted to pH 7.5. To this solution, 10.72 g of magnesium acetate was added and dissolved completely. The solution was brought up to a final volume of 1000 ml and could be stored at 4° C. for 1 month. The 10×TE included 100 mM Tris-HCl (pH 7.5) and 50 mM EDTA. These reagents were added together and mixed thoroughly. The solution could be stored at room temperature for 6 months. Example 2 Primer Design As discussed above, the universal adaptors are designed to include: 1) a set of unique PCR priming regions that are typically 20 bp in length (located adjacent to (2)); 2) a set of unique sequencing priming regions that are typically 20 bp in length; and 3) optionally followed by a unique discriminating key sequence consisting of at least one of each of the four deoxyribonucleotides (i.e., A, C, G, T). The probability of cross-hybridization between primers and unintended regions of the genome of interest is increased as the genome size increases and length of a perfect match with the primer decreases. However, this potential interaction with a cross-hybridizing region (CHR) is not expected to produce problems for the reasons set forth below. In a preferred embodiment of the present invention, the single-stranded DNA library is utilized for PCR amplification and subsequent sequencing. Sequencing methodology requires random digestion of a given genome into 150 to 500 base pair fragments, after which two unique bipartite primers (composed of both a PCR and sequencing region) are ligated onto the 5′ and 3′ ends of the fragments (FIG. 25). Unlike typical PCR amplifications where an existing section of the genome is chosen as a priming site based on melting temperature (T), uniqueness of the priming sequence within the genome and proximity to the particular region or gene of interest, the disclosed process utilizes synthetic priming sites that necessitates careful de novo primer design. Tetramer Selection: Strategies for de novo primer design are found in the published literature regarding work conducted on molecular tags for hybridization experiments (see, Hensel, M. and D. W. Holden, Molecular genetic approaches for the study of virulence in both pathogenic bacteria and fungi. Microbiology, 1996. 142(Pt 5): p. 1049-58; Shoemaker, D. D., et al., Quantitative phenotypic analysis of yeast deletion mutants using a highly parallel molecular bar-coding strategy. Nat Genet, 1996. 14(4): p. 450-6) and PCR/LDR (polymerase chain reaction/ligation detection reaction) hybridization primers (see, Gerry, N. P., et al., Universal DNA microarray method for multiplex detection of low abundance point mutations. Journal of Molecular Biology, 1999. 292: p. 251-262; Witowski, N. E., et al., Microarray-based detection of select cardiovascular disease markers. BioTechniques, 2000. 29(5): p. 936-944.). The PCR/LDR work was particularly relevant and focused on designing oligonucleotide “zipcodes”, 24 base primers comprised of six specifically designed tetramers with a similar final Tm. (see, Gerry, N. P., et al., Universal DNA microarray method for multiplex detection of low abundance point mutations. Journal of Molecular Biology, 1999. 292: p. 251-262; U.S. Pat. No. 6,506,594). Tetrameric components were chosen based on the following criteria: each tetramer differed from the others by at least two bases, tetramers that induced self-pairing or hairpin formations were excluded, and palindromic (AGCT) or repetitive tetramers (TATA) were omitted as well. Thirty-six of the 256 (44) possible permutations met the necessary requirements and were then subjected to further restrictions required for acceptable PCR primer design (Table 1). The table shows a matrix demonstrating tetrameric primer component selection based on criteria outlined by Gerry et al. 1999. J. Mol. Bio. 292: 251-262. Each tetramer was required to differ from all others by at least two bases. The tetramers could not be palindromic or complimentary with any other tetramer. Thirty-six tetramers were selected (bold, underlined); italicized sequences signal palindromic tetramers that were excluded from consideration. Primer Design: The PCR primers were designed to meet specifications common to general primer design (see, Rubin, E. and A. A. Levy, A mathematical model and a computerized simulation of PCR using complex templates. Nucleic Acids Res, 1996. 24(18): p. 3538-45; Buck, G. A., et al., Design strategies and performance of custom DNA sequencing primers. Biotechniques, 1999. 27(3): p. 528-36), and the actual selection was conducted by a computer program, MMP. Primers were limited to a length of 20 bases (5 tetramers) for efficient synthesis of the total bipartite PCR/sequencing primer. Each primer contained a two base GC clamp on the 5′ end, and a single GC clamp on the 3′ end (Table 2), and all primers shared similar Tm (+/−2° C.) (FIG. 27). No hairpinning within the primer (internal hairpin stem ΔG>−1.9 kcal/mol) was permitted. Dimerization was also controlled; a 3 base maximum acceptable dimer was allowed, but it could occur in final six 3′ bases, and the maximum allowable AG for a 3′ dimer was −2.0 kcal/mol. Additionally, a penalty was applied to primers in which the 3′ ends were too similar to others in the group, thus preventing cross-hybridization between one primer and the reverse complement of another. TABLE 2 1-pos 2-pos 3-pos 4-pos 5-pos 1 CCAT TGAT TGAT TGAT ATAC 2 CCTA CTCA CTCA CTCA AAAG 3 CGAA TACA TACA TACA TTAG 4 CGTT AGCC AGCC AGCC AATC 5 GCAA GACC GACC GACC TGTC 6 GCTT TCCC TCCC TCCC AGTG 7 GGAC ATCG ATCG ATCG CTTG 8 GGTA CACG CACG CACG GATG 9 TGCG TGCG TGCG TCTG 10 ACCT ACCT ACCT 11 GTCT GTCT GTCT 12 AGGA AGGA AGGA 13 TTGA TTGA TTGA 14 CAGC CAGC CAGC 15 GTGC GTGC GTGC 16 ACGG ACGG ACGG 17 CTGT CTGT CTGT 18 GAGT GAGT GAGT 19 TCGT TCGT TCGT Table 2 shows possible permutations of the 36 selected tetrads providing two 5′ and a single 3′ G/C clamp. The internal positions are composed of remaining tetrads. This results in 8×19×19×19×9 permutations, or 493,848 possible combinations. FIG. 27 shows first pass, Tm based selection of acceptable primers, reducing field of 493,848 primers to 56,246 candidates with Tm of 64 to 66° C. TABLE 3 The probability of perfect sequence matches for primers increases with decreasing match length requirements and increasing size of the genome of interest. Perfect % chance for % chance for match % chance match match in in NCBI bacterial for match Match probability Adeno database ˜488M in Human Length (1/(4{circumflex over ( )}length)) ˜35K bases bases ˜3B bases 20 9.1E−13 0.00% 0.04% 0.27% 19 7.3E−12 0.00% 0.65% 4.32% 18 4.4E−11 0.00% 5.76% 34.37% 17 2.3E−10 0.00% 35.69% 99.17% 16 1.2E−09 0.02% 97.52% >100% 15 5.6E−09 0.12% >100% >100% 14 2.6E−08 0.64% >100% >100% 13 1.2E−07 3.29% >100% >100% 12 5.4E−07 15.68% >100% >100% 11 2.4E−06 58.16% >100% >100% 10 1.0E−05 99.35% >100% >100% 9 4.6E−05 99.77% >100% >100% 8 2.0E−04 >100% >100% >100% 7 8.5E−04 >100% >100% >100% 6 3.7E−03 >100% >100% >100% 5 1.6E−02 >100% >100% >100% 4 6.4E−02 >100% >100% >100% 3 2.5E−01 >100% >100% >100% 2 7.1E−01 >100% >100% >100% 1 1.0E+00 >100% >100% >100% The possibility of complimentary regions occurring within the genome of interest was not a major concern in the primer design process despite the reported tolerance of PCR to mismatches in complex sample populations (see, e.g., Rubin, E. and A. A. Levy, A mathematical model and a computerized simulation of PCR using complex templates. Nucleic Acids Res, 1996. 24(18): p. 3538-45). Although the probability of finding a perfect match to a 20 base primer is extremely low (420) (Table 3), the probability of finding less non-consecutive matches increases significantly with the size of the genome of interest. As a result, the probability of finding a perfect match of at least 10 of 20 bases in 99.35% for an Adenovirus genome. The probability of finding a 16 base perfect match is 97% for the sequences in the NCBI database (approximately 100 times larger than the Adenovirus genome). The probability of finding a 17 base perfect match to a 20 base primer is 99% for the sequences in the human genome (3 billion bases). The high probability of primer cross-hybridization to regions of the genome is less problematic than one might expect due to the random DNA digestion used to produce the template fragments. Thus, the effects of a cross-hybridizing region (CHR) are fairly benign. It is unlikely that a CHR would be able to successfully compete with the perfect match between the PCR primers in solution and the template. In addition, any primers that include mismatches at their 3′ end would be at a significant competitive disadvantage. Even if a CHR should out compete the intended PCR primer, it would produce a truncated PCR product, without a downstream site for the sequencing primer. If the truncated product could be driven to the capture bead and immobilized, one of two situations would result. If the CHR out-competed the solution-phase primer, then the immobilized product would lack a sequencing primer binding site, and would result in an empty PicoTiter plate (PTP) well. If the CHR out-competed the bead-bound primer, the sequencing primer would still be present, and the only effect would be a shorter insert. Neither result would unduly compromise the sequencing quality. Given the large amount of genomic material used in the sample preparation process (currently 25 μg, containing 5.29×1016 copies of the 35 Kb Adenovirus genome), oversampling can be used to provide fragments that lack the complete CHR, and allow standard PCR amplification of the region in question. Example 3 Sample Preparation by Nebulization Preparation of DNA by Nebulization The purpose of the Nebulization step is to fragment a large stretch of DNA such as a whole genome or a large portion of a genome into smaller molecular species that are amenable to DNA sequencing. This population of smaller-sized DNA species generated from a single DNA template is referred to as a library. Nebulization shears double-stranded template DNA into fragments ranging from 50 to 900 base pairs. The sheared library contains single-stranded ends that are end-repaired by a combination of T4 DNA polymerase, E. Coli DNA polymerase I (Klenow fragment), and T4 polynucleotide kinase. Both T4 and Klenow DNA polymerases are used to “fill-in” 3′ recessed ends (5′ overhangs) of DNA via their 5′-3′ polymerase activity. The single-stranded 3′-5′ exonuclease activity of T4 and Klenow polymerases will remove 3′ overhang ends and the kinase activity of T4 polynucleotide kinase will add phosphates to 5′ hydroxyl termini. The sample was prepared as follows: 1. 15 μg of gDNA (genomic DNA) was obtained and adjusted to a final volume of 100 μl in 10 mM TE (10 mM Tris, 0.1 mM EDTA, pH 7.6; see reagent list at the end of section). The DNA was analyzed for contamination by measuring the O.D.260/280 ratio, which was 1.8 or higher. The final gDNA concentration was expected to be approximately 300 μg/ml. 2. 1600 μl of ice-cold Nebulization Buffer (see end of section) was added to the gDNA. 3. The reaction mixture was placed in an ice-cold nebulizer (CIS-US, Bedford, Mass.). 4. The cap from a 15 ml snap cap falcon tube was placed over the top of the nebulizer (FIG. 28A). 5. The cap was secured with a clean Nebulizer Clamp assembly, consisting of the fitted cover (for the falcon tube lid) and two rubber O-rings (FIG. 28B). 6. The bottom of the nebulizer was attached to a nitrogen supply and the entire device was wrapped in parafilm (FIGS. 28C and 28D). 7. While maintaining nebulizer upright (as shown in FIG. 28D), 50 psi (pounds per square inch) of nitrogen was applied for 5 minutes. The bottom of the nebulizer was tapped on a hard surface every few seconds to force condensed liquid to the bottom. 8. Nitrogen was turned off after 5 minutes. After the pressure had normalized (30 seconds), the nitrogen source was remove from the nebulizer. 9. The parafilm was removed and the nebulizer top was unscrewed. The sample was removed and transferred to a 1.5 ml microcentrifuge tube. 10. The nebulizer top was reinstalled and the nebulizer was centrifuged at 500 rpm for 5 minutes. 11. The remainder of the sample in the nebulizer was collected. Total recovery was about 700 μl. 12. The recovered sample was purified using a QIAquick column (Qiagen Inc., Valencia, Calif.) according to manufacturer's directions. The large volume required the column to be loaded several times. The sample was eluted with 30 μl of Buffer EB (10 mM Tris HCl, pH 8.5; supplied in Qiagen kit) which was pre-warmed at 55° C. 13. The sample was quantitated by UV spectroscopy (2 μl in 198 μl water for 1:100 dilution). Enzymatic Polishing Nebulization of DNA templates yields many fragments of DNA with frayed ends. These ends are made blunt and ready for ligation to adaptor fragments by using three enzymes, T4 DNA polymerase, E. coli DNA polymerase (Klenow fragment) and T4 polynucleotide kinase. The sample was prepared as follows: 1. In a 0.2 ml tube the following reagents were added in order: 28 μl purified, nebulized gDNA fragments 5 μl water 5 μl 10×T4 DNA polymerase buffer 5 μl BSA (1 mg/ml) 2 μl dNTPs (10 mM) 5 μl T4 DNA polymerase (3 units/μl) 50 μl final volume 2. The solution of step 1 was mixed well and incubated at 25° C. for 10 minutes in a MJ thermocycler (any accurate incubator may be used). 3. 1.25 μl E. coli DNA polymerase (Klenow fragment) (5 units/ml) was added. 4. The reaction was mixed well and incubated in the MJ thermocycler for 10 minutes at 25° C. and for an additional 2 hrs at 16° C. 5. The treated DNA was purified using a QiaQuick column and eluted with 30 μl of Buffer EB (10 mM Tris HCl, pH 8.5) which was pre-warmed at 55° C. 6. The following reagents were combined in a 0.2 ml tube: 30 μl Qiagen purified, polished, nebulized gDNA fragments 5 μl water 5 μl 10×T4 PNK buffer 5 μl ATP (10 mM) 5 μl T4 PNK (10 units/ml) 50 μl final volume 7. The solution was mixed and placed in a MJ thermal cycler using the T4 PNK program for incubation at 37° C. for 30 minutes, 65° C. for 20 minutes, followed by storage at 14° C. 8. The sample was purified using a QiaQuick column and eluted in 30 μl of Buffer EB which was pre-warmed at 55° C. 9. A 2 μl aliquot of the final polishing reaction was held for analysis using a BioAnalyzer DNA 1000 LabChip (see below). Ligation of Adaptors The procedure for ligating the adaptors was performed as follows: 1. In a 0.2 ml tube the following reagents were added in order: 20.6 μl molecular biology grade water 28 μl digested, polished gDNA Library 60 μl 2× Quick Ligase Reaction Buffer 1.8 μl MMP (200 pmol/μl) Universal Adaptor set 9.6 μl Quick Ligase 120 μl total The above reaction was designed for 5 μg and was scaled depending on the amount of gDNA used. 2. The reagents were mixed well and incubated at 25° C. for 20 minutes. The tube was on ice until the gel was prepared for agarose gel electrophoresis. Gel Electrophoresis and Extraction of Adapted gDNA Library Nebulization of genomic DNA yields a library population that ranges from 50-900 bp. The addition of the 88-bp Universal Adaptor set will shift the population to a larger size and will result in a migration profile with a larger size range (approximately 130-980 bp). Adaptor dimers will migrate at 88 bp and adaptors not ligated will migrate at 44 bp. Therefore, genomic DNA libraries isolated in size ranges>250 bp can be physically isolated from the agarose gel and purified using standard gel extraction techniques. Gel isolation of the adapted gDNA library will result in the recovery of a library population in a size range that is >250 bp (size range of library can be varied depending on application). The library size range after ligation of adapters is 130 to 980 bp. It should be noted that the procedure may be adapted for isolation of any band size range, such as, for example, 130 to 200 bp, 200 to 400 bp, 250 to 500 bp, 300 to 600 bp, 500 to 700 bp and the like by cutting different regions of the gel. The procedure described below was used to isolated fragments of 250 bp to 500 bp. A 150 ml agarose gel was prepared to include 2% agarose, 1×TBE, and 4.5 μl ethidium bromide (10 mg/ml stock). The ligated DNA was mixed with 10× Ready Load Dye and loaded onto the gel. In addition, 10 μl of a 100-bp ladder (0.1 μg/μl) was loaded on two lanes away from the ligation reaction flanking the sample. The gel was electrophoresed at 100 V for 3 hours. When the gel run was complete, the gel was removed from the gel box, transferred to a GelDoc, and covered with plastic wrap. The DNA bands were visualized using the Prep UV light. A sterile, single-use scalpel, was used to cut out a library population from the agarose gel with fragment sizes of 250-500 bp. This process was done as quickly as possible to prevent nicking of DNA. The gel slices were placed in a 15 ml falcon tube. The agarose-embedded gDNA library was isolated using a Qiagen MinElute Gel Extraction kit. Aliquots of each isolated gDNA library were analyzed using a BioAnalyzer DNA 1000 LabChip to assess the exact distribution of the gDNA library population. Strand Displacement and Extension of the gDNA Library and Isolation of the Single Stranded gDNA Library Using Streptavidin Beads Strand displacement and extension of nicked double-stranded gDNA library was performed as described in Example 1, with the exception that the Bst-treated samples were incubated in the thermal cycler at 65° C. for 30 minutes and placed on ice until needed. Streptavidin beads were prepared as described in Example 1, except that the final wash was performed using two washes with 200 μl 1× Binding buffer and two washes with 200 μl nH2O. Single-stranded gDNA library was isolated using streptavidin beads as follows. Water from the washed beads was removed and 250 μl of Melt Solution (see below) was added. The bead suspension was mixed well and incubated at room temperature for 10 minutes on a tube rotator. In a separate tube, 1250 μl of PB (from the QiaQuick Purification kit) and 9 μl of 20% acetic acid were mixed. The beads in 250 μl Melt Solution were pelleted using a Dynal MPC and the supernatant was carefully removed and transferred to the freshly prepared PB/acetic acid solution. DNA from the 1500 μl solution was purified using a single MinElute purification spin column. This was performed by loading the sample through the same column twice at 750 μl per load. The single stranded gDNA library was eluted with 15 μl of Buffer EB which was pre-warmed at 55° C. Single Strand gDNA Quantitation and Storage Single-stranded gDNA was quantitated using RNA Pico 6000 LabChip as described in Example 1. In some cases, the single stranded library was quantitated by a second assay to ensure the initial Agilent 2100 quantitation was performed accurately. For this purpose, RiboGreen quantitation was performed as described (ssDNA Quantitation by Fluorometry) to confirm the Agilent 2100 quantitation. If the two estimates differed by more than 3 fold, each analysis was repeated. If the quantitation showed greater than a 3 fold difference between the two procedures, a broader range of template to bead was used. Dilution and storage of the single stranded gDNA library was performed as described in Example 1. The yield was as follows: Remaining final volume of ssDNA library following LabChip analysis=12 μl. Remaining final volume of ssDNA library following RiboGreen analysis=9 μl. Final volume of ssDNA library after the addition of TE=18 μl. An equal volume of TE was added to single-stranded gDNA library stock. Single-stranded gDNA library to 1×108 molecules/μl in Buffer TE. Stock was diluted ({fraction (1/500)}) to 200,000 molecules/μl in TE and 20 μl aliquots were prepared. Library Fragment Size Distribution after Nebulization Typical results from Agilent 2100 DNA 1000 LabChip analysis of 1 μl of the material following Nebulization and polishing are shown in FIG. 29A. The size range distribution of the majority of the product was expected to fall around 50 to 900 base pairs. The mean size (top of peak) was expected to be approximately 450 bp. Typical results from gel purification of adaptor ligated library fragments are shown in FIG. 29B. Reagents Unless otherwise specified, the reagents listed in the Examples represent standard reagents that are commercially available. For example, Klenow, T4 DNA polymerase, T4 DNA polymerase buffer, T4 PNK, T4 PNK buffer, Quick T4 DNA Ligase, Quick Ligation Buffer, Bst DNA polymerase (Large Fragment) and ThermoPol reaction buffer are available from New England Biolabs (Beverly, Mass.). dNTP mix is available from Pierce (Rockford, Ill.). Agarose, UltraPure TBE, BlueJuice gel loading buffer and Ready-Load 100 bp DNA ladder may be purchased from Invitrogen (Carlsbad, Calif.). Ethidium Bromide and 2-Propanol may be purchased from Fisher (Hampton, N.H.). RNA Ladder may be purchased from Ambion (Austin, Tex.). Other reagents are either commonly known and/or are listed below: Melt Solution: Ingredient Quantity Required Vendor Stock Number NaCl (5 M) 200 μl Invitrogen 24740-011 NaOH (10 N) 125 μl Fisher SS255-1 molecular biology 9.675 ml Eppendorf 0032-006-205 grade water The Melt Solution included 100 mM NaCl, and 125 mM NaOH. The listed reagents were combined and mixed thoroughly. The solution could be stored at RT for six months. Binding & Washing (B&W) Buffer (2× and 1×): Ingredient Quantity Required Vendor Stock Number UltraPure Tris-HCl 250 μl Invitrogen 15567-027 (pH 7.5, 1 M) EDTA (0.5 M) 50 μl Invitrogen 15575-020 NaCl (5 M) 10 ml Invitrogen 24740-011 molecular biology 14.7 ml Eppendorf 3200-006-205 grade water The 2×B&W buffer included final concentrations of 10 mM Tris-HCl (pH 7.5), 1 mM EDTA, and 2 M NaCl. The listed reagents were combined by combined and mixed thoroughly. The solution could be stored at RT for 6 months. The 1×B&W buffer was prepared by mixing 2×B&W buffer with picopure H20, 1:1. The final concentrations was half of that listed the above, i.e., 5 mM Tris-HCl (pH 7.5), 0.5 mM EDTA, and 1 M NaCl. Other buffers included the following. 1×T4 DNA Polymerase Buffer: 50 mM NaCl, 10 mM Tris-HCl, 10 mM MgCl2, 1 mM dithiothreitol (pH 7.9 @ 25° C.). TE: 10 mM Tris, 1 mM EDTA. Special Reagent Preparation: TE (10 mM): Ingredient Quantity Required Vendor Stock Number TE (1M) 1 ml Fisher BP1338-1 molecular biology 99 ml Eppendorf 0032-006-205 grade water Reagents were mixed and the solution could be stored RT for six months. Nebulization Buffer: Ingredient Quantity Required Vendor Stock Number Glycerol 53.1 ml Sigma G5516 molecular biology 42.1 ml Eppendorf 3200-006-205 grade water UltraPure Tris-HCl 3.7 ml Invitrogen 15567-027 (pH 7.5, 1M) EDTA (0.5M) 1.1 ml Sigma M-10228 All reagents were added (glycerol was added last) to a Stericup and mixed well. The solution was labeled and could be stored at RT for six months. ATP (10 mM): Ingredient Quantity Required Vendor Stock Number ATP (100 mM) 10 μl Roche 1140965 molecular biology 90 μl Eppendorf 0032-006-205 grade water The reagents were mixed and the solution could be stored at −20° C. for six months. BSA (1 mg/ml): Ingredient Quantity Required Vendor Stock Number BSA (10 mg/ml) 10 μl NEB M0203 kit Molecular Biology 90 μl Eppendorf 0032-006-205 Grade water The reagents were mixed and the solution could be stored at 4° C. for six months. Library Annealing buffer, 10×: Ingredient Quantity Req. Vendor Stock No. UltraPure Tris-HCl 200 ml Invitrogen 15567-027 (pH 7.5, 1 M) Magnesium acetate, 10.72 g Fisher BP-215-500 enzyme grade (1 M) Molecular Biology ˜1 L Eppendorf 3200-006-205 Grade water The 10× Annealing Buffer included 200 mM Tris (pH 7.5) and 50 mM magnesium acetate. For this buffer, 200 ml of Tris was added to 500 ml picopure H2O. Next, 10.72 g of magnesium acetate was added to the solution and dissolved completely. The solution was adjusted to a final volume of 1000 ml. The solution could be stored at 4° C. for six months. To avoid the potential for contamination of libraries, the buffer was aliquotted for single or short-term usage. Adaptors: Adaptor “A” (400 μM): Ingredient Quantity Req. Vendor Stock No. Adaptor A (sense; HPLC- 10.0 μl IDT custom purified, phosphorothioate linkages, 44 bp, 1000 pmol/μl) Adaptor A (antisense; 10.0 μl IDT custom HPLC-purified, Phosphorothioate linkages, 40 bp, 1000 pmol/μl) Annealing buffer (10×) 2.5 μl 454 Corp. previous table molecular biology grade 2.5 μl Eppendorf 0032-006-205 water For this solution, 10 μl of 1000 pmol/μl Adaptor A (44 bp, sense) was mixed with 10 μl of 1000 pmol/μl Adaptor A (40 bp, antisense), 2.5 μl of 10×Library Annealing Buffer, and 2.5 μl of water (Vf=25 μl). The adaptors were annealed using the ANNEAL-A program (see Appendix, below) on the Sample Prep Lab thermal cycler. More details on adaptor design are provided in the Appendix. Adaptor “B” (400 μM): Ingredient Quantity Req. Vendor Stock No. Adaptor B (sense; HPLC- 10 μl IDT Custom purified, phosphorothioate linkages, 40 bp, 1000 pmol/μl)) Adaptor B (anti; HPLC- 10 μl IDT Custom purified, phosphorothioate linkages, 5′Biotinylated, 44 bp, 1000 pmol/μl) Annealing buffer (10×) 2.5 μl 454 Corp. previous table molecular biology grade 2.5 μl Eppendorf 0032-006-205 water For this solution, 10 μl of 1000 pmol/μl Adaptor B (40 bp, sense) was mixed with 10 μl of 1000 pmol/μl Adaptor B (44 bp, anti), 2.5 μl of 10× Library Annealing Buffer, and 2.5 μl of water (Vf=25 μl). The adaptors were annealed using the ANNEAL-A program (see Appendix) on the Sample Prep Lab thermal cycler. After annealing, adaptor “A” and adaptor “B” (Vf=50 μl) were combined. Adaptor sets could be stored at −20° C. until use. 20% Acetic Acid: Ingredient Quantity Required Vendor Stock Number acetic acid, glacial 2 ml Fisher A35-500 molecular biology 8 ml Eppendorf 0032-006-205 grade water For this solution, glacial acetic acid was added to the water. The solution could be stored at RT for six months. Adaptor Annealing Program: ANNEAL-A program for primer annealing: 1. Incubate at 95° C., 1 min; 2. Reduce temperature to 15° C. at 0.1° C./sec; and 3. Hold at 14° C. T4 Polymerase/Klenow POLISH program for end repair: 1. Incubate at 25° C., 10 minutes; 2. Incubate at 16° C., 2 hours; and 3. Hold at 4° C. T4 PNK Program for end repair: 1. Incubate at 37° C., 30 minutes; 2. Incubate at 65° C., 20 minutes; and 3. Hold at 14° C. BST program for stand displacement and extension of nicked double-stranded gDNA: 1. Incubate at 65° C., 30 minutes; and 2. Hold at 14° C. Step 9: Dilution and Storage of Single-Stranded DNA Library Single-stranded DNA library in EB buffer: remaining final volume=25 μl. Initial Stock dilution was made as follows. Using Pyrosequencing (Pyrosequencing AB, Uppsala, Sweden) results, single-stranded DNA library was diluted to 100M molecules/μL in 1× Annealing Buffer (usually this was a 1:50 dilution). Aliquots of single-stranded DNA Library were made for common use by diluting 200,000 molecules/μL in 1× Annealing Buffer and preparing 30 μL aliquots. Store at −20° C. Samples were utilized in emulsion PCR. Reagent Preparation: Stop Solution (50 mM EDTA): 100 μl of 0.5 M EDTA was mixed with 900 μl of nH2O to make 1.0 ml of 50 mM EDTA solution. Solution of 10 mM dNTPs included 10 μl dCTP (100 mM), 10 μl dATP (100 mM), 10 μl dGTP (100 mM), and 10 μl dTTP (100 mM), 60 μl Molecular Biology Grade water, (nH2O). All four 100 mM nucleotide stocks were thawed on ice. 10 μl of each nucleotide was combined with 60 μl of nH2O to a final volume of 100 μl, and mixed thoroughly. 1 ml aliquots were dispensed into 1.5 ml microcentrifuge tubes, and stored at −20° C., no longer than one year. Annealing buffer, 10×: 10× Annealing buffer included 200 mM Tris (pH 7.5) and 50 mM magnesium acetate. For this solution, 24.23 g Tris was added to 800 ml nH2O and adjusted to pH 7.5. To this, 10.72 g magnesium acetate was added and dissolved completely. The solution was brought up to a final volume of 1000 ml. The solution was able be stored at 4° C. for 1 month. 10×TE: 10×TE included 100 mM Tris.HCl (pH 7.5), and 50 mM EDTA. These reagents were added together and mixed thoroughly. The solution could be stored at room temperature for 6 months. Example 4 Bead Emulsion PCR The following procedures, including capture of the template DNA, DNA amplification, and recovery of the beads bound to amplified template, can be performed in a single tube. The emulsion format ensures the physical separation of the beads into 100-200 μm “microreactors” within this single tube, thus allowing for clonal amplification of the various templates. Immobilization of the amplification product is achieved through extension of the template along the oligonucleotides bound to the DNA capture beads. Typical, the copy number of the immobilized template ranges from 10 to 30 million copies per bead. The DNA capture beads affixed with multiple copies of a single species of nucleic acid template are ready for distribution onto PTPs. The 300,000 75-picoliter wells etched in the PTP surface provide a unique array for the sequencing of short DNA templates in a massively parallel, efficient and cost-effective manner. However, this requires fairly large quantities (millions of copies) of clonal templates in each reaction well. The methods of the invention allow the user to clonally amplify single-stranded genomic template species thorough PCR reactions conducted in standard tubes or microtiter plates. Single copies of the template species may be mixed with capture beads, resuspended into complete PCR amplification solution, and emulsified into microreactors (100 to 200 μm in diameter), after which PCR amplification generates 107-fold amplification of the initial template species. This procedure is much simpler and more cost-effective than previous methods. Binding Nucleic Acid Template to Capture Beads This example describes preparation of a population of beads that preferably have only one unique nucleic acid template attached thereto. Successful clonal amplification depends on the delivery of a controlled number of template species (0.5 to 1) to each bead. Delivery of excess species can result in PCR amplification of a mixed template population, preventing generation of meaningful sequence data while a deficiency of species will result in fewer wells containing template for sequencing. This can reduce the extent of genome coverage provided by the sequencing phase. As a result, it is preferred that the template concentration be accurately determined through replicated quantitation, and that the binding protocol be followed as outlined below. Template Quality Control The success of the Emulsion PCR reaction is related to the quality of the template species. Regardless of the care and detail paid to the amplification phase, poor quality templates will impede successful amplification and the generation of meaningful sequence data. To prevent unnecessary loss of time and money, it is important to check the quality of the template material before initiating the Emulsion PCR phase of the process. Preferably, the library should pass two quality control steps before it is used in Emulsion PCR. Its concentration and the distribution of products it contains should be determined. Ideally, the library should appear as a heterogeneous population of fragments with little or no visible adapter dimers (e.g., ˜90 bases). Also, amplification with PCR primers should result in a product smear ranging, for example, from 300 to 500 bp. Absence of amplification product may reflect failure to properly ligate the adaptors to the template, while the presence of a single band of any size may reflect contamination of the template. Preparation of the PCR Solution The main consideration for this phase is to prevent contamination of the PCR reaction mixture with stray amplicons. Contamination of the PCR reactions with a residual amplicon is one of the critical issues that can cause failure of a sequencing run. To reduce the possibility of contamination, proper lab technique should be followed, and reaction mixture preparation should be conducted in a clean room in a UV-treated laminar flow hood. PCR Reaction Mix: For 200 μl PCR reaction mixture (enough for amplifying 600,000 beads), the following reagents were combined in a 0.2 ml PCR tube: TABLE 4 Stock Final Microliters HIFI Buffer 10× 1× 20 treated nucleotide 10 mM 1 mM 20 Mg 50 mM 2 mM 8 BSA 10% 0.1% 2 Tween 80 1% 0.01% 2 Ppase 2 U 0.003 U 0.333333 Primer MMP1a 100 μM 0.625 μM 1.25 Primer MMP1b 10 μM 0.078 μM 1.56 Taq polymerase 5 U 0.2 U 8 Water 136.6 Total 200 The tube was vortexed thoroughly and stored on ice until the beads are annealed with template. DNA Capture Beads: 1. 600,000 DNA capture beads were transferred from the stock tube to a 1.5 ml microfuge tube. The exact amount used will depend on bead concentration of formalized reagent. 2. The beads were pelleted in a benchtop mini centrifuge and supernatant was removed. 3. Steps 4-11 were performed in a PCR Clean Room. 4. The beads were washed with 1 mL of 1× Annealing Buffer. 5. The capture beads were pelleted in the microcentrifuge. The tube was turned 180° and spun again. 6. All but approximately 10 μl of the supernatant was removed from the tube containing the beads. The beads were not disturbed. 7. 1 mL of 1× Annealing Buffer was added and this mixture was incubated for 1 minute. The beads were then pelleted as in step 5. 8. All but approximately 100 μL of the material from the tube was removed. 9. The remaining beads and solution were transferred to a PCR tube. 10. The 1.5 mL tube was washed with 150 μL of 1× Annealing Buffer by pipetting up and down several times. This was added to the PCR tube containing the beads. 11. The beads were pelleted as in step 5 and all but 10 μL of supernatant was removed, taking care to not disturb the bead pellet. 12. An aliquot of quantitated single-stranded template DNA (sstDNA) was removed. The final concentration was 200,000-sst DNA molecules/μl. 13. 3 μl of the diluted sstDNA was added to PCR tube containing the beads. This was equivalent to 600,000 copies of sstDNA. 14. The tube was vortexed gently to mix contents. 15. The sstDNA was annealed to the capture beads in a PCR thermocycler with the program 80Anneal stored in the EPCR folder on the MJ Thermocycler, using the following protocol: 5 minutes at 65° C.; Decrease by 0.1° C./sec to 60° C.; Hold at 60° C. for 1 minute; Decrease by 0.1° C./sec to 50° C.; Hold at 50° C. for 1 minute; Decrease by 0.1° C./sec to 40° C.; Hold at 40° C. for 1 minute; Decrease by 0.1° C./sec to 20° C.; and Hold at 10° C. until ready for next step. In most cases, beads were used for amplification immediately after template binding. If beads were not used immediately, they should were stored in the template solution at 4° C. until needed. After storage, the beads were treated as follows. 16. As in step 6, the beads were removed from the thermocycler, centrifuged, and annealing buffer was removed without disturbing the beads. 17. The beads were stored in an ice bucket until emulsification (Example 2). 18. The capture beads included, on average, 0.5 to 1 copies of sstDNA bound to each bead, and were ready for emulsification. Example 5 Emulsification A PCR solution suitable for use in this step is described below. For 200 μl PCR reaction mix (enough for amplifying 600K beads), the following were added to a 0.2 ml PCR tube: Stock Final Microliters HIFI Buffer 10× 1× 20 treated Nukes 10 mM 1 mM 20 Mg 50 mM 2 mM 8 BSA 10% 0.1% 2 Tween 80 1% 0.01% 2 Ppase 2 U 0.003 U 0.333333 Primer MMP1a 100 μM 0.625 μM 1.25 Primer MMP1b 10 μM 0.078 μM 1.56 Taq 5 U 0.2 U 8 Water 136.6 Total 200 This example describes how to create a heat-stable water-in-oil emulsion containing about 3,000 PCR microreactors per microliter. Outlined below is a protocol for preparing the emulsion. 1. 200 μl of PCR solution was added to the 600,000 beads (both components from Example 1). 2. The solution was pipetted up and down several times to resuspend the beads. 3. The PCR-bead mixture was allowed to incubate at room temperature for 2 minutes to equilibrate the beads with PCR solution. 4. 400 μl of Emulsion Oil was added to a UV-irradiated 2 ml microfuge tube. 5. An “amplicon-free” ¼″ stir magnetic stir bar was added to the tube of Emulsion Oil. An amplicon-free stir bar was prepared as follows. A large stir bar was used to hold a ¼″ stir bar. The stir bar was then: Washed with DNA-Off (drip or spray); Rinsed with picopure water; Dried with a Kimwipe edge; and UV irradiated for 5 minutes. 6. The magnetic insert of a Dynal MPC-S tube holder was removed. The tube of Emulsion Oil was placed in the tube holder. The tube was set in the center of a stir plate set at 600 rpm. 7. The tube was vortexed extensively to resuspend the beads. This ensured that there was minimal clumping of beads. 8. Using a P-200 pipette, the PCR-bead mixture was added drop-wise to the spinning oil at a rate of about one drop every 2 seconds, allowing each drop to sink to the level of the magnetic stir bar and become emulsified before adding the next drop. The solution turned into a homogeneous milky white liquid with a viscosity similar to mayonnaise. 9. Once the entire PCR-bead mixture was been added, the microfuge tube was flicked a few times to mix any oil at the surface with the milky emulsion. 10. Stirring was continued for another 5 minutes. 11. Steps 9 and 10 were repeated. 12. The stir bar was removed from the emulsified material by dragging it out of the tube with a larger stir bar. 13.10 μL of the emulsion was removed and placed on a microscope slide. The emulsion was covered with a cover slip and the emulsion was inspected at 50× magnification (10× ocular and 5× objective lens). A “good” emulsion was expected to include primarily single beads in isolated droplets (microreactors) of PCR solution in oil. 14. A suitable emulsion oil mixture with emulsion stabilizers was made as follows. The components for the emulsion mixture are shown in Table 5. TABLE 5 Quantity Ingredient Required Source Ref. Number Sigma Light Mineral Oil 94.5 g Sigma M-5904 Atlox 4912 1 g Uniqema NA Span 80 4.5 g Uniqema NA The emulsion oil mixture was made by prewarming the Atlox 4912 to 60° C. in a water bath. Then, 4.5 grams of Span 80 was added to 94.5 grams of mineral oil to form a mixture. Then, one gram of the prewarmed Atlox 4912 was added to the mixture. The solutions were placed in a closed container and mixed by shaking and inversion. Any sign that the Atlox was settling or solidifying was remedied by warming the mixture to 60° C., followed by additional shaking. Example 6 Amplification This example describes amplification of the template DNA in the bead—emulsion mixture. According to this protocol of the invention, the DNA amplification phase of the processtakes 3 to 4 hours. After the amplification is complete, the emulsion may be left on the thermocycler for up to 12 hours before beginning the process of isolating the beads. PCR thermocycling was performed by placing 50 to 100 μl of the emulsified reaction mixture into individual PCR reaction chambers (i.e., PCR tubes). PCR was performed as follows: 1. The emulsion was transferred in 50-100 μL amounts into approximately 10 separate PCR tubes or a 96-well plate using a single pipette tip. For this step, the water-in-oil emulsion was highly viscous. 2. The plate was sealed, or the PCR tube lids were closed, and the containers were placed into in a MJ thermocycler with or without a 96-well plate adaptor. 3. The PCR thermocycler was programmed to run the following program: 1 cycle (4 minutes at 94° C.)—Hotstart Initiation; 40 cycles (30 seconds at 94° C., 30 seconds at 58° C., 90 seconds at 68° C.); 25 cycles (30 seconds at 94° C., 6 minutes at 58° C.); and Storage at 14° C. 4. After completion of the PCR reaction, the amplified material was removed in order to proceed with breaking the emulsion and bead recovery. Example 7 Breaking the Emulsion and Bead Recovery This example describes how to break the emulsion and recover the beads with amplified template thereon. Preferably, the post-PCR emulsion should remain intact. The lower phase of the emulsion should, by visual inspection, remain a milky white suspension. If the solution is clear, the emulsion may have partially resolved into its aqueous and oil phases, and it is likely that many of the beads will have a mixture of templates. If the emulsion has broken in one or two of the tubes, these samples should not be combined with the others. If the emulsion has broken in all of the tubes, the procedure should not be continued. 1. All PCR reactions from the original 600 μl sample were combined into a single 1.5 ml microfuge tube using a single pipette tip. As indicated above, the emulsion was quite viscous. In some cases, pipetting was repeated several times for each tube. As much material as possible was transferred to the 1.5 ml tube. 2. The remaining emulsified material was recovered from each PCR tube by adding 50 μl of Sigma Mineral Oil into each sample. Using a single pipette tip, each tube was pipetted up and down a few times to resuspend the remaining material. 3. This material was added to the 1.5 ml tube containing the bulk of the emulsified material. 4. The sample was vortexed for 30 seconds. 5. The sample was spun for 20 minutes in the tabletop microfuge tube at 13.2K rpm in the Eppendorf microcentrifuge. 6. The emulsion separated into two phases with a large white interface. As much of the top, clear oil phase as possible was removed. The cloudy material was left in the tube. Often a white layer separated the oil and aqueous layers. Beads were often observed pelleted at the bottom of the tube. 7. The aqueous layer above the beads was removed and saved for analysis (gel analysis, Agilent 2100, and Taqman). If an interface of white material persisted above the aqueous layer, 20 microliters of the underlying aqueous layer was removed. This was performed by penetrating the interface material with a pipette tip and withdrawing the solution from underneath. 8. In the PTP Fabrication and Surface Chemistry Room Fume Hood, 1 ml of Hexanes was added to the remainder of the emulsion. 9. The sample was vortexed for 1 minute and spun at full speed for 1 minute. 10. In the PTP Fabrication and Surface Chemistry Room Fume Hood, the top, oil/hexane phase was removed and placed into the organic waste container. 11. 1 ml of 1× Annealing Buffer was added in 80% Ethanol to the remaining aqueous phase, interface, and beads. 12. The sample was vortexed for 1 minute or until the white substance dissolved. 13. The sample was centrifuged for 1 minute at high speed. The tube was rotated 180 degrees, and spun again for 1 minute. The supernatant was removed without disturbing the bead pellet. 14. The beads were washed with 1 ml of 1× Annealing Buffer containing 0.1% Tween 20 and this step was repeated. Example 8 Single Strand Removal and Primer Annealing If the beads are to be used in a pyrophosphate-based sequencing reaction, then it is necessary to remove the second strand of the PCR product and anneal a sequencing primer to the single stranded template that is bound to the bead. This example describes a protocol for accomplishing that. 1. The beads were washed with 1 ml of water, and spun twice for 1 minute. The tube was rotated 180° between spins. After spinning, the aqueous phase was removed. 2. The beads were washed with 1 ml of 1 mM EDTA. The tube was spun as in step 1 and the aqueous phase was removed. 3. 1 ml of 0.125 M NaOH was added and the sample was incubated for 8 minutes. 4. The sample was vortexed briefly and placed in a microcentrifuge. 5. After 6 minutes, the beads were pelleted as in step 1 and as much solution as possible was removed. 6. At the completion of the 8 minute NaOH incubation, 1 ml of 1× Annealing Buffer was added. 7. The sample was briefly vortexed, and the beads were pelleted as in step 1. As much supernatant as possible was removed, and another 1 ml of 1× Annealing buffer was added. 8. The sample was briefly vortexed, the beads were pelleted as in step 1, and 800 μl of 1× Annealing Buffer was removed. 9. The beads were transferred to a 0.2 ml PCR tube. 10. The beads were transferred and as much Annealing Buffer as possible was removed, without disturbing the beads. 11. 100 μl of 1× Annealing Buffer was added. 12. 4 μl of 100 μM sequencing primer was added. The sample was vortexed just prior to annealing. 13. Annealing was performed in a MJ thermocycler using the “80Anneal” program. 14. The beads were washed three times with 200 μl of 1× Annealing Buffer and resuspended with 100 μl of 1× Annealing Buffer. 15. The beads were counted in a Hausser Hemacytometer. Typically, 300,000 to 500,000 beads were recovered (3,000-5,000 beads/μL). 16. Beads were stored at 4° C. and could be used for sequencing for 1 week. Example 9 Optional Enrichment Step The beads may be enriched for amplicon containing bead using the following procedure. Enrichment is not necessary but it could be used to make subsequent molecular biology techniques, such as DNA sequencing, more efficient. Fifty microliters of 10 μM (total 500 pmoles) of biotin-sequencing primer was added to the Sepharose beads containing amplicons from Example 5. The beads were placed in a thermocycler. The primer was annealed to the DNA on the bead by the thermocycler annealing program of Example 2. After annealing, the sepharose beads were washed three times with Annealing Buffer containing 0.1% Tween 20. The beads, now containing ssDNA fragments annealed with biotin-sequencing primers, were concentrated by centrifugation and resuspended in 200 pt of BST binding buffer. Ten microliters of 50,000 unit/ml Bst-polymerase was added to the resuspended beads and the vessel holding the beads was placed on a rotator for five minutes. Two microliters of 10 mM dNTP mixture (i.e., 2.5 μl each of 10 mM dATP, dGTP, dCTP and dTTP) was added and the mixture was incubated for an additional 10 minutes at room temperature. The beads were washed three times with annealing buffer containing 0.1% Tween 20 and resuspended in the original volume of annealing buffer. Fifty microliters of Dynal Streptavidin beads (Dynal Biotech Inc., Lake Success, N.Y.; M270 or MyOne™ beads at 10 mg/ml) was washed three times with Annealing Buffer containing 0.1% Tween 20 and resuspended in the original volume in Annealing Buffer containing 0.1% Tween 20. Then the Dynal bead mixture was added to the resuspended sepharose beads. The mixture was vortexed and placed in a rotator for 10 minutes at room temperature. The beads were collected on the bottom of the test tube by centrifugation at 2300 g (500 rpm for Eppendorf Centrifuge 5415D). The beads were resuspended in the original volume of Annealing Buffer containing 0.1% Tween 20. The mixture, in a test tube, was placed in a magnetic separator (Dynal). The beads were washed three times with Annealing Buffer containing 0.1% Tween 20 and resuspended in the original volume in the same buffer. The beads without amplicons were removed by wash steps, as previously described. Only Sepharose beads containing the appropriated DNA fragments were retained. The magnetic beads were separated from the sepharose beads by addition of 500 μl of 0.125 M NaOH. The mixture was vortexed and the magnetic beads were removed by magnetic separation. The Sepharose beads remaining in solution was transferred to another tube and washed with 400 μl of 50 mM Tris Acetate until the pH was stabilized at 7.6. Example 10 Nucleic Acid Sequencing Using Bead Emulsion PCR The following experiment was performed to test the efficacy of the bead emulsion PCR. For this protocol, 600,000 Sepharose beads, with an average diameter of 25-35 μm (as supplied my the manufacturer) were covalently attached to capture primers at a ratio of 30-50 million copies per bead. The beads with covalently attached capture primers were mixed with 1.2 million copies of single stranded Adenovirus Library. The library constructs included a sequence that was complimentary to the capture primer on the beads. The adenovirus library was annealed to the beads using the procedure described in Example 1. Then, the beads were resuspended in complete PCR solution. The PCR Solution and beads were emulsified in 2 volumes of spinning emulsification oil using the same procedure described in Example 2. The emulsified (encapsulated) beads were subjected to amplification by PCR as outlined in Example 3. The emulsion was broken as outlined in Example 4. DNA on beads was rendered single stranded, sequencing primer was annealed using the procedure of Example 5. Next, 70,000 beads were sequenced simultaneously by pyrophosphate sequencing using a pyrophosphate sequencer from 454 Life Sciences (New Haven, Conn.) (see co-pending application of Lohman et al., filed concurrently herewith entitled Methods of Amplifying and Sequencing Nucleic Acids” U.S. Ser. No. 60/476,592 filed Jun. 6, 2003). Multiple batches of 70,000 beads were sequenced and the data were listed in Table 6, below. TABLE 6 Alignment Inferred Error Alignments Read Tolerance None Single Multiple Unique Coverage Error 0% 47916 1560 1110 54.98% 0.00% 5% 46026 3450 2357 83.16% 1.88% 10% 43474 6001 1 3742 95.64% 4.36% This table shows the results obtained from BLAST analysis comparing the sequences obtained from the pyrophosphate sequencer against Adenovirus sequence. The first column shows the error tolerance used in the BLAST program. The last column shows the real error as determined by direct comparison to the known sequence. Bead Emulsion PCR for Double Ended Sequencing Example 11 Template Quality Control As indicated previously, the success of the Emulsion PCR reaction was found to be related to the quality of the single stranded template species. Accordingly, the quality of the template material was assessed with two separate quality controls before initiating the Emulsion PCR protocol. First, an aliquot of the single-stranded template was run on the 2100 BioAnalyzer (Agilient). An RNA Pico Chip was used to verify that the sample included a heterogeneous population of fragments, ranging in size from approximately 200 to 500 bases. Second, the library was quantitated using the RiboGreen fluorescence assay on a Bio-Tek FL600 plate fluorometer. Samples determined to have DNA concentrations below 5 ng/μl were deemed too dilute for use. Example 12 DNA Capture Bead Synthesis Packed beads from a 1 mL N-hydroxysuccinimide ester (NHS)-activated Sepharose HP affinity column (Amersham Biosciences, Piscataway, N.J.) were removed from the column. The 30-25 μm size beads were selected by serial passage through 30 and 25 μm pore filter mesh sections (Sefar America, Depew, N.Y., USA). Beads that passed through the first filter, but were retained by the second were collected and activated as described in the product literature (Amersham Pharmacia Protocol # 71700600AP). Two different amine-labeled HEG (hexaethyleneglycol) long capture primers were obtained, corresponding to the 5′ end of the sense and antisense strand of the template to be amplified, (5′-Amine-3 HEG spacers gcttacctgaccgacctctgcctatcccctgttgcgtgtc-3′; SEQ ID NO:12; and 5′-Amine-3 HEG spacers ccattccccagctcgtcttgccatctgttccctccctgtc-3′; SEQ ID NO: 13) (IDT Technologies, Coralville, Iowa, USA). The primers were designed to capture of both strands of the amplification products to allow double ended sequencing, i.e., sequencing the first and second strands of the amplification products. The capture primers were dissolved in 20 mM phosphate buffer, pH 8.0, to obtain a final concentration of 1 mM. Three microliters of each primer were bound to the sieved 30-25 μm beads. The beads were then stored in a bead storage buffer (50 mM Tris, 0.02% Tween and 0.02% sodium azide, pH 8). The beads were quantitated with a hemacytometer (Hausser Scientific, Horsham, Pa., USA) and stored at 4° C. until needed. Example 13 PCR Reaction Mix Preparation and Formulation As with any single molecule amplification technique, contamination of the reactions with foreign or residual amplicon from other experiments could interfere with a sequencing run. To reduce the possibility of contamination, the PCR reaction mix was prepared in a in a UV-treated laminar flow hood located in a PCR clean room. For each 600,000 bead emulsion PCR reaction, the following reagents were mixed in a 1.5 ml tube: 225 μl of reaction mixture (1× Platinum HiFi Buffer (Invitrogen)), 1 mM dNTPs, 2.5 mM MgSO4 (Invitrogen), 0.1% BSA, 0.01% Tween, 0.003 U/μl thermostable PPi-ase (NEB), 0.125 μM forward primer (5′-gcttacctgaccgacctctg-3′; SEQ ID NO:14) and 0.125 μM reverse primer (5′-ccattccccagctcgtcttg-3′; SEQ ID NO:15) (IDT Technologies, Coralville, Iowa, USA) and 0.2 U/μl Platinum Hi-Fi Taq Polymerase (Invitrogen). Twenty-five microliters of the reaction mixture was removed and stored in an individual 200 μl PCR tube for use as a negative control. Both the reaction mixture and negative controls were stored on ice until needed. Example 14 Binding Template Species to DNA Capture Beads Successful clonal DNA amplification for sequencing relates to the delivery of a controlled number of template species to each bead. For the experiments described herein below, the typical target template concentration was determined to be 0.5 template copies per capture bead. At this concentration, Poisson distribution dictates that 61% of the beads have no associated template, 30% have one species of template, and 9% have two or more template species. Delivery of excess species can result in the binding and subsequent amplification of a mixed population (2 or more species) on a single bead, preventing the generation of meaningful sequence data. However, delivery of too few species will result in fewer wells containing template (one species per bead), reducing the extent of sequencing coverage. Consequently, it was deemed that the single-stranded library template concentration was important. Template nucleic acid molecules were annealed to complimentary primers on the DNA capture beads by the following method, conducted in a UV-treated laminar flow hood. Six hundred thousand DNA capture beads suspended in bead storage buffer (see Example 9, above) were transferred to a 200 pt PCR tube. The tube was centrifuged in a benchtop mini centrifuge for 10 seconds, rotated 180°, and spun for an additional 10 seconds to ensure even pellet formation. The supernatant was removed, and the beads were washed with 200 μl of Annealing Buffer (20 mM Tris, pH 7.5 and 5 mM magnesium acetate). The tube was vortexed for 5 seconds to resuspend the beads, and the beads were pelleted as before. All but approximately 10 μl of the supernatant above the beads was removed, and an additional 200 μl of Annealing Buffer was added. The beads were again vortexed for 5 seconds, allowed to sit for 1 minute, and then pelleted as before. All but 10 μl of supernatant was discarded. Next, 1.5 μl of 300,000 molecules/μl template library was added to the beads. The tube was vortexed for 5 seconds to mix the contents, and the templates were annealed to the beads in a controlled denaturation/annealing program preformed in an MJ thermocycler. The program allowed incubation for 5 minutes at 80° C., followed by a decrease by 0.1° C./sec to 70° C., incubation for 1 minute at 70° C., decrease by 0.1° C./sec to 60° C., hold at 60° C. for 1 minute, decrease by 0.1° C./sec to 50° C., hold at 50° C. for 1 minute, decrease by 0.1° C./sec to 20° C., hold at 20° C. Following completion of the annealing process, the beads were removed from the thermocycler, centrifuged as before, and the Annealing Buffer was carefully decanted. The capture beads included on average 0.5 copy of single stranded template DNA bound to each bead, and were stored on ice until needed. Example 15 Emulsification The emulsification process creates a heat-stable water-in-oil emulsion containing 10,000 discrete PCR microreactors per microliter. This serves as a matrix for single molecule, clonal amplification of the individual molecules of the target library. The reaction mixture and DNA capture beads for a single reaction were emulsified in the following manner. In a UV-treated laminar flow hood, 200 μl of PCR solution (from Example 10) was added to the tube containing the 600,000 DNA capture beads (from Example 11). The beads were resuspended through repeated pipetting. After this, the PCR-bead mixture was incubated at room temperature for at least 2 minutes, allowing the beads to equilibrate with the PCR solution. At the same time, 450 μl of Emulsion Oil (4.5% (w:w) Span 80, 1% (w:w) Atlox 4912 (Uniqema, Del.) in light mineral oil (Sigma)) was aliquotted into a flat-topped 2 ml centrifuge tube (Dot Scientific) containing a sterile {fraction (1/4)} inch magnetic stir bar (Fischer). This tube was then placed in a custom-made plastic tube holding jig, which was then centered on a Fisher Isotemp digital stirring hotplate (Fisher Scientific) set to 450 RPM. The PCR-bead solution was vortexed for 15 seconds to resuspend the beads. The solution was then drawn into a 1 ml disposable plastic syringe (Benton-Dickenson) affixed with a plastic safety syringe needle (Henry Schein). The syringe was placed into a syringe pump (Cole-Parmer) modified with an aluminum base unit orienting the pump vertically rather than horizontally (FIG. 30). The tube with the emulsion oil was aligned on the stir plate so that it was centered below the plastic syringe needle and the magnetic stir bar was spinning properly. The syringe pump was set to dispense 0.6 ml at 5.5 ml/hr. The PCR-bead solution was added to the emulsion oil in a dropwise fashion. Care was taken to ensure that the droplets did not contact the side of the tube as they fell into the spinning oil. Once the emulsion was formed, great care was taken to minimize agitation of the emulsion during both the emulsification process and the post-emulsification aliquotting steps. It was found that vortexing, rapid pipetting, or excessive mixing could cause the emulsion to break, destroying the discrete microreactors. In forming the emulsion, the two solutions turned into a homogeneous milky white mixture with the viscosity of mayonnaise. The contents of the syringe were emptied into the spinning oil. Then, the emulsion tube was removed from the holding jig, and gently flicked with a forefinger until any residual oil layer at the top of the emulsion disappeared. The tube was replaced in the holding jig, and stirred with the magnetic stir bar for an additional minute. The stir bar was removed from the emulsion by running a magnetic retrieval tool along the outside of the tube, and the stir bar was discarded. Twenty microliters of the emulsion was taken from the middle of the tube using a P100 pipettor and placed on a microscope slide. The larger pipette tips were used to minimize shear forces. The emulsion was inspected at 50× magnification to ensure that it was comprised predominantly of single beads in 30 to 150 micron diameter microreactors of PCR solution in oil (FIG. 33). After visual examination, the emulsions were immediately amplified. Example 16 Amplification The emulsion was aliquotted into 7-8 separate PCR tubes. Each tube included approximately 75 μl of the emulsion. The tubes were sealed and placed in a MJ thermocycler along with the 25 μl negative control described above. The following cycle times were used: 1 cycle of incubation for 4 minutes at 94° C. (Hotstart Initiation), 30 cycles of incubation for 30 seconds at 94° C., and 150 seconds at 68° C. (Amplification), and 40 cycles of incubation for 30 seconds at 94° C., and 360 seconds at 68° C. (Hybridization and Extension). After completion of the PCR program, the tubes were removed and the emulsions were broken immediately or the reactions were stored at 1 0° C. for up to 16 hours prior to initiating the breaking process. Example 17 Breaking the Emulsion and Bead Recovery Following amplification, the emulstifications were examined for breakage (separation of the oil and water phases). Unbroken emulsions were combined into a single 1.5 ml microcentrifuge tube, while the occasional broken emulsion was discarded. As the emulsion samples were quite viscous, significant amounts remained in each PCR tube. The emulsion remaining in the tubes was recovered by adding 75 μl of mineral oil into each PCR tube and pipetting the mixture. This mixture was added to the 1.5 ml tube containing the bulk of the emulsified material. The 1.5 ml tube was then vortexed for 30 seconds. After this, the tube was centrifuged for 20 minutes in the benchtop microcentrifuge at 13.2K rpm (full speed). After centrifugation, the emulsion separated into two phases with a large white interface. The clear, upper oil phase was discarded, while the cloudy interface material was left in the tube. In a chemical fume hood, 1 ml hexanes was added to the lower phase and interface layer. The mixture was vortexed for 1 minute and centrifuged at full speed for 1 minute in a benchtop microcentrifuge. The top, oil/hexane phase was removed and discarded. After this, 1 ml of 80% Ethanol/1× Annealing Buffer was added to the remaining aqueous phase, interface, and beads. This mixture was vortexed for 1 minute or until the white material from the interface was dissolved. The sample was then centrifuged in a benchtop microcentrifuge for 1 minute at full speed. The tube was rotated 180 degrees, and spun again for an additional minute. The supernatant was then carefully removed without disturbing the bead pellet. The white bead pellet was washed twice with 1 ml Annealing Buffer containing 0.1% Tween 20. The wash solution was discarded and the beads were pelleted after each wash as described above. The pellet was washed with 1 ml Picopure water. The beads were pelleted with the centrifuge-rotate-centrifuge method used previously. The aqueous phase was carefully removed. The beads were then washed with 1 ml of 1 mM EDTA as before, except that the beads were briefly vortexed at a medium setting for 2 seconds prior to pelleting and supernatant removal. Amplified DNA, immobilized on the capture beads, was treated to obtain single stranded DNA. The second strand was removed by incubation in a basic melt solution. One ml of Melt Solution (0.125 M NaOH, 0.2 M NaCl) was subsequently added to the beads. The pellet was resuspended by vortexing at a medium setting for 2 seconds, and the tube placed in a Thermolyne LabQuake tube roller for 3 minutes. The beads were then pelleted as above, and the supernatant was carefully removed and discarded. The residual Melt solution was neutralized by the addition of 1 ml Annealing Buffer. After this, the beads were vortexed at medium speed for 2 seconds. The beads were pelleted, and the supernatant was removed as before. The Annealing Buffer wash was repeated, except that only 800 μl of the Annealing Buffer was removed after centrifugation. The beads and remaining Annealing Buffer were transferred to a 0.2 ml PCR tube. The beads were used immediately or stored at 4° C. for up to 48 hours before continuing on to the enrichment process. Example 18 Optional Bead Enrichment The bead mass included beads with amplified, immobilized DNA strands, and empty or null beads. As mentioned previously, it was calculated that 61% of the beads lacked template DNA during the amplification process. Enrichment was used to selectively isolate beads with template DNA, thereby maximizing sequencing efficiency. The enrichment process is described in detail below. The single stranded beads from Example 14 were pelleted with the centrifuge-rotate-centrifuge method, and as much supernatant as possible was removed without disturbing the beads. Fifteen microliters of Annealing Buffer were added to the beads, followed by 2 μl of 100 μM biotinylated, 40 base enrichment primer (5′-Biotin-tetra-ethyleneglycol spacers ccattccccagctcgtcttgccatctgttccctccctgtctcag-3′; SEQ ID NO: 16). The primer was complimentary to the combined amplification and sequencing sites (each 20 bases in length) on the 3′ end of the bead-immobilized template. The solution was mixed by vortexing at a medium setting for 2 seconds, and the enrichment primers were annealed to the immobilized DNA strands using a controlled denaturation/annealing program in an MJ thermocycler. The program consisted of the following cycle times and temperatures: incubation for 30 seconds at 65° C., decrease by 0.1° C./sec to 58° C., incubation for 90 seconds at 58° C., and hold at 10° C. While the primers were annealing, Dynal MyOne™ streptavidin beads were resuspend by gentle swirling. Next, 20 μl of the MyOne™ beads were added to a 1.5 ml microcentrifuge tube containing 1 ml of Enhancing fluid (2 M NaCl, 10 mM Tris-HCl, 1 mM EDTA, pH 7.5). The MyOne bead mixture was vortexed for 5 seconds, and the tube was placed in a Dynal MPC-S magnet. The paramagnetic beads were pelleted against the side of the microcentrifuge tube. The supernatant was carefully removed and discarded without disturbing the MyOne™ beads. The tube was removed from the magnet, and 100 μl of enhancing fluid was added. The tube was vortexed for 3 seconds to resuspend the beads, and stored on ice until needed. Upon completion of the annealing program, 100 μl of annealing buffer was added to the PCR tube containing the DNA capture beads and enrichment primer. The tube vortexed for 5 seconds, and the contents were transferred to a fresh 1.5 ml microcentrifuge tube. The PCR tube in which the enrichment primer was annealed to the capture beads was washed once with 200 μl of annealing buffer, and the wash solution was added to the 1.5 ml tube. The beads were washed three times with 1 ml of annealing buffer, vortexed for 2 seconds, and pelleted as before. The supernatant was carefully removed. After the third wash, the beads were washed twice with 1 ml of ice cold Enhancing fluid. The beads were vortexed, pelleted, and the supernatant was removed as before. The beads were resuspended in 150 μl ice cold Enhancing fluid and the bead solution was added to the washed MyOne™ beads. The bead mixture was vortexed for 3 seconds and incubated at room temperature for 3 minutes on a LabQuake tube roller. The streptavidin-coated MyOne™ beads were bound to the biotinylated enrichment primers annealed to immobilized templates on the DNA capture beads. The beads were then centrifuged at 2,000 RPM for 3 minutes, after which the beads were vortexed with 2 second pulses until resuspended. The resuspended beads were placed on ice for 5 minutes. Following this, 500 μl of cold Enhancing fluid was added to the beads and the tube was inserted into a Dynal MPC-S magnet. The beads were left undisturbed for 60 seconds to allow pelleting against the magnet. After this, the supernatant with excess MyOne™ and null DNA capture beads was carefully removed and discarded. The tube was removed from the MPC-S magnet, and 1 ml of cold enhancing fluid added to the beads. The beads were resuspended with gentle finger flicking. It was important not to vortex the beads at this time, as forceful mixing could break the link between the MyOne™ and DNA capture beads. The beads were returned to the magnet, and the supernatant removed. This wash was repeated three additional times to ensure removal of all null capture beads. To remove the annealed enrichment primers and MyOne™ beads, the DNA capture beads were resuspended in 400 μl of melting solution, vortexed for 5 seconds, and pelleted with the magnet. The supernatant with the enriched beads was transferred to a separate 1.5 ml microcentrifuge tube. For maximum recovery of the enriched beads, a second 400 μl aliquot of melting solution was added to the tube containing the MyOne™ beads. The beads were vortexed and pelleted as before. The supernatant from the second wash was removed and combined with the first bolus of enriched beads. The tube of spent MyOne™ beads was discarded. The microcentrifuge tube of enriched DNA capture beads was placed on the Dynal MPC-S magnet to pellet any residual MyOne™ beads. The enriched beads in the supernatant were transferred to a second 1.5 ml microcentrifuge tube and centrifuged. The supernatant was removed, and the beads were washed 3 times with 1 ml of annealing buffer to neutralize the residual melting solution. After the third wash, 800 μl of the supernatant was removed, and the remaining beads and solution were transferred to a 0.2 ml PCR tube. The enriched beads were centrifuged at 2,000 RPM for 3 minutes and the supernatant decanted. Next, 20 μl of annealing buffer and 3 μl of two different 100 μM sequencing primers (5′-ccatctgttccctccctgtc-3′; SEQ ID NO: 17; and 5′-cctatcccctgttgcgtgtc-3′ phosphate; SEQ ID NO: 18) were added. The tube was vortexed for 5 seconds, and placed in an MJ thermocycler for the following 4-stage annealing program: incubation for 5 minutes at 65° C., decrease by 0.1° C./sec to 50° C., incubation for 1 minute at 50° C., decrease by 0.1° C./sec to 40° C., hold at 40° C. for 1 minute, decrease by 0.1° C./sec to 15° C., and hold at 15° C. Upon completion of the annealing program, the beads were removed from thermocycler and pelleted by centrifugation for 10 seconds. The tube was rotated 180°, and spun for an additional 10 seconds. The supernatant was decanted and discarded, and 200 μl of annealing buffer was added to the tube. The beads were resuspended with a 5 second vortex, and pelleted as before. The supernatant was removed, and the beads resuspended in 100 μl annealing buffer. At this point, the beads were quantitated with a Multisizer 3 Coulter Counter (Beckman Coulter). Beads were stored at 4° C. and were stable for at least 1 week. Example 19 Double Strand Sequencing For double strand sequencing, two different sequencing primers are used; an unmodified primer MMP7A and a 3′ phosphorylated primer MMP2 Bp. There are multiple steps in the process. This process is shown schematically in FIG. 38. 1. First Strand Sequencing. Sequencing of the first strand involves extension of the unmodified primer by a DNA polymerase through sequential addition of nucleotides for a predetermined number of cycles. 2. CAPPING: The first strand sequencing was terminated by flowing a Capping Buffer containing 25 mM Tricine, 5 mM Mangesium acetate, 1 mM DTT, 0.4 mg/ml PVP, 0.1 mg/ml BSA, 0.01% Tween and 2 μM of each dideoxynucleotides and 2 μM of each deoxynucleotide. 3. CLEAN: The residual deoxynucleotides and dideoxynucleotides was removed by flowing in Apyrase Buffer containing 25 mM Tricine, 5 mM Magnesium acetate, 1 mM DTT, 0.4 mg/ml PVP, 0.1 mg/ml BSA, 0.01% Tween and 8.5 units/L of Apyrase. 4. CUTTING: The second blocked primer was unblocked by removing the phosphate group from the 3′ end of the modified 3′ phosphorylated primer by flowing a Cutting buffer containing 5 units/ml of Calf intestinal phosphatases. 5. CONTINUE: The second unblocked primer was activated by addition of polymerase by flowing 1000 units/ml of DNA polymerases to capture all the available primer sites. 6. Second Strand Sequencing: Sequencing of the second strand by a DNA polymerase through sequential addition of nucleotides for a predetermined number of cycles. Using the methods described above, the genomic DNA of Staphylococcus aureus was sequenced. The results are presented in FIG. 39. A total of 31,785 reads were obtained based on 15770 reads of the first strand and 16015 reads of the second strand. Of these, a total of 11,799 reads were paired and 8187 reads were unpaired obtaining a total coverage of 38%. Read lengths ranged from 60 to 130 with an average of 95+/−9 bases (FIG. 40). The distribution of genome span and the number of wells of each genome span is shown in FIG. 41. Representative alignment strings, from this genomic sequencing, are shown in FIG. 42. Example 20 Template PCR 30 micron NHS Sepharose beads were coupled with 1 mM of each of the following primers: MMP1A: cgtttcccctgtgtgccttg (SEQ ID NO:19) MMP1B: ccatctgttgcgtgcgtgtc (SEQ ID NO:20) Drive-to-bead PCR was performed in a tube on the MJ thermocycler by adding 50 μl of washed primer-coupled beads to a PCR master mix at a one-to-one volume-to-volume ratio. The PCR master mixture included: 1×PCR buffer; 1 mM of each dNTP; 0.625 μM primer MMP1A; 0.625 μM primer MMP1B; 1 μl of 1 unit/μl Hi Fi Taq (Invitrogen, San Diego, Calif.); and ˜5-10 ng Template DNA (the DNA to be sequenced). The PCR reaction was performed by programming the MJ thermocycler for the following: incubation at 94° C. for 3 minutes; 39 cycles of incubation at 94° C. for 30 seconds, 58° C. for 30 seconds, 68° C. for 30 seconds; followed by incubation at 94° C. for 30 seconds and 58° C. for 10 minutes; 10 cycles of incubation at 94° C. for 30 seconds, 58° C. for 30 seconds, 68° C. for 30 seconds; and storage at 10° C. Example 21 Template DNA Preparation and Annealing Sequencing Primer The beads from Example 1 were washed two times with distilled water; washed once with 1 mM EDTA, and incubated with 0.125 M NaOH for 5 minutes. This removed the DNA strands not linked to the beads. Then, the beads were washed once with 50 mM Tris Acetate buffer, and twice with Annealing Buffer: 200 mM Tris-Acetate, 50 mM Mg Acetate, pH 7.5. Next, 500 pmoles of Sequencing Primer MMP7A (ccatctgttccctccctgtc; SEQ ID NO:21) and MMP2B-phos (cctatcccctgttgcgtgtc; SEQ ID NO:22) were added to the beads. The primers were annealed with the following program on the MJ thermocycler: incubation at 60° C. for 5 minutes; temperature drop of 0.1 degree per second to 50° C.; incubation at 50° C. for 5 minutes; temperature drop of 0.1 degree per second to 4° C.; incubation at 40° C. for 5 minutes; temperature drop of 0.1 degree per second to 10° C. The template was then sequenced using standard pyrophosphate sequencing. Example 22 Sequencing and Stopping of the First Strand The beads were spun into a 55 μm PicoTiter plate (PTP) at 3000 rpm for 10 minutes. The PTP was placed on a rig and run using de novo sequencing for a predetermined number of cycles. The sequencing was stopped by capping the first strand. The first strand was capped by adding 100 μl of 1×AB (50 mM Mg Acetate, 250 mM Tricine), 1000 unit/ml BST polymerase, 0.4 mg/ml single strand DNA binding protein, 1 mM DTT, 0.4 mg/ml PVP (Polyvinyl Pyrolidone), 10 μM of each ddNTP, and 2.5 μM of each dNTP. Apyrase was then flowed over in order to remove excess nucleotides by adding 1×AB, 0.4 mg/ml PVP, 1 mM DTT, 0.1 mg/ml BSA, 0.125 units/ml apyrase, incubated for 20 minutes. Example 23 Preparation of Second Strand for Sequencing The second strand was unblocked by adding 100 μl of 1×AB, 0.1 unit per ml poly nucleotide kinase, 5 mM DTT. The resultant template was sequenced using standard pyrophosphate sequencing (described, e.g., in U.S. Pat. Nos. 6,274,320, 6258,568 and 6,210,891, incorporated herein by reference). The results of the sequencing method can be seen in FIG. 10F where a fragment of 174 bp was sequenced on both ends using pyrophosphate sequencing and the methods described in these examples. Example 24 Sequence Analysis of Nucleic Acid on a Picotiter Plate The picotiter plate containing amplified nucleic acids as described in Example 2 is placed in a perfusion chamber. Then sulfurylase, apyrase, and luciferase are delivered to the picotiter plate. The sequencing primer primes DNA synthesis extending into the insert suspected of having a polymorphism, as shown in FIGS. 11A-11D. The sequencing primer is first extended by delivering into the perfusion chamber, in succession, a wash solution, a DNA polymerase, and one of dTTP, dGTP, dCTP, or at thio dATP (a dATP analog). The sulfurylase, luciferase, and apyrase, attached to the termini convert any PPi liberated as part of the sequencing reaction to detectable light. The apyrase present degrades any unreacted dNTP. Light is typically allowed to collect for 3 seconds (although 1-100, e.g., 2-10 seconds is also suitable) by a CCD camera linked to the fiber imaging bundle, after which additional wash solution is added to the perfusion chamber to remove excess nucleotides and byproducts. The next nucleotide is then added, along with polymerase, thereby repeating the cycle. During the wash the collected light image is transferred from the CCD camera to a computer. Light emission is analyzed by the computer and used to determine whether the corresponding dNTP has been incorporated into the extended sequence primer. Addition of dNTPs and pyrophosphate sequencing reagents is repeated until the sequence of the insert region containing the suspected polymorphism is obtained. Example 25 On Picotiter Plate PCR Amplification Picotiter plate Preparation: In a further embodiment, the single stranded library attached to beads are distributed directly onto the picotiter plate and then the nucleic acid template on each bead is amplified (using PCR or other known amplification technology) to generate sufficient copy number of the template that will generate detectable signal in the pyrophosphate-based sequencing methods disclosed herein. Example 26 Sequence Analysis of Nucleic Acid on a PTP Reagents used for sequence analysis and as controls were the four nucleotides and 0.1 μM Pyrophosphate (PPi) were made in substrate solution. Substrate solution refers to a mixture of 300 μM Luciferin and 4 μM adenosine 5′-phosphosulfate, APS, which are the substrates for the cascade of reactions involving PPi, Luciferase and Sulfurylase. The substrate was made in assay buffer. The concentration of PPi used to test the enzymes and determine the background levels of reagents passing through the chamber was 0.1 μM. The concentration of the nucleotides, dTTP, dGTP, dCTP was 6.5 μM and that of αdATP was 50 μM. Each of the nucleotides was mixed with DNA polymerase, Klenow at a concentration of 100 U/mL. The PTP was placed in the flow chamber of the embodied instrument, and the flow chamber was attached to the faceplate of the CCD camera. The PTP was washed by flowing substrate (3 ml per min, 2 min) through the chamber. After this, a sequence of reagents was flown through the chamber by the pump connected to an actuator, which was programmed to switch positions, which had tubes inserted in the different reagents. The sequence of reagents, flow rates, and flow times were determined. The camera was set up in a fast acquisition mode, with exposure time=2.5 s. The signal output from the pad was determined as the average of counts on all the pixels within the pad. The frame number was equivalent to the time passed during the experiment. Graphing was used to represent the flow of the different reagents. Example 27 Plate-Based Platform for Picoliterscale PCR Reactions Materials and Methods Unless otherwise indicated, all common laboratory chemicals were purchased either from Sigma (Sigma-Aldrich Corporation, St. Louis, Mich.) or Fisher (Fisher Scientific, Pittsburgh, Pa.). The PicoTiterPlates™ (25×75×2 mm) were manufactured by anisotropic etching of fiber optic faceplates in a manner similar to that previously described (Pantano, P. and Walt, D. R., Chemistry of Materials 1996, 8, 2832-2835). Plates were etched in three different microwell depths, 26, 50 and 76 μm. Microwell center-to-center pitch was 50 μm, and well diameters ranged between 39 and 44 μm (See FIG. 14), with a calculated well density of 480 wells/mm2. Solid-phase immobilization of oligonucleotide primers: Packed beads from a 1 ml NHS-activated Sepharose HP affinity column (Amersham Biosciences, Piscataway, N.J.) were removed from the column and activated according to the manufacturer's instructions (Amersham Pharmacia Protocol # 71700600AP). Twenty-five microliters of a 1 mM amine-labeled HEG capture primer (5′-Amine-3 hexaethyleneglycol spacers ccatctgttgcgtgcgtgtc-3′; SEQ ID NO:23) (IDT Technologies, Coralville, Iowa) in 20 mM phosphate buffer pH 8.0 were bound to the beads. After this, 36 to 25 μm beads were selected by serial passage through 36 and 25 μm pore filter mesh sections (Sefar America, Depew, N.Y.). DNA capture beads that passed through the first filter, but were retained by the second were collected in bead storage buffer (50 mM Tris, 0.02% Tween, 0.02% Sodium Azide, pH 8), quantitated with a hemacytometer (Hausser Scientific, Horsham, Pa.) and stored at 4° C. until needed. Generation of test DNA fragments: Amplification test fragments were derived from a commercially available adenovirus serotype 5 vector, pAdEasy (Stratagene, La Jolla, Calif.). Fragments were amplified using bipartite PCR primers, the 5′ end of which contained a 20 base amplification region, and a 20 base 3′ section, complementary to a specific region of the adenovirus genome. Using these primers, two fragments were amplified from the 12933-13070 and 5659-5767 position of the adenovirus genome and assigned labels Fragment A and Fragment B, respectively. The sequences for the forward and reverse primers for Fragment A was as follows. A slash (/) denotes the separation between the two regions of the primer: forward (5′-cgtttcccctgtgtgccttg/catcttgtccactaggctct-3′; SEQ ID NO:24-SEQ ID NO:25), and reverse (5′-ccatctgttgcgtgcgtgtc/accagcactcgcaccacc-3′; SEQ ID NO:26-SEQ ID NO:27). The primers for the Fragment B included: forward (5′-cgtttcccctgtgtgccttg/tacctctccgcgtaggcg-3′; SEQ ID NO:28-SEQ ID NO:29), and reverse (5′-ccatctgttgcgtgcgtgtc/ccccggacgagacgcag-3′; SEQ ID NO:30-SEQ ID NO:31). Reaction conditions included 50 mM KCl, 10 mM Tris-HCl (pH 9.0), 0.1% Triton X-100, 2.5 mM MgCl2, 0.2 mM dNTP, 1 μM each forward and reverse primer, 0.1 U/μl Taq (Promega, Madison, Wis.) and 50 nmol template DNA. Both templates were amplified with a PCR program that include 35 cycles of incubation at 94° C. for 30 seconds, 56° C. for 30 seconds, and 72° C. for 90 seconds. With PCR primers, the total length of the amplified fragments was 178 bp for Fragment A and 148 bp for Fragment B. To generate fluorescent probes, biotinylated double stranded fluorescent probes were prepared by PCR amplification from the pAdEasy vector as described above. However, the primer sequences were changed to prevent hybridization between the test fragment and probe primer regions. In addition, the reverse primers for both fragments utilized a 5′biotin followed by 3× hexaethyleneglycol spacers to permit product immobilization to beads prior to elution of the single stranded probe. The sequence for the forward primer for the fluorescent Fragment A probe was as follows. A slash (/) denotes the separation between the two regions of the primer (5′-atctctgcctactaaccatgaag/catcttgtccactaggctct-3′; SEQ ID NO:32-SEQ ID NO:33). The sequence for the reverse primer was 5′-biotin-3×hexaethyleneglycol spacers-gtttctctccagcctctcaccga/accagcactcgcaccacc-3′; SEQ ID NO:34-SEQ ID NO:35. The primers for the Fragment B were as follows: forward (5′-atctctgcctactaaccatgaag/tacctctccgcgtaggcg-3′; SEQ ID NO:36-SEQ ID NO:37), and reverse (5′-biotin-3×hexaethyleneglycol spacers-gtttctctccagcctctcaccga/ccccggacgagacgcag-3′; SEQ ID NO:38-SEQ ID NO:39). Fluorescent moieties were incorporated through the nucleotide mixture. This included 0.2 mM dATP/dGTP/dCTP, 0.15 mM TTP and 0.05 mM Alexa Fluor 488-dUTP (Molecular Probes, Eugene, Oreg.) for Fragment A. Alternately, 0.2 mM dATP/dGTP/TTP, 0.15 mM dCTP and 0.05 mM Alexa Fluor 647-dCTP (Molecular Probes, Eugene, Oreg.) was used for amplifying Fragment B. The fluorescent products were purified with a QIAquick PCR Purification Kit (Qiagen, Valencia, Calif.). The biotinylated DNA was subsequently bound to 100 μl (approximately 8.1 million) Streptavidin Sepharose High Performance beads (Amersham Biosciences) in 1× binding wash (5 mM Tris HCl pH 7.5, 1 M NaCl, 0.5 mM EDTA, 0.05% Tween-20) for 2 hours at room temperature. After incubation, the beads were washed three times in TE buffer (10 mM Tris, 1 mM EDTA, pH 8.0) and incubated with 250 μl melt solution (0.125 N NaOH/0.1 M NaCl) for 2 minutes, releasing the single stranded probe from the beads. Beads were pelleted with brief centrifugation in a benchtop centrifuge and the supernatant was neutralized in 1.25 ml buffer PB (Qiagen) with 1.9 μl glacial acetic acid. This mixture was repurified on a QiaQuick column (Qiagen), and the concentration of the purified probe was determined by TaqMan quantification using the BioRad iCycler (BioRad, Hercules, Calif.). Solution-phase PTPCR was performed as follows. The PCR reaction mixture was loaded into individual wells of a single 14 mm×43 mm PicoTiterPlate™. For this, 500 μl of PCR reaction mixture (1× Platinum HiFi Buffer (Invitrogen, Carlsbad, Calif.), 2.5 mM MgSO4, 0.5% BSA, 1 mM dNTPs (MBI Fermentas, Hanover, Md.), 1 μM forward (5′-cgtttcccctgtgtgccttg-3′; SEQ ID NO:40) and reverse (5′-ccatctgttgcgtgcgtgtc-3′; SEQ ID NO:41) primers, 0.05% Tween-80, 1 U/μl Platinum High Fidelity DNA Polymerase (Invitrogen), 0.003 U/μl Thermostable Pyrophosphatase (USB, Cleveland, Ohio), and a calculated 5 copies of Fragment B template per well) were combined in a 1.5 ml microcentrifuge tube. The tube was vortexed thoroughly and stored on ice until the PicoTiterPlate™ loading cartridge was assembled. The in-house PicoTiterPlate™ loading cartridge was attached to the PicoTiterPlate™ with two plastic clips, seating the silicon cartridge gasket firmly on the PicoTiterPlate™ surface (see FIG. 20). The PCR reaction mix was drawn into a 1 ml disposable syringe, and the mouth of the syringe inserted into the input tube of the loading cartridge. The loading cartridge was placed on end, so that the input port was oriented at the bottom of cartridge, and the PCR mix was slowly loaded into the chamber. While loading, inspected through the transparent back of the PicoTiterPlate™ to ensure even, bubble-free delivery. After loading, the PCR mixture was allowed to incubate for 5 minutes, at which time the reaction mixture was withdrawn from the PicoTiterPlate™ loading cartridge. The PicoTiterPlate™ was removed from the loading cartridge, and immediately placed in the amplification chamber (see FIG. 21). The PicoTiterPlate™ surface was covered with a 0.25 mm thick Silpad A-2000 silicon sheet (The Bergquist Company, Chanhassen, Minn.). On top of this was placed a 25 mm×75 mm standard glass microscope slide (Fisher). A closed cell foam insulation pad (Wicks Aircraft Supply, Highland, Ill.) was placed on top of the microscope slide. An aluminum lid was attached to the base of the chamber by six 25 mm bolts sealed the amplification chamber. Once sealed, the amplification chamber was placed on a Thermocycler MJ PTC 225 Tetrad (MJ Research, Waltham, Mass.) equipped with Flat Block Alpha Units. The amplification program included incubation for 3 minutes at 94° C. (Hotstart Initiation) followed by 40 cycles of incubation for 12 seconds at 94° C., 12 seconds at 58° C., 12 seconds at 68° C., with a 10° C. final hold. After completion of the PCR program, the PicoTiterPlate™ was removed from the amplification chamber, and the loading cartridge was reattached. A disposable syringe was used to fill the cartridge chamber with 1 ml of H2O, and allowed to incubate for 20 minutes 10° C. at room temperature. After the incubation was completed, the recovery solution was withdrawn from the loading cartridge and transferred to a 1.5 ml microcentrifuge tube. PCR product was quantitated using an iCycler RealTime PCR unit (BioRad) and FAM-labeled reporter probes (Epoch Biosciences, Bothell, Wash.). The TaqMan Universal PCR MasterMix (Applied Biosystems, Foster City, Calif.) was combined with 0.3 μM forward and reverse primers, 0.15 μM FAM-labeled probe, and 27 μl of the reaction mix added to each well of a 96 well PCR plate. Purified fragments were used to create a standard curve (six standards ranging from 1×109 to 1×104 molecules per well), which was run in triplicate. The PCR amplification was run with the following parameters: incubation for 5 minutes at 94° C. (hotstart initiation), 60 cycles of incubation for 15 seconds at 94° C., 45 seconds at 68° C., with a final hold at 4° C. Data was analyzed using the iCycler Optical Systems Software Version 2.3 (BioRad), and the PCR yield was quantitated using the iCycler data and Microsoft Excel (Microsoft, Redmond, Wash.). Solid-phase PTPCR was performed similarly to solution phase PTPCR, except that DNA capture beads were loaded into the PicoTiterPlate™ wells prior to amplification by centrifugation as described below. In addition, the PCR mixture was loaded into the microwells after the bead deposition was completed. To facilitate retention of the capture beads during wash steps, the solid phase experiments utilized 50 μm deep PicoTiterPlate™s. The PicoTiterPlate™ was placed in an in-house built plexiglass bead loading jig. This was similar to the PicoTiterPlate™ loading jig described in FIG. 20, except that the PicoTiterPlate™ was sandwiched between a bottom Plexiglas plate and a jig top plate, containing inlet and outlet ports, and sealed via a silicon gasket with plastic screws. Template DNA was preannealed to the DNA capture beads at 5 template copies per bead by incubation at 80° C. for 3 minutes, after which beads were allowed to cool to room temperature for 15 minutes. The beads were then spun into the PicoTiterPlate™ wells prior to loading the PCR reaction mixture. Bead Loading Buffer (450 μl; 1× Platinum HiFi PCR buffer (Invitrogen), 0.02% Tween-80) containing one hundred thousand Sepharose DNA capture beads (approximately 1 bead per 3 PicoTiterPlate™ wells) were injected by pipette into the jig through one of the inlet ports. Each inlet hole was then sealed with a circular adhesive pad (3M VHS, St. Paul, Minn.). The jig held the PicoTiterPlate™ with its wells facing up and covered with the bead suspension. This was centrifuged at 2000 rpm for 5 minutes at room temperature in an Allegra 6 centrifuge (Beckman Coulter, Fullerton, Calif.) using a Microtiter Rotor. After centrifugation, the PicoTiterPlate™ was removed from the jig. The PCR reaction mix was loaded onto the PicoTiterPlate™ as described for solution phase PCR. However, the solid-phase PCR mixture omitted template since the template was preannealed to the DNA capture beads. The solid-phase PCR amplification program included additional hybridization/extension cycles to compensate for the slower kinetics of the immobilized primer. The program included incubation for 3 minutes at 94° C. for hotstart initiation, 40 cycles of incubation for 12 seconds at 94° C., 12 seconds at 58° C., 12 seconds at 68° C., followed by 10 cycles of incubation for 12 seconds at 94° C., 10 minutes at 68° C. for hybridization and extension, with a 10° C. final hold. Upon completion of the PCR program, the PicoTiterPlate™ was removed from the amplification chamber, and washed with 1 ml H2O as described for solution phase PCR. The PicoTiterPlate™ was then prepared for hybridization detection of immobilized PCR product. Hybridization was performed with fluorescently labeled probes as follows. After PTPCR was complete, the strand complementary to the immobilized strand was removed. For this, the whole PicoTiterPlate™ was incubated in 0.125 M NaOH for 8 minutes at room temperature. This solution was neutralized by two 5 minute washes in 50 ml of 20 mM Tris-acetate pH 7.5. The PicoTiterPlate™ was then placed in a custom-made 800 μl hybridization chamber, and blocked with hybridization buffer (3.5×SSC, 3.0% SDS, 20×SSC buffer is 3 M NaCl; 0.3 M Na3-citrate) at 65° C. for 30 minutes. The contents of the chamber were replaced with fresh hybridization buffer containing the probes: 20 nM fluorescent Fragment A (Alexa-488) and Fragment B (Alexa-647). The probes were allowed to hybridize to their targets. Incubation was carried out at 65° C. for 4 hours while shaking at 200 RPM on an orbital shaker (Barnstead International, Dubuque, Iowa). After hybridization, the PicoTiterPlate™ was washed with 2×SSC, 0.1% SDS for 15 minutes at 37° C., followed by a 15 minute wash in 1×SSC at 37° C., with two final 15 minute washes in 0.2×SSC at 37° C. Following post-hybridization washing, the PicoTiterPlates™ were air dried and placed in a FLA-8000 Fluorescent Image Analyzer (Fujifilm Medical Systems USA, Stamford, Conn.) and scanned at the 635 and 473 nm wavelength. The resulting 16-bit tiff images were imported into Genepix 4.0 (Axon Instruments, Union City, Calif.). A block of 100 analysis features was drawn over the area of interest and the 635 and 473 fluorescence intensities were recorded for each feature. Data was then exported to Microsoft Excel for further analysis. Control beads were prepared as follows. Biotinylated test templates A and B were prepared by PCR amplification from the pAdEasy vector, purified, immobilized on Streptavidin Sepharose High Performance beads and strand separated as described under “Preparation of Fluorescent Probes”. However, fluorescently labeled dNTPs were ommitted in the PCR reaction. Pelleted beads were washed 3 times with TE buffer and stored at 4° C. in TE until deposition onto the PicoTiterPlate™. Results Solution-phase amplification was demonstrated by loading PicoTiterPlates with PCR master mix containing a calculated 5 template copies per PicoTiterPlate™ well. Reactions were run in duplicate in PicoTiterPlates with 26, 50 and 76 μm deep wells. Forty cycles of PTPCR amplification were performed as described in Material and Methods. Additives were incorporated to prevent the deleterious surface effects routinely reported with silica reaction vessels (Kalinina, O., et al., Nucleic Acids Res. 1997, 25, 1999-2004; Wittwer, C. T. and Garling, D. J., Biotechniques 1991, 10, 76-83; Taylor, T. B., et al., Nucleic Acids Res. 1997, 25, 3164-3168). The inclusion of 0.5% BSA and 0.05% Tween-80 in the reaction mix was not only effective at reducing surface effects, it also facilitated amplification. Reducing the relative concentrations of either reagent had a negative effect on amplification. In addition, due to the polymerase-inactivating properties of silica surfaces (Taylor, T. B., et al., Nucleic Acids Res. 1997, 25, 3164-3168; Shoffner, M. A., Cheng, J., Hvichia, G. E., Kricka, L. J. and Wilding, P., Nucleic Acids Res. 1996, 24, 375-379), elevated Taq concentrations proved beneficial. Concentrations above 1 U/μl were optimum for enhancing amplicon yield. Following PTPCR, the solution from each PicoTiterPlate™ was recovered and triplicate samples of each solution were quantified by TaqMan assay. A standard curve of diluted template (linear from 1×109 to 104 molecules, r2=0.995) was used to determine the concentration of the amplified product. The number of molecules amplified per well was obtained by dividing the amount of amplified product by the total number of wells in a PicoTiterPlate™ (372,380). The amount of amplification per well was calculated by dividing this number by the initial template concentration per well. PTPCR amplification was successful in all of the PicoTiterPlate™, with yields ranging from 2.36×106 fold in the 39.5 pl wells to 1.28×109 fold in the 50 pl wells (See Table below). Average Final Well Fold Fold Product PicoTiterPlate Volume Amplification Amplification Conc. Depth [μm] [pl] N = 6 SD [M] 26 39.5 2.36E+06 1.02E+06 4.96E−07 50 76.0 1.28E+09 1.03E+09 1.40E−04 76 115.6 9.10E+08 4.95E+08 6.54E−05 The table shows PicoTiterPlate ™ PCR amplification as determined by TaqMan Assay. Values reflect triplicate measurements taken from duplicate PicoTiterPlates. (N = 6); SD = standard deviation. Yield was influenced by well volume. The concentration of final product obtained for the 50 μm deep wells (1.4×10−4 M) was significantly greater (p value for ANOVA=0.023) than that obtained in the 76 μm (6.54×10−5 M) deep wells, both were two orders of magnitude greater than the yield achieved in the 26 μm deep wells (4.96×10−7 M). The 50 μm deep microwell yield represented the optimal balancing of the costs and benefits associated with low-volume PCR. In this case, maximum elevation of the effective concentrations and low thermal mass of the reagents were obtained, but the surface to volume ratio was still low enough to prevent detrimental surface effects from significantly reducing amplification efficiency. The final concentration of PTPCR product obtained in each of the different well depths (4.96×10−7 to 1.4×10−4 M) exceeded the 10−8 M concentration typically reported as the maximum achievable before the PCR plateau effect occurs (Sardelli, A., Amplifications 1993, 9, 1-5). The higher effective concentration of primers and template molecules resulting from the low microwell volume increased the overall reaction efficiency and postponed the onset of the plateau phase until a higher molar yield was achieved. Alternatively, this effect was caused by the high concentration of Taq used in the PTPCR reactions, as elevated polymerase concentration has also been shown effective in delaying the plateau effect (Kainz, P., Biochim. Biophys. Acta 2000, 1494, 23-27; Collins, F. S., et al., Science 2003, 300, 286-290). The amplification efficiency over 40 cycles was 44.3, 68.9 and 67.5% for the 26, 50 and 76 μm deep wells respectively, providing a high final concentration of amplicons. The greatest yield was observed in the 50 μm deep wells. It should be recognized, however, that cycle number optimization was not conducted; similar amplification yields could likely have been achieved with far fewer cycles, thereby increasing the efficiency of the PTPCR amplification. The experimental strategy for clonal solid phase PTPCR, starting with a single effective copy of a single stranded DNA fragment, and finishing with a specific bead-immobilized DNA amplicon detected by fluorescent probe hybridization, is depicted in FIG. 22 and described in detail below: Stage 1: Each PicoTiterPlate™ well contains PCR reaction mix consisting of a single stranded template molecule (either single stranded and annealed to the DNA capture beads, as shown here, or free-floating in solution), Forward “F” (red) and Reverse “R” (blue) primers in solution, as well as R primers attached to a DNA capture bead. Solution phase primers are present in an 8:1 molar ratio, with the F primer in excess. Arrows indicate the 5′->3′ DNA orientation. Stage 2: The initial thermal cycle denatures the DNA template, allowing R primers in solution to bind to the complementary region on the template molecule. Thermostable polymerases initiate elongation at the primer site (dashed line), and in subsequent cycles, solution-phase exponential amplification ensues. Bead immobilized primers are not assumed to be major contributors to the amplification at this stage. Stage 3: Early Phase PCR. During early exponential amplification (1 to 10 cycles) both F and R primers amplify the template equally, despite an excess of F primers in solution. Stage 4: Mid Phase PCR. Between cycles 10 and 30, the R primers are depleted, halting exponential amplification. The reaction then enters an asymmetric amplification phase, and the amplicon population becomes increasingly dominated by F strands. Stage 5: Late Phase PCR. After 30 to 40 cycles, asymmetric amplification continues to increase the concentration of F strands in solution. Excess F strands, without R strand complements, begin to anneal to bead-immobilized R primers. Thermostable polymerases utilize the F strand as a template to synthesize an immobilized R strand of the amplicon. Stage 6: Final Phase PCR. Continued thermal cycling forces additional annealing to bead-bound primers. Solution phase amplification may be minimal at this stage, but concentration of immobilized R strands continues to increase. Stage 7: The non-immobilized, F strand, complementary to the immobilized R strand, is removed by alkali denaturation. The DNA capture beads are now populated by single stranded R strands of the amplicon. Stage 8: Fluorescently labeled probes (green bars) complementary to the R strand are annealed to the immobilized strand. Probes specific for particular strand sequences are labeled with unique fluorophores, resulting in a range of homogenous and heterogeneous fluorescent signals depending on the number of discrete templates amplified within a given PicoTiterPlate™ well. Initially, fluorescently labeled probe specificity was confirmed by binding biotinylated Fragment A or Fragment B test DNA fragments to streptavidin Sepharose beads, loading the beads into a 50 μm deep PicoTiterPlate™ by centrifugation and hybridizing a mixed population of fluorescently labeled probes for the Fragment A and Fragment B fragments. No mixed signals or nonspecific hybridizations were observed; the beads with the Fragment A product displayed the 488 nm signal, while the Fragment B beads exhibited the 635 nm signal (See FIGS. 23A and 23B). Close examination of FIGS. 23A and 23B reveals a few Fragment A beads in the Fragment B pad and vice versa. Given the purity of the signal displayed by these nomadic beads, it is likely that they are either the product of some cross contamination during the loading process, or were washed from one pad to the other during subsequent wash steps. As indicated in FIG. 23C, the fluorescent probes detected successful solid phase PTPCR amplification of both Fragment A and Fragment B templates. The signals generated by the hybridized probe depended on the relative efficiency of dye incorporation within the probes, the sensitivity of the reactions to unequal amounts of template DNA, as well as the total and relative amounts of amplified product present on each bead. In addition, it is likely that the amount of template generated and retained on the DNA capture beads varied from well to well, and the number of capture primers bound to each bead is also likely to vary due to bead size distribution. As a result, the non-normalized ratios generated by the probe hybridization should be seen as semi-qualitative rather than quantitative data. Nevertheless, the fluorescent signals generated by the hybridized probes ranged from a homogeneous Fragment B signal (red) to an equally homogenous Fragment A signal (green), with heterogeneous mixes of the two signals (degrees of yellow) evident as well. Due to the probe specificity displayed by the controls, as well as the sizeable number of homogenous red and green beads on the PicoTiterPlate™, it is unlikely that nonspecific probe hybridization caused the heterogeneous signals. The close proximity of homogenous beads of either template suggests it is unlikely that the heterogeneous beads resulted from amplicon leakage between wells during amplification; if intra-well cross-talk were responsible, one would expect to see heterogeneous beads located between homogenous beads of either template, and a generally patchy distribution of homogenous signals. Rather, it is likely that template molecules disassociated from their original bead and reannealed to new beads in the PicoTiterPlate™ loading mix prior to being spun into the microwells, or were washed from one bead to another as the PCR mix was applied to the PicoTiterPlate™. Regardless of the cause of the mixed template beads, the hybridization results show that PCR amplification in the PicoTiterPlate™ microwells can drive sufficient product to the DNA capture beads to enable fluorescent probe hybridization and detection. Discussion The results in this example demonstrate that PicoTiterPlate™-based PCR alleviates many factors associated with the DNA amplification process, such as high costs of reagents, large numbers of reactions, and lengthy reaction times, delivering another “evolutionary jump” in PCR technology. The microwells on a single PicoTiterPlate™ can function as up to 370,000 discrete reaction vessels achieving high yield (2.3×106 to 1.2×109 fold) amplification even at reaction volumes as low as 39.5 picoliters. As a result, throughput is increased, and the total reagent cost for PTPCR is reduced; the reaction volume contained in an entire 26 or 76 μm deep PicoTiterPlate™ is 15.3 and 43 μl, respectively. Increases in the size of the PicoTiterPlate™ can further increase the maximal throughput. For example, increasing the PicoTiterPlate™ dimensions to 40 mm×75 mm provides approximately 1.4×106 discrete reaction vessels, and a PicoTiterPlate™ possessing the same perimeter dimensions as a commercially available 96-well PCR plate (85.47 mm×127.81 mm) could contain as many as 5.24×106 wells. Solution phase PCR amplifications, regardless of the number and volume in which they are conducted, are of limited utility unless the product can be recovered easily and efficiently. Previous efforsts in parallel PCR (Nagai, H., et al., Anal. Chem. 2001, 73, 1043-1047) required evaporation of the liquid reaction mixture, leaving the amplicon dried to the walls of the microreactor, after which it could be recovered for further manipulations. The methodology disclosed herein avoids the problems of product recovery by including solid phase amplification, immobilizing the PCR product to a DNA capture bead. Thus, the product of a PicoTiterPlate™ microwell reaction is not 370,000 wells containing solution-phase PCR product, but up to 370,000 beads bound with immobilized PCR product. These PCR products are suitable for numerous solid-phase methods of nucleic acid interrogation including the potential capacity to support a massively parallel approach to sequencing whole genomes containing up to hundreds of millions of bases. The simplicity of the disclosed method would drastically reduce costs for sequencing and other applications now requiring robotics to maintain large-scale cloning and PCR. The disclosures of one or more embodiments of the invention are set forth in the accompanying description. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. Other features, objects, and advantages of the invention will be apparent from the description and from the claims. In the specification and the appended claims, the singular forms include plural referents unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Unless expressly stated otherwise, the techniques employed or contemplated herein are standard methodologies well known to one of ordinary skill in the art. The examples of embodiments are for illustration purposes only. All patents and publications cited in this specification are incorporated by reference. Example 28 Rig Sequencing Method Step 1: Preparation of pAdEasy PCR DNA Beads This proceedure was used for a 384-well plate PCR of Adenovirus clones. Streptavidin-Sepharose beads (12 mls) were prepared for binding PCR fragments by washing once with 2 M NaCl solution and resuspending in 288 mls of 2 M NaCl. The washed beads were transferred to fifteen 96-well plates at 200 μl of bead suspension/well. The PCR products (25 μl) were transferred to a 384-deep-well plate using a Tecan TeMo robot. To bind DNA to solid supports, 25 μl of bead suspension (15,000 beads) were added to each well of every 384-deep well plate using a Tecan TeMo robot and mixed. The final concentration of NaCl in the binding reaction was 1 M. The binding reaction was incubated with shaking at room temperature for 3 hr on a shaker. The contents of the microtiter plates were pooled by inverting the 384-well plates on to a reservoir and centrifuging at 1000 g in a Beckman Allegra benchtop centrifuge. The pooled beads were transferred into a 50 ml Falcon tube, centrifuged at 1000 g, and the supernatant was removed. Approximately a million beads (mobile solid support) were washed once with 100 μl of 2 M NaCl followed by two washes with distilled water (100 μl each). The washed beads were incubated in 300 μl melting reagent (0.1 M NaCl and 0.125 M NaOH) for 10 minutes in a rotator to remove the non-biotinylated DNA strand. The tube was centrifuged at maximum speed to pellet the beads and the melt solution was removed and discarded. The beads were washed with 100 μl of melt solution followed by three more washes with 1× Annealing buffer. After the washes, the beads were resuspended in 25 μl of 1× Annealing buffer. Primer P2 (500 pmoles) was added to the bead mixture and mixed. The bead mixture, in tubes, was placed into an automated incubator (PCR thermocycler in this case) with the following temperature profiles: incubation at 60° C. for 5 minutes, decrease 0.1° C./second down to 50° C., incubation at 50° C. for 5 minutes, decrease 0.1° C./second down to 40° C., incubation at 40° C. for 5 minutes, decrease 0.1° C./second down to 4° C., incubation at 4° C. forever. After annealing, the beads were washed carefully and resuspended in 200 μl of Bst DNA polymerase binding solution. Then, 10 μl aliquots (50,000 beads) of the bead suspension were processed for sequencing on the instrument described below. Step 2: Preparation of Control DNA Beads Six control DNA sequences TF 2, 7, 9, 10, 12 and 15 were cloned into pBluescript II KS+vector and plasmid DNA was used as template for PCR with one biotinylated primer for solid-phase immobilization of the amplicons. The following reagents were added to a 1.7 ml tube to create a PCR mix. 10 × HIFI buffer 100 μl 10 mM dNTP mix 100 μl 50 mM MgSO4 60 μl 5′-Bio-3HEG-MMP1B 10 μl MMP1A 10 μl HIFI Taq Polymerase 10 μl Mol. Bio. Grade Water 690 μl Twenty microliters of plasmid template DNA was added and the mix was aliquoted by 50 μl into 0.2 ml PCR tubes. The following program was used for thermocycling: incubation at 94° C. for 4 minutes; 39 cycles of incubation at 94° C. for 15 seconds, 58° C. for 30 seconds, 68° C. for 90 seconds, and 68° C. for 120 seconds; hold at 10° C. Amplified DNA for each test fragment was purified using the Qiagen MinElute PCR Clean-Up Kit as per manufacturer's instructions. The purity and yield of each of the test fragments DNA was assessed using the Agilent 2100 Bioanalyzer and DNA 500 reagent kit and chip. Biotinylated PCR products were immobilized onto Sepharose streptavidin beads at 10 million DNA copies/bead. Beads were washed once with 2 M NaCl solution. This was done by adding 100 μl, vortexing briefly to resuspend the beads, centrifuging for 1 minute at maximum speed to pellet the beads, and then removing the supernatant. This was followed by a second wash with 2 M NaCl. The beads were then resuspended in 30 μl of 2 M NaCl. PCR product was added to beads. The mixture was vortexed to resuspend the beads in solution and then placed in a rack, on a titer plate shaker, at speed 7, for 1 hour at room temperature. The non-biotinylated second strand was removed by incubation with the alkaline melt solution (0.1 M NaOH/0.15 M NaCl) for 10 minutes in an overhead rotator at room temperature. This was followed by washing the beads once with 100 μl of melt solution and three times with 100 μl of 1× annealing buffer (50 mM Tris-Acetate, pH 7.5; 5 mM MgCl2). Sequencing primer was annealed to the immobilized single-stranded DNA by centrifugation for one minute at maximum speed. The supernatant was removed and the beads were resuspended in 25 μl of 1× annealing buffer. Next, 5 μl of sequencing primer MMP7A (100 pmol/μl) was added to the bead suspension and the following temperature profile was used to hybridize the sequencing primer: Incubation at 60° C. for 5 minutes; Decrease 0.1° C./second down to 50° C.; Incubation 50° C. for 5 minutes; Decrease 0.1° C./second down to 40° C.; Incubation at 40° C. for 5 minutes; Decrease 0.1° C./second down to 4° C.; and Hold at 4° C. Beads were washed twice with 100 μl of 1× annealing buffer and then resuspended to a final volume of 200 μl with 1× annealing buffer and stored in 10 μl aliquots in labeled tube strips in a 4° C. refrigerator. Step 3: Sequencing Chemistry Sepharose beads with immobilized single stranded DNA templates and annealed sequencing primer were incubated with E. Coli single strand binding protein (Amersham Biosciences) (5 μl of 2.5 μg/μl ssb stock solution per 50,000 beads) and 500 U (10 μl of 50 U/μl) of Bst DNA polymerase (NEB) in 200 μl of Bst polymerase binding solution (25 mM Tricine pH 7.8; 5 mM magnesium acetate; 1 mM DTT; 0.4 mg/ml PVP MW 360,000) for 30 minutes at room temperature on a rotator. After this, the DNA beads were mixed with the SL beads and deposited into the wells of the PicoTiter Plate as follows. Reagents required for a sequencing run on a 454 instrument included 1) substrate wash solution; 2) apyrase containing wash solution; 3) 100 nM inorganic pyrophosphate calibration standard; 4) individual nucleotide triphosphate solutions. All solutions were prepared in the sulfurylase-luciferase assay buffer with enzyme substrates (25 mM Tricine pH 7.8; 5 mM magnesium acetate; 0.4 mg/ml PVP MW 360,000; 0.01% Tween 20; 300 μM D-luciferin; 4 μM APS). The substrate wash solution was identical to the luciferase assay buffer. The apyrase containing wash solution was based on the luciferase assay buffer, except no enzyme substrates (APS and D-luciferin) were added and this wash contained apyrase (Sigma St. Lous, Mo.; Pyrosequencing AB, Pyrosequencing, Inc. Westborough, Mass.) in the final concentration of 8.5 U/l. Sodium pyrophosphate (PPi) standard was prepared by adding sodium pyrophosphate tetrabasic decahydrate (Sigma, St. Louis, Mo.) to the luciferase assay buffer to a final concentration 100 nM. Nucleotide triphosphates (dCTP, dGTP, TTP; minimum diphosphate grade) (Amersham Biosciences AB, Uppsala, Sweden) were diluted to final concentration of 6.5 μM in the luciferase assay buffer. Deoxyadenosine triphosphate analog, 2′-Deoxyadenosine-5′-O-(1-thiotriphosphate), Sp-isomer (Sp-dATP-α-S, Biolog Life Science Institute, Bremen, Germany) was diluted to final concentration of 50 μM in the luciferase assay buffer. Step 4: Cloning His6-BCCP-sulfurylase and His6-BCCP-Luciferase Bacillus stearothermophilus (Bst) ATP sulfurylase (E. C. 2.7.7.4) and firefly (Photinus pyralis) luciferase (E.C. 1.13.12.7) were cloned into Nhe I-BamH I digested pRSET-A vector (Invitrogen). The coding sequence of the BCCP (biotin carboxyl carrier protein) gene (Alix, J. H., DNA 8 (10), 779-789 (1989); Muramatsu, S. and Mizuno, T., Nucleic Acids Res. 17 (10), 3982 (1989), Jackowski, S. and Alix, J. H., J. Bacteriol. 172 (7), 3842-3848 (1990); Li, S. J. and Cronan, J. E. Jr., J. Biol. Chem. 267 (2), 855-863 (1992), Genbank accession number M80458) was used to design PCR primers to amplify the fragment corresponding to amino acids 87-165 of the BCCP protein. The forward primer was 5′-ctagctagcatggaagcgccagcagca-3′; SEQ ID NO:42 and the reverse primer was 5′-ccgggatccctcgatgacgaccagcggc-3′; SEQ ID NO:43. The PCR cocktail was prepared as Mix 1 and Mix 2, 25 μl each. Mix 1 included 75 pmoles of primers, 100 ng of E. coli genomic DNA and 5 μmoles of dNTPs. Mix 2 included 1 unit of Fidelity Expand DNA polymerase (Boehringer Mannheim/Roche Diagnostics Corporation, Indianapolis, Ind., Cat. No. 1 732 641) and 5 μl of 10×Fidelity Expand buffer (Boehringer Mannheim/Roche Diagnostics Corporation, Indianapolis, Ind.). To allow PCR hot-start, Mix 1 and Mix 2 were heated separately for 20 seconds at 96° C. before they were pooled. The pooled reaction was cycled as follows: incubation at 96° C. for 3 min, 10 cycles of incubation at 96° C. for 30 sec, 55° C. for 1 min, and 68° C. for 2 min, then 20 cycles of incubation at 96° C. for 30 s ec, 60° C. for 1 min, and 68° C. for 2 min, followed by a polishing step of incubation at 72° C. for 7 min. After PCR, a single 250 bp fragment was obtained. The BCCP fragment was digested with Nhe I and BamH I and subcloned into Nhe I-BamH I digested pRSET-A. Step 5: Expression of Sulfurylase and Luciferase. The Bst ATP sulfurylase and P. pyralis luciferase open reading frames were amplified by PCR with primers that contain Pst I/Hind III and BamH I/Xho I sites (the first enzyme was at the 5′ end and the second enzyme was at the 3′end), respectively. This produced an N-terminal fusion of 6×His and BCCP domain to ATP sulfurylase and luciferase. The enzymes were expressed in E. coli using biotin-supplemented growth media to allow for in-vivo biotinylation via the BCCP domain. The enzymes were purified to near homogeneity using a combination of IMAC and a size-exclusion column chromatography. Purification was assessed by electrophoresis using the Agilent 2100 Bioanalyzer on Protein 200 Plus chips. Step 6: Solid Phase Immobilization of Luciferase and Sulfurylase The enzymes were immobilized onto Dynal M-280 streptavidin coated magnetic microparticles (Dynal, Oslo, Norway) and Bangs microspheres (300 nm) by incubation of 1:3 mixture of ATP sulfurylase and luciferase, respectively. The binding was performed by mixing 50 μg of ATP sulfurylase and 150 μg of luciferase with 1 mg of Dynal M-280 beads or 0.6 mg of Bangs microspheres in TAGE buffer (25 mM Tris-Acetate pH 7.8, 200 mM ammonium sulfate, 15% v/v glycerol and 30% v/v ethylene glycol). The mixture was incubated for 1 hour at 4° C. on a rotator. After binding, the beads could be stored at −20° C. in the enzyme solution for 3 months. Before use, beads were washed thoroughly in luciferase assay buffer containing 0.1 mg/ml bovine serum albumin (Sigma, St Louis, Mo.). Immobilized enzyme activity was assayed using a luminometer (Turner, Sunnyvale, Calif.). Washed beads were stored on ice until deposition onto a PTP slide. Step 7: PicoTiterPlates™ (PTPs) The PicoTiterPlates™ (25×75×2 mm) were manufactured by anisotropic etching of fiber optic face plates in a manner similar to that described in literature. Plates were etched in three different microwell depths, 26, 50 and 76 mm. Microwell center-to-center pitch was 50 μm, and well diameters ranged between 39 and 44 μm with a calculated well density of 480 wells/mm2. Step 8: PTP Loading Sepharose beads carrying DNA templates and Dynal M-280/Bangs 0.3 μm bead mixture with immobilized sulfurylase and luciferase enzymes were deposited into individual wells of a PicoTiter plate using a centrifugation-based method. The procedure employed an in-house polycarbonate fixture (jig) which included a bottom plate (with slide positioning pegs), an elastomer sealing gasket, and a top plate with two loading ports. The PTP slide was placed onto the bottom plate with the etched side facing up and the top plate with sealing gasket in place was clamped on top of the PTP slide. The whole assembly was tightened with four plastic screws in order to provide a water-tight seal. The sealing gasket was designed to form a mask for bead deposition, resulting in one hexagonal area (14×43 mm) covering roughly 270,000 PTP wells. Beads were deposited in ordered layers. The PTP was removed from incubating in Bead Wash Buffer. Layer 1, a mix of DNA and enzyme beads, was deposited. After centrifuging, Layer 1 supernatant was aspirated off the PTP and Layer 2, Dynal enzyme beads, was deposited. A bead suspension was prepared by mixing 150,000 DNA carrying Sepharose beads in 120 μl of the ssb/Bst pol binding mix (see above) with 270 μl of Dynal-SL and Bangs-SL beads (both at 10 mg/ml) in a total volume of 500 μl of the luciferase assay buffer containing 0.1 mg/ml bovine serum albumin. The bead slurry was vortexed and flowed into the bead deposition jig through pipetting ports. Care was taken to aviod introducing air bubbles. The jig/PTP assembly was centrifuged at 2000 rpm for 8 minutes in a Beckman Allegra 6 centrifuge equipped with a 4-position plate swing-out rotor. After centrifugation, the supernatant was carefully removed from the jig chamber using a pipette. A second layer of only Dynal-SL beads was deposited. This layer included 125 μl of Dynal-SL (at 10 mg/ml) and 375 μl Bead Wash Buffer in a 1.5 ml tube (2.5 mg/ml Dynal beads). The Dynal bead mixture was pipetted into the PTP main active area and centrifuged for 8 minutes at 2000 rpm. Layer 2 mixture was aspirated and the PTP was placed back into Bead Wash Buffer (luciferase assay buffer with 0.1 mg/ml bovine serum albumin and 8.5 U/I apyrase) until ready to load onto the Sequencer. Step 9: Sequencing Instrument The in-house sequencing instrument included three major assemblies: a fluidics subsystem, a PTP cartridge/flow chamber, and an imaging subsystem. The fluidics subsystem included reagent reservoirs, reagents inlet lines, a multi-valve manifold, and a peristaltic pump. It allowed for reagent delivery into the flow chamber, one reagent at a time, at a pre-programmed flow rate and duration. The PTP cartridge/flow chamber was designed in such a way that after attaching a PTP, there would be 300 μm space between the PTP top (etched side) and the chamber ceiling. It included means for temperature control of the reagents and PTP, as well as a light-tight housing. The polished side of a PTP was exposed at the back side of the PTP cartridge and was placed directly in contact with the imaging system. The imaging system comprised a CCD camera with a 1-1 imaging fiber bundle, as well as cryogenic cooling system for the camera, and camera control electronics. The camera used was a Spectral Instruments (Tucson, Ariz.) series 600 camera with a Fairchild Imaging LM485 CCD (16 million pixels, 15 μm pixel size). This was bonded directly to the imaging fiber bundle with 6 μm fiber pitch. The camera was cooled to −70° C. and operated in a frame transfer mode. In this way, the center portion of the CCD was used for imaging while the outer portion of the CCD was used for image storage and read-out. The read-out occurred through 4 ports at each corner of the CCD. The data acquisition rate was set to 1 frame per 30 seconds. The frame-transfer shift time was approximately 0.25 seconds. All camera images were stored in a UTIFF 16 format on a computer hard drive (IBM eServer xSeries 335, IBM, White Plains, N.Y.). Step 10: Sequencing Run Conditions The cyclical delivery of sequencing reagents into the PTP wells and washing of the sequencing reaction byproducts from the wells was achieved by a pre-programmed operation of the fluidics system. The program was written in a form of a Microsoft Excel script, specifying the reagent name (Wash, dATPαS, dCTP, dGTP, dTTP, PPi standard), flow rate and duration of each script step. Flow rate was set at 3 ml/min for all reagents and the linear velocity within the flow chamber was approximately. An initial wash step (5 minutes) was followed by a PPi standard flow (2 min), followed by 21 or 42 cycles of (Wash-C-Wash-A-Wash-G-Wash-T), where each nucleotide flow was 0.5 minute and wash steps were 2 minutes. After all cycles of nucleotide additions and washes, a second PPi standard flow (2 min) was delivered, followed by a final 5 minutes wash step. The total run time was 4 hours. Reagent volumes required to complete this run script were as follows: 300 ml each wash solution, 50 ml of each nucleotide solution, 20 ml of PPi standard solution. During the run, all reagents were kept at room temperature. Because the flow chamber and flow chamber inlet tubing were maintained at 3° C., all reagents entering the flow chamber were at 30° C. REFERENCES Hamilton, S. C., J. W. Farchaus and M. C. Davis. 2001. DNA polymerases as engines for biotechnology. BioTechniques 31:370. QiaQuick Spin Handbook (QIAGEN, 2001): hypertext transfer protocol://world wide web.qiagen.com/literature/handbooks/qqspin/1016893HBQQSpin_PCR_mc_prot.pdf Quick Ligation Kit (NEB): hypertext transfer protocol://world wide web.neb.com/neb/products/mod-enzymes/M2200.html. MinElute kit (QIAGEN): hypertext transfer protocol://world wide web.qiagen.com/literature/handbooks/minelute/1016839_HBMinElute_Prot_Gel.pdf Biomagnetic Techniques in Molecular Biology, Technical Handbook, 3rd edition (Dynal, 1998): hypertext transfer protocol://world wide web.dynal.no/kunder/dynal/DynalPub36.nsf/cb927fbab 127a0ad4125683b004b011c/4908 f5b1 a665858a41256adf05779f2/$FILE/Dynabeads M-280 Streptavidin.pdf Bio Analyzer User Manual (Agilent): hypertext transfer protocol://world wide web.chem.agilent.com/temp/rad31 B29/00033620.pdf BioAnalyzer DNA and RNA LabChip Usage (Agilent): hypertext transfer protocol:H/world wide web.agilent.com/chem/labonachip BioAnalyzer RNA 6000 Ladder (Ambion): hypertext transfer protocol://world wide web.ambion.com/techlib/spec/sp—7152.pdf | <SOH> BACKGROUND OF THE INVENTION <EOH>Development of rapid and sensitive nucleic acid sequencing methods utilizing automated DNA sequencers has revolutionized modern molecular biology. Analysis of entire genomes of plants, fungi, animals, bacteria, and viruses is now possible with a concerted effort by a series of machines and a team of technicians. However, the goal of rapid and automated or semiautomatic sequencing of a genome in a short time has not been possible. There continues to be technical problems for accurate sample preparation, amplification and sequencing. One technical problem which hinders sequence analysis of genomes has been the inability of the investigator to rapidly prepare numerous nucleic acid sample encompassing a complete genome in a short period of time. Another technical problem is the inability to representatively amplified a genome to a level that is compatible with the sensitivity of current sequencing methods. Modern economically feasible sequencing machines, while sensitive, still require in excess of one million copies of a DNA fragment for sequencing. Current methods for providing high copies of DNA sequencing involves variations of cloning or in vitro amplification which cannot amplify the number of individual clones (600,000 or more, and tens of millions for a human genome) necessary for sequencing a whole genome economically. Yet another technical problem in the limitation of current sequencing methods which can perform, at most, one sequencing reaction per hybridization of oligonucleotide primer. The hybridization of sequencing primers is often the rate limiting step constricting the throughput of DNA sequencers. In most cases, Polymerase Chain Reaction (PCR; Saiki, R. K., et al., Science 1985, 230, 1350-1354; Mullis, K., et al., Cold Spring Harb. Symp. Quant. Biol. 1986, 51 Pt 1, 263-273) plays an integral part in obtaining DNA sequence information, amplifying minute amounts of specific DNA to obtain concentrations sufficient for sequencing. Yet, scaling current PCR technology to meet the increasing demands of modern genetics is neither cost effective nor efficient, especially when the requirements for full genome sequencing are considered. Efforts to maximize time and cost efficiencies have typically focused on two areas: decreasing the reaction volume required for amplifications and increasing the number of simultaneous amplifications performed. Miniaturization confers the advantage of lowered sample and reagent utilization, decreased amplification times and increased throughput scalability. While conventional thermocyclers require relatively long cycling times due to thermal mass restrictions (Woolley, A. T., et al., Anal. Chem. 1996, 68, 4081-4086), smaller reaction volumes can be cycled more rapidly. Continuous flow PCR devices have utilized etched microchannels in conjunction with fixed temperature zones to reduce reaction volumes to sub-microliter sample levels (Lagally, E. T., et al., Analytical Chemistry 2001, 73, 565-570; Schneegas, I., et al., Lab on a Chip—The Royal Society of Chemistry 2001, 1, 42-49). Glass microcapillaries, heated by air (Kalinina, O., et al., Nucleic Acids Res. 1997, 25, 1999-2004) or infrared light (Oda, R. P., et al., Anal. Chem. 1998, 70, 4361-4368; Huhmer, A. F. and Landers, J. P., Anal. Chem. 2000, 72, 5507-5512), have also served as efficient vessels for nanoliter scale reactions. Similar reaction volumes have been attained with microfabricated silicon thermocyclers (Burns, M. A., et al., Proc. Natl. Acad. Sci. USA 1996, 93, 5556-5561). In many cases, these miniaturizations have reduced total PCR reaction times to less than 30 minutes for modified electric heating elements (Kopp, M. U., et al., Science 1998, 280, 1046-1048; Chiou, J., Matsudaira, P., Sonin, A. and Ehrlich, D., Anal. Chem. 2001, 73, 2018-2021) and hot air cyclers (Kalinina, O., et al., Nucleic Acids Res. 1997, 25, 1999-2004), and to 240 seconds for some infrared controlled reactions (Giordano, B. C., et al., Anal. Biochem. 2001, 291, 124-132). Certain technologies employ increased throughput and miniaturization simultaneously; as in the 1536-well system design by Sasaki et al. (Sasaki, N., et al., DNA Res. 1997, 4, 387-391), which maintained reaction volumes under 1 μl. As another example, Nagai et al. (Nagai, H., et al., Biosens. Bioelectron. 2001, 16, 1015-1019; Nagai, H., et al., Anal. Chem. 2001, 73, 1043-1047) reported amplification of a single test fragment in ten thousand 86 pl reaction pits etched in a single silicon wafer. Unfortunately, recovery and utilization of the amplicon from these methods have proven problematic, requiring evaporation through selectively permeable membranes. Despite these remarkable improvements in reactions volumes and cycle times, none of the previous strategies have provided the massively parallel amplification required to dramatically increase throughput to levels required for analysis of the entire human genome. DNA sequencers continue to be slower and more expensive than would be desired. In the pure research setting it is perhaps acceptable if a sequencer is slow and expensive. But when it is desired to use DNA sequencers in a clinical diagnostic setting such inefficient sequencing methods are prohibitive even for a well financed institution. The large-scale parallel sequencing of thousands of clonally amplified targets would greatly facilitate large-scale, whole genome library analysis without the time consuming sample preparation process and expensive, error-prone cloning processes. Successful high capacity, solid-phase, clonal DNA amplification can be used for numerous applications. Accordingly, it is clear that there exists a need for preparation of a genome or large template nucleic acids for sequencing, for amplification of the nucleic acid template, and for the sequencing of the amplified template nucleic acids without the constraint of one sequencing reaction per hybridization. Furthermore, there is a need for a system to connect these various technologies into a viable automatic or semiautomatic sequencing machine. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>This invention describes an integrated system, comprising novel methods and novel apparatus for (1) nucleic acid sample preparation, (2) nucleic acid amplification, and (3) DNA sequencing. The invention provides a novel method for preparing a library of multiple DNA sequences, particularly derived from large template DNA or whole (or partial) genome DNA. Sequences of single stranded DNA are prepared from a sample of large template DNA or whole or partial DNA genomes through fragmentation, polishing, adaptor ligation, nick repair, and isolation of single stranded DNA. The method provides for generating a ssDNA library linked to solid supports comprising: (a) generating a library of ssDNA templates; (b) attaching the ssDNA templates to solid supports; and (c) isolating the solid supports on which one ssDNA template is attached. The invention also provides for a method of amplifying each individual member of a DNA library in a single reaction tube, by, e.g., encapsulating a plurality of DNA samples individually in a microcapsule of an emulsion, performing amplification of the plurality of encapsulated nucleic acid samples simultaneously, and releasing said amplified plurality of DNA from the microcapsules for subsequent reactions. In one embodiment, single copies of the nucleic acid template species are hybridized to DNA capture beads, suspended in complete amplification solution and emulsified into microreactors (typically 100 to 200 microns in diameter), after which amplification (e.g., PCR) is used to clonally increase copy number of the initial template species to more than 1,000,000 copies of a single nucleic acid sequence, preferably between 2 and 20 million copies of a single nucleic acid. The amplification reaction, for example, may be performed simultaneously with at least 3,000 microreactors per microliter of reaction mix, and may be performed with over 300,000 microreactors in a single 100 μl volume test tube (e.g., a PCR reaction tube). The present invention also provides for a method of enriching for those beads that contains a successful DNA amplification event (i.e., by removing beads that have no DNA attached thereto). The invention also provides for a method of sequencing a nucleic acid from multiple primers with a single primer hybridization step. Two or more sequencing primers are hybridized to the template DNA to be sequenced. All the sequencing primers are then protected except for one. Sequencing (e.g., pyrophosphate sequencing) is performed again by elongating the unprotected primer. The elongation is either allowed to go to completion (with additional polymerase and dNTPs if necessary) or is terminated (by polymerase and ddNTPs). Chain completion and/or termination reagents are removed. Then one of the protected primers is unprotected and sequencing is performed by elongating the newly unprotected primer. This process is continued until all the sequencing primers are deprotected and sequenced. In a preferred embodiment, two primers (one protected and one unprotected) are used to sequence both ends of a double stranded nucleic acid. The invention also provides an apparatus and methods for sequencing nucleic acids using a pyrophosphate based sequencing approach. The apparatus has a charge coupled device (CCD) camera, microfluidics chamber, sample cartridge holder, pump and flow valves. The apparatus uses chemiluminescence as the detection method, which for pyrophosphate sequencing has an inherently low background. In a preferred embodiment, the sample cartridge for sequencing is termed the ‘PicoTiter plate,’ and is formed from a commercial fiber optics faceplate, acid-etched to yield hundreds of thousands of very small wells, each well volume of 75 pL. The apparatus includes a novel reagent delivery cuvette adapted for use with the arrays described herein, to provide fluid reagents to the picotiter plate, and a reagent delivery means in communication with the reagent delivery cuvette. Photons from each well on the picotiter plate are channeled into specific pixels on the CCD camera to detect sequencing reactions. | 20040128 | 20080129 | 20050616 | 91865.0 | 1 | WOOLWINE, SAMUEL C | METHODS OF AMPLIFYING AND SEQUENCING NUCLEIC ACIDS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,767,794 | ACCEPTED | Wireless communications system including a wireless device locator and related methods | A wireless communications system may include a plurality of wireless communications devices and a wireless device locator. More particularly, the wireless device locator may include at least one antenna and a transceiver connected thereto, and a controller for cooperating with the transceiver for transmitting a plurality of location finding signals to a target wireless communications device from among the plurality thereof. The target device may transmit a respective reply signal for each of the location finding signals. Additionally, the controller may also cooperate with the transceiver for receiving the reply signals, and it may determine a propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor based upon a known device latency of the target device. As such, the controller may estimate a range to the target device based upon a plurality of determined propagation delays. | 1. A wireless communications system comprising: a plurality of wireless communications devices each having a device type associated therewith from among a plurality of different device types, and each device type having a known device latency associated therewith; and a wireless device locator comprising at least one antenna and a transceiver connected thereto, and a controller for cooperating with said transceiver for transmitting a plurality of location finding signals to a target wireless communications device from among said plurality of wireless communications devices; said target wireless communications device transmitting a respective reply signal for each of said location finding signals; said controller of said wireless device locator also for cooperating with said transceiver for receiving the reply signals, determining a propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor based upon the known device latency of said target wireless communications device, and estimating a range to said target wireless communications device based upon a plurality of determined propagation delays. 2. The wireless communications system of claim 1 wherein said controller estimates the range based upon an average of the propagation delays. 3. The wireless communications system of claim 1 wherein each wireless communications device has a unique identifier (UID) associated therewith; wherein said controller inserts the UID for said target wireless communications device in each of the location finding signals; and wherein said target wireless communications device generates respective reply signals based upon the UID in the locations signals. 4. The wireless communications system of claim 3 wherein said target wireless communications device generates unsolicited signals including the UID thereof; wherein said controller cooperates with said transceiver to receive at least one unsolicited signal from said target device; and wherein said controller determines the UID for said target wireless communications device from the at least one unsolicited signal. 5. The wireless communications system of claim 4 wherein said controller determines the device type of said target wireless communications device based upon the UID thereof. 6. The wireless communications system of claim 5 wherein the UIDs comprise media access control (MAC) addresses of respective wireless communications devices, and wherein said controller determines the device type of said target wireless communications device based upon the MAC address thereof. 7. The wireless communications system of claim 1 wherein said at least one antenna comprises a plurality of antennas; and wherein said controller cooperates with said plurality of antennas to determine a bearing to said target wireless communications device based upon at least one of the received reply signals. 8. The wireless communications system of claim 7 wherein the bearing is a three-dimensional bearing. 9. The wireless communications system of claim 1 wherein said at least one antenna comprises at least one directional antenna. 10. The wireless communications system of claim 1 wherein said wireless device locator further comprises a portable housing carrying said at least one antenna, said transceiver, and said controller. 11. The wireless communications system of claim 1 wherein said wireless communications devices comprise wireless local area network (WLAN) devices. 12. The wireless communications system of claim 1 wherein said wireless communications devices comprise mobile ad-hoc network (MANET) devices. 13. The wireless communications system of claim 1 wherein said wireless communications devices comprise cellular communications devices. 14. A wireless communications system comprising: a plurality of wireless local area network (WLAN) devices each having a device type associated therewith from among a plurality of different device types, and each device type having a known device latency associated therewith; and a wireless device locator comprising at least one antenna and a transceiver connected thereto, and a controller for cooperating with said transceiver for transmitting a plurality of location finding signals to a target WLAN device from among said plurality of WLAN devices; said target WLAN device transmitting a respective reply signal for each of said location finding signals; said controller of said wireless device locator also for cooperating with said transceiver for receiving the reply signals, determining a propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor based upon the known device latency of said target WLAN device, and estimating a range to said target WLAN device based upon an average of a plurality of determined propagation delays. 15. The wireless communications system of claim 14 wherein each WLAN device has a unique identifier (UID) associated therewith; wherein said controller inserts the UID for said target WLAN device in each of the location finding signals; and wherein said target WLAN device generates respective reply signals based upon the UID in the locations signals. 16. The wireless communications system of claim 15 wherein said target WLAN device generates unsolicited signals including the UID thereof; wherein said controller cooperates with said transceiver to receive at least one unsolicited signal from said target WLAN device; and wherein said controller determines the UID for said target WLAN device from the at least one unsolicited signal. 17. The wireless communications system of claim 16 wherein said controller determines the device type of said target WLAN device based upon the UID thereof. 18. The wireless communications system of claim 17 wherein the UIDs comprise media access control (MAC) addresses of respective WLAN devices, and wherein said controller determines the device type of said target WLAN device based upon the MAC address thereof. 19. The wireless communications system of claim 14 wherein said at least one antenna comprises a plurality of antennas; and wherein said controller cooperates with said plurality of antennas to determine a bearing to said target WLAN device based upon at least one of the received reply signals. 20. A wireless device locator for locating a target wireless communications device comprising: at least one antenna and a transceiver connected thereto; and a controller for cooperating with said transceiver for transmitting a plurality of location finding signals to the target wireless communications device and receiving a respective reply signal therefrom for each of said location finding signals, determining a propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor based upon a known device latency of the target wireless communications device, and estimating a range to the target wireless communications device based upon a plurality of determined propagation delays. 21. The wireless device locator of claim 20 wherein said controller estimates the range based upon an average of the propagation delays. 22. The wireless device locator of claim 20 wherein the target wireless communications device has a unique identifier (UID) associated therewith; wherein said controller inserts the UID for the target wireless communications device in each of the location finding signals; and wherein the target wireless communications device generates respective reply signals based upon the UID in the locations signals. 23. The wireless device locator of claim 22 wherein the target wireless communications device generates unsolicited signals including the UID thereof; wherein said controller cooperates with said transceiver to receive at least one unsolicited signal from the target device; and wherein said controller determines the UID for the target wireless communications device from the at least one unsolicited signal. 24. The wireless device locator of claim 20 wherein said at least one antenna comprises a plurality of antennas; and wherein said controller cooperates with said plurality of antennas to determine a bearing to the target wireless communications device based upon at least one of the received reply signals. 25. The wireless device locator of claim 20 wherein said at least one antenna comprises at least one directional antenna. 26. The wireless device locator of claim 20 wherein said wireless device locator further comprises a portable housing carrying said at least one antenna, said transceiver, and said controller. 27. The wireless device locator of claim 20 wherein the target wireless communications device comprises a wireless local area network (WLAN) device. 28. The wireless device locator of claim 20 wherein the target wireless communications device comprises a mobile ad-hoc network (MANET) device. 29. The wireless device locator of claim 20 wherein the target wireless communications device comprises a cellular communications device. 30. A method for locating a target wireless communications device from among a plurality of wireless communications devices, each wireless communications device having a device type associated therewith from among a plurality of different device types, and each device type having a known device latency associated therewith, the method comprising: transmitting a plurality of location finding signals to the target wireless communications device, and receiving a respective reply signal for each of the location finding signals therefrom; determining a propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor based upon the known device latency of the target wireless communications device; and estimating a range to the target wireless communications device based upon a plurality of determined propagation delays. 31. The method of claim 30 wherein the controller estimates the range based upon an average of the propagation delays. 32. The method of claim 30 wherein each wireless communications device has a unique identifier (UID) associated therewith; wherein the target wireless communications device generates unsolicited signals including the UID thereof; and further comprising: receiving at least one unsolicited signal from the target device; determining the UID for the target wireless communications device from the at least one unsolicited signal; and inserting the UID in the location finding signals. 33. The method of claim 32 further comprising determining the device type of the target wireless communications device based upon the UID thereof. 34. The method of claim 30 further comprising determining a bearing to the target wireless communications device based upon at least one of the received reply signals. 35. The method of claim 30 wherein the target wireless communications device comprises a wireless local area network (WLAN) device. 36. The method of claim 30 wherein the target wireless communications device comprises a mobile ad-hoc network (MANET) device. 37. The method of claim 30 wherein the target wireless communications device comprises a cellular communications device. | FIELD OF THE INVENTION The present invention relates to the field of wireless communications systems, and, more particularly, to wireless location devices and related methods. BACKGROUND OF THE INVENTION Wireless location techniques are used in numerous applications. Perhaps the most basic of these applications is for locating lost articles. By way of example, published U.S. patent application No. 2003/0034887 to Crabtree et al. discloses a portable article locator system for locating lost articles such as glasses, keys, pets, television remotes, etc. More particularly, a wireless transceiver is attached to a person, animal, or other object. A handheld locator transmits a locator signal to the wireless transceiver which includes a unique address code of the transceiver. If the received code matches that stored by the wireless transceiver, it sends a return signal back to the locator device. The locator device uses the return signal to determine the distance and/or direction to the wireless transceiver from the user's location. The locator device includes an antenna array which includes a plurality of omni-directional antennas. The locator unit determines the bearing to the wireless transceiver by switching between antennas in the antenna array and using Doppler processing to determine a direction of a wireless signal received from the transceiver. The distance to the wireless transmitter is also determined based upon the reception of the wireless signal at each of the antennas of the antenna array. Furthermore, in one embodiment, which is intended to avoid interference between two or more locators in a common area, a plurality of locator signals may be sent from a locator at a standard repetition rate. The locator's receiver then only listens for responses during predetermined windows following each transmission. In contrast, in some applications it is desirable to determine the location of an unknown signal transmitter. U.S. Pat. No. 5,706,010 to Franke discloses such a system in which a transmitter locator receives a signal from the unknown signal transmitter and processes the signal to determine a bearing to the unknown signal transmitter. The transmitter locator then sends an interrogating signal to the unknown signal transmitter. Upon receiving the interrogating signal, the unknown signal transmitter heterodynes the interrogation signal with its own carrier signal to generate an intermodulation return signal. A processor of the transmitter locator measures the round-trip transit time from the transmission of the interrogation signal to the reception of the intermodulation return signal. A range to the unknown signal transmitter is then calculated based upon the round-trip transit time. Still another application in which locating a wireless communications device is often necessary is in cellular telephone networks. That is, it may be necessary to locate particular cellular telephone users for law enforcement or emergency purposes, for example. U.S. Pat. No. 6,292,665 to Hildebrand et al., which is assigned to the present assignee, discloses a method for geolocating a cellular phone initiating a 911 call. A base station transceiver transmits a supervisory audio tone (SAT), which is automatically looped back by the calling cellular phone. Returned SAT signals are correlated with those transmitted to determine the range of the cellular phone. In addition, incoming signals from the cellular phone, such as the returned SAT signals, are received by a phased array antenna and subjected to angle of arrival processing to determine the direction of the cellular phone relative to the base station. The cellular phone is geolocated based upon the angle of arrival and the range information. A correction factor provided by the manufacturer of a given cellular telephone is used to account for the loopback path delay through the phone. One additional area in which wireless device location can be important is in wireless networks, such as wireless local area networks (WLANs) or wide area networks (WANs), for example. A typical prior art approach to locating terminals within a WLAN includes locating a plurality of receivers at fixed locations within a building, for example, and then determining (i.e., triangulating) the position of a terminal based upon a signal received therefrom at each of the receivers. Another prior art approach for wireless terminal location is to use a direction finding (DF) device which includes a directional antenna for receiving signals when pointed in the direction of a transmitting node. An example of a portable DF device for WLANs is the Yellowjacket 802.11a wi-fi analysis system from Berkeley Varitronics. This device uses a passive DF technique, i.e., it does not solicit any signals from a terminal but instead waits for the terminal to transmit signals before it can determine the direction of the transmission. Despite the advantages of such prior art wireless communications device locators, additional wireless location features may be desirable in various applications. SUMMARY OF THE INVENTION In view of the foregoing background, it is therefore an object of the present invention to provide a wireless communications device locator which provides enhanced location features and related methods. This and other objects, features, and advantages in accordance with the present invention are provided by a wireless communications system which may include a plurality of wireless communications devices each having a device type associated therewith from among a plurality of different device types. Further, each device type may have a known device latency associated therewith. The system may also include a wireless device locator. More particularly, the wireless device locator may include at least one antenna and a transceiver connected thereto, and a controller for cooperating with the transceiver for transmitting a plurality of location finding signals to a target wireless communications device from among the plurality of wireless communications devices. The target wireless communications device may transmit a respective reply signal for each of the location finding signals. Additionally, the controller of the wireless device locator may also cooperate with the transceiver for receiving the reply signals, and it may determine a propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor. This may be done based upon the known device latency of the target wireless communications device. As such, the controller may estimate a range to the target wireless communications device based upon a plurality of determined propagation delays. In other words, the wireless device locator advantageously provides active range finding. In other words, the wireless device locator prompts the target wireless communications device to send reply signals using the location finding signals, rather than passively waiting until the target wireless communications device begins transmitting. This allows for quicker and more efficient device location. Furthermore, by estimating the range based upon a plurality of propagation delays, the wireless device locator mitigates the effects of variations in the device latency time. That is, while the target wireless communication device has a known device latency, there will necessarily be some amount of variance from one transmission to the next. Using a plurality of propagation delays associated with different transmissions provides a significantly more accurate approximation of the device latency time and, thus, a more accurate range estimation. By way of example, the controller may estimate the range based upon an average (e.g., mean, median, mode, etc.) of the propagation delays. In addition, each wireless communications device may have a unique identifier (UID) associated therewith, and the controller may insert the UID for the target wireless communications device in each of the location finding signals. Furthermore, the target wireless communications device may generate respective reply signals based upon the UID in the location finding signals. That is, the target wireless communications device will act upon the location finding signals because these signals include its UID, whereas the other wireless communications device will not. The target wireless communications device may generate unsolicited signals including the UID thereof. As such, the controller may cooperate with the transceiver to receive at least one unsolicited signal from the target device, and the controller may also determine the UID for the target device from the at least one unsolicited signal. Thus, if the UID of a target wireless communications device is not already known, the wireless device locator may passively “listen” for unsolicited signals therefrom (i.e., signals that the wireless communications device did not solicit) and determine the UID based thereon. Additionally, the controller may also determine the device type of the target wireless communications device based upon the UID. By way of example, the UIDs may include media access control (MAC) addresses of respective wireless communications devices. Accordingly, the controller may determine the device type of the target wireless communications device based upon the MAC address in some applications. In accordance with another advantageous aspect of the invention, the at least one antenna may be a plurality of antennas, and the controller may cooperate with the plurality of antennas to determine a bearing to the target wireless communications device based upon at least one of the received reply signals. More particularly, the bearing may be a three-dimensional bearing, which may be particularly useful for locating wireless communications devices within a multi-story building, for example. In particular, the antenna(s) may be one or more directional antennas, for example. Further, the wireless device locator may further include a portable housing carrying the at least one antenna, the transceiver, and the controller. The wireless device locator may be used with numerous type of wireless communications device. For example, the wireless communications devices may be wireless local area network (WLAN) devices, mobile ad-hoc network (MANET) devices, and cellular communications devices. A method aspect of the invention is for locating a target wireless communications device from among a plurality of wireless communications devices, such as those discussed briefly above. The method may include transmitting a plurality of location finding signals to the target wireless communications device, and receiving a respective reply signal for each of the location finding signals therefrom. The method may further include determining a propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor based upon the known device latency of the target wireless communications device. As such, a range to the target wireless communications device may be estimated based upon a plurality of determined propagation delays. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is schematic block diagram of a wireless communications system in accordance with the present invention including a wireless local area network (WLAN) and wireless device locator for locating WLAN devices thereof. FIG. 2 is a schematic block diagram generally illustrating the components of the wireless device locator of FIG. 1. FIG. 3 is a graph illustrating the signal propagation delay and device latency components used by the controller of FIG. 2 to estimate range. FIG. 4 is a schematic block diagram illustrating an embodiment of the wireless device locator of FIG. 2 for a WLAN implementation. FIG. 5 is a schematic block diagram illustrating in greater detail an embodiment of the transceiver of the wireless device locator of FIG. 4. FIGS. 6 and 7 are histograms illustrating range estimation test results performed using the wireless device locator of FIG. 4. FIG. 8 is a graph illustrating bearing determination in accordance with the present invention. FIGS. 9 and 10 are schematic block diagrams illustrating alternate embodiments of the wireless communications system of FIG. 1 including a mobile ad-hoc network (MANET) and a cellular network, respectively. FIG. 11 is a flow diagram illustrating a wireless device location method in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime and multiple prime notation are used to indicate similar elements in different embodiments. Referring initially to FIGS. 1 and 2, a wireless communications system 30 illustratively includes a wireless local area network (WLAN) 31 and a wireless location device 32. The WLAN 31 illustratively includes an access point 33 (e.g., a server) and a plurality of WLAN devices or terminals which communicate therewith wirelessly, such as the laptop computers 34, 35, and the desktop computer 36. Various WLAN protocols may be used in accordance with the present invention for such wireless communications (e.g., IEEE 802.11, Bluetooth, etc.), as will be appreciated by those of skill in the art. Moreover, it will also be appreciated that additional access points and/or other numbers of wireless communications devices may be used, even though only a few number thereof are shown for clarity of illustration. Further, numerous other types of WLAN enabled wireless communications devices (e.g., personal data assistants, etc.) may also be used, as will be further appreciated by those skilled in the art. Each wireless communications device 34-36 in the WLAN 31 has a device type associated therewith from among a plurality of different device types. More particularly, the device type may signify the particular manufacturer and/or model of a given WLAN card or chip set used therein. In some embodiments, it may also signify the standard the device complies with (e.g., IEEE 802.11). The device type is important in that different device types will have known device latencies associated therewith. For example, different WLAN cards or chip sets will have a certain latency associated with the time they take to process a received signal and generate an acknowledgement reply thereto. These delay times may be fairly consistent across different models from a same manufacturer, or they may vary significantly. Additionally, WLAN protocols such as IEEE 802.11 have a specified interframe spacing associated therewith, as will be appreciated by those skilled in the art. Thus, in circumstances where the interframe spacing requirements are closely adhered to, the latency of a given WLAN card or chip set will be substantially equal to the interframe spacing. The wireless device locator 32 illustratively includes an antenna 39 and a transceiver 41 connected thereto, as well as a controller 42 connected to the transceiver. These components may conveniently be carried by a portable housing 43 in some embodiments, although they could be implemented in a more stationary embodiment, if desired. In the illustrated example, the antenna 39 is a directional antenna, although omni-directional antennas may also be used, as will be appreciated by those skilled in the art. It will also be appreciated that various antenna/transceiver combinations may be used. As will be discussed further below, more than one antenna may be used in certain embodiments to provide bearing determination capabilities, and separate transceivers may optionally be used for respective antennas, if desired. Operation of the wireless device locator 32 will now be described with reference to FIG. 3. The controller 42 cooperates with the transceiver 41 for transmitting a plurality of location finding signals to a target wireless communications device to be located from among the plurality of wireless communications devices. In the present example, the laptop 34 is the target device. As will be appreciated by those skilled in the art, each WLAN device 34-36 in the network 31 will have a unique identifier (UID) associated therewith which is used in signals transmitted between the respective devices and the access point 33. The UID distinguishes the devices 34-36 from one another so that each device only acts upon or responds to signals intended for it, and so the access point 33 knows which device it is receiving signals from. Depending upon a given implementation, the wireless locator device 32 may or may not know the UID of the target device 34 before hand. For example, in some embodiments the wireless device locator 32 could download the UID from the access point 33 (either wirelessly or over a wired network connection, for example). This may be the case when trying to locate a node in a LAN where the node is already registered with the network. However, if the UID is not known, the wireless device locator 32 may passively listen to the target device 34 for unsolicited signals being transmitted therefrom. This feature may be advantageous for law enforcement applications, or for locating an interfering node that is not registered with a particular network but causes interference therewith, for example. By “unsolicited” signals it is meant that these signals are not solicited by the wireless device locator 32 itself, although such signals may have been solicited from another source (e.g., the access point 33). The controller 42 cooperates with the transceiver 41 to receive one or more of the unsolicited signals, and the controller determines the UID for the target device 34 therefrom. Of course, the method by which the controller 42 determines the UID from the unsolicited signal will depend upon the given implementation, and whether or to what degree such signals are encrypted. Additionally, the controller 42 may also determine the device type of the target wireless communications device 34 based upon the UID thereof. By way of example, the UIDs may include media access control (MAC) addresses of respective wireless communications devices. The MAC addresses may be specific to a particular type of device manufacturer, or indicate a particular operational protocol with which the device is operating, as will be appreciated by those skilled in the art. Accordingly, the controller may determine the device type of the target wireless communications device 34 based upon the MAC address thereof in some applications. As such, to locate the target device 34, the controller inserts the UID therefor in each of the location finding signals. By way of example, the location finding signal may include the UID of the target device 34 in a header packet and a valid but empty data packet. This will force the target device 34 to generate a reply signal acknowledging receipt of the location finding signal (i.e., an ACK signal). Of course, various other location finding signals could be used to cause the target terminal 34 to generate an ACK signal, as will be appreciated by those skilled in the art. The controller 42 cooperates with the transceiver 41 for receiving the reply signals from the target device 34 via the antenna 39. The location finding signals and reply signals may be radio frequency (RF), microwave, optical, or other suitable types of signals, as will be appreciated by those skilled in the art. The controller 42 determines the propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor, and it uses this propagation delay to estimate a range to the target device 34. However, the propagation delay has to first be determined based upon the total round trip time from the sending of the location finding signal to the reception of the respective reply signal. The total round trip time will include several components. Referring more particularly to FIG. 3, the first component is the time associated with transmitting a location finding signal 45, which is illustrated with an arrow. That is, this is the time from the beginning of the location finding signal transmission (time t0) to end thereof (time t1). Two time axes are shown in FIG. 3. The top or upper axis represents events that occur at the target device 34, while the bottom or lower axis represents events that occur at the wireless device locator 32. The second component of the round trip time is the propagation delay or time tPD1 it takes for the location finding signal 45 to travel from the wireless device locator 32 to the target device 34 (i.e., from time t1 to t2). The third component of the round trip time is the device latency tDL of the target device 34 (i.e., form time t2 to t3). This is the time it takes the target device 34 to receive, process, and transmit a reply signal 46 responsive to the location finding signal 45. The final components of the round trip time are propagation delay tPD2 of the reply signal 46 (i.e., from time t3 to t4), and the reception time thereof by the wireless device locator 32 (i.e., from time t4 to t5). The controller 42 will know the times associated with the transmission of the location finding signal 45 (i.e., from time to t0 t1), as well as the time associated with the reception of the reply signal 46 (i.e., from time t4 to t5) for each round trip, since these can be readily measured by the controller. The quantities that the controller 42 will not know are the propagation delays tPD1, tPD2 and the actual device latency tDL. Yet, as noted above, the controller 42 will have access to the known device latency (i.e., a mean latency) for the given device type of the target device 34, which provides a close approximation of the actual device latency tDL. The known device latency could be a measured value based upon collected data, it could be provided by manufacturers, or it could be based upon a value set in a communications standard, as discussed above, for example. As will be appreciated by those skilled in the art, the actual device latency will likely vary somewhat from one transmission to the next for any wireless communications device, potentially by as little as a few nanoseconds to a few microseconds, depending upon device configurations, processing loads, etc. Accordingly, a close approximation of the total propagation delay (i.e., time tPD1+time tPD2) may therefore be obtained by substituting the known device latency for the actual device latency tDL, and subtracting this value from the time between times t1 and t4. Dividing the total propagation delay by two (since both propagation delays may be considered equal or substantially equal for a stationary or relatively slow moving target device 34) and multiplying this by the speed of light gives the estimated distance to the target device 39, based upon the single propagation delay associated with the signal pair 45, 46. Yet, as noted above, device latencies tend to vary from one transmission to the next. Since the location finding signals and reply signals are traveling at the speed of light, such variances can make a significant difference in the estimated distances. More particularly, light travels approximately 1000 ft. in one microsecond. Thus, if the device latency varies by one microsecond from one transmission to the next, the estimated distance to the target device 34 would similarly vary by 1000 ft. or so, which likely will be an unacceptable accuracy for many applications. In accordance with the present invention, the controller 42 advantageously estimates the range to the target device 34 not solely based upon a single measured propagation delay, but rather upon a plurality thereof. More particularly, by estimating the range based upon a plurality of propagation delays, the wireless device locator 32 mitigates the effects of the variations in the actual device latency time. This provides a significantly more accurate approximation of the device latency time and, thus, a more accurate range estimation. By way of example, the controller 42 may estimate the range based upon an average of the propagation delays, though other suitable statistical functions may also be used (e.g., mean, median, mode, etc.). Of course, it should be noted that the average may be taken on the entire round trip delay instead of first subtracting out the known device latency as described above. That is, the same result may be obtained by first taking the average and then subtracting out the known device latency, as will be appreciated by those skilled in the art. An exemplary embodiment of the present invention is now described with reference to FIGS. 4 and 5. The wireless device locator 32′ may use a personal data assistant (PDA) as the controller 42′, although a personal computer (PC) or other suitable computing device may also be used. More particularly, the PDA 42′ illustratively includes a graphical user interface (GUI) 50′, and a received signal strength indication (RSSI) processing module 51′ for cooperating with the transceiver 41′ to perform above-described range estimation processing operations. More particularly, the RSSI module 51′ may be implemented as a software module which is run on the PDA 42′, as will be appreciated by those skilled in the art, and which cooperates with the GUI to provide range estimates to a user. The PDA 50′ also illustratively includes a battery 52′, which may conveniently be used for powering the various transceiver 41′ components, as shown. Of course, it will be appreciated that separate batteries may be used, or one or more components of the wireless device locator 32′ may be powered by an external (e.g., AC) source. The transceiver 41′ operates in accordance with the IEEE 802.11b standard and includes a MAC-less 802.11b radio 58′ and a field-programmable gate array (FPGA) 53′ connected thereto. The FPGA 53′ illustratively includes a packet building module 54′, a radio configuration module 55′, a receiver filtering module 56′, and a simple MAC processing module 57′ for processing the location finding signals and reply signals and communicating with the radio 53′ in accordance with the 802.11b standard, as will be appreciated by those skilled in the art. More specifically, the MAC-less radio 58′ may be a GINA model RF module from GRE America, Inc., and the FPGA 53′ may be a module EPXA10 from Altera Corp. The hardware components of the FPGA 53″ illustratively include an ARM922T processor 60″, block RAM 61″ therefor, a serial/universal serial bus (USB) interface 62″, and a programmable logic section 63″. Additional circuitry including an oscillator 64″, power management circuitry (i.e., regulators, microprocessor supervisor, etc.) 65″, and a programmable read-only memory (PROM)/boot flash memory 66″ are connected thereto as shown, as will be appreciated by those skilled in the art. Referring now to FIGS. 6-7, a test was conducted in accordance with the present invention in which approximately 1500 location finding signals were transmitted to a stationary wireless IEEE 802.11 device. The time it took to receive the reply signal was measured by ticks of an internal clock of the controller 42, where each tick represents 7.567 ns. From FIG. 6 it may be seen that the reply signals from the target device were returned within between about 20,960 and 21,045 clock ticks, where the transmission of the respective location signals each began at 0 clock ticks. Moreover, if this range is divided into equal sections or bins, the frequency (i.e., number) of round trip times that fell within each of the bins is shown in FIG. 7. Plotting various statistical functions of the measured clock tick samples (such as the mean and the mode) versus the known distance to the target device allowed statistical curve-fitting to take place, as shown in FIG. 6. It was determined from the test results that taking the mean of the samples provided the most accurate range estimation. More particularly, the ranges to several 802.11b target devices at varying distances were estimated using this approach, and the worst case error for the estimated range was never more than 20 ft. Preferably, the location finding signals are transmitted over a relatively short interval (a few seconds or less) so that if the target device is moving the accuracy of the results will not be significantly diminished. Of course, various numbers of location finding signals and transmission intervals may be used depending upon the particular implementation, as will be appreciated by those skilled in the art. In accordance with another advantageous aspect of the invention, multiple antennas 39a″, 39b″ (FIG. 5) may be used to provide target bearing in addition to the estimated range. Referring more particularly to FIG. 8, bearing determination in the case where the antennas 39a″, 39b″ are directional antennas will now be described. The antennas 39a″, 39b″ have respective reception patterns 70a, 70b, which may be orthogonal to one another (i.e., the former is directed along the x-axis, while the latter is directed along the y-axis). The target device is at a point P, which is within the reception patterns 70a, 70b. Each of the antenna gain patterns 70a and 70b can be measured and known to the locator, and represented by gain functions G1(θ) and G2(θ) where θ represents the angle of deviation from a particular reference direction. As such, to determine the line of bearing to the target device, the received signal strength is measured from each of the antennas 70a, 70b, respectively. Based upon this information, the controller 42′ may then find the angle θt using the relationship G1(θt)−G2(θt)=P1−P2, where P1 and P2 is the received signal power off antenna 1 and antenna 2, respectively. In other words, the difference in the signal strength received between the two antennas (P1−P2) should equal the difference in the antenna gain of the two antennas at the angle of the line of bearing (G1(θt)−G2(θt)) Thus, the target line of bearing to the target device is at θt. It should be noted that it is possible that more than one angle θ may satisfy the relationship G1(θt)−G2(θt)=P1−P2. These multiple angles represent a line of bearing ambiguity that can easily be resolved by making multiple measurements, as can be appreciated by those skilled in the art. As noted above, more than one transceiver 41′ may be used in certain embodiments, which would allow signal strength measurements to be taken based upon a same reply signal from the target device. However, if only a single transceiver 41′ is used, the controller 42′ may alternate which antenna 70a, 70b is receiving and measure the received signal strength of successive signals, for example. Moreover, the bearing may be determined in three dimensions, if desired, which may be particularly useful for locating wireless communications devices within a multi-story building, for example, as will be appreciated by those skilled in the art. While the present invention has been described above with reference to a WLAN wireless device locator 32′, it will be appreciated by those skilled in the art that it may also be used in other wireless communications systems with other types of wireless communications devices. Referring more particularly to FIG. 9, a mobile ad-hoc network (MANET) system 90 illustratively includes a wireless device locator 92 including an antenna 99, such as those described above, and a MANET 91. More particularly, the MANET includes MANET nodes or devices 93-96, of which the node 94 is the target node in the illustrated example. Here, the wireless device locator 92 performs range and/or bearing estimation in the same manner described above, except that it will operate in accordance with the appropriate MANET protocol used within the system 90, as will be appreciated by those skilled in the art. Another embodiment is illustrated in FIG. 10, in which a wireless device locator 102 having an antenna 109 is used within a cellular communications system 100 for locating cellular devices (e.g., cellular telephones) 104-106 in cellular network 101. The cellular devices 104-106 place and receive calls via a cellar tower 103, as will be appreciated by those skilled in the art. In the illustrated example, the target device is the cell phone 104. Here again, the wireless device locator 102 will communicate using the appropriate operating protocol being used in the cellular network 101 (e.g., code-division multiple access (CDMA), short message service (SMS), etc.), as will be appreciated by those skilled in the art. Turning now additionally to FIG. 11, a method aspect of the invention is for locating a target wireless communications 34 device from among a plurality of wireless communications devices 34-36. Beginning at Block 110, if the UID for the target device 34 is unknown, the controller 42 may determine the UID from unsolicited signals transmitted by the target device, for example, as described above (Block 112). Of course, in some embodiments, the controller 42 may download the signals from a network access point 33, etc., as also described above. Once the UID for the target wireless communication device 34 is known, location finding signals are transmitted to the target wireless communications device, at Block 113, and respective reply signals for each of the location finding signals are received therefrom, at Block 114. If the device type (and, thus, the known device latency) are known, at Block 115, then the propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor is determined based upon the known device latency of the target wireless communications device 34, at Block 116. As such, a range to the target wireless communications device 34 is estimated based upon a plurality of determined propagation delays (Block 117), as previously discussed above, thus concluding the illustrated method (Block 118). Of course, if the device type is unknown, the controller 42 may determine the device type from the reply signal (Block 119), as discussed above, or by other suitable methods which will be appreciated by those skilled in the art. It should be noted that while this step is shown as occurring after the receipt of the reply signals in the illustrated example, the device type determination may be performed prior thereto, such as while determining the UID, for example. Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Wireless location techniques are used in numerous applications. Perhaps the most basic of these applications is for locating lost articles. By way of example, published U.S. patent application No. 2003/0034887 to Crabtree et al. discloses a portable article locator system for locating lost articles such as glasses, keys, pets, television remotes, etc. More particularly, a wireless transceiver is attached to a person, animal, or other object. A handheld locator transmits a locator signal to the wireless transceiver which includes a unique address code of the transceiver. If the received code matches that stored by the wireless transceiver, it sends a return signal back to the locator device. The locator device uses the return signal to determine the distance and/or direction to the wireless transceiver from the user's location. The locator device includes an antenna array which includes a plurality of omni-directional antennas. The locator unit determines the bearing to the wireless transceiver by switching between antennas in the antenna array and using Doppler processing to determine a direction of a wireless signal received from the transceiver. The distance to the wireless transmitter is also determined based upon the reception of the wireless signal at each of the antennas of the antenna array. Furthermore, in one embodiment, which is intended to avoid interference between two or more locators in a common area, a plurality of locator signals may be sent from a locator at a standard repetition rate. The locator's receiver then only listens for responses during predetermined windows following each transmission. In contrast, in some applications it is desirable to determine the location of an unknown signal transmitter. U.S. Pat. No. 5,706,010 to Franke discloses such a system in which a transmitter locator receives a signal from the unknown signal transmitter and processes the signal to determine a bearing to the unknown signal transmitter. The transmitter locator then sends an interrogating signal to the unknown signal transmitter. Upon receiving the interrogating signal, the unknown signal transmitter heterodynes the interrogation signal with its own carrier signal to generate an intermodulation return signal. A processor of the transmitter locator measures the round-trip transit time from the transmission of the interrogation signal to the reception of the intermodulation return signal. A range to the unknown signal transmitter is then calculated based upon the round-trip transit time. Still another application in which locating a wireless communications device is often necessary is in cellular telephone networks. That is, it may be necessary to locate particular cellular telephone users for law enforcement or emergency purposes, for example. U.S. Pat. No. 6,292,665 to Hildebrand et al., which is assigned to the present assignee, discloses a method for geolocating a cellular phone initiating a 911 call. A base station transceiver transmits a supervisory audio tone (SAT), which is automatically looped back by the calling cellular phone. Returned SAT signals are correlated with those transmitted to determine the range of the cellular phone. In addition, incoming signals from the cellular phone, such as the returned SAT signals, are received by a phased array antenna and subjected to angle of arrival processing to determine the direction of the cellular phone relative to the base station. The cellular phone is geolocated based upon the angle of arrival and the range information. A correction factor provided by the manufacturer of a given cellular telephone is used to account for the loopback path delay through the phone. One additional area in which wireless device location can be important is in wireless networks, such as wireless local area networks (WLANs) or wide area networks (WANs), for example. A typical prior art approach to locating terminals within a WLAN includes locating a plurality of receivers at fixed locations within a building, for example, and then determining (i.e., triangulating) the position of a terminal based upon a signal received therefrom at each of the receivers. Another prior art approach for wireless terminal location is to use a direction finding (DF) device which includes a directional antenna for receiving signals when pointed in the direction of a transmitting node. An example of a portable DF device for WLANs is the Yellowjacket 802.11a wi-fi analysis system from Berkeley Varitronics. This device uses a passive DF technique, i.e., it does not solicit any signals from a terminal but instead waits for the terminal to transmit signals before it can determine the direction of the transmission. Despite the advantages of such prior art wireless communications device locators, additional wireless location features may be desirable in various applications. | <SOH> SUMMARY OF THE INVENTION <EOH>In view of the foregoing background, it is therefore an object of the present invention to provide a wireless communications device locator which provides enhanced location features and related methods. This and other objects, features, and advantages in accordance with the present invention are provided by a wireless communications system which may include a plurality of wireless communications devices each having a device type associated therewith from among a plurality of different device types. Further, each device type may have a known device latency associated therewith. The system may also include a wireless device locator. More particularly, the wireless device locator may include at least one antenna and a transceiver connected thereto, and a controller for cooperating with the transceiver for transmitting a plurality of location finding signals to a target wireless communications device from among the plurality of wireless communications devices. The target wireless communications device may transmit a respective reply signal for each of the location finding signals. Additionally, the controller of the wireless device locator may also cooperate with the transceiver for receiving the reply signals, and it may determine a propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor. This may be done based upon the known device latency of the target wireless communications device. As such, the controller may estimate a range to the target wireless communications device based upon a plurality of determined propagation delays. In other words, the wireless device locator advantageously provides active range finding. In other words, the wireless device locator prompts the target wireless communications device to send reply signals using the location finding signals, rather than passively waiting until the target wireless communications device begins transmitting. This allows for quicker and more efficient device location. Furthermore, by estimating the range based upon a plurality of propagation delays, the wireless device locator mitigates the effects of variations in the device latency time. That is, while the target wireless communication device has a known device latency, there will necessarily be some amount of variance from one transmission to the next. Using a plurality of propagation delays associated with different transmissions provides a significantly more accurate approximation of the device latency time and, thus, a more accurate range estimation. By way of example, the controller may estimate the range based upon an average (e.g., mean, median, mode, etc.) of the propagation delays. In addition, each wireless communications device may have a unique identifier (UID) associated therewith, and the controller may insert the UID for the target wireless communications device in each of the location finding signals. Furthermore, the target wireless communications device may generate respective reply signals based upon the UID in the location finding signals. That is, the target wireless communications device will act upon the location finding signals because these signals include its UID, whereas the other wireless communications device will not. The target wireless communications device may generate unsolicited signals including the UID thereof. As such, the controller may cooperate with the transceiver to receive at least one unsolicited signal from the target device, and the controller may also determine the UID for the target device from the at least one unsolicited signal. Thus, if the UID of a target wireless communications device is not already known, the wireless device locator may passively “listen” for unsolicited signals therefrom (i.e., signals that the wireless communications device did not solicit) and determine the UID based thereon. Additionally, the controller may also determine the device type of the target wireless communications device based upon the UID. By way of example, the UIDs may include media access control (MAC) addresses of respective wireless communications devices. Accordingly, the controller may determine the device type of the target wireless communications device based upon the MAC address in some applications. In accordance with another advantageous aspect of the invention, the at least one antenna may be a plurality of antennas, and the controller may cooperate with the plurality of antennas to determine a bearing to the target wireless communications device based upon at least one of the received reply signals. More particularly, the bearing may be a three-dimensional bearing, which may be particularly useful for locating wireless communications devices within a multi-story building, for example. In particular, the antenna(s) may be one or more directional antennas, for example. Further, the wireless device locator may further include a portable housing carrying the at least one antenna, the transceiver, and the controller. The wireless device locator may be used with numerous type of wireless communications device. For example, the wireless communications devices may be wireless local area network (WLAN) devices, mobile ad-hoc network (MANET) devices, and cellular communications devices. A method aspect of the invention is for locating a target wireless communications device from among a plurality of wireless communications devices, such as those discussed briefly above. The method may include transmitting a plurality of location finding signals to the target wireless communications device, and receiving a respective reply signal for each of the location finding signals therefrom. The method may further include determining a propagation delay associated with the transmission of each location finding signal and the respective reply signal therefor based upon the known device latency of the target wireless communications device. As such, a range to the target wireless communications device may be estimated based upon a plurality of determined propagation delays. | 20040129 | 20060919 | 20050804 | 82386.0 | 1 | AFSHAR, KAMRAN | WIRELESS COMMUNICATIONS SYSTEM INCLUDING A WIRELESS DEVICE LOCATOR AND RELATED METHODS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,767,820 | ACCEPTED | LED light module and lighting string | A lighting module with improved reliability including a pair of LEDs connected in parallel and with the same polarity and a method for making the said light module are disclosed. The parallel LEDs with the same polarity will increase the reliability of the light module and make it suitable for use in light strings where a relatively large number of such light modules are connected in series and where the failure of one such light module will cause the failure of the entire light string. A light string made of such light modules and a method for making the light string are also disclosed. | 1. An apparatus, comprising: a light module, comprising: a first light emitting diode (“LED”); and a second LED connected to the first LED in parallel and with the same polarity. 2. An apparatus as claimed in claim 1, wherein at least one of the first LED and the second LED has a maximum total current rating sufficient to carry all current conducted through the light module. 3. An apparatus as claimed in claim 2, wherein the first and second LEDs have dissimilar electrical characteristics, such that the first LED carries all of the current conducted through the light module while the second LED remains unused unless and until the first LED fails open. 4. An apparatus as claimed in claim 2, wherein the first and second LEDs have similar electrical characteristics. 5. An apparatus as claimed in claim 4, wherein the first and second LEDs have substantially the same forward voltage drop over the operating range of the light module. 6. An apparatus as claimed in claim 5, further comprising a heat sink thermally connected to both the first and second LEDs. 7. An apparatus as claimed in claim 2, further comprising a light-diffuser covering the first and second LEDs. 8. An apparatus as claimed in claim 2, wherein the module further comprising: a third LED connected to the first and second LEDs in parallel but with opposite polarity; and a fourth LED connected to the first and second LEDs in parallel but with opposite polarity. 9. An apparatus as claimed in claim 2, further comprising a plurality of additional light modules as claimed in claim 2, connected together in series and connected to the light module in series. 10. An apparatus as claimed in claim 9, wherein the number of light modules that are connected together in series is selected such that the sum of the minimum operating voltage for each of the light modules is less than or equal to the voltage available to supply the apparatus. 11. An apparatus as claimed in claim 10, wherein the minimum operating voltage of a light module is the greater of the minimum operating voltage of the first LED and the minimum, operating voltage of the second LED. 12. An apparatus as claimed in claim 10, wherein the number of light modules that are connected together in series is selected such that the sum of the maximum operating voltage for each of the light modules is greater than or equal to the voltage available to supply the apparatus. 13. An apparatus as claimed in claim 12, wherein the maximum operating voltage of a light module is the lesser of the maximum operating voltage of the first LED and the maximum operating voltage of the second LED. 14. An apparatus as claimed in claim 12, further comprising means for limiting the current flowing through the light module. 15. An apparatus as claimed in claim 14, wherein the means for limiting current comprises a resistor connected in series with the light module. 16. An apparatus, comprising: a light module, comprising: a first polarized photon-emitting semiconductor device (“PPESD”); and a second PPESD connected to the first PPESD in parallel and with the same polarity. 17. An apparatus as claimed in claim 16, wherein at least one of the first PPESD and the second PPESD has a maximum total current rating sufficient to carry all current conducted through the light module. 18. An apparatus as claimed in claim 17, wherein the first and second PPESDs have dissimilar electrical characteristics, such that the first PPESD carries all of the current conducted through the light module while the second PPESD remains unused unless and until the first PPESD fails open. 19. An apparatus as claimed in claim 17, wherein the first and second PPESDs have substantially the same forward voltage drop over the operating range of the light module. 20. A method, comprising connecting a first light emitting diode (“LED”) and a second LED together in parallel and with the same polarity. | BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to light modules assembled from light emitting diodes (“LEDs”) and to light stings assembled by connecting such light modules together. 2. Description of Related Art LEDs are increasingly used as light sources in various applications. Some of the features that make LEDs attractive include: low power consumption, long lifespan, low heat generation, small size and weight, robustness, fast switching time and availability in a variety of colors. In addition, in recent years, the cost of making LEDs has significantly decreased, making their use more economical, even in cost-sensitive applications. One application where LEDs have become particularly popular in recent times has been household and decorative light strings. Such strings are typically formed from between fifty and one hundred LEDs connected together in series. The low power consumption and low heat generation of LEDs make them particularly suitable for such applications, where the cost of power and fire hazard make other types of light such as incandescent lights less attractive. Nevertheless, there are problems with such strings. Despite their robustness, LEDs do sometimes fail. In the event of failure, the whole light string will go dark, which result is both unattractive and challenging to troubleshoot. The user must then locate the one LED out of fifty or one hundred that is faulty. In a competing product, strings of incandescent lamps, a popular solution to this problem has been to connect all of the lamps together in parallel to form a string. When a lamp in such a parallel circuit fails, the rest of the lamps continue to shine and the defective one is easy to identify and replace. However, parallel circuitry has not been embraced with LED strings. In contrast to incandescent bulbs that can be built with a filament resistance suitable for parallel connection to a source of alternating current, LEDs are confined by their semiconductor properties to having a forward voltage drop typically in the neighborhood of 1.1 to 3.0 volts. As a result, unless voltage-reduction circuitry is in a light string, a large number of LEDs must be connected together in series to produce a total voltage drop equal to the voltage at which the alternating current is supplied, being 110 VAC in North America. For this reason, complete series-strings of LEDs are sometimes connected together in parallel, but the LEDs themselves are connected together in series to form the string. Thus, there is redundancy between the strings and a user can quickly tell if a string is not working, but it is still a challenge to find the LED within a string that is responsible for a malfunction. A second reason that parallel circuitry is not seen in LED strings is that there exists a widely held view in the electronic design community that it is bad practice to connect diodes together in parallel with the same polarity. This view is based on the concern that parallel diodes are not well-suited for carrying more current than a single diode can carry on its own, because unless all parallel diodes have identical forward voltage drops, the one with the lowest forward voltage drop will carry the most current, which will cause its temperature to increase, which will cause its forward voltage drop to decrease further, which will cause it to carry even more current until it perhaps fails. If the failing diode fails open, the other parallel diodes will then be forced to carry more current, until they possibly fail one by one. It is important to note nevertheless, that this view seems to have arisen in the context of power circuits that are tasked with delivering high currents through expensive power diodes. In contrast, LEDs typically have significantly less steep current versus voltage curves than other diodes and, consequently, it is less likely that connecting non-identical LEDs in parallel will give rise to significant current differentials and overheating in one of the LEDs. Furthermore, for typical lower current applications in which LEDs are used, LEDS may be cheap enough to significantly over-specify their rated forward current. Accordingly, what is needed is a way to provide redundancy in an LED light string, such that when an LED fails, the rest of the light string will still function and the failed LED may be identified without undue difficulty. SUMMARY OF THE INVENTION The present invention is directed to this need. According to one aspect of the invention, there is provided a method creating illumination that includes connecting a first light emitting diode (“LED”) and a second LED together in parallel and with the same polarity. According to another aspect of the invention, there is provided an apparatus that includes a light module that has a first LED and a second LED connected to the first LED in parallel and with the same polarity. At least one of the first and second LEDs might have a maximum total current rating sufficient to carry all current conducted through the light module. In one configuration, the first and second LEDs have dissimilar electrical characteristics, such that the first LED carries all of the current conducted through the light module while the second LED remains unused unless and until the first LED fails open. In an alternate configuration, the first and second LEDs have similar electrical characteristics, and in particular the first and second LEDs have substantially the same forward voltage drop over the operating range of the light module. To better achieve similar forward voltage drops, the first and second LEDs are thermally connected to a common heat sink. The apparatus might also have a light-diffuser covering the first and second LEDs. The module might also have a third LED connected to the first and second LEDs in parallel but with opposite polarity and a fourth LED connected to the first and second LEDs in parallel but with opposite polarity. The module could also be connected together in series with other similar modules to provide a string of such light modules. The actual number of light modules that are connected together in series would be selected such that the sum of the minimum operating voltage for each of the light modules is less than or equal to the voltage available to supply the apparatus. For example, the minimum operating voltage of a light module might be the greater of the minimum operating voltage of the first LED and the minimum operating voltage of the second LED. Furthermore, the number of light modules that are connected together in series would be selected such that the sum of the maximum operating voltage for each of the light modules is greater than or equal to the voltage available to supply the apparatus. For example, the maximum operating voltage of a light module might be the lesser of the maximum operating voltage of the first LED and the maximum operating voltage of the second LED. The apparatus might also include a way of limiting the current flowing through the light module, for example a resistor connected in series with the light module. According to another aspect of the invention, there is provided an apparatus that includes a light module having a first polarized photon-emitting semiconductor device (“PPESD”) and a second PPESD connected to the first PPESD in parallel and with the same polarity. At least one of the first PPESD and the second PPESD might have a maximum total current rating sufficient to carry all current conducted through the light module. In one configuration, the first and second PPESDs have dissimilar electrical characteristics, such that the first PPESD carries all of the current conducted through the light module while the second PPESD remains unused unless and until the first PPESD fails open. In an alternate configuration, the first and second PPESDs have substantially the same forward voltage drop over the operating range of the light module. Further aspects and advantages of the present invention will become apparent upon considering the following drawings, description, and claims. DESCRIPTION OF THE INVENTION The invention will be more fully illustrated by way of a detailed description of specific exemplary embodiments in conjunction with the accompanying drawing figures, in which like reference numerals designate like parts throughout the various figures. 1. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a light module according to a first embodiment of the invention. FIG. 2 is a schematic diagram of a second light module according to a second embodiment of the invention. FIG. 3 is a schematic diagram of a light string according to a third embodiment of the invention. FIG. 4 is a schematic diagram of a light string according to a fourth embodiment of the invention. FIG. 5 is a schematic diagram of a light string according to a fifth embodiment of the invention. FIG. 6 is a schematic diagram of a light string according to a sixth embodiment of the invention. FIG. 7 is a wiring schematic of a light string according to a seventh embodiment of the invention. FIG. 8 is a pictorial view of the light string illustrated in FIG. 7. 2. DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS FIG. 1 shows a light module according to one embodiment of the present invention, generally illustrated at 25. The light module 25 includes a pair of light emitting diodes (“LEDs”) 22, 23 that are connected together in parallel and with the same polarity. It is desirable that the pair of LEDs 22, 23 each has a maximum reverse voltage greater than the maximum voltage likely to be encountered in use. It is also desirable that the pair of LEDs 22, 23 each has a rated forward current greater than the maximum total current expected to flow through light module 25, so that in other words either of the pair of LEDs 22, 23 is capable of carrying the total current. In general, it is desirable that the pair of LEDs 22, 23 have substantially similar electrical characteristics; however, most particularly, it is desirable that the pair of LEDs 22, 23 each has the same or a substantially similar forward voltage drop over the typical range of operating conditions so as to reduce the likelihood that a significant difference in forward current will develop between the pair of LEDs 22, 23. In this sense, the term substantially similar means that in operation one of the pair of LEDs 22, 23 does not carry all or substantially all of the current flowing through the light module 25. Besides taking care to select LEDs from a common production batch, there are many well-known design and assembly techniques for encouraging components to have similar electrical operating characteristics and it is understood that those would be used in the present case where applicable. For example, where temperature effects might be expected to influence the behavior of the pair of LEDs 22,23, the pair of LEDs 22, 23 could be thermally connected to a common heat sink 48. If one of the pair of LEDs 22, 23 fails open, the other will still function and therefore the light module 25 will still illuminate. The remaining one of the pair of LEDs 23, 22 will carry the full current on its own. Furthermore, so long as it has been over-specified with a suitably high rated forward current it will continue to function properly. This LED-redundancy is inexpensive at these low current levels and because the pair of LEDs 22, 23 are connected in parallel to achieve redundancy rather than higher current carrying capacity, there is good reason for going against the conventional view that diodes should not be connected in parallel with the same polarity. It will be appreciated that, even though it might be desirable for the pair of LEDs 22, 23 to be well-matched such that they both carry a share of the current conducted through the light module 25, this arrangement is not required for the invention to yield benefit. So long as each of the pair of LEDs 22, 23 is over-specified with a high enough rated forward current to carry the full current conducted through the light module 25, then improved redundancy is achieved even if one of the pair of LEDs 22, 23 conducted the full current before it failed open and thereafter the other one of the pair of LEDs 23, 22 conducted the full current. In fact, there may be a benefit to mismatching the pair of LEDs 22, 23, such that the first of the pair of LEDs 22, 23 is held in reserve while the second carries all the current conducted through the light module 25 until it fails open, at which point the fresh first of the pair of LEDs 22, 23 takes over carrying all of the current conducted through the light module 25. Those skilled in the art will appreciate that increased redundancy, and therefore reliability for the light module 25, may be obtained by connecting more than two LEDs in parallel and with the same polarity. FIG. 2 shows a light module according to a second embodiment of the present invention, generally illustrated at 46. The light module 46 includes a first pair of LEDs 42, 43 that are connected in parallel and with the same polarity and a second pair of LEDs 44, 45 that are connected in parallel and with the same polarity, which is opposite to the polarity of the first pair of LEDs 42, 43. Unlike the first embodiment light module 25, which is configured to provide illumination only when a source of electromotive force is applied to forward bias the pair of LEDs 22, 23, the second embodiment light module 46 is configured to provide illumination both when a source of electromotive force is applied to forward bias the first pair of LEDs 42, 43 and when a source of oppositely polarized electromotive force is applied to forward bias the second pair of LEDs 44, 45. Thus, when connected to a source of alternating current, the first embodiment light module 25 is configured to provide illumination during approximately half of the cycle of the source current whereas the second embodiment light module 46 is configured to provide illumination during substantially the full cycle of the source current, thus providing a brighter appearance. In addition to illumination during substantially the full cycle of the source current, which will result in the light module 46 appearing brighter, light module 46 has further the advantage of generating less electromagnetic interference. Because the current flowing through light module 46 is substantially a full sinusoid, it will contain lower levels of higher order harmonics, which can cause coupled wires to act as an antenna propagating electromagnetic waves with frequencies corresponding to these higher harmonics. It is further desirable that the first embodiment light module 25 and the second embodiment light module 46 each also includes a light-diffuser 27 covering its respective LEDs 22, 23, 42, 43, 44, 45. Each respective light-diffuser 27, 47 is configured to diffuse the light emitted by the respective LEDs 22, 23, 42, 43, 44, 45 such that an observer of the respective light module 25, 46 will be unable to readily distinguish which of the LEDs is the source of the light from the light module 25, 46 or in what relative proportions. FIG. 3 shows a light string according to a third embodiment of the invention, generally illustrated at 108. The light string 108 includes a block 120 of light modules 25 connected in series, all with the same polarity. The light string 108 may include more than one block 120 of light modules 25, as is the case with this third embodiment, which includes a second parallel block 120′ of light modules 25. If an LED, for example one of the pair of LEDs 22, 23 in a particular light module 25, fails open, then the remaining one of the pair of LEDs 23, 22 will carry all of the current flowing through that light module 25, and therefore that light module 25 as a whole will continue to provide light and conduct current and therefore the whole block 120 will continue to provide light and conduct current. FIG. 4 shows a light string according to a fourth embodiment of the invention, generally illustrated at 200. The light string 200 includes a block 220 of light modules 46 connected in series. The light string 200 may be more than one block 220 of light modules 46, as is the case with this fourth embodiment, which includes a second parallel block 220′ of light modules 46. The light string 108, 200 may be configured to connect directly to a source of household alternating current (“AC”). In this configuration, the number of light modules 25, 46 in each block 120, 220 must be selected such that the sum of the minimum operating voltage for each of the light modules 25, 46 is less than or equal to the voltage of the available supply and that the sum of the maximum operating voltage for each of the light modules 25, 46 is greater than or equal to the voltage of the available supply. The minimum and maximum operating voltages of the light modules 25, 46 is essentially the minimum and maximum operating voltages of the respective pairs of LEDs 22, 23, 42, 43, 44, 45. For example, assume that all the light modules 25, 46 in the block 120, 220 are identical and that all the pairs of LEDs 22, 23, 42, 43, 44, 45, have a forward AC voltage operating range of 1.5 VAC to 2.5 VAC and a corresponding current range of 10 mA to 50 mA. If the AC supply voltage is 110 VAC, then with 50 light modules 25, 46 in the block 120,220 the voltage drop across each light module 25, 46 will be approximately 2.2 VAC, which is well within the operating range of each light module 25, 46 and the respective pairs of LEDs 22, 23, 42, 43, 44, 45. FIG. 5 shows a light string according to a fifth embodiment of the invention, generally illustrated at 408. The light string 408 includes at least one block 420 of light modules 25 connected in series. The light string 408 further includes a resistor 54 connected in series with the block 420. The value of resistor 54 may be selected to provide current-limiting in the event of a short circuit in block 420 and to produce during regular operation of the block 420 a voltage drop sufficient to replace one or more light modules 25 if less modules are desired in block 420 than would be required as discussed above with respect to the third and fourth embodiment blocks 120, 200. Those skilled in the art will appreciate that, besides a resistor, other means may be used to limit the current in block 420 or produce a voltage drop equivalent to one or more light modules 25 in series. FIG. 6 shows a light string according to a sixth embodiment of the invention, generally illustrated at 508. The light string 508 includes at least one block 520 of light modules 25 connected in series. The light string 508 further includes a full-wave rectifier 64 coupled to the block 520. This embodiment of the light string 508 is configured to provide current to each light module 25 over the entire AC cycle, such that each light module 25 will appear brighter and steadier. While not shown in FIG. 6, those skilled in the art will appreciate that means for smoothing the ripple in the output of the rectifier 64 may also be coupled to rectifier 64. For example, an inductor may be placed in series between the rectifier 64 and the light modules 25 in the block 520, or a capacitor may be placed in series with the rectifier 64 and in parallel with light modules 25 to smooth the ripple. FIGS. 7 and 8 show a light string according to a seventh embodiment of the invention, generally illustrated at 608. The seventh embodiment light string 608 is similar to the third embodiment light string 108, except that it includes only a single block 620 of light modules 25 connected in series. The light string 608 further includes a plug 71 attached in series to one end of the light string 608, adapted to connect the light string 608 to a source of AC. The light string 608 also includes a receptacle 76 attached in series to the other end of light string 608, adapted for connecting the light string 608 to another appliance (not shown) that requires AC, for example another light string 608. The plug 71 and receptacle 76 are connected together in parallel to the light string 608, so that an open circuit in the light string 608 will not interrupt the AC being provided to the other appliance (not shown). While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims. It will be understood by those skilled in the art that various changes, modifications and substitutions can be made to the foregoing embodiments without departing from the principle and scope of the invention expressed in the claims made herein. For example, although the invention has been discussed in terms of light emitting diodes, those skilled in the art may recognize that similar benefits could be achieved by substituting other similar polarized photon-emitting semiconductor devices, such as light emitting transistors. While the invention has been described as having particular application for decorative lighting, and in particular Christmas lighting, those skilled in the art will recognize it has wider application, for example in optical communications. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates to light modules assembled from light emitting diodes (“LEDs”) and to light stings assembled by connecting such light modules together. 2. Description of Related Art LEDs are increasingly used as light sources in various applications. Some of the features that make LEDs attractive include: low power consumption, long lifespan, low heat generation, small size and weight, robustness, fast switching time and availability in a variety of colors. In addition, in recent years, the cost of making LEDs has significantly decreased, making their use more economical, even in cost-sensitive applications. One application where LEDs have become particularly popular in recent times has been household and decorative light strings. Such strings are typically formed from between fifty and one hundred LEDs connected together in series. The low power consumption and low heat generation of LEDs make them particularly suitable for such applications, where the cost of power and fire hazard make other types of light such as incandescent lights less attractive. Nevertheless, there are problems with such strings. Despite their robustness, LEDs do sometimes fail. In the event of failure, the whole light string will go dark, which result is both unattractive and challenging to troubleshoot. The user must then locate the one LED out of fifty or one hundred that is faulty. In a competing product, strings of incandescent lamps, a popular solution to this problem has been to connect all of the lamps together in parallel to form a string. When a lamp in such a parallel circuit fails, the rest of the lamps continue to shine and the defective one is easy to identify and replace. However, parallel circuitry has not been embraced with LED strings. In contrast to incandescent bulbs that can be built with a filament resistance suitable for parallel connection to a source of alternating current, LEDs are confined by their semiconductor properties to having a forward voltage drop typically in the neighborhood of 1.1 to 3.0 volts. As a result, unless voltage-reduction circuitry is in a light string, a large number of LEDs must be connected together in series to produce a total voltage drop equal to the voltage at which the alternating current is supplied, being 110 V AC in North America. For this reason, complete series-strings of LEDs are sometimes connected together in parallel, but the LEDs themselves are connected together in series to form the string. Thus, there is redundancy between the strings and a user can quickly tell if a string is not working, but it is still a challenge to find the LED within a string that is responsible for a malfunction. A second reason that parallel circuitry is not seen in LED strings is that there exists a widely held view in the electronic design community that it is bad practice to connect diodes together in parallel with the same polarity. This view is based on the concern that parallel diodes are not well-suited for carrying more current than a single diode can carry on its own, because unless all parallel diodes have identical forward voltage drops, the one with the lowest forward voltage drop will carry the most current, which will cause its temperature to increase, which will cause its forward voltage drop to decrease further, which will cause it to carry even more current until it perhaps fails. If the failing diode fails open, the other parallel diodes will then be forced to carry more current, until they possibly fail one by one. It is important to note nevertheless, that this view seems to have arisen in the context of power circuits that are tasked with delivering high currents through expensive power diodes. In contrast, LEDs typically have significantly less steep current versus voltage curves than other diodes and, consequently, it is less likely that connecting non-identical LEDs in parallel will give rise to significant current differentials and overheating in one of the LEDs. Furthermore, for typical lower current applications in which LEDs are used, LEDS may be cheap enough to significantly over-specify their rated forward current. Accordingly, what is needed is a way to provide redundancy in an LED light string, such that when an LED fails, the rest of the light string will still function and the failed LED may be identified without undue difficulty. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is directed to this need. According to one aspect of the invention, there is provided a method creating illumination that includes connecting a first light emitting diode (“LED”) and a second LED together in parallel and with the same polarity. According to another aspect of the invention, there is provided an apparatus that includes a light module that has a first LED and a second LED connected to the first LED in parallel and with the same polarity. At least one of the first and second LEDs might have a maximum total current rating sufficient to carry all current conducted through the light module. In one configuration, the first and second LEDs have dissimilar electrical characteristics, such that the first LED carries all of the current conducted through the light module while the second LED remains unused unless and until the first LED fails open. In an alternate configuration, the first and second LEDs have similar electrical characteristics, and in particular the first and second LEDs have substantially the same forward voltage drop over the operating range of the light module. To better achieve similar forward voltage drops, the first and second LEDs are thermally connected to a common heat sink. The apparatus might also have a light-diffuser covering the first and second LEDs. The module might also have a third LED connected to the first and second LEDs in parallel but with opposite polarity and a fourth LED connected to the first and second LEDs in parallel but with opposite polarity. The module could also be connected together in series with other similar modules to provide a string of such light modules. The actual number of light modules that are connected together in series would be selected such that the sum of the minimum operating voltage for each of the light modules is less than or equal to the voltage available to supply the apparatus. For example, the minimum operating voltage of a light module might be the greater of the minimum operating voltage of the first LED and the minimum operating voltage of the second LED. Furthermore, the number of light modules that are connected together in series would be selected such that the sum of the maximum operating voltage for each of the light modules is greater than or equal to the voltage available to supply the apparatus. For example, the maximum operating voltage of a light module might be the lesser of the maximum operating voltage of the first LED and the maximum operating voltage of the second LED. The apparatus might also include a way of limiting the current flowing through the light module, for example a resistor connected in series with the light module. According to another aspect of the invention, there is provided an apparatus that includes a light module having a first polarized photon-emitting semiconductor device (“PPESD”) and a second PPESD connected to the first PPESD in parallel and with the same polarity. At least one of the first PPESD and the second PPESD might have a maximum total current rating sufficient to carry all current conducted through the light module. In one configuration, the first and second PPESDs have dissimilar electrical characteristics, such that the first PPESD carries all of the current conducted through the light module while the second PPESD remains unused unless and until the first PPESD fails open. In an alternate configuration, the first and second PPESDs have substantially the same forward voltage drop over the operating range of the light module. Further aspects and advantages of the present invention will become apparent upon considering the following drawings, description, and claims. | 20040130 | 20060516 | 20050804 | 80246.0 | 1 | VO, TUYET THI | LED LIGHT MODULE AND SERIES CONNECTED LIGHT MODULES | SMALL | 0 | ACCEPTED | 2,004 |
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10,767,922 | ACCEPTED | Selection of neurostimulator parameter configurations using neural network | In general, the invention is directed to a technique for selection of parameter configurations for a neurostimulator using neural networks. The technique may be employed by a programming device to allow a clinician to select parameter configurations, and then program an implantable neurostimulator to deliver therapy using the selected parameter configurations. The parameter configurations may include one or more of a variety of parameters, such as electrode configurations defining electrode combinations and polarities for an electrode set implanted in a patient. The electrode set may be carried by one or more implanted leads that are electrically coupled to the neurostimulator. In operation, the programming device executes a parameter configuration search algorithm to guide the clinician in the selection of parameter configurations. The search algorithm relies on a neural network that identifies potential optimum parameter configurations. | 1. A method comprising: selecting a first parameter configuration for a neurostimulator; receiving an indication of observed efficacy of the first parameter configuration; and selecting a second parameter configuration for the neurostimulator from a set of additional parameter configurations identified by a neural network. 2. The method of claim 1, wherein the parameter configurations include electrode configurations, each of the electrode configurations defining a combination of two or more electrodes for delivery of neurostimulation energy. 3. The method of claim 2, wherein each of the electrode configurations defines polarities for electrodes in the combination. 4. The method of claim 2, wherein the electrodes are carried by two or more implanted leads. 5. The method of claim 2, wherein the electrodes are associated with different target regions within a body of a patient. 6. The method of claim 5, wherein the implanted leads are implanted proximate a portion of a spine of a patient. 7. The method of claim 2, further comprising updating the neural network based on the observed efficacy. 8. The method of claim 7, wherein updating the neural network includes modifying interconnection weights among nodes in the neural network. 9. The method of claim 8, wherein the nodes include input nodes identifying possible combinations of two or more electrodes, output nodes identifying suggested combinations of two or more electrodes, and hidden nodes interconnecting the input nodes and the output nodes with respective interconnection weights. 10. The method of claim 9, further comprising iteratively selecting additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the neural network structure. 11. The method of claim 10, further comprising terminating the iterative selection of the additional electrode configurations when one or more termination criteria are satisfied. 12. The method of claim 11, wherein the termination criteria include selection of one of the electrode configurations with an observed efficacy that satisfies a threshold efficacy. 13. The method of claim 2, further comprising: iteratively selecting additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the neural network structure; terminating the iterative selection of the additional electrode configurations at a final electrode configuration when one or more termination criteria are satisfied; and programming the neurostimulator to employ the final electrode configuration in delivery of neurostimulation therapy. 14. The method of claim 13, wherein the neurostimulator is a spinal cord stimulator, and the final electrode configuration includes electrodes deployed on one more implanted spinal leads. 15. The method of claim 14, wherein the final electrode configuration defines a combination of two electrodes from a set of at least eight electrodes. 16. The method of claim 1, wherein selecting the first and second parameter configurations includes suggesting the first and second parameter configurations to a clinician. 17. The method of claim 1, wherein receiving an indication relating to observed efficacy includes receiving user input indicating observed efficacy. 18. A computer-readable medium comprising instructions to cause a processor to: selecting a first parameter configuration for a neurostimulator; receive an indication relating to observed efficacy of the first parameter configuration; and selecting a second parameter configuration for the neurostimulator from a set of additional parameter configurations identified by a neural network. 19. The computer-readable medium of claim 18, wherein the parameter configurations include electrode configurations, each of the electrode configurations defining a combination of two or more electrodes for delivery of neurostimulation energy. 20. The computer-readable medium of claim 19, wherein each of the electrode configurations defines polarities for electrodes in the combination. 21. The computer-readable medium of claim 19, wherein the electrodes are carried by two or more implanted leads. 22. The computer-readable medium of claim 19, wherein the electrodes are associated with different target regions within a body of a patient. 23. The computer-readable medium of claim 22, wherein the implanted leads are implanted proximate a portion of a spine of a patient. 24. The computer-readable medium of claim 19, further comprising instructions to cause the processor to update the neural network based on the observed efficacy. 25. The computer-readable medium of claim 24, wherein the instructions to cause the processor to update the neural network include instructions to cause the processor to modify interconnection weights among nodes in the neural network. 26. The computer-readable medium of claim 25, wherein the nodes include input nodes identifying possible combinations of two or more electrodes, output nodes identifying suggested combinations of two or more electrodes, and hidden nodes interconnecting the input nodes and the output nodes with respective interconnection weights. 27. The computer-readable medium of claim 26, further comprising instructions to cause the processor to iteratively select additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the neural network structure. 28. The computer-readable medium of claim 27, further comprising instructions to cause the processor to terminate the iterative selection of the additional electrode configurations when one or more termination criteria are satisfied. 29. The computer-readable medium of claim 28, wherein the termination criteria include selection of one of the electrode configurations with an observed efficacy that satisfies a threshold efficacy. 30. The computer-readable medium of claim 19, further comprising instructions to cause the processor to: iteratively select additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the neural network structure; terminate the iterative selection of the additional electrode configurations at a final electrode configuration when one or more termination criteria are satisfied; and program the neurostimulator to employ the final electrode configuration in delivery of neurostimulation therapy. 31. The computer-readable medium of claim 30, wherein the neurostimulator is a spinal cord stimulator, and the final electrode configuration includes electrodes deployed on one more implanted spinal leads. 32. The computer-readable medium of claim 31, wherein the final electrode configuration defines a combination of two electrodes from a set of at least eight electrodes. 33. The computer-readable medium of claim 18, further comprising instructions to cause the processor to select the first and second parameter configurations includes suggesting the first and second parameter configurations to a clinician. 34. The computer-readable medium of claim 18, wherein the indication relating to observed efficacy includes user input relating to observed efficacy. 35. A device comprising a processor programmed to: select a first parameter configuration for a neurostimulator; receive an indication of observed efficacy of the first parameter configuration; and select a second parameter configuration for the neurostimulator from a set of additional parameter configurations identified by a neural network. 36. The device of claim 35, wherein the parameter configurations include electrode configurations, each of the electrode configurations defining a combination of two or more electrodes for delivery of neurostimulation energy. 37. The device of claim 36, wherein each of the electrode configurations defines polarities for electrodes in the combination. 38. The device of claim 36, wherein the electrodes are carried by two or more implanted leads. 39. The device of claim 36, wherein the electrodes are associated with different target regions within a body of a patient. 40. The device of claim 39, wherein the implanted leads are implanted proximate a portion of a spine of a patient. 41. The device of claim 36, wherein the processor updates the neural network based on the observed efficacy. 42. The device of claim 41, wherein the processor updates interconnection weights among nodes in the neural network. 43. The device of claim 42, wherein the nodes include input nodes identifying possible combinations of two or more electrodes, output nodes identifying suggested combinations of two or more electrodes, and hidden nodes interconnecting the input nodes and the output nodes with respective interconnection weights. 44. The device of claim 43, wherein the processor iteratively selects additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the neural network structure. 45. The device of claim 44, wherein the processor terminates the iterative selection of the additional electrode configurations when one or more termination criteria are satisfied. 46. The device of claim 45, wherein the termination criteria include selection of one of the electrode configurations with an observed efficacy that satisfies a threshold efficacy. 47. The device of claim 36, wherein the processor: iteratively selects additional electrode configurations for the neurostimulator based on observed efficacy of preceding electrode configurations and the neural network structure; terminates the iterative selection of the additional electrode configurations at a final electrode configuration when one or more termination criteria are satisfied; and programs the neurostimulator to employ the final electrode configuration in delivery of neurostimulation therapy. 48. The device of claim 47, wherein the neurostimulator is a spinal cord stimulator, and the final electrode configuration includes electrodes deployed on one more implanted spinal leads. 49. The device of claim 48, wherein the final electrode configuration defines a combination of two electrodes from a set of at least eight electrodes. 50. The device of claim 35, wherein the processor selects the first and second parameter configurations by suggesting the first and second parameter configurations to a clinician. 51. The device of claim 35, wherein the indication relating to observed efficacy includes user input relating to observed efficacy. | This application claims the benefit of U.S. provisional application Ser. No. 60/503,206, filed Sep. 15, 2003, the entire content of which is incorporated herein by reference. TECHNICAL FIELD The invention relates to neurostimulation therapy and, more particularly, to techniques for selection of parameter configurations for an implantable neurostimulator. BACKGROUND Implantable medical devices are used to deliver neurostimulation therapy to patients to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson's disease, epilepsy, incontinence, sexual dysfunction, or gastroparesis. The implantable medical device delivers neurostimulation therapy via one or more leads that include electrodes located proximate to the spinal cord, pelvic nerves, sacrum, or stomach, or within the brain of a patient. In general, the implantable medical device delivers neurostimulation therapy in the form of electrical pulses. A clinician selects values for a number of programmable parameters in order to define a parameter configuration for the neurostimulation therapy to be delivered to a patient. For example, the clinician may select an amplitude, which may be a current or voltage amplitude, and pulse width for a stimulation waveform to be delivered to the patient, as well as a rate at which the pulses are to be delivered to the patient, and duration for which the stimulation energy is delivered. In addition, the clinician also selects particular electrodes within an electrode set to be used to deliver the pulses, and the polarities of the selected electrodes. The electrode combination and polarities may be referred to as an electrode configuration. Hence, a parameter configuration may involve a variety of parameters including electrode configuration, amplitude, pulse width, pulse rate, and duration. The process of selecting parameter configurations can be time consuming, and may require a great deal of trial and error before an optimum electrode configuration is discovered. The optimum parameter configuration may be better than other configurations in balancing clinical results and side effects experienced by the patient. This balance represents overall efficacy of a parameter configuration. The process for selecting parameter configurations can be difficult due to the combinatorial possibilities of parameters, the complexity of the underlying biophysics, and subjective and possibly inconsistent feedback from the patient concerning observed efficacy for a given parameter configuration. SUMMARY In general, the invention is directed to a technique for selection of parameter configurations for a neurostimulator using neural networks. The technique may be employed by a programming device to allow a clinician to select parameter configurations, and then program an implantable neurostimulator to deliver therapy using the selected parameter configurations. A parameter configuration may define one or more parameters for delivery of neurostimulation, such as electrode configuration, amplitude, pulse width, pulse rate, or duration. For example, the parameter configurations may define electrode configurations that specify electrode combinations and polarities for an electrode set implanted in a patient. The electrode set may be carried by one or more implanted leads that are electrically coupled to the neurostimulator. In some embodiments, the parameter configurations may further define one or more parameters such as amplitudes, pulse widths, pulse rates, and durations of stimulation energy delivered by electrodes in the electrode configuration. In operation, the programming device executes a parameter configuration search algorithm to guide the clinician in the selection of parameter configurations. The search algorithm relies on a neural network that identifies potential optimum parameter configurations, such as electrode configurations within an electrode set. The neural network is trained to classify optimum parameter configurations based on observed example configurations within a programming session. The neural network structure can be trained from a set of existing parameter configuration data, and then learn in the course of evaluating new parameter configurations. In particular, the neural network may be updated based on new observations obtained for parameter configurations during the search. With the aid of the neural network, a programming device provides a clinician with suggestions of which configurations are most likely to be efficacious given observations already obtained during the selection process. In general, efficacy refers to the balance between therapeutic benefit and undesirable side effects. As examples, efficacy can be observed by verbal feedback from the patient concerning therapeutic benefit and side effects, marking of a pain/parasthesia map, objective measurement using pain rating scales, quantification of side effects, a combination of the forgoing, or other observation techniques. In one embodiment, the invention provides a method comprising selecting a first parameter configuration for a neurostimulator, observing efficacy of the first parameter configuration, and selecting a second parameter configuration for the neurostimulator from a set of additional parameter configurations identified by a neural network. In another embodiment, the invention provides a computer-readable medium comprising instructions to cause a processor to select a first parameter configuration for a neurostimulator, observe efficacy of the first parameter configuration, and select a second parameter configuration for the neurostimulator from a set of additional parameter configurations identified by a neural network. In a further embodiment, the invention provides a device comprising a processor programmed to select a first parameter configuration for a neurostimulator, observe efficacy of the first parameter configuration, and select a second parameter configuration for the neurostimulator from a set of additional parameter configurations identified by a neural network. The invention may provide a number of advantages. For example, the invention may allow a clinician to more quickly identify desirable parameter configurations such as electrode combinations, reducing the overall amount of time the clinician spends programming neurostimulation therapy for a patient. In contrast to random or idiosyncratic search techniques, a technique based on neural networks is capable of learning from the evaluation of earlier parameter configurations, and developing a network structure that is more likely to lead to an optimum configuration. In general, the invention can reduce the length of a programming session for the clinician and the patient, and support selection of optimum electrode configurations to achieve overall efficacy. In addition, with the invention, it may be possible to identify optimal or near optimal parameter configurations that otherwise might not be identified by the clinician. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram illustrating a system for programming and delivering neurostimulation therapy. FIG. 2 is a diagram illustrating an example electrode set implanted proximate to the spine of a patient. FIG. 3 is a block diagram illustrating a programming device used to identify desirable parameter configurations for neurostimulation therapy programs. FIG. 4 is a diagram illustrating the structure of a neural network configured to identify optimal parameter configurations. FIG. 5 is a flow diagram illustrating a search algorithm that is executable by a programmer to select parameter configurations using a neural network. DETAILED DESCRIPTION FIG. 1 is a diagram illustrating an example system 10 for programming neurostimulation therapy for and delivering neurostimulation therapy to a patient 12. System 10 includes an implantable medical device (IMD) 14 that delivers neurostimulation therapy to patient 12. IMD 14 may be an implantable pulse generator, and may deliver neurostimulation therapy to patient 12 in the form of electrical pulses. System 10 makes use of neural network structures for selection of parameter configurations. IMD 14 delivers neurostimulation therapy to patient 12 via leads 16A and 16B (collectively “leads 16”). Leads 16 may, as shown in FIG. 1, be implanted proximate to the spinal cord 18 of patient 12, and IMD 14 may deliver spinal cord stimulation (SCS) therapy to patient 12 in order to, for example, reduce pain experienced by patient 12. However, the invention is not limited to the configuration of leads 16 shown in FIG. 1 or the delivery of SCS therapy. For example, one or more leads 16 may extend from IMD 14 to the brain (not shown) of patient 12, and IMD 14 may deliver deep brain stimulation (DBS) therapy to patient 12 to, for example, treat tremor or epilepsy. As further examples, one or more leads 16 may be implanted proximate to the pelvic nerves (not shown), sacrum (not shown) or stomach (not shown), and IMD 14 may deliver neurostimulation therapy to treat incontinence, sexual dysfunction, or gastroparesis. IMD 14 delivers neurostimulation therapy to patient 12 according to one or more neurostimulation therapy programs. A neurostimulation therapy program may include values for a number of parameters, and the parameter values define a parameter configuration for delivery of the neurostimulation therapy according to that program. In embodiments where IMD 14 delivers neurostimulation therapy in the form of electrical pulses, the parameters may include pulse voltage or current amplitudes, pulse widths, pulse rates, durations and the like. Further, each of leads 16 includes electrodes (not shown in FIG. 1), and the parameters for a program may include information identifying which electrodes have been selected for delivery of pulses according to the program, and the polarities of the selected electrodes. Hence, a parameter configuration may involve one or more of a variety of parameters including electrode configuration, amplitude, pulse width, pulse rate, and duration. Although the invention may be applicable to neurostimulation parameter configuration in general, including configuration of parameters such as amplitude, pulse width, pulse rate, duration and electrode configuration, the invention generally will be described for purposes of illustration in the context of determining an electrode configuration. A selected subset of the electrodes located on leads 16 and the polarities of the electrodes of the subset collectively define an “electrode configuration.” The electrodes may be arranged in a standard inline lead configuration, or as a surgical paddle lead, grid, or other format. Electrode configurations refer to combinations of single or multiple cathode electrodes and single or multiple anode electrodes. Stimulation current flows between the cathodes and anodes for delivery of neurostimulation therapy. Hence, the polarities of the individual electrodes are another feature of the electrode configuration. Electrodes forming part of an electrode configuration may reside together on a single lead or on different leads. System 10 also includes a programmer 20. Programmer 20 may, as shown in FIG. 1, be a handheld computing device. Programmer 20 includes a display 22, such as a liquid crystal display (LCD) or light emitting diode (LED) display, to display information to a user. Programmer 20 may also include a keypad 24, which may be used by a user to interact with programmer 20. In some embodiments, display 22 may be a touch screen display, and a user may interact with programmer 20 via display 22. A user may also interact with programmer 20 using peripheral pointing devices, such as a stylus or mouse. Keypad 24 may take the form of an alphanumeric keypad or a reduced set of keys associated with particular functions. A clinician (not shown) or other user may use programmer 20 to program neurostimulation therapy for patient 12. In particular, the clinician may use programmer 20 to create neurostimulation therapy programs. In some embodiments, programmer 20 may be used by the patient, e.g., over an extended trial screening process. As part of the program creation process, programmer 20 allows the clinician to identify parameter configurations that enable IMD 14 to deliver neurostimulation therapy that is desirable in terms of, for example, symptom relief, coverage area relative to symptom area, and side effects. Programmer 20 may also allow the clinician to identify parameter configurations that enable IMD 14 to deliver effective neurostimulation therapy with desirable device performance characteristics, e.g., low battery consumption. In addition, techniques as described herein may used to optimize therapy over the course of use of a chronically implanted IMD, e.g., by interaction between patient 12 and a patient programmer to record efficacy observations over time. In this case, a programmer carried by the patient may incorporate some or all of the functionality attributed to programmer 20 as described herein, including functionality designed to assist in identification of parameter configurations using neural networks. Programmer 20 controls IMD 14 to test parameter configurations in order to allow a clinician to identify desirable parameter configurations in an efficient manner. As will be described in greater detail below, in some embodiments, programmer 20 selects parameter configurations to test based on an electrode configuration search algorithm, as described herein. In particular, according to such an algorithm, programmer 20 may first control IMD 14 to test one or more electrodes to identify a first electrode configuration, and then test other electrode configurations based on guidance built into the search algorithm. Other neurostimulation parameters such as amplitude, pulse width, pulse rate, and duration also may be evaluated with the electrode configuration. For example, various parameters may be observed simultaneously with observation of each electrode configuration. Alternatively, once a smaller set of electrode configurations has been identified as providing efficacy for a given baseline set of amplitude, pulse width and pulse rate, then different amplitude, pulse width and pulse rate parameters may be iteratively observed for that smaller set of electrode configurations. Duration of the delivery of neurostimulation energy also may be observed. In this manner, amplitude, pulse width, and pulse rate parameters need not be evaluated for every electrode configuration, and especially those electrode configurations that do not present a high probability of efficacy as inferred from the neural network structure. By controlling IMD 14 to test parameter configurations in an intelligent manner, programmer 20 allows the clinician to more quickly identify desirable parameter configurations, reducing the overall amount of time the clinician spends programming neurostimulation therapy for patient 12. For example, in contrast to existing neurostimulation programming systems that present electrode configurations in a random order or idiosyncratic search methodologies employed by clinicians, programmer 20 may select electrode configurations to test in a way that is more likely to enable desirable configurations to be selected earlier in the search. Consequently, the clinician may be able to end the search before all potential electrode combinations have been tested if one or more desirable configurations have already been identified, saving the amount clinician and patient time required to achieve an efficacious electrode configuration. In addition, with the invention, it may be possible to identify optimal or near optimal parameter configurations that otherwise might not be identified by the clinician. Even if the clinician elects to test all potential electrode combinations, e.g., if the electrode set is small enough to make testing all electrode configurations practical, programmer 20 may reduce the time required to identify desirable electrode configurations by automating selection of each new configuration to test. Additionally, programmer 20 may improve the search process by collecting efficacy information for each combination tested. As will be described in greater detail below, programmer 20 may present a list of electrode configurations to the clinician, ordered according to the efficacy information, allowing the clinician to more easily identify and select desirable configurations. This list of electrode configurations may be ordered and updated according to newly observed efficacy information as additional electrode configurations are evaluated. Similar techniques may be applied for other neurostimulation parameters forming part of a parameter configuration, such as amplitude, pulse width, pulse rate, and duration. In order to control IMD 14 to test electrode combinations, programmer 20 may communicate with IMD 14 via telemetry techniques known in the art. For example, programmer 20 may communicate with IMD 14 via an RF telemetry head (not shown). Information identifying desirable combinations of electrodes identified by the clinician may be stored as part of parameter configurations associated with neurostimulation therapy programs. Neurostimulation therapy programs created by the clinician using programmer 20 may be transmitted to IMD 14 via telemetry, and/or may be transmitted to another programmer (not shown), e.g., a patient programmer, that is used by patient 12 to control the delivery of neurostimulation therapy by IMD 14. FIG. 2 is a block diagram illustrating an example configuration of leads 16. In the example configuration, lead 16A includes electrodes 26A-26H, and lead 16B includes electrodes 26I-26P. Hence, each lead 16 includes eight electrodes, although a lesser or greater number of electrodes are possible. Electrodes 26A-P (collectively “electrodes 26”) may be ring electrodes. Electrodes 26 collectively form an electrode set 28 implanted within patient 12. As shown in FIG. 2, electrode set 28 includes eight electrodes on each of the two leads 16, which, as shown in FIG. 1, are implanted such that they are substantially parallel to each other and spinal cord 18 (FIG. 1), on substantially opposite sides of spinal cord 18, at approximately the same height relative to spinal cord 18, and oriented such that the distal ends of leads 16 are higher relative to the spinal cord than the proximal ends of leads 16. Therefore, the illustrated configuration of electrode set 28 may be described as a two-by-eight, side-by-side, upwardly oriented configuration. Of course, electrode set 28 is provided for purposes of example, and the invention may be applicable to other types of leads and electrode sets, including single lead electrode sets, flat paddle leads, grid arrays, and the like Such an electrode set is commonly used to provide SCS therapy. However, programmer 20 may be used to identify desirable combinations of electrodes within electrode sets that are configured in any way, and used to provide any type neurostimulation therapy. For example, a single lead including four or eight electrodes, two leads including four electrodes per lead, in-line leads, and offset leads, all of which may be oriented in any manner relative to patient 12, provide electrode set configurations that may be searched by programmer 20. In the example of FIG. 2, electrodes 26 are placed on opposite sides of the T7 vertebra 23, T8 vertebra 25 and T9 vertebra 27 of a human spine. IMD 14 (FIG. 1) may deliver neurostimulation via any combination of electrodes 26. IMD 14 may independently activate each electrode 26 of set 28 to act as a cathode or anode for a configuration, and each configuration will include at least one cathode and at least one anode. In some embodiments, it is possible that an electrode configuration may include a single electrode 26 acting as the cathode, with a can of IMD 14, i.e., the IMD housing, acting as the anode for the configuration. In an electrode configuration, electrons flow from one or more electrodes acting as anodes for the configuration to one or more electrodes acting as cathodes for the configuration. The current between anodes and cathodes stimulates neurons between and proximate to the anodes arid cathodes. Generally speaking, an electrode configuration enables desirable neurostimulation therapy when current is delivered in a direction and with an intensity sufficient to stimulate specific neurons or a sufficient number of specific neurons to alleviate a symptom without causing unacceptable side effects. Further, an electrode configuration enables desirable neurostimulation therapy when the symptom is alleviated without resorting to undesirably high pulse amplitudes. As mentioned above, programmer 20 selects individual electrodes 26 or electrode configuration to test to allow a clinician to identify desirable electrode configuration according to an electrode search algorithm. Programmer 20 may select an appropriate search algorithm based on the configuration of electrode set 28, and may select electrodes 26 or electrode configurations based on the selected search algorithm. Programmer 20 controls IMD 14 to test a selected electrode 26 or electrode combination by controlling IMD 14 to deliver neurostimulation via the selected electrode 26 or combination. In some embodiments, programmer 20 may first control IMD 14 to test one or more of electrodes 26 individually to identify the individual electrode or electrodes 26 which will act as a first cathode. In other embodiments, programmer 20 starts with a combination of selected electrodes 26. Generally, a clinician implants leads 16 in a location such that the center of electrode set 28 is proximate to an area that the clinician believes should be stimulated in order to alleviate symptoms. Therefore, programmer 20 may test electrodes 26 as the first cathode in an order such that electrodes 26 located centrally within electrode set 28, e.g., electrodes 26D-E and 26L-M illustrated in FIG. 2, are tested before peripherally located electrodes. If the clinician's estimation of the target region is inaccurate, programmer 20 will continue to test individual electrodes 26 in such an order until one of the electrodes 26 that enables desirable neurostimulation therapy when activated as the first cathode is identified. Initially locating a first cathode provides a “coarse” optimization of electrode combinations, allowing programmer 20 and the clinician to quickly identify the general area to which neurostimulation therapy should be delivered. Programmer 20 may then control IMD 14 to test electrode configurations that include the first cathode. The various electrode configurations may be tested with a common set of stimulation parameters, such as a common voltage or current amplitude, frequency, and pulse width. In some embodiments, a series of different stimulation parameters may be applied for each combination of electrodes to test not only the efficacy of electrode combinations, but also electrode combinations with particular stimulation parameters such as amplitude, frequency and pulse width. Hence, an electrode configuration may apply to the combination of electrodes forming part of the neurostimulation parameter configuration, and the parameters associated with delivery of neurostimulation energy via the electrodes, such as amplitude, pulse width and pulse rate, may form another part of the parameter configuration. Programmer 20 may control IMD 14 to try different ones of electrodes 26 as the first anode in a pair with the first cathode, and may add additional anodes and/or cathodes. In accordance with an embodiment of the invention, programmer 20 controls IMD 14 to test remaining electrodes 26 as first anodes, and additional anodes or cathodes, based on electrode configurations identified by a neural network. The neural network may be employed by programmer 20 to allow a clinician to select electrode configurations, and then program IMD 14 to deliver therapy using the selected electrode configurations. The neural network structure classifies optimum electrode configurations. The search algorithm uses the neural network structure to infer likely efficacies of possible parameter configurations, such as electrode configurations, based on the efficacies of parameter configurations already observed in the course of evaluation. The network structure can be learned from an existing set of data, or developed based on the input of a neurostimulation expert. In particular, the neural network structure may be updated based on new observations obtained for newly considered electrode configurations during the search. With the aid of the neural network, a programmer 20 provides a clinician with suggestions of electrode configurations that are likely to be efficacious given observations already obtained during the selection process. In response, the clinician may select the suggested electrode configurations next. In some cases, the selection of electrode configurations, or other parameters, may be automated in response to suggestions generated using the neural network. In other cases, the selection of the parameter configurations may require human intervention from the clinician, but be aided by the suggestions. As an illustration, an expert, such as a neurostimulation physician, may initially develop the neural network structure based on his or her knowledge of typical relationships among different electrode configurations. As actual electrode configurations are observed, however, the causal relationships may be supplemented with actual data. The actual data may be archived and used as the basis for a development of future neural network structure. In some embodiments, a plurality of different neural network structures may be developed and devised for specific applications, such as different types of neurostimulation therapy, different symptomatic regimes, different electrode structures and device capabilities, and so forth. Hence, for selection of an electrode configuration, the user may first select a neural network structure suitable for the present circumstances, and then use the selected network structure to guide the selection process. Hence, the neural network structure can be used to guide an parameter configuration optimization process by selecting, as the next configuration for the clinician to try, a configuration that is more likely to yield efficacious results, e.g., in terms of symptom relief, coverage area relative to symptom area, and side effects. In this way, the number of observations that need be made to ensure a good outcome is reduced. FIG. 3 is a block diagram illustrating an example configuration of programmer 20. A clinician or other user may interact with a processor 30 via a user interface 31 in order to identify and select electrode configurations as described herein. User interface 31 may include display 22 and keypad 24 (FIG. 1), and may also include a touch screen or peripheral pointing devices as described above. Processor 30 may also provide a graphical user interface (GUI) via user interface 31 to facilitate interaction with a clinician, technician, or other medical personnel. Processor 30 may include a microprocessor, a controller, a DSP, an ASIC, an FPGA, discrete logic circuitry, or the like. Clinician programmer 20 also includes a memory 32. Memory 32 may include program instructions that, when executed by processor 30, cause clinician programmer 20 to perform the functions ascribed to clinician programmer 20 herein. For example, processor may execute a parameter configuration search algorithm 34 stored within memory 32. In particular, processor 30 may execute an electrode configuration search algorithm to select individual electrodes 26 or electrode combinations to test to allow the clinician to identify desirable electrode combinations. Search algorithm 34 executes based on the content of a neural network structure 36, which classifies electrode configurations within electrode set 28 according to predicted efficacy. Hence, programmer 20 provides interactive guidance to a clinician during the process of optimizing implantable device parameters. In particular, programmer 20 guides the clinician by suggesting the electrode configurations that are most likely to be efficacious given the results of tests already performed during the source of an evaluation session. This is accomplished by training the neural network to classify optimum configurations based on observed examples within a session. Inputs to this neural network would include efficacy ratings from one or more electrode configurations previously tried in that session. The output is the best guess of the neural network as to the optimum configuration. This guess then becomes the suggestion for the next electrode configuration to be tried by the clinician, and rated by the clinician, patient, or both. The neural network can be trained using methods such as back-propagation from a large, existing set of example records containing data based on previous observations. An input node may be included in the neural network for each unique input configuration. The neural network provides an output layer, either a single node or a series of nodes, that encodes the possible optimum configurations. One or more hidden layers may be included in the neural network, as necessary. As will be described in greater detail below, processor 30 collects information relating to tested parameter configurations, such as electrode configurations, and stores the information in memory 32 for later retrieval and review by the clinician to facilitate identification of desirable parameter configurations. Neurostimulation therapy programs 38 created by the clinician may be stored in memory 32, and information identifying electrode configurations selected by the clinician to be utilized for one of programs 38 may be stored as part of the program within memory 32. Memory 32 may include any volatile, non-volatile, fixed, removable, magnetic, optical, or electrical media, such as a RAM, ROM, CD-ROM, hard disk, removable magnetic disk, memory cards or sticks, NVRAM, EEPROM, flash memory, and the like. Processor 30 controls IMD 14 to test selected individual electrodes 26 or electrode combinations, by controlling IMD 14 to deliver neurostimulation therapy to patient 12 via the selected individual electrodes 26 or electrode combinations via a telemetry circuit 40. Processor 30 may transmit programs 38 created by the clinician to IMD 14 via telemetry circuit 40, or to another programmer used by the patient to control delivery of neurostimulation therapy via input/output circuitry 42. I/O circuitry 42 may include transceivers for wireless communication, appropriate ports for wired communication or communication via removable electrical media, or appropriate drives for communication via removable magnetic or optical media. FIG. 4 is a diagram illustrating the structure of a neural network configured to identify optimal electrode configurations. As shown in FIG. 4, the neural network is characterized by nodes, layers and interconnections. As a specific example, consider the problem of selecting the optimum electrode bipole on a 1×8 stimulation lead. Inputs for this problem include the efficacy ratings for each possible bipole combination E01, E12, . . . , E67, where E01 represents a combination of electrode 0 and electrode 1 on the lead, E12 represents a combination of electrode 1 and electrode 2 on the lead, and so forth. In the example of FIG. 4, the polarity of the electrodes, i.e., relative placement of anode and cathode on the bipole pair, is not considered, but the system 10 can be readily adapted to support polarity determinations. For this example, system 10 singly encodes (one configuration per node) the output possibilities. A single hidden layer is included with 9 nodes, though this may not be the optimum size or number of layers in some applications. In FIG. 4, only a subset of interconnection weights are shown. In practice, however, the neural network may be fully connected, with every input node connecting to every hidden node, and every hidden node connecting to every output node. In FIG. 4, the “E” nodes (E01, E12, E23, E34, E45, E56, E67) represent input nodes, the “H” nodes (H1, H2, H3, H4, H5, H6, H7, H8, H9) represent hidden nodes, and the “O” nodes (O1, O2, O3, O4, O5, O6, O7) represent output nodes that yield suggested electrode configurations 43, 45, 47, 49, 51, 52, 55. Using the neural network structure, programmer 20 provides suggestions on which parameter configurations are most likely to be efficacious given the interconnection weights among the input nodes, hidden nodes and output nodes in the neural network. The interconnection weights may be initially learned, but then modified and updated based on results of efficacy observation tests performed during the course of an evaluation with a clinician or other user. In this manner, the neural network can be used to guide the clinician to a set of optimum parameter configurations for evaluation, reducing the number of observations that need be made to ensure a good outcome. In other words, the neural network may permit the clinician to avoid a number of electrode configurations that, based on previous experience, are unlikely to yield efficacious results. Rather, the interconnection of particular nodes with interconnection weights determined from past observations directs the clinician to electrode configurations that are more likely to produce optimum efficacy results. FIG. 5 is a flow diagram illustrating a search algorithm that is executable by a programmer to select electrode configurations. As shown in FIG. 5, the algorithm involves accessing the neural network (44), initiating the search algorithm (46), selecting a first electrode configuration (48), and observing the efficacy of the first electrode configuration (50). The efficacy may be rated positively in terms of pain relief or other therapeutic benefit, and negatively in terms of side effects of the therapy. The search capability can be implemented as a feature in an implantable device programmer 20. Following the programming of a configuration of parameters, the programmer 20 may prompt for a rating of the efficacy of that configuration. The efficacy rating can be solicited from the patient by the clinician, or entered directly by the patient. In general, efficacy refers to the balance between therapeutic benefit and undesirable side effects. As examples, efficacy ratings can be obtained by verbal feedback from the patient concerning therapeutic benefit and side effects, marking of a pain/parasthesia map, objective measurement using pain rating scales, quantification of side effects, a combination of the forgoing, or other observation techniques. The programmer 20 then uses this rating with the network model appropriate for the therapy and device type to infer the best next step. This step may then be suggested to the clinician by the programmer interface. Based on the observed efficacy and a list of optimum configurations identified by the neural network, the next electrode configuration is selected (52), either automatically or manually by the clinician. The algorithm then involves observing efficacy of that newly selected electrode configuration (54) and updating the neural network weights or interconnections to reflect the observed efficacy (56). If an applicable efficacy threshold is satisfied (58), the algorithm may terminate and add the selected electrode configuration to a stored neurostimulation program or create a new neurostimulation program (60). If the threshold is not satisfied, the process may repeat iteratively (62) until the threshold is satisfied or the clinician elects to manually terminate the algorithm. If the clinician stops the search before all possible combinations of electrodes 26 have been tested, programmer 20 may create a bracket of untested combinations that the clinician may elect to include in neurostimulation therapy programs. The bracket may consist of any number of electrode combinations, and may comprise the next n combinations that would have been tested according to the electrode combination search algorithm. By providing the clinician with a bracket, programmer 20 may allow clinician to spend less time searching for desirable electrode combinations in a subsequent programming session. Specifically, the programs created using the bracket combinations may enable desirable neurostimulation therapy similar to that provided in a program created with the most recently tested combination, and may be provided to patient 12 so that patient 12 can experiment with the bracket programs outside of the clinic. As described herein, programmer 20 controls IMD 14 to test electrode configurations combination by controlling IMD 14 to deliver neurostimulation therapy via combinations of electrodes. In addition, programmer 20 may be configured to facilitate a search for other optimum therapy parameters, thereby forming a parameter configuration. For example, the clinician or programmer 20 may select desired starting points for pulse amplitude, rate and pulse width for each electrode configuration, and programmer 20 may ramp the amplitude from the starting point at a first rate of amplitude increase using similar neural network techniques. Programmer 20 may increase the amplitude in, for example, a linear or step-wise fashion. In some embodiments, the clinician or patient 12 may control the rate of amplitude increase. The clinician or patient 12 stops the ramping of the amplitude when the stimulation causes discomfort, or other undesirable side effects. Programmer 20 may reduce the amplitude at the time the ramp is stopped by some amount, e.g., a percentage, and ramps the amplitude again in order to allow the clinician and/or patient 12 to identify the amplitude that provides the best neurostimulation therapy. This second time, programmer 20 may ramp the amplitude at a slower rate of amplitude increase in order to facilitate identification of the point where best neurostimulation is achieved. Again, in some embodiments, the clinician or patient 12 may control the amplitude. Programmer 20 stores the amplitude at the time when the best neurostimulation therapy is indicated by the clinician and/or patient 12, and rating information for the electrode combination. The clinician and/or patient 12 may provide efficacy rating information, e.g., a numerical value for one or more metrics for rating the combination, which relates to the efficacy enabled by the combination or the side effects resulting from use of the combination, or both. The clinician may use rating information and/or the amplitude values stored for each tested combination to identify desirable electrode configurations. The configurations and their associated information and values may be presented in a list that may be ordered according to the information, the values, or a combination of the two. The amplitude value may, for example, be used to distinguish between tested combinations with similar ratings based on the power that must be consumed in order for each combination to enable desirable neurostimulation therapy. Various embodiments of the invention have been described. However, one skilled in the art will appreciate that various additions and modifications can be made to these embodiments without departing from the scope of the invention. The invention may be generally applicable to any programming optimization problem in which the feedback from a configuration is available relatively quickly and within the context of the clinical programming environment. This includes the stimulation therapies for pain and movement disorders and may include other stimulation-based therapies as well. For example, although programmer 20 has been described herein as a hand-held computing device, programmer 20 may take the form of any type of computing device, such as a laptop or desktop computer, may access resources, such as memory 54, via a computer network, such as a LAN, WAN, or the World Wide Web. Further, programmer 20 may include a plurality of computing devices, which may communicate to provide the functionality ascribed to programmer 20 herein via a computer network. Although described herein as associated with and interacting with a clinician, i.e., a clinician programmer, programmer 20 may be associated with patient 12, i.e., a patient programmer. In some embodiments, patient 12 may simply interact with programmer 20 in place of the clinician for some or all of the electrode combination identification process. In other embodiments, patient 12 may perform parts of the configuration identification process without being supervised by the clinician, e.g., away from the clinic, using a patient programmer. These and other embodiments are within the scope of the following claims. | <SOH> BACKGROUND <EOH>Implantable medical devices are used to deliver neurostimulation therapy to patients to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson's disease, epilepsy, incontinence, sexual dysfunction, or gastroparesis. The implantable medical device delivers neurostimulation therapy via one or more leads that include electrodes located proximate to the spinal cord, pelvic nerves, sacrum, or stomach, or within the brain of a patient. In general, the implantable medical device delivers neurostimulation therapy in the form of electrical pulses. A clinician selects values for a number of programmable parameters in order to define a parameter configuration for the neurostimulation therapy to be delivered to a patient. For example, the clinician may select an amplitude, which may be a current or voltage amplitude, and pulse width for a stimulation waveform to be delivered to the patient, as well as a rate at which the pulses are to be delivered to the patient, and duration for which the stimulation energy is delivered. In addition, the clinician also selects particular electrodes within an electrode set to be used to deliver the pulses, and the polarities of the selected electrodes. The electrode combination and polarities may be referred to as an electrode configuration. Hence, a parameter configuration may involve a variety of parameters including electrode configuration, amplitude, pulse width, pulse rate, and duration. The process of selecting parameter configurations can be time consuming, and may require a great deal of trial and error before an optimum electrode configuration is discovered. The optimum parameter configuration may be better than other configurations in balancing clinical results and side effects experienced by the patient. This balance represents overall efficacy of a parameter configuration. The process for selecting parameter configurations can be difficult due to the combinatorial possibilities of parameters, the complexity of the underlying biophysics, and subjective and possibly inconsistent feedback from the patient concerning observed efficacy for a given parameter configuration. | <SOH> SUMMARY <EOH>In general, the invention is directed to a technique for selection of parameter configurations for a neurostimulator using neural networks. The technique may be employed by a programming device to allow a clinician to select parameter configurations, and then program an implantable neurostimulator to deliver therapy using the selected parameter configurations. A parameter configuration may define one or more parameters for delivery of neurostimulation, such as electrode configuration, amplitude, pulse width, pulse rate, or duration. For example, the parameter configurations may define electrode configurations that specify electrode combinations and polarities for an electrode set implanted in a patient. The electrode set may be carried by one or more implanted leads that are electrically coupled to the neurostimulator. In some embodiments, the parameter configurations may further define one or more parameters such as amplitudes, pulse widths, pulse rates, and durations of stimulation energy delivered by electrodes in the electrode configuration. In operation, the programming device executes a parameter configuration search algorithm to guide the clinician in the selection of parameter configurations. The search algorithm relies on a neural network that identifies potential optimum parameter configurations, such as electrode configurations within an electrode set. The neural network is trained to classify optimum parameter configurations based on observed example configurations within a programming session. The neural network structure can be trained from a set of existing parameter configuration data, and then learn in the course of evaluating new parameter configurations. In particular, the neural network may be updated based on new observations obtained for parameter configurations during the search. With the aid of the neural network, a programming device provides a clinician with suggestions of which configurations are most likely to be efficacious given observations already obtained during the selection process. In general, efficacy refers to the balance between therapeutic benefit and undesirable side effects. As examples, efficacy can be observed by verbal feedback from the patient concerning therapeutic benefit and side effects, marking of a pain/parasthesia map, objective measurement using pain rating scales, quantification of side effects, a combination of the forgoing, or other observation techniques. In one embodiment, the invention provides a method comprising selecting a first parameter configuration for a neurostimulator, observing efficacy of the first parameter configuration, and selecting a second parameter configuration for the neurostimulator from a set of additional parameter configurations identified by a neural network. In another embodiment, the invention provides a computer-readable medium comprising instructions to cause a processor to select a first parameter configuration for a neurostimulator, observe efficacy of the first parameter configuration, and select a second parameter configuration for the neurostimulator from a set of additional parameter configurations identified by a neural network. In a further embodiment, the invention provides a device comprising a processor programmed to select a first parameter configuration for a neurostimulator, observe efficacy of the first parameter configuration, and select a second parameter configuration for the neurostimulator from a set of additional parameter configurations identified by a neural network. The invention may provide a number of advantages. For example, the invention may allow a clinician to more quickly identify desirable parameter configurations such as electrode combinations, reducing the overall amount of time the clinician spends programming neurostimulation therapy for a patient. In contrast to random or idiosyncratic search techniques, a technique based on neural networks is capable of learning from the evaluation of earlier parameter configurations, and developing a network structure that is more likely to lead to an optimum configuration. In general, the invention can reduce the length of a programming session for the clinician and the patient, and support selection of optimum electrode configurations to achieve overall efficacy. In addition, with the invention, it may be possible to identify optimal or near optimal parameter configurations that otherwise might not be identified by the clinician. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. | 20040129 | 20070807 | 20050317 | 69349.0 | 0 | MALAMUD, DEBORAH LESLIE | SELECTION OF NEUROSTIMULATOR PARAMETER CONFIGURATIONS USING NEURAL NETWORK | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,767,965 | ACCEPTED | Blind rivet | There is described an expanding blind rivet assembly having a flange (3) provided with an undercut surface facing the rivet shank. A resilient cap (20) is formed with a cavity (22) having an opening surrounded by an undercut surface (23) within the cavity, so that the cap may be snap-engaged over the flange of the rivet after setting. The cap provides abrasion and corrosion protection for the flange. The cap (20) may also be provided with securing means for securing a further component to the cap (20). | 1. A blind rivet assembly comprising: a tubular shank; a radially outwardly extending flange at one end of the shank; a stem extending through the shank and having a head situated adjacent the end of the shank remote from the flange; and the flange including an undercut surface facing towards the end of the shank remote from the flange. 2. A blind rivet assembly according to claim 1, wherein the stem extends through the shank, and the head is positioned outside the shank. 3. A blind rivet assembly according to claim 1, wherein the head is positioned within a portion of the shank having an enlarged bore, at its end remote from the flange. 4. A blind rivet assembly according to claim 1, wherein the flange is circular in outline and the undercut surface is a conical edge surface of the flange. 5. A blind rivet assembly according to claim 1, wherein the flange has a peripheral rebate at its edge adjacent the shank. 6. A blind rivet assembly according to claim 5, wherein the peripheral rebate is formed by a recess in the edge region of the flange. 7. A blind rivet assembly according to claim 5, wherein the peripheral rebate is formed by a spacer component positioned in contact with the surface of the flange adjacent the shank, the spacer component having an outer diameter less than the diameter of the undersurface of the shank. 8. A blind rivet assembly according to claim 5, wherein the peripheral rebate is formed by a dished edge region of the flange. 9. A blind rivet assembly according to claim 1, further including a cap, wherein the cap is provided with a cavity for receiving the flange of the blind rivet assembly after setting, the cavity having an opening and an undercut surface surrounding the opening, the undercut surface of the cap being resiliently engageable with the undercut surface of the flange of the blind rivet assembly to retain the flange of the blind rivet assembly within the cavity. 10. A cap for use with a blind rivet assembly according to claim 1, the cap being formed from resilient material and comprising a cavity for accommodating the flange, the cavity comprising an undercut surface engageable with the undercut surface of the flange to retain the flange in the cavity. 11. A cap according to claim 10, further comprising a securing formation for attaching a further component to the cap. 12. A cap according to claim 11, wherein the securing formation comprises a pair of spaced resilient cantilever arms with opposed enlargements adjacent their free ends. 13. A cap according to claim 11, wherein the securing formation is a pipe clamp. 14. A cap according to claim 11, wherein the securing formation comprises a pair of flexible strap elements attached to the cap at one of their respective ends, the other ends of the strap elements being formed with complementary parts of a securing device for attaching the strap elements together. 15. A cap according to claim 11, wherein the securing formation is a cable tie. 16. A cap according to claim 10, further comprising a vent bore providing fluid communication between the cavity and a surface of the cap opposite the opening. 17. A cap according to claim 16, further comprising a filter mesh in the vent bore. 18. A method of attaching a second component to a fabrication comprising sheet material, comprising the steps of: providing aligned holes in two portions of sheet material; joining the sheet material portions by setting rivets in the aligned holes, the rivets comprising a tubular shank having a radially outwardly extending flange at one end and a stem extending through the shank from a head situated adjacent the end of the shank remote from the flange and the flange including an undercut surface facing towards the end of the shank remote from the flange; providing a second component with a cavity for receiving the flange of a rivet assembly after setting, the cavity having an opening and an undercut surface surrounding the opening; and resiliently engaging the undercut surface of the flange of the rivet assembly and the undercut surface of the cavity to retain the second component to the flange. | CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation of pending International Patent Application PCT/EP02/09130, filed Aug. 15, 2002 which designates the United States and which claims priority of Great Britain patent application 0120020.3, filed on Aug. 16, 2001. FIELD OF THE INVENTION The present invention relates to fastenings for sheet materials, and is particularly concerned with blind rivet fastenings. BACKGROUND OF THE INVENTION A conventional blind rivet fastening has a tubular shank with an external flange at one end, and a stem extending through the shank. A first end of the stem protrudes from the flanged end of the shank, and a second end of the stem has a head whose outer diameter corresponds to the outer diameter of the shank, and which abuts the end of the shank remote from the flange. To join two sheets of material together with the rivet, aligned holes with a diameter corresponding to the external diameter of the shank are formed in the sheets, and the shank is inserted through the aligned holes until the flange rests on one of the sheets of material. Holding the flange of the shank in this position, a tensile force is applied to the stem so that the head of the stem applies compression to the tubular shank. Depending on the geometry of the head and the shank, the head may be pulled into the shank while the wall of the shank is deformed outwardly to a greater diameter, or the head may remain at the end of the shank and the wall of the shank may buckle outwards. Tensile force is applied to the stem until, at a predetermined maximum force, the stem breaks off. The head of the stem is either retained within the shank, or may fall away after the stem breaks. SUMMARY OF THE INVENTION Blind rivets of the types described above are widely used in industry for joining components in sheet metal fabrications. Conventionally, if further components have to be fixed to a sheet metal fabrication, then additional fasteners are required to secure such components. The provision of additional fasteners adds expense to the manufacture of the fabrication, in that not only are additional components required, but additional labour is necessary for attaching the components to the assembly. An objective of the present invention is to reduce the cost of producing sheet metal fabrications, by reducing the need for additional placement of fasteners to secure secondary components to the assembly. A further objective of the present invention is to provide a means of concealing and protecting the exposed heads of blind rivets after setting. According to a first aspect of the present invention, there is provided a blind rivet assembly comprising a tubular shank having an external flange at one end, a stem extending through the shank and having a head abutting the end of the shank remote from the flange, characterised in that the flange is provided with a peripheral undercut surface facing towards the shank. A second aspect of the present invention provides a method of mounting a second component to a blind rivet after setting, the method comprising: providing a blind rivet having a tubular shank with an external flange and a peripheral undercut surface on the flange, setting the rivet so that the undercut surface of the flange faces towards a surface of the material in which the rivet is set, providing an undercut cavity in a second component into which the flange of the rivet is receivable and which includes an undercut surface engageable with the undercut surface of the flange, and snap-engaging the cavity of the second component over the flange of the rivet. The second component may be a simple protective cap to cover the flange, or may be a functional component such as a cable clamp, a wire tie, or other structure for retaining further parts to the riveted assembly. BRIEF DESCRIPTIONS OF THE DRAWINGS Embodiments of the invention will now be described with reference to the accompanying drawings, in which: FIGS. 1 to 4 are sectional side elevations of a first rivet assembly of the present invention, showing the setting sequence for the rivet assembly; FIG. 5 is a sectional side elevation showing a cap for fitting to the rivet flange; FIGS. 6 and 7 are sectional and perspective views, respectively, of a pipe clamp integrally moulded with the rivet cap; FIG. 8 is a perspective view showing two rivet flanges used to retain an elongated component; FIGS. 9 and 10 are sectional and perspective views, respectively, of a rivet with a tamper-evident cap; FIGS. 11 and 12 are sectional and perspective views, respectively, of a cable tie integrally moulded with the rivet cap; and FIGS. 13 and 14 are sectional and perspective views, respectively, of a rivet with a vented cap; FIG. 15 is a sectional view, similar to FIG. 1, of a second rivet assembly; FIG. 16 is a sectional view of a third rivet assembly according to the invention; FIG. 17 shows a sectional view of a fourth rivet assembly according to the invention; FIG. 18 is a view of the rivet of FIG. 17 set and with a cap applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, FIGS. 1 to 4 show the setting sequence for the rivet. The rivet 1 comprises a tubular shank 2 at the upper end of which (as shown in the Figures) is a radially outwardly extending flange 3. The upper surface 4 of the flange 3 is domed, and the undersurface 5 of the flange 3 is planar and perpendicular to the tubular shank 2. The outer peripheral surface 6 of the flange 3 is tapered inwardly and downwardly in this embodiment, to provide a conical surface tapering towards the lower end of the rivet 1. A stem 7 extends through the tubular shank 2 and protrudes beyond the domed surface 4 of the flange 3. The stem 7 extends longitudinally through the tubular shank 2, and has a radially enlarged head 8 whose outer diameter is substantially equal to the outer diameter of the tubular shank 2, in contact with the end of the shank 2 remote from the flange 3. The sequence of FIGS. 1 to 4 shows the use of a rivet to join together two sheets 9 and 10 of material such as sheet metal. The sheets 9 and 10 are first formed with respective bores 11 and 12, whose diameter is substantially equal to the external diameters of the head 8 of the stem 7 and of the tubular shank 2. The bores 11 and 12 are aligned, as seen in FIG. 1, and the head 8 and shank 2 of the rivet 1 are then inserted through the bores 11 and 12. The undersurface 5 of the flange 3 contacts the sheet 9 wherein the rivet 1 is fully inserted, and the peripheral surface 6 of the flange is inclined and faces towards the upper surface of the sheet 9 to form an undercut extending around the edge of the flange 3. Once the rivet 1 has been fully inserted, downward pressure is exerted on the upper surface 4 of the flange 3, and a tensile force is applied to the protruding stem 7, to draw the head 8 of the stem towards the flange 3. As shown in FIG. 3, this causes the lower end of the tubular flange to which is unsupported by the bores 11 and 12 to buckle outwardly to form an enlarged region 13, preventing removal of the rivet from the aligned holes, and drawing the two sheets 9 and 10 into close contact. When a predetermined tensile force is exceeded, the stem 7 breaks and the protruding part of the stem 7 is removed from the flange 3, as seen in FIG. 4. The stem 7 may break at a point spaced from the head 8, leaving the head 8 and a portion of the stem 7 within the shank 2, as seen in FIG. 4. Alternatively, if the stem is weakened so as to break at its junction with the head 8, the stem 7 may be entirely removed through the flange 3 and the head 8 may fall away from the end of the shank 2. FIG. 5 shows a first embodiment of the present invention. In order to protect the exposed flange 3 of the rivet 1 from abrasion and corrosion, a cap 20 is provided. The cap 20 is generally disc-like in shape, with a substantially flat upper surface 21. The undersurface of the cap 20 is formed with a cavity 22, shaped so as closely to receive the flange 3 of the rivet 1. The cavity 22 has an undercut peripheral surface 23 angled to correspond with the peripheral surface 6 of the flange 3 of the rivet 1. The cap 20 is made from resilient material such as synthetic plastics material, and is resiliently deformable so that the cap 20 may be press-fitted onto the flange 3 of the rivet 1. A sealant material may be provided within the cavity 22 to be extruded therefrom as the cap 20 is fitted to the flange 3 in order to create a hermetic seal between the cap 20 and the flange 3. Sealant material may alternatively be applied to the flange of the rivet prior to fitting the cap. The cap 20 shown in FIG. 5 has a substantially cylindrical outer peripheral wall 24. It is foreseen that the wall 24 may be tapered in the axial direction of the cap, so that the cap is substantially trunconical in form with the cavity 22 formed in the base of the truncated cone. Such an arrangement will minimise the likelihood of cables or the like snagging on the cap when used. The resilient engagement between the undercut surface 23 of the cavity 22 and the undercut surface 6 of the flange 3 retains the cap 20 onto the flange of the rivet. In order to take full advantage of this retention, a retaining or gripping structure may be integrally moulded with the cap 20 so that the rivet and cap may be used to retain a secondary component to the sheets 9 and 10 which the rivet secures together. Such a component is shown in sectional view in FIG. 6, and in perspective in FIG. 7. Referring now to FIG. 6, the cap 20 is formed with the cavity 22 to engage the flange 3 of the rivet 1, and on the upper surface 21 of the cap, a resilient clamp formation for receiving a cylindrical object such as a pipe is formed. The clamp formation comprises a pair of cantilever arms 30 and 31 whose adjacent surfaces are shaped to form a part-cylindrical passage P. A pair of angled lead-in surfaces 32 and 33 are formed at the ends of the respective arms 30 and 31. In use, the rivet 1 is first set to join together the two sheet components 9 and 10, and the cap 20 is snap-fitted to the flange 3 of the rivet 1. A cylindrical object such as a pipe is then placed on the lead-in surfaces 32 and 33 of the arms 30 and 31, and downward pressure on the pipe causes the arms 30 and 31 to flex apart due to the camming action of the lead-in surfaces on the surface of the pipe. The pipe can then pass into the passage P between the arms 30 and 31, to be retained therein by the resilient action of the arms. FIG. 8 shows an application for the rivet of the invention, wherein a plurality of rivets are aligned in the assembly and an elongate component, such as a decorative trim strip 40, is attached to the sheet metal assembly by means of an undercut groove 41. The groove 41 has a pair of undercut side surfaces 42 and 43 which engage the undercut surfaces 6 of the flanges 3 of the rivets. The trim strip 40 may be applied to the rivets by first engaging one of the side surfaces 42 with the surfaces 6 of the rivets 1, and then flexing the trim strip 40 so as to open the slot 41 to enable the flanges 3 to enter the slot. When the strip 40 is released, the surface 43 engages the surfaces 6 of the flanges of the rivets to retain the trim strip 40 in place. Alternatively the strip 40 may be aligned with the rivet flanges and slid into engagement in the longitudinal direction of the strip. In an alternative embodiment (not shown) an elongate component such as a trim strip 40 may be provided with a number of individual cavities each corresponding in size and position to the flange 3 of a rivet in the main assembly to which the strip is to be attached. The strip is then attached by aligning the cavities with their respective rivets and push-fitting the strip at each attachment location. The strip 40 is preferably a resilient plastics component, but could be a sheet metal channel section with inwardly-turned flanges at the open side of the channel to engage the undercut surfaces 6 of the flanges 3 of the rivets 1. FIGS. 9 and 10 show a further embodiment of the invention, intended to provide a tamper-evident cap for the rivet 1. As seen in cross-section in FIG. 9, the cap 20 has a thin frangible flange 50 extending radially outwardly from the peripheral surface 24 of the cap 20, substantially co-planar with the undersurface of the cap 20. The cap 20 is applied to the flange 3 of the rivet 1 as described in relation to FIG. 5, and the flange 50 is thus positioned in contact with the surface of the sheet material 9. The flange 50 may be a thin flange of plastics material moulded integrally with the cap 21, or may be a frangible material such as paper or metallic foil, bonded to the underside of the cap 20. The flange 50 may be provided with a contact adhesive on its undersurface, to secure the flange 50 to the sheet material 9 when the cap is in place. The objective of the tamper-evident cap is that the structural weakness of the flange 50 will cause the flange 50 to be deformed or ruptured if any attempt is made to remove the cap 20 from the flange 3 of the rivet 1. The tamper-evident cap may carry unique identifying indicia on either the flange 50 or the upper surface 21 of the cap. With the tamper-evident cap shown in FIGS. 9 and 10, any attempt to remove the rivet 1, such as to substitute a component of the sheet metal fabrication for a replacement, will be detectable by the destruction of the flange 50 of the tamper-evident cap. If the cap is removed and a new cap placed in its stead, the difference in the unique identifying numbers on the original cap and the replacement cap will clearly show that a substitution has been made. FIGS. 11 and 12 show a further embodiment of the invention, wherein a cable tie structure is integrally moulded with the cap 20. The cable tie structure comprises a first flexible band 55 extending radially from one side of the cap 20 and having at its free end a head 56 with a through passage 57. Within the through-passage is a ratchet tooth 58. The cable tie assembly further comprises a second flexible band portion 59 extending from a diametrically opposite side of the cap 20 to the band 55. The band portion 59 has a tapered inserting end 60, and a series of ratchet teeth 61 formed along one face of the band portion 59. The cable tie is positioned by first setting the rivet as described in relation to FIGS. 1 to 4 and then applying the cap as described in relation to FIG. 5. The flexible band portions 55 and 59 are then passed around a bundle of cables, and the insertion end 60 is passed through the passage 57 of the head 56 so that the ratchet teeth 61 of the band portion 59 sequentially engage the ratchet tooth 58 of the head 56 as the band is tightened. Engagement of the tooth 58 with one of the teeth 61 will prevent withdrawal of the band portion 59 from the passage 57, and retain the cables in a bundle. FIGS. 13 and 14 are sectional and perspective views, respectively, of a rivet wherein the stem 7 and head 8 are completely removed from the rivet during the setting process, so that the tubular shank 2 of the rivet provides fluid communication between the two faces of the sheets 9 and 10 which the rivet fixes together. To protect the flange 3 of the rivet, and to provide venting between the two faces of the sheet materials 9 and 10, a venting cap 60 is provided. The venting cap 60 is similar in form to the cap 20 shown in FIG. 5, but has a central recess in its upper surface 21 to accommodate a filter mesh 61, and has a central through hole 62 which provides fluid communication between the cavity 22 and the upper surface 21 of the cap 60. In use, the rivet is set as described as above, but the stem 7 of the rivet is weakened adjacent the head 8 so that the stem and head are completely removed when the rivet is set, leaving the tubular shank 2 of the rivet unobstructed. The vent cap 60 is snap-engaged onto the undercut surfaces 6 of the flange 3 of the rivet, as previously described. When the cap is in place, the through hole is aligned with the tubular shank 2 of the rivet 1, so that fluid communication is established between the upper and lower faces of the sheets 9 and 10 respectively. While the above embodiments of the invention include the provision of pipe clamps, cables ties, tamper-proof flanges and vent openings, it is foreseen that any suitable structure may be formed integrally with the cap 20 in order to held in place by one or more of the rivets according to the invention. The rivet of the invention thus provides a convenient means by which secondary components can be attached to a fabricated sheet metal structure, using the rivets which secure the structure together as attachment points for the secondary components. A second type of rivet according to the invention is shown in FIG. 15. While the undercut surfaces of the flange of each rivet are described and illustrated above as conical edge surfaces, in the rivet of FIG. 15 the peripheral surface 6 of the flange 3 of the rivet is formed with a rebate 61 adjacent the undersurface 5 of the flange 3, to form a radially outwardly extending flange region 3a spaced axially from the undersurface 5 of the flange 3 of the rivet to provide a clearance C between the radially-outwardly extending flange region 3a and the surface of a sheet to which the rivet is attached. In a further alternative embodiment, illustrated in FIG. 16, a conventional blind rivet having a flange 3 with a planar undersurface 5 and a cylindrical, i.e. non-undercut peripheral surface 6 may be modified by adding a spacing component 70 such as a washer to the shank of the rivet. The washer 70 is fitted over the shank 2 and contacts the undersurface 5 of the flange of the rivet. By making the outer diameter d of the washer less than the diameter D of the undersurface 5 of the flange 3, a peripheral region 5a of the undersurface of the flange forms an undercut surface when the rivet is set in a workpiece with the washer 70 in place between the flange 3 and the workpiece. In a yet further embodiment of the rivet, illustrated in FIGS. 17 and 18, the flange 3 of the rivet has its peripheral region 36 dished so that the central region of the underside 5 of the rivet contacts a workpiece in which the rivet is set, and a peripheral region 5b of the undersurface of the flange is inclined away from the workpiece in the radially outward direction. FIG. 18 shows the rivet of FIG. 17 set in aligned holes in two sheets 9 and 10 of material, securing the sheets together. In contrast to the rivets shown in FIGS. 1 to 14, the rivets of FIGS. 15 to 18 have a stem 7 with a conical head 18 tapering towards the stem 7. The head 8 of the rivet is received in a conical section of the tubular shank 2 of the rivet, so that in the unset condition (seen in FIGS. 15 to 17) the head 8 is within the end of the shank 2 remote from the flange 3. As the stem 7 is drawn upwardly (as seen in the Figures), the conical head 8 expands and deforms the tubular shank 2 of the rivet. When the head 8 reaches a point where further movement up the shank is prevented, by the sheet material 10 preventing expansion of the shank, the stem 7 breaks and the head 8 is retained in position by the elasticity of the shank material. Stem 7 is removed through the flange 3. FIG. 18 shows a set rivet with a dished flange, to which a cap 80 has been fitted. The cap 80 comprises a disc-like top 81, a depending skirt 82, and a radially upwardly extending rib 83 formed on the skirt 82. The cap 80 is formed from resilient material, so as to be sufficiently flexible to enable the cap to be snap-engaged over the flange 3 of the rivet to the position of FIG. 18, wherein the rib 83 engages the inclined undersurface 5b of the flange. In the embodiment shown, the undersurface 83a of the rib 83 is inclined to form a tapered lead-in surface, and the edge surface 6a of the flange is inclined so that when the cap 80 is first placed on the flange 3, the surfaces 83a and 6a engage to align the cap 80 and the flange 3. Pressure on the cap causes a cam action between the surfaces 6a and 83a, resiliently expanding the skirt 82 to enable the rib 83 to snap over the flange and then contract to the position shown in FIG. 18 with the upper surface of the rib 83 engaging the undersurface 5b of the flange 3. The cap 80 may be formed with securing structures or tamper evident structures, as described in relation to FIGS. 6 to 13. The rib 83 may be discontinuous, or may be a series of spaced rib portions extending on the interior surface of the skirt 82. Alternatively, the skirt 82 may be turned inwardly at its free end to provide an undercut surface to engage the undersurface 5a or 5b of the rivet flange. | <SOH> BACKGROUND OF THE INVENTION <EOH>A conventional blind rivet fastening has a tubular shank with an external flange at one end, and a stem extending through the shank. A first end of the stem protrudes from the flanged end of the shank, and a second end of the stem has a head whose outer diameter corresponds to the outer diameter of the shank, and which abuts the end of the shank remote from the flange. To join two sheets of material together with the rivet, aligned holes with a diameter corresponding to the external diameter of the shank are formed in the sheets, and the shank is inserted through the aligned holes until the flange rests on one of the sheets of material. Holding the flange of the shank in this position, a tensile force is applied to the stem so that the head of the stem applies compression to the tubular shank. Depending on the geometry of the head and the shank, the head may be pulled into the shank while the wall of the shank is deformed outwardly to a greater diameter, or the head may remain at the end of the shank and the wall of the shank may buckle outwards. Tensile force is applied to the stem until, at a predetermined maximum force, the stem breaks off. The head of the stem is either retained within the shank, or may fall away after the stem breaks. | <SOH> SUMMARY OF THE INVENTION <EOH>Blind rivets of the types described above are widely used in industry for joining components in sheet metal fabrications. Conventionally, if further components have to be fixed to a sheet metal fabrication, then additional fasteners are required to secure such components. The provision of additional fasteners adds expense to the manufacture of the fabrication, in that not only are additional components required, but additional labour is necessary for attaching the components to the assembly. An objective of the present invention is to reduce the cost of producing sheet metal fabrications, by reducing the need for additional placement of fasteners to secure secondary components to the assembly. A further objective of the present invention is to provide a means of concealing and protecting the exposed heads of blind rivets after setting. According to a first aspect of the present invention, there is provided a blind rivet assembly comprising a tubular shank having an external flange at one end, a stem extending through the shank and having a head abutting the end of the shank remote from the flange, characterised in that the flange is provided with a peripheral undercut surface facing towards the shank. A second aspect of the present invention provides a method of mounting a second component to a blind rivet after setting, the method comprising: providing a blind rivet having a tubular shank with an external flange and a peripheral undercut surface on the flange, setting the rivet so that the undercut surface of the flange faces towards a surface of the material in which the rivet is set, providing an undercut cavity in a second component into which the flange of the rivet is receivable and which includes an undercut surface engageable with the undercut surface of the flange, and snap-engaging the cavity of the second component over the flange of the rivet. The second component may be a simple protective cap to cover the flange, or may be a functional component such as a cable clamp, a wire tie, or other structure for retaining further parts to the riveted assembly. | 20040128 | 20070220 | 20050113 | 57253.0 | 0 | SAETHER, FLEMMING | BLIND RIVET | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,767,980 | ACCEPTED | System and method for security processing media streams | A system for multi-stream security processing and distributing digital media streams includes a headend, a network, and at least one receiver. The headend is generally configured to generate encrypted digital media streams. The network may be coupled to the headend and configured to receive the encrypted digital media streams. The at least one receiver may be coupled to the network and configured to receive the encrypted digital media streams and present a decrypted version of the encrypted digital media streams. At least one of the headend and the at least one receiver include a security processor that may be configured to provide at least one of simultaneous multiple encryption and simultaneous multiple decryption processing of the digital media streams. | 1. A system for multi-stream security processing and distributing digital media streams, the system comprising: a headend configured to generate encrypted digital media streams; a network coupled to the headend and configured to receive the encrypted digital media streams; and at least one receiver coupled to the network and configured to receive the encrypted digital media streams and present a decrypted version of the encrypted digital media streams, wherein at least one of the headend and the at least one receiver comprises a security processor configured to provide at least one of simultaneous multiple encryption and simultaneous multiple decryption processing of the digital media streams. 2. The system of claim 1 wherein the media streams are at least one of a video stream, and audio stream, and a video plus audio stream. 3. The system of claim 1 wherein the security processor comprises a plurality of digital stream encryption/decryption engines that are selectively parallel coupled by a controller for simultaneous operation in response to a predetermined security configuration. 4. The system of claim 3 wherein the security configuration comprises at least one of Data Encryption Standard (DES), Triple DES (3-DES), Advanced Encryption Standard (AES), and Common Scrambling Algorithm (CSA). 5. The system of claim 3 wherein the security configuration comprises at least one of a secure download, RSA key management, multiple security key management, authentication, copy protection, and digital signatures. 6. The system of claim 3 wherein the security processor further comprises at least one of a memory containing a hash, engine encryption/decryption configuration logic, a random number generator, a multiplier, and a memory containing a dynamic feedback arrangement scrambling technique (DFAST) algorithm coupled in parallel to the controller and configured to provide multiple key management for at least one of conditional access and digital rights management. 7. The system of claim 3 wherein the security processor further comprises at least one of a swappable random access memory (RAM) and a swappable flash memory containing the predetermined security configuration. 8. The system of claim 3 wherein the security processor provides role-based authentication that is used by an authorized user for at least one of configuration, reconfiguration, and renewal. 9. The system of claim 1, wherein the receiver is at least one of a set top box (STB), and a receiver or transceiver for at least one of digital televison, high definition digital television (HDTV), audio, MP3, text messaging, and game digital streams. 10. The system of claim 1, wherein the receiver is a set top box (STB) and the system further comprises an additional receiving device including the security processor, coupled to the STB and configured to receive and decrypt the encrypted digital media streams using the security processor. 11. A method of multi-stream security processing and distributing digital media streams, the method comprising: generating encrypted digital media streams at a headend; coupling a network to the headend and receiving the encrypted digital media streams at the network; and coupling at least one receiver to the network and receiving the encrypted digital media streams at the receiver, and presenting a decrypted version of the encrypted digital media streams using the receiver, wherein at least one of the headend and the at least one receiver comprises a security processor configured to provide at least one of simultaneous multiple encryption and simultaneous multiple decryption processing of the digital media streams. 12. The method of claim 11 wherein the media streams are at least one of a video stream, and audio stream, and a video plus audio stream. 13. The method of claim 11 wherein the security processor comprises a plurality of digital stream encryption/decryption engines that are selectively parallel coupled by a controller for simultaneous operation in response to a predetermined security configuration. 14. The method of claim 13 wherein the security configuration comprises at least one of Data Encryption Standard (DES), Triple DES (3-DES), Advanced Encryption Standard (AES), and Common Scrambling Algorithm (CSA). 15. The method of claim 13 wherein the security configuration comprises at least one of a secure download, RSA key management, multiple security key management, authentication, copy protection, and digital signatures. 16. The method of claim 13 wherein the security processor further comprises at least one of a memory containing a hash, engine encryption/decryption configuration logic, a random number generator, a multiplier, and a memory containing a dynamic feedback arrangement scrambling technique (DFAST) algorithm coupled in parallel to the controller and configured to provide multiple key management for at least one of conditional access and digital rights management. 17. The method of claim 13 wherein the security processor further comprises at least one of a swappable random access memory (RAM) and a swappable flash memory containing the predetermined security configuration. 18. The method of claim 11 further comprising: presenting the encrypted digital media streams from the receiver; and coupling an additional receiving device including the security processor to the receiver and receiving and decrypting the encrypted digital media streams at the receiving device using the security processor. 19. The method of claim 11 wherein the security processor provides role-based authentication that is used by an authorized user for at least one of configuration, reconfiguration, and renewal. 20. For use in a system for multi-stream security processing and distributing digital media streams, a security processor configured to provide at least one of simultaneous multiple media stream decryption and encryption processing, the security processor comprising: a controller; and a plurality of digital stream encryption/decryption engines that are selectively parallel coupled by the controller for simultaneous operation in response to a predetermined security configuration. 21. The security processor of claim 20 wherein the media streams are at least one of a video stream, and audio stream, and a video plus audio stream. 22. The security processor of claim 20 wherein the security configuration comprises at least one of Data Encryption Standard (DES), Triple DES (3-DES), Advanced Encryption Standard (AES), and Common Scrambling Algorithm (CSA). 23. The security processor of claim 20 wherein the security configuration comprises at least one of a secure download, RSA key management, multiple security key management, authentication, copy protection, and digital signatures. 24. The security processor of claim 20 wherein the security processor further comprises at least one of a memory containing a hash, engine encryption/decryption configuration logic, a random number generator, a multiplier, and a memory containing a dynamic feedback arrangement scrambling technique (DFAST) algorithm coupled in parallel to the controller and configured to provide multiple key management for at least one of conditional access and digital rights management. 25. The security processor of claim 20 wherein the security processor further comprises at least one of a swappable random access memory (RAM) and a swappable flash memory containing the predetermined security configuration. 26. The security processor of claim 20 wherein the system for multi-stream security processing and distributing digital media streams comprises a headend, a network electrically coupled to the headend, a set top box (STB) coupled to the network, and a receiver coupled to the STB, and the security processor is implemented in connection with at least one of the headend, the network, the STB, and the receiver. 27. The security processor of claim 20 wherein the security processor provides role-based authentication that is used by an authorized user for at least one of configuration, reconfiguration, and renewal. 28. The security processor of claim 20 wherein the security processor is implemented in connection with a receiver or a transceiver that is at least one of a set top box (STB), and a receiver or transceiver for at least one of digital televison, high definition digital television (HDTV), audio, MP3, text messaging, and game digital streams. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system and a method for security processing media streams. 2. Background Art Conventional implementations of media (e.g., video, audio, video plus audio, and the like) program stream delivery systems(e.g., cable, satellite, etc.) include a headend where the media programming originates (i.e., is encoded and compressed, groomed, statmuxed, and otherwise appropriately processed), a network (e.g., cable or satellite) for delivery of the media programming to the client (i.e., customer, user, buyer, etc.) location, at least one set top box (STB) at the client location for conversion (e.g., decryption and decompression) of the media programming stream, and at least one respective viewing device such as a television (TV) or monitor that is connected to the STB. Conventional headends and STBs employ particular matching encryption/decryption and compression/decompression technologies. However, there is little standardization of particular matching encryption/decryption across media program stream delivery system vendors. The encryption/decryption and compression/decompression technologies in the particular conventional system are fixed and often proprietary to the vendor. Furthermore, conventional media service processing and delivery systems typically implement security processes in connection with individual implementations of point of deployment, CableCard, Smartcard, etc. systems. Transitions to upgrades in encryption/decryption and compression/decompression technologies are, therefore, expensive and difficult for the media program stream delivery system vendors to implement. As such, customers can be left with substandard service due to the lack of standardization and the reduced competition that the lack of standardization has on innovation in media service delivery. The lack of standardization also restricts the ability of media service providers to compete. For example, customers may have viewing devices that could take advantage of the improved technologies, however, media stream delivery system upgrades may be impossible, impracticable, or not economically feasible for vendors using conventional approaches. A significant level of customer dissatisfaction may result. As a result, it would be desirable to have an improved system and method for security processing media streams that addresses the above indicated problems with conventional approaches as well as providing additional improvements. SUMMARY OF THE INVENTION The present invention generally provides an improved system and method for security processing digital media streams. The improved system and method for security processing media streams of the present invention may be compatible with previously used (i.e., legacy) systems and methods using all levels of media stream processing and delivery service (i.e., basic to high-end) as well as adaptable to future implementations, and that is flexible, renewable, re-configurable, and supports simultaneous multiple security systems and processes. According to the present invention, a system for multi-stream security processing and distributing digital media streams is provided. The system comprises a headend, a network, and at least one receiver. The headend may be configured to generate encrypted digital media streams. The network may be coupled to the headend and configured to receive the encrypted digital media streams. The at least one receiver may be coupled to the network and configured to receive the encrypted digital media streams and present a decrypted version of the encrypted digital media streams. At least one of the headend and the at least one receiver comprises a security processor that may be configured to provide at least one of simultaneous multiple encryption and simultaneous multiple decryption processing of the digital media streams. For example, in one implementation the headend may utilize the security processor of the present invention to encrypt the digital media streams and the one or more receivers may use a conventional approach to decrypt the digital media streams. In another example, the headend may utilize a conventional approach to encrypt the digital media streams and one or more of the receivers may use the security processor of the present invention to decrypt the digital media streams. In yet another example, the headend may utilize the security processor of the present invention to encrypt the digital media streams and one or more of the receivers may use the security processor of the present invention to decrypt the digital media streams. In all of the implementations, the headend generally encodes, compresses, grooms, statmuxs, and otherwise appropriately processes the digital media streams. The receivers may, in one example, be implemented as set top boxes (STBs). In other examples, the receiver (receiving device) may be implemented as a television, high definition television (HDTV), monitor, host viewing device, MP3 player, audio receiver, radio, personal computer, media player, digital video recorder, game playing device, etc. Also according to the present invention, a method of multi-stream security processing and distributing digital media streams is provided. The method comprises generating encrypted digital media streams at a headend. The method further comprises coupling a network to the headend and receiving the encrypted digital media streams at the network. The method yet further comprises coupling at least one receiver to the network and receiving the encrypted digital media streams at the receiver, and presenting a decrypted version of the encrypted digital media streams using the receiver. At least one of the headend and the at least one receiver comprises a security processor that may be configured to provide at least one of simultaneous multiple encryption and simultaneous multiple decryption processing of the digital media streams. Further, according to the present invention, for use in a system for multi-stream security processing and distributing digital media streams, a security processor configured to provide at least one of simultaneous multiple media transport stream decryption and encryption processing is provided. The security processor comprises a controller and a plurality of digital stream engines. The digital stream engines may be selectively parallel coupled by the controller for simultaneous operation in response to a predetermined security configuration. The above features, and other features and advantages of the present invention are readily apparent from the following detailed descriptions thereof when taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram a media stream security processor of the present invention; FIG. 2 is a diagram of a media processing and delivery system implementing the present invention; and FIG. 3 is a diagram of another media processing and delivery system implementing the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) With reference to the Figures, the preferred embodiments of the present invention will now be described in detail. In one example, the improved system and method for security processing digital media streams (e.g., media streams that include video, audio, video plus audio, and the like in any appropriate format or protocol such as Motion Picture Expert Group (MPEG), MPEG-2, MPEG-4, Windows Media 9, Real Media, etc. streams) of the present invention may be implemented in connection with a cable (or satellite) television delivery system. However, the present invention may be implemented in connection with any appropriate media stream delivery system to meet the design criteria of a particular application. The present invention may dis-aggregate (i.e., separate, break apart, etc.) content security algorithms (i.e., routines, processes, operations, etc.) that are typically proprietary from the respective infrastructure components (e.g., media stream delivery system headend components and set top boxes (STBs), and the like). The dis-aggregation provided by the present invention may dramatically lower the cost for infrastructure owners (e.g., media stream delivery system vendors, providers, operators, etc.) to switch (i.e., change, migrate, transition, evolve, upgrade, shift, modify, etc.) between different content security systems and methods. The dis-aggregation may provide for the manufacture and distribution of digital media stream delivery devices that are compatible with past (or legacy), present and future infrastructure, regardless of specific content security systems and methods that are used in the infrastructure. The dis-aggregation provided by the present invention may include dis-aggregation of security features that generally use hardware re-configuration from the security features that can be renewed in software. The present invention may provide more efficient manufacturing and distribution, and may enable new business models, including the retail availability of extremely low cost customer premises equipment (CPE, such as STBs, host digital devices, etc.). The present invention may provide flexibility to enable infrastructure transitions between different content security systems and method, including transitions from ‘legacy’ (i.e., past or previous implementation, earlier generation, backward compatible with older, etc.) systems that generally use proprietary content security. The present invention may provide for ease in introducing new conditional access systems (CASs) into a media stream vendor (provider) network that has legacy hardware and software. The transition time and expense of performing a transition to a new CAS can be extremely prohibitive using conventional approaches particularly when the transition should be performed in a short time period. The present invention may provide the multisystem operator (MSO) (i.e., the media stream provider) the ability to support legacy systems and make a transition to a new CAS or to an alternative proprietary CAS, as desired, thereby making a more smooth and cost effective transition that may be amortized over a longer time period. The present invention may also provide media stream processing and delivery service providers the ability to transition from any rights management system or process to any appropriate CAS. The present invention may provide a renewable and re-configurable security system and method that may be used to encrypt content and services in a cable headend (e.g., servers, processors, etc.). The present invention may also be used to decrypt content and services in the receiving devices (e.g., STBs, viewing devices, etc.). The present invention may provide flexible support for encryption and decryption of multiple CASs, Digital Rights Management, and the like. The present invention may provide support for authentication of devices. The present invention generally provides novel and improved concepts in renewability and hardware re-configuration for conditional access and digital rights management systems. The present invention may use a highly secure role-based authentication process (i.e., method, routine, steps, blocks, operation, etc.) to configure and renew the overall security system, and security key (i.e., code, authorization, etc.) management techniques. The role-based authentication of the present invention may provide a logon to the security processor to enable access to certain functions as a user for media stream decryption and encryption. In the same way, the role-based authentication of the present invention generally enables an Administrator, Supervisor, or other authorized user to logon with a different password or key to enable the configuration, re-configuration, and renewability of the software and hardware. The present invention may be used to decrypt any appropriate media streams in home STB, host digital television devices, and the like. The present invention may support encryption and decryption of legacy (i.e., past, prior, previously implemented, etc.) CASs, a digital video broadcasting-common scrambling algorithm (DVB-CSA) CAS system, Digital Rights Management, and the like for video, audio, video plus audio, etc., and for newly developed CASs. The commercial value of the present invention may be very large since the present invention may enable all of the consumer electronics industry to innovate new types of products for MSOs, and all media stream processing and delivery equipment companies are potential customers for the present invention. The present invention may lower the overall cost of producing STBs and digital televisions, thereby providing significant cost and time savings to the MSOs and customers of the MSOs. By providing dramatically lower costs as well as increased innovation and new business models, the present invention may provide the user significant commercial advantages when compared to conventional approaches. The present invention generally provides an improved system and method to securely configure, renew, and re-configure (using role-based authentication) an encryption/decryption apparatus to support both proprietary, legacy CASs, other proprietary CAS implementations (e.g., apparatuses from vendors such as NDS, Nagravision, Irdeto, Canalplus, etc.), DVB-CSA implementations, and one or more CAS systems using novel and unique transport encryption algorithms and novel and unique security key management techniques. The present invention generally provides novel concepts in the ability to securely configure, renew, and re-configure media stream distribution system products to support both proprietary, legacy conditional access systems (CASs), other proprietary CAS implementations (e.g., NDS/Nagravision, Irdeto, Canalplus, DVB-CSA implementations, etc.), and one or more new CAS systems using new transport encryption algorithms and new key hierarchy techniques. In contrast, conventional systems and methods for digital media stream security typically are implemented using a single, proprietary system that is expensive and difficult to change (e.g., upgrade, modify, transition, evolve, replace, etc.). Referring to FIG. 1, a diagram illustrating a media stream system (i.e., processor, apparatus, circuit, transceiver, etc.) 100 of the present invention is shown. The system 100 may be implemented in connection with a digital media stream distribution system (described in more detail in connection with FIG. 2). The system 100 is generally implemented as a security processor (or processing system) that provides at least one security feature (e.g., encryption, decryption, authentication, security key management, copy protection, digital rights management, etc.) to at least one digital media input/output stream. The system 100 may be implemented as a security processor that may be configured to provide at least one of simultaneous multiple encryption and simultaneous multiple decryption processing of the digital media streams. The system 100 generally comprises a security processor 102, a random access memory (RAM) 104, and a flash memory 106. The RAM 104 and the flash 106 are generally implemented as secure (i.e., intruder resistant) memories. In one example, the RAM 104 and the flash 106 may be implemented external to the processor 102. Such an implementation may provide easy physical access for changing the RAM 104 and the flash 106 in implementations where such a feature is desired. The processor 102 may have an input 110 that may receive a stream (e.g., IN), an output 112 that may present (i.e., transmit, broadcast, send, etc.) a stream (e.g., OUT), an input/output 114 that may couple (i.e., connect, hook up, wire, interface, etc.) the processor 102 and the RAM 104, an input/output 116 and an input/output 118 that each may couple the processor 102 and a headend (described in connection with FIG. 2), and an input/output 120 that may couple the processor 102 and the flash 106. The streams IN and OUT may be implemented as digital media streams that may be in an encrypted or in a clear (i.e., unencrypted or decrypted) state. The streams IN and OUT are each generally implemented as a digital media signal stream (e.g., an MPEG, MPEG-2, etc. stream or other transport stream). In one example, the stream OUT may be implemented as a decrypted (and decompressed) version of the stream IN. In another example, the stream OUT may be implemented as an encrypted (and compressed) version of the stream IN. In yet example, the streams OUT and IN may both may be implemented as a encrypted (and compressed) streams. However, the streams IN and OUT may be implemented having any appropriate format and protocol to meet the design criteria of a particular application. The input/output 116 may be configured to perform interfacing between the headend (e.g., headend 202 of FIG. 2) and the processor 102 that corresponds to (or is related to) firmware downloads that are authenticated. The input/output 118 may be configured to perform interfacing between the headend and the processor 102 that corresponds to (or is related to) configuration and key loading that is authenticated. The security processor 102 generally comprises an engine 130 (described in more detail below), an automatic resource (or re-hosting) manager (ARM) processor (or controller) 132, transport stream encryption/decryption engine configuration logic 134, secure RAM 136, read only memory (ROM) 138, and at least one of a random number generator 150, a hardware multiplier 152, a dynamic feedback arrangement scrambling technique (DFAST) algorithm 154 (i.e., a RAM or ROM that contains the appropriate algorithm), and a hash generation algorithm 156 (e.g., a SHA-1, an MD5, and the like) algorithm (i.e., a RAM or ROM that contains the appropriate algorithm). The engine 130 is generally implemented as a digital media stream encryption/decryption engine. The stream engine 130 may receive the stream IN and present the stream OUT. The engine 130 is generally coupled (i.e., connected, wired, hooked up, interfaced, etc.) to the controller 132 and the logic 134. The engine 130 generally comprises at least one digital media stream encryption/decryption engine 140 (e.g., engines 140a-140n). When multiple devices 140 are implemented, the engines 140 are generally configured to be coupled in parallel. The engines 140 are generally selectively parallel coupled by the controller 132 in response to a predetermined security configuration. The ARM processor (or controller) 132 may be coupled to the logic 134, the RAM 136, the firmware 138, the generator 150, the multiplier 152, the DFAST algorithm 154, and a hash generation algorithm 156. The RAM 104 and the flash 106 are generally coupled to the ARM processor 132. The RAM 104 and the flash 106 may be implemented to provide secure, readily swappable upgrades to the system 100. The controller 132 generally controls the operation of the system 100 in response to at least one (one or more) algorithms (e.g., routines, methods, processes, steps, blocks, procedures, etc. of the predetermined security configuration) that may be stored (i.e., saved, held, etc.) in at least one of the RAM 104, the flash 106, the logic 134, the RAM 136, the ROM 138, the generator 150, the multiplier 152, the DFAST algorithm 154, and the hash 156, as well as internally in connection with the processor 132. The ARM processor (or controller) 132 generally provides for secure downloads, RSA (named after the three inventors—Ron Rivest, Adi Shamir and Leonard Adleman) key management, multiple key management, digital signatures, and the like, and may include transport stream encryption/decryption logic. The devices (e.g., the logic 134, the RAM 136, the ROM 138, the generator 150, the multiplier 152, the algorithm 154, the hash 156, etc.) may be coupled in parallel. The controller 132 generally couples and controls the appropriate engine or engines 140 and the other devices (e.g., the logic 134, the RAM 136, the ROM 138, the generator 150, the multiplier 152, the algorithm 154, the hash 156, etc.) to meet the design criteria (i.e., the predetermined, desired security configuration) of a particular application. The system 100 architecture may be defined in terms of a set of security elements (SEs, e.g., interconnection and interaction of the stream engines 140, the logic 134, the RAM 136, etc. as controlled via the processor 132) and descriptions of how the SEs are used (i.e., implemented, employed, utilized, etc.) to meet design criteria of particular applications. The system 100 may provide transport media stream security service for a range of security environments from the most basic in which the only service is a low-end digital video service, to a multi-play high end environment with digital video, digital recording, data, and multimedia services. The system 100 generally provides elements that may be configured in parallel (e.g., the engines 140, etc.), to encrypt a series of security streams (e.g., the stream IN when implemented in connection with a headend) that are sent out to the network (e.g., the stream OUT) and also (e.g., when implemented in connection with a STB or host device) be used to decrypt services (e.g., the stream IN) on a single end-user device for subscriber services (e.g., a clear, decrypted, viewable version of the stream OUT). A so-called “hash” is generally a function (or process) that converts an input (e.g., the input stream, IN) from a large domain into an output in a smaller set (i.e., a hash value, e.g., the output stream, OUT). Various hash processes differ in the domain of the respective input streams and the set of the respective output streams and in how patterns and similarities of input streams generate the respective output streams. Data Encryption Standard (DES) is a fixed-key-length security algorithm that employs 56-bit length keys. Any 56-bit number can be implemented as a DES key. The relatively short key length renders DES vulnerable to brute-force attack wherein all possible keys are tried one by one until the correct key is encountered (i.e., the key is “broken”). In one example, the engine 140a may be implemented as a DES/3-DES stream engine that operates via (i.e., through, using, etc.) a legacy system Cipher Block Chaining (CBC) mode. The legacy CASs use 56-bit DES in CBC mode for the MPEG-2 transport security. The legacy system also uses DFAST scrambling on the DES CBC initialization vector as well as certain DES keys. Triple DES (3-DES) (i.e., application of DES encryption three times using three different keys) is also used to protect certain structures and the key inside entitlements. The legacy CAS also sends an increment value in the Out Of Band (OOB) channel that is used mathematically with a content key to generate a final DES working key for encrypting or decrypting the MPEG stream packets. The working key is generally changed on a variable frequency as set (i.e., predetermined, selected, etc.) by the headend. In one example, the engine 140b may be implemented as a DES/3-DES stream engine that operates via an alternative legacy system Electronic Code Book (ECB) mode. The alternative legacy CAS uses a 56-bit DES in ECB mode for the MPEG-2 transport security. The alternative legacy CAS also uses triple DES encryption on the DES keys and to protect entitlements. The alternative legacy CAS also sends a value in the OOB channel that is used mathematically with the content key to generate a final DES working key for encrypting or decrypting the MPEG stream packets. The working key is generally changed on a variable frequency that is predetermined by the headend. In one example, the engine 140c may be implemented as an OpenCable (SCTE-41) Copy Protection mode stream engine that uses 56-bit DES in ECB) mode for the MPEG-2 transport security. The OpenCable (SCTE-41) Copy Protection also uses a variation of the CAS DFAST scrambling on the DES keys, which are calculated and sent across the CableCARD interface to the host device. The DES Copy Protection key that is used in connection with the OpenCable (SCTE-41) Copy Protection is generally changed on a variable period, and the variable period is generally predetermined by variables in the CableCARD. In one example, an engine 140 (not shown) may be implemented as a CAS DES mode digital video stream security processing engine. The CAS DES mode may implement a standard (i.e., existing, currently implemented, etc.) algorithm for encryption such as DES ECB. The methods used to manage and verify the entitlements may be standardized such that multiple media service vendors are enabled to produce the corresponding system 100. The corresponding unit key for entitlement management messages (EMMs), category keys, content keys and a working key may be generated. Predetermined information (e.g., a random number, a system seed key, a vendor selected code, etc.) may be mathematically paired with the keys to provide protection for the overall security of the system 100 and the predetermined information may be standardized for the system 100. In one example, the engine 140d may be implemented as a unique and novel advanced encryption standard (AES) mode stream engine that uses the standard AES algorithm for transport decryption and encryption. The methods used to manage and verify the entitlements may be standardized so that multiple media. service vendors are enabled to produce the corresponding system 100. Predetermined techniques (e.g., methods, routines, steps, processes, algorithms, etc.) may be implemented to generate the unit key for EMMs, category keys, content keys and a working key. Predetermined information (e.g., a vendor selected code) may be mathematically paired with the keys to provide protection for the overall security of the system 100 and the predetermined information may be standardized for the system 100. In another example, an engine 140 (not shown) may be implemented as a Copy Protection/Digital Video Recorder (DVR) mode stream engine. The OpenCable (SCTE-41) Copy Protection system may be modified to support AES and the existing DES encryption algorithm for the DVR and Copy Protection security. The OpenCable (SCTE-41) Copy Protection uses a variation on the CAS DFAST scrambling on the DES keys, which are calculated and sent across the CableCARD interface to the respective host device. When AES is used as an alternative algorithm, the 128-bit key can be scrambled by the DFAST algorithm and sent from the CableCARD to the host device. AES is generally a much more secure algorithm to use for the storing of digital content in a digital video recording when compared to DES and therefore may be preferable for DVR applications. In one example, the engine 140e may be implemented as a Common Scrambling Algorithm (CSA) stream engine. The engine 140e may be implemented using a DVB-CSA Standard Mode as implemented by vendors such as NDS and Nagravision. DVB-CSA CASs use a 40-bit CSA for the MPEG-2 transport security. DVB-CSA also uses triple DES encryption for the CSA keys. DVB-CSA CASs also use a value that is combined mathematically (e.g., via the multiplier 152) with the content key to generate a final CSA working key for encrypting or decrypting the MPEG stream packets. The working key is generally changed on a variable frequency that is predetermined by the headend. In another yet example, an engine 140 (not shown) may be implemented as a unique and novel CAS CSA mode stream engine. The CAS CSA mode may use the standard CSA algorithm for transport encryption and decryption. The methods used to manage and verify the entitlements may be predetermined and standardized such that multiple vendors may produce and support the system 100. Predetermined techniques may be implemented to generate the unit key for EMMs, category keys, content keys and a respective working key. Predetermined information (e.g., user selected codes) may be mathematically paired with these keys to protect the overall security of the new CAS systems and the predetermined information may be standardized for the system 100. In one example, the engine 140n may be implemented as a Digital Rights Management (DRM) digital media stream engine. The present invention may provide a system and a method for a DRM stream and license file processing using at least one standard algorithm (e.g., DES, AES, CSA, etc.) for transport encryption and decryption. The methods used to manage and verify the entitlements in the rights licenses may be predetermined and standardized such that multiple vendors may produce and support the system 100. Predetermined techniques may be implemented to generate the unit key for the rights entitlements (i.e., license files). The implementations of category keys, content keys and the working key are not typically part of the standard DRM solution. Predetermined information (e.g., user selected codes) may be mathematically paired with the keys to provide protection for the overall security of the DRM solution of the present invention and the information may be standardized. The DRM solution implemented using the present invention may be configured to support various DRM security implementations including, but not limited to, Windows DRM and Real Networks DRM. In one example, to improve performance, a number of features implemented via the security processor 100 may be implemented in hardware (e.g., the configuration logic 134). The respective hardware is generally re-configurable instead of software renewable. For instance, the extraction of the content key from the entitlement control message (ECM) and the modification performed on the content key may be implemented in hardware to provide improved performance (e.g., faster processor 100 operation, better reliability, etc.). The content key configuration is generally used for all of the transport decryption engines defined in the security system 100 to load the final working keys. When implemented in hardware, the configuration logic generally provides support to mathematically pair the content key with the modifier value, at a predetermined frequency using a predefined mathematical function. The mathematical functions that may be implemented in connection with the security system 100 (e.g., via the multiplier 152) generally include Boolean XOR, Simple Add, Multiply, and any other appropriate functions to meet the design criteria of a particular application. The present invention may provide for securely upgrading all or part of the various software components of key management logic via renewable software (e.g., software that is implemented in connection with the RAM 104, the flash 106, RAM 136, the ROM 138, etc.). The present invention may process and validate unit keys via unit key logic. The unit key logic may be protected in the security architecture of the system 100 (e.g., secure RAM 104, secure flash 106, etc.). When a respective remote device (not shown) completes a logon process (described below), the unit key logic may be upgraded in a secure manner using a signed code image to protect the integrity of the upgrade. The present invention may provide for securely processing and validating EMMs via EMM Logic. The EMM logic is generally protected in the security architecture of the system 100. When the remote device completes the logon process, the EMM logic may be upgraded in a secure manner using a signed code image to protect the integrity of the upgrade. The present invention may provide for securely processing and validating category keys via category key logic. The category key logic is generally protected in the security architecture of the system 100. When the remote device completes the logon, the category key logic may be upgraded in a secure manner using a signed code image to protect the integrity of the upgrade. The present invention may provide for securely processing and validating an entitlement control message (ECM) via ECM key logic. The ECM key logic is generally protected in the security architecture of the system 100. When the remote device completes the logon, the ECM key logic may be upgraded in a secure manner using a signed code image to protect the integrity of the upgrade. The present invention may provide for securely processing and validating the working keys via working keys logic. The working keys logic is generally protected in the security architecture of the system 100. When the remote device completes the logon, The working keys logic may be upgraded in a secure manner using a signed code image to protect the integrity of the upgrade. The system 100 generally supports at least one of highly secure and authenticated configuration, re-configuration, and renewability using role-based authentication. At least one of configuration, renewability, and re-configuration of the present invention is generally performed after a remote authentication occurs. A logon request is generally made from the headend to perform the configuration change via a cryptographic ignition key split (CIK). The CIK generally permits the headend to login to the system 100 in a supervisor role. When the login is completed, the re-configuration request is generally performed from the data sent in the corresponding message. When the login is completed successfully, software downloads may be performed to upgrade key logic or to modify hardware configurations of the transport decryption. When the configuration, renewal and re-configuration are complete, the headend may present a logoff request. The present invention generally provides for authentication via a number of processes. For RSA key management and generation, the system 100 may generate a predetermined bit-width (in one example, up to 4096-bit, however, any appropriate bit-width may be implemented) RSA keys and securely storing the private key for use in digital signatures. The system 100 processor (e.g., the processor 132) may generate digital signatures securely without exposing the respective private key. The system 100 may verify digital signatures on signed messages and certificates received for authentication. The present invention generally provides for generating SHA-1 hash values and for generating Message Digest 5 (MD5) hash values for use in digital signatures (e.g., via the hash generator 156). The present invention generally provides for generation of and verification of digital signatures (e.g., via the ARM processor 132). Public key signatures for the present invention may be generated and verified using the RSA signature algorithm described in FIPS-PUB 180-1, “Secure Hash Standard”. The present invention generally provides for generation of and verification of standard and virtual public key infrastructure/information (PKI). The present invention generally provides support for a predetermined number (e.g., up to a 4 tier, greater than 4 tier, etc.) of standard PKI chain of X.509 certificates. The present invention generally provides support for the secure storage and usage of one RSA private key up to 4096-bits in size. However, any appropriate size may be implemented to meet the design criteria of a particular application. Virtual PKI is a method in which certificates are not installed from a true external PKI chain. Data elements for the Validity Period, the CA certificate, the Distinguished Name and the related extensions may be sent to the system 100 at initialization time. The present invention generally processes the data elements to digitally sign certificates internally for use in later authentication purposes on a network. Certificate validation generally includes validation of a linked chain of certificates from the end entity certificates to a valid Root. For example, the signature on the device certificate is verified with the Issuing CA Certificate and then the signature on the manufacturer CA certificate is verified with the Root CA certificate. The Root CA certificate is generally self-signed and the Root CA certificate is generally received from a trusted source in a secure way. The public key present in the Root CA Certificate is generally used to validate the signature on the Root CA certificate. The present invention generally provides for the support of the exact rules for certificate chain validation that generally fully comply with IETF RFC 3280, “Internet X.509 Public Key Infrastructure Certificate and CRL Profile”, and may be referred to as “Certificate Path Validation” rules. The present invention generally provides for the generation of a predetermined number (e.g., in one example, an up to 384-bit, however any appropriate bit-size may be implemented) elliptic curve (EC, i.e., growth) keys and for securely storing the private key for use in digital signatures. The processor of the present invention (e.g., ARM processor 132) may generate EC-DSA digital signatures securely without exposing (i.e., revealing) the respective private key. The ARM processor 132 may verify EC-DSA digital signatures on signed messages and certificates received for authentication. The present invention generally provides for strong (i.e., highly random, non-deterministic, etc.) random number generation (e.g., via the generator 150). In one example, the generator 150 may produce true-random seeds (e.g., seeds generated per RFC 1750 and FIPS 140-2). In another example, the present invention may implement a per-device secret (e.g., a vendor selected code or random number generator) installed at manufacture time and used in the random number generation process. The present invention generally provides for support of simultaneous multiple media transport streams decryption and encryption processing (i.e., multi-stream security). The transport encryption/decryption engines (e.g., the engines 140) generally support at least two or more simultaneous transport stream decryption and encryption processes, and each respective algorithm (e.g., DES, AES, CSA, etc.) depending on overall gate count of the system 100. The present invention may easily implement parallel devices (e.g., parallel coupled stream engines 140) and thus increase multiple transport stream encryption and decryption. Parallel devices (e.g., the logic 134, the RAM 136, the ROM 138, the generator 150, the multiplier 152, the algorithm 154, the hash 156, etc.) may also be used to implement multiple key management schemes for conditional access and for digital rights management. The system 100 may be utilized in the headend of the media stream distribution system for transport stream encryption in highly parallel configurations. The present invention generally provides for the headend implementation in a more cost effective manner than conventional approaches. In one example, the present invention generally provides for support of at least 2 streams of high definition (HD) transport decryption and encryption at a rate of approximately 19.4 megabits per second. However, the present invention may be configured to support any appropriate number of streams of transport decryption and encryption at any appropriate rate. The present invention generally provides for support session based transport decryption and encryption in the development of video on demand (VOD) security. Similarly, the present invention generally provides for support of real-time session based VOD key management. The present invention generally provides support for all related (or corresponding) manufacturing and operational considerations. The present invention may provide support for passage mode partial encryption and decryption in all of the transport encryption engines for all algorithms implemented via the apparatus 100. Referring to FIG. 2, a diagram illustrating a media stream processing and distribution system 200 implemented in connection with the present invention is shown. The distribution system 200 generally comprises a headend 202, a network 204, at least one set top box (STB) 206 (generally a plurality of STBs 206a-206n), and at least one respective receiving device (i.e., receiver, transceiver, etc.) 208 (generally a plurality of devices 208a-208n). The distribution system 200 is generally implemented as a media service provider/subscriber system wherein the provider (or vendor) generally operates the headend 202 and the network 204, and also provides a subscriber (i.e., client, customer, service purchaser, user, etc.) with the STB 206. The STB 206 is generally located at the subscriber location (not shown, e.g., home, tavern, hotel room, business, etc.) and the receiving device 208 is generally provided by the client. The device 208 is generally implemented as a television, high definition television (HDTV), monitor, host viewing device, MP3 player, audio receiver, radio, personal computer, media player, digital video recorder, game playing device, etc. The device 208 may be implemented as a transceiver having interactive capability in connection with the STB 206, the headend 202, or both the STB 206 and the headend 202. The headend 202 is generally electrically coupled to the network 204, the network 204 is generally electrically coupled to the STB 206, and each STB 206 is generally electrically coupled to the respective device 208. The electrical coupling may be implemented as any appropriate hard-wired (e.g., twisted pair, untwisted conductors, coaxial cable, fiber optic cable, hybrid fiber cable, etc.) or wireless (e.g., radio frequency, microwave, infrared, etc.) coupling and protocol (e.g., HomePlug, HomePNA, IEEE 802.11(a-b), Bluetooth, HomeRF, etc.) to meet the design criteria of a particular application. While the distribution system 200 is illustrated showing one STB 206 coupled to a respective one device 208, each STB 206 may be implemented having the capability of coupling more than one device 208 (not shown). The headend 202 generally comprises a plurality of devices 210 (e.g., devices 210a-210n) that are implemented as data servers, computers, processors, security encryption and decryption apparatuses or systems, and the like configured to provide video and audio data (e.g., movies, music, television programming, and the like), processing equipment (e.g., provider operated subscriber account processing servers), television service transceivers (e.g., transceivers for standard broadcast televison and radio, digital televison, HDTV, audio, MP3, text messaging, gaming, etc.), and the like. In one example, the headend 202 may generate and present (i.e., transmit, provide, pass, broadcast, send, etc.) the stream IN. At least one of the devices 210 (e.g., device 210x), may be implemented as the security system 100 as described above in connection with FIG. 1. The device 210 that is implemented as a security system 100 may receive clear or encrypted video and audio data and present clear or encrypted (and compressed or uncompressed) video and audio data. The network 204 is generally implemented as a media stream distribution network (e.g., cable, satellite, and the like) that is configured to selectively distribute (i.e., transmit and receive) media service provider streams (e.g., standard broadcast televison and radio, digital televison, HDTV, audio, MP3, text messaging, games, etc.) for example, as the stream IN to the STBs 206 and to the receivers 208, for example as the stream OUT. The stream IN is generally distributed based upon (or in response to) subscriber information. For example, the level of service the client has purchased (e.g., basic service, premium movie channels, etc.), the type of service the client has requested (e.g., standard TV, HDTV, interactive messaging, etc.), and the like may determine the media streams that are sent to (and received from) a particular subscriber. The STB 206 is generally implemented as an STB having multiple stream capability (e.g., standard broadcast televison and radio, digital televison, audio, MP3, high definition digital television (HDTV), text messaging, etc.). The STB 106 generally comprises at least one respective security processor 212. The security processor 212 may be implemented as the security processor (or system) 100. The processor 212 may receive encrypted (and compressed) video and audio data (e.g., the stream IN) and present clear video and audio data (e.g., the stream OUT) to the receiver 208. In one example (not shown), the security processor (or system) 100 may be implemented in connection with the device 208. The device (e.g., transceiver) 208 may send an encrypted or a clear media stream to the headend 202 via the STB 206 and the network 204. As such, the system 100 of the present invention may be implemented in any of the headend 202, the STB 206, and the receiving device 208, alone or in combination. Referring to FIG. 3, a diagram illustrating a media stream processing and distribution system 200′ implemented in connection with the present invention is shown. The distribution system 200′ generally comprises the headend 202, the network 204, and at least one of the receiving device (i.e., receiver, transceiver, etc.) 208 (generally a plurality of the devices 208a-208n). The receiving device 208 is generally coupled directly to the network 204 and receives the signal IN. In yet another example (not shown), the system 200′ may be implemented having at least one STB 206 coupled to the network 204 and with at least one receiver 208 coupled thereto, as well as having at least one device 208 that is directly coupled to the network 204. The improved system and method of the present invention may ease the difficulty in introducing new conditional access systems into an MSO network due the legacy hardware and software already deployed. In contrast, the time and expense of performing a transition to a new conditional access system can be extremely prohibitive particularly if the transition must occur in a short time period when conventional approaches are used. The present invention may provide an MSO the ability to support legacy systems and make a transition to a new CAS or alternative proprietary CAS as desired, thereby facilitating a more smooth and cost effective transition that may be able to be amortized over a longer time period. The present invention may provide support for the parameters of retail distribution. As is readily apparent from the foregoing description, then, the present invention generally provides an improved system and an improved method for a configurable, renewable, and re-configurable security system and method used to encrypt/decrypt media streams in a digital media stream distribution system (e.g., in a headend, in a STB, in host digital television devices, and the like). The present invention may provide support for encryption and decryption of legacy CASs, the DVB-CSA CAS proprietary systems, Digital Rights Management for media (e.g., video, audio, video plus audio, etc.), Video On Demand, and newly developed conditional access systems. The present invention may provide support for authentication of devices and generally provides novel concepts in renewability and hardware re-configuration for media conditional access systems. The present invention may provide for use of a highly secure role-based authentication to securely configure and renew the overall security system and key management techniques in a digital media stream processing environment. While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a system and a method for security processing media streams. 2. Background Art Conventional implementations of media (e.g., video, audio, video plus audio, and the like) program stream delivery systems(e.g., cable, satellite, etc.) include a headend where the media programming originates (i.e., is encoded and compressed, groomed, statmuxed, and otherwise appropriately processed), a network (e.g., cable or satellite) for delivery of the media programming to the client (i.e., customer, user, buyer, etc.) location, at least one set top box (STB) at the client location for conversion (e.g., decryption and decompression) of the media programming stream, and at least one respective viewing device such as a television (TV) or monitor that is connected to the STB. Conventional headends and STBs employ particular matching encryption/decryption and compression/decompression technologies. However, there is little standardization of particular matching encryption/decryption across media program stream delivery system vendors. The encryption/decryption and compression/decompression technologies in the particular conventional system are fixed and often proprietary to the vendor. Furthermore, conventional media service processing and delivery systems typically implement security processes in connection with individual implementations of point of deployment, CableCard, Smartcard, etc. systems. Transitions to upgrades in encryption/decryption and compression/decompression technologies are, therefore, expensive and difficult for the media program stream delivery system vendors to implement. As such, customers can be left with substandard service due to the lack of standardization and the reduced competition that the lack of standardization has on innovation in media service delivery. The lack of standardization also restricts the ability of media service providers to compete. For example, customers may have viewing devices that could take advantage of the improved technologies, however, media stream delivery system upgrades may be impossible, impracticable, or not economically feasible for vendors using conventional approaches. A significant level of customer dissatisfaction may result. As a result, it would be desirable to have an improved system and method for security processing media streams that addresses the above indicated problems with conventional approaches as well as providing additional improvements. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention generally provides an improved system and method for security processing digital media streams. The improved system and method for security processing media streams of the present invention may be compatible with previously used (i.e., legacy) systems and methods using all levels of media stream processing and delivery service (i.e., basic to high-end) as well as adaptable to future implementations, and that is flexible, renewable, re-configurable, and supports simultaneous multiple security systems and processes. According to the present invention, a system for multi-stream security processing and distributing digital media streams is provided. The system comprises a headend, a network, and at least one receiver. The headend may be configured to generate encrypted digital media streams. The network may be coupled to the headend and configured to receive the encrypted digital media streams. The at least one receiver may be coupled to the network and configured to receive the encrypted digital media streams and present a decrypted version of the encrypted digital media streams. At least one of the headend and the at least one receiver comprises a security processor that may be configured to provide at least one of simultaneous multiple encryption and simultaneous multiple decryption processing of the digital media streams. For example, in one implementation the headend may utilize the security processor of the present invention to encrypt the digital media streams and the one or more receivers may use a conventional approach to decrypt the digital media streams. In another example, the headend may utilize a conventional approach to encrypt the digital media streams and one or more of the receivers may use the security processor of the present invention to decrypt the digital media streams. In yet another example, the headend may utilize the security processor of the present invention to encrypt the digital media streams and one or more of the receivers may use the security processor of the present invention to decrypt the digital media streams. In all of the implementations, the headend generally encodes, compresses, grooms, statmuxs, and otherwise appropriately processes the digital media streams. The receivers may, in one example, be implemented as set top boxes (STBs). In other examples, the receiver (receiving device) may be implemented as a television, high definition television (HDTV), monitor, host viewing device, MP3 player, audio receiver, radio, personal computer, media player, digital video recorder, game playing device, etc. Also according to the present invention, a method of multi-stream security processing and distributing digital media streams is provided. The method comprises generating encrypted digital media streams at a headend. The method further comprises coupling a network to the headend and receiving the encrypted digital media streams at the network. The method yet further comprises coupling at least one receiver to the network and receiving the encrypted digital media streams at the receiver, and presenting a decrypted version of the encrypted digital media streams using the receiver. At least one of the headend and the at least one receiver comprises a security processor that may be configured to provide at least one of simultaneous multiple encryption and simultaneous multiple decryption processing of the digital media streams. Further, according to the present invention, for use in a system for multi-stream security processing and distributing digital media streams, a security processor configured to provide at least one of simultaneous multiple media transport stream decryption and encryption processing is provided. The security processor comprises a controller and a plurality of digital stream engines. The digital stream engines may be selectively parallel coupled by the controller for simultaneous operation in response to a predetermined security configuration. The above features, and other features and advantages of the present invention are readily apparent from the following detailed descriptions thereof when taken in connection with the accompanying drawings. | 20040129 | 20091117 | 20050804 | 75630.0 | 3 | GYORFI, THOMAS A | SYSTEM AND METHOD FOR SECURITY PROCESSING MEDIA STREAMS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,768,391 | ACCEPTED | Condiment dispenser | A device for dispensing having a vessel having a cover at a first end and having a second end is provided. A longitudinal separator is positioned in the vessel that has an annular channel extending therethrough. The device provides for a first dial rotatably connected to the second end and having a central recess, a central hole and an first eccentric hole, a second dial received in the recess and having a second central hole in registration with the first hole, and a second eccentric hole capable of being in registration with the first eccentric hole. The device has a rotatable shaft extending through the cover, the channel, the first central hole and fixable in the second central hole for selectively providing registration between the first eccentric hole and the second eccentric hole. The dispenser is usable in a variety of appliances such as ice cream makers or coffee-related device. | 1. A device comprising: a vessel having a cover at a first end and having a second end; a longitudinal separator, in said vessel, having an annular channel extending therethrough and a number of longitudinal radially extending vanes dividing said vessel into a number of compartments; a pair of dials, each dial of said pair of dials having an eccentric hole therethrough; and a rotatable shaft extending through said cover, said annular channel and said pair of dials for selectively providing registration between said eccentric holes. 2. The device according to claim 1, wherein said pair of dials comprises: a first dial rotatably connectable to said second end and further comprising a first central recess, a first central hole therethrough; and a second dial slidingly received in said first central recess and further comprising a second central hole in registration with said first central hole. 3. The device according to claim 1, further comprising a motor assembly housing removably connected to said cover. 4. The device according to claim 3, wherein said housing has a motor operatively connected to said shaft. 5. The device according to claim 4, further comprising an adjustment knob for controlling said motor. 6. The device according to claim 1, wherein said vessel is cylindrical. 7. The device according to claim 1, wherein said vessel is made from a transparent material. 8. The device according to claim 1, wherein said number of vanes is at least four. 9. The device according to claim 4, wherein said shaft is operatively connected to said motor for selectively controlling the rate of rotation of said second dial. 10. A ice cream machine having a condiment dispenser comprising: a first vessel having a first end and a second end; a second vessel having a third end and a fourth end; a funnel enclosing said second end and said fourth end; a longitudinal separator in said first vessel, said separator having an first annular channel extending therethrough, and a number of longitudinal radially extending vanes dividing said vessel into a number of compartments; a first dial rotatably connectable to said second end and having a first central recess, a first central hole therethrough and a first eccentric hole therethrough; a second dial slidingly received in said first recess and having a second central hole in registration with said first central hole, and a second eccentric hole capable of being in registration with said first eccentric hole; and a rotatable shaft extending through said first vessel, said annular channel, said first central hole and rigidly fixable to said second central hole for selectively providing registration between said first eccentric hole and said second eccentric hole. 11. The ice cream machine according to claim 10, further comprising: a cover at said third end; a second dial rotatably connectable to said fourth end and having a second central recess, a third central hole and an third eccentric hole therethrough; a fourth dial slidingly received in said second central recess and having a fourth central hole in registration with said third central hole, and a fourth eccentric hole capable of being in registration with said third eccentric hole; and a second rotatable shaft extending through said second cover and said third central hole and rigidly fixable to said fourth central hole for selectively providing registration between said third eccentric hole and said fourth eccentric hole. 12. The ice cream machine according to claim 10, further comprising a motor assembly housing connected to said second vessel. 13. The ice cream machine a condiment dispenser according to claim 12, further comprising a motor assembly in said housing that is operatively connected to said second shaft and said first shaft to provide selective rotations to said second shaft and said first shaft. 14. The ice cream machine according to claim 10, wherein said first vessel and said second vessel are cylindrical and have a respective first axis and a second axis. 15. The ice cream machine according to claim 14, wherein said first axis and said second axis are parallel and non-coincident. 16. The ice cream machine according to claim 10, wherein said first vessel and said second vessel are made from a transparent material. 17. The ice cream machine according to claim 11, wherein said second rotatable shaft has arcuate arms extending therefrom. 18. A device for dispensing comprising: a vessel having a first end and a second end; a longitudinal separator in said first vessel, said separator having an first annular channel extending therethrough; and a number of longitudinal radially extending vanes that divide the vessel into the number of compartments; a funnel capable of being in registration with one of said compartments; a first dial fixedly connectable to said first end for selectively orienting said compartments; a second dial slidingly received on said second end, said second dial having a central hole and an eccentric hole capable of being in registration with one of said compartments; and a rotatable shaft extending through said central hole, said annular channel for selectively providing registration between said eccentric hole and said compartment. 19. The device according to claim 18, further comprising a motor operatively connected to said shaft for providing rotation thereto. 20. The device according to claim 19, further comprising a grinding chamber attached to said vessel and beneath said eccentric hole. 21. A dispenser comprising: a vessel having a first end and having a second end; a longitudinal separator, in said vessel, having an annular channel extending therethrough and a number of longitudinal radially extending vanes dividing said vessel into the number of compartments; a first dial rotatably connectable to said second end and having a central recess, a central hole therethrough and an eccentric hole therethrough; a second dial slidingly received in said recess and having a second central hole extending therethrough and in registration with said first central hole, and a second eccentric hole extending therethrough and capable of being in registration with said first eccentric hole; and a rotatable shaft extending through said vessel, said annular channel and said pair of dials for selectively providing registration between said eccentric holes. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for selecting and dispensing condiments. More particularly, the present invention relates to an apparatus for allowing a user to select a condiment and evenly dispense the condiment. 2. Description of Related Art Condiment dispensers are available in a variety of forms. They can be as simple as caddies, that hold a condiment for a food operator, or more advanced as the pumps often seen in fast food restaurants. Condiment dispensers are as ubiquitous as salt and pepper shakers. While these condiment dispensers are often used, they do not provide the even dispensing of a condiment that is often desired. Such condiment dispensers like those for consumer use must have minimal parts, be very safe and easy to use. Therefore, there exists a need for a condiment dispenser that automatically and evenly dispenses the condiment itself or dispenses the condiment into a bin. SUMMARY OF THE INVENTION It is an object of the present invention to provide a condiment dispenser. It is another object of the present invention to provide a condiment dispenser that provides for selection of a particular condiment. It is still another object of the present invention to provide a condiment dispenser that provides even dispensing of a selected condiment. It is yet another object of the present invention to provide a condiment dispenser that provides automatic dispensing of a selected condiment. It is a further object of the present invention to provide a condiment dispenser that evenly dispenses the condiment itself or evenly dispenses the condiment into a bin to be mixed with another condiment, food item or the like. The above and other objects, advantages, and benefits of the present invention will be understood by reference to following detailed description and appended sheets of drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the condiment dispenser of the present invention; FIG. 2 is an exploded view of the condiment vessel and dials of the dispenser of FIG. 1; FIG. 3 is an exploded view of the dials of the dispenser of FIG. 1; FIG. 4 is front plan view of an exemplary embodiment of the present invention incorporated into an ice cream maker; FIG. 5 is a front plan view of a exemplary second embodiment of present the invention incorporated into a coffee machine; and FIG. 6 is a front plan view of as alternative embodiment of the invention of FIG. 5. DETAILED DESCRIPTION OF THE INVENTION Referring to the figures, and more particularly to FIGS. 1 and 2, a condiment dispenser according to the present invention is generally designated by reference numeral 10. Dispenser 10 has a cover 20 and a vessel 30 removably connectable the cover 20. The vessel 30 has a selection dial 50. A dispensing dial 80 is preferably positioned in selection dial 50. Dispenser 10 also has a motor assembly housing 70 housing a motor therein, to which the vessel cover 30 is removably connected. The vessel cover 20 is connected to a motor housing assembly 70. Preferably, this connection is a snap-fit connection, or any such connection that will alert the user that vessel cover 20 is securely fitted to motor housing assembly 70. The vessel cover 20 has a safety hole 22 into which a post 72 from motor housing assembly 70 extends to provide an additional positive connection to motor housing assembly 70. The condiment vessel 30 is preferably cylindrically shaped. Also, condiment vessel 30 is preferably rotationally connected to vessel cover 20. In this embodiment, condiment vessel 30 can have threads on its outer surface to mate with corresponding threads on the inner surface of vessel cover 20. Alternatively, condiment vessel 30 can have a partial lip that protrudes and engages corresponding slots in vessel cover 20. Preferably, vessel cover 20 and vessel 30 are both transparent so that the contents in the condiment vessel 30 can be easily viewed by a user. Motor housing assembly 70 is preferably made of a plastic material, for example acrylonitrile-butadiene styrene (ABS), or any such plastic material commonly used for household appliances. Alternatively, motor housing assembly 70 can be made from stainless steel, brushed aluminum, or at least have an outer surface made of stainless steel or brushed aluminum. Preferably, vessel cover 20 and condiment vessel 30 are preferably made of glass or a strong plastic, for example polycarbonate, although other similar plastics commonly for household appliances could also be used. Referring to FIGS. 2 and 3, condiment vessel 30 has a separator 32 that extends the entire length of the condiment vessel 30. The separator 32 has a central portion 36 with an annular channel hollow 38 that is sized to receive a shaft 60 in sliding rotation during operation of the dispenser 10. Central portion 36 preferably has at least four vanes or fins 34 extending radially therefrom that divide the condiment vessel 30 into a number of compartments 40. The separator 32 remains stationary inside of condiment vessel 30 during operation of condiment dispenser 10. The selection dial 50 preferably abuts or preferably slidingly received over an outer end 42 of condiment vessel 30. The selection dial 50 receives shaft 60 that freely rotates in a central hole 52. Selection dial 50 has a selection hole 54 that is sized to accept the contents 100 of condiment vessel 30. A user can rotate selection dial 50 over outer end 42 of condiment vessel 30 to change the location of selection hole 54 to correspond to a particular compartment 40 in condiment vessel 30. Selection dial 50 has a recessed portion 56 that slidingly accepts a dispenser dial 80. Dial 80 has a central hole 82 that has internal threads 86 and a dispenser hole 84 that can lie in registration with selection hole 54 of selection dial 50. When selection dial hole 54 is beneath a particular compartment 40, and in registration with dispenser hole 84, the contents will be released from dispenser 10. Condiment vessel 30 also has or is adapted to receive a shaft 60. The shaft 60 has a proximal end 68 and a distal end 62. The proximal end 68 is operatively connected to motor shaft (not shown) of the motor housing in motor housing 70. When different components of the condiment dispenser 10 are disassembled, shaft 60 can be disconnected from the motor assembly. The distal end 62 of shaft 60 has a knob 64 located that lies beneath dispenser dial 80. On shaft 60, proximate knob 64, are external threads 66 that mate with the internal threads of hole 82 to allow shaft 60 and dispenser dial 80 to move as a single unit when dispenser 10 is energized. The present invention also contemplates different pairings of selection dial 50 and dispenser dial 80 that have holes of varied but corresponding size depending on the condiment that is to be dispensed. For example, dispensing cookie pieces would require larger holes 54 and 84 of respective dials than sprinkles or sauces would require. Furthermore, the smaller dispenser holes may optionally have a spout attachment. The motor assembly housing 70 houses the motor (not shown), a gear reduction assembly and a motor shaft (not shown). The motor is connected to proximal end 68 of shaft 60 to impart, preferably a constant rotational movement to dial 80, which freely rotates in selection dial recess 56. The motor provides a constant rotation of dial 80, as it passes the stationary selection dial hole 54 located beneath a particular compartment 40. By rotating at a constant rate, dial 80 will cause a dispensing or dispenser hole 84 to pass fixed selection dial hole 54 at a constant rate. The constant rate provides even dispensing of the condiment into a bin containing another food, such as ice cream or bread, that may continue to be mixed or that may be concurrently dispensed. Also, the even dispensing of the condiment allows a constant volume of condiment to be dispensed during each rotation of dial 80. The motor is preferably an electrically powered motor that is supplied with AC power from a socket or battery powered in a convention manner. The speed of the motor is adjustable using setting knob 74 on the outer surface of housing 70. The speed can be adjusted depending on the condiment to be dispensed, the frequency or rate of dispensing, and the amount of condiment to be dispensed during each dial rotation. In operation, condiment dispenser 10 can be used to dispense condiments into a funnel to be mixed with another food such as soft-serve ice cream or bread. Before filling any of the compartments 40, the user may ensure that selection hole 54 and dispenser hole 84 were not in registration to prevent an inadvertent spilling of the condiments. The user can remove vessel cover 20 and condiment vessel 30 including shaft 60, dials 50, and 80, from the motor assembly housing 70. The user may fill all except one of the compartments 40 with condiments 12. The condiments 12 can be large condiments or toppings such as ground nuts, cookie pieces, raisins or ice cream and the condiments can be very small such as cake sprinkles or even sauces. The user can rotate selection dial hole 54 to be beneath compartment 40 containing the particular condiment 12 to be used. Selection dial 50 remains stationary throughout the operation of dispenser 10. Referring to FIG. 4, in a further embodiment, condiment dispenser 10 can be incorporated in an ice cream maker 90. Ice cream maker 90 has a motor assembly 100, an ice cream mixing bowl 110 and a funnel 120. Mixing bowl 110 receives ingredients for making ice cream. In this embodiment, condiment dispenser 10 operates as discussed above, except that shaft 60 is preferably energized by motor assembly 100. Motor assembly 100 is preferably operatively connected to a shaft in mixing bowl 110, a selector dial 112 and a dispenser dial 114 to dispense ice cream. Selector dial 112 and dispenser dial 114, each have respective eccentric holes that can be brought into registration during dial 114 rotation. The motor assembly 100 has a motor (not shown) that is operatively connected to a gear system that turns both shaft 60 and a churner 116 in mixing bowl 110. The gear system is capable of turning shaft 60 and churner 116 at different rates to provide proper dispensing of the condiments and the ice cream. In the embodiment of FIG. 4, the motor speed can be controlled by an adjustment knob 106 preferably located on motor assembly 100. Depending upon the condiment used and other factors, the rate of rotation of shaft 60 can be varied. For example, if the user wants to move dial 50 to be beneath a different compartment 40, the speed of rotation may also have to be adjusted. Similar to the embodiment of FIG. 1, an even rate of rotation of the dial 80 will allow even dispensing of the condiment into funnel 120. Concurrently, the dispenser dial 114 will also provide even dispensing of ice cream into the funnel 120. Proper mixing in funnel 120 will ensure an even distribution of condiments throughout the ice cream when it flows from a nozzle 122. Referring to FIG. 5, which is another embodiment of the present invention, condiment dispenser 10 can be incorporated in a coffee grinder 150. In this embodiment, a selector dial 160 and a dispenser dial 180 are preferably not adjacent. They are separated by a ground coffee hopper 170. Selector dial 160 is operatively connected to ground coffee hopper 170 and a central shaft thereof (not shown) is operatively connected to dispenser dial 180. Hopper 170 is divided into a number compartments by a separator. Dispenser dial 180 has an eccentric dispenser dial hole 182 to release contents of a compartment into a brew basket 190. The user can rotate selector dial 160 with hopper 170 to be above a brew basket 190. Dispenser dial hole 182 will not be located beneath the basket to prevent in advertent spills. When the motor (not shown) of this embodiment is energized, the selected compartment and dispenser dial hole 182 will be brought in registration to dispense the ground coffee into a brew basket 190. Referring to FIG. 6, in a still further embodiment, the condiment dispenser 10 can be incorporated into a coffee grinder. This embodiment operates, in a similar fashion to the embodiment of FIG. 5. However, in this embodiment, the hopper contains beans and a grinding chamber 210 is located beneath the dispenser dial 180 to grind the selected bean that is to drop in to brew basket 190. While the present invention has been described with reference to one or more exemplary embodiments, it will be understood that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the present invention not be limited to the particular embodiment(s) disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to an apparatus for selecting and dispensing condiments. More particularly, the present invention relates to an apparatus for allowing a user to select a condiment and evenly dispense the condiment. 2. Description of Related Art Condiment dispensers are available in a variety of forms. They can be as simple as caddies, that hold a condiment for a food operator, or more advanced as the pumps often seen in fast food restaurants. Condiment dispensers are as ubiquitous as salt and pepper shakers. While these condiment dispensers are often used, they do not provide the even dispensing of a condiment that is often desired. Such condiment dispensers like those for consumer use must have minimal parts, be very safe and easy to use. Therefore, there exists a need for a condiment dispenser that automatically and evenly dispenses the condiment itself or dispenses the condiment into a bin. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide a condiment dispenser. It is another object of the present invention to provide a condiment dispenser that provides for selection of a particular condiment. It is still another object of the present invention to provide a condiment dispenser that provides even dispensing of a selected condiment. It is yet another object of the present invention to provide a condiment dispenser that provides automatic dispensing of a selected condiment. It is a further object of the present invention to provide a condiment dispenser that evenly dispenses the condiment itself or evenly dispenses the condiment into a bin to be mixed with another condiment, food item or the like. The above and other objects, advantages, and benefits of the present invention will be understood by reference to following detailed description and appended sheets of drawings. | 20040130 | 20070612 | 20050804 | 99781.0 | 0 | NICOLAS, FREDERICK C | CONDIMENT DISPENSER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,768,409 | ACCEPTED | Porting a directory number for a duration of time | An apparatus in one example comprises a portability component that automatically updates one or more provisioning components to port a directory number for a duration of time. | 1. An apparatus, comprising: a portability component that automatically updates one or more provisioning components to port a directory number for a duration of time. 2. The apparatus of claim 1, wherein upon initiation of a request to port the directory number, the portability component receives one or more identifiers associated with the one or more provisioning components; wherein the portability component employs the one or more identifiers to notify the one or more provisioning components of the request to port the directory number for the duration of time. 3. The apparatus of claim 2, wherein the request to port the directory number comprises an association between the directory number and a location routing number; wherein upon initiation of the request to port the directory number, the portability component provides the association to a management component; wherein the management component provides the association to one or more local number portability databases associated with the one or more provisioning components; wherein one or more network components associated with the one or more provisioning components and the one or more local number portability databases cooperate to provide and/or terminate service for the directory number for the duration of time based on the association. 4. The apparatus of claim 2, wherein the one or more provisioning components comprise a ported-from provisioning component and a ported-to provisioning component, wherein the one or more identifiers associated with the one or more provisioning components comprise a first identifier associated with the ported-from provisioning component and a second identifier associated with the ported-to provisioning component; wherein the directory number is associated with a telephony device, wherein the portability component communicates with the ported-from provisioning component through employment of the first identifier to terminate service for the telephony device for the duration of time; wherein the portability component communicates with the ported-to provisioning component through employment of the second identifier to provide service for the telephony device for the duration of time. 5. The apparatus of claim 4, wherein the ported-from provisioning component is associated with a first service provider, wherein the ported-to provisioning component is associated with a second service provider; wherein the portability component cooperates with the ported-from provisioning component and the ported-to provisioning component to port the directory number from the first service provider to the second service provider for the duration of time. 6. The apparatus of claim 4, wherein the ported-from provisioning component provides a first set of services to the telephony device, wherein the ported-to provisioning component provides a second set of services to the telephony device; wherein the portability component cooperates with the ported-from provisioning component to terminate access to the first set of services by the telephony device for the duration of time; wherein the portability component cooperates with the ported-to provisioning component to provide access to the second set of services by the telephony device for the duration of time. 7. The apparatus of claim 1, wherein upon expiration of the duration of time, the portability component in combination with the one or more provisioning components port the directory number back to an initial state. 8. The apparatus of claim 7, wherein the one or more provisioning components comprise a ported-from provisioning component and a ported-to provisioning component; wherein the ported-to provisioning component initiates a request to the portability component to port the directory number for the duration of time; wherein upon receipt of the request to port the directory number, the portability component notifies the ported-from provisioning component of the request to port the directory number. 9. The apparatus of claim 8, further comprising: a subscriber database that comprises a subscriber entry for the directory number; wherein the portability component and the ported-from provisioning component cooperate to change the subscriber entry in the subscriber database from the initial state to a ported state; wherein the subscriber database and a switch component cooperate to terminate service at a network for a telephony device associated with the directory number. 10. The apparatus of claim 9, wherein upon expiration of the duration of time, the portability component and the ported-from provisioning component cooperate to change the subscriber entry in the subscriber database from the ported state to the initial state; wherein the subscriber database and the switch component cooperate to restart the service at the network for the telephony device associated with the directory number. 11. The apparatus of claim 10, wherein the subscriber database and the switch component cooperate to notify one or more callers to the directory number of the expiration of the duration of time to port the directory number. 12. The apparatus of claim 9, wherein the subscriber database and the switch component cooperate to notify a user of the telephony device associated with the directory number of a period of time remaining until the expiration of the duration of time to port the directory number. 13. The apparatus of claim 1, wherein one of the one or more provisioning components initiates a request to port the directory number for the duration of time, wherein the request comprises a value for the duration of time, the apparatus further comprising: a timer component that determines an expiration of the duration of time to port the directory number based on the value for the duration of time; wherein upon the expiration of the duration of time to port the directory number, the portability component and the timer component cooperate to port the directory number back to an initial state. 14. The apparatus of claim 13, wherein upon the expiration of the duration of time to port the directory number, the timer component sends to the portability component a notification of the expiration of the duration of time and the directory number; wherein upon receipt of the notification from the timer component, the portability component employs the directory number to notify the one or more provisioning components of the expiration of the duration of time associated with the directory number; wherein the one or more provisioning components port the directory number back to the initial state. 15. The apparatus of claim 13, wherein the value for the duration of time comprises a first value for the duration of time; wherein upon receipt of a request to reset the value for the duration of time, the portability component provides a second value for the duration of time to the timer component; wherein the timer component employs the second value for the duration of time to determine the expiration of the duration of time. 16. The apparatus of claim 1, wherein the portability component comprises one or more interfaces with the one or more provisioning components, wherein the portability component employs the one or more interfaces to receive one or more identifiers associated with the one or more provisioning components and a value for the duration of time from the one or more provisioning components. 17. The apparatus of claim 1, wherein the portability component stores an association between the directory number and one or more location routing numbers, wherein a telephony device associated with the directory number receives service associated with the location routing number; wherein upon an expiration of the duration of time, the portability component removes the association between the directory number and the location routing number, wherein the telephony device receives service associated with the directory number and/or one of the one or more location routing numbers. 18. A method, comprising the step of: automatically updating one or more provisioning components to port a directory number for a duration of time. 19. The method of claim 18, wherein the step of automatically updating the one or more provisioning components to port the directory number for the duration of time comprises the steps of: receiving a request to port the directory number, wherein the request comprises one or more identifiers associated with the one or more provisioning components, a value for the duration of time, and an association between the directory number and a location routing number; providing the association to one or more of the one or more provisioning components through employment of one or more of the one or more identifiers upon receipt of the request; setting a ported-out flag associated with the directory number; determining an expiration of the duration of time through employment of the value for the duration of time; notifying one or more of the one or more provisioning components through employment of one or more of the one or more identifiers upon the expiration of the duration of time; and clearing the ported-out flag associated with the directory number upon the expiration of the duration of time. 20. The method of claim 19, wherein a first provisioning component of the one or more provisioning components is associated with a first service provider, wherein a second provisioning component of the one or more provisioning components is associated with a second service provider, wherein the step of clearing the ported-out flag associated with the directory number upon the expiration of the duration of time, the method further comprising the steps of: porting the directory number from a network of the first service provider to a network of the second service provider; terminating service for a telephony device associated with the directory number on the network of the first service provider; providing service for the telephony device on the network of the second service provider; receiving a notification of the expiration of the duration of time; porting the directory number from the network of the first service provider to the network of the second service provider; terminating service for the telephony device associated with the directory number with the second service provider; and providing a message indicating the expiration of the duration of time to a user of the telephony device associated with the directory number. 21. An article, comprising: one or more computer-readable signal-bearing media; and means in the one or more media for automatically updating one or more provisioning components to port a directory number for a duration of time. | TECHNICAL FIELD The invention relates generally to telecommunications and more particularly to porting directory numbers associated with telephony devices. BACKGROUND Number portability (“NP”) is a telecommunications network feature that enables a user of a telephony device to retain their directory number when changing service providers, service types, and/or locations. For example, the user may desire to temporarily try out a new telephony device and/or a new set of services while retaining their directory number. So, to port the directory from a first service provider to a second service provider, databases associated with the first and second service providers in one example are manually updated. Before porting the directory number, the user receives service from the first service provider. Upon porting the directory number to the second service provider, the user receives service from the second service provider. To port the directory number between the service providers, one or more employees of the second service provider manually enter an association between the directory number and a location routing number into a database associated with the second service provider. The employees of the second service provider may also request that the first service provider manually updates a database associated with the first service provider. After porting the number from the first service provider to the second service provider, the user may desire to restart service with the first service provider. So, the directory number must be ported back from the second service provider to the first service provider and the databases associated with the first and second service providers must be manually updated a second time. Manual updating of the databases may take several days. As one shortcoming, the user of the telephony device associated with the directory number may not receive service from either of the service providers until both the databases are updated. It is desirable for the user of the telephony device associated with the directory number to receive continuous service. Thus, a need exists to reduce an amount of time required to port a directory number between service providers. A further need exists to reduce a duration of a potential service interruption experienced by a user while porting the directory number. SUMMARY The invention in one implementation encompasses an apparatus. The apparatus comprises a portability component that automatically updates one or more provisioning components to port a directory number for a duration of time. Another embodiment of the invention encompasses a method. One or more provisioning components are automatically updated to port a directory number for a duration of time. Yet another embodiment of the invention encompasses an article. The article comprises one or more computer-readable signal-bearing media. The article comprises means in the one or more media for automatically updating one or more provisioning components to port a directory number for a duration of time. DESCRIPTION OF THE DRAWINGS Features of exemplary implementations of the invention will become apparent from the description, the claims, and the accompanying drawings in which: FIG. 1 is a representation of one exemplary implementation of an apparatus that comprises one or more portability components, one or more management components, and one or more networks. FIG. 2 is a representation of one or more components of the networks of the apparatus of FIG. 1. The networks comprise one or more local portability databases, one or more timer components, one or more subscriber databases, one or more switch components, and one or more provisioning components. FIG. 3 is a representation of an exemplary process flow of a request to port a directory number for a duration of time received by the portability component from a provisioning component of the apparatus of FIG. 2. FIG. 4 is a representation of an exemplary process flow of a request to make permanent a ported directory number received by the portability component from a provisioning component of the apparatus of FIG. 2. FIG. 5 is a representation of an exemplary process flow of resetting a value of a duration of time to port a directory number by the portability component of the apparatus of FIG. 1. DETAILED DESCRIPTION Turning to FIGS. 1-2, an apparatus 100 in one example comprises one or more portability components 105, one or more management components 110, and one or more networks 115 and 120. The networks 115 and 120 in one example comprise one or more telephony networks that are owned and/or operated by one or more service providers. The management component 110 in one example comprises a Number Portability Administration Center Service Management System (“NPAC”), as will be understood by those skilled in the art. The portability component 105 and the management component 110 communicate through employment of one or more protocols, for example, a Session Initiation Protocol (“SIP”) or a Simple Network Management Protocol (“SNMP”). The portability component 105 and the networks 115 and 120 communicate through employment of one or more protocols, for example, SIP, an Internet Standard-41 (“IS-41”), and an Advanced Intelligence Network (“AIN”). The portability component 105 in one example provides information to port a directory number to the management component 110. The management component 110 in one example updates one or more local portability databases 205 and 210 associated with the networks 115 and 120. The portability component 105 provides information to one or more network components associated with the networks 115 and 120 to port the directory number. The networks 115 and 120 employ the information to provide and/or to terminate service for one or more telephony devices, for example, one or more wired telephones, wireless telephones, and/or personal computers, associated with the directory number. The networks 115 and/or 120 in one example comprise the one or more local portability databases 205 and 210, one or more timer components 215 and 220, one or more subscriber databases 225 and 230, one or more switch components 235 and 240, and one or more provisioning components 245 and 250. In one example, the subscriber databases 225 and/or 230 comprise one or more home location registers, as will be understood by those skilled in the art. The subscriber databases 225 and/or 230 comprise one or more subscriber databases located within the switch components 235 and/or 240. The switch components 235 and/or 240 in one example comprise one or more telephony switches. The subscriber databases 225 and/or 230 and the switch components 235 and/or 240 in one example cooperate to provide and/or to terminate service to the telephony devices. The provisioning components 245 and 250 in one example comprise one or more customer care centers associated with the networks 115 and 120, respectively. In one example, the provisioning components 245 and/or 250 initiate one or more requests to port a directory number for a duration of time to the portability component 105. In another example, the provisioning components 245 and/or 250 receive from the portability component 105 one or more updates for one or more directory numbers ported to the network 115. The updates in one example comprise the directory number or a location routing number (“LRN”) and a value for the duration of time to port the directory number. Upon receipt of an update for a directory number, the provisioning components 245 and/or 250 notify the subscriber databases 225 and/or 230, respectively, of the directory number to port for the duration of time. The local portability databases 205 and/or 210 in one example comprise one or more entries for one or more directory numbers that have been ported to/from the networks 115 and/or 120. The entries in one example comprises a directory number and a location routing number for a telephony device that is ported from the network 115 to the network 120, as will be understood by those skilled in the art. The timer components 215 and/or 220 in one example comprise one or more timers associated with one or more directory numbers associated with the telephony devices. In one example, the timer components 215 and/or 220 are resident in the subscriber databases 225 and/or 230, respectively. In another example, the timer components 215 and/or 220 are resident in the provisioning components 245 and/or 250. In yet another example, the timer components 215 and/or 220 are resident in the local number portability databases 205 and/or 210. The portability component 105 in one example receives one or more requests to port a directory number for a duration of time from the provisioning components 245 and/or 250. A request to port a directory number in one example comprises an association between a ported-from number (directory number or location routing number) and a ported-to number (location routing number), one or more identifiers associated with one or more network components, and a value for the duration of time. In one example, a request to port a directory number comprises an association between the directory number and a location routing number. In another example, a request to port a directory number comprises an association between a first (old) location routing number and a second (new) location routing number. For example, if a directory number is ported more than one time, the request comprises an association between a first location routing number and a second location routing number. The identifiers associated with the one or more network components in one example comprise the provisioning components 245 and/or 250, and/or the subscriber databases 225 and/or 230. In one example, a first identifier is associated with a ported-from provisioning component, for example, the provisioning component 245, and a second identifier is associated with a ported-to provisioning component, for example, the provisioning component 250. The portability component 105 employs the identifiers to automatically update the one or more network components (e.g., the provisioning components 245 and/or 250 and/or the subscriber databases 225 and/or 230) upon receipt of the request. The value for the duration of time in one example indicates one or more of: a period of time, a date in the future, or a permanent status. The portability component 105 in one example stores the association between the ported-from number (the directory number or the (old) location routing number) and the ported-to number (location routing number), the one or more identifiers, and the value for the duration of time. The portability component 105 employs the association to update the network components associated with the identifiers. In one example, upon receipt of a request to update a duration of time for a directory number, the portability component 105 employs the association to reset a value of the duration of time within the timer components 215 and 220. In another example, upon receipt of a request to make permanent the port of the directory number, the portability component 105 updates the network components associated with the one or more identifiers of the association. Upon receipt of a request from the provisioning component 250, the portability component 105 employs one or more of the one or more identifiers to automatically update the provisioning component 245 of the request to port the directory number for the duration of time. In one example, the portability component 105 provides a value for the duration of time to the provisioning component 245. In another example, the portability component 105 provides an association between a ported-from telephony number (e.g., the directory number) and a ported-to telephony number (e.g., the location routing number) to the provisioning component 245. The provisioning component 250 in one example updates the subscriber database 230 upon receipt of the association. The portability component 105 automatically updates the management component 110 upon receipt of the request from the provisioning component 250. The portability component 105 cooperates with the provisioning components 245 and 250 to port the directory number back to an initial state from a ported state upon an expiration of the duration of time. The initial state in one example comprises a service provider and/or a set of services provided to a telephony device associated with the ported-from number before the request to port the directory number. The ported state in one example comprises a service provider and/or a set of services provided to the telephony device associated with the ported-to number. Upon the expiration of the duration of time, the portability component 105 initiates one or more notifications of the expiration of the duration of time to the management component 110 and/or the provisioning components 245 and 250. In one example, the portability component 105 initiates a notification to the management component 110 to remove the port of the directory number to the location routing number. In another example, the portability component 105 initiates a notification to the management component 110 to alter the port of the directory number to port the directory number back to the ported-from telephony number. The portability component 105 initiates a notification to the provisioning components 245 and 250 to remove and/or alter the association. The timer components 215 and/or 220 receive and store one or more values for one or more durations of time for one or more directory numbers. The timer components 215 and/or 220 employ a value of a duration of time to determine an expiration of the duration of time. In one example, the timer component 215 sends a notification of the expiration of the duration of time for a directory number to the portability component 105. In another example, the timer component 220 sends a notification of the expiration of the duration of time to the subscriber database 230. The subscriber databases 225 and 230 and the switch components 235 and 240 in one example cooperate to provide and/or to withhold service for one or more telephony devices associated with the networks 115 and 120. The subscriber databases 225 and/or 230 in one example comprise one or more subscriber entries associated with one or more directory numbers. The subscriber entries in one example comprise one or more ported-out flags. The ported-out flags indicate a status of a directory number. If a ported-out flag is set, the directory number is ported from a network and/or a set of services. If the ported-out flag is not set (i.e., the ported-out flag is cleared), the directory number is not ported from the network and/or the set of services. For example, where the ported-out flag is set in a subscriber entry for a directory number in the subscriber database 225, the subscriber database 225 and the switch component 235 cooperate to withhold providing service to the directory number. In one example, the subscriber database 225 clears the ported-out flag associated with the directory number upon receipt of a notification of an expiration of the duration of time from the provisioning component 245. The subscriber databases 225 and 230 and the switch components 235 and 240 in one example cooperate to provide one or more messages to a user of a telephony device associated with a directory number. In one example, the subscriber database 225 and the switch component 235 cooperate to provide a “failure to pay”, or deadbeat, message to one or more callers to the directory number upon receipt of an expiration of the duration of time. In another example, the subscriber database 225 and the switch component 235 cooperate to provide a message to the user of the telephony device associated with the directory number indicating a period of time remaining until the expiration of the duration of time to port the directory number. An illustrative description of exemplary operation of the apparatus 100 is presented, for explanatory purposes. Turning to FIG. 3, the provisioning component 245 requests to port a directory number from the network 115 to the network 120. In STEP 305, the provisioning component 245 initiates a request to port the directory number to the portability component 105. The request comprises a ported-from number as the directory number, a ported-to number as a location routing number, an identifier associated with the timer component 215, an identifier associated with the provisioning component 250, an identifier associated with the provisioning component 245, and a value for a duration of time of five days. In STEP 310, the portability component 105 employs the identifier associated with the provisioning component 250 to update the provisioning component 250. In STEP 315, the portability component 105 employs the identifier associated with the timer component 215 to provide the value for the duration of time of five days to the timer component 215. In STEP 320, the portability component 105 updates the management component 110 with the identifiers. In STEP 325, the management component 110 provides the association between the directory number and the location routing number to the local portability database 205. In STEP 330, the management component 110 provides the association between the directory number and the location routing number to the local portability database 210. The local portability database 210 stores the association between the directory number and the location routing number. In STEP 335, the timer component 215 sends a notification of an expiration of the duration of time associated with the directory number to the portability component 105. In STEP 340, the portability component 105 notifies the management component 110 of the expiration of the duration of time. In STEP 345, the management component 110 notifies the local portability database 205 upon the expiration of the duration of time. The management component 110 removes the association between the directory number and the location routing number. In STEP 350, the management component 110 notifies the local portability database 210 to remove the association between the directory number and the location routing number. The local portability database 210 removes the entry. In STEP 355, upon receipt of the notification of the expiration of the duration of time, the portability component 105 employs the identifier associated with the provisioning component 245 to update the provisioning component 245 to port the directory number back to an initial state. In STEP 360, the portability component 105 employs the identifier associated with the provisioning component 250 to update the provisioning component 250 to terminate service for the telephony device. Turning to FIG. 4, the portability component 105 updates one or more network components to make permanent a port of a directory number from the network 115 to the network 120. In STEP 405, the provisioning component 245 initiates a request to the portability component 105 to make permanent the port of the directory number. The portability component 105 removes the association of the directory number. In STEP 410, the portability component 105 employs an identifier associated with the timer component 215 to update the timer component 215. The timer component 215 removes the value for the duration of time to port the directory number. In STEP 415, the portability component 105 employs an identifier associated with the provisioning component 250 to update the provisioning component 250 to make permanent the port for the directory number. In STEP 420, the portability component 105 employs an identifier associated with the provisioning component 245 to update the provisioning component 245 to make permanent the port for the directory number. In STEPS 425 and 430, the provisioning components 245 and 250 update the subscriber databases 225 and 230 respectively. The directory number is permanently ported from the network 115 to the network 120. Turning to FIG. 5, the portability component 105 receives a request to reset a value for a duration of time to port a directory number. In STEP 505, the provisioning component 245 sends the request to the portability component 105 to provide a second value for the duration of time to port the directory number from the network 115 to the network 120. In STEP 510, the portability component 105 communicates with the timer component 215 to provide the second value for the duration of time through employment of an identifier associated with the timer component 215. The timer component 215 updates a timer associated with the directory number with the second value. The apparatus 100 in one example comprises a plurality of components such as computer software and/or hardware components. A number of such components can be combined or divided in the apparatus 100. An exemplary component of the apparatus 100 employs and/or comprises a set and/or series of computer instructions written in or implemented with any of a number of programming languages, as will be appreciated by those skilled in the art. The apparatus 100 in one example employs at least one computer-readable signal-bearing medium. One example of a computer-readable signal-bearing medium for the apparatus 100 comprises an instance of a recordable data storage medium such as one or more of a magnetic, electrical, optical, biological, and atomic data storage medium. The recordable data storage medium in one example comprises the storage devices 203, 206, 207, 208, 209, 211, and 212. In another example, a computer-readable signal-bearing medium for the apparatus 100 comprises a modulated carrier signal transmitted over a network comprising or coupled with the apparatus 100, for instance, one or more of a telephone network, a local area network (“LAN”), the Internet, and a wireless network. An exemplary component of the apparatus 100 employs and/or comprises a set and/or series of computer instructions written in or implemented with any of a number of programming languages, as will be appreciated by those skilled in the art. The steps or operations described herein are just exemplary. There may be many variations to these steps or operations without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified. Although exemplary implementations of the invention have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims. | <SOH> BACKGROUND <EOH>Number portability (“NP”) is a telecommunications network feature that enables a user of a telephony device to retain their directory number when changing service providers, service types, and/or locations. For example, the user may desire to temporarily try out a new telephony device and/or a new set of services while retaining their directory number. So, to port the directory from a first service provider to a second service provider, databases associated with the first and second service providers in one example are manually updated. Before porting the directory number, the user receives service from the first service provider. Upon porting the directory number to the second service provider, the user receives service from the second service provider. To port the directory number between the service providers, one or more employees of the second service provider manually enter an association between the directory number and a location routing number into a database associated with the second service provider. The employees of the second service provider may also request that the first service provider manually updates a database associated with the first service provider. After porting the number from the first service provider to the second service provider, the user may desire to restart service with the first service provider. So, the directory number must be ported back from the second service provider to the first service provider and the databases associated with the first and second service providers must be manually updated a second time. Manual updating of the databases may take several days. As one shortcoming, the user of the telephony device associated with the directory number may not receive service from either of the service providers until both the databases are updated. It is desirable for the user of the telephony device associated with the directory number to receive continuous service. Thus, a need exists to reduce an amount of time required to port a directory number between service providers. A further need exists to reduce a duration of a potential service interruption experienced by a user while porting the directory number. | <SOH> SUMMARY <EOH>The invention in one implementation encompasses an apparatus. The apparatus comprises a portability component that automatically updates one or more provisioning components to port a directory number for a duration of time. Another embodiment of the invention encompasses a method. One or more provisioning components are automatically updated to port a directory number for a duration of time. Yet another embodiment of the invention encompasses an article. The article comprises one or more computer-readable signal-bearing media. The article comprises means in the one or more media for automatically updating one or more provisioning components to port a directory number for a duration of time. | 20040130 | 20101228 | 20050804 | 58550.0 | 0 | NGUYEN, KHAI N | PORTING A DIRECTORY NUMBER FOR A DURATION OF TIME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,768,454 | ACCEPTED | Hose connector | A hose connector includes a cylindrical elongated member having a first and second end, a first and second inner sleeve rotatably mounted on the cylindrical member, and a first and second outer sleeve capable of connecting to the respective first and second inner sleeves. | 1. A hose connector comprising: a cylindrical elongated member having a first and second end; a first and second inner sleeve rotatably mounted on said cylindrical member; and a first and second outer sleeve capable of connecting to said respective first and second inner sleeves, wherein the smallest diameter of the first and second inner sleeves is sufficiently greater than a diameter of the an outside surface of the cylindrical member to allow the first and second inner sleeves to rotate around the cylindrical member, and the smallest diameter of the first and second inner sleeves is smaller than a diameter of a raised section of the cylindrical member for retaining the inner sleeves on the cylindrical member. 2. The hose connector of claim 1, further comprising a first and second gasket capable of seating on the cylindrical member. 3. The hose connector of claim 3, wherein said first and second ends of said cylindrical member include a raised section having a groove therein, and wherein said first and second gaskets are capable of seating in said respective grooves of said first and second ends of said cylindrical member. 4. The hose connector of claim 1, wherein said first and second inner sleeves are threaded and said first and second outer sleeves are reverse-threaded relative to said first and second inner sleeves to allow the respective inner and outer sleeves to be screwed together to form a first and second combined sleeve. 5. The hose connector of claim 1, wherein said first and second outer sleeves include an inside surface, at least a portion of which includes threads for engaging a hose being connected to the hose connector. 6. The hose connector of claim 5, wherein the threads are dimensioned to threadably engage corrugations on said hose. 7. A hose connector comprising: a cylindrical elongated member having a first and second end; a first and second inner sleeve rotatable mounted on said cylindrical member; and a first and second outer sleeve capable of connecting to said respective first and second inner sleeves, wherein the outer sleeves include a first end having an outer surface with a diameter that is smaller than a diameter of an inner surface of the cylindrical member at the first and second end of the cylindrical member to allow for insertion of the first end of the outer sleeves into a respective first or second end of the cylindrical member. 8. The hose connector of claim 7, wherein the smallest diameter of the first and second inner sleeves is sufficiently greater than a diameter of the an outside surface of the cylindrical member to allow the first and second inner sleeves to rotate around the cylindrical member. 9. The hose connector of claim 8, wherein the smallest diameter of the first and second inner sleeves is smaller than a diameter of a raised section of the cylindrical member for retaining the inner sleeves on the cylindrical member. 10. The hose connector of claim 1, wherein said first and second inner sleeves and said first and second outer sleeves include a gripping mechanism. 11. The hose connector of claim 10, wherein the gripping mechanism comprises ribs. 12. A hose assembly comprising: a hose connector including: a cylindrical elongated member having a first and second end; a first and second inner sleeve rotatably mounted on said cylindrical member, wherein the smallest diameter of the first and second inner sleeves is sufficiently greater than a diameter of the an outside surface of the cylindrical member to allow the first and second inner sleeves to rotate around the cylindrical member, and the smallest diameter of the first and second inner sleeves is smaller than a diameter of a raised section of the cylindrical member for retaining the inner sleeves on the cylindrical member; and a first and second outer sleeve connected to said respective first and second inner sleeves to form a first and second combined sleeve, said first and second outer sleeves including threads on an inside surface; and at least one hose having corrugations, said corrugations threadably engaged with the threads of the first and second outer sleeves. 13. The hose assembly of claim 12, wherein said hose connector further includes a first and second gasket seated on said cylindrical member. 14. The hose assembly of claim 12, wherein said inner and outer sleeves and said hose engaged thereby are capable of rotating about said cylindrical member. 15. A method of connecting two hoses comprising: providing a hose connector comprising a cylindrical elongated member having a first and second end, a first and second inner sleeve rotatably mounted on said cylindrical member, and a first and second outer sleeve having threads on an inside surface, and connected to said respective first and second inner sleeves to form a first and second combined sleeve, providing at lease one hose including corrugations; and screwing the hose onto the hose connector. 16. The method of claim 15, wherein the step of screwing the hose onto the hose connector comprises placing the hose into an end of the outer sleeve and twisting the combined sleeve or the hose, thereby threadably engaging the corrugations of the hose with the threads of the outer sleeves. 17. A hose connector comprising: a cylindrical elongated member having a first and second end; and a first and second sleeve disposed on said cylindrical member, at least said first sleeve being capable of rotation about said cylindrical member, said first and second sleeves capable of threadably engaging at least one hose, wherein the smallest diameter of the first sleeve is sufficiently greater than a diameter of the an outside surface of the cylindrical member to allow the first sleeve to rotate around the cylindrical member, and the smallest diameter of the first sleeve is smaller than a diameter of a raised section of the cylindrical member for retaining the first sleeve on the cylindrical member. 18. The hose connector of claim 17, further comprising a first gasket capable of seating on said cylindrical member beneath said first sleeve. 19. The hose connector of claim 17, wherein said first sleeve comprises a first inner sleeve and a first outer sleeve which are capable of connecting to one another, and said second sleeve comprises a second inner sleeve and a second outer sleeve which are capable of connecting to one another. 20. The hose connector of claim 17, wherein said second sleeve is capable of rotation about said cylindrical member. 21. The hose connection of claim 17, wherein said first and second sleeves have threaded engagement means for threadedly engaging a corrugated pipe. | FIELD OF THE INVENTION The present invention relates to hose connectors, and more particularly to hose connectors for connecting and disconnecting hoses for applying loosefill insulation. BACKGROUND OF THE INVENTION Insulation may be dispensed in a variety of ways. Generally, a hose is used to dispense the loosefill insulation. The operator positions a hose nozzle in a desired direction and dispenses the insulation from the loosefill source into the area at which the nozzle is aimed. Transporting the loosefill insulation from the source of loosefill into an area, such as an attic or basement, often requires the use of more than a single hose. Hose connectors are employed to connect and extend the hosing to reach longer distances. Typically, these hose connectors are 6″ long steel tubes. The hoses fit over the ends of these tubes and are secured to the tube by screw-type metal hose clamps. The use of such tubes and clamps is time consuming and requires a screw driver to secure the hoses, and are also subject to corrosion and deformation, and tend to cause the hoses to wear prematurely adjacent the clamp. Further, the use of such tubes and clamps does not allow for the rotation of the hoses relative to the connector once the clamps are tightened. U.S. Pat. No. 4,625,998 to Draudt et al. discloses a swivel hose coupling including a swivel insert that connects to the end of a hose and a swivel hose end piece which is rotatably connected to a hose end by the swivel insert. The swivel hose end piece has an internal groove in which an exterior portion of the swivel insert is rotatably received. Prior to assembly of the swivel hose end piece onto the swivel insert, the end piece should be heated to approximately 100°-110° F. to make it more pliable so that it will stretch, thus facilitating an easier pushing of the end piece onto the swivel insert after the swivel insert has been screwed onto the hose end. U.S. Pat. No. 6,102,445 to Thomas discloses a sealed coupling system for metal flexible hoses which includes a fitting assembly with inner and outer fittings adapted for threaded interconnection on the end of the flexible hose. The inner fitting includes a bore which receives a washer assembly with an O-ring for forming a sealing connection, a backer ring and an expandable washer. The expandable washer is selectively receivable on the corrugations of the flexible hose and functions to retain the fitting and washer assemblies securely in place and to prevent pull-out of the coupling while providing a positive connection to the hose whereby the O-ring gasket can be compressed for sealing. U.S. Pat. No. 4,795,197 to Kaminski et al. discloses a coupling for corrugated flexible hoses which includes two generally semi-cylindrical portions which are molded as a single unit with an integral hinge and locking structure. The inner surface of the cylindrical member is corrugated to correspond to the corrugations on the flexible hose, and an end portion of the coupling device includes an annular groove which mates with a flange on the outlet. The locking structure automatically latches as the semi-cylindrical portions are closed around the hose and the flange. Such a coupling does not allow for rotation of the hoses. Thus, there is currently a need for an improved hose connector and method for connecting hoses between a loosefill source and an area of laying the loosefill insulation. SUMMARY OF THE INVENTION The present invention comprises a hose connector comprising a cylindrical elongated member having a first and second end, a first and second inner sleeve rotatably mounted on the cylindrical member, and a first and second outer sleeve capable of connecting to the respective first and second inner sleeves. The hose connector and method as described herein may advantageously be used to connect hoses, such as loose fill insulation hoses. Unlike current connectors that are time consuming, unyielding and require tools to employ, the present connector allows for rotation of the hoses, does not require the use of tools to use, and provides for quick assembly and disassembly of the hoses. According to another aspect of this invention, a hose assembly comprises a hose connector and at least one hose. The hose connector comprises a cylindrical elongated member having a first and second end, a first and second inner sleeve rotatably mounted on the cylindrical member, and a first and second outer sleeve, each connected to the respective first and second inner sleeves to form a first and second combined sleeve and including threads on an inside surface thereof. The at least one hose includes corrugations. The corrugations are threadably engaged with the threads of the first and second outer sleeves. According to another aspect, a method of connecting two hoses comprises providing a hose connector, providing at least one hose having corrugations, and screwing the hose onto the hose connector. The hose connector includes a cylindrical elongated member having a first and second end, a first and second inner sleeve rotatably mounted on the cylindrical member, and a first and second outer sleeve, each having threads on an inside surface thereof, and connected to the respective first and second inner sleeves to form a first and second combined sleeve. According to a further aspect, a hose connector includes a cylindrical elongated member having a first and second end, and a first and second sleeve rotatably mounted on the cylindrical member and capable of threadably engaging at least one hose. The above and other features of the present invention will be better understood from the following detailed description of the preferred embodiments of the invention that is provided in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate preferred embodiments of the invention, as well as other information pertinent to the disclosure, in which: FIG. 1 is an exploded view of a hose connector according to one aspect of the present invention. FIG. 2 is a side elevational view the hose connector of FIG. 1, shown connecting two hoses. FIG. 3 is a partial cross-sectional view of an outer sleeve of the hose connector of FIG. 1, shown with an inserted hose. FIG. 4 is a side elevational view of an alternative hose connector. DETAILED DESCRIPTION This description of the exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description, relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. While the hose connectors of this invention are useful in loosefill insulation applications, the invention can also serve other end uses, such as drainage, irrigation, fluid transfer, HVAC automotive, and aerospace applications. The connectors of this invention are particularly useful in connecting corrugated pipe. Referring to FIG. 1, hose connector 10 comprises a cylindrical elongated member 20, a first inner sleeve 30, a second inner sleeve 32, a first outer sleeve 50, and a second outer sleeve 52. Preferably, the hose connector 10 also includes a first gasket 40 and a second gasket 42. The elongated member 20, first and second inner sleeves 30, 32, and first and second outer sleeves 50, 52 may be formed of any suitable material, such as, for example, metal or plastic. Also, the diameter of the cylindrical member 20, sleeves, 30, 32, 50, 52, and gaskets 40, 42 may vary in accordance with the diameter of the hoses which are being connected via the hose connector. Cylindrical elongated member 20 includes a first end 22, a second end 24, a main body portion 25, and an inner surface (not shown). First end 22 and second end 24 include a raised portion 26 preferably having a groove 28 therein. The raised portion 26 of the first and second ends 22, 24 acts to keep the first and second inner sleeves from sliding off the main body portion 25. The grooves 28 acts to retain a respective gasket 40, 42. First and second inner sleeves 30, 32 include an inside surface (not shown) and an outside surface 36. At least a portion of the inside surface of each inner sleeve 30, 32 is preferably threaded for mating with a respective and reverse threaded outer sleeve 50, 52. Alternatively, the inner sleeves 30, 32 and outer sleeves 50, 52 may include other mating means for interlocking the first inner sleeve with the first outer sleeve and the second inner sleeve with the second outer sleeve, such as, for example, a snap-lock mechanism. The smallest diameter of the inside surface of the inner sleeves is preferably sufficiently greater than the diameter the outside surface 27 of the main body portion 25 of the cylindrical member 20 to allow for the rotational movement of the sleeves 30, 32 relative to the cylindrical member 20. The smallest diameter of the inside surface of the inner sleeves, however, is preferably smaller than the diameter of the raised portion 26 of the first and second ends 22, 24 of the elongated member 20 to retain the inner sleeves on the elongated member and prevent them from slipping off the ends 22, 24. Preferably, the outside surface 36 of the inner sleeves 30, 32 include a gripping mechanism, such as, for example, ribs 39 for facilitating the connection or disconnection of a respective inner and outer sleeve. First and second gaskets 40, 42 are preferably formed of rubber or other elastomeric material and, when installed on the hose connector 10, are seated within the grooves 28 of the raised portions 26. The gaskets 40, 42 provide light resistance against rotation of the inner and outer sleeves, and also aid in preventing the hose connector 10 from seeping air. Outer sleeves 50, 52 include a first end 54, a second end 56, an inside surface 58, and an inner sleeve mating portion 60. At least a portion of the inside surface 58 is threaded for facilitating the insertion of the corrugated hoses 70, 72 (see FIG. 3). The threads 59 are dimensioned to threadably engage the corrugations 74 on the hoses 70, 72, and preferably facilitate a substantially air tight connection. The diameter of the outer surface 62 of the first end 54 of outer sleeves 50, 52 is smaller than the diameter of the inner surface of the cylindrical member 20 to allow for insertion of the first end 54 of the outer sleeves 50, 52 into the respective first 22 or second 24 end of the cylindrical member 20. Preferably the inner sleeve mating portion 60 is threaded for mating with a respective inner sleeve 30, 32. However, as stated above, the mating portion may comprise other mating means, such as, for example, a snap-lock mechanism for facilitating a connection with a respective inner sleeve. The outer surface 64 of the second end 56 of the outer sleeves 50, 52, preferably include a gripping mechanism, such as, for example, ribs 66 for facilitating the connection of a respective inner and outer sleeve. Referring to FIG. 2, the hose connector 10 is shown connecting a first and second hose 70, 72. Before the hoses are connected via the hose connector 10, the components of the hose connector are assembled by placing the gaskets 40, 42 into the grooves 28 of the raised portions 26 of the elongated member 20, inserting the first end 54 of the outer sleeves 50, 52 into a respective first or second end 22, 24 of the elongated body 20, and then connecting, preferably threadably connecting, the respective inner and outer sleeves to form a first and second combined sleeve 90, 92. The first and second hoses 70, 72 comprise corrugations 74 on at least an outside surface. The corrugations 74 may comprise separate alternating ribs and grooves, or alternatively, a substantially continuous helical or spiral rib with a corresponding substantially continuous helical or spiral groove, which resembles the threads of a screw. To connect the hoses 70, 72 to respective ends of the hose connector 10, an end of each hose 70, 72 is placed into the second end 56 of the respective outer sleeve 50, 52. The combined sleeves 90, 92 are then twisted causing the corrugations on the hoses 70, 72 to threadably engage the threads 59 on the inside surface 58 of the outer sleeves 50, 52. Preferably, the threads 59 on the inner surface 58 of the first outer sleeves 50, 52 are configured such that the hoses 70, 72 are drawn into hose connector 10 when the combined sleeves 90, 92 are rotated in the direction shown by the arrows in FIG. 2. To disconnect the hoses, the combined sleeves 90, 92 are rotated in the opposite direction shown by the arrows. The combined sleeves 90, 92 can rotate around the main body portion 25 allowing the hoses 70, 72 to swivel. The resistance provided by gaskets 40, 42, in addition to the outward force applied by the hoses against the threads 59 of the inside surface 58 of the outer sleeves 50, 52, helps prevent the combined sleeves 90, 92 from unscrewing and releasing the hoses from the hose connector 10. Referring to FIG. 4, in an alternative embodiment, the hose connector 100 comprises a cylindrical elongated member 110 having a first and second end (not shown), and a first and second sleeve 120, 122 rotatably mounted on the cylindrical member 110. Preferably, the hose connector 100 also includes a first and second gasket (not shown). Hose connector 100 is substantially similar to hose connector 10 described above, with the exception that the first and second inner and outer sleeves 30, 32, 50, 52 of hose connector 10 are formed of a single piece of material as first sleeve 120 and second sleeve 122, and thus do not need to be connected together. Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention. For example, in addition to connecting two hoses, the hose connector can be used to connect a hose, for example, to an insulation dispensing apparatus, a pipe, another coupling device, or the like. | <SOH> BACKGROUND OF THE INVENTION <EOH>Insulation may be dispensed in a variety of ways. Generally, a hose is used to dispense the loosefill insulation. The operator positions a hose nozzle in a desired direction and dispenses the insulation from the loosefill source into the area at which the nozzle is aimed. Transporting the loosefill insulation from the source of loosefill into an area, such as an attic or basement, often requires the use of more than a single hose. Hose connectors are employed to connect and extend the hosing to reach longer distances. Typically, these hose connectors are 6″ long steel tubes. The hoses fit over the ends of these tubes and are secured to the tube by screw-type metal hose clamps. The use of such tubes and clamps is time consuming and requires a screw driver to secure the hoses, and are also subject to corrosion and deformation, and tend to cause the hoses to wear prematurely adjacent the clamp. Further, the use of such tubes and clamps does not allow for the rotation of the hoses relative to the connector once the clamps are tightened. U.S. Pat. No. 4,625,998 to Draudt et al. discloses a swivel hose coupling including a swivel insert that connects to the end of a hose and a swivel hose end piece which is rotatably connected to a hose end by the swivel insert. The swivel hose end piece has an internal groove in which an exterior portion of the swivel insert is rotatably received. Prior to assembly of the swivel hose end piece onto the swivel insert, the end piece should be heated to approximately 100°-110° F. to make it more pliable so that it will stretch, thus facilitating an easier pushing of the end piece onto the swivel insert after the swivel insert has been screwed onto the hose end. U.S. Pat. No. 6,102,445 to Thomas discloses a sealed coupling system for metal flexible hoses which includes a fitting assembly with inner and outer fittings adapted for threaded interconnection on the end of the flexible hose. The inner fitting includes a bore which receives a washer assembly with an O-ring for forming a sealing connection, a backer ring and an expandable washer. The expandable washer is selectively receivable on the corrugations of the flexible hose and functions to retain the fitting and washer assemblies securely in place and to prevent pull-out of the coupling while providing a positive connection to the hose whereby the O-ring gasket can be compressed for sealing. U.S. Pat. No. 4,795,197 to Kaminski et al. discloses a coupling for corrugated flexible hoses which includes two generally semi-cylindrical portions which are molded as a single unit with an integral hinge and locking structure. The inner surface of the cylindrical member is corrugated to correspond to the corrugations on the flexible hose, and an end portion of the coupling device includes an annular groove which mates with a flange on the outlet. The locking structure automatically latches as the semi-cylindrical portions are closed around the hose and the flange. Such a coupling does not allow for rotation of the hoses. Thus, there is currently a need for an improved hose connector and method for connecting hoses between a loosefill source and an area of laying the loosefill insulation. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention comprises a hose connector comprising a cylindrical elongated member having a first and second end, a first and second inner sleeve rotatably mounted on the cylindrical member, and a first and second outer sleeve capable of connecting to the respective first and second inner sleeves. The hose connector and method as described herein may advantageously be used to connect hoses, such as loose fill insulation hoses. Unlike current connectors that are time consuming, unyielding and require tools to employ, the present connector allows for rotation of the hoses, does not require the use of tools to use, and provides for quick assembly and disassembly of the hoses. According to another aspect of this invention, a hose assembly comprises a hose connector and at least one hose. The hose connector comprises a cylindrical elongated member having a first and second end, a first and second inner sleeve rotatably mounted on the cylindrical member, and a first and second outer sleeve, each connected to the respective first and second inner sleeves to form a first and second combined sleeve and including threads on an inside surface thereof. The at least one hose includes corrugations. The corrugations are threadably engaged with the threads of the first and second outer sleeves. According to another aspect, a method of connecting two hoses comprises providing a hose connector, providing at least one hose having corrugations, and screwing the hose onto the hose connector. The hose connector includes a cylindrical elongated member having a first and second end, a first and second inner sleeve rotatably mounted on the cylindrical member, and a first and second outer sleeve, each having threads on an inside surface thereof, and connected to the respective first and second inner sleeves to form a first and second combined sleeve. According to a further aspect, a hose connector includes a cylindrical elongated member having a first and second end, and a first and second sleeve rotatably mounted on the cylindrical member and capable of threadably engaging at least one hose. The above and other features of the present invention will be better understood from the following detailed description of the preferred embodiments of the invention that is provided in connection with the accompanying drawings. | 20040130 | 20110301 | 20050804 | 68507.0 | 0 | BOCHNA, DAVID | HOSE CONNECTOR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,768,644 | ACCEPTED | Apparatus and method for calibration of spectrophotometers | An apparatus and related method for optical calibration of spectrophotometers is described. The apparatus is a calibration plate including one or more cuvettes filled with solutions of interest. The cuvettes are sealed to prevent evaporation. The cuvettes also possess a compressible component to allow for expansion of the solution and a bubble control apparatus to ensure that the compressible component does not intersect the beam path. A piece of neutral density glass is optionally included in the apparatus to track optical changes of the solutions over time. | 1. An apparatus for calibrating a spectrophotometer, the apparatus comprising: a calibration plate having a first face, a second face, means for removably retaining therein one or more cuvettes, and one or more light beam ports from said first face through to said second face, or from said second face through to said first face. 2. The apparatus as claimed in claim 1 further comprising one or more cuvettes retained in said means for removably retaining therein one or more cuvettes. 3. The apparatus as claimed in claim 2 wherein at least one of said one or more cuvettes is filled with a solution. 4. The apparatus as claimed in claim 3 wherein at least one of said one or more cuvettes is filled with a solution including one or more chromophores. 5. The apparatus as claimed in claim 1 further comprising means for retaining therein a Neutral Density (ND) glass filter. 6. The apparatus as claimed in claim 6 further comprising a ND glass filter retained in said means for retaining a ND glass filter. 7. The apparatus as claimed in claim 3 wherein each of said one or more cuvettes filled with a solution includes a top, the apparatus further comprising means for sealing said top. 8. The apparatus as claimed in claim 7 wherein said means for sealing said top includes a crimp-top seal. 9. The apparatus as claimed in claim 8 wherein said means for sealing said top includes a film disposed between said top and said crimp-top seal. 10. The apparatus as claimed in claim 2 wherein each of said one or more cuvettes is oriented within said means to present to the vertical beam spectrophotometer a fixed beam path through each of said one or more beam ports. 11. The apparatus as claimed in claim 3 wherein each of said solution-filled cuvettes includes a sealed top, an expansion allowance zone, and a compressible component therein. 12. The apparatus as claimed in claim 11 wherein said compressible material is a gas. 13. The apparatus as claimed in claim 12 wherein said gas is air. 14. The apparatus as claimed in claim 12 wherein each of said solution-filled cuvettes includes a bubble control apparatus configured and arranged to hold said gas in said expansion allowance zone when the apparatus is in use to calibrate the vertical beam spectrophotometer. 15. The apparatus as claimed in claim 14 wherein said bubble control apparatus is a shelf. 16. The apparatus as claimed in claim 15 wherein said shelf is fabricated of a rigid material. 17. The apparatus as claimed in claim 16 wherein said rigid material is glass. 18. The apparatus as claimed in claim 14 wherein said bubble control apparatus is a non-metallic tube. 19. The apparatus as claimed in claim 14 wherein said bubble control apparatus is a bladder containing said gas therein. 20. The apparatus as claimed in claim 14 wherein said bubble control apparatus is a porous material containing said gas therein. 21. The apparatus as claimed in claim 14 wherein said bubble control apparatus consists of a combination of two or more of a rigid shelf, a non-metallic tube, a bladder, and a porous material. 22. A method for calibrating a spectrophotometer comprising the steps of: a. placing a calibration plate including one or more solution-filled cuvettes in the spectrophotometer, said calibration plate including one or more beam ports associated with each of said one or more solution-filled cuvettes, each of said one or more solution-filled cuvettes including one or more chromophores of reference light absorbance therein, each of said solution-filled cuvettes configured and arranged to present a fixed beam path to the spectrophotometer; b. measuring the light absorbance of each of said solution-filled cuvettes; c. obtaining reference light absorbance values of the one or more solution-filled cuvettes from a reference spectrophotometer; and d. comparing the measured light absorbance values with the reference light absorbance values. 23. The method as claimed in claim 22 wherein the calibration plate further includes a Neutral Density (ND) glass filter, the method further comprising the step of evaluating the light absorbance of each of said one or more solution-filled cuvettes over time in relation to the light absorbance of said ND glass filter. 24. The method as claimed in claim 23 wherein the step of evaluating the light absorbance of each of said one or more solution-filled cuvettes over time includes the steps of: a. measuring the light absorbance of the ND glass filter and one or more of said one or more solution-filled cuvettes at a first time; b. recording the light absorbance values of said ND glass filter and said one or more solution-filled cuvettes at said first time; c. measuring the light absorbance of the ND glass filter and one or more of said one or more solution-filled cuvettes at a second time; and d. comparing the light absorbance values from said measuring at said first time and said measuring at said second time. 25. A cuvette for calibrating a spectrophotometer, the cuvette comprising a top with a crimp seal, an expansion allowance zone, and a compressible component therein. 26. The cuvette as claimed in claim 25 wherein the compressible component is a gas. 27. The cuvette as claimed in claim 25 further comprising a non-metallic film disposed between said top and said crimp seal. 28. The cuvette as claimed in claim 25 further comprising a solution with one or more chromophores of one or more reference absorbances. | CROSS-REFERENCE TO RELATED APPLICATION The present invention relates to U.S. patent application Ser. No. 10/021,112, entitled “PHOTOMETRIC CALIBRATION OF LIQUID VOLUMES” filed Dec. 12, 2001, now U.S. Pat. No. 6,741,365 issued on May 25, 2004, and owned by a common assignee. The contents of the related application are incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to a device and method to calibrate spectrophotometers. More particularly, the present invention is a calibration plate with one or more references of selectable absorbance characteristics. BACKGROUND OF THE INVENTION Many analysis methods used in biology, chemistry, biotechnology, pharmaceutical and other industrial and research laboratories require accurate measurement and/or calibration of small volumes of liquids. These small volumes can range from nanoliters to microliters. Small volumes of liquid are dispensed from liquid delivery devices, such as pipettes, either sequentially or simultaneously into one or more vessels, such as cuvettes. In the interest of evaluating a large number of samples of liquid in a desired period of time, multiple charges of liquid samples may be dispensed into a plurality of vessels and analyzed simultaneously or sequentially. Preferably, the plurality of vessels is contained in one or more microtiter plates during testing. A microtiter plate contains a large number of individual wells and, for photometric measurements, a transparent base. Microtiter plates enable the ability to perform more research on a shorter time scale. As a result, they have become the standard analysis platform. The wide use of microtiter plates has resulted in the creation of entire classes of supporting equipment, including various types of analytical instrumentation, such as spectrophotometers capable of measuring individual wells within a plate. Under the photometric analysis method, the liquid sample under test is contained in the sample vessel and subjected to a light beam of a spectrophotometer. The amount of light from the incident light beam that passes through the vessel and the sample to an opposing detector of the spectrophotometer is dependent upon the characteristics of the liquid sample and the beam path length. It is important that the spectrophotometer provide accurate readings to ensure the accuracy of the liquid sample evaluation. The Beer-Lambert law defines one useful equation to determine an important characteristic of a sample. Specifically, Beer-Lambert states that the absorbance of light by a liquid sample under test equals the path length traversed by the light beam multiplied by the molar absorptivity of the chromophore in the liquid sample and the concentration of the chromophore in the liquid sample. Knowing the molar absorptivity of the chromophore, and the path length of light, the absorbance measurement provided by the spectrophotometer enables calculation of the particular concentration of the chromophore in the liquid sample. If the path length is not known, or known with sufficient accuracy, the concentration calculated will be approximate, and possibly outside a permitted error range. In addition, if the spectrophotometer is out of specification, the absorbance values obtained from the measurement will be in error and the calculated concentration also in error. It is therefore important to maintain an accurate calibration of the spectrophotometer. There are several types of spectrophotometers used to measure sample light absorbance. The conventional spectrophotometer transmits a light beam horizontally across the sample vessel. One type of specialized spectrophotometer transmits a light beam vertically through the sample vessel. In horizontal beam spectrophotometers, specific or fixed path lengths can generally be established, as the transmission path length is a function of the fixed cross section of the sample vessel rather than the volume of the sample in the vessel. However, the light transmission and detection method associated with a horizontal beam spectrophotometer is not suitable for use with a microtiter plate arrangement because a filled microtiter plate cannot be properly inserted into the horizontal beam path. Vertical beam spectrophotometers generally measure solution samples in microtiter plate wells. In one form, the vertical beam spectrophotometer transmits through the sample to a detector on the opposing side of the sample, either from above the sample down through it, or from below up through the sample. The path length for the sample is potentially—and likely—variable from one sample to the next in any given microtiter plate, since the path length is directly dependent upon the volume of sample solution in the well. Other factors that contribute to variations in path length are the ionic strength of the sample solution and the surface characteristics of the plate material, which together define the curvature characteristics of the solution meniscus. All of these factors result in an undefined path length and thus imprecision in vertical beam measurements. Nonetheless, vertical beam measurements are desirable in that multiple samples may be measured more quickly than is possible using a horizontal beam spectrophotometer. For a horizontal beam spectrophotometer, a common calibration approach used to determine the optical response for a given solution on a given instrument is to either create a series of dilutions of the solution of interest, or measure the solution in different, but known path lengths. In this approach, the ability to use a known path length allows for highly accurate determinations of the optical response of a solution and direct comparison of results from one spectrophotometer to another, or from one solution to another. One method presently used to calibrate horizontal and vertical beam spectrophotometers involves the measurement of light absorption through a known stable glass filter referred to as a Neutral Density (ND) filter. These filters are pieces of gray-tinted sheet glass that have nearly flat absorbance characteristics over a broad range of wavelengths. ND filters are commonly sent to reference laboratories for certified measurement, which provides results that are traceable to national standards. Once standardized, the ND filters are measured in the horizontal or vertical beam spectrophotometer and the absorbance results are compared to the reference laboratory results as a gauge of accuracy of the instrument. Although this is a common calibration method, a method that relies on ND filters alone gives little or no information about various optical effects such as: 1) out of band transmission (light passing from the source through the wavelength selection device and the sample to the detector, but outside of the desired wavelength range), 2) wavelength selection accuracy, 3) bandpass of the wavelength selection device, or 4) the shape of the transmission curve of the bandpass selection device. Therefore, reliance exclusively on instrument calibration using ND filters can lead to inaccurate absorbance results, especially when comparison is made between different instruments. One alternative method for calibrating vertical beam spectrophotometers involves the testing of samples of reference concentrations. Solutions containing different concentrations of the specific dye or chromophore are dispensed into different wells of a microtiter plate. Measurements of optical response are then conducted on the solution-filled wells. This method has several sources of error that limits its usefulness. First, the solution may not obey the Beer-Lambert law exactly, but may slightly deviate from a linear relationship between the concentration of dye and the resulting absorbance of the solution. Second, in order to provide quantitative results, highly accurate control over the amount of liquid dispensed into each well is required. Third, the exact dimensions of the wells in the microtiter plate must be known. Fourth, any meniscus present at the surface of the solution can add to the overall error since it directly affects the path length of light through the solution. Therefore, what is needed is an apparatus and related method for calibrating vertical beam spectrophotometers. The apparatus should be configured and arranged to be compatible with the arrangement of vertical beam spectrophotometers. The apparatus and method should allow the spectrophotometer operator to account for out of band transmissions, wavelength selection accuracy, the bandpass selection characteristics of the particular spectrophotometer, and the shape of the transmission curve of the bandpass selection. Further, the apparatus and method should resolve deviations in the linear relationship between the concentration of any reference dye in a sample under test and the resulting absorbance of the sample, be independent of the sample volume used to calibrate the spectrophotometer, allow accurate control over the path length, and eliminate meniscus errors in the light beam path. SUMMARY OF THE INVENTION The present invention is an apparatus and related method for calibrating spectrophotometers. The apparatus is configured and arranged to be compatible with the arrangement of vertical beam spectrophotometers, but may also be used with horizontal beam spectrophotometers. The apparatus and method enable a spectrophotometer operator to account for out of band transmissions, wavelength selection accuracy, the bandpass selection characteristics of the particular spectrophotometer, and the shape of the transmission curve of the bandpass selection. Further, the apparatus and method enables resolution of deviations in the linear relationship between the concentration of any reference dye in a sample under test and the resulting absorbance of the sample. The apparatus and related method provide accurate control over the path length, independent of the sample volume used to calibrate the spectrophotometer. Finally, the present invention eliminates meniscus errors associated with vertical beam measurements. While the description of the present invention will be directed to its advantageous use in a vertical beam spectrophotometer, it may also be used to calibrate horizontal beam spectrophotometers as well. These and other features are achieved in the present invention through the arrangement of a calibration plate having one or more sealed calibration cuvettes, each cuvette containing a solution having one or more chromophores of selectable reference concentrations. The present invention provides the operator with the ability to calibrate a vertical beam spectrophotometer at wavelengths that correspond exactly with the solutions to be tested, rather than using the broad spectral response of ND glass. For example, if a specific dye is used as an absorbance indicator in an assay, a set of solutions with increasing concentration of the specific dye may be made and inserted into the cuvettes in the calibration plate. The calibration plate is then used to calibrate the optical response of the vertical beam spectrophotometer over the expected absorbance range of the specific dye. The potential exists for incorporating more than one dye in each cuvette, so long as the multiple dyes do not significantly overlap in their absorbance responses. The present invention provides further advantage in its stability as a standard. Specifically, by sealing a standard in a cuvette retained in the calibration plate, the present invention minimizes changes in the standard caused by its prolonged exposure to air. An expansion zone is maintained within the cuvette to allow for thermal expansion and contraction of the solution therein during any thermal cycling. The expansion zone may be established in a variety of ways, including the means to be described herein. An expansion zone isolator is preferably included in the cuvette to isolate the expansion zone from the portion of the cuvette exposed to the spectrophotometer beam. Options on the form of the isolator will be described herein. The cuvette is oriented in the calibration plate such that it presents to the vertically aligned light beam a fixed path length through the solution. Further, that cuvette orientation displaces any meniscus from the beam path. In effect, the present invention provides a fixed path length, defined by the cross section of the cuvette, to a spectrophotometer, whether a vertical beam type or a horizontal beam type. The calibration plate includes means for retaining one or more cuvettes. Each retained cuvette defines a test section of the plate and may include a unique chromophore solution for calibration. However, it is to be understood that a single test cuvette may be deployed in the calibration plate, and that multiple cuvettes may contain the same chromophore solutions. Each test section of the plate may be further defined by one or more transparent beam ports for the light beam to pass to and through the solution in the retained cuvette. Each port establishes a fixed path length cell based on the cuvette's cross section. The calibration plate optionally includes a test section including an ND glass filter for selectable comparison to that standard. The calibration plate of the present invention includes one or more cuvettes that allow for insertion of solutions of interest. The solutions may be user defined and unique to the user's interests, or standardized solutions available commercially. In the later case, the filled cuvettes could be referenced to a spectrophotometer in the manufacturer's facility in the manner described in the related patent. The solution-filled cuvettes function as optical standards for calibrating the spectrophotometer response, or can be used to establish a relation between a given concentration of a solution and the absorbance exhibited. The solutions retained therein, the sealed arrangement of the cuvette(s), and the arrangement of the cuvette(s) within the calibration plate provide an effective means for spectrophotometer calibration, while avoiding the deficiencies in the vertical beam spectrophotometer calibration techniques in existence. These and other advantages and aspects of the apparatus and method of the present invention will become apparent upon review of the following detailed description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified perspective view of the calibration plate of the present invention with a plurality of cuvettes and an ND glass filter shown in phantom. FIG. 2A is a top view of a cuvette of the present invention showing the crimp top and a first expansion isolation means. FIG. 2B is a side view of the cuvette of FIG. 2A FIG. 3 is a top view of a cuvette of the present invention showing the crimp top and a second expansion isolation means. FIG. 3B is a side view of the cuvette of FIG. 3A. FIG. 4A is a top view of a cuvette of the present invention showing the crimp top and a third expansion isolation means. FIG. 4B is a side view of the cuvette of FIG. 4A. FIG. 5A is a top view of a cuvette of the present invention showing the crimp top and an optional expansion means. FIG. 5B is a side view of the cuvette of FIG. 5A. FIG. 6A is a top view of the cuvette of FIG. 5 showing the optional expansion means in a pressed form. FIG. 6B is a side view of the cuvette of FIG. 6A. DESCRIPTION OF THE PREFERRED EMBODIMENTS A calibration plate 10 of the present invention is shown in FIG. 1. The calibration plate 10 includes a plurality of light beam ports 11 through which a light beam may pass from a top calibration plate side 12, through one or more cuvettes 13 to a back side (not shown) of the calibration plate 10. (Alternatively, the light beam may pass from the back side to the top calibration plate side 12, dependent upon the operation of the particular spectrophotometer to be calibrated.) The frame of the calibration plate 10 that defines the structure of the calibration plate 10 is preferably fabricated of a rigid opaque material including, but not limited to, a metallic material, a rigid plastic material, or a combination thereof. The frame of the calibration plate 10 is preferably fabricated of two or more sections detachably connectable to one another. The cuvettes 13, and an optional ND glass filter plate 14 are removably captured in the calibration plate 10. Specifically, they may either be inserted into, or removed from, the calibration plate at a front end 15 thereof, or by connecting/disconnecting a top calibration plate 16 to/from a bottom calibration plate 17. With continuing reference to FIG. 1, each cuvette 13 is fabricated of a transparent material, such as glass. The cuvette 13 includes a body 18 of fixed cross sectional dimensions, an expansion allowance zone 19, a neck 20, and a head with a sealing cap 21 that seals the contents of the cuvette 13 therein. The expansion allowance zone 19 is positioned with respect the body 18 such that when the calibration plate 10 is positioned in a vertical beam spectrophotometer, the light beam ports are positioned only over the body 18 and not over the expansion allowance zone 19. Each cuvette 13 is preferably substantially filled with a liquid solution having a reference concentration or concentrations of one or more chromophores. Providing the calibration plate 10 with a plurality of cuvettes 13 allows for a range of absorbance values to be used to calibrate the optical response of a vertical beam spectrophotometer. The cuvettes 13 are formed in a substantially rectangular shape and formed with a flanged cuvette head to enable crimp sealing thereof. Hellma International of Plainview, N.Y., is capable of providing such a cuvette arrangement. The cuvettes 13 are placed flat in their long dimension within the calibration plate 10 when the calibration plate 10 is in use to allow the calibration solution to be sealed in the cuvette 13 for long periods of time. Unlike prior calibration cuvettes, the cuvettes 13 of the present invention are sealed by sealing cap 21 to minimize or substantially eliminate gas or fluid exchanges between the solution in the cuvettes and the external atmosphere. The sealing cap 21 is a crimp top seal applied with a crimping tool in a manner well known to those skilled in the art of crimping materials onto container tops. A nonporous film is applied to the cuvette head prior to affixing the crimp top to the cuvette 13. The film is preferably a polymeric film such as Parafilm™, a plastic wrap material manufactured by Pechiney Plastic Packaging of Menasha, Wis. The crimp top itself is a layered liner fabricated of a combination of an interior nonmetallic material and an exterior metallic material. For example, Wheaton Corp. of Millville, N.J., provides a commercially available material that includes an Aluminum/Teflon/Grey Butyl combination suitable as the crimp top material. Inside the sealed cuvettes 13, the expansion allowance zone 19 includes a compressible component that may be a bubble of gas, such as air. The compressible component is established in the cuvette 13 to allow for the solution to expand/contract due to thermal fluctuations. The compressible component must be held out of the light path defined by the ports 11, or it will adversely affect the absorbance values measured. A bubble control apparatus 23 is therefore used to hold the compressible component in place in the expansion allowance zone 19, out of the beam path near the top of the cuvette 13. While the compressible component may be displaced within the body 18 of the cuvette 13 during transport, shaking of the calibration plate 10 in any manner commonly employed in the field of liquid analysis, and the positioning of the calibration plate 10 in a vertical orientation will move the compressible component into the expansion allowance zone 19 where it is retained in place once the calibration plate 10 is returned to a horizontal orientation by the bubble control apparatus 23. As indicated, the ND glass filter 14 is an optional component of the calibration plate 10. The ND glass filter 14 may be used to check the long-term stability of the solution filled cuvettes 13. The ND glass filter 14 is preferably a gray-tinted sheet glass, which provides a non-changing, relatively flat absorbance over large portions of the visible spectrum. Unlike its application as a calibration device in and of itself, the optional ND glass filter 14 of the present invention is used mainly to test potential degradation of the solutions in the cuvettes 13. Specifically, the operator of the spectrophotometer under calibration may track the test responses of the solution-filled cuvettes 13 versus the ND glass filter 14, rather than using the ND glass filter 14 itself to calibrate the spectrophotometer. This is accomplished by establishing a relationship between the optical response of the ND glass filter 14 at a given wavelength, and the response of a solution-filled cuvette 13 at the same wavelength. This relation may be established by the manufacturer and passed to the user, or can be established directly by the user. The relationship can be a ratio or a simple difference of the absorbance measured at a given wavelength. As the calibration plate 10 is used in the field, a comparison may be made between the ND glass filter 14/solution-filled cuvette 13 relationship measured on the date of manufacture and the relationship measured on the current day. The manufacturer or user can set tolerance limits, which will define whether one or more specific cuvettes 13 of a particular calibration plate 10 is out of specification and in need of recertification. Thus, the ND glass filter 14 is preferably optionally used as a standard reference point for checking the solution-filled cuvettes 13. As illustrated in FIGS. 2A and 2B, a first bubble control apparatus 30 is a shelf positioned adjacent to top wall 31, spaced away from back wall 32, and located between sidewalls 33 and 34 of the cuvette 13. The shelf 30, preferably fabricated of Teflon™, provides a physical barrier and holds the compressible component (bubble 19) in place mainly by surface tension. Alternatively, the shelf 30 may be fabricated of glass and fused to the interior of the cuvette 13, such as on the interior of cuvette 13 between sidewalls 33 and 34 during cuvette manufacturing. For purposes of the description of this invention, a top wall is the portion of the cuvette 13 within the top calibration plate 16 that is adjacent to the light beam ports 11 when the cuvette 13 is in position in the calibration plate 10 as shown in FIG. 1, and a bottom wall is that portion of the cuvette 13 within the bottom calibration plate 17 that is adjacent to the underside of the calibration plate when the cuvette 13 is positioned therein. All references herein to a top wall or a bottom wall of the cuvette 13 are based on this orientation. As illustrated in FIGS. 3A and 3B, a second bubble control apparatus 40 is a piece of tubing, preferably fabricated of silicone, spaced adjacent to the top wall 41, away from the bottom wall 42, and wedged into place between sidewalls 43 and 44. It too operates as a physical barrier for entrapping the compressible component (again, in this instance, bubble 19). As illustrated in FIGS. 4A and 4B, a third bubble control apparatus 50 is a bladder filled with the appropriate amount of gas to allow for solution expansion. In the device of FIGS. 4A and 4B, the compressible component is contained within the bladder 50, which extends within the cuvette 13 substantially from top wall 51 toward bottom wall 52, about from sidewall 53 to sidewall 54, and partially into neck 20. The bladder 50 is sized to prevent its passage into the cuvette body 18. Each one of these control mechanisms ensures that the compressible material will remain out of the light path during spectrophotometer calibration. A fourth bubble control apparatus 60 is shown in FIGS. 5A-5B and 6A-6B. The apparatus 60 is a porous compressible or crushable material, such as foam. The material 60 wedged between cuvette top wall 61 and bottom wall 62. It may also be spaced between sidewalls 63 and 64, or spaced away therefrom. The bubble control apparatus 60 preferably extends into a portion of the neck 20. It holds a majority of the necessary gas in its interior. Under pressure, it will either compress to a smaller overall volume and re-expand upon release of that pressure, if compressible, or it will be crushed to that smaller volume and remain that way if the material 60 is only crushable. A crushable material may be preferred for the purpose of making a rapid visual determination of solution expansion within the cuvette 13. Specifically, as shown in FIGS. 5A and 5B, under standard temperature, the solution within the cuvette 13 is of a certain volume that, in combination with the volume of the material 60, essentially fills the cuvette 13. When a change of temperature causes the solution in the cuvette 13 to expand, the material 60 is compressed, thereby reducing its volume, as shown in FIGS. 6A and 6B. At all times the path length through the cross section of the cuvette 13 remains the same. It is to be understood that any of the cuvettes 13 may include a combination of any two or more of the bubble control apparatuses described herein. For example, the shelf 30 may be used to retain the bladder 50 in place, or the compressible material 60. Alternatively, the tubing 40 may be used in place of the shelf 30 for the same purpose. A method of calibrating a vertical-beam spectrophotometer using the calibration plate 10 includes the steps of inserting the solution-filled cuvettes 13 into the calibration plate 10, arranging the calibration plate 10 such that the compressible component is retained in the expansion allowance zone 18, and inserting the calibration plate 10 into the spectrophotometer. The cuvettes 13 are preferably filled with one or more solutions having one or more chromophores of reference absorbance characteristics and concentrations. The spectral analysis is then performed and absorbance values for the solutions in the cuvettes 13 are obtained. Those values are then compared with the reference values. The spectrophotometer operation may then be adjusted as necessary to establish a match of measured and reference absorbance values. The measurements are preferably re-run after spectrophotometer adjustment to confirm the results. The ND glass filter 14 may be used to confirm the absorbance values for the solutions in the cuvettes 13 over time as described hereinabove. The present invention is an apparatus to calibrate the optical response of a vertical bean spectrophotometer. It allows for use of absorbance standards specific to the chromophores of interest. In effect, a chromophore commonly analyzed in assays may be used to create specific absorbance characteristics and the response thereto may be acquired using a vertical beam spectrophotometer. While the present invention has been described with particular reference to certain embodiments of the calibration plate 10 and the designs of the cuvette 13, it is to be understood that it includes all reasonable equivalents thereof as defined by the following appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Many analysis methods used in biology, chemistry, biotechnology, pharmaceutical and other industrial and research laboratories require accurate measurement and/or calibration of small volumes of liquids. These small volumes can range from nanoliters to microliters. Small volumes of liquid are dispensed from liquid delivery devices, such as pipettes, either sequentially or simultaneously into one or more vessels, such as cuvettes. In the interest of evaluating a large number of samples of liquid in a desired period of time, multiple charges of liquid samples may be dispensed into a plurality of vessels and analyzed simultaneously or sequentially. Preferably, the plurality of vessels is contained in one or more microtiter plates during testing. A microtiter plate contains a large number of individual wells and, for photometric measurements, a transparent base. Microtiter plates enable the ability to perform more research on a shorter time scale. As a result, they have become the standard analysis platform. The wide use of microtiter plates has resulted in the creation of entire classes of supporting equipment, including various types of analytical instrumentation, such as spectrophotometers capable of measuring individual wells within a plate. Under the photometric analysis method, the liquid sample under test is contained in the sample vessel and subjected to a light beam of a spectrophotometer. The amount of light from the incident light beam that passes through the vessel and the sample to an opposing detector of the spectrophotometer is dependent upon the characteristics of the liquid sample and the beam path length. It is important that the spectrophotometer provide accurate readings to ensure the accuracy of the liquid sample evaluation. The Beer-Lambert law defines one useful equation to determine an important characteristic of a sample. Specifically, Beer-Lambert states that the absorbance of light by a liquid sample under test equals the path length traversed by the light beam multiplied by the molar absorptivity of the chromophore in the liquid sample and the concentration of the chromophore in the liquid sample. Knowing the molar absorptivity of the chromophore, and the path length of light, the absorbance measurement provided by the spectrophotometer enables calculation of the particular concentration of the chromophore in the liquid sample. If the path length is not known, or known with sufficient accuracy, the concentration calculated will be approximate, and possibly outside a permitted error range. In addition, if the spectrophotometer is out of specification, the absorbance values obtained from the measurement will be in error and the calculated concentration also in error. It is therefore important to maintain an accurate calibration of the spectrophotometer. There are several types of spectrophotometers used to measure sample light absorbance. The conventional spectrophotometer transmits a light beam horizontally across the sample vessel. One type of specialized spectrophotometer transmits a light beam vertically through the sample vessel. In horizontal beam spectrophotometers, specific or fixed path lengths can generally be established, as the transmission path length is a function of the fixed cross section of the sample vessel rather than the volume of the sample in the vessel. However, the light transmission and detection method associated with a horizontal beam spectrophotometer is not suitable for use with a microtiter plate arrangement because a filled microtiter plate cannot be properly inserted into the horizontal beam path. Vertical beam spectrophotometers generally measure solution samples in microtiter plate wells. In one form, the vertical beam spectrophotometer transmits through the sample to a detector on the opposing side of the sample, either from above the sample down through it, or from below up through the sample. The path length for the sample is potentially—and likely—variable from one sample to the next in any given microtiter plate, since the path length is directly dependent upon the volume of sample solution in the well. Other factors that contribute to variations in path length are the ionic strength of the sample solution and the surface characteristics of the plate material, which together define the curvature characteristics of the solution meniscus. All of these factors result in an undefined path length and thus imprecision in vertical beam measurements. Nonetheless, vertical beam measurements are desirable in that multiple samples may be measured more quickly than is possible using a horizontal beam spectrophotometer. For a horizontal beam spectrophotometer, a common calibration approach used to determine the optical response for a given solution on a given instrument is to either create a series of dilutions of the solution of interest, or measure the solution in different, but known path lengths. In this approach, the ability to use a known path length allows for highly accurate determinations of the optical response of a solution and direct comparison of results from one spectrophotometer to another, or from one solution to another. One method presently used to calibrate horizontal and vertical beam spectrophotometers involves the measurement of light absorption through a known stable glass filter referred to as a Neutral Density (ND) filter. These filters are pieces of gray-tinted sheet glass that have nearly flat absorbance characteristics over a broad range of wavelengths. ND filters are commonly sent to reference laboratories for certified measurement, which provides results that are traceable to national standards. Once standardized, the ND filters are measured in the horizontal or vertical beam spectrophotometer and the absorbance results are compared to the reference laboratory results as a gauge of accuracy of the instrument. Although this is a common calibration method, a method that relies on ND filters alone gives little or no information about various optical effects such as: 1) out of band transmission (light passing from the source through the wavelength selection device and the sample to the detector, but outside of the desired wavelength range), 2) wavelength selection accuracy, 3) bandpass of the wavelength selection device, or 4) the shape of the transmission curve of the bandpass selection device. Therefore, reliance exclusively on instrument calibration using ND filters can lead to inaccurate absorbance results, especially when comparison is made between different instruments. One alternative method for calibrating vertical beam spectrophotometers involves the testing of samples of reference concentrations. Solutions containing different concentrations of the specific dye or chromophore are dispensed into different wells of a microtiter plate. Measurements of optical response are then conducted on the solution-filled wells. This method has several sources of error that limits its usefulness. First, the solution may not obey the Beer-Lambert law exactly, but may slightly deviate from a linear relationship between the concentration of dye and the resulting absorbance of the solution. Second, in order to provide quantitative results, highly accurate control over the amount of liquid dispensed into each well is required. Third, the exact dimensions of the wells in the microtiter plate must be known. Fourth, any meniscus present at the surface of the solution can add to the overall error since it directly affects the path length of light through the solution. Therefore, what is needed is an apparatus and related method for calibrating vertical beam spectrophotometers. The apparatus should be configured and arranged to be compatible with the arrangement of vertical beam spectrophotometers. The apparatus and method should allow the spectrophotometer operator to account for out of band transmissions, wavelength selection accuracy, the bandpass selection characteristics of the particular spectrophotometer, and the shape of the transmission curve of the bandpass selection. Further, the apparatus and method should resolve deviations in the linear relationship between the concentration of any reference dye in a sample under test and the resulting absorbance of the sample, be independent of the sample volume used to calibrate the spectrophotometer, allow accurate control over the path length, and eliminate meniscus errors in the light beam path. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is an apparatus and related method for calibrating spectrophotometers. The apparatus is configured and arranged to be compatible with the arrangement of vertical beam spectrophotometers, but may also be used with horizontal beam spectrophotometers. The apparatus and method enable a spectrophotometer operator to account for out of band transmissions, wavelength selection accuracy, the bandpass selection characteristics of the particular spectrophotometer, and the shape of the transmission curve of the bandpass selection. Further, the apparatus and method enables resolution of deviations in the linear relationship between the concentration of any reference dye in a sample under test and the resulting absorbance of the sample. The apparatus and related method provide accurate control over the path length, independent of the sample volume used to calibrate the spectrophotometer. Finally, the present invention eliminates meniscus errors associated with vertical beam measurements. While the description of the present invention will be directed to its advantageous use in a vertical beam spectrophotometer, it may also be used to calibrate horizontal beam spectrophotometers as well. These and other features are achieved in the present invention through the arrangement of a calibration plate having one or more sealed calibration cuvettes, each cuvette containing a solution having one or more chromophores of selectable reference concentrations. The present invention provides the operator with the ability to calibrate a vertical beam spectrophotometer at wavelengths that correspond exactly with the solutions to be tested, rather than using the broad spectral response of ND glass. For example, if a specific dye is used as an absorbance indicator in an assay, a set of solutions with increasing concentration of the specific dye may be made and inserted into the cuvettes in the calibration plate. The calibration plate is then used to calibrate the optical response of the vertical beam spectrophotometer over the expected absorbance range of the specific dye. The potential exists for incorporating more than one dye in each cuvette, so long as the multiple dyes do not significantly overlap in their absorbance responses. The present invention provides further advantage in its stability as a standard. Specifically, by sealing a standard in a cuvette retained in the calibration plate, the present invention minimizes changes in the standard caused by its prolonged exposure to air. An expansion zone is maintained within the cuvette to allow for thermal expansion and contraction of the solution therein during any thermal cycling. The expansion zone may be established in a variety of ways, including the means to be described herein. An expansion zone isolator is preferably included in the cuvette to isolate the expansion zone from the portion of the cuvette exposed to the spectrophotometer beam. Options on the form of the isolator will be described herein. The cuvette is oriented in the calibration plate such that it presents to the vertically aligned light beam a fixed path length through the solution. Further, that cuvette orientation displaces any meniscus from the beam path. In effect, the present invention provides a fixed path length, defined by the cross section of the cuvette, to a spectrophotometer, whether a vertical beam type or a horizontal beam type. The calibration plate includes means for retaining one or more cuvettes. Each retained cuvette defines a test section of the plate and may include a unique chromophore solution for calibration. However, it is to be understood that a single test cuvette may be deployed in the calibration plate, and that multiple cuvettes may contain the same chromophore solutions. Each test section of the plate may be further defined by one or more transparent beam ports for the light beam to pass to and through the solution in the retained cuvette. Each port establishes a fixed path length cell based on the cuvette's cross section. The calibration plate optionally includes a test section including an ND glass filter for selectable comparison to that standard. The calibration plate of the present invention includes one or more cuvettes that allow for insertion of solutions of interest. The solutions may be user defined and unique to the user's interests, or standardized solutions available commercially. In the later case, the filled cuvettes could be referenced to a spectrophotometer in the manufacturer's facility in the manner described in the related patent. The solution-filled cuvettes function as optical standards for calibrating the spectrophotometer response, or can be used to establish a relation between a given concentration of a solution and the absorbance exhibited. The solutions retained therein, the sealed arrangement of the cuvette(s), and the arrangement of the cuvette(s) within the calibration plate provide an effective means for spectrophotometer calibration, while avoiding the deficiencies in the vertical beam spectrophotometer calibration techniques in existence. These and other advantages and aspects of the apparatus and method of the present invention will become apparent upon review of the following detailed description, the accompanying drawings, and the appended claims. | 20040130 | 20060613 | 20050804 | 63778.0 | 1 | EVANS, FANNIE L | APPARATUS AND METHOD FOR CALIBRATION OF SPECTROPHOTOMETERS | SMALL | 0 | ACCEPTED | 2,004 |
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10,768,920 | ACCEPTED | Method and system for embedding messages within HTTP | A system for embedding messages within HTTP streams, including a gateway communicator, situated within a network gateway computer that communicates with at least one client computer, for receiving management data intended for the at least one client computer from a management server computer that communicates with the network gateway computer, a gateway data embedder situated within the network gateway computer for inserting non-HTTP management data within an HTTP message, and a client data extractor situated within each of the at least one client computer for extracting non-HTTP management data from within an HTTP message. A method and a computer readable storage medium are also described and claimed. | 1. A system for embedding messages within HTTP streams, comprising: a gateway communicator, situated within a network gateway computer that communicates with at least one client computer, for receiving management data intended for the at least one client computer from a management server computer that communicates with the network gateway computer; a gateway data embedder situated within the network gateway computer for inserting non-HTTP management data within an HTTP message; and a client data extractor situated within each of the at least one client computer for extracting non-HTTP management data from within an HTTP message. 2. The system of claim 1 further comprising: a client data embedder situated within each of the at least one client computer for inserting non-HTTP management data within an HTTP message; and a gateway data extractor situated within the network gateway computer for extracting non-HTTP management data from an HTTP message; and wherein the gateway communicator transmits extracted management data to the management server computer. 3. The system of claim 2 wherein the management data is corporate intranet management data. 4. The system of claim 2 wherein the management data is corporate security management data. 5. A method for embedding messages within HTTP streams, comprising: receiving management data intended for at least one client computer; inserting non-HTTP management data within an HTTP message prior to the HTTP message being received by the at least one client computer; and extracting non-HTTP management data from within an HTTP message subsequent to the HTTP message being received. 6. The method of claim 5 further comprising receiving an HTTP message intended for a management server computer, the HTTP message having non-HTTP management data embedded therewithin. 7. The method of claim 6 wherein the management data is corporate intranet management data. 8. The method of claim 6 wherein the management data is corporate security management data. 9. A computer-readable storage medium storing program code for causing a computer to perform the steps of: receiving management data intended for at least one client computer; inserting non-HTTP management data within an HTTP message; and extracting non-HTTP management data from within an HTTP message. 10. A system for a network gateway computer that communicates with at least one client computer, comprising: a communicator for receiving management data intended for at least one client computer from a management server computer, and for transmitting an HTTP message to the at least one client computer; and a gateway data embedder for inserting non-HTTP management data within an HTTP message. 11. The system of claim 10 wherein the management data is corporate intranet management data. 12. The system of claim 10 wherein the management data is corporate security management data. 13. A system for a client computer that communicates with a network gateway computer, comprising: a communicator for receiving an HTTP message; and a client data extractor for extracting embedded non-HTTP management data from within an HTTP message. 14. The system of claim 13 wherein the management data is corporate intranet management data. 15. The system of claim 13 wherein the management data is corporate security management data. | FIELD OF THE INVENTION The present invention relates to efficient delivery of management data between a network management server and a plurality of client computers. BACKGROUND OF THE INVENTION Network security systems often transmit security management data between a management server and a plurality of client computers over a corporate intranet, in order to protect client computers from mobile code For example, corporate anti virus software regularly sends queries from a server to clients, to ascertain which version of a signature file the clients are using, and sends signature updates to the clients, as necessary; and the clients regularly send query responses, identifying the version of their current signature file, to the server, and send event logs, such as a report about a virus discovered on a client, as necessary, to the server. Similarly, network management applications, such as Open View®, a product of Hewlett Packard Co. of Palo Alto, Calif., and Unicenter®, a product of Computer Associates International, Inc. of Islandia, N.Y., regularly transmit network management data between a server and clients. Management data is typically transmitted back and forth over a network typically using a proprietary non-HTTP protocol, and thus creates additional traffic, above and beyond the HTTP traffic. Such additional traffic increases the number of packets traveling on the network, and the processing required to handle them. SUMMARY OF THE INVENTION The present invention provides a method and system for optimizing bandwidth utilization and request/response handling within a distributed network. As described above, network management and security systems often distribute management data from a server to a plurality of client computers over a corporate intranet. Using the present invention, the management data is embedded within HTTP messages transmitted between a network gateway or proxy, and the same plurality of client computers. The management data is encoded in such a way that it can be readily extracted from the HTTP messages received by the gateway or proxy, and the client computers. Thus the present invention enables management and security systems to “piggy back” on top of regular HTTP traffic that runs back and forth between client web browsers and a corporate gateway or HTTP proxy. In a preferred embodiment of the present invention, HTTP traffic between a corporate gateway or proxy and a plurality of clients is intercepted at a Winsock level, and proprietary management data is embedded therewithin. The present invention also includes a method and system to extract the management data from the HTTP messages, so that (i) the management data can be processed by the client computers and by the gateway or proxy; and (ii) HTTP data forwarded by the gateway or proxy outside the corporation does not include the extra management data. There is thus provided in accordance with a preferred embodiment of the present invention a system for embedding messages within HTTP streams, including a gateway communicator, situated within a network gateway computer that communicates with at least one client computer, for receiving management data intended for the at least one client computer from a management server computer that communicates with the network gateway computer, a gateway data embedder situated within the network gateway computer for inserting non-HTTP management data within an HTTP message, and a client data extractor situated within each of the at least one client computer for extracting non-HTTP management data from within an HTTP message. There is further provided in accordance with a preferred embodiment of the present invention a method for embedding messages within HTTP streams, including receiving management data intended for at least one client computer, inserting non-HTTP management data within an HTTP message prior to the HTTP message being received by the at least one client computer, and extracting non-HTTP management data from within an HTTP message subsequent to the HTTP message being received. There is yet further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving management data intended for at least one client computer, inserting non-HTTP management data within an HTTP message, and extracting non-HTTP management data from within an HTTP message. There is moreover provided in accordance with a preferred embodiment of the present invention a system for a network gateway computer that communicates with at least one client computer, including a communicator for receiving management data intended for at least one client computer from a management server computer, and for transmitting an HTTP message to the at least one client computer, and a gateway data embedder for inserting non-HTTP management data within an HTTP message. There is additionally provided in accordance with a preferred embodiment of the present invention a system for a client computer that communicates with a network gateway computer, including a communicator for receiving an HTTP message, and a client data extractor for extracting embedded non-HTTP management data from within an HTTP message. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood and appreciated from the following detailed description, taken in conjunction with the drawings in which: FIG. 1 is a simplified block diagram of a prior art system for transmitting management data back and forth between a management server computer and a plurality of client computers; FIG. 2 is a simplified block diagram of a system for embedding messages within HTTP streams, in accordance with a preferred embodiment of the present invention; FIG. 3 is a simplified flowchart of a method for transmitting management data within an HTTP message sent by a client, in accordance with a preferred embodiment of the present invention; and FIG. 4 is a simplified flowchart of a method for transmitting management data within an HTTP message sent by a network gateway, in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The present invention provides a method and system for efficient delivery of management data communicated between a network management server and a plurality of client computers within a network such as a corporate intranet. Reference is now made to FIG. 1, which is a simplified block diagram of a prior art system 100 for transmitting management data back and forth between a management server computer and a plurality of client computers. Shown in FIG. 1 are a plurality of client computers 105, 110, 115 and 120, within a corporate intranet, connected to a corporate gateway computer 125 via communication lines 130 and 135. Gateway computer 125 may alternatively be a proxy computer. Gateway computer 125 connects to an internet 140 via a communication line 145. Client computers 105, 110, 115 and 120 typically use web browsers to send requests and responses across the corporate intranet, and across the internet. Also shown in FIG. 1 is a management server 150, connected to clients 105, 110, 115 and 120 via a communication line 155. Management server 150 may be, for example, (i) a network management server, for managing a corporate intranet, such as a server running Open View® software, a product of Hewlett Packard Co. of Palo Alto, Calif., or running Unicenter® software, a product of Computer Associates International, Inc. of Islandia, N.Y.; or (ii) a network security server, for protecting a corporate intranet from unauthorized access and from malicious software. Management server 150 and clients 105, 110, 115 and 120 regularly transmit management data back and forth. Such management data may include, for example, network resource queries and responses, queries and responses to ascertain current versions of anti-virus signature files, and updated signature files. Although communication lines 130, 135, 145 and 155 are illustrated as individual lines, it may be appreciated that they are part of one or more interconnected networks, and that transmission of data between clients 105, 110, 115 and 120, gateway 125, management server 150 and internet 140 operates by generating communication sockets within such networks. Specifically, clients 105, 110, 115 and 120, gateway 125 and management server 150 include TCP/IP and Winsock communication modules 160, for managing communication sockets. Data traffic between gateway 125 and clients 105, 110, 115 and 120 typically includes HTTP requests and responses, between web browsers within the corporate intranet, and web servers distributed over internet 140. A typical HTTP packet 170, as shown in FIG. 1, includes one or more TCP and IP headers, indicated by data block 173, one or more TCP and IP trailers, indicated by data block 175, and a message body with HTTP data, indicated by data block 177. Data traffic between management server 150 and clients 105, 110, 115 and 120 typically is formatted using a proprietary non-HTTP transport protocol. A typical management data packet 180, as shown in FIG. 1, includes one or more TCP and IP headers, indicated by data block 183, one or more TCP and IP trailers, indicated by data block 185, and a message body with management data, indicated by data block 187. Prior art system 100 suffers from a drawback that management server 150 creates additional traffic, above and beyond the HTTP traffic. Such additional traffic increases the number of TCP/IP packets traveling on the network. Moreover, because TCP/IP packets generally include TCP headers and trailers, IP headers and trailers, and other data control overhead, the additional packets on the network include additional overhead as well. Reference is now made to FIG. 2, which is a simplified block diagram of a system 200 for embedding messages within HTTP streams, in accordance with a preferred embodiment of the present invention. For the sake of clarifying the improvement that system 200 offers over prior art system 100, like numerals, in the 100-199 range, are used in both figures for common components, and numerals in the 200-299 range are used for components that are unique to FIG. 2. Shown in FIG. 2 is a similar network architecture, in which client computers 105, 110, 115 and 120 are connected to gateway computer 125 and to a management server computer 150 within a corporate intranet. However, in distinction to FIG. 1, management server 150 sends and receives its management data through gateway 125. Generally, management data is formatted for transmission using a proprietary, non-HTTP protocol. Clients 105, 110, 115 and 120, and gateway 125 include management data embedders 265 and management data extractors 270. Management data embedder 265 embeds management data within HTTP messages, and management extractor extracts the management data from the HTTP messages. Preferably, clients 105, 110, 115 and 120 use their management data extractors 270 to extract management data sent to them by management server 150, which was packaged within HTTP messages received over communication lines 135. Preferably, clients 105, 110, 115 and 120 use their management data embedders 265 to embed management data intended for management server 150 within HTTP messages sent over communication lines 135. Preferably, gateway 125 uses its management data embedder 265 to embed management data received from management server 150 and intended for clients 105, 110, 115 and 120, within HTTP messages sent over communication lines 135. Preferably, gateway 125 uses its management data extractor 270 to extract management data packaged within HTTP messages received over communication lines 135. The extracted management data is forwarded by gateway 125 to management server 150, and the HTTP messages without the management data are forwarded to their indicated destination on internet 140. Preferably, management server 150 sends and receives management data over a communication line 275 between management server 150 and gateway 125, instead of directly over communication lines 135, as in FIG. 1. As shown in FIG. 2, HTTP packets 290 traveling over communication lines 130 and 135 that contain combined HTTP+management data include TCP/IP header data 292, TCP/IP trailer data 294, and a body that includes both HTTP data 296 and management data 298. Thus it may be appreciated that packets 290 of FIG. 2 replace packets 170 and 180 of FIG. 1. Although the same management data goes back and forth between management server 150 and clients 105, 110, 115 and 120, both in prior art system 100 and in system 200 of the present invention, the routing indicated in FIG. 2 has several advantages. In particular, using the present invention: the number of packets sent over the intranet is reduced; overall traffic volume is reduced, since the additional packets sent using system 100 include header, trailer and other control data overhead; and processing for handling TCP/IP requests and responses is reduced. It may be appreciated that management server 150 may also send proprietary non-HTTP data to clients 105, 110, 115 and 120 along communication line 155 (FIG. 1), as necessary. Thus direct communication along line 155 is still available using the present invention, if required. Reference is now made to FIG. 3, which is a simplified flowchart of a method for transmitting management data within an HTTP message sent by a client, in accordance with a preferred embodiment of the present invention. The flowchart shown in FIG. 3 is divided into two columns, the left column indicating steps performed by a client, and the right column indicating steps performed by a network gateway. At step 310 the client prepares an HTTP message for transmission to a web server. At step 320 the client prepares non-HTTP management data for transmission to a management server. Rather than send the HTTP message and non-HTTP management data as separate messages, at step 330 the client embeds the management data within the HTTP message. In one embodiment, the structure for performing step 330 is management data embedder 265 (FIG. 2). At step 340 the client sends the HTTP message, now including the management data embedded therein, to the web server. On its way to the web server, the HTTP message first passes through the gateway, and is received by the gateway at step 350. At step 360 the gateway extracts the non-HTTP management data from within the HTTP message. In one embodiment, the structure for performing step 360 is management data extractor 270 (FIG. 2). The gateway reconstructs the original HTTP message, without the management data. At step 370 the gateway sends the management data to the management server, and at step 380 the gateway sends the HTTP message, without the management data, to the intended web server. Reference is now made to FIG. 4, which is a simplified flowchart of a method for transmitting management data within an HTTP message sent by a network gateway, in accordance with a preferred embodiment of the present invention. The flowchart shown in FIG. 4 is divided into two columns, the left column indicating steps performed by a network gateway, and the right column indicating steps performed by a client. At step 410 the gateway receives non-HTTP management data intended for one or more clients, from a management server. At step 420 the gateway receives an HTFP message from a web server, on its way to a client. At step 430 the gateway embeds the non-HTTP management data within the HTTP message. In one embodiment, the structure for performing step 430 is management data embedder 265 (FIG. 2). At step 440 the gateway forwards the HTTP message, now including the management data, to the intended client. At step 450 the client receives the HTTP message, and at step 460 the client extracts the non-HTTP management data from within the HTTP message. In one embodiment, the structure for performing step 460 is management data extractor 270 (FIG. 2). At step 470 the client processes the management data, as required, and at step 480 the client processes the HTTP message, as required. In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made to the specific exemplary embodiments without departing from the broader spirit and scope of the invention as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. | <SOH> BACKGROUND OF THE INVENTION <EOH>Network security systems often transmit security management data between a management server and a plurality of client computers over a corporate intranet, in order to protect client computers from mobile code For example, corporate anti virus software regularly sends queries from a server to clients, to ascertain which version of a signature file the clients are using, and sends signature updates to the clients, as necessary; and the clients regularly send query responses, identifying the version of their current signature file, to the server, and send event logs, such as a report about a virus discovered on a client, as necessary, to the server. Similarly, network management applications, such as Open View®, a product of Hewlett Packard Co. of Palo Alto, Calif., and Unicenter®, a product of Computer Associates International, Inc. of Islandia, N.Y., regularly transmit network management data between a server and clients. Management data is typically transmitted back and forth over a network typically using a proprietary non-HTTP protocol, and thus creates additional traffic, above and beyond the HTTP traffic. Such additional traffic increases the number of packets traveling on the network, and the processing required to handle them. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a method and system for optimizing bandwidth utilization and request/response handling within a distributed network. As described above, network management and security systems often distribute management data from a server to a plurality of client computers over a corporate intranet. Using the present invention, the management data is embedded within HTTP messages transmitted between a network gateway or proxy, and the same plurality of client computers. The management data is encoded in such a way that it can be readily extracted from the HTTP messages received by the gateway or proxy, and the client computers. Thus the present invention enables management and security systems to “piggy back” on top of regular HTTP traffic that runs back and forth between client web browsers and a corporate gateway or HTTP proxy. In a preferred embodiment of the present invention, HTTP traffic between a corporate gateway or proxy and a plurality of clients is intercepted at a Winsock level, and proprietary management data is embedded therewithin. The present invention also includes a method and system to extract the management data from the HTTP messages, so that (i) the management data can be processed by the client computers and by the gateway or proxy; and (ii) HTTP data forwarded by the gateway or proxy outside the corporation does not include the extra management data. There is thus provided in accordance with a preferred embodiment of the present invention a system for embedding messages within HTTP streams, including a gateway communicator, situated within a network gateway computer that communicates with at least one client computer, for receiving management data intended for the at least one client computer from a management server computer that communicates with the network gateway computer, a gateway data embedder situated within the network gateway computer for inserting non-HTTP management data within an HTTP message, and a client data extractor situated within each of the at least one client computer for extracting non-HTTP management data from within an HTTP message. There is further provided in accordance with a preferred embodiment of the present invention a method for embedding messages within HTTP streams, including receiving management data intended for at least one client computer, inserting non-HTTP management data within an HTTP message prior to the HTTP message being received by the at least one client computer, and extracting non-HTTP management data from within an HTTP message subsequent to the HTTP message being received. There is yet further provided in accordance with a preferred embodiment of the present invention a computer-readable storage medium storing program code for causing a computer to perform the steps of receiving management data intended for at least one client computer, inserting non-HTTP management data within an HTTP message, and extracting non-HTTP management data from within an HTTP message. There is moreover provided in accordance with a preferred embodiment of the present invention a system for a network gateway computer that communicates with at least one client computer, including a communicator for receiving management data intended for at least one client computer from a management server computer, and for transmitting an HTTP message to the at least one client computer, and a gateway data embedder for inserting non-HTTP management data within an HTTP message. There is additionally provided in accordance with a preferred embodiment of the present invention a system for a client computer that communicates with a network gateway computer, including a communicator for receiving an HTTP message, and a client data extractor for extracting embedded non-HTTP management data from within an HTTP message. | 20040130 | 20100713 | 20050804 | 64487.0 | 2 | HAMZA, FARUK | EMBEDDING MANAGEMENT DATA WITHIN HTTP MESSAGES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,769,042 | ACCEPTED | Portable traffic information system | The present invention provides a device, system, and method for a portable handheld device for displaying information. An embodiment of the invention provides a portable handheld device for displaying information, including traffic information. The portable device includes a wireless receiver arranged for receiving an information-data packet having at least one payload element, a translation table arranged for decoding a payload element, and a microcontroller including a memory and a processor, and which is operable to decode the at least one payload element. The device also includes an information viewing screen that includes an incorporated traffic map having road-display segments corresponding to selected roads and the visual display, the visual display having a plurality of individually controllable display elements corresponding to the road-display segments, each element corresponding to a road-display segment and being arranged to display a plurality of visual properties each representing a different traffic condition. | 1-29. Cancelled 30. A mobile information display device, the device comprising: a wireless receiver configured to receive an information-data packet having at least one payload element; a correlation parameter configured for decoding a payload element; a microcontroller including a memory and a processor, and which is operable to decode the at least one payload element in response to the correlation parameter; an information viewing screen that includes an incorporated traffic map having road-display segments corresponding to selected roads and a visual display; and the visual display having a plurality of individually controllable display elements corresponding to the road-display segments and being arranged to display a plurality of visual properties each representing a different traffic condition. 31. The device of claim 30, wherein the correlation parameter includes a translation table. 32. The device of claim 30, wherein the correlation parameter is a traffic-information translation table. 33. The device of claim 30, wherein the information viewing screen further includes an incorporated displayable icon, and a controllable visual display element corresponding to the icon. 34. The device of claim 33, wherein the controllable visual display element includes a liquid-crystal display. 35. The device of claim 33, wherein an unlit visual display element corresponds to the icon not being displayed. 36. The device of claim 33, wherein a lit visual display element corresponds to the icon being displayed. 37. The device of claim 30, wherein a display element includes a liquid-crystal display. 38. The device of claim 37, wherein the liquid-crystal display is a fixed-segment liquid crystal display. 39. The device of claim 30, wherein an unlit element indicates a first traffic condition, a slow flash indicates a second traffic condition, a fast flash indicates a third traffic condition, and a solid display indicates a fourth traffic condition. 40. A method of displaying information in a mobile wireless receiver that includes a display having an incorporated traffic map, the method comprising the steps of: receiving an information-data packet having at least one payload element that includes traffic information; decoding a payload element; displaying the traffic map having a plurality of fixed road-display segments corresponding to selected roads, and a plurality of individually controllable display elements corresponding to the road-display segments, each element corresponding to a road-display segment and being arranged to display a plurality of visual properties each representing a different traffic condition; and displaying one visual property of a display element in response to the decoded payload element. 41. The method of claim 40, wherein the decoding step further includes decoding traffic information in response to a correlation parameter. 42. The method of claim 41, wherein the correlation parameter includes a translation table. 43. The method of claim 40, wherein the traffic map includes a displayable icon and a display element corresponding to the icon. 44. A method of providing information to a plurality of mobile wireless devices each having a display, the method comprising the steps of: gathering data on selected information, including traffic information for road segments; conditioning the gathered data; encoding at least a portion of the gathered data; creating an information-data packet having at least one payload element that includes traffic information; and causing the information-data packet to be transmitted to the plurality of mobile wireless devices. 45. A method of providing information to a plurality of mobile wireless devices, the method comprising the steps of: gathering data on selected information, including traffic information for a plurality of road segments; conditioning the gathered data; encoding at least a portion of the gathered data; creating an information-data packet having at least one payload element that includes traffic information; and causing the information-data packet to be transmitted to the plurality of mobile wireless devices, each having a viewing screen that includes an incorporated traffic map having road-display segments and a visual display having a plurality of individually controllable display elements corresponding to the road-display segments. 46. The method of claim 45, wherein the conditioning step further includes the step of reducing the gathered data for a predetermined number of road segments into one road-display segment 47. The method of claim 45, wherein each viewing screen of the plurality of mobile devices further includes an incorporated displayable icon, and a controllable visual display element corresponding to the icon. 48. The method of claim 45, wherein the data is gathered over the Internet. 49. A computer-implemented system configured for providing information to a plurality of mobile wireless devices, the system comprising: a computer having at least one processor and data storage; an Internet connection to the World Wide Web; a plurality of processes spawned by the at least one processor, the processes including: gathering data on selected information from the World Wide Web, including traffic information for reported road segments; conditioning the traffic information by reducing data for a predetermined number of reported road segments into one road-display segment; encoding at least a portion of the gathered data; creating an information-data packet having at least one payload element that includes traffic information; and causing the information-data packet to be transmitted to the plurality of mobile wireless devices. | SUMMARY The present invention provides a device, system, and method for providing a portable handheld device for displaying information. An embodiment of the invention provides a portable handheld device for displaying information, including traffic information. The portable device includes a wireless receiver arranged for receiving an information-data packet having at least one payload element, a translation table arranged for decoding a payload element, and a microcontroller including a memory and a processor, and which is operable to decode the at least one payload element. The device also includes an information viewing screen that includes an incorporated traffic map having road-display segments corresponding to selected roads and the visual display, the visual display having a plurality of individually controllable display elements corresponding to the road-display segments, each element corresponding to a road-display segment and being arranged to display a plurality of visual properties each representing a different traffic condition. The microcontroller may be further operable to decode at least one payload element in response to the grouping of bits within a payload element. The microcontroller may be further operable to decode at least one payload element in response to the grouping of bits within a payload element and the translation table. The information-data packet may include a plurality of payload elements arranged in a predetermined order. The microcontroller may be further operable to decode at least one payload element in response to the grouping of the payload elements. One payload element may include traffic information, and the translation table is a traffic-information translation table. The translation table may be arranged to decode traffic information encoded into one pair of bits for each road-display segment. A display element may include a liquid-crystal display (LCD), which may be a fixed-segment LCD. An unlit element may indicate no traffic congestion, a slow flash may indicate minor traffic congestion, a fast flash may indicate bad congestion, and a solid display may indicate severe traffic congestion. The receiver may be further arranged to receive the data packet from a pager service. Another embodiment of the invention provides a method of displaying information in a portable handheld wireless receiver having a display. The method includes the steps of receiving an information-data packet having at least one payload element that includes traffic information, decoding a payload element, and displaying a traffic map having a plurality of fixed-road-display segments corresponding to selected roads, and further displaying a plurality of individually controllable display elements corresponding to the road-display segments, each element corresponding to a road-display segment and being arranged to display a plurality of visual properties each representing a different traffic condition. The decoding step may further include decoding traffic information in response to a traffic-information translation table. At least one payload element may have a predetermined size. At least one payload element may have a predetermined size, and wherein the decoding step may further include decoding in response to a grouping of bits within the payload element. At least one payload element may have a predetermined size and include traffic information encoded into one pair of bits per road-display segment, and the decoding step may further include decoding in response to a position of the pair of bits within the payload element. The data packet may include a plurality of payload elements in a predetermined order, and the decoding step may further include decoding in response to the order of the payload element. The receiving step may include further receiving the data packet from a pager service. A further embodiment of the invention provides a method of providing information to a plurality of portable handheld wireless devices each having a display. The method including the steps of gathering data on selected information, including traffic information for reported road segments, conditioning the traffic information by reducing data for a predetermined number of reported road segments into one road-display segment, and encoding at least a portion of the gathered data. The method also includes creating an information-data packet having at least one payload element that includes traffic information, and causing the information-data packet to be transmitted to the plurality of wireless devices. The conditioning step may further include the step of reducing four-reported road segments into one road-display segment. The traffic condition for a single-display road segment may be represented by a plurality of displayable levels. The encoding step may further include the step of encoding the conditioned traffic information in response to a traffic-information translation table. The encoding step may further include encoding the conditioned traffic information into a pair of bits for each road-display segment in response to a traffic-information translation table, the pair of bits representing four different levels of traffic congestion, and positioning pairs of bits may be in a predetermined order within a traffic-payload element. The each byte in the traffic payload element may contain traffic information for four road-display segments. The order of a pair of bits in each byte may determine the road-display segment for which the traffic information is being provided. The creating step may further include, within a payload element, grouping bits in a predetermined sequential order and assigning an information feature to each group of bits. The creating step may further include grouping bits of a traffic-information payload element into adjacent pairs, each pair of bits representing traffic information for one road-display segment, and the position of the pair of bits in the payload element determining which road-display segment is represented. The causing step further including causing the data packet to be transmitted over a pager system. In a yet further embodiment, a computer-implemented system configured for providing information to a plurality of portable handheld wireless devices is provided. The system including a computer having at least one processor and data storage, and an Internet connection to the World Wide Web. The system further including a plurality of processes spawned by the at least one processor, the processes including gathering data on selected information from the World Wide Web, including traffic information for reported road segments, conditioning the traffic information by reducing data for a predetermined number of reported road segments into one road-display segment, encoding at least a portion of the gathered data, creating an information-data packet having at least one payload element that includes traffic information, and causing the information-data packet to be transmitted to the plurality of wireless devices. BRIEF DESCRIPTION OF THE DRAWINGS The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood by making reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like referenced numerals identify like elements, and wherein: FIG. 1 is a block diagram of the key components of the system embodying the present invention. FIG. 2 is a flow diagram of the process used to convert information received from the Internet into a format readable by the field unit, according to an embodiment of the invention. FIG. 3 is a more detailed flow diagram of a process of FIG. 2, which illustrates a detailed example of the conversion of Internet traffic data into field-unit format data, according to an embodiment of the invention. FIG. 4 is a description of a general data packet that is received by the field unit, according to an embodiment of the invention. FIG. 5 is a specific example of a data packet described in FIG. 4, according to an embodiment of the invention. FIG. 6 is a functional block diagram of the field unit of the present invention, according to an embodiment of the invention. FIG. 7 is an example of the LCD segments of a field unit, according to an embodiment of the invention. FIG. 8 is an example of a printed map that sits behind the LCD display to give boundaries to unlit LCD segments, according to an embodiment of the invention. DETAILED DESCRIPTION In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings, which form a part hereof. The detailed description and the drawings illustrate specific exemplary embodiments by which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is understood that other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the present invention. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. The meaning of “a”, “an”, and “the” include plural references. The meaning of “in” includes “in” and “on.” Additionally, a reference to the singular includes a reference to the plural unless otherwise stated or inconsistent with the disclosure herein. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of an electronic computing device, such as a computer system or similar device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. The present invention relates to a system that retrieves data from the Internet, including traffic and other miscellaneous datum, and sends it to portable field units, which are portable handheld wireless receivers or devices arranged for displaying information. FIG. 1 illustrates a system embodying the invention which generally includes Internet resources 22, a data manager 10 embodying particular aspects of the invention, a standard one-way pager service 24, a radio tower 26 associated with pager service 24, a standard telephone 28, and field units 190 embodying particular aspects of the invention, and according to an embodiment of the invention. The Internet resources 22 provide the data to be sent to the field units 190. Internet resources are servers coupled to the Internet 20. They include a sports server 12, a weather server 14, a stock market server 16, and a traffic-information server 18. The Internet services provided are conventional and well known in the art. The data manager 10 is coupled to the Internet and retrieves information from the Internet resources 22. The data manager 10 then compresses the retrieved data and sends the data via the Internet 20 to the paging-service provider 24. The paging service 24 sends this information to a radio tower 26, which subsequently broadcasts data to the field units 190. As is known in the prior art, the pager service may acquire sports, market, weather and traffic information and transmit the data to text-display pagers. In accordance with the present invention, the data manager 10 gets sports, market, weather and traffic information and sends it to the paging service. The pager service 24 also provides a telephone interface 28 which allows individuals to enter a numeric page which is subsequently sent to the radio tower 26 and sent to field units of a particular address. The field unit 190 receives data transmitted from radio tower 26 via an antenna 170. The antenna is coupled to a microcontroller 174 which decodes the received data and manages peripherals. A display 172, which may be a fixed-segment (LCD), is coupled to the microcontroller and displays the received information. Traffic information may be constantly displayed on the display while other data is selectable via keys 176 which facilitate navigation and selection of provided information. FIG. 2 illustrates the operation of the data manager 10 that gathers and compresses data from the Internet and sends it to the paging service, according to an embodiment of the invention. Once the data manager is started at step 40, it connects to the Internet and receives data from the Internet resources 22 in step 42. The data manager 10 checks if the weather information has been updated since the last retrieval of Internet information at step 44. If it is updated, the weather data is encoded in step 46. The encoded weather data may contain five days of weather information including high and low temperatures and data-encoding information for iconic display of either: sun, sun/cloud, sun/cloud/rain, or rain. The next step 48 determines whether the sports information has been updated since the last retrieval of Internet information. If it is updated, the data is encoded in step 50. The encoded sports scores may include several local team's scores. The next step 52 determines whether the stock information has been updated since the last retrieval of Internet information. If it is updated, the data is encoded in step 54. The stock-index values may include values for the NASDAQ, DJIA and S&P 500. The next step 56 determines whether the traffic information has been updated since the last retrieval of Internet information. If it is updated, the data is encoded in step 58. The next step 60 determines whether any data has been encoded or updated since the last data transmission. If it has, then a data packet is created in step 62 and sent to the paging service via the Internet in step 64. Next the system delays processing in step 66 for a fixed amount of time and then starts over by repeating step 42 for receiving data from the Internet. FIG. 3 illustrates a more detailed process for the traffic data encoding step 58 of FIG. 2, according to an embodiment of the invention. Traffic information from the Internet typically includes traffic congestion for numerous segments of the highway system. The encoding process of step 62 may reduce the number of traffic segments sent to the field unit 190 to achieve greater usability by employing a method of averaging to reduce the number of segments necessary to easily communicate traffic conditions. Encoded traffic information may be tightly compacted into two bits per highway segment. This encoding signifies four different levels of congestion to the pager, and efficiently compacts four segments into one byte. Each geography where this system can be used has unique challenges that might require different encoding algorithms. FIG. 3 provides an example. In the example of FIG. 3, four data points received from the traffic-information service 18 are conditioned to represent one LCD segment. Furthermore, the data received from the traffic information service 18 ranges in value between 1 and 100 and is converted by this process to values between and including 0 and 3. The process starts in step 70 and sets a variable called CURRENT_SEGMENT to 0 in step 72. This variable keeps track of what segment is currently being encoded. The next step 74 increments CURRENT_SEGMENT, sets INDEX to 0 which indicates which one of the four raw-data points is being accessed and sets UNIT_DATA[CURRENT_SEGMENT] to 0 to initialize a variable to be used for generating output. Process 76 gets data from the data manager's 10 stored traffic data 78. Process 76 then adds the current data for the current index and segment to the variable UNIT_DATA[CURRENT_SEGMENT]. After the addition, RECIEVED_DATA is incremented. This process is repeated four times per segment as process 80 dictates. After exiting process 80, UNIT_DATA contains the summation of four segments which are being combined to represent one LCD segment. Process 82 divides the current UNIT_DATA value by 400 and rounds the result. This value then ranges inclusively between 0 and 3. Process 84 causes the foregoing process to be repeated eogjt times for the eogjt LCD segments. Upon exiting, process 86 returns the eight LCD segments values in the array UNIT_DATA. FIG. 4 illustrates an example of a data packet created through the data-encoding process described with respect to FIG. 3 and which is to be sent to the field unit via radio tower 26, according to an embodiment of the invention. The data packet contains an initial byte 90 that identifies this packet. The example uses the ASCII character ‘*’ for the start byte 90. The packet contents byte 92 identifies the data contained in the packet. This byte is used so that only the newly updated information categories are updated. Each enabled bit of byte 92 indicates the data to be included in the packet 91, as defined in a packet-lookup table 110. Bitwise ORing the values of 110 associated with the included data results in the value of byte 92. For example, if the value of byte 92 is 0x01, only the traffic data is contained in the packet 91. A value of 0x81 indicates both weather and traffic. Traffic data 94 may be a fixed number of bytes used to encode traffic data. The format for the traffic data bytes may follow the format shown at 112. Byte 112 contains data which encodes four LCD segments with four discrete values. Encoding traffic data is achieved by pairing adjacent bits starting with bits 0 and 1 and ending with the bit pair 6 and 7. Market data 96 includes and encodes the Dow Jones Industrial Average 114, the S&P 500 index 116 and the NASDAQ index 188. Each of the market indicators is encoded in two bytes which supports values up to 65,535 for each market value via binary representation. The sports data packets 98, 100, 102, 104, and 106 are associated with unique sports teams. Each sports data packet contains the home-team score and the competitor score encoded in individual bytes resulting in scores up to 255 for each team. The weather data 108 contains weather-forecast data. The two bytes shown as item 120 contain five sets of two bits to encode iconic weather symbols representing the weather for each of five days. With two bits per icon, one of four icons can be encoded. For example, these bits could encode: a sun icon, a cloudy icon, a rainy icon, and a partly sunny icon. The forecasted data 122, 124, 126, 128 and 130 contains high and low temperatures for each forecasted day. Each day's high and low temperatures may be encoded using sign-magnitude representation allowing temperature values between −127 and 127. FIG. 5 illustrates an example data packet in the format specified in data packet 91, according to an embodiment of the invention. The start byte 140 is the ASCII ‘*’ which is 0x2A. The contents packet 142 contains 0x41 which, using table 110 to decode it, contains traffic and Sports 5 data. Eight traffic LCD segments which are contained in the two bytes of traffic data 144 are encoded. The sports information is contained in byte 146. The traffic translation table 148 shows what each of the pairs of traffic encode/decode data translates to in terms of how the display segment acts (off, slow flash, fast flash, or solid on). Each segment is shown in LCD screen 150 and their display characteristics are defined in table 148 as one of four possible LCD states. For example, the first two bits of the first byte of traffic data 144 correspond to segment 1 and are of the value binary 00. The decode table 148 indicates that binary 00 indicates the LCD segment is off and the symbolized for descriptive purposes as ‘O’. Segment 1 152 has an ‘O’ adjacent to it to indicate that the segment is off. The remaining bits follow this pattern. The sports data is simply binary represented and therefore the home score 146 of 0x10 is equivalent to decimal 16 and the competitor score of 0x0A is equivalent to decimal 10. FIG. 6 is a functional block diagram of an implementation of the portable field unit 190 (also referred to herein as “portable handheld wireless device”), according to an embodiment of the invention. The field unit 190 is a portable handheld wireless receiver for displaying information, including traffic information. The components of the unit 190 may be housed in a hand-holdable plastic enclosure dimensioned for single-handed use with a visible LCD display 172. The antenna 170 receives the transmitted data from the radio tower 26 and sends the received signal to the RF interface 180 for signal conditioning including analog-signal-to-digital-signal conversion. The digital signal provided by the RF interface 180 is coupled to the microcontroller 174. The microcontroller 174 may include a microprocessor 182, Random Access Memory (RAM) 184, Read-Only Memory (ROM) 186 and a LCD driver 188. A real-time clock 178 is coupled to the microcontroller 174 to provide time functionality. Also, the microcontroller is coupled to a user interface 176 which includes four keys. The interface 176 facilitates navigation through the selection of provided information. The display 172 may be a fixed-segment LCD display providing a static map and an area for variable numeric information and icons. FIG. 7 illustrates an example information-viewing screen, hereafter referred to as a traffic-pager LCD screen 216, containing enough LCD segments to visually represent all the data contained in packet 91, according to an embodiment of the invention. The traffic-pager LCD screen 216 includes a screen portion 200 that further includes a local traffic map having road-display segments corresponding to selected local roads of the region in which the portable field unit will be used. The screen portion 200 illustrates segments used to display traffic congestion. In an embodiment, the field unit 190 is localized with the local traffic map incorporated into the screen portion 200. For example, a field unit 190 localized for the greater Seattle region may use a local traffic map incorporated into the screen portion 200 similar to that illustrated FIG. 7. A field unit 190 localized for another region, such as Los Angeles, Tokyo, or London, for example, would have a different local traffic map incorporated into its screen portion 200. The local traffic map may be incorporated into the traffic-pager LCD screen 216 in any manner known in the art, including printing the local traffic map to lie underneath the LCD and be viewable. A local highway system is presented as many fixed-line segments that are individually controlled to convey traffic information. For example, in an embodiment, a line segment not lit indicates no traffic problem, a slow flash indicates minor traffic congestion, a fast flash indicates bad congestion and a solid display indicates severe traffic congestion. Likewise, a colored LCD may be used to communicate varying traffic conditions. All data, other than that displayed in portion 200, is selected by the keys 176. Screen portion 204 contains constantly lit menu headers that indicate what content is being displayed by marks in screen portion 202. If, for example, time is selected, the time will appear in the numeric screen portion 210. By selecting date, the date will appear in portion 210. By selecting market, the select keys enable one item of 208 possible items to be displayed with the corresponding data. By selecting sports, the select keys enable one item of 212 possible items to be displayed with the corresponding data. By selecting weather, the select keys enable one item of 206 possible items to be displayed with the corresponding data in portion 210 and icons in portion 214. By selecting page, the select keys may be used to scroll through received pages displayed in portion 210 and allow for deletion of current-page display. This method of displaying traffic data is unique in that LCD segments are being used to provide at-a-glance information of a large geographic area at a cost savings. FIG. 8 shows a printed map 220 that may lie behind the LCD to illustrate the road boundaries of the LCD screen and other geographic markers including cities and lakes. The map serves the purpose of defining roadways when an LCD segment is not lit. The invention thus provides a system for retrieving data from Internet sources and transmitting the data to customized handheld devices for providing road-traffic information discernable with at-a-glance ease. The information may be made available anywhere within the geographical coverage of the system. The preceding description has been presented only to illustrate and describe the invention. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described invention was chosen to explain the principles of this invention. The preceding description is intended to enable those skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to this particular use contemplated. | <SOH> SUMMARY <EOH>The present invention provides a device, system, and method for providing a portable handheld device for displaying information. An embodiment of the invention provides a portable handheld device for displaying information, including traffic information. The portable device includes a wireless receiver arranged for receiving an information-data packet having at least one payload element, a translation table arranged for decoding a payload element, and a microcontroller including a memory and a processor, and which is operable to decode the at least one payload element. The device also includes an information viewing screen that includes an incorporated traffic map having road-display segments corresponding to selected roads and the visual display, the visual display having a plurality of individually controllable display elements corresponding to the road-display segments, each element corresponding to a road-display segment and being arranged to display a plurality of visual properties each representing a different traffic condition. The microcontroller may be further operable to decode at least one payload element in response to the grouping of bits within a payload element. The microcontroller may be further operable to decode at least one payload element in response to the grouping of bits within a payload element and the translation table. The information-data packet may include a plurality of payload elements arranged in a predetermined order. The microcontroller may be further operable to decode at least one payload element in response to the grouping of the payload elements. One payload element may include traffic information, and the translation table is a traffic-information translation table. The translation table may be arranged to decode traffic information encoded into one pair of bits for each road-display segment. A display element may include a liquid-crystal display (LCD), which may be a fixed-segment LCD. An unlit element may indicate no traffic congestion, a slow flash may indicate minor traffic congestion, a fast flash may indicate bad congestion, and a solid display may indicate severe traffic congestion. The receiver may be further arranged to receive the data packet from a pager service. Another embodiment of the invention provides a method of displaying information in a portable handheld wireless receiver having a display. The method includes the steps of receiving an information-data packet having at least one payload element that includes traffic information, decoding a payload element, and displaying a traffic map having a plurality of fixed-road-display segments corresponding to selected roads, and further displaying a plurality of individually controllable display elements corresponding to the road-display segments, each element corresponding to a road-display segment and being arranged to display a plurality of visual properties each representing a different traffic condition. The decoding step may further include decoding traffic information in response to a traffic-information translation table. At least one payload element may have a predetermined size. At least one payload element may have a predetermined size, and wherein the decoding step may further include decoding in response to a grouping of bits within the payload element. At least one payload element may have a predetermined size and include traffic information encoded into one pair of bits per road-display segment, and the decoding step may further include decoding in response to a position of the pair of bits within the payload element. The data packet may include a plurality of payload elements in a predetermined order, and the decoding step may further include decoding in response to the order of the payload element. The receiving step may include further receiving the data packet from a pager service. A further embodiment of the invention provides a method of providing information to a plurality of portable handheld wireless devices each having a display. The method including the steps of gathering data on selected information, including traffic information for reported road segments, conditioning the traffic information by reducing data for a predetermined number of reported road segments into one road-display segment, and encoding at least a portion of the gathered data. The method also includes creating an information-data packet having at least one payload element that includes traffic information, and causing the information-data packet to be transmitted to the plurality of wireless devices. The conditioning step may further include the step of reducing four-reported road segments into one road-display segment. The traffic condition for a single-display road segment may be represented by a plurality of displayable levels. The encoding step may further include the step of encoding the conditioned traffic information in response to a traffic-information translation table. The encoding step may further include encoding the conditioned traffic information into a pair of bits for each road-display segment in response to a traffic-information translation table, the pair of bits representing four different levels of traffic congestion, and positioning pairs of bits may be in a predetermined order within a traffic-payload element. The each byte in the traffic payload element may contain traffic information for four road-display segments. The order of a pair of bits in each byte may determine the road-display segment for which the traffic information is being provided. The creating step may further include, within a payload element, grouping bits in a predetermined sequential order and assigning an information feature to each group of bits. The creating step may further include grouping bits of a traffic-information payload element into adjacent pairs, each pair of bits representing traffic information for one road-display segment, and the position of the pair of bits in the payload element determining which road-display segment is represented. The causing step further including causing the data packet to be transmitted over a pager system. In a yet further embodiment, a computer-implemented system configured for providing information to a plurality of portable handheld wireless devices is provided. The system including a computer having at least one processor and data storage, and an Internet connection to the World Wide Web. The system further including a plurality of processes spawned by the at least one processor, the processes including gathering data on selected information from the World Wide Web, including traffic information for reported road segments, conditioning the traffic information by reducing data for a predetermined number of reported road segments into one road-display segment, encoding at least a portion of the gathered data, creating an information-data packet having at least one payload element that includes traffic information, and causing the information-data packet to be transmitted to the plurality of wireless devices. | 20040130 | 20060627 | 20050210 | 95321.0 | 1 | ARTHUR JEANGLAUD, GERTRUDE | MOBILE TRAFFIC INFORMATION SYSTEM | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,769,086 | ACCEPTED | Gaming device having a multiple coordinate award distributor including award percentages | A gaming device includes an award distributor having a plurality of sections having first and second coordinates, a symbol group and a plurality of modifier groups including the sections, a plurality of awards associated with the sections in the symbol group and a plurality of award percentages associated with the sections in the modifier groups, an illumination device associated with the sections, a section indicator associated with the award distributor and a processor in communication with the award distributor. The gaming device determines the first coordinate of one of the modifier groups and then spins the award wheel to determine the second coordinate of one of the sections in the indicated modifier group, which indicates the section. The section indicator also indicates a section including an award in the symbol group. The indicated award is multiplied by the indicated award percentage to provide an activation award to the player. | 1. A gaming device comprising: a game operable upon a wager; an award distributor including a plurality of sections, each of said sections defined by one of a plurality first coordinates and one of a plurality of second coordinates; a plurality of groups of said sections including a symbol group and a plurality of modifier groups; a plurality of symbols associated with the sections in the symbol group; a plurality of modifiers associated with the sections in the modifier groups; at least one section indicator associated with the award distributor; and a processor operable to determine one of the first coordinates of one of the sections in the modifier group, independently determine one of the second coordinates of one of the sections in said modifier group, cause the section indicator to indicate the section in the modifier group associated with the determined first and second coordinates, cause the section indicator to indicate one of the sections in the symbol group and provide an activation award to a player based on the symbol and the modifier associated with the indicated sections. 2. The gaming device of claim 1, which includes a probability of being determined associated with each of the first and second coordinates. 3. The gaming device of claim 2, wherein a plurality of the probabilities are the same. 4. The gaming device of claim 2, wherein all of the probabilities are the same. 5. The gaming device of claim 1, which includes a probability of being indicated by the section indicator associated with each of the sections, wherein the processor determines the first and second coordinates based on said probabilities. 6. The gaming device of claim 1, wherein the symbols are award symbols. 7. The gaming device of claim 6, which includes a plurality of awards associated with the award symbols. 8. The gaming device of claim 6, which includes a plurality of awards associated with the award symbols and a plurality of award percentages associated with the modifiers, wherein the activation award equals the award multiplied by the award percentage associated with the indicated sections in the symbol group and the indicated modifier group. 9. The gaming device of claim 7, wherein the awards include at least one of the awards selected from the group consisting of: a value, a modifier, a multiplier, a free activation, a free spin, a free game and a prize. 10. The gaming device of claim 7, wherein the awards include at least one relatively large award and a plurality of relatively small awards. 11. The gaming device of claim 10, which includes a probability of being selected by the processor associated with the awards, wherein the probability associated with the relatively large award is less than the probability associated with at least one of the relatively small awards. 12. The gaming device of claim 10, which includes a probability of being selected by the processor associated with the awards, wherein the probability associated with the relatively large award is less than the probabilities associated with a plurality of the relatively small awards. 13. The gaming device of claim 10, which includes a probability of being selected by the processor associated with the awards, wherein the probability associated with the relatively large award is less than the probabilities associated with all of the relatively small awards. 14. The gaming device of claim 1, wherein the modifiers include a plurality of award percentages. 15. The gaming device of claim 14, wherein the sections in the modifier groups include a plurality of relatively low award percentages and a plurality of relatively high award percentages. 16. The gaming device of claim 14, wherein each of the modifier groups include the same award percentages. 17. The gaming device of claim 14, wherein at least one of the modifier groups includes different award percentages. 18. The gaming device of claim 14, wherein a plurality of the modifier groups include different award percentages. 19. The gaming device of claim 14, wherein all of the modifier groups include different award percentages. 20. The gaming device of claim 19, wherein the modifier groups include higher award percentages in each successive modifier group. 21. The gaming device of claim 19, wherein the sections in the modifier groups include lower award percentages in each successive modifier group. 22. The gaming device of claim 1, which includes a plurality of potential total awards, whereby said processor picks one of the symbols and one of the modifiers and repeatedly causes the section indicator to indicate sections on the award distributor until the activation awards based on the symbols and the modifiers on the indicated sections equal the total award. 23. The gaming device of claim 22, wherein the total awards are associated with probabilities of being picked by the processor. 24. The gaming device of claim 1, wherein the section indicator includes at least one illumination device operable to illuminates the sections in the modifier groups on the award distributor. 25. The gaming device of claim 1, wherein the section indicator includes at least one illumination device associated with each of the sections in the modifier groups, wherein the illumination device is operable to illuminate one of the sections in said groups of sections on the award distributor. 26. The gaming device of claim 1, wherein the section indicator includes a plurality of illumination devices which are operable to simultaneously illuminate a plurality of the sections in the modifier groups on the award distributor. 27. The gaming device of claim 1, wherein the section indicator includes a plurality of illumination devices which are operable to alternately illuminate a plurality of the sections in the modifier groups on the award distributor. 28. The gaming device of claim 1, wherein the section indicator includes at least one illumination device which is operable to illuminate the sections in the symbol group on the award distributor. 29. The gaming device of claim 1, wherein a plurality of the sections in the modifier groups include a terminator symbol. 30. The gaming device of claim 29, which includes a probability of being indicated by the section indicator associated with each of the sections in the modifier groups, wherein the probabilities associated with the sections including the terminator symbols are greater than the probabilities associated with a plurality of the other sections in the modifier groups. 31. The gaming device of claim 29, which includes a probability of being indicated by the section indicator associated with each of the sections in the modifier groups, wherein the probabilities associated with the sections including the terminator symbols are greater than the probabilities associated with all of the other sections in the modifier groups. 32. The gaming device of claim 1, wherein a plurality of the sections in the symbol group include a terminator symbol. 33. The gaming device of claim 1, wherein the award distributor includes an award wheel. 34. The gaming device of Clam 33, which includes a spin initiator controlled by the processor for enabling the player to cause the processor to initiate each movement of one of said wheel and said section indicator. 35. The gaming device of claim 1, wherein the award distributor includes a plurality of wheels. 36. The gaming device of claim 35, wherein the symbol group and plurality of modifier groups are on different wheels. 37. The gaming device of claim 35, wherein the symbol group and each of the modifier groups are on different wheels. 38. The gaming device of claim 1, which includes a bonus award provided to the player when at least one section in each of the modifier groups is indicated by the section indicator. 39. The gaming device of claim 1, wherein the modifiers include award percentages, and wherein at least two of the award percentages in each of the modifier groups are different. 40. The gaming device of claim 1, which includes a selector, which enables a player to pick one of the sections, a plurality of the sections or all of the sections on the award distributor. 41. The gaming device of claim 1, wherein the section or sections indicated by the section indicator in at least one spin remain indicated for a designated number of spins. 42. The gaming device of claim 41, wherein the designated number of spins is randomly determined. 43. The gaming device of claim 41, wherein the designated number of spins is pre-determined. 44. The gaming device of claim 41, wherein the designated number of spins is determined based on a wager made by the player. 45. The gaming device of claim 1, which includes a plurality of section indicators associated with the award distributor. 46. The gaming device of claim 45, which includes a plurality of activatable section indicators associated with the award distributor, wherein only the activated section indicators indicate sections on the award distributor. 47. The gaming device of claim 46, wherein the section indicators are randomly activated. 48. The gaming device of claim 46, wherein the section indicators are activated based on a wager made by a player. 49. The gaming device of claim 46, wherein the section indicators are activated based on a number of activations of the award distributor. 50. The gaming device of claim 1, which includes designated sections to be indicated in a designated number of activations of the award distributor. 51. The gaming device of claim 1, which includes designated sections to be indicated in a designated time period. 52. A gaming device comprising: a plurality of award wheels, each of said award wheels including a plurality of sections, each of said sections having a first coordinate and a second coordinate; a plurality of groups of said sections including a symbol group and a plurality of modifier groups, wherein the symbol group is included on one of the award wheels and the plurality of modifier groups are displayed by different award wheels; a plurality of awards associated with the sections in the symbol group; a plurality of award percentages associated with the sections in the modifier groups; at least one section indicator associated with the award wheels; and a processor operable to determine the first coordinate of one of the sections in the modifier groups, independently determine the second coordinate of one of the sections in said modifier group, spin at least one of the wheels, cause the section indicator to indicate the section in the modifier group associated with the determined first and second coordinates, cause the section indicator to indicate one of the sections in the symbol group and provide an activation award to a player based on the award and the award percentage associated with the indicated sections. 53. The gaming device of claim 52, wherein the awards include at least one of the awards selected from the group consisting of: a value, a modifier, a multiplier, a free activation, a free spin, a free game and a prize. 54. The gaming device of claim 52, wherein the awards include at least one relatively large award and a plurality of relatively small awards. 55. The gaming device of claim 54, which includes a probability of being selected by the processor associated with the awards, wherein the probability associated with the relatively large award is less than the probability associated with at least one of the relatively small awards. 56. The gaming device of claim 54, which includes a probability of being selected by the processor associated with the awards, wherein the probability associated with the relatively large award is less than the probabilities associated with a plurality of the relatively small awards. 57. The gaming device of claim 54, which includes a probability of being selected by the processor associated with the awards, wherein the probability associated with the relatively large award is less than the probabilities associated with all of the relatively small awards. 58. The gaming device of claim 52, wherein the sections in the modifier groups include a plurality of relatively low award percentages and a plurality of relatively high award percentages. 59. The gaming device of claim 52, wherein each of the modifier groups include the same award percentages. 60. The gaming device of claim 40, wherein at least one of the modifier groups includes different award percentages. 61. The gaming device of claim 52, wherein a plurality of the modifier groups include different award percentages. 62. The gaming device of claim 52, wherein all of the modifier groups include different award percentages. 63. The gaming device of claim 52, wherein the modifier groups include higher award percentages in each successive modifier group on the wheels. 64. The gaming device of claim 52, wherein the modifier groups include lower award percentages in each successive modifier group. 65. The gaming device of claim 52, wherein the symbol group and each of the modifier groups are on different wheels. 66. The gaming device of claim 52, which includes a bonus award provided to the player when at least one section in each of the modifier groups is indicated by the section indicator. 67. A gaming device comprising: an award distributor including a plurality of sections, each of said sections having one of a plurality of first coordinates and one of a plurality of second coordinates; a plurality of groups of said sections including an award group and a plurality of symbol groups; a plurality of awards associated with the sections in the award group, said award including at least one prize; a plurality of symbols associated with the sections in the symbol groups, said symbols including a plurality of award percentages and at least one letter associated with the prize; at least one section indicator associated with the award distributor; and a processor operable to determine the first coordinate of one of the sections in the symbol group, independently determine the second coordinate of one of the sections in said symbol group, cause the section indicator to indicate the section in the symbol group associated with the determined first and second coordinates, cause the section indicator to indicate one of the sections in the award group and provide an activation award to the player based on the award and the symbol associated with the indicated sections. 68. The gaming device of claim 67, wherein the prize is provided to the player when all of the letters associated with the prize are indicated by the section indicator. 69. The gaming device of ° claim 67, wherein the prize is at least one of the prizes selected from the group consisting of: a physical prize, a monetary prize, a free spin, a free game, a multiplier and a trip. 70. The gaming device of claim 67, wherein said symbols include a plurality of letters associated with a prize, wherein each letter is included in a different symbol group. 71. The gaming device of claim 70, wherein the prize is provided to the player when the letters in each of the symbol groups associated with the prize are indicated by the section indicator. 72. A method for operating a gaming device, said method comprising: the steps of: (a) randomly determining a first coordinate of a group of sections from a plurality of groups of sections including award percentages on an award distributor; (b) randomly determining a second coordinate of one of the sections on the award distributor; (c) indicating the award percentage of the section associated with the determined first and second coordinates; (d) indicating an award associated with a group of sections including a plurality of awards; and (e) providing an activation award to the player based on the indicated award and the indicated award percentage. 73. The method of claim 72, which includes illuminating the indicated sections on the award distributor. 74. The method of claim 72, which includes associating a probability of being indicated with each of the sections on the award wheel, wherein the first and second coordinates of the indicated section are based on the probabilities. 75. The method of claim 72, which includes alternately illuminating the groups of sections including the award percentages on the award distributor. 76. The method of claim 63, which includes enabling a player to select one of the illuminated groups of sections on the award distributor. 77. The method of claim 72, which includes providing a bonus award to the player when at least one section in each of the groups of sections are indicated on the award distributor. 78. The gaming device of claim 72, which includes enabling a player to select one of the sections, a plurality of the sections or all of the sections on the award distributor using a selector. 79. The gaming device of claim 72, which includes indicating at least one section for a designated number of spins. 80. The gaming device of claim 79, wherein the designated number of spins is randomly determined. 81. The gaming device of claim 79 wherein the designated number of spins is pre-determined. 82. The gaming device of claim 72, wherein the designated number of spins is determined based on a wager made by the player. 83. The gaming device of claim 72, which includes indicating a plurality of sections using a plurality of section indicators associated with the award distributor. 84. The gaming device of claim 72, which includes indicating a plurality of sections using a plurality of activatable section indicators associated with the award distributor. 85. The gaming device of claim 84, wherein the section indicators are randomly activated. 86. The gaming device of claim 84, wherein the section indicators are activated based on a wager made by a player. 87. The gaming device of claim 84, wherein the section indicators are activated based on a number of activations of the award distributor. 88. The gaming device of claim 72, which includes the step of indicating at least one designated section on the award distributor in a designated number of activations of the award distributor. 89. The gaming device of claim 72, which includes the step of indicating at least one designated section on the award distributor in a designated time period 90. The method of claim 72, which includes operating the gaming device through a data network. 91. The method of claim 90, wherein the data network is an internet. 92. A method for operating a gaming device, said method comprising: (a) randomly determining a first coordinate of a group of sections from a plurality of groups of sections including at a at least one letter on an award distributor; (b) randomly determining a second coordinate of one of the sections on the award distributor; (c) indicating the letter of the section associated with the determined first and second coordinates; (d) repeating steps (a) to (c) until at least one letter is indicated in each of the groups of sections; (e) indicating a prize associated with the indicated letters; and (f) providing the prize to the player. 93. The method of claim 92, which includes alternately illuminating the groups of sections including the award percentages on the award distributor. 94. The gaming device of claim 92, wherein the prize is at least one of the prizes selected from the group consisting of: a physical prize, a monetary prize, a free spin, a free game, a multiplier and a trip. 95. The method of claim 92, which includes operating the gaming device through a data network. 96. The method of claim 95, wherein the data network is an internet. | PRIORITY CLAIM This application is a continuation-in-part of and claims the benefit of U.S. patent application Ser. No. 10/630,529, filed Jul. 30, 2003 which is incorporated herein in its entirety. COPYRIGHT NOTICE A portion of the disclosure of this patent document contains or may contain material which is subject to copyright protection. The copyright owner has no objection to the photocopy reproduction by anyone of the patent document or the patent disclosure in exactly the form it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. BACKGROUND OF THE INVENTION Gaming device manufacturers strive to make gaming devices that provide as much enjoyment and excitement as possible. Providing a secondary or bonus game in which a player has an opportunity to win potentially large awards or credits in addition to the awards associated with the primary or base game of the gaming device is one way to enhance player enjoyment and excitement. Gaming devices having bonus games generally employ a triggering event that occurs during the base game operation of the gaming device. The triggering event temporarily stalls or halts the base game play and enables a player to enter a second, different game, which is the bonus game. The player plays the bonus game, likely receives an award, and returns to the base game. One known bonus game is in the WHEEL OF FORTUNE® gaming device manufactured by the assignee of this application. In this game, a multi-colored award wheel is attached to a cabinet of the gaming device. The award wheel is divided into several sections. Each section includes an award that ranges in value from twenty to one thousand. In this game, a player plays a base game that includes spinning reels and a central payline. When the wheel symbol is positioned along the central payline on the third reel, the player enters the bonus game. In the bonus game, the player obtains one opportunity or spin of the award wheel. The player spins the award wheel by pressing a button on the gaming device. Once the award wheel starts spinning, the player waits until it stops. An indicator located at the top of the award wheel points to a section of the wheel. The player receives the award on that section for the bonus game. After the player receives that award, the bonus game ends and the player can resume playing the base game. Another known game is described in U.S. Pat. No. 6,059,658 to Mangano et al. This patent relates to a spinning award wheel game. The game includes a display having five concentrically arranged wheels. Each wheel has indicia designated with an Ace, King, Queen, Jack, Ten and a wild symbol along the outer edge of the circles. Once a player enters the game, the player initiates the spinning of the wheels. Each wheel rotates independently of the other wheels. The object of the game is to align winning combinations of indicia, which in this game are winning hands in poker. A indicator points to a sequence of five indicia formed from each of the five rotating wheels. If the sequence equals a winning combination, the player receives an award. To increase player enjoyment and excitement, therefore, it is desirable to provide new bonus games having award wheels that provide larger awards to players with minimal risk. SUMMARY OF THE INVENTION The present invention provides a gaming device and in particular a bonus game of a gaming device that enables players to accumulate awards by obtaining sections on an award distributor such as an award wheel based on the coordinates of the sections. In one embodiment, the award wheel includes several annular areas or groups that are each divided into a plurality of sections. The sections are each defined by first and second coordinates on the award wheel and include award symbols that are associated with awards. The coordinates define the location of each section on the award wheel. Initially, the gaming device alternately illuminates each annular area, which defines the first coordinate of the groups of sections in the annular areas. In one embodiment, the gaming device picks one of the annular areas. In another embodiment, the gaming device enables the player to pick one of the annular areas where the awards associated with the annular areas are approximately equal. Once the first coordinate is defined by selecting one of the annular areas on the award wheel, the gaming device or player activates or spins the award wheel. When the wheel stops spinning, a section indicator indicates a second coordinate which together with the first coordinate, defines the determined section in the annular area. The player receives the award associated with the section that is defined by the indicated first and second coordinates. In one embodiment, the player continues to play the bonus game until the player is out of activations or spins of the award wheel. In one preferred embodiment, the award wheel is divided into several groups or annular areas where each of the annular areas is further divided into several sections. The first coordinate of a group of sections is represented by the radial distance from the center of the award wheel to the annular area. The second coordinate of one of the sections in the group is defined by the angular location of a section along the annular area. Each section includes a symbol such as an award symbol. A plurality of awards are associated with the award symbols. In one embodiment, the awards associated with the sections in the innermost annular areas of the award wheel are substantially lower awards than the awards associated with the sections located in the outermost annular areas of the wheel. Each annular area is alternately highlighted or illuminated at the start of the bonus game by an illumination device. The annular areas alternately light up, one at a time, until only one area is randomly selected and remains illuminated. In one embodiment, the gaming device (i.e., the processor) determines the indicated annular area. In another embodiment, the gaming device enables the player to pick the annular area as described above. Next, the gaming device or player activates or spins the award wheel. Once the wheel stops spinning, the section indicator indicates one of the sections in the indicated or highlighted annular area. The player receives the award associated with the indicated section. The player continues to play the bonus game until the player has no spins remaining in the game. In another embodiment, the award wheel first is spun to indicate a pie-shaped area of the wheel. Each pie-shaped section is further divided into individual sections by the annular areas on the wheels. Then, the sections in the indicated pie-shaped area are alternately illuminated until one section is randomly selected and remains illuminated. The player receives the award associated with that selected section. In a further embodiment, an annular area is illuminated and defines the first coordinate of a group of sections. Then the indicator spins about the perimeter of the award wheel to define the second coordinate of one of the sections in the illuminated annular area. When the indicator stops, the indicated first and second coordinates define the indicated section on the award wheel. The gaming devices provides the player with the award associated with the indicated section defined by the determined first and second coordinates. In an alternative embodiment of the present invention the sections on the award wheel include a plurality of awards and a plurality of award percentages. Specifically, the award wheel includes a plurality of sections wherein the sections are arranged in a plurality of groups. The groups of sections include a symbol group, which includes the sections in the outermost annular area and a plurality of modifier groups, which include the sections in inner annular areas. In one embodiment, a plurality of awards, such as award values or credits, are associated with the sections in the symbol group. The awards may include values, multipliers, modifiers, monetary prizes, non-monetary prizes, physical prizes or any suitable type of award. It should be appreciated that any of the annular areas or groups on the award wheel may include sections having one or more awards. Additionally, a plurality of award portions or award percentages are associated with the sections in the modifier groups. In one embodiment, the modifier groups include award percentages of 100%, 75%, 50% and 25% associated with each of the sections in these groups. The award percentages may be any suitable award percentages desired by the game implementor. In one embodiment, the award percentages associated with the sections in each of the modifier groups are the same. In another embodiment, the award percentages associated with the sections in each of the modifier groups are different. It should be appreciated that at least one of the award percentages, a plurality of the award percentages or all of the award percentages associated with the sections within each of the groups may be different. Additionally, the award percentages associated with the sections may be different from group to group. In one embodiment, the award percentages associated with the sections in the groups increase from the innermost annular area to the outermost annular area. In another embodiment, the award percentages decrease from the innermost modifier group to outermost modifier group. Furthermore, the award percentages may be represented as fractions, decimals or any other suitable type of award portion, fraction or percentage. In an operational embodiment, the gaming device indicates an award percentage and an award in each activation or spin of the award wheel. The indicated award percentage is multiplied by the or applied to an indicated award in the symbol group to provide an activation or spin award to the player for that activation or spin. For example, when an indicated section includes an award percentage of 75% (0.75), the gaming device provides the player with 75% of the award associated with the indicated section in the symbol group. In other words, the gaming device multiplies the indicated award by 0.75 to provide an activation award to the player for that activation or spin. In one embodiment, each of the modifier groups are included on the same wheel and rotate in the same direction. In another embodiment, at least one of the modifier groups is included on a separate wheel from the other annular areas. In this embodiment, the wheels may rotate in the same direction or in different directions. In a further embodiment, each of the modifier groups are included on separate wheels. The wheels may rotate in the same direction, at least one may rotate in different directions from the other wheels or a plurality of the wheels may rotate in a different direction. In a further embodiment, the award wheel may also remain stationary and the section indicator may rotate about the perimeter of the award wheel in a clockwise or counterclockwise direction. The gaming device also includes an additional bonus award such as a big bonus award. In one embodiment, the big bonus award is indicated in the middle of the award wheel includes a masked or hidden award provided to the player by the gaming device when all of the award percentages associated with a particular award are indicated in the game (i.e., in the number of spins of the wheel provided to the player). The big bonus award may be an award value, a modifier, a multiplier, free spins, free games or any other suitable award. The big bonus award is provided to the player in the game or in a subsequent game (i.e, free spins) or added to the player's total award in the game (i.e, an award value or credits). In another embodiment, the gaming device enables a player to pick or select an annular area or pie-shaped area or segment of the wheel prior to playing the game or initiating the spins of the wheel in the game. It should be appreciated that the gaming device may enable the player to pick one, a plurality or the annular areas and/or pie-shaped segments or areas of the wheel in a game. It should also be appreciated that the gaming device may enable the player to pick the annular area or areas or pie-shaped section or sections prior to playing the game, prior to one spin in the game or prior to a plurality of the spins in the game. In one embodiment, the gaming device enables the player to pick one of the annular areas or pie-shaped sections by pressing or touching the corresponding annular area or pie-shaped section on a touch screen display device or by pressing a button or similar input device which corresponds to the annular area or pie-shaped section on the wheel. In a further embodiment, the gaming device of the present invention is employed in a progressive type game where a player accumulates indicated sections on the wheel in a plurality of games. In this embodiment, the indicated sections remain highlighted or illuminated for a designated number of games. The designated number of games may be predetermined, randomly determined or determined in any suitable manner. In one aspect of this embodiment, the awards are associated with a probability of being indicated such that the relatively small awards include greater probabilities than the relatively large awards. In this aspect, a significant portion of the relatively small awards are indicated before the relatively large awards are indicated on the wheel. Once the designated number of games are reached, the gaming device resets the award wheel so that none of the sections are indicated (i.e., highlighted) on the wheel. It should be appreciated that the gaming device may reset the award wheel so that none, one, a plurality or all of the sections are highlighted on the wheel. In another embodiment, a plurality of section indicators are associated with the wheel such that multiple sections are indicated on the wheel in a spin. This enables a player to obtain multiple awards associated with the multiple sections indicated on the wheel in a single spin. In one embodiment, the section indicators associated with the wheel are activated such that only the activated section indicators indicate sections on the wheel. The section indicators may be activated by particular sections on the wheel or based on the number of spins provided to the player in the game. The number of section indicators may also be based on a wager made by the player in the base game or in a bonus game. In a further embodiment the multiple section indicators are moveable such that the section indicators move about the wheel at the beginning of a game and are stopped or locked in place by the gaming device or the player. The section indicators may move at the beginning of the game, during the game, after one spin or a plurality of the spins of the wheel or at any suitable point in a game. The moveable indicators enable the player to interact with the game and therefore provides additional excitement and enjoyment of the game. In another embodiment, a time dimension is associated with the present invention to offer enhanced play and awards in the game. In one aspect of this embodiment, a larger award or a plurality of awards are provided to the player when a designated number of sections are indicated in a designated number of spins of the wheel. For example, the gaming device provides a larger award or a bonus award to a player when the player indicates all of the sections associated with one of the awards in a particular number of spins of the award wheel. The gaming device decreases the award for each additional spin or spins needed by the player to indicate those sections. In another aspect of this embodiment, the gaming device only provides a bonus award when the player indicates a specific section or sections in a designated number of spins. If the sections or sections are indicated after the designated number of spins are reached, the gaming device does not provide a bonus or extra award to the player. It should be appreciated that the designated section or sections may be predetermined, randomly determined or determined according to any suitable determination method. In a further aspect of this embodiment, a time period is associated with the game such that the gaming device or the player spins the wheel during the time period and indicates sections and accumulates awards associated with those sections during the time period. When the time period expires, the game ends and the player receives the total accumulative award for the game. The present invention may be employed in a primary or base game or, a secondary or bonus game or any suitable type of game such as poker, blackjack, roulette, dice, slots, multi-line slots or any other suitable wagering game. It is therefore an advantage of the present invention to provide a gaming device having a multi-coordinate wheel with an alternating bonus award where awards and award percentages are associated with multi-coordinate locations on the award wheel. Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like numerals refer to like parts, elements, components, steps and processes. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a front perspective view of one embodiment of the gaming device of the present invention which includes a mechanical multi-coordinate award wheel. FIG. 1B is a front perspective view of another embodiment of the gaming device of the present invention which includes a multi-coordinate award wheel in a video format. FIG. 2 is a schematic block diagram of the electronic configuration of one embodiment of the gaming device of the present invention. FIG. 3 is an enlarged elevation view of a display device illustrating one embodiment of the present invention. FIGS. 4A, 4B, 4C 4D, 4E and 4F are enlarged elevation views of a display device of the present invention illustrating three spins of the multi-coordinate award wheel in the bonus game. FIG. 5 is an enlarged elevation view of another embodiment of the present invention where the section indicator moves about the perimeter of the multi-coordinate award wheel. FIG. 6 is an enlarged elevation view of a further embodiment of the present invention where the multi-coordinate award wheel includes a terminator. FIG. 7 is an enlarged elevation view of a further embodiment of the present invention where the multi-coordinate award wheel is stationary and the sections alternately illuminate to provide an award to the player. FIG. 8 is an enlarged elevation view of a further embodiment of the present invention where the sections are arranged in a square configuration. FIG. 9 is an enlarged elevation view of an alternative embodiment of the present invention where the sections of the wheel include awards and percentages of those awards. FIGS. 10A, 10B, 10C, 10D, 10E, 10F and 10G are enlarged elevation views of an example of the alternative embodiment of FIG. 9. FIG. 11 is an enlarged elevation view of another alternative embodiment of the present invention where the sections includes multipliers and percentages of those multipliers. FIG. 12 is an enlarged elevation view of a further alternative embodiment of the present invention where the sections include awards, percentages of those awards, and letters which form a prize or prizes. FIG. 13 is an enlarged elevation view of another alternative embodiment of the present invention where the sections of the wheel include awards and different award percentages. DETAILED DESCRIPTION OF THE INVENTION Gaming Device and Electronics Referring now to the drawings, two embodiments of the gaming device of the present invention are illustrated in FIGS. 1A and 1B as gaming device 10a and gaming device 10b, respectively. Gaming device 10a and/or gaming device 10b are generally referred to herein as gaming device 10. Gaming device 10 is preferably a slot machine having the controls, displays and features of a conventional slot machine. It is constructed so that a player can operate it while standing or sifting, and gaming device 10 is preferably mounted on a console. However, it should be appreciated that gaming device 10 can be constructed as a pub-style table-top game (not shown) which a player can operate preferably while sifting. Furthermore, gaming device 10 can be constructed with varying cabinet and display designs, as illustrated by the designs shown in FIGS. 1A and 1B. Gaming device 10 can also be implemented as a program code stored in a detachable cartridge for operating a hand-held video game device. Also, gaming device 10 can be implemented as a program code stored on a disk or other memory device which a player can use in a desktop or laptop personal computer or other computerized platform. Gaming device 10 can incorporate any primary game such as slot, black jack, poker or keno, any of the bonus triggering events and any of the bonus round games. The symbols and indicia used on and in gaming device 10 may be in mechanical, electrical, electronic or video form. As illustrated in FIGS. 1A and 1B, gaming device 10 includes a coin slot 12 and bill acceptor 14 where the player inserts money, coins or tokens. The player can place coins in the coin slot 12 or paper money or ticket vouchers in the bill acceptor 14. Other devices could be used for accepting payment such as readers or validators for credit cards or debit cards. When a player inserts money in gaming device 10, a number of credits corresponding to the amount deposited is shown in a credit display 16. After depositing the appropriate amount of money, a player can begin the game by pulling arm 18 or pushing play button 20. Play button 20 can be any play activator used by the player which starts any game or sequence of events in the gaming device. As shown in FIGS. 1A and 1B, gaming device 10 also includes a bet display 22 and a bet one button 24. The player places a bet by pushing the bet one button 24. The player can increase the bet by one credit each time the player pushes the bet one button 24. When the player pushes the bet one button 24, the number of credits shown in the credit display 16 decreases by one, and the number of credits shown in the bet display 22 increases by one. A player may cash out and thereby receive a number of coins corresponding to the number of remaining credits by pushing a cash out button 26. When the player cashes out, the player receives the coins in a coin payout tray 28. The gaming device 10 may employ other payout mechanisms such as credit slips redeemable by a cashier or electronically recordable cards which keep track of the player's credits. Gaming device 10 also includes one or more display devices. The embodiment shown in FIG. 1A includes a central display device 30 and a mechanical multi-coordinate award wheel 100 that physically spins in front of a player. The award wheel is divided into a plurality of annular areas 102 that are further divided into sections 104 where each section is indicated by a section indicator 108. The alternative embodiment shown in FIG. 1B includes a central display device 30 as well as an upper display device 32. The upper display device 32 displays the multi-coordinate award wheel 100 of the present invention in a video format. Gaming device 10 in one embodiment preferably displays a plurality of reels 34 such preferably three to five reels 34 in mechanical or video form, on one or more of the display devices. A display device can be any viewing surface such as glass, a video monitor or screen, a liquid crystal display or any other display mechanism. If the reels 34 are in video form, the display device for the video reels 34 is preferably a video monitor. Each reel 34 displays a plurality of indicia such as bells, hearts, fruits, numbers, letters, bars or other images which preferably correspond to a theme associated with the gaming device 10. Furthermore, gaming device 10 preferably includes speakers 36 for making sounds or playing music. As illustrated in FIG. 2, the general electronic configuration of gaming device 10 preferably includes: a processor 38; a memory device 40 for storing program code or other data; a central display device 30; an upper display device 32; a sound card 42; a plurality of speakers 36; one or more input devices 44; and an optional mechanical multi-coordinate award wheel 100. The processor 38 is preferably a microprocessor or microcontroller-based platform which is capable of displaying images, symbols and other indicia such as images of people, characters, places, things and faces of cards. The memory device 40 can include random access memory (RAM) 46 for storing event data or other data generated or used during a particular game. The memory device 40 can also include read only memory (ROM) 48 for storing program code which controls the gaming device 10 so that it plays a particular game in accordance with applicable game rules and pay tables. As illustrated in FIG. 2, the player preferably uses the input devices 44, such as pull arm 18, play button 20, the bet one button 24 and the cash out button 26 to input signals into gaming device 10. In certain instances it is preferable to use a touch screen 50 and an associated touch screen controller 52 instead of a conventional video monitor display device. Touch screen 50 and touch screen controller 52 are connected to a video controller 54 and processor 38. A player can make decisions and input signals into the gaming device 10 by touching touch screen 50 at the appropriate places. As further illustrated in FIG. 2, the processor 38 can be connected to coin slot 12 or bill acceptor 14. The processor 38 can be programmed to require a player to deposit a certain amount of money in order to start the game. It should be appreciated that although a processor 38 and memory device 40 are preferable implementations of the present invention, the present invention can also be implemented using one or more application-specific integrated circuits (ASIC's) or other hard-wired devices, or using mechanical devices (collectively or alternatively referred to herein as a “processor”). Furthermore, although the processor 38 and memory device 40 preferably reside on each gaming device 10 unit, it is possible to provide some or all of their functions at a central location such as a network server for communication to a playing station such as over a local area network (LAN), wide area network (WAN), Internet connection, microwave link, and the like. The processor 38 and memory device 40 is generally referred to herein as the “computer” or “controller.” With reference to FIGS. 1A, 1B and 2, to operate the gaming device 10 in one embodiment the player must insert the appropriate amount of money or tokens at coin slot 12 or bill acceptor 14 and then pull the arm 18 or push the play button 20. The reels 34 will then begin to spin. Eventually, the reels 34 will come to a stop. As long as the player has credits remaining, the player can spin the reels 34 again. Depending upon where the reels 34 stop, the player may or may not win additional credits. In addition to winning credits in this manner, gaming device 10 also gives players the opportunity to win credits in a bonus round. This type of gaming device 10 will include a program which will automatically begin a bonus round when the player has achieved a qualifying condition in the game. This qualifying condition can be a particular arrangement of indicia on a display device. The gaming device 10 preferably uses a video-based central display device 30 to enable the player to play the bonus round. Preferably, the qualifying condition is a predetermined combination of indicia appearing on one or more of a plurality of the reels 34. As illustrated in the five reel slot game shown in FIGS. 1A and 1B, the qualifying condition could be the number seven appearing on three adjacent reels 34 along a payline 56. It should be appreciated that the present invention can include one or more paylines, such as payline 56, wherein the paylines can be horizontal, diagonal or any combination thereof. Bonus Game Referring to FIG. 3, the gaming device 10 includes an award distributor such as a multi-coordinate award wheel 100. In one embodiment, the award wheel 100 is displayed on a video display device such as display device 32 in FIG. 1B. In another embodiment, the award wheel is a mechanical wheel that is physically attached to the gaming device. The award wheel 100 is divided into multiple annular areas 102 where any suitable number of annular areas may be employed by the game implementor. Each annular area 102 is divided into a plurality of sections 104. An award 106 or award symbol is associated with each section 104. In one embodiment, a bonus number of credits is associated with each award symbol. However, it should be appreciated that an award does not have to be associated with each section and that a multiplier, zero award, negative award or other type of modifier may be associated with one or more awards or award symbols on the award wheel. In operation, the multi-coordinate award wheel alternately illuminates the annular areas 102a to 102c. In one embodiment, the gaming device randomly stops on one annular area 102. In another embodiment, a player presses a button or similar input to select an annular area. Once a annular area is determined or selected, the award wheel spins or rotates in a clockwise direction as shown by arrow 110 to indicate a section 104. It should be appreciated that the award wheel can also spin in a counter-clockwise direction if desired. It should also be appreciated that the award wheel and sections thereof may be different shapes and sizes. A section indicator 0.108 is positioned adjacent to the outer edge of the award wheel 100. The indicator 108 indicates or points to one of the sections 104 of the award wheel. In FIG. 3, the section indicator 104 is an arrow-shaped component that is positioned along the outer edge of the award wheel 100. It should be appreciated that the section indicator may also include an illumination device that lights up or highlights a section 104 similar to how the annular sections 102 are highlighted. An illumination device may be associated with each section or with all of the sections. It should also be appreciated that the award wheel may be stationary and the indicator may move around the perimeter of the wheel. Alternatively, both the award wheel and the indicator may move at different rates, or in different directions or at different rates in different directions. The gaming device preferably includes a spin remaining display 112 and a total award display 114. The spin remaining display 112 indicates the number of spins that are remaining in a game. The total award display 114 indicates the value of the bonus awards that the player has accumulated during the bonus game. When the player runs out of spins, the bonus award identified in the total award display 114 is transferred to the player's credit display in a conventional manner. Referring now to FIGS. 4A through 4F, an example of one embodiment of the present invention is illustrated where the gaming device provides a player with three spins to start the bonus game. In this example, the multi-coordinate award wheel 100 has three annular areas 102a, 102b, 102c, and several sections 104 that include awards 106. Referring to FIG. 4A, the gaming device displays several sections 104 on an award wheel 100, where each section has a coordinate location on the award wheel 100. In this example, the coordinate location of each section is defined by a radial coordinate and an angular coordinate. The radial coordinate defines a sections' radial distance from the center of the award wheel or the annular area 102 that contains the section. The angular coordinate defines the location of the section along the perimeter of the award wheel. It should be appreciated that the coordinates of a section may be predefined or randomly determined by the processor. It should also be appreciated that the coordinates may be any coordinates defined by the game implementor. At the start of the bonus game, the gaming device alternately illuminates the annular areas 102a to 102c. The areas illuminate one at a time where area 102a illuminates first, followed by area 102b and 102c. The gaming device repeats this sequence until a radial coordinate or annular area 102 is determined. It should be appreciated that the areas 102 may illuminate in any order or sequence desired by the game implementor. The gaming device stops alternately illuminating the areas after determining the radial coordinate of a section. In another embodiment, a player input determines the radial coordinate. After the radial coordinate is identified or indicated, the gaming device spins the award wheel 100 to determine the angular coordinate of the award section. It should be appreciated that the player may physically spin the award wheel 100 to determine the angular coordinate of the award section. The gaming device spins the award wheel 100 in a clockwise direction as shown by arrow 110. After the award wheel 100 stops spinning, the symbol indicator 108 indicates a section 104, which is defined by the radial coordinate and the angular coordinate of the section. The gaming device provides an award 106 associated with the indicated section 104. The award is transferred to the total award display 114 and the gaming device or player spins the award wheel 100 again if the player has picks remaining in the game as indicated by pick display 112. In FIG. 4A, the gaming device alternately illuminates the annular areas 102, and stops on annular area 102c or the innermost annular area of the multi-coordinate award wheel 100. Referring to FIG. 4B, the gaming device spins the award wheel in a clockwise direction to determine the angular coordinate of a section included in the annular area 102c. The section indicator 108 indicates section 116 in annular area 102c. An award of five is associated with section 116 and this award is transferred to the total award display as indicated by display 114. The player has two spins remaining in the bonus game. Referring now to FIG. 4C, the gaming device alternately illuminates the annular areas 102a, 102b and 102c again. A radial coordinate or annular area 102 is determined by the gaming device, which is annular area 102a. Annular area 102a remains illuminated while the gaming device spins the award wheel 100. In FIG. 4D, the award wheel stops spinning and the section indicator 108 indicates a section in the annular area 102a. Section 108 is indicated by the indicator and the player receives an award of eighty associated with that section. The award, eighty, is transferred and added to the award indicated by the total award display 114 to give the player a new total award of eighty-five. The player has one spin remaining in the bonus game as indicated by pick display 112. Referring now to FIG. 4E, the gaming device alternately illuminates the annular areas 102 until selecting area 102c. Annular area 102c remains illuminated and the gaming device spins the award wheel 100. In FIG. 4F, once the award wheel stops, the section indicator 108 indicates section 120. An award of ten associated with section 120 is transferred and added to the total award displayed in the total award display 114. The new total award equals ninety-five as indicated by the total award display 114. The player does not have any spins remaining as indicated by spin display 112 and therefore, the bonus game ends. Referring now to FIG. 5, another embodiment of the present invention is illustrated where the multi-coordinate award wheel is stationary and the section indicator 108 moves in a clockwise direction along the perimeter of the award wheel. In this embodiment, the section indicator 108 may move in a clockwise or counter clockwise direction to indicate a section 104. Referring to FIG. 6, another embodiment of the present invention includes one or more terminators 122, where the terminator is represented by the letter “X.” If a player obtains a section associated with a terminator, the bonus game ends regardless of how many spins remain in the game. In this embodiment, the player attempts to obtain as many awards as possible before obtaining a terminator or running out of spins. It should be appreciated that a section including a terminator may be associated with a probability such that the coordinates of that section are more likely to be selected by the gaming device than the coordinates of a section associated with an award. Because there are several different sections 104 including a plurality of awards 106 and one terminator 122, the coordinates are preferably associated with probabilities or weighted such that one coordinate is more likely to be indicated by the processor or indicator than another coordinate. In one embodiment, the coordinates are equally weighted or associated with equal probabilities. For example, if an award wheel has twenty-one sections, there are forty-two coordinates associated with those sections. A player, therefore, has a {fraction (1/42)} or approximately 2.38% chance of obtaining any one of the coordinates. Therefore in this embodiment, a player's chances of obtaining the coordinates associated with a particular award are equal to their chances of obtaining the coordinates of the terminator. In another embodiment, the probabilities change after each spin of the award wheel. Coordinates on the award wheel start a bonus game having predetermined probabilities and then the probabilities change after each spin by a player. For example, assume that at the beginning of a bonus game the player has a 2.38% chance of obtaining any coordinate on an award wheel having twenty-one sections. After the player's first spin, the player receives an award. Now the processor alters the probabilities so that the player has a 5% chance of obtaining each coordinate associated with the terminator and a 2.25% chance of obtaining a coordinate associated with any other section on the wheel. Thereafter, the probabilities continue to change after each subsequent spin by the player. It should appreciated that the probability of obtaining the coordinates associated with the terminator may decrease and the probabilities of obtaining the coordinates associated with the awards may increase after a spin, or the awards and terminator may alternately increase and decrease after each spin or change according to whatever probability scheme is desired by the game implementor. It should also be appreciated that the coordinate probabilities may change after the first spin only and remain the same the rest of the bonus game or change after any number of spins desired. In another embodiment, the coordinate probabilities change after a predetermined number of spins of the award wheel. In this embodiment, the implementor sets the probabilities to change after a certain number of spins so that a coordinate having a terminator is more likely or a coordinate associated with a section having a large award is less likely the further the player goes into a bonus game. By adjusting the coordinate probabilities in this manner, the game implementor limits the award amounts that the gaming device pays to players. It also limits the likelihood that a player will obtain the one substantially large award on a spin of the award wheel. For example, assume that an award wheel has twenty sections and a player starts the bonus game with a 2.5% probability of obtaining each coordinate on the wheel. Before the fourth spin of the award wheel, the coordinate probabilities are programmed to change so that there is a 10% chance of obtaining each coordinate associated with the terminator and approximately a 2.11% chance of obtaining each coordinate associated with a section. Now the player is more likely to obtain a terminator with each subsequent spin than any single award associated with a section. Similarly, a bonus game could be programmed to decrease the probability of obtaining coordinates associated with a large award section after a certain number of spins. Therefore, a player still has the possibility of obtaining the large award, but the probability is less. For example, an award wheel having twenty-one sections, including one terminator and one large award section, starts a bonus game where a player has an equal probability of approximately 2.38% of obtaining each coordinate on the award wheel. The gaming device is programmed to decrease the probability of obtaining each coordinate of the large award section after five spins to 0.25%. Therefore after five successful spins of the award wheel, the probability of obtaining each coordinate of the large award section decreases to 0.25% and the probabilities of obtaining any one of the other coordinates associated with the other sections increases to 2.49%. In a further embodiment, total awards or award payouts in a bonus game are associated with probabilities. In this embodiment, the processor of the gaming device is programmed so that relatively larger awards are less likely than relatively smaller awards, or vice versa, in a bonus game. Therefore the game implementor controls the award amounts that are paid out by the gaming device without affecting the player's excitement and enjoyment of playing the game. For example, a processor is programmed to award values of zero through fifty in 60% of the bonus games, 51 through 100 in 30% of the bonus games and over 100 in only 10% of the bonus games in a particular gaming device. Based on the probabilities, the processor picks a total award value for the bonus game and subsequently determines the number of spins and the award amounts for each spin for the game. Thus, the total award is predetermined before the game ever starts, yet the player plays the bonus game as if the award is still to be determined. In yet another embodiment, each section is associated with a probability such that one section is more likely to be indicated than another section on the award wheel. For example, sections including large value awards have a lower probability of being indicated by the indicator than sections including relatively lower valued awards. In each of the above embodiments, the players always have an opportunity or chance to obtain each section on the award wheel whether the section includes a terminator or an award. Therefore, although the section probabilities may change in a bonus game, the players maintain their excitement and enjoyment of the bonus game. Referring now to FIG. 7, a further embodiment of the present invention where the annular areas 102 are alternately illuminated until an area is selected by the gaming device. Then the sections 104 within the selected annular area 102 are alternately illuminated until a section is selected. For example, the annular area 102a was selected by the gaming device. Then the gaming device selected section 124 within annular area 102a as the section provided to the player. The player receives an award of seventy-five associated with section 124. Referring now to FIG. 8, another embodiment of the present invention is illustrated where the multi-coordinate award wheel 100 is a square. The award wheel 100 may be any shape or configuration as desired by the game implementor. In FIG. 8, the award wheel 100 includes square areas 126a, 126b and 126c. Each area is further divided into sections 104 that include awards 106. The sections each have an X coordinate and a Y-coordinate. An X,Y coordinate defines each of the sections displayed to the player. In operation, the gaming device alternately illuminates square areas 126a to 126c one at a time. The gaming device then picks one of the areas. Once an area 102 is picked, the section indicator 108 moves along the perimeter of the outside square 102a until a section is indicated. When the section indicator stops, a section 104 within the illuminated area 126 is determined. The award associated with this section is provided to the player and displayed in the total award display 114. The player continues to play the bonus game until the player runs out of spins in the bonus game. In another embodiment of the present invention is illustrated where the award wheel sections 104 include an annular area 102 that has several low value awards, an annular area that has medium value awards and a annular area that has several high value awards. The probability of obtaining each low value award is preferably greater than the probability of obtaining the high value awards or the terminator. The award disparity creates enhanced levels of excitement for players because the player may obtain the large award. Additionally, the player is likely to obtain multiple spins in the bonus game because the probability of obtaining a low value award is higher than obtaining the terminator. Thus, each additional spin increases the players excitement and enjoyment of the game because each spin means an additional opportunity to obtain the large award. Even if the player does not obtain the large award, the player still obtains several awards in the bonus game and may accumulate a large award before obtaining a terminator. It should be appreciated that the terminator symbol could be a blank symbol and that one or more blank symbols could function as terminator symbol or can have no function or other functions. For instance, the occurrence of one or more blank symbols could provide alternative awards. Referring now to FIG. 9, an alternative embodiment of the present invention is illustrated where the sections 204 on the award wheel 200 include a plurality of awards and a plurality of award percentages. Specifically, the award wheel 200 includes a plurality of sections 202, wherein the sections are arranged in a plurality of groups. The groups of sections include a symbol group, which includes the sections in annular area 203a, and a plurality of modifier groups, which include the sections in annular areas 203b, 203c, 203d and 203e. It should be appreciated that although the groups in this embodiment include the sections in the annular areas on the award wheel 200, the groups may include any suitable number of sections or arrangement of sections. In one embodiment, a plurality of awards, such as award values or credits, are associated with the sections in the symbol group or annular area 203a. The awards may include values, multipliers, modifiers, monetary prizes, non-monetary prizes, physical prizes or any suitable type of award. It should also be appreciated that any of the annular areas or groups on the award wheel 200 may include sections having one or more awards. A plurality of award portions or award percentages 206 are associated with the sections in the modifier groups or annular areas 203b, 203c, 203d and 203e. In this embodiment, modifier group or annular area 203b includes award percentages of 100% associated with each of the sections in this group. Modifier group or annular area 203c includes award percentages of 75% associated with each of the sections in the group. Modifier group or annular area 203d includes award percentages of 50% associated with each of the sections in the group. Additionally, modifier group or annular area 203e includes award percentages of 25% associated with each of the sections in this group. It should be appreciated that the award percentages may be any suitable award percentage desired by the game implementor. In one embodiment, as shown in FIG. 9, the award percentages associated with the sections in each of the modifier groups are the same. In another embodiment, the award percentages associated with the sections in each of the modifier groups are different. It should be appreciated that at least one of the award percentages, a plurality of the award percentages or all of the award percentages associated with the sections within each of the groups may be different. Additionally, the award percentages associated with the sections may be different from group to group. For example, as shown in FIG. 9, the award percentages associated with modifier group 203e are less than the award percentages associated with modifier group 203d. Similarly, the award percentages associated with modifier groups 203c and 203b incrementally increase. It should be appreciated that the award percentages associated with the sections in the groups may increase from the innermost annular area or modifier group 203e to the outermost annular area or group 203b. The award percentages may also decrease from modifier group or annular area 203e to modifier group or annular area 203b. It should be appreciated that any suitable award percentages may be associated with the sections in each of the modifier groups. Furthermore, the award percentages in FIG. 9 are shown as percentages or percentage values. However, the award percentages may be represented as fractions, decimals or any other suitable type of award portion, fraction or percentage. As will be explained below, the gaming device indicates an award percentage and an award in each activation or spin of the award wheel 200. The indicated award percentage is multiplied by the or applied to an indicated award in the symbol group to provide an activation or spin award to the player for that activation or spin. For example, when an indicated section includes an award percentage of 25% (0.25), the gaming device provides the player with 25% of the award associated with the indicated section in the symbol group. In other words, the gaming device multiplies the indicated award by 0.25 to provide an activation award to the player for that activation or spin. Similarly, the gaming device provides 50%, 75%, and 100% of the indicated awards when each of those award percentages are indicated on the award wheel. In one embodiment, each of the modifier groups or annular areas 203a, 203b, 203c, 203d and 203e are included on the same wheel and rotate in the same direction. In another embodiment, at least one of the modifier groups or annular areas 203 is included on a separate wheel from the other annular areas. In this embodiment, the wheels may rotate in the same direction or in different directions. In a further embodiment, each of the modifier groups or annular areas 203 are included on separate wheels. The wheels may rotate in the same direction, at least one may rotate in different directions from the other wheels or a plurality of the wheels may rotate in a different direction. It should be appreciated that the modifier groups 203 may be included on the same or different wheels and rotate in any suitable direction desired by the game implementor. It should also be appreciated that the award wheel 200 may be stationary and the section indicator 208 may rotate about the perimeter of the award wheel in a clockwise or counterclockwise direction. The gaming device also includes a bonus award such as a big bonus award 207. In one embodiment, the gaming device provides a player with the big bonus award 207 when the player accumulates all of the sections associated with an award (i.e., each of the sections associated with an award are indicated or illuminated in the game). It should be appreciated that the big bonus award may be provided to the player based on any suitable number of indicated sections in the game, or other combinations of indicated sections in the game. The big bonus award 207 indicated in the middle of the award wheel 200 includes a masked or hidden award that is provided to the player by the gaming device when all of the award percentages associated with a particular award indicated in the game (i.e, in the number of spins of the wheel provided to the player). It should be appreciated that the big bonus award may be provided to the player when a designated number of sections in an annular area, a plurality of annular areas, a pie-shaped section, a plurality pie shaped sections, or any other suitable section or area on the wheel are indicated in a game. The big bonus award may be an award value, a modifier, a multiplier, free spins, free games or any other suitable award. The big bonus award 207 is provided to the player in the game or in a subsequent game (i.e, free spins) or added to the player's total award in the game (i.e, an award value or credits). It should be appreciated that the big bonus award 207 may be masked or displayed to the player in the game. Additionally, a spins remaining display 210 indicates the number of spins remaining in the game. A spin award display 212 (or activation award display) and a total award display 214 indicate the award associated with a particular activation or spin in the game and the total accumulated award provided to the player in the game, respectively. Referring to FIGS. 10A to 10M, an example of the embodiment of FIG. 9 is illustrated where the gaming device provides a player with six activations or spins at the beginning of the game. Also, the player's total award is zero as indicated by the total award display 214. In this example, the award wheel 200 includes a plurality of sections 202. The sections are included in a plurality of groups on the wheel. The groups include a symbol group or annular area 203a and a plurality of modifier groups or annular areas 203b, 203c, 203d and 203e. A plurality of awards 204 are associated with the sections of the symbol group 203a and a plurality of award percentages 206 are associated with the sections in modifier groups 203b, 203c, 203d, and 203e. It should be appreciated that the sections in the modifier groups 203b, 203c, 203d and 203e may also include fixed amounts such as fixed awards which increase in value from annular area 203e to annular area 203a, decrease in value from annular area 203e to annular area 203a or include any suitable fixed amounts or awards. In this example, the award wheel is a single award wheel including all of the groups of sections or annular areas 203. The wheel rotates or spins in a clockwise direction as indicated by the arrow 209. Referring to FIG. 10B initially, the gaming device and processor alternately illuminate each of the groups of sections or annular areas 203 on the award wheel 200. For example, all of the sections and symbol group 203a are highlighted or illuminated and then all the sections in modifier group 203b are highlighted or illuminated and each subsequent group is then highlighted or illuminated. The indicated modifier group remains highlighted or illuminated until the section indicator 208 indicates one of the sections in that group. This illumination pattern repeats until the processor picks one or stops on one of the groups or annular areas. It should be appreciated that the groups or annular areas 203 may be highlighted or illuminated in any order or sequence. It should also be appreciated that one or more of the groups or annular areas 203 may be simultaneously highlighted or illuminated during the game. Additionally, it should be appreciated that the gaming device may not include a section indicator 208 and therefore indicates the sections on the wheel by illuminating an annular area and then subsequently illuminating a section in the indicated annular area. The sections may also be indicated by raising or lowering the indicated sections on the wheel such as on a mechanical wheel. The raising and lowering of the sections to indicate the sections on the wheel may also be accomplished in a video-type wheel where a three dimensional virtual wheel is displayed to the player. On a video wheel, the individual sections would rise or move upwards to indicate the indicated section on the wheel in a spin. It should be appreciated that one section, a plurality of the sections or all the sections may raise and/or lower simultaneously or alternately in a spin or plurality of spins in a game. As described above, the present invention may employ a mechanical or electrical mechanical wheel, an electronic wheel or a video wheel displayed on a display device. In FIG. 10B, the gaming device alternately illuminates the modifier groups on the award wheel 200 until stopping on modifier group 203e. Award percentages of 25% are associated with each of the sections in the indicated modifier group 203e. After the group is indicated, the gaming device or player activates or spins the award wheel 200 in a clockwise direction as shown by arrow 209 to indicate one of the sections in the highlighted or indicated modifier group 203e. In this example, the gaming device spins the award wheel 200 and the section indicator 208 indicates one of the sections in the modifier group and also one of the sections in the symbol group. The award associated with the indicated section in the symbol group 203a is modified by or multiplied by the award percentage associated with the indicated section in the indicated modifier group. Referring to FIG. 1C, the section indicator 208 indicates one of the sections in the symbol group 203a having an associated award of one hundred and a section in the modifier group 203a having an award percentage of 25%. Thus, the award of one hundred is multiplied by the indicated award percentage 25% to give a multiplied award of twenty-five. The multiplied award is the activation award or spin award for that spin in the game. In this example, the spin award is twenty-five (100×0.25). Because the total award was zero at the beginning of the game, the player's new total award is twenty-five, as indicated by the total award display 214. The player now has five spins remaining as indicated by the spins remaining display 210. In this example, the award percentage associated with the indicated section on the award wheel remains highlighted or indicated in the subsequent spins in the game. This enables a player to accumulate the award percentages in the game and attempt to accumulate all of the award percentages associated with a particular award in the game. By keeping the indicated sections highlighted or illuminated in the game, the gaming device provides a visual indicator of how the player is progressing in the game and also how many more sections the player needs to obtain to achieve an additional award or big bonus award in the game. Thus, the player's enjoyment and excitement increases in the games. If the player accumulates all of the award percentages associated with a particular award, the gaming device provides the player with the big bonus award 207 as described above. In this example, the gaming device provides an additional award of five hundred for the big bonus award 207. Referring to FIG. 10D, the gaming device alternately illuminates the modifier group or annular areas 203 and stops on modifier group 203d. The modifier group 203d remains highlighted as shown in FIG. 10C until the gaming device or player spins the wheel to indicate one of the sections in that group. Modifier group 203d includes sections having an award percentage of 50% (0.50). Therefore, any award associated with a section indicated by the section indicator 208 in the symbol group 203a will be multiplied by 50% or 0.50 to provide the player with a spin award for that spin. As shown in FIG. 10D, the award percentage associated with the indicated section remains highlighted as shown by the box or border around that award percentage. Referring to FIG. 10E, the gaming device spins the award wheel in a clockwise direction to determine the angular coordinate of a section included in the indicated modifier group or annular area 203d. In this example, the section indicator 208 indicates a section in the modifier group 203d including an award percentage of 25% and a section in the symbol group having an award of twenty. The gaming device therefore multiples the award of twenty by 50% or 0.50 to provide the player with a spin award of ten (20×0.50) for that spin as indicated by the spin award display 212. The award of ten is added to the player's previous total award of twenty-five to provide the player with a new total award of thirty-five as indicated by the total award display 214. The player now has four spins remaining in the game as indicated by the spins remaining display 210. Referring to FIG. 10F, the gaming device alternately illuminates the modifier groups or annular areas 203 and stops on modifier group 203d. As in the previous spin, annular area 203d includes sections having award percentages of 50%. Thus, any award indicated by section indicator 208 will be multiplied by 50% or 0.50 to provide the player with a spin award in that spin. Referring to FIG. 10G, the gaming device spins the award wheel 200 and the section indicator 208 indicates a section in the symbol group or annular area 203a having an award of one hundred. This is the second time in the game that the award of one hundred has been indicated and therefore the player now has indicated two of the sections associated with the award of one hundred include the award percentages of 25% and 50%. If the two remaining sections associated with the award of one hundred, including the award percentages of 75% and 100%, are indicated by the section indicator 208 in this game, the player wins the big bonus 207. The gaming device provides the player with a spin award that equals 50% or 0.50 of the indicated award of one hundred. Therefore, the gaming device provides the player with a spin award of fifty (100×0.50) as indicated by the spin award display 212. The spin award of fifty is added to the player's total award of thirty-five to provide the player with a new total award of eighty-five as indicated by the total award display 214. The player now has three spins remaining in the game as indicated by the spins remaining display 210. Referring to FIG. 10H, the gaming device alternatively illuminates the modifier groups or annular areas 203 and selects modifier group 203c. Modifier group or annular area 203c remains highlighted until the player spins the award wheel 200 to indicate a section in this group. Additionally, modifier group 203c includes sections having award percentages of 75%. Thus, any award indicated by the section indicator 208 will be multiplied by 75% to provide a spin award to the player for that spin. Referring to FIG. 101, the gaming device spins the award wheel 200 and the section indicator 208 indicates a section including an award of one hundred. Thus, the gaming device provides the player with 75% (100×0.75) of the indicated award of one hundred or an award of seventy-five (100×0.75). The award of seventy-five (100×0.75) is indicated by the spin award display 212. In addition, the award of seventy-five (100×0.75) is added to the player's previous total award and the player now has a new total award of one hundred sixty as indicated by the total award display 214. The player now has two spins remaining in the game as indicated by the spins remaining display 210. Referring to FIG. 10J, the gaming device alternatively illuminates the modifier groups 203 and selects group 203c. The sections included in the modifier group or annular area 203c include award percentages of 75%. The annular area 203c remains highlighted until the gaming device spins the award wheel 200 to indicate a section in this group. Referring to FIG. 10K, the gaming device spins the award wheel 200 and the section indicator 208 indicates a section in the symbol group 203a having an award of ten. Thus, the gaming device multiplies the award of ten by 75% to produce an award of seven and one-half (i.e., 7.5) for that spin. In this example, the gaming device only provides awards having whole numbers or integers and therefore does not provide the player with an award of seven and one-half (i.e., 7.5). Instead, the gaming device rounds the award of seven and one-half (i.e., 7.5) to an award of eight and provides that award to the player for this spin. It should be appreciated however, that the gaming device may round the number up, round the number down, provide the player with the decimal award or any suitable award desired by the game implementor. The spin award of eight is then indicated by the spin award display 212 and added to the player's previous total award of one hundred sixty. The player's new total award is one hundred sixty-eight, as indicated by the total award display 214. The player has one spin remaining in the game as indicated by the spins remaining display 210. As shown in FIGS. 10J and 10K, all the previously indicated sections in the modifier groups on the award wheel 200 remain highlighted or otherwise indicated to show that these awards were previously indicated in the game. This enables a player to track or see which modifiers or sections the player has obtained and which modifiers the player still needs to indicate to obtain the big bonus award 207 in the remaining spins in the game. Referring to FIG. 10L, the gaming device alternately illuminates the modifier groups or annular areas 203 and stops on the modifier group 203b. Modifier group 203b includes sections having an award percentage of 100%. The gaming device will therefore multiply any awards indicated in the symbol group in this spin by 100% (i.e., provide the entire award to the player). Referring to FIG. 10M, the gaming device spins the award wheel and the section indicator 208 indicates a section in symbol group 203a including an award of one hundred. In this game, the sections including the award percentages of 25%, 50% and 75% have already been indicated by the section indicator 208 as shown by the boxes or borders surrounding the award percentages associated with those sections. In this spin, the fourth or final section including the award percentage of 100% is indicated by the section indicator in the game. The gaming device therefore provides 100% of the award of one hundred to the player or a spin award of one hundred. Additionally, because the player indicated all of the sections in the symbol groups 203 associated with a single award (i.e., the award of one hundred), the gaming device provides the player with the big bonus award 207 as shown in FIG. 10M. In this example, the big bonus award 207 includes an award of five hundred as described above. The big bonus award of five hundred is added to the player's spin award of one hundred to provide the player with a total spin award of six hundred as indicated by the spin award display 212. The spin award of six hundred is then added to the player's previous total award of one hundred sixty-eight to provide the player with a new total award of seven hundred sixty-eight as indicated by the total award display 214. The player does not have any spins remaining as indicated by the spins remaining display 210 and therefore, the game ends. The gaming device provides the player with the total award of seven hundred sixty-eight indicated in the total award display 214 for the game. Referring to FIG. 11, another alternative embodiment of the present invention is illustrated where the modifier group or annular area 303a includes sections having different multipliers. Also, modifier groups 303b, 303c, 303d and 303e include sections having award percentages. In this embodiment, the gaming device alternatively illuminates the modifier groups or annular areas 303 until picking one of the groups. The gaming device then spins the award wheel in a clockwise direction as shown by arrow 309. The section indicated by the section indicator 308 in the indicated modifier group is associated with one of the multipliers 304 in that group. The gaming device then multiplies the multiplier 304 associated with the indicated section in the highlighted modifier group to provide the player with a multiplier for that spin. For example, a section in the modifier group 303e including an award percentage of 25% is indicated by the section indicator 308 as shown in FIG. 11. The indicated section is associated with a multiplier of one hundred, which is also indicated by the section indicator 308. The multiplier provided to the player for that spin therefore is 25% of the multiplier one hundred, which is a multiplier of 25 or 25×. The multiplier, 25×, is then indicated by the spin award display 312. In one embodiment, an award provided to the player in a primary or base game is multiplied by the multiplier indicated by that spin (i.e., 25×). In another embodiment, the gaming device provides a predetermined award in the game such as in a secondary or bonus game, and that award is multiplied by the indicated multiplier in that spin. In this example, the gaming device randomly provided the player with an award of ten for that spin and therefore the award of ten is multiplied by the spin award of 25× to provide the player with a total award of two hundred fifty as indicated by the total award display 314. It should be appreciated that the gaming device may accumulate the multipliers obtained in the spins in the game and use the total multiplier to multiply a previous award or a subsequent award in the game. It should also be appreciated that the multipliers indicated in the symbol groups or annular areas 303a may be any suitable multipliers desired by the game implementor. Referring to FIG. 12, a further alternative embodiment of the present invention is illustrated where the award wheel 400 includes a plurality of groups or annular areas 403 including sections 402. In this embodiment, the group or annular area 403a includes sections having a plurality of awards 404 and prizes 409. The awards may be any suitable type of awards and the prizes 409 may include any suitable prizes such as a car, a free spin or spins, a boat, cash, or a trip. As described above, a gaming device alternatively illuminates the annular areas 403 to indicate one of the areas in that spin. The gaming device then spins the award wheel 400 in a clockwise direction as shown by arrow 413 to indicate one of the sections in the indicated annular area 403. If a section including an award percentage 406 is indicated, the gaming device provides the player with the award associated with the indicated section the symbol group 403a. The multiplied award is then indicated in the spin award display 412. Each prize 409 includes sections that have letters 410 which spell out a word or words associated with the prize. If the player indicates all of the sections (i.e., accumulates all the letters or sections associates with that prize), the gaming device provides the prize to the player in the game. For example, if the player spins the wheel in the game and indicates all of the letters including the blank space associated with the car, the gaming device provides the car to the player. Additionally, if the player indicates all of the sections including all of the award percentages associated with the award, the gaming device provides the player with the big bonus award 411. It should be appreciated that the big bonus award 411 may be provided to the player when the player indicates all the sections associated with one of the awards or one of the prizes. The addition of the prizes to the game increases the excitement and enjoyment of the game for the player. If the player wins one of the prizes, the gaming device indicates the prize in the spin award display 412. A receipt or suitable redemption coupon is printed by the gaming device and the player redeems the prize at a remote location or other suitable redemption location. Referring to FIG. 13, another alternative embodiment of the present invention is illustrated where the award wheel 500 includes groups or annular areas 503a, 503b, 503c, 503d and 503e. In this embodiment, the groups include sections 502 having awards and award percentages. The awards 504 may be any suitable type of awards desired by the game implementor. Each of the annular areas 503 include separate wheels such that each of the wheels independently rotates with respect to the other wheels. Additionally, each of the sections 502 associated with the groups 503b, 503c, 503d and 503e include a plurality of different award percentages. For example, the award percentages associated with group 503b are different than the award percentages associated with groups 503c, 503d and 503e. In a game therefore, the gaming device alternatively illuminates the groups or wheels 503 to indicate one of the groups or wheels in that spin. The gaming device then spins one or more of the wheels including the groups to indicate one of the sections in the highlighted or indicated group. The indicated section includes an award percentage 506. The section indicator also indicates a section in the symbol group 503a having an award 504. The indicated award 504 is multiplied by the indicated award percentage 506 to provide a spin award or multiplied award to the player in that spin. The player then spins the wheel or wheels until there are no spins remaining in the game. The different award percentages provide an extra level of excitement and enjoyment to a player in a game because the player's award depends on two factors. One factor is the award indicated by the section indicator 508 in a spin and the second factor is the award percentage indicated in that spin. Also, because the award wheels all independently rotate, it is more difficult to accumulate all of the sections associated with the particular award because one or more of the wheels including the sections are moving in each spin. In another embodiment, the gaming device enables a player to pick or select an annular area or pie-shaped area or segment of the wheel prior to playing the game or initiating the spins of wheel in the game. It should be appreciated that the gaming device may enable the player to pick one, a plurality or the annular areas and/or pie-shaped segments or areas of the wheel in a game. It should also be appreciated that the gaming device may enable the player to pick the annular area or areas or pie-shaped section or sections prior to playing the game, prior to one spin in the game or prior to a plurality of the spins in the game. For example, a player picks one of the annular areas on the wheel and then spins the wheel. The section indicator indicates one of the sections in the annular area picked by the player and provides the award associated with that section. It should be appreciated that the gaming device may enable the player to pick one of the annular areas or pie-shaped sections by pressing or touching the corresponding annular area or section on a touch screen display device or by pressing a button or similar input device which corresponds to the annular area or pie-shaped section on the wheel. In a further embodiment, the gaming device of the present invention is employed in a progressive type game where a player accumulates indicated sections on the wheel in the plurality of games. In this embodiment, the indicated sections remain highlighted or illuminated for a designated number of games. The designated number of games may be predetermined, randomly determined or determined in any suitable manner. The progressive accumulation of the indicated sections enables one or more players to be able to accumulate multiple sections in a game or games and also increases the probability that a player will obtain the big bonus award by accumulating all the sections associated with one of the awards in the outer most annular area in a game. In one aspect of this embodiment, the awards are associated with a probability of being indicated such that the relatively small awards include greater probabilities than the relatively large awards. In this aspect, a significant portion of the relatively small awards are indicated before the relatively large awards are indicated on the wheel. This creates excitement and enjoyment of the game because the longer the game is played or the more games that are played, more of the sections of the wheel are illuminated or indicated. Also, as more sections are indicated on the wheel, the awards associated with the non-indicated sections increase to enable players to obtain larger awards in a game or games. Once the designated number of games are reached, the gaming device resets the award wheel so that none of the sections are indicated (i.e., highlighted) on the wheel. It should be appreciated that the gaming device may reset the award wheel so that none, one, a plurality or all of the sections remain highlighted on the wheel. In another embodiment, a plurality of section indicators are associated with the wheel such that multiple sections are indicated on the wheel in a spin. This enables a player to obtain multiple awards associated with the multiple sections indicated on the wheel in a single spin. In one embodiment, the section indicators associated with the wheel are activated such that only the activated section indicators indicate sections on the wheel. The section indicators may be activated by particular sections on the wheel or based on the number of spins provided to the player in the game. The number of section indicators may also be based on a wager made by the player in the base game or in a bonus game. In a further embodiment the multiple section indicators are moveable such that the section indicators move about the wheel at the beginning of a game and are stopped or locked in place by the gaming device or the player. The section indicators may move at the beginning of the game, during the game, after one spin or a plurality of the spins of the wheel or at any suitable point in a game. The moveable indicators enable the player to interact with the game and therefore provides additional excitement and enjoyment of the game. In another embodiment, a time dimension is associated with the present invention to offer enhanced play and awards in the game. In one aspect of this embodiment, a larger award or awards are provided to the player when a designated number of sections are indicated in a designated number of spins of the wheel. For example, the gaming device provides a larger award or a bonus award to a player when the player indicates all of the sections associated with one of the awards in a particular number of spins such as five spins. The gaming device decreases the award for each additional spin or spins needed by the player to indicate those sections. In another aspect of this embodiment, the gaming device only provides a bonus award when the player indicates a specific section or sections in a designated number of spins. If the section or sections are indicated after the designated number of spins are reached, the gaming device does not provide a bonus or extra award to the player. It should be appreciated that the designated section or sections may be predetermined, randomly determined or determined according to any suitable determination method. In a further aspect of this embodiment, a time period is associated with the game such that the gaming device or the player spins the wheel during the time period and indicates sections and accumulates awards associated with those sections during the time period. When the time period expires, the game ends and the player receives the total accumulative award for the game. It should be appreciated that the present invention may be employed in a primary or base game or, a secondary or bonus game or any suitable type of game such as poker, blackjack, roulette, dice, slots, multi-line slots or any other suitable wagering game. It should also be appreciated that multiple pointers or indicators for simultaneously indicating different sections may be employed in the present invention. While the present invention is described in connection with what is presently considered to be the most practical and preferred embodiments, it should be appreciated that the invention is not limited to the disclosed embodiments, and is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims. Modifications and variations in the present invention may be made without departing from the novel aspects of the invention as defined in the claims, and this application is limited only by the scope of the claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Gaming device manufacturers strive to make gaming devices that provide as much enjoyment and excitement as possible. Providing a secondary or bonus game in which a player has an opportunity to win potentially large awards or credits in addition to the awards associated with the primary or base game of the gaming device is one way to enhance player enjoyment and excitement. Gaming devices having bonus games generally employ a triggering event that occurs during the base game operation of the gaming device. The triggering event temporarily stalls or halts the base game play and enables a player to enter a second, different game, which is the bonus game. The player plays the bonus game, likely receives an award, and returns to the base game. One known bonus game is in the WHEEL OF FORTUNE® gaming device manufactured by the assignee of this application. In this game, a multi-colored award wheel is attached to a cabinet of the gaming device. The award wheel is divided into several sections. Each section includes an award that ranges in value from twenty to one thousand. In this game, a player plays a base game that includes spinning reels and a central payline. When the wheel symbol is positioned along the central payline on the third reel, the player enters the bonus game. In the bonus game, the player obtains one opportunity or spin of the award wheel. The player spins the award wheel by pressing a button on the gaming device. Once the award wheel starts spinning, the player waits until it stops. An indicator located at the top of the award wheel points to a section of the wheel. The player receives the award on that section for the bonus game. After the player receives that award, the bonus game ends and the player can resume playing the base game. Another known game is described in U.S. Pat. No. 6,059,658 to Mangano et al. This patent relates to a spinning award wheel game. The game includes a display having five concentrically arranged wheels. Each wheel has indicia designated with an Ace, King, Queen, Jack, Ten and a wild symbol along the outer edge of the circles. Once a player enters the game, the player initiates the spinning of the wheels. Each wheel rotates independently of the other wheels. The object of the game is to align winning combinations of indicia, which in this game are winning hands in poker. A indicator points to a sequence of five indicia formed from each of the five rotating wheels. If the sequence equals a winning combination, the player receives an award. To increase player enjoyment and excitement, therefore, it is desirable to provide new bonus games having award wheels that provide larger awards to players with minimal risk. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a gaming device and in particular a bonus game of a gaming device that enables players to accumulate awards by obtaining sections on an award distributor such as an award wheel based on the coordinates of the sections. In one embodiment, the award wheel includes several annular areas or groups that are each divided into a plurality of sections. The sections are each defined by first and second coordinates on the award wheel and include award symbols that are associated with awards. The coordinates define the location of each section on the award wheel. Initially, the gaming device alternately illuminates each annular area, which defines the first coordinate of the groups of sections in the annular areas. In one embodiment, the gaming device picks one of the annular areas. In another embodiment, the gaming device enables the player to pick one of the annular areas where the awards associated with the annular areas are approximately equal. Once the first coordinate is defined by selecting one of the annular areas on the award wheel, the gaming device or player activates or spins the award wheel. When the wheel stops spinning, a section indicator indicates a second coordinate which together with the first coordinate, defines the determined section in the annular area. The player receives the award associated with the section that is defined by the indicated first and second coordinates. In one embodiment, the player continues to play the bonus game until the player is out of activations or spins of the award wheel. In one preferred embodiment, the award wheel is divided into several groups or annular areas where each of the annular areas is further divided into several sections. The first coordinate of a group of sections is represented by the radial distance from the center of the award wheel to the annular area. The second coordinate of one of the sections in the group is defined by the angular location of a section along the annular area. Each section includes a symbol such as an award symbol. A plurality of awards are associated with the award symbols. In one embodiment, the awards associated with the sections in the innermost annular areas of the award wheel are substantially lower awards than the awards associated with the sections located in the outermost annular areas of the wheel. Each annular area is alternately highlighted or illuminated at the start of the bonus game by an illumination device. The annular areas alternately light up, one at a time, until only one area is randomly selected and remains illuminated. In one embodiment, the gaming device (i.e., the processor) determines the indicated annular area. In another embodiment, the gaming device enables the player to pick the annular area as described above. Next, the gaming device or player activates or spins the award wheel. Once the wheel stops spinning, the section indicator indicates one of the sections in the indicated or highlighted annular area. The player receives the award associated with the indicated section. The player continues to play the bonus game until the player has no spins remaining in the game. In another embodiment, the award wheel first is spun to indicate a pie-shaped area of the wheel. Each pie-shaped section is further divided into individual sections by the annular areas on the wheels. Then, the sections in the indicated pie-shaped area are alternately illuminated until one section is randomly selected and remains illuminated. The player receives the award associated with that selected section. In a further embodiment, an annular area is illuminated and defines the first coordinate of a group of sections. Then the indicator spins about the perimeter of the award wheel to define the second coordinate of one of the sections in the illuminated annular area. When the indicator stops, the indicated first and second coordinates define the indicated section on the award wheel. The gaming devices provides the player with the award associated with the indicated section defined by the determined first and second coordinates. In an alternative embodiment of the present invention the sections on the award wheel include a plurality of awards and a plurality of award percentages. Specifically, the award wheel includes a plurality of sections wherein the sections are arranged in a plurality of groups. The groups of sections include a symbol group, which includes the sections in the outermost annular area and a plurality of modifier groups, which include the sections in inner annular areas. In one embodiment, a plurality of awards, such as award values or credits, are associated with the sections in the symbol group. The awards may include values, multipliers, modifiers, monetary prizes, non-monetary prizes, physical prizes or any suitable type of award. It should be appreciated that any of the annular areas or groups on the award wheel may include sections having one or more awards. Additionally, a plurality of award portions or award percentages are associated with the sections in the modifier groups. In one embodiment, the modifier groups include award percentages of 100%, 75%, 50% and 25% associated with each of the sections in these groups. The award percentages may be any suitable award percentages desired by the game implementor. In one embodiment, the award percentages associated with the sections in each of the modifier groups are the same. In another embodiment, the award percentages associated with the sections in each of the modifier groups are different. It should be appreciated that at least one of the award percentages, a plurality of the award percentages or all of the award percentages associated with the sections within each of the groups may be different. Additionally, the award percentages associated with the sections may be different from group to group. In one embodiment, the award percentages associated with the sections in the groups increase from the innermost annular area to the outermost annular area. In another embodiment, the award percentages decrease from the innermost modifier group to outermost modifier group. Furthermore, the award percentages may be represented as fractions, decimals or any other suitable type of award portion, fraction or percentage. In an operational embodiment, the gaming device indicates an award percentage and an award in each activation or spin of the award wheel. The indicated award percentage is multiplied by the or applied to an indicated award in the symbol group to provide an activation or spin award to the player for that activation or spin. For example, when an indicated section includes an award percentage of 75% (0.75), the gaming device provides the player with 75% of the award associated with the indicated section in the symbol group. In other words, the gaming device multiplies the indicated award by 0.75 to provide an activation award to the player for that activation or spin. In one embodiment, each of the modifier groups are included on the same wheel and rotate in the same direction. In another embodiment, at least one of the modifier groups is included on a separate wheel from the other annular areas. In this embodiment, the wheels may rotate in the same direction or in different directions. In a further embodiment, each of the modifier groups are included on separate wheels. The wheels may rotate in the same direction, at least one may rotate in different directions from the other wheels or a plurality of the wheels may rotate in a different direction. In a further embodiment, the award wheel may also remain stationary and the section indicator may rotate about the perimeter of the award wheel in a clockwise or counterclockwise direction. The gaming device also includes an additional bonus award such as a big bonus award. In one embodiment, the big bonus award is indicated in the middle of the award wheel includes a masked or hidden award provided to the player by the gaming device when all of the award percentages associated with a particular award are indicated in the game (i.e., in the number of spins of the wheel provided to the player). The big bonus award may be an award value, a modifier, a multiplier, free spins, free games or any other suitable award. The big bonus award is provided to the player in the game or in a subsequent game (i.e, free spins) or added to the player's total award in the game (i.e, an award value or credits). In another embodiment, the gaming device enables a player to pick or select an annular area or pie-shaped area or segment of the wheel prior to playing the game or initiating the spins of the wheel in the game. It should be appreciated that the gaming device may enable the player to pick one, a plurality or the annular areas and/or pie-shaped segments or areas of the wheel in a game. It should also be appreciated that the gaming device may enable the player to pick the annular area or areas or pie-shaped section or sections prior to playing the game, prior to one spin in the game or prior to a plurality of the spins in the game. In one embodiment, the gaming device enables the player to pick one of the annular areas or pie-shaped sections by pressing or touching the corresponding annular area or pie-shaped section on a touch screen display device or by pressing a button or similar input device which corresponds to the annular area or pie-shaped section on the wheel. In a further embodiment, the gaming device of the present invention is employed in a progressive type game where a player accumulates indicated sections on the wheel in a plurality of games. In this embodiment, the indicated sections remain highlighted or illuminated for a designated number of games. The designated number of games may be predetermined, randomly determined or determined in any suitable manner. In one aspect of this embodiment, the awards are associated with a probability of being indicated such that the relatively small awards include greater probabilities than the relatively large awards. In this aspect, a significant portion of the relatively small awards are indicated before the relatively large awards are indicated on the wheel. Once the designated number of games are reached, the gaming device resets the award wheel so that none of the sections are indicated (i.e., highlighted) on the wheel. It should be appreciated that the gaming device may reset the award wheel so that none, one, a plurality or all of the sections are highlighted on the wheel. In another embodiment, a plurality of section indicators are associated with the wheel such that multiple sections are indicated on the wheel in a spin. This enables a player to obtain multiple awards associated with the multiple sections indicated on the wheel in a single spin. In one embodiment, the section indicators associated with the wheel are activated such that only the activated section indicators indicate sections on the wheel. The section indicators may be activated by particular sections on the wheel or based on the number of spins provided to the player in the game. The number of section indicators may also be based on a wager made by the player in the base game or in a bonus game. In a further embodiment the multiple section indicators are moveable such that the section indicators move about the wheel at the beginning of a game and are stopped or locked in place by the gaming device or the player. The section indicators may move at the beginning of the game, during the game, after one spin or a plurality of the spins of the wheel or at any suitable point in a game. The moveable indicators enable the player to interact with the game and therefore provides additional excitement and enjoyment of the game. In another embodiment, a time dimension is associated with the present invention to offer enhanced play and awards in the game. In one aspect of this embodiment, a larger award or a plurality of awards are provided to the player when a designated number of sections are indicated in a designated number of spins of the wheel. For example, the gaming device provides a larger award or a bonus award to a player when the player indicates all of the sections associated with one of the awards in a particular number of spins of the award wheel. The gaming device decreases the award for each additional spin or spins needed by the player to indicate those sections. In another aspect of this embodiment, the gaming device only provides a bonus award when the player indicates a specific section or sections in a designated number of spins. If the sections or sections are indicated after the designated number of spins are reached, the gaming device does not provide a bonus or extra award to the player. It should be appreciated that the designated section or sections may be predetermined, randomly determined or determined according to any suitable determination method. In a further aspect of this embodiment, a time period is associated with the game such that the gaming device or the player spins the wheel during the time period and indicates sections and accumulates awards associated with those sections during the time period. When the time period expires, the game ends and the player receives the total accumulative award for the game. The present invention may be employed in a primary or base game or, a secondary or bonus game or any suitable type of game such as poker, blackjack, roulette, dice, slots, multi-line slots or any other suitable wagering game. It is therefore an advantage of the present invention to provide a gaming device having a multi-coordinate wheel with an alternating bonus award where awards and award percentages are associated with multi-coordinate locations on the award wheel. Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like numerals refer to like parts, elements, components, steps and processes. | 20040129 | 20080408 | 20050203 | 94760.0 | 0 | DUFFY, DAVID W | GAMING DEVICE HAVING A MULTIPLE COORDINATE AWARD DISTRIBUTOR INCLUDING AWARD PERCENTAGES | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,769,145 | ACCEPTED | Automatic fluid exchanger | A fluid exchanger for servicing the fluid circuits of vehicular power steering systems and other fluid circulating or hydraulic circuits. The fluid exchanger uses a float operated fluid control valve to harness fluid pressure provided by a pump of an accessed hydraulic circuit. The fluid control valve uses both negative and positive pressure of the circuit's pump to control fluid flow patterns. The float and fluid control valve are matched to be either mechanical/hydraulic or electrical/hydraulic in design. If the exchanger is provided with a mechanically operated fluid control valve, a mechanical float is provided in the exchanger's fresh fluid reservoir and is directly connected to the valve slide of the fluid control valve. If the exchanger is provided with an electric solenoid operated fluid control valve, a float operated electrical switch is provided in the exchanger's fresh fluid reservoir and is wired to control the solenoid of the valve. | 1. A method for exchanging a circulating fluid of an hydraulic system with a reservoir with a return port for receiving said fluid for pressure dissipation and a supply port for delivering said fluid after said pressure dissipation, a fluid pump providing negative pressure to said fluid to deliver said fluid into an inlet port while simultaneously providing positive pressure to said fluid to deliver said fluid through an outlet port, and a mechanism with a working port for receiving said fluid for actuation and a discharge port for discharging said fluid after said actuation, a supply conduit connecting said supply port to said inlet port, a working conduit connecting said outlet port to said working port, a return conduit connecting said discharge port to said return port, said method comprising steps of: providing a fresh fluid reservoir providing a used fluid receiver providing a fresh fluid exchange conduit providing a used fluid exchange conduit providing an adequate supply of fresh fluid to the fresh fluid reservoir emptying the used fluid receiver of used fluid turning off the engine of the vehicle to render the power steering pump inoperative connecting the fresh fluid exchange conduit to fluidly communicate with the supply conduit connecting the used fluid exchange conduit to fluidly communicate with the return conduit starting the engine of the vehicle to render the power steering pump operative providing a fluid control valve which is controlled by a float which when placed in its first position connects the fresh fluid exchange conduit to the fresh fluid reservoir and connects the used fluid exchange conduit to the used fluid receiver, and when placed in its second position connects the used fluid exchange conduit to the fresh fluid exchange conduit while disconnecting the fresh fluid reservoir from the fresh fluid exchange conduit and disconnecting the used fluid receiver from the used fluid exchange conduit 2. The method of claim 1 including the step of: providing a float in the fresh fluid reservoir which is responsive to the level of fresh fluid in the fresh fluid reservoir and which directs the fluid control valve into its first position upon attainment an adequate supply of fresh fluid in the fresh fluid reservoir, and directs the fluid control valve into its second position upon depletion of the fresh fluid supply. 3. The method of claim 2, wherein the float is a mechanical float and is connected to the valve slide of the fluid control valve 4. The method of claim 2, wherein the float is an electrical float switch, and the fluid control valve is actuated by an electrical solenoid, and the electrical float switch is connected to the solenoid of the fluid control valve 5. The method of claim 1 including the step of: providing a float in the used fluid receiver which is responsive to the level of used fluid in the used fluid reservoir which directs the fluid control valve, and directs the fluid control valve into its first position upon attainment an approximately empty used fluid receiver, and directs the fluid control valve into its second position upon the used fluid receiver attainment of an approximately full used fluid receiver 6. The method of claim 5, wherein the float is a mechanical float and is connected to the valve slide of the fluid control valve. 7. The method of claim 5, wherein the float is an electrical float switch, and the fluid control valve is actuated by an electrical solenoid, and the electrical float switch is connected to the solenoid of the fluid control valve 8. The method of claim 1 including the steps of: disconnecting the return hose from the return port providing a plug for the return port installing the plug on the return port removing the reservoir cap topping off the reservoir with fluid providing a reservoir cap adapter installing the reservoir cap on the reservoir and connecting it to the fresh fluid exchange conduit to deliver fluid providing a return conduit adapter connecting the return conduit to the return conduit at on end and to the used fluid exchange conduit at the other end to receive fluid removing the reservoir cap adapter removing the plug from the return port removing the adapter from the return conduit reconnecting the return conduit to the return port checking the level of fluid in the reservoir and adjusting upward or downward if necessary replacing the reservoir cap 9. The method of claim 1 including the steps of: emptying the reservoir disconnecting the return hose from the return port disconnecting the supply conduit from the supply port providing a return conduit adapter connecting the return conduit adapter to the return conduit at one end and to the used fluid exchange conduit at the other end to receive fluid providing a supply conduit adapter connecting the supply conduit adapter to the supply conduit at one end and to the fresh fluid exchange conduit at the other end 10. In an apparatus for exchanging a circulating fluid of an hydraulic system with a reservoir with a return port for receiving said fluid for pressure dissipation and a supply port for delivering said fluid after said pressure dissipation, a fluid pump providing negative pressure to said fluid to deliver said fluid into an inlet port while simultaneously providing positive pressure to said fluid to deliver said fluid through an outlet port, and a mechanism with a working port for receiving said fluid for actuation and a discharge port for discharging said fluid after said actuation, a supply conduit connecting said supply port to said inlet port, a working conduit connecting said outlet port to said working port, a return conduit connecting said discharge port to said return port, said apparatus comprising: a fresh fluid reservoir a used fluid receiver a fresh fluid exchange conduit a used fluid exchange conduit a fluid control valve which has a first position and a second position with the first position connecting the used fluid exchange conduit to the used fluid receiver and with the second position connecting the used fluid exchange conduit to the fresh fluid exchange conduit while disconnecting the fresh fluid reservoir from the fresh fluid exchange conduit and disconnecting the used fluid receiver from the used fluid exchange conduit a float which directs the fluid control valve from its first position to its second position and from its second position to its first position 11. The apparatus of claim 10, wherein the float is placed in the fresh fluid reservoir and is responsive to the level of fresh fluid in the fresh fluid reservoir and which directs the fluid control valve into its first position upon attainment an adequate supply of fresh fluid in the fresh fluid reservoir, and directs the fluid control valve into its second position upon depletion of the fresh fluid supply. 12. The apparatus of claim 1, wherein the float is a mechanical float and the fluid control valve has a valve slide by which it is operated and the float is attached to the valve slide 13. The apparatus of claim 1, wherein the float is an electrical float switch and the fluid control valve is operated by an electric solenoid, and the float switch is wired to the electric solenoid | A float operated automatic fluid exchanger for servicing the fluid circuits of vehicular power steering systems and other fluid circulating or hydraulic circuits and the like which have an accessible fluid reservoir which can be removed or adapted to provide vent free access to the negative pressure side of the circuit's pump through a hose or conduit for introducing fresh fluid while simultaneously receiving used fluid discharged by the circuit's pump. The fluid exchanger does not need its own integral on-board fluid pump for exchanging the fluid of these circuits which include vehicular power steering systems. Instead, the fluid exchanger uses a float operated fluid control valve to harness negative pressure provided by the circuit's pump to deliver fresh fluid from the exchanger's fresh fluid reservoir into the circuit and harnesses positive pressure provided by the circuit's pump to deliver used fluid from the circuit into the exchanger's used fluid receiver. The fluid control valve uses both negative and positive pressure of the circuit's pump to control fluid flow patterns while it is exchanging its fresh fluid for the used fluid of the circuit or when automatically establishing or maintaining a closed fluid circulation circuit for the circuit's pump at the completion of the fluid exchange. When the exchanger has an adequate fresh fluid supply and is properly connected to a power steering circuit by use of special adapters, the fluid control valve establishes a fluid flow pattern for exchanging the fresh fluid of the exchanger for the used fluid of the power steering circuit. When the fresh fluid supply of the exchanger becomes depleted, the fluid control valve establishes a closed fluid circulation circuit between the power steering system and the exchanger which allows the outlet port of power steering pump to communicate with its inlet port without the infusion of air or extracted used fluid. The exchanger's automatic providing of a closed fluid circulation circuit upon its fresh fluid depletion allows the service equipment operator sufficient time to reach the ignition switch of the vehicle to turn the engine off without having to worry about air becoming quickly infused and entrained in the power steering system. The float and fluid control valve are matched to be either mechanical/hydraulic or electrical/hydraulic in design. If the exchanger is provided with a mechanically operated fluid control valve, a mechanical float is provided in the exchanger's fresh fluid reservoir and is directly connected to the valve slide of the fluid control valve. If the exchanger is provided with an electric solenoid operated fluid control valve, a float operated electrical switch is provided in the exchanger's fresh fluid reservoir and is wired to control the solenoid of the valve. The positive and negative pressures provided by the power steering pump can also be harnessed and used to assist in the operation of the exchanger's fluid control valve when provided in a mechanical/hydraulic form. BACKGROUND OF THE INVENTION With the current popularity of quick lubrication type services and the current emphasis on effective vehicle maintenance by the public, there has been an increasing market for the periodic changing the fluid in vehicular power steering systems as a regular maintenance procedure. A number of power steering fluid exchangers are currently being manufactured, but the need remains for an automatic power steering fluid exchanger which has all of the following desirable characteristics: the exchanger does not require connection to a vehicle's electrical system or other source of electrical power or to a compressed air supply; the fluid exchanger has the power needed for the exchange provided by either the positive and negative pressures of the power steering pump and/or provided by the exchanger's own battery power; the fluid exchanger is compact, lightweight, portable, easy to position, simple to connect, and easy to operate; the fluid exchanger is able to automatically exchange its fresh fluid for the power steering system's used fluid in approximately equivalent volumes and rates of flow; the fluid exchanger automatically and reliably establishes a closed fluid circulation circuit between the inlet port and the outlet port of the power steering pump at the completion of the fluid exchange and maintains it until the service equipment operator turns off the vehicle's engine. Fluid exchange units for power steering currently available to vehicular service centers typically consist of two categories of units, the small and portable inexpensive units and the larger much more expensive units. The units in the first category are at the lower end of the expense continuum and are small, compact toolbox sized units which can be placed on the fender or engine of the vehicle for service use. These small, compact units typically consist of two electric pumps connected to the vehicle's battery and which are simultaneously operated to extract used fluid from the reservoir of the power steering system while also injecting fresh fluid into that reservoir to replace it. This simultaneous injection of fresh fluid and extraction of used fluid is instituted through the fill cap/dipstick opening of the power steering fluid reservoir after the reservoir cap is removed and with the engine idling to make the power steering unit operative. This first category of units have been disclosed in the Knorr in U.S. Pat. No. 5,415,247 and by Dixon in U.S. Pat. No. 6,035,902. Both feature two electrically operated pumps, each of which is connected to an associated fluid delivery hose, with one hose-pump combination conducting fresh fluid into the power steering reservoir and the other hose-pump combination extracting used fluid out of the power steering reservoir. During the fluid exchange both conduits are placed inside the reservoir at different levels and both pumps are operated simultaneously. This type of unit is compact and easy to position but because it is manually operated it must be closely monitored to prevent air infusion into the power steering system upon depletion of the fresh fluid supply. A significant drawback of this type of unit is the need to connect the unit to the vehicle's electrical system. Another drawback is its concurrent mixing of fresh fluid with contaminated used fluid in the power steering reservoir right before it is delivered to the low pressure port of the power steering pump. This tends to result in an incomplete fluid exchange typically characterized by a correspondingly lower proportion of fresh fluid exchanged for the used fluid in the circuit, compared to the second category of power steering fluid exchange units which are much more expensive and, if used properly, typically exchange a higher percentage of the used fluid for fresh. Therefore, the units of the first category, best described as “mixing type” units are only minimally effective and of limited suitability for periodic fluid exchange maintenance of power steering systems when compared to larger, more expensive units. The units of the second category, larger and more expensive, are therefore more desirable than the small mixing type units due to their higher effectiveness in exchanging fluid. However, their higher price is a drawback which can make them less available to vehicular service centers with limited funds for service equipment acquisitions. An additional drawback is that units of this second category tend to be significantly larger, heavier, less portable and therefore less convenient to operate than the smaller, compact and much less expensive units described above to be in the first category. This second category of units includes a power steering fluid exchanger disclosed by Dixon et al in U.S. Pat. Nos. 5,806,629 and 5,583,068. This unit is connected to communicate fluidly with the power steering system's low side positive pressure discharge hose to receive used fluid there from, and is connected to communicate with the power steering pump's negative pressure or suction hose to deliver fresh fluid thereto. In order for the fluid exchange to be instituted this device must be connected to the vehicle's battery so that the unit can be activated by the operator closing an electrical switch to institute the fluid exchange which is a drawback. This unit, as do all the units in this second category of units, requires its own onboard pump to deliver fresh fluid into the power steering system. In this example, the Dixon et al device uses the used fluid flow from the pump of the power steering system to power the onboard fresh fluid pump. The need for a power steering fluid exchanger to have its own onboard pump adds significantly to the cost of the unit. In the power steering fluid changer depicted in U.S. Pat. Nos. 5,806,629 and 5,583,068, the most important function is to provide a pumping means which controls both the used fluid flow and the fresh fluid flow to be approximately equivalent in rate and volume. In these patents, the power steering fluid changer uses a positive displacement fresh fluid pump which is powered by the discharge pressure of the pump of the power steering system. Harnessing the used fluid flow from a vehicular hydraulic circuit's own pump to power a fluid exchanger's fresh fluid positive displacement pump was a novel concept first disclosed by Viken in U.S. Pat. No. 5,318,080 which related to exchanging the fluid of an automatic transmission. Power steering system fluid exchange units based on this principal are typically expensive not only because of the size of the case required, but their complexity makes the cost of manufacturing an exchanger with a positive displacement fresh fluid pump which harnesses the power of the power steering pump quite substantial. When the unit's fresh fluid supply in the power steering fluid changer depicted in U.S. Pat. Nos. 5,806,629 and 5,583,068, becomes depleted, an electrical float switch opens which then in turn deactivates the electrical solenoid of a three-way hydraulic valve to stop the fluid exchange and to shift the unit back to its original flush mode of operation which is a default closed loop circulation allowing the pump of the power steering system to circulate fluid from its discharge port back to its inlet port. Also disclosed in the Dixon et al U.S. Pat. No. 5,806,629 is a suggestion for an alternative embodiment which requires no electrical power for its operation by replacing the solenoid operated valve with a manually actuated valve that requires close operator attention to manually revert the machine from exchange mode to flush mode when delivery of the new ATF into the transmission is completed. It is also suggested that the manually actuated three-way valve can be spring loaded and manually latched into place by the service technician to remain in its exchange-mode position until a dropping float could then release a triggering device to release the spring loaded three way valve to return under spring power to its default flush mode of operation. Dixon et neither suggested or disclosed the use a three-way valve that is directly and responsively controlled by an attached float as it freely rises or falls in the fresh fluid reservoir in response to the fluid level as is disclosed in the preferred embodiment of this instant invention. The devices of this second category, the larger more expensive units that actually exchange fluid without just mixing it in the power steering reservoir, are expensive to manufacture because they require costly electric solenoid operated valves which need electrical power. The need remains for a small, compact, lightweight, easily portable power steering fluid exchanger which does not require electrical power, does not require one or more of its own fresh fluid delivery pump(s) to operate, and does not require a costly automatic fluid flow control mechanism to approximately match the fresh and used fluid flow rates and volumes. Both the first and second categories of devices, the less expensive and the more expensive, typically require connection to the vehicle's battery or electrical system in order to operate. It is desirable for a service center to acquire a power steering fluid exchanger which does not require connection to the vehicle's electrical system for a number of reasons. First, having to make connection to vehicle's battery requires the use of connection wires which can make contact with moving parts in the engine compartment if wrongly positioned or moved during the fluid exchange. Second, many currently manufactured vehicles have sophisticated onboard diagnostic computer systems (OBD systems) which can sense voltage changes, voltage spikes, and anomalies in the vehicle's electric system and which will then record a fault code. If the exchanger's wires are not securely connected to the battery or electrical system of the vehicle a spark may be generated or if a short develops in the exchanger's wiring, either of these occurrences can trigger a warning code in the vehicle's computer which may result in the vehicle's computer directing the vehicle to operate in a special default mode. There have been articles published in the automotive trade literature predicting that vehicles manufactured in the future will be increasingly dependent on even more sophisticated onboard diagnostic computer systems (OBD systems). It is expected that these advanced OBD systems may be increasingly sensitive to unnecessary, non-operational current fluctuations, which may cause false error codes or cause the vehicle to assume a default mode of operation which lowers the gas mileage of the vehicle until the computer system is reset, which typically requires the vehicle to be driven for a period of time. For example, some Chrysler OBD systems are so sensitive that if a single spark plug or spark plug wire fails, the vehicle will be placed in a default operational mode with the automatic transmission operable in second gear only. Third, there have articles published in the automotive trade literature which predict that in the not too distant future automotive manufacturers will likely utilize new, higher voltage systems accompanied by newly designed high output combination alternator/starters and electrically powered air conditioners, brakes and/or suspensions. If these expected voltage increases are implemented service equipment which has been manufactured for 12 volts direct current (DC) will become obsolete and unusable unless it is modified to accept these higher voltages. If it has to be modified or replaced this will be an added and undesirable expense. Another type of power steering fluid changer which has been available in the past has been the unit depicted by Baylor et al in U.S. Pat. No. 5,015,301. This device is operated with the vehicle's engine off and the power steering pump inoperative. This device consists of a tank with a bladder type “pusher” which holds fresh fluid on the top side and receives compressed air as a powering medium on the lower side. The need for access to shop air can limit the service area used to provide the fluid exchange. Once this device of Baylor et al is connected to the power steering system, compressed air is then provided to the lower side of the diaphragm “pusher” to pressurize the fresh fluid to flow into and through the low pressure inlet hose (or conduit) of the power steering pump to then flow through the rest of the power steering system and then finally out of the low pressure reservoir return hose (or conduit) to the unit's open used fluid receiver. The Baylor et al patent shows only a remotely arranged reservoir style power steering system in its figures and apparently neglects to illustrate, describe and explain how the unit would be specifically connected to service the more traditional type of power steering system which has a combination reservoir/pump assembly. The Baylor et al patent teaches that this unit is operated only with the engine of the vehicle off and the pump of the power steering system not operating. The unit is normally operated in two separate procedures, the first time to infuse a fresh flushing mixture into the power steering system. The unit is then disconnected temporarily while the vehicle's engine is run for awhile to therefore circulate the fluid flushing mixture through the power steering system to dissolve varnish buildup and contaminants. The engine is then turned off and the unit is reconnected and operated a second time to flush the power steering system, this time only using fresh power steering fluid with perhaps an additive package. This particular unit is somewhat bulky and cumbersome to use, and due to the multiple steps involved, takes an unnecessarily long time to operate. In addition it seems likely that the use of such a flushing procedure without the power steering pump operative would not be as effective in removing all the used fluid as would a fluid exchange procedure accomplished with the power steering pump operative. These drawbacks prevent it from being a preferred option for those service centers who want a unit that is compact, self contained with no need for compressed shop air or connection to a source of electrical power, simple to operate and capable of exchanging a high proportion of used fluid for fresh fluid in a relatively short period of time while the power steering pump is operative. The Graham U.S. Pat. No. 5,971,021 discloses a method for filling a new and empty power steering system or other hydraulic circuit with fresh fluid by using a specialized valve. Graham also suggests that this method can be used to exchange used fluid for fresh fluid as a maintenance procedure. It is not known if this product is commercially available at this time. This patent appears to teach the connection of a specially designed valve device midstream into the high pressure conduit of a fluid system, such as a power steering system or cooling system for the purpose of filling that fluid system for the first time. This methods teaches pressurizing a fluid and then injecting that pressurized fluid through this specialized valve which has been installed into a two sided conduit. A substantially unidirectional flow pattern through a selected side of the intercepted conduit is established by injecting most of that pressurized fluid through the valve into that selected side of the intercepted conduit while allowing a small portion of that pressurized fresh fluid to be injected into the other side of that conduit by leaking around the slide of the specialized valve. As the pressurized fresh fluid is injected into the power steering system air contained in the system is also simultaneously driven out. This valve and its use are depicted as being particularly applicable to power steering fluid systems and one figure illustrates this valve as being interconnected to such a system between the power steering pump and “gearbox” midstream in the pump's high pressure outlet conduit, with the valve arranged to discharge its pressurized fluid in a substantially unidirectional flow in the direction of the conduit which leads to the gearbox. After this valve is properly connected to a new but empty power steering system, a pre-pressurized source of fresh fluid is then connected to this valve which in turn causes the valve to operate to inject pressurized fresh power steering fluid in a substantially unidirectional flow to fill the system and to displace air out of the system, with the capability of simultaneously allowing some fluid to also be infused upstream, thus displacing the air from two directions. This pressurized fresh fluid remains pressurized as it flows into and through the steering mechanism. It is also taught that this valve may be connected to a used power steering system which is filled with used fluid for the purpose of exchanging its used fluid for fresh fluid as a maintenance procedure. Installing this valve as depicted for routine power steering fluid exchanges would be somewhat difficult task in and of itself due to the tendency for the power steering pump's high pressure conduit (or hose) to have connections which are often be corroded and typically somewhat difficult to reach and disconnect. It appears that no mention is made of whether the vehicle's engine is operative while the procedure is enacted. However, the suggested positioning at which the valve is connected as apparently disclosed in Graham's patent is downstream from the pump's outlet port, and therefore it is assumed that the power steering system must be inoperative while a new fluid fill or a fluid exchange is instituted, since operating the pump with the valve downstream would obstruct the output flow of the pump and perhaps could damage the power steering pump if it's relief valve was malfunctioning or its setting was too high. Unless the valve was purchased by customer and permanently installed, at each fluid exchange service, the valve would have to be installed and used after disconnecting the power steering systems' high pressure hose (conduit). After the fluid exchange was completed the high pressure line would have to be disconnected from the valve and reconnected in its proper configuration to the power steering pump. It appears then that use of this valve and method would be too slow and unduly cumbersome to be practical for use at most vehicle service centers as a regular power steering maintenance procedure. The Sangret U.S. Pat. No. 5,664,416 discloses a new and improved method for filling a new power steering assembly with fluid for the first time on an auto assembly line. This patent discloses a method for pumping fluid from a bulk holding tank into the power steering system's reservoir to circulate in the power steering system with the engine operative under power of the power steering pump, after which that fluid is then discharged and returned to the bulk holding tank for redundant circulation back into and through the power steering system. When a new power steering system is filled for the first time air typically becomes entrained in the power steering fluid and this method offers a solution for remove that entrained air. The patent discloses that air entrained in a power steering system may cause unwanted noise and/or vibration which may be annoying to the driver who first operates the vehicle after the filling of the power steering system. This method teaches that redundant circulation of fluid in and out of the bulk holding tank is instituted until the power steering system is completely filled with fluid and the entrained air has been removed. This method teaches the placing of a special connector assembly in the filler opening of a certain very select configuration of remotely arranged power steering reservoir, a reservoir which has its low pressure fluid return port directly placed below and on center of the filler neck of the reservoir. This connector assembly takes the position of the reservoir cap type and has both a fresh fluid delivery conduit and a used fluid receiving or discharge conduit passing through it into the filler opening of this select type of remote power steering system reservoir. This adapter is pushed into the filler neck of the reservoir which inserts its used fluid receiving conduit matingly down and into the used fluid return port of the reservoir which is directly below and on center to the filler neck of the reservoir. This used fluid receiving conduit then receives fluid which is discharged from the power steering pump being returned to the reservoir. The fresh fluid delivery conduit of the connector assembly is shorter than the discharge conduit and does not connect with the supply conduit port of the reservoir which is located off center of the reservoir, but it discharges fresh fluid into the reservoir after being pumped out of a bulk holding tank which is sealed and provided with a vacuum pump for extracting entrained air out of the fluid. The holding tank is shown with its own fresh fluid delivery pump for delivery fresh fluid through the special adapter into the power steering reservoir. The patent does not disclose using the power steering pump's low pressure inlet port side or its positive pressure outlet side for powering the pumping of fluid into and through the power steering system redundantly, even though the engine is running to render the power steering pump operative. The fluid discharged by the pump is then delivered through the connector assembly and into the bulk holding tank which is actually a large additional fluid reservoir which both provides supply fluid for delivery into the power steering system and receives the fluid discharged from the power steering system. The method does not disclose or teach the exchange of used fluid for fresh fluid and is apparently limited to charging a power steering system for the first time while removing the air that inevitably becomes entrained. The method of Sangret discloses an arrangement of one electrically operated valve and two electrically operated pumps which are simultaneously activated by an electronic control unit which energizes an inductive coil when the vehicle's engine is started. The valve is a flow control valve which stops fluid flow out of the bulk holding tank when the engine is turned off which inactivates the valve, and allows fluid flow out of the bulk holding tank and into the power steering reservoir when activated by the engine running. One pump is a vacuum pump which is connected to a port near the top of the bulk tank and provides enough low pressure to evacuate any air which has become entrained in the power steering fluid after it returns to the holding tank as the power steering system is filled for the first time. The other pump is a fluid delivery pump, referred to as a flow charge pump, which when activated by the electronic control unit will pump fluid from the bulk holding tank into the power steering reservoir where the low pressure provided by the power steering pump then delivers that fluid into the conduit supplying the power steering pump. The flow charge pump appears to be necessary for two reasons. First, the patent depicts the fluid supply port at the bottom of the bulk holding tank to be at a level below that of the connector assembly, and the negative pressure provided by the power steering pump is not likely to be great enough to pump the fluid from the bulk holding tank without assistance by an auxiliary pump. Second, the low pressure provided by the vacuum pump will likely conflict with the low pressure provided by the power steering pump which would inhibit the flow of the fresh fluid into the conduit supplying the power steering pump. The special connector assembly which is inserted into the filler neck of the power steering reservoir is shown to have a set of three O'rings for sealing but is not shown to have a positively engaging set of tab locks like many power steering caps. It can be assumed that the connector is held in place only by sidewall friction between the cap, its O'rings and the filler neck of the reservoir and any low pressure provided by the power steering pump through that pump's inlet port. One potential drawback to the use of this method of filling a new power steering system with fresh fluid for the first time is that the flow charge pump must have a delivery output pressure great enough to overcome the low pressure provided by the vacuum pump but not so great as to deliver fluid at a greater flow rate to the reservoir than the power steering pump will accept it. If this occurs pressure can build up inside the reservoir which can disrupt the sealing of the connector into the reservoir filler neck and perhaps can cause leakage of fluid and displacement of the connector up and out of position in the filler neck. The Brown U.S. Pat. No. 5,291,968 discloses an “Apparatus and Method for Changing Automatic Transmission Fluid in Motor Vehicles” and does not address changing fluid in power steering systems. It discloses the method of removing the pan of a transmission to access the intake port of the suction conduit of the transmission pump to then connect a pressurized fresh fluid supply to that intake port while idling the engine to operate the transmission and while providing a pan underneath the transmission to receive the fluid discharged from the transmission's pump. Because the fresh fluid reservoir of the apparatus is at floor level, and since the low pressure provided by the transmission's pump is inadequate to deliver the fresh fluid from floor level up and into to the port of that suction conduit and into the transmission, the unit requires its own on-board pump to deliver fresh fluid up to the port of the suction conduit of the transmission pump. In addition, this method apparently requires close monitoring by the operator since the engine must be turned off as soon as the fresh fluid supply of the fluid exchanger is depleted to prevent air from being pumped into the transmission. The Matta U.S. Pat. No. 4,342,328 depicts a two stage float valve which is connected to a suction tube. The purpose of this float valve is to close off a fuel tank from the suction tube when the fuel tank starts to run dry and fuel is being drawn from another tank. This float valve is configured to be resistant to closing prematurely from the effect of the suction provided by the suction tube. This is accomplished by providing an inner poppet which equalizes the negative pressure of the suction tube to both sides of the valve's primary seal thereby neutralizing the effects of the suction on the valve's primary seal. This allows the use of a smaller float than would otherwise be necessary and prevents the negative pressure provided from the suction tube from adversely affecting the operation of the valve. This patent disclosed the problem of establishing an air tight seal when a fluid supply is diminished and the importance of preventing low pressure or suction from prematurely closing the valve. The float valve disclosed in this patent by Matta is a fluid supply valve only and does not control any exchange of fluids. The Colvin, et al. U.S. Pat. No. 6,477,886 discloses a test apparatus for measuring the amount of air entrained in the fluid of a power steering system. The apparatus also includes a vacuum pump for drawing air out of the power steering pump. It disclosed that air and other gases entrained in the power steering fluid may result in excessive noise during the operation of the pump and may include whining and hissing, and that these noises may be similar to noises caused by improperly functioning components. It is disclosed that it is useful to be able to use a measurement device to indicate if entrained air is significant enough to be causing such noises or if not that the power steering system is damaged. This lends further credence to the importance of not allowing air to become entrained by a power steering fluid exchanger when exchanging the fluid of a power steering system since it may mask the sounds created by damaged components. SUMMARY OF THE INVENTION The invention is a light, very compact, portable, easy to position, easy to connect, and easy to operate, automatic power steering fluid exchanger with a fresh fluid reservoir, a used fluid receiver, and a fluid control valve which directs the operation of the fluid exchanger and is itself operated by a float in the fresh fluid reservoir. The float which operates the mechanical/hydraulic fluid control valve is a mechanical float, while the float controlling the electrical/hydraulic is an electric float switch. In the preferred embodiment negative pressure provided by the power steering pump is used to assist in the operation of the fluid control valve. In one alternative mechanical/hydraulic embodiment positive pressure provided by the power steering pump is used to assist in the operation of the fluid control valve. In another alternative mechanical/hydraulic embodiment both negative pressure and positive pressure provided by the power steering pump are used to assist in the operation of the fluid control valve. The used fluid receiver of the fluid exchanger is emptied of used fluid from the prior fluid exchange. The fluid exchanger's fresh fluid reservoir is filled with an adequate volume of fresh fluid which causes the float in the fresh fluid reservoir to rise to its upward position. The power steering system's fluid circuit is opened to divide and isolate the power steering pump's inlet port or low pressure side from its outlet port or pressure, discharge side. The fluid exchanger is connected to the power steering system using suitable adapters after either removing the power steering reservoir from the power steering system or converting it to be essentially vent free and filled with fluid. The exchanger's fresh fluid exchange hose is connected to arrange its fresh fluid reservoir to supply the power steering pump's inlet port, and the exchanger's used fluid exchange hose is connected to arrange its used fluid receiver to receive used fluid discharged from the power steering pump's outlet port. The vehicle's engine is started which renders the power steering pump operative which causes the fluid exchanger to automatically exchange its fresh fluid for the used fluid of the power steering system. The fresh fluid delivered from the fluid exchanger into the power steering system flows at approximately the same equivalent rate and volume of flow as the power steering system's used fluid is discharged into the exchanger's used fluid receiver. When the fresh fluid supply becomes depleted, the float in the fresh fluid reservoir moves to its downward position which establishes a closed fluid circulation circuit for the power steering pump. This closed fluid circulation circuit is characterized by the establishment of essentially vent free fluid communication between the pump's outlet and inlet ports with no communication between the exchanger's fresh fluid reservoir and the power steering pump's inlet port, and with no communication between the used fluid receiver and the pump's outlet port. If an electrical/hydraulic fluid control valve is used a float switch be alternatively positioned in the used fluid receiver to sense when it is full to inversely control the fluid control valve to establish a closed fluid circulation circuit. This may be done alone or in coordination with an electric float switch also used in the fresh fluid reservoir to sense when the fresh fluid supply is depleted. In the preferred embodiment and the other alternative embodiment herein, a single float is positioned in the fresh fluid reservoir since it was found in experimentation to be more practical than using a single float in the used fluid receiver, especially when the operator forgets to fill the fresh fluid reservoir with fresh fluid and connects the exchanger and then starts the vehicle's engine, which quickly infuses and entrains air in the fluid of the power steering system from an empty fresh fluid reservoir. One object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which provides a light weight, compact, easily portable unit which can be positioned in a convenient location. The fluid exchanger should have a small footprint and contains a compact fresh fluid supply reservoir which is large enough to provide a virtually total or nearly total exchange of the fresh fluid of the fluid exchanger for the used fluid of most or nearly most vehicular power steering systems seen in automotive service and lube centers. Another object of the invention is to provide an apparatus and method for exchanging the fluid of a power steering system which is relatively inexpensive to purchase while being comparable in function to other more expensive fluid exchangers which actually exchange the used fluid of the power steering system for the fresh fluid of the fluid exchanger rather than just mixing and diluting the used fluid with fresh fluid within in the power steering reservoir, as is used in some inexpensive and relatively ineffective power steering fluid exchangers on the market today. Since time is equivalent to cost in the vehicular maintenance industry, another object of the invention is to provide an apparatus and method which provides a rapid exchange of the used fluid of a power steering system with fresh fluid. Another object of the invention is to provide an apparatus for exchanging the fluid of a power steering system which is easy and quick to connect and operate, one which requires minimal training for new service technicians. The apparatus and method will provide for easy connection to both types of power steering systems layouts, the type of power steering system layout where the reservoir is combined with the pump and also the type of power steering system layout which has a fluid reservoir remotely positioned above and away from the power steering pump. Another object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which provides for isolated delivery of fresh and used fluid through two separate respective conduits, with one connected to deliver fresh fluid from the fluid exchanger's fresh fluid reservoir to the inlet side conduit of the power steering pump and the other to deliver used fluid delivered from the power steering pump to the fluid exchanger's used fluid receiver. Another object of the invention is to provide an apparatus and method which will exchange a significantly higher proportion of fresh fluid for used fluid than the first or inexpensive category of exchangers which are exemplified by the use of two pumps which mix fresh fluid and used fluid for partial dilution within the power steering reservoir through its filler neck. Another object of the invention is to provide an apparatus and method for exchanging the used fluid of a power steering system for fresh fluid while the vehicle's engine idles without requiring any connection to a power source which is not inside the fluid exchanger such as having to connect the exchanger to the vehicle's battery or electrical system, to a 115 volt or 220 volt AC current source or to the service center's compressed air supply. This can be accomplished by powering the fluid exchanger solely by the low pressure provided by the power steering pump in coordination with atmospheric pressure and positioning the fluid exchanger above the power steering pump at the same level or somewhat higher than the power steering reservoir. A power pack contained in the exchanger may be provided to power a float switch, a fluid control valve, and other indicators such as a warning tone and a bright red, blinking LED alert. Another object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which automatically starts exchanging fluid when the vehicle is started and allows the operator to take his time turning off the engine after the completion of the fluid exchange with no obstruction or interruption of flow into and out of the power steering pump. The fluid exchanger will automatically stop exchanging fluid when its fresh fluid reservoir becomes depleted while simultaneously allowing the power steering pump to freely circulate fluid from its outlet port back to its inlet port in a closed fluid circulation circuit. The fluid exchanger's operation will be automatically controlled by a fluid control valve which in turn is controlled by a float positioned in the fresh fluid reservoir, and this float will be directly and responsively controlled by the rising or falling of the fresh fluid level without the required use of any springs or manually spring loaded latches. Use of a float operated fluid control valve allows the fluid exchanger to automatically shift from exchanging fluid to circulating fluid in a closed fluid circulation circuit and back again when the fresh fluid reservoir is refilled for the next fluid exchange. Another object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which automatically delivers fresh fluid and used fluid at approximately the same rates of flow and in the same approximate volumes. If the rates of flow and the volumes of flow of the fresh and used fluid are not approximately equivalent, significant differences can result in differences in the volumes of fresh and used fluid delivered at any one time, creating a situation of too much fresh fluid or used fluid delivered in comparison to one another with the resulting fluid overflow or fluid starvation of the power steering system. Another object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which does not infuse air into the power steering system during the exchange of used fluid for fresh or after the fluid exchange. Infusion of air is undesirable since it quickly becomes entrained and tends to expand the volume of the fluid, resulting in fluid starvation of the fluid circuit's pump, loss of effective lubrication and diminished capacity of the fluid to transmit power. This entrainment of air and resulting loss of fluid power capacity is typically accompanied by significant noise in the power steering system and significant reduction of ability to steer the vehicle. Unabated, such a condition can damage the power steering system. If is does not damage the power steering system, the loud noise can certainly alarm the vehicle's owner and the loss of full steering power can pose a safety issue if not quickly remedied. Therefore, if this condition occurs, the vehicle should not leave the service center until it is resolved. Resolving this condition adds additional complexity and time to the procedure since it may take a period of minutes for the entrained air to release from the fluid while the engine idles. When air releases from the fluid, the fluid volume lessens, thus often requiring additional or multiple topping off of fluid. This delays the completion of the fluid exchange procedure and can project an undesirable image to the customer who stays in or near his vehicle while having the power steering fluid is exchanged and who hears the resulting loud noises in their power steering system from the entrained air and witnesses the efforts of the service technician to remedy the problem. Experimentation by the inventors has shown that development of a purely mechanical/hydraulic float operated fluid control valve without electrical activation required meeting some unique challenges in order to develop a valve which will smoothly shift from a fluid exchanging mode of operation to a second mode of operation which allows the power steering system to circulate its fluid in a closed fluid circulation circuit through the fluid exchanger and the power steering system without allowing air to enter the fluid. When the fresh fluid supply has become depleted, an effective seal must be established between the fresh fluid reservoir and the fluid control valve or air will be pumped into the power steering system from the fresh fluid reservoir if the engine of the vehicle is allowed to continue running. It was also discovered that the tighter the sealing provided to valve slide where it enters the fresh fluid reservoir, the more effectively it sealed, but also the more difficult it was for the slide to move up and down in the valve body. Without the serendipitous discovery of the effective pressure assisted sealing methodology herein disclosed, effective sealing provided to the valve slide typically caused the valve slide to either move sluggishly or become stuck and to stay in its fluid exchange position even when the fresh fluid supply was depleted. Attempts to increase the size of the float to allow greater weight to be added to the float as a single solution to this problem were unsuccessful. An effective solution to the sealing problem was thus conceived during the process of experimentation. It was determined that the best solution was to provide and maintain an effective seal for the fluid control valve from the fresh fluid reservoir only upon depletion of the fresh fluid supply, and this could be accomplished by selectively harnessing and utilizing the low pressure provided by the power steering pump through the fluid exchanger's fresh fluid supply hose to establish and hold an effective seal. As long as this low pressure is used to provide and maintain a seal between the valve slide and the fresh fluid reservoir only when the fresh fluid supply became depleted, the valve slide is able to freely move to its lower position to establish a closed fluid circulation circuit for the power steering pump without allowing the infusion of air which quickly become entrained in the fluid. Any infusion of fresh fluid through or around the slide during the fluid exchange is acceptable since the slide is used as a fresh fluid port in the preferred embodiment. It was also discovered that the positive and negative pressures provided by the power steering pump could be harnessed and utilized to assist a mechanical/hydraulic float operated valve in shifting to its closed fluid circulation mode when the fresh fluid supply became depleted. It was also discovered that eliminating the fresh fluid supply port as a separate entity in the bottom of the fresh fluid reservoir and combining it internally with the control valve slide was helpful in preventing air infusion from an empty fresh fluid reservoir. Another critical issue which was resolved by the inventors in experimentation was the developing and implementation of a method to effectively seal off the used fluid receiver from the closed fluid circulation circuit when it was established and maintained by the fluid control valve. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts what can be referred to as a traditionally configured reservoir pump combination type power steering system. FIG. 2 depicts what can be referred to as a more modern remote fluid reservoir type power steering system which has its fluid reservoir arranged at a remote location. FIG. 3 depicts the preferred embodiment of the invention. FIG. 4 depicts the detailed construction of a mechanical/hydraulic fluid control valve of the preferred embodiment of FIG. 3 and its parts arrangement showing the valve operating with its slide in the upward position. FIG. 5 depicts the detailed construction of the mechanical/hydraulic fluid control valve of the preferred embodiment of FIG. 3 and its parts arrangement showing the valve operating with its slide in the downward position. FIG. 6 depicts an exploded, perspective view of the mechanical/hydraulic float operated pressure assisted fluid control valve of the preferred embodiment of FIG. 3 and its parts arrangement. FIG. 7 depicts the fluid exchanger in proper connective arrangement to a power steering system of the traditional reservoir-pump combination type. FIG. 8 depicts the special set of adapters which is used to provide the proper connective arrangement of the fluid exchanger as shown in FIG. 7. FIG. 9 depicts the invention in proper connective arrangement to a power steering system of the remotely positioned reservoir type. FIG. 10 depicts the special set of adapters which is used to provide quick connection to the fluid exchanger as shown in FIG. 9. FIG. 11 depicts a specific style of remote reservoir power steering system seen in certain late model Ford vehicles. FIG. 12 depicts the remote reservoir system of FIG. 11 with a set of special adapters connected to provide quick connection to the fluid exchange device. FIG. 13 depicts a specific style of reservoir/pump combination power steering system seen in certain late model Chrysler vehicles. FIG. 14 depicts the remote reservoir system of FIG. 13 with a special set of adapters installed to provide quick connection to the fluid exchange device. FIG. 15 depicts the remote reservoir system of FIG. 13 with a set of special adapters installed to provide an alternative quick connection to the fluid exchange device. FIG. 16 depicts the invention in an embodiment of an alternative positive pressure assisted mechanical/hydraulic fluid control valve and its parts arrangement showing the valve operating with its slide in the upper position. FIG. 17 depicts the embodiment of FIG. 16 with its mechanical/hydraulic fluid control valve operating with its slide in the lower position. FIG. 18 depicts an exploded, perspective view of the embodiment of FIG. 16. FIG. 19 depicts the detailed construction of a mechanical/hydraulic fluid control valve of an alternative embodiment and its parts arrangement showing the valve operating with its slide in the upward position. FIG. 20 depicts the detailed construction of a mechanical/hydraulic fluid control valve of an alternative embodiment and its parts arrangement showing the valve operating with its slide in the downward position. FIG. 21 depicts the detailed construction of an alternative and basic embodiment and its parts arrangement which features a simple, economical fluid control valve. FIG. 22 depicts the detailed construction an alternative embodiment and its parts arrangement which features an electrical/hydraulic fluid control valve which features the use of a two-position two-way solenoid valve. FIG. 23 depicts the detailed construction of an alternative embodiment and its parts arrangement which features an electrical/hydraulic fluid control valve with a two-position three-way solenoid valve. FIG. 24 depicts the detailed construction of an alternative embodiment and its parts arrangement which features an electrical/hydraulic fluid control valve with a two-position four-way solenoid valve. FIG. 25 depicts the detailed construction of an alternative embodiment which is based on the modified embodiment of FIG. 24. FIG. 26 depicts a hook bracket which can be used to hang the fluid exchanger from the raised of the vehicle being serviced. FIG. 27 depicts an adjustable hood rod which can be used to hold the hood open of the vehicle being serviced if the vehicle does not have a hood rod and the technician wants to hang the fluid exchanger from the hood. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 depicts one of the two basic types of power steering systems found in vehicles today, commonly referred to as a traditionally configured power steering system which has its fluid reservoir arranged integral to the power steering pump as a reservoir-pump combination assembly. With this configuration the pump supply conduit from the reservoir to the intake port of the pump is very short in length and is hidden from view inside the reservoir-pump combination assembly. Typically a power assisted steering gear mechanism accompanies this configuration. In years past the reservoir's walls were typically constructed of non-transparent metal, but more recently there is a trend toward constructing the reservoir of either translucent or non-translucent plastic. The power steering system of FIG. 1 has a reservoir 100 arranged integral to a power steering pump 105 to form a combination reservoir-pump assembly 192. Reservoir 100 contains a fluid 101. A reservoir outlet conduit 106 carries fluid 101 from reservoir 100 to an inlet port 107 of pump 105. Reservoir outlet conduit 106 is very short in length and is hidden from view inside combination reservoir-pump assembly 192. Typically, this configuration includes a steering gear mechanism 112. Reservoir 100 is constructed of metal. A pressure conduit 110 connects an outlet port 109 of pump 105 to an inlet port 111 of steering gear mechanism 112, which is power assisted by the pressurized fluid provided by pump 105 through pressure conduit 110. The fluid in pressure conduit 110 has higher pressure than the fluid located anywhere else in the power steering system and this pressurized fluid is the working fluid which provides the power to assist the driver in steering the vehicle. Thus fluid 101 is pressurized by pump 105 to provide power to do the hydraulic work required to make the vehicle easier to steer by the driver. Steering gear mechanism 112 has a fluid return conduit 114 with al hose end 115 attached by a ferrule 120 which is crimped. Fluid return conduit 114 is connected to an outlet port 113 of steering gear mechanism 112. Hose end 115 is connected to a reservoir return port 116 and sealingly secured by a hose clamp 117, which is a stainless steel gear drive type. Power is provided to pump 105 by a belt 119 which is rotated around a pulley 118 under power of the engine of the vehicle (not shown). Reservoir 100 has a filler neck 102 which receives and holds a cap 103 which is vented to the atmosphere. Cap 103 has a dipstick 104 integral to its bottom side. Fluid 101 is delivered from reservoir 100 under power of pump 105 to be circulated out of port 109 through pressure conduit 110 into port 111, through steering gear mechanism 112, out of outlet port 113, through conduit 114 and hose 115, into and through port 116 to be deposited back into reservoir 100 for redundant delivery and circulation by pump 105. FIG. 2 depicts the second of two basic types of power steering systems found in vehicles today, commonly referred to as a more modern power steering system which has its fluid reservoir arranged at a remote location above the power steering pump with the pump supply conduit and the low pressure outlet conduit from the power assisted steering mechanism typically visible and accessible, with each conduit connected to one of the two ports of the remote reservoir. A power assisted rack and pinion steering mechanism typically accompanies this second type of system. As with the more traditionally configured system having a reservoir-pump combination, the low pressure fluid return conduit from the power assisted steering mechanism is connected to the return port of the reservoir. In addition the fluid reservoir is typically translucent, allowing one to note the fluid level through the wall of the reservoir at designated marks on the wall. This power steering system has a fluid reservoir 200 arranged at a remote location above a power steering pump 205 which contains a fluid 201. Reservoir 200 has two visible and typically accessible ports, a reservoir outlet port 206 and a reservoir return port 216. A pump supply hose 208 connects reservoir outlet port 206 to a pump inlet port 207. Pump supply hose 208 is sealingly secured to port 206 and to port 207 by a pair of hose clamp 117. A pressure conduit 210 connects a pump outlet port 209 of pump 205 to an inlet port 211 of a rack and pinion steering mechanism 212, which is power assisted by the fluid power provided by pump 205. Fluid 201 is pressurized by pump 205 to provide power to do the hydraulic work required to make the vehicle easier to steer by the driver. Rack and pinion steering mechanism 212 has a fluid return conduit 214 with a hose end 215 attached by a ferrule 120 which is crimped. Fluid return conduit 214 is connected to an outlet port 213 of rack and pinion steering mechanism 212. Hose end 215 is connected to reservoir return port 216 and sealingly secured by hose clamp 117. Power is provided to pump 205 by a belt 219 which is rotated around a pulley 218 under power of the engine of the vehicle (not shown). Reservoir 200 has a filler neck 202 which receives and holds a cap 203 which is vented to the atmosphere. In normal operation the power steering system is constructed and arranged for fluid 201 to be delivered from reservoir 200 through port 206, through pump supply hose 208 into pump inlet port 207 under power of pump 205 to be circulated out of pump outlet port 209 into and through pressure conduit 210 and through inlet port 211, through rack and pinion steering assembly 212, out of outlet port 213, through fluid return conduit 214 and hose end 215, and into and through reservoir return port 216 to be deposited into reservoir 200 for redundant delivery and circulation by pump 205. FIG. 3 depicts the invention in its preferred embodiment, a power steering fluid exchanger 325 which is a light, very compact, portable, easy to position, easy to connect and operate, and is automatic. Power steering fluid exchanger 325 has a fresh fluid reservoir 328, a used fluid receiver 326, and a fluid control valve 457 which is operated by a float 472. The fluid control valve 457 controls the operation of the fluid exchanger 325 and is directly operated by float 472 which is positioned in fresh fluid reservoir 328 and is buoyant in a fresh fluid 329 which is contained therein. Float 472 is responsive to the increasing or decreasing level of fresh fluid 329 contained in fresh fluid reservoir 328 and operates the fluid control valve 457. Power steering fluid exchanger 325, which is in this embodiment is constructed of translucent high density polyethylene plastic molded in three separate parts which snap fit together and are further secured by screws (not shown), and which are fluorinated for resistance to discoloration and damage by oil. Fluid exchanger 325 can however, be constructed of a wide range of other plastics and materials, including welded sheet metal, deep drawn metal, or cast aluminum with vertically running sight glasses. In this preferred embodiment no fluid level sight glasses for the fresh fluid reservoir 328 or the used fluid receiver 326 are necessary since the plastic used is translucent and allows the operator to view the used and fresh fluid levels. Used fluid receiver 326 receives and holds a used fluid 327. Used fluid receiver 326 and fresh fluid reservoir 328 are molded together as an integral part of fluid exchanger 325 which is configured to accept at its top in snap fit fashion, a top cover piece 330 which is a one piece molded plastic part which sealingly covers and isolates both used fluid receiver 326 and fresh fluid reservoir 328 after being snap-fitted and glued as well screwed in place (screws not shown). Fluid exchanger 325 has a post 336 and a post 338 which are integrally molded into it at each side, and which each accept the hole at each end of a handle 339 which is flexible, is constructed of molded nylon plastic, and which is secured to posts 336 and 338 by a retainer cap 335 and a retainer cap 337 which are secured into posts 336 and 338 by screws. The fresh fluid reservoir 328 hold approximately 3½ quarts of fresh fluid 329 which is approximately ½ quart less in volume than the capacity of used fluid receiver 326 which holds approximately 4 quarts of used fluid 327. This slightly larger capacity of used fluid receiver 326 compared to the fresh fluid reservoir 328 allows the operator to add fresh fluid to top off the reservoir of the power steering system being serviced before it is serviced without having the used fluid reservoir 326 overflow with fluid. This slightly smaller volume of fresh fluid reservoir 328 is accomplished by calculating the volume occupied by float 472 and then constructing the plastic mold to reduce the inside dimensions of fresh fluid reservoir 328 in comparison to used fluid reservoir 326 until the desired difference of approximately ½ quart is reached. Top cover piece 330 has a filler neck 332 which is integrally molded and which is threaded to receive a cap 333 which is well vented to allow air to enter the fresh fluid reservoir to replace fresh fluid 329 as it leaves fresh fluid reservoir 328. Top cover piece 330 has an orifice which accepts a molded plastic vent 331 in snap fit fashion and which is arranged to allow the air to move in and out of used fluid receiver 326 as used fluid 327 is emptied, and also as used fluid 327 is delivered into used fluid receiver 326. Filler neck 332 is constructed to accept and hold a strainer 334 which is constructed of cylindrically molded nylon with a sidewall and bottom end having numerous integral strainer holes of approximately 50 microns in size. Strainer 334 serves to prevent significantly sized debris from entering fresh fluid reservoir 328 which could interfere in the functioning of a fluid control valve 457 or enter the power steering system being serviced and perhaps cause a problem in the system. Fluid control valve 457 is machined from aircraft grade aluminum stock which is threaded to securely and sealingly screw into a bottom common wall 349 of fluid exchanger 325. Fluid control valve 457 has a hose barb 458 and a 90 degree hose barb 463 which are constructed to accept low pressure push-lock type hydraulic hose. Fluid control valve 457 also has a magnetically operated micro-switch 462. Fluid exchanger 325 has a skirt base 340 at its bottom side which is integrally molded as one piece with four sides and a bottom. Skirt base 340 snap fits into the top section of fluid exchanger 325 which contains both the used fluid receiver 326 and the fresh fluid reservoir 328. Skirt base 340 is further secured by screws (not shown). Skirt base 340 has four integral orifices at each corner of its bottom which securely accept a set of four footpads 341 which is in this embodiment are comprised of molded, soft, nitrile type rubber (only the front side two are shown). The fresh fluid reservoir 328 and the used fluid receiver 326 share bottom common wall 349 which has four threaded ports provided to it. Common wall 349 is thick enough to provide adequate rigidity and strength to allow its four threaded ports to receive and securely hold four separate threaded components. The technology exists to for brass, steel or alloy threaded collars to be easily molded into the plastic comprising common wall 349 to provide extra strength to the four threaded orifices if desired, but if the plastic is thick and strong enough as in this case, that is not necessary. Two of these components screwed into and sealingly secured to a pair of orifices of bottom common wall 349 are a 45 degree connector 344 arranged to communicate with the used fluid receiver 326 and a 45 degree connector 347 arranged to communicate with the fresh fluid reservoir 328. A ball valve 342 which has a valve operating lever 343 is connected to the 45 degree connector 344 to allow used fluid 327 to be drained from used fluid reservoir 326. A ball valve 345 which has a valve operating lever 346 and is connected to 45 degree connector 347 to allow fresh fluid 329 to be drained from used fluid receiver 328. A check valve 350 is brass and is threaded at its upper end and is screwed into and sealingly secured into one of the four threaded orifices, the one located in the right side of bottom common wall 349 which provides access to used fluid receiver 326. Check valve 350 has a female thread at its lower end to receive a street tee 351 which is brass. Street tee 351 has a middle placed female thread which receives a hose barb 352 and an end placed female thread which receives a 90 degree hose barb 353. Both hose barb 352 and hose barb 458 are pushlock type hose barbs which must receive pushlock type hose. This method of sealingly securing hose is well known to those of average skill in the art. The 90 degree hose barb 463 and 90 degree hose barb 353 are not pushlock but require the use of crimped ferrules to sealingly secure the hose sections which are sealingly attached, and this method of connecting hose to ports is also well known to those of average skill in the art. Used fluid hose 356 which is a push lock type ⅜ inch internal diameter hose is connected at one end and to hose barb 352 at the other end to hose barb 458. In this embodiment, used fluid hose 356 is a piece of very durable, high quality pushlock type hose, in this case Parker 811 hose of ⅜ inch internal diameter which is constructed with materials resistant to power steering fluids of all varieties. The fluid exchanger assembly 325 has two fluid exchange hoses, a used fluid exchange hose 354 which in this case is ⅜ inch internal diameter and comprised of a clear braided flexible plastic hose such as nylabraid® type hose. A fresh fluid exchange hose 366 which in this case is ⅝ inch internal diameter, is also comprised of a clear braided flexible plastic hose such as nylabraid® type hose or a special steel wire reinforced clear plastic hose, typically stiff enough to prevent collapse from the low pressure provided by a power steering pump, but flexible enough to position easily. Used fluid exchange hose 354 is connected at one end to hose barb 353 and at its other end to a small female quick connect 355, which in this case is a ⅜ inch non spill type. Fresh fluid exchange hose 366 is connected at one end to 90 degree hose barb 463 and at its other end to a large female quick connect 367, which in this case is a ½ inch non spill type. Fluid exchange hoses 354 and 366 are connected to their respective hose barbs and female quick connects by the use of hose barbs which require crimped ferrules (not shown). FIGS. 4-6 depict the detailed construction of a fluid control valve 457 and its parts arrangement, with FIGS. 4 & 5 showing a side view and with FIG. 6 illustrating an exploded view. All the parts of FIG. 6 are visible in FIGS. 4 & 5 with the exception of an O'ring 585 and a threaded orifice 586. FIG. 6 shows a side and perspective view of alignment pin 475 and O'ring 481. In FIG. 4 fluid control valve 457 has a valve body 459 which has a valve bore 483 and a threaded top end 468. Fluid control valve 457 is machined from aircraft grade aluminum alloy stock although many other materials could be used such as acrylic and other types of plastic, brass, steel and other metal alloys. Valve bore 483 contains a valve slide 461 and has a female thread 482 on it lower end which is countersunk at its outer edge to sealingly receive a hex plug 460 which is constructed of steel, is threaded to fit, and has an integral O'ring (not shown). Valve body 459 has a used fluid inlet port 479 on its right side which receives hose barb 458. Valve body 459 has a fresh fluid delivery port 480 on its left side which receives 90 degree hose barb 463 (hose barbs 458 and 463 are first shown in FIG. 3). Both hose barb 458 and 90 degree hose barb 463 are provided with O'rings (not shown) for sealing against valve body 459. All ports which receive hose barbs are suitably prepared with female threads which matingly receive corresponding male threads of those hose barbs. This is well understood by those with average skill in the art. Both used fluid inlet port 479 and fresh fluid delivery port 480 are suitably countersunk at their outside edge to suitably accept and retain O'rings which are supplied with hose barb 458 and 90 degree hose barb 463 and which provide effective fluid sealing at threaded, countersunk ports. Not shown in FIGS. 4 & 5, the threaded orifice 586 (see FIG. 6) is provided to valve body 459 which extends from the outside of valve body 459 through its side wall into valve bore 483, and which receives an alignment pin 475 that is threaded in its middle section and provided with a smooth ground end which extends into valve bore 483. The smooth ground end of alignment pin 475 is positioned to protrude into an alignment groove 474 which is machined into the right front side of valve slide 461. Alignment groove 474 of valve slide 461 is arranged to slide up and down vertically on middle threaded alignment pin 475, thereby allowing vertical up and down movement of valve slide 461 but no rotation within valve bore 483. The use of alignment pin 475 and alignment groove 474 keeps valve slide 461 in proper alignment with the ports of valve body 459 which is required for correct operation, and also keeps valve slide 461 from leaving valve bore 483 if the fluid exchanger 325 is ever inadvertently turned upside down. Valve body 459 has a O'ring gland 477 provided at its top edge which receives an O'ring 481 and which provides a suitable seal between valve body 459 and the bottom common wall 349 as shown in FIG. 3. Valve slide 461 has a common inlet port/fresh fluid channel 464 which is machined to originate at the top left side of valve slide 461 and to extend downward to the bottom of valve slide 461, thereby providing a fresh fluid delivery channel for fresh fluid 329 of FIG. 3 to be delivered into, through, and out of valve slide 461 to enter hose barb 480. Common inlet port/fresh fluid channel 464 has a second important function also which is providing a vent between the top to the bottom of valve bore 483, thereby allowing valve slide 461 to move freely and responsively to the vertical movement upward or downward of float 472 without becoming hydro-locked in valve bore 483. Valve slide 461 has a side port 499 which extends from inlet port/fresh fluid channel 464 through the right outside of valve slide 461. Valve slide 461, has a collar 476 and a float shaft 470 which has a threaded end 471 which receives a retainer nut 473 after float 472 which has a vertical valve bore is inserted on top of float shaft 470. Float 472 is constructed of an air tight, air containing thin walled brass formed container which is brazed at its bottom seam (not shown) and has an air tight open center which is suitably formed to mate with the top portion of valve slide 461 above collar 476 and the top shaft of valve slide 471. Float 472 is sealed in such a fashion that fluid cannot leak into its air cavity held inside, which provides the buoyancy for flotation in power steering fluid 329 of FIG. 3. Float 472 is large enough to contain an adequate volume of air to provide enough buoyancy to be able to overcome the total weight of valve slide 461, its retainer nut 473 and float 472 to reliably raise and hold valve slide 461 in its upper position when fresh fluid reservoir 328 of FIG. 3 contains even a minimum volume of fresh fluid 329 of at least ½ quart. In this case the float dimensions are approximately 6 inches in diameter by 1⅞ inches thick. Additionally, the total weight of valve slide 461 with its retainer nut 473 and float 472 must be heavy enough to cause the movement valve slide 461 downward when the supply level of fresh fluid 329 drops, given that the total sidewall clearance between valve slide 461 and valve bore 483 being approximately 0.010 inch. There are other materials and methods which can be used to construct float 472 which provide suitable buoyancy, which are structurally strong enough, and which are adequately resistant to power steering fluid to permit a long and reliable service life. Various types of plastics such as acrylic and nylon can be molded and filled with air or light weight foam to comprise a suitable float with an adequate service life, and there are other metal alloys which can be constructed to be thin walled and sealed together by an appropriate type of welding, soldering or brazing depending on the alloy used. Valve slide 461 has a seal 465 which is tight fitting on valve slide 461 and in this embodiment is constructed of a Viton® type rubber O'ring which is installed underneath collar 476. When slide 461 reaches the end of its downward motion seal 465 is pinched between collar 476 and threaded top end 468 of valve body 459 to provide an essentially air tight seal between fresh fluid reservoir 328 of FIG. 3 and valve bore 483. Valve slide 461 has an orifice 484 provided to its lower end which receives a magnet 469 which is secured with a suitable epoxy glue which is resistant to power steering fluid. Valve body 459 has a threaded orifice 478 which extends to a depth no closer to valve bore 483 than 0.050 inch. Threaded orifice 478 receives a magnetically operated micro-switch 462 which is threaded to be matingly screwed into threaded orifice 478. FIG. 4 shows valve slide 461 in its upper position which results from fresh fluid reservoir 328 having an adequate supply of fresh fluid 329 in at least a minimum quantity of ½ quart which causes float 472 to rise under the power of its buoyancy in fresh fluid 329. When valve slide 361 is in its upper position used fluid inlet port 479 is blocked by the right side of valve slide 361 and fresh fluid delivery port 480 is open and able to pass fresh fluid 329 from the fresh fluid reservoir 328 through inlet port/fresh fluid channel 464. FIG. 5 shows valve slide 461 in lower position which results from the depletion of the supply of fresh fluid 329 in fresh fluid reservoir 328 which causes float 472 to lose its buoyancy and drop. When valve slide 361 is in its lower position used fluid inlet port 479 is open to pass used fluid 327 through side port 499 at the right side of valve slide 361 and fresh fluid delivery port 480 is open and able to pass fresh fluid 329 from the fresh fluid reservoir 328 through inlet port/fresh fluid channel 464. Even when valve slide 461 is in its lower position and seal 465 is pinched between collar 476 and threaded top end 468, fresh fluid delivery port 480 is open to inlet port/fresh fluid channel 464. When slide 461 is in its lower position inlet port/fresh fluid channel 464 is blocked only at its top end and is positioned to allow used fluid 327 to pass through from used fluid inlet port 479 to fresh fluid delivery port 480. When slide 461 is in its lower position magnet 469 lines up with magnetically operated micro-switch 462 and activates it. FIG. 6 shows the threaded orifice 586 of valve body 459 which extends into valve bore 483 and receives alignment pin 475, which is screwed into it and sealed with anaerobic hydraulic sealer or other suitable hydraulic thread sealer. FIG. 6 also shows an O'ring 585 which is fitted to 90 degree hose barb 463 by the hose barb manufacturer for adjustable fluid tight sealing. This method of hydraulically sealing a hose barb in a threaded port which is countersunk on the hose barb side is well known to someone of average skill in the art. FIG. 6 also provides a perspective view of O'ring 481 which is used to seal off valve body 459 from the fresh fluid reservoir 328. FIG. 6 also shows valve body 459 provided with the threaded orifice 478 which does not penetrate toward valve bore 483 any closer than 0.050 inch and which receives a magnetically operated micro-switch 462 which is matingly threaded to be screwed into threaded orifice 478. Micro-switch 462 is connected to complete a series configured electrical circuit (not shown) when activated by magnet 469, and this electrical circuit is comprised of an on-off lighted toggle switch wired to a red LED indicator, a buzzer and a replaceable 9 volt battery of the type used in smoke detectors and many other small devices. This electrical circuit, with its lighted on-off toggle switch, red LED indicator, buzzer, and 9 volt battery are not shown but are known to those of ordinary skill in the art. Alternatively, a fluid operated in-line flow switch at the used fluid receiver end of used fluid exchange hose 354 can be substituted for the toggle switch and this would automatically turn off the red LED and buzzer when fresh fluid supply 329 was depleted and the vehicle's engine is turned off. This type of flow switch is readily available in a number of forms such as a flow switch containing a displaceable piston which contains a magnet which triggers a magnetic sensor or micro-switch. These are known to those of average skill in the art. FIG. 7 depicts the power steering fluid exchanger 325 in proper connective arrangement to the type of power steering system as shown in FIG. 1 which has a combination pump reservoir assembly 192. In FIG. 7 fluid exchanger 325 is shown ready to exchange the power steering fluid of the power steering system shown in FIG. 1. FIG. 7 does not show the parts inside the skirt base 340 of fluid exchanger 325 (which are shown in FIG. 3). Fluid exchanger 325 is positioned somewhat above the level of fluid reservoir 100 of the power steering system being serviced, and is typically placed upon the top of one of the fenders, or on top of the engine to rest upon the set of four footpads 341. In some situations the power steering pump of a vehicle is powerful enough to provide adequate low pressure (suction) at its inlet port to allow fluid exchanger 325 to be position at or even somewhat below the level of fluid reservoir 100 of the power steering system being serviced. However, placing fluid exchanger 325 above or somewhat above the level of the fluid reservoir being serviced assures that the low pressure (suction) provided by the power steering pump to the fresh fluid exchange hose 466 when the vehicle is started will be adequate to easily deliver the fresh fluid to the inlet port of the power steering pump 105. The operator carries and positions fluid exchanger 325 by using handle 339. In some cases the operator will choose to hang the fluid exchanger from a hood lock bracket or other projected or available orifice or extension at the underside of the raised hood of the vehicle using a hanger bracket 1905 of FIG. 26 which has a bracket base 1906 which is wide enough to receive handle 339 of the fluid exchanger of FIG. 3 and a hook 1907 which is inserted into and through an appropriate orifice, projected member, or protuberance under the front side of the hood (not shown). The hanger bracket 1905 can be constructed of bent 8 gauge steel rod which is then chrome plated and which has an appearance similar to a heavy duty double hook used to hang paint cans by their wire handles on ladder rungs. To hang fluid exchanger 325 from the hood it is necessary for the hood to be supported. This support can be provided by a vehicle's hood support rod (not shown) which has been placed into proper holding position if the vehicle is so equipped, or by using an adjustable hood support rod 1909 of FIG. 26 which can be suitably positioned and adjusted to proper length to keep the hood propped open while the fluid exchanger is hung from a hood lock bracket or other orifice, projection member or protuberance under the front side of the hood until the fluid exchange service is completed. The adjustable hood support rod 1909 of FIG. 26 has a base rod section 1910 which has a bottom rod pad 1914 attached at its bottom end. Bottom rod pad 1914 is comprised of a mineral oil resistant rubber type material such as nitrile or Viton®. The adjustable hood support rod 1909 has a top rod section 1913 to which the base rod to the base rod section 1909 slides freely into in varying penetrations. Top rod section 1913 has a top rod pad 1915 attached at its top end. Top rod pad 1915 is comprised of a mineral oil resistant rubber type material such as nitrile or Viton®. The adjustable hood support rod 1909 has a spring loaded releasable latch 1911 which secures the top rod section 1913 to the bottom rod section 1914 at the adjusted length necessary to prop open the vehicle's hood securely. The top rod pad 1915 and the bottom rod pad 1914 are somewhat pliable to conform to the surface pressed against providing a relatively slip resistant mating but yet firm enough to return to shape. The top rod pad 1915 has a nipple 1916 which extends upward to mate with a chosen hole of the inside sheet metal of the underside of the front hood. Before fluid exchanger 325 was connected to the power steering system of FIG. 1 as shown in FIG. 7, the used fluid receiver 326 was emptied of used fluid 327 from a prior fluid exchange by moving valve operating lever 343 to open valve 342 and allowing used fluid 327 to be discharged into a suitable waste container or floor drain. Cap 323 was then removed to fill the fresh fluid reservoir 328 with approximately 3 quarts of fresh fluid 329 which is the type of power steering fluid required by the manufacturer of the vehicle being serviced. Fresh fluid 329 was poured through strainer 334 to prevent any debris smaller than approximately 50 microns from entering and contaminating fluid 329 inside fresh fluid reservoir 328. The filling of the fresh fluid reservoir 328 with fresh fluid 329 was then followed by the replacement of cap 333. The Filling of fresh fluid reservoir 328 results in the rising of float 472 to its upper position has moved valve slide 461 as shown in FIG. 4. The special adapter kit parts shown separately in FIG. 8 have been suitably connected to the power steering system as shown in FIG. 7. Cap 103 of FIG. 1 was removed from filler neck 102 of reservoir 100 of the power steering system to be set aside until the completion of the fluid exchange service. Hose clamp 117 was loosened on hose end 115 which was then pulled off of reservoir return port 116. A ⅜ male tube adapter 787 of FIG. 8 has a ⅜ inch outside diameter male tube and was inserted into hose end 115 and sealably secured with hose clamp 117. The ⅜ male tube adapter 787 of FIG. 8 is provided with a small male quick connect 788. A port plug 786 of FIG. 8 is constructed of Viton® type rubber and is suitably sized to be securely and sealingly placed over reservoir return port 116. Port plug 786 was pressed into place on port 116 to seal it from leakage of used fluid 327 or fresh fluid 329, or some combination thereof from reservoir 100 outward and from any leakage of air inward to reservoir 100 when low pressure is applied to reservoir 100. Power steering reservoir 100 was then topped off with fresh power steering fluid of the proper type all the up to the top of filler neck 102. A cap adapter 789 of FIG. 8 has a large male quick connect 790. Cap adapter 789 provides a fluid channel into reservoir 100 of FIG. 7 when installed on reservoir 100. Cap adapter 100 has been manufactured to be non-vented. Cap adapter 789 was placed on filler neck 102 and turned clockwise to sealingly secure it. Cap adapter 789 is air and fluid tight when properly placed and secured on filler neck 102. Power steering reservoir caps typically have vent passages at their inside center which are vented to the sides of the cap and are hidden from view, located under a gasket, but cap adapter 789 has no such vent. Cap adapter 789 of FIG. 8 is installable on many GM, Chrysler and Ford traditional types of power steering systems that have a reservoir-pump combination configuration. Large male quick connect 790 of cap adapter 789 is connected to the large female quick connect 367 of fresh fluid exchange hose 366. The small male quick connect 788 of ⅜ male tube adapter 787 is then connected to the small female quick connect 355 of used fluid exchange hose 354. The power steering system shown in FIG. 7 is now ready for the fluid exchange to be instituted which automatically begins when the engine of the vehicle is started. The exchanging of the fresh fluid 329 of the fluid exchanger 325 for the power steering system's used fluid 327 will be automatically stopped when the supply of fresh fluid 329 becomes depleted. FIG. 9 depicts the power steering fluid exchanger 325 in proper connective arrangement to a remote reservoir type power steering system as shown in FIG. 2. The used fluid receiver 327 has been emptied and the fresh fluid reservoir 328 has been filled with approximately three quarts of the type of power steering fluid required by the vehicle's manufacturer and this has caused float 472 to rise to its upper position. The ⅜ male tube adapter 787 has been inserted into hose end 215 and sealingly secured with hose clamp 117. The ⅝ male tube adapter 991 has been inserted into pump supply hose 208 and sealingly secured with hose clamp 117. The fresh fluid exchange hose 366 and the used fluid exchange hose 354 of fluid exchanger 325 have been suitably connected to the power steering system by connecting large female quick connect 367 of fresh fluid exchange hose 366 to the large male quick connect 790 of ⅝ male tube adapter 991, and by connecting the small female quick connect 355 of used fluid exchange hose 354 to the small male quick connect 788 of ⅜ male tube adapter 787. The power steering system shown in FIG. 9 is now ready for the fluid exchange to be instituted which automatically begins when the engine of the vehicle is started. FIG. 10 depicts the special adapter kit which is used to provide proper connection of fluid exchanger 325 to the power steering system of FIG. 2 as shown in FIG. 9. The kit consists of ⅝ male tube adapter 991 which is ⅝ inches outside diameter, ⅜ male tube adapter 787 which is ⅜ inch outside diameter, and a set of two hose clamp 117. The ⅝ male tube adapter 991 is provided with the large male quick connect 790. The ⅜ male tube adapter 787 is provided with the small male quick connect 788. The large male quick connect 790 is connectable to the large female quick connect 367 of used fluid exchange hose 366 as shown in FIG. 9. The small male quick connect 788 is connectable to the small male quick connect 355 of used fluid exchange hose 354 as shown in FIG. 9. FIG. 11 depicts a specific style of a remote reservoir system seen in certain late model Ford manufactured vehicles that has a remotely arranged reservoir. A reservoir 1000 is comprised of translucent plastic and has a fill spout 1002 which extends out of reservoir 1000 in angular fashion. Fill spout 1002 has a cap 1003 which is somewhat snug fitting. Reservoir 1000 has a reservoir outlet port 1006 to which pump supply conduit 1008 is sealably secured with hose clamp 117. Reservoir 1000 has a reservoir return port 1016 to which the hose end 1015 is sealably secured with a hose clamp 117. FIG. 12 depicts the connection of the invention's special adapters to the power steering system shown in FIG. 13 which allows a quick connection of the fluid exchanger 325 to that power steering system. FIGS. 14 & 15 depict the connection of the inventions special adapters to the power steering system shown in FIG. 13 which allow a quick connection of the fluid exchanger 325 to that power steering system. FIG. 12 depicts the adapters used to establish proper connective arrangement between the remote reservoir system of FIG. 11 and the power steering fluid exchanger 325 of FIG. 3. A cap adapter 1185 is specially manufactured to fit snugly into filler neck 1002 to provide an air and fluid tight seal when inserted into filler neck 1002. Cap adapter 1185 is provided with an O'ring 1187 and an O'ring 1188 and is also provided with the large quick connect 790. The original equipment cap 1003 of FIG. 11 is removed and set aside until the completion of the fluid exchange procedure. Cap adapter 1185 is installed in filler neck 1002. Hose clamp 117 is loosened and hose end 1015 is pulled away from reservoir return port 1016. The ⅜ male tube adapter 787 of FIG. 8 is inserted into hose end 1015 and sealingly secured with hose clamp 117 and has small quick connect 788. Port plug 786 of FIG. 8 is installed on reservoir return port 1016 to provide an air and fluid tight seal to reservoir return port 1016. Pump supply conduit 1008 is left attached to reservoir 1000. Reservoir 1000 is topped off about halfway up filler neck 1002, and cap adapter 1185 is pushed down and into filler neck 1002, where is provides an air tight seal with almost no air left in filler neck 1002. Connection of the adapters to the power steering fluid exchanger 325 is quickly instituted by connecting the large female quick connect 367 of fresh fluid exchange hose 366 of FIG. 3 to the large male quick connect 790 of cap adapter 1185, and by connecting the small female quick connect 355 of used fluid exchange hose 354 to the small male quick connect 788 of the ⅜ male tube adapter 787. Any air left in filler neck 1002 quickly rises upward to vent into the fresh fluid reservoir 328 and is replaced by fresh fluid 329 draining down into filler neck 1002 through cap adapter 1185 as soon as the large female quick connect 367 of fresh fluid exchange hose 366 is connected to the large male quick connect 790 of cap adapter 1185. FIG. 13 depicts the specific style of reservoir-pump combination system seen in certain late model Diamler-Chrysler manufactured vehicles. A reservoir-pump combination 1292 has a reservoir 1200 which is comprised of translucent plastic with a fill spout 1202 and a cap retainer ring 1294 which has locking tab grooves (not shown). Fill spout 1202 has a cap 1203 which is fitted with an O'ring 1293. Cap 1203 also has locking tabs (not shown) which matingly and securely engage the locking tab grooves of cap retainer ring 1294. Reservoir 1200 has a reservoir return port 1216 to which hose end 1215 is sealably secured with a hose clamp 117. A pressure conduit 1210 is connected to a pump outlet port 1209 of a power steering pump 1205. FIG. 14 depicts the adapters used to establish proper connective arrangement between the reservoir-pump combination system of FIG. 13 and the power steering fluid exchanger 325 of FIG. 3. A cap adapter 1395 is specially manufactured to fit snugly into filler neck 1202 to provide an air and fluid tight seal when inserted into filler neck 1202. Cap adapter 1395 is provided with an O'ring 1396 and an O'ring 1397 and is also provided with the large quick connect 790. The original equipment cap 1203 of FIG. 13 is removed and set aside until the completion of the fluid exchange procedure. Hose clamp 117 is loosened and hose end 1215 is pulled away from reservoir return port 1216. Port plug 786 of FIG. 8 is installed on reservoir return port 1216 to provide an air and fluid tight seal to reservoir return port 1216. The ⅜ male tube adapter 787 of FIG. 8 is inserted into hose end 1215 and sealingly secured with hose clamp 117. The ⅜ male tube adapter 787 has small quick connect 788. Cap adapter 1395 is then installed into filler neck 1202. Reservoir 1200 is topped off about halfway up filler neck 1202, and cap adapter 1395 is pushed down and into filler neck 1202, where it provides an air and fluid tight seal with almost no air left in filler neck 1202. Any air left in filler neck 1202 quickly rises upward to vent into the fresh fluid reservoir 328 and is replaced by fresh fluid 329 draining down into filler neck 1202 through cap adapter 1385 as soon as the large female quick connect 367 of fresh fluid exchange hose 366 is connected to the large male quick connect 790 of cap adapter 1185. Connection of the adapters to the power steering fluid exchanger 325 is instituted by connecting the large female quick connect 367 of fresh fluid exchange hose 466 of FIG. 3 to the large male quick connect 790 of cap adapter 1395, and by connecting the small female quick connect 355 of used fluid exchange hose 354 to the small male quick connect 788 of the ⅜ male tube adapter 787. Pressure conduit 1210 is left connected to pump outlet port 1209. FIG. 15 depicts the adapters used to establish an alternative type of connective arrangement between the remote reservoir system of FIG. 13 and the power steering fluid exchanger 325 of FIG. 3. A special sealed cap 1495 is non-vented and is constructed to provide an air and fluid tight seal to filler neck 1202 during the fluid exchange. Cap 1495 has locking tabs (not shown) which matingly engage locking tab grooves of cap retainer ring 1294 (not shown). Cap 1495 is provided with an O'ring 1496 and an O'ring 1497. The original equipment cap 1203 of FIG. 13 is removed and set aside until the completion of the fluid exchange procedure. Cap 1495 is installed in filler neck 1202. Hose clamp 117 is loosened and hose end 1215 is pulled away from reservoir return port 1216. The ⅜ male tube adapter 787 is inserted into hose end 1215 and sealingly secured with hose clamp 117. The ⅜ male tube adapter 787 of FIG. 8 has small quick connect 788. A ⅜ female hose adapter 1498 is pushed on over reservoir return port 1216 and sealingly secured with hose clamp 117. The ⅜ female hose adapter 1498 is provided with large male quick connect 790. Reservoir 1200 is topped off about halfway up filler neck 1202, and cap adapter 1495 is slowly pushed down to displace almost all of any air remaining in filler neck 1202, where it provides an air and fluid tight seal. Connection of the adapters to the power steering fluid exchanger 325 is instituted by connecting the large female quick connect 367 of fresh fluid exchange hose 366 of FIG. 3 to the large male quick connect 790 of ⅜ female adapter 1498, and by connecting the small female quick connect 355 of used fluid exchange hose 354 to the small male quick connect 788 of the ⅜ male tube adapter 787. FIGS. 16-17 depict another embodiment of the invention, fluid exchanger 1525 which features a fluid control valve 1557 which is operated by a float 1572, the operation of which is assisted by positive pressure provided by the power steering pump through its outlet port. FIGS. 16 & 17 depict the detailed construction of fluid control valve 1557 and its parts arrangement, as does FIG. 18, which shows an exploded perspective view of fluid control valve 1557 with float 1572. FIGS. 16 & 17 show only the approximate lower half of a fluid exchanger 1525 without the skirt base 340 of FIG. 3. Fresh fluid reservoir 328, used reservoir 326, bottom common wall 349, fresh fluid exchange hose 366, used fluid exchange hose 354, and check valve 350 are the same as depicted in FIG. 3. The parts of fluid exchanger 1525 which are not shown in FIGS. 16 & 17 are the same as those shown in FIGS. 7 & 9, with the exception of fluid control valve 1557, a used fluid conduit assembly 1554, a fresh fluid supply conduit 1524, and a fresh fluid conduit 1566, and minor differences to float 1572, and to a float shaft 1570. FIGS. 16 & 17 show a side view and with FIG. 18 showing an exploded perspective view. All the parts of FIG. 18 are visible in FIGS. 16 & 17 with the exception of a threaded orifice 1586. FIG. 18 shows alignment pin 475 and O'ring 481 from a side and perspective view which is more revealing than FIGS. 16-17. Fluid control valve 1557 has a valve body 1559 which has a valve bore 1583, a threaded top end 1568 and a female thread 1582 which receives a threaded hex plug 460 which has an O'ring installed. Fluid control valve 1557 as shown in FIG. 16 has a valve slide 1561 that is shown in its upper position, which places valve 1557 in operative condition to exchange the fluid of the power steering system being serviced (not shown) when properly connected and the engine is operated. Fresh fluid reservoir 328, used reservoir 326, bottom common wall 349, fresh fluid exchange hose 366, used fluid exchange hose 354, and check valve 350 are the same as depicted in FIG. 3. In FIGS. 16-17, the power steering fluid exchanger 1525 has a float operated automatic fluid control valve 1559 which uses positive fluid pressure to assist the movement of a valve slide 1561 downward and the sealing off from fresh fluid reservoir 328 by positive pressure provided to used fluid 327 by the power steering pump as it is discharged through its outlet port and delivered through the steering mechanism and the used fluid exchange hose 354 to communicate with the top side of valve slide 1561 of control valve 1557 through fluid power port 1502 as valve slide 1561 first drops a short distance to partially open fluid power port 1502. Float 1572 is constructed of an air tight, air containing thin walled brass formed container which is brazed at its bottom seam (not shown) and has an open center which is suitably formed to mate with the top portion of float shaft 1570, which has a upper threaded end 1571 and a lower threaded end 1504 with lower threaded end 1504 matingly screwed into a threaded orifice 1501 at the top side of valve slide 1561. Flat shaft 1571 has a collar 1576 integral to it which supports float 1572 and which has a seal 1565 placed underneath it. Seal 1562 in this instance is an O'ring of the approximate diameter of float shaft 1570 and installed snugly on it under collar 1576. Seal 1562 is constructed of Viton® and is pinched between collar 1576 and threaded top end 1658 of valve body 1559 when valve slide 1561 is forced downward under the positive pressure provided to the top side of slide 1561 through fluid power port 1502. Upper threaded end 1571 of float shaft 1570 has retainer nut 453 matingly screwed onto it after float 1572 is placed onto float shaft 1570 to rest tight against the top side of the collar 1576 of float shaft 1570. Valve slide 1561 is slidingly received in a valve bore 1583 of a valve body 1559 of control valve 1557. Valve bore 1583 is segmented with the very top portion short in length having a narrow diameter suitable to slidingly receive float shaft 1570 with approximately 0.010 inch sidewall clearance, and with the longer bottom portion much longer in length and having a much larger diameter which is suitable to receive valve slide 1561 with approximately 0.010 inch sidewall clearance. There are other materials and methods which can be used to construct float 1572 which are suitably buoyant and structurally strong enough and resistant enough to power steering fluid for a long and reliable service life. Some suitable alternate materials are various types of plastics which can be molded and filled with air or light weight foam plastic. Float 1572 is large enough to contain an adequate volume of air to provide enough buoyancy in power steering fluid 329 to be able to overcome the total weight of valve slide 1561 with its float shaft 1570, retainer nut 473, and float 1572 to reliably raise and hold valve slide 1561 in its upper position when fresh fluid reservoir 328 contains even a minimum volume of fresh fluid 329 of at least ½ quart. Additionally, the total weight of valve slide 1561, float 1572, and float shaft 1570 with its retainer nut 473 must be heavy enough to move valve slide 1561 downward at or close to its lowest position when the supply of fresh fluid 329 is depleted and the buoyancy of float 1772 is thereby removed. In this embodiment the float dimensions are approximately 6 inches in diameter by 2 inches thick. Float shaft 1570 is comprised of cold rolled steel for weigh, strength and resistance to bending, but a number of other materials can be suitably selected such as brass, aluminum alloy, magnesium alloy, and various other types of steel, refined metals and formed plastics. Valve body 1559 and valve slide 1561 are machined from aircraft grade aluminum alloy stock for lightness, strength, durability, and ease of machining, however a number of other materials including cold rolled steel, brass, acrylic plastics and other plastic compounds can be suitably selected as alternatives for constructing valve body 1559, valve slide 1561 and float shaft 1570. Valve slide 1561 is provided with an orifice 1584 which receives a magnet 469 which is securely glued in place with an epoxy glue that is suitably resistant to power steering fluid. Valve slide 1561 is also provided with an alignment groove 1574 which sliding receive the smooth ground end of a middle threaded alignment pin 475 which is screwed into a threaded orifice 1586 (shown in FIG. 18) which penetrates from the outside of valve body 1559 inward toward valve bore 1583 no closer than 0.050 inch. Threaded orifice 1586 is provided with middle threaded alignment pin 475 which is screwed into it with its smooth ground smaller diameter end penetrating into valve bore 1583 the proper distance to slidingly engage alignment groove 1574 of valve slide 1561. Middle threaded alignment pin 475 is sealed to be fluid tight by using a suitable anaerobic hydraulic sealer or other hydraulic sealer which is suitably resistant to power steering fluid. Valve slide 1561 cannot rotate in valve bore 1583 because the alignment groove 1574 can only slide vertically around the smooth end of middle threaded alignment pin 475. Valve body 1559 is provided with a threaded orifice 1578 from its outside which extends to about 0.050 inch less than valve bore 1583. Threaded orifice 1578 matingly receives a magnetically operated micro-switch 462 which is matingly threaded. Valve body 1559 is provided with a vertically running fluid vent channel 1503 which runs from the center of the bottom side of valve slide 1561 upward into a fluid channel 1599. The fluid vent channel 1503 prevents valve slide 1561 from become hydro-locked in valve bore 1583 and allows it to travel up and down without undue restriction. Valve body 1559 is fitted with four fluid ports, a fresh fluid delivery port 1500, a used fluid inlet port 1548, a fluid power port 1502, and a fresh fluid inlet port 1580. The top large edge of valve body 1559 which is located just under threaded top end 1568 is provided with an O'ring gland 1577 which receives O'ring 481 to provide adequate sealing of valve body 1559 to the fresh fluid reservoir 328. Valve slide 1561 is fitted with fluid channel 1599 extending from fresh fluid inlet port 1580 to fresh fluid delivery port 1500 which establishes fluid communication between these two ports when suitably positioned. A used fluid conduit assembly 1554 establishes communication between used fluid exchange hose 354, check valve 350, used fluid inlet port 1548, and fluid power inlet port 1502. A fresh fluid conduit assembly 1566 establishes communication between fresh fluid exchange hose 366 and fresh fluid delivery port 1500. Fresh fluid exchange hose 366 is inserted over the non-port end of fresh fluid conduit assembly 1566 and sealingly secured with hose clamp 117. Used fluid exchange hose 354 is inserted over the non-port end of used fluid conduit assembly 1554 and sealingly secured with hose clamp 117. Bottom common wall 349 of fluid exchanger 1525 is provided with a fresh fluid supply port 1523 at the bottom right of fresh fluid reservoir 328. Fresh fluid supply port 1523 is provided with a welded wire float cage 1522 which contains a float ball 1521 of approximately 1¼ inch diameter. Float ball 1521 sealingly closes off fresh fluid supply port 1523 when in reaches its lower position when the supply of fresh fluid 329 becomes depleted. In this instance float ball 1521 is a hollow sphere comprised of acrylic plastic with a wall thickness of approximately 0.050. Float ball 1521 as constructed to hold air inside is lighter than power steering fluid. Float ball 1521 can alternatively be comprised of a number of other suitable materials which are lighter than power steering fluid when filled with air such as various types of plastic and metals including nylon, aluminum alloy, thin walled steel or other alloys as long as its outside surface it substantially spherical with a smooth surface. Float ball 1521 must be strong enough not to collapse when the low pressure of the power steering pump is applied to its lower side upon depletion of the supply of fresh fluid 329. The top side of fresh fluid supply port 1523 is concave to sealingly receive float ball 1521 and has a rubber like surface vulcanized to its sealing surface for float ball 1521 which in this embodiment is comprised of viton® or nitrile material. A fresh fluid supply conduit 1524 connects fresh fluid supply port 1523 and fresh fluid inlet port 1580. Each of the ports of valve body 1559 as well as the outlet port of check valve 350 is fitted with SAE type male fittings to which each has a female tube nut holding a flared end of a conduit to be sealingly secure. These SAE type fittings, tube nuts and flared conduit ends are not shown but understood by those of average skill in the art. Used fluid conduit assembly 1554, fresh fluid conduit assembly 1566, and fresh fluid supply conduit 1524 are in this instance comprised of extruded hydraulic steel tubing. There are however a number of other alternative materials which can be used to construct used fluid conduit assembly 1554, fresh fluid conduit 1566, and fresh fluid supply conduit 1524 such as polyethylene plastic and other types of suitable plastic tubing, nylabraid® type hose, copper tubing, aluminum tubing, and various types of rubber hose which are resistant to power steering fluid if suitably compatible fittings are provided with such alternate materials. In FIG. 16 valve slide 1561 is shown in its upper position. When valve slide 1561 is in its upper position, it blocks used fluid inlet port 1548 and fluid power port 1502. This upper position establishes a connection between the fresh fluid supply port 1523 and fresh fluid delivery port 1500 through fresh fluid supply conduit 1524 and fluid channel 1599 of valve slide 1561 and this connects fresh fluid supply conduit 1524 and fresh fluid exchange hose 361 through fresh fluid conduit 1566 which establishes communication between the fresh fluid reservoir 328 and the inlet port of the power steering pump (not shown). In FIG. 17 valve slide 1561 is shown in its lower position. When valve slide 1561 is shown in its lower position, it blocks used fluid inlet port 1548, opens fluid power port 1502, and keeps fresh fluid inlet port 1580 and fresh fluid delivery port 1500 open. This lower position establishes a connection between the used fluid inlet port 1548 and fresh fluid delivery port 1500 through fluid channel 1599 of valve slide 1561, while maintaining fluid communication between fluid fresh fluid delivery port 1500, channel 1599 and fresh fluid supply port 1523. As soon as float ball 1521 drops as the supply of fresh fluid 329 becomes depleted to become sealingly positioned onto the top side of fresh fluid supply port 1523, fluid communication between fresh fluid inlet port 1580 and the fresh fluid reservoir 328 through fresh fluid supply port 1523 is blocked. The connection between the used fluid inlet port 1548 and fresh fluid delivery port 1500 through fluid channel 1599 of valve slide 1561 connects used fluid conduit assembly 1554 to fresh fluid conduit 1566 which establishes fluid communication between used fluid exchange hose 354 and fresh fluid exchange hose 361 which established a closed fluid circulation circuit between the used fluid outlet of the power steering pump and its inlet port. This closed fluid circulation circuit does not have a functional reservoir, is not connected to either the fresh fluid reservoir or the used fluid receiver, and is not vented. FIG. 18 shows fluid control valve 1557, its float 1572, and float rod 1570 from an exploded perspective view which is more revealing. In FIGS. 19 & 20 depict the detailed construction of a fluid control valve 1957 and its parts arrangement which is another alternate embodiment of the invention, fluid exchanger 1925. Fluid control valve 1957 is operated by float 1572, the operation of which is assisted by both negative and positive pressure provided by the power steering pump. FIGS. 19 & 20 show only the approximate lower half of a fluid exchanger 1525 without the skirt base 340 of FIG. 3. Fresh fluid reservoir 328, used reservoir 326, bottom common wall 349, fresh fluid exchange hose 366, and used fluid exchange hose 354 are the same as depicted in FIG. 3. The used fluid receiver 326 is fitted with a check valve 350 at bottom common wall 349 through which used fluid 327 is delivered through. The fresh fluid reservoir 328 is fitted with a fresh fluid supply port 1923 at bottom common wall 349 which has a float ball 1521 contained in a wire cage 1522. Fresh fluid supply port 1923 is suitably countersunk on its top side and coated with a Viton® coating of approximately 0.025 inch which is vulcanized to the top side of fresh fluid supply port 1923 adhere. This allows float ball 1521 to seal nicely against fresh fluid supply port 1923 when the fresh fluid supply 329 is depleted. Fluid control valve 1957 has a used fluid conduit assembly 1955, a used fluid conduit 1954, a fresh fluid supply conduit 1924, a fresh fluid conduit assembly 1956, and a valve body 1959 which has a used fluid outlet port 1950, a used fluid inlet port 1948, a fresh fluid outlet port 1900, a fresh fluid inlet port 1980, a power port 1906, and a fluid power port 1902. Used fluid conduit 1954 connects check valve 350 to used fluid outlet port 1950. Used fluid exchange hose 354 is sealingly secured to used fluid conduit assembly 1955 by hose clamp 117 which connects the used fluid exchange hose 354 to fluid power port 1902 and to used fluid inlet port 1948. Fresh fluid exchange hose 361 is sealingly secured to fresh fluid conduit assembly 1956 by hose clamp 117 which connects fresh fluid outlet port 1900 and power port 1906 to fresh fluid exchange hose 366. Valve body 1959 has a valve bore 1983 which is fitted with a valve slide 1961 with a total clearance of 0.010 inch. Valve body 1959 has an O'ring gland 1977 which receives an O'ring 481 which is comprised of either nitrile or Viton®. Valve body 1959 a threaded top end 1968 which is installed into a threaded female port of bottom common wall 349 at the fresh fluid reservoir 328. Valve body 1959 has a top small bore 1969 which slidingly receives float shaft 1570. Float shaft 1570 has an integral collar 1576 and is fitted with seal 1565 underneath it which is an O'ring comprised of either nitrile or Viton®. Float shaft 1570 has float 1572 inserted on top of rim 1576 and secured with retainer nut 473 which is screwed on at the upper threaded end 1571 of float shaft 1570. Valve body 1959 is provided with threaded orifice 1986 which threadingly receives middle threaded alignment pin 475. Valve body 1959 is provided with a female thread 1982 which receives threaded hex plug 460. Valve body 1959 is provided with a threaded orifice 1978 which penetrates the valve body from the outside no closer than 0.050 inch to the valve bore 1983. Threaded orifice 1978 receives magnetically operated micro-switch 462. Valve slide 1961 is provided with an alignment groove 1974 which slidingly receives the smooth ground narrowed end of alignment pin 475. Valve slide 1961 is provided with a threaded orifice 1901 which receives lower threaded end 1504 of float shaft 1570. Valve slide 1961 is provided with a cross fluid channel 1999, a side fluid channel 1998, a fluid vent 1903 at its lower end, and an orifice 1984 which receives a magnet 469. In FIG. 19 valve slide 1961 is shown in its upper position. When valve slide 1961 is in its upper position it establishes a connection between the fresh fluid supply port 1923 and fresh fluid outlet port 1900 through fresh fluid inlet port 1980 and fluid channel 1999 of valve slide 1961. This connects fresh fluid supply conduit 1924 and fresh fluid exchange hose 361 through fresh fluid conduit 1956 which establishes communication between the fresh fluid reservoir 328 and the inlet port of the power steering pump (not shown). Fluid power port 1902 is blocked by valve slide 1961. Power port 1906 is open to valve bore 1983, but is neutralized by fluid vent 1903 when slide 1961 is in its upper position. In FIG. 20 valve slide 1961 is shown in its lower position. When valve slide 1961 is shown in its lower position, it blocks fresh fluid inlet port 1980 and used fluid outlet port 1950 and opens fluid power port 1902. This lower position establishes a connection between the used fluid inlet port 1948 and fresh fluid delivery port 1900 through side fluid channel 1998 of valve slide 1961. This connects used fluid conduit assembly 1955 to fresh fluid conduit 1956 which establishes fluid communication between used fluid exchange hose 354 and fresh fluid exchange hose 366 which is a closed fluid circulation circuit between the used fluid outlet of the power steering pump and its fresh fluid inlet. FIG. 21 depicts an alternative embodiment of a mechanical/hydraulic fluid control valve 2157 which is very basic and simple. FIG. 21 shows only the approximate lower half of a fluid exchanger 2125 without the skirt base 340 of FIG. 3. Fresh fluid reservoir 328, used reservoir 326, bottom common wall 349, fresh fluid exchange hose 366, and used fluid exchange hose 354 are the same as depicted in FIG. 3. The used fluid receiver 326 is fitted with a check valve 350 at bottom common wall 349 through which used fluid 327 is delivered. The fresh fluid reservoir 328 is fitted with a fresh fluid supply port 1523 which is constructed of brass and is installed at bottom common wall 349. Fresh fluid supply port 1523 has a wire float cage 1522 which contains a float ball 1521 which can be molded of rigid acrylic plastic or nylon with a hollow core and when sealingly filled with air is buoyant in power steering fluid. Port 1523 is suitably countersunk and coated with a Viton® coating of approximately 0.025 inch which is vulcanized to adhere. This allows float ball 1521 to seal nicely against port 1523 when the fresh fluid supply 329 is depleted. Fluid control valve 2157 has a valve body 2159 with a valve bore 2183, a female thread 2182 at the lower end which is countersunk at its outside edge to receive a threaded hex plug 460 which has an O'ring. Valve body 2159 is provided with a valve slide 2161 which is fitted to valve bore 2183 to have an approximate sidewall clearance of 0.015 inch. Valve slide 2161 is provided with a fluid vent 2103 which runs from its bottom end to its top end where it expands toward the circumference into two vents, allowing the top of slide 2161 to be provided with a threaded orifice 2101. Threaded orifice 2101 receives float shaft 1570 at a lower threaded end 1504. Valve slide 2161 is provided with a fluid channel 2199. Valve body 2159 is provided with a threaded top end 2168 which is installed into a threaded female port of the lower sidewall of fresh fluid reservoir 328. Valve body 2159 is provided with an O'ring gland 2177 which receives O'ring 481 which provides a fluid and air tight seal between valve body 2159 and the fresh fluid reservoir 328 at the bottom common wall 349. Float shaft 1570 is provided an integral collar 1576 and with upper threaded end 1571 which receives retainer nut 473 after float 1572 is inserted on float shaft 1570. Float shaft 1570 has seal 1565 installed snugly underneath rim 1576. Valve body 2159 is provided with a used fluid outlet port 2180, a used fluid inlet port 2148, and a top small bore 2169 which slidingly receives the lower part of float shaft 1570. A fresh fluid supply conduit 2124 is sealingly secured to fresh fluid exchange hose 366 by hose clamp 117 at one end and is connected to used fluid outlet port 2180 and fresh fluid supply port 1523 at its other ends. A used fluid conduit 2154 is sealingly secured to used fluid exchange hose 354 by hose clamp 117 at one end and is connected to used fluid inlet port 2148 and fresh fluid supply port 1523 at its other ends. Valve slide 2161 is shown in its upward position in FIG. 21 which shows it to be blocking communication between used fluid inlet port 2148 and used fluid outlet port 2180. When valve slide 2161 is in its downward position, fluid channel 2199 provides communication between used fluid inlet port 2148 and used fluid outlet port 2180, which establishes a closed fluid circulation circuit between the outlet port of the power steering pump and its inlet port. FIG. 22 depicts an alternative embodiment of an electrical/hydraulic fluid control valve 2257 which is controlled by a float switch assembly 2272. FIG. 22 shows only the approximate lower half of a fluid exchanger 2225 without the skirt base 340 of FIG. 3. Fresh fluid reservoir 328, used reservoir 326, bottom common wall 349, fresh fluid exchange hose 366, and used fluid exchange hose 354 are the same as depicted in FIG. 3. The used fluid receiver 326 is provided with a check valve 350 at bottom common wall 349 through which used fluid 327 is delivered. The fresh fluid receiver 328 is provided with a fresh fluid supply port 1523 at bottom common wall 349 which can sealingly receive a float ball 1521 which is contained inside a wire cage 1522. Float switch assembly 2272 is sealingly secured to the inside of the lower wall of fresh fluid receiver 328 of bottom common wall 349. Float switch assembly 2272 has a float 2271 which is provided with a pair of magnets 2269 and a float shaft 2273 which contains two magnetically operated micro-switches (not shown), an upper micro-switch and a lower micro-switch, each which have contacts which are closed by a pair of magnets 2269 when the float is in an adjacent position. When float 2271 is in its upward position in response to the buoyancy provided by an adequate supply of fresh fluid 329, the pair of magnets 2269 close the upper micro-switch. When fresh fluid supply 329 becomes depleted float 2271 drops to its downward position and this causes the pair of magnets 2269 to leave the proximity of the top micro-switch of float shaft 2273 and then to be adjacent to the lower micro-switch to close its contacts. Each micro-switch has its own set of leads, the upper micro-switch has a pair of upper micro-switch wire leads 2211, and the lower micro-switch has a pair of lower micro-switch wire leads 2212. When fresh fluid supply 329 becomes depleted, float ball 1521 drops into fresh fluid supply port 1523 to seal it air and fluid tight. Fluid control valve 2257 is a two position electric solenoid operated valve with two fluid ports, an inlet port 2261 and an outlet port 2262. The solenoid of fluid control valve 2257 is 12 volt direct current (DC) operated and has a pair of wire leads, one hot and one neutral (some countries other than USA require an additional ground lead) and is spring fed to return to its default mode of operation when electric current is removed from its solenoid, which keeps an outlet port 2262 and an inlet port 2261 connected to establish a closed fluid circulation circuit between the outlet port of the power steering pump and its inlet port. A used fluid conduit assembly 2254 connects check valve 350 with inlet port 2261 of fluid control valve 2257 and with a flow switch 2251 which has internal contacts which are closed only when fluid flows through it at the rate of 0.200 gallons per minute or more. A used fluid conduit 2260 is sealingly secured to used fluid exchange hose 354 by hose clamp 117 at one end and connected to float switch 2251 at it other end. A fresh fluid conduit assembly 2256 is sealingly secured to fresh fluid exchange hose 361 by hose clamp 117 at one end and connected at its other ends to outlet port 2262 of fluid control valve 2257 and to fresh fluid supply port 1523. The two wire leads of fluid control valve 2257 are connected with its neutral connected to the common ground of a battery pack 2258 and with its hot lead to a switched power lead 2210 of a relay assembly 2275 which is a 12 volt DC relay. A battery pack 2258 is provided to fluid exchanger 2225 and is 12 volts DC. Battery pack 2258 snaps into a battery pack socket 2259 which provides current to a relay assembly 2275. Relay assembly 2275 has a magnetic winding which when activated provides current from battery pack 2258 to a switched power lead 2210. Battery packs such as battery pack 2258 and battery pack sockets such as battery pack socket 1529 are used in many manufactured portable and rechargeable power drills and other electrically powered hand tools and are readily available. Battery pack 2258 can be removed from base 2270 for insertion in a suitable battery charger which is connected to a 115 volts alternating current (AC) electrical power source. A buzzer 2255 is powered by 12 volts DC and has two wire leads with one lead connected to a wire lead of an LED 2274 and the other connected to a common ground of battery pack 2258. When activated by electrical current buzzer 2255 emits a 100 decibel pulsing warning tone. LED 2274 is provided with a resistor allowing it to be powered by 12 volts without being burned-out and has two wire leads with one connected a wire lead of buzzer 2255 and the other connected to one of the pair of lower micro-switch wire leads of float switch assembly 2272. When LED 2274 is energized by 12 volt current, it emits a very bright blinking red light which is diffused. Flow switch 2251 has a pair of wire leads with one connected to the magnetic winding 2277 of relay assembly 2275 and with the other one connected to the common ground of battery pack 2258. Magnetic winding 2277 is connected at one end to the hot wire lead of battery pack 2258 and at its other end to flow switch 2251. When used fluid 327 is flowing into and through flow switch 2251, its electrical contacts close and a triggering current is provided to magnetic winding 2277. When magnetic winding 2277 receives this triggering current, current is provided from relay assembly 2275 to switch power lead 2210. The pair of upper micro-switch wire leads are connected, with one lead connected to switched power lead 2210 and the other connected to one wire lead of the solenoid of valve 2257. The other lead of the solenoid of valve 2257 is connected to the common ground of battery pack 2258. In this embodiment float assembly 2272 is provided with heavy duty contacts for the upper and lower micro-switches in float shaft 2273. These contacts are well able to handle the 12 volts direct current needed to power the solenoid of valve 2257 and are wired in series with the solenoid of valve 2257. When the fluid exchanger 2225 is connected to a power steering system after filling its fresh fluid reservoir 328 and emptying its used fluid receiver 326 and the engine is started, used fluid 327 flows through flow switch 2251, the upper micro-switch of float switch assembly 2272 is closed and current is provided to the solenoid of valve 2257. This results in valve 2257 closing and the communication between inlet port 261 and outlet port 262 to be blocked. If one desires to use a less expensive float switch assembly with light duty contacts, an additional relay must be provided so that the full current of battery pack 2258 can be provided to the solenoid of valve 2257 without burning out the contacts of the upper micro-switch which is wired in series with valve 2257. When the level of fresh fluid 329 becomes depleted, float 2271 drops to its lower position which opens the contacts of the upper micro-switch of float switch assembly 2272 and then closes the contacts of the lower micro-switch of float switch assembly 2272. This opening of the contacts of the upper micro-switch of float switch assembly 2272 removes current from the solenoid of valve 2257 and restores fluid communication between inlet port 2261 and outlet port 2262 of valve 2257, establishing a closed fluid circulation circuit between the inlet and outlet ports of the power steering pump and disconnection of that circuit from the fresh fluid reservoir 328 and the used fluid reservoir 326. When float 2271 drops to its lower position the lower micro-switch of float assembly 2272 is closed and current is provided to the LED 2274 and buzzer 2255 until the engine is turned off. When LED 2274 is energized it gives off a bright and diffused blinking red light and when buzzer 2255 is energized it emits a loud 100 decibel pulsing warning tone. When the engine is turned off, used fluid 327 stops flowing through flow switch 2251 and stops it from energizing the magnetic winding 2277 of relay assembly 2275 which disconnect the current of battery pack 2258 from all other electrical components of fluid exchanger 2225. FIG. 23 depicts an alternative embodiment of an electrical/hydraulic fluid control valve 2357 which is operated by a 12 volt direct current (DC) electric solenoid which is controlled by a float switch assembly 2372. FIG. 23 shows only the approximate lower half of a fluid exchanger 2325 without the skirt base 340 of FIG. 3. Fresh fluid reservoir 328, used reservoir 326, bottom common wall 349, fresh fluid exchange hose 366, and used fluid exchange hose 354 are the same as depicted in FIG. 3. The used fluid receiver 326 is fitted with a check valve 350 at bottom common wall 349. The fresh fluid receiver 328 is fitted with a fresh fluid supply port 2353 at bottom common wall 349. Float switch assembly 2372 is sealingly secured to the inside of the lower wall of fresh fluid receiver 328 of bottom common wall 349. Float switch assembly 2372 has a float 2371 which is provided with a pair of magnets 2369 and a float shaft 2373 which contains one light duty magnetically operated micro-switch (not shown) which has a pair of contacts which are closed by a pair of magnets 2369 when the float is in its upward position in response to the buoyancy provided by an adequate supply of fresh fluid 329. When fresh fluid supply 329 becomes depleted float 2371 drops to its downward position and this causes the pair of magnets 2361 to leave the proximity of the magnetically operated micro-switch which opens its electrical contacts. Fluid control valve 2357 is a two position electric solenoid operated valve with three fluid ports, a common outlet port 2362, an activated inlet port 2363, and an inactivated fluid port 2361. Fluid control valve 2357 is spring fed to return to a default mode when electric current is removed from its solenoid, and this default position provides fluid connection between a common outlet port 2362 and inactivated fluid port 2361. A used fluid conduit 2354 is sealingly secured to used fluid exchange hose 354 by hose clamp 117 at one end and connected to check valve 350 and the inlet port 2361 of fluid control valve 2357 at its other ends. A fresh fluid conduit 2356 is sealingly secured to fresh fluid exchange hose 361 by hose clamp 117 at one end and connected at its other end to common outlet port 2362 of fluid control valve 2357. A fresh fluid supply conduit 2324 is connected at one end to activated inlet port of fluid control valve 2357 and to fresh fluid supply port 2353 at its other end. Fluid control valve 2357 contains a 12 volt direct current (DC) electric solenoid (not shown) which is provided with two electrical wire leads, with the hot lead connected to a switched current terminal of a relay (not shown) which is a 12 volt DC and the other lead connected to a common ground. A 12 volt DC onboard rechargeable battery is used as a power supply. Other voltages can be selected for valve 2357 and any electrical components used, and one could use 115 volts alternating current (AC) or 220 volts AC (for countries which use 220 volts AC), but the use of an outside power source requires use of a power cord which must be plugged in to a wall socket and this would detract from the convenience of using the fluid exchanger. The wire leads from float switch assembly 2372 are arranged to connect and energize a magnetic winding (not shown) in the relay (not shown) which provides current to a switched power lead when the toggle switch (not shown) is placed in its on-position which is lighted. This wiring arrangement allows float switch assembly 2372 to function as an electrical trigger when its electrical contacts are closed in response to an adequate level of fresh fluid 329 and the toggle switch is placed in its on-position. When the magnetic winding receives this triggering current, the relay provides switched current to activate the solenoid of fluid control valve 2257 which closes inactivated inlet port 2261 and opens activated inlet port 2263 to establish fluid communication between activated inlet port 2363 and common outlet port 2362. FIG. 24 depicts an alternative embodiment of an electrical/hydraulic fluid control valve 2457 which is operated by an electric solenoid which is controlled by a float switch assembly 2272. FIG. 24 shows only the approximate lower half of a fluid exchanger 2425 without the skirt base 340 of FIG. 3. Fresh fluid reservoir 328, used reservoir 326, bottom common wall 349, fresh fluid exchange hose 366, and used fluid exchange hose 354 are the same as depicted in FIG. 3. The used fluid receiver 326 receives and holds used fluid 327 and is fitted with a used fluid inlet port 2450 at bottom common wall 349. The fresh fluid receiver 328 holds fresh fluid 329 and is fitted with a reservoir outlet port 2453 at bottom common wall 349. Float switch assembly 2272 is sealingly secured to the inside of the lower wall of fresh fluid receiver 328 of bottom common wall 349. Float switch assembly 2272 has a float 2271 which is provided with a pair of magnets 2269 and a float shaft 2273 which contains two heavy duty magnetically operated micro-switches (not shown), an upper micro-switch and a lower micro-switch which each have a pair of contacts which are closed by a pair of magnets 2269 when the float is in an adjacent position. Each micro-switch of float switch assembly 2272 has its own set of wire leads, a pair of upper micro-switch leads 2411 and a pair of lower switch leads 2412, respectively. One lead of the pair of upper micro-switch leads 2411 is connected to the solenoid of valve 2457 and the other one to a common ground of a power supply 2458 which in this example is a 12 volt on-board rechargeable battery. One lead of power supply 2458 is a hot current lead 2486 which is connected to a relay assembly 2275 and its other lead is a common ground 2485. One lead of the pair of lower switch leads 2412 is connected to a buzzer 2255 which is 12 volts DC and the other lead is connected to a lead of an LED 2274, which has a resister installed to allow it to operate off of 12 volts DC. The remaining lead of buzzer 2255 is connected the switched power lead 2410. The remaining lead of LED 2274 is connected to the common ground 2485 of power supply 2458. Float 2271 of float switch assembly 2272 rises to its upward position in response to the buoyancy provided by an adequate supply of fresh fluid 329 which closes the contacts of the upper micro-switch of float shaft 2273. When there is an adequate supply of fresh fluid 329, the used fluid reservoir 326 has been emptied, and fluid exchanger 2425 has been properly connected to the power steering system being serviced, the engine of the vehicle can be started. As soon as the used fluid flow reaches flow switch 2251 to close its contacts, the magnetic winding 2277 in relay assembly 2275 is activated to provide current to switched power lead 2410 which in turn allows switched power to be provided to the solenoid of valve 2457 because the contacts of the upper micro-switch of float switch assembly 2272 are closed in a series circuit with the solenoid of valve 2457. This places valve 2457 in its activated position 2491. When the level of fresh fluid 329 becomes depleted float 2271 drops to close the contacts of the lower micro-switch of the float shaft 2273 of float switch assembly 2272. This disconnects current from the solenoid of valve 2457 and provides current to energize buzzer 2255 and LED 2274. This places valve 2457 back to its spring loaded default position 2490. Buzzer 2255 and LED 2274 continue to be energized until the vehicle's engine is turned off which opens the electrical contacts of flow switch 2251. When LED 2274 is energized it gives off a bright and diffused blinking red light and when buzzer 2255 is energized it emits a loud 100 decibel pulsing warning tone. Fluid control valve 2457 is a two position valve with four fluid ports, a used fluid inlet port 2483, a used fluid outlet port 2481, a fresh fluid inlet port 2482, and a fresh fluid outlet port 2484. A used fluid conduit 2479 connects used fluid outlet port 2481 to used fluid inlet port 2450. A fresh fluid supply conduit 2480 connects reservoir outlet port 2453 to fresh fluid inlet port 2482. A used fluid conduit 2455 is sealingly secured to used fluid exchange hose 354 with hose clamp 117 at one end and connected to float switch 2251 at its other end. A used fluid conduit 2454 connects flow switch 2251 to used fluid inlet port 2483. A fresh fluid conduit 2356 is sealingly secured to fresh fluid exchange hose 361 with hose clamp 117 at one end and connected to fresh fluid outlet port 2484 at its other end. Fluid control valve 2457 is spring fed to return to a default mode when unpowered, and this default position 2490 provides fluid connection between used fluid inlet port 2483 and fresh fluid outlet port 2484 while blocking used fluid outlet port 2481 and fresh fluid inlet port 2482. When the solenoid of fluid control valve 2457 is activated by electric current, the valve is shifted to its fluid exchanging position 2491 which connects used fluid inlet port 2483 to used fluid outlet port 2481 while connecting fresh fluid inlet port 2482 to fresh fluid outlet port 2484. Fluid control valve 2457 has a 12 volt direct current (DC) electric solenoid (not shown) which is provided with two electrical wires, one of which is connected to a switched power lead of relay assembly 2275 and the other lead is connected in series to one lead of the upper micro-switch of float switch assembly 2272. A float switch assembly 2272 can be selected which has light duty contacts in its micro-switches, but that would require the use of a second relay to remove the current load from the contacts of the upper and lower micro-switches. FIG. 25 depicts an embodiment, fluid exchanger 2524 which has the same parts and parts arrangement except that it has some additional parts. FIG. 25 shows fluid exchanger 2525 connected in proper operative arrangement to the type of power steering system of FIG. 1, reservoir-pump combination 192. Cap adapter 789 is properly installed on filler neck 102 and its large male quick connect 790 is connected to the large female quick connect 367 of fresh fluid exchange hose 366 . The ⅜ male tube adapter 787 is inserted inside hose end 115 which has sealingly secured by hose clamp 117 after hose end 115 was removed from reservoir return port 116. The small male quick connect 788 of the ⅜ male tube adapter 787 is connected to the small female quick connect 355 of used fluid exchange hose 354. There is a female hose adapter 2598 which is comprised of a ⅜ inch internal diameter female hose 2599 and a small male quick connect 788. Female hose adapter 2598 is sealingly secured to port 116 with hose clamp 117 and connected to a small female quick connect 2557 of a fresh fluid vent hose 2526 which is connected to a fresh fluid reservoir auxiliary port 2557. A boost pump 2520 has been added to fresh fluid conduit 2356. This particular pump is not a positive displacement pump. Certainly a positive displacement pump of many different types could be used if of relatively high flow, higher than the typical approximate flow of up to 2 or more gallons per minute of most power steering units and properly controlled with a relief valve circuit set to relieve the pump at a relatively low pressure not too great to blow the cap adapter 789 off of the reservoir neck 102. A good pressure target to select is 5-7 psi but greater or lesser can be selected depending on the strength of the connectors used and the types of reservoirs which will be serviced, automotive, truck, bus, industrial hydraulic machines, etc. In this case a boost pump 2520 is a 12 volt powered kinetic pump typically referred to as a centrifugal pump. A centrifugal, kinetic pump is an appropriate choice because it is not self-priming but can be located underneath the fresh fluid reservoir 328 and doesn't need to be self-priming. In addition, centrifugal, kinetic pumps can be constructed and arranged to boost flow without restricting flow that is somewhat higher than the pump alone would deliver, and without adding additional cost by using a relief circuit. Description of the Operation of the Preferred Embodiment In the preferred embodiment, the fluid control valve 457 of FIG. 4 & 5 is used. Valve 457 is operated by float 572 with assistance of low pressure (also referred to as negative pressure) provided by the power steering pump at its inlet port. In an alternative embodiment shown in FIGS. 16-18, a fluid control valve is used which is operated by a float but also with assistance of the positive pressure provided by the power steering pump at its outlet port. In another embodiment shown in FIGS. 19-20, a fluid control valve is used which is operated by a float but also with assistance of the positive pressure provided by the power steering pump at its outlet port and the negative or low pressure provided by the power steering pump as its inlet port. FIGS. 7 & 9 show the fluid exchanger 325, the preferred embodiment in proper connective arrangement with the two main types of power steering systems in use today in passenger vehicles. FIG. 12 depicts the connection of special adapters to the power steering system of FIG. 11 to prepare it for connection to fluid exchanger 325. FIG. 14 depicts the connection of special adapters to the power steering system of FIG. 13 to prepare it for connection to fluid exchanger 325. FIG. 15 depicts the connection of special adapters to the power steering system of FIG. 13 in an alternative fashion to prepare it for connection to fluid exchanger 325. The preferred embodiment of the invention, fluid exchanger 325 is operated in the same manner for FIGS. 12, 14 & 15 as it is for FIGS. 7 & 9, and the alternative embodiment shown in FIGS. 16-24 can be connected to the power steering systems shown in FIGS. 1 & 2, and 11 & 13 just as fluid exchanger 325 can be connected to the power steering systems shown in FIGS. 1 & 2, and FIGS. 11 & 13. Each alternate embodiment can be connected and operated to exchange power steering fluid the same way as the preferred embodiment of FIGS. 4-6, since they have the same identical automatic functions for exchanging the fluid of power steering systems, consisting of an automatic fluid exchange starting feature, an automatic fresh and used fluid flow balancing feature, and an automatic stopping of the fluid exchange feature characterized by placing the fluid exchanger in a closed fluid circulation circuit where the power steering pump freely circulates its fluid between its outlet port and its inlet port without infusing and entrapping air in its fluid, a feature which allow the operator sufficient time to shut off the engine without air becoming infused and entrained in the fluid of the power steering system being serviced. Once the suitable adapters are properly connected to the type of power steering system of FIGS. 1 or 2 , any one of the alternative embodiments of the fluid exchanger as well as the preferred embodiment of FIGS. 4-6 can be quickly connected and operated. The power steering system shown in FIG. 7 is shown to be ready for the fluid exchange to be instituted which automatically begins when the engine of the vehicle is started. The exchanging of the fresh fluid 329 of the fluid exchanger 325 for the power steering system's used fluid 327 will be automatically stopped when the supply of fresh fluid 329 becomes depleted or if the vehicle's engine is turned off before that occurs. The preferred embodiment of fluid exchanger 325 is shown in proper operative position in FIG. 7 for exchanging the fluid of the traditional combination pump reservoir type of power steering system of FIG. 1, and is also shown in proper operative position in FIG. 9 for exchanging the fluid of the more modern type of power steering system of FIG. 2 which has its reservoir remotely positioned from the power steering pump. In FIG. 7, fluid exchanger 325 is shown in proper operative connection to the more traditional type power steering system shown in FIG. 1 in which reservoir 100 is combined with pump 105. Reservoir 100 has been converted to function like a large conduit filled with fluid rather than a reservoir which is partially filled with air which is normally vented to atmosphere through cap 103 of FIG. 1. This conversion has been accomplished by removing cap 103 of FIG. 1, separating hose end 115 from reservoir return port 116 and quickly plugging it with port plug 786, filling reservoir 100 to the top of filler neck 102 with fresh fluid, and then installing the non-vented cap adapter 789 on reservoir 100. If the fluid of the power steering system was burned or especially varnished, characterized by a dark discoloration and acrid varnish or burned odor noticeable by examining a sample of fluid 101 held in reservoir 100, the operator can alternatively choose to use a hand suction pump or other available device to suction the used fluid out of reservoir 100 before plugging reservoir return port 116 with port plug 786 and filling reservoir 100 to the top of filler neck 102 with fresh fluid. The operator then starts the vehicle's engine. See FIG. 7. This causes pump 105 to be activated by the revolutions of pulley 118 which result from the engine rotating belt 119 over it. This results in pump 105 communicating low pressure through its intake port to and through reservoir 100, and then to and through cap adapter 789, and then to and through fresh fluid exchange hose 366, and then communicated to inlet port/fresh fluid channel 464 shown in FIG. 4, and then finally communicated to the fresh fluid 329 at the bottom of reservoir 328 in close proximity to threaded top 468 of fluid control valve 457 of FIG. 4. Vented cap 333 of fresh fluid reservoir 328 allows normal atmospheric pressure to enter fresh fluid reservoir 328 and force fresh fluid 329 into and through inlet port/fresh fluid channel 464 of valve slide 461 as long as float 472 is upward enough to keep inlet port/fresh fluid channel 464 open inside the fresh fluid reservoir 329. This atmospheric pressure applied to the fresh fluid 329 causes it to be delivered out of the fresh fluid reservoir 328, into and through flow control valve 457, into and through fresh fluid exchange hose 366, into and through cap adapter 789, into and through reservoir 100, into and through reservoir outlet conduit 106, and then into inlet port 111 of pump 105 where it is pressurized by pump 105 to be delivered to steering gear mechanism 112 through pressure conduit 110 (see FIG. 1). While this is occurring the operator turns the steering wheel to the left fully and then to the right and then back to center (or in reverse order) in order to allow fluid 329 which has been pressurized to approximately fully flush out essentially all the internal passages and cavities of steering gear mechanism 112. While pump 105 is pressurizing and delivering fresh fluid 329 to steering gear mechanism 112, the pressurized fluid flow of pump 105 is also forcing the fluid passing through steering gear mechanism 112 to flow into and through fluid return conduit 114, and then into and through hose end 115, and then into and through ⅜ male tube adapter 787, and then into and through used fluid exchange hose 354, and then into and through street tee 351 and check valve 350 to be deposited into used fluid receiver 327, while simultaneously displacing an approximately equal volume of air through vent 331. The simultaneous and approximately equivalent rates of flow and volumes of flow of fresh fluid 329 out of fresh fluid reservoir 328 and used fluid 327 into used fluid receiver 326, continues until the supply of fresh fluid 329 contained in fresh fluid reservoir 328 is depleted. When the supply of fresh fluid 329 is depleted, float 472 drops to its lower position in fresh fluid reservoir 329 which causes valve slide 461 (shown in FIG. 5) to move to and rest in its downward most position which brings seal 465 into close positioning with the threaded top end 468 of valve body 459. This close position of seal 456 enables the low pressure provided from pump 105 through fresh fluid exchange hose 466 to exert enough force to pull valve slide 461 downward to adequately pinch seal 465 between the top side of threaded end 468 and lower side of collar 476 which establishes an essentially air and fluid tight seal between control valve 457 and fresh fluid reservoir. Not only does the drop of valve slide 461 cause the sealing off of fresh fluid exchange hose 466 from fresh fluid reservoir 328, it also simultaneously causes side port 499 of slide 461 (FIG. 5) to align with hose barb 458. This connects the used fluid hose 356 with the inlet port/fresh fluid channel 464 establishing a closed fluid circulation circuit for the power steering system. This allows fluid delivered by pump 105 to flow into and through used fluid exchange hose 354, and to then enter and flow through fresh fluid exchange hose 366 through the connection established within the fluid control valve 457, instead of flowing into the used fluid receiver 326. As the power steering system continues to operate in this closed fluid circulation circuit, the low pressure provided by pump 105 which is communicated through fresh fluid exchange hose 366 in coordination with the weight of used fluid 326 together cause check valve 350 (FIG. 3) to seal off the used fluid reservoir 326 from communicating with either the inlet side or outlet side of pump 105. Upon depletion of the supply of fresh fluid 329, which causes valve slide 461 to drop to it lower position, magnet 469 of FIG. 4 becomes positioned in line with magnetically operated micro-switch 462 which results in the closing of its electrical contacts. This closing of the contacts of micro-switch 462 provides electricity from a small 9 volt battery (not shown) to power a blinking red LED (not shown) and loud cycling buzzer (not shown) through an on/off toggle switch (not shown) which was flipped to its on position before the fluid exchange was started, after filling of the fresh fluid reservoir 328 with the proper amount of fresh fluid 329 and emptying the used fluid receiver 326 of used fluid 327 through ball valve 342 by use of valve operating lever 343. The loud warning tone provided by the cycling buzzer and the blinking red LED alerts the operator when the fluid exchange is complete and the power steering pump is circulating fluid in a closed fluid circulation circuit through fluid exchanger 325. The operator does not need to rush needlessly to turn off the vehicle's engine since pump 105 is freely circulating the now essentially fresh fluid 329 in this closed fluid circulation circuit from its outlet port to its inlet port without infusing air which would become quickly entrained. In non-quick lube service centers and even in some quick lube service centers where customers leave the vehicle while it is being serviced to sit in a waiting room, the service technician who connects and operates the fluid exchanger often must be the same individual who turns the steering wheel from right to left and back to the middle. Because the fresh fluid typically becomes depleted very rapidly (often in 15 to 20 seconds or less), the action of the float operated fluid control valve is quite necessary because the operator typically would have difficulty watching the fresh fluid supply closely enough to be able to stop the engine in time before air would be pumped into the power steering pump's inlet port to become entrained in the fluid. Even if the operator had an associate helping him by sitting behind the vehicle's steering wheel, without fluid exchanger 325 having fluid control valve 457 to automatically establish a closed loop circulation circuit, it would still be very difficult for the operator to be able to watch the fresh fluid level drop to depletion and tell the other person to turn off the engine, and then to have that other person turn off the engine quickly enough to prevent air from becoming entrained into the power steering fluid. It is especially desirable for the fluid exchanger 325 to have a float operated fluid control valve if the operator prefers to use a very compact unit which holds only as much fresh fluid as is needed for one fluid exchange and desires to use as much of the fresh fluid contained in the fresh fluid reservoir 328 as possible without having to worry about pumping air into the pump's intake port or having to unduly rush to stop the vehicle's engine. After the operator turns off the engine, he(she) proceeds to disconnect fresh fluid exchange hose 466 and used fluid exchange hose 354 by releasing large female quick connect 467 and small female quick connect 355, respectfully. Cap adapter 789 and ⅜ male tube adapter 787 are removed. Port plug 786 is then removed and hose end 115 is quickly pushed onto reservoir return port 116 and sealingly secured with hose clamp 117. The engine of the vehicle is then started and the fluid level in reservoir 100 is checked by using the reservoir's cap 103 which has an integral dipstick 104. If necessary the fluid level is adjusted up or down to reside at proper operating level as indicated on dipstick 104, typically using the cold level reading, since the newly exchanged fluid typically has not yet reached normal operating temperature. Since fluid expands as it is heated, the cold mark is lower than the hot mark. Cap 103 is replaced on reservoir 100 and the power steering system is visibly checked for any leaking connections or leaks. The power steering fluid exchange procedure for FIG. 7 is now complete. In FIG. 9, the power steering system fluid exchanger 325 is connected to the more recent type of power steering system of the type shown in FIG. 2 in which reservoir 200 is remotely positioned from the pump. Once the adapters of FIG. 10 are connected as shown in FIG. 9, the fluid exchange is conducted exactly as described above for FIG. 7. Once the fluid exchange is completed the flashing red LED and warning tone are activated by magnetically operated micro-switch 462. This alerts the operator to turn off the engine. The large female quick connect 367 of fresh fluid hose 366 is disconnected from the large male quick connector of ⅝ male tube adapter 991. The small female quick connect 355 of used fluid hose 355 is disconnected from the large male quick connector of ⅜ male tube adapter 787. The ⅝ male tube adapter 991 and the ⅜ male tube adapter 787 are disconnected from pump supply hose 208 and hose end 215, respectively after removing one hose clamp 117 from each. Pump supply hose 208 and hose end 215 are then reconnected to their respective reservoir ports, reservoir return port 206 and reservoir outlet port 216 using one hose clamp 117 each. Reservoir 200 is then filled to its cold level mark with fresh fluid. The engine is started and idled and the fluid level is rechecked and topped off with additional fresh fluid if needed. Cap 203 is replaced onto filler neck 202 and the power steering system is visibly checked for any leaking connections or leaks. The power steering fluid exchange procedure of FIG. 9 is now completed. In FIG. 11 reservoir 1000 is also a reservoir that is remotely arranged from the power steering pump. This particular reservoir is from a Ford Explorer and its pump supply hose 1008 is usually more difficult than average to reach due to the type of hose clamp used. The operator has the option of removing a few bolts and then removing the reservoir to allow the connection method of FIG. 9 to be used, or can use the connection method of FIG. 12 in which the ⅜ male tube adapter 787 is sealingly connected to hose end 1015, and reservoir cap adapter 1185 is snugly pushed into filler neck 1003. The fresh fluid exchange hose 366 and the used fluid exchange hose 354 of fluid exchanger 325 have been suitably connected to the power steering system by connecting large female quick connect 367 of fresh fluid exchange hose 366 to the large male quick connect 790 of cap adapter 1185, and by connecting the small female quick connect 355 of used fluid exchange hose 354 to the small male quick connect 788 of the ⅜ male tube adapter 787. The vehicle's engine is then started and is run until the red LED lights up and blinks and the cycling buzzer's warning tone alert the operator that the fluid exchange is finished. The engine is then turned off, the fluid exchanger 325 is removed by releasing the female quick connects 355 & 367 from the adapters they are connected to, and then removing the adapters, and then reconnecting hose end 1015 back onto reservoir return port 1016 and replacing cap 1002 into filler neck 102 after topping off or adjusting the fluid level of reservoir 1000 if necessary. In FIG. 13 reservoir 1200, the power steering system is the more traditional combination reservoir-pump type of FIG. 2 in which reservoir 1200 is combined with pump 1205, except that the reservoir is translucent plastic and there are cold and hot fluid level marks on the sidewall. FIG. 14 shows how to connect the proper adapters to the power steering system of FIG. 13. In order to connect the fluid exchanger 325, cap 1203 of FIG. 13 is removed and replaced with the non-vented cap adapter 1395 of FIG. 14. Hose end 1215 is separated from reservoir return port 1216 and quickly plugged with port plug 786. The ⅜ male tube adapter is pushed into hose end 1215 and sealingly secured with hose clamp 117. Reservoir 1200 is then filled to the filler neck 1202 with fresh fluid. If the fluid of the power steering system was burned or especially varnished, characterized by a dark discoloration and acrid varnish or burned odor, the operator can alternatively choose to use a hand suction pump or other available device to suction the used fluid out of reservoir 100 before separating hose end 1215 from reservoir return port 1216 and then plugging reservoir return port 1216 with port plug 786. Reservoir 1200 is then filled to the top of filler neck 1202 with fresh fluid and the non-vented cap adapter 1395 is secured into proper position on filler neck 1202 by matingly engaging its locking tabs with the locking grooves in filler neck 1202. The used fluid receiver 327 of fluid exchanger 325 has been emptied of all but a small remainder of used fluid 327 from the prior fluid exchange, and its fresh fluid reservoir 329 has also been filled with approximately three quarts of fresh fluid. The fresh fluid exchange hose 466 and the used fluid exchange hose 354 of fluid exchanger 325 have been suitably connected to the power steering system by connecting large female quick connect 467 of fresh fluid exchange hose 466 (FIG. 3) to the large male quick connect 790 of cap adapter 1395, and by connecting the small female quick connect 355 of used fluid exchange hose 354 FIG. 3) to the small male quick connect 788 of ⅜ male tube adapter 787. The engine is started and the fluid exchange is instituted and completed automatically by the power steering fluid exchanger. In FIG. 15, the power steering system is the same as shown in FIGS. 13 & 14 but is shown with an alternate connection method. Cap 1203 is replaced by a non-vented cap adapter 1495 which has a pair of O'rings, an O'ring 1496 and an O'ring 1497, when provide an effective vent-free seal when cap 1203 is connected to filler neck 1202 by properly engaging cap retainer ring 1204 and then tightening cap 1203. Reservoir 1200 has been filled with fluid to cause it to function like a large conduit filled with fluid rather than a reservoir which is partially filled with air. Hose end 1215 is then separated from reservoir return port 1216. A ⅜ hose adapter 1498 has a female ⅜ hose at one end and the small male quick connect 790 at the other. This adapter 1498 is installed onto reservoir return port 1216 by pushing its ⅜ hose onto port 1216 and sealingly securing it with hose clamp 117. Reservoir 1200 is filled to the top of filler neck 1202 with fresh fluid. If the fluid of the power steering system was burned or especially varnished, characterized by a dark discoloration and acrid varnish or burned odor, the operator can alternatively choose to use a hand suction pump or other available device to suction the used fluid out of reservoir 1200 before plugging reservoir return port 1216 with port plug 786 and filling reservoir 1200 to the top of filler neck 1202 with fresh fluid. The ⅜″ internal diameter male tube adapter is pushed into hose end 1215 and sealingly secured with hose clamp 117. The used fluid receiver 327 of fluid exchanger 325 has been emptied of all but a small remainder of used fluid 327 from the prior fluid exchange, and its fresh fluid reservoir 329 has also been filled with approximately three quarts of fresh fluid. The fresh fluid exchange hose 466 and the used fluid exchange hose 354 of fluid exchanger 325 have been suitably connected to the power steering system by connecting large female quick connect 467 of fresh fluid exchange hose 466 (FIG. 3) to the large male quick connect 790 of adapter 1495, and by connecting the small female quick connect 355 of used fluid exchange hose 354 (FIG. 3) to the small male quick connect 788 of ⅜ male tube adapter 787. The engine is started and the fluid exchange is automatically instituted and completed. Description of the Operation of Alternative Embodiments FIGS. 16-18 depict an alternative embodiment of the power steering fluid exchanger which is also powered by the low pressure provided by the power steering pump at its inlet port but which has a float operated fluid control valve 1557 whose operation is assisted by the positive fluid pressure provided by the outlet port of the power steering pump. In FIGS. 16 & 17 fluid control valve 1557 does not have a fresh fluid supply port provided integrally to its valve slide as does the fluid control valve of FIGS. 4-6. As long as float 1570 is not in its lower position, fresh fluid 329 is supplied to the power steering pump under power of the low pressure provided by the pump through its inlet port. This causes fresh fluid 329 to be delivered from the fresh fluid reservoir into and through fresh fluid supply port 1523, then into an through fresh fluid supply conduit 1524, into and through fresh fluid inlet port 1580, into and through fluid channel 1599, into and through fresh fluid delivery port 1500, into and through fresh fluid conduit 1566, and then into fresh fluid exchange hose 366 to eventually enter the inlet port of the power steering pump, with all the fresh fluid flow being powered by the low pressure provided by the power steering pump through its inlet port. The used fluid 327 is delivered into and through used fluid exchange hose 354, into and through used fluid conduit assembly 1554, and then into and through check valve 350 to be deposited in used fluid receiver 326. See FIG. 17. As the supply of fresh fluid supply 329 becomes depleted, float 1572 drops to its lower position under the force of its own weight along with the weight of the valve slide 1561, float shaft 1570 and its retainer nut 473, as well as the effects of used fluid now being able to flow into a power assist port 1502. As valve slide 1561 begins to move downward toward its lower position, used fluid inlet port 1548 is no longer blocked by the left side of valve slide 1561 and the pressurized used fluid 327 provided by the power steering pump is now free to pass through used fluid inlet port 1548 and into to fluid channel 1599 of valve slide 1561 to flow into and through the fresh fluid delivery port 1500 to flow into and through fresh fluid conduit 1566 and then into and through fresh fluid exchange hose 366. This pressurized used fluid 327 transmits fluid pressure through fluid power port 1502 to apply pressure to the top side of valve slide 1561 which then forces the valve slide 1561 to the end of its travel downward which drives collar 1576 downward against seal 1565, squeezing it against the threaded top end 1568 of valve body 1559. This establishes an essentially air and fluid tight seal between the fresh fluid reservoir 328 and valve bore 1583. Simultaneous to the depletion of the supply of fresh fluid 329 and the harnessing of the used fluid power provided by the power steering pump at the top side of valve slide 1561, float ball 1521 drops to its lower position in wire float cage 1522 where the low pressure provided by the power steering pump at its inlet port communicates with fresh fluid supply port 1523 to pulls float ball 1521 snugly into fresh fluid supply port 1523 forming an essentially air and fluid tight seal between the fresh fluid reservoir 328 and fresh fluid supply conduit 1524. Simultaneous to this dropping of valve slide 1561 to its lower position and float ball 1521 establishing an essentially air and fluid tight seal to fresh fluid supply port 1523, the fluid control valve 1557 directs pressurized used fluid 327 to be delivered into and through itself (fluid control valve 1557) instead of into used fluid receiver 326. The used fluid 327 is delivered through used fluid inlet port 1548, and flows into and through fluid channel 1599 and then into and through fresh fluid delivery port 1500 to be delivered into fresh fluid conduit assembly 1566 and fresh fluid exchange hose 366 to return to the inlet port of the power steering pump. The fluid exchanging part of the service procedure has been completed, and in most cases the fluid being delivered out of the outlet port of the power steering pump contains moderately high to very high proportion of fresh fluid to used fluid. When the fluid exchanger enters its closed fluid circulation circuit, the fluid flows from the outlet port of the power steering pump, into and through the steering mechanism, into the used fluid exchange hose to enter and flow through the fluid control valve 1557 and then to flow through the fresh fluid exchange hose to the inlet port of the power steering pump. When the fluid control valve 1557 establishes such a closed fluid circulation circuit, it also simultaneously seals off the fresh fluid reservoir and the used fluid reservoir from this closed loop fluid circulation circuit. The low pressure provided by the power steering pump along with the weight of the used fluid 327 held in used fluid reservoir 326, pulls check valve 350 downward with sufficient force to establish an essentially fluid tight seal, preventing the typically dirty used fluid 327 from entering the fresh fluid supply conduit 1524 to contaminate the essentially fresh fluid which is circulating in the closed loop fluid circulation circuit. FIGS. 19 & 20 depict a mechanical/hydraulic fluid control valve of an alternative embodiment which is float operated and assisted by both negative and positive pressures provided by the power steering pump. FIG. 19 shows the embodiment with the valve slide 1961 of fluid control valve 1957 held in its upward position by the buoyancy of float 1572 in an adequate supply of fresh fluid. This establishes a fluid exchanging condition by connecting used fluid inlet port 1948 to used fluid outlet port 1950, and by connecting fresh fluid inlet port 1980 to fresh fluid outlet port 1900. Fluid exchanger 1925 is shown in the middle of a fluid exchange. Used fluid 327 is pumped from the power steering pump, through the steering mechanism, and into the used fluid exchange hose 354 where it passes through used fluid conduit assembly 1955, used fluid inlet port 1948, side fluid channel 1998, used fluid outlet port 1950 and into and through check valve 350 to be deposited in used fluid receiver 326. The power steering pump generates low (negative) pressure at its outlet side which is communicated into and through fresh fluid exchange hose 354, into and through fresh fluid conduit assembly 1956, through fresh fluid outlet port 1900, into and through cross fluid channel 1999, through fresh fluid inlet port 1980, into and through used fluid conduit 1954, and into fresh fluid supply port 1523. This transmission of low pressure from the inlet port of the power steering pump to fresh fluid supply port 1523 causes fresh fluid to be pumped under power of atmospheric pressure toward the source of low pressure. Fresh fluid flows out of fresh fluid reservoir 328, through fresh fluid supply port 1523, into and through fresh fluid supply conduit 1924, through fresh fluid inlet port 1980, into and through cross fluid channel 1999, through fresh fluid outlet port 1900, into and through fresh fluid conduit assembly 1956, and then into and through fresh fluid exchange hose 366 to the inlet port of the power steering pump. Used fluid 327 is discharged and held in used fluid receiver 326 after pressure is applied to it by the power steering pump. Used fluid 327 is pumped into and through the power steering mechanism to enter the used fluid exchange hose 354. Used fluid 327 then flows into and through used fluid conduit assembly 1955, through used fluid inlet port 1948, into and through side fluid channel 1998, through used fluid outlet port 1950, into and through used fluid conduit 1954 to pass through check valve 350 into the used fluid receiver 326. The used fluid 327 flows into used fluid receiver 326 at the same approximate rate of flow as the fresh fluid 329 flows out of the fresh fluid reservoir 328. FIG. 20 depicts the end result of the balanced flow of fresh fluid 329 and used fluid 327. The level of fresh fluid 329 has dropped until it has become depleted. As the fresh fluid nears depletion, float 1572 drops in fresh fluid reservoir 1572 moving valve slide 1961 downward. As valve slide 1961 begins to move fluid power port 1902 opens and creates a cavity at the top side of valve slide 1961 which is filled and lengthened with pressurized used fluid 327 entering under the positive pressure provided by the power steering pump. This working fluid entering fluid power port 1902 and the positive pressure it transmits applies downward force to slide 1961 and augments the force applied by the additive weight of float 1572, retainer nut 473, float shaft 1570, and valve slide 1961 which increases as the fresh fluid level drops fully and all buoyancy is lost. As valve slide 1961 drops the solid section above cross fluid channel 1999 drops below fresh fluid outlet port 1900 and fresh fluid inlet port 1980, negative pressure is provided to cross fluid channel 1999 and valve slide 1961 through power port 1906 and fresh fluid conduit 1956. This negative pressure applies additional downward force to valve slide 1961 and assists in the last part of its movement downward and once valve slide nears the end of its downward stroke, the negative pressure applied at power port 1906 helps keep seal 1565 squeezed between collar 1576 and threaded top end 1968 to be sealed essentially fluid and air tight. As the level of fresh fluid becomes depleted, float ball 1521 moves to fit tight into the top side of fresh fluid supply port 1523, creating an air and fluid tight seal between fresh fluid supply conduit 1924 and the fresh fluid reservoir 328. This along with the closing off of the fresh fluid reservoir from valve bore 1983 as a result of the squeezing of seal 1565, and the closing off of the used fluid reservoir from used fluid conduit 1954 by check valve 350 under the weight of used fluid 327 and the low pressure provided by the power steering pump at its inlet port, fluid now flows in a closed fluid circulation circuit which has been established between the outlet port of the power steering pump and its inlet port. FIG. 21 depicts a mechanical/hydraulic fluid control valve of an alternative embodiment which is float operated and is very basic and less costly. FIG. 21 shows fluid control valve 2157 with its valve slide in its upward position, a response to an adequate level of fresh fluid 329. Valve 2125 functions effectively but does not typically seal well enough at the end of the fluid exchange for the vehicle to be left running for more than a short time with its power steering pump circulating fluid in a closed fluid circulation circuit. This valve will provide significantly less time to shut the engine than the other more deluxe, mechanical/hydraulic fluid control valves such as those shown in FIGS. 4-5, 16-18 & 19-20 which can provide a significantly longer period of time for the operator to shut the vehicle's engine off, usually as long as desired by the service equipment operator. The sealing off of valve bore 2183 from fresh fluid reservoir 328 when the supply of fresh fluid 329 becomes depleted is provided only by the additive weight of valve slide 2161, float shaft 1570, float 1572 and retainer nut 473 applying force to rim 1576 to pinch seal 1565 with no assistance by the low pressure or positive pressure of the power steering pump except at check valve 350. When valve slide 2161 is in its upward position, the fluid communication between used fluid inlet port 2148 and used fluid outlet port 2180 is blocked, allowing used fluid 327 to flow under pressure provided by the power steering pump from used fluid exchange hose 354 into and through used fluid conduit 2154 to pass through check valve 350 to be deposited in used fluid receiver 326. Fresh fluid 329 is pumped out of fresh fluid reservoir 328 through fresh fluid supply port 1523, into and through fresh fluid supply conduit 2124, and into and through fresh fluid exchange hose 366 to be delivered to the inlet port of the power steering pump. As with all the other embodiments the fresh fluid 329 is exchanged for the power steering systems used fluid 327 in approximately equivalent flow rates and volumes. As the level of fresh fluid 329 becomes depleted, float 1572 loses buoyancy in fresh fluid 329 and drops to its downward position with seal 1565 held against the threaded top end 2168 by collar 1576. When float 1572 drops it carries valve slide 2161 to its lower position in valve bore 2183 while fluid is vented upward through fluid vent 2103 preventing valve slide 2161 from become hydro-locked. The established fluid communication between used fluid inlet port 2148 and used fluid outlet port 2180. The low pressure provided by the power steering pump through fresh fluid hose 366 and into fresh fluid supply conduit 2124 causes float ball 1521 to seal tightly against fresh fluid supply port 1523, and causes check valve 350 to seal off the used fluid receiver 326 from used fluid conduit 2154. FIG. 22 depicts an alternative embodiment with a float operated electrical/hydraulic fluid control valve which is a two position, dual port electric solenoid valve. FIG. 22 is shown with the solenoid of valve 2257 energized by relay assembly 2275 and float switch assembly 2272 to block fluid communication between inlet port 2261 and outlet port 2262. Float switch 2272 is in its upward position in which the contacts of its upper micro-switch are closed by the adjacent proximity of the pair of magnets 2269. The internal contacts of flow switch 2251 are closed by the flow of fluid through it. When the contacts of flow switch 2251 are closed the magnetic winding 2277 of relay assembly 2275 is energized to provide current to switched power lead 2210. The upper switch leads 2211 of float switch 2272 are wired in a series circuit with the solenoid of valve 2257 and when float 2271 is in its upward position due to an adequate level of fresh fluid 329, the solenoid of valve 2257 is energized by current. This turns on valve 2257 and blocks fluid communication between the used fluid conduit assembly 2254 and the fresh fluid conduit assembly 2556, establishing a fluid exchanging condition in fluid exchanger 2225. This fluid exchanging condition of fluid exchanger 2225 is characterized by a fluid connection between fresh fluid conduit assembly 2556 and the fresh fluid reservoir 328, and simultaneous fluid second connection between used fluid conduit assembly 2254 and the used fluid receiver 326. When the level of fresh fluid 329 becomes depleted, the electrical contacts of the upper micro-switch of float switch 2272 become disconnected and current is removed from the solenoid of valve 2257. The return spring of valve 2257 places it in its default mode which establishes a fluid connection between used fluid exchange hose 354 and fresh fluid exchange hose 366, thereby establishing a closed fluid circulation circuit between the outlet and inlet ports of the power steering pump. This closed fluid circulation circuit is closed off from fresh fluid reservoir 329 and used fluid receiver 326 due to the low pressure provided by the power steering pump pulling float ball 1521 sealingly into fresh fluid supply port 2253 causing the sealing off of the fresh fluid reservoir 329 by pulling check valve 350 closed in coordination with the weight of the used fluid 327. While fluid exchanger 2225 is in this closed fluid circulation circuit with the power steering operative under power of the vehicle's engine, the blinking red LED 2274 and the pulsing 100 decibel buzzer 2255 are activated. LED 2274 and buzzer 2255 alert the service equipment operator that the fluid exchange is now completed and the vehicle's engine can be turned off. If the power supply for fluid exchanger 2225 becomes interrupted for any reason while fluids are being exchanged, valve 2257 returns to its spring fed default position which establishes communication between used fluid inlet port 2261 and used fluid outlet port 2262. This keeps air from being infused and entrained into the power steering fluid if a power outage occurs for any reason. As soon as the engine is turned off, the contacts within flow switch 2251 open to shuts-off current through magnetic winding 2277, which removes current from the switch power lead which in turn removes the electrical current supplying LED 2274 and buzzer 2255, which turns them off disconnects power supply 2258. FIG. 23 depicts an alternative embodiment with a float operated electrical/hydraulic fluid control valve which is a two position, triple port electric solenoid valve. FIG. 23 is shown with the solenoid of valve 2357 energized in response to the upward position of float switch assembly 2372 to block fluid communication between in-activated inlet port 2361 and common outlet port 2362, while establishing fluid communication between common port 2362 and activated inlet port 2263. Float switch 2272 is in its upward position in which the contacts of its micro-switch have been closed by the proximity of the pair of magnets 2269 which caused current to be provided to energize the solenoid of valve 2357. If heavy duty contacts are used in the micro-switch of float switch assembly 2372, a relay is not necessary and float switch assembly 2372 can be wired in series circuit with a 12 volt DC onboard battery supply and a lighted on-off toggle switch. If light duty contacts are used in the micro-switch of float switch assembly 2372, use of a relay is necessary, using float switch assembly 2372 as a trigger to energize that relay to provide switched power to valve 2357 without the current load being applied to the light duty contacts of the micro-switch which could damage them. After the service equipment operator has filled the fresh fluid reservoir 328 with an adequate supply of fresh fluid 329 and emptied the used fluid receiver 326 of used fluid 327, fluid exchanger 2325 is connected to the power steering system to be serviced using the proper adapters required. The engine is started to render the power steering system operative which automatically starts the fluid exchange and the steering wheel is rotated to the left all the way and then to the right all the way and then back in quick succession and in reverse order if so desired. Used fluid 327 is discharged into used fluid receiver 326 from used fluid exchange hose 354 under positive fluid power provided by the power steering pump at its outlet port while fresh fluid 329 is delivered out of fresh fluid reservoir 329 and into the fresh fluid exchange hose 366 under low pressure power provided by the power steering pump at its inlet port. This exchange of the fresh fluid 329 of fluid exchanger 2325 for the used fluid 327 of the power steering system occurs with the rates of flow and volumes of flow of the fresh fluid 329 and the used fluid 327 being approximately equivalent due to the control provided by the power steering pump. This fluid exchange continues until the supply of fresh fluid 329 becomes depleted which causes float 2371 to move to its downward position resulting in the disconnection of current to the solenoid of valve 2357 which allows valve 2357 to return to its default position under the power of the spring contained within valve 2357. This results in the establishing of a fluid connection between used fluid conduit assembly 2354 and fresh fluid conduit 2356 and the simultaneous disconnection of fresh fluid supply conduit 2324 from the fresh fluid reservoir 329 and the disconnection of the conduit assembly 2354 from the used fluid reservoir 326. This establishes a closed circuit fluid circulation circuit between the outlet and the inlet ports of the power steering pump. This closed circuit fluid circulation circuit provides time for the service equipment operator to turn of the engine of the vehicle without rushing or worrying about infusing air into the power steering system to become entrained. If the power supply for fluid exchanger 2325 becomes interrupted for any reason while fluids are being exchanged, valve 2357 returns to its spring fed default position 2490 in which communication is established between inactivated inlet port 2361 and common outlet port 2362 with activated inlet port 2263 closed. This keeps air from being infused and entrained into the power steering fluid if a power outage occurs for any reason. FIG. 24 depicts an alternative embodiment, fluid exchanger 2425, which has a float operated electrical/hydraulic fluid control valve which is a two position, four port electric solenoid valve. A valve with this port and flow configuration is manufactured in several forms ranging from small spool valves inserted into machined valve bodies to very heavy duty spool valves which are operated by electric solenoids or are pilot operated by fluid or compressed air. An especially well designed and moderately priced 2 position-4 way cartridge spool valve and valve body combination with an easily replaceable solenoid which can have one of a number of voltages selected is currently manufactured by HydraForce and is an appropriate choice for this valve. Of course, one could use a much larger spool valve for a fluid control valve or even a small custom made one, which can be designed to be pilot operated which can have a mechanical float attached to its remotely located pilot valve for remotely controlling the spool's position in the control valve, using the fluid circuit's fluid power generated by the fluid circuit's pump as low pressure from its inlet port or as positive pressure from its outlet port. FIG. 24 is shown with the solenoid of valve 2457 energized by relay assembly 2275 and float switch assembly 2272 to block fluid communication between used fluid inlet port 2483 and fresh fluid outlet port 2484. Float switch 2272 is in its upward position in which the contacts of its upper micro-switch are closed by the adjacent proximity of the pair of magnets 2269. The internal contacts of flow switch 2251 are closed by the flow of used fluid 327 through it. When the contacts of flow switch 2251 are closed the magnetic winding 2277 of relay assembly 2275 is energized to provide current to switched power lead 2210. The upper switch leads 2211 of float switch 2272 are wired in a series circuit with the solenoid of valve 2257 and when float 2271 is in its upward position due to an adequate level of fresh fluid 329, the solenoid of valve 2257 is energized by current. This turns on valve 2257 and blocks fluid communication between the used fluid conduit assembly 2254 and the fresh fluid conduit assembly 2356, establishing a fluid exchanging condition in fluid exchanger 2225. This fluid exchanging condition of fluid exchanger 2225 is characterized by a fluid connection between fresh fluid conduit assembly 2356, fresh fluid supply conduit 2480 and the fresh fluid reservoir 328, and simultaneous second fluid connection between used fluid conduit assembly 2255, flow switch 2251, used fluid conduit 2454, used fluid conduit 2479 and the used fluid receiver 326. When the level of fresh fluid 329 becomes depleted, the electrical contacts of the upper micro-switch of float switch 2272 become disconnected and current is removed from the solenoid of valve 2257. The return spring of valve 2257 places it in its default mode, port configuration 2490 which establishes a fluid connection between used fluid exchange hose 354 and fresh fluid exchange hose 366 while blocking used fluid outlet 2481 and fresh fluid inlet port 2482, thereby establishing a closed fluid circulation circuit between the outlet and inlet ports of the power steering pump. While fluid exchanger 2425 is in this closed fluid circulation circuit with the power steering pump rendered operative under power of the vehicle's engine, the blinking red LED 2274 and the pulsing 100 decibel buzzer 2255 are activated. LED 2274 and buzzer 2255 alert the service equipment operator that the fluid exchange is now completed and the vehicle's engine can be turned off. If the power supply for fluid exchanger 2425 becomes interrupted for any reason while fluids are being exchanged, valve 2457 returns to its spring fed default position 2490 which establishes fluid communication between used fluid inlet port 2483 and fresh fluid outlet port 2484. This keeps air from being infused and entrained into the power steering fluid if a power outage occurs for any reason. Additionally, it may be appreciated that the present invention may find further applicability to fluid exchange devices outside of the automotive or transportation industries. For example, the fluid exchanger could be readily adapted to exchange the fluid of any hydraulic circuit by removing its reservoir and positioning the exchanger approximately at or above the level of the pump's negative pressure fluid inlet or suction conduit which supplies the hydraulic system's pump. In addition, an auxiliary demand pump can be arranged to the fresh fluid exchange hose (or conduit) to assist and insure that the fluid inlet line stays supplied with fresh fluid even if the fluid exchanger is positioned below the level of the fluid inlet line of the hydraulic system's pump, below the whole hydraulic system, or even located at a distance from the hydraulic system's pump which would typically be farther than the power of the negative pressure provided from the pump's inlet would normally support. The pressure and delivery of the fluid pumped from the fluid exchanger's fresh fluid reservoir through the auxiliary pump can be controlled and regulated in a number of suitable ways. An adjustable automatic relief valve circuit can be added to the auxiliary pump to bypass fluid from it's outlet port back into its inlet port or the fresh fluid reservoir, and can be set to provide a pressure high enough to keep the hydraulic system's pump supplied. Various arrangements and types of auxiliary pumps can be arranged to the fresh fluid exchange hose (conduit) which will automatically provide boost when the fluid pressure drops below a selected minimal setting. As long as the connections are secure and fluid and air tight between the fluid exchanger's fresh fluid exchange hose (conduit) and the hydraulic pump's low pressure supply conduit, and between the fluid exchanger's used fluid hose (conduit) and the hydraulic pump's return conduit to its reservoir (which has been disconnected), the overall pressure of the fresh fluid delivered to the hydraulic pump's low pressure supply conduit can be substantially greater than occurring in normal operation without harming the hydraulic pump or hydraulic system since the hydraulic pump will typically only ingest fluid within a certain given range of flow rates depending on the temperature of the fluid. Using the fluid changer with an auxiliary boost pump in this manner removes the need for any mechanism to balance the fresh and used fluid flow rates and volumes to be approximately equivalent, since the hydraulic pump provides the necessary regulation. A boost pump may be applied to boost the pressure and delivery of fresh fluid through the fresh fluid exchange hose and a fluid vent can be provided at the adapter for connecting the fresh fluid exchange hose to the low or negative pressure, suction conduit of the inlet side of the circuit being serviced. This fluid vent is then connected by an additional return conduit to vent back into the fresh fluid reservoir. In this way adequate fresh fluid can be supplied to a fluid circuit's reservoir which has been sealed or directly connected to the circuit's low pressure pump inlet side conduit without having to use a demand type pump with an automatic shut-off. This method also allows the fluid exchanger to be remotely positioned at any level including floor level and allows the use of a much larger fresh fluid reservoir and used fluid receiver. The alternative embodiment of FIG. 25, fluid exchanger 2525 operates in substantially the same way as the alternative embodiment of FIG. 24 except that a boost pump 2520 has been added to fresh fluid conduit 2356. When fluid exchanger 2525 is connected, the vehicle's engine is started. This renders the power steering pump operative and delivers used fluid to circulate through used fluid exchange conduit 354 to start to flow back through fresh fluid conduit 2356 which then triggers flow switch 2251 which in turn energizes the magnetic winding 2277 of relay 2275 which energizes switched power lead 2410. Due to the position of float switch 2272, pump 2520 is energizes as fluid control valve 2457 is shifted from its 2490 position to its 2491 position (as shown if FIG. 25). This causes used fluid to be delivered from hose end 115 into and through used fluid exchange hose 354 and then into the used fluid receiver 326 and fresh fluid to be delivered from the fresh fluid reservoir to reservoir 100 of the power steering system at a rate of flow somewhat higher than the rate at which is pumped by pump 105 of the power steering system. This excess fresh fluid 329 which enters reservoir 100 of the power steering system is vented back to the fresh fluid reservoir 328. Fluid exchanger 2525 of FIG. 25 shows the use of an electrical/hydraulic fluid control valve 2457 and an electric float switch 2272 controlling it. When using a boost pump on the fluid exchanger such as the embodiment of fluid changer 2525 which pressurizes the fresh fluid being delivered, If one is changing the fluid of a power steering system which uses a cap adapter that is held in place primarily by the low pressure provided by the power steering pump (see FIGS. 11-12), it is necessary to use a cap adapter which has an adjustable outside collar which extends downward and around the filler neck (such as filler neck 1002 of FIGS. 11-12) which can be hand tightened to be held securely in place even with the use of fresh fluid which has been positively pressurized. A mechanical/hydraulic fluid control valve and a mechanical float valve (as used in FIG. 3-5 or FIG. 16-17, or FIG. 20) can be substituted for fluid control valve 2457 and electric float switch 2272 if an additional magnetically operated micro-switch 462 and magnet are used with a relay in coordination with a flow switch 2251 on the a used fluid conduit to activate pump 2520 when the fresh fluid supply is adequate and the power steering pump is operative. One advantage of the alternate embodiment of FIG. 25, Fluid exchanger 2525 is that is can be constructed as a larger floor model which can be positioned below the power steering reservoir being serviced and can be constructed to be positioned at a substantial distance from the vehicle. It can also be constructed to be mounted on or within a service truck which can travel to the site location of the vehicle or machinery needing their power steering systems serviced. Additional advantages and modifications will readily occur to those of average skill in the art. The invention in its broader aspects is, therefore, not limited to the specific details, representative apparatus and illustrative examples shown and described. Accordingly, departures from such details may be made without departing from the spirit of scope of the applicant's general inventive concept. Parts List FIG. 1 100 reservoir 101 fluid 102 filler neck 103 cap 104 dipstick 105 pump 106 reservoir outlet conduit 107 inlet port 109 outlet port 110 pressure conduit 111 inlet port 112 steering gear assembly 113 outlet port 114 fluid return conduit 115 hose end 116 reservoir return port 117 hose clamp 118 pulley 119 belt 120 ferrule 192 combination pump reservoir assembly FIG. 2 117 hose clamp 120 ferrule 200 reservoir 201 fluid 202 filler neck 203 cap 205 pump 206 reservoir outlet port 207 pump inlet port 208 pump supply hose 209 pump outlet port 210 pressure conduit 211 inlet port 212 rack and pinion steering mechanism 213 outlet port 214 fluid return conduit 215 hose end 216 reservoir return port 218 pulley 219 belt FIG. 3 325 power steering fluid exchanger 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 330 top cover piece 331 vent 332 filler neck 333 cap 334 strainer 335 retainer cap 336 post 337 retainer cap 338 post 339 handle 340 skirt base 341 set of four footpads 342 ball valve 343 valve operating lever 344 45 degree connector 345 ball valve 346 valve operating lever 347 45 degree connector 349 bottom common wall 350 check valve 351 street tee 352 hose barb 353 90 degree hose barb 354 used fluid exchange hose 355 small female quick connect 356 used fluid hose 366 fresh fluid exchange hose 367 large female quick connect 457 fluid control valve 458 hose barb 462 magnetically operated micro-switch 463 90 degree hose barb 472 float FIG. 4 457 fluid control valve 458 hose barb 459 valve body 460 threaded hex plug 461 valve slide 462 magnetically operated micro-switch 463 90 degree hose barb 464 inlet port/fresh fluid channel 465 seal 468 threaded top end 469 magnet 470 float shaft 471 threaded end 472 float 473 retainer nut 474 alignment groove 475 alignment pin 476 collar 477 O'ring gland 478 threaded orifice 479 used fluid inlet port 480 fresh fluid delivery port 481 O'ring 482 female thread 483 valve bore 484 orifice 499 side port FIG. 5 457 fluid control valve 458 hose barb 459 valve body 460 threaded hex plug 461 valve slide 462 magnetically operated micro-switch 463 90 degree hose barb 464 inlet port/fresh fluid channel 465 seal 468 threaded top end 469 magnet 470 float shaft 471 threaded end 472 float 473 retainer nut 474 alignment groove 475 alignment pin 476 collar 477 O'ring gland 478 threaded orifice 479 used fluid inlet port 480 fresh fluid delivery port 481 O'ring 482 female thread 483 valve bore 484 orifice 499 side port FIG. 6 457 fluid control valve 458 hose barb 459 valve body 460 threaded hex plug 461 valve slide 462 magnetically operated micro-switch 463 90 degree hose barb 464 inlet port/fresh fluid channel 465 seal 468 threaded top end 469 magnet 470 float shaft 471 threaded end 472 float 473 retainer nut 474 alignment groove 475 alignment pin 476 valve slide rim 478 threaded orifice 479 used fluid inlet port 480 fresh fluid delivery port 481 O'ring 482 female thread 483 valve bore 484 orifice 499 side port 585 O'ring 586 threaded orifice FIG. 7 100 fluid reservoir 101 fluid 102 filler neck 105 pump 109 pump outlet port 110 pressure conduit 114 fluid return conduit 115 hose end of fluid return conduit 116 reservoir return port 117 hose clamp 118 pulley 119 belt 120 ferrule 192 combination pump reservoir assembly 323 cap 325 power steering fluid exchanger 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 331 vent 332 filler neck 333 cap 334 strainer 339 handle 340 skirt base 341 set of four footpads 342 ball valve 343 valve operating lever 345 ball valve 346 valve operating lever 354 used fluid exchange hose 355 small female quick connect 366 fresh fluid exchange hose 367 large female quick connect 472 float 786 port plug 787 ⅜″ male tube adapter 788 small male quick connect 789 cap adapter 790 large male quick connect FIG. 8 117 hose clamp 786 port plug 787 ⅜″ male tube adapter 788 small male quick connect 789 reservoir cap adapter 790 large male quick connect FIG. 9 117 hose clamp 200 fluid reservoir 206 reservoir outlet port 208 pump supply hose 215 hose end of fluid return conduit 216 reservoir return port 325 power steering fluid exchanger 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 331 vent 332 filler neck 333 cap 334 strainer 339 handle 340 skirt base 341 set of four footpads 342 ball valve 343 valve operating lever 345 ball valve 346 valve operating lever 354 used fluid exchange hose 355 small female quick connect 366 fresh fluid exchange hose 367 large female quick connect 472 float 787 ⅜″ male tube adapter 788 small male quick connect 790 large male quick connect 991 ⅝″ male tube adapter FIG. 10 117 hose clamp 787 ⅜″ male tube adapter 788 small male quick connect 790 large male quick connect 991 ⅝″ male tube adapter FIG. 11 117 hose clamp 1000 fluid reservoir 1002 filler neck 1003 cap 1006 reservoir outlet port 1008 pump supply conduit 1015 hose end of fluid return conduit 1016 return port of reservoir FIG. 12 117 hose clamp 325 power steering fluid exchanger 786 port plug 787 ⅜″ male tube adapter 788 small male quick connect 790 large male quick connect 1000 fluid reservoir 1002 filler neck 1006 reservoir outlet port 1008 pump supply conduit 1015 hose end 1016 reservoir return port 1185 cap adapter 1187 O'ring 1188 O'ring FIG. 13 117 hose clamp 1200 fluid reservoir 1202 filler neck 1203 cap 1205 pump 1209 pump outlet port 1210 pressure conduit 1215 hose end of fluid return conduit 1216 reservoir return port 1292 combination pump reservoir assembly 1293 O'ring 1294 cap retainer ring FIG. 14 117 hose clamp 786 port plug 787 ⅜″ male tube adapter 788 small male quick connect 790 large male quick connect 1200 fluid reservoir 1202 filler neck 1203 cap 1209 pump outlet port 1210 pressure conduit 1215 hose end of fluid return conduit 1216 reservoir return port 1292 combination pump reservoir assembly 1294 cap retainer ring 1395 reservoir cap adapter 1396 O'ring 1397 O'ring FIG. 15 117 hose clamp 787 ⅜″ male tube adapter 788 small male quick connect 790 large male quick connect 1200 fluid reservoir 1202 filler neck 1205 pump 1209 pump outlet port 1210 high pressure conduit 1215 hose end of fluid return conduit 1216 reservoir return port 1491 ⅜ hose 1292 combination pump reservoir assembly 1294 cap retainer ring 1495 suction tight cap 1496 O'ring 1497 O'ring 1498 ⅜ female hose adapter FIG. 16 117 hose clamp 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 349 bottom common wall 350 check valve 354 used fluid exchange hose 366 fresh fluid exchange hose 460 threaded hex plug 462 magnetically operated micro switch 469 magnet 473 retainer nut 475 middle threaded alignment pin 481 O'ring 1500 fresh fluid delivery port 1501 threaded orifice 1502 fluid power port 1503 fluid vent 1504 lower threaded end 1521 float ball 1522 wire float cage 1523 fresh fluid supply port 1524 fresh fluid supply conduit 1525 power steering fluid exchanger 1548 used fluid inlet port 1554 used fluid conduit assembly 1557 fluid control valve 1559 valve body 1561 valve slide 1565 seal 1566 fresh fluid exchange conduit 1568 threaded top end 1570 float shaft 1571 upper threaded end 1572 float 1574 alignment groove 1576 rim 1577 O'ring gland 1578 threaded orifice 1579 used fluid outlet port 1580 fresh fluid inlet port 1582 female thread 1583 valve bore 1584 orifice 1586 threaded orifice 1599 fluid channel FIG. 17 117 hose clamp 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 349 bottom common wall 350 check valve 354 used fluid exchange hose 366 fresh fluid exchange hose 460 threaded hex plug 462 magnetically operated micro switch 469 magnet 473 retainer nut 475 middle threaded alignment pin 481 O'ring 1500 fresh fluid delivery port 1501 threaded orifice 1502 fluid power inlet port 1503 fluid vent 1504 lower threaded end 1521 float ball 1522 wire float cage 1523 fresh fluid supply port 1524 fresh fluid supply conduit 1525 power steering fluid exchanger 1548 used fluid inlet port 1554 used fluid conduit assembly 1557 fluid control valve 1559 valve body 1561 valve slide 1565 seal 1566 fresh fluid exchange conduit 1568 threaded top end 1570 float shaft 1571 upper threaded end 1572 float 1574 alignment groove 1576 rim 1577 O'ring gland 1578 threaded orifice 1579 used fluid outlet port 1580 fresh fluid inlet port 1582 female thread 1583 valve bore 1584 orifice 1599 fluid channel FIG. 8 117 hose clamp 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 349 bottom common wall 350 check valve 354 used fluid exchange hose 366 fresh fluid exchange hose 460 threaded hex plug 462 magnetically operated micro switch 469 magnet 473 retainer nut 475 middle threaded alignment pin 481 O'ring 1500 fresh fluid delivery port 1501 threaded orifice 1502 fluid power inlet port 1503 fluid vent 1504 lower threaded end 1521 float ball 1522 wire float cage 1523 fresh fluid supply port 1524 fresh fluid supply conduit 1525 power steering fluid exchanger 1548 used fluid inlet port 1554 used fluid conduit assembly 1557 fluid control valve 1559 valve body 1561 valve slide 1565 seal 1566 fresh fluid exchange conduit 1568 threaded top end 1570 float shaft 1571 upper threaded end 1572 float 1574 alignment groove 1576 rim 1577 O'ring gland 1578 threaded orifice 1579 used fluid outlet port 1580 fresh fluid inlet port 1582 female thread 1583 valve bore 1584 orifice 1586 threaded orifice 1599 fluid channel FIG. 19 117 hose clamp 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 349 bottom common wall 354 used fluid exchange hose 361 fresh fluid exchange hose 460 threaded hex plug 462 magnetically operated micro-switch 469 magnet 473 retainer nut 475 alignment pin 481 O'ring 1504 lower threaded end 1521 float ball 1522 wire cage 1523 fresh fluid supply port 1565 seal 1570 float shaft 1571 upper threaded end 1572 float 1576 rim 1900 fresh fluid outlet port 1901 threaded orifice 1902 fluid power port 1903 fluid vent 1906 power port 1923 fresh fluid supply port 1924 fresh fluid supply conduit 1925 power steering fluid exchanger 1948 used fluid inlet port 1950 used fluid outlet port 1951 used fluid discharge port 1954 used fluid conduit 1955 used fluid conduit assembly 1956 fresh fluid conduit 1957 fluid control valve 1959 valve body 1961 valve slide 1968 threaded top end 1969 top small bore 1974 alignment groove 1977 O'ring gland 1978 threaded orifice 1980 fresh fluid inlet port 1982 female thread 1983 valve bore 1984 orifice 1986 threaded orifice 1998 side fluid channel 1999 cross fluid channel FIG. 20 117 hose clamp 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 349 bottom common wall 354 used fluid exchange hose 361 fresh fluid exchange hose 460 threaded hex plug 462 magnetically operated micro-switch 469 magnet 473 retainer nut 475 alignment pin 481 O'ring 1504 lower threaded end 1521 float ball 1522 wire cage 1523 fresh fluid supply port 1565 seal 1570 float shaft 1571 upper threaded end 1572 float 1576 rim 1900 fresh fluid outlet port 1901 threaded orifice 1902 fluid power port 1903 fluid vent 1906 power port 1923 fresh fluid supply port 1924 fresh fluid supply conduit 1925 power steering fluid exchanger 1948 used fluid inlet port 1950 used fluid outlet port 1954 used fluid conduit 1955 used fluid conduit assembly 1956 fresh fluid conduit 1957 fluid control valve 1959 valve body 1961 valve slide 1968 threaded top end 1969 top small bore 1974 alignment groove 1977 O'ring gland 1978 threaded orifice 1980 fresh fluid inlet port 1982 female thread 1983 valve bore 1984 orifice 1986 threaded orifice 1998 side fluid channel 1999 cross fluid channel FIG. 21 117 hose clamp 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 349 bottom common wall 350 check valve 354 used fluid exchange hose 361 fresh fluid exchange hose 460 threaded hex plug 473 retainer nut 475 alignment pin 481 O'ring 1504 lower threaded end 1521 float ball 1522 wire float cage 1523 fresh fluid supply port 1565 seal 1570 float shaft 1571 upper threaded end 1572 float 1576 rim 2101 threaded orifice 2103 fluid vent 2124 fresh fluid supply conduit 2125 power steering fluid exchanger 2148 used fluid inlet port 2154 used fluid conduit 2157 fluid control valve 2159 valve body 2161 valve slide 2168 threaded top end 2169 top small bore 2177 O'ring gland 2180 fresh fluid inlet port 2182 female thread 2183 valve bore 2199 fluid channel FIG. 22 177 hose clamp 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 349 bottom common wall 350 check valve 354 used fluid exchange hose 361 fresh fluid exchange hose 1521 float ball 1522 wire cage 1523 fresh fluid supply port 2210 switched power lead 2211 pair of upper micro-switch leads 2212 pair of lower micro-switch leads 2225 power steering fluid exchanger 2251 flow switch 2254 used fluid conduit assembly 2255 buzzer 2256 fresh fluid conduit assembly 2257 2 position-2 way solenoid valve 2258 battery pack 2259 battery pack socket 2260 used fluid conduit 2261 inlet port 2262 outlet port 2269 pair of magnets 2270 relay base 2271 float 2272 float switch assembly 2273 float shaft 2274 LED 2275 relay assembly 2277 magnetic winding FIG. 23 117 hose clamp 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 349 bottom common wall 350 check valve 354 used fluid exchange hose 361 fresh fluid exchange hose 2324 fresh fluid supply conduit 2353 fresh fluid supply port 2354 used fluid conduit assembly 2356 fresh fluid conduit 2357 2 position three-way solenoid valve 2361 inactivated inlet port 2362 common outlet port 2263 activated inlet port 2269 pair of magnets 2270 relay base 2275 relay assembly 2277 magnetic windings 2325 power steering fluid exchanger 2371 float 2372 float switch assembly 2373 float shaft FIG. 24 117 hose clamp 326 used fluid receiver 327 used fluid 328 fresh fluid reservoir 329 fresh fluid 349 bottom common wall 354 used fluid exchange hose 361 fresh fluid exchange hose 2251 flow switch 2255 buzzer 2269 pair of magnets 2270 relay base 2271 float 2272 float switch assembly 2273 float shaft 2274 LED 2275 relay 2277 magnetic windings 2356 fresh fluid conduit 2410 switched power terminal 2411 pair of upper micro-switch leads 2412 pair of lower micro-switch leads 2425 power steering fluid exchanger 2450 used fluid inlet port 2453 reservoir outlet port 2454 used fluid conduit 2455 used fluid conduit 2457 2 position 4 way solenoid valve 2458 power supply 2479 used fluid conduit 2480 fresh fluid supply conduit 2481 used fluid outlet port 2482 fresh fluid inlet port 2483 used fluid inlet port 2484 fresh fluid outlet port 2485 current 2486 neutral 2490 default inactivated mode 2491 activated mode FIG. 26 1905 hanger bracket 1906 bracket base 1907 hook FIG. 27 1909 adjustable hood support rod 1910 base rod section 1911 releasable latch 1913 top rod section 1914 bottom rod pad 1915 top rod pad 1916 nipple | <SOH> BACKGROUND OF THE INVENTION <EOH>With the current popularity of quick lubrication type services and the current emphasis on effective vehicle maintenance by the public, there has been an increasing market for the periodic changing the fluid in vehicular power steering systems as a regular maintenance procedure. A number of power steering fluid exchangers are currently being manufactured, but the need remains for an automatic power steering fluid exchanger which has all of the following desirable characteristics: the exchanger does not require connection to a vehicle's electrical system or other source of electrical power or to a compressed air supply; the fluid exchanger has the power needed for the exchange provided by either the positive and negative pressures of the power steering pump and/or provided by the exchanger's own battery power; the fluid exchanger is compact, lightweight, portable, easy to position, simple to connect, and easy to operate; the fluid exchanger is able to automatically exchange its fresh fluid for the power steering system's used fluid in approximately equivalent volumes and rates of flow; the fluid exchanger automatically and reliably establishes a closed fluid circulation circuit between the inlet port and the outlet port of the power steering pump at the completion of the fluid exchange and maintains it until the service equipment operator turns off the vehicle's engine. Fluid exchange units for power steering currently available to vehicular service centers typically consist of two categories of units, the small and portable inexpensive units and the larger much more expensive units. The units in the first category are at the lower end of the expense continuum and are small, compact toolbox sized units which can be placed on the fender or engine of the vehicle for service use. These small, compact units typically consist of two electric pumps connected to the vehicle's battery and which are simultaneously operated to extract used fluid from the reservoir of the power steering system while also injecting fresh fluid into that reservoir to replace it. This simultaneous injection of fresh fluid and extraction of used fluid is instituted through the fill cap/dipstick opening of the power steering fluid reservoir after the reservoir cap is removed and with the engine idling to make the power steering unit operative. This first category of units have been disclosed in the Knorr in U.S. Pat. No. 5,415,247 and by Dixon in U.S. Pat. No. 6,035,902. Both feature two electrically operated pumps, each of which is connected to an associated fluid delivery hose, with one hose-pump combination conducting fresh fluid into the power steering reservoir and the other hose-pump combination extracting used fluid out of the power steering reservoir. During the fluid exchange both conduits are placed inside the reservoir at different levels and both pumps are operated simultaneously. This type of unit is compact and easy to position but because it is manually operated it must be closely monitored to prevent air infusion into the power steering system upon depletion of the fresh fluid supply. A significant drawback of this type of unit is the need to connect the unit to the vehicle's electrical system. Another drawback is its concurrent mixing of fresh fluid with contaminated used fluid in the power steering reservoir right before it is delivered to the low pressure port of the power steering pump. This tends to result in an incomplete fluid exchange typically characterized by a correspondingly lower proportion of fresh fluid exchanged for the used fluid in the circuit, compared to the second category of power steering fluid exchange units which are much more expensive and, if used properly, typically exchange a higher percentage of the used fluid for fresh. Therefore, the units of the first category, best described as “mixing type” units are only minimally effective and of limited suitability for periodic fluid exchange maintenance of power steering systems when compared to larger, more expensive units. The units of the second category, larger and more expensive, are therefore more desirable than the small mixing type units due to their higher effectiveness in exchanging fluid. However, their higher price is a drawback which can make them less available to vehicular service centers with limited funds for service equipment acquisitions. An additional drawback is that units of this second category tend to be significantly larger, heavier, less portable and therefore less convenient to operate than the smaller, compact and much less expensive units described above to be in the first category. This second category of units includes a power steering fluid exchanger disclosed by Dixon et al in U.S. Pat. Nos. 5,806,629 and 5,583,068. This unit is connected to communicate fluidly with the power steering system's low side positive pressure discharge hose to receive used fluid there from, and is connected to communicate with the power steering pump's negative pressure or suction hose to deliver fresh fluid thereto. In order for the fluid exchange to be instituted this device must be connected to the vehicle's battery so that the unit can be activated by the operator closing an electrical switch to institute the fluid exchange which is a drawback. This unit, as do all the units in this second category of units, requires its own onboard pump to deliver fresh fluid into the power steering system. In this example, the Dixon et al device uses the used fluid flow from the pump of the power steering system to power the onboard fresh fluid pump. The need for a power steering fluid exchanger to have its own onboard pump adds significantly to the cost of the unit. In the power steering fluid changer depicted in U.S. Pat. Nos. 5,806,629 and 5,583,068, the most important function is to provide a pumping means which controls both the used fluid flow and the fresh fluid flow to be approximately equivalent in rate and volume. In these patents, the power steering fluid changer uses a positive displacement fresh fluid pump which is powered by the discharge pressure of the pump of the power steering system. Harnessing the used fluid flow from a vehicular hydraulic circuit's own pump to power a fluid exchanger's fresh fluid positive displacement pump was a novel concept first disclosed by Viken in U.S. Pat. No. 5,318,080 which related to exchanging the fluid of an automatic transmission. Power steering system fluid exchange units based on this principal are typically expensive not only because of the size of the case required, but their complexity makes the cost of manufacturing an exchanger with a positive displacement fresh fluid pump which harnesses the power of the power steering pump quite substantial. When the unit's fresh fluid supply in the power steering fluid changer depicted in U.S. Pat. Nos. 5,806,629 and 5,583,068, becomes depleted, an electrical float switch opens which then in turn deactivates the electrical solenoid of a three-way hydraulic valve to stop the fluid exchange and to shift the unit back to its original flush mode of operation which is a default closed loop circulation allowing the pump of the power steering system to circulate fluid from its discharge port back to its inlet port. Also disclosed in the Dixon et al U.S. Pat. No. 5,806,629 is a suggestion for an alternative embodiment which requires no electrical power for its operation by replacing the solenoid operated valve with a manually actuated valve that requires close operator attention to manually revert the machine from exchange mode to flush mode when delivery of the new ATF into the transmission is completed. It is also suggested that the manually actuated three-way valve can be spring loaded and manually latched into place by the service technician to remain in its exchange-mode position until a dropping float could then release a triggering device to release the spring loaded three way valve to return under spring power to its default flush mode of operation. Dixon et neither suggested or disclosed the use a three-way valve that is directly and responsively controlled by an attached float as it freely rises or falls in the fresh fluid reservoir in response to the fluid level as is disclosed in the preferred embodiment of this instant invention. The devices of this second category, the larger more expensive units that actually exchange fluid without just mixing it in the power steering reservoir, are expensive to manufacture because they require costly electric solenoid operated valves which need electrical power. The need remains for a small, compact, lightweight, easily portable power steering fluid exchanger which does not require electrical power, does not require one or more of its own fresh fluid delivery pump(s) to operate, and does not require a costly automatic fluid flow control mechanism to approximately match the fresh and used fluid flow rates and volumes. Both the first and second categories of devices, the less expensive and the more expensive, typically require connection to the vehicle's battery or electrical system in order to operate. It is desirable for a service center to acquire a power steering fluid exchanger which does not require connection to the vehicle's electrical system for a number of reasons. First, having to make connection to vehicle's battery requires the use of connection wires which can make contact with moving parts in the engine compartment if wrongly positioned or moved during the fluid exchange. Second, many currently manufactured vehicles have sophisticated onboard diagnostic computer systems (OBD systems) which can sense voltage changes, voltage spikes, and anomalies in the vehicle's electric system and which will then record a fault code. If the exchanger's wires are not securely connected to the battery or electrical system of the vehicle a spark may be generated or if a short develops in the exchanger's wiring, either of these occurrences can trigger a warning code in the vehicle's computer which may result in the vehicle's computer directing the vehicle to operate in a special default mode. There have been articles published in the automotive trade literature predicting that vehicles manufactured in the future will be increasingly dependent on even more sophisticated onboard diagnostic computer systems (OBD systems). It is expected that these advanced OBD systems may be increasingly sensitive to unnecessary, non-operational current fluctuations, which may cause false error codes or cause the vehicle to assume a default mode of operation which lowers the gas mileage of the vehicle until the computer system is reset, which typically requires the vehicle to be driven for a period of time. For example, some Chrysler OBD systems are so sensitive that if a single spark plug or spark plug wire fails, the vehicle will be placed in a default operational mode with the automatic transmission operable in second gear only. Third, there have articles published in the automotive trade literature which predict that in the not too distant future automotive manufacturers will likely utilize new, higher voltage systems accompanied by newly designed high output combination alternator/starters and electrically powered air conditioners, brakes and/or suspensions. If these expected voltage increases are implemented service equipment which has been manufactured for 12 volts direct current (DC) will become obsolete and unusable unless it is modified to accept these higher voltages. If it has to be modified or replaced this will be an added and undesirable expense. Another type of power steering fluid changer which has been available in the past has been the unit depicted by Baylor et al in U.S. Pat. No. 5,015,301. This device is operated with the vehicle's engine off and the power steering pump inoperative. This device consists of a tank with a bladder type “pusher” which holds fresh fluid on the top side and receives compressed air as a powering medium on the lower side. The need for access to shop air can limit the service area used to provide the fluid exchange. Once this device of Baylor et al is connected to the power steering system, compressed air is then provided to the lower side of the diaphragm “pusher” to pressurize the fresh fluid to flow into and through the low pressure inlet hose (or conduit) of the power steering pump to then flow through the rest of the power steering system and then finally out of the low pressure reservoir return hose (or conduit) to the unit's open used fluid receiver. The Baylor et al patent shows only a remotely arranged reservoir style power steering system in its figures and apparently neglects to illustrate, describe and explain how the unit would be specifically connected to service the more traditional type of power steering system which has a combination reservoir/pump assembly. The Baylor et al patent teaches that this unit is operated only with the engine of the vehicle off and the pump of the power steering system not operating. The unit is normally operated in two separate procedures, the first time to infuse a fresh flushing mixture into the power steering system. The unit is then disconnected temporarily while the vehicle's engine is run for awhile to therefore circulate the fluid flushing mixture through the power steering system to dissolve varnish buildup and contaminants. The engine is then turned off and the unit is reconnected and operated a second time to flush the power steering system, this time only using fresh power steering fluid with perhaps an additive package. This particular unit is somewhat bulky and cumbersome to use, and due to the multiple steps involved, takes an unnecessarily long time to operate. In addition it seems likely that the use of such a flushing procedure without the power steering pump operative would not be as effective in removing all the used fluid as would a fluid exchange procedure accomplished with the power steering pump operative. These drawbacks prevent it from being a preferred option for those service centers who want a unit that is compact, self contained with no need for compressed shop air or connection to a source of electrical power, simple to operate and capable of exchanging a high proportion of used fluid for fresh fluid in a relatively short period of time while the power steering pump is operative. The Graham U.S. Pat. No. 5,971,021 discloses a method for filling a new and empty power steering system or other hydraulic circuit with fresh fluid by using a specialized valve. Graham also suggests that this method can be used to exchange used fluid for fresh fluid as a maintenance procedure. It is not known if this product is commercially available at this time. This patent appears to teach the connection of a specially designed valve device midstream into the high pressure conduit of a fluid system, such as a power steering system or cooling system for the purpose of filling that fluid system for the first time. This methods teaches pressurizing a fluid and then injecting that pressurized fluid through this specialized valve which has been installed into a two sided conduit. A substantially unidirectional flow pattern through a selected side of the intercepted conduit is established by injecting most of that pressurized fluid through the valve into that selected side of the intercepted conduit while allowing a small portion of that pressurized fresh fluid to be injected into the other side of that conduit by leaking around the slide of the specialized valve. As the pressurized fresh fluid is injected into the power steering system air contained in the system is also simultaneously driven out. This valve and its use are depicted as being particularly applicable to power steering fluid systems and one figure illustrates this valve as being interconnected to such a system between the power steering pump and “gearbox” midstream in the pump's high pressure outlet conduit, with the valve arranged to discharge its pressurized fluid in a substantially unidirectional flow in the direction of the conduit which leads to the gearbox. After this valve is properly connected to a new but empty power steering system, a pre-pressurized source of fresh fluid is then connected to this valve which in turn causes the valve to operate to inject pressurized fresh power steering fluid in a substantially unidirectional flow to fill the system and to displace air out of the system, with the capability of simultaneously allowing some fluid to also be infused upstream, thus displacing the air from two directions. This pressurized fresh fluid remains pressurized as it flows into and through the steering mechanism. It is also taught that this valve may be connected to a used power steering system which is filled with used fluid for the purpose of exchanging its used fluid for fresh fluid as a maintenance procedure. Installing this valve as depicted for routine power steering fluid exchanges would be somewhat difficult task in and of itself due to the tendency for the power steering pump's high pressure conduit (or hose) to have connections which are often be corroded and typically somewhat difficult to reach and disconnect. It appears that no mention is made of whether the vehicle's engine is operative while the procedure is enacted. However, the suggested positioning at which the valve is connected as apparently disclosed in Graham's patent is downstream from the pump's outlet port, and therefore it is assumed that the power steering system must be inoperative while a new fluid fill or a fluid exchange is instituted, since operating the pump with the valve downstream would obstruct the output flow of the pump and perhaps could damage the power steering pump if it's relief valve was malfunctioning or its setting was too high. Unless the valve was purchased by customer and permanently installed, at each fluid exchange service, the valve would have to be installed and used after disconnecting the power steering systems' high pressure hose (conduit). After the fluid exchange was completed the high pressure line would have to be disconnected from the valve and reconnected in its proper configuration to the power steering pump. It appears then that use of this valve and method would be too slow and unduly cumbersome to be practical for use at most vehicle service centers as a regular power steering maintenance procedure. The Sangret U.S. Pat. No. 5,664,416 discloses a new and improved method for filling a new power steering assembly with fluid for the first time on an auto assembly line. This patent discloses a method for pumping fluid from a bulk holding tank into the power steering system's reservoir to circulate in the power steering system with the engine operative under power of the power steering pump, after which that fluid is then discharged and returned to the bulk holding tank for redundant circulation back into and through the power steering system. When a new power steering system is filled for the first time air typically becomes entrained in the power steering fluid and this method offers a solution for remove that entrained air. The patent discloses that air entrained in a power steering system may cause unwanted noise and/or vibration which may be annoying to the driver who first operates the vehicle after the filling of the power steering system. This method teaches that redundant circulation of fluid in and out of the bulk holding tank is instituted until the power steering system is completely filled with fluid and the entrained air has been removed. This method teaches the placing of a special connector assembly in the filler opening of a certain very select configuration of remotely arranged power steering reservoir, a reservoir which has its low pressure fluid return port directly placed below and on center of the filler neck of the reservoir. This connector assembly takes the position of the reservoir cap type and has both a fresh fluid delivery conduit and a used fluid receiving or discharge conduit passing through it into the filler opening of this select type of remote power steering system reservoir. This adapter is pushed into the filler neck of the reservoir which inserts its used fluid receiving conduit matingly down and into the used fluid return port of the reservoir which is directly below and on center to the filler neck of the reservoir. This used fluid receiving conduit then receives fluid which is discharged from the power steering pump being returned to the reservoir. The fresh fluid delivery conduit of the connector assembly is shorter than the discharge conduit and does not connect with the supply conduit port of the reservoir which is located off center of the reservoir, but it discharges fresh fluid into the reservoir after being pumped out of a bulk holding tank which is sealed and provided with a vacuum pump for extracting entrained air out of the fluid. The holding tank is shown with its own fresh fluid delivery pump for delivery fresh fluid through the special adapter into the power steering reservoir. The patent does not disclose using the power steering pump's low pressure inlet port side or its positive pressure outlet side for powering the pumping of fluid into and through the power steering system redundantly, even though the engine is running to render the power steering pump operative. The fluid discharged by the pump is then delivered through the connector assembly and into the bulk holding tank which is actually a large additional fluid reservoir which both provides supply fluid for delivery into the power steering system and receives the fluid discharged from the power steering system. The method does not disclose or teach the exchange of used fluid for fresh fluid and is apparently limited to charging a power steering system for the first time while removing the air that inevitably becomes entrained. The method of Sangret discloses an arrangement of one electrically operated valve and two electrically operated pumps which are simultaneously activated by an electronic control unit which energizes an inductive coil when the vehicle's engine is started. The valve is a flow control valve which stops fluid flow out of the bulk holding tank when the engine is turned off which inactivates the valve, and allows fluid flow out of the bulk holding tank and into the power steering reservoir when activated by the engine running. One pump is a vacuum pump which is connected to a port near the top of the bulk tank and provides enough low pressure to evacuate any air which has become entrained in the power steering fluid after it returns to the holding tank as the power steering system is filled for the first time. The other pump is a fluid delivery pump, referred to as a flow charge pump, which when activated by the electronic control unit will pump fluid from the bulk holding tank into the power steering reservoir where the low pressure provided by the power steering pump then delivers that fluid into the conduit supplying the power steering pump. The flow charge pump appears to be necessary for two reasons. First, the patent depicts the fluid supply port at the bottom of the bulk holding tank to be at a level below that of the connector assembly, and the negative pressure provided by the power steering pump is not likely to be great enough to pump the fluid from the bulk holding tank without assistance by an auxiliary pump. Second, the low pressure provided by the vacuum pump will likely conflict with the low pressure provided by the power steering pump which would inhibit the flow of the fresh fluid into the conduit supplying the power steering pump. The special connector assembly which is inserted into the filler neck of the power steering reservoir is shown to have a set of three O'rings for sealing but is not shown to have a positively engaging set of tab locks like many power steering caps. It can be assumed that the connector is held in place only by sidewall friction between the cap, its O'rings and the filler neck of the reservoir and any low pressure provided by the power steering pump through that pump's inlet port. One potential drawback to the use of this method of filling a new power steering system with fresh fluid for the first time is that the flow charge pump must have a delivery output pressure great enough to overcome the low pressure provided by the vacuum pump but not so great as to deliver fluid at a greater flow rate to the reservoir than the power steering pump will accept it. If this occurs pressure can build up inside the reservoir which can disrupt the sealing of the connector into the reservoir filler neck and perhaps can cause leakage of fluid and displacement of the connector up and out of position in the filler neck. The Brown U.S. Pat. No. 5,291,968 discloses an “Apparatus and Method for Changing Automatic Transmission Fluid in Motor Vehicles” and does not address changing fluid in power steering systems. It discloses the method of removing the pan of a transmission to access the intake port of the suction conduit of the transmission pump to then connect a pressurized fresh fluid supply to that intake port while idling the engine to operate the transmission and while providing a pan underneath the transmission to receive the fluid discharged from the transmission's pump. Because the fresh fluid reservoir of the apparatus is at floor level, and since the low pressure provided by the transmission's pump is inadequate to deliver the fresh fluid from floor level up and into to the port of that suction conduit and into the transmission, the unit requires its own on-board pump to deliver fresh fluid up to the port of the suction conduit of the transmission pump. In addition, this method apparently requires close monitoring by the operator since the engine must be turned off as soon as the fresh fluid supply of the fluid exchanger is depleted to prevent air from being pumped into the transmission. The Matta U.S. Pat. No. 4,342,328 depicts a two stage float valve which is connected to a suction tube. The purpose of this float valve is to close off a fuel tank from the suction tube when the fuel tank starts to run dry and fuel is being drawn from another tank. This float valve is configured to be resistant to closing prematurely from the effect of the suction provided by the suction tube. This is accomplished by providing an inner poppet which equalizes the negative pressure of the suction tube to both sides of the valve's primary seal thereby neutralizing the effects of the suction on the valve's primary seal. This allows the use of a smaller float than would otherwise be necessary and prevents the negative pressure provided from the suction tube from adversely affecting the operation of the valve. This patent disclosed the problem of establishing an air tight seal when a fluid supply is diminished and the importance of preventing low pressure or suction from prematurely closing the valve. The float valve disclosed in this patent by Matta is a fluid supply valve only and does not control any exchange of fluids. The Colvin, et al. U.S. Pat. No. 6,477,886 discloses a test apparatus for measuring the amount of air entrained in the fluid of a power steering system. The apparatus also includes a vacuum pump for drawing air out of the power steering pump. It disclosed that air and other gases entrained in the power steering fluid may result in excessive noise during the operation of the pump and may include whining and hissing, and that these noises may be similar to noises caused by improperly functioning components. It is disclosed that it is useful to be able to use a measurement device to indicate if entrained air is significant enough to be causing such noises or if not that the power steering system is damaged. This lends further credence to the importance of not allowing air to become entrained by a power steering fluid exchanger when exchanging the fluid of a power steering system since it may mask the sounds created by damaged components. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention is a light, very compact, portable, easy to position, easy to connect, and easy to operate, automatic power steering fluid exchanger with a fresh fluid reservoir, a used fluid receiver, and a fluid control valve which directs the operation of the fluid exchanger and is itself operated by a float in the fresh fluid reservoir. The float which operates the mechanical/hydraulic fluid control valve is a mechanical float, while the float controlling the electrical/hydraulic is an electric float switch. In the preferred embodiment negative pressure provided by the power steering pump is used to assist in the operation of the fluid control valve. In one alternative mechanical/hydraulic embodiment positive pressure provided by the power steering pump is used to assist in the operation of the fluid control valve. In another alternative mechanical/hydraulic embodiment both negative pressure and positive pressure provided by the power steering pump are used to assist in the operation of the fluid control valve. The used fluid receiver of the fluid exchanger is emptied of used fluid from the prior fluid exchange. The fluid exchanger's fresh fluid reservoir is filled with an adequate volume of fresh fluid which causes the float in the fresh fluid reservoir to rise to its upward position. The power steering system's fluid circuit is opened to divide and isolate the power steering pump's inlet port or low pressure side from its outlet port or pressure, discharge side. The fluid exchanger is connected to the power steering system using suitable adapters after either removing the power steering reservoir from the power steering system or converting it to be essentially vent free and filled with fluid. The exchanger's fresh fluid exchange hose is connected to arrange its fresh fluid reservoir to supply the power steering pump's inlet port, and the exchanger's used fluid exchange hose is connected to arrange its used fluid receiver to receive used fluid discharged from the power steering pump's outlet port. The vehicle's engine is started which renders the power steering pump operative which causes the fluid exchanger to automatically exchange its fresh fluid for the used fluid of the power steering system. The fresh fluid delivered from the fluid exchanger into the power steering system flows at approximately the same equivalent rate and volume of flow as the power steering system's used fluid is discharged into the exchanger's used fluid receiver. When the fresh fluid supply becomes depleted, the float in the fresh fluid reservoir moves to its downward position which establishes a closed fluid circulation circuit for the power steering pump. This closed fluid circulation circuit is characterized by the establishment of essentially vent free fluid communication between the pump's outlet and inlet ports with no communication between the exchanger's fresh fluid reservoir and the power steering pump's inlet port, and with no communication between the used fluid receiver and the pump's outlet port. If an electrical/hydraulic fluid control valve is used a float switch be alternatively positioned in the used fluid receiver to sense when it is full to inversely control the fluid control valve to establish a closed fluid circulation circuit. This may be done alone or in coordination with an electric float switch also used in the fresh fluid reservoir to sense when the fresh fluid supply is depleted. In the preferred embodiment and the other alternative embodiment herein, a single float is positioned in the fresh fluid reservoir since it was found in experimentation to be more practical than using a single float in the used fluid receiver, especially when the operator forgets to fill the fresh fluid reservoir with fresh fluid and connects the exchanger and then starts the vehicle's engine, which quickly infuses and entrains air in the fluid of the power steering system from an empty fresh fluid reservoir. One object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which provides a light weight, compact, easily portable unit which can be positioned in a convenient location. The fluid exchanger should have a small footprint and contains a compact fresh fluid supply reservoir which is large enough to provide a virtually total or nearly total exchange of the fresh fluid of the fluid exchanger for the used fluid of most or nearly most vehicular power steering systems seen in automotive service and lube centers. Another object of the invention is to provide an apparatus and method for exchanging the fluid of a power steering system which is relatively inexpensive to purchase while being comparable in function to other more expensive fluid exchangers which actually exchange the used fluid of the power steering system for the fresh fluid of the fluid exchanger rather than just mixing and diluting the used fluid with fresh fluid within in the power steering reservoir, as is used in some inexpensive and relatively ineffective power steering fluid exchangers on the market today. Since time is equivalent to cost in the vehicular maintenance industry, another object of the invention is to provide an apparatus and method which provides a rapid exchange of the used fluid of a power steering system with fresh fluid. Another object of the invention is to provide an apparatus for exchanging the fluid of a power steering system which is easy and quick to connect and operate, one which requires minimal training for new service technicians. The apparatus and method will provide for easy connection to both types of power steering systems layouts, the type of power steering system layout where the reservoir is combined with the pump and also the type of power steering system layout which has a fluid reservoir remotely positioned above and away from the power steering pump. Another object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which provides for isolated delivery of fresh and used fluid through two separate respective conduits, with one connected to deliver fresh fluid from the fluid exchanger's fresh fluid reservoir to the inlet side conduit of the power steering pump and the other to deliver used fluid delivered from the power steering pump to the fluid exchanger's used fluid receiver. Another object of the invention is to provide an apparatus and method which will exchange a significantly higher proportion of fresh fluid for used fluid than the first or inexpensive category of exchangers which are exemplified by the use of two pumps which mix fresh fluid and used fluid for partial dilution within the power steering reservoir through its filler neck. Another object of the invention is to provide an apparatus and method for exchanging the used fluid of a power steering system for fresh fluid while the vehicle's engine idles without requiring any connection to a power source which is not inside the fluid exchanger such as having to connect the exchanger to the vehicle's battery or electrical system, to a 115 volt or 220 volt AC current source or to the service center's compressed air supply. This can be accomplished by powering the fluid exchanger solely by the low pressure provided by the power steering pump in coordination with atmospheric pressure and positioning the fluid exchanger above the power steering pump at the same level or somewhat higher than the power steering reservoir. A power pack contained in the exchanger may be provided to power a float switch, a fluid control valve, and other indicators such as a warning tone and a bright red, blinking LED alert. Another object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which automatically starts exchanging fluid when the vehicle is started and allows the operator to take his time turning off the engine after the completion of the fluid exchange with no obstruction or interruption of flow into and out of the power steering pump. The fluid exchanger will automatically stop exchanging fluid when its fresh fluid reservoir becomes depleted while simultaneously allowing the power steering pump to freely circulate fluid from its outlet port back to its inlet port in a closed fluid circulation circuit. The fluid exchanger's operation will be automatically controlled by a fluid control valve which in turn is controlled by a float positioned in the fresh fluid reservoir, and this float will be directly and responsively controlled by the rising or falling of the fresh fluid level without the required use of any springs or manually spring loaded latches. Use of a float operated fluid control valve allows the fluid exchanger to automatically shift from exchanging fluid to circulating fluid in a closed fluid circulation circuit and back again when the fresh fluid reservoir is refilled for the next fluid exchange. Another object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which automatically delivers fresh fluid and used fluid at approximately the same rates of flow and in the same approximate volumes. If the rates of flow and the volumes of flow of the fresh and used fluid are not approximately equivalent, significant differences can result in differences in the volumes of fresh and used fluid delivered at any one time, creating a situation of too much fresh fluid or used fluid delivered in comparison to one another with the resulting fluid overflow or fluid starvation of the power steering system. Another object of the invention is to provide an apparatus and method for exchanging fluid in a vehicle's power steering system which does not infuse air into the power steering system during the exchange of used fluid for fresh or after the fluid exchange. Infusion of air is undesirable since it quickly becomes entrained and tends to expand the volume of the fluid, resulting in fluid starvation of the fluid circuit's pump, loss of effective lubrication and diminished capacity of the fluid to transmit power. This entrainment of air and resulting loss of fluid power capacity is typically accompanied by significant noise in the power steering system and significant reduction of ability to steer the vehicle. Unabated, such a condition can damage the power steering system. If is does not damage the power steering system, the loud noise can certainly alarm the vehicle's owner and the loss of full steering power can pose a safety issue if not quickly remedied. Therefore, if this condition occurs, the vehicle should not leave the service center until it is resolved. Resolving this condition adds additional complexity and time to the procedure since it may take a period of minutes for the entrained air to release from the fluid while the engine idles. When air releases from the fluid, the fluid volume lessens, thus often requiring additional or multiple topping off of fluid. This delays the completion of the fluid exchange procedure and can project an undesirable image to the customer who stays in or near his vehicle while having the power steering fluid is exchanged and who hears the resulting loud noises in their power steering system from the entrained air and witnesses the efforts of the service technician to remedy the problem. Experimentation by the inventors has shown that development of a purely mechanical/hydraulic float operated fluid control valve without electrical activation required meeting some unique challenges in order to develop a valve which will smoothly shift from a fluid exchanging mode of operation to a second mode of operation which allows the power steering system to circulate its fluid in a closed fluid circulation circuit through the fluid exchanger and the power steering system without allowing air to enter the fluid. When the fresh fluid supply has become depleted, an effective seal must be established between the fresh fluid reservoir and the fluid control valve or air will be pumped into the power steering system from the fresh fluid reservoir if the engine of the vehicle is allowed to continue running. It was also discovered that the tighter the sealing provided to valve slide where it enters the fresh fluid reservoir, the more effectively it sealed, but also the more difficult it was for the slide to move up and down in the valve body. Without the serendipitous discovery of the effective pressure assisted sealing methodology herein disclosed, effective sealing provided to the valve slide typically caused the valve slide to either move sluggishly or become stuck and to stay in its fluid exchange position even when the fresh fluid supply was depleted. Attempts to increase the size of the float to allow greater weight to be added to the float as a single solution to this problem were unsuccessful. An effective solution to the sealing problem was thus conceived during the process of experimentation. It was determined that the best solution was to provide and maintain an effective seal for the fluid control valve from the fresh fluid reservoir only upon depletion of the fresh fluid supply, and this could be accomplished by selectively harnessing and utilizing the low pressure provided by the power steering pump through the fluid exchanger's fresh fluid supply hose to establish and hold an effective seal. As long as this low pressure is used to provide and maintain a seal between the valve slide and the fresh fluid reservoir only when the fresh fluid supply became depleted, the valve slide is able to freely move to its lower position to establish a closed fluid circulation circuit for the power steering pump without allowing the infusion of air which quickly become entrained in the fluid. Any infusion of fresh fluid through or around the slide during the fluid exchange is acceptable since the slide is used as a fresh fluid port in the preferred embodiment. It was also discovered that the positive and negative pressures provided by the power steering pump could be harnessed and utilized to assist a mechanical/hydraulic float operated valve in shifting to its closed fluid circulation mode when the fresh fluid supply became depleted. It was also discovered that eliminating the fresh fluid supply port as a separate entity in the bottom of the fresh fluid reservoir and combining it internally with the control valve slide was helpful in preventing air infusion from an empty fresh fluid reservoir. Another critical issue which was resolved by the inventors in experimentation was the developing and implementation of a method to effectively seal off the used fluid receiver from the closed fluid circulation circuit when it was established and maintained by the fluid control valve. | 20040129 | 20060228 | 20050804 | 65183.0 | 0 | MAUST, TIMOTHY LEWIS | AUTOMATIC FLUID EXCHANGER | SMALL | 0 | ACCEPTED | 2,004 |
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10,769,161 | ACCEPTED | REFRIGERANT CYCLE WITH TANDEM ECONOMIZED AND CONVENTIONAL COMPRESSORS | A refrigerant cycle is provided with tandem compressors. Only some of the multiple compressors are provided with an economized cycle, and an optional unloader valve for selectively returning flow from an economizer injection port back to suction. The present invention thus provides the economized operation capabilities and benefits for a refrigerant cycle having tandem compressors, without the complexity of providing separate economizer arrangement for each of the compressors. | 1. A refrigerant cycle comprising: at least two compressors, said compressors having discharge ports communicating with a common discharge manifold; and suction ports communicating with a common suction manifold; a first heat exchanger downstream of said discharge manifold; a main flow line leaving said first heat exchanger and leading to at least one economizer heat exchanger, and at least one tap line off of said main flow line upstream of said at least one economizer heat exchange, refrigerant in said tap line and refrigerant in said main flow line both passing through said at least one economizer heat exchanger, said main refrigerant flow returning to said compressors; and refrigerant in said tap line passing to at least one of said compressors downstream of said economizer heat exchanger and not passing to at least one compressor. 2. A refrigerant cycle as set forth in claim 1, wherein an economizer shutoff valve controls flow of tapped refrigerant through said at least one economizer heat exchanger. 3. A refrigerant cycle as set forth in claim 2, wherein said shutoff valve is a solenoid valve. 4. A refrigerant cycle as set forth in claim 2, wherein said shutoff valve is part of an expansion device. 5. A refrigerant cycle as set forth in claim 1, wherein said economizer return line communicates with an intermediate compression point in said one compressor. 6. A refrigerant cycle as set forth in claim 5, wherein an unloader line communicates with said economizer return line, and has an unloader valve for selectively controlling flow through said unloader line back to a suction line returning refrigerant to said one compressor. 7. A refrigerant cycle as set forth in claim 1, wherein a control is provided with control options recognizing that said at least one compressor has economized operation as an option. 8. A refrigerant cycle as set forth in claim 1, wherein there are at least three of said compressors, with at least two not receiving refrigerant from said tap line. 9. A refrigerant cycle as set forth in claim 1, wherein there are at least three compressors, with at least two of said compressors receiving refrigerant from said tap line. 10. A refrigerant cycle as set forth in claim 9, wherein a single economizer heat exchanger delivers refrigerant to said at least two of said compressors. 11. A refrigerant cycle as set forth in claim 9, wherein at least two economizer heat exchangers deliver refrigerant separately to said at least two of said compressors. 12. A refrigerant cycle comprising: at least two compressors, said compressors having discharge ports communicating with a common discharge manifold; and suctions ports communicating with a common suction manifold; a first heat exchanger downstream of said discharge manifold; a main flow line leaving said first heat exchanger and leading to at least one economizer heat exchanger, and at least one tap line off of said main flow line upstream of at least one of said economizer heat exchange, refrigerant in said tap line and refrigerant in said main flow line both passing through said at least one economizer heat exchanger, said main refrigerant flow returning to said compressors; refrigerant in said tap line passing to at least one of said compressors downstream of said economizer heat exchanger and to an intermediate compression point, and not passing to at least one of said compressors, an economizer return valve controlling flow of said tapped refrigerant; and a control is provided with control options recognizing that said at least one compressor has economized operation as an option. 13. A refrigerant cycle as set forth in claim 12, wherein an unloader line communicates with said economizer return line, and has an unloader valve for selectively controlling flow through said unloader line back to a suction line returning refrigerant to said at least one compressor. 14. A refrigerant cycle as set forth in claim 12, wherein there are at least three of said compressors, with at least two not receiving refrigerant from said tap line. 15. A refrigerant cycle as set forth in claim 12, wherein there are at least three compressors, with at least two of said compressors receiving refrigerant from said tap line. 16. A refrigerant cycle as set forth in claim 15, wherein a single economizer heat exchanger delivers refrigerant to said at least two of said compressors. 17. A refrigerant cycle as set forth in claim 15, wherein at least two economizer heat exchangers deliver refrigerant separately to said at least two of said compressors. | BACKGROUND OF THE INVENTION This invention relates to a refrigerant cycle having tandem compressors, wherein only some of the compressors are provided with economizer ports and can be utilized within an economizer cycle. Tandem compressor refrigerant cycles are known, and have two or more compressors compressing refrigerant and delivering it to a common discharge manifold. Similarly, these compressors are drawing refrigerant from a common suction manifold. In some arrangements, oil equalization lines connecting oil sumps of the tandem compressors for oil management and suction pressure equalization lines connecting shells of the tandem compressors are employed. Tandem compressors provide flexibility to a refrigerant cycle designer, such as allowing additional levels of capacity control by turning off some of the compressors. Moreover, in some applications that would require a very large single compressor, tandem compressors provide design options, availability, and potential cost savings. In refrigerant cycles having a single compressor, it is known to utilize an economizer circuit. The use of an economizer cycle provides system performance enhancement under certain conditions by tapping off a portion of a refrigerant flow downstream of a condenser. The tapped refrigerant is passed through a separate economizer expansion device, and then passes through an economizer heat exchanger along with the main refrigerant flow. The tapped refrigerant cools the main refrigerant flow, such that the main refrigerant flow has a greater cooling capacity when it reaches the evaporator. The tapped refrigerant is returned to the compressor at an intermediate point in the compression cycle. Furthermore, economizer cycles provide extra steps of unloading, closely matching capacity requirements as well as improve system reliability, enhance operation control and reduce life-cycle cost of equipment due to decreased number of system shutdowns. Furthermore, when an economizer cycle is combined with various means of compressor unloading, even greater benefits can be achieved. Although economizer circuits provide additional benefits to a refrigerant cycle as described above, the economizer circuits have not been incorporated into refrigerant cycles having tandem compressors, where some compressors are designed to have an intermediate injection port and some compressors are conventional non-economized compressors. SUMMARY OF THE INVENTION In the disclosed embodiment of this invention, a refrigerant cycle is provided with tandem compressors delivering a compressed refrigerant to a common discharge manifold, and receiving a refrigerant from a common suction manifold. For instance, if a pair of tandem compressor is considered, one of the two compressors is provided with an economizer port connected and an economizer circuit, and the other is provided in a conventional non-economized configuration. A control for the combined compressors provides variations in capacity for the refrigerant cycle by turning one or both of the compressors on or off, and operating the economized compressor either in economized or non-economized mode. In specific applications, the economizer return line is also branched downstream of an economizer shutoff valve into an unloader line, and into an economizer injection port. The unloader line is provided with an unloader valve. Thus, the compressor that can be operated in economized operation is also capable of being unloaded. The present invention thus provides much of the capacity control capabilities of an economized tandem compressor, without the expense of providing separate economizer circuits for each of the two compressors. These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a refrigerant cycle incorporating the present invention. FIG. 2 is a schematic view of a second option. FIG. 3A is a schematic view of another option. FIG. 3B is a schematic view of another option. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A refrigerant cycle 20 is illustrated in FIG. 1 having a control 21 for operating two tandem compressors 22 and 24. As shown, the compressors 22 and 24 have individual discharge lines 26 leading to a common discharge manifold 28. Downstream of discharge manifold 28 is a condenser 30. A main flow line 32 downstream of the condenser 30 is branched into a refrigerant tap 34, which passes through an economizer expansion device 36. The tapped refrigerant and the refrigerant in the main flow line 32 both pass through an economizer heat exchanger 38. The main refrigerant in line 32 then passes through an expansion device 40 and an evaporator 42. As is known, the economizer circuit provides greater cooling capacity to the refrigerant main flow in line 32 when it reaches the evaporator 42. From the evaporator 42, the refrigerant enters a common suction manifold 43, and eventually individual suction lines 44 and 46 heading back to the compressors 22 and 24, respectively. The economizer return line 44 passes through an economizer shutoff valve 45. From shutoff valve 45, the economized return line communicates to an optional unloader line 48 communicating with the suction line 46 and passing through an unloader valve 52. It should be noted that the shutoff value can also be located in the liquid portion of the economized cycle on a refrigerant tap line 34. The shut off value can also be made as part of an expansion device 40. An economizer injection line 50 communicates the refrigerant back to the compressor 24. If valve 52 is closed and valve 45 is opened, then economized operation will occur, and the refrigerant from line 44 will be returned to the compressor 22 through line 50. If unloader valve 52 is opened and valve 45 is closed, then refrigerant is by-passed from an intermediate point in the compression chambers of compressor 24 back through the open valve 52 to the suction line 46. In case both valve 45 and 52 are open, the refrigerant from economizer line 43 and from line 50 is combined and delivered to suction line 46. Obviously, if both valves 45 and 52 are closed, conventional non-economized operation is executed. Control 21 is able to provide several levels of capacity, namely both compressors can be operated in non-economized operation. If a greater cooling capacity is desired, then compressor 24 can be operated in economized mode. If a lesser capacity is desired, then compressor 24 can be operated in any of the unloaded modes described above. Of course, either one or both compressors can be shut down to provide even further gradations in the number of capacities available from the tandem compressors 22 and 24. The present invention thus provides a tandem compressor arrangement for a refrigerant cycle, wherein economized operation provides enhanced system capabilities, however, the system implementation does not require full expense of providing separate economized circuits and additional costs associated with a compressor that has additional design provisions to accommodate an intermediate injection port for each compressor 22 and 24. Also, the concept of multiple compressors, with less than all having economized operation extends to cycles with more than two compressors. As can be appreciated from FIG. 1, the compressors 23 and 24 may be connected by a pressure equalization line to equalize the pressure within the shells. Further, an oil equalization line for a similar purpose of equalizing oil between the two compressors may be included. FIG. 2 shows another option 80, wherein there are three or more compressors. In option 80, two of the compressors, compressor A and compressor C are not provided with the economized mode and the unloader function. Rather, only compressor B is provided with the economized mode and the unloader function. This concept can extend to even greater numbers of compressors, wherein any number are provided with the economized mode and the unloader operation, and a plurality of others are not. FIG. 3A shows another embodiment 90, wherein compressors B and C are both provided with the economized operation and the unloader function, and only compressor A is not. This concept can extend to even greater numbers of compressors, wherein a number are not provided with the economized mode and the unloader, and a plurality are. In the FIG. 3A embodiment 90, a single economizer heat exchanger 38 delivers refrigerant to the compressors B and C. In the FIG. 3B embodiment 190, it is clear that separate economizer heat exchangers 38, and economizer expansion devices 36 are associated with each compressor B and C. Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates to a refrigerant cycle having tandem compressors, wherein only some of the compressors are provided with economizer ports and can be utilized within an economizer cycle. Tandem compressor refrigerant cycles are known, and have two or more compressors compressing refrigerant and delivering it to a common discharge manifold. Similarly, these compressors are drawing refrigerant from a common suction manifold. In some arrangements, oil equalization lines connecting oil sumps of the tandem compressors for oil management and suction pressure equalization lines connecting shells of the tandem compressors are employed. Tandem compressors provide flexibility to a refrigerant cycle designer, such as allowing additional levels of capacity control by turning off some of the compressors. Moreover, in some applications that would require a very large single compressor, tandem compressors provide design options, availability, and potential cost savings. In refrigerant cycles having a single compressor, it is known to utilize an economizer circuit. The use of an economizer cycle provides system performance enhancement under certain conditions by tapping off a portion of a refrigerant flow downstream of a condenser. The tapped refrigerant is passed through a separate economizer expansion device, and then passes through an economizer heat exchanger along with the main refrigerant flow. The tapped refrigerant cools the main refrigerant flow, such that the main refrigerant flow has a greater cooling capacity when it reaches the evaporator. The tapped refrigerant is returned to the compressor at an intermediate point in the compression cycle. Furthermore, economizer cycles provide extra steps of unloading, closely matching capacity requirements as well as improve system reliability, enhance operation control and reduce life-cycle cost of equipment due to decreased number of system shutdowns. Furthermore, when an economizer cycle is combined with various means of compressor unloading, even greater benefits can be achieved. Although economizer circuits provide additional benefits to a refrigerant cycle as described above, the economizer circuits have not been incorporated into refrigerant cycles having tandem compressors, where some compressors are designed to have an intermediate injection port and some compressors are conventional non-economized compressors. | <SOH> SUMMARY OF THE INVENTION <EOH>In the disclosed embodiment of this invention, a refrigerant cycle is provided with tandem compressors delivering a compressed refrigerant to a common discharge manifold, and receiving a refrigerant from a common suction manifold. For instance, if a pair of tandem compressor is considered, one of the two compressors is provided with an economizer port connected and an economizer circuit, and the other is provided in a conventional non-economized configuration. A control for the combined compressors provides variations in capacity for the refrigerant cycle by turning one or both of the compressors on or off, and operating the economized compressor either in economized or non-economized mode. In specific applications, the economizer return line is also branched downstream of an economizer shutoff valve into an unloader line, and into an economizer injection port. The unloader line is provided with an unloader valve. Thus, the compressor that can be operated in economized operation is also capable of being unloaded. The present invention thus provides much of the capacity control capabilities of an economized tandem compressor, without the expense of providing separate economizer circuits for each of the two compressors. These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. | 20040130 | 20051018 | 20050804 | 98236.0 | 0 | NORMAN, MARC E | REFRIGERANT CYCLE WITH TANDEM ECONOMIZED AND CONVENTIONAL COMPRESSORS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,769,320 | ACCEPTED | Cleaning assembly for a shaft | A cleaning assembly for a shaft or a tubular structure such as a telescopic cylinder, which comprises a sealing joint between an outer tubular element and an inner tubular member in translation inside the outer tubular element, a pipe wiper, and a blade positioned in series in relation to the pipe wiper, wherein the blade has a sharp cutting edge and is mounted by adjusting a tool angle thereof and a pressure it creates on an outer surface of the inner tubular member so that when sliding on this outer surface it scraps contaminants such as organic and mineral material off. | 1. A cleaning assembly for a structure made of a series of tubular sections arranged in a tubular housing, each of the tubular sections comprising a inner tubular member displaceable in an outer tubular member respectively, said cleaning assembly comprising: at least one blade mounted between said inner tubular member and said outer tubular member; wherein a tool angle of said at least one blade and a pressure said at least one blade creates on an outer surface of said inner tubular member are adjusted by a compressive joint to continuously scrape contaminants off said outer surface. 2. The cleaning assembly according to claim 1, wherein said compressive joint is a rubber joint. 3. The cleaning assembly according to claim 1, wherein said at least one blade is made in a hard material selected in the group consisting of a tool steel and a coated steel. 4. The cleaning assembly according to claim 1, wherein said contaminants are selected in the group consisting of mineral materials and organic materials. 5. The cleaning assembly according to claim 1, wherein the outer surface of the inner tubular member is nitrided and said pressure is of at least 10 lb/po. 6. The cleaning assembly according to claim 1, further comprising at least one pipe wiper mounted between said inner tubular member and said outer tubular member, said at least one blade being mounted in series with said at least one pipe wiper between said inner tubular member and said outer tubular member. 7. A cylinder head having an outer tubular member and an inner tubular member displaceable therein, comprising: at least one sealing joint mounted between the outer tubular element and the inner tubular member; a pipe wiper mounted between the outer tubular member and the inner tubular member further toward an open end thereof in relation to said at least one sealing joint, and at least one blade positioned in series and further toward the open end in relation to said pipe wiper; wherein at least one part of an exterior surface of the inner tubular member is hardened and said at least one blade contacts said at least one part of the exterior surface of the inner tubular member with a pressure of at least 10 lb/po. 8. The cylinder according to claim 7, wherein said scrapping contact between the at least one blade and the at least one part of the exterior surface of the inner tubular member is adjusted by adjusting, by compression of a joint, a tool angle of the blade relative to said at least one part and said pressure exerted by the blade on said at least one part. 9. The cylinder according to claim 7, wherein said pressure exerted by the blade is adjusted by means of a compressive joint. 10. The cylinder according to claim 7, wherein said blade is made in a hard material selected in the group consisting of a tool steel and a coated steel. 11. The cylinder according to claim 7, wherein at least one part of an exterior surface of the inner tubular member is hardened by nitridation. 12. The cylinder according to claim 7, further comprising discharge apertures on a periphery of the outer tubular element thereof to evacuate the scraped contamination. 13. The cylinder according to claim 7, wherein the contaminants are selected in the group consisting of organic materials and mineral materials. | FIELD OF THE INVENTION The present invention relates to shafts. More specifically, the present invention is concerned with a cleaning assembly for a shaft. BACKGROUND OF THE INVENTION Telescopic cylinders consist of a series of telescopically arranged tubular sections with a cap closing a first end of each section. A second end of each section is mounted with a two-piece cylinder head while an inner tubular member has a plunger pin eye which threads into the tube section. The cylinder heads are threadedly mounted to an outer wall at the second end of each section; they are provided with dynamic and static seal means for sealing and with scraper means for removing debris from a surface along which the dynamic seal means slidably contacts. Industrial telescoping cylinders may be exposed to a wide range of contaminants, especially when provided on refuse collection trucks or garbage compactors for example. In refuse collection trucks, organic or mineral substances tend to adhere and accumulate on exposed surfaces of the vehicles, such as surfaces of sections of cylinder heads of the telescoping cylinders, where they cook under the action of heat. Such substances stick to surfaces of the cylinder heads and result in rapid damages of the sealing joints thereof, which may result in premature spills and leaks. Benjamin et al., in the patent no. U.S. Pat. No. 4,168,837, disclose a scraper ring for a shaft, which has a scraping edge formed by pinching or piercing a brass member. Wyse, in the patent no. U.S. Pat. No. 4,577,362, describes a scraper ring formed of two semicircular mating sections made of a metal such as brass or bronze, or formed of a rigid high strength plastic material, intended to clean a piston rod of a hydraulic cylinder exposed to dirt, mud and ice for example. Such scraper rings are not satisfactory in application involving industrial telescoping cylinders that are exposed to the wide range of contaminants cooked on a tubular surface as discussed hereinabove. Therefore, there is a need in the art for an improved cleaning assembly for a shaft such as a cylinder member. SUMMARY OF THE INVENTION More specifically, in accordance with the present invention, there is provided a cleaning assembly for a structure made of a series of tubular sections arranged in a tubular housing, each of the tubular sections comprising an inner tubular member displaceable in an outer tubular member respectively, the cleaning assembly comprising at least one blade mounted between the inner tubular member and the outer tubular member; wherein a tool angle of the at least one blade and a pressure the at least one blade creates on an outer surface of the inner tubular member are adjusted by a compressive joint to continuously scrape contaminants off the outer surface of the inner tubular member. There is further provided a cylinder head having an outer tubular member and an inner tubular member displaceable therein, comprising at least one sealing joint mounted between the outer tubular element and the inner tubular member; a pipe wiper mounted between the outer tubular member and the inner tubular member further toward an open end thereof in relation to the at least one sealing joint, and at least one blade positioned in series and further toward the open end in relation to the pipe wiper; wherein at least one part of an exterior surface of the inner tubular member is hardened and the at least one blade contacts the at least one part of the exterior surface of the inner tubular member with a pressure of at least 10 lb/po. Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of embodiments thereof, given by way of example only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the appended drawings: FIG. 1 is a partial cross-sectional view of a telescopic cylinder; FIG. 2 is a perspective view of an assembly according to an embodiment the present invention; and FIG. 3 is an exploded view of the assembly of FIG. 1. DESCRIPTION OF EMBODIMENTS OF THE INVENTION Generally stated, there is provided a cleaning assembly for a shaft or a tubular structure. For clarity purposes, the invention will be described in relation to a structure made of a series of series of tubular sections telescopically arranged in a tubular housing, each of the tubular sections having one end provided with a cylinder head, and comprising a inner tubular member telescopically displaceable in an outer tubular member respectively, such as a telescopic cylinder for example, intended for use in contaminated environments. As illustrated in FIG. 1, a telescopic cylinder comprises a series of tubular sections 12. Each tubular section 12 has one end provided with a cylinder head 13, and comprises an inner tubular member 18 telescopically displaceable in an outer tubular member 24. As best seen in FIGS. 2 and 3, the structure comprises a cylinder head 28 with an outer wall having an enlarged annular portion 30; a pipe wiper 32 separated, by U-cup 37, to a blade 34 inserted into an O-ring joint 36. The pipe wiper 32 is lodged in a corresponding circumferencial recess in an inner wall of the cylinder head 28, with a sealing joint 38 and a wear ring 40 providing a sealing wall, as is well known in the art. The blade 34 is positioned in series in relation to the pipe wiper 32. It is secured by a flange 42 against a lateral surface of the enlarged annular portion 30 of the cylinder head 28, for example by screws 44 as shown in FIGS. 2 and 3, so that it slides on an outer surface of an inner tubular member 46, thereby scraping contamination such as organic material or mineral material thereof without allowing them to accumulate on a cutting edge of the blade 34. The blade is selected to have a sharp cutting edge. The blade is made in a material characterized by a high hardness, such as a material suitable for making cutting tools like a tool steel of a steel M2 type. Alternatively, a coated steel with a hard coating and auto lubricating and anti-adhesive properties, such as D.L.C (Diamond Like Carbon) may be used. DLC are known to have a small coefficient of friction and an excellent surface smoothness; the degree of hardness of the DLC coating is 3,500 to 4,000 HV, and the abrasion resistance is excellent. DLC coatings are known for combining wear resistance, linked to hardness, and self-lubricating capacity. Other hard coatings may be contemplated. A tool angle of the blade 34 and a pressure it is in contact on the outer surface of the inner tubular member with are adjusted by controlling a compression of the rubber joint element 36 such as a nitrile O-ring joint, so that the pressure exerted by the blade on the outer surface of the inner tubular member 46 is at least 10 lb/po. Such a blade proves to be very efficient in scrapping away cooked organic and mineral contaminants from the outer surface of the tubular members. In combination with such a cleaning assembly comprising such a scraper blade, the outer surface of the tubular member to be cleaned is previously submitted to a hardening treatment such as a nitriding treatment, so as to obtain a higher superficial hardness and an increased resistance to fatigue and surface rubbing, in such a way that a surface finish of the tubular member may be protected against an aggressive action of the scraper blade. It is found that the blade of the present cleaning assembly is able to cut away surface defects such as dents or imperfections on such a hardened surface without damaging the surface finish thereof. People in the art will appreciate that the mounting of the blade may take into account mechanical stability of the overall cylinder assembly, since vibrations for example are to be controlled. In operation, when the tubular members are telescopically displaced, the pipe wiper, thus protected by a strong blade as described hereinabove, performs a finish work of the outer surface of the inner tubular member by scraping any remaining contamination away outside of the cylinder, after the blade has scrapped off a main part of the contaminants. In absence of the blade, these contaminants easily go under a lip of the pipe wiper and are therefore swallowed by the cylinder. The blade prevents such contaminants to enter the cylinder. As best seen in FIG. 2, discharge apertures 56 may be provided on a periphery of the cylinder head 28 to evacuate the contamination scraped off by the blade 32. The blade proves to be very efficient in systematically cleaning away organic contamination from the surface of the cylinder. It may be contemplated to provide a plurality of blades in series, for example secured by the flange 52, to even increase the scraping efficiency. Alternatively, in a further embodiment of the present invention, a cylinder head may comprise a sealing joint or a series of two sealing joints between an outer tubular element thereof and an inner tubular member thereof, and a pipe wiper. The pipe wiper may be made in urethane and the sealing joint of P.T.F.E (polytetrafluoroethylene) and bronze, or the pipe wiper in P.T.F.E-bronze and the sealing joint of P.T.F.E and carbon fibres for example. Pipe wipers and sealing joints in hydrogenated nitrile (HNBR) may also be used. The surface finish of the cylinder is selected according to specifications associated with selected pipe wipers as is well known in the art. It is found that such a cleaning assembly allows a protection against contamination by allowing a tubular surface to be continuously cleaned of contaminants. Contaminants may comprise organic materials and plastic materials for example. Although the present invention has been described hereinabove by way of embodiments thereof, it can be modified, without departing from the nature and teachings thereof as defined herein. | <SOH> BACKGROUND OF THE INVENTION <EOH>Telescopic cylinders consist of a series of telescopically arranged tubular sections with a cap closing a first end of each section. A second end of each section is mounted with a two-piece cylinder head while an inner tubular member has a plunger pin eye which threads into the tube section. The cylinder heads are threadedly mounted to an outer wall at the second end of each section; they are provided with dynamic and static seal means for sealing and with scraper means for removing debris from a surface along which the dynamic seal means slidably contacts. Industrial telescoping cylinders may be exposed to a wide range of contaminants, especially when provided on refuse collection trucks or garbage compactors for example. In refuse collection trucks, organic or mineral substances tend to adhere and accumulate on exposed surfaces of the vehicles, such as surfaces of sections of cylinder heads of the telescoping cylinders, where they cook under the action of heat. Such substances stick to surfaces of the cylinder heads and result in rapid damages of the sealing joints thereof, which may result in premature spills and leaks. Benjamin et al., in the patent no. U.S. Pat. No. 4,168,837, disclose a scraper ring for a shaft, which has a scraping edge formed by pinching or piercing a brass member. Wyse, in the patent no. U.S. Pat. No. 4,577,362, describes a scraper ring formed of two semicircular mating sections made of a metal such as brass or bronze, or formed of a rigid high strength plastic material, intended to clean a piston rod of a hydraulic cylinder exposed to dirt, mud and ice for example. Such scraper rings are not satisfactory in application involving industrial telescoping cylinders that are exposed to the wide range of contaminants cooked on a tubular surface as discussed hereinabove. Therefore, there is a need in the art for an improved cleaning assembly for a shaft such as a cylinder member. | <SOH> SUMMARY OF THE INVENTION <EOH>More specifically, in accordance with the present invention, there is provided a cleaning assembly for a structure made of a series of tubular sections arranged in a tubular housing, each of the tubular sections comprising an inner tubular member displaceable in an outer tubular member respectively, the cleaning assembly comprising at least one blade mounted between the inner tubular member and the outer tubular member; wherein a tool angle of the at least one blade and a pressure the at least one blade creates on an outer surface of the inner tubular member are adjusted by a compressive joint to continuously scrape contaminants off the outer surface of the inner tubular member. There is further provided a cylinder head having an outer tubular member and an inner tubular member displaceable therein, comprising at least one sealing joint mounted between the outer tubular element and the inner tubular member; a pipe wiper mounted between the outer tubular member and the inner tubular member further toward an open end thereof in relation to the at least one sealing joint, and at least one blade positioned in series and further toward the open end in relation to the pipe wiper; wherein at least one part of an exterior surface of the inner tubular member is hardened and the at least one blade contacts the at least one part of the exterior surface of the inner tubular member with a pressure of at least 10 lb/po. Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of embodiments thereof, given by way of example only with reference to the accompanying drawings. | 20040130 | 20101012 | 20050210 | 97286.0 | 0 | CHIN, RANDALL E | CLEANING ASSEMBLY FOR A SHAFT | SMALL | 0 | ACCEPTED | 2,004 |
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10,769,346 | ACCEPTED | Method for manufacturing MEMS structures | A method for forming a free standing micro-structural member including providing a substrate; blanket depositing a first sacrificial resist layer over the substrate; exposing and developing the first sacrificial resist layer to form a first resist portion; subjecting the first resist portion to at least a hard bake process to form the first resist portion having a predetermined first smaller volume compared to a desired final resist portion volume; blanket depositing at least a second sacrificial resist layer followed by exposure, development and the at least a hard bake process to form the final resist portion volume; and, depositing at least one structural material layer over the final resist portion. | 1. A method for forming a free standing micro-structural member comprising the steps of: providing a substrate; forming a first sacrificial resist layer over the substrate; patterning the first sacrificial resist layer to form a first resist portion; subjecting the first resist portion to at least a first hard bake process to form the first resist portion having a first volume; forming at least a second sacrificial resist layer followed by patterning and conducting at least a second hard bake process to form a final resist portion having a final volume; and, depositing at least one structural material layer over the final resist portion. 2. The method of claim 1, wherein the at least a first hard bake process further comprises one of a prior or at least partially simultaneous exposure to polymeric cross-linking inducing radiant energy. 3. The method of claim 2, wherein the radiant energy comprises ultraviolet light having a wavelength of less than about 350 nm. 4. The method of claim 2, wherein the ultraviolet light further comprises a radiation intensity between 50 mJ/cm2 and 200 mJ/cm2, a radiation temperature between 150° C. and 250° C., and a radiation time between 10 and 60 minutes. 5. The method of claim 2, wherein exposure to the polymeric cross-linking inducing radiant energy is carried out prior to the hard bake step comprising a thermal heating step. 6. The method of claim 2, wherein exposure to the polymeric cross-linking inducing radiant energy is carried out at least during a portion of the hard bake process. 7. The method of claim 1, wherein the hard bake process comprises a baking temperature of from about 250° C. to about 350° C. 8. The method of claim 1, wherein the first smaller volume is smaller compared to the desired final resist portion volume by about 5% to about 50%. 9. The method of claim 1, further comprising the step of removing resist comprising the final resist portion according to at least one of an ashing process and a wet stripping process to form a free-standing structural member. 10. The method of claim 1, wherein the structural material is selected from the group consisting of metals, nitrides, oxides, carbides, and titanates. 11. The method of claim 1, wherein the structural material is selected from the group consisting of metals, metal nitrides, refractory metals, refractory metal nitrides, oxides, carbides, and piezo-electric oxides. 12. A method for forming a free standing micro-structural member comprising the steps of: providing a substrate; forming a first sacrificial resist layer over the substrate; patterning the first sacrificial resist layer to form a first resist portion; subjecting the first resist portion to at least a first post treatment process to form the first resist portion having a first volume; forming at least a second sacrificial resist layer followed by patterning and conducting at least a second post treatment process to form a final resist portion having a final volume; and, depositing at least one structural material layer over the final resist portion. 13. A method for forming a free standing micro-structural member over a resist portion with improved dimensional tolerances comprising the steps of: providing a substrate; forming a first resist layer over the substrate; patterning the first resist layer to form a first resist portion having a predetermined first volume smaller compared to a predetermined final resist portion volume; subjecting the first resist portion to a first curing process comprising deep UV irradiation and thermal heating for a predetermined period to harden the first resist portion; forming at least a second resist layer having a predetermined thickness over the first resist portion followed by patterning and a second curing process to form the final resist portion volume; depositing at least one structural material layer over the final resist portion; and, removing the final resist portion according to at least one of an ashing and a wet stripping process to form a free standing structural member. 14. The method of claim 13, wherein the first and second curing processes comprise exposure to the deep UV irradiation prior to the thermal heating period. 15. The method of claim 13, wherein the first and second curing processes comprise exposure to the deep UV irradiation during at least a portion of the thermal heating period. 16. The method of claim 13, wherein the thermal heating period comprises a temperature of from about 250° C. to about 350° C. 17. The method of claim 13, wherein the first volume is smaller compared to the final resist portion volume by about 5% to about 50%. 18. The method of claim 13, wherein the first volume is smaller compared to the final resist portion volume from about 10% to about 33%. 19. The method of claim 13, wherein the first smaller volume comprises sidewall portions formed having a smaller dimension by a factor of about ½ compared to a smaller thickness dimension. 20. The method of claim 13, wherein the structural material is selected from the group consisting of metals, metal nitrides, refractory metals, refractory metal nitrides, oxides, carbides, and metal titanates. | FIELD OF THE INVENTION This invention generally relates to manufacturing micro-electro-mechanical systems (MEMS) and more particularly a method of for manufacturing MEMS structural components according to sacrificial resist patterning methods. BACKGROUND OF THE INVENTION Increasingly, there is a demand for the fabrication of 3-dimensional micron-scale components for micro-electro-mechanical systems (MEMS). Micro-electro-mechanical devices include structures of generally conventional shape and function, e.g., beams, posts levers, wheels, and the like, but of a size that is on the scale of hundreds of microns or smaller. As the general name implies, MEMS often incorporate electro-mechanical elements as sensors and/or actuators including optical components such as electro-mechanical mirrors and the like. In one approach to fabricating MEMS structural components a 3-dimensional sacrificial resist mold is formed on a substrate for depositing a structural material. Generally, micro-lithographic techniques conventional in micro-integrated circuit fabrication have been used to form shaped structures on substrates. The adaptation of semiconductor manufacturing techniques has also been favored because silicon has been found to be a useful material for making MEMS. In addition, other structural materials, such as metals, oxides and nitrides have been used for forming MEMS structural components. Generally, the approach includes successive steps of applying a sacrificial resist layer, patterning the resist layer, and forming a structure corresponding to the pattern. The MEMS structures may be formed by either etching a substrate according to the patterned resist layer or by depositing a structural material over the patterned sacrificial resist layer to form a 3-dimensional structure on the substrate surface. Successive stages of patterned deposition and etching may be used to form arrays of larger 3-dimensional MEMS structures. A particular problem encountered in MEMS manufacture, which is not so often experienced in fabrication of semiconductor devices is the need to provide vertical dimensions and aspect ratios with greater tolerances than those commonly demanded in the fabrication of semiconductor devices. One problem in using sacrificial resists is the tendency of the sacrificial resist to shrink in volume upon curing the resist, including a hard bake process following exposure and development of the resist. As a result, the mass volume of the patterned resist is reduced, altering the critical dimensions of the patterned resist in unpredictable and uncontrollable ways and compromising the critical dimensions of the subsequently formed MEMS structure. For example, referring to FIG. 1A, is shown a patterned resist layer portion 12 formed over substrate 10. Referring to FIG. 1B, is shown the patterned resist layer portion 12 following a curing process including a hard bake where sidewall portions e.g., 12B are recessed due to resist shrinkage. Referring to FIG. 1C, subsequent deposition of the structural forming layer 14 results in a thinned structural layer e.g., 14B along the sidewalls, resulting in a deformed structural portion compromising design constraints including mechanically weakening the overall structure. Accordingly, there is a need in the MEMS fabrication art for an improved method to form structural components with improved dimensional accuracy and mechanical integrity including fabricating free-standing structures with high aspect ratios. It is therefore an object of the invention to provide in the MEMS fabrication art an improved method to form structural components with improved dimensional accuracy and mechanical integrity including fabricating free-standing structures with high aspect ratios, in addition to overcoming other shortcomings of the prior art. SUMMARY OF THE INVENTION To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention provides a method for forming a free standing micro-structural member. In a first embodiment the method includes providing a substrate; blanket depositing a first sacrificial resist layer over the substrate; exposing and developing the first sacrificial resist layer to form a first resist portion; subjecting the first resist portion to at least a hard bake process to form the first resist portion having a predetermined first smaller volume compared to a desired final resist portion volume; blanket depositing at least a second sacrificial resist layer followed by exposure, development and the at least a hard bake process to form the final resist portion volume; and, depositing at least one structural material layer over the final resist portion. These and other embodiments, aspects and features of the invention will be better understood from a detailed description of the preferred embodiments of the invention which are further described below in conjunction with the accompanying Figures. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A-1C are representational cross sectional views of a portion of a MEMS structure at stages of manufacture according to the prior art. FIGS. 2A-2E are representational cross sectional views of a portion of an exemplary are representational cross sectional views of a portion of a MEMS structure at stages of manufacture according to an embodiment of the present invention. FIG. 3 is a process flow diagram including several embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Although the method of the present invention is explained by exemplary reference to a rectangularly shaped structure including sidewall portions, it will be appreciated that the method of the present invention may be adapted to any shaped MEMS structural component where sacrificial resist layers may be advantageously used as a sacrificial mold for depositing a structural material thereover. It will additionally be appreciated that successive stages of the method of the present invention may be repeated to form a larger 3-dimensional structure including an array of 3-dimensional structures. Referring to FIG. 2A, a first sacrificial resist layer is deposited and patterned by conventional means to form a patterned first sacrificial resist layer portion 22 over substrate 20. The first sacrificial resist layer portion 22 is formed at a predetermined smaller volume dimension than the desired final resist portion volume dimension for subsequent structural material deposition thereover. For example, the first sacrificial resist layer portion 22 is deposited by a conventional spin coating process, for example including any conventional photoresist including DUV and DNQ novolak I-line photoresist. Following spin-coating, the resist is subjected to a soft bake at a temperature range of 85° C. to about 125° C. to drive off a portion of the solvents and impart dimensional stability to the photoresist. Following the soft bake, the photoresist layer is aligned and exposed through a mask by conventional methods. Following exposure, the resist is preferably subjected to a post-exposure bake (PEB) to further drive off solvents to leave less than about 10% solvents in the resist. For deep ultraviolet (DUV) resists the PEB process is critical in order to catalyze a chemical reaction and make the resist soluble in the developer. Preferably, the PEB process is carried out from about 5° C. to about 20° C. higher than the soft-bake process. Following the PEB process, the resist is developed by conventional process, for example using conventional tetra-methyl-ammonium-hydroxide (TMAH) containing developer formulations to leave the patterned first sacrificial resist layer portion 22. Still referring to FIG. 2A, preferably, the first sacrificial resist layer portion 22 is patterned such that following development it is formed with a volume smaller than that of the desired final resist portion volume (thickness, width and depth dimension) from about 5% to about 50% smaller in volume, more preferably from about 10% to about 33% smaller in volume. For example in the case of a rectangular first sacrificial resist layer portion e.g., 22 the width (and depth) defining sidewall portions are formed at a smaller dimension difference value S1 compared to the final desired width (or depth) dimension S, S1 having a value of about ½ compared to the smaller thickness dimension value T1, T1 being the difference compared to the final desired thickness dimension T. For example, if the smaller dimension value T1 compared to the desired final dimension T is smaller by about 1 micron, the sidewall portions have a width (or depth) formed at a smaller dimension difference value, S1, smaller by about 0.5 microns compared to the desired final dimension S, such that the total smaller dimension difference value (2×S1) for the width and depth portions is about the same as the smaller dimension difference value T1, e.g., about 1 micron. It will be appreciated that the smaller dimensional difference values for S1 and T1 will vary depending on the width or depth of the resist layer portion 22 and the degree of shrinkage expected following a hard bake process, for example from about 1% to about 10% of the width or depth dimension. In addition, the desired tolerances of the structural member to be formed by structural material deposition over the resist layer portion e.g., 22 following a UV/hard bake process according to an embodiment of the invention, will determine the size of the smaller dimension values as well as determining whether more than one additional sacrificial resist layer deposited over the resist layer portion 22 will be necessary to achieve desired tolerances as explained below. Referring to FIG. 2B, following the developing process, the first sacrificial resist layer portion 22 is subjected to at least a hard bake process, more preferably both a UV exposure, preferably deep UV (e.g., less than about 350 nm), and a subsequent or simultaneous hard bake process from about 250° C. to about 350° C. For example, exposure to UV, preferably deep UV, promotes polymeric cross-linking reactions at the surface of the resist, forming a hardened resist shell (surface portion) thereby preventing distortion of at least the UV exposed portion while allowing a higher hard bake temperature without causing flowing and distortion of the resist portion, e.g., upper surface portion 22A. The higher temperature tolerance to resist flow is important in subsequent structural material layer deposition over the sacrificial resist layer portions as deposition temperatures can reach up to about 200° C. Nevertheless, as seen in FIG. 2B, the sidewall portions e.g., 22B, of the first sacrificial resist layer portion 22 tend to ‘cave in’ due to volume (mass) loss (shrinkage) caused by volatization of a remaining portion of solvents present in the resist and limited hardened shell development at the sidewall portions due to limited deep UV exposure. In one embodiment, the hard bake (thermal heating) step is carried out following a deep UV exposure step, or simultaneously with at least a portion of the deep UV exposure step step. The s application of polymeric cross-linking inducing irradiant energy (e.g. deep UV irradiation) during at least a portion of the heating step, for example, initiating UV irradiation either prior to or following initiating of the heating step, preferably prior to initiation of the heating step can be optimized to allow partial outgassing prior to formation of the hardened resist shell at the resist surface thereby preventing undesired localized swelling of resist portions or bursting of resist bubbles formed during resist outgassing. Optionally, the resist temperature may be ramped up to a baking temperature at about 10° C./min to about 30° C./min, preferably a baking temperatures from about 250° C. to about 350° C. following or at least partially simultaneously with irradiation of the resist with deep UV light. Alternatively, the resist portion may be first subjected to deep UV irradiation for a predetermined period followed by heating (hard baking) the resist layer at the baking temperature, for example from about 10 minutes to about 60 minutes. Referring to FIG. 2C, following the UV/hard bake process, at least a second sacrificial resist layer portion 24 is deposited over the first sacrificial resist layer portion 22. The same sequence of processes is then followed as outlined for the first sacrificial resist layer portion 22, e.g., soft bake, exposure, PEB, development, and UV/hard bake processes. For example in one embodiment, the second sacrificial resist layer portion 24 is deposited to a thickness such that following the UV/hard bake processes, the volume or dimensional values e.g., S2 and T2 of the second sacrificial resist layer portion 24 together with the first sacrificial resist layer portion 22 together make up a desired final resist portion dimension or volume. In another embodiment, the second sacrificial resist layer portion 24 may be formed such that following the same processes as for the first sacrificial resist layer portion 24, e.g., soft bake, exposure, PEB, development, and UV/hard bake, the resist portion has dimensions that remain smaller than the desired final resist portion dimensions or volume, for example making up about ½ of the difference between the final desired dimensions and the first sacrificial resist layer portion 22 dimensions. Thereafter, the process is repeated with deposition of a subsequent, e.g., third sacrificial resist layer portion (not shown) with the same processing steps to make up a final desired resist portion dimension or volume following a UV/hard bake process. Since the formation of a hardened shell at the resist portion surfaces from UV exposure may be not fully effective on the sidewall portions due to light shadowing effects of adjacent resist portions (not shown), a degree of resist shrinkage along the sidewall portions of the subsequently deposited resist layer portions e.g., 24 will occur following a hard bake process, for example, from about 1% to about 7%. Depending on the thickness of a subsequent sacrificial resist layer to be deposited to approach a desired final resist portion volume and the desired dimensional tolerances desired for the subsequent structural material layer to be deposited, the subsequent sacrificial resist layer (e.g., second sacrificial resist layer e.g., 24) may desirably be deposited to a thickness with a dimensional volume smaller than the desired final resist portion dimensional volume. Following a hard bake process, a subsequent sacrificial resist layer (e.g., third sacrificial resist layer) is deposited over the second sacrificial layer portion e.g., 24 and subjected to the same processes, e.g., soft bake, exposure, PEB, development, and UV/hard bake, to achieve a desired final resist portion dimension or volume. Referring to FIG. 2D, following formation of the resist layer portions e.g., 22 and 24, to reach a desired final resist portion volume, a blanket deposition process is carried out to deposit a structural material layer 26 over the last deposited resist layer e.g., 24. For example the structural material layer 26 may be any structural material used for MEMS structures including single or multiple layers of metals, metal nitrides, refractory metals, refractory metal nitrides, oxides, carbides, and piezo-electric oxides such as PZT, a solid solution of lead titanate and lead zirconate e.g., (Pb (Ti, Zr)O3. For example, the structural material layer 26 is preferably deposited at a temperature lower than a softening point of the resist layer portion, for example about 210° C. For example, a low temperature CVD or PECVD processes using organo-metallic precursors or physical vapor deposition (PVD) processes process may be used where the deposition rate is controlled to keep the heating of the photoresist layer below a softening point. In addition, an electrochemical plating (ECP) process preceded by PVD deposition of a seed layer may suitably be used to deposit a metal. The thickness of the structural material layer 26 will of course depend on the structure formed, for example considerations of strength, stiffness and resonant frequency will typically dictate the desired thickness of the structural material layer 26. Referring to FIG. 2E, following deposition of the structural material layer 26, an opening may be formed to expose a portion of the resist layer portion e.g., 22 And 24, for example the substrate 20, e.g., silicon, may be etched through from the backside to form a backside opening portion e.g., 28. A resist removal process, preferably an oxygen containing ashing process is then used to remove the resist layer portions e.g., 22 and 24 to leave a free standing structural member 26. For example an oxygen ashing process may be used alone or in conjunction with a conventional wet stripping process as is known in the art of integrated circuit manufacturing. Referring to FIG. 3 is a process flow diagram including several embodiments of the method of the present invention. In process 301, a first sacrificial resist layer is blanket deposited over a substrate and patterned to form a first resist volume portion having a smaller dimension (volume) than a final desired dimension (volume). In process 303, the first resist volume portion is subjected to irradiant energy (e.g., deep UV) to induce polymeric cross-linking and thermal heating (hard bake) inducing resist volume shrinkage and hardening. In process 305, at least one additional (subsequent) sacrificial resist layer is blanket deposited over the first resist volume portion and patterned to approach or reach a predetermined (final) total resist volume portion. In process 307 the subsequent resist volume portion is subjected to a subsequent irradiant energy (e.g., deep UV)/thermal heating (hard bake) step to achieve a predetermined desired resist volume portion (dimension). In process 309, at least one layer of a structural material is blanket deposited over the resist layer portion. In process 311, the resist portion is removed to leave a free-standing structural material portion. Thus, a method has been presented for forming free-standing structural portions to desired dimensional constraints by using at least two sacrificial resist layers to form a resist portion (mold) for subsequent structural material deposition thereover thereby reducing the dimensional variations in the structural portions due to resist shrinkage in a resist patterning and curing process. As a result, free-standing structures, including MEMS structures may be formed to tighter dimensional tolerances with improved structural and mechanical integrity. The preferred embodiments, aspects, and features of the invention having been described, it will be apparent to those skilled in the art that numerous variations, modifications, and substitutions may be made without departing from the spirit of the invention as disclosed and further claimed below. | <SOH> BACKGROUND OF THE INVENTION <EOH>Increasingly, there is a demand for the fabrication of 3-dimensional micron-scale components for micro-electro-mechanical systems (MEMS). Micro-electro-mechanical devices include structures of generally conventional shape and function, e.g., beams, posts levers, wheels, and the like, but of a size that is on the scale of hundreds of microns or smaller. As the general name implies, MEMS often incorporate electro-mechanical elements as sensors and/or actuators including optical components such as electro-mechanical mirrors and the like. In one approach to fabricating MEMS structural components a 3-dimensional sacrificial resist mold is formed on a substrate for depositing a structural material. Generally, micro-lithographic techniques conventional in micro-integrated circuit fabrication have been used to form shaped structures on substrates. The adaptation of semiconductor manufacturing techniques has also been favored because silicon has been found to be a useful material for making MEMS. In addition, other structural materials, such as metals, oxides and nitrides have been used for forming MEMS structural components. Generally, the approach includes successive steps of applying a sacrificial resist layer, patterning the resist layer, and forming a structure corresponding to the pattern. The MEMS structures may be formed by either etching a substrate according to the patterned resist layer or by depositing a structural material over the patterned sacrificial resist layer to form a 3-dimensional structure on the substrate surface. Successive stages of patterned deposition and etching may be used to form arrays of larger 3-dimensional MEMS structures. A particular problem encountered in MEMS manufacture, which is not so often experienced in fabrication of semiconductor devices is the need to provide vertical dimensions and aspect ratios with greater tolerances than those commonly demanded in the fabrication of semiconductor devices. One problem in using sacrificial resists is the tendency of the sacrificial resist to shrink in volume upon curing the resist, including a hard bake process following exposure and development of the resist. As a result, the mass volume of the patterned resist is reduced, altering the critical dimensions of the patterned resist in unpredictable and uncontrollable ways and compromising the critical dimensions of the subsequently formed MEMS structure. For example, referring to FIG. 1A , is shown a patterned resist layer portion 12 formed over substrate 10 . Referring to FIG. 1B , is shown the patterned resist layer portion 12 following a curing process including a hard bake where sidewall portions e.g., 12 B are recessed due to resist shrinkage. Referring to FIG. 1C , subsequent deposition of the structural forming layer 14 results in a thinned structural layer e.g., 14 B along the sidewalls, resulting in a deformed structural portion compromising design constraints including mechanically weakening the overall structure. Accordingly, there is a need in the MEMS fabrication art for an improved method to form structural components with improved dimensional accuracy and mechanical integrity including fabricating free-standing structures with high aspect ratios. It is therefore an object of the invention to provide in the MEMS fabrication art an improved method to form structural components with improved dimensional accuracy and mechanical integrity including fabricating free-standing structures with high aspect ratios, in addition to overcoming other shortcomings of the prior art. | <SOH> SUMMARY OF THE INVENTION <EOH>To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention provides a method for forming a free standing micro-structural member. In a first embodiment the method includes providing a substrate; blanket depositing a first sacrificial resist layer over the substrate; exposing and developing the first sacrificial resist layer to form a first resist portion; subjecting the first resist portion to at least a hard bake process to form the first resist portion having a predetermined first smaller volume compared to a desired final resist portion volume; blanket depositing at least a second sacrificial resist layer followed by exposure, development and the at least a hard bake process to form the final resist portion volume; and, depositing at least one structural material layer over the final resist portion. These and other embodiments, aspects and features of the invention will be better understood from a detailed description of the preferred embodiments of the invention which are further described below in conjunction with the accompanying Figures. | 20040130 | 20070213 | 20050804 | 62423.0 | 0 | NGUYEN, TUAN H | METHOD FOR MANUFACTURING MEMS STRUCTURES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,769,354 | ACCEPTED | Lead screw and gear box for use with a motorized adjustable seat back and exhibiting a nut and nylon spacer bushing in abutting engagement with a slotted catcher bracket for preventing end-play of the lead screw as well as buzz, squeak and rattle in tensile and compressive loading situations | A powered seat assembly for reducing end-play of an associated lead screw interconnecting a pivotally secured seat back to a motor gear box. A motor actuates the lead screw through an input to the motor gear box and in order to pivotally readjust the seat back. The seat assembly includes a base plate, the seat back pivotally securing to a forward location of the base plate, the motor gear box securing to a rearward location. A bracket secures to an intermediate location of the base plate, a slot defined in an extending portion of the bracket defining a passage therethrough for the lead screw. A spacer bushing is supported upon the lead screw and adheres against a face of the bracket opposite the pivotally secured seat back. The spacer bushing absorbs tensile loading forces applied axially along the lead screw and in a direction towards the seat back in order to prevent movement of the lead screw in and out of the motor gear box as well as preventing the occurrence of buzz, squeak and rattle noises accompanied by metal-to-metal contact within the assembly. | 1. A powered seat assembly for reducing end-play of an associated lead screw interconnecting a pivotally secured seat back to a motor gear box, a motor actuating the lead screw through an input to the motor gear box and in order to pivotally readjust the seat back, said assembly comprising: a base plate, the seat back pivotally securing to a forward location of said base plate, the motor gear box securing to a rearward location of said base plate; a bracket secured to an intermediate location of said base plate, a slot defined in an extending portion of said bracket defining a passage therethrough for the lead screw; and a spacer bushing supported upon the lead screw and adhering against a face of said bracket opposite the pivotally secured seat back, said spacer bushing absorbing tensile loading forces applied axially along the lead screw and in a direction towards the seat back in order to prevent movement of the lead screw in and out of the motor gear box. 2. The powered seat assembly as described in claim 1, further comprising said spacer bushing exhibiting a diameter greater than a width associated with said slot, said spacer bushing being constructed of a material different than that associated with said bracket. 3. The powered seat assembly as described in claim 2, said spacer bushing being constructed of a nylon material. 4. The powered seat assembly as described in claim 2, further comprising a threadably engaged retention nut abutting against a facing side of said spacer bushing opposite said bracket. 5. The powered seat assembly as described in claim 2, said spacer bushing exhibiting an arcuate shaped contact surface relative to said bracket and slot. 6. The powered seat assembly as described in claim 2, said spacer bushing further comprising a two-piece nut assembleable from opposite sides of said bracket and through said slot. 7. The powered seat assembly as described in claim 6, said slot defining an inner sidewall passage in said extending bracket portion and which exhibits an end-most and enlarged portion for permitting assembly of said two-piece nut. 8. The powered seat assembly as described in claim 7, said two-piece nut exhibiting a specified shape and size and being constructed of a synthetic material. 9. The powered seat assembly as described in claim 8, said assembleable nut exhibiting a specified shape and size and further comprising a Nylok nut. 10. The powered seat assembly as described in claim 1, further comprising said slotted bracket and a motor gearbox support portion being integrated into a single component secured to said baseplate. 11. The powered seat assembly as described in claim 1, said bracket having a specified shape and size and being constructed of a metal, said spacer bushing exhibiting an arcuate shaped contact surface relative to said bracket and associated slot and being constructed of a plastic based synthetic material. 12. A powered seat assembly for reducing end-play of an associated lead screw interconnecting a pivotally secured seat back to a motor gear box, a motor actuating the lead screw through an input to the motor gear box and in order to pivotally readjust the seat back, said assembly comprising: a base plate, the seat back pivotally securing to a forward location of said base plate, the motor gear box securing to a rearwardly disposed support portion of said base plate; a bracket secured to an intermediate location of said base plate, a slot defined in an extending portion of said bracket defining a passage therethrough for the lead screw; and a spacer bushing supported upon the lead screw and adhering against a face of said bracket opposite the pivotally secured seat back, said spacer bushing being constructed of a plasticized synthetic material and exhibiting an arcuate shaped contact surface relative to said bracket and extending slot to absorb tensile loading forces applied axially along the lead screw and in a direction towards the seat back to prevent movement of the lead screw in an out of the motor gear box. 13. A powered seat assembly for reducing end-play of an associated lead screw interconnecting a pivotally secured seat back to a motor gear box, a motor actuating the lead screw through an input to the motor gear box and in order to pivotally readjust the seat back, said assembly comprising: a base plate, the seat back pivotally securing to a forward location of said base plate, the motor gear box securing to a rearwardly disposed support portion of said base plate; a component secured to a face of said base plate and comprising a first extending bracket portion proximate an intermediate location of said base plate, a slot defined in said extending portion and defining a passage therethrough for the lead screw, a further extending portion of said component defining a motor gearbox support; and a spacer bushing supported upon the lead screw and adhering against a face of said bracket opposite the pivotally secured seat back, said spacer bushing being constructed of a plasticized synthetic material and exhibiting an arcuate shaped contact surface relative to said bracket and extending slot, a nut threadably engaging against an opposite facing surface of said spacer bushing and so that said bushing absorbs tensile loading forces applied axially along the lead screw and in a direction towards the seat back to prevent movement of the lead screw in and out of the motor gear box. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to motorized vehicle seat back adjustment devices, in particular of the type incorporating a lead screw extending between a gear box arrangement and a pivotally associated seat back. More specifically, the present invention incorporates a reinforced and arcuate shaped catcher bracket, through which the lead screw extends, and in combination with an adjustable nut and nylon spacer bushing. The present design operates to relieve buzz, squeak and rattle conditions typically associated with such prior art gearbox arrangements in tensile loading situations and which result from free-play of the lead screw in directions in and out of the gearbox. Additionally, the present design transfers tensile and compressive loads from the gear box to the catcher bracket. This increases the fatigue life of the assembly as well as increase the amount of load the assembly is able to withstand. 2. Description of the Prior Art The prior art is well documented with various examples of motorized powered seat back mechanisms, such as which in particular are utilized inside of a vehicle. Many such seat assemblies include the provision of a threaded lead screw and which interconnects a pivotally associated seat back with a power supplying gearbox arrangement. A common problem encountered in such existing seatback arrangements is the existence of free-play movement (also known as endplay) of the lead screw in directions in and out of the gearbox, this directly contributing to an increase in arm looseness and deflection. In particular, the gearbox arrangement includes the provision of a plastic worm gear, seating about a periphery of the lead screw at its inserting end, and in contact with a metal drive shaft associated with an electric motor input. Free play movement of the lead screw typically results from the failure of the assembly to maintain either a separation or a constant contact between an inserted end face of the lead screw and a base abutment surface associated with the gearbox. Other examples of prior art powered vehicle seat adjusters include such as that illustrated in U.S. Pat. No. 5,575,531, issued to Gauger et al., and which teaches a rotatable drive shaft with first and second axial ends and an intermediate arcuate portion connecting the first and second axial ends. The first and second axial ends are respectively axially connected to a drive motor gear assembly and to a driven lead screw. A horizontal drive block threadingly engaging the lead screw is rotatably and vertically translatingly mounted in an aperture in a lower track for self-alignment of the drive block with respect to the lead screw. A housing rotatably receives the axial connection between one end of the drive shaft and the lead screw. The bearing block is rotatably and translatingly mounted in a bracket fixed to an upper track for self-alignment of the drive shaft with the lead screw. A rivet block engages the lead screw and is mounted for rotation and translation in a link. The upper and lower tracks have a guide section and an abutment section which .collapse together in a self-cinching action under force loading to resist separation of the upper and lower tracks. U.S. Pat. No. 5,203,608, issued to Tame, teaches a seat assembly with an articulating seat cushion rotatable about a transverse axis near the front end of the seat cushion. The seat back is reclinable and is coupled to the rear of the seat cushion so as to raise the rear end of the seat cushion in response to rearward reclining of the seat back, whereby the seat occupant's hip point is raised as the seat back is reclined to provide a more comfortable recliner. The recliner drive mechanism includes a lead screw with a motor/transmission assembly to drive the lead screw and includes a thrust washer carried by the lead screw to transfer axial loads on the lead screw directly to the motor mount rather than allowing the lead screw to be transferred to the internal components of the motor/transmission assembly. U.S. Pat. No. 6,322,146, issued to Fisher, Jr., teaches a seat recliner which controllably adjusts the angular position of a seat back relative to a seat base structure and is responsive to remote actuation by an operator. The recliner includes a driven mechanism adapted to be connected to the seat back, a drive mechanism rotatable in a first and second direction, and a transmission assembly operably interconnecting the drive mechanism and the driven mechanism. The transmission assembly includes a gear retainer assembly and a mounting assembly. The mounting assembly is adapted to be connected to one of the seat base and seat back. The gear retainer assembly includes a gear housing formed of a polymeric material and adapted to accommodate the drive and driven mechanisms for operative interconnection, whereby rotation of a transmission rod in the first or second direction causes a recliner rod to move relative to the housing in a corresponding first and second linear direction. SUMMARY OF THE PRESENT INVENTION The present invention is a motorized vehicle seat back adjustment device incorporating a lead screw extending between a gear box arrangement and a pivotally associated seat back, and. which in particular includes a reinforced and arcuate shaped catcher bracket combined with an adjustable nut and nylon spacer bushing. As stated previously, the present design operates to relieve buzz, squeak and rattle conditions typically associated with such prior art gearbox arrangements and in addition to free-play (or end-play) of the lead screw in directions in and out of the gearbox. Additionally, the present design transfers tensile and compressive loads from the gear box to the catcher bracket. This increases the fatigue life of the assembly as well as increase the amount of load the assembly is able to withstand. A motor actuates the lead screw through an input to the motor gear box and in order to pivotally readjust the seat back. The seat back is pivotally secured to a forward location of the base plate, whereas the motor gear box secures to a rearwardly disposed support portion of the base plate. A component secured to a face of the base plate includes an extending bracket portion, located proximate an intermediate location of said base plate. A slot is defined in the extending portion and defining a passage therethrough for the lead screw. A further variant of the present invention combines the slotted bracket portion and motor gearbox support into a single component attachable to the base plate. A spacer bushing is supported upon the lead screw and in adhering fashion against a face of the bracket opposite the pivotally secured seat back. The spacer bushing is constructed of a plasticized synthetic material and exhibits an arcuate shaped contact surface relative to the bracket and extending slot. An advantage of constructing the spacer bushing of a nylon material is that it avoids metal to metal contact, relative to the slotted bracket portion, and thereby to avoid buzz, squeak and rattle conditions attendant to such metal to metal contact. A nut is threadably engaged against an opposite facing surface of the spacer bushing and so that the bushing absorbs tensile and compressive loading forces applied axially along the lead screw and in a direction towards the seat back to prevent end-play movement of the lead screw in an out of the motor gear box. Additional variants include reconfiguring the spacer bushing as a two-piece assembleable nut, such as in particular a Nylok nut and which is assembleable from opposite sides of the lead screw supporting bracket. The slot associated with the bracket, and through which the lead screw extends, exhibits an end-most and enlarged portion for permitting assembly of the two-piece nut. BRIEF DESCRIPTION OF THE DRAWINGS Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which: FIG. 1 is a side view of a motorized seatback arrangement and illustrating the arcuate configured catcher bracket, secured to the seat back base plate, and in combination with the nylon spacer bushing and supporting nut according to a first preferred embodiment of the present invention; FIG. 2 is a cutaway illustration taken along line 2-2 of FIG. 1 and showing from another perspective the abutting engagement of the nylon spacer element against metal surface of the spacer bracket; FIG. 3 is a side view of a motorized seatback arrangement according to a second preferred embodiment of the present invention and by which the arcuate catcher bracket and motor support bracket are combined into a single frame component; FIG. 4 is a perspective view of the bracket illustrated in the plan view of FIG. 3; FIG. 5 is a sectional view of an alternate variant of the present invention and by which an alternately configured and two piece assembleable nylon nut is applied to the lead screw and in sliding engagement with an alternately configured catcher bracket; and FIG. 6 is a cutaway view taken along line 6-6 of FIG. 5 and showing an end face illustration of a slotted and arcuately configured portion defined within the catcher bracket in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, a motorized vehicle seat back adjustment device is illustrated at 10 according to a first preferred embodiment of the present invention. In particular, and as previously argued, the present invention incorporates an improved tensile and compressive loading arrangement for relieving buzz, squeak and rattle conditions associated with end play movement of a lead screw relative to an attached electric motor gearbox arrangement. A single seat adjustment assembly is illustrated at 10 in FIG. 1, it being understood that a pair of such assemblies may be located on either of first and second sides of a vehicle seat (not shown). As best illustrated in FIG. 1, the seat assembly includes a base plate 12 having a specified shape and exhibiting a substantially planar surface. An elongated and externally threaded lead screw is illustrated at 14 and includes a first end secured within a hollow tubular portion 16 (see FIG. 1) in turn pivotally associated, at 18, with a seat back 20. A main pivot 22 is established about which the seat back 20 pivots relative to the base plate 12. In one preferred variant, the seat back 20 is capable of rotating approximately 109° relative to the seat bottom (or base plate 12). A second end of the lead screw 14 is in turn seated within a motor gear box 24, which is in turn secured to a rear end location of the base plate 12. The motor gear box 24 is typically constructed of a plastic material and seats the inserting end of the lead screw 14 by virtue of an interengaging worm gear (not shown). An output drive shaft associated with an electric motor, also not shown, engages the motor gear box to actuate the lead screw in first and second threadably rotated/axially translated directions and in order to pivot the seat back 20 about the main pivot 22. A reinforced and arcuate shaped catcher bracket is illustrated at 26 and secures to a surface of the base plate 12 at an intermediate location between the first and second ends of the lead screw 14. The catcher bracket 26 is secured to the base plate 12, such as by rivets 28 or the like, and includes an arcuate extending portion 30. A lengthwise extending slot 32 is defined in the arcuate extending portion 30, see again FIG. 1, and facilitates the traversing motion of the screw 14 relative to the gearbox 24 further such that the lead screw 14 extends through the slot 32. A spacer bushing is illustrated at 34 and such as more specifically is provided as a nylon or other synthetic material to contrast with the metal construction of the spacer bracket 26. The spacer bushing 34 is illustrated in FIG. 1 as exhibiting a substantially saucer or arcuate shape and, in combination with a threaded nut 36 secured against an opposite face of the bushing 34, abuts against the arcuate extending portion 30 proximate to the perimeter edges defined about the slot 32. A problem with existing gearbox and lead screw arrangements has to do with the material inconsistencies between the metal screw and the plastic components associated with the gearbox. In particular, the interconnection between the inserting end of the lead screw 14 and the plastic worm gear component in the motor gear box interior is facilitated by various over-molding processes. The lead screw 14 by itself exhibits fairly high load capabilities, however this is lowered considerably by the properties associated with the plastic motor gear box 24. It has further been determined that, while fairly strong in compression, tension forces applied to the lead screw 14, relative to the gear box 24 and in a direction towards the seat back 20, cause free-play movement, or end play, between the lead screw 14 and the gearbox 24. This is further a result of the failure to maintain a consistent contact between the inserted end face of the lead screw 14 and the associated seating location of the gear box 24. As stated previously, the present design operates to relieve conditions typically associated with such prior art gearbox arrangements and which result from free-play movement of the lead screw 14 in directions in and out of the gearbox 24. The provision of the synthetic (nylon) spacer bushing 34 is further such that the tension forces normally imparted by the seat back 20, upon the motor gear box 24, are instead applied between the spacer 34 and the corresponding slotted perimeter edges of the arcuate extending bracket portion 30. The configuration and arrangement of the spacer 34, with its substantially disk-shape configuration, combined with the arcuate profile of the bracket extending portion 30 (see again FIG. 1) allows for higher rearward torque retention (or tension loading resistance) at the location of the catcher bracket 26, and as opposed to these loads being applied to the gear box 24. A further advantage is derived by the nylon to metal contact between the spacer bushing 34 and the surface of the arcuate extending portion 30, this in turn avoiding the undesirable aspects of buzz, squeak and rattle which would otherwise be associated with metal-to-metal contact, and with the attendant loss in customer perception of quality. Referring now to FIG. 3, a general illustration is shown at 38 of a powered seat assembly according to a further preferred embodiment of the present invention. The seat assembly 38 includes numerous components also identically disclosed in the first preferred embodiment at 10 in FIGS. 1 and 2, these being identically referenced. Referring also to FIG. 4, a bracket component 40 is illustrated and which combines the features of a modified bracket portion 42, with slot 44, as well as a further rearward portion 46, at which the motor gear box 24 is installed (see again FIG. 3). The bracket 40 includes additional mounting locations 48, 50 (5), 52, 54 and 56 for securing to the base plate surface 12, as shown in FIG. 3, and in order to substitute for the bracket 26 and gear box 24 to base plate 12 engagement configuration of FIG. 1. Consistent with that shown in FIG. 1, a spacer bushing 34 and backing nut 36 are again secured to the lead screw 14 and abut against an inner facing surface associated with the modified bracket portion 42 of the component 40. Referring finally to FIGS. 5 and 6, an alternate arrangement is shown of spacer bushing exhibiting a two-piece nut, see components 58 and 60 assembleable from opposite sides of the arcuate bracket and through its associated slot. It is understood that, for purposes of the explanation of FIGS. 5 and 6, the arcuate bracket portion and associated slot can be incorporated into those illustrated in either of the embodiments of FIGS. 1 and 3 and such that a slot 62 defining an inner sidewall passage in extending bracket portion 64 exhibits an end-most and annularly enlarged portion 66 for permitting initial assembly of the two-piece nut. As is further known, the two-piece nut assembly 58 and 60 can exhibit any specified shape and size and is again preferably constructed of a suitable synthetic material, such as a Nylok® material or the like. The assembleable and combination bushing and nut provides a chuck control feature to the invention and includes the steps of threading the nut portion 58 onto the lead screw 14, which is then slid into the key slot opening, see portion 66. The bushing portion 60 of the nut is then staked against the nut portion 58 to stake the end of the lead screw into operating position, the nut controlling chuck movement in both directions. Having described our invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains and without deviating from the scope of the appended claims: | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to motorized vehicle seat back adjustment devices, in particular of the type incorporating a lead screw extending between a gear box arrangement and a pivotally associated seat back. More specifically, the present invention incorporates a reinforced and arcuate shaped catcher bracket, through which the lead screw extends, and in combination with an adjustable nut and nylon spacer bushing. The present design operates to relieve buzz, squeak and rattle conditions typically associated with such prior art gearbox arrangements in tensile loading situations and which result from free-play of the lead screw in directions in and out of the gearbox. Additionally, the present design transfers tensile and compressive loads from the gear box to the catcher bracket. This increases the fatigue life of the assembly as well as increase the amount of load the assembly is able to withstand. 2. Description of the Prior Art The prior art is well documented with various examples of motorized powered seat back mechanisms, such as which in particular are utilized inside of a vehicle. Many such seat assemblies include the provision of a threaded lead screw and which interconnects a pivotally associated seat back with a power supplying gearbox arrangement. A common problem encountered in such existing seatback arrangements is the existence of free-play movement (also known as endplay) of the lead screw in directions in and out of the gearbox, this directly contributing to an increase in arm looseness and deflection. In particular, the gearbox arrangement includes the provision of a plastic worm gear, seating about a periphery of the lead screw at its inserting end, and in contact with a metal drive shaft associated with an electric motor input. Free play movement of the lead screw typically results from the failure of the assembly to maintain either a separation or a constant contact between an inserted end face of the lead screw and a base abutment surface associated with the gearbox. Other examples of prior art powered vehicle seat adjusters include such as that illustrated in U.S. Pat. No. 5,575,531, issued to Gauger et al., and which teaches a rotatable drive shaft with first and second axial ends and an intermediate arcuate portion connecting the first and second axial ends. The first and second axial ends are respectively axially connected to a drive motor gear assembly and to a driven lead screw. A horizontal drive block threadingly engaging the lead screw is rotatably and vertically translatingly mounted in an aperture in a lower track for self-alignment of the drive block with respect to the lead screw. A housing rotatably receives the axial connection between one end of the drive shaft and the lead screw. The bearing block is rotatably and translatingly mounted in a bracket fixed to an upper track for self-alignment of the drive shaft with the lead screw. A rivet block engages the lead screw and is mounted for rotation and translation in a link. The upper and lower tracks have a guide section and an abutment section which .collapse together in a self-cinching action under force loading to resist separation of the upper and lower tracks. U.S. Pat. No. 5,203,608, issued to Tame, teaches a seat assembly with an articulating seat cushion rotatable about a transverse axis near the front end of the seat cushion. The seat back is reclinable and is coupled to the rear of the seat cushion so as to raise the rear end of the seat cushion in response to rearward reclining of the seat back, whereby the seat occupant's hip point is raised as the seat back is reclined to provide a more comfortable recliner. The recliner drive mechanism includes a lead screw with a motor/transmission assembly to drive the lead screw and includes a thrust washer carried by the lead screw to transfer axial loads on the lead screw directly to the motor mount rather than allowing the lead screw to be transferred to the internal components of the motor/transmission assembly. U.S. Pat. No. 6,322,146, issued to Fisher, Jr., teaches a seat recliner which controllably adjusts the angular position of a seat back relative to a seat base structure and is responsive to remote actuation by an operator. The recliner includes a driven mechanism adapted to be connected to the seat back, a drive mechanism rotatable in a first and second direction, and a transmission assembly operably interconnecting the drive mechanism and the driven mechanism. The transmission assembly includes a gear retainer assembly and a mounting assembly. The mounting assembly is adapted to be connected to one of the seat base and seat back. The gear retainer assembly includes a gear housing formed of a polymeric material and adapted to accommodate the drive and driven mechanisms for operative interconnection, whereby rotation of a transmission rod in the first or second direction causes a recliner rod to move relative to the housing in a corresponding first and second linear direction. | <SOH> SUMMARY OF THE PRESENT INVENTION <EOH>The present invention is a motorized vehicle seat back adjustment device incorporating a lead screw extending between a gear box arrangement and a pivotally associated seat back, and. which in particular includes a reinforced and arcuate shaped catcher bracket combined with an adjustable nut and nylon spacer bushing. As stated previously, the present design operates to relieve buzz, squeak and rattle conditions typically associated with such prior art gearbox arrangements and in addition to free-play (or end-play) of the lead screw in directions in and out of the gearbox. Additionally, the present design transfers tensile and compressive loads from the gear box to the catcher bracket. This increases the fatigue life of the assembly as well as increase the amount of load the assembly is able to withstand. A motor actuates the lead screw through an input to the motor gear box and in order to pivotally readjust the seat back. The seat back is pivotally secured to a forward location of the base plate, whereas the motor gear box secures to a rearwardly disposed support portion of the base plate. A component secured to a face of the base plate includes an extending bracket portion, located proximate an intermediate location of said base plate. A slot is defined in the extending portion and defining a passage therethrough for the lead screw. A further variant of the present invention combines the slotted bracket portion and motor gearbox support into a single component attachable to the base plate. A spacer bushing is supported upon the lead screw and in adhering fashion against a face of the bracket opposite the pivotally secured seat back. The spacer bushing is constructed of a plasticized synthetic material and exhibits an arcuate shaped contact surface relative to the bracket and extending slot. An advantage of constructing the spacer bushing of a nylon material is that it avoids metal to metal contact, relative to the slotted bracket portion, and thereby to avoid buzz, squeak and rattle conditions attendant to such metal to metal contact. A nut is threadably engaged against an opposite facing surface of the spacer bushing and so that the bushing absorbs tensile and compressive loading forces applied axially along the lead screw and in a direction towards the seat back to prevent end-play movement of the lead screw in an out of the motor gear box. Additional variants include reconfiguring the spacer bushing as a two-piece assembleable nut, such as in particular a Nylok nut and which is assembleable from opposite sides of the lead screw supporting bracket. The slot associated with the bracket, and through which the lead screw extends, exhibits an end-most and enlarged portion for permitting assembly of the two-piece nut. | 20040130 | 20070313 | 20050818 | 94666.0 | 0 | BARFIELD, ANTHONY DERRELL | LEAD SCREW AND GEAR BOX FOR USE WITH A MOTORIZED ADJUSTABLE SEAT BACK AND EXHIBITING A NUT AND NYLON SPACER BUSHING IN ABUTTING ENGAGEMENT WITH A SLOTTED CATCHER BRACKET FOR PREVENTING END-PLAY OF THE LEAD SCREW AS WELL AS BUZZ, SQUEAK AND RATTLE IN TENSILE AND COM | SMALL | 0 | ACCEPTED | 2,004 |
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10,769,814 | ACCEPTED | Refrigerator with icemaker | Refrigerator with an icemaker including a cabinet having a mullion wall for compartmentalization of a freezing chamber and a refrigerating chamber, a case provided to a door on the refrigerating chamber, having a cavity therein, a first duct for supplying cold air from a neighborhood of an evaporator in the freezing chamber to the cavity, the icemaker in the cavity for producing ice, an ice container in the cavity for storing the ice, and a dispenser in the door in communication with the cavity, thereby having ice supplied to a user at an outside of the refrigerator through a dispenser provided to the door. | 1. A refrigerator with an icemaker comprising: a cabinet having a mullion wall for compartmentalization of a freezing chamber and a refrigerating chamber; a case provided to a door on the refrigerating chamber, having a cavity therein; a first duct for supplying cold air from a neighborhood of an evaporator in the freezing chamber to the cavity; the icemaker in the cavity for producing ice; an ice container in the cavity for storing the ice; and a dispenser in the door in communication with the cavity. 2. The refrigerator as claimed in claim 1, wherein the case is formed of a thermal insulating material. 3. The refrigerator as claimed in claim 1, wherein the first duct includes; a first part in the door in communication with the cavity, and a second part in the freezing chamber passed through the mullion wall, the second part being in communication with the first part when the door is closed. 4. The refrigerator as claimed in claim 3, wherein the first duct further includes a gasket at a connection part of the first and the second parts when the door is closed. 5. The refrigerator as claimed in claim 1, wherein the first duct includes; a first part in the door in communication with the cavity, and a second part in contact with the mullion wall, and in communication with the first part passed through the mullion wall. 6. The refrigerator as claimed in claim 1, further comprising a first fan adjacent to the evaporator for supplying cold air to the first duct, and a second fan in a bent part of the first duct for turning a flow direction of the cold air. 7. The refrigerator as claimed in claim 1, wherein the first duct includes; a first part provided to the door in communication with the cavity, and a second part provided to a sidewall of the cabinet so as to be in communication with the first part when the door is closed. 8. The refrigerator as claimed in claim 1, wherein the case further includes a hole in communication with the refrigerating chamber. 9. The refrigerator as claimed in claim 1, wherein the case further includes a damper on the hole. 10. The refrigerator as claimed in claim 1, further comprising a second duct having one end arranged adjacent to the evaporator, and the other end arranged in the refrigerating chamber, for supplying the cold air to the refrigerating chamber. 11. The refrigerator as claimed in claim 10, wherein the second duct includes a plurality of through holes in an outside circumferential surface for supplying cold air to the refrigerating chamber. 12. The refrigerator as claimed in claim 11, wherein the second duct includes a louver provided to each of the through holes for guiding a discharge direction of the cold air. 13. The refrigerator as claimed in claim 10, further comprising a damper adjacent to the evaporator for controlling a flow rate of the cold air supplied to the second duct. 14. The refrigerator as claimed in claim 1, further comprising a third duct having one end in communication with the cavity, and the other end in communication with the freezing chamber, for supplying the cold air from the cavity to the freezing chamber. 15. The refrigerator as claimed in claim 14, wherein the third duct includes; a third part provided to the door so as to be in communication with the cavity, and a fourth part in communication with the freezing chamber passed through the mullion wall, and fitted so as to be in communication with the third part when the door is closed. 16. The refrigerator as claimed in claim 15, wherein the third duct further includes a gasket provided to a part where the third part and the fourth part are connected when the door is closed. 17. The refrigerator as claimed in claim 14, wherein the third duct includes; a third part provided to the door so as to be in communication with the cavity, and a fourth part provided to the sidewall of the cabinet, and fitted so as to be in communication with the third part when the door is closed. 18. The refrigerator as claimed in claim 10, further comprising a third duct provided to pass through the mullion wall for supplying the cold air from the cavity to the freezing chamber. | This application claims the benefit of the Korean Application No. P2003-0065163 filed on Sep. 19, 2003, which is hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to refrigerators, and more particularly, to a refrigerator with an icemaker of an improved structure, which can dispense ice pieces from a dispenser provided to a refrigerator door. 2. Background of Related Art The refrigerator is used for long time fresh storage of food. The refrigerator has food storage chambers each of which temperature is maintained in a low temperature state by a refrigerating cycle, for fresh storage of the food. There are a plurality of storage chambers of different characteristics, so that the user can select storage methods suitable for storage of various kinds of food, taking kinds and characteristics of food and required storage time periods into account. Of the storage chambers, the refrigerating chamber and the freezing chamber are typical. The refrigerating chamber is maintained at about 3° C.˜4° C. for long time fresh storage of food and vegetable, and the freezing chamber is maintained at a subzero temperature for long time storage of meat and fish in a frozen state, and making and storage of ice pieces. In general, the refrigerating chamber has a volume greater than the freezing chamber, and the freezing chamber is allocated over the refrigerating chamber. In the meantime, recently, other than the foregoing traditional functions of the refrigerator, the refrigerator has been developed to have a variety of additional functions. For an example, for drinking cold water in the refrigerating chamber, in the related art, the user is required to open the door, and take out a water bottle from the refrigerating chamber. However, recently, a refrigerator provided with a water dispenser to an outside of a refrigerator door is developed, for dispensing cold water cooled down by cold air in the refrigerating chamber, enabling the user supplied with, and drink the cold water at outside of the refrigerator without opening the door. Moreover, refrigerators each having a water purifying function added to the water dispenser are spread. In general, the water dispenser is provided to a door on the refrigerating chamber for easy supplied of water from the refrigerating chamber to an outside of the refrigerator. However, since the refrigerating chamber is allocated under the freezing chamber, the water dispenser can not, but be provided at a relatively low position. According to this, for using the water dispenser, the user is required to bend forward. In the meantime, when the user drinks water, and when the user cooks food, the user uses ice, frequently. For using ice thus, it is required to open the door on the freezing chamber, and separate ice from an ice tray. Moreover, the opening of the door on the freezing chamber for using the ice causes escaping to cold air from the freezing chamber to an outside of the refrigerator, resulting in temperature rise of the freezing chamber, to required more work of the compressor that consumes an energy. SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a refrigerator with an icemaker that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. An object of the present invention is to provide a refrigerator with an icemaker of an improved structure, in which a dispenser is provided at a height convenient for a user. Another object of the present invention is to provide a refrigerator with an icemaker of an improved structure, which can dispense ice to a user at an outside of the refrigerator without opening a door. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these objects and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, the refrigerator with an icemaker includes a cabinet, a case, a first duct, the icemaker, an ice container, and a dispenser. The cabinet includes a mullion wall for compartmentalization of a freezing chamber and a refrigerating chamber. The case is provided to a door on the refrigerating chamber, and has a cavity therein. It is preferable that the case is formed of a thermal insulating material. The first duct provided to pass through the mullion wall for supplying cold air from a neighborhood of an evaporator in the freezing chamber to the cavity. The icemaker is provided in the cavity, and produces ice, and the ice container is provided in the cavity, and stores the ice. The dispenser is provided in the door so as to be in communication with the cavity. The first duct includes a firs part in the door in communication with the cavity, and a second part in the freezing chamber passed through the mullion wall, the second part being in communication with the first part when the door is closed. The first duct further includes a gasket at a connection part of the first and the second parts when the door is closed. The first duct includes a first part in the door in communication with the cavity, and a second part in contact with the mullion wall, and in communication with the first part passed through the mullion wall. The first duct includes a first part provided to the door, and a second part provided to a sidewall of the cabinet so as to be in communication with the first part. The refrigerator may further include a first fan adjacent to the evaporator for supplying cold air to the first duct, and a second fan in a bent part of the first duct for turning a flow direction of the cold air. The case may further include a hole in communication with the refrigerating chamber. The case may further include a damper on the hole. The second duct has one end arranged adjacent to the evaporator, and the other end arranged in the refrigerating chamber, for supplying the cold air to the refrigerating chamber. The second duct includes a plurality of through holes in an outside circumferential surface for supplying cold air to the refrigerating chamber. The second duct includes a louver provided to each of the through holes for guiding a discharge direction of the cold air. The refrigerator further includes a damper adjacent to the evaporator for controlling a flow rate of the cold air supplied to the second duct. In other aspect of the present invention, there is provided a refrigerator with an icemaker including the cabinet, the case, the first duct, a third duct, the icemaker, the ice container, and the dispenser. The third duct has one end in communication with the cavity, and the other end in commmunication with the freezing chamber, for supplying the cold air from the cavity to the freezing chamber. The third duct may include a third part provided to the door so as to be in communication with the cavity, and a fourth part in communication with the freezing chamber passed through the mullion wall, and fitted so as to be in communication with the third part when the door is closed. The third duct may further include a gasket provided to a part where the third part and the fourth part are connected when the door is closed. The third duct may include a third part provided to the door so as to be in communication with the cavity, and a fourth part provided to the sidewall of the cabinet, and fitted so as to be in communication with the third part when the door is closed. In another aspect of the present invention, there is provided a refrigerator with an icemaker including the cabinet, the case, the first duct, the second duct, the third duct, the icemaker, the ice container, and the dispenser. It is to be understood that both the foregoing description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention claimed. BRIEF DESCRITPION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings; FIG. 1 illustrates a diagram of a refrigerator in accordance with a preferred embodiment of the present invention; FIG. 2 illustrates a perspective view of an icemaker provided to the refrigerator in FIG. 1; FIG. 3 illustrates a partial section of the ice maker and the ice container provided to the refrigerator in FIG. 1; FIG. 4 illustrates a diagram showing an operation of the icemaker provided to a refrigerator in FIG. 1; FIG. 5 illustrates a diagram of an improved refrigerator in accordance with a preferred embodiment of the present invention; FIG. 6 illustrates a side section showing a first embodiment of the refrigerator in FIG. 5; FIG. 7 illustrates a side section showing a second embodiment of the refrigerator in FIG. 5; FIG. 8 illustrates a side section showing a third embodiment of the refrigerator in FIG. 5; FIG. 9 illustrates a side section showing a fourth embodiment of the refrigerator in FIG. 5; and FIG. 10 illustrates a front view of a fifth embodiment of the refrigerator in FIG. 5, showing a first and a third ducts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In describing the embodiments, same parts will be given the same names and reference symbols, and repetitive description of which will be omitted. Referring to FIG. 1, though the related art refrigerator has a refrigerating chamber in a lower part thereof and a freezing chamber in an upper part thereof, the refrigerator of the present invention has a freezing chamber 2 in a lower part thereof and a refrigerating chamber 1 in an upper part thereof. Referring to FIG. 1, the refrigerator of the present invention includes a refrigerating chamber 1 in an upper part of the refrigerator, and a freezing chamber 2 in a lower part of the refrigerator. There is a door 1a in a front part of the refrigerating chamber 1, with a water dispenser 3 provided thereto. The water dispenser 3 enables the user to be supplied with cold water directly at an outside of the refrigerator without opening the door 1 a. For this, there is a water tank (not shown) on an inside surface of the door 1a in contact with the refrigerating chamber 1. The water tank stores water, and the water in the water tank is cooled by the cold air in the refrigerating chamber 1. According to this, when the user operates the lever (not shown), the user can be supplied with the cold water from the water tank through the water dispenser 3. Thus, the refrigerator is the refrigerating chamber 1 positioned in the upper part thereof, and the freezing chamber 2 positioned in the lower part thereof. Therefore, the water dispenser 3 can be provided at a waist or breast height of the user. According to this, the user can use the water dispenser 3 very easily and conveniently. In the meantime, the refrigerator of the present invention is provided, not only with the water dispenser 3 for supplying cold water, but also an icemaker 10 for producing and supplying a plurality of ice pieces. The icemaker 10 will be described in more detail with reference to the attached drawings. For reference, FIGS. 2 and FIG. 3 illustrate an icemaker and an ice container provided to the refrigerator in FIG. 1, and FIG. 4 illustrates a diagram showing operations of them. The icemaker 10 and the ice container 20 are provided to the freezing chamber 2 under the refrigerating chamber 2. Referring to FIG. 2, the icemaker 10 includes an ice tray 11, a water supplying part 12, an ejector 14, and a motor 13. As shown in FIG. 2, the ice tray 11 has a semi-cylindrical form with an opened top, for storing water or ice therein. There are a plurality of ribs 11a on an inside surface to divide an inside space thereof into a plurality of spaces. As shown in FIG. 2, the ribs 11a are projected in a radial direction, and enable the ice tray 11 to produce a plurality of ice pieces. As shown in FIG. 2, the water supplying part 12, provided to one side of the ice tray 11, supplies water to the ice tray 11. As shown in FIG. 2, there is a bracket 15 at a rear side of the ice tray 11, for fastening the icemaker 10 to the freezing chamber 2. In the meantime, the ejector 14 includes a shaft 14a, and a plurality of pins 14b. As shown in FIG. 2, the shaft 14a is arranged to cross a center of an upper part of the ice tray 11 in a longitudinal direction. As shown in FIG. 2, the pins 14b are formed on an outside circumferential surface of the shaft 14a substantially perpendicular to the shaft 14a. It is preferable that the pins 14b are formed at regular intervals along a length direction of the shaft 14a, more preferably, one for each of the spaces in the ice tray 11 divided with the ribs 11a. As shown in FIG. 2, the motor 13 is mounted on one point of an outside circumferential surface of the ice tray 11, and is connected to a shaft 14a. According to this, when the shaft 14a rotates by the motor 13, the pins 14b rotate together with the shaft 14a. Then, the pin 14b pushes the ice pieces in the ice tray 11 out to drop the ice pieces below the icemaker 10. Referring to FIG. 3, there are a plurality of strips 16 in a front part of the ice tray 11, i.e., in an upper part of a side opposite to a side the brackets 15 are arranged. The strips 16 are extended from the upper part of the front side of the ice tray 11 to a part close to the shaft 14a, respectively. There is a gap between adjacent strips 16, through which the pins 14b pass when the shaft 14a rotates. In the meantime, the ice pieces in the ice tray 11 are pushed by the pins 14b, separated from the ice tray 11, and drop on the strips 16 after the ice pieces are separated from the ice tray 11, fully. The ice pieces 16 dropped on the strips 16 are dropped below the icemaker 10, and stored in the ice container 20 under the icemaker 10. According to this, top surfaces of the strips 16 are required to guide the ice pieces separated from the ice tray 11, to drop below the icemaker 10, well. Therefore, as shown in FIGS. 2 and 4, in the present invention, it is preferable that the strips 16 are sloped such that parts near to the shaft 14a are higher than the front part of the ice tray 11. A structure is also required for preventing the ice pieces separated from the ice tray 11 by the pins 14b from dropping to a rear side of the ice tray 11. For this, as shown in FIGS. 2 and 4, in the present invention, it is preferable that a rear side end of the ice tray 11 is higher than the shaft 14a, so that the ice pieces moved backward, and separated from the ice tray 11 by the ice tray 11 are guided to a front side of the ice tray 11, and drop on the strips 16, naturally. In the meantime, referring to FIG. 4, there is a heater on an underside of the ice tray 11. The heater 17 heats a surface of the ice tray 11 for a short time period, and melts the ice pieces on a surface of the ice tray 11, slightly. According to this, the ice in the ice tray 11 can be separated easily when the shaft 14a and the pins 14b rotate. Referring to FIGS. 2 and 4, the icemaker 10 is provided with a sensing arm for measuring an amount of ice in the ice container 20. The sensing arm, under the control of a controller (not shown), moves and measures the amount of ice in the ice container 20. For an example, the sensing arm 18 moves down at regular intervals, to move down much when the amount of the ice in the container 20 is small, and opposite to this, to move down little when the amount of the ice in the container 20 is much as the sensing arm 18 hits the ice earlier. According to this, the controller measures the amount of ice in the ice container 20 with reference to a move down depth of the sensing arm 18. In the meantime, referring to FIGS. 3 and 4, the container 20 is arranged below the icemaker 10, and has an opened top for receiving, and storing the ice pieces from the icemaker 10. As shown in FIG. 3, the ice container 20 has a discharge opening 21 in one surface, for an example, in a bottom surface for discharging ice pieces downward. In the meantime, the ice container 20 has a transfer device 22 for transferring the ice pieces in the ice container 20 to a side having the discharge opening 21 formed therein. As shown in FIG. 3, the transfer device 22 has a form of a thread, arranged across the ice container 20. The transfer device 22 is connected to a motor 23, and rotated, to transfer the ice pieces in the ice container 20 toward the discharge opening 21. Referring to FIG. 3, inside of the ice container 20, there is a crusher 30 in a side part having the discharge opening 21 formed therein for crushing the ice transferred by the transfer device 22. The crusher 30 includes a housing 31, a shaft 32, a supporter 33, and blades 34. The housing 31, over the discharge opening 21 in the ice container 20, has an opened side in a side facing the transfer device 22. The shaft 32 is arranged in the housing 31 horizontally, and connected to, and rotate together with, the transfer device 22. The shaft 32 may be fabricated separate from the transfer device 22, and connected to the transfer device 22, or, as shown in FIG. 3, fabricated in a form extended from an end of the transfer device 22. Referring to FIG. 3, the supporter 33 is provided to support the shaft 32 in the housing 31. That is, since the shaft 32 passes the supporter 33, the shaft 32 rotates in the housing 31 together with the transfer device 22. The blades 34, fixed to the shaft, rotates together with the shaft 32, and crushes the ice pieces transferred by the transfer device 22. At least one blade 34 is provided, and, as shown in FIG. 3, when there are a plurality of blades 34, it is preferable that the blades 34 are arranged opposite to each other with respect to the supporter 33. Once the icemaker 10 and the ice container 20 are provided to the freezing chamber 2, a plurality of ice pieces produced from the icemaker 10 is stored in the ice container 20. According to this, without requiring separation of the ice pieces from the ice tray, the user may open the door 2a on the freezing chamber 2, and take out the ice pieces from the ice container 20, which is convenient to the user. However, in this case, it is still not convenient, since opening of the door 2a is required, and frequent opening of the door 2a causes waste of energy, still. Therefore, though not shown in FIG. 1, an ice dispenser may be provided to the door 2a on the freezing chamber 2 of the refrigerator of the present invention. In this instance, the ice dispenser, provided separate from the water dispenser 3, supplies the ice pieces produced in the icemaker 10 and stored in the ice container 20 to the user. To do this, it is preferable that an ice discharging device 40 is provided to the ice container 20, for discharging an appropriate amount of ice, selectively. As shown in FIG. 3, the ice discharging device 40 includes an actuator 42, and a shutter 41. The shutter 41, substantially in a plate form, provided to open/close the discharge opening 21. The shutter 41 is connected to the actuator 42, with, for an example, a lever (not shown). As the actuator, for an example, an actuator of a solenoid type may be used. In the foregoing ice discharging device 40, the actuator 42 is operative in response to a control signal from the controller, and the shutter 41 regulates an amount of opening of the discharging device 21 according to operation of the actuator 42. In the meantime, in the present invention, it is preferable that the ice discharging device 40 provided thus can discharge the ice crushed at the crusher 30, or the ice stored in the ice container 20, selectively. To do this, as shown in FIG. 3, the discharge opening 21 may include a first discharge opening 21a and a second discharge opening 21b, and the shutter 41 is arranged to open the second discharge opening 21b selectively. As shown in FIG. 3, the first discharge opening 21a is formed under the crusher 30, and the second discharge opening 21b is formed under an end part of the transfer device 22 on a side of the crusher 30. Once the discharge opening 21 and the ice discharging device 40 have the forgoing structures, the ice discharging device 40 can discharge crushed, or uncrushed ice selectively, which will be described in more detail. If the user desired to have crushed ice supplied thereto, the second discharge opening 21b is closed with the shutter 41. Then, the ice pieces in the ice container 20 is transferred to the crusher 30 by the transfer device 22, and the ice crushed at the crusher 30 is discharged through the opened first discharge opening 21a. On the other hand, if the user desires the uncrushed ice, the shutter 41 opens the second discharge opening 21b. Then, the ice stored in the ice container is discharged through the second discharge opening 21b before the ice is transferred to the crusher 30. According to this, the user can have the uncrushed ice supplied thereto. In the meantime, the structure in which the crushed or uncrushed ice can be supplied selectively is not limited to above structure. For an example, one discharge opening may be provided, and one shutter regulates an amount of opening of the discharge opening. That is, when the shutter opens the discharge opening slightly, the ice is discharged after being crushed at the crusher 30, and when the shutter opens the discharge opening fully, the ice is discharged as it is without being crushed. The operation of the refrigerator of the present invention will be described. If the controller (not shown) determines that there is shortage of ice in the ice container 20 by the operation of the sensing arm 18, water is supplied to the water supplying part 12 in the ice container 10. The water supplied to the water supplying part 12 in turn fills the spaces between the ribs 11a of the ice tray 11, are frozen by the cold air in the freezing chamber 2. Accordingly, the ice tray 11 can produce the ice pieces of fixed sizes by the ribs 11a. When the ice is formed as a preset time is passed, the heater 17 heats the ice tray 11 for a short while. According to this, the ice on the surface of the ice tray 11 melts slightly, and separated from the ice tray 11. Then, as the motor 13 is put into operation, the shaft 14a and the pins 14b rotate. Then, the pin 14b pushes out the ice between adjacent ribs 11a in a circumferential direction of the ice tray 11 until the ice, separated from the ice tray 11 fully by the pin 14b, drops onto the strip 16, therefrom, below the icemaker 10, and received at the ice container 20. When a preset amount of ice is stuffed in the ice container 20 by repeating above process, the controller stops production of the ice as the sensing arm senses the amount of the ice. Of course, if the sensing arm 18 senses that there is shortage of the ice still, the foregoing process is repeated to produce ice continuously, which is stored in the ice container 20. In the meantime, when the user operates a control panel on an outside surface of the door 2a, in a state the ice is stuffed in the ice container 20, the user can have the crushed, or uncrushed ice supplied thereto through the ice dispenser, which process will be described, hereafter. When the user operates the control panel, to select a function for having the crushed ice supplied thereto, as described before, the shutter 41 closes the second discharge opening 21b a little, or opens the discharge opening 21, a little. Under this state, the motor 23 is rotated, to transfer large sized ice from the ice container 20 to the crusher 30. Then, the ice in the ice container 20 is transferred to the crusher 30, entirely. According to this, the ice crushed in the crusher 30 is discharged through the first discharge opening 21a. Thereafter, the discharged ice is supplied to the user through the ice dispenser. On the other hand, if the user selects a function for having large sized uncrushed ice supplied thereto by operating the control panel, the shutter 41 opens the second discharge opening 21b, or the discharge opening 21, almost fully. Then, the ice transferred to the crusher 30 by the transfer device 22 is discharged through the discharge opening 21 before the ice reaches to the crusher 30, and supplied to the user through the ice dispenser. Thus, the refrigerator of the present invention can dispense crushed, or uncrushed ice selectively. However, the refrigerator of the present invention described with reference to FIGS. 1˜4 has the following disadvantages. First, in the case of the refrigerator having no ice dispenser provided to the door on the freezing chamber, the opening of door for taking out the ice not only is inconvenient, but also wastes energy. Second, in the case of the refrigerator having an ice dispenser provided to the door on the freezing chamber, since the freezing chamber and the ice dispenser are provided to the lower part of the refrigerating chamber 1, the user has inconvenience of taking the ice with bending oneself forward. Third, when the water dispenser, and the ice dispenser are provided, a structure of the refrigerator becomes complicate to cause difficulty in fabrication and to cost high. Moreover, the requirement for distinguishing between the water dispenser and the ice dispenser is not convenient for the user. Accordingly, the present invention provides a refrigerator of improved structure in which the problems of the foregoing embodiments are modified. In the refrigerator of improved structure of the present invention, a dispenser is provided to a door on the refrigerating chamber over the freezing chamber. According to this, the user can use the dispenser very easily, and conveniently. Moreover, the structure enables the user to take water from a water tank in the refrigerating chamber through the dispenser. Thus, the user can take ice or water from a dispenser provided at a height convenient to use, i.e., a height of waist or breast of the user. FIGS. 5 to 10 illustrate the refrigerators of improved structures of the present invention, referring to which the refrigerator of improved structure of the present invention will be described. For reference, FIG. 5 illustrates a diagram of an improved refrigerator in accordance with a preferred embodiment of the present invention, FIGS. 6 to 9 illustrate side sections each showing first to fourth preferred embodiment refrigerator of the refrigerator in FIG. 5 in succession, and FIG. 10 illustrates a front view of a fifth embodiment of the refrigerator in FIG. 5, showing a first and a third ducts. A common structure for the first to fourth embodiment refrigerators of the present invention will be described, with reference to FIGS. 5˜9. Referring to FIGS. 5˜9, there are a freezing chamber 52 in an upper part of the cabinet 50, and a refrigerating chamber 51 in a lower part of the cabinet 50. As shown in FIGS. 6˜9, the refrigerating chamber 52 and the freezing chamber 51 are compartmentalized into independent spaces with a mullion wall 64. Referring to FIGS. 6˜9, the freezing chamber 51 is provided with an evaporator 65. There is a fan adjacent to the evaporator 65. According to this, the cold air formed in the vicinity of the evaporator 65 is supplied to the freezing chamber 51 or the refrigerating chamber 52 by the fan 66. In the meantime, the evaporator 65 is provided, not only in the freezing chamber 51. That is, though not shown, the evaporator 65 can also be provided to the refrigerating chamber 52. Moreover, a plurality of the evaporators 65 may be provided to the refrigerating chamber 52 and the freezing chamber 51, respectively. However, as shown in FIGS. 6˜9, the embodiments will be described, taking a case the evaporator 65 is provided to the freezing chamber 51, as an example. The refrigerating chamber 52 and the freezing chamber 51 are provided with doors 52a and 51a, respectively. The door 52a on the refrigerating chamber 52 is provided with a case 61 and a dispenser 55, and the case 61 has an icemaker 10 and an ice container 20 provided therein. Of course, the ice container 20 may have the transfer device and the crusher described with reference to FIG. 3. Referring to FIGS. 6˜9, the case 61 is provided with a door 52a. The case 61 is formed of a thermal insulating material, for preventing heat exchange between the refrigerating chamber 52 and the cavity 61. The case 61 is provided, for an example, in an upper part of the door 52a, for arranging the dispenser 55 at a height convenient to use, i.e., at a height of waist or breast of an average people using the refrigerator. That is, this is because, if the case 61 is arranged at a high position, an appropriate height ‘H’ for arranging the dispenser 55 which is required to be arranged at a position lower than the case 61 can be secured. Meanwhile, the appropriate height ‘H’ may be set, not with reference to the height of waist or breast of the user, but with reference to other criteria. There is a cavity 61 in the case 61, and the icemaker 10 and the ice container 20 are in the cavity 61. Since structures of the icemaker 10 and the ice container 2 are similar to the structures described with reference to FIGS. 2 and 4, description of which will be omitted. However, as shown in FIGS. 6˜9, the icemaker 10 is arranged in an upper part of the cavity 61, and the ice container 20 is arranged in a lower part of the cavity 61. The ice produced at the icemaker 10 may be dropped down, and stored in the ice container 20. Referring to FIGS. 6˜9, the dispenser 55 is provided to a door 52a on the refrigerating chamber 52. There is an ice chute 54 in the door 52a making the cavity 61 and the dispenser 55 in communication. According to this, the ice can be supplied from the ice container 20 to the user at the dispenser 55 via the ice chute 54. In the meantime, the refrigerator 52 may be provided with a water tank (not shown) for cooling water with the cold air in the refrigerating chamber 52. Since the water tank is in communication with the dispenser 55, the user may have the water, or the ice supplied thereto, selectively. Structural characteristics of the embodiments will be described for each of the embodiments. Referring to FIG. 6, the refrigerator in accordance with a first preferred embodiment of the present invention is provided with a first duct 70 for supplying the cold air formed around the evaporator 65 in the freezing chamber 51 to the cavity 61. The first duct 70 passes the mullion wall 64, and has one end adjacent to the evaporator 65 in the freezing chamber 51, and the other end in communication with the cavity 61. Referring to FIG. 6, the first duct 70 includes a first part 71 and a second part 75. As shown in FIG. 6, the first part is provided to the door 52a, and has one end arranged at a lower end of the door 52a, and the other end in communication with the cavity 61. The second part 75 is provided to the freezing chamber 51 passed through the mullion wall 64, and has one end arranged adjacent to the evaporator 65, and the other end arrange at an upper part of the mullion wall 64. As shown in FIG. 6, the second part 75 is provided to a bottom surface of the mullion wall 64 or a sidewall surface of the freezing chamber 51. If the first duct 70 is provided thus, the evaporator 65 can supply cold air from a neighborhood of the evaporator 65 to the cavity 61. For effective supply of the cold air from the neighborhood of the evaporator 65 to the cavity 61, it is preferable that a first fan 66 is provided as shown in FIG. 6. The first fan 66, arranged between the evaporator 65 and the first duct 70, supplies the cold air from the neighborhood of the evaporator 65 to the first duct 70. In the meantime, as shown in FIG. 6, the duct 70 has a bent part. Therefore, the cold air from the first fan 66 forms turbulence at the bent part, and fails fast supply to the cavity 61. Therefore, as shown in FIG. 6, the refrigerator of the present invention is further provided with a second fan 68. The second fan 68 inside of the bent part of the first duct 70, turns a direction of the cold air flowing in the first duct 70, and supplies to the cavity 61, quickly. The second fan 68 can be, for an example, a cross flow fan that can change an air flow direction substantially perpendicular to a rotation shaft of the fan. For easy mounting and rigid support of the second fan 68, the second fan 68 may be provided to a part having the first duct 70 passed through the mullion wall 64. In the meantime, in the foregoing first duct 70, the first part 71 is separated from the second part 75 when the door 52a is opened, and vice versa. Therefore, for preventing the cold air in the first duct 70 from leaking to an outside of the refrigerator when the door 52a is closed, there is a gasket 70a provided to a connection part of the first part 71 and the second part 75. In the meantime, referring to FIG. 6, the case 60 has a hole 60a for making the refrigerating chamber 52 and the cavity 61 in communication. The hole 60a enables supply of the cold air supplied to the cavity 61 through the first duct 70 to the refrigerating chamber 52. Then, production of the ice as well as cooling of the refrigerating chamber 52 are made possible by using the cold air in the neighborhood of the evaporator 65. It is preferable that the hole 60a is provided to a top of the case 60, because the cold air discharged into the refrigerating chamber 52 through the hole 60a has a temperature lower than the refrigerating chamber 52, and tends to go down. Therefore, if the hole 60a is formed in the top of the case 60, the cold air can be supplied to every part of the refrigerating chamber 52. As shown in FIG. 6, in the case the hole 60a is formed to the case 60 thus, it is preferable that the hole 60a is provided with a damper 60b. The damper 60b closes/opens, or regulates opening of the hole 60a. Once the damper 60b is provided to the hole 60a, the cold air supplied to the cavity 61 can be supplied to the refrigerating chamber 52 only when a temperature of the refrigerating chamber 52 is outside of a preset temperature range. The operation of the refrigerator in accordance with the first preferred embodiment of the present invention will be described. The cold air is blown from the neighborhood of the evaporator 65 to the first duct 70 by the first fan 66. The cold air introduced into the first duct 70 is involved in a flow direction change by the second fan 68, and supplied to the cavity 61. The icemaker 10 produces ice by using the cold air supplied to the cavity 61, and the produced ice is stored in the ice container 20. Since the cold air is supplied to the cavity 61 continuously, the ice stored in the ice container 20 does not melt. The ice stored in the ice container 20 is supplied to the user through the dispenser 55 in an outside surface of the door 52a. Since the dispenser 55 is at the waist or breast height of the user, the user can have the ice supplied thereto without bending oneself forward. In the meantime, if the temperature of the refrigerating chamber 52 is outside of the preset temperature range, the damper 60b on the hole 60a of the case 60 is opened. Therefore, the cold air is supplied from the cavity 61 to the refrigerating chamber 52, to cool down the refrigerating chamber 52 again, to maintain the preset temperature range. In the meantime, when the door 52a is opened thus, the first part 71 of the first duct 70 is separated from the second part 75. Therefore, for preventing the cold air from leaking to the outside of the refrigerator, the first fan 66 and the second fan 68 stop when the door 52a is opened. Next, referring to FIG. 7, the refrigerator in accordance with a second preferred embodiment of the present invention includes a cabinet 50, a case 60, a first duct 70, a second duct 80, the icemaker 10, the ice container 20, and the dispenser 55. Parts other than the second duct 80 are identical to the first embodiment. For an example, the refrigerator in accordance with a second preferred embodiment of the present invention includes all other parts described in the first embodiment, such as the first and second fans 66, and 68, and the damper 60b, and the like. As the refrigerator in accordance with a first preferred embodiment of the present invention is described with reference to FIG. 6, the characteristics of the second embodiment distinctive from the first embodiment, i.e., only the second duct 80 will be described. Referring to FIG. 7, the second duct 80 has one end arranged adjacent to the evaporator 65, and the other end arranged in the refrigerating chamber 52. For this, the second duct 80 passes the mullion wall 64, or, as shown in FIG. 7, an opening is provided to the mullion wall 64, and the second duct 80 is made to be in communication with the opening. The second duct 80 supplies the cold air from a neighborhood of the evaporator 65 to the refrigerating chamber 52, directly. In the meantime, as shown in FIG. 7, it is preferable that the second duct 80 has the other end arranged in an upper part of the refrigerating chamber 52, for moving down the cold air discharged through the other end of the second duct 80 to a lower part of the refrigerating chamber 52, and cooling down every part of the refrigerating chamber 52. In addition to this, for more effective supply of the cold air to every part of the refrigerating chamber 52, there are a plurality of holes 81 in an outside circumferential surface of the second duct 80. As shown in FIG. 7, the plurality of holes 81 are provided at substantially regular intervals along a length direction of the second duct 80. Therefore, the cold air in the second duct 80 can be supplied to every parts of the refrigerating chamber 52 through the holes 81. Referring to FIG. 7, in the second embodiment, the hole 81 has louvers 85, additionally. The louver 85 controls a discharge direction of the cold air supplied to the refrigerating chamber 52 through the holes 81. Therefore, once the louver 85 is provided, the cold air can be supplied to every part of the refrigerating chamber 52, more effectively. In the meantime, in the second embodiment refrigerator, there may be a damper 67 provided thereto for controlling an amount of cold air supplied to the second duct 80. As shown in FIG. 7, the damper 67, provided to an end of the second duct 80, for opening/closing or controlling opening of the one end of the second duct 80. Once the damper 67 is provided thus, the cold air supply to the refrigerating chamber 52 can be stopped when the temperature of the refrigerating chamber 52 is low. A process for supplying cold air in the refrigerator in accordance with the second preferred embodiment of the present invention having the second duct 80 and the first duct 70 provided thereto will be described. When the temperature of the refrigerating chamber 52 reaches to a present temperature range, both of the dampers 60b and 67 are closed. Then, the cold air is supplied from the neighborhood of the evaporator 65 only to the cavity 61. The cold air supplied to the cavity 61 maintains the cavity 61 to be at a subzero temperature, such that, not only the icemaker 10 can produce ice, but also the ice stored in the ice container 20 can be conserved for a long time period. Next, if the temperature of the refrigerating chamber 52 rises to a temperature outside of the preset temperature range, at least one of the dampers 60b and 67 are opened. If both of the dampers 60b and 67 are opened, enabling much of the cold air to flow in the front part and the rear part of the refrigerating chamber 52 uniformly, every part of the refrigerating chamber 52 can be cooled down within a short time period, uniformly. Referring to FIG. 8, the refrigerator in accordance with a third preferred embodiment of the present invention includes the cabinet 50, the case 60, the first duct 70, a third duct 90, the icemaker 10, the ice container 20, and the dispenser 55. Parts except the third duct 90 are identical to the parts described in the first embodiment. In the meantime, the refrigerator in accordance with the third preferred embodiment of the present invention may include all other parts described in the first preferred embodiment, such as the first and second fans 66 and 68, and the damper 60b. As the refrigerator in accordance with a first preferred embodiment of the present invention has been described with reference to FIG. 6, characteristics of the third preferred embodiment of the present invention, distinctive from he first embodiment, i.e., the third duct 90 will only be described. Referring to FIG. 8, the third duct 90 has one end in communication with the freezing chamber 51, and the other end in communication with the cavity 61. The third duct 90 is provided to the case 60, or the door 52a, and passes through the mullion wall 64. The third duct 90 provided thus supplies the cold air from the cavity 61 to the freezing chamber 51. Therefore, since the cold air formed in the neighborhood of the evaporator 65 cools down the freezing chamber 51 again, after cooling down the cavity 61, an energy efficiency can be enhanced. In the meantime, referring to FIG. 8, the third duct 90 includes a third part 91 and a fourth part 95. The third part 91 has one end provided at a lower end of the door 52a, and the other end in communication with the cavity 61. The fourth part 95 passes through the mullion wall 64, and has one end provided on an upper surface of the mullion wall 64, and the other end in communication with the freezing chamber 51. In the third duct 90, the third part 91 is separated from the fourth part 95 when the door 52a is opened, vice versa. Therefore, as shown in FIG. 8, for preventing the cold air from leaking to an outside of the refrigerator when the door 52a is closed, a gasket 90a is provided to a connection part of the third part 91 and the fourth part 75. Since the refrigerator in accordance with a third preferred embodiment of the present invention supplies the cold air to the cavity 61 through the first duct 70, the icemaker 10 can produce the ice by using the cold air supplied to the cavity 61, and the ice container 20 can store the ice. Since the cold air, supplied to the cavity 61, is supplied to the refrigerating chamber 51 through the third duct 90, an energy efficiency can be enhanced. In the meantime, if the refrigerating chamber 52 temperature rises to a temperature outside of the present temperature range, the damper 60b is opened. Therefore, the cold air supplied to the cavity 61 is supplied to the refrigerating chamber 52. In the meantime, referring to FIG. 9, the refrigerator in accordance with a fourth preferred embodiment of the present invention includes the cabinet 50, the case 60, the first duct 70, the second duct 80, the third duct 90, the icemaker 10, the ice container 20, and the dispenser 55. The fourth embodiment refrigerator includes all parts of the first to third embodiment refrigerator, and has all advantages thereof. Since the parts have been described with reference to FIGS. 6˜8, repetitive description of which will be omitted. In the meantime, referring to FIG. 10, the refrigerator in accordance with a fifth preferred embodiment of the present invention has a structure similar to the first to fourth refrigerators respectively, except that parts of the first duct 70 and the third duct 90 are provided to a sidewall of the cabinet 50 respectively, which will be described. The third duct 70 includes a first part 71 provided to the door 52a, and a second part 75 provided to the sidewall of the cabinet 50. The first part 71 is in communication with the cavity 61, and the second part 75 makes the freezing chamber 51 and the first part 71 in communication. The first part 71 and the second part 75 are connected to each other when the door 52a is closed, and there is a gasket 70a at a connection part of the first part 71 and the second part 75 for prevention of the cold air from leaking. The third duct 90 includes a third part 91 provided to the door 52a and a fourth part 95 provided to the sidewall of the cabinet 50. The third part 91 is in communication with the cavity 61, and the fourth part 95 makes the freezing chamber 51 and the third part 91 in communication. The third part 91 and the fourth part 95 are connected to each other when the door 52a is closed, and there is a gasket 90a at a connection part of the third part 91 and the fourth part 95. In the meantime, referring to FIG. 10, the first duct 70 may be applied to the refrigerators in accordance with first to fourth preferred embodiments of the present invention described with reference to FIGS. 6 and 9, respectively. Moreover, the third duct 90 described with reference to FIG. 10 can be applied to the refrigerators in accordance with third and fourth preferred embodiments of the present invention described with reference to FIGS. 8 and 9 respectively. Thus, the refrigerator of the present invention can be embodied in a variety of embodiments. As has been described, the refrigerator of the present invention has the following advantages. First, the dispenser at a height of user's waist or breast provides convenience of use. Second, it is convenient as ice or water is available without opening a door. Third, both an icemaker and an ice container are provided to a door. Therefore, spaces of the freezing chamber and the refrigerating chamber can be used, effectively. Fourth, the cold air formed in the freezing chamber is introduced into the refrigerating chamber through the icemaker. Therefore, direct introduction of the cold air into the refrigerating chamber, and consequential local overcooling of the refrigerating chamber can be prevented. Fifth, since the cold air supplied to the icemaker is supplied to the refrigerating chamber and the freezing chamber, the refrigerator has a high energy efficiency. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to refrigerators, and more particularly, to a refrigerator with an icemaker of an improved structure, which can dispense ice pieces from a dispenser provided to a refrigerator door. 2. Background of Related Art The refrigerator is used for long time fresh storage of food. The refrigerator has food storage chambers each of which temperature is maintained in a low temperature state by a refrigerating cycle, for fresh storage of the food. There are a plurality of storage chambers of different characteristics, so that the user can select storage methods suitable for storage of various kinds of food, taking kinds and characteristics of food and required storage time periods into account. Of the storage chambers, the refrigerating chamber and the freezing chamber are typical. The refrigerating chamber is maintained at about 3° C.˜4° C. for long time fresh storage of food and vegetable, and the freezing chamber is maintained at a subzero temperature for long time storage of meat and fish in a frozen state, and making and storage of ice pieces. In general, the refrigerating chamber has a volume greater than the freezing chamber, and the freezing chamber is allocated over the refrigerating chamber. In the meantime, recently, other than the foregoing traditional functions of the refrigerator, the refrigerator has been developed to have a variety of additional functions. For an example, for drinking cold water in the refrigerating chamber, in the related art, the user is required to open the door, and take out a water bottle from the refrigerating chamber. However, recently, a refrigerator provided with a water dispenser to an outside of a refrigerator door is developed, for dispensing cold water cooled down by cold air in the refrigerating chamber, enabling the user supplied with, and drink the cold water at outside of the refrigerator without opening the door. Moreover, refrigerators each having a water purifying function added to the water dispenser are spread. In general, the water dispenser is provided to a door on the refrigerating chamber for easy supplied of water from the refrigerating chamber to an outside of the refrigerator. However, since the refrigerating chamber is allocated under the freezing chamber, the water dispenser can not, but be provided at a relatively low position. According to this, for using the water dispenser, the user is required to bend forward. In the meantime, when the user drinks water, and when the user cooks food, the user uses ice, frequently. For using ice thus, it is required to open the door on the freezing chamber, and separate ice from an ice tray. Moreover, the opening of the door on the freezing chamber for using the ice causes escaping to cold air from the freezing chamber to an outside of the refrigerator, resulting in temperature rise of the freezing chamber, to required more work of the compressor that consumes an energy. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, the present invention is directed to a refrigerator with an icemaker that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. An object of the present invention is to provide a refrigerator with an icemaker of an improved structure, in which a dispenser is provided at a height convenient for a user. Another object of the present invention is to provide a refrigerator with an icemaker of an improved structure, which can dispense ice to a user at an outside of the refrigerator without opening a door. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these objects and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, the refrigerator with an icemaker includes a cabinet, a case, a first duct, the icemaker, an ice container, and a dispenser. The cabinet includes a mullion wall for compartmentalization of a freezing chamber and a refrigerating chamber. The case is provided to a door on the refrigerating chamber, and has a cavity therein. It is preferable that the case is formed of a thermal insulating material. The first duct provided to pass through the mullion wall for supplying cold air from a neighborhood of an evaporator in the freezing chamber to the cavity. The icemaker is provided in the cavity, and produces ice, and the ice container is provided in the cavity, and stores the ice. The dispenser is provided in the door so as to be in communication with the cavity. The first duct includes a firs part in the door in communication with the cavity, and a second part in the freezing chamber passed through the mullion wall, the second part being in communication with the first part when the door is closed. The first duct further includes a gasket at a connection part of the first and the second parts when the door is closed. The first duct includes a first part in the door in communication with the cavity, and a second part in contact with the mullion wall, and in communication with the first part passed through the mullion wall. The first duct includes a first part provided to the door, and a second part provided to a sidewall of the cabinet so as to be in communication with the first part. The refrigerator may further include a first fan adjacent to the evaporator for supplying cold air to the first duct, and a second fan in a bent part of the first duct for turning a flow direction of the cold air. The case may further include a hole in communication with the refrigerating chamber. The case may further include a damper on the hole. The second duct has one end arranged adjacent to the evaporator, and the other end arranged in the refrigerating chamber, for supplying the cold air to the refrigerating chamber. The second duct includes a plurality of through holes in an outside circumferential surface for supplying cold air to the refrigerating chamber. The second duct includes a louver provided to each of the through holes for guiding a discharge direction of the cold air. The refrigerator further includes a damper adjacent to the evaporator for controlling a flow rate of the cold air supplied to the second duct. In other aspect of the present invention, there is provided a refrigerator with an icemaker including the cabinet, the case, the first duct, a third duct, the icemaker, the ice container, and the dispenser. The third duct has one end in communication with the cavity, and the other end in commmunication with the freezing chamber, for supplying the cold air from the cavity to the freezing chamber. The third duct may include a third part provided to the door so as to be in communication with the cavity, and a fourth part in communication with the freezing chamber passed through the mullion wall, and fitted so as to be in communication with the third part when the door is closed. The third duct may further include a gasket provided to a part where the third part and the fourth part are connected when the door is closed. The third duct may include a third part provided to the door so as to be in communication with the cavity, and a fourth part provided to the sidewall of the cabinet, and fitted so as to be in communication with the third part when the door is closed. In another aspect of the present invention, there is provided a refrigerator with an icemaker including the cabinet, the case, the first duct, the second duct, the third duct, the icemaker, the ice container, and the dispenser. It is to be understood that both the foregoing description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention claimed. | 20040203 | 20060718 | 20050324 | 58292.0 | 1 | TAPOLCAI, WILLIAM E | REFRIGERATOR WITH ICEMAKER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,769,838 | ACCEPTED | Flat panel display having integral heater, EMI shield, and thermal sensors | A flat panel display having a black mask EMI layer isolated from Vcom and tied to zero potential. The flat panel display has an integral metal heater layer and thermal sensor that are in close proximity to the liquid crystals to provide efficient heating and temperature sensing. | 1. A flat panel display comprising: a front glass plate; a rear glass plate; a layer of liquid crystals interposed between said front and rear glass plates; a TFT array layer interposed between said front and rear glass plates; and at least one thermal sensor integral to said TFT array layer. 2. A flat panel display according to claim 1, wherein said thermal sensor is applied onto said TFT array layer. 3. A flat panel display according to claim 1, wherein said at least one thermal sensor is comprised of an array of diodes. 4. A flat panel display according to claim 1, wherein said at least one thermal sensor is interposed between said front and rear glass plates to provide timely temperature sensing of said layer of liquid crystals. 5. A flat panel display according to claim 1, further comprising: an EMI layer interposed between said front and rear glass plates. 6. A flat panel display according to claim 5, wherein said at least one thermal sensor lies under said EMI layer. 7. A flat panel display according to claim 5, wherein said EMI layer is a black mask EMI layer. 8. A flat panel display according to claim 1, wherein said thermal sensor is comprised of diode array that provides a nominal 2.5 volt to 5.0 volt change in bias potential as the liquid crystal temperature changes from −60 degrees Celsius to 100 degrees Celsius. 9. A flat panel display comprising: a front plate; a rear plate; a layer of liquid crystals interposed between said front and rear plates; a TFT array layer interposed between said front and rear plates; and at least one thermal sensor integral to said TFT array layer. 10. A flat panel display according to claim 9, wherein said thermal sensor is applied onto said TFT array layer. 11. A flat panel display according to claim 9, wherein said at least one thermal sensor is comprised of an array of diodes. 12. A flat panel display according to claim 9, wherein said at least one thermal sensor is interposed between said front and rear plates to provide timely temperature sensing of said layer of liquid crystals. 13. A flat panel display comprising: a front plate; a rear plate; a layer of liquid crystals interposed between said front and rear plates; and at least one thermal sensor interposed between said front and rear plates to provide temperature sensing of said layer of liquid crystals. 14. A flat panel display according to claim 13, wherein said at least one thermal sensor is comprised of an array of diodes. 15. A flat panel display according to claim 13, further comprising: a TFT array layer interposed between said front and rear plates, wherein said at least one thermal sensor is integral to said TFT array layer. 16. A flat panel display according to claim 15, wherein said at least one thermal sensor is applied onto said TFT array layer. | This application is a continuation-in-part of pending U.S. application Ser. No. 10/679,977, filed on Oct. 7, 2003. BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to a liquid crystal flat panel display. More particularly, in one embodiment, the flat panel display of the present invention has layers of Indium Tin Oxide (ITO), or other optically transparent electrically conductive materials, coated on the front and rear external glass surfaces under the front and rear polarizers. The ITO layer at the front of the display acts as an electromagnetic interference (EMI) filter or shield. The ITO layer at the back of the display is used as a heater. Each ITO layer may or may not be overcoated on one or both sides with index matching dielectrics to improve optical transmission through the ITO coatings, and/or reduce the optical reflections at the front and/or rear surfaces of the ITO layers. In an alternative embodiment, the ITO heater layer is placed on the inside surface of the rear glass plate allowing the ITO heater layer to be closer to the liquid crystal layer. This reduces the thermal resistance between the ITO layer and the liquid crystal layer thus reducing the amount of power necessary to heat the liquid crystal layer. In the preferred embodiment, bus bars are placed along predetermined edges of the ITO heater layer. The bus bars allow for the uniform injection of current into the ITO heater layer. It is also preferred that thermal sensors be placed on the inside portion of the glass and in close proximity to the ITO layer to detect the heat being inputted into the liquid crystal layer. In another alternative embodiment, an integral metal heater is used instead of the ITO heater layer. The metal heater is applied to the TFT layer and is in close proximity to the liquid crystal layer to provide improved and efficient heating capabilities. In another alternate embodiment, a black mask EMI layer is interposed between the front and back glass plates. In the preferred embodiment, the EMI layer is isolated from Vcom and tied to zero potential. It is preferred that the integral metal heater be placed behind the black mask EMI layer so that no portion of the heater is visible and no portion of the heater interferes with the pixel apertures. In another alternate embodiment, integral thermal sensors may also be layered onto the TFT array layer preferably under the black mask EMI layer. In this embodiment, thermal resistivity between the integral heater and the thermal sensor(s) is reduced leading to faster thermal sensor response times. It is appreciated, as discussed in further detail below, that features of the alternate embodiments discussed above may be combined to form additional alternative flat panel display designs. For example, a flat panel display may be configured with all of the inventions of the isolated black mask EMI layer, integral thermal sensor and integral heater combined in one flat panel display. In addition to the features mentioned above, objects and advantages of the present invention will be readily apparent upon a reading of the following description. BRIEF DESCRIPTION OF THE DRAWINGS Novel features and advantages of the present invention, in addition to those mentioned above, will become apparent to those skilled in the art from a reading of the following detailed description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts and in which: FIG. 1 illustrates a known flat panel display system; FIG. 2 illustrates one embodiment of the flat panel display of the present invention; FIG. 3 illustrates an alternative embodiment of the flat panel display of the present invention; FIG. 4 illustrates an alternative embodiment of the flat panel display of the present invention; FIG. 5 illustrates a plan view of one example of a flat panel display of the present invention showing flexible TCP connections; FIG. 6 illustrates a perspective blow-up view of one embodiment of a display incorporating the flat panel display of the present invention; FIG. 7 illustrates a plan view of one embodiment of the black mask EMI shield layer of the present invention; FIG. 8 illustrates a plan view of one embodiment of a metal heater layer of the present invention; FIG. 9 illustrates one example embodiment of a heater circuit of the present invention; FIGS. 10A-B illustrate other integral heater designs; FIG. 11 illustrates one embodiment of a TFT design of the present invention with integral heater; FIG. 12 illustrates one embodiment of a thermal sensor diode array of the present invention; FIG. 13 illustrates a plan view of a flat panel display showing thermal sensor placement; FIG. 14 illustrates an example block diagram of the electrical components and connections of a display incorporating the flat panel display of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S) The preferred system herein described is not intended to be exhaustive or to limit the invention to the precise forms disclosed. They are chosen and described to explain the principles of the invention, and the application of the method to practical uses, so that others skilled in the art may practice the invention. FIG. 1 illustrates a known display system. In known flat panel displays, the polarizer layers are placed directly on the front and back plates. FIG. 2 illustrates one embodiment of the flat panel display 10 of the present invention. According to known flat panel display technology, the display is comprised of a front plate 12 and a back plate 14. In one embodiment of the present invention, layers of Indium Tin Oxide (ITO) layers 18, 20 (with or without additional index of refraction matching dielectric layers) are placed between the outside surfaces of the front and back plates and the polarizer layers 16. In one embodiment, the front plate is a liquid crystal display (LCD) color filter (CF) plate and the back plate is an LCD thin film transistor (TFT) plate. In one embodiment the front and back plates are transparent glass substrates. According to known principles, a layer of liquid crystals are placed between the plates. In the embodiment of FIG. 2, the front EMI shield ITO coating 18 is preferably a constant ≦15-20 ohms/sq value. A first index matching dielectric layer 22 may be placed between the EMI shield ITO layer and the front polarizer layer. A second index matching dielectric layer 24 may be placed between the EMI shield ITO layer and the front plate. When electrically bonded or grounded to the associated metal or electrically conductive chassis of the complete LCD assembly and/or its associated product chassis, this front ITO coating acts as an EMI shield. This ITO EMI shield significantly reduces radiated emissions originating from the LCD itself, as well as shields, or reduces the susceptibility of, the LCD from the effects of externally imposed electromagnetic fields. In the embodiment of FIG. 2, the rear heater ITO coating 20 is preferably sandwiched between a first index matching dielectric layer 26 and a second index matching dielectric layer 28. The first index matching dielectric layer 26 may be placed between the heater ITO layer and the rear polarizer layer. The second index matching dielectric layer 28 may be placed between the heater ITO layer and the back plate. The index matching layers are for matching the index of refraction between the heater ITO layer and the glass and between the heater ITO layer and the Pressure Sensitive Adhesive (PSA) layers 40, 42 of the polarizer, respectively. Index matching helps keep the specular reflection to an absolute minimum, which also increases the optical transmission of the entire optical stack. The rear ITO layer is actively driven by circuitry to function as a heater. The ohm/sq value of this ITO layer may vary as desired based on performance needs and size variables. In the preferred embodiment of FIG. 2, the outer edges 30 of the front ITO layer and the front plate extend past (e.g., 0.25-0.50 mm) the outer edges 32 of the front polarizer and first dielectric layer (if present) 18. This exposes the front ITO layer for electrical contact outboard of the polarizer edges. Similarly, two opposed outer edges 34 of the back ITO layer and the back plate extend past the outer edges 36 of the back polarizer layer and the dielectric layer (if present) 20. Thus the ITO layer is exposed for connection of the drive circuitry for the heater function. Placing the ITO layers and the index matching layers between the polarizers and the LCD plates provides advantages over known flat panel displays (i.e., current known processes apply the coatings on separate glass plates (not directly on the LCD plates). The separate front EMI plate can be mounted free standing in front of the LCD or laminated with optical adhesive directly to the front polarizer of the LCD. The separate rear heater plate is laminated with optical adhesive directly to either the front or rear polarizer of the LCD in order to facilitate adequate heat transfer from the ITO heating layer to the liquid crystal fluid. In some known configurations, the heater ITO is decoupled (radio frequency (RF)) to the chassis ground of the LCD, so that it functions as both the EMI shield and the heater. In these cases, the heater element is typically laminated to the front polarizer of the LCD. Placing the ITO layers, with or without index matching layers, directly on the plates results in significant cost, weight, and thickness savings, as well as improved optical performance. The process embodied in this invention also provides a more efficient coupling of the heater ITO to LCD fluid, reducing the power density required to heat the LCD fluid to a given temperature over a given period of time. This improved coupling results from having the ITO heater coated directly on the surface of the LCD glass, thereby eliminating the thermal resistance caused in known implementations by the optical adhesive, polarizer and polarizer PSA. In typical known configurations, a power density of 2 watts per square inch of display image area is required to heat the LCD fluid from −54° C. to −20° C. in ≦10 minutes. With the ITO coated directly on the rear surface of the LCD, this same heating of the LCD fluid can be accomplished with a power density of 1.8 watts per square inch of display image area. In known flat panel display systems, where ITO layers are coated on separate glass plates that are then laminated to the outside of the polarizer, the lamination process often results in layers that contain bubbles or particulates. Displays having bubble or particulate contamination are scrapped as unsatisfactory displays. Because the contamination is not detectable until the adhesive is dry and the display is fully assembled, a contaminated laminate layer results in the loss of an entire LCD assembly. Coating the ITO, with or without index matching layers, directly on the external front and rear surfaces of the LCD glass (i.e., plates) avoids this high yield loss. Placing the index matching ITO layers directly on the plates also prevents the undesirable effects of lamination-induced window framing (LIWF). In known flat panel displays, the ITO layers are coated directly onto separate glass plates, which are typically then laminated permanently with optical adhesive to the external surfaces of the front and/or rear polarizer(s). Due to the shrinkage of the optical adhesive during its cure, and/or differential coefficients of thermal expansion (Cte) of the ITO cover glass(es), optical adhesive, polarizer and LCD glass, the LCD glass bends or bows, changing the cell gap between the front and rear glass plates of the LCD. This cell gap deformation locally changes the image contrast, typically causing “whitening” or “darkening” degradation of contrast around the edge or periphery of the display area (i.e., “halo” effect). This effect is known as LIWF. The severity of this degradation changes with the age and operating temperature of the display. By skipping the step of laminating ITO coated glass plates to the outside surface of the polarizer layer, LIWF is avoided. Placing the index matching ITO layers directly on the plates also enhances optical performance. The present invention has a reduced specular reflection and increased contrast over known displays which have ITO coated glass plates laminated to the outside surface of the polarizers. By placing the front ITO layer under the front polarizer layer, less light is reflected from the display. In other words, because the front polarizer is transmitting only a portion of the light from the outside (e.g., 42% of the light is transmitted by the polarizer), a corresponding smaller amount of that transmitted light is reflected by the ITO layer between the polarizer and the front plate. The ITO layers and the index matching dielectric layers of the present invention are applied using known manufacturing processes such as sputtering or vapor deposition. FIG. 3 illustrates another embodiment of a flat panel display 50 of the present invention. In this embodiment, the display is preferably comprised of the following layers: a front polarizer 52, a pressure sensitive adhesive layer 54, an LCD color plate or glass layer 56, a black mask layer 58 (preferably chrome), a color filter layer 60, a Vcom ITO 62, a first and second Polyamide Alignment Layer 64, a layer of liquid crystals 65, a TFT array layer 66, and insulator layer 68, an ITO heater layer 70, a LCD TFT plate or glass 72, a second pressure sensitive adhesive layer 74, a rear polarizer layer 76, and anti-reflective coating layers 78. In the embodiment of FIG. 3, the ITO heater layer is preferably placed on the inside surface of the glass plate allowing the ITO heater layer to be closer to the liquid crystal layer. This reduces the thermal resistance between the ITO layer and the liquid crystal layer thus reducing the amount of power necessary to heat the liquid crystal layer. Furthermore, since there are fewer intervening layers between the ITO heater and the liquid crystal layer, less power is needed to heat the liquid crystal layer. Because of the lower power requirements for powering the ITO layer, the ohms/square and therefore thickness or density of the ITO may be reduced, thereby increasing the optical transmission. In the preferred embodiment of FIG. 3, bus bars are placed along predetermined edges of the ITO heater layer. The bus bars provide a low impedance connection along predetermined edges of the ITO heater layer. The bus bars allow for the uniform injection of current into the ITO heater layer. In one embodiment, silk screen epoxy is laid onto the ITO heater layer which is then placed in an oven and heated. Accordingly, the resulting bus bars become embedded into the ITO layer. In this embodiment, it is preferred that the black mask layer, preferably comprised of chrome, be electrically tied to the zero potential chassis. Accordingly, the black mask layer acts as an EMI layer. In an alternate embodiment, index matching dielectric layers can be sandwiched around the ITO heater layer to provide the benefits discussed earlier. The insulator layer could also be used as an index matching dielectric layer. In one embodiment, the black mask layer is applied through known vapor deposition or sputtering techniques. FIG. 4 illustrates another alternative embodiment of the flat panel glass and display illustrated in FIG. 3. FIG. 4 is the preferred embodiment of the flat panel display of the present invention. In the preferred embodiment, the LCD is a TFT active matrix liquid crystal display (AMLCD) with source and gate drive flexible tape carrier package (TCP) connections 84. In the embodiment of FIG. 4, the heater layer 80 and thermal sensors (shown generally at 82) are integral to the flat panel display as they are applied to the TFT array structure. The flat panel display of FIG. 4 avoids the high yield loss and LIWF issues of the prior art displays as previously discussed. In the embodiment of FIG. 4, the LCD is comprised of a black mask EMI shield interposed between the front and rear glass plates. LCDs radiate EMI (radiated emissions) and are also susceptible to high strength EMI fields (radiated susceptibility). To guard against these EMI problems in sensitive environments (i.e., military applications, aircraft applications, etc.), an optically transmissive, low electrical resistance layer is used to cover the entire active area of the displayed image. Historical solutions have involved optically laminating or bonding a cover glass to the front of the LCD that has either been coated with an 8-20 ohm/square Indium Tin Oxide (ITO) layer or contains a low resistance black oxide wire mesh. The EMI shield absorbs and conducts the interference signal from the display. Using a cover glass is costly and electrical termination is labor intensive due to the use of electrically conductive bus bars and associated wire/foil leads. The use of cover glasses also creates optical problems because the ITO or wire mesh—reduces optical transmission and increases ambient light reflections that both contribute to reduced image luminance and contrast. To compensate for the reduced luminance and contrast, higher intensity backlights are used which leads to greater system costs, higher display operating temperature (reduced life) and greater system power consumption (more increased system costs). Furthermore, with wire mesh, image moiré (i.e., optically distracting black and white moving pattern caused by optical interference between the mesh and pixel structures) can never be eliminated. In the preferred embodiment of the black mask EMI shield, the gate, source, heater bus lines, pixel capacitors, and pixel feed-throughs are covered by the low reflection, electrically conductive (e.g., less than or equal to 10.0 ohms/square) black mask when viewed from any angle, preferably over the entire viewing area. Electrical connection to the black mask is preferably accomplished through the source TCPs and through a flex printed circuit (FPC) across the display. The black mask is preferably applied with the known process of sputtering or evaporating (i.e., vacuum deposition). The layers are preferably applied to reduce the ohms/square resistance from approximately 20-30 ohms/square to 8-10 ohms/square. Accordingly, in the preferred embodiment, the black mask is the very first layer deposited and adhered to the inside of the front plate (i.e., color plate) of the LCD. Vcom, on most LCD panels, is some positive voltage around 4-7 volts. By isolating the black mask from Vcom, the Vcom electrical potential (and normal functions of the LCD) is left undisturbed. By connecting the black mask to chassis ground, a low DC and RF (radio frequency) resistance/impedance Faraday cage or EMI shield is established between the “outside” world and the TFT transistors of the LCD. Therefore, the isolated and chassis grounded black mask forms an EMI shield between the active electronics of the LCD and the outside world. This reduces the radiated emissions from the LCD panel, as well as increases the resistance of the LCD panel to radiated susceptibility (i.e., image degradation caused by the influence of external electrical fields), without having to add some external feature (i.e., a laminated ITO coated piece of cover glass). In addition, since the black mask does not cover or obscure the active pixel aperture, the integral EMI shield does not reduce any light transmission through the LCD (i.e., an externally laminated ITO coated piece of glass has less than 100% optical transmission and thereby reduces light transmission thought the LCD). Also, an externally laminated ITO piece of cover glass has a specular and diffuse reflection of >0.0%, thereby increasing the reflectivity of the LCD, which reduces image contrast (particularly when combined with the reduced light transmission of the laminated cover glass). None of these optical degradations occur with our integral EMI shield (i.e., no increase in specular and diffuse reflectance, no reduction in LCD optical transmission, and no reduction in image contrast). The black mask (BM) EMI shield of the present invention uses an existing structure within the LCD to perform an additional function. Other than the very low cost addition of an optically clear resin dielectric (insulating) layer 83 between the black mask and the Vcom ITO (already existing structures within the LCD) there are no items added to degrade the image quality. FIG. 5 illustrates one example embodiment of a flat panel display having flexible TCP connections. Connections to the internal EMI shield are accomplished through the TCP. In this example embodiment, heater channels: 4-60, 89-145, 174-230, 259-315 (total: 228 channels); black mask channels: 65-84, 150-169, 235-254 (total: 60 channels); dummy channels: 1-3, 61-64, 85-88, 146-149, 170-173, 231-234, 255-258, 316-318 (total: 30 channels) are used. The source and gate drive flexible tape carrier package (TCP) connections are shown at 84. The EMI bonding pads are illustrated at 86. FIG. 6 illustrates a perspective blow-up view of one embodiment of the flat panel display of the present invention illustrating the TCP connections. FIG. 7 illustrates a plan view of one embodiment of the black mask EMI shield layer of the present invention. It is preferred that the black mask resistivity be <10 ohms per square. In one embodiment the black mask is comprised of a CrOx/CrNx/Cr, 350/350/1020A, layer. In the embodiment of FIG. 4, an integral metal heater 80 (shown in black) is used instead of the ITO heater layer. In the preferred embodiment, metal heater is patterned on top of the passivation layer of the thin film transistors (TFTs) and then overcoated with another passivation layer to electrically isolate the metal layer from the pixel capacitors. Because the heater layer is closer to the liquid crystal layer, thermal resistance is reduced between the heater and the liquid crystal layer thus reducing the amount of power necessary to heat the liquid crystal layer. Again, since there are fewer intervening layers between the heater and the liquid crystal layer, less power is needed to heat the liquid crystal layer. FIG. 8 illustrates a plan view of one embodiment of a metal heater layer of the present invention. It is preferred that the integral metal heater be hidden behind the black mask EMI layer so that no portion of the heater is visible and no portion of the heater interferes with the pixel apertures. The LCD liquid crystal (LC) fluid is heated to preserve response time (i.e., prevent image smearing of rapid image movement) at lower display module temperatures (usually somewhere below 0 degrees C.). To accomplish this, historic solutions have involved optically laminating or bonding a cover glass to the front or rear of the LCD that is coated with an Indium Tin Oxide (ITO) layer whose electrical resistance is selected to produce a power dissipation of typically 2 watts/square inch of image area when the heater voltage is applied. This typical method is costly (e.g., the heater glass is expensive) and electrical termination is labor intensive (i.e., required electrically conductive bus bars and associated wire/foil leads). Furthermore, the typical heating technologies are prone to handling damage resulting in unusable LCDs. These historic heater technologies also created optical problems due to reduced optical transmission and increased ambient light reflections. Accordingly, these typical LCDs have reduced image luminance and contrast. The integral metal heater of the present invention is comprised of structure within the LCD to perform the heater function. The integral metal heater is preferably made by two additional photolithography steps, which does increase the cost of the LCD cell, but to only a fraction of the cost of an external heater. The metal heater is preferably optically hidden under the black mask (BM). Therefore, there is no reduction in LCD optical transmission and image luminance, no increase in ambient light reflections, no degradation in image contrast, and no issues with heater electrical termination. Electrical termination is preferably accomplished automatically with known TCP and anisotropic conductive film (ACF) termination. The TCP connection between the LCD and display electronics is advantageous as it provides a flexible connection. Preferably, the heater pattern is comprised of a horizontal and vertical grid of controlled resistance heater conductors, with low resistance horizontal “heater +” bus bar at the top of the vertical grid (e.g., preferably less than or equal to 0.5 ohms) and a low resistance “heater −” bus bar at the bottom of the vertical grid. It is preferred that all portions of the heater grid be outside of the active pixel aperture and hidden from view under the black mask. The exact heater grid pattern is located to minimize capacitive coupling between the heater grid and the gate and source bus lines. In the preferred embodiment, there are heater grid lines under each horizontal and vertical leg of the black mask. Preferably, the heater grid is over-coated with an insulating dielectric having a breakdown potential of over 100 volts DC. Connections to the heater − (i.e., the bottom bus adjacent to the source TCPs) are preferably routed to associated traces on the source TCPs. Heater − is preferably connected, in the source PCB, to ground potential. Connections to the heater + (i.e., top bus bar or the bar on the edge opposite the source TCPs) are preferably routed to pads on the exposed areas of the front side of the rear glass (i.e., TFT plate) for ACF connection to the heater and black mask EMI FPC. During heater operation, heater + is preferably connected to 28 VDC through the heater and black mask EMI FPC. When the heater is not operating, the heater + connection is preferably connected to heater − and ground. In the preferred embodiment, all features of the patterned heater, including the heater + and heater − bars are covered by the black mask in the assembled LCD cell so that no heater pattern or heater bus bar features are visible in the display image. FIG. 9 illustrates one example embodiment of a heater circuit of the present invention. FIGS. 10A-B illustrate other integral heater designs. FIG. 10A illustrates a vertical parallel heater design. In this embodiment, the heater conductors preferably lie directly under source bus lines. The heater lines are preferably narrower than the bus lines and do not intrude into the sub-pixel apertures. This minimizes capacitive coupling to the pixel capacitor and eliminates reduction in panel transmission by the heater. FIG. 10B illustrates one example grid design having 525 horizontal and 525 vertical lines. In this embodiment, the heater conductors preferably lie directly under source and gate bus lines and are narrower than the bus lines and do not intrude into the sub-pixel apertures. In alternate embodiments, the number of horizontal and vertical heater lines may vary. For example, the heater grid pattern may be 525 horizontal and 1,573 vertical lines; 525 horizontal and 787 vertical lines; or 768 half-width horizontal lines and 1,536 vertical lines. In an alternate embodiment, the heater grid patterns may be varied to provide a greater heater grid density around the periphery of the display. The heater grid density would decrease moving towards the center of the display. Placing a higher density grid pattern around the periphery allows for the application of more heat around the edges of the display to account for the higher thermal mass due to the bezel attachment around the periphery of the display. In other words, due to the bezel attachment, more heat is required around the periphery of the display to achieve the same degree of display heating. Accordingly, the thermal rise of the display is substantially consistent for the edges and center of the display. As discussed, the integral metal heater of the present invention is applied by known bus metallization techniques. FIG. 11 illustrates one embodiment of a TFT design of the present invention with integral heater. As shown in the embodiment illustrated in FIG. 4, it is also preferred that thermal sensors 82 be placed on the inside portion of the glass plates. Preferably, the sensors are in close proximity to the heater layer to detect the heat being inputted into the liquid crystal layer so as to provide timely feedback to the system. The integral thermal sensors are also applied onto the TFT array layer preferably under the black mask EMI layer. In this embodiment, thermal resistivity is reduced leading to faster thermal sensor and heater control response times. The integral thermal sensor of the present invention provides an efficient, low cost solution as there are no separate thermal sensor components that must be purchased. Furthermore, there is no process time or labor required to attach a thermal sensor to the LCD or to attach thermal sensor wires to a circuit. With the integral thermal sensor, signal attachment automatically occurs with ACF attachment of the TCP attachment. The intimate contact between sensor and LCD fluid provides higher accuracy and reduced time lag between actual fluid temperature and thermal sensor readings. In the preferred embodiment, a series/parallel array of diodes is embedded within the TFT array to sense the temperature of the LC fluid. FIG. 12 illustrates one embodiment of a diode array 88 of the present invention. In this embodiment, the thermal sensors are comprised of a diode array (e.g., 3 in series, 10 parallel) built into the TFT array layer. The anodes of the top array are preferably connected to a common node and brought out of the source TCP as “Thermal Sensor +”. The cathodes at the bottom of the diode array are preferably connected to common node and brought out of the source TCP as “Thermal Sensor −”. The number of diodes in each array may vary, however in the preferred embodiment, the number of diodes shall be selected to provide a nominal 2.5V to 5.0V change in the diode string forward bias potential as the LC fluid changes from −60 degrees C. to +100 degrees C. In the preferred embodiment, a thermal sensor diode array according to the present invention is located and electrically connected between each source TCP. For example, if there are four TCPs there will be three thermal sensor diode arrays. FIG. 13 illustrates a plan view of a flat panel display showing thermal sensor placement. FIG. 14 illustrates an example block diagram of the electrical components and connections of a display incorporating the flat panel display of the present invention. Having shown and described a preferred embodiment of the invention, those skilled in the art will realize that many variations and modifications may be made to affect the described invention and still be within the scope of the claimed invention. Thus, many of the elements indicated above may be altered or replaced by different elements which will provide the same result and fall within the spirit of the claimed invention. It is the intention, therefore, to limit the invention only as indicated by the scope of the claims. | <SOH> BACKGROUND AND SUMMARY OF THE INVENTION <EOH>The present invention relates to a liquid crystal flat panel display. More particularly, in one embodiment, the flat panel display of the present invention has layers of Indium Tin Oxide (ITO), or other optically transparent electrically conductive materials, coated on the front and rear external glass surfaces under the front and rear polarizers. The ITO layer at the front of the display acts as an electromagnetic interference (EMI) filter or shield. The ITO layer at the back of the display is used as a heater. Each ITO layer may or may not be overcoated on one or both sides with index matching dielectrics to improve optical transmission through the ITO coatings, and/or reduce the optical reflections at the front and/or rear surfaces of the ITO layers. In an alternative embodiment, the ITO heater layer is placed on the inside surface of the rear glass plate allowing the ITO heater layer to be closer to the liquid crystal layer. This reduces the thermal resistance between the ITO layer and the liquid crystal layer thus reducing the amount of power necessary to heat the liquid crystal layer. In the preferred embodiment, bus bars are placed along predetermined edges of the ITO heater layer. The bus bars allow for the uniform injection of current into the ITO heater layer. It is also preferred that thermal sensors be placed on the inside portion of the glass and in close proximity to the ITO layer to detect the heat being inputted into the liquid crystal layer. In another alternative embodiment, an integral metal heater is used instead of the ITO heater layer. The metal heater is applied to the TFT layer and is in close proximity to the liquid crystal layer to provide improved and efficient heating capabilities. In another alternate embodiment, a black mask EMI layer is interposed between the front and back glass plates. In the preferred embodiment, the EMI layer is isolated from Vcom and tied to zero potential. It is preferred that the integral metal heater be placed behind the black mask EMI layer so that no portion of the heater is visible and no portion of the heater interferes with the pixel apertures. In another alternate embodiment, integral thermal sensors may also be layered onto the TFT array layer preferably under the black mask EMI layer. In this embodiment, thermal resistivity between the integral heater and the thermal sensor(s) is reduced leading to faster thermal sensor response times. It is appreciated, as discussed in further detail below, that features of the alternate embodiments discussed above may be combined to form additional alternative flat panel display designs. For example, a flat panel display may be configured with all of the inventions of the isolated black mask EMI layer, integral thermal sensor and integral heater combined in one flat panel display. In addition to the features mentioned above, objects and advantages of the present invention will be readily apparent upon a reading of the following description. | <SOH> BACKGROUND AND SUMMARY OF THE INVENTION <EOH>The present invention relates to a liquid crystal flat panel display. More particularly, in one embodiment, the flat panel display of the present invention has layers of Indium Tin Oxide (ITO), or other optically transparent electrically conductive materials, coated on the front and rear external glass surfaces under the front and rear polarizers. The ITO layer at the front of the display acts as an electromagnetic interference (EMI) filter or shield. The ITO layer at the back of the display is used as a heater. Each ITO layer may or may not be overcoated on one or both sides with index matching dielectrics to improve optical transmission through the ITO coatings, and/or reduce the optical reflections at the front and/or rear surfaces of the ITO layers. In an alternative embodiment, the ITO heater layer is placed on the inside surface of the rear glass plate allowing the ITO heater layer to be closer to the liquid crystal layer. This reduces the thermal resistance between the ITO layer and the liquid crystal layer thus reducing the amount of power necessary to heat the liquid crystal layer. In the preferred embodiment, bus bars are placed along predetermined edges of the ITO heater layer. The bus bars allow for the uniform injection of current into the ITO heater layer. It is also preferred that thermal sensors be placed on the inside portion of the glass and in close proximity to the ITO layer to detect the heat being inputted into the liquid crystal layer. In another alternative embodiment, an integral metal heater is used instead of the ITO heater layer. The metal heater is applied to the TFT layer and is in close proximity to the liquid crystal layer to provide improved and efficient heating capabilities. In another alternate embodiment, a black mask EMI layer is interposed between the front and back glass plates. In the preferred embodiment, the EMI layer is isolated from Vcom and tied to zero potential. It is preferred that the integral metal heater be placed behind the black mask EMI layer so that no portion of the heater is visible and no portion of the heater interferes with the pixel apertures. In another alternate embodiment, integral thermal sensors may also be layered onto the TFT array layer preferably under the black mask EMI layer. In this embodiment, thermal resistivity between the integral heater and the thermal sensor(s) is reduced leading to faster thermal sensor response times. It is appreciated, as discussed in further detail below, that features of the alternate embodiments discussed above may be combined to form additional alternative flat panel display designs. For example, a flat panel display may be configured with all of the inventions of the isolated black mask EMI layer, integral thermal sensor and integral heater combined in one flat panel display. In addition to the features mentioned above, objects and advantages of the present invention will be readily apparent upon a reading of the following description. | 20040202 | 20071106 | 20050407 | 98141.0 | 1 | DUDEK, JAMES A | FLAT PANEL DISPLAY HAVING INTEGRAL HEATER, EMI SHIELD, AND THERMAL SENSORS | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,770,024 | ACCEPTED | Apparatus for controlling throttle shaft deflection and friction in dual bore throttle bodies | An air intake control device is provided, including a housing, a plurality of bores, a passageway, and a support surface. The housing defines the bores, the passageway, and the support surface. A shaft is rotatably received within the passageway, and a plurality of plates are connected to the shaft. The bores accept fluid with a varying flow rate based on the rotation of the shaft and plates. A bushing is located between the support surface and the shaft and it prevents contact between the shaft and the housing. The bushing may selectively engage the shaft based on the flow rate through the bores. Additionally, the bushing may also have a slit and a variable diameter. The air intake control device may include a bearing assembly, which includes a rotating element which contacts the shaft, and a support element which positions the rotating element with respect to the shaft. The air intake control device may also include a plurality of bearings to rotatably receive the shaft and a spacer coupled with the bearings to form a substantially air-tight seal. | 1. A throttle body for an automobile, comprising: a housing defining a plurality of bores separated by a central wall, a passageway defined through the central wall; a shaft rotatably received within the passageway; a plurality of plates coupled with the shaft; and a contact preventing means configured to selectively engage the shaft upon deflection of the shaft in the region of the central wall, and to prevent contact between the shaft and the housing. 2. A throttle body for an automobile, comprising: a housing defining a plurality of bores separated by a central wall, a passageway defined through the central wall; a shaft rotatably received within the passageway; a plurality of plates coupled with the shaft; and a bushing located in the passageway between the central wall and the shaft and configured to selectively engage the shaft upon deflection of the shaft in the region of the central wall, and to prevent contact between the shaft and the housing; the passageway including a plurality of openings, the openings including at least a first opening with a first diameter and a second opening with a second diameter, wherein the first diameter is not substantially equal to the second diameter. 3. A throttle body as in claim 2, wherein the central wall includes a first section in contact with the bushing and a second section adjacent to the first section and not in contact with the bushing, wherein a first distance between an edge of the shaft and the first section measured perpendicular to the shaft is greater than a second distance between the edge of the shaft and the second section measured perpendicular to the shaft. 4. A throttle body as in claim 2, further including: a plurality of bearing structures coupled with the housing and configured to rotatably receive the shaft; and a spacer coupled with the shaft; the spacer and at least one of the bearing structures configured to cooperatively form a seal. 5. A throttle body for an automobile, comprising: a housing defining a plurality of bores separated by a central wall, a passageway defined through the central wall; a shaft rotatably received within the passageway and configured to rotate around a shaft axis; a plurality of plates coupled with the shaft; and a spring bushing having a cross-sectional diameter, the spring bushing configured to connect with the central wall via a spring force urging the cross-sectional diameter to expand, the spring bushing configured to engage the shaft and to prevent contact between the shaft and the housing. 6. A throttle body as in claim 5, the spring bushing including a slit configured to permit the cross-sectional diameter to expand. 7. A throttle body as in claim 6, wherein the slit is not substantially parallel with the shaft axis. 8. A throttle body as in claim 7, wherein the slit and the shaft axis form an angle of between 15 degrees and 45 degrees. 9. A throttle body as in claim 7, wherein the slit and the shaft axis form an angle of between 25 degrees and 35 degrees. 10. A throttle body as in claim 7, the spring bushing having a generally circular cross-section. 11. A throttle body as in claim 5, wherein the spring bushing selectively engages the shaft based on the deflection of the shaft in the region of the central wall. 12. A throttle body for an automobile, comprising: a housing defining a plurality of bores separated by a central wall, a passageway defined through the central wall; a shaft rotatably received within the passageway; a plurality of plates coupled with the shaft; and a bearing assembly located in the passageway between the central wall and the shaft and configured to contact the shaft, to rotate with respect to the housing, and to prevent contact between the shaft and the housing. 13. A throttle body as in claim 12, wherein the bearing assembly includes a rotating element configured to rotate at a bearing rotation speed, wherein the shaft rotates at a shaft rotation speed, and wherein the bearing rotation speed depends on the shaft rotation speed. 14. A throttle body as in claim 13, wherein the bearing rotation speed and the shaft rotation speed are substantially equal when the bearing assembly is in contact with the shaft. 15. A throttle body as in claim 12, wherein the bearing assembly includes a rotating element and a support element, the support element configured to rotatably receive the rotating element. 16. A throttle body as in claim 15, wherein the rotating element has a substantially circular cross-section. 17. A throttle body as in claim 16, wherein the rotating element is substantially spherical shaped. 18. A throttle body as in claim 15, wherein the support element is substantially enclosed within the central wall. 19. A throttle body as in claim 15, further including a positioning element configured to adjust the position of the rotating element with respect to the shaft. 20. A throttle body as in claim 15, wherein the support element includes a receiving element configured to receive the rotating element. 21. A throttle body as in claim 12, wherein the bearing assembly selectively engages the shaft based upon the deflection of the shaft in the region of the central wall. | BACKGROUND 1. Field of the Invention This invention generally relates to an air intake control device. More specifically, the invention relates to a throttle body in an internal combustion engine having a dual bore throttle body. 2. Related Technology Throttle bodies regulate the airflow to an internal combustion engine where the air is mixed with gasoline. Internal combustion engines require a precise mixture of air and gasoline in order to run properly, and therefore throttle bodies are designed to adjustably control the airflow into the cylinders of the engine. In order to control the airflow that reaches the cylinders, the throttle body includes at least one throttle plate (hereinafter “plates”) attached to a throttle shaft and configured such that each throttle plate is located within the throttle bores, or proximal to an end of each of the throttle bores. With rotation of the shaft, the throttle plates are able to selectively obstruct airflow through the throttle bores. More specifically, the throttle plates are able to rotate with respect to each of the bores in order to adjust the cross-sectional area of the bores that is not obstructed by the plates (the “effective area”), thus controlling the airflow that is permitted to flow through the throttle bores. In order to effectively control the effective areas of the bores, the throttle plates are sized and shaped approximately the same as the cross-sections of the bores in order to completely or substantially obstruct the bores when a throttle plate is substantially perpendicular to the airflow (the “closed position”). Additionally, the throttle plates have a minimal thickness in order to not substantially obstruct the throttle bores when the plates are angled such that a throttle plate face is not substantially perpendicular to the airflow (the “open position”). During operation, when the engine is idling, the throttle plates are in the closed position because very little air is needed to mix with the small amount of fuel being injected into the engine. Conversely, the throttle plates are in a variety of open positions at operating speeds higher than idle because more air is needed to mix with the increased amount of fuel being provided to the engine. When the throttle plates are closed, pressure builds on the upstream face of the throttle plate, which is the side of the plate that is closer to the air intake when the throttle plate is closed. If the pressure on the upstream face of the throttle plate is high enough, it may cause the shaft to deflect towards the engine, which can cause unwanted contact between throttle body components, excessive friction between moving parts, and premature part failure. Plural-bore throttle bodies, such as dual-bore throttle bodies, are more susceptible to shaft deflection and premature part failure than single-bore throttle bodies due to length and the positioning of the dual-bore throttle shaft. Dual-bore throttle bodies include two bores and two throttle plates configured side-by-side on a common shaft. Thus, a dual-bore throttle shaft is approximately twice as long as a single-bore throttle shaft. Longer throttle shafts have a greater tendency to deflect than shorter throttle shafts. Additionally, dual-bore throttle bodies include a housing that forms the bores, and the housing typically includes an opening for rotatably receiving the approximate mid-point of the shaft. As with any rigid body, the shaft undergoes maximum deflection near its mid-point. Therefore, dual-bore throttle bodies are particularly susceptible to excessive wear at the point of contact between the throttle shaft mid-point and the housing support opening between the two bores. Therefore, it is desirous to minimize both the throttle shaft deflection and the friction between moving parts. SUMMARY In overcoming the disadvantages and drawbacks of the known technology, the current invention provides an assembly that limits the deflection of the throttle shaft and minimizes the sliding friction between the throttle body's moving parts. The throttle body includes a housing that defines at least two bores (hereinafter “bores”), which provide airflow to an internal combustion engine. In order to precisely control the airflow into the engine, the bores are coupled with throttle plates rotatably connected to a throttle shaft. The throttle plates are approximately the same size and shape as the bores (and are located inside or near the ends of the bores) such that the airflow through the bores is substantially minimized or completely eliminated when the plates are in a “closed” position. Connected to a rotatable shaft, rotation of the plates controls the amount of airflow through the bores. When the plates are in the closed position, air pressure builds up on one side of the plates and causes the shaft to deflect towards the housing. In order to minimize the friction between the shaft, which may be deflecting and/or rotating, and the housing, a bushing is inserted between the shaft and the midpoint support of the housing. The bushing may be connected to the housing and it may either selectively contact or permanently contact the shaft. More specifically, the shaft and bushing may only selectively contact each other during periods of shaft deflection or permanently contact each other regardless of shaft deflection. Preferably, the shaft and bushing selectively contact each other in order to minimize friction and part wear. The bushing may be of various constructions, such as a ring-shaped bushing, a spring bushing, or a bearing assembly. The ring-shaped bushing may be received in the housing via an opening that is concentric with the shaft. More specifically, the ring-shaped bushing is positioned in a recess in the midpoint support at the housing and the shaft extends through the housing and the ring-shaped bushing. Preferably, the bushing is inserted from one side of the midpoint support and includes a mechanism to limit the depth at which it is inserted into the midpoint support. The spring bushing may be include a slit that permits expansion of the spring bushing diameter. More specifically, as the slit expands, the spring bushing can be snapped over the shaft. Preferably, the spring bushing is received in a reduced diameter portion of the shaft and, in its free state, exhibits an outer diameter that is greater than the outer diameter of the shaft and an inner diameter that is greater than the diameter of the shaft's reduced diameter portion. The bearing assembly may include a rotating element that contacts the shaft and a support element that positions the rotating element with respect to the shaft. The rotating element may have a circular cross-section to create a smooth and continuous contact between the rotating element and the shaft, and the support element may be enclosed within the housing walls. The height of the rotating element with respect to the shaft may be adjustable. The current invention may also include a plurality of bearings to rotatably receive the shaft. Additionally, a spacer may be coupled with a bearing to form a substantially air-tight seal. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-section of a dual-bore throttle body assembly embodying the principles of the present invention; FIG. 2 is a close-up view of a partial cross-section of a second embodiment of the present invention, showing a spring bushing and a throttle shaft; FIG. 3a is a front view of the spring bushing shown in FIG. 2; FIG. 3b is a side view of the spring bushing shown in FIG. 3a; and FIG. 4 is a partial cross-section of a third embodiment of the present invention. DETAILED DESCRIPTION FIG. 1 shows a dual-bore throttle body 10, according to an embodiment of the present invention, used to control the airflow into an internal combustion engine of a motor vehicle. The dual-bore throttle body 10 is in fluid communication with the combustion cylinders of an internal combustion engine (not shown) and configured to control the airflow 28 into the cylinders. The dual-bore throttle body 10 includes a housing 14, preferably composed of aluminum material, defining a pair of bores 26 and rotatably receiving a shaft 12. A pair of throttle plates 16 (hereafter “plates”) are fixedly coupled with the shaft 12 such that the throttle plates 16 rotate along with the shaft 12. During operation, the shaft 12 and throttle plates 16 control the airflow 28 through the bores 26 in order to achieve the optimal mix of air and fuel within the engine. The shaft 12 is coupled with the housing 14 by bearings 22 to allow the shaft 12 to rotate with respect to the housing 14. The rotation of the shaft 12 is preferably controlled by a control device (not shown), such as a motor and a gear assembly, as will be further discussed below. The shaft 12 is typically composed of steel, brass, or similar materials. As the shaft 12 rotates, the throttle plates 16 likewise rotate and change the angle between the throttle plates 16 and the bores 26. The plates 16 are positioned and shaped such that the circumference 17 of the throttle plates 16 approximates the inner surface 27 of the bores 26. More specifically, a plate 16 substantially blocks airflow through a bore 26 when the plate 16 is perpendicular to the bore inner surface 27 (when the plate 16 is in the “closed position”). As the shaft 12 rotates and the plate 16 is no longer in the closed position, the plate 16 no longer substantially prevents airflow through the bore (the plate is in the “open position”). The plates 16 are typically constructed of brass, aluminum, or a similarly suitable material. During operation of the motor vehicle, airflow 28 from the exterior of the vehicle flows through the air induction system, into the bores 26 of the throttle assembly and towards the throttle plate top surface 16a. When the throttle plates 16 are in a closed position, as shown in FIG. 1, the pressure on the top surface 16a of the throttle plates 16 is greater than the resulting pressure on the bottom surface 16b. The pressure difference between the top surface 16a and the bottom surface 16b may cause the shaft 12 to deflect towards the housing lower surface 32, particularly at the midpoint of the shaft 12. In order to prevent premature part wear as a result of shaft deflection, a bushing comprised of a low friction material is inserted between the shaft 12 and a central wall 13 (the wall separating the two bores 27) of the housing 14. The low friction material in the bushing may be PTFE, such as Teflon™. In one embodiment, the bushing is a ring-shaped bushing 18 with a substantially circular cross-section. The ring-shaped bushing 18 forms a closed loop, and it is coupled with the housing 14 by sliding the ring-shaped bushing 18 over the shaft 12. In order to slide the ring-shaped bushing 18 onto the shaft 12 and into position in the central wall 13, an outer wall 15 of the housing 14 has a first bore 14a with a diameter at least as large as an outer diameter 31 of the ring-shaped bushing 18. The housing also has a second bore 14b with a diameter at least as large as the outer diameter of the shaft 12. The diameter of the second bore 14b is preferably smaller than that of the first bore 14a in order to minimize air leakage around the shaft 12. The ring-shaped bushing 18 may have a convex end face to be substantially flush with the bore 27. The flush connection between the ring-shaped bushing 18 and the bore 27 minimized leakage around the shaft 12 and minimizes turbulent air flow. The first bore 14a may be formed by drilling into the outer wall 15 and the central wall 13 along the machine path 20 shown in FIG. 1, or by other appropriate methods. The central wall 13 also preferably includes a shoulder 14c which separates the first and second bores 14a, 14b. The shoulder 14c is preferably substantially perpendicular to the first and second bores 14a, 14b in order to form an air-tight seal with the ring-shaped bushing 18. Formed in this manner, the ring-shaped bushing 18 can be inserted onto the shaft 12 and slid into the first bore 14a by press-fitting, or by some other appropriate coupling method. The ring-shaped bushing 18 abuts shoulder 14c for lateral support. In order to prevent excessive contact between the shaft 12 and the bushing 18, the inner diameter of ring-shaped bushing 18 is preferably greater than the diameter of the shaft 12. A gap 29 is thus located between the shaft 12 and the ring-shaped bushing 18 when the shaft 12 is in the undeflected position seen in FIG. 1. The gap 29 reduces contact between the shaft 12 and the ring-shaped bushing 18, minimizing premature part wear. As the shaft 12 deflects and contacts the ring-shaped bushing 18, the ring-shaped bushing 18 may or may not rotate along with the shaft 12, depending on the frictional forces between the shaft 12, the ring-shaped bushing 18, and the housing 14. Preferably, the ring-shaped bushing 18 does not rotate along with the shaft 12. The dual-bore throttle body 10 is preferably substantially airtight in order to precisely control the airflow 26 into the internal combustion engine. More specifically, the shaft 12, the bearings 22 and the housing 14 form airtight seals. In order to form the seal 25 at the outer wall 15, a spacer 24 is inserted between the first bore, the shaft 12 and the bearings 22. The spacer 24 is preferably plastic, but may be comprised of other suitable materials. FIGS. 2, 3a, and 3b show another embodiment of the present invention. In this embodiment, a spring bushing 34 is coupled with the housing's central wall 13 by a spring force 37 biased towards the central wall 13. The spring bushing 34 is substantially circular and provided with a slit 36 allowing the spring bushing diameter 50 to be adjustable. More specifically, as a force is applied perpendicularly to the spring bushing outer surface 35, the spring bushing diameter 50 decreases or increases, depending on the direction of the force. As shown in FIG. 2, when the spring bushing 34 is coupled with the central wall 13 of the housing 14, a housing force 39 is applied to the spring bushing 34 that causes the spring bushing diameter 50 to be smaller than when the spring bushing 34 is in its relaxed state. The shaft 12 in this embodiment preferably includes a reduced diameter section 12a, wherein the reduced diameter section 12a is smaller than the outer diameter of the shaft 12. When the spring bushing 34 is in a compressed state, the spring bushing diameter 50 is greater than the openings formed by the bearings 22. Additionally, when the spring bushing 34 is in a relaxed state, the spring pushing diameter 50 is greater than the opening formed by the central wall 13. Therefore, the spring bushing 34 is preferably installed according to the following steps. First, the shaft 12 is inserted through one of the bearings 22 until the reduced diameter section 12a of the shaft 12 is within one of the bores 26. Secondly, the spring bushing 34 is snapped onto the reduced diameter section 12aof the shaft 12. Finally, a radial force is applied to the spring bushing 34 such that the spring bushing diameter 50 is smaller than the opening formed by the central wall 13, and the spring bushing 34 and shaft 12 are inserted into the opening formed by the central wall 13. A pair of shoulders 12b connect the reduced diameter section 12a and the outer diameter of the shaft 12. During operation, the shoulders 12b limit the axial movement of the spring clip bushing 34. Similarly to the ring-shaped bushing 18, when the shaft 12 is undeflected, the spring bushing 34 does not contact the shaft 12 because the gap 46, between the spring bushing 34 and the reduced diameter section 12a, is smaller than the gap 48 between the central wall 13 and the outer diameter of the shaft 12. When the shaft 12 is deflected, the spring bushing 34 may or may not rotate along with the shaft 12 during contact between the spring bushing 34 and the rotating, deflected shaft 12. In order to further minimize shaft 12 wear, the slit 36 is preferably not substantially parallel to the shaft 12. If the slit 36 is parallel to the shaft 12, the shaft 12 may contact the spring bushing 34 along the length of the slit 36, which causes a high pressure area due to the relatively small contact area between the shaft 12 and spring bushing 36. Therefore, the slit 36 is formed at an angle 52 that is preferably 15° to 45° with respect to the shaft 12. More preferably, the slit angle 52 is 25° to 35° with respect to the shaft 12. FIG. 4 shows another embodiment of the present invention, including a bearing assembly 54. The bearing assembly 54 includes a rotatable element 56 rotatably received by a support element 58. The rotatable element 56 freely rotates with respect to the support element 58 in order to provide a low friction contact with the shaft 12 via rolling contact. More specifically, the rotatable element 56 rotates along with the shaft 12 when the shaft 12 and the rotatable element 56 contact each other. The rotatable element 56 and the shaft 12 preferably only contact each other during shaft 12 deflection. However, the rolling contact between the shaft 12 and rotatable element 56 causes less friction than the sliding contact between a stationary bushing and the shaft 12, so the part wear is minimal, even if continuous contact occurs between the shaft 12 and the rotatable element 56. In order to provide free rotation between the shaft 12 and the rotatable element 56, the rotatable element 56 has a substantially circular cross section taken along a plane perpendicular to the shaft 12. More preferably, the rotatable element 56 is spherical-shaped in order to provide static contact regardless of the angle of the contact. The support element 58 is preferably encased within the central wall 13 such that only the rotatable element 56 projects from the central wall 13. The support element 58 may also include a positioning element 60, such as a spring or a screw, to adjust the height of the rotatable element 56 with respect to the shaft 12. However, other appropriate configurations may be used to adjust the height of the rotatable element 56. The support element 58 includes a receiving end 62 that rotatably receives the rotatable element 56. Therefore, the shape and size of the receiving end 62 depend on the shape and size of the rotatable element 56. In FIG. 4, the receiving end 62 is cup-shaped to receive the spherical rotatable element 56. However, other appropriate configurations may be used. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention. | <SOH> BACKGROUND <EOH>1. Field of the Invention This invention generally relates to an air intake control device. More specifically, the invention relates to a throttle body in an internal combustion engine having a dual bore throttle body. 2. Related Technology Throttle bodies regulate the airflow to an internal combustion engine where the air is mixed with gasoline. Internal combustion engines require a precise mixture of air and gasoline in order to run properly, and therefore throttle bodies are designed to adjustably control the airflow into the cylinders of the engine. In order to control the airflow that reaches the cylinders, the throttle body includes at least one throttle plate (hereinafter “plates”) attached to a throttle shaft and configured such that each throttle plate is located within the throttle bores, or proximal to an end of each of the throttle bores. With rotation of the shaft, the throttle plates are able to selectively obstruct airflow through the throttle bores. More specifically, the throttle plates are able to rotate with respect to each of the bores in order to adjust the cross-sectional area of the bores that is not obstructed by the plates (the “effective area”), thus controlling the airflow that is permitted to flow through the throttle bores. In order to effectively control the effective areas of the bores, the throttle plates are sized and shaped approximately the same as the cross-sections of the bores in order to completely or substantially obstruct the bores when a throttle plate is substantially perpendicular to the airflow (the “closed position”). Additionally, the throttle plates have a minimal thickness in order to not substantially obstruct the throttle bores when the plates are angled such that a throttle plate face is not substantially perpendicular to the airflow (the “open position”). During operation, when the engine is idling, the throttle plates are in the closed position because very little air is needed to mix with the small amount of fuel being injected into the engine. Conversely, the throttle plates are in a variety of open positions at operating speeds higher than idle because more air is needed to mix with the increased amount of fuel being provided to the engine. When the throttle plates are closed, pressure builds on the upstream face of the throttle plate, which is the side of the plate that is closer to the air intake when the throttle plate is closed. If the pressure on the upstream face of the throttle plate is high enough, it may cause the shaft to deflect towards the engine, which can cause unwanted contact between throttle body components, excessive friction between moving parts, and premature part failure. Plural-bore throttle bodies, such as dual-bore throttle bodies, are more susceptible to shaft deflection and premature part failure than single-bore throttle bodies due to length and the positioning of the dual-bore throttle shaft. Dual-bore throttle bodies include two bores and two throttle plates configured side-by-side on a common shaft. Thus, a dual-bore throttle shaft is approximately twice as long as a single-bore throttle shaft. Longer throttle shafts have a greater tendency to deflect than shorter throttle shafts. Additionally, dual-bore throttle bodies include a housing that forms the bores, and the housing typically includes an opening for rotatably receiving the approximate mid-point of the shaft. As with any rigid body, the shaft undergoes maximum deflection near its mid-point. Therefore, dual-bore throttle bodies are particularly susceptible to excessive wear at the point of contact between the throttle shaft mid-point and the housing support opening between the two bores. Therefore, it is desirous to minimize both the throttle shaft deflection and the friction between moving parts. | <SOH> SUMMARY <EOH>In overcoming the disadvantages and drawbacks of the known technology, the current invention provides an assembly that limits the deflection of the throttle shaft and minimizes the sliding friction between the throttle body's moving parts. The throttle body includes a housing that defines at least two bores (hereinafter “bores”), which provide airflow to an internal combustion engine. In order to precisely control the airflow into the engine, the bores are coupled with throttle plates rotatably connected to a throttle shaft. The throttle plates are approximately the same size and shape as the bores (and are located inside or near the ends of the bores) such that the airflow through the bores is substantially minimized or completely eliminated when the plates are in a “closed” position. Connected to a rotatable shaft, rotation of the plates controls the amount of airflow through the bores. When the plates are in the closed position, air pressure builds up on one side of the plates and causes the shaft to deflect towards the housing. In order to minimize the friction between the shaft, which may be deflecting and/or rotating, and the housing, a bushing is inserted between the shaft and the midpoint support of the housing. The bushing may be connected to the housing and it may either selectively contact or permanently contact the shaft. More specifically, the shaft and bushing may only selectively contact each other during periods of shaft deflection or permanently contact each other regardless of shaft deflection. Preferably, the shaft and bushing selectively contact each other in order to minimize friction and part wear. The bushing may be of various constructions, such as a ring-shaped bushing, a spring bushing, or a bearing assembly. The ring-shaped bushing may be received in the housing via an opening that is concentric with the shaft. More specifically, the ring-shaped bushing is positioned in a recess in the midpoint support at the housing and the shaft extends through the housing and the ring-shaped bushing. Preferably, the bushing is inserted from one side of the midpoint support and includes a mechanism to limit the depth at which it is inserted into the midpoint support. The spring bushing may be include a slit that permits expansion of the spring bushing diameter. More specifically, as the slit expands, the spring bushing can be snapped over the shaft. Preferably, the spring bushing is received in a reduced diameter portion of the shaft and, in its free state, exhibits an outer diameter that is greater than the outer diameter of the shaft and an inner diameter that is greater than the diameter of the shaft's reduced diameter portion. The bearing assembly may include a rotating element that contacts the shaft and a support element that positions the rotating element with respect to the shaft. The rotating element may have a circular cross-section to create a smooth and continuous contact between the rotating element and the shaft, and the support element may be enclosed within the housing walls. The height of the rotating element with respect to the shaft may be adjustable. The current invention may also include a plurality of bearings to rotatably receive the shaft. Additionally, a spacer may be coupled with a bearing to form a substantially air-tight seal. | 20040202 | 20070410 | 20050804 | 97525.0 | 1 | ARGENBRIGHT, TONY MICHAEL | APPARATUS FOR CONTROLLING THROTTLE SHAFT DEFLECTION AND FRICTION IN DUAL BORE THROTTLE BODIES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,770,702 | ACCEPTED | Biological signal management | Systems and techniques for managing biological signals. In one implementation, a method includes receiving a cardiac biological signal that includes information describing events, determining a merit of each event based on one or more of a severity of a cardiac condition associated with the event and a quality of the event, and handling a subset of the events that meet a merit criterion. The subset can be handled for medical purposes. | 1. A method comprising: receiving a cardiac biological signal that includes an event relevant to a medical purpose; determining a merit of the event for the medical purpose; associating the event with a time span in which the event occurred if the event's merit is among a certain number of the most meritorious events that occurred in the time span; and handling the association of the time span and the event. 2. The method of claim 1, wherein determining the merit of the event comprises: determining a severity of the event; and determining an quality of the event. 3. The method of claim 2, wherein determining the quality of the event comprises determining the noise in the event. 4. The method of claim 1, wherein receiving the cardiac biological signal comprises receiving the event after the event has been separated from another portion of the cardiac biological signal. 5. The method of claim 1, further comprising identifying the event within the received cardiac biological signal. 6. The method of claim 5, wherein identifying the event comprises identifying one or more of an asystole event, a tachycardia event, a bradycardia event, and an atrial fibrillation/flutter event based on identifying characteristics of these events. 7. The method of claim 6, wherein identifying the event comprises identifying the event based on a frequency of heart beats. 8. The method of claim 1, wherein: the method further comprises determining a category of the event; and associating the event with the time span comprises associating the event with the time span when the event merit places the event within the certain number of the most meritorious events of the category. 9. The method of claim 1, wherein associating the event with the time span comprises associating the event with the time span when the event merit is among a predetermined number of the most meritorious events. 10. The method of claim 1, wherein handling the association comprises generating a data structure having a time stamp associated with the event. 11. The method of claim 1, wherein handling the association comprises transmitting the association to a remote receiver. 12. The method of claim 1, wherein the event has a greater relevance to a medical diagnostic purpose than an average relevance of the biological signal. 13. A method, comprising: receiving a cardiac biological signal that includes information describing events; determining a merit of each event based on one or more of a severity of a cardiac condition associated with the event and a quality of the event; and handling, for medical purposes, a subset of the events that have merits meeting a merit criterion. 14. The method of claim 13, wherein handling the subset of events comprises handling the subset of events meeting a merit criterion that is based on merits of other events. 15. The method of claim 13, wherein determining the merit of each event comprises determining the merit based on both the severity and the quality. 16. The method of claim 13, wherein handling the subset comprises handling the events that have merits among a certain number of the most meritorious. 17. The method of claim 13, wherein handling the subset of the events comprises handling the subset of the events that occur within a certain time span. 18. The method of claim 17, wherein handling the subset of the events comprises handling the subset of the events that occur within a predetermined time span. 19. The method of claim 13, wherein handling the subset of the events comprises transmitting the subset of events to a remote medical receiver. 20. A method comprising: receiving a biological signal; identifying an event in the biological signal, the event of greater relevance for a certain purpose than an average relevance of the biological signal; determining a merit of the event for the certain purpose; comparing the merit of the event with a second merit of a second event to identify a more meritorious event; creating an episode describing the more meritorious event; associating the episode with a time span in which the events occurred; and transmitting the association of the episode and the time span to a remote receiver. 21. The method of claim 20, wherein associating the episode with the time span comprises creating a data structure including the episode and a time stamp indicating when the event occurred. 22. The method of claim 20, wherein creating the episode comprises: redacting the more meritorious event. 23. The method of claim 20, wherein: the method further comprises determining a category of the event; and comparing the merit of the event with the second merit of the second event comprises comparing the merit of the event with the second merit of the second event of the same category. 24. The method of claim 20, further comprising associating the association of the episode and the time span with a collection of associations of episodes and time spans. 25. The method of claim 24, wherein transmitting the association comprises transmitting the collection of associations of episodes and time spans. | BACKGROUND This disclosure relates to the management of biological signals. Biological signals are electrical or optical streams that include information describing or otherwise relating to the state of a biological system. In the medical context, biological signals generally include information relating to the physiological state of an organism. Such information can be used to diagnose and treat disease states of the organism and can be gathered using any of a number of different techniques. Examples of such techniques include electrical potential measurements (e.g., electrocardiography (ECG's), electromyography, and electroencephalography), blood and other body fluid analyte measurements (e.g., pulse oximetry, blood glucose concentration, blood pH and other ion concentrations), and mechanical measurements (e.g., blood pressure measurements, heart sound transduction, height and weight measurements). SUMMARY The biological signal management systems and techniques described here may include various combinations of the following features. In one aspect, a method includes receiving a cardiac biological signal that includes an event relevant to a medical purpose, determining a merit of the event for the medical purpose, associating the event with a time span in which the event occurred if the event's merit is among a certain number of the most meritorious events that occurred in the time span, and handling the association of the time span and the event. The merit of the event can be determined by determining the severity and the quality of the event. The quality of the event can be determined by determining the noise in the event. An event can be received after the event has been separated from another portion of the cardiac biological signal. The event can also be identified within the received cardiac biological signal. The event can be one or more of an asystole event, a tachycardia event, a bradycardia event, and an atrial fibrillation/flutter event based on identifying characteristics of these events. The event can be identified based on a frequency of heart beats. A category of the event can be determined. The event can be associated with the time span when the event merit places the event within the certain number of the most meritorious events of the category. The number of the most meritorious events can be predetermined. The association can be handled by generating a data structure having a time stamp associated with the event or by transmitting the association to a remote receiver. The event can have a greater relevance to a medical diagnostic purpose than an average relevance of the biological signal. In another aspect, a method includes receiving a cardiac biological signal that includes information describing events, determining a merit of each event based on one or more of a severity of a cardiac condition associated with the event and a quality of the event, and handling a subset of the events that meet a merit criterion. The subset can be handled for medical purposes. The merit criterion can be based on merits of other events. The merit of each event can be determined based on both the severity and the quality of the event. The subset can be the events that have merits among a certain number of the most meritorious and the subset can be the events that occur within a certain time span. For example, the time span can be predetermined. The subset of events can be transmitted to a remote medical receiver. In another aspect, a method includes receiving a biological signal, identifying an event in the biological signal, determining a merit of the event for the certain purpose, comparing the merit of the event with a second merit of a second event to identify a more meritorious event, creating an episode describing the more meritorious event, associating the episode with a time span in which the events occurred, and transmitting the association of the episode and the time span to a remote receiver. The event can have a greater relevance for a certain purpose than an average relevance of the biological signal. The episode can be associated with the time span by creating a data structure including the episode and a time stamp indicating when the event occurred. The episode can be created by redacting the more meritorious event. A category of the event can also be determined. The merit of the event can be compared with the second merit of the second event of the same category. The association of the episode and the time span can be associated with a collection of associations of episodes and time spans. The resulting collection of associations of episodes and time spans can be transmitted to the remote receiver. These biological signal management systems and techniques may provide one or more of the following advantages. For example, the management of biological signals can facilitate a coherent approach to organization and presentation of the information contained in the biological signals. Such management must address various objectives that often oppose one another. For example, the volume of data often should be reduced to minimize data handling costs. At the same, relevant information should not be lost. These objectives are of importance in the medical context, where data review may be carried out by a physician or other trained personnel and hence may prove costly. On the other hand, discarding medically relevant information may hinder or even prevent appropriate diagnosis and/or treatment. The described biological management systems and techniques can address these and other objectives by increasing the average relevance of data that is handled. Such reductions in data clutter can be used to quickly provide physicians with relevant information, decreasing the cost of data review and increasing the likelihood that diagnosis and/or treatment is appropriately delivered. Another set of opposing objectives relates to the timing of data handling. In many data handling systems, continuous handling of data is simply too costly. On the other hand, batch handling that only occurs occasionally may result in improper delays. These objectives are also of importance in the medical context, where continuous data handling may be unnecessary or too costly, but delayed handling may endanger patients. The described biological management systems and techniques can address these and other objectives by selecting the timing of data handling to accommodate both the realities of data handling and the need to ensure patient safety. For example, the timing of handling can be selected to ensure timeliness in any prophylactic or diagnostic efforts without requiring continuous processes. The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. DESCRIPTION OF DRAWINGS FIG. 1 shows a system in which a biological signal is monitored for medical purposes. FIG. 2 shows an example biological signal. FIG. 3 shows a series of events in the biological signal of FIG. 2. FIG. 4 illustrates how certain characteristics can be used to identify events. FIGS. 5 and 6 show the biological signal of FIG. 2 divided into a collection of time spans. FIGS. 7 and 8 show data structures that associate one or more events with a time span. FIG. 9 shows a process in which events are associated with a time span. FIG. 10 shows a process for determining a measure of the merit for an event. FIG. 11 shows a data structure that can result from handling of events associated with time spans. FIG. 12 shows a data assembly that can result from handling of events associated with time spans. FIGS. 13 and 14 illustrate the handling of events associated with time spans by transmission to a receiver. FIG. 15 shows a system in which events associated with time spans are handled by transmission to a receiver. Like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION FIG. 1 shows a system 100 in which a biological signal derived from an individual is monitored for medical purposes. System 100 includes an individual 105, instrumentation 110, a signal path 115, and a receiver 120. Individual 105 can be a patient or a healthy individual for whom monitoring of one or more biological signals is deemed to be appropriate. Instrumentation 110 can include one or more sensing, calibration, signal processing, control, data storage, and transmission elements suitable for generating and processing the biological signal, as well as relaying all or a portion of the biological signal over path 115. Path 115 can be any suitable medium for data transmission, including wired and wireless media suitable for carrying optical and/or electrical signals. The receiver 120 can include a receiver element for receiving the transmitted signal, as well as various data processing and storage elements for extracting and storing the information carried by the transmission regarding the state of individual 105. The receiver 120 can be a medical system in that receiver 120 presents information to medical personnel or to a medical expert system for analysis. The receiver 120 either can reside remotely from instrumentation 110 in that receiver 120 is not located at the same site (e.g., at the same hospital, nursing home, or other medical care facility) as instrumentation 110 or the receiver 120 can reside within the same general area or vicinity as instrumentation 110 (e.g., within the same room, building, or health care facility). FIG. 2 shows an example of a biological signal 200. The biological signal 200 is a time variant signal in that an attribute 205 of biological signal 200 changes with time 210. Attribute 205 of biological signal 200 may continuously change with time and may never reach a steady state value as activity level, metabolic rate, or other factors vary over the course of days, weeks, or even longer periods of time. Although attribute 205 of biological signal 200 may change continuously, all of the changes may not have the same relevance to a particular purpose for which the biological signal 200 is monitored. FIG. 3 shows the biological signal 200 having a series of events 305, 310, 315, 320, 325, 330, 335, 340, 345 identified. Events 305, 310, 315, 320, 325, 330, 335, 340, 345 generally are periods in time 210 when the information content of biological signal 200 is deemed to be of increased relevance to a particular purpose for which biological signal 200 is monitored. Events 305, 310, 315, 320, 325, 330, 335, 340, 345 need not be of equal or predetermined duration. For example, event 335 is shorter than event 320 and the duration of these and other events can depend on the nature of the increased relevance to the particular purpose for which biological signal 200 is monitored. The increased relevance of events 305, 310, 315, 320, 325, 330, 335, 340, 345 can be determined using a number of approaches. For example, events 305, 310, 315, 320, 325, 330, 335, 340, 345 can represent responses to known or controlled stresses on an organism. Events 305, 310, 315, 320, 325, 330, 335, 340, 345 also can be identified based on characteristics of biological signal 200 and classified into categories based on the identifying characteristics. Tables 1 and 2 lists example categories of cardiac events and characteristics that can be used to identify the events. The characteristics identified in Tables 1 and 2 can be used to identify events during cardiac monitoring using electrocardiography. FIG. 4 illustrates an example of how the characteristics identified in Table 1 can be used to identify cardiac events. In this example, the attribute 205 of biological signal 200 that changes with time 210 (shown in seconds) is heart rate (shown in beats per minute (bpm)). In the illustrated example, the predetermined heart rate for identifying Moderate Bradycardia is 60 bpm and the predetermined duration is 40 seconds. The predetermined heart rate for identifying Severe Bradycardia is 40 bpm and the predetermined duration is 15 seconds. In FIG. 4, heart rate attribute 205 drops below 60 bpm at time 405, where it remains until TABLE 1 Event Category Identifying Characteristic(s) Duration VFIB Ventricular fibrillation NA Long Pause/ No QRS detected for a predetermined duration. e.g., 3 to 6 Asystole seconds VTACH Four or more V-beats in row and heart rate more 4 V-beats than a predetermined value (e.g., 100 to 200 bpm). Not associated with a VFIB event Patient Patient indicates event is occurring Patient selected initiated event Severe Heart rate over a predetermined time (e.g., 10 to 120 e.g., 10 to 120 Tachycardia seconds) is greater than a predetermined value (e.g., seconds 161 to 220 bpm) Not associated with a VTACH or a VFIB event Severe Heart rate over a predetermined time (e.g., 10 to 120 e.g., 10 to 120 Bradycardia seconds) is less than a predetermined value (e.g., 30 seconds to 39 bpm) Not associated with an asystole or pause event Atrial Heart rate greater than or equal to a predetermined e.g., 10 to 120 Fibrillation/ value (e.g., 100 to 220 bpm) seconds Flutter with Associated with an Atrial Fibrillation/Flutter onset High HR event Pause No QRS complex for a predetermined duration (e.g., e.g., 2 seconds 2 seconds to duration of Long Pause/Asystole event) to duration of Long Pause/ Asystole event Atrial Irregular rhythm e.g., 30 QRS Fibrillation/ Not associated with a VTACH and VFIB event complexes Flutter onset Moderate Heart rate for a predetermined duration (e.g., 10 to e.g., 10 to 120 Bradycardia 120 seconds) is less than a predetermined value and seconds greater than predetermined value in a severe bradycardia event (e.g., severe bradycardia value to 60 bpm) Not associated with an asystole, a pause, or a severe bradycardia event Moderate Heart rate for a predetermined duration (e.g., 10 to e.g., 10 to 120 Tachycardia 120 seconds) is greater than a predetermined value seconds and less than predetermined value in a severe tachycardia event (e.g., 100 bpm to the severe tachycardia value) Not associated with a VTACH, a VFIB, or a severe tachycardia event time 410, 40 seconds later. The period between time 405 and time 410 can be identified as a Moderate Bradycardia event. In contrast, at time 415, heart rate attribute 205 drops below 40 bpm where it remains until time 420, ten seconds later. Heart rate attribute 205 also reaches a minimum of 35 bpm at a time 425. Despite reaching this minimum, the duration of the period between time 415 and time 420 (i.e., 10 seconds) is too short to be identified as a Severe TABLE 2 EXAMPLE EVENT IDENTIFYING IDENTIFYING CATEGORY CHARACTERISTICS THRESHOLD TACHYCARDIA Sustained heart rate (e.g., heart rate for 10 to 1 - Sustained heart rate exceeds 1 - Severe Tachycardia 120 seconds) exceeds a heart rate threshold a High Heart Rate (HHR) 2 - Moderate threshold of 190 bpm Tachycardia 2 - Sustained heart rate exceeds a Low Heart Rate (LHR) threshold of 140 bpm ATRIAL Loss of synchrony between the atria and the 1 - Heart rate exceeds a Atrial FIBRILLATION ventricles (shown, e.g., by variability in Fibrillation High Heart Rate 1 - Atrial Fibrillation/ beat-to-beat period) (AFHHR) threshold of 130 bpm Flutter with High 2 - No heart rate threshold HR 2 - Atrial Fibrillation PAUSE No QRS detected for a specified threshold 1 - No QRS for a high threshold 1 - Asystole duration of 4 seconds 2 - Pause 2 - No QRS for a low threshold of 2 seconds BRADYCARDIA Sustained heart rate (e.g., heart rate for 10 to 1 - Sustained heart rate is below 1 - Severe Bradycardia 120 seconds) is below a specified threshold a Low Heart Rate (LHR) 2 - Moderate threshold of 35 bpm Bradycardia 2 - Sustained heart rate is below a High Heart Rate (HHR) threshold of 40 bpm Bradycardia event. At time 430, heart rate attribute 205 again drops below 40 bpm, where it remains until time 435, five seconds later. The duration of the period between time 430 and time 435 is too short to be identified as a Severe Bradycardia event. FIGS. 5 and 6 show that time 215 can be divided into a collection of time spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625. Spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625 can have equal durations (such as spans 505, 510, 515, 520, 525) or spans can be of variable durations (such as spans 605, 610, 615, 620, 625). In general, the duration of spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625 is proportional to the duration of the events sought to be identified. The duration of spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625 can be selected based on consideration of two or more factors, such as the number of events likely to occur in each span and the need to handle events for a particular purpose for which biological signal 200 is monitored. In particular, if spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625 are too short, then spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625 may lack an event. On the other hand, if spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625 are too long, then the delay in handling events may be too large. Such a delay may be particularly harmful in the medical context, where an excessive delay may hinder prophylactic or diagnostic efforts. In the context of cardiac monitoring, a span duration of between one half and four hours, such as between one and three hours or approximately two hours, is effective to address such considerations. The duration of spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625 can also accommodate physiological rhythms of a biological system. For example, in cardiac monitoring, longer spans may be appropriate at night or periods of decreased activity and shorter spans may be appropriate during the day or periods of increased activity. The duration of spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625 can also be adjusted based on an attribute of biological signal 200. For example, in cardiac monitoring, the duration of spans 505, 510, 515, 520, 525, 605, 610, 615, 620, 625 can include a fixed number of beats rather than a fixed time period. FIGS. 7 and 8 show data structures 700, 800 that associate one or more sample events with a span. Data structures 700, 800 can be used together or separately as alternative approaches to associating events with a span. Data structure 700 includes an event field 705 and a time stamp field 710. Event field 705 includes data describing a portion of a biological signal that has been identified as an event. Event field 705 can include raw data drawn from the biological signal or event field 705 can include an episode of an event to describe the event. An episode is a collection of information that summarizes the relevance of the event to the purpose for which the event is monitored. For example, an episode can be a redacted portion of an event (e.g., the first three minutes worth of the event). Time stamp field 710 includes data describing the time when the event described in event field 705 occurred. Time stamp field 710 can thus associate the event with a span by identifying a time that falls within the time span. Data structure 800 is shown as a table of attribute-value pairs but other data structures (including, for example, records, files, lists, and other data structures) that associate similar information can be used. Data structure 800 includes an event category information field 805, span identification information field 810, and allocation information fields 815, 820, 825. Event category information field 805 describes one or more event categories that are allocable to data structure 800. An event category can be described by name, by an associated identification number or other token, or by a pointer or other description of a memory location that includes such information. Span identification information field 810 describes the time span from which events of a category identified in event category information field 805 are allocable to data structure 800. The time span can be described directly using, e.g., a start and stop time stamp, or the time span can be described indirectly by a pointer or other description of a memory location that includes such information. Each instance of data structure 800 can be specific to a single span. Allocation information fields 815, 820, 825 each describe a certain event that is allocated to data structure 800. An event can be allocated to data structure 800 when the event is of a category described in event category information field 805 and when the event occurred in a time span described in span identification information field 810. Such allocations thus associate the event with the described category and time span. Allocation information fields 815, 820, 825 can describe an event by including an event field and a time stamp field, such as fields 705, 710 of data structure 700 (FIG. 7). Data structure 800 can include one or more allocation information fields. Single allocation fields decrease the size of data structure 800 and may facilitate handling. Multiple allocation fields increase the number of events associated with the span identified by span identification information field 810 and may provide more complete information when data structure 800 is handled. FIG. 9 shows a process 900 in which events are associated with a time span. Events can be associated with a time span by allocation to a data structure such as data structures 700, 800. The process 900 can be performed by one or more data processing devices that perform data processing activities. The activities of process 900 can be performed in accordance with the logic of a set of machine-readable instructions, a hardware assembly, or a combination of these and/or other instructions. The device performing process 900 can be deployed at any of a number of different positions in a system in which a biological signal is monitored. For example, in system 100 (FIG. 1), the device performing process 900 can be deployed at instrumentation 110 or at receiver 120. The device performing process 900 receives the biological signal at 905. The biological signal can be received in raw form or after signal processing. The biological signal can be received in digital or analog format. The receiving device can identify and classify one or more events in the biological signal at 910. Events can be identified and classified based on one or more attributes of the biological signal, such as the identifying characteristics described in Table 1. The device performing process 900 can also determine a measure of the merit of identified events at 915. A measure of the merit of an event is a valuation of an event when applied to a particular purpose. For example, when the biological signal is monitored for diagnostic medical purposes, the measure of the merit of an event can describe the diagnostic value of the information content of the event. The measure of the merit of an event can be based on a number of factors, including whether or not the event is representative of the biological signal or of other events of the same category in the biological signal, the quality (e.g., noise or signal dropout) associated with the event, and even the category of the event itself. The device performing process 900 can determine if the measure of the merit of an event identified at 910 is greater than the measure of the merit of the least meritorious event of the same category currently associated with the time span that includes the identified event at decision 920. The least meritorious event of the same category can be associated with the time span in a data structure such as data structures 700, 800 (FIGS. 7 and 8). The determination can be made by comparing the measure of the merit of the identified event with the measure of the merit of the associated, least meritorious event of the same category. If the identified event is not as meritorious, the device performing process 900 can discard the identified event at 925. On the other hand, if the identified event is more meritorious than the associated, least meritorious event of the same category, then the device performing process 900 can discard the latter at 930 and associate the more meritorious event identified at 910 with the time span at 935. For example, the device performing process 900 can allocate the more meritorious event identified at 910 to the appropriate of fields 715, 805, 810 in data structures 700, 800 (FIGS. 7 and 8). The device performing process 900 can determine if the end of a time span in the biological signal has been reached at decision 940. If the end of the span has not been reached, the process 900 returns to 910 to identify and classify any additional event(s) in the biological signal. If the end of the span has been reached, the process proceeds to handle the allocated events at 945. The events can be handled alone or in association with other information, including duration and classification information, prior and subsequent events of the same or different categories, and additional information retrieved from other biological signals. TABLE 3 Event Event Category Grade VFIB 1 Long Pause/ 1 Asystole VTACH 1 Patient initiated 1 event Severe 1 Tachycardia Severe 1 Bradycardia Atrial 2 Fibrillation/ Flutter with High HR Pause 2 Atrial 2 Fibrillation/ Flutter onset Moderate 2 Bradycardia Moderate 2 Tachycardia FIG. 10 shows a process 1000 for determining a measure of the merit of an event. A data processing device can perform the process 1000 in isolation or as part of a larger process. For example, the process 1000 can be performed within process 900 at 915 (FIG. 9). The device performing process 1000 can determine the severity of an event at 1005. The severity of an event is a measure of the gravity of the event to the purpose for which the biological signal is monitored. For example, when the biological signal is monitored for diagnostic medical purposes, the severity of an event can be indicative of the individual's physical discomfort or hardship associated with a diagnosis that can be made using the event. Severity can be graded on a discrete scale or on a continuous scale. Table 3 shows example discrete grades of the severity of various cardiac events when cardiac monitoring is performed for prophylactic and diagnostic purposes. In Table 3, events are graded on a two point scale, with an event grade of “1” indicating that the event is more severe and an event grade of “2” indicating that the event is less severe (e.g., a moderately sever event). For example, event grade “1” can indicate an acute medical condition that requires immediate medical attention, whereas event grade “2” can indicate a chronic or other medical condition that does not require immediate medical attention. Another approach to determining the severity of an event involves comparing characteristics of the biological signal during the event with threshold values relating to various physiological conditions associated with the events. For example, for a tachycardia event as described in Table 2, the severity of a tachycardia event can be determined using Equation 1: Tachy Severity=(Heart Rate−Low Heart Rate)/(High Heart Rate−Low Heart Rate) Equation 1 Similarly, the severity of a Bradycardia event, and Atrial Fibrillation Event, and a Pause event can be determined using the appropriate of Equations 2-4: Brady Severity=(High Heart Rate−Low Heart Rate)/(High Heart Rate−Low Heart Rate) Equation 2 AFIB Severity=Heart Rate/Atrial Fibrillation High Heart Rate Equation 3 Pause Severity=(Pause Duration−Low Threshold)/(High Threshold−Low Threshold) Equation 4 The device performing process 1000 can also determine the quality of the event at 1010. The quality of the event is a measure of the likelihood that the event is suited to the purpose for which the biological signal is monitored. One factor that can impact quality is the amount or type of noise in the biological signal during the event. For example, when the biological signal is a cardiac signal monitored for diagnostic medical purposes, noise can be determined using approaches such as those described in Wang, J. Y. “A New Method for Evaluating ECG Signal Quality for Multi-lead Arrhythmia Analysis,” appearing in Proceedings of IEEE Computers in Cardiology Conference 2002, pp. 85-88 and U.S. Pat. No. 5,967,994 to Jyh-Yun Wang, the contents of both of which are incorporated herein by reference. Quality can be graded on a discrete scale or on a continuous scale. TABLE 4 Severity Noise Quality Low High Lowest Low Medium Low Low Low Low Medium High Low Medium Medium Medium Medium Low High High High Low High Medium High High Low High The device performing process 1000 can determine the measure of the merit of an event based at least in part on the severity and quality of the event at 1015. The measure of the merit can be graded on a discrete scale or on a continuous scale. The measure of the merit can be determined using any of a number of different approaches. Table 4 includes examples of various discrete merit grades (lowest, low, medium, and high) that can be assigned to an event when an event is determined to have the corresponding severity and quality. The handling of allocated events, such as those allocated during a process such as process 900, can involve any of a number of different activities. For example, event handling can include notifying medical personnel about the event. Such notification can be performed in response to the identification of an event associated with an acute medical condition, such as those events graded level “1” in Table 3. Event handling can also include the assembly of more complex data structures, the transmission of allocated events to, for example, a receiver such as receiver 120 (FIG. 1), or the storage of allocated events (for example, in anticipation of assembly into more complex data structures or transmission). Such data structure assembly, transmission, and storage can be performed with events associated with medical conditions that do not require immediate medical attention, such as those graded level “2” in Table 3. FIG. 11 shows a data structure 1100 that can result from handling of events associated with time spans. The events and time spans can be associated by repeated performance of process 900 by a data processing device. Data structure 1100 includes a data assembly 1105, a series of associated events 1110, and a series of discarded events 1115. Data assembly 1105 includes a collection of time span records, including time span records 1120, 1125, and 1130. Time span records 1120, 1125, 1130 can include information identifying the duration of an associated time span. For example, time span record 1120 can include information identifying that span record 1120 lasts from 12 AM to 6 AM, whereas time span record 1130 can include information identifying that span record 1130 lasts from 4 PM to 6 PM. Time span records 1120, 1125, 1130 can include information identifying one or more categories of events associated with time span records 1120, 1125, 1130, as well as a severity of any associated category of events. For example, data structure 1100 can be devoted to events of a certain severity, such as level 2 events as discussed above. Associated events 1110 includes a collection of event records of one or more categories, including event records 1135, 1140, 1145, 1150. Associated events 1110 can be allocated to the time spans in data assembly 1105 by allocation to an appropriate time span record. Event records can include data describing the event (such as raw data from the relevant portion of biological signal 200). Associated events 1110 can be allocated to the appropriate time span records through a series of pointers 1155. For example, event records 1135, 1140, 1145 are allocated to time span record 1120 through a first pointer 1155, whereas event record 1150 is associated with time span record 1125 through a second pointer 1155. A time span record need not have an associated event record. For example, no event record is associated with time span record 1130. This lack can reflect that no appropriate event was identified within the time span associated with time span record 1130. Discarded events 1115 includes a collection of event records of one or more categories. Discarded events 1115 are not associated with the time spans in data assembly 1105 or with any of allocated events 1110. FIG. 12 shows another data assembly, namely a data collection 1200, that can result from handling of events associated with time spans. Data collection 1200 includes a data collection title 1205, data collection metadata 1210, and a series of data structures 1215. Data collection title 1205 can include information identifying data collection 1200. Data collection metadata 1210 can include information about the data in collection 1200, such as the subject of the biological signal, parameters regarding the instrument used to generate the biological signal, and date and location information regarding the data generation process. Series of data structures 1215 includes data structures 1220, 1225, 1230. Each data structure 1220, 1225, 1230 can result from associating events of different categories with time spans and can include one or more events of different categories. For example, each data structure 1220, 1225, 1230 can include a data structure such as data structure 1100. Since each data structure 1220, 1225, 1230 can include events from different categories selected for high information content, data collection 1200 can include a relatively large amount of information regarding a biological signal but yet retain a high density of information content. FIGS. 13 and 14 illustrate another way that events associated with time spans are handled, namely by transmission to a receiver in a system such as receiver 120 in system 100. In particular, as shown in FIG. 13, data can be gathered and events can be allocated at instrumentation 110 to form one or more of assemblies of data such as data structures 700, 800, 1100 and data collection 1200. In response to a trigger, data assemblies can be relayed over path 115 to receiver 120, where they are received as shown in FIG. 14. Example triggers include the passage of a predetermined period of time, user input indicating that transmission is appropriate, or the identification of an event of sufficient severity to warrant immediate transmission. FIG. 15 shows one implementation of system 100 in which a biological signal derived from an individual is monitored for medical purposes. System 100 includes individual 105, instrumentation 110, signal path 115, and receiver 120. Instrumentation 110 can be adapted for electrocardiographic monitoring of individual 105. Instrumentation 110 can include a sensor module 1505 and a monitor module 1510. Sensor module 1505 can include three ECG leads with electrodes, as well as a two channel ECG signal recorder and a wireless and/or wired data output. Sensor module 1505 can also include a clip for attaching sensor module to a belt, a neckpiece, or other item worn by individual 105. Monitor module 1510 includes a data input that is adapted to receive data output from sensor module 1505 as well as one or more wireless and/or wired data outputs for data communication over signal path 115. Monitor module 1510 also includes a data processing device that performs data processing activities in accordance with the logic of a set of machine-readable instructions. The instructions can be realized in digital electronic circuitry, integrated circuitry, specially designed ASICs (application specific integrated circuits), computer hardware, firmware, software, and/or combinations thereof. The instructions can describe how to identify and/or handle events in accordance with one or more of the techniques described herein. In one implementation, monitor module 1510 also includes an input/output device for interaction with a user (such as an event trigger input with which a user can manually trigger the start of an event. Signal path 115 can include one or both of a wired data link 1515 and a wireless data link 1520 coupled to a data network 1525 to place instrumentation 110 in data communication with receiver 120. Wired data link 1515 includes a public network portion 1530 and a private or virtual private network portion 1535 bridged by a server 1540. Public network portion 1530 provides for data communication between instrumentation 110 and server 1540 over a wired data link such as a telephone network. Private network portion 1535 provides for private or virtually private data communication from server 1540 to receiver 120. Server 1540 can interface for data communication with both portions 1530, 1535. For example, server 1540 can communicate directly with receiver 120 using the peer-to-peer protocol (PPP). Wireless data link 1545 can include one or more wireless receivers and transmitters 1550 such as a WiFi receiver, a cellular phone relay station, and/or other cellular telephone infrastructure to place instrumentation 110 in data communication with data network 1525. In turn, data network 1525 communicates with receiver 120. Receiver 120 includes a receiver server 1555, a data storage device 1560, a call router 1565, a communications server 1570, and one or more application servers 1575 that are all in data communication with one another over one or more data links 1580. Receiver server 1555 is a data processing device that receives and transmits communications over signal path 115 and relays incoming communications to data storage device 1560 and call router 1565 in accordance with the logic of a set of machine-readable instructions. Data storage device 1560 is a device adaptable for the storage of information. Data storage device 1560 can be a volatile and/or non-volatile memory that records information electrically, mechanically, magnetically, and/or optically (such as a disk drive). Call router 1565 is a data processing device that, in accordance with the logic of a set of machine-readable instructions, identifies the content of an incoming communication and directs the communication to one or more appropriate application servers 1575 based on that content. Communications server 1570 is a data processing device that relays communications between call router 1565 and one or more application servers 1575 over an external network. Application servers 1575 are data processing devices that interact with a user or operate in isolation to provide one or more monitoring services in accordance with the logic of a set of machine-readable instructions. Data links 1580 can be part of a local area and/or private network or part of a wide area and/or public network. In operation, sensor module 1505 can sense, amplify, and record electrical signals relating to the activity of the heart. Sensor module 1505 can also relay all or a portion of those signals to monitor module 1510 where they can be managed. For example, monitor module 1510 can manage the signals in accordance with one or more of processes 900 and 1000 (FIGS. 9-10). As part of the management, monitor module 1510 can transmit the signals to receiver 120. The signals can be transmitted in association with a time span. For example, the signals can be transmitted in one or more of data structures 700, 800, 1100, 1200 (FIGS. 7-8 and 11-12). The transmitted signals pass along data link 115 over one or more of wired data link 1515 and wireless data link 1520 to receiver 120. At receiver 120, the signals are received by server 1555 which causes at least a portion of the incoming signals to be stored on data storage device 1560 and relayed to call router 1565. The incoming signals stored on data storage device 1560 can be stored in one or more of data structures 700, 800, 1100, 1200 (FIGS. 7-8 and 11-12). The incoming signals relayed to call router 1565 are directed to one or more appropriate application servers 1575 based on the content of the signals. For example, when the signal relates to a certain category of cardiac event, the signal can be directed to a certain application server 1575 that is accessible to a cardiologist having expertise with that certain category of event. As another example, when the signal originates with an individual who is under the care of a particular physician, the signal can be directed to a certain application server 1575 that is accessible to that physician. As yet another example, when the signal relates to a certain category of cardiac event, the signal can be directed to a certain application server 1575 that accesses an expert system or other set of instructions for diagnosing and/or treating that category of event. When appropriate, a signal can be routed to communications server 1570 which in turn relays the signal to the appropriate application server 1575 over an external network. Communications can also be relayed from receiver 120 back to individual 105 or to other individuals. For example, when a physician or expert system identifies that care is needed, a message requesting that the individual seek care can be returned to individual 105 over data link 115. In urgent care situations, third parties such as medical personnel can be directed to individual 105, either by receiver 120 or by instrumentation 110. Various implementations of the systems and techniques described here can be realized in digital electronic circuitry, integrated circuitry, specially designed ASICs (application specific integrated circuits), computer hardware, firmware, software, and/or combinations thereof. These various implementations can include one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device. These computer programs (also known as programs, software, software applications or code) may include machine instructions for a programmable processor, and can be implemented in a high-level procedural and/or object-oriented programming language, and/or in assembly/machine language. As used herein, the term “machine-readable medium” refers to any computer program product, apparatus and/or device (e.g., magnetic discs, optical disks, memory, Programmable Logic Devices (PLDs)) used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term “machine-readable signal” refers to any signal used to provide machine instructions and/or data to a programmable processor. To provide for interaction with a user, the systems and techniques described here can be implemented on a computer having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input. The systems and techniques described here can be implemented in a computing environment that includes a back-end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front-end component (e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back-end, middleware, or front-end components. The components of the environment can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (“LAN”), a wide area network (“WAN”), and the Internet. The computing environment can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. For example, information included in any of the data structures can be handled as meta data describing the data structures themselves and hence still associated with the data structures. An event can be associated with a time span based on the merit of the event exceeding a certain threshold. All events that exceed such a threshold can remain associated with the time span, rather than be discarded. Accordingly, other implementations are within the scope of the following claims. | <SOH> BACKGROUND <EOH>This disclosure relates to the management of biological signals. Biological signals are electrical or optical streams that include information describing or otherwise relating to the state of a biological system. In the medical context, biological signals generally include information relating to the physiological state of an organism. Such information can be used to diagnose and treat disease states of the organism and can be gathered using any of a number of different techniques. Examples of such techniques include electrical potential measurements (e.g., electrocardiography (ECG's), electromyography, and electroencephalography), blood and other body fluid analyte measurements (e.g., pulse oximetry, blood glucose concentration, blood pH and other ion concentrations), and mechanical measurements (e.g., blood pressure measurements, heart sound transduction, height and weight measurements). | <SOH> SUMMARY <EOH>The biological signal management systems and techniques described here may include various combinations of the following features. In one aspect, a method includes receiving a cardiac biological signal that includes an event relevant to a medical purpose, determining a merit of the event for the medical purpose, associating the event with a time span in which the event occurred if the event's merit is among a certain number of the most meritorious events that occurred in the time span, and handling the association of the time span and the event. The merit of the event can be determined by determining the severity and the quality of the event. The quality of the event can be determined by determining the noise in the event. An event can be received after the event has been separated from another portion of the cardiac biological signal. The event can also be identified within the received cardiac biological signal. The event can be one or more of an asystole event, a tachycardia event, a bradycardia event, and an atrial fibrillation/flutter event based on identifying characteristics of these events. The event can be identified based on a frequency of heart beats. A category of the event can be determined. The event can be associated with the time span when the event merit places the event within the certain number of the most meritorious events of the category. The number of the most meritorious events can be predetermined. The association can be handled by generating a data structure having a time stamp associated with the event or by transmitting the association to a remote receiver. The event can have a greater relevance to a medical diagnostic purpose than an average relevance of the biological signal. In another aspect, a method includes receiving a cardiac biological signal that includes information describing events, determining a merit of each event based on one or more of a severity of a cardiac condition associated with the event and a quality of the event, and handling a subset of the events that meet a merit criterion. The subset can be handled for medical purposes. The merit criterion can be based on merits of other events. The merit of each event can be determined based on both the severity and the quality of the event. The subset can be the events that have merits among a certain number of the most meritorious and the subset can be the events that occur within a certain time span. For example, the time span can be predetermined. The subset of events can be transmitted to a remote medical receiver. In another aspect, a method includes receiving a biological signal, identifying an event in the biological signal, determining a merit of the event for the certain purpose, comparing the merit of the event with a second merit of a second event to identify a more meritorious event, creating an episode describing the more meritorious event, associating the episode with a time span in which the events occurred, and transmitting the association of the episode and the time span to a remote receiver. The event can have a greater relevance for a certain purpose than an average relevance of the biological signal. The episode can be associated with the time span by creating a data structure including the episode and a time stamp indicating when the event occurred. The episode can be created by redacting the more meritorious event. A category of the event can also be determined. The merit of the event can be compared with the second merit of the second event of the same category. The association of the episode and the time span can be associated with a collection of associations of episodes and time spans. The resulting collection of associations of episodes and time spans can be transmitted to the remote receiver. These biological signal management systems and techniques may provide one or more of the following advantages. For example, the management of biological signals can facilitate a coherent approach to organization and presentation of the information contained in the biological signals. Such management must address various objectives that often oppose one another. For example, the volume of data often should be reduced to minimize data handling costs. At the same, relevant information should not be lost. These objectives are of importance in the medical context, where data review may be carried out by a physician or other trained personnel and hence may prove costly. On the other hand, discarding medically relevant information may hinder or even prevent appropriate diagnosis and/or treatment. The described biological management systems and techniques can address these and other objectives by increasing the average relevance of data that is handled. Such reductions in data clutter can be used to quickly provide physicians with relevant information, decreasing the cost of data review and increasing the likelihood that diagnosis and/or treatment is appropriately delivered. Another set of opposing objectives relates to the timing of data handling. In many data handling systems, continuous handling of data is simply too costly. On the other hand, batch handling that only occurs occasionally may result in improper delays. These objectives are also of importance in the medical context, where continuous data handling may be unnecessary or too costly, but delayed handling may endanger patients. The described biological management systems and techniques can address these and other objectives by selecting the timing of data handling to accommodate both the realities of data handling and the need to ensure patient safety. For example, the timing of handling can be selected to ensure timeliness in any prophylactic or diagnostic efforts without requiring continuous processes. The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. | 20040202 | 20090908 | 20050804 | 94992.0 | 2 | BERTRAM, ERIC D | BIOLOGICAL SIGNAL MANAGEMENT | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,770,745 | ACCEPTED | Garage door remote monitoring and actuating system | A system typically comprising a garage module that is coupled with a garage door opener and a remote module is disclosed. The remote module and the garage module are coupled for communication therebetween through an AC power grid of an associated building. The remote module includes an indicator that informs the user whether or not an associated garage door has been left open and permits the user to close the garage door using the remote module. Optionally, the system includes accessory modules typically for turning on one or more lamps when the garage door is opened so that a user can enter a lit home and need not fumble to find a light switch. Additionally, the garage module includes laser pointer that activate when a user opens a garage door and provide a convenient visual indicator to assist the user in parking his/her vehicle in a desired location. | 1. A garage door status monitoring and actuating system comprising: A first garage module adapted to be coupled to a first garage door opener and to actuate the first garage door opener, the garage module including a first transceiver; A first garage door position sensor adapted for being coupled with the first garage module; A first remote module adapted to be located remotely from the first garage module within a building, the first remote module including a second transceiver, a first indicator, and a first switch; and Wherein (i) the first transceiver is adapted to send a first signal to the second transceiver when the garage door position sensor is in a first state, (ii) the first remote module is adapted to activate the first indicator upon receipt of the first signal, (iii) the second transceiver is adapted to send a second signal when the first switch is activated, and (iv) the first garage module is adapted to actuate the garage door opener upon receipt of the second signal. 2. The garage door status monitoring and actuating system of claim 1, wherein the first and second transceivers are adapted to transmit the first and second signals over the power grid of the building. 3. The garage door status monitoring and actuating system of claim 2, wherein the signals comply with X-10 standards. 4. The garage door status monitoring and actuating system of claim 1, further comprising (1) a second garage module, the second garage module including a third transceiver and being adapted to be coupled to a second garage door, and (2) a second garage door position sensor adapted for being coupled with the second garage module, wherein (i) the third transceiver is adapted to send the first signal to the second transceiver when the second garage door position sensor is in a first position, (ii) the second garage module is adapted to actuate the second garage door opener upon receipt of the second signal. 5. The garage door status monitoring and actuating system of claim 1, wherein the first garage module is only adapted to actuate the first garage door opener to close an associated garage door. 6. The garage door status monitoring and actuating system of claim 4, wherein the first and second garage modules are only adapted to actuate respective first and second garage door openers to close associated garage doors. 7. The garage door status monitoring and actuating system of claim 1, further comprising a second remote module including a third transceiver, the second remote module being adapted to be located remotely from the first garage module within the building, the second remote module including a second indicator and a second switch, wherein the (i) the second remote module is adapted to activate the second indicator upon receipt of the first signal, and (ii) the third transceiver is adapted to send the second signal when the second switch is activated. 8. The garage door status monitoring and actuating system of claim 1, wherein the first garage module further comprises at least one laser-pointing device, wherein the first garage module is adapted to activate the laser pointing device for a period of time following the change of the first garage door position sensor from a second state to a first state. 9. The garage door status monitoring and actuating system of claim 1, wherein the first garage door position sensor comprises a magnetic sensor switch and associated magnetic sensor. 10. The garage door status monitoring and actuating system of claim 1, further comprising an accessory module, the accessory module including a receiver, an automatic switch and an electrical outlet, wherein (i) the accessory module is adapted to actuate the automatic switch upon receipt of the first signal. 11. The garage door status monitoring and actuating system of claim 10, wherein the first transceiver is further adapted to send a third signal generally contemporaneously with the first signal, and wherein the accessory module is adapted to actuate the automatic switch upon receipt of the third signal. 12. A garage door status monitoring and actuating system comprising: a garage module electrically coupled with a garage door opener and an AC power grid of an associated building, the garage module including a first transceiver adapted to transmit at least a first signal over the power grid and receive a second signal over the power grid; a garage door position sensor mounted proximate a garage door, the garage door position sensor being coupled with the garage door module, the garage door position sensor having at least two states, a first state when the garage door is at least partially open and a second state when the garage door is completely closed; A remote module electrically coupled with the AC power grid of the associated building, the remote module including (i) a second transceiver adapted to transmit at least the second signal over the power grid and receive the first signal, (ii) a user actuatable switch, and (iii) a visual indicator; and Wherein (a) the first signal is transmitted by the garage module when the garage position sensor moves into the first state, (b) the remote module upon receiving the first signal activates the visual indicator to indicate the garage door is open, (c) the remote module transmits the second signal when the switch is depressed, and (d) the garage module upon receiving the second signal activates the garage door opener to close the garage door. 13. The garage door status monitoring and actuating system of claim 12, further comprising an accessory module, the accessory module including a receiver, an automatic switch, and an electrical outlet, the accessory module being connected to the AC power grid and having a lamp plugged into the electrical outlet, wherein (i) the accessory module is adapted to actuate the automatic switch upon receipt of the third signal from the garage module and turn on the lamp. 14. The garage door status monitoring and actuating system of claim 12, wherein the garage module further comprises one or more laser pointers and a timed switch, wherein the timed switch activates the one or more laser pointers when the first garage door position sensor changes from a second state to a first state, and the timed switch deactivates the one or more laser pointers after a predetermined span of time has passed. 15. The garage door status monitoring and actuating system of claim 12, further comprising a second garage module and a second garage door position sensor, the second garage door module electrically coupled to a second garage door opener and including a third transceiver adapted to transmit at least the first signal over the power grid and receive the second signal over the power grid, the second position sensor mounted proximate a second garage door, the second garage door position sensor being coupled with the second garage door module, the second garage door position sensor having at least two states, a first state when the garage door is at least partially open and a second state when the garage door is completely closed. 16. The garage door status monitoring and actuating system of claim 12, further comprising a second remote module, the second remote module including (i) a third transceiver adapted to transmit at least the second signal over the power grid and receive the first signal, (ii) a second user actuatable switch, and (iii) a second visual indicator, wherein (a) the second remote module upon receiving the first signal activates the second visual indicator to indicate the garage door is open, and (b) the second remote module transmits the second signal when the switch is depressed. 17. The garage door status monitoring and actuating system of claim 12, wherein the garage module is adapted only to activate the garage door opener to close the garage door and not to open the garage door. 18. A method of operating a garage door status monitoring and actuating system, the method comprising in the provided order: sending a first signal over an associated building's power grid from a garage module to a remote module; activating a visual indicator at the remote module indicating an associated garage door is open; sending a second signal over the associated building's power grid from the remote module to the garage module upon activating a switch on the remote module by the user; and activating the garage door opener to close the garage door after receiving the second signal. 19. The method of claim 18, further comprising sending a third signal, and after the third signal is sent, turning on a lamp by activating an automatic switch in an accessory module. 20. The method of claim 18, further comprising activating one or more laser pointers of the garage module generally contemporaneously with said sending the first signal. | FIELD OF THE INVENTION The invention relates generally to automatic garage door openers, and more particularly to a system for indicating whether a garage door is open and for activating the garage door opener from a remote location to close or open the door. BACKGROUND Automatic garage door opening systems have become very popular in the past twenty years such that residences wherein a person has to manually open and close the garage door are the rare exception. The typical garage door opener system comprises an electric motor unit mechanically coupled to the garage door through an associated track mechanism, a wireless receiver electrically connected to an actuation switch circuit of the motor unit, one or more actuators mounted at convenient locations in the garage for opening and closing the garage door, and a wireless remote control device typically kept in a vehicle for opening and closing the garage door from within the vehicle. Almost universally, garage door opener systems also include a safety sensor that prevents the garage door from closing if a person or any object is in the path of the closing door. This safety feature prevents the garage door from injuring a child or a pet that might be in the door's path, and it also prevents the garage door from damaging inanimate objects, such as a vehicle that has not been fully pulled into the garage. Unfortunately, typical garage door opener systems have no way of alerting a user if the garage door has been left open unintentionally. Many users routinely push an actuator next to the door into their residence to close the garage door as they enter their residence. Commonly, the user does not wait to see if the door completely closes. Accordingly, if an object such as a child's toy is located in the path of the door, or the safety sensor is misaligned, the door with will not close and will automatically return to its fully open position. Additionally, many garage door opener users will for whatever reason just leave the garage door open and forget to close it before they retire for the evening. Many people keep valuable items in their garages such as power tools and bicycles that can be easily taken from the garage by nefarious individuals who pass by an open and tempting garage during the night when most if not all of the applicable residence's occupants and the occupants of neighboring residences are asleep. It is not uncommon for a homeowner to have something of value taken from their garages at some point in their lives because they mistakenly left the garage door open. Various remote monitoring systems are known that indicate to a person located in a remote location from the garage door, such as in a bedroom of the associated residence, whether or not the garage door is open. Examples of such systems are described in the following U.S. Pat. Nos. 6,597,291; 6,522,258; 6,184,787; 6,049,285; 6,166,634, 5,883,579; and 5,689,236. While the specifics of these systems vary, none of them provide any mechanism for closing the door from the remote location. Rather, the person noticing the signal from the device that the garage door is open has to get up, walk over to the garage door, and activate the garage door opener to close the garage door. This can be an inconvenience, especially when the room the person is coming from is on a second floor. Other systems are known that automatically close an open garage door without input of a person after the satisfaction of specific criteria. U.S. Pat. Nos. 4,463,292, 5,510,686, 5,752,343, 6,469,464, and 6,563,278 all teach systems that automatically closes a garage door after a set time interval. U.S. Pat. No. 5,752,343 also teaches a device that will close the door when it becomes dark. Unfortunately, if there is something blocking the door, the door will not shut and a person will have no idea the door was not in fact closed. Additionally, these devices have the potential to lock the owner out of their home if the door automatically closes while they are outside. SUMMARY According to one embodiment of the invention, a garage door status monitoring and actuating system comprises a first garage module adapted to be coupled to a first garage door opener and to actuate the first garage door opener. The garage module includes a first transceiver. The system also includes (i) a first garage door position sensor adapted for being coupled with the first garage module, and (ii) a first remote module adapted to be located remotely from the first garage module within a building. The first remote module includes a second transceiver, a first indicator, and a first switch. Operationally, the first transceiver is adapted to send a first signal to the second transceiver when the garage door position sensor is in a first state. The first remote module is adapted to activate the first indicator upon receipt of the first signal. The second transceiver is adapted to send a second signal when the first switch is activated, and the first garage module is adapted to actuate the garage door opener upon receipt of the second signal. According to another embodiment of the invention, a garage door status monitoring and actuating system comprises a garage module that is electrically coupled with a garage door opener and an AC power grid of an associated building. The garage module includes a first transceiver adapted to transmit at least a first signal over the power grid and receive a second signal over the power grid. The garage module also includes a garage door position sensor that is mounted proximate a garage door. The garage door position sensor is coupled with the garage door module, the garage door position sensor has at least two states, a first state when the garage door is at least partially open and a second state when the garage door is completely closed. The system further includes a remote module electrically coupled with the AC power grid of the associated building. The remote module includes (i) a second transceiver adapted to transmit at least the second signal over the power grid and receive the first signal, (ii) a user actuatable switch, and (iii) a visual indicator. Operationally, the first signal is transmitted by the garage module when the garage position sensor moves into the first state. The remote module, upon receiving the first signal, activates the visual indicator to indicate the garage door is open. The remote module transmits the second signal when the switch is depressed, and the garage module, upon receiving the second signal, activates the garage door opener to close the garage door. According to yet another embodiment of the invention a method of operating a garage door status monitoring and actuating system is described. The method comprises in the provided order: (i) sending a first signal over an associated building's power grid from a garage module to a remote module; (ii) activating a visual indicator at the remote module indicating an associated garage door is open; (iii) sending a second signal over the associated building's power grid from the remote module to the garage module upon activating a switch on the remote module by the user; and (iv) activating the garage door opener to close the garage door after receiving the second signal. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of a garage module according to one embodiment of the present invention. FIG. 2 is an isometric view of a plug-in remote module according to one embodiment of the present invention. FIG. 3 is an isometric view of a hardwired remote module according to one embodiment of the present invention. FIG. 4 is an isometric view of a plug-in accessory module according to one embodiment of the present invention. FIG. 5 is an isometric view of a screw in accessory module according to one embodiment of the present invention. FIG. 6 is a graphical waveform illustration of AC current also showing pulse bit signals transmitted by the modules of one embodiment of the present invention. FIG. 7 is a block diagram illustrating the various modules of one embodiment of the present invention. FIG. 8 is a flow chart illustrating the operation of one embodiment of the present invention. DETAILED DESCRIPTION An Overview A system for remotely monitoring whether a garage door is open and for remotely closing the garage door from the monitoring location is described. The system typically includes a garage module that is connected to a garage door opener, and one or more remote modules that indicate usually via an LED whether the garage door is open and include a switch that can be activated by a user to activate the garage door opener by way of the garage module and close the garage door. Accordingly, a user having a remote module located for instance in his/her bedroom does not need to leave the bedroom to close the garage door before retiring for the evening. In a preferred embodiment, the system is flexible permitting multiple remote modules to be located in various locations around a building or residence wherein a user can close the garage door from any one of the remote modules. Furthermore, the remote modules are not hard wired to the garage unit and accordingly can be moved from one location to another with ease without the need to reconfigure the remote module or rewire a connection between the remote module and the garage module. In a variation of the preferred embodiment, both the garage module and the remote module(s) plug into the AC power grid of the associated building to both provide power to the modules and to provide a path for transmission and reception of signals relayed between the garage and remote modules. Advantageously, by plugging the remote unit into any outlet within a particular building, the remote module can establish communication with the garage module. Also because a wireless transmission means is not utilized in the preferred variation, it will not interfere or be interfered with by other wireless devices being utilized in a building, such as cordless telephones, wireless networks, and certain remote control devices. However, in certain variations of the preferred embodiment, modules including wireless transceivers can be utilized in place of the power grid transceivers. One signal transmission protocol utilized in preferred variations of the preferred embodiment is X-10. The X-10 protocol is described in “Digital X-10” by Phillip Kingery, which is included as Appendix A, fully incorporated by reference, and can also be found on the World Wide Web at http://www.hometovs.com/htinews/feb99/articles/kingery/kingery 13.htm. By using the X-10 protocol, other X-10 compatible modules can be incorporated to provide added functionality to the system. For instance, an accessory module can be provided wherein the garage module can signal the accessory module to turn on a light in the building when the garage door is opened. Further, the garage module configured to signal the light to turn off after a predetermined period of time has passed. As many accessory modules as desired can be incorporated into the system such that the act of opening a garage door can cause many if not all of the lamps in a building to turn on. It is to be appreciated, however, that alternative variations of the preferred embodiment can use a power grid signal transmission protocol that is different from the X-10 protocol but effectively accomplish a similar result. In other variations of the preferred embodiment, one or more laser pointers are provided with the garage module. The pointers can be positioned to point to a specific spot on an associated properly parked vehicle. Typically, the pointer(s) illuminate when the garage door is opened for a preset period of time. Accordingly, a user in the vehicle can maneuver the vehicle as he/she pulls it into the garage such that the point of light coincides with the specific spot on the vehicle to indicate the vehicle is properly parked. Terminology The term “or” as used in this specification and the appended claims is not meant to be exclusive rather the term is inclusive meaning “either or both”. References in the specification to “one embodiment”, “an embodiment”, “a preferred embodiment”, “an alternative embodiment” and similar phrases means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. The term “couple” or “coupled” as used in this specification and the appended claims refers to either an indirect or direct connection between the identified elements or objects. Often the manner of the coupling will be related specifically to the manner in which the two coupled elements interact. For example, two elements are electrically coupled if electrical current can travel from one element to another even if the elements are not directly connected to one another but rather by way of a wire or other electrically conductive trace. Further, two elements can be operatively coupled if they are in communication with each other. For example, a wireless sensor can be operatively coupled to a wireless receiving device if signals are sent form the sensor to the receiving device for use by the receiving device. The term “switch” as used in this specification and the appended claims refers to any device for directly or indirectly opening or closing a conductive electrical path including but not limited to rotary switches, slide switches, rocker switches, touch sensitive switches, toggle switches, push buttons, pressure switches, and sensor switches. The term “state” as used in this specification and the appended claims refers a condition of an associated object whether physical or otherwise. For instance, a switch in a first state can be in the “off” position and in the “on” position in a second state. Alternatively, a semiconductor device can be in a first state when it is conductive and a second state when it is nonconductive even through the physical condition of the device is unchanged (at least on a non-atomic level). One First Preferred Embodiment Referring to FIGS. 1-5, the various components of a preferred embodiment of the garage door monitoring and garage door closing system are illustrated. The typical system includes: (i) a garage module 100 as best illustrated in FIG. 1; (ii) at least one remote module 200; and (iii) an optional accessory module 300. Referring to FIG. 1, the garage module comprises a housing 105 containing a power supply, a controller, and a power grid transceiver (see FIG. 7). Typically, the housing is either metal or plastic although the particular material is not considered particularly important so long as it can protect the electronic circuitry contained therein. An AC power cord 110 with a standard two or three prong plug extends from the housing. The cord serves to both supply power to the module, as well as, provide a connection with the building's power grid for the transmission and receipt of signals. Extending from the right and left sides of garage module are laser pointers 115 that are mounted to the housing via ball and socket or other flexible joints 120 to permit the pointers to be aimed to point at a desired spot. The pointers are electrically coupled to the controller and help guide a driver of a vehicle pulling into an associated garage to properly position the vehicle within the garage. Two pair of wires 125 and 130 extend from the front side of the module. The first pair of wires typically includes bare wire or spade connector ends to connect to the garage door opener. The second pair of wires are coupled with a position sensor 135, such as a magnetic switch, that indicates whether the associated garage door is open or closed. In alternative embodiments a terminal strip can be provided in place if the two pairs of wires extending from the garage module. Referring to FIG. 2, a typical remote module comprises a housing 205 typically made of a plastic or metallic material. In a preferred form, the remote module is a self-contained wall unit that simply plugs into an open AC receptacle by way of AC outlet prongs 210 that extend from the backside of the module. Advantageously, a user can quickly and easily move the remote module from room to room without difficulty. Contained inside the housing are a power supply, a remote module controller, and a power grid transceiver (see FIG. 7). Both the power supply and the transceiver are coupled to the AC outlet prongs so that the power grid of the building can be used to send and receive signals from the garage module, as well as, provide power to the module. On the front side of the housing, a visual indicator 215 typically in the form of a LED or other type of lamp is provided to indicate whether an associated garage door is open. A second visual indicator 220 may also be provided to indicate that the door is closed. Typically, the LED of the second indicator will be of a different color than the LED of the first visual indicator 215 and may be smaller as well so that a user quickly glancing at the remote module is unlikely to confuse the meaning of either visual indicator. Finally, a switch 225, typically in the form of a push button, is provided for initiating the remote module to send a signal to the garage model to activate the garage door opener and close the associated garage door. In addition to the plug-in remote module illustrated in FIG. 2, a hard-wired remote module can be utilized as illustrated in FIG. 3. A typical hard-wired module is designed to attach to a typical household switch box via a pair of screws 230 that passes through the modules faceplate 235. Similar to the plug-in module, open and closed garage door status visual indicator LEDs 215 & 220 and the door closing switch 225 are provided on the face plate of the module. Also, the hardwired remote includes a housing 205 containing the power supply, transceiver and controller. Unlike the plug in module, the hardwired module includes at least two wires 240 or a terminal block (not shown) for connecting the module into the power grid of the associated building. Two optional accessory modules are illustrated in FIGS. 4 & 5. These two modules are commonly available standard X-10 modules utilized in home automation applications. The plug-in module of FIG. 4 comprises a housing 305, a plug 310 extending from the backside of the housing for interfacing with a common household receptacle, a receptacle 315 for receiving the lamp or other device to be turned off and on by the module, and a coupe of rotary switches 320 to set the signal codes for the module. A screw in module for receipt into a standard light fixture is illustrated in FIG. 5. This module comprises a housing 325, a threaded male section 330 to be screwed into the light fixture and a corresponding threaded female section 335 to receive a standard light bulb therein. The signal codes for this module are set by sending the desired codes to the module in a particular sequence wherein the module is configured to turn off or on based on those codes thereafter. Either module can be configured to automatically turn on associated lights when triggered by the garage module such as when a garage door is initially opened. Furthermore, the garage module can be configured to send out an “off” signal to turn off the lights attached to the modules after a preset period of time has passed. There is no limit to the number of modules that can be utilized in a particular building. A user might have a single module to turn on a single lamp or he/she can have many modules to effectively light up the entire house. As mentioned above, the various modules of the first preferred embodiment transmit and/or receive various signals over the power grid of an associated building using the X-10 protocol. Other protocols for signal transmission can be utilized or proprietary protocols can be developed to accomplish the same results. However, the use of the X-10 standard increases the potential versatility of the system permitting the user to utilize off the shelf X-10 components such as the previously described lamp modules. Referring to FIG. 6, typical X-10 signals are transmitted as 1 ms voltage pulse bits 405 just after each zero crossing 410 of the associated buildings AC current signal 415. In North America, AC power is transmitted at 60 Hz with two zero crossings in each complete cycle resulting in 120 zero crossings per second. Information is transferred using binary code wherein the presence of a pulse comprises a “1” bit and the absence of a pulse comprises a “0” bit. The various sequences of binary bits are interpreted by the modules that either act based on the signals being broadcast by another module or ignore the signals if they do not pertain to the particular module. FIG. 6 graphically illustrates a sequence of pulse bits that can be utilized by the garage module to notify the remote module that the garage door is open. The transmission comprises an address sequence 420 that alerts the target receiving modules and a command sequence 425 that instructs the receiving modules to carry out a particular action. A transmitting module first sends out a start signal 430 comprising three pluses and then no pulse on the fourth crossing representing the binary code “1110”. The start code indicates to any X-10 module connected to the power grid that additional signals will be sent thereafter. Effectively, the start code acts to synchronize all the receivers of the various modules with the transmitter. Next a “house code” 435 (or “letter code” is transmitted starting with the next zero crossing after the start code has been completed and comprises four crossings (or 4 bits) in total to indicate to the modules whether the ensuing signal is intended for them. For simplicity, the house codes are designated as the letters A-P. If the receiving module is not set to the indicated house code then it ignores the subsequent transmission of pulses as the signal is not intended for it. If the house code matches the house code to which the module is set, it awaits the next set of pulses from the receiver. Once the house code has been sent, all the appropriate remote and accessory modules of the system will be alerted to await the “Unit Code” 440. In the first preferred embodiment, the modules are also set to a house code of G. However, the modules can be reconfigured if necessary to utilize one of the other house codes. The need to reprogram the modules for a different house code may arise if the particular building in which the garage door monitoring and actuation system is being installed already has an X-10 automation system operating on the power grid that utilizes the “G” house code for other purposes. The “unit code” 440 comprises five zero crossings wherein the last crossing is always a “0” that acts to designate the preceding pulses as being part of a “unit code”. Accordingly, there are 16 different unit codes. Each unit code typically pertains to a particular module type. For instance, in the preferred embodiment the default unit codes are 14, 15 and 16. “14” is used to identify the one or more remote modules as the intended recipients of the signal. “15” is used to identify the one or more garage modules as the intended recipients, and “16” is used to identify the one or more accessory modules as the intended recipients. Of course, different unit codes can be utilized and the preferred embodiment does provide for the reconfiguring of the system, if necessary, to avoid conflict with other X-10 devices and modules. Pertaining to FIG. 6, the unit code pertains to the number “14”, which means the accessory module can ignore the following “command codes”. Once the unit code has been received, the transmitter (the garage module in this example) retransmits the start code, house code and unit code sequence for purposes of redundancy and reliability. Next, a command sequence is sent twice over the power grid for the appropriate modules identified in the proceeding address sequence to receive the sequence and act upon it. The command sequence is transmitted after 6 zero crossings 445 of silence and comprises the same start code 430 described above, the letter code 435 associated with the particular modules identified during the address sequence, and a 5-bit command code 450. The command code always ends in a “1” bit to differentiate it from a unit code. There are 16 different command codes but only a few commands are typically utilized in the present invention. The “door open” command comprises the binary sequence “11011” and is utilized in the present example by the garage module to signal the remote module that the garage door is open. As indicated above the first preferred embodiment of the invention uses house code “G” and unit codes 14, 15 and 16 to refer to the remote, the garage, and the accessory modules respectively. In certain instances, such as when an associated residence is already using an X-10 automation system or when a neighboring system is interfering with the user's system, the user may need to reprogram one or both of the house code 435 and the unit codes 440. Accordingly, the preferred embodiment of the present invention is configured to permit a user to change both the house code and the unit codes of the garage module and the remote module from the remote module. In other words, the house and unit codes are remotely reprogrammed for the garage module from the remote module. The house or unit codes for any accessory modules are typically changed manually at each accessory module although in variations of the preferred embodiment, the accessory modules can also be configured for remote programming. To change the house code 435, a user first plugs the remote and garage modules into the same power grid. Next, the user presses and holds the close button 225 for 10 seconds until the open door visual indicator 215 illuminates to indicate the remote module has been placed in its setup mode. Next, the user presses and releases the close button a number of times corresponding to the desired house code. For instance, if the user desires it to set the unit to a house code of D, the user would press and release the close button four times. The last press of the button is held for at least three seconds causing the new house code to be stored in the remote module. Next, the close button 225 is pressed and released a number of times corresponding to the desired unit code 440 of the remote module. The last press is held for three seconds or more causing the new unit code to be stored in the remote module. The remote module will then indicate the new settings by flashing the open door visual indicator 215 the number of times corresponding to the new house code 435 and after a three second delay flashing the open door visual indicator the number of times corresponding to the new unit code. Simultaneously, using standard X-10 transmission protocols the remote module will transmit the new house code and a new unit code for the garage module to the garage module. Note that the unit code for the garage module will be one greater than the unit code for the remote module (i.e. if the remote module unit code is 10, the unit code of the garage module will be 11). After the transmission of the new codes to the garage module is complete and if the garage module is equipped with laser pointers 115 then the laser pointers will flash the garage module's new house and unit code. Of course, other methods of reprogramming the house and unit codes may be utilized in variations of the preferred embodiment and alternative embodiments. A block diagram indicating how the various components interface is illustrated in FIG. 7. One garage module 505, one remote module 510 and one optional accessory module 515 are illustrated and are all coupled to receive and/or send signals via a power grid of an associated building. It is to be appreciated as described below in a later section tat more than one module of any type can be utilized in a particular system. The power grid 520 serves two functions for each of the modules: (1) it provides power to the modules through an associated power supply 565, 570 & 575; and (2) serves as the conduit for signals transmitted and received by the transceivers 525 & 530 and received by the receiver 535 of the respective modules. Each module further includes a controller 540, 545 & 550 that either causes (i) the associated module to perform an action based on a signal received by the module, or (ii) the transceiver to transmit a signal based on input from a switch (or sensor) associated with the particular module. Concerning the garage module 505, the garage module is configured to receive a “close door” signal from the remote module 510. In response, the controller signals to the garage door to close the door. A garage door position sensor 555 is coupled with the module to indicate the relative position of the garage door. Typically, the garage door position sensor comprises a simple on/off two position magnetic switch that only indicates whether the door is fully closed or at least partially open. In variations of the preferred embodiments, the sensor can comprise any suitable sensor including, but not limited to, a beam sensor and a mechanical switch. When the associated garage door is opened moving the sensor into its “off” position, the garage module's controller reacts by causing the transmitter 525 to transmit the appropriate signal to the remote module 510. The controller may also cause the laser pointers 560 to activate and send another signal to the accessory module 515 to turn on a light attached to the accessory module. The garage module controller further includes a timer circuit that causes the controller to turn off the laser pointers after a certain period of time has past or to send a signal to the accessory module to switch off after another (or the same) period of time has passed. Concerning the remote module 510, its controller 545 upon a receipt of a first signal that the garage door is open causes a signal indicator 590, such as an LED, to be activated indicating to a viewer that the garage door is open. The controller is also coupled with a user activated switch 585 or button that when activated send a signal to the garage module to close signal the garage door opener 580 to close the garage door. Concerning the accessory module 515, its controller 550 responds to signals received by its receiver 535 (the accessory module does not have the capability to transmit signals). According to the signal received the controller causes an automatic switch 595 to turn on or off either activating or deactivating a lamp or other appliance coupled with the module typically through an outlet 597. Operation of the Preferred Embodiment FIG. 8 is a flow chart illustrating the operation of a typical garage door monitoring and actuation system according to the preferred embodiment. Referring to block 605, a user opens the garage door in a typical manner such as activating the garage door opener from an in-vehicle remote. As the garage door opens, the garage door position sensor is moved from the closed position to the open position indicating to the garage module that the garage door is at least partially open. In response to the open garage door, the garage module turns on the one or two laser pointers attached to the module as indicated in block 610. As described above, the laser pointers are typically attached to the housing of the garage module via ball and socket or other flexible connections. The laser pointers can be pointed to a particular reference location in the garage. Typically, the laser pointers are aimed at a reference point on a vehicle that is normally parked in the associated garage. Accordingly, a user when parking can maneuver the vehicle to align the reference point on the vehicle with the laser to ensure the vehicle is properly positioned in the garage. As a predetermined period of time has passed, such as 2 minutes, the laser pointer(s) will be automatically turned off by the garage module as indicated in block 615. Also in response to the opening of the garage door, the garage module will send an “open” signal to the remote module as indicated in block 620. In response to this signal as shown in block 625, the remote module will activate its visual indicator to alert any person who looks at the remote module that the garage door is open. The indicator, which typically comprises an LED in the preferred embodiments of the invention, will remain activated until the remote module has received a signal from the garage module indicating that the garage door has been closed. A variation of the preferred remote module embodiment may also include an audio alert signal which is momentarily activated whenever the “open signal is received. A user, who notices the visual or audio indicator is active, can attempt to close the garage door from location of the remote module by activating a close door switch or button on the remote module as indicated in block 630. In one preferred embodiment of the system, the visual indicator is an LED that flashes when the garage door switch has been activated and presumably the garage door is being closed. In response to the activation of the close door switch, the remote module sends a “close door” signal to the garage module as indicated in block 635 that causes the garage module upon receipt of the signal to trigger the garage door opener to activate and close the garage door as indicated in block 640. In one preferred embodiment, if the garage position sensor does not indicate the garage door has closed after 20 seconds the garage module will attempt to close the garage door a second time. If after two attempts the garage door has not closed, the garage module will send an open signal to the remote module so that the remote module will reactivate the visual indicator to alert a user that the garage door would not close. In preferred embodiments, the garage module is only capable of triggering the garage door opener to close the garage door. Accordingly, a user will not inadvertently be able to unknowingly and accidentally open the garage door with the remote module. It is to be appreciated, however, that in certain alternative embodiments that the ability to open a garage door from a remote can be incorporated into the system. Referring to block 645, the garage door module sends a “door closed” signal to the remote module after the garage door has closed, which causes the remote module to turn off its “open” visual indicator as indicated in block 640. If the remote module has a “closed” visual indicator, it is activated as well. If the garage door is not successfully closed, as might be the case when an object or other obstruction prevents the garage door opener from fully closing the garage door, the open visual indicator will continue to be activated. Further, with the one preferred embodiment incorporating a flashing LED during the closing operation, the LED will continue to flash if a “door closed” signal is not received thereby indicating to the user that he/she should considering investigating the reason why the door has not closed. Referring to block 655, the garage module will also send an “on” signal to an accessory module immediately after the associated garage door is opened. The signal is received by the optional accessory module, which as indicated in block 660 switches on typically to illuminate a lamp that is plugged into the module (or to turn on a light bulb screwed into an associated socket if the module is of the type illustrated in FIG. 5). It is appreciated that other appliances or electrically powered devices can be plugged into the accessory module to be automatically turned on when the garage door is opened; however, it is contemplated that a lamp would be the most likely item to be plugged into the accessory module to provide light in the building associated with the garage. Variations of the accessory module can also incorporate a photo sensor that measures the amount of light in the room in which it is resident. Accordingly, the accessory module can be configured not to switch the power on upon receipt of the “on” signal from the garage module when the room is not dark. After a suitable period of time has past, such as enough time for the user to enter the home and turn on other lights or travel to the desired part of the building, the garage module sends an “off” signal to the accessory module to switch the power supply to the lamp (or other AC-powered appliance) off as indicated in blocks 665 & 670. In one preferred embodiment, the time period in which the accessory module is switched on is about four minutes. The preferred embodiment may also be used to interface with intelligent X-10 automation controllers to allow garage door closure associated with events such as the time of day or the arming of a security system. This arrangement could also be used to trigger other complex external events based on the opening or closing of the garage door. Variations of the Preferred Embodiment Numerous variations of the described preferred embodiment are contemplated. For instance, although the system is described with reference to single garage, remote and accessory modules, multiple modules of any type can be utilized in any suitable configuration. For instance, two, three or more garage modules each connected to separate garage door opener relating to different bays in a multi-car garage can be used in the same system. Operationally, if anyone of the associated garage doors is open the particular garage module will send out an “open” signal to the remote modules. The “open” signals transmitted by any of the modules are identical and anyone will cause the door open visual indicator to be activated. Likewise when a door “close” signal is sent from any remote module, all the garage modules associated with an open door will activate the associated garage door openers to close the associated garage door. Also any number of remote modules can be used with the system. Accordingly, a user can place a remote module in any room he/she desires. Any door “open” signal sent by any garage module will cause the “door open” visual indicators of all the remote modules to activate. Likewise, a “close” signal from anyone of the remote modules will cause the garage module to activate the garage door opener. Finally, the “closed” from the garage module will cause all the remote modules to deactivate its “door open” visual indicator. Finally, any number of accessory modules can be utilized with the system. A user could have modules in different rooms of the house to light all or a significant portion of the house when the garage door is opened. All the accessory modules will switch on or off when a respective “on or “off signal is sent by the garage module. As can be appreciated, other variations of the system can include more than one module of each type, such that more than one garage module is utilized in conjunction with more than one remote module and more than one accessory module. An intelligent X-10 automation controller may also be utilized with the system to allow complex events to be associated with the opening or closing of the garage door(s). Alternative Embodiments The embodiments of the garage door monitoring and actuating system as illustrated in the accompanying Figures and described above are merely exemplary and are not meant to limit the scope of the invention. It is to be appreciated that numerous variations to the invention have been contemplated as would be obvious to one of ordinary skill in the art with the benefit of this disclosure. All variations of the invention that read upon the appended claims are intended and contemplated to be within the scope of the invention. While a particular signal transmission protocol has been described, other transmission protocols can be utilized instead as would be obvious to one of ordinary skill in the art. Further, different types of signals can be utilized other than those specifically described to accomplish similar results as the system described in detail herein. For instance, in a multiple garage module system, each module can have its unique signals such that a remote module can differentiate between the different garage modules. The remote module could also have separate visual indicators for each of the different garage modules. In another example, the garage module can periodically send a status signal to the remote module as to its current status (i.e. the garage door is open or closed) instead of sending signals only when (or within a predetermined period of time after) the garage door is either opened or closed. Likewise, the garage module can be programmed to differentiate between different accessory modules such that they are turned off after different respective periods of time as desired by the user. Further, in yet other embodiments the accessory modules may incorporate their own timer circuits, to turn off automatically after being turned on with having to receive an “off” signal from the garage module. While the preferred embodiments utilize signals transmitted over the power grid of a house or building, in alternative embodiments any suitable transmission means can be utilized including, but not limited to, wireless transmission and dedicated hard wiring. The modules may also vary significantly from those illustrated herein. For instance, in some variations the laser pointers can be omitted. In other variations, the garage module and its functionality can be integrated with a garage door opener. When integrated with a garage door opener, the garage door position sensor can be eliminated as the integrated device can utilize the garage door sensor of the opener instead. In yet other embodiments, a central controller can be provided to process all the signals and set up the operational protocols of the various modules. The central controller can comprise a personal computer with an appropriate interface. Accordingly, a user can determine and set the operational characteristics of the device (such as the various address and command codes, as well as, operational periods of time from a central location. | <SOH> BACKGROUND <EOH>Automatic garage door opening systems have become very popular in the past twenty years such that residences wherein a person has to manually open and close the garage door are the rare exception. The typical garage door opener system comprises an electric motor unit mechanically coupled to the garage door through an associated track mechanism, a wireless receiver electrically connected to an actuation switch circuit of the motor unit, one or more actuators mounted at convenient locations in the garage for opening and closing the garage door, and a wireless remote control device typically kept in a vehicle for opening and closing the garage door from within the vehicle. Almost universally, garage door opener systems also include a safety sensor that prevents the garage door from closing if a person or any object is in the path of the closing door. This safety feature prevents the garage door from injuring a child or a pet that might be in the door's path, and it also prevents the garage door from damaging inanimate objects, such as a vehicle that has not been fully pulled into the garage. Unfortunately, typical garage door opener systems have no way of alerting a user if the garage door has been left open unintentionally. Many users routinely push an actuator next to the door into their residence to close the garage door as they enter their residence. Commonly, the user does not wait to see if the door completely closes. Accordingly, if an object such as a child's toy is located in the path of the door, or the safety sensor is misaligned, the door with will not close and will automatically return to its fully open position. Additionally, many garage door opener users will for whatever reason just leave the garage door open and forget to close it before they retire for the evening. Many people keep valuable items in their garages such as power tools and bicycles that can be easily taken from the garage by nefarious individuals who pass by an open and tempting garage during the night when most if not all of the applicable residence's occupants and the occupants of neighboring residences are asleep. It is not uncommon for a homeowner to have something of value taken from their garages at some point in their lives because they mistakenly left the garage door open. Various remote monitoring systems are known that indicate to a person located in a remote location from the garage door, such as in a bedroom of the associated residence, whether or not the garage door is open. Examples of such systems are described in the following U.S. Pat. Nos. 6,597,291; 6,522,258; 6,184,787; 6,049,285; 6,166,634, 5,883,579; and 5,689,236. While the specifics of these systems vary, none of them provide any mechanism for closing the door from the remote location. Rather, the person noticing the signal from the device that the garage door is open has to get up, walk over to the garage door, and activate the garage door opener to close the garage door. This can be an inconvenience, especially when the room the person is coming from is on a second floor. Other systems are known that automatically close an open garage door without input of a person after the satisfaction of specific criteria. U.S. Pat. Nos. 4,463,292, 5,510,686, 5,752,343, 6,469,464, and 6,563,278 all teach systems that automatically closes a garage door after a set time interval. U.S. Pat. No. 5,752,343 also teaches a device that will close the door when it becomes dark. Unfortunately, if there is something blocking the door, the door will not shut and a person will have no idea the door was not in fact closed. Additionally, these devices have the potential to lock the owner out of their home if the door automatically closes while they are outside. | <SOH> SUMMARY <EOH>According to one embodiment of the invention, a garage door status monitoring and actuating system comprises a first garage module adapted to be coupled to a first garage door opener and to actuate the first garage door opener. The garage module includes a first transceiver. The system also includes (i) a first garage door position sensor adapted for being coupled with the first garage module, and (ii) a first remote module adapted to be located remotely from the first garage module within a building. The first remote module includes a second transceiver, a first indicator, and a first switch. Operationally, the first transceiver is adapted to send a first signal to the second transceiver when the garage door position sensor is in a first state. The first remote module is adapted to activate the first indicator upon receipt of the first signal. The second transceiver is adapted to send a second signal when the first switch is activated, and the first garage module is adapted to actuate the garage door opener upon receipt of the second signal. According to another embodiment of the invention, a garage door status monitoring and actuating system comprises a garage module that is electrically coupled with a garage door opener and an AC power grid of an associated building. The garage module includes a first transceiver adapted to transmit at least a first signal over the power grid and receive a second signal over the power grid. The garage module also includes a garage door position sensor that is mounted proximate a garage door. The garage door position sensor is coupled with the garage door module, the garage door position sensor has at least two states, a first state when the garage door is at least partially open and a second state when the garage door is completely closed. The system further includes a remote module electrically coupled with the AC power grid of the associated building. The remote module includes (i) a second transceiver adapted to transmit at least the second signal over the power grid and receive the first signal, (ii) a user actuatable switch, and (iii) a visual indicator. Operationally, the first signal is transmitted by the garage module when the garage position sensor moves into the first state. The remote module, upon receiving the first signal, activates the visual indicator to indicate the garage door is open. The remote module transmits the second signal when the switch is depressed, and the garage module, upon receiving the second signal, activates the garage door opener to close the garage door. According to yet another embodiment of the invention a method of operating a garage door status monitoring and actuating system is described. The method comprises in the provided order: (i) sending a first signal over an associated building's power grid from a garage module to a remote module; (ii) activating a visual indicator at the remote module indicating an associated garage door is open; (iii) sending a second signal over the associated building's power grid from the remote module to the garage module upon activating a switch on the remote module by the user; and (iv) activating the garage door opener to close the garage door after receiving the second signal. | 20040203 | 20060124 | 20050811 | 63726.0 | 0 | POPE, DARYL C | GARAGE DOOR REMOTE MONITORING AND ACTUATING SYSTEM | MICRO | 0 | ACCEPTED | 2,004 |
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10,770,779 | ACCEPTED | Equipment support for a metal building | A device for supporting equipment on a wall panel having protruding ribs. Channels are mounted perpendicular to the ribs. The channel has a base wall, and a pair of side walls extending outward from the base wall. The channel also has an outward wall portion communicating with the side walls at a distance from the base wall. Several apertures are defined in each channel. The apertures have a pair of side wall portions and a base wall portion. When the channel is positioned on the wall panel, the apertures receive the protruding ribs. A fastening structure is located on the base wall of the channel for mounting the channel to the wall panel. A fastening plate is also located on the outward wall portion of the channel for mounting the equipment to the channel. | 1. An apparatus, for supporting a piece of equipment on a wall panel having a plurality of protruding ribs, comprising: at least one channel adapted to be mounted substantially perpendicular to the ribs, wherein the channel has a base wall and a pair of side walls extending outward from opposite edges of the base wall; and a plurality of apertures defined in the channel adapted to receive the protruding ribs, wherein each of the apertures has a base wall portion in the base and a side wall portion in each side wall. 2. The apparatus of claim 1 wherein each side wall extends outward substantially perpendicular from the base wall. 3. The apparatus of claim 1, wherein each side wall has a lip spaced from the base wall. 4. The apparatus of claim 1, further comprising a fastener plate mounted to the channel between the side walls, wherein the fastener plate has a threaded aperture adapted to secure the equipment thereto. 5. The apparatus of claim 1, wherein the apertures are spaced apart from each other equal distances. 6. The apparatus of claim 1, wherein the base wall portion of each aperture is substantially rectangular. 7. The apparatus of claim 1, wherein the side wall portions of each aperture are hat-shaped, each of the side wall portions comprising two tapered edges and a flat crest edge. 8. In an improved building wall apparatus of the type having at least one panel and containing a plurality of vertically extending ribs, the improvement comprising: at least one channel having a flat base wall and a pair of parallel side walls extending outward from opposite edges of the base wall; a lip on each side wall spaced a distance from the base wall; a plurality of apertures defined in the channel adapted to receive the protruding ribs, each of the apertures having a base wall portion in the base and a side wall portion in each side wall; a fastener plate mounted to the channel between the side walls, the fastener plate having a threaded aperture adapted to secure the equipment thereto; and an electrical equipment box mounted to the channels by fasteners passing through the box into the fastener plate. 9. The apparatus of claim 8, wherein the base wall portion of each aperture is substantially rectangular. 10. The apparatus of claim 8, wherein the side wall portions of each aperture are hat-shaped, each of the side wall portions comprising two tapered edges and a flat crest edge. 11. The apparatus of claim 8, wherein the fastener plate is slideable longitudinally along the side walls. 12. The apparatus of claim 8, wherein the fastener plate is urged against the lips of the side walls by a spring. 13. The apparatus of claim 8, wherein the height and width of the side wall edges of the apertures are adapted to be greater than the height and width of the ribs protruding from the panel. 14. A method for mounting a piece of equipment to a wall panel having a plurality of protruding ribs, comprising: (a) providing a channel having a base wall, a pair of side walls extending outward from opposite edges of the base wall, and a plurality of apertures; (b) positioning the channel to be substantially perpendicular to the ribs; (c) positioning the apertures to be substantially aligned with the corresponding plurality of protruding ribs; (d) mounting the channel to the wall panel, and encasing the ribs within the edges of the apertures of the channel; and (e) mounting the equipment to the channel. 15. The method of claim 14, wherein step (a) comprises providing a plurality of apertures, each of the apertures having a base wall portion in the base and a side wall portion in each side wall. 16. The method of claim 14, wherein step (d) comprises mounting the base wall of the channel to the wall panel. 17. The method of claim 14, wherein step (a) comprises providing a fastener plate mounted to the channel between the side walls, and wherein step (e) comprises mounting the equipment to the fastener plate. 18. The method of claim 14, wherein step (a) comprises providing a lip on each side wall spaced from the base wall. 19. The method of claim 14, wherein step (c) comprises aligning the distance between the center of one aperture to the center of another aperture to be approximately equal to the distance between the center of one rib to the center of another rib. 20. The method of claim 14, wherein step (a) comprises providing the height and width of the side wall edges of the apertures to be greater than the height and width of the ribs protruding from the panel. | RELATED APPLICATIONS This patent application claims priority to U.S. Provisional Patent Application Ser. No. 60/486,116 filed on Jul. 10, 2003, which is incorporated by reference in its entirety. FIELD OF THE INVENTION This invention relates in general to brackets, and in particular to a slotted channel or brace that mounts to a metal building wall for holding electrical equipment. BACKGROUND OF THE INVENTION In the field of electrical contracting, it is often necessary for a piece of equipment, such as an electrical panel or a conduit, to be mounted to the outside of a metal building. However, problems arise in many cases where the equipment will not mount flush against the metal wall siding panel, because the metal siding includes vertical ribbing that protrudes from the wall. This vertical ribbing prevents flush mounting of the equipment, especially with respect to pieces of equipment having a substantial width. The problem similarly exists with respect to metal wall siding panels that have incremental ribs with varying degrees of protrusion from the wall. SUMMARY A need exists in the art for a device that will effectuate more sustainable mounting capabilities, while optimizing the mating surface area interfaced between the equipment and the surface on which it is mounted. One solution to this problem is a horizontal channel beam. The channel beam would feature grooves on one side corresponding to the protruding ribs, and would attach to the ribbed metal wall siding panel accordingly. The other side of the channel beam would feature an attachment mechanism to secure a piece of equipment to the channel beam, thus producing a successful mount of the piece of equipment to the ribbed wall. This invention describes a channel device for supporting a piece of equipment, such as an electrical panel or conduit, on a metal wall siding panel having several protruding ribs. The channel has a base wall, and a pair of side walls extending outward from the base wall. The channel also has an outward wall portion communicating with the side walls at a distance from the base wall. Several apertures are defined in the channel. The apertures have a pair of side wall edges that surround the perimeter of the protruding ribs, and a pair of base wall edges that are substantially parallel to the ribs. When the channel is positioned on the metal wall siding panel, the apertures are designed to receive the protruding ribs. Fastening structures exist on either side of the channel. A first fastening structure is located on the base wall of the channel for mounting the channel to the metal wall siding panel. A second fastening structure is located on the outward wall portion of the channel for mounting the equipment to the channel. The novel features of this invention, as well as the invention itself, will best be understood from the following drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial front view of a building having slotted channels constructed in accordance with this invention. FIG. 2 is an exploded sectional view of the building of FIG. 1 as shown along the line 2-2 of FIG. 1. FIG. 3 is an enlarged perspective view illustrating one of the channels of FIG. 1. FIG. 4 is a front view of a portion of the channel of FIG. 3. FIG. 5 is an enlarged view of the channel of FIG. 3, shown laid out flat prior to being bent into the rectangular configuration. DETAILED DESCRIPTION OF THE INVENTION Although the following detailed description contains many specific details for purposes of illustration, anyone of ordinary skill in the art will appreciate that many vairations and alterations to the following details are within the scope of the invention. Accordingly, the exemplary embodiment of the invention described below is set forth without any loss of generality to, and without imposing limitations thereon, the claimed invention. Referring to FIG. 1, a building with wall siding panels 11 is shown. Panels 11 have vertical ribs 13 extending parallel to each other and separated by flat base portions 14. Each panel 11 may be approximately 36″ wide, with the distance between ribs 13 being about 6″. Each rib 13 in this embodiment is generally in the shape of a hat channel with tapered sides and a flat crest. However, the configuration of ribs 13 could differ. Also, panels 11 may have smaller ribs located between larger ribs 13. Panels 11 are typically made of metal but could also be made of plastic. A pair of braces or slotted channels 15 are shown mounted horizontally to the exterior of wall siding 11. Channels 15 are parallel to each other and perpendicular to ribs 13. Channels 15 will provide support for a variety of equipment. In this embodiment, an electrical panel 17 is shown mounted to channels 15 on the exterior of wall siding 11. Also, by way of example, a wiring conduit 21 is shown secured to channels 15 by pipe clamps 23. Referring to FIG. 2, the metal building has vertical studs 25 spaced apart from each other. Studs 25 may be of a variety of configurations, and in this example are shown to be C-shaped in cross-section. Metal braces 27 typically extend horizontally between studs 25, perpendicular to them. Braces 27 are spaced apart from each other along the lengths of studs 25. Braces 27 are illustrated as being flat, but could have various cross-sectional shapes. Wall siding 11 secures to braces 27 by screws (not shown) that extend through flat base portions 14. Referring to FIG. 3, channels 15 may vary in configuration, but preferably comprise a rectangular channel member with the open side or slot facing outward. Channel 15 has a base wall 29 and two parallel side walls 31 that extend from base wall 29 orthogonally. Typically, the free edges of side walls 31 curve over to form lips 33. An open slot is located between lips 33. To accommodate the protruding ribs 13, a plurality of apertures 35 are formed in channel 15 at the same spacing as ribs 13. Each aperture 35 has a side wall portion 35a that extends partially through each side wall 31. Each side wall portion 35a is larger than the cross-sectional dimension of one of the ribs 13. In this embodiment, each side wall portion 35a is also hat-shaped, with two tapered edges and a flat crest edge, however they could be rectangular. The two side wall portions 35a are joined by a base aperture portion 35b. Base portion 35b is rectangular and has a width greater than the width of ribs 13. Apertures 35 enable channel 15 to be placed flat against wall panels 11, with the channel base wall 29 flush against the panel base portion 14, as shown in FIG. 2. Screws 38 extend through screw holes 37 and into wall panels 11 and braces 27. Apertures 35 are preferably formed during the manufacturing process for channels 15. Channels 15 are preferably formed by bending flat metal plate. As shown in FIG. 5, each aperture 35, including its two side wall portions 35a and base portion 35b, is cut as a single hole while the plate that forms channel 15 is still flat. This can be done by a punch or some other type of cutting operation. If desired, screw holes 37 could be also punched in base wall 29 to facilitate inserting screws 38 (FIG. 2) to fasten channels 15 to wall panels 11. The plate is bent along fold lines 39 before or after forming apertures 35 to form lips 33 (FIG. 3). After apertures 35 are formed, the plate is bent along fold lines 40 to the rectangular configuration of FIG. 3. In operation, the building will be constructed conventionally. Wall panels 11 will be installed on the exterior of braces 27. If it is desired to mount external equipment to panels 11, such as electrical panel 17 or conduit 21, channels 15 will be installed. This is done by aligning apertures 35 with ribs 13 and placing base wall 29 of channel 15 in contact with base portions 14 of siding 11. The operator inserts screws 38 to hold channels 15 in place. Equipment is attached to channels 15 conventionally. FIG. 3 illustrates one type of fastener to fasten panel 17 to channel 15. A spring 41 is urged against a nut plate 43, pushing nut plate 43 against lips 33. The user can slide nut plate 43 along the length of channel 15 to various positions. Nut plate 43 has a threaded hole 45 for receiving a screw. Screws extend through flanges or a back wall of electrical panel 17 (FIG. 1) into engagement with holes 45. Screws also pass through clamps 23 (FIG. 1) and engage other nut plates 43. Rather than nut plates 43, screws could protrude from plate 43. This invention offers several important advantages. It enables more sustainable mounting of wide pieces of equipment to a ribbed metal wall siding panel. Whereas in the past the protruding ribs prevented wide pieces of equipment from being mounted flush against the wall panel, this invention enables the wide pieces of equipment to be mounted on a long, flat, ribless channel surface that is in turn mounted to the wall panel. Furthermore, by virtue of the apertures created to receive the protruding ribs, the channels may now be manufactured with substantial ease and efficiency relative to past such attempts. The apertures also eliminate excess material from the channel itself, which conserves resources and provides for more a more lightweight structure. Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereupon without departing from the principle and scope of the invention. Accordingly, the scope of the present invention should be determined by the following claims and their appropriate legal equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>In the field of electrical contracting, it is often necessary for a piece of equipment, such as an electrical panel or a conduit, to be mounted to the outside of a metal building. However, problems arise in many cases where the equipment will not mount flush against the metal wall siding panel, because the metal siding includes vertical ribbing that protrudes from the wall. This vertical ribbing prevents flush mounting of the equipment, especially with respect to pieces of equipment having a substantial width. The problem similarly exists with respect to metal wall siding panels that have incremental ribs with varying degrees of protrusion from the wall. | <SOH> SUMMARY <EOH>A need exists in the art for a device that will effectuate more sustainable mounting capabilities, while optimizing the mating surface area interfaced between the equipment and the surface on which it is mounted. One solution to this problem is a horizontal channel beam. The channel beam would feature grooves on one side corresponding to the protruding ribs, and would attach to the ribbed metal wall siding panel accordingly. The other side of the channel beam would feature an attachment mechanism to secure a piece of equipment to the channel beam, thus producing a successful mount of the piece of equipment to the ribbed wall. This invention describes a channel device for supporting a piece of equipment, such as an electrical panel or conduit, on a metal wall siding panel having several protruding ribs. The channel has a base wall, and a pair of side walls extending outward from the base wall. The channel also has an outward wall portion communicating with the side walls at a distance from the base wall. Several apertures are defined in the channel. The apertures have a pair of side wall edges that surround the perimeter of the protruding ribs, and a pair of base wall edges that are substantially parallel to the ribs. When the channel is positioned on the metal wall siding panel, the apertures are designed to receive the protruding ribs. Fastening structures exist on either side of the channel. A first fastening structure is located on the base wall of the channel for mounting the channel to the metal wall siding panel. A second fastening structure is located on the outward wall portion of the channel for mounting the equipment to the channel. The novel features of this invention, as well as the invention itself, will best be understood from the following drawings and detailed description. | 20040203 | 20080115 | 20050113 | 58061.0 | 0 | MYERS, JEROME B | EQUIPMENT SUPPORT FOR A METAL BUILDING | SMALL | 0 | ACCEPTED | 2,004 |
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10,770,830 | ACCEPTED | Method for interferometric radar measurement | It is proposed in connection with a method for the interferometric radar measurement in conjunction with a helicopter operating in accordance with the ROSAR principle (Heli-Radar) that two coherent receiving antennas with receiving channels are associated with a transmitter of the ROSAR-system mounted on the revolving rotary cross; and that the difference (ΔR) between the two distances (R+ΔR, R) from the measured impact point P are calculated, in the manner known per se, based on the wavelength λ of the emitted radar signal and the measured phase difference of the receiving echo of the two coherent receive channels. | 1. An arrangement for interferometric radar measurement comprising: a transmitter disposed on a turnstile of a ROSAR system of a helicopter radar; at least two assigned coherent receiving antennas having receiving channels disposed on said turnstile of said ROSAR system of a helicopter radar; and an additional transmitting/receiving antenna disposed on said turnstile wherein said additional transmitting/receiving antenna has a narrow beam and is focused downward in elevation covering a lower range of a sight angle. 2. The arrangement for interferometric radar measurement according to claim 1, wherein said transmitter and said at least two assigned coherent receiving antennas are arranged at an end of said turnstile. 3. The arrangement for interferometric radar measurement according to claim 1, wherein said receiving antennas are positioned vertically over each other in a normal position of a helicopter. 4. A process for interferometric radar measurement comprising the steps of: assigning two coherent receiving antennas having receiving channels to a transmitter; calculating a path length difference of two distances to a measured receiving point from a wave length of a transmitted radar signal and of a measured phase difference of a reception echo of both coherent receiving channels; assigning said two coherent receiving antennas to a transmitter of a ROSAR system; arranging said two coherent receiving antennas and said transmitter on a rotating turnstile of a radar; and evaluating signals of an additional transmitting/receiving antenna that has a narrow beam and is for determination of said phase difference of said reception echo of both coherent receiving channels; wherein a helicopter operating according to the ROSAR principle is used for the interferometric radar measurement. 5. The method according to claim 4, further comprising a step of calculating coordinates of a respective receiving point using a sight angle for representing image points on an integrated graphic display screen in the ROSAR system. 6. The method according to claim 5, wherein said antenna and a center of an image on said graphic display screen are in a fixed relationship. | CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation in part application of U.S. patent application Ser. No. 09/889,759 filed on Jul. 20, 2001, incorporated herein by reference wherein priority is claimed under 35 U.S.C. 120, this application also claims priority under 35 U.S.C. §371 from PCT/DE99/04066 filed on Dec. 22, 1999, and also claims priority under 35 U.S.C. 119 from German Patent Application DE 199020078 filed on Jan. 21, 1999. BACKGROUND The invention relates to a method for interferometric radar measurements. Due to their construction, radar devices are precise range-finding systems, which means that without special measures, a radar device is capable of determining only the distance of a target from the antenna, but not its direction. It is possible to determine only whether a target is present within the lobe of the antenna. This problem is eliminated to a large extent in conjunction with the ROSAR or Heli-Radar system known until now by using, for example 16 vertically staggered antennas with an antenna opening angle of, for example 2.5°. It is possible with this type of a system to determine the location of an elevated obstruction etc. within an accuracy of about 2.5° in terms of elevation. However, in this case, targets located at the same distance are also displayed in the same antenna in the same image spot. The azimuthal resolution of the known Heli-Radar system amounts to about 0.2° because of a special signal processing. These features are taught in the disclosure in DE 39 22 086 C1. However, the direction of an obstruction and thus the location in space at which this obstruction is located can be determined only with the help of a triangulation, whereby in the simplest case, two locally separated radar installations can be used for this purpose. However, it is also possible to use the properties of a coherent radar system and to perform a triangulation with the help of the phase of the emitted signal. Thus, a coherent radar system is used which coherently transmits a signal via a transmitting antenna and receives the echoes scattered back via two locally separated receiving antennas. A coherent evaluation permits a calculation of the phase difference between receiving signals. The direction from which the scattered echoes are received is determined based on the phase difference. Now, once the distance and direction of an “obstruction” have been computed, its location in space can be determined as well. This type of three-dimensional determination of a location with the help of a coherent radar system which comprises one transmitting antenna and two receiving antennas is generally referred to as “radar interferometry” and known for a long time. It is used already for the generation of topographic charts with the help of SAR-systems installed on aircraft, for example by the DOSAR system of the firm Dornier GmbH. With these designs, reference is also made to the following published documents pertaining to the further state of the art: C. T. Allan, Review Article, Interferometric Synthetic Aperture Radar, in IEEE Geoscience and Remote Sensing Society News Letter, September 1995, p. 6 ff; S. Buckreuss, J. Moreira, H. Rinkel and G. Waller, Advanced SAR Interferometry Study, DLR Bulletin 94, Jun. 10, 1994, Institut für Hochfrequenztechnik, Oberpfaffenhofen. The entire prior art known to this date and the state of the art cited above, including the ROSAR principle on which the present invention is based, projects terrain elevations or other elevated obstructions in one plane, so that it is not possible to recognize the elevation of the given obstruction if the reproduced topography of the terrain present is unknown. However, a three-dimensional image is required for controlling flights. The present invention is based on the problem of proposing measures on the basis of the ROSAR principle that permit a quasi-three-dimensional image representation of terrain and other obstructions. SUMMARY The problem is solved with an arrangement for interferometric radar measurement having a transmitter and two assigned coherent receiving antennas with receiving channels. The transmitter and receiving antennas are arranged on the turnstile of the ROSAR system of a helicopter radar. An additional transmitting/receiving antenna is provided wherein this additional transmitting/receiving antenna is sharply focused in the elevation direction. The transmitter and receiving antennas are arranged at the end of the turnstile. The receiving antennas are also arranged at the end of the turnstile. The arrangement includes a process whereby two coherent receiving antennas with receiving channels are assigned to a first transmitter, and the path length difference of the two distances can be calculated to measured receiving point P from the wave length of the transmitted radar signal and of the measured phase difference of the reception echo of both coherent receiving channels. A helicopter operating according to the ROSAR principle is used for the interferometric radar measurement, whereby two coherent receiving antennas are assigned to a transmitter of the ROSAR system arranged on a rotating turnstile on the radar. Additionally, receiving signals of the sharply focused or second transmitting/receiving antenna can be evaluated for determination of the phase difference. The sight angle is used for calculating the coordinates of the respective receiving point for representing the image points on the integrated graphic display screen in the ROSAR system. The antennas and the center of the image on the graphic display screen are in a fixed relationship to each other. The first transmitter along with the two receiving antennas are used to determine the location of point P. However, this determination of the location of point P may contain inaccuracies or ambiguities because these two receiving antennas have a value of a measured phase difference that is ambiguous wherein this ambiguity can only be determined down to a value ranging between 0 and 2π. Therefore, this ambiguity must be determined by additional measurements. Thus to provide these additional measurements there is the additional or sharply focused transmitting and receiving antenna. This transmitting and receiving antenna is located in the end of the antenna cross and wherein this antenna has a narrow beam. This antenna covers the lower range of the sight angle. The distance to the impact point on the ground can be clearly determined by the receive echo of this additional transmitting/receiving antenna. Thus, this INROSAR-system accepts the distance as a basic value and calculates the further ambiguities based on the rising distance from the continuous phase transitions. Thus, this system is a system with a first antenna transmitter with two receiving antennas and then one additional transmitting and receiving antenna that is used to dispel any ambiguities of the signal received by the first antenna transmitter and receiver. BRIEF DESCRIPTION OF THE DRAWINGS Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings which disclose at least one embodiment of the present invention. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention. In the drawings, wherein similar reference characters denote similar elements throughout the several views: FIG. 1 shows a schematic representation of an exemplified embodiment with respect to the typical geometry for an interferometric ROSAR system; FIG. 2 shows a block diagram of the exemplified embodiment according to FIG. 1; FIG. 3 is a perspective view of the state of the art with respect to the ROSAR principle; FIG. 4 is a second embodiment of the invention which includes an additional antenna; and FIG. 5 is a block diagram of the electronic components associated with the design shown in FIG. 4. DETAILED DESCRIPTION According to the general idea of the invention, the goal is to obtain in conjunction with a helicopter operating according to the ROSAR-system a quasi-three-dimensional radar image representation for flight guidance by associating with a transmitter located on the rotating rotary cross two coherent receiving antennas with receiving channels. The ROSAR-system used heretofore is comprised of, for example 16 transmitters and receivers with their channels for obtaining a three-dimensional image. However, these transmitters and receivers have a directional inaccuracy of about 2.5°. Now, if said ROSAR-system, as mentioned above, is expanded by a highly precise coherent receiving channel, only one transmitter and two coherent receivers instead of the, for example sixteen transmitters and receivers employed until now will be required for obtaining the highly precise three-dimensional radar image. The directional inaccuracy found until now is enhanced by the interferometric principle by about a factor of 100. This is explained in the following description of an exemplified embodiment of the invention, which is sketched in FIG. 1. A helicopter operating according to the ROSAR principle flies over the surface of the earth at an altitude H. One transmitting antenna and two receiving antennas with associated coherent transmitting and receiving electronics are mounted on the end of the rotating antenna cross. The received echoes are amplified, digitized and processed further. The distance between this arrangement as described above, which is referred to in the following as the INROSAR-system, and the impact point P, which is located at a relative altitude h, is referred to as R. The distance from the antenna A1 of the INROSAR-system to the impact point P amounts to R+ΔR and is therefore by a small amount ΔR greater than the distance R to the antenna A2. The difference ΔR between the two distances can be calculated based on the known wavelength λ of the emitted radar signal and the measured phase difference φ of the receiving echo of the two coherent receiving channels. Impact point Q has a relative altitude lower than impact point P and is on the surface of the Earth E. Now, this phase difference φ of the receiving echo is in turn calculated based on the images generated by processing the receiving echo. Each of the two images is present in a complex, digital form, i.e. it comprises a real part and an imaginary part, or equivalent: the amplitude and the phase. Now, the phase difference φ follows up to a multiple of p (modulo p) through complex multiplication of the image points of the one image with the conjugated complex image points of the other image, and subsequent formation of the arctangent of the respective real and imaginary parts. The phase difference φ is obtained in this way, and by inserting φ in equation 1, ΔR is then obtained. Δ R = λ 4 π ΔΦ ( 1 ) The phase centers of the two receiving antennas A1 and A2 are removed by the length B, the so-called base line. The following results from the cosinus theorem and a few simple angle relations: cos ( θ ) = ( R + Δ R ) 2 - R 2 - B 2 2 · R · B ( 2 ) After the sight angle θ has been calculated in equation (2), it is now possible to determine the relative altitude h as follows: h=H−R·cos(θ) (3) The altitude h is actually not required in connection with the INROSAR system for representing the image points on the graphics display screen DS, but only the sight angle θ is used for calculating the coordinates of an impact point P on the integrated graphics display screen in the Rosar system. Furthermore, whether the angle of inclination of the antenna is known or not is unimportant as well because the representation on the display screen is only a relative representation of the image points with respect to the vertical line in relation to the base line B of the two antennas A1 and A2. The representation of the image is in fact dependent upon the position of the helicopter, for example due to the pitching. However, the antennas of the INROSAR-system and the center of the image are always in a fixed relation to each other. The altitude h and the angle of inclination α of the antennas are only required if a topographical chart with an absolute altitude H of the area over which the aircraft is passing is to be generated with the help of said INROSAR-system. The formulas specified above are useful also for a consideration of errors, as will be explained in the following. The errors relevant to the INROSAR-system are the phase noise df and the change in the base line B between the phase centers of the antennas A1 and A2. The phase noise is composed of the sum of proportions of the different components. The greatest contributions are supplied by the transmitter, the receivers, the system timer and the noise of the A/D-converter. A typical order of magnitude for the entire phase noise δφ of an INROSAR-system amounts to approximately 5°. The change in the base line between the phase centers of the antennas A1 and A2 may be caused, for example by heating due to the incidence of sunlight rays. 0.001 m is assumed to be a typical value. The various influences result in a scatter δh of the altitude of the impact point P and thus in a scatter of the sight angle δθ. δ h = λ · R 4 π · B δϕ ( 4 ) δ h = - R · tan ( θ ) δ B B ( 5 ) This results in scatter of the sight angle dθ as follows: δθ = arcsin ( δ h R ) ( 6 ) In conjunction with an exemplified embodiment according to FIG. 1, the helicopter flies in the normal position, which means that the antennas A1 and A2 are positioned vertically one on top of the other. ΔR is determined based on equation (1). The value of the measured phase difference Δφ of the echo from the antennas A1, and A2 is ambiguous and can be determined only down to a value ranging between 0 and 2π. This ambiguity of 2π has to be determined by means of additional measurements. Thus, as shown in FIG. 4 an extra transmitter/receiver A3 complementing the INROSAR conception comprising a transmitting/receiving antenna that has a narrow beam in elevation and covers the lower range of the sight angle can be used. The distance to the impact point on the ground can be clearly determined by the receive echo of this additional transmitting/receiving antenna. The INROSAR-system accepts the distance as a basic value and calculates the further ambiguities based on the rising distance from the continuous phase transitions. The following calculation example supplies the detailed explanations. The calculation is based on the situation that the helicopter flies in its normal position. This means that the antennas A1 and A2 are vertically arranged one on top of the other. The following parameters apply: Parameter Meaning Value 1/Value 2 H flight altitude of INROSAR 100 m R + ΔR Distance between impact point P and Example 1: 500.009 m antenna A1 Example 2: 500.09 m R Distance between impact point P and 500.00 m antenna A2 B Base line between the phase centers 0.15 m of the antennas δB Error of length of base line B 0.001 m δφ Phase noise of the INROSAR system 5° α Angle in inclination of antennas A1 90° (vertically) and A2 λ Radar wavelength 0.0090909 From equation (2) follows: θ = arccos ( ( R + Δ R ) 2 - R 2 - B 2 2 · R · B ) ( 7 ) EXAMPLE 1 θ1 = arccos ( ( 500.009 2 - 500.000 2 - 0.15 2 ) 2 · 500.000 · 0.15 ) = arccos ( 0.05985 ) = 86.57 ° h1 = 300 - 500.00 · cos ( 86.57 ° ) = 70.09 m EXAMPLE 2 θ1 = arccos ( ( 500.09 2 - 500.00 2 - 0.15 2 ) 2 · 500.000 · 0.15 ) = arccos ( 0.0599904 ) = 53.14 ° h1 = 300 - 500.00 · cos ( 53.14 ° ) = 0.048 m From the equations (4) and (5) follows for the scatter δh of the altitude h of the impact point P: δ h δϕ = 0.00909 · 500.00 4 · π · 0.15 ( 5 0 / 57.3 0 ) = 0.21 m exactly : 0.210401168 m δ h δ B = - 500.00 · tan ( 53.14 0 ) · 0.001 0.15 = 4.45 m - based on ( 2 ) : = 2.035 - 0.048 m This results in a scatter of the sight angle δθ as follows: Due to phase noise, δφ=5°: δθ = arcsin ( 0.21 500.00 ) = 0.02 ° ; and because of errors in the length of base line B by δB=0.001 m: δΦ = arcsin 4.45 500.00 = 0.5 ° . FIG. 2 shows a block diagram of the exemplified embodiment shown in FIG. 1. This block diagram is equipped with the components required for the proposed interferometric radar method and requires no further explanations for the expert in the field. However, the process is as follows, transmitting antenna T1 emits a signal that then reflects back as multiple signals including at least two received signals into Antennas A1 and A2 as signals Se1 and Se2 respectively. These signals are then fed into the electronic components as shown in FIG. 2. In addition, data of the height H0 is also fed into these electronic components. These signals Se1 and Se2 are fed or decoupled into demodulator 1 and 2 respectively wherein they are then converted from analog signals into a digital signals in Analog Digital converters 1 and 2 respectively. Next, the signals undergo a correction of movement errors via input from a kinematic sensor wherein this information is then fed into the respective memories 1 and 2. This information is then processed in a correlator with range curvature correction wherein it is then processed in an interferometry module and then printed to an associated display screen. FIG. 3 shows a display of a rotating cross having an antenna lobe which is used to emit and receive signals. The antenna lobe can contain the two antennas and one transmitter as shown in FIG. 1 or it can contain the two transmitters and one antenna in FIG. 4 which also includes the additional sharply focused antenna which includes an additional transmitter and receiver. As shown in FIG. 4 this additional sharply focused signal covers a lower region of the associated sight angle wherein as described above, this additional antenna A3 including an additional transmitter and receiver is disposed adjacent to the other antennas A1 and A2 and the associated other transmitter T1. This additional antenna is for correlating and calculating the different ambiguities of the received signals in antennas A1 and A2. The distance to the impact point on the ground can be clearly determined by the receive echo of this additional transmitting/receiving antenna. The INROSAR-system accepts the distance as a basic value and calculates the further ambiguities based on the rising distance from the continuous phase transitions. Finally, FIG. 5 shows the electronics design similar to that shown in FIG. 2 wherein this design includes the input from the additional antenna and receiver A3 for additional processing. For example, a coherent radar signal (See FIG. 4) is transmitted by one antenna A1 and then received by two coherent receiving antennas A1 and A2. The two coherent signals Se1 and Se2 are coherently demodulated in Demodulator 1 and Demodulator 2 and then converted from an analog signal to a digital signal in Analog to Digital converter (A/D) converter 1 and A/D converter 2 respectively. This information is then respectively fed into a system for the correction of movement errors. In addition, a kinematic sensor determines the movement of the helicopter (altitude and velocity) and feeds this information in the modules “Correction of Movement Errors 1 and 2”. These digital signals are then corrected and then written in Memory 1 and Memory 2. A separate narrow beamed transmit/receive antenna supplies a signal Se3 which is converted from analog to digital as well. In addition, in a distance module, an unambiguous distance D0 to the nearest illuminated point on the ground is determined. The distance D0 and the altitude H0 are supplied to the Geometry Module. This information is forwarded to the Depth of Focus Module and Distance Intervals Module. Both modules in combination with the Reference Functions Module calculate current valid reference functions. These reference functions are written to Memory 3. The Range curvature comparator module determines the actual range curvature from the current helicopter movement and altitude. The reference functions from memory 3 and the current range curvature are fed in to the respective modules “Correlation with Range Curvature Correction 1 and 2” and corrected to reflect the current helicopter movement and altitude. The radar signals from Memory 1 and Memory 2 are also fed into the respective modules “Correlation with Range Curvature Correction 1 and 2”. Here they are correlated with the reference functions to give two 2 dimensional images 1 and 2. The two respective images 1 and 2 are forwarded to the Interferometry Module, where the 3-dimensional image is calculated. The 3-dimensional image is transformed to a quasi-3 dimensional image so that it can be shown on a 2 dimensional display. Thus, with this additional signal Se3 is used to clarify any ambiguities associated with the measurement of the other two signals Se1 and Se2 that are read by antennas A1 and A2. Accordingly, while at least one embodiment of the present invention has been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention as defined in the appended claims. | <SOH> BACKGROUND <EOH>The invention relates to a method for interferometric radar measurements. Due to their construction, radar devices are precise range-finding systems, which means that without special measures, a radar device is capable of determining only the distance of a target from the antenna, but not its direction. It is possible to determine only whether a target is present within the lobe of the antenna. This problem is eliminated to a large extent in conjunction with the ROSAR or Heli-Radar system known until now by using, for example 16 vertically staggered antennas with an antenna opening angle of, for example 2.5°. It is possible with this type of a system to determine the location of an elevated obstruction etc. within an accuracy of about 2.5° in terms of elevation. However, in this case, targets located at the same distance are also displayed in the same antenna in the same image spot. The azimuthal resolution of the known Heli-Radar system amounts to about 0.2° because of a special signal processing. These features are taught in the disclosure in DE 39 22 086 C1. However, the direction of an obstruction and thus the location in space at which this obstruction is located can be determined only with the help of a triangulation, whereby in the simplest case, two locally separated radar installations can be used for this purpose. However, it is also possible to use the properties of a coherent radar system and to perform a triangulation with the help of the phase of the emitted signal. Thus, a coherent radar system is used which coherently transmits a signal via a transmitting antenna and receives the echoes scattered back via two locally separated receiving antennas. A coherent evaluation permits a calculation of the phase difference between receiving signals. The direction from which the scattered echoes are received is determined based on the phase difference. Now, once the distance and direction of an “obstruction” have been computed, its location in space can be determined as well. This type of three-dimensional determination of a location with the help of a coherent radar system which comprises one transmitting antenna and two receiving antennas is generally referred to as “radar interferometry” and known for a long time. It is used already for the generation of topographic charts with the help of SAR-systems installed on aircraft, for example by the DOSAR system of the firm Dornier GmbH. With these designs, reference is also made to the following published documents pertaining to the further state of the art: C. T. Allan, Review Article, Interferometric Synthetic Aperture Radar, in IEEE Geoscience and Remote Sensing Society News Letter, September 1995, p. 6 ff; S. Buckreuss, J. Moreira, H. Rinkel and G. Waller, Advanced SAR Interferometry Study, DLR Bulletin 94, Jun. 10, 1994, Institut für Hochfrequenztechnik, Oberpfaffenhofen. The entire prior art known to this date and the state of the art cited above, including the ROSAR principle on which the present invention is based, projects terrain elevations or other elevated obstructions in one plane, so that it is not possible to recognize the elevation of the given obstruction if the reproduced topography of the terrain present is unknown. However, a three-dimensional image is required for controlling flights. The present invention is based on the problem of proposing measures on the basis of the ROSAR principle that permit a quasi-three-dimensional image representation of terrain and other obstructions. | <SOH> SUMMARY <EOH>The problem is solved with an arrangement for interferometric radar measurement having a transmitter and two assigned coherent receiving antennas with receiving channels. The transmitter and receiving antennas are arranged on the turnstile of the ROSAR system of a helicopter radar. An additional transmitting/receiving antenna is provided wherein this additional transmitting/receiving antenna is sharply focused in the elevation direction. The transmitter and receiving antennas are arranged at the end of the turnstile. The receiving antennas are also arranged at the end of the turnstile. The arrangement includes a process whereby two coherent receiving antennas with receiving channels are assigned to a first transmitter, and the path length difference of the two distances can be calculated to measured receiving point P from the wave length of the transmitted radar signal and of the measured phase difference of the reception echo of both coherent receiving channels. A helicopter operating according to the ROSAR principle is used for the interferometric radar measurement, whereby two coherent receiving antennas are assigned to a transmitter of the ROSAR system arranged on a rotating turnstile on the radar. Additionally, receiving signals of the sharply focused or second transmitting/receiving antenna can be evaluated for determination of the phase difference. The sight angle is used for calculating the coordinates of the respective receiving point for representing the image points on the integrated graphic display screen in the ROSAR system. The antennas and the center of the image on the graphic display screen are in a fixed relationship to each other. The first transmitter along with the two receiving antennas are used to determine the location of point P. However, this determination of the location of point P may contain inaccuracies or ambiguities because these two receiving antennas have a value of a measured phase difference that is ambiguous wherein this ambiguity can only be determined down to a value ranging between 0 and 2π. Therefore, this ambiguity must be determined by additional measurements. Thus to provide these additional measurements there is the additional or sharply focused transmitting and receiving antenna. This transmitting and receiving antenna is located in the end of the antenna cross and wherein this antenna has a narrow beam. This antenna covers the lower range of the sight angle. The distance to the impact point on the ground can be clearly determined by the receive echo of this additional transmitting/receiving antenna. Thus, this INROSAR-system accepts the distance as a basic value and calculates the further ambiguities based on the rising distance from the continuous phase transitions. Thus, this system is a system with a first antenna transmitter with two receiving antennas and then one additional transmitting and receiving antenna that is used to dispel any ambiguities of the signal received by the first antenna transmitter and receiver. | 20040203 | 20060221 | 20050616 | 58376.0 | 0 | SOTOMAYOR, JOHN B | METHOD FOR INTERFEROMETRIC RADAR MEASUREMENT | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,770,841 | ACCEPTED | Asynchronous real-time retrieval of data | A data retrieval system includes a gateway server and an access client. The gateway server is communicatively connected to the access client through a network. The gateway server provides a presentation service (PS) and a real-time service (RTS), which cooperate with the access client to retrieve data from a data store and then provide the retrieved data to a user's remote communication device. More particularly, when a user wishes to retrieve data from the data store or to send data to the data store, the user establishes a communication connection between his or her remote communication device and the gateway server, and then requests the desired data from the gateway server. In response, the gateway server sends a command to the access client, instructing it to retrieve the requested data. The access client retrieves the requested data from the data store, and returns the retrieved data to the gateway server. The gateway server then relays the requested information back to the user's remote communication device. | 1. A gateway server, comprising: a presentation service that receives data requests from a user's remote communication device, the data requests requesting to send data to or receive data from a data store; and a real-time service that relays the data requests from the presentation service to a access client associated with the data store. 2. The gateway server recited in claim 1, wherein the presentation service includes a timer for determining a threshold time to return a reply to a data request to the user's remote communication device. 3. The gateway server recited in claim 2, wherein the presentation service further includes device characteristics corresponding to the user's remote communication device, and the threshold time is determined based upon the device characteristics. 4. The gateway server recited in claim 3, wherein the device characteristics specifically correspond to the user's remote communication device. 5. The method recited in claim 3, wherein the device characteristics correspond to a generic type for the user's remote communication device 6. The gateway server recited in claim 1, wherein the real-time service receives data requested in a data request, and relays the received data to the presentation service; and the presentation service forwards the received data to the user's remote communication device. 7. The gateway server recited in claim 6, wherein the presentation service further includes a cache for storing the received data. 8. The gateway server recited in claim 1, further including a directory identifying a connection between one or more access clients and the real-time service. 9. The gateway server recited in claim 1, wherein the data store includes a database. 10. The gateway server recited in claim 1, wherein the data store includes a server device that provides services to one or more client devices. 11. The gateway server recited in claim 1, wherein the data store is selected from the group consisting of: a Microsoft Exchange server, a Lotus Domino server, an IMAP mail store, a POP3 mail store, and a NTFS file system. 12. The gateway server recited in claim 1, wherein the presentation service receives the data requests from a user's remote communication device over a wireless network. 13. The gateway server recited in claim 1, wherein a timing of communications between the real-time service and the access client is independent of a timing of communications between the presentation service and the user's remote communication device. 14. The gateway server recited in claim 1, further comprising a directory storing an entry corresponding to the user's remote communication device and a connection between the real-time service and the access client, the entry identifying both the user and real-time service connected to the access client. 15. The gateway server recited in claim 1, wherein the gateway server provides access to email data, calendar data and directory data. 16. The gateway server recited in claim 1, wherein the data store resides behind a corporate firewall. 17. The gateway server recited in claim 1, wherein the access client associated with the data stored resides behind a corporate firewall. 18. The gateway server recited in claim 1, wherein the access client associated with the data store is a public email server. 19. A method of retrieving data from a data store, comprising: receiving a data request from a user's remote communication device at a presentation service, the data request requesting to send data to or receive data from a data store; providing the received data request to a real-time service; and relaying the data request from the real-time service to a access client associated with the data store. 20. The method recited in claim 19, further comprising: setting a timer upon receiving the data request; when the timer reaches a threshold value, determining whether data requested in the data request has been retrieved from the data store; and if the requested data has been retrieved, forwarding the requested data to the user's remote communication device, and if the requested data has not been retrieved, forwarding a message to the user's remote communication device instructing the user's remote communication device to resubmit the data request. 21. The method recited in claim 20, wherein the message causes the remote communication device to automatically resubmit the data request. 22. The method recited in claim 20, wherein the message prompts the user to resubmit the data request. 23. The method recited in claim 20, further comprising: before the timer reaches a threshold value, periodically determining whether data requested in the data request has been retrieved from the data store; and if the requested data has been retrieved, forwarding the requested data to the user's remote communication device. 24. The method recited in claim 20, further comprising determining device characteristics for the user's remote communication device; and setting the threshold value based upon the determined device characteristics. 25. The method recited in claim 24, wherein the device characteristics specifically correspond to the user's remote communication device. 26. The method recited in claim 24, wherein the device characteristics correspond to a generic type for the user's remote communication device. 27. The method recited in claim 19, further comprising receiving, at the real-time service, data retrieved from the data store by the access client in response to a data request; relaying the retrieved data from the real-time service to the presentation service; and forwarding the retrieved data from the presentation service to the user's remote communication device. 28. The method recited in claim 27, further comprising storing the retrieved data relayed from the real-time service in a cache provided by the presentation service before forwarding the retrieved data from the presentation service to the user's remote communication device. 29. The method recited in claim 19, further comprising receiving authentication information from the user's remote communication device at the presentation service. 30. The method recited in claim 19, further comprising creating an entry in a directory corresponding to the user's remote communication device and a connection between the real-time service and the access client, the entry identifying both the user and real-time service connected to the access client. 31. The method recited in claim 19, further comprising establishing a presentation session corresponding to the data request from a user's remote communication device. 32. The method recited in claim 31, wherein the presentation session is an entry in memory associating the user with a presentation session value. 33. The method recited in claim 31, wherein the presentation session identifies a location in memory at which data retrieved from the data store in response to the data request will be stored. 34. The method recited in claim 31, wherein the presentation session includes a flag indicating if data to be retrieved from the data store in response to the data request has been received and stored by the presentation service. 35. The method recited in claim 19, wherein relaying the data request from the real-time service to an access client associated with the data store includes: establishing a secure connection between the real-time service and the access client; providing the access client with encryption information over the secure connection; encrypting the data request with the encryption information; and relaying the encrypted data request to the access client. 36. The method recited in claim 35, wherein the secure connection is established using the Secure Sockets Layer protocol. 37. The method recited in claim 35, wherein the secure connection is established through a load balancer that receives communications for the presentation service. 38. The method recited in claim 35, wherein the encryption information includes a public encryption session identification and a private encryption key. 39. The method recited in claim 35, further comprising receiving, at the real-time service, data retrieved from the data store by the access client in response to a data request. 40. The method recited in claim 35, wherein receiving data retrieved from the data store by the access client in response to a data request includes: receiving the retrieved data from the access client over an unsecure connection, wherein the retrieved data has been encrypted using the encryption information; and decrypting the retrieved data using the encryption information. 41. A communications method, comprising: receiving a communication from a user's device at a first server; determining that the user's device corresponds to a client associated with a second server; and providing the user's device with a redirect command instructing the user's device to direct subsequent communications to the second server. 42. The communications method recited in claim 41, wherein determining that the user's device corresponds to a client associated with a second server includes checking a directory to identify the second server. 43. The communications method recited in claim 42, wherein the second server is identified in the directory by a directory entry that includes the user, the second server and the client. 44. The communications method recited in claim 41, wherein the redirect command is a cookie that is installed on the user's device. 45. The communications method recited in claim 41, further comprising: authenticating the user's device by the first server; creating authentication information for the authentication of the user's device by the first server; providing handoff information to the user's device, which handoff information includes the authentication information, such that the subsequent communications from the user's device to the second server can employ the authentication information. 46. The communications method recited in claim 45, wherein the handoff information further includes a time stamp. 47. The communications method recited in claim 45, wherein the handoff information includes a virtual address for the second server. 48. A communications method for communicating with a server, comprising: sending a first communication to a first server from a device corresponding to a client; in response, receiving a second communication from the first server, the second communication including redirect information identifying a second server; and transmitting subsequent communications from the device to the second server. 49. The communications method recited in claim 48, wherein the redirect information is a cookie that is installed on the device. 50. The communications method recited in claim 48, further comprising: authenticating the device with the first server; receiving handoff information from the first server, the handoff information including authentication information created by the authentication of the device with the first server; including the authentication information in a subsequent communication to the second server. 51. The communications method recited in claim 50, wherein the handoff information further includes a time stamp. 52. The communications method recited in claim 50, wherein the handoff information includes a virtual address for the second server. 53. A communications method for receiving communications from a user's remote communication device, comprising: receiving a communication from a user's remote communication device at a presentation service on a first server; determining that the user's remote communication device corresponds to a desktop access client associated with a real-time service on a second server; and providing the user's device with a redirect command instructing the user's device to direct subsequent communications to a second presentation service on the second server. 54. The communications method recited in claim 53, wherein the desktop access client is associated with a real-time service by a persistent, connection. 55. The communications method recited in claim 53, wherein determining that the user's remote communication device corresponds to the desktop access client associated with the real-time service on the second server includes checking a directory to identify the real-time service having an established connection with the desktop access client corresponding to the user's remote communication device. 56. The communications method recited in claim 53, wherein the second server is identified in the directory by a directory entry that includes the user, the second server and the desktop access client. 57. The communications method recited in claim 53, wherein the redirect command is a cookie that is installed on the user's remote communication device. 58. The communications method recited in claim 53, further comprising: authenticating the user's remote communication device by the presentation service on the first server; creating authentication information for the authentication of the user's remote communication device by the presentation device on the first server; providing handoff information to the user's remote communication device, which handoff information includes the authentication information, such that the subsequent communications from the user's remote communication device to the second presentation service on the second server can employ the authentication information. 59. The communications method recited in claim 58, wherein the handoff information further includes a time stamp. 60. The communications method recited in claim 58, wherein the handoff information includes a virtual address for the second server. | This application is a continuation-in-part of and claims priority under 35 U.S.C. § 119 to provisional U.S. Application Ser. No. 60/444,213, filed Jan. 31, 2003, entitled “Asynchronous Real-Time Retrieval Of Data,” which application is incorporated entirely herein by reference. FIELD OF THE INVENTION The present invention relates to the asynchronous real-time retrieval of data. Various aspects of the present invention are particularly applicable to the asynchronous real-time retrieval of data from a corporate database to a remote device, such as a wireless telephone or personal digital assistant. BACKGROUND OF THE INVENTION Recently, digital information has become more and more important to people of all walks of life. As the importance of digital information has increased, the need for convenient remote access to a variety of types of digital information has increased as well. For example, traveling businessmen may desire continual access to information contained in electronic spreadsheets, attorneys may desire access to word processing documents from a client's location, and students may want to send or retrieve electronic mail while in school. In order to address this need, many communication service providers allow their customers to access remote digital information through a communication network. For example, a wireless telephone service provider may allow its customers to use their wireless telephones or other communication devices to send and receive retrieve electronic mail, retrieve image information from a network, obtain contact information from a centralized database, or the like. Similarly, some companies have established remote high-speed Internet connections, both wired and wireless, at public locations such as restaurants, hotels, and airports, which can be accessed by a customer's computer. While communication service providers have created an infrastructure that potentially allows their customers remote access to digital information, many practical issues still prevent this infrastructure from being fully utilized. For example, some customers seek to access digital information stored behind a barrier, such as digital information stored in their employer's database and protected by a firewall. With this arrangement, if the employer's network did not support an access tool allowing external connections through the firewall then a customer would be prevented from accessing the desired digital information through the communication service provider's network. These access tools include, for example, the use of a virtual private network (VPN) or similar techniques for enabling secure and authenticated connections from devices not directly connected to the employer's network. Moreover, even if the employer's network supported such a tool, the customer's communication device could still not access the data if the user's device itself was not configured to support that tool. In other situations, a customer may attempt to use an unsuitable communication device to retrieve data. For example, a user may attempt to employ a personal digital assistant or wireless telephone with a relatively simple browser to retrieve a Web page with a large amount of image or audio data. Before the large amount of data can be fully retrieved, the personal digital assistant or wireless telephone may “time out” and sever the connection. Alternately or additionally, the user may seek to download more data than the personal digital assistant or wireless telephone may store. SUMMARY Advantageously, various examples of the invention allow a user to more conveniently send data to and retrieve data from a remote data store using a remote communication device. With different aspects of the invention, a data retrieval system includes an inbox (IB) server, referred to hereafter more generally as a “gateway server,” and a desktop access client (DAC), referred to hereafter more generally simply as an access client. The gateway server is communicatively connected to the access client through a network. The gateway server provides a presentation service (PS) and a real-time service (RTS), which cooperate with the access client to retrieve data from a data store and then provide the retrieved data to a user's remote communication device using a presentation protocol appropriate to the device's capabilities. With various implementations of the invention, the access client will create a connection to the gateway server. When the user wishes to retrieve data from the data store or to send data to the data store, the user establishes a communication connection between his or her remote communication device and the gateway server, and then requests the desired data from the gateway server. In response, the gateway server sends a command to the access client, instructing it to retrieve the requested data. The access client retrieves the requested data from the data store, and returns the retrieved data to the gateway server. The gateway server then relays the requested information back to the user's remote communication device through the presentation server using a presentation protocol appropriate to the device's capabilities. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a network environment including a system for asynchronous retrieval of data according to various embodiments of the invention. FIG. 2 illustrates an example of a computing system that may be used to implement various embodiments of the invention. FIGS. 3A-3D illustrate a flowchart showing a method for asynchronously retrieving data according to various embodiments of the invention. FIGS. 4A-4E illustrate a flowchart showing a method of retrieving data from a data store according to various embodiments of the invention. FIG. 5 illustrates a system for asynchronous retrieval of data employing multiple gateway servers according to various embodiments of the invention. DETAILED DESCRIPTION OF THE DRAWINGS Overview FIG. 1 shows a schematic block diagram of a data retrieval system 100 according to various embodiments of the invention. The retrieval system 100 allows for the retrieval of data, such as data from a corporate data store, to a remote device. As seen in this figure, the data retrieval system 100 includes at least one gateway (IB) server 101 and an access client (DAC) 103. In the illustrated example, the access client 103 is hosted by a user's computer 105. The computer 105 is located in, for example, a corporate network environment 107 that includes the data store 109 from which data is to be retrieved. The data store 109 may be any type of data store, such as a database that organizes data, a server device that provides services to one or more client devices or a combination of the two. The data store 109 may be, for example, a Lotus Domino server or a Microsoft Exchange server that manages a variety of data including electronic mail messages, calendar information, contact information and the like. The corporate network environment 107 may also include a firewall 111 or other barrier for preventing unwanted access to the corporate network environment 107. The data store 109 may also be a publicly available data store, such as, for example, a Yahoo email server or the like. Still further, the data store may be a generic IMAP or POP3 mail store, or even a store employing a desired file system, such as the NTFS file system. As shown in this figure, the gateway server 101 is communicatively connected to the access client 103 through a network 113, such as a wide-area network. The network 113 may be a publicly accessible network, such as the Internet. Alternately, the network may be a private network (often referred to as an intranet), or a combination of public and private networks. The gateway server 101 provides a presentation service (PS) 115 and a real-time service (RTS) 117, each of which will be explained in detail below. The presentation service 115 and the real-time service 117 of the gateway server 101 cooperate with the access client 103 to retrieve data from the data store 109 and then provide the retrieved data to the user's remote communication device 119. More particularly, the access client 103 creates a connection 121 (which may be, for example, a persistent connection) to the gateway server 101 through the firewall 111. The access client 103 then lies dormant until it receives commands from the gateway server 101 to retrieve data from the gateway server 101 or to provide data to the gateway server 101. When the user wishes to retrieve data from the data store 109 to the user's remote communication device 119 (or, alternately, to send data from the user's remote communication device 119 to the data store 109), the user establishes a communication connection 123 between the remote communication device 119 with the gateway server 101. Through the user's remote communication device 119, the user then requests the desired data from the gateway server 101. In response, the gateway server 101 sends a command over the connection 121 to the access client 103, instructing the access client 103 to retrieve the requested data. In response, the access client 103 retrieves the requested data from the data store 109, and returns the retrieved data to the gateway server 101. The gateway server 101 then relays the requested information back to the user's remote communication device 119. This process, together with the components of the system 100, will be discussed in more detail below. Operating Environment As will be appreciated by those of ordinary skill in the art, the gateway server 101 may be implemented using one or more computing devices, such as a programmable computer that may be programmed to send, retrieve and store the data files that make up electronic messages. This type of computer can be embodied by, for example, an electronic mail account server. FIG. 2 shows one example of such a programmable computer system 201 capable of retrieving and caching electronic mail data files from one or more outside electronic mail accounts. The computer system 201 includes a processing unit 203, a system memory 205, and a system bus 207 that couples various system components, including the system memory 105, to the processing unit 203. The system memory 205 may include a read-only memory (ROM) 209 and a random access memory (RAM) 211. A basic input/output system 213 (BIOS), containing the routines that help to transfer information between elements within the computer system 201, such as during startup, may be stored in the read-only memory (ROM) 209. If the computer system 201 is embodied by a personal computer, it may further include a hard disk drive 215 for reading from and writing to a hard disk (not shown), a magnetic disk drive 217 for reading from or writing to a removable magnetic disk (not shown), an optical disk drive 219 for reading from or writing to a removable optical disk (not shown) such as a CD-ROM or other optical media, or a memory card 221, such as a flash memory card. A number of program modules may be stored on the ROM 209, the hard disk drive 215, the magnetic disk drive 217, and the optical disk drive 219. A user may enter commands and information into the computer system 201 through an input device 223, such as a keyboard, a pointing device, a touch screen, a microphone, a joystick or any other suitable interface device. Of course, the computer system 201 may employ a variety of different input devices 223, as is known in the art. An output device 225, such as a monitor or other type of display device, is also included to convey information from the computer system 201 to the user. As will be appreciated by those of ordinary skill in the art, a variety of output devices 225, such as speakers and printers, may alternately or additionally be included in the computer system 201. In order to access electronic mail accounts, the computer system 201 preferably is capable of operating in a networked environment using logical connections to one or more remote computers, such as the remote computer 227. The computer system 201 may be connectable to the remote computer 227 through a local area network (LAN) 229 or a wide area network (WAN), such as the Internet. When used in a networking environment, the computer system 201 may be connected to the network through an interface 228, such as a wireless transceiver, a modem, an Ethernet connection, or any other suitable interface. While the interface 228 is illustrated as an internal interface in FIG. 2, it may alternately be an external interface as is well known in the art. Of course, it will be appreciated that the network connections described above are exemplary, and other means of establishing a communications link with other computers may be used. Use of the Presentation Service and the Real-Time Service With various embodiments of the invention, the data retrieved from the data store 109 may be requested and received over a wide area network, such as the Internet. This type of communication medium is relatively unpredictable, however, and the existing level of traffic over the network may affect the speed at which the real-time service 117 receives requested data. Further, a request for data from the user's remote communication device 119 will not typically specify the size of the requested data. For example, a user may employ the remote communication device 119 to request his or her most recent email message from the data store 109 without knowing the size of the message. Accordingly, when the presentation service 115 receives a request for data from the user's remote communication device 119, the presentation service 115 typically cannot ascertain when it will receive the requested data from the access client 103. This uncertainty presents a problem in that the presentation service 115 cannot determine in advance how long to maintain the connection 123 to the user's remote communication device 119. Typically, the remote communication device 119 will maintain an idle connection for only a preset time period before severing the connection. Thus, in some situations, the time between when the presentation service 115 requests the data from the real-time service 117 and when the presentation service 115 receives the requested data in reply may be longer than the amount of time that the user's remote communication device 119 will wait for a reply from the presentation service 115 before severing the connection 123. In addition, the communications network supporting the communication device also may implement timeout procedures that are configured separately and independently from either the remote communications device 119 or the gateway server 101. These procedures may be used by communications service providers to prevent idle connections from consuming network resources that might otherwise be allocated to active connections. Thus, the communications network itself may timeout and sever the connection 123 to the gateway server 101 before a reply from the presentation service 115 has been received. Moreover, different types of remote communication devices 119 will have different waiting periods before severing an idle connection (that is, a connection where data is not being exchanged). More particularly, some types of remote communication devices 119 may employ a relatively sophisticated communication software application that will maintain an idle connection for several minutes. For example, if the remote communication device 119 is a laptop personal computer, it may use a version of the Microsoft Internet Explorer browser to communicate with the presentation service 115. This type of communication software application is typically configured to receive rich data with graphics and colors, and thus will wait a relatively long time for a reply from the presentation service 115 before “timing out” and severing the connection 123. On the other hand, a less sophisticated remote communication device 119 may employ a communication software application intended to receive only very simple data and that will only briefly maintain an idle connection. For example, a wireless telephone may communicate with the presentation service 115 using a streamlined browser that receives only text data and is designed to be navigated with a keypad. This type of simply communication software application will typically wait only a relatively short period of time for a reply from the presentation service 115 before timing out and severing the connection 123. To address this discrepancy between different types of remote communication devices 119 and their different supporting communications networks, the gateway server 101 according to various embodiments of the invention may employ both the presentation service 115 and the real-time service 117. More particularly, with various embodiments of the invention, the real-time service 117 maintains the connection 121, which may be a persistent connection, to the access client 103. The presentation service 115 then manages the connection 123 with various remote communication devices 119 through various communications networks. Thus, the presentation service 115 and the real-time service 117 cooperate together to provide asynchronous retrieval of data from the data store 109 to the user's remote communication device 119. That is, the timing of communications between the real-time service 117 and the data store 109 (through the access client 103) is independent of the timing of communications between the presentation service 115 and a user's remote communication device 119. According to various embodiments of the invention, the connection 121, the connection 123, or both may be encrypted. For example, the connection 121, the connection 123, or both may be encrypted using the Secure Sockets Layer (SSL) protocol. The encryption may be on a connection-by-connection basis. Thus, the connection 121 may be encrypted using one set of encryption information shared between the access client 103 and the real-time service 117, while the connection 123 may be encrypted using another set of encryption information shared between the user's remote communication device 119 and the presentation service 115. Alternately, with various embodiments of the invention, the connections 121 and 123 may be commonly encrypted “end-to-end,” using encryption information shared between the user's remove communication device 119 and the access client 103. Asynchronous Retrieval of Data Referring now to FIGS. 3A-3D, these figures illustrate a flowchart for one process that may occur according to various embodiments of the invention when the user desires to send data to or retrieve data from the data store 109. As shown in FIG. 3A, in order to employ the system 100, a user first installs the access client 103 on a computer that has access to the data store 109 (that is, on the computer 105) in step 301. For example, if the data store 109 is a Microsoft Exchange server that manages the user's electronic mail messages, the user will install the access client 103 on a computer that has access to the user's electronic mail account on the data store 109. As part of the installation process for some embodiments of the invention, the user may submit authentication information. This authentication information then later can be used to authenticate the user's identity when the user attempts to retrieve data to or send data from the user's remote communication device 119. In many situations, the user will employ the system 100 to send or receive electronic mail messages or other data from a data store 109 maintained by the user's employer. Accordingly, the data store 109 is illustrated in FIG. 1 as being within a corporate network environment 107, which may be behind the firewall 111, as previously noted. In these situations, the computer 105 may be the user's personal work computer that is also within the corporate network environment 107 and behind the firewall 111, and thus has easy access to the data store 109. It should be appreciated, however, that various embodiments of the invention may be employed to retrieve data from or send data to a data store 109 located within any computing environment. Also, any computing device having the desired access to the data store 109 may serve as the computer 105. Further, as will be explained in detail below, a user may employ multiple access clients 103 on different computers 105 to retrieve data from or send data to the data store 109, and multiple users may employ a shared access client 103 on a single computer 105 to retrieve data from or send data to the data store 109. It should be appreciated that, while the access client 103 is described in the illustrated embodiment as a client hosted on a single computer 105, various alternate embodiments of the invention may employ any configuration for the access client 103. For example, the access client 103 may itself be implemented by a “server” computer that servers other computers in a network. Thus, the access client 103 may provide access to the data store 109 for more than one user. Further, the access client 103 may provide centralized management and administration tools that enable a system administrator (e.g., a system administrator for the data store 109) to manage and control utilization of the access client 109 by individual users by e.g., selecting them from a directory or company address list. Moreover, the access client 103 may thus be implemented on a server that performs other functions, which may or may not be related to the operation of the access client 103. For example, the access client 103 may be implemented on a public email server, such as a Yahoo or Hotmail email server, or on a private email server. Still further, with different embodiments of the invention, the operation of the access client 103 may be distributed among a plurality of computers 105. Returning now to FIG. 3A, once the access client 103 has been installed on the computer 105 in step 301, the access client 103 establishes a secure communication connection to the gateway server 101 in step 303. More particularly, the access client 103 establishes a secure connection 121 with the real-time service 117 hosted by the gateway server 101. An entry for the connection, referred to as a real-time session, also is created in the directory 127. The directory 127 may be, for example, an Oracle database or other suitable database, or a Novell directory or other suitable directory. The entry for the connection 121 identifies both the user and the gateway server 101 hosting the real-time service 117 to which the connection 121 is made. According to various embodiments of the invention, the connection 121 may be a persistent connection that is maintained as long as both the access client 103 and the real-time service 117 are operating to provide service to a user. With still other embodiments of the invention, however, the connection 121 may be established on an as-instructed or periodic basis. Thus, various embodiments of the invention may employ heuristics to determine when the access client 103 establishes the connection 121 with the real-time service 117. These heuristics may determine, for example, that the access client 103 will connect every minute (or some other time period) if it services a user (or users) who have not frequently retrieved data from the data store 109. These heuristics may also determine that the access client 103 will persistently maintain connection 121 if it services a user (or users) who have frequently retrieved data from the data store 109. Still further, various embodiments of the invention may employ these heuristics only under certain conditions, such as when network traffic for the network carrying the connection 121 increases above a threshold level, or when the real-time service 117 reaches some threshold of simultaneous connections 121 with multiple access clients 103. In order to subsequently retrieve data from the data store 109 to the user's remote communication device 119 (or to send data from the user's remote communication device 119 to the data store 109), the user connects to the gateway server 101 through the user's remote communication device 119 in step 305. More particularly, the user establishes the communication connection 123 from the user's remote communication device 119 to the presentation service 115 hosted by the gateway server 101. As will be appreciated by those of ordinary skill in the art, in addition to personally initiating a connection with the gateway server 101 and requesting data from the data store 109, one or more software applications running on the user's remote communication device 119 may also initiate the connection 123 to the presentation service 115 hosted by gateway server 101 on the user's behalf. Depending upon the purpose and needs of the particular software application, the software application can initiate the connection 123 on a periodic, scheduled, or event-driven basis and make one or more data requests asking to retrieve data from or sending data to the data store 109. This approach relieves the user of the need to pro-actively initiate all connections and data requests or transfers and greatly improves the overall user experience. In the embodiment illustrated in FIG. 1, the user's remote communication device 119 is a wireless communication device that exchanges data or voice information over a wide-area wireless telephone communication network 125. For example, the user's remote communication device 119 may be a wireless telephone, or a personal digital assistant (PDA) or portable computer equipped with a wireless communication unit, such as a PCMCIA card like the Sierra Wireless AirCard®. With still other embodiments of the invention, however, the user's remote communication device 119 may be connected to the gateway server 101 through any suitable connection, including a public communication network such as the Internet. For example, the user's remote communication device 119 may alternately be connected to the gateway server 101 using a wired connection, such as a conventional “dial-up” or DSL telephone connection, a high-speed broadband connection provided by a cable television service provider, or even an optical connection. Further, the user's remote communication device 119 may be connected to the gateway server 101 through another communication device, such as a public Internet kiosk. Thus, rather than connecting to the gateway server 101 over the wireless network 125, the user's remote communication device 119 may connect to the gateway server 101 over any suitable medium, including a wireless communication network, a wired communication network or a composite wired and wireless communication network. Similarly, the connection 121 between the access client 103 and the real-time service 117 can be made over any suitable medium. In the illustrated embodiment, the connection 121 is established over a public, wide-area communication network, such as the Internet. With alternate embodiments of the invention, however, the connection 121 may be the established over, for example, a private communication network, such as a private wireless telephone communication network. Thus, the connection 121 also may be established over a wireless communication network, a wired communication network, or a composite wired/wireless communication network. As will be appreciated by those of ordinary skill in the art, a variety of communication techniques and protocols have been developed for exchanging data between devices. For example, communications over both high and low bandwidth connections may be made using well-known extensible markup language protocols, such as the Hypertext Markup Language (HTML) protocol, the Extensible Markup Language (XML) or the Synchronization Markup Language (SyncML) or other messaging-centric protocols such as the Post Office Protocol (POP) or the Internet Message Access Protocol (IMAP). Similarly, communications over lower-bandwidth wireless connections (such as wireless telephone connections) may be made using the well-known Wireless Markup Language (WML) protocol. Any suitable protocol, including any of these known protocols, may be used to exchange data between the remote communication device 119 and the presentation service 115, and between the access client 103 and the real-time service 117. Thus, communications over the connection 121 between the access client 103 and the gateway server 101 may be made using HTML or XML pages, while communications over the connection 123 between the user's remote communication device 119 and the gateway server 101 may be made using HTML, XML, SyncML, or WML pages, or other protocols including, but not limited to, IMAP and POP3. Because the equipment and procedures for communicating data between devices using these protocols are well-known in the art, they will not be described in further detail here. Returning now to FIG. 3A, the user authenticates his or her identity for the presentation service 115 in step 307. For example, the presentation service 115 may transmit one or more authentication inquiries to the user's remote communication device 119. These inquiries, which may be contained on a single markup language page, may ask the user for a username and password. In response, the user transmits the requested authentication information back to the presentation service 115. Of course, the user's remote communication device 119 may alternately or additionally provide one or more software applications for managing and presenting data, which includes user interface elements for collecting, storing, and submitting authentication information to the presentation service 115 without requiring the user to manually reenter the authentication information for each session with the presentation service 115. When the user wishes to retrieve data from the data store 109, the user sends a request for the desired data over the connection 123 to the presentation service 115 in step 309. For example, the user may request the header information for the most recent 10 electronic mail messages in the user's electronic mail account on the data store 109. This request can be made using any suitable technique. For example, once the user's remote communication device 119 has established the connection 123 with the presentation service 115, the presentation service 115 may transmit WML pages with prompts to the user's remote communication device 119. These pages may, for example, contain a list of possible information that can be requested by the user. After the user selects the prompts corresponding to the desired information, the selected prompts are transmitted back to the presentation service 115 as a request for the desired data. Of course, still other techniques for retrieved desired information from the data store 109 may be employed, including techniques where data is retrieved automatically by an application on the remote communication device 119 without requiring the user's intervention, as previously noted. In step 311, the presentation service 115 establishes a presentation session for the connection 123 with the user's remote communication device 119. The presentation service 115 thus associates all subsequent communications related to the request for the desired data with the user's remote communication device 119. For example, the presentation session may be an entry in memory, such as a data table, associating the user's username and password with a presentation session value. The presentation session may also identify a location in memory, cache 1151, at which the desired data will be stored upon retrieval, and a flag indicating if the desired data as been stored to the cache 1151. The use of the presentation session to retrieve data from the data store 109 to the remote communication device 119 will be discussed in further detail below. In step 313, the presentation service 115 checks to see if the desired information has already been cached in the cache 1151. As will be discussed in detail below, if the presentation service 115 determines that it already has cached the desired information then, in step 315, the presentation service 115 immediately retrieves the desired information from the cache 1151 and returns the desired information to the user's remote communication device 119. When the request for the desired data is initially made to the presentation service 115, however, the desired data probably will not have already been cached by the presentation service 115. Accordingly, when the desired data is not currently in the cache 1151, a request for the desired data is sent from the presentation service 115 to the real-time service 117 in step 317. In response, the real-time service 117 issues a command over the connection 121 to the access client 103 in step 319, instructing the access client 103 to retrieve the desired information from the data store 109. Upon receiving the command from the real-time service 117, the access client 103 retrieves the desired data from the data store 109 in step 321. Then, in step 323, the access client 103 returns the retrieved data to the real-time service 117, which in turn provides the retrieved data to the presentation service 115 in step 325. The presentation service 115 then stores the retrieved data in the cache 1151 in step 327. In step 329, the presentation service 115 determines if the request for the data is still pending from the user's remote communication device 119. That is, the presentation service 115 determines if the user's remote communication device 119 is still maintaining the connection 123 in wait for the desired data. If the request is still pending, then the retrieved data is provided to the user's remote communication device 119 in step 331. Thus, if the desired data can be retrieved by the gateway server 101 from the data store 109 within the idle time of the user's remote communication device 119, then the desired data can be immediately provided to the user. In many situations, however, the gateway server 101 will not be able to retrieve the desired data before the idle time for the user's remote communication device 119 expires and the user's remote communication device 119 terminates the connection 123. As will be discussed in more detail below, the presentation service 115 addresses these situations by responding to the user's remote communication device 119 before its idle time expires. More particularly, if the desired data is not retrieved before the user's remote communication device 119 terminates the connection 123, then the presentation service 115 will send a message to the user's remote communication device 119 instructing the user (or the user's remote communication device 119) to resubmit the request for the desired data. This response may be repeated until the desired data is retrieved from the data store 109 and stored in the cache 1151. By using the presentations session to associate these subsequent requests with the initial request for the desired data, the desired data can be transmitted to the user's remote communication device 119 once it has been stored in the cache 1151. That is, the desired data stored in the cache 1151 can be transmitted to the user's remote communication device 119 in response to an existing request for the data (i.e., over the existing connection 123) or when the request is resubmitted to the presentation service 115. Accordingly, desired data can be retrieved from the data store 109 on a real-time basis, regardless of the disparity between the idle time of the user's remote communication device 119 and the time required to obtain the desired data from the data store 109. Communication with the Remote Communication Device As previously noted, the presentation service 115 manages communications with the user's remote communication device 119, to ensure that the user's remote communication device 119 does not time out without receiving a reply to its request for data. FIGS. 4A-4E illustrate a flowchart showing one method that may be employed by the presentation service 115 according to various embodiments of the invention to reliably communicate with the user's remote communication device 119. As previously noted, in step 309 of the flowchart shown in FIGS. 3A-3D, the user sends the presentation service 115 a request for desired data from the data store 109. In step 401, the presentation service 115 determines if the request is a new request for the desired data, or if it is a resubmission of an earlier request for the desired data. If the request is a new request for the desired data, the presentation service 115 creates a presentation session in step 403, and then passes the request along to the real-time service 117 to retrieve the desired data from the data store 109. According to various embodiments of the invention, the process of creating the presentation session in step 403 includes designating the cache 1151 to be used for caching information relating to the request for the desired data from the user's remote communication device 119. As will be appreciated by those of ordinary skill, the presentation service 115 may employ any memory resource available to the gateway server 101. Because the requested data will be stored in the cache 1151 for immediate transmission to the user's remote communication device 119, however, a memory resource that can be quickly accessed to provide the requested data to the user's remote communication device 119 may conveniently be used for the cache 1151. With various embodiments of the invention, the cache 1151 may be encrypted or unencrypted. The process of creating the presentation session in step 401 also includes designating identification information identifying the presentation session. This identification information is then provided to the real-time service 117 with the request for the desired information. When the real-time service 117 then returns the retrieved data retrieved from the data store 109, it also provides the corresponding presentation session identification information. Using this returned presentation session identification information, the presentation service 115 stores the retrieved data in the cache 1151 associated with the presentation session. It should be appreciated that any suitable identification information may be used to identify the presentation session for the data request. For example, the identification information may be a specific code or password. Alternately, with some embodiments of the invention, the identification information may be the memory address of the location of the cache 1151 for the presentation session. In step 405, the presentation service 115 also initiates a timer 1153 for the user's remote communication device 119 corresponding to the presentation session. As will be discussed in more detail below, the timer 1153 will be used to predict when the user's remote communication device 119 will time out and sever the connection 123 to the presentation service 115. Further, in step 407, the presentation service 115 determines device type information for the device 119 that has requested the data. That is, the presentation service 115 determines information about the type of device making the request that will allow the presentation service 115 to identify operational characteristics for the user's remote communication device 119. With some implementations of the invention, the presentation service 115 may determine only a general category into which the user's remote communication device 119 can be classified. For example, with some embodiments of the invention, the presentation service 115 may determine whether the user's remote communication device 119 is employing WML, HTML, SyncML, IMAP or POP or the like to communicate. If the user's remote communication device 119 is using HTML, the presentation service 115 then determines if the user's remote communication device 119 is a personal computer or a personal digital assistant (PDA). Thus, if the user is employing, for example, a Toshiba PocketPC® PDA device to access the presentation service 115, the presentation service 115 may categorize that device as a personal digital assistant HTML device. Still other embodiments of the invention, however, may determine different or more detailed information regarding the user's remote communication device 119. For example, with some embodiments of the invention, the presentation service 115 may determine the specific browser (or other communication software) being used by the user's remote communication device 119 to communicate with the presentation service 115, particular settings for that communication software, or any other information that might be useful to determine how the user's remote communication device 119 will communicate with the presentation service 115. With some embodiments of the invention, this device type information may conventionally be provided by the user's remote communication device 119 when it initiates the connection 123. For example, if the user's remote communication device 119 sends a request for data using an HTML page, that page may conventionally include information that the presentation service 115 can use to determine the type of browser that the user's remote communication device 119 is employing to communicate with the presentation service 115. Alternate embodiments of the invention, however, may employ alternate techniques to provide the device type information to the presentation service 115. For example, with some implementations of the invention, the user may specify the device type information for the user's remote communication device 119 when the user installs the access client 103 on the computer 105. Alternately or additionally, the user may specify the device type information using a survey or questionnaire page (such as a HTML page) provided to the access client 103 or to the user's remote communication device 119. Once the user has specified the device type information with the questionnaire page, the gateway server 101 may generate and place a cookie on the user's remote communication device 119. When the user then employs the user's remote communication device 119 to request data from the presentation service 115 thereafter, the presentation service 115 can solicit the device type information from the cookie on the user's remote communication device 119 in reply. Of course, still other techniques for determining the device type information will be apparent to those of ordinary skill in the art, and may be used with various embodiments of the invention. Once the presentation service 115 has determined the device type information for the user's remote communication device 119 in step 407, the presentation service 115 employs that device type information to determine the communication characteristics of the user's remote communication device 119 in step 409. Among various communication characteristics that may be identified by the presentation service 115, the presentation service 115 determines how long the user's remote communication device 119 will wait for a reply to the request from the presentation service 115 before severing the connection 123. That is, the presentation service 115 uses the device type information for the user's remote communication device 119 to determine the idle time of the user's remote communication device 119. For example, as previously noted, with the illustrated embodiment of the invention the presentation service 115 may determine if the user's remote communication device 119 is using WML or HTML to communicate and, if the user's remote communication device 119 is using HTML, whether the user's remote communication device 119 is a personal computer or a personal digital assistant. If the presentation service 115 determines that the user's remote communication device 119 is using WML to communicate, then the remote device 119 is probably a wireless telephone using a simple browser software application. Accordingly, the presentation service 115 may determine that the user's remote communication device 119 will only wait a small period of time (for example, 5 seconds) after submitting the request to receive a reply from the presentation service 115 before severing the connection 123. On the other hand, if the user's remote communication device 119 is a personal computer employing HTML to communicate, then the user's remote communication device 119 is probably using a sophisticated browser software application, such as Microsoft Internet Explorer. The presentation service 115 may therefore determine that the user's remote communication device 119 will wait for a relatively long period of time (for example, two minutes) to receive a reply from the presentation service 115 before severing the connection. Various embodiments of the invention may employ different types of device type information to determine the device communication characteristics, as explained in detail above. Accordingly, different embodiments of the invention may also determine different types of device communication characteristics from the device type information. For example, if the presentation service 115 employs device type information that only identifies the user's remote communication device 119 as one of three broad categories of devices (e.g., a WML device, an HTML personal digital assistant device or an HTML personal computer device), then the presentation service 115 may correspondingly identify only one of three broad types of device communication characteristics. For example, it may determine that all WML devices will wait only 5 seconds for a reply, all HTML personal digital assistant devices will wait only 90 seconds for a reply, and that all HTML personal computer devices will wait only 2 minutes for a reply, regardless of the specific configuration of any particular device. If, however, the presentation service 115 employs more detailed device type information, such as the particular browser being used by the remote communication device 119, then the presentation service 115 may correspondingly employ more specific device communication characteristics information. For example, the presentation service 115 may determine that a device 119 using the Microsoft Internet Explorer, Version 6.0, will wait only three minutes for a reply from the presentation service 115 before severing the connection 123, while a device using a Sony-Ericsson browser for wireless GSM telephones will wait only 45 seconds for a reply from the presentation service 115 before severing the connection 123. As will be apparent to those of ordinary skill in the art, the level of detail of the device characteristics information may depend upon the level of detail of the device type information obtained by the presentation service 115. With various embodiments of the invention, the presentation service 115 may obtain the device characteristics information from, for example, a look-up table such as the device characteristics table 1155. The table 1155 may be populated using any conventional technique. For example, the device characteristics in the table 1155 may be populated when the server is initialized. Alternately, the gateway server 101 may populate the table 1155 by seeking the appropriate device characteristics information from a remote source, such as, for example, the Internet, for each new type of remote communication device 119 that is employed by a user. In the illustrated embodiment, the table 1155 is a component of the presentation service 115, in order to allow the presentation service 115 to more quickly retrieve the device characteristics information. Alternate embodiments of the invention, however, may have the table 1155 located in the real-time service 117, an independent database directly or indirectly accessible by the presentation service 115, or even in the access client 103. Still other embodiments of the invention may employ other techniques to determine the device characteristics information. For example, if the user's remote communication device 119 provides a cookie to the presentation service 115 with the device type information, as discussed above, this cookie may also include the device characteristics information for the device 119. Further, with various embodiments of the invention, the use of the device information to determine the device characteristics information may be omitted entirely. Instead, for example, with these embodiments of the invention the user's remote communication device 119 may provide the appropriate device characteristics information directly to the presentation service 115 when making a request for data. It should also be appreciated that, in addition to the idle time for the user's remote communication device 119, the device characteristics information may include other data as desired. For example, the device characteristics information may identify a particular data format employed by the user's remote communication device 119, a transmission speed for transmitting the retrieved data to the user's remote communication device 119, or other useful information corresponding to the device type of the user's remote communication device 119. Returning now to FIG. 4B, when the presentation service 115 has determined the device characteristics for the user's remote communication device 119, the presentation service 115 sets a threshold for the timer 1153 in step 411 using the determined device characteristic information for the user's remote communication device 119. More particularly, the presentation service 115 sets a value for the timer 1153 at which the presentation service 115 will generate and send a reply to the request for data from the user's remote communication device 119. The threshold value is selected to allow the presentation service 115 time to reply to the user's remote communication device's request for data before the user's remote communication device 119 times out and severs the connection 123. As will be appreciated by those of ordinary skill in the art, the specific threshold set for a timer 115 can be predicated upon a variety of factors, including the amount of time necessary to prepare and send a suitable reply. Thus, if a device 119 is using a sophisticated browser that requires a complex reply (including, for example, graphics), then the threshold may be set to allow more time for a reply than when the user's remote communication device 119 is using a simple browser that requires only a text reply. For example, if the presentation service 115 has determined that the user's remote communication device 119 is using a simple browser and will wait only 5 seconds for a reply before severing the connection 123, then the presentation service 115 may set the threshold for the timer 1153 to be 3 seconds, allowing 2 seconds to generate and send the reply message. If, however, the presentation service 115 has determined that the user's remote communication device 119 is using a sophisticated browser and will wait two minutes for a reply before severing the connection 123, then the presentation service 115 may set the threshold for the timer 1153 to be 1 minute, 50 seconds, thereby allowing more time (i.e., 10 seconds) to prepare and send a more complex reply before the user's remote communication device 119 times out and severs the connection 123. With various embodiments of the invention, still other factors can be taken into account when determining the threshold value for the time 1153, including, for example, current traffic conditions for the network 125 and the degree of reliability desired for the connection 123. Alternately, a single threshold value can be designated for each category of device type. Thus, for example, all communication devices 119 using WML may have a first threshold value for the timer 1153, all communication devices 119 that are HTML-using personal digital assistant devices can have a second threshold value for the timer 1153, and all communication devices 119 that are HTML-using personal computers can have a third threshold value for the timer 1153. Of course, with still other embodiments of the invention, a single time period can be used to determine the timer threshold value for all types of communication devices 119, regardless of their individual device communication characteristics. For example, the timer threshold value can be set for all types of devices so that the presentation service 115 employs only a single time period for all types of devices. With these embodiments of the invention, the determination of both the device type information and the corresponding device characteristics information may be omitted. It should also be noted that, while steps 401-411 have been described above as being in a specific order, other embodiments of the invention may order these steps in any desired manner. For example, some embodiments of the invention may set the threshold value and initiate the timer 1153 before relaying the request for data to the real-time service 117. Alternately, some embodiments of the invention may relay the request for data to the real-time service 117 before determining the threshold value and initiating the timer 1153. Still further, with some embodiments of the invention, the presentation service 115 may set the threshold value for the timer 1153 before initiating the timer 1153, while, with still other embodiments of the invention, the timer 1153 can be started before the threshold value for the timer 1153 is determined. Moreover, for example, with some embodiments of the invention, the presentation service 115 may designate the cache 1151 after the request for data has been relayed to the real-time service 117, before the request for data has been relayed to the real-time service 117, before the timer 1153 has been set, or after the timer 1153 has been set. In any case, once the threshold value for the timer 1153 has been set and the request for data relayed to the real-time service 117, the presentation service 115 then monitors the real-time service 117 in step 413 for a reply containing the retrieved data and the identification information identifying the presentation session corresponding to the request for the retrieved data. If a reply is not received, then in step 415 the presentation service 115 determines if the timer 1153 has reached its threshold value. If the timer 1153 has not reached its threshold value, then the presentation service 115 continues to monitors the real-time service 117 for a reply with the requested data. If, however, the timer 1153 has reached its threshold value, then the presentation service 115 sends a reply to the user's remote communication device 119 in step 417, indicating that the desired data has not yet been retrieved from the data store 109. More particularly, when the presentation service 115 determines that the threshold value has been reached, it formulates and sends a reply to the user's remote communication device 119 indicating that the desired data has not yet been retrieved. It should be appreciated that any suitable type of reply message may be employed by various embodiments of the invention. For example, with some embodiments of the invention, the reply message may be a page (such as an HTML or WML page) that displays a message to the user stating that the desired data has not yet been retrieved. With some embodiments of the invention, the reply message may additionally prompt the user to manually resubmit the request for the desired data. Thus, the reply message may display an invitation to the user to resubmit the request, along with a command prompt to resubmit the request. When the user activates the command prompt, associated software code in the reply page will instruct the user's remote communication device 119 to resubmit the request. Such automatic reply operations are well known, and thus will not be discussed in further detail. With still other embodiments of the invention, however, the reply message may simply include software instructing the user's remote communication device 119 to automatically resubmit the request of the desired data. With these embodiments of the invention, the reply message may thus omit displaying a message to the user. For various embodiments of the invention, the reply message will also include presentation session identification data identifying the presentation session associated with the request. This presentation session identification information may be the same presentation session identification information provided to the real-time service 117, or it may be different from the presentation session identification information provided to the real-time service 117. Also, while the presentation session information provided to the user's remote communication device 119 may conveniently be transmitted with the reply message, it may also be transmitted in a separate communication. For example, the presentation session identification may be provided to the user's remote communication device 119 immediately after the user's remote communication device 119 has submitted an initial request for desired information. In any case, when the user's remote communication device 119 resubmits the request for the desired information, the resubmitted request includes the presentation session information associated with the initial request for the desired data. Thus, when the resubmitted request is received by the presentation service 115, the presentation service 115 determines that the request matches an existing presentation session in step 401. The presentation service 115 then proceeds immediately to step 413 to determine if the desired data has been retrieved from the data store 109 and stored in the cache 1151. If the desired data has been retrieved and cached in cache 1151, then the desired data is immediately returned to the user's remote communication device 119, as noted above. If, however, the desired data has still not been cached in the cache 1151, then the process of steps 401 and 413-417 are repeated until the desired data is retrieved from the data store 109, stored in the cache 1151, and then provided to the user's remote communication device 119 in step 419. It should be noted that, with the illustrated embodiment, the presentation service 115 translates the retrieved data into a format that can be processed by the user's remote communication device 119 before transmitting the retrieved data to the user's remote communication device 119. It should also be appreciated, however, that this translation can be made at any point. For example, with some embodiments of the invention, the retrieved data can be translated into an appropriate format before it is stored in the cache 1151, while with other embodiments of the invention the retrieved data may be translated into an appropriate format just before it is transmitted to the user's remote communication device 119. With still other embodiments of the invention, however, the requested data may alternately or additionally be translated by the access client 103, the real-time service 117, the data store 109 or even the user's remote communication device 119 itself. Still further, the translation may even be performed by a combination of these components (including the presentation service 115). The request for data may thus be submitted and resubmitted by the user's remote communication device 119 until the desired data is retrieved from the data store 109 by the real-time service 117 and stored in the cache 1151. If there is an error in retrieving the desired data, then the real-time service 117 may generate an error message informing the user's remote communication device 119 that the data cannot be retrieved. With some embodiments of the invention, this error message may be stored in the cache 1151 instead of the desired data. When the user's remote communication device 119 then retrieves data from the cache 1151, it will retrieve the error message informing the user that the desired data could not be successfully retrieved from the data store 109. Still other embodiments of the invention, however, may relay the error message immediately after receiving the error message from the real-time service 117. With some embodiments of the invention, the presentation service 115, the real-time service 117, or both may “pre-fetch” data from the data store 109. Thus, various embodiments of the invention may employ heuristics to predict how much data a user will request from the data store 109 base upon, e.g., the user's previous pattern of data retrieval. For example, some users will frequently retrieve new email messages from their email account. For such a user, the presentation service 115 (or the real-time service 117) may independently periodically request all new email messages for the user from the data store 109. Accordingly, when the user employs the remote communication device 119 to retrieve his or her new email messages, that data will already be stored in the cache 1151. Still other users, however, may only occasionally request new email messages. For these users, the presentation service 115 (or the real-time service 117) may not independently request new email messages from the data store 109. Similarly, some users will regularly request particular combinations of data. For example, some users will typically request retrieval of an email message, and then immediately request retrieval of any attachments to retrieved email messages. With these users, the presentation service 115 (or the real-time service 117) may independently request attachment data with any requests to retrieve new email messages for the user from the data store 109. Accordingly, when such a user then follows a request to retrieve a new email message with a request to retrieve attachment data for the retrieved email message, that attachment data will already be stored in the cache 1151. Of course, various embodiments of the invention may employ further heuristics instead of or in addition to heuristics relating to retrieval frequency or the type of data retrieved. Such heuristics may include, for example, the level of service subscribed to by a user, the size of the data typically retrieved, or any other desired heuristics evaluation. Also, in addition to storing independently retrieved data in the cache 1151, various embodiments of the invention may also go ahead and forward the independently retrieved data to the remote communication device 119 without receiving an express request to retrieve that data. Communication with the Access Client As previously noted, the real-time service 117 retrieves the desired data from the data store 109 through the access client 103. More particularly, when the real-time service 117 receives a request for data from the presentation service 115, it relays that request to the access client 103. Because the access client 103 is hosted on the computer 105 that has access to the data store 109, the access client 103 can instruct the computer 105 to retrieve the desired data from the data store 109. When the computer 105 has obtained the desired data from the data store 109, the access client 103 returns the desired data to the real-time service 117. With some embodiments of the invention, the real-time service 117 may communicate with the access client 103 using conventional communication techniques available to the computer 105, to thereby establish the connection 121. In some situations, however, the computer 105 will be located in an environment shielded from unauthorized access by a barrier, such as the firewall 111 illustrated in FIG. 1. In these situations, the barrier may prevent many types of conventional two-way communication between the computer 105 (and thus the access client 103) and the real-time service 117. With these embodiments of the invention, the real-time service 117 and the access client 103 may communicate using any suitable communication technique, such as the use of a virtual private network (VPN). In some situations, however, even if the barrier can be configured to allow for conventional two-way communication between the computer 105 and the real-time service 117, the process of reconfiguring the barrier may be onerous, particularly if a large number of users are employing different computers 105 to retrieve data from a remote communication device. Accordingly, with various embodiments of the invention the real-time service 117 may employ a connection to the access client 103 through the network 113 that will pass through the firewall. As will be appreciated by those of ordinary skill in the art, various firewall systems will typically allow one or more specific access points by which a computer, such as the computer 105, may receive data from sources outside of the firewall. For example, conventional firewalls typically designate a port (sometimes identified as Port 80) through which a computer may receive data from outside sources. The real-time service 117 according to various embodiments of the invention may thus use such an access port to employ a one-way communication connection with the access client 103 through this type of designated port. Using this one-way communication connection, hereafter referred to as the command channel, the real-time service 117 may send instructions to the access client 103. More particularly, the real-time service 117 may send instructions commanding the access client 103 to retrieve and relay information, such as the desired information, back to the real-time service 117. It also should be noted that the real-time service 117 may use the one-way command channel to instruct the access client 103 to retrieve information from a location other than the data source 109 as well. For example, a user may wish to add information, such as a new electronic mail message, to the data store 109 for storage or action. Upon receiving the new data from the user's remote communication device 119, the presentation service 115 (through the real-time service 117) may then instruct the access client 103 to retrieve the new data from the real-time service 117 for delivery to the data store 109. Thus, with various embodiments of the invention, the command channel may be used only to send commands from the gateway server 101 to the access client 103. Because a command typically will be an instruction to take some action (e.g., retrieve headers for the first ten messages in the electronic mail folder “inbox” of the user, retrieve today's appointments from the electronic calendar for the user, perform a search for the text “Mike” in the electronic mail folder “contacts” of the user, etc.), the commands will usually be relatively small (e.g., less than 1 kB). As a result of their small size, multiple commands can be multiplexed on the command channel. In turn, the access client 103 can send data associated with the command to the real-time service 117 (or retrieve data associated with the command from the real-time service 117) over one or more alternate connections, collectively referred to hereafter as data channels. For example, the commands may include a specific address to which the associated data should be posted (or from which the associated data should be retrieved). The command may also include a parameter that can subsequently be used by the access client 103 to identify that its response (either posting or retrieving data) is a reply to that specific command. Using this information, the access client 103 may then post data to the specified address (or retrieve data from the specified address) through a different socket from the socket used by the command channel. Similarly, the access client 103 may also post various commands to the real-time service 117. These commands may, for example, relate to the authorization of additional users for the access client 103. Thus, a reply to a command from the real-time service 117 will not interfere with the access client's receipt of new commands from the real-time service 117, or with the transmission of data associated with responses to earlier commands. Advantageously, this arrangement improves the performance by allowing data channels to be established on as-needed basis directly to the physical server currently serving the user's device Together, the command channel and the data channels provide the connection 121 that allows two-way communication between the real-time service 117 and the access client 103 through a barrier such as a firewall. For example, the real-time service 117 may command the access client 103 to retrieve the desired data from the data store 109, and then post the retrieved data, along with the presentation session identification information corresponding to the request, back to a specific address. The address may be a universal resource location (URL) address for a location maintained by the real-time service 117, thereby allowing the real-time service 117 to retrieve the desired data from the access client 103. The instructions (or a preceding or subsequent instruction) may also command the access client 103 to take some action with respect to the new data, such as storing the new data in the data store 109 or sending the new data to another location. As previously noted, when the access client 103 establishes the persistent connection 121 with the real-time service 117, the real-time service 117 creates a real-time session for that connection. The real-time session may be, for example, a data object containing any desired data about the user and the connection, such as the port of the computer 105 through which the connection 121 is established. With some embodiments of the invention, the real-time session may be stored in the directory 127. Alternately, the real-time session may be stored in another suitable memory location. For various embodiments of the invention, a proxy service may be employed between the access client 103 and the real-time service 117 (e.g., in the public wide area network 113). With this type of arrangement, the proxy service may close the connection 121 on its own accord after a predetermined amount of time without an exchange of data over the connection. Alternately or addition, other problems could occur relating to the proxy service, causing it to sever the connection 121. It would therefore be beneficial for the access client 103 to be able to detect when the connection 121 is severed, so that it can reestablish the connection 121. Conventional application programming interfaces for network communications, however, such as conventional application programming interfaces for communicating using TCP/IP, are typically not convenient for providing an application feedback when a network connection suddenly closes. Moreover, the real-time service 117 will not necessarily know that the connection 121 has been severed until, for example, it tries to write to the socket through which the connection 121 was established. Accordingly, with various examples of the invention, the real-time service 117 may regularly send “heartbeat” messages to the access client 103. These heartbeats may be, for example, small groups of data packets that can be sent to continually maintain the one-way connection between the real-time service 117 and the access client 103. By periodically trying to send these heartbeats, the real-time service 117 can immediately detect when the connection 121 has been severed. Thus, by maintaining a continuous connection between the real-time service 117 and the access client 103, the real-time service 117 will be prepared to immediately process requests for desired data from the user's remote communication device 119 without having to initiate a new command channel for each new request. With some embodiments of the invention, the heartbeat may include data indicating to the access client 103 when the next heartbeat from the real-time service 117 should be received. If the access client 103 then does not receive the next heartbeat within the indicated time period (and any additional buffer period, as desired), then the access client 103 can conclude that the connection 121 is severed and needs to be reestablished. Also, because the heartbeat is generated by the real-time service 117, the time value indicating the rate of the heartbeat can be controlled by the real-time service 117. More particularly, the rate data for the heartbeats can be adjusted by the real-time service 117 based upon, for example, the amount of traffic being handled by the gateway server 101. Thus, the heartbeat is dynamically schedulable. For some implementations of the invention, the scheduled rate of the heartbeat may be the same for every connection 121. Alternate embodiments of the invention, however, may have two separate intervals for heartbeats. More particularly, some embodiments of the invention may have one heartbeat rate for active presentation sessions where a user is presently using a communication device 119 to communicate with the gateway server 101, and another heartbeat rate for inactive sessions. This arrangement can provide a quicker connection error detection time for sessions where a user will notice when the connection 121 is erroneously severed, and a less resource intensive connection error detection time where a user will not immediately notice when the connection 121 has been erroneously severed. Multiple Use of the Access Client While the use of the access client 103 was described above with reference to a single access client 103 accessing the data store 109, various embodiments of the invention may have multiple access clients 103 communicating with the gateway server 101. That is, each of a plurality of users can maintain an access client 103 communication with the gateway server 101. Moreover, a user can employ multiple access clients 103 to communicate with the gateway server 101. Additionally, various embodiments of the invention may allow a single access client 103 to service more than one user. For example, with these embodiments, when a user installs the access client 103 on the computer 105, the access client 103 may inquire as to whether the user wants to delegate remote access to the user's data in the data store 109 through anyone else (i.e., another user employing a different access client 103). If the user would like the ability to access desired data in the data store 109 through another user's access client 103, then the access client 103 may facilitate that arrangement. For example, if the access client 103 is being employed in a corporate network environment as illustrated in FIG. 1, the access client 103 may provide the user with a list of other persons having access to the corporate data store 109 (e.g., everyone in a corporate email server). When the user selects another person from the list, the access client 103 may, e.g., arrange for the selected person to receive an email reporting his or her selection (along with instructions on how to obtain and install an access client 103, if necessary). The user's access client 103 may also convey an encrypted message to the selected person, either by electronic mail or by another transmission technique. The encrypted message contains the information necessary to obtain the user's access to the data store 109. Thus, if the selected person agrees to provide access to the data store 109 for the user, the selected person's access client 103 can employ the access information contained in the encrypted message to obtain the user's access to the data store 109. Advantageously, with some of the embodiments of the invention described above that employ a one-way command channel, the one-way command channel can service multiple users of the access client 103. More particularly, commands corresponding to different users may be multiplexed over the single command channel. With this arrangement, when the access client 103 establishes the connection 121 with the real-time service 117, it identifies the users that it is serving to the real-time service 117. Use of Multiple Gateway Servers While the previous discussion described the user of only a single gateway server 101 for ease of understanding, many implementations of the invention would employ multiple gateway servers 101, as shown in FIG. 5, to both increase capacity and redundancy. For example, some embodiments of the invention may employ gateway servers 101 in an N+1 architecture, including as many gateway servers 101 as needed for a desired capacity, plus an extra gateway server 101 for redundancy. A conventional N-tier Web service system may typically have between one and four tiers, depending upon the purpose of the service. For example, a conventional Web service system may include a first-tier Web server, a second-tier application server, and then a third-tier database server. In general, a user may access such a Web service system by presenting the Web server tier with a request, which then flows to the application server, and onto the database server in a vertical manner. This type of conventional network will often include one or more load balancers that route incoming requests based upon the current use of each server (i.e., the load balancer will route incoming requests to servers that are less occupied). With various embodiments of the invention, however, each user has at least one access client 103 installed on a computer 105, which in turn establishes a persistent connection to a gateway server 101. Thus, when a user employs a remote communication device 119 to transmit a request to the data retrieval system 100′, it would be more efficient to specifically route the request to the gateway server 101 that has already established a persistent connection 121 to the user's access client 103. Advantageously, various implementations of the invention may conveniently match a user's incoming request to send or retrieve data with the user's access client 103. As noted above, when an access client 103 connects with a real-time service 117, the real-time service 117 creates a real-time session for that connection. While a real-time session exists for a persistent connection 121, it may exist across multiple requests from remote communication devices 119. That is, when a request from a remote communication device 119 is received by the presentation service 115, it can be mapped through a real-time session to the real-time service 117 maintaining the connection 121 to the user's access client 103. Moreover, each time that the request is subsequently received from the remote communication device 119, it can again be mapped back to the proper real-time service 117 through the real-time session. Thus, these embodiments of the invention provide a collocation process to collocate a user's presentation session, maintained by a presentation service 115, with the user's real-time session corresponding to the persistent connection established between the user's access client 103 and a real-time service 117. Referring now to FIG. 5, with collocation, when an access client 103A is turned on, it negotiates a secure connection to a real-time service 117 provided by a gateway server (e.g., the real-time service 117A provided by gateway server 101A). In the process of establishing this connection, information pertaining to the connection is stored in the directory 127. For example, when a user USER1 employs the access client 103A, the real-time service 117 may note that USER1 has established a connection from the access client 103A to gateway server 101A (or to real-time service 117A). It should be noted that, with some embodiments of the invention, a user may delegate his or access to a data store (e.g., data store 109A in FIG. 5) to multiple access clients 103 as described above. If a user thereby is associated with connections to multiple real-time services 117, then suitable heuristics may be employed to select one connection to a gateway server 101 that is preferable to the others for the purpose of collocating a presentation session with a real-time session. When a user subsequently employs a remote communication device 119 to, e.g., submit a request for data from the data store 109, the presentation service 115 receiving the request will initially authenticate the request, as discussed in detail above. For example, as previously noted, the presentation service 115 may provide the user's remote communication device 119 with an authentication user interface requesting the user's name, password, etc. Once the remote communication device 119 (i.e., the user) has been authenticated, the presentation service 115 makes a query to its associated real-time service 117, which in turn queries the directory 127 as to the gateway server 101 (or, alternately, the real-time service 117) corresponding to the user. More specifically, the real-time service 117 may query to the directory 127 whether the user has established an existing connection 121 between an access client 103 and a gateway server 101, and if such a connection 121 currently exists, which gateway server 101 is maintaining the connection 121. If, for example, a request for data from USER1 is initially routed to gateway server 101B, by querying the directory 127 the gateway server 101B can determine that the user's access client 103 is currently connected to the gateway server 101A (i.e., to the real-time service 117A). Based upon this information, the presentation service 115B generates a redirect response for the remote communication device 119. The redirect response may be device specific, but may not require any special software. Instead, the response may be, for example, a conventional HTML, WML or HDML redirect command. The redirect response then causes the remote communication device 119 to issue its subsequent requests for the desired data specifically to the gateway server 10A. More particularly, the redirect response may, for example, provide the remote communication device 119 with software instructions, such an HTTP “cookie.” These software instructions contain routing information (or, alternately, are themselves routing information) to be included in subsequent submissions of the request for the desired data. Accordingly, when the remote communication device 119 resubmits a request for desired information, the routing information can be used to route the request directly to the presentation service 115 associated with the real-time service 117 maintaining a connection to the user's access client 103. For example, as shown in FIG. 5, a data retrieval system 100′ according to various implementations of the invention may employ one or more load balancers 501. These load balancers 501 route both incoming data retrieval requests and incoming data submission requests from remote communication devices 119 to a gateway server 101. With these embodiments, when a load balancer receives a request, it first checks to determine if the request contains routing information, such as a cookie as described above. If the request does not contain routing information, then the load balancer 501 assigns the request to a gateway server 101 based upon the current load distribution of all of the gateway servers 101, as known in the art. If, however, the load balance 501 determines that a request does contain routing information, then it routes the request to the gateway server 101 identified in the routing information. As will be appreciated by those of ordinary skill in the art, with this arrangement each load balancer 501 may have a public network address, such as a public Internet protocol (IP) address. The gateway servers 101 behind the load balancers 501 may then have virtual network addresses that cannot be directly accessed from outside of the network. For these implementations of the invention, the routing information will provide the virtual network address for the desired gateway server 101, and the load balancer 501 receiving a request containing the routing information can then map the request to the identified gateway server 101. With various examples of the invention, the redirect response may also contain additional “handoff” information to be inserted into the subsequent requests for the desired data. When the routed gateway server 101 then receives a subsequent request for the desired, it can determine from the handoff information that the request is a handoff from another gateway server 101. The handoff information may also contain a time stamp, so that the routed gateway server 101 can confirm that the handoff was recent. Using this information, it will associate the request with a presentation session on the initial gateway server 101. The routed gateway server 101 can thus collocate the presentation session from the presentation service 115 of the initial gateway server 101 to its own presentation service 115, so that its own presentation service 115 returns the desired data to the remote communication device 119 when it is retrieved. According to still other embodiments of the invention, the routed gateway server 101 may use the handoff information to employ the authentication performed by the initial gateway server 101, thereby avoiding requiring that the user reauthenticate himself or herself. Accordingly, for these embodiments, the handoff information may be encrypted, to prevent unauthorized users from creating false handoff information to avoid authentication. Of course, the handoff information may be encrypted even if the routed gateway server 101 does not employ the authentication performed by the initial gateway server 101. Also, it should be noted that, with various embodiments of the invention, the collocation process can alternately be performed by the load balancers 501, but this may require customized code. Thus, referring back to the above example for USER1, after a request for data from USER1 is initially routed to gateway server 101B, the gateway server 101B may determine from a query to the directory 127 that the user's access client 103 is currently connected to the gateway server 101A (i.e., to the real-time service 117A). Accordingly, the gateway server 101B provides a redirect response to the remote communication device 119A with handoff information. The handoff information will include routing information, such as, e.g., a virtual network address, for the gateway server 101A. The handoff information may also be encrypted, and may include a time stamp and, e.g., confirmation of USER1's authentication. When USER1 resubmits requests for the desired information, the new requests will include the handoff information. Accordingly, when the load balancer 501A receives the resubmitted requests, it will route the requests to the gateway server 101A for handling. As will be appreciated by those of ordinary skill in the art, there may be some situations where this collocation process may not be employed. For example, a user may initially employ a first access client 103 to retrieve data. If that first access client 103 then fails before the data is retrieved, the user may be forced to employ a second delegated access client 103 to retrieve the information. In this scenario, it would not be desirable to reroute subsequent requests to another gateway server 101, as the gateway server 101 corresponding to the first access client 103 may already have some or all of the requested data in the cache 1151. Also, collocation may not be desirable when a user first signs up to the data retrieval system with the computer 105, but does not have an access client 103 installed yet. It also should be appreciated that, with different embodiments of the invention, a separate locator service may perform one or more of the collocation functions instead of the presentation service 115. For example, with some embodiments of the invention, a locator service may query the directory 127 to determine the gateway server 101 to which the user's access client 103 is currently connected, and then generate a corresponding redirect response for the remote communication device 119. Of course, various embodiments of the invention may alternately or additionally employ conventional remote call procedures to associate a presentation session maintained by a presentation service 115 on a gateway server 101 with a connection 121 maintained by a real-time service 117 on a different gateway server 101. Such remote call procedures may be employed, for example, instead of the collocation process described above, or if the collocation process fails for some reason. Secure Communication between the Access Client and the Real-Time Server To establish a secure connection to a computer, a browser will typically use an encryption protocol, such as the Hypertext Transfer Protocol Secure, which employs the Secure Sockets Layer (SSL) encryption technique. With this protocol, encryption key certificates are preinstalled, and public key and private keys are used during a “handshake” process to negotiate a session key for the connection. With an SSL handshake, a third party cannot determine the session key, even if all of the exchanged data is intercepted. This type of protocol requires a great deal of resource overhead to begin, however, and requires a great deal of resource overhead to maintain. Moreover, with various examples of the invention, the presentation service 115 may be implemented using a conventional Web server, but the real-time service 117 may be implemented using a different type of server. With this arrangement, the real-time service 117 may use HTTP and/or HTTPS communications, but only to deliver messages through firewalls (e.g., for requests to Port 80, which conventionally are passed by firewalls). Accordingly, it would be beneficial to allow the access client 103 and the real-time service 117 without maintaining an SSL session. Advantageously, various embodiments of the invention allow the access client 103 to communicate with the real-time service 117 without having to maintain an SSL session. According to these embodiments, the load balancers 501 also serve as encryption protocol terminators in addition to load balancers. That is, the load balancer may have SSL software or hardware (e.g., SSL accelerator cards) that handles SSL communications very quickly. When the load balancer passes a communication onto a gateway server 101, the communication thus is decrypted to a regular HTTP format (i.e., the load balancer 501 decrypts the communication before passing it to the gateway server 101). These specialized load balancers are known in the art and may be obtained from a variety of sources, and thus will not be discussed in further detail. When the access client 103 attempts to establish a connection to the real-time service 117, it does not communicate directly with the real-time service 117. Instead, the access client 103 initially transmits an encrypted message, such as a HTTPS message, through a load balancer 501 to a presentation server 115. The HTTPS message is received at the load balancer 501, which decrypts the message and routes the message to a presentation service 115 as a HTTP message. More particularly, the load balancer 501 routes the request to the presentation service 115 of a gateway server 101 according to its balancing algorithm (e.g., to the gateway server 101 that is the least busy). The presentation service 115 then calls into the real-time service 117 to report that the access client 103 will soon be providing a request to establish a connection. In response, the real-time service 117 creates an entry in a list of pending connections (e.g., a table of access clients 103 that will soon be connecting to the real-time service 117). In response, a unique session encryption key is generated (e.g., a 128-bit key), which is unrelated to the initial SSL communication between the access client 103 and the load balancer 501. Any desired encryption algorithm, such as RC4, may be used to generate the encryption key. The entry in the table will thus include the identity of the access client 103, a public session identification and a private encryption key. The presentation service 115 then sends an HTTP reply that contains the address (such as a universal resource location (URL) address) corresponding to the real-time service 117 to which the access client 103 should connect. The reply also includes the public session identification and the private encryption key. The access client 103 can then transmit a message to the real-time service 117 using the address (e.g., using a URL of the form http://www.gateway.com/real-timeserver sessionID=xxxxxx). Using this arrangement, the message sent from the access client 103 to the real-time service 117 may be an unencrypted HTTP message, but the data in the message can be encrypted using the private encryption key. The real-time service 117 can then use the session identification in the message to locate the appropriate entry in the table with the corresponding private encryption key. The real-time service 117 will then decrypt the contents of the message with the private encryption key. Thus, the access client 103 and the real-time service 117 can communicate without maintaining an encryption session. Instead, the access client 103 and the real-time service 117 can use the public session identification and the private encryption key to securely communicate. Moreover, by handing off the connection directly to the real-time service 117, these embodiments of the invention can avoid maximizing the limit of the load balancer 501. Of course, with still other embodiments of the invention, the access client 103 and the real-time service 117 can securely communicate while maintaining an encryption session (such as a SSL encryption session), but also have the data exchanged over the secure connection separately encrypted. That is, the data exchanged over the secure connection may use different encryption information, as described in detail above, than the encryption information used to maintain the secure connection. CONCLUSION While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth in the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Recently, digital information has become more and more important to people of all walks of life. As the importance of digital information has increased, the need for convenient remote access to a variety of types of digital information has increased as well. For example, traveling businessmen may desire continual access to information contained in electronic spreadsheets, attorneys may desire access to word processing documents from a client's location, and students may want to send or retrieve electronic mail while in school. In order to address this need, many communication service providers allow their customers to access remote digital information through a communication network. For example, a wireless telephone service provider may allow its customers to use their wireless telephones or other communication devices to send and receive retrieve electronic mail, retrieve image information from a network, obtain contact information from a centralized database, or the like. Similarly, some companies have established remote high-speed Internet connections, both wired and wireless, at public locations such as restaurants, hotels, and airports, which can be accessed by a customer's computer. While communication service providers have created an infrastructure that potentially allows their customers remote access to digital information, many practical issues still prevent this infrastructure from being fully utilized. For example, some customers seek to access digital information stored behind a barrier, such as digital information stored in their employer's database and protected by a firewall. With this arrangement, if the employer's network did not support an access tool allowing external connections through the firewall then a customer would be prevented from accessing the desired digital information through the communication service provider's network. These access tools include, for example, the use of a virtual private network (VPN) or similar techniques for enabling secure and authenticated connections from devices not directly connected to the employer's network. Moreover, even if the employer's network supported such a tool, the customer's communication device could still not access the data if the user's device itself was not configured to support that tool. In other situations, a customer may attempt to use an unsuitable communication device to retrieve data. For example, a user may attempt to employ a personal digital assistant or wireless telephone with a relatively simple browser to retrieve a Web page with a large amount of image or audio data. Before the large amount of data can be fully retrieved, the personal digital assistant or wireless telephone may “time out” and sever the connection. Alternately or additionally, the user may seek to download more data than the personal digital assistant or wireless telephone may store. | <SOH> SUMMARY <EOH>Advantageously, various examples of the invention allow a user to more conveniently send data to and retrieve data from a remote data store using a remote communication device. With different aspects of the invention, a data retrieval system includes an inbox (IB) server, referred to hereafter more generally as a “gateway server,” and a desktop access client (DAC), referred to hereafter more generally simply as an access client. The gateway server is communicatively connected to the access client through a network. The gateway server provides a presentation service (PS) and a real-time service (RTS), which cooperate with the access client to retrieve data from a data store and then provide the retrieved data to a user's remote communication device using a presentation protocol appropriate to the device's capabilities. With various implementations of the invention, the access client will create a connection to the gateway server. When the user wishes to retrieve data from the data store or to send data to the data store, the user establishes a communication connection between his or her remote communication device and the gateway server, and then requests the desired data from the gateway server. In response, the gateway server sends a command to the access client, instructing it to retrieve the requested data. The access client retrieves the requested data from the data store, and returns the retrieved data to the gateway server. The gateway server then relays the requested information back to the user's remote communication device through the presentation server using a presentation protocol appropriate to the device's capabilities. | 20040202 | 20080422 | 20050203 | 61439.0 | 1 | SHINGLES, KRISTIE D | ASYNCHRONOUS REAL-TIME RETRIEVAL OF DATA | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,770,857 | ACCEPTED | CONTROL OF FRICTION AT THE NANOSCALE | Methods and apparatus are described for control of friction at the nanoscale. A method of controlling frictional dynamics of a plurality of particles using non-Lipschitzian control includes determining an attribute of the plurality of particles; calculating an attribute deviation by subtracting the attribute of the plurality of particles from a target attribute; calculating a non-Lipschitzian feedback control term by raising the attribute deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and imposing the non-Lipschitzian feedback control term globally on each of the plurality of particles; imposing causes a subsequent magnitude of the attribute deviation to be reduced. | 1. A method, comprising controlling frictional dynamics of a plurality of separate individual particles using non-Lipschitzian feedback control including: measuring a property of the plurality of separate individual particles; calculating a velocity of the plurality of separate individual particles as a function of the property, the velocity of the plurality of separate individual particles being a center of mass velocity V c m = ( 1 / N ) ∑ n = 1 N φ . n , where N is a total number of the plurality of separate individual particles; calculating a velocity deviation by subtracting the velocity of the plurality of separate individual particles from a target velocity; calculating a non-Lipschitzian feedback control term comprising a non-Lipschitzian terminal attractor and a non-Lipschitzian terminal repeller the terminal attractor being calculated by raising the velocity deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; calculating a time dependent average velocity νav that represents a moving run-time average of νcm, wherein the non-Lipschitzian feedback control term is represented by: C(t)=α(νtarget−νcm)ξ−β(νav−νcm)ξsgn[(νav−νcm)(νcm−νtarget)]H[r−|νtarget−νav|]., wherein α is the control amplitude and represents a weight of the non-Lipschitzian terminal attractor, β is another control amplitude and represents another weight of the non-Lipschitzian terminal repeller, H(•) denotes a Heaviside function defined as H(z)=1 for z>0, H(z)=1 for z=0 and H(z)=0 for z<0, r represents a threshold, νtarget is the target velocity νtarget−νcm is the velocity deviation; and imposing the non-Lipschitzian feedback control term globally on each of the plurality of separate individual particles, wherein imposing causes a subsequent magnitude of the velocity deviation to be reduced. 2. The method of claim 1, further comprising repeating the steps of measuring the property of the plurality of separate individual particles, calculating the velocity of the plurality of separate individual particles, calculating the velocity deviation and imposing the non-Lipschitzian feedback control term globally. 3. The method of claim 2, further comprising repeating the steps of calculating the non-Lipschitzian feedback control term to define a recalculated non-Lipschitzian feedback control term and imposing the recalculated non-Lipschitzian feedback control term globally on each of the plurality of separate individual particles. 4. The method of claim 3, wherein repeating the steps of measuring the property of the plurality of separate individual particles, calculating the velocity of the plurality of separate individual particles, calculating the velocity deviation and imposing the non-Lipschitzian feedback control term globally is performed multiple times before repeating the step of calculating the non-Lipschitzian feedback control term to define the recalculated non-Lipschitzian feedback control term and imposing the recalculated non-Lipschitzian feedback control term globally on each of the plurality of separate individual particles. 5. The method of claim 3, wherein periods of controlled and uncontrolled dynamics alternate according to a specified protocol selected from the group consisting of pulsed control and quasi-pulsed control. 6. The method of claim 1, wherein imposing includes coupling an optical pulse to the plurality of separate individual particles. 7. The method of claim 1, wherein the plurality of separate individual particles include an array of nanoparticles. 8. The method of claim 7, wherein the array of nanoparticles includes a one dimensional array of nanoparticles. 9. The method of claim 7, wherein the array of nanoparticles includes a two dimensional array of nanoparticles. 10. The method of claim 1, further comprising changing the control amplitude. 11. The method of claim 1, further comprising changing the target velocity. 12. (canceled) 13. The method of claim 12, wherein ξ=1/(2n+1) where n=1, 2, 3 . . . and dC/dνcm→−∞ as νcm→νtarget. 14. (canceled) 15. The method of claim 1, further comprising changing the another control amplitude. 16. The method of claim 1, further comprising changing a radius. 17-37. (canceled) 38. An apparatus, comprising: a general dynamic system including a plurality of separate individual particles; and a global feedback system that controls an attribute of the plurality of separate individual particles using non-Lipschitzian control, including: a characterization instrument that determines a velocity of the plurality of separate individual particles, the velocity of the plurality of separate individual particles being a center of mass velocity V c m = ( 1 / N ) ∑ n = 1 N φ . n , where N is a total number of the plurality of separate individual particles; a logic module that calculates I) a velocity deviation by subtracting the velocity of the plurality of separate individual particles from a target velocity and II) a non-Lipschitzian feedback control term comprising a non-Lipschitzian terminal attractor and a non-Lipschitzian terminal repeller, the terminal attractor being calculated by raising the velocity deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and further calculates a time dependent average velocity νav that represents a moving run-time average of νcm, wherein the non-Lipschitzian feedback control term is represented by: C(t)=α(νtarget−νcm)ξ−β(νav−νcm)ξsgn[(νav−νcm)(νcm−νtarget)]H[r−|νtarget−νav|]., wherein α is the control amplitude and represents a weight of the non-Lipschitzian terminal attractor, β is another control amplitude and represents another weight of the non-Lipschitzian terminal repeller, H(•) denotes a Heaviside function defined as H(z)=1 for z>0, H(z)=1 for z=0 and H(z)=0 for z<0, r represents a threshold, νtarget is the target velocity, νtarget−νcm is the velocity deviation; and a tool that imposes the non-Lipschitzian feedback control term globally on each of the plurality of separate individual particles of the inertial dynamic system, wherein a subsequent magnitude of the velocity deviation is reduced. 39. The apparatus of claim 38, wherein the plurality of separate individual particles include a plurality of nanoparticles and the attribute includes at least one member selected from a group consisting of slip time and a frictional force. 40. The apparatus of claim 38, wherein the tool includes a plurality of lasers and the attribute includes at least one member selected from a group consisting of slip time and a frictional force. 41. A method, comprising controlling an attribute of a plurality of separate individual members of a general dynamic system using non-Lipschitzian control including: determining a velocity of the plurality of separate individual members, the velocity of the plurality of separate individual members being a center of mass velocity V c m = ( 1 / N ) ∑ n = 1 N φ . n , where N is a total number of the plurality of separate individual members; calculating a velocity deviation by subtracting the velocity of the plurality of separate individual members from a target velocity; calculating a non-Lipschitzian feedback control term comprising a non-Lipschitzian terminal attractor and a non-Lipschitzian terminal repeller, the terminal attractor being calculated by raising the velocity deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude, and further calculating a time dependent average velocity νav that represents a moving run-time average of νcm, wherein the non-Lipschitzian feedback control term is represented by: C(t)=α(νtarget−νcm)ξ−β(ξav−νcm)ξsgn[(νav−νcm)(νcm−νtarget)]H[r−|νtarget−νav|]., wherein α is the control amplitude and represents a weight of the non-Lipschitzian terminal attractor, β is another control amplitude and represents another weight of the non-Lipschitzian terminal repeller, H(•) denotes a Heaviside function defined as H(z)=1 for z>0, H(z)=1 for z=0 and H(z)=0 for z<0 r represents a threshold, νtarget is the target velocity νtarget−νcm, is the velocity deviation; and imposing the non-Lipschitzian feedback control term globally on each of the plurality of separate individual members of the general dynamic system, wherein imposing causes a subsequent magnitude of the attribute deviation to be reduced. 42. The method of claim 41, further comprising repeating the steps of determining the attribute of the plurality of separate individual members, calculating the attribute deviation, calculating the non-Lipschitzian feedback control term to define a recalculated non-Lipschitzian feedback control term and imposing the recalculated non-Lipschitzian feedback control term globally on each of the plurality of separate individual members. 43. The method of claim 42, wherein repeating the steps of determining the attribute of the plurality of separate individual members, calculating the attribute deviation and imposing the non-Lipschitzian feedback control term globally is performed multiple times before repeating the steps of calculating the non-Lipschitzian feedback control term to define the recalculated non-Lipschitzian feedback control term and imposing the recalculated non-Lipschitzian feedback control term globally on each of the plurality of separate individual members. 44. The method of claim 42, wherein periods of controlled and uncontrolled dynamics alternate according to a specified protocol selected from a group consisting of pulsed control and quasi-pulsed control. 45. The method of claim 41, wherein the plurality of separate individual members include a plurality of nanoparticles and the attribute includes at least one member selected from a group consisting of an average sliding velocity, slip time and frictional force. 46. The method of claim 41, wherein imposing includes using a plurality of lasers and the attribute includes at least one member selected from a group consisting of intensity and phase. 47-48. (canceled) 49. An apparatus, comprising: a general dynamic system including a plurality of separate individual members; and a global feedback system that controls an attribute of the plurality of separate individual members using non-Lipschitzian control, including: a characterization instrument that determines the attribute of the plurality of separate individual members; a logic module that calculates I) a velocity deviation by subtracting a velocity of the plurality of separate individual members from a target velocity, the velocity of the plurality of separate individual members being a center of mass velocity V c m = ( 1 / N ) ∑ n = 1 N φ . n , where N is a total number of the plurality of separate individual members: and II) a non-Lipschitzian feedback control term comprising a non-Lipschitzian terminal attractor and a non-Lipschitzian terminal repeller, the terminal attractor being calculated by raising the velocity deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and further calculates a time dependent average velocity νav that represents a moving run-time average of νcm, wherein the non-Lipschitzian feedback control term is represented by: C(t)=α(νtarget−νcm)ξ−β(νav−νcm)ξsgn[(νav−νcm)(νcm−νtarget)]H[r−|νtarget−νav|]., wherein α is the control amplitude and represents a weight of the non-Lipschitzian terminal attractor, β is another control amplitude and represents another weight of the non-Lipschitzian terminal repeller, H(•) denotes a Heaviside function defined as H(z)=1 for z>0, H(z)=1 for z=0 and H(z)=0 for z<0 r represents a threshold νtarget is the target velocity, νtarget−νcm is the velocity deviation, and a tool that imposes the non-Lipschitzian feedback control term globally on each of the plurality of separate individual members of the inertial dynamic system, wherein a subsequent magnitude of the attribute deviation is reduced. 50. The apparatus of claim 49, wherein the plurality of separate individual members include a plurality of nanoparticles and the attribute includes at least one member selected from a group consisting of an average sliding velocity, slip time and a frictional force. 51. The apparatus of claim 49, wherein the tool includes a plurality of lasers and the attribute includes at least one member selected from a group consisting of intensity and phase. | STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT This invention was made with United States Government support under prime contract No. DE-AC05-00OR22725 to UT-Battelle, L.L.C. awarded by the Department of Energy. The Government has certain rights in this invention. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates generally to the field friction control. More particularly, the invention relates to control of friction at the micro and nano scale. 2. Discussion of the Related Art Despite great progress made during the past half century, many problems in fundamental tribology (such as the origin of friction and failure of lubrication) have remained unsolved. Moreover, the current reliable knowledge related to friction and lubrication is mainly applicable to macroscopic systems and machinery and, most likely, will be only of limited use for micro- and nano-systems. Indeed, when the thickness of the lubrication film is comparable to the molecular or atomic size, the behavior of the (film) lubricant becomes significantly different from the behavior of macroscopic (bulk) lubricant [1]. Better understanding of the intimate mechanisms of friction, lubrication, and other interfacial phenomena at the atomic and molecular scales is needed to provide designers and engineers the required tools and capabilities to monitor and control friction, reduce unnecessary wear, and predict mechanical faults and failure of lubrication in micro-electro-mechanical systems (MEMS) and nano-devices [2]. The ability to control and manipulate friction during sliding is extremely important for a large variety of technological applications. The outstanding difficulties in realizing efficient friction control are related to the complexity of the task, namely dealing with systems with many degrees of freedom under strict size confinement, and only very limited control access. Moreover, a nonlinear system driven far from equilibrium may exhibit a variety of complex spatial and temporal behaviors, each resulting in different patterns of motion and corresponding to different friction coefficient [3]. Friction can be manipulated by applying small perturbations to accessible elements and parameters of a sliding system [4-10]. Usually, these control methods are based on non-feedback controls. Recently, the groups of J. Israelachvili [4] (experimental) and U. Landman [5] (full-scale molecular dynamics computer simulation) showed that friction in thin-film boundary lubricated junctions can be reduced by coupling small amplitude (of the order of 1 Å) directional mechanical oscillations of the confining boundaries to the molecular degree of freedom of the sheared interfacial lubricating fluid. Using a surface force apparatus, modified for measuring friction forces while simultaneously inducing normal (out-of-plane) vibrations between two boundary-lubricated sliding surfaces, load- and frequency-dependent transitions between a number of “dynamical friction” states have been observed [4]. In particular, regimes of vanishingly small friction at interfacial oscillations were found. Extensive grand-canonical molecular dynamics simulations [5] revealed the nature of the dynamical states of confined sheared molecular films, their structural mechanisms, and the molecular scale mechanisms underlying transitions between them. Methods to control friction in systems under shear that begin to enable the elimination of chaotic stick-slip motion were proposed by Rozman et al [6]. Significant changes in frictional responses were observed in the two-plate model [7] by modulating the normal response to lateral motion [8]. In addition, the surface roughness and the thermal noise are expected to play a significant role in deciding control strategies at the micro and the nano-scale [9, 10]. Since feedback control methods require specific knowledge of the strength and timing of the perturbations, their application to nano-friction has been very limited. On the other hand, feedback control methods (e.g., proportional feedback) have been applied extensively in many engineering fields. All these feedback controls have been Lipschitzian. Recently, non-Lipschitzian (terminal attractor based) feedback control has been successfully implemented in first order systems such as neural networks [11, 12]. Despite their relative simplicity, phenomenological models of friction at the atomic level [10,13-16] show a fair agreement with many experimental results using either friction force equipment [7,18,19] or quartz microbalance experiments [9,17,20]. The basic equations for the driven dynamics of a one dimensional particle array of N identical particles moving on a surface are given by a set of coupled nonlinear equations of the form [16]: m{umlaut over (x)}j+γ{dot over (x)}j/∂U/∂xj−∂V/∂xj+fj+η(t), j=1, . . . N (1) where xj is the coordinate of the jth particle, m is its mass, Y is the linear friction coefficient representing the single particle energy exchange with the substrate, fj is the applied external force, and η(t) is Gaussian noise. The particles in the array are subjected to a periodic potential, U(xj+a)=U(xj), and interact with each other via a pair-wise potential V(xj−xi), j, i=1, 2, . . . N. A system represented by Equation (1) provides a general framework of modeling friction although the amount of detail and complexity varies in different studies from simplified one dimensional models [15,16,21,22] through two dimensional and three dimensional models [17,23,24,25] to a full set of molecular dynamics simulations [25,26]. Phenomenological models of friction at the atomic level can include the following simplifications (assumptions): (i) the substrate potential is a simple periodic form, (ii) there is a zero misfit length between the array and the substrate, (iii) the same force f is applied to each particle, and (iv) the interparticle coupling is linear. The coupling with the substrate is, however, strongly nonlinear. For this case, using the dimensionless phase variables φj=2πxj/a, the equation of motion reduces to the dynamic Frenkel-Kontorova model [16] {umlaut over (φ)}j+γ{dot over (φ)}j+sin(φj)=f+κ(φj+1−2φj+φj−1) (2) Without control, Equation (2) exhibits four different regimes: (i) rest (no motion), (ii) periodic sliding, (iii) periodic stick-slip, and (iv) chaotic stick-slip. Different motion types are obtained by only changing the initial conditions of the particle's positions and velocities, but not the system's parameters. The average velocity of the center of mass for the “natural” (i.e., uncontrolled) motion, may take only a limited range of values, namely: (i) ν=0 for rest (no sliding), (ii) ν=f/γ for periodic sliding motion, and (iii) ν=nν0, where n is an integer, v 0 = 2 π nN γ π - cos - 1 f π ( κ - κ c ) 1 / 2 , for periodic stick-slip motion, [16]. SUMMARY OF THE INVENTION There is a need for the following aspects of the invention. Of course, the invention is not limited to these aspects. According to an aspect of the invention, a process comprises: controlling frictional dynamics of a plurality of particles using non-Lipschitzian feedback control including: measuring a property of the plurality of particles; calculating a velocity of the plurality of particles as a function of the property; calculating a velocity deviation by subtracting the velocity of the plurality of particles from a target velocity; calculating a non-Lipschitzian (terminal attractor based) feedback control term by raising the velocity deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and imposing the non-Lipschitzian (terminal attractor based) feedback control term globally on each of the plurality of particles, wherein imposing causes a subsequent magnitude of the velocity deviation to be reduced. According to another aspect of the invention, a method comprises controlling frictional dynamics of a plurality of particles using non-Lipschitzian feedback control including determining an attribute of the plurality of particles; calculating an attribute deviation by subtracting the attribute of the plurality of particles from a target attribute; calculating a non-Lipschitzian feedback control term by raising the attribute deviation to a fractionary power 4=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and imposing the non-Lipschitzian feedback control term globally on each of the plurality of particles, wherein imposing causes a subsequent magnitude of the attribute deviation to be reduced. According to another aspect of the invention, an apparatus comprises a general dynamic system including a plurality of particles and a global feedback system that controls an attribute of the plurality particles using non-Lipschitzian control, including a characterization instrument that determines the attribute of the plurality of particles; a logic module that calculates I) an attribute deviation by subtracting the attribute of the plurality of particles from a target attribute value and II) a non-Lipschitzian feedback control term by raising the attribute deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and a tool that imposes the non-Lipschitzian feedback control term globally on each of the plurality of particles of the inertial dynamic system, wherein a subsequent magnitude of the attribute deviation is reduced. According to another aspect of the invention, a process comprises: controlling an attribute of a plurality of members of a general dynamic system using non-Lipschitzian control including: determining an attribute of the plurality of members; calculating an attribute deviation by subtracting the attribute of the plurality of members from a target attribute value; calculating a terminal attractor based control term by raising the attribute deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and imposing the terminal attractor based control term globally on each of the plurality of members of the inertial dynamic system, wherein imposing causes a subsequent magnitude of the attribute deviation to be reduced. According to another aspect of the invention, a machine comprises: a general dynamic system including a plurality of members; and a global feedback system that controls an attribute of the plurality members using non-Lipschitzian control, including: a characterization instrument that determines the attribute of the plurality of members; a logic module that calculates I) an attribute deviation by subtracting the attribute of the plurality of members from a target attribute value and II) a terminal attractor based control term by raising the attribute deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and a tool that imposes the terminal attractor based control term globally on each of the plurality of members of the inertial dynamic system, wherein a subsequent magnitude of the attribute deviation is reduced. These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions and/or rearrangements may be made within the scope of the invention without departing from the spirit thereof, and the invention includes all such substitutions, modifications, additions and/or rearrangements. BRIEF DESCRIPTION OF THE DRAWINGS The drawings accompanying and forming part of this specification are included to depict certain aspects of the invention. A clearer conception of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore nonlimiting, embodiments illustrated in the drawings. The invention may be better understood by reference to one or more of these drawings in combination with the description presented herein. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale. FIGS. 1A-1D illustrate performance of the invention in the context of friction control with respect to four different target velocities by plotting the velocity of the center of mass of a plurality of particles as a function of time, together with (in each of the four cases) an imposed target, representing embodiments of the invention. FIG. 2 illustrates performance of the invention in the context of friction control with respect to four different examples by plotting the velocity of the center of mass of a plurality of particles as a function of the magnitude of the control amplitude, α, for three different targets, representing embodiments of the invention. DESCRIPTION OF PREFERRED EMBODIMENTS The invention and the various features and advantageous details thereof are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well known starting materials, processing techniques, components and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only and not by way of limitation. Various substitutions, modifications, additions and/or rearrangements within the spirit and/or scope of the underlying inventive concept will become apparent to those skilled in the art from this disclosure. Within this application several publications are referenced by Arabic numerals within brackets. Full citations for these, and other, publications may be found at the end of the specification immediately preceding the claims after the section heading References. The disclosures of all these publications in their entireties are hereby expressly incorporated by reference herein for the purpose of indicating the background of the invention and illustrating the state of the art. The invention can include a method (and/or apparatus based on the method) to control a dynamic attribute of a plurality of structures toward a pre-assigned (pre-determined) value or variable behavior of that attribute. The control of the dynamic attribute can be based on the concepts of non-Lipschitzian dynamics and the use of a non-Lipschitzian global feedback control term. Optionally, the invention can include maintaining the control until the deviation is reduced to zero whereupon the target has been reached. In a preferred embodiment, the invention can include a method (and/or apparatus based on the method) to control sliding and frictional properties (such as friction coefficient, friction force, sliding velocity, slip time) of a plurality (e.g., array) of atoms and/or molecules towards a pre-assigned (pre-determined) value of a target (average sliding velocity, slip time, friction coefficient and friction force). The invention can also include a method (and/or apparatus based on the method) to control shear forces and static forces, viscosity, and adhesion forces towards a pre-assigned value of a target (shear and static forces, viscosity, and adhesion forces). The invention can also include a method (and/or apparatus based on the method to control sliding trajectory, speed, direction and diffusion of atomic and molecular chains and polymers sliding on surfaces towards a pre-assigned value of a target (sliding trajectory, speed direction and diffusion coefficient). Implementation of the non-Lipschitzian friction control technique is applicable but not limited for slip time and velocity control in a quartz micro balance apparatus, friction coefficient and friction force control in an atomic force microscope, and friction forces, loss and elastic moduli control in a surface force apparatus. Implementation of non-Lipschitzian control algorithm can be achieved either through imposing controlled vibrations of the sliding surfaces and/or the AFM tip (normal and/or in-plane) or electromechanical, electro-optical, or optical excitations applied to the sliding system and/or the lubricant according to the proposed algorithm. Implementation of control algorithm can be also achieved by imposing controlled vibrations of the sliding surfaces with a surface force apparatus, a quartz microbalance and/or using cantilevers and/or cantilever arrays. In addition, electromechanical, electro-optical, and optical control can be utilized in conjunction with (applicable for) all the previously described friction measurement apparatuses. As in the generic case, this control can be based on the concepts of non-Lipschitzian dynamics and the use of a (terminal attractor based) non-Lipschitzian global feedback control term. Extensive numerical simulations, some of which are described below, have actually proven the robustness, efficiency, and convenience of the invention applied in the context of controlling friction. Non-Lipschitzian (terminal attractor based) global control feedback is an important aspect of the invention and provides several advantages. First, the presence of a terminal attractor in the control term provides robustness and ensures very fast approach to target. Second, the global control turns out to be more efficient and easier to implement compared to non-global control. Fast time scales and ease of implementation make the invention a very suitable tool for phenomena in nanoscale systems where accessibility is an issue (as in friction, for instance). However, the applicability of the invention is quite general. This preferred embodiment of the invention can include an algorithm to control friction of sliding nano-arrays. This algorithmic control can be based on the concept of a terminal attractor and is global in that: (i) it can require only knowledge of the velocity of the center of mass and (ii) it can be applied globally to the all members of the plurality of particles (e.g., the whole array). The inventors have already demonstrated the efficiency and robustness of the control by reaching a broad spectrum of target velocities—both close to or far from natural attractors—in very short transient times. Extensive numerical simulations have been performed on arrays of different sizes (3<N<256) in order to verify that size effects are not critical for the inventive control. The numerical and graphical results of some of these numerical simulations are presented in FIGS. 1A-1D and FIG. 2 for a typical one-dimensional nano-array of N=15 particles. In this preferred embodiment, the velocity of the particles (e.g., average sliding, center of mass velocity of an array of nanoparticles) can be measured using a quartz crystal microbalance. The control term can be imposed on each of the plurality of particles via an optical pulse (e.g., from a tuned laser). The optical pulse can define a spot (having a size and flux density) that is sufficiently large and uniform to evenly impose the control term on each of the plurality of particles. In this case, the optical pulse intensity and its duration should be controlled electronically via the control term which can be provided as an input signal to the electronics. A plurality of such optical pulses over time can in-turn define a duty cycle. In an alternative embodiment, the invention can include a method (and/or apparatus based on the method) to control intensity, phase, (e.g., synchronized array) of lasers towards a pre-assigned (pre-determined) value of a target intensity and/or target phases. Again, this control can be based on the concepts of non-Lipschitzian dynamics and the use of a non-Lipschitzian (terminal attractor based) global feedback control term. In this alternative embodiment, the intensity and/or phases of the lasers can be measured using a charge coupled device. The control term can be imposed on each of the plurality of lasers via electronics or optics that are provided with the control term as an input signal to the electronics. It is important to appreciate that the invention can address fundamental issues related to targeting and control of an attribute of a dynamic system (e.g., friction in nanoscale driven nonlinear particle arrays, synchronization of laser arrays, etc.), by using the global feedback control approach that is based on the properties of terminal attractors. It should be appreciated that the invention can include the application of terminal attractors to second order systems (e.g., friction control, laser synchronization, etc.). It should also be appreciated that the invention can include the feed back of such a non-Lipschitzian feedback control in the context of a second order system, simultaneously, into all state equations, thereby defining a non-Lipschitzian feedback global feedback control. When applying the control to the nano-array, the inventors' objectives were to: (i) provide the ability to reach a targeted value of the average sliding velocity using only small values of the control; (ii) significantly reduce the transient time needed to reach the desired behavior. To that effect, the invention can include a global feedback control algorithm that uses the concept of a terminal attractor, which is usually associated to non-Lipschitzian dynamics. The equations of motion in the presence of the terminal attractor based control term C(t) read: {umlaut over (φ)}j+γ{dot over (φ)}j+sin(φj)=f+κ(φj+1−2φj+φj−1)+C(t) (3) where C(t)=α(νtarget−νcm)ξ (4) is the non-Lipschitzian control term based on the concept of terminal attractor. In Equation (3), the first term on the left represent the an acceleration of a particle j, the second term on the left represents a velocity of the particle j, the third term on the left represents a position of the particle j, the first term on the right f is a (e.g., ambient) force applied to the particles, the second term on the right represents the interaction between the particle j and its two nearest neighbors j−1 and j+1 (κ is a strength of interaction between a particle of interest and its two nearest neighbors) and the third term on the right represents the non-Lipschitzian feedback (terminal attractor based) control term. In Equation (4), v c m = ( 1 / N ) ∑ n = 1 N φ . n and represents the average (e.g., center of mass) velocity of the plurality of particles, νtarget is the targeted (pre-determined) velocity (e.g., for the center of mass of the plurality of particles), a is the control amplitude, ξ=1/(2n+1), and n=1, 2, 3 . . . . More generically, the fractional power can be of the form ξ=(2m+1)/(2n+1), where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n. Preferred embodiments of the invention utilize the fractional power form where the numerator is 1 since these provide enhanced efficiency in practical dynamic implementations. While most dynamical systems of interest do satisfy the Lipschitz condition, the terminal attractor dynamics that the inventors have discovered is so useful for controlling friction violates it by design. As a result, trajectories reach the terminal attractor in finite time. To illustrate this phenomenon, consider a simple example of a terminal attractor, namely the equation {dot over (φ)}=−φ1/7. At the equilibrium point, φ=0, the Lipschitz condition is violated, since ∂{dot over (+)}/∂φ=−( 1/7)φ−6/7 tends to minus infinity as +tends to zero. Thus, the equilibrium point φ=0 is an attractor with “infinite” local stability. This is precisely the effect realized with the control term C(t). Indeed: C v c m = - ( 1 / 7 ) α ( v target - v c m ) - 6 / 7 , i . e . , C v c m -> - ∞ as v c m -> v target . ( 5 ) It is important to note that the determination (calculation) of the non-Lipschitzian feedback control term requires only knowledge of the average velocity of the plurality of particles (e.g., array), which is an readily (experimentally observable) available quantity. It is also important to note that the non-Lipschitzian feedback control term can be applied identically and concomitantly to all the particles (e.g., in the array) upon which it acts as a uniform force proportional to (νtarget−νcm)ξ. To assess the performance of the invention for more “realistic” interaction potentials, the inventors replaced the linear interaction in Equation (3) by the Morse interaction: F j = γ β { exp [ - β ( φ j + 1 - φ j ) ] - exp [ - 2 β ( φ j + 1 - φ j ) ] } - γ β { exp [ - β ( φ j - φ j - 1 ) ] - exp [ - 2 β ( φ j - φ j - 1 ) ] } . The inventors' simulations indicate that the control algorithm remains robust and efficient. As already mentioned, the inventors also performed preliminary simulations for arrays as large as N=256. The outcome is comparable to the results presented here, which suggests that the invention remains efficient in systems larger than the atomic size. Experimental results are presented in FIGS. 1A-1D and FIG. 2 for ξ= 1/7, but the invention performs equally well for other values such as ⅓, ⅕ and 1/9, 1/11 . . . . FIG. 2 plots the center of mass velocity as a function of the maximum control amplitude α. The inventors chose three values of the target velocity, namely 0.1 (bottom), 1.0 (middle), and 3.0 (top). The triangles show the velocity of center of mass for control defined by Equation 6. All the parameters are the same as in FIG. 1 and initial conditions were chosen randomly. The inventors performed extensive testing of the embodiment of the invention represented by (Equations 3-4) by choosing numerous values of the target velocity. At the target itself, the non-Lipschitzian terminal attractor has “infinite attraction power”, which endows the invention with excellent efficiency and robustness, as illustrated in FIGS. 1A-1D for four values of the target velocity, namely: νtarget=0, . 2, 1 and 3. Referring to FIGS. 1A-1D, the bottom traces (red color lines) indicate the time series of the control (Equation 4), while the top traces (blue color lines) show the time series of the velocity of the center of mass. In all cases, the inventors reached and sustained the (arbitrarily chosen) target values for rather small values of the control. Thus, FIGS. 1A-1D illustrate performance of the control algorithm. The inventors picked four values of the target velocities: νtarget=0 (FIG. 1A), 0.5 (FIG. 1B), 1.0 (FIG. 1C), and 3.0 (FIG. 1D) for an N=15 particle array. Control was initiated at t=2000. In all of FIGS. 1A-1D, the top traces (blue lines) show time series of the center of mass velocities while the bottom traces (red lines) show the control. It is significant and important to note that in all cases, the desired behavior was achieved. The other parameters are: f=0.3, γ=0.1, κ=0.26, and ξ= 1/7. All the units are dimensionless and the initial conditions can be chosen randomly. The inventors applied the control at the time t=2000. All the results shown in FIGS. 1A-1D clearly indicate that with a very short transient time: convergence is very fast and the strength of the control is small. FIG. 2 illustrates the performance of the algorithm for different values of the target velocities as a function of the parameter α (see Equation 3). The inventors chose random set of initial conditions for each value of the parameter α. Indeed, for most target values the convergence to the target value is straightforward (see upper and middle curves). However, for a few values of νtarget, the dependence of the center of mass velocity, νcm on α turned out to be more irregular. These are the cases where the targeted values of the average velocities are in close proximity with those values without control (i.e. the desired behavior is in the vicinity of natural attractors of the uncontrolled array). Thus, the inventors modified the control as follows: C(t)=α(νtarget−νcm)ξ−β(νav−νcm)ξsgn[(νav−νcm)(νcm−νtarget)]H[r−|νtarget−νav|] (6) The second term in Equation (6) represents a repelling from a possible natural attractor of system (3) that would deflect the trajectory towards itself and away from the target velocity, νtarget. In general, the natural attractors are not known analytically and/or a priori. Their presence is indicated only by the behavior of the system and accounted for by νav, which is the “running” (time dependent) average velocity and represents the moving run-time average of νcm. H(•) denotes a Heaviside function, defined as H(z)=1 for z>0, and H(z)=0 for z<0. The Heaviside function can be further defined as H(z)=1 for z=0 or as H(z)=0 for z=0. The role of this Heaviside function is to activate the terminal repeller only within a neighborhood of radius r from the natural attractor. The radius r can be termed a threshold. The coefficients α and β are positive numbers that represent the weights of the non-Lipschitzian attractor and repeller, respectively. The inventors applied the algorithm to the target the value of ν=0.1 (see the bottom curve in FIG. 2). Here, the inventors are close to the static solution (stable fixed point) ν=0. Therefore, for some values of the control amplitude α, the outcome average velocity is ν=0 (instead of the desired velocity ν=0.1). The triangles in FIG. 2 shows the center of mass velocity as a function of a but using control defined in Equation 6. This control will repel the fixed point of ν=0, therefore the inventors observe even better performance of the invention. Practical Applications of the Invention A practical application of the invention that has value within the technological arts is as an efficient tool for controlling friction between a plurality of particles and a surface, between sliding surfaces and between sliding surfaces and a lubricant. The invention is applicable to quartz microbalance, atomic force microscope, and surface force apparatus-type experiments. The invention is also applicable to cantilevers and arrays of cantilevers, and in particular to micro-electro-mechanical systems (MEMS) where frictional contact and resulting wear are important factors in their design. The invention is also applicable to fast controls such as optical, or usage of micro/nano cantilevers. The invention is also applicable to implementations at time scales slower than the characteristic times of the dynamical system. Indeed, numerical simulations show that the control can be applied at much slower rates, while still maintaining the average value of the velocity close to the target. The “price” of such relaxed requirements are that longer times are needed to reach the target and larger fluctuations from the averaged value are observed. Another practical application of the invention is as a tool for synchronizing a plurality of lasers. There are virtually innumerable uses for the invention, all of which need not be detailed here. The terms a or an, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms “comprising” (comprises, comprised), “including” (includes, included) and/or “having” (has, had), as used herein, are defined as open language (i.e., requiring what is thereafter recited, but open for the inclusion of unspecified procedure(s), structure(s) and/or ingredient(s) even in major amounts. The terms “consisting” (consists, consisted) and/or “composing” (composes, composed), as used herein, close the recited method, apparatus or composition to the inclusion of procedures, structure(s) and/or ingredient(s) other than those recited except for ancillaries, adjuncts and/or impurities ordinarily associated therewith. The recital of the term “essentially” along with the terms “consisting” or “composing” renders the recited method, apparatus and/or composition open only for the inclusion of unspecified procedure(s), structure(s) and/or ingredient(s) which do not materially affect the basic novel characteristics of the composition. The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. The term approximately, as used herein, is defined as at least close to a given value (e.g., preferably within 10% of, more preferably within 1% of, and most preferably within 0.1% of). The term substantially, as used herein, is defined as largely but not necessarily wholly that which is specified. The term generally, as used herein, is defined as at least approaching a given state. The term deploying, as used herein, is defined as designing, building, shipping, installing and/or operating. The term means, as used herein, is defined as hardware, firmware and/or software for achieving a result. The term program or phrase computer program, as used herein, is defined as a sequence of instructions designed for execution on a computer system. A program, or computer program, may include a subroutine, a function, a procedure, an object method, an object implementation, an executable application, an applet, a servlet, a source code, an object code, a shared library/dynamic load library and/or other sequence of instructions designed for execution on a computer or computer system. All the disclosed embodiments of the invention disclosed herein can be made and used without undue experimentation in light of the disclosure. The invention is not limited by theoretical statements recited herein. Although the best mode of carrying out the invention contemplated by the inventor(s) is disclosed, practice of the invention is not limited thereto. Accordingly, it will be appreciated by those skilled in the art that the invention may be practiced otherwise than as specifically described herein. It will be manifest that various substitutions, modifications, additions and/or rearrangements of the features of the invention may be made without deviating from the spirit and/or scope of the underlying inventive concept. It is deemed that the spirit and/or scope of the underlying inventive concept as defined by the appended claims and their equivalents cover all such substitutions, modifications, additions and/or rearrangements. All the disclosed elements and features of each disclosed embodiment can be combined with, or substituted for, the disclosed elements and features of every other disclosed embodiment except where such elements or features are mutually exclusive. Variation may be made in the steps or in the sequence of steps defining methods described herein. Although the global feedback system described herein can be a separate module, it will be manifest that the global feedback system may be integrated into the meta-system with which it is associated. The appended claims are not to be interpreted as including means-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” and/or “step for.” Subgeneric embodiments of the invention are delineated by the appended independent claims and their equivalents. Specific embodiments of the invention are differentiated by the appended dependent claims and their equivalents. REFERENCES [1] Y. Z. Hu and S. Granick, Tribol. Lett., 5, 81 (1998). [2] H. Fujita in Proceedings IEEE, Tenth Annual International Workshop on Micro Electro Mechanical Systems, Published by: IEEE Robotics and Control Division Div., New York, N.Y. (1997). Brushan, in Proceedings IEEE, The Ninth Annual International Workshop in Micro Electro Mechanical Systems, Published by: IEEE Robotics & Autom. Soc. IEEE, New York, N.Y. (1996). [3] H. G. E. Hentschel, F. Family, and Y. Braiman, Phys. Rev. Lett., 83, 104 (1999). [4] M. Heuberger, C. Drummond, and J. Israelachvili, J. Phys. Chem. B 102, 5038 (1998). [5] J. P. Gao, W. D. Luedtke, and U. Landman, J. Phys. Chem. B, 102, 5033 (1998). [6] M. G. Rozman, M. Urbakh, and J. Klafter, Phys. Rev. E 57, 7340 (1998). [7] M. G. Rozman, M. Urbakh, and J. Klafter, Phys. Rev. Lett., 77, 683 (1996), and Phys. Rev. E 54, 6485 (1996). [8] V. Zaloj, M. Urbakh, and J. Klafter, Phys. Rev. Lett., 82, 4823 (1999). [9] Y. Braiman, F. Family, H. G. E. Hentschel, C. Mak, and J. Krim, Phys. Rev. E, 59, R4737 (1999). [10] J. P. Gao, W. D. Luedtke, and U. Landman, Tribol. Lett., 9, 3 (2000). [11] J. Barhen, S. Gulati, and M. Zak, IEEE Computer, 22(6), 67 (1989). [12] M. Zak, J. Zbilut, and R. 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Elmer, Z. Phys. B, 104, 55 (1997), and Phys. Rev. B, 53, 7539 (1996). [23] E. D. Smith, M. O. Robbins, and M. Cieplak, Phys. Rev. B, 54, 8252 (1996). [24] B. J. Sokoloff, Phys. Rev. B, 52, 5318 (1995). [25] B. Brushan, J. Israelachvili, and U. Landman, Nature, 374, 607 (1995), U. Landman, W. D. Luedtke, and J. P. Gao, Langmuir, 12, 4514 (1996). [26] S. Bair, C. McCabe, and P. T. Cummings, Phys. Rev. Lett., 88, 058302 (2002). [27] Y. T. Yang, K. L. Ekinci, X. M. H. Huang, L. M. Schiavone, and M. L. Roukes, Appl. Phys. Lett., 78, 162 (2001). [28] J. Barhen, Y. Y. Braiman, and V. A. Protopopescu, Control of Friction at the Nanoscale, Physical Review Letters, 90, No. 9, pages 094301-1 through 094301-4 (Mar. 5, 2003). | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates generally to the field friction control. More particularly, the invention relates to control of friction at the micro and nano scale. 2. Discussion of the Related Art Despite great progress made during the past half century, many problems in fundamental tribology (such as the origin of friction and failure of lubrication) have remained unsolved. Moreover, the current reliable knowledge related to friction and lubrication is mainly applicable to macroscopic systems and machinery and, most likely, will be only of limited use for micro- and nano-systems. Indeed, when the thickness of the lubrication film is comparable to the molecular or atomic size, the behavior of the (film) lubricant becomes significantly different from the behavior of macroscopic (bulk) lubricant [1]. Better understanding of the intimate mechanisms of friction, lubrication, and other interfacial phenomena at the atomic and molecular scales is needed to provide designers and engineers the required tools and capabilities to monitor and control friction, reduce unnecessary wear, and predict mechanical faults and failure of lubrication in micro-electro-mechanical systems (MEMS) and nano-devices [2]. The ability to control and manipulate friction during sliding is extremely important for a large variety of technological applications. The outstanding difficulties in realizing efficient friction control are related to the complexity of the task, namely dealing with systems with many degrees of freedom under strict size confinement, and only very limited control access. Moreover, a nonlinear system driven far from equilibrium may exhibit a variety of complex spatial and temporal behaviors, each resulting in different patterns of motion and corresponding to different friction coefficient [3]. Friction can be manipulated by applying small perturbations to accessible elements and parameters of a sliding system [4-10]. Usually, these control methods are based on non-feedback controls. Recently, the groups of J. Israelachvili [4] (experimental) and U. Landman [5] (full-scale molecular dynamics computer simulation) showed that friction in thin-film boundary lubricated junctions can be reduced by coupling small amplitude (of the order of 1 Å) directional mechanical oscillations of the confining boundaries to the molecular degree of freedom of the sheared interfacial lubricating fluid. Using a surface force apparatus, modified for measuring friction forces while simultaneously inducing normal (out-of-plane) vibrations between two boundary-lubricated sliding surfaces, load- and frequency-dependent transitions between a number of “dynamical friction” states have been observed [4]. In particular, regimes of vanishingly small friction at interfacial oscillations were found. Extensive grand-canonical molecular dynamics simulations [5] revealed the nature of the dynamical states of confined sheared molecular films, their structural mechanisms, and the molecular scale mechanisms underlying transitions between them. Methods to control friction in systems under shear that begin to enable the elimination of chaotic stick-slip motion were proposed by Rozman et al [6]. Significant changes in frictional responses were observed in the two-plate model [7] by modulating the normal response to lateral motion [8]. In addition, the surface roughness and the thermal noise are expected to play a significant role in deciding control strategies at the micro and the nano-scale [9, 10]. Since feedback control methods require specific knowledge of the strength and timing of the perturbations, their application to nano-friction has been very limited. On the other hand, feedback control methods (e.g., proportional feedback) have been applied extensively in many engineering fields. All these feedback controls have been Lipschitzian. Recently, non-Lipschitzian (terminal attractor based) feedback control has been successfully implemented in first order systems such as neural networks [11, 12]. Despite their relative simplicity, phenomenological models of friction at the atomic level [10,13-16] show a fair agreement with many experimental results using either friction force equipment [7,18,19] or quartz microbalance experiments [9,17,20]. The basic equations for the driven dynamics of a one dimensional particle array of N identical particles moving on a surface are given by a set of coupled nonlinear equations of the form [16]: in-line-formulae description="In-line Formulae" end="lead"? m{umlaut over (x)} j +γ{dot over (x)} j /∂U/∂x j −∂V/∂x j +f j +η( t ), j=1, . . . N (1) in-line-formulae description="In-line Formulae" end="tail"? where x j is the coordinate of the j th particle, m is its mass, Y is the linear friction coefficient representing the single particle energy exchange with the substrate, f j is the applied external force, and η(t) is Gaussian noise. The particles in the array are subjected to a periodic potential, U(x j +a)=U(x j ), and interact with each other via a pair-wise potential V(x j −x i ), j, i=1, 2, . . . N. A system represented by Equation (1) provides a general framework of modeling friction although the amount of detail and complexity varies in different studies from simplified one dimensional models [15,16,21,22] through two dimensional and three dimensional models [17,23,24,25] to a full set of molecular dynamics simulations [25,26]. Phenomenological models of friction at the atomic level can include the following simplifications (assumptions): (i) the substrate potential is a simple periodic form, (ii) there is a zero misfit length between the array and the substrate, (iii) the same force f is applied to each particle, and (iv) the interparticle coupling is linear. The coupling with the substrate is, however, strongly nonlinear. For this case, using the dimensionless phase variables φ j =2πx j /a, the equation of motion reduces to the dynamic Frenkel-Kontorova model [16] in-line-formulae description="In-line Formulae" end="lead"? {umlaut over (φ)} j +γ{dot over (φ)}j+sin(φ j )= f +κ(φ j+1 −2φ j +φ j−1 ) (2) in-line-formulae description="In-line Formulae" end="tail"? Without control, Equation (2) exhibits four different regimes: (i) rest (no motion), (ii) periodic sliding, (iii) periodic stick-slip, and (iv) chaotic stick-slip. Different motion types are obtained by only changing the initial conditions of the particle's positions and velocities, but not the system's parameters. The average velocity of the center of mass for the “natural” (i.e., uncontrolled) motion, may take only a limited range of values, namely: (i) ν=0 for rest (no sliding), (ii) ν=f/γ for periodic sliding motion, and (iii) ν=nν 0 , where n is an integer, v 0 = 2 π nN γ π - cos - 1 f π ( κ - κ c ) 1 / 2 , for periodic stick-slip motion, [16]. | <SOH> SUMMARY OF THE INVENTION <EOH>There is a need for the following aspects of the invention. Of course, the invention is not limited to these aspects. According to an aspect of the invention, a process comprises: controlling frictional dynamics of a plurality of particles using non-Lipschitzian feedback control including: measuring a property of the plurality of particles; calculating a velocity of the plurality of particles as a function of the property; calculating a velocity deviation by subtracting the velocity of the plurality of particles from a target velocity; calculating a non-Lipschitzian (terminal attractor based) feedback control term by raising the velocity deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and imposing the non-Lipschitzian (terminal attractor based) feedback control term globally on each of the plurality of particles, wherein imposing causes a subsequent magnitude of the velocity deviation to be reduced. According to another aspect of the invention, a method comprises controlling frictional dynamics of a plurality of particles using non-Lipschitzian feedback control including determining an attribute of the plurality of particles; calculating an attribute deviation by subtracting the attribute of the plurality of particles from a target attribute; calculating a non-Lipschitzian feedback control term by raising the attribute deviation to a fractionary power 4=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and imposing the non-Lipschitzian feedback control term globally on each of the plurality of particles, wherein imposing causes a subsequent magnitude of the attribute deviation to be reduced. According to another aspect of the invention, an apparatus comprises a general dynamic system including a plurality of particles and a global feedback system that controls an attribute of the plurality particles using non-Lipschitzian control, including a characterization instrument that determines the attribute of the plurality of particles; a logic module that calculates I) an attribute deviation by subtracting the attribute of the plurality of particles from a target attribute value and II) a non-Lipschitzian feedback control term by raising the attribute deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and a tool that imposes the non-Lipschitzian feedback control term globally on each of the plurality of particles of the inertial dynamic system, wherein a subsequent magnitude of the attribute deviation is reduced. According to another aspect of the invention, a process comprises: controlling an attribute of a plurality of members of a general dynamic system using non-Lipschitzian control including: determining an attribute of the plurality of members; calculating an attribute deviation by subtracting the attribute of the plurality of members from a target attribute value; calculating a terminal attractor based control term by raising the attribute deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and imposing the terminal attractor based control term globally on each of the plurality of members of the inertial dynamic system, wherein imposing causes a subsequent magnitude of the attribute deviation to be reduced. According to another aspect of the invention, a machine comprises: a general dynamic system including a plurality of members; and a global feedback system that controls an attribute of the plurality members using non-Lipschitzian control, including: a characterization instrument that determines the attribute of the plurality of members; a logic module that calculates I) an attribute deviation by subtracting the attribute of the plurality of members from a target attribute value and II) a terminal attractor based control term by raising the attribute deviation to a fractionary power ξ=(2m+1)/(2n+1) where n=1, 2, 3 . . . and m=0, 1, 2, 3 . . . , with m strictly less than n and then multiplying by a control amplitude; and a tool that imposes the terminal attractor based control term globally on each of the plurality of members of the inertial dynamic system, wherein a subsequent magnitude of the attribute deviation is reduced. These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions and/or rearrangements may be made within the scope of the invention without departing from the spirit thereof, and the invention includes all such substitutions, modifications, additions and/or rearrangements. | 20040203 | 20100406 | 20100218 | 95403.0 | G05D1300 | 0 | NORTON, JENNIFER L | CONTROL OF FRICTION AT THE NANOSCALE | SMALL | 0 | ACCEPTED | G05D | 2,004 |
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10,771,093 | ACCEPTED | Manipulation and cutting system and method | A system for rapid manipulation and cutting that includes comprising a housing, a first cutting element, and a drive mechanism adapted to be mounted at least partly within the housing and connected to the first cutting element for imparting relative motion to the first cutting element as a combination of slicing and downward forces at the portion of the first cutting element which is adapted to contact the tissue. | 1. A system for rapid manipulation and cutting comprising: a housing, a first cutting element, a drive mechanism adapted to be mounted at least partly within the housing and operatively connected to the first cutting element for imparting relative motion to the first cutting element as a combination of slicing and downward forces at the portion of the first cutting element which is adapted to contact the tissue. 2. The system of claim 1 wherein the drive mechanism provides torque about the lateral axis of the cutting element to impart the slicing force. 3. The system of claim 2 wherein the torque about the lateral axis of the cutting element causes the first cutting element to rotate eccentrically. 4. The system of claim 1 wherein the housing is shaped substantially as a traditional scalpel. 5. The system of claim 1 wherein the housing is shaped as a handpiece. 6. The system of claim 1 wherein the drive mechanism imparts motion to the first cutting element along two of the three principal axes. 7. The system of claim 1 wherein the housing is shaped for use as a tissue manipulator for blunt force dissection. 8. The system of claim 1, wherein the cutting element is adapted for cutting tissue. 9. The system of claim 8 wherein the housing is adapted for use as a tissue probe. 10. The system of claim 9 wherein the drive mechanism advances the first cutting element relative to the housing. 11. The system of claim 1, wherein the cutting element is adapted for cutting man-made materials. 12. The system of claim 1 wherein the drive mechanism causes the housing to retreat relative to the first cutting element. 13. The system of claim 1, wherein the drive mechanism causes the first cutting element to retract relative to the housing, such that the end of the housing proximal to the first cutting element acts as a protective guard to prevent accidental contact with the first cutting element. 14. The system of claim 1 wherein the system includes means for electrocautery. 15. The system of claim 1 wherein the drive mechanism includes a pinion gear assembly. 16. The system of claim 1 wherein the drive mechanism includes a pulley drive assembly. 17. The system of claim 1 wherein the drive mechanism includes a bevel gear drive assembly. 18. The system of claim 1 wherein the drive mechanism includes a direct motor drive assembly. 19. The system of claim 1 wherein the drive mechanism includes a crank arm drive assembly. 20. The system of claim 1 wherein the first cutting element comprises a plurality of blades. 21. The system of claim 1 wherein the drive mechanism includes hydraulic means. 22. The system of claim 1 wherein the drive mechanism includes pneumatic means. 23. The system of claim 1 wherein depth of cut is variable based on the eccentricity of the first cutting element. 24. The system of claim 1 wherein ramp angle of the incision is variable based on the eccentricity of the first cutting element. 25. The system of claim 1 wherein rate of cut is variable based on the eccentricity of the first cutting element. 26. The system of claim 1 wherein reaction load is based on the design of the first cutting element. | RELATED APPLICATION This application is related to provisional U.S. Patent Application Ser. No. 60/444,326, filed Jan. 31, 2003 and having the same inventors and same title as the present application, and which is incorporated herein by reference. FIELD OF THE INVENTION The present inventions relate to devices and techniques for manipulation and cutting, and more particularly relate to eccentric rotary mechanisms for the cutting and manipulation and methods therefore. BACKGROUND OF THE INVENTION A known cutting device is the rotary slicer. Where meat is advanced into a thin blade rotating at relatively high speeds. The cutting action of this device is defined by the high slicing to chopping ratio. The resultant blade velocity vector is nearly normal to the direction of advancement. Webb, U.S. Pat. No. 5,569,285 describes a hand powered circular rotary surgical blade with a concentrically mounted cylindrical depth guard. Mueller, U.S. Pat. No. 5507764, describes a powered rotary scalpel method that is capable of developing a relatively high blade velocity relative to linear hand speed in the direction of cutting. For certain clinical procedures, it is very important to make incisions to a precisely controlled pre-determined depth. Certain known devices and methods can be found that address the need to control depth of cut such as Feldman, U.S. Pat. No. 2,882,598 and Williams, U.S. Pat. No. 4,473,076, which describe a depth limiting foot or ski element used in conjunction with a scalpel. Another known method is Urban, U.S. Pat. No. 5,860,996, that discloses a blade actuating assembly, which permits selective longitudinal linear reciprocal movement of a tissue cutting blade positioned at a distal end of a trocar assembly, from a non-deployed position to a deployed position and back to a non-deployed position. The Urban device moves in a longitudinal motion only and punches into the tissue. The known methods of tissue incision include the use of scalpels and scissors that mechanically cut the target tissue. Scalpels and scissors are useful tools when the sharp edges of the devices are clearly in view of the clinician. However, during certain procedures the sharp edge or edges may be hidden from view and prohibit the safe use of the cutting instrument. Furthermore, as the edges are hidden, it is very difficult to determine the precise depth of cut. Other methods of tissue manipulation include the dissection of different structures along natural lines by dividing or tearing the connective tissues. A blunt or sharpened obturator, such as those used with trocars, may also be used to cut and/or dissect tissue. Again, with these devices it is difficult to determine the precise depth of cut. Electrocautery devices are commonly used to surgically separate tissue. Other means of tissue manipulation include the use of energy-assisted scalpels. These devices make use of ultrasonic, laser, and radio frequency energies to assist in the manipulation of tissues. Excess energy delivered by these devices can result in collateral tissue damage, such as thermal charring and desiccation. Therefore, what is needed is a system and method for cutting that will allow precise control of the cutting edge and for rapid cutting of various materials including incision or dissection of tissues in a more controlled manner than currently exists. SUMMARY OF THE INVENTION The present invention provides a means for rapid cutting of various materials including incision or dissection of tissues in a more controlled manner than currently exists. As an aspect of one exemplary embodiment of the invention, a blade and blade actuation mechanism is provided that allows for simultaneous rotation and advancement of a cutting edge. In one arrangement of the invention, the system of the present invention provides an appropriate blend of slicing and downward force in order to cut efficiently. In one exemplary arrangement, at least two such motions are combined when cutting, thereby enhancing the efficiency of a blade element in at least some applications. Another aspect of the invention, present in at least some embodiments, is to optimize the efficiency of the cutting action by providing, for a cut along a straight path, linear motion along two of the three principal axes which beneficially affect cutting performance (slicing and downward forces) and in addition provide beneficial torque about the lateral axis, while minimizing motion and torque which is not beneficial, such as linear motion along the lateral axis or torque on the principal axes. It will be appreciated that, for a straight cut, linear motion relative to the longitudinal axis of the cutting element results in a slicing cut, and linear motion relative to the vertical axis results in a chopping or plunge cut. It will also be appreciated that a slicing motion is the result of torque. In another aspect of at least certain embodiments of the invention, a system of optimized load parameters is determined. The factors used in determining load parameters may include some or all of the: type of tissue to be incised, desired incision results including incision depth, curved or straight cutting edge, and curvilinear or straight cutting paths. The resultant optimized load parameters include, in at least certain embodiments: the resultant force vector; velocity and acceleration; and uniformity and/or consistency of load rates and velocity. Another aspect of at least some embodiments of the invention is the flexibility to use the cutting system as a tissue manipulator for blunt dissection, or as a tissue probe. Various housings, drive mechanisms and cutting element shapes are proposed, with the application impacting the particular implementation of each of these elements in each specific implementation. BRIEF DESCRIPTION OF THE FIGURES FIGS. 1A-1B illustrate a cutting assembly in accordance with the present invention mounted at the distal tip of a pen-style housing, with FIG. 1B further showing a front elevational view including an illumination source. FIGS. 2A-2B illustrate a cutting assembly in accordance with the present invention mounted on a handpiece. FIGS. 3A-3D illustrate various details of a first implementation of a cutting assembly in accordance with the invention. FIGS. 4A-4B illustrate the range of motion of a first implementation of a cutting assembly in accordance with the invention. FIGS. 5A-5B illustrate an alternative range of motion for a cutting assembly in accordance with the invention. FIGS. 6A-6D illustrate a further alternative range of motion for a cutting assembly in accordance with the invention. FIGS. 7A-7D illustrate various details of a cutting assembly having a shark-fin style blade. FIGS. 8A-8D illustrate various details of a cutting assembly having an elliptical style blade. FIGS. 9A-9D illustrate various details of a cutting assembly having an advancing round blade. FIGS. 10A-10D illustrate various details of a cutting assembly having a retreating bearing block. FIGS. 11A-11D illustrate a few of the many possible blade shapes usable with the cutting assembly of the present invention. FIGS. 12A-12C illustrate a dual blade configuration. FIGS. 13A-13B illustrate an implementation of a cutting assembly having monopolar and bipolar electrocautery, respectively. FIG. 14 illustrates a pinion gear drive assembly for actuating the blade. FIG. 15 illustrates a pulley drive assembly for actuating the blade. FIG. 16 illustrates a bevel gear drive assembly for actuating the blade. FIG. 17 illustrates a direct motor drive assembly for actuating the blade. FIG. 18 illustrates a crank arm drive assembly for actuating the blade. FIGS. 19A-19D illustrates an implementation of a cutting assembly having a cantilever spring element. FIGS. 20 illustrates a detailed perspective view of the cutting assembly of FIGS. 19A-19D. DETAILED DESCRIPTION OF THE INVENTION Referring first to FIGS. 1A and 1B, a cutting assembly 100 may be mounted at the distal tip of a pen like housing 110. The cutting assembly 100 may be used for cutting various materials. As one example, not intended to be a limitation, the cutting assembly can be used to cut commercially manufactured materials, such as paper or plastic, as well as organic material, such as animal or human tissue. The cutting assembly 100 can be made in a variety of shapes, but for the sake of clarity the cutting assembly 100 is shown to emulate the shape of a hand held cutting instrument, such as a scalpel. Furthermore, for the sake of clarity, the cutting assembly will be discussed or described herein in the context of cutting or manipulating organic tissue. However, the functional elements discussed and the methods set forth can easily be applied application relating to cutting manufactured materials, such as Kevlar or other fabrics. Considered in the context of cutting animal or human tissue, the cutting assembly 100 described herein requires less lateral tissue stabilization, thus allowing the user—for example, a clinician—to perform more precise curvilinear incisions. Furthermore, illumination elements, such as LED's 120, which are best seen in FIG. 1B may be added to enhance the clinician's view of the target tissue. An activation button 130 is typically provided to actuate the cutting assembly 100 as described in greater detail hereinafter. The housing 110 may also contain batteries, appropriate connectors, and/or a power switch, and may be disposable or reusable, depending on the particular implementation. Referring next to FIGS. 2A and 2B, a cutting element assembly 200 in accordance with the present invention may alternatively be mounted at the distal tip 210 of an elongate cannula-like structure 220 that is connected to a hand piece 230, thus forming a tool 235 suitable for Laparoscopic surgical uses, as well as any other application in which a hand piece will simplify repositioning or operation of the cutting assembly 200. Additionally, an articulating mechanism 240 may be added proximally to the cutting element 200 to enhance user-directed positioning of the tool 235, which may in turn be adjusted by articulation control 250. A trigger or other actuator 260 is provided to actuate the cutting assembly 200. The trigger 260 could be implemented as a conventional trigger, a variable speed switch, an on/off pushbutton, or any other form of actuator. The housing could also include an internal working channel, a light, a scope or a camera, again chosen based on the particular implementation. As a still further alternative, the cutting element assembly 200 in accordance with the present invention may be mounted at the distal tip of an elongate cannula like structure 220 and connected to robotic assembly. Referring next to FIGS. 3A-3D, a first implementation of a cutting assembly 300 that incorporates at least some of the features of the invention can be better appreciated. FIG. 3A illustrates in top plan view the distal end of a housing 310 and the cutting assembly 300. FIG. 3B illustrates a front elevation view of the cutting assembly 300 including a rotary cutting blade 320. FIG. 3C illustrates a side elevation view of the cutting assembly 300 and the housing 310 and FIG. 3D illustrates a cut-away view showing the cutting blade 320 and the housing 310 along the line A-A in FIG. 3A. The cutting assembly 300 includes a bearing block 330 that supports a bearing 340. An axle 350 passes through an eccentric bore in the cutting blade 320 and into the bearing 340, such that the bearing block 330 provides a low friction pivot for the cutting blade 320, provides protection from the cutting blade 320 when not actuated, and limits the amount of the cutting blade 320 that is exposed when actuated during a cutting event. Furthermore, the bearing block 330 aligns the cutting blade 320 along a desired cutting path, allows cutting motions only in beneficial directions and inhibits or prevents motion in non-beneficial directions. The degree of blade eccentricity, as defined by the location of the eccentric bore in the cutting blade 320, defines the depth of cut and the ratio of slicing motion to plunging motion. A separate external driver mechanism, discussed hereinafter in connection with FIGS. 14-18, is required to urge the blade about the pivot and to define the cutter velocity. A source of motive force, such as a motor and energy storage device, form part of the driver mechanism. The incision system of FIGS. 3A-3D operates as follows. For the sake of convenience only, a housing of the sort shown in FIG. 1 will be assumed, although the particular form of housing is not limiting. A user initiated cutting event begins by actuating an activation switch, such as the activation switch 130 of FIG. 1, which causes the driver mechanism to provide a resultant rotational movement of the cutting blade about the cutting blade pivot or axle. The cutting blade, such as the cutting baled 320 of FIGS. 3A-3D, has an eccentric bore and, hence is eccentrically mounted. Accordingly, upon rotation of the eccentrically mounted cutting blade about the pivot, the cutting edge simultaneously advances and rotates into the target tissue. In one arrangement, the eccentrically mounted circular cutting blade is. intermittently rotated at least one complete revolution as a means of cutting tissue. Many other cutting motions are possible, including reciprocating movement, partial rotation, continuous rotation, and intermittent rotation through less than a full revolution. As shown best in FIG. 3D, in a first position, the eccentrically mounted cutting blade 320 is “parked” or rotated to a safe state where no part of the cutting blade 320 extends beyond a distal tip 370 of the bearing block 330 that in order to protect and prevent accidental contact with the cutting blade 320. In this position, clinicians and the patient are protected from the cutting blade 320 by the distal tip 370 of the bearing block 370. In this first position the cutting assembly 300 may used as a tissue manipulator for blunt dissection, or as a tissue probe. By rotating the cutting blade 320 about the axle 350, the eccentric mounting of the cutting blade 320 causes a portion of the cutting blade 320 to be exposed beyond the bearing block 330, thus allowing tissue to be cut. The exact amount of the cutting blade 320 that is exposed by such rotation is determined by the location of the eccentric bore in the cutting blade 320 relative to the blade center 380, and the extent to which the cutting blade 320 is rotated about the bearing block 330, which can be better appreciated from FIGS. 4A-4B. FIG. 4A shows a side elevation view of the bearing block 330 and the cutting blade 320, and FIG. 4B shows a cut-away view of the cutting blade 320 mounting relative to the bearing block 330. In the position shown in FIGS. 4A and 4B, the eccentric mounted cutting blade 320 reaches peak extension as limited by the degree of eccentricity. In this position, the maximum depth of a cut 410 is regulated and the cutting blade 320 has achieved maximum angular velocity along the principal cutting axis in a rotational direction 420. By continued rotation of the eccentrically mounted cutting blade 320, the cutting blade 320 returns to the safe or parked state as described above. In an aspect of the invention implemented in some embodiments, the cutting blade is caused to automatically return to the parked position when the clinician or other user turns off the device by de-actuating the on/off switch, such as depressing the activation switch, or other actuator. As noted previously, the exact cutting motion may vary depending on the particular implementation and may, for example, comprise multiple uninterrupted rotations with the cutting blade starting and ending in the safe position or, as a further alternative, may comprise reciprocal rotation about the pivot as a means of cutting tissue. Referring next to FIGS. 6A-6D, an embodiment wherein a blade 600 that is capable of reciprocating motion is shown, where FIG. 6A is a side elevation view of a bearing block 610 and the blade 600, FIG. 6B shows one exemplary rotation about a bearing or pivot 620, FIG. 6C shows the blade at maximum exposure, and FIG. 6D is a cut-away view showing a drive shaft 630 affixed to the blade 600 to cause the reciprocating motion about the pivot 620. Again the amount of blade exposed is determined by the degree of eccentricity in the mounting, or the position of the pivot 620 relative to the blade center 640. In another alternative implementation, shown in FIGS. 7A-7D, a housing 700 shown in side elevation view in FIG. 7A and 7B and cut-away side views in FIGS. 7C and 7D a concentrically mounted cutting blade 710 having at least one protruding or “shark-fin” style blade element 720 is intermittently or continuously rotated a fractional revolution, a complete revolution or a multiplicity of revolutions as a means of cutting tissue. As shown in FIG. 7B, the cutting blade 710 is contained within the housing 700 while the blade element 720 is exposed. The blade element 720 may be constructed in a manner to provide a cam like cutting edge with increasing blade engagement as the blade element 720 advances, until the blade element 720 reaches maximum exposure and maximum velocity in a rotational direction 730 as shown in FIG. 7D. As an alternative to the “shark-fin” style blade element 720, the cutting blade 710 may have an elliptical shape as shown in FIGS. 8A-8D or any other non-circular shape, including rectangular, triangular, trapezoidal, and so on, such that the blade has a tip portion as a cutting surface which serves to intermittently contact the tissue during rotation. In a still further alternative implementation shown in FIGS. 9A-9D, a concentrically mounted circular blade 900 is intermittently or continuously rotated about a moveable pivot 910 housed within a protective bearing block 920. A clinician initiated cutting event is actuated by means of an energy storing mechanism 930 that provides a resultant rotational moment about the pivot 910 and a simultaneous advancement of the pivot 910 within the protective bearing block 920. Alternatively, as shown in FIGS. 10A-10D, a protective bearing block 1000 is configured to retreat relative to a blade 1010 when a driver mechanism 1030 is actuated, thus exposing the blade 1010 to the tissue. In either case, the blade rotation mechanism will be an independent element (such as a drive shaft with pinion gear, bearing element, and enclosure) that is able to move longitudinally relative to a shaft within a blade protection housing. In such an arrangement, the bearing block and protective housing may be divided, if desired, and either the blade would be moved forward or the housing moved back. Optionally, the blade may be serrated to enhance cutting specific tissues, and a few of the many examples of available blade designs suitable for use with the present invention are shown in FIGS. 11A-11D. In another implementation shown in FIGS. 12A-12C, more than one blade, such as blades 1210 and 1220, may be utilized. The blades are mounted parallel to one another and may be used to make parallel incisions or strips of tissues. Furthermore, blades may be mounted synchronously or a synchronously with respect to the axle; that is, if synchronous, the two blades rotate or advance together, and if asynchronous, the two blades move independently (at different times or rates, for example) relative to one another. Additionally, as shown in FIGS. 13A-13B, mono-polar or bi-polar electrocautery may be added for further tissue manipulations. Thus, in FIG. 13A, showing a monopolar electrocautery arrangement, a blade 1300 is polarized with a first polarity (for example, positive) relative to a housing 1310. Or, as shown in the bipolar arrangement of FIG. 13B, insulators 1320 may be mounted on either side of the blade 1300 and within the housing 1310 such that the blade 1300 has a first polarity and closely juxtaposed contacts 1330 are maintained at the opposite polarity, Referring next to FIGS. 14-18, many different means of power transmission may be employed to drive the cutting elements. The cutting elements may be driven in a rotary or oscillating mode depending on the clinical application. For example, as shown in FIG. 14, an arrangement of a pinion gear 1410 and shaft 1420 may be used with the blade 1430 notched concentrically about the axle 1440. Or, as shown in FIG. 15, a drive belt, chain or cable 1500 mounted on an input pulley 1510 and a drive pulley 1520 connected to a blade 1530 and an axle 1540 may also be used to transmit power to the blade 1530, where a drive mechanism such as a motor, air turbine or other source of motive force is connected to the axle of the input pulley 1510. As shown in FIG. 16, a rotating shaft 1600 mounted perpendicular to an axle 1610 and a blade 1620 may also be used in conjunction with a variety of well known mechanisms such as bevel gears, crown gear sets or spatial revolute-cylindrical-cylindrical-revolute couplings 1630A-B to drive the blade. As shown in FIG. 17, a motor 1700 may be directly connected to an axle 1710 and electronically controlled. Or, as shown in FIG. 18, reciprocating motion to a cutting element may also be achieved through the use of a slider crank type mechanism 1800 connected to a cam arm 1810 at a blade pivot axle 1820. Alternatively, by mounting the crank 1800 on the outside of the cam arm 1810, full rotation may be achieved. Optionally, the cutting element may also be driven by hydraulic or pneumatic means. Referring next to FIGS. 19A-19D and FIG. 20, a cutting assembly 1900 is shown having a shaft 1910, a blade 1920, and a housing 1930 with a cavity located at the end of the housing 1930 proximate to the blade 1920. A cantilever spring element 1912 is located at one end of the shaft 1910. The spring element 1912 is located proximate to and in contact with a central axle 1922 of the blade 1920 as shown in FIGS. 19A-D and FIG. 20. The central axle 1922 is positioned within the cavity of the housing 1930, such that the forward motion the blade 1920, which is cause by the linear motion of the shaft 1910, is limited as seen in cross-section view of FIG. 19D taken along the line C-C of FIG. 19C. When the central axle 1922 has reached the maximum linear travel in a direction 1950, the blade 1920 is extended the maximum distance out from the housing 1930 as shown in FIG. 19B. However, the shaft 1910 can continue its linear travel in the direction 1950. Accordingly, this linear travel of the shaft 1910 is translated into rotational motion 1960 of the blade 1920 as the shaft 1910 forces a pin 1924, which is secured to the blade 1920, to rotate about the axle 1922 until the spring element 1912 is compressed and the maximum linear motion of the shaft 1910 is reached as shown in FIG. 19C. Consequently, the rotation of the pin 1924 about the axle 1922 results in the rotational motion 1960 of the blade 1920. Thus, the linear motion 1950 of the shaft 1910 first results in extension of the blade 1920 from the housing 1930 and then rotational motion 1960 of the blade 1920 about the axle 1922. Mounting of the cutting element assembly is generally application specific. However, it is important to note that certain configurations may be useful for multiple applications. It will thus be appreciated that a new and novel design of incision system has been disclosed. Among the advantages offered by one or more of implementations of the invention are a controlled depth of cut, a retractable blade offering increasing user and patient safety, high relative velocity of cutting element permitting lower cutting forces applied by the user, and flexible mounting arrangements including articulated and more conventional mountings. Having fully disclosed a variety of implementations of the present invention, it will be appreciated by those skilled in the art that numerous alternatives and equivalents exist which do not materially alter the invention described herein. Therefore, the invention is not intended to be limited by the foregoing description, but instead only by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>A known cutting device is the rotary slicer. Where meat is advanced into a thin blade rotating at relatively high speeds. The cutting action of this device is defined by the high slicing to chopping ratio. The resultant blade velocity vector is nearly normal to the direction of advancement. Webb, U.S. Pat. No. 5,569,285 describes a hand powered circular rotary surgical blade with a concentrically mounted cylindrical depth guard. Mueller, U.S. Pat. No. 5507764, describes a powered rotary scalpel method that is capable of developing a relatively high blade velocity relative to linear hand speed in the direction of cutting. For certain clinical procedures, it is very important to make incisions to a precisely controlled pre-determined depth. Certain known devices and methods can be found that address the need to control depth of cut such as Feldman, U.S. Pat. No. 2,882,598 and Williams, U.S. Pat. No. 4,473,076, which describe a depth limiting foot or ski element used in conjunction with a scalpel. Another known method is Urban, U.S. Pat. No. 5,860,996, that discloses a blade actuating assembly, which permits selective longitudinal linear reciprocal movement of a tissue cutting blade positioned at a distal end of a trocar assembly, from a non-deployed position to a deployed position and back to a non-deployed position. The Urban device moves in a longitudinal motion only and punches into the tissue. The known methods of tissue incision include the use of scalpels and scissors that mechanically cut the target tissue. Scalpels and scissors are useful tools when the sharp edges of the devices are clearly in view of the clinician. However, during certain procedures the sharp edge or edges may be hidden from view and prohibit the safe use of the cutting instrument. Furthermore, as the edges are hidden, it is very difficult to determine the precise depth of cut. Other methods of tissue manipulation include the dissection of different structures along natural lines by dividing or tearing the connective tissues. A blunt or sharpened obturator, such as those used with trocars, may also be used to cut and/or dissect tissue. Again, with these devices it is difficult to determine the precise depth of cut. Electrocautery devices are commonly used to surgically separate tissue. Other means of tissue manipulation include the use of energy-assisted scalpels. These devices make use of ultrasonic, laser, and radio frequency energies to assist in the manipulation of tissues. Excess energy delivered by these devices can result in collateral tissue damage, such as thermal charring and desiccation. Therefore, what is needed is a system and method for cutting that will allow precise control of the cutting edge and for rapid cutting of various materials including incision or dissection of tissues in a more controlled manner than currently exists. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a means for rapid cutting of various materials including incision or dissection of tissues in a more controlled manner than currently exists. As an aspect of one exemplary embodiment of the invention, a blade and blade actuation mechanism is provided that allows for simultaneous rotation and advancement of a cutting edge. In one arrangement of the invention, the system of the present invention provides an appropriate blend of slicing and downward force in order to cut efficiently. In one exemplary arrangement, at least two such motions are combined when cutting, thereby enhancing the efficiency of a blade element in at least some applications. Another aspect of the invention, present in at least some embodiments, is to optimize the efficiency of the cutting action by providing, for a cut along a straight path, linear motion along two of the three principal axes which beneficially affect cutting performance (slicing and downward forces) and in addition provide beneficial torque about the lateral axis, while minimizing motion and torque which is not beneficial, such as linear motion along the lateral axis or torque on the principal axes. It will be appreciated that, for a straight cut, linear motion relative to the longitudinal axis of the cutting element results in a slicing cut, and linear motion relative to the vertical axis results in a chopping or plunge cut. It will also be appreciated that a slicing motion is the result of torque. In another aspect of at least certain embodiments of the invention, a system of optimized load parameters is determined. The factors used in determining load parameters may include some or all of the: type of tissue to be incised, desired incision results including incision depth, curved or straight cutting edge, and curvilinear or straight cutting paths. The resultant optimized load parameters include, in at least certain embodiments: the resultant force vector; velocity and acceleration; and uniformity and/or consistency of load rates and velocity. Another aspect of at least some embodiments of the invention is the flexibility to use the cutting system as a tissue manipulator for blunt dissection, or as a tissue probe. Various housings, drive mechanisms and cutting element shapes are proposed, with the application impacting the particular implementation of each of these elements in each specific implementation. | 20040202 | 20101130 | 20070719 | 94754.0 | A61B1732 | 0 | ANDERSON, GREGORY A | MANIPULATION AND CUTTING SYSTEM AND METHOD | SMALL | 0 | ACCEPTED | A61B | 2,004 |
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10,771,190 | ACCEPTED | Loudspeaker array system | The invention is a multi-channel loudspeaker system that provides a compact loudspeaker configuration and filter design methodology that operates in the digital signal processing domain. Further, the loudspeaker system can be designed to include drivers of various physical dimensions and can achieve prescribed constant directivity over a large area in both the vertical and horizontal planes. | 1. A loudspeaker, comprising one center driver mounted at approximately the intersection of the x-axis and y-axis of the loudspeaker, the loudspeaker having at least two drivers of a size different than the center driver mounted symmetrically along the loudspeaker in both the x-axis and y-axis about the center driver, the center drivers and the two drivers mounted symmetrically about the center driver each receive a digital output signal from at least one power D/A converter, the digital output signal having been filtered through at least one digital FIR filter. 2. The loudspeaker of claim 1, where the center driver is a tweeter. 3. The loudspeaker of claim 1, where the at least two drivers are woofers. 4. The loudspeaker of claim 1, where the at least two drivers are mid-range drivers. 5. The loudspeaker of claim 1, further comprising at least two additional drivers positioned at a point further away from the center driver than the at least two drivers. 6. The loudspeaker of claim 5, where the at least two additional drivers are woofers. 7. The loudspeaker of claim 2, where the at least two drivers are tweeters and the loudspeaker further includes at least two additional transducers, where the center driver and the at least two drivers are positioned between the two additional transducers symmetrically about the center driver. 8. The loudspeaker of claim 7, where the at least two additional transducers are mid-range speakers. 9. The loudspeaker of claim 7, where the at least two additional transducers are woofers. 10. A loudspeaker, comprising: a center tweeter positioned at a point on the loudspeaker designed as the point of origin; at least two midrange drivers positioned symmetrically about the point of origin, where the at least two midrange drivers are larger in size than the center tweeter; at least two woofers of larger size than the at least two midrange driver, the at least two woofer positioned further away from the center tweeters than the at least two midrange drivers and symmetrically arranged about the point of origin; and where the center tweeter, at least two midrange drivers and at least two woofers receive a digital output signal from at least one power D/A converter, the digital output signal having been filtered through at least one digital FIR filter. 11. The loudspeaker of claim 10, further including at least two additional tweeters, symmetrically arranged about the center tweeter and positioned between the center tweeter and the at least two midrange drivers. 12. The loudspeaker of claim 10, further including at least two additional woofers positioned near the opposing ends of the loudspeaker such that the center tweeter, at least two mid-range drivers and the at least two woofers are positioned between the at least two additional woofers. 13. A loudspeaker, the loudspeaker comprising: at least one center tweeter; at least two additional tweeters, one of the at least two additional tweeters positioned on each side of the center tweeter; at least two midrange drivers, one of the at least two midrange drivers positioned on each side of the at least two additional tweeters; at least two woofers; one of the at least two woofers positioned on each side of the at least two midrange drivers; the at least one center tweeter, at least two additional tweeters, at least two midrange drivers and the at least two woofers each receive a digital output signal from at least one power D/A converter, the digital output signal having been filtered through at least one digital FIR filter. 14. A method for designing a line array loudspeaker system, comprising the steps of: establishing the initial driver positions establishing the initial directivity target functions for the system; applying a cost minimization function based upon the initial directivity target function; and computing linear phase filter coefficients for each filter in the system. 15. The method of claim 14, where the initial driver positions are coordinates relative to the center of origin of the loudspeaker. 16. The method of claim 14, where frequency points are established on a logarithmic scale with a predetermined frequency range based upon the established initial directivity target functions. 17. The method of claim 14, where the cost minimization is function applied at the frequency points, starting with the lowest frequency increment stepwise. 18. The method of claim 14, further comprising the step of verifying the results obtained from the cost minimization function against the desired performance standards. 19. The method of claim 14, further comprising the step of adjusting the initial position of the drivers if the results obtained from the cost minimization function are not optimal, establishing new initial driver positions based upon the adjusted initial driver positions and reapplying the cost minimization function based upon the new initial driver positions. 20. The method of claim 14, where the Fourier approximation method is utilized to establish the linear phase filter coefficients. | BACKGROUND OF THE INVENTION 1. Field of the Invention This invention generally relates to a multi-way loudspeaker system and in particular to a multi-way loudspeaker system comprised of an array of multiple drivers capable of achieving high-quality sound. 2. Related Art High-quality loudspeakers for the audio frequency ranges generally employ multiple specialized drivers for dedicated parts of the audio frequency band, such as tweeters (generally 2 kHz-20 kHz), midrange drivers (generally 200 Hz-5 kHz) and woofers (generally 20 Hz-1 kHz). Because of the necessary spacing due to the physical size of the specialized drivers, which is comparable with the wavelength of the radiated sound, the acoustic outputs of the drivers sum up to the intended flat, frequency-independent response only on a single line perpendicular to the loudspeaker, usually at the so-called acoustic center. Outside of that axis, frequency responses are more or less distorted due to interferences caused by different path lengths of sound waves traveling from the drivers to the considered points in space. There have been many attempts in history to build loudspeakers with a controlled sound field over a larger space with smooth out-of-axis responses. For example, D'Appolito has presented a geometric approach to eliminate lobing errors in multi-way loudspeakers—a configuration using a center tweeter and two woofers arranged symmetrically along a vertical axis. Several loudspeaker manufacturers have adopted that approach and have even expanded upon it by using arrays of symmetrically arranged midrange drivers and woofers around one or two center tweeters. D'Appolito designs and those of the manufacturers that have adopted D'Appolito's approach utilize passive or analog crossover circuits or digital filters that emulate analog filters in a digital domain. Analog or passive crossover circuits inevitably introduce phase distortion. Further, with this design, spacing is not optimum and in general too large to completely avoid out-of-axis aberrations from an ideal smooth response. In an alternative solution, the basic design concept is to apply very steep, “brick-wall” finite impulse response (FIR) filters to avoid large transition bands, so that the errors become inaudible. However, the individual polar responses of the involved drivers may still be different at the transition point, leaving audible discontinuities. Thus, with this design solution, it may be difficult to achieve a prescribed, smooth polar behavior throughout the whole audible range. In yet another alternative, Van der Wal suggests that logarithmically spaced transducer arrays can achieve a very well controlled directivity, approximately constant over a wide frequency range, in one dimension. Some embodiments of this technique are described in U.S. Pat. No. 6,128,395. Like the previously described techniques, this design technique is limited because (i) the logarithmic spacing is prescribed only according to a given formula; (ii) the filter design is only valid for a particular case and (iii) severe errors may occur if the actual spacing deviates from logarithmic spacing, which may be unavoidable due to physical dimensions of the drivers or due to design constraints. Further, the design is restricted to one type of drivers, i.e., full-range drivers, limiting the application to public address systems. Thus, a need still exists for a loudspeaker configuration and filter design that overcomes the limitations of the prior art by providing a loudspeaker system that can contain drivers of various physical dimensions and can achieve prescribed, constant directivity over a large area in both the vertical and horizontal planes. SUMMARY The invention is a multi-way loudspeaker speaker system that can produce high-quality sound from a single, compact, line array loudspeaker that can be utilized in a traditional surround sound entertainment system typically having left and right front and rear surround sound channels and a center channel. In one embodiment, the line array includes a plurality of tweeters, mid-range drivers and woofers that are arranged in a single housing or assembled as a single unit, having sealed compartments that separate certain drivers from one another to prevent coupling of the drivers. The line array may be a single channel array having various signal paths from the input to individual loudspeaker drivers or to a plurality of drivers. Each signal path comprises digital input and contains a digital FIR filter and a power D/A converter connected to either a single driver or to multiple drivers. The performance, positioning and arrangement of the loudspeaker drivers in the line array may be determined by a filter design algorithm that establishes the coefficients for each FIR filter in each signal flow path of the loudspeaker. A cost minimization function is applied to prescribed frequency points, using initial driver positions and initial directivity target functions, which establish frequency points on a logarithmic scale within the frequency range of interest. If the obtained results from the application of the cost minimization function do not meet the performance requirements of the system, the position of the drivers may then be modified and the cost minimization function may be reapplied until the obtained results meet the system requirements. Once the obtained results meet the system requirements, the linear phase filter coefficients for each FIR filter in a signal path are computed using the Fourier approximation method or other frequency sampling method. The multi-way loudspeakers of the invention may include built-in DSP processing, D/A converters and amplifiers and may be connected to a digital network (e.g. IEEE 1394 standard). Further, the multi-way loudspeaker system of the invention, due to its compact dimensions, may be designed as a wall-mountable surround system. The multi-way loudspeaker system may employ drivers of different sizes, producing low distortion, high-power handling because specialized drivers can operate optimal in their dedicated frequency band, as opposed to arrays of identical wide-band drivers. The multi-way speaker design of the invention can also provide better control of in-room responses due to smooth out-of-axis responses. The system is further able to control the frequency response of reflected sound, as well as the total sound power, thereby suppressing floor and ceiling reflections. Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. BRIEF DESCRIPTION OF THE FIGURES The invention can be better understood with reference to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views. FIG. 1 illustrates an example of a one-dimensional six-way loudspeaker system mounted along the y-axis symmetrically to origin and a block diagram of signal flow to each of the loudspeaker drivers in the system. FIG. 2 illustrates another example implementation of a one-dimensional (1D) four-way loudspeaker system using nine loudspeaker drivers mounted along the y-axis symmetrically to origin. FIG. 3 is a flow chart of a filter design algorithm used to design the loudspeaker system. FIG. 4 is a graph illustrating the directivity target functions for angle-dependent attenuation. FIG. 5 is a graph illustrating the measurement of the amplitude frequency response of one mounted tweeter at various vertical out-of-axis displacement angles. FIG. 6 is a graph illustrating acceptable obtained results for a line array similar to the one illustrated in FIG. 1, determined along the y-axis. FIG. 7 is a graph illustrating the frequency response of the digital filters assigned to signal paths of the line array design illustrated in FIG. 1 after a cost minimization function has been applied. FIG. 8 is a graph illustrating a smoothed frequency response of the third signal path illustrated in FIG. 7 together with the frequency response of the linear FIR filter after the FIR filter coefficient has been established and applied. DETAILED DESCRIPTION FIG. 1 illustrates an example implementation of a one-dimensional (1D) multi-way loudspeaker 100 of the invention and a block diagram of the signal flow to each of the loudspeaker drivers in the system 100. As shown in FIG. 1, the multi-way loudspeaker 100 may be designed as a six-way loudspeaker having (i) a center tweeter 102 connected to a first power D/A converter 103, (ii) two additional tweeters 104 and 106 connected to a second power D/A converter 105, (iii) two midrange drivers 108 and 110 connected to a third power D/A converter 107, (iv) two midrange drivers 112 and 114 connected to fourth power D/A converter 109, (v) two woofers 116 and 118 connected to a fifth power D/A converter 111 and (vi) four woofers 120, 122, 124 and 126 connected to a sixth power D/A converter 113. The connection between the loudspeakers to each amplifier represents a different way in the multi-way loudspeaker. Thus, the loudspeaker may be designed as a single-channel multi-way loudspeaker. In FIG. 1, the drivers, also referred to as transducers, may be mounted in a housing 154 comprised of separate sealed compartments 128, 130, 132, 134, 140, 142 and 148, as indicated by separators 136, 138, 144, 146, 150 and 152. By mounting the drivers in separate sealed compartments, coupling of the neighboring drivers is minimized. Although the various compartments are visible in FIG. 1, the loudspeaker system may be designed such that the compartments are not visible to the consumer when embodied in a finished product. Compartment 128, containing woofers 120, 122, may be separated by separator 136 from compartment 132, which contains woofer 116. Similarly, compartment 130, which contains woofers 126 and 124, may be separated by separator 138 from compartment 134, which contains woofer 118. The midrange drivers 112 and 114, contained in compartments 140 and 142, respectively, may be separated from compartments 132 and 134 by separators 144 and 146, respectively. All of the tweeters 102, 104, 106, and midrange drivers 110 and 108 may also be contained in compartment 148 and separated from compartments 140 and 142 by separators 150 and 152, respectively. FIG. 1 illustrates the center tweeter 102, tweeters 104 and 106, midrange drivers 110, 108, 112, 114, 116 and 118 and low-frequency woofers 120, 122, 124 and 126 mounted linearly along the y-axis and symmetrically about the center tweeter 102. A typical arrangement may include tweeters 102, 104 and 106 of outer diameters of approximately 40 mm, midrange drivers 110, 108, 112, 114, 116 and 118 of outer diameters of approximately 80 mm, and woofers 120, 122, 124 and 126 of outer diameters of approximately 120 mm. Typically, transducer cone size may differ based on the desired application and desired size of the array. Further, the transducers may utilize neodymium magnets, although it is not necessary for the described application to utilize that particular type of magnet. The center tweeter 102 may be mounted on the y-axis at the center point 0 at the intersection between the x and y axis. The tweeters 104 and 106 may be mounted at their centers approximately +/−40 mm from the center point. The midrange drivers 110 and 108 may then be mounted at their centers approximately +/−110 mm from the center point 0. The midrange drivers 112 and 114 may then be mounted at their centers approximately +/−220 mm from the center point. The low-frequency woofers 116 and 118 may then be mounted at their centers approximately +/−350 mm from the center point. The low frequency woofers 120 and 124 may then be mounted at their centers approximately +/−520 mm from the center point. The low frequency woofers 122 and 126 may then be mounted at their centers approximately +/−860 mm from the center point. FIG. 1 also illustrates a block diagram 160 of the signal flow of the multi-way loudspeaker system. While FIG. 1 illustrates six ways 162, 164, 166, 168, 170 and 172 of signal flow, a channel may be divided into two or more ways. The signal flow comprises a digital input 174 that may be implemented using standard interface formats, such as SPDIF or IEEE1394 and their derivatives, and that can be connected to the drivers through various paths or ways, such as those illustrated in FIG. 1. Each path or way 162, 164, 166, 168, 170 and 172 may contain a digital FIR filter 176 and a power D/A converter 103, 105, 107, 109, 111 and 113 connected to either a single or to multiple loudspeaker drivers. The power D/A converters 103, 105, 107, 109, 111 and 113 may be realized as cascades of conventional audio D/A converters (not shown) and power amplifiers (not shown), or as class-D power amplifiers (not shown) with direct digital inputs. The FIR filters 176 may be implemented with a digital signal processor (DSP) (not shown). The loudspeaker drivers may be tweeters, midrange drivers or woofers, such as those illustrated. In operation, the outputs of each multiple FIR filter 176 are connected to multiple power D/A converters 103, 105, 107, 109, 111 and 113, that are then fed to multiple loudspeaker drivers 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, and 126 that are mounted on a baffle of the housing 154. More than one driver such as 120, 122, 124, and 126 may be connected in parallel to a path or way 162 containing a power D/A converter 113. FIG. 2 is another one-dimensional multi-way loudspeaker, similar to the loudspeaker of FIG. 1, except that it contains two rather than four mid-range drivers and four rather than six woofers. In particular, FIG. 2 illustrates a single channel, one-dimensional, four-way loudspeaker 200 having a center tweeter 202 encircled by two additional tweeters 204 and 206. Additionally, the loudspeaker 200 contains two midrange drivers 208 and 210 and four woofers 214, 216, 218 and 220. Tweeters 202, 204 and 206, the midrange drivers 208 and 210, and the four woofers 214, 216, 218 and 220 are all aligned linearly along the y-axis symmetrically about the center tweeter 202. Three signal paths (not shown) may be fed into compartment 226. A first path may be fed to center tweeter 202; a second path may be fed to tweeters 204 and 206; and a third path may be fed to midrange drivers 208 and 210. Just above and below compartment 226, divided by separators represented by lines 228 and 230, respectively, are compartments 222 and 224 containing woofers 214 and 218 and woofers 216 and 220 respectively. Woofers 214, 218, 216 and 220 may all be fed by a fourth path. A typical arrangement of the multi-way loudspeaker illustrated in FIG. 2 may include tweeters 202, 204 and 206 of outer diameters of approximately 40 mm, midrange drivers 208 and 210 of outer diameters of approximately 80 mm, and woofers 214, 216, 218 and 220 of outer diameters of approximately 160 mm. As previously mentioned, transducer cone size may differ based on the desired application and desired size of the array. The number of signal paths and number of any particular type of driver may also vary. The center tweeter 202 may be mounted on the y-axis at the center point 0, which is illustrated in FIG. 2 at the intersection between the x and y axis. The tweeters 204 and 206 may then be mounted at their centers approximately +/−40 mm from the center point. The midrange drivers 208 and 210 may then be mounted at their centers approximately +/−110 mm from the center point 0. The low frequency woofers 214 and 216 may then be mounted at their centers approximately +/−240 mm from the center point. The low frequency woofers 218 and 220 may then be mounted at their centers approximately +/−380 mm from the center point. FIG. 3 is a flow chart of a filter design algorithm 300 used to design the loudspeaker system of the invention. The purpose of the filter design algorithm 300 is to determine the coefficients for each FIR filter for each signal flow path of the loudspeaker. As illustrated in further detail below, the initial driver positions and initial directivity target functions are first determined 310. The initial positions or design configuration of the speaker and drivers may be designed in accordance with a number of different variables, depending upon the application, such as the desired size of the speaker, intended application or use, manufacturing constraints, aesthetics or other product design aspects. Driver coordinates are then prescribed for each driver along the main axis. Initial guesses for directivity target functions are then set, which includes establishing frequency points on a logarithmic scale within an interval of interest. The cost function is then minimized at the prescribed frequency points 312. If the results do not meet the performance requirements of the system, step 314, the position of the drivers are then modified and the cost minimization function is applied again 316. This cycle may be repeated until the results meet the requirements. Once the results meet the requirements, the linear phase filter coefficients are computed 318. Additionally computations 320 may also be made to equalize the drivers and to compensate for phase shifts and to modify beam steering. In the first step 310, the initial driver positions and initial directivity target functions are established. As previously mentioned, the number, position, size and orientation of the drivers are primarily determined by product design aspects. Once orientated, initial coordinate values may then be prescribed for initial driver coordinates p(n), n=1 . . . N for N drivers on the main axis. For example, in a one-dimensional (1D) array as illustrated in FIG. 1, N=13: p(n)=[−0.86, −0.52, −0.35, −0.22, −0.11, −0.04, 0, 0.04, 0.11, 0.22, 0.35, 0.52, 0.86]m (meters). To determine the initial directivity target functions, one must define initial guesses for directivity target functions T(f,q), which are determined based upon the desired performance of the drivers at specific angles q. FIG. 4 is a graph illustrating an example set of target functions for angle-dependent attenuation at five specific angles q. The directivity target functions specify the intended sound level attenuation in dB (y-axis) that can be measured at various frequencies at sufficiently large distance from the speaker (larger than the dimensions of the speaker) in an anechoic environment, at an angle q degrees apart from a line perpendicular to the origin (center tweeter). Frequency vector f specifies a set of frequency points, e.g. 100, on a logarithmic scale within the interval of interest, e.g. 100 Hz . . . 0.20 kHz. Angle vector q(i), i=1, . . . , Nq specifies a set of angles for which the optimization will be performed. While FIG. 4, illustrates the initial guess for directivity at five set angles: (Nq=5): q=[0,10,20,30,40]°, in most cases it may be sufficient to prescribe directivity at only two angles, i.e., Nq=2. In this instance, targeted directivity may be specified at an outer angle, for example 40 degrees, and at 0 degrees, the prescribed zero directivity on axis, i.e., q=[0,40]°. Except for the on-axis target function, the target functions at each angle, are linearly descending on a double logarithmic scale from T=0 dB at f=0 until a value T<0 dB at a specified frequency fc (e.g. fc=350 Hz), then remain constant. The on-axis target function 402 remains constant at 0 db across the entire frequency range. The target directivity functions at ten (10) degrees 404, twenty (20) degrees 410, thirty (30) degrees 412 and forty (40) degrees 414, all begin at T=0 dB and descend on a double logarithmic scale until the functions reach fc, which is represented by 350 Hz in FIG. 4, and then remain constant across the remaining frequency range of interest. After the initial driver positions and initial directivity target functions are determined, the next step 312 is to minimize the cost function F(f) at the prescribed frequency vector points f, starting with the lowest frequency increment stepwise, e.g. 100 Hz, using the obtained solution as the initial solution for the next step, respectively, by using the following equations: F ( f ) = ∑ q ( i ) [ V ( f , q ) - T ( f , q ) ] 2 , with V ( f , q ) = ∑ n = 1 N H m ( n , f , q ) · C opt ( n , f ) · exp { - j · 2 π l ( f ) · sin ( q / 180 · π ) · p ( n ) } , l = c f , c = 345 m / sec , j = - 1 where Hm(n,f,q) is a set of measured amplitude frequency responses for the considered driver n, frequency f, and angle q, normalized to the response obtained on axis (angle zero), an example of which is illustrated in FIG. 5. FIG. 5 illustrates the measured frequency responses 500 of one mounted tweeter at various vertical displacement angles normalized to on axis. In FIG. 5, line 502 represents the on-axis response, line 504 is the measured frequency response at ten degrees, line 506 is the response at twenty degrees, line 508 is the response at thirty degrees and line 510 is the measured frequency response at forty degrees, all measured at frequencies ranging between 1 kHz and 20 kHz. Further, the minimization is performed by varying real-valued frequency points of the channel filters C opt(n,f), where n is the driver index and f is frequency, within the interval [0,1]. In addition, the constraint Copt(n,f)=0, f>fo, f<fu must be fulfilled, depending on properties of particular driver n. For example, in case of a woofer, the upper operating limit is fo=1 kHz, for a tweeter, the lower limit is fu=2 kHz, for a midrange driver it could be fu=300 Hz, fo=3 kHz. The above described procedure for minimizing the cost function may be performed by a function “fminsearch,” that is part of the Matlab® software package, owned and distributed by The MathWorks, Inc. The “fminsearch” function in the Matlab software packages uses the Nelder-Mead simplex algorithm or their derivatives. Alternatively, an exhaustive search over a predefined grid on the constrained parameter range may be applied. Other methodologies may also be used to minimize the cost function. If the deviation between the obtained result and the target is sufficiently small, or acceptable as determined by one skilled in the art for the particular design application, the FIR filter coefficients for each signal path in the line array are then obtained. FIG. 6 is a graph 600 of acceptable obtained results for a line array similar to the one illustrated in FIG. 1, determined along the y-axis. The graph shows the obtained filter frequency responses V(f,q) after passing step 314 in FIG. 3. Passing means that the result met the requirements. In FIG. 6, line 602 represents the on-axis response V(f,q(1)), line 604 the frequency response at ten degrees V(f,q(2)), line 606 is the response at twenty degrees V(f,q(3)), line 608 is the response at thirty degrees V(f,q(4)) and line 610 is the measured frequency response at forty degrees V(f,q(5)), all shown at frequencies ranging between 50 Hz and 20 kHz. FIG. 7 is graph 700 illustrating the resulting frequency responses Copt(n,f) of each of the six signal paths in the line array loudspeakers system illustrated in FIG. 1 once the cost minimization function has been applied and the obtained results have been found to be sufficiently small or within the acceptable range for the desired application. The line represented by L1 or 702 is the frequency response of the first signal path which feeds the center channel tweeter 102 (FIG. 1); L2 or 704 is the frequency response of the second signal path which feeds the tweeters 104 and 106 (FIG. 1); L3 or 706 is the frequency response of the third signal path which feeds the mid-range drivers 110 and 108 (FIG. 1); L4 or 708 is the frequency response of the forth signal path which feeds mid-range drivers 114 and 116 (FIG. 1); L5 or 710 is the frequency response of the fifth signal path which feeds woofers 116 and 118 and L6 or 812 is the frequency response of the sixth signal path which feeds woofers 120, 122, 124 and 126. If the deviation between the obtained results and the target are not acceptable for the particular design application, i.e. or are too large, the driver positions or geometry, and/or parameters q(i) and fc of the target function T(f,g) (see FIG. 3) should then be modified. Once modified, the cost minimization function should again be applied and the process should be repeated until obtained results and the target are sufficiently small or with an acceptable range for the application. Once the driver positions and driver geometry are positioned such that the algorithm as shown in FIG. 3 yields results within an acceptable range of the target function, the FIR filter coefficients for each signal path n=1 . . . N must then be determined, depicted as step 318 in FIG. 3. One method for determining the FIR coefficients is to use a Fourier approximation (frequency sampling method), to obtain linear phase filters of given degree. When applying the Fourier approximation, or other frequency sampling method, a degree should be chosen such that the approximation becomes sufficiently accurate. The Fourier approximation method may be performed by a function “firls,” that is part of the Matlab® software package, owned and distributed by The MathWorks, Inc. Similar methodologies may be used to minimize the cost function by implementing in other software systems. FIG. 8 is a graph 800 illustrating a frequency response of one signal path 802 which is identical to L 4 or 708 of FIG. 7, together with the frequency response of the linear phase FIR filter 804 after the FIR filter coefficients have been obtained in accordance with the method described above. Additionally, modifications can be made to the FIR filters to equalize the measured frequency response of one or more drivers (in particular tweeters, midranges). The impulse response of such a filter can be obtained by well-known methods, and must be convolved with the impulse response of the linear phase channel filter when determining the FIR filter coefficients, as described above. Further, the voice coils (acoustic centers of the drivers) may not be aligned. To compensate for this, appropriate delays can be incorporated into the filters by adding leading zeros to the FIR impulse response. Further, delays may be added to each channel in accordance with the following equation: Δt=p/c·sin α, (p=driver coordinates, c=345 m/sec) where the main sound beam, which is otherwise perpendicular to the main axis, can be steered to a desired direction with angle α. Further, the geometry of the one-dimensional layout may be modified such that the design process can be carried out in two dimensions, i.e., along both the x and y-axis, as described above by making the geometry symmetrical. Due to the symmetry, the same directivity characteristics will result along the y-axis (vertical), except of a higher corner frequency. While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of this invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention generally relates to a multi-way loudspeaker system and in particular to a multi-way loudspeaker system comprised of an array of multiple drivers capable of achieving high-quality sound. 2. Related Art High-quality loudspeakers for the audio frequency ranges generally employ multiple specialized drivers for dedicated parts of the audio frequency band, such as tweeters (generally 2 kHz-20 kHz), midrange drivers (generally 200 Hz-5 kHz) and woofers (generally 20 Hz-1 kHz). Because of the necessary spacing due to the physical size of the specialized drivers, which is comparable with the wavelength of the radiated sound, the acoustic outputs of the drivers sum up to the intended flat, frequency-independent response only on a single line perpendicular to the loudspeaker, usually at the so-called acoustic center. Outside of that axis, frequency responses are more or less distorted due to interferences caused by different path lengths of sound waves traveling from the drivers to the considered points in space. There have been many attempts in history to build loudspeakers with a controlled sound field over a larger space with smooth out-of-axis responses. For example, D'Appolito has presented a geometric approach to eliminate lobing errors in multi-way loudspeakers—a configuration using a center tweeter and two woofers arranged symmetrically along a vertical axis. Several loudspeaker manufacturers have adopted that approach and have even expanded upon it by using arrays of symmetrically arranged midrange drivers and woofers around one or two center tweeters. D'Appolito designs and those of the manufacturers that have adopted D'Appolito's approach utilize passive or analog crossover circuits or digital filters that emulate analog filters in a digital domain. Analog or passive crossover circuits inevitably introduce phase distortion. Further, with this design, spacing is not optimum and in general too large to completely avoid out-of-axis aberrations from an ideal smooth response. In an alternative solution, the basic design concept is to apply very steep, “brick-wall” finite impulse response (FIR) filters to avoid large transition bands, so that the errors become inaudible. However, the individual polar responses of the involved drivers may still be different at the transition point, leaving audible discontinuities. Thus, with this design solution, it may be difficult to achieve a prescribed, smooth polar behavior throughout the whole audible range. In yet another alternative, Van der Wal suggests that logarithmically spaced transducer arrays can achieve a very well controlled directivity, approximately constant over a wide frequency range, in one dimension. Some embodiments of this technique are described in U.S. Pat. No. 6,128,395. Like the previously described techniques, this design technique is limited because (i) the logarithmic spacing is prescribed only according to a given formula; (ii) the filter design is only valid for a particular case and (iii) severe errors may occur if the actual spacing deviates from logarithmic spacing, which may be unavoidable due to physical dimensions of the drivers or due to design constraints. Further, the design is restricted to one type of drivers, i.e., full-range drivers, limiting the application to public address systems. Thus, a need still exists for a loudspeaker configuration and filter design that overcomes the limitations of the prior art by providing a loudspeaker system that can contain drivers of various physical dimensions and can achieve prescribed, constant directivity over a large area in both the vertical and horizontal planes. | <SOH> SUMMARY <EOH>The invention is a multi-way loudspeaker speaker system that can produce high-quality sound from a single, compact, line array loudspeaker that can be utilized in a traditional surround sound entertainment system typically having left and right front and rear surround sound channels and a center channel. In one embodiment, the line array includes a plurality of tweeters, mid-range drivers and woofers that are arranged in a single housing or assembled as a single unit, having sealed compartments that separate certain drivers from one another to prevent coupling of the drivers. The line array may be a single channel array having various signal paths from the input to individual loudspeaker drivers or to a plurality of drivers. Each signal path comprises digital input and contains a digital FIR filter and a power D/A converter connected to either a single driver or to multiple drivers. The performance, positioning and arrangement of the loudspeaker drivers in the line array may be determined by a filter design algorithm that establishes the coefficients for each FIR filter in each signal flow path of the loudspeaker. A cost minimization function is applied to prescribed frequency points, using initial driver positions and initial directivity target functions, which establish frequency points on a logarithmic scale within the frequency range of interest. If the obtained results from the application of the cost minimization function do not meet the performance requirements of the system, the position of the drivers may then be modified and the cost minimization function may be reapplied until the obtained results meet the system requirements. Once the obtained results meet the system requirements, the linear phase filter coefficients for each FIR filter in a signal path are computed using the Fourier approximation method or other frequency sampling method. The multi-way loudspeakers of the invention may include built-in DSP processing, D/A converters and amplifiers and may be connected to a digital network (e.g. IEEE 1394 standard). Further, the multi-way loudspeaker system of the invention, due to its compact dimensions, may be designed as a wall-mountable surround system. The multi-way loudspeaker system may employ drivers of different sizes, producing low distortion, high-power handling because specialized drivers can operate optimal in their dedicated frequency band, as opposed to arrays of identical wide-band drivers. The multi-way speaker design of the invention can also provide better control of in-room responses due to smooth out-of-axis responses. The system is further able to control the frequency response of reflected sound, as well as the total sound power, thereby suppressing floor and ceiling reflections. Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. | 20040202 | 20120501 | 20050818 | 68049.0 | 0 | LEE, PING | LOUDSPEAKER ARRAY SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,771,204 | ACCEPTED | Silicon nitride insulating substrate for power semiconductor module | An aspect of the present invention provides a power module for automotive switching applications including a plurality of semiconductor chips and a unitary silicon nitride substrate. The plurality of semiconductor chips are attached to the silicon nitride substrate and the substrate is configured to have a thermal coefficient of expansion substantially the same as the plurality of semiconductor chips. | 1. A power module for switching applications comprising: a plurality of semiconductor chips; a housing wherein the housing has a cavity for receiving the plurality of semiconductor chips; a unitary silicon nitride substrate configured to mate with the housing and having a thermal coefficient of expansion substantially the same as the plurality of semiconductor chips and wherein the plurality of semiconductor chips are attached to the silicon nitride substrate; and a conductive layer including a circuit pattern attached to the silicon nitride substrate. 2. The power module according to claim 1, wherein the substrate is between 0.5 and 1.5 mm thick. 3. The power module according to claim 1, wherein at least one of the plurality of semiconductor chips is a IGBT semiconductor chip. 4. The power module according to claim 1, wherein the at least one of the plurality of semiconductor chips is a FRED semiconductor chip. 5. The power module according to claim 4, wherein the conductive layer is a copper layer having a thickness of between 0.1 and 0.5 mm. 6. The power module according to claim 5, wherein the copper layer is actively brazed to the substrate. 7. The power module according to claim 5, wherein the plurality of semiconductor chips are wire bonded to the copper layer. 8. The power module according to claim 5, wherein the plurality of semiconductor chips are soldered to the copper layer. 9. The power module according to claim 1, wherein the substrate includes holes for fastening the substrate to the housing. 10. The power module according to claim 1, wherein the substrate is fastened to a heat sink. 11. A power module for switching applications comprising: at least one IGBT semiconductor chip; at least one FRED semiconductor chip; a housing wherein the housing has a cavity for receiving the at least one IGBT and the at least one FRED semiconductor chips; a unitary silicon nitride substrate configured to have a thermal coefficient of expansion substantially the same as the first and second semiconductor chips; and wherein the at least one IGBT and the at least one FRED semiconductor chips are attached to the silicon nitride substrate; and a conductive layer including a circuit pattern attached to the silicon nitride substrate. 12. The power module according to claim 11, wherein the substrate is between 0.5 and 1.5 mm thick. 13. The power module according to claim 11 wherein the conductive layer is a copper layer between 0.1 and 0.5 mm thick. 14. The power module according to claim 13, wherein the copper layer is actively brazed to the substrate. 15. The power module according to claim 13, wherein the at least one IGBT and the at least one FRED semiconductor chips are wire bonded to the copper layer. 16. The power module according to claim 13, wherein the at least one IGBT and the at least one FRED semiconductor chips are soldered to the copper layer. 17. The power module according to claim 11, wherein the substrate includes holes for fastening the substrate. 18. The power module according to claim 11, wherein the substrate is fastened to a heat sink. 19. The power module according to claim 11, further comprising a housing fastened to the substrate. 20. A method for manufacturing a power module comprising the steps of: attaching a conductive layer including a circuit pattern to a unitary silicon nitride substrate; attaching a plurality of semiconductor chips to the silicon nitride substrate; attaching the plurality of semiconductor chips to the conductive layer using wire bonds; attaching power terminals to the conductive layer; attaching a plastic housing to the silicon nitride substrate; applying a silicone gel in a cavity formed by the plastic housing and the silicon nitride substrate; applying epoxy resin in the cavity formed by the plastic housing and the silicon nitride substrate; attaching a lid of the housing to the power module. 21. The method according to claim 20, wherein the conductive layer is attached by active brazing. 22. The method according to claim 20, wherein the plurality of semiconductor chips are attached to the conductive layer using a high temperature soft solder. 23. The method according to claim 22, wherein the plurality of semiconductor chips are attached to the conductive layer using solder consisting essentially of 95% Pb, 2.5% Sn, and 2.5% Ag. 24. The method according to claim 20, wherein the plurality of semiconductor chips includes at least one IGBT semiconductor chip. 25. The method according to claim 20, wherein the plurality of semiconductor chips includes at least one FRED semiconductor chip. 26. The method according to claim 20, wherein the wire bonds are aluminum wire bonds. 27. The method according to claim 20, wherein the power terminals are attached using a low temperature soft solder. 28. The method according to claim 27, wherein the power terminals are attached to the conductive layer using solder consisting essentially of 60% Pb and 40% Sn. 29. The method according to claim 20, further comprising the step of attaching fast-on terminals by manual soldering. 30. The method according to claim 20, wherein the plastic housing is attached using an epoxy adhesive. 31. The method according to claim 20, wherein the lid of the housing is attached using an epoxy adhesive. | BACKGROUND 1. Field of the Invention The present invention generally relates to an electronic power module. More specifically, the invention relates to electronic power modules having a silicon nitride substrate for automotive applications. 2. Description of Related Art Power modules including IGBT (insulated gate bipolar transistor), FREDs (fast recovery epitaxial diode), MOSFETs, and other semiconductor chips have been used in automotive applications for many years. The power modules must be able to operate at a high ambient temperature. In addition, the high power dissipation required by the power modules further increases the temperature variations affecting the components of the power module. With such large temperature swings, the difference in thermal expansion of the components in the power module often causes reliability issues. A major cause of reliability issues is due to warping of the substrate. Substrate warpage of even 250 microns across a die can present a problem. Typically, the printed solder paste thickness is only 125 microns thick. Therefore, a warpage of 250 microns would not allow the die to be placed flat on the solder print. Many manufacturers have used smaller powered dies on multiple substrates to address the warpage problem. For example, four 50 Amp chips have been used on four separate substrates rather than a single 200 Amp chip on a single substrate as desired. However, using multiple substrates requires the use of a metal base plate which adds cost and complexity to the module. In addition, a thermal expansion mismatch between the die and substrate can also cause mechanical stress in the electrical connections thereby compromising reliability. Repetitive high power switching applications tend to increase temperature and shorten the life expectancy of solid-state power devices. One application that subjects the power module to repetitive high power switching is the electric automobile application, especially when the electric vehicle is driven in a city where stopping at a red light every few minutes is typically required. The power required to accelerate a vehicle from a standing start is substantially greater than the power required to maintain a constant speed. Another example is an electric assisted automotive power steering system while in a parking maneuver. Quite often in this situation the tires come in contact with the curb. Tires contacting the curb drives the power assist system to provide maximum output until the controlling processor reacts to the “stall load” demand by reducing the amount of assist. Automotive applications typically require very high peak power demands followed by a short cool down in a repetitive cycle. To address the power dissipation problem caused by the frequent high power switching, power modules were designed with multiple chips and multiple substrates, as shown in FIG. 1. FIG. 1 shows a IGBT module 10 with a first semiconductor chip 12 and a second semiconductor chip 26. The first semiconductor chip 12 is attached to a ceramic substrate 14. The ceramic substrate 14 includes a copper layer 16 that includes a circuit pattern (not shown). The first semiconductor chip 12 is attached to the copper layer 16 by wire bonds 20. In addition, substrate 14 has a copper layer 22 which can be used for grounding or thermal dissipation. The copper layer 22 is attached to a base plate 24. The base plate 24 acts as a foundation or support for all of the semiconductor components. The second semiconductor chip 26 is attached to a separate second ceramic substrate 28. The second ceramic substrate 28 has a copper layer 30 which includes a circuit pattern (not shown). Second semiconductor chip 26 is electrically connected to the circuit pattern of copper layer 30 by wire bonds 32. The second substrate 28 also has a copper layer 34 for grounding, mechanical balancing, and dissipating heat. Copper layer 34 is also attached to base plate 24. Attached to the circuit pattern on copper layers 16, 30 are leads 42, 44, 46, 48 for connecting the IGBT module with other devices or circuits external of module 10. To improve the thermal dissipation and protect the components of module 10 a silicone gel 40 is disposed over the semiconductor chips 12, 26 to cover and protect them. In addition, an epoxy resin 38 is disposed on top of silicone gel 40 to further protect and seal module 10. The epoxy resin case 36 is attached to the base plate 24 and provides additional structural protection for the components of IGBT module 10. The multiple ceramic substrates 14 and 28 help to mitigate thermal expansion problems. However, the multiple ceramic substrates also complicate the manufacture of module 10, add additional weight, and add significant cost to the module. In view of the above, it is apparent that there exists a need for an improved power module for automotive applications that is easier to manufacture, weighs less, and has lower component costs. SUMMARY In satisfying the above need, as well as overcoming the enumerated drawbacks and other limitations of the related art, the present invention provides a power module for automotive switching applications including a plurality of semiconductor chips and a unitary silicon nitride substrate. The plurality of semiconductor chips are attached to the silicon nitride substrate and the substrate is configured to have a thermal coefficient of expansion substantially the same as the plurality of semiconductor chips. In another aspect of the invention, at least one of the plurality of semiconductor chips is an IGBT semiconductor chip. In another aspect of the invention, at least one of the plurality of semiconductor chips is a FRED semiconductor chip. In yet another aspect of the invention the substrate includes a copper layer. The copper layer is between 0.1 and 0.5 mm thick and is actively brazed to the substrate. The plurality of semiconductor chips are attached to the copper layer by solder and connected to the circuit pattern of the copper layer by wire bonds. In yet another aspect of the invention the substrate includes holes for fastening the substrate. The substrate may be fastened to a heat sink. Further, the housing of the power module is fastened to the substrate. Further aspects, features and advantages of this invention will become readily apparent to persons skilled in the art after a review of the following description, with reference to the drawings and claims that are appended to and form a part of this specification. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side cutaway view of a prior art module using a conventional design; and FIG. 2 is a side cutaway view of an IGBT module according to the present invention. DETAILED DESCRIPTION Referring now to the drawings, a power module embodying the principles of the present invention is illustrated therein and designated at 10. As its primary components, power module 10 includes a first semiconductor chip 52, a second semiconductor chip 60, and a substrate 54. The first and second semiconductor chip 52, 60 are both attached to a single substrate 54. The substrate 54 is made of silicon nitride (Si3N4) and is between 0.5 and 1.5 mm thick. One method of attaching semiconductor chips 52, 60 to the substrate 54 is by soldering. The thermal coefficient of expansion of the silicon nitride substrate 54 is configured to match the coefficient of expansion of the first and second semiconductor chips 52, 60 thereby eliminating the need for multiple ceramic substrates while reducing the stress on the components and connections. Both Si3N4 substrate 54 and semiconductor chips 52 and 60 have thermal coefficients of expansion of 3 ppm/C. By matching the coefficients of expansion dies of 200 Amps or higher can be accommodated which was previously not possible. A conductive layer shown as copper layer 56 is attached to substrate 54. The copper layer 56 is between 0.1 and 0.5 mm thick and is preferably actively brazed onto the substrate 54. The copper layer 56 also includes a circuit pattern. The first semiconductor chip 52 is connected to the circuit pattern of copper layer 56 by wire bonds 58. Similarly, the second semiconductor chip 60 is connected to copper layer 56 by wire bonds 64. The substrate 54 also has a second copper layer 66 for grounding, mechanical balancing, and heat dissipation purposes. The substrate 54 also serves as the foundation or support for power module 50. The substrate 54 also includes holes 82 for fastening power module 50 to a heat sink 84, other device or a circuit board. Leads 72, 74, 76, and 78 are attached or soldered to solder pads on the circuit pattern of copper layer 56 for electrically connecting power module 50 to external circuits or devices. To protect the components of power module 50, a silicone gel 68 is disposed over and surrounds the electrical components of power module 50. In addition, an epoxy resin 70 is placed on top of silicone gel 68 to further seal and protect the components. An epoxy resin case 80 is attached to the substrate 54 and further protects the components of power module 50 by providing structural stability to the module. Therefore, silicon nitride has a thermal conductivity of 70 watts/M-C almost twice the value of alternative substrates. The single silicon nitride substrate 54 provides better thermomechanical continuity allowing better heat dissipation while also providing better resistance to warpage thereby increasing reliability. Further, the manufacture of the device is simplified using a single substrate and the substrate can be used to replace metal base plate (shown in FIG. 1). Therefore the cost and weight of the module is reduced by eliminating the multiple ceramic substrates and the base plate of the prior art designs. Another aspect of the invention provides a method of manufacture for a power semiconductor module. The method begins with a unitary silicon nitride substrate. A copper layer including a circuit pattern is actively brazed onto the silicon nitride substrate. Semiconductor chips are attached to the silicon nitride substrate. In another aspect of the invention, at least one IGBT and at least one FRED semiconductor chips are attached to the silicon nitride substrate. The semiconductor chips are attached to the silicon nitride substrate using a high temperature soft solder, such as 95 Pb/2.5Sn/2.5Ag. Each of the semiconductor chips are wire bonded to the printed circuit pattern using aluminum wire. Power terminals are attached to the copper layer using a low temperature soft solder, such as 60 Pb/40Sn. Additional terminals are attached to the copper layer by manual soldering. Sides of the plastic housing are attached to the silicon nitride substrate using an epoxy adhesive. A layer of silicone gel is applied into the cavity formed by the plastic housing to cover and protect the semiconductor chips and wire bonds. An epoxy resin is applied into the cavity formed by the substrate and the plastic housing on top of the silicone gel. A plastic lid of the housing is attached by an epoxy adhesive. As a person skilled in the art will readily appreciate, the above description is meant as an illustration of implementation of the principles this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from spirit of this invention, as defined in the following claims. | <SOH> BACKGROUND <EOH>1. Field of the Invention The present invention generally relates to an electronic power module. More specifically, the invention relates to electronic power modules having a silicon nitride substrate for automotive applications. 2. Description of Related Art Power modules including IGBT (insulated gate bipolar transistor), FREDs (fast recovery epitaxial diode), MOSFETs, and other semiconductor chips have been used in automotive applications for many years. The power modules must be able to operate at a high ambient temperature. In addition, the high power dissipation required by the power modules further increases the temperature variations affecting the components of the power module. With such large temperature swings, the difference in thermal expansion of the components in the power module often causes reliability issues. A major cause of reliability issues is due to warping of the substrate. Substrate warpage of even 250 microns across a die can present a problem. Typically, the printed solder paste thickness is only 125 microns thick. Therefore, a warpage of 250 microns would not allow the die to be placed flat on the solder print. Many manufacturers have used smaller powered dies on multiple substrates to address the warpage problem. For example, four 50 Amp chips have been used on four separate substrates rather than a single 200 Amp chip on a single substrate as desired. However, using multiple substrates requires the use of a metal base plate which adds cost and complexity to the module. In addition, a thermal expansion mismatch between the die and substrate can also cause mechanical stress in the electrical connections thereby compromising reliability. Repetitive high power switching applications tend to increase temperature and shorten the life expectancy of solid-state power devices. One application that subjects the power module to repetitive high power switching is the electric automobile application, especially when the electric vehicle is driven in a city where stopping at a red light every few minutes is typically required. The power required to accelerate a vehicle from a standing start is substantially greater than the power required to maintain a constant speed. Another example is an electric assisted automotive power steering system while in a parking maneuver. Quite often in this situation the tires come in contact with the curb. Tires contacting the curb drives the power assist system to provide maximum output until the controlling processor reacts to the “stall load” demand by reducing the amount of assist. Automotive applications typically require very high peak power demands followed by a short cool down in a repetitive cycle. To address the power dissipation problem caused by the frequent high power switching, power modules were designed with multiple chips and multiple substrates, as shown in FIG. 1 . FIG. 1 shows a IGBT module 10 with a first semiconductor chip 12 and a second semiconductor chip 26 . The first semiconductor chip 12 is attached to a ceramic substrate 14 . The ceramic substrate 14 includes a copper layer 16 that includes a circuit pattern (not shown). The first semiconductor chip 12 is attached to the copper layer 16 by wire bonds 20 . In addition, substrate 14 has a copper layer 22 which can be used for grounding or thermal dissipation. The copper layer 22 is attached to a base plate 24 . The base plate 24 acts as a foundation or support for all of the semiconductor components. The second semiconductor chip 26 is attached to a separate second ceramic substrate 28 . The second ceramic substrate 28 has a copper layer 30 which includes a circuit pattern (not shown). Second semiconductor chip 26 is electrically connected to the circuit pattern of copper layer 30 by wire bonds 32 . The second substrate 28 also has a copper layer 34 for grounding, mechanical balancing, and dissipating heat. Copper layer 34 is also attached to base plate 24 . Attached to the circuit pattern on copper layers 16 , 30 are leads 42 , 44 , 46 , 48 for connecting the IGBT module with other devices or circuits external of module 10 . To improve the thermal dissipation and protect the components of module 10 a silicone gel 40 is disposed over the semiconductor chips 12 , 26 to cover and protect them. In addition, an epoxy resin 38 is disposed on top of silicone gel 40 to further protect and seal module 10 . The epoxy resin case 36 is attached to the base plate 24 and provides additional structural protection for the components of IGBT module 10 . The multiple ceramic substrates 14 and 28 help to mitigate thermal expansion problems. However, the multiple ceramic substrates also complicate the manufacture of module 10 , add additional weight, and add significant cost to the module. In view of the above, it is apparent that there exists a need for an improved power module for automotive applications that is easier to manufacture, weighs less, and has lower component costs. | <SOH> SUMMARY <EOH>In satisfying the above need, as well as overcoming the enumerated drawbacks and other limitations of the related art, the present invention provides a power module for automotive switching applications including a plurality of semiconductor chips and a unitary silicon nitride substrate. The plurality of semiconductor chips are attached to the silicon nitride substrate and the substrate is configured to have a thermal coefficient of expansion substantially the same as the plurality of semiconductor chips. In another aspect of the invention, at least one of the plurality of semiconductor chips is an IGBT semiconductor chip. In another aspect of the invention, at least one of the plurality of semiconductor chips is a FRED semiconductor chip. In yet another aspect of the invention the substrate includes a copper layer. The copper layer is between 0.1 and 0.5 mm thick and is actively brazed to the substrate. The plurality of semiconductor chips are attached to the copper layer by solder and connected to the circuit pattern of the copper layer by wire bonds. In yet another aspect of the invention the substrate includes holes for fastening the substrate. The substrate may be fastened to a heat sink. Further, the housing of the power module is fastened to the substrate. Further aspects, features and advantages of this invention will become readily apparent to persons skilled in the art after a review of the following description, with reference to the drawings and claims that are appended to and form a part of this specification. | 20040203 | 20060328 | 20050804 | 98292.0 | 0 | ABRAHAM, FETSUM | SILICON NITRIDE INSULATING SUBSTRATE FOR POWER SEMICONDUCTOR MODULE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,771,377 | ACCEPTED | Extracorporeal blood treatment machine | The invention relates to an extracorporeal blood treatment machine in which a blood circuit (3) is equipped with an inlet line leading to a filtration unit (2) and with an outlet line (3b) from the filtration unit; a fluid circuit comprises an inlet line (4a) leading to the filtration unit and an outlet line (4b) from the filtration unit so as to allow a fluid taken from a primary container (5) to circulate within the filtration unit, thus enabling the treatment of the patient's blood. There is further an infusion line (6) acting on the outlet line of the blood circuit, which is supplied by an auxiliary fluid container (7). The inlet line of the fluid circuit is equipped with at least an infusion branch (8) acting on the outlet line of the blood circuit so as to enable the intensive therapy machine to manage therapies with large exchange of fluids. | 1. Extracorporeal blood treatment machine comprising: at least one filtration unit; a blood circuit having at least one inlet line leading to the filtration unit and one outlet line from the filtration unit; a fluid circuit having at least one inlet line leading to the filtration unit and one outlet line from the filtration unit; at least one infusion line connected to the blood circuit; at least one primary fluid container connected so as to supply the inlet line of the fluid circuit; at least one auxiliary fluid container for supplying said infusion line, characterized in that the inlet line of the fluid circuit comprises at least one infusion branch connected to the blood circuit. 2. Machine according to claim 1, characterized in that the infusion line is connected to the outlet line of the blood circuit. 3. Machine according to claim 1, characterized in that the infusion branch is connected to the outlet line of the blood circuit. 4. Machine according to claim 1, characterized in that the inlet line of the fluid circuit comprises means for conveying fluid, for instance at least one inlet line pump, for controlling the fluid flow. 5. Machine according to claim 4, characterized in that the infusion branch of the fluid circuit is placed downstream from said inlet line pump with respect to a direction of circulation of the fluid. 6. Machine according to claim 1, characterized in that the infusion branch of the fluid circuit and the infusion line are equipped with a common end length letting into the blood circuit. 7. Machine according to claim 1, characterized in that it further comprises a gas separating device engaged on the outlet line of the blood circuit. 8. Machine according to claims 6 and 7, characterized in that the intake end length infuses the fluid directly into said separating device. 9. Machine according to claim 1, characterized in that it further comprises means for conveying the fluid, for instance an infusion pump, for controlling the fluid flow in the infusion line. 10. Machine according to claims 6 and 9, characterized in that the common intake end length is placed downstream from the infusion pump with respect to a direction of infusion. 11. Machine according to claim 1, characterized in that the inlet line of the fluid circuit comprises an intake branch leading to the filtration unit, said fluid circuit further comprising selecting means for determining the percentages of fluid flow within the infusion branch and the intake branch. 12. Machine according to claim 11, characterized in that the selecting means are placed near a branching of the fluid circuit splitting up into intake branch and infusion branch. 13. Machine according to claim 11, characterized in that the selecting means can be positioned at least between a first operation condition in which they allow the passage of fluid in the intake branch and block the passage in the infusion branch, and a second operating condition in which they allow the passage of fluid in the infusion branch and block the passage in the intake branch. 14. Machine according to claim 1, characterized in that it further comprises an auxiliary pre-infusion line connected to the inlet line of the blood circuit. 15. Machine according to claim 14, characterized in that the auxiliary pre-infusion line comprises means for conveying fluid, for instance at least one auxiliary pre-infusion pump, for controlling the fluid flow. 16. Machine according to claim 14, characterized in that it further comprises at least a secondary fluid container for supplying said auxiliary pre-infusion line. 17. Machine according to claim 1, characterized in that the blood circuit comprises means for conveying fluid, for instance at least one blood pump, for controlling the flow of blood in the circuit. 18. Machine according to claims 14 and 17, characterized in that the pre-infusion line operates upstream from the blood pump with respect to a direction of blood circulation. 19. Machine according to claim 16, characterized in that the secondary fluid container supplying the auxiliary pre-infusion line is designed to contain an anticoagulant. 20. Machine according to claim 1, characterized in that the infusion line further comprises at least a pre-infusion branch connected to the inlet line of the blood circuit. 21. Machine according to claims 17 and 20, characterized in that the pre-infusion branch operates downstream from the blood pump with respect to a direction of blood circulation. 22. Machine according to claims 9 and 20, characterized in that the pre-infusion branch is placed downstream from the infusion pump with respect to a direction of infusion. 23. Machine according to claim 20, characterized in that the infusion line comprises a post-infusion branch connected to the outlet line of the blood circuit, said infusion line further comprising other selecting means for determining the percentage of flow within the post-infusion branch and the pre-infusion branch. 24. Machine according to claim 23, characterized in that the other selecting means are placed near a branching (26) of the infusion line splitting up into pre-infusion branch and post-infusion branch. 25. Machine according to claim 23, characterized in that the other selecting means can be positioned at least between a first operation condition in which they allow the passage of fluid in the infusion branch and block the passage in the post-infusion branch, and at least a second operating condition in which they allow the passage of fluid in the post-infusion branch and block the passage in the infusion branch. 26. Machine according to claims 6 and 23, characterized in that the pre-infusion branch starts from the post-infusion branch upstream from the common end length with respect to a direction of infusion. 27. Machine according to claim 1, characterized in that it further comprises a collection container engaged to the outlet line of the fluid circuit. 28. Machine according to claim 1, characterized in that the outlet line of the fluid circuit further comprises means for circulating fluid, for instance an outlet line pump, for controlling the flow within the fluid circuit. 29. Machine according to claim 1, characterized in that it further comprises means for determining the weight of at least said primary fluid container. 30. Machine according to claim 1, characterized in that it further comprises means for determining the weight of at least said auxiliary fluid container. 31. Machine according to claim 1, characterized in that it further comprises means for determining the weight of at least said secondary fluid container. 32. Machine according to claim 1, characterized in that it further comprises means for determining the weight of at least said collection container. 33. Machine according to any of the claims 29, 30, 31, 32, characterized in that said means for determining the weight comprise at least four respective scales. 34. Machine according to claim 1, characterized in that it further comprises a processing unit acting on the blood circuit, on the fluid circuit and on the infusion line, thus allowing their respective flows to be controlled. 35. Machine according to claim 34, characterized in that the processing unit acts on the auxiliary pre-infusion line. 36. Machine according to claim 34, characterized in that the processing unit acts by controlling the inlet line pump and/or the infusion pump and/or the blood pump and/or the outlet line pump (28) and/or the auxiliary pre-infusion pump. 37. Machine according to claims 11, 23 and 34, characterized in that the processing unit acts on the selecting means and/or on the other selecting means. 38. Machine according to claim 34, characterized in that the processing unit is input with a signal concerning the weights detected by the determining means, and in particular a weight signal detected by scales. 39. Machine according to claim 34, characterized in that the processing unit acts on the pressure sensors and possibly on the bubble sensor and on the flow closing element, and for instance also on the device for administering heparin. 40. Extracorporeal blood treatment machine comprising: at least one filtration unit; a blood circuit having at least one inlet line leading to the filtration unit and one outlet line from the filtration unit; a fluid circuit having at least one inlet line leading to the filtration unit and one outlet line from the filtration unit; at least one primary fluid container connected so as to supply the inlet line of the fluid circuit; at least one infusion line acting on the outlet line of the blood circuit; at least one auxiliary fluid container for supplying said infusion line; and an auxiliary pre-infusion line acting on the inlet line of the blood circuit, characterized in that the inlet line of the fluid circuit comprises at least one infusion branch connected to the blood circuit, said infusion line further comprising at least one pre-infusion branch connected to the inlet line of the blood circuit. 41. Hydraulic circuit designed for extracorporeal blood treatment machines according to any of the preceding claims, comprising: a blood circuit having at least an inlet line to be associated to a filtration unit, and an outlet line to be connected to said filtration unit; a fluid circuit having at least an inlet line to be associated to the filtration unit, and an outlet line to be connected to the filtration unit, the inlet line of the fluid circuit being destined to be connected to at least a primary fluid container; at least an infusion line acting on the outlet line of the blood circuit, said infusion line being designed to be supplied by at least an auxiliary fluid container; characterized in that the inlet line of the fluid circuit comprises at least an infusion branch connected to the outlet line of the blood circuit. 42. Hydraulic circuit according to claim 41, characterized in that it further comprises an auxiliary pre-infusion line acting on the inlet line of the blood circuit and having at least a pre-infusion branch connected to the inlet line of the blood circuit. 43. Integrated module for blood treatment comprising: a support element; at least one filtration unit engaged to the support element; and a fluid distribution circuitry associated to the support element and cooperating with the filtration unit so as to carry out the hydraulic circuits as in claim 41. 44. Module according to claim 43, characterized in that the support element comprises a main body and a support structure associated to the main body and placed laterally with respect to the latter. 45. Module according to claim 44, characterized in that the support structure comprises a positioning fin having a given number of main seats in which respective tubes of the fluid distribution circuit to be associated to the support element have to be engaged. 46. Module according to claim 43, characterized in that the fluid distribution circuitry comprises at least an inlet line of a fluid circuit fastened to the support element so as to define at least a U-arranged tube length with respect to said support element, which shall cooperate operationally with a respective pump. 47. Module according to claims 44 and 46, characterized in that the inlet line is fastened to the main body on the support structure, at least an inlet length of the fluid circuit being engaged in a main seat of the positioning fin and to a respective engagement connector, at least an outlet length (49) of the fluid circuit being engaged in a main seat of the positioning fin and to the respective engagement connector. 48. Module according to claim 47, characterized in that the inlet and outlet lengths engaged to the connectors and to the main seats are placed in a rectilinear arrangement and are parallel one to the other. 49. Module according to claim 47, characterized in that the outlet length has a branching splitting up into intake branch conveying the fluid to the filtration unit, and into infusion branch conveying the fluid to a blood circuit. 50. Module according to claim 49, characterized in that the branching splitting up into infusion branch and intake branch is defined on an engagement connector. 51. Module according to claim 49, characterized in that the infusion branch is secured to an auxiliary seat and to another main seat. 52. Module according to claim 49, characterized in that the infusion branch and the intake branch, when engaged to the support structure, are placed in a rectilinear arrangement and are parallel one to the other. 53. Module according to claim 43, characterized in that the fluid distribution circuitry comprises at least an infusion line secured to the support element so as to define at least a U-arranged tube length with respect to said support element, said tube length being designed to cooperate operationally with a respective pump. 54. Module according to claims 44 and 53, characterized in that the infusion line is fastened to the main body on the support structure, at least an outlet length of the infusion line being engaged to a main seat of the positioning fin and to a respective engagement connector. 55. Module according to claim 54, characterized in that the outlet length has a branching splitting up into pre-infusion branch conveying fluid to an inlet line of a blood circuit, and into post-infusion branch conveying fluid to an outlet line of the blood circuit. 56. Module according to claim 55, characterized in that the branching splitting up into pre-infusion branch and post-infusion branch is defined on an engagement connector. 57. Module according to claim 55, characterized in that the pre-infusion branch is secured to an auxiliary seat and to another main seat. 58. Module according to claim 56, characterized in that the pre-infusion branch and the post-infusion branch, when engaged to the support structure, are placed in a rectilinear arrangement and are parallel one to the other. 59. Machine according to claim 11, incorporating an integrated module according to claim 52, characterized in that the selecting means comprise a moving element acting on the infusion branch and/or on the intake branch on the support structure engaged to the main body for selectively blocking or allowing the passage of fluid in said infusion branch or intake branch. 60. Machine according to claim 59, characterized in that said moving element is mounted directly onto the machine body. 61. Machine according to claim 23 incorporating an integrated module according to claim 58, characterized in that the other selecting means comprise a moving element acting on said pre-infusion branch and/or on said post-infusion branch for selectively blocking or enabling the passage of fluid in said pre-infusion branch or in said post-infusion branch. 62. Machine according to claim 61, characterized in that said moving element is mounted directly onto the machine body. | BACKGROUND OF THE INVENTION The present invention relates to an extracorporeal blood treatment machine and to an integrated treatment module that can be used on said machine. The object of the invention can be used for instance in intensive therapy machines which can carry out a plurality of different blood treatments. Extracorporeal treatments generally consists in taking blood from the patient, in treating said blood when it is outside the patient's body and then in re-circulating the blood thus treated. The treatment typically consists in removing from the blood unwanted and/or dangerous substances, as well as excess liquid in patients who cannot autonomously carry out said operations, such as for instances patients suffering from temporary or permanent kidney problems. For instance, it may be necessary to add or remove substances from blood, to keep a correct acid/base ratio or also to remove fluid excess from the body. The extracorporeal treatment is generally obtained by removing blood from the patient, by letting the blood flow within a filtration unit where a semipermeable membrane ensures the exchange of suitable substances, molecules and fluids. Generally though not necessarily, said exchange is carried out by letting a given biological fluid ensuring the aforesaid exchanges pass in counter-current and within a secondary chamber of the filtration unit. It should be noted that currently used machines can enable different types of blood treatment. In the ultrafiltration treatment the substances and fluids to be eliminated are removed by convection from the blood, pass through the semipermeable membrane and are led towards the aforesaid secondary chamber. In hemofiltration treatments part of the molecules, substances and fluids present in the blood pass through the membrane by convection as in the ultrafiltration treatment, although further necessary elements are added to the blood; typically a suitable fluid is infused directly into the blood before or after the latter passes through the filtration unit and anyhow before it is carried back into the patient. In haemodialysis treatments a fluid containing material to be transferred into the blood is introduced into the secondary chamber of the filtration unit. The unwanted material flows through the semipermeable membrane from the blood into the secondary fluid and the desired substances/molecules from the secondary fluid can pass through the membrane as far as the blood. In hemodiafiltration treatments the blood and the secondary fluid exchange their respective substances/molecules as in haemodialysis and, in addition, a fluid is infused into the blood as in haemofiltration treatments. Obviously, in order to carry out each of said extracorporeal blood treatments, the blood has to be removed from a patient's vein or artery, suitably circulated in the machine and then re-introduced into the patient. As is also known, blood treatment machines for intensive therapy have to be ready as fast as possible for an immediate use for any possible emergency. Obviously, to this purpose the machine must not require either preliminary sanitizing operations or long pre-assembling operations of the various components for the various therapies. As is known, intensive therapy machines are present on the market and are currently used, in which a blood circuit comprises a line for taking blood from the patient, which carries said blood to a filtration cartridge, and an outlet line from the filtration cartridge, which carries the treated blood back into the patient's body. The machine is then equipped with a circuit for the passage of dialysis fluid; also said circuit has an intake line leading into the filtration unit, which is supplied by a sterile bag containing the dialysis liquid, and has also an outlet line enabling the passage of a fluid which has received by convection/diffusion the dangerous substances and molecules from the blood towards a collection bag for their subsequent removal. Said machine is further equipped with an infusion line allowing with suitable doses—to transfer directly into the blood upstream from the filtration unit the content of another liquid bag, thus adding the necessary products into the blood. A known intensive therapy machine is further equipped with a suitable syringe containing for instance heparin as blood anticoagulant, the latter being added to the blood taken from the patient so as to avoid the creation of dangerous clots within the circuit. The structure and circuitry mentioned above are generally defined by a single integrated module attached to the machine body. It is evident that in order to enable the immediate use of the machine, the fluid bags referred to above have to be present and already sterile, so as to be directly and easily connected to their respective tubes, the latter also being sterile and disposable. The machine is further equipped with a suitable control unit managing the flow of fluids by means of suitable peristaltic pumps and respective sensors associated to the circuit. It is evident that by suitably setting the control unit said machine can selectively carry out one or more of the extracorporeal blood treatments described above (i.e. ultrafiltration, haemofiltration, haemodialysis and haemodiafiltration). The machine described above, though being today quite a vanguard device for extracorporeal blood treatments in intensive therapies, has proved to be susceptible of several improvements. In particular, a first intrinsic drawback in intensive therapy machines is related to the limited availability of fluids for operations involving the exchange of substances by convection/diffusion within the filter and for pre- or post-infusions into the blood line. Said limitation is obviously related to the necessary use of prepackaged sterile fluid bags typically containing 6 kg of dialysis liquid. It is evident that the pre-established fluid amount to be used imposes some limitations, in particular in the case of therapies with large exchange of fluids, which would sometimes be extremely suitable in emergency cases. On the other hand, it is not possible to use larger fluid amounts in intensive therapies since suitably treated water taken from the water network cannot be used as exchange fluid in short times; indeed, this would involve long operations for installing the devices for in-line preparation of sterile liquids; moreover, it is not possible to use bags with higher amounts of liquids due to the obvious problems involving transport and management of said containers by the personnel. Another problem of known intensive therapy machines consists in achieving an optimal management of the administration of anticoagulant substances which are necessary for a good working of the machine. In particular, today known intensive therapy machines cannot manage effectively the use of regional anticoagulation methods, such as for instance citrate-based methods, since the use of said techniques requires the administration of further solutions recovering the blood ion balance before carrying the treated blood back into the patient's body. SUMMARY OF THE INVENTION Under these circumstances the present invention aims at solving basically all the drawbacks referred to above. A first technical aim of the invention is to provide physicians with the possibility to manage therapies with large exchange of fluids using an intensive therapy machine where, in any case, fluids are housed in small-size containers. A further aim of the present invention is to be able to manage intensive therapies by using regional anticoagulation techniques, i.e. acting on the blood only in the extracorporeal circuit, without having to limit pre-infusion upstream from the filtration unit. Moreover, an aim of the present invention is to enable the substantial separation of the use of regional anticoagulation techniques from the infusion of fluids for carrying out the necessary therapeutic exchange (by convection or diffusion). Finally, an auxiliary aim of the present invention is to provide an machine ensuring quite simple and reliable loading and installing operations, further enabling the complete control of the therapy cycles that are carried out. These and other aims, which shall be evident in the course of the present description, are basically achieved by an extracorporeal blood treatment machine as described in the appended claims. Further characteristics and advantages will be clearer from the detailed description of a preferred though not exclusive embodiment of an extracorporeal blood treatment machine according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS This description will be given below with reference to the appended tables, which are provided as a mere guidance and are therefore not limiting, in which: FIG. 1 shows schematically a hydraulic circuit to be used in an intensive therapy machine in accordance with the present invention; FIG. 2 shows an integrated module comprising a support element and a portion of the fluid distribution circuitry, to be used in intensive therapy machines in accordance with the present invention; and FIG. 3 shows an machine body in accordance with the invention. DETAILED DESCRIPTION With reference to the figures mentioned above, the numeral 1 globally refers to a machine for extracorporeal blood treatment, in particular for intensive therapies. As can be inferred from the appended table 1, the machine consists of a blood circuit 3, which takes blood from a patient, for instance by means of a catheter introduced into a vein or artery of said patient, and through at least an inlet line 3a takes said blood, for instance continuously, to a filtration unit 2. Then the blood passes through a primary chamber of said filtration unit 2 and through an outlet line 3b the treated blood is carried back to the patient. The connection with an auxiliary pre-infusion line 18 is provided immediately downstream from the blood collecting zone on the inlet line 3a. In particular, the machine is equipped with at least a secondary fluid container or bag 20 for supplying the pre-infusion line 18; by using corresponding means for conveying fluid, in the example shown comprising an auxiliary pre-infusion pump 19, for instance a peristaltic pump, it is possible to control the fluid flow within said line by introducing said fluid directly into the blood by means of a direct connection to the inlet line 3a. Generally, the secondary fluid container 20 can house a suitable biological fluid for a pre-infusion, however said bag 20 can also contain an anticoagulant, generally causing a regional anticoagulation so as to ensure a particular working of the machine as shall be explained below in further detail. After defining a direction of blood circulation 22 from the inlet line 3a towards the filtration unit and from the latter through the outlet line 3b towards the patient, a known blood pressure sensor 34, which shall not be described in further detail, is placed immediately downstream from the auxiliary pre-infusion line 18. The blood circuit 3 therefore comprises means for conveying fluid, i.e. in this particular case at least a blood pump 21 for controlling and managing the suitable blood flow in the circuit. Also the blood pump 21 is generally a peristaltic pump. Following the direction of blood circulation 22, there is then a device 35 for administering an anticoagulant, for instance a syringe containing suitable doses of heparin. The blood then passes through another pressure sensor 36 controlling the correct flow within the blood circuit. After passing through a main chamber of the filtration unit 2, where the suitable exchanges of substances, molecules and fluids occur by means of a semipermeable membrane, the treated blood enters the outlet line 3b first passing though a gas separating device (generally air) 12 commonly known as “bubble trap”, designed so as to ensure the detection and removal of substances or air bubbles present in the blood. The treated blood getting out of the separating device 12 then passes through an air bubble sensor 37 verifying the absence of said dangerous formations within the treated blood that has to be re-introduced in the patient's blood circulation. Immediately downstream from the bubble sensor 37 there is an element 38 which, in case of alarm, can block the blood flow towards the patient. In particular, should the bubble sensor 37 detect the presence of anomalies in the blood flow, the machine through the element 38 (be it a tap, a clamp or similar) would be able to block immediately the passage of blood so as to avoid any consequence to the patient. Downstream from said element 38 the treated blood is then carried back to the patient undergoing therapy. The extracorporeal blood treatment machine shown above is then equipped with a fluid circuit 4, which is also provided with at least an inlet line 4a leading into the filtration unit 2 and with an outlet line 4b from the filtration unit. At least a primary fluid container 5 is designed to supply the inlet line 4a of the fluid circuit 4 (generally the primary fluid container 5 shall consist of a bag containing a suitable dialysis liquid). The inlet line 4a then comprises means for conveying fluid such as at least a pump 9 (in the embodiment shown a peristaltic pump) for controlling the flow of liquid from the bag 5 and for defining a direction of circulation 10. Downstream from the pump 9 in the direction of circulation 10 there is a branching 17 splitting the fluid circuit 4 up into an intake branch 15 and an infusion branch 8. In particular, the infusion branch 8 is connected to the outlet line 3b of the blood circuit 3. In other words, by means of said infusion branch 8 it is possible to obtain a post-infusion directly in the blood line using the content of the primary fluid container 5. Conversely, the intake branch 15 conveys the fluid directly to the filtration unit and in particular to a secondary chamber of said unit. The fluid circuit 4 is further equipped with selecting means 16 for determining the percentages of fluid flow within the infusion branch 8 and the intake branch 15. Generally said selecting means 16, usually placed near the branching 17, can be positioned at least between a first operating condition in which they allow the passage of fluid in the intake branch 15 and block the passage in the infusion branch 8, and a second operating condition in which they allow the passage of fluid in the infusion branch 8 and block the passage in the intake branch 15. In other words, said selecting means 16 can consist of a valve element operating on the fluid circuit 4 by alternatively blocking the passage of fluid in either branch. It is also evident that it might be provided for suitable selectors, which are able to establish a priori the amount of liquid that has to pass through both branches simultaneously. It will also be possible to vary the percentages of fluid in either branch as a function of time and of the pre-established therapies. The dialysis liquid through the intake branch 15 gets into a secondary chamber of the filtration unit 2. In particular, the primary chamber through which the blood flow passes is separated from the secondary chamber through which the dialysis liquid passes by means of a semipermeable membrane ensuring the suitable passage of the dangerous substances/molecules and of fluid from the blood towards the dialysis liquid mainly by means of convection and diffusion processes, and also ensuring through the same principles the passage of substances/molecules from the dialysis liquid towards the blood. The dialysis fluid then gets into the outlet line 4b and passes through a suitable pressure sensor 39 whose function is to control the working of said line. Then there are means for conveying fluid, for instance a suction pump 28 controlling the flow in the outlet line 4b within the fluid circuit 4. Also said pump will generally be a peristaltic pump. The fluid to be eliminated then passes through a blood detector and is conveyed into a collection container or bag 27. Further analyzing the particular circuit of the machine according to the invention, note the presence of at least another infusion line 6 acting on the outlet line 3b of the blood circuit 3. In particular, the infusion fluid is taken from at least an auxiliary container 7 and is sent directly to the outlet line 3b of the blood circuit 3 through means for conveying fluid, generally an infusion pump 13 controlling its flow (in the example a peristaltic pump). In particular and as can be observed in the appended figure, the infusion liquid can be introduced directly into the gas separating device 12. As can also be inferred, the infusion branch 8 of the fluid circuit 4 and the infusion line 6 are equipped with a common end length 11 letting into the blood circuit 3. Said intake end length 11 is placed downstream from the infusion pump 13 with respect to a direction of infusion 14 and carries the fluid directly into the bubble trap device 12. Further referring to the diagram in FIG. 1, one can notice the presence within the infusion line 6 of at least a pre-infusion branch 23 connected to an inlet line 3a of the blood circuit 3. In further detail, downstream from the infusion pump 13 with respect to the direction of infusion 14, there is a branching 26 splitting the infusion line 6 up into pre-infusion branch 23 and post-infusion branch 24. The pre-infusion branch 23, in particular, carries the fluid taken from the bag 7 on the inlet line 3a of the blood circuit downstream from the blood pump 21 with respect to the direction of circulation 22. Conversely, the post-infusion branch 24 is connected directly to the common end length 11. The infusion line 6 further comprises selecting means 25 for determining the percentage of liquid flow to be sent to the post-infusion branch 24 and to the pre-infusion branch 23. The selecting means 25 placed near the branching 26 can be positioned between at least a first operating condition in which they allow the passage of fluid in the pre-infusion branch 23 and block the passage in the post-infusion branch 24, and at least a second operating condition in which they allow the passage of fluid in the post-infusion branch 24 and block the passage in the pre-infusion branch 23. Obviously, as in the case of the selecting means 16 present on the fluid circuit 4, also the other selecting means 25 will be able to determine the percentage of fluid that has to pass in each of the two branches and to possibly vary it in time in accordance with the planned therapies. Moreover, the selecting means 16 and the other selecting means 25 will generally though not necessarily be of the same nature. The machine is then equipped with means 29 for determining at least the weight of the primary fluid container 5 and/or of the auxiliary fluid container 7 and/or of the secondary fluid container 20 and/or of the collection container 27. In particular, said means 29 comprise weight sensors, for instance respective scales 30, 31, 32 and 33 (at least an independent one for each fluid bag associated to the machine). In particular, there will be at least 4 of said scales, each pair being independent from the other, and each one measuring the respective weight of a bag. It should then be pointed out that there is a processing unit or CPU 40 acting on the blood circuit 3 and in particular on the pressure sensor 34, on the blood pump 21, on the device 35 for heparin infusion, on the other pressure sensor 36, and on the device for detecting the presence of air bubbles 37 and on its respective closing element 38. Said CPU 40 has also to control the fluid circuit 4 and, in particular, shall be input with the data detected by the scales 30 and concerning the weight of the bag 5 and shall act on the pump 9, on the selecting means 16, on the pressure sensor 39, then on the suction pump 28 and shall eventually receive the data detected by the scales 33 whose function is to determine the weight of the collection container 27. The CPU 40 shall also act on the infusion line 6 checking the weight of the auxiliary container 7 (checked by the scales 31) and will be able to control both the infusion pump 13 and the other selecting means 26. Eventually, the CPU 40 shall also act on the auxiliary pre-infusion line 18 detecting the weight of the secondary fluid container 20 by means of the scales 32 and suitably controlling the pump 19 according to the treatments to be carried out. Reminding that the above description has been made with the sole purpose of describing the whole of the hydraulic circuit of the extracorporeal blood treatment machine, here is a short description of the working of the device. Once the whole hydraulic circuit and the filtering unit 2 have been correctly associated to the machine so that the various peristaltic pumps engage the respective lengths of tubes and that all the sensors have been suitably positioned, and the various bags containing the various fluids have been associated to the corresponding liquid supply/intake lines, and the blood circuit has been connected to a patient's artery/vein, the initial circulation of blood within its circuit is enabled. Therefore, according to the kind of therapy that has been set, the extracorporeal blood treatment machine is automatically started and controlled by the processing unit 40. If the patient undergoes an ultrafiltration treatment, as well as the blood pump 21 the suction pump 28 connected to the outlet line of the fluid circuit 4 is started, so as to take by convection a fluid excess in the patient by means of the filtration unit. Conversely, if the therapy that has been set comprises a haemofiltration treatment, as well as the blood pump 21 and the suction pump 28 for taking fluids by convection also the pump 9 on the inlet line of the fluid circuit 4 and the selecting means 16 placed so as to enable a post-infusion are started. Also the infusion line 6 shall be used so as to enable a further addition of liquids to the post-infusion or to enable a suitable pre-infusion. Conversely, if the treatment involves haemodialysis, the pumps 9 and 28 of the fluid circuit 4 shall be started and the selecting means 16 shall be positioned so as to ensure the passage of the dialysis liquid only towards the filtration unit 2 so as to take substances and/or molecules and/or liquids by diffusion and possibly by convection if the transmembrane pressure through the filtration unit is other than zero. Eventually, if a haemodiafiltration treatment has to be carried out, beyond the blood pump 21 the fluid circuit and therefore the pumps 9 and 28 shall be started, so as to ensure a circulation of the liquid within the filtration unit 2 and also the pump 14 of the infusion line 6 shall be started so as to ensure a pre- or post-infusion. It will be possible to set up therapies comprising one or more of the treatments referred to above. In all the treatments described above, possibly except the ultrafiltration treatment, it will be possible to use the auxiliary pre-infusion line for introducing an anticoagulant and/or a suitable infusion liquid into the blood. The anticoagulant can also be administered by means of the suitable device 35 designed for the introduction of heparin into blood. Concerning this it should be pointed out that the machine according to the invention is designed to receive various kinds of syringes according to the amount of anticoagulant to be administered. Obviously, it is the control unit 40 that, being connected to the various devices, sensors, pumps and being input with the data on weight from the scales, is able—once it is set—to control and automate the whole working of the machine. In further detail, it is possible to set the flows of the various pumps present on the machine in accordance with the therapy or therapies to be started. Obviously, the setting of said flows results in an amount of fluid taken from the patient (weight loss), which will generally be given by the difference between the weight of the liquid that has been collected in the bag 27 and of the liquid circulated in the circuit through the primary fluid container 5, the auxiliary fluid container 7 and the secondary fluid container 20. In particular, in accordance with the data received by the control unit coming from the various scales (and the theoretical flow rates fixed on each pump of therapy/treatment carried out) the control unit 40 shall control the means for circulating fluid in the various lines by suitably varying the thrust exerted by the various pumps 9, 13, 19, 21 and 28. In particular, the signals coming from the scales referred to above 30, 31, 32, 33 are used by the control unit 40 for determining the weight of the particular fluid introduced into the line or collected. In order to determine the amount of fluid released or collected in a particular bag or container the control unit 40 compares at regular intervals (the greater the flows the smaller the intervals) the actual weight of the container with the desired weight (which is a direct function of the desired flow for each pump and of the time interval between each control step ΔW=Q Δt). The desired weight can be calculated as a function of the required flow (stored in a suitable storage unit of the computer) and of the time elapsed from the beginning of the treatment. If the actual weight and the desired weight differ from each other, the control unit acts on the corresponding pump so as to reduce, and possibly cancel, said difference. In other words, during each cycle not an absolute weight variation, but only the variation in the time interval is taken into consideration to correct the latter. The control unit takes into consideration variations in the difference starting from the last comparison, so as to avoid oscillations of the actual flow around the desired flow. Reminding that the above description has been carried out with the sole purpose of providing a general view of the blood treatment machine and of the hydraulic circuit thereto associated, it should be noted that generally the whole machine shall comprise a body 58 (see in particular FIG. 3) designed to integrate all instruments and devices to be used several times in different treatments on one or more patients. In particular, the machine body 58, beyond the whole electronic control circuitry (processing unit 40, data input and reading display, pressure sensors 34, 36, 39, . . . ) shall also have on its front surface the blood pump 21, the fluid pump 9, the infusion pump 13 and the auxiliary pre-infusion pump 19. Conversely, the parts of the machine that are designed to be used only once for each treatment on the patient, generally in the course of an intensive therapy, shall be housed in a corresponding disposable integrated module 41 to be attached directly onto the machine body 58. As shown in FIG. 2, the integrated module 41 for blood treatment has a support element 42 consisting of a main body 52 and of a supporting structure 44 associated, for instance as one piece, to the main body and placed laterally with respect to the latter. Said integrated module further comprises a fluid distribution circuitry 43 (represented only partially in the appended FIG. 2) associated to said support element 42 and cooperating with the filtration unit 2 so as to carry out the hydraulic circuit previously described. In particular, it is possible to note how the main body 52 defines a housing compartment designed to receive the respective U-arranged lengths of tubes of the circuitry, which are kept in position so as to be ready to cooperate with the respective peristaltic pumps housed by the machine body 58. As can be observed, the blood circuit 3 and in general the inlet line 3a of the blood circuit 3 is fastened by means of connectors to a side wall of the main body 52, in the same way as also the inlet line 4a of the fluid circuit 4 and the outlet line 4b of the fluid circuit 4 are secured to the main body 52. Also the infusion line 6 and the auxiliary pre-infusion line 18 are secured to the main body 52 (see again FIG. 2). All the portions of lines referred to above are secured to the support element 42 so as to define at least a corresponding U-arranged length of tube with respect to said support element 42 and so that each of said U-lengths can cooperate with the corresponding peristaltic pump housed in the machine body. Going into further constructive details, it can be noted how the support structure 44 comprises a positioning fin 45 provided with a given number of main seats 46a, 46b, 46c, 46d and 46e suitably placed so that respective tubes of the fluid distribution circuit 43 associated to the support element can be engaged therein. As can be further observed, the inlet line 4a of the fluid circuit 4 is fastened to the main body 52 on the support structure 44. As a matter of fact, at least an inlet length 47 is kept in position by the support structure 44 by means of a main seat 46c of the positioning fin 45 and by a corresponding connector 48 defined on the main body. The outlet length 49 of the fluid circuit 4 is engaged in its turn with the respective engagement connector 50 and with the main seat 46a of the positioning fin 45. As can be noted from the arrangement shown, the inlet and outlet lengths 47 and 49 engaged to their respective connectors 48, 50 and with the main seats 46c and 46a are placed in a substantially rectilinear arrangement and are parallel one to the other. It should then be pointed out that the outlet length 49 has a branching 17 splitting up into intake branch 15 designed to convey the fluid to the filtration unit, and infusion branch 8 designed to convey the fluid to the blood circuit 3. Said branching 17 cannot be seen in FIG. 2 since it is defined by the engagement connector 50 on the opposite side with respect to the one shown in said figure. In other words, the connector 50 has a basically T shape, whose two outlets are connected to the intake branch 15 and to the infusion branch 8. The infusion branch 8 is further secured to an auxiliary seat 51 of the support structure and to another main seat 46b. When engaged the infusion branch 8 and the intake branch 15 are placed in a rectilinear arrangement and are parallel one to the other. Also the infusion line 6 is fastened to the main body 52 on the support structure 44. At least an outlet length 53 of the infusion line 6 is engaged to a main seat 46d of the positioning fin and to a respective engagement connector 54. Analogously to the above description, also the outlet length 53 of the infusion line 6 has a branching 26 splitting up into pre-infusion branch 23 designed to convey the fluid to the inlet line 3a of the blood circuit 3, and post-infusion branch designed to convey the fluid to the outlet line 3b of the blood circuit 3. Here again the branching 26 is not shown in FIG. 2 since it is defined by the T-shaped connector 54, one of whose outlets can be seen only on the opposite side with respect to the one shown. The pre-infusion branch 23 is secured to an auxiliary seat 55 of the support structure and to another main seat 46e of the fin 45. Said arrangement enables to have pre-infusion branch 23 and post-infusion branch 24 in rectilinear configuration and parallel one to the other. It should now be observed that the selecting means 16 previously defined act by enabling or blocking the passage of fluid in the infusion branch 8 and/or in the intake branch 15 exactly on the rectilinear lengths defined on the support structure 44. In particular, said selecting means 16 can be defined by suitable cams or clamps. The example of embodiment shown provides for a moving element 56, which as a result of its movement blocks either the infusion branch 8 or the intake branch 15. Said moving element 56 is generally mounted directly onto the machine body 58 and has been shown with a mere explicative purpose and with a hatched line in the appended FIG. 2. Wholly similarly, the other selecting means 25 can comprise a moving element 57 acting on the pre-infusion branch 23 or on the post-infusion branch 24 for selectively blocking or enabling the passage of fluid. Here again said moving element 57 has been shown by way of example in FIG. 2; however, it should be noted that generally said element is mounted directly onto the machine body 58. The invention has important advantages. It is obvious that the use of a hydraulic circuit enabling a passage of the dialysis fluid within the filtration unit or selectively towards a post-infusion by using the same liquid coming from the primary fluid bag 5, allows to manage therapies with a large volume of fluids, particularly in intensive therapy machines where anyhow said fluids are housed in small bags. As a matter of fact, it will be possible to carry out a pre- and/or post-infusion into the blood line using the fluid of the primary container 5 and of the auxiliary container 7, thus carrying out for instance a more intense ultrafiltration. Moreover, the presence of a branching also on the infusion line allows to manage therapies with regional anticoagulation techniques without limiting the possibilities of dialysis pre-filter infusion in any way. When regional anticoagulation techniques are used, such as for instances the use of citrates, it is always necessary, before carrying the treated blood back into the patient, to administer to the latter suitable substances (for instance calcium) for recovering the ion balance in the blood. It is obvious that the elimination/balance of the anticoagulant substances should be carried out downstream from the filtration unit, for instance by means of the post-infusion line. In the machine according to the invention, however, in order to balance the ions in the returned blood it will be possible to use directly the fluid circuit by introducing a suitable reagent into the primary fluid bag 5 and by using the inlet line 4a for carrying out the post-infusion through the infusion branch 8. The infusion line 6 shall thus enable to carry out pre-infusions, ensuring the optimal working of the machine also during this kind of treatments. Therefore, the particular arrangement of the pre- and post-infusion lines and of the dialysis lines enables—also in intensive therapy machines where all the various fluids are contained in small bags—to carry out all the necessary therapies/treatments, thus eliminating the operational limits present in known machines. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to an extracorporeal blood treatment machine and to an integrated treatment module that can be used on said machine. The object of the invention can be used for instance in intensive therapy machines which can carry out a plurality of different blood treatments. Extracorporeal treatments generally consists in taking blood from the patient, in treating said blood when it is outside the patient's body and then in re-circulating the blood thus treated. The treatment typically consists in removing from the blood unwanted and/or dangerous substances, as well as excess liquid in patients who cannot autonomously carry out said operations, such as for instances patients suffering from temporary or permanent kidney problems. For instance, it may be necessary to add or remove substances from blood, to keep a correct acid/base ratio or also to remove fluid excess from the body. The extracorporeal treatment is generally obtained by removing blood from the patient, by letting the blood flow within a filtration unit where a semipermeable membrane ensures the exchange of suitable substances, molecules and fluids. Generally though not necessarily, said exchange is carried out by letting a given biological fluid ensuring the aforesaid exchanges pass in counter-current and within a secondary chamber of the filtration unit. It should be noted that currently used machines can enable different types of blood treatment. In the ultrafiltration treatment the substances and fluids to be eliminated are removed by convection from the blood, pass through the semipermeable membrane and are led towards the aforesaid secondary chamber. In hemofiltration treatments part of the molecules, substances and fluids present in the blood pass through the membrane by convection as in the ultrafiltration treatment, although further necessary elements are added to the blood; typically a suitable fluid is infused directly into the blood before or after the latter passes through the filtration unit and anyhow before it is carried back into the patient. In haemodialysis treatments a fluid containing material to be transferred into the blood is introduced into the secondary chamber of the filtration unit. The unwanted material flows through the semipermeable membrane from the blood into the secondary fluid and the desired substances/molecules from the secondary fluid can pass through the membrane as far as the blood. In hemodiafiltration treatments the blood and the secondary fluid exchange their respective substances/molecules as in haemodialysis and, in addition, a fluid is infused into the blood as in haemofiltration treatments. Obviously, in order to carry out each of said extracorporeal blood treatments, the blood has to be removed from a patient's vein or artery, suitably circulated in the machine and then re-introduced into the patient. As is also known, blood treatment machines for intensive therapy have to be ready as fast as possible for an immediate use for any possible emergency. Obviously, to this purpose the machine must not require either preliminary sanitizing operations or long pre-assembling operations of the various components for the various therapies. As is known, intensive therapy machines are present on the market and are currently used, in which a blood circuit comprises a line for taking blood from the patient, which carries said blood to a filtration cartridge, and an outlet line from the filtration cartridge, which carries the treated blood back into the patient's body. The machine is then equipped with a circuit for the passage of dialysis fluid; also said circuit has an intake line leading into the filtration unit, which is supplied by a sterile bag containing the dialysis liquid, and has also an outlet line enabling the passage of a fluid which has received by convection/diffusion the dangerous substances and molecules from the blood towards a collection bag for their subsequent removal. Said machine is further equipped with an infusion line allowing with suitable doses—to transfer directly into the blood upstream from the filtration unit the content of another liquid bag, thus adding the necessary products into the blood. A known intensive therapy machine is further equipped with a suitable syringe containing for instance heparin as blood anticoagulant, the latter being added to the blood taken from the patient so as to avoid the creation of dangerous clots within the circuit. The structure and circuitry mentioned above are generally defined by a single integrated module attached to the machine body. It is evident that in order to enable the immediate use of the machine, the fluid bags referred to above have to be present and already sterile, so as to be directly and easily connected to their respective tubes, the latter also being sterile and disposable. The machine is further equipped with a suitable control unit managing the flow of fluids by means of suitable peristaltic pumps and respective sensors associated to the circuit. It is evident that by suitably setting the control unit said machine can selectively carry out one or more of the extracorporeal blood treatments described above (i.e. ultrafiltration, haemofiltration, haemodialysis and haemodiafiltration). The machine described above, though being today quite a vanguard device for extracorporeal blood treatments in intensive therapies, has proved to be susceptible of several improvements. In particular, a first intrinsic drawback in intensive therapy machines is related to the limited availability of fluids for operations involving the exchange of substances by convection/diffusion within the filter and for pre- or post-infusions into the blood line. Said limitation is obviously related to the necessary use of prepackaged sterile fluid bags typically containing 6 kg of dialysis liquid. It is evident that the pre-established fluid amount to be used imposes some limitations, in particular in the case of therapies with large exchange of fluids, which would sometimes be extremely suitable in emergency cases. On the other hand, it is not possible to use larger fluid amounts in intensive therapies since suitably treated water taken from the water network cannot be used as exchange fluid in short times; indeed, this would involve long operations for installing the devices for in-line preparation of sterile liquids; moreover, it is not possible to use bags with higher amounts of liquids due to the obvious problems involving transport and management of said containers by the personnel. Another problem of known intensive therapy machines consists in achieving an optimal management of the administration of anticoagulant substances which are necessary for a good working of the machine. In particular, today known intensive therapy machines cannot manage effectively the use of regional anticoagulation methods, such as for instance citrate-based methods, since the use of said techniques requires the administration of further solutions recovering the blood ion balance before carrying the treated blood back into the patient's body. | <SOH> SUMMARY OF THE INVENTION <EOH>Under these circumstances the present invention aims at solving basically all the drawbacks referred to above. A first technical aim of the invention is to provide physicians with the possibility to manage therapies with large exchange of fluids using an intensive therapy machine where, in any case, fluids are housed in small-size containers. A further aim of the present invention is to be able to manage intensive therapies by using regional anticoagulation techniques, i.e. acting on the blood only in the extracorporeal circuit, without having to limit pre-infusion upstream from the filtration unit. Moreover, an aim of the present invention is to enable the substantial separation of the use of regional anticoagulation techniques from the infusion of fluids for carrying out the necessary therapeutic exchange (by convection or diffusion). Finally, an auxiliary aim of the present invention is to provide an machine ensuring quite simple and reliable loading and installing operations, further enabling the complete control of the therapy cycles that are carried out. These and other aims, which shall be evident in the course of the present description, are basically achieved by an extracorporeal blood treatment machine as described in the appended claims. Further characteristics and advantages will be clearer from the detailed description of a preferred though not exclusive embodiment of an extracorporeal blood treatment machine according to the present invention. | 20040205 | 20080101 | 20050120 | 63230.0 | 2 | KIM, SUN U | EXTRACORPOREAL BLOOD TREATMENT MACHINE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,772,265 | ACCEPTED | Homogenization valve | A homogenization valve comprises an outer case, a homogenization mechanism contained in the outer case and having at least one homogenization device. The homogenization device comprises a high pressure chamber, in communication with a chamber for feeding the high pressure fluid to be homogenized, a low pressure chamber in communication with a channel for discharging the low pressure homogenized fluid. The high pressure chamber is connected to the low pressure chamber by means of a fluid blow-by port. The valve comprises at least two distinct homogenization devices connected in parallel with a same feeding channel and with a same discharge channel. | 1. A homogenization valve having: an outer case; a homogenization mechanism contained in the outer case and having at least one homogenization device; said at least one homogenization device defining a high pressure chamber in communication with a channel for feeding a fluid under high pressure to be homogenized, a low pressure chamber in communication with a channel for discharging the homogenized fluid under low pressure; said high pressure chamber being in communication with said low pressure chamber through a port for the blow-by of said fluid; said valve wherein comprises at least two distinct homogenization devices connected with a same feeding channel and with a same discharge channel. 2. A valve as claimed in claim 1, wherein said homogenization devices have cylindrical shape and are circumferentially positioned about a central axis, distanced from each other by 360°/n where n is the number of homogenization devices. 3. A valve as claimed in claim 1, wherein each homogenization device has: a movable assembly housed in a cavity of the outer case and having a lower piston defining with the inner surface of a compartment the high pressure chamber and an upper piston defining the low pressure chamber with the inner surface of an additional compartment; said chambers having the shape of cylinders with annular cross section; a ring or impact head, radially projecting from the lateral surface of said movable assembly and at least partially superposed to a projection of a passage head, defines a blow-by port together with said projection. 4. A valve as claimed in claim 3, wherein said movable assembly is capable of axially sliding in both direction within said cavity, constituted by various elements with cylindrical cavity superposed according to a longitudinal axis, by actuating means, to control the amplitude of the blow-by port. 5. A valve as claimed in claim 4, wherein said actuating means has a hydraulic or pneumatic cylinder, connected to a plate that is operatively active on the movable assembly of all the devices. 6. A valve as claimed in claim 1, wherein the homogenization devices are connected to the feeding channel by means of radial union fittings facing said feeding channel in positions that are circumferentially distanced from each other by 360°/n where n is the number of homogenization devices. 7. A valve as claimed in claim 1, wherein the homogenization devices are connected to the discharge channel by means of axial union fitting facing said discharge channel in positions that are circumferentially distanced from each other by 360°/n where n is the number of the homogenization devices. 8. A valve as claimed in claim 1, wherein said feeding channel is centrally positioned. 9. A valve as claimed in claim 1, having a movable assembly constituted by an upper piston and a lower piston, in turn constituted by a set of elements. 10. A valve as claimed in claim 9 wherein the set of elements in the case of the lower piston comprises: an appropriately contoured cylindrical body provided with a compartment for housing a bushing or bearing made of frictionless material and locked in turn by an element mated with the cylindrical body and the bushing and fastened to the cylindrical body by means of a connecting element; and in the case of the upper piston it comprises an appropriately contoured cylindrical body provided with a compartment for housing a bushing or bearing made of frictionless material and locked in turn by an element mated with the cylindrical body and the bushing and fastened to the cylindrical body by means of a connecting element. 11. A valve as claimed in claim 9 wherein elements for guiding the movable assembly are integrated therein to prevent the contact between metallic surface during its motion. | BACKGROUND OF THE INVENTION The present invention relates to the field of homogenizing apparatuses. The homogenization process has the function of reducing the dimensions of the drops of an emulsion, or of the particles of a suspension, and to make them as homogeneous and identical to each other as possible. The homogenization process generally comprises the passage (blow-by) of the fluid to be homogenized, under appropriate pressure, through a nozzle or a very narrow passage, to cause impacts and subdivisions of the particles; preferably, the flow of particles exiting at high speed from said passage is made to impact against an obstacle located at a short distance from the passage, which further contributes to reduce the dimensions of the particles and improve homogenization. In this field the Applicant has already obtained the Italian patent IT 1.282.765, and filed the corresponding European patent application, publication EP 0.810.025, with the disclosure of an improved homogenization valve. Essentially, the aforesaid valve comprises two consecutive coaxial annular chambers, separated by a nozzle with radial profile whose height is governed by a pressure means acting in the axial direction against a piston sliding axially within said chambers whereof it defines the radially interior wall: this valve allows to use high pressures for feeding the fluid to be homogenized, to over 1000 bar, minimizing the force needed to maintain the dimensions of the nozzle, whilst providing a product with high quality characteristics. The Applicant has now set the goal of increasing the flow rate of the valve whilst maintaining all other conditions equal, i.e. without increasing the size of the valve and the applied pressure, maintaining constant or improving the efficiency of the homogenization, i.e. the quality of the final product. The problem is not an easy one to solve because it is not possible simply to increase the size of the nozzles, nor is it sufficient to multiply their number, since both these measures either fail to achieve the desired result or compromise the quality characteristics of the finished product or unacceptably raise the cost of the valve. In particular, in the case of an increase in the number of nozzles, the degree of homogenization and the consistency of the result are compromised because it is impossible to maintain the same fluid feeding pressure: this inequality of pressure also causes, over time, a different degree of wear of the different nozzles, with variation in their section and in the fluid-dynamic characteristics of the traversing flow. The consequences are the impossibility of keeping the phenomenon under control and an unacceptable degradation of the quality characteristics of the homogenized. The Applicant has now defined a plurality of construction elements of the valve and identified a series of critical relationships between said construction elements which allow to obtain the sought result. SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide a homogenization valve as better specified in the appended claim 1 and in the additional claims dependent therefrom. In particular, the valve comprises at least two distinct homogenization devices arranged in parallel, connected with a same feeding channel and with a same discharge channel. BRIEF DESCRIPTION OF THE DRAWINGS Further features and advantages of the invention shall become more readily apparent from the detailed description that follows of a preferred and non limiting embodiment of the invention, with reference to the accompanying drawings, provided purely by way of non limiting example, in which: FIG. 1 is a top schematic plan view of a homogenization valve according to the present invention, in the case of the three homogenization devices; FIG. 2 is a schematic axial section on the plane A-A of FIG. 1 of a homogenization valve according to the invention; FIG. 3 is a schematic axial section on the plane B-B of FIG. 1 of the homogenization valve of FIG. 2; FIG. 4 is an exploded view of the valve. FIGS. 5, 6 and 7 show an embodiment variant of the valve. DESCRIPTION OF THE PREFERRED EMBODIMENTS The reference number 1 designates a homogenization valve in accordance with the present invention. FIG. 1 shows the new valve 1 of the invention seen from the top, in plan view. In the preferred embodiment described herein, and without any limitation whatsoever deriving therefrom, the valve 1 comprises an outer case 2, having substantially prism shape, with noticeably quadrangular plan shape, with sides or dimensions of about 20-25 cm of length, in which is contained a homogenization mechanism 3 which will be described in detail below. The lines A-A and B-B represent the trace of the section planes of FIGS. 2 and 3. FIGS. 2 and 3 show the valve 1 sectioned respectively according to the planes A-A and B-B of FIG. 1: the case 2 has a height of about 40 cm. The case 2 comprises a lower distributor valve-body 4 and an upper valve-body 5 for each of the homogenization devices, a manifold body 6 and a spacer head 7 sequentially superposed in the axial direction. In the present description, the term “axial” means the direction of longitudinal development of the valve 1, whose trace is designated by the reference letter “O” in the plane of the FIG. 1; “O” represents the intersection between said plane and the central longitudinal axis O-O. The “axially internal” position is the one oriented downwards in FIGS. 2 and 3, the “axially external” position is the one oriented upwards in the aforesaid figures. The “radial” position is the one perpendicular to the axial direction, the “radially internal” position is the one oriented towards the interior of the case 2, the “radially external” position is the one oriented towards the exterior of the case 2. Inside said valve-bodies 4, 5 and said manifold body 6 are obtained in the illustrated case three homogenization devices 8a, 8b, 8c circumferentially positioned around said axis O-O, distanced by about 120° from each other and constituting the homogenization mechanism 3. There may also be only two or more than three homogenization devices. Said devices 8a, 8b, 8c have preferably cylindrical shape, with axis X-X parallel to the axis O-O. The bulk of each of the devices 8a, 8b, 8c is represented by a circumference C1 with radius “r” “Xa”, “Xb” and “Xc” represent the intersections between the plane of FIG. 1 and the longitudinal axis X-X passing through the center of the circumference C1 of each of the devices 8a, 8b, 8c. The description that follows refers in particular to this preferred embodiment. With reference to each of said devices 8a, 8b, 8c, the lower valve body 4 comprises a first compartment 9 axially superposed to a second coaxial compartment with smaller diameter designated by the reference number 10: in fact, the reference 10 of FIG. 2 more specifically designates the inner surface of the compartment within which slides a lower piston 26. In axially exterior position to the compartment 9 the lower valve body 4 has a third coaxial compartment 11, whose diameter is greater than that of the first compartment, housing a passage ring or head 12 which has on the axial external, in radially interior position, a projection 13 with reduced radial dimension, preferably tapered in the axial direction. The radially inner surface of said ring 12 is aligned with the surface of the first compartment 9 and together they delimit the radially outer wall of said compartment 9. The axis common to the first, second and third compartment is the aforementioned axis X-X. The first compartment 9 is in communication, through a radial union fitting 14, of preferably circular cross section, with a channel 15 for feeding the fluid to be homogenized, preferably coaxial with the axis O-O. Preferably, the feeding channel 15 has circular cross section. Preferably, the area of the cross section of the union fitting 14 is at least equal to 1/n of the area of the channel 15, where n is the number of homogenization devices present. The Applicant has found that if a single feeding channel 15 feeds two or more homogenization devices, preferably by means of union fittings 14 which respect the enunciated critical value, the consistency of the fluid feeding pressure and the equality of said pressure in each homogenization device 8a, 8b, 8c even in the case of small and inevitable changes in the feeding flow rate to the valve 1. It should be remembered that the inflow pressure of the fluid into the valve, generated by the partial closure of the elements of the valve itself, can vary and is selected according to fluid type and according to specific homogenization needs for each product. Preferably, the aforesaid union fittings 14 open on said feeding channel 15 in positions that are circumferentially distanced from each other by 120°, or generically by an angle 360°/n, where n is the number of homogenization devices present. Each of the upper valve bodies 5 comprises a fourth compartment 16 whose diameter is larger than that of the first compartment, which, when the upper valve body 5 is mounted on the lower valve body 4, is also aligned according to the axis X-X. The fourth compartment 16 can widen inferiorly to house an annular crown or impact ring 17, positioned on the axially outer surface of the ring 12. Said impact ring 17 has a slightly smaller radially inner diameter than that of the fourth compartment, but slightly larger than that of a ring 34. It also has a radially outer diameter that is slightly larger than that of the fourth compartment in such a way as to allow the univocal positioning of the ring 12. The upper valve bodies 5, present in a number n as a function of the number n of the individual homogenization devices installed in parallel, can also be provided as a single element such as to have the same geometric and functional characteristics as the inner cavities of the individual valve bodies 5. The fourth compartment 16 narrows in axially outer position, forming a fifth compartment 18 of any diameter, but preferably equal to that of the second compartment, which allows to house a guidance bushing dedicated to guiding without friction the displacement, axial and along the axis X-X of the movable assembly 31 constituted by lower piston 26, impact ring or head 34 and upper piston 23, mutually connected by means of a threaded element 35. The movable assembly 31 can also be constructed in such as way that both the upper piston 23 and the lower piston 26 are not made in a single piece, but are in turn constituted by a set of elements in order to eliminate any contact between the metallic parts of the pistons and respectively the upper valve body 5 and the lower valve body 4. The lower piston 26 can be constituted by an appropriately contoured cylindrical body X1 provided with a compartment for housing a bushing or bearing X2 made of frictionless material (e.g. a plastic polymer), and in turn blocked by an element X3 mated with X1 and X2 and fastened to X1 by means of a connecting element, such as screws X4. The same holds true for the upper piston 23 which can be constituted by an appropriately contoured cylindrical body Y1 provided with a compartment for housing a bushing or bearing Y2 made of frictionless material (e.g. a plastic polymer), and in turn locked by an element Y3 mated with Y1 and Y2 and fastened to Y1 by means of a connecting element such as screws Y4. In this way the upper valve body 5 does not require the presence of an additional compartment 18 for housing a guiding bushing, since said bushing, identified as Y2, is already integrated in the movable assembly 31. X2 and Y2, which constitute guiding elements of the movable assembly 31, are integrated therein to prevent contact during its movement between unsuitable metallic surfaces to allow their movement within the lower valve body 4 and the upper valve body 5 without problems with seizing or noisiness. The fourth compartment 16 or discharge chamber is in communication, through an axial union fitting 19, with a channel 20 for discharging the homogenized fluid, positioned with radial profile within the manifold body 6. Preferably, the discharge channel 20 has circular cross section. The Applicant has found that if a single discharge channel 20 connects the homogenization devices, the equality of the pressure differential between the first compartment 9 and the fourth compartment 16 in each homogenization device is assured, along with the uniformity of the degree of homogenization of the finished product. Preferably, said axial union fittings 19 open onto said discharge channel 20 in positions that are circumferentially distanced from each other by 360°/n. In the manifold body 6 are also obtained sixth compartments 21, one for each homogenization device 8a, 8b, 8c, with axis X-X and greater diameter than the fifth compartment to allow the axial movement of the movable assembly 31 without contact with the manifold body 6. When the manifold body 6 is mounted on the upper valve body 5, it is also aligned according to the axes O-O and X-X. The spacer head 7 superiorly closes the case of the valve 1 and constitutes the bearing surface of the pneumatic actuator used to generate the axial thrust force able to produce the homogenization pressure within the valve. Each group of first 9, second 10, third 11, fourth 16, fifth 18 and sixth 21 compartments, axially aligned according to an axis X-X defines a cavity 22 within which is housed the movable assembly 31, movable in both directions and inferiorly defining an axial cavity 27 within which is housed a contrasting spring 28, working by compression, preferably inserted on a pivot 29 axially projecting from the base 30 of the lower valve body 4. An impact ring or head 34 is applied on an axial protuberance 32 of the upper piston, and it has slightly smaller diameter than the radially inner diameter of the crown 17, which in turn is smaller than the passage head 12. A fastening means 35, such as a screw, mutually assembles in integral fashion the lower piston 26, upper piston 23, and ring 34. The radially outer surface of the lower piston 26 defines the radially inner wall of the first compartment 9. The part of the axially inner surface of the ring 34 that projects from the lower piston 26 defines the ceiling of the first compartment 9. The radially outer surfaces of the upper piston 23 and of the impact ring or head 34 define the radially inner wall of the fourth compartment 16. The coupling between lower valve body 4 and lower piston 26 defines a high pressure chamber 36 of the homogenization device 8a, 8b, 8c, whilst the coupling between upper valve body 5 and the upper piston 23 defines a low pressure chamber 37 of the aforesaid device 8a, 8b, 8c. In other words, the lower piston 26 defines with the inner cylindrical surface of the compartment 9 the high pressure chamber 36 and the upper piston 23 defines with the inner surface of the compartment 16 the low pressure chamber 37. The chambers 36, 37 have the shape of cylinders with annular cross section. An upper O-ring type gasket 45 and a corresponding similar lower gasket 46 contain the area for the passage of the fluid. The high pressure chamber 36 and the low pressure chamber 37 are separated by an annular gap 38 (blow-by port) defined between the surfaces axially facing each other of the projection 13 and of the ring 34, through which the fluid flows from the first compartment 9 to the fourth compartment 16. C1 and X represents the intersection traces of the gap 38 and of the axis of the devices with the plane of FIG. 1. Preferably, the axial development of the impact ring 17 is slightly greater than the height of the gap 38, in order to assure a sufficient amplitude of the surface radially facing said gap 38 against which the fluid flowing out of the gap 38 impacts at high speed. The axial dimension of said port 38 (gap height) is governed by the axial displacement of the piston 23 and more specifically of the axially movable ring (impact head) 34, relative to the fixed passage ring or head 12. It can be noted that the movable assembly 31 is guided in the fifth compartment 18 and in the second compartment 10, i.e. in mutually distanced positions along the axis X-X: in this way, a rigorously axial displacement is assured, free from vibrations and radial thrusts which can compromise the linearity of the motion, and any jams thereof. An axially outer surface 39 of the upper piston 23 abuts against the axially inner surface 40 of a plate 41, able to slide within a cavity 42 of the spacer head 7, secured to any known device, generally a hydraulic or pneumatic cylinder 43, preferably fastened directly by means of screws to the manifold body 6 by interposition of the spacer head 7, to apply an axial thrust to the plate 41. According to the invention, the plate 41 is operatively active simultaneously on the movable assemblies 31 of all the devices 8a, 8b, 8c. The plate 41 and the hydraulic or pneumatic cylinder 43 are means 44 for actuating the movable assemblies 31 that control the amplitude of the blow-by port. The Applicant has intuited that only the centralized control of the force applied by the plate 41, antagonistic with the elastic reaction exerted by the contrast spring 28 on each movable assembly 31, allows to maintain the height of the gap 38 constant in all devices 8a, 8b, 8c. The aforesaid height is the one resulting from the condition of equilibrium between the thrust of the force applied to the axially outer end of the movable assembly 31 and the elastic reaction exerted by the contrast spring 28 on the axially inner end of the aforesaid movable assembly 31. The invention achieves many important advantages. Note that the flow rate of the vale of the invention is given by the sum of the flow rate of the individual devices and the flow rate of each devices is determined by the cross section of the passage gap, multiplied times the velocity of the flow, in turn determined by the difference in pressure between the two chambers, respectively at high and low pressure. The cross section of the passage gap is given by the product of the linear development of the gap times its height, so that, all other conditions being equal, it depends only on its linear development. Note that the linear development of the gap of each device corresponds to the perimeter of the cylindrical surface with diameter D1, i.e. to the circumference C1. The circumference C1 is always greater than one nth the effective circumference of the maximum known valve dimension (for instance with a diameter of about 137 mm, but which can also have additional dimensional variants), since the diameter of C1 is for example equal to about 83 mm, but it may also have further dimensional variants according to the dimensioning requirements of the valve of the present invention for n equal to or greater than 2. In conclusion, the flow rate of the valve of the invention can greatly increase the flow rate of the equivalent known valve for the same axial fluid passage distance between passage head 12 and impact head 34; in the case of n=3, the increase of the passage surface is about 80%. Moreover, for a given flow rate, since the sum of the different C1 values is large relative to the C of the traditional valve, the height of the gap can be reduced further, thereby improving homogenization efficiency. The valve is very compact and its limited greater weight as well as its low greater cost, because of the complexity due to the presence of multiple homogenization devices instead of the single previous mechanism, are amply offset by the achieved advantages. In the present description, all possible structural and cinematic alternatives to the embodiments of the invention specifically described herein have not been illustrated. However, they are understood to be equally included within the scope of protection of the present invention, since such alternative embodiments are in themselves easily identified by the description provided herein of the relationship that links each embodiment with the result the invention sets out to achieve, because the intention is to stress the modularity of the adopted solution which in principle may comprise a number n of homogenization devices operating in parallel and under the same conditions of differential pressure each on an nth portion of the total portion that traverses the device. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to the field of homogenizing apparatuses. The homogenization process has the function of reducing the dimensions of the drops of an emulsion, or of the particles of a suspension, and to make them as homogeneous and identical to each other as possible. The homogenization process generally comprises the passage (blow-by) of the fluid to be homogenized, under appropriate pressure, through a nozzle or a very narrow passage, to cause impacts and subdivisions of the particles; preferably, the flow of particles exiting at high speed from said passage is made to impact against an obstacle located at a short distance from the passage, which further contributes to reduce the dimensions of the particles and improve homogenization. In this field the Applicant has already obtained the Italian patent IT 1.282.765, and filed the corresponding European patent application, publication EP 0.810.025, with the disclosure of an improved homogenization valve. Essentially, the aforesaid valve comprises two consecutive coaxial annular chambers, separated by a nozzle with radial profile whose height is governed by a pressure means acting in the axial direction against a piston sliding axially within said chambers whereof it defines the radially interior wall: this valve allows to use high pressures for feeding the fluid to be homogenized, to over 1000 bar, minimizing the force needed to maintain the dimensions of the nozzle, whilst providing a product with high quality characteristics. The Applicant has now set the goal of increasing the flow rate of the valve whilst maintaining all other conditions equal, i.e. without increasing the size of the valve and the applied pressure, maintaining constant or improving the efficiency of the homogenization, i.e. the quality of the final product. The problem is not an easy one to solve because it is not possible simply to increase the size of the nozzles, nor is it sufficient to multiply their number, since both these measures either fail to achieve the desired result or compromise the quality characteristics of the finished product or unacceptably raise the cost of the valve. In particular, in the case of an increase in the number of nozzles, the degree of homogenization and the consistency of the result are compromised because it is impossible to maintain the same fluid feeding pressure: this inequality of pressure also causes, over time, a different degree of wear of the different nozzles, with variation in their section and in the fluid-dynamic characteristics of the traversing flow. The consequences are the impossibility of keeping the phenomenon under control and an unacceptable degradation of the quality characteristics of the homogenized. The Applicant has now defined a plurality of construction elements of the valve and identified a series of critical relationships between said construction elements which allow to obtain the sought result. | <SOH> SUMMARY OF THE INVENTION <EOH>Therefore, the object of the present invention is to provide a homogenization valve as better specified in the appended claim 1 and in the additional claims dependent therefrom. In particular, the valve comprises at least two distinct homogenization devices arranged in parallel, connected with a same feeding channel and with a same discharge channel. | 20040206 | 20061205 | 20050421 | 96658.0 | 0 | SORKIN, DAVID L | HOMOGENIZATION VALVE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,772,528 | ACCEPTED | Analog preamplifier measurement for a microphone array | An analog preamplifier measurement system for a microphone array builds on conventional microphone arrays by providing an integral “self-calibration system.” This self-calibration system automatically injects an excitation pulse of a known magnitude and phase to all preamplifier inputs within the microphone array. The resulting analog waveform from each preamplifier output is then measured. A frequency analysis, such as, for example, a Fourier or Fast Fourier Transform (FFT), or other conventional frequency analysis, of each of the resulting waveforms is then performed. The results of this frequency analysis are then used to automatically compute frequency-domain compensation gains (e.g., magnitude and phase gains) for each preamplifier for matching or balancing the responses of all of the preamplifiers with each other. | 1. A system for automatically matching preamplifiers in a microphone array, comprising: injecting at least one excitation pulse into each preamplifier in the microphone array; measuring each preamplifier output response to each excitation pulse; performing a frequency-domain analysis of the measured preamplifier output response to each excitation pulse; and computing frequency-domain compensation gains from the results of the frequency-domain analysis for matching the output of each preamplifier. 2. The system of claim 1 wherein two or more excitation pulses are injected into each preamplifier in the microphone array, and wherein the measured preamplifier output response for each preamplifier is the average response to each excitation pulse. 3. The system of claim 1 wherein the microphone array further comprises a computer interface for connecting the array to an external computing device. 4. The system of claim 3 wherein the at least one excitation pulse is automatically generated by the microphone array in response to a pulse generation command from the external computing deice via the computer interface. 5. The system of claim 3 wherein the microphone array further comprises an integral memory for maintaining a set of parameters defining operational characteristics of the microphone array. 6. The system of claim 5 wherein the set of parameters defining operational characteristics of the microphone array is automatically reported to the external computing device via the computer interface. 7. The system of claim 6 wherein the set of parameters defining operational characteristics of the microphone array includes information defining the computed frequency-domain compensation gains for each preamplifier in the array. 8. The system of claim 3 wherein the computer interface for connecting the array to the external computing device is any of a wired and a wireless computer interface. 9. A method for automatically matching preamplifier frequency-domain responses in a microphone array, comprising using a computing device to: generate at least one analog excitation pulse of a predetermined phase, magnitude and duration and provide the at least one generated analog excitation pulse to an input of each preamplifier in a microphone array; digitize an output resulting from each excitation pulse for each preamplifier in the microphone array; perform a frequency-domain analysis of the digitized output for each preamplifier in the microphone array; and compute frequency-domain compensation gains from the results of the frequency-domain analysis for matching the output of each preamplifier in the microphone array with each other. 10. The method of claim 1 wherein for each analog excitation pulse provided to the input of each preamplifier in a microphone array, the resulting digitized outputs are averaged, and wherein the averaged digitized output for each preamplifier is used to perform the frequency-domain analysis and to compute the frequency-domain compensation gains from the results of the frequency-domain analysis. 11. The method of claim 9 wherein the computed frequency-domain compensation gains are used to automatically configure audio processing software operating within an external computing device to reflect a current configuration of the microphone array, said microphone array being coupled to the external computing device via any of a wired and a wireless computer interface. 12. The method of claim 9 wherein the computed frequency-domain compensation gains are stored locally within the microphone array within a microphone array memory. 13. The method of claim 12 wherein the microphone array memory further includes information defining microphone types and geometry for each microphone in the microphone array, and a microphone array working volume for each microphone in the microphone array. 14. The method of claim 12 wherein the microphone array memory is a programmable memory, and wherein the information stored within the programmable memory in an addressable lookup table. 15. A system for automatically calibrating preamplifiers in a microphone array to provide matched preamplifier outputs, comprising: a microphone array including at least one microphone, each microphone further including at least one preamplifier; said microphone array further including a switchable pulse generation circuit for generating excitation pulses of a predetermined duration, magnitude and phase; remotely initiating generation of at least one excitation pulse in the switchable pulse generation circuit from a remote computing device coupled to the microphone array via a computer interface; automatically injecting each excitation pulses into each preamplifier; measuring an output resulting from each injected excitation pulse for each preamplifier; providing the measured output for each preamplifier to the remote computing device via the computer interface; on the remote computing device, performing a frequency-domain analysis of the measured output for each preamplifier; and computing frequency-domain compensation gains from the results of the frequency-domain analysis for matching the output of each preamplifier in the microphone array with each other. 16. The system of claim 15 wherein the measured output for each preamplifier is averaged with each other measured output for each individual preamplifier, and wherein the averaged output for each preamplifier is provided as the measured output for each preamplifier to the remote computing device via the computer interface. 17. The system of claim 15 wherein the microphone array further includes at least one addressable memory for storing operational parameters of the microphone array; and wherein the microphone array automatically reads the parametric information from the addressable memory and reports the parametric information to the external computing device via a computer interface, said external computing device being remotely coupled to the microphone array via the computer interface. 18. The system of claim 15 wherein the microphone array further includes a set of at least one speaker for reproducing one or more audio signals. 19. The system of claim 15 wherein the computer interface is any of a wired and a wireless computer interface. 20. The system of claim 22 further comprising automatically configuring audio processing software operating within the external computing device to reflect the computed frequency-domain compensation gains for each preamplifier in the microphone array when processing audio signals being provided to the external computing device from the microphone array via the computer interface. | BACKGROUND 1. Technical Field The invention is related to a microphone array preamplifier measurement system, and in particular, to a system and method for automatically determining gain variations between one or more analog microphone/preamplifier channels in a microphone array and a system and method for automatically compensating for such gain variations to provide for improved processing of audio signals captured via the microphone array. 2. Related Art Conventional microphone array type devices are well known to those skilled in the art. In general, microphone arrays typically include an arrangement of microphones in some predetermined layout. These microphones are generally used to capture sounds from various directions and originating from different points of the space. Once captured, onboard sound processing software and hardware then provides sound processing capabilities, such as, for example, sound source localization, beam forming, acoustic echo cancellation, noise suppression, etc. For example, one common use for such arrays involving audio conferencing systems is to determine the direction of a dominant speaker in a room having both active speech and other noise, and then to process the input from the various microphones in the array accordingly. In particular, given the input from each of the microphones in the array, conventional beam forming and sound source localization computations are used to localize the position and direction of the person currently speaking. With this information, it is then possible to filter out all sounds not coming from the direction of the speaker, thereby improving the overall quality of the captured sound with respect to the person speaking. In general, such microphone arrays typically include one or more sets of matched microphone/preamplifier combinations. In other words, the electronic components, i.e., microphones, preamplifier circuits, etc., within such microphone arrays are carefully chosen so that that the frequency responses of the various microphone/preamplifier combinations within the microphone array are as close as possible to one another for any particular audio input. Matching the gains and frequency responses among the preamplifier circuits is important because variations across channels degrade the performance of the aforementioned beam forming and sound source localization algorithms. Unfortunately, choosing electronic components for matching the frequency response of the various microphone/preamplifier combinations within a microphone array is typically rather expensive, thereby increasing the cost of such microphone arrays. For example, choosing electronic components with matching responses is typically accomplished either through the careful testing of a large batch of individual electronic components to identify those with matching properties, or through the use of relatively expensive high-precision electronic components (capacitors, resistors, op amps, etc.) that are guaranteed to have particular electrical properties within some small tolerance. Both cases tend to significantly increase the cost of matched sets of microphone/preamplifier combinations for a microphone array. Further, in the case where inexpensive electronic components of some nominal tolerance are used there will likely be a relatively wide variation in the frequency response of each microphone/preamplifier combination within the microphone array. As a result, in order to achieve optimal audio processing performance, the response of each individual microphone/preamplifier combination within the microphone array must be pre-determined, and any software designed to process audio signals captured by the microphone array must then be specifically tailored to the specific operational parameters of each microphone/preamplifier combination within that array. Consequently, each such microphone array typically requires customized software, thereby increasing both test time and cost to manufacture individual microphone arrays. Further, the operational parameters of individual electronic components in a microphone array tend to change, if even only slightly, over time, and relative to the local temperature of such electronic components. Therefore, software tailored to a particular microphone array configuration may still produce sub-optimal audio processing results where the parameters of the microphone array fail to precisely match the expected operational parameters coded into any associated audio processing software or hardware. Therefore, what is needed is a system and method for allowing a microphone array to avoid the use of expensive matched electronic components by allowing for the use of relatively less expensive non-matched electronic components. Further, rather than requiring software to be specifically pre-tailored to the particular operational parameters of each microphone/preamplifier combination within the array, the microphone array should instead be operable with software that automatically configures itself to the operational parameters of the microphone array. Consequently, such a system and method should automatically determine and compensate for variations in the gain and frequency response of each microphone/preamplifier combination within the array to allow for automatic configuration and optimization of audio processing software associated with the microphone array. SUMMARY As is well known to those skilled in the art, conventional microphone arrays typically include an arrangement of one or more microphones in some predetermined layout. In general, each microphone in these arrays typically includes an associated preamplifier for providing amplification or gain for analog audio signals captured by each microphone. Further, each of the input channels (i.e., each microphone/preamplifier combination) of such microphone arrays are typically matched so that that the sensitivity and frequency responses of those input channels are as close as possible to one another for any particular audio input. However, providing for matched components in a microphone array tends to increase both cost and test time when manufacturing such arrays. Therefore, in contrast to conventional microphone arrays, an analog preamplifier measurement system for a microphone array, as described herein, operates to solve the problems identified above by providing a modified microphone array with an integral “self-calibration system.” In general, this integral self-calibration system automatically determines frequency-domain responses of each preamplifier in the microphone array, and computes frequency-domain compensation gains, so that digital signal processing applications can use those compensation gains for matching the output of each preamplifier. As a result, there is no need to predetermine exact operational characteristics of each channel of the microphone array, or to use expensive matched electronic components. Further, as is well known to those skilled in the art, individual microphone operational characteristics, as well as the characteristics of most other electrical components, tend to change both over time and as a function of local temperature. Consequently, use of the integral self-calibration system provides current operational parameters of the microphones and associated preamplifiers within the microphone array which better reflect actual component parameters than factory measured values which are typically coded into conventional microphone arrays or audio processing software. In operation, the integral self-calibration system injects excitation pulses of a known magnitude and phase to all preamplifier inputs within the microphone array. Note that the duration of the pulse should be larger than the preamplifier step response so as to avoid or minimize any effects resulting from transient responses. The resulting analog waveform from each preamplifier output is then measured. A frequency analysis, such as, for example, a Fourier or Fast Fourier Transform (FFT), or other conventional frequency analysis, of each of the resulting waveforms is then performed. The results of this frequency analysis are then used to compute frequency-domain compensation gains for each preamplifier for matching or balancing the responses of all of the preamplifiers with each other. In one embodiment, the integral self-calibration system is included in a “self-descriptive microphone array,” as described in a copending patent application entitled “SELF-DESCRIPTIVE MICROPHONE ARRAY,” having a filing date of TBD, and assigned Serial Number TBD, the subject matter of which is incorporated herein by this reference. In this embodiment, the integral self-calibration system operates automatically either upon connection of the self-descriptive microphone array to the external computing device, upon regular or user-specified intervals, or upon command. In this embodiment the injection of pulses, readings of the preamplifier outputs, and computation of the frequency analysis, are all performed by driver software residing in the external computing device connected to the microphone array. Once computed, these frequency-domain compensation gains can then be applied to the output of each corresponding preamplifier when processing actual audio inputs of the microphones associated with each preamplifier. This serves to make the output from each of the preamplifiers consistent, given the same or similar input to any of the microphones in the array. Consequently, using these computed frequency-domain compensation gains, audio processing software such as, for example, software for performing sound source localization, beam forming, acoustic echo cancellation, noise suppression, etc., can easily compensate for phase response mismatches across all preamplifiers. Without this compensation, any phase response mismatches would reduce the performance of the audio processing software. Therefore, as a result of computing and providing these frequency-domain compensation gains for each preamplifier, there is no need to use expensive matched electrical components. Consequently, one advantage offered by the integral self-calibration system described herein is that microphone arrays using this integral self-calibration system may be inexpensively produced by using relatively inexpensive non-matched electrical components including, for example, transistors, capacitors, resistors, op amps, etc. As noted above, the integral self-calibration system operates by first injecting a single pulse of a known magnitude and phase to each preamplifier. Then, as described above, the output of each preamplifier is then measured and used to compute frequency-domain compensation gains for each preamplifier. However, in another embodiment, multiple pulses of a known magnitude and phase are instead injected to each preamplifier. Then, for each preamplifier, the output resulting from each of the injected pulses is averaged. The averaged output of each preamplifier is then used to compute frequency-domain compensation gains for each preamplifier, as described above for the case of the single injected pulse. In yet another embodiment, circuitry is included in the microphone array for automatically switching off the input from each microphone prior to inputting each the aforementioned pulse or pulses to each corresponding preamplifier. However, it has been observed that in the embodiment wherein multiple pulses are used along with an average of the preamplifier output, any noise resulting from allowing the microphones to remain active or live during pulse injection has a negligible effect on the computed frequency-domain compensation gains for each preamplifier, especially as the number of pulses increases. As noted above, in one embodiment, the integral self-calibration system is included in a self-descriptive microphone array which makes use of external computing power for performing computations. In this embodiment, the frequency analysis for computing the frequency-domain compensation gains for each preamplifier is performed by an external computing device, such as a PC-type computer, or other computing device, coupled to the microphone array. One advantage of this embodiment is that because the microphone array makes use of external processing power, there is no need to include relatively expensive onboard signal processing software or hardware capabilities within the array itself. Consequently, the self-descriptive microphone array is relatively inexpensive to manufacture in comparison to conventional microphone array devices that include onboard audio processing capabilities. Note that the connection (a “microphone array interface”) between the self-descriptive microphone array and the external computing device is accomplished using any of a variety of conventional wired or wireless computer interfaces, including, for example, serial, parallel, IEEE 1394, USB, IEEE 802.11, Bluetooth™, etc. In another embodiment, as described in the aforementioned copending patent application entitled “SELF-DESCRIPTIVE MICROPHONE ARRAY,” the microphone array further includes a “microphone array memory” that is integral to the microphone array. This microphone array memory includes any type of non-volatile memory, such as, for example a ROM, PROM, EPROM, EEPROM, or other conventional non-volatile memory type or device, which contains a microphone array device description. This device description includes parametric information, including the computed frequency-domain compensation gains for each preamplifier, which defines operational characteristics and configuration of the microphone array. In operation, the device description of the microphone array is automatically reported to the external computing device via the microphone array interface to the external computing device. In this embodiment, once the microphone array device description is provided to the external computing device, the external computing device then uses the device description to automatically configure audio processing software residing within the external computing device for processing one or more audio signals captured by the microphone array. Specifically, software applications residing within the external computing device, such as dynamic link libraries (DLLs) or other software drivers or programs, interpret physical parameters of the microphone array, including the frequency-domain compensation gains, that are provided by the microphone array device description. These software applications then communicate the physical parameter data of the microphone array to signal processing software residing within the external computing device. This allows the signal processing software to automatically adjust its operational parameters to the characteristics of the attached microphone array to perform automatically optimized audio processing computations. As noted above, preamplifiers are associated with each microphone in the microphone array. Further, to allow for multiple simultaneous channels of audio to be captured by the microphone array, one or analog-to-digital (A/D) converters are also associated with each microphone. Audio signals captured by the microphone array are then pre-amplified (i.e., gain) and converted to a digital signal via the A/D converters and provided, via the aforementioned wired or wireless computer interface, to the audio processing software residing within the external computing device for further processing, as desired. The maximum number of digital audio channels that can then be transmitted via the computer interface is then only limited by the maximum bandwidth of that computer interface in combination with the digital sampling rate of each channel of the microphone array. In another embodiment, in addition to including one or more microphones, the microphone array also includes one or more loudspeakers for reproducing one or more audio signals. For example, many microphone arrays, such as those arrays used for audio conferencing, frequently include both microphones and speakers. The microphones capture sound, and the speakers play back sound. Generally, conventional audio conferencing-type microphone arrays also include relatively expensive onboard acoustic echo cancellation capabilities so that local audio signals are not endlessly echoed during an audio conference. However, in the context of the aforementioned self-descriptive microphone array, audio processing, such as acoustic echo cancellation, is performed via the audio processing software residing within the external computing device. In this embodiment, audio to be played back via the self-descriptive microphone array is then simply transmitted from the external computing device to the array via the aforementioned wired or wireless computer interface. In this embodiment, as with the parametric information defining the microphones and preamplifiers within the microphone array, parametric information defining the speakers within the microphone array is also stored within the microphone array memory. Configuration of the microphone array is then reported, as noted above, to allow for automatic configuration of the audio processing software residing within the external computing device to which the microphone array is connected. In view of the above summary, it is clear that the integral self-calibration system for the microphone array provides a unique system and method for automatically determining frequency-domain compensation gains for each audio input channel within the array. In addition to the just described benefits, other advantages of the self-calibration system for the microphone array will become apparent from the detailed description which follows hereinafter when taken in conjunction with the accompanying drawing figures. DESCRIPTION OF THE DRAWINGS The specific features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: FIG. 1 is a general system diagram depicting a general-purpose computing device constituting an exemplary system for interfacing with a microphone array. FIG. 2 illustrates an exemplary system diagram showing exemplary hardware and software modules for implementing a microphone array. FIG. 3 illustrates an exemplary architectural layout of a hardware system embodying a microphone array. FIG. 4 provides an exemplary operational flow diagram which illustrates the operation of a microphone array having an integral self-calibration system. FIG. 5 provides an exemplary operational flow diagram which illustrates the operation of the integral self-calibration system of FIG. 4. FIG. 6 provides an exemplary circuit diagram for the preamplifiers, highpass filter modules and analog-to-digital converters that comprise the analog subsystem of a microphone array having an integral self-calibration system. FIG. 7 provides an exemplary circuit diagram for a pulse injection circuit for the integral self-calibration system of FIG. 6. FIG. 8 provides an exemplary operational flow diagram for injecting an excitation pulse into a preamplifier and measuring the preamplifier output for the pulse injection circuit of FIG. 7. FIG. 9 provides an exemplary operational flow diagram which illustrates the collection of preamplifier outputs from a predetermined number of input excitation pulses for the preamplifier output measurement flow diagram of FIG. 8. FIG. 10 is a graph which illustrates an exemplary excitation pulse input to a preamplifier. FIG. 11 is a graph which illustrates a typical preamplifier output response to the exemplary excitation pulse of FIG. 10. FIG. 12 is a graph which illustrates a typical preamplifier output magnitude response computed from a frequency-domain analysis of the preamplifier output of FIG. 11. FIG. 13 is a graph which illustrates a typical preamplifier output phase response (in degrees) computed from a frequency-domain analysis of the preamplifier output of FIG. 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the preferred embodiments of the present invention, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. 1.0 Exemplary Operating Environment: FIG. 1 illustrates an example of a suitable computing system environment 100 with which the invention may be implemented. The computing system environment 100 is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing environment 100 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment 100. The invention is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable for use with the invention include, but are not limited to, personal computers, server computers, hand-held, laptop or mobile computer or communications devices such as cell phones and PDA's, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like. The invention may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer in combination with hardware modules, including components of a microphone array 198. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices. With reference to FIG. 1, an exemplary system for implementing the invention includes a general-purpose computing device in the form of a computer 110. Components of computer 110 may include, but are not limited to, a processing unit 120, a system memory 130, and a system bus 121 that couples various system components including the system memory to the processing unit 120. The system bus 121 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus. Computer 110 typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by computer 110 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, PROM, EPROM, EEPROM, flash memory, or other memory technology; CD-ROM, digital versatile disks (DVD), or other optical disk storage; magnetic cassettes, magnetic tape, magnetic disk storage, or other magnetic storage devices; or any other medium which can be used to store the desired information and which can be accessed by computer 110. Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media. Combinations of any of the above should also be included within the scope of computer readable media. The system memory 130 includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) 131 and random access memory (RAM) 132. A basic input/output system 133 (BIOS), containing the basic routines that help to transfer information between elements within computer 110, such as during start-up, is typically stored in ROM 131. RAM 132 typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 120. By way of example, and not limitation, FIG. 1 illustrates operating system 134, application programs 135, other program modules 136, and program data 137. The computer 110 may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only, FIG. 1 illustrates a hard disk drive 141 that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive 151 that reads from or writes to a removable, nonvolatile magnetic disk 152, and an optical disk drive 155 that reads from or writes to a removable, nonvolatile optical disk 156 such as a CD ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive 141 is typically connected to the system bus 121 through a non-removable memory interface such as interface 140, and magnetic disk drive 151 and optical disk drive 155 are typically connected to the system bus 121 by a removable memory interface, such as interface 150. The drives and their associated computer storage media discussed above and illustrated in FIG. 1, provide storage of computer readable instructions, data structures, program modules and other data for the computer 110. In FIG. 1, for example, hard disk drive 141 is illustrated as storing operating system 144, application programs 145, other program modules 146, and program data 147. Note that these components can either be the same as or different from operating system 134, application programs 135, other program modules 136, and program data 137. Operating system 144, application programs 145, other program modules 146, and program data 147 are given different numbers here to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer 110 through input devices such as a keyboard 162 and pointing device 161, commonly referred to as a mouse, trackball, or touch pad. Other input devices (not shown) may include a joystick, game pad, satellite dish, scanner, radio receiver, and a television or broadcast video receiver, or the like. These and other input devices are often connected to the processing unit 120 through a wired or wireless user input interface 160 that is coupled to the system bus 121, but may be connected by other conventional interface and bus structures, such as, for example, a parallel port, a game port, a universal serial bus (USB), an IEEE 1394 interface, a Bluetooth™ wireless interface, an IEEE 802.11 wireless interface, etc. Further, the computer 110 may also include a speech or audio input device, such as a microphone or a microphone array 198, as well as a loudspeaker 197 or other sound output device connected via an audio interface 199, again including conventional wired or wireless interfaces, such as, for example, parallel, serial, USB, IEEE 1394, Bluetooth™, etc. A monitor 191 or other type of display device is also connected to the system bus 121 via an interface, such as a video interface 190. In addition to the monitor, computers may also include other peripheral output devices such as a printer 196, which may be connected through an output peripheral interface 195. The computer 110 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 180. The remote computer 180 may be a personal computer, a server, a router, a network PC, a peer device, or other common network node, and typically includes many or all of the elements described above relative to the computer 110, although only a memory storage device 181 has been illustrated in FIG. 1. The logical connections depicted in FIG. 1 include a local area network (LAN) 171 and a wide area network (WAN) 173, but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets, and the Internet. When used in a LAN networking environment, the computer 110 is connected to the LAN 171 through a network interface or adapter 170. When used in a WAN networking environment, the computer 110 typically includes a modem 172 or other means for establishing communications over the WAN 173, such as the Internet. The modem 172, which may be internal or external, may be connected to the system bus 121 via the user input interface 160, or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer 110, or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation, FIG. 1 illustrates remote application programs 185 as residing on memory device 181. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. The exemplary operating environment having now been discussed, the remaining part of this description will be devoted to a discussion of the hardware and software modules and processes embodying a self-calibration system and method for automatically determining frequency-domain compensation gains for each preamplifier in a microphone array. 2.0 Introduction: Conventional microphone arrays typically include an arrangement of one or more microphones in some predetermined layout. In general, each microphone in these arrays typically includes an associated preamplifier for providing amplification or gain for analog audio signals captured by each microphone. An analog preamplifier measurement system for a microphone array, as described herein, builds on conventional microphone arrays by providing an integral “self-calibration system.” In general, this integral self-calibration system automatically determines frequency-domain responses of each preamplifier in the microphone array, and computes frequency-domain compensation gains for matching the output of each preamplifier. As a result, there is no need to predetermine exact operational characteristics of each channel of the microphone array, or to use expensive matched electronic components. Further, as is well known to those skilled in the art, individual microphone operational characteristics, as well as the characteristics of most other electrical components, tend to change both over time and as a function of local temperature. Consequently, use of the integral self-calibration system provides current operational parameters of the microphones and associated preamplifiers within the microphone array which better reflect actual component parameters than factory measured values which are typically coded into conventional microphone arrays or audio processing software. In general, the integral self-calibration system is capable of automatically determining the frequency response, sensitivity and gain of the individual channels (microphone plus preamplifier) in the microphone array. Typically, the integral self-calibration system may be operated at any time that calibration of the microphone or microphones in the array is desired. Further, in other embodiments, the integral self-calibration system of the microphone array operates automatically either upon connection to an external computing device, upon regular or user-specified intervals, or simply upon command. In general, the integral self-calibration system operates by automatically injecting an excitation pulse of a known magnitude and phase to all preamplifier inputs within the microphone array. Note that the duration of the pulse should be larger than the preamplifier step response so as to avoid or minimize any effects resulting from transient responses. The resulting analog waveform from each preamplifier output is then measured. A frequency analysis, such as, for example, a Fourier or Fast Fourier Transform (FFT), or other conventional frequency analysis, of each of the resulting waveforms is then performed. The results of this frequency analysis are then used to compute frequency-domain compensation gains (e.g., magnitude and phase gains) for each preamplifier for matching or balancing the responses of all of the preamplifiers with each other. Once computed, these frequency-domain compensation gains can then be applied to the output of each corresponding preamplifier when processing actual audio inputs of the microphones associated with each preamplifier. This serves to make the output from each of the preamplifiers consistent, given the same or similar input to any of the microphones in the array. Consequently, using these computed frequency-domain compensation gains, audio processing software such as, for example, software for performing sound source localization, beam forming, acoustic echo cancellation, noise suppression, etc., can easily compensate for phase response mismatches across all preamplifiers. Without this compensation, any phase response mismatches would reduce the performance of the audio processing software. Therefore, as a result of computing and providing these frequency-domain compensation gains for each preamplifier, there is no need to use expensive matched electrical components. Further, inexpensive generic microphones and preamplifier combinations can have gain differences on the order of about +/−4 dB or more due to manufacturing variances. Consequently, one advantage offered by the integral self-calibration system described herein is that microphone arrays using this integral self-calibration system may be inexpensively produced by using relatively inexpensive non-matched electrical components including, for example, microphones, preamplifiers, transistors, capacitors, resistors, op amps, etc. 2.1 System Overview: The integral self-calibration system described herein is applicable for use with most types of microphones or microphone arrays. Further, in one embodiment, the integral self-calibration system is included in a “self-descriptive microphone array,” as described in a copending patent application entitled “SELF-DESCRIPTIVE MICROPHONE ARRAY,” having a filing date of TBD, and assigned Serial Number TBD, the subject matter of which is incorporated herein by this reference. In this embodiment the injection of pulses, readings of the preamplifier outputs, and computation of the frequency analysis, are all performed by driver software residing in the external computing device connected to the microphone array. In particular, in this embodiment, the frequency analysis for computing the frequency-domain compensation gains for each preamplifier is performed by an external computing device, such as a PC-type computer, or other computing device, coupled to the microphone array via a conventional computer interface. One advantage of this embodiment is that because the microphone array makes use of external processing power, there is no need to include relatively expensive onboard signal processing software or hardware capabilities within the array itself. Consequently, the self-descriptive microphone array is relatively inexpensive to manufacture in comparison to conventional microphone array devices that include onboard audio processing capabilities. Note that the connection between the self-descriptive microphone array and the external computing device is accomplished using any of a variety of conventional wired or wireless computer interfaces, including, for example, serial, parallel, IEEE 1394, USB, IEEE 802.11, Bluetooth™, etc. In another embodiment, as described in the aforementioned copending patent application entitled “SELF-DESCRIPTIVE MICROPHONE ARRAY,” the microphone array further includes a “microphone array memory” that is integral to the microphone array. This microphone array memory includes any type of non-volatile memory, such as, for example a ROM, PROM, EPROM, EEPROM, or other conventional non-volatile memory type or device, which contains a microphone array device description. This device description includes parametric information, including the computed frequency-domain compensation gains for each preamplifier, which defines operational characteristics and configuration of the microphone array. The microphone array device description within the microphone array memory is then automatically updated, whenever the integral self-calibration system is activated, to reflect actual configuration of particular elements of the microphone array. In operation, the device description of the microphone array is then automatically reported to the external computing device via a microphone array interface (i.e., the conventional computer interface, as noted above). In this embodiment, once the microphone array device description is provided to the external computing device, the external computing device then uses the device description to automatically configure audio processing software residing within the external computing device for processing one or more audio signals captured by the microphone array. Specifically, software applications residing within the external computing device, such as DLL's or other software drivers or programs, interpret physical parameters of the microphone array, including the frequency-domain compensation gains, that are provided by the microphone array device description. These software applications then communicate the physical parameter data of the microphone array to signal processing software residing within the external computing device. This allows the signal processing software to automatically adjust its operational parameters to the characteristics of the attached microphone array to perform automatically optimized audio processing computations. As noted above, preamplifiers are associated with each microphone in the microphone array. Further, to allow for multiple simultaneous channels of audio to be captured by the microphone array, one or analog-to-digital (A/D) converters are also associated with each microphone. Audio signals captured by the microphone array are then pre-amplified (i.e., gain) and converted to a digital signal via the A/D converters and provided, via the aforementioned wired or wireless computer interface, to the audio processing software residing within the external computing device for further processing, as desired. The maximum number of digital audio channels that can then be transmitted via the computer interface is then only limited by the maximum bandwidth of that computer interface in combination with the digital sampling rate of each channel of the microphone array. In another embodiment, in addition to including one or more microphones, the microphone array also includes one or more loudspeakers for reproducing one or more audio signals. For example, many microphone arrays, such as those arrays used for audio conferencing, frequently include both microphones and speakers. The microphones capture sound, and the speakers play back sound. Generally, conventional audio conferencing-type microphone arrays also include relatively expensive onboard acoustic echo cancellation capabilities so that local audio signals are not endlessly echoed during an audio conference. However, in the context of the aforementioned “self-descriptive microphone array,” audio processing, such as acoustic echo cancellation, is performed via the audio processing software residing within the external computing device. Audio to be played back via the self-descriptive microphone array is then simply transmitted from the external computing device to the array via the aforementioned wired or wireless computer interface. In this embodiment, as with the parametric information defining the microphones and preamplifiers within the microphone array, parametric information defining the speakers within the microphone array is also stored within the microphone array memory. Configuration of the microphone array is then reported, as noted above, to allow for automatic configuration of the audio processing software residing within the external computing device to which the microphone array is connected. 2.2 System Architecture: The processes summarized above are illustrated by the general system diagram of FIG. 2. In particular, the system diagram of FIG. 2 illustrates the interrelationships between hardware and software modules for implementing an integral self-calibration system for a microphone array. It should be noted that any boxes and interconnections between boxes that are represented by broken or dashed lines in FIG. 2 represent alternate embodiments of the integral self calibration system and the microphone array described herein, and that any or all of these alternate embodiments, as described below, may be used in combination with other alternate embodiments that are described throughout this document. In general, the microphone array includes a microphone module 200 comprising one or more microphones, such as, for example, conventional electret microphones, along with circuitry for amplifying analog audio signals captured by the microphone module 200, and for converting the analog signals to a digital format. In particular, amplification of captured signals is provided by a preamp module 210 comprising one or more preamplifier circuits which provide gain for amplifying the captured audio signals. An A/D conversion module 220 then provides one or more A/D converters for converting analog signals captured by the microphones into digital signals for transmission to an external computing device 290 via a microphone array input/output module 250, which provides for conventional data transmission via one of the aforementioned wired or wireless computer interfaces. Further, in one embodiment, the microphone module 200, preamp module 210, and A/D conversion module 220, are combined into one module (not shown) in the case of microphones such as a MEMS microphone. For example, as is well known to those skilled in the art, a Micro-Electro-Mechanical-Structure (MEMS) type microphone is basically an integrated circuit, typically very small in size, which includes a microphone and preamplifier, and in some cases, A/D conversion within a single circuit or microchip. The use of MEMS-type microphones in the microphone array described herein allows for a further reduction in components by using an integrated circuit which combines each of the preamp module 210, A/D conversion module 220, and microphone module 200 into one module which then provides the operational capability of the three separate modules. Consequently, because the same functionality is provided by a MEMS-type microphone as is provided by use of the separate modules, i.e., the microphone module 200, preamp module 210, and A/D conversion module 220, the microphone array will be described in the context of these three modules. However, it should be understood that the use of MEMS-type microphone technology is inherent in the description of these three modules. In addition, as noted above, the microphone array also includes an integral self-calibration system. This self calibration is embodied in a “microphone array self-calibration module” 240. As described in greater detail below in Section 3, this self-calibration module 240 injects one or more pulses of known magnitude and phase into an input of each preamplifier in the microphone array. The output response from each preamplifier is then measured and used to compute the frequency-domain compensation gains for each preamplifier. Further, as described in the aforementioned copending patent application entitled, “SELF-DESCRIPTIVE MICROPHONE ARRAY,” one embodiment of the microphone array includes a “microphone array memory module” 230 which stores and reports parametric information which defines operational characteristics and configuration of the microphone array, including the computed frequency-domain compensation gains for each preamplifier. In general, the memory module 230 uses any type of conventional non-volatile memory or storage, such as, for example, ROM, PROM, EPROM, EEPROM, etc. The parametric information stored within the memory module 230 is then reported to an external computing device 290, either upon connection of the microphone array to the external computing device, or upon a manual or automatic request for the information originating with the external computing device. As described herein, reporting of this parametric information allows for automatic configuration of audio processing software residing within the external computing device 290 for processing audio signals either captured by the microphone array, or in one embodiment, audio signals that are to be played back by one or more loadspeakers residing within the microphone array. In one embodiment, the parametric information stored in the microphone array memory module 230 is maintained in a lookup table which includes parametric information describing the configuration of the microphone array. In general, this lookup table, or other means of storage, includes one or more of the following elements of parametric information: 1) microphone array manufacturer, model, and version; 2) microphone types and position; 3) microphone array working volume (i.e., where the sound source is expected to be); 4) microphone gain calibration (i.e., the computed frequency-domain compensation gains for each preamplifier); and 5) speaker configuration for any speakers included in microphone array. Further, also as noted above, one embodiment of the microphone array includes a set of one or more speakers. This embodiment also includes one or more digital-to-analog (D/A) converters and one or more amplifiers. In particular, in this embodiment, a D/A conversion module 260 provides one or more D/A converters for performing digital-to-analog conversion of one or more digital signals provided by the external computing device 290 via the microphone array input/output module 250. An amplifier module 270 then provides amplification of the converted analog signals. These analog signals are then provided to a speaker module 280 for playback. In particular, the speaker module 280 includes one or more speakers for reproducing the amplified analog audio signals. Again, in this embodiment, the microphone array memory module 230 further includes parametric information defining physical characteristics of the speakers within the microphone array. 3.0 Operation Overview: The above-described hardware and software modules are employed for implementing the integral self-calibration system for the microphone array. As summarized above, this integral self-calibration system enables automatic computation of frequency-domain compensation gains of the microphone array to allow automatic configuration and optimization of audio processing software residing within the external computing device. The following sections provide a detailed discussion of the architecture (FIG. 3) and operation (FIG. 4) of the microphone array, and of exemplary methods for implementing the hardware and software modules described in Section 2. In addition, the following sections also include a detailed discussion of the operation of the integral self-calibration system and method (FIG. 5). It should be noted that any boxes and interconnections between boxes that are represented by broken or dashed lines in any of FIG. 3, FIG. 4, or FIG. 5, represent alternate embodiments of the integral self-calibration system and the microphone array described herein, and that any or all of these alternate embodiments, as described below, may be used in combination with other alternate embodiments that are described throughout this document. 3.1 Microphone Array Architecture: The processes described above with respect to FIG. 2 are illustrated by the general architectural diagram of FIG. 3. In particular, FIG. 3 illustrates an exemplary architectural layout of hardware representing one embodiment of the microphone array. For example, as illustrated by FIG. 3, a microphone array 300 comprises an array 305 of one or more microphones (310 through 325). Further, the array 305 of microphones included in the microphone array 300 also includes one or more preamplifiers 330 for providing gain or preamplification of each microphone (310 through 325). In a related embodiment, the array 305 further includes one or more Analog-to-Digital (A/D) converters 335 for digitizing an analog audio input from each microphone (310 through 325). Note that both preamplifiers and A/D converters are well known and understood by those skilled in the art, and will not be described in detail herein. In addition, as described in the aforementioned copending patent application entitled “SELF-DESCRIPTIVE MICROPHONE ARRAY,” one embodiment of the microphone array 300 also includes a microphone array memory 340 which contains parametric information that defines operational characteristics and configuration of the microphone array. The microphone array 300 also includes at least one external interface 350, including, for example, serial, parallel, IEEE 1394, USB, IEEE 802.11, Bluetooth™, etc., for connecting the microphone array to an external computing device 290. As noted above, the microphone array 300 also includes a self calibration system 345 which automatically determines a current state of one or more of the components of the microphone array. This current state is then used to automatically update one or more of the operational characteristics stored in the microphone array memory 340. For example, in one embodiment, the self calibration system 345 automatically measures preamplifier 330 impulse responses. In general, this determination is made by providing a “pulse injection circuit” for injecting a precise low-amplitude pulse of known magnitude and phase at the input of each preamplifier 330. The precise impulse response of each preamplifier 330 is then measured for computing frequency-domain compensation gains for each preamplifier. These computed frequency-domain compensation gains then serve to provide a consistent output from each amplifier regardless of the operational characteristics of each microphone/preamplifier combination. Repeating this process for each preamplifier and storing the resulting preamplifier 330 frequency-domain compensation gains in the microphone array memory 340 allows for precise configuration of audio processing software residing on the external computing device 290 using the frequency-domain compensation gains for each preamplifier. One clear advantage of this embodiment is that by knowing a precise frequency-domain compensation gain for each preamplifier 330, software drivers associated with audio processing software residing on the external computing device 290 can then easily compensate for phase response mismatches across all preamplifiers. Without compensation, such mismatches would reduce the performance of certain audio processing applications. For example, the performance of conventional beamforming or sound source localization (SSL) digital signal processing software, which combines all microphone signals to provide a relatively narrow capture direction selectivity, will be significantly improved by compensating for the precise phase response of each preamplifier 330. Note that the self calibration system 345 for the microphone array 300 is described in further detail below in Section 3.2.1 with respect to FIG. 5, and in the working example provided in Section 4 with respect to FIG. 6 through FIG. 13. Finally, in yet another embodiment, the microphone array 300 includes a loadspeaker system 355. In general, this speaker system 355 includes one or more speakers, one or more D/A converters, and one or more amplifiers for amplifying analog audio signals prior to playback by the speakers included in the speaker system. In this embodiment, audio signals provided by the external computing device 290 via the microphone array interface 350 are first converted to analog signals, amplified, and then reproduced by providing the amplified analog audio signals to the speakers of the speaker system 355. 3.2 Microphone Array Operation: In one embodiment, as illustrated by FIG. 4, the microphone array described above operates by first connecting the microphone array to the external computing device (Box 400). As noted above, this connection is accomplished using a conventional wired or wireless computer interface, such as, for example, serial, parallel, IEEE 1394, USB, IEEE 802.11, Bluetooth™, etc., for connecting the microphone array to the external computing device. In one embodiment, once connected, self-calibration (Box 405) of the microphone array is initiated. In a tested embodiment, this self-calibration is performed automatically (Box 410) as soon as the microphone array is connected to the external computing device (Box 400). In a related embodiment, the self-calibration is performed immediately upon manual user request (Box 415), said request being provided from the external computing device via the computer interface. In another related embodiment, the self-calibration is performed immediately upon an external request (Box 420), such as, for example, a request generated by one an audio processing software program operating on the external computing device. Again, as with the manual request (Box 415), the external request (Box 420) is provided from the external computing device via the computer interface. In each of these embodiments, i.e., automatic, manual, or externally requested self-calibration, the microphone array device description automatically updates (Box 425) the microphone array parametric information 340 to reflect the current state of the microphone array as determined via the self-calibration procedure described in detail in Section 3.2.1. At this point, the parametric information 340 defining the current state of the microphone array is reported (Box 435) to the external computing device. As noted above, given the known operational characteristics of the components of the microphone array (i.e., microphone, speakers, preamps, etc.), audio processing software operating within the external computing device is automatically optimized and/or configured (Box 440) to provide a computing environment that is specifically tailored to the known parameters of the microphone array connected to the external computing device. For example, assuming a microphone array with two microphones, where one of the microphone channels has a gain of +4 dB more than the other microphone channel, the input received by either or both of the microphones is then weighted by a factor designed to compensate for this difference in gain so that the input provided by either of the microphones will be nominally equivalent. As a result of such adjustments, conventional processing of audio captured by the microphone array is significantly improved relative to audio processing without weighting the audio inputs to reflect actual microphone array configurations. Once the audio processing software has been optimally configured, one or more audio signals are captured by the microphone array and provided to the external computing device, via the aforementioned computer interface, for audio processing, as desired (Box 445). Such processing may include, for example, conventional sound source localization, beam forming, acoustic echo cancellation, noise suppression, etc. Note that as such audio processing techniques are well known to those skilled in the art, they will not be described in detail herein. Finally, in one embodiment, the device description including the microphone array parametric information 340 is updated at any time during the above-described processes by requesting a self-calibration, either manually, or via an external request, as described below. 3.2.1 Microphone Array Self-Calibration: As noted above, the microphone array includes an integral self-calibration system. In general, this integral self-calibration system is intended to compensate for using relatively inexpensive non-matched electronic components in the construction of the microphone array by automatically determining frequency-domain responses of each preamplifier in the microphone array, and then computing frequency-domain compensation gains for matching the output of each preamplifier. However, this same self-calibration system also serves to compensate for any changes in the electrical properties of the preamplifier circuits in the microphone array as a result of temperature or age related effects on the electrical components in the array. As noted above, in one embodiment, each of the microphones remain live for receiving audio signals during injection of the excitation pulse into each preamplifier. Conversely, in one embodiment, as illustrated by FIG. 5, the integral self-calibration system begins operation by first switching off each microphone input to each corresponding preamplifier (Box 500). However, it should be noted that, as discussed below, this step may be omitted, especially in the case where the output of multiple pulses is averaged and used for computing the frequency-domain compensation gains for each preamplifier. Next, whether or not the microphones remain live, an excitation pulse of known magnitude and phase is automatically generated by a “preamplifier pulse test circuit” and injected into each preamplifier (Box 510). As is well known to those skilled in the art, there are a large number of methods for generating a pulse of known magnitude and phase for a given period of time. Consequently, rather than providing an exhaustive list of such methods, one such method, as used in the tested embodiment of the working example described in Section 4, will be discussed. However, it should be understood that the particular pulse generation method described below is not intended to limit the scope of the integral self-calibration system described herein, and is provided for purposes of explanation only. For example, as discussed in further detail with respect to the working example provided in Section 4 with respect to FIG. 7, in one embodiment, the excitation pulse is generated using a “preamplifier pulse test circuit” which generates a low amplitude pulse of a predetermined duration. In this tested embodiment, the preamplifier pulse test circuit includes a conventional NPN-type transistor which simply acts as an open switch until a voltage corresponding to a digital “1” (i.e., approximately 3 volts) is applied to the preamplifier pulse test circuit. Once this voltage is applied, the NPN-type transistor switch closes and a low amplitude analog waveform pulse (i.e., the excitation pulse) is generated by the preamplifier pulse test circuit. This excitation pulse is generated for as long as the NPN-type transistor switch is closed (i.e., for as long as the voltage corresponding to a digital “1” continues to be applied). Note that the period of the excitation pulse should be longer than the preamplifier step response. For example, given a preamplifier step response duration of approximately 30 ms, an excitation pulse on the order of about 50 ms was found to provide sufficient frequency-domain information to compute the frequency-domain compensation gains for each preamplifier. Once the excitation pulse generated by the preamplifier pulse test circuit is input into each of the preamplifiers in the microphone array, each preamplifier then amplifies the low-amplitude excitation pulse injected from the preamplifier pulse test circuit to output a high-amplitude voltage waveform. Each preamplifier output is then measured (Box 520) by simply recording the actual output level of each preamplifier. Note that in one embodiment, conventional A/D converters are used to convert each analog preamplifier response to a set of digital values (see for example FIG. 2 and FIG. 3, and the corresponding A/D conversion discussion). These digital values are then simply recorded. A frequency analysis of at least part of the preamplifier output resulting from the excitation pulse is then performed (Box 530). For example, a conventional FFT-type frequency analysis will provide magnitude, frequency and phase information for the resulting preamplifier output. Clearly, as should be appreciated by those skilled in the art, there are a number of well-known conventional methods for determining frequency-domain information from a signal. However, for purposes of clarity of discussion, the discussion of the frequency analysis will assume an FFT analysis of the preamplifier responses. Given the FFT analysis of each preamplifier output, frequency domain compensation gains are then computed (Box 540) for each preamplifier. In particular, because the exact frequency-domain response of each preamplifier is known, it is a simple matter to compute frequency-domain magnitude and phase gains for each individual preamplifier, such that the magnitude frequency-domain response of all of the preamplifiers will be closely matched once the gains computed for each individual preamplifier are applied to the output of each individual preamplifier. The computed frequency domain compensation gains for each preamplifier are then stored in a table or array 550 of frequency domain compensation gains that is then made available for use by audio processing software. In addition, as noted above, in one embodiment, the microphone array parametric information is stored in the microphone array memory 340 (see FIG. 2 and FIG. 3) which contains parametric information that defines operational characteristics and configuration of the microphone array. In this embodiment, the computed frequency domain compensation gains are used to update the microphone array device description 425 by storing the computed frequency domain compensation gains in the microphone array memory 340. At this point, a determination is made as to whether additional excitation pulses are to be injected into the preamplifiers (Box 560). For example, as discussed above, in one embodiment, multiple pulses are injected into the preamplifiers. As a result, each preamplifier will have a computed frequency domain compensation gain for each pulse. In this embodiment, the computed frequency domain compensation gains for each preamplifier are simply averaged (Box 570). One advantage of using multiple pulses is that averaging of the frequency domain compensation gains tends to minimize any effects resulting from background noise or transients when the microphones are left live. Consequently, the microphone array can be constructed without microphone switching circuitry since there is no need to turn off the microphones for excitation pulse injection in this embodiment. If additional excitation pulses are to be injected (Box 560), then the steps described above for the case of a single excitation pulse are simply repeated bor each additional excitation pulse. Alternately, if no additional; excitation pulses are to be injected into the preamplifiers, then, if the microphones have been switch off (Box 500) they are simply switched back on (Box 580). Self-calibration of the microphone array is complete at this point. 4.0 Working Example: A tested embodiment of the microphone array with the integral self-calibration system and method is illustrated by FIG. 6 through FIG. 13. It should be noted that the following discussion and the associated figures are provided for purposes of explanation, and that the embodiments described with respect to FIG. 6 through FIG. 13 illustrate only one possible implementation of the system and method described herein. In general, FIG. 6 provides an exemplary basic circuit diagram for a microphone array 00, as described herein. Specifically, as illustrated by FIG. 6, the microphone array 600 includes one or more input channels. Note that only three channels are illustrated (Mic 1, Mic 2, and Mic N), however, the microphone array can have as many channels as desired by simply repeating the circuit illustrated by Mic 1 (i.e., circuit 610). As noted above, each input channel comprises at least a microphone and a preamplifier circuit, 610, 620, or 630. Each input channel is nominally the same, however, as non-matched electrical components may be used in the construction of the microphone array, it is to be expected that each channel of the microphone array will have different operational characteristics. Consequently, as described above, the computed frequency domain compensation gains for each preamplifier are used to compensate for phase response mismatches between each channel. The preamplifier circuit in FIG. 6 uses a configuration that allows a single operational amplifier (OP AMP) to provide both amplification and highpass filtering functions. Specifically, this exemplary circuit was designed to provide a third-order highpass frequency response to ensure that low frequencies (below a predetermined cutoff frequency, for example 50 Hz) are significantly attenuated. Such filtering serves to remove high-amplitude low-frequency noises that are often present in a meeting room environment (e.g., air flow in air conditioning vents, computer fans, etc.). FIG. 6 also shows a set of A/D converters 640, one for each input channel (610, 620, and 630). As noted above, the A/D converters simply digitize the output of each channels preamplifier for transmission via the microphone array interface 350 to the external computing device for further processing. FIG. 7 illustrates an extension to the basic circuit diagram of FIG. 6. In particular, FIG. 7 includes a modified bias circuit 700 and a preamplifier pulse test circuit 720 for generating and injecting the excitation pulse into each preamplifier 710 (also 610, 620, or 630 from FIG. 6). The modified bias circuit 700 allows the connection of an electret microphone with either high output signal level (such as omnidirectional microphones) or an electret microphone with low output signal level (such as unidirectional microphones). In general, the pulse injection circuit 720 in FIG. 7 uses a conventional NPN-type bipolar transistor as an analog “switch.” In particular, controlled by a digital pulse, as described below, the pulse injection circuit 720 injects a low-amplitude analog pulse at the input of the preamplifier 620. This allows a software driver residing on the aforementioned remote computing device to trigger the excitation pulse (via the computer interface to the microphone array) and to measure the response of the preamplifier to that pulse. In particular, in this tested embodiment, triggering the excitation pulse is accomplished by injecting a digital “1”, approximately +3V, at point A (750) which triggers the NPN-type transistor to close the “switch.” As a result of closing this switch, the excitation pulse is generated by the preamplifier pulse test circuit 720 and provided to the preamplifier 710. As described above, a conventional A/D converter is then used to measure the response of the preamplifier 710 output at point B 740. In particular, as noted above, to measure the frequency response of all preamplifiers, the software driver forces a digital pulse signal through point A 750 in the circuit illustrated in FIG. 7. That pulse is obtained from one of the pins in the computer interface between the remote computing device and the microphone array. The preamplifier pulse test circuit, with a single NPN transistor and a few discrete components, acts as an analog switch controlled by the digital pulse in point A 750. The voltage at point A is nominally at digital “0” (near 0 V), so that the transistor is effectively an open switch, and does not interfere with normal operation of the preamplifier. During the pulse, the voltage at A it is momentarily (typically for 50 milliseconds) brought to digital “1” (near 3V). During that “1” pulse, the transistor effectively closes, generating a very low amplitude pulse at the preamplifier input 710 (note that the microphone elements don't need to be disconnected from the input, as discussed herein). The preamplifier 710 then amplifies that low-amplitude pulse at its input, and generates a high-amplitude voltage waveform at point B 740. That waveform is digitized by the A/D converter, and read out by the software driver. For example, FIG. 8 provides an exemplary operational flow diagram for injecting an excitation pulse into a preamplifier and measuring the preamplifier output for the pulse injection circuit of FIG. 7. In particular, given the output of the preamplifier as a result of the excitation pulse, A/D conversion is initialized 800 to provide a digital measurement of the magnitude of the preamplifier response as a function of time. The system then waits a short time period, T0, 810 on the order of about 2 ms or so to ensure that the A/D conversion has been fully initialized. At this point, a digital “1” is applied 820 to point A of the preamplifier pulse test circuit illustrated in FIG. 7. As discussed above, this digital “1” serves to close the NPN transistor acting as an analog switch and to generate the excitation pulse that is then provided to the preamplifier. The application of the digital “1” is continued for a period of time TP 830. This time period, Tp, represents the excitation pulse duration, and is a predetermined period that is larger than the duration of the preamplifier step response. In this tested embodiment, the preamplifier step response was approximately 30 ms. Consequently, in this tested embodiment, TP was set to 50 ms. Once the time period Tp has passed, the digital “1” is removed from point A of the preamplifier pulse test circuit illustrated in FIG. 7, and a digital “0” is instead applied at this point. As discussed above, this digital “0” serves to open the NPN transistor acting as an analog switch and to terminate the generation of the excitation pulse provided to the preamplifier. Once this digital “0” is applied, A/D conversion of the preamplifier response to the excitation pulse is finished 850, and the resulting digitized response values are stored 860 for use in the aforementioned frequency-domain analysis of the preamplifier response. FIG. 9 builds on the basic single pulse flow diagram of FIG. 8 by providing for the accumulation of the preamplifier outputs to multiple pulses. In particular, since each measurement takes only about 100 ms, as shown in FIG. 10, during a period of, for example, 5 seconds, the software driver can make a set of N=50 measurements. The software driver then adds the results of all those measurements to an accumulator, as illustrated by steps 900 through 950 of the flow diagram of FIG. 9. As discussed above, the accumulated preamplifier response values are then averaged and used for computing the frequency-domain compensation gains for matching the output of each preamplifier. Averaging N measurements effectively filters out noises or other transients that might disturb the measurement. As noted previously, there is no need to disconnect or switch off the microphones in the array during the preamplifier response measurements. In particular, since each measurement generates different noise patterns, averaging N measurements with N large enough (e.g. 50 measurements) reduces the effects of such noises to negligible levels. FIG. 10 shows the typical waveforms at point A (pulse driving digital input) while FIG. 11 shows a typical preamplifier analog output at point B of the general circuit diagram of FIG. 7. Note that in this tested embodiment, it can be seen that the highpass filtering response of the preamplifier has significantly attenuated the flat portion of the pulse in the preamplifier analog output at point B. This is typical behavior for such highpass filtering. Note that the second pulse of the preamplifier output response at point B (at approximately 52 ms, and having a sharp positive attack and a small negative sidelobe) is the preamplifier step response that is actually used in the aforementioned frequency-domain analysis. From that portion of the response, the frequency response of the preamplifier is easily computed by applying an FFT to that waveform. In general, FIG. 12 illustrates the results of a frequency-domain analysis of the preamplifier output waveform of FIG. 10. In particular, FIG. 12 illustrates a typical magnitude response of the preamplifier. Similarly, FIG. 13 illustrates the phase response, with “d” indicating degrees, as determined by the frequency-domain analysis of the preamplifier output of FIG. 10. Specifically, FIG. 12 and FIG. 13 show the results of an FFT analysis of the pulse response output signal of FIG. 10. These figures indicate both the amplitude and phase responses at each frequency. As noted above, the aforementioned software driver computes those responses for all preamplifier channels, and stores them in tables, allowing a precise compensation of any differences in responses among channels. The foregoing description of the self-calibration system and method for automatically determining frequency-domain compensation gains for each preamplifier in a microphone array has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. Further, it should be noted that any or all of the aforementioned alternate embodiments may be used in any combination desired to form additional hybrid embodiments of the self-calibration system for the microphone array. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. | <SOH> BACKGROUND <EOH>1. Technical Field The invention is related to a microphone array preamplifier measurement system, and in particular, to a system and method for automatically determining gain variations between one or more analog microphone/preamplifier channels in a microphone array and a system and method for automatically compensating for such gain variations to provide for improved processing of audio signals captured via the microphone array. 2. Related Art Conventional microphone array type devices are well known to those skilled in the art. In general, microphone arrays typically include an arrangement of microphones in some predetermined layout. These microphones are generally used to capture sounds from various directions and originating from different points of the space. Once captured, onboard sound processing software and hardware then provides sound processing capabilities, such as, for example, sound source localization, beam forming, acoustic echo cancellation, noise suppression, etc. For example, one common use for such arrays involving audio conferencing systems is to determine the direction of a dominant speaker in a room having both active speech and other noise, and then to process the input from the various microphones in the array accordingly. In particular, given the input from each of the microphones in the array, conventional beam forming and sound source localization computations are used to localize the position and direction of the person currently speaking. With this information, it is then possible to filter out all sounds not coming from the direction of the speaker, thereby improving the overall quality of the captured sound with respect to the person speaking. In general, such microphone arrays typically include one or more sets of matched microphone/preamplifier combinations. In other words, the electronic components, i.e., microphones, preamplifier circuits, etc., within such microphone arrays are carefully chosen so that that the frequency responses of the various microphone/preamplifier combinations within the microphone array are as close as possible to one another for any particular audio input. Matching the gains and frequency responses among the preamplifier circuits is important because variations across channels degrade the performance of the aforementioned beam forming and sound source localization algorithms. Unfortunately, choosing electronic components for matching the frequency response of the various microphone/preamplifier combinations within a microphone array is typically rather expensive, thereby increasing the cost of such microphone arrays. For example, choosing electronic components with matching responses is typically accomplished either through the careful testing of a large batch of individual electronic components to identify those with matching properties, or through the use of relatively expensive high-precision electronic components (capacitors, resistors, op amps, etc.) that are guaranteed to have particular electrical properties within some small tolerance. Both cases tend to significantly increase the cost of matched sets of microphone/preamplifier combinations for a microphone array. Further, in the case where inexpensive electronic components of some nominal tolerance are used there will likely be a relatively wide variation in the frequency response of each microphone/preamplifier combination within the microphone array. As a result, in order to achieve optimal audio processing performance, the response of each individual microphone/preamplifier combination within the microphone array must be pre-determined, and any software designed to process audio signals captured by the microphone array must then be specifically tailored to the specific operational parameters of each microphone/preamplifier combination within that array. Consequently, each such microphone array typically requires customized software, thereby increasing both test time and cost to manufacture individual microphone arrays. Further, the operational parameters of individual electronic components in a microphone array tend to change, if even only slightly, over time, and relative to the local temperature of such electronic components. Therefore, software tailored to a particular microphone array configuration may still produce sub-optimal audio processing results where the parameters of the microphone array fail to precisely match the expected operational parameters coded into any associated audio processing software or hardware. Therefore, what is needed is a system and method for allowing a microphone array to avoid the use of expensive matched electronic components by allowing for the use of relatively less expensive non-matched electronic components. Further, rather than requiring software to be specifically pre-tailored to the particular operational parameters of each microphone/preamplifier combination within the array, the microphone array should instead be operable with software that automatically configures itself to the operational parameters of the microphone array. Consequently, such a system and method should automatically determine and compensate for variations in the gain and frequency response of each microphone/preamplifier combination within the array to allow for automatic configuration and optimization of audio processing software associated with the microphone array. | <SOH> SUMMARY <EOH>As is well known to those skilled in the art, conventional microphone arrays typically include an arrangement of one or more microphones in some predetermined layout. In general, each microphone in these arrays typically includes an associated preamplifier for providing amplification or gain for analog audio signals captured by each microphone. Further, each of the input channels (i.e., each microphone/preamplifier combination) of such microphone arrays are typically matched so that that the sensitivity and frequency responses of those input channels are as close as possible to one another for any particular audio input. However, providing for matched components in a microphone array tends to increase both cost and test time when manufacturing such arrays. Therefore, in contrast to conventional microphone arrays, an analog preamplifier measurement system for a microphone array, as described herein, operates to solve the problems identified above by providing a modified microphone array with an integral “self-calibration system.” In general, this integral self-calibration system automatically determines frequency-domain responses of each preamplifier in the microphone array, and computes frequency-domain compensation gains, so that digital signal processing applications can use those compensation gains for matching the output of each preamplifier. As a result, there is no need to predetermine exact operational characteristics of each channel of the microphone array, or to use expensive matched electronic components. Further, as is well known to those skilled in the art, individual microphone operational characteristics, as well as the characteristics of most other electrical components, tend to change both over time and as a function of local temperature. Consequently, use of the integral self-calibration system provides current operational parameters of the microphones and associated preamplifiers within the microphone array which better reflect actual component parameters than factory measured values which are typically coded into conventional microphone arrays or audio processing software. In operation, the integral self-calibration system injects excitation pulses of a known magnitude and phase to all preamplifier inputs within the microphone array. Note that the duration of the pulse should be larger than the preamplifier step response so as to avoid or minimize any effects resulting from transient responses. The resulting analog waveform from each preamplifier output is then measured. A frequency analysis, such as, for example, a Fourier or Fast Fourier Transform (FFT), or other conventional frequency analysis, of each of the resulting waveforms is then performed. The results of this frequency analysis are then used to compute frequency-domain compensation gains for each preamplifier for matching or balancing the responses of all of the preamplifiers with each other. In one embodiment, the integral self-calibration system is included in a “self-descriptive microphone array,” as described in a copending patent application entitled “SELF-DESCRIPTIVE MICROPHONE ARRAY,” having a filing date of TBD, and assigned Serial Number TBD, the subject matter of which is incorporated herein by this reference. In this embodiment, the integral self-calibration system operates automatically either upon connection of the self-descriptive microphone array to the external computing device, upon regular or user-specified intervals, or upon command. In this embodiment the injection of pulses, readings of the preamplifier outputs, and computation of the frequency analysis, are all performed by driver software residing in the external computing device connected to the microphone array. Once computed, these frequency-domain compensation gains can then be applied to the output of each corresponding preamplifier when processing actual audio inputs of the microphones associated with each preamplifier. This serves to make the output from each of the preamplifiers consistent, given the same or similar input to any of the microphones in the array. Consequently, using these computed frequency-domain compensation gains, audio processing software such as, for example, software for performing sound source localization, beam forming, acoustic echo cancellation, noise suppression, etc., can easily compensate for phase response mismatches across all preamplifiers. Without this compensation, any phase response mismatches would reduce the performance of the audio processing software. Therefore, as a result of computing and providing these frequency-domain compensation gains for each preamplifier, there is no need to use expensive matched electrical components. Consequently, one advantage offered by the integral self-calibration system described herein is that microphone arrays using this integral self-calibration system may be inexpensively produced by using relatively inexpensive non-matched electrical components including, for example, transistors, capacitors, resistors, op amps, etc. As noted above, the integral self-calibration system operates by first injecting a single pulse of a known magnitude and phase to each preamplifier. Then, as described above, the output of each preamplifier is then measured and used to compute frequency-domain compensation gains for each preamplifier. However, in another embodiment, multiple pulses of a known magnitude and phase are instead injected to each preamplifier. Then, for each preamplifier, the output resulting from each of the injected pulses is averaged. The averaged output of each preamplifier is then used to compute frequency-domain compensation gains for each preamplifier, as described above for the case of the single injected pulse. In yet another embodiment, circuitry is included in the microphone array for automatically switching off the input from each microphone prior to inputting each the aforementioned pulse or pulses to each corresponding preamplifier. However, it has been observed that in the embodiment wherein multiple pulses are used along with an average of the preamplifier output, any noise resulting from allowing the microphones to remain active or live during pulse injection has a negligible effect on the computed frequency-domain compensation gains for each preamplifier, especially as the number of pulses increases. As noted above, in one embodiment, the integral self-calibration system is included in a self-descriptive microphone array which makes use of external computing power for performing computations. In this embodiment, the frequency analysis for computing the frequency-domain compensation gains for each preamplifier is performed by an external computing device, such as a PC-type computer, or other computing device, coupled to the microphone array. One advantage of this embodiment is that because the microphone array makes use of external processing power, there is no need to include relatively expensive onboard signal processing software or hardware capabilities within the array itself. Consequently, the self-descriptive microphone array is relatively inexpensive to manufacture in comparison to conventional microphone array devices that include onboard audio processing capabilities. Note that the connection (a “microphone array interface”) between the self-descriptive microphone array and the external computing device is accomplished using any of a variety of conventional wired or wireless computer interfaces, including, for example, serial, parallel, IEEE 1394, USB, IEEE 802.11, Bluetooth™, etc. In another embodiment, as described in the aforementioned copending patent application entitled “SELF-DESCRIPTIVE MICROPHONE ARRAY,” the microphone array further includes a “microphone array memory” that is integral to the microphone array. This microphone array memory includes any type of non-volatile memory, such as, for example a ROM, PROM, EPROM, EEPROM, or other conventional non-volatile memory type or device, which contains a microphone array device description. This device description includes parametric information, including the computed frequency-domain compensation gains for each preamplifier, which defines operational characteristics and configuration of the microphone array. In operation, the device description of the microphone array is automatically reported to the external computing device via the microphone array interface to the external computing device. In this embodiment, once the microphone array device description is provided to the external computing device, the external computing device then uses the device description to automatically configure audio processing software residing within the external computing device for processing one or more audio signals captured by the microphone array. Specifically, software applications residing within the external computing device, such as dynamic link libraries (DLLs) or other software drivers or programs, interpret physical parameters of the microphone array, including the frequency-domain compensation gains, that are provided by the microphone array device description. These software applications then communicate the physical parameter data of the microphone array to signal processing software residing within the external computing device. This allows the signal processing software to automatically adjust its operational parameters to the characteristics of the attached microphone array to perform automatically optimized audio processing computations. As noted above, preamplifiers are associated with each microphone in the microphone array. Further, to allow for multiple simultaneous channels of audio to be captured by the microphone array, one or analog-to-digital (A/D) converters are also associated with each microphone. Audio signals captured by the microphone array are then pre-amplified (i.e., gain) and converted to a digital signal via the A/D converters and provided, via the aforementioned wired or wireless computer interface, to the audio processing software residing within the external computing device for further processing, as desired. The maximum number of digital audio channels that can then be transmitted via the computer interface is then only limited by the maximum bandwidth of that computer interface in combination with the digital sampling rate of each channel of the microphone array. In another embodiment, in addition to including one or more microphones, the microphone array also includes one or more loudspeakers for reproducing one or more audio signals. For example, many microphone arrays, such as those arrays used for audio conferencing, frequently include both microphones and speakers. The microphones capture sound, and the speakers play back sound. Generally, conventional audio conferencing-type microphone arrays also include relatively expensive onboard acoustic echo cancellation capabilities so that local audio signals are not endlessly echoed during an audio conference. However, in the context of the aforementioned self-descriptive microphone array, audio processing, such as acoustic echo cancellation, is performed via the audio processing software residing within the external computing device. In this embodiment, audio to be played back via the self-descriptive microphone array is then simply transmitted from the external computing device to the array via the aforementioned wired or wireless computer interface. In this embodiment, as with the parametric information defining the microphones and preamplifiers within the microphone array, parametric information defining the speakers within the microphone array is also stored within the microphone array memory. Configuration of the microphone array is then reported, as noted above, to allow for automatic configuration of the audio processing software residing within the external computing device to which the microphone array is connected. In view of the above summary, it is clear that the integral self-calibration system for the microphone array provides a unique system and method for automatically determining frequency-domain compensation gains for each audio input channel within the array. In addition to the just described benefits, other advantages of the self-calibration system for the microphone array will become apparent from the detailed description which follows hereinafter when taken in conjunction with the accompanying drawing figures. | 20040204 | 20080923 | 20050804 | 68049.0 | 0 | LEE, PING | ANALOG PREAMPLIFIER MEASUREMENT FOR A MICROPHONE ARRAY | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,772,762 | ACCEPTED | Thermal management systems and methods | A thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein, a first coolant loop thermally coupled to an electrochemical storage device located within the first coolant loop and to the heat exchanger, and a second coolant loop thermally coupled to the heat exchanger. The first and second coolant loops are configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided. | 1. A thermal management system for a vehicle, comprising: a heat exchanger having a thermal energy storage material provided therein; a first coolant loop thermally coupled to an electro-chemical storage device located within the first coolant loop and to the heat exchanger; a second coolant loop thermally coupled to the heat exchanger, the first and second loops configured to carry distinct thermal energy transfer media; and an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electro-chemical storage device. 2. The system of claim 1, wherein the heat generated by the internal combustion engine is provided to the heat exchanger to regenerate the thermal energy storage material, and the electro-chemical storage device comprises one or more batteries, capacitors, fuel cells, or combinations thereof. 3. The system of claim 2, wherein regenerating the thermal energy storage material includes converting the thermal energy storage material from a solid state to a liquid state. 4. The system of claim 1, wherein the first coolant loop comprises a coolant mixture that is different from the thermal energy transfer medium flowing through the second loop. 5. The system of claim 4, wherein the thermal energy transfer medium flowing through the second loop comprises a coolant used in association with the internal combustion engine. 6. The system of claim 5, wherein the interface comprises one or more fluid supply paths in fluid communication with the second coolant loop. 7. The system of claim 6, wherein the heat generated by the internal combustion engine is provided to the heat exchanger via at least one of the fluid supply paths and the second coolant loop, the fluid supply paths being thermally coupled to a radiator core of the vehicle, and upon providing the heat to the heat exchanger, at least one of a sensible heat or a latent heat of fusion of the thermal energy storage material is increased from a thermal state to a higher different thermal state. 8. The system of claim 6, wherein the heat generated by the internal combustion engine is provided to the heat exchanger via at least one of the fluid supply paths and the second coolant loop, the fluid supply paths being adapted to be thermally coupled to a radiator core of the vehicle, and upon providing the heat to the heat exchanger, a sensible heat as well as a latent heat of fusion of the thermal energy storage material are increased from a thermal state to a higher different thermal state. 9. The system of claim 1, wherein the heat generated by the internal combustion engine is selectively delivered to heat a passenger cabin of the vehicle via the second coolant loop, or delivered to the electro-chemical storage device via the first coolant loop to increase a temperature of the electrochemical storage device. 10. The system of claim 1, wherein the thermal energy storage material comprises a phase change material configured to change from a solid state to a liquid state and vice-versa during select conditions. 11. The system of claim 1, further comprising: a second heat exchanger provided in the first coolant loop, the thermal energy transfer medium flowing in the first coolant loop is selectively flowed through the second heat exchanger to reduce a temperature TBatt to within a predetermined temperature range; a bypass fluid path configured to deliver the thermal energy transfer medium circulating in the first coolant loop, bypassing the heat exchanger, to the electrochemical storage device; and first and second pumps to enable circulation of the thermal energy transfer media provided in the respective first and second coolant loops. 12. The system of claim 11, further comprising a plurality of three-way valves configured to selectively permit the thermal energy transfer medium flowing in the first coolant loop to flow through the heat exchanger or the bypass fluid path. 13. The system of claim 11, wherein the thermal energy transfer medium flowing in the first coolant loop is flowed via the bypass fluid path if a temperature TBatt of the electro-chemical storage device is above a predetermined maximum threshold temperature Tmax. 14. The system of claim 11, wherein the thermal energy transfer medium flowing in the first coolant loop is enabled to flow through the heat exchanger if a temperature TBatt of the electro-chemical storage device is below a predetermined minimum threshold temperature Tmin. 15. The system of claim 11, wherein the second heat exchanger comprises air-to-glycol mixture heat exchanger. 16. The system of claim 1, wherein the heat exchanger comprises a liquid-to-liquid heat exchanger. 17. The system of claim 16, wherein the heat exchanger comprises: heat exchange tubing configured to exchange heat between the thermal energy storage material and the respective thermal energy transfer media circulating in the first and second coolant loops; and heat exchange fins configured to enhance the heat exchange, wherein the thermal energy storage material is encapsulated in one or more sections of flexible tubing comprised in the heat exchanger, wherein encapsulation in the one or more sections of the flexible tubing reduces a ratio of encapsulant volume relative to volume of the thermal energy storage material. 18. The system of claim 16, wherein the heat exchanger is configured to control heat supplied to components of the vehicle during select phases of vehicular operation including cold-start conditions, normal operating conditions, and hot-operating conditions. 19. The system of claim 1, wherein the heat generated by the internal combustion engine is stored in the thermal energy storage material for use during cold-start conditions of the vehicle to increase a temperature TBatt of the electrochemical storage device. 20. The system of claim 1, wherein the heat exchanger is configured to preheat the electro-chemical storage device and a passenger cabin of the vehicle to enhance performance of the electro-chemical storage device and enhance cabin comfort of the passenger cabin. 21. The system of claim 1, wherein the thermal energy storage material provided within the heat exchanger is encapsulated in spheres in a baffled framework within the heat exchanger. 22. A thermal management system for a hybrid electric vehicle, comprising: a first fluid loop having a first coolant mixture flowing therein; a battery module located in the first fluid loop; a second fluid loop having a second coolant mixture flowing therein, the second coolant mixture being distinct from the first coolant mixture; a heat exchanger having a phase change material provided therein; the first and second fluid loops being configured to be in thermal communication with the heat exchanger, the heat exchanger being configured to flow only the first coolant mixture within the heat exchanger; and a thermal interface configured to transfer heat produced by an internal combustion engine of the vehicle to the heat exchanger, the heat exchanger being configured to store the heat generated by the internal combustion engine and selectively provide the stored heat to control thermal characteristics of various components of the vehicle including the battery module. 23. The system of claim 22, further comprising: a second heat exchanger thermally coupled to the first fluid loop; and a bypass fluid path configured to deliver the first coolant mixture to the second heat exchanger bypassing the heat exchanger in order to dissipate heat carried by the first coolant mixture and to reduce a temperature TBatt of the battery module below a maximum desirable temperature Tmax. 24. The system of claim 23, wherein the heat generated by the internal combustion engine is transferred to the heat exchanger via the second fluid loop and stored therein, and the heat stored in the heat exchanger is selectively delivered to the battery module via the first fluid loop. 25. The system of claim 22, wherein the heat generated by the internal combustion engine is transferred to the heat exchanger to regenerate the phase change material. 26. The system of claim 22, wherein the heat generated by the internal combustion engine is transferred to the heat exchanger via a fluid path configured to be thermally coupled to the second fluid loop and a radiator core of the vehicle, and further wherein after receiving the heat generated by the internal combustion engine, at least one of a sensible heat or a latent heat of fusion of the phase change material is increased from a thermal state to a higher different thermal state. 27. The system of claim 22, wherein the heat generated by the internal combustion engine is transferred to the heat exchanger via a fluid path configured to be thermally coupled to the second fluid loop and a radiator core of the vehicle, and further wherein after receiving the heat generated by the internal combustion engine, a sensible heat as well as a latent heat of fusion of the phase change material are increased from a thermal state to a higher different thermal state. 28. The system of claim 22, wherein the heat generated by the internal combustion engine is selectively delivered to heat a passenger cabin of the vehicle, the passenger cabin being thermally coupled to the heat exchanger via the second fluid loop. 29. A thermal management system for a vehicle, comprising: a heat exchanger means having a means for storing thermal energy; a first coolant loop thermally coupled to an electrical energy storage means located within the first coolant loop; a second coolant loop, the first and second coolant loops being thermally coupled to the heat exchanger means and configured to carry a thermal energy transfer medium; and an interface means for enabling transfer of heat generated by an internal combustion engine to the heat exchanger means in order to selectively deliver the heat to the electro-chemical storage means. 30. The system of claim 29, further comprising: a second heat exchanger means provided in the first coolant loop; and a bypass fluid path for delivering a first coolant mixture, provided in the first coolant loop, to the second heat exchanger means bypassing the heat exchanger means in order to dissipate heat carried by the first coolant mixture to reduce a temperature TBatt of the electrical energy storage means to within a predetermined maximum temperature Tmax. 31. The system of claim 29, wherein the interface means comprising a fluid path that is thermally coupled to the second fluid loop, and a radiator core of the vehicle is configured to be thermally coupled to the fluid path to transfer the heat generated by the internal combustion engine to the heat exchanger means, and at least one of a sensible heat or a latent heat of fusion of the phase change material is increased from a thermal state to a higher different thermal state after receiving the heat generated by the internal combustion engine. 32. The system of claim 29, wherein the interface means comprising a fluid path that is thermally coupled to the second fluid loop, and a radiator core of the vehicle is configured to be thermally coupled to the fluid path to transfer the heat generated by the internal combustion engine to the heat exchanger means, further wherein a sensible heat and a latent heat of fusion of the phase change material are increased from a thermal state to a higher different thermal state after receiving the heat generated by the internal combustion engine. 33. The system of claim 29, wherein the heat generated by the internal combustion engine is selectively delivered to heat a passenger cabin of the vehicle, wherein the passenger cabin is thermally coupled to the heat exchanger means via the second coolant loop. 34. A thermal management method for a vehicle, comprising: providing a heat exchanger having a thermal energy storage material disposed therein; providing first and second coolant loops configured to circulate distinct coolant mixtures through the respective first and second coolant loops; thermally coupling the first coolant loop to a battery module located within the first coolant loop; thermally coupling the second coolant loop to the heat exchanger; providing an interface in close proximity to the second coolant loop, wherein the interface is configured to transfer heat generated by an internal combustion engine of the vehicle to the heat exchanger, via the second coolant loop, for storage within the thermal energy storage material; and selectively performing one or more of preheating the battery module, heating a passenger cabin of the vehicle, increasing sensible heat or latent heat of fusion of the material from a first thermal state to a higher second thermal state using the heat stored within the thermal energy storage material. 35. The method of claim 34, further comprising: thermally coupling a second heat exchanger to the first coolant loop to cool the battery module; and providing a bypass fluid path to deliver the first coolant mixture to the second heat exchanger bypassing the heat exchanger in order to cool the battery module by reducing a temperature TBatt of the battery module below a maximum desirable temperature Tmax. 36. The method of claim 35, further comprising: transferring the heat generated by the internal combustion engine to the heat exchanger via the second fluid loop for storage in the heat exchanger; and selectively delivering the heat stored in the heat exchanger to the battery module via the first fluid loop to increase the temperature TBatt of the battery module. 37. The method of claim 36, further comprising: transferring the heat generated by the internal combustion engine to the heat exchanger; and after receiving the heat at the heat exchanger, one or more of sensible heat or latent heat of fusion of the phase change material is increased from a first thermal state to a higher different thermal state. 38. The method of claim 37, further comprising selectively delivering the heat generated by the internal combustion engine to heat a passenger cabin of the vehicle. | GOVERNMENT RIGHTS This invention was made with Government support under Contract No. DE-AC07-99ID13727 awarded by the U.S. Department of Energy. The Government has certain rights in the invention. TECHNICAL FIELD Aspects of the invention generally relate to thermal management systems (TMSs) and methods. BACKGROUND OF THE INVENTION Hybrid electric vehicles (HEVs) and electric vehicles (EVs) provide improved fuel economy and reduced air emissions over conventional vehicles. The performance of HEVs and EVs depend on energy storage systems such as batteries. Battery performance influences, for example, acceleration, fuel economy, and charge acceptance during recovery from regenerative braking. As the cost of the batteries, durability, and life-cycle affect the cost and reliability of a vehicle using the batteries for vehicular operation, parameters that affect the efficiency of the batteries may have to be optimized to achieve optimized vehicular performance. It is known that temperature has an influence over battery performance. Battery modules carrying batteries are preferred to operate within an optimum temperature range that is suitable for a particular electrochemical pair. For example, the desired operating temperature for a lead acid battery is 25° C. to 45° C. Battery modules may also have to be operated at uniform temperatures as uneven temperature distribution may result in varied charge-discharge behavior. Such varied charge-discharge behavior may lead to electrically unbalanced modules and reduced battery performance. HEVs may be less reliable in northern latitudes due to cold temperature constraints imposed on the batteries carried by the HEVs. Lithium ion batteries have been a candidate for use in HEVs, and such batteries have optimum performance when operating from 0-40° C. Below 0° C., power output of the batteries diminishes and the effect of temperature becomes more severe as the level of discharge increases. Conversely, as temperatures exceed above 40° C., detrimental cathode corrosion and other irreversible reactions may occur resulting in shortened battery life. Accordingly, a battery thermal management system (TMS) is needed to achieve desired and reliable performance in varied climatic conditions while minimizing temperature excursions outside a desired temperature range. SUMMARY OF THE INVENTION Aspects of the invention also relate to a comprehensive thermal management system for hybrid electric vehicles which include both an internal combustion engine and battery based locomotion (example, lithium-ion, or nickel metal hydride). Aspects of the invention also disclose a thermal management system configured to provide a mechanism to pre-warm a vehicle's battery module, having a plurality of individual cells, in cold conditions, provide auxiliary warmth to the module as needed, and remove heat from it as the batteries heat up due to normal ohmic discharge and recharge. In some embodiments, a thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein. The thermal management system includes a first coolant loop thermally coupled to an electro-chemical storage device located within the first coolant loop and to the heat exchanger, a second coolant loop, thermally coupled to the heat exchanger, the first and second loops configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided. In other embodiments, a thermal management system for a hybrid electric vehicle includes a heat exchanger having a phase change material provided therein, a first fluid loop having a first coolant mixture flowing therein, and a second fluid loop having a second coolant mixture flowing therein, the second coolant mixture being distinct from the first coolant mixture. The first and second fluid loops are configured to be in thermal communication with the heat exchanger, the heat exchanger being configured to flow only the first coolant mixture within the heat exchanger. The thermal management system also includes a thermal interface configured to transfer heat produced by an internal combustion engine of the vehicle to the heat exchanger, the heat exchanger being configured to store the heat generated by the internal combustion engine and selectively provide the stored heat to control thermal characteristics of various components of the vehicle including the battery module. In yet other embodiments, a thermal management method for a vehicle includes providing a heat exchanger having a thermal energy storage material disposed therein, providing first and second coolant loops to circulate distinct coolant mixtures through the respective first and second coolant loops, thermally coupling the first coolant loop to a battery module located within the first coolant loop, thermally coupling the second coolant loop to the heat exchanger, and providing an interface in close proximity to the second coolant loop. The interface is configured to transfer heat generated by an internal combustion engine of the vehicle to the heat exchanger, via the second coolant loop, for storage within the thermal energy storage material. The method also includes selectively performing one or more of preheating the battery module, heating a passenger cabin of the vehicle, increasing sensible heat or latent heat of fusion of the material from a first thermal state to a higher second thermal state using the heat stored within the thermal energy storage material. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are described below with reference to the following accompanying drawings. FIG. 1 shows a schematic of a vehicle in accordance with various embodiments of the invention. FIG. 2 is a schematic of a thermal management system as shown in FIG. 1 in accordance with various embodiments of the invention. FIG. 3A is a schematic of a heat exchanger shown in FIG. 2 in accordance with some embodiments of the invention. FIG. 3B is a schematic of a heat exchanger shown in FIG. 2 in accordance with other embodiments of the invention. FIG. 4 is a graph illustrating a thermal cycle for a phase change material that is stored in a heat exchanger in accordance with various embodiments of the invention. FIG. 5 is a graph illustrating temperature history of a phase change material and battery cooling fluid in accordance with various embodiments of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8). The following terminology as described below is used to define terms that are used in this application. The following operational parameters and control strategy may be used in various embodiments: Measured Temperatures. TBatt: average or representative temperature within battery module of battery 110. TCab: representative temperature of coolant within the internal combustion engine cabin (ICE cabin) heater core 118. TPCM: average or representative temperature within phase change material (PCM) module 214, 218 of heat exchanger (HX) 116. TRad: representative temperature of the internal combustion engine radiator coolant/fluid in loop 104. Set-Point Temperatures. Tmin: minimum desirable battery temperature. Tmax: maximum desirable battery temperature. T*: minimum desirable temperature of cabin heater core. T**: phase change material melting temperature plus a margin of 5 to 10° C. Control Strategy in Accordance with Various Embodiments of the Invention. V1—full open to heat exchanger 106: TBatt>Tmax; otherwise closed to heat exchanger 106. V2—full open to Bypass: TBatt>Tmax; otherwise closed to Bypass. V3—full open to cabin core: [(TBatt>Tmin) and (TBatt<Tmax)] and (TCab<T*) and (TRad<T*) and (TPCM>TCab); otherwise open to internal combustion engine radiator 120. FAN 108—On at TBatt>Tmax; otherwise Off. P1—On: (TBatt<Tmin) or (TBatt>Tmax). Off: (TBatt>Tmin) and (TBatt<Tmax). P2—On: (a) using internal combustion engine coolant/fluid in loop 104 to help warm batteries 110 (TBatt<Tmin) and (TPCM<Tmin) and (TRad>TPCM). (b) sending excess heat to cabin heater core 118 [(TBatt>Tmin) and (TBatt<Tmax)] and (TPCM>TCab) and (TCab<T*) and (TRad<T*). (c) remelting phase change material (214, 218) and increasing sensible heat of the phase change material (214, 218) {[(TBatt>Tmin) and (TBatt<Tmax)] or (TBatt>Tmax)} and (TPCM<T**) and (TRad>T**). Otherwise Off. FIG. 1 shows a vehicle 10 embodying the invention. The vehicle 10 includes a thermal management system 100 and an on-board processor (and memory) or processor 101 in communication with the thermal management system 100. The thermal management system 100 is configured to manage heat (e.g., thermal management of electro-chemical energy storage device 110 (e.g., battery module or battery)) (FIG. 2) of vehicle 10 during various phases of vehicular operation, such as for example, cold-start conditions, normal conditions, and hot environmental conditions. The device 110 is generally referred to herein as battery 110. The device 110 may also be provided as an electro-chemical energy storage device module. Further details of the thermal management system 100 are set forth and described below with reference to FIG. 2. Exemplary embodiments of battery types include lithium-ion, nickel-metal-hydride, and lead-acid. The electro-chemical energy storage device may comprise one or more batteries, capacitors, fuel cells, or combinations thereof. The on-board processor 101 is configured to control various operations of the vehicle 10 including controlling of various sensors (not shown) of the vehicle 10. The on-board processor 101 may also be configured to control heat (e.g., heat supplied/discharged to/from the battery 110 (FIG. 2)) together with the thermal management system 100, during various phases of vehicular operation as noted above. In some embodiments, the processor 101 may comprise circuitry configured to execute provided programming. For example, the processor 101 may be implemented as a microprocessor or other structure configured to execute executable instructions of programming including, for example, software or firmware instructions. Other exemplary embodiments of the processor 101 include hardware logic, PGA, FPGA, ASIC, or other structures. These examples of the processor 101 are illustrative. As such, other configurations are possible for implementing operations performed by the processor 101. In some embodiments, a separate processor is used in connection with the thermal management system 100 than the on-board processor. In other embodiments, the processor 101 may be programmed with predetermined temperature value(s) in a desired temperature range (e.g., of battery 110 (FIG. 2)) corresponding to various phases of vehicular operation as noted above. The processor 101 is configured to compare the stored value(s) with measured temperature value(s) and provide instructions, based on the comparison, to the thermal management system 100 configured to manage heat of the battery 110 during various phases of operation of the vehicle 10. Further details of such heat management are set forth below with reference to FIG. 2. FIG. 2 is a schematic of the thermal management system 100 as shown in FIG. 1. The thermal management system 100 includes heat exchanging fluid loops 102, 104, heat exchangers 106, 116, a fan 108 corresponding to the heat exchanger 106, a battery 110 (e.g., a lithium-ion battery or battery bank), a coolant expansion tank (ET) 112, pumps P1 and P2, a bypass loop 114, an internal combustion engine cabin heater core 118 (referred to herein as internal combustion engine cabin), an internal combustion engine radiator 120, and an interface 122. The thermal management system 100 also includes a plurality of valves V1-V7 (e.g., control valves V1-V3 and check valves V4-V7). The loop 102 (shown to the left of heat exchanger 116) is configured as a battery side coolant loop for flowing or recirculating coolant or a fluid or a thermal energy transfer medium from the expansion tank 112 to add or remove heat from the battery 110 of the vehicle 10. The loop 102 is alternatively referred to herein as “battery fluid loop”. In some embodiments, coolant flowing in the loop 102 is circulated via the loop 114 bypassing the heat exchanger 116. In other embodiments, coolant flowing in the loop 102 flows through the heat exchanger 116 without flowing via the loop 114. The control valve V2 is appropriately controlled (e.g., opened or closed) to achieve such functionality. The loop 104 (shown to the right side of heat exchanger 116) is configured as an internal combustion engine side coolant loop 104 for flowing or recirculating heat exchanging fluid or a coolant via the heat exchanger 116, the internal combustion engine cabin 118 in some embodiments. In other embodiments, the loop 104 is configured for flowing or recirculating the heat exchanging fluid via the heat exchanger 116 and the internal combustion engine radiator 120 bypassing the internal combustion engine cabin 118. The heat exchanging fluid flowing through the loop 104 may be a coolant used for cooling the internal combustion engine (not shown), whereas the fluid flowing through the loop 102 can be of a different composition, compared to the fluid in the loop 104, to achieve unique heat transfer performance for the loop 102. The heat exchanger 106 together with the fan 108 is configured to control temperature of the battery 110 to be within a predetermined optimal range. In one embodiment, fluid in the loop 102 is recirculated through the heat exchanger 106 in order to control excessive temperatures of the fluid in the loop 102, the fluid being circulated through the battery 110. Battery 110 includes energy storage batteries configured to provide energy for operation of the vehicle 10. The battery 110 may be configured to have the loop 102 passing through the battery 110 to control thermal characteristics of the battery 110. It will be appreciated that the battery 110 may be configured to include a module to house a fluid (e.g., coolant) and such module may be configured to be coupled to the loop 102. The expansion tank 112 may be configured as a coolant expansion tank for housing the fluid that is circulated in the loop 102. The loop 114 is configured as a bypass loop for the fluid recirculating in the loop 102. Fluid in the loop 102 may be flowed through the loop 114 bypassing the heat exchanger 116 in some embodiments. The heat exchanger 116 is configured as a well-insulated heat exchanger vessel to store a fixed volume of phase change material (reference numerals 214, 218 of FIGS. 3A, 3B) and a small volume of fluid (e.g., coolant) that is pre-warmed from a prior operation of the vehicle 10. The phase change material of the heat exchanger 116 provides latent and sensible heat that may be transferred to the fluid flowing through the heat exchanger 116 in some embodiments. The heat exchanger 116 is further configured to facilitate heat transfer to control thermal characteristics of the battery 110 as well as controlling a temperature of a passenger cabin of the vehicle 10 by flowing the fluid in the loop 104 via the internal combustion engine cabin 118 in some embodiments. Further design details of the heat exchanger 116 are set forth below with reference to FIGS. 3A-3B. The internal combustion engine cabin heater core 118 is configured to provide heat to the passenger cabin of the vehicle 10 to maintain a temperature of the passenger cabin within a predetermined temperature range. The internal combustion engine radiator 120 is configured to control the temperature of the internal combustion engine. The interface 122 is configured as an interface between the thermal management system 100 and the internal combustion engine (not shown) of the vehicle 10. For example, the interface 122 is designed to transport heat transfer fluids containing waste heat generated by the internal combustion engine to control the temperature of the battery 110 provided in the loop 102. Waste heat generated by the internal combustion engine may be transferred to the heat exchanger 116 via the loop 104, and the heat transferred to the heat exchanger 116 is stored in the phase change material resident in the heat exchanger 116. Such heat stored in the phase change material resident in the heat exchanger 116 is then provided to the battery 110 via the loop 102 to increase the temperature TBatt of the battery 110. Phase change materials are desirable in a thermal management system due to exothermic heat of phase change, or latent heat, that is released as the phase change material undergoes a transition from one state (e.g., liquid) to another state (e.g., solid). Phase change materials are also desirable as a thermal cycle of most phase change materials is reversible, thus enabling the phase change material to be regenerated from a solid state to a liquid state by the addition of external heat. With regeneration, a phase change material may be used as a reliable heat source for multiple times. The combination of the phase change material latent heat and sensible heat (e.g., heat above that which is required to achieve phase change material melting) increases the overall heating value per mass. The phase change materials used in various embodiments of the invention are desired to have the following characteristics: (i) Undergo fusion/melting within the desired temperature range (e.g., melting below 90 degrees C. and fusion (crystallization) at no lower than −20 degrees C.); (ii) limited or controlled supercooling so that nucleation would occur on demand; (iii) high heat of fusion; (iv) rapid crystallization so that heat is generated at a useable rate; (v) ability to undergo numerous cycles without degradation or diminished performance; (vi) be inexpensive, readily available, non-toxic, non-flammable, non-reactive, and non-corrosive. The inventors have determined the materials as listed in Table I to be viable phase change material candidates for various embodiments of the invention. TABLE I Melting Autonucleation Phase Change Material Temperature, ° C. Temperature, ° C. Sodium acetate 3.6-hydrate 58 −10 to −18 Sodium acetate 4.0-hydrate 58 −14 to −18 Sodium acetate/magnesium 58 −17 to −21 acetate (1 wt % Mg) 3.5-hydrate Sodium acetate/magnesium 58 −14 to −20 acetate (5 wt % Mg) 3.5-hydrate Ethylene carbonate 36 8.2 Ethylene carbonate/propylene 36 −0.5 carbonate (3.7 mole % PC) Ethylene carbonate/propylene 36 3.4 carbonate (5.6 mole % PC) Ethylene carbonate/propylene 36 12.8 carbonate (6.7 mole % PC) Calcium chloride 6.0-hydrate 30 2 Sodium hydrogen phosphate 12- 35 20 to 25 (ambient) hydrate In accordance with various embodiments, the thermal management system 100 is configured to maintain temperatures of the battery 110 within an optimal range while providing heat for cabin comforts under cold environmental conditions. For example, an optimal range may be chosen to be between 0-40 degrees Centigrade. Such a temperature range was found to be favorable for Lithium-ion batteries. During the operation of the thermal management system 100, fluids within the loops 102, 104 are circulated to add or remove heat according to a predetermined thermal protocol (e.g., predetermined values or established conditions) of the vehicle 10. Valves V1-V3 (e.g., control valves) and valves V4-V7 (e.g., one-way check valves) are configured to ensure that respective fluids in the loops 102, 104 flow through desired fluid paths. Valves V1 and V2 are specified as thermostatic, wherein their actuation is driven by the temperature of the fluid flowing through each. Valve V3 is electronically actuated based on control logic resident within the processor 101 and relevant temperature inputs described herein. The operation of the thermal management system 100 may be described by the following exemplary modes of operation: (1) cold-start conditions, (2) normal conditions, (3) hot mode. Each mode of operation is controlled by defined control parameters as described below. Under cold-start conditions, the temperature (TBatt) of the battery 110 may not be within a predetermined temperature range. In some embodiments, if TBatt is beneath the predetermined temperature range, then the pump P1 is operated (e.g., turned ON) and valve V2 is controlled to circulate the fluid (e.g., coolant) from the battery 110 to the heat exchanger 116, whereupon sensible heat (e.g., heat stored in the fluid present in the heat exchanger 116) is transferred to the fluid circulating in the loop 102 and flowing through the heat exchanger 116. For example, after pump P1 is operated, fluid from the battery 110 and flowing in the loop 102 flows to the heat exchanger 116 and displaces the pre-warmed fluid therein. The pre-warmed fluid is circulated to the battery 110 by appropriately operating the valves V4 and V1. In other embodiments, latent heat from the phase change material resident in the heat exchanger 116 can also be transferred if the fluid circulating in the loop 102 and in contact with the phase change material (reference numerals 214, 218 of FIGS. 3A, 3B) in the heat exchanger 116 is sufficiently cold to initiate autonucleation of the phase change material 214, 218. However, if the heat exchanger 116 is unable to provide sufficient heat (e.g., to the fluid circulating in the loop 102 through the heat exchanger 116) to increase TBatt due to the low temperature TPCM of the phase change material (214, 218), then pump P2 is operated (e.g., turned ON) to circulate fluid (e.g., internal combustion engine coolant) from the internal combustion engine (not shown) to the heat exchanger 116 via the interface 122 (e.g., internal combustion engine-heat exchanger interface). In this case, waste heat generated by the internal combustion engine is transferred to the heat exchanger 116. For example, if the fluid in the internal combustion engine is warmer than TPCM and {(TBatt<Tmin) and (TPCM<Tmin)}, then the pump P2 is turned ON to circulate warm fluid from the internal combustion engine to the heat exchanger 116 via the interface 122. After the pump P2 is turned ON, the pump P1 is operated to circulate fluid, present in the loop 102, through the heat exchanger 116 until the temperature of the battery 110 is restored to be within the predetermined temperature range. Operation of thermal management system 100 under normal conditions is now described. Normal conditions described herein are defined by the temperature TBatt of the battery 110 being within the predetermined temperature range. Under the normal conditions, the pump P1 remains OFF. However, the pump P2 may recirculate fluid in the loop 104 to the heat exchanger 116 in order to remove excess heat from the heat exchanger 116 if the temperature (TPCM) of the phase change material (214, 216) resident in the heat exchanger 116 is greater than the temperature of the fluid circulating in the loop 104. After the excess heat from the phase change material (214, 216) is transferred to the fluid in the loop 104, valves V5 and V3 are appropriately controlled to route the fluid from the heat exchanger 116, with the received excess heat, to the internal combustion engine cabin 118 if the temperature of the internal combustion engine cabin 118 is less than a predetermined temperature range. However, if the temperature of the internal combustion engine cabin 118 is within a predetermined temperature range, then valve V3 is controlled to route the fluid from the heat exchanger 116, with the received excess heat, to the internal combustion engine radiator 120 and bypassing the internal combustion engine cabin 118. Circulating the fluid that is received from the heat exchanger 116 to flow through the internal combustion engine radiator 120 further increases the temperature of the fluid that is circulated in the loop 104. The fluid flowing from the internal combustion engine radiator and circulating in the loop 104 is flowed through the heat exchanger 116, by controlling the valve V7 and the pump P2, to remelt the phase change material (214, 218) resident in the heat exchanger 116, thereby increasing the thermal energy of the phase change material. This process ensures that the phase change material is remelted at the first opportunity, thereby reactivating the phase change material and keeping it ready for subsequent use under cold-start conditions as explained above. It will be appreciated that normal conditions may occur under cold ambient conditions since the battery 110 and the heat exchanger 116 are sufficiently insulated to render the thermal management system 100 operable within predetermined optimal temperature ranges. The types and methods of insulation used may depend on maximum acceptable heat loss rates for the battery 110 and the heat exchanger 116. Such heat loss rates may depend on vehicle-dependent factors as well as regional weather characteristics. In some embodiments, the battery 110 and the heat exchanger 116 are designed such that TBatt is above 0 degrees C. and TPCM is above 40 degrees C. over a period of thirty-six hours of inactivity of the vehicle 10. Operation of the thermal management system 100 under hot conditions is now described. Hot conditions occur when temperature (TBatt) of the battery 110 exceeds the optimal temperature range due to normal ohmic discharge and recharging of the battery 110. Under hot conditions, fluid in the loop 102 is made to bypass the heat exchanger 116 by controlling (e.g., closing valve to heat exchanger 116 and opening valve to bypass loop 114) the valve V2. The valve V1 controls the fluid in the loop 102 to flow through the heat exchanger 106 (e.g., air cooled heat exchanger). After receiving the fluid in the heat exchanger 106, the fan 108 is turned ON until TBatt drops below the maximum optimal temperature (e.g., 40 degrees C.). Under the hot conditions, and in some embodiments, the pump P2 may be turned ON while the valve V3 is configured to direct the fluid in the loop 104 to circulate between the internal combustion engine radiator 120 and the heat exchanger 116 to heat the phase change material (214, 218) resident in the heat exchanger 116 as described above. FIG. 3A is a cross-sectional schematic of the heat exchanger 116 shown n in FIG. 2, in accordance with some embodiments. The heat exchanger 116 includes the fluid circulation loops 102, 104, insulation 202, a fluid (e.g., coolant) filled chamber 204, a plurality of heat exchange fins 208, heat exchange tubing 210, 211, a baffle member 212, and a phase change material filled pouch 214. The fluid circulation loops 102, 104 are configured to circulate fluid to control, for example, the thermal characteristics of the battery 110, temperature of the internal combustion engine cabin 118, and the heat content of the phase change material resident in the heat exchanger 116. Such have been described above with reference to FIG. 2 and therefore will not be repeated. The chamber 204 is configured to circulate fluids received from the loops 102, 104, respectively in order to control the temperature of the circulating fluids to be within predetermined temperature ranges. The fluid circulating in the loop 102 flows within the heat exchanger 116 and the chamber 204 while fluid circulating in the loop 104 flows through the tubing 211 without flowing through the chamber 204. The heat exchange fins 208 and the heat exchange tubing 210, 211 may be provided within the pouch 214 (e.g., heavy-gauge polymer pouch) filled with phase change material. In one embodiment, the pouch 214 is configured to expand and contract as the phase change material disposed therein undergoes changes in density during phase transitions. In one embodiment, heat exchange tubing 210, 211 may share the heat exchange fins 208. As noted above, fluid circulating in the loop 104 and flowing via the tubing 211 remains within the tubing 211 during its passage through the heat exchanger 116. However, fluid circulating in the loop 102 and flowing via the tubing 210 passes from the tubing 210 into the chamber or void space 204 provided between the phase change material pouch 214 and an internal wall bounded by the insulation 202 of the heat exchanger 116. The baffle 212 blocks the pathway of the fluid circulating in the loop 102, the tubing 210, and the chamber 204 such that the fluid is forced to travel around the pouch 214 before it is allowed to leave the heat exchanger 116, thereby facilitating increased heat absorption by the phase change material resident in the heat exchanger 116. The embodiment shown in FIG. 3A may be desired where heat transfer rate to and from the phase change material provided in the pouch 214 is desired to be maintained at a predetermined level. Further, the embodiment shown in FIG. 3A may be used where an auxiliary device or a nucleation triggering device (not shown) is desired to be placed in close proximity with the phase change material filled pouch 214 to promote forced nucleation. In another embodiment, a “nucleation triggering device” may be provided within the phase change material (PCM) reservoir in order to activate the phase change material (e.g., 214, 218) on demand. This mode of activation may be provided as an alternative to autonucleation, and may be performed per the control logic (e.g., processor 101) resident in the vehicle. Enabling the phase change material to be activated on demand provides more consistent and timely nucleation of the phase change material. For example, the auxiliary device or nucleation triggering device may be employed within the tubular encapsulated phase change material within heat exchanger 1116 (FIG. 3B). An exemplary embodiment of such triggering device is a fixed stainless steel disc (e.g., fixed within a short, rigid tubular enclosure) having a slight concavity, that has several parallel thin slits cut into its interior. Upon flexure of the disc through a mechanical trigger, the interfacial dynamics between the disc and liquid phase change material induce phase change material crystallization. The inventors have demonstrated and found to be effective a device comprised solely of the stainless steel disc (having exemplary dimensions of 5/8 inch diameter by 0.02 inch thickness) to be effective for nucleating PCM materials such as sodium acetate trihydrate, ethylene carbonate, and calcium chloride hexahydrate. Stainless steel nucleators having other designs are possible. FIG. 3B is a cross-sectional schematic of the heat exchanger 116 in accordance with some embodiments wherein elements like those shown in FIG. 3A are identified using similar reference numerals, but with a prefix “1” added. In a preferred embodiment of the invention, the phase change material of the heat exchanger 1116 may be encapsulated in section(s) of flexible tubing instead of being encapsulated in spheres 218. The flexible tubing may be configured to conform to the internal space of the heat exchanger 1116 (e.g., coils, serpentine, or straight sections, etc.). The inventors have discovered that by using the flexible tubing instead of the spheres, a lower volume of encapsulant material is used for a similar volume of the phase change material. The ratio of encapsulant volume to the volume of the phase change material may be further reduced by using the flexible tubing with a thinner wall thickness. Exemplary selection criteria for the encapsulant tubing include high thermal conductivity, chemical compatibility, thermal compatibility, expandable/contractible properties of the tubing with phase change material phase changes, and increased lifetime. If wide variations of phase change material density are anticipated, then ends of the tubing may be heat-sealed or capped to allow a small volume of air to be trapped within the tubing. The heat exchanger 1116 includes fluid circulation loops 1102 and 1104, an insulation 1202, a plurality of heat exchange fins 1208, a heat exchange tubing 1211, a baffled section 220 having phase change material encapsulated in spheres 218. The encapsulating material may be polypropylene in one case. In one embodiment, the baffled section 220 with the phase change material spheres 218 is configured to surround the tubing 1211. Fluid in the circulation loop 1102 flows in the baffled pathway indicated by the arrows. The fluid in the loop 1102 is provided in intimate contact with the phase change material spheres 218. However, the fluid in the loop 1102 does not flow to disperse within the baffled section 220. The embodiment shown in FIG. 3B may be desired where the phase change material resident in the heat exchanger 1116 has an autonucleation point within a predetermined temperature range (e.g., 0-40 degrees C.). The heat exchanger 1116 shown in FIG. 3B may be easier to service, and is configured to use different phase change materials as the phase change material is encapsulated in spheres. The embodiments of the heat exchanger shown in FIGS. 3A and 3B are exemplary. Other arrangements (e.g., a plate-and-frame design with external fins) of the heat exchanger are possible. An oval or cylindrical profile of the overall heat exchanger may be preferred for some other vehicle applications. Performance of the heat exchanger (e.g., heat exchanger 116) may be optimized by using an intelligent selection of phase change materials, such as for example, organic carbonates or hydrated inorganic salts shown in Table I as above. The choice of a phase change material may be based on the vehicle type and the geographic region of the vehicle's intended use. FIG. 4 is a graph illustrating a thermal cycle for a phase change material stored in a heat exchanger (e.g., heat exchanger 116) in accordance with various embodiments of the invention. The thermal cycle path A-B-C shown in the graph indicates a normal thermal cycle, while the path A-B′-C indicates a shortened thermal cycle resulting in an incomplete release of heat from the phase change material resident in the heat exchanger 116. The general steps for the phase change material utilization cycle in accordance with the various embodiments are shown in Table II as below: TABLE II Temperature Step Change Description/Requirements 1. Activation At Ta May occur at any temperature lower than at low the melting point (Tm) but above the glass ambient transition temperature (Tg) of a metastable temperature phase change material, provided the phase (Ta) change material is in the liquid state. It is preferred to activate the phase change material via intelligent control, e.g., do not want spontaneous uncontrolled activation. 2. Chain Ta to Tf Energy Release: exothermic transition reaction from liquid to solid proceeds along a fusion thermal path that is system dependent, (exothermic) accounting for the unique rate of heat release from the phase change material. The maximum fusion temperature (Tf) is lower than the melting point as shown, and may vary according to the initial state of the phase change material system, such as, for example, phase change material mass, phase change material conductivity, configuration, rate of heat transfer to the surroundings, etc. 3. Regeneration Tf to Tm Energy Uptake: heat absorption into phase change material occurs as the material changes from a solid (ordered) to a liquid (random). Heat source would be waste heat (e.g., from internal combustion engine coolant provided in loop 104 or battery-side coolant provided in loop 102) at or above Tm. Phase change material could be heated above the melt temperature to increase its sensible heat. If stored in a well-insulated vessel, the molten phase change material may retain a high heating value. 4. phase Tm to Ta, but Phase change material is allowed to cool change over Tg and reaches its autonucleation material is temperature, whereupon it undergoes cooled by transition from liquid state to solid state. contact with Alternately, the PCM could undergo cold coolant forced nucleation while being at a under temperature above its autonucleation cold-start point, yet below its melting point. conditions FIG. 5 is a graph illustrating temperature history of a phase change material and the fluid (e.g., battery cooling fluid) circulating in the loop 102 in accordance with various embodiments of the invention. In the description of FIG. 5, references to PCM refer to the phase change material (e.g., 214, 218) resident in the heat exchanger 116 as set forth in various embodiments. Initially, the phase change material may be in a liquid state and at a higher temperature than the fluid circulating in the loop 102. Such a state is identified as “Regime 1” on the temperature-history graph of FIG. 5. The phase change material would continue to transfer heat, with a loss in temperature, until crystallization occurs at a temperature Tautonuc. After nucleation begins, crystallization spreads throughout the phase change material and is accompanied by a rise in temperature. The ultimate temperature reached by the phase change material during the second regime (e.g., Regime 2) is its melting temperature. Throughout Regime 2, heat is transferred to the fluid in the loop 102. After the phase change material crystallization is complete, the phase change material present in a solid state is still warm relative to the fluid circulating in the loop 102 and continues to deliver heat to such fluid. Such a state is identified by Regime 3. Regime 3 continues until the temperature of the phase change material and the temperature of the fluid in circulating the loop 102 are equal. During the course of normal vehicle use, battery 110 experiences ohmic-type heating as it is discharged and recharged. Excess heat from the battery 110 that is warmed may be transferred back to the phase change material as shown in Regime 4. As noted above, the phase change material is selected to undergo phase transition over a desired range of temperature. In Regime 4, transfer of heat from the loop 102 to the phase change material continues so long as the temperature of the battery 110 is higher than the temperature of the phase change material. Continued heat transfer to the phase change material would result in melting of the phase change material until the phase change material is in a completely liquid state (Regime 5). Additional heating of the phase change material that is in the liquid state may be possible and identified by Regime 6. The additional heat may be provided from warm batteries (e.g., battery 110), or from an internal combustion engine as in the case of hybrid electric vehicles. At the conclusion of Regime 6, the phase change material is fully charged and ready for another cycle of operation. The following equations estimate temperatures of the fluid in the heat exchanger (e.g., heat exchanger 116) in accordance with various embodiments, as a function of time throughout a complete discharge and recharge cycle of the phase change material. For the battery coolant fluid (e.g., fluid in the loop 102): QBL=mBL×CP,EG×(TBL,out−TBL,in) (1) For the combustion engine coolant fluid (e.g., fluid in the loop 104): QCE=hCE×ACE×(TCE,ave−TBL,ave)=mCE×CP,EG×(TCE,in−TCE,out) (2) For the phase change material (e.g., phase change material 214, 218) housed in a cylindrical container (e.g., in heat exchanger 116, heat exchanger 1116), heat loss from a cylinder: Q PCM = 2 π Lk PCM × ( T c - T W , i n ) = 2 π Lk W × ( T W , i n - T W , out ) / ln ( r out / r in ) = h BL × A BL × ( T W , out - T BL , ave ) ( 3 ) The above-noted rate equations are coupled with an energy equation written for the sensible heat change or heat of fusion change for the phase change material over a small time step, Δt: For sensible heat change: QPCM=MPCM×CP,PCM×(Tf,PCM−Ti,PCM)/Δt (4a) For heat change associated with crystallization/melting: QPCM=[MPCM×ΔH−MPCM×CP,PCM×(Tmelt−Tc)]/Δt (4b) where ABL=heat transfer area at the battery fluid (e.g., fluid in the loop 102) and phase change material container (e.g., heat exchanger 116, heat exchanger 1116) interface ACE=heat transfer area of combustion engine exchanger CP,EG=heat capacity of fluid (e.g., in the loop 102) coolant (ethylene glycol) CP,PCM=heat capacity of the phase change material ΔH=heat of fusion for the phase change material Δt=time step hBL=convective heat transfer coefficient for the battery coolant fluid at the exterior wall of the phase change material container hCE=convective heat transfer coefficient for the combustion engine coolant fluid (e.g., fluid in the loop 104) kPCM=thermal conductivity of the phase change material kW=thermal conductivity of the wall material holding the phase change material L=length of cylinder housing the phase change material MPCM=mass of phase change material mBL=mass flow rate of battery coolant fluid mCE=mass flow rate of combustion engine coolant QBL=heat transfer rate for the battery coolant QCE=heat transfer rate for the combustion engine coolant QPCM=heat transfer rate for the phase change material ri, ro=inner, outer radius of cylinder holding the phase change material TBL=temperature of the battery coolant fluid Tc=centerline temperature of phase change material TCE=temperature of combustion engine coolant fluid Tf,PCM=phase change material temperature at the end of time step Ti,PCM=phase change material temperature at the start of time step Tmelt=melting temperature of phase change material TW=wall temperature of container holding phase change material Depending on the regime being modeled, the above-described equations may be solved iteratively for small time steps to provide a temperature profile as a function of time. In a control volume approach, thermal analysis of the battery or battery module 110 involves applying the conservation of energy equation (e.g., first-law analysis) to a control volume having encapsulated battery (e.g., battery 110) identified as “V” in the below equations: The general equation may be provided as follows: δ Q dt - δ W s dt ↑ = ∫ ∫ cs ( e + p ρ ) ρ ↑ ( v _ • n _ ) ⅆ A + ∂ ∂ t ∫ ∫ ∫ cv e ρ ⅆ V + δ W M dt ↑ + δ Q source dt where quantities marked by an arrow would have zero or near-zero values in some cases. Thus, for the thermal management system 100 according to various aspects: δ Q dt = ∂ ∂ t ∫ ∫ ∫ cv e ρ ⅆ V + δ Q source dt For discrete Δ t , δ Q source dt ≅ q . source V for q . source ( = ) Energy Vol •time ∴ [ δ Q dt = ∂ ∂ t ∫ ∫ ∫ cv e ρ ⅆ V + q . source V ] ( 1 ) In some cases, {dot over (q)}source V is not shown as a separate term. Following that convention: [ δ Q dt = ∂ ∂ t ∫ ∫ ∫ cv e ρ ⅆ V ] ( 2 ) The left hand side (LHS) of Equation (2) shows: δ Q dt : . The rate of heat addition (or subtraction) to the control volume is due to both convection from the heat transfer medium and the internal heat source. Thus, we define [ δ Q dt = hA ( T ∞ - T ) + q . source V ] ( 3 ) where h is the heat transfer film coefficient or convection coefficient; A≡heat transfer surface area (encapsulated cylinder wall plus one end). The right hand side (RHS) of Equation (2) shows: ∂ ∂ t ∫ ∫ ∫ cv e ρ ⅆ V : The rate of energy increase within the control volume, assuming constant properties, can be expressed as [ ∂ ∂ t ∫ ∫ ∫ cv e ρ ⅆ V = ρ Vc p ⅆ T ⅆ t ] , ( 4 ) a thermodynamic-based relation. Setting RHS's of Eqs. (3) and (4): [ ρ Vc p ⅆ T ⅆ t = hA ( T ∞ - T ) + q . source V ] or ⅆ T ⅆ t = 1 ρ Vc p [ hA ( T ∞ - T ) + q . source V ] ( 5 ) The above provides three independent equations and three unknowns under the method based on the lumped-parameter model (LPM). [ Δ T Δ t ≅ ( 1 ρ Vc p ) Batt [ hA ( T ∞ - T ) + ↑ i . e . q . source ( T ) q . source V ] ] ( 6 ) where ΔT≡T−To T is unknown ρ, V, cp for battery Alternately, the exact analytical solution of Eq (6) in differential form is ( hA ( T ∞ - T ) + q . ( T ) V hA ( T ∞ - T o ) + q . ( T o ) V ) = ⅇ - ( h A t ρ Vc p ) Batt Here, T and T∞ are unknown. Δ Q cell Δ t = hA ( T ∞ - T ) + q . source V ( 7 ) or, more properly [ Δ Q cell Δ t ≅ hA ( T ∞ - T ) + q . source ( T ) V ] Unknowns are (ΔQ, T∞, T). Regarding heat received by ( M ) resident and m . Labile coolant in/through battery module (e.g., battery 110), given here on a “per N cells” basis Δ Q cool Δ t ≅ { m . C p Δ T } form ❘ Note that [ Δ Q cool = N cell Δ Q cell ] ( 8 ) In the following two expressions, the first applies if Cp is f(T); otherwise, the second expression holds. [ Δ Q cool Δ t = ( m . Batt cool + M Batt cool Δ t ) ( C p ( T ∞ ) T ∞ - C p ( T ∞ o ) T ∞ o ) Δ Q cool Δ t = ( m . + M Δ t ) C p ( T ∞ - T ∞ o ) ] Unknowns are (ΔQcell, T∞). T∞( ) is initial or inlet coolent T with respect to Batt. Since Cp for liquids beneath their boiling points is generally reasonably constant, then the simpler form of Eq. (8) shown above is justified. However, the source heat term is firmly dependent on T. Thus, the above equations may be summarized as Δ T Δ t = ( T - T 0 ) Δ t ≅ ( 1 ρ Vc p ) Batt [ hA ( T ∞ - T ) + q . source ( T ) V ] ( 9 ) [ Δ Q cell Δ t ≅ hA ( T ∞ - T ) + q . source ( T ) V ] ( 10 ) N cell Δ Q cell Δ t ≅ ( m . + M Δ t ) Batt cool -- -- -- -- ↓ or other representation C P cool ( T ∞ - T ∞ o ) ( 11 ) Since {dot over (q)}source(T) depends on average or representative T over Δt, then solving these equations for the unknowns (T, T∞, ΔQcell) may require an iterative method while checking the Biot (Bi) number to verify applicability of the lumped-parameter model (LPM) for heat transfer. Bi ≡ hV / A k ; Bi≦0.2 for LPM to be valid. One such iterative method involves the following elements: 1. Estimate T (Tguess) 2. Determine {dot over (q)}source (T)—(from battery data as f(T) or Ohmic heating expression) 3. Solve set of equations for (T, T∞, ΔQcell) 4. Check value of Tsolved vs Tguess 5. Update Tguess and repeat steps 2-4 until determined agreement is seen between Tsolved and Tguess. Aspects of the invention provide various advantages, which in some embodiments include an option to perform electrical preheating of vehicles. The thermal management system having the phase change material (e.g., an intelligent-based phase change material) would preheat vehicle components in accordance with preset options (e.g., regionally defined), thus eliminating the need for a user to connect (e.g., plug) or disconnect (e.g., unplug) an electrical heater before and after each use. Effective thermal management of hybrid electrical vehicles (HEVs) increases battery efficiency by maintaining favorable electrolyte conductivity, while extending battery lifetime by avoiding excessive temperatures. Thus, replacement of the batteries may be foregone until well within the expected lifetime of the batteries. Consequently, an HEV having the thermal management system in accordance with various aspects would have greater power at low temperatures. Additionally, comforts of a passenger cabin of the vehicle may be enhanced by using the thermal management system, in accordance with various aspects, during cold-start conditions, as the design of the thermal management system permits excess thermal energy to be directed to the cabin heater core (e.g., internal combustion engine cabin 118) as determined by control logic protocol described above. In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>Hybrid electric vehicles (HEVs) and electric vehicles (EVs) provide improved fuel economy and reduced air emissions over conventional vehicles. The performance of HEVs and EVs depend on energy storage systems such as batteries. Battery performance influences, for example, acceleration, fuel economy, and charge acceptance during recovery from regenerative braking. As the cost of the batteries, durability, and life-cycle affect the cost and reliability of a vehicle using the batteries for vehicular operation, parameters that affect the efficiency of the batteries may have to be optimized to achieve optimized vehicular performance. It is known that temperature has an influence over battery performance. Battery modules carrying batteries are preferred to operate within an optimum temperature range that is suitable for a particular electrochemical pair. For example, the desired operating temperature for a lead acid battery is 25° C. to 45° C. Battery modules may also have to be operated at uniform temperatures as uneven temperature distribution may result in varied charge-discharge behavior. Such varied charge-discharge behavior may lead to electrically unbalanced modules and reduced battery performance. HEVs may be less reliable in northern latitudes due to cold temperature constraints imposed on the batteries carried by the HEVs. Lithium ion batteries have been a candidate for use in HEVs, and such batteries have optimum performance when operating from 0-40° C. Below 0° C., power output of the batteries diminishes and the effect of temperature becomes more severe as the level of discharge increases. Conversely, as temperatures exceed above 40° C., detrimental cathode corrosion and other irreversible reactions may occur resulting in shortened battery life. Accordingly, a battery thermal management system (TMS) is needed to achieve desired and reliable performance in varied climatic conditions while minimizing temperature excursions outside a desired temperature range. | <SOH> SUMMARY OF THE INVENTION <EOH>Aspects of the invention also relate to a comprehensive thermal management system for hybrid electric vehicles which include both an internal combustion engine and battery based locomotion (example, lithium-ion, or nickel metal hydride). Aspects of the invention also disclose a thermal management system configured to provide a mechanism to pre-warm a vehicle's battery module, having a plurality of individual cells, in cold conditions, provide auxiliary warmth to the module as needed, and remove heat from it as the batteries heat up due to normal ohmic discharge and recharge. In some embodiments, a thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein. The thermal management system includes a first coolant loop thermally coupled to an electro-chemical storage device located within the first coolant loop and to the heat exchanger, a second coolant loop, thermally coupled to the heat exchanger, the first and second loops configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided. In other embodiments, a thermal management system for a hybrid electric vehicle includes a heat exchanger having a phase change material provided therein, a first fluid loop having a first coolant mixture flowing therein, and a second fluid loop having a second coolant mixture flowing therein, the second coolant mixture being distinct from the first coolant mixture. The first and second fluid loops are configured to be in thermal communication with the heat exchanger, the heat exchanger being configured to flow only the first coolant mixture within the heat exchanger. The thermal management system also includes a thermal interface configured to transfer heat produced by an internal combustion engine of the vehicle to the heat exchanger, the heat exchanger being configured to store the heat generated by the internal combustion engine and selectively provide the stored heat to control thermal characteristics of various components of the vehicle including the battery module. In yet other embodiments, a thermal management method for a vehicle includes providing a heat exchanger having a thermal energy storage material disposed therein, providing first and second coolant loops to circulate distinct coolant mixtures through the respective first and second coolant loops, thermally coupling the first coolant loop to a battery module located within the first coolant loop, thermally coupling the second coolant loop to the heat exchanger, and providing an interface in close proximity to the second coolant loop. The interface is configured to transfer heat generated by an internal combustion engine of the vehicle to the heat exchanger, via the second coolant loop, for storage within the thermal energy storage material. The method also includes selectively performing one or more of preheating the battery module, heating a passenger cabin of the vehicle, increasing sensible heat or latent heat of fusion of the material from a first thermal state to a higher second thermal state using the heat stored within the thermal energy storage material. | 20040204 | 20061212 | 20050804 | 94726.0 | 0 | BOTTORFF, CHRISTOPHER | THERMAL MANAGEMENT SYSTEMS AND METHODS | SMALL | 0 | ACCEPTED | 2,004 |
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10,772,914 | ACCEPTED | Natural sunscreen compositions and processes for producing the same | Disclosed is a natural sunscreen composition comprising extracts of Hedychium spicatum and/or Alpinia galanga containing active sunscreen agents, the sunscreen composition devised to protect the skin from the harmful effects of short wavelength UV B rays and long wavelength UV A rays. | 1. A natural sunscreen composition comprising extract of plant Hedychium spicatum and/or plant Alpinia galanga and a cosmetically acceptable carrier. 2. The natural sunscreen composition according to claim 1, wherein the composition comprises 0.001% to 20% by weight of the extract of plant Hedychium spicatum and/or plant Alpinia galanga. 3. The natural sunscreen composition according to claim 1, wherein the cosmetically acceptable carrier comprises by weight; 0.55% of Glyceryl mono stearate, 0.80% of Cetyl alcohol, 0.50% of Cetostearyl alcohol, 2.80% of Heavy liquid paraffin, 1.00% of Silicone oil, 0.68% of Sorbitan stearate, 2.20% of Isostearic acid, 0.50% of Polysorbate 60, 3.50% of Acrylates copolymer, 0.14% of Sodium hydroxide, 3.00% of Glycerin, 0.55% of Titanium dioxide, 0.20% of Methyl paraben, 0.10% of Propyl paraben and Demineralised water. 4. A delivery system for topical application, comprising the natural sunscreen composition according to claim 1, wherein the delivery system comprises creams, shampoos, gels, lotions, soaps, oils, sticks or sprays as a vehicle for topical application of said sunscreen composition. 5. A natural sunscreen composition comprising cinnamic acid esters isolated and characterized from the extract of plant Hedychium spicatum and/or plant Alpinia galanga and a cosmetically acceptable carrier. 6. The natural sunscreen composition according to claim 5, wherein the composition comprises cinnamic acid esters individually or as mixtures thereof. 7. The natural sunscreen composition according to claim 5, wherein the composition comprises 0.001% to 12% by weight of cinnamic acid esters. 8. The natural sunscreen composition according to claim 5, wherein the cosmetically acceptable carrier comprises by weight; 0.55% of Glyceryl mono stearate, 0.80% of Cetyl alcohol, 0.50% of Cetostearyl alcohol, 2.80% of Heavy liquid paraffin, 1.00% of Silicone oil, 0.68% of Sorbitan stearate, 2.20% of Isostearic acid, 0.50% of Polysorbate 60, 3.50% of Acrylates copolymer, 0.14% of Sodium hydroxide, 3.00% of Glycerin, 0.55% of Titanium dioxide, 0.20% of Methyl paraben, 0.10% of Propyl paraben and Demineralised water. 9. A delivery system for topical application, comprising the natural sunscreen composition according to claim 5, wherein the delivery system comprises creams, shampoos, gels, lotions, soaps, oils, sticks or sprays as a vehicle for topical application of said sunscreen composition. 10. A natural sunscreen composition according to claim 5 comprising 0.001 to 8% by weight of Cinnamic acid esters and a cosmetically acceptable carrier which comprises by weight; 0.25% of Glyceryl monostearate, 6.50% of Stearic acid, 5.50% of Light liquid paraffin, 1.50% of Isopropyl myristate, 1.20% of Cetyl alcohol, 0.80% of Cresmer 1000, 1.20% of Cetostearyl alcohol, 0.60% of Brii 36, 0.20% of Methyl paraben, 0.10% of Propyl paraben, 5.00% of Glycerin, 0.80% of Triethanol amine, Fragrance and Demineralised water. 11. A delivery system for topical application, comprising the natural sunscreen composition according to claim 10 wherein the delivery system comprises creams, shampoos, gels, lotions, soaps, oils, sticks or sprays as a vehicle for topical application of said sunscreen composition. 12. A natural sunscreen composition according to claim 5 comprising 0.001 to 8% by weight of Cinnamic acid esters and a cosmetically acceptable carrier which comprises by weight; 40% of Sodium lauryl ether sulphate, 1.00% of Cocodiethanolamide, 5.00% of Betaine, 1.00% of Sodium chloride, 0.50% of Silicone emulsion, 0.20% of Methyl paraben, 0.10% of Propyl paraben, Fragrance, Colour and Demineralised water. 13. A delivery system for topical application, comprising the natural sunscreen composition according to claim 12, wherein the delivery system comprises creams, shampoos, gels, lotions, soaps, oils, sticks or sprays as a vehicle for topical application of said sunscreen composition. 14. A natural sunscreen composition according to claim 5 comprising 0.001 to 8% by weight of Cinnamic acid esters and a cosmetically acceptable carrier which comprises by weight; 35.00% of Sodium lauryl ether sulphate, 1.20% of Carbomer, 5.00% of Betaine, 0.80% of Triethanol amine, 0.50% of Silicone emulsion, 5.00% of Glycerin, 0.20% of Methyl paraben, 0.10% of Propyl paraben, Fragrance and Demineralised water. 15. A delivery system for topical application, comprising the natural sunscreen composition according to claim 14, wherein the delivery system comprises creams, shampoos, gels, lotions, soaps, oils, sticks or sprays as a vehicle for topical application of said sunscreen composition. 16. A method of producing a natural sunscreen composition, the method comprising: extracting plant extracts from Hedychium spicatum by percolation or hot-soxhalation; filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and employing the dried mass and a cosmetically acceptable carrier to produce a natural sunscreen composition. 17. A delivery system for topical application, comprising the natural sunscreen composition produced according to the method of claim 16, the delivery system comprising creams, shampoos, gels, lotions, soaps, oils, sticks or sprays. 18. A method of producing a natural sunscreen composition, the method comprising: extracting plant extracts from Alpinia galanga by percolation or hot-soxhalation; filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and employing the dried mass and a cosmetically acceptable carrier to produce a natural sunscreen composition. 19. A delivery system for topical application, comprising the natural sunscreen composition produced according to the method of claim 18, the delivery system comprising creams, shampoos, gels, lotions, soaps, oils, sticks or sprays. 20. A method of producing a natural sunscreen composition, the method comprising extracting plant extracts from Hedychium spicatum or Alpinia galanga by percolation or hot-soxhalation, filtering the plant extract, purifying the extract by crystallization to obtain pure cinnamic acid esters and employing the pure cinnamic acid esters thus produced and a cosmetically acceptable carrier to produce a natural sunscreen composition. 21. A delivery system for topical application, comprising the natural sunscreen composition produced according to the method of claim 20, the delivery system comprising creams, shampoos, gels, lotions, soaps, oils, sticks or sprays. 22. A method of producing a natural sunscreen composition, the method comprising: extracting plant extracts from Hedychium spicatum or Alpinia galanga by solvent extraction using an organic solvent; subjecting the resultant extract to purification; separating the pure compound; characterizing the same as cinnamic acid esters; and producing a natural sunscreen composition employing the pure cinnamic acid esters thus produced and a cosmetically acceptable carrier. 23. The method according to claim 22, wherein the organic solvent is selected from the group consisting of petroleum ether, hexane, cyclohexane, benzene, dichloromethane, chloroform, ethyl acetate, acetone, methanol and ethanol. 24. The method according to claim 23, wherein the organic solvent is used either alone or in combination thereof. 25. A delivery system for topical application, comprising the natural sunscreen composition produced according to the method of claim 23, the delivery system comprising creams, shampoos, gels, lotions, soaps, oils, sticks or sprays. | BACKGROUND OF THE INVENTION 1. Field of the Invention This invention, in general, relates to cosmetic compositions. More specifically, this invention relates to natural sunscreen compositions and processes for producing the same. 2. Description of the Related Art Human skin is sensitive to solar rays and overexposure to sun can cause not only simple sunburn or an erythema, but also burns of varying severity. The other negative effects of over-exposure to solar rays are, tanning, immune suppression, photosensitivity or drug related photosensitivity and photo allergies. Sun can also cause the skin to lose its elasticity and form wrinkles, leading to premature ageing. Dermatosis may also be caused due to over-exposure to solar rays. In extreme cases, some people can develop skin cancer. Outdoor activities including typical field-related jobs and sporting activities expose the skin to sun. It has been estimated that nearly 75 percent of the sun-inflicted skin damage on the average person's skin over a lifetime is the result of being just outdoors. Hence we require a protection so that we can expose ourselves to the sunlight without getting harmed. These concerns have been heightened by evidence that the earth's ozone layer has suffered severe depletion in recent years. Ozone is recognized as the stratospheric component shielding against the harmful forms of ultraviolet radiation. But still 5% of the sunrays coming to the earth are composed of the ultraviolet rays. These ultraviolet rays are composed of the shorter-wavelength (290-320 nm) UVB rays that cause indirect sun tanning and the longer-wavelength (320-400 nm) UVA rays that are responsible for direct sun tanning. Sunscreen compositions offer a scientific solution to the above-identified harmful effects of over-exposure to the ultraviolet rays. Topical application sunscreen formulations are known. Sunscreen active are generally classified as organic sun screeners or inorganic sun screeners. Organic sun screeners absorb strongly at specific wavelengths and are transparent to visible light. However, some organic sun screeners such as Oxybenzone are known to cause photo allergic reactions. Inorganic sun screeners such as Titanium dioxide at higher levels leave visible residue referred as whitening of the skin. To overcome these allergic side effects of organic sun screeners and non-aesthetics of inorganic sun screeners, there exist the need for devising newer formulations, that can protect the skin from the harmful effects of the ultraviolet radiations of sun without any undesirable side effects. It is against this background the present invention has been brought out. U.S. Pat. No. 6,500,869 to Driller et al. discloses a sun protection formulation in solid or liquid form containing organic or inorganic sunscreen filters for a prophylactic action. Disclosed in this patent are substances of cinnamic acid derivatives, in particular octyl p-methoxycinnamate that function not only as light protection filters, but also as solvents for other UV filters and are therefore often used in combination with various filters. U.S. Pat. No. 6,537,529 to Bonda et al. discloses a method of preparing a sunscreen including a solvent system and a filter system, as well as sunscreen compositions and compounds for producing sunscreen compositions. U.S. Pat. No. 5,773,014 to Perrier et al. discloses a composition to inhibit the formation of unwanted skin pigmentation. The active components of the composition include extracts of selected plants, namely, mulberry, saxifrage, grape and scutellaria root; and, preferably, ethylene diamine tetra acetic acid (EDTA). U.S. Pat. No. 6,440,402 to Gonzalez et al. discloses the synergistic action of Kaempferia galanga root extract in sunscreen formulation. The invention also discloses a method comprising introducing into the composition an amount of extract of Kaempferia galanga plant sufficient to enhance the photostability of the sunscreen active. U.S. Pat. No. 5,756,099 to Simpson et al. discloses a process of preparing natural, organic, topical tanning sunscreen compositions comprising extracting the embryonic, spongy mass of tissue of the coconut from the drupe and adding it to the flesh of papaya in a proportional ratio of 1:3. Sunscreen compositions comprising herbal extracts that can act as antioxidants are known in prior art. Sunscreen compositions containing herbal extracts such as green tea, aloe vera, calendula, chamomile rosemary are also known in the art. Further, it is known in the art to devise sunscreen compositions having cinnamic acid esters, wherein the cinnamic acid esters act as sunscreen actives. The present invention is distinct from the above prior art compositions as described hereunder. SUMMARY OF THE INVENTION In one preferred embodiment, there is provided a safe and effective natural sunscreen composition comprising extract of plant Hedychium spicatum and plant Alpinia galanga and a cosmetically acceptable carrier. In another preferred embodiment, there is provided a safe and effective natural sunscreen composition comprising extract of plant Hedychium spicatum or plant Alpinia galanga and a cosmetically acceptable carrier. In yet another preferred embodiment, there is provided a safe and effective natural sunscreen composition comprising cinnamic acid esters, individually or mixtures thereof, isolated and characterized from the extract of plant Hedychium spicatum and a cosmetically acceptable carrier. In still another preferred embodiment, there is provided a safe and effective natural sunscreen composition comprising cinnamic acid esters, individually or mixtures thereof, isolated and characterized from the extract of plant Alpinia galanga and a cosmetically acceptable carrier. In one another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises Hedychium spicatum extract (0.001% to 20%), Glyceryl mono stearate (0.55%), Cetyl alcohol (0.80%), Cetostearyl alcohol (0.50%), Heavy liquid paraffin (2.80%), Silicone oil (1.00%), Sorbitan stearate (0.68%), Isostearic acid (2.20%), Polysorbate 60 (0.50%), Acrylates copolymer (3.50%), Sodium hydroxide (0.14%), Glycerin (3.00%), Titanium dioxide (0.55%), Methyl paraben (0.20%) and Propyl paraben (0.10%) and demineralized water. In a preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises Alpinia galanga extract (0.001% to 20%), Glyceryl mono stearate (0.55%), Cetyl alcohol (0.80%), Cetostearyl alcohol (0.50%), Heavy liquid paraffin (2.80%), Silicone oil (1.00%), Sorbitan stearate (0.68%), Isostearic acid (2.20%), Polysorbate 60 (0.50%), Acrylates copolymer (3.50%), Sodium hydroxide (0.14%), Glycerin (3.00%), Titanium dioxide (0.55%), Methyl paraben (0.20%), Propyl paraben (0.10%), and demineralized water. In still another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 8%), Glyceryl mono stearate (0.55%), Cetyl alcohol (0.80%), Cetostearyl alcohol (0.50%), Heavy liquid paraffin (2.80%), Silicone oil (1.00%), Sorbitan stearate (0.68%), Isostearic acid (2.20%), Polysorbate 60 (0.50%), Acrylates copolymer (3.50%), Sodium hydroxide (0.14%), Glycerin (3.00%), Titanium dioxide (0.55%), Methyl paraben (0.20%) and Propyl paraben (0.10%), and demineralized water. In yet another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 12%), Glyceryl mono stearate (0.55%), Cetyl alcohol (0.80%), Cetostearyl alcohol (0.50%), Heavy liquid paraffin (2.80%), Silicone oil (1.00%), Sorbitan stearate (0.68%), Isostearic acid (2.20%), Polysorbate 60 (0.50%), Acrylates copolymer (3.50%), Sodium hydroxide (0.14%), Glycerin (3.00%), Titanium dioxide (0.55%), Methyl paraben (0.20%) and Propyl paraben (0.10%), and demineralized water. In yet another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 8%), Glyceryl mono stearate (0.250%), Stearic acid (6.50%), Light liquid paraffin (5.50%), Isopropyl myristate (1.50%), Cetyl alcohol (1.20%), Cresmer 1000 (0.80%), Cetostearyl alcohol (1.20%), Brii 36 (0.60%), Methyl paraben (0.20%), Propyl paraben (0.10%), Glycerin (5.00%), Triethanol amine (0.80%), Fragrance (qs) and DM Water (qs to 100). In yet another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 8%), Sodium lauryl ether sulphate (40%), Cocodiethanolamide (1.00%), Betaine (5.00%), Sodium chloride (1.00%), Silicone emulsion (0.50%), Methyl paraben (0.20%), Propyl paraben (0.10%), Fragrance (qs), Colour (qs) and DM Water (qs to 100). In yet another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 8%), Sodium lauryl ether sulphate (35.00%), Carbomer (1.20%), Betaine (5.00%), Triethanol amine (0.80%), Silicone emulsion (0.50%), Glycerin (5.00%), Methyl paraben (0.20%), Propyl paraben (0.10%), Fragrance (qs) and DM Water (qs to 100). It is an aspect of the present invention to provide for a method of producing a natural sunscreen composition, the method comprising extracting plant extracts from Hedychium spicatum by percolation, filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and producing a natural sunscreen composition employing the said dried mass and a cosmetically acceptable carrier. In still another aspect, the present invention provides for a method for producing a natural sunscreen composition, the method comprising extracting plant extracts from Hedychium spicatum by hot-soxhalation, filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and producing a natural sunscreen composition employing the said dried mass and a cosmetically acceptable carrier. It is an aspect of the present invention to provide for a method for producing a natural sunscreen composition, the method comprising extracting plant extracts from Alpinia galanga by percolation, filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and producing a natural sunscreen composition employing the said dried mass and a cosmetically acceptable carrier. In still another aspect, the invention provides for a method for producing a natural sunscreen composition, the method comprising extracting plant extracts from Alpinia galanga by hot-soxhalation, filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and producing a natural sunscreen composition employing the said dried mass and a cosmetically acceptable carrier. In yet another aspect, the invention provides for a method for producing a natural sunscreen composition, the method comprising extracting extracts of plant Hedychium spicatum or Alpinia galanga by percolation or hot-soxhalation, filtering the plant extract, purifying the extract by crystallization to obtain pure cinnamic acid esters and producing a natural sunscreen composition employing the pure cinnamic acid esters thus obtained and a cosmetically acceptable carrier. In yet another aspect, the invention provides for a method for producing a natural sunscreen composition, the method comprising extracting plant extracts from Hedychium spicatum or Alpinia galanga by solvent extraction using an organic solvent selected from the group comprising petroleum ether, hexane, cyclohexane, benzene, dichloromethane, chloroform, ethyl acetate, acetone, methanol and ethanol, either alone or in combination thereof, purifying the resultant extract; separating the pure compound; characterizing the compound as cinnamic acid esters and producing the natural sunscreen composition using the cinnamic acid esters thus produced and a cosmetically acceptable carrier. In yet another preferred embodiment, the present invention provides for a delivery system containing a natural sunscreen composition comprising extract of plant Hedychium spicatum and plant Alpinia galanga and a cosmetically acceptable carrier. In still another preferred embodiment, the present invention provides for a delivery system containing a natural sunscreen composition comprising extract of plant Hedychium spicatum and plant Alpinia galanga and a cosmetically acceptable carrier wherein the delivery system includes creams, shampoos, gels, lotions, soaps, oils, sticks or sprays. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The invention involves identification and selection of the herbs and obtaining the extract by subjecting the same to solvent extraction. Hedychium spicatum, a perennial rhizomatous herb is widely found in western and eastern parts of Himalaya. Rhizomes possess a strong aromatic odour and bitter camphoraceous taste. The rhizomes are stomachic, carminative, stimulant and tonic. They are used in dyspepsia. (Nadkarni, I, 608; Dastur, Useful plants, 122; Taylor & Dutt; Proc. Nat. Acad. Sci. India, 1940, 10A, 17). The dried rhizomes of commerce on steam distillation yield 4% of an essential oil and its main constituent being ethyl-p-methoxy cinnamate. The oil may be used as perfume for soaps; hair oils and face powders etc. (Taylor & Dutt, Loc. Cit; Dymock, Warden& Hooper, III, 419. Finnemore, 182; Wehner, I, 179, Chem Abstr; 1940, 3A, 6015). The presence of alkaloids, saponins and flavonoids has been reported in the rhizomes (Suchitra Kumar et al. J. Econ. Bot Phytochem, 1990, I, 13.) The ethanolic extract of dried rhizomes showed antibacterial activity. (Venkata Narayana et al. Indian Med. 1989, 1, 6; Mishra et al. Int J Pharmacogn, 1991, 29, 19). Alpinia galanga is an herb, 1.8-2.4 m in height, with tuberous aromatic rootstocks, occurring throughout India and cultivated for its rhizomes. The rhizomes are considered as tonic, stomachic, carminative and stimulant, and are used as a fragrant adjunct to complex preparations and also in cough and digestive mixtures. Fresh rhizomes of Alpinia galanga on steam distillation yield an essential oil (0.04%) with a peculiar strong and spicy odour. The oil contains methyl cinnamate (48%), cineol (20-30%), camphor and probably d-pipene. The oil is carminative and in moderate doses has an anti-spasmodic action on involuntary muscle tissue. Disclosed herein is the process of extraction of herbs, the process comprising shade drying fresh rhizomes of Hedychium spicatum and/or Alpinia galanga and powdering the dried material coarsely. Each plant material is subjected to solvent extraction by percolation method. About 1 Kg of plant material is taken in separate flasks and soaked with petroleum ether, hexane, cyclo-hexane, benzene, dichloromethane, chloroform, ethyl acetate, acetone, methanol and ethanol for two days. All solvent extracts are drained out and filtered through Whatman Filter No.1 and concentrated to dryness on rotatory evaporator under vacuum at optimum temperature. The residual material is extracted further until all compounds are extracted. Alternately, the extraction is also performed by hot-soxhalation method for three times and processed as above. The extract of the plant Hedychium spicatum is obtained by subjecting the rhizome thereof to a system of organic solvents from non-polar to polar solvents by percolation and hot-soxhalation methods. The solvent extraction with n-hexane under cold extraction for three days at room temperature and hot-refluxing at optimum temperature for three cycles was found to be very simple and unique process for obtaining 24.79% (highest yield of actives in comparison to other solvents used for extraction) of extract containing 60-70% of active cinnamic acid esters. The yields of Hedychium spicatum extract were found to be n-Hexane (24.79%), Cyclo-hexane (21.12%), Petroleum ether (15.06%), Chloroform (24.72%), Dichloromethane (14.22%), Ethyl acetate (13.87%), Acetone (17.71%), Methanol (21.61%) and Ethyl Alcohol (18.42%). The yields of Alpinia galanga extract were found to be n-Hexane (19.15%), Cyclo-hexane (18.16%), Petroleum ether (14.76%), Chloroform (21.16%), Dichloromethane (14.25%), Ethyl acetate (12.25%), Acetone (15.75%), Methanol (20.54%) and Ethyl Alcohol (17.42%). All solvent extracts obtained as oil form are kept for crystallization at room temperature from 1 to 2 days and pure crystalline mixture thus obtained is washed with n-hexane (2 to 3 washes) and recrystallised in methanol to produce pure form of cinnamic acid esters. This method is simple, cost effective and applicable to bulk scale production. The isolation of individual pure compounds is achieved by column chromatography over silica gel and eluted with n-hexane and ethyl acetate mixture as each pure compound was crystallized with hexane-ethyl acetate solvent system. A crude mixture of cinnamic acid esters was analysed by HPTLC using Hexane and Ethyl acetate as mobile phase. The spots were visualized in Iodine vapour and also under UV light showing many closely related spots. The isolation of cinnamic acid esters is achieved by column chromatography over silica gel (60-120 mesh) using hexane and ethyl acetate as eluent and 250 ml fractions are collected and pooled accordingly after performing HPTLC. All fractions are subjected to 4 semi-purified fractions. Further purification of these fractions is carried on HPLC using methanol as mobile phase over RP-18 column. The isolated fractions were characterized by NMR and GC-MS and identified as P-methoxy cinnamic acid esters (STR#1 to STR#5), p-ethoxy cinnamic acid esters (STR#6 to STR#11) and p-hydroxy benzyl cinnamic acid esters (STR#12 and STR#13). Preferred embodiments are further illustrated in the following examples. These examples illustrate particular embodiments of the invention and are not intended to limit the scope of the invention in any way. EXAMPLE 1 Sl No. Ingredients % by weight 1 Hedychium spicatum extract 0.001 to 20 2 Glyceryl mono stearate 0.55 3 Cetyl alcohol 0.80 4 Cetostearyl alcohol 0.50 5 Heavy liquid paraffin 2.80 6 Silicone oil 1.00 7 Sorbitan stearate 0.68 8 Isostearic acid 2.20 9 Polysorbate 60 0.50 10 Acrylates copolymer 3.50 11 Sodium hydroxide 0.14 12 Glycerin 3.00 13 Titanium dioxide 0.55 14 Methyl paraben 0.20 15 Propyl paraben 0.10 16 DM water qs to 100 SPF: 13.97 Analysed by in vitro method using SPF 290S analyser EXAMPLE 2 Sl No. Ingredients % by weight 1 Alpinia galanga extract 0.001 to 20 2 Glyceryl mono stearate 0.55 3 Cetyl alcohol 0.80 4 Cetostearyl alcohol 0.50 5 Heavy liquid paraffin 2.80 6 Silicone oil 1.00 7 Sorbitan stearate 0.68 8 Isostearic acid 2.20 9 Polysorbate 60 0.50 10 Acrylates copolymer 3.50 11 Sodium hydroxide 0.14 12 Glycerin 3.00 13 Titanium dioxide 0.55 14 Methyl paraben 0.20 15 Propyl paraben 0.10 16 DM water qs to 100 SPF: 12.5 Analysed by in vitro method using SPF 290S analyser EXAMPLE 3 Sl No. Ingredients % by weight 1 A cinnamic acid esters active fraction 0.001 to 8 2 Glyceryl mono stearate 0.55 3 Cetyl alcohol 0.80 4 Cetostearyl alcohol 0.50 5 Heavy liquid paraffin 2.80 6 Silicone oil 1.00 7 Sorbitan stearate 0.68 8 Isostearic acid 2.20 9 Polysorbate 60 0.50 10 Acrylates copolymer 3.50 11 Sodium hydroxide 0.14 12 Glycerin 3.00 13 Titanium dioxide 0.55 14 Methyl paraben 0.20 15 Propyl paraben 0.10 16 DM water qs to 100 SPF: 19.12 Analysed by in vitro method using SPF 290S analyser EXAMPLE 4 Sl No. Ingredients % by weight 1 A cinnamic acid esters active fraction 0.001 to 12 2 Glyceryl mono stearate 0.55 3 Cetyl alcohol 0.80 4 Cetostearyl alcohol 0.50 5 Heavy liquid paraffin 2.80 6 Silicone oil 1.00 7 Sorbitan stearate 0.68 8 Isostearic acid 2.20 9 Polysorbate 60 0.50 10 Acrylates copolymer 3.50 11 Sodium hydroxide 0.14 12 Glycerin 3.00 13 Titanium dioxide 0.55 14 Methyl paraben 0.20 15 Propyl paraben 0.10 16 DM water qs to 100 SPF: 20.18 Analysed by in vitro method using SPF 290S analyzer EXAMPLE 5 Sun Protection Cream Sl. No. Name of Ingredients % by weight 1. A cinnamic acid esters active fraction 0.001 to 8 2. Glyceryl monostearate 0.250 3. Stearic acid 6.50 4. Light liquid paraffin 5.50 5. Isopropyl myristate 1.50 6. Cetyl alcohol 1.20 7. Cresmer 1000 0.80 8. Cetostearyl alcohol 1.20 9. Brii 36 0.60 10. Methyl paraben 0.20 11. Propyl paraben 0.10 12. Glycerin 5.00 13. Triethanol amine 0.80 14. Fragrance qs 15. DM Water qs to 100 SPF: 19. 50 Analysed by in vitro method using SPF 290S analyser EXAMPLE 6 Sun Protection Shampoo Sl. No. Name of Ingredients % by weight 1. A cinnamic acid esters active fraction 0.001 to 8 2. Sodium lauryl ether sulphate 40 3. Cocodiethanolamide 1.00 4. Betaine 5.00 5. Sodium chloride 1.00 6. Silicone emulsion 0.50 7. Methyl paraben 0.20 8. Propyl paraben 0.10 9. Fragrance Qs 10. Colour Qs 11. DM Water Qs to 100 SPF: 19.20 Analysed by in vitro method using SPF 290S analyser EXAMPLE 7 Sun Protection Gel Sl. No. Name of the Ingredient % by weight 1. A cinnamic acid ester active fraction 0.001 to 8 2. Sodium lauryl ether sulphate 35.00 3. Carbomer 1.20 4. Betaine 5.00 5. Triethanol amine 0.80 6. Silicone emulsion 0.50 7. Glycerin 5.00 8. Methyl paraben 0.20 9. Propyl paraben 0.10 10. Fragrance Qs 11. DM Water Qs to 100 SPF: 20.12 Analysed by in vitro method using SPF 290S analyzer Primary Skin Irritation Test of Sun Screen Lotion in Guinea Pigs Primary skin irritation is a localized reversible dermal response resulting from a single application of the test substance without the involvement of the immune system. The skin irritation tests are usually carried out on guinea pigs or rabbits. The study is conducted using a covered patch/open application with or with out test substance. The skin reactions are observed at 24, 48 and 72 hours. This test is designed to detect the irritancy potential of the substance under investigation. Ten healthy Guinea pigs of Dunkin Hartley strain weighing from 425-500 g, bred in Experimental Animal Facility of R&D Center, The Himalaya Drug Company, were used for the study. The animals were randomized and divided into two groups of five each. The animals were maintained at 22±3° C., 50-60% of humidity, 12 hours light and dark cycle, with unlimited supply of drinking water and feed. The animals were housed individually in a cage. The fur on the dorsal area of the trunk of the animals selected for the study was removed by clipping or shaving. Care was taken to avoid abrading of the skin. The remaining fur on each guinea pig's back was further removed by a depilatory cream containing thioglycollic acid and, then, the depilatory cream was washed and completely removed from the back of each of the guinea pigs. The guinea pigs were tested 24 hours after the depilatory treatment. All the guinea pigs were weighed prior to the start of test. Each guinea pig treated was immobilized in an animal holder and 0.05 ml of the test substance was applied on a portion (having a size 2×2 cm2) of the back of the guinea pig. Control animals received vehicle treatment. The skin irritation was examined at 24, 48 and 72 hours after the application. The skin reactions were assessed as described below. The assessment of skin irritation was done based on a graded scale of 0 to 4; with no erythema as 0; very slight erythema (barely perceptible) as 1; well defined erythema as 2; moderate to severe erythema as 3 and severe erythema (beet redness) to eschar formation (preventing grading of erythema) as 4. The assessment of edema formation was done based on a graded scale of 0 to 4; with no edema as 0; Very slight edema (barely perceptible) as 1; Slight edema (edges of area well defined by definite raising) as 2; Moderate edema (raised approximately 1 mm) as 3 and Severe edema (raised more than 1 mm and extending beyond area of exposure) as 4. Group-I animals were given vehicle treatment and served as control. Animals from Group II received single topical application of Sunscreen Screen Lotion at a dose of 0.05 ml. The dermal irritancy scores were recorded at 24, 48 and 72 hours after removal of the patch. All the values are expressed as Mean±SEM. The data were analyzed statistically using Student's t-test. The minimum level of significance was fixed at p<0.05. Single application of Sunscreen Screen Lotion in guinea pigs showed no signs and symptoms of skin irritation (Table 1). TABLE 1 Primary Skin Irritation Test of Sun Screen Lotion Skin reactions Erythema (Hours) Edema (Hours) Treatment 24 48 72 24 48 72 Control 0.00 ± 0.00 ± 0.00 ± 0.00 ± 0.00 ± 0.00 ± 0.00 0.00 0.00 0.00 0.00 0.00 Sunscreen 0.00 ± 0.00 ± 0.00 ± 0.00 ± 0.00 ± 0.00 ± Screen 0.00 0.00 0.00 0.00 0.00 0.00 Lotion (0.05 ml/animal) The above findings indicate that Sun Screen Lotion is devoid of skin irritation following acute exposure to guinea pigs. Acute Dermal Photo Irritation Test of Sun Screen Lotion in Guinea Pigs Photoirritation test serves to indicate the existence of possible hazards likely to arise from topical application to skin of the test substance in association with exposure to light. Clinically it is characterized by skin changes showing erythema or oedema or both. Photoirritation potential may be examined by using guinea pigs. Photoirritation test is carried out by applying the test substance topically at appropriate concentration on the skin, which is then exposed to UV light. Skin reactions are assessed at 24, 48 and 72 hours. Albino Guinea pigs of Dunkin Hartley strain bred in Experimental Animal Facility of R&D Center, The Himalaya Drug Company, were used for the study. Five animals weighing between 450-600 g were used for the study. The animals were maintained at 22±3° C., 50-60% of humidity, 12 hours light and dark cycle, with unlimited supply of drinking water and feed. The animals were housed individually in a cage. Sun Screen Lotion was applied topically without any dilution at a dose of 0.025 ml/animal. The fur on the dorsal area of the trunk of the animals selected for the study was removed by clipping or shaving. Care will be taken to avoid abrading of the skin. The remaining fur on each guinea pig's back was further removed by a depilatory cream containing thioglycollic acid and, then, the depilatory cream was washed and completely removed from the back of each of the guinea pigs. The guinea pigs were tested 24 hours after the depilatory treatment. Two areas of 2.5 cm×2.5 cm on the dorsal side (one in the left and other in the right) of the animal were marked using black marker. All the guinea pigs were weighed prior to the start of each test and the weights are recorded. The marked area in the left side served as irradiation irritation control site (IICS) and the right side received topical application of Sun Screen Lotion to serve as test. The rest of the surrounding area covered with a flank to serve as UV protected control. The animals are exposed to radiation 30 minutes after the application of the test substance. Prior to irradiation, the head of the animal is protected to avoid ocular effects. The animals were kept in a top open polypropylene cage, one at a time. All the animals were irradiated with a 300 watts Wotan Ultra Vitalux lamp for 10 minutes at a distance of 25 cm (between the lamp and the dorsal aspect of the animal). Each test site was examined at 24, 48 and 72 hours after the start of the irradiation. The responses are scored blindly under a constant artificial light source according to the following grading scale and entered in the assessment record sheet. The assessment of skin reactions following UV-irradiation were done for erythema on a graded scale of 0 to 4; with no erythema as 0; very slight erythema (barely perceptible) as 1; well defined erythema as 2; moderate to severe erythema as 3 and severe erythema (beet redness) to eschar formation (preventing grading of erythema) as 4. The assessment of skin reactions following UV-irradiation were done for edema on a graded scale of 0 to 4; with no edema as 0; Very slight edema (barely perceptible) as 1; Slight edema (edges of area well defined by definite raising) as 2; Moderate edema (raised approximately 1 mm) as 3 and Severe edema (raised more than 1 mm and extending beyond area of exposure) as 4. Exposure to UV-irradiation in Irradiation Irritation Control Site showed mild photo irritation at 24 and 48 hours post irradiation. UV-irradiation of animals following topical application of Sun Screen Lotion at a dose of 0.025 ml/animal showed no positive reactions of photo irritation (Table 2). TABLE 2 Acute Dermal Photo irritation Test of Sun Screen Lotion Skin reactions Erythema (Hours) Edema (Hours) Treatment 24 48 72 24 48 72 Control 1.00 ± 1.00 ± 0.00 ± 0.00 ± 0.00 ± 0.00 ± (Irradiation 0.45 0.45 0.00 0.00 0.00 0.00 Irritation Control Site) Sun Screen 0.00 ± 0.00 ± 0.00 ± 0.00 ± 0.00 ± 0.00 ± Lotion (0.05 0.00 0.00 0.00 0.00 0.00 0.00 ml/animal) The above findings indicate that Sun Screen Lotion is free of photo irritation and it can be safely used in association with exposure to light. While this invention has been described in detail with reference to certain preferred embodiments, it should be appreciated that the present invention is not limited to those precise embodiments. Rather, in view of the present disclosure, which describes the current best mode for practicing the invention, many modifications and variations would present themselves to those skilled in the art without departing from the scope and spirit of this invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention, in general, relates to cosmetic compositions. More specifically, this invention relates to natural sunscreen compositions and processes for producing the same. 2. Description of the Related Art Human skin is sensitive to solar rays and overexposure to sun can cause not only simple sunburn or an erythema, but also burns of varying severity. The other negative effects of over-exposure to solar rays are, tanning, immune suppression, photosensitivity or drug related photosensitivity and photo allergies. Sun can also cause the skin to lose its elasticity and form wrinkles, leading to premature ageing. Dermatosis may also be caused due to over-exposure to solar rays. In extreme cases, some people can develop skin cancer. Outdoor activities including typical field-related jobs and sporting activities expose the skin to sun. It has been estimated that nearly 75 percent of the sun-inflicted skin damage on the average person's skin over a lifetime is the result of being just outdoors. Hence we require a protection so that we can expose ourselves to the sunlight without getting harmed. These concerns have been heightened by evidence that the earth's ozone layer has suffered severe depletion in recent years. Ozone is recognized as the stratospheric component shielding against the harmful forms of ultraviolet radiation. But still 5% of the sunrays coming to the earth are composed of the ultraviolet rays. These ultraviolet rays are composed of the shorter-wavelength (290-320 nm) UVB rays that cause indirect sun tanning and the longer-wavelength (320-400 nm) UVA rays that are responsible for direct sun tanning. Sunscreen compositions offer a scientific solution to the above-identified harmful effects of over-exposure to the ultraviolet rays. Topical application sunscreen formulations are known. Sunscreen active are generally classified as organic sun screeners or inorganic sun screeners. Organic sun screeners absorb strongly at specific wavelengths and are transparent to visible light. However, some organic sun screeners such as Oxybenzone are known to cause photo allergic reactions. Inorganic sun screeners such as Titanium dioxide at higher levels leave visible residue referred as whitening of the skin. To overcome these allergic side effects of organic sun screeners and non-aesthetics of inorganic sun screeners, there exist the need for devising newer formulations, that can protect the skin from the harmful effects of the ultraviolet radiations of sun without any undesirable side effects. It is against this background the present invention has been brought out. U.S. Pat. No. 6,500,869 to Driller et al. discloses a sun protection formulation in solid or liquid form containing organic or inorganic sunscreen filters for a prophylactic action. Disclosed in this patent are substances of cinnamic acid derivatives, in particular octyl p-methoxycinnamate that function not only as light protection filters, but also as solvents for other UV filters and are therefore often used in combination with various filters. U.S. Pat. No. 6,537,529 to Bonda et al. discloses a method of preparing a sunscreen including a solvent system and a filter system, as well as sunscreen compositions and compounds for producing sunscreen compositions. U.S. Pat. No. 5,773,014 to Perrier et al. discloses a composition to inhibit the formation of unwanted skin pigmentation. The active components of the composition include extracts of selected plants, namely, mulberry, saxifrage, grape and scutellaria root; and, preferably, ethylene diamine tetra acetic acid (EDTA). U.S. Pat. No. 6,440,402 to Gonzalez et al. discloses the synergistic action of Kaempferia galanga root extract in sunscreen formulation. The invention also discloses a method comprising introducing into the composition an amount of extract of Kaempferia galanga plant sufficient to enhance the photostability of the sunscreen active. U.S. Pat. No. 5,756,099 to Simpson et al. discloses a process of preparing natural, organic, topical tanning sunscreen compositions comprising extracting the embryonic, spongy mass of tissue of the coconut from the drupe and adding it to the flesh of papaya in a proportional ratio of 1:3. Sunscreen compositions comprising herbal extracts that can act as antioxidants are known in prior art. Sunscreen compositions containing herbal extracts such as green tea, aloe vera, calendula, chamomile rosemary are also known in the art. Further, it is known in the art to devise sunscreen compositions having cinnamic acid esters, wherein the cinnamic acid esters act as sunscreen actives. The present invention is distinct from the above prior art compositions as described hereunder. | <SOH> SUMMARY OF THE INVENTION <EOH>In one preferred embodiment, there is provided a safe and effective natural sunscreen composition comprising extract of plant Hedychium spicatum and plant Alpinia galanga and a cosmetically acceptable carrier. In another preferred embodiment, there is provided a safe and effective natural sunscreen composition comprising extract of plant Hedychium spicatum or plant Alpinia galanga and a cosmetically acceptable carrier. In yet another preferred embodiment, there is provided a safe and effective natural sunscreen composition comprising cinnamic acid esters, individually or mixtures thereof, isolated and characterized from the extract of plant Hedychium spicatum and a cosmetically acceptable carrier. In still another preferred embodiment, there is provided a safe and effective natural sunscreen composition comprising cinnamic acid esters, individually or mixtures thereof, isolated and characterized from the extract of plant Alpinia galanga and a cosmetically acceptable carrier. In one another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises Hedychium spicatum extract (0.001% to 20%), Glyceryl mono stearate (0.55%), Cetyl alcohol (0.80%), Cetostearyl alcohol (0.50%), Heavy liquid paraffin (2.80%), Silicone oil (1.00%), Sorbitan stearate (0.68%), Isostearic acid (2.20%), Polysorbate 60 (0.50%), Acrylates copolymer (3.50%), Sodium hydroxide (0.14%), Glycerin (3.00%), Titanium dioxide (0.55%), Methyl paraben (0.20%) and Propyl paraben (0.10%) and demineralized water. In a preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises Alpinia galanga extract (0.001% to 20%), Glyceryl mono stearate (0.55%), Cetyl alcohol (0.80%), Cetostearyl alcohol (0.50%), Heavy liquid paraffin (2.80%), Silicone oil (1.00%), Sorbitan stearate (0.68%), Isostearic acid (2.20%), Polysorbate 60 (0.50%), Acrylates copolymer (3.50%), Sodium hydroxide (0.14%), Glycerin (3.00%), Titanium dioxide (0.55%), Methyl paraben (0.20%), Propyl paraben (0.10%), and demineralized water. In still another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 8%), Glyceryl mono stearate (0.55%), Cetyl alcohol (0.80%), Cetostearyl alcohol (0.50%), Heavy liquid paraffin (2.80%), Silicone oil (1.00%), Sorbitan stearate (0.68%), Isostearic acid (2.20%), Polysorbate 60 (0.50%), Acrylates copolymer (3.50%), Sodium hydroxide (0.14%), Glycerin (3.00%), Titanium dioxide (0.55%), Methyl paraben (0.20%) and Propyl paraben (0.10%), and demineralized water. In yet another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 12%), Glyceryl mono stearate (0.55%), Cetyl alcohol (0.80%), Cetostearyl alcohol (0.50%), Heavy liquid paraffin (2.80%), Silicone oil (1.00%), Sorbitan stearate (0.68%), Isostearic acid (2.20%), Polysorbate 60 (0.50%), Acrylates copolymer (3.50%), Sodium hydroxide (0.14%), Glycerin (3.00%), Titanium dioxide (0.55%), Methyl paraben (0.20%) and Propyl paraben (0.10%), and demineralized water. In yet another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 8%), Glyceryl mono stearate (0.250%), Stearic acid (6.50%), Light liquid paraffin (5.50%), Isopropyl myristate (1.50%), Cetyl alcohol (1.20%), Cresmer 1000 (0.80%), Cetostearyl alcohol (1.20%), Brii 36 (0.60%), Methyl paraben (0.20%), Propyl paraben (0.10%), Glycerin (5.00%), Triethanol amine (0.80%), Fragrance (qs) and DM Water (qs to 100). In yet another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 8%), Sodium lauryl ether sulphate (40%), Cocodiethanolamide (1.00%), Betaine (5.00%), Sodium chloride (1.00%), Silicone emulsion (0.50%), Methyl paraben (0.20%), Propyl paraben (0.10%), Fragrance (qs), Colour (qs) and DM Water (qs to 100). In yet another preferred embodiment, the present invention provides for a safe and effective natural sunscreen composition, wherein the composition comprises cinnamic acid esters (0.001% to 8%), Sodium lauryl ether sulphate (35.00%), Carbomer (1.20%), Betaine (5.00%), Triethanol amine (0.80%), Silicone emulsion (0.50%), Glycerin (5.00%), Methyl paraben (0.20%), Propyl paraben (0.10%), Fragrance (qs) and DM Water (qs to 100). It is an aspect of the present invention to provide for a method of producing a natural sunscreen composition, the method comprising extracting plant extracts from Hedychium spicatum by percolation, filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and producing a natural sunscreen composition employing the said dried mass and a cosmetically acceptable carrier. In still another aspect, the present invention provides for a method for producing a natural sunscreen composition, the method comprising extracting plant extracts from Hedychium spicatum by hot-soxhalation, filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and producing a natural sunscreen composition employing the said dried mass and a cosmetically acceptable carrier. It is an aspect of the present invention to provide for a method for producing a natural sunscreen composition, the method comprising extracting plant extracts from Alpinia galanga by percolation, filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and producing a natural sunscreen composition employing the said dried mass and a cosmetically acceptable carrier. In still another aspect, the invention provides for a method for producing a natural sunscreen composition, the method comprising extracting plant extracts from Alpinia galanga by hot-soxhalation, filtering the plant extract, concentrating the plant extract to dryness on a rotatory evaporator under vacuum at optimum temperature and producing a natural sunscreen composition employing the said dried mass and a cosmetically acceptable carrier. In yet another aspect, the invention provides for a method for producing a natural sunscreen composition, the method comprising extracting extracts of plant Hedychium spicatum or Alpinia galanga by percolation or hot-soxhalation, filtering the plant extract, purifying the extract by crystallization to obtain pure cinnamic acid esters and producing a natural sunscreen composition employing the pure cinnamic acid esters thus obtained and a cosmetically acceptable carrier. In yet another aspect, the invention provides for a method for producing a natural sunscreen composition, the method comprising extracting plant extracts from Hedychium spicatum or Alpinia galanga by solvent extraction using an organic solvent selected from the group comprising petroleum ether, hexane, cyclohexane, benzene, dichloromethane, chloroform, ethyl acetate, acetone, methanol and ethanol, either alone or in combination thereof, purifying the resultant extract; separating the pure compound; characterizing the compound as cinnamic acid esters and producing the natural sunscreen composition using the cinnamic acid esters thus produced and a cosmetically acceptable carrier. In yet another preferred embodiment, the present invention provides for a delivery system containing a natural sunscreen composition comprising extract of plant Hedychium spicatum and plant Alpinia galanga and a cosmetically acceptable carrier. In still another preferred embodiment, the present invention provides for a delivery system containing a natural sunscreen composition comprising extract of plant Hedychium spicatum and plant Alpinia galanga and a cosmetically acceptable carrier wherein the delivery system includes creams, shampoos, gels, lotions, soaps, oils, sticks or sprays. detailed-description description="Detailed Description" end="lead"? | 20040205 | 20071225 | 20050811 | 72654.0 | 0 | DODSON, SHELLEY A | NATURAL SUNSCREEN COMPOSITIONS AND PROCESSES FOR PRODUCING THE SAME | SMALL | 0 | ACCEPTED | 2,004 |
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10,773,105 | ACCEPTED | Molten metal pump components | Improved components for a molten metal pump include a coupling for connecting a rotor shaft to a motor shaft, a rotor shaft and a rotor. The rotor shaft has a first end and a second end wherein the first end optionally has a vertical keyway formed in the outer surface of the shaft. The second end optionally has flat, shallow threads. The coupling can be one-piece or multi-piece, includes a cavity for receiving the first end of the rotor shaft and, if the first end of the rotor shaft has a keyway, the coupling includes a projection in the cavity for being received at least partially in the keyway. The rotor includes a connective portion that connects to the second end of the rotor shaft. If the second end of the rotor shaft includes flat, shallow threads, the connective portion is essentially a bore having flat, shallow threads configured to receive the second end of the rotor shaft. Optionally, the first end of the rotor shaft may have flat, shallow threads in which case the coupling would have a cavity that receives the first end of the rotor shaft, wherein the cavity has flat, shallow threads. | 1. A molten metal pump comprising: a motor; a drive shaft comprising a motor shaft coupled to a rotor shaft, the rotor shaft having a first end and a second end wherein the first end has an outer surface and a keyway formed in the outer surface, and the second end has flat, shallow threads; a coupling having a first coupling member for coupling to the motor shaft and a second coupling member for connecting to the rotor shaft, the second coupling member having a projection that is received in the keyway; a pump base having a pump chamber and a discharge; and a rotor positioned at least partially in the pump chamber including a connective portion having flat, shallow threads, the second end of the rotor shaft received in the connective portion 2. The pump according to claim 1 wherein the rotor shaft is comprised of graphite. 3. The pump according to claim 1 wherein the coupling is comprised of steel. 4. The pump according to claim 1 wherein the pump is a gas-release pump and includes a gas-release conduit attached to the discharge. 5. The pump according to claim 1 wherein the pump is a gas-release pump and includes a metal-transfer conduit attached to the discharge and a gas-release conduit attached to the metal-transfer conduit. 6. A pump according to claim 1 wherein the pump is a transfer pump and includes a metal-transfer conduit attached to the discharge. 7. The pump according to claim 1 wherein the projection is substantially the same length as the keyway. 8. A rotor shaft for use in a molten metal pump, the rotor shaft having an outer surface, a first end for connecting to a coupling and a second end for connecting to a rotor wherein the first end includes a vertically-extending keyway formed on the outer surface, the keyway for receiving a projection whereby the projection can apply driving force to the rotor shaft. 9. The rotor shaft of claim 8 that is comprised of graphite. 10. The rotor shaft of claim 8 wherein the outer surface is annular. 11. The rotor shaft of claim 8 wherein the first end does not include threads. 12. The rotor shaft of claim 8 wherein the keyway has a depth of ⅜ and a length of 3″-4″. 13. The rotor shaft of claim 8 wherein the keyway is formed at a 45 degree angle relative the longitudinal axis of the rotor shaft. 14. The rotor shaft of claim 8 wherein the second end includes flat, shallow threads. 15. The rotor shaft of claim 8 that further includes a ceramic sleeve. 16. A coupling for use in a molten metal pump, the pump comprising a motor shaft and a rotor shaft, the coupling comprising a first end for connecting to the motor shaft and a second end for connecting to the rotor shaft, the second end including a longitudinally-extending projection to be at least partially received in a keyway of the rotor shaft. 17. The coupling of claim 16 wherein the second end of the coupling does not include threads. 18. The coupling of claim 16 wherein the second end of the coupling comprises a cylindrical opening having an inner surface, wherein the projection is positioned on the inner surface. 19. The coupling of claim 16 that is comprised of steel. 20. The coupling of claim 16 that further includes apertures for receiving a bolt. 21. A rotor for use in a molten metal pump, the rotor having a connective portion for connecting to an end of a rotor shaft having flat, shallow threads, the connective portion having flat, shallow threads configured to receive the flat, shallow threads of the end of the rotor shaft. 22. The rotor of claim 21 that is comprised of graphite. 23. The rotor of claim 21 that is trilobal. 24. The rotor of claim 21 that is a device including an inlet structure and a displacement structure for displacing molten metal, whereby the inlet structure and displacement structure rotate as the rotor rotates. 25. A rotor shaft for use in a molten metal pump, the rotor shaft having a first end for being received in a coupling, the first end having flat, shallow threads. 26. The rotor shaft of claim 25 that further comprises a second end having flat, shallow threads, the second end for attaching to a connective portion of a rotor. 27. The rotor shaft of claim 25 wherein the second end includes a taper for centering the shaft in the bore. 28. A rotor shaft for use in a molten metal pump, the rotor shaft having a first end for being received in a coupling and a second end for connecting to a rotor, the first end including keyway means for receiving driving force from the coupling. 29. The rotor shaft of claim 28 wherein the second end includes connection means for connecting the rotor shaft to the rotor. 30. The rotor shaft of claim 28 wherein the rotor shaft has an outer surface and the keyway means is a vertical keyway formed in the outer surface of the rotor shaft. 31. The rotor shaft of claim 30 wherein the keyway means has a length of about 3″. 32. The rotor shaft of claim 30 wherein the keyway means is formed parallel to the longitudinal axis of the rotor shaft. 33. A rotor shaft for use in a molten metal pump, the rotor shaft having a first end for connecting to a coupling and a second end including thread means for connecting to a connective portion of a rotor and capable of applying at least some drawing force to the rotor. 34. The rotor shaft of claim 33 wherein the thread means comprise threads that are not pointed. 35. The rotor shaft of claim 33 wherein the thread means comprise threads that are not tapered. 36. the rotor shaft of claim 33 wherein the thread means comprise threads that are about 0.495″ wide and 0.100″ deep. 37. The rotor shaft of claim 33 wherein the second end is tapered. | FIELD OF THE INVENTION The invention relates to components used in molten metal pumps, particularly a rotor shaft, a rotor shaft coupling and a connective portion on a rotor to connect to a rotor shaft. The components are designed to facilitate connections while alleviating breakage of the components. BACKGROUND OF THE INVENTION As used herein, the term “molten metal” means any metal or combination of metals in liquid form, such as aluminum, copper, iron, zinc and alloys thereof. The term “gas” means any gas or combination of gases, including argon, nitrogen, chlorine, fluorine, freon, and helium, which are released into molten metal. Known pumps for pumping molten metal (also called “molten-metal pumps”) include a pump base (also called a housing or casing), one or more inlets to allow molten metal to enter a pump chamber (an inlet is usually an opening in the pump base that communicates with the pump chamber), a pump chamber, which is an open area formed within the pump base, and a discharge, which is a channel or conduit communicating with the pump chamber (in an axial pump the pump chamber and discharge may be the same structure or different areas of the same structure) leading from the pump chamber to the molten metal bath in which the pump base is submerged. A rotor, also called an impeller, is mounted in the pump chamber and is connected to a drive shaft. The drive shaft is typically a motor shaft coupled to a rotor shaft, wherein the motor shaft has two ends, one end being connected to a motor and the other end being coupled to the rotor shaft. The rotor shaft also has two ends, wherein one end is coupled to the motor shaft and the other end is connected to the rotor. Often, the rotor shaft is comprised of graphite, the motor shaft is comprised of steel, and these two shafts are coupled by a coupling, which is usually comprised of steel. As the motor turns the drive shaft, the drive shaft turns the rotor and the rotor pushes molten metal out of the pump chamber, through the discharge, which may be an axial or tangential discharge, and into the molten metal bath. Most molten metal pumps are gravity fed, wherein gravity forces molten metal through the inlet and into the pump chamber as the rotor pushes molten metal out of the pump chamber. Molten metal pump casings and rotors usually employ a bearing system comprising ceramic rings wherein there are one or more rings on the rotor that align with rings in the pump chamber (such as rings at the inlet (which is usually the top of the pump chamber and bottom of the pump chamber) when the rotor is placed in the pump chamber. The purpose of the bearing system is to reduce damage to the soft, graphite components, particularly the rotor and pump chamber wall, during pump operation. A known bearing system is described in U.S. Pat. No. 5,203,681 to Cooper, the disclosure of which is incorporated herein by reference. As discussed in U.S. Pat. Nos. 5,591,243 and 6,093,000, each to Cooper, the disclosures of which are incorporated herein by reference, bearing rings can cause various operational and shipping problems and U.S. Pat. No. 6,093,000 discloses rigid coupling designs and a monolithic rotor to help alleviate this problem. Further, U.S. Pat. No. 2,948,524 to Sweeney et al., U.S. Pat. No. 4,169,584 to Mangalick, U.S. Pat. No. 5,203,681 to Cooper and U.S. Pat. No. 6,123,523 to Cooper (the disclosures of the afore-mentioned patents to Cooper, insofar as such disclosures are not inconsistent with the teachings of this application, are incorporated herein by reference) all disclose molten metal pumps. Furthermore, copending U.S. patent application Ser. No. ______ to Paul V. Cooper, filed on Feb. 4, 2004 and entitled “Pump With Rotating Inlet” discloses, among other things, a pump having an inlet and rotor structure (or other displacement structure) that rotate together as the pump operates in order to alleviate jamming. The disclosure of this copending application, insofar as such disclosures are not inconsistent with the teachings of this application, is incorporated herein by reference. The materials forming the components that contact the molten metal bath should remain relatively stable in the bath. Structural refractory materials, such as graphite or ceramics, that are resistant to disintegration by corrosive attack from the molten metal may be used. As used herein “ceramics” or “ceramic” refers to any oxidized metal (including silicon) or carbon-based material, excluding graphite, capable of being used in the environment of a molten metal bath. “Graphite” means any type of graphite, whether or not chemically treated. Graphite is particularly suitable for being formed into pump components because it is (a) soft and relatively easy to machine, (b) not as brittle as ceramics and less prone to breakage, and (c) less expensive than ceramics. Three basic types of pumps for pumping molten metal, such as molten aluminum, are utilized: circulation pumps, transfer pumps and gas-release pumps. Circulation pumps are used to circulate the molten metal within a bath, thereby generally equalizing the temperature of the molten metal. Most often, circulation pumps are used in a reverbatory furnace having an external well. The well is usually an extension of a charging well where scrap metal is charged (i.e., added). Transfer pumps are generally used to transfer molten metal from the external well of a reverbatory furnace to a different location such as a ladle or another furnace. Examples of transfer pumps are disclosed in U.S. Pat. No. 6,345,964 B1 to Cooper, the disclosure of which, insofar as such disclosures are not inconsistent with the teachings of this application, is incorporated herein by reference, and U.S. Pat. No. 5,203,68 1. Gas-release pumps, such as gas-injection pumps, circulate molten metal while releasing a gas into the molten metal. In the purification of molten metals, particularly aluminum, it is frequently desired to remove dissolved gases such as hydrogen, or dissolved metals, such as magnesium, from the molten metal. As is known by those skilled in the art, the removing of dissolved gas is known as “degassing” while the removal of magnesium is known as “demagging.” Gas-release pumps may be used for either of these purposes or for any other application for which it is desirable to introduce gas into molten metal. Gas-release pumps generally include a gas-transfer conduit having a first end that is connected to a gas source and a second submerged in the molten metal bath. Gas is introduced into the first end and is released from the second end into the molten metal. The gas may be released downstream of the pump chamber into either the pump discharge or a metal-transfer conduit extending from the discharge, or into a stream of molten metal exiting either the discharge or the metal-transfer conduit. Alternatively, gas may be released into the pump chamber or upstream of the pump chamber at a position where it enters the pump chamber. A system for releasing gas into a pump chamber is disclosed in U.S. Pat. No. 6,123,523 to Cooper. Another gas-release pump is disclosed in a co-pending U.S. Patent application filed on Feb. 4, 2004 and entitled “System for Releasing Gas Into Molten Metal” to Paul V. Cooper, the disclosure of which that is not inconsistent with the teachings of this application is incorporated herein by reference. A problem with known molten metal pumps is that machining the graphite components, such as the rotor and rotor shaft, can create weak points that may break during operation. For example, it is known to machine threads into an end of a rotor shaft in order for the end to be received in the threaded bore of a coupling so that the coupling (connected to a motor shaft at the end opposite the rotor shaft) can drive the rotor shaft. The threads formed in the end of the rotor shaft are typically pointed and create weak areas that can cause the rotor shaft to break during operation. A similar type of threaded connection is often used to connect the rotor shaft to the rotor. Further, it is known to machine an end of the rotor shaft to create opposing flat surfaces that are received in the coupling. Removing this material from the end of the rotor shaft also weakens the shaft and can cause breakage. SUMMARY OF THE INVENTION The present invention includes improved rotor shafts, and a coupling and rotor that can be used with one or more of the improved rotor shafts. One rotor shaft according to the invention has a first end for connecting to a coupling and a second end for connecting to a rotor. The first end has an outer surface, preferably having a generally annular outer wall, and a vertical keyway formed in the outer surface. The first end is received in a cavity of a coupling wherein the cavity includes a projection that is received at least partially in the keyway and the projection applies driving force to the rotor shaft as the coupling turns. Another rotor shaft according to the invention has a second end including flat, shallow threads, rather than threads that end in a point (also referred to herein as “pointed threads”). This shaft is used with a rotor having a connective portion, wherein the connective portion is a bore that also includes flat, shallow threads and the second end of the rotor shaft is received in the connective portion. A rotor shaft according to the invention may also have both a first end and a second end as described above. Further, a rotor shaft according to the invention may have a first end with shallow, flat threads that is used with a coupling having shallow, flat threads to receive the first end. Also disclosed herein are a coupling and rotor that may be used with one or more rotor shafts according to the invention and pumps including one or more of the improved components. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a pump for pumping molten metal. FIG. 1a is a perspective view of the pump base of the pump of FIG. 1. FIG. 2 is a side view of a rotor shaft according to the invention. FIG. 3 is a perspective view of one end of the rotor shaft of FIG. 2 showing a keyway. FIG. 4 is side view of the end of the rotor shaft shown in FIG. 3. FIG. 5 is a side view of the end of the rotor shaft shown in FIGS. 3 and 4, wherein the rotor shaft has been rotated to show a through bolt hole. FIG. 6 is a side view of the end of the rotor shaft shown in FIG. 2, wherein the end is opposite the end shown in FIGS. 3-5. FIG. 7 is a side view of a coupling according to the invention. FIG. 8 is a bottom, perspective view of the coupling of FIG. 7 as seen from the vantage of arrow A on FIG. 7. FIG. 9 is a close up view of the coupling of FIG. 8. FIG. 10 is a device that may be used as a rotor in the practice of the invention. FIG. 11 is a cross-sectional view of the device of FIG. 10 taken along line B-B. FIG. 12 is a partial, perspective view of the cross-section of FIG. 11. FIG. 13 is a partial, top view of the cross-section of FIG. 11. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing where the purpose is to illustrate and describe different embodiments of the invention, and not to limit same, FIG. 1 shows a molten metal pump. During operation, Pump 20 is usually positioned in a molten metal bath B in a pump well, which is normally part of the open well of a reverbatory furnace. The components of pump 20 that are exposed to the molten metal are preferably formed of structural refractory materials, which are resistant to degradation in the molten metal. Carbonaceous refractory materials, such as carbon of a dense or structural type, including graphite, graphitized carbon, clay-bonded graphite, carbon-bonded graphite, or the like have all been found to be most suitable because of cost and ease of machining. Such components may be made by mixing ground graphite with a fine clay binder, forming the non-coated component and baking, and may be glazed or unglazed. In addition, components made of carbonaceous refractory materials may be treated with one or more chemicals to make the components more resistant to oxidation. Oxidation and erosion treatments for graphite parts are practiced commercially, and graphite so treated can be obtained from sources known to those skilled in the art. Pump 20 can be any structure or device for pumping or otherwise conveying molten metal, such as one of the pumps disclosed in U.S. Pat. No. 5,203,681 to Cooper, copending U.S. Patent Application to Cooper entitled “Pump with Rotating Inlet” or copending U.S. Patent Application to Cooper entitled “System for Releasing Gas Into Molten Metal.” The invention could also use an axial pump having an axial, rather than tangential, discharge. Preferred pump 20 has a pump base 24 for being submersed in a molten metal bath. Pump base 24 preferably includes a generally nonvolute pump chamber 26, such as a cylindrical pump chamber or what has been called a “cut” volute, although pump base 24 may have any shape pump chamber suitable of being used, including a volute-shaped chamber. Chamber 26 may be constructed to have only one opening, either in its top or bottom, if a tangential discharge is used, since only one opening is required to introduce molten metal into pump chamber 26. Generally, pump chamber 24 has two coaxial openings of the same diameter and usually one is blocked by a flow blocking plate mounted on the bottom of, or formed as part of, a device or rotor 100. (In the context of this application, “rotor” refers to any rotor that may be used to displace molten metal, and includes a device having a rotating inlet structure). As shown in FIG. 1a, chamber 26 includes a top opening 28, bottom opening 29, and wall 31. Base 24 further includes a tangential discharge 30 (although another type of discharge, such as an axial discharge may be used) in fluid communication with chamber 26. Base 24 has sides 112, 114, 116, 118 and 120 and atop surface 110. The top portion of wall 31 is machined to receive a bearing surface, which is not yet mounted to wall 31 in this figure. The bearing surface is typically comprised of ceramic and cemented to wall 31. One or more support posts 34 connect base 24 to a superstructure 36 of pump 20 thus supporting superstructure 36, although any structure or structures capable of supporting superstructure 36 may be used. Additionally, pump 20 could be constructed so there is no physical connection between the base and the superstructure, wherein the superstructure is independently supported. The motor, drive shaft and rotor could be suspended without a superstructure, wherein they are supported, directly or indirectly, to a structure independent of the pump base. In the preferred embodiment, post clamps 35 secure posts 34 to superstructure 36. A preferred post clamp and preferred support posts are disclosed in a copending application entitled “Support Post System For Molten Metal Pump,” invented by Paul V. Cooper, and filed on Feb. 4, 2004, the disclosure of which is incorporated herein by reference. However, any system or device for securing posts to superstructure 36 may be used. A motor 40, which can be any structure, system or device suitable for driving pump 20, but is preferably an electric or pneumatic motor, is positioned on superstructure 36 and is connected to an end of a drive shaft 42. A drive shaft 42 can be any structure suitable for rotating an impeller, and preferably comprises a motor shaft (not shown) coupled to a rotor shaft. The motor shaft has a first end and a second end, wherein the first end of the motor shaft connects to motor 40 and the second end of the motor shaft connects to the coupling. Rotor shaft 44 has a first end and a second end, wherein the first end is connected to the coupling and the second end is connected to device 100 or to an impeller according to the invention. The preferred rotor is device 100 as disclosed in the previously-described copending application entitled “Pump with Rotating Inlet.” Rotor shaft 44, best seen in FIGS. 1-6, has an annular outer surface 46, is preferably comprised of graphite, although any shape, size and material suitable for use in a molten metal pump may be used, has a first end 48 and a second end 50. First end 48 preferably includes a vertically extending keyway 52 suitable for transferring driving force to rotor shaft 44. Keyway 52 is preferably vertical, has a width of about ¾″ and a depth of about ⅜″ and a length of about 4″. Keyway 52 is preferably formed on a milking machine using a ¾″ diameter bit or tool. As used herein with respect to keyway 52, the term “vertical” or “vertically-extending” means any keyway parallel to longitudinal axis Y of shaft 44 or having an angle up to 45 degrees from being parallel with axis Y. Moreover, any width, depth and length keyway may be used that is capable of supplying adequate rotational force to shaft 44. Keyway 52, however, should not have a depth greater than ⅓ the diameter of shaft 44 nor should it have a width greater than about 3″, because keyway 52 should not significantly weaken shaft 44. Shaft 44 may also include multiple keyways, in which case the dimensions of each of the keyways need be sufficient to provide, in the aggregate, adequate driving force to rotor shaft 44. Any rotor shaft described or claimed herein that has “a keyway” refers to a rotor shaft having at least one keyway. A through-bolt hole 53 is included at end 48 of rotor shaft 44. Hole 53 is preferably ½″ in diameter, although any suitable diameter may be used. The purpose of through-bolt hole 53 is to receive a bolt (not shown) that locates rotor shaft 44 in the proper location relative pump base 26 and any suitable structure that provides this function may be used. Rotor shaft 44 has an optional ceramic sleeve 56, which helps to prevent shaft 44 from being broken. Shaft 44 also has a second end 50 that includes shallow, flat threads 54. The preferred threads on shaft 54 (and the preferred threads on rotor 100) preferably have a width W of about 0.495″ and a height X of about 0.100″ and the grooves that receive the threads have a width WI of about 0.505″ and are about 0.005″-0.010″ deeper than the height X of the thread. The threads thus have a spacing of about one thread per inch. The threads preferably are flat, are not tapered outward and second end 50 preferably, but not necessarily, has a tapered portion that helps to properly locate end 50 in connective portion 110 of rotor 100, do not end in a point, which further helps to alleviate breakage. A preferred coupling 200 is made of steel, although any suitable material may be used, has a first coupling member 202 for receiving and being connected to an end of motor shaft 40 and member 202 may be any structure suitable for this purpose, although it is preferred that the connection is made using one or more set screws or bolts (not shown) that are threaded through openings 203. A second coupling member 204 is preferably cylindrical and includes a cavity 206 for receiving first end 48 of rotor shaft 44. Cavity 206 preferably has an annular inner wall 208 and apertures 210 though which a through bolt (not shown) is passed. A projection 212 is preferably steel and is dimensioned to be received at least partially in keyway 52 such that it can provide driving force to rotor shaft 44. In this embodiment, projection 212 is a ¾″ diameter steel rod embedded approximately halfway in to annular wall 206, and is about 3″-4″ in length. Projection 212 may be attached or connected to member 204 in any suitable manner, such as by welding. Projection 212 applies driving force to rotor shaft 44 as coupling 200 turns. Rotor 100, shown in FIGS. 10-13, has a connective portion 110 that includes a threaded bore 112 for receiving end 50. Bore 112 includes flat, shallow threads 112 that mate with threads 54 of end 50. Any rotor design, however, having a suitable connective portion may be utilized. Alternatively, a shaft according to the invention may have a first end including flat, shallow threads for connecting to a coupling. In that case, the coupling would have a cavity for receiving the first end of the rotor shaft wherein the cavity would include flat, shallow threads that would mate with the threads on the first end of the rotor shaft. Moreover, the first end of the rotor shaft may have a keyway and some threads. Alternatively, a shaft according to the invention may have just a first end with flat, shallow threads, just a second end with flat, shallow threads or just a first end with a keyway, or a first end with flat, shallow threads and a second end with flat, shallow threads. Having thus described different embodiments of the invention, other variations and embodiments that do not depart from the spirit of the invention will become apparent to those skilled in the art. The scope of the present invention is thus not limited to any particular embodiment, but is instead set forth in the appended claims and the legal equivalents thereof. Unless expressly stated in the written description or claims, the steps of any method recited in the claims may be performed in any order capable of yielding the desired product. | <SOH> BACKGROUND OF THE INVENTION <EOH>As used herein, the term “molten metal” means any metal or combination of metals in liquid form, such as aluminum, copper, iron, zinc and alloys thereof. The term “gas” means any gas or combination of gases, including argon, nitrogen, chlorine, fluorine, freon, and helium, which are released into molten metal. Known pumps for pumping molten metal (also called “molten-metal pumps”) include a pump base (also called a housing or casing), one or more inlets to allow molten metal to enter a pump chamber (an inlet is usually an opening in the pump base that communicates with the pump chamber), a pump chamber, which is an open area formed within the pump base, and a discharge, which is a channel or conduit communicating with the pump chamber (in an axial pump the pump chamber and discharge may be the same structure or different areas of the same structure) leading from the pump chamber to the molten metal bath in which the pump base is submerged. A rotor, also called an impeller, is mounted in the pump chamber and is connected to a drive shaft. The drive shaft is typically a motor shaft coupled to a rotor shaft, wherein the motor shaft has two ends, one end being connected to a motor and the other end being coupled to the rotor shaft. The rotor shaft also has two ends, wherein one end is coupled to the motor shaft and the other end is connected to the rotor. Often, the rotor shaft is comprised of graphite, the motor shaft is comprised of steel, and these two shafts are coupled by a coupling, which is usually comprised of steel. As the motor turns the drive shaft, the drive shaft turns the rotor and the rotor pushes molten metal out of the pump chamber, through the discharge, which may be an axial or tangential discharge, and into the molten metal bath. Most molten metal pumps are gravity fed, wherein gravity forces molten metal through the inlet and into the pump chamber as the rotor pushes molten metal out of the pump chamber. Molten metal pump casings and rotors usually employ a bearing system comprising ceramic rings wherein there are one or more rings on the rotor that align with rings in the pump chamber (such as rings at the inlet (which is usually the top of the pump chamber and bottom of the pump chamber) when the rotor is placed in the pump chamber. The purpose of the bearing system is to reduce damage to the soft, graphite components, particularly the rotor and pump chamber wall, during pump operation. A known bearing system is described in U.S. Pat. No. 5,203,681 to Cooper, the disclosure of which is incorporated herein by reference. As discussed in U.S. Pat. Nos. 5,591,243 and 6,093,000, each to Cooper, the disclosures of which are incorporated herein by reference, bearing rings can cause various operational and shipping problems and U.S. Pat. No. 6,093,000 discloses rigid coupling designs and a monolithic rotor to help alleviate this problem. Further, U.S. Pat. No. 2,948,524 to Sweeney et al., U.S. Pat. No. 4,169,584 to Mangalick, U.S. Pat. No. 5,203,681 to Cooper and U.S. Pat. No. 6,123,523 to Cooper (the disclosures of the afore-mentioned patents to Cooper, insofar as such disclosures are not inconsistent with the teachings of this application, are incorporated herein by reference) all disclose molten metal pumps. Furthermore, copending U.S. patent application Ser. No. ______ to Paul V. Cooper, filed on Feb. 4, 2004 and entitled “Pump With Rotating Inlet” discloses, among other things, a pump having an inlet and rotor structure (or other displacement structure) that rotate together as the pump operates in order to alleviate jamming. The disclosure of this copending application, insofar as such disclosures are not inconsistent with the teachings of this application, is incorporated herein by reference. The materials forming the components that contact the molten metal bath should remain relatively stable in the bath. Structural refractory materials, such as graphite or ceramics, that are resistant to disintegration by corrosive attack from the molten metal may be used. As used herein “ceramics” or “ceramic” refers to any oxidized metal (including silicon) or carbon-based material, excluding graphite, capable of being used in the environment of a molten metal bath. “Graphite” means any type of graphite, whether or not chemically treated. Graphite is particularly suitable for being formed into pump components because it is (a) soft and relatively easy to machine, (b) not as brittle as ceramics and less prone to breakage, and (c) less expensive than ceramics. Three basic types of pumps for pumping molten metal, such as molten aluminum, are utilized: circulation pumps, transfer pumps and gas-release pumps. Circulation pumps are used to circulate the molten metal within a bath, thereby generally equalizing the temperature of the molten metal. Most often, circulation pumps are used in a reverbatory furnace having an external well. The well is usually an extension of a charging well where scrap metal is charged (i.e., added). Transfer pumps are generally used to transfer molten metal from the external well of a reverbatory furnace to a different location such as a ladle or another furnace. Examples of transfer pumps are disclosed in U.S. Pat. No. 6,345,964 B1 to Cooper, the disclosure of which, insofar as such disclosures are not inconsistent with the teachings of this application, is incorporated herein by reference, and U.S. Pat. No. 5,203,68 1. Gas-release pumps, such as gas-injection pumps, circulate molten metal while releasing a gas into the molten metal. In the purification of molten metals, particularly aluminum, it is frequently desired to remove dissolved gases such as hydrogen, or dissolved metals, such as magnesium, from the molten metal. As is known by those skilled in the art, the removing of dissolved gas is known as “degassing” while the removal of magnesium is known as “demagging.” Gas-release pumps may be used for either of these purposes or for any other application for which it is desirable to introduce gas into molten metal. Gas-release pumps generally include a gas-transfer conduit having a first end that is connected to a gas source and a second submerged in the molten metal bath. Gas is introduced into the first end and is released from the second end into the molten metal. The gas may be released downstream of the pump chamber into either the pump discharge or a metal-transfer conduit extending from the discharge, or into a stream of molten metal exiting either the discharge or the metal-transfer conduit. Alternatively, gas may be released into the pump chamber or upstream of the pump chamber at a position where it enters the pump chamber. A system for releasing gas into a pump chamber is disclosed in U.S. Pat. No. 6,123,523 to Cooper. Another gas-release pump is disclosed in a co-pending U.S. Patent application filed on Feb. 4, 2004 and entitled “System for Releasing Gas Into Molten Metal” to Paul V. Cooper, the disclosure of which that is not inconsistent with the teachings of this application is incorporated herein by reference. A problem with known molten metal pumps is that machining the graphite components, such as the rotor and rotor shaft, can create weak points that may break during operation. For example, it is known to machine threads into an end of a rotor shaft in order for the end to be received in the threaded bore of a coupling so that the coupling (connected to a motor shaft at the end opposite the rotor shaft) can drive the rotor shaft. The threads formed in the end of the rotor shaft are typically pointed and create weak areas that can cause the rotor shaft to break during operation. A similar type of threaded connection is often used to connect the rotor shaft to the rotor. Further, it is known to machine an end of the rotor shaft to create opposing flat surfaces that are received in the coupling. Removing this material from the end of the rotor shaft also weakens the shaft and can cause breakage. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention includes improved rotor shafts, and a coupling and rotor that can be used with one or more of the improved rotor shafts. One rotor shaft according to the invention has a first end for connecting to a coupling and a second end for connecting to a rotor. The first end has an outer surface, preferably having a generally annular outer wall, and a vertical keyway formed in the outer surface. The first end is received in a cavity of a coupling wherein the cavity includes a projection that is received at least partially in the keyway and the projection applies driving force to the rotor shaft as the coupling turns. Another rotor shaft according to the invention has a second end including flat, shallow threads, rather than threads that end in a point (also referred to herein as “pointed threads”). This shaft is used with a rotor having a connective portion, wherein the connective portion is a bore that also includes flat, shallow threads and the second end of the rotor shaft is received in the connective portion. A rotor shaft according to the invention may also have both a first end and a second end as described above. Further, a rotor shaft according to the invention may have a first end with shallow, flat threads that is used with a coupling having shallow, flat threads to receive the first end. Also disclosed herein are a coupling and rotor that may be used with one or more rotor shafts according to the invention and pumps including one or more of the improved components. | 20040204 | 20081230 | 20050120 | 65269.0 | 0 | KASTLER, SCOTT R | MOLTEN METAL PUMP COMPONENTS | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,773,321 | ACCEPTED | Suspension for bicycle seat and handlebar support | A suspension device for disposition between a support post of a bicycle and a suspended member, such as a bicycle seat and bicycle handlebars, having an invertible connector body with a support post mounting, a horizontal median and two shoulder surfaces disposed above the median or below the median. The connector body has at least two sleeves with two slide pins slidably mounted in and passing through the two sleeves, and a top bracket and a bottom bracket fixed to top and bottom ends of said slide pins, with two springs disposed between the shoulder surfaces and the brackets and a seat or handlebar mounting connected to the top bracket. | 1. A suspension device for disposition between a support post of a bicycle and a suspended member, including a bicycle seat and bicycle handlebars, the device comprising: an invertible connector body having a support post mounting, a horizontal median and two shoulder surfaces disposed in a position selected from the group consisting of: above the median; and below the median, the connector body having two sleeves; two slide pins slidably mounted in and passing through said two sleeves; a top bracket and a bottom bracket fixed to top and bottom ends of said slide pins; two springs disposed between said shoulder surfaces and one of said brackets; and a suspended member mounting connected to the top bracket. 2. A suspension device according to claim 1 wherein the invertible connector body has two laterally extending tabs within which the sleeves extend and each tab having top and bottom shoulder surfaces. 3. A suspension device according to claim 1 wherein the invertible connector body includes a third sleeve housing a third slide pin with top and bottom ends fixed to the top and bottom brackets. 4. A suspension device according to claim 3 including a third spring disposed between the connector body and one of the top and bottom brackets. 5. A suspension device according to claim 3 wherein the third slide pin has the suspended member mounting connected to a top end thereof. 6. A suspension device according to claim 1 wherein the springs are disposed about the slide pins. 7. A suspension device according to claim 1 wherein at least one slide pin includes a resilient ring disposed between one end and one said bracket. 8. A suspension device according to claim 7 wherein the resilient ring comprises a neoprene elastomer. 9. A suspension device according to claim 1 wherein the sleeves include sleeve bearings. 10. A suspension device according to claim 9 wherein the sleeve bearings are polymer bearings. 11. A suspension device according to claim 1 wherein the top and bottom bracket comprise a split housing with a clamping screw. 12. A suspension device according to claim 1 wherein the support post mounting of the connector body comprises a split through bore with at least one clamping screw. 13. A suspension device according to claim 1 wherein the suspended member mounting comprises a horizontal bore. 14. A suspension device according to claim 13 wherein the horizontal bore is split and the suspended member mounting includes a cam locking clamp. 15. A suspension device according to claim 13 including a split seat rail clamp adapted for mounting within the horizontal bore and having two ends with seat rail engaging surfaces. 16. A suspension device according to claim 15 wherein the split seat rail clamp has slots engaging a resilient elastomer material. | TECHNICAL FIELD The invention relates to a shock terminator suspension for a bicycle seat and for a bicycle handlebar. BACKGROUND OF THE ART The design of conventional bicycles includes various means to reduce the shock and impact imposed on by the rider and bicycle. For example, pneumatic tires and spring loaded seats are a minimum provision whereas modern mountain bikes include spring loaded shock absorbers on front forks as well as rear shock absorbers between a hinged rear wheel mounting and the bicycle frame. A significant disadvantage of conventional shock absorbers is cost and weight. Specially designed front forks can be retrofit to an existing bicycle frame fairly easily but must be purchased and installed. For rear shocks, the entire bicycle frame must be specially adapted since the rear wheel suspension is hinged to the frame and the seat is usually supported on a cantilevered post. Retrofitting rear wheel shocks is impractical and a specially adapted frame is required. It is an object of the present invention to provide a simple inexpensive suspension device for both the bicycle handlebars and the seat which can be retrofit to any bicycle frame, is easily adjustable and configured. Further objects of the invention will be apparent from review of the disclosure, drawings and description of the invention below. DISCLOSURE OF THE INVENTION The invention provides a suspension device for disposition between a support post of a bicycle and a suspended member, such as a bicycle seat and bicycle handlebars, having an invertible connector body with a support post mounting, a horizontal median and two shoulder surfaces disposed above the median or below the median. The connector body has at least two sleeves with two slide pins slidably mounted in and passing through the two sleeves, and a top bracket and a bottom bracket fixed to top and bottom ends of said slide pins, with two springs disposed between the shoulder surfaces and the brackets and a seat or handlebar mounting connected to the top bracket. DESCRIPTION OF THE DRAWINGS In order that the invention may be readily understood, one embodiment of the invention is illustrated by way of example in the accompanying drawings. FIG. 1 is a side elevation view of a conventional bicycle, having no front or rear shock absorbers, with the suspension device according to the invention disposed between the seat support post and the seat, and between the front handlebars and the handlebar support stem. FIG. 2 is side view of the suspension device in one configuration. FIG. 3 is front view of the suspension device. FIG. 4 is a sectional view through the connector body along line 4-4 of FIG. 3. FIG. 5 is an exploded view of a second embodiment of the suspension device with similar lower members (except that the connector body is inverted as in FIG. 7) and having a top suspended member mount that varies from that shown in FIG. 2 in that it includes a quick release cam locking clamp. FIG. 6 is a front perspective view of the configuration shown in FIG. 2 with two relatively short springs. FIG. 7 shows a different configuration with the connector body inverted and with three springs, two of which are relatively longer. FIGS. 8-9 are side views similar to FIG. 2 showing some of the various configurations possible. Further details of the invention and its advantages will be apparent from the detailed description included below. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 shows a conventional bicycle frame 1 with no shock absorbing front shocks or rear wheel suspension system. Two suspension devices 2 according to the invention are installed, namely: between the seat post 3 and the seat 4; and between the handlebar stem 5 and the handlebars 6. FIGS. 2-5 show the details of a preferred embodiment of the suspension device in one configuration. Other possible configurations are suggested by FIGS. 8-9, and others are of course possible when the invertible connector body 7 is inverted and different numbers and lengths of springs 8 are used, as in FIG. 7. The invertible connector body 7 can be mounted to the seat post 3 or handlebar stem 5 equally. The connector body 7 can include a mounting which as best seen in FIG. 4 comprises a split bore 9 which clamps the supporting post 3, 5 with two clamping screws 10. The invertible connector body 7 can have a horizontal median 11 and two laterally extending tabs 12 with sleeves 13 extending through. The top and bottom shoulder surfaces 14, 15 of the tabs 12 in the embodiment shown engage the springs 8 which may be disposed about the two slide pins 16. The slide pins 16 are slidably mounted in and pass through the sleeves 13. Top bracket 17 and bottom bracket 18 may be fixed by various means or preferably clamped in a removable manner to the top and bottom ends of the slide pins 16. As best seen in FIG. 5 the top and bottom brackets 17, 18 may be split housings removably clamped to the slide pins with clamping screws 19. The springs 8 can be pre-loaded or pre-compressed to a selected degree by loosening the clamping screws 19, sliding the top bracket 17 downward and then re-tightening the clamping screws 19. As a result, the resilience of the compression springs 8 may be modified through pre-compression to result in a tighter or looser suspension in a very simple manner. The springs 8 in the embodiments shown are compression springs compressed under load between the top bracket 17 and the top shoulder surface 14 of the tabs 12. However it will be equally apparent that tension springs may be disposed between the bottom bracket 18 and the bottom shoulder surface 15 of the tabs 12 in addition to or in replacement of the compression springs 8 shown. Further the embodiments shown all include a third slide pin 20 with top and bottom ends clamped into the top and bottom brackets 17, 18 to slide vertically with the two lateral slide pins 16. The third slide pin 20 is shown with a relatively larger diameter than the lateral pins 16 but this is not essential and any relative size may be selected. The third slide pin 20 is also slidably mounted to the invertible connector body 7 in a third sleeve 21. the embodiment shown in FIG. 7 shows the third slide pin 21 fitted with a third spring 22 between the top bracket 17 and the invertible connector body 7 for added resilience in combination with lateral springs 8 of extended length. The third spring 22 could also be located between the bottom bracket 18 and the connector body 7 either in tension or possibly in compression for damping the upstroke. As shown in FIG. 4, the sleeves 13, 21 may be arranged in a triangular pattern to reduce torque on the sliding assembly and reduce bending moment of the assembly in use. Sleeve bearings 25 of polymer may be installed between the slide pins 16, 20 and their respective sleeves 13, 21 in the invertible connector body 7 to provide wear resistance, and ease of sliding operation. Resilient neoprene elastomer rings 26 between the slide pins 16, 20 and the top and bottom brackets 17, 18 optionally provide further damping capacity. In the embodiments illustrated the handlebar 6 or seat 4 suspended member mounting head 23 is connected to the top end of the third slide pin 20 with a spring tension pin 24. The mounting head has a horizontal bore 27 that can accommodate handlebars 6 passed through, or can hold the split seat rail clamp 28 that has two extending ends with seat rail engaging surfaces 29 to clamp and secure the longitudinal rails (not shown) of the seat 4. The horizontal bore 27 is split and clamps the handlebars 6 or rail clamp 28 when closed with a simple bolt or in the second embodiment shown in FIG. 5, with a cam locking clamp 30. The split rail seat clamp 28 has slots 31 for engaging a resilient elastomer material to resist seat rotation when clamped in the horizontal bore. The invention provides a suspension device that can be retrofitted to both the seat post 3 and the handlebar stem 5 easily and without modifying the bicycle frame 1. The design is robust and very simple to adjust, repair and reconfigure as suggested by comparison between FIGS. 6 and 7 as well as FIGS. 8-9. The connector body can be inverted or rotated, the mounting head 23 can be rotated, two or three springs 8, 22 may be installed, different strengths or lengths of springs 8, 22 can be easily accommodated and the brackets 17, 18 can be used to pre-compress the springs 8, 22 if desired. In the embodiment shown, all adjustments and repairs can be undertaken with simple tools like an Allen key only. Although the above description relates to a specific preferred embodiment as presently contemplated by the inventor, it will be understood that the invention in its broad aspect includes mechanical and functional equivalents of the elements described herein. | <SOH> BACKGROUND OF THE ART <EOH>The design of conventional bicycles includes various means to reduce the shock and impact imposed on by the rider and bicycle. For example, pneumatic tires and spring loaded seats are a minimum provision whereas modern mountain bikes include spring loaded shock absorbers on front forks as well as rear shock absorbers between a hinged rear wheel mounting and the bicycle frame. A significant disadvantage of conventional shock absorbers is cost and weight. Specially designed front forks can be retrofit to an existing bicycle frame fairly easily but must be purchased and installed. For rear shocks, the entire bicycle frame must be specially adapted since the rear wheel suspension is hinged to the frame and the seat is usually supported on a cantilevered post. Retrofitting rear wheel shocks is impractical and a specially adapted frame is required. It is an object of the present invention to provide a simple inexpensive suspension device for both the bicycle handlebars and the seat which can be retrofit to any bicycle frame, is easily adjustable and configured. Further objects of the invention will be apparent from review of the disclosure, drawings and description of the invention below. | 20040209 | 20060124 | 20051027 | 67930.0 | 0 | LUM VANNUCCI, LEE SIN YEE | SUSPENSION FOR BICYCLE SEAT AND HANDLEBAR SUPPORT | SMALL | 0 | ACCEPTED | 2,004 |
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10,773,332 | ACCEPTED | Aryl phenylheterocyclyl sulfide derivatives and their use as cell adhesion-inhibiting anti-inflammatory and immune-supressive agents | The present invention relates to novel heterocyclyl-containing diaryl sulfide compounds that are useful for treating inflammatory and immune diseases, to pharmaceutical compositions comprising these compounds, and to methods of inhibiting inflammation or suppressing immune response in a mammal. | 1. A compound of formula I or a pharmaceutically acceptable salt or prodrug thereof, wherein R1, R2, R3, R4 and R5 are each independently selected from hydrogen, halogen, alkyl, haloalkyl, alkoxy, cyano, nitro, cycloalkyl, carboxaldehyde, and a group of formula II defined as and wherein at least one of R1 or R3 is a pyridine: D, B, Y and Z are each independently selected from —CR6═, —CR7R8—, —C(O)—, —O—, —SO2—, —S—, —N═, and —NR9—; n is an integer of zero to three; R6, R7, R8 and R9, are each independently selected from hydrogen, alkyl, carboxy, hydroxyalkyl, alkylaminocarbonyl alkyl, dialkylaminocarbonylalkyl and carboxyalkyl; and R10 and R11 are each independently selected from hydrogen, alkyl, cycloalkyl, alkoxyalkyl, alkoxycarbonylalkyl, carboxyalkyl, hydroxyalkyl, heterocyclyl, heterocyclylalkyl and heterocyclylamino; or R10 and R11 are taken together with N to form a three to seven membered unsubstituted heterocyclyl or a three to seven membered substituted heterocyclyl ring, substituted with at least one substituent R13, wherein R13 is independently selected from alkyl, alkylene, alkoxy, alkoxyalkyl, cycloalkyl, aryl, heterocyclyl, heterocyclylalkyl, heterocyclylcarbonyl, heterocyclylalkylaminocarbonyl, hydroxy, hydroxyalkyl, hydroxyalkoxyalkyl, carboxy, carboxyalkyl, carboxycarbonyl, carboxaldehyde, alkoxycarbonyl, arylalkoxycarbonyl, aminoalkyl, aminoalkanoyl, aminocarbonyl, carboxamido, alkoxycarbonylalkyl, carboxamidoalkyl, cyano, tetrazolyl, alkanoyl, hydroxyalkanoyl, alkanoyloxy, alkanoylamino, alkanoyloxyalkyl, alkanoylaminoalkyl, sulfonate, alkylsulfonyl, alkylsulfonylaminocarbonyl, arylsulfonylaminocarbonyl and heterocyclylsulfonylaminocarbonyl; A is an unsubstituted aryl group, an unsubstituted heterocyclyl group, a substituted aryl, or a heterocycyl group substituted with at least one substituent R12, wherein R12 is independently selected from halogen, alkyl, aryl, haloalkyl, hydroxy, alkoxy, alkoxyalkyl, alkoxycarbonyl, alkoxyalkoxy, hydroxyalkyl, aminoalkyl, aminocarbonyl, alkyl(alkoxycarbonylalkyl) aminoalkyl, heterocyclyl, heterocyclylalkyl, carboxaldehyde, carboxaldehyde hydrazone, carboxamido, alkoxycarbonylalkyl, carboxy, carboxyalkyl, carboxyalkoxy, hydroxyalkylaminocarbonyl, cyano, amino, heterocyclylalkylamino, carboxythioalkoxy, carboxycycloalkoxy, thioalkoxy, carboxyalkylamino, trans-cinnamyl and heterocyclylalkylaminocarbonyl; and wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12 and R13 are unsubstituted or substituted with at least one electron donating or electron withdrawing group; wherein the heterocyclyl is selected from 3-, 4-, 5-, 6- and 7-membered rings containing 1-3 heteroatoms independently selected from nitrogen, oxygen and sulfur; the 4- and 5-membered rings have zero to two double bonds and the 6- and 7-membered rings have zero to three double bonds, the heterocycyl being optionally substituted with alkyl, halogen, hydroxy or alkyl substituents, further wherein the heterocycyl optionally comprises a group chosen from: (i) bicyclic, tricyclic, and tetracyclic groups in which any of the above heterocyclic rings is fused to one or two rings independently selected from an aryl ring, a cyclohexane ring, a cyclohexane ring, a cyclopentane ring, a cyclopentene ring, and another monocyclic heterocyclic ring; (ii) bridged bicyclic groups where a monocyclic heterocyclic group is bridged by alkylene group optionally selected from and (iii) compounds of the formula where X* and Z* are each independently selected from —CH2—, —CH2NH—, —CH2O—, —NH— and —O—, with the proviso that at least one of X* and Z* is not —CH2—, and Y* is selected from —C(O)— and —(C(R″)2)v—, where R″ is hydrogen or alkyl of one to four carbons, and v is 1-3. 2. A compound according to claim 1 wherein R3 is the group of formula II wherein R10, R11, D, B, Y, Z, and n are defined as in claim 1; and R1 is defined as in claim 1 with the proviso that if R3 does not define a pyridine, then R1 is a pyridine. 3. A compound according to claim 1 of formula III wherein p is an integer of one to five. 4. A compound according to claim 3 wherein p is one; R4 and R5 are hydrogen; R12 is selected from halogen, alkyl, alkoxy, carboxyalkoxy, carboxyalkyl and heterocyclyl; R10 and R11 are taken together with N to form a three to seven membered unsubstituted heterocyclyl ring, or a three to seven membered substituted heterocycyl ring, substituted with at least one substituent R13 and wherein said substituted heterocyclyl, or unsubstituted heterocyclyl ring is selected from piperidine, piperazine, morpholine, pyrrolidine, and azetidine. 5. A compound according to claim 1 of formula IV wherein D and B are each independently selected from —N═ and —CR6═; R1 is selected from hydrogen, halogen and haloalkyl, with the proviso that if R3 does not define a pyridine, then R1 is a pyridine; R2 is selected from hydrogen, halogen and haloalkyl; and p is an integer of one to five. 6. A compound according to claim 5 wherein p is one; and R10 and R11 are taken together with N to form a three to seven membered substituted heterocyclyl ring, or a three to seven membered unsubstituted heterocycyl ring, substituted with at least one substituent R13, wherein R13 is defined as in claim 1, and wherein said substituted heterocycyl ring, or unsubstituted heterocyclyl ring is selected from piperidine, piperazine, morpholine, pyrrolidine, and azetidine. 7. A compound according to claim 1, selected from N-(1-(4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-yl)-acetamide, 1-(4-(4-(2-methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-ol, N-1-(4-(4-(2-methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-yl)-acetamide, N-(1-(4-(4-(2,3-dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl) pyridin-2-yl)-pyrrolidin-3-yl)-acetamide, 4′-(4-(2,3-dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-carboxylic acid, and 4′-(4-(2,3-dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-3-carboxylic acid. 8. A composition comprising: a compound according to claim 1 and a pharmaceutically acceptable carrier. 9. A method of inhibiting inflammation or suppressing immune response in a mammal comprising administering to said mammal a therapeutic amount of a compound according to claim 1. 10. A compound according to claim 1 wherein A is (i) an unsubstituted or substituted aryl group, substituted by at least one substituent R12, wherein R12 is defined as in claim 1, or (ii) an unsubstituted or substituted heterocyclyl group of the formula wherein R12 is defined as in claim 1; p is an integer of one to three; X* and Z* are each independently selected from —CH2—, —CH2NH—, —CH2O—, —NH—, and —O—, with the proviso that at least one of X* and Z* is not —CH2—; and Y* is —(C(R″)2)v—, wherein R″ is hydrogen or alkyl; and v is 1, 2, or 3. 11. A compound according to claim 1 or 10 wherein A is an unsubstituted or substituted aryl group, wherein the aryl group is (I) a mono- or a bicyclic carbocyclic ring system having one or two aromatic rings, or (ii) a mono- or a bicyclic carbocyclic ring system having one or two aromatic rings, wherein one or more than one of the aromatic rings is fused to a ring selected from cyclohexane, cyclohexene, cyclopentane, and cyclopentene. 12. A compound according to claim 1 wherein A is an unsubstituted or substituted aryl group of the formula wherein R12 is defined as in claim 1; and p is an integer of one to five. 13. A compound according to claim 1 wherein D is CR6═ or —N═, B is —S—, —O—, —CR6═ or —N═, Y is —CR6═ or —N═, Z is —CR6═ or —N═; and n is zero or one. 14. A compound according to claim 1 wherein R3 is selected from 15. A compound according to claim 1 wherein R1 or R3 is a group of formula II wherein D is —CR6═; B is —O— or —S—; Y is —N═; and n is zero. 16. A compound according to claim 1 wherein D is —CR6═ or —N═; B is —N═; Y is CR6═; and n is one. 17. A compound according to claim 1 wherein R1 is selected from hydrogen, halogen, alkyl, nitro, and R2 is selected from hydrogen, halogen, alkyl, and nitro; R4 and R5 are each independently selected from hydrogen and alkyl; and R3 is wherein D is —CR6═ or —N═, B is —S—, —O—, —CR6═ or —N═, Y is —CR6═ or —N═, Z is —CR6═ or —N═; and n is zero or one. 18. A compound according to claim 1 wherein R1 and R2 are each independently selected from hydrogen, halogen, and haloalkyl; R3 is a pyridine; and R4 and R5 are each hydrogen. 19. A compound according to claim 1 wherein R1 is selected from hydrogen, halogen, haloalkyl, and R2 is selected from hydrogen, halogen, and haloalkyl; R4 and R5 are each hydrogen; and R3 is wherein D is —CR6═ or —N═, B is —S—, —O—, —CR6═ or —N═, Y is —CR6═ or —N═, Z is —CR6═ or —N═; and n is zero or one. 20. A compound according to claim 1 wherein R1 is selected from hydrogen, halogen, haloalkyl, and R2 is selected from hydrogen, chloro, and trifluoromethyl; R4 and R5 are each hydrogen; and R3 is selected from 21. A compound according to claim 1 wherein R6 is hydrogen. 22. A compound according to claim 1 wherein R1 is selected from hydrogen, halogen, and haloalkyl, R2 is selected from hydrogen and halogen, R3 is a pyridine, and R4 and R5 are each hydrogen. 23. A compound according to claim 22 wherein R1 is trifluoromethyl, R2 is hydrogen, and R3 is a pyridine. 24. A compound according to claim 22 wherein R1 and R2 are each chloro, and R3 is a pyridine. 25. A compound according to claim 1 which has an IC50 of less than 20 μM when tested in one or both of (i) an ICAM-1/LFA-1 Biochemical Interaction Assay, or (ii) an ICAM-1/JY-8 Cell Adhesion Assay 26. A method for ameliorating a pathology in a mammal arising from the interaction of LFA-1 with ICAM-1 or ICAM-3 comprising administering to said mammal a therapeutic amount of a compound according to claim 1. 27. A method according to claim 26 wherein the pathology is selected from an inflammatory disease, an autoimmune disease, tumor metastasis, allograft rejection and reperfusion injury. | This application is a Divisional Application of pending prior application Ser. No. 09/888,840, filed Jun. 25, 2001, which claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 60/214,983, filed Jun. 29, 2000, the disclosures of which are incorporated herein by reference. TECHNICAL FIELD The present invention relates to compounds that are useful for treating inflammatory and immune diseases, to pharmaceutical compositions comprising these compounds, and to methods of inhibiting inflammation or suppressing immune response in a mammal. BACKGROUND OF THE INVENTION Inflammation results from a cascade of events that includes vasodilation accompanied by increased vascular permeability and exudation of fluid and plasma proteins. This disruption of vascular integrity precedes or coincides with an infiltration of inflammatory cells. Inflammatory mediators generated at the site of the initial lesion serve to recruit inflammatory cells to the site of the injury. These mediators (chemokines such as IL-8, MCP-1, MIP-1, and RANTES, complement fragments and lipid mediators) have chemotactic activity for leukocytes and attract the inflammatory cells to the inflamed lesion. These chemotactic mediators which cause circulating leukocytes to localize at the site of inflammation require the cells to cross the vascular endothelium at a precise location. This leukocyte recruitment is accomplished by a process called cell adhesion. Cell adhesion occurs through a coordinately regulated series of steps that allow the leukocytes to first adhere to a specific region of the vascular endothelium and then cross the endothelial barrier to migrate to the inflamed tissue (Springer, T. A., 1994, “Traffic Signals for Lymphocyte Recirculation and Leukocyte Emigration: The Multistep Paradigm”, Cell, 76: 301-314; Lawrence, M. B., and Springer, T. A., 1991, “Leukocytes' Roll on a Selectin at Physiologic Flow Rates: Distinction from and Prerequisite for Adhesion Through Integrins”, Cell 65: 859-873; von Adrian, U., Chambers, J. D., McEnvoy, L. M., Bargatze, R. F., Arfos, K. E, and Butcher, E. C., 1991, “Two-Step Model of Leukocyte-Endothelial Cell Interactions in Inflammation”, Proc. Nat'l. Acad. Sci. USA, 88: 7538-7542; and Ley, K., Gaehtgens, P., Fennie, C., Singer, M. S., Lasky, L. H. and Rosen, S. D.,1991, “Lectin-Like Cell Adhesion Molecule 1 Mediates Rolling in Mesenteric Venules in vivo”, Blood, 77: 2553-2555). These steps are mediated by families of adhesion molecules such as integrins, Ig supergene family members, and selectins which are expressed on the surface of the circulating leukocytes and on the vascular endothelial cells. The first step consists of leukocytes rolling along the vascular endothelial cell lining in the region of inflammation. The rolling step is mediated by an interaction between a leukocyte surface oligosaccharide, such as Sialylated Lewis-X antigen (SLex), and a selectin molecule expressed on the surface of the endothelial cell in the region of inflammation. The selectin molecule is not normally expressed on the surface of endothelial cells but rather is induced by the action of inflammatory mediators such as TNF-α and interleukin-1. Rolling decreases the velocity of the circulating leukocyte in the region of inflammation and allows the cells to more firmly adhere to the endothelial cell. The firm adhesion is accomplished by the interaction of integrin molecules that are present on the surface of the rolling leukocytes and their counter-receptors (the Ig superfamily molecules) on the surface of the endothelial cell. The Ig superfamily molecules or CAMs (Cell Adhesion Molecules) are either not expressed or are expressed at low levels on normal vascular endothelial cells. The CAM's, like the selecting, are induced by the action of inflammatory mediators like TNF-alpha and IL-1. The final event in the adhesion process is the extravasation of leukocytes through the endothelial cell barrier and their migration along a chemotactic gradient to the site of inflammation. This transmigration is mediated by the conversion of the leukocyte integrin from a low avidity state to a high avidity state. The adhesion process relies on the induced expression of selectins and CAM's on the surface of vascular endothelial cells to mediate the rolling and firm adhesion of leukocytes to the vascular endothelium. The interaction of the intercellular adhesion molecule ICAM-1 (cd54) on endothelial cells with the integrin LFA-1 on leukocytes plays an important role in endothelial-leukocyte contact. Leukocytes bearing high-affinity LFA-1 adhere to endothelial cells through interaction with ICAM-1, initiating the process of extravasation from the vasculature into the surrounding tissues. Thus, an agent which blocks the ICAM-1/LFA-1 interaction suppresses these early steps in the inflammatory response. Consistent with this background, ICAM-1 knockout mice have numerous abnormalities in their inflammatory responses. The present invention discloses compounds which bind to the interaction-domain (1-domain) of LFA-1, thus interrupting endothelial cell-leukocyte adhesion by blocking the interaction of LFA-1 with ICAM-1, ICAM-3, and other adhesion molecules. These compounds are useful for the treatment or prophylaxis of diseases in which leukocyte trafficking plays a role, notably acute and chronic inflammatory diseases, autoimmune diseases, tumor metastasis, allograft rejection, and reperfusion injury. SUMMARY OF THE INVENTION The present invention is directed to compounds of the structure wherein R1, R2, R3, R4 and R5 are each independently selected from the group consisting of hydrogen, halogen, alkyl, haloalkyl, alkoxy, cyano, nitro, cycloalkyl and carboxaldehyde; with the proviso that at least one of R1 or R3 is wherein D, B, Y and Z at each occurrence are independently selected from the group consisting of —CR6═, —CR7R8—, —C(O)—, —O—, —SO2—, —S—, —N═, and —NR9—; n is an integer of zero to three; R6, R7, R8 and R9, at each occurrence, are each independently selected from the group consisting of hydrogen, alkyl, carboxy, hydroxyalkyl, alkylaminocarbonyl alkyl, dialkylaminocarbonylalkyl and carboxyalkyl; and R10 and R11 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, alkoxyalkyl, alkoxycarbonylalkyl, carboxyalkyl, hydroxyalkyl, heterocyclyl, heterocyclylalkyl and heterocyclylamino; wherein R10 and R11 may be joined to form a three to seven membered heterocyclyl ring, said ring being optionally substituted with one or more substituents R13, wherein R13, at each occurrence is independently selected from the group consisting of alkyl, alkylene, alkoxy, alkoxyalkyl, cycloalkyl, aryl, heterocyclyl, heterocyclylalkyl, heterocyclylcarbonyl, heterocyclylalkylaminocarbonyl, hydroxy, hydroxyalkyl, hydroxyalkoxyalkyl, carboxy, carboxyalkyl, carboxycarbonyl, carboxaldehyde, alkoxycarbonyl, arylalkoxycarbonyl, aminoalkyl, aminoalkanoyl, aminocarbonyl, carboxamido, alkoxycarbonylalkyl, carboxamidoalkyl, cyano, tetrazolyl, alkanoyl, hydroxyalkanoyl, alkanoyloxy, alkanoylamino, alkanoyloxyalkyl, alkanoylaminoalkyl, sulfonate, alkylsulfonyl, alkylsulfonylaminocarbonyl, arylsulfonylaminocarbonyl and heterocyclylsulfonylaminocarbonyl; wherein A is an aryl or heterocyclyl group, said aryl or heterocyclyl group having at least one substituent R12, wherein R12 is selected from the group consisting of hydrogen, halogen, alkyl, aryl, haloalkyl, hydroxy, alkoxy, alkoxyalkyl, alkoxycarbonyl, alkoxyalkoxy, hydroxyalkyl, aminoalkyl, aminocarbonyl, alkyl(alkoxycarbonylalkyl) aminoalkyl, heterocyclyl, heterocyclylalkyl, carboxaldehyde, carboxaldehyde hydrazone, carboxamide, alkoxycarbonylalkyl, carboxy, carboxyalkyl, carboxyalkyl, carboxyalkoxy, carboxythioalkoxy, carboxycycloalkoxy, thioalkoxy, carboxyalkylamino, trans-cinnamyl, hydroxyalkylaminocarbonyl, cyano, amino, heterocyclylalkylamino, and heterocyclylalkylaminocarbonyl; and wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11 and R12 are unsubstituted or substituted with at least one electron donating or electron withdrawing group; or a pharmaceutically-acceptable salt, optical isomer or prodrug thereof. Presently preferred compounds of Formula I have R3 as Formula II (shown above), with substituents defined as above, R1 and R2 each independently as hydrogen, halogen, haloalkyl or nitro; and R4 and R5 each independently as hydrogen or alkyl. The present invention is also directed to compounds of the structure wherein R1, R2, R4 and R5 are each independently selected from the group consisting of hydrogen, halogen, alkyl, haloalkyl, alkoxy, cyano, nitro, cycloalkyl and carboxaldehyde; D, B, Y and Z are as defined above; R12, at each occurrence, is independently selected from the group consisting of hydrogen, halogen, alkyl, haloalkyl, alkoxy, carboxyalkoxy, carboxyalkyl and heterocyclyl; and, p is an integer of zero to five; wherein R1, R2, R4, R5, R10, R11 and R12 are unsubstituted or substituted with at least one electron donating group or electron withdrawing group. Presently most preferred compounds of Formula III have p as one; R4 and R5 as hydrogen; R12 as halogen, alkyl, alkoxy, carboxyalkoxy, carboxyalkyl or heterocyclyl; and R10 and R11 joined to form a three to seven membered heterocyclyl ring; said ring being piperidine, piperazine, morpholine, pyrrolidine or azetidine. Presently most preferred compounds are of the structure wherein D and B are each independently selected from the group consisting of —N═ and —CR6═; R1 and R2 are each independently selected from the group consisting of hydrogen, halogen and haloalkyl; R10 and R11 are as defined above for Formula I; R12, at each occurrence, is independently selected from the group consisting of hydrogen, halogen, alkyl, haloalkyl, alkoxy, carboxyalkoxy, carboxyalkyl and heterocyclyl; and, p is an integer of zero to five; wherein R1, R2, R10, R11 and R12 are unsubstituted or substituted with at least one electron donating group or electron withdrawing group. For presently most preferred compounds of Formula IV, p may be one; R12 may be halogen, alkyl, alkoxy, carboxyalkoxy, carboxyalkyl or heterocyclyl; and R10 and R11 may be joined to form a three to seven membered heterocyclyl ring; said ring being piperidine, piperazine, morpholine, pyrrolidine or azetidine. The compounds represented by structural Formula I, above, may be prepared by synthetic processes or by metabolic processes. Processes for the preparation of the compounds of the present invention by metabolic processes include those occurring in the human or animal body (in vivo) or by processes occurring in vitro. The present invention is also directed to a method of treatment or prophylaxis in which the inhibition of inflammation or suppression of immune response is desired, comprising administering an effective amount of a compound having Formula I. In yet another embodiment of the invention are disclosed pharmaceutical compositions containing compounds of Formula I. DETAILED DESCRIPTION OF THE INVENTION Definition of Terms The term “alkanoyl” as used herein refers to an alkyl group attached to the parent molecular group through a carbonyl group. The term “alkanoylamino” as used herein refers to an alkanoyl group attached to the parent molecular group though an amino group. The term “alkanoylaminoalkyl” as used herein refers to an alkanoylamino group attached to the parent molecular group through an alkyl group. The term “alkanoyloxy” as used herein refers to an alkanoyl group attached to the parent molecular group through an oxygen radical. The term “alkanoyloxyalkyl” as used herein refers to an alkanoyloxy group attached to the parent molecular group through an alkyl group. The term “alkoxy” as used herein refers to an alkyl group attached to the parent molecular group through an oxygen atom. The term “alkoxyalkoxy” as used herein refers to an alkoxy group attached to the parent molecular group through an alkoxy group. The term “alkoxyalkyl” as used herein refers to an alkoxy group attached to the parent molecular group through an alkyl group. The term “alkoxycarbonyl” as used herein refers to an alkoxy group attached to the parent molecular group through a carbonyl group. The term “alkoxycarbonylalkyl” as used herein refers to an alkoxycarbonyl group attached to the parent molecular group through an alkyl group. The term “alkyl” as used herein refers to a saturated straight or branched chain group of 1-10 carbon atoms derived from an alkane by the removal of one hydrogen atom. The term “alkyl(alkoxycarbonylalkyl)amino” as used herein refers to an amino group substituted with one alkyl group and one alkoxycarbonylalkyl group. The term “alkyl(alkoxycarbonylalkyl)aminoalkyl” as used herein refers to an alkyl(alkoxycarbonylalkyl)amino group attached to the parent molecular group through an alkyl group. The term “alkylene” as used herein refers to a divalent group of 1-10 carbon atoms derived from a straight ox branched chain alkane by the removal of two hydrogen atoms. The term “alkylsulfonyl” as used herein refers to an alkyl radical attached to the parent molecular group through an —SO2— group. The term “alkylsulfonylaminocarbonyl” as used herein refers to an alkylsulfonyl group attached to the parent molecular group through an aminocarbonyl group. The term “amino” as used herein refers to a radical of the form —NRaRb, or to a radical of the form —NRa—, where Ra and Rb are independently selected from hydrogen, alkyl or cycloalkyl. The term “aminoalkanoyl” as used herein refers to an amino group attached to the parent molecular group through an alkanoyl group. The term “aminoalkyl” as used herein refers to an amino group attached to the parent molecular group through an alkyl group. The term “aminocarbonyl” as used herein refers to an amino group attached to the parent molecular group through a carbonyl group. The term “aryl” as used herein refers to a mono- or bicyclic carbocyclic ring system having one or two aromatic rings. The aryl group can also be fused to a cyclohexane, cyclohexene, cyclopentane or cyclopentene ring. The aryl groups of this invention can be optionally substituted with alkyl, halogen, hydroxy, or alkoxy substituents. The term “arylalkoxy” as used herein refers to an aryl group attached to the parent molecular group through an alkoxy group. The term “arylalkoxycarbonyl” as used herein refers to an arylalkoxy group attached to the parent molecular group through a carbonyl group. The term “arylsulfonyl” as used herein refers to an aryl radical attached to the parent molecular group through an —SO2— group. The term “arylsulfonylaminocarbonyl” as used herein refers to an arylsulfonyl group attached to the parent molecular group through an aminocarbonyl group. The term “carboxaldehyde” as used herein refers to the radical —CHO. The term “carboxaldehyde hydrazone” as used herein refers to the radical —CH═N—NRcRd, where Rc and Rd are independently selected from hydrogen, alkyl or cycloalkyl. The terms “carboxamide” or “carboxamido” as used herein refer to an amino group attached to the parent molecular group through a carbonyl group. The term “carboxamidoalkyl” as used herein refers to a carboxamido group attached to the parent molecular group through an alkyl group. The term “carboxy” as used herein refers to the radical —COOH. The term “carboxyalkyl” as used herein refers to a carboxy group attached to the parent molecular group through an alkyl group. The term “carboxyalkylamino” as used herein refers to a carboxyalkyl group attached to the parent molecular group through an amino group. The term “carboxyalkoxy” as used herein refers to a carboxy group attached to the parent molecular group through an alkoxy group. The term “carboxycarbonyl” as used herein refers to a carboxy group attached to the parent molecular group through a carbonyl group. The term “carboxycycloalkoxy” as used herein refers to a carboxy group attached to the parent molecular group through a cycloalkoxy group. The term “carboxythioalkoxy” as used herein refers to a carboxy group attached to the parent molecular group through a thioalkoxy group. The term “cyano” as used herein refers to the radical —CN. The term “cycloalkyl” as used herein refers to a monovalent saturated cyclic or bicyclic hydrocarbon group of 3-12 carbons derived from a cycloalkane by the removal of a single hydrogen atom. Cycloalkyl groups may be optionally substituted with alkyl, alkoxy, halo, or hydroxy substituents. The term “cycloalkoxy” as used herein refers to a monovalent saturated cyclic or bicyclic hydrocarbon group of 3-12 carbons derived from a cycloalkane by the removal of a single hydrogen atom, linked to the parent molecular group through an oxygen atom. Cycloalkoxy groups may be optionally substituted with alkyl, alkoxy, halo or hydroxy groups. The terms “halo” or “halogen” as used herein refers to F, Cl, Br, or I. The term “haloalkyl” as used herein refers to an alkyl group substituted with one or more halogen atoms. The terms “heterocycle” or “heterocyclyl” represent a 4-, 5-, 6- or 7-membered ring containing one, two or three heteroatoms independently selected from the group consisting of nitrogen, oxygen and sulfur. The 4- and 5-membered rings have zero to two double bonds and the 6- and 7-membered rings have zero to three double bonds. The term “heterocycle” or “heterocyclic” as used herein additionally refers to bicyclic, tricyclic and tetracyclic groups in which any of the above heterocyclic rings is fused to one or two rings independently selected from an aryl ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring or another monocyclic heterocyclic ring. Heterocycles include acridinyl, benzimidazolyl, benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, biotinyl, cinnolinyl, dihydrofuryl, dihydroindolyl, dihydropyranyl, dihydrothienyl, dithiazolyl, furyl, homopiperidinyl, imidazolidinyl, imidazolinyl, imidazolyl, indolyl, isoquinolyl, isothiazolidinyl, isothiazolyl, isoxazolidinyl, isoxazolyl, morpholinyl, oxadiazolyl, oxazolidinyl, oxazolyl, piperazinyl, piperidinyl, pyranyl, pyrazolidinyl, pyrazinyl, pyrazolyl, pyrazolinyl, pyridazinyl, pyridyl, pyrimidinyl, pyrimidyl, pyrrolidinyl, pyrrolidin-2-onyl, pyrrolinyl, pyrrolyl, quinolinyl, quinoxaloyl, tetrahydrofuryl, tetrahydroisoquinolyl, tetrahydroquinolyl, tetrazolyl, thiadiazolyl, thiazolidinyl, thiazolyl, thienyl, thiomorpholinyl, triazolyl, and the like. Heterocyclics also include bridged bicyclic groups where a monocyclic heterocyclic group is bridged by an alkylene group such as and the like. Heterocyclics also include compounds of the formula where X* and Z* are independently selected from —CH2—, —CH2NH—, —CH2O—, —NH— and —O—, with the proviso that at least one of X* and Z* is not —CH2—, and Y* is selected from —C(O)— and —(C(R″)2)v—, where R″ is hydrogen or alkyl of one to four carbons, and v is 1-3. These heterocycles include 1,3-benzodioxolyl, 1,4-benzodioxanyl, 1,3-benzimidazol-2-one and the like. The heterocycle groups of this invention can be optionally substituted with alkyl, halogen, hydroxy or alkoxy substituents. The term “heterocyclylalkyl” as used herein refers to a heterocyclic group attached to the parent molecular group through an alkyl group. The term “heterocyclylalkylamino” as used herein refers to an heterocyclylalkyl group attached to the parent molecular group through an amino group. The term “heterocyclylalkylaminocarbonyl” as used herein refers to a heterocyclylalkylamino group attached to the parent molecular group through a carbonyl group. The term “heterocyclylamino” as used herein refers to a heterocyclyl group attached to the parent molecular group through an amino group. The term “heterocyclylcarbonyl” as used herein refers to a heterocyclyl group attached to the parent molecular group through a carbonyl group. The term “heterocyclylsulfonyl” as used herein refers to a heterocyclyl radical attached to the parent molecular group through an —SO2— group. The term “heterocyclylsulfonylaminocarbonyl” as used herein refers to a heterocyclylsulfonyl group attached to the parent molecular group through an aminocarbonyl group. The term “hydroxyalkanoyl” as used herein refers to a hydroxy radical attached to the parent molecular group through an alkanoyl group. The term “hydroxyalkoxy” as used herein refers to a hydroxy radical attached to the parent molecular group through an alkoxy group. The term “hydroxyalkoxyalkyl” as used herein refers to a hydroxyalkoxy group attached to the parent molecular group through an alkyl group. The term “hydroxyalkyl” as used herein refers to a hydroxy radical attached to the parent molecular group through an alkyl group. The term “hydroxyalkylaminocarbonyl” as used herein refers to a hydroxyalkyl group attached to the parent molecular group through an aminocarbonyl group. The term “perfluoroalkyl” as used herein refers to an alkyl group in which all of the hydrogen atoms have been replaced by fluoride atoms. The term “phenyl” as used herein refers to a monocyclic carbocyclic ring system having one aromatic ring. The phenyl group can also be fused to a cyclohexane or cyclopentane ring. The phenyl groups of this invention can be optionally substituted with alkyl, halogen, hydroxy or alkoxy substituents. The term “pharmaceutically-acceptable prodrugs” as used herein represents those prodrugs of the compounds of the present invention which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals with undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use, as well as the zwitterionic forms, where possible, of the compounds of the invention. The term “prodrug,” as used herein, represents compounds which are rapidly transformed in vivo to the parent compound of the above formula, for example, by hydrolysis in blood. A thorough discussion is provided in T. Higuchi and V. Stella, Pro-drugs as Novel Delivery Systems, Vol. 14 of the A.C.S. Symposium Series, and in Edward B. Roche, ed., Bioreversible Carriers in Drug Design, American Pharmaceutical Association and Pergamon Press, 1987, both of which are incorporated herein by reference. The term “sulfonate” as used herein refers to the radical —SO3H. The term “tetrazole” or “tetrazolyl” as used herein refers to the heterocyclic radical —CN4H. The term “thioalkoxy” as used herein refers to an alkyl group attached to the parent molecular group through a sulfur atom. The term “trans-cinnamyl” as used herein refers to an acrylamido group (aminocarbonylethenyl) attached to the parent molecular group through C-3 of the acrylamido group, such that the aminocarbonyl and the parent molecular group exist in a trans relationship about the ethenyl group. The term “lower” refers to a C1-C6 unit for a particular functionality. For example, “lower alkyl” means C1-C6 alkyl. Use of the above terms is meant to encompass substituted and unsubstituted moieties. Substitution may be by one or more groups such as alcohols, ethers, esters, amides, sulfones, sulfides, hydroxyl, nitro, cyano, carboxy, amines, heteroatoms, lower alkyl, lower alkoxy, lower alkoxycarbonyl, alkoxyalkoxy, acyloxy, halogen, trifluoromethoxy, trifluoromethyl, aralkyl, alkenyl, alkynyl, aryl, carboxyalkoxy, carboxyalkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, alkylheterocyclyl, heterocyclylalkyl, oxo, arylsulfonaminocarbonyl or any of the substituents of the preceding paragraphs or any of those substituents either attached directly or by suitable linkers. The linkers are typically short chains of 1-3 atoms containing any combination of —C—, —C(O)—, —NH—, —S—, —S(O)—, —O—, —C(O)O— or —S(O)—. Rings may be substituted multiple times. The terms “electron-withdrawing” or “electron-donating” refer to the ability of a substituent to withdraw or donate electrons relative to that of hydrogen if hydrogen occupied the same position in the molecule. These terms are well-understood by one skilled in the art and are discussed in Advanced Organic Chemistry by J. March, 1985, pp. 16-18, incorporated herein by reference. Electron withdrawing groups include halo, nitro, carboxyl, lower alkenyl, lower alkynyl, carboxaldehyde, carboxyamido, aryl, quaternary ammonium and trifluoromethyl among others. Electron donating groups include such groups as hydroxy, lower alkyl, amino, lower alkylamino, di(lower alkyl)amino, aryloxy, mercapto, lower alkylthio, lower alkylmercapto and disulfide among others. One skilled in the art will appreciate that the aforesaid substituents may have electron donating or electron withdrawing properties under different chemical conditions. Moreover, the present invention contemplates any combination of substituents selected from the above-identified groups. The most preferred electron donating or electron withdrawing substituents are halo, nitro, alkanoyl, carboxaldehyde, arylalkanoyl, aryloxy, carboxyl, carboxamide, cyano, sulfonyl, sulfoxide, heterocyclyl, guanidine, quaternary ammonium, lower alkenyl, lower alkynyl, sulfonium salts, hydroxy, lower alkoxy, lower alkyl, amino, lower alkylamino, di(lower alkylamino), amine lower mercapto, mercaptoalkyl, alkylthio and alkyldithio. As used herein, the term “composition” is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from a combination of the specified ingredients in the specified amounts. Compounds of the present invention can exist as stereoisomers wherein asymmetric or chiral centers are present. These compounds are designated by the symbols “R” or “S,” depending on the configuration of substituents around the chiral carbon atom. The present invention contemplates various stereoisomers and mixtures thereof. Stereoisomers include enantiomers and diastereomers, and mixtures of enantiomers or diastereomers are designated (±). Individual stereoisomers of compounds of the present invention can be prepared synthetically from commercially available starting materials which contain asymmetric or chiral centers or by preparation of racemic mixtures followed by resolution well-known to those of ordinary skill in the art. These methods of resolution are exemplified by (1) attachment of a mixture of enantiomers to a chiral auxiliary, separation of the resulting mixture of diastereomers by recrystallization or chromatography and liberation of the optically pure product from the auxiliary, (2) salt formation employing an optically active resolving agent, or (3) direct separation of the mixture of optical enantiomers on chiral chromatographic columns. Geometric isomers can also exist in the compounds of the present invention. The present invention contemplates the various geometric isomers and mixtures thereof resulting from the arrangement of substituents around a carbon-carbon double bond or arrangement of substituents around a carbocyclic ring. Substituents around a carbon-carbon double bond are designated as being in the Z or E configuration wherein the term “Z” represents substituents on the same side of the carbon-carbon double bond and the term “E” represents substituents on opposite sides of the carbon-carbon double bond. The arrangement of substituents around a carbocyclic ring are designated as cis or trans wherein the term “cis” represents substituents on the same side of the plane of the ring and the term “trans” represents substituents on opposite sides of the plane of the ring. Mixtures of compounds wherein the substituents are disposed on both the same and opposite sides of plane of the ring are designated cis/trans. As is apparent from the foregoing descriptions, the compounds of Formula I are useful in a variety of forms, i.e., with various substitutions as identified. Examples of particularly desirable compounds are quite diverse, and many are mentioned herein. Compounds of the present invention include, but are not limited to: 1-(6-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidine-3-carboxylic acid, 4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-6-(3-(2H-tetrazol-5-yl)-piperidin-1-yl)-pyrimidine, 4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-6-(4-(2H-tetrazol-5-yl)-piperidin-1-yl)-pyrimidine, (1-(6-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidin-3-yl)-methanol, 2-(1-(6-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidin-4-yl)-ethanol, N-(1-(4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-yl)-acetamide, 1-(4-(4-(2-methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-ol, N-1-(4-(4-(2-methoxy-phenylsulfanyl)-3-tri fluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-yl)-acetamide, N-1-(4-(4-(2-methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-yl)-acetamide, N-(1-(4-(4-(2,3-dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-yl)-acetamide, 4′-(4-(2,3-dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-carboxylic acid and 4′-(4-(2,3-dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-3-carboxylic acid. Abbreviations Abbreviations which have been used in the schemes and the examples which follow are: DCM for methylene dichloride; EWG for electron withdrawing group; NMP for N-methylpyrrolidinone; sat. for saturated; THF for tetrahydrofuran; TFA for trifluoroacetic acid; BINAP for 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl; DMSO for dimethylsulfoxide; MCPBA for meta-chloroperbenzoic acid; DMF for dimethylformamide; TLC for thin layer chromatography; HPLC for high pressure liquid chromatography; APCI for atmospheric pressure chemical ionization; ESI for electrospray ionization; DCI for direct chemical ionization; LFA for lymphocyte function-associated antigen; and ICAM for intercellular adhesion molecule. Pharmaceutical Compositions and Methods of Treatment The present invention also provides pharmaceutical compositions which comprise compounds of the present invention formulated together with one or more pharmaceutically-acceptable carriers. The pharmaceutical compositions may be specially formulated for oral administration in solid or liquid form, for parenteral injection, or for rectal administration. The pharmaceutical compositions of this invention can be administered to humans and other animals orally, rectally, parenterally, intracistemally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, or as an oral or nasal spray. The term “parenteral” administration as used herein refers to modes of administration which include intravenous, intramuscular, intraperitoneal, intrasternal, subcutaneous and intraarticular injection and infusion. Pharmaceutical compositions of this invention for parenteral injection comprise pharmaceutically-acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions as well as sterile powders for reconstitution into sterile injectable solutions or dispersions just prior to use. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils (such as olive oil), and injectable organic esters such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants. These compositions may also contain adjuvants such as preservative, wetting agents, emulsifying agents, and dispersing agents. Prevention of the action of microorganisms may be ensured by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents such as sugars, sodium chloride, and the like, Prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin. In some cases, in order to prolong the effect of the drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle. Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release call be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues. The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium just prior to use. Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically-acceptable excipient or carrier such as sodium citrate or dicalcium phosphate and/or (a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, (b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, and acacia, (c) humectants such as glycerol, (d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, (e) solution retarding agents such as paraffin, (f) absorption accelerators such as quaternary ammonium compounds, (g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, (h) absorbents such as kaolin and bentonite clay, and (I) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents. Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes. The active compounds can also be in micro-encapsulated form, if appropriate, with one or more of the above-mentioned excipients. Liquid dosage forms for oral administration include pharmaceutically-acceptable emulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethyl formamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents. Suspensions, in addition to the active compounds, may contain suspending agents as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar, and tragacanth, and mixtures thereof. Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable non-irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at room temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound. Compounds of the present invention can also be administered in the form of liposomes. As is known in the art, liposomes are generally derived from phospholipids or other lipid substances. Liposomes are formed by mono- or multi-lamellar hydrated liquid crystals that are dispersed in an aqueous medium. Any non-toxic, physiologically-acceptable and metabolizable lipid capable of forming liposomes can be used. The present compositions in liposome form can contain, in addition to a compound of the present invention, stabilizers, preservatives, excipients, and the like. The preferred lipids are the phospholipids and the phosphatidyl cholines (lecithins), both natural and synthetic. Methods to form liposomes are known in the art. See, for example, Prescott, Ed., Methods in Cell Biology, Volume XIV, Academic Press, New York, N.Y. (1976), p. 33 et seq. The compounds of the present invention may be used in the form of pharmaceutically-acceptable salts derived from inorganic or organic acids. By “pharmaceutically-acceptable salt” is meant those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically-acceptable salts are well-known in the art. For example, S. M. Berge, et al. describe pharmaceutically-acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66: 1 et seq. The salts may be prepared in situ during the final isolation and purification of the compounds of the invention or separately by reacting a free base function with a suitable acid. Representative acid addition salts include, but are not limited to acetate, adipate, alginate, citrate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, camphorate, camphorsulfonate, digluconate, glycerophosphate, hemisulfate, heptanoate, hexanoate, fumarate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate (isethionate), lactate, maleate, methanesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate, pamoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, phosphate, glutamate, bicarbonate, p-toluenesulfonate and undecanoate. Also, the basic nitrogen-containing groups can be quaternized with such agents as lower alkyl halides such as methyl, ethyl, propyl, and butyl chlorides, bromides and iodides; dialkyl sulfates like dimethyl, diethyl, dibutyl and diamyl sulfates; long chain halides such as decyl, lauryl, myristyl and stearyl chlorides, bromides and iodides; arylalkyl halides like benzyl and phenethyl bromides and others. Water or oil-soluble or dispersible products are thereby obtained. Examples of acids which may be employed to form pharmaceutically acceptable acid addition salts include such inorganic acids as hydrochloric acid, hydrobromic acid, sulphuric acid and phosphoric acid and such organic acids as oxalic acid, maleic acid, succinic acid and citric acid. Basic addition salts can be prepared in situ during the final isolation and purification of compounds of this invention by reacting a carboxylic acid-containing moiety with a suitable base such as the hydroxide, carbonate or bicarbonate of a pharmaceutically acceptable metal cation or with ammonia or an organic primary, secondary or tertiary amine. Pharmaceutically-acceptable basic addition salts include, but are not limited to, cations based on alkali metals or alkaline earth metals such as lithium, sodium, potassium, calcium, magnesium and aluminum salts and the like and nontoxic quaternary ammonia and amine cations including ammonium, tetramethylammonium, tetraethylaminonium, methylamine, dimethylamine, trimethylamine, triethylamine, diethylamine, ethylamine and the like. Other representative organic amines useful for the formation of base addition salts include ethylenediamine, ethanolamine, diethanolamine, piperidine, piperazine and the like. Dosage forms for topical administration of a compound of this invention include powders, sprays, ointments and inhalants. The active compound is mixed under sterile conditions with a pharmaceutically-acceptable carrier and any needed preservatives, buffers, or propellants which may be required. Opthalmic formulations, eye ointments, powders and solutions are also contemplated as being within the scope of this invention. Actual dosage levels of active ingredients in the pharmaceutical compositions of this invention may be varied so as to obtain an amount of the active compound(s) that is effective to achieve the desired therapeutic response for a particular patient, compositions, and mode of administration. The selected dosage level will depend upon the activity of the particular compound, the route of administration, the severity of the condition being treated, and the condition and prior medical history of the patient being treated. However, it is within the skill of the art to start doses of the compound at levels lower than required for to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved. Generally dosage levels of about 0.1 to about 50 mg, more preferably of about 5 to about 20 mg of active compound per kilogram of body weight per day are administered orally or intravenously to a mammalian patient. If desired, the effective daily dose may be divided into multiple doses for purposes of administration, e.g. two to four separate doses per day. Preparation of Compounds of this Invention The compounds and processes of the present invention may be better understood in connection with the following synthetic schemes which illustrate the methods by which the compounds of the invention can be prepared et Scheme I describes compounds of Formula I which contain oxazol (n=0, Y═N, B═O, D═C). Aryl methyl ketone 1 with the approprite substitution/and a leaving group X reacts with an aryl thiol to give biaryl sulfide 2. Biarylsulfide can be converted into alpha-bromomethyl ketone 3 using a variety of reagents including Bu4NBr3. Condensation of 3 with a urea then gives the desired compounds 4. Another method of preparing compounds of Formula I containing oxazole (n=0, Y═N, B═O, D═C) is illustrated in Scheme 2. Aryl methyl ketones 1 are converted into alpha-hydroxymethyl ketone 5, which then can be reacted with arylthiols to give biaryl sulfide 6. Acid-catalyzed condensation of 6 with KOCN affords 2-hydroxy oxazole 7, which can be converted into 2-chloro-oxazole 8 using POCl3. Displacement of the chloride of 8 with amines gives the desired 2-amino-oxazole 9. Scheme 3 describes the synthesis of a class of compounds of Formula I containing thioazole ring (n=0, Y═N, B═S, D═C). The biaryl sulfide alpha-bromomethyl ketone 3 can be prepared following the procedure outline in Scheme 1. Condensation of 3 with a properly substituted thiourea gives the desired 2-aminothioazole 10. Another class of compounds of Formula I are compounds containing pyrimidine ring, for example 4,6-disubstituted pyrimidines (n=1, Y═C, B═N, Z═C, D═N). Scheme 4 describes one procedure for the preparation of this class of compounds. Reaction of biaryl sulfide methyl ketone 2 with diethyl carbonate under base-catalysis leads to beta-ketoester 11. Condensation of 11 with formamidine gives 4-hydroxy pyrimidine 12, which can be converted into 4-chloropyrimidine 13. Displacement of the chloride of 13 by amines then gives the desired 4-amino-pyrimidine 14. An alternative synthesis of the 4,6-disubstituted pyrimidines is illustrated in Scheme 5. Nucleophilic substitution of aryl fluoride 15 with aryl thiol under base-catalysis gives biaryl sulfide 16. Transmetallation of 16 with n-BuLi/ZnCl2, followed by Pd-catalyzed cross-coupling with 4,6-diiodopyrimidine leads to iodopyrimidine 17. Reaction of 17 with selected amines gives the desired 4-aminopyrimidine 14. Yet another class of compounds of Formula I are compounds containing a pyridine ring, for example 2,4-disubstituted pyridines (n=1, Y═C, B═N, Z═C, D═C). Scheme 6 describes one procedure for the preparation of this class of compounds. Thus, Pd-catalyzed cross-coupling of properly substituted 1-bromo-4-fluoro-benzene 15 and 4-pyridine boronic acid gives compounds 18. Oxidation of 18 with MCPBA leads to pyridinium oxide 19. Displacement of the fluoride of 19 with aryl thiols then affords biarylsulfide 20. Treatment of 20 with POCl3 leads to 2-chloropyridine 21. Finally, reaction of 21 with selected amines gives the desired 2-aminopyridines 22. The compounds and processes of the present invention will be better understood in connection with the following examples which are intended as an illustration of and not a limitation upon the scope of the invention. EXAMPLE 1 1-{4-[4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl]-oxazol-2-yl}-piperidine 23 was synthesized as follows. 1A. First, 1-(4-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-ethanone 24 was prepared as follows. To a solution of o-isopropyl thiophenol (2.46 ml, 15 mmole) and 4-fluoro-3-trifluoromethyl acetophenone (3.0 g, 14.6 mmole) in 100 ml of DMF was added Cs2CO3 (7.15 g, 22 mmole). After stirring for 3 hours, the mixture was filtered and solvent was removed by evaporation. The residue was chromatographed on a silica gel column, eluting with 5% EtOAc in hexane, giving 4.70 g of a white solid 24. Yield: 96.6%. 1H-NMR (CDCl3, 300 MHz) δ1.18 (d, J=6.6 Hz, 6H), 2.56(s, 3H), 3.45 (heptet, J=6.6 Hz, 1H), 6.81 (d, J=8.4 Hz, 1H), 7.26 (m, 1H), 4.48 (d, J=1.8 Hz, 1H), 7.50 (d, J=1.8 Hz, 1H), 7.53 (d, J=8.1 Hz, 1H), 7.79 (d, J=8.1 Hz, 1H), 8.21 (d, J=1.8 Hz, 1H); MS (DCI/NH3) m/z 339 (M+H)+; 356 (M+NH4)+. 1B. Then 2-bromo-1-(4-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-ethanone 25 was prepared as follows. Compound 24 (4.72 g, 14.0 mmole) and tetrabutylammonium tribromide (7.6 g, 15.4 mmole) was dissolved in a mixture of 20 ml of MeOH and 50 ml of DCM. The solution was stirred at ambient temperature overnight. The solvent was then evaporated and the residue was chromatographed on a silica gel column, eluting with 10% EtOAc in hexane. An off-white solid 25 was obtained, 5.9 g, 100%. 1H-NMR (CDCl3, 300 MHz) δ1.18 (d, J=6.9 Hz, 6H), 3.45 (heptate, J=6.9 Hz, 1H). 4.35 (s, 2H), 6.81 (d, J=8.4 Hz, 1H), 7.29 (d.d, J=2.4, 6.3 Hz, 1H), 7.48 (d, J=1.8 Hz, 1H), 7.48-7.56 (m, 3H), 7.81 (d.d, J=2.4, 6.3 Hz, 1H), 7.79 (d, J=8.1 Hz, 1H), 8.24 (d, J=1.8 Hz, 1H); MS (DCI/N-H3) m/z 418 (M+H)+; 434 (M+NH4)+. 1C. A solution of compound 25 (22 mg, 0.05 mmole) and 1-carbamyl piperidine (32 mg, 0.25 mmole) was stirred at 105° C. for 2 hours. DMF was then evaporated and the residue purified on a preparative HPLC system with a C8 reverse-phase column using 10 mM H4NOAc (aq.) and CH3CN as the mobile phase. The product 23 was obtained as a yellow solid (16 mg) from the HPLC fractions by evaporating the solvents on a speedvac. 1H-NMR (CDCl3, 300 MHz) δ1.18 (d, J=6.9 Hz, 6H), 1.5-1.7 (m, 6H), 3.5-3.7 (m, 5H), 6.91 (d, J=8.4 Hz, 1H), 7.34-7.38 (m, 3H), 7.47 (s, 1H), 7.58-7.60 (m, 1H), 7.96 (s, 1H). MS (APCI) m/z 447 (M+H)+. EXAMPLE 2 1-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-oxazol-2-yl)piperidine 26 was synthesized according to the following procedure. 2A. First, 1-(4-fluoro-3-trifluoromethyl-phenyl)-2-hydroxy-ethanone 27 was prepared as follows. To a solution of 1-fluoro-3-trifluoroacetophenone (1.0 g, 5.0 mmole) in acetonitrile (15 ml) and water (3 ml) was added trifluoroacetic acid (0.77 ml, 10 mmole) and bis-(trifluoroacetoxyl)iodobenzene (4.3 g, 10 mmole). The mixture was refluxed for three hours. The solution was concentrated and then extracted with EtOAc (3×30 ml). The combined organic solution was washed with 5% aq. NaHCO3 and dried. After filtration and solvent evaporation, the residue was chromatographed on a silica gel column, eluting with 30% EtOAc in hexane, giving 0.47 g of a white solid 27, 37.8% yield. 1H-NMR (CDCl3, 300 MHz) δ 3.28 (br s, 1H), 4.89 (s, 2H), 7.36 (t, J=9 Hz, 1H). 8.12-8.17 (m, 1H), 8.21 (d, J=6 Hz, 3H); MS (APCI) m/z 223 (M+H)+. 2B. Then 2-hydroxy-1-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-ethanone 28 was prepared as follows. To a solution of compound 27 (0.4 g, 1.8 mmole) and o-isopropylthiophenol (0.31 ml, 1.8 mmole) in DMF (10 ml) was added Cs2CO3 (0.59 g, 1.8 mmole). The mixture was stirred for 10 minutes and EtOAc (30 ml) was added. The mixture was filtered, concentrated and chromatographed on a silica gel column eluting with 30% EtOAc in hexane. The desired product 28 was obtained as an oil, 0.22 g, 34.8%. 1H-NMR (CDCl3, 300 MHz) δ1.17 (d, J=7.0 Hz, 6H), 3.40-3.46 (m, 2H), 4.80 (s, 2H), 6.82 (d, J=8.4 Hz, 1H), 7.27-7.31 (m, 1H), 7.51-7.55 (m, 3H), 7.72 (d, J=8.4 Hz, 1H), 8.17 (s, 1H); MS (DCI/NH3) m/z 355 (M+H)+, 372 (M+NH4)+. 2C. Then 4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3H-oxaxol-2-one 29 was prepared as follows. To a solution of compound 28 (0.22 g, 0.62 mmole) and potassium cyanate 0.25 g, 3.0 mmole) in DMF 5.0 ml) was added 0.5 ml of 4 M HCl in dioxane. The mixture was stirred at ambient temperature for 3 hours and another 0.25 ml of 4 M HCl in dioxane was added. The mixture was stirred for another 10 minutes and then quenched with water (20 ml). The layers were separated and the organic layer was extracted with EtOAc. The combined organic solution was dried, filtered and concentrated. Chromatography of the residue gave the title compound 29 as a yellow solid. 194 mg, 82.6%. 1H-NMR (CDCl3, 300 MHz) δ1.18 (d, J=7.0 Hz, 6H), 3.48 (heptet, J=7.0 Hz, 1H), 6.87 (d, J=8.1 Hz, 1H), 7.11 (s, 1H), 7.27 (m, 2H), 7.44-7.48 (m, 3H), 7.64 (s, 1H), 9.75 (s, 1H); MS (DCI/NH3) m/z 397 (M+NH4)+. 2D. Then, 2-chloro-4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-oxazole 30 was prepared as follows. A solution of compound 29 (197 mg, 0.52 mmole) and diethylphenylamine (0.085 ml) in phosphorus oxychloride (5.0 ml) was refluxed for two hours. The mixture was then concentrated and the residue was quenched with ice-water, followed by extraction with EtOAc. The EtOAc solution was dried, filtered and concentrated. The residue was chromatographed on a 10-g silica gel cartridge, eluting with 30% EtOAc in hexane. The title compound 30 was obtained as a yellow solid. 97 mg, 47.0% yield. 1H-NMR (CDCl3, 300 MHz) δ1.19 (d, J=7.0 Hz, 6H), 3.50 (heptet, J=7.0 Hz, 1H), 6.88 (d, J=8.1 Hz, 1H), 7.20-7.23 (m, 1H), 7.42-7.44 (m, 3H), 7.55 (d, J=8.1 Hz, 1H), 7.90 (s, 1H), 7.97 (s, 1H); MS (DCI/NH3) m/z 398 (M+H), 415 (M+NH4)+. 2E. A solution of compound 30 (20 mg, 0.05 mmole) and 1-acetyl piperazine (19.2 mg, 0.15 mmole) in toluene (1.0 ml) was stirred at 100° C. for five hours. Solvent was evaporated and the residue was purified on a 5-g silica gel cartridge eluting with EtOAc. The title compound 26 was obtained as a white solid. 11.2 mg, 45.8%. 1H-NMR (CDCl3, 300 MHz) δ1.18 (d, J=7.0 Hz, 6H), 2.15(s, 3H), 3.49-3.62 (m, 7H), 3.74 (m, 2H), 6.89 (d, J=8.0 Hz, 1H), 7.15-7.21 (m, 2H), 7.39-7.41 (m, 2H), 7.52 (s, 1H), 7.58 (d, J=8.0 Hz, 1H), 7.96 (s, 1H); MS (APCI) m/z 490(M+H)+. EXAMPLE 3 1-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-thiazol-2-yl)-piperazin-1-yl)-ethanone 31 was synthesized according to the following procedure. A solution of compound 25 (40 mg, 1.0 mmole) and 1-acetyl-4-thiocarbamyl piperazine (19 mg, 0.1 mmole) in 1.0 ml of DMF was stirred at ambient temperature for 16 hours. Then the solvent was evaporated and the residue was purified on a preparative HPLC with a C8 reverse phase column, eluting with a gradient of acetonitrile and 10 mM NH4OAc buffer. The title compound 31 was obtained as a yellow solid. 45 mg, 80.0% yield. 1H-NMR (CDCl3, 300 MHz) δ1.12 (d, J=6.0 Hz, 6H), 2.08 (s, 3H), 3.40-3.49 (m, 3H), 3.55 (br s, 2H), 3.71 (m, 2H), 6.74 (s, 1H), 6.83 (d, J=6.0 Hz, 1H), 7.08-7.13 (m, 1H), 7.31-7.34 (m, 3H), 7.64 (d, J=6.0 Hz, 1H), 8.05 (s, 1H); MS (DCI/NH3) m/z 490 (M+H)+. EXAMPLE 4 (4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-thiazol-2-yl)-(3-methoxy-propyl)-amine 32 was synthesized according to the following procedure. The title compound was prepared according to the procedure of Example 3 from compound 25 (20 mg, 0.05 mmole) and N-(1-methoxy)propyl thiourea (14.8 mg, 0.1 mmole). Yield: 11.7 mg, 50.8%. 1H-NMR (CDCl3, 500 MHz) δ1.18 (d, J=8.5 Hz, 6H), 1.95 (pentaplet, J=8.0 Hz, 2H), 3.36 (s, 3H), 3.42-3.45 (m, 2H), 3.51-3.54 (m, 3H), 6.66 (s, 1H), 6.90 (d, J=10.5 Hz, 1H), 7.17-7.20 (m, 1H), 7.39-7.42 (m, 3H), 7.68 (dd, J=10.5 and 2.0 Hz, 1H), 8.06 (d, J=2.0 Hz, 1H). MS (DCI/NH3) m/z 467 (M+H)+. EXAMPLE 5 1-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-thiazol-2-yl)-piperidine 33 was synthesized according to the following procedure. The title compound was prepared according to the procedure of Example 3 from compound 25 (20 mg, 0.05 mmole) and 1-thiocarbamyl-piperidine (14.4 mg, 0.1 mmole). Yield: 4.9 mg, 10.6%. 1H-NMR (CDCl3, 500 MHz) δ1.18 (d, J=8.5 Hz, 6H), 1.95 (pentet, J=8.0 Hz, 2H), 1.56-1.72 (m, 6H), 3.50-3.57 (m, 5H), 6.70 (s, 1H), 6.91 (d, J=10.5 Hz, 1H), 7.15-7.19 (m, 1H), 7.37-7.40 (m, 3H), 7.78 (dd, J=10.5 and 2.0 Hz, 1H), 8.11 (d, J=2.0 Hz, 1H); MS (DCI/NH3) m/z 463 (M+H)+. EXAMPLE 6 (4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-thiazol-2-yl)-(3-morpholin-4-yl-propyl)-amine 34 was synthesized according to the following procedure. The title compound was prepared according to the procedure of Example 3 from compound 25 (20 mg, 0.05 mmole) and N-[1-(1′-morpholinyl)]propylthiourea (19 mg, 0.1 mmole). Yield: 25.4 mg, 97.7%. 1H-NMR (CDCl3, 500 MHz) δ 1.18 (d, J=8.5 Hz, 6H), 1.86-1.89 (m, 2H), 2.54-2.59 (m, 6H), 3.52 (heptet, J=8.5 Hz, 1H), 3.77-3.79 (m, 4H), 6.68 (s, 1H), 6.91 (d, J=10.5 Hz, 1H), 7.15-7.19 (m, 1H), 7.38-7.40 (m, 3H), 7.69 (dd, J=10.5 and 2.0 Hz, 1H), 8.10 (d, J=2.0 Hz, 1H); MS (DCI/NH3) m/z 522 (M+H)+. EXAMPLE 7 (4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-thiazol-2-yl)-(2-methoxy-ethyl)-amine 35 was synthesized according to the following procedure. The title compound was prepared according to the procedure of Example 3 from compound 25 (20 mg, 0.05 mmole) and N-(1-methoxyl)ethylthiourea (14 mg, 0.1 mmole). Yield: 11 mg, 50%. 1H-NMR (CDCl3, 500 MHz) δ 1.18 (d, J=8.5 Hz, 6H), 3.39 (s, 3H), 3.50-3.55 (m, 3H), 3.62 (t, J=5.5 Hz, 2H), 6.68 (s, 1H), 6.90 (d, J=10.5 Hz, 1H), 7.16-7.21 (m, 1H), 7.38-7.42 (m, 3H), 7.68 (dd, J=10.5 and 2.0 Hz, 1H), 8.07 (d, J=2.0 Hz, 1H); MS (DCI/NH3) m/z 453(M+H)+. EXAMPLE 8 (4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-thiazol-2-yl)-(2-morpholin-4-yl-ethyl)-amine 36 was synthesized according to the following procedure. The title compound was prepared according to the procedure of Example 3 from compound 25 (20 mg, 0.05 mmole) and N-[1-(1′-morpholinyl)]ethyl thiourea (14 mg, 0.1 mmole). Yield: 20.3 mg, 81.2%. 1H-NMR (CDCl3, 500 MHz) δ 1.18 (d, J=8.5 Hz, 6H), 2.56 (br s, 4H), 2.71 (br s, 2H), 3.44 (br s, 2H), 3.52 (heptet, J=8.5 Hz, 1H), 3.76-3.78 (m, 4H), 5.88 (br s, 1H), 6.70 (s, 1H), 6.91 (d, J=10.5 Hz, 1H), 7.15-7.19 (m, 1H), 7.38-7.40 (m, 3H), 7.69 (d, J=10.5 Hz, 1H), 8.12 (d, J=2.0 Hz, 1H); MS (DCI/NH3) m/z 508 (M+H)+. EXAMPLE 9 5 (4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-thiazol-2-yl)-(2-piperidin-1-yl-ethyl)-amine 37 was synthesized according to the following procedure. The title compound was prepared according to the procedure of Example 3 from compound 25 (20 mg, 0.05 mmole) and N-[1-(1′-piperidinyl)]ethyl thiourea (20 mg, 0.1 mmole). Yield: 21 mg, 85.0%. 1H-NMR (CDCl3, 500 MHz) δ 1.18 (d, J=8.5 Hz, 6H), 1.51 (m, 2H), 1.63-1.74 (m, 4H), 2.64 (bs, 4H), 2.80 (t, J=6.5 Hz, 1H), 3.49-3.56 (m, 3H), 4.64 (bs, 1H), 6.68 (s, 1H), 6.90 (d, J=10.5 Hz, 1H), 7.15-7.19 (m, 1H), 7.38-7.41 (m, 3H), 7.69 (d, J=10.5 Hz, 1H), 8.11 (d, J=2.0 Hz, 1H). MS (DCI/NH3) m/z 506 (M+H)+. Example 10 Furan-2-ylmethyl-(4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-thiazol-2-yl)-amine 38 was synthesized according to the following procedure. The title compound was prepared according to the procedure of Example 3 from compound 25 (20 mg, 0.05 mmole) and N-furfuryl thiourea (16 mg, 0.1 mmole). Yield: 9.4 mg, 40.0%. 1H-NMR (CDCl3, 500 MHz) δ 1.18 (d, J=8.5 Hz, 6H), 3.51 (heptet, J=5.5 Hz, 1H), 4.53 (s, 2H), 6.34 (s, 2H), 6.71 (s, 1H), 6.90 (d, J=10.5 Hz, 1H), 7.18-7.21 (m, 1H), 7.38-7.43 (m, 4H), 7.70 (d, J=10.5 Hz, 1H), 8.07 (d, J=2.0 Hz, 1H). MS (DCI/NH3) m/z 475 (M+H)+. EXAMPLE 11 1-(4-(4-(2,3-Dichloro-4-(2-isopropyl-phenylsulfanyl)-phenyl)-thiazol-2-yl)-piperazin-1-yl)-ethanone 39 was synthesized according to the following procedure. 11A. First, 1-(2,3-dichloro-4-(2-isopropyl-phenylsulfanyl)-ethanone 40 was prepared as follows. To a solution of o-isopropyl thiophenol (3.14 g, 25 mmole) and 2,3,4-trichloro-acetophenone (5.9 g, 25 mmole) in DMF (100 ml) was added Na2CO3 (2.65 g, 25 mmole). The reaction was quenched with water (300 ml) after stirring for 50 hours at ambient temperature. The solution was extracted with EtOAc (3×100 ml). The combined EtOAc solution was dried (MgSO4), filtered and concentrated. The residue was chromatographed on a silica gel column, eluting with 10% EtOAc in hexane, giving the title compound 40 as a white solid, 3.4 g, 40.5%. 1H-NMR (CDCl3, 500 MHz) δ 1.19 (d, J=8.5 Hz, 6H), 2.66 (s, 3H), 3.43 (heptaplet, J=8.5 Hz, 1H), 6.42 (d, J=8.4 Hz, 1H), 7.19 (d, J=8.4 Hz, 1H), 7.25-7.30 (m, 1H), 7.48-7.53 (m, 3H). MS (DCI/NH3) m/z 339, 341 (M+H)+; 356, 358 (M+NH4)+. 11 B. Then 2-bromo-1-(2,3-dichloro-4-(2-isopropyl-phenylsulfanyl)-phenyl)-ethanone 41 was prepared as follows. A solution of Br2 (50 mg) in dioxane (1.0 ml) was added to a solution of compound 40 (100 mg, 0.3 mmole) in 2 ml of dioxane. The solution was then stirred for another 10 minutes and concentrated. The residue was dissolved in EtOAc and purified on a 5-g silica gel cartridge, giving the desired product 41 as a white solid. 136 mg, ˜100%. 1H-NMR (CDCl3, 500 MHz) δ 1.19 (d, J=8.5 Hz, 6H), 3.43 (heptet, J=8.5 Hz, 1H), 4.45 (s, 2H), 6.42 (d, J=8.4 Hz, 1H), 7.19 (d, J=8.4 Hz, 1H), 7.25-7.31 (m, 1H), 7.49-7.54 (m, 3H); MS (DCI/NH3) m/z 436 (M+NH4)+. 11C. A solution of compound 41 (30 mg, 0.07 mmole) and 1-thiocarbamyl-4-acetyl piperazine (20.5 mg, 0.11 mmole) in DMF (1.0 ml) was stirred at ambient temperature for two hours. The solvent was evaporated and the residue was purified on a 5-g silica gel cartridge, giving the desired product 39 as a white solid. 23 mg, 65.7%. 1H-NMR (CDCl3, 500 MHz) δ 1.19 (d, J=8.5 Hz, 6H), 2.14 (s, 3H), 3.46-3.60 (m, 7H),), 3.75-3.78 (m, 2H), 6.48 (d, J=8.4 Hz, 1H), 7.09 (s, 1H), 7.21 (m, 1H), 7.44-7.51 (m, 3H), 7.57 (d, J=8.4 Hz, 1H). MS (DCI/NH3) m/z 506 (M+H)+. EXAMPLE 12 1-(4-(2,3-Dichloro-4-(2-isopropyl-phenylsulfanyl)-phenyl)-thiazol-2-yl)-piperadine 42 was synthesized according to the following procedure. The title compound 42 was prepared according to the procedure of Example 11 from compound 41 (30 mg, 0.07 mmole) and 1-thiocarbamyl piperidine. Yield: 21 mg, 65.6%. 1H-NMR (CDCl3, 500 MHz) δ 1.19 (d, J=8.5 Hz, 6H), 1.65 (m, 6H), 3.44-3.52 (m, 5H), ), 6.48 (d, J=8.4 Hz, 1H), 7.01 (s, 1H), 7.21 (m, 1H), 7.44-7.51 (m, 3H), 7.61 (d, J=8.4 Hz, 1H). MS (DCI/NH3) m/z 463 (M+H)+. EXAMPLE 13 4-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-morpholine 43 was synthesized according to the following procedure. 13A First, 1-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-ethanone 44 was prepared as follows. To a solution of 4-fluoro-3-trifluoromethyl-acetophenone (7.00 g, 34.0 mmol) in DMF (100 mL) was added 2-isopropylthiophenol (6.33 g, 37.4 mmol) followed by cesium carbonate (16.6 g, 51.0 mmol). The mixture was stirred at room temperature overnight. The reaction was partitioned between ethyl acetate (250 mL) and water (250 mL). The organic layer was separated, washed with brine (5×250 mL), dried over MgSO4 and filtered. After evaporating the solvent, the crude material was loaded to a silica gel column, eluting with 5% ethyl acetate in hexane to give a colorless oil 44 (11.5 g, 100%). 1H-NMR (CDCl3, 300 MHz) δ 1.17 (d, J=6.7 Hz, 6H), 2.57 (s, 3H), 3.46 (heptete, J=6.8 Hz, 1H), 6.80 (d, J=8.5 Hz, 1H), 7.24-7 29 (m, 1H), 7.45-7.50 (m, 2H), 7.53 (d, J=7.5 Hz, 1H), 7.79 (dd, J=2.0 Hz, 8.5 Hz, 1H), 8.21 (d, J=1.4 Hz, 1H). MS (DCI) m/z 339 (M+H)+; 356 (M+NH4)+. 13B. Then, 3-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3-oxo-propionic acid ethyl ester 45 was prepared as follows. To a solution of compound 44 (11.5 g, 34.0 mmol) in THF (150 mL) was added 60% sodium hydride in mineral oil (1.84 g, 40.8 mmol). The mixture was stirred at room temperature for 10 minutes. Diethyl carbonate (46.5 mL, 340 mmol) was added and the mixture was heated under reflux for 2 hours. 10% HCl aq. (100 mL) was added and the solution was extracted with ethyl acetate (200 mL). The organic layer was separated, washed with brine (5×250 mL), dried over MgSO4 and filtered. The filtrate was concentrated on a rotor-vapor to give a brown oil 45 (10.6 g, 76%); MS (DCI) m/z 411 (M+H)+; 428 (M+NH4)+. 13C. Then, 6-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-ol 46 was prepared as follows. The mixture of compound 45 (10.6 g, 25.8 mmol) and formamidine hydrochloride (10.4 g, 129 mmol) in 20% HOAc in DMF (50 mL) was heated at 120° C. for 3 days. MeOH (50 mL) was added and the resulting solution was purified on a preparative HPLC column, C8 reverse-phase column, eluted with NH4OAc-H2O—CH3CN. Evaporation of solvents gave a white solid 46 (1.40 g, 14%); MS (APCI) m/z 391 (M+H)+. 13D. Then, 4-chloro-6-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidine 47 was prepared as follows. Compound 46 (1.40 g, 3.59 mmol) was treated with POCl3 (30 mL) at 60° C. for an hour. The reaction mixture was concentrated on a rotor-vapor, and the residue was treated with crushed ice (10 g). Water (50 mL) was added. The aqueous solution was then extracted with ethyl acetate (2×50 mL). The combined organic layers were washed with brine (3×50 mL), dried over MgSO4, filtered and concentrated. The crude product was purified by chromatography to give a brown oil 47 (0.74 g, 51%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.7 Hz, 6H). 3.50 (heptet, J=6.8 Hz, 1H), 6.89 (d, J=8.5 Hz, 1H), 7.24-7.28 (m, 1H), 7.46-7.50 (m, 2H), 7.54 (d, J=7.6 Hz, 1H), 7.68 (s, 1H), 7.93 (d, J=8.4 Hz, 1H), 8.38 (s, 1H), 9.00(s, 1H). MS (DCI) m/z 409, 411 (M+H)+. 13E. To a solution of compound 47 (0.015 g, 0.0367 mmol) in DMF (1.0 mL) was added morpholine followed by potassium carbonate (0.015 g, 0.109 mmol). The reaction mixture was heated at 80° C. for 16 hours. The solid was removed through filtration, and the filtrate was directly purified by preparative HPLC, to give a yellow solid, 43 (0.012 g, 72%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 3.51 (heptet, J=6.8 Hz, 1H), 3.69 (t, J=4.9 Hz, 4H), 3.81 (t, J=4.9 Hz, 4H), 6.80 (s, 1H), 6.90 (d, J=8.5 Hz, 1H), 7.20-7.24 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.48 (d, J=7.6 Hz, 1H), 7.87 (d, J=8.2 Hz, 1H), 8.26 (s, 1H), 8.67(s, 1H). MS (APCI) m/z 460 (M+H)+. EXAMPLE 14 1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidin-4-ol 48 was synthesized according to the following procedure. The title compound 48 was prepared according to the procedures of Example 13E, substituting morpholine with 4-hydroxypiperidine. A yellow solid was obtained (0.012 g, 71%). 1H-NMR (DMSO, 400 MHz) δ 1.14 (d, J=7.2 Hz, 6H), 1.48-1.52 (m, 2H), 1.87-1.90 (m, 2H), 3.10-3.70 (m, 4H, overlapping with the solvent H2O peak), 4.38-4 42 (m. 2H), 6.90 (d, J=8.4 Hz, 1H), 7.32-7.35 (m, 2H), 7.47-7.55 (m, 3H), 8.25 (d, J=8.2 Hz, 1H), 8.50 (s, 1H), 8.55 (s, 1H); MS (APCI) m/z 474 (M+H)+. EXAMPLE 15 4-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-2,6-dimethyl-morpholine 49 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 2,6-dimethylmorpholine. A yellow solid 49 was obtained (0.013 g, 73%). 1H-NMR (CDCl3, 400 MHz) δ 1.18 (d, J=7.2 Hz, 6H), 1.28 (d, J=6.4 Hz, 6H), 2.65 (dd, J=2.1, 10.6 Hz, 2H), 3.52 (heptet, J=6.8 Hz, 1H), 3.65-3.70 (m, 2H), 4.24 (br d, J=11.5 Hz, 2H), 6.78 (s, 1H), 6.90 (d, J=8.4 Hz, 1H), 7.20-7.24 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.48 (d, J=7.7 Hz, 1H), 7.87 (d, J=8.5 Hz, 1H), 8.27 (s, 1H), 8.66(s, 1H). MS (APCI) m/z 488 (M+H)+. EXAMPLE 16 1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidine-3-carboxylic acid amide 50 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with nipecotamide. A yellow solid 50 was obtained (0.014 g, 74%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.54-1.66 (m 1H), 1.76-1.84 (m, 1H), 1.96-2.12 (m, 2H), 2.46-2.53 (m, 1H), 3.27-3.35 (m, 1H), 3.51 (heptaplet, J=6.6 Hz, 1H), 3.70-3.76 (m, 1H), 3.94-4.01 (br, 1H), 4.20-4.26 (m, 1H), 5.44 (s, br, 1H), 6.10 (s, br, 1H), 6.84 (s, 1H), 6.90 (d, J=8.1 Hz, 1H), 7.20-7.25 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.48 (d, J=7.6 Hz, 1H), 7.85 (d, J=8.0 Hz, 1H), 8.28 (s, 1H), 8.64 (s, 1H). MS (APCI) m/z 501 (M+H)+. EXAMPLE 17 1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidine-4-carboxylic acid amide 51 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with iso-nipecotamide. A yellow solid 51 was obtained (0.013 g, 69%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.71-1.82 (m, 2H), 1.97-2.04 (m, 2H), 2.44-2.53 (m, 1H), 3.07 (t, J=12.5 Hz, 2H), 3.52 (heptet, J=6.8 Hz, 1H), 4.49 (d, J=13.6 Hz, 2H), 5.49 (br s, 1H), 5.59 (br s, 1H), 6.83 (s, 1H), 6.90 (d, J=8.5 Hz, 1H), 7.20-7.24 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.48 (d, J=7.6 Hz, 1H), 7.86 (d, J=8.5 Hz, 1H), 8.26 (s, 1H), 8.65 (s, 1H); MS (APCI) m/z 501 (M+H)+. EXAMPLE 18 N-Ethyl-N-1-(6-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-pyrrolidin-3-yl)-acetamide 52 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 3-(N-acetyl-N-ethylamino)pyrrolidine. A yellow solid 52 was obtained (0.014 g, 72%). MS (APCI) m/z 529 (M+H)+. EXAMPLE 19 1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidine-3-carboxylic acid ethyl ester 53 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with ethyl nipecotate. A yellow solid 53 was obtained (0.011 g, 56%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.7 Hz, 6H), 1.25 (t, J=7.2 Hz, 3H), 1.57-1.60 (m, 1H), 1.79-1.88 (m, 2H), 2.10-2.14 (m, 1H), 2.54-2.59 (m, 1H), 3.21-3.38 (m, 1H), 3.35-3.40 (m, 1H), 3.52 (heptet, J=6.8 Hz, 1H), 4.11-4.18 (m, 1H), 4.16 (q, J=7.2, 2H), 4.38-4.44 (m, 1H), 6.86 (s, 1H), 6.90 (d, J=8.5 Hz, 1H), 7.20-7.25 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.48 (d, J=7.6 Hz, 1H), 7.86 (d, J=8.4 Hz, 1H), 8.28 (s, 1H), 8.65 (s, 1H); MS (APCI) m/z 530 (M+H)+. EXAMPLE 20 1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidine-4-carboxylic acid ethyl ester 54 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with ethyl isonipecotate. A yellow solid 54 was obtained (0.012 g, 61%). 1H-NMR (CDCl3, 400 MHz) δ 1.19(d, J=6.8 Hz, 6H), 1.27 (t, J=7.2 Hz, 3H), 1.71-1.81 (m, 2H), 2.00-2.04 (m, 2H), 2.58-2.65 (m, 1H), 3.11-3.18 (m, 2H), 3.52 (heptet, J=6.8 Hz, 1H), 4.16 (q, J=7.2 Hz, 2H), 4.32-4.38 (m, 2H), 6.82 (s, 1H), 6.90 (d, J=8.5 Hz, 1H), 7.20-7.24 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.48 (d, J=7.6 Hz, 1H), 7.86 (d, J=8.5 Hz, 1H), 8.26 (s, 1H), 8.65 (s, 1H); MS (APCI) m/z 530 (M+H)+. EXAMPLE 21 4-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperazine-1-carboxylic acid ethyl ester 55 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with ethyl piperazine-1-carboxylate. A yellow solid 55 was obtained (0.019 g, 96%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.29 (t, J=7.2 Hz, 3H), 3.51 (heptaplet, J=6.8 Hz, 1H), 3.59-3.62 (m, 4H), 3.71-3.75 (m, 4H), 4.19 (q, J=7.2 Hz, 2H), 6.81 (s, 1H), 6.90 (d, J=8.5 Hz, 1H), 7.19-7.25 (m, 1H), 7.42-7.45 (m, 2H), 7.46-7.50 (m, 1H), 7.86 (d, J=8.5 Hz, 1H), 8.26 (s, 1H), 8.67 (s, 1H); MS (APCI) m/z 531 (M+H)+. EXAMPLE 22 4-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperazin-1-yl)-acetic acid ethyl ester 56 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 1-(ethoxycarbonylmethyl)piperazine. A yellow solid 56 was obtained (0.007 g, 37%). 1H-NMR (CDCl3, 400 MHz) δ 1.18 (d, J=6.8 Hz, 6H), 1.29 (t, J=7.2 Hz, 3H), 2.70 (br, 4H), 3.28 (s, 2H), 3.51 (heptet, J=6.8 Hz, 1H), 3.78 (br m, 4H), 4.21 (q, J=7.2 Hz, 2H), 6.80 (s, 1H), 6.90 (d, J=8.5 Hz, 1H), 7.21-7.27 (m, 1H), 7.42-7.45 (m, 2H), 7.46-7.50 (m, 1H), 7.86 (d, J=8.5 Hz, 1H), 8.26 (s, 1H), 8.65 (s, 1H); MS (APCI) m/z 545 (M+H)+. EXAMPLE 23 (3-Imidazol-1-yl-propyl)-(6-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-amine 57 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 1-(3-aminopropyl)imidazole. A yellow solid 57 was obtained (0.010 g, 54%). 1H-NMR (CDCl3, 400 MHz) δ 1.18 (d, J=6.8 Hz, 6H), 2.16 (p, J=6.8 Hz, 2H), 3.36-3.41 (m, 2H), 3.51 (heptet, J=6.8 Hz, 1H), 4.10 (t, J=6.7, 2H), 6.58 (s 1H), 6.89 (d, J=8.5 Hz, 1H), 6.95 (s, 1H), 7.09 (s, 1H), 7.21-7.25 (m, 1H), 7.43-7.46 (m 2H), 7.49 (d, J=7.6 Hz, 1H), 7.60 (s, 1H), 7.83 (d, J=8.4 Hz, 1H), 8.26 (s, 1H), 8.58 (s, 1H). MS (APCI) m/z 498 (M+H)+. EXAMPLE 24 1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidine-4-carboxylic acid 58 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with isonipecotic acid. A yellow solid 58 was obtained (0.004 g, 24%). 1H-NMR (DMSO, 400 MHz) δ 1.14 (d, J=7.2 Hz, 6H), 1.48-1.52 (m, 2H), 1.87-1.90 (m, 2H), 3.10-3.70 (m, 4H, overlapping with the solvent H2O peak), 4.38-4.42 (m, 2H), 6.90 (d, J=8.4 Hz, 1H), 7.31-7.35 (m, 2H), 7.47-7.55 (m, 3H), 8.25 (d, J=8.2 Hz, 1H), 8.50 (s, 1H), 8.55 (s, 1H). MS (APCI) m/z 502 (M+H)+. EXAMPLE 25 1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidine-3-carboxylic acid 59 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with nipecotic acid. A yellow solid 59 was obtained (0.011 g, 57%). 1H-NMR (DMSO, 400 MHz) δ 1.14 (d, J=7.2 Hz, 6H), 1.43-1.46 (m, 2H), 1.63-1.72 (m, 2H), 1.97-1.20 (m, 1H), 2.36-2.41 (m, 1H), 3.10-3.70 (m, 2H, overlapping with the solvent H2O peak), 4.24-4.28 (m, 1H), 4.46-4.52 (m, 1H), 6.90 (d, J=8.4 Hz, 1H), 7.30-7.33 (m, 1H), 7.38 (s, 1H), 7.46 (d, J=8.0 Hz, 1H), 7.48-7.57 (m, 2H), 8.25 (d, J=8.2 Hz, 1H), 8.50 (s, 1H), 8.55 (s, 1H); MS (APCI) m/z 502 (M+H)+. EXAMPLE 26 4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidine-3-carboxylic acid 60 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 1-(2-pyridyl)piperazine. A yellow solid 60 was obtained (0.013 g, 65%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 3.52 (heptet, J=6.8 Hz, 1H), 3.71 (t, J=5.3 Hz, 4H), 3.87 (t, J=5.3 Hz, 4H), 6.66-6.69 (m, 2H), 6.84 (s, 1H), 6.90 (d, J=8.5 Hz, 1H), 7.21-7.25 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.47-7.55 (m, 2H), 7.88 (d, J=8.5 Hz, 1H), 8.21-8.23 (m, 1H), 8.29 (s, 1H), 8.68 (s, 1H); MS (APCI) m/z 536 (M+H)+. EXAMPLE 27 1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidine-3-carboxylic acid diethylamide 61 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with N,N-diethyl nipecotamide. A yellow solid 61 was obtained (0.014 g, 69%). 1H-NMR (CDCl3, 400 MHz) δ 1.13 (t, J=7.2 Hz, 3H), 1.19 (d, J=6.8 Hz, 6H), 1.21 (t, J=7.2 Hz, 3H), 1.52-1.59 (m, 1H), 1.82-1.99 (m, 3H), 2.61-2.69 (m, 1H), 3.30 (m, 1H), 3.15 (m, 1H), 3.32-3.45 (m, 4H), 3.52 (heptet, J=6.8 Hz, 1H), 4.35-4.41 (br, 1H), 4.58-4.65 (br, 1H), 6.82 (s, 1H), 6.90 (d, J=8.5 Hz, 1H), 7.21-7.24 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.48 (d, J=7.7 Hz, 1H), 7.85 (d, J=8.5 Hz, 1H), 8.26 (s, 1H), 8.63 (s, 1H); MS (DCI) m/z 557 (M+H)+. EXAMPLE 28 4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-6-(3-(2H-tetrazol-5-yl)-piperidin-1-yl)-pyrimidine 62 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 3-(5′-tetrazolyl)-piperidine. A yellow solid 62 was obtained (0.004 g, 21%). 1H-NMR (CDCl3, 400 MHz) δ 1.18 (d, J=6.8 Hz, 6H), 1.45-1.56 (m, 1H), 1.68-1.77 (m, 1H), 2.17-2.27 (m, 1H), 2.51-2.59 (m, 1H), 3.42-3.51 (m, 2H), 3.50 (heptaplet, J=6.8 Hz, 1H), 3.66-3.73 (m, 1H), 3.92-3.98 (m, 1H), 4.51-4 57 (m, 1H), 6.86-6.91 (m, 2H), 7.21-7.28 (m, 1H), 7.43-7.51 (m, 3H), 7.85 (d, J=8.5 Hz, 1H), 8.23 (s, 1H), 8.78 (s, 1H); MS (APCI) m/z 526 (M+H)+. EXAMPLE 29 4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-6-(4-(2H-tetrazol-5-yl)-piperidin-1-yl)-pyrimidine 63 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 4-(5′-tetrazolyl)-piperidine. A yellow solid 63 was obtained (0.008 g, 40%). 1H-NMR (CDCl3, 400 MHz) δ 1.17 (d, J=6.8 Hz, 6H), 1.78-182 (m, 2H), 2.10-2.15 (m, 2H), 3.11-3.19 (m, 2H), 3.29-3.37 (m, 1H), 3.49 (heptet, J=6.8 Hz, 1H), 4.43-4.49 (br, 2H), 6.82 (s, 1H), 6.88 (d, J=8.5 Hz, 1H), 7.18-7.25 (m, 1H), 7.42 (s, 1H), 7.43 (s, 1H), 7.46 (d, J=7.7 Hz, 1H), 7.81 (d, J=8.5 Hz, 1H), 8.21 (s, 1H), 8.61 (s, 1H); MS (APCI) m/z 526 (M+H)+. EXAMPLE 30 (1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidin-3-yl)-methanol 64 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 3-hydroxymethyl piperidine. A yellow solid 64 was obtained (0.012 g, 67%). 1H-NMR (CDCl3, 400 MHz) δ 1.17 (d, J=6.8 Hz, 6H), 1.78-182 (m, 2H), 2.10-2.15 (m, 2H), 3.11-3.19 (m, 2H), 3.29-3.37 (m, 1H), 3.49 (heptaplet, J=6.8 Hz, 1H), 4.43-4.49 (br, 2H), 6.82 (s, 1H), 6.88 (d, J=8.5 Hz, 1H), 7.18-7.25 (m, 1H), 7.42 (s, 1H), 7.43 (s, 1H), 7.46 (d, J=7.7 Hz, 1H), 7.81 (d, J=8.5 Hz, 1H), 8.21 (s, 1H), 8.61 (s, 1H); MS (APCI) m/z 488 (M+H)+. EXAMPLE 31 2-(1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-piperidin-4-yl)-ethanol 65 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 4-(2′-hydroxyethyl)-piperidine. A yellow solid 65 was obtained (0.013 g. 68%). 1H-NMR (DMSO, 400 MHz) δ 1.06-1.09 (m, 1H), 1.14 (d, J=7.2 Hz, 6H), 1.37-1.38 (m, 2H), 1.73-1.75 (m, 3H), 2.90 (t, J=10.8 Hz, 1H), 3.74-3.48 (m, 3H), 4.35-4.37 (m, 1H), 4.51-4.54 (m, 1H), 6.90 (d, J=8.4 Hz, 1H), 7.30-7.33 (m, 2H), 7.46 (d, J=8.0 Hz, 1H), 7.48-7.57 (m, 2H), 8.25 (d, J=8.2 Hz, 1H), 8.50 (s, 1H), 8.53 (s, 1H); MS (APCI) m/z 502 (M+H)+. EXAMPLE 32 N-(1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-pyrrolidin-3-yl)-acetamide 66 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 3-acetamidopyrrolidine. A yellow solid 66 was obtained (0.012 g, 67%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 2.00 (s, 3H), 2.02-2.08 (m, 1H), 2.30-2.39 (m, 1H), 3.38-3.52 (br, 1H), 3.51 (heptet, J=6.8 Hz, 1H), 3.60-3.70 (br, 1H), 3.78-3.87 (m, 1H), 4.58-4.66 (m, 1H), 5.62-5.68 (m, 1H), 6.59 (s, 1H), 6.90 (d, J=8.5 Hz, 1H), 7.20-7.28 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.48 (d, J=7.7 Hz, 1H), 7.88 (d, J=8.5 Hz, 1H), 8.28 (s, 1H), 8.65 (s, 1H); MS (APCI) m/z 501 (M+H)+. EXAMPLE 33 4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-6-(2-methoxymethyl-pyrrolidin-1-yl)-pyrimidine 67 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with (R)-(+)-2-(methoxymethyl)pyrrolidine. A yellow solid 67 was obtained (0.011 g, 63%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 2.01-2.15 (m, 4H), 3.36 (s, 3H), 3.38-3.62 (m, 4H), 3.52 (heptet, J=6.8 Hz, 1H), 4.36 (s, br, 1H), 6.68 (s, 1H), 6.91 (d, J=8.5 Hz, 1H), 7.18-7.26 (m, 1H), 7.43 (s, 1H), 7.44 (s, 1H), 7.47 (d, J=7.7 Hz, 1H), 7.86 (d, J=8.5 Hz, 1H), 8.28 (s, 1H), 8.64 (s, 1H); MS (APCI) m/z 488 (M+H)+. EXAMPLE 34 1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-pyrrolidin-3-ol 68 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with (R)-(+)-3-pyrrolidinol. A yellow solid 68 was obtained (0.012 g, 73%). 1H-NMR (DMSO, 400 MHz) δ1.14 (d, J=7.2 Hz, 6H), 1.80-2.10 (m, 2H), 3.43 (heptet, 7.2 Hz, 1H), 3.54 (br s, 3H), 4.22 (m, 1H), 5.10 (m, 1H), 6.92 (d, J=8.4 Hz, 1H), 7.01 (s, 1H), 7.31-7.35 (m, 1H), 7.47 (d, J=8.0 Hz, 1H), 7.48-7.57 (m, 2H), 8.25 (d, J=8.2 Hz, 1H), 8.50 (s, 1H), 8.52 (s, 1H); MS (APCI) m/z 460 (M+H)+. EXAMPLE 35 (1-(6-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-pyrrolidin-3-yl)-carbamic acid tert-butyl ester 69 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with 3-(tert-butoxycarbonylamino)pyrrolidine. A yellow solid 69 was obtained (0.015 g, 72%). 1H-NMR (DMSO, 400 MHz) δ1.14 (d, J=7.2 Hz, 6H), 1.39 (s, 9H), 1.90 (br s, 1H), 2.18 (br s, 1H), 3.43 (heptet, 7.2 Hz, 1H), 3.54 (br s, 4H), 4.18 (m, 1H), 6.91 (d, J=8.4 Hz, 1H), 7.02 (s, 1H), 7.22 (br s, 1H), 7.31-7.35 (m, 1H), 7.47 (d, J=8.0 Hz, 1H), 7.48-7.57 (m, 2H), 8.25 (d, J=8.2 Hz, 1H), 8.50 (s, 1H), 8.52 (s, 1H); MS (APCI) m/z 459 (M+H)+. EXAMPLE 36 Isopropyl-(6-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-methyl amine 70 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with N-methylisopropylamine. A yellow solid 70 was obtained (0.009 g, 57%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.22 (d, J=6.8 Hz, 6H), 2.93 (s, 3H), 3.52 (heptaplet, J=6.8 Hz, 1H), 6.69 (s, 1H), 6.91 (d, J=8.5 Hz, 1H), 7.19-7.24 (m, 1H), 7.42 (s, 1H), 7.43 (s, 1H), 7.48 (d, J=7.7 Hz, 1H), 7.86 (d, J=8.5 Hz, 1H), 8.27 (s, 1H), 8.64 (s, 1H). MS (APCI) m/z 446. (M+H)+. EXAMPLE 37 Ethyl-(6-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyrimidin-4-yl)-methyl-amine 71 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 13E, substituting morpholine with N-ethylmethylamine. A yellow solid 71 was obtained (0.009 g, 56%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H). 1.21 (t, J=7.2 Hz, 3H), 3.11 (s, 3H), 3.52 (heptet, J=6.8 Hz, 1H), 3.64 (q, J=7.2 Hz, 2H), 6.68 (s, 1H), 6.91 (d, J=8.5 Hz, 1H), 7.19-7.24 (m, 1H), 7.42 (s, 1H), 7.43 (s, 1H), 7.47 (d, J=7.7 Hz, 1H), 7.86 (d, J=8.5 Hz, 1H), 8.28 (s, 1H), 8.64 (s, 1H). MS (APCI) m/z 432 (M+H)+. EXAMPLE 38 1-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-ol 72 was synthesized according to the following procedure. 38A. First, 4-(4-fluoro-3-trifluoromethyl-phenyl)-pyridine 73 was prepared as follows. To a suspension of pyridine-4-boronic acid (2.59 g, 21.1 mmol) in 1-propanol (60 mL) was added 5-bromo-2-fluorobenzotrifluoride (5.12 g, 21.1 mmol) and triphenylphosphine (0.160 g, 0.610 mmol), followed by sodium carbonate in water (2.0 M, 12 mL). The mixture was purged with nitrogen gas for 10 minutes. To it was added palladium(II) acetate (0.044 g, 0.196 mmol) and it was then heated under reflux for 4 hours. The reaction mixture was partitioned between ethyl acetate (200 mL) and water (200 mL). The organic layer was separated, washed with brine (3×200 mL), dried over MgSO4, then filtered. After evaporating the solvent, the crude material was loaded to a silica gel column, eluting with 60% ethyl acetate in hexane to give a white solid 73 (2.73 g, 54%). 1H-NMR (CDCl3, 400 MHz) δ 7.34-7.42 (m, 1H), 7.61-7.65 (m, 2H), 7.80-7.93 (m, 2H), 8.73-8.84 (m, 2H); MS (DCI) m/z 242, 243 (M+H)+. 38B. Then, 4-(4-fluoro-3-trifluoromethyl-phenyl)-pyridine-1-oxide 74 was prepared as follows. To a solution of compound 73 (2.49 g, 10.3 mmol) in dichloromethane (10 mL) was added methyltrioxorhenium(VII) (0.128 g, 0.515 mmol), followed by hydrogen peroxide in water (30%, 5.15 mL). The reaction mixture was stirred at room temperature for 16 hours. Manganese (IV) oxide (0.050 g) was added. The mixture was stirred for another 30 minutes. The organic layer was separated. The aqueous layer was extracted with more dichloromethane (2×10 mL). The combined organic phase was washed with brine (3×30 mL), dried over MgSO4 and filtered. After evaporating the solvent, the crude material was loaded to a silica gel column, eluting with 10% methanol in ethyl acetate to give a white solid 74 (2.51 g, 94%). 1H-NMR (CDCl3, 400 MHz) δ 7.35 (t, J=9.3 Hz, 1H), 7.49 (d, J=7.2 Hz, 2H), 7.74-7.82 (m, 2H), 8.30 (d, J=7.1 Hz, 2H); MS (DCI) m/z 258, 259 (M+H)+. 38C. Then, 4-(4-(2-isopropyl-phenylsulfanyl-3-trifluoromethyl-phenyl)-pyridine-1-oxide 75 was prepared as follows. A solution of compound 74 (2.51 g, 9.76 mmol) in dimethylacetamide (100 mL) was purged with nitrogen gas for 10 minutes. To it was added cesium carbonate (3.80 g, 11.7 mmol), followed by 2-isopropylthiophenol (4.90 mL, 29.3 mmol). The reaction was heated at 100° C. for 16 hours. The mixture was partitioned between ethyl acetate (200 mL) and water (200 mL). The organic layer was separated, washed with brine (5×200 mL), dried over MgSO4 and then filtered. After evaporating the solvent, the crude material was loaded to a silica gel column, eluting with 10% methanol in ethyl acetate to give a white solid 75 (3.19 g 84%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 3.51 (heptaplet, J=6.8 Hz, 1H), 6.90 (d, J=8.1 Hz, 1H), 7.22-7.28 (m, 1H), 7.44-7.51 (m, 6H), 7.84 (d, J=2.1 Hz, 1H), 8.24 (d, J=7.4 Hz, 2H); MS (DCI) m/z 390 (M+H)+. 38D. Then, 2-chloro-4-(4-(2-isopropyl-phenylsulfanyl-3-trifluoromethyl-phenyl)-pyridine 76 was prepared as follows. Compound 75 (3.19 g, 8.19 mmol) was treated with POCl3 (50 mL) at 100° C. for 10 hours. The reaction mixture was concentrated on a rotovap, and the residue was treated with crushed ice (20 g). Water (100 mL) was added, the aqueous solution was then extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with brine (3×100 mL), dried over MgSO4, filtered and concentrated. The crude product was purified by chromatography to give the title compound 76 as a brown oil (2.74 g, 82%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 3.51 (heptet, J=6.8 Hz, 1H), 6.91 (d, J=8.5 Hz, 1H), 7.25-7.28 (m, 1H), 7.37 (dd, J=1.7 Hz, 5.1 Hz, 1H), 7.45-7.52 (m, 5H), 7.87 (d, J=2.0 Hz, 1H), 8.43 (d, J=5.4 Hz, 1H). MS (DCI) m/z 408, 409, 410 (M+H)+. 38E. To a solution of compound 76 (0.024 g, 0.0588 mmol) in DMSO (0.50 mL) was added 3-hydroxylpyrrolidine (0.0256 g, 0.294 mmol). The reaction mixture was heated at 140° C. for 16 hours. It was then cooled down to room temperature. Methanol was added to the reaction mixture and then purified by preparative HPLC to give a yellow solid 72 (0.0256 g, 95%). 1H-NMR (CDCl3, 400 MHz) δ 1.20 (d, J=6.8 Hz, 6H), 2.14-2.22 (m, 1H), 2.25-2.32 (m, 1H), 2.65 (s, 1H), 3.50 (heptet, J=6.8 Hz, 1H), 3.75-3.83 (m, 2H), 3.86-3.94 (m, 2H), 4.73 (s, 1H), 6.78 (s, 1H), 6.91 (d, J=8.0 Hz, 2H), 7.25-7.29 (m, 1H), 7.45-7.52 (m, 4H), 7.85 (d, J=1.5 Hz, 1H), 8.10 (d, J=7.0 Hz, 1H); MS (APCI) m/z 459 (M+H)+. EXAMPLE 39 (1-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-2-yl)-methanol 77 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with (R)-2-(hydroxymethyl)pyrrolidine. A yellow solid 77 was obtained (0.0216 g, 78%). 1H-NMR (CDCl3, 400 MHz) δ 1.20 (d, J=6.8 Hz, 6H), 2.06-2.11 (m, 2H), 2.15-2.21 (m, 2H), 3.47-3.53 (m, 2H), 3.64-3.69 (m, 1H), 3.71-3.76 (m, 2H), 4.63 (s, 1H), 6.79 (s, 1H), 6.89-6.93 (m, 2H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.85 (d, J=1.8 Hz, 1H), 8.10 (d, J=6.9 Hz, 1H); MS (APCI) m/z 473 (M+H)+. Example 40 4′-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridiny-4-ol 78 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with 4-hydroxypiperidine. A yellow solid 78 was obtained (0.0255 g, 92%). 1H-NMR-(CDCl3, 400 MHz) δ 1.20 (d, J=6.8 Hz, 6H), 1.77-1.85 (m, 2H), 2.02-2.09 (m, 2H), 3.49 (heptet, J=6.8 Hz, 1H), 3.68-3.74 (m, 2H), 3.99-4.06 (m, 2H), 4.12-4.16 (m, 1H), 6.90 (d, J=8.0 Hz, 1H), 6.93 (d, J=6.6 Hz, 1H), 6.98 (s, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.85 (s, 1H), 8.19 (d, J=6.6 Hz, 1H); MS (APCI) m/z 473 (M+H)+. EXAMPLE 41 4-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazine-1-carbaldehyde 79 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with 1-formylpiperazine. A yellow solid 79 was obtained (0.0073 g, 26%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 3.50 (heptet, J=6.8 Hz, 1H), 3.62-3.66 (m, 2H), 3.69-3.73 (m, 2H), 3.75-3.78 (m, 2H), 3.89-3.93 (m, 2H), 6.92 (d, J=8.5 Hz, 1H), 6.95 (s, 1H), 7.03 (d, J=6.2 Hz, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.85 (d, J=1.8 Hz, 1H), 8.16 (s, 1H), 8.29 (d, J=6.3 Hz, 1H); MS (APCI) m/z 486 (M+H)+. EXAMPLE 42 1-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-2-carboxylic acid 80 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with (D)-proline. A yellow solid 80 was obtained (0.0232 g, 81%). 1H NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 2.13-2.34 (m, 4H), 2.47-2.53 (br, 1H), 3.50 (heptet, J=6.8 Hz, 1H), 3.61 (br, 1H), 3.85 (br, 1H), 4.95 (br, 1H), 6.81 (s, 1H), 6.88-6.94 (m, 2H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.84 (s, 1H), 8.03 (d, J=6.6 Hz, 1H). MS (APCI) m/z 487 (M+H)+. EXAMPLE 43 (4′-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-yl)-methanol 81 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with 4-hydroxymethylpiperidine. A yellow solid 81 was obtained (0.0252 g, 88%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.41-1.50 (m, 2H), 1.86-1.94 (m, 1H), 1.99 (d, J=13.6 Hz, 2H), 3.27 (t, J=11.7 Hz, 2H), 3.50 (heptet, J=6.8 Hz, 1H), 3.57 (d, J=5.8 Hz, 2H), 4.36 (d, J=13.2 Hz, 2H), 6.85-6.94 (m, 2H), 6.97 (s, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.84 (s, 1H), 8.22 (d, J=6.6 Hz, 1H); MS (APCI) m/z 487 (M+H)+. EXAMPLE 44 N-(1-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-yl)-acetamide 82 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with (3R)-(+)-3-acetamidopyrrolidine. A yellow solid 82 was obtained (0.0243 g, 83%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.97 (s, 3H), 2.22-2.28 (m, 1H), 2.31-2.37 (m, 1H), 3.50 (heptet, J=6.8 Hz, 1H), 3.72-3.80 (m, 2H), 3.81-3.86 (m, 1H), 3.91-3.99 (m, 1H), 4.61-4.66 (m, 1H), 6.78 (s, 1H), 6.90 (d, J=8.4 Hz, 1H), 6.93 (d, J=5.9 Hz, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.86 (d, J=1.5 Hz, 1H), 8.06 (d, J=6.6 Hz, 1H); MS (APCI) m/z 500 (M+H)+. EXAMPLE 45 N-(1-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-yl)-acetamide 83 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with 3-acetamidopyrrolidine. A yellow solid 83 was obtained (0.019 g, 65%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.99 (s, 3H), 2.22-2.29 (m, 1H), 2.33-2.40 (m, 1H), 3.49 (heptet, J=6.8 Hz, 1H), 3.73-3.81 (m, 2H), 3.82-3.87 (m, 1H), 3.96-4.04 (m, 1H), 4.62-4.67 (m, 1H), 6.78 (s, 1H), 6.90 (d, J=8.4 Hz, 1H), 6.94 (d, J=6.6 Hz, 1H), 7.26-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.85 (s, 1H), 8.03 (d, J=6.6 Hz, 1H); MS (APCI) m/z 500 (M+H)+. EXAMPLE 46 1-(4-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazin-1-yl)-ethanone 84 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with 1-acetylpiperazine. A yellow solid 84 was obtained (0.0033 g, 11%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 2.17 (s, 3H), 3.50 (heptet, J=6.8 Hz, 1H), 3.68-3.72 (m, 2H), 3.73-3.77 (m, 2H), 3.83-3.89 (m, 2H), 3.96-4.00 (m, 2H), 6.91 (d, J=8.4 Hz, 1H), 6.94 (s, 1H), 7.02 (d, J=5.5 Hz, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.86 (d, J=1.4 Hz, 1H), 8.28 (d, J=6.3 Hz, 1H); MS (APCI) m/z 500 (M+H)+. EXAMPLE 47 4′-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-carboxylic acid amide 85 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with isonipecotamide. A yellow solid 85 was obtained (0.0194 g, 66%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.89-1.99 (m, 2H), 2.07-2.13 (m, 2H), 2.58-2.65 (m, 1H), 3.41 (t, J=11.4 Hz, 2H), 3.50 (heptet, J=6.8 Hz, 1H), 4.28 (d, J=13.2 Hz, 2H), 5.65 (s, 1H), 6.06 (s, 1H), 6.90 (d, J=8.4 Hz, 1H), 6.95 (d, J=5.8 Hz, 1H), 6.99 (s, 1H), 7.25-7.29 (m, 1H), 7.44-7.52 (m, 4H), 7.85 (s, 1H), 8.18 (d, J=6.6 Hz, 1H). MS (APCI) m/z 500 (M+H)+. EXAMPLE 48 4′-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-carboxylic acid 86 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with isonipecotic acid. A yellow solid 86 was obtained (0.0112 g, 38%). 1H-NMR (CDCl3, 400 MHz) δ1.19 (d, J=6.8 Hz, 6H), 1.90-1.99 (m, 2H), 2.09-2.16 (m, 2H),2.70-2.77 (m, 1H), 3.43-3.53 (m, 3H), 4.11-4.17 (m, 2H), 6.90 (d, J=8.4 Hz, 1H), 6.95 (d, J=6.6 Hz, 1H), 6.99 (s, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.84 (d, J=1.1 Hz, 1H), 8.17 (d, J=6.6 Hz, 1H); MS (APCI) m/z 501 (M+H)+. EXAMPLE 49 4′-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyrindinyl-3-carboxylic acid 87 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with nipecotic acid. A yellow solid 87 was obtained (0.0229 g, 78%). 1H-NMR (CDCl3, 400 MHz) δ 0.19 (d, J=6.8 Hz, 6H), 1.65-1.74 (m, 1H), 1.89-1.96 (m, 1H), 2.05-2.10 (m, 2H), 2.83-2.89 (m, 1H), 3.49 (heptet, J=6.8 Hz, 1H), 3.56-3.63 (m, 1H), 3.78-3.88 (m, 2H), 4.13-4.18 (m, 1H), 6.91 (d, J=8.4 Hz, 1H), 6.95 (d, J=6.3 Hz, 1H), 7.07 (s, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.85 (s, 1H), 8.26 (d, J=6.6 Hz, 1H); MS (APCI) m/z 501 (M+H)+. EXAMPLE 50 2-(4′-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-yl-ethanol 88 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with 4-(1′-hydroxyethyl)piperidine. A yellow solid 88 was obtained (0.0245 g, 83%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.34-1.44 (m, 1H),1.57 (q, J=6.2 Hz, 2H), 1.84-1.93 (m, 1H), 1.97 (s, 1H), 2.00 (s, 1H), 3.25 (t, J=12.5 Hz, 2H), 3.50 (heptet, J=6.8 Hz, 1H), 3.74 (t, J=6.4 Hz, 2H), 4.32 (s, 1H), 4.34 (s, 1H), 6.88-6.95 (m, 2H), 6.96 (s, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.84 (s, 1H), 8.22 (d, J=6.6 Hz, 1H); MS (APCI) m/z 501 (M+H)+. EXAMPLE 51 4-Hydroxy-1-(4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-2-carboxylic acid 89 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with cis-4-hydroxy-D-proline. A yellow solid 89 was obtained (0.0187 g, 63%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 2.30-2.37 (m, 1H), 2.61 (d, J=13.5 Hz, 1H), 3.49 (heptet, J=6.8 Hz, 1H), 3.69-3.77 (m, 1H), 3.86-3.94 (m, 1H), 4.65 (s, 1H), 4.76-4.84 (m, 1H), 6.88 (d, J=8.4 Hz, 2H), 6.96 (d, J=6.3 Hz 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.83 (s, 1H), 7.99 (d, J=6.6 Hz, 1H); MS (APCI) m/z 503 (M+H)+. EXAMPLE 52 4-Hydroxy-1-(4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-2-carboxylic acid 90 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with trans-4-hydroxy-L-proline. A yellow solid 90 was obtained (0.0288 g, 97%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 2.44-2.50 (m, 1H), 2.65-2.67 (m, 1H), 3.49 (heptet, J=6.8 Hz, 1H), 3.68-3.74 (m, 1H). 3.87-3.93 (m, 1H), 4.65-4.70 (m, 1H), 4.92-4.98 (m, 1H), 6.82 (s, 1H), 6.89 (d, J=8.1 Hz, 1H), 6.94 (d, J=1.7 Hz, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.83 (s, 1H), 7.94-7.99 (br m, 1H). MS (APCI) m/z 503 (M+H)+. EXAMPLE 53 N-1-(4-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-yl)-N-methyl-acetamide 91 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with 3-(N-acetyl-N-methylamino)pyrrolidine. A yellow solid 91 was obtained (0.0265 g, 88%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 2.15 (s, 3H), 2.24-2.39 (m, 2H), 3.01 (s, 3H), 3.49 (heptet, J=6.8 Hz, 1H), 3.63-3.78 (m, 2H), 3.91-4.06 (m, 2H), 5.18-5.26 (m, 1H), 6.76 (s, 1H), 6.90 (d, J=8.4 Hz, 1H), 6.97 (d, J=5.9 Hz, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.86 (s, 1H), 8.18 (d, J=6.3 Hz, 1H); MS (APCI) m/z 514 (M+H)+. EXAMPLE 54 4-Hydroxy-4′-(4-(2-isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-3-carboxylic acid 92 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with (+/−)-cis-4-hydroxynipecotic acid. A yellow solid 92 was obtained (0.0087 g, 29%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 1.73-1.82 (m, 1H), 2.02-2.08 (m, 1H), 2.96-3.01 (m, 1H), 3.49 (heptet, J=6.8 Hz, 1H), 3.84 (d, J=6.6 Hz, 2H), 4.00 (t, J=12.6 Hz, 1H), 4.33 (d, J=12.4 Hz, 1H), 4.46 (s, 1H), 6.91 (d, J=8.4 Hz, 1H), 7.01 (d, J=6.2 Hz 1H), 7.08 (s, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.86 (s, 1H), 8.41 (d, J=6.6 Hz, 1H); MS (APCI) m/z 517 (M+H)+. EXAMPLE 55 (3-(4-(4-(4-(2-Isopropyl-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazin-1-yl)-propyl)-dimethyl-amine 93 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting 3-hydroxypyrrolidine with 1-(3-dimethylaminopropyl)piperazine. A yellow solid 93 was obtained (0.027 g, 85%). 1H-NMR (CDCl3, 400 MHz) δ 1.19 (d, J=6.8 Hz, 6H), 2.43-2.50(m, 6H), 2.86 (s, 6H), 3.22-3.30 (m, 4H), 3.36-3.40 (m, 2H), 3.51 (heptet, J=6.8 Hz, 1H), 4.08-4.12 (m, 2H), 6.83-6.94 (m, 2H), 7.01 (d, J=5.5 Hz, 1H), 7.25-7.29 (m, 1H), 7.46-7.54 (m, 4H), 7.86 (s, 1H), 8.23 (d, J=5.6 Hz, 1H); MS (APCI) m/z 543 (M+H)+. Example 56 1-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-ol 94 was synthesized according to the following procedure. 56A. First, 4-(4-(2-methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridine 1-oxide 95 was prepared as follows. The title compound was prepared according to the procedures of Example 38C, substituting 2-isopropylthiophenol with 2-methoxythiophenol. A white solid 95 was obtained (1.02 g, 77%). 1H-NMR (DMSO, 400 MHz) δ 3.79 (s, 3H), 7.04 (t, J=1.1 Hz, 7.6 Hz, 1H), 7.08 (d, J=8.0 Hz, 1H), 7.19 (dd, J=0.8 Hz, 8.4 Hz, 1H), 7.33 (dd, J=0.9 Hz, 8.4 Hz, 1H), 7.49 (dt, J=1.7 Hz, 7.6 Hz, 1H), 7.84 (dt, J=2.1 Hz, 7.2 Hz, 2H), 7.91 (dd, J=2.1 Hz, 8.4 Hz, 1H), 8.10 (d, J 2.1 Hz, 1H), 8.26 (dt, J=2.0 Hz, 7.2 Hz, 2H). MS (APCI) m/z 378 (M+H)+. 56B. Then 2-chloro-4-(4-(2-methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridine 96 was prepared as follows. The title compound was prepared according to the procedures of Example 38D, substituting compound 75 with compound 95 (0.900 g, 2.38 mmol). A yellow oil 96 was obtained (0.70 g, 74%). 1H-NMR (CDCl3, 400 MHz) δ 3.83 (s, 3H), 6.98-7.03 (m, 2H), 7.09 (d, J=8.2 Hz, 1H), 7.39(dd, J=1.7 Hz, 5.1 Hz, 1H), 7.41-7.46 (m, 2H), 7.49-7.53 (m, 2H), 7.87 (d, J=2.1 Hz, 1H), 8.43 (d, J=4.7 Hz, 1H); MS (APCI m/z 396) (M+H)+. 56C. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with (R)-3-hydroxypyrrolidine. A yellow solid 94 was obtained (0.0385 g, 87%). 1H-NMR (CDCl3, 400 MHz) δ 2.13-2.31 (m, 2H), 3.83 (s, 3H), 3.88-3.95 (m, 4H), 4.74 (m, 1H), 6.79 (s, 1H), 6.92 (d, J=6.6 Hz, 1H), 7.01-7.07 (m, 3H), 7.45-7.53 (m, 3H), 7.86 (s, 1H), 8.14 (d, J=7.0 Hz, 1H); MS (APCI) m/z 447 (M+H)+. EXAMPLE 57 1-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-2-yl)-methanol 97 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with (R)-2-(hydroxymethyl)pyrrolidine. A yellow solid 97 was obtained (0.0233 g, 51%). 1H-NMR (CDCl3, 400 MHz) δ 2.05-2.11 (m, 2H), 2.14-2.21 (m, 2H), 3.50 (q, J=9.1 Hz, 1H), 3.62-3.76 (m, 3H), 3.83 (s, 3H), 4.59-4.65 (m, 1H), 6.79 (s, 1H), 6.92 (d, J=6.3 Hz, 1H), 7.01-7.07 (m, 3H), 7.45-7.52 (m, 3H), 7.84 (s, 1H), 8.12 (d, J=6.6 Hz, 1H). MS (APCI) m/z 461 (M+H)+. EXAMPLE 58 4′-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-ol 98 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 4-hydroxypiperidine. A yellow solid 98 was obtained (0.0299 g, 66%). 1H-NMR (CDCl3, 400 MHz) δ 1.76-1.84 (m, 2H), 2.02-2.10 (m, 2H), 3.69-3.76 (m, 2H), 3.83 (s, 3H), 4.01-4.07 (m, 2H), 4.12-4.17 (m, 1H), 6.95 (d, J=6.6 Hz, 1H), 6.99 (s, 1H), 7.01-7.07 (m, 3H), 7.46-7.52 (m, 3H), 7.85 (s, 1H), 8.23 (d, J=6.6 Hz, 1H). MS (APCI) m/z 461 (M+H)+. EXAMPLE 59 4-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazine-1-carbaldehyde 99 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 1-formylpiperazine. A yellow solid 99 was obtained (0.0159 g, 34%). 1H-NMR (CDCl3, 400 MHz) δ 3.62-3.65 (m, 2H), 3.68-3.72 (m, 2H), 3.75-3.78 (m, 2H), 3.83 (s, 3H), 3.86-3.89 (m, 2H), 6.95 (s, 1H), 7.02 (m, 3H), 7.08 (d, J=8.4 Hz, 1H), 7.46-7.52 (m, 3H), 7.86 (d, J=1.5 Hz, 1H), 8.16 (s, 1H), 8.30 (d, J=6.2 Hz, 1H); MS (APCI) m/z 474 (M+H)+. EXAMPLE 60 1-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-2-carboxylic acid 100 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with (D)-proline. A yellow solid 100 was obtained (0.0366 g, 78%). 1H-NMR (CDCl3, 400 MHz) δ 2.14-2.38 (m, 3H), 2.48-2.55 (m, 1H), 3.58-3.66 (m, 1H), 3.80-3.89 (m, 1H), 3.83 (s, 3H), 4.96-5.05 (m, 1H), 6.82 (s, 1H), 6.96 (d, J=6.2 Hz, 1H), 7.01-7.07 (m, 3H), 7.46-7.52 (m, 3H), 7.84 (s, 1H), 8.04 (d, J=6.2 Hz, 1H). MS (APCI) m/z 475 (M+H)+. EXAMPLE 61 (4′-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-yl)-methanol 101 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 4-piperidinemethanol. A yellow solid 101 was obtained (0.0299 g, 64%). 1H-NMR (CDCl3, 400 MHz) δ 1.41-1.50 (m, 2H), 1.86-1.94 (m, 1H), 1.97-2.03 (m, 2H), 3.27 (t, J=13.6 Hz, 2H), 3.57 (d, J=5.8 Hz, 2H), 3.83 (s, 3H), 4.38 (d, J=13.5 Hz, 2H), 6.93 (d, J=6.6 Hz, 1H), 6.97 (s, 1H), 7.01-7.07 (m, 3H), 7.46-7.52 (m, 3H), 7.84 (s, 1H), 8.24 (d, J=6.2 Hz, 1H); MS (APCI) m/z 475 (M+H)+. EXAMPLE 62 N-1-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-yl)-acetamide 102 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with (3R)-(+)-3-acetamidopyrrolidine. A yellow solid 102 was obtained (0.0391 g, 81%). 1H-NMR (CDCl3, 400 MHz) δ 2.00 (s, 3H), 2.23-2.29 (m, 1H), 2.33-2.40 (m, 1H), 3.78-3.88 (m, 3H), 3.83 (s, 3H), 4.00-4.07 (m, 1H), 4.62-4.67 (m, 1H), 6.78 (s, 1H), 6.95 (d, J=6.6 Hz, 1H), 7.01-7.07 (m, 3H), 7.20 (br s, 1H), 7.46-7.52 (m, 3H), 7.85 (s, 1H), 8.06 (d, J=6.6 Hz, 1H). MS (APCI) m/z 488 (M+H)+. Example 63 N-1-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-yl)-acetamide 103 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 3-acetamidopyrrolidine. A yellow solid 103 was obtained (0.0306 g, 64%). 1H-NMR (CDCl3, 400 MHz) δ 2.01 (s, 3H), 2.25-2.31 (m, 1H), 2.33-2.41 (m, 1H), 3.80-3.90 (m, 3H), 3.83 (s, 3H), 4.01-4.10 (m, 1H), 4.63-4.69 (m, 1H), 6.79 (s, 1H), 6.96 (d, J=6.6 Hz, 1H), 7.01-7.07 (m, 3H), 7.12 (br s, 1H), 7.46-7.52 (m, 3H), 7.85 (s, 1H), 8.07 (d, J=6.6 Hz, 1H). MS (APCI) m/z 488 (M+H)+. EXAMPLE 64 1-(4-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazin-1-yl)-ethanone 104 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 1-acetylpiperazine. A yellow solid 104 was obtained (0.0197 g, 41%). 1H-NMR (CDCl3, 400 MHz) δ 2.17 (s, 3H), 3.68-3.72 (m, 2H), 3.73-3.78 (m, 2H), 3.82-3.89 (m, 2H), 3.83 (s, 3H), 3.94-3.99 (m, 2H), 6.95 (s, 1H), 7.00-7.05 (m, 3H), 7.07 (d, J=8.4 Hz, 1H), 7.45-7.52 (m, 3H), 7.86 (s, 1H), 8.29 (d, J=6.2 Hz, 1H). MS (APCI) m/z 488 (M+H)+. EXAMPLE 65 (4′-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-carboxylic acid amide 105 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with isonipecotamide. A yellow solid 105 was obtained (0.0272 g, 57%). 1H-NMR (CDCl3, 400 MHz) δ 1.90-1.99 (m, 2H), 2.08-2.14 (m, 2H), 2.59-2.66 (m, 1H), 3.39-3.47 (m, 2H), 3.83 (s, 3H), 4.29-4.34 (m, 2H), 5.57 (br s, 1H), 5.99 (br s, 1H), 6.97 (d, J=6.6 Hz, 1H), 6.99 (s, 1H), 7.00-7.05 (m, 2H), 7.06 (d, J=8.4 Hz, 1H), 7.46-7.52 (m, 3H), 7.85 (s, 1H), 8.20 (d, J=6.6 Hz, 1H); MS (APCI) m/z 488 (M+H)+. EXAMPLE 66 4′-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-carboxylic acid 106 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with isonipecotic acid. A yellow solid 106 was obtained (0.0225 g, 47%). 1H-NMR (CDCl3, 400 MHz) δ 1.90-1.99 (m, 2H), 2.09-2.16 (m, 2H), 2.68-2.77 (m, 1H), 3.43-3.50 (m, 2H), 3.83 (s, 3H), 4.14-4.20 (m, 2H), 6.95 (d, J=6.2 Hz, 1H), 6.99-7.05 (m, 3H), 7.06 (d, J=8.4 Hz, 1H), 7.45-7.52 (m, 3H), 7.84 (s, 1H), 8.20 (d, J=6.6 Hz, 1H); MS (APCI) m/z 489 (M+H)+. EXAMPLE 67 4′-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-3-carboxylic acid amide 107 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with nipecotic acid. A yellow solid 107 was obtained (0.0283 g, 59%). 1H-NMR (CDCl3, 400 MHz) δ 1.64-1.74 (m, 1H), 1.90-1.98 (m, 1H), 2.06-2.12 (m, 2H), 2.84-2.92 (m, 1H), 3.52-3.59 (m, 1H), 3.72-3.93 (m, 2H), 3.83 (s, 3H), 4.22-4.27 (m, 1H), 6.96 (d, J=5.9 Hz, 1H), 7.00-7.08 (m, 4H), 7.45-7.52 (m, 3H), 7.84 (s, 1H), 8.31 (d, J=6.5 Hz, 1H); MS (APCI) m/z 489 (M+H)+. EXAMPLE 68 2-(4′-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-yl)-ethanol 108 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 4-(2′-hydroxyethyl)piperidine. A yellow solid 108 was obtained (0.0308 g, 64%). 1H-NMR (CDCl3, 400 MHz) δ 1.34-1.43 (m, 2H), 1.58 (q, J=6.6 Hz, 2H), 1.84-1.93 (m, 1H), 1.96-2.02 (m, 2H), 3.21-3.29 (m, 2H), 3.74 (t, J=6.2 Hz, 2H), 3.83 (s, 3H), 4.33-4.39 (m, 2H), 6.91 (d, J=6.6 Hz, 1H), 6.96 (s, 1H), 7.00-7.07 (m, 3H), 7.45-7.52 (m, 3H), 7.84 (s, 1H), 8.24 (d, J=6.6 Hz, 1H); MS (APCI) m/z 489 (M+H)+. EXAMPLE 69 4-Hydroxy-1-(4-(4-(2-methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-2-carboxylic acid 109 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with cis-4-hydroxy-D-proline. A yellow solid 109 was obtained (0.030 g, 63%). MS (APCI) m/z 491 (M+H)+. EXAMPLE 70 4-Hydroxy-1-(4-(4-(2-methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-2-carboxylic acid 110 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with trans-4-hydroxy-L-proline. A yellow solid 110 was obtained (0.031 g, 65%). MS (APCI) m/z 491 (M+H)+. EXAMPLE 71 N-1-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-3-yl)-N-methyl-acetamide 111 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 3-(N-acetyl-N-methylamino)pyrrolidine. A yellow solid 111 was obtained (0.0211 g, 43%). 1H-NMR (CDCl3, 400 MHz) δ 2.15 (s, 3H), 2.22-2.30 (m, 1H), 2.31-2.39 (m, 1H), 3.00 (s, 3H), 3.62-3.69 (m, 1H), 3.71-3.78 (m, 1H), 3.83 (s, 3H), 3.90-3.96 (m, 1H), 3.98-4.06 (m, 1H), 5.20-5.28 (m, 1H), 6.76 (s, 1H), 6.97 (d, J=6.2 Hz, 1H), 7.00-7.04 (m, 2H), 7.06 (d, J=8.4 Hz, 1H), 7.45-7.52 (m, 3H), 7.86 (s, 1H), 8.22 (d, J=6.6 Hz, 1H); MS (APCI) m/z 502 (M+H)+. EXAMPLE 72 1-(4-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-(1,4)diazepan-1-yl)-ethanone 112 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with N-acetylhomopiperazine. A yellow solid 112 was obtained (0.0246 g, 50%). 1H-NMR (CDCl3, 400 MHz) δ 2.02-2.10 (m, 2H), 2.08 (s, 3H), 3.55 (t, J=5.9 Hz, 1H), 3.59 (t, J=5.5 Hz, 1H), 3.79 (t, J=6.2 Hz, 1H), 3.83 (s, 3H), 3.84-3.92 (m, 3H), 4.05 (t, J=5.3 Hz, 1H), 4.15 (t, J=5.5 Hz, 1H), 6.86 (s, ⅓H), 6.89 (s, ⅔H), 6.92-7.08 (m, 4H), 7.45-7.53 (m, 3H), 7.84 (s, ⅓H), 7.85 (s, ⅔H), 8.26-8.30 (m, 1H); MS (APCI) m/z 502 (M+H)+. EXAMPLE 73 (3-(4-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazine-1-yl)-propyl)-dimethyl-amine 113 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 1-(3-dimethylaminopropyl)piperazine. A yellow solid 113 was obtained (0.0414 g, 79%). 1H NMR (CDCl3, 400 MHz) δ 2.20-2.50 (br, 6H), 2.42-2.50 (m, 2H), 2.86 (s, 6H), 3.21-3.28 (m, 2H), 3.32-3.38 (br, 2H), 3.83 (s, 3H), 4.05-4.10 (br, 2H), 6.88 (s, 1H), 6.99-7.06 (m, 3H), 7.10 (d, J=8.2 Hz, 1H), 7.43-7.52 (m, 3H), 7.85 (s, 1H), 8.25 (d, J=5.5 Hz, 1H); MS (APCI) m/z 531 (M+H)+. EXAMPLE 74 1-(4-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-4-propyl-piperazine 114 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 1-propylpiperazine. A yellow solid 114 was obtained (0.033 g, 69%). 1H-NMR (CDCl3, 400 MHz) δ 1.03 (t, J=7.3 Hz, 3H), 1.83-1.92 (m, 2H), 2.65-3.10 (br, 8H), 2.98-3.04 (m, 2H), 3.83 (s, 3H), 6.89 (s, 1H), 6.99-7.06 (m, 3H), 7.09 (d, J=8.1 Hz, 1H), 7.43-7.52 (m, 3H), 7.85 (s, 1H), 8.26 (d, J=5.9 Hz, 1H); MS (APCI) m/z 488 (M+H)+. EXAMPLE 75 (4′-(4-(2-Methoxy-phenylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-3-yl)-methanol 115 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 96 (0.039 g, 0.0985 mmol) and 3-hydroxypyrrolidine with 3-hydroxymethyl piperidine. A yellow solid 115 was obtained (0.0279 g, 60%). 1H-NMR (CDCl3, 400 MHz) δ 1.32-1.42 (m, 1H), 1.63-1.74 (m, 1H), 1.86-1.95 (m, 2H), 2.04-2.14 (m, 1H), 3.18-3.25 (m, 1H), 3.33-3.39 (m, 1H), 3.47-3.52 (m, 1H), 3.71 (dd, J=4.0 Hz, 11.0 Hz, 1H), 3.83 (s, 3H), 4.02-4.07 (m, 1H), 4.48-4.53 (m, 1H), 6.93 (d, J=6.6 Hz, 1H), 7.00-7.08 (m, 4H), 7.45-7.52 (m, 3H), 7.84 (s, 1H), 8.35 (d, J=6.5 Hz, 1H); MS (APCI) m/z 475 (M+H)+. EXAMPLE 76 1-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-ol 116 was synthesized according to the following procedure. 76A. First, 4-(4-(2,3-dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridine 1-oxide 117 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38C, substituting 2-isopropylthiophenol with 3,4-ethylenedioxythiophenol (0.671 g, 3.99 mmol). A white solid 117 was obtained (1.39 g, 90%). 1H-NMR (DMSO, 400 MHz) δ 4.27-4.34 (m, 4H), 7.01-7.08 (m, 3H), 7.12 (d, J=8.4 Hz, 1H), 7.83 (d, J=7.3 Hz, 2H), 7.93 (dd, J=2.2 Hz, 8.5 Hz, 1H), 8.09 (d, J=2.2 Hz, 1H), 8.27 (d, J=7.4 Hz, 2H); MS (APCI) m/z 406 (M+H)+. 76B. Then, 2-chloro-(4-(4-(2,3-dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridine 118 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38D, substituting compound 75 with compound 117 (1.37 g, 3.38 mmol). A yellow oil 118 was obtained (0.87 g, 60%). 1H-NMR (DMSO, 400 MHz) δ 4.28-4.35 (m, 4H), 7.03-7.13 (m, 4H), 7.80 (dd, J=1.4 Hz, 5.2 Hz, 1H), 7.94 (d, J=1.2 Hz, 1H), 7.99 (dd, J=1.8 Hz, 8.5 Hz, 1H), 8.16 (d, J=1.8 Hz, 1H), 8.47 (d, J=5.2 Hz, 1H); MS (APCI) m/z 424 (M+H)+. 76C. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with (R)-3-hydroxypyrrolidine. A yellow solid 116 was obtained (0.0353 g, 75%). 1H-NMR (CDCl3, 400 MHz) δ 2.15-2.23 (m, 1H), 2.25-2.31 (m, 1H), 3.78-3.84 (m, 2H), 3.87-3.95 (m, 2H), 4.28-4.34 (m, 4H), 4.72-4.76 (m, 1H), 6.77 (s, 1H), 6.91 (dd, J=1.1 Hz, 6.6 Hz, 1H), 6.95 (d, J=8.1 Hz, 1H), 7.05 (dd, J=2.1 Hz, 8.1 Hz, 1H), 7.10 (d, J=2.2 Hz, 1H), 7.12 (d, J=8.4 Hz, 1H), 7.54 (dd, J=1.4 Hz, 8.5 Hz, 1H), 7.83 (d, J=1.1 Hz, 1H), 8.15 (d, J=6.6 Hz, 1H); MS (APCI) m/z 475 (M+H)+. EXAMPLE 77 4′-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-ol 119 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 4-hydroxypiperidine. A yellow solid 119 was obtained (0.031 g, 63%). 1H-NMR (CDCl3, 400 MHz) δ 1.75-1.84 (m, 2H), 2.02-2.10 (m, 2H), 3.67-3.74 (m, 2H), 4.00-4.07 (m, 2H), 4.10-4.16 (m, 1H), 4.28-4.34 (m, 4H), 4.72-4.76 (m, 1H), 6.93-6.97 (m, 3H), 7.05 (dd, J=1.8 Hz, 8.0 Hz, 1H), 7.10 (d, J=1.8 Hz, 1H), 7.12 (d, J=8.5 Hz, 1H), 7.52 (d, J=8.4 Hz, 1H), 7.82 (s, 1H), 8.25 (d, J=6.3 Hz, 1H); MS (APCI) m/z 489 (M+H)+. EXAMPLE 78 (1-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-2-yl)-methanol 120 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with (R)-2-(hydroxymethyl)pyrrolidine. A yellow solid 120 was obtained (0.027 g, 55%). 1H-NMR (CDCl3, 400 MHz) δ 2.06-2.11 (m, 2H), 2.16-0.21 (m, 2H), 3.46-3.53 (m, 1H), 3.63-3.76 (m, 3H), 4.28-4.34 (m, 4H), 4.61-4.66 (m, 1H), 6.78 (s, 1H), 6.92 (dd, J=1.4 Hz, 6.9 Hz, 1H), 6.95 (d, J=8.4 Hz, 1H), 7.05 (dd, J=2.2 Hz, 8.0 Hz, 1H), 7.10 (d, J=2.2 Hz, 1H), 7.12 (d, J=8.5 Hz, 1H), 7.52 (dd, J=1.9 Hz, 8.4 Hz, 1H), 7.82 (d, J=1.4 Hz, 1H), 8.13 (d, J=6.6 Hz, 1H); MS (APCI) m/z 489 (M+H)+. EXAMPLE 79 1-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidine-2-carboxylic acid 121 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with (D)-proline. A yellow solid 121 was obtained (0.035 g, 70%). MS (APCI) m/z 503 (M+H)+. EXAMPLE 80 (4′-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-yl)-methanol 122 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 4-piperidinemethanol. A yellow solid 122 was obtained (0.0284 g, 57%). 1H-NMR (CDCl3, 400 MHz) δ 1.41-1.51 (m, 2H), 1.86-1.95 (m, 1H), 1.97-2.04 (m, 2H), 3.23-3.31 (m, 2H), 3.57 (d, J=5.8 Hz, 2H), 4.28-4.34 (m, 4H), 4.36-4.41 (m, 2H), 6.92 (d, J=6.6 Hz, 1H), 6.93-6.97 (m, 2H), 7.05 (dd, J=1.8 Hz, 8.4 Hz, 1H), 7.09 (d, J=1.8 Hz, 1H), 7.12 (d, J=8.4 Hz, 1H), 7.52 (d, J=8.4 Hz, 1H), 7.82 (s, 1H), 8.25 (d, J=6.6 Hz, 1H); MS (APCI) m/z 503 (M+H)+. EXAMPLE 81 N-(1-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-yl)-acetamide 123 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with (3R)-(+)-3-acetamidopyrrolidine. A yellow solid 123 was obtained (0.0397 g, 78%). 1H-NMR (CDCl3, 400 MHz) δ 2.03 (s, 3H), 2.25-2.31 (m, 1H), 2.34-2.42 (m, 1H), 3.80-3.90 (m, 3H), 4.02-4.11 (m, 1H), 4.28-4.34 (m, 4H), 4.63-4.68 (m, 1H), 6.78 (s, 1H), 6.93-6.97 (m, 2H), 7.05 (dd, J=2.2 Hz, 8.4 Hz, 1H), 7.09-7.13 (m, 2H), 7.18 (brs, 1H), 7.53 (d, J=8.4 Hz, 1H), 7.83 (s, 1H), 8.07 (d, J=6.6 Hz, 1H); MS (APCI) m/z 516 (M+H)+. EXAMPLE 82 N-(1-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-yl)-acetamide 124 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 3-acetamidopyrrolidine. A yellow solid 124 was obtained (0.0369 g, 72%). 1H NMR (CDCl3, 400 MHz) δ 2.01 (s, 3H), 2.24-2.31 (m, 1H), 2.34-2.41 (m, 1H), 3.78-3.90 (m, 3H), 4.01-4.10 (m, 1H), 4.28-4.34 (m, 4H), 4.62-4.68 (m, 1H), 6.78 (s, 1H), 6.93-6.97 (m, 2H), 7.05 (dd, J=2.2 Hz, 8.4 Hz, 1H), 7.09-7.13 (m, 2H), 7.18 (br s, 1H), 7.53 (d, J=8.4 Hz, 1H), 7.83 (s, 1H), 8.07 (d, J=6.6 Hz, 1H); MS (APCI) m/z 516 (M+H)+. EXAMPLE 83 (1-(4-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazin-1-yl)-ethanone 125 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 1-acetylpiperazine. A yellow solid 125 was obtained (0.010 g, 19%). 1H-NMR (CDCl3, 400 MHz) δ 2.17 (s, 3H), 3.67-3.72 (m, 2H), 3.73-3.77 (m, 2H), 3.83-3.88 (m, 2H), 3.94-3.98 (m, 2H), 4.28-4.34 (m, 4H), 6.93 (s, 1H), 6.95 (d, J=8.4 Hz, 1H), 7.02 (d, J=5.8 Hz, 1H), 7.05 (dd, J=2.2 Hz, 8.4 Hz, 1H), 7.09 (d, J=2.2 Hz, 1H), 7.13 (d, J=8.4 Hz, 1H), 7.53 (d, J=8.1 Hz, 1H), 7.83 (s, 1H), 8.29 (d, J=6.2 Hz, 1H); MS (APCI) m/z 516 (M+H)+. EXAMPLE 84 4′-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-carboxylic acid amide 126 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with isonipecotamide. A yellow solid 126 was obtained (0.024 g, 47%). 1H-NMR (CDCl3, 400 MHz) δ 1.90-1.99 (m, 2H), 2.08-2.14 (m, 2H), 2.58-2.65 (m, 1H), 3.38-3.45 (m, 2H), 4.28-4.34 (m, 6H), 5.55 (br s, 1H), 5.97 (br s, 1H), 6.93-6.98 (m, 3H), 7.05 (dd, J=2.0 Hz, 8.2 Hz, 1H), 7.09 (d, J=1.8 Hz, 1H), 7.12 (d, J=8.4 Hz, 1H), 7.53 (d, J=8.4 Hz, 1H), 7.82 (s, 1H), 8.21 (d, J=6.6 Hz, 1H); MS (APCI) m/z 516 (M+H)+. EXAMPLE 85 4′-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-carboxylic acid 127 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with isonipecotic acid. A yellow solid 127 was obtained (0.014 g, 28%). 1H-NMR (CDCl3, 400 MHz) δ 1.89-1.98 (m, 2H), 2.08-2.15 (m, 2H), 2.68-2.76 (m, 1H), 3.40-3.48 (m, 2H), 4.13-4.20 (m, 2H), 4.28-4.34 (m, 4H), 6.91-6.98 (m, 3H), 7.04 (dd, J=1.9 Hz, 8.4 Hz, 1H), 7.09 (d, J=2.2 Hz, 1H), 7.12 (d, J=8.4 Hz, 1H), 7.52 (d, J=8.4 Hz, 1H), 7.82 (s, 1H), 8.20 (d, J=6.2 Hz, 1H); MS (APCI) m/z 517 (M+H)+. EXAMPLE 86 4′-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-3-carboxylic acid 128 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with nipecotic acid. A yellow solid 128 was obtained (0.034 g, 66%. 1H-NMR (CDCl3, 400 MHz) δ 1.64-1.74 (m, 1H), 1.92-1.99 (m, 1H), 2.06-2.13 (m, 2H), 2.88-2.95 (m, 1H), 3.50-3.57 (m, 1H), 3.68-3.74 (m, 2H), 3.90-3.96 (m, 1H), 4.28-4.36 (m, 4H), 6.94-6.98 (m, 2H), 7.03-7.07 (m, 2H), 7.09 (d, J=1.9 Hz, 1H), 7.12 (d, J=8.8 Hz, 1H), 7.52 (d, J=8.5 Hz, 1H), 7.82 (s, 1H), 8.32 (d, J=6.2 Hz, 1H); MS (APCI) m/z 517 (M+H)+. EXAMPLE 87 2-(4′-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridinyl-4-yl)-ethanol 129 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 4-(2′-hydroxyethyl)piperidine. A yellow solid 129 was obtained (0.037 g, 73%). 1H NMR (CDCl3, 400 MHz) δ 1.35-1.44 (m, 2H), 1.55-1.60 (m, 2H), 1.84-1.93 (m, 1H), 1.97-2.03 (m, 2H), 3.22-3.30 (m, 2H), 3.74 (t, J=6.2 Hz, 2H), 4.28-4.34 (m, 4H), 4.36-4.42 (m, 2H), 6.91 (d, J=6.6 Hz, 1H), 6.93-6.96 (m, 2H), 7.05 (dd, J=2.2 Hz, 8.4 Hz, 1H), 7.09 (d, J=2.2 Hz, 1H), 7.12 (d, J=8.8 Hz, 1H), 7.51 (d, J=8.8 Hz, 1H), 7.81 (s, 1H), 8.24 (d, J=6.6 Hz, 1H); MS (APCI) m/z 517 (M+H)+. EXAMPLE 88 1-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-4-hydroxy-pyrrolidine-2-carboxylic acid 130 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with cis-4-hydroxy-D-proline. A yellow solid 130 was obtained (0.038 g, 74%). 1H-NMR (CDCl3, 400 MHz) δ 2.34-2.42 (m, 1H), 2.64-2.68 (m, 2H), 3.73-3.82 (m, 1H), 3.94-4.00 (m, 1H), 4.28-4.34 (m, 4H), 4.68-4.74 (m, 1H), 6.92-7.12 (m, 6H), 7.52 (br, 1H), 7.80 (s, 1H), 8.04 (br, 1H); MS (APCI) m/z 519 (M+H)+. EXAMPLE 89 1-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-4-hydroxy-pyrrolidine-2-carboxylic acid 131 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-e 108 hydroxypyrrolidine with trans-4-hydroxy-L-proline. A yellow solid 131 was obtained (0.017 g, 33%). 1H-NMR(CDCl3,400 MHz)62.42-2.51 (m, 1H),3.66-3.72(m, 1H), 3.85-3.91 (m, 1H), 4.00-4.06 (m, 1H), 4.28-4.34 (m, 4H), 4.64-4.69 (m, 1H), 4.89-4.95 (m, 1H), 6.81 (s, 1H), 6.92-6.96 (m, 2H), 7.03 (dd, J=1.8 Hz, 8.4 Hz, 1H), 7.06-7.10 (m, 2H), 7.50 (d, J=8.4 Hz, 1H), 7.79 (s, 1H), 7.92-7.96 (m, 1H); MS (APCI) m/z 519 (M+H)+. EXAMPLE 90 N-1-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-pyrrolidin-3-yl)-N-methyl-acetamide 132 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 3-(N-acetyl-N-methylamino)pyrrolidine. A yellow solid 132 was obtained (0.022 g, 42%). 1H-NMR (CDCl3, 400 MHz) δ 2.15 (s, 3H), 2.20-2.29 (m, 1H), 2.32-2.40 (m, 1H), 3.00 (s, 3H), 3.62-3.70 (m, 1H), 3.71-3.78 (m, 1H), 3.90-3.96 (m, 1H), 3.98-4.06 (m, 1H), 4.28-4.34 (m, 4H), 5.21-5.29 (m, 1H), 6.74 (s, 1H), 6.93-6.97 (m, 2H), 7.05 (dd, J=2.2 Hz, 8.4 Hz, 1H), 7.10 (d, J=1.8 Hz, 1H), 7.12 (d, J=8.4 Hz, 1H), 7.53 (d, J=8.1 Hz, 1H), 7.83 (s, 1H), 8.23 (d, J=6.6 Hz, 1H); MS (APCI) m/z 530 (M+H)+. EXAMPLE 91 1-(4-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-tri fluoromethyl-phenyl)-pyridin-2-yl)-(1,4)diazepan-1-yl)-ethanone 133 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with N-acetylhomopiperazine. A yellow solid 133 was obtained (0.021 g, 40%). 1H-NMR (CDCl3, 400 MHz) δ 2.01-2.10 (m, 2H), 2.08 (s, 3H), 3.52-3.60 (m, 2H), 3.76-3.91 (m, 4H), 4.01-4.06 (m, 1H), 4.11-4.16 (m, 1H), 4.28-4.34 (m, 4H), 6.85 (s, ⅓H), 6.87 (s, ⅔H), 6.95 (d, J=8.4 Hz, 1H), 6.97 (d, J=6.6 Hz, 1H), 7.05 (dd, J=1.4 Hz, 8.4 Hz, 1H), 7.10 (d, J=2.2 Hz, 1H), 7.11-7.14 (m, 1H), 7.50-7.56 (m, 1H), 7.81 (s, ⅓H), 7.82 (s, ⅔H), 8.26-8.30 (m, 1H);MS (APCI) m/z 530 (M+H)+. EXAMPLE 92 (3-(4-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazin-1-yl)-propyl)-dimethyl-amine 134 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 1-(3-dimethylaminopropyl)piperazine. A yellow solid 134 was obtained (0.0401 g, 73%). MS (APCI) m/z 559 (M+H)+. EXAMPLE 93 1-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-4-propyl-piperazine 135 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 1-propylpiperazine. A yellow solid 135 was obtained (0.033 g, 64%). 1H-NMR (CDCl3, 400 MHz) δ 1.03 (t, J=7.3 Hz, 3H), 1.84-1.92 (m, 2H), 2.30-2.52 (br, 8H), 2.98-3.03 (m, 2H), 4.28-4.34 (m, 4H), 6.87 (s, 1H), 6.94 (d, J=8.1 Hz, 1H), 7.01 (d, J=5.8 Hz, 1H), 7.04 (dd, J=2.2 Hz, 8.4 Hz, 1H), 7.09 (d, J=2.2 Hz, 1H), 7.13 (d, J=8.4 Hz, 1H), 7.51 (d, J=8.3 Hz, 1H), 7.82 (s, 1H), 8.26 (d, J=5.9 Hz, 1H); MS (APCI) m/z 516 (M+H)+. EXAMPLE 94 1-Allyl-4-(4-(4-(2,3-dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazine 136 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 1-allylpiperazine. A yellow solid 136 was obtained (0.037 g, 73%). 1H-NMR (CDCl3, 400 MHz) δ 2.10-2.55 (br m, 6H), 3.24-3.45 (br m, 2H), 3.7 (d, J=7.0 Hz, 2H), 4.06-4.20 (br, 2H), 4.28-4.34 (m, 4H), 5.54 (d, J=7.2 Hz, 1H), 5.61 (d, J=10.2 Hz, 1H), 6.06 (m, 1H), 6.88 (s, 1H), 6.94 (d, J=8.4 Hz, 1H), 7.02-7.06 (m, 2H), 7.09 (d, J=1.9 Hz, 1H), 7.13 (d, J=8.1 Hz, 1H), 7.52 (d, J=8.1 Hz, 1H), 7.82 (s, 1H), 8.26 (d, J=5.9 Hz, 1H); MS (APCI) m/z 514 (M+H)+. EXAMPLE 95 2-(4-(4-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-pyridin-2-yl)-piperazin-1-yl)-ethanol 137 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 1-(2′-hydroxyethyl)piperazine. A yellow solid 137 was obtained (0.034 g, 67%). 1H-NMR (CDCl3, 400 MHz) δ 2.65-3.20 (br m, 4H), 3.24 (br m, 2H), 3.42-3.54 (m, 2H), 4.06 (br m, 2H), 4.05-4.18 (br m, 2H), 4.28-4.34 (m, 4H), 6.88 (s, 1H), 6.94 (d, J=8.4 Hz, 1H), 7.02-7.06 (m, 2H), 7.09 (d, J=2.2 Hz, 1H), 7.13 (d, J=8.0 Hz, 1H), 7.52 (d, J=7.7 Hz, 1H), 7.82 (s, 1H), 8.25 (d, J=5.9 Hz, 1H); MS (APCI) m/z 518 (M+H)+. EXAMPLE 96 (4′-(4-(2,3-Dihydro-benzo(1,4)dioxin-6-ylsulfanyl)-3-trifluoromethyl-phenyl)-3,4,5,6-tetrahydro-2H-(1,2′)bipyridnyl-3-yl)-methanol 138 was synthesized according to the following procedure. The title compound was prepared according to the procedures of Example 38E, substituting compound 76 with compound 118 (0.033 g, 0.0779 mmol) and 3-hydroxypyrrolidine with 3-hydryoxymethylpiperidine. A yellow solid 138 was obtained (0.030 g, 60%). 1H-NMR (CDCl3, 400 MHz) δ 1.33-1.42 (m, 1H), 1.65-1.74 (m, 1H), 1.87-1.94 (m, 2H), 2.06-2.14 (m, 1H), 3.20-3.26 (m, 1H), 3.33-3.40 (m, 1H), 3.47-3.53 (m, 1H), 3.70-3.75 (m, 1H), 4.02-4.08 (m, 1H), 4.28-4.34 (m, 4H), 4.50-4.56 (m, 1H), 6.92 (d, J=6.6 Hz, 1H), 6.95 (d, J=8.4 Hz, 1H), 7.01 (s, 1H), 7.05 (dd, J=2.2 Hz, 8.4 Hz, 1H), 7.09 (d, J=1.8 Hz, 1H), 7.12 (d, J=8.4 Hz, 1H), 7.52 (d, J=8.3 Hz, 1H), 7.83 (s, 1H), 8.33 (d, J=6.6 Hz, 1H); MS (APCI) m/z 503 (M+H)+. EXAMPLE 97 Compounds that antagonize the interaction between ICAM-1 and LFA-1 can be identified, and their activities quantitated, using both biochemical and cell-based adhesion assays. A primary biochemical assay, described below as assay 97A, was utilized to measure the ability of the present compounds to block the interaction between the integrin LFA-1 and its adhesion partner ICAM-1. 97A. ICAM-1/LFA-1 Biochemical Interaction Assay In the biochemical assay, 100 mL of anti-LFA-1 antibody (ICOS Corporation) at a concentration of 5 mg/ml in Dulbecco's phosphate-buffered saline (D-PBS) is used to coat wells of a 96-well microtiter plate overnight at 4° C. The wells are then washed twice with wash buffer (D-PBS w/o Ca++ or Mg++, 0.05% Tween 20) and blocked by addition of 200 mL of D-PBS, 5% fish skin gelatin. Recombinant LFA-1 (100 mL of 0.7 mg/ml, ICOS Corporation) in D-PBS is then added to each well. Incubation continues for 1 hour at room temperature and the wells are washed twice with wash buffer. Serial dilutions of compounds being assayed as ICAM-1/LFA-1 antagonists, prepared as 10 mM stock solutions in dimethyl sulfoxide (DMSO), are diluted in D-PBS, 2 mM MgCl2, 1% fish skin gelatin and 50 mL of each dilution added to duplicate wells. This is followed by addition of 50 mL of 0.8 mg/ml biotinylated recombinant ICAM-1/Ig (ICOS Corporation) to the wells and the plates are incubated at room temperature for 1 hour. The wells are then washed twice with wash buffer and 100 mL of Europium-labeled Streptavidin (Wallac Oy) diluted 1:100 in Delfia assay buffer (Wallac Oy) are added to the wells. Incubation proceeds for 1 hour at room temperature. The wells are washed eight times with wash buffer and 100 μL of enhancement solution (Wallac Oy, cat. No. 1244-105) are added to each well. Incubation proceeds for 5 minutes with constant mixing. Time-resolved fluorimetry measurements are made using the Victor 1420 Multilabel Counter (Wallac Oy) and the percent inhibition of each candidate compound is calculated using the following equation: % inhibition = 100 × { 1 - average OD w / compound minus background average OD w / o compound minus background } where “background” refers to wells that are not coated with anti-LFA-1 antibody. The compounds inhibit the binding of ICAM-1 to LFA-1 with an IC50 less than 20 micromolar. Biologically relevant activity of the compounds in this invention was confirmed using a cell-based adhesion assay, (described below as assay 97B) which measured the ability of the present compounds to block the adherence of JY-8 cells (a human EBV-transformed B cell line expressing LFA-1 on its surface) to immobilized ICAM-1. 97B. ICAM-1/JY-8 Cell Adhesion Assay For measurement of inhibitory activity in the cell-based adhesion assay, 96-well microtiter plates are coated with 70 μL of recombinant ICAM-1 g (ICOS Corporation) at a concentration of 5 μg/mL in D-PBS w/o Ca++ or Mg++ overnight at 4° C. The wells are then washed twice with D-PBS and blocked by addition of 200 μL of D-PBS, 5% fish skin gelatin by incubation for 1 hour at room temperature. Fluorescent tagged JY-8 cells (a human EBV-transformed B cell line expressing LFA-1 on its surface; 50 μL at 2×106 cells/ml in RPMI 1640 (standard cell culture medium)/1% fetal bovine serum) are added to the wells. For fluorescent labeling of JY-8 cells, 5×106 cells washed once in RPMI 1640 are resuspended in 1 mL of RPMI 1640 containing 2 μM Calceiun AM (MolecularProbes), are incubated at 37° C. for 30 minutes and washed once with RPMI-1640/1% fetal bovine serum. Dilutions of compounds to be assayed for ICAM-1/LFA-1 antagonistic activity are prepared in RPMI-1640/1% fetal bovine serum from 10 mM stock solutions in DMSO and 50 μL are added to duplicate wells. Microtiter plates are incubated for 45 minutes at room temperature and the wells are washed gently once with RPMI-1640/1% fetal bovine serum. Fluorescent intensity is measured in a fluorescent plate reader with an excitation wavelength at 485 nM and an emission wavelength at 530 nM. The percent inhibition of a candidate compound at a given concentration is calculated using the following equation: % inhibition = 100 × { 1 - average OD w / compound average OD w / o compound } and these concentration/inhibition data are used to generate dose response curves, from which IC50 values are derived. The ability of the compounds of this invention to treat arthritis can be demonstrated in a murine collagen-induced arthritis model according to the method of Kakimoto, et al., Cell Immunol 142: 326-337, 1992, in a rat collagen-induced arthritis model according to the method of Knoerzer, et al., Toxicol Pathol 25:13-19, 1997, in a rat adjuvant arthritis model according to the method of Halloran, et al., Arthitis Rheum 39: 810-819, 1996, in a rat streptococcal cell wall-induced arthritis model according to the method of Schimmer, et al., J Immunol 160: 1466-1477, 1998, or in a SCID-mouse human rheumatoid arthritis model according to the method of Oppenheimer-Marks et al., J Clin Invest 101: 1261-1272, 1998. The ability of the compounds of this invention to treat Lyme arthritis can be demonstrated according to the method of Gross et al., Science 281, 703-706, 1998. The ability of compounds of this invention to treat asthma can be demonstrated in a murine allergic asthma model according to the method of Wegner et al., Science 247:456-459, 1990, or in a murine non-allergic asthma model according to the method of Bloemen et al., Am J Respir Crit Care Med 153:521-529, 1996. The ability of compounds of this invention to treat inflammatory lung injury can be demonstrated in a murine oxygen-induced lung injury model according to the method of Wegner et al., Lung 170:267-279, 1992, in a murine immune complex-induced lung injury model according to the method of Mulligan et al., J Immunol 154:1350-1363, 1995, or in a murine acid-induced lung injury model according to the method of Nagase, et al., Am J Respir Crit Care Med 154:504-510, 1996. The ability of compounds of this invention to treat inflammatory bowel disease can be demonstrated in a rabbit chemical-induced colitis model according to the method of Bennet et al., J Pharmacol Exp Ther 280:988-1000, 1997. The ability of compounds of this invention to treat autoimmune diabetes can be demonstrated in an NOD mouse model according to the method of Hasagawa et al., Int Immunol 6:831-838, 1994, or in a murine streptozotocin-induced diabetes model according to the method of Herrold et al., Cell Immunol 157:489-500, 1994. The ability of compounds of this invention to treat inflammatory liver injury can be demonstrated in a murine liver injury model according to the method of Tanaka et al., J Immunol 151:5088-5095, 1993. The ability of compounds of this invention to treat inflammatory glomerular injury can be demonstrated in a rat nephrotoxic serum nephritis model according to the method of Kawasaki, et al., J Immunol 150:1074-1083, 1993. The ability of compounds of this invention to treat radiation-induced enteritis can be demonstrated in a rat abdominal irradiation model according to the method of Panes et al., Gastroenterology 108:1761-1769, 1995. The ability of compounds of this invention to treat radiation pneumonitis can be demonstrated in a murine pulmonary irradiation model according to the method of Hallahan et al., Proc Natl Acad Sci USA 94:6432-6437, 1997. The ability of compounds of this invention to treat reperfusion injury can be demonstrated in the isolated rat heart according to the method of Tamiya et al., Immunopharmacology 29(1): 53-63, 1995, or in the anesthetized dog according to the model of Hartman et al., Cardiovasc Res 30(1): 47-54, 1995. The ability of compounds of this invention to treat pulmonary reperfusion injury can be demonstrated in a rat lung allograft reperfusion injury model according to the method of DeMeester et al., Transplantation 62(10): 1477-1485, 1996, or in a rabbit pulmonary edema model according to the method of Horgan et al., Am J Physiol 261(5): H1578-H1584, 1991. The ability of compounds of this invention to treat stroke can be demonstrated in a rabbit cerebral embolism stroke model according the method of Bowes et al., Exp Neurol 119(2): 215-219, 1993, in a rat middle cerebral artery ischemia-reperfusion model according to the method of Chopp et al., Stroke 25(4): 869-875, 1994, or in a rabbit reversible spinal cord ischemia model according to the method of Clark et al., Neurosurg 75(4): 623-627, 1991. The ability of compounds of this invention to treat peripheral artery occlusion can be demonstrated in a rat skeletal muscle ischemia/reperfusion model according to the method of Gute et al., Mol Cell Biochem 179: 169-187, 1998. The ability of compounds of this invention to treat graft rejection can be demonstrated in a murine cardiac allograft rejection model according to the method of Isobe et al., Science 255: 1125-1127, 1992, in a murine thyroid gland kidney capsule model according to the method of Talento et al., Transplantation 55: 418-422, 1993, in a cynomolgus monkey renal allograft model according to the method of Cosimi et al., J Immunol 144: 4604-4612, 1990, in a rat nerve allograft model according to the method of Nakao et al., Muscle Nerve 18: 93-102, 1995, in a murine skin allograft model according to the method of Gorczynski and Wojcik, J Immunol 152: 2011-2019, 1994, in a murine corneal allograft model according to the method of He et al., Opthalmol Vis Sci 35: 3218-3225, 1994, or in a xenogeneic pancreatic islet cell transplantation model according to the method of Zeng et al., Transplantation 58:681-689, 1994. The ability of compounds of this invention to treat graft-vs.-host disease (GVHD) can be demonstrated in a murine lethal GVHD model according to the method of Harning et al., Transplantation 52:842-845, 1991. The ability of compounds of this invention to treat cancers can be demonstrated in a human lymphoma metastasis model (in mice) according to the method of Aoudjit et al., J Immunol 161:2333-2338, 1998. All references cited are hereby incorporated by reference. The present invention is illustrated by way of the foregoing description and examples. The foregoing description is intended as a non-limiting illustration, since many variations will become apparent to those skilled in the art in view thereof. It is intended that all such variations within the scope and spirit of the appended claims be embraced thereby. Changes can be made in the composition, operation and arrangement of the method of the present invention described herein without departing from the concept and scope of the invention as defined in the following claims: | <SOH> BACKGROUND OF THE INVENTION <EOH>Inflammation results from a cascade of events that includes vasodilation accompanied by increased vascular permeability and exudation of fluid and plasma proteins. This disruption of vascular integrity precedes or coincides with an infiltration of inflammatory cells. Inflammatory mediators generated at the site of the initial lesion serve to recruit inflammatory cells to the site of the injury. These mediators (chemokines such as IL-8, MCP-1, MIP-1, and RANTES, complement fragments and lipid mediators) have chemotactic activity for leukocytes and attract the inflammatory cells to the inflamed lesion. These chemotactic mediators which cause circulating leukocytes to localize at the site of inflammation require the cells to cross the vascular endothelium at a precise location. This leukocyte recruitment is accomplished by a process called cell adhesion. Cell adhesion occurs through a coordinately regulated series of steps that allow the leukocytes to first adhere to a specific region of the vascular endothelium and then cross the endothelial barrier to migrate to the inflamed tissue (Springer, T. A., 1994, “Traffic Signals for Lymphocyte Recirculation and Leukocyte Emigration: The Multistep Paradigm”, Cell, 76: 301-314; Lawrence, M. B., and Springer, T. A., 1991, “Leukocytes' Roll on a Selectin at Physiologic Flow Rates: Distinction from and Prerequisite for Adhesion Through Integrins”, Cell 65: 859-873; von Adrian, U., Chambers, J. D., McEnvoy, L. M., Bargatze, R. F., Arfos, K. E, and Butcher, E. C., 1991, “Two-Step Model of Leukocyte-Endothelial Cell Interactions in Inflammation”, Proc. Nat'l. Acad. Sci. USA, 88: 7538-7542; and Ley, K., Gaehtgens, P., Fennie, C., Singer, M. S., Lasky, L. H. and Rosen, S. D.,1991, “Lectin-Like Cell Adhesion Molecule 1 Mediates Rolling in Mesenteric Venules in vivo”, Blood, 77: 2553-2555). These steps are mediated by families of adhesion molecules such as integrins, Ig supergene family members, and selectins which are expressed on the surface of the circulating leukocytes and on the vascular endothelial cells. The first step consists of leukocytes rolling along the vascular endothelial cell lining in the region of inflammation. The rolling step is mediated by an interaction between a leukocyte surface oligosaccharide, such as Sialylated Lewis-X antigen (SLe x ), and a selectin molecule expressed on the surface of the endothelial cell in the region of inflammation. The selectin molecule is not normally expressed on the surface of endothelial cells but rather is induced by the action of inflammatory mediators such as TNF-α and interleukin-1. Rolling decreases the velocity of the circulating leukocyte in the region of inflammation and allows the cells to more firmly adhere to the endothelial cell. The firm adhesion is accomplished by the interaction of integrin molecules that are present on the surface of the rolling leukocytes and their counter-receptors (the Ig superfamily molecules) on the surface of the endothelial cell. The Ig superfamily molecules or CAMs (Cell Adhesion Molecules) are either not expressed or are expressed at low levels on normal vascular endothelial cells. The CAM's, like the selecting, are induced by the action of inflammatory mediators like TNF-alpha and IL-1. The final event in the adhesion process is the extravasation of leukocytes through the endothelial cell barrier and their migration along a chemotactic gradient to the site of inflammation. This transmigration is mediated by the conversion of the leukocyte integrin from a low avidity state to a high avidity state. The adhesion process relies on the induced expression of selectins and CAM's on the surface of vascular endothelial cells to mediate the rolling and firm adhesion of leukocytes to the vascular endothelium. The interaction of the intercellular adhesion molecule ICAM-1 (cd54) on endothelial cells with the integrin LFA-1 on leukocytes plays an important role in endothelial-leukocyte contact. Leukocytes bearing high-affinity LFA-1 adhere to endothelial cells through interaction with ICAM-1, initiating the process of extravasation from the vasculature into the surrounding tissues. Thus, an agent which blocks the ICAM-1/LFA-1 interaction suppresses these early steps in the inflammatory response. Consistent with this background, ICAM-1 knockout mice have numerous abnormalities in their inflammatory responses. The present invention discloses compounds which bind to the interaction-domain (1-domain) of LFA-1, thus interrupting endothelial cell-leukocyte adhesion by blocking the interaction of LFA-1 with ICAM-1, ICAM-3, and other adhesion molecules. These compounds are useful for the treatment or prophylaxis of diseases in which leukocyte trafficking plays a role, notably acute and chronic inflammatory diseases, autoimmune diseases, tumor metastasis, allograft rejection, and reperfusion injury. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is directed to compounds of the structure wherein R 1 , R 2 , R 3 , R 4 and R 5 are each independently selected from the group consisting of hydrogen, halogen, alkyl, haloalkyl, alkoxy, cyano, nitro, cycloalkyl and carboxaldehyde; with the proviso that at least one of R 1 or R 3 is wherein D, B, Y and Z at each occurrence are independently selected from the group consisting of —CR 6 ═, —CR 7 R 8 —, —C(O)—, —O—, —SO 2 —, —S—, —N═, and —NR 9 —; n is an integer of zero to three; R 6 , R 7 , R 8 and R 9 , at each occurrence, are each independently selected from the group consisting of hydrogen, alkyl, carboxy, hydroxyalkyl, alkylaminocarbonyl alkyl, dialkylaminocarbonylalkyl and carboxyalkyl; and R 10 and R 11 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, alkoxyalkyl, alkoxycarbonylalkyl, carboxyalkyl, hydroxyalkyl, heterocyclyl, heterocyclylalkyl and heterocyclylamino; wherein R 10 and R 11 may be joined to form a three to seven membered heterocyclyl ring, said ring being optionally substituted with one or more substituents R 13 , wherein R 13 , at each occurrence is independently selected from the group consisting of alkyl, alkylene, alkoxy, alkoxyalkyl, cycloalkyl, aryl, heterocyclyl, heterocyclylalkyl, heterocyclylcarbonyl, heterocyclylalkylaminocarbonyl, hydroxy, hydroxyalkyl, hydroxyalkoxyalkyl, carboxy, carboxyalkyl, carboxycarbonyl, carboxaldehyde, alkoxycarbonyl, arylalkoxycarbonyl, aminoalkyl, aminoalkanoyl, aminocarbonyl, carboxamido, alkoxycarbonylalkyl, carboxamidoalkyl, cyano, tetrazolyl, alkanoyl, hydroxyalkanoyl, alkanoyloxy, alkanoylamino, alkanoyloxyalkyl, alkanoylaminoalkyl, sulfonate, alkylsulfonyl, alkylsulfonylaminocarbonyl, arylsulfonylaminocarbonyl and heterocyclylsulfonylaminocarbonyl; wherein A is an aryl or heterocyclyl group, said aryl or heterocyclyl group having at least one substituent R 12 , wherein R 12 is selected from the group consisting of hydrogen, halogen, alkyl, aryl, haloalkyl, hydroxy, alkoxy, alkoxyalkyl, alkoxycarbonyl, alkoxyalkoxy, hydroxyalkyl, aminoalkyl, aminocarbonyl, alkyl(alkoxycarbonylalkyl) aminoalkyl, heterocyclyl, heterocyclylalkyl, carboxaldehyde, carboxaldehyde hydrazone, carboxamide, alkoxycarbonylalkyl, carboxy, carboxyalkyl, carboxyalkyl, carboxyalkoxy, carboxythioalkoxy, carboxycycloalkoxy, thioalkoxy, carboxyalkylamino, trans-cinnamyl, hydroxyalkylaminocarbonyl, cyano, amino, heterocyclylalkylamino, and heterocyclylalkylaminocarbonyl; and wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 and R 12 are unsubstituted or substituted with at least one electron donating or electron withdrawing group; or a pharmaceutically-acceptable salt, optical isomer or prodrug thereof. Presently preferred compounds of Formula I have R 3 as Formula II (shown above), with substituents defined as above, R 1 and R 2 each independently as hydrogen, halogen, haloalkyl or nitro; and R 4 and R 5 each independently as hydrogen or alkyl. The present invention is also directed to compounds of the structure wherein R 1 , R 2 , R 4 and R 5 are each independently selected from the group consisting of hydrogen, halogen, alkyl, haloalkyl, alkoxy, cyano, nitro, cycloalkyl and carboxaldehyde; D, B, Y and Z are as defined above; R 12 , at each occurrence, is independently selected from the group consisting of hydrogen, halogen, alkyl, haloalkyl, alkoxy, carboxyalkoxy, carboxyalkyl and heterocyclyl; and, p is an integer of zero to five; wherein R 1 , R 2 , R 4 , R 5 , R 10 , R 11 and R 12 are unsubstituted or substituted with at least one electron donating group or electron withdrawing group. Presently most preferred compounds of Formula III have p as one; R 4 and R 5 as hydrogen; R 12 as halogen, alkyl, alkoxy, carboxyalkoxy, carboxyalkyl or heterocyclyl; and R 10 and R 11 joined to form a three to seven membered heterocyclyl ring; said ring being piperidine, piperazine, morpholine, pyrrolidine or azetidine. Presently most preferred compounds are of the structure wherein D and B are each independently selected from the group consisting of —N═ and —CR 6 ═; R 1 and R 2 are each independently selected from the group consisting of hydrogen, halogen and haloalkyl; R 10 and R 11 are as defined above for Formula I; R 12 , at each occurrence, is independently selected from the group consisting of hydrogen, halogen, alkyl, haloalkyl, alkoxy, carboxyalkoxy, carboxyalkyl and heterocyclyl; and, p is an integer of zero to five; wherein R 1 , R 2 , R 10 , R 11 and R 12 are unsubstituted or substituted with at least one electron donating group or electron withdrawing group. For presently most preferred compounds of Formula IV, p may be one; R 12 may be halogen, alkyl, alkoxy, carboxyalkoxy, carboxyalkyl or heterocyclyl; and R 10 and R 11 may be joined to form a three to seven membered heterocyclyl ring; said ring being piperidine, piperazine, morpholine, pyrrolidine or azetidine. The compounds represented by structural Formula I, above, may be prepared by synthetic processes or by metabolic processes. Processes for the preparation of the compounds of the present invention by metabolic processes include those occurring in the human or animal body (in vivo) or by processes occurring in vitro. The present invention is also directed to a method of treatment or prophylaxis in which the inhibition of inflammation or suppression of immune response is desired, comprising administering an effective amount of a compound having Formula I. In yet another embodiment of the invention are disclosed pharmaceutical compositions containing compounds of Formula I. detailed-description description="Detailed Description" end="lead"? | 20040209 | 20061031 | 20050120 | 74200.0 | 0 | COPPINS, JANET L | ARYL PHENYLHETEROCYCLYL SULFIDE DERIVATIVES AND THEIR USE AS CELL ADHESION-INHIBITING ANTI-INFLAMMATORY AND IMMUNE-SUPRESSIVE AGENTS | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,773,389 | ACCEPTED | Laundry basket with hip hugging feature | A laundry basket has a bottom panel with a perimeter. A contiguous side wall extends generally upward from the perimeter of the bottom panel and terminates at an upper end. A basket interior is defined above the bottom panel and bounded by the side wall. A curved wall section of the side wall is curved concavely inward toward the basket interior. The bottom panel and the contiguous side wall, including the curved wall section, are formed of a primary material. A cushion pad is positioned generally at the upper end of the curved wall section and is formed from a secondary material that is softer than the primary material of the curved wall portion. | 1. A laundry basket comprising: a bottom panel having a perimeter; a contiguous side wall extending generally upward from the perimeter of the bottom panel and terminating at an upper end; a basket interior defined above the bottom panel and bounded by the side wall; a curved wall section of the side wall that is curved concavely inward toward the basket interior, the bottom panel and contiguous side wall including the curved wall section being formed of a primary material; and a cushion pad positioned generally at the upper end of the curved wall section, the cushion pad being formed from a secondary material that is softer than the primary material of the curved wall portion. 2. A laundry basket according to claim 1, further comprising: a rim provided along and extending outward from the upper end of the side wall, the cushion pad being positioned on and covering outwardly facing surfaces of a rim section that positionally coincide with the curved wall section. 3. A laundry basket according to claim 1, wherein the secondary material of the cushion pad has an exposed surface that has a higher coefficient of friction that the primary material of the basket. 4. A laundry basket according to claim 1, further comprising: at least one handle provided near the upper end of the side wall and positioned opposite the curved wall section. 5. A laundry basket according to claim 4, further comprising: a handle grip formed on the handle from a material that is softer than the primary material of the basket. 6. A laundry basket according to claim 2, further comprising: at least one handle provided on the rim of the side wall and positioned on the rim opposite the curved wall section; and a handle grip formed covering a section of the rim that corresponds with the position of the handle, the handle grip being formed from a material that is softer than that primary material of the basket. 7. A laundry basket according to claim 1, wherein the secondary material is thermoplastic elastomer. 8. A laundry basket comprising: a bottom panel having a perimeter; a contiguous side wall extending generally upward from the perimeter of the bottom panel, the side wall terminating at an upper end; a rim formed extending around and generally outwardly from the upper end of the side wall; a basket interior defined above the bottom panel and bounded by the side wall; a curved wall section of the side wall that is curved concavely inward toward the basket interior, the bottom panel and contiguous side wall including the curved wall section being formed of a primary material; a recess formed in the rim and positioned to coincide with the curved wall section; at least one handle provided on the side wall near the upper end and positioned opposite the curved wall section; and a cushion pad positioned in the recess, the cushion pad being formed from a secondary material that is softer than the primary material of the curved wall portion. 9. A laundry basket according to claim 8, wherein the side wall has a pair of opposed elongate side sections and a pair of opposed shorter end sections, wherein the curved wall section is one of the pair of side sections, and wherein the at least one handle is provided on the other of the pair of side sections. 10. A laundry basket according to claim 9, further comprising: a second inwardly curved wall section formed on one of the pair of end sections. 11. A laundry basket according to claim 10, further comprising: at least a second handle provided on the other of the pair of end sections. | RELATED APPLICATION DATA This patent is related to, claims priority from, and incorporates herein by reference co-pending U.S. Provisional Patent Application Ser. No. 60/445,278, which was filed on Feb. 5, 2003. BACKGROUND OF THE INVENTION 1. Field of the Disclosure The present disclosure is generally directed to laundry baskets, and more particularly to a laundry basket with a hip hugging feature. 2. Description of Related Art Laundry baskets are well known as aids for doing laundry, and particularly for carrying and transporting either dirty laundry items or already laundered items. A typical laundry basket is somewhat rectangular and has a contiguous side wall with two elongate walls and two shorter end walls. The basket also has a bottom panel coupled to the contiguous side wall, an open top, and a basket interior. Laundry baskets are also known to have shapes that are not rectangular, such as round or cylindrical laundry baskets. A relatively recent improvement in laundry baskets is to provide the basket in a kidney-shape, wherein one of the elongate sides is slightly concavely curved inward toward the basket interior and the opposite elongate side is outwardly or convexly curved away from the basket interior. U.S. Design Pat. No. D416,116 (issued to Sofy) discloses an example of a laundry basket that is a hybrid of a non-rectangular basket shape and one that has an inwardly curved side. The inwardly curved side of such a laundry basket is typically used as an ergonomic tool to assist a user in carrying the basket, especially when it is loaded with laundry items. A user can rest the inwardly curved side of the basket against their hip, so that the basket rests on their pelvic bone or against their skin above the pelvic bone. The user can use their arm to grasp the opposite side of the basket to support and hold the basket with only one hand. Thus, the user has one hand free to open and close doors or to perform other needed tasks while carrying a load of laundry. One problem with this type of laundry basket is that the inwardly curved edge of the basket can dig into a user's hip which can cause discomfort. Another problem is that the basket can slip from their hip relatively easily while it is being carried. Laundry baskets are typically made from a relatively smooth, shiny, and, thus, relatively slippery plastic material. Further, a typical laundry basket has an outwardly rolled rim at the top end of the contiguous side wall. The exposed edge of the rolled rim typically is the portion of the basket that bears against the user's side, digging into the flesh of the user causing the discomfort. BRIEF DESCRIPTION OF THE DRAWINGS Objects, features, and advantages of the present invention will become apparent upon reading the following description in conjunction with the drawing figures, in which: FIG. 1 shows a perspective view of one example of a laundry basket with a hip hugging feature constructed in accordance with the teachings of the present invention. FIG. 2 shows a top view of the laundry basket shown in FIG. 1. FIG. 3 shows a cross section of a handle of the laundry basket shown in FIGS. 1 and 2 and taken along line III-III in FIG. 1. FIG. 4 shows a cross section of the hip hugging feature illustrated in FIGS. 1 and 2 and taken along line IV-IV of FIG. 1. FIG. 5 shows a top view of an alternative embodiment of a laundry basket with multiple hip hugging features constructed in accordance with the teachings of the present invention. DETAILED DESCRIPTION OF THE DISCLOSURE The present invention is generally directed to improving upon laundry baskets with a hip hugging feature. The problems discussed above that relate to hip hugger type laundry baskets are addressed herein by incorporating a cushion or padded element to the laundry basket at each location on the laundry basket that is curved for contact with a user's hip. Referring now to the drawings, FIGS. 1 and 2 illustrate a laundry basket 10 constructed in accordance with the teachings of the present invention. The basket 10 includes a bottom panel 12 having a perimeter 14 and a contiguous side wall 16 that extends generally upward from the bottom panel perimeter. The bottom panel 12 and contiguous side wall 16 generally define a basket interior above the bottom panel and bounded by the side wall. As is known to those having ordinary skill in the art, the bottom panel 12 can include ribs, ridges, and other suitable formations in the panel to provide structural rigidity, resting pads for the basket, and/or other features desired for a particular laundry basket. Additionally, it is well known in the art to form the bottom panel 12 and side wall 16 as an integral one-piece plastic molded structure. Any number of materials are suitable for forming such a laundry basket. These include, but are certainly not limited to, polyethylene, polypropylene, polystyrene, or the like. The present invention is not intended to be limited to a particular material for the laundry basket 10. Instead, hardness and surface characteristics of the basket material in comparison to other parts of the laundry basket come into play as discussed below. The material of the bottom panel and side wall are hereinafter referred to as the primary basket material. Also as is well known to those having ordinary skill in the art, the side wall 16 can include a plurality of perforations or openings 20 passing through the wall to the interior 18. The plural perforations 20 can be patterned, shaped, arranged, and configured as desired. Typically, the perforations permit air to reach laundry items held in the basket interior. The perforations 20 also aid in reducing the weight and the amount of material necessary to form the laundry basket 10. However, the particular shape and placement of such perforations can be designed to provide a particular aesthetic appearance while retaining its necessary degree of structural rigidity. As illustrated in FIGS. 1 and 2, a lower end of the side wall 16 transitions into the perimeter of the bottom panel and the side wall terminates at an upper end 22. As illustrated in FIGS. 3 and 4, it is common for a laundry basket such as the basket 10 to include an inverted rim 24 extending upward and outward from the upper end 22 of the side wall 16. The rim 24 adds strength and rigidity to the overall structure of the basket 10 and also provides a smooth, blunt surface at the wall upper end 22. In this example, the rim 24 is an arch with a concavely curved recessed underside. Higher end laundry baskets can include a plurality of ribs traversing across the underside of the rim structure for additional support and rigidity, though such ribs are not shown herein. In this disclosed example, the arched rim 24 includes a curved rim wall 26 that extends upward from the upper end 22 of the side wall 16 and gradually curves outwardly from the side wall and back down in the general direction of the bottom panel. A terminal edge of the rim wall 26 can include an enlarged thickness, integral plastic bead 30, which can be rounded to reduce the sharpness of the exposed edge. The bead 30 can also add limited structural rigidity to the rim 24 and, hence to the basket 10. As depicted in FIGS. 1 and 3, the laundry basket 10 can also include one or more handles 32 provided at strategic locations on the side wall 16 near the upper end 22. The structure of the handles 32 can vary considerably and yet fall within the spirit and scope of the invention. In the disclosed example, the handles 32 are formed by providing a grip opening 34 through the side wall 16 near the upper end 22 but below the rim 24 at each desired location for a handle. Thus, a user can firmly grip the basket by wrapping their hands around the rim 24 at one or two handle locations and by passing their fingers and/or thumb through the grip opening 34. As will be evident to those having ordinary skill in the art, handles need not be provided on a given laundry basket 10. A user could simply grip the rim to carry such a basket. Alternatively, handles can be provided simply by adding surface contours, depressions, and/or the like to the rim 24 at desired handle locations. Such contours can be provided to identify handle locations to the user and to provide a comfortable grip on the rim 24 without actually providing grip openings 34 through the side wall of the basket. As an option, one or more of the handles 32 can be formed herein having a padded handle cover. This option is described in greater detail below. Returning again to FIGS. 1 and 2, the side wall 16 in the disclosed example has a plurality of interconnected side wall sections. A pair of elongate side walls sections 40 and 42 are positioned opposite one another across the basket interior 18 and a pair of shorter end wall sections 44 and 46 are positioned opposite one another across the basket interior. In this disclosed example, the elongate side walls sections 40 and 42 are longer than the end wall sections 44 and 46, thus, giving the laundry basket 10 an overall generally rectangular shape. However, the side wall sections are slightly curved as are the end wall sections providing a more or less kidney-shaped basket. Specifically, the side wall section 40 is concavely curved inward into the basket interior 18 to provide a hip hugging feature. Though not necessary, the side wall section 42 is convexly curved outward away from the basket interior. In this example, the side wall sections 40 and 42 generally follow the same contour, although this is also not necessary. The contour of the curvature or non-curvature of the side walls can be different between the two sections 40 and 42, if desired. In this example, the end wall sections 44 and 46 each are convexly curved slightly outward away from the basket interior 18 giving the basket 10 rounded ends. The corners of the basket 10 where side wall sections 40 and 42 transition to end wall sections 44 and 46 are rounded in this example as well. As will be evident to those having ordinary skill in the art, the contiguous side wall 16 could take on any number of different configurations and constructions and need not have a kidney shape or a rectangular shape. However, in accordance with the teachings of the present invention, the side wall 16 must have at least one side wall section or region that is inwardly curved like the side wall 40 to provide a hip hugging feature. As shown in FIGS. 1 and 4, a portion of the rim wall 26 of the rim 24 that corresponds the position of the inwardly curved side wall section 40 includes what is described herein as a cushion pad 50. In the disclosed example, as best illustrated in FIG. 4, the cushion pad 50 is formed from a secondary material that is different from the primary material used to manufacture bottom panel 12, side wall 16, and the rim 24 of the laundry basket 10. The secondary material of the cushion pad 50 is softer than the primary material and, thus, provides a cushioned area on the curved hip contacting portion of the basket 10. In one example, the cushion pad 50 is formed from a thermoplastic elastomer material (TPE) or other such relatively soft, resilient, and durable material. In another example, the cushion pad 50 can also be formed from a durable open cell foam with or without a skin layer, or can be formed from a closed cell foam material if desired. Preferably, the secondary material of the cushion pad 50 has a lower Shore hardness, and thus is a less hard material as compared to the primary plastic material of the basket. The Shore hardness can be measured using any suitable Durometer apparatus and under either a Shore A or Shore D scale, for example. The thickness of the cushion pad 50 can also vary as desired for a particular basket application. As shown in FIG. 4, however, the cushion pad 50 preferably covers a good portion of the rim wall 26 in the hip hugging region of the wall section 40. In this example, the cushion pad 50 has a lower edge 52 that extends downward to cover at least most of the terminal end, which is the bead 30 in this example, of the rim 24. Also in this example, the pad 50 has an upper edge 53 that extends upward along the rim wall 26 far enough to at least completely cover the outer facing side of the rim wall 26. In this manner, the cushion pad 50 will be the only material part that contacts a users hip during use. For the wall section 40 in this example, only the material of the cushion pad 50 is exposed and can contact the user's hip. In one example, the cushion pad 50 is also formed from a material that has a friction enhancing surface 54. The friction enhancing surface preferably provides a higher coefficient of friction than the primary material of the laundry basket adjacent the cushion pad 50. The friction enhancing surface can help to inhibit the laundry basket from sliding down the hip of a user while carrying a loaded basket 10. The friction enhancing surface 54 can be formed on the pad in any suitable manner. For example, the surface can be inherently formed as a part of the cushion pad 50 by utilizing a elastomer, rubber, or other suitable material that has an inherently tacky surface. In one alternative, the surface of the cushion pad 50 can be treated during its formation to provide the friction enhancing characteristic. In another alternative, a surface treatment can be added to or performed on the surface of the pad 50 to increase its tackiness. As a further alternative, an additional layer (not shown) can be added to define the surface 54 of the cushion pad in order to render the surface more tacky. It is intended only that the friction enhancing surface 54, if present, increase the coefficient of friction of the cushion pad 50, as compared to the remaining exposed primary material of the laundry basket 10. A number of methods and constructions can be employed to provide or create the cushion pad 50 on the inwardly curved elongate side wall section 40 of the laundry basket 10 disclosed herein. As represented in FIG. 4, a recess or pocket 60 can effectively be formed, depending upon the manufacturing process utilized, in a hip hugging region 62 of the rim 24 on the basket 10. In one example, the basket 10 including the recess 60 can be formed from the primary material in a basket mold by a suitable process, such as by injection molding. A separate process can be undertaken to form the cushion pad 50 from the secondary material to have a shape such that it can fit in and seat within the recess 60. The pad 50 can subsequently be adhered within the recess 60. In such a process, the cushion pad 50 can be adhered using an adhesive, heat welding, molecular bonding, or other like means. In another alternative example, the cushion pad 50 can be formed from the secondary material during an initial molding, extrusion, or other suitable process. The preformed pad 50 can then be placed as an insert into and held within a larger mold cavity configured to mold the laundry basket 10. The laundry basket primary material can then be shot into the mold cavity to subsequently form the basket 10 around the pad 50 insert. The primary material of the laundry basket 10 would flow around the pad, form the shape of the recess 60, and encompass the pad material other than the surfaces borne against the basket mold cavity. A recess 60 would be effectively formed in this example as well. The resulting basket and pad structure would be essentially the same as that shown in FIG. 4 and described in the first example. The molding processes, bulk materials, and material temperatures can be manipulated such that, during an insert or in-molding process, the secondary material of the cushion pad 50 and the primary material of the basket 10 become bonded with one another. Alternatively, an active adhesive layer can be added to the appropriate surfaces of the cushion pad 50 prior to being inserted into the basket mold cavity. The basket can then be molded around the pad 50. The adhesive layer will activate to bond the cushion pad 50 to the primary material of the basket 10. In another alternative, though not shown, a basket can be formed having a uniform rim surface on the rim 24 with no recess 60. An add-on cushion pad or cushion layer can simply be secured, adhered, molded onto, or otherwise attached to the uniform surface of the rim 24. The effect would be the same in that a cushion pad would still be positioned in the hip hugging region 62 of the concavely curved side wall section 40. In an alternative embodiment illustrated in FIG. 5, a second hip hugging region can be added to another section of the basket side wall. A basket 100 is illustrated in FIG. 5 and has a first elongate inwardly curved side wall section 102 providing a first hip hugging rim region 104. The basket 100 also has an inwardly curved end wall section 106 defining a second hip hugging rim region 108. A user can hold the basket 100 with either the elongate side wall section 102 or the shorter end wall section 106 born against their hip as desired. As illustrated in FIG. 3, each handle can also have a grip pad 110 that is constructed and formed in the same manner as the cushion pad 50. The grip pad 110 can, if desired, also interact with a recess 112 effectively formed in the rim 24 of the basket 10. Thus, each handle 32 can provide a comfortable grip that eliminates any sharp edges of the handle or rim at a handle location. The grip pad 110 can be formed from the same secondary material as the cushion pad, or some other material that is softer than the primary material of the basket. Although certain laundry basket examples have been described herein in accordance with the teachings of the present disclosure, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all embodiments of the teachings of the disclosure that fairly fall within the scope of permissible equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Disclosure The present disclosure is generally directed to laundry baskets, and more particularly to a laundry basket with a hip hugging feature. 2. Description of Related Art Laundry baskets are well known as aids for doing laundry, and particularly for carrying and transporting either dirty laundry items or already laundered items. A typical laundry basket is somewhat rectangular and has a contiguous side wall with two elongate walls and two shorter end walls. The basket also has a bottom panel coupled to the contiguous side wall, an open top, and a basket interior. Laundry baskets are also known to have shapes that are not rectangular, such as round or cylindrical laundry baskets. A relatively recent improvement in laundry baskets is to provide the basket in a kidney-shape, wherein one of the elongate sides is slightly concavely curved inward toward the basket interior and the opposite elongate side is outwardly or convexly curved away from the basket interior. U.S. Design Pat. No. D416,116 (issued to Sofy) discloses an example of a laundry basket that is a hybrid of a non-rectangular basket shape and one that has an inwardly curved side. The inwardly curved side of such a laundry basket is typically used as an ergonomic tool to assist a user in carrying the basket, especially when it is loaded with laundry items. A user can rest the inwardly curved side of the basket against their hip, so that the basket rests on their pelvic bone or against their skin above the pelvic bone. The user can use their arm to grasp the opposite side of the basket to support and hold the basket with only one hand. Thus, the user has one hand free to open and close doors or to perform other needed tasks while carrying a load of laundry. One problem with this type of laundry basket is that the inwardly curved edge of the basket can dig into a user's hip which can cause discomfort. Another problem is that the basket can slip from their hip relatively easily while it is being carried. Laundry baskets are typically made from a relatively smooth, shiny, and, thus, relatively slippery plastic material. Further, a typical laundry basket has an outwardly rolled rim at the top end of the contiguous side wall. The exposed edge of the rolled rim typically is the portion of the basket that bears against the user's side, digging into the flesh of the user causing the discomfort. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>Objects, features, and advantages of the present invention will become apparent upon reading the following description in conjunction with the drawing figures, in which: FIG. 1 shows a perspective view of one example of a laundry basket with a hip hugging feature constructed in accordance with the teachings of the present invention. FIG. 2 shows a top view of the laundry basket shown in FIG. 1 . FIG. 3 shows a cross section of a handle of the laundry basket shown in FIGS. 1 and 2 and taken along line III-III in FIG. 1 . FIG. 4 shows a cross section of the hip hugging feature illustrated in FIGS. 1 and 2 and taken along line IV-IV of FIG. 1 . FIG. 5 shows a top view of an alternative embodiment of a laundry basket with multiple hip hugging features constructed in accordance with the teachings of the present invention. detailed-description description="Detailed Description" end="lead"? | 20040205 | 20100316 | 20080605 | 67971.0 | B65D9002 | 0 | BRADEN, SHAWN M | LAUNDRY BASKET WITH HIP HUGGING FEATURE | UNDISCOUNTED | 0 | ACCEPTED | B65D | 2,004 |
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10,773,479 | ACCEPTED | Operating system utilizing a selectively concealed multi-function wall station transmitter with an auto-close function for a motorized barrier operator | An operating system which utilizes a multi-functional wall station for a motorized barrier includes an operator for controlling movement of a barrier between various positions. The operator may receive signals from a wireless or wired wall station transmitter, a wireless keyless entry device and/or a portable remote transmitter device. The multi-function wall station provides for selective concealment of certain switches or buttons which are not commonly used in the day-to-day operation of a wall station. For example, the up/down switch may be actuated by a hinged cover which conceals other selected operational buttons and wherein those operational buttons are only accessed upon opening of the hinged cover. The wall station also provides a periodic lighting element so as to easily direct the user to push the hinge cover to initiate up/down movement of the barrier. The multi-function wall station also provides for an operational selection wherein the door may be closed in a normal manner; by an auto-close feature, wherein the door closes after a predetermined period of time; or a RF block mode, wherein the station prevents transmission of any remote radio frequency signals to the operating system. The auto-close feature may only be enabled upon actuation of a keyless entry device so as to allow the user to re-enter the garage in the unfortunate circumstance of being locked out of the garage. | 1. An operator system for moving a barrier comprising: a motor for moving the barrier between opened and closed positions; an operator for controlling operation of said motor; and a wall station having a wall station transmitter for sending operational signals to said operator, said wall station having an open/close switch for actuating said motor to move the barrier in the appropriate direction; said wall station also having a manual-close/auto-close selector switch, wherein if an auto-close mode is selected said operator automatically closes the barrier if left open for a predetermined period of time. 2. The operator system according to claim 1, wherein said wall station comprises: a panel carrying said open/close switch and said selector switch; and a cover positionable with respect to said panel, wherein said cover in a first position permits access to said switches and in a second position conceals said switches but allows actuation of said open/close switch. 3. The operator system according to claim 2, wherein said cover comprises: an exterior surface; an interior surface opposite said exterior surface; a nub extending from said interior surface and in juxtaposition with said open/close switch when said cover is in said second position; and said cover movable in said second position to allow actuation of said open/close switch with said nub. 4. The operator system according to claim 3, wherein said exterior surface has a distinguishable tactile surface opposite said nub. 5. The operator system according to claim 1, further comprising: a keyless entry transmitter capable of sending operational signals to said operator and moving the barrier in the appropriate direction, wherein said operator will only enable said auto-close mode if said keyless entry transmitter is associated therewith. 6. The operator system according to claim 1, further comprising: at least one external transmitter capable of sending operational signals to said operator and moving the barrier in the appropriate direction, wherein said operator will only enable said auto-close mode if said at least one external transmitter initiates an open command. 7. The operator system according to claim 6, wherein said at least one external transmitter is selected from a group consisting of a keyless entry transmitter and a portable remote transmitter. 8. The operator system according to claim 1, wherein said predetermined period of time is adjustable and wherein said wall station transmitter also functions as a transceiver. 9. An operator system for moving a barrier comprising: a motor for moving the barrier between opened and closed positions; an operator for controlling operation of said motor; and a wall station having a wall station transmitter for sending operational signals to said operator, said wall station having an open/close switch for actuating said motor to move the barrier in the appropriate direction; and said wall station also having an auto-close/blocking selector switch which, if enabled in a blocking mode, precludes said operator from receiving operational signals from any source other than said wall station. 10. The operator system according to claim 9, wherein said blocking selector switch comprises additional modes of manual-close and auto-close, wherein if said auto-close mode is selected said operator automatically closes the barrier if left open for a predetermined period of time. 11. The operator system according to claim 10, wherein said wall station comprises: a panel carrying said open/close switch and said selector switch; and a cover positionable with respect to said panel, wherein said cover in a first position permits access to said switch and in a second position conceals said switches but allows actuation of said open/close switch. 12. An operator system for moving a barrier comprising: a motor for moving the barrier between opened and closed positions; an operator for controlling operation of said motor; a wireless wall station having a wall station transmitter for sending operational signals to said operator, said wireless wall station having an open/close switch for actuating said motor to move the barrier in the appropriate direction; and a light source illuminating said wireless wall station from within. 13. The operator source according to claim 12, wherein said wireless wall station comprises: a panel carrying said open/close switch and said light source. 14. The operator system according to claim 13, wherein said wireless wall station further comprises: a cover positionable with respect to said panel, wherein said cover in a first position permits access to said switch and in a second position conceals said switches but allows actuation of said open/close switch 15. The operator system according to claim 14, wherein said cover has light transmitting properties to allow light transmission of said light source. 16. The operator system according to claim 15, wherein said cover comprises: an exterior surface; an interior surface opposite said exterior surface; a nub extending from said interior surface and in juxtaposition with said open/close switch when said cover is in said second position; and said cover movable in said second position to allow actuation of said open/close switch with said nub. 17. The operator system according to claim 16, wherein said exterior surface has a distinguishable tactile surface opposite said nub. 18. The operator system according to claim 16, wherein said interior surface further comprises a diffuser extending from said interior surface and in juxtaposition with said light source when said cover is in said second position. 19. The operator system according to claim 14, wherein said panel comprises: a recessed panel and an exposed panel; said recessed panel covered by said cover when in said second position, said exposed panel carrying other operational switches. 20. The operator according to claim 14, wherein said cover is hinged to said panel at an edge thereof. 21. The operator system according to claim 20, further comprising: a light controlled by said operator; and a light switch carried by said wall station at said edge. 22. The operator system according to claim 21, wherein said light switch is actuable by applying a force in one of two directions. 23. An operator system for moving a barrier comprising: a motor for moving the barrier between opened and closed positions; an operator for controlling operation of said motor; and a wall station having a wall station transmitter for sending operational signals to said operator, said wall station having an open/close switch for actuating said motor to move the barrier in the appropriate direction, said wall station also having a blocking selector switch which, if enabled, precludes said operator from receiving operational signals from any source other than said wall station transmitter, said wall station comprising: a panel carrying said open/close switch and said selector switch; and a cover positionable with respect to said panel, wherein said cover in a first position permits access to said switch and in a second position conceals said switches but allows actuation of said open/close switch. 24. The operator system according to claim 23, further comprising: a light controlled by said operator; and a light switch carried by said wall station, wherein said light switch is actuable by applying a force in one of two directions. 25. The operator system according to claim 24, wherein said cover comprises: an exterior surface; an interior surface opposite said exterior surface; a nub extending from said interior surface and in juxtaposition with said open/close switch when said cover is in said second position; and said cover movable in said second position to allow actuation of said open/close switch with said nub. 26. The operator system according to claim 25, wherein said exterior surface has a distinguishable tactile surface opposite said nub. 27. An operator system for moving a barrier comprising: a motor for moving the barrier between opened and closed positions; an operator for controlling operation of said motor; and a wall station having a wall station transmitter for sending operational signals to said operator, said wall station having an open/close switch for actuating said motor to move the barrier in the appropriate direction; said operator capable of receiving operational signals from said wall station transmitter and any programmed transmitter; said wall station also having a manual-close/auto-close/block switch, wherein if a manual-close mode is selected said operator only closes the door upon receipt of a door close signal from one of said wall station and said programmed transmitter; wherein if an auto-close mode is selected said operator automatically closes the barrier if left open for a predetermined period of time; and wherein if a block mode is selected, said operator is precluded from receiving operational signals from any source other than said wall station transmitter. 28. The operator system according to claim 27, wherein said wall station comprises: a panel carrying said open/close switch and said selector switch; and a cover positionable with respect to said panel, wherein said cover in a first position permits access to said switches and in a second position conceals said switches but allows actuation of said open/close switch. 29. The operator system according to claim 28, wherein said cover comprises: an exterior surface; an interior surface opposite said exterior surface; a nub extending from said interior surface and in juxtaposition with said open/close switch when said cover is in said second position; and said cover movable in said second position to allow actuation of said open/close switch with said nub. 30. The operator system according to claim 29, wherein said exterior surface has a distinguishable tactile surface opposite said nub. 31. The operator system according to claim 27, wherein said operator generates a warning signal immediately prior to said operator automatically closing the barrier. 32. The operator system according to claim 31, wherein said operator incrementally closes the barrier after completion of the said warning signal, unless one of said operational signals is received during said warning signal. 33. The operator system according to claim 32, wherein said operator generates a second warning signal after said incremental closing and prior to said operator automatically closing the barrier. 34. The operator system according to claim 33, wherein said operator closes the barrier after completion of said second warning signal, unless one of said operational signals is received during said warning signal. 35. The operator system according to claim 27, wherein said operator generates a warning signal immediately prior to said operator incrementally closing the barrier, whereupon said operator repeats generation of said warning signal and incremental closing until the barrier is completely closed. 36. The operator system according to claim 35, wherein the barrier is returned to an open position if one of said warning signals is received during said warning signal. 37. A wall station for transmitting signals to an operator that moves a motorized barrier, comprising: a panel; an open/close switch carried by said panel, wherein actuation of said open/close switch causes the operator to move the barrier in an appropriate direction; at least one other function switch carried by said panel, wherein actuation of said other function switch causes the operator to perform the corresponding function; and a cover positionable with respect to said panel, wherein said cover in a first position permits access to said switches and in a second position conceals said switches but allows actuation of said open/close switch. 38. The wall station according to claim 37, wherein said cover comprises: an exterior surface; an interior surface opposite said exterior surface; a nub extending from said interior surface and in juxtaposition with said open/close switch when said cover is in said second position; and said cover movable in said second position to allow actuation of said open/close switch with said nub. 39. The wall station according to claim 38, wherein said exterior surface has a distinguishable tactile surface opposite said nub. 40. The wall station according to claim 37, further comprising: a light source emanating from said panel. 41. The wall station according to claim 40, wherein said cover has light transmitting properties to allow light transmission of said light source. 42. The wall station according to claim 41, wherein said cover comprises: an exterior surface; an interior surface opposite said exterior surface; a nub extending from said interior surface and in juxtaposition with said open/close switch when said cover is in said second position; and said cover movable in said second position to allow actuation of said open/close switch with said nub. 43. The wall station according to claim 42, wherein said interior surface further comprises a diffuser extending from said interior surface and in juxtaposition with said light source when said cover is in said second position. 44. A wall station transmitter for sending operational signals to an operator that controls movement of a barrier comprising: a housing having a battery compartment, said housing having a ledge at one end of said battery compartment and a ridge at an opposite end of said battery compartment, said ledge having a groove adjacent a nub, and said ridge having a notch; and a battery cover that detachably encloses said battery compartment, said cover having a catch at one end and a latch at an opposite end, said latch detachably received in said notch and said catch detachably received by said groove. 45. The wall station transmitter according to claim 44, wherein said catch comprises: a U-shaped member having a pivot point; a lever arm extending from said pivot point; a retainer extending from said lever; and a finger extending from said lever arm, said finger and said retainer forming a slot therebetween. 46. The wall station transmitter according to claim 45, wherein said retainer is receivable in said groove and said nub is receivable in said slot. 47. The wall station transmitter according to claim 46, wherein application of a force on said finger moves said lever arm with respect to said pivot point and disengages said retainer from said groove and said nub from said slot. 48. The wall station transmitter according to claim 47, wherein said housing has a hinge cavity for receiving said catch, said retainer having a ramp surface that is deflected by said nub upon insertion of said catch into said hinge cavity. | TECHNICAL FIELD Generally, the present invention relates to a garage door operator system for use on a closure member moveable relative to a fixed member. More particularly, the present invention relates to a wall station transmitter for controlling the operation of a movable barrier, such as a gate or door, between a closed position and an open position. More specifically, the present invention relates to a wired or wireless wall station control for a door or gate operator, wherein the wall station has a plurality of buttons or touch pad keys which may be selectively concealed, and wherein actuation of a button implements a corresponding function of the operating system. One function in particular provides an auto-close function which automatically closes the movable barrier after a pre-determined period of time. BACKGROUND ART As is well known, garage doors or gates enclose an area to allow selective ingress and egress to and from the area. Garage doors initially were moveable by hand. But due to their weight and the inconvenience of opening and closing the door, motors are now connected to the door. Control of such a motor may be provided by a hard-wired push button which, when actuated, relays a signal to an operator controller that starts the motor and moves the door in one direction until a limit position is reached. After the door has stopped and the button is pressed again, the motor moves the door in an opposite direction. Garage door operators are now provided with safety features which stop and reverse the door travel when an obstruction is encountered. Other safety devices, such as photocells and sensors, detect whenever there is an obstruction within the path of the door and send a signal to the operator to take corrective action. Remote control devices are now also provided to facilitate the opening and closing of the door without having to get out of the car. The prior art also discloses various other features which enhance the convenience of opening and closing a garage door as follows. U.S. Pat. No. 4,119,896, to Estes, III et al., discloses a sequencing control circuit provided for a door operator motor which is connected to open and close a garage door as controlled by signals from manual switches and load switches. The sequencing control circuit includes time means with a first time period in the order of six to eight seconds. This permits a person to hold a push button switch closed for about six to eight seconds so that a slab door may be opened against a snow drift which otherwise would have so much torque requirement on the motor that an overload switch would stop the motor. Enabling means is provided to enable the motor during this time period yet to disable the constant signal from the push button for periods longer than this time period so that the door operator motor then is responsive to signals from the load switches. The sequencing control circuit also includes a latch circuit having an output in a feedback loop to maintain the latch circuit latched upon a momentary input control signal. This allows time for the motor to accelerate the load to a normal running condition and to open any closed limit switch or closed torque switch during this acceleration period. U.S. Pat. No. 4,247,806, to Mercier, discloses a garage door opener including a radio receiver and a push button, each operable to initiate a pulse for effecting a switching device which, in turn, energizes a latching relay. Operation of the latching relay completes an energizing circuit to the appropriate winding of a reversible motor which moves the door toward an open or closed position. A sensing circuit is operable for effecting the reversal of the latching relay to change the direction of motor operation in the event the door engages an object in its path. A foot switch may also be provided for positively sensing an obstacle and reversing the drive motor. A transmitter may be provided with an impulse circuit to limit the duration of the system actuating signal regardless of how long the transmitter push button is depressed. U.S. Pat. No. 4,607,312, to Barreto-Mercado, discloses a system that eliminates the conventional automobile door and trunk locks and provides power operated locks remotely controlled by a VHF radio transmission which is coded with two code signals, one of which energizes the door locks to locking condition and the other of which causes door or trunk unlocking, the trunk unlocking being activated only if a trunk transfer push button switch has been operated. The unlocking code may also activate the electric power to the engine starter motor, hood and manual switches of the power door operating motor. The system provided by the invention for unlocking or locking the doors of an automobile and for unlocking the trunk and hood of the same automobile as well as the engine electric power, all from outside the automobile permits the removal of the conventional mechanical door locking mechanism, including both the external key-operated apparatus and that controlled by an internal push button, and the removal of the conventional key-operated mechanical trunk lock, and the substitution of an externally operable radio controlled lock and unlock system for the door and an unlock system for the trunk and hood. U.S. Pat. No. 4,808,995, to Clark et al., discloses a radio remote-controlled door operator for use, among other uses, as a residential garage door operator. The transmitter contains two buttons, one to produce normal door operation and the other to set the operator into a “secure” mode, wherein it will be non-responsive to further valid operating codes until reset. In addition, a second deeper level of security may be established by means of a vacation switch which disconnects the operator from the AC power supply. The operator system comprises a microprocessor which is programmed to perform various accessory functions even through the accessories may not be present. Various microprocessor inputs are tied to a false “safe” level so that even though the accessory programs are run, no outputs result and no interference with normal door operation is produced. U.S. Pat. No. 5,086,385, to Launey et al., discloses a system for and a method of providing an expandable home automation controller which supports multiple numbers and multiple different types of data communications with both appliances and subsystems within the home as well as systems external to the home. The system is based upon a central processor, such as a microprocessor-based computer, and is connected by means of a data bus to control the various products and subsystems within a home or commercial building, such as lighting systems, security systems, various sensors, multiple external terminals, as well as to allow for the input of commands by a variety of means such as touch-screens, voice recognition systems, telephones, custom switches or any device capable of providing an input to a computer system. The system functions can be readily controlled by the user utilizing a high resolution graphics display and associated touch-screen interface. U.S. Pat. No. 5,848,634, to Will et al., discloses an apparatus for controlling operation of a motorized window shade, the apparatus comprising a drive circuit for driving an electric motor operating the window shade; and a control circuit for controlling the operation of the driver circuit, the control circuit including a microprocessor. The microprocessor is coupled to first and second switches for enabling driving of the electric motor in respective first and second directions corresponding to upward and downward movement of the window shade. The apparatus also includes a program switch, wherein the microprocessor of the control circuit is programmed to allow setting of the upper and lower limits of travel of the window shade. The microprocessor is also programmed with a program to set a first of the limits of travel. The window shade is adjusted to a desired upper or lower level limit position using at least one of the first and second switches, the program switch is then actuated followed by the actuation of one of the first and second switches to set a first of the limits. The window shade is then adjusted to a desired position for a second of the limits using at least one of the first and second switches. The program switch is again actuated, and the other of the first and second switches is actuated to set the second of the limits. U.S. Pat. No. 5,864,297, to Sollestre et al., discloses a remote keyless entry system including a remote key fob or transmitting unit which may be carried by the user. This fob may transmit coded function signals directing the vehicle to perform requested functions, e.g., unlock the doors, and an on-board receiver that receives the request and performs the function. The receiver may be reprogrammed by the customer to accept signals from a different transmitter in the event that the key fob is either lost or stolen. To program the receiver, the system is put in a programming mode by using a transmitter whose security code is already stored within the receiver. This programming mode is entered by depressing specified buttons on the transmitting unit for a predetermined amount of time. Once in the programming mode, all previous security codes are erased, and a new transmitting unit code may be programmed into the receiver by depressing any button on that unit. The receiver will chime to acknowledge to the customer that the new security code has been accepted. U.S. Pat. No. 6,326,754 to Mullet, et al. discloses a wireless operating system utilizing a multi-functional wall station for a motorized door/gate operator includes an operator for controlling the movement of a door/gate between various positions. The system has an operator with a receiver and a wall station transmitter for transmitting a signal to the receiver. The signal initiates separate operator functions in addition to opening and closing of the door/gate. A remote transmitter may send a remote signal received by the receiver, wherein the receiver is capable of distinguishing between the wall station signal and the remote signal. The wall station includes a transmitter programming button, wherein actuation of the transmitter programming button places the receiver in a learn mode, and wherein subsequent actuation of the remote transmitter positively identifies the remote transmitter for use with the operator. A light powered by the operator and a light actuation button provided by the wall station transmitter is included in the system. Actuation of the light actuation button functions to switch the light on or off. A pet height button, provided by the wall station transmitter, selectively positions the height of the gate/door from its fully closed position to allow ingress and egress of a pet. A delay-close button closes the door/gate after a predetermined period of time. Actuation of a door installation button sequences the door/gate and said operator through various operational parameters to establish a door operating profile. All of the buttons on the wall station are exposed which allows some of them to be accidentally actuated. A keyless entry transmitter and a second wall station may also control the operator. The systems described above are lacking inasmuch as various control elements are provided in different locations. Some are provided at the operator head and some are added on and separate from a main control button or wall station. The add-on devices are susceptible to failure or damage and as such may interfere with the normal operation of system. And if the add-on device is in proximity to other devices the possibility of inadvertent button actuation is substantially increased. This is also true of the few devices which do provide all functions in one location. Indeed, current systems are simply not user friendly in that they can not be seen in the dark nor do they provide sufficient tactile distinctions to enhance their use. Nor do current systems provide an integrated auto-close feature in conjunction with other functions provided on a multi-function wall station. And these systems do not provide both the ability to easily disconnect and/or adjust the timing of the auto-close feature. Finally, the systems do not provide an auto-close feature that can only be enabled if a keyless entry transmitter or other remote transmitter is also taught to the operating system. In summary, current movable barrier operator systems do not provide a complete and integrated functional wall station that is ergonomically designed and efficient in use and operation. DISCLOSURE OF INVENTION It is thus an object of the present invention to provide a wireless transmitter for a door or gate that moves between an open and closed position. The door or gate is of the type that is moveable into an out-of-proximity position with respect to a fixed surface that is to be sealed relative to the door. The door or gate is coupled to a motorized operator which controls movement of the door. It is another object of the present invention to provide a wireless wall station transmitter which provides multiple functions in addition to the open/close function initiated by the motorized operator. It is a further object of the present invention to provide a wireless wall station transmitter device which is powered by a battery or other power source. It is yet another object of the present invention to provide a wireless wall station transmitter which is mountable anywhere in communication range of the motorized operator which controls the up and down movements of the door or gate and various other features associated with the door. It is yet another object of the present invention to provide a receiver coupled to the motorized operator to decode instructions sent from the wall station transmitter. It is still a further object of the present invention to provide a receiver which can handle multiple function instructions. Yet still a further object of the present invention is to provide a radio frequency controlled wireless wall station for controlling the operational parameters of a door or gate operator that contains a plurality of switches or buttons to provide a plurality of functions and features. The wall station transmits an initial signal that sets a series of coded signals during installation and once the encoded series is set, each additional coded message within the coded set designates a separate function. These functions include, but are not limited to, the directional movement of the motorized object; the off and on function of the lights associated with the operator; the initiation of an operational profile, which is used to establish safety limits and the like; the initiation of a delay-to-close time; the raising of the door to a height that allows pet egress; and the learn function programming of additional remote transmitters and remote keyless entry pads. Yet another object of the present invention is to provide additional functions which may include an auto-close feature wherein the auto-close feature is provided with an operator-set or a user-adjustable time period for allowing a door or barrier to remain open for a period of time prior to beginning of closure of the barrier. Still another function may provide for blocking of all other wireless or remote transmitters such that a wall station transmitter is the only transmitter recognized by the operator system. Still yet another object of the present invention is to provide a function that permits the auto-close feature to only be enabled if a keyless transmitter is taught to the operator system. Still yet another object of the present invention is to provide an auto-close feature that is enabled only if a signal is previously received from a remote transmitter or a keyless transmitter. Still further objects of the present invention allow for a wall station to provide a plurality of buttons wherein a certain plurality of buttons are concealed from immediate use. Yet another object of the present invention is to provide a wall station transmitter wherein selected buttons of the transmitter are illuminated for easy identification in a dimly lit environment. Still yet another object of the present invention is to provide for a wall station which provides a cover that is used to conceal the certain plurality of buttons and wherein the cover is movable in the concealing position to allow for actuation of at least one of or a selected number of the concealed buttons. Still yet another object of the present invention is to provide for a wall station wherein the cover that is utilized to conceal at least some of the buttons is selectively illuminated. Another object of the present invention is to provide a detachable cover to enclose batteries within a battery compartment of the wall station housing. In general, the present invention contemplates an operator system for moving a barrier comprising a motor for moving the barrier between opened and closed positions; an operator for controlling operation of the motor; and a wall station having a wall station transmitter for sending operational signals to the operator, the wall station having an open/close button for actuating the motor to move the barrier in the appropriate direction, the wall station also having a manual-close/auto-close selector button, wherein if an auto-close mode is selected the operator automatically closes the barrier if left open for a predetermined period of time. The present invention also contemplates an operator system for moving a barrier comprising a motor for moving the barrier between opened and closed positions; an operator for controlling operation of the motor; and a wall station having a wall station transmitter for sending operational signals to the operator, the wall station having an open/close button for actuating the motor to move the barrier in the appropriate direction, and the wall station also having an auto-close blocking selector button which, if enabled, precludes the operator from receiving operational signals from any source other than the wall station. The invention also contemplates an operator system for moving a barrier comprising a motor for moving the barrier between opened and closed positions; an operator for controlling operation of the motor; a wireless wall station having a wall station transmitter for sending operational signals to the operator, the wireless wall station having an open/close button for actuating the motor to move the barrier in the appropriate direction; and a light source illuminating the wireless wall station from within. The invention further contemplates an operator system for moving a barrier comprising a motor for moving the barrier between opened and closed positions; an operator for controlling operation of the motor; and a wall station having a wall station transmitter for sending operational signals to the operator from a single transceiver, the wall station having an open/close button for actuating the motor to move the barrier in the appropriate direction; the wall station also having a blocking selector button which, if enabled, precludes the operator from receiving operational signals from any source other than the wall station transmitter, the wall station including a panel carrying the open/close switch and the selector switch, and a cover positionable with respect to the panel, wherein the cover in a first position permits access to the switch and in a second position conceals said switches but allows actuation of the open/close switch. The invention further contemplates an operator system for moving a barrier comprising a motor for moving the barrier between opened and closed positions; an operator for controlling operation of the motor; and a wall station having a wall station transmitter for sending operational signals to the operator, the wall station having an open/close button for actuating the motor to move the barrier in the appropriate direction; the operator capable of receiving operational signals from the wall station transmitter and any programmed transmitter; the wall station also having a manual-close/auto-close/block button, wherein if a manual-close mode is selected the operator only closes the door upon receipt of a door close signal from one of the wall station and the programmed transmitter, wherein if an auto-close mode is selected, the operator automatically closes the barrier if left open for a predetermined period of time; and wherein if a block mode is selected, the operator is precluded from receiving operational signals from any source than the wall station transmitter. And the present invention contemplates a wall station for transmitting signals to an operator that moves a motorized barrier, comprising a panel; an open/close button carried by the panel, wherein actuation of the open/close button causes the operator to move the barrier in an appropriate direction; at least one other function button carried by the panel, wherein actuation of the other function button causes the operator to perform the corresponding function; and a cover positionable with respect to the panel, wherein the cover in a first position permits access to the buttons and in a second position conceals the buttons but allows actuation of the open/close button. The invention further contemplates a wall station transmitter for sending operational signals to an operator that controls movement of a barrier comprising a housing having a battery compartment, the housing having a ledge at one end of the battery compartment and a ridge at an opposite end of the battery compartment, the ledge having a groove adjacent a nub, and the ridge having a notch; and a battery cover that detachably encloses the battery compartment, the cover having a catch at one end and a latch of an opposite end, the latch mateably received in the notch and the catch mateably received by the groove. BRIEF DESCRIPTION OF THE DRAWINGS For a complete understanding of the objects, techniques and structure of the invention, reference should be made to the following detailed description and accompanying drawings, wherein: FIG. 1 is an operational system for a motorized barrier operator according to the present invention; FIG. 2 is a front perspective view of a multi-function wall station embodying the concepts of the present invention; FIG. 3 is a rear perspective view of the multi-function wall station; FIG. 4 is a front exploded elevational view of the multi-function wall station with the hinge cover in a closed position; FIG. 5 is a side elevational view of the multi-function wall station with the battery cover removed; FIG. 6 is an operational flowchart setting out the operational steps for the auto-close feature; FIG. 7 is an operational flowchart wherein the auto-close feature is only enabled if an open command is received from an external transmitter; and FIG. 8 is a partial elevational view of the housing's battery compartment with a front panel of the housing removed. PREFERRED EMBODIMENT FOR CARRYING OUT THE INVENTION An operating system for a motorized door or gate operator according to the concepts of the present invention, depicted in FIG. 1 of the drawings, is generally indicated by the numeral 10. The system 10 may be employed in conjunction with a wide variety of movable barrier doors or gates, wherein the doors are of the type utilized in garages, commercial and utility buildings, and other structures, as well as windows or other closure members, all of which may be linear, curved, or otherwise non-linear, in whole or in part. Such barriers or other members are commonly constructed of a variety of materials such as wood, metal, various plastics, or combinations thereof. The lower extremity of doors or other member of these various types may be substantially rectangular or may be profiled in any number of ways for the positioning of reinforcing members or other purposes. In the preferred use, the present invention is utilized with residential-type garage doors. Generally, the system 10 of the present invention employs a multi-function wall station generally designated by the numeral 12. The wall station 12 is typically placed near a pedestrian door that enters the garage from the interior of the house and is positioned at a convenient height, preferably five feet above the ground. The wall station 12 includes a housing typically made of polymeric material, wherein at least a portion of the housing is removable to allow access to the internal workings thereof when needed. The wall station 12 includes a battery compartment 15 (best seen in FIG. 5) for receiving a power supply 16 which is preferably two AAA dry cell batteries. The power supply is used to provide electrical power to various components contained within the wall station as will become apparent as the description proceeds. It will be appreciated that power could be received from a residential power source or equivalent if desired. If such is the case then appropriate transformers will be needed to power the internal components. In any event, use of the dry cell batteries provide the necessary power and allow for the wall station to be placed anywhere within communication range of the operator and eliminates the need for obtaining power directly from the operator or other source. One component which is connected to the power supply is a logic control 18 which is a microprocessor based circuit that provides the necessary hardware, software and memory for implementing the functions to be described. An LED 20 is connected to the logic control and receives power from the power supply 16 in a manner well known in the art. Also connected to the logic control 18 may be a liquid crystal display 22 or other low-power display for providing operational information related to the wall station 12 and/or other components of the operating system 10. The logic control 18 generates various signals 26 which are used by a transmitter 28 for conversion to a radio frequency signal (RF) that is emitted by an antenna 30. Of course other wireless types of signals, such as infrared or acoustic, could be generated by the transceiver 28 if desired. The transmitter may also function as a transceiver to allow for display of operator status information on liquid crystal display 22. As used herein, the term “transceiver” indicates that the device can both transmit and receive wireless signals. In any event, it will be appreciated that in the preferred embodiment the wall station 12 is a wireless device; however, if the need arises a wire could be used to directly transmit the signal 26. The wall station 12 includes a plurality of input switches or buttons designated generally by the numeral 36. These input switches, when actuated, allow the user to control various features of the operating system. The switches 36 include an up/down switch 38; a 3-way selection switch 40, which provides the modes of manual close, auto-close, and radio frequency blocking; an install switch 42; a delay close switch 46; a pet height switch 48; and a light on/off switch 50. The up/down switch 38 is actuated whenever the user wants to move the barrier from an up condition to a down condition or vice versa. The 3-way selection switch 40 provides for different operational modes. Briefly, the manual close mode allows the operating system 10 to operate in much the same manner as would a normal operating system inasmuch as user input is required to open and close the movable barrier. The auto-close feature allows for the movable barrier to close if left in a fully open position for a predetermined period of time and provided that other conditions are met. The radio frequency blocking feature is for when a user is on vacation and desires that no external or remote transmitters allow for operation of the movable barrier. The install switch 42 provides for an installation routine to set the operational limits of the movable barrier with respect to the other physical parameters of the movable barrier. In other words, barrier travel limits and force profiles are generated during the actuation of the install routine. The delay close switch 46 allows for a user to exit the enclosed area within a predetermined period of time without inadvertently actuating safety features such as photoelectric eyes and the like. The pet height switch 48 allows for the door to be moved to a minimal open position of anywhere from 4 to 12 inches to allow the ingress and egress of small pets. The light switch 50 may be activated in either of two directions and turns a light associated with the operating system 10 on or off. The operating system 10 includes an operator which is designated generally by the numeral 56. The operator 56 includes an antenna 58 for receiving the RF signal 32 or any other type of signal associated with other transmitters. In any event, the received radio frequency signal 58 is transmitted to a transceiver 60 which converts the radio frequency signal into a code signal 62 that is received by a controller 64. Alternatively, the controller 64 may receive the data signal 26 directly by a wire as previously discussed. The controller 64 provides the necessary hardware, software and memory for use of the operating system 10. Associated with the controller 64 may be a LED program light 66 which indicates the operational status of the controller 64. The controller 64 is coupled to a motor 68. The controller 64 receives various types of operational signals such as the commands from the various transmitters, safety signals from any connected safety devices, and status signals from the motor to coordinate movement of the barrier. The motor controls movement of the barrier through various drive mechanisms. A light 72 may be associated with the controller 64 for the purpose of illuminating the area enclosed by the barrier. A speaker 73 is also connected to the controller and may be used to announce a programming state or mode. A transmitter program button 74 is connected to the controller for the purpose of allowing programming of the wireless control devices such as the wall station, remote transmitters and the like to the operator 56. The transmitter program button 74 must be actuated to place the operating system in a program mode for the purpose of learning any one of the transmitters disclosed herein to the controller. And a safety sensor 75 may be connected to the controller 64. The sensor 75 may be a photo-electric safety sensor, a door edge sensor or any other sensor that detects application of an excessive force or of an object in the barrier's path by the moving door in either one or both directions. One of the external transmitters that may be associated with the operator 56 is a keyless external transmitter designated generally by the numeral 76. The keyless transmitter 76 provides an antenna 78 for transmitting and, if needed, receiving signals to and from the operator 56. The keyless transmitter 76 includes a keypad 80 which allows for the user to enter a predetermined identification number or code to initiate movement of the barrier. A liquid crystal display 82 may be associated with the keyless transmitter if desired. In any event, upon completion of the entry of the identification number a radio frequency signal 84 is emitted by the antenna 78 and received by the antenna 78 for transmission to the transceiver 60. Another type of external transmitter is a remote transmitter designated generally by the numeral 90. The remote transmitter 90 provides an antenna 92 which emits a radio frequency signal 94 for receipt by the transceiver 60. It will be appreciated that the remote transmitter 90 may include its own controller for the purpose of generating the appropriate radio frequency signal. Fixed code or rolling code technology may be used for communication of the transmitters with respect to the operating system 56. The remote transmitter may include a plurality of function buttons 96 that independently control other features associated with the operating system. In particular, actuation of one of the buttons may be used solely for control of the door/gate or barrier while another of the buttons may independently control the light 72 associated with the operating system or other related features. Referring now to FIGS. 2-5 it can be seen that the wall station 12 utilizes a housing designated generally by the numeral 100. The housing 100, which may either be mounted by a screw, tape or other fastener, is secured to a wall in radio frequency range of the operator and includes a back panel 102 that faces the wall surface. Connected to the back panel 102 is a side panel 104 and a bottom panel 106. A battery cover 108 is coupled to the housing 100 and is preferably positioned on a side opposite the side panel 104. The battery cover 108 is selectively detachable from the housing 100 and retains the power supply 16. The housing 100 also includes a pair of axially extending pins 110 that are preferably positioned at a top edge of the panel 102. Extending from the housing 100 and facing outwardly is a front panel 112 which may be segmented into three sections. One section comprises the light switch 50 and is positioned at a top edge of the housing. The light switch 50 is preferably actuable from two different directions. In other words, if a person desires to actuate just the light 72 associated with the operator 56, then the light switch may be actuated in one of two directions. The light switch can be actuated by applying a downward force or a normal force with respect to the front panel 112. The front panel 112 also includes a recessed panel 116 which is disposed between the light switch 50 and an exposed panel 118. A partition 120 may be provided to separate the recessed panel and the exposed panel. A hinge cover 124 is attached to the housing 100 and is movable with respect thereto. In the preferred embodiment the hinge cover is made of a translucent or transparent polymeric material. The cover 124 includes a pair of opposed collars 126 which slidably rotate about the axial pins 110. If desired, the collars 126 may be cammed in such a way that the cover 124 may be rotatably opened and stay in place while the user accesses the recessed panel 116 without having to manually hold the cover 124. The cover 124 provides an interior surface 128 that faces the recessed panel 116 when the cover is closed. Extending from the interior surface 128 is a projecting nub 130 which functions as a force transmitting member. Also provided in the interior surface 128 is a diffuser 132 which will be discussed in further detail. Opposite the top edge of the hinge cover 124 is a distal edge 134 which nests or mates with the partition 120 when the cover is closed. Opposite the interior surface 128 is an exterior surface 136. Provided on the exterior surface 136 is a depression 138 which is substantially opposite the location of the projecting nub 130. Alternatively, any distinguishable tactile surface may be used in place of the depression. As best seen in FIGS. 4 and 5, when the hinge cover is closed, only the light switch 50, the delay close switch 46 and the pet height switch 48 are exposed. Accordingly, the recessed panel 116 is covered by the cover 124. Those components provided in the recessed panel area 116 include the up/down switch 38, the 3-way selection switch 40, the installation switch 42 and, if provided, the liquid crystal display 22. Also provided in the recessed panel area is a mounting hole 140 which allows for receipt of a screw or fastener for mounting of the wall station to the desired surface. Also provided on the recessed panel 116 is a light pipe 142 which transmits light illuminated by the light emitting diode or diodes 20. During operation, the LED's 20 blink at a predetermined rate of about once per second. With the hinge cover closed, the LED's emit a light that is captured by the light pipe 142. The diffuser 132 is positioned directly over the light pipe when the cover is closed and light is emitted outwardly therefrom. Accordingly, in a darkened enclosure area, the user can easily find the location of the wall station when the cover is illuminated so as to allow for actuation of the light switch 50. And with the hinge cover in the closed position it will be appreciated that all of the buttons maintained on the recess panel are covered and not readily accessible. However, by providing a projecting nub 130 opposite the depression area 138 a user can easily find this depression area from the light emitted by the LEDs and by pressing the depression area 138 a resulting force is transmitted by the nub 130 to actuate the switch 38. Accordingly, the hinge cover itself functions as an open/close button when the cover is in a closed position. When the cover is in a closed position and pressed it is allowed to rotate or move as needed so as to permit full actuation of the switch 38 without actuating any of the other buttons or damaging any of the components maintained on the recess panel 116. The hinge cover is made of a translucent or transparent material so that the LEDs may illuminate the entire surface of the hinge cover. However, if desired, a label may be placed on the inside surface of the hinge cover to provide instructions to the user. The diffuser area 132 will not be covered by the label so as to permit transmission of light from the light pipe 142 through the cover so as to be viewable by the user. With the hinge cover in the closed position, the user may access four of the buttons associated with operation of the operating system 56. In particular, the user may actuate the light switch 50 by pressing the top edge or front top edge of the housing. The second button that may be actuated is the up/down switch by pressing the hinge cover so as engage the button 38 with the force member 130. The other two exposed buttons are the delay closed switch 46 and the pet height switch 48. The hinge cover 124 allows for selected concealment of the other switches maintained on the recess panel as previously indicated. The 3-way selection button 40 provides for three different options as determined by the end user. The first option, which is a default option, is for the manual close of the barrier. In other words, in this mode the user is only able to open and close the door by actuating the up/down switch 38, or by actuation of the remote transmitter 90 or the keypad transmitter 76 that has been programmed to the operator. In the second mode, the user may select an auto-close embodiment. In this mode the garage door or barrier may close after a predetermined period of time from its placement in an open position. This allows the user to have a level of confidence that the enclosure surrounded by the barrier is closed after a period of time in the event that a down button is forgotten to be pushed after leaving the garage, or the garage is left open after entering the building. In order for this feature to be fully enabled in a preferred embodiment, the switch is placed in the auto-close mode, whereupon the operator will respond by blinking the light 72 or emitting an audible sound from the speaker 73 for a predetermined period of time such as 60 seconds. During this time a correct identification number must be entered on the keypad 76. If the ID number is accepted, confirmation of the auto-close feature is communicated by flashing the light 72 on and off a predetermined number of times. While in the auto-close mode all other programmed transmitters may be used to control movement of the barrier. Requiring the programming of the keypad 76 ensures that the user has some way of re-entering the area enclosed by the barrier in the event of closure. The third option for the 3-way selector switch is disablement of all operator operation except for return to one of the other two modes provided by the switch. This may also be referred to as a “vacation lock” mode wherein the opener operating system 10 will not respond to any transmitter open signal. In other words, the only way to open and/or close the barrier is by moving the 3-way selector back to the default manual open/close switch or to the auto-close position followed by activation of the open/close switch of a transmitter or wall station up/down command. Open or close signals received from the programmed transmitters, whether the wall station, a hand held remote or a keyless entry pad, will be ignored by the controller 64. Referring now to FIG. 6, it can be seen that an operational flow chart designating steps for enabling an auto-close feature is designated generally by the numeral 150. Initially, at step 151, the controller cycles through a main loop and the steps taken herein are a portion of that main loop. At step 152, a timer is investigated to determine whether a predetermined period of time has expired which in the preferred embodiment is one hundred twenty minutes. If the timer has not expired, the flow chart returns to step 151. If, however, it is determined that the one hundred twenty minute timer has expired the process proceeds to step 153. The following three steps are queried to determine whether the necessary requirements are in place for initiation of an auto-close door movement. Accordingly, at step 153 the process determines whether the door is in a complete up position resulting from a standard open operation. In other words, the controller determines whether the door is in a fully up limit position and confirms that the door is in this up position as a result of a normal door operation. If the door is in the up position as a result of safety reversal or interrupted auto-close door movement then the process is returned to the main loop 151 until such time that a correct and successful door open operation is completed. Following step 153 the controller determines whether a keypad transmitter has been programmed to operate the controller at step 154. If not, the process proceeds or returns to step 151. If a keypad transmitter has been properly entered then the process continues on to step 155 to confirm that the auto-close switch has been selected and that a valid keypad transmitter has been received after the auto-close switch position has been selected. If not, the process again returns to step 151. If however, the auto-close feature has been determined to be -enabled at step 155 then the process proceeds to step 156 where a first warning is initiated. This warning may be in the form of flashing of the light 72 or emission of a series of beeps from an audible speaker if connected to the controller. If during the warning signal period of about 10 seconds or some other time period a control input is received at step 157, then at step 158 the auto-close procedure is terminated and temporarily disabled and the process returns to step 151. This temporary disablement of the auto-close feature is discontinued upon a correct and successful door open operation. In any event, upon completion of the warning signal period at step 159 lo a first door down movement or increment, at step 160, is initiated. This results in the door moving a predetermined length of travel such as three to six inches from the fully-open limit position and the controller initiates a stop and pause and then initiates a second warning period of about 10 seconds or some other time period at step 161. If any type of control input is then received at step 162 during the warning period then at step 163 the auto-close procedure is terminated and once again that feature is temporarily disabled. The process then continues at step 164 and the door is returned to its fully open position and then the process returns to step 151. This temporary disablement is not withdrawn until a successful open procedure is implemented. If however, at step 165 the second warning period is completed without any control input being received then the process proceeds to step 166 and a complete door closing procedure is implemented. In a variation of the foregoing process, it will be appreciated that the process may continue at step 167—from step 165—and only move down an increment so as to periodically move the door, issue a warning, and then move the door again. Accordingly, the door is closed after completion of a series of door movement increments. This feature is envisioned for use where the door's downward force is at a higher level and the incremental movement provides an added precaution. If it is desired, the controller 64 may be programmed so as to allow the user to adjust the timer associated with the auto-close function. This may be implemented in any number of ways and an exemplary way would likely incorporate opening the cover so as to expose the buttons on the recess panel. The user might then simultaneously hold one or more of the buttons wherein the display 22 provides the information regarding the amount of time associated with the auto-close feature. It is envisioned that the auto-close feature would be limited to a range of time such as from fifteen minutes to two hours. The display could also provide an operational status of the system. Referring now to FIG. 7, operational steps are designated generally by the numeral 170 for an embodiment which is automatically initiated by the controller. In other words, the auto-close feature is only enabled upon actuation of an open command from an “external transmitter,” which in this embodiment means the keyless transmitter or any remote transmitter. For example, any transmitter other than a wall station transmitter. At step 172 a barrier open command is received by the controller and the door is opened. Next, at step 174, the controller determines from what type of transmitter device the open command was received from. If the open command was not received from an external transmitter, in other words, the open command was received from the wall station, then the process proceeds to step 176 to continue with normal operation. If however, at step 174, the opening command was received from an external transmitter such as a keyless entry device or a remote transmitter then the process proceeds to step 178 and the auto-close timer is enabled. At step 178, the auto-close timer is continually queried as to whether the timer has expired and once it has, then the process proceeds to step 180 so as to execute the auto-close steps designated in the flow-chart 150. The process then continues at step 176 and proceeds with the other features of the control system. This feature of the system ensures that the door will not be inadvertently closed unless the user has the ability to re-open the barrier with a keyless entry device or a remote transmitter. Additionally, it will be appreciated that the specific type of external transmitter may be specified in the controller software program and wherein the preferred embodiment the type of external transmitter is limited to a keyless entry device. Referring now to FIGS. 4, 5 and 8 it can be seen that the battery cover 108 is detachably securable to the housing 100. The housing includes the back panel 102 from which extends a back ledge 200 and a panel ledge 202. The back ledge 200 extends from the back panel 102 toward the front panel 112 at the bottom edge of the housing while the panel ledge 202 extends from the front panel toward the back panel. In a similar manner, a back ridge 204 extends from the back panel toward the front panel and a panel ridge 206 extends from the front panel 112 toward the back panel 102 at a top edge of the housing. It will be appreciated that the back ledge 200 and the panel ledge 202 form a substantially continuous ledge from the back panel toward the front panel. In a similar manner, the panel back ridge 204 and the panel ridge 206 form a substantially continuous ridge. The ledges 200, 202; the ridges 204, 206; and the panels 102, 112 define the battery compartment 15. Included within the battery compartment 15 is a hinge cavity 210. The back panel provides a panel edge surface 212 from which extends the ledge 200. The ledges include a nub 214 which does not extend fully to the outer periphery of the edge surface 212. Adjacent the nub 214 and positioned inwardly toward the hinge cavity 210 is a groove 216. The groove 216 provides a catch surface 218 and a stop surface 220 which forms a portion of the nub 214. The ridges 204, 206 form a notch 222 within the battery compartment 15. The cover 108 is detachably secured to the housing 100 and in particular it covers the battery compartment 208 including the hinge cavity 210. As best seen in FIGS. 4 and 8, the battery cover includes a wall 224 which has a plurality of inwardly extending ribs 226 along the inwardly facing surface thereof. The ribs 226 function to securely hold the batteries 16 in place with the cover 108 attached to the housing. The wall 224 includes a catch 228 at a bottom end and a latch 230 at a top end. The latch 230 extends inwardly—in the same direction as the ribs 226—and upwardly from a top edge of the wall 224 and is receivable in the notch 222. The catch 228 includes a U-shaped member 234 which includes a pivot point 236. Extending from the pivot point is a lever arm 238 from which extends a retainer 240 that has a ramp surface 244 and a corner surface 246. Also extending in the same direction as the retainer 240 is a finger 250 which preferably does not extend beyond the panel edge surface 212 when the cover is installed. Formed between the retainer 240 and the finger 250 is a slot 248. When the battery cover 108 is installed, the retainer 240 is mateably received within the groove 216 and the nub 214 is received in the slot 248. Moreover, the corner surface 246 is in juxtaposition to the stop surface 220 while the ramp surface 244 is in juxtaposition to the catch surface 218. After the batteries 16 are installed in the compartment 15 the cover is installed by first angularly positioning the latch 230 into the notch 222. The cover 108 is then rotated inwardly so that the U-shaped member 234 is received into the hinge cavity 210. As the lever arm 238 engages the ledges 200, 202, the ramp surface 244 contacts the nub 214. At this time lever arm 238 is deflected at the pivot point 236 until such time that the retainer 240 clears the nub 214. As soon as the corner surface 246 passes the trailing edge of the nub 214, the retainer 240 is received in the groove 216 by virtue of the spring-like nature of the catch 234. Likewise, the slot 248 is nested around the nub 214 wherein the finger 250 partially surrounds the nub. Removal of the battery cover is essentially accomplished by reversal of the above steps. In particular, the user will insert their fingernail or some other force transmitting member between the finger and the nub so as to deflect the lever arm upwardly at the pivot point. This disengages the catch 228 from the groove 216. The catch 228 is then moved such that the latch 230 rotates slightly and then the cover is withdrawn from the notch 222. It will be appreciated that the battery cover construction, which is mateable with the housing 100, is advantageous inasmuch as the catch mechanism has two mating or nesting surfaces. In particular, the retainer 240 is received in the groove 216 while the nub 214 is received in the slot 248. Accordingly, this construction along with the flexible nature of the catch allows for easy removal of the cover without the need for other tools such as a screwdriver which would otherwise damage the battery cover. Accordingly, the present construction is an improvement over previously known battery covers employed with wall station transmitters. Based upon the foregoing, the advantages of the present invention are readily apparent. In regard to the multi-function wall station, it provides a means for disabling the operator from receiving radio frequencies or other wireless transmission signals for all operational commands of the operator from any “external” transmitter. And the 3-way selection switch provides a way to activate and deactivate the auto-close feature. The lighted feature of the wall station is also believed to be unique inasmuch as it assists the user finding the wall station in a dimly lit environment. Yet another advantage of the present invention is that the up/down button is associated with a hinged cover that prevents accidental depression of the other operational controls which are not commonly used. Still yet another advantage of the present invention is that two different motions are allowed to activate the operator-controlled garage lights wherein one of the switches is along the top of the wall station that can be located by sliding one's hand down the wall to activate and the other of the switches is on the outward face of the wall station for conventional horizontal motion activation. The wall station being battery powered also provides the benefit of eliminating the need for a wired wall station so as to remove unsightly wires and to significantly reduce installation time of the unit. In this regard, the wall station housing can be placed in any unrestricted location as long as it is within range of the wireless signal in communication with operator and within sight of the door. The invention is also advantageous in that the auto-close feature is provided directly with the operator control systems. As such, additional add-on components are not required for operation of the auto-close feature and the operation of the auto-close feature is greatly improved in regard to durability and implementation of all the other features in combination therewith. The delay function is adjustable if desired and the auto-close feature can be disabled or disarmed and returned to a manual-remote operation if needed. Still yet another advantage of the present invention is that it may only be enabled and operational if a keyless entry transmitter has been taught to the garage door operator. Accordingly, if the user is outside of the garage or house and the auto-close feature automatically closes the garage door that person can use the externally mounted keyless entry transmitter to open the garage door. Conversely, if a keyless entry transmitter has not been taught to the garage door operator then the door will never close automatically by the auto-close feature. Yet another embodiment of the present invention is advantageous in that the auto-close timer is only activated if the door has received a command to move from a remote transmitter such as a hand-held transmitter or a keyless entry keypad. Thus, it can be seen that the objects of the invention have been satisfied by the structure and its method for use presented above. While in accordance with the Patent Statutes, only the best mode and preferred embodiment has been presented and described in detail, it is to be understood that the invention is not limited thereto or thereby. Accordingly, for an appreciation of the true scope and breadth of the invention, reference should be made to the following claims. | <SOH> BACKGROUND ART <EOH>As is well known, garage doors or gates enclose an area to allow selective ingress and egress to and from the area. Garage doors initially were moveable by hand. But due to their weight and the inconvenience of opening and closing the door, motors are now connected to the door. Control of such a motor may be provided by a hard-wired push button which, when actuated, relays a signal to an operator controller that starts the motor and moves the door in one direction until a limit position is reached. After the door has stopped and the button is pressed again, the motor moves the door in an opposite direction. Garage door operators are now provided with safety features which stop and reverse the door travel when an obstruction is encountered. Other safety devices, such as photocells and sensors, detect whenever there is an obstruction within the path of the door and send a signal to the operator to take corrective action. Remote control devices are now also provided to facilitate the opening and closing of the door without having to get out of the car. The prior art also discloses various other features which enhance the convenience of opening and closing a garage door as follows. U.S. Pat. No. 4,119,896, to Estes, III et al., discloses a sequencing control circuit provided for a door operator motor which is connected to open and close a garage door as controlled by signals from manual switches and load switches. The sequencing control circuit includes time means with a first time period in the order of six to eight seconds. This permits a person to hold a push button switch closed for about six to eight seconds so that a slab door may be opened against a snow drift which otherwise would have so much torque requirement on the motor that an overload switch would stop the motor. Enabling means is provided to enable the motor during this time period yet to disable the constant signal from the push button for periods longer than this time period so that the door operator motor then is responsive to signals from the load switches. The sequencing control circuit also includes a latch circuit having an output in a feedback loop to maintain the latch circuit latched upon a momentary input control signal. This allows time for the motor to accelerate the load to a normal running condition and to open any closed limit switch or closed torque switch during this acceleration period. U.S. Pat. No. 4,247,806, to Mercier, discloses a garage door opener including a radio receiver and a push button, each operable to initiate a pulse for effecting a switching device which, in turn, energizes a latching relay. Operation of the latching relay completes an energizing circuit to the appropriate winding of a reversible motor which moves the door toward an open or closed position. A sensing circuit is operable for effecting the reversal of the latching relay to change the direction of motor operation in the event the door engages an object in its path. A foot switch may also be provided for positively sensing an obstacle and reversing the drive motor. A transmitter may be provided with an impulse circuit to limit the duration of the system actuating signal regardless of how long the transmitter push button is depressed. U.S. Pat. No. 4,607,312, to Barreto-Mercado, discloses a system that eliminates the conventional automobile door and trunk locks and provides power operated locks remotely controlled by a VHF radio transmission which is coded with two code signals, one of which energizes the door locks to locking condition and the other of which causes door or trunk unlocking, the trunk unlocking being activated only if a trunk transfer push button switch has been operated. The unlocking code may also activate the electric power to the engine starter motor, hood and manual switches of the power door operating motor. The system provided by the invention for unlocking or locking the doors of an automobile and for unlocking the trunk and hood of the same automobile as well as the engine electric power, all from outside the automobile permits the removal of the conventional mechanical door locking mechanism, including both the external key-operated apparatus and that controlled by an internal push button, and the removal of the conventional key-operated mechanical trunk lock, and the substitution of an externally operable radio controlled lock and unlock system for the door and an unlock system for the trunk and hood. U.S. Pat. No. 4,808,995, to Clark et al., discloses a radio remote-controlled door operator for use, among other uses, as a residential garage door operator. The transmitter contains two buttons, one to produce normal door operation and the other to set the operator into a “secure” mode, wherein it will be non-responsive to further valid operating codes until reset. In addition, a second deeper level of security may be established by means of a vacation switch which disconnects the operator from the AC power supply. The operator system comprises a microprocessor which is programmed to perform various accessory functions even through the accessories may not be present. Various microprocessor inputs are tied to a false “safe” level so that even though the accessory programs are run, no outputs result and no interference with normal door operation is produced. U.S. Pat. No. 5,086,385, to Launey et al., discloses a system for and a method of providing an expandable home automation controller which supports multiple numbers and multiple different types of data communications with both appliances and subsystems within the home as well as systems external to the home. The system is based upon a central processor, such as a microprocessor-based computer, and is connected by means of a data bus to control the various products and subsystems within a home or commercial building, such as lighting systems, security systems, various sensors, multiple external terminals, as well as to allow for the input of commands by a variety of means such as touch-screens, voice recognition systems, telephones, custom switches or any device capable of providing an input to a computer system. The system functions can be readily controlled by the user utilizing a high resolution graphics display and associated touch-screen interface. U.S. Pat. No. 5,848,634, to Will et al., discloses an apparatus for controlling operation of a motorized window shade, the apparatus comprising a drive circuit for driving an electric motor operating the window shade; and a control circuit for controlling the operation of the driver circuit, the control circuit including a microprocessor. The microprocessor is coupled to first and second switches for enabling driving of the electric motor in respective first and second directions corresponding to upward and downward movement of the window shade. The apparatus also includes a program switch, wherein the microprocessor of the control circuit is programmed to allow setting of the upper and lower limits of travel of the window shade. The microprocessor is also programmed with a program to set a first of the limits of travel. The window shade is adjusted to a desired upper or lower level limit position using at least one of the first and second switches, the program switch is then actuated followed by the actuation of one of the first and second switches to set a first of the limits. The window shade is then adjusted to a desired position for a second of the limits using at least one of the first and second switches. The program switch is again actuated, and the other of the first and second switches is actuated to set the second of the limits. U.S. Pat. No. 5,864,297, to Sollestre et al., discloses a remote keyless entry system including a remote key fob or transmitting unit which may be carried by the user. This fob may transmit coded function signals directing the vehicle to perform requested functions, e.g., unlock the doors, and an on-board receiver that receives the request and performs the function. The receiver may be reprogrammed by the customer to accept signals from a different transmitter in the event that the key fob is either lost or stolen. To program the receiver, the system is put in a programming mode by using a transmitter whose security code is already stored within the receiver. This programming mode is entered by depressing specified buttons on the transmitting unit for a predetermined amount of time. Once in the programming mode, all previous security codes are erased, and a new transmitting unit code may be programmed into the receiver by depressing any button on that unit. The receiver will chime to acknowledge to the customer that the new security code has been accepted. U.S. Pat. No. 6,326,754 to Mullet, et al. discloses a wireless operating system utilizing a multi-functional wall station for a motorized door/gate operator includes an operator for controlling the movement of a door/gate between various positions. The system has an operator with a receiver and a wall station transmitter for transmitting a signal to the receiver. The signal initiates separate operator functions in addition to opening and closing of the door/gate. A remote transmitter may send a remote signal received by the receiver, wherein the receiver is capable of distinguishing between the wall station signal and the remote signal. The wall station includes a transmitter programming button, wherein actuation of the transmitter programming button places the receiver in a learn mode, and wherein subsequent actuation of the remote transmitter positively identifies the remote transmitter for use with the operator. A light powered by the operator and a light actuation button provided by the wall station transmitter is included in the system. Actuation of the light actuation button functions to switch the light on or off. A pet height button, provided by the wall station transmitter, selectively positions the height of the gate/door from its fully closed position to allow ingress and egress of a pet. A delay-close button closes the door/gate after a predetermined period of time. Actuation of a door installation button sequences the door/gate and said operator through various operational parameters to establish a door operating profile. All of the buttons on the wall station are exposed which allows some of them to be accidentally actuated. A keyless entry transmitter and a second wall station may also control the operator. The systems described above are lacking inasmuch as various control elements are provided in different locations. Some are provided at the operator head and some are added on and separate from a main control button or wall station. The add-on devices are susceptible to failure or damage and as such may interfere with the normal operation of system. And if the add-on device is in proximity to other devices the possibility of inadvertent button actuation is substantially increased. This is also true of the few devices which do provide all functions in one location. Indeed, current systems are simply not user friendly in that they can not be seen in the dark nor do they provide sufficient tactile distinctions to enhance their use. Nor do current systems provide an integrated auto-close feature in conjunction with other functions provided on a multi-function wall station. And these systems do not provide both the ability to easily disconnect and/or adjust the timing of the auto-close feature. Finally, the systems do not provide an auto-close feature that can only be enabled if a keyless entry transmitter or other remote transmitter is also taught to the operating system. In summary, current movable barrier operator systems do not provide a complete and integrated functional wall station that is ergonomically designed and efficient in use and operation. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>For a complete understanding of the objects, techniques and structure of the invention, reference should be made to the following detailed description and accompanying drawings, wherein: FIG. 1 is an operational system for a motorized barrier operator according to the present invention; FIG. 2 is a front perspective view of a multi-function wall station embodying the concepts of the present invention; FIG. 3 is a rear perspective view of the multi-function wall station; FIG. 4 is a front exploded elevational view of the multi-function wall station with the hinge cover in a closed position; FIG. 5 is a side elevational view of the multi-function wall station with the battery cover removed; FIG. 6 is an operational flowchart setting out the operational steps for the auto-close feature; FIG. 7 is an operational flowchart wherein the auto-close feature is only enabled if an open command is received from an external transmitter; and FIG. 8 is a partial elevational view of the housing's battery compartment with a front panel of the housing removed. detailed-description description="Detailed Description" end="lead"? | 20040206 | 20070206 | 20050811 | 57699.0 | 1 | BANGACHON, WILLIAM L | Operating system for a motorized barrier operator | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,773,541 | ACCEPTED | Model stamping matrix check technique in circuit simulator | The present invention includes a method for detecting model stamping errors during circuit simulation without the need for golden data. The method checks for model stamping errors by determining whether entries in model stamping matrices interrelate according to a plurality of preset rules before circuit equations are solved. | 1. A method for evaluating a device model for a circuit element, comprising: supplying a first set of terminal biases associated with the circuit element; obtaining a first set of model results based on the first set of terminal biases; and checking for correctness of the first set of model results by determining whether the first set of model results interrelate according to a plurality of rules. 2. The method of claim 1 wherein the first set of model results include a current vector and a charge vector having a plurality of entries, and wherein determining whether the model results interrelate according to the plurality of rules comprises determining whether the sum of the plurality of entries is zero. 3. The method of claim 1 wherein the first set of model results include a charge vector having a plurality of entries, and wherein determining whether the first set of model results interrelate according to the plurality of rules comprises determining whether the sum of the plurality of entries is zero. 4. The method of claim 1 wherein the first set of model results include a conductance matrix having a plurality of rows of entries, and wherein determining whether the first set of model results interrelate according to the plurality of rules comprises determining whether the sum of the entries in each of the plurality of rows of entries is zero. 5. The method of claim 1 wherein the first set of model results include a conductance matrix having a plurality of columns of entries and wherein determining whether the first set of model results interrelate according to the plurality of rules comprises determining whether the sum of the entries in each of the plurality of columns of entries is zero. 6. The method of claim 1 wherein the first set of model results include a capacitance matrix having a plurality of rows of entries, and wherein determining whether the first set of model results interrelate according to the plurality of rules comprises determining whether the sum of the entries in each of the plurality of rows of entries is zero. 7. The method of claim 1 wherein the first set of model results include a capacitance matrix having a plurality of columns of entries, and wherein determining whether the first set of model results interrelate according to the plurality of rules comprises determining whether the sum of the entries in each of the plurality of columns of entries is zero. 8. The method of claim 1 wherein the first set of model results include a conductance matrix having a plurality of diagonal entries, and wherein determining whether the first set of model results interrelate according to the plurality of rules comprises determining whether each diagonal entry is non-negative. 9. The method of claim 1 wherein the first set of model results include a capacitance matrix having a plurality of diagonal entries, and wherein determining whether the first set of model results interrelate according to the plurality of rules comprises determining whether each diagonal entry is non-negative. 10. The method of claim 1 wherein the first set of model results are stamped into designated positions in matrices associated with equations for simulating the system. 11. The method of claim 1, wherein checking for correctness of the first set of model results further comprises: supplying a second set of terminal biases that is slightly different from the first set of terminal biases; obtaining a second set of model results based on the second set of terminal biases; and checking for correctness of the first set of model results based on differences between the first set of model results and the second set of model results and on differences between the first set of terminal biases and the second set of terminal biases. 12. The method of claim 11 wherein all except one of the second set of terminal biases are equal to respective ones of the first set of terminal biases. 13. A method for simulating a system having a large number of elements interconnected through their terminals, some or all of the elements are modeled by element models each for generating model results describing characteristic of an element under a set of terminal conditions; comprising: obtaining a first set of model results associated with an element in the system based on a first set of terminal conditions for the element; and checking for correctness of the first set of model results by determining whether the first set of model results interrelate according to a plurality of rules. 14. The method of claim 13 wherein the model results are stamped into designated entries in matrices associated with a set of matrix equations that simulate the system and the method further comprising: obtaining solutions for states of the system by solving the set of matrix equations. 15. The method of claim 14, further comprising: forming a second set of terminal conditions for the element based on the solutions for the states of the system; obtaining a second set of model results associated with the element based on the second set of terminal conditions for the element; and checking for correctness of the second set of model results by determining whether the second set of model results interrelate according to the plurality of rules. 16. A computer readable medium storing therein computer readable program instructions that, when executed by a computer, cause the computer to perform a method for evaluating a device model for a circuit element, the computer readable program instructions comprising: instructions for supplying a first set of terminal biases; instructions for obtaining a first set of model results based on the first set of terminal biases; and instructions for checking for correctness of the first set of model results by determining whether the first set of model results interrelate according to a plurality of rules. 17. The computer readable medium of claim 16 wherein the first set of model results include a current vector and a charge vector each having a plurality of entries, and wherein the instructions for determining whether the model results interrelate according to the plurality of rules comprises: instructions for determining whether the sum of the plurality of entries in the current vector is zero; and instructions for determining whether the sum of the plurality of entries in the charge vector is zero. 18. The computer readable medium of claim 16 wherein the first set of model results include a conductance matrix and a capacitance matrix each having a plurality of rows of entries and a plurality of columns of entries, and wherein the instructions for determining whether the first set of model results interrelate according to the plurality of rules comprises: instructions for determining whether the sum of the entries in each of the plurality of rows of entries in the conductance matrix is zero; instructions for determining whether the sum of the entries in each of the plurality of columns of entries in the conductance matrix is zero; instructions for determining whether the sum of the entries in each of the plurality of rows of entries in the capacitance matrix is zero; instructions for determining whether the sum of the entries in each of the plurality of columns of entries in the capacitance matrix is zero; instructions for determining whether each diagonal entry in the conductance matrix is non-negative; and instructions for determining whether each diagonal entry in the capacitance matrix is non-negative. 19. The computer readable medium of claim 16, wherein the instructions for checking for correctness of the first set of model results further comprises: instructions for supplying a second set of terminal biases that is slightly different from the first set of terminal biases; instructions for obtaining a second set of model results based on the second set of terminal biases; and instructions for checking for correctness of the first set of model results based on differences between the first set of model results and the second set of model results and on differences between the first set of terminal biases and the second set of terminal biases. 20. The computer readable medium of claim 19 wherein all except one of the second set of terminal biases are equal to respective ones of the first set of terminal biases. | The present invention relates to large sparse linear systems arising in the simulation of physical and other phenomena, such as an integrated circuit including circuit elements represented by matrix stamps in a system of matrix equations. BACKGROUND The development of complicated physical systems often requires powerful numerical simulation programs. For example, circuit simulation is now an essential part in the design flow of integrated circuits. It helps circuit designers to verify the functionality and performance of their designs without going through expensive fabrication processes. Examples of electronic circuit simulators include the Simulation Program with Integrated Circuit Emphasis (SPICE) developed at the University of California, Berkeley (UC Berkeley), and various enhanced versions or derivatives of SPICE, such as, SPICE2 or SPICE3, also developed at UC Berkeley; HSPICE, developed by Meta-software and now owned by Synopsys; PSPICE, developed by Micro-Sim; and SPECTRE, developed by Cadence. The SPICE and its derivatives or enhanced versions will be referred to hereafter as SPICE circuit simulators, or SPICE. An electronic circuit is a network of circuit elements such as resistors, capacitors, inductors, mutual inductors, transmission lines, diodes, bipolar junction transistors (BJT), junction field effect transistors (JFET), metal-oxide-semiconductor field effect transistors (MOSFET), metal-semiconductor field effect transistors (MESFET), thin-film transistors (TFT), etc. SPICE usually handles a circuit in a node/element fashion, i.e., the circuit is regarded as a collection of various circuit elements connected at nodes. At the heart of SPICE is the so-called Nodal Analysis, which is accomplished by formulating nodal equations (or circuit equations) in matrix format to represent the circuit and solving the nodal equations. The circuit elements are modeled by device models, which produce model results that are represented in the circuit equations as matrix stamps. A device model for modeling a circuit element, such as the BSIM4 model for modeling MOSFET devices developed by UC Berkeley, typically includes model equations and a set of model parameters to mathematically represent characteristics of the circuit element under various bias conditions. For example, a circuit element with n terminals can be modeled by the following current-voltage relations: Ii=fi(V1, . . . , Vn, t) for i=1, . . . , n, where Ii represents the current entering terminal i, Vj (j=1 , . . . , n) represents the voltage or terminal bias across terminal j and a reference terminal, such as the ground, and t represents the time. The Kirchhoff's Current Law implies that the current entering terminal n is given by I n = ∑ i = 1 n - 1 I i . A conductance matrix of the circuit element is defined by: G ( V 1 , … , V n , t ) := ( ∂ f 1 ∂ V 1 ⋯ ∂ f 1 ∂ V n ⋮ ⋰ ⋮ ∂ f n ∂ V 1 ⋯ ∂ f n ∂ V n ) . To model the circuit element under alternating current (AC) operations, the device model also considers the relationship between node charges and the terminal biases: □Qi=qi(V1, . . . , Vn, t) for i=1, . . . , n. where Qi represents the represents the node charge at terminal i. Thus, the capacitance matrix of the n-terminal circuit element is defined by C ( V 1 , … , V n , t ) := ( ∂ q 1 ∂ V 1 ⋯ ∂ q 1 ∂ V n ⋮ ⋰ ⋮ ∂ q n ∂ V 1 ⋯ ∂ q n ∂ V n ) . For non-linear circuits, i.e., circuits including non-linear devices, SPICE often solves the circuit equations using the so-called Newton-Ralphson (N-R) iteration. To start the iteration process, SPICE selects an initial operating point for which the device model is evaluated. The initial operating point may include a set of terminal biases Vj(j=1, . . . , n) associated with each of a plurality of circuit elements. Based on the set of terminal biases for each of the circuit elements, SPICE evaluates the device models for modeling the circuit elements and produces model results such as terminal currents, node charges and the derivatives of the terminal currents and node charges (conductance and capacitance) associated with the circuit elements. SPICE then stamps the terminal currents, node charges, and their derivatives into designated entries in the matrices of the circuit equations. The process of obtaining model results and stamping the model results into matrices are often referred to as model evaluation and model stamping or matrix stamping. SPICE then solves the circuit equations to produce circuit voltages and currents based on the initial operating point. The circuit voltages and currents based on the initial guess of the operating point are used to generate a second operating point, and SPICE then iterates the above process to solve the circuit equations based on the second operating point. The iteration continues until the differences in circuit voltages and currents from two consecutive iteration rounds have fallen below some predetermined limits, and the solution is considered to have converged. Thus, the correctness and the efficiency of circuit simulation depend on the correct implementation of the device models and correct stamping of the model results. For example, a basic requirement for the convergence of N-R iteration is the consistency between the terminal currents, node charges and their derivatives, which can be destroyed due to errors in the stamping of conductance or capacitance. As the technology advances and integrated circuits become more and more complex, it has become more and more difficult to guarantee the correct stamping of the model results. Usually, extensive model quality assurance (QA) procedures are followed after model evaluation to compare model results with golden data, which are obtained by measurements, by using a slower but more reliable simulation tool such as an electromagnetic field solver, or simply from a previous circuit simulation run. But this model QA method is disadvantageous because it depends on the quality of the golden data, which may be erroneous or simply unavailable, as in cases involving new technology and state-of-art device models. Even when the golden data are available and reliable, conventional model QA procedures are still insufficient because the golden data are typically obtained by DC sweep of bias voltages and because conventional model QA procedures often use DC solution of the model equations for comparison with the golden data. As a result, conventional model QA procedures cannot detect errors in matrix stamping of conductance or capacitance entries because these errors have no effect on the accuracy of DC solutions. The errors in matrix stamping of conductance or capacitance entries will, however, affect the convergence and speed of the circuit simulation and should be detected before they are used to solve the circuit equations. Furthermore, conventional model QA procedures are insufficient because they do not provide 100% bias coverage. The DC solution of the model equations and the comparison with golden data are usually performed for typical biases only. Moreover, conventional mode QA procedures do not test the consistency between currents, charges and their derivatives (conductance and capacitance), which is crucial for the convergence of N-R iteration. SUMMARY The present invention includes a method for detecting model stamping errors during circuit simulation. In one embodiment of the present invention, the method is implemented in a circuit simulator for simulating an integrated circuit having various interconnected circuit elements. The circuit simulator includes a model engine module (model engine) and a solver module (solver). The model engine includes device models for modeling the circuit elements and is programmed to produce model results associated with a circuit element based on the set of terminal biases for the circuit element supplied by the solver. The solver is programmed to form circuit equations in matrix format, to supply the set of terminal biases for each of a plurality of circuit elements represented in the circuit equations to the model engine, to receive the model results produced by the model engine, to stamp the model results into designated entries in matrices associated with the circuit equations, to check for correctness of the stamped model results by determining whether the model results interrelate according to a plurality of preset rules, and to solve the circuit equations to produce circuit simulation results. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a computer system that can be used to carry out a method according to one embodiment of the present invention. FIG. 2 is a block diagram illustrating a circuit simulation program according to one embodiment of the present invention. FIG. 3 is a flowchart illustrating a process for simulating an integrated circuit according to one embodiment of the present invention. FIG. 4 is a flowchart illustrating a process for checking local variable matrices according to one embodiment of the present invention. FIG. 5 is an equivalent circuit in the BSIM4 model for modeling MOSFET devices for illustrating an application of the present invention. DETAILED DESCRIPTION The present invention includes a method for simulating a system by solving for the states of the system having a large number of elements interconnected through their terminals, some or all of which are modeled by element models each for generating model results describing the behavior or characteristic of an element in the system under a set of terminal conditions. An example of such a system is an integrated circuit having various interconnected circuit elements. Preferred embodiments of the present invention are thus described in the context of integrated circuits. But the present invention is applicable to the simulation of any system having interconnected elements when the simulation is carried out by solving system equations in matrix format and the elements in the system are represented in the system equations as matrix stamps. FIG. 1 illustrates a computer system (system) 100 that can be used to carry out the method according to one embodiment of the present invention. As shown in FIG. 1, the computer system (system) 100 includes a central processing unit (CPU) 102, and a disk memory 110 coupled to the CPU 102 through a bus 108. The system 100 further includes a set of input/output (I/O) devices 106, such as a keypad, a mouse, and a display device, also coupled to the CPU 102 through the bus 108. The system 100 may also include other devices 122, such as an input port for receiving data from a computer network or from a data collecting device (not shown). An example of system 100 is a Pentium 133 PC/Compatible computer having a RAM larger than 64 MB and a hard disk larger than 1 GB. Memory 110 has computer readable memory spaces such as memory space 112 that stores operating system 112 such as Windows 95/98/NT4.0/2000, which has instructions for communicating, processing, accessing, storing and searching data. Memory 110 further includes a database 114 that stores data and/or data structures used to carry out the circuit simulation program according to one embodiment of the present invention, and memory space 116 that stores program instructions (software) of a circuit simulation program 200 according to one embodiment of the present invention. Memory space 116 may be further subdivided as appropriate, for example to include memory portions 118 and 120 for storing modules and plug-in models, respectively, of the software. As shown in FIG. 2, in one embodiment of the present invention, the method for simulating an integrated circuit (or circuit) having various interconnected circuit elements is implemented in a circuit simulation program 200 having a model engine module (model engine) 210 and a solver module (solver) 230. The model engine 210 includes device models for modeling the circuit elements and is programmed to produce model results associated with a circuit element based on a set of terminal biases for the circuit element supplied by the solver 230. The solver 230 is programmed to form circuit equations in matrix format, to supply the set of terminal biases for each circuit element represented in the circuit equations to the model engine, to receive the model results produced by the model engine, to stamp the model results into designated entries in matrices associated with the circuit equations, to check for correctness of the model results by determining whether the model results interrelate according to a plurality of preset rules, and to solve the circuit equations to produce circuit simulation results. The circuit simulation program may also include a data input module 220 that arranges input data describing the circuit to be simulated in proper format or data structures, such as a netlist, for use by the solver, and a data output module 240 that arranges simulation results in proper format for display and use by circuit design engineers. FIG. 3 illustrates a process 300 performed by the solver 230 and the model engine 210 during the simulation of the integrated circuit. As shown in FIG. 3, in process 300, the solver 230 forms in step 301 the circuit equations according to an input netlist from the data input module 220. The circuit equations are formed in a matrix format and have at this point associated matrices with unfilled entries. Then, in order to form an initial operating point for the N-R solution of the circuit equations, the solver performs direct current (DC) simulation of the circuit in step 302. In DC simulation, AC sources are ignored, capacitors are replaced with open circuits and inductors with short circuits, and nonlinear devices are represented by their associated device models, and the simulator uses the Newton-Raphson algorithm to solve Kirchoffs Current Law at each node. The result of the DC simulation is a DC operating point of the circuit, which is selected in step 303 by the solver as the initial operating point. The initial operating point includes currents and node voltages in the circuit, from which the solver forms a set of terminal conditions such as terminal biases for a circuit element and supplies the set of terminal biases in step 304 to the model engine 210. The set of terminal biases may include information such as a terminal bias voltage between each terminal of the circuit element and the ground, or a terminal bias voltage between a reference terminal selected among the terminals of the circuit element and each of the other terminals of the circuit element. Thus, if the circuit element is a device having n terminals, the set of terminal biases may include {V1, . . . Vn}, where Vi represents the terminal bias voltage between terminal i and the ground or the terminal bias voltage between terminal i and a reference terminal such as terminal n (in this case Vn=0). Upon receiving the set of terminal biases, the model engine performs at step 306 model evaluation, and produces model results (or local variables) such as terminal currents, node charges, conductance and capacitance, etc., associated with the circuit element. The model results are communicated at step 308 to the solver. The solver then stamps the model results into designated entries in the matrices associated with the circuit equations in step 310. During the stamping in step 310, the model results or local variables are also arranged and stored as local variable matrices. For example, when the model results are for a circuit element with n terminals, the terminal currents or node charges are arranged as a local current vector I or local charge vector Q, respectively, I = [ I 1 ⋮ I n ] , or Q = [ Q 1 ⋮ Q n ] , where Ii represents the current entering terminal i, and qi represents the charge at terminal i, where i=1, . . . , n. Similarly, the conductance or capacitance associated with each pair of terminals of the circuit element is stores as a local conductance G or capacitance matrix C, respectively, G = ( G 11 ⋯ G 1 n ⋮ ⋰ ⋮ G n 1 ⋯ G nn ) , or C = ( C 11 ⋯ C 1 n ⋮ ⋰ ⋮ C n 1 ⋯ C nn ) , where Gij and Cij represents the conductance and capacitance, respectively, associated with terminals i and j, where j=1, . . . , n. The solver then checks at step 312 for correctness of the model results by determining whether the model results interrelate according to a plurality of preset rules. The step 312 may involve both the solver and the model engine in order to determine whether the model results interrelate according to some of the plurality of preset rules, as discussed below. If it is determined that the model results violate one or more of the plurality of preset rules in step 313, the solver prompts for a model error check, which is done at step 314 either manually or automatically using a separate computer program module. After checking for correctness of the model results, the solver proceeds to step 316 in which the solver determines if another circuit element also needs model evaluation. If the solver determines that there is a second circuit element for which a device model needs to be evaluated, the solver obtains the a set of terminal biases for the second circuit element based on the initial operating point and goes back to step 304 to provide the set of terminal biases associated with the second circuit element to the model engine, which then performs model evaluation for the second circuit element at step 306 and provides the model results for the second circuit element to the solver at step 308. The solver again stamps the model results into matrices in step 310 and checks the correctness of the model results for the second circuit element in step 312 to determine whether the results are interrelated according to the plurality of preset rules. If they are not, the solver again prompts for model error check. The solver then determines in step 316 if a third circuit element needs model evaluation. Steps 304 through 316 are thus repeated until the solver determines that no more circuit elements need model evaluation or the matrices associated with the circuit equations are filled. The solver then proceeds to obtain solutions of the states of the circuit by solving the circuit equations at step 318. In one embodiment of the present invention, the solutions of the circuit equations include currents and node voltages in the circuit. Steps 303 through 318 are iterated until the solver determines that a convergence has been reached in step 319. During the iteration, the solution of the circuit equations in each iteration round is used to form the operating point for the next iteration round in step 303, and a convergence is considered to have been reached in step 319 when the difference between the solutions of two consecutive iteration rounds are below some preset limits. When the convergence is reached, the solver outputs the simulation results at step 320. In one embodiment of the present invention, the plurality of the preset rules may include some or all of the following rules: 1. The sum of the entries in the current vector is zero; 2. The sum of the entries in the charge vector is zero; 3. The sum of the entries in each row of the conductance matrix is zero; 4. The sum of the entries in each column of the conductance matrix is zero; 5. The sum of the entries in each row of the capacitance matrix is zero; 6. The sum of the entries in each column of the capacitance matrix is zero; 7. Each diagonal entry in the conductance matrix is non-negative; 8. Each diagonal entry in the capacitance matrix is non-negative; 9. Each entry in the conductance matrix is the derivative of a corresponding entry in the terminal current vector with respect to a corresponding terminal bias voltage, i.e., G ij = ∂ I i ∂ V j ; 10. Each entry in the capacitance matrix is the derivative of a corresponding entry in the terminal charge vector with respect to a corresponding terminal bias voltage, i.e., C ij = ∂ Q i ∂ V j . Rule #1 and Rule #2 can be used to test if the terminal currents and node charges of all the nodes associated with the circuit element are conservative. Rule #3 through Rule #6 can be used to test if the conductance and capacitance associated with each pair of the terminals of the circuit element are calculated correctly. Rule #7 and Rule #8 can be used to test if there are any non-physical results, such as negative resistor or negative capacitor, in the model results. Rule #9 can be used to check the consistency between the conductance associated with any pair of terminals and the corresponding terminal current. Rule #10 can be used to check the consistency between the capacitance associated with any pair of terminals and the corresponding node charge. Rule #1 through #10 are applicable to any device model when an equivalent circuit associated with the device model includes only resistors, capacitors, and voltage-controlled current sources and when the circuit element being modeled by the device model has no external connections other than those through the terminals of the circuit element. Thus, Rule #1 through #10 are applicable to all of the compact models currently available for circuit simulation, such as the device models for active devices including MOSFETs, BJTs, JFETs, MESFETs, DIODEs, TFTs, and passive devices including resistors, capacitors, etc. FIG. 4 illustrates in further detail step 312 for checking the local variable matrices, such as I, Q, G, C, according to one embodiment of the present invention. As shown in FIG. 4, step 312 includes step 402 in which the local matrices are checked to see if they conform or substantially conform to some or all of Rule #1 through Rule #8, as stated above. When only substantial conformation is required, the sum of entries in the current vector, for example, does not have to be exactly zero to conform to Rule #1. When the sum of entries in the current vector is close to zero so that the difference between the sum of entries in the current vector and zero is within a predetermined limit, the local matrices are considered to substantially conform to Rule #1. The same is true for Rule #2 through #6 for substantial conformation. If Rule #9 and Rule #10 are to be checked, step 312 further includes steps 404, 406, 408, 410 and 412, which are performed for each terminal j, j=1, 2, . . . , n, of the circuit element. In step 404, terminal bias Vj corresponding to terminal j is changed slightly to Vj+ΔVj in the set of terminal biases and the changed set of terminal biases {V1, . . . , Vj+ΔVj, . . . , Vn}, where j=1, 2, . . . , n, is supplied to the model engine. Upon receiving the changed set of terminal biases, the model engine performs model evaluation in step 406 and produces model results based on the changed terminal biases to the solver. Upon receiving the model results in step 408, the solver arranges and stores the model results in step 410 as a new set of local variable matrices I′, Q′, G′, C′, and conformation with Rule 9 and/or Rule 10 are checked in step 512 by verifying that G ij = ∂ I i ∂ V j ≅ I i - I i ′ Δ V j , and / or C ij = ∂ Q i ∂ V j ≅ Q i - Q i ′ Δ V j . When ΔVj is small enough, Gij should exactly equal to I i - I i ′ Δ V j and Cij should exactly equal to Q i - Q i ′ Δ V j if there is no error with model evaluation. Again, in some applications, only substantial conformation with Rule #9 and Rule #10 are required, and Rule #9 and Rule #10 are considered being substantially conformed with when the difference between Gij and I i - I i ′ Δ V j and the difference between Cij and Q i - Q i ′ Δ V j are within predetermined limits. Thus, the present invention includes a self-contained method to insure the correctness of model stamping matrix without the need for golden data. The method is carried out during circuit simulation before circuit equations are solved. So, compared with prior art model QA techniques, which are standalone techniques performed after circuit simulation by comparing the simulation results with golden data, the present invention is more advantageous because it directly detects errors in model stamping matrix before solving the circuit equations. Also, without relying on golden data, the present invention provides a method to check for model evaluation errors over all applicable bias ranges. The method can also be used to check for inconsistency between terminal currents, node charges and their derivatives, i.e., conductance and capacitance, so that convergence problems associated with such inconsistencies can be avoided. To illustrate an application of the present invention, consider a gate resistance network in the BSIM4 model for modeling MOSFET devices, as shown in FIG. 5. The gate resistance network includes 5 nodes, Geltd, Gprime, G. intS, and intD, a resistor Rgeltd between node Geltd and node Gprime, a resistor Rii between node Gprime and node G, a capacitor Cgso between node Gprime and node intS, and a capacitor Cgdo between node Gprime and node intD. The charges associated with the capacitors Cgso and Cgdo should be calculated as in the following: Qgdo=Cgdo×(VGprime−Vint D), and Qgso=Cgso×(VGprime−Vint S), where Qgdo and Qgso are the charges associated with the capacitors Cgso and Cgdo, respectively, and VGprime, VintD, and VintS are the terminal bias voltages for nodes Gprime, intD, and intS, respectively. If Qgdo and Qgso are incorrectly calculated during model evaluation, such as in the following: Qgdo=Cgdo×(VG−Vint D), and Qgso=Cgso×(VG−Vint S), where VG is the terminal bias voltage for node G, the incorrect calculation would cause inconsistency between Qgdo and Cgdo and between Qdso and Cgso and thus convergence problems in N-R iteration. This inconsistency cannot be detected using conventional model QA techniques but can be easily discovered using the present invention because the model results would violate Rule #10, as stated above. | <SOH> BACKGROUND <EOH>The development of complicated physical systems often requires powerful numerical simulation programs. For example, circuit simulation is now an essential part in the design flow of integrated circuits. It helps circuit designers to verify the functionality and performance of their designs without going through expensive fabrication processes. Examples of electronic circuit simulators include the Simulation Program with Integrated Circuit Emphasis (SPICE) developed at the University of California, Berkeley (UC Berkeley), and various enhanced versions or derivatives of SPICE, such as, SPICE2 or SPICE3, also developed at UC Berkeley; HSPICE, developed by Meta-software and now owned by Synopsys; PSPICE, developed by Micro-Sim; and SPECTRE, developed by Cadence. The SPICE and its derivatives or enhanced versions will be referred to hereafter as SPICE circuit simulators, or SPICE. An electronic circuit is a network of circuit elements such as resistors, capacitors, inductors, mutual inductors, transmission lines, diodes, bipolar junction transistors (BJT), junction field effect transistors (JFET), metal-oxide-semiconductor field effect transistors (MOSFET), metal-semiconductor field effect transistors (MESFET), thin-film transistors (TFT), etc. SPICE usually handles a circuit in a node/element fashion, i.e., the circuit is regarded as a collection of various circuit elements connected at nodes. At the heart of SPICE is the so-called Nodal Analysis, which is accomplished by formulating nodal equations (or circuit equations) in matrix format to represent the circuit and solving the nodal equations. The circuit elements are modeled by device models, which produce model results that are represented in the circuit equations as matrix stamps. A device model for modeling a circuit element, such as the BSIM4 model for modeling MOSFET devices developed by UC Berkeley, typically includes model equations and a set of model parameters to mathematically represent characteristics of the circuit element under various bias conditions. For example, a circuit element with n terminals can be modeled by the following current-voltage relations: in-line-formulae description="In-line Formulae" end="lead"? I i =f i ( V 1 , . . . , V n , t ) for i= 1 , . . . , n, in-line-formulae description="In-line Formulae" end="tail"? where I i represents the current entering terminal i, V j (j=1 , . . . , n) represents the voltage or terminal bias across terminal j and a reference terminal, such as the ground, and t represents the time. The Kirchhoff's Current Law implies that the current entering terminal n is given by I n = ∑ i = 1 n - 1 I i . A conductance matrix of the circuit element is defined by: G ( V 1 , … , V n , t ) := ( ∂ f 1 ∂ V 1 ⋯ ∂ f 1 ∂ V n ⋮ ⋰ ⋮ ∂ f n ∂ V 1 ⋯ ∂ f n ∂ V n ) . To model the circuit element under alternating current (AC) operations, the device model also considers the relationship between node charges and the terminal biases: in-line-formulae description="In-line Formulae" end="lead"? □ Q i =q i ( V 1 , . . . , V n , t ) for i= 1 , . . . , n. in-line-formulae description="In-line Formulae" end="tail"? where Q i represents the represents the node charge at terminal i. Thus, the capacitance matrix of the n-terminal circuit element is defined by C ( V 1 , … , V n , t ) := ( ∂ q 1 ∂ V 1 ⋯ ∂ q 1 ∂ V n ⋮ ⋰ ⋮ ∂ q n ∂ V 1 ⋯ ∂ q n ∂ V n ) . For non-linear circuits, i.e., circuits including non-linear devices, SPICE often solves the circuit equations using the so-called Newton-Ralphson (N-R) iteration. To start the iteration process, SPICE selects an initial operating point for which the device model is evaluated. The initial operating point may include a set of terminal biases V j (j=1, . . . , n) associated with each of a plurality of circuit elements. Based on the set of terminal biases for each of the circuit elements, SPICE evaluates the device models for modeling the circuit elements and produces model results such as terminal currents, node charges and the derivatives of the terminal currents and node charges (conductance and capacitance) associated with the circuit elements. SPICE then stamps the terminal currents, node charges, and their derivatives into designated entries in the matrices of the circuit equations. The process of obtaining model results and stamping the model results into matrices are often referred to as model evaluation and model stamping or matrix stamping. SPICE then solves the circuit equations to produce circuit voltages and currents based on the initial operating point. The circuit voltages and currents based on the initial guess of the operating point are used to generate a second operating point, and SPICE then iterates the above process to solve the circuit equations based on the second operating point. The iteration continues until the differences in circuit voltages and currents from two consecutive iteration rounds have fallen below some predetermined limits, and the solution is considered to have converged. Thus, the correctness and the efficiency of circuit simulation depend on the correct implementation of the device models and correct stamping of the model results. For example, a basic requirement for the convergence of N-R iteration is the consistency between the terminal currents, node charges and their derivatives, which can be destroyed due to errors in the stamping of conductance or capacitance. As the technology advances and integrated circuits become more and more complex, it has become more and more difficult to guarantee the correct stamping of the model results. Usually, extensive model quality assurance (QA) procedures are followed after model evaluation to compare model results with golden data, which are obtained by measurements, by using a slower but more reliable simulation tool such as an electromagnetic field solver, or simply from a previous circuit simulation run. But this model QA method is disadvantageous because it depends on the quality of the golden data, which may be erroneous or simply unavailable, as in cases involving new technology and state-of-art device models. Even when the golden data are available and reliable, conventional model QA procedures are still insufficient because the golden data are typically obtained by DC sweep of bias voltages and because conventional model QA procedures often use DC solution of the model equations for comparison with the golden data. As a result, conventional model QA procedures cannot detect errors in matrix stamping of conductance or capacitance entries because these errors have no effect on the accuracy of DC solutions. The errors in matrix stamping of conductance or capacitance entries will, however, affect the convergence and speed of the circuit simulation and should be detected before they are used to solve the circuit equations. Furthermore, conventional model QA procedures are insufficient because they do not provide 100% bias coverage. The DC solution of the model equations and the comparison with golden data are usually performed for typical biases only. Moreover, conventional mode QA procedures do not test the consistency between currents, charges and their derivatives (conductance and capacitance), which is crucial for the convergence of N-R iteration. | <SOH> SUMMARY <EOH>The present invention includes a method for detecting model stamping errors during circuit simulation. In one embodiment of the present invention, the method is implemented in a circuit simulator for simulating an integrated circuit having various interconnected circuit elements. The circuit simulator includes a model engine module (model engine) and a solver module (solver). The model engine includes device models for modeling the circuit elements and is programmed to produce model results associated with a circuit element based on the set of terminal biases for the circuit element supplied by the solver. The solver is programmed to form circuit equations in matrix format, to supply the set of terminal biases for each of a plurality of circuit elements represented in the circuit equations to the model engine, to receive the model results produced by the model engine, to stamp the model results into designated entries in matrices associated with the circuit equations, to check for correctness of the stamped model results by determining whether the model results interrelate according to a plurality of preset rules, and to solve the circuit equations to produce circuit simulation results. | 20040206 | 20071120 | 20050811 | 63723.0 | 2 | GARBOWSKI, LEIGH M | MODEL STAMPING MATRIX CHECK TECHNIQUE IN CIRCUIT SIMULATOR | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,773,878 | ACCEPTED | Locking device having flange seal | A locking device includes a shackle member that includes an elongated shank portion, a stop portion on a first end and a latch portion on a second end. A locking head includes a locking mechanism that has an entryway to receive the latch portion and is movable between a locked state to retain the latch portion and a unlock state to release the latch portion. A head cover includes a cover portion that engages the locking head and a flange portion that extends inwardly to define an opening to receive the latch portion therethrough. A seal structure is associated with the inner edge of the flange and sealably engages the outer surface margin of the latch portion. The seal structure may be a margin of the flange portion or a separate O-ring. The lock may be constructed as a lockable hitch pin. | 1. A locking device, comprising: (A) a shackle member including (1) an elongated shank portion, (2) a stop portion at a first end of said shank portion, and (3) a latch portion at a second end of said shank portion, said shank portion having an outer surface margin adjacent to said latch portion; (B) a locking head including a locking mechanism disposed therein and having an entryway sized and adapted to mate with said latch portion, said locking mechanism being movable between (1) a locked state to lockably retain said latch portion in said locking head when said latch portion is in an engaged state and (2) an unlocked state to release said latch portion therefrom; and (C) a head cover including (1) a cover portion operative to engage said locking head, (2) a flange portion extending inwardly from said cover portion to define an opening having a surrounding flange edge, the opening being sized such that said latch portion may be inserted into and removed from said locking head through the opening, and (3) a seal structure associated with the edge of said flange, said seal structure operative when said latch portion is in the engaged state to sealably engage the outer surface margin of said shank portion. 2. A locking device according to claim 1 wherein said locking mechanism is key operable, said locking head having a face opposite the entryway with a keyway adapted to receive a key for said locking mechanism. 3. A locking device according to claim 2 wherein said head cover includes a cap member supported thereon, said cap member movable between an open position permitting access to the keyway and a closed position wherein said cap member prohibits access to the keyway. 4. A locking device according to claim 4 wherein said cap member is formed integrally with said cover member. 5. A locking device according to claim 1 wherein said locking head is formed either as a cylinder or a frustum with a surrounding outer head surface. 6. A locking device according to claim 5 wherein said cover portion is formed as a skirt extending around the outer head surface. 7. A locking device according to claim 1 wherein said head cover substantially encases said locking head. 8. A locking device according to claim 1 wherein said head cover is formed of a stiff yet resilient material, said seal structure being defined by an edge margin of said flange. 9. A locking device according to claim 8 wherein said edge margin has a truncated profile. 10. A locking device according to claim 1 wherein the edge of said flange has a groove formed therein, said seal structure being defined by a resilient seal member disposed in the groove. 11. A locking device according to claim 10 wherein said seal member is a resilient O-ring. 12. A locking device according to claim 1 wherein said shank is an elongated linear member and extends along a central longitudinal axis. 13. A locking device according to claim 12 wherein said shank has a cylindrical configuration. 14. A locking device according to claim 12 wherein said locking head and said stop member are aligned with said shank along said longitudinal axis. 15. A locking device according to claim 1 wherein said stop portion is formed either as a cylinder or a frustum. 16. A locking device according to claim 1 including a stop portion cover that substantially encases said stop portion. 17. A locking device according to claim 16 wherein said stop portion cover is formed of a stiff yet resilient material. 18. A locking hitch pin adapted to secure at least two members together, comprising: (A) a shackle member including (1) an elongated cylindrical shank portion, (2) a stop portion located at a first end of said shank portion and formed as either a cylinder or a frustum and oriented coaxially with said shank portion so as to have a peripheral stop portion surface, a transversely oriented inner stop face adjacent to said shank portion and a transversely oriented outer stop face opposite said inner stop face, and (3) a latch portion at a second end of said shank portion, said shank portion having an outer surface margin adjacent to said latch poriton; (B) a locking head formed either as a cylinder or a frustum adapted to engage said shank to define an engaged state, said locking head having a peripheral head surface, a transversely oriented inner head face adjacent to said shank portion with an entryway sized and adapted to mate with said latch portion such that said locking head is coaxial with said shank when in the engaged state and a transversely oriented outer head face opposite said inner head face, said locking head including a locking mechanism disposed therein that is movable between (1) a locked state to lockably retain said latch portion in said locking head when said latch portion is in the engaged state with said locking head and (2) an unlocked state to release said latch portion from said locking mechanism; and (C) a head cover including (1) a skirt operative to extend around at least some of the peripheral head surface so as to engage said locking head, (2) a flange extending inwardly from said skirt portion alongside the inner head face and having an opening forming a surrounding flange edge, the opening being sized such that said latch portion may be inserted into and removed from said locking head through the opening, and (3) a seal structure associated with the edge of said flange, said seal structure operative when said latch portion is in the engaged state to seal against the outer surface margin of said shank portion. 19. A locking hitch pin according to claim 18 wherein said locking mechanism is key operable, said outer head face provided with a keyway adapted to receive a key for said locking mechanism. 20. A locking hitch pin according to claim 19 wherein said head cover includes a cap member supported thereon, said cap member movable between an open position permitting access to the keyway and a closed position wherein said cap member engages said locking head to prohibit access to the keyway. 21. A locking hitch pin according to claim 18 wherein said head cover substantially encases said locking head. 22. A locking hitch pin according to claim 18 wherein said head cover is formed of a stiff yet resilient material, said seal structure being defined by an edge margin of said flange. 23. A locking hitch pin according to claim 22 wherein said edge margin has a truncated profile. 24. A locking hitch pin according to claim 18 wherein the edge of said flange has a groove formed therein, said seal structure being defined by a resilient seal member disposed in the groove. 25. A locking hitch pin according to claim 24 wherein said seal member is a resilient O-ring. 26. A locking hitch pin according to claim 18 including a stop portion cover having a skirt operative to extend around at least some of the peripheral stop portion surface so as to engage said stop portion. 27. A locking hitch pin according to claim 18 wherein said stop portion cover has a second flange extending radially inwardly from said skirt alongside the inner stop face. 28. A locking hitch pin according to claim 27 wherein said stop portion cover substantially encases said stop portion. 29. A locking device according to claim 28 wherein said stop portion cover and said head cover are formed of a stiff yet resilient material such that said first and second flanges form bumpers, respectively for said locking head and said stop portion relative to the two members to be secured together thereby. 30. In a hitch adapted to interconnect a trailer vehicle to a towing vehicle including a hitch bar having a passageway therethrough and a hitch receiver having opposed holes, said hitch bar and said hitch receiver operative to telescopically mate together as a mated pair with the passageway aligned with the holes to define a transverse dimension for said mated pair, the improvement comprising a hitch pin assembly including a shackle member that has an elongated shank portion with a stop portion at a first end thereof and a latch portion at a second end thereof, said shank portion having an outer surface adjacent to said latch portion, said hitch pin assembly further including a locking head that has a locking mechanism disposed therein and that has an entryway sized and adapted to mate with said latch portion with the locking mechanism being movable between a locked state to lockably retain said latch portion therein when said latch portion is in an engaged state with said locking head and an unlocked state to release said latch portion therefrom, said hitch pin assembly further including a head cover that has a first cover portion operative to engage said locking head, a flange portion extending inwardly from said cover portion to define an opening having a surrounding flange edge with the opening being sized such that said latch portion may be inserted and removed from said locking head through the opening, and a seal structure associated with the edge of said flange, said seal structure operative when said latch portion is in the engaged state to sealably engage the outer surface of said shank portion. 31. The improvement according to claim 30 wherein said head cover substantially encases said locking head. 32. The improvement according to claim 30 wherein said head cover is formed of a stiff yet resilient material, said seal structure being defined by an edge margin of said flange. 33. The improvement according to claim 30 wherein the edge of said flange has a groove formed therein, said seal structure being defined by a resilient seal member disposed in the groove. 34. The improvement according to claim 30 including a stop portion cover that substantially encases said stop portion. 35. The improvement according to claim 30 wherein said stop portion cover is formed of a stiff yet resilient material. | FIELD OF THE INVENTION The present invention broadly relates to locking devices that are adapted to secure objects together. More particularly, the present invention concerns key operable locking devices, such as hitch pins and the like. The present invention specifically concerns a locking device that provides a flange seal between the locking head and the shank of a shackle. BACKGROUND OF THE INVENTION Over the years, there have been numerous variations of locking devices from a multiple of applications. Typically, a locking device is used to secure two or more objects or members together, whether those items be independent items, a door for an enclosure, or otherwise. Moreover, a wide variety of locking mechanisms have been employed, including key actuated locks and combination locks, all of various constructions. A widely used locking device is known as a padlock. The prior art padlock works adequately for a number of conventional applications wherein the span of objects to be secured is relatively short or where the span can be fitted with a hasp. However, numerous shortcomings of padlocks become apparent when a padlock is sought to be used in applications wherein two objects of thick cross-sections are to be secured. Examples of such conventional applications include those where telescopically joined round or square tubing members need to be secured together. Another example is where perpendicular or axially cross bolting of gates and doors require a substantially rod-like locking device. As a result of the need for rod or elongated shackle locking devices, various devices have been developed to penetrate multiple surfaces having aligned through bores for the purpose of securing those objects together. Once such example is found in U.S. Pat. No. 2,677,261 issued May 1954 to Jacobi. The Jacobi patent, a complex locking device is taught in order to prevent actuation of a refrigerator door handle. Another example of a rod-locking device is found in U.S. Pat. No. 4,576,021 issued Mar. 18, 1986 to Holden. Holden discloses a locking rod device having a rectangular locking head that is somewhat bulky and non-symmetrical. In the Holden locking device, a radially extendable locking pin engages a circumferential opening in the latch portion of the shackle in order to retain the shackle and locking head together. The bulky nature of this lock head design, however, makes it disadvantageous in use where only limited space is available. In addition, where the locking pin is spring loaded, the locking structure of Holden is prone to false locking, that is, the engagement of the locking head and shackle without an actual locked state occurring. Thus, the locking head may fall off during use. Several additional types of straight shackle locks have been developed wherein the latched portion of the shackle is threadably received in a screw-type lock. Examples of these locks are described in U.S. Pat. No. 4,619,122 issued Oct. 28, 1986 to Simpson as well as in U.S. Pat. No. 4,711,106 issued Dec. 8, 1987 to Johnson. These types of locks, however, tend to be inconvenient and cumbersome to use due to the threaded nature of their locked mechanisms. Specifically, the key actuable locking head described in these two patents require a large number of key rotations in order to thread and fully secure the locking head portion onto the straight shackle. The inconvenience and difficulty of threaded lock systems is compounded when the lock is located in tight or difficult to access areas. Further, the threaded screw locks are especially prone to corrosion and seizure due to the small dimensioning of the threads. The majority of the locking structures described in the prior art fail to employ suitable seals or other structures, such as caps or protective devices to limit access of unwanted substances such as dirt and moisture into the keyway or into the locking region. In U.S. Pat. No. 5,664,445 issued Sep. 9, 1997 to Chang, a sealing ring is provided on the shackle latch portion. While the Chang patent does address the importance of limiting the access of dirt and moisture into the locked mechanism, the solution offered in the Chang patent has some drawbacks. Due to the location of the seal on the end portion of the shackle, the seal is completely exposed. Since it is of larger diameter than the shank of the shackle, the slidable engagement of the shackle through aligned bores of two objects exposes the oversized diameter of the seal to attack by the rough edges or other sharp corners of the bores due to its oversized diameter. Thus, the seal can become damaged due to the snagging or rubbing of the seal against the aligned holes. An improvement to these structures is described in my U.S. Pat. No. 6,055,832 issued May 2, 2000. In this patent, a locking device includes a shackle member and a key operable locking head that may be fastened onto a latch portion of the shackle member. The locking head has a housing and a rotatable retainer and a lock core in the interior of the housing. The lock core is mechanically coupled to the retainer, and both the retainer and the lock core are axially oriented with respect to an axial opening in the housing. The latch portion is axially insertable through the axial opening when the lock core is in an unlocked state and has a latch head which becomes fastened by the locking head when the retainer is rotated by the lock core into a locked state. A seal is supported by the housing proximately to the axial opening and acts seal against a seal surface on the latch portion. Despite the improvements described above in the various types of locking devices noted, there remains a need for an improved locking device having a simplified seal at an interface between the locking head and the shackle portion. There is a need for such a seal that can be conveniently manufactured with reduced costs of assembly. There is further a need for such locking devices that provide a seal in an aesthetically pleasing manner. There is a further need for such locking devices that provide a bumper-like construction so as to cushion members locked thereby. The present invention is directed to meeting such needs. SUMMARY OF THE INVENTION It is an object of the present invention to provide a new and useful locking device that is simple in construction and yet which provides a convenient seal between a locking head and the shackle. It is another object of the present invention to provide a locking device that is particularly useful as a locking pin, such as a hitch pin and the like. Still a further object of the present invention is to provide a locking device which is aesthetically pleasing yet which provides a convenient and simple seal to help insulate the locking mechanism against intrusion of foreign substances while in use. Still a further object of the present invention is to provide an old-type locking structure having a pleasing, symmetrical appearance. According to the present invention, then, a locking device is provided with this locking device described to be a locking hitch pin such as that used to interconnect a hitch bar to a hitch received such as would be used to interconnect a trailer vehicle to a towing vehicle. Broadly, the locking device includes a shackle member that has an elongated shank portion, a stop portion at a first end of the shank portion and a latch portion at a second end of the shank portion such that the shank portion has an outer surface margin adjacent to the latch portion. A locking head has an entryway sized and adapted to mate with the latch portion and includes a locking mechanism that is moveable between a locked state to lockably retain the latch portion therein when the latch portion is in an engaged state with the locking head at an unlocked state the release the latch portion therefrom. A head cover is provided that includes a cover portion operative to engage the locking head and a flange extending inwardly from the covered portion to define an opening having a surrounding flange edge. This opening is sized such that latch portion may be inserted into and removed from the locking head through the opening. A seal structure is associated with the edge of the flange, and the seal structure is operative when the latch portion is in the engage state to releasably engage the outer surface margin of the shank portion. The locking mechanism is illustrated to be key operable, but other locking mechanisms, such as combination locks, are contemplated. Where the locking mechanism is key operable, the locking head has a face opposite the entryway, and a key way is provided in that face with the key way being operative to receive the key for the locking mechanism. Here, the head cover can include a cap member supported thereon, such as by a hinge piece. The cap member is moveable between an open position permitting access to the key way and a closed position wherein the cap member prohibits access to they key way. Here, the cap member can be formed integrally with the cover member. The locking head can be formed either as a cylinder or as a frustum having a transverse inner head face, a transverse outer head face and a peripheral head surface. The cover portion of the head cover can be formed as a skirt extending around the outer head surface of the locking head. The flange then extends alongside the inner of the locking head, and the head cover can substantially encase the locking head. In one embodiment, the head cover is formed of a stiff yet resilient material. Here, the seal structure is defined by an edge margin of the flange. This edge margin can have a truncated profile. In an alternative embodiment, the edge to the flange can have a groove formed therein, and the seal structure is defined by a resilient seal member, such as an o-ring, disposed in the groove. The shank of the shackle member may be of an elongated cylindrical configuration that extends along a central longitudinal axis. The stop portion can be formed either as a cylinder or as a frustum having a transverse inner stop face, a transverse outer stop face and a peripheral stop surface. When in the locked state, the locking head and the stop member are aligned with the shank along the central longitudinal axis. If desired, a stop portion cover may also be provided according to the present invention. Here, the stop portion cover may substantially encase the stop portion. This stop portion cover may be formed of a stiff yet resilient material. If desired, the stop portion may have a radially inwardly projecting flange, that may be formed by an annular washer that snap locks onto this stop cover portion. This flange then extends alongside the inner stop face and, along with the flange of the head cove, can provide a resilient bumper to help reduce rattling of a hitch pin when used with a hitch bar and hitch receiver. To this end, the present invention contemplates an improvement to a hitch that is adapted to interconnect a trailer vehicle to a towing vehicle wherein the hitch includes a hitch bar having a passageway therethrough, such as formed by opposed holes, and a hitch receiver having opposed holes. The hitch bar and hitch receiver are operative to telescopically mate together as a mated pair with the passageway of the hitch bar being aligned with the holes of the hitch receiver with the width of the hitch receiver defining a transverse dimension for the mated pair. The improvement comprises a hitch pin assembly such as that described above and in greater detail below. These and other objects of the present invention will become more readily appreciated and understood from a consideration of the following detailed description of the exemplary embodiments of the present invention when taken together with the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a locking device according to a first exemplary embodiment of the present invention; FIG. 2 is a side view in elevation, partially broken away, of the shackle member according to the exemplary embodiment of the present invention illustrated in FIG. 1; FIG. 3 is a top plan view of the shackle member of FIG. 2; FIG. 4 is an exploded perspective view of the shackle member of FIG. 1 illustrated with a key for actuating the locking mechanism thereof; FIG. 5 is a side view in cross-section illustrating the stop portion cover introduced in FIG. 4; FIG. 6 is an exploded perspective view of the locking head construction introduced in FIG. 4; FIG. 7 is a side view in cross-section of the locking head cover illustrated in FIG. 6; FIG. 9 is a side view in partial cross-section illustrating the locking head of the first exemplary embodiment of the present invention engaging an end portion of the shackle shank so as to illustrate the seal between the locking head and the shank and with the protective cap in open position; FIG. 10 is a side view in partial cross-section, similar to FIG. 9, but showing the cap member in a closed position; FIG. 11 is a side view in cross-section, similar to FIG. 7, but illustrating a second embodiment of the present invention utilizing an alternative seal structure; FIG. 12 is a side view in partial cross-section showing an alternative embodiment of the stop portion cover according to the present invention; and FIG. 13 is and end view in partial cross-section showing the present invention securing a hitch bar to a hitch receiver. DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS The present invention is broadly directed to a locking device that is adapted to secure objects together. This device is particularly constructed so as to provide a seal between the locking head and a shank portion of the shackle. While the present invention may be employed with a variety of locking devices, it particularly concerns a locking device in the form of a pin type-locking device that is used to secure two objects together and is specifically depicted as a hitch pin that may be used to secure a hitch receiver to a hitch bar as is the common practice in towing applications. Moreover, while the present invention is described with respect to a key operable locking device, it should be understood that the invention is not limited to key operable locking devices, but the inventive concepts herein may be employed with combination-type locking mechanisms. For illustrative purposes, the present invention is described for a locking device employing a locking mechanism such as that described in my U.S. Pat. No. 6,055,832, the disclosure of which is incorporated herein by reference. However, the present invention departs from that invention by providing a different sealing arrangement between the locking head and the shank portion of the shackle member and by providing a stop portion cover, as is hereinafter described in greater detail. With initial reference to FIG. 1, then, a locking device 10 is depicted which includes a shackle member 12 and a locking head 14 secured to shackle member 12 to define a fastened state. Shackle member 12 may be formed of any suitable material, although for strength, shackle member 12 may be formed of hardened steel, stainless steel, and the like, and includes a stop portion 22 at a second end opposite locking head 14. In an assembled state, as is shown again in FIG. 1, it may be seen that locking head 40, stop member 22 are aligned with shank portion 20 along the longitudinal axis “L”. Shackle member 12 is shown in greater detail in FIGS. 2-4. Here, shackle member 12 includes an elongated cylindrical shank 20 that has a central longitudinal axis “L”. While shank portion 20 is illustrated to be cylindrical in configuration, other cross-sections are contemplated within the scope of this invention. In any event, a stop portion 22 is located at a first end of shank portion 20, and a latch portion 24 is located at a second end of shank portion 20 opposite stop portion 22. Shank portion 20 has an outer surface margin 26 adjacent to latch portion 24. Thus, margin 26 extends circumferentially around the end of shank portion 20 adjacent to latch portion 24. Stop portion 22 is illustrated to be formed as a cylindrical member, but could well be formed as a frustoconical member as illustrated in my U.S. Pat. No. 6,055,832. Thus, stop portion 22 has a peripheral stop portion surface 23, a transversely extending outer stop face 25 and a transversely extending inner stop face 27. The construction of latch portion 22 is also the same as that described in my U.S. Pat. No. 6,055,832. Here, latch portion 24 includes latch head 28 with oppositely projecting radial lobes 30 and is supported by means of a cylindrical post 32. Latch head 28 thus defines a locking profile for mating with a locking head 40, as described more thoroughly below. With continued reference to FIGS. 2-5, a stop portion cover 34 is sized for close-fitted mated engagement with stop portion 20 so that it substantially encases stop portion 22, as illustrated in FIGS. 2 and 3. Stop portion cover 34 includes an end wall 36 and a cylindrical surrounding side wall 37 that encloses an interior 38 which mates with stop portion 22. An edge of sidewall 37 opposite end wall 36 is provided with an inwardly projecting lip 39 in order to retain stop portion cover 34 on stop portion 22. To this end, it should be appreciated that stop portion cover 34 is formed of a stiff yet resilient material, such as plastic, rubber and the like. Stop portion cover 34 may be manufactured in any suitable manner, such as by injection molding. As noted, latch portion 24 is adapted to engage a locking head 40. As is shown in reference to FIGS. 4 and 6, locking head 40 includes a key actuable lock mechanism 42 that can be moved between a locked state and an unlocked state. The structure of locking head 40 is again the same as that described in my U.S. Pat. No. 6,055,832, the disclosure of which has been incorporated herein by reference, but it should be understood that other locking mechanisms could be employed as well. In any event, locking mechanism 42 includes a housing 44 having a cylindrical interior and an axial opening 46 of generally rectangular cross-section sized that forms an entryway for latch portion 24. Thus, locking head 40 can receive latch portion 26 to define an engaged state. A lock core 48 may be received in the interior of housing 44 and held in position by means of a pin 50 through bore 52. Lock core 48 is key operable and is of standard construction as is known in the art so as to be actuated by a key, such as tubular key 54. Thus, locking head 40 has a peripheral head surface 41 and a transverse outer head face 56 that is opposite axial opening 46 in inner transverse head face 47, and face 56 has a keyway 58 sized for insertion of key 54 therein so that lock core 48 may be rotated relative to housing 44. Lock core 48 includes a drive cog 60 operative to mechanically couple to a retainer 62. Accordingly, rotation of lock core 48 causes retainer 62 to move between a locked and unlocked state. Retainer 62 may have a two-piece construction, including a sleeve 64 and a C-shaped washer 66 sleeve 64 includes a prong 68. C-shaped washer 66 seats on sleeve 64 with prong 68 engaging a slot 70 between arms 72 of C-shaped washer 66. Thus, rotation of lock core 48 rotates sleeve 64 which in turn rotates C-shaped washer 66 so as to lockably retain latch portion 24 in locking head 40 when latch portion 24 is engaged therewith. As is illustrated in FIGS. 4 and 6, locking head 40 is cylindrical in shape, but again with reference to U.S. Pat. No. 6,055,832 may be frustoconical as well. In any event, a head cover is provided for close fitted engagement with locking head 40. This head cover 80 being best illustrated in FIGS. 4, 6 and 7. Here, it may be seen that head cover 80 includes a cover portion that is operative engage a locking head. Head cover 80 may be manufactured in any suitable manner, such as by injection molding. In this embodiment, the first cover portion is in the form of a cylindrical skirt 82 that substantially encases locking head 40, although it should be appreciated that it is not essential for this invention for skirt 82 to encase locking head 40, but rather it is only necessary that head cover 80 engage locking head 40 sufficiently to be retained thereon. A flange portion 84 extends inwardly from cover portion or skirt 82 to define an opening 86 having a surrounding flange edge 88. With brief reference to FIG. 8, it may be seen that flange edge 88 is truncated in cross-section. Thus, flange edge 88 has a trapezoidal cross-section. Head cover 80 includes an interior 90 that is sized for close fitted engagement with latch head 40 with opening 86 being sized such that latch portion 24 of shackle member 12 may be inserted into and removed from locking head 40. Head cover 80 also includes a cap member 92 that is pivotally attached to skirt 82 by means of a flexible hinge 94. Head cover 80 including cap 92 and hinge 94 may be of an integral one-piece construction, such as molded plastic and the like. With reference to FIGS. 9 and 10, it may be seen that locking head 40 is received in head cover 80 with latch head 28 being in an engaged state therewith so that outer surface margin 26 of shank portion 20 is adjacent locking head 40. In FIG. 8, cap member 92 is in an open position, but may be moved to a closed position, as is shown in FIG. 9 wherein cap portion 92 snap locks onto a ridge 96 formed at an edge of skirt 82. With continued reference to FIGS. 7-10, it should be appreciated that flange edge 88 in this embodiment defines a seal structure which is enhanced by its truncated cross-section. The seal structure formed by flange edge 88 is operative when latch portion 24 is in the engaged state the sealably engage the outer surface margin 26 of shank portion 20. This sealing engagement reduces the likelihood of the ingress of water and other contaminant into the lock mechanism of locking head 40. Further, cap member 92 reduces the likelihood of contamination from water, dust or other materials through keyway 58. Since head cover 80 is formed of a stiff yet resilient material, this sealing arrangement is enhanced. It should be understood, though, that the term “sealing” need not mean an absolute seal but only that which is sufficient to reasonably protect the locking mechanism of locking head 40. An alternative construction for head cover 80 is illustrated in FIG. 11. Here, head cover 180 includes a skirt 182 a cap member 192 and hinge 194 and an opening 186, all similar to that described with respect to head cover 80. Here, however, head cover 180 includes a flange 184 that has a flange edge 188 provided with a groove 189 extending therearound. Groove 189 is sized and adapted to engage a resilient seal in the form of an o-ring 191. In use, head cover 180 is identical to that described with respect to head cover 80. Here, however, o-ring 191 seals against the outer surface margin 26 of shank portion 20. A modification to stop cover 34 is illustrated in FIG. 12. Here, stop cover 134 includes an end wall 136 a surrounding sidewall 137. An annular washer 135 snap locks onto the edge 143 of sidewall 137 opposite end wall 136. This allows stop portion 22 to be nested in the interior of stop cover 134 after which washer 135 is placed around shank portion 20 and advanced into engagement with edge 143. Annular washer 135 defines a flange 139 that projects radially inwardly a greater distance than lip 39 described with respect to stop cover 35. The inner edge 141 of the opening in annular washer 135 is therefore circumjacent the cylindrical sidewall of shank portion 20. Annular washer 139 thus forms a bumper which along with the bumper formed by either flange portion 84 or 184 of head cover 80 or 180, respectively, acts to cushion objects secured thereby on shank portion 20. Such objects, as is contemplated by this invention, can be a hitch that is adapted to interconnect a trailer vehicle to a towing vehicle. In such a hitch, a hitch bar is provided that has a passageway therethrough and a hitch receiver is provided that has opposed holes, as is known in the art. This is illustrated in FIG. 13. Here, the hitch bar 200 and the hitch receiver 202 telescopically mate together as a mated pair with the passageway formed by holes 204 in hitch bar 200 aligned with the holes 206 in hitch receiver 202. The width of hitch receiver 202 thus defines a transverse dimension for the mated pair. The present invention provides an improvement to such a hitch assembly by incorporating a hitch pin assembly that includes a shackle member, as described above. When the hitch pin locking device as above described is used to secure the hitch bar 200 to the hitch receiver 202, flange portions 84 and 139 act to cushion the movement of the hitch pin relative to the hitch bar and hitch receiver. Due to the resilient construction of head cover 80,180 and stop portion cover 134, a dampening action is provided which tends to reduce rattling of the hitch pin. Accordingly, the present invention has been described with some degree of particularity directed to the exemplary embodiments of the present invention. It should be appreciated, though, that the present invention is defined by the following claims construed in light of the prior art so that modifications or changes may be made to the exemplary embodiments of the present invention without departing from the inventive concepts contained herein. | <SOH> BACKGROUND OF THE INVENTION <EOH>Over the years, there have been numerous variations of locking devices from a multiple of applications. Typically, a locking device is used to secure two or more objects or members together, whether those items be independent items, a door for an enclosure, or otherwise. Moreover, a wide variety of locking mechanisms have been employed, including key actuated locks and combination locks, all of various constructions. A widely used locking device is known as a padlock. The prior art padlock works adequately for a number of conventional applications wherein the span of objects to be secured is relatively short or where the span can be fitted with a hasp. However, numerous shortcomings of padlocks become apparent when a padlock is sought to be used in applications wherein two objects of thick cross-sections are to be secured. Examples of such conventional applications include those where telescopically joined round or square tubing members need to be secured together. Another example is where perpendicular or axially cross bolting of gates and doors require a substantially rod-like locking device. As a result of the need for rod or elongated shackle locking devices, various devices have been developed to penetrate multiple surfaces having aligned through bores for the purpose of securing those objects together. Once such example is found in U.S. Pat. No. 2,677,261 issued May 1954 to Jacobi. The Jacobi patent, a complex locking device is taught in order to prevent actuation of a refrigerator door handle. Another example of a rod-locking device is found in U.S. Pat. No. 4,576,021 issued Mar. 18, 1986 to Holden. Holden discloses a locking rod device having a rectangular locking head that is somewhat bulky and non-symmetrical. In the Holden locking device, a radially extendable locking pin engages a circumferential opening in the latch portion of the shackle in order to retain the shackle and locking head together. The bulky nature of this lock head design, however, makes it disadvantageous in use where only limited space is available. In addition, where the locking pin is spring loaded, the locking structure of Holden is prone to false locking, that is, the engagement of the locking head and shackle without an actual locked state occurring. Thus, the locking head may fall off during use. Several additional types of straight shackle locks have been developed wherein the latched portion of the shackle is threadably received in a screw-type lock. Examples of these locks are described in U.S. Pat. No. 4,619,122 issued Oct. 28, 1986 to Simpson as well as in U.S. Pat. No. 4,711,106 issued Dec. 8, 1987 to Johnson. These types of locks, however, tend to be inconvenient and cumbersome to use due to the threaded nature of their locked mechanisms. Specifically, the key actuable locking head described in these two patents require a large number of key rotations in order to thread and fully secure the locking head portion onto the straight shackle. The inconvenience and difficulty of threaded lock systems is compounded when the lock is located in tight or difficult to access areas. Further, the threaded screw locks are especially prone to corrosion and seizure due to the small dimensioning of the threads. The majority of the locking structures described in the prior art fail to employ suitable seals or other structures, such as caps or protective devices to limit access of unwanted substances such as dirt and moisture into the keyway or into the locking region. In U.S. Pat. No. 5,664,445 issued Sep. 9, 1997 to Chang, a sealing ring is provided on the shackle latch portion. While the Chang patent does address the importance of limiting the access of dirt and moisture into the locked mechanism, the solution offered in the Chang patent has some drawbacks. Due to the location of the seal on the end portion of the shackle, the seal is completely exposed. Since it is of larger diameter than the shank of the shackle, the slidable engagement of the shackle through aligned bores of two objects exposes the oversized diameter of the seal to attack by the rough edges or other sharp corners of the bores due to its oversized diameter. Thus, the seal can become damaged due to the snagging or rubbing of the seal against the aligned holes. An improvement to these structures is described in my U.S. Pat. No. 6,055,832 issued May 2, 2000. In this patent, a locking device includes a shackle member and a key operable locking head that may be fastened onto a latch portion of the shackle member. The locking head has a housing and a rotatable retainer and a lock core in the interior of the housing. The lock core is mechanically coupled to the retainer, and both the retainer and the lock core are axially oriented with respect to an axial opening in the housing. The latch portion is axially insertable through the axial opening when the lock core is in an unlocked state and has a latch head which becomes fastened by the locking head when the retainer is rotated by the lock core into a locked state. A seal is supported by the housing proximately to the axial opening and acts seal against a seal surface on the latch portion. Despite the improvements described above in the various types of locking devices noted, there remains a need for an improved locking device having a simplified seal at an interface between the locking head and the shackle portion. There is a need for such a seal that can be conveniently manufactured with reduced costs of assembly. There is further a need for such locking devices that provide a seal in an aesthetically pleasing manner. There is a further need for such locking devices that provide a bumper-like construction so as to cushion members locked thereby. The present invention is directed to meeting such needs. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide a new and useful locking device that is simple in construction and yet which provides a convenient seal between a locking head and the shackle. It is another object of the present invention to provide a locking device that is particularly useful as a locking pin, such as a hitch pin and the like. Still a further object of the present invention is to provide a locking device which is aesthetically pleasing yet which provides a convenient and simple seal to help insulate the locking mechanism against intrusion of foreign substances while in use. Still a further object of the present invention is to provide an old-type locking structure having a pleasing, symmetrical appearance. According to the present invention, then, a locking device is provided with this locking device described to be a locking hitch pin such as that used to interconnect a hitch bar to a hitch received such as would be used to interconnect a trailer vehicle to a towing vehicle. Broadly, the locking device includes a shackle member that has an elongated shank portion, a stop portion at a first end of the shank portion and a latch portion at a second end of the shank portion such that the shank portion has an outer surface margin adjacent to the latch portion. A locking head has an entryway sized and adapted to mate with the latch portion and includes a locking mechanism that is moveable between a locked state to lockably retain the latch portion therein when the latch portion is in an engaged state with the locking head at an unlocked state the release the latch portion therefrom. A head cover is provided that includes a cover portion operative to engage the locking head and a flange extending inwardly from the covered portion to define an opening having a surrounding flange edge. This opening is sized such that latch portion may be inserted into and removed from the locking head through the opening. A seal structure is associated with the edge of the flange, and the seal structure is operative when the latch portion is in the engage state to releasably engage the outer surface margin of the shank portion. The locking mechanism is illustrated to be key operable, but other locking mechanisms, such as combination locks, are contemplated. Where the locking mechanism is key operable, the locking head has a face opposite the entryway, and a key way is provided in that face with the key way being operative to receive the key for the locking mechanism. Here, the head cover can include a cap member supported thereon, such as by a hinge piece. The cap member is moveable between an open position permitting access to the key way and a closed position wherein the cap member prohibits access to they key way. Here, the cap member can be formed integrally with the cover member. The locking head can be formed either as a cylinder or as a frustum having a transverse inner head face, a transverse outer head face and a peripheral head surface. The cover portion of the head cover can be formed as a skirt extending around the outer head surface of the locking head. The flange then extends alongside the inner of the locking head, and the head cover can substantially encase the locking head. In one embodiment, the head cover is formed of a stiff yet resilient material. Here, the seal structure is defined by an edge margin of the flange. This edge margin can have a truncated profile. In an alternative embodiment, the edge to the flange can have a groove formed therein, and the seal structure is defined by a resilient seal member, such as an o-ring, disposed in the groove. The shank of the shackle member may be of an elongated cylindrical configuration that extends along a central longitudinal axis. The stop portion can be formed either as a cylinder or as a frustum having a transverse inner stop face, a transverse outer stop face and a peripheral stop surface. When in the locked state, the locking head and the stop member are aligned with the shank along the central longitudinal axis. If desired, a stop portion cover may also be provided according to the present invention. Here, the stop portion cover may substantially encase the stop portion. This stop portion cover may be formed of a stiff yet resilient material. If desired, the stop portion may have a radially inwardly projecting flange, that may be formed by an annular washer that snap locks onto this stop cover portion. This flange then extends alongside the inner stop face and, along with the flange of the head cove, can provide a resilient bumper to help reduce rattling of a hitch pin when used with a hitch bar and hitch receiver. To this end, the present invention contemplates an improvement to a hitch that is adapted to interconnect a trailer vehicle to a towing vehicle wherein the hitch includes a hitch bar having a passageway therethrough, such as formed by opposed holes, and a hitch receiver having opposed holes. The hitch bar and hitch receiver are operative to telescopically mate together as a mated pair with the passageway of the hitch bar being aligned with the holes of the hitch receiver with the width of the hitch receiver defining a transverse dimension for the mated pair. The improvement comprises a hitch pin assembly such as that described above and in greater detail below. These and other objects of the present invention will become more readily appreciated and understood from a consideration of the following detailed description of the exemplary embodiments of the present invention when taken together with the accompanying drawings, in which: | 20040205 | 20070605 | 20050106 | 78406.0 | 1 | GALL, LLOYD A | LOCKING DEVICE HAVING FLANGE SEAL | SMALL | 0 | ACCEPTED | 2,004 |
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10,773,906 | ACCEPTED | Multi-layer core golf ball | The present invention is directed to an improved golf ball displaying the desired spin profile and having a generally rigid, thermoset polybutadiene outer core surrounding a relatively soft, low compression inner core. In general, this golf ball has an inner core and at least one outer core layer surrounding the inner core. The inner core has a hardness less than a hardness of the outer core and a specific gravity less than or equal to the outer core specific gravity. Overall the inner core compression and outer core are formulated to provide a combined overall core compression of greater than about 50, preferably greater than about 70. A cover layer is provided to surround and to cover the outer core layer. A moisture barrier layer is provided between the outer core layer and the cover layer to protect the inner and outer cores from degradation due to exposure to water. The moisture vapor transmission rate of the moisture barrier layer is selected to be less than the moisture vapor transmission rate of the cover layer. | 1. A golf ball comprising: an inner core having a compression of less than about 65; at least one outer core layer surrounding the inner core and having a hardness of at least 80 Shore C and a specific gravity greater than or equal to a specific gravity of the inner core; and a cover surrounding the outer core layer; wherein the inner core has a hardness less than a hardness of the outer core. 2. The golf ball of claim 1, wherein the inner core hardness is about 78 Shore C and the outer core hardness is greater than about 90 Shore C. 3. The golf ball of claim 1, wherein the inner core compression is less than about 50 and the inner and outer cores have a combined dual core compression of from about 80 up to about 100. 4. The golf ball of claim 1, wherein the inner core specific gravity is about 1.13. 5. The golf ball of claim 1, wherein the inner core has a diameter of from about 1.4 inches to about 1.5 inches and the outer core has a thickness of from about 0.05 inches up to about 0.1 inches. 6. The golf ball of claim 1, wherein the inner core has a coefficient of restitution of from about 0.8 to about 0.825 and the inner and outer cores have a combined dual core coefficient of restitution of from about 0.805 up to about 0.83. 7. The golf ball of claim 1, wherein the inner core comprises about 100 pph of a polybutadiene rubber, greater than about 25 pph of a zinc diacrylate, greater than about 0.5 pph of an organic peroxide and a sufficient amount of filler to produce the inner core specific gravity. 8. The golf ball of claim 1, wherein the outer core comprises about 100 pph of a polybutadiene rubber, greater than about 0.6 pph of an organic peroxide, a sufficient amount of filler to produce the outer core specific gravity and more than about 35 pph of zinc diacrylate. 9. The golf ball of claim 1, wherein the cover layer has a thickness of from about 0.03 inches to about 0.04 inches. 10. The golf ball of claim 1, wherein the cover layer comprises polyurea or polyurethane. 11. The golf ball of claim 1, further comprising a moisture barrier layer disposed between the outer core layer and the cover layer, wherein the moisture barrier layer comprises a moisture vapor transmission rate that is less than a moisture vapor transmission rate of the cover layer. 12. The golf ball of claim 11, wherein the moisture barrier layer has a specific gravity of from about 1 to about 2, and a thickness of less than about 0.03 inches. 13. The golf ball of claim 11, wherein the moisture barrier layer comprises a styrene block copolymer and aluminum flake. 14. A golf ball comprising: an inner core having a compression of less than about 50; at least one outer core layer surrounding the inner core and having a hardness of at least 80 Shore C and a specific gravity of at least 1.1; and a cover surrounding the outer core layer; wherein the inner core has a hardness less than a hardness of the outer core and a specific gravity less than or equal to the outer core specific gravity. 15. The golf ball of claim 14, wherein the inner core hardness is about 78 Shore C and the outer core hardness is greater than about 90 Shore C. 16. The golf ball of claim 14, wherein the inner core compression and outer core compression are selected to provide a combined overall core compression of greater than about 50. 17. The golf ball of claim 14, wherein the inner core has a diameter of from about 1.4 inches to about 1.5 inches and the outer core has a thickness of from about 0.05 inches up to about 0.1 inches. 18. The golf ball of claim 14, wherein the inner core comprises about 100 pph of a polybutadiene rubber, greater than about 25 pph of a zinc diacrylate, greater than about 0.5 pph of an organic peroxide and a sufficient amount of filler to produce the inner core specific gravity. 19. The golf ball of claim 14, wherein the outer core comprises about 100 pph of a polybutadiene rubber, greater than about 0.6 pph of an organic peroxide, a sufficient amount of filler to produce the outer core specific gravity and more than about 35 pph of zinc diacrylate. 20. The golf ball of claim 14, further comprising a moisture barrier layer disposed between the outer core layer and the cover layer, wherein the moisture barrier layer comprises a moisture vapor transmission rate that is less than a moisture vapor transmission rate of the cover layer. 21. The golf ball of claim 20, wherein the moisture barrier layer has a specific gravity of from about 1 to about 2, and a thickness of less than about 0.03 inches. 22. The golf ball of claim 20, wherein the moisture barrier layer comprises a styrene block copolymer and aluminum flake. 23. A golf ball comprising: a multi-layer core comprising: an inner core having a Shore C hardness less than about 80 and a compression of less than about 70; and at least one outer core layer having a Shore C hardness of greater than about 80, an amount of zinc diacrylate of greater than about 35 pph; and a cover layer having a Shore D hardness of less than about 65; wherein at least one outer core layer has a moisture vapor transmission rate that is lower than that of the cover layer, and the multi-layer core has a diameter of greater than about 1.58 inches. 24. The golf ball of claim 23, wherein the outer core layer has a Shore C hardness of greater than about 90. 25. The golf ball of claim 24, wherein the zinc diacrylate level in the outer core layer is greater than about 40 pph. 26. The golf ball of claim 24, wherein the multi-layer core diameter is greater than about 1.6 inches. 27. The golf ball of claim 24, wherein the inner core comprises about 100 pph of a polybutadiene rubber, greater than about 25 pph of a zinc diacrylate, greater than about 0.5 pph of an organic peroxide and a sufficient amount of filler to produce the inner core specific gravity, the outer core comprises about 100 pph of a polybutadiene rubber, greater than about 0.6 pph of an organic peroxide, a sufficient amount of filler to produce the outer core specific gravity, and the cover layer comprises polyurea or polyurethane. 28. The golf ball of claim 24, wherein the inner core compression is less than about 50 and the inner and outer cores have a combined dual core compression of from about 80 up to about 100, the inner core has a specific gravity of about 1.05 and the outer core layer has a specific gravity less than the specific gravity of the inner core, the inner core has a diameter of from about 1.4 inches to about 1.5 inches, the outer core has a thickness of from about 0.05 inches up to about 0.1 inches, the cover layer has a thickness of from about 0.03 inches to about 0.04 inches, the inner core has a coefficient of restitution of from about 0.8 to about 0.825 and the inner and outer cores have a combined dual core coefficient of restitution of from about 0.805 up to about 0.83. 29. The golf ball of claim 29, further comprising an additional core layer surrounding the outer core layer and having a thickness of from about 0.005 inches to about 0.01 inches and a specific gravity of greater than 5. | CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 10/341,574, filed Jan. 13, 2003, which is a continuation-in-part of U.S. patent application Ser. No. 10/002,641, filed Nov. 28, 2001, now U.S. Pat. No. 6,547,677, which is a continuation-in-part of U.S. patent application Ser. No. 09/948,692, filed Sep. 10, 2001, which is a continuation-in-part of U.S. patent application Ser. No. 09/172,608, filed Oct. 18, 1998, now U.S. Pat. No. 6,302,808, which is a division of U.S. patent application Ser. No. 08/943,932, filed Oct. 3, 199, now U.S. Pat. No. 6,056,842; the '641 application is also a continuation-in-part of U.S. patent application Ser. No. 08,996,718, filed Dec. 23, 1997, now U.S. Pat. No. 6,124,389, which is a continuation-in-part of U.S. patent application Ser. No. 08/746,362, filed Nov. 8, 1996, now U.S. Pat. No. 5,810,678, which is a continuation-in-part of U.S. patent application Ser. No. 08/706,008, filed Aug. 30, 1996, now U.S. Pat. No. 5,813,923, which is a continuation-in-part of U.S. patent application Ser. No. 08/603,057, filed Feb. 16, 1996, now U.S. Pat. No. 5,759,676, which is a continuation-in-part of U.S. patent application Ser. No. 08/482,522, filed Jun. 7, 1995, now U.S. Pat. No. 5,688,191; the '641 application is also a continuation-in-part of U.S. patent application Ser. No. 09/630,387, filed Aug. 1, 2000, which is a continuation-in-part of U.S. patent application Ser. No. 08/603,057, filed Feb. 16, 1996, now U.S. Pat. No. 5,759,676; the '641 application is also a continuation-in-part of U.S. patent application Ser. No. 09/815,753, filed Mar. 23, 2001. The entire disclosures of these related applications are incorporated herein by reference. FIELD OF THE INVENTION The present is invention generally relates to golf balls and more particularly, the invention is directed to golf balls having multi-layered cores having a relatively soft, low compression inner core surrounded by a relatively rigid outer core. BACKGROUND OF THE INVENTION Golf balls have conventionally been constructed as either two piece balls or three piece balls. The choice of construction between two and three piece affects the playing characteristics of the golf balls. The differences in playing characteristics resulting from these different types of constructions can be quite significant. Three piece golf balls, which are also know as wound balls, are typically constructed from a liquid or solid center surrounded by tensioned elastomeric material. Wound balls are generally thought of as performance golf balls and have a good resiliency, spin characteristics and feel when struck by a golf club. However, wound balls are generally difficult to manufacture when compared to solid golf balls. Two piece balls, which are also known as solid core golf balls, include a single, solid core and a cover surrounding the core. The single solid core is typically constructed of a crosslinked rubber, which is encased by a cover material. For example, the solid core can be made of polybutadiene which is chemically crosslinked with zinc diacrylate or other comparable crosslinking agents. The cover protects the solid core and is typically a tough, cut-proof material such as SURLYN®, which is a trademark for an ionomer resin produced by DuPont. This combination of solid core and cover materials provides a golf ball that is virtually indestructible by golfers. Typical materials used in these two piece golf balls have a flexural modulus of greater than about 400,000 psi. In addition, this combination of solid core and cover produces a golf ball having a high initial velocity, which results in improved distance. Therefore, two piece golf balls are popular with recreational golfers because these balls provide high durability and maximum distance. The stiffness and rigidity that provide the durability and improved distance, however, also produce a relatively low spin rate in these two piece golf balls. Low spin rates make golf balls difficult to control, especially on shorter shots such as approach shots to greens. Higher spin rates, although allowing a more skilled player to maximize control of the golf ball on the short approach shots, adversely affect driving distance for less skilled players. For example, slicing and hooking the ball are constant obstacles for the lower skill level players. Slicing and hooking result when an unintentional side spin is imparted on the ball as a result of not striking the ball squarely with the face of the golf club. In addition to limiting the distance that the golf ball will travel, unintentional side spin reduces a player's control over the ball. Lowering the spin rate of the golf ball reduces the adverse effects of unintentional side spin. Hence, recreational players typically prefer golf balls that exhibit low spin rate. Various approaches have been taken to strike a balance between the spin rate and the playing characteristics of golf balls. For example, additional layers, such as intermediate core and cover layers are added to the solid core golf balls in an attempt to improve the playing characteristics of the ball. These multi-layer solid core balls include multi-layer core constructions, multi-layer cover constructions and combinations thereof. In a golf ball with a multi-layer core, the principal source of resiliency is the multi-layer core. In a golf ball with a multi-layer cover and single-layer core, the principal source of resiliency is the single-layer core. In addition, varying the materials, density or specific gravity among the multiple layers of the golf ball controls the spin rate. In general, the total weight of a golf ball has to conform to weight limits set by the United States Golf Association (“USGA”). Although the total weight of the golf ball is controlled, the distribution of weight within the ball can vary. Redistributing the weight or mass of the golf ball either toward the center of the ball or toward the outer surface of the ball changes the dynamic characteristics of the ball at impact and in flight. Specifically, if the density is shifted or redistributed toward the center of the ball, the moment of inertia of the golf ball is reduced, and the initial spin rate of the ball as it leaves the golf club increases as a result of lower resistance from the ball's moment of inertia. Conversely, if the density is shifted or redistributed toward the outer surface of the ball, the moment of inertia is increased, and the initial spin rate of the ball as it leaves the golf club would decrease as a result of the higher resistance from the golf ball's moment of inertia. The redistribution of weight within the golf ball is typically accomplished by adding fillers to one or more of the core or cover layers of the golf ball. Conventional fillers include the high specific gravity fillers, such as metal or metal alloy powders, metal oxide, metal searates, particulates, and carbonaceous materials and low specific gravity fillers, such as hollow spheres, microspheres and foamed particles. However, the addition of fillers may adversely interfere with the resiliency of the polymers used in golf balls and thereby the coefficient of restitution of the golf balls. However, there remains a need for high performance golf balls having a multi-core and relatively soft cover for good spin profile without using ionomer. SUMMARY OF THE INVENTION The present invention is directed to an improved golf ball displaying the desired spin profile and having a generally rigid, thermoset polybutadiene outer core surrounding a relatively soft, low compression inner core. Preferably, this golf ball has an inner core having a compression of less than about 50 and at least one outer core layer surrounding the inner core and having a hardness of at least 80 Shore C and a specific gravity of at least 1.1. The inner core has a hardness less than a hardness of the outer core and a specific gravity less than or equal to the outer core specific gravity. The inner core includes a polybutadiene rubber, zinc diacrylate, an organic peroxide and zinc oxide. In one embodiment, the inner core is made from about 100 pph of the polybutadiene rubber, about 34 pph of the zinc diacrylate, about 0.53 pph of the organic peroxide and a sufficient amount of the zinc oxide to produce the inner core specific gravity. The outer core includes a polybutadiene rubber, a stiffening agent, zinc diacrylate, an organic peroxide, zinc oxide and barytes filler, and in one embodiment is made from about 100 pph of the polybutadiene rubber, about 8 pph of the stiffening agent, about 0.66 pph of the organic peroxide, about 5 pph of the zinc oxide and about 35 pph of the zinc diacrylate. Suitable stiffening agents include balata and trans polyisoprene. Overall the inner core compression and outer core are formulated to provide a combined overall core compression of greater than about 50, preferably greater than about 70. The inner core has a diameter of from about 1.4 inches to about 1.5 inches and the outer core has a thickness of from about 0.05 inches up to about 0.1 inches. Overall, the inner core and outer core have a combined overall core diameter of greater than about 1.58 inches, preferably greater than about 1.60 inches. A cover layer is provided to surround and to cover the outer core layer. The cover layer has a thickness of from about 0.03 inches to about 0.04 inches and is constructed of either polyurea or polyurethane. The golf ball can also include a moisture barrier layer disposed between the outer core layer and the cover layer. The moisture vapor barrier protects the inner and outer cores from degradation due to exposure to moisture, for example water, and extends the usable life of the golf ball. The moisture vapor transmission rate of the moisture barrier layer is selected to be less than the moisture vapor transmission rate of the cover layer. The moisture barrier layer has a specific gravity of from about 1.1 to about 1.2 and a thickness of less than about 0.03 inches. Suitable materials for the moisture barrier layer include a combination of a styrene block copolymer and a flaked metal, for example aluminum flake. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawing which forms a part of the specification and is to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views: FIG. 1 is a cross-sectional representation of a golf ball formed in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, golf ball 10 in accordance with the present invention is constructed to provide the desired spin profile and playing characteristics. In an embodiment as illustrated, golf ball 10 includes core 16 and cover layer 15 surrounding core 16. In one embodiment, the diameter of core 16 is greater than about 1.58 inches. Preferably, the diameter of core 16 is greater than about 1.6 inches. In one embodiment, the compression of core 16 is greater than about 50. In another embodiment, the compression of core 16 is greater than about 70. In yet another embodiment, the compression of core 16 is from about 80 to about 100. As used herein, compression is measured by applying a spring-loaded force to the golf ball or golf ball component to be examined with a manual instrument (an “Atti gauge”) manufactured by the Atti Engineering Company of Union City, N.J. This machine, equipped with a Federal Dial Gauge, Model D8 1-C, employs a calibrated spring under a known load. The sphere to be tested is forced a distance of 0.2 inch against this spring. If the spring, in turn, compresses 0.2 inch, the compression is rated at 100. If the spring compresses 0.1 inch, the compression value is rated as 0. Thus more compressible, softer materials will have lower Atti gauge values than harder, less compressible materials. Compression measured with this instrument is also referred to as PGA compression. Core 16 includes inner core 11 and at least one outer core layer 13 surrounding inner core 11. Although illustrated as a dual layer core having a single outer core layer 13, other embodiments in accordance with the present invention can have two, three or more outer core layers. In one embodiment, an additional core layer (not shown) is provided surrounding outer core 13. This additional core layer can have a thickness of from about 0.005 inches to about 0.01 inches. In one embodiment, the specific gravity of the additional core layer is greater than about 5. In general, inner core 11 is constructed as a relatively soft, low compression core. In one embodiment, inner core 11 includes a base rubber, a cross linking agent, an initiator and a filler. The base rubber typically includes natural or synthetic rubbers. A preferred base rubber is a polybutadiene rubber. Examples of suitable polybutadiene rubbers include BUNA® CB22 and BUNA® CB23, commercially available from Bayer of Akron, Ohio; UBEPOL® 360L and UBEPOL® 150L, commercially available from UBE Industries of Tokyo, Japan; and CARIFLEX® BCP820 and CARIFLEX® BCP824, commercially available from Shell of Houston, Tex. If desired, the polybutadiene can also be mixed with one or more additional elastomers that are known in the art such as natural rubber, polyisoprene rubber and styrene-butadiene rubber in order to modify the properties of inner core 11. In one embodiment, the base rubber is present in an amount of about 100 parts per hundred (“pph”). Suitable cross linking agents include metal salts, such as a zinc salt or a magnesium unsaturated fatty acid, such as acrylic or methacrylic acid, having 3 to 8 carbon atoms. Examples include, but are not limited to, metal salt diacrylates, dimethacrylates, and monomethacrylates, wherein the metal is magnesium, calcium, zinc, aluminum, sodium, lithium, or nickel. Suitable acrylates include zinc acrylate, zinc diacrylate, zinc methacrylate, zinc dimethacrylate, and mixtures thereof. Preferably, the cross linking agent is zinc diacrylate. In one embodiment, the zinc diacrylate is provided as zinc diacrylate pellets having an 80% zinc diacrylate content. The cross linking agent is typically present in an amount greater than about 10 pph of the base rubber, preferably from about 20 to 40 pph of the base rubber, more preferably from about 25 to 35 pph of the base rubber. In one embodiment, the cross linking agent is present in an amount greater than about 25 pph. In another embodiment, the cross linking agent is present in an amount of about 34 pph. The initiator agent can be any known polymerization initiator that decomposes during the cure cycle. Suitable initiators include organic peroxide compounds, for example dicumyl peroxide; 1,1-di(t-butylperoxy)3,3,5-trimethyl cyclohexane; α,α-bis(t-butylperoxy)diisopropylbenzene; 2,5-dimethyl-2,5 di(t-butylperoxy)hexane; di-t-butyl peroxide; and mixtures thereof. Other examples include, but are not limited to, VAROX® 231XL and Varox® DCP-R, commercially available from Elf Atochem of Philadelphia, Pa.; PERKODOX® BC and PERKODOX® 14, commercially available from Akzo Nobel of Chicago, Ill.; and ELASTOCHEM® DCP-70, commercially available from Rhein Chemie of Trenton, N.J. A preferred organic peroxide initiator is Trigonox®, commercially available from Akzo Nobel Polymer Chemicals bv of Amersfoort, Netherlands. Suitable initiator levels include initial concentrations up to about 1 pph. In one embodiment, the initiator is present in an amount of greater than 0.5 pph. In another embodiment, the initiator level is about 0.53 pph. Fillers added to one or more portions of the golf ball typically include processing aids or compounds to affect rheological and mixing properties, density-modifying fillers, tear strength modifiers, reinforcement fillers, and the like. The fillers are generally inorganic, and suitable fillers include numerous metals or metal oxides, such as zinc oxide and tin oxide, as well as barium sulfate, barytes, zinc sulfate, calcium carbonate, barium carbonate, clay, tungsten, tungsten carbide, an array of silicas, and mixtures thereof. Fillers may also include various foaming agents or blowing agents that may be readily selected by one of ordinary skill in the art. Fillers can include polymeric, ceramic, metal, and glass microspheres and can be solid or hollow, and filled or unfilled. Fillers are typically also added to one or more portions of the golf ball to modify the density thereof to conform to uniform golf ball standards. Preferably, inner core 11 contains zinc oxide as the filler. The filler is present in an amount sufficient to produce the desired specific gravity in inner core 11. In one embodiment, inner core 11 can include unfilled or foamed density reducing material to reduce the specific gravity of the inner core 11, increasing the moment of inertia of golf ball 10. The constituents and constituent concentrations of inner core 11 are selected to produce the desired physical characteristics. Inner core 11 is selected to have a compression of less than about 70, preferably less than about 65, more preferably less than about 50. The hardness of inner core 11 is selected to be less than the hardness of outer core 13. In one embodiment, the hardness of inner core 11 is from about 70 to about 80 Shore C. Preferably, the hardness of inner core 11 is less than about 80 Shore C, for example about 78 Shore C. Inner core 11 has a specific gravity of less than about 1.13, for example from about 1 to about 1.1 or about 1.05. The coefficient of restitution of inner core 11 is from about 0.8 to about 0.825, preferably about 0.812. As used herein, the term “coefficient of restitution” (“COR”) for golf balls is defined as the ratio of the rebound velocity to the inbound velocity when balls are fired into a rigid plate. A discussion of COR and suitable test methods for measuring COR can be found, for example, in U.S. Pat. No. 6,547,677 B2, which is incorporated herein by reference. Inner core 11 is constructed to have a diameter of at least about 1 inch. In one embodiment, the diameter of inner core 11 is from about 1.4 inches up to about 1.5 inches. In another one embodiment, the diameter of inner core 11 is about 1.457 inches. Outer core 13 surrounds inner core 11 and is constructed to be more rigid than inner core 11. In one embodiment, outer core 13 includes a base rubber, a cross linking agent, an initiator, one or more fillers and, alternatively, a stiffening agent. Suitable base rubbers, cross linking agents, initiators and fillers are the same as those for inner core 11. In one embodiment the base rubber is a thermoset polybutadiene. The base rubber is present in an amount of about 100 pph. Zinc diacrylate is a preferred cross linking agent. In one embodiment, the cross linking agent is present in an amount of greater than 35 pph. In another embodiment, the amount of cross linking agent is greater than about 40 pph. In yet another embodiment, the cross linking agent is present in an amount of about 53 pph. Preferably, the initiator is an organic peroxide. In one embodiment, the organic peroxide is present in an amount greater than about 0.6 pph. In another embodiment, the organic peroxide is present in an amount of about 0.66 pph. A preferred filler is zinc oxide. In another embodiment, the filler also includes barytes. Fillers are added in an amount sufficient to impart the desired weight and physical characteristics, for example specific gravity, to outer core 13. In one embodiment, the filler can be present in an amount of about 5 pph. Suitable stiffening agents to be used in outer core 13 include balata and trans polyisoprene. Preferably, the stiffening agent is balata. These stiffening agents are commercially available under the tradenames TP251 and TP301. The stiffening agents are added to outer core 13 in an amount of from about 5 pph to about 10 pph. In one embodiment, the stiffening agent is present in an amount of about 8 pph. As with inner core 11, the constituents and constituent concentrations of outer core 13 are selected to produce the desired physical characteristics. In one embodiment, outer core 13 has a compression of about 90. In another embodiment the compressions of the inner and outer cores are selected to provided a combined dual core compression of from about 80 up to about 100. The hardness of outer core 13 is selected to be greater than or equal to about 80 Shore C. Preferably, the hardness is greater than or equal to 90 Shore C. In one embodiment, the flex modulus (per ASTM D-790) of outer core 13 is greater than about 30,000 psi. Outer core 13 has a specific gravity that is greater than or equal to the specific gravity of inner core 11. In one embodiment, the specific gravity of outer core 13 is greater than or equal to 1.1. In another embodiment, the specific gravity of outer core 13 is greater than or equal to 1.13. In yet another embodiment, the specific gravity of outer core 13 is about 1.24. Having the specific gravity of outer core 13 greater than the specific gravity of inner core 11 increases the moment of inertia and lowers the spin rate of golf ball 10. In one embodiment, the coefficient of restitution of outer core 13 is about 0.824. In another embodiment, the coefficient of restitution of the inner and outer core are selected to produce a combined dual core coefficient or restitution of from about 0.805 to about 0.83. Outer core 13 has a thickness of from about 0.05 inches up to about 0.1 inches. In one embodiment, outer core 13 has a thickness of about 0.075 inches. In general the diameter of inner core 11 and thickness of outer core 13 are selected to produce a diameter for core 16 that is greater than about 1.58 inches, preferably greater than about 1.6 inches. When golf ball 10 includes multiple outer core layers, each outer core layer can include the same materials as disclosed above for the inner core 11 and outer core 13, or different compositions. In one embodiment, at least one outer core layer is substantially stiffer and harder than inner core 11. In one embodiment, each one of the outer cores has a thickness of from about 0.001 inches to about 0.1 inches, preferably from about 0.01 inches to about 0.05 inches. Cover layer 15 surrounds outer core 13. Cover layer 15 can include any materials known to those of ordinary skill in the art, including thermoplastic and thermosetting materials, but preferably the cover layer can include any suitable materials, such as: (1) Polyurethanes, such as those prepared from polyols and diisocyanates or polyisocyanates and those disclosed in U.S. Pat. Nos. 5,334,673 and 6,506,851 and U.S. patent application Ser. No. 10/194,059; (2) Polyureas, such as those disclosed in U.S. Pat. No. 5,484,870 and U.S. patent application Ser. Nos. 60/401,047 and 10/228,311; and (3) Polyurethane-urea hybrids, blends or copolymers comprising urethane or urea segments. Cover layer 15 preferably includes a polyurethane composition comprising the reaction product of at least one polyisocyanate and at least one curing agent. The curing agent can include, for example, one or more diamines, one or more polyols, or a combination thereof. The at least one polyisocyanate can be combined with one or more polyols to form a prepolymer, which is then combined with the at least one curing agent. Thus, when polyols are described herein they may be suitable for use in one or both components of the polyurethane material, i.e., as part of a prepolymer and in the curing agent. The polyurethane composition may be used in forming the inner cover, outer cover, or both. In one preferred embodiment, the outer cover includes the polyurethane composition. In a different preferred embodiment, the curing agent includes a polyol curing agent. In a more preferred embodiment, the polyol curing agent includes ethylene glycol; diethylene glycol; polyethylene glycol; propylene glycol; polypropylene glycol; lower molecular weight polytetramethylene ether glycol; 1,3-bis(2-hydroxyethoxy)benzene; 1,3-bis-[2-(2-hydroxyethoxy)ethoxy]benzene; 1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}benzene; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; resorcinol-di-(β-hydroxyethyl)ether; hydroquinone-di-(β-hydroxyethyl)ether; trimethylol propane, or mixtures thereof. In one embodiment, the polyurethane composition includes at least one isocyanate and at least one curing agent. In yet another embodiment, the polyurethane composition includes at least one isocyanate, at least one polyol, and at least one curing agent. In a preferred embodiment, the isocyanate includes 4,4′-diphenylmethane diisocyanate, polymeric 4,4′-diphenylmethane diisocyanate, carbodiimide-modified liquid 4,4′-diphenylmethane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, p-phenylene diisocyanate, toluene diisocyanate, isophoronediisocyanate, p-methylxylene diisocyanate, m-methylxylene diisocyanate, o-methylxylene diisocyanate, or a mixture thereof. In another preferred embodiment, the at least one polyol includes a polyether polyol, hydroxy-terminated polybutadiene, polyester polyol, polycaprolactone polyol, polycarbonate polyol, or mixtures thereof. In yet another preferred embodiment, the curing agent includes a polyamine curing agent, a polyol curing agent, or a mixture thereof. In a more preferred embodiment, the curing agent includes a polyamine curing agent. In a most preferred embodiment, the polyamine curing agent includes 3,5-dimethylthio-2,4-toluenediamine, or an isomer thereof; 3,5-diethyltoluene-2,4-diamine, or an isomer thereof; 4,4′-bis-(sec-butylamino)-diphenylmethane; 1,4-bis-(sec-butylamino)-benzene, 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); trimethylene glycol-di-p-aminobenzoate; polytetramethyleneoxide-di-p-aminobenzoate; N,N′-dialkyldiamino diphenyl methane; p,p′-methylene dianiline; phenylenediamine; 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(2,6-diethylaniline); 4,4′-diamino-3,3′-diethyl-5,5′-dimethyl diphenylmethane; 2,2′,3,3′-tetrachloro diamino diphenylmethane; 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); or mixtures thereof. Any polyisocyanate available to one of ordinary skill in the art is suitable for use according to the invention. Exemplary polyisocyanates include, but are not limited to, 4,4′-diphenylmethane diisocyanate (“MDI”), polymeric MDI, carbodiimide-modified liquid MDI, 4,4′-dicyclohexylmethane diisocyanate (“H12MDI”), p-phenylene diisocyanate (“PPDI”), toluene diisocyanate (“TDI”), 3,3′-dimethyl-4,4′-biphenylene diisocyanate (“TODI”), isophoronediisocyanate (“IPDI”), hexamethylene diisocyanate (“HDI”), naphthalene diisocyanate (“NDI”); xylene diisocyanate (“XDI”); para-tetramethylxylene diisocyanate (“p-TMXDI”); meta-tetramethylxylene diisocyanate (“m-TMXDI”); ethylene diisocyanate; propylene-1,2- diisocyanate; tetramethylene-1,4-diisocyanate; cyclohexyl diisocyanate; 1,6-hexamethylene-diisocyanate (“HDI”); dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; methyl cyclohexylene diisocyanate; triisocyanate of HDI; triisocyanate of 2,4,4-trimethyl-1,6-hexane diisocyanate (“TMDI”), tetracene diisocyanate, naphthalene diisocyanate, anthracene diisocyanate, and mixtures thereof. Polyisocyanates are known to those of ordinary skill in the art as having more than one isocyanate group, e.g., di-, tri-, and tetra-isocyanate. Preferably, the polyisocyanate includes MDI, PPDI, TDI, or a mixture thereof, and more preferably, the polyisocyanate includes MDI. It should be understood that, as used herein, the term “MDI” includes 4,4′-diphenylmethane diisocyanate, polymeric MDI, carbodiimide-modified liquid MDI, and mixtures thereof and, additionally, that the diisocyanate employed may be “low free monomer,” understood by one of ordinary skill in the art to have lower levels of “free” monomer isocyanate groups than conventional diisocyanates, i.e., the compositions of the invention typically have less than about 0.1% free monomer groups. Examples of “low free monomer” diisocyanates include, but are not limited to Low Free Monomer MDI, Low Free Monomer TDI, and Low Free Monomer PPDI. The at least one polyisocyanate should have less than about 14% unreacted NCO groups. Preferably, the at least one polyisocyanate has no greater than about 7.5% NCO, more preferably, from about 2.5% to about 7.5%, and most preferably, from about 4% to about 6.5%. Any polyol available to one of ordinary skill in the art is suitable for use according to the invention. In one embodiment, the molecular weight of the polyol is from about 200 to about 6000. Exemplary polyols include, but are not limited to, polyether polyols, hydroxy-terminated polybutadiene (including partially/fully hydrogenated derivatives), polyester polyols, polycaprolactone polyols, and polycarbonate polyols. Examples include, but are not limited to, polytetramethylene ether glycol (“PTMEG”), polyethylene propylene glycol, polyoxypropylene glycol, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds and substituted or unsubstituted aromatic and cyclic groups. Preferably, the polyol of the present invention includes PTMEG. In another embodiment, polyester polyols are included in the polyurethane material of the invention. Suitable polyester polyols include, but are not limited to, polyethylene adipate glycol, polybutylene adipate glycol, polyethylene propylene adipate glycol, ortho-phthalate-1,6-hexanediol, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In another embodiment, polycaprolactone polyols are included in the materials of the invention. Suitable polycaprolactone polyols include, but are not limited to, 1,6-hexanediol-initiated polycaprolactone, diethylene glycol initiated polycaprolactone, trimethylol propane initiated polycaprolactone, neopentyl glycol initiated polycaprolactone, 1,4-butanediol-initiated polycaprolactone, and mixtures thereof. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. In yet another embodiment, the polycarbonate polyols are included in the polyurethane material of the invention. Suitable polycarbonates include, but are not limited to, polyphthalate carbonate. The hydrocarbon chain can have saturated or unsaturated bonds, or substituted or unsubstituted aromatic and cyclic groups. Polyamine curatives are also suitable for use in the curing agent of the polyurethane composition of the invention and have been found to improve cut, shear, and impact resistance of the resultant balls. Preferred polyamine curatives include, but are not limited to, 3,5-dimethylthio-2,4-toluenediamine and isomers thereof; 3,5-diethyltoluene-2,4-diamine and isomers thereof, such as 3,5-diethyltoluene-2,6-diamine; 4,4′-bis-(sec-butylamino)-diphenylmethane; 1,4-bis-(sec-butylamino)-benzene, 4,4′-methylene-bis-(2-chloroaniline); 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); polytetramethyleneoxide-di-p-aminobenzoate; N,N′-dialkyldiamino diphenyl methane; p,p′-methylene dianiline (“MDA”); m-phenylenediamine (“MPDA”); 4,4′-methylene-bis-(2-chloroaniline) (“MOCA”); 4,4′-methylene-bis-(2,6-diethylaniline); 4,4′-diamino-3,3′-diethyl-5,5′-dimethyl diphenylmethane; 2,2′,3,3′-tetrachloro diamino diphenylmethane; 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline); trimethylene glycol di-p-aminobenzoate; and mixtures thereof. Preferably, the curing agent of the present invention includes 3,5-dimethylthio-2,4-toluenediamine and isomers thereof, such as ETHACURE 300. Suitable polyamine curatives, which include both primary and secondary amines, preferably have weight average molecular weights ranging from about 64 to about 2000. At least one of a diol, triol, tetraol, or hydroxy-terminated curative may be added to the aforementioned polyurethane composition. Suitable diol, triol, and tetraol groups include ethylene glycol; diethylene glycol; polyethylene glycol; propylene glycol; polypropylene glycol; lower molecular weight polytetramethylene ether glycol; 1,3-bis(2-hydroxyethoxy)benzene; 1,3-bis-[2-(2-hydroxyethoxy)ethoxy]benzene; 1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}benzene; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; resorcinol-di-(4-hydroxyethyl)ether; hydroquinone-di-(4-hydroxyethyl)ether; and mixtures thereof. Preferred hydroxy-terminated curatives include ethylene glycol; diethylene glycol; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol, trimethylol propane, and mixtures thereof. Preferably, the hydroxy-terminated curatives have molecular weights ranging from about 48 to 2000. It should be understood that molecular weight, as used herein, is the absolute weight average molecular weight and would be understood as such by one of ordinary skill in the art. Both the hydroxy-terminated and amine curatives can include one or more saturated, unsaturated, aromatic, and cyclic groups. Additionally, the hydroxy-terminated and amine curatives can include one or more halogen groups. The polyurethane composition can be formed with a blend or mixture of curing agents. If desired, however, the polyurethane composition may be formed with a single curing agent. Any method known to one of ordinary skill in the art may be used to combine the polyisocyanate, polyol, and curing agent of the present invention. One commonly employed method, known in the art as a one-shot method, involves concurrent mixing of the polyisocyanate, polyol, and curing agent. This method results in a mixture that is inhomogenous (more random) and affords the manufacturer less control over the molecular structure of the resultant composition. A preferred method of mixing is known as a prepolymer method. In this method, the polyisocyanate and the polyol are mixed separately prior to addition of the curing agent. This method affords a more homogeneous mixture resulting in a more consistent polymer composition. The thickness of cover layer 15 is from about 0.03 inches up to about 0.04 inches. In one embodiment, the thickness of cover layer 15 is about 0.035 inches. In one embodiment, the cover layer has a hardness of less than about 65 Shore D. Although illustrated as having a single cover layer, golf ball 10 can have two or more cover layers to fine tune the spin and feel of golf ball 10. In one embodiment, golf ball 10 also includes moisture barrier layer 14 disposed between outer core 13 and cover layer 14. In one embodiment, moisture barrier layer 14 comprises at least one of the plurality of outer core layers. In another embodiment, moisture barrier layer 14 is a separate layer independent of the plurality of outer core layers. Moisture barrier layer 14 is selected to maintain the playing characteristics and initial velocity of golf ball 10 as the golf ball ages. In one embodiment, moisture barrier layer 14 is selected to have a moisture vapor transmission rate that is less than a moisture vapor transmission rate of cover layer 15. This inhibits moisture from entering into inner core 11 and outer core 13 and adversely affecting the properties of those layers. Examples of suitable moisture barrier layers 14 are disclosed in U.S. Pat. No. 6,632,147. The entire disclosure of this patent is incorporated herein by reference. In general, moisture barrier layer 14 has a moisture vapor transmission rate that is lower than that of the cover layer 15, and more preferably less than the moisture vapor transmission rate of an ionomer resin, which is in the range of about 0.45 to about 0.95 gram-mm/m2-day. The moisture vapor transmission rate is defined as the mass of moisture vapor that diffuses into a material of a given thickness per unit area per unit time. The preferred standards of measuring the moisture vapor transmission rate include ASTM F1249-90 entitled “Standard Test Method for Water Vapor Transmission Rate Through Plastic Film and Sheeting Using a Modulated Infrared Sensor,” and ASTM F372-99 entitled “Standard Test Method for Water Vapor Transmission Rate of Flexible Barrier Materials Using an Infrared Detection Technique,” among others. Moisture barrier layer 14 includes a styrene block co-polymer. Suitable styrene block co-polymers are available under the tradename Kraton® from Kraton Polymers of Houston, Tex. In addition, moisture vapor barrier layer 14 also has micro particles disposed therein. These particles are preferably hydrophobic and create a more tortuous path across moisture vapor barrier layer 14 to reduce the moisture transmission rate of layer 14. The micro particles may include nano particles, ceramic particles, flaked glass, and flaked metals (e.g., micaceous materials, iron oxide or aluminum). In one embodiment, moisture barrier layer 14 includes aluminum flake. The constituents, formulations and thickness of moisture barrier layer 14 are selected to provide the desired moisture transmission rate. In one embodiment, moisture barrier layer 14 has a specific gravity of from about I to about 2. In another embodiment, moisture barrier layer 14 has a specific gravity of about 1.13. The thickness of moisture barrier layer 14 is less than about 0.03 inches. In one embodiment, the thickness of moisture barrier layer 14 is about 0.024 inches. The arrangements and formulations of golf ball 10 are summarized in the following table: Moisture Outer core Multi- Barrier Cover Inner Core Layer Layer Core Layer Layer Property Hardness <outer core >80 Shore — — <65 Shore layer; <80 C; >90 D Shore C; Shore C about 78 Shore C Compression <70; <65; 80-100; >50; >70; — — <50 90 80-100 Specific Gravity 1-1.1; >s.g. of — 1-2; 1.13 — 1.05; <1.13 inner core; >1.1; 1.24 Diameter 1.4″-1.5″; — >1.58″; — — 1.457″ >1.6″ Thickness — 0.05″-0.1″; — <0.030″; 0.03″-0.04″; 0.075″; 0.024″ 0.035″ COR 0.8-0.825; 0.824 0.805-0.83 — — 0.812 MATERIAL CB23 100 pph 100 pph — — — TP301 — 8 pph — — — Zinc Diacrylate >25 pph; 34 pph >35 pph; >40 pph; — — — 53 pph Trigonox ® >0.5 pph; >0.6 pph; — — — 0.53 pph 0.66 pph Filler/Zinc Oxide Sufficient to Sufficient — — — produce s.g. to produce s.g.; 5 pph Barytes Filler — To weight — — — Kraton FG — — — Per — Formulation Aluminum Flake — — — Per — Formulation Polyurea/Polyurethane — — — — Per Formulation Golf ball 10 can be constructed by any known method that is generally known and available in the art. Suitable methods include methods for formulating and mixing the constituents of the various layers of golf ball 10. These methods also include methods for forming golf ball 10 including compression molding and injection molding. Examples of these methods can be found, for example, in U.S. patent application Ser. No. 10/341,574, which has been incorporated herein by reference, and U.S. Pat. No. 6,547,677, which is incorporated herein in its entirety. While it is apparent that the illustrative embodiments of the invention herein disclosed fulfill the objectives stated above, it will be appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments which come within the spirit and scope of the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>Golf balls have conventionally been constructed as either two piece balls or three piece balls. The choice of construction between two and three piece affects the playing characteristics of the golf balls. The differences in playing characteristics resulting from these different types of constructions can be quite significant. Three piece golf balls, which are also know as wound balls, are typically constructed from a liquid or solid center surrounded by tensioned elastomeric material. Wound balls are generally thought of as performance golf balls and have a good resiliency, spin characteristics and feel when struck by a golf club. However, wound balls are generally difficult to manufacture when compared to solid golf balls. Two piece balls, which are also known as solid core golf balls, include a single, solid core and a cover surrounding the core. The single solid core is typically constructed of a crosslinked rubber, which is encased by a cover material. For example, the solid core can be made of polybutadiene which is chemically crosslinked with zinc diacrylate or other comparable crosslinking agents. The cover protects the solid core and is typically a tough, cut-proof material such as SURLYN®, which is a trademark for an ionomer resin produced by DuPont. This combination of solid core and cover materials provides a golf ball that is virtually indestructible by golfers. Typical materials used in these two piece golf balls have a flexural modulus of greater than about 400,000 psi. In addition, this combination of solid core and cover produces a golf ball having a high initial velocity, which results in improved distance. Therefore, two piece golf balls are popular with recreational golfers because these balls provide high durability and maximum distance. The stiffness and rigidity that provide the durability and improved distance, however, also produce a relatively low spin rate in these two piece golf balls. Low spin rates make golf balls difficult to control, especially on shorter shots such as approach shots to greens. Higher spin rates, although allowing a more skilled player to maximize control of the golf ball on the short approach shots, adversely affect driving distance for less skilled players. For example, slicing and hooking the ball are constant obstacles for the lower skill level players. Slicing and hooking result when an unintentional side spin is imparted on the ball as a result of not striking the ball squarely with the face of the golf club. In addition to limiting the distance that the golf ball will travel, unintentional side spin reduces a player's control over the ball. Lowering the spin rate of the golf ball reduces the adverse effects of unintentional side spin. Hence, recreational players typically prefer golf balls that exhibit low spin rate. Various approaches have been taken to strike a balance between the spin rate and the playing characteristics of golf balls. For example, additional layers, such as intermediate core and cover layers are added to the solid core golf balls in an attempt to improve the playing characteristics of the ball. These multi-layer solid core balls include multi-layer core constructions, multi-layer cover constructions and combinations thereof. In a golf ball with a multi-layer core, the principal source of resiliency is the multi-layer core. In a golf ball with a multi-layer cover and single-layer core, the principal source of resiliency is the single-layer core. In addition, varying the materials, density or specific gravity among the multiple layers of the golf ball controls the spin rate. In general, the total weight of a golf ball has to conform to weight limits set by the United States Golf Association (“USGA”). Although the total weight of the golf ball is controlled, the distribution of weight within the ball can vary. Redistributing the weight or mass of the golf ball either toward the center of the ball or toward the outer surface of the ball changes the dynamic characteristics of the ball at impact and in flight. Specifically, if the density is shifted or redistributed toward the center of the ball, the moment of inertia of the golf ball is reduced, and the initial spin rate of the ball as it leaves the golf club increases as a result of lower resistance from the ball's moment of inertia. Conversely, if the density is shifted or redistributed toward the outer surface of the ball, the moment of inertia is increased, and the initial spin rate of the ball as it leaves the golf club would decrease as a result of the higher resistance from the golf ball's moment of inertia. The redistribution of weight within the golf ball is typically accomplished by adding fillers to one or more of the core or cover layers of the golf ball. Conventional fillers include the high specific gravity fillers, such as metal or metal alloy powders, metal oxide, metal searates, particulates, and carbonaceous materials and low specific gravity fillers, such as hollow spheres, microspheres and foamed particles. However, the addition of fillers may adversely interfere with the resiliency of the polymers used in golf balls and thereby the coefficient of restitution of the golf balls. However, there remains a need for high performance golf balls having a multi-core and relatively soft cover for good spin profile without using ionomer. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is directed to an improved golf ball displaying the desired spin profile and having a generally rigid, thermoset polybutadiene outer core surrounding a relatively soft, low compression inner core. Preferably, this golf ball has an inner core having a compression of less than about 50 and at least one outer core layer surrounding the inner core and having a hardness of at least 80 Shore C and a specific gravity of at least 1.1. The inner core has a hardness less than a hardness of the outer core and a specific gravity less than or equal to the outer core specific gravity. The inner core includes a polybutadiene rubber, zinc diacrylate, an organic peroxide and zinc oxide. In one embodiment, the inner core is made from about 100 pph of the polybutadiene rubber, about 34 pph of the zinc diacrylate, about 0.53 pph of the organic peroxide and a sufficient amount of the zinc oxide to produce the inner core specific gravity. The outer core includes a polybutadiene rubber, a stiffening agent, zinc diacrylate, an organic peroxide, zinc oxide and barytes filler, and in one embodiment is made from about 100 pph of the polybutadiene rubber, about 8 pph of the stiffening agent, about 0.66 pph of the organic peroxide, about 5 pph of the zinc oxide and about 35 pph of the zinc diacrylate. Suitable stiffening agents include balata and trans polyisoprene. Overall the inner core compression and outer core are formulated to provide a combined overall core compression of greater than about 50, preferably greater than about 70. The inner core has a diameter of from about 1.4 inches to about 1.5 inches and the outer core has a thickness of from about 0.05 inches up to about 0.1 inches. Overall, the inner core and outer core have a combined overall core diameter of greater than about 1.58 inches, preferably greater than about 1.60 inches. A cover layer is provided to surround and to cover the outer core layer. The cover layer has a thickness of from about 0.03 inches to about 0.04 inches and is constructed of either polyurea or polyurethane. The golf ball can also include a moisture barrier layer disposed between the outer core layer and the cover layer. The moisture vapor barrier protects the inner and outer cores from degradation due to exposure to moisture, for example water, and extends the usable life of the golf ball. The moisture vapor transmission rate of the moisture barrier layer is selected to be less than the moisture vapor transmission rate of the cover layer. The moisture barrier layer has a specific gravity of from about 1.1 to about 1.2 and a thickness of less than about 0.03 inches. Suitable materials for the moisture barrier layer include a combination of a styrene block copolymer and a flaked metal, for example aluminum flake. | 20040206 | 20070814 | 20050616 | 76969.0 | 1 | GORDEN, RAEANN | MULTI-LAYER CORE GOLF BALL | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,774,329 | ACCEPTED | Apparatus for brewing beverages | An electrically heated water kettle comprises a vessel for holding a liquid for extraction of tea, coffee or other food material. The vessel includes a partially open immersible container sized to allow the passage of water between the walls of the vessel. The container is capable of holding the material while an opening in the container allows the entrance of water into the container upon immersion of the container in the water. The heated kettle incorporates structure to hold the container out of the water until the water reaches an appropriate extraction temperature and to immerse or withdraw the container into or from the water as is necessary to accomplish the extraction. | 1. An electrically heated liquid kettle comprising a vessel for holding a liquid for extraction of tea, coffee, or other food material, said vessel including a partially open immersible container sized to allow passage of liquid between the walls of said vessel, said container being capable of holding the material while providing an opening in said container to allow entrance of liquid therein upon immersion of said container in liquid, and said heated kettle incorporating structure to hold said container out of the liquid until the liquid reaches appropriate extraction temperature and to immerse or withdraw said container into or from liquid as necessary to accomplish said extraction. 2. An electrically heated liquid kettle according to claim 1 where said structure to hold said container is a rod attached to said container, said rod extending to the exterior of said vessel. 3. An electrically heated liquid kettle according to claim 1 where said structure to hold said container out of liquid is a mechanical arm actuated by an electromagnetic solenoid that presses against a physical feature of said container. 4. An electrically heated liquid kettle according to claim 3 with an electrical switching structure to actuate said electromagnetic solenoid to hold or release said container. 5. An electrically heated liquid kettle according to claim 1 where said structure to hold said container is an electromagnet, and said container including a ferromagnetic structured element attracted and held by a magnetic field of said electromagnet. 6. An electrically heated liquid kettle according to claim 1 containing said partially open immersible container, said opening to allow entrance of liquid at least in part being a meshed screen and an adjustable shutter adjacent said screen to permit the adjustment of the effective area of the entrance of liquid. 7. An electrically heated liquid kettle according to claim 1 including user operated electrical controls to preprogram the desired extraction temperature and to preprogram the desired brewing time. 8. An electrically heated liquid kettle according to claim 7 including an electrical processor to store a more than one combination of programmed temperature and times selected for different brewing conditions and to permit user access to said combinations. 9. An electrically heated liquid kettle comprising a vessel for holding a liquid for extraction of tea, coffee or other food material, an electric heater powered by an electrical controller to heat the liquid to a predetermined set temperature, a sensor to measure temperature of the liquid and create an electronic temperature signal corresponding to the temperature, an electrical processor to make a comparison of said set temperature with said temperature signal and to direct said electrical controller to apply varying amounts of power to said heater in response to said comparison. 10. An electrically heated liquid kettle according to claim 9 where said processor directs said controller to apply maximum power to said heater during the heat up and further directs said heater to apply less than maximum power to said heater as the temperature of said liquid approaches the set temperature. 11. An electrically heated liquid kettle comprising a vessel for holding a liquid for extraction of coffee, tea, or other food material, an electric heater to heat the liquid to a predetermined set temperature selected by the user, a visual indicator of said set temperature selected by the user, a precise electrical sensor of temperature of the liquid and an electrically powered visual or audible alarm that annunciates when said liquid temperature reaches said set temperature. 12. An electrically heated liquid kettle comprising a vessel for holding a liquid for extraction of tea, coffee or other food material, an electric heater powered by an electrical controller directed by an electrical processor to heat the liquid to a predetermined set temperature and to maintain the liquid at said set temperature, and a user actuated electrical control to initiate the brewing cycle time of the material. 13. An electrically heated liquid kettle according to claim 12 where said user control also directs said processor to direct said controller to maintain said liquid at said set temperature for at least some portion of the brewing cycle time of said material. 14. An electrically heated liquid kettle according to claim 12 where said user control directs said processor to direct said controller to initiate the brewing cycle time of the material and to terminate the maintenance of said set temperature during the brewing cycle time. 15. An electrically heated liquid kettle according to claim 12 including a partially open immersible container for the food material, an electrically actuated holder to maintain said container above the liquid, and the said user actuated electrical control initiates the said brewing cycle time and actuates said holder to allow said container to immerse in the liquid. 16. An electrically heated liquid kettle according to claim 12 comprising an electric timer settable to a selected length of brewing time where said user actuated electrical control initiates the brewing cycle time of the material and directs said timer to count down the time and to initiate a visual or audible alarm to announce the end of said cycle time. 17. An electrically powered heated liquid kettle comprising a lidded but unsealed vessel for holding a vaporizable liquid, a heater capable of heating the liquid in said vessel to the boiling temperature of the liquid at the prevailing atmosphere pressure, a sensor for measuring the temperature of the liquid or the temperature of the air/vapor mixture immediately above the liquid in said vessel and generating an electrical signal corresponding to said temperature, and an electrical processor to receive said signal and to analyze the rate of rise of said signal with the power applied to said heater as an indicator of boiling of said liquid when the measured temperature levels off and to cause the interruption or reduction of power to said heater. 18. An electrically powered heated kettle comprising a lidded but unsealed vessel for holding a vaporizable liquid, a heater capable of heating the liquid in said vessel to the boiling point of the liquid at the prevailing atmospheric pressure, an electrical control to preset the desired temperature of the liquid, an electrical signal processor directed by said electrical control to direct a controller of the flow of electrical power to said heater, an electrical sensor to generate an electrical signal proportioned to the temperature of the liquid or the air/vapor mixture directly above the liquid in said vessel as the liquid is heated by said heater to the boiling point, and to transmit said signal to said electrical processor, whereby said processor can determine therefrom when the liquid is boiling, to determine and store the exact value of temperature of said boiling point and to prevent the subsequent adjustment of said set desired temperature to any value above said boiling temperature as established by said processor. 19. An electrically heated covered liquid kettle comprising a vessel for holding a liquid material for the extraction of tea, coffee or other food material, the interior walls of said vessel being of nominally uniform internal dimensions along a major length of said vessel, a manually operated removable screen-like filter contacting and close fitting to said interior walls along said major length of said vessel, a manually operated partially open immersible container capable of holding the material spaced sufficiently apart from said walls to allow free passage of liquid between the walls of said vessel and said container, and one or more manually operated physical members extending through said cover used individually or interchangeably to hold said screen-like filter and said container above the liquid and to lower said filter and said container into the liquid. | CROSS-REFERENCE TO RELATED APPLICATION This application is based on provisional application Ser. No. 60/445,370, filed Feb. 6, 2003. BACKGROUND OF THE INVENTION A wide range of means have been disclosed for the brewing of tea and coffee including percolators, drip methods, and french press. The french press is among the most effective means for extracting the best flavors from tea leaves and ground coffee. The most common french presses are non electric and depend upon preheating the water by conventional means and transferring the hot water to a french press for extraction of the tea leaves or coffee. The electric french press is a similar means to prepare such beverages that boils the water directly in the kettle to insure that the water is at boiling temperature at the start of the brewing cycle. A conventional electric french press type kettle such as described in PCT WO 00/40128 and (PCT/EP99/10357) (DE 19706523A1) is a glass or plastic water vessel with an electric heater plate which is in contact with the water. In such prior art, electrical connection to the kettle and the heater is commonly made through a detachable supporting base that contains an electrical connector which inserts into an electrical socket on the underside of the base enclosure of the kettle. It is common also for the kettle to have a handle on which there is a steam actuated electrical switch that will interrupt all power to the heater plate whenever the water boils and generates steam. However, these conventional brewing devices lack versatility, lack sufficiently precise control of the water temperature during the actual brewing process and have other limitations found to be objectionable by the serious consumer of these beverages. SUMMARY OF THE INVENTION This invention is an advanced electric brewing kettle that provides means for adjusting the water temperature precisely to any value for optimum extraction of a wide variety of coffees and teas. The optimum temperatures for extracting green teas is much lower than the black teas. Coffees are generally best extracted at a particular temperature just below the boiling point of water, selected for a favorite coffee and personal tastes. The improved apparatus described here is designed so that the user can operate it either similarly to a French press or as an improved extractor that allows the coffee, tea or other extractable food to be preheated and steamed before the liquid extraction takes place. This invention incorporates an improved means of containing the tea leaves or ground coffee during the extraction and steeping process. By this novel means the contained tea or coffee can be immersed in the water exactly at the optimum brewing temperature and can be removed completely from the water after the precisely optimum steeping or brewing time, thereby stopping abruptly any further extraction. By stopping extraction the more bitter ingredients in the tea leaves or coffee grounds are not extracted and mixed with the more flavorful flavorants already extracted into the water. Further the opportunity for any of the fine grinds from the coffee or tea to remain in the extracted tea or coffee is virtually eliminated—unlike the situation with french presses where the extracted fragments of the tea or coffee remain in the kettle as the beverage is poured. These conventional means aversely affect taste of the beverage and allows unfiltered solids to be poured with the liquid. An added advantage provided by this novel means is that the ground coffee or tea leaves confined within a semi-open container can remain in the kettle above the water level during the time that the water is being heated—thereby allowing the steam to penetrate and swell the tea leaves or ground coffee before they are immersed in the water for extraction. This swelling process or “blooming” allows the extraction time during immersions to be more efficient and shortens the extraction time. Unique, electrical and electric means provide ability to precisely control the extraction time and the extraction temperature, and to adjust operating procedures to adapt to changes in the boiling point due to localized atmospheric pressure especially at higher elevations. THE DRAWINGS FIG. 1 is a side elevational view partially broken away of an apparatus for brewing beverages in accordance with this invention; FIG. 2 is a top plan view of the apparatus shown in FIG. 1; FIG. 3 is a cross-sectional view taken through FIG. 1 along the line 3-3; FIG. 4 is a cross-sectional top plan view of a beverage container used in the apparatus of FIGS. 1-3; FIG. 5 is a perspective view of the container system used in the apparatus of FIGS. 1-4; FIG. 6 is a top plan view of the upper cover section of the apparatus shown in FIGS. 1-5; FIG. 7 is a bottom plan view of the lower basket section using the apparatus of FIGS. 1-5; FIG. 8 is an exploded side elevational view showing the upper cover section for the lower basket section of the apparatus shown in FIGS. 1-5; FIG. 9 is a cross-sectional plan view of a portion of the apparatus shown in FIGS. 1-5; FIG. 10 is a circuit diagram for the apparatus shown in FIGS. 1-5; FIG. 11 is a block diagram showing the relationship of the various components of the apparatus shown in FIGS. 1-5; FIG. 12 is a side elevational view of a portion of the apparatus shown in FIGS. 1-5; FIG. 13 is a side elevational view partly in section of a portion of the apparatus shown in FIGS. 1-5; FIG. 14 is a side elevational view of a cover used in the apparatus shown in FIGS. 1-5; and FIGS. 15-16 are side elevational views partly in section of further embodiments of this invention. DETAILED DESCRIPTION An improvement of this invention is a unique container system which can hold ground coffee or tea leaves within the kettle but out of the water until it is heated to the optimum temperature. FIG. 1 shows an electrically heated kettle 1 with a glass or plastic shell vessel 2, a handle 7 with one or more control switches 55 and LEDs 53,54 and 60 mounted on the handle. The unique container system 10 is supported above the liquid on the lower end of control rod 15 which passes thru the kettle cover 23. The container can be lowered manually or in alternative models by an automated means beneath the surface of the water in the kettle during the extraction cycle. An electric heater plate 3 is attached to the bottom of the kettle shell 2. Preferably the heater plate 3 forms the bottom of the kettle being sealed to the kettle in a manner that insures that one side of plate 3 is in direct contact with the water. Attached to the bottom of the heater plate 3 is an electrically powered heater 19. Power applied to this heater is controlled by a uniquely programmed electronic processor and controller. Temperature of the water is measured by a thermocouple, thermistor 27 or similar temperature sensor that plugs into processor 47 mounted in enclosure 6. The temperature sensor 27 is mounted either in direct contact with the heated water, the kettle shell or under the lower heater plate 3 which in turn remains in intimate contact with the heated water. The entire apparatus is powered thru power cord 25 connected through base 4 in which is mounted a cordless connector of a type similar to that commercially available from Otter, Strix and other suppliers. Power to the kettle itself is passed through this connector by a plug 29 extending from the base 4 that goes into socket 30 attached to the base of the heater plate 3 in the enclosure 6 which supports the kettle and serves to enclose certain electrical components mounted under the kettle and the heater plate 3. While a cordless kettle is generally preferred, the kettle can be connected directly by means of a power cord to the local household power outlets. The filled food container 10 can be immersed in the heated water at the beginning of the extraction process and held there for the extraction cycle. At that time the container 10 can be raised above the heated liquid in order to abruptly terminate the extraction process. The container while in the water can be held in one position or if desired it can be moved up and down manually or mechanically in order to enhance the flow of water through the container providing better contact with the tea leaves or ground coffee in order to enhance the extraction efficiency or to achieve a different type of extraction and taste balance. Container system 10 (FIG. 3) consists of an upper section 11 (FIGS. 5 and 8) to which is attached a lower basket section 12 that holds the tea leaves or ground coffee. The lower basket section 12 is attached to the upper section 11 by aligning the pins on the lower basket 12 to the slots in the upper section 11, inserting the basket 12 into the upper section and rotating the lower section 12 to secure its position. The lower section 12 can be removed from the upper section 11 even while upper section 11 remains attached to rod 15. Rod 15 (FIGS. 1, 3 and 5) attaches securely to the upper section 111 of the container system 10 to permit raising and lowering the container system within the kettle. The container system 10 is designed with a diameter or outer dimension smaller than the internal diameter or dimension of kettle 2 so that the container system can be moved freely up and down and the water or steam is free to flow around the system as it is moved up or down or as the final tea or coffee is poured out of the kettle. Water also can enter or flow through the container which is enclosed for example with a screen-like structure attached to the supporting arms 17 (FIGS. 5 and 6) and supporting arms 18 of FIG. 7 on the upper and lower ends of the container system respectively. Openings in the screens can be adjustable or in any event the individual openings are sufficiently small to contain the tea leaves and coffee grounds yet large enough to allow water to move into and out of the container system. Because the container physically isolates the coffee or tea being extracted, the extracted solid residue held within container system 10 is readily removed from the kettle 2 thus leaving the kettle relatively clean and hence requiring little to no effort to clean it. Multiple brew cycles are possible without cleaning the kettle. Once the tea or coffee is brewed the container assembly 10 can remain in the water but preferably it will be raised above the water level to stop the extraction. It can of course be removed completely from the kettle and if one wishes a pouring lid 9, (FIG. 14) can be placed on the kettle 2 before the tea or coffee is poured out of the kettle. Slots 9a in the lid allow the lid to be tight fitting yet the beverage can be easily poured out of the kettle with the lid in place. Critical to producing beverages of optimum flavor is the temperature at which the flavors are extracted and the time of contact with the liquid during extraction. Coffees and teas contain a wide range of organic flavorants. Some of the flavorants are very aromatic, some less. Some components add a bitter taste and are generally to be avoided. The amount of these various flavorants extracted depends on the exact temperature of the water. As the water temperature increases the solubility of each component will change and the rate of extraction increases with temperature. Further the rate of extraction of any component varies with the concentration of that component already in solution. Clearly as the extraction time is increased the concentration of the individual flavorants generally continues, but importantly the ratio of key flavorants is altered sufficiently to be perceptible to anyone with sensitive taste. Consequently the ultimate ratio of flavorants depends on time, temperature, amount of tea or coffee, degree of confinement of the liquid around the tea or coffee and the liquid agitation within the brewing environment. All of these factors must be carefully controlled and clearly if the brewing environment and apparatus allows these variables to be changed by the user, the user will be able to optimize conditions to tailor his beverage to his own taste. The advanced brewing means disclosed here has the necessary versatility to allow the user to modify the brewing conditions to best match each type of tea or brand of coffee. Thus this novel appliance permits individual but precise control of the brewing temperature and brewing time, while providing the means for preconditioning of the tea of coffee before brewing, and control over agitation during the brewing process. The coffee or tea is placed in a semi-enclosed container whose exterior enclosing surfaces contain a number of small openings to allow water or steam to enter the container during the blooming and during the extraction periods. Commonly a screening type material is used to provide for liquid transfer in and out of the container. The individual openings however are sufficiently small to prevent the ground coffee particles or tea leaves and fragments from passing thru the openings. The number of such openings and the total open area on the surface are important to control the degree of flow or diffusion of liquid and steam into and out of the enclosure. If the open area is large the extraction will result in a flavorant mixture that approaches that obtained by simply pouring the coffee or tea into the heated water. If the total area open for flow of water or steam is small, the conditions and flavor will approach that of a samovar where the tea is confined in only a small volume of water as the extraction occurs. Provision can be made to allow for adjustment of the number of openings or the area of screen in use at any one time. That adjustment can be easily obtained for example by using adjustable close fitting shutters 31 adjacent to the screened area as in FIG. 9, adjusted by a manual means such as lever 33. The degree of adjustment of the open screened area shown in FIG. 9 ranges approximately from 25% to 75% open area. It is more convenient in some models to provide a range of 0 to 100%. The design of this advanced brewing means offers the user a choice among a variety of alternative brewing processes. First it is possible to use this in a way similar to a conventional french press which allows him to drop the coffee or tea directly into the heated water, to allow the extraction process to take place around individual particles of coffee or tea leaves surrounded with the large volume of water. The particles drift downward as they wet, then tend to accumulate at the bottom of the kettle and after extraction are mechanically confined by pressing down a screen-like filter tightly conforming to the walls of the chamber to confine the particles at the bottom of the press. They remain there subsequently as the tea or coffee is poured and consumed. Leaving the coffee or tea in the press as the beverage is consumed permits continued extraction of some of the more bitter flavorants—adversely affecting the flavor of the beverage. While some users may enjoy the increasingly stronger beverage as the extraction continues over such extended periods, most experts find this detrimental to the flavor or taste. An important improvement, however of the versatile new product disclosed here allows the user to first steam or moisten the coffee or tea which allows the particles to soften and swell (bloom) increasing their total surface area and facilitating better control of the extraction conditions. This new product also permits one to use the novel container, immerse it without agitation at the precisely optimum temperature for an optimum time and to then withdraw it completely from the heated vessel before pouring the beverage. In the other extreme the user can move the container up and down within the water or into and out of the water to obtain maximum extraction of all flavorants in the shortest possible time. Consequently this novel means provides a variety of reproducible and controlled brewing options allowing the user to optimize the flavor of his coffee, tea or other extractable material to suit his individual preferences. In order to provide this extreme brewing flexibility this novel apparatus employs, advanced means for controlling the temperature and time with high accuracy, means for compensating for changes in boiling point due to changes in atmospheric pressure, means for keeping the beverage warm after brewing is complete and means in advanced models to automatically initiate the brewing process. These advantages will be clear as the operation of this new product is further described. Because it may be desired to use this electric kettle simply to boil water for preparation of hot chocolate, soups, etc., protection must be built in to prevent continuous boiling with the possibility of boiling the kettle dry and overheating the unit creating a hazardous situation. Provision is provided in this advanced system to avoid such a possibility while at the same time giving the user the option of setting the water temperature just below boiling such as 211° F. when the actual boiling point at sea level is 212° F. To control the absolute temperature with an accuracy of less than 1° F. is possible but very costly and perhaps impractical for a home appliance. Consequently a novel electronic processor is used to monitor an electronic signal from an incorporated thermal detector in this product to detect the presence of boiling regardless of the temperature at which the water boils depending on the local barometric pressure. The electronic processor simultaneously monitors with aid of a temperature sensor the temperature of the water or of the steam/air mixture just above the water and if the water does boil, the processor retains the precise temperature measurement and notes that as the local boiling point. Subsequently the processor advises the user that he must manually set his desired temperature below that boiling temperature, limits the users ability to set his desired temperature at or above the boiling point, or otherwise prevents this apparatus from continuing to heat the water beyond its local boiling temperature. This brewing apparatus provides a means for the user to set his desired brewing temperature with great accuracy. For green tea this may even below 150 degrees Fahrenheit while for black tea or coffee he may wish to set the temperature at or just below the boiling point. Other teas and coffees fall generally within this range of temperatures. It is important therefore to sense the water temperature accurately and to display the temperature setting accurately by means of either or mechanical or electrical means. Perhaps the most convenient and accurate means of sensing the water temperature electronically is with either a thermocouple precision thermistor or other means in excellent thermal contact with the water or contacting a highly thermally conductive thin material separating the sensor from the heated water. Because of the high thermal conductivity of the metal heater plate in contact with the heating water the dry side of the heater plate provides a convenient and practical place to monitor the water temperature. That plate can alternatively be provided with a thin walled thermal well, protruding into the liquid, in which to mount a thermistor or thermocouple. Alternatively the sensor can be mounted on an internal wall of the kettle to achieve even greater thermal accuracy. An electrical heater for the water is mounted on a metal plate, for example made of steel or aluminum, one side of which is in good thermal contact with the water in the kettle. The heater must provide a large amount of power in order to heat the water quickly but substantially less power is required to maintain the heated water and kettle once the desired temperature is reached. Consequently it is desirable to have a high wattage heater for example in the range of 1000-1500 watts to heat the water quickly. Once the water is heated to the control temperature not more than about 100 to 200 watts is needed to maintain it there. This novel brewing apparatus uses a single high wattage heater to permit rapid heat up of the water but incorporates an electronic controller that regulates the intermittent flow of electrical power applied to that same large power heater as a means of reducing the effective wattage of the large heater during the keep warm cycle. This unique means avoids the need for two heaters of different wattage, inefficient and expensive resistors, conventional relays, or mechanical thermostats. The controller thus sends short-time bursts of full power to the large heater at just the correct frequency and duration to maintain the water at precisely the desired temperature. Commonly the controller sends many pulses each second. The effective wattage required will of course be larger if there is more water in the kettle or if the water is maintained at a higher temperature than if the water is closer to room temperature. This novel brewing apparatus also includes means to keep the beverage warm after the brewing cycle is complete. The electronic processor 47 is programmed to adjust automatically in response to the thermal sensor 27 the frequency and duration of electrical power pulses applied to the heater 19 to maintain the beverage at a preselected temperature such as 160° C. Controls are provided to enable the user to change this “keep-warm” temperature in order to provide a cooler or warmer beverage. This advanced means of varying the wattage of the heater insures that just the correct amount of energy is applied to the heater and kettle. Excessive power is never applied to the heater. Consequently and importantly unlike conventional heating means the temperature of the heater plate 3 is never heated in the “keep-warm” mode to more than a few degrees above the average temperature of the beverage in the kettle, thus avoiding overheating the beverage and adversely affecting its temperature. It is important to minimize the amount of energy required to “keep-warm” the beverage in order to minimize any modification of the optimum flavor of the beverage. Any heating implies some differential in temperature between the heating source such as the heating plate and the liquid. To further reduce that differential temperature, it is desirable to reduce heat loss from the kettle, especially during the “keep-warm” period which may be well in excess of an hour. A convenient way to reduce such losses is to use an insulating double walled kettle 2 preferably with a good vacuum in the inner space between the double walls. Conventional thermal insulating materials can also be used around the kettle to reduce the heat loss. Another novel means is an electrically heated blanket or a circular flexible or rigid heated enclosure maintained at the “keep warm” temperature, conforming closely to the exterior of the kettle. Such warmed means that surround the large area of kettle walls require a vanishingly small temperature differential between the heated blanket and kettle to maintain the beverage at the “keep-warm” temperature. The signal generated by the temperature sensor, proportional to the water temperature is fed to an electronic processor and the signal from a means to set the temperature level selected by the user is likewise fed to the processor. The processor compares these two signals and directs the controller to apply the appropriate amount of power to the heater to either heat the water rapidly or to apply a lessor amount of heat—just enough to maintain the temperature at the set temperature. The processor uses modern solid state integrated chip technology to handle electronic inputs, to manipulate and compare input signals, to make the logic decisions, to convert analog signals from sensors to digital form, to make necessary calculations and to direct the controller regarding the appropriate power that must be applied to the heating elements. The controller can adjust the power to the heater either by use of electrically actuated mechanical relays, by means of solid state Triacs™, thyristors, solid state relays and can employ time based pulse width modulation methods for controlling the amount of power transferred. This brewing device will preferably have an electronic display conveniently accessible to the user to display the set temperature (the desired brewing temperature) with manually operated control buttons that allow the user to set the temperature higher or lower. A conventional LED (light emitting diode) or LCD (liquid crystal device) can be used to display conventionally the set water brewing temperature or the same display can be directed to read-out the actual water temperature. This same display can be used also to display brewing time and to display “remaining brewing time” to indicate and advise the user as the brewing proceeds and ends. When the brewing cycle ends visual and/or audible indications or alarms can be made to advise the user that the beverage is ready for consumption. In normal operation the user will preselect the desired brewing temperature and brewing time using the provided control buttons. The average user will not find it necessary to change either brewing time or temperature very often once he optimizes his preferred operating parameters. However, the controls are sufficiently flexible to allow the user to easily experiment and to change these parameters until the optimum is realized. Some models can memorize and store several different programs found by the user to be optimum for different teas or coffees. It is then a simple matter for the user to select stored programs depending on the special tea or coffee being brewed at a given time. The controls are sufficiently flexible to allow the user if he wishes to defeat the timing function and to control the timing by other means. FIG. 10 is an electrical diagram of the basic operating components. Initially the processor 47 has factory set default values stored for brewing time and temperature. If the user chooses to change brewing time, the time input button 56 is pressed and the display 51 will show the time set. The user can then use the increment button 58 or decrement button 59 to change the default time setting. Similarly, the user may press the brewing temperature-input button 57 and then using the same increment 58 or decrement 59 buttons to change default temperature setting. The processor 47 will store these values for the next use. When the kettle is used again, the modified values will be loaded even if the kettle has been turned off and power removed. The multifunction switch 55 is a user input device which allows the user to select the mode for the kettle to operate. It can of course be several switches. The commonly preferred functions are, but not limited to, OFF, HEAT and BREW. When the multifunction switch 55 is actuated to the “HEAT” position, the processor 47 will activate the heater controller 40 in the following manner: first transistor 42 will be activated which in turn energizes relay 41 to apply full power to heater 19. The processor will then compare output from temperature sensor 27 with set temperature and when sensor 27 output reaches set temperature, the processor 47 will deactivate transistor 42 and relay 41 and activate triac 43 through zero crossing driver 44. This triac 43 is activated and deactivated many times each second in a time based pulse width modulation manner in order to reduce the effective wattage to the heater 19 to only that sufficient to maintain set temperature. With this novel method the minimum time is required to bring the water up to the set temperature by using, for example, full 1500-watts, then more accurate control is utilized to maintain water temperature within a tight tolerance using less wattage. The zero crossing driver 44 senses the location of the AC sine wave voltage and only activates the triac 43 when there is a zero voltage condition thereby reducing inrush current and eliminating radiated interference. While heating in full power mode, LED 53 will be activated by processor 47. When set temperature is reached LED 54 and/or audible signal device 52 will be activated by processor 47. Microprocessor can also activate container release mechanism 35, FIG. 12, thereby lowering container into water or alternately user may lower container manually and switch multifunction switch 55 to “Brew”. At this time, a timer internal to processor 47 will begin counting down from set time and processor 47 will output time remaining to display 51. Also at this time, the processor 47 will command heater controller 40 to reduce wattage further thereby slowly lowering the temperature of the water until it reaches a keep warm temperature suitable for consumption and then maintain that temperature. This temperature has a factory default setting in the processor 47 and can be changed by the user by pressing a combination of buttons. When time reaches “00” the processor will activate LED 60 indicating brew is done and momentarily or periodically activate audible signal device 61. If at any time the steam detector 49 or thermal sensor 27 outputs to processor 47 an electrical signal indicating the presence of steam, the processor 47 will reduce the maximum temperature set point, and thereby reducing water temperature in the future so that no steam is detected. Because this condition may occur at higher altitude locations, this lowered setting will be stored by processor 47 and used for future settings. The processor 47 also analyzes the rate of rise from the temperature sensor 27 and can determine the point of boiling by sensing a significant decrease in the rate of temperature rise, and will likewise reduce settings appropriately. If the user attempts to increment set temperature above this stored temperature, the display 51 will display “Boil”. Pressing a combination of buttons and holding for 3 seconds can restore all factory default settings. If kettle is left unattended with no user input for an extended period such as for 2 hours, processor 47 will deactivate heater controller 40 thereby turning off heater. Any user input will restore normal use. If kettle is operated with no water, processor 47 will determine from sensor 27 that temperature is above normal operation and will deactivate heater. In the event of any component failure which would result in excess temperature of heater 19, boil dry safety switch 50 will interrupt AC power to heater controller 40 thereby deactivating heater 19 until temperature restores to normal. One physical layout of the controls and displays is shown in FIG. 12. As shown in FIG. 1, the controls are in part on the handle of the kettle for convenience and the balance are on the base enclosure 6. In normal use the user preferably preprograms his preferred brewing time and temperature. The processor remembers these settings. In any event the user first programs time and temperature, fills the kettle with water to the desired level and places the correct quantity of coffee or tea inside the brewing container. He will likely not want to immerse the container but rather holds it above the water level while the water heats up to the set temperature level. When that temperature is reached the processor and controller maintain the water in the kettle at the set temperature until the user is ready to start the brewing process. When the user wishes, he then actuates a brewing switch button and lowers the container with the coffee or tea below the water surface to allow the extraction process to begin. Power to the heater is normally turned off at the beginning of the brewing cycle, but as explained later the heating may continue for a limited time. The timer starts counting down and at the end of the preset brewing time an audible alarm and/or light indicates that the brewing time has ended. The user then will likely want to raise the container above the liquid level or remove it completely from the water kettle. The beverage is then ready to serve. Because of the flexibility provided the user can select the optimum time and temperature for brewing. He can elect to either place the container with tea and coffee into the kettle above the water during the heat-up and steaming period to allow the tea or coffee to bloom or he can elect to place the tea and coffee in the container only after the water is at temperature and ready to brew. The user can adjust the amount of tea and coffee used and this novel means allows the user to adjust the effective open-area of the container walls and thereby affect the flow of water in and out of the container during the brewing cycle. During the brewing cycle the user can increase the flow through the container simply by alternately raising and lowering the container within the liquid or in and out of the liquid as the brewing proceeds. If the user wishes to brew at any set temperature but particularly at a temperature at or very close to the local boiling point of water, the processor will direct the controller to apply full or virtually full power to the heater in order to heat the water quickly to that set temperature. Just before the temperature reaches the set temperature the processor will normally direct the controller system to reduce power to a lower level in order to either reduce the opportunity for boiling or to approach the set temperature more slowly and with greater temperature accuracy, thus avoiding temperature overshoot. This insures rapid heat-up and temperature accuracy. If, however the user sets the temperature above the local boiling temperature, a boiling detector or temperature sensor located at the top of the kettle in the steam zone, in the liquid, or otherwise in close thermal contact with the liquid and/or steam alerts the processor to read and record the temperature at which the boiling occurred. Then in the subsequent use the processor and display alerts the user that his setting is above the boiling point and prevents him from setting the temperature above the boiling point. The boiling detector can be, for example a thermistor that senses a leveling off of the rise of liquid temperature of the steam/air mixture, a moisture sensitive resistor or, for example, a thermally sensitive switch based on a thermally sensitive bimetallic material appropriately located to detect the liquid or steam temperature. To sense the leveling of the liquid or vapor temperature rise and hence boiling during the heating cycle one can use an electronic processor that analyzes the rate of rise of the liquid or steam/air and senses the moment that the temperature no longer rises. Electronic means can be incorporated to detect power failures and to switch off the power and to alert the user to restart the unit when power is restored. Any of a variety of audible and/or visual alarms can be used to alert the user to the fact that the water is still heating, that the water temperature is ready to start brewing, or that the brewing cycle is complete. An automated version of this improved brewing means incorporates an electrically actuated “holder” of the container that holds the loaded container above the water level until the water is at the desired brewing temperature. At that temperature the electronic processor directs the electrically actuated holder to release the basket and allows it to drop and immerse into the liquid appropriately. The brewing timer alerts the user when the brewing time is complete to advise him that it is time to raise the container above the liquid, and if desired to remove the container reflecting the fact that the beverage is ready to pour. The electrically actuated “holder” can be an electromagnetically actuated solenoid 37 that moves a rod or lever 35, FIG. 13 to hold and subsequently release the container. Alternatively an electromagnet can be used to attract and hold to it a metal ferromagnetic structural part of the container. FIGS. 15-16 show further embodiments of this invention which are intended to maintain the liquid contents at their desired temperature. As shown in FIG. 15 the kettle 1A includes an outer jacket 80 completely around the vessel 2. The space 82 between the jacket 80 and the vessel 2 is evacuated so as to provide an insulation around the vessel 2. FIG. 16 shows a variation where the kettle 1B has a foam jacket or sleeve 84 disposed around and against the shell vessel 2. The foam sleeve includes electrical wiring 86 which would be connected by wires 88 to processor 47 for heating the sleeve 84 and thereby maintaining the temperature of the liquid within vessel 2. Sleeve 84 could be permanently mounted around vessel 2. Alternatively, the insulation to maintain the temperature of the liquid in vessel 2 could be achieved wherein a sleeve such as sleeve 84 is made of a heat retaining material as is generally known and could be permanently or detachably mounted around vessel 2 without the provision of electrical wiring 86 for heating the sleeve. An important advantage of this new brewing kettle, is that the processor can be programmed to either hold the temperature at the set temperature for a predetermined portion of the brewing time, to heat only until the temperature equilibrates, or to heat for the entire brewing cycle. The actual brewing temperature generally will drop slightly when the container is immersed in the heated water. Clearly it is preferable in any event to use less than full heater power for any heating once the brewing begins in order to avoid any possible overheating of the liquid and the extracted flavorants. By holding the temperature relatively constant during the brewing cycle, the extraction process is optimized, the time can be reduced, and the flavor enhanced. Flavorants, however can be oxidized by direct contact with the heater plate and hence the heater plate must not be excessively hotter than the brewing water. By designing the advanced electric brewing kettle described here with a circular wall configuration it is possible for this advanced brewing means to be used with a separate close fitting flexible screen like those used in a french press that can be alternatively attached to control rod 15 where the coffee/tea container 10 is normally attached By this means the versatility of the product is increased and the need for a separate french press is eliminated for the average household. | <SOH> BACKGROUND OF THE INVENTION <EOH>A wide range of means have been disclosed for the brewing of tea and coffee including percolators, drip methods, and french press. The french press is among the most effective means for extracting the best flavors from tea leaves and ground coffee. The most common french presses are non electric and depend upon preheating the water by conventional means and transferring the hot water to a french press for extraction of the tea leaves or coffee. The electric french press is a similar means to prepare such beverages that boils the water directly in the kettle to insure that the water is at boiling temperature at the start of the brewing cycle. A conventional electric french press type kettle such as described in PCT WO 00/40128 and (PCT/EP99/10357) (DE 19706523A1) is a glass or plastic water vessel with an electric heater plate which is in contact with the water. In such prior art, electrical connection to the kettle and the heater is commonly made through a detachable supporting base that contains an electrical connector which inserts into an electrical socket on the underside of the base enclosure of the kettle. It is common also for the kettle to have a handle on which there is a steam actuated electrical switch that will interrupt all power to the heater plate whenever the water boils and generates steam. However, these conventional brewing devices lack versatility, lack sufficiently precise control of the water temperature during the actual brewing process and have other limitations found to be objectionable by the serious consumer of these beverages. | <SOH> SUMMARY OF THE INVENTION <EOH>This invention is an advanced electric brewing kettle that provides means for adjusting the water temperature precisely to any value for optimum extraction of a wide variety of coffees and teas. The optimum temperatures for extracting green teas is much lower than the black teas. Coffees are generally best extracted at a particular temperature just below the boiling point of water, selected for a favorite coffee and personal tastes. The improved apparatus described here is designed so that the user can operate it either similarly to a French press or as an improved extractor that allows the coffee, tea or other extractable food to be preheated and steamed before the liquid extraction takes place. This invention incorporates an improved means of containing the tea leaves or ground coffee during the extraction and steeping process. By this novel means the contained tea or coffee can be immersed in the water exactly at the optimum brewing temperature and can be removed completely from the water after the precisely optimum steeping or brewing time, thereby stopping abruptly any further extraction. By stopping extraction the more bitter ingredients in the tea leaves or coffee grounds are not extracted and mixed with the more flavorful flavorants already extracted into the water. Further the opportunity for any of the fine grinds from the coffee or tea to remain in the extracted tea or coffee is virtually eliminated—unlike the situation with french presses where the extracted fragments of the tea or coffee remain in the kettle as the beverage is poured. These conventional means aversely affect taste of the beverage and allows unfiltered solids to be poured with the liquid. An added advantage provided by this novel means is that the ground coffee or tea leaves confined within a semi-open container can remain in the kettle above the water level during the time that the water is being heated—thereby allowing the steam to penetrate and swell the tea leaves or ground coffee before they are immersed in the water for extraction. This swelling process or “blooming” allows the extraction time during immersions to be more efficient and shortens the extraction time. Unique, electrical and electric means provide ability to precisely control the extraction time and the extraction temperature, and to adjust operating procedures to adapt to changes in the boiling point due to localized atmospheric pressure especially at higher elevations. | 20040205 | 20071009 | 20060615 | 93328.0 | A47J3140 | 0 | FUQUA, SHAWNTINA T | APPARATUS FOR BREWING BEVERAGES | SMALL | 0 | ACCEPTED | A47J | 2,004 |
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10,774,657 | ACCEPTED | Muscle powered dynamic knee brace | A dynamic knee brace that can be used to apply a bending force across the knee. Two brace arms are connected together by a central joint that allows the knee to pivot. A joint in each brace arm allows the brace arm to be inclined toward the leg. A cam assembly is present to actively incline each brace arms toward the leg as the knee moves to full extension. An adjustment mechanism for the cam assemblies provides control over the maximum amount of inclination each brace arm achieves. Preferably, the adjustment mechanism adjusts the cams equally so that both brace arms are inclined by the same amount. | 1. A dynamic brace comprising: an upper and a lower brace arm; at least one strap securing said brace arms to a leg; a central joint pivotally connecting said brace arms to allow said brace arms to pivot from a flexed to an extended position; a medial/lateral joint in each brace arm proximate to said central joint; two cams disposed between said medial/lateral joints, each said cam having first and second ends, an arcuate cam surface at said first end proximate to one of said medial/lateral joints, and a contact surface at said second end;. said cams positioned so there is a distance between said cam surface and said medial/lateral joint; a stop block proximate to said medial/lateral joint in each brace arm and opposite from said arcuate cam surface, said stop block adapted to contact and slide along a segment of said cam surface, as said brace arms pivot from said flexed to said extended position; wherein each said cam surface is shaped such that as said stop block slides along said segment of said cam surface, said brace arm is dynamically inclined an amount toward said leg; wherein the length of said segment determines said amount said brace arms are dynamically inclined; an adjustment wheel disposed between said contact surfaces of said cams, said wheel adapted to equally adjust said distance of said cams from said medial/lateral joints; wherein said stop blocks slides along a longer segment of said cam surfaces when said cams are closer to said medial/lateral joints. 2. The brace of claim 1 further comprising a wheel in said stop block, wherein said stop block slides along said segment of said arcuate cam surface by said wheel rolling along said segment. 3. The brace of claim 1 wherein said central joint is a geared polycentric joint. 4. The brace of claim 1 wherein each said cam further comprise at least one slot axially aligned between said first and second ends of said cams and wherein pins seat in said slots to allow said distance between said cam surface and said medial/lateral joint to be adjusted. 5. The brace of claim 1 wherein said stop block does not contact said cam surface when said brace arms are in said flexed position. 6. A brace of claim 1 wherein said adjustment wheel comprises a central aperture and two surfaces, each surface contacting said contact surface on one of said cams, wherein said surfaces on said adjustment wheel have an arcuate shape such that, as said adjustment wheel is rotated in a first direction said cams are both equally pushed radially outward toward said medial/lateral joints, and as said adjustment wheel is rotated in a second direction said cams are both equally allowed to move radially inward away from said medial/lateral joints; 7. The brace of claim 6 further comprising: a knob, located in a housing and adapted to rotate said adjustment wheel; an indicator on said knob adapted to line up with index markings on said housing; a cirumference in housing around said knob, said circumference containing regularly spaced detents; at least one resiliently deformable finger protruding from said knob and adapted to seat in any of said plurality of detents. 8. The brace of claim 1 further comprising a shell secured to each brace arm and extending partially around the leg. 9. The brace of claim 8 wherein said shells are integral with said brace arm 10. The brace of claim 1 further comprising at least one pad secured to said brace adapted to contact said leg. 11. The brace of claim 1 further comprising a spring spanning each medial/lateral joint biasing said brace arms to a non-inclined position. 12. A dynamic brace comprising: an upper and a lower brace arm; at least one strap securing each said brace arm to upper and lower portions of a leg; a central joint pivotally connecting said brace arms to allow said brace arms to pivot from a flexed to an extended position; a medial/lateral joint in each brace arm proximate to said central joint; two cams disposed between said medial/lateral joints, each said cam having first and second ends, an arcuate cam surface at said first end proximate to one of said medial/lateral joints, and a contact surface at said second end; said cams positioned so there is a distance between said cam surface and said medial/lateral joint; a stop block proximate to said medial/lateral joint in each said brace arm, opposite from said cam surface; a wheel pivotally connected in said stop block adapted to roll along a segment of said cam surface as said brace arms pivot from said flexed to said extended position; wherein each said cam surface is shaped such that as said wheel rolls along said segment of said cam surface, said brace arm is dynamically inclined an amount toward said leg; wherein the length of said segment determines said amount said brace arms are dynamically inclined as said brace arms reach said extended position; wherein said wheel rolls along a longer segment of said cam surfaces when said cams are closer to said medial/lateral joints; an adjustment wheel disposed between said contact surfaces of said cams; said adjustment wheel comprising a central aperture and two cam surfaces, each surface contacting said contact surface on one of said cams and having an arcuate shape such that as said adjustment wheel is rotated in a first direction, said cams are equally pushed radially outward toward said medial/lateral joints and as said adjustment wheel is rotated in a second direction, said travel cams are equally allowed to move radially inward away from said medial/lateral joints. 13. The brace of claim 12 wherein said central joint is a geared polycentric joint. 14. The brace of claim 13 wherein said cams further comprise at least one slot axially aligned between said first and second ends of said cams and wherein pins seat in said slots to allow said distance between said cam surface and said medial/lateral joint to be adjusted. 15. The brace of claim 14 further comprising: a knob, located in a housing and adapted to rotate said adjustment wheel; an indicator on said knob adapted to line up with index markings on said housing; a circumference in said housing around said knob, said circumference containing regularly spaced detents; at least one resiliently deformable finger protruding from said knob and adapted to seat in any of said plurality of detents. 16. The brace of claim 12 further comprising a shell secured to each brace arm and extending partially around the leg. 17. The brace of claim 16 wherein said shells are integral with said brace arms. 18. The brace of claim 12 further comprising at least one pad secured to said brace adapted to contact said leg. 19. The brace of claim 12 further comprising, a spring spanning each medial/lateral joint biasing said brace arms to a non-inclined position. 20. The brace of claim 12 further comprising: wherein said central joint is a geared polycentric joint; at least one slot axially aligned between said first and second ends of said cams; pins seated in said at least one slot in said cams to allow said distance between said cam surface and said medial/lateral joint to be adjusted; a knob, located in a housing and adapted to rotate said adjustment wheel; an indicator on said knob adapted to line up with index markings on said housing; a circumference in said housing around said knob, said circumference containing regularly spaced detents; at least one resiliently deformable finger protruding from said knob and adapted to seat in any of said plurality of detents; a shell secured to each brace arm and extending partially around the leg; at least one pad secured to said brace and adapted to contact said leg; a spring spanning each medial/lateral joint biasing said brace arms to a non-inclined position. 21. A dynamic brace comprising: an upper and a lower brace arm; at least one strap securing said brace arms to a leg; a central joint pivotally connecting said brace arms such that said brace arms can pivot from a flexed to an extended position; a medial/lateral joint in each said brace arm proximate to said central joint; cam means for dynamically inclining said brace arms an amount toward said leg as said brace arms move to said extended position; adjustment means for adjusting said amount of inclination of each brace arms in said extended position; wherein said amount of inclination is equal for each said brace arm. 22. The brace of claim 21 wherein said cam means equally inclines said brace arms an amount toward said leg. 23. The brace of claim 21 wherein said adjustment means is adjusted to relieve pain associated with unicompartmental osteoarthritis. 24. The brace of claim 21 wherein said cam means comprises: two cams disposed between said medial/lateral joints, each said cam having first and second ends, an arcuate cam surface at said first end facing one of said medial/lateral joints, and a contact surface at said second end; a stop block proximate to the medial/lateral joint in each brace arm, opposite from said cam surface, and adapted to slide along a segment of said cam surface as said brace arms move to said extended position; wherein as said stop block slides along said segment of said cam surface said brace arms are inclined an amount toward said leg. 25. The brace of claim 24 wherein said adjustment means increases said amount of inclination by adjusting said cams such that said stop block slides along a longer segment of said cam surface. 26. The dynamic brace of claim 24 wherein said cam means further comprises a wheel pivotally connected to each said stop block, wherein said stop block slides along said segment by said wheel rolling along said segment. 27. The brace of claim 26 wherein said adjustment means comprises an adjustment wheel disposed between said cams and carries out said adjustment by adjusting the distance between said cams and said medial/lateral joints. 28. The brace of claim 28 wherein said adjustment wheel comprises a central aperture and two cam surfaces, each surface adapted to contact one of said cams such that when said adjustment wheel is rotated, said cams are equally pushed radially outward away from said adjustment wheel or equally allowed to move radially inward toward said adjustment wheel. 29. The brace of claim 24 wherein said central joint comprises a geared polycentric joint. 30. A method of applying a dynamic bending force to a leg comprising: locating a brace around a leg, said brace comprising an upper and a lower brace arm, a central joint positioned at a knee in said leg, said central joint pivotally connecting said brace arms such that said brace arms can pivot from a flexed to an extended position, a medial/lateral joint in each brace arm to allow said brace arm to incline toward the leg; dynamically inclining said brace arms an amount toward said knee as said brace moves from said flexed to said extended position to apply a bending force across said knee; adjusting said amount said brace arms are inclined in said extended position such that said bending force has a desired magnitude; wherein said adjusting step comprises a single adjustment that equally affects said amount of inclination of each brace arm. 31. The method of claim 30 wherein no bending force is applied when said brace arms are in said flexed position. 32. The method of claim 30 wherein said brace comprises cams that perform the dynamically inclining step. 33. A brace adapted for use in the method of claim 30. 34. The method of claim 32 wherein said bending force is used to treat unicompartmental osteoarthritis. 35. The method of claim 34 wherein said desired magnitude is sufficient to completely open a damaged compartment of a knee. 36. The method of claim 32 wherein said brace further comprises a central adjustment wheel that it used to carry out the adjustment step. 37. The method of claim 32 wherein said brace comprises two cams and said adjustment wheel is located between said cams and carries out the adjustment step by adjusting the distance between said cams and said medial/lateral joints. 38. The method of claim 37 wherein said brace further comprises a stop block in each brace arm adapted to contact and slide along a segment of said cam, thereby dynamically inclining said brace arms an amount toward said leg. 39. A brace adapted for use in the method of claim 38. | BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to orthopedic knee braces and, more particularly, to a dynamic knee brace that uses muscle power to apply a bending force across a knee. 2. Description of Related Art Unicompartmental osteoarthritis is a condition where the cartilage on one compartment of the knee has worn away more than the other compartment. This damage to the compartment on one side of the knee causes increased pressure on the damaged compartment, which may be severe enough to be visible as a change in the angulation of the joint. This makes it painful for the patient to engage in activities where there is a load being applied to the knee, such as waking or even standing. Unicompartmental osteoarthritis is generally treated by shifting the load applied across the knee to the compartment that has the least amount of damage, thereby opening the damaged compartment. If there is also a deformity in the knee joint, a high tibial osteotomy can be used to realign the joint and shift the load to the undamaged compartment in the knee. A high tibial osteotomy is a surgical procedure that involves cutting a triangular section off the top of the tibia to realign the joint and open the damaged compartment. After this procedure, it is important to protect the leg to ensure that the bones heal together properly. This is often accomplished by placing the leg in a cast. However, since it is beneficial to allow the knee to pivot during the healing process, a brace can be used to hold the leg in the desired configuration while allowing the knee to freely pivot. If a brace is used after a high tibial osteotomy, the brace arms are often bent to the desired inclination to hold the leg in the desired configuration and provide the necessary support. A knee brace may also be used without surgery, in order to treat unicompartmental osteoarthritis. This is accomplished by providing a bending force across the knee to hold open the damaged compartment of the knee. A three-point bending force is accomplished by having a force applied to the knee on the side opposite from the damaged compartment. This is often done using a strap, a condoyle pad, or other such instrumentality. The force against the knee is countered by two brace arms, which provide static forces against the leg above and below the knee. The brace arms can be bent or otherwise inclined toward the leg using known joints in order to increase the force across the knee. By pulling the knee against the brace arms, the brace applies a three-point bending force at the knee to open the damaged compartment. Alternatively, a four-point bending force can be utilized by applying a force just above and below the knee instead of applying a single force directly to the knee. This avoids applying pressure directly at the knee but creates an equivalent bending moment at the knee as a three-point bending force. A major disadvantage of most braces for treating unicompartmental osteoarthritis is that they provide a static bending force across the knee, which does not change as the knee moves between flexed and extended positions. The pressure in the damaged compartment increases, thereby causing pain, only when weight is being applied to the leg. This occurs close to or at full extension of the knee. The application of force when the knee is partially flexed can make the brace uncomfortable to wear. In addition, when the knee is partially flexed applying a bending force across the knee results in a rotational force that results in a tendency of the brace to rotate around the leg, which lessens its effectiveness. This tendency to rotate increases with the amount of force applied, thereby preventing static force braces from applying the forces required to treat more severe cases of unicompartmental osteoarthritis. Applicant has previously provided a dynamic brace that overcomes this problem, called the Thruster brace, which has been successfully marketed by Medical Technology, Inc. of Grand Prairie, Tex. The Thruster brace only applies the bending force as the knee nears full extension and completely removing it as the knee bends back to a flexed position. It has two brace arms that are connected together by a central polycentric joint that allows the knee to pivot. A hinge in each brace arm allows each brace arm to incline in a medial/lateral direction. Two cams are positioned over the central joint with cam surfaces facing each other and cam followers on the other end of each cam. As the knee moves to extension, the cam surfaces on each assembly contact and roll along each other, and due to the shape of the cams, push the corresponding cam followers away from the central joint. At some point as the knee moves to full extension, the cam followers contact the end of a timing screw extending from an adjustment block located on each brace arm. Further extension of the knee pushes the cam follower further toward the adjustment block, resulting in the brace arm being pushed around the medial/lateral joint toward the leg into a particular degree of inclination. The timing of when the cam follower first contacts the adjustment block, and thus the total amount of inclination that is achieved at full extension, is determined by how far the adjustment screw is threaded through each of the adjustment blocks. While this brace has achieved significant results, there is still opportunity for improvement of dynamic braces. SUMMARY OF THE INVENTION A dynamic knee brace that can be used to apply a bending force across the knee. Two brace arms are connected by a central joint that allows the knee to pivot. A joint in each brace arm allows the brace arm to be inclined in the medial/lateral plane. A cam assembly actively and dynamically inclines each brace arms toward the leg as the knee moves from flexion to full extension. An adjustment mechanism for the cam assemblies provides control over the timing of the dynamic force and thus the maximum amount of inclination each brace arm achieves at full extension. Preferably, the adjustment mechanism adjusts the cams equally so that both brace arms are inclined by the same amount, regardless of the adjustment used. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the present invention is further described and explained in relation to the following figures wherein: FIG. 1 is side elevation view of a preferred embodiment of the current invention in place on a patient's leg with the brace arms in a completely unloaded state; FIG. 2 is a side elevation view of the preferred embodiment of the current invention with all of the straps and pads removed and the shells flattened out for clarity; FIG. 3 is a front elevation view of the preferred embodiment of the current invention in place on a patient's leg and at full extension with the brace arms in a partially loaded state, showing the forces applied to the leg by the brace; FIG. 4a is an expanded and partially cut away view showing the interaction between the adjustment wheel and the travel cams when the brace is completely unloaded and at full extension; FIG. 4b shows the joint depicted in FIG. 4a when the adjustment wheel is adjusted to move the travel cams radially outward, thereby inclining the brace arms; FIG. 4c shows the joint depicted in FIG. 4a when the adjustment wheel is adjusted so that the travel cams are at their maximum distance from each other, thereby providing the maximum amount of inclination of the brace arms; FIG. 5 is an exploded view of the central assembly of the preferred embodiment of the current invention; FIG. 6 is a plan view of the inside of the brace of the preferred embodiment showing the central joint and the medial/lateral joints; FIG. 7 is a bottom plan view of the cover of the joint of the preferred embodiment; FIG. 8 is a top plan view of the adjustment knob of the preferred embodiment; FIG. 9 is a bottom plan view of the adjustment knob of the preferred embodiment; FIG. 10a is a perspective view of the preferred embodiment on a leg and adjusted, with the knee at 105° and the brace arms not inclined; FIG. 10b is a perspective view of the brace in 10a when the knee is extended to 135°; FIG. 10c is a perspective view of the brace in 10a when the knee is extended to 150°; and FIG. 10d is a perspective view of the brace in 10a when the knee is fully extended. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A brace according to a preferred embodiment of the present invention is adapted to be secured around the leg of a patient, use muscle power to provide the required amount of bending force across the knee as the knee moves to full extension, and to dynamically remove the force as the knee flexes. While the following description of the preferred embodiment relates to a brace for treating the medial compartment of the left leg, one of skill in the art would understand any minor alterations required to adapt the preferred embodiment of the current invention for the treatment of the medial or lateral compartment of either knee. With respect to FIGS. 1 and 2, brace 20 is adapted to be located about leg 22 such that joint 24 is next to the compartment of knee 26 that is damaged and needs to be opened. Upper shell 32 is located against leg 22 above knee 26 and lower shell 34 is located against leg 22 below knee 26. Upper shell 32 is secured to media/lateral joint 82 through the use of rivets 194 and lower shell 34 is likewise secured to medial/lateral joint 84. Upper shell 32 is made up of upper brace arm 28 extending up leg 22, wrap 36 that extends around the front of leg 22, and extension 38 that extends down leg 22 toward knee 26 opposite from joint 24. Lower shell 34 is composed of lower brace arm 30 extending down leg 22 and fingers 40 and 42 that extend partially around the front of leg 22. Pads 44 are preferably located on the inside of shells 32 and 34 to provide a more comfortable fit against leg 22. Pads 44 are preferably secured to shells 32 and 34 through the use of a hook and loop fastening system, e.g. Velcro. The hook portion of the fastening system secured to the inside of shells 32 and 34 grip the pile surface of pads 44 that make up the loop portion of the fastening system. Upper shell 32 also has openings 43 through which pads 44 are visible. Openings 43 allow moisture to escape from under shell 32 without weakening the structure of shell 32. Kneepad 80, located on the inside of joint 24, cushions knee 26 and is secured to joint 24 by hook strip 52 on the interior of joint 24. Shells 32 and 34, which include brace arms 28 and 30, are preferably composed of an aluminum alloy that has a significant amount of flex in it. While brace arms 28 and 30 may be completely rigid, it is preferred that there is a degree of flex in them to enhance the thrust that is applied by brace 20 while eliminating point pressure. If, brace arms 28 and 30 are made rigid, it is desirable that some other structure is provided so that shells 32 and 34 lay flat against leg 22 at the points where forces 72 and 74 are applied, in order to avoid the creation of point pressures. Extensions 188 runs along brace arms 28 and 30 help transmit forces along brace arm 28 and 30 so that forces 72 and 74 are applied to leg 22 as shown in FIG. 3. They also enable brace arms 28 and 30 to be made of a thinner material to increase their overall flexibility, while providing the necessary thickness to brace arms 28 and 30 only where necessary to transmit forces along brace arms 28 and 30. Straps 46 and 48 secure lower shell 34 to leg 22. At one end, straps 46 and 48 pass through slots 50 in shell 34 and are secured back upon themselves using Velcro. For strap 48, the other end is secured to pile surfaces 54 on fingers 42 using a Velcro strip. For strap 46, the other end passes through D-ring 64 and is secured back upon itself using Velcro. Web 63 also passes through D-ring 64, is sewn back upon itself and the other end of web 63 is secured to pile surface 54 on finger 40. The use of D-ring 64 on strap 46 allows strap 46 to be adjusted in length to accommodate leg 22 of varying sizes while the use of web 63 allows strap 46 to be quickly released when removing brace 20 from leg 22. Pads 56 are secured on the interior of straps 46 and 48 opposite from shell 34 using hook strips (not shown). In addition, there is elastic section in strap 48 that keeps strap 48 snug while the muscles in leg 22 contract and relax, which changes the circumference of leg 22 to some extent. In cases where the musculature of leg 22 is insufficient to hold brace 20 in place alone, an ankle-foot orthosis, as is well known in the art, can be secured to lower brace arm 30 to help hold brace 20 in the desired position. Strap 60 similarly passes through slot 66 in upper shell 32 and is secured back upon itself using Velcro. The other end of strap 60 is secured to pile surface 54 at the end of wrap 36 on upper shell 32, also using Velcro. Strap 60 also has an elastic similar to strap 48. Pad 56 is secured to the inside of strap 60 opposite from upper shell 32 using Velcro. One end of strap 62 passes through D-ring 64 and is sewn back upon itself. Strap 62 then passes through slot 68 in upper shell 32, behind upper brace arm 28 and back out slot 70. Strap 62 then passes behind leg 22, around extension 38 and back around leg 22 to pass through D-ring 64 and be secured back upon itself in front of leg 22 using Velcro. Pad 56 is secured on the inside of strap 64, behind leg 22 and between upper brace arm 28 and extension 38. There is also hook strip 52 secured to the bottom of extension 38 that secures to the pile surface of strap 64 and holds it in the desired location. As can be seen in FIG. 3, when joint 24 is adjusted to generate a bending force and knee 26 is at or near full extension, a bending force is created across knee 26. As can be better seen in FIG. 10d, joint 24 inclines both upper brace arm 28 and lower brace arm 30 an angle θ from vertical as knee 26 moves from flexion to full extension. As a result, upper brace arm 28 and lower brace arm apply forces 72 and 74 respectively to leg 22. On the other side, the bottom end of extension 38, aided by strap 62, applies force 76 to leg 22 and strap 46 applies force 78 to leg 22. Forces 76 and 78 on one side combine with forces 72 and 74 on the other side to create a four-point bending force across knee 26 that shifts the compressive force passing through knee 26, to the compartment of the knee that is further away from joint 24, thereby relieving pressure passing through, and in some cases opening, the damaged compartment of knee 26. It is recognized that due to the flexible nature of the shells 32 and 34, brace arms 28 and 30 will not remain straight and thus will not take on a defined angle of inclination. Rather brace arms 28 and 30 will flex such that while the inclination of the portion of brace arms: 28 and 30 will change to some extent, the remainder of brace arms 28 and 30 will flex such that shell 32 and 34 remain flat against leg 22 so that no point pressures develop. Use of the term “inclination” in connection with this invention is intended to also encompass this situation where the brace arms are rotated around the medial/lateral joints toward the leg but there is no defined angle of inclination of the brace arm due to the flexibility of brace arms 28 and 30. With respect to FIG. 4, joint 24 is generally composed of medial/lateral joints 82 and 84 in brace arms 28 and 30 respectively, central joint 86, adjustment wheel 92 positioned over central joint 86, travel cams 88 and 90 that extend from adjustment wheel 92 toward medial/lateral joints 82 and 84 respectively, and stop blocks 98 and 100. Wheels 94 and 96 are pivotally secured in stop blocks 98 and 100, which are adjacent to medial/lateral joints 82 and 84. Wheels 94 and 96 also project over medial/lateral joints 82 and 84 toward central joint 86. Cams 88 and 90 have cam surfaces 102 and 104 on their edge closest to wheels 94 and 96. Cam surfaces 102 and 104 are each an arcuate surface with an increasing radius from one end to the other. As knee 24 moves to full extension, at some point roller wheels 94 and 96 contact cam surfaces 102 and 104 respectively and roll along cam surfaces 102 and 104 until they reach the position depicted in FIGS. 4a-c. Wheels 94 and 96 are pivotally connected to stop blocks 98 and 100 and are adapted to roll along cam surfaces 102 and 104 to provide a smoother motion than if stop blocks 98 and 100 simply slid along cam surfaces 102 and 104. Cam surfaces 102 and 104 have an arcuate curve such that the radial distance from cam surface 102 and 104 to contact surface 120 gets progressively larger from one end of cain surfaces 102 and 104 to the other. As knee 26 moves to full extension, roller wheels 94 and 96 roll along a segment of cam surfaces 102 and 104 and the increasing distance of cam surfaces 102 and 104 from shoulder 120 push roller wheels 94 and 96 further away from central joint 86. As can be seen in FIGS. 10a-d, this has the effect of pushing brace arms 28 and 30 around medial/lateral joints 82 and 84 toward leg 22 an angle θ. Brace arms 28 and 30 reach a maximum degree of inclination toward leg 22 when knee 26 is fully extended. FIG. 4b depicts joint 24 as shown in FIG. 4a after adjustment wheel 92 has been partially adjusted to increase the bending force of brace 20 at full extension and shell 34 is inclined to an angle Φ which is less than 180°. FIG. 4c depicts joint 24 shown in FIGS. 4a and 5 but where adjustment wheel 92 has been adjusted to its maximum amount as shown by angle Φ which is less than angle Φ in FIG. 4b. In each figure, adjustment wheel 92 has been rotated clockwise to some extent so contact surfaces 120 on cams 88 and 90 are pushed further away from each other. This holds cam surfaces 102 and 104 closer to medial/lateral joints 82 and 84 respectively. As a result, wheels 94 and 96 contact cam surfaces 102 and 104 earlier as knee 26 moves to full extension and roll along a larger portion of cam surfaces 102 and 104. Consequently, brace arms 28 and 30 begin inclining toward leg 22 earlier as knee 26 extends and have a larger degree of inclination toward leg 22 at full extension than before adjustment wheel 92 was adjusted. Due to the symmetrical shape of adjustment wheel 92, cams 88 and 90 are always adjusted the same amount, which ensures that the bending force across the knee is even and patient discomfort due to an improperly adjusted brace 20 is minimized. However, adjustment wheel 92 may be asymmetrical if for some reason it is desirable that more force is applied by one of brace arms 28 and 30. As shown in FIG. 5, joint 24 is composed of many components. Base 106 is oval in shape and has a central opening 108 that knob 110 protrudes through and six holes 112 with three on each side of central opening 108 arranged in a triangular fashion. Base 106 also has notches 114 at either end of its central transverse axis. Pins 116 are seated in holes 112, have a hollow center, and extend from base 106. Bushings 118 are positioned over pins 116. Travel cams 88 and 90 are mirror images of each other and contain cam surfaces 102 and 104, contact surface 120, shoulder 122, and three slots 124. Pins 116 with bushings 118 fit in slots 124 of travel cam 88 and 90 to restrict travel cams 88 and 90 to a single linear motion. This keeps travel cams 88 and 90 properly aligned during use and adjustment of brace 20. Adjustment wheel 92 fits between travel cams 88 and 90 and is made of two arcuate surfaces 126 and 128 around a central hole 136. Each arcuate surface 126 and 128 is a cam surface in the shape of a circle whose radius gets larger as you move along the surface. Shoulders 132 join arcuate surface 126 and 128 together where the radius of one arcuate surface is largest and the radius of the adjacent arcuate surface is at its smallest. Adjustment wheel 92 has 180° rotational symmetry so that for all diameters of adjustment wheel 92, arcuate surfaces 126 and 128 are equidistant from the center of star cam 92. This ensures that travel cams 88 and 90 are the same distance from the center of adjustment wheel 92, regardless of its rotational position. Knob 110 engages adjustment wheel 92 through central hole 130. Central hole 130 is in the shape of a square with a corner cut off to allow knob 110 to engage central hole 130 and rotate adjustment wheel 92 while ensuring that knob 110 is installed in the correct orientation. Contact surfaces 120 of travel cams 88 and 90 seat on arcuate surfaces 126 and 128 respectively of adjustment wheel 92. As can be seen in FIG. 4a-c, as adjustment wheel 92 is rotated, the portion of arcuate surfaces 126 and 128 that abut against contact surfaces 120 becomes further away from the center of adjustment wheel 92. This results in travel cams being pushed further away from the center of adjustment wheel 92 in the only direction that slots 124 allow. This pushes cam surfaces 102 and 104 closer toward medial/lateral joints 82 and 84 respectively. Shoulders 132 on adjustment wheel 92 contact shoulders 122 on both travel cams to prevent adjustment wheel 92 from rotating directly from arcuate surfaces 126 and 128 being at their closest to the center of adjustment wheel 92 to being at their furthest distance. Spacer plate 134 is oval in shape, has a shorter longitudinal axis than base 106, and has six holes 112 that seat over pins 116 and bushings 118. Spacer plate 134, along with base 106 ensures that adjustment wheel 92 and travel cams 88 and 90 all remain in the same plane. Spacer plate 134 also has notches 114 at either end of its transverse axis that are aligned with notches 114 in base 106, central hole 136 aligned with central opening 108 in base 106, and offset holes 138 along the longitudinal axis of spacer plate 134 on either side of central hole 136. Central hole 136 allows the end of knob 110 to pass through spacer plate 134. On top of spacer plate 134 is inner plate 140. Inner plate 140 is also the same size and shape as spacer plate 134. It has six holes 142 that are aligned with holes 112 of spacer plate 134. However, holes 142 are only large enough for pins 116 so inner plate 140 rests on the top of bushings 118. Inner plate has hubs 144 located along its longitudinal axis and on either side of central hole 136. Hubs 144 extend above and slightly below inner plate. 140 and seat within offset holes 138 of spacer plate 134. Hubs 144 also are internally threaded. Inner plate 140 has holes 148 that line up with notches 114 on spacer plate 134 and base 106. The end of hollow pins 116 is bent radially outward and back against the surface of inner plate 140, which keeps pins 116 from falling out of joint 24. A second spacer plate 150 that is identical to spacer plate 134 is located on the other side of inner plate 140. Offset holes 138 in spacer plate 150 seats over hubs 144 and holes 112 seat over the ends of pins 116 that have been bent radially outward. Central joint 86 is located on top of second spacer plate 150. Central joint 86 is preferably in the form of a geared polycentric joint, although one of skill in the art will understand that the many other types of joints capable of allowing the knee joint to pivot may be used instead. Central joint 86 is made up of hinge member 152 and hinge member 154. Hinge members 152 and 154 each have opening 156, which allows hubs 144 to pivotally connect hinge members 152 and 154 to the rest of joint 24. As can be better seen in FIG. 6, hinge member 152 is connected to medial/lateral joint 82 using rivets 166 through holes 168 and hinge member 154 is likewise connected to medial/lateral joint 84. Gear teeth 162 and 164 on hinge members 152 and 154, respectively, mesh together to ensure that hinge members 152 and 154 rotate together. Hinge members 152 and 154 also both have shoulders 158 and 160 that define the limits of rotation of hinge members 152 and 154 around hubs 144 and ultimately the flexion and extension limits of knee 26. Shoulders 158 on hinge members 152 and 154 abut each other to prevent central hinge 86 from rotating beyond the full extension of knee 26. Similarly, shoulders 160 on hinge members 152 and 154 abut each other to provide a limit to the rotation of central joint 86 in the other direction that does not prevent knee 26 from achieving a fully flexed position. Thus shoulders 158 and 160 allow knee 26 to undergo its full range of motion while helping to ensure that gear teeth 162 and 164 on hinge members 152 and 154 remain engaged. Shoulders 158 and 160 can also be positioned to restrict the range of motion of knee 26 as desired. Plate 170 is seated on top of hinge members 152 and 154 so that they do not come off hubs 144. Plate 170 is the same shape as spacer plates 134 and 150 and also contains notches 114. Plate 170 contains offset holes 172 along its longitudinal axis that are smaller than and line up with hubs 144. Screws 174 pass through offset holes 172 and thread into inner thread section 146 in hubs 144 to hold plate 170 and hinge members 152 and 154 to inner plate 140 and the rest of joint 24. As seen in FIG. 6, hook strip 52 is located on the side of plate 170 opposite from joint 24 to secure kneepad 80 to the inside of joint 24. Housing 190 is placed over base 106 and around joint 24. Screws are used to secure inner plate 140 to housing 190 through holes 148, notches 114 in 'spacer plate 134 and base 106 and into posts 196 in housing 190. As can be more clearly seen in FIG. 9, housing 190 has a central hole 198 in its center for knob 110. Around the edge of central hole 198 is channel 200 that holds knob 110 in joint 24. Regularly spaced around rim 200 are notches 202. Notches 202 do not extend entirely around channel 200 but are divided into two sections by posts 196. In addition, groove 204 runs along slightly less than halfway around channel 200. As can be more clearly seen in FIGS. 8 and 9, knob 110 has rim 206 that can seat in channel 200 of housing 190. There is also a projection 208 on the top of rim 206 that seats in groove 204. In this manner, projection 208 keeps knob 110 in a defined range so that star cam 92 is not rotated so far that contact surface 120 on travel cams 88 and 90 go off the end of shoulders 132 on star cam 92. Knob 110 also has fingers 210 that are resiliently biased to extend beyond the radius of rim 206 but are selectively deformable to compress within the radius of rim 206. Fingers 210 seat in notches 202 located in channel 200. As knob 110 is turned, fingers 210 are pushed radially inward by the wall of channel 200 and spring back to their original position in the next notch 202. This allows knob 110 to be moved, and correspondingly joint 24 to be adjusted, in discrete increments that can both be heard as well as felt by the person making the adjustment. In addition, it allows pointer 211 on knob 110 to line up with markings (not shown) on the top of housing 190 so that the adjustment position of the brace can be quickly determined. The lack of notches 202 by posts 196 also help to keep knob 110 in the desired range. As shown with respect to FIG. 10, the back of knob 110 has a central column 212 that extends into joint 24. Cylinder 214 seats in central opening 108 in base 106 and allows knob 110 to freely rotate. Block 216 seats in central hole 130 of adjustment wheel 92. Block 216 is square in shape with one corner rounded off. The straight sides of block 216 allows knob 110 to rotate adjustment wheel 92 along with it while the curved corner ensures that knob 110 is seated in the desired orientation. With respect to FIG. 6, brace arms 28 and 30 are connected to joint 24 by medial/lateral joints 82 and 84 respectively. Medial/lateral joints 82 and 84 are simple wrap hinges composed of two hinge wraps 176 and 178 joined by a hinge pin. Springs 182 are secured to hinge member 152 and 154 by rivets 166 that are also used to secure hinge member 152 and 154 to hinge wraps 178 of medial/lateral joints 88 and 90. Similarly, push blocks 98 and 100 are secured to brace arms 88 and 90 respectively using rivets 194 that also secure brace arms 88 and 90 to hinge wrap 178 of medial/lateral joints 88 and 90. Wheels 94 and 96 are pivotally connected to push blocks 98 and 100, respectively, and cover 184 secured over frame 182 and to brace arms 88 and 90 by rivets 194. Springs 182 are not required for brace 20 to function, but are included in order to keep brace arms 28 and 30 from flopping too much, especially while the brace is being applied. This makes brace 20 appear less flimsy and more appealing to the patient. Medial/lateral joints 82 and 84 allow brace arms 28 and 30 to freely incline in both the medial and lateral directions. The travel cams 88 and 90 only restrict the inclination of brace arms 28 and 30 in a single direction, which is away from the leg when the brace is being worn. When adjusted to the lowest setting, as would be done when applying the brace, travel cams 88 and 90 restrict the movement of brace arms 28 and 30 to the least extent, providing the largest range of motion for brace arms 28 and 30 to flop around without any control over their inclination. However, this freedom of movement of brace arms 28 and 30 does not interfere with the function of the brace. As knee 26 moves to full extension, joint 24 pushes brace arms 28 and 30 against leg 22, preventing movement in the medial/lateral plane in the direction away from leg 22. It is contemplated that brace 20 can be used in the following manner. The appropriate brace 20 is selected so that joint 24 is next to the damaged compartment of knee 26 that needs to be opened, which in this case is the left medial compartment. If desired, an undersleeve (not shown) may be placed on the leg to reduce slippage between brace 20 and leg 22. Joint 24 should be adjusted to its lowest setting so that brace arms 28 and 30 are not inclined at all when brace 20 is fully extended. This is accomplished by turning knob 111 clockwise until shoulders 132 on star cam 92 contact shoulders 122 on travel cams 88 and 90. The ends of straps 46, 48, 60, and 62 are removed from brace 20 and strap 62 is removed from D-ring 64 so that the front of brace 20 is open. In a seated position with the knee at approximately a 90° angle, brace arms 28 and 30 are placed against leg 22 with joint 24 lined up with knee 26. The center of kneepad 80 should be aligned over the adductor tubercle on the inside of knee 26. Strap 46 is passed behind leg 22 and the end of web 63 is secured to pile surface 54 on finger 40. The other end of strap 46 is then removed and repositioned on strap 46 while applying tension to provide a secure fit around leg 22. Strap 46 should be snug but not so tight as to cause discomfort or affect circulation. After strap 46 is adjusted, it can be removed and reattached just by using the connection between web 63 and pile surface 54 on finger 40, thereby avoiding the need for adjustments every time the brace is applied. Next, strap 48 is passed behind leg 22 and the end of strap 48 is secured to pile surface 54 on finger 42. If adjustment to the length of strap 48 is required, the back end of strap 48 can be removed from itself and reattached to strap 48 in the desired location so that strap 48 is the desired length and fits leg 22 snugly. Similarly, after strap 48 has been adjusted, it can be removed and reattached by using the connection between the end of strap 48 and pile surface 54 on finger 42. Then strap 62 is passed behind leg 22. While manually pushing bottom of extension 38 against leg 22, strap 62 is secured onto hook strip 52 on the bottom of extension 38. Then the free end of strap 62 is passed through D-ring 64, tensioned, and secured back onto strap 62 in front of leg 22. Strap 60 is then passed around the back of leg 22 and the end of strap 60 is secured to pile surface 54 on wrap 36. If the length of strap 60 needs to be adjusted, then the rear end of strap 60 can be released from itself by slot 66 and readjusted to shorten or lengthen strap 60 as required. After adjusting strap 60, it can be removed and reattached by using the connection between the free end of strap 60 and pile surface 54 on wrap 36. At this point, the patient should get up and walk around to ensure that brace 20 is comfortable and that there is no pinching or binding. If any adjustments need to be made, it is preferred that they also are made in the seated with knee 26 flexed at about 80-90°. When brace 20 is properly located on leg 22, and while still in a seated position with the knee flexed at 80-90°, joint 24 is adjusted to generate the required bending force to provide the desired level of pain relief. Knob 110 should be adjusted counterclockwise one or two notches. As knob 110 is adjusted, fingers 210 will snap into successive notches 202. This allows joint 24 to be adjusted in discrete intervals. In addition, the movement of fingers 210 between notches 202 can be felt as well as produces an audible click in order to make it easy to keep track of the amount of adjustment that has been made. After adjusting knob 110 so that fingers 210 move over one or two notches 202, the patient should stand up and walk around to quantify the pain relief. If more unloading is required to obtain pain relief, then the patient should sit back down and adjust knob 110 so fingers 210 move around another one or two notches 202 around channel 200. If too much unloading is provided, brace 20 will become uncomfortable. Joint 24 should be adjusted to a point that maximizes the unloading the damaged compartment of knee 26 while minimizing any discomfort created by brace 20. Joint 24 should only be adjusted in an unloaded position with knee 26 bent enough so that roller wheels 94 and 96 do not contact cam surfaces 102 and 104. This can be assured by only adjusting the brace while in the seated position and with knee 26 at an approximately 90° angle. The above descriptions of certain embodiments are made for the purposes of illustration only and are not intended to be limiting in any manner. Other alterations and modifications of the preferred embodiment will become apparent to those of ordinary skill in the art upon reading this disclosure, and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventor is legally entitled. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates generally to orthopedic knee braces and, more particularly, to a dynamic knee brace that uses muscle power to apply a bending force across a knee. 2. Description of Related Art Unicompartmental osteoarthritis is a condition where the cartilage on one compartment of the knee has worn away more than the other compartment. This damage to the compartment on one side of the knee causes increased pressure on the damaged compartment, which may be severe enough to be visible as a change in the angulation of the joint. This makes it painful for the patient to engage in activities where there is a load being applied to the knee, such as waking or even standing. Unicompartmental osteoarthritis is generally treated by shifting the load applied across the knee to the compartment that has the least amount of damage, thereby opening the damaged compartment. If there is also a deformity in the knee joint, a high tibial osteotomy can be used to realign the joint and shift the load to the undamaged compartment in the knee. A high tibial osteotomy is a surgical procedure that involves cutting a triangular section off the top of the tibia to realign the joint and open the damaged compartment. After this procedure, it is important to protect the leg to ensure that the bones heal together properly. This is often accomplished by placing the leg in a cast. However, since it is beneficial to allow the knee to pivot during the healing process, a brace can be used to hold the leg in the desired configuration while allowing the knee to freely pivot. If a brace is used after a high tibial osteotomy, the brace arms are often bent to the desired inclination to hold the leg in the desired configuration and provide the necessary support. A knee brace may also be used without surgery, in order to treat unicompartmental osteoarthritis. This is accomplished by providing a bending force across the knee to hold open the damaged compartment of the knee. A three-point bending force is accomplished by having a force applied to the knee on the side opposite from the damaged compartment. This is often done using a strap, a condoyle pad, or other such instrumentality. The force against the knee is countered by two brace arms, which provide static forces against the leg above and below the knee. The brace arms can be bent or otherwise inclined toward the leg using known joints in order to increase the force across the knee. By pulling the knee against the brace arms, the brace applies a three-point bending force at the knee to open the damaged compartment. Alternatively, a four-point bending force can be utilized by applying a force just above and below the knee instead of applying a single force directly to the knee. This avoids applying pressure directly at the knee but creates an equivalent bending moment at the knee as a three-point bending force. A major disadvantage of most braces for treating unicompartmental osteoarthritis is that they provide a static bending force across the knee, which does not change as the knee moves between flexed and extended positions. The pressure in the damaged compartment increases, thereby causing pain, only when weight is being applied to the leg. This occurs close to or at full extension of the knee. The application of force when the knee is partially flexed can make the brace uncomfortable to wear. In addition, when the knee is partially flexed applying a bending force across the knee results in a rotational force that results in a tendency of the brace to rotate around the leg, which lessens its effectiveness. This tendency to rotate increases with the amount of force applied, thereby preventing static force braces from applying the forces required to treat more severe cases of unicompartmental osteoarthritis. Applicant has previously provided a dynamic brace that overcomes this problem, called the Thruster brace, which has been successfully marketed by Medical Technology, Inc. of Grand Prairie, Tex. The Thruster brace only applies the bending force as the knee nears full extension and completely removing it as the knee bends back to a flexed position. It has two brace arms that are connected together by a central polycentric joint that allows the knee to pivot. A hinge in each brace arm allows each brace arm to incline in a medial/lateral direction. Two cams are positioned over the central joint with cam surfaces facing each other and cam followers on the other end of each cam. As the knee moves to extension, the cam surfaces on each assembly contact and roll along each other, and due to the shape of the cams, push the corresponding cam followers away from the central joint. At some point as the knee moves to full extension, the cam followers contact the end of a timing screw extending from an adjustment block located on each brace arm. Further extension of the knee pushes the cam follower further toward the adjustment block, resulting in the brace arm being pushed around the medial/lateral joint toward the leg into a particular degree of inclination. The timing of when the cam follower first contacts the adjustment block, and thus the total amount of inclination that is achieved at full extension, is determined by how far the adjustment screw is threaded through each of the adjustment blocks. While this brace has achieved significant results, there is still opportunity for improvement of dynamic braces. | <SOH> SUMMARY OF THE INVENTION <EOH>A dynamic knee brace that can be used to apply a bending force across the knee. Two brace arms are connected by a central joint that allows the knee to pivot. A joint in each brace arm allows the brace arm to be inclined in the medial/lateral plane. A cam assembly actively and dynamically inclines each brace arms toward the leg as the knee moves from flexion to full extension. An adjustment mechanism for the cam assemblies provides control over the timing of the dynamic force and thus the maximum amount of inclination each brace arm achieves at full extension. Preferably, the adjustment mechanism adjusts the cams equally so that both brace arms are inclined by the same amount, regardless of the adjustment used. | 20040205 | 20090310 | 20050811 | 95638.0 | 1 | LEWIS, KIM M | MUSCLE POWERED DYNAMIC KNEE BRACE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,774,663 | ACCEPTED | Support bracket for an inflatable curtain | An apparatus (10) helps to protect an occupant of a vehicle (12) that has a roof (18), a side structure (16), and a trim piece (220) overlying the side structure. The apparatus (10) includes an inflatable curtain (14) inflatable away from the roof (18) to a position adjacent the side structure (16). An inflation fluid source (24) provides inflation fluid for inflating the inflatable curtain (14). A fill tube (22) directs inflation fluid from the inflation fluid source (24) into the inflatable curtain (14). A bracket (120) connects the fill tube (22) to the vehicle (12). The bracket (120) includes a fill tube support portion (140) connectable with the fill tube (22). A connecting portion (130) is connectable with the vehicle (12). A deployment portion (150) directs the inflatable curtain (14) to deploy inboard of the trim piece (220). | 1. An apparatus for helping to protect an occupant of a vehicle that has a roof, a side structure, and a trim piece overlying the side structure, said apparatus comprising: an inflatable curtain that is inflatable away from the vehicle roof to a position adjacent the side structure of the vehicle; an inflation fluid source for providing inflation fluid for inflating said inflatable curtain; a fill tube for directing inflation fluid from said inflation fluid source into said inflatable curtain; and a bracket for connecting said fill tube to the vehicle, said bracket comprising: a fill tube support portion connectable with said fill tube; a connecting portion connectable with the vehicle; and a deployment portion for directing said inflatable curtain to deploy inboard of the trim piece. 2. The apparatus recited in claim 1, wherein said fill tube support portion has a curved configuration with first and second opposite ends, said connecting portion extending transversely from said first end of said clamping portion, said deployment portion extending transversely from said second end of said clamping portion. 3. The apparatus recited in claim 1, wherein said fill tube support portion at least partially encircles a portion of said fill tube to connect said bracket to said fill tube. 4. The apparatus recited in claim 1, wherein said fill tube support portion has an inner surface with a cylindrical portion that mates with a cylindrical outer surface of said fill tube. 5. The apparatus recited in claim 1, wherein said fill tube support portion includes a tab portion deformable into engagement with said fill tube to help connect said fill tube support portion to said fill tube. 6. The apparatus recited in claim 1, wherein said deployment portion extends away from the side structure when the bracket is connected to the vehicle. 7. The apparatus recited in claim 1, wherein said deployment portion defines a concave channel for receiving said inflatable curtain in a deflated and stored condition. 8. The apparatus recited in claim 1, wherein said inflatable curtain includes apertures that expose portions of said fill tube, said fill tube support portion connecting with said exposed portions of said fill tube. 9. The apparatus recited in claim 1, further comprising a fabric sheath for at least partially surrounding said inflatable curtain in a stored condition, said inflatable curtain when in said stored condition being is at least one of folded and rolled into a position extending along an intersection of the side structure of the vehicle and the vehicle roof. 10. The apparatus recited in claim 1, wherein said deployment portion comprises a first portion that extends along the side structure of the vehicle away from the vehicle roof and a second portion that extends transverse to said first portion away from the side structure and inboard in the vehicle. 11. The apparatus recited in claim 1, wherein said bracket has a length, said deployment portion extending substantially along the length of said bracket, said fill tube support portion comprising a plurality of supports spaced along the length of said bracket, said connecting portion comprising a plurality of flanges spaced along the length of said bracket. 12. The apparatus recited in claim 1, wherein said deployment portion extends below said inflatable curtain when said inflatable curtain is in a stored and deflated condition. 13. A bracket for supporting a fill tube and an inflatable curtain adjacent a trim piece in a vehicle, said bracket comprising: a fill tube support portion connectable with the fill tube; a connecting portion connectable with the vehicle; and a deployment portion for directing said inflatable curtain to deploy inboard of the trim piece. 14. The bracket recited in claim 13, wherein said fill tube support portion has a curved configuration with first and second opposite ends, said connecting portion extending transversely from said first end of said clamping portion, said deployment portion extending transversely from said second end of said clamping portion. 15. The bracket recited in claim 13, wherein said fill tube support portion includes a tab portion deformable into engagement with said fill tube to help connect said fill tube support portion to said fill tube. 16. The bracket recited in claim 13, wherein said deployment portion defines a concave channel for receiving said inflatable curtain in a deflated and stored condition. 17. The bracket recited in claim 13, wherein said deployment portion extends below the inflatable curtain when the inflatable curtain is in a stored and deflated condition. 18. An apparatus for helping to protect an occupant of a vehicle that has a roof, a side structure, and a trim piece overlying the side structure, said apparatus comprising: an inflatable curtain that is inflatable away from the vehicle roof to a position adjacent the side structure of the vehicle; an inflation fluid source for providing inflation fluid for inflating said inflatable curtain; a fill tube for directing inflation fluid from said inflation fluid source into said inflatable curtain; and a bracket for connecting said fill tube to the vehicle and for directing said inflatable curtain to deploy inboard of the trim piece. | FIELD OF THE INVENTION The present invention relates to an inflatable apparatus for helping to protect a vehicle occupant in the event of a side impact to the vehicle and/or a vehicle rollover. BACKGROUND OF THE INVENTION It is known to inflate an inflatable vehicle occupant protection device to help protect a vehicle occupant. One particular type of inflatable vehicle occupant protection device is an inflatable curtain. The inflatable curtain is inflatable away from the roof of the vehicle between a vehicle occupant and the side structure of the vehicle in response to a side impact to the vehicle and/or a vehicle rollover. A known inflatable curtain is inflated from a deflated condition with inflation fluid directed from an inflator to the inflatable curtain. SUMMARY OF THE INVENTION The present invention relates to an apparatus for helping to protect an occupant of a vehicle that has a roof, a side structure, and a trim piece overlying the side structure. The apparatus includes an inflatable curtain inflatable away from the roof to a position adjacent the side structure. An inflation fluid source provides inflation fluid for inflating the inflatable curtain. A fill tube directs inflation fluid from the inflation fluid source into the inflatable curtain. A bracket connects the fill tube to the vehicle. The bracket includes a fill tube support portion connectable with the fill tube. A connecting portion is connectable with the vehicle. A deployment portion directs the inflatable curtain to deploy inboard of the trim piece. The present invention also relates to an apparatus for helping to protect an occupant of a vehicle that has a roof, a side structure, and a trim piece overlying the side structure. The apparatus includes an inflatable curtain that is inflatable away from the vehicle roof to a position adjacent the side structure of the vehicle. An inflation fluid source provides inflation fluid for inflating said inflatable curtain. A fill tube directs inflation fluid from the inflation fluid source into the inflatable curtain. A bracket connects the fill tube to the vehicle and directs the inflatable curtain to deploy inboard of the trim piece. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon consideration of the following description of the invention with reference to the accompanying drawings, in which: FIG. 1 is a schematic view of an apparatus for helping to protect a vehicle occupant illustrating the apparatus in a deflated and stored condition in a vehicle, according to a first embodiment of the present invention; FIG. 2 is a schematic view of the apparatus of FIG. 1 in an inflated condition in the vehicle; FIG. 3 is a sectional view taken generally along line 3-3 in FIG. 2; FIG. 4 is a sectional view taken generally along line 4-4 in FIG. 1; FIG. 5 is a sectional view taken generally along line 5-5 in FIG. 2; FIGS. 6A and 6B are perspective views of a portion of the apparatus of FIGS. 1-5; and FIGS. 7A and 7B are perspective views of a portion of the apparatus of FIGS. 1-5, according to a second embodiment of the present invention. DESCRIPTION OF AN EMBODIMENT Representative of the present invention, an apparatus 10 helps to protect an occupant of a vehicle 12. As shown in FIGS. 1 and 2, the apparatus 10 includes an inflatable vehicle occupant protection device in the form of an inflatable curtain 14 that is mounted adjacent the side structure 16 of the vehicle 12 and the roof 18 of the vehicle. The side structure 16 of the vehicle 12 includes an A pillar 30, a B pillar 32, a C pillar 34, and front and rear side windows 40 and 42. The vehicle 12 also includes front vehicle seating 44 positioned adjacent the front side window 40 and rear vehicle seating 46 positioned adjacent the rear side window 42. An inflator 24 is connected in fluid communication with the inflatable curtain 14 through a fill tube 22. The fill tube 22 may be constructed of any suitable material, such as metal or plastic. The fill tube 22 has a first end portion 36 for receiving fluid from the inflator 24. The fill tube 22 may be connected directly to the inflator 24 or a manifold (not shown) may connect the fill tube to the inflator. The fill tube 22 has a second end portion 38 disposed in the inflatable curtain 14. The inflator 24 contains a stored quantity of pressurized inflation fluid (not shown) in the form of a gas for inflating the inflatable curtain 14. The inflator 24 alternatively could contain a combination of pressurized inflation fluid and ignitable material for heating the inflation fluid, or could be a pyrotechnic inflator that uses the combustion of gas-generating material to generate inflation fluid. As a further alternative, the inflator 24 could be of any suitable type or construction for supplying a medium for inflating the inflatable curtain 14. The apparatus 10 may include a cover 26 (FIG. 1), such as a fabric sheath or plastic housing, that helps support the inflatable curtain 14 in a stored and deflated condition. The deflated inflatable curtain 14 and the cover 26 have an elongated configuration and extend along the vehicle roof 18 and along the side structure 16 of the vehicle 12 above the side windows 40 and 42. The fill tube 22, inflatable curtain 14 and cover 26 are connected to the vehicle 12 by brackets 120. The inflatable curtain 14 (FIG. 3) includes panels 50 and 52 of material that are arranged in an overlying manner. Overlapping portions of the panels 50 and 52 are interconnected along at least a portion of a perimeter 54 of the inflatable curtain 14 to form a perimeter connection 56 of the curtain. The perimeter connection 56 helps define an inflatable volume of the inflatable curtain 14. The inflatable curtain 14 may also include interior connections (not shown) in which the overlying panels 50 and 52 are interconnected within the perimeter 54 to form non-inflatable portions that help define inflatable chambers of the curtain. The inflatable curtain 14 may be formed in a variety of manners, such as by interweaving the overlying panels 50 and 52, stitching the panels together, or interconnecting the panels via ultrasonic welding, heat bonding, or adhesives. In a woven construction, the overlying panels 50 and 52 may be woven/interwoven simultaneously from a material, such as nylon yarn, and may be coated with a gas impermeable material, such as urethane, or laminated with a gas impermeable film. The inflatable curtain 14 thus may have a substantially gas-tight construction. Those skilled in the art will appreciate that alternative materials, such as polyester yarn, and alternatives coatings, such as silicone, may also be used to construct the inflatable curtain 14. The perimeter 54 of the inflatable curtain 14 is defined at least partially by an upper edge 70, an opposite lower edge 72 of the curtain, and front and rear portions 74 and 76, respectively, of the inflatable curtain spaced apart horizontally along the upper and lower edges. The front and rear portions 74 and 76 of the inflatable curtain 14 include front and rear edges 80 and 82, respectively, that are spaced horizontally apart along the upper and lower edges 70 and 72 and extend between the upper and lower edges. As illustrated in FIGS. 3-5, a vehicle roof rail 100 is located at the intersection of the side structure 16 of the vehicle and the vehicle roof 18. The side structure 16, roof 18 and roof rail 100 are formed from pieces of sheet metal that are stamped or otherwise formed into predetermined shapes and welded or otherwise connected to form a desired structure. As best shown in FIGS. 4 and 5, inner and outer pieces of sheet metal 102 and 104, respectively, are used to form the side structure 16, roof 18 and roof rail 100. A third piece of sheet metal 106 helps to form the B pillar 32 of the vehicle 12. Those skilled in the art will, however, appreciate that the side structure 16, roof 18, roof rail 100, and B pillar 32 may have alternative constructions. The brackets 120 are preferably constructed of a single piece of high-strength material, such as metal, that may be formed through a variety of metalworking operations, such as stamping, hydroforming, bending, and machining. Alternative materials, such as plastics or composites, and alternative constructions, such as a multi-piece construction, could also be used to form the brackets 120. Referring to FIGS. 6A and 6B, each bracket 120 includes a connecting portion 130, a fill tube support portion 140, and a deployment portion 150. The deployment portion 150 spans the length of the bracket 120. The deployment portion 150 includes a generally planar main portion 152 and a ramp portion 154. The ramp portion 154 curves away from a lower edge portion 156 of the main portion 152 and extends transverse to the main portion. For example, in the embodiment illustrated in FIGS. 1-6B, the ramp portion 154 may extend at an angle of about 105 degrees relative to the main portion 152. The fill tube support portion 140 includes a pair of spaced generally C-shaped supports 142 that extend transversely from an upper edge portion 158 of the main portion 152, opposite the lower edge portion 156. The fill tube support portion 140 may include one or more such supports 142. Each of the supports 142 has a first end portion 144 that merges with the upper edge portion 158 and extends away from the main portion 152 in a general direction similar to that in which the ramp portion 154 extends. Each of the supports 142 also has a second end portion 146 opposite the first end portion 144 that terminates vertically above the first end portion. Each of the supports 142 also has a central or middle portion 145 that has a generally curved or C-shaped configuration and extends between the first and second end portions 144 and 146. The connecting portion 130 includes a pair of spaced flange portions 132, each of which may include an aperture 134 that extends through the flange. A flange portion 132 is associated with a respective one of the supports 142. The connecting portion 130 may include one or more such flange portions 132, depending on the number of supports 142 included on the bracket 120. Each flange portion 132 extends transversely from the second end portion 146 of the support 142 with which it is associated. The flange portions 132 may be coplanar with the main portion 152 of the deployment portion 150. Each support 142 also includes a tab portion 148 that extends transversely from its second end portion 146 in a direction opposite the corresponding respective flange portion 132. As shown in FIGS. 6A and 6B, the fill tube support portion 140 and deployment portion 150 may have edge portions that are rounded over. In the embodiment of FIGS. 6A and 6B, the supports 142 of the fill tube support portion 140 may have rounded over edge portions 160 that extend along opposite lateral edges 162 of the supports. The deployment portion 150 has a rounded over edge portion 170 (FIGS. 4 and 5) that extends along opposite lateral edges 172 of the main portion 152, along opposite lateral edges 174 of the ramp portion 154, and along a forward edge 176 of the ramp portion 154. The fill tube support portion 140 and the deployment portion 150 may also include reinforcing portions for improving their structural integrity. In the embodiment of FIGS. 6A and 6B, the supports 142 of the fill tube support portion 140 may include reinforcing ribs 180 spaced along a curved portion of the supports that extends between the first and second end portions 144 and 146. The deployment portion 150 may include reinforcing ribs 182 that extend between the main portion 152 and the ramp portion 154. The reinforcing ribs 180 and 182 may help prevent the fill tube support portion 140 and deployment portion 150 from bending or being otherwise deformed from the condition illustrated in FIGS. 6A and 6B. As shown in FIG. 1, the inflatable curtain 14 and cover 26 may have respective apertures 190 that expose portions of the fill tube 22. In an assembled condition of the apparatus 10, the brackets 120 may extend through the apertures 190 in the inflatable curtain 14 and cover 26 such that the fill tube 22 may be received in the supports 142. Referring to FIGS. 4 and 5, with the fill tube 22 positioned in the supports 142, the tab portions 148 may be bent over or otherwise deformed to lock the supports onto the fill tube. The tab portions 148 may be bent over with a force sufficient to cause the fill tube 22 to be clamped in the supports 142. The fill tube support portion 140 is thus operative to connect the fill tube 22 to the bracket 120. When the fill tube 22 is connected to the bracket 120, a cylindrical outer surface 23 of the fill tube may mate with a cylindrical portion of an inner surface 143 of the supports 142. In the assembled condition, the inflatable curtain 14 (FIG. 1), cover 26, fill tube 22, inflator 24, and brackets 120 may form a module 200 that may be installed in the vehicle 12. As shown in FIGS. 4 and 5, the module 200 is positioned adjacent the roof rail 100 near the intersection of the side structure 16 and roof 18. Fasteners 202, such as bolts, may then be passed through the apertures 134 in the supports 132 and screwed into the roof rail 100 to secure the module 200 fixedly to the vehicle 12. The bracket 120 may include projections 240, such as hooks, that may be used initially to support the module 200 in the vehicle 12 while the fasteners 202 are installed. When the module 200 is installed in the vehicle 12, the main portion 152 extends along the side structure 16 of the vehicle 12 in a direction generally downward and away from the vehicle roof 18, as viewed in FIGS. 4 and 5. The ramp portion 154 extends transverse to the main portion 152 in a direction generally away from the vehicle side structure 16, diagonally downward and inboard of the vehicle side structure, as viewed in FIGS. 4 and 5. The deployment portion 150 forms a generally concave channel 230 for receiving the inflatable curtain 14 and cover 26 in a stored condition. The inflatable curtain 14 can be placed in the stored condition by rolling the curtain in an outboard direction, as shown in FIG. 4, or by rolling the curtain in an opposite inboard direction (not shown). Alternatively, the inflatable curtain 14 can be placed in the stored condition by folding the curtain or by a combination of rolling and folding the curtain. The module 200, when in the installed condition of FIGS. 1 and 4, extends along the roof rail 100 and along the intersection of the side structure 16 and the roof 18. The vehicle 12 includes a headliner 210 that extends along an inner surface 212 of the roof 18 of the vehicle. The headliner 210 has a portion 214 that extends at an acute angle relative to the roof 18 adjacent the module 200. The portion 214 of the headliner 210 overlies the module 200 and conceals the module in the vehicle 12. A terminal end 216 of the headliner 210 is in abutting engagement with a trim piece 220 of the vehicle 12. Those skilled in the art will recognize that the configuration of the vehicle structure and, thus, the spatial and interconnecting relationships between the vehicle structure (i.e., the side structure 16, roof 18, and roof rail 100) and the headliner 210, trim piece 220 and module 200 may vary depending upon the particular design of the vehicle 12. Therefore, it should be recognized that the vehicle structure illustrated in FIGS. 4 and 5 and the spatial and interconnecting relationships between the vehicle structure and the headliner 210, trim piece 220 and module 200 is for illustrative purposes and may vary without departing from the spirit of the present invention. As shown in FIG. 4, the trim piece 220 overlies the B pillar 32 of the vehicle 12 and is positioned generally adjacent and below the module 200. Similar trim pieces (not shown) may also overlie the A pillar 30 and C pillar 34 (FIGS. 1 and 2) of the vehicle 12. The configuration of the vehicle structure and the spatial and interconnecting relationships between the vehicle structure and the headliner 210, trim piece 220 and module 200 at these locations would be similar to that illustrated in FIGS. 4 and 5. Therefore, FIGS. 4 and 5 may be illustrative of the module 200 and the vehicle 12 at the A pillar 30, B pillar 32, and C pillar 34 of the vehicle 12. The vehicle 12 includes a sensor mechanism 250 (shown schematically in FIGS. 1 and 2) for sensing the occurrence of an event for which inflation of the inflatable curtain 14 is desired, such as a side impact to the vehicle 12 and/or a vehicle rollover. Upon sensing the occurrence of such an event, the sensor mechanism 250 provides an electrical signal over lead wires 252 to the inflator 24. The electrical signal causes the inflator 24 to be actuated in a known manner. The inflator 24 discharges fluid under pressure through fill tube 22, which directs the fluid into the inflatable curtain 14. The inflatable curtain 14 inflates under the pressure of the inflation fluid from the inflator 24. This causes the cover 26 to open, for example, along a tear seam (not shown), which permits the curtain to inflate away from the roof 18 in a downward direction as shown in the drawings and in a downward direction with respect to the direction of forward travel of the vehicle 12 into the position illustrated in FIG. 2. The inflatable curtain 14, when inflated, extends along the side structure 16 of the vehicle 12 and is positioned between the side structure and any occupant of the vehicle. The inflatable curtain 14 covers portions of the vehicle side structure that extend between the A pillar 30 and the C pillar 34 of the vehicle 12 and may overlie portions of the A pillar, C pillar, and the B pillar 32 of the vehicle. The inflatable curtain 14, when inflated, may be positioned between the vehicle side structure 16 and the front and rear vehicle seating 44 and 46. Those skilled in the art will appreciate that the extent and coverage of the inflatable curtain 14 in the vehicle 12 may vary. For example, the extent and coverage of the inflatable curtain 14 may vary depending on a variety of factors, such as the architecture of the vehicle 12, the position of the inflatable curtain 14 in the vehicle, and the desired extent or coverage of the inflatable curtain. The inflatable curtain 14, when inflated, helps to protect a vehicle occupant in the event of a vehicle rollover or a side impact to the vehicle 12. The inflatable curtain 14 may cover an area of the side structure 16 extending from the A pillar 30 to the C pillar 34 and from the roof 18 down to adjacent or below the side windows 40 and 42. The inflatable curtain 14, when inflated, helps to absorb the energy of impacts with the curtain and helps to distribute the impact energy over a large area of the curtain. Referring to FIGS. 4 and 5, as a feature of the present invention, the deployment portion 150 helps to deflect or otherwise direct the inflatable curtain 14 to inflate inboard of the trim piece 220, between the trim piece and any occupant of the vehicle. During inflation of the inflatable curtain 14, the ramp portion 154 of the deployment portion 150 helps prevent the curtain from getting caught on the trim piece 220 or inflating between the trim piece and the side structure 16. The ramp portion 154 directs the inflatable curtain 14 to deploy in an inboard direction (i.e., to the left as viewed in FIGS. 3-5) around the trim piece 220. As shown in FIGS. 1 and 2, the brackets 120 are positioned along the side structure 16 to coincide with the A pillar 30, B pillar 32, and C pillar 34 of the vehicle 12. This places ramp portions 154 adjacent respective trim pieces on the pillars and thus helps direct the inflatable curtain 14 to inflate inboard of these trim pieces at each of the pillars. A second embodiment of the present invention is illustrated in FIGS. 7A and 7B. The second embodiment of the invention is similar to the first embodiment of the invention illustrated in FIGS. 1-6B. Accordingly, numerals similar to those of FIGS. 1-6B will be utilized in FIGS. 7A and 7B to identify similar components, the suffix letter “a” being associated with the numerals of FIGS. 7A and 7B to avoid confusion. The second embodiment of the present invention is similar to the first embodiment, except that the bracket of the second embodiment has a different configuration than the bracket of the first embodiment. Referring to FIGS. 7A and 7B, an apparatus 10a comprises a bracket 120a that includes a connecting portion 130a, a fill tube support portion 140a, and a deployment portion 150a. The deployment portion 150a spans the length of the bracket 120a. The deployment portion 150a includes a generally planar main portion 152a and a ramp portion 154a. The ramp portion 154a curves away from a lower edge portion 156a of the main portion 152a and extends transverse to the main portion. For example, in the embodiment of FIGS. 7A and 7B, the ramp portion 154a may extend at an angle of about 105 degrees relative to the main portion 152a. The fill tube support portion 140a includes a pair of spaced supports 300 that extend transversely from upper edge portion 158a of the main portion 152a, opposite the lower edge portion 156a. The fill tube support portion 140a may include one or more such supports 300. Each support 300 includes a clamping portion 302 that has a generally C-shaped cross-section and merges with the upper edge portion 158a. Each of the supports 300 also includes a clamping flange portion 304 that extends generally parallel to the main portion 152a. Portions of each clamping flange portion 304 overlie respective portions of the main portion 152a. Each clamping flange portion 304 has an aperture 306 that is aligned with a respective aperture 308 in the main portion 152a. The connecting portion 130a includes a flange portion 320. The connecting portion 130a may include more than one such flange portion 320. The flange portion 320 of the second embodiment is a piece of metal separate from the single piece used to construct the fill tube support portion 140a and deployment portion 150a. The flange portion 320 includes a main portion 322 fixed to the main portion 152a of the deployment portion 150a by known means, such as welding. A shoulder portion 324 extends transversely from the main portion 322 and extends away from the deployment portion 150a. A fixing portion 326 extends transversely from the shoulder portion 324 and generally parallel to the main portion 322. An aperture 330 extends through the fixing portion 326. A projection 332, such as a hook, projects from a lateral edge of the fixing portion 326 in a direction away from the deployment portion 150a. As shown in FIGS. 7A and 7B, the fill tube support portion 140a and deployment portion 150a may have edge portions that are rounded over. The connecting portion 130a, fill tube support portion 140a, and deployment portion 150 may also include reinforcing portions, such as ribs, for improving their structural integrity. In an assembled condition of the apparatus 10a, the brackets 120a may extend through respective apertures in the inflatable curtain and cover (not shown) such that the fill tube (not shown) may be received in the clamping portions 302 of the supports 300. With the fill tube positioned in the supports 300, means (not shown), such as a fastener, may be installed in the overlying apertures 306 and 308 to urge the clamping flange portion 304 against the deployment portion 150a and clamp the fill tube in the supports. The fill tube support portion 140a is thus operative to connect the fill tube to the bracket 120a. The inflatable curtain, cover, fill tube, and inflator (not shown) may be installed in the vehicle in a manner similar to that described in reference to the first embodiment of FIGS. 1-6B. From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>It is known to inflate an inflatable vehicle occupant protection device to help protect a vehicle occupant. One particular type of inflatable vehicle occupant protection device is an inflatable curtain. The inflatable curtain is inflatable away from the roof of the vehicle between a vehicle occupant and the side structure of the vehicle in response to a side impact to the vehicle and/or a vehicle rollover. A known inflatable curtain is inflated from a deflated condition with inflation fluid directed from an inflator to the inflatable curtain. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention relates to an apparatus for helping to protect an occupant of a vehicle that has a roof, a side structure, and a trim piece overlying the side structure. The apparatus includes an inflatable curtain inflatable away from the roof to a position adjacent the side structure. An inflation fluid source provides inflation fluid for inflating the inflatable curtain. A fill tube directs inflation fluid from the inflation fluid source into the inflatable curtain. A bracket connects the fill tube to the vehicle. The bracket includes a fill tube support portion connectable with the fill tube. A connecting portion is connectable with the vehicle. A deployment portion directs the inflatable curtain to deploy inboard of the trim piece. The present invention also relates to an apparatus for helping to protect an occupant of a vehicle that has a roof, a side structure, and a trim piece overlying the side structure. The apparatus includes an inflatable curtain that is inflatable away from the vehicle roof to a position adjacent the side structure of the vehicle. An inflation fluid source provides inflation fluid for inflating said inflatable curtain. A fill tube directs inflation fluid from the inflation fluid source into the inflatable curtain. A bracket connects the fill tube to the vehicle and directs the inflatable curtain to deploy inboard of the trim piece. | 20040209 | 20070213 | 20050811 | 68838.0 | 0 | FLEMING, FAYE M | SUPPORT BRACKET FOR AN INFLATABLE CURTAIN | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,775,043 | ACCEPTED | Screed mold method | A screed mold method for continuously or periodically molding thermoplastic material into a cushioning element is disclosed. | 1. A screed mold method for making gelatinous elastomer gel cushioning articles, the method comprising the steps of: obtaining a screed mold, the screed mold havign a rigid body, the screed mold being an open face mold, the screed mold having a honeycomb shape in said rigid body in which gel may be formed to take on a desired geometric structure, the screed mold including a plurality of criscrossing slots in said rigid body to form said honeycomb shape which estabishes a mold core, obtaiing side rails, attaching side rails to the perimeter of the mold in order to surround the perimeter of the mold with side rails, obtaining access to an injection head, said injection head having a plurality of distribution channels therein through which thermoplastic material may flow, said distribution channels being subdivided into sub-distribution channels, said distribution channels terminating in exit ports through which thermoplastic material may exit said injection head and enter said screed mold, said injection head including at least one heating element within it for heating thermoplastic material, positioning said injection head adjacent said screed mold in a location so that thermoplastic material may flow from said injection head distribution channels out of said exit ports and into said screed mold slots, accessing a pumping source, utilizing said pumping source to pressurize thermoplastic material and force it into said injection head, through said distribution channels of said injection head, out of said exit ports of said injection head, into said screed mold, through said slots in said screed mold and out of said screed mold, recovering molded thermoplastic material from said screed mold in a desired geometric shape of a cushioning element. 2. A method as recited in claim 1 wherein said recovering step includes periodically terminating pumping of thermoplastic material into said screed mold, and during such period of termination, removing molded thermoplastic material from said screed mold. 3. A method as recited in claim 1 wherein said pumping is a continuous process, and molded thermoplastic material is recovered from said screed mold as unmolded theremoplastic material is forced into said screed mold. 4. A method as recited in claim 1 wherein molded theremoplastic material is recovered from said screed mold by cutting it as it exits said screed mold due to new thermoplastic material being forced into said screed mold. 5. A method as recited in claim 1 wherein at least some of said slots are cut not more than 80% of the way through said rigid body. 6. A method as recited in claim 1 wherein at least some of said slots are cut all the way through said rigid body. 7. A method as recited in claim 1 wherein said rigid body is metallic. 8. A method as recited in claim 1 wherein said rigid body is non-metallic. 9. A method as recited in claim 1 wherein at least some of said slots cross each other in an “X” configuration. 10. A method as recited in claim 1 wherein at least some of said slots cross each other in a “+” configuration. 11. A method as recited in claim 1 wherein said slots are sized to permit thermoplastic material to flow therethrough when heated. 12. A method as recited in claim 1 further comprising at least one cooling channel in said distribution head. 13. A method as recited in claim 1 further comprising the step of establishing a desired distance between said distribution head and said screed mold prior to flow of thermoplastic material. 14. A method as recited in claim 1 wherein said theremoplastic material includes an A-B-A triblock copolymer. 15. A method as recited in claim 14 wherein said theremoplastic material includes a plasticizer. 16. A screed mold method for making gelatinous elastomer gel cushioning articles, the method comprising the steps of: obtaining a screed mold, the screed mold havign a rigid body, the screed mold being an open face mold, the screed mold having a structural shape in said rigid body in which gel may be formed to take on a desired geometric structure, said structural shape including slots in said rigid body, obtaining access to an injection head, said injection head having a plurality of distribution channels therein through which thermoplastic material may flow, said distribution channels terminating in exit ports through which thermoplastic material may exit said injection head and enter said screed mold, accessing a pumping source, utilizing said pumping source to pressurize thermoplastic material and force it into said injection head, through said distribution channels of said injection head, out of said exit ports of said injection head, into said screed mold, through said slots in said screed mold and out of said screed mold, and receiving a cushioning element molded by said screed mold. 16. A method as recited in claim 15 wherein said receivering step includes periodically terminating pumping of thermoplastic material into said screed mold, and during such period of termination, removing molded thermoplastic material from said screed mold. 17. A method as recited in claim 15 wherein said pumping is a continuous process, and molded thermoplastic material is recovered from said screed mold as unmolded theremoplastic material is forced into said screed mold. 18. A method as recited in claim 15 wherein molded theremoplastic material is recovered from said screed mold by cutting it as it exits said screed mold due to new thermoplastic material being forced into said screed mold. 19. A method as recited in claim 15 wherein at least some of said slots are cut not more than 80% of the way through said rigid body. 20. A method as recited in claim 15 wherein at least some of said slots are cut all the way through said rigid body. 21. A method as recited in claim 15 wherein said rigid body is metallic. 22. A method as recited in claim 15 wherein said rigid body is non-metallic. 23. A method as recited in claim 15 wherein at least some of said slots cross each other in an “X” configuration. 24. A method as recited in claim 15 wherein at least some of said slots cross each other in a “+” configuration. 25. A method as recited in claim 15 wherein said slots are sized to permit thermoplastic material to flow therethrough when heated. 26. A method as recited in claim 15 further comprising at least one cooling channel in said distribution head. 27. A method as recited in claim 15 further comprising the step of establishing a desired distance between said distribution head and said screed mold prior to flow of thermoplastic material. 28. A method as recited in claim 15 wherein said theremoplastic material includes an A-B-A triblock copolymer. 29. A method as recited in claim 16 wherein said theremoplastic material includes a plasticizer. | BACKGROUND This disclosure relates to manufacturing processes using open-faced molds which are useful in manufacturing moldable materials, such as thermoplastic materials, and are particularly useful in manufacturing elastomeric articles including articles comprising elastomeric gel. The methods and structures are especially useful in open-face molding of materials which are of high viscosity or otherwise have a difficulty in flowing into the cavities of an open-faced mold. SUMMARY Screed molding methods are disclosed. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 1A depict an example screed mold. FIGS. 2, 2A and 2B depict other views of an example screed mold. FIG. 3 depicts an example gel mattress component made by a screed mold method. DETAILED DESCRIPTION FIG. 1 depicts the top face of an open faced mold 100, in this case an open faced mold for a mattress topper. The mold 100 is one component of an embodiment. The open faced mold 100 is further characterized as comprising a honeycomb 104. The honeycomb 104 is made up of slots 101 (perpendicularly or at other angles) crisscrossing each other from side rails 102 which surround the perimeter 105 of the honeycomb 104. Slots 101 are spaced so that square [(or other shaped)] mold cores 103 are distributed throughout the honeycomb 104. The mold 100 may be created in a variety of sizes for any desired size mattress. When the mattress has a foam perimeter border (not shown) of approximately 15 cm, the gel honeycomb 104 would have a length of about 170 cm and a width of about 120 cm. In this embodiment, the slots 101 have a depth of about 7 cm and the mold cores 103 concurrently have a height of 7 cm. In one embodiment, the mold 100 is made of a metal plate A110 as depicted in FIG. 1A. The slots A111 may be manufactured in the mold 100 by machining with a circular saw blade (or other cutting tool) about 80% through the thickness of a metal plate A110 forming mold cores A113. In other embodiments, the mold 100 may be made of a non-deforming polymer such as plastic . . . , wood, ceramic or other material not subject to deformation at the temperature of injection. After slots A111 are machined, the perimeter A115 is milled off, to 80% or up to 100% depth. Bolt holes A116 are drilled in the metal plate A110. Referring again to FIG. 1, mold 100 can be bolted or otherwise affixed to four side rails 102. Side rails 102 may be made of various materials including metallic and non-metallic materials. Aluminum may be used in one embodiment for quick heating and cooling. In another embodiment steel can serve as an appropriate material for the side rails. In still another embodiment, non-metallic materials could be used. As shown in FIG. 1, the honeycomb 104 displays a pattern for slots 101. As an example, slots 101 form a 45 degree angle with the perimeter 105 of the mold 100. In this “x” configuration, thermoplastic material (not shown) which is introduced into the mold with a flow path in the “up” direction of FIG. 1 can easily flow around the mold cores 103. In an alternative embodiment, slots 101 form a 90 degree angle with the perimeter 105 to form a “+” configuration. A gel honeycomb 104 in the “x” configuration results in the injected material meeting at a corner 106 instead of a center 107 of a mold core 103 and then continuing to flow around an adjacent core. In contrast, the inventors' experience with the “+” configuration results in molten material meeting at a center 107 of a mold core 103. When the molten material fills the honeycomb 104 in this manner, knit lines might be introduced in the molded part, which can weaken the part. Another component in the embodiments is depicted in FIG. 2. FIG. 2. shows a cross sectional view of injection head 200. Injection head 200 comprises a top face 210 and a bottom face 204. In the top face 210, an inlet 201 opens to a network of distribution channels 202. Molten material (not shown) enters the inlet 201 and flows throughout distribution channels 202 until the material exits outlets 211 at the bottom face 204 and into slot 203. The distribution channel begins at the inlet 201 as one channel and divide into two channels symmetrically. The distribution channels 202 can divide again and again until there are several channels. The more frequently the channels divide, the more outlets 211 will appear in the slot 203. The advantage of increasing the number of outlets is that it allows for more uniform distribution of molten material into the slot. As depicted in FIG. 2, the distribution channels in one embodiment divide with uniform frequency and with uniform distribution of outlets. In another embodiment, depicted in FIG. 2B, distribution channels do not divide with uniform frequency and uniformity of distribution outlets. In this embodiment, molten material flows through distribution head 220 more readily to distribution channel 221 and less readily to distribution channel 222. When the injection head 220 is configured in this way, an uneven distribution of molten material can be applied to a suitable mold which has an uneven requirement for injected material. One skilled in the art can appreciate that a side of a mold with greater material volume demands could be fed by outlets 223 coming from distribution channel 221 and a side of a mold with lesser material volume demands can be fed by outlets 224 coming from distribution channel 222. By way of example, if the product to be molded is thicker in the center and thinner along the edges, greater material flow is desired in the center than along the edges. Larger exit holes and/or more exit holes in a particular area of the head would facilitate greater flow in that area of the head. Those skilled in the art of extrusion dies will appreciate how to control flow in the head. Optimally, the head should be constructed so that there are no dead spots where flow stops and material collects. It is important to have continuous flow of molten material so that when the head is heated, there is no non-moving material to degrade over time. Referring to FIG. 2A, wherein a distribution head 200 is depicted as a cross-sectional side view, distribution channels 202 are shown as cross-sectional tubes 207. Heating elements and/or cooling channels 205 are distributed throughout the distribution head 200 to heat or maintain the temperature of the molten materials as it passes through the distribution channels 202. The heating elements may be fixed cartridges in the distribution head or may also be circulating tubes through which a heated fluid may pass through. Cooling channels are circulating tubes through which a cooled fluid may pass. In other embodiments, the distribution head can be simplified so that the molten material is pumped into a single heated reservoir within a head and exits at drilled holes along the length of the reservoir. In another aspect of the embodiments, the distribution head 200 acts as a screed. A screed levels off a surface. These surfaces may be horizontal or vertical or any other angle, and may be flat or contoured. Process Steps A process for molding thermoset parts or thermoplastic parts or gelatinous elastomer parts is also described. The first step in the process requires a pumping source (typically an extruder) to push a flowable (typically thermosettable liquid and more typically molten thermoplastic) material into a flow-distributing head. The flowable material exits the flow-distributing head at multiple ports into an open-faced mold. The flow-distributing head and open-faced mold must be relatively flush with one another. The flow-distributing head and the open-faced mold are passed relative to each other as the flowable material is distributed into the mold. As the two components move with close proximity, the head serves as a screed. The head screeds molten material from the top of the mold leaving most of the material only in the mold's cavities. In one aspect of the methods and structures the distance between the flow-distributing head and the open-faced mold can be adjusted. With greater distances between the head and the mold, an excess of flowable material increases the thickness of the layer intended to be a permanent part of the molded product. Likewise, when smaller distances stand between the head and the mold, the amount of molten material decreases and the layer thins on the molded product. An advantage of the methods and structures when the head and mold are in close proximity enables additional pressure of the molten material in the cavities of the mold completely filling the mold and strengthening knit line interfaces. The pressure drives even high-viscosity or low-flow materials into the cavities of the mold. Furthermore, the number and degree of knit lines are less of a problem in the methods and structures because in the screeding process, the molten material is better mixed. In one embodiment, mold 100 moves beneath head 200 in close proximity. Concomitantly, molten material is pumped into head 200 at inlet 201 and passes through flow distribution channels 202. Both the molten material and head 200 are heated by cartridge heaters 205. The molten material exits the head 200 also referred to as a screed head at outlets 211 into slot 203. Molten material in slot 203 thus flows into the slots 101 of mold 100 in a uniform fashion. As mattress mold 100 moves beneath head 200, the molten gel fills slots 101 and the flow front continues to fill slots 101 progressively. The proximity of the bottom face 204 of head 200 to mold 100 should be minimized as much as possible given the constraints of machining tolerances so as to minimize the skin that forms on the top of mold 100. The skin may be scraped off before the gel cools and resolidifies. Alternatively, if a skin is desired as part of the finished product, the proximity of head 200 to mold 100 should be about the thickness of the desired skin. After one application process, the mold would be cooled, typically by water. Likewise, the part cast in the mold is cooled and removed by grabbing and stretching it until the part separates from mold 100. In the case of more rigid thermoplastic materials, mold 100 can be transferred to a station which has ejector pins driving the part out of mold 100. In yet another aspect of the methods and structures, it is desirable to affix a fabric or other base material to one side of the gel structure. This is accomplished by machining an appropriate mold. The mold is prepared similar to the prior described mold by making cuts all the way through a metal piece (the I-shaped slots) instead of the 80% cut previously described. A fabric is placed between the mold and the platform on which the mold is placed during the molding process. Thus the molten thermoplastic or cross-linkable liquid or etc. goes from the head completely through the mold and stops at the fabric. The molded material seals itself to the fabric and remains sealed once the material is solidified. In this case, the part must be demolded from the fabric side. The design of the molded part must be such that the mold remains intact while machining 100% through the thickness. Referring to FIG. 3 which shows a top view of an I-beam shaped gel mattress manufactured by the method described of the methods and structures, gel mattress 300 is made up of I-beam shaped gel members 301. The mold remains intact as the separate I-beam shapes 301 are machined. In other molding situations, attaching fabric or other base material of any type can be accomplished by laying the material under the mold before sending the mold under the flowing head. In another embodiment, fabric which is permeable to the flowable material can be placed on the top of the mold. Such fabric may be non-woven, mesh, or screen fabrics. When the flowable material is placed on the top of the mold with a permeable fabric, then material can flow from the head through the fabric. The resulting part is cooled or otherwise solidified and removed from the mold with the fabric intact. Generally the fabric will have material coating it. This method allows fabric to be molded onto the part during the process without having the restrictions on mold configuration incurred by machining 100% through the part. In yet another aspect of the methods and structures, a continuous molding operation is described. Thermoplastic parts can be molded continuously according to the methods and structures. The parts can be rolled up or cut off at intervals. In one embodiment, the leading edge and the trailing edge of each discrete mold are open in such a manner that the trailing edge of the first mold mates in physical fashion with the leading edge of the second mold. In turn, the trailing edge of the second mold mates in physical fashion with the leading edge of the third mold. This linear compatibility may be continued until the last mold is reached and the product or string of products terminate at the trailing edge of the last mold in the series or alternatively, the leading edge of the first mold mates with the trailing edge of last linear mold. In another embodiment of the methods and structures, a second continuous molding operation is described. In this operation, continuous parts are generated by molds situated in a continuous loop. The molds might be described as traveling around the loop like treads of a tracked vehicle such as a tank. Molds in this configuration would be end to end and flat with one another during the top and bottom phases of the loop sequence and would separate somewhat as they went around a curve in the loop from top to bottom and then from bottom to top. In yet another embodiment of the methods and structures, a third continuous molding operation is described and is particularly useful for flexible thermoplastics. In this operational mode, the mold is made in the form of a cylinder with an open-faced mold being on the outer surface of the cylinder and a screed head reasonably flush with the outer surface. In some instances, the bottom face of the screed head may need to be more curved than planar to facilitate appropriate relative distances between the screed head and the mold face. But for many applications of this mode, a planar bottom face will suffice. As the cylinder rotates, the screed head remains stationary. In many of the embodiments described, the screed head also referred to as a distribution head may be kept stationary and the mold is made to move relative to the head. In other embodiments, the screed head is kept stationary while mold is moved. In yet another aspect of the methods and structures, the molds may be preheated before being cast with molten thermoplastic materials. Materials or Material Formulations The material to be molded may be any material which is flowable during molding and can be solidified within the mold cavities. This included thermoplastics, resins, thermoset resins, cements, plasters, without limitation to these categories. It is useful for thermoplastic gelatinous elastomer materials. a. Elastomer Component The compositions of the materials for use in the methods and structures may be low durometer (as defined below) thermoplastic gelatinous elastomeric compounds and visco-elastomeric compounds which include a principle polymer component, an elastomeric block copolymer component and a plasticizer component. The elastomer component of the gel material may include a triblock polymer of the general configuration A-B-A, wherein the A represents a desired polymer such as a monoalkenylarene polymer, including but not limited to polystyrene and functionalized polystyrene, and the B is an elastomeric polymer such as polyethylene, polybutylene, poly(ethylene/butylene), hydrogenated poly(isoprene), hydrogenated poly(butadiene), hydrogenated poly(isoprene+butadiene), poly(ethylene/propylene) or hydrogenated poly(ethylene/butylene+ethylene/propylene), or others. The A components of the material link to each other to provide strength, while the B components provide elasticity. Polymers of greater molecular weight are achieved by combining many of the A components in the A portions of each A-B-A structure and combining many of the B components in the B portion of the A-B-A structure, along with the networking of the A-B-A molecules into large polymer networks. An example elastomer for making the example gel material is a very high to ultra high molecular weight elastomer and oil compound having an extremely high Brookfield Viscosity (hereinafter referred to as “solution viscosity”). Solution viscosity is generally indicative of molecular weight. “Solution viscosity” is defined as the viscosity of a solid when dissolved in toluene at 25-30.degree. C., measured in centipoises (cps). “Very high molecular weight” is defined herein in reference to elastomers having a solution viscosity, 20 weight percent solids in 80 weight percent toluene, the weight percentages being based upon the total weight of the solution, from greater than about 20,000 cps to about 50,000 cps. An “ultra high molecular weight elastomer” is defined herein as an elastomer having a solution viscosity, 20 weight percent solids in 80 weight percent toluene, of greater than about 50,000 cps. Ultra high molecular weight elastomers have a solution viscosity, 10 weight percent solids in 90 weight percent toluene, the weight percentages being based upon the total weight of the solution, of about 800 to about 30,000 cps and greater. The solution viscosities, in 80 weight percent toluene, of the A-B-A block copolymers useful in the elastomer component of the example gel cushioning material are substantially greater than 30,000 cps. The solution viscosities, in 90 weight percent toluene, of the example A-B-A elastomers useful in the elastomer component of the example gel are in the range of about 2,000 cps to about 20,000 cps. Thus, the example elastomer component of the example gel material has a very high to ultra high molecular weight. Applicant has discovered that, after surpassing a certain optimum molecular weight range, some elastomers exhibit lower tensile strength than similar materials with optimum molecular weight copolymers. Thus, merely increasing the molecular weight of the elastomer will not always result in increased tensile strength. The elastomeric B portion of the example A-B-A polymers has an exceptional affinity for most plasticizing agents, including but not limited to several types of oils, resins, and others. When the network of A-B-A molecules is denatured, plasticizers which have an affinity for the B block can readily associate with the B blocks. Upon renaturation of the network of A-B-A molecules, the plasticizer remains highly associated with the B portions, reducing or even eliminating plasticizer bleed from the material when compared with similar materials in the prior art, even at very high oil:elastomer ratios. The reason for this performance may be any of the plasticization theories explained above (i.e., lubricity theory, gel theory, mechanistic theory, and free volume theory). The elastomer used in the example gel cushioning medium is preferably an ultra high molecular weight polystyrene-hydrogenated poly(isoprene+butadiene)-polystyrene, such as those sold under the brand names SEPTON 4045, SEPTON 4055 and SEPTON 4077 by Kuraray, an ultra high molecular weight polystyrene-hydrogenated polyisoprene-polystyrene such as the elastomers made by Kuraray and sold as SEPTON 2005 and SEPTON 2006, or an ultra high molecular weight polystyrene-hydrogenated polybutadiene-polystyrene, such as that sold as SEPTON 8006 by Kuraray. High to very high molecular weight polystyrene-hydrogenated poly(isoprene+butadiene)-polystyrene elastomers, such as that sold under the trade name SEPTON 4033 by Kuraray, are also useful in some formulations of the example gel material because they are easier to process than the example ultra high molecular weight elastomers due to their effect on the melt viscosity of the material. Following hydrogenation of the midblocks of each of SEPTON 4033, SEPTON 4045, SEPTON 4055, and SEPTON 4077, less than about five percent of the double bonds remain. Thus, substantially all of the double bonds are removed from the midblock by hydrogenation. Applicant's most example elastomer for use in the example gel is SEPTON 4055 or another material that has similar chemical and physical characteristics. SEPTON 4055 has the optimum molecular weight (approximately 300,000, as determined by Applicant's gel permeation chromatography testing). SEPTON 4077 has a somewhat higher molecular weight, and SEPTON 4045 has a somewhat lower molecular weight than SEPTON 4055. Materials which include either SEPTON 4045 or SEPTON 4077 as the primary block copolymer typically have lower tensile strength than similar materials made with SEPTON 4055. Kuraray Co. Ltd. of Tokyo, Japan has stated that the solution viscosity of SEPTON 4055, the most example A-B-A triblock copolymer for use in the example gel material, 10% solids in 90% toluene at 25.degree. C., is about 5,800 cps. Kuraray also said that the solution viscosity of SEPTON 4055, 5% solids in 95% toluene at 25.degree. C., is about 90 cps. Although Kuraray has not provided a solution viscosity, 20% solids in 80% toluene at 25.degree. C., an extrapolation of the two data points given shows that such a solution viscosity would be about 400,000 cps. Applicant reads the prior art as consistently teaching away from such high solution viscosities. Applicant confirmed Kuraray's data by having an independent laboratory, SGS U.S. Testing Company Inc. of Fairfield, N.J., test the solution viscosity of SEPTON 4055. When SGS attempted to dissolve 20% solids in 80% toluene at 25.degree. C., the resulting material did not resemble a solution. Therefore, SGS determined the solution viscosity of SEPTON 4055 using 10% solids in 90% toluene at 25.degree. C., which resulted in a 3,040 cps solution. Other materials with chemical and physical characteristics similar to those of SEPTON 4055 include other A-B-A triblock copolymers which have a hydrogenated midblock polymer that is made up of at least about 30% isoprene monomers and at least about 30% butadiene monomers, the percentages being based on the total number of monomers that make up the midblock polymer. Similarly, other A-B-A triblock copolymers which have a hydrogenated midblock polymer that is made up of at least about 30% ethylene/propylene monomers and at least about 30% ethylene/butylene monomers, the percentages being based on the total number of monomers that make up the midblock polymer, are materials with chemical and physical characteristics similar to those of SEPTON 4055. Mixtures of block copolymer elastomers are also useful as the elastomer component of some of the formulations of the example gel cushioning medium. In such mixtures, each type of block copolymer contributes different properties to the material. For example, high strength triblock copolymer elastomers are desired to improve the tensile strength and durability of a material. However, some high strength triblock copolymers are very difficult to process with some plasticizers. Thus, in such a case, block copolymer elastomers which improve the processability of the materials are desirable. In particular, the process of compounding SEPTON 4055 with plasticizers may be improved via a lower melt viscosity by using a small amount of more flowable elastomer such as SEPTON 8006, SEPTON 2005, SEPTON 2006, or SEPTON 4033, to name only a few, without significantly changing the physical characteristics of the material. In a second example of the usefulness of block copolymer elastomer mixtures in the example gel materials, many block copolymers are not good compatibilizers. Other block copolymers readily form compatible mixtures, but have other undesirable properties. Thus, the use of small amount of elastomers which improve the uniformity with which a material mixes are desired. KRATON.®. G 1701, manufactured by Shell Chemical Company of Houston, Tex., is one such elastomer that improves the uniformity with which the components of the example gel material mix. Many other elastomers, including but not limited to triblock copolymers and diblock copolymers are also useful in the example gel material. Applicant believes that elastomers having a significantly higher molecular weight than the ultra-high molecular weight elastomers useful in the example gel material increase the softness thereof, but decrease the strength of the gel. Thus, high to ultra high molecular weight elastomers, as defined above, are desired for use in the example gel material due to the strength of such elastomers when combined with a plasticizer. b. Additives i. Polarizable Plasticizer Bleed-Reducing Additives Preferably, the gel materials used in the cushions of the methods and structures do not exhibit migration of plasticizers, even when placed against materials which readily exhibit a high degree of capillary action, such as paper, at room temperature. A example plasticizer bleed-reducing additive that is useful in the example gel cushioning material includes hydrocarbon chains with readily polarizable groups thereon. Such polarizable groups include, without limitation, halogenated hydrocarbon groups, halogens, nitrites, and others. Applicant believes that the polarizability of such groups on the hydrocarbon molecule of the bleed-reducing additive have a tendency to form weak van der Waals bonding with the long hydrocarbon chains of the rubber portion of an elastomer and with the plasticizer molecules. Due to the great length of typical rubber polymers, several of the bleed-reducers will be attracted thereto, while fewer will be attracted to each plasticizer molecule. The bleed-reducing additives are believed to hold the plasticizer molecules and the elastomer molecules thereto, facilitating attraction between the elastomeric block and the plasticizer molecule. In other words, the example bleed-reducing additives are believed to attract a plasticizer molecule at one polarizable site, while attracting an elastomeric block at another polarizable site, thus maintaining the association of the palsticizer molecules with the elastomer molecules, which inhibits exudation of the plasticizer molecules from the elastomer-plasticizer compound. Thus, each of the plasticizer molecules is preferably attracted to an elastomeric block by means of a bleed-reducing additive. The example bleed-reducing additives that are useful in the example gel material have a plurality of polarizable groups thereon, which facilitate bonding an additive molecule to a plurality of elastomer molecules and/or plasticizer molecules. It is believed that an additive molecule with more polarizable sites thereon will bond to more plasticizer molecules. Preferably, the additive molecules remain in a liquid or a solid state during processing of the gel material. The most example bleed-reducing additives for use in the example gel material are halogenated hydrocarbon additives such as those sold under the trade name DYNAMAR.™. PPA-791, DYNAMAR.™. PPA-790, DYNAMAR.™. FX-9613, and FLUORAD.®. FC 10 Fluorochemical Alcohol, each by 3M Company of St. Paul, Minn. Other additives are also useful to reduce plasticizer exudation from the example gel material. Such additives include, without limitation, other halogenated hydrocarbons sold under the trade name FLUORAD.®., including without limitation FC-129, FC-135, FC-430, FC-722, FC-724, FC-740, FX-8, FX-13, FX-14 and FX-189; halogentated hydrocarbons such as those sold under the trade name ZONYL.®., including without limitation FSN 100, FSO 100, PFBE, 8857A,.™., BA-L, BA-N, TBC and FTS, each of which are manufactured by du Pont of Wilmington, Del.; halogenated hydrocarbons sold under the trade name EMCOL by Witco Corp of Houston, Tex., including without limitation 4500 and DOSS; other halogenated hydrocarbons sold by 3M under the trade name DYNAMAR.™.; chlorinated polyethylene elastomer (CPE), distributed by Harwick, Inc. of Akron, Ohio; chlorinated paraffin wax, distributed by Harwick, Inc.; and others. ii. Detackifiers The example material may include a detackifier. Tack is not a desirable feature in many potential uses for the cushions of the methods and structures. However, some of the elastomeric copolymers and plasticizers useful in the example cushioning media for the cushioning elements of the methods and structures may impart tack to the media. Soaps, detergents and other surfactants have detackifying abilities and are useful in the example gel material. “Surfactants,” as defined herein, refers to soluble surface active agents which contain groups that have opposite polarity and solubilizing tendencies. Surfactants form a monolayer at interfaces between hydrophobic and hydrophilic phases; when not located at a phase interface, surfactants form micelles. Surfactants have detergency, foaming, wetting, emulsifying and dispersing properties. Sharp, D. W. A., DICTIONARY OF CHEMISTRY, 381-82 (Penguin, 1990). For example, coco diethanolamide, a common ingredient in shampoos, is useful in the example gel material as a detackifying agent. Coco diethanolamide resists evaporation, is stable, relatively non-toxic, non-flammable and does not support microbial growth. Many different soap or detergent compositions could be used in the material as well. Other known detackifiers include glycerin, epoxidized soybean oil, dimethicone, tributyl phosphate, block copolymer polyether, diethylene glycol mono oleate, tetraethyleneglycol dimethyl ether, and silicone, to name only a few. Glycerine is available from a wide variety of sources. Witco Corp. of Greenwich, Conn. sells epoxidized soybean oil as DRAPEX 6.8. Dimethicone is available from a variety of vendors, including GE Specialty Chemicals of Parkersburg, W. Va. under the trade name GE SF 96-350. C.P. Hall Co. of Chicago, Ill. markets block copolymer polyether as PLURONIC L-61. C.P. Hall Co. also manufactures and markets diethylene glycol mono oleate under the name Diglycol Oleate—Hallco CPH-I-SE. Other emulsifiers and dispersants are also useful in the example gel material. Tetraethyleneglycol dimethyl ether is available under the trade name TETRAGLYME from Ferro Corporation of Zachary, La. Applicant believes that TETRAGLYME also reduces plasticizer exudation from the example gel material. iii. Antioxidants The example gel material also includes additives such as an antioxidant. Antioxidants such as those sold under the trade names IRGANOX.®. 1010 and IRGAFOS.®. 168 by Ciba-Geigy Corp. of Tarrytown, N.Y. are useful by themselves or in combination with other antioxidants in the example materials of the methods and structures. Antioxidants protect the example gel materials against thermal degradation during processing, which requires or generates heat. In addition, antioxidants provide long term protection from free radicals. A example antioxidant inhibits thermo-oxidative degradation of the compound or material to which it is added, providing long term resistance to polymer degradation. Preferably, an antioxidant added to the example gel cushioning medium is useful in food packaging applications, subject to the provisions of 21 C.F.R. .sctn. 178.2010 and other laws. Heat, light (in the form of high energy radiation), mechanical stress, catalyst residues, and reaction of a material with impurities all cause oxidation of the material. In the process of oxidation, highly reactive molecules known as free radicals are formed and react in the presence of oxygen to form peroxy free radicals, which further react with organic material (hydro-carbon molecules) to form hydroperoxides. The two major classes of antioxidants are the primary antioxidants and the secondary antioxidants. Peroxy free radicals are more likely to react with primary antioxidants than with most other hydrocarbons. In the absence of a primary antioxidant, a peroxy free radical would break a hydrocarbon chain. Thus, primary antioxidants deactivate a peroxy free radical before it has a chance to attack and oxidize an organic material. Most primary antioxidants are known as sterically hindered phenols. One example of sterically hindered phenol is the C.sub.73 H.sub.108 O.sub.12 marketed by Ciba-Geigy as IRGANOX.®. 1010, which has the chemical name 3,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropanoic acid, 2,2-bis [[3-[3,5-bis(dimethylethyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]1,3-propa nediyl ester. The FDA refers to IRGANOX.®. 1010 as tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnimate)]methane. Other hindered phenols are also useful as primary antioxidants in the example material. Similarly, secondary antioxidants react more rapidly with hydroperoxides than most other hydrocarbon molecules. Secondary antioxidants have been referred to as hydroperoxide decomposers. Thus, secondary antioxidants protect organic materials from oxidative degradation by hydroperoxides. Commonly used secondary antioxidants include the chemical classes of phosphites/phosphonites and thioesters, many of which are useful in the example gel material. The hydroperoxide decomposer used by Applicant is a C.sub.42 H.sub.63 O.sub.3 P phosphite known as Tris(2,4-di-tert-butylphenyl)phosphite and marketed by Ciba-Geigy as IRGAFOS.®. 168. It is known in the art that primary and secondary antioxidants form synergistic combinations to ward off attacks from both peroxy free radicals and hydroperoxides. Other antioxidants, including but not limited to multi-functional antioxidants, are also useful in the example material. Multifunctional antioxidants have the reactivity of both a primary and a secondary antioxidant. IRGANOX.®. 1520 D, manufactured by Ciba-Geigy is one example of a multifunctional antioxidant. Vitamin E antioxidants, such as that sold by Ciba-Geigy as IRGANOX.®. E17, are also useful in the example cushioning material for use in the cushions of the methods and structures. The gel material may include up to about three weight percent antioxidant, based on the weight of the elastomer component, when only one type of antioxidant is used. The material may include as little as 0.1 weight percent of an antioxidant, or no antioxidant at all. When a combination of antioxidants is used, each may comprise up to about three weight percent, based on the weight of the elastomer component. Additional antioxidants may be added for severe processing conditions involving excessive heat or long duration at a high temperature. Applicant believes that the use of excess antioxidants reduces or eliminates tack on the exterior surface of the example gel material. Excess antioxidants appear to migrate to the exterior surface of the material following compounding of the material. Such apparent migration occurs over substantial periods of time, from hours to days or even longer. iv. Flame Retardants Flame retardants may also be added to the example gel materials. Flame retardants useful in the cushioning elements of the methods and structures include but are not limited to diatomaceous earth flame retardants sold as GREAT LAKES DE 83R and GREAT LAKES DE 79 by Great Lakes Filter, Division of Acme Mills Co. of Detroit, Mich. Most flame retardants that are useful in elastomeric materials are also useful in the example gel material. In particular, Applicant prefers the use of food grade flame retardants which do not significantly diminish the physical properties of the example gel material. Chemical blowing agents, such as SAFOAM.®. FP-40, manufactured by Reedy International Corporation of Keyport, N.J. and others are useful for making a gel cushioning medium that is self-extinguishing. v. Colorants Colorants may also be used in the example gel materials for use in the cushions of the methods and structures. Any colorant which is compatible with elastomeric materials may be used in the materials. In particular, Applicant prefers to use aluminum lake colorants such as those manufactured by Warner Jenkinson Corp. of St. Louis, Mo.; pigments manufactured by Day Glo Color Corp. of Cleveland, Ohio; Lamp Black, such as that sold by Spectrum Chemical Manufacturing Corp. of Gardena, Calif.; and Titanium Dioxide (white). By using these colorants, the gel material takes on intense shades of colors, including but not limited to pink, red, orange, yellow, green, blue, violet, brown, flesh, white and black. vi. Paint The example gel cushioning medium may also be painted. Vii. Other Additives Other additives may also be added to the example gel material. Additives such as foaming facilitators, tack modifiers, plasticizer bleed modifiers, flame retardants, melt viscosity modifiers, melt temperature modifiers, tensile strength modifiers, and shrinkage inhibitors are useful in specific formulations of the example gel material. Melt temperature modifiers useful in the example gel include cross-linking agents, hydrocarbon resins, diblock copolymers of the general configuration A-B and triblock copolymers of the general configuration A-B-A wherein the end block A polymers include functionalized styrene monomers, and others. Tack modifiers which tend to reduce tack and which are useful in the example gel include surfactants, dispersants, emulsifiers, and others. Tack modifiers which tend to increase the tack of the material and which are useful in the material include hydrocarbon resins, polyisobutylene, butyl rubber and others. Foam facilitators that are useful in the gel material include polyisobutylene, butyl rubber, surfactants, emulsifiers, dispersants and others. Plasticizer bleed modifiers which tend to reduce plasticizer exudation from the example material and which are useful therein include hydrocarbon resins, elastomeric diblock copolymers, polyisobutylene, butyl rubber, transpolyoctenylene rubber (“tor rubber”), and others. 82 Flame retardants useful in the example gel include halogenated flame retardants, non-halogenated flame retardants, and volatile, non-oxygen gas forming chemicals and compounds. Melt viscosity modifiers that tend to reduce the melt viscosity of the pre-compounded component mixture of the example cushioning medium include hydrocarbon resins, transpolyoctenylene rubber, castor oil, linseed oil, non-ultra high molecular weight thermoplastic rubbers, surfactants, dispersants, emulsifiers, and others. Melt viscosity modifiers that tend to increase the melt viscosity of the pre-compounded component mixture of the example gel material include hydrocarbon resins, butyl rubber, polyisobutylene, additional triblock copolymers having the general configuration A-B-A and a molecular weight greater than that of each of the block copolymers in the elastomeric block copolymer component of the material, particulate fillers, microspheres, butadiene rubber, ethylene/propylene rubber, ethylene/butylene rubber, and others. Tensile strength modifiers which tend to increase the tensile strength of the example gel material for use in the cushions of the methods and structures include mid block B-associating hydrocarbon resins, non-end-block solvating hydrocarbon resins which associate with the end blocks, particulate reinforcers, and others. Shrinkage inhibitors, which tend to reduce shrinkage of the gel material following compounding, that are useful in the material include hydrocarbon resins, particulate fillers, microspheres, transpolyoctenylene rubber, and others. c. Microspheres Microspheres may also be added to the example gel material. The gel material may contain up to about 90% microspheres, by volume. In one example microsphere-containing formulation of the example gel material, microspheres make up at least about 30% of the total volume of the material. A second example microsphere-containing formulation of the example gel cushioning medium includes at least about 50% microspheres, by volume. Different types of microspheres contribute various properties to the material. For example, hollow acrylic microspheres, such as those marketed under the brand name MICROPEARL, and generally in the 20 to 200 micron size range, by Matsumoto Yushi-Seiyaku Co., Ltd. of Osaka, Japan, lower the specific gravity of the material. In other formulations of the gel, the microspheres may be unexpanded DU(091-80), which expand during processing of the example gel cushioning medium, or pre-expanded DE (091-80) acrylic microspheres from Expancel Inc. of Duluth, Ga. In formulations of the example material which include hollow acrylic microspheres, the microspheres preferably have substantially instantaneous rebound when subjected to a compression force which compresses the microspheres to a thickness of up to about 50% of their original diameter or less. Hollow microspheres also decrease the specific gravity of the gel material by creating gas pockets therein. In many cushioning applications, very low specific gravities are example. The specific gravity of the example gel cushioning medium may range from about 0.06 to about 1.30, depending in part upon the amount and specific gravity of fillers and additives, including microspheres and foaming agents. In many cushioning applications of the methods and structures, a gel material having a specific gravity of less than about 0.50 is example. When a gel material example for use in cushions according to the methods and structures includes the example microspheres, the microspheres must be dispersed, on average, at a distance of about one-and-a half (1.5) times the average microsphere diameter or a lesser distance from one another in order to achieve a specific gravity of less than about 0.50. A specific gravity of less than about 0.30 is example for use in some cushions according to this methods and structures. Other formulations of the example gel material have specific gravities of less than about 0.65, less than about 0.45, and less than about 0.25. MICROPEARL and EXPANCEL acrylic microspheres are example because of their highly flexible nature, as explained above, which tend to not restrict deformation of the thermoplastic elastomer. Glass, ceramic, and other types of microspheres may also be used in the thermoplastic gel material, but are less example. d. Plasticizer Component As explained above, plasticizers allow the midblocks of a network of triblock copolymer molecules to move past one another. Thus, Applicant believes that plasticizers, when trapped within the three dimensional web of triblock copolymer molecules, facilitate the disentanglement and elongation of the elastomeric midblocks as a load is placed on the network. Similarly, Applicant believes that plasticizers facilitate recontraction of the elastomeric midblocks following release of the load. The plasticizer component of the example gel cushioning medium may include oil, resin, a mixture of oils, a mixture of resins, other lubricating materials, or any combination of the foregoing. i. Oils The plasticizer component of the example gel material may include a commercially available oil or mixture of oils. The plasticizer component may include other plasticizing agents, such as liquid oligomers and others, as well. Both naturally derived and synthetic oils are useful in the example gel material. Preferably, the oils have a viscosity of about 70 SUS to about 500 SUS at about 100.degree. F. Most example for use in the gel material are paraffinic white mineral oils having a viscosity in the range of about 90 SUS to about 200 SUS at about 100.degree. F. One embodiment of a plasticizer component of the example gel includes paraffinic white mineral oils, such as those having the brand name DUOPRIME, by Lyondell Lubricants of Houston, Tex., and the oils sold under the brand name TUFFLO by Witco Corporation of Petrolia, Pa. For example, the plasticizer component of the example gel may include paraffinic white mineral oil such as that sold under the trade name LP-150 by Witco. Paraffinic white mineral oils having an average viscosity of about 90 SUS, such as DUOPRIME 90, are example for use in other embodiments of the plasticizer component of the example gel cushioning medium. Applicant has found that DUOPRIME 90 and oils with similar physical properties can be used to impart the greatest strength to the example gel material. Other oils are also useful as plasticizers in compounding the gel material. Examples of representative commercially available oils include processing oils such as paraffinic and naphthenic petroleum oils, highly refined aromatic-free or low aromaticity paraffinic and naphthenic food and technical grade white petroleum mineral oils, and synthetic liquid oligomers of polybutene, polypropene, polyterpene, etc., and others. The synthetic series process oils are oligomers which are permanently fluid liquid non-olefins, isoparaffins or paraffins. Many such oils are known and commercially available. Examples of representative commercially available oils include Amoco.®. polybutenes, hydrogenated polybutenes and polybutenes with epoxide functionality at one end of the polybutene polymer. Examples of such Amoco polybutenes include: L-14 (320 M.sub.n), L-50 (420 M.sub.n), L-100 (460 M.sub.n), H-15 (560 M.sub.n), H-25 (610 M.sub.n), H-35 (660 M.sub.n), H-50 (750 M.sub.n), H-100 (920 M.sub.n), H-300 (1290 M.sub.n), L-14E (27-37 cst @100.degree. F. Viscosity), L-300E (635-690 cst @210.degree. F. Viscosity), Actipol E6 (365 M.sub.n), E16 (973 M.sub.n), E23 (1433 M.sub.n) and the like. Examples of various commercially available oils include: Bayol, Bernol, American, Blandol, Drakeol, Ervol, Gloria, Kaydol, Litetek, Marcol, Parol, Peneteck, Primol, Protol, Sontex, and the like. ii. Resins Resins useful in the plasticizer component of the example gel material include, but are not limited to, hydrocarbon-derived and rosin-derived resins having a ring and ball softening point of up to about 150.degree. C., more preferably from about 0.degree. C. to about 25.degree. C., and a weight average molecular weight of at least about 300. For use in many of the cushions according to the methods and structures, Applicant prefers the use of resins or resin mixtures which are highly viscous flowable liquids at room temperature (about 23.degree. C.). Plasticizers which are fluid at room temperature impart softness to the gel material. Although room temperature flowable resins are example, resins which are not flowable liquids at room temperature are also useful in the material. The resins most example for use in the example gel material have a ring and ball softening point of about 18.degree. C.; melt viscosities of about 10 poises (ps) at about 61.degree. C., about 100 ps at about 42.degree. C. and about 1,000 ps at about 32.degree. C.; an onset T.sub.g of about −20.degree. C.; a MMAP value of 68.degree. C.; a DACP value of 15.degree. C.; an OMSCP value of less than −40.degree. C.; a M.sub.n of about 385; a M.sub.w of about 421; and a M.sub.z of about 463. One such resin is marketed as REGALREZ.®. 1018 by Hercules Incorporated of Wilmington, Del. Variations of REGALREZ.®. 1018 which are useful in the example cushioning material have viscosities including, but not limited to, 1025 stokes, 1018 stokes, 745 stokes, 114 stokes, and others. Room temperature flowable resins that are derived from poly-.beta.-pinene and have softening points similar to that of REGALREZ.®. 1018 are also useful in the plasticizer component of the example cushioning medium. One such resin, sold as PICCOLYTE.®. S25 by Hercules Incorporated, has a softening point of about 25.degree. C.; melt viscosities of about 10 ps at about 80.degree. C., about 100 ps at about 56.degree. C. and about 1,000 ps at about 41.degree. C.; a MMAP value of about 88.degree. C.; a DACP value of about 45.degree. C.; an OMSCP value of less than about −50.degree. C; a M.sub.z of about 4,800; a M.sub.w of about 1,950; and a M.sub.n of about 650. Other PICCOLYTE.®. resins may also be used in the example gel material. Another room temperature flowable resin which is useful in the plasticizer component of the example material is marketed as ADTAC.®. LV by Hercules Incorporated. That resin has a ring and ball softening point of about 5.degree. C.; melt viscosities of about 10 ps at about 62.degree. C., about 100 ps at about 36.degree. C. and about 1,000 ps at about 20.degree. C.; a MMAP value of about 93.degree. C.; a DACP value of about 44.degree. C.; an OMSCP value of less than about −40.degree. C.; a M.sub.z of about 2,600; a M.sub.w of about 1,380; and a M.sub.n of about 800. Resins such as the liquid aliphatic C-5 petroleum hydrocarbon resin sold as WINGTACK.®. 10 by the Goodyear Tire & Rubber Company of Akron, Ohio and other WINGTACK.®. resins are also useful in the gel material. WINGTACK.®. 10 has a ring and ball softening point of about 10.degree. C.; a Brookfield Viscosity of about 30,000 cps at about 25.degree. C.; melt viscosities of about 10 ps at about 53.degree. C. and about 100 ps at about 34.degree. C.; an onset T.sub.g of about −37.7.degree. C.; a M.sub.n of about 660; a M.sub.w of about 800; a 1:1 polyethylene-to-resin ratio cloud point of about 89.degree. C.; a 1:1 microcrystalline wax-to-resin ratio cloud point of about 77.degree. C.; and a 1:1 paraffin wax-to-resin ratio cloud point of about 64.degree. C. Resins that are not readily flowable at room temperature (i.e., are solid, semi-solid, or have an extremely high viscosity) or that are solid at room temperature are also useful in the example gel material. One such solid resin is an aliphatic C-5 petroleum hydrocarbon resin having a ring and ball softening point of about 98.degree. C.; melt viscosities of about 100 ps at about 156.degree. C. and about 1000 ps at about 109.degree. C.; an onset T.sub.g of about 46.1.degree. C.; a M.sub.n of about 1,130; a M.sub.w of about 1,800; a 1:1 polyethylene-to-resin ratio cloud point of about 90.degree. C.; a 1:1 microcrystalline wax-to-resin ratio cloud point of about 77.degree. C.; and a 1:1 paraffin wax-to-resin ratio cloud point of about 64.degree. C. Such a resin is available as WINGTACK.®. 95 and is manufactured by Goodyear Chemical Co. Polyisobutylene polymers are an example of resins which are not readily flowable at room temperature and that are useful in the example gel material. One such resin, sold as VISTANEX.®. LM-MS by Exxon Chemical Company of Houston, Tex., has a Tg of −60.degree. C., a Brookfield Viscosity of about 250 cps to about 350 cps at about 350.degree. F., a Flory molecular weight in the range of about 42,600 to about 46,100, and a Staudinger molecular weight in the range of about 10,400 to about 10,900. The Flory and Staudinger methods for determining molecular weight are based on the intrinsic viscosity of a material dissolved in diisobutylene at 20.degree. C. Glycerol esters of polymerized rosin are also useful as plasticizers in the example gel material. One such ester, manufactured and sold by Hercules Incorporated as HERCULES.®. Ester Gum 10D Synthetic Resin, has a softening point of about 116.degree. C. Many other resins are also suitable for use in the gel material. In general, plasticizing resins are example which are compatible with the B block of the elastomer used in the material, and non-compatible with the A blocks. In some embodiments of the cushion according to the methods and structures, tacky materials may be desirable. In such embodiments, the plasticizer component of the gel material may include about 20 weight percent or more, about 40 weight percent or more, about 60 weight percent or more, or up to about 100 weight percent, based upon the weight of the plasticizer component, of a tackifier or tackifier mixture. iii. Plasticizer Mixtures The use of plasticizer mixtures in the plasticizer component of the example gel material is useful for tailoring the physical characteristics of the example gel material. For example, characteristics such as durometer, tack, tensile strength, elongation, melt flow and others may be modified by combining various plasticizers. For example, a plasticizer mixture which includes at least about 37.5 weight percent of a paraffinic white mineral oil having physical characteristics similar to those of LP-150 (a viscosity of about 150 SUS at about 100.degree. F., a viscosity of about 30 centistokes (cSt) at about 40.degree. C., and maximum pour point of about −35.degree. F.) and up to about 62.5 weight percent of a resin having physical characteristics similar to those of REGALREZ.®. 1018 (such as a softening point of about 20.degree. C.; an onset T.sub.g of about −20.degree. C.; a MMAP value of about 70.degree. C.; a DACP value of about 15.degree. C.; an OMSCP value of less than about −40.degree. C.; and M.sub.w of about 400), all weight percentages being based upon the total weight of the plasticizer mixture, could be used in a gel cushioning medium. When compared to a material plasticized with the same amount of an oil such as LP-150, the material which includes the plasticizer mixture has decreased oil bleed and increased tack. Applicant believes that, when resin is included with oil in a plasticizer mixture of the example gel for use in cushions according to the methods and structures, the material exhibits reduced oil bleed. For example, a formulation of the material which includes a plasticizing component which has about three parts plasticizing oil (such as LP-150), and about five parts plasticizing resin (such as REGALREZ.®. 1018) exhibits infinitesimal oil bleed at room temperature, if any, even when placed against materials with high capillary action, such as paper. Prior art thermoplastic elastomers bleed noticeably under these circumstances. The plasticizer:block copolymer elastomer ratio, by total combined weight of the plasticizer component and the block copolymer elastomer component, of the example gel cushioning material for use in the cushions of the methods and structures ranges from as low as about 1:1 or less to higher than about 25:1. In applications where plasticizer bleed is acceptable, the ratio may as high as about 100:1 or more. Especially example are plasticizer:block copolymer ratios in the range of about 2.5:1 to about 8:1. A example ratio, such as 5:1 provides the desired amounts of rigidity, elasticity and strength for many typical applications. Another example plasticizer to block copolymer elastomer ratio of the example gel material is 2.5:1, which has an unexpectedly high amount of strength and elongation. Applications The methods and structures herein described applies to molding thermoplastic parts of various sizes but is particularly useful for economically molding large thermoplastic or gelatinous parts. In another aspect of the methods and structures thermoplastic parts that are too soft to be ejected from injection molds by the usual ejector pin method can be molded by the methods and structures. By way of example, an open grate structure 2 m long and 1 m wide by 40 mm deep would require a highly expensive and very complex injection mold, and would require a very large and expensive injection molding machine. The same grate could possibly be made by profile extrusion, but the complexity of the task would discourage those skilled in the art. In addition, the size of the die would be prohibitive. The methods and structures provides less complexity of construction and less costly while still producing excellent quality parts without knit lines common in injection molding. In yet another aspect of the methods and structures, thermoplastic material may be used. When a rigid material is used, the part must be mechanically pushed from the mold by ejector pins or other means. In still another aspect of the methods and structures, gelatinous materials may be used. When gelatinous elastomeric material is used, the molded part can be pulled from the mold by pulling or stretching the part until it comes free from the mold. The methods and structures will work with rigid or soft highly elongatable gels, or materials with elasticity in between. While the methods and structures has been described and illustrated in conjunction with a number of specific configurations, those skilled in the art will appreciate that variations and modifications may be made without departing from the principles herein illustrated, described, and claimed. The methods and structures, as defined by the appended claims, may be embodied in other specific forms without departing from its spirit or essential characteristics. The configurations described herein are to be considered in all respects as only illustrative, and not restrictive. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | <SOH> BACKGROUND <EOH>This disclosure relates to manufacturing processes using open-faced molds which are useful in manufacturing moldable materials, such as thermoplastic materials, and are particularly useful in manufacturing elastomeric articles including articles comprising elastomeric gel. The methods and structures are especially useful in open-face molding of materials which are of high viscosity or otherwise have a difficulty in flowing into the cavities of an open-faced mold. | <SOH> SUMMARY <EOH>Screed molding methods are disclosed. | 20040207 | 20100223 | 20050811 | 84390.0 | 2 | TENTONI, LEO B | SCREED MOLD METHOD | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,775,342 | ACCEPTED | Bistable nematic liquid crystal device | A bistable nematic liquid crystal device cell is provided with a surface alignment grating on at least one cell wall and a surface treatment on the other wall. Such treatment may be a homeotropic alignment or a planar alignment with or without an alignment direction, and zero or a non zero pretilt. The surface profile on the monograting is asymmetric with its groove height to width selected to give approximately equal energy within the nematic material in its two allowed alignment arrangements. The monograting may be formed by a photolithographic process or by embossing of a plastics material. The cell is switched by dc pulses coupling to a flexoelectric coefficient in the material, or by use of a two frequency addressing scheme and a suitable two frequency material. Polarisers either side of the cell distinguish between the two switched states. The cell walls may be rigid or flexible, and are coated with electrode structures, e.g. in row and column format giving an x,y matrix of addressable pixels on the cell. | 1-16. (Cancelled) 17. A bistable nematic liquid crystal device comprising; a first cell wall and a second cell wall, said first cell wall and said second cell wall enclosing a layer of liquid crystal material, wherein said first cell wall has a first surface treated to provide a bistable pretilt to molecules of liquid crystal material and said second cell wall has a first surface treated to provide monostable alignment to molecules of liquid crystal material, wherein said bistable nematic liquid crystal device provides two stable and optically distinguishable liquid crystal configurations. 18. A device according to claim 17 wherein the first surface of the second cell wall is treated with one of a planar, a degenerate planar or a homeotropic surface treatment. 19. A device according to claim 17 wherein said layer of liquid crystal material comprises a nematic liquid crystal material 20. A device according to claim 17 wherein said layer of liquid crystal material comprises a long pitch cholesteric liquid crystal material. 21. A device according to claim 17 wherein the first surface of the first cell wall comprises a plurality of pillars. 22. A device according to claim 21 wherein the height of each of said plurality of pillars is within the range of 1-3 μm. 23. A device according to claim 21 wherein the width of each of said plurality of pillars is within the range of 5-50 μm. 24. A device according to claim 21 wherein the width of each of said plurality of pillars is greater than 50 μm. 25. A device according to claim 21 and further comprising a plurality of beads dispersed in said layer of liquid crystal material. 26. A cell wall for a bistable nematic liquid crystal device, said cell wall having a first surface with a patterned surface profile to provide two different pretilt angles in the same azimuthal plane to molecules of liquid crystal material, wherein said patterned surface profile comprises at least one pillar. 27. A device including a cell wall according to claim 26 wherein the height of each of said plurality of pillars is within the range of 1-3 μm. 28. A device including a cell wall according to claim 26 wherein the width of each of said plurality of pillars is within the range of 5-50 μm. 29. A device including a cell wall according to claim 26 wherein the width of each of said plurality of pillars is greater than 50 μm. 30. A device including a cell wall according to claim 26 wherein said pillars are embossed. 31. A liquid crystal device providing two stable and optically distinguishable liquid crystal configurations, said device comprising a cell wherein said cell has a cell wall according to claim 26. 32. A liquid crystal device providing a first stable liquid crystal configuration and a second stable liquid crystal configuration, said first stable liquid crystal configuration being optically distinguishable from said second stable liquid crystal configuration, said device comprising a cell, said cell having at least one cell wall having a first surface to provide two different pretilt angles in the same azimuthal plane to molecules of liquid crystal material, wherein said first stable liquid crystal configuration is a twisted molecular configuration. 33. A device according to claim 32 wherein said second stable liquid crystal configuration is a non twisted molecular configuration. 34. A device according to claim 32 wherein said molecules of liquid crystal material exhibit positive dielectric anisotropy. 35. A device according to claim 32 wherein said molecules of liquid crystal material exhibit negative dielectric anisotropy. 36. A bistable nematic liquid crystal device comprising; a first cell wall and a second cell wall, said first cell wall and said second cell wall enclosing a layer of liquid crystal material, wherein said first cell wall has a first surface treated to provide two different pretilt angles to molecules of liquid crystal material and said second cell wall has a first surface treated to provide monostable alignment to molecules of liquid crystal material, wherein said bistable nematic liquid crystal device provides two stable and optically distinguishable liquid crystal configurations. | This invention relates to bistable nematic liquid crystal devices. Liquid crystal devices typically comprise a thin layer of a liquid crystal material contained between cell walls. Optically transparent electrode structures on the walls allow an electric field to be applied across the layer causing a re-ordering of the liquid crystal molecules. There are three known types of liquid crystal material, nematic, cholesteric, and smectic each having a different molecular ordering. The present invention concerns devices using nematic materials. In order to provide displays with a large number of addressable elements it is common to make the electrodes as a series of row electrode on one wall and a series of column electrodes on the other cell wall. These form e.g. an x, y matrix of addressable elements or pixels and, for twisted nematic types of devices, are commonly addressed using rms. addressing methods. Twisted nematic and phase change type of liquid crystal devices are switched to an ON state by application of a suitable voltage, and allowed to switch to an OFF state when the applied voltage falls below a lower voltage level, i.e. these devices are monostable. For a twisted nematic type of device (90° or 270° degree twist as in U.S. Pat. No. 4,596,446), the number of elements that can be rms. addressed is limited by the steepness of a device transmission vs voltage curve as details by Alt and Pleschko in IEEE Trans ED vol ED 21 1974 pages 146-155. One way of improving the number of pixels is to incorporate thin film transistors adjacent each pixel; such displays are termed active matrix displays. An advantage of nematic type of devices is the relatively low voltage requirements. They are also mechanically stable and have wide temperature operating ranges. This allows construction of small and portable battery powered displays. Another way of addressing large displays is to use a bistable liquid crystal device. Ferroelectric liquid crystal displays can be made into bistable device with the use of smectic liquid crystal materials and suitable cell wall surface alignment treatment. Such a device is a surface stabilised ferroelectric liquid crystal device (SSFELCDs) as described by:—L J Yu, H Lee, C S Bak and M M Labes, Phys Rev Lett 36, 7, 388 (1976); R B Meyer, Mol Cryst Liq Cryst. 40, 33 (1977); N A Clark and S T Lagerwall, Appl Phys Lett, 36, 11, 899 (1980). One disadvantage of ferroelectric devices is the relatively large voltage needed to switch the material. This high voltage makes small portable, battery powered displays expensive. Also these displays suffer from other problems such as lack of shock resistance, limited temperature range and also electrically induced defects such as needles. If bistable surface anchoring can be achieved using nematics then a display can be made which has the merits of both the above mentioned technologies but none of the problems. It has already been shown by Durand et al that a nematic can be switched between two alignment states via the use of chiral ions or flexoelectric coupling: A Charbi, R Barberi, G Durand and P Martinot-Largarde, Patent Application No WO 91/11747, (1991) “Bistable electrochirally controlled liquid crystal optical device”, G Durand, R Barberi, M Giocondo, P Martinot-Largarde, Patent Application No WO 92/00546 (1991) “Nematic liquid crystal display with surface bistability controlled by a flexoelectric effect”. These are summarised as follows: In Patent Application No WO 91/11747 a device is described with the following characteristics: 1. The cell is made using two surfaces which have SiO coatings of appropriate thickness and evaporation angle to allow two stable states to exist on each surface. Furthermore the two states on a surface are designed to differ in azimuthal angle by 45° and the surfaces are oriented to differ in azimuthal angle by 45° and the surfaces are oriented such that each of the two resulting domains are untwisted. 2. The cell (of 6 μm thickness) is filled with 5CB doped with 0.5% benzyl quininium bromide and 1.8% phenyl lactic acid. The former is an electrically positive chiral ion with left hand twist while the latter is a negative chiral ion with a right hand twist. The concentrations ensure that the final mixture has a very long pitch so that the states in the thin cell are uniform. 3. Application of a 110V dc pulse for 40 μs enabled switching between the two states. A lower threshold is observed for longer pulse e.g. an 80V threshold is observed for 300 μs pulses. 4. Addition of suitably oriented polarisers caused one state to appear black while the other appears white with a contrast ratio of about 20. 5. A variant device is also mentioned which causes a short pitch chiral ion mixture between monostable surfaces which possess different zenithal anchoring energies. Switching between a 180° twisted state and a uniform state is observed in a 4 μm cell for pulses over 50V. In Patent Application WO 92/00546 a device is described with the following characteristics: The cell is made using two surfaces which have SiO coatings of appropriate thickness and evaporation angle to allow two stable states to exist on each surface. Furthermore the two states on a surface are designed to differ in azimuthal angle by 45° and the surfaces are oriented such that each of the two resulting domains are untwisted. The surfaces are also oriented in such a way that the pretilted state on one surface lines up with the untilted state on the other surface and vice versa. Hence when filled with 5CB, the two states are seen as shown in FIGS. 7B and 7C. Application of a 14V dc pulse across a 1 μm cell for 100 μs allows switching between the states. The final state is dependent on the sign of the pulse due to its coupling to the flexoelectric polarisation. The same voltage threshold is observed for switching in both directions. The surface used by Durand to obtain bistable alignment was a thin layer of SiO evaporated at a precise oblique angle. However this method suffers the disadvantage that any deviation in the evaporation angle, layer thickness or indeed any of the deposition parameters is likely to produce a surface with only monostable alignment. This makes the oblique evaporation technique unsuitable, or very difficult, for large area displays. U.S. Pat. No. 4,333,708 describes a multistabl liquid crystal device in which cell walls are profiled to provide an array of singular points. Such substrate configurations provide multistable configurations of the director alignments because disclination must be moved to switch between stable configurations. Switching is achieved by application of electric fields. Another bistable nematic device is described in GB.2,286,467-A. This uses accurately formed bigratings on at least one cell wall. The bigrating permits liquid crystal molecules to adopt two different angular aligned directions when suitable electrical signals are applied to cell electrodes, e.g. dc coupling to flexoelectric polarisation as described in Patent Application No. WO.92/00546. Since in the two splayed state the director is quite close to being in the plane of the layer, the coupling between director and flexoelectric component can be small, which may hinder switching in some circumstances. According to this invention the above disadvantages are overcome by a surface treatment to at least one cell wall that permits nematic liquid crystal molecules to adopt either of two pretilt angles in the same azimuthal plane. The cell can be electrically switched between these two states to allow information display which can persist after the removal of power. The term same azimuthal plane is explained as follows; let the walls of a cell lie in the x,y plane, which means the normal to the cell walls is the z axis. Two pretilt angles in the same azimuthal plane means two different molecular positions in the same x,z plane According to this invention a bistable nematic liquid crystal device comprises; two cell walls enclosing a layer of liquid crystal material; electrode structures on both walls; a surface alignment on the facing surfaces of both cell walls providing alignment to liquid crystal molecules; means for distinguishing between switched states of the liquid crystal material: CHARACTERISED BY a surface alignment grating on at least one cell wall that permits the liquid crystal molecules to adopt two different pretilt angles in the same azimuthal plane; the arrangement being such that two stable liquid crystal molecular configurations can exist after suitable electrical signals have been applied to the electrodes. The grating may have a symmetric or an asymmetric groove profile. The grating may have an asymmetric groove profile which will induce a pretilt of less than 90°, e.g. 50° to 90°. An asymmetric profile may be defined as a surface for which there does not exist a value of h such that; Ψx(h−x)=Ψx(h+x) (1) for all values of x, where Ψ is the function describing the surface. The gratings may be applied to both cell walls and may be the same or different shape on each wall. Furthermore the grating profile may vary within each pixel area, and or in the inter pixel gaps between electrodes. One or both cell walls may be coated With a surfactant such as lethecin. The liquid crystal material may be non twisted in one or both stable molecular configurations. The cell walls may be formed of a relatively thick non flexible material such as a glass, or one or both cells walls may be formed of a flexible material such as a thin layer of glass or a plastic material flexible e.g. polyolefin or polypropylene. A plastic cell wall may be embossed on its inner surface to provide a grating. Additionally, the embossing may provide small pillars (e.g. of 1-3 μm height and 5-50 μm or more width) for assisting in correct spacing apart of the cell walls and also for a barrier to liquid crystal material flow when the cell is flexed. Alternatively the pillars may be formed by the material of the alignment layers. The grating may be a profiled layer of a photopolymer formed by a photolithographic process e.g. M C Hutley, Diffraction Gratings (Academic Press, London 1982) p 95-125; and F Horn, Physics World, 33 (March 1993). Alternatively, the bigrating may be formed by embossing; M T Gale, J Kane and K Knop, J App. Photo Eng, 4, 2, 41 (1978), or ruling; E G Loewen and R S Wiley, Proc SPIE, 88 (1987), or by transfer from a carrier layer. The electrodes may be formed as a series of row and column electrodes arranged and an x,y matrix of addressable elements or display pixels. Typically the electrodes are 200 μm wide spaced 20 μm apart. Alternatively, the electrodes may be arranged in other display formats e.g. r-θ matrix or 7 or 8 bar displays. The invention will now be described, by way of example only with reference to the accompanying drawings of which; FIG. 1 is a plan view of a matrix multiplexed addressed liquid crystal display; FIG. 2 is the cross section of the display of FIG. 1; FIG. 3 shows a top view and a side view of the mask and exposure geometry used to produce a grating surface. FIG. 4 is a cross section of the liquid crystal director configuration on the grating surface which leads to a higher pretilt. FIG. 5 is a cross section of the liquid crystal director configuration on the grating surface which leads to a lower pretilt. FIG. 6 is the energy of the two pretilt configurations as a function of groove depth to pitch ratio (h/w). FIG. 7 shows a cross section of a cell configuration which allows bistable switching between the two states. FIG. 8 shows the transmission of the cell and the applied signals as a function of time. FIG. 9 shows an example multiplexing scheme for the bistable device. FIG. 10 shows an alternative cell configuration for bistable switching. FIG. 11 shows a cell configuration for bistable switching between a non-twisted and a twisted state. The display in FIGS. 1, 2 comprises a liquid crystal cell 1 formed by a layer 2 of nematic or long pitch cholesteric liquid crystal material contained between glass walls 3, 4. A spacer ring 5 maintains the walls typically 1-6 μm apart. Additionally numerous beads of the same dimensions may be dispersed within the liquid crystal to maintain an accurate wall spacing. Strip like row electrodes 6 e.g. of SnO2 or ITO (indium tin oxide) are formed on one wall 3 and similar column electrodes 7 are formed on the other wall 4. With m-row and n-column electrodes this forms an m×n matrix of addressable elements or pixels. Each pixel is formed by the intersection of a row and column electrode. A row driver 8 supplies voltage to each row electrode 6. Similarly a column driver 9 supplies voltages to each column electrode 7. Control of applied voltages is from a control logic 10 which receives power from a voltage source 11 and timing from a clock 12. Either side of the cell 1 are polarisers 13, 13′ arranged with their polarisation axis substantially crossed with respect to one another and at an angle of substantially 45° to the alignment directions R, if any, on the adjacent wall 3, 4 as described later. Additionally an optical compensation layer 17 of e.g. stretched polymer may be added adjacent to the liquid crystal layer 2 between cell wall and polariser. A partly reflecting mirror 16 may be arranged behind the cell 1 together with a light source 15. These allow the display to be seen in reflection and lit from behind in dull ambient lighting. For a transmission device, the mirror 16 may be omitted. Prior to assembly, at least one of the cell walls 3, 4 are treated with alignment gratings to provide a bistable pretilt. The other surface may be treated with either a planar (i.e. zero or a few degrees of pretilt with an alignment direction) or homeotropic monostable surface, or a degenerate planar surface (i.e. a zero or few degrees of pretilt with no alignment direction). Finally the cell is filled with a nematic material which may be e.g. E7, ZLI2293 or TX2A (Merck). An example method used to fabricate the grating surface will now described with reference to FIG. 3. EXAMPLE 1 A piece of ITO coated glass to form the cell wall 3, 4 was cleaned with acetone and isopropanol and was then spin coated with photoresist (Shipley 1805) at 3000 rpm for 30 seconds giving a coating thickness of 0.55 μm. Softbaking was then carried out at 90° C. for 30 minutes. A contact exposure was then carried out on the coated wall 3, 4 using a chrome mask 20 containing 0.5 μm lines 21 and 0.5 μm gaps 22 (hence an overall pitch of 1 μm) as shown in FIG. 3. The exposure was carried out at non-normal incidence, in this case an angle of 60° was used. Mask 20 orientation is such that the groove direction is substantially perpendicular to the to plane of incidence as shown in FIG. 3. Exposure in this geometry leads to an asymmetric intensity distribution and therefore an asymmetric grating profile (see for example B. J. Lin, J. Opt. Soc. Am., 62, 976 (1972)). Coated cell walls 3, 4 were exposed to light from a mercury lamp (Osram Hg/100) with an intensity of 0.8 mW/cm2 for a period of about 40 to 180 seconds as detailed later. After the exposure the coated cell wall 3, 4 was released from the mask 20 and developed in Shipley MF319 for 10 seconds followed by a rinse in de-ionised water. This left the cell wall's surface patterned with an asymmetric surface modulation forming the desired grating profile. The photoresist was then hardened by exposure to deep UV radiation (254 nm) followed by baking at 160° C. for 45 minutes. This was done to ensure insolubility of the photoresist in the liquid crystal. Finally the grating surface is treated with a solution of the surfactant lecithin in order to induce a homeotropic boundary condition. Finite element analysis has been carried out in order to predict the molecular (more correctly the director) configuration of a free layer of nematic material on such grating surfaces. The results are shown in FIGS. 4, 5 and 6 where the short lines represent liquid crystal director throughout the layer thickness, with the envelope of the short lines at the bottom showing the grating profile. In this case the grating surface has been described by the function; y ( x ) = h 2 sin ( 2 π x w + A sin ( 2 π x w ) ) ( 2 ) where h is the groove depth, w is the pitch and A is an asymmetry factor. In FIGS. 4 and 5, A=0.5 and h/w=0.6. In FIG. 4, the finite element grid has been allowed to relax from an initial director tilt of 80°. In this case the configuration has relaxed to a pretilt of 89.5°. However, if the initial director tilt is set to 30° then the grid relaxes to a pretilt of 23.0° as shown in FIG. 5. Therefore the nematic liquid crystal can adopt two different configurations depending on starting conditions. In practice a nematic liquid crystal material will relax to whichever of these two configuration has the lowest overall distortion energy. FIG. 6 shows the total energy (arbitrary units) of the high pretilt (solid circles) and the low pretilt (empty circles) state verses the groove depth to pitch ratio (h/w). For low h/w, the high pretilt state has the lowest energy and so the nematic will adopt a high pretilt state. Conversely for large h/w, the low pretilt state has the lowest energy and so this state is formed. However when h/w=0.52, the states have the same energy and so either can exist without relaxing into the other. Therefore if a surface is fabricated at, or close to this condition, then bistability can be observed in the pretilt. With reference to the above fabrication details, an exposure time of 80 seconds was found to lead to a bistable surface. In this case the bistability is purely a function of the surface and does not rely on any particular cell geometry. In this sense it is distinct from prior art such as U.S. Pat. No. 4,333,708 (1982). One suitable cell configuration to allow switching between the bistable states is shown in FIG. 7 which is a stylised cross section of the device in which a layer 2 of nematic liquid crystal material with positive dielectric anisotropy is contained between a bistable grating surface 25 and a monostable homeotropic surface 26. The latter surface 26 could, for example, be a flat photoresist surface coated with lecithin. Within this device liquid crystal molecules can exist in two stable states. In state (a) both surfaces 25, 26 are homeotropic whereas in (b) the grating surface 25 is in its low pretilt state leading to a splayed structure. For many nematic materials, a splay or bend deformation will lead to a macroscopic flexoelectric polarization which is represented by the vector P in FIG. 7. A dc pulse can couple to this polarisation and depending on its sign will either favour or disfavour configuration (b). With the device in state (a), the application of a positive pulse will still cause fluctuations in the homeotropic structure despite the positive dielectric anisotropy. These fluctuations are sufficient to drive the system over the energy barrier that separates the two alignment states. At the end of the pulse the system will fall into state (b) because the sign of the field couples favourably with the flexoelectric polarisation. With the system in state (b), a pulse of the negative sign will once again disrupt the system but now it will relax into state (a) as its sign does not favour the formation of the flexoelectric polarisation. In its homeotropic state, the bistable surface is tilted at slightly less than 90° (e.g. 89.5°). This is sufficient to control the direction of splay obtained when the cell switches into state (b). One particular cell consisted of a layer of nematic ZLI2293 (Merck) sandwiched between a bistable grating surface and a homeotropic flat surface. The cell thickness was 3 μm. Transmission was measured through the cell during the application of dc pulses at room temperature (20° C.). The polariser and analyser 13, 13′ on each side of the cell 1 were crossed with respect to each other and oriented at ±45° to the grating grooves. In this set up, the two states in FIG. 7, (a) and (b), appear black and white respectively when addressed as follows. FIG. 8 shows the applied voltage pulses (lower trace) and the optical response (upper trace) as a function of time. Each pulse had a peak height of 55.0 volts and a duration of 3.3 ms. Pulse separation was 300 ms. With the first application of a positive pulse, the transmission changes from dark to light indicating that the cell has switched from state FIG. 7(a) to state (b). A second positive pulse causes a transient change in transmission due to the rms effect of coupling to the positive dielectric anisotropy causing a momentary switching of the bulk material to state (a). However, in this case the cell does not latch at the surface and so remains in state (b). The next pulse is negative in sign and so switches the cell from state (b) to state (a). Finally a second negative pulse leaves the cell in state (a). This experiment shows that the cell does not change state on each pulse unless it is of the correct sign. Thus it proves that the system is bistable and that the final state can be reliably selected by the sign of the applied pulse. The switching occurs across a wide temperature range. As the temperature is increased the voltage required for switching falls. For example at 30° C., a voltage of 44.8 V is required for bistable switching whereas at 50° C. the voltage in only 28.8 V. Similarly, for a fixed voltage the required pulse length for latching decreases with temperature. After this data was taken, the cell was dismantled and the grating surface as characterised by AFM (atomic force microscopy). An asymmetric modulation was confirmed which was fitted by equation 2 to give a pitch of 1 μm, a groove depth of 0.425 μm (h/w=0.425) and an asymmetry factor of A=0.5. In comparison to the results in FIG. 6, this grating has its bistable regime at a lower value of h/w (0.425 compared to 0.52). However equation 2 was not a precise fit to the AFM data due to the real surface possessing steeper facet angles which require the addition of higher harmonics in the description. Other effects such as AFM tip radius also need to be considered for a more accurate comparison. Thus it can be concluded that the measured surface modulation is similar to the predicted regime for bistability. The successful switching of a single pixel allows the design of a suitable multiplexing method for the selection of several adjacent pixels. FIG. 9 shows one particular example of such a scheme. As shown pixels in four consecutive rows R1, R2, R3, R4 in one column are to be switched. Two possible alignment states may be arbitrarily defined as ON and OFF states. Rows R1 and R4 are to switched to an ON state, rows R2 and R3 are in the OFF state. Strobe pulses of +Vs for three time slots followed by −Vs for 3 time slots (ts) are applied to each row in turn. A data waveform is applied to the column as shown and comprises a −Vd for 1 ts followed by a +Vd for 1 ts for and ON pixel, and −Vd for 1 ts followed by +Vd for 1 ts for and OFF pixel. Now considering one particular pixel at A. The resultant waveform consists of large positive and negative pulses which disrupt the nematic orientation and raises its energy up to the barrier that separates the two bistable surface states. In this field applied conditon, the liquid crystal molecules align along the electric field as in conventional monostable nematic devices, and as shown in FIG. 7a. These large ‘reset’ pulses of opposite polarity are followed immediately by a smaller pulse which is still large enough to dictate the final selection state of the pixel during the relaxation of the orientation. Electrical balance is achieved by a small pulse of polarity opposite to the switching pulse and preceding the two large pulses. Alternatively, polarity inversion in adjacent display address time may be used. The above bistable device achieves final state selection by virtue of the flexoelectric polarisation in one state. Therefore this configuration must contain splay. In the experimental example only one surface is allowed to switch but working devices can also be made in which both surfaces switch. The only remaining constraint is that the low pretilt states on each surface should differ in value so that a finite splay remains. However even if the low pretilt states are equal, the cell can still be switched if it contains a two frequency nematic material, that is a material whose dielectric anisotropy is positive at low frequencies and negative at high frequencies. An example of such a material is TX2A (Merck) which has a crossover frequency of 6 kHz. FIG. 9 shows a cross section of this configuration. With the cell in state (a), the application of a high frequency signal drives the bulk of the nematic to a low pretilt. The surfaces follow and so the cell switches to state (b). Conversely a low frequency signal will drive the nematic to a high pretilt and so the cell will switch to state (a). EXAMPLE 2 A second example of a bistable device is now described. A piece of ITO coated glass to form the cell wall was cleaned with acetone and isopropanol and was then spin coated with photoresist (Shipley 1813) at 3000 rpm for 30 seconds giving a coating thickness of 1.5 μm. Softbaking was then carried out at 90° C. for 30 minutes. A contact exposure was then carried out using a chrome mask containing 0.5 μm lines and 0.5 μm gaps (hence an overall pitch of 1 μm). In this example the exposure was carried out at normal incidence. Exposure in this geometry leads to a symmetric intensity distribution and therefore a symmetric grating profile. Samples were exposed to light from a mercury amp (Osram Hg/100) with an intensity of 0.8 mW/cm2. After the exposure the sample was released from the mask and developed in Shipley MF319 for 20 seconds followed by a rinse in de-ionised water. This left the sample patterned with a symmetric surface modulation. The photoresist was then hardened by exposure to deep UV radiation (254 nm) followed by baking at 160° C. for 45 minutes. This was done to ensure insolubility of the photoresist in the liquid crystal. Finally the grating surface is treated with a solution of a chrome complex surfactant in order to induce a homeotropic boundary condition. One particular surface was made using the above method with an exposure time of 360 s. AFM analysis on this grating showed it to have a symmetric profile with a pitch of 1 μm and a depth of 1.2 μm. This surface was constructed opposite a flat homeotropic surface to form a call with a thickness of 2.0 μm. The cell was filled with the nematic material E7 (Merck) in the isotropic phase followed by cooling to room temperature. Microscopic observation revealed a mixture of both bistable states, shown as (a) and (b) in FIG. 7. The cell was oriented between crossed polarisers so that the groove direction was at 45° to the polariser directions. Thus state (a) was the bright state while state (b) was the dark state. Monopolar pulses of alternating sign were then applied to the cell. The pulse length was set to 5.4 ms with a 1 s pulse separation. Full switching occurred between state (a) and (b) when the peak voltage of the applied pulses was increased to 20.3 V. Pairs of pulses were also applied to the cell in a similar manner to the data shown in FIG. 8. Once again only the first pulse changed the state of the system while the second pulse only induced a non-latching transient response. In this case the optical response times were also measured. The 10%-90% response time for switching from (a) to (b) was 8.0 ms while the response time for switching from (b) to (a) was 1.2 ms. Further analysis of this cell revealed that the bistable states (a) and (b) induced pretilts of 90° and 0° respectively on the grating surface. Thus this sample has demonstrated the maximum possible change in pretilt. The optics of the configurations shown in FIGS. 7 and 10 is optimised when the cell thickness d is given by:— d = λ 2 Δ n av ( 3 ) where λ is the operating wavelength and Δnav is the average value of the in-plane component (parallel to the cell walls) of the nematic birefringence. Δnav will be larger for the configuration shown in FIG. 10 compared to FIG. 7, hence the cell thickness can be less and therefore the optical switching speed will be larger. However the use of a two frequency nematic limits the choice of available materials, also leads to a more complex addressing scheme, but may allow lower voltage operation. EXAMPLE 3 The bistable grating surface can also be constructed opposite a planar surface. One such cell consisted of a grating with the same profile to that described in example 2. This was constructed opposite a rubbed polymer surface formed using a layer of PI32 polyimide (Ciba Geigy). The rubbing direction on the polyimide surface was set parallel to the grating groove direction on the grating surface. The cell gap was set to 2.5 μm and nematic E7 was used to fill the cell. Cooling to room temperature after filling revealed two states which are shown schematically in FIG. 11. This Figure differs from FIG. 7 in that the groove direction on the bistable surface is now in the plane of the page (in an x,y plane). Thus the 90° pretilt state on the grating forms the hybrid structure shown in (a′) while the 0° pretilt state on the grating forms the twisted structure shown in (b′). To achieve optical contrast between the states, the cell was placed in-between crossed polarisers 13, 13′ oriented so that the grating grooves (and rubbing direction) were parallel to one polariser, although the polarisers may be rotated to optimise contrast in the two switch states. Thus state (b′) was the bright state while state (a′) was the dark state. Using 5.3 ms monopolar pulses, switching between (a′) and (b′) occurred at a peak voltage of 56.7 V. The optical response times were 110 ms for switching from (a′) to (b′) and 1.4 ms for switching from (b) to (a′). The bright state (b′) has a bulk twist of 90°. As with conventional TN structures, the maximum transmission is obtained when N is an integer where (C. H. Gooch and H. A. Tarry, J. Phys. D: Appl. Phys., 8 1575 (1975)); N={square root}{square root over ((Δnd/λ)2+0.25)} (4) where Δn is the nematic birefringence, d is the cell gap and λ is the operating wavelength. Therefore a bistable device using E7 (Δn=0.22) with an operating wavelength of 530 nm and N=1 will have a cell gap of 2.1 μm. In comparison the configuration described in example 2 has an optimum thickness given by equation 3. For that example, Δnav is Δn/2 therefore equation 3 gives a thickness of 1.2 μm. Thus the bistable device without twist will always possess optimum optics at a thinner cell gap and will therefore switch at lower voltages with a shorter optical response time. A cholesteric dopant (eg <1% of CB15 Merck) may be added to prevent twist disclinations. Alternatively these disclinations may be prevented by arranging the groove directions non parallel to the rubbing alignment directions, eg about 5° adjustment. The grating surfaces for these devices can be fabricated using a variety of techniques as listed earlier. The homeotropic treatment can be any surfactant which has good adhesion to the grating surface. This treatment should also lead to an unpinned alignment. That is, an alignment which favours a particular nematic orientation without inducing rigid positional ordering of the nematic on the surface. As seen from the above analysis, the grating modulation has to possess a certain h/w for a given asymmetry for bistability to exist. The absolute scale of the modulation is limited by other factors. If the groove depth and pitch are too large then diffractive effects will be significant and lead to loss of device throughput. Furthermore if the groove depth is similar to the cell thickness then the proximity of the groove peaks to the opposite flat surface may inhibit bistable switching. If two gratings are required as in the device shown in FIG. 10 then a large groove depth compared to cell thickness would inevitably lead to switching which depends on the phase of the two modulations. This would severely complicate the device manufacturing process. Problems also exist if the groove depth and pitch are too small. For a constant h/w, as the pitch becomes smaller the energy density of the bulk distortion at the surface becomes larger. Eventually this energy is similar to the local anchoring energy of the nematic on the surface. Thus the structures shown in FIGS. 4 and 5 (which assume an infinite anchoring energy) would no longer be obtained and bistability would inevitably be lost. Typical values of h and w are, about 0.5 μm and 1.0 μm in a range of about 0.1 to 10 μm and 0.05 to 5 μm respectively. Small amounts e.g. 1-5% of a dichroic dye may be incorporated into the liquid crystal material This may be used with or without a polariser, to provide colour, to improve contrast, or to operate as a guest host type device; e.g. the material D124 in E63 (Merck). The polariser(s) of the device (with or without a dye) may be rotated to optimise contrast between the two switched states of the device. | 20040211 | 20071009 | 20050324 | 57961.0 | 0 | SCHECHTER, ANDREW M | LIQUID CRYSTAL DEVICE EXHIBITING ZERNITHAL BISTABILITY AND A CELL WALL FOR SUCH A DEVICE | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,775,479 | ACCEPTED | Fast searching of list for IP filtering | A method for filtering data packets through computers on the Internet that allows a computer to determine whether an incoming numbered list is present in a numbered list data set faster than the prior art methods. The present invention comprises an Array Creation Program (ACP) and an Array Matching Program (AMP). The ACP creates a plurality of arrays from the numbered list data set. The values of the array fields are based on the numbers in the numbered lists. The AMP analyzes the numbers in the incoming numbered list to determine the hexadecimal values in the array fields associated with the numbers in the incoming numbered list. The AMP uses a counter to process the numbers in the incoming numbered list. If the counter becomes zero, then the incoming numbered list is not present in the numbered list data set. An embodiment utilizing hashtables is also disclosed. | 1. A method for creating a plurality of arrays from a numbered list data set, the method comprising: installing a program on a computer; wherein the program performs steps comprising: assigning an ID to a numbered list; creating the arrays; performing a Boolean OR operation on the ID and an array value; and wherein the computer can determine whether an incoming numbered list is present in the numbered list data set by analyzing the arrays. 2. The method of claim 1 wherein the computer is a firewall. 3. The method of claim 2 wherein the program performs steps further comprising: obtaining the numbered list data set comprising a plurality of the numbered lists; and wherein the numbered lists comprise a plurality of numbers separated by decimals. 4. The method of claim 3 wherein the IDs are sequentially increasing powers of two. 5. The method of claim 4 wherein the quantity of arrays equals the quantity of numbers in the numbered lists. 6. The method of claim 5 wherein the arrays are MAXV fields long, MAXV being the maximum value of any number in the numbered lists or the incoming numbered list. 7. The method of claim 6 wherein the program performs steps further comprising: responsive to the determination that the number is not the wildcard, translating the ID for the numbered list containing the number into a binary ID; and responsive to the determination that the number is not the wildcard, translating the array value with an index equal to the number for the array associated with the number into a binary array value. 8. The method of claim 7 wherein the program performs steps further comprising: determining whether one of the numbers is a wildcard; responsive to the determination that the number is the wildcard, translating the ID for the numbered list containing the number into the binary ID; and responsive to the determination that the number is the wildcard, translating a plurality of the array values for the array associated with the number into a plurality of the binary array values. 9. The method of claim 8 wherein the program performs steps further comprising: translating the binary array value into a hexadecimal array value or a decimal array value. 10. A method for determining whether an incoming numbered list is present in a numbered list data set, the method comprising: installing a program on a computer; wherein the program performs steps comprising: determining whether a number is the first number in the incoming numbered list; responsive to the determination that the number is the first number in the incoming numbered list, setting a counter equal to an array value with an index equal to the number; and wherein the computer can determine whether the incoming numbered list is present in the numbered list data set by analyzing the counter. 11. The method of claim 10 wherein the computer is a firewall. 12. The method of claim 11 wherein the program performs steps further comprising: responsive to the determination that the number is not the first number in the incoming numbered list, performing steps comprising: obtaining the array value with the index equal to the number; performing a Boolean AND operation to generate a result; and setting the counter equal to the result. 13. The method of claim 12 wherein the program performs steps further comprising: determining whether the counter is equal to zero; and responsive to the determination that the counter is equal to zero, indicating that the incoming numbered list is not present in the numbered list data set. 14. The method of claim 13 wherein the program performs steps further comprising: responsive to the determination that the counter is not equal to zero, indicating that the incoming numbered list is present in the numbered list data set. 15. The method of claim 14 wherein the program performs steps further comprising: obtaining the incoming numbered list; and obtaining a plurality of numbered list data set arrays. 16. The method of claim 15 wherein the incoming numbered list comprises a plurality of the numbers separated by decimals. 17. The method of claim 16 wherein the program performs steps further comprising: responsive to the determination that the number is not the first number in the incoming numbered list, performing steps comprising: translating the counter into a binary counter; translating the array value with the index equal to the number into a binary array value; and translating the result into a hexadecimal result or a decimal result. 18. The method of claim 17 wherein the quantity of ones present in the binary counter indicates the location of the match between the incoming numbered list and the numbered list data set. 19. The method of claim 18 wherein the location of ones present in the binary version of the counter indicates the number of times the incoming numbered list is present in the numbered list data set. 20. The method of claim 19 wherein the program performs steps further comprising: determining whether the number is a wildcard; and responsive to the determination that the number is a wildcard, performing a Boolean OR operation between the counter and a value equal to sum of a plurality of IDs for the numbered lists in the numbered list data set. 21. A program product operable on a computer comprising: a computer-usable medium; wherein the computer usable medium comprises instructions for the computer to perform steps comprising: assigning a plurality of IDs to a plurality of numbered lists; creating a plurality of hashtables; creating a wildcard array; performing a Boolean OR operation on one of the IDs and a hashtable value; and wherein the computer can determine whether an incoming numbered list is present in a numbered list data set by analyzing the hashtables and the wildcard array. 22. The program product of claim 21 wherein the computer is a firewall. 23. The program product of claim 21 wherein the instructions further comprise: obtaining the numbered list data set comprising a plurality of the numbered lists; and wherein the numbered lists comprise a plurality of numbers separated by decimals. 24. The program product of claim 21 wherein the IDs are sequentially increasing powers of two. 25. The program product of claim 21 wherein the quantity of hashtables equals the quantity of numbers in the numbered lists. 26. The program product of claim 21 wherein the instructions further comprise: responsive to the determination that a number is not a wildcard, translating the ID for the numbered list containing the number into a binary ID; and responsive to the determination that the number is not the wildcard, translating a hashtable value with a key equal to the number for the hashtable associated with the number into a binary hashtable value. 27. The program product of claim 21 wherein the instructions further comprise: determining whether a number is a wildcard; responsive to the determination that the number is the wildcard, translating the ID for the numbered list containing the number into a binary ID; and responsive to the determination that the number is the wildcard, translating a wildcard array value associated with the number position into a binary wildcard array value. 28. The program product of claim 21 wherein the instructions further comprise: translating a binary hashtable value into a hexadecimal hashtable value or a decimal hashtable value. 29. The program product of claim 21 wherein the hashtable does not contain any zero values. 30. A program product operable on a computer comprising: a computer-usable medium; wherein the computer usable medium comprises instructions for the computer to perform steps comprising: determining whether a number is the first number in an incoming numbered list; responsive to the determination that the number is the first number in the incoming numbered list, setting a first counter equal to a hashtable value with a key equal to the number; and wherein the computer can determine whether the incoming numbered list is present in the numbered list data set by analyzing the first counter. 31. The program product of claim 30 wherein the computer is a firewall. 32. The program product of claim 30 wherein the instructions further comprise: responsive to the determination that the number is the first number in the incoming numbered list, performing steps comprising: obtaining a wildcard array value with a key equal to the number position; performing a Boolean OR operation on the first counter and the wildcard array value to generate a first result; and setting the first counter equal to the first result. 33. The program product of claim 34 wherein the instructions further comprise: responsive to the determination that the number is the first number in the incoming numbered list, performing steps further comprising: translating the first counter into a binary first counter; translating a wildcard array value with a key equal to the number into a binary wildcard array value; and translating the first result into a hexadecimal first result or a decimal first result. 34. The program product of claim 30 wherein the instructions further comprise: responsive to the determination that the number is not the first number in the incoming numbered list, performing steps comprising: setting a second counter equal to a hashtable value with a key equal to the number; obtaining a wildcard array value with a key equal to the number position; performing a Boolean OR operation on the second counter and the wildcard array value to generate a first result; performing a Boolean AND operation on the first result and the first counter to generate a second result; and setting the first counter equal to the second result. 35. The program product of claim 36 wherein the instructions further comprise: responsive to the determination that the number is not the first number in the incoming numbered list, performing steps further comprising: translating the first counter into a binary first counter; translating the second counter into a binary second counter; translating the wildcard array value into a binary wildcard array value; and translating the second result into a hexadecimal second result or a decimal second result. 36. The program product of claim 30 wherein the instructions further comprise: determining whether the first counter is equal to zero; and responsive to the determination that the first counter is equal to zero, indicating that the incoming numbered list is not present in the numbered list data set. 37. The program product of claim 30 wherein the instructions further comprise: responsive to the determination that the first counter is not equal to zero, indicating that the incoming numbered list is present in the numbered list data set. 38. The program product of claim 37 wherein the quantity of ones present in a binary first counter indicates the location of the match between the incoming numbered list and the numbered list data set. 39. The program product of claim 37 wherein the location of ones present in a binary first counter indicates the number of times the incoming numbered list is present in the numbered list data set. 40. The program product of claim 30 wherein the instructions further comprise: obtaining the incoming numbered list; and obtaining a plurality of numbered list data set hashtables. 41. The program product of claim 30 wherein the incoming numbered list comprises a plurality of numbers separated by decimals. 42. The program product of claim 30 wherein the instructions further comprise: determining whether the number is a wildcard; and responsive to the determination that the number is a wildcard, performing a Boolean OR operation between the first counter and a value equal to sum of the IDs for the numbered lists in the numbered list data set. 43. An apparatus for determining whether an incoming numbered list is present in a numbered list data set, the apparatus comprising: means for obtaining the numbered list data set comprising a plurality of numbered lists; wherein the numbered lists comprise a plurality of numbers separated by decimals; means for assigning a plurality of IDs to the numbered lists; wherein the IDs are sequentially increasing powers of two; means for creating a plurality of arrays; wherein the quantity of arrays equals the quantity of numbers in the numbered lists; wherein the arrays are MAXV fields long, MAXV being the maximum value of any number in the numbered lists or an incoming numbered list; means for determining whether one of the numbers is a wildcard; responsive to the determination that the number is the wildcard, means for translating the ID for the numbered list containing the number into a binary ID; responsive to the determination that the number is the wildcard, means for translating a plurality of array values for the array associated with the number into a plurality of binary array values; responsive to the determination that the number is not the wildcard, means for translating the ID for the numbered list containing the number into the binary ID; responsive to the determination that the number is not the wildcard, means for translating the array value with an index equal to the number for the array associated with the number into the binary array value; means for performing a Boolean OR operation on the ID and the array value; means for translating the binary array values into a hexadecimal array value or a decimal array value; means for obtaining the incoming numbered list; wherein the incoming numbered list comprises the plurality of numbers separated by decimals; means for determining whether a number is the first number in the incoming numbered list; responsive to the determination that the number is the first number in the incoming numbered list, means for setting a counter equal to the array value with the index equal to the number; responsive to the determination that the number is not the first number in the incoming numbered list, the apparatus further comprises: means for obtaining the array value with the index equal to the number; means for translating the counter and the array value with the index equal to the number into binary numbers; means for performing a Boolean AND operation to generate a result; means for translating the result into a hexadecimal result or a decimal result; means for setting the counter equal to the result; means for determining whether the counter is equal to zero; responsive to the determination that the counter is equal to zero, means for indicating that the numbered list is not present in the numbered list data set; responsive to the determination that the counter is not equal to zero, means for indicating that the numbered list is present in the numbered list data set; means for determining whether the number is the wildcard; responsive to the determination that the number is the wildcard, means for performing the Boolean OR operation between the counter and a value equal to sum of the IDs for the numbered lists in the numbered list data set; wherein the computer is a firewall; wherein the quantity of ones present in the binary counter indicates the location of the match between the incoming numbered list and the numbered list data set; and wherein the location of ones present in the binary counter indicates the number of times the incoming numbered list is present in the numbered list data set. | FIELD OF THE INVENTION The present invention is directed at an improved method for filtering data packets by determining if an incoming data packet IP address is present in a list of IP addresses. BACKGROUND OF THE INVENTION Every day, countless data packets are transmitted from one computer to another within computer networks. Each data packet contains a source IP address, which is the where the data packet originated. Each data packet also contains a destination IP address, which is the ultimate destination for the data packet. Both IP addresses are a series of numbers separated by decimals, such as 172.168.4.2. A firewall uses the IP addresses to determine whether to permit a data packet to pass through the firewall. A computer network may have dozens of firewalls, each designed to permit or deny certain types of data packets. Because of the large quantity of data packets processed by each firewall, even small improvements in the processing time per data packet can have significant improvements in the overall efficiency of a single firewall, and thus, the computer network as a whole. Similarly, because Internet routers also use IP address filtering as a method for routing data packets, an increase in router efficiency can be realized by an improvement in filtering efficiency. Therefore, a need exists for an improved method for filtering data packet IP addresses. One portion of the IP address filtering process is determining whether the incoming IP address is present in a list of IP addresses. Firewalls can have exclusion lists and/or inclusion lists. In other words, when a firewall receives a data packet, the firewall may determine whether the data packet source IP address is present in a list of allowable data packet IP addresses, determine if the source IP address is present in a list of prohibited data packet IP addresses, or a combination of the two. If the IP address is present in the list of allowable IP addresses and not in the list of prohibited IP addresses, the firewall permits the data packet to pass through the firewall. Otherwise, the firewall denies the data packet passage past the firewall. Thus, the firewall must determine whether an incoming numbered list (i.e. a destination IP address) is present in a numbered list data set (i.e. a list of IP addresses), regardless of whether the numbered list data set is allowable or prohibited numbered lists. For example, the firewall determines whether the incoming numbered list 1.3.2.4 is present in the numbered list data set 1.2.3.4, 1.4.3.2, 1.2.2.2, 1.3.2.4, and 4.2.3.6. The prior art method for determining whether the incoming numbered list is present in a numbered list data set is to create a tree containing all of the numbered lists in the numbered list data set. An example of a prior art tree for the numbered list data set above is illustrated in FIG. 1. In the prior art tree, each level represents a number position. At each level, the firewall makes a determination whether the incoming numbered list matches any of the numbers at that level. If the incoming numbered list matches a number in the tree, then the firewall proceeds to the next level. If the incoming numbered list does not match a number, the incoming numbered list is not present in the numbered list data set. The comparison process continues until the firewall reaches the last level of the tree. Thus, by comparing an incoming numbered list to the tree, a firewall can determine whether an incoming numbered list is present in the numbered list data set. One of the problems with the tree method for determining whether an incoming numbered list is present in a numbered list data set is that any of the numbered lists from the numbered list data set may contain a wildcard character. A wildcard character is a keyboard character that can be used to represent one or many characters. For example, the asterisk (*) typically represents one or more characters and the question mark (?) typically represents a single character. When a numbered list from the numbered list data set contains a wildcard character, there is at least one level of recursion in the process of determining whether an incoming numbered list is present in the numbered list data set. In other words, at each level in the tree, the firewall must make two determinations: whether any of the nodes represent a wildcard and whether the incoming numbered list matches any of the nodes. If a level contains a matching node and a wildcard node, then the firewall must traverse two paths down from that level. The presence of a wildcard at a lower level would create even more paths for the firewall to trace. Thus, wildcards in the tree lead to an increasing amount of computational steps and an undesirable increase in the time required to determine whether an incoming numbered list is present in a numbered list data set. Consequently, a need exists in the art for an improved method for determining whether an incoming numbered list is present in a numbered list data set. Moreover, a need exists in the art for a method for determining whether an incoming numbered list is present in a numbered list data set that does not require extra computational steps when the numbered list data set contains a wildcard character. Finally, a need exists for a method for determining whether an incoming numbered list is present in a numbered list data set in which the method eliminates the need for recursive computational sets. SUMMARY OF THE INVENTION The present invention, which meets the needs identified above, is an improved method for filtering data packets through a firewall. The method improves over the prior art by allowing a firewall to determine whether an incoming numbered list is present in a numbered list data set in less time than the prior art methods. The present invention is particularly preferable when the numbered list data set and/or the incoming numbered list contain a wildcard character. The software embodiment of the present invention comprises an Array Creation Program (ACP) and an Array Matching Program (AMP). The ACP assigns an ID to each of the numbered lists in the numbered list data set. The ID is a sequentially increasing power of two (i.e. 20=1, 21=2, 22=4, 23=8, 24=16 . . . ). The ACP then creates a plurality of arrays from the numbered list data set. The ACP modifies the array values based on the numbers in the numbered lists. The ACP only has to create the arrays when the firewall associated with the present invention receives an updated or modified numbered list data set. When the firewall associated with the present invention receives an incoming numbered list, the AMP analyzes the numbers in the incoming numbered list to determine the hexadecimal values in the array fields associated with the numbers in the incoming numbered list. The AMP uses a counter and a Boolean AND operation to compare the incoming numbered list to the arrays. If the counter ever becomes zero, the AMP indicates that there is no match. After the processing is complete, a non-zero counter indicates that the incoming numbered data list is present in the numbered list data set. The location and quantity of ones (1) present in the binary version of the counter indicates the location of the match and the number of times the incoming numbered list is present in the numbered list data set. The present invention also includes a Hashtable Creation Program (HCP) and a Hashtable Matching Program (HMP). The HCP is similar to the ACP, with the exception that the HCP creates hashtables instead of arrays for the numbered list data set. The HCP also creates a wildcard array. Hashtables utilize less memory than arrays when there is a large quantity of numbered lists in the numbered list data set. For example, hashtables would be preferable to arrays when processing IPv6 addresses (version 6 IP addresses), which range from zero (0) to 232 (4,294,967,296). However, arrays would be preferable to hashtables when processing IPv4 (version 4 IP addresses, which range from zero (0) to two hundred fifty five (255). The HMP operates similarly to the AMP, but uses two counters to compare the incoming numbered list to the hashtables and the wildcard hashtable. If the first counter becomes zero, the HMP indicates that there is no match. After the processing is complete, a non-zero counter indicates that the incoming numbered data list is present in the numbered list data set. The location and quantity of ones (1) present in the binary version of the counter indicates the location of the match and the number of times the incoming numbered list is present in the numbered list data set. BRIEF DESCRIPTION OF THE DRAWINGS The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: FIG. 1 is an illustration of a prior art numbered list data set tree; FIG. 2 is an illustration of a firewall and computer network of the present invention; FIG. 3 is an illustration of a firewall, including a memory and a processor, associated with the present invention; FIG. 4 is an illustration of the logic of the Array Creation Program (ACP) of the present invention; FIG. 5 is an illustration of the numbered list data set and the IDs assigned with each of the numbered lists in the numbered list data set of the present invention; FIG. 6 is an illustration of the arrays created by the ACP of the present invention; FIG. 7 is an illustration of the logic of the Array Matching Program (AMP) of the present invention; FIGS. 8A and 8B illustrate the calculations that the AMP performs when processing an incoming numbered list; FIG. 9 is an illustration of the logic of the Hashtable Creation Program (HCP) of the present invention; FIG. 10 is an illustration of the hashtables created by the HCP of the present invention; FIG. 11 is an illustration of an example of the wildcard array of the present invention; FIG. 12 is an illustration of the logic of the Hashtable Matching Program (HMP) of the present invention; and FIGS. 13A and 13B illustrate the calculations that the HMP performs when processing an incoming numbered list. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As used herein, the term “array” shall mean a data construct comprising a plurality of fields referenced by indexes, in which each field stores a value such as a binary, decimal, or hexadecimal number. As used herein, the term “computer” shall mean a machine having a processor, a memory, and an operating system, capable of interaction with a user or other computer, and shall include without limitation firewalls, desktop computers, notebook computers, tablet personal computers, personal digital assistants (PDAs), servers, handheld computers, and similar devices. As used herein, the term “field” shall mean an individual element within an array or a hashtable. As used herein, the term “hashtable” shall mean a data construct comprising a plurality of fields referenced by keys, in which each field stores a value such as a binary, decimal, or hexadecimal number. As used herein, the term “ID” shall mean an integer assigned to one of the numbered lists in a numbered list data set, wherein the ID is calculated by raising a fixed base number to a sequentially increasing power. The fixed base is typically two. The sequentially increasing power starts with zero and continues until each numbered list in the numbered list data set has been assigned an ID. As used herein, the term “incoming numbered list” shall mean a numbered list that is compared to a numbered list data set. The present invention determines whether the incoming numbered list is present in the numbered list data set. As used herein, the term “index” shall mean an integer or other character that allows direct access into an array without the need for a sequential search through the collection of fields. As used herein, the term “key” shall mean an integer or other character that allows direct access into a hashtable without the need for a sequential search through the collection of fields. As used herein, the term “MAXV” shall mean the maximum value of a number in a numbered list in a numbered list data set or an incoming numbered list. MAXV is chosen by a person of ordinary skill in the art such as an administrator of the present invention. As used herein, the term “number” shall mean one of a plurality of integers separated by decimals in a numbered list. As used herein, the term “numbered list” shall mean a plurality of numbers separated by decimals. A common example of a numbered list is an IP address. As used herein, the term “numbered list data set” shall mean a plurality of numbered lists. The present invention determines whether the incoming numbered list is present in the numbered list data set. As used herein, the term “recursion” shall mean the need to perform a plurality of similar computational steps from a single decision point in a computer program. Recursion is generally not preferable because of the increased computational time and increased probability of error. As used herein, the term “translate” shall mean to convert between different bases for a number such as the binary, decimal, and hexadecimal bases. As used herein, the term “value” shall mean the field entry from an array or hashtable. As used herein, the term “wildcard” shall mean a keyboard character that can be used to represent one or many characters. The asterisk (*) typically represents one or more characters and the question mark (?) typically represents a single character. As used herein, the term “wildcard array” shall mean an array or hashtable created to identify the location of wildcards in a numbered list data set. FIG. 2 is an illustration of computer network 90 associated with the present invention. Computer network 90 comprises local computer 95 electrically coupled to network 96 through firewall 92. Local computer 95 is electrically coupled to remote computer 94 and remote computer 93 via network 96 and firewall 92. Local computer 95 is also electrically coupled to server 91 via network 96 and firewall 92. Network 96 may be a simplified network connection such as a local area network (LAN) or may be a larger network such as a wide area network (WAN) or the Internet. Furthermore, computer network 90 depicted in FIG. 2 is intended as a representation of a possible operating network containing the present invention and is not meant as an architectural limitation. The internal configuration of a firewall, including connection and orientation of the processor, memory, and input/output devices, is well known in the art. The present invention may be a method, a stand alone firewall program, or a plug-in to an existing firewall program. Persons of ordinary skill in the art are aware of how to configure firewall programs, such as those described herein, to plug into an existing firewall program. Referring to FIG. 3, the methodology of the present invention is implemented on software by Array Creation Program (ACP) 200, Array Matching Program (AMP) 300, Hashtable Creation Program (HCP) 400, and Hashtable Matching Program (HMP) 500. ACP 200, AMP 300, HCP 400, and HMP 500 described herein can be stored within the memory of any firewall depicted in FIG. 2. Alternatively, ACP 200, AMP 300, HCP 400, and HMP 500 can be stored in an external storage device such as a removable disk, a CD-ROM, or a USB storage device. Memory 100 is illustrative of the memory within the firewall of FIG. 2. Memory 100 also contains numbered list data set 120, incoming numbered list 140, numbered list data set array 160, numbered list data set hashtables 180, and wildcard array 190. Numbered list data set 120 is a database or computer file containing a plurality of numbered lists. Each numbered list comprises a plurality of numbers separated by decimals. Incoming numbered list 140 is a numbered list that needs to be routed to another computer. Incoming numbered list 140 is similar to the numbered lists in numbered list data set 120. Numbered list data set arrays are a plurality of arrays created by ACP 200 of the present invention. Numbered list data set hashtables 180 are a plurality of hashtables created by HCP 400 of the present invention. Wildcard array 190 is an array that identifies the location of wildcards in the numbered list data set when HCP 400 creates hashtables 180. As part of the present invention, memory 100 can be configured with numbered list data set 120, incoming numbered list 140, numbered list data set array 160, numbered list data set hashtables 180, wildcard array 190, ACP 200, AMP 300, HCP 400, and/or HMP 500. Processor 106 can execute the instructions contained in ACP 200, AMP 300, HCP 400, and/or HMP 500. Processor 106 and memory 100 are part of a firewall such as firewall 92 in FIG. 2. Processor 106 can communicate with local computer 95 or other computers via network 96. In alternative embodiments, numbered list data set 120, incoming numbered list 140, numbered list data set array 160, numbered list data set hashtables 180, wildcard array 190, ACP 200, AMP 300, HCP 400, and/or HMP 500 can be stored in the memory of computers. Storing numbered list data set 120, incoming numbered list 140, numbered list data set array 160, numbered list data set hashtables 180, wildcard array 190, ACP 200, AMP 300, HCP 400, and/or HMP 500 in the memory of computers allows the processor workload to be distributed across a plurality of processors instead of a single processor. Further configurations of numbered list data set 120, incoming numbered list 140, numbered list data set array 160, numbered list data set hashtables 180, wildcard array 190, ACP 200, AMP 300, HCP 400, and/or HMP 500 across various memories are known by persons of ordinary skill in the art. The present invention utilizes binary (base 2), decimal (base 10), and hexadecimal (base 16) numbers in its calculations. Each group of numbers is useful for specific purposes. For example, binary numbers are useful for performing Boolean operations. Decimal numbers are useful for humans to comprehend. Hexadecimal numbers are useful because computers process bytes (eight bits), which can be represented by a two digit hexadecimal number. In order to avoid confusion between hexadecimal and decimal numbers, hexadecimal numbers are followed by an H or preceded by &, $, or 0x. Table 1 below summarizes the translation between decimal numbers 0 through 5 and their binary and hexadecimal counterparts. TABLE 1 Decimal (Base 10) Binary (Base 2) Hexadecimal (Base 16) 00 0000 0 × 0 01 0001 0 × 1 02 0010 0 × 2 03 0011 0 × 3 04 0100 0 × 4 05 0101 0 × 5 06 0110 0 × 6 07 0111 0 × 7 08 1000 0 × 8 09 1001 0 × 9 10 1010 0 × A 11 1011 0 × B 12 1100 0 × C 13 1101 0 × D 14 1110 0 × E 15 1111 0 × F Persons of ordinary skill in the art are aware of how to translate between decimal, binary, and hexadecimal numbers. When performing Boolean operations between binary numbers, the ones (1) represent true fields and the zeros (0) represent false fields. A Boolean AND operation determines whether all of the elements in a set are true. The results of the four different combinations of the Boolean AND operation are presented in Table 2 below. TABLE 2 a b a AND b 0 (False) 0 (False) 0 (False) 0 (False) 1 (True) 0 (False) 1 (True) 0 (False) 0 (False) 1 (True) 1 (True) 1 (True) Thus, in a Boolean AND operation, the result will be false unless all of the elements of the operation are true. The Boolean AND operation is valid for any number of elements. Similarly, a Boolean OR operation determines whether any of the elements in a set are true. The results of the four different combinations of the Boolean OR operation are presented in Table 3 below. TABLE 3 a b a OR b 0 (False) 0 (False) 0 (False) 0 (False) 1 (True) 1 (True) 1 (True) 0 (False) 1 (True) 1 (True) 1 (True) 1 (True) Thus, in a Boolean OR operation, the result will be true unless all of the elements of the operation are false. The Boolean OR operation is valid for any number of elements. FIG. 4 is an illustration of the logic of Array Creation Program (ACP) 200 of the present invention. ACP 200 is a firewall program that creates a plurality of arrays from a numbered list data set. ACP 200 starts (202) whenever the firewall receives a new or updated numbered list data set. ACP 200 obtains the new or updated numbered list data set (204). The numbered list data set may be like numbered list data set 120 depicted in FIG. 3. ACP 200 then assigns IDs to the numbered lists (206). The ID values are sequentially increasing powers of two. For example, the first numbered list is assigned an ID of one (20=1), the second numbered list is assigned an ID of two (21=2), the third numbered list is assigned an ID of four (22=4) and so forth until every numbered list has been assigned an ID. FIG. 5 illustrates an example of a numbered list data set with IDs assigned to each numbered list. ACP 200 then creates a list of indexes and arrays (208). ACP 200 creates a number of arrays equal to the quantity of numbers in the numbered lists in the numbered list data set. For example, if the numbered list data set contains numbered lists with four numbers (i.e. 1.2.3.4), then ACP 200 creates four arrays. Each array is one field wide and MAXV fields long, where MAXV is the maximum value of a number in a numbered list in a numbered list data set or an incoming numbered list. MAXV is a number chosen by a person of ordinary skill in the art such as an administrator of the present invention. FIG. 6 illustrates an example of the arrays for a numbered list data set with four numbers and a MAXV of fifteen. ACP 200 then proceeds to the first numbered list in the numbered list data set (210). ACP 200 processes the numbered list in an orderly method. Generally, the numbered lists are presented horizontally with each numbered list on a separate line. Therefore, when proceeding from one numbered list to another, ACP 200 proceeds to the numbered list on the next line. Persons of ordinary skill in the art are aware of other methods for processing the numbered lists. ACP 200 also proceeds to the first array (212). The array may be like numbered list data set array 160 illustrated in FIG. 3. ACP 200 processes the arrays in an orderly method. ACP 200 generally starts at the leftmost array and proceeds to the next array on the right. Persons of ordinary skill in the art are aware of other methods for processing the arrays. ACP 200 proceeds to the first number in the numbered list (214). ACP 200 also processes the numbers in an orderly method. ACP 200 generally starts at the leftmost number and proceeds to the next number on the right. Persons of ordinary skill in the art are aware of other methods for processing the numbers within a numbered list. ACP 200 then determines whether the number is a wildcard (216). If ACP 200 determines that the number is a wildcard, then ACP 200 performs a Boolean OR operation on the ID and every array value for the present array (220). In other words, at step 220 the number of Boolean OR operations will equal the number of array values in the present array. ACP 200 then proceeds to step 228. If at step 216, ACP 200 determines that the number is not a wildcard, then ACP 200 performs a Boolean OR operation on the ID and the array value with an index equal to the number (224). In other words, at step 224 ACP 200 performs only one Boolean OR operation in the present array. ACP 200 then proceeds to step 228. At step 228, ACP 200 determines whether there are numbers remaining in the present numbered list (228). If ACP 200 determines that there are numbers remaining in the numbered list, then ACP 200 proceeds to the next number in the numbered list (230) and the next array (232) and returns to step 216. The next number in a numbered list is the leftmost number that has not been processed by steps 216 through 226. The next array is the leftmost array that has not been processed by steps 216 through 226. If at step 228 ACP 200 determines that there are not any numbers remaining in the present numbered list, then ACP 200 determines whether there are any numbered lists remaining (234). If ACP 200 determines that there are numbered lists remaining, then ACP 200 proceeds to the next numbered list in the numbered list data set (236). The next numbered list is the highest numbered list that has not been processed by steps 212 through 232. ACP 200 then returns to step 212. If at step 234 ACP 200 determines that there are not any numbered lists remaining, then ACP 200 ends (238). FIG. 6 illustrates the arrays created by ACP 200. FIG. 5 is an illustration of the IDs assigned to the numbered lists in the numbered list data set. The numbered lists from the numbered list data set are depicted in column 282. The IDs assigned to the numbered lists are depicted in column 284. FIG. 6 is an illustration of the arrays created by ACP 200. FIG. 6 contains index 286 for the arrays. Array 288 is the array for the first number in the numbered list. Array 290 is the array for the second number in the numbered list. Array 292 is the array for the third number in the numbered list. Array 294 is the array for the fourth number in the numbered list. The numbers in the array fields in FIG. 6 containing the “Ox” prefix are hexadecimal numbers. FIG. 7 illustrates the logic of Array Matching Program (AMP) 300. AMP 300 is a firewall program that determines whether an incoming numbered list is present in a numbered list data set array by analyzing array values associated with the numbers in the incoming numbered list. Persons of ordinary skill in the art are aware of how to configure AMP 300 such that it will only indicate a match if the incoming numbered list contains the same quantity of numbers as the numbered lists in the numbered list data set. In other words, AMP 300 does not return a match for the incoming numbered list 1.2.3 when the numbered list data set is 1.2.3.4, 1.2.*.5, 1.1.3.4, and *.*.5.4. AMP 300 starts (302) whenever the firewall running the present invention receives an incoming numbered list. AMP 300 obtains the incoming numbered list (304). The incoming numbered list may be like incoming numbered list 140 depicted in FIG. 3. AMP 300 then obtains the numbered list data set arrays created by ACP 200 (306). AMP 300 then proceeds to the first number in the incoming numbered list (308) and the first array (310). The numbers in the incoming numbered list are processed similar to the numbers in the numbered lists in the numbered list data set in ACP 200. The arrays are also processed similar to the arrays in ACP 200. AMP 300 then proceeds to step 312. At step 312, AMP 300 determines whether the present number in the incoming numbered list is the first number in the numbered list (312). If AMP 300 determines that the present number in the incoming numbered list is the first number in the numbered list, then AMP 300 sets the counter equal to the present array value with an index equal to the present number (314). AMP 300 then proceeds to step 324. If at step 312 AMP 300 determines that the present number in the incoming numbered list is not the first number in the numbered list, then AMP 300 obtains the present array value with an index equal to the present number (316). AMP 300 then performs a Boolean AND operation on the counter and the value from step 316, generating a new counter (320). In other words, the counter is set equal to the hexadecimal result of the Boolean AND operation. AMP 300 then proceeds to step 324. At step 324, AMP 300 determines whether the counter is equal to zero (324). If AMP 300 determines that the counter is equal to zero, then AMP 300 indicates that the incoming numbered list is not present in the numbered list data set (334) and ends (336). If AMP 300 determines that the counter is not equal to zero, then AMP 300 determines whether there are numbers remaining in the incoming numbered list (326). If AMP 300 determines that there are numbers remaining in the incoming numbered list, then AMP 300 proceeds to the next number in the incoming numbered list (328). AMP 300 then proceeds to the next array (330) and returns to step 312. If at step 326 AMP 300 determines that there are not any numbers remaining in the incoming numbered list, then AMP 300 indicates that the incoming numbered list is present in the numbered list data set (332) and ends (336). In an alternative embodiment, AMP 300 counts the quantity of ones (is) present in the binary version of the counter when AMP 300 ends. The location and quantity of ones (1) present in the binary version of the counter indicates the location of the match and the number of times the incoming numbered list is present in the numbered list data set. FIGS. 8A and 8B illustrate the calculations AMP 300 performs in processing the incoming numbered list. The incoming numbered list is depicted vertically in column 382. In FIG. 8A the incoming numbered list is 1.2.6.5 and in FIG. 8B the incoming numbered list is 2.3.2.5. The array values depicted in column 384 are calculated in steps 314 and 316 of AMP 300 and are values from the array depicted in FIG. 6. The counters depicted in column 386 are the counter values at step 312 of AMP 300. The counters depicted in column 388 are the counter values at step 324 of AMP 300. When a counter equals zero at step 324, AMP 300 does not need to process the remaining numbers in the numbered list because the incoming numbered list is not present in the numbered list data set. A hashtable is a data construct that stores a set of items. Hashtables utilize less memory than arrays when there is a large quantity of numbered lists in the numbered list data sets. Each item in the hashtable has a key that identifies the item. Items are found, added, and removed from the hashtable by using the key. Table 4 outlines the differences between arrays and hashtables. TABLE 4 Array Hashtable Indexes/ Integer: arrays are Any type: almost any data type can Keys always indexed on be used as key, including strings, integers, and must be integers, XPCOM contiguous. interface pointers, IIDs, and almost anything else. Keyes can be disjunctive (i.e. you can store entries with keys 1, 5, and 3000). Lookup Lookup time is a Lookup time is mostly-constant, but Time simple constant. the constant time can be larger than an array lookup Sorting Sorted: stored sorted; Unsorted: stored unsorted; enumerated in a sorted cannot be enumerated in a fashion. sorted manner. Inserting/ Adding and removing Adding and removing items from Removing items from a large hashtables is a quick operation. array can be time- consuming. Wasted None: Arrays are Some: hashtables are not packed Space packed structures, so structures; depending on the imple- there is no wasted mentation, there may be significant space. wasted memory. In their implementation, hashtables take the key and apply a mathematical hash function to “randomize” the keys and then use the hash to find the location in the hashtable. Good hashtable implementations will automatically resize the hashtable in memory if extra space is needed, or if too much space has been allocated. Hashtables are useful for: sets of data that need swift random access, with non-integral keys or non-contiguous integral keys, or where items will be frequently added or removed. Hashtables should not be used for: sets that need to be sorted, very small datasets (less than sixteen items), or data that does not need random access. In these situations, an array is more efficient. For example, hashtables would be referable to arrays when processing IPv6 addresses (version 6 IP addresses), which range from zero (0) to 232. However arrays would be referable to hashtables when processing IPv4 (version 4 IP addresses, which range from zero (0) to two hundred fifty five (255). FIGS. 9 through 13 illustrate the present invention utilizing hashtables instead of arrays. FIG. 9 is an illustration of the logic of Hashtable Creation Program (HCP) 400 of the present invention. HCP 400 is a firewall program that creates a plurality of hashtables from a numbered list data set. HCP 400 starts (402) whenever the firewall receives a new or updated numbered list data set. HCP 400 obtains the new or updated numbered list data set (404). The numbered list data set may be like numbered list data set 140 depicted in FIG. 3. HCP 400 then assigns IDs to the numbered lists (406). The ID values are sequentially increasing powers of two. For example, the first numbered list is assigned an ID of one (20=1), the second numbered list is assigned an ID of two (21=2), the third numbered list is assigned an ID of four (22=4) and so forth until every numbered list has been assigned an ID. FIG. 5 illustrates an example of a numbered list data set with IDs assigned to each numbered list. HCP 400 then creates a list of keys and hashtables (408). HCP 400 creates a number of hashtables equal to the quantity of numbers in the numbered lists in the numbered list data set. For example, if the numbered list data set contains numbered lists with four numbers (i.e. 1.2.3.4), then HCP 400 creates four hashtables. Each hashtable is one field wide contains a key for each number present in that particular number position. The hashtables ignore the wildcard characters. For example, if the numbered list data set is 1.2.3.4, 1.2.*.5, 1.1.3.4, and *.*.5.4, then the first hashtable would only have a key of one because the first number position does not contain any other numbers but one. FIG. 10 illustrates an example of the hashtables for a numbered list data set from FIG. 5. HCP 400 then creates the wildcard array (409). The wildcard array may be like wildcard array 190 depicted in FIG. 3. The wildcard array is a single array with the same quantity of fields as the quantity of numbers in the numbered list data set. Each index in the wildcard array refers to a position in the numbered list data set (i.e. index one refers to the first position. An example of a wildcard array is illustrated in FIG. 11. HCP 400 then proceeds to the first numbered list in the numbered list data set (410). HCP 400 processes the numbered list in an orderly method. Generally, the numbered lists are presented horizontally with each numbered list on a separate line. Therefore, when proceeding from one numbered list to another, HCP 400 proceeds to the numbered list on the next line. Persons of ordinary skill in the art are aware of other methods for processing the numbered lists. HCP 400 also proceeds to the first hashtable (412). The hashtable may be like numbered list data set hashtable 160 illustrated in FIG. 3. HCP 400 processes the hashtables in an orderly method. HCP 400 generally starts at the leftmost hashtable and proceeds to the next hashtable on the right. Persons of ordinary skill in the art are aware of other methods for processing the hashtables. HCP 400 proceeds to the first number in the numbered list (414). HCP 400 also processes the numbers in an orderly method. HCP 400 generally starts at the leftmost number and proceeds to the next number on the right. Persons of ordinary skill in the art are aware of other methods for processing the numbers within a numbered list. HCP 400 then determines whether the number is a wildcard (416). If HCP 400 determines that the number is a wildcard, then HCP 400 performs a Boolean OR operation on the ID and the wildcard array value with an index equal to the present number position (420). In other words, at step 440 HCP 400 performs only one Boolean OR operation in the present array. If HCP 400 is processing the first number in a numbered list, then the number position is one. HCP 400 then proceeds to step 428. If at step 416, HCP 400 determines that the number is not a wildcard, then HCP 400 performs a Boolean OR operation on the ID and the hashtable value with a key equal to the number (424). In other words, at step 424 HCP 400 performs only one Boolean OR operation in the present array. HCP 400 then proceeds to step 428. At step 428, HCP 400 determines whether there are numbers remaining in the present numbered list (428). If HCP 400 determines that there are numbers remaining in the numbered list, then HCP 400 proceeds to the next number in the numbered list (430) and the next hashtable (432) and returns to step 416. The next number in a numbered list is the leftmost number that has not been processed by steps 416 through 426. The next hashtable is the leftmost hashtable that has not been processed by steps 416 through 426. If at step 428 HCP 400 determines that there are not any numbers remaining in the present numbered list, then HCP 400 determines whether there are any numbered lists remaining (434). If HCP 400 determines that there are numbered lists remaining, then HCP 400 proceeds to the next numbered list in the numbered list data set (436). The next numbered list is the highest numbered list that has not been processed by steps 412 through 432. HCP 400 then returns to step 412. If at step 434 HCP 400 determines that there are not any numbered lists remaining, then HCP 400 ends (438). FIG. 10 illustrates the hashtables created by HCP 400. FIG. 10 is an illustration of the hashtables created by HCP 400. FIG. 10 contains key 480 for the hashtables. Each hashtable only has a key for the non-zero values within the hashtable. Thus, in some cases, the hashtable consumes less memory than the arrays. Hashtable 482 is the hashtable for the first number in the numbered list. Hashtable 484 is the hashtable for the second number in the numbered list. Hashtable 486 is the hashtable for the third number in the numbered list. Hashtable 488 is the hashtable for the fourth number in the numbered list. The numbers in the hashtable fields in FIG. 10 containing the “Ox” prefix are hexadecimal numbers. FIG. 11 illustrates the wildcard array created by HCP 400. Index 490 indicates the position of the wildcards in the numbered list data set. Array 492 indicates the value of the wildcard associated with the position indicated by index 490. FIG. 12 illustrates the logic of Hashtable Matching Program (HMP) 500. HMP 500 is a firewall program that determines whether an incoming numbered list is present in a numbered list data set hashtable by analyzing hashtable values associated with the numbers in the incoming numbered list. Persons of ordinary skill in the art are aware of how to configure HMP 500 such that it will only indicate a match if the incoming numbered list contains the same quantity of numbers as the numbered lists in the numbered list data set. In other words, HMP 500 does not return a match for the incoming numbered list 1.2.3 when the numbered list data set is 1.2.3.4, 1.2.*.5, 1.1.3.4, and *.*.5.4. HMP 500 starts (502) whenever the firewall running the present invention receives an incoming numbered list. HMP 500 obtains the incoming numbered list (504). The incoming numbered list may be like incoming numbered list 140 depicted in FIG. 3. HMP 500 then obtains the numbered list data set hashtables created by HCP 400 (506). HMP 500 then proceeds to the first number in the incoming numbered list (508) and the first hashtable (510). The numbers in the incoming numbered list are processed similar to the numbers in the numbered lists in the numbered list data set in HCP 400. The hashtables are also processed similar to the hashtables in HCP 400. HMP 500 then proceeds to step 512. At step 512, HMP 500 determines whether the present number in the incoming numbered list is the first number in the numbered list (512). If HMP 500 determines that the present number in the incoming numbered list is the first number in the numbered list, then HMP 500 sets the first counter equal to the present hashtable value with a key equal to the present number (514). HMP 500 obtains the wildcard array value with an index equal to the present number position (i.e. the first number) (516). HMP 500 then performs a Boolean OR operation on the first counter and the value from step 516, generating a new first counter (520). In other words, the first counter is set equal to the hexadecimal result of the Boolean OR operation. HMP 500 then proceeds to step 536. If at step 512 HMP 500 determines that the present number in the incoming numbered list is not the first number in the numbered list, then HMP 500 sets the second counter equal to the present hashtable value with an key equal to the present number (524). HMP 500 obtains the wildcard array value with an index equal to the present number position (i.e. the second, third, or forth number) (526). HMP 500 then performs a Boolean OR operation on the second counter and the value from step 526, generating a first result (530). HMP 500 then performs a Boolean AND operation on the first result and the first counter, generating a new first counter (532). In other words, the first counter is set equal to the second hexadecimal result of the Boolean AND operation. HMP 500 then proceeds to step 536. At step 536, HMP 500 determines whether the first counter is equal to zero (536). If HMP 500 determines that the first counter is equal to zero, then HMP 500 indicates that the incoming numbered list is not present in the numbered list data set (544) and ends (548). If HMP 500 determines that the first counter is not equal to zero, then HMP 500 determines whether there are numbers remaining in the incoming numbered list (538). If HMP 500 determines that there are numbers remaining in the incoming numbered list, then HMP 500 proceeds to the next number in the incoming numbered list (540). HMP 500 then proceeds to the next hashtable (542) and returns to step 512. If at step 538 HMP 500 determines that there are not any numbers remaining in the incoming numbered list, then HMP 500 indicates that the incoming numbered list is present in the numbered list data set (546) and ends (548). In an alternative embodiment, HMP 500 counts the quantity of ones (Is) present in the binary version of the counter when HMP 500 ends. The location and quantity of ones (1) present in the binary version of the counter indicates the location of the match and the number of times the incoming numbered list is present in the numbered list data set. FIGS. 13A and 13B illustrate the calculations HMP 500 performs in processing the incoming numbered list. The incoming numbered list is depicted vertically in column 580. In FIG. 13A the incoming numbered list is 1.2.6.5 and in FIG. 13B the incoming numbered list is 2.5.2.5. The hashtable values depicted in column 582 are calculated in steps 514 and 524 of HMP 500 and are values from the hashtable depicted in FIG. 10. The wildcard array values depicted in column 584 are calculated in steps 516 and 526 of HMP 500 and are values from the wildcard array depicted in FIG. 11. The first counters depicted in column 586 are the first counter values at step 512 of HMP 500. The second counters depicted in column 588 are the counter values at step 524 of HMP 500. The first results depicted in column 590 are the first result values calculated at steps 520 and 530 of HMP 500. The second results depicted in column 592 are the second result values calculated at step 532 of HMP 500. The first counters depicted in column 594 are the first counter values at step 536 of HMP 500. When a counter equals zero at step 536, HMP 500 does not need to process the remaining numbers in the numbered list because the incoming numbered list is not present in the numbered list data set. Persons of ordinary skill in the art will appreciate that the present invention may be configured to process incoming numbered lists that contain wildcard characters. If an incoming numbered list contains a wildcard character, a person of ordinary skill in the art could modify AMP 300 or HMP 500 to recognize the wildcard character. Upon recognition of the wildcard character, the present invention would perform a Boolean OR operation between the counter (in the case of AMP 300) or the first counter (in the case of HMP 500) and a value equal to sum of the IDs for the numbered lists in the numbered list data set (i.e. decimal 15 or binary 1111 in the example presented herein). The Boolean OR operation would be performed prior to determining if the counter or first counter is equal to zero. With respect to the above description, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function, manner of operation, assembly, and use are deemed readily apparent and obvious to one of ordinary skill in the art. The present invention encompasses all equivalent relationships to those illustrated in the drawings and described in the specification. The novel spirit of the present invention is still embodied by reordering or deleting some of the steps contained in this disclosure. The spirit of the invention is not meant to be limited in any way except by proper construction of the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Every day, countless data packets are transmitted from one computer to another within computer networks. Each data packet contains a source IP address, which is the where the data packet originated. Each data packet also contains a destination IP address, which is the ultimate destination for the data packet. Both IP addresses are a series of numbers separated by decimals, such as 172.168.4.2. A firewall uses the IP addresses to determine whether to permit a data packet to pass through the firewall. A computer network may have dozens of firewalls, each designed to permit or deny certain types of data packets. Because of the large quantity of data packets processed by each firewall, even small improvements in the processing time per data packet can have significant improvements in the overall efficiency of a single firewall, and thus, the computer network as a whole. Similarly, because Internet routers also use IP address filtering as a method for routing data packets, an increase in router efficiency can be realized by an improvement in filtering efficiency. Therefore, a need exists for an improved method for filtering data packet IP addresses. One portion of the IP address filtering process is determining whether the incoming IP address is present in a list of IP addresses. Firewalls can have exclusion lists and/or inclusion lists. In other words, when a firewall receives a data packet, the firewall may determine whether the data packet source IP address is present in a list of allowable data packet IP addresses, determine if the source IP address is present in a list of prohibited data packet IP addresses, or a combination of the two. If the IP address is present in the list of allowable IP addresses and not in the list of prohibited IP addresses, the firewall permits the data packet to pass through the firewall. Otherwise, the firewall denies the data packet passage past the firewall. Thus, the firewall must determine whether an incoming numbered list (i.e. a destination IP address) is present in a numbered list data set (i.e. a list of IP addresses), regardless of whether the numbered list data set is allowable or prohibited numbered lists. For example, the firewall determines whether the incoming numbered list 1.3.2.4 is present in the numbered list data set 1.2.3.4, 1.4.3.2, 1.2.2.2, 1.3.2.4, and 4.2.3.6. The prior art method for determining whether the incoming numbered list is present in a numbered list data set is to create a tree containing all of the numbered lists in the numbered list data set. An example of a prior art tree for the numbered list data set above is illustrated in FIG. 1 . In the prior art tree, each level represents a number position. At each level, the firewall makes a determination whether the incoming numbered list matches any of the numbers at that level. If the incoming numbered list matches a number in the tree, then the firewall proceeds to the next level. If the incoming numbered list does not match a number, the incoming numbered list is not present in the numbered list data set. The comparison process continues until the firewall reaches the last level of the tree. Thus, by comparing an incoming numbered list to the tree, a firewall can determine whether an incoming numbered list is present in the numbered list data set. One of the problems with the tree method for determining whether an incoming numbered list is present in a numbered list data set is that any of the numbered lists from the numbered list data set may contain a wildcard character. A wildcard character is a keyboard character that can be used to represent one or many characters. For example, the asterisk (*) typically represents one or more characters and the question mark (?) typically represents a single character. When a numbered list from the numbered list data set contains a wildcard character, there is at least one level of recursion in the process of determining whether an incoming numbered list is present in the numbered list data set. In other words, at each level in the tree, the firewall must make two determinations: whether any of the nodes represent a wildcard and whether the incoming numbered list matches any of the nodes. If a level contains a matching node and a wildcard node, then the firewall must traverse two paths down from that level. The presence of a wildcard at a lower level would create even more paths for the firewall to trace. Thus, wildcards in the tree lead to an increasing amount of computational steps and an undesirable increase in the time required to determine whether an incoming numbered list is present in a numbered list data set. Consequently, a need exists in the art for an improved method for determining whether an incoming numbered list is present in a numbered list data set. Moreover, a need exists in the art for a method for determining whether an incoming numbered list is present in a numbered list data set that does not require extra computational steps when the numbered list data set contains a wildcard character. Finally, a need exists for a method for determining whether an incoming numbered list is present in a numbered list data set in which the method eliminates the need for recursive computational sets. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention, which meets the needs identified above, is an improved method for filtering data packets through a firewall. The method improves over the prior art by allowing a firewall to determine whether an incoming numbered list is present in a numbered list data set in less time than the prior art methods. The present invention is particularly preferable when the numbered list data set and/or the incoming numbered list contain a wildcard character. The software embodiment of the present invention comprises an Array Creation Program (ACP) and an Array Matching Program (AMP). The ACP assigns an ID to each of the numbered lists in the numbered list data set. The ID is a sequentially increasing power of two (i.e. 2 0 =1, 2 1 =2, 2 2 =4, 2 3 =8, 2 4 =16 . . . ). The ACP then creates a plurality of arrays from the numbered list data set. The ACP modifies the array values based on the numbers in the numbered lists. The ACP only has to create the arrays when the firewall associated with the present invention receives an updated or modified numbered list data set. When the firewall associated with the present invention receives an incoming numbered list, the AMP analyzes the numbers in the incoming numbered list to determine the hexadecimal values in the array fields associated with the numbers in the incoming numbered list. The AMP uses a counter and a Boolean AND operation to compare the incoming numbered list to the arrays. If the counter ever becomes zero, the AMP indicates that there is no match. After the processing is complete, a non-zero counter indicates that the incoming numbered data list is present in the numbered list data set. The location and quantity of ones (1) present in the binary version of the counter indicates the location of the match and the number of times the incoming numbered list is present in the numbered list data set. The present invention also includes a Hashtable Creation Program (HCP) and a Hashtable Matching Program (HMP). The HCP is similar to the ACP, with the exception that the HCP creates hashtables instead of arrays for the numbered list data set. The HCP also creates a wildcard array. Hashtables utilize less memory than arrays when there is a large quantity of numbered lists in the numbered list data set. For example, hashtables would be preferable to arrays when processing IPv6 addresses (version 6 IP addresses), which range from zero (0) to 2 32 (4,294,967,296). However, arrays would be preferable to hashtables when processing IPv4 (version 4 IP addresses, which range from zero (0) to two hundred fifty five (255). The HMP operates similarly to the AMP, but uses two counters to compare the incoming numbered list to the hashtables and the wildcard hashtable. If the first counter becomes zero, the HMP indicates that there is no match. After the processing is complete, a non-zero counter indicates that the incoming numbered data list is present in the numbered list data set. The location and quantity of ones (1) present in the binary version of the counter indicates the location of the match and the number of times the incoming numbered list is present in the numbered list data set. | 20040210 | 20090519 | 20050811 | 81891.0 | 0 | ARMOUCHE, HADI S | FAST SEARCHING OF LIST FOR IP FILTERING | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,775,652 | ACCEPTED | Unified decoder architecture | Presented herein is a unified decoder architecture. A system comprises a video decoder, instruction memory, and a host processor. The video decoder decodes the video data encoded with the particular standard. The instruction memory stores a first set of instructions and a second set of instructions. The first set of instructions are for decoding encoded video data according to a first encoding standard. The second set of instruction are for decoding encoded video data according to a second encoding standard. The host processor provides an indication to the video decoder indicating the particular encoding standard. The video decoder executes the first set of instructions if the indication indicates that the particular encoding standard is the first encoding standard and executes the second set of instructions if the indication indicates that the particular encoding standard is the second encoding standard. | 1. A system for decoding video data encoded with a particular standard, said system comprising: a video decoder for decoding the video data encoded with the particular standard; instruction memory for storing: a first set of instructions for decoding encoded video data according to a first encoding standard; and a second set of instruction for decoding encoded video data according to a second encoding standard; a host processor for providing an indication to the video decoder indicating the particular encoding standard; and wherein the video decoder executes the first set of instructions if the indication indicates that the particular encoding standard is the first encoding standard and executes the second set of instructions if the indication indicates that the particular encoding standard is the second encoding standard. 2. The system of claim 1, wherein the first encoding standard comprises MPEG-2 and the second encoding standard comprises MPEG-4. 3. The system of claim 1, wherein the instruction memory stores a third set of instructions for decoding encoded video data according to a third encoding standard, and wherein the video decoder executes the third set of instructions if the indication indicates that the particular encoding standard is the third encoding standard. 4. The system of claim 3, wherein the first encoding standard comprises MPEG-2, the second encoding standard comprises MPEG-4, and the third encoding standard comprises DV-25. 5. The system of claim 3, wherein the instruction memory stores a fourth set of instructions for decoding the video data in accordance with the first encoding standard, the second encoding standard, and the third encoding standard. 6. The system of claim 1, further comprising a register for storing the indication from the host processor. 7. The system of claim 6, wherein the instruction memory stores a fifth set of instructions, wherein execution of the instructions by the host processor cause: detecting the particular encoding standard; and writing the indicator to the register. 8. A method for decoding video data encoded with a particular standard, said method comprising: providing an indication to a video decoder indicating the particular encoding standard to the video decoder; executing a first set of instructions if the indication indicates that the particular encoding standard is a first encoding standard; and executing a second set of instructions if the indication indicates that the particular encoding standard is the second encoding standard. 9. The method of claim 8, wherein the first encoding standard comprises MPEG-2 and the second encoding standard comprises MPEG-4. 10. The method of claim 8, further comprising executing the third set of instructions if the indication indicates that the particular encoding standard is the third encoding standard. 11. The method of claim 10, wherein the first encoding standard comprises MPEG-2, the second encoding standard comprises MPEG-4, and the third encoding standard comprises DV-25. 12. The method of claim 10, executing a fourth set of instructions for decoding the video data in accordance with the first encoding standard, the second encoding standard, and the third encoding standard. 13. The method of claim 8, further comprising: detecting the particular encoding standard; and writing the indicator to a register. 14. A system for decoding video data encoded with a particular standard, said system comprising: a code memory for instructions; and a processor for loading the code memory with a first set of instructions for decoding encoded video data according to a first encoding standard, where the video data is encoded according to the first encoding standard and for loading the code memory a second set of instruction for decoding encoded video data according to a second encoding standard, wherein the video data is encoded according to the second encoding standard. 15. The system of claim 14, wherein the processor loads the code memory after receiving an indication from a host processor indicating the particular encoding standard. 16. The system of claim 14, wherein execution of the first set of instructions by the processor controls a first plurality of circuits, and execution of the second set of instructions controls a second plurality of circuits. 17. The system of claim 14, further comprising a slave engine, said slave engine further comprising: another instruction memory for storing a third set of instructions if the encoding standard is the second encoding standard. 18. The system of claim 17, wherein the slave engine comprises a third plurality of circuits, wherein the execution of the third set of instructions controls the third plurality of circuits. | RELATED APPLICATIONS [Not Applicable] FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [Not Applicable] MICROFICHE/COPYRIGHT REFERENCE [Not Applicable] BACKGROUND OF THE INVENTION A number of different standards exist for encoding video data. In some cases, the video data is also compressed as part of the- encoding process. For example, the Motion Pictures Expert Group (MPEG) has devised two such standards commonly known as MPEG-2, and Advanced Video Coding (MPEG-4). Another example of an encoding standard is known as the Digital Video-25 (DV-25). The encoded video data is decoded by a video decoder. However, a video decoder can receive encoded video data that is encoded with any one of a wide variety of encoding standards. In order to display the video data, the video decoder needs to be able to determine and decode video data that is encoded with any one of the wide variety of encoding standards. Although some video decoders are capable of decoding video data from multiple formats, the video decoders comprise special hardware dedicated to decoding each one of the wide variety of encoding standards.-This is disadvantageous because the additional hardware increases the cost of the decoder system. Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with embodiments presented in the remainder of the present application with references to the drawings. BRIEF SUMMARY OF THE INVENTION Presented herein is a unified decoder architecture. In one embodiment, there is presented a system for decoding video data encoded with a particular standard. The system comprises a video decoder, instruction memory, and a host processor. The video decoder decodes the video data encoded with the particular standard. The instruction memory stores a first set of instructions and a second set of instructions. The first set of instructions are for decoding encoded video data according to a first encoding standard. The second set of instruction are for decoding encoded video data according to a second encoding standard. The host processor provides an indication to the video decoder indicating the particular encoding standard. The video decoder executes the first set of instructions if the indication indicates that the particular encoding standard is the first encoding standard and executes the second set of instructions if the indication indicates that the particular encoding standard is the second encoding standard. In another embodiment, there is presented a method for decoding video data encoded with a particular standard. The method comprises providing an indication to a video decoder indicating the particular encoding standard to the video decoder, executing a first set of instructions if the indication indicates that the particular encoding standard is a first encoding standard, and executing a second set of instructions if the indication indicates that the particular encoding standard is the second encoding standard. In another embodiment, there is presented a system for decoding video data encoded with a particular standard. The system comprises a code memory and a processor. The code memory stores instructions. The processor loads the code memory with a first set of instructions for decoding encoded video data according to a first encoding standard, where the video data is encoded according to the first encoding standard and loads the code memory a second set of instruction for decoding encoded video data according to a second encoding standard, wherein the video data is encoded according to the second encoding standard. These and other advantages and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings. BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a block diagram of an exemplary decoder system for decoding compressed video data, in accordance with an embodiment of the present invention; FIG. 2 is a block diagram of a circuit for decoding encoded video data in accordance with an embodiment of the present invention; FIG. 3 is a flow diagram for decoding compressed video data in accordance with an embodiment of the present invention; and FIG. 4 is a block diagram of the video decoder in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1 there is illustrated a block diagram of an exemplary decoder system for decoding compressed video data, in accordance with an embodiment of the present invention. Data is received and stored in a presentation buffer 203 within a Synchronous Dynamic Random Access Memory (SDRAM) 201. The data can be received from either a communication channel or from a local memory, such as, for example, a hard disc or a DVD. In addition, the video data may be compressed using different encoding standards, such as, but not limited to, MPEG-2, DV-25, and MPEG-4. The data output from the presentation buffer 203 is then passed to a data transport processor 205. The data transport processor 205 demultiplexes the transport stream into packetized elementary stream constituents, and passes the audio transport stream to an audio decoder 215 and the video transport stream to a video transport processor 207 and then to an MPEG video decoder 209. The audio data is then sent to the output blocks, and the video is sent to a display engine 211. The display engine 211 scales the video picture, renders the graphics, and constructs the complete display. Once the display is ready to be presented, it is passed to a video encoder 213 where it is converted to analog video using an internal digital to analog converter (DAC). The digital audio is converted to analog in an audio digital to analog converter (DAC) 217. The video decoder 209 can decode encoded video data that is encoded with any one of a plurality of encoding standards. The video decoder 209 uses firmware to decode the encoded video data. A portion of the firmware can be used for decoding video data for each of the plurality of standards, while other portions are specific to a particular standard. Accordingly, the video decoder executes a combination of the portions of the firmware that are common for decoding each of the different standards and the portions that are unique to the specified standard used for encoding the encoded video data. A host processor 290 detects the specific standard used for encoding the encoded video data and provides an indication indicating the specific standard to the video decoder 209. Responsive thereto, the video decoder 209 selects the portions of the firmware that are specific to the encoding standard for execution along with the portions that are common for all of the standards. Referring now to FIG. 2, there is illustrated a block diagram of a circuit for decoding encoded video data in accordance with an embodiment of the present invention. The circuit comprises a video decoder 209, a host processor 290, a first instruction memory 291, and a second instruction memory 292. The first instruction memory 291 stores firmware comprising a first plurality of instructions 295a that are common for decoding encoded video data encoded with any of a plurality of encoding standards, a second plurality of instructions 295b that is unique for decoding encoded video data encoded with a first encoding standard, a third plurality of instructions 295c that is unique for decoding encoded video data encoded with a second encoding standard, a fourth plurality of instructions 295d that is unique for decoding encoded video data encoded with a third encoding standard. The first encoding standard can comprise, for example, MPEG-2. The second encoding standard can comprise, for example, DV-25. The third encoding standard can comprise, for example, MPEG-4. Although the pluralities of instructions 295a, 295b, 295c, 295d are indicated by continuous regions for ease of illustration, it is noted that the pluralities of instructions 295a, 295b, 295c, 295d do not necessarily occupy continuous regions of the first instruction memory 291. The host processor 290 executes instructions stored in the second instruction memory 292. Execution of the instructions in the second instruction memory 292 cause the host processor 290 to detect the encoding standard used for encoding the compressed video data and provide an indicator indicating the encoding standard to the video decoder 209. The video decoder 209 includes a control register 297 comprising a plurality of bits. The host processor 290 includes the encoding standard to the video decoder 209 by setting certain values in one or more of the bits in the control register. For example, in an exemplary case, the host processor 290 can set two bits from the control register 297 to indicate the encoding standard, wherein the value of the two bits indicate the encoding standard as set forth in the table below. Bit Value Encoding Standard 00 Not Used 01 MPEG-2 10 DV-25 11 MPEG-4 Based on the indicated encoding standard, the video decoder 209 selects and executes the portions of the firmware that are specific to the encoding standard for execution along with the portions that are common for the plurality of encoding standards. Referring now to FIG. 3, there is illustrated a flow diagram for decoding compressed video data in accordance with an embodiment of the present invention. At 305, the host processor 290 detects the encoding standard for encoding the encoded video data. After determining the encoding standard for encoding the encoded video data, the host processor 290 provides (310) an indication indicating the encoding standard to the video decoder 209. At 315, the video decoder 209 receives the indication indicating the encoding standard. At 320, a determination is made whether the encoding standard is a first encoding standard, a second encoding standard, or a third encoding standard. If the encoding standard is a first encoding standard at 320, the video decoder 209 selects (325) the portions of the firmware that are unique to the first encoding standard. At 330, the video decoder 209 decodes the encoded video data by executing the portions of the firmware that are unique to the first encoding standard and the portions of the firmware that are common to all of the plurality of encoding standards. If the encoding standard is a second encoding standard at 320, the video decoder 209 selects (335) the portions of the firmware that are unique to the second encoding standard. At 340, the video decoder 209 decodes the encoded video data by executing the portions of the firmware that are unique to the second encoding standard and the portions of the firmware that are common to all of the plurality of encoding standards. If the encoding standard is a third encoding standard at 320, the video decoder 209 selects (355) the portions of the firmware that are unique to the third encoding standard. At 360, the video decoder 209 decodes the encoded video data by executing the portions of the firmware that are unique to the third encoding standard and the portions of the firmware that are common to all of the plurality of encoding standards. Referring now to FIG. 4, there is illustrated a block diagram of an exemplary video decoder 209 in accordance with an embodiment of the present invention. The video decoder 209 comprises a master row engine 405 and a slave row engine 410. The master row engine 405 supports the MPEG-2, MPEG-4, and DV-25 encoding standards. However, in the case of MPEG-2 High Definition Television (HDTV), although the instructions are the same, the rate of data for decoding is high. Accordingly, the slave row engine 410 supplements the master row engine 405 for decoding MPEG-2 video data. The host processor sends an indication to a master processor 430 in the master row engine 410, indicating the type of video data that is to be decoded. Responsive to receiving the signal, the master processor 430 loads the appropriate combination of instructions 295a, 295b, 295c, 295d from the instruction memory into a code data memory 425. [[[or is it the host processor that loads the instructions??]]] If the indicator indicates that the video data is MPEG-2, the master processor 430 also loads the appropriate combination of instructions 295a, 295b, 295c, 295d from the instruction memory into a code data memory 550 in the slave row engine 410. After loading the appropriate combination of instructions 295a, 295b, 295c, 295d, the appropriate combination of instructions cause the master row engine 405 to accesses the video data with a video DMA 420. The video data is received by a bitstream extractor 460. In the case where the video data is MPEG-2, the video data is also received by bitstream extractor 510. The combination of instructions 295a, 295b, 295c, 295d configure and otherwise drive the appropriate hardware in the master row engine 409 and slave row engine 410 for the type of video data received. The master row engine 409 includes hardware components for decoding DV-25, MPEG-2, and MPEG-4 video. The master row engine 409 comprises a Video Engine Interface VEIF, a Quantizer Command Programming (QCP) First-In First-Out queue (FIFO) 490, a Motion Computer (MOTC) 440, a Video Request Manager (VREQM) FIFO 445, an Inverse Quantizer 525, a Video Request Manager 450, an Inverse Discrete Cosine Transformation (IDCT) block 500, and Pixel Reconstructor 455 that are used when decoding DV-25, MPEG-2, and MPEG-4 video data. The master row engine also includes a DV Inverse Quantizer (DVIQ) 480, a DV Variable Length Decoder (DV VLD) 465, and a DV IDCT Preprocessor 505 that are used when decoding DV-25 video data. The slave row engine 410 comprises a master VLD 515, a slave VLD 520, video engine interface (VEIF) 525, a QCP FIFO 530, an inverse quantizer 535, an IDCT 540, a bridge 545, a slave processor 555, an MOTC 560, a VREQM FIFO 565, a video request manager 570, and a pixel reconstructer 575 that are used for decoding MPEG-2 video data. One embodiment of the present invention may be implemented as a board level product, as a single chip, application specific integrated circuit (ASIC), or with varying levels integrated on a single chip with other portions of the system as separate components. The degree of integration of the system will primarily be determined by speed and cost considerations. Because of the sophisticated nature of modern processors, it is possible to utilize a commercially available processor, which may be implemented external to an ASIC implementation of the present system. Alternatively, if the processor is available as an ASIC core or logic block, then the commercially available processor can be implemented as part of an ASIC device with various functions implemented as firmware. While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>A number of different standards exist for encoding video data. In some cases, the video data is also compressed as part of the- encoding process. For example, the Motion Pictures Expert Group (MPEG) has devised two such standards commonly known as MPEG-2, and Advanced Video Coding (MPEG-4). Another example of an encoding standard is known as the Digital Video-25 (DV-25). The encoded video data is decoded by a video decoder. However, a video decoder can receive encoded video data that is encoded with any one of a wide variety of encoding standards. In order to display the video data, the video decoder needs to be able to determine and decode video data that is encoded with any one of the wide variety of encoding standards. Although some video decoders are capable of decoding video data from multiple formats, the video decoders comprise special hardware dedicated to decoding each one of the wide variety of encoding standards.-This is disadvantageous because the additional hardware increases the cost of the decoder system. Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with embodiments presented in the remainder of the present application with references to the drawings. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>Presented herein is a unified decoder architecture. In one embodiment, there is presented a system for decoding video data encoded with a particular standard. The system comprises a video decoder, instruction memory, and a host processor. The video decoder decodes the video data encoded with the particular standard. The instruction memory stores a first set of instructions and a second set of instructions. The first set of instructions are for decoding encoded video data according to a first encoding standard. The second set of instruction are for decoding encoded video data according to a second encoding standard. The host processor provides an indication to the video decoder indicating the particular encoding standard. The video decoder executes the first set of instructions if the indication indicates that the particular encoding standard is the first encoding standard and executes the second set of instructions if the indication indicates that the particular encoding standard is the second encoding standard. In another embodiment, there is presented a method for decoding video data encoded with a particular standard. The method comprises providing an indication to a video decoder indicating the particular encoding standard to the video decoder, executing a first set of instructions if the indication indicates that the particular encoding standard is a first encoding standard, and executing a second set of instructions if the indication indicates that the particular encoding standard is the second encoding standard. In another embodiment, there is presented a system for decoding video data encoded with a particular standard. The system comprises a code memory and a processor. The code memory stores instructions. The processor loads the code memory with a first set of instructions for decoding encoded video data according to a first encoding standard, where the video data is encoded according to the first encoding standard and loads the code memory a second set of instruction for decoding encoded video data according to a second encoding standard, wherein the video data is encoded according to the second encoding standard. These and other advantages and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings. | 20040209 | 20100518 | 20050811 | 97646.0 | 1 | RASHIDIAN, MOHAMMAD M | UNIFIED DECODER ARCHITECTURE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,775,710 | ACCEPTED | Systems and methods that utilize a dynamic digital zooming interface in connection with digital inking | The present invention relates to systems and methods that facilitate annotating digital documents (e.g., digital inking) with devices such as Tablet PCs, PDAs, cell phones, and the like. The systems and methods provide for multi-scale navigation during document annotating via a space-scale framework that fluidly generates and moves a zoom region relative to a document and writing utensil. A user can employ this zoom region to annotate various portions of the document at a size comfortable to the user and suitably scaled to the device display. The space-scale framework enables dynamic navigation, wherein the zoom region location, size, and shape, for example, can automatically adjust as the user annotates. When the user finishes annotating the document, the annotations scale back with the zoom region to original page size. These novel features provide advantages over conventional techniques that do not contemplate multi-scale navigation during document annotating. | 1. A system that facilitates free form digital inking, comprising: an annotation management component that generates a zoomable inking region for a digital document; and a navigation component that dynamically adjusts a size and a shape of the zoomable inking region while a user annotates the digital document. 2. The system of claim 1, wherein the annotation management component is invoked to generate the zoomable inking region by identifying a point of interest on the digital document by at least one of a manual and an automatic technique. 3. The system of claim 1, wherein the zoomable inking region is generated in connection with animation that makes it appear the zoomable inking region grows out of the digital document. 4. The system of claim 1, wherein the zoomable inking region is generated to cover a subset of the digital document such that the remaining document can be concurrently viewed. 5. The system of claim 1, wherein the zoomable inking region magnifies the portion of the digital document within the zoomable inking region. 6. The system of claim 5, wherein the magnification factor is defined such that the user inks at a similar size to document information. 7. The system of claim 1, wherein the zoomable inking region is closed via one of a digital pen, a mouse, a button and voice activation. 8. The system of claim 1, wherein inking within the zoomable inking region scales down to a size similar to the text within the digital document when the zoomable inking region is closed. 9. The system of claim 1, wherein the navigation component employs one or more of a move zoomable inking region, a move digital document and a create space technique to navigate through the digital document. 10. The system of claim 9, wherein the move zoomable inking region, move digital document and create space techniques are based on a space-scale framework. 11. The system of claim 10, wherein the space-scale framework defines navigation via the following equation: ZC=O(1−α)+SCα, wherein ZC is a zoom center, O is a zoom origin, α is a scaling factor, and SC is a screen center. 12. The system of claim 11, wherein the scaling factor is defined by: α=|Z|/|S|, wherein |Z| is an absolute value of a zoom region and |S| is an absolute value of a source window. 13. The system of claim 1, wherein an orientation of the zoomable inking region is determined via moving a digital pen across the document in one of a right-to-left, a left-to-right, a top-to-bottom, and a bottom-to-top manner. 14. A method that provides a zoom window to annotate digital documents with digital ink, comprising: generating the zoom window; scaling contents displayed in the zoom window; positioning the zoom window over an area of interest; and automatically navigating the zoom window while annotating the document. 15. The method of claim 14 further comprising scaling down the document contents and the annotations displayed in the zoom window to a size in line with the text in the document being annotated. 16. The method of claim 14 further comprising defining a shape and a location of the zoom window via indicating a point in the document with at least one of a digital pen, a button, a mouse and voice activation. 17. The method of claim 14 further comprising animating generation of the zoom window to create an appearance that the zoom window grows out of the document. 18. The method of claim 14 further comprising employing a space-scale technique to navigate the zoom window. 19. The method of claim 14 further comprising magnifying the zoom window such that the user can add annotations that are similar in size to the document information displayed within the zoom window. 20. A system that facilitates electronic document annotating, comprising: means for generating an annotation window for an electronic document; means for defining a location of the annotation window means for magnifying contents of the annotation window; means for employing the annotation window to annotate the electronic document; and means for dynamically adjusting the annotation window concurrently with annotating the electronic document. | TECHNICAL FIELD The present invention generally relates to digital document annotating, and more particularly to systems and methods that employ a zoom window that facilitates multi-scale navigation during free form digital inking of a document. BACKGROUND OF THE INVENTION Graphical user interfaces (GUIs) are commonly employed in connection with microprocessor-based computing devices to edit digital documents (e.g., word processing documents, images, etc.). Many of these computing devices (e.g., Tablet PCs, PDAs, cell phones and the like) attempt to provide a natural and expressive way to annotate documents with free form digital ink via a digital pen, mouse, etc. Ideally, utilizing such devices should feel like writing on physical paper, and the resulting annotation should appear similar to its ink counterpart. Thus, a goal of such computing devices is to provide a surface that emulates physical paper. However, a variety of ergonomic factors make it difficult to fully achieve this goal. Examples of such factors include: slip; resolution; screen size; parallax; and device size and weight. Slip generally refers to the fact that pen-computing devices tend to be more slippery than real paper. Resolution takes into account that digital screens have less visual resolution than paper. In addition, digitizers usually track digital pens at lower resolution than the finest human hand movements. Parallax is a consequence of providing a protective layer of plastic over the screen, wherein the protective layer creates an apparent displacement between the tip of the digital pen and underlying document. Size and weight, including screen size, reflects design considerations for portable devices that result in devices and screens that are often smaller than standard letter-size paper and more difficult to position and interact with. While hardware designers continue to improve pen-based devices to make them feel more like paper, a substantial gap remains. Many limitations associated with these devices force users to change the way in which they interact with such devices and annotations often end up appearing very different from ink on paper. In particular, screens associated with such computing devices are usually smaller than a sheet of paper. Conventional techniques for fitting at least a portion of a page within a screen include adjusting the display resolution and/or “zoom.” However, these techniques involve scaling down text and/or graphics, which can render the document information unreadable. In addition, many devices can be hardware and/or software limited such that selecting a higher resolution is not an option. Another problem with scaling down text and/or graphics is that the user typically ends up annotating at a much larger size than they would on paper. The large size of the ink generally results in annotations that are less dense than real ink annotations on paper, consume limited screen real estate, obscure the underlying document, and appear clumsy. Conventional techniques that attempt to address writing scale versus display scale fail to emulate physical paper. For example, in many of these techniques, the user specifies a focus cursor in a main overview area at the top of the screen. Then, the user writes in a focus area at the bottom of the screen, wherein the annotations are reduced to a predefined percentage (e.g., 40%) of the original size and placed at the focus cursor. Upon filling the focus area, the user typically is required to perform a right to left movement in the focus area in order to move the focus cursor forward. With other techniques, the focus area constantly scrolls from right to left, thereby continuously clearing space for new annotations. Still with other techniques, the user is required to explicitly create new writing space when filling the focus area, which can break the flow of writing, or modify their writing style to work with the continuous scrolling writing area. Conventional techniques that employ zooming usually magnify a region of interest within an image or document such that the surrounding context is not visible after the zoom. Navigating in the zoomed view typically requires scrolling, which can be tedious when the magnification factor is high. Other approaches include a multi-scale view of the document, in which a magnified focus region shows details while the surrounding context remains visible. Navigation through the document is typically achieved by positioning a focus region (or lens) over the underlying document, for example, via panning and/or zooming. Although many conventional techniques attempt to provide a natural and expressive way to annotate documents and images with freeform digital ink (via a digital pen, mouse, etc.) these techniques do not overcome the aforementioned problems with annotating on small-screen devices like Tablets PCs, PDAs, cell phones and the like and fail to emulate writing on physical paper. SUMMARY OF THE INVENTION The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later. The present invention provides a focus plus context-based interface that facilitates multi-scale navigation during digital document (e.g., word processing documents, images, etc.) annotating by microprocessor-based devices (e.g., desktop computers, Tablet PCs, PDAs and cell phones) with tools such as a digital pen, a mouse, etc. The systems and methods of the present invention provide an interface that zooms a region of an underlying document, wherein a user can enter annotations in the region at a size comfortable to the user and suitably scaled to the device display. This region can automatically adjust (e.g., location, size, shape, etc.), as needed, while the user annotates. When the zoom region is reduced back to the normal page size, the digital ink annotations scale to an appropriate size, based on the underlying document. The systems and methods of the present invention build upon free-form digital ink and zoomable user interfaces to provide a mobile zoom region that can be variously configured to automatically grow and/or move and only cover a subset of the screen so that a user can see the overall context of the underlying document, if desired. This novel feature provides advantages over conventional techniques that do not contemplate multi-scale navigation during document annotating. The subject invention employs various techniques based on a scale-space framework in order to fluidly place and move the zoom region with respect to the underlying document and the user's writing tool. These techniques enable quick and easy digital document annotation, wherein the resulting annotations closely mimic the look and feel of annotations on physical paper. In one aspect of the present invention, a system that facilitates document annotation within microprocessor-based devices is illustrated. The system comprises an annotation management component that generates annotation regions and an annotation configuration component that provides annotation region properties that are employed to generate the annotation regions. The annotation management component can be invoked to generate an annotation region from a user interface via an action, a sound, and/or automatically. The annotation management component can obtain annotation region configurations from an annotation configuration component and/or from the user or intelligence components. Such configuration information can define annotation region size, shape, location, appearance, etc., as well as navigation characteristics. The annotation region can be generated to occupy at least a subset of the viewing area and be positioned proximate an area of interest such that the user is provided with ample space to view document information and add annotations within the annotation region, as well as continue to view remaining portions of non-scaled document information. In addition, the annotation region typically scales the document information residing therein so that the user can comfortably add annotations that are relatively similar in size to the document information. The system further comprises a navigation component that provides navigation algorithms. As needed, the annotation region can be re-positioned and/or re-shaped via the algorithms to enable the user to add annotations essentially anywhere on the document. When the annotation region is closed, the document information can be scaled back to its original size and the annotations can be scaled by a similar factor or a different factor, depending on the properties provided by the annotation configuration. In another aspect of the present invention, a methodology that facilitates annotating a digital document is illustrated. The methodology comprises activating a zoomable user interface, or zoom window, for example, with a digital pen via tapping at a point on a display. The zoom window can be generated proximate this point and can provide a magnified view of the document lying below the zoom window. Animation can be employed to generate this zoom window. After the zoom window is generated, a user can annotate the underlying document via the zoom window, for example, by writing within the zoom window. The zoom window can be utilized to annotate various regions of the document by moving the zoom window to desired locations prior to and during annotating the document. The user can close the zoom window, wherein document content as well as the annotations can scale to a size consonant with the underlying document. In yet other aspects of the present invention, document annotation methodologies based on a space-scale framework are illustrated. The methodologies are utilized to position and navigate a zoom window while annotating a document. In one instance, the zoom window automatically adjusts, as needed, to provide the user with seamless and unobstructed annotation capabilities. In another instance, the document is moved relative to the zoom window. In yet another instance, the zoom window is moved relative to the underlying document. Other aspects of the present invention illustrate annotation systems that employ intelligence to facilitate generation and management of a zoom window, examples of documents annotated with the novel aspects of the present invention, and various shapes that can be employed in accordance with aspects of the present invention. Moreover, environments are illustrated wherein the novel aspects of the present invention can be employed. To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects and implementations of the invention. These are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an exemplary system that facilitates electronic document annotation. FIG. 2 illustrates an exemplary annotation component that can be employed in connection with various microprocessor-based devices. FIG. 3 illustrates an exemplary methodology that employs an interactive zoomable user interface to facilitate document annotation. FIG. 4 illustrates an exemplary methodology that facilitates document annotating via a zoom window. FIG. 5 illustrates an exemplary two-dimensional schematic associated with a space-scale framework. FIG. 6 illustrates an exemplary one-dimensional diagram associated with a space-scale framework. FIG. 7 illustrates an exemplary two-dimensional schematic associated with a space-scale framework. FIG. 8 illustrates an exemplary one-dimensional diagram associated with a space-scale framework. FIG. 9 illustrates a first exemplary annotation methodology. FIG. 10 illustrates a second exemplary annotation methodology. FIG. 11 illustrates a third exemplary annotation methodology. FIG. 12 illustrates an exemplary intelligence based system that facilitates document annotating. FIG. 13 illustrates various ergonomic limitations of pen computing devices. FIG. 14 illustrates an exemplary system that overcomes ergonomic limitations of pen computing devices. FIGS. 15-17 illustrate utilization of a novel multi-scale navigation zoom window in connection with a user interface. FIGS. 18-21 illustrate various zoom window orientations. FIG. 22 illustrates various zoom window shapes. FIG. 23 illustrates an exemplary networking environment, wherein the novel aspects of the present invention can be employed. FIG. 24 illustrates an exemplary operating environment, wherein the novel aspects of the present invention can be employed. DETAILED DESCRIPTION OF THE INVENTION The present invention provides systems and methods that facilitate annotating digital documents (e.g., word processing documents, images, etc.) displayed by microprocessor-based devices such as desktop computers, Tablet PCs, PDAs, cell phones, and the like. The systems and methods provide a focus plus context-based interface that enables multi-scale navigation during document annotation. This interface zooms a region of an underlying document, wherein a user can enter annotations in the region at a size comfortable to the user and suitably scaled to the device display. In addition, the zoom interface is fluidly placed and adjusted with respect to the underlying document and the user's writing tool via various scale-space framework-based techniques, wherein the zoom region can automatically adjust in location, size, and shape, for example, while the user annotates in order to provide an experience that resembles annotating physical paper. When the zoom region scales back to page size, annotations scale to an appropriate size based on the underlying document. These novel features provide advantages over conventional techniques that do not contemplate multi-scale navigation during document annotating. The present invention is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It may be evident, however, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the present invention. As used in this application, the terms “component” and “device” are intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a computer component. In addition, one or more components can reside within a process and/or thread of execution, and a component can be localized on one computer and/or distributed between two or more computers. Furthermore, a component can be an entity (e.g., within a process) that an operating system kernel schedules for execution. Moreover, a component can be associated with a context (e.g., the contents within system registers), which can be volatile and/or non-volatile data associated with the execution of the thread. As used in this application, the terms “inking,” “digital inking,” “annotating” “digital annotating,” and variants thereof can refer to virtually any technique that can be utilized to display and/or perform an action in connection with a document including viewing, navigating, editing, adding comments, adding notes, changing format, and/or correcting punctuation and grammar, for example. FIG. 1 illustrates a system 100 that facilitates digital inking. The system 100 comprises an annotation management component 110 that generates inking, or annotation regions and an input component 120 that conveys requests for inking regions to the annotation management component 110. In general, the system 100 can be employed with virtually any microprocessor-based device and in connection with essentially any user interface (e.g., text and graphics) executing therein. For example, the system 100 can be utilized with word processors to modify word processing and/or image documents. When employed with a user interface, the annotation management component 110 can generate at least one inking region (e.g., editable text/graphics) for the user interface. The annotation management component 110 can be invoked by the input component 120 when the input component 120 receives a request to generate an inking region via an action, a sound, a button press, a mouse click, and/or automatically, as described in detail below. Once generated, a user can employ the inking region to add an annotation to a document. For example, the user can employ an input device such as a digital pen, keyboard, touch-screen, voice, mouse, etc. to add free form text and/or graphics to the inking region. Once an annotation is entered in the inking region, it can be edited, removed and/or accepted. In addition, a previously generated inking region can be re-activated, wherein additional annotations can be added and/or existing annotations can be edited and/or removed. It is to be appreciated that the inking region can be suitably scaled so that the user can add annotations that are relatively similar in size to the document information. For example, where the user is adding free form annotations (e.g., via a digital pen) to a text document, the inking region can zoom existing document information that is presented within the inking region so that the user can comfortably add annotations that are approximately similar in size, if desired. Thus, when a document is displayed such that a user is unable to add annotations or it is difficult to add annotations similar in size to the existing document information, the present invention provides a novel scaling technique that enables the user to add annotations similar in size to the existing document information, if desired. Additionally, the user can add annotations smaller or larger in size than the existing document information, if desired. Moreover, the inking region can be manually and/or automatically re-positioned and/or re-sized relative to the document to enable the user to add annotations essentially anywhere on the document. Such changes to the inking region can occur prior to, concurrently with and/or after annotating. Thus, the present invention provides a novel technique for multi-scale navigation before, during and after annotating. As described in detail below, various navigation techniques that are based on a space-scale framework can be employed in accordance with aspects of the present invention. The foregoing provides an improvement over conventional systems, which do not employ multi-scale navigation during annotating. FIG. 2 illustrates a system 200 for generating a digital inking region. The system 200 comprises an annotation management component 210 that generates inking regions, a configuration component 220 that provides inking region properties, and a navigation component 230 that provides inking region navigation algorithms. The annotation management component 210 (e.g., annotation management component 110) can generate at least one inking region for the user interface. Typically, generation and/or deactivation of the inking region is in response to a user request through mechanisms such as an action, a sound, a button press, and/or a mouse click. However, automatic techniques can be employed. Once generated, the inking region can be employed to add one or more annotations to a document. In general, the inking region can be generated such that the user can add annotations that are relatively similar in size to the document information presented within the inking region; however, it is to be appreciated that the user can adjust annotation scaling as a desired. In addition, the inking region can be manually and/or automatically re-positioned and/or re-sized relative to the document to enable the user to add annotations essentially anywhere on the document. When closing an inking region, annotations and document information therein are scaled to document size. Upon generation, the annotation management component 210 can obtain inking region properties from the configuration component 220. Such properties can include information related to inking region size, shape, location, appearance, etc. In addition, information related to post-generation activities such as activation/deactivation, editing, size, shape, location, appearance and termination can be obtained from the configuration component 220. It is to be appreciated that such information can be provided to the configuration component 220 by a user and/or automatically generated with intelligence. In addition, the inking region can be generated to occupy a subset of, or an entire viewing area, depending, for example, on the inking region properties provided by the configuration component 220. Thus, the inking region can be generated and positioned proximate an area of interest such that the user is provided with ample space to view scaled document information and add annotations within the inking region, as well as continue to view remaining portions of non-scaled document information, or portions of the document outside of the inking region. The navigation component 230 provides algorithms that enable manual and/or automatic re-positioning and/or re-sizing relative to the document in order to allow the user to add annotations essentially anywhere on the document. Such re-positioning and/or re-sizing can occur prior to, concurrently with or after annotating; thus, the present invention provides for multi-scale navigation before, during and after annotating. The algorithms are based on a space-scale framework and include a create space, a move inking region, and a move document algorithm. The space-scale framework is based on geometric relationships between the inking region and the document being annotated. The create space algorithm automatically re-sizes and re-positions the inking region as the user annotates the document. Typically, the inking region automatically changes shape to create space as the user annotates near the edge of the inking region. This can be achieved by extending the inking region while fixing a mapping between a source plane and a zoom plane and by moving the inking region center to a new center, wherein the inking region remains under the pen, but provides more space to continue annotating. This approach provides for a smooth transition that does not disrupt the user's annotating experience. The move inking region algorithm moves the inking region relative to the underlying document during annotation. In general, when the inking region is generated, an inking region center is locked. When the inking region is dragged to a new location, the inking region center and a source center concurrently move and a new zoom origin is generated. The foregoing ensures that a user can zoom any point in the underlying document as the inking region is moved from location to location. The move underlying document algorithm moves the document being annotated relative to the inking region. With this approach, portions of the document that are displayed within the inking region are determined by moving the document rather than the inking region. In general, the inking region center is locked such that the inking region remains fixed with respect to the surrounding document context. When a user can move a source center to a new location, a new inking region origin is generated. This approach ensures that the user can zoom any point in the underlying document by dragging the source window instead of the inking region. FIGS. 3-4 illustrate document annotation methodologies 300 and 400 in accordance with the present invention. For simplicity of explanation, the methodologies are depicted and described as a series of acts. It is to be understood and appreciated that the present invention is not limited by the acts illustrated and/or by the order of acts, for example acts can occur in various orders and/or concurrently, and with other acts not presented and described herein. Furthermore, not all illustrated acts may be required to implement the methodologies in accordance with the present invention. In addition, those skilled in the art will understand and appreciate that the methodologies could alternatively be represented as a series of interrelated states via a state diagram or events. Referring initially to FIG. 3, a methodology 300 that facilitates annotating a document with microprocessor-based devices is illustrated in accordance with an aspect of the present invention. At reference numeral 310, an inking region, or zoom window is activated (e.g., by the system 100). In one aspect of the present invention, the inking region can be activated via a digital pen. For example, a user employing a digital pen can indicate a zoom origin within a viewable area of a display by tapping at a point on the display. The inking region can be generated proximate this zoom origin, as described in detail below, and provides a magnified view of the document lying below the zoom window that defines an editable region wherein the user can add text and/or graphics (e.g., comments) over the underlying document. It is to be appreciated that in other aspects of the present invention, activation can be achieved via other means such as voice, mouse, and/or automation. It is noted that animation can be employed to generate the inking region. For example, animation can be utilized that makes it appear that the inking region grows out of the page. Other suitable animation techniques include box (in and out), blind (horizontal and vertical), checkerboard (across and down), cover (left, right, up, down and diagonal), cut, dissolve, fade, split (horizontal and vertical), wipe (left, right, up and down), uncover, and the like, and/or any combination thereof. In addition, it is noted that a default inking region orientation, shape, size, location, etc. can be pre-defined or automatically generated. Moreover, inking region characteristics can be manually and/or automatically changed at any time. After the inking region is generated, at 320 the user can annotate the underlying document via the inking region. In one aspect of the present invention, the user can annotate the document via writing within the inking region. For example, the user can utilize a digital pen or a mouse. In other aspects of the present invention, voice and/or a keyboard can be employed to write within the inking region. It can be appreciated that the zoom factor for the inking region can be selected to approximately match the user's natural writing size. Such selection can entail utilizing an iterative approach wherein the factor is refined until it approximately matches the user's natural writing size and/or via an intelligence-based approach wherein the user's writing is stored, analyzed and utilized to automatically refine the factor. The inking region can be utilized to annotate similar and/or disparate regions of the document by moving the inking region to desired locations. Various algorithms, as described in detail below, can be utilized to move the inking region. These algorithms include: activating other inking regions at various locations of the document; closing the inking region and activating another inking region at a different location; moving (e.g., dragging and cut-and-paste) the inking region, moving the document while the inking region remains fixed; and automatically moving the inking region and adjusting its size during annotating. At reference numeral 330, the user can accept annotations and close the inking region. In one aspect of the invention, acceptance can be indicated similarly to activating the inking region. For example, the user can tap on an inking region or the document, provide a voice command and/or automatically close it. It is noted that the above animation techniques can be utilized during accepting the annotation. When an inking region is closed, the document contents as well as the annotations can scale to a size consonant with the underlying document. Thus, it appears that the user annotated the document at a size correlated to underlying document content. In other aspects of the invention, annotation scaling can differ in order to refine annotation size with respect to the document information. FIG. 4 illustrates an exemplary methodology 400 that facilitates electronic document annotating via a zoom window, in accordance with an aspect of the present invention. At reference numeral 410, default configurations for zoom window, or inking region generation can be defined for one or more users. As described in connection with the system 200, such configurations relate to properties that determine zoom window size, shape, location, appearance, activation/deactivation, editing and/or termination. Where a single default configuration is utilized, the configuration can be retrieved whenever a request for a zoom window is received. Where a plurality of default configurations are generated, a configuration associated with a particular user can be obtained from the plurality of configurations based on user information such as logon, password, application, machine address, etc. This retrieved configuration can provide zoom window properties and characteristics such as size, orientation, direction and position, for example. For example, the configuration can be utilized to generate a zoom window in accordance with the manner in which the English language is normally written, or the zoom window can be generated as a horizontal box suitable for accepting annotations in a left to right manner. In addition, the configuration can be utilized to offset the zoom window from the zoom origin in order to facilitate left to right annotating. For example, the configuration can be set such that 70% of the zoom window resides to the right of the zoom origin. It is to be appreciated that other configurations may be implemented, for example, a vertical orientation to annotate side margins or a horizontal window generated such that the majority of the zoom window resides to the left of the zoom origin to facilitate right-to-left annotating. At 420, a user can initiate creation of the zoom window as described herein, and based on an associated configuration. It is to be appreciated that in various aspects of the present invention, default configurations can be fully or partially overridden. For example, methodology 400 provides for an alternative mechanism to define the desired zoom window orientation. In one instance, the user can employ a digital pen in a particular direction or shape that is indicative of an orientation. For example, after indicating that a zoom window should be generated, the user can move the pen in a left to right direction to indicate that the zoom window should be generated with a left to right orientation. Similarly, the user can move the pen in a top to bottom direction to indicate that the zoom window should be generated with a top to bottom orientation. It is to be appreciated that virtually all of the default configurations can be overridden. It is further noted that zoom window creation can still be activated by tapping the pen, a voice command or other means, but that subsequent pen activity can provide the information that determines zoom window properties and characteristics. At reference numeral 430, the user can annotate the underlying document via the zoom window as described herein. It is noted that the above technique can be utilized to move the zoom window during annotation, move the zoom window in accordance with the zoom window orientation. Thus, a zoom window generated for right-to-left annotating moves and/or grows in a right to left direction. In addition, this orientation can be changed while annotating; thus, any movement and/or growth can likewise be changed. For example, the user can activate a zoom window in a top to bottom orientation in order to annotate a margin. Then, the user can change the zoom window orientation to a left to right orientation in order to annotate the document contents. At 440, the zoom window can be closed. As noted above, the document contents displayed in the zoom window as well as any annotations can scale down to a size that corresponds to the document text and/or graphics. Thus, the user can annotate at a comfortable size in an environment that mimics physical paper and pen. FIGS. 5-8 illustrate an exemplary space-scale framework that can be utilized to facilitate zoom window (inking region) placement and navigation in accordance with an aspect of the present invention. This space-scale technique is based on geometric relationships between a zoom region and the document being annotated, wherein zooming is represented as a projection from a zoom origin 0, through a source window S, and onto a zoom window Z, and a scaling factor α is given by Equation 1. α=|Z|/|S|, Equation 1 wherein |Z| and |S| denote the absolute value of the width of the zoom window and source window, respectively. Furthermore, by similar triangles, the center of the zoom window ZC, the center of the source window SC, and the zoom origin O are related by Equation 2. ZC=O(1−α)+SCα. Equation 2 In general, this expression holds for any set of points ZC and SC lying on a projector line emanating from an origin O. The space of geometric interactions with the system can be expressed in terms of these parameters, wherein, for a given scale factor α, two of these parameters can be varied (two degrees of freedom) while the third is constrained. Referring initially to FIG. 5, a schematic of a zooming interface 500 is illustrated, in accordance with an aspect of the present invention. The zooming interface 500 comprises a screen 510 with a zoom window (Z) 520 and a source window (S) 520. As depicted, the zoom window (Z) 520 and source window (S) 530 are oriented such that a zoom origin (O) 540, a zoom center (ZC) 550 and a source (SC) 560 are located about the same point within the screen 510. It is noted that the screen 510 is illustrated as a top down view looking into an X-Y plane. However, it is to be appreciated that the screen can lie in any two planes. FIG. 6 depicts a diagram 600 of the zooming interface 500 from a X-Z plane, relative to the X-Y plane. Illustrated are the zoom origin (O) 540, the zoom center (ZC) 550 and the source (SC) 560 located respectively within an origin plane 610, a source plane 620 and a zoom plane 630. This space-scale diagram shows a mapping between the zoom origin (O) 540, the source window (S) 530, and the zoom window (Z) 520 can be a projection, wherein the planes are spaced such that the projection scales any region on the source plane 620 by the zoom factor α with respect to the zoom origin (O) 540. FIG. 7 illustrates a schematic 700 from the X-Y plane of the zooming interface 500, wherein the zoom window (Z) 520 and the source window (S) 530 have been re-centered around a zoom origin (O) 710 and a source (SC) 720, respectively. FIG. 8 illustrates a corresponding diagram 800 of the zooming interface 500 from the X-Z plane. FIGS. 9-11 illustrate annotation window location and navigation methodologies 900, 1000 and 1100, respectively, in accordance with the present invention. In general, methodologies 900 and 1000 can be referred to as explicit approaches and methodology 1100 can be referred to as an implicit approach. For simplicity of explanation, the methodologies are depicted and described as a series of acts. It is to be understood and appreciated that the present invention is not limited by the acts illustrated and/or by the order of acts, for example acts can occur in various orders and/or concurrently, and with other acts not presented and described herein. Furthermore, not all illustrated acts may be required to implement the methodologies in accordance with the present invention. In addition, those skilled in the art will understand and appreciate that the methodologies could alternatively be represented as a series of interrelated states via a state diagram or events. Turning to FIG. 9, an exemplary navigation methodology 900 (and corresponding space-scale diagram) that moves a zoom window relative to a document during annotation is illustrated in accordance with an aspect of the present invention. At reference numeral 910, a zoom window is generated as described herein. Once generated, a zoom center (Z) 925 can be locked to a source center (S) 930. At 920, the zoom window can be dragged to a new location. When the user moves zoom center (Z) 925 to a zoom center (Z′) 935, the source center (S) 930 concurrently moves to a source center (S′) 940 (due to locking zoom center (Z) with source center (S)) and a zoom origin (O) 945 concurrently moves to a zoom origin (O′) 950 based on Equation 2 (Z=O(1−α)+Sα). It is noted that the initial positions can be referred to as absolute positions of the zoom window with respect to the underlying document and the new positions can be referred to as relative positions with respect to the original absolute positions. Thus, as the user drags the zoom window, the zoom center, source center and source origin are concurrently translated, which ensures that a user can zoom any point in the underlying document as the zoom window is dragged from location to location. At reference numeral 960, the user can employ the zoom window to annotate the new location. FIG. 10 illustrates an exemplary navigation methodology 1000 (and corresponding space-scale diagram) that moves a document being annotated relative a zoom window, in accordance with an aspect of the present invention. This approach changes the portion of the document that is within the zoom window rather than moving the zoom window. At reference numeral 1010, a zoom window is generated as described herein. Once generated, a zoom center (Z) 1015 can be locked such that a zoom center (Z′) 1020 equals the zoom center (Z) 1015. By locking the zoom center (Z) 1015, the zoom window remains fixed with respect to surrounding context. At 1030, a user can drag a source center (S) 1035 to a new source center (S′) 1040 (e.g., via a relative pen motion). A zoom origin (O) 1045 moves to a zoom origin (O′) 1050 based on Equation 2 (Z=O(1−α)+Sα). This approach ensures that the user can zoom any point in the underlying document by dragging the source window instead of the zoom window. At reference numeral 1060, the user can employ the zoom window to annotate the new location. FIG. 11 illustrates an exemplary navigation methodology 1100 (and corresponding space-scale diagram) that automatically re-sizes and positions a zoom window as a user annotates a document, in accordance with an aspect of the present invention. At reference numeral 1110, a zoom window is generated as described herein. At reference numeral 1120, the user can employ the zoom window to annotate the document. At 1130, the zoom window automatically changes shape to create space as the user annotates near the edge of the zoom window. In one aspect of the invention, this can be achieved by extending the zoom window via moving a zoom center (Z) 1135 to a zoom center (Z′) 1140 such that the zoom window remains under the pen and provides more space to continue writing and fixing the mapping between the source plane and zoom plane. This mapping can be fixed by keeping a zoom origin (O) 1145 fixed while allowing a source center (S) 1150 to move. Thus, a zoom origin (O′) 1155 is set equal to the zoom origin (O) 1145, given the zoom center (Z′) 1140, a source center (S′) 1160 can be determined via Equation 2 (Z=O(1−α)+Sα). With a fixed mapping, users can be provided with access to the entire document or limited to a subset thereof, as depicted by at 1165 and at 1170. This approach provides for a smooth transition that does not disrupt the user's annotating experience. FIG. 12 illustrates an exemplary intelligence based system 1200 that facilitates digital document annotating, in accordance with an aspect of the present invention. The system 1200 comprises a pen-based microprocessor device (device) 1210. The device 1210 includes a graphical user interface (GUI) that can be utilized to view and/or edit documents. As such, the GUI can comprise mechanisms (e.g., input and output) that facilitate communication and/or interaction. For example, the interface can comprise text and/or graphic presenting (e.g., output) regions comprising dialogue boxes, static controls, drop-down-menus, list boxes, pop-up menus, and graphic boxes. The presenting regions can further include utilities to facilitate display. For example, the presenting regions can include vertical and/or horizontal scroll bars to facilitate navigation and toolbar buttons to determine whether a region will be viewable, and to adjust zoom, orientation and/or color/gray scale. A user can interact with the presenting regions to view, select and provide information via various devices such as a mouse, a roller ball, a keypad, a keyboard, a pen and/or voice activation, for example. Input regions utilized to accept information can employ similar mechanisms (e.g., dialogue boxes, etc.) and, in addition, utilities such as edit controls, combo boxes, radio buttons, check boxes and push buttons, wherein the user can employ various input devices (e.g., the mouse, the roller ball, the keypad, the keyboard, the pen and/or voice activation) in connection with the mechanism and utilities. For example, the user can provide a parameter or variable, or pointer thereto (e.g., a register location) via entering the information into an edit control box and/or highlighting an associated check box. Typically, a mechanism such as a push button is employed subsequent to entering the information in order to initiate conveyance of the information. However, it is to be appreciated that the invention is not so limited. For example, merely highlighting the check box can initiate information conveyance. The above-noted interface can be utilized by a user to launch a zoom window via activating an annotation component 1220. Such activation can be through a request directly to the annotation component 1220 and/or indirectly to the annotation component 1220 via an intelligence component 1230. The annotation component 1220 can then generate a zoom window for the device 1210 as described above. In addition, an intelligence component 1230 can facilitate zoom window generation. For example, the intelligence component 1230 can provide the annotation component 1210 with zoom window generation information. This information can be based on a user, a document being annotated and/or an application utilized to view the document. The intelligence component 1230 can further facilitate managing the zoom window during annotating. For example, the intelligence component 1230 can provide information related to the zoom window shape, size, appearance, location, etc. Similar to generation information, this information can also be based on the user, the document being annotated and/or the application utilized to view the document. It is to be appreciated that the intelligence component 1230 can make decisions based on statistics, inferences, probabilities and classifiers (e.g., explicitly and implicitly trained), including but not limited to, Bayesian learning, Bayesian classifiers and other statistical classifiers, such as decision tree learning methods, support vector machines, linear and non-linear regression and/or neural networks. FIG. 13 illustrates various ergonomic limitations of conventional pen computing devices. Reference numeral 1310 illustrates a user interface employed to view and annotate a document. The document within the user interface includes text, graphics and various formatting and hand written annotations. Region 1320 shows a magnified portion of the document. As depicted, the annotations within the region 1320 are substantially larger than the type written text in the document, which commonly occurs when annotating with a pen-computing device since the monitor size is typically smaller than a standard sheet of paper. As a result, these annotations created by conventional systems can obscure an underlying document and generally appear clumsy. FIG. 14 illustrates a user interface 1410 employing the novel aspects of the present invention to annotate a document. Similar to the user interface 1310, the document within the user interface 1410 includes text, graphics and various formatting and hand written annotations and region 1420 shows a magnified portion of the document. As depicted, the user added annotations within the region 1420 are similar in size to the text within the document, and, thus, the annotations appear as similar to physical pen annotations on a physical document. FIGS. 15-21 illustrate a user interface employed in connection with the novel aspects of the present invention to annotate a document. Referring initially to FIG. 15, a user generates a zoom window by indicating a zoom origin 1510 within the user interface 1520. As depicted, the user taps at the zoom origin 1510 within the user interface 1520 with the digital pen 1530. Turning to FIG. 16, a zoom window 1610 is generated around the zoom origin 1520. As noted previously, the zoom window 1610 can be variously shaped and positioned, depending on the properties (a default or user defined configuration) utilized during generation. As depicted, zoom window 1610 is generated as a horizontally rectangular-shaped region positioned such that the majority of region is to the right of the zoom origin 1520. In addition, the document information displayed within the zoom window 1610 is scaled up to allow the user to comfortably add annotations similar in size to the documents information. FIG. 16 additionally shows pen annotations 1620 within the zoom window 1610. FIG. 17 shows the user interface 1520 after the user closes the zoom window 1610. As noted above, the zoom window 1610 can be closed via tapping the digital pen within the zoom window 1610. FIG. 17 additionally shows that the pen annotations 1620 scale down with the contexts of the zoom window to a size proportional with the document contents. FIGS. 18-21 illustrate other exemplary zoom windows. FIGS. 18 and 19 depict horizontal zoom windows 1800 and 1900, respectively, that are utilized to annotate text and images, respectively. FIGS. 20 and 21 depict vertical oriented zoom windows 2000 and 2100, respectively. FIG. 22 illustrates various zoom window shapes that can be employed in aspects of the present invention. At 2210, a vertical rectangular zoom window is illustrated. This shape can be generated to facilitate margin annotations and top to bottom writing. At 2220, a square-shaped zoom window is illustrated. At 2230, an octagonal-shaped zoom window is depicted. Reference numerals 2240 and 2250 illustrate circular and elliptical zoom windows, respectively. Reference numeral 2260 depicts an irregular-shaped zoom window. In order to provide a context for the various aspects of the invention, FIGS. 23 and 24 as well as the following discussion are intended to provide a brief, general description of a suitable computing environment in which the various aspects of the present invention can be implemented. While the invention has been described above in the general context of computer-executable instructions of a computer program that runs on a computer and/or computers, those skilled in the art will recognize that the invention also can be implemented in combination with other program modules. Generally, program modules include routines, programs, components, data structures, etc. that perform particular tasks and/or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the inventive methods may be practiced with other computer system configurations, including single-processor or multiprocessor computer systems, mini-computing devices, mainframe computers, as well as personal computers, hand-held computing devices, microprocessor-based or programmable consumer electronics, and the like. The illustrated aspects of the invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. However, some, if not all aspects of the invention can be practiced on stand-alone computers. In a distributed computing environment, program modules may be located in both local and remote memory storage devices. FIG. 23 is a schematic block diagram of a sample-computing environment 2300 with which the present invention can interact. The system 2300 includes one or more client(s) 2310. The client(s) 2310 can be hardware and/or software (e.g., threads, processes, computing devices). The system 2300 also includes one or more server(s) 2320. The server(s) 2320 can also be hardware and/or software (e.g., threads, processes, computing devices). The servers 2320 can house threads to perform transformations by employing the present invention, for example. One possible communication between a client 2310 and a server 2320 can be in the form of a data packet adapted to be transmitted between two or more computer processes. The system 2300 includes a communication framework 2340 that can be employed to facilitate communications between the client(s) 2310 and the server(s) 2320. The client(s) 2310 are operably connected to one or more client data store(s) 2350 that can be employed to store information local to the client(s) 2310. Similarly, the server(s) 2320 are operably connected to one or more server data store(s) 2330 that can be employed to store information local to the servers 2340. With reference to FIG. 24, an exemplary environment 2410 for implementing various aspects of the invention includes a computer 2412. The computer 2412 includes a processing unit 2414, a system memory 2416, and a system bus 2418. The system bus 2418 couples system components including, but not limited to, the system memory 2416 to the processing unit 2414. The processing unit 2414 can be any of various available processors. Dual microprocessors and other multiprocessor architectures also can be employed as the processing unit 2414. The system bus 2418 can be any of several types of bus structure(s) including the memory bus or memory controller, a peripheral bus or external bus, and/or a local bus using any variety of available bus architectures including, but not limited to, Industrial Standard Architecture (ISA), Micro-Channel Architecture (MSA), Extended ISA (EISA), Intelligent Drive Electronics (IDE), VESA Local Bus (VLB), Peripheral Component Interconnect (PCI), Universal Serial Bus (USB), Advanced Graphics Port (AGP), Personal Computer Memory Card International Association bus (PCMCIA), and Small Computer Systems Interface (SCSI). The system memory 2416 includes volatile memory 2420 and nonvolatile memory 2422. The basic input/output system (BIOS), containing the basic routines to transfer information between elements within the computer 2412, such as during start-up, is stored in nonvolatile memory 2422. By way of illustration, and not limitation, nonvolatile memory 2422 can include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable ROM (EEPROM), or flash memory. Volatile memory 2420 includes random access memory (RAM), which acts as external cache memory. By way of illustration and not limitation, RAM is available in many forms such as synchronous RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM). Computer 2412 also includes removable/non-removable, volatile/non-volatile computer storage media. FIG. 24 illustrates, for example a disk storage 2424. Disk storage 2424 includes, but is not limited to, devices like a magnetic disk drive, floppy disk drive, tape drive, Jaz drive, Zip drive, LS-100 drive, flash memory card, or memory stick. In addition, disk storage 2424 can include storage media separately or in combination with other storage media including, but not limited to, an optical disk drive such as a compact disk ROM device (CD-ROM), CD recordable drive (CD-R Drive), CD rewritable drive (CD-RW Drive) or a digital versatile disk ROM drive (DVD-ROM). To facilitate connection of the disk storage devices 2424 to the system bus 2418, a removable or non-removable interface is typically used such as interface 2426. It is to be appreciated that FIG. 24 describes software that acts as an intermediary between users and the basic computer resources described in suitable operating environment 2410. Such software includes an operating system 2428. Operating system 2428, which can be stored on disk storage 2424, acts to control and allocate resources of the computer system 2412. System applications 2430 take advantage of the management of resources by operating system 2428 through program modules 2432 and program data 2434 stored either in system memory 2416 or on disk storage 2424. It is to be appreciated that the present invention can be implemented with various operating systems or combinations of operating systems. A user enters commands or information into the computer 2412 through input device(s) 2436. Input devices 2436 include, but are not limited to, a pointing device such as a mouse, trackball, stylus, touch pad, keyboard, microphone, joystick, game pad, satellite dish, scanner, TV tuner card, digital camera, digital video camera, web camera, and the like. These and other input devices connect to the processing unit 2414 through the system bus 2418 via interface port(s) 2438. Interface port(s) 2438 include, for example, a serial port, a parallel port, a game port, and a universal serial bus (USB). Output device(s) 2440 use some of the same type of ports as input device(s) 2436. Thus, for example, a USB port may be used to provide input to computer 2412, and to output information from computer 2412 to an output device 2440. Output adapter 2442 is provided to illustrate that there are some output devices 2440 like monitors, speakers, and printers, among other output devices 2440, which require special adapters. The output adapters 2442 include, by way of illustration and not limitation, video and sound cards that provide a means of connection between the output device 2440 and the system bus 2418. It should be noted that other devices and/or systems of devices provide both input and output capabilities such as remote computer(s) 2444. Computer 2412 can operate in a networked environment using logical connections to one or more remote computers, such as remote computer(s) 2444. The remote computer(s) 2444 can be a personal computer, a server, a router, a network PC, a workstation, a microprocessor based appliance, a peer device or other common network node and the like, and typically includes many or all of the elements described relative to computer 2412. For purposes of brevity, only a memory storage device 2446 is illustrated with remote computer(s) 2444. Remote computer(s) 2444 is logically connected to computer 2412 through a network interface 2448 and then physically connected via communication connection 2450. Network interface 2448 encompasses communication networks such as local-area networks (LAN) and wide-area networks (WAN). LAN technologies include Fiber Distributed Data Interface (FDDI), Copper Distributed Data Interface (CDDI), Ethernet, Token Ring and the like. WAN technologies include, but are not limited to, point-to-point links, circuit switching networks like Integrated Services Digital Networks (ISDN) and variations thereon, packet switching networks, and Digital Subscriber Lines (DSL). Communication connection(s) 2450 refers to the hardware/software employed to connect the network interface 2448 to the bus 2418. While communication connection 2450 is shown inside computer 2412, it can also be external to computer 2412. The hardware/software necessary for connection to the network interface 2448 includes, for exemplary purposes only, internal and external technologies such as, modems including regular telephone grade modems, cable modems and DSL modems, ISDN adapters, and Ethernet cards. What has been described above includes examples of the present invention. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present invention, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present invention are possible. Accordingly, the present invention is intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims. In particular and in regard to the various functions performed by the above described components, devices, circuits, systems and the like, the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., a functional equivalent), even though not structurally equivalent to the disclosed structure, which performs the function in the herein illustrated exemplary aspects of the invention. In this regard, it will also be recognized that the invention includes a system as well as a computer-readable medium having computer-executable instructions for performing the acts and/or events of the various methods of the invention. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms “includes,” and “including” and variants thereof are used in either the detailed description or the claims, these terms are intended to be inclusive in a manner similar to the term “comprising.” | <SOH> BACKGROUND OF THE INVENTION <EOH>Graphical user interfaces (GUIs) are commonly employed in connection with microprocessor-based computing devices to edit digital documents (e.g., word processing documents, images, etc.). Many of these computing devices (e.g., Tablet PCs, PDAs, cell phones and the like) attempt to provide a natural and expressive way to annotate documents with free form digital ink via a digital pen, mouse, etc. Ideally, utilizing such devices should feel like writing on physical paper, and the resulting annotation should appear similar to its ink counterpart. Thus, a goal of such computing devices is to provide a surface that emulates physical paper. However, a variety of ergonomic factors make it difficult to fully achieve this goal. Examples of such factors include: slip; resolution; screen size; parallax; and device size and weight. Slip generally refers to the fact that pen-computing devices tend to be more slippery than real paper. Resolution takes into account that digital screens have less visual resolution than paper. In addition, digitizers usually track digital pens at lower resolution than the finest human hand movements. Parallax is a consequence of providing a protective layer of plastic over the screen, wherein the protective layer creates an apparent displacement between the tip of the digital pen and underlying document. Size and weight, including screen size, reflects design considerations for portable devices that result in devices and screens that are often smaller than standard letter-size paper and more difficult to position and interact with. While hardware designers continue to improve pen-based devices to make them feel more like paper, a substantial gap remains. Many limitations associated with these devices force users to change the way in which they interact with such devices and annotations often end up appearing very different from ink on paper. In particular, screens associated with such computing devices are usually smaller than a sheet of paper. Conventional techniques for fitting at least a portion of a page within a screen include adjusting the display resolution and/or “zoom.” However, these techniques involve scaling down text and/or graphics, which can render the document information unreadable. In addition, many devices can be hardware and/or software limited such that selecting a higher resolution is not an option. Another problem with scaling down text and/or graphics is that the user typically ends up annotating at a much larger size than they would on paper. The large size of the ink generally results in annotations that are less dense than real ink annotations on paper, consume limited screen real estate, obscure the underlying document, and appear clumsy. Conventional techniques that attempt to address writing scale versus display scale fail to emulate physical paper. For example, in many of these techniques, the user specifies a focus cursor in a main overview area at the top of the screen. Then, the user writes in a focus area at the bottom of the screen, wherein the annotations are reduced to a predefined percentage (e.g., 40%) of the original size and placed at the focus cursor. Upon filling the focus area, the user typically is required to perform a right to left movement in the focus area in order to move the focus cursor forward. With other techniques, the focus area constantly scrolls from right to left, thereby continuously clearing space for new annotations. Still with other techniques, the user is required to explicitly create new writing space when filling the focus area, which can break the flow of writing, or modify their writing style to work with the continuous scrolling writing area. Conventional techniques that employ zooming usually magnify a region of interest within an image or document such that the surrounding context is not visible after the zoom. Navigating in the zoomed view typically requires scrolling, which can be tedious when the magnification factor is high. Other approaches include a multi-scale view of the document, in which a magnified focus region shows details while the surrounding context remains visible. Navigation through the document is typically achieved by positioning a focus region (or lens) over the underlying document, for example, via panning and/or zooming. Although many conventional techniques attempt to provide a natural and expressive way to annotate documents and images with freeform digital ink (via a digital pen, mouse, etc.) these techniques do not overcome the aforementioned problems with annotating on small-screen devices like Tablets PCs, PDAs, cell phones and the like and fail to emulate writing on physical paper. | <SOH> SUMMARY OF THE INVENTION <EOH>The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later. The present invention provides a focus plus context-based interface that facilitates multi-scale navigation during digital document (e.g., word processing documents, images, etc.) annotating by microprocessor-based devices (e.g., desktop computers, Tablet PCs, PDAs and cell phones) with tools such as a digital pen, a mouse, etc. The systems and methods of the present invention provide an interface that zooms a region of an underlying document, wherein a user can enter annotations in the region at a size comfortable to the user and suitably scaled to the device display. This region can automatically adjust (e.g., location, size, shape, etc.), as needed, while the user annotates. When the zoom region is reduced back to the normal page size, the digital ink annotations scale to an appropriate size, based on the underlying document. The systems and methods of the present invention build upon free-form digital ink and zoomable user interfaces to provide a mobile zoom region that can be variously configured to automatically grow and/or move and only cover a subset of the screen so that a user can see the overall context of the underlying document, if desired. This novel feature provides advantages over conventional techniques that do not contemplate multi-scale navigation during document annotating. The subject invention employs various techniques based on a scale-space framework in order to fluidly place and move the zoom region with respect to the underlying document and the user's writing tool. These techniques enable quick and easy digital document annotation, wherein the resulting annotations closely mimic the look and feel of annotations on physical paper. In one aspect of the present invention, a system that facilitates document annotation within microprocessor-based devices is illustrated. The system comprises an annotation management component that generates annotation regions and an annotation configuration component that provides annotation region properties that are employed to generate the annotation regions. The annotation management component can be invoked to generate an annotation region from a user interface via an action, a sound, and/or automatically. The annotation management component can obtain annotation region configurations from an annotation configuration component and/or from the user or intelligence components. Such configuration information can define annotation region size, shape, location, appearance, etc., as well as navigation characteristics. The annotation region can be generated to occupy at least a subset of the viewing area and be positioned proximate an area of interest such that the user is provided with ample space to view document information and add annotations within the annotation region, as well as continue to view remaining portions of non-scaled document information. In addition, the annotation region typically scales the document information residing therein so that the user can comfortably add annotations that are relatively similar in size to the document information. The system further comprises a navigation component that provides navigation algorithms. As needed, the annotation region can be re-positioned and/or re-shaped via the algorithms to enable the user to add annotations essentially anywhere on the document. When the annotation region is closed, the document information can be scaled back to its original size and the annotations can be scaled by a similar factor or a different factor, depending on the properties provided by the annotation configuration. In another aspect of the present invention, a methodology that facilitates annotating a digital document is illustrated. The methodology comprises activating a zoomable user interface, or zoom window, for example, with a digital pen via tapping at a point on a display. The zoom window can be generated proximate this point and can provide a magnified view of the document lying below the zoom window. Animation can be employed to generate this zoom window. After the zoom window is generated, a user can annotate the underlying document via the zoom window, for example, by writing within the zoom window. The zoom window can be utilized to annotate various regions of the document by moving the zoom window to desired locations prior to and during annotating the document. The user can close the zoom window, wherein document content as well as the annotations can scale to a size consonant with the underlying document. In yet other aspects of the present invention, document annotation methodologies based on a space-scale framework are illustrated. The methodologies are utilized to position and navigate a zoom window while annotating a document. In one instance, the zoom window automatically adjusts, as needed, to provide the user with seamless and unobstructed annotation capabilities. In another instance, the document is moved relative to the zoom window. In yet another instance, the zoom window is moved relative to the underlying document. Other aspects of the present invention illustrate annotation systems that employ intelligence to facilitate generation and management of a zoom window, examples of documents annotated with the novel aspects of the present invention, and various shapes that can be employed in accordance with aspects of the present invention. Moreover, environments are illustrated wherein the novel aspects of the present invention can be employed. To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects and implementations of the invention. These are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings. | 20040210 | 20090623 | 20050811 | 91358.0 | 0 | WANG, JIN CHENG | SYSTEMS AND METHODS THAT UTILIZE A DYNAMIC DIGITAL ZOOMING INTERFACE IN CONNECTION WITH DIGITAL INKING | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,775,874 | ACCEPTED | High resolution ink jet printhead | A high resolution printhead for an ink jet printer. The printhead includes a semiconductor substrate containing at least one ink feed edge and a plurality of ink ejection actuators spaced a distance from the ink feed edge. Each of the ink ejection actuators has an aspect ratio ranging from about 1.5:1 to about 6:1. A nozzle plate is attached to the semiconductor substrate. The nozzle plate contains a plurality of nozzle holes, ink chambers and ink channels laser ablated in the nozzle plate corresponding to the plurality of ink ejection actuators. Adjacent nozzle holes are spaced apart with a pitch ranging from about 600 to about 1200 dpi. The distance from the ink feed edge is substantially the same for each of the ink ejection actuators. | 1. A printhead for an ink jet printer, the printhead comprising: a semiconductor substrate containing at least one ink feed edge and a plurality of ink ejection actuators spaced a distance from the ink feed edge, each of the ink ejection actuators having an aspect ratio ranging from about 1.5:1 to about 6:1; a thick film layer attached to the semiconductor substrate, the thick film layer having formed therein a plurality of ink feed chambers and ink feed channels corresponding to the plurality of ink ejection actuators; and a nozzle plate attached to the thick film layer, the nozzle plate containing a plurality of nozzle holes in the nozzle plate corresponding to the plurality of ink feed chambers, wherein adjacent ones of the nozzle holes are spaced apart with a pitch ranging from about 600 to about 2400 dpi and wherein the distance from the ink feed edge is substantially the same for each of the ink ejection actuators. 2. The printhead of claim 1, wherein the ink ejection actuators comprise heater resistors. 3. The printhead of claim 2, wherein the heater resistors have a width of less than or equal to 15 microns. 4. The printhead of claim 2, wherein the heater resistors have a resistance ranging from about 80 to about 200 ohms. 5. The printhead of claim 1, wherein the nozzle holes comprise oblong nozzle holes having a long axis to diameter ratio greater than about 1.15. 6. The printhead of claim 1, wherein the ink feed edge comprises an ink feed slot, and wherein the plurality of ink ejection actuators are disposed on both sides of the ink feed slot. 7. The printhead of claim 1, wherein the ink feed edge comprises an ink feed slot, and wherein the semiconductor substrate contains two or more ink feed slots. 8. The printhead of claim 7, wherein the plurality of ink ejection actuators are disposed only on one side of each of the ink feed slots. 9. The printhead of claim 1, wherein a distance from the ink ejection actuators to an exit of the nozzle holes is greater than the pitch. 10. The printhead of claim 1, wherein a ratio of the pitch to a distance from the ink ejection actuators to an exit of the nozzle holes ranges from about 0.5 to about 1.5. 11. An inkjet printer cartridge containing the printhead of claim 8. 12. A printhead for an ink jet printer comprising: a semiconductor substrate containing at least one ink feed edge and a plurality of ink ejection actuators spaced a distance from the ink feed edge, each of the ink ejection actuators having an aspect ratio ranging from about 1.5:1 to about 6:1; and a nozzle plate attached to the semiconductor substrate, the nozzle plate containing a plurality of nozzle holes, ink chambers and ink channels laser ablated in the nozzle plate corresponding to the plurality of ink ejection actuators, wherein adjacent nozzle holes are spaced apart with a pitch ranging from about 600 to about 1200 dpi and wherein the distance from the ink feed edge is substantially the same for each of the ink ejection actuators. 13. The printhead of claim 12, wherein ejection actuators comprise heater resistors and the heater resistors have a resistance ranging from about 80 to about 200 ohms. 14. The printhead of claim 12, wherein the nozzle holes comprise bicircular nozzle holes. 15. The printhead of claim 12, wherein the ink feed edge comprises an ink feed slot, and wherein the plurality of ink ejection actuators are disposed on both sides of the ink feed slot. 16. The printhead of claim 12, wherein the ink feed edge comprises an ink feed slot, and wherein the semiconductor substrate contains two or more ink feed slots. 17. The printhead of claim 16, wherein the plurality of ink ejection actuators are disposed only on one side of each of the ink feed slots. 18. An ink jet printer cartridge containing the printhead of claim 15. 19. An ink jet printer cartridge containing the printhead of claim 16. 20. A printhead for a thermal ink jet printer, the printhead comprising: a semiconductor substrate containing at least one ink feed edge and a plurality of heater resistors spaced a distance from the ink feed edge, each of the heater resistors having a resistance ranging from about 80 to about 200 ohms; a thick film layer attached to the semiconductor substrate, the thick film layer having formed therein a plurality of ink feed chambers and ink feed channels corresponding to the plurality of ink ejection actuators; and a nozzle plate attached to the thick film layer, the nozzle plate containing a plurality of nozzle holes in the nozzle plate corresponding to the plurality of ink feed chambers, wherein adjacent nozzle holes are spaced apart with a pitch ranging from about 600 to about 2400 dpi and wherein the distance from the ink feed edge is substantially the same for each of the heater resistors. 21. The printhead of claim 20 wherein each of the heater resistors has an aspect ratio ranging from about 1.5:1 to about 6:1. 22. The printhead of claim 20, wherein the ink feed edge comprises an ink feed slot, and wherein the plurality of heater resistors are disposed on both sides of the ink feed slot. 23. The printhead of claim 20, wherein the ink feed edge comprises an ink feed slot, and wherein the semiconductor substrate contains two or more ink feed slots. 24. The printhead of claim 23, wherein the plurality of heater resistors are disposed only on one side of each of the ink feed slots. 25. An inkjet printer cartridge containing the printhead of claim 20. 26. A printhead for a thermal inkjet printer, the printhead comprising: a semiconductor substrate containing at least one ink feed edge and a plurality of heater resistors spaced a distance from the ink feed edge, each of the heater resistors having a resistance ranging from about 80 to about 200 ohms; a nozzle plate attached to the semiconductor substrate, the nozzle plate containing a plurality of nozzle holes, ink chambers and ink channels laser ablated in the nozzle plate corresponding to the plurality of ink ejection actuators, wherein adjacent nozzle holes are spaced apart with a pitch ranging from about 600 to about 1200 dpi and wherein the distance from the ink feed edge is substantially the same for each of the heater resistors. 27. The printhead of claim 26 wherein each of the heater resistors has an aspect ratio ranging from about 1.5:1 to about 6:1. 28. The printhead of claim 26, wherein the ink feed edge comprises an ink feed slot, and wherein the plurality of heater resistors are disposed on both sides of the ink feed slot. 29. The printhead of claim 26, wherein the ink feed edge comprises an ink feed slot, and wherein the semiconductor substrate contains two or more ink feed slots. 30. The printhead of claim 29, wherein the plurality of heater resistors are disposed only on one side of each of the ink feed slots. 31. An ink jet printer cartridge containing the printhead of claim 26. | FIELD OF THE INVENTION The invention relates to ink jet printheads and in particular to ink jet printheads having increased resolution and methods for making the printheads. BACKGROUND OF THE INVENTION Ink jet printers continue to experience wide acceptance as economical replacements for laser printers. Such ink jet printers are typically more versatile than laser printers for some applications. As the capabilities of ink jet printers are increased to provide higher quality images at increased printing rates, printheads, which are the primary printing components of ink jet printers, continue to evolve and become more complex. Improved print quality requires that the printheads provide an increased number of ink droplets. In order to increase the number of ink droplets from a printhead, printheads are designed to include more nozzles and corresponding ink ejection actuators. The number of nozzles and actuators for a “top shooter” or “roof shooter” printhead can be increased in several ways known to those skilled in the art. For example, in an integrated nozzle plate containing nozzle holes, ink chambers, and ink channels laser ablated in a polyimide material, adjacent nozzles and corresponding ink chambers are typically offset from one another in a direction orthogonal to the ink feed slot. Such a design results in adjacent nozzles having different fluidic characteristics such as refill times which can result in quality defects and can limit high frequency operation of the ejector actuators. The offset is primarily due to laser ablation of the nozzle plate material to form the ink chambers. With a laser ablated nozzle plate containing ink chambers and ink channels, a minimum spacing between adjacent ink chambers is required to provide sufficient chamber wall structure for the ink chambers. Hence, a larger nozzle plate and corresponding semiconductor substrate is required as the number of nozzles and actuators for the printhead is increased. Despite the advances made in the art of ink jet printheads, there remains a need for printheads having higher resolution that can operate at higher ejection frequencies without substantially increasing the cost for producing such printheads. SUMMARY OF THE INVENTION With regard to the foregoing and other objects and advantages there is provided a high resolution printhead for an ink jet printer. The printhead includes a semiconductor substrate containing at least one ink feed edge and a plurality of ink ejection actuators spaced a distance from the ink feed edge. Each of the ink ejection actuators has an aspect ratio ranging from about 1.5:1 to about 6:1. A nozzle plate is attached to the semiconductor substrate by use of an adhesive or preferably an adhesive and an intermediate polymeric layer. The nozzle plate contains a plurality of nozzle holes, ink chambers and ink channels laser ablated in the nozzle plate corresponding to the plurality of ink ejection actuators. Adjacent nozzle holes are spaced apart with a pitch ranging from about 600 to about 1200 dpi. The distance from the ink feed edge is substantially the same for each of the ink ejection actuators. In another embodiment there is provided a printhead for an ink jet printer. The printhead includes a semiconductor substrate containing at least one ink feed edge and a plurality of ink ejection actuators spaced a distance from the ink feed edge. Each of the ink ejection actuators has an aspect ratio ranging from about 1.5:1 to about 6:1. A thick film layer is attached to the semiconductor substrate. The thick film layer has formed therein a plurality of ink feed chambers and ink feed channels corresponding to the plurality of ink ejection actuators. A nozzle plate is attached to the thick film layer. The nozzle plate contains a plurality of nozzle holes laser ablated in the nozzle plate corresponding to the plurality of ink feed chambers. Adjacent nozzle holes are spaced apart with a pitch ranging from about 600 to about 2400 dpi. The distance from the ink feed edge is substantially the same for each of the ink ejection actuators. An advantage of the invention is that it provides printheads having increased print resolution without decreasing the firing frequency and without significantly increasing the size of the printhead components. The invention also enables production of printheads having a nozzle pitch of greater than 600 dpi without the need to provide adjacent nozzles and corresponding ink chambers that are offset from one another in a direction orthogonal to the ink feed slot. Accordingly, the fluidic characteristics of each of nozzles are substantially the same. For purposes of this invention, the term “pitch” as it is applied to nozzles or ink ejection actuators is intended to mean a center to center spacing between adjacent nozzles or ejection actuators in a direction substantially parallel with an axis aligned with a columnar nozzle array. The term “aspect ratio” as it applies to the ink ejection actuators is the ratio of the length of the actuators to the width of the actuators. BRIEF DESCRIPTION OF THE DRAWINGS Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the following drawings illustrating one or more non-limiting aspects of the invention, wherein like reference characters designate like or similar elements throughout the several drawings as follows: FIG. 1 is a ink jet printer cartridge, not to scale, containing a printhead according to the invention; FIG. 2 is a perspective view of an ink jet printer according to the invention; FIG. 3 is a plan view, not to scale, of a printhead containing according to the invention; FIG. 4 is a cross-sectional view, not to scale of a portion of a printhead according to one embodiment of the invention; FIG. 5 is a plan view, not to scale, of a portion of a prior art printhead; FIG. 6 is a plan view, not to scale, of a portion of a printhead according to the invention; FIG. 7 is a cross-sectional view, not to scale of a portion of a printhead according to another embodiment of the invention; and FIG. 8 is a schematic illustration of a nozzle hole entrance or exit according to an embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION With reference to FIGS. 1-3, an ink jet printer cartridge 10 containing a printhead 16 for an ink jet printer 12 is illustrated. The cartridge 10 includes a cartridge body 14 for supplying a fluid such as ink to the printhead 16. The fluid may be contained in a storage area in the cartridge body 14 or may be supplied from a remote source to the cartridge body 14. The printhead 16 includes a semiconductor substrate 18 and a nozzle plate 20 containing nozzle holes 22 attached to the substrate 18, or in another embodiment, attached to a thick film layer on the substrate. It is preferred that the cartridge 10 be removably attached to the ink jet printer 12. Accordingly, electrical contacts 24 are provided on a flexible circuit 26 for electrical connection to the ink jet printer 12. The flexible circuit 26 includes electrical traces 28 that are connected to the substrate 18 of the printhead 16. An enlarged cross-sectional view, not to scale, of a portion of a printhead 16 according to one embodiment of the invention is illustrated in FIG. 4. In this embodiment, the printhead 16 contains a thermal heating element 30 for heating the fluid in a fluid chamber or ink chamber 32 formed in the nozzle plate 20 between the substrate 18 and the nozzle hole 22. However, the invention is not limited to a printhead 16 containing a thermal heating element 30. Other fluid ejection devices or ink ejection actuators, such as piezoelectric devices may also be used to provide a printhead according to the invention. Fluid for ejection by the printhead 16 through nozzle holes 22 is preferably provided to the fluid chamber 32 through an opening or slot 34 in the substrate 18 and through a fluid channel 36 connecting the slot 34 with the fluid chamber 32. The nozzle plate 20 is preferably adhesively attached to the substrate 18 as by adhesive layer 38. In a particularly preferred embodiment, the printhead is a thermal or piezoelectric ink jet printhead. However, the invention is not intended to be limited to ink jet printheads as other fluids may be ejected with a micro-fluid ejecting device according to the invention. Also the invention is not limited to a printhead having a fluid feed slot 34 in the substrate 18. A fluid may also be caused to flow around opposed outer edges of the substrate 18 and into the fluid channel 36 and fluid chamber 32. Accordingly, a fluid feed edge 40 is provided which may be an edge of the feed slot 34, or in the case of an edge feed configuration, an outer edge of the substrate 18. In the embodiment illustrated in FIG. 4, the ink chamber 32 and ink channel 36 are formed in the nozzle plate 20 as by laser ablation. Laser ablation of the nozzle plate 20 is typically conducted from the ink chamber side of the nozzle plate 20. When the nozzle plate 20 is made of a polyimide material, walls 42 of the ink chamber 32 and walls 44 of the nozzle 22 have sloping or angled surfaces due to the laser ablation process. In a prior art design of a printhead, illustrated in FIG. 5, the center to center distance S1 between adjacent nozzles 46 and 48 was typically about 42 microns or more to provide a pitch of less than about 600 dpi (dots per inch) along a direction (A) parallel to an ink feed edge 54. In the prior art design illustrated in FIG. 5, nozzle holes 46 and 48 are staggered providing staggered ink chambers 50 and 52 to provide closer spacing S1 between adjacent nozzles. By “staggered” it is meant that a center of nozzle 46 is a distance T1 that is less than a distance T2 of a center of nozzle 48 to the ink feed edge 54. In many conventional prior art designs, the aspect ratio (L1/W1) of ink ejection actuators 56 is typically less than about 1.5:1. In order to provide a fluidic seal between adjacent ink chambers such as chambers 50 and 52, a distance F1 ranging from about 7.5 to about 30 microns between adjacent ink chambers is required for a laser ablated nozzle plate considering manufacturing alignment tolerances. Also a distance G1 ranging from about 0 to about 10 microns between an inside chamber wall 58 and the ink ejector 56 is typically required for a laser ablated nozzle plate. Accordingly, the pitch S1 between adjacent nozzles is a function of F1 and G1 and the aspect ratio of the ink ejection devices. It will be appreciated that the fluidic characteristics of nozzle 46 differ from the fluidic characteristics of nozzle 48 because nozzle 48 is farther from ink feed edge 54 than nozzle 46. It will also be appreciated that providing a substantially non-staggered array of nozzles in a laser ablated nozzle plate with a pitch of greater than 600 dpi or a spacing of less than 42 microns between adjacent nozzles 46 and 48 is desirable in order to increase print resolution and print quality with a higher ink ejection rate or firing frequency. With the design illustrated in FIG. 5, the firing frequency of the nozzles is limited by the fluid fill rate of the ink chambers 52 spaced farther from the ink feed edge 54. A portion of a printhead 16 according to one embodiment of the invention is illustrated in plan view, not to scale, in FIG. 6. According to the invention, a substantially linear array 60 of ink ejection nozzles 22 is provided. Unlike the prior art design illustrated in FIG. 5, the ink chambers 32 are spaced substantially the same distance T3 from the ink feed edge 40 so that the fluidic characteristics of each nozzle 22 are substantially the same. The term “substantially the same” with respect to the distance of the ink chambers 32 from the edge means that the difference in distance from the chambers 32 in each column of chambers 32 is less than or equal to a length L2 (FIG. 6) of the ink ejection devices 30. In a preferred embodiment T3 preferably ranges from about 20 to about 90 microns. Also unlike the prior art design, the center to center spacing S2 between adjacent nozzles 22 is preferably less than 42 microns providing a pitch of greater than about 600 dpi up to about 1200 dpi for ablated ink chambers and up to about 2400 dpi for photodeveloped ink chambers along a direction B of the linear array 60 of nozzles. In a preferred embodiment S2 preferably ranges from less than 42 microns to about 10.5 microns. As described above, there is a minimum distance F2 between adjacent ink chambers for a laser ablated nozzle plate to provide sufficient chamber wall structures for fluidic sealing between adjacent ink chambers. Distance F2 preferably ranges from about 6 to about 30. Also, alignment tolerances between an inside chamber wall 62 and ink ejection device 30 require a spacing of G2 which preferably ranges from about 0 to about 10. This is particularly true for an alignment tolerance (NA) between the chamber wall 62 and the ink ejection device 30 of about 9 microns. In a laser ablated nozzle plate containing laser ablated ink chambers 32 and ink channels, G1=G2 and F1=F2. In another embodiment, described below, G1≧G2 and F1≧F2. In order to provide a closer spacing between adjacent nozzles 22 sufficient to increase the pitch to greater than about 600 dpi, the aspect ratio of the ink ejection devices 30 is selected such that the aspect ratio (L2/W2) ranges from about 1.5:1 to about 6:1, preferably from about 2:1 to about 4.5:1. Such aspect ratio enables use of a heater resistor as the ink ejection device having a resistance ranging from about 80 to about 200 ohms or more with conventional heater resistor material. In this case, the nozzle 22 to chamber 32 alignment tolerance (NC) is about 2 microns. For a laser ablated nozzle plate 20, referring to FIGS. 4 and 6, the following relationships can be used to select the center to center spacing S2: (2×a)+ED+F2=S2 (1) where (a) is the distance between the bottom of the chamber wall 42 and an entrance 64 of the nozzle 22, ED is the entrance diameter at the entrance 64 of the nozzle 22, and F2 is the spacing between adjacent chambers 32. The entrance diameter (ED) of the nozzle 22 directly affects the drop size ejected by the nozzle 22 and is therefore normally fixed by product requirements. The distance (a) from the entrance 64 of the nozzle 22 to the chamber wall 42 is a function of the nozzle to chamber alignment tolerance (NC) and the wall angle of the chamber wall 42 caused by laser ablation providing a distance (c) between the top and bottom of the chamber wall. During laser ablation, the wall angle of the chamber wall typically ranges from about 6° to about 18°. Accordingly, the distance (a) must be greater than the nozzle to chamber alignment tolerance (NC) plus (c) according to the following inequality: a>NC+c. (2) In order for the nozzles 22 of the nozzle plate 20 to be aligned to the ink ejection devices 30, the distance (G2) between the ink ejection device 30 and the chamber wall 42 must be greater than the alignment tolerance (NA) between the chamber wall 62 and the ink ejection device 30 according to the following inequality: a>NA+W2/2−ED/2 (3) where W2 is the width of the ink ejection device 30. The foregoing equations assume that the wall angle for the nozzle 22 is about 7° between the entrance and exit of the nozzle 22. For a center to center spacing S2 between adjacent nozzles 22 of less than 600 dpi up to about 1200 dpi, the heater width W2 preferably ranges from about 7 to about 15 microns. In order to reduce the alignment tolerances and further decrease the nozzle to nozzle spacing, a printhead 66 according to another embodiment of the invention is illustrated in FIG. 7. In this embodiment, a nozzle plate 68 is formed separate from a thick film layer 70. The thick film layer 70 is preferably provided by a photoresist material that is spin coated or laminated to substrate 72. The thick film layer 70 has a thickness ranging from about 6 to about 30 microns and is preferably photodeveloped to provide ink chambers 74 and ink channels 76 therein. As described above, the substrate 72 includes an ink feed edge 78 that may be provided by an ink feed slot 80 provided in the substrate 72. Ink ejection devices 82 are formed on the substrate 72 and are aligned with a nozzle 84 provided in the nozzle plate 68. The nozzles 84 are preferably laser ablated in the nozzle plate 68 as described above. In this embodiment, side wall 86 of the ink chamber 74 is formed with less of an angle than the side wall 42 of the laser ablated nozzle plate 20. Accordingly, the center to center spacing S2 between adjacent nozzles 84 can be reduced and the following relationship can be used to determine the center to center spacing between adjacent nozzles 84: S2=W2+(2×G2)+F2 (4) since the effects of the laser ablated chamber wall 42 have been reduced or eliminated from the design. In this embodiment, the heater width W2 may range from 5.5 to about 25 microns. In order to provide a suitable ink ejection device 30 or 82, the aspect ratio (L2/W2) of the ejection device 30 or 82 preferably ranges from 1.5:1 to 6:1 as described above. Given this aspect ratio, the ink chamber 32 or 74 and the associated nozzle 22 or 84 preferably is adjusted to provide a suitable volume of ink ejected from the nozzle 22 or 84. A preferred nozzle design for embodiments of the invention is illustrated in FIG. 8 and comprises a substantially oblong nozzle. A preferred oblong nozzle 88 has an entrance and exit shape that is referred to herein as “bicircular.” A bicircular nozzle 88 is composed of two semicircular segments 90 and 92 having a diameter D3 and a rectangular segment 94 having a width W3 and length L3 equal to the diameter D3. With respect to the exit dimensions of the nozzle 88, D3 preferably ranges from about 5 to about 30 microns. The width W3 preferably ranges from about 1 to about 25 microns, and L3 has preferably the same dimension as D3. The entrance dimensions of the nozzles 88 are similar to the exit dimensions of the nozzles 88, however the exit diameter D3 is smaller than the corresponding entrance diameter, while the width W3 is the same for the entrance and the exit of the nozzle 88. The long axis L4 of the nozzle 88 is preferably aligned with the length L2 of the ink ejection device 82. Long axis L4 preferably ranges from about 10 to about 50 microns for the exit of the nozzle 88. It is preferred that the ratio of W3/D3 be greater than about 0.15. It is also preferred that the ratio of L4/D3 be greater than about 1.15. The amount of ink discharged is also a function of the distance H from the surface of the ink ejection device 82 to exit of the nozzle 84 (FIG. 7). The distance H preferably ranges from about 25 to about 55 microns. Given the nozzle center to center spacing S2, it is preferred that the spacing S2 be less than the distance H. It is particularly preferred that the ratio of S2/H be less than about 1.5 when S2 is less than 42 microns. While the foregoing embodiments have been described in terms of a nozzle plate or a nozzle plate and thick film layer, it will be appreciated that the ink chambers and ink channels may be formed exclusively in either the nozzle plate or thick film layer, or may be formed in both the nozzle plate and thick film layer. Formation of the ink chamber and ink channel in both the nozzle plate and thick film layer enables a greater degree of variation in the distance H to be achieved while providing suitable flow and ink ejection characteristics. It is contemplated, and will be apparent to those skilled in the art from the preceding description and the accompanying drawings, that modifications and changes may be made in the embodiments of the invention. Accordingly, it is expressly intended that the foregoing description and the accompanying drawings are illustrative of preferred embodiments only, not limiting thereto, and that the true spirit and scope of the present invention be determined by reference to the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Ink jet printers continue to experience wide acceptance as economical replacements for laser printers. Such ink jet printers are typically more versatile than laser printers for some applications. As the capabilities of ink jet printers are increased to provide higher quality images at increased printing rates, printheads, which are the primary printing components of ink jet printers, continue to evolve and become more complex. Improved print quality requires that the printheads provide an increased number of ink droplets. In order to increase the number of ink droplets from a printhead, printheads are designed to include more nozzles and corresponding ink ejection actuators. The number of nozzles and actuators for a “top shooter” or “roof shooter” printhead can be increased in several ways known to those skilled in the art. For example, in an integrated nozzle plate containing nozzle holes, ink chambers, and ink channels laser ablated in a polyimide material, adjacent nozzles and corresponding ink chambers are typically offset from one another in a direction orthogonal to the ink feed slot. Such a design results in adjacent nozzles having different fluidic characteristics such as refill times which can result in quality defects and can limit high frequency operation of the ejector actuators. The offset is primarily due to laser ablation of the nozzle plate material to form the ink chambers. With a laser ablated nozzle plate containing ink chambers and ink channels, a minimum spacing between adjacent ink chambers is required to provide sufficient chamber wall structure for the ink chambers. Hence, a larger nozzle plate and corresponding semiconductor substrate is required as the number of nozzles and actuators for the printhead is increased. Despite the advances made in the art of ink jet printheads, there remains a need for printheads having higher resolution that can operate at higher ejection frequencies without substantially increasing the cost for producing such printheads. | <SOH> SUMMARY OF THE INVENTION <EOH>With regard to the foregoing and other objects and advantages there is provided a high resolution printhead for an ink jet printer. The printhead includes a semiconductor substrate containing at least one ink feed edge and a plurality of ink ejection actuators spaced a distance from the ink feed edge. Each of the ink ejection actuators has an aspect ratio ranging from about 1.5:1 to about 6:1. A nozzle plate is attached to the semiconductor substrate by use of an adhesive or preferably an adhesive and an intermediate polymeric layer. The nozzle plate contains a plurality of nozzle holes, ink chambers and ink channels laser ablated in the nozzle plate corresponding to the plurality of ink ejection actuators. Adjacent nozzle holes are spaced apart with a pitch ranging from about 600 to about 1200 dpi. The distance from the ink feed edge is substantially the same for each of the ink ejection actuators. In another embodiment there is provided a printhead for an ink jet printer. The printhead includes a semiconductor substrate containing at least one ink feed edge and a plurality of ink ejection actuators spaced a distance from the ink feed edge. Each of the ink ejection actuators has an aspect ratio ranging from about 1.5:1 to about 6:1. A thick film layer is attached to the semiconductor substrate. The thick film layer has formed therein a plurality of ink feed chambers and ink feed channels corresponding to the plurality of ink ejection actuators. A nozzle plate is attached to the thick film layer. The nozzle plate contains a plurality of nozzle holes laser ablated in the nozzle plate corresponding to the plurality of ink feed chambers. Adjacent nozzle holes are spaced apart with a pitch ranging from about 600 to about 2400 dpi. The distance from the ink feed edge is substantially the same for each of the ink ejection actuators. An advantage of the invention is that it provides printheads having increased print resolution without decreasing the firing frequency and without significantly increasing the size of the printhead components. The invention also enables production of printheads having a nozzle pitch of greater than 600 dpi without the need to provide adjacent nozzles and corresponding ink chambers that are offset from one another in a direction orthogonal to the ink feed slot. Accordingly, the fluidic characteristics of each of nozzles are substantially the same. For purposes of this invention, the term “pitch” as it is applied to nozzles or ink ejection actuators is intended to mean a center to center spacing between adjacent nozzles or ejection actuators in a direction substantially parallel with an axis aligned with a columnar nozzle array. The term “aspect ratio” as it applies to the ink ejection actuators is the ratio of the length of the actuators to the width of the actuators. | 20040210 | 20061226 | 20050811 | 66777.0 | 3 | SOLOMON, LISA | HIGH RESOLUTION INK JET PRINTHEAD | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,775,892 | ACCEPTED | Filter element and mounting method | The present invention relates to an apparatus for filtering a gas or liquid stream such as a natural gas stream. The apparatus includes a closed vessel having a longitudinally extending length, an initially open interior, an input port at one extent and an output port at an opposite extent thereof. A partition located within the vessel interior divides the vessel interior into a first stage and a second stage. At least one opening is provided in the partition. A filter element is disposed within the vessel to extend from within the first stage. The filter element is easily mounted or removed from the vessel by rotating a J-slot engagement surface on the element which mates with a post provided on a mounting structure provided on the vessel partition. | 1. An apparatus for filtering a natural gas stream, the apparatus comprising: a closed vessel having a length and an initially open interior; a partition disposed within the vessel interior, the partition having a planar inner and planar outer side, respectively, dividing the vessel interior into a first stage and a second stage; at least one opening in the partition; an inlet port in fluid communication with the first stage; an outlet port in fluid communication with the second stage; at least one tubular filter element, the tubular filter element being disposed within the vessel to sealingly extend from within the first stage, the filter element having a locking end, a tubular length, and a handle end; a mounting structure located on a selected planar side of the partition; a rotational mounting means on the locking end of the at least one filter element which cooperates with the mounting structure of the vessel for rotationally locking the filter element with respect to the partition upon rotational movement of the filter element from the handle end. 2. The apparatus of claim 1, wherein each of the filter elements has a generally cylindrical locking end and wherein the mounting means on the locking end of the filter elements is a slot provided in the cylindrical locking end. 3. The apparatus of claim 2, wherein the mounting means on the locking end of the filter elements is a J-slot. 4. The apparatus of claim 1, wherein the generally cylindrical locking end of the filter elements joins the tubular length of the filter elements at a neck region of each filter element, the neck region forming a region of increased external diameter along the tubular length of the filter element, and wherein a seal means is located at the neck region for sealing against the partition when the filter element is locked in position. 5. The apparatus of claim 4, wherein the seal means is a chevron-shaped seal. 6. The apparatus of claim 4, wherein the seal means is an O-ring seal. 7. The apparatus of claim 3, wherein the mounting structure located on a selected side of the partition is a post which is aligned with respect to a partition opening and wherein the J-slot receives and engages the post as the filter element is rotated from the handle end. 8. The apparatus of claim 7, wherein the post is supported between opposing side flanges, the side flanges being arranged generally perpendicular to the selected planar face of the partition, whereby the post extends in a plane generally parallel to the plane of the selected planar face of the partition. 9. The apparatus of claim 3, wherein the mounting structure located on a selected side of the partition is a pair of spaced apart post elements which are aligned with respect to a partition opening and wherein the J-slot receives and engages the post elements as the filter element is rotated from the handle end. 10. The apparatus of claim 9, wherein the post elements are supported between opposing side flanges, the side flanges being arranged generally perpendicular to the selected planar face of the partition, whereby the spaced apart post elements extend in a plane generally parallel to the plane of the selected planar face of the partition. 11. The apparatus of claim 1, wherein the filter elements each have a filter wall and a hollow core. 12. The apparatus of claim 11, wherein the input port, the vessel interior, the tubular filter elements, and the output port together define a flow passage within the apparatus, whereby the gas stream flows into the first stage through the input port and through the filter wall of the filter element and out the hollow core, thereby separating impurities out of the gas stream, and whereby the gas stream then flows out of the second stage through the outlet port. 13. The apparatus according to claim 1, wherein each of the tubular filter elements consists of multi-overlapped layers of non-woven fabric strips. 14. A tubular filter element for filtering a natural gas stream passing through a filter vessel, the filter element comprising: a body having a locking end, a tubular length and a handle end; the tubular length of the filter body comprising a filter wall having a plurality of overlapped layers of non-woven fabric strips, the filter body also having a hollow core; a rotational mounting means on the locking end of the filter element which cooperates with a mating mounting structure provided within the filter vessel for rotationally locking the filter element with respect to the mounting structure upon rotational movement of the filter element from the handle end. 15. The filter element of claim 14, wherein the locking end of the filter elements are generally cylindrical locking ends and wherein the mounting means on the locking end of the filter elements is a slot provided in the cylindrical locking end. 16. The filter element of claim 15, wherein the mounting means on the locking end of the filter elements is a J-slot. 17. The filter element of claim 15, wherein the generally cylindrical locking end of the filter elements join the tubular length of the filter elements at a neck region of each filter element, the neck region forming a region of increased external diameter along the tubular length of the filter element, and wherein a seal means is located at the neck region for sealing against the mounting structure when the filter element is locked in position. 18. The filter element of claim 17, wherein the seal means is a chevron-shaped seal. 19. The filter element of claim 17, wherein the seal means is an O-ring seal. 20. A method of filtering solids from a natural gas stream, the method comprising the steps of: providing a filter vessel having a first stage and a second stage, the first stage being separated from the second stage by a partition having at least one opening; installing at least one replaceable filter element within the filter vessel, the filter element being sealed within the opening in the partition, the filter element having a locking end, a tubular length, and a handle end; providing a mounting structure located on a selected planar side of the partition; providing a rotational mounting means on the locking end of at least selected filter elements which cooperates with the mounting structure of the vessel for rotationally locking the filter element with respect to the mounting structure upon rotational movement of the filter element from the handle end; filtering solids from the gas stream in the first stage; and passing the gas stream from the filter element to the second stage. 21. The method of claim 20, wherein the filter elements are provided with generally cylindrical locking ends and wherein the mounting means on the locking end of the filter elements is a slot provided in the cylindrical locking end. 22. The method of claim 21, wherein the mounting means on the locking end of the filter elements is a J-slot. 23. The method of claim 21, wherein the generally cylindrical locking end of the filter elements join the tubular length of the filter elements at a neck region of each filter element, the neck region forming a region of increased external diameter along the tubular length of the filter element, and wherein a seal means is located at the neck region for sealing against the partition when the filter element is locked in position. 24. The method of claim 23, wherein the seal means is a chevron-shaped seal. 25. The method of claim 23, wherein the seal means is an O-ring seal. 26. A method of maintaining a filter vessel having associated tubular filter elements, the filter vessel having a first stage and a second stage, the first stage being separated from the second stage by a partition having at least one opening through which the filter elements are sealingly disposed, the method comprising the steps of: opening the multi-stage vessel; removing at least one filter element from the filter vessel; replacing the filter element with a replacement filter element; creating a fluid-tight seal between the replacement filter element and the opening; closing the multi-stage vessel; and wherein the filter element is provided with a locking end, a tubular length, and a handle end; a mounting structure is located on a selected planar side of the partition; a rotational mounting means is located on the locking end of at least selected filter elements which cooperates with the mounting structure of the vessel for rotationally locking the filter element with respect to the partition upon rotational movement of the filter element from the handle end. 27. The method of claim 26, wherein the step of creating a fluid-tight seal between the replacement element and the opening in the partition is achieved by using an O-ring seal positioned on the locking end of the filter element. 28. The method of claim 26, wherein the step of creating a fluid-tight seal between the replacement element and the opening in the partition is achieved by using a chevron-shaped seal positioned on the locking end of the filter element. 29. The method of claim 26, wherein the step of providing tubular filter elements consists of providing tubular filter elements having multi-overlapped layers of non-woven fabric strips. 30. An apparatus for filtering a natural gas stream, the apparatus comprising: a closed vessel having a length and an initially open interior; a partition disposed within the vessel interior, the partition having a planar inner and planar outer side, respectively, dividing the vessel interior into a first stage and a second stage; an inlet port in fluid communication with the first stage; an outlet port in fluid communication with the second stage; at least one opening in the partition sized to receive a locking end of a tubular filter element for supporting the filter element within the vessel; a mounting structure located on a selected planar side of the partition, the mounting structure comprising at least one post supported by side flanges so that the post lies in a plane which extends at least partly across the opening in the partition. 31. The apparatus of claim 30, wherein the post is selectively positioned with respect to the partition opening for matingly engaging a rotational mounting means provided on the locking end of the filter element for rotationally locking the filter element with respect to the partition and thereby supporting the filter element within the vessel interior. 32. The apparatus of claim 30, wherein the post is supported between opposing side flanges, the side flanges being arranged generally perpendicular to the selected planar face of the partition, whereby the post extends in a plane generally parallel to the plane of the selected planar face of the partition. 33. The apparatus of claim 30, wherein the mounting structure located on a selected side of the partition is a pair of spaced apart post elements which are aligned with respect to a partition opening. 34. The apparatus of claim 33, wherein the post elements are supported between opposing side flanges, the side flanges being arranged generally perpendicular to the selected planar face of the partition, whereby the spaced apart post elements extend in a plane generally parallel to the plane of the selected planar face of the partition. 35. The apparatus of claim 30, wherein a conventional filter element is retrofitted to be installed within the apparatus, the conventional filter element carrying mounting means for engaging the partition opening of the apparatus. 36. The apparatus of claim 35, wherein the mounting means is an element attachment rod which is carried by the conventional filter element. 37. The apparatus of claim 36, wherein the element attachment rod has an engagement end which engages the at least one post supported by the side flanges of the mounting structure of the apparatus. | BACKGROUND ART 1. Field of the Invention The invention relates to filter vessels used to filter gas and liquid streams such as natural gas and natural gas processing liquid streams and to filter elements for such vessels, and, more specifically, to an improved structure and method for mounting the filter elements within the interior of the associated filter vessel. 2. Description of Related Art Gas filter elements for filtering dry gas streams as well as for separating solids and liquids from contaminated gas streams are well known, as are gas filter elements for coalescing entrained liquids from a gas stream. Often these types of gas filter elements are installed in multi-stage vessels, which are in turn installed in a gas pipeline, to perform these filtering functions. U.S. Pat. No. 5,919,284, issued Jul. 6, 1999, and U.S. Pat. No. 6,168,647, issued Jan. 2, 2001, both to Perry, Jr., and assigned to the assignee of the present invention, disclose multi-stage vessels using individual separator/coalescer filter elements to separate solids, filter liquids, and coalesce liquids. The foregoing multi-stage vessels, as well as a multitude of other similar filtration vessels used in industry utilize solid or hollow core tubular elements, typically formed at least party of a porous filtration media. For example, porous filtration elements useful in the above type of filtration vessels are of the same general type as those that are described in U.S. Pat. No. 5,827,430, issued Oct. 27, 1998 to Perry, Jr., et al., and assigned to the assignee of the present invention. It is periodically necessary to perform maintenance on the filtration vessels, including replacement of the porous filter elements. This task has been labor intensive and time consuming in the past because of the mounting structure used to mount the filter elements within the filtration vessel interior. Often, it was necessary to unscrew and end cap or nut to free the filter element from its associated structural mounting within the vessel interior. Not only was this time consuming, but the location of the mounting structure was sometimes inconvenient to access, making filter replacement a difficult or inconvenient chore. The same type of inconveniences were present in the initial filter installation process for new filtration vessels. Thus, despite various advances which have been made in overall filtration vessel design, there continues to be a need for improvements which simplify the process of mounting and replacing filter elements within the filtration vessel, thereby decreasing the cost of vessel installation and maintenance. BRIEF SUMMARY OF THE INVENTION An apparatus is shown for filtering a gas or liquid stream such as a natural gas stream or a natural gas processing liquid stream. The apparatus includes a closed vessel having a length and an initially open interior. A partition is disposed within the vessel interior. The partition has a planar inner and planar outer side, respectively, dividing the vessel interior into a first stage and a second stage. At least one opening is provided in the partition. An inlet port is provided in fluid communication with the first stage. An outlet port also provides fluid communication from the second stage. At least one tubular filter element is disposed within the vessel to sealingly extend within the first stage. Each filter element has a locking end, a tubular length and a handle end. A mounting structure is located on a selected planar side of the partition. Rotational mounting means are provided on the locking end of at least selected filter elements which means cooperate with the mounting structure of the vessel for rotationally locking the filter element with respect to the partition upon rotational movement of the filter element from the handle end. Preferably, the locking end of the filter elements is a generally cylindrical surface which forms an end opening and the mounting means provided on the locking end of the filter elements is a slot provided in the cylindrical surface. The most preferred mounting means provided on the locking end of the filter element is a J-slot. The generally cylindrical locking end of the filter elements joins the tubular length of the filter elements at a neck region of each filter element. The neck region forms a region of increased external diameter along the tubular length of the filter element. A seal means is located at the neck region for sealing against the partition when the filter element is locked in a fully engaged position. The preferred seal means can comprise a chevron-shaped seal or an O-ring seal. The preferred mounting structure located on a selected side of the partition is a continuous post, or a pair of spaced post elements, aligned with respect to the partition opening, wherein the J-slot receives and engages the post or pair of post elements as the filter element is rotated from the handle end. The filter elements each have a filter wall and can have hollow cores. The input port, vessel interior, tubular filter elements and output port together define a flow passage within the apparatus. The gas stream flows into the first stage through the input port and through the outer filter wall of the filter element and through the hollow filter core, thereby separating impurities out of the gas stream. The gas stream then flows out of the second stage through the outlet port. The preferred tubular filter elements consist of multi-overlapped layers of non-woven fabric strips. A method is also shown for installing a filter element within a filtration vessel used to filter gas, liquid and gas/liquid streams. A filter vessel is provided as previously described having a first and second stage divided by a partition. At least one replaceable filter element is installed within the filter vessel. The filter element is provided with the previously described locking end, tubular length, and handle end. The filter element is installed within the vessel by rotationally locking the filter element with respect to the partition upon rotational movement of the filter element from the handle end. The above as well as additional objects, features, and advantages of the invention will become apparent in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view in partial section of a filter vessel having a filter element of the invention installed therein. FIG. 2A is partial, end view of a filter element of the invention showing the element engaged within the vessel mounting structure. FIG. 2B is an isolated view of the handle end of the filter element of the invention. FIG. 3A is a side, sectional view of a filter element of the invention shown disengaged from the associated vessel mounting structure, the filter element having a chevron-shaped seal. FIG. 3B is a view similar to FIG. 3A but with the filter element shown in the engaged position with respect to the vessel mounting structure. FIG. 4A is a view of an alternative filter element design showing an O-ring type seal for engaging the associated vessel mounting structure. FIG. 4B is a view of the filter element of FIG. 4A engaged with the vessel mounting structure. FIG. 5 is a view of a prior art filtration vessel showing the method of mounting the filter elements therein. FIG. 6 is a simplified, side view of a conventional filter element which is used in retrofit fashion within the filter vessel of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning to FIG. 1 there as shown a filter vessel of the invention designated generally as 13. The apparatus 13 is shown in its simplest form as a dry-gas filter. The internals or filter element shown in unit 13, illustrated in FIG. 1, would typically be followed by a second stage mist extractor of the type commercially available in the industry. While FIG. 1 illustrates one embodiment of a natural gas filtration vessel, it will be understood by those skilled in the art that the filter elements and method of mounting covered by the present invention can be applied to a variety of such vessels used in the industry. For example, the filter elements of the invention might be employed in vessels which are used for simultaneously filtering solids, separating liquids, pre-coalescing liquids, and coalescing liquids out of a gas stream. The filter elements might also be utilized in vessels used for coalescing and separating two liquids and for filtering solids out of liquids. Also, while the vessel shown in FIG. 1 illustrates one filter element mounted within the vessel for simplicity of illustration, it will be understood that some vessel designs will employ multiple elements utilizing the attachment means of the invention in a single vessel. Referring again to FIG. 1, it should be understood that although the vessel 13 is shown in a generally horizontal configuration, it may also be configured in a generally vertical embodiment. The vessel 13 has a generally tubular shell 15 having an initially open interior 17. The shell 15 is enclosed at an inlet end 19 by means of a closure member 21 which, in this case, is a bolted flange. The shell 15 is permanently enclosed at an outlet end 23 by a cap 25, preferably elliptical. The flanged closure 21 provides a fluid tight seal with respect to the inlet end 19. In the embodiment of FIG. 1, a single filter element 27 is supported within the vessel open interior 17 by means of a vessel partition 29 and support element 31. The support element 31 can comprise a flat bar or expanded metal. The partition 29 divides the hull interior into a first stage 35 and a second stage 33. The vessel 13 is preferably manufactured of steel materials which conform to published pressure-vessel standards, such as ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. The partition 29 which divides the vessel interior into the first and second filtration stages has a planar inner and planar outer opposing sides 37, 39, respectfully. At least one opening 41 is provided in the partition for receiving an end of the filter element. An inlet port 45 is in fluid communication with the first stage and an outlet port 43 is in communication with the second stage. The tubular filter element 27 is disposed within the vessel to sealingly extend within the first stage 35 through one of the openings 41 in the partition 29 into the second stage 33. Gas flow is through the inlet port 45, through the filter wall, of the filter element, through the hollow core 47 of the filter element, and through the second stage to the outlet 43. The direction of the gas flow is indicated by the arrows in FIG. 1. As best seen in FIGS. 3A and 3B, each tubular filter element 27 has a locking end 49, a tubular length and a handle end 51. As shown in FIG. 3A, a mounting structure is located on a selected planar side of the partition 29. A rotational mounting means is provided on the locking end 49 of the filter element 27 which cooperates with the mounting structure of the vessel for rotationally locking the filter element with respect to the partition 29 upon rotational movement of the filter element 27 from the handle end 51. Preferably, the filter element is provided with a generally cylindrical locking end 53 and the rotational mounting means on the locking end of the filter element is a slot 55 provided in the cylindrical surface of the locking end 53. The preferred mounting means on the locking end of the filter element is a J-slot, as illustrated in the drawings. The generally cylindrical locking end 53 of the filter element joins the tubular length of the filter element at a neck region 57. The neck region 57 forms a region of increased external diameter along the tubular length of the filter element. A seal means is located at the neck region for sealing against the partition 29 when the filter element 27 is locked in position. In the embodiment of the invention illustrated in FIGS. 3A and 3B, the seal means is an elastomeric chevron-shaped member 59. The chevron-shaped seal 59 is shown engaged against the partition planar inner side 37 in FIG. 3B. The exposed lip 60 of the seal member 59 acts as a resilient spring in holding the overall filter element in a “locked” or “seal engaged” position (illustrated in FIG. 3B). FIGS. 4A and 4B illustrate another embodiment of the filter element of the invention in which the neck region 57 carries an O-ring seal 61, the O-ring seal being received within a mating groove provided on the planar surface of the neck region. FIG. 4B shows the O-ring seal in engagement with the planar inner side 37 of the partition 29 when the element is in the locked in position. As shown in FIG. 3A, the mounting means which is provided on the partition 29 can comprise a continuous post 63 which is aligned with respect to a partition opening 41. As shown in FIG. 3B, the J-slot 55 provided in the cylindrical end 53 of the filter element receives and engages the post 63 as the filter element is rotated from the handle end 51. The post 63 is, in this case, supported between opposing side flanges 65, 67 which are arranged to generally perpendicular to the planar face 39 of the partition 29. In this way, the post 63 extends in a plane generally parallel to the plane of the selected planar face of the partition. As illustrated in FIGS. 4A and 4B, the mounting means which is provided on the partition 29 can also comprise two spaced-apart post elements 62, 64, with one post element being attached to each opposing side flange 65, 67. The discontinuity in the post 63 (shown in FIG. 3A) helps to reduce the flow restriction in the filter element outlet end caused by the presence of the mounting structure. FIGS. 2A and 2B illustrate the respective locking and handle ends of the filter element 27. FIG. 2A illustrates the rotational mounting means (J-slot 55) fully engaged with the mounting post 63. In this case, the post 63 is a continuous post which is supported between the opposing side flanges 65, 67, as described with respect to FIGS. 3A and 3B. The filter elements of the invention can be easily installed or removed from within the filter vessel 13. As shown in FIG. 1, the initially open interior 17 can be accessed by means of the closure 21. The filter element 27 can removed by simply turning the handle end 51. Rotational movement of the handle 51 causes the locking end 49 to rotate, whereby the J-slot rides about the post 63 (FIG. 2A), thereby releasing the element. The element can then be withdrawn from the vessel interior 17 by sliding the element longitudinally along the horizontal axis of the vessel and out the closure opening. A replacement filter element can then be easily installed by repeating the above steps in the reverse order. The filter vessel 13 can also be retrofitted with an existing, conventional filter element, such as the element 201 shown in FIG. 6. In the example illustrated, a single or double open end filter element 201 is provided with a sealing plate 203 at one extent. An element attachment rod 205 is secured to the sealing plate 203 by means of external nut 207 on one end and is supported within an opening 209 in the partition or tubesheet (29 in FIG. 1) by means of a flat bar 211 which fits across the tubesheet opening. It will be understood by one skilled in the art that other mounting means could also be utilized to mount a conventional filter element within the vessel of the invention. For example, the element attachment rod (205 in FIG. 6) could carry a transverse pipe in place of the flat bar 211 which pipe would have end openings which could be received over the spaced-apart posts (62 and 64 in FIG. 4A). Other types of engagement means could also be carried on the element attachment rod 205. The bodies, or tubular filter walls of the filter elements of the invention are preferably constructed in the manner and of the materials disclosed in U.S. Pat. No. 5,827,430, issued Oct. 27, 1998 to Perry, Jr., et al. A suitable filter element for use in the present invention is the PEACH™ filter commercially available from Perry Equipment Corporation of Mineral Wells, Texas. For example, in a typical application, the filter elements consist of four multi-overlapped layers of non-woven fabric strips of varying composition. The first layer is composed of equal amounts by volume of fibers purchased from Hoechst Celanese of Charlotte, N.C., United States, sold under the fiber designation “252,” “271,” and “224,” has a basis weight of 0.576 ounces per square foot, is ten inches wide, and is overlapped upon itself five times. The denier of fiber “252” is 3 and its length is 1.500 inches. The denier of fiber “271” is 15 and its length is 3.000 inches. The denier of fiber “224” is 6 and its length is 2.000 inches. The second layer is composed of equal amounts by volume of “252,” “271,” and “224,” has a basis weight of 0.576 ounces per square foot, is eight inches wide, and is overlapped upon itself four times. The third layer is composed of equal amounts by volume of “252,” “271,” and “224,” has a basis weight of 0.576 ounces per square foot, is eight inches wide, and is overlapped upon itself four times. The fourth layer is composed of equal amounts by volume of “252” and a fiber sold under the name “Tairilin,” has a basis weight of 0.576 ounces per square foot, is six inches wide, and is overlapped upon itself three times. Fiber “252” being of the core and shell type serves as the binder fiber in each of the aforementioned blends. The above example of particular types of material, fabric denier, number of wrapping layers, etc., is intended to be illustrative only of the type of preferred filter materials useful in the practice of the present invention. The rotational lock and release feature of the elements of the invention could be used with conventional filter materials, as well. The advantages of the improved filter elements and method of mounting thereof can perhaps best be understood with reference to the prior art filtration unit shown in FIG. 5 of the drawings. This vessel is described in issued U.S. Pat. No. 6,168,647, issued Jan. 2, 2001, and assigned to the assignee of the present invention. The discussion which follows also describes the filtration process in greater detail. The vessel 111, shown in FIG. 5, is best suited for mist collection. In addition, multi-stage vessel 111 is well suited for applications involving immiscible fluids, and as such, can be used in applications requiring the separation and filtration of two immiscible liquids or immiscible liquids and gases. The flow of the gas stream is indicated below as arrow G. Multi-stage vessel 111 has a generally tubular hull 112 having an initially open interior. Hull 112 is releasably enclosed on an upper inlet end 112a by a conventional closure member 115, preferably a quick-opening closure. Hull 112 is permanently enclosed on a lower outlet end 112b by a cap 113, preferably elliptical. Closure member 115 consists of a conventional head member 116 and a conventional clamping member 117. Head member 116 is releasably sealed to multi-stage vessel 111 by clamping member 117. Clamping member 117 may be released, and head member 116 may be opened to allow access to the interior of hull 112. Clamping member 117 provides a fluid-tight seal between hull 112 and head member 116, preferably with a conventional O-ring (not shown). A plurality of separator/coalescer filter elements 118 are disposed within hull 112. Separator/coalescer filter elements 118 are constructed as described above with respect to the vessel of the invention. Hull 112 is supported by support members 119. A conventional davit assembly supports head 116 when head 116 so that head 116 may be swung open to allow access to multi-stage vessel 111. The interior of hull 112 is divided into a first stage 121a and a second stage 121b by a generally transverse partition 123. Partition 123 includes a plurality of openings 125. A tubular filter guide 127 is aligned with each opening 125. Each filter guide 127 extends longitudinally a selected distance from partition 123 into first stage 121a. An inlet port 129 is disposed on hull 112 and opens into first stage 121a. Inlet port 129 terminates with an inlet flange 131. Inlet port 129 is located near partition 123 so that as a gas stream flows through the inlet port 129 into first stage 121a, the gas stream impinges upon filter guides 127. An outlet port 133 is disposed on hull 112 and opens into second stage 121b. Outlet port 133 terminates with an outlet flange 135. Outlet flange 135 is adapted to allow multi-stage vessel 111 to be connected to a conventional gas pipeline. An annular collar 136 is aligned with outlet port 133 and extends into second stage 121b. Disposed underneath portion 112c of hull 112 is a sump 139 for collecting the filtered solids, the separated liquids, the pre-coalesced liquids, and the coalesced liquids, that are removed from the gas stream. Sump 139 is divided into a first stage sump 139a and a second stage sump 139b by an impermeable sump partition 141. A first stage downcomer 143a provides fluid communication between first stage 121a and first stage sump 139a. The second stage downcomer 143b similarly provides fluid communication between second stage 121b and second stage sump 139b. A screen member 161 in the lower portion of the second stage 121b acts as a barrier to prevent coalesced liquids that have collected in the lower portion of the second stage from being re-entrained in the gas stream. A plurality of first stage support straps 165 are disposed in first stage 121a to support separator/coalescer filter elements 118. First stage support straps 165 generally extend transversely across first stage 121a and are connected to the interior of hull 112 by a snap fit or any suitable holding clip member. First stage support straps 165 include a plurality of apertures 166 to receive separator/coalescer filter elements 118 firmly in place without longitudinal compression. Likewise, a plurality of second stage support straps 167 are disposed in second stage 121b to support separator/coalescer filter elements 118. Second stage support straps 167 generally extend transversely across second stage 121b and are connected to the interior of hull 112. Second stage support straps 167 include a plurality of apertures 168 to receive separator/coalescer filter elements 118. The filter elements include filter cap posts 193a and 193b. A plurality of louvered impingement baffles 171 are disposed in second stage 121b to prevent coalesced liquids and fine liquids from becoming re-entrained in the gas stream as the gas stream flows through second stage 121b toward outlet port 133. A separate louvered impingement baffle 171 is associated with each separator/coalescer filter element 118 and each corresponding opening 125 in partition 123. Each louvered impingement baffle 171 includes a basket body portion 173 coupled to a basket cap portion 175. Each louvered impingement baffle 171 includes a plurality of annular louvers 177 disposed along the extent of basket body portion 173. It will be appreciated from the foregoing discussion that a more complicated mounting and support structure are required in the prior art device. The improved filter element and mounting method of the invention provides several advantages over such a structure. The improved filter elements of the invention utilize a rotational locking feature which allows the filter element to be easily installed or removed from the filter vessel interior. The simplicity of the J-slot locking mechanism simplifies the design of the element and associated mounting structure and provides improved efficiency during installation and maintenance operations. The filter locking design is simple in design and economical to manufacture. The locking mechanism is extremely reliable in operation. While the invention is shown in only one of its forms, it is not just limited but is susceptible to various changes and modifications without departing from the spirit thereof. | <SOH> BACKGROUND ART <EOH>1. Field of the Invention The invention relates to filter vessels used to filter gas and liquid streams such as natural gas and natural gas processing liquid streams and to filter elements for such vessels, and, more specifically, to an improved structure and method for mounting the filter elements within the interior of the associated filter vessel. 2. Description of Related Art Gas filter elements for filtering dry gas streams as well as for separating solids and liquids from contaminated gas streams are well known, as are gas filter elements for coalescing entrained liquids from a gas stream. Often these types of gas filter elements are installed in multi-stage vessels, which are in turn installed in a gas pipeline, to perform these filtering functions. U.S. Pat. No. 5,919,284, issued Jul. 6, 1999, and U.S. Pat. No. 6,168,647, issued Jan. 2, 2001, both to Perry, Jr., and assigned to the assignee of the present invention, disclose multi-stage vessels using individual separator/coalescer filter elements to separate solids, filter liquids, and coalesce liquids. The foregoing multi-stage vessels, as well as a multitude of other similar filtration vessels used in industry utilize solid or hollow core tubular elements, typically formed at least party of a porous filtration media. For example, porous filtration elements useful in the above type of filtration vessels are of the same general type as those that are described in U.S. Pat. No. 5,827,430, issued Oct. 27, 1998 to Perry, Jr., et al., and assigned to the assignee of the present invention. It is periodically necessary to perform maintenance on the filtration vessels, including replacement of the porous filter elements. This task has been labor intensive and time consuming in the past because of the mounting structure used to mount the filter elements within the filtration vessel interior. Often, it was necessary to unscrew and end cap or nut to free the filter element from its associated structural mounting within the vessel interior. Not only was this time consuming, but the location of the mounting structure was sometimes inconvenient to access, making filter replacement a difficult or inconvenient chore. The same type of inconveniences were present in the initial filter installation process for new filtration vessels. Thus, despite various advances which have been made in overall filtration vessel design, there continues to be a need for improvements which simplify the process of mounting and replacing filter elements within the filtration vessel, thereby decreasing the cost of vessel installation and maintenance. | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>An apparatus is shown for filtering a gas or liquid stream such as a natural gas stream or a natural gas processing liquid stream. The apparatus includes a closed vessel having a length and an initially open interior. A partition is disposed within the vessel interior. The partition has a planar inner and planar outer side, respectively, dividing the vessel interior into a first stage and a second stage. At least one opening is provided in the partition. An inlet port is provided in fluid communication with the first stage. An outlet port also provides fluid communication from the second stage. At least one tubular filter element is disposed within the vessel to sealingly extend within the first stage. Each filter element has a locking end, a tubular length and a handle end. A mounting structure is located on a selected planar side of the partition. Rotational mounting means are provided on the locking end of at least selected filter elements which means cooperate with the mounting structure of the vessel for rotationally locking the filter element with respect to the partition upon rotational movement of the filter element from the handle end. Preferably, the locking end of the filter elements is a generally cylindrical surface which forms an end opening and the mounting means provided on the locking end of the filter elements is a slot provided in the cylindrical surface. The most preferred mounting means provided on the locking end of the filter element is a J-slot. The generally cylindrical locking end of the filter elements joins the tubular length of the filter elements at a neck region of each filter element. The neck region forms a region of increased external diameter along the tubular length of the filter element. A seal means is located at the neck region for sealing against the partition when the filter element is locked in a fully engaged position. The preferred seal means can comprise a chevron-shaped seal or an O-ring seal. The preferred mounting structure located on a selected side of the partition is a continuous post, or a pair of spaced post elements, aligned with respect to the partition opening, wherein the J-slot receives and engages the post or pair of post elements as the filter element is rotated from the handle end. The filter elements each have a filter wall and can have hollow cores. The input port, vessel interior, tubular filter elements and output port together define a flow passage within the apparatus. The gas stream flows into the first stage through the input port and through the outer filter wall of the filter element and through the hollow filter core, thereby separating impurities out of the gas stream. The gas stream then flows out of the second stage through the outlet port. The preferred tubular filter elements consist of multi-overlapped layers of non-woven fabric strips. A method is also shown for installing a filter element within a filtration vessel used to filter gas, liquid and gas/liquid streams. A filter vessel is provided as previously described having a first and second stage divided by a partition. At least one replaceable filter element is installed within the filter vessel. The filter element is provided with the previously described locking end, tubular length, and handle end. The filter element is installed within the vessel by rotationally locking the filter element with respect to the partition upon rotational movement of the filter element from the handle end. The above as well as additional objects, features, and advantages of the invention will become apparent in the following detailed description. | 20040210 | 20060321 | 20050811 | 76264.0 | 0 | GREENE, JASON M | FILTER ELEMENT AND MOUNTING METHOD | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,776,355 | ACCEPTED | Quilting method and apparatus | A quilting apparatus for enabling a user to freely move a stack of fabric layers across a planar bed relative to an actuatable stitch head. The apparatus includes a motion detector which detects the movement of the stack and controls the actuation of the stitch head. Consequently, the apparatus functions to synchronize the delivery of stitch strokes by the head with the manually controlled movement of the quilt material stack. This frees the user to move the stack over a wide range of speeds, to start or stop movement at will, and to guide the stack in any direction across the planar bed. | 1. An apparatus for stitching together two or more stacked planar layers, said apparatus including: a stitch head mounted at a fixed location and actuatable to insert a stitch through a stack of two or more planar layers located beneath said stitch head; a substantially horizontally oriented bed for supporting said stack of planar layers for manually guided movement across said bed beneath said stitch head; detector means for detecting movement of a surface of said stack proximate to said stitch head for producing signals representing the magnitude of stack surface movement; and control circuit means responsive to said signals indicating stack surface movement exceeding a certain threshold for actuating said stitch head to insert a stitch through said stack. 2. The apparatus of claim 1 wherein said stitch head includes a needle mounted for reciprocal movement substantially perpendicular to said bed between a full up position and a full down position; and wherein said control circuit means for actuating said stitch head includes means for applying power to said stitch head to cause said needle to traverse one cycle from said full up position to said full down position to said full up position. 3. The apparatus of claim 2 wherein said means for applying power includes a motor/brake assembly operable in a motor mode for moving said needle and a brake mode for stopping movement of said needle. 4. The apparatus of claim 2 wherein said means for applying power includes a motor and a clutch/brake assembly; and wherein said clutch/brake assembly is operable in a clutch mode for coupling said motor to said stitch head for moving said needle and a brake mode to stop movement of said needle. 5. The apparatus of claim 1 wherein said bed defines a flat substantially horizontal surface for supporting said stack of planar layers; and wherein said stitch head includes a needle mounted for movement substantially perpendicular to said bed surface between a full up position and a full down position whereat it pierces said planar layers supported on said bed surface. 6. The apparatus of claim 5 wherein said control circuit means for actuating said head includes means for selectively applying power to said stitch head to cause said needle to move from said full up position to said full down position. 7. The apparatus of claim 6 further including means for returning said needle from said full down position to said full up position. 8. The apparatus of claim 1 wherein said detector means includes a light source for illuminating said stack surface; and means for processing light reflected from said illuminated layer for determining the magnitude of movement of said stack surface. 9. The apparatus of claim 1 wherein said detector means includes optical means for measuring movement of said stack surface along orthogonal X and Y axes; and signal processing means responsive to said measured movement for determining the magnitude of resultant movement of said stack; and wherein said control circuit means actuates said stitch head when the magnitude of said resultant movement exceeds a predetermined stitch length. 10. A machine for stitching at least one fabric layer, said machine comprising: an upper arm and a lower arm mounted in vertically spaced substantially parallel relationship to define a throat space therebetween; a substantially horizontally oriented plate on said lower arm for supporting said fabric layer for guided movement in said throat space; a needle arm supported from said upper arm above said plate actuatable to insert a stitch into said fabric layer; a detector for detecting movement of a surface of said fabric layer in said throat space; and control circuitry responsive to detected movement of said fabric layer surface for controlling actuation of said needle arm. 11. The machine of claim 10 wherein said detector operates to produce X and Y signals respectively representing the magnitude of translational movement of said fabric layer surface along perpendicular X and Y axes. 12. The machine of claim 10 wherein said detector operates to detect movement of said fabric layer surface without physically contacting said fabric layer. 13. The machine of claim 10 wherein said detector includes: a window oriented to collect energy from said fabric layer surface proximate to said plate; and signal processing means responsive to energy collected by said window for producing signals representing the magnitude of movement of said fabric layer across said plate. 14. The machine of claim 13 wherein said detector includes a source of energy for illuminating said fabric layer surface to reflect energy into said window. 15. The machine of claim 14 wherein said source of energy comprises a light source and said window collects light images reflected from said fabric layer surface. 16. The machine of claim 13 wherein said produced signals represent translational movement of said fabric layer surface along perpendicular X and Y axes. 17. The machine of claim 10 wherein said needle arm includes a needle mounted for cyclic movement between an up position spaced from said plate and a down position piercing said fabric layer proximate to said plate; and wherein said control circuitry is actuatable for moving said needle through at least one cycle comprising needle motion from said up position to said down position to said tip position. 18. The machine of claim 17 wherein said control circuitry includes a needle drive means for moving said needle through a cyclic movement in response to a certain magnitude of fabric layer movement detected by said detector. 19. The machine of claim 18 further including user means for adjusting the value of said certain magnitude. 20. The machine of claim 17 wherein said control circuitry includes a needle drive means for repeatedly cyclically moving said needle at a rate related to the speed of fabric layer surface movement detected by said detector. 21. A quilting apparatus for inserting stitches of uniform length through a stack of one or more fabric layers, said apparatus comprising: a stitch head; a bed defining a substantially horizontally oriented planar surface mounted opposite to said stitch head, said planar surface being configured to support said stack for guided movement across said planar surface; said stitch head including a needle operable to execute a cyclic movement from an up position remote from said planar surface to a down position piercing said stack on said planar surface, and back to said up position; a detector defining a window for collecting energy from a target area substantially coincident with a surface of said stack; and signal processing means responsive to said collected energy for indicating the magnitude of stack translational movement across said planar surface; and control means responsive to a translational movement of said stack of a magnitude exceeding a certain threshold for causing said needle to execute said cyclic movement. 22. The quilting apparatus of claim 21 wherein said detector includes: a light source mounted to illuminate said stack surface in said target area; and wherein said window is oriented to collect light images reflected from said target area. 23. A method of forming successive stitches of uniform length through a stack of fabric layers having top and bottom surfaces, said method comprising: mounting an actuatable stitch head at a fixed location; manually moving said stack of fabric layers across a horizontal planar surface under said stitch head; detecting the movement of at least one of said stack surfaces proximate to said stitch head; and actuating said stitch head in response to a certain magnitude of detected stack movement to insert a stitch through said stack of fabric layers. 24. The method of claim 23 wherein said step of mounting said stitch head includes mounting a needle for cyclic vertical movement between an up position spaced from said stack and a down position penetrating said stack moving across said planar surface. 25. The method of claim 23 wherein said step of detecting the movement of said stack includes: providing an energy source for illuminating a target area of a surface of said stack; collecting energy images reflected from said target area; and processing said collected energy images to determine the magnitude of movement of said stack. 26. The method of claim 23 wherein said step of actuating said stitch head includes moving said needle through a single cyclic movement in response to each increment of stack movement greater than said certain magnitude. 27. The method of claim 23 wherein said step of actuating said stitch head includes repeatedly cyclically moving said needle at a rate related to the speed of stack movement. 28. A method of forming successive stitches of uniform length through a stack of one or more fabric layers having top and bottom surfaces, said method comprising: providing a horizontally oriented planar surface for supporting said stack for guided movement across said planar surface; mounting a stitch head opposite to said planar surface where said stitch head is selectively actuatable to insert a stitch through said stack layers; manually moving said stack across said planar surface; optically observing a target area coincident with one of said stack surfaces to determine the magnitude of stack movement proximate to said planar surface; and responding to a magnitude of movement greater than a certain threshold for actuating said stitch head to insert a stitch into said stack. 29. The method of claim 28 wherein said step of moving said stack comprises a user manually grasping said fabric layers to push/pull said stack across said planar surface. 30. The method of claim 28 wherein said stack is mounted on a frame; and wherein said step of moving said stack comprises a user manually grasping said frame to push/pull said stack across said planar surface. 31. A quilting apparatus for inserting stitches into a stack of one or more fabric layers, said apparatus comprising: a stitch head; a bed defining a substantially horizontally oriented planar surface mounted opposite to said stitch head, said planar surface being configured to support said stack for guided movement of said stack across said planar surface; said stitch head including a needle operable to insert a stitch into said stack by executing a cyclic movement including a needle-up position remote from said planar surface and a needle-down position piercing said stack proximate to said planar surface; a detector for measuring the movement of said stack across said planar surface proximate to said stitch head; and control means for causing said needle to execute cyclic movements at a rate substantially proportional to the rate of stack movement measured by said detector. 32. The apparatus of claim 31 wherein said detector operates to measure the magnitude of translational movement of said stack along orthogonal directions. 33. The apparatus of claim 32 wherein said control means causes said needle to execute one cyclic movement for each threshold unit of movement measured by said detector. 34. The apparatus of claim 31 wherein said stack of fabric layers includes an exterior stack surface; and wherein said detector measures stack movement by measuring translational movement of said exterior stack surface. | RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application 60/447,159 filed 12 Feb. 2003. FIELD OF THE INVENTION This invention relates generally to a system for fastening together two or more flexible planar layers and more particularly to a method and apparatus for stitching together two or more fabric layers, as in quilting. BACKGROUND OF THE INVENTION Creating decorative quilts by hand has become a popular avocation. A typical quilt is comprised of at least two fabric layers which are stacked and stitched together. Generally the quilt is comprised of a “top” layer, a “bottom” or “backing” layer, and an intermediate “batting” layer. The top layer is typically decorative and is produced as a consequence of the creative and artistic effort of the quilt maker. The backing layer is usually simple and aesthetically compatible with the top. The batting layer generally provides bulk and insulation. The specific process of sewing the sandwich of the three planar layers together is generally referred to as “quilting”. The quilting process usually consists of forming long continuous patterns of stitches which extend through and secure the top, backing, and batting layers together. Oftentimes stitch patterns are selected which have a decorative quality to enhance the overall aesthetics. A general goal of the quilting process is to produce precise consistent stitches that are closely and uniformly spaced. Quilting traditionally has been performed by hand without the aid of a sewing machine. However, hand quilting is a labor-intensive process which can require many months of effort by a practiced person to create a single quilt. Accordingly, it appears that a trend is developing toward using machines to assist in the quilting process to allow most of the quilter's effort to be directed toward the creative and artistic aspects of the top layer. Machine quilting can be performed in a variety of ways. For example, a user can operate a substantially conventional sewing machine in a “free motion” mode by removing or disabling the machine's feed dogs. This allows the user to manually move the stacked quilt layers relative to the machine's needle, either directly or via a quilt frame, to produce desired patterns of stitches. In practice, the sewing machine is run at a relatively constant speed as the user moves the stacked quilt materials under the needle. This process typically requires significant operator skill acquired after much practice to enable the operator to move the quilt stack in synchronism with the needle stroke to form high quality stitch patterns. Thus, free motion quilting with a conventional sewing machine requires significant user skill and yet frequently yields imperfect results, particularly when forming curved and intricate stitch patterns. Machine quilting can also be performed by using a wide range of specialized hand guided quilting systems which have become available in recent years. The characteristics and features of such systems are discussed in an article which appeared in Quilter's Newsletter Magazine (QNM), April 2003, by Carol A. Thelen. The article identifies three categories of such systems; i.e., (1) Table top set-ups, (2) Shortarm systems, and (3) Longarm systems. They are generally characterized by a table which supports a frame and a quilting/sewing machine. The frame includes rollers which hold the quilt layers so as to enable a portion of the layered stack to be exposed for stitching while the remaining layer portions are stored on the rollers. The quilting/sewing machine rests on a carriage mounted for movement (e.g., along tracks) relative to the frame and table. The carriage is generally provided with handles enabling an operator to move the machine over the surface of the quilt. The QNM article further discusses optional add-ons and accessories enabling various electronic functions, including stitch regulation, to be added to basic shortarm or longarm systems. SUMMARY OF THE INVENTION The present invention is directed to a system for fastening together two or more flexible planar layers and more particularly to a quilting method and apparatus for enabling a user to readily produce uniform stitches for fastening together a stack of fabric layers. Apparatus in accordance with the invention permits a user to freely manually move a stack of planar layers across a planar bed, or plate, beneath an actuatable stitch head. The apparatus includes a detector for detecting the movement of the stack proximate to the stitch head for controlling actuation of the stitch head. Consequently, an apparatus in accordance with the invention functions to automatically synchronize the delivery of stitch strokes to the movement of the stack. This enables the user to move the stack within a wide range of speeds, to start or stop the stack movement at will, and to guide the stack in any direction across the planar bed. More particularly, a preferred apparatus in accordance with the invention includes a detector configured to detect stack movement within the throat space of a quilting/sewing machine by measuring the movement of at least one surface of the stack as it moves across the planar bed. Stack movement is preferably measured by determining translation of the stack along perpendicular X and Y directions. Preferred embodiments of the invention employ a detector capable of measuring stack surface movement without physically contacting the stack. A preferred detector in accordance with the invention responds to energy e.g., light, reflected from a surface of the stack as it moves across the planar bed. The detector preferably includes a detection window located to collect reflected energy from a target area coincident with the stack surface (top and/or bottom) within the machine's throat space. In a specific preferred embodiment, an optical detector is employed to provide output pulses representative of incremental translational movement of the stack along perpendicular X and Y directions. The output pulses are then counted to determine the distance the stack has moved. When the magnitude of movement exceeds a predetermined magnitude or threshold, a “stitch stroke” command is issued to cause the stitch head to insert a stitch through the stacked layers. As the user continues to freely move the stack across the planar bed, additional stitch stroke commands are successively issued to produce successive stitches synchronized with the user controlled stack motion. In accordance with one aspect of the preferred embodiment, the stitch head is configured to rapidly execute a single stitch cycle in response to each stitch stroke command. More particularly, the head is preferably configured so that its needle is held in its full up position between stitch cycles to avoid obstructing the user's freedom of movement for the stack. During each stitch cycle, a needle drive mechanism causes the needle to rapidly drop to pierce the stack layers on the bed, insert a stitch, and then rapidly rise back to its full up position to await the next stitch stroke command. Although a single stitch mode, or impulse mode, of operation is advantageous to enable a user to operate at slow stack speeds (preferably down to zero), at higher stack speeds, e.g., greater than 20 inches per minute, it is generally satisfactory to control the speed of a continuously running needle drive motor so as to be proportional to the speed of stack movement. In accordance with another aspect of a preferred embodiment, a stack hold-down plate or “presser foot” is associated with the stitch head. During a stitch cycle, the presser foot holds the stack against the bed to assure proper stitch tension and facilitate the needle's upward movement out of the stack. Between stitch cycles, the force on the presser foot is relieved to allow the stack to be freely moved through the machine's throat space between the presser foot and the planar bed. Although the preferred embodiments to be described herein comprise machines in which the elements of the invention are fully integrated, it is pointed out that alternative embodiments can adapt conventional sewing machines to operate in accordance with the present invention. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a block diagram of a quilting system in accordance with the invention for fastening stacked planar layers; FIG. 2 is a diagrammatic illustration of a first embodiment of the invention utilizing a motor/brake assembly to control the stitch head; FIGS. 3 and 4 are diagrammatic illustrations respectively showing the hold-down plate of FIG. 2 in its actuated and non-actuated positions; FIGS. 5 and 6 respectively show side and end views of an exemplary quilting/sewing machine housing; FIG. 7 is a diagrammatic illustration of a second embodiment of the invention, similar to FIG. 2, but utilizing a clutch/brake assembly to control the stitch head; FIG. 8 is a schematic illustration depicting a first optical motion detector embodiment for use in the systems of FIGS. 2 and 7; FIG. 9 is a schematic diagram of a control subsystem employing the detector of FIG. 8 for use in the embodiments of FIGS. 2 and 7; FIG. 10 is a flow chart depicting the operation of the controller of FIG. 9 in a single stitch, or impulse mode; FIG. 11 (presented as 11 (A) and 11 (B)) comprises a flow chart similar to FIG. 10 but depicting dual mode operation, i.e., (1) impulse mode and (2) proportional mode; FIG. 12 is a schematic illustration depicting a second alternative optical motion detector for use in the embodiments of FIGS. 2 and 7; FIG. 13 is a schematic diagram of a control subsystem employing the detector of FIG. 12 for use in the embodiments of FIGS. 2 and 7; FIG. 14 is a flow chart depicting the operation of the controller of FIG. 13; FIG. 15 is a diagrammatic illustration of a third alternative system embodiment; and FIG. 16 is a block diagram depicting how a conventional sewing machine can be adapted to incorporate the present invention. DETAILED DESCRIPTION Attention is initially directed to FIG. 1 which depicts a generalized system 10 in accordance with the invention for fastening together two or more flexible planar layers forming a stack 12. The stack 12 is supported for guided free motion along a reference X-Y plane 14 proximate to a fastening, or stitch, head 15. The head 15 is actuatable to insert a fastener, or stitch, through the stacked layers 12 to fasten the layers together. A motion detector 16 is provided to sense the movement of stack 12 across plane 14. Control circuitry 18 responds to increments of stack movement to actuate the head 15 to insert uniformly spaced fasteners or stitches through the layers of stack 12. As Will be described hereinafter, the detector 16 is preferably configured to measure the stack translational motion along perpendicular X, Y axes of reference plane 14 proximate to the stitch head 15. FIG. 2 illustrates a first preferred embodiment 20 of the system of FIG. 1 for stitching together fabric layers of a stack 22. The embodiment 20 is generally comprised of a mechanical machine portion 26, including an actuatable stitch head 28, and an electronic control subsystem 30 for actuating the head 28 in response to movement of the stack 22. Although the planar layers of stack 22 can consist of a wide variety of materials intended for different applications, the preferred embodiments to be discussed hereinafter are particularly configured for stitching together fabric layers, e.g., a top layer 32, an intermediate batting layer 34, and a bottom backing layer 36, to form a quilt. The machine portion 26 of FIG. 2 is generally comprised of a frame 40 configured to support the stitch head 28 above a bed 44 providing a substantially horizontally oriented planar surface 45. The stitch head 28 includes a needle bar 46 supporting a needle 48 for reciprocal vertical movement essentially perpendicular the planar surface 45. The bed surface 45 is configured for supporting the layered stack 22 so as to enable a user to freely manually guide the stack 22 across the surface 45. A hold-down plate, or presser foot, 50 is provided to selectively press the stack 22 against the bed surface, as will be explained hereinafter, to assure proper stitch tension and to assist the needle to pull upwardly out of the stack after inserting a stitch. A conventional hook and bobbin assembly 52 is mounted beneath the bed 44 in alignment with the needle 48. The stitch head 28 including needle bar 46 and needle 48, operates in a substantially conventional manner in conjunction with the hook and bobbin assembly 52 to insert a stitch through the stack 22 at a fixedly located opening, or stitch site, 54 on the bed. During a stitch cycle when the needle 48 is lowered to its down position to pierce the stack layers (FIG. 3), the hold-down plate 50 is also lowered to press the stack layers against the bed 44 to achieve proper stitch tension and assist the needle to pull up out of the stack. After completion of a stitch cycle, the needle 48 and hold-down plate 50 are raised (FIG. 4). As will be discussed hereinafter, the raised position of the hold-down plate (FIG. 4) is preferably selected to loosely bear against the stack to maintain the backing layer 36 (FIG. 2) against the bed 44 to assure detection by detector 16 while also permitting the stack to be freely moved across the bed 44. The preferred machine portion 26 of FIG. 2 is further depicted as including a motor/brake assembly 56 which functions to selectively provide operating power and braking via a suitable transmission system 58 to an upper drive shaft 60 and a lower drive shaft 62. The upper drive shaft 60 transfers power from the motor/brake assembly 56 to stitch head 28 for moving the needle 48. The lower drive shaft 62 transfers power from the motor/brake assembly 56 to the hook and bobbin assembly 52. The stitch head 28 and hook and bobbin assembly 52 operate cooperatively in a conventional manner to insert stitches through the layers of stack 22 at stitch site 54. That is, when the stitch head cycle is initiated, needle 48 is driven downwardly to pierce the stacked layers 32, 34, 36 and carry an upper thread (not shown) through the stitch site opening 54 in bed 44. Beneath the bed 44, the hook (not shown) of assembly 52 grabs a loop of the upper thread before the needle 48 pulls it back up through the stack which is held down by presser foot 50. The upper thread loop grabbed by the hook is then locked by, a thread pulled off the bobbin (not shown) of assembly 52. The system of FIG. 2 includes a transducer, or detector, 64 for detecting the movement, or more specifically, the translation of the stack 22 on bed 44 for controlling the motor/brake assembly 56 via control circuitry 65. As will be discussed in greater detail hereinafter, in operation, a user is able to freely move the layered stack 22 on bed 44 relative to the fixedly located stitch head 28 while the detector 64 produces electronic signals representative of the stack movement. Control circuitry 65 then responds to the detected stack movement for controlling the issuance of a stitch from head 28. The control subsystem 30, in addition to including motion detector 64 and control circuitry 65, also preferably includes a shaft position sensor 66. The shaft position sensor 66 functions to sense the particular rotational position of the upper drive shaft 60 corresponding to the needle 48 being in its full up position. As will be seen hereinafter, the control circuitry 65 responds to the output of sensor 66 to park the needle 48 in its full up position between successive stitch cycles. This action prevents the needle from interfering with the free translational movement of the stack 22 on bed 44. In accordance with the invention, an operator guides a fabric stack across the horizontally oriented bed 44 beneath the vertically oriented needle 48. The motion detector 64 in accordance with the invention is mounted to monitor a target area coincident with a surface layer (top and/or bottom) of the stack 22 as the stack is moved across the bed 44. As will be discussed hereinafter, the detector can be considered as having a window focused on the stack surface proximate to the needle penetration site. The detector can be variously physically mounted; e.g., above the stack looking down at the stack top surface or below the stack looking up at the stack bottom surface. Although the motion detector 64 of FIG. 2 can take many different forms, including both noncontacting devices (e.g., optical detector) and contacting devices (e.g., track ball), it is much preferred that it detect stack movement without physically contacting the fabric layers. Accordingly, a preferred motion detector in accordance with the invention comprises a device for responding to energy reflected from, or sourced by, the stack. Although this energy can be of several different forms (e.g., ultrasonic, RF, magnetic, electrostatic, etc.), the preferred detector embodiment employs an optical motion detector (represented in FIG. 8) utilizing, for example, an optical chip ADNS2051 marketed by Agilent Technologies. Alternative detectors for measuring stack can employ technologies such as accelerometers, resistive devices, etc. Suffice it to say at this point that the accurate measurement of stack movement depends, in part, upon the stack target layer, e.g., backing layer 36, being positioned near the focus of the motion detector window. The aforementioned hold-down plate or presser foot 50 assists in maintaining the stack layers at a certain distance from the detector window. In a preferred embodiment, the hold-down plate 50 has a flat smooth bottom surface 51 for engaging the stack 22 and is fabricated of transparent material to avoid obstructing a user's view of the stack layers proximate to the needle 48. FIGS. 3 and 4 respectively illustrate the actuated and non actuated positions of the hold-down plate 50. In FIG. 3, shaft 80 is moved down during the stitch cycle to cause the plate 50 to apply spring pressure, attributable to spring 82, to the stack 22. Between cycles (FIG. 4), shaft 80 is moved up so the pressure of plate 50 against stack 22 is relieved to reduce motion-inhibiting friction of the plate against the stack. Nevertheless, during a non-stitch interval between cycles, the plate 50 is positioned closely enough to loosely hold the stack against the bed 44. Note in FIGS. 3 and 4 that the hold-down plate 50 is attached to shaft 80 that slides, loaded by spring 82, up and down, relative to a presser foot arm 83. Also note that FIG. 4 shows the needle arm 46 assisting to pull the spring-loaded shaft 80 upwardly. The travel range of the hold-down plate 50 permits free horizontal motion of the quilt stack across the bed between stitch cycles but constrains vertical motion of the stack sufficiently to assure that the backing layer surface 36 is held against the bed surface and near the focus of the window of motion detector 64. FIGS. 5 and 6 schematically depict a typical quilting/sewing machine housing 84 for accommodating the physical components of the system of FIG. 2. The housing 84 comprises an upper arm 85 which contains the upper drive shaft 60 and a lower arm 86 containing the lower drive shaft 62. The housing upper and lower arms 85 and 86 extend from a vertically oriented machine arm 87. The upper and lower arms 85, 86 are vertically spaced from one another and together with the machine arm 87 define a space which is generally referred to as the throat space 88. The needle 48 descends vertically from the upper arm into the throat space 88 for reciprocal movement toward and away from the lower arm 85. The lower arm 85 carries the bed 44 which is sometimes referred to as the throat plate. The distance between the needle and the machine arm is generally referred to as the throat length. FIG. 8 depicts a preferred motion detector 64 comprising a housing 90 having a light collecting window 91. A light source, e.g., a light-emitting diode (LED) 92, is mounted in housing 90 and illuminates (via mirrors 93 and window 91) a target area coincident with the surface of backing layer 36 just above window 91. The light reflected from layer 36 is collected by a lens system 94 and is applied to the optical chip 95 (e.g., Agilent ADNS 2051). The chip 95 internally includes both a tiny CMOS array camera (not shown) which successively acquires images from the target area at about 1500 pictures per second and an associated digital signal processor or DSP (not shown). The signal processor operates at several million instructions per second to detect patterns in the acquired images and to determine, based on changes in a sequence of successive images, how those patterns have moved. As a consequence, the chip 95 is able to provide output pulses on lead 96 representative of incremental translation of the backing layer 36 portion coincident with the target area in an X direction and output pulses on lead 97 representative of incremental translation of the backing layer 36 in a Y direction. FIG. 7 illustrates a second alternative system embodiment 68 which contains a mechanical machine portion 26′ and an electronic control subsystem 30′, similar to the corresponding portions 26 and 30 of the embodiment of FIG. 2. However, the embodiment of FIG. 7 differs from FIG. 2 primarily in that it uses a clutch/brake assembly 69 to control power transfer from motor 70 to the stitch head 28′, in lieu of the aforementioned motor/brake assembly 56 of FIG. 2. Additionally, the hook and bobbin assembly 52′ in FIG. 7 is driven continuously by motor 70 with the position of the bobbin hook (not shown) therein being sensed by a hook position sensor 71. The outputs of stack motion detector 64′, shaft position sensor 66′, and hook position sensor 71 are all applied as inputs to control circuitry 65′ whose output controls the clutch/brake assembly 69 to selectively actuate the stitch head 28′. Attention is now directed to FIG. 9 which depicts a circuit diagram relevant to both the control subsystem 30 of FIGS. 2 and 30′ of FIG. 7. Note that FIG. 9 shows the optical motion detector 64 (64′) and the shaft position sensor 66 (66′) which are relevant to both FIGS. 2 and 7. Detector 64 (64′) and sensor 66 (66′) are connected to provide data signals to control circuitry 65 (65′) which is comprised primarily of a controller 98 (e.g., microcontroller chip Microchip PIC 12C508) and a timer circuit 99 (e.g., National 555). FIG. 9 also depicts in dashed line the hook position sensor 74 of FIG. 7 which provides a signal to timer 99 when the hook (not shown) reaches an active position. The shaft position sensor 66 (66′) and hook position sensor 74 preferably comprise devices which respond to optical stimuli respectively carried by shaft 60 and the hook of assembly 72, to produce signals for application to the control circuitry. Such optical stimuli would most typically comprise differentially reflective markers respectively placed on the upper drive shaft 60 and the hook of assembly 72. In operation, the microcontroller 98 functions to count output pulses provided by motion detector chip 95 on leads 96 and 97 which respectively represent increments of movement of the quilt backing layer 36 along orthogonal X and Y axes. When the microcontroller 98 recognizes a sufficient cumulative movement, it issues a signal to timer circuit 99. Alternatively, in the particular case of the clutch/brake embodiment of FIG. 7, the microcontroller signal is gated by the output of hook position sensor 74 so that it is applied to the timer circuit 99 only when the bobbin hook is in the desired position. The timer circuit 99 applies the stitch command signal on output 110 to load transistor 112. Transistor 112 controls relay 114 which is shown as operating a single pole double, throw switch 116. In the actuated, lower, position as depicted in FIG. 9, switch 116 applies power to drive the motor of motor/brake assembly 56 of FIG. 2 or alternatively, engages the clutch of clutch/brake assembly 69 of FIG. 7. The relay 114 is deactuated via the timer 98 and the transistor 112 by a pulse on line 102 from the shaft position sensor 66. In the deactuated, upper, position as depicted in FIG. 9, switch 116 closes a shunt path to thus brake the drive train. Attention is now directed to FIG. 10 which comprises a flow diagram depicting the algorithmic operation of microcontroller 98 for controlling the motor/brake assembly 56 of FIG. 2 or the clutch/brake assembly 69 of FIG. 7 to produce a single stitch. In FIG. 10, first note block 120 which functions to initialize a stitch cycle by acquiring a “stitch length” value which typically was previously entered via a user input. With the stitch length value set in block 120, the algorithm proceeds to decision block 122 which tests for stack translation in the X direction, i.e., for an X pulse on lead 96 from the optical chip 95. If a pulse is detected, then a store X count is incremented, as represented by block 124. After execution of blocks 122, 124, operation proceeds to decision block 126 which tests for Y translation, i.e., for a Y pulse on lead 97 of the optical motion chip 95. If a Y pulse is detected, then a stored Y count is incremented as represented by block 128. Operation then proceeds from blocks 126 or 128 to block 130. Blocks 130 and 132 essentially represent steps for determining the resultant stack movement magnitude attributable to the measured X and Y components of motion utilizing the Pythagorean theorem. That is, in block 130, the X count value is squared and the Y count value is squared. Block 132 sums the squared values calculated in block 130 to produce a value representative of the resultant stack movement. Block 134 compares the square of the preset switch length value with the magnitude derived from block 132. If the magnitude of the resultant movement is less than the preset stitch length, then operation cycles back via loop 136 to the initial block 120. If on the other hand, the resultant magnitude exceeds the preset stitch length, then operation proceeds to block 138 to initiate a stitch. In block 140, the X and Y counts are cleared before returning to the initial block 120. Additionally, after block 138, the relay (114 in FIG. 9) is energized by execution of block 142 to actuate the motor/brake assembly 56 (FIG. 2) or the clutch/brake assembly 69 (FIG. 7). Note, however, that termination of block 142 requires a terminating pulse from the shaft position sensor (represented by block 146) indicating that the upper drive shaft has reached the position to park the needle in its full up position. FIG. 10 also depicts a dashed block 148 between blocks 138 and 142. Block 148 is relevant to the embodiment of FIG. 7 and indicates that the execution of block 142 is deferred until receipt of an enabling signal from the hook position sensor 74 of FIG. 9. Whereas FIG. 10 depicts the algorithm for operation in the impulse, or single stitch, mode, FIG. 11 (presented as 11 (A) and 11 (B)) depicts dual mode operation, i.e., impulse mode at slow stack speeds and a continuous proportional mode at higher stack speeds. It is preferable to provide such a dual mode capability to be able to operate more smoothly at higher stack speeds. By way of explanation, it will be recalled that in order to accommodate slow stack speed operation, e.g., less than 20 inches per minute, it is desirable that each stitch command initiate a very rapid needle stroke to avoid the needle interfering with stack movement. As the stack translation speed and needle stroke rate increase, the needle's interference with stack movement diminishes. Thus, at fast stack speeds, e.g., greater than 20 inches per minute (or 200 stitches per minute assuring an exemplary 0.1 inch stitch length), it is appropriate to switch to a proportional mode in which the needle is continuously driven at a rate substantially proportional to stack speed. At a speed of 200 stitches per minute, each needle cycle consumes less than about 300 milliseconds. Accordingly, the algorithm depicted in FIG. 11(B) includes a step which tests for the time duration between successive stitch commands, i.e., a stitch time interval. If the duration of this interval is less than an exemplary 300 milliseconds, then operation proceeds in the proportional mode. An alternative embodiment of the invention (not shown) could operate solely in the proportional mode. Note that FIG. 11(A) is identical to FIG. 10 through the stitch command or “Initiate Stitch” block 138. FIG. 11(B) shows that block 138 is followed by block 152 which reads and resets a stitch interval timer (which can be readily implemented by a suitable microcontroller) which times the duration between successive stitch commands and records the angular position θn of the needle drive shaft 60 (block 153). Decision block 154 then tests the interval timer duration previously read in block 152 to determine whether it is greater than the aforementioned exemplary 300 millisecond interval. If yes, operation proceeds to the impulse mode 155. If no, operation proceeds to the proportional mode 156. Operation in the impulse mode 155 is essentially identical to the operation previously described with reference to FIG. 10 with regard to blocks 142, 146, 148. However, FIG. 11(B) additionally shows a block 157 in the impulse mode which can be executed to assure deactivation of the proportional mode and block 158 which deactuates a motor/clutch relay and actuates a brake after a stitch is delivered to park the needle in its up position. Operation in the proportional mode 156 includes step 159 which activates motor speed control operation. A motor speed control capability is a common feature of most modern sewing machines with motor speed being controlled by the user, e.g., via a foot pedal, and/or by built-in electronic control circuitry. After block 159, decision block 160 is executed. To understand the function of decision block 160, it must first be recognized that as stack speed is increased, thus generating shorter duration stitch intervals, the shaft angle position θn read in block 153 will decrease, in the absence of an adjustment of motor/needle shaft speed. In other words, a newly read shaft angle θn will be smaller than a previously read shaft angle θp. Block 160 functions to compare θn and θp if stack speed increases. If θn is smaller, the motor speed must be increased (block 161) to deliver stitches at an increased rate to maintain stitch length uniformity. On the other hand, if stack speed is reduced so that en is greater than θp, motor speed is decreased (block 162) in order to produce uniform length stitches. If stack speed remains constant, then θn equals θp and no motor sped adjustment is called for (block 163). From the foregoing, the operation of the systems of FIGS. 2 and 7 in accordance with the invention should be readily appreciated. By way of summary, it should be understood the system enables a user to freely translate the layered stack 22 over the bed 44. The detector 64 senses the movement of the stack to produce X and Y pulses representative of incremental translational movement with respect to orthogonal X and Y axes. The microcontroller 98 (FIG. 9) functions to count the X and Y pulses and determine when the resultant movement is at least equal to the preset stitch length. When this occurs, relay 114 is actuated to supply power via switch 116 to the motor/brake assembly 56 of FIG. 2 (or the clutch/brake assembly of FIG. 7) to initiate a single stitch stroke. That is, actuation of relay 114 throws switch 116 to its lower position (FIG. 9), thus causing the motor to spin Lip rapidly to transfer power to stitch head 28 and the hook and bobbin assembly 52. The upper and lower shafts 60, 62 rotate until the upper shaft marker passes under the shaft position sensor 66. When the shaft marker is detected, switch 116 is thrown to its upper position thus removing power to the motor/brake assembly 56 and shunting the assembly to quickly arrest the motion of, i.e., brake, the rapidly turning shafts. In order to assure free movement of the quilt stack, the shaft marker is placed so as to stop the needle in its full up position. To further assure free movement, the stitch stroke is caused to occur very rapidly so that the percentage of time the quilt layers are “trapped” by the needle and hold down plate 50 is very short. This can be accomplished by assuring that the motor/brake assembly uses an abundantly powered motor and a very rapid braking action, e.g., a DC motor employing an electric shunt for dynamic braking. Attention is now directed to FIG. 12 which illustrates an optical motion detector embodiment 175 which is alternative to the embodiment 64 shown in FIG. 8. It will be recalled that the embodiment of FIG. 8 operates by capturing a sequence of images and then comparing those images to detect motion of the quilt backing layer 36. The embodiment 175 of FIG. 12 operates instead to count threads (warp and/or woof) as they cross the focal point of a light beam. With continuing reference to FIG. 12, note that the detector embodiment 175 is comprised of a housing 176 preferably mounted beneath the bed 144. The housing contains a light source 178 which transmits light through lens system 180 to produce a beam focused against the backing layer 36 of the quilt material stack 22. The reflected light from the backing layer is collected by lens system 182 and coupled to a photodetector 184. The photodetector 184 generates a detectable signal change for each thread crossing the focal point of the beam incident on the backing layer 36. The output of photodetector 184 drives an amplifier 186 to produce a pulse output 188 representing thread crossings, i.e., backing layer motion. Attention is now directed to FIG. 13 which illustrates a circuit diagram of a control subsystem substantially identical to that shown in FIG. 9 except that it incorporates the optical motion detector 175 of FIG. 12 in lieu of the optical motion detector 64 of FIG. 8. More particularly, note that FIG. 13 shows light source 178 illuminating photodetector 184 which drives amplifier 186 to produce output pulses on lead 188. Lead 188 is connected to the input of the aforediscussed microcontroller 96. Attention is now directed to FIG. 14 which illustrates a flow diagram depicting the algorithmic operation of the microcontroller 96 of FIG. 13 when used in conjunction with the optical motion detector 175. A stitch cycle in accordance with FIG. 14 starts with block 200 which functions to acquire a “stitch length” value. Operation proceeds from block 200 to decision block 202 which looks for a pulse on lead 188 (FIG. 13) from the optical detector 175. If no pulse is detected, operation proceeds directly to decision block 206. If a pulse is detected, operation proceeds to block 204 which increments a stored thread count, prior to proceeding to decision block 206. Block 206 compares the preset stitch length value with the current thread count. If the preset stitch length is greater than the current thread count, then operation loops back to the initial block 200. On the other hand, if the stitch length is equal to or less than the current thread count, then operation proceeds to block 208 to initiate a stitch. In block 210, the current thread count is cleared or reset to zero and operation loops back to the initial block 200. Additionally, after execution of block 210, the output relay 114 is energized in block 212 to actuate the motor/brake assembly 56 or clutch/brake assembly 69. However, as will recalled from the flow diagram of FIG. 10, the termination of block 212 requires a terminating signal from the shaft position sensor 66 (represented by block 214) to indicate that the needle is in its full up position. FIG. 14 also depicts dashed block 216 between blocks 210 and 212. Block 216 is relevant to the embodiment of FIG. 7 and indicates that the execution of block 212 is deferred until receipt of an enabling signal from the hook position sensor 74 shown in FIG. 13. It is pointed out that FIG. 14 only demonstrates operation in a single stitch, or impulse, mode but it should be understood that alternative embodiments can function solely in a continuous proportional mode or in a dual mode system by incorporating the steps depicted in FIG. 11(B). Embodiments of the invention can be configured to produce a wide range of uniform stitch lengths. For typical quilting applications, a stitch length of about 2.5 mm ({fraction (1/10)} in.) is considered attractive by a significant segment of the quilting community. In typical use by an exemplary user, it is expected that the stack would be moved on the order of one inch per second which would equate to ten stitches per inch or ten stitches per second (i.e., 100 milliseconds per stitch). In this exemplary situation, if the stitch cycle duration is limited to 50 milliseconds or less, the needle 48 and hold-down plate 50 would capture the stack less than 50% of the time thus providing the user with a sensation of free stack movement. Although only a limited number of specific embodiments have been described herein, it should be recognized that many further alternative arrangements will occur to those skilled in the art which fall within the spirit of the invention and the intended scope of the appended claims. For example only, FIG. 15 illustrates a third exemplary embodiment 220 alternative to the embodiments of FIGS. 2 and 7. The embodiment 220 differs primarily in that instead of using a common drive train, embodiment 220 uses separate electric actuators 224, 226 for respectively driving the stitch head and hook and bobbin assembly. The actuators 224 and 226 are controlled by control circuitry 228 in response to signals supplied by motion detector 230 representative of stack movement. Although the preferred embodiments described herein comprise machines in which the elements of the invention are fully integrated, it is recognized that an alternative embodiment can be provided for after market adapting of a conventional sewing machine to operate in accordance with the invention. More particularly, attention is directed to FIG. 16 which depicts a conventional sewing machine 250 having a drive motor 252. The drive motor is typically controlled by motor control circuitry 254 which can control motor speed and other aspects or motor operation. Motor speed is typically controlled by a user input provided by a foot control 256 via a cable 258 and plug 260 which mates with a connector 262. A stitch control module 264 in accordance with the present invention is intended to be plugged into connector 262 in place of original foot control 256 to operate the needle at a rate proportional to movement of a fabric stack. The module 264 is comprised of a motion detector 266, as previously discussed, mounted to measure stack movement within the throat space of machine 250. The detector 266 is connected to control circuitry 268 which drives a foot control adapter 270. The adapter 270 is configured to accept speed control input commands from control circuitry 268 and, in turn, output commands, i.e., control signals which simulate those provided by the original foot control 256. The adapter output control signals are coupled via cable 272 to plug 274 for mating with connector 262. Inasmuch as different machines may have different interfaces for coupling the original foot control 256 to the connector 262 and motor control circuit 254, the foot control adapter 270 and plug 274 should be configured to be compatible with the particular sewing machine being adapted. From the foregoing, it should be understood that the described quilting/sewing apparatus enables a user to manually grasp a fabric layer stack to move it across a planar bed to produce uniform length stitches through the stack. It should be understood that the user could alternatively choose to mount the stack on a simple commercially available frame enabling the user to grasp the frame in order to move the stack across the bed. It is also pointed out that the quilting/sewing machine described herein can be used in a hand guided quilting system having a frame for holding the fabric stack and a moveable carriage for supporting the quilting/sewing machine. | <SOH> BACKGROUND OF THE INVENTION <EOH>Creating decorative quilts by hand has become a popular avocation. A typical quilt is comprised of at least two fabric layers which are stacked and stitched together. Generally the quilt is comprised of a “top” layer, a “bottom” or “backing” layer, and an intermediate “batting” layer. The top layer is typically decorative and is produced as a consequence of the creative and artistic effort of the quilt maker. The backing layer is usually simple and aesthetically compatible with the top. The batting layer generally provides bulk and insulation. The specific process of sewing the sandwich of the three planar layers together is generally referred to as “quilting”. The quilting process usually consists of forming long continuous patterns of stitches which extend through and secure the top, backing, and batting layers together. Oftentimes stitch patterns are selected which have a decorative quality to enhance the overall aesthetics. A general goal of the quilting process is to produce precise consistent stitches that are closely and uniformly spaced. Quilting traditionally has been performed by hand without the aid of a sewing machine. However, hand quilting is a labor-intensive process which can require many months of effort by a practiced person to create a single quilt. Accordingly, it appears that a trend is developing toward using machines to assist in the quilting process to allow most of the quilter's effort to be directed toward the creative and artistic aspects of the top layer. Machine quilting can be performed in a variety of ways. For example, a user can operate a substantially conventional sewing machine in a “free motion” mode by removing or disabling the machine's feed dogs. This allows the user to manually move the stacked quilt layers relative to the machine's needle, either directly or via a quilt frame, to produce desired patterns of stitches. In practice, the sewing machine is run at a relatively constant speed as the user moves the stacked quilt materials under the needle. This process typically requires significant operator skill acquired after much practice to enable the operator to move the quilt stack in synchronism with the needle stroke to form high quality stitch patterns. Thus, free motion quilting with a conventional sewing machine requires significant user skill and yet frequently yields imperfect results, particularly when forming curved and intricate stitch patterns. Machine quilting can also be performed by using a wide range of specialized hand guided quilting systems which have become available in recent years. The characteristics and features of such systems are discussed in an article which appeared in Quilter's Newsletter Magazine (QNM), April 2003, by Carol A. Thelen. The article identifies three categories of such systems; i.e., (1) Table top set-ups, (2) Shortarm systems, and (3) Longarm systems. They are generally characterized by a table which supports a frame and a quilting/sewing machine. The frame includes rollers which hold the quilt layers so as to enable a portion of the layered stack to be exposed for stitching while the remaining layer portions are stored on the rollers. The quilting/sewing machine rests on a carriage mounted for movement (e.g., along tracks) relative to the frame and table. The carriage is generally provided with handles enabling an operator to move the machine over the surface of the quilt. The QNM article further discusses optional add-ons and accessories enabling various electronic functions, including stitch regulation, to be added to basic shortarm or longarm systems. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is directed to a system for fastening together two or more flexible planar layers and more particularly to a quilting method and apparatus for enabling a user to readily produce uniform stitches for fastening together a stack of fabric layers. Apparatus in accordance with the invention permits a user to freely manually move a stack of planar layers across a planar bed, or plate, beneath an actuatable stitch head. The apparatus includes a detector for detecting the movement of the stack proximate to the stitch head for controlling actuation of the stitch head. Consequently, an apparatus in accordance with the invention functions to automatically synchronize the delivery of stitch strokes to the movement of the stack. This enables the user to move the stack within a wide range of speeds, to start or stop the stack movement at will, and to guide the stack in any direction across the planar bed. More particularly, a preferred apparatus in accordance with the invention includes a detector configured to detect stack movement within the throat space of a quilting/sewing machine by measuring the movement of at least one surface of the stack as it moves across the planar bed. Stack movement is preferably measured by determining translation of the stack along perpendicular X and Y directions. Preferred embodiments of the invention employ a detector capable of measuring stack surface movement without physically contacting the stack. A preferred detector in accordance with the invention responds to energy e.g., light, reflected from a surface of the stack as it moves across the planar bed. The detector preferably includes a detection window located to collect reflected energy from a target area coincident with the stack surface (top and/or bottom) within the machine's throat space. In a specific preferred embodiment, an optical detector is employed to provide output pulses representative of incremental translational movement of the stack along perpendicular X and Y directions. The output pulses are then counted to determine the distance the stack has moved. When the magnitude of movement exceeds a predetermined magnitude or threshold, a “stitch stroke” command is issued to cause the stitch head to insert a stitch through the stacked layers. As the user continues to freely move the stack across the planar bed, additional stitch stroke commands are successively issued to produce successive stitches synchronized with the user controlled stack motion. In accordance with one aspect of the preferred embodiment, the stitch head is configured to rapidly execute a single stitch cycle in response to each stitch stroke command. More particularly, the head is preferably configured so that its needle is held in its full up position between stitch cycles to avoid obstructing the user's freedom of movement for the stack. During each stitch cycle, a needle drive mechanism causes the needle to rapidly drop to pierce the stack layers on the bed, insert a stitch, and then rapidly rise back to its full up position to await the next stitch stroke command. Although a single stitch mode, or impulse mode, of operation is advantageous to enable a user to operate at slow stack speeds (preferably down to zero), at higher stack speeds, e.g., greater than 20 inches per minute, it is generally satisfactory to control the speed of a continuously running needle drive motor so as to be proportional to the speed of stack movement. In accordance with another aspect of a preferred embodiment, a stack hold-down plate or “presser foot” is associated with the stitch head. During a stitch cycle, the presser foot holds the stack against the bed to assure proper stitch tension and facilitate the needle's upward movement out of the stack. Between stitch cycles, the force on the presser foot is relieved to allow the stack to be freely moved through the machine's throat space between the presser foot and the planar bed. Although the preferred embodiments to be described herein comprise machines in which the elements of the invention are fully integrated, it is pointed out that alternative embodiments can adapt conventional sewing machines to operate in accordance with the present invention. | 20040211 | 20050426 | 20050127 | 96880.0 | 2 | KAUFFMAN, BRIAN K | QUILTING METHOD AND APPARATUS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,776,376 | ACCEPTED | Polyurethaneurea resins with trialkoxysilane groups and processes for the production thereof | Polyurethaneurea resins containing at least one group of the formula (I) —NH(CO)XOR1O(CO)CHR2CH2N[CnH2nSi(OR3)3](CO)NH— (I) and/or at least one group of the formula (II) {—NH(CO)XO}a{CH2═CR2(CO)O}bR4{O(CO)CHR2CH2N[CnH2nSi(OR3)3](CO)NH—}c (II) wherein X=[O(CH2)4]q(OC2H4)x(OC3H6)y[(CH2)5(CO)]z; q=0 to 10; x=0 to 20; y=0 to 20; z=0 to 10; n=2 or 3; a=1 or 2; b=0 to 4; c=1 to 5; R1=—C2H4—, —C3H6—, —C4H8—, —CH(CH2O(CO)R5)CH2— or —CH2CH(O(CO)R5)CH2—; R2=H or CH3; R3=C1 to C4 alkyl; R4=a+b+c-valent, saturated hydrocarbon residue of a (cyclo)alkane polyol with a+b+c hydroxyl groups; R5=an acid residue of a monocarboxylic acid, with the proviso that a+b+c=3 to 6 and wherein the sequence of the subformulae indicated q, x, y and z may be varied at will and q, x, y and z in each case merely state the number of instances of the particular subformulae contained in the formulae (I) and (II). | 1. Polyurethaneurea resins comprising at least one group of the formula (I) —NH(CO)XOR1O(CO)CHR2CH2N[CnH2nSi(OR3)3](CO)NH— (I) or at least one group of the formula (II) {—NH(CO)XO}a{CH2═CR2(CO)O}bR4{O(CO)CHR2CH2N[CnH2nSi(OR3)3](CO)NH—}c (II) or any mixtures of (I) and (II); wherein X=[O(CH2)4]q(OC2H4)x(OC3H6)y[O(CH2)5(CO)]z; q=0 to 10; x=0 to 20; y=0 to 20; z=0 to 10; n=2 or 3; a=1 or 2; b=0 to 4; c=1 to 5; R1=—C2H4—, —C3H6—, —C4H8—, —CH(CH2O(CO)R5)CH2— or —CH2CH(O(CO)R5)CH2—; R2=H or CH3; R3=C1 to C4 alkyl; R4=a+b+c-valent, saturated hydrocarbon residue of a (cyclo)alkane polyol with a+b+c hydroxyl groups; R5=an acid residue of a monocarboxylic acid, with the proviso that a+b+c=3 to 6 and wherein the sequence of the subformulae indicated q, x, y and z may be varied at will and q, x, y and z in each case merely state the number of instances of the particular subformulae contained in the formulae (I) and (II). 2. The polyurethaneurea resins of claim 1, wherein groups (I) or (II) or (I) and (II) are present in an amount corresponding to a silicon content of 1.4 to 5 wt. %. 3. The polyurethaneurea resins of claim 1, wherein the polyurethaneurea resins contain at least one further functional group in addition to groups (I) and/or (II). 4. The polyurethaneurea resins of claim 3, wherein the at least one further functional group is selected from the group consisting of isocyanate groups, carboxyl groups, (meth)acryloyl groups, hydroxyl groups and trialkoxysilane functions which are present other than as a constituent of groups (I) or (II). 5. A process for the production of the polyurethaneurea resins of claim 1 comprising the successive steps: a) reaction of an aminoalkyltrialkoxysilane comprising a primary amino group with at least one compound selected from the group consisting of compounds of the formula (III) HXOR1O(CO)CR2═CH2 (III) and compounds of the formula (IV) {HXO}aR4{O(CO)CR2═CH2}b+c (IV), wherein X=[O(CH2)4]q(OC2H4)x(OC3H6)y[O(CH2)5(CO)]z; q=0 to 10; x=0 to 20; y=0 to 20; z=0 to 10; n=2 to 3; a=1 or 2; b=0 to 4; c=1 to 5; R1=—C2H4—, —C3H6—, —C4H8—, —CH(CH2O(CO)R5)CH2— or —CH2CH(O(CO)R5)CH2—; R2=H or CH3; R3=C1 to C4 alkyl; R4=a+b+c-valent, saturated hydrocarbon residue of a (cyclo)alkane polyol with a+b+c hydroxyl groups; R5=acid residue of a monocarboxylic acid, with the proviso that a+b+c=3 to 6 and wherein the sequence of the subformulae indicated q, x, y and z may be varied at will and q, x, y and z in each case merely state the number of instances of the particular subformulae contained in the formulae (III) and (IV), to form at least one simultaneously hydroxy-, secondary amino- and trialkoxysilane-functional preadduct, b) reaction of the at least one preadduct formed in step a) with an isocyanate component selected from the group consisting of polyisocyanate, isocyanate-functional polyurethane prepolymer, isocyanate-functional polyurethaneurea prepolymer and combinations thereof with consumption of the hydroxyl and secondary amino groups of the at least one preadduct. 6. A process for the production of the polyurethaneurea resins of claim 1 comprising the successive steps: a) reaction of an isocyanate component selected from the group consisting of polyisocyanate, isocyanate-functional polyurethane prepolymer, isocyanate-functional polyurethaneurea prepolymer and combinations thereof with at least one compound selected from the group consisting of compounds of the formula (III) HXOR1O(CO)CR2═CH2 (III) and compounds of the formula (IV) {HXO}aR4{O(CO)CR2═CH2}b+c (IV), wherein X=[O(CH2)4]q(OC2H4)x(OC3H6)y[O(CH2)5(CO)]z; q=0 to 10; x=0 to 20; y=0 to 20; z=0 to 10; n=2 or 3; a=1 or 2; b=0 to 4; c=1 to 5; R1=—C2H4—, —C3H6—, —C4H8—, —CH(CH2O(CO)R5)CH2— or —CH2CH(O(CO)R5)CH2—; R2═H or CH3; R3=C1 to C4 alkyl; R4=a+b+c-valent, saturated hydrocarbon residue of a (cyclo)alkane polyol with a+b+c hydroxyl groups; R5=acid residue of a monocarboxylic acid, with the proviso that a+b+c=3 to 6 and wherein the sequence of the subformulae indicated q, x, y and z may be varied at will and q, x, y and z in each case merely state the number of instances of the particular subformulae contained in the formulae (III) and (IV) with consumption of the isocyanate groups, b) addition of aminoalkyltrialkoxysilane with the nucleophilic primary amino group onto (meth)acryloyl groups of the reaction product obtained in step a) with complete consumption of the primary amino groups and conversion into secondary amino groups, c) reaction of the reaction product obtained in step b) with a further isocyanate component selected from the group consisting of polyisocyanate, isocyanate-functional polyurethane prepolymer, isocyanate-functional polyurethaneurea prepolymer and combinations thereof with formation of urea bridges. 7. Compositions containing at least one polyurethaneurea resin of claim 1. 8. The compositions of claim 7 selected from the group consisting of adhesives, sealants and coating compositions. | FIELD OF THE INVENTION The present invention relates to novel polyurethaneurea resins with trialkoxysilane groups and to processes for the production thereof. BACKGROUND OF THE INVENTION Polyurethaneurea resins with trialkoxysilane groups and methods for the production thereof are known per se. For example, isocyanate-functional polyurethane prepolymers and/or isocyanate-functional polyurethaneurea prepolymers may be reacted with trialkoxysilanes carrying primary or secondary amino groups to yield polyurethaneurea resins with terminal trialkoxysilane groups. Such polyurethaneurea resins with trialkoxysilane groups are described, for example, in U.S. Pat. No. 5,760,123 as starting products for the production of aqueous dispersions of polyurethaneurea resins with siloxane bridges. Alternatively, functionalized polyurethaneurea resins may be reacted in a polymer-analogous reaction with suitably functionalized trialkoxysilanes, i.e., trialkoxysilanes which comprise groups which are complementarily reactive towards the functional groups of the polyurethaneurea resins, to yield polyurethaneurea resins with trialkoxysilane groups. SUMMARY OF THE INVENTION The present invention provides novel polyurethaneurea resins with trialkoxysilane groups, which differ from hitherto known polyurethaneurea resins with trialkoxysilane groups with regard to the chemical incorporation of the trialkoxysilane groups in the polyurethaneurea resin and thus extend the range of polyurethaneurea resins with trialkoxysilane groups. The invention furthermore provides processes for the production of polyurethaneurea resins, which processes, when required, also permit the polyurethaneurea resins to be provided with a comparatively elevated content of trialkoxysilane groups. When required, the processes also provide an elegant pathway to providing the polyurethaneurea resins with additional functional groups in addition to the trialkoxysilane groups incorporated in the novel manner. The invention relates to polyurethaneurea resins with trialkoxysilane groups, wherein the polyurethaneurea resins contain at least one group of the formula (I) —NH(CO)XOR1O(CO)CHR2CH2N[CnH2nSi(OR3)3](CO)NH— (I) and/or at least one group of the formula (II) {—NH(CO)XO}a{CH2═CR2(CO)O}bR4{O(CO)CHR2CH2N[CnH2nSi(OR3)3](CO)NH—}c (II) wherein X=[O(CH2)4]q(OC2H4)x(OC3H6)y[O(CH2)5(CO)]z; q=0 to 10, preferably 0; x=0 to 20, preferably 0; y=0 to 20, preferably 0; z=0 to 10, preferably 0; n=2 or 3; a=1 or 2; b=0 to 4, in particular 0; c=1 to 5; R1=—C2H4—, —C3H6—, —C4H8—, —CH(CH2O(CO)R5)CH2— or —CH2CH(O(CO)R5)CH2—, preferably —C2H4—, —C3H6— or —C4H8—; R2═H or CH3, preferably H; R3=C1 to C4 alkyl; R4=a+b+c-valent, saturated hydrocarbon residue of a (cyclo)alkane polyol with a+b+c hydroxyl groups; R5=an acid residue of a monocarboxylic acid, with the proviso that a+b+c=3 to 6 and wherein the sequence of the subformulae indicated q, x, y and z may be varied at will and q, x, y and z in each case merely state the number of instances of the particular subformulae contained in the formulae (I) and (II). DETAILED DESCRIPTION OF THE EMBODIMENTS Groups (I) and (II) respectively of the polyurethaneurea resins according to the invention are formally derived from the addition of isocyanate groups of polyisocyanate and/or isocyanate-functional polyurethane prepolymer and/or isocyanate-functional polyurethaneurea prepolymer onto hydroxyl and secondary amino groups of addition products formed by the reaction of primary amino group and (meth)acryloyl group, preferably acryloyl group, from aminoalkyltrialkoxysilane with a primary amino group and compounds of the formula (III) HXOR1O(CO)CR2═CH2 (III) and of the formula (IV) respectively {HXO}aR4{O(CO)CR2═CH2}b+c (IV), wherein X=[O(CH2)4]q(OC2H4)x(OC3H6)y[O(CH2)5(CO)]z; q=0 to 10, preferably 0; x=0 to 20, preferably 0; y=0 to 20, preferably 0; z=0 to 10, preferably 0; n=2 or 3; a=1 or 2; b=0 to 4, in particular 0; c=1 to 5; R1=—C2H4—, —C3H6—, —C4H8—, —CH(CH2O(CO)R5)CH2— or —CH2CH(O(CO)R5)CH2—, preferably —C2H4—, —C3H6—, or —C4H8—; R2=H or CH3, preferably H; R3=C1 to C4 alkyl; R4=a+b+c-valent, saturated hydrocarbon residue of a (cyclo)alkane polyol with a+b+c hydroxyl groups; R5=an acid residue of a monocarboxylic acid with the proviso that a+b+c=3 to 6 and wherein the sequence of the subformulae indicated q, x, y and z may be varied at will and q, x, y and z in each case merely state the number of instances of the particular subformulae contained in the formulae (III) and (IV). The term “(meth)acryloyl” used in the present description and in the claims means “methacryloyl” or “acryloyl”, preferably “acryloyl”. The groups (I) and (II) have CONH groups on both or on their a+c termini, via the NH nitrogen atoms of which they are incorporated into the polyurethaneurea resins. The trialkoxysilane functions of groups (I) and (II) respectively are thus present as non-terminal groups in the polyurethaneurea resins. The nitrogen substituted with the [CnH2nSi(OR3)3] group in groups (I) and (II) respectively is tertiary and carries no hydrogen. It is assumed that this is the cause of the relatively slight tendency of the polyurethaneurea resins according to the invention to form hydrogen bridges, which, for example, makes it possible to obtain a low solution viscosity of organic solutions of the polyurethaneurea resins according to the invention or compositions formulated therewith. The polyurethaneurea resins according to the invention contain groups (I) and/or (II) in an amount corresponding to a silicon content of, for example, 1.4 to 5 wt. %. The polyurethaneurea resins according to the invention may contain the trialkoxysilane functions of groups (I) and/or (II) as the only functional groups. They may, however, also comprise one or more further functional groups, provided that the latter are compatible with the trialkoxysilane functions of groups (I) and (II) respectively and with one another, for example, isocyanate groups, carboxyl groups, (meth)acryloyl groups, hydroxyl groups or trialkoxysilane functions which are present other than as a constituent of groups (I) or (II). The invention also relates to processes for the production of the polyurethaneurea resins according to the invention. A first process for the production of the polyurethaneurea resins according to the invention consists in initially producing, in a first step, synthesis building blocks which are suitable for introducing groups (I) and/or (II) into the polyurethaneurea resins and simultaneously carry hydroxyl, secondary amino and trialkoxysilane functions. This proceeds by addition with the nucleophilic primary amino group of an aminoalkyltrialkoxysilane comprising a primary amino group onto the (meth)acryloyl group, preferably acryloyl group, of at least one compound (III) and/or onto the only one or one or more of the (meth)acryloyl group(s), preferably acryloyl group(s), of at least one compound (IV) with the formation of at least one correspondingly functionalized preadduct. In the following step, the previously formed preadduct(s) and optionally additional compounds (A) capable of addition onto isocyanate groups are reacted with an isocyanate component consisting of polyisocyanate and/or isocyanate-functional polyurethane prepolymer and/or isocyanate-functional polyurethaneurea prepolymer with consumption of hydroxyl and secondary amino groups of the preadduct(s) and formation of a polyurethaneurea resin with groups (I) and/or (II). The reaction of the preadducts with the isocyanate component may proceed in a single- or multi-stage synthesis sequence. For example, all starting materials may be reacted together simultaneously or a multistage method is used, for example, by adding different starting materials in succession and/or by adding identical starting materials successively in portions with a time delay. In a second, preferred process for the production of the polyurethaneurea resins according to the invention, an isocyanate component consisting of polyisocyanate and/or isocyanate-functional polyurethane prepolymer and/or isocyanate-functional polyurethaneurea prepolymer is reacted in a first synthesis step comprising one or more stages with at least one compound (III) and/or at least one compound (IV) and optionally further compounds (A) capable of addition onto isocyanate groups with consumption of the isocyanate groups. Then, in a second synthesis step, aminoalkyltrialkoxysilane with the nucleophilic primary amino group is added onto the (meth)acryloyl groups, preferably acryloyl groups, of the reaction product obtained in the first synthesis step, said (meth)acryloyl groups originating from compounds (III) and/or (IV). While the primary amino groups are here completely consumed and converted into secondary amino groups, any (meth)acryloyl groups optionally present in excess may be retained. In a third synthesis step, the reaction product obtained in the second synthesis step is then reacted with a further isocyanate component consisting of polyisocyanate and/or isocyanate-functional polyurethane prepolymer and/or isocyanate-functional polyurethaneurea prepolymer and optionally with further compounds (A) capable of addition onto isocyanate groups. In this last synthesis step, the secondary amino groups formed in the preceding synthesis step react with isocyanate groups to form urea bridges, so simultaneously forming groups (I) and/or (II). The processes for the production of the polyurethaneurea resins according to the invention may be performed in such a manner that polyurethaneurea resins are obtained which contain no further functional groups other than the trialkoxysilane functions of groups (I) and/or (II). They may, however, also be performed in such a manner that the polyurethaneurea resins comprise one or more further types of functional groups, but only provided that the latter are compatible with the trialkoxysilane functions of groups (I) and (II) respectively and with one another, for example, isocyanate groups, (meth)acryloyl groups, carboxyl groups, hydroxyl groups or trialkoxysilane groups which are present other than as a constituent of groups (I) or (II). Isocyanate groups may, for example, originate from polyisocyanate and/or isocyanate-functional polyurethane prepolymer and/or isocyanate-functional polyurethaneurea prepolymer introduced into the synthesis in stoichiometric excess. (Meth)acryloyl groups may, for example, originate from compounds' (IV) (meth)acryloyl groups, the latter having been in stoichiometric excess with regard to the reaction with aminoalkyltrialkoxysilane, or they may be introduced via suitable compounds (A). Carboxyl groups may, for example, originate from isocyanate-functional polyurethane prepolymer and/or isocyanate-functional polyurethaneurea prepolymer or be introduced via suitable compounds (A). Hydroxyl groups may, for example, originate from polyol and/or aminoalcohol used as compounds (A) in stoichiometric excess with regard to the reaction with isocyanate. Examples of polyisocyanates usable in the processes for the production of the polyurethaneurea resins according to the invention are the conventional, in particular commercially available di- or triisocyanates, such as 1,6-hexane diisocyanate, isophorone diisocyanate, biscyclohexylmethane diisocyanate, cyclohexane diisocyanate, tetramethylxylylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, or conventional commercially available polyisocyanates derived therefrom, for example, polyisocyanates of the biuret, uretidione or isocyanurate type. Isocyanate-functional polyurethane prepolymers may be used as isocyanate-functional starting materials for the production of the polyurethaneurea resins according to the invention. Isocyanate-functional polyurethane prepolymers are known to the person skilled in the art and may be produced in conventional manner by reaction of polyisocyanates, for example, the polyisocyanates listed above, with low molecular weight, oligomeric and/or polymeric polyhydroxy-functional compounds. Examples of polyhydroxy-functional compounds are low molecular weight diols, such as ethylene glycol, the isomeric propane- and butanediols, neopentyl glycol, butylethylpropanediol, 1,6-hexanediol, cyclohexanediol, cyclohexanedimethanol; low molecular weight triols, such as trimethylolethane, trimethylolpropane, glycerol; low molecular weight polyols with more than three hydroxyl groups, such as pentaerythritol, sorbitol, dipentaerythritol; oligomeric or polymeric polyols with number average molar masses Mn of, for example, 500 to 3000 and hydroxyl values of, for example, 50 to 500 mg of KOH/g, for example, corresponding polyester polyols, polycarbonate polyols, polycaproplactone polyols, polyether polyols, hydroxy-functional (meth)acrylic copolymers. Apart from the hydroxyl groups, the polyhydroxy-functional compounds may also comprise further, functional groups which are inert towards isocyanate groups, for example, carboxyl groups, (meth)acryloyl groups. Examples of polyhydroxy-functional compounds which also contain carboxyl groups are dimethylolpropionic acid, dimethylolbutyric acid, tartaric acid, polyester polyols containing carboxyl groups, simultaneously hydroxy- as well as carboxy-functional (meth)acrylic copolymers. Examples of polyhydroxy-functional compounds which also contain (meth)acryloyl groups are glycerol mono(meth)acrylate, trimethylolpropane mono(meth)acrylate. Isocyanate-functional polyurethaneurea prepolymers may be used as isocyanate-functional starting materials for the production of the polyurethaneurea resins according to the invention. Isocyanate-functional polyurethaneurea prepolymers are known to the person skilled in the art and may be produced in conventional manner by reacting polyisocyanates, for example, the polyisocyanates listed above, with low molecular weight, oligomeric and/or polymeric compounds, which provide hydroxyl groups and primary or secondary amino groups for the reaction with the isocyanate groups. The compounds which provide the hydroxyl groups and primary or secondary amino groups for the reaction with the isocyanate groups may comprise aminoalcohols and combinations of polyols and polyamines, polyols and aminoalcohols, polyamines and aminoalcohols or of polyols, polyamines and aminoalcohols. Examples of polyols may be found among the polyhydroxy-functional compounds stated in the paragraph above. The aminoalcohols comprise aminoalcohols with at least one amino group capable of addition with isocyanate groups, such as, for example, ethanolamine, diethanolamine, isopropanolamine or methylethanolamine. The polyamines comprise polyamines with at least two amino groups capable of addition with isocyanate groups, such as, for example, ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine. Examples of aminoalkyltrialkoxysilanes with a primary amino group usable in the production of the polyurethaneurea resins according to the invention are aminoethyl- and aminopropyltrialkoxysilanes with C1 to C4 alkoxy residues attached to silicon. Preferred examples are the corresponding trimethoxy- and triethoxysilane compounds, in particular the trimethoxysilane compounds. The monohydroxy compounds (III) usable in the production of the polyurethaneurea resins according to the invention preferably comprise compounds which do not contain a group X. Examples of preferred monohydroxy compounds of the formula (III) are in particular hydroxyethyl(meth)acrylate, the isomeric hydroxypropyl- and hydroxybutyl(meth)acrylates, but also adducts formed by addition of glycidyl(meth)acrylate onto monocarboxylic acid R5COOH, such as acetic acid or propionic acid, or by addition of (meth)acrylic acid onto glycidyl esters of a monocarboxylic acid R5COOH, in particular onto glycidyl esters of highly branched monocarboxylic acids such as, for example, Cardura® E (from Resolution Performance Products, Hoogvliet, Netherlands). As defined above in the formula (III), the monohydroxy compounds (III) may contain a group X with formula [O(CH2)4]q(OC2H4)x(OC3H6)y[O(CH2)5(CO)]z, wherein q=0 to 10, preferably 0, x=0 to 20, preferably 0, y=0 to 20, preferably 0, z=0 to 10, preferably 0. The sequence of the subformulae indicated q, x, y and z may be varied at will and the indices q, x, y and z in each case only state the number of instances of the particular subformulae. In the event that at least two of the indices q, x, y and z are not equal to 0 or not equal to 1, identical subformulae may be present in any desired sequence or in the form of blocks of two or more successive identical subformulae. Examples of compounds (III) containing groups X are the derivatives formed by ethoxylation, propoxylation, etherification with polytetrahydrofurandiol and/or by reaction with caprolactone of the compounds stated above to be preferred examples of monohydroxy compounds of the formula (III). The compounds (IV) usable in the production of the polyurethaneurea resins according to the invention comprise (cyclo)alkane polyols of the formula R4(OH)a+b+c esterified on b+c hydroxyl groups with (meth)acrylic acid, the a hydroxyl groups of which may be derivatised with groups X. The groups X have the same meaning as explained in the paragraph above relating to the compounds (III). The compounds (IV) preferably contain no groups X. Examples of compounds (IV) are trimethylolpropane mono- and di(meth)acrylate, glycerol mono- and di(meth)acrylate, pentaerythritol di- and tri(meth)acrylate, dipentaerythritol tetra- and penta(meth)acrylate or derivatives thereof containing groups X. The further compounds (A) capable of addition onto isocyanate groups comprise polyols, polyamines or aminoalcohols, for example, the polyols, polyamines or aminoalcohols already mentioned above in connection with the production of isocyanate-functional polyurethane prepolymers or isocyanate-functional polyurethaneurea prepolymers. They may, however, also comprise compounds which are monofunctional with regard to a reaction with isocyanate groups, such as monoalcohols or primary or secondary monoamines. Both monoalcohols (A) and polyols (A) may comprise, apart from the hydroxyl groups, additional groups inert towards isocyanate groups, for example, carboxyl groups or (meth)acryloyl groups. Examples are compounds such as malic acid, dimethylolpropionic acid, dimethylolbutyric acid, tartaric acid, polyester polyols containing carboxyl groups, simultaneously hydroxy- and carboxy-functional (meth)acrylic copolymers, hydroxyalkyl(meth)acrylates, glycerol mono(meth)acrylate, glycerol di(meth)acrylate, trimethylolpropane mono(meth)acrylate, trimethylolpropane di(meth)acrylate. The polyurethaneurea resins according to the invention are produced under the conventional conditions known to the person skilled in the art for the production of polyurethanes or polyureas from polyisocyanates and polyol or polyamine compounds, for example, at temperatures in the range from 20 to 100° C. In particular, the reaction is performed with exclusion of moisture and, when a solvent-free method is not used, using solvents which are inert towards isocyanate groups and alkoxysilane groups. It is obvious to the person skilled in the art in the area of polyurethane or polyurea chemistry that the polyurethaneurea resins according to the invention may be varied in many different respects and to differing extents, for example, with regard to functionality, molar mass, structure, chemical properties and physical properties such as, for example, glass transition temperature or melting temperature. The person skilled in the art is aware of the means and methods available for influencing such features and thus technical properties. In particular, such means and methods comprise an appropriate selection from among the above-described starting materials with regard to nature and quantity and the type of reaction control during synthesis, for example, the sequence and rate of addition of the starting materials, and temperature control. The polyurethaneurea resins according to the invention may be used directly, in particular as binders in compositions which cure on exposure to moisture, in particular on exposure to atmospheric humidity. Curing proceeds in this case by hydrolysis and condensation of the trialkoxysilane groups of the formulae (I) and (II) respectively with elimination of alcohol and formation of siloxane bridges. Moisture curing may proceed over a wide temperature range of, for example, from 20 to 200° C. In the event that the polyurethaneurea resins according to the invention also contain, in addition to the trialkoxysilane groups of the formulae (I) and/or (II), further functional groups which are available for crosslinking reactions, so-called dual-cure compositions may also be formulated with the polyurethaneurea resins. Dual-cure compositions may be purely thermally curable dual-cure compositions or compositions which cure on exposure to high-energy radiation and thermally. High-energy radiation means UV (ultraviolet) or electron beam radiation. Thermally curable dual-cure compositions are characterized by binder/crosslinking agent systems which, on supply of thermal energy, i.e., heat, cure by means of more than one, generally two, different crosslinking reactions. For example, if, apart from the trialkoxysilane functions of groups (I) and/or (II), the polyurethaneurea resins according to the invention additionally contain hydroxyl groups, catalyzed compositions formulated therewith may be cured as a self-crosslinking dual-cure system both by means of the moisture curing already explained above and by condensation of the hydroxyl and trialkoxysilane groups. If, apart from the trialkoxysilane functions of groups (I) and/or (II), the polyurethaneurea resins additionally contain, for example, (meth)acryloyl groups, compositions formulated therewith, which contain thermal free-radical initiators, such as peroxide or azo initiators, may be cured thermally by free-radical polymerization of the (meth)acryloyl groups and also thermally by means of the moisture curing already explained above. Dual-cure compositions which cure thermally and on exposure to high-energy radiation are characterized by binder/crosslinking agent systems which contain components or groups which allow for thermal cure as well as for cure on exposure to high-energy radiation. For example, if, apart from the trialkoxysilane functions of groups (I) and/or (II), the polyurethaneurea resins according to the invention contain (meth)acryloyl groups, compositions formulated therewith may be cured thermally by means of the moisture curing already described above and, by means of free-radical polymerization of the (meth)acryloyl groups, by irradiation with electron beam radiation or, if the compositions contain photoinitiators, by irradiation with UV radiation. The compositions containing the polyurethaneurea resins according to the invention as binders may be solvent-based or solvent-free compositions, for example, adhesives, sealants and/or in particular coating compositions, for example, solvent-based or solvent-free liquid coating compositions or powder coatings. Apart from the polyurethaneurea resin binders, the compositions optionally contain further binders together with conventional constituents known to the person skilled in the art, for example, suitable crosslinking agents for the binders, pigments, extenders, catalysts and/or additives. In the event that they are not directly used as a binder, the polyurethaneurea resins according to the invention may also be chemically modified before they are used as binders. For example, the trialkoxysilane functions of groups (I) and (II) respectively may be hydrolyzed by reaction with water, wherein, depending upon reaction control, polyurethaneurea resins containing siloxane groups and/or silanol groups are obtained, which may be converted into aqueous dispersions by addition of appropriate quantities of water, in particular if the polyurethaneurea resins according to the invention contain hydrophilic groups, such as polyethylene oxide groups or ionic groups or groups convertible into ionic groups by neutralization. Chemical modification of the polyurethaneurea resins according to the invention without using water is, for example, possible if the polyurethaneurea resins contain functional groups which are available for chemical reactions. In this case, the functionality may be modified or defunctionalizations may be performed by a polymer-analogous reaction. The following Example illustrates the production and use of the polyurethaneurea resins according to the invention by way of example of a dual-cure powder coating which cures thermally and on exposure to high-energy radiation. EXAMPLE a) 170 pbw (parts by weight) of isophorone diisocyanate, 0.40 pbw of methylhydroquinone and 0.10 pbw of dibutyltin dilaurate were initially introduced into a 1 litre, three-necked flask fitted with a stirrer, thermometer and dropping funnel and heated to 65° C. At 65° C., 61 pbw of butylethylpropanediol were added in such a manner that the temperature did not exceed 80° C. The temperature was maintained at 80° C. until an NCO value (weight percentage of NCO groups calculated as an MW of 42) of less than 13.9% was obtained. 88.5 pbw of hydroxyethyl acrylate were then added dropwise in such a manner that the temperature did not exceed 90° C. The temperature was maintained at 90° C. for a further 3 h (hours) until the NCO value fell below 0.1%. 61.50 pbw of aminopropyltrimethoxysilane (Dynasilan® AMEO from Degussa) were then added dropwise in such a manner that the temperature did not exceed 100° C. On completion of addition, 76.5 pbw of isophorone diisocyanate were added dropwise in such a manner that the temperature did not exceed 100° C. On completion of addition, the reaction mixture was heated to 120° C. and maintained at this temperature until an NCO value of less than 3.2% was obtained. At 120° C., 31 pbw of hydroxyethyl acrylate and then 11 pbw of butanediol monoacrylate were added dropwise in such a manner that the reaction temperature did not rise above 125° C. Once an NCO value of less than 0.1% had been obtained, the reaction mixture was poured into a flat aluminium dish and broken up once it had solidified. The resultant brittle resin had a number average molecular weight Mn of 1700, a weight average Mw of 3800 and a glass transition determined by means of DSC of 29-41° C. b) A comminuted mixture of the following components was premixed and extruded: 92.5 pbw of the binder from above Example a) 1.0 pbw of Irgacure® 2959 (photoinitiator from Ciba) 2.0 pbw of Powdermate 486 CFL (levelling additive from Troy Chemical Company) 1.5 pbw of Tinuvin® 144 (HALS light stabilizer from Ciba) 1.5 pbw of Tinuvin® CGL 1545 (UV absorber from Ciba) 1.5 pbw of p-toluenesulfonic acid blocked with diisopropylamine A powder clear coating agent was produced after cooling, crushing and sieving of the comminuted mixture. c) The powder clear coating agent from above Example b) was sprayed to a layer thickness of 80 μm onto steel panels coated with conventional electrodeposition primer, primer surfacer and base coat (flashed off) and, once melted, was baked for 20 minutes at 140° C. (object temperature) at a relative atmospheric humidity of 55%. d) Immediately after removal from the baking oven, some of the powder-coated and baked test panels from above Example c) were subjected to additional curing by UV irradiation (medium pressure mercury emitter from Fusion, 240 W/cm, 100% power output, at a UV radiation emitter/object distance of 16 cm, at a belt speed of 3 m/min; corresponding to a radiation intensity of 500 mW/cm2 and a radiation dose of 1500 mJ/cm2). The following Table shows the technical properties of the resultant coatings. Test methods: Thermal only Thermal + UV Amtec scratch resistance 50 85 Xylene test OK OK Acid test 15 25 Amtec scratch resistance, stated as residual gloss after reflow in %: Residual gloss was measured in % (ratio of initial gloss of the clear coat surface to its gloss after wash scratching, gloss measurement in each case being performed at an angle of illumination of 20°). Wash-scratching was performed using an Amtec Kistler laboratory car wash system (c.f. Th. Klimmasch and Th. Engbert, Entwicklung einer einheitlichen Laborprüfinethode für die Beurteilung der Waschstraβenbeständigkeit von Automobil-Decklacken [development of a standard laboratory test method for evaluating resistance of automotive top coats to car wash systems], in DFO proceedings 32, pages 59 to 66, technology seminars, proceedings of the seminar on 29-30.4.97 in Cologne, published by Deutsche Forschungsgesellschaft für Oberflächenbehandlung e.V., Adersstraβe 94, 40215 Düsseldorf). Xylene Test: Brief description: A xylene-soaked filter paper is placed on the coating film and covered by a watch-glass for 10 minutes. Evaluation: OK=no visible change. Acid Test: Brief description: at 65° C., 50 μl drops of 36% sulfuric acid are placed at 1 minute intervals for 30 minutes onto the coating film. Evaluation: Destruction of the film after x (0-30) minutes. | <SOH> BACKGROUND OF THE INVENTION <EOH>Polyurethaneurea resins with trialkoxysilane groups and methods for the production thereof are known per se. For example, isocyanate-functional polyurethane prepolymers and/or isocyanate-functional polyurethaneurea prepolymers may be reacted with trialkoxysilanes carrying primary or secondary amino groups to yield polyurethaneurea resins with terminal trialkoxysilane groups. Such polyurethaneurea resins with trialkoxysilane groups are described, for example, in U.S. Pat. No. 5,760,123 as starting products for the production of aqueous dispersions of polyurethaneurea resins with siloxane bridges. Alternatively, functionalized polyurethaneurea resins may be reacted in a polymer-analogous reaction with suitably functionalized trialkoxysilanes, i.e., trialkoxysilanes which comprise groups which are complementarily reactive towards the functional groups of the polyurethaneurea resins, to yield polyurethaneurea resins with trialkoxysilane groups. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides novel polyurethaneurea resins with trialkoxysilane groups, which differ from hitherto known polyurethaneurea resins with trialkoxysilane groups with regard to the chemical incorporation of the trialkoxysilane groups in the polyurethaneurea resin and thus extend the range of polyurethaneurea resins with trialkoxysilane groups. The invention furthermore provides processes for the production of polyurethaneurea resins, which processes, when required, also permit the polyurethaneurea resins to be provided with a comparatively elevated content of trialkoxysilane groups. When required, the processes also provide an elegant pathway to providing the polyurethaneurea resins with additional functional groups in addition to the trialkoxysilane groups incorporated in the novel manner. The invention relates to polyurethaneurea resins with trialkoxysilane groups, wherein the polyurethaneurea resins contain at least one group of the formula (I) in-line-formulae description="In-line Formulae" end="lead"? —NH(CO)XOR 1 O(CO)CHR 2 CH 2 N[C n H 2n Si(OR 3 ) 3 ](CO)NH— (I) in-line-formulae description="In-line Formulae" end="tail"? and/or at least one group of the formula (II) in-line-formulae description="In-line Formulae" end="lead"? {—NH(CO)XO} a {CH 2 ═CR 2 (CO)O} b R 4 {O(CO)CHR 2 CH 2 N[C n H 2n Si(OR 3 ) 3 ](CO)NH—} c (II) in-line-formulae description="In-line Formulae" end="tail"? wherein X=[O(CH 2 ) 4 ] q (OC 2 H 4 ) x (OC 3 H 6 ) y [O(CH 2 ) 5 (CO)] z ; q=0 to 10, preferably 0; x=0 to 20, preferably 0; y=0 to 20, preferably 0; z=0 to 10, preferably 0; n=2 or 3; a=1 or 2; b=0 to 4, in particular 0; c=1 to 5; R 1 =—C 2 H 4 —, —C 3 H 6 —, —C 4 H 8 —, —CH(CH 2 O(CO)R 5 )CH 2 — or —CH 2 CH(O(CO)R 5 )CH 2 —, preferably —C 2 H 4 —, —C 3 H 6 — or —C 4 H 8 —; R 2 ═H or CH 3 , preferably H; R 3 =C1 to C4 alkyl; R 4 =a+b+c-valent, saturated hydrocarbon residue of a (cyclo)alkane polyol with a+b+c hydroxyl groups; R 5 =an acid residue of a monocarboxylic acid, with the proviso that a+b+c=3 to 6 and wherein the sequence of the subformulae indicated q, x, y and z may be varied at will and q, x, y and z in each case merely state the number of instances of the particular subformulae contained in the formulae (I) and (II). detailed-description description="Detailed Description" end="lead"? | 20040211 | 20070501 | 20050811 | 70485.0 | 0 | NILAND, PATRICK DENNIS | POLYURETHANEUREA RESINS WITH TRIALKOXYSILANE GROUPS AND PROCESSES FOR THE PRODUCTION THEREOF | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,776,552 | ACCEPTED | Bale loader moisture sensing system | A moisture sensing system for use with a bale loading vehicle. The moisture sensing system includes one or more probes that are inserted into the center of a hay bale or other agricultural product that obtain moisture readings of the product. The moisture readings are stored in memory, and may be printed in a report of moistures over a certain period of time, in a certain location, in a certain lot number, in a certain truckload, or other grouping of bales. | 1. A moisture sensing system for use on a bale lifting vehicle, comprising: one or more bale penetrating rods mounted to said vehicle, for insertion into a bale of product; one or more moisture sensing probes, attached to said one or more bale penetrating rods, each probe with spaced apart electrodes for moisture sensing contact with a product in bale form; a sensor readout mounted on said vehicle in a position visible to a vehicle driver; wherein said bale penetrating probes penetrate said bale and take a moisture reading when said bale lifting vehicle moves adjacent a bale, and a driver of said can read the moisture of said bale while driving said vehicle. 2. The moisture sensing system of claim 1 in which said bale penetrating rods are the rods normally used by the vehicle to lift and move said bales, and said moisture sensing probes are mounted on existing rods for use with the moisture sensing system. 3. The moisture sensing system of claim 1 in which the moisture sensing probes are configured to test the moisture in the center of the bale of hay. 4. The moisture sensing system of claim 1 in which said moisture sensing probes a capable of sensing moisture as the probe is inserted into the bale, and give one or more moisture readings of the path of insertion of the probe. 5. The moisture sensing system of claim 1 in which a plurality of sensors are present, and used to test moisture at several areas of the bale. 6. The moisture sensing system of claim 5 which includes a moisture indicator which is an average of the readings of several moisture sensors. 7. The moisture sensing system of claim 1 which includes an alert set point, and an alarm, wherein a user may select a specific moisture content as the alert set point, and if any moisture readings exceed the alert set point, a signal notifies the user that the alert set point has been exceeded. 8. The moisture sensing system of claim 7 in which said alarm is a visual alarm. 9. The moisture sensing system of claim 7 in which said alarm is an audio alarm. 10. The moisture sensing system of claim 1 which includes a memory storage device, in which moisture readings of bales are recorded and saved, for later use. 11. The moisture sensing system of claim 10 which includes a printing device for printing out moisture content information of bales that have been sampled. 12. The moisture sensing system of claim 11 in which said printing device is configured to print a report of moisture of a selected lot of bales. 13. The moisture sensing system of claim 12 in which report lists an average moisture content for each bale in said selected lot of bales. 14. A moisture sensing system for use on a bale lifting vehicle, comprising: one or more bale penetrating rods mounted to said vehicle, for insertion into a bale of product; a plurality of moisture sensing probes, attached to said one or more bale penetrating rod each probe with spaced apart electrodes for moisture sensing contact with a product in bale form; a sensor readout mounted on said vehicle in a position visible to a vehicle driver; an alert set point, and an alarm, wherein a user may select a moisture content as the alert set point, and if any moisture readings exceed the alert set point, a signal notifies the user that the alert set point has been exceeded; a memory storage device, in which moisture readings of bales are recorded and saved; a printing device for printing out moisture content information of bales that have been sampled; wherein said bale penetrating probes penetrate said bale and take a moisture reading when said bale lifting vehicle moves adjacent a bale, and a driver of said can read the moisture of said bale while driving said vehicle. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to moisture sensors, and more particularly relates to moisture sensors mounted on vehicles for moving agricultural products. 2. Background Information Agricultural products such as hay, alfalfa, grass, straw, cotton, and other fibrous materials are packed into bales of various shapes during part of their processing. The bales can be large cylindrical bales, small rectangular bales, or large rectangular bales. These agricultural products will be referred to as hay bales, but may include any type of baled agricultural product. The bales are typically stacked either side-by-side or in a multi-layer configuration. The bales may be covered by plastic or placed under a covering or left out in the open. The moisture content of the agricultural product can be a problem with such baled products. If the moisture content is too high, the wet areas of the bale can produce heat, and the heat can be sufficient to start a fire therein. When a bale catches fire, it can cause neighboring bales to catch fire and the entire haystack, along with the barn or shed it is in, can be destroyed by fire. This is a problem for people who grow such agricultural products, transport, store, buy, and insure them. Such fires usually occur within six weeks of baling, but may occur in hay several years old. Fire can occur in loose hay and all types of bales or stacks. Fires can occur in hay stored inside or outside. The fires are caused by the growth of microorganisms in the hay. As a microorganism feeds and multiplies, they generate heat. If the moisture content of the hay is high enough, this allows the microorganisms to grow. If the moisture content is in the center of the bale, then heat begins to be produced, which is slow to dissipate from the center of a large bale. Certain bacteria grow well in hot conditions. These are called thermophilic (heat loving) bacteria. When microorganisms cause an elevated temperature, the presence of thermophilic bacteria allows them to begin growing in the more intense temperatures and they can then boost temperatures to a higher level. At these higher temperatures, carbon in the hay combines readily with oxygen and the heated hay can self ignite in the presence of air. This process causes spontaneous combustion of the hay. Therefore, it is important to know the moisture content of the hay, especially in the center. There are numerous moisture sensors in the prior art, such as moisture probes that are inserted by hand into a hay bale, or which are mounted on the hay baler itself. The hay baler mounted moisture sensors have a sensor on the side of a chute down which the hay bale travels. As the hay bale travels down the chute, the moisture sensor determines the moisture of the hay on the exterior of the bale. However, it does not sense the moisture of the hay in the interior of the bale. After baling, the bale may gradually dry over a period of time. One step in the operation that would make the most difference in preventing hay fires is the step of loading, transporting, or stacking hay bales. If at this step the moisture content in the interior of a hay bale could be sensed, bales that have moist centers could be segregated and dealt with. This would have the advantage of eliminating hay fires and thus eliminating the loss of the agricultural product as well as the barn or structure that it is enclosed within. This would also be of benefit to insurance companies. If the insurance company knew the moisture content of a group of bales, the insurance company could insure the agricultural product at a lower price, thus saving the grower money in premiums. The ideal time to take the moisture sensing step is when a bale loading vehicle is moving the bale from one place to another, as the bales are loaded into a truck, stacked in a barn, or moved from the field to a shed. In addition to sensing the moisture while a bale is being moved, such a moisture sensing vehicle could test the moisture of bales merely by driving up to the bale and taking a moisture reading. What is missing in the prior art and therefore what is needed, is a moisture sensing system that is operated in conjunction with a bale lifting vehicle. Such a moisture sensing system would be able to sense the moisture of an interior of a hay bale, preferably at more than one point. It would also have a moisture readout that is visible to the vehicle's operator, so that moisture readings could be taken and evaluated without the operator leaving the seat of the vehicle. Ideally such a system would have a way to record moisture and enter information about bale numbers, lot numbers, bale locations, barn numbers, and other information related to identifying such bales. Such a device would also have the ability to store such information in memory, and print it out when a report was necessary. The report could be utilized by the farmer to obtain better insurance rates, by the shipper to know that the shipping container would not be destroyed by fire, by transporters to ensure that their equipment is not at risk by fire, and by the grower to verify that the hay is not in danger of burning. They hay purchaser would also benefit by this report, whether generated by the farmer or by the purchaser. SUMMARY OF THE INVENTION These and other objects are accomplished by the moisture sensing system of the present invention. This system is for use on bale lifting vehicles such as front-end loaders, tractors, pickup trucks, forklifts, and other vehicles that are configured for lifting hay bales. Each of these vehicles can be outfitted with bale lifting equipment such as spears, forks or clamps, by which these vehicles can lift and move a bale of hay. The moisture sensing system includes one or more bale penetrating rods mounted to the vehicle or to the bale lifting attachment of the vehicle. A bale penetrating rod is for insertion into a bale of product in order to test the moisture of the product in the interior of the bale or stack. The system also includes one or moisture sensing probes, which are attached to the bale penetrating rods. Each probe includes electrodes that are spaced apart from each other so that electrical current between the electrodes can be utilized to determine the moisture content in the bale. The product that can be tested in the moisture sensing system can be any type of agricultural product, such as hay, alfalfa, hay, grass, straw, cotton, and any other fibrous product. The system includes a sensor readout that is mounted on the vehicle in a position that is visible to the vehicle's operator. The system is designed to penetrate the bale with the bale penetrating probes, and take a moisture reading when the bale lifting vehicle moves adjacent a bale. Once adjacent a bale and with the bale penetrating probe inside the bale, the driver of the vehicle can read the moisture content of the bale from inside the vehicle. Once the moisture is sensed, the bale would typically be lifted and transported to another location. However, transportation of the bale is not required, and the moisture can be sensed on a bale without moving it. The device can utilize the spears or rods of a bale lifting vehicle to serve as the bale penetrating rods of the sensor. In that case, the moisture sensing probe would be attached to the rods or spears that are used by the vehicle to lift and/or move bales. The preferred arrangement for moisture sensing is for the moisture sensing probes to sense the moisture in the approximate center of the bale of hay. If more than one moisture sensing probe is present in a particular configuration of the system, a number of positions in the hay bale are sensed for moisture and the readings may be displayed either as an average, or showing the individual moisture readings. One desirable configuration of the system is to have moisture sensing probes that are capable of sensing the moisture of the bale as the probe is inserted into the bale. In this way, each probe would give a moisture reading of the path of insertion into the bale. Once again, these individual moisture readouts could be displayed as an average for that particular path of insertion or as discrete readings as the probe enters the bale. The system can also include a moisture alert set point. A user would select a certain moisture percentage that would indicate a problem with a bale. Once the alert set point has been specified, if any moisture readings exceed that set point, a signal notifies a user that the alert set point has been reached or exceeded. The signal could be a visual alarm, such as a flashing red light, or it could be an audible tone such as a buzzer or alarm, or it could be a combination of both visual and audible alarms. One embodiment of the moisture sensing system includes a memory storage device, such as computer with RAM memory. Moisture readings of bales can be recorded in the computer memory for later use. This version of the device would also include a printing device for printing out moisture content information of bales that have been sampled. One option with this variation of the device is to print a report of the moisture content of a selected lot of bales. In this way, a farmer would present the report of moisture of hay bales to an insurance company in order to receive lower premiums for coverage of the hay bales in that group. Other groupings of moisture readings could be provided, such as a report with the moisture of hay bales for an entire day, the moisture of hay bales in a certain lot, or the moisture of hay bales in a certain location. Each of these reports would be of value to the farmer and the insurance company. An information input device would also be an optional feature of such a system, so that the driver could input information about bale numbers, lot numbers, stack numbers, building names and numbers, date and time, and other information about the hay bales being sampled. Further, the purpose of the foregoing abstract is to enable the United States Patent and Trademark Office and the public generally, and especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measure by the claims, nor is it intended to be limiting as to the scope of the invention in any way. Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive in nature. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective drawing of the moisture sensing system of the present invention. FIG. 2 is a side view of the moisture sensing system in use with a bale and a loader. FIG. 3 is a view of a computer screen with features of a recording system of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims. While the present invention is described with hay bales, it is to be distinctly understood that any agricultural product that is processed into variously shaped and sized bales can be utilized with the present invention. Several preferred embodiments of the present invention are shown to advantage in FIGS. 1-3. FIG. 1 shows one version of a moisture sensing system 10 mounted on a bale fork 12. The bale fork 12 would typically be mounted on a loader 14 as shown in FIG. 2. The moisture sensing system 10 is incorporated into the bale fork 12, and can take a number of different forms and be mounted on a number of different vehicles. For instance, bale forks can have a large number of configurations with different numbers of bale spears 16. Some bale lifting devices are clamps that clamp around the outside of a bale similar to giant tongs. The moisture sensing system of the present invention can also work with clamp type bale lifters. Other types of bale forks include bales forks that have curved hooks that rotate and engage a bale. The moisture sensing system of the present invention also works with this type of system or any other type of hay lifting system. Shown in FIG. 2 is a loader, which is one typical way to lift large bales. Other vehicles can also be utilized with a variety of bale forks, including tractors, forklifts, and even pickup trucks. The moisture sensing system of the present invention includes a bale penetrating rod 18. On the bale penetrating rod 18 are a pair of spaced apart electrodes 20, which together form a moisture sensing probe. A sensor readout 22 is operatively connected to the moisture sensing probe 24. Although this is shown in FIG. 1 by use of a wire connection 26, wireless technology could also be utilized to transmit a signal from the moisture sensing probe 24 to the sensor readout 22. The sensor readout 22 is configured to be mounted in a cab 28 of the vehicle so that the operator may read it as he/she pushes the bale fork 12 into a bale of hay 30. Associated with the sensor readout 22 of a preferred embodiment of the present invention is an alarm that can could be a flashing light, a light of a certain color, a sound generating device, or a combination of light and sound. The alarm sounds when a moisture reading is taken that exceeds an alert set point. The preferred embodiment of the present invention includes an alert set point that may be specified by the operator. For instance, if it is determined that the alert set point of the day is to be 15% moisture, the drive would enter 15% moisture into the memory of the computing device associated with sensory readout 22. Thereafter, when any bales were sensed with a moisture higher than 15%, the alarm would go off alerting the operator that a higher than acceptable moisture reading had been taken. The moisture sensing system preferably includes a computer with memory, in which the alert set point is recorded, and in which moisture readings of hay bales are also recorded. The memory is preferably configurable so that moisture readings may be grouped according to date, bale lot number, barn number, etc. In this way, moisture information that has been taken during a certain period of time or in a certain building may be grouped together and printed out in a report. This serves as quality control for the producer, as well as for the shipper or purchaser, who does not want to purchase hay bales with high moisture content. This also is a reassurance to an insurer, who might be able to provide lower rates for hay bales that have been tested and recorded. This is an advantage to the grower or person storing the hay bales because he/she can obtainer cheaper insurance rates. The computer is associated with the sensor readout 22 and can take many forms. It can be in the form of a PDA, which is configured to receive moisture data from the moisture sensing probe 24 and record it using its software. It can also be a device that utilizes removable memory, such as a memory chip, disk, or CD, on which information can be recorded and removed from the vehicle to be placed in storage or further processed at a later date. It is also possible that a computing device would be configured to print out reports in the bale loading vehicle itself. The computing means of the moisture sensing system will have a number of features, including input of data, including date, time, bale number, lot number, truck number, building number, farm name and number, and other information that will identify the sample bale. It will also have the ability to input and store measured moisture readings. When the moisture probe is inserted into a hay bale, a moisture reading is taken either when the sensor reaches equilibrium, or as the sensor is being pushed into the hay bale. In either case, a moisture value is recorded. The recording of the moisture value can be performed automatically, or it can include a manual input button, such as a button on a touch screen or a computer face, which would cause the sensed moisture to be recorded. One embodiment of this system can include an automatic moisture reading trigger 30, which is a mechanical device that is tripped every time a hay bale is loaded on the bale fork 12. This device is shown in FIG. 1 as a bale sensing disk 32, a spring 34, and a contact 36. When the bale fork is fully pressed into a bale, the bale sensing disk 32 is pressed toward the frame of the bale fork 12. In doing so, the spring 34 is compressed and eventually the bale sense disk 32 touches the contact 36, which initiates the recording of a moisture reading. In this way, every time a bale is loaded onto the bale fork 12, a moisture reading would be initiated and recorded. Another preferred embodiment of the device includes a manual entry of the moisture reading. This could be performed by the operator pressing an entry button when the reading is taken, which enters the value at that time into memory. The entry button could be on a touch screen or on the face of the computer or a button accessible to the driver inside the cab. FIG. 1 shows a bale fork utilizing two bale spears 16. Also shown is one bale penetrating rod 18. Another preferred embodiment of the present invention utilizes a number of bale sensing probes. FIG. 2 shows an embodiment of the present invention in which multiple moisture sensing probes 24 are utilized. The moisture sensing system can also be utilized on bale forks by modifying the existing bale spears 16. For instance, a portion of the bale spears 16 could be cut off and replaced with a moisture sensing probe 24. In this way, a bale fork that had five bale spears 16, could be modified to include one or more moisture sensing probes 24 to be attached to the tip of the bale spears 16. When utilized with a system of multiple moisture sensing probes 24, the computer would have the capability of recording all of the moistures, the moistures along the path of probe insertion, and the average of the moisture readings, whichever is preferred by the operator. FIG. 3 shows one possible configuration of the options available in the computer 38. These include a button to enter information, to begin recording bale moistures, to choose either auto or manual record mode, to enter lot numbers, bale numbers, dates, and alert set point, to move a cursor up, down, left, or right, or to print bale moistures. Each of these features could be displayed in a PDA, laptop computer, or other computing means, including a cellular telephone, a desktop computer linked to the moisture sensing system 10, or other computing means as they become available with the development of this technology. While there is shown and described the present preferred embodiment of the invention, it is to be distinctly understood that this invention is not limited thereto but may be variously embodied to practice within the scope of the following claims. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention generally relates to moisture sensors, and more particularly relates to moisture sensors mounted on vehicles for moving agricultural products. 2. Background Information Agricultural products such as hay, alfalfa, grass, straw, cotton, and other fibrous materials are packed into bales of various shapes during part of their processing. The bales can be large cylindrical bales, small rectangular bales, or large rectangular bales. These agricultural products will be referred to as hay bales, but may include any type of baled agricultural product. The bales are typically stacked either side-by-side or in a multi-layer configuration. The bales may be covered by plastic or placed under a covering or left out in the open. The moisture content of the agricultural product can be a problem with such baled products. If the moisture content is too high, the wet areas of the bale can produce heat, and the heat can be sufficient to start a fire therein. When a bale catches fire, it can cause neighboring bales to catch fire and the entire haystack, along with the barn or shed it is in, can be destroyed by fire. This is a problem for people who grow such agricultural products, transport, store, buy, and insure them. Such fires usually occur within six weeks of baling, but may occur in hay several years old. Fire can occur in loose hay and all types of bales or stacks. Fires can occur in hay stored inside or outside. The fires are caused by the growth of microorganisms in the hay. As a microorganism feeds and multiplies, they generate heat. If the moisture content of the hay is high enough, this allows the microorganisms to grow. If the moisture content is in the center of the bale, then heat begins to be produced, which is slow to dissipate from the center of a large bale. Certain bacteria grow well in hot conditions. These are called thermophilic (heat loving) bacteria. When microorganisms cause an elevated temperature, the presence of thermophilic bacteria allows them to begin growing in the more intense temperatures and they can then boost temperatures to a higher level. At these higher temperatures, carbon in the hay combines readily with oxygen and the heated hay can self ignite in the presence of air. This process causes spontaneous combustion of the hay. Therefore, it is important to know the moisture content of the hay, especially in the center. There are numerous moisture sensors in the prior art, such as moisture probes that are inserted by hand into a hay bale, or which are mounted on the hay baler itself. The hay baler mounted moisture sensors have a sensor on the side of a chute down which the hay bale travels. As the hay bale travels down the chute, the moisture sensor determines the moisture of the hay on the exterior of the bale. However, it does not sense the moisture of the hay in the interior of the bale. After baling, the bale may gradually dry over a period of time. One step in the operation that would make the most difference in preventing hay fires is the step of loading, transporting, or stacking hay bales. If at this step the moisture content in the interior of a hay bale could be sensed, bales that have moist centers could be segregated and dealt with. This would have the advantage of eliminating hay fires and thus eliminating the loss of the agricultural product as well as the barn or structure that it is enclosed within. This would also be of benefit to insurance companies. If the insurance company knew the moisture content of a group of bales, the insurance company could insure the agricultural product at a lower price, thus saving the grower money in premiums. The ideal time to take the moisture sensing step is when a bale loading vehicle is moving the bale from one place to another, as the bales are loaded into a truck, stacked in a barn, or moved from the field to a shed. In addition to sensing the moisture while a bale is being moved, such a moisture sensing vehicle could test the moisture of bales merely by driving up to the bale and taking a moisture reading. What is missing in the prior art and therefore what is needed, is a moisture sensing system that is operated in conjunction with a bale lifting vehicle. Such a moisture sensing system would be able to sense the moisture of an interior of a hay bale, preferably at more than one point. It would also have a moisture readout that is visible to the vehicle's operator, so that moisture readings could be taken and evaluated without the operator leaving the seat of the vehicle. Ideally such a system would have a way to record moisture and enter information about bale numbers, lot numbers, bale locations, barn numbers, and other information related to identifying such bales. Such a device would also have the ability to store such information in memory, and print it out when a report was necessary. The report could be utilized by the farmer to obtain better insurance rates, by the shipper to know that the shipping container would not be destroyed by fire, by transporters to ensure that their equipment is not at risk by fire, and by the grower to verify that the hay is not in danger of burning. They hay purchaser would also benefit by this report, whether generated by the farmer or by the purchaser. | <SOH> SUMMARY OF THE INVENTION <EOH>These and other objects are accomplished by the moisture sensing system of the present invention. This system is for use on bale lifting vehicles such as front-end loaders, tractors, pickup trucks, forklifts, and other vehicles that are configured for lifting hay bales. Each of these vehicles can be outfitted with bale lifting equipment such as spears, forks or clamps, by which these vehicles can lift and move a bale of hay. The moisture sensing system includes one or more bale penetrating rods mounted to the vehicle or to the bale lifting attachment of the vehicle. A bale penetrating rod is for insertion into a bale of product in order to test the moisture of the product in the interior of the bale or stack. The system also includes one or moisture sensing probes, which are attached to the bale penetrating rods. Each probe includes electrodes that are spaced apart from each other so that electrical current between the electrodes can be utilized to determine the moisture content in the bale. The product that can be tested in the moisture sensing system can be any type of agricultural product, such as hay, alfalfa, hay, grass, straw, cotton, and any other fibrous product. The system includes a sensor readout that is mounted on the vehicle in a position that is visible to the vehicle's operator. The system is designed to penetrate the bale with the bale penetrating probes, and take a moisture reading when the bale lifting vehicle moves adjacent a bale. Once adjacent a bale and with the bale penetrating probe inside the bale, the driver of the vehicle can read the moisture content of the bale from inside the vehicle. Once the moisture is sensed, the bale would typically be lifted and transported to another location. However, transportation of the bale is not required, and the moisture can be sensed on a bale without moving it. The device can utilize the spears or rods of a bale lifting vehicle to serve as the bale penetrating rods of the sensor. In that case, the moisture sensing probe would be attached to the rods or spears that are used by the vehicle to lift and/or move bales. The preferred arrangement for moisture sensing is for the moisture sensing probes to sense the moisture in the approximate center of the bale of hay. If more than one moisture sensing probe is present in a particular configuration of the system, a number of positions in the hay bale are sensed for moisture and the readings may be displayed either as an average, or showing the individual moisture readings. One desirable configuration of the system is to have moisture sensing probes that are capable of sensing the moisture of the bale as the probe is inserted into the bale. In this way, each probe would give a moisture reading of the path of insertion into the bale. Once again, these individual moisture readouts could be displayed as an average for that particular path of insertion or as discrete readings as the probe enters the bale. The system can also include a moisture alert set point. A user would select a certain moisture percentage that would indicate a problem with a bale. Once the alert set point has been specified, if any moisture readings exceed that set point, a signal notifies a user that the alert set point has been reached or exceeded. The signal could be a visual alarm, such as a flashing red light, or it could be an audible tone such as a buzzer or alarm, or it could be a combination of both visual and audible alarms. One embodiment of the moisture sensing system includes a memory storage device, such as computer with RAM memory. Moisture readings of bales can be recorded in the computer memory for later use. This version of the device would also include a printing device for printing out moisture content information of bales that have been sampled. One option with this variation of the device is to print a report of the moisture content of a selected lot of bales. In this way, a farmer would present the report of moisture of hay bales to an insurance company in order to receive lower premiums for coverage of the hay bales in that group. Other groupings of moisture readings could be provided, such as a report with the moisture of hay bales for an entire day, the moisture of hay bales in a certain lot, or the moisture of hay bales in a certain location. Each of these reports would be of value to the farmer and the insurance company. An information input device would also be an optional feature of such a system, so that the driver could input information about bale numbers, lot numbers, stack numbers, building names and numbers, date and time, and other information about the hay bales being sampled. Further, the purpose of the foregoing abstract is to enable the United States Patent and Trademark Office and the public generally, and especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measure by the claims, nor is it intended to be limiting as to the scope of the invention in any way. Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive in nature. | 20040210 | 20061003 | 20050811 | 73646.0 | 0 | RAEVIS, ROBERT R | BALE LOADER MOISTURE SENSING SYSTEM | SMALL | 0 | ACCEPTED | 2,004 |
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10,776,691 | ACCEPTED | Method for identifying a movement of single tap on a touch device | A method for identifying a movement of single tap includes having detected the movement of the object contacting the touch device initiating to start time counting, having detected the movement of the object contacting the touch device terminating and a first time span being obtained and generating a control signal indicating the movement of single tap in case of the first time span being less than a second time span, the first time span being greater than a preset time span and only one contacting time being greater than the preset time with the second time span. | 1. A method for identifying a movement of single tap, which is a movement done with at least an object contacting a touch device, comprising following steps: (A) having detected the movement of the object contacting the touch device initiating with starting time counting; (B) having detected the movement of the object contacting the touch device terminating and a first time span being obtained; and (C) generating a control signal indicating the movement of single tap in case of the first time span being less than a second time span, the first time span being greater than a preset time span and only one contacting time being greater than the preset time with the second time span. 2. The method for identifying a movement of single tap as defined in claim 1, wherein the step C further determines contact position coordinates of the object contacting with the touch device are in a legal zone for single tap before the control signal of single tap movement. 3. A controller of a touch device, which sends at least a control signal to a main unit corresponding to a movement of at least an object contacting the touch device, comprising: a coordinate calculating unit, detecting an electronic signal sent by the touch device to figure out a coordinate position of the object contacting the touch device; a detecting contact unit, detecting the electronic signal sent by the touch device to determine if the object contacts the touch device; a counting time unit, counting time during the object contacting the touch device; an operation unit, figuring out a first time span of the object contacting the touch device during the object terminating contacting the touch device according to a result of the determination done by the detecting contact unit, controlling the counting time unit to start time counting in case of the object contacts the touch device and generating a control signal indicating the single tap in case of the first time span being less than a second time span, the first time span being greater than a preset time span and only one contacting time being greater than the preset time in the second time span; and an encoding unit, encoding the control signal and the coordinate position and sending the encoded data to the main unit. 4. The controller as defined in claim 3, wherein the operation unit generates the control signal after the operation unit having determined the coordinate position of the object contacting the touch device being within a legal position of single movement. | BACKGROUND OF THE INVENTION 1. Field of Invention The present invention is related to a method for identifying a movement of single tap on a touch device, particularly to an identifying method capable of resisting noise effectively and enhancing identification rate and a controller utilizing the method. 2. Brief Description of Related Art The touch pad is a humanized input device in spite of the conventional input devices such as keyboard, mouse and locus ball being unable to satisfy need of the user. Further, a trend of designing electronic products is to pursue lightness, thinness, shortness and smallness so that it is not possible to integrate all kinds of input devices in a single electronic product. Because the touch pad can provide the user a humanized operation with handwriting input and has the function of the conventional input devices at the same time, the touch pad has become the most popular choice. Referring to FIG. 1, the touch pad 10 can access analog/digital conversion and figure out coordinates of the touch point with a controller 20 after producing analog signals of voltage. Meanwhile, the controller 20 can identify if the user produce a single tap or click, double taps or clicks, a drag or a movement and then sends related control signal to a main unit 30 to control the cursor on a screen 40 of the main unit 30 accessing movements of shifting, selecting an item and executing a program. The analog/digital converter (not shown) in the controller 20 can be interfered by foreign noise such as electromagnetic wave easily so that it is necessary to add proper samples and recognition algorithm in addition to requiring careful layout of internal circuit and increasing various filters for solving the problem. Otherwise, the noise is easy to result in phenomenon of temporary pseudo press or pseudo exit such that the controller 20 erroneously determines the movement. U.S. Pat. No. 6,380,931 discloses an identifying method of single tap with a touch device and a brief summary thereof is described hereinafter. Referring FIG. 2, firstly, it is to detect if an object such as touch pen contacts the touch device as shown in step 201 and then it is to compare time T of the object with a default value Tmax and check if T is smaller than Tmax as shown in step 202. Further, it is to make sure if displacement S of the object on the touch device is smaller than a default value Smax as shown in step 203. In case of meeting the preceding two conditions, determination of single tap movement can be made and a control signal of representing the single tap and information regarding coordinates of position at the spot of clicking can be sent to the main unit. However, the preceding method is not possible to resist noise, which is apt to produce phenomenon of pseudo press. Especially in order to comply with calculation of the two restrictions (contact time and displacement), the set up cost of the logic circuit is expensive too. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method, which can filter unnecessary noise effectively for enhancing accuracy of identifying a movement of single tap, and a controller thereof. Wherein, the controller, which sends at least a control signal to a main unit corresponding to a movement of at least an object contacting the touch device, comprises a coordinate calculating unit, a detecting contact unit, a counting time unit, an operation unit and an encoding unit. The coordinate calculating unit detects an electronic signal sent by the touch device to figure out a coordinate position of the object contacting the touch device. The detecting contact unit detects the electronic signal sent by the touch device to determine if the object contacts the touch device. The operation unit figures out a first time span of the object contacting the touch device during the object terminating contacting the touch device according to a result of the determination done by the detecting contact unit, controls the counting time unit to start time counting in case of the object contacts the touch device and generates a control signal indicating the single tap in case of the first time span being less than a second time span, the first time span being greater than a preset time span and only one contacting time being greater than the preset time in the second time span. The encoding unit encodes the control signal and the coordinate position and sending the encoded data to the main unit. The method for identifying a movement of single tap according to the present invention is to have detected the movement of the object contacting the touch device initiating time counting and have detected the movement of the object contacting the touch device being terminated and a first time span being obtained. Finally, a control signal indicating the movement of single tap can be obtained in case of the first time span being less than a second time span, the first time span being greater than a preset time span and only one contacting time being greater than the preset time with the second time span. In short, the present invention provides another restriction regarding if the time span of the object contacting the touch device is greater than the first time span and smaller than the second time span in addition to the restriction regarding if only one contact movement in the second time span. Hence, it is capable of resisting noise effectively to enhance accuracy of recognizing movements. Moreover, due to being not necessary to provide a restriction of displacement, it is possible to lower down the set up cost for logic circuit. BRIEF DESCRIPTION OF THE DRAWINGS The detail structure, the applied principle, the function and the effectiveness of the present invention can be more fully understood with reference to the following description and accompanying drawings, in which: FIG. 1 is a block diagram illustrating relationship between a touch device, a controller and a main unit; FIG. 2 is a flow chart illustrating steps in a method for identifying the movement of single tap disclosed in U.S. Pat. No. 6,380,931; FIG. 3 is a block diagram illustrating a preferred embodiment of a controller in the touch device of the present invention; FIG. 4 is a flow chart illustrating steps in a method for identifying the movement of single tap according to the present invention; and FIG. 5 a graph of time sequence illustrating control signals being produced corresponding to the movement of correct single tap according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 3, the controller 100 of a touch device 300 is used for identifying a movement of an object 200 on the touch device 300 and sending a control signal corresponding the movement to a main unit 400. It is noted that the touch device 300 can be a capacitance type, inductance type and the like. The capacitance type of touch device 300 is specifically used for the embodiment. The object 200 is utilized to contact with the touch device 300, that is, the movement of the object 200 on the touch device 300 results in the controller 100 sending a control signal, which corresponds to the movement, to the main unit 400. Generally, the control signal can be coordinates change, a tap, double taps, a drag, a movement, scrolling, a left key, a right key, a middle key and etc. to simulate behaviors of a mouse and a keyboard further. The main unit 400 can be various electronic devices such as a desktop computer, a note book computer, a personal digital assistant (PDA), a cellular phone, a remote controller for different electric appliances or any other input device for the electronic devices. A preferred embodiment of the controller 100 includes a analog/digital switching unit 1, a coordinate calculating unit 2, a detecting contact unit 3, an operation unit 4, an encoding unit 5, a transmission interface unit 6 and a timer unit 7. Because the touch device 300 distributes multiple lead wires in X and Y directions respectively, the touch device 300 will occur a change of capacitance value as soon as the object 200 contacts the touch device 300. Thus, values such as coordinates can be figured out by way of measuring variations of voltages. The analog/digital switching unit 1 is connected to the touch device 300 to convert different voltages into corresponding digital signals for subsequent process. The coordinate calculation unit 2 decodes the digital signal sent from the analog/digital switching unit 1 as corresponding absolute coordinate values (X, Y). The detecting contact unit 3 is capable of detecting if the touch device 300 is pressed with an object and figuring out time duration of the object 200 contacting the touch device 300. The time duration is a parameter for judging which one of the movements, a tap, double tap or drag. The operation unit 4 is connected to the coordinate calculation unit 2 and the detecting contact unit 3. The operation unit 4 is built in a logic calculation method, which can determine if a movement operated by the user meets a condition of a tap, double taps or drag. The present invention emphasizes determination of single tap and a detail explanation about the determination of single tap will be description hereinafter. The operation unit 4 is capable of offering relative displacement except determination of movement, that is, after multiple pairs of absolute coordinate values being transmitted to the operation unit 4 sequentially, the operation unit 4 can figure out a relative displacement of the object 200 on the touch device 300 and even parameters such as velocity, direction and distance of the object 200 according to the difference between two neighboring coordinates. As for whether sending the absolute coordinates or the relative displacement to the main unit 400, it depends on application requirement of the main unit 400. The encoding unit 5 connects with the operation unit 4 so that it is possible for the encoding unit 5 to receive absolute coordinate signal, relative displacement signal or touch signals, which include single tap, double tap and drag. The encoding unit 5 can encode different signals as hand-write input protocol or standard mouse protocol such as mouse standard protocol of Microsoft company or PS/2 mouse standard protocol of IBM company available for operation system of the main unit 400. The transmission interface unit 6 provides a function of sending the encoded signal done by the encoding unit 5 to the main unit 400 in series. Taking a desktop computer as an example, the encoded signal is sent to a keyboard controller (not shown) or South Bridge chip (not shown) so that it is possible to send an interruption request (IRQ) to the processor of the main unit 400. As a result, the main unit 400 can further obtain required parameters such as coordinate location and execution movement and movements such as displacement of the cursor, program selection or program execution can be performed further. Referring to FIGS. 4 and 5, the identifying method of single tap movement according to the present invention at the very first as steps 401, 402 illustrated is utilizing the detecting contact unit 3 to detect the movement of the object 200 on the touch device 300. A positive edge of T1 time span wave (temporary state while lower level position changes to high level position) indicates a movement of contact occurring and the operation unit 4 controls the timer unit 7 to begin counting the time. Next, as indicated in step 403, once the object 200 detaches from the touch device 300 after contacting the touch device 300 a time duration T1 (first time span), the detecting contact unit 3 will detect the movement of contacting the touch device 300 being over. It is a negative edge of the wave shape shown in FIG. 5. Then, step 404 shows that the timer unit 7 terminates counting the time after the time lapsing a second time span T2 from starting counting the time. Step 405 shows that the operation unit 4 determines if the condition of only one contact time duration being greater than a preset time span Tmin of the tap movement except T1 being smaller than the second time span T2 and greater than a preset time span Tmin is fulfilled. If the condition is not fulfilled, the process is moved to step 408 and the operation unit 4 can have judgment of other movements in case of the original judgment being not the movement of single tap. If the condition is fulfilled, step 406 is processed. In order to determine the movement of single tap more accurately, a legal zone (not shown) for the movement of single tap is defined and judgment for position coordinates (X,Y) of the object 200 contacting the touch device 300 being within the legal zone (X1˜X2,Y1˜Y2; X1<X2, Y1<Y2). If the determination in step 406 is ‘YES’ (X1≦X≦X2, Y1≦Y≦Y2), it means the movement is single tap definitely and step 407 is executed to produce a control signal representing the movement of single tap as shown in lower part of FIG. 5 being sent to the main unit 400 via the encoding unit 5 and the transmission interface unit 6. If the determination in step 406 is ‘NO’, it means the movement is not single tap and the process is moved to step 408. In short, in order to obtain the movement of single tap, following conditions have to be met: (1) T2>T1 (2) Tmin<T1 (3) Only one contact time duration is greater than the preset time span Tmin for the movement of tap. (4) X1≦X=≦X2; Y1≦Y≦Y2 It is appreciated that the method and device according to the present invention can resist noise effectively and enhance accuracy of identifying the movement in case of time being counted from the object 200 being started to contact with the touch device 300, a determination of single tap movement being performed within the second time span T2, the first time span T1 being greater than the preset time span Tmin and smaller than the second time span T2 and the contact position coordinates (X,Y) of the object 200 on the touch device 300 being in the legal zone of single tap. Further, internal logic circuit of the controller 300 can be simplified to lower the installation cost and reduce power consumption. While the invention has been described with referencing to a preferred embodiment thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention The present invention is related to a method for identifying a movement of single tap on a touch device, particularly to an identifying method capable of resisting noise effectively and enhancing identification rate and a controller utilizing the method. 2. Brief Description of Related Art The touch pad is a humanized input device in spite of the conventional input devices such as keyboard, mouse and locus ball being unable to satisfy need of the user. Further, a trend of designing electronic products is to pursue lightness, thinness, shortness and smallness so that it is not possible to integrate all kinds of input devices in a single electronic product. Because the touch pad can provide the user a humanized operation with handwriting input and has the function of the conventional input devices at the same time, the touch pad has become the most popular choice. Referring to FIG. 1 , the touch pad 10 can access analog/digital conversion and figure out coordinates of the touch point with a controller 20 after producing analog signals of voltage. Meanwhile, the controller 20 can identify if the user produce a single tap or click, double taps or clicks, a drag or a movement and then sends related control signal to a main unit 30 to control the cursor on a screen 40 of the main unit 30 accessing movements of shifting, selecting an item and executing a program. The analog/digital converter (not shown) in the controller 20 can be interfered by foreign noise such as electromagnetic wave easily so that it is necessary to add proper samples and recognition algorithm in addition to requiring careful layout of internal circuit and increasing various filters for solving the problem. Otherwise, the noise is easy to result in phenomenon of temporary pseudo press or pseudo exit such that the controller 20 erroneously determines the movement. U.S. Pat. No. 6,380,931 discloses an identifying method of single tap with a touch device and a brief summary thereof is described hereinafter. Referring FIG. 2 , firstly, it is to detect if an object such as touch pen contacts the touch device as shown in step 201 and then it is to compare time T of the object with a default value Tmax and check if T is smaller than Tmax as shown in step 202 . Further, it is to make sure if displacement S of the object on the touch device is smaller than a default value Smax as shown in step 203 . In case of meeting the preceding two conditions, determination of single tap movement can be made and a control signal of representing the single tap and information regarding coordinates of position at the spot of clicking can be sent to the main unit. However, the preceding method is not possible to resist noise, which is apt to produce phenomenon of pseudo press. Especially in order to comply with calculation of the two restrictions (contact time and displacement), the set up cost of the logic circuit is expensive too. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, an object of the present invention is to provide a method, which can filter unnecessary noise effectively for enhancing accuracy of identifying a movement of single tap, and a controller thereof. Wherein, the controller, which sends at least a control signal to a main unit corresponding to a movement of at least an object contacting the touch device, comprises a coordinate calculating unit, a detecting contact unit, a counting time unit, an operation unit and an encoding unit. The coordinate calculating unit detects an electronic signal sent by the touch device to figure out a coordinate position of the object contacting the touch device. The detecting contact unit detects the electronic signal sent by the touch device to determine if the object contacts the touch device. The operation unit figures out a first time span of the object contacting the touch device during the object terminating contacting the touch device according to a result of the determination done by the detecting contact unit, controls the counting time unit to start time counting in case of the object contacts the touch device and generates a control signal indicating the single tap in case of the first time span being less than a second time span, the first time span being greater than a preset time span and only one contacting time being greater than the preset time in the second time span. The encoding unit encodes the control signal and the coordinate position and sending the encoded data to the main unit. The method for identifying a movement of single tap according to the present invention is to have detected the movement of the object contacting the touch device initiating time counting and have detected the movement of the object contacting the touch device being terminated and a first time span being obtained. Finally, a control signal indicating the movement of single tap can be obtained in case of the first time span being less than a second time span, the first time span being greater than a preset time span and only one contacting time being greater than the preset time with the second time span. In short, the present invention provides another restriction regarding if the time span of the object contacting the touch device is greater than the first time span and smaller than the second time span in addition to the restriction regarding if only one contact movement in the second time span. Hence, it is capable of resisting noise effectively to enhance accuracy of recognizing movements. Moreover, due to being not necessary to provide a restriction of displacement, it is possible to lower down the set up cost for logic circuit. | 20040212 | 20070220 | 20050818 | 66137.0 | 20 | OSORIO, RICARDO | METHOD FOR IDENTIFYING A MOVEMENT OF SINGLE TAP ON A TOUCH DEVICE | SMALL | 0 | ACCEPTED | 2,004 |
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10,776,692 | ACCEPTED | Method of scrolling window screen by means of controlling electronic device | A method of scrolling a window screen for controlling electronic device provides a first press zone and a second press zone in a touch device of the electronic device. When the first press zone is pressed, the window screen can be controlled to scroll along a first direction and when the second press zone is pressed, the window screen can controlled to scroll along a second direction, which has a direction different from the first direction. Hence, the scrolling of the window screen is capable of being controlled easily by way of clicking the press zones. | 1. A method of scrolling window screen by means of controlling electronic device, which at least has a touch device, comprising following steps: (A) providing “N” press zones, and the “N” being designated as an integer at least 1; and (B) Detecting the “N” press zones and controlling the window screen scrolling along a “J” direction once a “J” press zone has been detected being pressed. 2. The method of scrolling window screen by means of controlling electronic device as defined in claim 1, wherein “J” in step (A) represents an integer between 1 and N and the direction “J” means a direction upward, downward, leftward, rightward or one of any other directions. 3. The method of scrolling window screen by means of controlling electronic device as defined in claim 2, wherein N=2 in step (A) and the touch device is provided with a first press zone and a second press zone and when the first press zone is detected to have been pressed, the window screen is controlled to scroll in a first direction and when the second press zone is detected to have been pressed, the window screen is controlled to scroll in a second direction in step (B). 4. The method of scrolling window screen by means of controlling electronic device as defined in claim 3, wherein the first direction is opposite to the second direction. 5. The method of window screen scrolling for controlling electronic device as defined in claim 4, wherein the first and second directions are moving upward and downward direction respectively. 6. The method of window screen scrolling for controlling electronic device as defined in claim 4, wherein the first and second directions are moving leftward and rightward. 7. The method of window screen scrolling for controlling electronic device as defined in claim 3, wherein the window screen at a lateral side thereof is further provided with a scroll bar and when the first press zone is pressed, the window screen is controlled to scroll in the first direction and when the second press zone is pressed, the window screen is controlled to scroll in the second direction in step (B). 8. The method of scrolling window screen by means of controlling electronic device as defined in claim 3, wherein the first and second press zones further comprises a plurality of speed zones respectively and each of the speed zones is provided with different scrolling speeds in step (A) and when one of the speed zones is pressed, the window screen is controlled to scroll in a direction belonged to a press zone of said speed zone with the scroll speed of said speed zone in step (B). 9. The method of scrolling window screen by means of controlling electronic device as defined in claim 8, wherein the speed zones nearer center of the touch device provide slower scrolling speeds and the speed zones farther from the center of the touch device provide faster scrolling speeds in step (A). 10. The method of scrolling window screen scrolling by means of controlling electronic device as defined in claim 8, wherein the speed zones nearer center of the touch device provide faster scrolling speeds and the speed zones farther from the center of the touch device provide slower scrolling speeds in step (A). 11. The method of scrolling window screen by means of controlling electronic device as defined in claim 8, wherein the scrolling speed of each of the speed zones can be fixed or variable. 12. The method of scrolling window screen by means of controlling electronic device as defined in claim 3, wherein the first press zone further comprises a first normal speed zone and a first fast speed zone and the second press zone further comprises a second normal speed zone and a second fast speed zone; when the first and second normal speed zones are pressed, the window screen is controlled to scroll along the pressed zones of the normal speed zones and when first and second fast speed zones are pressed, the window screen is controlled to scroll along the pressed zones belonged to the fast speed zones with a speed faster than the normal speed in step (A). 13. The method of scrolling window screen by means of controlling electronic device as defined in claim 3, wherein the scrolling speed of the window screen can be regulated based on number of times and duration of the pressing in case of the first press zone or second press zone having been detected being pressed more than once in step (B). 14. The method of scrolling window screen by means of controlling electronic device as defined in claim 13, wherein the pressing means another short tap or another pressing with longer duration having been detected right after at least a short tap having is detected in step (B). 15. The method of scrolling window screen scrolling by means of controlling electronic device as defined in claim 13, wherein the scrolling speed of the window screen is regulated faster based on to both the number of times and duration of the pressing movement in step (B). 16. The method of scrolling window screen by means of controlling electronic device as defined in claim 13, wherein the scrolling speed of the window screen is regulated slower based on both the number of times and duration of the pressing in step (B). 17. The method of scrolling window screen scrolling by means of controlling electronic device as as defined in claim 13, wherein the window screen stops scrolling based on both the number of times and duration of the pressing in step (B). 18. The method of scrolling window screen scrolling by means of controlling electronic device as defined in claim 3, wherein a pressed position of the first press zone or the second zone is detected and the scrolling speed of the window screen is determined according to the pressed position and the pressed position nearer the center of the touch device provides slower scrolling speeds and the pressed position is farther from the center of the touch device provides faster scrolling speeds in step (B). 19. The method of scrolling window screen scrolling by means of controlling electronic device as defined in claim 3, wherein a pressed position of the first press zone or the second zone is detected and the scrolling speed of the window screen is determined based on the pressed position and the pressed position nearer the center of the touch device provides faster scrolling speeds and the pressed position is farther from the center of the touch device provides slower scrolling speeds in step (B). 20. The method of scrolling window screen by means of controlling electronic device as defined in claim 3, wherein the window screen keeps scrolling in case of the first press zone or the second zone having been detected being pressed. 21. The method of window screen scrolling for controlling electronic device as defined in claim 20, wherein the window screen keeps scrolling till the same press zone being pressed again. 22. The method of scrolling window screen by means of controlling electronic device as defined in claim 20, wherein the window screen keeps scrolling till another pressed zone being pressed. 23. The method of window screen scrolling for controlling electronic device as defined in claim 20, wherein the window screen keeps scrolling till an outside area of the pressed zone being pressed. 24. The method of window screen scrolling for controlling electronic device as defined in claim 3, wherein at least a special press zone is provided on the touch device and the scroll bar can be reset in case of the special press zone having been detected being in a state of being pressed in step (A). 25. The method of window screen scrolling for controlling electronic device as defined in claim 3, wherein the scroll bar can be reset in case of a plurality of press zones having been detected being pressed at the same time in step (A). 26. The method of scrolling window screen by means of controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar is returning to a beginning position, a middle position, another default position done by the system or a position set by the user. 27. The method of window screen scrolling for controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means the scrolling speed of the scroll bar is returned to a default state. 28. The method of window screen scrolling for controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means opening or closing scrolling function of the first press zone or the second press zone. controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means changing the scrolling direction of the first press zone and/or the second press zone. 30. The method of scrolling window screen by means of controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means the window screen stopping scrolling. 31. The method of window scrolling screen by means of controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means the last time scrolling is repeated on the window screen and the repeated movement contains direction, speed, and/or distance of the scrolling. 32. The method of scrolling window screen by means of controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means the window screen keeps scrolling with the direction and speed of the last scrolling. 33. The method of scrolling window screen by means of controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means allowing the window screen to page up, page down, scroll upward or scroll downward. 34. The method of scrolling window screen by means of controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means generating electronic signal of single tap or double tap. 35. The method of scrolling window screen by means of controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means generating repeated drag movement for the cursor of the mouse done last time. 36. The method of scrolling window screen by means of controlling electronic device as defined in claim 24 or 25, wherein a state of resetting the scroll bar means generating electronic signal of repeated tap and drag done last time. 37. The method of scrolling window screen by means of controlling electronic device as defined in claim 35, wherein N=4 and the touch device is provided with an upward scroll zone, a downward scroll zone, a leftward scroll zone and rightward scroll zone in step (A) and the window screen is controlled to scroll upward or downward in case of the upward scroll zone or the downward scroll zone having been detected being pressed and the window screen is controlled to scroll leftward or rightward in case of the rightward scroll zone or the leftward scroll zone having been detected being pressed. 38. An electronic device, comprising: at least a screen, displaying at least a window screen; at least a touch device, providing N press zones, the N being an integer of at least 1 and the press zones can be detected; and a processing unit, electrically connecting with the screen and the touch device and controlling the window screen scrolling in a J direction in case of the a J press zone in the N press zones being touched. 39. The electronic device as defined in claim 38, wherein the J represents an integer between 1 and N and the J direction can represent a direction upward, downward, leftward, rightward or any of other arbitrary directions. 40. The electronic device as defined in claim 38, wherein N=2 and the touch device is provided with a first press zone and a second press zone and when the treatment unit has learned the first press zone is pressed, the window screen is controlled to scroll in a first direction and when the treatment has learned the second press zone being pressed, the window screen is controlled to scroll in a second direction, which is different from the first direction. 41. The electronic device as defined in claim 40, wherein the first direction is opposite to the second direction. 42. The electronic device as defined in claim 41, wherein the first direction and the second direction are upward and downward directions respectively. 43. The electronic device as defined in claim 41, wherein the first direction and the second direction are rightward and leftward directions respectively. 44. The electronic device as defined in claim 40, wherein the window screen at a lateral side thereof further provides a scroll bar and when the first press zone is pressed, the processing unit allows the scroll bar moving along the first direction and when the second press zone is pressed, the processing zone allows the scroll bar moving along the second direction. 45. The electronic device as defined in claim 40, wherein the first and second press zone further comprises a plurality of speed zone and each of the speed zone can be provided with different scroll speeds and when one of the speed zones is pressed, the processing unit controls the window screen scrolls along a scroll direction of a press zone belonged to the speed zone with a speed of the speed zone. 46. The electronic device as defined in claim 45, wherein the speed zones nearer to the center of the touch device provide slower scroll speed and farther from the center of the touch device provide faster scroll speed. 47. The electronic device as defined in claim 45, wherein the speed zones nearer to the center of the touch device provide faster scroll speed and farther from the center of the touch device provide slower scroll speed. 48. The electronic device as defined in claim 45, wherein the scroll speed of each of the speed zones can be fixed or variable. 49. The electronic device as defined in claim 40, wherein the first press zone further comprises a first normal speed zone and a first fast speed zone and the second press zone further comprises a second normal speed zones and a second fast speed zone; when the first or second normal speed is pressed, the processing unit controls the window screen scrolls toward a press zone belonged to the normal speed zone with a normal speed and when the first or second fast speed zone is pressed, the processing unit controls the window screen scrolls toward a press zone belonged to the fast speed zone with a speed faster than the normal speed. 50. The electronic device as defined in claim 40, wherein the scrolling speed of the window screen can be regulated based on the number of times and duration of the pressing while the first press zone or second press zone has been detected being pressed more than once. 51. The electronic device as defined in claim 50, wherein the pressing means the touch device detects another short tap right or another longer pressing after at least a short tap being detected. 52. The electronic device as defined in claim 50, wherein the processing unit regulates the scrolling speed of the window screen faster based on the number of times and duration of the pressing. 53. The electronic device as defined in claim 50, wherein the processing unit regulates the scroll speed of the window screen slower based on the number of times and duration of the pressing. 54. The electronic device as defined in claim 50, wherein the processing unit stops scrolling of the window screen based on the number of times and duration of the pressing. 55. The electronic device as defined in claim 50, wherein the touch device detects the pressed position of the first press zone or the second press zone and the processing unit determines the scroll speed of the window screen based on the pressed position and the scroll speed gets slower in case of the pressed position getting nearer the touch device and the scroll speed gets faster in case of the pressed position getting farther from the touch device. 56. The electronic device as defined in claim 50, wherein the touch device detects the pressed position of the first press zone or the second press zone and the processing unit determines the scroll speed of the window screen based on the pressed position and the scroll speed gets faster in case of the pressed position getting farther from the touch device and the scroll speed gets slower in case of the pressed position getting nearer the touch device. 57. The electronic device as defined in claim 50, wherein the processing unit allows the window screen to keep scrolling in case of the touch device having detected the first press zone or the second press zone being pressed. 58. The electronic device as defined in claim 58, wherein the processing unit allows the window screen to keep scrolling till the same press zone being pressed again. 59. The electronic device as defined in claim 57, wherein the processing unit allows the window screen to keep scrolling till another press zone being pressed again. 60. The electronic device as defined in claim 57, wherein the processing unit allows the window screen to keep scrolling till outside area of the press zone being pressed. 61. The electronic device as defined in claim 40, wherein the touch device is further provided at least a special press zone and the processing unit resets the scroll bar in case of the touch device having detected the special press zone being pressed. 62. The electronic device as defined in claim 40, wherein the touch device is further provided at least a special press zone and the processing unit resets the scroll bar in case of the touch device having detected a plurality of press zones being pressed at the same time. 63. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar is returning to a beginning position, a middle position, another default position done by the system or a position set by the user. 64. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means the scrolling speed of the scroll bar is returned to a default state. 65. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means opening or closing scrolling function of the first press zone or the second press zone. 66. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means to change the scrolling direction of the first press zone and/or the second press zone. 67. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means the window screen stop scrolling. 68. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means last time scrolling is repeated on the window screen and the repeated movement contains direction, speed, and/or distance of the scrolling. 69. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means the window screen keeps scrolling along the direction and speed of last scrolling. 70. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means allowing the window screen to page up, page down, scroll upward or scroll downward. 71. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means generating electronic signal of single tap or double tap. 72. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means generating repeated drag movement for the cursor of the mouse done last time. 73. The electronic device as defined in claim 61 or 62, wherein a state of resetting the scroll bar means generating electronic signal of repeated tap and drag done last time. 74. The electronic device as defined in claim 39, wherein N=4 and the touch device is provided with an upward scroll zone, a downward scroll zone, a leftward scroll zone and rightward scroll zone and the processing unit control the window screen to scroll upward or downward in case of the touch device having detected the upward scroll zone or the downward scroll zone being pressed and the processing unit controls the window screen to scroll leftward or rightward in case of the touch device having detected the rightward scroll zone or the leftward scroll zone being pressed. 75. The electronic device as defined in claim 38, wherein the processing unit is loaded with an operation system and application program to form a graphic interface of user with scroll bar. 76. The electronic device as defined in claim 38, wherein the processing unit is further loaded with a driver to detect the pressing of the first and second press zone with the touch device. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of scrolling window screen by way of controlling electronic device, and particularly to a method with which the window screen can be scrolled easily, fast and effortlessly with controlling electronic device. 2. Description of Related Art Graphical User Interface (GUI) is well known to most of the people. One of the main functionalities for the GUI is the ability for the scrolling of the window screen (including up-down scrolling and left-right scrolling) for the easy browsing by a user. Therefore, at the edge of the window (up-down edge or left-right edge), usually situates a graphical control tool called the scroll bar to allow the user to press on with a mouse and drag along the parallel direction of the scroll bar so that the window screen can be scrolled. However, the scroll bar usually just occupies one or two small locations on the screen (up-down scroll bar or left-right scroll bar) and it results in the difficulties and time consuming problem for the user to accurately move the cursor on top of the scroll bar. But, if the size of the scroll bar is increased for solving this problem, effective viewing area of the screen will become sacrificed. Hence, In order to allow operation of the GUI scrolling easier, a scroll wheel is installed on the surface of the mouse for scrolling the window screen without moving the mouse cursor but this requires complicated and expensive mechanical components added to the existing mouse and it is not easy for storing when using it with a portable computer. U.S. Pat. No. 5,943,052 discloses a method for controlling the scroll bar with a scrolling zone, which is disposed on a touch device electrically connected to a computer, allows the user to move up and down (vertical scrolling zone) or left and right (horizontal scrolling zone) on the touch device with a finger so as to perform the up-down scrolling or left-right scrolling of a window screen and achieve an effective way for controlling the scroll bar. However, the method requires the finger to scroll continuously in order to simulate the scrolling of the mouse scroll wheel so that the system has to repetitively detect and determine the movement of the finger in any direction. It not only increases the complexity of the system program but also the user has to continuously exert force on the finger to perform the scrolling on the touch device. In this way, it easily causes fatigue and injury to the finger. SUMMARY OF THE INVENTION As a consequence, the object of the present invention is to provide a convenient method of window screen scrolling for controlling electronic device. Therefore, the method of window screen scrolling for controlling electronic device according to the present invention comprises of the following steps: (A) N scrolling zones are installed on the touch device, where N is an integer equal or greater than 1; (B) detect the N scrolling zones, when the J scrolling zone is being pressed, then the window screen is controlled to scroll in the direction of J. Besides, the electronic device according to the present invention includes at least one monitor, at least one touch device and a processing unit. The monitor is used to display at least one window screen. The touch device has N scrolling zones, where N is an integer equal or greater than 1, and the touch device can perform detection on the N scrolling zones. The processing unit, the monitor and the touch device are all electrically connected and once the J scrolling zone of the N scrolling zones is pressed, the window screen is to scroll in the direction of J. BRIEF DESCRIPTION OF THE DRAWINGS The present invention can be more fully understood by reference to the following description and accompanying drawings, in which: FIG. 1 is a structure diagram of a first preferred embodiment of the present invention; FIG. 2 is a structure diagram of a second preferred embodiment of the present invention; and FIG. 3 is a structure diagram of the second preferred embodiment of the present invention illustrating another example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 which is a structural diagram of the first preferred embodiment of the electronic device according to the present invention, wherein the electronic device 1 include a touch device 2, a processing unit 3 connected electrically to the touch device 2 and a monitor for displaying the window screen 4. In addition, the touch device 2 controls the window screen through the processing unit 3. The processing unit 3 is installed with an operation system 32 and an application program 21, which forms a Graphical User Interface (GUI) including a scroll bar on the window screen 4. The preceding preferred embodiment at the right edge (or the left edge) of the touch device 2 is provided with a first press zone 21, a second press zone 22 and a third press zone 23 (called middle stop zone hereinafter), which is situated between the first and second press zones, and the three press zone are arranged vertically to be adapted to movement (up-down movement) of the scroll bar 41 on the window screen 4 so as to allow the hand and eyes being coordination while the user operates on the press zones. Certainly, as shown in FIG. 1, at the top or bottom edge of the touch device 2, press zones 24˜26 for the left and right scrolling of the window screen 4 can be installed. Besides, the processing unit 3 is installed with an optional driver program 33 which can be used with the touch device 2 to control the scrolling of the scroll bar 41 and allow the user an convenient way to modify the related settings for press zones 21˜23. However, it has to be noted that the touch device 2 itself can have a built-in detection circuit (not shown in the figure) and a scroll bar controlling circuit so the touch device 2 itself can perform the control on the scroll bar without requiring the driver program 33. Therefore, when the touch device 2 with the driver program 33 detecting the first press zone 21 is pressed continuously, it will then continuously produce a first control signal to the processing unit 3 to allow the window frame 4 to maintain its scrolling in the first direction (upward) and at the same time, the scroll bar will follow to move upwards. Similarly, while the touch device 2 has detected the first press zone 22 being pressed continuously, a second control signal is produced continuously and sent to the processing unit 3 so that the window screen 4 can maintain scrolling in the second direction (downward) opposite to the first direction (upward) and at the same time, the scroll bar will follow to move downwards. Furthermore, while the touch device 2 has detected the middle stop zone 23 being pressed or both the first press zone 21 and the second press zone 22 being not pressed, the window screen 4 stops scrolling immediately. Therefore, from the above explanation, it can be understood that the first embodiment of the present invention allows the user to use the finger to touch any of the press zone 21˜23 on the touch device 2 without moving the finger and the up-down scrolling or stop scrolling of the window screen 4 can be controlled. Something worth noting is that, in the above mentioned embodiment of the present invention, the middle stop zone 23 is not necessarily required and the touch device 2 can decide the scrolling or stopping of the window screen by determining if the finger presses on or releases from the press zone 21˜23. Additionally, in the embodiment of the present invention, a special press zone 27 can be further installed on the touch device 2. When the touch device 2 has detected the special press zone 27 being pressed, then immediately the processing unit 3 resets the status of the scrolling bar, wherein the mentioned resetting the status of the scrolling bar can be any of the following actions: (1) Restore the scroll bar 41 to its starting position, middle position, finish position, any other position pre-defined by the system, or custom position set by the user. (2) Restore the scrolling speed of the scroll bar back to default. (3) Enable or disable the first press zone/or the second press zone's scrolling abilities. (4) Change the scrolling direction of the first press zone/or the second press zone. (5) Stop the scrolling of the window screen. (6) Repeat the previous scrolling action on the window screen, wherein the repeated action includes scrolling direction, speed, and/or scrolling distance. (7) Maintain the scrolling of the window screen according to the direction and speed of the previous scrolling action. (8) Move the window screen one page up, one page down, scroll upwards or scroll downwards. (9) Generate electrical signal for the single or double clicking action. (10) Generate electrical signal for the previous mouse drag action. (11) Generate electrical signal for the previous click and drag action. Besides, the action for the above mentioned resetting scroll bar's setting status can be started when the touch device 2 has detected multiple press zones being pressed simultaneously. Moreover, aside from the above mentioned detection method, the touch device 2 can detect the continuous and short pressing action (or clicking) on the first press zone 21 or the second press zone 22 to allow the processing unit 3 to be based on the number of continuous clicking of the first press zone 21 or the second press zone 22 to correspondingly adjust the scrolling speed of the window screen 4. For example, when the touch device 2 has detected the first press zone 21 having been clicked, it will start counting the number of clicks within a fixed time after the first click, and based on the number of clicks generate a control signal to the processing unit 3, in order to adjust the corresponding scrolling speed of the window screen 4 in the first direction. For instance, when clicking once, it will make the window screen 4 to scroll at normal speed, continuous clicking twice will make the window frame 4 to scroll at two times the normal speed, while clicking three times, it will make the window screen 4 to scroll at three times the normal speed. Similarly, when the second press zone 22 is pressed, the window screen 4 will scroll towards a direction that is opposite to the first direction and the speed will be adjusted according to the number of clicks on the second press zone 22. Therefore, the user can be based on his preference to use the finger clicking continuously multiple times on the first press zone 21 or the second press zone 22 so as to control the scrolling speed of the window screen 4 and thus the finger does not have to move on the touch device 2. In addition, the touch device 2 can also detect the time duration when the first press zone or the second press zone is pressed to allow the processing unit 3 based on this time duration to correspondingly adjust the scrolling speed of the window screen 4. For example, the longer the pressing duration, the faster the scrolling speed while the shorter the pressing duration, the slower the scrolling time. Likewise, the touch device 2 can detect the position of the pressing on the first press zone 21 or the second press zone 22 to allow the processing unit 3 based on the position to correspondingly adjust the scrolling speed of the window screen 4. For example, the closer the pressing position closer to the center of the touch device 2 (which is the third press zone 23), the slower the scrolling speed while the further the pressing position from the center of the touch device 2, the faster the scrolling time. In addition, when the touch device 2 has detected the first press zone 21 or the second press zone 22 being pressed, it will allow the processing unit 3 to control the window frame 4 to maintain its scrolling until the same press zone is pressed again to stop scrolling and by the toggling on/off to control if the window screen 4 will scroll or not. Certainly, the processing unit 3 can control the window screen 4 to maintain scrolling until the other press zone is pressed to stop scrolling or control the window screen 4 to maintain scrolling until the area outside the press zone is pressed again to stop scrolling. Furthermore, in reality, when the user presses the first press zone 21 or the second press zone 22, the touch device 2 will send out a first scrolling instruction to allow the processing unit 3 controlling the window screen 4 scrolling once right after the pressing. And after a short period of time, continue to send out the second scrolling instruction to allow the processing unit 3 to maintain the continuous scrolling of the window screen 4. The time span between the first and second scrolling instructions can be set as equal, shorter or longer than the time after the continuous instructions are set. Subsequently, referring to FIG. 2 which shows the second preferred embodiment according to the present invention and it differs from the first preferred embodiment in that on the touch device 5, at the location of the first press zone 21 in the first embodiment, is installed a first normal speed zone (the upward normal speed zone) 51 and the first faster speed zone (the upward faster speed zone) 52, and at the location of the second press zone 22 in the first embodiment, is installed a second normal speed zone (the downward normal speed zone) 53 and a second faster speed zone (the downward faster speed zone) 54, and a middle stop zone 55 between the upward normal speed zone and the downward normal speed zone. Therefore, when the touch device 5 has detected the upward normal speed zone 51 or the upward faster speed zone 52 having been pressed, through the processing unit 3, it controls the window screen 4 to scroll upward at normal speed or a faster speed. Similarly, when the touch device 5 has detected the downward normal speed zone 53 or the downward faster speed zone 54 having been pressed, through the processing unit 3, it controls the window screen 4 to scroll downward at normal speed or a faster speed. The above mentioned window screen 4 will stop its scrolling when the touch device 5 has detected the middle stop zone 55 being pressed or the press zones 51-54 having not been pressed. From the above mentioned explanations, in the second preferred embodiment according to the present invention, the user just needs to touch the press zones 51-54 for decide the scrolling speed of the window screen 4 and the finger does not has to be moved. Definitely, in the second embodiment of the present invention, the middle stop zone 55 is not necessarily required and the touch device 5 can determine whether the finger presses or leaves the press zone 51-55 to control the window screen 4 to scroll or stop. Certainly, referring to FIG. 3, in the third preferred embodiment according to the present invention, the touch device 6 can install at the location of the first press zone 21 (the upward press zone 61) and the second press zone 22 (the downward press zone 62) of the first embodiment according to the present invention, respectively more than two speed zones and each of the speed zones is given a different scrolling speed. When the touch device 6 has detected one of the speed zone being pressed, the processing unit 3 is instructed to control the window screen 4 to scroll towards the direction of the speed zone with the pre-defined speed of that zone. Furthermore, when the speed zone located closer to the center of the touch device 6 (the middle stop zone 55), it will have slower scrolling speed. While the speed zones are further away from the center of the touch device 6 (the middle stop zone 55), it will have faster scrolling speed. Moreover, the scrolling speed given to each of the speed zones can be fixed or kept changing to faster speed in an accelerated way. Summarizing all the description above, installing multiple press zones 21˜23 (51˜55, 61˜62) and simulating the actual pressing of the real body on the touch device 2 (5, 6) allow the user by using his finger to touch the press zone and not moving it on the touch device for controlling the scrolling or stopping of the window screen 4. This not only greatly increases the convenience of the operation but also allows the user's finger not to continuously perform scrolling movement for simulating the scrolling of the mouse scroll wheel. Hence, the fatigue and risk of injury that may be caused to the finger can be reduced. Moreover, the detection procedure is further simplified to reduce the complexity of the system programs and circuits. While the invention has been described with reference to the preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a method of scrolling window screen by way of controlling electronic device, and particularly to a method with which the window screen can be scrolled easily, fast and effortlessly with controlling electronic device. 2. Description of Related Art Graphical User Interface (GUI) is well known to most of the people. One of the main functionalities for the GUI is the ability for the scrolling of the window screen (including up-down scrolling and left-right scrolling) for the easy browsing by a user. Therefore, at the edge of the window (up-down edge or left-right edge), usually situates a graphical control tool called the scroll bar to allow the user to press on with a mouse and drag along the parallel direction of the scroll bar so that the window screen can be scrolled. However, the scroll bar usually just occupies one or two small locations on the screen (up-down scroll bar or left-right scroll bar) and it results in the difficulties and time consuming problem for the user to accurately move the cursor on top of the scroll bar. But, if the size of the scroll bar is increased for solving this problem, effective viewing area of the screen will become sacrificed. Hence, In order to allow operation of the GUI scrolling easier, a scroll wheel is installed on the surface of the mouse for scrolling the window screen without moving the mouse cursor but this requires complicated and expensive mechanical components added to the existing mouse and it is not easy for storing when using it with a portable computer. U.S. Pat. No. 5,943,052 discloses a method for controlling the scroll bar with a scrolling zone, which is disposed on a touch device electrically connected to a computer, allows the user to move up and down (vertical scrolling zone) or left and right (horizontal scrolling zone) on the touch device with a finger so as to perform the up-down scrolling or left-right scrolling of a window screen and achieve an effective way for controlling the scroll bar. However, the method requires the finger to scroll continuously in order to simulate the scrolling of the mouse scroll wheel so that the system has to repetitively detect and determine the movement of the finger in any direction. It not only increases the complexity of the system program but also the user has to continuously exert force on the finger to perform the scrolling on the touch device. In this way, it easily causes fatigue and injury to the finger. | <SOH> SUMMARY OF THE INVENTION <EOH>As a consequence, the object of the present invention is to provide a convenient method of window screen scrolling for controlling electronic device. Therefore, the method of window screen scrolling for controlling electronic device according to the present invention comprises of the following steps: (A) N scrolling zones are installed on the touch device, where N is an integer equal or greater than 1; (B) detect the N scrolling zones, when the J scrolling zone is being pressed, then the window screen is controlled to scroll in the direction of J. Besides, the electronic device according to the present invention includes at least one monitor, at least one touch device and a processing unit. The monitor is used to display at least one window screen. The touch device has N scrolling zones, where N is an integer equal or greater than 1, and the touch device can perform detection on the N scrolling zones. The processing unit, the monitor and the touch device are all electrically connected and once the J scrolling zone of the N scrolling zones is pressed, the window screen is to scroll in the direction of J. | 20040212 | 20080115 | 20050908 | 63595.0 | 14 | SHAPIRO, LEONID | METHOD OF SCROLLING WINDOW SCREEN BY MEANS OF CONTROLLING ELECTRONIC DEVICE | SMALL | 0 | ACCEPTED | 2,004 |
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10,776,761 | ACCEPTED | Process for production of high-isoprene butyl rubber | The present invention relates to a continuous process for producing polymers at conversions ranging from 50% to 95% having a Mooney viscosity of at least 25 Mooney-units and a gel content of less than 15 wt. % containing repeating units derived from at least one isoolefin monomer, more than 4.1 mol % of repeating units derived from at least one multiolefin monomer and optionally further copolymerizable monomers in the presence of AlCl3 and a suitable proton source (e.g. water) or cationogen and at least one multiolefin cross-linking agent wherein the process is conducted in the absence of transition metal compounds and organic nitro compounds. | 1. A process for the production of a polymer(s) having a Mooney viscosity of at least 25 Mooney-units and a gel content of less than 15 wt. % comprising repeating units derived from at least one isoolefin monomer, more than 4.1 mol % of repeating units derived from at least one multiolefin monomer comprising mixing at least isoolefin monomers, at least one multiolefin monomer and optionally further copolymerizable monomers in the presence of AlCl3 and at least one proton source and/or cationogen capable of initiating the polymerization process and at least one multiolefin cross-linking agent, wherein the process is conducted in the absence of transition metal compounds and organic nitro compounds, wherein the process is continuous, and wherein the conversion level of the polymer is between 50% and 95%. 2. A process according to claim 1, wherein the polymer is produced at conversion levels ranging from 60% to 95 and contains greater than 5 mol % of repeat units derived from a multiolefin and a gel content of less than 10 wt. %. 3. A process according to claim 1, wherein the polymer is produced at conversion levels ranging from 75% to 95 and contains greater than 7 mol % of repeat units derived from a multiolefin and a gel content of less than 5 wt. %. 4. A process according to claim 1, wherein said isoolefin monomer is isobutene. 5. A process according to claim 1, wherein the process is conducted in at least one continuous reactor having a volume between 0.1 m3 and 100 m3. 6. A process according to claim 1, wherein the process is conducted in a continuous reactor having a volume between 1 m3 and 10 m3. 7. A process according to claim 1, wherein the multiolefin is isoprene. 8. A process according to claim 1, wherein said multiolefin crosslinking agent is divinylbenzene. 9. A polymer having a Mooney viscosity of at least 30 Mooney-units and a gel content of less than 15 wt. % comprising repeating units derived from at least one isoolefin monomer, more than 4.1 mol % of repeating units derived from at least one multiolefin monomer and optionally further copolymerizable monomers, wherein the polymer does not contain any transition metal catalyst residues or organic nitro compounds residues. 10. A polymer according to claim 9 which has been either partially or completely chlorinated. 11. A polymer according to claim 9 which has been either partially or completely brominated. 12. A polymer according to claim 10 which has been maleated. 13. A polymer according to claim 11, which has been maleated. 14. A polymer according to claim 10 which has been functionalized with nucleophilic species selected from the group consisting of NR3, −OR, −SR, PR3, −OPR3, −OSiR3, —CR3, —O2CR where R=H, F, Cl, Br, I, CxH2CH3 (x=0 to 20), phenyl, any aromatic derivative, or cyclohexyl group. 15. A polymer according to claim 11 which has been functionalized with nucleophilic species selected from the group consisting of NR3, −OR, −SR, PR3, −OPR3, −OSiR3, —CR3, —O2CR where R=H, F, Cl, Br, I, CxH2CH3 (x=0 to 20), phenyl, any aromatic derivative, or cyclohexyl group. | FIELD OF THE INVENTION The present invention relates to a continuous process for producing polymers at conversions ranging from 50% to 95% with a Mooney viscosity of at least 25 Mooney-units and a gel content of less than 15 wt. % containing repeating units derived from at least one isoolefin monomer, more than 4.1 mol % of repeating units derived from at least one multiolefin monomer and optionally further copolymerizable monomers in the presence of AlCl3 and a suitable proton source (e.g. water) or cationogen and at least one multiolefin cross-linking agent wherein the process is conducted in the absence of transition metal compounds and organic nitro compounds. BACKGROUND OF THE INVENTION Butyl rubber is understood to be a copolymer of an isoolefin and one or more, preferably conjugated, multiolefins as comonomers. Commercial butyl comprises a major portion of isoolefin and a minor amount, not more than 2.5 mol %, of a conjugated multiolefin. Halogenated butyls are also well known in the art, and possess outstanding properties such as oil and ozone resistance and improved impermeability to air. Commercial halobutyl rubber is a halogenated copolymer of isobutylene and up to about 2.5 mol % of isoprene. Butyl rubber or butyl polymer is generally prepared in a slurry process using methyl chloride as a vehicle and a Friedel-Crafts catalyst as part of the polymerization initiator. The use of methyl chloride is advantageous because AlCl3, a relatively inexpensive Friedel-Crafts catalyst, is soluble in methyl chloride, as are the isobutylene and isoprene comonomers. Additionally, the butyl rubber polymer is insoluble in the methyl chloride and precipitates out of solution as fine particles. The polymerization is generally carried out at temperatures of about −90° C. to −100° C. See U.S. Pat. No. 2,356,128 and Ullmanns Encyclopedia of Industrial Chemistry, volume A 23, 1993, pages 288-295. Low polymerization temperatures are required in order to achieve molecular weights which are sufficiently high for rubber applications. Raising the reaction temperature or increasing the quantity of isoprene in the monomer feed results in poorer product properties, in particular, in lower molecular weights. However, a higher degree of unsaturation would be desirable for more efficient crosslinking with other, highly unsaturated diene rubbers (BR, NR or SBR). The molecular weight depressing effect of diene comonomers may, in principle, be offset by lower reaction temperatures. However, in this case the secondary reactions, which result in gelation, occur to a greater extent and these processes are more costly. Gelation at reaction temperatures of around −120° C. and possible options for the reduction thereof have been described (cf. W. A. Thaler, D. J. Buckley Sr., Meeting of the Rubber Division, ACS, Cleveland, Ohio, May 6-9, 1975, published in Rubber Chemistry & Technology 49, 960-966 (1976)). The auxiliary solvents such as CS2 required for this purpose are not only difficult to handle, but must also be used at relatively high concentrations. A further disadvantage associated with the use of CS2 lies in the fact that polymerization reactions of this type are homogeneous in nature. Consequently, there are significant increases in solution viscosity as the polymerization reaction proceeds. This in turn necessitates carrying out these polymerizations to lower conversions (i.e. lower amounts of polymer per unit volume of solvent and therefore a cost disadvantage) as high solution viscosities give rise to heat transfer problems. It is furthermore known to perform gel-free copolymerization of isobutene with various comonomers to yield products of a sufficiently high molecular weight for rubber applications at temperatures of around −40° C. using pretreated vanadium tetrachloride (EP-A1-818 476), a combination of nitro compounds and vanadium (EP-A-1 122 267) or zirconium compounds (WO-02/18460-A1) and others. The present invention operates in the absence of vanadium-, zirconium- and/or hafnium compounds. SUMMARY OF THE INVENTION The present invention provides a continuous process for producing polymers having a Mooney viscosity of at least 25 Mooney-units and a gel content of less than 15 wt. % containing repeating units derived from at least one isoolefin monomer, more than 4.1 mol % of repeating units derived from at least one multiolefin monomer and optionally further copolymerizable monomers in the presence of AlCl3 and a proton source and/or cationogen capable of initiating the polymerization process and at least one multiolefin cross-linking agent wherein the process is conducted in the absence of transition metal compounds. The present invention also provides a continuous slurry process for producing polymers having a Mooney viscosity of at least 25 Mooney-units and a gel content of less than 15 wt. % comprising repeating units derived from isobutene monomer, more than 4.1 mol % of repeating units derived from isoprene monomer and optionally further copolymerizable monomers in the presence of AlCl3 and a proton source and/or cationogen capable of initiating the polymerization process and at least one multiolefin cross-linking agent wherein the process is conducted in the absence of transition metal compounds and organic nitro compounds. DETAILED DESCRIPTION OF THE INVENTION The Mooney viscosity of the polymer is determined using ASTM test D1646 using a large rotor at 125° C., a preheat phase of 1 min, and an analysis phase of 8 min (ML1+8 @ 125° C.) The present invention is not limited to a special isoolefin. However, isoolefins within the range of from 4 to 16 carbon atoms, preferably 4-7 carbon atoms, such as isobutene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, 4-methyl-1-pentene and mixtures thereof are preferred. More preferred is isobutene. The present invention is not limited to a special multiolefin. Every multiolefin copolymerizable with the isoolefin known by the skilled in the art can be used. However, multiolefins with in the range of from 4-14 carbon atoms, such as isoprene, butadiene, 2-methylbutadiene, 2,4-dimethylbutadiene, piperyline, 3-methyl-1,3-pentadiene, 2,4-hexadiene, 2-neopentylbutadiene, 2-methly-1,5-hexadiene, 2,5-dimethly-2,4-hexadiene, 2-methyl-1,4-pentadiene, 2-methyl-1,6-heptadiene, cyclopenta-diene, methylcyclopentadiene, cyclohexadiene, 1-vinyl-cyclohexadiene and mixtures thereof, preferably conjugated dienes, are used. Isoprene is more preferably used. In the present invention, β-pinene can also be used as a co-monomer for the isoolefin. As optional monomers every monomer copolymerizable with the isoolefins and/or dienes known by the skilled in the art can be used. α-methyl styrene, p-methyl styrene, chlorostyrene, cyclopentadiene and methylcyclopentadiene are preferably used. Indene and other styrene derivatives may also be used in the present invention. The multiolefin content is at least greater than 4.1 mol %, more preferably greater than 5.0 mol %, even more preferably greater than 6.0 mol %, most preferably greater than 7.0 mol %. Preferably, the monomer mixture contains in the range of from 80% to 95% by weight of at least one isoolefin monomer and in the range of from 4.0% to 20% by weight of at least one multiolefin monomer including β-pinene and in the range of from 0.01% to 1% by weight of at least one multiolefin cross-linking agent. More preferably, the monomer mixture contains in the range of from 83% to 94% by weight of at least one isoolefin monomer and in the range of from 5.0% to 17% by weight of a multiolefin monomer or β-pinene and in the range of from 0.01% to 1% by weight of at least one multiolefin cross-linking agent. Most preferably, the monomer mixture contains in the range of from 85% to 93% by weight of at least one isoolefin monomer and in the range of from 6.0% to 15% by weight of at least one multiolefin monomer, including β-pinene and in the range of from 0.01% to 1% by weight of at least one multiolefin cross-linking agent. The weight average molecular weight, Mw, is preferably greater than 240 kg/mol, more preferably greater than 300 kg/mol, even more preferably greater than 500 kg/mol, most preferably greater than 600 kg/mol. In connection with the present invention the term “gel” is understood to denote a fraction of the polymer insoluble for 60 min in cyclohexane boiling under reflux. The gel content is preferably less than 10 wt. %, more preferably less than 5 wt %, even more preferably less than 3 wt %, most preferably less than 1 wt %. The polymerization is performed in the presence of AlCl3 and a proton source and/or cationogen capable of initiating the polymerization process. A proton source according to the present invention includes any compound that will produce a proton when added to AlCl3 or a composition containing AlCl3. Protons may be generated from the reaction of AlCl3 with proton sources such as water, alcohol or phenol to produce the proton and the corresponding by-product. Such reaction may be preferred in the event that the reaction of the proton source is faster with the protonated additive as compared with its reaction with the monomers. Other proton generating reactants include thiols, carboxylic acids, and the like. According to the present invention, when low molecular weight polymer product is desired an aliphatic or aromatic alcohol is preferred. The most preferred proton source is water. The preferred ratio of AlCl3 to water is between 5:1 to 100:1 by weight. It may be advantageous to further introduce AlCl3 derivable catalyst systems, diethylaluminium chloride, ethylaluminium chloride, titanium tetrachloride, stannous tetrachloride, boron trifluoride, boron trichloride, or methylalumoxane. In addition or instead of a proton source a cationogen capable of initiating the polymerization process can be used. A cationogen according to the present invention includes any compound that generates a carbo-cation under the conditions present. A preferred group of cationogens include-carbocationic compounds having the formula: wherein R1, R2 and R3, are independently hydrogen, or a linear, branched or cyclic aromatic or aliphatic group, with the proviso that only one of R1, R2 and R3 may be hydrogen. Preferably, R1, R2 and R3, are independently a C1 to C20 aromatic or aliphatic group. Non-limiting examples of suitable aromatic groups may be selected from phenyl, tolyl, xylyl and biphenyl. Non-limiting examples of suitable aliphatic groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, nonyl, decyl, dodecyl, 3-methylpentyl and 3,5,5-trimethylhexyl. Another preferred group of cationogens includes substituted silylium cationic compounds having the formula: wherein R1, R2 and R3, are independently hydrogen, or a linear, branched or cyclic aromatic or aliphatic group, with the proviso that only one of R1, R2 and R3 may be hydrogen. Preferably, none of R1, R2 and R3 are H. Preferably, R1, R2 and R3 are, independently, a C1 to C20 aromatic or aliphatic group. More preferably, R1, R2 and R3 are independently a C1 to C8 alkyl group. Examples of useful aromatic groups may be selected from phenyl, tolyl, xylyl and biphenyl. Non-limiting examples of useful aliphatic groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, nonyl, decyl, dodecyl, 3-methylpentyl and 3,5,5-trimethylhexyl. A preferred group of reactive substituted silylium cations include trimethylsilylium, triethylsilylium and benzyldimethylsilylium. Such cations may be prepared, for example, by the exchange of the hydride group of the R1R2R3Si—H with a non-coordinating anion (NCA), such as Ph3C+B(pfp)4− yielding compositions such as R1R2R3SiB(pfp)4 which in the appropriate solvent obtain the cation. According to the present invention, Ab− denotes an anion. Preferred anions include those containing a single coordination complex possessing a charge bearing metal or metalloid core which is negatively charged to the extent necessary to balance the charge on the active catalyst species which may be formed when the two components are combined. More preferably Ab− corresponds to a compound with the general formula [MQ4]− wherein M is a boron, aluminum, gallium or indium in the +3 formal oxidation state; and Q is independently selected from hydride, dialkylamido, halide, hydrocarbyl, hydrocarbyloxide, halo-substituted hydrocarbyl, halo-substituted hydrocarbyloxide, and halo-substituted silylhydrocarbyl radicals. Preferably, there are no organic nitro compounds or transition metals used in the process according to the present invention. The reaction mixture used to produce the present butyl polymer further contains a multiolefin cross-linking agent. The term cross-linking agent is known to those skilled in the art and is understood to denote a compound that causes chemical cross-linking between the polymer chains in opposition to a monomer that will add to the chain. Some easy preliminary tests will reveal if a compound will act as a monomer or a cross-linking agent. The choice of the cross-linking agent is not restricted. Preferably, the cross-linking contains a multiolefinic hydrocarbon compound. Examples of these include norbornadiene, 2-isopropenylnorbornene, 2-vinyl-norbornene, 1,3,5-hexatriene, 2-phenyl-1,3-butadiene, divinylbenzene, diisopropenylbenzene, divinyltoluene, divinylxylene and C1 to C20 alkyl-substituted derivatives thereof. More preferably, the multiolefin crosslinking agent is divinyl-benzene, diisopropenylbenzene, divinyltoluene, divinyl-xylene and C1 to C20 alkyl substituted derivatives thereof, and or mixtures of the compounds given. Most preferably the multiolefin crosslinking agent contains divinylbenzene and diisopropenylbenzene. The polymerization can be performed in a continuous process in slurry (suspension), in a suitable diluent, such as chloroalkanes as described in U.S. Pat. No. 5,417,930. The monomers are generally polymerized cationically, preferably at temperatures in the range from −120° C. to +20° C., preferably in the range from −100° C. to −20° C., and pressures in the range from 0.1 to 4 bar. The use of a continuous reactor as opposed to a batch reactor seems to have a positive effect on the process. Preferably, the process is conducted in at least one continuous reactor having a volume of between 0.1 m3 and 100 m3, more preferable between 1 m3 and 10 m3. Inert solvents or diluents known to the person skilled in the art for butyl polymerization may be considered as the solvents or diluents (reaction medium). These include alkanes, chloroalkanes, cycloalkanes or aromatics, which are frequently also mono- or polysubstituted with halogens. Hexane/chloroalkane mixtures, methyl chloride, dichloromethane or the mixtures thereof may be preferred. Chloroalkanes are preferably used in the process according to the present invention. Polymerization is preferably performed continuously. The process is preferably performed with the following three feed streams: I) solvent/diluent+isoolefin (preferably isobutene)+multiolefin (preferably diene, isoprene) II) initiator system III) multiolefin cross-linking agent It should be noted that the multiolefin crosslinking agent can also be added in the same feed stream as the isoolefin and multiolefin. Using the process according to the present invention, it is possible to produce novel transition metal-free polymers having a Mooney viscosity of at least 25 Mooney-units and a gel content of less than 15 wt. % containing repeating units derived from at least one isoolefin monomer, more than 4.1 mol % of repeating units derived from at least one multiolefin monomer and optionally further copolymerizable monomers in the presence of AlCl3 and a proton source and/or cationogen capable of initiating the polymerization process and at least one multiolefin cross-linking agent having elevated double bond contents and simultaneously low gel contents. The double bond content may be determined by proton magnetic resonance spectroscopy. These polymers may be the starting material for a halogenation process in order to produce halo-butyl polymers. Preferred are partially or fully chlorinated or brominated polymers having a Mooney viscosity of at least 30 Mooney-units and a gel content of less than 15 wt. % containing repeating units derived from at least one isoolefin monomer, more than 4.1 mol % of repeating units derived from at least one multiolefin monomer and optionally further copolymerizable monomers wherein the polymer does not contain any transition metal catalyst residues or organic nitro compounds residues. Bromination or chlorination can be performed according to the procedures described in Rubber Technology, 3rd Ed., Edited by Maurice Morton, Kluwer Academic Publishers, pp. 297-300 and references cited within this reference. The copolymers presented in the present invention are suitable for the production of moldings of all kinds, in particular tire components and industrial rubber articles, such as bungs, damping elements, profiles, films, coatings. The polymers are used to this end in pure form or as a mixture with other rubbers, such as NR, BR, HNBR, NBR, SBR, EPDM or fluororubbers. The preparation of these compounds is known to those skilled in the art. In most cases carbon black is added as filler and a sulfur based curing system is used. For the compounding and vulcanization it is referred to Encyclopedia of Polymer Science and Engineering, Vol. 4, S. 66 et seq. (Compounding) and Vol. 17, S. 666 et seq. (Vulcanization). The vulcanization of the compounds is usually effected at temperatures in the range of 100 to 200° C., preferred 130 to 180° C. (optionally under pressure in the range of 10 to 200 bar). The following Examples are provided to illustrate the present invention: EXAMPLES Equipment Polymer unsaturation was determined through 1H NMR spectroscopy with the use of a Bruker 1H NMR spectra were obtained on a Bruker 500 MHz NMR Spectrometer. NMR samples used to determine isoprene content were prepared in CDCl3. NMR samples used to determine DVB content were prepared in THF-d8. Microstructure information was calculated with the use of previously established integration methods. Peak shifts were referenced to a TMS internal standard. GPC analysis was performed with the use of a Waters Alliance 2690 Separations Module and Viscotek Model 300 Triple Detector Array. GPC samples were prepared by dissolution in THF. Polymer gel content was determined through conventional gravimetric analysis of the dry, hydrocarbon-insoluble fraction (insoluble in boiling cyclohexane, under agitation for a period of 60 minutes). Chemicals Isobutene was purified to a level which, to those skilled in the art, is amiable to the production of butyl rubber. Isoprene was obtained from Exxon Chemical Co and used as received. Isoprene dimer levels were found to be ca. 200 ppm. Methyl chloride was obtained from Dow Chemical Co. and was dried with the used of deactivated alumina gel prior to use. DVB (64% pure divinyl-benzene, Dow Chemical Co.) was used. The composition and purity of this DVB was verified by GC analysis. According to the analysis, this material was found to contain 45 wt % m-divinylbenzene (m-DVB), 19.5 wt % p-divinyl-benzene (p-DVB), 24 wt % m-ethylvinylbenzene and 11.5 wt % p-ethylvinylbenzene. Example 1 The following example illustrates the production of, via a continuous process, a novel grade of IIR possessing an isoprene content of up to 5.0 mol % and Mooney viscosity (ML 1+8 @ 125° C.) between 35 and 40 MU. The monomer feed composition contained 2.55 wt. % of isoprene (IP or IC5) and 27.5 wt. % of isobutene (IP or IC4). This mixed feed was introduced into the continuous polymerization reactor at a rate of 5900 kg/hour. In addition, DVB was introduced into the reactor at a rate of 5.4 to 6 kg/hour. Polymerization was initiated via the introduction of an AlCl3/MeCl solution (0.23 wt. % of AlCl3 in MeCl) at a rate of 204 to 227 kg/hour. The internal temperature of the continuous reaction was maintained between −95 and −100° C. through the use of an evaporative cooling process. Following sufficient residence within the reactor, the newly formed polymer crumb was separated from the MeCl diluent with the use of an aqueous flash tank. At this point, ca. 1 wt. % of stearic acid was introduced into the polymer crumb. Prior to drying, 0.1 wt. % of Irganox® 1010 was added to the polymer. Drying of the resulting material was accomplished with the use of a conveyor oven. Table 1 details the characteristics of the final material. Example 2 The following example illustrates the production of, via a continuous process, a novel grade of IIR possessing an isoprene content of up to 8.0 mol % and Mooney viscosity (ML 1+8 @ 125° C.) between 35 and 40 MU. The monomer feed composition was comprised of 4.40 wt. % of isoprene (IP or IC5) and 25.7 wt. % of isobutene (IP or IC4). This mixed feed was introduced into the continuous polymerization reactor at a rate of 5900 kg/hour. In addition, DVB was introduced into the reactor at a rate of 5.4 to 6 kg/hour. Polymerization was initiated via the introduction of an AlCl3/MeCl solution (0.23 wt. % of AlCl3 in MeCl) at a rate of 204 to 227 kg/hour. The internal temperature of the continuous reaction was maintained between −95 and −100° C. through the use of an evaporative cooling process. Following sufficient residence within the reactor, the newly formed polymer crumb was separated from the MeCl diluent with the use of an aqueous flash tank. At this point, ca. 1 wt. % of Stearic acid was introduced into the polymer crumb. Prior to drying, 0.1 wt. % of Irganox® 1010 was added to the polymer. Drying of the resulting material was accomplished with the use of a conveyor oven. Table 2 details the characteristics of the final material. Example 3 This comparative example illustrates the production of IIR with a total isoprene level of 7.26 mol % via a batch polymerization process. The catalyst solution was prepared by dissolving anhydrous AlCl3 (1.739 g, 13 mmol, Aldrich 99.99%) in methyl chloride (400 mL) at −30° C., this solution was stirred for 30 minutes prior to being cooled to −95° C. To a 2 L Morton-style reaction vessel cooled to −95° C. and equipped with a over-head stirrer and T-type thermocouple was added methyl chloride (900 mL), isobutene (85.8 g condensed at −95° C.), isoprene (12.3 g) and DVB (0.565 g). A catalyst solution (50 mL) was added to the mixture in a single portion to initiate polymerization. The reaction was allowed to proceed for 10 minutes at which point 10 mL of EtOH/NaOH was added to terminate the reaction followed by 1 phr Irganox 1076. The resultant slurry was allowed to warm to room temperature, during this time the methyl chloride and remaining monomers evaporated and hexanes was added to dissolve the polymer. The polymer was recovered from the hexanes cement by steam coagulation then dried on a 2-roll mill at 135° C. Table 3 details the characteristics of the final material. Example 4 This comparative example illustrates the production of IIR with a total isoprene level of 7.00 mol % via a batch polymerization process in which no crosslinking agent (e.g. DVB) is present. The catalyst solution was prepared by dissolving anhydrous AlCl3 (0.3 g, Aldrich 99.99%) in methyl chloride (200 mL) at −30° C., this solution was stirred for 30 minutes prior to being cooled to −95° C. To a 2 L Morton-style reaction vessel cooled to −95° C. and equipped with a over-head stirrer and T-type thermocouple was added methyl chloride (900 mL), isobutene (11.82 g condensed at −95° C.), and isoprene (2.04 g). A catalyst solution (22 mL) was added to this mixture in a single portion to initiate polymerization. The reaction was allowed to proceed for 10 minutes at which point 10 mL of EtOH/NaOH was added to terminate the reaction followed by 1 phr Irganox 1076. The resultant slurry was allowed to warm to room temperature, during this time the methyl chloride and remaining monomers evaporated and hexanes was added to dissolve the polymer. The polymer was recovered from the hexanes cement by steam coagulation then dried on a 2-roll mill at 135° C. Table 4 details the characteristics of the final material. From these examples it can be seen that the preparation of IIR with elevated levels of IP (IC5) and acceptable Mooney viscosities (35-40 MU) can be successfully prepared in a AlCl3/H2O initiated continuous polymerization process in the presence of DVB (Examples 1 & 2). Although it is possible to prepare IIR with an isoprene content of 7.26 mol in a batch process (with DVB), it is apparent from the data presented in Example 3, that such a material possesses a significantly lower Mooney viscosity, Mw, and Mz and is produced at reduced conversions. Similarly, when such a material is produced in the absence of DVB (Example 4), a further reduction in the Mooney and Mw is observed. TABLE 1 Isoprene Content (mol %) 4.5-5.0 DVB Content (mol %) 0.07-0.11 Mooney Viscosity (MU, ML1 + 8 @ 125° C.) 35-40 Gel Content (wt. %) <5.0 Mw (kg/mol) 450-550 Mn (kg/mol) 200-220 Mz (kg/mol) 900-1400 Conversion (%) 77-84 TABLE 2 Isoprene Content (mol %) 7.0-8.0 DVB Content (mol %) 0.07-0.11 Mooney Viscosity (MU, ML1 + 8 @ 125° C.) 35-40 Gel Content (wt. %) <5.0 Mw (kg/mol) 700-900 Mn (kg/mol) 100-105 Mz (kg/mol) 3200-5500 Conversion (%) 77-84 TABLE 3 Isoprene Content (mol %) 7.26 DVB Content (mol %) 0.18 Mooney Viscosity (MU, ML1 + 8 @ 125° C.) 28 Gel Content (wt. %) <5.0 Mw (kg/mol) 427 Mn (kg/mol) 132 Mz (kg/mol) 1026 Conversion (%) 50 TABLE 4 Isoprene Content (mol %) 7.0 DVB Content (mol %) N/A Mooney Viscosity (MU, ML1 + 8 @ 125° C.) 15 Gel Content (wt. %) <5 Mw (kg/mol) 358 Mn (kg/mol) 140 Mz (kg/mol) 1202 Conversion (%) 78 Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Butyl rubber is understood to be a copolymer of an isoolefin and one or more, preferably conjugated, multiolefins as comonomers. Commercial butyl comprises a major portion of isoolefin and a minor amount, not more than 2.5 mol %, of a conjugated multiolefin. Halogenated butyls are also well known in the art, and possess outstanding properties such as oil and ozone resistance and improved impermeability to air. Commercial halobutyl rubber is a halogenated copolymer of isobutylene and up to about 2.5 mol % of isoprene. Butyl rubber or butyl polymer is generally prepared in a slurry process using methyl chloride as a vehicle and a Friedel-Crafts catalyst as part of the polymerization initiator. The use of methyl chloride is advantageous because AlCl 3 , a relatively inexpensive Friedel-Crafts catalyst, is soluble in methyl chloride, as are the isobutylene and isoprene comonomers. Additionally, the butyl rubber polymer is insoluble in the methyl chloride and precipitates out of solution as fine particles. The polymerization is generally carried out at temperatures of about −90° C. to −100° C. See U.S. Pat. No. 2,356,128 and Ullmanns Encyclopedia of Industrial Chemistry , volume A 23, 1993, pages 288-295. Low polymerization temperatures are required in order to achieve molecular weights which are sufficiently high for rubber applications. Raising the reaction temperature or increasing the quantity of isoprene in the monomer feed results in poorer product properties, in particular, in lower molecular weights. However, a higher degree of unsaturation would be desirable for more efficient crosslinking with other, highly unsaturated diene rubbers (BR, NR or SBR). The molecular weight depressing effect of diene comonomers may, in principle, be offset by lower reaction temperatures. However, in this case the secondary reactions, which result in gelation, occur to a greater extent and these processes are more costly. Gelation at reaction temperatures of around −120° C. and possible options for the reduction thereof have been described (cf. W. A. Thaler, D. J. Buckley Sr., Meeting of the Rubber Division, ACS, Cleveland, Ohio, May 6-9, 1975, published in Rubber Chemistry & Technology 49, 960-966 (1976)). The auxiliary solvents such as CS 2 required for this purpose are not only difficult to handle, but must also be used at relatively high concentrations. A further disadvantage associated with the use of CS 2 lies in the fact that polymerization reactions of this type are homogeneous in nature. Consequently, there are significant increases in solution viscosity as the polymerization reaction proceeds. This in turn necessitates carrying out these polymerizations to lower conversions (i.e. lower amounts of polymer per unit volume of solvent and therefore a cost disadvantage) as high solution viscosities give rise to heat transfer problems. It is furthermore known to perform gel-free copolymerization of isobutene with various comonomers to yield products of a sufficiently high molecular weight for rubber applications at temperatures of around −40° C. using pretreated vanadium tetrachloride (EP-A1-818 476), a combination of nitro compounds and vanadium (EP-A-1 122 267) or zirconium compounds (WO-02/18460-A1) and others. The present invention operates in the absence of vanadium-, zirconium- and/or hafnium compounds. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides a continuous process for producing polymers having a Mooney viscosity of at least 25 Mooney-units and a gel content of less than 15 wt. % containing repeating units derived from at least one isoolefin monomer, more than 4.1 mol % of repeating units derived from at least one multiolefin monomer and optionally further copolymerizable monomers in the presence of AlCl 3 and a proton source and/or cationogen capable of initiating the polymerization process and at least one multiolefin cross-linking agent wherein the process is conducted in the absence of transition metal compounds. The present invention also provides a continuous slurry process for producing polymers having a Mooney viscosity of at least 25 Mooney-units and a gel content of less than 15 wt. % comprising repeating units derived from isobutene monomer, more than 4.1 mol % of repeating units derived from isoprene monomer and optionally further copolymerizable monomers in the presence of AlCl 3 and a proton source and/or cationogen capable of initiating the polymerization process and at least one multiolefin cross-linking agent wherein the process is conducted in the absence of transition metal compounds and organic nitro compounds. detailed-description description="Detailed Description" end="lead"? | 20040211 | 20071016 | 20050224 | 72241.0 | 0 | TESKIN, FRED M | PROCESS FOR PRODUCTION OF HIGH-ISOPRENE BUTYL RUBBER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,776,845 | ACCEPTED | Stirrup/foothold for climbing tree stands | A climbing tree stand includes a platform, a pair of support arms attached to the platform, and a pair of stirrup-like devices attached to the platform or the support arms and extending generally over the platform. The pair of stirrup-like devices are substantially rigid, and each comprises a molded plastic body. In one embodiment, the substantially rigid stirrup-like devices are attached to the support arms of the climbing tree stand and generally are curved downwardly towards the platform. | 1. A foot engaging member for use with a climbing tree stand assembly of the type including a platform and a support member attached to the platform, comprising: a mounting portion for attachment to the climbing tree stand assembly; and a tail portion having a curved elongate body and extending away from the head portion. 2. The foot engaging member of claim 1, wherein the mounting portion is configured to be attached to the support member of the climbing tree stand assembly. 3. The foot engaging member of claim 2, wherein the tail portion is configured to extend generally downwardly toward the platform of the tree stand assembly. 4. The foot engaging member of claim 1, wherein the foot engaging member is substantially rigid. 5. The foot engaging member of claim 4, wherein the foot engaging member comprises molded plastic. 6. The foot engaging member of claim 1, wherein the mounting portion is configured to secure the foot engaging member to either the support member or to the platform. 7. The foot engaging member of claim 6, wherein the mounting portion is secured to the support member with a fastener. 8. A climbing tree stand assembly comprising: a platform; a pair of support arms attached to the platform; and a pair of stirrup-like devices attached to the platform or the support arms and extending generally over the platform. 9. The climbing tree stand assembly of claim 8, wherein the pair of stirrup-like devices each comprise a curved elongate body portion and a clamping portion for attaching to either the platform or the support arms. 10. The climbing tree stand assembly of claim 9, wherein clamping portions are attached to the support arms. 11. The climbing tree stand assembly of claim 8, wherein the curved elongate body portions extend generally over the platform. 12. The climbing tree stand assembly of claim 9, wherein the stirrup-like devices are substantially rigid. 13. The climbing tree stand assembly of claim 12, wherein the stirrup-like devices each comprise a molded plastic body. 14. In a climbing tree stand of the type including a platform and a pair of support arms attached to the platform, the climbing tree stand for use by a user, the improvement therein comprising: a pair of rigid foothold devices attached to the platform or the support arms. 15. The improvement of claim 14 wherein the rigid foothold devices extend generally between the support arms and the platform. 16. The improvement of claim 14 wherein the rigid foothold devices are attached to the support arms and extend toward the platform. 17. The improvement of claim 14 wherein the rigid foothold devices comprise a curved elongate body portion and an attachment portion for attaching to either the platform or the support arms. 18. The improvement of claim 17 wherein the rigid foothold devices, together with the support arms and the platform, define a stirrup-like structure. 19. The improvement of claim 17 wherein the rigid foothold devices comprise a molded plastic body. 20. The improvement of claim 17 wherein the attachment portion of the rigid foothold devices comprises a yoke-like element for fastening to one of the support arms. | FIELD OF THE INVENTION The present invention relates generally to climbing tree stands and in particular relates to a foothold or stirrup-like device for use with such tree stands. BACKGROUND OF THE INVENTION For some years now, climbing tree stands have incorporated some form of flexible webbing attached to the outboard edges and the centerline of the standing platform, thus forming two loops under which the user would position his/her feet. The use of straps or webbing has become the dominant method of securing one's feet to climbing tree stand platforms. Originally, the loop size was fixed and required an elastic cord to be positioned behind the ankles to assure that the straps would not slip off the feet of the user. Later, an adjustable webbing system was designed to provide more versatility by accommodating different shoe sizes. The major problem with webbing-based systems is the requirement that the user be physically able to bend over and lift the strap to insert one's feet. Considering that this is being accomplished at an elevated position prior to descending from a hunt, there are certain obvious inherent risks in this task that could result in a fall. One device attempted to overcome these shortcomings by utilizing a straight bar or tube that spanned from one side frame to the opposite side frame. However, this device does not allow any lateral pressure to be applied to aid in control of the tree stand platform. SUMMARY OF THE INVENTION Briefly described, in an illustrative form the present invention comprises a climbing tree stand assembly including a platform and a pair of support arms attached to the platform. The climbing tree stand assembly also includes a pair of stirrup-like devices attached to the platform or the support arms and extending generally over the platform. Preferably, the stirrup-like devices each comprise a curved elongate body portion and a clamping portion for attaching to either the platform or the support arms. In one form of the invention, the clamping portions are attached to the support arms. Preferably, the stirrup-like devices are substantially rigid. In one form, the stirrup-like devices can be molded of plastic. Defined another way, the present invention can comprise a substantially rigid foot engaging member for use with a climbing tree stand of the type including a platform and a support member attached to the platform. Preferably, the foot engaging member includes a first portion for attachment to the climbing tree stand and another portion having a curved elongate body and extending away from the first portion. The first portion can include a clamping or mounting part for attachment to the tree stand. Preferably, the first portion is adjustably mounted on the tree stand so that different sized feet/shoes (or boots) can be accommodated therein. Preferably, the foot engaging member and the tree stand cooperate to form a stirrup-like structure into which the user can place a foot or shoe or boot. In one form, the foot engaging member is molded from plastic and is arcuate. Other materials can be employed, as well as other shapes. Generally speaking, the present invention forms somewhat of a “stirrup” that the user can slide his or her foot under and apply both lateral control and upward force to securely manipulate the climbing tree stand platform and perform the necessary actions required to ascend and descend the tree. Optionally, the device is adjustable for different shoe sizes by simply sliding the stirrup up or down the side frame. The downward extension of the stirrup allows the user to apply lateral force against the stirrup, further increasing the control of the tree stand platform as it is manipulated up and down the tree. In summary, this invention is a “hands-free” device that is a significant improvement over the conventional webbing design, primarily in the important categories of speed, ease-of-use and safety. BRIEF DESCRIPTION OF THE DRAWING FIGURES FIG. 1 is a perspective view of a foothold according to an illustrative form of the present invention shown attached to a climbing tree stand. FIG. 2 is a plan view of the foothold of FIG. 1. FIG. 3 is a side sectional view taken along the lines A-A of FIG. 2. FIG. 4 is a front sectional view taken along the lines B-B of FIG. 2. FIGS. 5A-5D are detailed views of the foothold of FIG. 1, shown apart from the climbing tree stand. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in detail to the drawing figures, wherein like reference numerals depict like parts throughout the several views, FIG. 1 illustrates one form of the present invention, in particular a climbing tree stand assembly 10. The climbing tree stand assembly 10 preferably includes a rigid climbing tree stand 15. In the illustrative embodiment depicted in the figures, the climbing tree stand 15 is shown as a cable-style tree stand. Those skilled in the art will recognize that the present invention is not limited to this particular style of climbing tree stand and that many different styles and designs of tree stands can be employed in or with the present invention. The climbing tree stand assembly 10 also includes a pair of rigid footholds or stirrups 100, 101. The footholds or stirrups 100, 101 are identical to one another, only their orientation on the climbing tree stand 10 differs. The immediately following section describes a cable-style climbing tree stand 15 that can be used in the present invention. After describing the stand, the description will continue with a description of the footholds or stirrups 100, 101. The Stand As shown in FIGS. 1-4, the climbing tree stand 15 includes a rigid platform structure indicated at 11 and a cable attachment indicated at 12. The rigid platform structure 11 includes a platform assembly indicated at 13. The platform assembly 13 includes a peripheral frame assembly 14 and a series of slats, such as slats 16-19. The peripheral frame assembly 14 also includes side frame members 27 and 28, as well as a generally U-shaped platform frame 31. The side frames 27 and 28 are welded to the U-shaped platform frame 31 in the vicinity of regions 29 and 30. The U-shaped platform frame 31 includes three portions which lie in the plane of the platform assembly 13, namely portions 32, 33, and 34. Moreover, the U-shaped platform frame 31 also includes two upwardly angled portions 36 and 37 for supporting the platform assembly adjacent a tree and for attachment to the cable attachment 12. Upwardly angled portions 36 and 37 have side surfaces 51, 52 and 53, 54, respectively. As best seen in FIGS. 3 and 1, the angled portions 36, 37 are oriented at an acute angle with respect to the remainder of the platform assembly 13. Preferably, the angle α is between about 10° and 40° and most preferably is about 26° or so and form crotches 21 and 22. While 26° has been found to work very well, other angles will work also. At the ends of the upwardly angled portions 36 and 37, cable retention cleats 38 and 39 are formed. The cable retention cleats 38, 39 can also be described as slotted clasps or sockets. A U-shaped vertical frame 41 extends between the side frames 27 and 28 and the cable retention cleats 38 and 39 of the upwardly angled portions 36 and 37 of the U-shaped platform frame 31. A generally V-shaped yoke 42 is positioned beneath the U-shaped vertical frame 41, is welded thereto, and faces away from the platform assembly 13. The yoke 42 is adapted for at least partly straddling the tree and will be described in more detail below. The frame components just described are made from 18 gauge steel tubing, 13/16 inches square. The individual pieces thereof are welded together and then powder coated (painted) to avoid corrosion. Referring again to the generally V-shaped yoke 42 of FIG. 2, the yoke includes tubular sections 46 and 47. Preferably, the inside faces 43 and 44 of the tubular sections 46, 47 are provided with a scalloped sill to help grip the tree and to avoid slippage in use. Having now described the basic structure of the platform itself, attention is directed to the cable attachment 12. For clarity of illustration, FIG. 1 depicts one end of the cable retained by cleat 38 and the other end of the cable retained by cleat 39. The cable attachment 12 includes a cable 50 adapted to be looped about a tree and may further include a series of cylindrical nuts (collars) formed on the cable at the ends thereof. The nuts (or sleeves) can be in the form of cylindrical ferrules that have been swaged onto the cable 50. Of course, those skilled in the art will recognize that other shapes for the nuts can be employed as well. For example, the nuts could be spherical or box-shaped. The cylindrically-shaped nuts provide good strength at a reasonable cost. Referring now again to FIG. 2, some other aspects of the platform and frame assembly will be considered. As shown in FIG. 2, the V-shaped yoke 42 includes first and second tubular sections 46 and 47, each of which is oriented at an angle β of 56° with respect to the U-shaped vertical frame 41. As a result, the included angle between the tubular sections 46 and 47 is 68°. It has been found that this angle is particularly effective for engaging a tree and results in the yoke at least partly straddling the tree over a wide range of diameters, including trees having diameters between about 8″ and slightly more than 20″. Applicants have also found that an included angle of 72° works very well too. The Stirrups/Footholds As depicted in FIG. 1, the climbing tree stand assembly 10 also includes a pair of rigid footholds or stirrups 100, 101. FIGS. 5A-5D detail the structure of the foothold 100. It should be noted that the structure of the foothold 101 is identical to that of the foothold 100, only the mounted orientation on the climbing tree stand 10 differs. The foothold 100 has a proximal end 102 and a distal end 103. Near the proximal end 102 is a head portion 104, and near the distal end 103 is a tail portion 105. Preferably, the head portion 104 and the tail portion 105 form a single continuous component. The head portion 104 and the tail portion 105 are constructed of a substantially rigid material. In one embodiment, the head portion 102 and the tail portion 104 comprise a molded plastic body. Of course, those skilled in the art will recognize that other materials for the footholds 100, 101 can be employed as well. For example, the footholds 100, 101 could be constructed of another durable material, such as a metal. The head portion 104 includes a generally U-shaped clamping member 106 that can be mated with the upwardly angled portion 36. The U-shaped clamping member 106 has three portions, namely flanges 108, 110 and surface 112. Flange 108 has a bore 114 for receiving the bolt 118 and a fastener opening 115 therethrough. Flange 110 has a hexagonal nut retention socket 116 and a fastener opening 117 therethrough. The bolt 118 is secured to the head portion 104 with a locknut 120. The tail portion 105 comprises a curved elongate body portion 122 that is curved generally downwardly toward the distal end 103. Preferably, with the foothold 100 attached to the angled portion 36, the tail portion 105 is configured to the engage a foot of the user of the tree stand 15. Those skilled in the art will recognize that the footholds 100, 101 can include other shapes that are configured to engage the feet of the user. In one embodiment of the climbing tree stand assembly 10, the clamping members 106 of the footholds 100, 101 are secured to the angled portions 36, 37 at preselected locations. The preselected locations are determined by the size of the user's feet such that the distance between point A, located at the distal end 103 of the foothold 100, and point B, located at crotch 21, is wide enough to accommodate the user's right foot. It should be noted the footholds 100, 101 can be positioned at any location along the angled portions 36, 37. For example, if the user has a relatively small foot, then the distance between points A and B can be decreased by moving the head portion 104 of the foothold 100 along angled portion 36 towards the platform 11. If the user has a relatively large foot, then the distance between points A and B can be increased by moving the head portion 104 of the foothold 100 along angled portion 36 toward the cleat 38. In one embodiment, the flanges 108, 110 of the foothold 100 engage the side surfaces 51, 52 of the angled portion 36. Once the foothold 100 is positioned at the preselected location, the bolt 118 is inserted through opening 115, over angled portion 36, and then through opening 117 of flange 110. The locknut 120 is threaded onto the bolt 118 in the retention socket 116, and when tightened, the locknut 120 secures the bolt 118, and consequently the foothold 100, to the climbing tree stand 15. In this embodiment, when the clamping member 106 is attached to the angled portion 36, the elongate body portion 122 of the foothold 100 extends generally toward and over the platform 11. While the invention has been shown and described in preferred forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein. For example, the footholds can be secured to the platform of the tree stand assembly. These and other changes can be made without departing from the spirit and scope of the invention as set forth in the following claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>For some years now, climbing tree stands have incorporated some form of flexible webbing attached to the outboard edges and the centerline of the standing platform, thus forming two loops under which the user would position his/her feet. The use of straps or webbing has become the dominant method of securing one's feet to climbing tree stand platforms. Originally, the loop size was fixed and required an elastic cord to be positioned behind the ankles to assure that the straps would not slip off the feet of the user. Later, an adjustable webbing system was designed to provide more versatility by accommodating different shoe sizes. The major problem with webbing-based systems is the requirement that the user be physically able to bend over and lift the strap to insert one's feet. Considering that this is being accomplished at an elevated position prior to descending from a hunt, there are certain obvious inherent risks in this task that could result in a fall. One device attempted to overcome these shortcomings by utilizing a straight bar or tube that spanned from one side frame to the opposite side frame. However, this device does not allow any lateral pressure to be applied to aid in control of the tree stand platform. | <SOH> SUMMARY OF THE INVENTION <EOH>Briefly described, in an illustrative form the present invention comprises a climbing tree stand assembly including a platform and a pair of support arms attached to the platform. The climbing tree stand assembly also includes a pair of stirrup-like devices attached to the platform or the support arms and extending generally over the platform. Preferably, the stirrup-like devices each comprise a curved elongate body portion and a clamping portion for attaching to either the platform or the support arms. In one form of the invention, the clamping portions are attached to the support arms. Preferably, the stirrup-like devices are substantially rigid. In one form, the stirrup-like devices can be molded of plastic. Defined another way, the present invention can comprise a substantially rigid foot engaging member for use with a climbing tree stand of the type including a platform and a support member attached to the platform. Preferably, the foot engaging member includes a first portion for attachment to the climbing tree stand and another portion having a curved elongate body and extending away from the first portion. The first portion can include a clamping or mounting part for attachment to the tree stand. Preferably, the first portion is adjustably mounted on the tree stand so that different sized feet/shoes (or boots) can be accommodated therein. Preferably, the foot engaging member and the tree stand cooperate to form a stirrup-like structure into which the user can place a foot or shoe or boot. In one form, the foot engaging member is molded from plastic and is arcuate. Other materials can be employed, as well as other shapes. Generally speaking, the present invention forms somewhat of a “stirrup” that the user can slide his or her foot under and apply both lateral control and upward force to securely manipulate the climbing tree stand platform and perform the necessary actions required to ascend and descend the tree. Optionally, the device is adjustable for different shoe sizes by simply sliding the stirrup up or down the side frame. The downward extension of the stirrup allows the user to apply lateral force against the stirrup, further increasing the control of the tree stand platform as it is manipulated up and down the tree. In summary, this invention is a “hands-free” device that is a significant improvement over the conventional webbing design, primarily in the important categories of speed, ease-of-use and safety. | 20040211 | 20090915 | 20050811 | 67442.0 | 1 | CHAVCHAVADZE, COLLEEN MARGARET | FOOTHOLD FOR CLIMBING TREE STANDS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,776,976 | ACCEPTED | Method and controller for identifying double tap gestures | A method of identifying double tap gesture, wherein the double tap gesture is produced on a touch device and characterize in that: when the summation of the first appearing time duration, the time span between the two appearing time durations and the second appearing time duration is smaller than the first reference time, then generate a first signal that represents the first and second appearances. This is to simulate the double tap signal output from the double clicking of the mouse button and so as to achieve a short, simple and reliable determination. | 1. A method of identifying double tap gesture with which the double tap gesture is performed on a touch device, comprising follow steps: i. Detecting a first appearance of an object on the touch device; ii. Detecting a second appearance of the object on the touch device; and iii. generating a first signal that represents the first and second appearances in case of the summation of a first appearing time duration, a second appearing time duration and a time span between the two appearing time durations being smaller than a first reference time. 2. The method of identifying double tap gesture as defined in claim 1, wherein the first signal is generated when the accumulated displacement of the second appearing duration is smaller than the reference displacement value. 3. The method of identifying double tap gesture as defined in claim 1, wherein the first signal is generated when the first appearing time duration is larger than the first minimum tap reference time value. 4. The method of identifying double tap gesture as defined in claim 1, wherein the first signal is generated if the second appearing time duration is larger than the second minimum tap reference time value. 5. The method of identifying double tap gesture as defined in claim 1, wherein the first signal is generated when the time span between the ending of the first appearing time duration and the start of the second appearing time duration is larger than the first minimum UP reference time value. 6. The method of identifying double tap gesture as defined in claim 1, 2, 3, 4, or 5 wherein the first signal will be generated when there is no detection of a new appearance within the time after the ending of the second appearance that is at least larger than the second minimum UP reference time value. 7. The method of identifying double tap gesture as defined in claim 1, wherein the first signal is transmitted to a host. 8. A controller of the touch device, with which it is used to identify gesture of an object on the touch device, the controller comprising: an operational unit, being used to detect every appearance of the object on the touch device and accordingly producing a respective tap signal, the respective tap signal being generated corresponding to the start of the appearance on the touch device and being terminated when that appearance finishes; and a gesture unit, being connected to the operational unit so as to receive the tap signal, calculating the time duration of the object appearing on the touch device based on the tap signal and identifying movement of the object; wherein, the gesture unit receives from the operating unit the generated first tap signal and the second tap signal corresponding to the first and second appearance of the object on the touch device respective; the gesture unit also computes the summation of the first appearing time duration, the second appearing time duration and then time span between the two appearing time durations and compares this result with the first reference time; and if the sum is smaller than the first reference time value, then produce the first signal that presents the first and second appearance. 9. The controller of identifying double tap gesture as defined in claim 8, wherein the tap signal generated by the operational unit includes the amount of displacement on the touch device. 10. The controller of identifying double tap gesture as defined in claim 9, wherein the first signal will be generated by the gesture unit when the accumulated displacement of the second appearing time duration computed by the gesture unit is smaller than the reference displacement value. 11. The controller of identifying double tap gesture as defined in claim 8, wherein the first signal will be generated by the gesture unit only when the first appearing time duration is larger than the first minimum tap reference time value. 12. The controller of identifying double tap gesture as defined in claim 8, wherein the first signal will be generated by the gesture unit when the second appearing time duration is larger than the second minimum tap reference time value. 13. The controller of identifying double tap gesture as defined in claim 8, wherein the first signal will be generated by the gesture unit when the time span between finish of the first appearing time duration and the start of the second time duration is larger than the first minimum UP reference time value. 14. The controller of identifying double tap gesture as defined in claim 8, 10, 11, 12 or 13 wherein the first signal will be generated by the gesture unit when there is no detection of a new appearance within the time after the ending of the second appearance that is at least larger than the second minimum UP reference time value. 15. The controller of identifying double tap gesture as defined in claim 8, wherein the controller further includes a transmitter interface that is connected to the gesture unit and transmit the first signal to a host. 16. A gesture unit of the touch device, which is used to identify movement of an object on the touch device, wherein the gesture unit receives from the operating unit the generated first tap signal and the second tap signal corresponding to the first and second appearance of the object on the touch device respective, the gesture unit also computes the summation of the first appearing time duration, the second appearing time duration and then time span between the two appearing time durations and compares this result with the first reference time; and if the sum is smaller than the first reference time value, the first signal that presents the first and second appearance is produced. 17. The gesture unit as defined in claim 16, wherein the first signal is generated when the accumulated displacement of the second appearing time duration is smaller than the reference displacement value. 18. The gesture unit as defined in claim 16, wherein the first signal is generated when the first appearing time duration is larger than the first minimum tap reference time value. 18. The gesture unit as defined in claim 16, wherein the first signal is generated when the second appearing time duration is larger than the second minimum tap reference time value. 19. The gesture unit as defined in claim 16, wherein the first signal is generated when the time span between the finish of the first appearing time duration and the start of the second appearing time duration is larger than the first minimum UP reference time value. 20. The gesture unit as defined in claim 16, 17, 18, 19 or 20 wherein the first signal is generated when there is no detection of a new appearance within the time after the ending of the second appearance that is at least larger than the second minimum UP reference time value. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and controller for identifying double tap gestures, especially referring to a method and controller for identifying double tap gestures on touch device. When the touch device identifies the double tap gesture, simulate a double tap signal that represent a series of consecutive double clicking of the mouse button (usually the default is the left button). 2. Brief Description of Related Art: Graphical User Interface, GUI, accompanying by the pointing device (such as a mouse) was the first program operation interface released by the PARC research group. The user can easily accomplish the executed action by just using the visual type of pointer through the movement and clicking of the mouse, this solves the inconvenience created by the input of complex instruction during the text mode. Therefore, GUI is commonly used by Apple computers and Microsoft and it becomes a mainstream interface of all the operating systems. In the electronic devices that utilize GUI, such as desktop computer, portable computer, tablets, personal digital assistant and so on, pointing device has become a basic accessory. Currently, the pointing device includes external mouse, track-ball and touch pad built-in on the portable computers, the touch panel incorporated with the monitor and so on. The mouse is the pointing device that is released the earliest. Using the mouse as an example to illustrate the functionality of the pointing device, the mouse is able to control the pointer on the monitor screen, which means that the pointer will follow to anywhere the mouse moves to and when clicking of the control button is performed at the to be executed target on the monitor, then the instruction will be executed to the electronic device. However, the current trend of the electronic equipment is heading towards small and light, for example, the portable computers are gradually replacing the export of the desktop computers and this results the small-sized touch device (e.g. touch pad) to be slowly become the mainstream of pointing device. Presently, the touch device technology includes capacitor type, resistive type, magnetic type, pressure type, inductance type, surface sonar type, supersonic type, and optical type and so on. When an object such as a finger moves on the touch device, it can control the pointer to move in the direction of the movement of the object. Moreover, the pointing device besides controlling the pointer, it also has the function to execute instruction. Using the mouse as an example, when the pointer moves over the target (e.g. program, document) to be started, double clicking the mouse button (default to be left button in most system) will select the target and opens it. However, for touch device such as touch pad, currently two control buttons have been installed below to replace the left and right buttons of the mouse or by defining certain gesture on the touch device to generate signal corresponding to the simulated double clicking. Currently, the touch device opens the selected target by tapping the touch device consecutively twice gesture (known as double tap gesture in the following text), which replaces the double clicking action of the mouse. Thus, a conventional method of identifying double tap gesture is described in U.S. Pat. No. 6,414,671. Referring to FIG. 1 (corresponding to FIG. 15F in U.S. Pat. No. 6,414,671 specification), first of all, compare the first appearing time duration t19 of the object on the touch device (refers to the time of stay of the object first appeared on the touch device) with the first reference time, if the first appearing time duration t19 is smaller than the first reference time value, then produce a first signal 11; after that, if second appearance is not detected within the time of the second reference time, terminates the first signal, in other words, the time span between the two appearing time duration t20 has to be smaller than the second reference time value; next, compare the second appearing time duration t21 with the third reference time value, if the second appearing time duration t21 is shorter than the third reference time value, then terminates the first signal and produce a second signal 12, therefore it can output two signals 11 and 12 to simulate the signal of double clicking of the mouse button. Even though the conventional method can achieve the objective of identifying the double tap gesture, however in the conventional method, it makes the determination to be more complex by comparing the first appearing time duration t19, time span between two appearing time duration t20, and the second appearing time duration t21 with the respective reference time values. Additionally, since the user differs from one another, therefore, when each person perform the double tap gesture on the touch device will have different length of time in each step of the action or even for the same user to perform the every double tap gesture on the touch device will vary in time for each action, thus resulting in the situation where a misinterpretation has occurred. Also, during the operation of the touch device, it can be easily touched by mistake, or due to the noise of the touch device itself, or interference by the noise from the surrounding environment will all produce short spike of the first and second appearance phenomenon. The conventional method does not have minimum time restriction on the first and second appearing time duration and the time span between the two appearing time durations; therefore, the interference signal produced due to noise will cause inappropriate determination and easily allow the situation of misinterpretation to happen. Moreover, as the tap and drag gesture also taps on the touch device twice where during the drag of the second tap, the conventional method did not take into the consideration of the accumulated displacement of the second appearing duration, it will easily cause the misinterpretation of the double tap gesture with the tap and drag gesture. SUMMARY OF INVENTION A main objective according to the present invention is to provide a method and controller for identifying double tap gesture, utilizing the comparison of the total time duration for each action with the first reference time value in order to achieve a faster and more reliable determination. Another objective of the present invention is to provide a method and controller for identifying double tap gesture, wherein the time duration of each respective action has to be larger than the corresponding pair of reference values so as to effectively avoid the situation where a misinterpretation might occur due to noise signal. A further objective of the present invention is to provide a method and controller for identifying double tap gesture, wherein the displacement detected during the second occurrence has to be smaller than the corresponding reference value so to achieve an accurate determination. The method of identifying double tap gesture according to the present invention, wherein the double tap gesture is performed on a touch pad and the method includes the following steps: i. detecting the first occurrence of an object on the touch pad; ii. detecting the second occurrence of the particular object on the touch pad; and iii a first signal representing the first and second appearance being immediately generated in case of the summation of the first appearing time duration, the second appearing time duration and the time span between the end of first appearing time duration and the start of the second appearing time duration is smaller than first reference time value. BRIEF DESCRIPTION OF THE DRAWINGS The present invention can be more fully understood by reference to the following description and accompanying drawings, in which: FIG. 1 is a diagram illustrating time pulse of conventional double tap gesture; FIG. 2 is a block diagram illustrating touch device of a preferred embodiment in a method associated with the present invention for identifying double tap gesture; FIG. 3 is diagram illustrating time impulse of an input and an output signal shown in FIG. 2; and FIG. 4 is a flow chart of the embodiment shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First and foremost, the method and controller for identifying double tap gesture according to the present invention is to be applied on a touch device. To simplify the explanation, a capacity type touch device will be selected for illustrating the preferred embodiment of the present invention. Referring to FIG. 2, a capacity type touch device 2 includes at least one touch pad 21, one treat unit along X direction 22, one treat unit along Y direction 23, one operational unit 24, one displacement unit 25, one gesture unit 26 and a transmitter interface 27. The touch pad 21 has multiple wires distributed in the X and Y direction respectively, for example 16 wires in the X direction and 12 wires in the Y direction. Therefore, when a conductive object such as a finger 10 touches and in close contact with the touch pad 21, it will cause a change in the capacitance on the touch pad 21. The X and Y direction treat units will immediately process the respective capacitance on the X and Y direction and transmit the data to operational unit 24. The operational unit 24 based on the received data will compute the X and Y coordinates of the object contact location. After that, the displacement unit 25 will receive the X and Y coordinates computed by the operational unit 24 and based on this information calculate the relative displacement Dx and Dy (referring to the contact signal) of the object on the touch pad 21 and transmit them to the gesture unit 26 and transmitter unit 27. Thus the calculated result Dx and Dy can be transmitted to a host 3 through the transmitter unit 27 so that the host 3 can control the movement of the pointer on the screen. Host 3 can be a personal computer, laptop, personal digital assistant (PDA), or a cellular phone. Hence, the previous mentioned components are not the characteristics of the present invention and commonly known by the people familiar with the art, no further explanation will be illustrated here. Furthermore, the operational module, displacement unit 25, gesture unit 26 and transmitter interface 27 in the preferred embodiment of present invention are all included in a controller such as a chip. The gesture unit 26 receives the calculation results Dx and Dy from the displacement unit 25 to determine if the object has produced an action qualified as a double tap gesture on the touch pad 21 and also during this determination whether the action is a double tap gesture, correspondingly transmits out the first signal of the simulated double clicking through the transmitter interface to the host 3 in order to carry out the corresponding control. The characteristic technique of the present invention is the method of identifying double tap gesture in the gesture unit 26. The gesture unit 26 can achieve the method of identifying double tap gesture through software, firmware or hardware. Moreover, even though the gesture unit 26 in the example of the present invention is embedded in the controller of the touch device 2, it can be installed in the host 3 as a software or hardware and not just limited to technique used in the preferred embodiment of the present invention. Besides, even though a capacity type touch device 2 is used as an example in the preferred embodiment of the present invention, persons with knowledge of this convectional art should know that the present invention can be applied onto other types of touch device, such as optical type, resistive type, magnetic type, pressure type, inductance type, surface sonar type, supersonic type and so on. Therefore, it is not confined to just what is illustrated in the preferred embodiment of the present invention. Referring to FIG. 3 and FIG. 4, they illustrate the flow chart of an example in the preferred embodiment of the present invention. In the example, first assume that an object such as a finger 10 has simultaneously tapped on the touch pad 21 twice. To simplify the explanation, in the following paragraphs, the object will be represented by the finger 10. Something worth noting is that even though a finger is used to illustrate the preferred embodiment of the present invention, persons familiar with the conventional art should know that the touch device 2 of the preferred embodiment is suitable for detecting other types of conductive objects or multiple conductive objects, which is not confined to what is revealed in the preferred embodiment of the present invention. First of all, in step 41, the touch device 2 detects the finger 10 on the touch pad 21 at the start of its first appearance. When the touch device 2 detects the first appearing time duration, gesture unit 26 will start timer immediately. Subsequently, in step 42, it is to be determined which of the two conditions: the ending of the first appearing time duration or the timer after the first appearing time duration has reached the first reference time T1, has been achieved first. In the present example, assume that within the first reference time T1, the second tap of the double tap gesture should be able to be detected. The range of the first reference time T1 in the present example is between 100 ms and 1000 ms (100 ms<T1<1000 ms), but it can be adjusted according to the need of the designer or the user's operating preference. If in step 42, it has been determined that the timer has reached the value of first reference time T1, it can be confirmed that it is not a double tap gesture as the first appearing time duration has not finished and the second appearing time duration is not yet detected as well. Thus step 43 will be executed to determine if the action is of any other gestures. If in step 42, it has been determined that time first appearing time duration has ended and the timer has not reached the first reference time T1, step 44 will be executed. In step 44, it continues to determine which of the conditions: the start of the second appearing time duration or the timer has reached the first reference time T1, has been achieved first. Similarly, if in step 44, it has been determined that the timer has reached the value of first reference time T1 first, it can be confirmed that it is not a double tap gesture as the start of the second appearing time duration is not yet detected within the first reference time T1. Thus step 43 will be executed to determine if the action is of any other gestures. However, if in step 44, it has been determined that the start of the second appearing time duration is detected first, it implies that a double tap gesture may have occurred within the first reference time T1 and step 45 will be continued. Referring to FIG. 3, at the start of the second appearing time duration, the gesture unit 26 from the input signals can obtain the first appearing time duration Tdown1 and the time span between two appearing time duration Tup1. Touch pad 21 during its operation can be easily touched by mistake or due to the noise generated by itself or noise from the surrounding environment and then produce inappropriate signals such as short first and second appearing time duration or short time span between the two appearing time duration. As these unwanted signals only last a short period of time, in the following steps 45, 46, 48 and 49 of the preferred embodiment of the present invention, there is a requirement that the time duration of each action must be larger than the respective minimum time value, in order to effectively filter out inappropriate signals and thus enhance the accuracy of the identification. In step 45, first determine if the time span Tup1 between the first appearing time duration T1 and the second appearing time duration T2 is larger than the first minimum UP reference time T21. The first minimum UP reference time T21 is the shortest effective time between the UP and DOWN of the finger 10. The first time span Tup1 is the time between the tapping of the finger 10 on the touch pad 21 followed by leaving the touch pad 21 and until the second tapping of the finger 10 on the touch pad 21. In the present example, the first minimum UP reference time T21 ranges from 1 ms to 10 ms (1 ms<T23≦10 ms) and it can be adjusted according to the need of the designer or the operating preference of the user. If step 45 determines the first time span Tup1 to be larger than the first minimum UP reference time T21 (Tup1>T21), it represents that the signal of the first time span Tup1 is valid and thus it will continue to step 46. If step 45 determines that the first time span Tup1 is not larger than the first minimum UP reference time T21 (Tup1≦T21) it implies that the first UP signal has to be considered as noise signal as its time duration is too short, thus the first appearing time duration has not really finished and it will jump back to step 42 to continue detect the finish of the first appearing time duration. In step 46, determine if the first appearing time duration Tdown1 is larger than the first minimum tap reference time T31. Since usually when the finger 10 appeared on the touch pad 21 implies that the finger 10 is down on the touch pad 21, then the shortest effective time the finger 10 first tap on the touch pad 21 and stays on it is called the first minimum tap reference time T31. If in step 46, it is determined that the first appearing time duration Tdown1 is larger than the first minimum tap reference time T31 (Tdown1>T31), it indicates that the first appearance is a valid signal and step 47 will be continued. However, if step 46 determines the condition to be false (Tdown1≦T31), which implies that the first appearance is a noise signal and will be discarded, it will jump back to step 41 and resume to wait for the next first appearance. After the detection of the second appearing time duration, the gesture unit 26 besides resuming the timer, it uses the displacement unit 25 to calculate the accumulated displacement of the second appearing time duration Mdown2. In step 47, determines which of the following three conditions is achieved first: detection of the finish of the second appearing time duration, the accumulated displacement of the second appearing time duration Mdown2 is not less than the reference displacement value M1 or the timer since the first appearing time duration has reached the first reference time T1. If in step 47, the condition that the second appearing time duration finishes is determined first, it implies that within the first reference time T1, two appearances have really been detected and the accumulated displacement of the second appearing time duration Mdown2 is less than the reference displacement value M1 (Mdown2<M1). What follows is to verify that in step 48 and 49 respectively, the second appearing time duration has truly finished and the second appearance is a valid signal, and then it will confirm that the two appearances is a double tap gesture. In step 48, determine if the time span after the second appearing time duration Tup2 is larger than the second minimum UP reference time T22. If step 48 determines that is the time span after the second appearing time Tup2 is larger than the second minimum UP reference time T22 (Tup2>T22), it implies that the second appearance has truly finished and step 49 will be continued. However, if step 48 determines that the time span after the second appearing time duration Tup2 is not larger than the second minimum UP reference time T22 (Tup1≦T22), it implies that the UP during the time span after the second appearing time is noise signal and thus will be discarded and jump back to step 47 to resume waiting for the real UP signal which indicates the finish of the second appearing time duration. In the present example, the second minimum UP reference time T22 can be set to be the same as the first minimum UP reference time T21. In step 49, determines if the second appearing time duration Tdown2 is larger than the second minimum tap reference time T32. If step 49 determines the second appearing time duration Tdown2 is larger than the second minimum tap reference time T32 (Tdown2>T32), thus it indicates the signal of the second appearance is a valid signal. Then, as the summation of the first appearing time duration Tdown1, time span between the two appearing time duration Tup1 and the second appearing time duration Tdown2 is smaller than the first reference time T1 [(Tdown1+Tdown2+Tup1)<T1] and the accumulated displacement of the second appearing time duration Mdown2 is also smaller than the reference displacement M1 (Mdown2<M1), step 50 will be executed. However, if step 49 determines that the condition is false (Tdown2≦T32), the second appearing time duration is too short and will be considered as noise so the signal of the second appearing time will be discarded and jump back to step 44 to wait for the start of the real second appearing time duration. In the present example, the second minimum tap reference time T32 can be set to be the same as the first minimum tap reference time T31. In step 50, gesture unit 26 will output a first signal through the transmitter interface 27 into the host 3 to notify the host that a double tap gesture has been produced and simulate the signal produced by double clicking of the mouse button. Referring to FIG. 3, the signal 51 and 52 in the present example will only be sent together after the detection of the second appearance and the double tap gesture is confirmed. It differs from the convectional method of identifying where the first signal is produced immediately after the first tap. If in step 47, it is determined first that the accumulated displacement of the second appearing time duration Mdown2 is not less than the reference displacement M1 (Mdown2≧M1), it implies that when the finger 10 taps on the touch pad 21 for the second time has not move and thus it could be a tap and drop gesture instead of double tap gesture so it will jump back to step 43 to determine if it is any other gestures. Thus, it will effectively reduce or avoid the chance that the tap and drop gesture is determined as the double tap gesture. The range of the reference displacement M1 in the present example can vary between 1 pixel and 10 pixel (1 pixel≦M1≦10 pixel), such as 3 pixel or it can be adjusted according to the need of the designer or the operating preference of the user. Similarly, if in step 47, it is determined first that the timer since the first appearance has already reached the first reference time T1, it implies that the summation of the first appearing time duration Tdown1, time span between the two appearing time duration Tup1 and the second appearing time duration Tdown2 is not smaller than the first reference time T1 [(Tdown1+Tdown2+Tup1)≧T1], thus the two appearances are not double tap gesture and will jump to step 43 instead to determine if it is of any other gestures. Summarising the previous claims, the requirement for the double tap gesture in the preferred embodiment of the present invention is defined by the following equations: Tdown1>T31 Eq. 1 Tdown2>T32 Eq. 2 Tup1>T21 Eq. 3 Tup1>T22 Eq. 4 (Tdown1+Tdown2+Tup1)<T1 Eq. 5 Mdown2<M1 Eq. 6 It should be noted that even the previous mentioned steps 42, 44 and 47 can simultaneously determine multiple conditions. The person familiar with the convectional arts should know that the previous mentioned steps 42, 44 and 47 can also determine the conditions sequentially, so it is not just limited to what has been revealed in the preferred embodiment of the present invention. It is appreciated that the present invention is different from the convectional method with which the time of each respective step is determined by way of if it is smaller than the respective reference time value and the method of identifying double tap gesture according to the present invention sums up the overall time duration of each action, Tdown1, Tdown2 and Tup1 and determine if it is not smaller than the first reference time T1 (refer to Eq. 5) so as to achieve a short, effective and reliable determination. Moreover, the present invention further requires that the time duration of each action has to be larger than their respective reference values T31 (refer to Eq. 1), T21 (refer to Eq. 2) and T22 (refer to Eq. 4) so as to effectively filter out the inappropriate signals generated due to disturbance and thus achieve a more accurate determination. In addition, the present invention also requires that the accumulated displacement of the second appearing time duration Mdown2 has to be smaller than reference displacement M1 (refer to Eq. 6), this will differentiate the double tap gesture from the tap and drop gesture and effectively avoid the misjudgement of the tap and drop gesture as the double tap gesture, and further achieve a more accurate determination. While the invention has been described with reference to the a preferred embodiment thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a method and controller for identifying double tap gestures, especially referring to a method and controller for identifying double tap gestures on touch device. When the touch device identifies the double tap gesture, simulate a double tap signal that represent a series of consecutive double clicking of the mouse button (usually the default is the left button). 2. Brief Description of Related Art: Graphical User Interface, GUI, accompanying by the pointing device (such as a mouse) was the first program operation interface released by the PARC research group. The user can easily accomplish the executed action by just using the visual type of pointer through the movement and clicking of the mouse, this solves the inconvenience created by the input of complex instruction during the text mode. Therefore, GUI is commonly used by Apple computers and Microsoft and it becomes a mainstream interface of all the operating systems. In the electronic devices that utilize GUI, such as desktop computer, portable computer, tablets, personal digital assistant and so on, pointing device has become a basic accessory. Currently, the pointing device includes external mouse, track-ball and touch pad built-in on the portable computers, the touch panel incorporated with the monitor and so on. The mouse is the pointing device that is released the earliest. Using the mouse as an example to illustrate the functionality of the pointing device, the mouse is able to control the pointer on the monitor screen, which means that the pointer will follow to anywhere the mouse moves to and when clicking of the control button is performed at the to be executed target on the monitor, then the instruction will be executed to the electronic device. However, the current trend of the electronic equipment is heading towards small and light, for example, the portable computers are gradually replacing the export of the desktop computers and this results the small-sized touch device (e.g. touch pad) to be slowly become the mainstream of pointing device. Presently, the touch device technology includes capacitor type, resistive type, magnetic type, pressure type, inductance type, surface sonar type, supersonic type, and optical type and so on. When an object such as a finger moves on the touch device, it can control the pointer to move in the direction of the movement of the object. Moreover, the pointing device besides controlling the pointer, it also has the function to execute instruction. Using the mouse as an example, when the pointer moves over the target (e.g. program, document) to be started, double clicking the mouse button (default to be left button in most system) will select the target and opens it. However, for touch device such as touch pad, currently two control buttons have been installed below to replace the left and right buttons of the mouse or by defining certain gesture on the touch device to generate signal corresponding to the simulated double clicking. Currently, the touch device opens the selected target by tapping the touch device consecutively twice gesture (known as double tap gesture in the following text), which replaces the double clicking action of the mouse. Thus, a conventional method of identifying double tap gesture is described in U.S. Pat. No. 6,414,671. Referring to FIG. 1 (corresponding to FIG. 15F in U.S. Pat. No. 6,414,671 specification), first of all, compare the first appearing time duration t 19 of the object on the touch device (refers to the time of stay of the object first appeared on the touch device) with the first reference time, if the first appearing time duration t 19 is smaller than the first reference time value, then produce a first signal 11 ; after that, if second appearance is not detected within the time of the second reference time, terminates the first signal, in other words, the time span between the two appearing time duration t 20 has to be smaller than the second reference time value; next, compare the second appearing time duration t 21 with the third reference time value, if the second appearing time duration t 21 is shorter than the third reference time value, then terminates the first signal and produce a second signal 12 , therefore it can output two signals 11 and 12 to simulate the signal of double clicking of the mouse button. Even though the conventional method can achieve the objective of identifying the double tap gesture, however in the conventional method, it makes the determination to be more complex by comparing the first appearing time duration t 19 , time span between two appearing time duration t 20 , and the second appearing time duration t 21 with the respective reference time values. Additionally, since the user differs from one another, therefore, when each person perform the double tap gesture on the touch device will have different length of time in each step of the action or even for the same user to perform the every double tap gesture on the touch device will vary in time for each action, thus resulting in the situation where a misinterpretation has occurred. Also, during the operation of the touch device, it can be easily touched by mistake, or due to the noise of the touch device itself, or interference by the noise from the surrounding environment will all produce short spike of the first and second appearance phenomenon. The conventional method does not have minimum time restriction on the first and second appearing time duration and the time span between the two appearing time durations; therefore, the interference signal produced due to noise will cause inappropriate determination and easily allow the situation of misinterpretation to happen. Moreover, as the tap and drag gesture also taps on the touch device twice where during the drag of the second tap, the conventional method did not take into the consideration of the accumulated displacement of the second appearing duration, it will easily cause the misinterpretation of the double tap gesture with the tap and drag gesture. | <SOH> SUMMARY OF INVENTION <EOH>A main objective according to the present invention is to provide a method and controller for identifying double tap gesture, utilizing the comparison of the total time duration for each action with the first reference time value in order to achieve a faster and more reliable determination. Another objective of the present invention is to provide a method and controller for identifying double tap gesture, wherein the time duration of each respective action has to be larger than the corresponding pair of reference values so as to effectively avoid the situation where a misinterpretation might occur due to noise signal. A further objective of the present invention is to provide a method and controller for identifying double tap gesture, wherein the displacement detected during the second occurrence has to be smaller than the corresponding reference value so to achieve an accurate determination. The method of identifying double tap gesture according to the present invention, wherein the double tap gesture is performed on a touch pad and the method includes the following steps: i. detecting the first occurrence of an object on the touch pad; ii. detecting the second occurrence of the particular object on the touch pad; and iii a first signal representing the first and second appearance being immediately generated in case of the summation of the first appearing time duration, the second appearing time duration and the time span between the end of first appearing time duration and the start of the second appearing time duration is smaller than first reference time value. | 20040212 | 20070313 | 20050818 | 66137.0 | 17 | OSORIO, RICARDO | METHOD AND CONTROLLER FOR IDENTIFYING DOUBLE TAP GESTURES | SMALL | 0 | ACCEPTED | 2,004 |
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10,776,977 | ACCEPTED | Method and controller for identifying a drag gesture | A method of identifying a drag gesture, with which the drag gesture is performed on a touch device and the method is characterized in that a drag signal can be generated when a sum of time duration of the first appearance and time span between an end of the first appearance time duration and a start of the second appearance is less than a first reference time, a sum of the first appearance time duration, the time span and a second appearance time duration is not less than the reference time value and an accumulated displacement of the second appearance time duration is not less than a reference displacement. | 1. A method of identifying a drag gesture, with which the drag gesture is performed on a touch device, the method comprising follow steps: i. detecting a first appearance of an object on the touch device; ii. detecting a second appearance of the object on the touch device; and iii. a sum of time duration of the first appearance and time span between an end of the first appearance time duration and a start of the second appearance being smaller than a first reference time and meeting one of following two situation, then generating a drag signal: (C) another summation of the first appearance time duration, the time span and a second appearance time duration being not less than the reference time value; and (D) an accumulated displacement of the second appearance time duration being not less than a reference displacement. 2. The method of identifying a drag gesture as defined in claim 1, wherein the drag signal is generated once at the summation of the first appearance time duration, the time span between the end of the first appearance time duration and the start of the second time duration and the second appearance time duration exceeds the reference time value. 3. The method of identifying a drag gesture as defined in claim 1, wherein the drag signal is generated once the accumulated displacement of the second appearance time duration is not less than the reference displacement. 4. The method of identifying a drag gesture as defined in claim 1, wherein the drag signal is generated once the first appearance time duration is greater than a first minimum tap reference time value. 5. The method of identifying a drag gesture as defined in claim 1, wherein the drag signal is generated once the second appearance time duration is greater than a second minimum tap reference time value 6. The method of identifying drag gesture as defined in claim 1, wherein the drag signal is generated once the time span between the end of the first appearance time duration and the start of the second time duration is greater than a first minimum raised up reference time value. 7. The method of identifying a drag gesture as defined in claim 1, wherein the touch device transmits the drag signal to the main unit. 8. A controller of a touch device for identifying movements of an object on the touch device, comprising: an operational unit, detecting every appearance of the object on the touch device and producing a respective tap signal and the respective tap signal being generated corresponding to a start of the appearance on the touch device and being terminated when that appearance has already finished; and A gesture unit, being connected to the operational unit so as to receive the tap signal and based on the tap signal to calculate the time duration of the object appearing on the touch device and then identify the action of the object; wherein, the gesture unit receives from the operational unit a first tap signal and a second tap signal corresponding to the first and second appearance of the object on the touch device respectively; the gesture unit also computes a summation of time duration of the first appearance and time span between an end of the first appearance time duration and a start of the second appearance being less than a first reference time and compares the result with the first reference time and if it qualifies one of the two conditions below, the gesture unit will produce a corresponding drag signal: A) if the summation of the first appearance time duration, the time span between the end of the first appearance time duration and the start of the second appearance is not less than a reference time value; and B) If the accumulated displacement of the second appearance time duration is not less than a reference displacement. 9. The controller of a touch device for identifying a drag gesture as defined in claim 8, wherein the gesture unit generates the drag signal at the time of an accumulated time of the first appearance time duration, the time span and the second appearance time duration exceeds the reference time. 10. The controller of a touch device for identifying a drag gesture as defined in claim 8, wherein the gesture unit generates the drag signal once the accumulated displacement is not less than the reference displacement within the second appearance time duration. 11. The controller of a touch device for identifying a drag gesture as defined in claim 8, wherein the gesture unit generates the drag signal once the first appearance time duration is greater than a first minimum tap reference time value. 12. The controller of a touch device for identifying a drag gesture as defined in claim 8, wherein the gesture unit generates the drag signal when the second appearance time duration is larger than the second minimum tap reference time. 13. The controller of a touch device for identifying a drag gesture as defined in claim 8, wherein the gesture unit generates the drag signal once the time span is greater than the first minimum UP reference time. 14. The controller of a touch device for identifying a drag gesture as defined in claim 8, wherein the controller further includes a transmitter interface connected to the gesture unit for transmitting the drag signal to a main unit. 15. A gesture unit of the touch device for identifying movement of an object on the touch device; wherein the gesture unit receives from the touch device a first tap signal and a second tap signal generated corresponding to a first and second appearances of the object on the touch device respectively, computes a sum of a first appearance time duration and a time span between an end of the first appearance and a start of the second appearance and compares the sum with the a first reference time and in case of the sum being smaller than the first reference time value, a determination is done after one of two following conditions being met and the gesture unit generates a corresponding drag gesture: A) If the sum of the first appearance time duration, the time span is not less than a reference time value; and B) If an accumulated displacement of the second appearance time duration is not less than a reference displacement. 16. The gesture unit of the touch device as defined in claim 15, wherein the drag signal is generated once the sum of the first appearance time duration, the time span and the second appearance time duration is greater than the reference time value. 17. The gesture unit of the touch device as defined in claim 15, wherein the drag signal is generated once the accumulated displacement of the second appearance time duration is not less than the reference displacement. 18. The gesture unit of the touch device as defined in claim 15, wherein the drag signal is generated in case of the first appearance time duration is greater than the first minimum tap reference time. 19. The gesture unit of the touch device as defined in claim 15, wherein the drag signal is generated in case of the second appearance time duration is greater than a second minimum tap reference time. 20. The gesture unit of the touch device as defined in claim 15, wherein the drag signal is generated in case of the time span is greater than a first minimum raised up reference time. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a controller for identifying a drag gesture and particularly to a method and a controller for identifying a drag gesture on a touch device and generating a drag signal, which simulates an object dragged by a mouse. 2. Description of Related Art The graphical user interface (GUI) is a program operational interface developed by ZEROX PARC research center and the GUI is used in company with a pointing device such as a mouse. The user only needs to move the mouse with a visional type pointer and make a click then a desired action can be performed easily so as to solve the problem of inconvenience resulting from the text mode being required to input complicated instructions. Hence, the GUI was adopted by Apple computer company and Microsoft company one after another to become the most popular mode in all the operational systems. The pointing device has become a basic outfit in electronic equipment applying the GUI such as desktop computer, notebook computer, flat panel computer and personal digital assistance (PDA). Currently, the pointing device includes external mouse and a track ball touch pad built in a portable computer system and a touch panel joined to the screen. The mouse is the earliest developed pointing device. Taking the mouse as an example for explaining the function of pointing device, the mouse can control the pointer on the screen of the electronic device, that is, where the mouse is moved, where the pointer is moved. Then, an execution instruction to the electronic device can be carried out by way of pressing the control button on the screen for a target ready to be executed. Nevertheless, design with lightness, smallness, shortness and thinness is a trend of electronic equipment and, for instance, the laptop computer is getting to replace the desktop computer so that the small sized touch device such as the touch panel is getting a main stream pointing device gradually. The technique of current touch pad mainly includes capacitance type, resistance type, electromagnetic type, pressure type, inductance type, surface sound wave type and optical type. When a object body such as a finger moves on the touch pad, the pointer can be controlled to move along direction of the object body. Further, the pointer needs to have a function of carry out an order in addition to controlling movement of the pointer. Taking operating the mouse as an example, when the pointer moves to an object ready to be moved such as a program, a document or a picture, one of the buttons on the mouse such as the left button can be kept pressing in company with moving the mouse. In this way, the object can be dragged to other places. As for the touch device such as the touch pad, mostly there are two control buttons provided additionally instead of the left and right buttons on the mouse or the object body is defined to make a certain gesture on the touch device such that signals resulting from continuing pressing a button of the mouse can be generated along with the object being moved and dragged to other places. An ordinary touch device usually simulates a drag movement of mouse with a drag gesture and the way to carry out the drag gesture is to implement a tap and a displacement following the tap immediately so as to let the object moving. Hence, U.S. Pat. No. 6,414,671 has disclosed a method for identifying a drag gesture on the touch device. With reference to FIG. 1, when a time duration t4 of the object body appearance at the first time (i.e. stay time of the object body appearing on the touch device at the first time) is compared to the first reference time value, a drag signal 11 generates in case of the time duration t4 being less than a first reference time value. Then, a time span t5 between the first time appearance and the second time appearance is compared to a second reference time value and the drag signal 11 is kept and X, Y information generates repeatedly within the time duration t5 at the second time in case of the time span t5 being less than the second reference time value. Although the conventional method can achieve the purpose of identifying the drag gesture, the time duration t4 of first appearance and the time span t5 between the first appearance and the second appearance being compared to a respective reference time value corresponding to them makes determination complicated. Also, X, Y information being generated repeatedly within the time duration t6 of the second appearance results in more complicated design. Further, due to personal differences between users, time for various stages of movement done by each person during performing the drag gesture may be different from each other. Even the same person may have different time durations for movements while the drag gesture is performed at different times. Hence, it is easy for the conventional method to occur misjudgment. In addition, it is easy for the touch device to be touched accidentally during operation or to occur phenomena of temporary spike of the first appearance, temporary spike time span between the first appearance and the second appearance and temporary spike of second appearance due to the touch device generating noise at work or being caused by interference of foreign noise. The conventional method does not have a minimum time limitation to the time duration of first appearance, the time duration of second appearance and the time span between the first appearance and the second appearance so that it is easy to occur incorrect determination to the signal generated due to the noise interference. SUMMARY OF THE INVENTION An object of the present invention is provide a method and a controller for identifying a drag gesture with which a time summation of each movement is compared to a reference time value to achieve a more convenient and reliable determination. Another object of the present invention is to provide a method for identifying a drag gesture with which time of each movement is required to be greater than a corresponding time value respectively so as to avoid a misjudgment effectively caused by noise. A further object of the present invention is to provide a method and a controller for identifying a drag gesture with which an accumulated displacement during the second appearance is compared to a reference displacement so as to determine if the drag gesture is performed and achieve an accurate judgment. The method of identifying a drag gesture with which the drag gesture is performed on a touch device according the present invention includes follow steps: i. detecting a first appearance of an object on the touch device; ii. detecting a second appearance of the object on the touch device; and iii. a sum of time duration of the first appearance and time span between an end of the first appearance time duration and a start of the second appearance being smaller than a first reference time and meeting one of following two situation, then generating a drag signal: (A) another summation of the first appearance time duration, the time span and a second appearance time duration being not less than the reference time value; and (B) an accumulated displacement of the second appearance time duration being not less than a reference displacement. BRIEF DESCRIPTION OF THE DRAWINGS The present invention can be more fully understood by reference to the following description and accompanying drawings, in which: FIG. 1 is a graph showing time pulse of conventional drag gesture; FIG. 2 is a block diagram of a touch device in a preferred embodiment of a method of identifying drag gesture according to the present invention; FIG. 3 is a flow chart of the embodiment shown in FIG. 2; FIG. 4 is a graph showing time pulses of input and output signals in an example of the embodiment shown in FIG. 2; and FIG. 5 is a graph showing time impulses of input and output signals in another example of the embodiment shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Regarding the previously mentioned technical details, characteristics and effectiveness of the present invention, it can be fully understood by referring to the reference figures in the detailed explanation of the preferred embodiment of the present invention. To start off, the method of identifying drag gesture according to the present invention is to be used on touch device. For explanation purpose, in the preferred embodiment of the invention, the capacitance type touch device is used for explanation. Referring to FIG. 2, capacitance type touch device 2 mainly includes a touch pad 21, an operation module that consists of a treat unit along X direction 22, a treat unit along Y direction 23, an operational unit 24 and a displacement unit 25, a gesture unit 26 and a transmitter interface 27. The touch pad 21 has multiple wires distributed in the X and Y direction respectively and, for example, there are 16 wires in the X direction and 12 wires in the Y direction. Therefore, when a conductive object such as a finger 10 touches or in close contact with the touch pad 21, it causes a change in the capacitance on the touch pad 21. The treat units along X and Y direction 22, 23 immediately process the respective capacitance on the X and Y direction and transmit the data to operational unit 24. The operational unit 24 based on the received data will compute the X and Y coordinates of the object contact location. After that, the displacement unit 25 will receive the X and Y coordinates computed by the operational unit 24 and based on this information calculate relative displacements Dx and Dy corresponding to the contact signal of the object on the touch pad 21 and transmit them to the gesture unit 26 and transmitter unit 27. Thus, the calculated results Dx and Dy can be transmitted to a main unit 3 through the transmitter unit 27 so that the main unit 3 can control the movement of the pointer on the screen. Main unit 3 can be a personal computer, laptop, personal digital assistant (PDA) or a cellular phone. In here, the previous mentioned components are related to the prior art and no detailed will be described further. Furthermore, the operational module, displacement unit 25, gesture unit 26 and transmitter interface 27 in the preferred embodiment of present invention are all assembled in a controller such as a chip. The gesture unit 26 receives the calculation results Dx and Dy from the displacement unit 25 to determine if the object has produced an action qualified as a drag gesture on the touch pad 21 and also during this determination as whether the action is a drag gesture, correspondingly transmits out the first signal of the simulated dragging the mouse while holding the mouse button (this drag signal comprises of multiple consecutive signals), through the transmitter interface to the main unit 3 in order to carry out the corresponding control. The technical characteristic of the present invention is the method of identifying drag gesture in the gesture unit 26. The gesture unit 26 can achieve the method of identifying drag gesture through software, firmware or hardware. Moreover, even though the gesture unit 26 in the example of the present invention is embedded in the controller of the touch device 2, it can be installed in the main unit 3 as a software or hardware and not just limited to technique used or revealed in the preferred embodiment of the present invention. Besides, even though a capacitance type touch device 2 is used as an example in the preferred embodiment of the present invention, persons familiar to the art should know that the present invention can be applied onto other types of touch device, such as optical type, resistance type, magnetic type, pressure type, inductance type, surface sonar type, supersonic type and so on. Therefore, it is not confined to just what is illustrated or revealed in the preferred embodiment of the present invention. Referring to FIG. 3, it illustrates the flow chart of an example in the preferred embodiment of the present invention. In the example, first assume that an object such as a finger 10 has simultaneously tapped on the touch pad 21 twice. To simplify the explanation, in the following paragraphs, the object will be represented by the finger 10. Something worth noting is that even though a finger 10 is used to illustrate the preferred embodiment of the present invention, persons familiar with the conventional art should know that the touch device 2 of the preferred embodiment is suitable for detecting other types of conductive objects or multiple conductive objects, which are not confined to what is revealed in the preferred embodiment of the present invention. First of all, in step 41, the touch device 2 detects the finger 10 on the touch pad 21 at the start of its first appearance. At the same time, the touch device 2 will start timing how long the finger 10 appears on the touch pad 21. In the present example, if it is assumed to be the drag gesture, there will be a detection of a second appearance within the first reference time value T1. The range of the first reference time value T1 in the present example can be set between 100 ms˜1000 ms (100 ms≦T1≦1000 ms) or it can be adjusted according to the need of the designer or the operating preference of the user. Subsequently, in step 42, the touch device will continued to detect the appearance of the finger 10 on the touch pad 21 in order to determine which of the two conditions: the ending of the first appearing time duration or the timer after the first appearing time duration has reached the first reference time T1, has been achieved first. If in step 42, it has been determined that first appearing time duration has ended and the timer has not reached the first reference time T1 which means that there may be a second appearance within the first reference time T1, step 44 will continue to be executed. However, if in step 42, it has been determined that the timer has reached the value of first reference time T1, and as only the first appearance occurred within the first reference time T1 and the first appearing time duration Tdown1 exceeds the first reference time T1, it can be confirmed that it is not a drag gesture Thus step 43 will be executed by the gesture unit 26 to determine if the action is of any other gestures. In step 44, touch device 2 continues to determine which of the conditions: the start of the second appearance time duration when the finger 10 is detected on the touch pad 21 or the timer has reached the first reference time T1, has been achieved first. If in step 44, it has been determined that the start of the second appearance time duration is detected first, it implies that two appearances have occurred within the first reference time T1 and it may be a drag gesture so step 45 will be continued. However, if in step 44, it has been determined that the timer has reached the value of first reference time T1 first, it can be confirmed that it is not a drag gesture. Thus step 43 will be executed to determine if the action is of any other gestures. If in step 44, it has been determined that second appearance has already started, referring to FIG. 4, touch device 2 has already obtained the first appearance time duration Tdown1 (referring to the time the finger 10 is maintained on the touch pad when it first appearance on the touch pad) and also the time span between the two appearance time durations Tup1 (referring to the time when the finger 10 first taps and leaves the touch pad until the time before the finger 10 taps on the touch pad 21 for the second time) in the previous detection. Touch pad 21 during its operation can be easily touched by mistake or due to the noise generated by itself or noise from the surrounding environment and then produce inappropriate signals such as short first and second appearance time duration or short time span between the two appearance time duration. As these unwanted signals only last a short period of time, there is a requirement that the time duration of each action must be larger than the respective minimum time values, in order to effectively filter out inappropriate signals and thus enhance the accuracy of the identification. Therefore, in step 45, first determine if the first time span Tup1 between the first appearance time duration T1 and the second appearance time duration T2 is larger than the first minimum UP reference time T21. The first minimum UP reference time T21 is the shortest effective time between the UP and DOWN of the finger 10. In the present example, the first minimum UP reference time T21 ranges from 1 ms to 10 ms (1 ms≦T21≦10 ms) and it can be adjusted according to the need of the designer or the operating preference of the user. If step 45 determines the first time span Tup1 to be not larger than the first minimum UP reference time T21 (Tup1≦T21), it represents that the signal of the first time span Tup1 is too short so the first appearance actually has not really finished yet and thus it will jump back to step 42. If step 45 determines that the first time span Tup1 is larger than the first minimum UP reference time T21 (Tup1>T21) it implies that the first time span between the two appearance durations is valid and therefore continues to step 46. In step 46, determine if the first appearance time duration Tdown1 is larger than the first minimum tap reference time T31. Since usually when the finger 10 appearing on the touch pad 21 implies that the finger 10 is down on the touch pad 21, then the shortest effective time the finger 10 first tap on the touch pad 21 and stays on it is called the first minimum tap reference time T31. If in step 46, it is determined that the first appearance time duration Tdown1 is larger than the first minimum tap reference time T31 (Tdown1>T31), it indicates that the first appearance is a valid signal and step 47 will be continued. However, if step 46 determines the condition to be false (Tdown1≦T31), which implies that the first appearance is a noise signal and will be discarded, it will jump back to step 41 and resume to wait for the next first appearance. When proceeding to step 47, it implies that the summation of the first appearance time duration Tdown1 and the first time span between two appearance durations is smaller than the first reference time value T1. During the drag gesture, it is just that the second appearance of finger 10 on the touch pad 21 lasts longer, or the accumulated displacement of the second appearance time duration is larger, therefore, in the preferred embodiment of the present invention, time and displacement will be used as condition to determine whether it is drag gesture and enhance the determination reliability. In step 47, determines which of the following three conditions is achieved first: detection of the finish of the second appearance time duration, the accumulated displacement of the second appearance time duration Mdown2 is larger than the reference displacement value M1 or the timer since the first appearance time duration has reached the first reference time T1. The gesture unit 26 besides resuming the timer for the detection of the second appearance, it uses the result Dx and Dy from the displacement unit 25 to calculate the accumulated displacement of the second appearance time duration Mdown2. If in step 47, the finish of the second appearance time duration is detected first, the second appearance time duration Tdown2 and the second time span after the end of the second appearance and before the UP of the finger 10 Tup2 will be obtained. At this time, if it is confirmed that the second time span Tup2 and the second appearance time duration Tdown2 are valid signals and implies that within the first reference time T1, two appearance have really been detected and the accumulated displacement of the second appearance time duration Mdown2 is less than the reference displacement value M1 (Mdown2<M1). Thus, it can be determined it is not drag gesture. Therefore, step 47 determines the detection of finish of the second appearance occurred first, step 48 and 49 will be continue to determine if the second time span Tup2 and the second appearance time duration Tdown2 are valid signals. In step 48, determine if the second time span Tup2 is larger than the second minimum UP reference time T22. The range of the second minimum UP reference time T22 in the present example can be set between 1 ms˜10 ms (1 ms≦T22≦10 ms) or it can be adjusted according to the need of the designer or the operating preference of the user. If step 48 determines that is the second time span Tup2 is larger than the second minimum UP reference time T22 (Tup2>T22), it implies that the second time span Tup2 is a valid signal and then proceed the determination in step 49. If step 48 determines that the second time span Tup2 is not larger than the second minimum UP reference time T22 (Tup1≦T22), it implies that the signal of the second time span Tup2 is just noise signal and thus will be discarded and jump back to step 47. In the present example, the second minimum UP reference time T22 can be set to be the same as the first minimum UP reference time T21. In step 49, determines if the second appearance time duration Tdown2 is larger than the second minimum tap reference time T32. If step 49 determines the second appearance time duration Tdown2 is larger than the second minimum tap reference time T32 (Tdown2>T32), thus it indicates the signal of the second appearance is a valid signal and therefore not a drag gesture so it will jump back to step 43 to continue to determine if it is of any other gestures. However, if step 49 determines that the second appearance time duration Tdown2 is not larger than the second minimum tap reference time value T32 (Tdown2≦T32), it implies that the second appearance is a noise signal so it will be discarded and jump back to step 44 to wait if the second appearance time duration has really started. In the present example, the second minimum tap reference time T32 can be set to be the same as the first minimum tap reference time T31. If in step 47, it is determined first that the timer since the start of the first appearance has reached the first reference time value T1, it can be confirmed that the second appearance to be valid signal and determined that the two appearances are due to drag gesture, so step 50 will be executed in order to determine if the second appearance is a valid signal. In step 50, determine if the second appearance time duration Tdown2 is larger than the second minimum tap reference time value T32. If step 50 determines that the second appearance time duration Tdown2 is larger than the second minimum tap reference time T32 (Tdown2>T32), implies that the second appearance is a valid signal and if the summation of the first appearance time duration Tdown1, time span between the two appearance time duration Tup1 and the second appearance time duration Tdown2 is not smaller than the first reference time T1 [(Tdown1+Tdown2+Tup1)<T1], thus gesture unit 26 will output a drag signal through the transmitter interface 27 into the main unit 3 to notify the main unit that a drag gesture has been produced and simulate the drag signal produced by moving the mouse while holding the mouse button. If in step 50, it is determined that the second appearance time duration Tdown2 is not larger than the second minimum tap reference time T32, implies that the second appearance is noise, but since the timer from the start of the first appearance has reached the first reference time value T1, it will jump back to step 43 to determine if the action is of any other gesture. If in step 47, it is determined first that the accumulated displacement of the second appearance time duration Mdown2 is larger than the reference displacement M1 (Mdown2≧M1), it implies that even though the overall time durations of the two tap is relative short but the second tap (which is the second appearance) is dragging on the touch pad 21, the user is carrying out these action for the purpose of dragging so step 51 will be executed as in FIG. 5 to produce the drag signal. The range of the reference displacement M1 in the present example can vary between 1 pixel and 10 pixel (1 pixel≦M1≦10 pixel), such as 3 pixel or it can be adjusted according to the need of the designer or the operating preference of the user. According to what is claimed previously and also differing from the convectional method where the drag signal is produced immediately after the first tap, referring to FIG. 4, when the summation of the first and second appearance time durations and the time span between the two appearance time durations is larger or equal to the first reference time value T1, [(Tdown1+Tdown2+Tup1)≧T1], and after the accumulated time from the start of the first appearance has reached the first reference time value T1, only then the drag signal will be output. Besides this, referring to FIG. 5, when the summation of the first and second appearance time durations and the time span between the two appearance time durations is less than the first reference time value T1, [(Tdown1+Tdown2+Tup1)<T1], but the accumulated displacement of the second appearance time duration Mdown2 is not smaller than the first reference displacement M1, then during the second appearance, when the accumulated displacement is not less than the reference displacement, output the drag signal as in step 51. Summarising the previous claims, the requirement for the drag gesture in the preferred embodiment of the present invention is defined by the following equations: Tdown1>T31 Eq. 1: Tdown2>T32 Eq. 2: Tup1>T21 Eq. 3: Tup1>T22 Eq. 4: Tdown1+Tup1)<T1; and a. Tdown1+Tdown2+Tup1)≧T1; or b. Mdown2≧M1 It should be noted that even the previous mentioned steps 42, 44 and 47 can simultaneously determine multiple conditions. The person familiar with the convectional arts should know that the previous mentioned steps 42, 44 and 47 can also determine the conditions sequentially, so it is not just limited to what has been revealed in the preferred embodiment of the present invention. According to what is claimed previously and also differing from the convectional method where the time of the first appearance time duration and the first and second time span has to be respectively determined if they are smaller than their corresponding reference values and within the second appearance time duration, the X and Y information has to be output externally to be the calculation basis. The method of identifying drag gesture according to the present invention does not need to output X, Y information but take into account of the summation of the time for each action, Tdown1, Tdown2, Tup1 and to determine if it is less than the first reference time value T1 (refer to Eq. 5a), or determine that the accumulated displacement of the second appearance time duration Mdown2 is not less than the reference displacement M1 (refer to Eq. 5b), in order to achieve a fast and reliable determination. Moreover, the present invention further requires that the time duration of each action has to be larger than their respective reference values T31 (refer to Eq. 1), T21 (refer to Eq. 2) and T22 (refer to Eq. 4) so as to effectively filter out the inappropriate signals generated due to disturbance and thus achieve a more accurate determination. In addition, the present invention also takes the advantage of the whether the accumulated displacement of the second appearance time duration Mdown2 is not smaller than reference displacement M1 to determine if it is a drag gesture (refer to Eq. 5b), this will enhance the user's operation, and further achieve a more accurate determination. While the invention has been described with reference to the a preferred embodiment thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a method and a controller for identifying a drag gesture and particularly to a method and a controller for identifying a drag gesture on a touch device and generating a drag signal, which simulates an object dragged by a mouse. 2. Description of Related Art The graphical user interface (GUI) is a program operational interface developed by ZEROX PARC research center and the GUI is used in company with a pointing device such as a mouse. The user only needs to move the mouse with a visional type pointer and make a click then a desired action can be performed easily so as to solve the problem of inconvenience resulting from the text mode being required to input complicated instructions. Hence, the GUI was adopted by Apple computer company and Microsoft company one after another to become the most popular mode in all the operational systems. The pointing device has become a basic outfit in electronic equipment applying the GUI such as desktop computer, notebook computer, flat panel computer and personal digital assistance (PDA). Currently, the pointing device includes external mouse and a track ball touch pad built in a portable computer system and a touch panel joined to the screen. The mouse is the earliest developed pointing device. Taking the mouse as an example for explaining the function of pointing device, the mouse can control the pointer on the screen of the electronic device, that is, where the mouse is moved, where the pointer is moved. Then, an execution instruction to the electronic device can be carried out by way of pressing the control button on the screen for a target ready to be executed. Nevertheless, design with lightness, smallness, shortness and thinness is a trend of electronic equipment and, for instance, the laptop computer is getting to replace the desktop computer so that the small sized touch device such as the touch panel is getting a main stream pointing device gradually. The technique of current touch pad mainly includes capacitance type, resistance type, electromagnetic type, pressure type, inductance type, surface sound wave type and optical type. When a object body such as a finger moves on the touch pad, the pointer can be controlled to move along direction of the object body. Further, the pointer needs to have a function of carry out an order in addition to controlling movement of the pointer. Taking operating the mouse as an example, when the pointer moves to an object ready to be moved such as a program, a document or a picture, one of the buttons on the mouse such as the left button can be kept pressing in company with moving the mouse. In this way, the object can be dragged to other places. As for the touch device such as the touch pad, mostly there are two control buttons provided additionally instead of the left and right buttons on the mouse or the object body is defined to make a certain gesture on the touch device such that signals resulting from continuing pressing a button of the mouse can be generated along with the object being moved and dragged to other places. An ordinary touch device usually simulates a drag movement of mouse with a drag gesture and the way to carry out the drag gesture is to implement a tap and a displacement following the tap immediately so as to let the object moving. Hence, U.S. Pat. No. 6,414,671 has disclosed a method for identifying a drag gesture on the touch device. With reference to FIG. 1 , when a time duration t 4 of the object body appearance at the first time (i.e. stay time of the object body appearing on the touch device at the first time) is compared to the first reference time value, a drag signal 11 generates in case of the time duration t 4 being less than a first reference time value. Then, a time span t 5 between the first time appearance and the second time appearance is compared to a second reference time value and the drag signal 11 is kept and X, Y information generates repeatedly within the time duration t 5 at the second time in case of the time span t 5 being less than the second reference time value. Although the conventional method can achieve the purpose of identifying the drag gesture, the time duration t 4 of first appearance and the time span t 5 between the first appearance and the second appearance being compared to a respective reference time value corresponding to them makes determination complicated. Also, X, Y information being generated repeatedly within the time duration t 6 of the second appearance results in more complicated design. Further, due to personal differences between users, time for various stages of movement done by each person during performing the drag gesture may be different from each other. Even the same person may have different time durations for movements while the drag gesture is performed at different times. Hence, it is easy for the conventional method to occur misjudgment. In addition, it is easy for the touch device to be touched accidentally during operation or to occur phenomena of temporary spike of the first appearance, temporary spike time span between the first appearance and the second appearance and temporary spike of second appearance due to the touch device generating noise at work or being caused by interference of foreign noise. The conventional method does not have a minimum time limitation to the time duration of first appearance, the time duration of second appearance and the time span between the first appearance and the second appearance so that it is easy to occur incorrect determination to the signal generated due to the noise interference. | <SOH> SUMMARY OF THE INVENTION <EOH>An object of the present invention is provide a method and a controller for identifying a drag gesture with which a time summation of each movement is compared to a reference time value to achieve a more convenient and reliable determination. Another object of the present invention is to provide a method for identifying a drag gesture with which time of each movement is required to be greater than a corresponding time value respectively so as to avoid a misjudgment effectively caused by noise. A further object of the present invention is to provide a method and a controller for identifying a drag gesture with which an accumulated displacement during the second appearance is compared to a reference displacement so as to determine if the drag gesture is performed and achieve an accurate judgment. The method of identifying a drag gesture with which the drag gesture is performed on a touch device according the present invention includes follow steps: i. detecting a first appearance of an object on the touch device; ii. detecting a second appearance of the object on the touch device; and iii. a sum of time duration of the first appearance and time span between an end of the first appearance time duration and a start of the second appearance being smaller than a first reference time and meeting one of following two situation, then generating a drag signal: (A) another summation of the first appearance time duration, the time span and a second appearance time duration being not less than the reference time value; and (B) an accumulated displacement of the second appearance time duration being not less than a reference displacement. | 20040706 | 20070227 | 20060112 | 66137.0 | G09G500 | 14 | OSORIO, RICARDO | METHOD AND CONTROLLER FOR IDENTIFYING A DRAG GESTURE | SMALL | 0 | ACCEPTED | G09G | 2,004 |
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10,777,106 | ACCEPTED | Vehicular door | A door for a motor vehicle includes an outer panel and an inner panel in which window portions are formed at their upper side region and which are connected at their peripheral portions, a space which is formed between the lower side region of the outer panel and the lower side region of the inner panel and in which a window glass for opening and closing the window portions is disposed so as to be able to move up and down, a module mounting opening formed on the lower side region of the inner panel and a module structure constituted by mounting a plural functional components to a module base, wherein the module base is fluid-tightly fixed to the module mounting opening at its peripheral portion and the module structure is mounted on the inner panel. | 1. A door for a motor vehicle comprising: an outer panel and an inner panel in which window portions are formed at their upper side-region and which are connected at their peripheral portions, a space which is formed between the lower side region of the outer panel and the lower side region of the inner panel and in which a window glass for opening and closing the window portions is disposed so as to be able to move up and down, a module mounting opening formed on the lower side region of the inner panel and a module structure constituted by mounting a plural functional components including at least a remote control mechanism for transmitting a movement of an inside handle operated for opening and closing the door to a latch mechanism for maintaining the door in closing state by engaging the door with a body to the inside of compartment of a module base, wherein the module base is fluid-tightly fixed to the module mounting opening at its peripheral portion and the module structure is mounted on the inner panel. 2. A door for a motor vehicle as recited in claim 1, wherein the inside handle is mounted at the inside of the compartment of the module base and is connected to the remote control mechanism. 3. A door for a motor vehicle as recited in claim 1, wherein the remote control mechanism includes an engagement mechanism for being intermittent a path transmitting the movement of the inside handle to the latch mechanism, and a locking actuator connected to the engagement mechanism and for operating the engagement mechanism is mounted at the inside of the compartment of the module base. 4. A door for a motor vehicle as recited in claim 1, wherein the door is a sliding type door and the remote control mechanism transmits the movement of the inside handle to a front side latch mechanism and a rear side latch for maintaining the door in closing state by engaging the door with the body for moving the front side latch mechanism and the rear side latch mechanism to a door opening allowed position. 5. A door for a motor vehicle as recited in claim 1 further comprising a link mechanism for supporting the window glass and for moving up and down the window glass and disposed at the outside of the compartment of the module base, a moving up and down actuator for driving the link mechanism and mounted at the inside of the compartment of the module base, an output member penetrating the module base and disposed at the outside of the compartment and a drive shaft for driving the link mechanism and rotatably supported on the module base, wherein the drive shaft is connected to the link mechanism at the outside of the compartment and is connected to the output member for constituting a window regulator. 6. A door for a motor vehicle as recited in claim 1, wherein the module base is overlapped with the module mounting opening of the inner panel at the peripheral portion from the inside of the compartment and a hole for fitting a connecting member is extended upward and downward and is formed so as to isolate regionally the inner panel from the module base at a portion in which an upper side edge of the module mounting opening is located lower than an upper side edge of the module base. 7. A door for a motor vehicle as recited in claim 1, wherein a communicating hole is formed on the module base and a step portion which projects to the outside of the compartment is formed at the upper portion of the communicating hole, and a block in which a projection overlapping with the step portion is formed is fixed to the module base so as to close fluid-tightly the communicating hole by its peripheral portion and a hole for fitting a connecting member is formed on the projection upward and downward. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door for a motor vehicle. 2. Description of the Related Art As a conventional door for a motor vehicle, particularly a conventional sliding door for a motor vehicle, a door stated in “Estima T/L Service manual” issued on January 2000 by TOYOTA MOTOR CORPORATION is known. As shown in FIG. 16 and FIG. 17, in this door, an outer panel having a window portion formed at its upper side region and an inner panel having a window portion formed at its upper side portion are opposed and are connected at their peripheral portions and a space is formed between the lower side region of the outer panel and the lower side region of the inner panel and a window glass which opens and closes the window portions is disposed in the space so as to be able to move up and down. An inside handle 1 operated for opening and closing the door, a remote control mechanism 5 for transmitting the movement of the inside handle 1 and an outside handle 4 to pole members of latch mechanism 2, 3 for maintaining the door in a closing state by engaging the door with a body, a locking actuator for operating an engagement and disengagement mechanism provided on the remote control mechanism 5 for being intermittent a path transmitting the movement of the inside handle 1 and the outside handle 4 to the pole members and so on are mounted at the inside of the inner panel, and a window regulator 7 for moving up and down the window glass and the latch mechanisms 2, 3 are mounted at the outside of inner panel. In the prior sliding door for a vehicle, as mentioned above, since a great number of functional components are mounted on the inner panel through brackets, the number of man-hour in assembling process of a vehicle and the number of part increase and the weight of the door and the cost increase. Further, since a moving up and down actuator 8 of the window regulator 7 is mounted at the outside of the inner panel, the waterproofing becomes insufficient and there was a case that the insufficient waterproofing causes a malfunction of the moving up and down actuator 8 which is an electrical part. SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicular door which can prevent the prior drawbacks. According to the present invention, a vehicular door includes an outer panel and an inner panel in which window portions are formed at their upper side region and which are connected at their peripheral portions, a space which is formed between the lower side region of the outer panel and the lower side region of the inner panel and in which a window glass for opening and closing the window portions is disposed so as to be able to move up and down, a module mounting opening formed on the lower side region of the inner panel and a module structure constituted by mounting a plural functional components including at least a remote control mechanism for transmitting a movement of an inside handle operated for opening and closing the door to a latch mechanism for maintaining the door in closing state by engaging the door with a body to the inside of compartment of a module base, wherein the module base is fluid-tightly fixed to the module mounting opening at its peripheral portion and the module structure is mounted on the inner panel. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a door for a motor vehicle in which a trim is removed according to the present invention; FIG. 2 is a partial sectional side view of the door for a motor vehicle; FIG. 3 is a front view of a module structure; FIG. 4 is a cross-sectional view of an inside handle; FIG. 5 is a front view of a remote control mechanism; FIG. 6 is a sectional side view of the remote control mechanism; FIG. 7 is a diagram showing a mounting condition of a bracket to a module base; FIG. 8 is a diagram showing a mechanism for transmitting a movement of an outside handle to a cable; FIG. 9 is a diagram showing a condition in which the cable is introduced into the inside of compartment through a hole of the module base; FIG. 10 is a diagram showing a condition in which a link is derived to the outside of compartment through a hole formed on the module base; FIG. 11 is a diagram showing the remote control mechanism which is looked from its back face side; FIG. 12 is an enlarged view of an actuator part of a window regulator and a drive shaft part; FIG. 13 is a sectional view of a mounting portion of the actuator part of the window regulator and the drive shaft part to the module base; FIG. 14 is a front view of the module structure in which an electric supply device is mounted to the module base; FIGS. 15(a) to 15(c) is a diagram showing a modification of a seal which waterproofs an end portion of the cable transmitted a movement of the outside handle; FIG. 16 is a diagram showing a prior sliding door; and FIG. 17 is a diagram showing a mounting of a window regulator of the prior sliding door. DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, a preferred embodiment of the present invention will be explained referring to drawings. FIG. 1 is a front view of a sliding type door 10 for a motor vehicle in which a trim is removed according to the present invention. FIG. 2 is a partial sectional side view of the sliding door 10 for a motor vehicle. FIG. 3 is a front view of a module 22 in which a plural functional components are mounted to a module base 21. As shown in FIG. 1 to FIG. 3, a window portion 15 penetrates an upper side region 14 of a door main body 13 which is formed by connecting between an outer panel 11 and an inner panel 12 at their peripheral portions and is provided. In a lower side region 19, a space 17 in which a window glass 16 for opening and closing the window portion 15 is disposed so as to be able to move up and down is formed between the outer panel 11 and the inner panel 12. The numeral 18 is a trim which is mounted at the inside of a compartment of the door main body 13. There is a case that water enters from outside of vehicle to the outside of a compartment which is outside of the inner panel 12, but water does not enter to the inside of the compartment which is inside. A horizontally long module mounting opening 20 is formed near the window portion 15 at the lower side region 19 of the inner panel 12. A peripheral portion of a module base 21 is overlapped with a peripheral portion of the module mounting opening 20 and is fluid-tightly fixed thereto through a seal, and a module structure 22 constituted by mounting a plural functional components to the module base 21 is fixed to the inner panel 12 from the inside of the compartment. As shown in FIG. 3, the module structure 22 is constituted by mounting a inside handle 23 for opening and closing the sliding door 10, a front side latch mechanism 24 for maintaining the sliding door 10 in a closing state by engaging the sliding door 10 with a body, a remote control mechanism 28 for transmitting the movement of the inside handle 23 and an outside handle 27 to pole members of the front side latch mechanism 24 and a rear side latch mechanism 25, a locking actuator 30 for engaging and disengaging an engagement mechanism 29 provided on the remote control mechanism 28 for being intermittent a path transmitting the movement of the inside handle 23 and the outside handle 27 to the pole members of the front side latch mechanism 24 and the rear side latch mechanism 25, a release actuator 31 for entering the movement to the remote control mechanism 28 for moving the pole members of the front side latch mechanism 24 and the rear side latch mechanism 25 to a door opening allowed position, a window regulator 32 for moving up and down the window glass 16 and so on to the module base 21. On the inner panel 12, besides the module structure 22, the rear side latch mechanism 25 which engages the sliding door 10 with the body and which maintains the sliding door 10 in the door closing state, a power sliding door driving, unit 33 for opening and closing automatically the sliding door 10, an electric supply device 34 for supplying the electric power from the body side to each actuator mounted on the sliding door 10, a computer 35 for controlling the operations of each actuators and so on are mounted. The outside handle 27 is mounted on the outer panel 11. As shown in FIG. 4, a base 36 of the inside handle 23 nips the module base 21 between both side wall bottom surface and a head portion of a screw 37 screwed into a bottom surface and is mounted on a front side upper portion of the inside of the compartment of the module base 21. As shown in FIG. 9, a handle 23a of the inside handle 23 is pivoted on the base 36 so as to be able to swing. Further, a connecting bar 38 projected and provided on a locking knob 23b of the inside handle 23 is connected to the remote control mechanism 28 through a link mechanism 39 constituted by an output lever of the locking actuator 30 and a locking lever of the remote control mechanism 28. The front side latch mechanism 24 for maintaining the sliding door 10 in the closing state by engaging the sliding door 10 with the body is fixed to a front side lower of the outside of the compartment of the module base 21 by a bracket 40. When a latch of the front side latch mechanism 24 engages with an engaging clasp fixed to the body side under the door closing state of the sliding door 10, the pole member engages with the latch and blocks the rotation of the latch. The pole member is pivoted so as to be able to swing. In order to move the front side latch mechanism 24 to the door opening allowed position, the movement of the inside handle 23 is transmitted to the front side latch mechanism 24 through the remote control mechanism 28. Namely, the inside handle 23 and the outside handle 27 are connected to the pole member of the front side latch mechanism 24 through the remote control mechanism 28. When the opening movement of the inside handle 23 toward the opening direction of the door or the movement of the outside handle 27 is transmitted under the engaged condition of the engagement mechanism 29, the pole member is swung to the door opening allowed position allowing the rotation of the latch, and the latch is rotated and is free to disengage from the engaging clasp, and the sliding door 10 can move toward the opening direction. As shown in FIG. 5 and FIG. 6, an outside door opening lever 45a, an inside door opening lever 45b, a door closing lever 46, a first lift lever 47 and a second lift lever 48 are piled up and are rotatably fitted on a central axis 49, and are nipped, between a head portion of the central axis 49 and a nut 50 screwed on a screw portion and is pressed with an appropriate force by an elastic force of a disc spring 51. A top end portion 52 of the central axis 49 is cut off the edges and a screw is formed thereon. The top end portion 52 is fitted into a hole 44 formed on the module base 21 and a nut 59 is screwed through a washer, and the central axis 49 is prevented from rotating and is fixed to the module base 21. A torque spring 54 is disposed between the central axis 49 and the second lift lever 48 and urges the second lift lever 48 so as to rotate clockwise in FIG. 5. The numeral 53 is resinous bracket. As shown in FIG. 7, a T-shaped projection 54 formed on a back surface is fitted into a T-shaped hole 55 formed on the module base 21 while aligning a transversal line portion and is moved toward the upper end of, the longitudinal line of the hole 55, and both side portions and a lower end portion of the longitudinal line portion of the hole 55 are engaged with a slit having the same width as the thickness of the module base 21 which is formed on a foot of both side of the transversal line portion and the lower end of the longitudinal line portion of the T-shaped projection 54, the bracket 53 is contacted and fixed to the module base 21. A tension spring 56 which is disposed on a spring stopping portion of the bracket 53 urges the inside door opening lever 45b so as to rotate clockwise. The rotation of the inside door opening lever 45b clockwise is regulated by contacting a projection 162 with a stopper formed on the bracket 53. A tension spring 58 which is disposed on the spring stopping portion of the bracket 53 urges the door closing lever 46 so as to rotate clockwise. The rotation of the door closing lever 46 is regulated by contacting a projection 72 with the outside door opening lever 45a. The rotation of the outside door opening lever 45a is regulated by contacting with a stopper 57 made of resin. The stopper 57 is fixed to the module base 21 by the engagement of a T-shaped projecting portion with a T-shaped hole as same as the bracket 53. The opening movement of the inside handle 23 is transmitted to an end portion of a long hole 73 of the inside door opening lever 45b by a link 60 and the door closing movement of the inside handle 23 is transmitted to a door closing lever 46 by a link 43. A handle of the outside handle 27 which is disposed in the horizontal direction is pivoted on the outer panel 11 at its rear end portion so as to be able to swing and presses an arm portion 63 of a swing link 62 shown in FIG. 8 at its front end portion, and rotates the swing link 62. The swing link 62 is supported on a base 27a of the outside handle 27 by a pin 70 so as to be able to rotate around a horizontal axis and a wire 65 of a cable 64 is connected to a free end thereof from lower side. An upper end portion of a coating tube 66 of the cable 64 is fixed at the lower side of the free end of the swing link 62 by a cable stopper 74 fixed to the base 27a of the outside handle 27. A bottom portion of an accordion seal 67 is fluid-tightly fixed to the wire 65 and a skirt portion covers an upper end portion of the coating tube 66 for waterproofing. Since the seal 67 is opened at its lower end and comings and goings of air is free, the resistance to expansion and contraction is small and it is able to smoothly move the outside handle 27 by small force. Since the movement of the outside handle 27 can be transmitted to the cable 64, the cable 64 passes the front side of the window glass 16 in the space 17 and is introduced easily to the inside of the compartment through a hole 68 (FIG. 1) formed on the inner panel 12 or a hole 69 (FIG. 9) formed on the module base 21. In the holes 68, 69, grommets 75, 76 in which the cable 64 passes are mounted for waterproofing. The wire 65 of the cable 64 is connected to a long hole 77 of the outside door opening lever 45a of the remote control mechanism 28. The coating tube 66 is fixed by a cable stopper fixed to the module base 21 while being opposite to the long hole 77. The release actuator 31 is connected to a long hole 78 formed on the outside door opening lever 45a. A link 80 is pivoted on a top end of an arm 79 of the first lift lever 47. As shown in FIG. 10, the link 80 is derived to the outside of the compartment through a communicating hole 81 formed on the module base 21 and is connected to the pole member of the front side latch mechanism 24. Namely, a rectangular step portion 82 which projects to the outside of the compartment at its upper portion is formed on the module base 21 and a communicating hole 81 is formed on the step portion 82. A block 84 in which a projection 83 overlapping with the step portion 82 is formed is fixed to the module base 21 so as to close fluid-tightly the communicating hole 81 by its peripheral portion. A hole 26 penetrates the projection 83 upward and downward and the link 80 which is a connecting member is derived to the outside of the compartment through the hole 26. Since the hole 26 is formed at upper side with respect to the communicating hole 81 of the_module base 21 and is formed upward and downward at the outside of the compartment, water can be prevented from entering from the outside of the compartment to the inside of the compartment. The locking actuator 30 is mounted at the inside of the compartment of the block 84. A wire 86 of the cable 85 is connected to an upper end of the first lift lever 47 and a coating tube 87 is fixed to a cable stopper 88 formed on the bracket 53. As shown in FIG. 2, the cable 85 being a connecting member is derived to the outside of the compartment through a hole 89 formed between the inner panel 12 and the module base 21 and is connected to the pole member of the rear side latch mechanism 25. The hole 89 is extended upward and down ward and is formed so as to isolate regionally the inner panel 12 from the module base 21 at a portion in which an upper side edge of the module mounting opening 20 is located lower than an upper side edge of the module base 21. Since the hole 89 is formed upward and downward at the outside of the compartment so that the upper side edge of the module mounting opening 20 is located lower, water can be prevented from entering from the outside of the compartment to the inside of the compartment. Thereby, it is able to transmit the opening movement of the inside handle 23 for moving the rear side latch mechanism 25 for maintaining the sliding door 10 in the closing state by engaging the sliding door 10 with the body to a door opening allowed state or the movement of the outside handle 27 to the rear side latch mechanism 25 through the remote control mechanism 28. The rotation of the first lift lever 47 in clockwise is regulated by contacting a projection 160 of the first lift lever 47 to a stopper 161. An upper end of the door closing lever 46 is connected to a wire 91 of a cable 90 and a coating tube 92 is fixed to a cable stopper 88 formed on the bracket 53. The cable 90 is connected to a pole member of a latch mechanism (not shown) for maintaining the opened sliding door 10 in the opening state by engaging the sliding door 10 with the body. The engagement mechanism 29 for being intermittent the path transmitting the opening movement of the inside handle 23 and the movement of the outside handle 27 to the pole members of the front side latch mechanism 24 and the rear side latch mechanism 25 is provided on the remote control mechanism 28. Namely, as shown in FIG. 5, FIG. 6 and FIG. 11 showing the remote control mechanism which is looked from its back face side, a locking pin 94 is slidably disposed in a long hole 93 which is formed in the first lift lever 47 in the turning radial direction. The locking pin 94 penetrates a L shaped groove 95 formed on the second lift lever 48 by bending in the turning radial direction and the turning circumferential direction and is connected to the locking actuator 30 through a link, and is connected to the locking knob 23b through the link mechanism 39. Thereby, in the condition that the locking pin 94 locates in a turning radius portion of the L shaped groove 95 by the locking actuator 30 or the locking knob 23b, when the inside door opening lever 45b or the outside door opening lever 45a is rotated counterclockwise in FIG. 5 by the opening movement of the inside handle 23 or the movement of the outside handle 27, the second lift lever 48 is rotated in the same direction by the inside door opening lever 45b through a child pin 96 or by the push movement of the projection 71 of the second lift lever 48 by the outside door opening lever 45a, the first lift lever 47 is rotated counterclockwise by the engagement between the locking pin 94 located at the turning radius portion of the L shaped groove 95 and the long hole 93. When the locking pin 94 is located at a turning circumferential portion of the L shaped groove 95, even though the second lift lever 48 is rotated counterclockwise by the inside door opening lever 45b or the outside door opening lever 45a, the locking pin 94 moves relatively in the turning circumferential portion oft the L shaped groove 95 is not rotated, and does not transmit the rotational movement to the first lift lever 47. The second lift lever 48 and the inside door opening lever 45b are connected by the child pin 96 moved by a child protect lever so as to be able to engage and disengage. The window regulator 32 is mounted on the module base 21. As shown in FIG. 12 and FIG. 13, T shaped reinforcing plate 135 is fixed on a side face of outside of the compartment of the module base 21. The reinforcing plate 35 has minimum size in order to lighten the weight. Both ends of a top panel portion 141 of the reinforcing plate 135 are fixed to the module base 21 by screws 136. An inner edge of a bearing hole which is formed in a center portion of the top panel portion 141 is bent toward the inside of the compartment and a bearing portion 148 is formed, and a drive shaft 137 is rotatably supported. On an end portion of the drive shaft 137 which projects toward the outside of the compartment, a rotation center portion of a sector gear 138 and one end of the drive link 150 are fixed thereon so as to regulate the relative rotation. Both ends of the bearing portion 148 is nipped between a flange portion formed on the drive shaft 137 and the sector gear 138 and the movement in the axial direction of the drive shaft 137 is regulated. A strip-shaped portion 142 extended from the top panel portion 141 of the reinforcing plate 135 bends outside along the way and passes through a sectorial penetrating hole 140 formed on a center portion of the sector gear 38, and is positioned at the outside with respect to the sector gear 138. The strip-shaped portion 142 extends in parallel with the sector gear 138 and supports rotatably a shaft portion of a pinion 143 meshed with the sector gear 38 as an output member. The end portion of the strip-shaped portion 142 bends inside and overlaps with the module base 121. The screw 136 penetrates this overlapped portion and is screwed to a fixing seat 144 of a moving up and down actuator 147 which contacts with a side face of the inside of the compartment of the module base 121, and the end portion of the strip-shaped portion 142 is fixed to the module base 121. In a portion of the module base 121 which is opposite to the pinion 143, an opening 145 is formed and a mounting plate 146 is fixed so as to close the opening 145. The moving up and down actuator 147 including a motor and a speed reduction mechanism is mounted on the mounting plate 146 and an output shaft is connected to the pinion 143. As shown in FIG. 3, on a center portion of the drive link 150 rotated with the sector gear 138 in a body, a pin 151 is rotatably supported and one end of a guide link 152 is fixed to an inner end of the pin 151 projected toward the module base 121 of the drive link 150. The other end of the guide link 152 is guided movably in the horizontal direction by a guide 153 which is fixed to the side face of the outside of the compartment of the module base 121 and whose height is the same as the drive shaft 137. One end of a support link 154 is fixed to an outer end of the pin 151 projected to the opposite side of the drive link 150 so as to extend the guide link 152. A top end portion of the drive link 150 and a top end portion of the support link 154 are guided movably in the horizontal direction by a guide rail 155 mounted on a lower end side surface of the window glass 16 and support the window glass 16. The drive link 150, the pin 151, the-guide link 152 and the support link 154 constitute a pair of links which are rotatably connected at the center portion in X configuration and are mounted to the module base 121 at the outside of compartment, and constitute a link mechanism for supporting the window glass 16 and for moving up and down the window glass 16. Next, the assembling work and the operation of the sliding type door 10 for a motor vehicle according to the present invention is described. The remote control mechanism 28, the inside handle 23, the window regulator 32, the locking actuator 30, the release actuator 31 and so on are mounted on the module base 21, the mounted functional components are connected therebetween by the links and the module structure 22 are formed. In the assembling work of a motor vehicle, the handle of the outside handle 27 is mounted at the outside of the outer panel 11 and the base 27a of the outside handle 27 on which the swing link 62 is supported is mounted at the inside of the outer panel 11. The cable 64 is connected to the swing link 62, the cable 64 is introduced to inside of the compartment through the hole 68 or the hole 69 and is connected to the remote control mechanism 28. The link 80 which is connected to the front side latch mechanism 24 is introduced to the inside of the compartment through the hole 26 of the block 84, and the cable 85 and the wire harness which are connected to the rear side latch mechanism 25 are introduced to the inside of the compartment through the hole 89. In this condition, the module base 21 is mounted to the inner panel 12 so as to close the module mounting opening 20. The power sliding door driving unit 33, the electric supply device 34, the computer 35 and so on are mounted to the inner panel 12, and the connection of the cable, the electric wiring and so on are carried out and the trim 18 is mounted. As shown in FIG. 13, the electric supply device 34 may be mounted on the lower side of the module base 21. When the sliding door 10 is not locked, the opening movement of the inside handle 23 and the movement of the outside handle 27 or the release actuator 31 are transmitted to the front side the latch mechanism 24 and the rear side latch mechanism 25 and the latch mechanisms are in the door opening allowed position, the sliding door 10 is able to move toward the open direction. When the door is closed, the door closing lever 46 is rotated by the closing movement of the inside handle 23 through the link 43 or by the movement of the outside handle 27, this movement is transmitted through the cable 90 to the latch mechanism for engaging the opened door 10 to the body and the latch mechanism is in the door closing allowed condition, the sliding door 10 is able to move toward the close direction. Further, when the opening switch of the window glass 16 is operated, the motor of the moving up and down actuator 147 of the window regulator 32 is rotated toward the moving down direction of the window glass 16, the sector gear 138 is rotated by the pinion 143, the drive shaft 137 is rotated clockwise in FIG. 3, the drive link 150 is rotated in the same direction, the guide link 152 is guided by the guide 153 and is rotated counterclockwise while moving rightward in the horizontal direction, the support link 154 is rotated in the same direction, the guide rail 155 is moved downward and the window glass 16 is moved down. As shown in FIG. 15(a), a seal 97 covering the end portion of the cable 64 which transmits the up-and-down movement based on the outside handle 27 to the remote control mechanism 28 may be cuplike having no bellows. A wire 65 may be fitted into a bottom portion of the seal and may be caulked. A lower end opening of the seal may be opposite from the upper side to an opening of the coating tube 66 and the cable stopper 74 for fixing the coating tube 66. Further, as shown in FIG. 15(b), the coating tube 66 may be projected long from the portion which is fixed to the cable stopper 74 and the projected portion 98 may be covered by the seal 97. A seal 100 shown in FIG. 15(c) has a bellows which is formed at the upper side and a cylindrical notch 99 which the cable stopper 74 can go into is formed in the lower side at the end surface position being opposite to the cable stopper 74. In the above mentioned embodiment, a case in which the present invention is applied to a sliding type door for a motor vehicle is described. However, it is able to apply the present invention to a door for a motor vehicle supported by a hinge pin and it is able to constitute a part of the inner panel as a module. Further, in the embodiment, the front side latch mechanism 24 is mounted to the module base 21. However, as substitute for the module base 21, the front side latch mechanism 24 may be mounted to the inner panel 12. Further, the front latch mechanism 24 may be eliminated and a sliding door 10 for a motor vehicle in which only the rear side latch mechanism 25 is provided may be constituted. According to the embodiment, since the plural functional components are mounted to the module base almost without the bracket and are constituted as a module and it is able to adjust the operation as the module structure, it is able to decrease the number of parts and the weight. Further, it is able reduce the assembling time and cost by decrease the number of man-hour in assembling process of a vehicle and the number of parts. Further, instead of mounting the inside handle and the remote control mechanism to which the movement of the inside handle is transmitted to the inner panel through the bracket, it is able to mount the inside handle and the remote control mechanism to the module base and the adjustment of the operation becomes easily. Further, it is able to decrease the number of parts and the weight and it is able reduce the assembling time and cost. Further, according to the embodiment, instead of mounting the remote control mechanism and the locking actuator which is connected to the engagement mechanism of the remote control mechanism to the inner panel through the bracket, it is able to mount the remote control mechanism and the locking actuator to the module base and the adjustment of the operation becomes easily. Further, it is able to decrease the number of parts and the weight and it is able reduce the assembling time and cost. Further, it is able to dispose the moving up and down actuator including the electric motor at the inside of the compartment and the assembling work becomes easily, and the waterproofing becomes best and it is able to decrease the malfunction. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a door for a motor vehicle. 2. Description of the Related Art As a conventional door for a motor vehicle, particularly a conventional sliding door for a motor vehicle, a door stated in “Estima T/L Service manual” issued on January 2000 by TOYOTA MOTOR CORPORATION is known. As shown in FIG. 16 and FIG. 17 , in this door, an outer panel having a window portion formed at its upper side region and an inner panel having a window portion formed at its upper side portion are opposed and are connected at their peripheral portions and a space is formed between the lower side region of the outer panel and the lower side region of the inner panel and a window glass which opens and closes the window portions is disposed in the space so as to be able to move up and down. An inside handle 1 operated for opening and closing the door, a remote control mechanism 5 for transmitting the movement of the inside handle 1 and an outside handle 4 to pole members of latch mechanism 2 , 3 for maintaining the door in a closing state by engaging the door with a body, a locking actuator for operating an engagement and disengagement mechanism provided on the remote control mechanism 5 for being intermittent a path transmitting the movement of the inside handle 1 and the outside handle 4 to the pole members and so on are mounted at the inside of the inner panel, and a window regulator 7 for moving up and down the window glass and the latch mechanisms 2 , 3 are mounted at the outside of inner panel. In the prior sliding door for a vehicle, as mentioned above, since a great number of functional components are mounted on the inner panel through brackets, the number of man-hour in assembling process of a vehicle and the number of part increase and the weight of the door and the cost increase. Further, since a moving up and down actuator 8 of the window regulator 7 is mounted at the outside of the inner panel, the waterproofing becomes insufficient and there was a case that the insufficient waterproofing causes a malfunction of the moving up and down actuator 8 which is an electrical part. | <SOH> SUMMARY OF THE INVENTION <EOH>It is an object of the present invention to provide a vehicular door which can prevent the prior drawbacks. According to the present invention, a vehicular door includes an outer panel and an inner panel in which window portions are formed at their upper side region and which are connected at their peripheral portions, a space which is formed between the lower side region of the outer panel and the lower side region of the inner panel and in which a window glass for opening and closing the window portions is disposed so as to be able to move up and down, a module mounting opening formed on the lower side region of the inner panel and a module structure constituted by mounting a plural functional components including at least a remote control mechanism for transmitting a movement of an inside handle operated for opening and closing the door to a latch mechanism for maintaining the door in closing state by engaging the door with a body to the inside of compartment of a module base, wherein the module base is fluid-tightly fixed to the module mounting opening at its peripheral portion and the module structure is mounted on the inner panel. | 20040213 | 20051129 | 20050303 | 85008.0 | 0 | GUTMAN, HILARY L | VEHICULAR DOOR | UNDISCOUNTED | 1 | CONT-ACCEPTED | 2,004 |
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10,777,211 | ACCEPTED | Method for enhancing the bioavailability of ospemifene | This invention relates to a method for enhancing the bioavailability of a therapeutically active compound of the formula (I) or a geometric isomer, a stereoisomer, a pharmaceutically acceptable salt, an ester thereof or a metabolite thereof, wherein said compound is administered orally to the individual in connection with the intake of food. | 1. A method for enhancing the bioavailability of a therapeutically active compound of the formula (I) or a geometric isomer, a stereoisomer, a pharmaceutically acceptable salt, an ester thereof or a metabolite thereof, wherein said compound is administered orally to the individual in connection with the intake of food. 2. The method according to claim 1 wherein compound (I) is ospemifene. 3. The method according to claim 1, wherein the compound is administered at a time point which is in the range defined by 1 hour before starting the food intake and 2 hours after starting the food intake. 4. The method according to claim 3 wherein the compound is administered at a time point which is in the range defined to begin at a time point during the food intake and to end 1 hour after the food intake was started. 5. The method according to claim 4 wherein the compound is administered at a time point which is no later than 0.5 hour after starting the food intake. 6. The method according to claim 1 wherein the food is any foodstuff of nutritional value being capable of causing secretion of bile acids. 7. The method according to claim 1 wherein the compound is used for treatment or prevention of osteoporosis. 8. The method according to claim 1 wherein the compound is used for treatment or prevention of symptoms related to skin atrophy, or to epithelial or mucosal atrophy. 9. The method according to claim 8 wherein the symptoms are urinary symptoms or vaginal symptoms. | FIELD OF THE INVENTION This invention relates to a method for enhancing the bioavailability of ospemifene and closely related compounds by oral administering of said compounds in connection with food intake. BACKGROUND OF THE INVENTION The publications and other materials used herein to illuminate the background of the invention, and in particular, cases to provide additional details respecting the practice, are incorporated by reference. “SERM”s (selective estrogen receptor modulators) have both estrogen-like and antiestrogenic properties (Kauffman & Bryant, 1995). The effects may be tissue-specific as in the case of tamoxifen and toremifene which have estrogen-like effects in the bone, partial estrogen-like effect in the uterus and liver, and pure antiestrogenic effect in breast cancer. Raloxifene and droloxifen are similar to tamoxifen and toremifene, except that their antiestrogenic properties dominate. Based on the published information, many SERMs are more likely to cause menopausal symptoms than to prevent them. They have, however, other important benefits in elderly women: they decrease total and LDL cholesterol, thus deminishing the risk of cardiovascular diseases, and they may prevent osteoporosis and inhibit breast cancer growth in postmenopausal women. There are also almost pure antiestrogens under development. Ospemifene is the Z-isomer of the compound of formula (I) is one of the main metabolites of toremifene, and is known to be an estrogen agonist and antagonist (Kangas, 1990; International patent publications WO 96/07402 and WO 97/32574). The compound is also called (deaminohydroxy)toremifene and is also known under the code FC-1271a. Ospemifene has relatively weak estrogenic and antiestrogenic effects in the classical hormonal tests (Kangas, 1990). It has anti-osteoporosis actions and it decreases total and LDL cholesterol levels in both experimental models and in human volunteers (International patent publications WO 96/07402 and WO 97/32574). It also has antitumor activity in an early stage of breast cancer development in an animal breast cancer model. Ospemifene is also the first SERM which has been shown to have beneficial effects in climacteric syndromes in healthy women. The use of ospemifene for the treatment of certain climacteric disorders in postmenopausal women, namely vaginal dryness and sexual dysfunction, is disclosed in WO 02/07718. The published patent application WO 03/103649 describes the use of ospemifene for inhibition of atrophy and for the treatment or prevention of atrophy-related diseases or disorders in women, especially in women during or after the menopause. A particular form of atrophy to be inhibited is urogenital atrophy, which can be divided in two subgroups: urinary symptoms and vaginal symptoms. Ospemifene is a highly lipophilic compound. Although ospemifene has an excellent tolerability, a problem is the low aqueous solubility and rather low bioavailability. Therefore, when administered orally, the recommended daily dose is about 60 mg or more. There is a great need for providing administering methods resulting in improved bioavailability of ospemifene, and therefore the effect of food intake on ospemifene was studied. OBJECT AND SUMMARY OF THE INVENTION An object of the present invention is to provide an improved oral method of administering ospemifene, where the bioavailability of the drug is essentially increased. Thus, the invention concerns a method for enhancing the bioavailability of a compound of the (I) or a geometric isomer, a stereoisomer, a pharmaceutically acceptable salt, an ester thereof or a metabolite thereof, wherein said compound is administered to the individual in connection with the intake of food. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the mean serum concentration in male individuals (n=24) of ospemifene versus time following the administration of 60 mg ospemifene tablet in fasted condition (open circles) and after a high caloric, high-fat meal (filled circles). FIG. 2 shows the mean serum concentration in male individuals (n=12) of ospemifene versus time following the administration of 60 mg ospemifene tablet in fasted condition (open circles); after a high caloric, high-fat meal (filled circles) and after a low caloric, low-fat meal (stars). FIG. 3 shows the mean serum concentration in male individuals (n=12) of the ospemifene metabolite 4-hydroxy-ospemifene versus time following the administration of 60 mg ospemifene tablet in fasted condition (open triangles); after a high caloric, high-fat meal (filled triangles) and after a low caloric, low-fat meal (crosses). DETAILED DESCRIPTION OF THE INVENTION Although it is previously known that certain lipophilic drugs may benefit from administering the drug in connection with food intake, the strength of the effect of food intake upon the ospemifene bioavailability obtained in the present investigations was very surprising. Particularly compared to the behaviour of other SERMs, the food effect on ospemifene is remarkable. It was found (Anttila M., 1997) that the intake of food did not have any positive effect on the bioavailability of toremifene, which like ospemifene also has a low aqueous solubility. It was observed that food intake in fact retarded the absorption of toremifene. It has also been reported that the administration of raloxifene, another SERM, together with a standardized high-fat meal increases the absorption of raloxifene slightly, but that it does not lead to clinically meaningful changes in systemic exposure. While food intake causes only a 20% increase of raloxifene absorption, the effect on ospemifene absorption is a 2-3 fold increase. The term “food” shall be understood to cover any edible foodstuff having a nutritional value as an energy supplier. Thus the food can be solid, semisolid or liquid substance comprising one or more of the basic ingredients carbohydrates, fats and proteins. Surprisingly, a high percentage of fats or a high energy value in the food intake is not crucial for obtaining a high bioavailability for ospemifene. Neither is the amount of food intake crucial for the beneficial effect. It is believed that the secretion of bile acids may play an important role in the improved bioavailability, and therefore any foodstuff being capable of causing secretion of bile acids is expected to work. The drug is considered to be administered in connection with the intake of food if the drug is administered at a time point shortly before the start of the food intake, during the food intake or in a relatively short time after the food intake is completed. A preferable time range is defined to begin 1 hour before starting the food intake and to end 2 hours after starting the food intake. More preferably, the drug is administered at a time point which is in the range defined to begin at a time point during the food intake and to end 1 hour after the food intake was started. Most preferably, the drug is administered during the food intake or at a time point which is no later than 0.5 hour after starting the food intake. The method of enhancing the bioavailability of ospemifene and related compounds according to this invention is particularly useful when treating women during or after the menopause. However, the method according to this invention is not restricted to women in this age group. The term “metabolite” shall be understood to cover any ospemifene or (deaminohydroxy)toremifene metabolite already discovered or to be discovered. As examples of such metabolites can be mentioned the oxidation metabolites mentioned in Kangas (1990) on page 9 (TORE VI, TORE VII, TORE XVIII, TORE VIII, TORE XIII, especially TORE VI and TORE XVIII, and other metabolites of the compound. The most important metabolite of ospemifene 4-hydroxyospemifene, which has the formula The use of mixtures of isomers of compound (I) shall also be included in this invention. The method of enhancing bioavailability is useful in any application of ospemifene, especially when the compound is used for treatment or prevention of osteoporosis or for treatment or prevention of symptoms related to skin atrophy, or to epithelial or mucosal atrophy. A particular form of atrophy which can be inhibited by administering of ospemifene is urogenital atrophy. Symptoms related to urogenital atrophy can be divided in two subgroups: urinary symptoms and vaginal symptoms. As examples of urinary symptoms can be mentioned micturation disorders, dysuria, hematuria, urinary frequency, sensation of urgency, urinary tract infections, urinary tract inflammation, nocturia, urinary incontinence, urge incontinence and involuntary urinary leakage. As examples of vaginal symptoms can be mentioned irritation, itching, burning, maladorous discharge, infection, leukorrhea, vulvar pruritus, feeling of pressure and postcoital bleeding. According to previous data, the optimal clinical dose of ospemifene is expected to be higher than 25 mg daily and lower than 100 mg daily. A particularly preferable daily dose has been suggested in the range 30 to 90 mg. At the higher doses (100 and 200 mg daily), ospemifene shows properties more similar to those of tamoxifen and toremifene. Due to the enhanced bioavailability according to the method of this invention, it can be predicted that the same therapeutical effect can be achieved with doses lower those recommended earlier. The invention will be disclosed more in detail in the following non-restrictive Experimental Section. Experimental Section Two clinical studies were carried out in order to assess the bioavailability of ospemifene in healthy male subjects after intake of high caloric content (860 kcal) and high-fat breakfast compared to bioavailability of ospemifene administered in fasted condition (study A). In a separate study (study B), the bioavailability of ospemifene after intake of low caloric content (300 kcal), low-fat breakfast was assessed and the results were compared to those obtained in study A (i.e. ospemifene bioavailability after intake of high caloric, high-fat breakfast or after ospemifene administering in fasted condition). Study A In study A, 24 healthy male volunteers (mean age 23.8 years, mean BMI 22.8 kg/m2) received single oral doses of 60 mg ospemifene, once under fed condition after consuming a standardised high-fat, high caloric breakfast, and once after an overnight fast. Blood samples for pharmacokinetic assessments were drawn during 72 hours at each study period. A washout period between the two treatments was at least 2 weeks. The breakfast consisted of the following ingredients: two eggs fried in butter (50 g), two strips of bacon (34 g), two slices of toast with butter (50 g), 60 g hash brown potatoes and 240 ml of whole milk (pecentage of fat=3.5%). The meal provided approximately 150, 170 and 540 kcal from protein, carbohydrate and fat, respectively. Ospemifene administration in connection with high caloric, high-fat test meal: Following an overnight fast of at least 10 hours at the study site, the subjects were given the test meal described above 30 minutes before ospemifene dosing (60 mg tablet). The meal had to be consumed over the 30 minutes, immediately followed by administration of ospemifene. Ospemifene administration in fasted condition: Following an overnight fast of at least 10 hours at the study site, the subjects were given one ospemifene tablet (60 mg) with 240 ml of water. No food was allowed for at least 4 hours after the ospemifene dose. Results from Study A A substantial effect of food intake was observed on the bioavailability of ospemifene and its main metabolite 4-hydroxy-ospemifene. FIG. 1 shows the mean serum concentration of ospemifene versus time following the administration of 60 mg ospemifene tablet in fasted condition (open circles) and after a high caloric, high-fat meal (filled circles). The results of this study showed clearly that the ospemifene bioavailability was enhanced by concomitant ingestion of ospemifene and a meal. Due to the surprising and promising results of this study it was decided to carry out a second study (study B below) to find out the effect of a low caloric, low-fat meal on the bioavailability of ospemifene. Study B In study B, 12 healthy male volunteers (mean age 23.8 years, mean BMI 22.3 kg/m2) of the 24 subjects in study A were subjected to ospemifene administering in combination with the intake of a low caloric, low-fat meal. The results were compared to those obtained in study A for the same individuals. Ospemifene administering in connection with low caloric, low-fat meal: The composition of the light breakfast (approximately 300 kcal) was as follows: two slices of toast with margarine (5 g, fat content 60%), 6 slices (30 g) of cucumber, 240 ml skimmed (non-fat) milk and 100 ml orange juice. The test meal provided approximately 50, 180 and 70 kcal from protein, carbohydrate and fat, respectively. Following an overnight fast of at least 10 hours at the study site, the subjects were given the test meal described above 30 minutes before ospemifene dosing (60 mg tablet). The meal had to be consumed over the 30 minutes, immediately followed by administration of ospemifene. Results from Study B FIG. 2 shows the mean serum concentration of ospemifene versus time following the administration of 60 mg ospemifene tablet in fasted condition (open circles; data obtained from study A); after a high caloric, high-fat meal (filled circles; data obtained from study A) and after a low caloric, low-fat meal (stars). FIG. 3 shows the mean serum concentration of the ospemifene metabolite 4-hydroxy-ospemifene versus time following the administration of 60 mg ospemifene tablet in fasted condition (open triangles; data obtained from study A); after a high caloric, high-fat meal (filled triangles; data obtained from study A) and after a low caloric, low-fat meal (crosses). The results of this study showed clearly that the bioavailability of ospemifene was also enhanced by concomitant ingestion of ospemifene and a low caloric, low-fat meal. Although the fat content of the low-fat meal was much lower than that of the high-fat meal, the bioavailabity of ospemifene was only slightly lower for the low-fat meal. Therefore it can be concluded that the effect of food on the ospemifene bioavailability is not dependent on the fat content of the meal ingested. Instead, stimulation of bile flow due to meal ingestion may enhance the solubilisation of ospemifene. It will be appreciated that the methods of the present invention can be incorporated in the form of a variety of embodiments, only a few of which are disclosed herein. It will be apparent for the expert skilled in the field that other embodiments exist and do not depart from the spirit of the invention. Thus, the described embodiments are illustrative and should not be construed as restrictive. BIBLIOGRAPHY Anttila M. Effect of food on the pharmacokinetics of toremifene. Eur J Cancer, 1997; 33, suppl 8: 1144, 1997. Kangas L. Biochemical and pharmacological effects of toremifene metabolites. Cancer Chemother Pharmacol 27:8-12, 1990. Kauffman RF, Bryant HU. Selective estrogen receptor modulators. Drug News Perspect 8: 531-539, 1995. | <SOH> BACKGROUND OF THE INVENTION <EOH>The publications and other materials used herein to illuminate the background of the invention, and in particular, cases to provide additional details respecting the practice, are incorporated by reference. “SERM”s (selective estrogen receptor modulators) have both estrogen-like and antiestrogenic properties (Kauffman & Bryant, 1995). The effects may be tissue-specific as in the case of tamoxifen and toremifene which have estrogen-like effects in the bone, partial estrogen-like effect in the uterus and liver, and pure antiestrogenic effect in breast cancer. Raloxifene and droloxifen are similar to tamoxifen and toremifene, except that their antiestrogenic properties dominate. Based on the published information, many SERMs are more likely to cause menopausal symptoms than to prevent them. They have, however, other important benefits in elderly women: they decrease total and LDL cholesterol, thus deminishing the risk of cardiovascular diseases, and they may prevent osteoporosis and inhibit breast cancer growth in postmenopausal women. There are also almost pure antiestrogens under development. Ospemifene is the Z-isomer of the compound of formula (I) is one of the main metabolites of toremifene, and is known to be an estrogen agonist and antagonist (Kangas, 1990; International patent publications WO 96/07402 and WO 97/32574). The compound is also called (deaminohydroxy)toremifene and is also known under the code FC-1271a. Ospemifene has relatively weak estrogenic and antiestrogenic effects in the classical hormonal tests (Kangas, 1990). It has anti-osteoporosis actions and it decreases total and LDL cholesterol levels in both experimental models and in human volunteers (International patent publications WO 96/07402 and WO 97/32574). It also has antitumor activity in an early stage of breast cancer development in an animal breast cancer model. Ospemifene is also the first SERM which has been shown to have beneficial effects in climacteric syndromes in healthy women. The use of ospemifene for the treatment of certain climacteric disorders in postmenopausal women, namely vaginal dryness and sexual dysfunction, is disclosed in WO 02/07718. The published patent application WO 03/103649 describes the use of ospemifene for inhibition of atrophy and for the treatment or prevention of atrophy-related diseases or disorders in women, especially in women during or after the menopause. A particular form of atrophy to be inhibited is urogenital atrophy, which can be divided in two subgroups: urinary symptoms and vaginal symptoms. Ospemifene is a highly lipophilic compound. Although ospemifene has an excellent tolerability, a problem is the low aqueous solubility and rather low bioavailability. Therefore, when administered orally, the recommended daily dose is about 60 mg or more. There is a great need for providing administering methods resulting in improved bioavailability of ospemifene, and therefore the effect of food intake on ospemifene was studied. | <SOH> OBJECT AND SUMMARY OF THE INVENTION <EOH>An object of the present invention is to provide an improved oral method of administering ospemifene, where the bioavailability of the drug is essentially increased. Thus, the invention concerns a method for enhancing the bioavailability of a compound of the (I) or a geometric isomer, a stereoisomer, a pharmaceutically acceptable salt, an ester thereof or a metabolite thereof, wherein said compound is administered to the individual in connection with the intake of food. | 20040213 | 20120807 | 20050818 | 83160.0 | 1 | GEMBEH, SHIRLEY V | METHOD FOR ENHANCING THE BIOAVAILABILITY OF OSPEMIFENE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,777,411 | ACCEPTED | Artificial spinal unit assemblies | An artificial functional spinal unit is provided comprising, generally, an expandable artificial intervertebral implant that can be placed via a posterior surgical approach and used in conjunction with one or more artificial facet joints to provide an anatomically correct range of motion. Expandable artificial intervertebral implants in both lordotic and non-lordotic designs are disclosed, as well as lordotic and non-lordotic expandable cages for both PLIF (posterior lumber interbody fusion) and TLIF (transforaminal lumbar interbody fusion) procedures. The expandable implants may have various shapes, such as round, square, rectangular, banana-shaped, kidney-shaped, or other similar shapes. By virtue of their posteriorly implanted approach, the disclosed artificial FSU's allow for posterior decompression of the neural elements, reconstruction of all or part of the natural functional spinal unit, restoration and maintenance of lordosis, maintenance of motion, and restoration and maintenance of disc space height. | 1. An expandable intervertebral implant comprising: a lower body having an inferior and superior surface, the superior surface having a wall defining a recessed channel, and the wall having a hole defined therethrough; an upper body having an inferior and superior surface, the inferior surface having at an angled projection extending downward into the recessed channel of the lower body; a joint insert disposed within the recessed channel of the lower body and having an inferior and superior surface, the superior surface having an angled projection extending upward and in communication with the angled projection of the upper body; and an expansion device capable of being inserted through the hole in the lower body such that upon insertion, the angled projection of the joint insert slidingly engages the angled projection of the upper body. 2. The expandable intervertebral implant of claim 1, wherein the lower body further comprises a plurality of holes defined through the wall defining the recessed channel, and a plurality of expansion devices are capable of being inserted through the plurality of holes. 3. The expandable intervertebral implant of claim 1, wherein the upper body further comprises a plurality of angled projections extending downward into the recessed channel, and the joint insert further comprises a plurality of angled projections extending upward and in communication with the plurality of angled projections of the upper body. 4. The expandable intervertebral implant of claim 1, wherein the upper body and the lower body are coupled. 5. The expandable intervertebral implant of claim 4, wherein the upper and lower bodies are couple via a captive peg. 6. The expandable intervertebral implant of claim 5, wherein the captive peg also secures the joint insert and allows rotation of the joint insert relative to the captive peg. 7. The expandable intervertebral implant of claim 1, wherein the superior surface of the upper body and the inferior surface of the lower body further comprises an osteoconductive scaffolding into which bone may grow. 8. The expandable intervertebral implant of claim 1, wherein the upper body and the lower body have substantially similar shapes. 9. The expandable intervertebral implant of claim 8, wherein the superior surface of the upper body and the superior surface of the lower body are substantially flat. 10. The expandable intervertebral implant of claim 1, wherein the lower body further comprises a a securing member coupled to the wall around the perimeter of the lower body and capable of rotating into a substantially perpendicular position, the securing member having a hole defined therethrough and capable of being fixedly attached to an adjacent vertebral body. 11. An artificial facet joint comprising: an upper and lower multi-axial pedicle screw, both having a lockable head having a hole defined therethrough, the lockable head comprising a rod holding device that can be inserted into the lockable head, the rod holding device having a hole defined therethrough and substantially aligned with the hole defined through the lockable head, and a set screw that is engaged into the lockable head such that the rod holding device transfers force from the set screw to the lockable head; and a rod having a central rod portion and two washer-type heads on each end of the central rod portion, the central rod portion slidingly positioned through the hole in the rod holding device such that the rod is allowed to translate and rotate within the rod holding device after the set screw has been engaged. 12. An artificial facet joint comprising: an upper and lower pedicle screw having a threaded bottom end and a post-type head; and a plate having an upper end with a hole defined through and a lower end with a hole defined therethrough, each hole having an elongated shape, the plate being disposed above the upper and lower pedicle screws such that the post-type heads traverse each hole in the plate. 13. The artificial facet joint of claim 11, further comprising a cushioning material located within each hole and around the post-type heads. 14. The artificial facet joint of claim 11, wherein the post-type heads further comprise a locking device to prevent dislocation of the plate from the post-type heads. | This application is a continuation-in-part of U.S. patent application Ser. No. 10/634,950, filed Aug. 5, 2003. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not applicable FIELD OF THE INVENTION The present invention generally relates to functional spinal implant assemblies for insertion into the intervertebral space between adjacent vertebral bones and reconstruction of the posterior elements to provide stability, flexibility and proper biomechanical motion. More specifically, the present invention relates to artificial functional spinal units comprising an expandable artificial intervertebral implant that can be inserted via a posterior surgical approach and used in conjunction with one or more artificial facet joints to provide a more anatomically correct range of motion. While a posterior surgical approach is preferred, the invention described herein may also be used in conjunction with an anterior surgical approach. BACKGROUND OF THE INVENTION The human spine is a complex mechanical structure composed of alternating bony vertebrae and fibrocartilaginous discs that are connected by strong ligaments and supported by musculature that extends from the skull to the pelvis and provides axial support to the body. The intervertebral discs primarily serve as a mechanical cushion between adjacent vertebral segments of the spinal column and generally comprise three basic components: the nucleus pulposus, the anulus fibrosis, and two vertebral end plates. The end plates are made of thin cartilage overlying a thin layer of hard cortical bone that attaches to the spongy, cancellous bone of the vertebral body. The anulus fibrosis forms the disc's perimeter and is a tough outer ring that binds adjacent vertebrae together. The vertebrae generally comprise a vertebral foramen bounded by the anterior vertebral body and the neural arch, which consists of two pedicles and two laminae that are united posteriorly. The spinous and transverse processes protrude from the neural arch. The superior and inferior articular facets lie at the root of the transverse process. The term “functional spinal unit” (“FSU”) refers to the entire motion segment: the anterior disc and the posterior facet joints, along with the supporting ligaments and connective tissues. The spine as a whole is a highly flexible structure capable of a high degree of curvature and twist in nearly every direction. However, genetic or developmental irregularities, trauma, chronic stress, and degenerative wear can result in spinal pathologies for which surgical intervention maybe necessary. It is common practice to remove a spinal disc in cases of spinal disc deterioration, disease or spinal injury. The discs sometimes become diseased or damaged such that the intervertebral separation is reduced. Such events cause the height of the disc nucleus to decrease, which in turn causes the anulus to buckle in areas where the laminated plies are loosely bonded. As the overlapping laminated plies of the anulus begin to buckle and separate, either circumferential or radial anular tears may occur. Such disruption to the natural intervertebral separation produces pain, which can be alleviated by removal of the disc and maintenance of the natural separation distance. In cases of chronic back pain resulting from a degenerated or herniated disc, removal of the disc becomes medically necessary. In some cases, the damaged disc may be replaced with a disc prosthesis intended to duplicate the function of the natural spinal disc. U.S. Pat. No. 4,863,477 discloses a resilient spinal disc prosthesis intended to replace the resiliency of a natural human spinal disc. U.S. Pat. No. 5,192,326teaches a prosthetic nucleus for replacing just the nucleus portion of a human spinal disc. In other cases it is desired to fuse the adjacent vertebrae together after removal of the disc, sometimes referred to as “intervertebral fusion” or “interbody fusion.” Many techniques and instruments have been devised to perform intervertebral fusion. There is common agreement that the strongest intervertebral fusion is the interbody (between the lumbar bodies) fusion, which may be augmented by a posterior or facet fusion. In cases of intervertebral fusion, either structural bone or an interbody fusion cage filled with morselized bone is placed centrally within the space where the spinal disc once resided. Multiple cages or bony grafts may be used within that space. Such practices are characterized by certain disadvantages, most important of which is the actual morbidity of the procedure itself. Placement of rigid cages or structural grafts in the interbody space either requires an anterior surgical approach, which carries certain unavoidable risks to the viscous structures overlying the spine (intestines, major blood vessels, and the ureter), or they may be accomplished from a posterior surgical approach, thereby requiring significant traction on the overlying nerve roots. The interval between the exiting and traversing nerve roots is limited to a few millimeters and does not allow for safe passage of large intervertebral devices, as may be accomplished from the anterior approach. Alternatively, the anterior approach does not allow for inspection of the nerve roots, is not suitable alone for cases in which the posterior elements are not competent, and most importantly, the anterior approach is associated with very high morbidity and risk where there has been previous anterior surgery. Another significant drawback to fusion surgery in general is that adjacent vertebral segments show accelerated deterioration after a successful fusion has been performed at any level. The spine is by definition stiffer after the fusion procedure, and the natural body mechanics place increased stress on levels proximal to the fused segment. Other drawbacks include the possibility of “flat back syndrome” in which there is a disruption in the natural curvature of the spine. The vertebrae in the lower lumbar region of the spine reside in an arch referred as having a sagittal alignment. The sagittal alignment is compromised when adjacent vertebral bodies that were once angled toward each other on their posterior side become fused in a different, less angled orientation relative to one another. Finally, there is always the risk that the fusion attempt may fail, leading to pseudoarthrosis, an often painful condition that may lead to device failure and further surgery. Conventional interbody fusion cages generally comprise a tubular metal body having an external surface threading. They are inserted transverse to the axis of the spine, into preformed cylindrical holes at the junction of adjacent vertebral bodies. Two cages are generally inserted side by side with the external threading tapping into the lower surface of the vertebral bone above, and the upper surface of the vertebral bone below. The cages include holes through which the adjacent bones are to grow. Additional materials, for example autogenous bone graft materials, maybe inserted into the hollow interior of the cage to incite or accelerate the growth of the bone into the cage. End caps are often utilized to hold the bone graft material within the cage. These cages of the prior art have enjoyed medical success in promoting fusion and grossly approximating proper disc height. As previously discussed, however, cages that would be placed from the safer posterior route would be limited in size by the interval between the nerve roots. It would therefore, be a considerable advance in the art to provide a fusion implant assembly which could be expanded from within the intervertebral space, thereby minimizing potential trauma to the nerve roots and yet still providing the ability to restore disc space height. Ultimately though, it is important to note that the fusion of the adjacent bones is an incomplete solution to the underlying pathology as it does not cure the ailment, but rather simply masks the pathology under a stabilizing bridge of bone. This bone fusion limits the overall flexibility of the spinal column and artificially constrains the normal motion of the patient. This constraint can cause collateral injury to the patient's spine as additional stresses of motion, normally borne by the now-fused joint, are transferred onto the nearby facet joints and intervertebral discs. Thus, it would be an even greater advance in the art to provide an implant assembly that does not promote fusion, but instead closely mimics the biomechanical action of the natural disc cartilage, thereby permitting continued normal motion and stress distribution. SUMMARY OF THE INVENTION Accordingly, an artificial functional spinal unit (FSU) is provided comprising, generally, an expandable artificial intervertebral implant that can be placed via a posterior surgical approach and used in conjunction with one or more artificial facet joints to provide an anatomically correct range of motion. Expandable artificial intervertebral implants in both lordotic and non-lordotic designs are disclosed, as well as lordotic and non-lordotic expandable cages for both PLIF (posterior lumber interbody fusion) and TLIF (transforaminal lumbar interbody fusion) procedures. The expandable implants may have various shapes, such as round, square, rectangular, trapezoidal, banana-shaped, kidney-shaped, or other similar shapes. By virtue of their posteriorly implanted approach, the disclosed artificial FSU's allow for posterior decompression of the neural elements, reconstruction of all or part of the natural functional spinal unit, restoration and maintenance of lordosis, maintenance of motion, and restoration and maintenance of disc space height. The posterior implantation of an interbody device provides critical benefits over other anterior implanted devices. Placement of posterior devices that maintain mobility in the spine have been limited due to the relatively small opening that can be afforded posteriorly between the exiting and transversing nerve roots. Additionally, placement of posterior interbody devices requires the removal of one or both facet joints, further destabilizing the spine. Thus conventional posteriorly placed interbody devices have been generally limited to interbody fusion devices. Since a properly functioning natural FSU relies on intact posterior elements (facet joints) and since it is necessary to remove these elements to place a posterior interbody device, a two-step procedure is disclosed that allows for placement of an expandable intervertebral implant and replacement of one or both facets that are necessarily removed during the surgical procedure. The expansile nature of the disclosed devices allow for restoration of disc height once inside the vertebral interspace. The expandable devices are collapsed prior to placement and then expanded once properly inserted in the intervertebral space. During the process of expansion, the endplates of the natural intervertebral disc, which essentially remain intact after removal or partial removal of the remaining natural disc elements, are compressed against the device, which thereby facilitates bony end growth onto the surface of the artificial implant. Once the interbody device is in place and expanded, the posterior element is reconstructed with the disclosed pedicle screw and rod system, which can also be used to distract the disk space while inserting the artificial implant. Once the interbody device is in place and expanded, the posterior element is further compressed, again promoting bony end growth into the artificial implant. This posterior compression allows for anterior flexion but replaces the limiting element of the facet and interspinous ligament and thereby limits flexion to some degree, and in doing so maintains stability for the anteriorly located interbody device. The posterior approach avoids the potential risks and morbidity of the anterior approach, which requires mobilization of the vascular structures, the ureter, and exposes the bowels to risk. Also, the anterior approach does not offer the surgeon an opportunity to view the posterior neural elements and thereby does not afford an opportunity for decompression of those elements. Once an anterior exposure had been utilized a revision procedure is quite risky and carries significant morbidity. While the posterior surgical approach is preferred, there may be circumstances that prevent posterior placement. If an anterior approach must be performed, the disclosed devices may be inserted anteriorly without affecting functionality. The artificial FSU generally comprises an expandable intervertebral implant and one or more artificial facet joints. The expandable intervertebral implant generally comprises a pair of spaced apart plate members, each with a vertebral body contact surface. The general shape of the plate members may be round, square, rectangular, trapezoidal, banana shaped, kidney shaped, or some other similar shape, depending on the desired vertebral implantation site. Because the artificial intervertebral implant is to be positioned between the facing surfaces of adjacent vertebral bodies, the plate members are arranged in a substantially parallel planar alignment (or slightly offset relative to one another in accordance with proper lordotic angulation) with the vertebral body contact surfaces facing away from one another. The plate members are to mate with the vertebral bodies so as to not rotate relative thereto, but rather to permit the spinal segments to axially compress and bend relative to one another in manners that mimic the natural motion of the spinal segment. This natural motion is permitted by the performance of an expandable joint insert, which is disposed between the plate members. The securing of the plate members to the vertebral bone is achieved through the use of a osteoconductive scaffolding machined into the exterior surface of each plate member. Alternatively, a mesh of osteoconductive surface may be secured to the exterior surface of the plate members by methods known in the art. The osteoconductive scaffolding provides a surface through which bone may ultimately grow. If an osteoconductive mesh is employed, it may be constructed of any biocompatible material, both metal and non-metal. Each plate member may also comprise a porous coating (which may be a sprayed deposition layer, or an adhesive applied beaded metal layer, or other suitable porous coatings known in the art, i.e. hydroxy appetite). The porous coating permits the long-term ingrowth of vertebral bone into the plate member, thus permanently securing the prosthesis within the intervertebral space. In more detail, the expandable artificial implant of the present invention generally comprises four parts: an upper body, a lower body, an expandable joint insert, that fits into the lower body, and an expansion device, which may be an expansion plate, screw, or other similar device. The upper body generally comprises a substantially concave inferior surface and a substantially planar superior surface. The substantially planar superior surface of the upper body may have some degree of convexity to promote the joining of the upper body to the intact endplates of the natural intervertebral disc upon compression. The lower body generally comprises a recessed channel, having a rectangular cross-section, which extends along the superior surface of the lower body in the medial-lateral direction and substantially conforms to the shape of the upper and lower bodies. The lower body further comprises a substantially planar inferior surface that may have some degree of convexity to promote the joining of the lower body to the intact endplates of the natural intervertebral disc upon compression. The expandable joint insert resides within the channel on the superior surface of the lower body. The expandable joint insert has a generally flat inferior surface and a substantially convex superior surface that articulates with the substantially concave inferior surface of the upper body. Prior to expansion of the artificial implant, the generally flat inferior surface of the expandable joint insert rests on the bottom surface of the channel. The expandable joint insert is raised above the bottom of the channel by means of an expansion screw, an expansion plate, or other similar device, that is inserted through an expansion hole or slot. The expansion hole or slot is disposed through the wall of the lower body formed by the channel. The expansion hole or slot gives access to the lower surface of the channel and is positioned such that the expansion device can be inserted into the expansion hole or slot via a posterior surgical approach. As the expansion device is inserted through the expansion slot, into the channel, and under the expandable joint insert, the expandable joint insert is raised above the floor of the channel and lifts the upper body above the lower body to the desired disc height. The distance from the inferior surface of the lower body and the superior surface of the upper body should be equal to the ideal distraction height of the disk space. As the artificial implant is flexed and extended, the convex superior surface of the expandable joint insert articulates with the concave inferior surface of the upper body. After the insertion and expansion of the expandable intervertebral implant, the posterior facet joints may be reconstructed by employing the disclosed artificial facet joints. One embodiment of the artificial facet joint generally comprises a lower and upper multi-axial pedicle screw joined by a rod bridging the vertebral bodies above and below the artificial implant. The rod comprises a washer-type head at its lower (caudad) end. The rod fits into the heads of the pedicle screws and a top loaded set screw is placed in the pedicle screw heads. The disclosed pedicle screw system may employ different types of pedicle screws so that the top loaded set screw may or may not lock down on the rod depending on surgeon preference. If a non-locking pedicle screw is used the caudad end remains fully multi-axial. The upper (cephalad) end of the rod is held within the head of the upper pedicle screw with a set screw which locks down on the rod and eliminates any rod movement at the cephalad end, which by nature has limited multi-axial function. In an alternative embodiment of an artificial facet joint, the rod may comprise washer-type heads on both ends (caudad and cephalad) so that both pedicle screws can be of the non-locking variety. In the event of a two level surgical procedure, three pedicle screws would be employed with a single rod, which would have washer-type heads at both ends. The middle pedicle screw would be a locking-type and the upper most and lower most pedicle screws would be of the non-locking variety. In addition, another embodiment of the artificial facet joint is disclosed that generally comprises two locked pedicle screws joined by a rod having a ball and socket joint centrally located on the rod between the two pedicle screws. The locking of the pedicle screws prevents the screw head from swiveling, but allows rotation and translation of the rod. While conventional locking type pedicle screws may be employed, a novel locking type pedicle screw is also disclosed. Locking type pedicle screws comprise a set screw located in the pedicle screw head, which applies force to the retaining rod as it is tightened. One the set screw is tightened, rotational and translational movement of the rod within the head of the pedicle screw is prohibited. In addition, the multi-axial movement of the pedicle screw head is also prohibited making the entire assembly a fixed structure. By employing the rod holding device described in detail below, the set screw can be tightened and the multi-axial movement of the pedicle screw head can be prohibited without limiting the translational and rotational movement of the retaining rod. The rod holding device generally comprises a solid insert fitting within the pedicle screw head with a hole in which the retaining rod is slidingly positioned. As the set screw is tightened, force is applied to the rod holding device and transferred to the bottom of the pedicle screw head without applying force to the retaining rod. This allows fixation of the pedicle screw head without limiting movement of the retaining rod. In another preferred embodiment, the artificial facet joint generally comprises an upper and lower pedicle screw having post-type heads. Rather than the previously described rod, a retaining plate is employed. Elongated holes are defined through the retaining plate, which are positioned upon the post-type heads of the pedicle screws. The post-type heads are allowed to move within the elongated holes, providing limited range of motion. Employing cushioning pads made of rubber or similar biocompatible material may dampen the movement of the plate. The post-type heads may also comprise threaded or lockable caps to prevent dislocation of the plate from the post-type heads. In instances where a fusion procedure is unavoidable, a PLIF and TLIF cages are disclosed that utilize the expansion principal of the functional artificial intervertebral implant. One embodiment of the PLIF and TLIF cages generally comprises three parts: An external body, an internal body, and an expansion device. The external and internal bodies will have substantially the same shape and will be shaped accordingly to the procedures for which they will be used, more specifically, a rectangular cage is preferred for a PLIF procedure and round or banana shaped cage is preferred for the TLIF procedure. Both the external and internal bodies comprise a mesh structure in which an osteoconductive substance can be placed (i.e. morsilized autograph or an osteobiologic substitute). The external body of the cage contains an internal void space that houses the internal body. The external body further comprises an expansion window on its superior surface through which the internal body is raised upon expansion of the cage. The internal body comprises a planar plate member that is slightly larger than the expansion window in the superior surface of the external body such that when the cage is expanded the planar plate member secures itself against the interior side of the expansion window, thereby interlocking the external and internal bodies and eliminating mobility between the two bodies. Similar to the functional expandable implant, an expansion device is placed through an expansion slot. The expansion device lifts the internal body relative to the external body, interlocking the planar plate member of the internal body against the interior of the expansion window, and pushing the mesh structure of the internal body through the expansion window and above the superior surface of the external body. Varying the height of the expansion device and the dimensions of the external and internal bodies allows for various distraction heights to regain disc space. As with the functional intervertebral implant, the PLIF and TLIF cages may take the form of either an expandable lordotic cage or a non-lordotic cage. In another embodiment of the PLIF and TLIF cage, a joint insert is employed that is similar to that used in the functional implant. This embodiment generally comprises four parts: an upper body, a lower body, an expandable joint insert that fits into the lower body, and an expansion screw or other similar device. The upper body generally comprises a substantially planar superior surface and one or more angled projections extending downward from the upper body's inferior surface. The substantially planar superior surface of the upper body may have some degree of convexity to promote the joining of the upper body to the intact endplates of the natural intervertebral disc upon compression. The lower body generally comprises a recessed channel, preferably having a rectangular cross-section, which extends along the superior surface of the lower body in the medial-lateral direction. The lower body further comprises a substantially planar inferior surface that may have some degree of convexity to promote the joining of the lower body to the intact endplates of the natural intervertebral disc upon compression. The expandablejoint insert resides within the channel on the superior surface of the lower body. The expandable joint insert has a generally flat inferior surface and one or more angled projections extending upward from the superior surface of the joint insert that are in communication with the angled projections extending downward from the inferior surface of the upper body. Expansion is accomplished by utilizing as expansion screw or other similar device through an expansion hole disposed through the lower body. Insertion of the expansion screw forces the one or more angled projections of the expansion joint insert to articulate against the one or more angled projections of the upper body causing the upper body to lift above the lower body. The maximum expansion height may be limited by employing one or more retaining pegs. The retaining pegs also prohibit dislocation and rotation of the upper body relative to the lower body. The shapes and sizes of all of the devices disclosed herein are dependent upon the surgical approach employed to insert the device and the position in the spine in which it is placed. Generally, they will range from about 6 to about 11 millimeters in height for cervical devices and about 10 to about 18 millimeters in height for lumbar devices. However some deviation from these ranges may occur from patient to patient. Round devices will preferably range from about 14 to about 26 millimeters in diameter. Square devices will preferably range from about 14×14 to about 26×26 millimeters. Rectangular and trapezoidal devices will preferably range from about 12 millimeters along its shortest side and to about 30 millimeters along its longest side. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of a round, expandable intervertebral implant of the present invention. FIG. 2 is a side cross-sectional view of the round, expandable intervertebral implant shown in FIG. 1. FIG. 3a is a top view of a banana-shaped, expandable intervertebral implant of the present invention. FIG. 3b is a side cross-sectional view of the banana-shaped, expandable intervertebral implant shown in FIG. 3a. FIG. 4a is a cross-sectional illustration of an expandable intervertebral implant in compression. FIG. 4b is a cross-sectional illustration of an expandable intervertebral implant in flexion. FIG. 5a is a top view of a banana-shaped, expandable intervertebral implant, illustrating the insertion of expansion screws to expand the joint. FIG. 5b is a top view of a banana-shaped, expandable intervertebral implant, illustrating the insertion of a non-threaded expansion device to expand the joint. FIG. 5c is a top view of a banana-shaped, expandable intervertebral implant with a posteriorly positioned expansion window. FIG. 6a is a top view of a banana-shaped, expandable intervertebral implant, illustrating the insertion of an expansion plate to expand the joint. FIG. 6b is a side cross-sectional view of a banana-shaped, expandable intervertebral implant, illustrating the insertion of an expansion plate to expand the joint. FIG. 6c is a side cross-sectional view of an expandable intervertebral implant, featuring retaining pegs. FIG. 6d is a side cross-sectional view of an expandable intervertebral implant in flexion, featuring retaining pegs. FIG. 7a is a cross-sectional view of an expandable intervertebral implant, prior to expansion. FIG. 7b is a cross-sectional view of an expandable intervertebral implant, following expansion. FIG. 7c is a cross-sectional view of an expandable intervertebral implant employing butress screws to secure the device. FIG. 7d is a cross-sectional view of an expandable intervertebral implant employing an expansion plate with a securing keel to secure the device. FIG. 7e is a side perspective of an expandable intervertebral implant employing a securing keel. FIG. 8 is a side perspective view illustrating placement of an expandable intervertebral implant within an intervertebral space. FIG. 9a is a side view of an artificial facet joint of the present invention, featuring a rod with two washer-type heads. FIG. 9b is a side view of an artificial facet joint of the present invention, featuring a rod with a single washer-type head. FIG. 9c is a cross-sectional view of a pedicle screw featuring a locking screw head. FIG. 9d is a cross-sectional view of a pedicle screw featuring a head-locking insert. FIG. 10a is a side view of an artificial facet joint of the present invention, featuring a rod having a ball joint. FIG. 10b is a side view of an artificial facet joint featuring a retaining plate. FIG. 10c is a top view of an artificial facet joint featuring a retaining plate. FIG. 11 is a posterior view of the spine after reconstruction and implantation of an artificial functional spinal unit including an expandable intervertebral implant and an artificial facet joint. FIG. 12a is a top view of an expandable PLIF cage in accordance with the present invention. FIG. 12b is a side cross-sectional view of an expandable PLIF cage in accordance with the present invention prior to expansion. FIG. 12c is a side cross-sectional view of an expandable PLIF cage in accordance with the present invention following expansion. FIG. 12d is a side cross-sectional view of an expandable TLIF cage in accordance with the present invention prior to expansion. FIG. 12e is a side cross-sectional view of an expandable TLIF cage in accordance with the present invention following expansion. FIG. 12f is a top view of another expandable cage in accordance with the present invention. FIG. 12g is a side cross-sectional view of the expandable cage of FIG. 12f. FIG. 12h is a cross-sectional view of the expandable cage of FIG. 12f featuring a captive peg. FIG. 12i is a cross-sectional view of an expandable cage featuring a two-dimensional expansion joint. FIG. 13a is a posterior view of a banana-shaped lordotic expandable intervertebral implant. FIG. 13b is a top view of a banana-shaped lordotic expandable intervertebral implant. FIG. 14a is a lateral view of a banana-shaped lordotic expandable intervertebral implant prior to expansion. FIG. 14b is a lateral view of a banana-shaped lordotic expandable intervertebral implant following expansion. FIG. 15a is a side cross-sectional view of an expandable lordotic cage prior to expansion. FIG. 15b is a side cross-sectional view of an expandable lordotic cage following expansion. FIG. 16a is a lateral view of a banana-shaped lordotic expandable intervertebral implant featuring an inclined expansion plate. FIG. 16b is a side cross-sectional view of an expandable lordotic cage featuring an inclined expansion plate. PREFERRED EMBODIMENTS OF THE INVENTION In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. FIGS. 1 and 2 show a round, expandable artificial intervertebral implant designated generally at 10. The device is implemented through a posterior surgical approach by making an incision in the anulus connecting adjacent vertebral bodies after removing one or more facet joints. The natural spinal disc is removed from the incision after which the expandable artificial intervertebral implant is placed through the incision into position between the vertebral bodies. The implant is preferably made of a biocompatible metal having a non-porous quality and a smooth finish, however, it may also be constructed of ceramic or any other suitable inert material. The expandable artificial intervertebral implant 10 generally comprises an upper body 12 and a lower body 14 in a substantially parallel planar configuration. The superior surface 2 of the upper body 12 and the inferior surface 4 of the lower body 14 comprise a machined osteoconductive scaffolding 13 through which the bone may ultimately grow. Osteoconductive scaffolding 13 may also include spines or barbs that project into and secure against the bony endplates of the adjacent bony vertebral bodies upon expansion of the joint and minimize the possibility of sublaxation and/or dislocation. The upper body 12 has a substantially concave inferior surface 16. The lower body 14 has a channel 15 on its superior surface 17. Channel 15 preferably has a rectangular cross-section that extends along the lower body 14 in the medial-lateral direction and substantially conforms to the shape of the upper 12 and lower 14 bodies. An expandablejoint insert 19 resides within the channel 15 on the lower body. The expandable joint insert 19 preferably has a generally flat inferior surface 20 and a substantially convex superior surface 21 that articulates with the substantially concave inferior surface 16 of the upper body 12. The expandable joint insert 19 is lifted from the bottom of channel 15 by means of an expansion screw 21, or other device, that is inserted between the generally flat inferior surface 20 of the expandable joint insert 19 and the bottom of the channel 15 extending along the lower body 14 through an expansion slot 18. A void space is created between the expandable joint insert 19 and the floor of the channel 15 in cross-sections not including the expansion device. A securing means, such as the cables 25, may be employed to ensure the upper body 12 and the lower body 14 remain intact during flexion and extension of the FSU. Alternative means for securing the upper body 12 and lower body 14 may also be employed, such as retaining pegs, torsion springs, or similar devices. FIGS. 3a and 3b show a banana-shaped expandable artificial intervertebral implant 50. As with the round implant 10 shown in FIG. 1, the banana-shaped implant also comprises an upper body 52 and a lower body 54 in a substantially planar configuration, each having an external osteoconductive scaffolding 53. Note that the channel 55 and the expandable joint insert 59, which is disposed within the channel 55, may substantially conform to the shape of the upper 52 and lower 54 bodies. Alternatively, expandable joint insert 59 may have a different shape, such as oval or round, as compared to the shape of the upper 52 and lower 54 bodies. Whereas the round expandable implant may comprise a single expansion device, the banana-shaped implant may contain one or more expansion devices 61 that are inserted into expansion slots 60. Otherwise, the cross-section of the banana-shaped implant is substantially similar to FIG. 2. Turning to FIGS. 4a and 4b, an expandable artificial intervertebral implant is shown in flexion and extension, respectively. The concave inferior surface of 16 of upper body 12 articulates with the convex superior surface 21 of expandable joint insert 19. As stated above, securing means 25 may be employed to prevent dislocation of the implant. FIGS. 5a and 5b illustrate the insertion of expansion devices into a banana-shaped implant. The artificial intervertebral implant 50 in Figure 5a employs expansion screws 70 to expand joint insert 19. One or more expansion screws 70 may be inserted through one or more threaded expansion slots 71. Alternatively, as shown in FIG. 5b, artificial implant 55 may employ a non-threaded expansion device 72 inserted through a non-threaded expansion slot 73 to accomplish the expansion of joint insert 19. The non-threaded expansion slot 73 preferably has an arcuate shape to facilitate insertion after the artificial disc prosthesis has been properly placed within the intervertebral space. The non-threaded expansion device 72 has substantially the same shape as expansion slot 73. A threaded end cap 74 may be employed to retain the expansion device 72 inside the expansion slot 73. FIG. 5c illustrates an alternative means for posteriorly securing an expansion device. Expansion plate 75 is inserted posteriorly into expansion window 76 and slidingly engages the joint insert in the medial-lateral direction. After expansion, stop block 77, which substantially fills expansion window 76 is secured in place with screw 78 or similar device. FIGS. 6a and 6b illustrate an alternative embodiment of a non-threaded expansion device. As shown in FIG. 6a, a banana-shaped artificial intervertebral implant 80 having a wide expansion slot 81 on either the medial or lateral side of the implant 80. Expansion plate 82 may be impacted into place through expansion slot 81 after artificial implant 80 has been properly placed within the intervertebral space. Similar to the previously described embodiments, the artificial implant comprises an upper body 83 and a lower body 84 in a substantially planar configuration, each having an osteoconductive scaffolding 85 machined on their superior and inferior surfaces, respectively. Note that the channel 86, as well as expansion plate 82, substantially conforms to the shape of the upper 83 and lower 84 bodies. Joint insert 87 may generally conform to the shape of the upper 83 and lower 84 bodies, however, the its preferred shape for the banana-shaped implant 80 is more oval, or even more preferably round, to provide improved biomechanical motion of the implant. The bottom floor of channel 86 may also employ a locking lip 88 to ensure that the expansion plate 82 is properly installed and to minimize the potential for dislocating expansion plate 82. FIGS. 6c and 6d illustrate another preferred embodiment of an expandable intervertebral implant featuring retaining pegs 91 to ensure against dislocation of upper body 83 from lower body 84 during flexion, extension and torsional motion. A plurality of retaining pegs 91 project substantially upward form the superior surface of lower body 84. On its' inferior surface, upper body 83 comprises a plurality of holes, or containment wells 90, dimensionally larger than captive pegs 91 and arranged such that when upper body 83 is properly positioned upon lower body 84, captive pegs 91 are housed within containment wells 90. As shown in FIG. 6d, when the intervertebral implant is flexed or extended, captive pegs 91 prohibit dislocation of upper body 83 from lower body 84. While the pegs and containment wells may be any shape, captive pegs 91 are preferably round and containment wells 90 are preferably oval in shape, which gives limited torsional mobility as well. FIGS. 7a and 7b illustrate the expansion of joint insert 19 in more detail. As shown in FIG. 7a and prior to expansion of joint insert 19, upper body 12 rests upon lower body 14 and the generally flat inferior surface 20 of joint insert 19 rests upon the bottom of channel 15, which extends along the lower body 14. Disposed along the generally flat inferior surface 20 of expandable joint insert 19 and adjacent to expansion slot 18, is a lifting notch 17 that engages with the expansion screw 70. Lifting notch 17 facilitates the lifting of expandable joint insert 19 and allows expansion screw 70 to come into contact with the generally flat inferior surface 20 of joint insert 19. Once inserted, as shown in FIG. 7b, the generally flat inferior surface 20 of expandable joint insert 19 rests upon expansion screw 70 and the upper body 12 is lifted above lower body 14 to the desired intervertebral disc height 71. After expansion of the joint insert 19, the implant may be secured in place by employing butress or similar types of screws. FIG. 7c illustrates one embodiment utilizing a butress screw 95. The lower body 14 has a lip 96 projecting from its inferior surface with one or more holes 97 defined therethrough. One or more screws 95 may be inserted through the lip 96 and secured into the vertebral body. Alternatively, when an expansion plate 98 is employed, as shown in FIG. 7d, the expansion plate 98 may comprise a downwardly projecting keel 99 with one or more holes 92 defined therethrough. After the expansion plate 98 is impacted into place, one or more screws 93 may be inserted through the keel 99 and secured into the vertebral body. The expansion plate 98 and lower body 14 may also comprise an interconnecting ridge 94 to secure the expansion plate 98 with lower body 14. Butress screws or the secured keel may be employed with any of the disclosed devices. FIG. 7e illustrates a similar keel arrangement as described above that may be employed with any type of expansion device. One end of the keel 99 is secured onto the lower body 14 of any of the devices disclosed herein. The keel 99 can be rotated after placement of the device in the intervertebral space. After the keel 99 is rotated, it is secured to the vertebral body above or below by one or more screws 95. FIG. 8 shows an expandable artificial intervertebral implant 10 inserted into the spinal column. Note that the expandable artificial implant 10 is posteriorly inserted and expanded through void space 90, which is created by removal of a facet joint. The disclosed techniques of expanding an artificial implant by inserting an expansion plate or similar device may also be employed to expand a PLIF or TLIF cage. As shown in FIGS. 12a, 12b and 12c, a PLIF cage 300 is disclosed comprising a substantially rectangular external cage element 301 housing an internal expandable element 302. The PLIF cage element 301 has an osteoconductive mesh structure 303, in which an osteoconductive substance can be placed, on its inferior surface 304 and an expansion window 305 located on its superior surface 306. The internal expandable element 302 comprises a generally planar plate member 307 having an inferior 308 and superior surface 309. A second osteoconductive mesh structure 310 is secured upon the superior surface 309 of the planar plate member 307 of the internal expandable element 302. The inferior surface 308 of the planar plate member 307 has a lifting notch 311 to facilitate the expansion of the device upon installation of the expansion plate 312. The expansion plate 312 is inserted into the posteriorly located expansion slot 313 of the PLIF external cage element 301 and engages the lifting notch 311 of the planar plate member 307 of the internal expandable element 302. Locking lip 314 located within expansion slot 313 minimizes the potential of expansion plate 312 dislocation. FIGS. 12d and 12e show a TLIF cage similar to the PLIF cage described above. The primary difference between the TLIP cage and the PLIF cage is that the TLIF cage comprises a t-shaped cross-sectional osteoconductive mesh structure 310 secured upon the superior surface 309 of the planar plate member 307 of the internal expandable element 302 such that the osteoconductive mesh structure 310 overhangs the superior surface 306 of the external cage element 301. Thus providing more surface area between the osteoconductive mesh structure 310 and the bony endplates within the intervertebral space. Expandable cages may also be expanded in two dimensions as illustrated in FIG. 12h. Cage element 301 may further comprise an expansion window 320 through its inferior surface and a second internal expandable element 321. As expansion plate 312 is impacted into the device, both internal expandable elements 302, 321 are pushed through their respective expansion windows 305, 320. FIG. 12f and 12g illustrate another preferred embodiment of an expandable cage 900 utilizing the expansion principles disclosed herein. The embodiment generally comprises four parts: an upper body 901, a lower body 902, an expansion joint insert 903, and an expansion screw 904 or similar device. The placement of the device in the spine will determined the preferred shape of the upper and lower bodies 901, 902. The lower body 902 has a recessed channel 905 on it superior surface 906 that houses the joint insert 903 similar to the previously described functional implants. However, the joint insert 903 for this embodiment does not lift above the recessed channel 905 in the lower body 902. The joint insert 903 preferably has a substantially flat inferior surface 906 and one or more angled projections 907 extending upward from its superior surface 908. These angled projections articulate with similar angled projections 909 extending downward from the inferior surface 910 of the upper body 901. As the expansion screw 911 is inserted into the expansion hole 912 in the lower body 902, it forces the joint insert 903 to rotate within the recessed channel 905. As the joint insert 903 rotates, the upper body 901 lifts above the lower body 902 as the angled projections 909 of the upper body 901 slide up the angled projections 907 of the joint insert 903. A captive peg 913 maybe employed to limit the maximum expansion height and to control rotation of the joint insert 903 within the recessed channel 905. One preferred embodiment of an artificial facet joint 100 in accordance with the present invention is shown in FIG. 9a. Artificial facet joint 100 comprises an upper pedicle screw 101 and a lower pedicle screw 102. Rod 103 is retained within the head 104 of upper pedicle screw 101 and the head 105 of lower pedicle screw 102. Rod 103 has washer-type ends 106 that allows for posterior compression, but not extension. Another preferred embodiment of an artificial facet joint 110 is shown in FIG. 9b. Rod 113 comprises a single washer-type end 116 on its lower end 117. The head 115 of upper pedicle screw 112 has a threaded locking screw 118, as shown in FIG. 9c, that holds rod 113 in place and prohibits the head 115 of pedicle screw 112 from swiveling, but allows rod 113 to rotate and translate through the head 115 of pedicle screw 102. FIG. 9d illustrates a head-locking insert that can be used in conjunction with a pedicle screw having a locking type head. The head-locking insert 119 has a similar shape to the head 115 of the pedicle screw. The insert 119 is preferably of solid construction having a hole 120 defined through the insert 119 that substantially aligns with the hole defined through the head 115 of the pedicle screw. As the set screw 118 is engaged into the head 115 of the set screw, force is applied onto the top of the insert 119 and transferred to the bottom of the head 115. The force locks the head 115 of the pedicle screw, as with conventional locking pedicle screws; however, the force is not transferred to rod 113. With no force transferred to the rod 113, it is allowed to freely rotate and translate through the head 115 of the pedicle screw. Alternatively, a shorter insert 119 may be employed that does not prohibit the multi-axial motion of the pedicle screw head. The shorter insert 119 will not transfer the force to the bottom of the head, will retain the rod within the head. Another preferred embodiment of an artificial facet joint 200 is shown in FIG.10a. Artificial facet joint 200 generally comprises an upper pedicle screw 201 and a lower pedicle screw 202 and rod 203 retained within the heads of pedicle screws 201,202. Both pedicle screws 201,202 are secured with locking screws 218 that prevent the heads 204,205 of pedicle screws 201,202 from swiveling, but allow rotation and translation of rod 203. Rod 203 comprises two rod members 206, 207 connected via a ball joint 208. Ball joint 208 allows for a generally upward rotation, away from the bony surfaces of the vertebrae to which they are secured, but prohibit a generally downward rotation, which would bring the ball joint in contact with the vertebrae to which they are secured. Another preferred embodiment of an artificial facet joint is shown in FIGS. 10b and 10c. In this preferred embodiment, the artificial facet joint 250 generally comprises an upper 251 and lower pedicle screw 252 having post-type heads 253,254. Rather than the previously described rod, a retaining plate 255 is employed. Elongated holes 256 are defined through the retaining plate 255, which are positioned upon the post-type heads 253,254 of the pedicle screws 251,252. The post-type heads 251,252 are allowed to move within the elongated holes 256, providing limited range of motion. Employing cushioning pads 257 made of rubber or similar biocompatible material may dampen the movement of the plate. The post-type heads 251,252 may also comprise threaded or lockable caps 258 to prevent dislocation of the plate 255 from the post-type heads 251,252. FIG. 10d illustrates a pedicle screw having a post-type head 253 used in conjunction with a pedicle screw having a locking or non-locking type head 260. Retaining plate 255 is formed with a rod 261 on one end, which is slidingly positioned through pedicle screw 260. As shown in FIG. 10e and 10f, the post-type heads 272 of the pedicle screws used in conjunction with the retaining plate 255 may also exhibit multi-axial motion. The post-type head 272 is attached to the pedicle screw 270 with a ball joint 271. FIG. 10f shows a spacer 274 disposed below retaining plate 255 that allows for rotation of ball joint 271. FIG. 11 shows the artificial facet joint 200 of FIG. 10 in place on the spinal column. Note that artificial intervertebral implant 10 has been posteriorly placed within the intervertebral space through the void created by the surgical removal of the natural facet joint. In addition, ball joint 208 generally rotates in the posterior (upward) direction during posterior compression to prevent impact upon the bony surfaces of the spine. FIGS. 13a, 13b, 14a and 14b illustrate a lordotic, banana-shaped expandable artificial intervertebral implant 400. The lumbar spine is lordotic, thus the anterior disc height is naturally larger than the posterior disc height. Therefore, an expandable artificial intervertebral implant for the lumbar spine must be capable of expanding into a lordotic position. FIG. 13a shows the lordotic expandable artificial intervertebral implant 400 from a posterior view. Lordotic expandable artificial intervertebral implant 400 generally comprises an upper body 412 and a lower hinged body 414 in a substantially planar configuration prior to expansion. The superior surface 402 of the upper body 412 and the inferior surface 404 of the lower hinged body 414 comprise an osteoconductive scaffolding 413 through which the bone may ultimately grow. The upper body 412 has a substantially concave inferior surface 416. The lower hinged body 414 comprises a lower portion 420 and an upper portion 430. Lower portion 420 and upper portion 430 are posteriorly hinged via hinge 440. Hinge 440 effectively fixes the posterior disk height 460 (shown in FIG. 14b). Upper portion 430 of hinged body 414 has a generally flat inferior surface 431 and a substantially convex superior surface 432. The lower portion 420 has a substantially planar configuration prior to expansion. Located at the anterior end 421 of lower portion 420 is a rotational lifting mechanism 422. Once placed in the intervertebral space, the rotational lifting leg is rotationally engaged, thus lifting the anterior end 421 of the expandable artificial intervertebral implant 400 to achieve the desired anterior disc height 470 and proper lordosis. Securing notch 425 is located on the anterior end 421 of the upper portion 430 of hinged body 414. Securing notch 425 engages with rotational lifting mechanism 422 once the expandable artificial intervertebral implant 400 has been expanded. The height of rotational lifting mechanism 422 is determined by the desired proper lordosis when the intervertebral implant 400 is under neutral load. Upper body 412 has a substantially concave inferior surface 416 that articulates with the substantially convex superior surface 432 of upper portion 430 of lower hinged body 414. When viewed in the medial or lateral direction, as shown in FIGS. 14a and 14b, upper body 412 has a downwardly projecting lobe 450 for the attachment of safety bar 452. Safety bar 452 secures upper body 412 to upper portion 430 of lower hinged body 414 and minimizes the possibility of dislocation. FIG. 13b is a top view of lordotic expandable artificial intervertebral implant 400 illustrating the placement of posterior hinge 440, rotational lifting mechanism 422, and safety bar 452 affixed through upper body 412 and upper portion 430 of lower hinged body 414. The rotational lifting mechanism described above may also be employed to achieve proper lordosis with an expandable PLIF and TLIF cage, as shown in FIGS. 15a and 15b. Cage 500 is shown prior to expansion in FIG. 15a and expanded in FIG. 15b. Cage 500 comprises an upper body 502 and a lower body 504. Hinge 506 posteriorly connects upper body 502 to lower body 504 and effectively fixes posterior disc height 510 upon expansion of cage 500. The superior surface 512 of upper body 502 and the inferior surface 514 of lower body 504 may include an osteoconductive scaffolding or mesh 520 as previously described. Expansion of cage 500 is accomplished via rotational lifting mechanism 530, which engages with securing notch 525, located on the anterior end 528 of the inferior surface 513 of upper body 502, and minimizes the potential for dislocation. The height of rotational lifting mechanism 530, which effectively fixes anterior disc height 540, is determined by the desired proper lordosis. Another preferred embodiment of an expandable lordotic artificial intervertebral implant is illustrated in FIGS. 16a and 16b. Lordotic expandable intervertebral implant 600 and lordotic cage 700 both utilize an inclined expansion plate 650 to achieve proper lordosis. Both devices are similar to those described above with the exception of the expansion device and reference is made to FIGS. 14a and 14b for lordotic expandable intervertebral implant 600 and FIGS. 15a and 15b for lordotic cage 700 for elements of the intervertebral implants already identified. Expansion plate 650 is generally wedged-shaped and comprises a lifting notch 620 on its posterior end 622 to facilitate expansion. As shown in FIG. 16a, expansion plate 650 is installed between the upper portion 430 and lower portion 420 of lower hinged body 414. Located on the superior surface 630 at the anterior end 624 is securing ridge 635. Securing ridge 635 engages with securing notch 625 similar to the rotational lifting mechanism described above. Located on the anterior superior surface of lower portion 420 of lower hinged body 414 is a locking lip 637, which minimizes the potential of dislocating inclined expansion plate 650. FIG. 16b illustrate the use of expansion plate 650 in conjunction with lordotic cage 700. Although the present invention has been described in terms of specific embodiments, it is anticipated that alterations and modifications thereof will no doubt become apparent to those skilled in the art. It is therefore intended that the following claims be interpreted as covering all alterations and modifications that fall within the true spirit and scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>The human spine is a complex mechanical structure composed of alternating bony vertebrae and fibrocartilaginous discs that are connected by strong ligaments and supported by musculature that extends from the skull to the pelvis and provides axial support to the body. The intervertebral discs primarily serve as a mechanical cushion between adjacent vertebral segments of the spinal column and generally comprise three basic components: the nucleus pulposus, the anulus fibrosis, and two vertebral end plates. The end plates are made of thin cartilage overlying a thin layer of hard cortical bone that attaches to the spongy, cancellous bone of the vertebral body. The anulus fibrosis forms the disc's perimeter and is a tough outer ring that binds adjacent vertebrae together. The vertebrae generally comprise a vertebral foramen bounded by the anterior vertebral body and the neural arch, which consists of two pedicles and two laminae that are united posteriorly. The spinous and transverse processes protrude from the neural arch. The superior and inferior articular facets lie at the root of the transverse process. The term “functional spinal unit” (“FSU”) refers to the entire motion segment: the anterior disc and the posterior facet joints, along with the supporting ligaments and connective tissues. The spine as a whole is a highly flexible structure capable of a high degree of curvature and twist in nearly every direction. However, genetic or developmental irregularities, trauma, chronic stress, and degenerative wear can result in spinal pathologies for which surgical intervention maybe necessary. It is common practice to remove a spinal disc in cases of spinal disc deterioration, disease or spinal injury. The discs sometimes become diseased or damaged such that the intervertebral separation is reduced. Such events cause the height of the disc nucleus to decrease, which in turn causes the anulus to buckle in areas where the laminated plies are loosely bonded. As the overlapping laminated plies of the anulus begin to buckle and separate, either circumferential or radial anular tears may occur. Such disruption to the natural intervertebral separation produces pain, which can be alleviated by removal of the disc and maintenance of the natural separation distance. In cases of chronic back pain resulting from a degenerated or herniated disc, removal of the disc becomes medically necessary. In some cases, the damaged disc may be replaced with a disc prosthesis intended to duplicate the function of the natural spinal disc. U.S. Pat. No. 4,863,477 discloses a resilient spinal disc prosthesis intended to replace the resiliency of a natural human spinal disc. U.S. Pat. No. 5,192,326teaches a prosthetic nucleus for replacing just the nucleus portion of a human spinal disc. In other cases it is desired to fuse the adjacent vertebrae together after removal of the disc, sometimes referred to as “intervertebral fusion” or “interbody fusion.” Many techniques and instruments have been devised to perform intervertebral fusion. There is common agreement that the strongest intervertebral fusion is the interbody (between the lumbar bodies) fusion, which may be augmented by a posterior or facet fusion. In cases of intervertebral fusion, either structural bone or an interbody fusion cage filled with morselized bone is placed centrally within the space where the spinal disc once resided. Multiple cages or bony grafts may be used within that space. Such practices are characterized by certain disadvantages, most important of which is the actual morbidity of the procedure itself. Placement of rigid cages or structural grafts in the interbody space either requires an anterior surgical approach, which carries certain unavoidable risks to the viscous structures overlying the spine (intestines, major blood vessels, and the ureter), or they may be accomplished from a posterior surgical approach, thereby requiring significant traction on the overlying nerve roots. The interval between the exiting and traversing nerve roots is limited to a few millimeters and does not allow for safe passage of large intervertebral devices, as may be accomplished from the anterior approach. Alternatively, the anterior approach does not allow for inspection of the nerve roots, is not suitable alone for cases in which the posterior elements are not competent, and most importantly, the anterior approach is associated with very high morbidity and risk where there has been previous anterior surgery. Another significant drawback to fusion surgery in general is that adjacent vertebral segments show accelerated deterioration after a successful fusion has been performed at any level. The spine is by definition stiffer after the fusion procedure, and the natural body mechanics place increased stress on levels proximal to the fused segment. Other drawbacks include the possibility of “flat back syndrome” in which there is a disruption in the natural curvature of the spine. The vertebrae in the lower lumbar region of the spine reside in an arch referred as having a sagittal alignment. The sagittal alignment is compromised when adjacent vertebral bodies that were once angled toward each other on their posterior side become fused in a different, less angled orientation relative to one another. Finally, there is always the risk that the fusion attempt may fail, leading to pseudoarthrosis, an often painful condition that may lead to device failure and further surgery. Conventional interbody fusion cages generally comprise a tubular metal body having an external surface threading. They are inserted transverse to the axis of the spine, into preformed cylindrical holes at the junction of adjacent vertebral bodies. Two cages are generally inserted side by side with the external threading tapping into the lower surface of the vertebral bone above, and the upper surface of the vertebral bone below. The cages include holes through which the adjacent bones are to grow. Additional materials, for example autogenous bone graft materials, maybe inserted into the hollow interior of the cage to incite or accelerate the growth of the bone into the cage. End caps are often utilized to hold the bone graft material within the cage. These cages of the prior art have enjoyed medical success in promoting fusion and grossly approximating proper disc height. As previously discussed, however, cages that would be placed from the safer posterior route would be limited in size by the interval between the nerve roots. It would therefore, be a considerable advance in the art to provide a fusion implant assembly which could be expanded from within the intervertebral space, thereby minimizing potential trauma to the nerve roots and yet still providing the ability to restore disc space height. Ultimately though, it is important to note that the fusion of the adjacent bones is an incomplete solution to the underlying pathology as it does not cure the ailment, but rather simply masks the pathology under a stabilizing bridge of bone. This bone fusion limits the overall flexibility of the spinal column and artificially constrains the normal motion of the patient. This constraint can cause collateral injury to the patient's spine as additional stresses of motion, normally borne by the now-fused joint, are transferred onto the nearby facet joints and intervertebral discs. Thus, it would be an even greater advance in the art to provide an implant assembly that does not promote fusion, but instead closely mimics the biomechanical action of the natural disc cartilage, thereby permitting continued normal motion and stress distribution. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, an artificial functional spinal unit (FSU) is provided comprising, generally, an expandable artificial intervertebral implant that can be placed via a posterior surgical approach and used in conjunction with one or more artificial facet joints to provide an anatomically correct range of motion. Expandable artificial intervertebral implants in both lordotic and non-lordotic designs are disclosed, as well as lordotic and non-lordotic expandable cages for both PLIF (posterior lumber interbody fusion) and TLIF (transforaminal lumbar interbody fusion) procedures. The expandable implants may have various shapes, such as round, square, rectangular, trapezoidal, banana-shaped, kidney-shaped, or other similar shapes. By virtue of their posteriorly implanted approach, the disclosed artificial FSU's allow for posterior decompression of the neural elements, reconstruction of all or part of the natural functional spinal unit, restoration and maintenance of lordosis, maintenance of motion, and restoration and maintenance of disc space height. The posterior implantation of an interbody device provides critical benefits over other anterior implanted devices. Placement of posterior devices that maintain mobility in the spine have been limited due to the relatively small opening that can be afforded posteriorly between the exiting and transversing nerve roots. Additionally, placement of posterior interbody devices requires the removal of one or both facet joints, further destabilizing the spine. Thus conventional posteriorly placed interbody devices have been generally limited to interbody fusion devices. Since a properly functioning natural FSU relies on intact posterior elements (facet joints) and since it is necessary to remove these elements to place a posterior interbody device, a two-step procedure is disclosed that allows for placement of an expandable intervertebral implant and replacement of one or both facets that are necessarily removed during the surgical procedure. The expansile nature of the disclosed devices allow for restoration of disc height once inside the vertebral interspace. The expandable devices are collapsed prior to placement and then expanded once properly inserted in the intervertebral space. During the process of expansion, the endplates of the natural intervertebral disc, which essentially remain intact after removal or partial removal of the remaining natural disc elements, are compressed against the device, which thereby facilitates bony end growth onto the surface of the artificial implant. Once the interbody device is in place and expanded, the posterior element is reconstructed with the disclosed pedicle screw and rod system, which can also be used to distract the disk space while inserting the artificial implant. Once the interbody device is in place and expanded, the posterior element is further compressed, again promoting bony end growth into the artificial implant. This posterior compression allows for anterior flexion but replaces the limiting element of the facet and interspinous ligament and thereby limits flexion to some degree, and in doing so maintains stability for the anteriorly located interbody device. The posterior approach avoids the potential risks and morbidity of the anterior approach, which requires mobilization of the vascular structures, the ureter, and exposes the bowels to risk. Also, the anterior approach does not offer the surgeon an opportunity to view the posterior neural elements and thereby does not afford an opportunity for decompression of those elements. Once an anterior exposure had been utilized a revision procedure is quite risky and carries significant morbidity. While the posterior surgical approach is preferred, there may be circumstances that prevent posterior placement. If an anterior approach must be performed, the disclosed devices may be inserted anteriorly without affecting functionality. The artificial FSU generally comprises an expandable intervertebral implant and one or more artificial facet joints. The expandable intervertebral implant generally comprises a pair of spaced apart plate members, each with a vertebral body contact surface. The general shape of the plate members may be round, square, rectangular, trapezoidal, banana shaped, kidney shaped, or some other similar shape, depending on the desired vertebral implantation site. Because the artificial intervertebral implant is to be positioned between the facing surfaces of adjacent vertebral bodies, the plate members are arranged in a substantially parallel planar alignment (or slightly offset relative to one another in accordance with proper lordotic angulation) with the vertebral body contact surfaces facing away from one another. The plate members are to mate with the vertebral bodies so as to not rotate relative thereto, but rather to permit the spinal segments to axially compress and bend relative to one another in manners that mimic the natural motion of the spinal segment. This natural motion is permitted by the performance of an expandable joint insert, which is disposed between the plate members. The securing of the plate members to the vertebral bone is achieved through the use of a osteoconductive scaffolding machined into the exterior surface of each plate member. Alternatively, a mesh of osteoconductive surface may be secured to the exterior surface of the plate members by methods known in the art. The osteoconductive scaffolding provides a surface through which bone may ultimately grow. If an osteoconductive mesh is employed, it may be constructed of any biocompatible material, both metal and non-metal. Each plate member may also comprise a porous coating (which may be a sprayed deposition layer, or an adhesive applied beaded metal layer, or other suitable porous coatings known in the art, i.e. hydroxy appetite). The porous coating permits the long-term ingrowth of vertebral bone into the plate member, thus permanently securing the prosthesis within the intervertebral space. In more detail, the expandable artificial implant of the present invention generally comprises four parts: an upper body, a lower body, an expandable joint insert, that fits into the lower body, and an expansion device, which may be an expansion plate, screw, or other similar device. The upper body generally comprises a substantially concave inferior surface and a substantially planar superior surface. The substantially planar superior surface of the upper body may have some degree of convexity to promote the joining of the upper body to the intact endplates of the natural intervertebral disc upon compression. The lower body generally comprises a recessed channel, having a rectangular cross-section, which extends along the superior surface of the lower body in the medial-lateral direction and substantially conforms to the shape of the upper and lower bodies. The lower body further comprises a substantially planar inferior surface that may have some degree of convexity to promote the joining of the lower body to the intact endplates of the natural intervertebral disc upon compression. The expandable joint insert resides within the channel on the superior surface of the lower body. The expandable joint insert has a generally flat inferior surface and a substantially convex superior surface that articulates with the substantially concave inferior surface of the upper body. Prior to expansion of the artificial implant, the generally flat inferior surface of the expandable joint insert rests on the bottom surface of the channel. The expandable joint insert is raised above the bottom of the channel by means of an expansion screw, an expansion plate, or other similar device, that is inserted through an expansion hole or slot. The expansion hole or slot is disposed through the wall of the lower body formed by the channel. The expansion hole or slot gives access to the lower surface of the channel and is positioned such that the expansion device can be inserted into the expansion hole or slot via a posterior surgical approach. As the expansion device is inserted through the expansion slot, into the channel, and under the expandable joint insert, the expandable joint insert is raised above the floor of the channel and lifts the upper body above the lower body to the desired disc height. The distance from the inferior surface of the lower body and the superior surface of the upper body should be equal to the ideal distraction height of the disk space. As the artificial implant is flexed and extended, the convex superior surface of the expandable joint insert articulates with the concave inferior surface of the upper body. After the insertion and expansion of the expandable intervertebral implant, the posterior facet joints may be reconstructed by employing the disclosed artificial facet joints. One embodiment of the artificial facet joint generally comprises a lower and upper multi-axial pedicle screw joined by a rod bridging the vertebral bodies above and below the artificial implant. The rod comprises a washer-type head at its lower (caudad) end. The rod fits into the heads of the pedicle screws and a top loaded set screw is placed in the pedicle screw heads. The disclosed pedicle screw system may employ different types of pedicle screws so that the top loaded set screw may or may not lock down on the rod depending on surgeon preference. If a non-locking pedicle screw is used the caudad end remains fully multi-axial. The upper (cephalad) end of the rod is held within the head of the upper pedicle screw with a set screw which locks down on the rod and eliminates any rod movement at the cephalad end, which by nature has limited multi-axial function. In an alternative embodiment of an artificial facet joint, the rod may comprise washer-type heads on both ends (caudad and cephalad) so that both pedicle screws can be of the non-locking variety. In the event of a two level surgical procedure, three pedicle screws would be employed with a single rod, which would have washer-type heads at both ends. The middle pedicle screw would be a locking-type and the upper most and lower most pedicle screws would be of the non-locking variety. In addition, another embodiment of the artificial facet joint is disclosed that generally comprises two locked pedicle screws joined by a rod having a ball and socket joint centrally located on the rod between the two pedicle screws. The locking of the pedicle screws prevents the screw head from swiveling, but allows rotation and translation of the rod. While conventional locking type pedicle screws may be employed, a novel locking type pedicle screw is also disclosed. Locking type pedicle screws comprise a set screw located in the pedicle screw head, which applies force to the retaining rod as it is tightened. One the set screw is tightened, rotational and translational movement of the rod within the head of the pedicle screw is prohibited. In addition, the multi-axial movement of the pedicle screw head is also prohibited making the entire assembly a fixed structure. By employing the rod holding device described in detail below, the set screw can be tightened and the multi-axial movement of the pedicle screw head can be prohibited without limiting the translational and rotational movement of the retaining rod. The rod holding device generally comprises a solid insert fitting within the pedicle screw head with a hole in which the retaining rod is slidingly positioned. As the set screw is tightened, force is applied to the rod holding device and transferred to the bottom of the pedicle screw head without applying force to the retaining rod. This allows fixation of the pedicle screw head without limiting movement of the retaining rod. In another preferred embodiment, the artificial facet joint generally comprises an upper and lower pedicle screw having post-type heads. Rather than the previously described rod, a retaining plate is employed. Elongated holes are defined through the retaining plate, which are positioned upon the post-type heads of the pedicle screws. The post-type heads are allowed to move within the elongated holes, providing limited range of motion. Employing cushioning pads made of rubber or similar biocompatible material may dampen the movement of the plate. The post-type heads may also comprise threaded or lockable caps to prevent dislocation of the plate from the post-type heads. In instances where a fusion procedure is unavoidable, a PLIF and TLIF cages are disclosed that utilize the expansion principal of the functional artificial intervertebral implant. One embodiment of the PLIF and TLIF cages generally comprises three parts: An external body, an internal body, and an expansion device. The external and internal bodies will have substantially the same shape and will be shaped accordingly to the procedures for which they will be used, more specifically, a rectangular cage is preferred for a PLIF procedure and round or banana shaped cage is preferred for the TLIF procedure. Both the external and internal bodies comprise a mesh structure in which an osteoconductive substance can be placed (i.e. morsilized autograph or an osteobiologic substitute). The external body of the cage contains an internal void space that houses the internal body. The external body further comprises an expansion window on its superior surface through which the internal body is raised upon expansion of the cage. The internal body comprises a planar plate member that is slightly larger than the expansion window in the superior surface of the external body such that when the cage is expanded the planar plate member secures itself against the interior side of the expansion window, thereby interlocking the external and internal bodies and eliminating mobility between the two bodies. Similar to the functional expandable implant, an expansion device is placed through an expansion slot. The expansion device lifts the internal body relative to the external body, interlocking the planar plate member of the internal body against the interior of the expansion window, and pushing the mesh structure of the internal body through the expansion window and above the superior surface of the external body. Varying the height of the expansion device and the dimensions of the external and internal bodies allows for various distraction heights to regain disc space. As with the functional intervertebral implant, the PLIF and TLIF cages may take the form of either an expandable lordotic cage or a non-lordotic cage. In another embodiment of the PLIF and TLIF cage, a joint insert is employed that is similar to that used in the functional implant. This embodiment generally comprises four parts: an upper body, a lower body, an expandable joint insert that fits into the lower body, and an expansion screw or other similar device. The upper body generally comprises a substantially planar superior surface and one or more angled projections extending downward from the upper body's inferior surface. The substantially planar superior surface of the upper body may have some degree of convexity to promote the joining of the upper body to the intact endplates of the natural intervertebral disc upon compression. The lower body generally comprises a recessed channel, preferably having a rectangular cross-section, which extends along the superior surface of the lower body in the medial-lateral direction. The lower body further comprises a substantially planar inferior surface that may have some degree of convexity to promote the joining of the lower body to the intact endplates of the natural intervertebral disc upon compression. The expandablejoint insert resides within the channel on the superior surface of the lower body. The expandable joint insert has a generally flat inferior surface and one or more angled projections extending upward from the superior surface of the joint insert that are in communication with the angled projections extending downward from the inferior surface of the upper body. Expansion is accomplished by utilizing as expansion screw or other similar device through an expansion hole disposed through the lower body. Insertion of the expansion screw forces the one or more angled projections of the expansion joint insert to articulate against the one or more angled projections of the upper body causing the upper body to lift above the lower body. The maximum expansion height may be limited by employing one or more retaining pegs. The retaining pegs also prohibit dislocation and rotation of the upper body relative to the lower body. The shapes and sizes of all of the devices disclosed herein are dependent upon the surgical approach employed to insert the device and the position in the spine in which it is placed. Generally, they will range from about 6 to about 11 millimeters in height for cervical devices and about 10 to about 18 millimeters in height for lumbar devices. However some deviation from these ranges may occur from patient to patient. Round devices will preferably range from about 14 to about 26 millimeters in diameter. Square devices will preferably range from about 14×14 to about 26×26 millimeters. Rectangular and trapezoidal devices will preferably range from about 12 millimeters along its shortest side and to about 30 millimeters along its longest side. | 20040212 | 20110322 | 20050210 | 79495.0 | 1 | SCHILLINGER, ANN M | ARTIFICIAL SPINAL UNIT ASSEMBLIES | SMALL | 1 | CONT-ACCEPTED | 2,004 |
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10,777,599 | ACCEPTED | Voltage level shifter | A voltage level shifter is provided. The shifter includes an AND gate for generating a synchronizing signal according to a periodic signal and a primitive input signal. The synchronizing signal and a first periodic control signal that are in phase with the periodic control signal are inputted to a transistor device. The transistor device is constructed with an inverter. The voltage level shifter further includes a buffer for generating an output signal and a capacitor for storing a signal. The present invention also provides a switching circuit for preventing the turning on of both PMOS transistor and NMOS transistor simultaneously during a switching status. The present invention can also solve the issue caused by the ratio of the channel width to the channel length, thus the uncertainty of the manufacturing process will not affect the circuit. Therefore, the power consumption, the chip area and the cost are reduced. | 1. A voltage level shifter, comprising: an AND gate for processing a first control signal and an input signal to produce a synchronizing signal, wherein the first control signal is a periodic signal; a transistor device having a first transistor and a second transistor, wherein a drain of the first transistor and a drain of the second transistor are electrically connected, a source of the first transistor then is electrically connected to a ground and a source of the second transistor is electrically connected to a voltage source, a gate of the first transistor is electrically connected to the synchronizing signal and a gate of the second transistor is electrically connected to the first control signal; a buffer for producing an output signal, wherein an input terminal of the buffer is a first contact point and electrically connected to the drain of the first transistor and the drain of the second transistor; and a capacitor, wherein one terminal of the capacitor is electrically connected to the first contact point for storing a signal level of the first contact point, and the other terminal of the capacitor is electrically connected to the ground. 2. The voltage level shifter of claim 1, wherein the first transistor comprises an n-type metal oxide semiconductor, wherein the n-type metal oxide semiconductor comprises a NMOS transistor. 3. The voltage level shifter of claim 1, wherein the second transistor comprises a p-type metal oxide semiconductor, wherein the p-type metal oxide semiconductor comprises a PMOS transistor. 4. The voltage level shifter of claim 1 further comprising: a switch, controlled by the first control signal, wherein one terminal of the switch is electrically connected to the first contact point and the other terminal of the switch is electrically connected to the drain of the first transistor. 5. The voltage level shifter of claim 4, wherein the switch comprises an n-type metal oxide semiconductor. 6. The voltage level shifter of claim 4, wherein the AND gate and the transistor device are combined into a circuit device, the circuit device comprising: a third transistor electrically connected to the voltage source; a fourth transistor; and a fifth transistor electrically connected to the ground, wherein the third transistor comprises a PMOS transistor, the fourth and fifth transistors comprise NMOS transistors, a gate of the third transistor is electrically connected to the first control signal, a gate and a drain of the fourth transistor is electrically connected to the first control signal and the switch respectively, and a gate of the fifth transistor is electrically connected to the input signal. 7. The voltage level shifter of claim 1, wherein the buffer comprises an inverter having at least a PMOS transistor and a NMOS transistor. 8. The voltage level shifter of claim 1, wherein the capacitor comprises a parasitic capacitor for a transistor. 9. The voltage level shifter of claim 1, further comprising: a sixth transistor; a seventh transistor; and a second control signal; wherein the capacitor is electrically connected to the sixth transistor, in which a drain, a gate and a source of the sixth transistor are electrically connected to the first contact point, the output terminal of the buffer, and the seventh transistor respectively, a gate of the seventh transistor is electrically connected to a second control signal, and the sixth and seventh transistors are both PMOS transistors. 10. The voltage level shifter of claim 1, wherein the first control signal is a periodic negative pulse and the second control signal is a periodic positive pulse, wherein the first control signal and the second control signal are synchronized and a width of the negative pulse is narrower than the width of the positive pulse. 11. The voltage level shifter of claim 1, wherein the AND gate comprises a low voltage transistor device, and the transistor device, the buffer and the capacitor comprise high voltage transistor devices. 12. The voltage level shifter of claim 1, wherein the first control signal inputted to the AND gate comprises a low voltage signal, and the first control signal inputted to the second transistor is adjusted to comprise a high voltage signal having a phase the same as a phase of the first control signal inputted to the AND gate. 13. The voltage level shifter of claim 9, wherein the third, fourth, fifth, sixth and seventh transistors comprise high voltage field effect transistor devices. 14. A voltage level shifter, comprising: a switch device; an input transistor device comprises: a first transistor, electrically connected to a voltage source; a second transistor and a third transistor, both electrically connected to a ground; wherein the first transistor is a PMOS transistor, the second and third transistors are NMOS transistors, a gate of the first transistor and a gate of the second transistor are electrically connected to the first control signal, a gate of the third transistor is electrically connected to an input signal, a drain of the second transistor is electrically connected to the switch, and the first and second transistors are electrically connected at a first contact point; wherein the switch is controlled by a first control signal, in which one terminal of the switch is electrically connected to the first contact point; a capacitor, electrically connected to the other terminal of the switch at a second contact point; and a buffer, electrically connected to the second contact point. 15. The voltage level shifter of claim 14, wherein the capacitor comprises a parasitic capacitor for a transistor. 16. The voltage level shifter of claim 14, further comprising: a fourth transistor; a fifth transistor; and a second control signal; wherein the capacitor is electrically connected to the fourth transistor, in which a drain, a gate and a source of the fourth transistor are electrically connected to the second contact point, an output terminal of the buffer and the fifth transistor respectively, a gate of the fifth transistor is electrically connected to the second control signal, and the fourth and the fifth transistors are PMOS transistors. 17. The voltage level shifter of claim 14, wherein the first control signal is a periodic negative pulse and the second control signal is a periodic positive pulse, the first and the second control signals are synchronized and a width of the negative pulse is narrower than a width of the positive pulse. 18. The voltage level shifter of claim 16, wherein the first, second, third, fourth and fifth transistors and the buffer comprise high voltage field effect transistor devices. | CROSS-REFERENCE TO RELATED APPLICATION This application claims the priority benefit of Taiwan application serial no. 92129089, filed on Oct. 21, 2003. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is generally related to a voltage level shifter. More particularly, the present invention relates to a voltage level shifter suitable for a driving circuit of a liquid crystal display (LCD), wherein the direct current (DC) path thereof may be broken for preventing the turning on of PMOS transistor and NMOS transistors simultaneously. Therefore, the DC power consumption is reduced, and the layout of the circuit and chip area are also reduced. 2. Description of the Related Art In general, an output stage of a conventional voltage level shifter constructed by metal oxide semiconductors (MOS) includes at least an inverter for buffering. The inverter usually includes a PMOS transistor and a NMOS transistor. The problem generated in the conventional design is that it is hard to control the timing of switching the status between the transistors when the voltage level is changed. It is preferable to minimize the time for turning on both the PMOS transistor and the NMOS transistors during the switching to minimize the power consumption. However, even though the ratio of the channel width to the channel length has been considered carefully and designed, the uncertainty during the manufacturing process will still generate a considerable DC power consumption. FIG. 4 is a circuit diagram schematically illustrating a conventional voltage level shifter. Referring to FIG. 4, the conventional voltage level shifter includes a differential input for NMOS transistors 411 and 415. The output stage of the voltage level shifter includes a PMOS transistor 403 and a NMOS transistor 413, and the output stage is provided for an inverter 431. The inverter 431 can be, for example, a high voltage inverter. In addition, there is another inverter 433 electrically connected to the transistors 411 and 415. The inverter 433 usually comprises a low voltage inverter because the driving power of the inverter 433 is less than the inverter 431. Moreover, the inverter 433 is provided for converting the input clock transistor-transistor logic (TTL) voltage signal VIN to a differential input. Referring to FIG. 9, when the input is a clock signal and the clock TTL signal is changed from low to high, the inverter 433 inverts the input signal and outputs a signal to a gate of the transistor 411, in which the outputted signal is delayed a little after the VIN. Therefore, there is an extremely short period of time that a gate of the PMOS transistor 405 is at analog high voltage low level GNDA when the NMOS transistor 415 is turned on and the NMOS transistor 411 is not turned off. Thus, when the PMOS transistor 405 is still on, the PMOS transistor 405 and the NMOS transistor 415 are turned on at the same time. Thus, as shown in FIG. 9, current I(415) has a surge at the beginning of each input cycle. Moreover, for generating the differential input signal pair, the PMOS transistor requires a very fast switching in order that the NMOS transistor can control the gate of the PMOS transistor within a short time. Thus, the ratio of the channel width to the channel length of the transistors is designed to achieve the desired effects described above. Typically, the NMOS transistor is designed to have a smaller impedance, i.e., with channel having a wider width and a shorter length, and the PMOS transistor is designed to have a larger impedance, i.e., with a channel having a narrower width and a longer length. Similarly, referring to FIG. 4 and FIG. 9, when the input clock signal is changed from high to low, the NMOS transistor 415 is turned off. At this moment, the gate of the NMOS transistor 411 is not turned on due to a time delay, therefore, the transistor 411 is at a high impedance state. During this time, a gate of the PMOS transistor 401 is at low voltage level, thus the PMOS transistor 401 is still on. Therefore, another conducting path is generated by the PMOS transistor 401 when the NMOS transistor 411 is changed from low to high level, and a current I(411) will generate a surge at this time. Thus, the breaking of the conducting path between the high voltage and the ground is required in order to reduce the power consumption during the turning on of both of the PMOS transistor and NMOS transistors to reduce the power consumption of the analog circuit. Furthermore, the voltage level shifter that applies to a driving circuit of a LCD occupies significant chip area. The chip area can be more compact if the ratio of the channel width to the channel length is not an issue. Therefore, a voltage level shifter that can reduce the power consumption and the chip area to lower down the cost is required. SUMMARY OF THE INVENTION The present invention is to provide a voltage level shifter wherein the current path between the high voltage level and the ground are completely broken. Another objective of the present invention is to provide a voltage level shifter wherein the ratio of the channel width to the channel length of the transistors is not a major issue in the circuit design. Another objective of the present invention is to provide a voltage level shifter suitable for a driving circuit of a LCD, wherein the chip area is substantially reduced due to the repeating of some circuits. The present invention provides at least one voltage level shifter for breaking the current path and for turning on the PMOS transistor and NMOS transistors connected in serial in the circuit at different times. Thus, an input/output control sequence is required. The present invention provides many different input/output timing sequences in the embodiments that can achieve the desired results. This invention may, however, be embodied in many other different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete, To begin with, an output stage of a voltage level shifter is an inverter. When an input signal of the shifter is at low voltage level, an output signal from the output stage is also at low voltage level. A PMOS transistor should have been turned off before a NMOS transistor is turned on when the input signal is changed from low level to high level. Thus, a control signal is provided with a time period in front of the input signal. The input signal and the control signal are processed by an inverter, thus the PMOS transistor is at a high impedance during the rising of the control signal and the rising of the input signal. During this time, the output stage outputs a low voltage signal and a capacitor stores the original high voltage level of the output stage. The NMOS transistor is turned on when the input signal is changed from low to high level. The NMOS transistor pulls down the voltage stored in the capacitor to low voltage level. At the same time, an inverter pulls up an output terminal to high voltage level. Similarly, the NMOS transistor should have been turned off before the PMOS transistor turns on when the input signal changes from high to low level. In other words, the NMOS transistor should also be at high impedance state for another time period before the PMOS transistor is turned on. The capacitor is maintained at the ground level and then the PMOS transistor is turned on, thus a high voltage level is achieved within a short time. During this time, the output stage outputs a low voltage signal. Therefore, the control signal has a direct impact on the operation of the circuit. However, the PMOS transistor is turned on when the control signal is periodic and the input signal is at high voltage level. The capacitor is charged up from the ground to high voltage level within a short period of time, and thus an error output is generated. Thus, a switch transistor is connected in between the NMOS transistor and the capacitor for producing another control signal to break the charging path. As a result, the voltage level of the capacitor is maintained. The capacitor keeps to perform the same operation as previously described when the control signal changes back to low voltage level again. As a simplified version of the present invention, an AND gate of the input terminal, the PMOS transistor and the NMOS transistor can be three transistors connected in series. The sequence of the connection from high voltage level to the ground includes a first PMOS transistor, a first NMOS transistor and a second NMOS transistor. Wherein, a gate of the second NMOS transistor is electrically connected to the input signal. A gate of the first PMOS transistor and a gate of the first NMOS transistor are electrically connected to a first control signal. Moreover, the transistor in a buffer (for example, an inverter described above) has to be in a proper size in order to drive the next output. Moreover, the capacitor, for example, can be comprised of a second PMOS transistor and a third PMOS transistor connected in series. Wherein, the second PMOS transistor is electrically connected to a high voltage level and a gate of the second PMOS transistor is electrically connected to a second control signal. The third PMOS transistor is electrically connected to the buffer (for example, an inverter), and thus a latch circuit is provided. Furthermore, the switch transistor, for example, can be comprised of a third NMOS transistor. The PMOS transistors can be designed in any size, for example, be high voltage transistors. Thus, the uncertainty generated from the manufacturing process is reduced and the stability of the circuit is enhanced. The first control signal produces a negative pulse with very narrow width when the inputted clock signal changes from low to high voltage level. During this time, the second NMOS transistor is turned on and the first control signal changes to low voltage level. As a result, the first and third NMOS transistors are turned off, the first PMOS transistor is turned on and the capacitor keeps the same voltage level. At the same time, the second control signal inputs a positive pulse with a wider pulse width than the pulse width of the first control signal. During this time, the second PMOS transistor is turned off. Thus, a high impedance path is formed between the second and third PMOS transistors. Moreover, the first and third NMOS transistors are turned on and the first PMOS transistor is turned off when the negative pulse from the first control signal ends. At the same time, the capacitor discharges to low voltage level and the output signal changes to high voltage level. The third PMOS transistor turns off due to high voltage level in the output. Although the second PMOS transistor conducts when the positive pulse of the second control signal is off, but because the third PMOS transistor remains in the off state, a high impedance path is formed between the second and third PMOS transistors and the capacitor maintains the low voltage level. In the case when the input clock signal is at high voltage level and the first control signal and the second control signal provide a negative pulse and a positive pulse respectively, the first PMOS transistor is turned on. During this time, the first and third NMOS transistors are turned off and the voltage level of the capacitor remains the same as previous. Similarly, the first control signal produces a negative pulse with very narrow width when input a clock signal that changes from high to low voltage level. During this time, the second NMOS transistor turns on and the first control signal changes to low voltage level. As a result, the first and third NMOS transistors are turned off, the first PMOS transistor is turned on and the capacitor maintains the same voltage level. Moreover, the first and third NMOS transistors are turned on and the first PMOS transistor is turned off when the negative pulse from the first control signal ends. The second NMOS transistor is turned off because the original input signal is at low voltage level. Hence, the second PMOS transistor temporarily acts as a parasitic capacitor before the positive pulse from the second control signal ends. During this time, the second PMOS transistor is at high impedance state and the output signal is at low voltage level. The second PMOS transistor conducts after the positive pulse from the second control signal ends. Thus, the second and third PMOS transistors form a conducting path. At this time, the capacitor is at high voltage level. Similarly, in the case when the input clock signal is at low voltage level and the first control signal and the second control signal provide a negative pulse and a positive pulse respectively, the first PMOS transistor is turned on. During this time, the first and third NMOS transistors are turned off and the voltage level of the capacitor remains the same as previous. Immediately after that, the third PMOS transistor temporarily (with high impedance) acts as a parasitic capacitor for a short period of time (Td). Moreover, both of the first and second control signals (for example, high voltage control signals) use positive/negative pulses as the controlling signals to control a voltage level shifter. The first control signal and second control signal provide a negative pulse and a positive pulse respectively when the input status is changed. The width of a negative pulse should be slightly wider than the width of a positive pulse because the time periods between the positive pulse and the negative pulse inevitably results in high impedance. The slightly wider negative pulse also prevents damages resulted from the second and third PMOS transistors being conducted to the first, second and third NMOS transistors when the input signal is at high voltage level. Moreover, the first PMOS transistor, the first and third NMOS transistors form conducting paths when the input signal is changed to a high voltage level. Furthermore, the first PMOS transistor and the first NMOS transistor produce smaller surges compared to that of the prior art since the first PMOS transistor/NMOS transistor can be designed in many ways. Similarly, the buffer of the output stage (the buffer comprises an inverter made from PMOS transistor/NMOS transistor) also results in a smaller surge (compared to prior art) when the input clock signal is changed from high to low voltage level. Accordingly, in the voltage level shifter of the present invention, two control signals are provided to turn on and off the PMOS transistor and NMOS transistors, thus the power consumption during the turning on of the PMOS transistor and NMOS transistors is reduced. Moreover, the current path between the high voltage level and the ground are also broken totally by the two control signals reducing the power consumption of the analog circuit. It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. FIG. 1 is a circuit diagram schematically illustrating a voltage level shifter according to one preferred embodiment of the present invention. FIG. 2 is a circuit diagram schematically illustrating a voltage level shifter according to another preferred embodiment of the present invention. FIG. 3 is a circuit diagram schematically illustrating a voltage level shifter according to yet another preferred embodiment of the present invention. FIG. 4 is a circuit diagram schematically illustrating a conventional voltage level shifter. FIG. 5 is a waveform diagram schematically illustrating the simplified input and output voltages of the voltage level shifter of FIG. 1. FIG. 6 is a waveform diagram schematically illustrating the input and output voltages of the voltage level shifter of FIG. 1. FIG. 7 is a waveform diagram schematically illustrating the input and output voltages of the voltage level shifter of FIG. 2. FIG. 8 is a waveform diagram schematically illustrating the input and output voltages of the voltage level shifter of FIG. 3. FIG. 9 is a waveform diagram schematically illustrating the relationships between the input voltages and currents of the transistors of a conventional voltage level shifter and a voltage level shifter according to one preferred embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. FIG. 1 is a circuit diagram schematically illustrating a voltage level shifter according to one preferred embodiment of the present invention. Referring to FIG. 1, an inverter includes, for example but not limited to, a PMOS transistor 101 and a NMOS transistor 111. The PMOS transistor 101 and the NMOS transistor 111 need to be activated at different times in order to break the current paths. FIG. 5 is a waveform diagram schematically illustrating the simplified input and output voltages of the voltage level shifter of FIG. 1. Referring to FIG. 5, the transistor 101 should be turned off before the transistor 111 is turned on when an input VIN (e.g., a clock TTL voltage signal) changes from low to high level. Thus, a control signal VA is input to the voltage level shifter,—in which a timing of the control signal VA is prior to the input VIN by a time period Tdis. The control signal VA, for example, can be a high voltage control signal. The state of VOUT1B prior to the Tdis is at an analog high voltage high level VDDA, and the state of VOUT1B during the period Tdis is at high impedance state. Thus, a capacitor 121 stores the original high level and an output stage of the voltage level shifter outputs an analog high voltage low level GNDA. The transistor 111 is turned on when VIN is at high level, thus the VOUT1B is pulled down to the analog high voltage low level GNDA and the output stage outputs an analog high voltage high level VDDA. Similarly, the transistor 111 should be turned off before the transistor 101 is turned on when VIN changes from high to low level. The transistor 111 remains at a high impedance state at a time period Tk before the transistor 101 is turned on. Likewise, the capacitor 121 stores the ground level of VOUT1B. Thus, VOUT1B charges up to VDDA within a short period of time when the transistor 101 is turned on, and the output stage outputs an analog high voltage low level GNDA. Therefore, the control signal VA has a direct impact on the circuit's operation. FIG. 6 is a waveform diagram schematically illustrating the input and output voltages of the voltage level shifter of FIG. 1. Referring to FIG. 1 and FIG. 6, the PMOS transistor 101 is turned on when the control signal VA is periodically inputted and the input TTL voltage level (VIN) is at high level. At this moment, VOUT1B is charged up from the analog high voltage low level GNDA to VDDA rapidly, and a wrong output is generated. FIG. 2 is a circuit diagram schematically illustrating a voltage level shifter according to another preferred embodiment of the present invention. Referring to FIG. 2, a NMOS transistor switch transistor 251 controlled by the control signal is provided for breaking the charging path. As a result, the voltage level of VOUT1B is maintained by the capacitor 221. FIG. 7 is a waveform diagram schematically illustrating the input and output voltages of the voltage level shifter of FIG. 2. Referring to FIG. 7, the voltage level of VOUT2B is maintained by the capacitor 221 when VA is changed to low voltage level. FIG. 3 is a circuit diagram schematically illustrating a voltage level shifter according to yet another preferred embodiment of the present invention. In this embodiment of the present invention, only the buffer has to be designed in a proper size (for driving the next output), other MOS transistors can be designed in any sizes for buffering the output and maintaining the signal (as the capacitor 221 shown in FIG. 2). The PMOS transistor can be a field effect transistor (FET) designed in any size, for example, as a high voltage FET, thus the uncertainty in the manufacturing process is reduced and the stability of the circuit is enhanced. FIG. 8 is a waveform diagram schematically illustrating the input and output voltages of the voltage level shifter of FIG. 3. Referring to FIG. 3 and FIG. 8, the control signal VA produces a delayed negative pulse with very narrow width Twa when a clock TTL voltage signal changes from low to high level. During this period Twa, a NMOS transistor 311 is on, and since VA is pulled down to low level, the NMOS transistor 313 and the switch transistor 351 are turned off rapidly. In addition, the PMOS transistor 301 is turned on and VOUT3B maintains the voltage level. On the other hand, another control signal VB produces a positive pulse with a pulse width of Twb (Twb is wider than Twa) during the time period Twa. During this time period Twb, PMOS transistor 303 is off, therefore a high impedance path is constructed by the PMOS transistors 303 and 305. The NMOS transistor 313 and the switch transistor 351 are turned on again when the negative pulse of VA is off. Thus, the PMOS transistor 301 is turned off, VOUT3B is pulled down to analog high voltage low level GNDA, and the state of VOUT3 is changed to high voltage high level VDDA. Thus, the PMOS transistor 305 is turned off since VOUT3 is at high voltage high level VDDA. Moreover, the PMOS transistor 303 is turned on since the PMOS transistor 305 is turned off when the positive pulse of VB is off. Similarly, a high impedance path is constructed by the PMOS transistors 303 and 305, and during this moment, VOUT3B remains at analog high voltage low level GNDA. Referring to FIG. 8, the PMOS transistor 301 is turned on when the clock TTL voltage signal remains at high level, the control signals VA and VB provide a negative pulse and a positive pulse respectively. During this moment, the PMOS transistor 313 and the switch transistor 351 are turn off and VOUT3B remains at the same voltage level. Similarly, the control signal VA produces a delayed negative pulse with very narrow width Twa when a clock TTL voltage signal changes from high to low level. During this moment, the NMOS transistor 313 and the switch transistor 351 are turned off rapidly, the PMOS transistor 301 is turned on and VOUT3B remains at analog high voltage low level GNDA. The NMOS transistor 313 and the switch transistor 351 are turned on when the negative pulse of VA is off. During this time, the PMOS transistor 301 is turned off. In addition, since the VIN is at low voltage level originally so the NMOS transistor 311 is turned off. Therefore, during a time period Td (Td=Twb−Twa), the PMOS transistor 305 is at high impedance state before the positive pulse of VB is off. The PMOS transistor 305 is provided as a junction capacitor (i.e., a parasitic capacitor) as capacitor 221 shown in FIG. 2. Thus, VOUT3 is at analog high voltage low level GNDA. The PMOS transistor 303 is turned on rapidly after the positive pulse of VB is off. Thus a conducting path is constructed by the PMOS transistors 303 and 305, and VOUT3B is at high voltage high level VDDA via the conducting path. Moreover, the NMOS transistor 313 and the switch transistor 351 are turned off when a clock TTL voltage signal remains at low level and when the control signals VA and VB provide a negative pulse and a positive pulse respectively. FIG. 8 shows input and output voltage level changes of the voltage level shifter. Referring to FIG. 8, VOUT3B remains at an analog high voltage high level VDDA during this moment. Similarly, during a time period Td (Td=Twb−Twa), the PMOS transistor 305 is at high impedance state, thus the PMOS transistor 305 is provided as a junction capacitor (i.e., a parasitic capacitor) for maintaining the analog high voltage high level VDDA. As one preferred embodiment of the present invention, the two control signals VA and VB, for example, use positive and negative pulses as the controlling signals for a voltage level shifter. A negative pulse of VA and a positive pulse of VB are provided when the input TTL voltage signal VIN changes the state, wherein a width Twa of the negative pulse of VA corresponding to a delay after the rising of VIN. Thus, a narrower pulse width Twa is desired. Furthermore, a width Twb of the positive pulse of VB should be slightly wider than Twa because the time period Td will causes a high impedance state. The slightly wider negative pulse also can prevent from the conducting path constructed by the turning on of the PMOS transistors 303, 305 and the NMOS transistors 311, 313 and 351 when the input signal VIN is at high voltage level. As another preferred embodiment of the present invention, the possible conducting paths, for example, can be constructed by the PMOS transistor 301, the NMOS transistor 313 and the switch transistor 351 during the changing of state thereof when VIN changes to high voltage level. Referring to FIG. 3, the surge of current I(313) is much smaller than the surge of current I(415) because the PMOS transistor 301 and the NMOS transistor 313 are designed to be of any size. FIG. 9 is a waveform diagram schematically illustrating the relationships between the input voltages and currents of the transistors of a conventional voltage level shifter and a voltage level shifter according to one preferred embodiment of the present invention. Similarly, referring to FIG. 9, as another preferred embodiment of the present invention, a smaller surge is generated in compared with a conventional voltage level shifter since the inverter is constructed by PMOS transistor and NMOS transistors and the time period during the negative rising edge of the input signal. Accordingly, two control signals are provided to turn on and off the PMOS transistor and NMOS transistors in the voltage level shifter of the present invention, thus the power consumption during the turning on of the PMOS transistor and NMOS transistors is reduced. Moreover, the current path between the high voltage level and the ground are also broken totally by the two control signals to reduce the power consumption of the analog circuit. It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention is generally related to a voltage level shifter. More particularly, the present invention relates to a voltage level shifter suitable for a driving circuit of a liquid crystal display (LCD), wherein the direct current (DC) path thereof may be broken for preventing the turning on of PMOS transistor and NMOS transistors simultaneously. Therefore, the DC power consumption is reduced, and the layout of the circuit and chip area are also reduced. 2. Description of the Related Art In general, an output stage of a conventional voltage level shifter constructed by metal oxide semiconductors (MOS) includes at least an inverter for buffering. The inverter usually includes a PMOS transistor and a NMOS transistor. The problem generated in the conventional design is that it is hard to control the timing of switching the status between the transistors when the voltage level is changed. It is preferable to minimize the time for turning on both the PMOS transistor and the NMOS transistors during the switching to minimize the power consumption. However, even though the ratio of the channel width to the channel length has been considered carefully and designed, the uncertainty during the manufacturing process will still generate a considerable DC power consumption. FIG. 4 is a circuit diagram schematically illustrating a conventional voltage level shifter. Referring to FIG. 4 , the conventional voltage level shifter includes a differential input for NMOS transistors 411 and 415 . The output stage of the voltage level shifter includes a PMOS transistor 403 and a NMOS transistor 413 , and the output stage is provided for an inverter 431 . The inverter 431 can be, for example, a high voltage inverter. In addition, there is another inverter 433 electrically connected to the transistors 411 and 415 . The inverter 433 usually comprises a low voltage inverter because the driving power of the inverter 433 is less than the inverter 431 . Moreover, the inverter 433 is provided for converting the input clock transistor-transistor logic (TTL) voltage signal VIN to a differential input. Referring to FIG. 9 , when the input is a clock signal and the clock TTL signal is changed from low to high, the inverter 433 inverts the input signal and outputs a signal to a gate of the transistor 411 , in which the outputted signal is delayed a little after the VIN. Therefore, there is an extremely short period of time that a gate of the PMOS transistor 405 is at analog high voltage low level GNDA when the NMOS transistor 415 is turned on and the NMOS transistor 411 is not turned off. Thus, when the PMOS transistor 405 is still on, the PMOS transistor 405 and the NMOS transistor 415 are turned on at the same time. Thus, as shown in FIG. 9 , current I( 415 ) has a surge at the beginning of each input cycle. Moreover, for generating the differential input signal pair, the PMOS transistor requires a very fast switching in order that the NMOS transistor can control the gate of the PMOS transistor within a short time. Thus, the ratio of the channel width to the channel length of the transistors is designed to achieve the desired effects described above. Typically, the NMOS transistor is designed to have a smaller impedance, i.e., with channel having a wider width and a shorter length, and the PMOS transistor is designed to have a larger impedance, i.e., with a channel having a narrower width and a longer length. Similarly, referring to FIG. 4 and FIG. 9 , when the input clock signal is changed from high to low, the NMOS transistor 415 is turned off. At this moment, the gate of the NMOS transistor 411 is not turned on due to a time delay, therefore, the transistor 411 is at a high impedance state. During this time, a gate of the PMOS transistor 401 is at low voltage level, thus the PMOS transistor 401 is still on. Therefore, another conducting path is generated by the PMOS transistor 401 when the NMOS transistor 411 is changed from low to high level, and a current I( 411 ) will generate a surge at this time. Thus, the breaking of the conducting path between the high voltage and the ground is required in order to reduce the power consumption during the turning on of both of the PMOS transistor and NMOS transistors to reduce the power consumption of the analog circuit. Furthermore, the voltage level shifter that applies to a driving circuit of a LCD occupies significant chip area. The chip area can be more compact if the ratio of the channel width to the channel length is not an issue. Therefore, a voltage level shifter that can reduce the power consumption and the chip area to lower down the cost is required. | <SOH> SUMMARY OF THE INVENTION <EOH>The present invention is to provide a voltage level shifter wherein the current path between the high voltage level and the ground are completely broken. Another objective of the present invention is to provide a voltage level shifter wherein the ratio of the channel width to the channel length of the transistors is not a major issue in the circuit design. Another objective of the present invention is to provide a voltage level shifter suitable for a driving circuit of a LCD, wherein the chip area is substantially reduced due to the repeating of some circuits. The present invention provides at least one voltage level shifter for breaking the current path and for turning on the PMOS transistor and NMOS transistors connected in serial in the circuit at different times. Thus, an input/output control sequence is required. The present invention provides many different input/output timing sequences in the embodiments that can achieve the desired results. This invention may, however, be embodied in many other different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete, To begin with, an output stage of a voltage level shifter is an inverter. When an input signal of the shifter is at low voltage level, an output signal from the output stage is also at low voltage level. A PMOS transistor should have been turned off before a NMOS transistor is turned on when the input signal is changed from low level to high level. Thus, a control signal is provided with a time period in front of the input signal. The input signal and the control signal are processed by an inverter, thus the PMOS transistor is at a high impedance during the rising of the control signal and the rising of the input signal. During this time, the output stage outputs a low voltage signal and a capacitor stores the original high voltage level of the output stage. The NMOS transistor is turned on when the input signal is changed from low to high level. The NMOS transistor pulls down the voltage stored in the capacitor to low voltage level. At the same time, an inverter pulls up an output terminal to high voltage level. Similarly, the NMOS transistor should have been turned off before the PMOS transistor turns on when the input signal changes from high to low level. In other words, the NMOS transistor should also be at high impedance state for another time period before the PMOS transistor is turned on. The capacitor is maintained at the ground level and then the PMOS transistor is turned on, thus a high voltage level is achieved within a short time. During this time, the output stage outputs a low voltage signal. Therefore, the control signal has a direct impact on the operation of the circuit. However, the PMOS transistor is turned on when the control signal is periodic and the input signal is at high voltage level. The capacitor is charged up from the ground to high voltage level within a short period of time, and thus an error output is generated. Thus, a switch transistor is connected in between the NMOS transistor and the capacitor for producing another control signal to break the charging path. As a result, the voltage level of the capacitor is maintained. The capacitor keeps to perform the same operation as previously described when the control signal changes back to low voltage level again. As a simplified version of the present invention, an AND gate of the input terminal, the PMOS transistor and the NMOS transistor can be three transistors connected in series. The sequence of the connection from high voltage level to the ground includes a first PMOS transistor, a first NMOS transistor and a second NMOS transistor. Wherein, a gate of the second NMOS transistor is electrically connected to the input signal. A gate of the first PMOS transistor and a gate of the first NMOS transistor are electrically connected to a first control signal. Moreover, the transistor in a buffer (for example, an inverter described above) has to be in a proper size in order to drive the next output. Moreover, the capacitor, for example, can be comprised of a second PMOS transistor and a third PMOS transistor connected in series. Wherein, the second PMOS transistor is electrically connected to a high voltage level and a gate of the second PMOS transistor is electrically connected to a second control signal. The third PMOS transistor is electrically connected to the buffer (for example, an inverter), and thus a latch circuit is provided. Furthermore, the switch transistor, for example, can be comprised of a third NMOS transistor. The PMOS transistors can be designed in any size, for example, be high voltage transistors. Thus, the uncertainty generated from the manufacturing process is reduced and the stability of the circuit is enhanced. The first control signal produces a negative pulse with very narrow width when the inputted clock signal changes from low to high voltage level. During this time, the second NMOS transistor is turned on and the first control signal changes to low voltage level. As a result, the first and third NMOS transistors are turned off, the first PMOS transistor is turned on and the capacitor keeps the same voltage level. At the same time, the second control signal inputs a positive pulse with a wider pulse width than the pulse width of the first control signal. During this time, the second PMOS transistor is turned off. Thus, a high impedance path is formed between the second and third PMOS transistors. Moreover, the first and third NMOS transistors are turned on and the first PMOS transistor is turned off when the negative pulse from the first control signal ends. At the same time, the capacitor discharges to low voltage level and the output signal changes to high voltage level. The third PMOS transistor turns off due to high voltage level in the output. Although the second PMOS transistor conducts when the positive pulse of the second control signal is off, but because the third PMOS transistor remains in the off state, a high impedance path is formed between the second and third PMOS transistors and the capacitor maintains the low voltage level. In the case when the input clock signal is at high voltage level and the first control signal and the second control signal provide a negative pulse and a positive pulse respectively, the first PMOS transistor is turned on. During this time, the first and third NMOS transistors are turned off and the voltage level of the capacitor remains the same as previous. Similarly, the first control signal produces a negative pulse with very narrow width when input a clock signal that changes from high to low voltage level. During this time, the second NMOS transistor turns on and the first control signal changes to low voltage level. As a result, the first and third NMOS transistors are turned off, the first PMOS transistor is turned on and the capacitor maintains the same voltage level. Moreover, the first and third NMOS transistors are turned on and the first PMOS transistor is turned off when the negative pulse from the first control signal ends. The second NMOS transistor is turned off because the original input signal is at low voltage level. Hence, the second PMOS transistor temporarily acts as a parasitic capacitor before the positive pulse from the second control signal ends. During this time, the second PMOS transistor is at high impedance state and the output signal is at low voltage level. The second PMOS transistor conducts after the positive pulse from the second control signal ends. Thus, the second and third PMOS transistors form a conducting path. At this time, the capacitor is at high voltage level. Similarly, in the case when the input clock signal is at low voltage level and the first control signal and the second control signal provide a negative pulse and a positive pulse respectively, the first PMOS transistor is turned on. During this time, the first and third NMOS transistors are turned off and the voltage level of the capacitor remains the same as previous. Immediately after that, the third PMOS transistor temporarily (with high impedance) acts as a parasitic capacitor for a short period of time (Td). Moreover, both of the first and second control signals (for example, high voltage control signals) use positive/negative pulses as the controlling signals to control a voltage level shifter. The first control signal and second control signal provide a negative pulse and a positive pulse respectively when the input status is changed. The width of a negative pulse should be slightly wider than the width of a positive pulse because the time periods between the positive pulse and the negative pulse inevitably results in high impedance. The slightly wider negative pulse also prevents damages resulted from the second and third PMOS transistors being conducted to the first, second and third NMOS transistors when the input signal is at high voltage level. Moreover, the first PMOS transistor, the first and third NMOS transistors form conducting paths when the input signal is changed to a high voltage level. Furthermore, the first PMOS transistor and the first NMOS transistor produce smaller surges compared to that of the prior art since the first PMOS transistor/NMOS transistor can be designed in many ways. Similarly, the buffer of the output stage (the buffer comprises an inverter made from PMOS transistor/NMOS transistor) also results in a smaller surge (compared to prior art) when the input clock signal is changed from high to low voltage level. Accordingly, in the voltage level shifter of the present invention, two control signals are provided to turn on and off the PMOS transistor and NMOS transistors, thus the power consumption during the turning on of the PMOS transistor and NMOS transistors is reduced. Moreover, the current path between the high voltage level and the ground are also broken totally by the two control signals reducing the power consumption of the analog circuit. It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. | 20040211 | 20060704 | 20050421 | 83453.0 | 0 | ENGLUND, TERRY LEE | VOLTAGE LEVEL SHIFTER | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,777,698 | ACCEPTED | Polyester resin composition for use in a coating composition and method of preparing the same | A polyester polycarbamate resin composition for use in coating compositions to produce films having improved scratch and mar characteristics. The resin composition is the reaction product of a first compound having a plurality of hydroxyl groups with a carbamate compound reactive with the hydroxyl groups of the first compound and added in an amount sufficient to form a carbamated intermediary. The carbamated intermediary has at least one primary carbamate group available for cross-linking and has unreacted hydroxyl groups. Then, a silyl compound having a terminal isocyanate group is reacted with the unreacted hydroxyl groups of the carbamated intermediary. The silyl compound also has silylalkoxy groups available for secondary cross-linking. The present invention is also directed to a method of preparing the resin composition. | 1. A polyester resin composition having increased cross-linking capability for use in a coating composition, said resin composition comprising the reaction product of: a first compound having a plurality of hydroxyl groups; a carbamate compound reactive with said hydroxyl groups of said first compound and added in an amount sufficient to form a carbamated intermediary having at least one primary carbamate group available for cross-linking and having unreacted hydroxyl groups; and a silyl compound having a terminal isocyanate group for reacting with said unreacted hydroxyl groups of said carbamated intermediary and having silylalkoxy groups available for secondary cross-linking. 2. A polyester resin composition as set forth in claim 1 wherein said silyl compound is further defined as an isocyanatoalkylalkoxysilane. 3. A polyester resin composition as set forth in claim 1 wherein said first compound is selected from the group consisting of erythritol, pentaerythritol, dipentaerythritol, glycerol, trimethylolethane, trimethylolpropane, dulcitol, threitol, and mixtures thereof. 4. A polyester resin composition as set forth in claim 1 wherein said carbamate compound is further defined as an alkyl carbamate having 1 to 20 carbon atoms in the alkyl chain. 5. A polyester resin composition as set forth in claim 1 wherein said silyl compound is selected from the group consisting of isocyanatopropyltrimethoxysilane, isocyanatopropylmethyldimethoxysilane, isocyanatopropylmethyldiethoxysilane, iso-cyanatopropyltriethoxysilane, isocyanatoneohexyltrimethoxysilane, isocyanate-neohexyldimethoxysilane, isocyanatoneohexydiethoxysilane, isocyanatoneo-hexyltriethoxysilane, isocyanatoisoamyltrimethoxysilane, isocyanatoisoamyl-dimethoxysilane, isocyanateisoamylmethyldiethoxysilane, isocyanatoisoamyltri-ethoxysilane, and mixtures thereof. 6. A polyester resin composition as set forth in claim 1 having a polydispersity of from about 1 to about 2. 7. A polyester resin composition as set forth in claim 1 having a number-average molecular weight of less than 4000. 8. A polyester resin composition as set forth in claim 1 having a non-volatile content of from 50 to 90. 9. A polyester resin composition as set forth in claim 1 wherein said first compound is present in an amount of from 1 to 50 parts by weight based on 100 parts by weight of said polyester resin composition. 10. A polyester resin composition as set forth in claim 1 wherein said amount of said carbamate compound is from 5 to 65 parts by weight based on 100 parts by weight of said polyester resin composition. 11. A polyester resin composition as set forth in claim 1 wherein said silyl compound is present in an amount of from 1 to 70 parts by weight based on 100 parts by weight of said polyester resin composition. 12. A polyester resin composition as set forth in claim 1 further comprising a carboxylic acid anhydride reactive with said hydroxyl groups of said first compound. 13. A polyester resin composition as set forth in claim 12 further comprising a second compound having at least one epoxy group reactive with said carboxylic acid anhydride. 14. A polyester resin composition having increased cross-linking capability for use in a coating composition, said resin composition comprising the reaction product of: a first compound having a plurality of hydroxyl groups; a carboxylic acid anhydride; a second compound having at least one epoxy group; a carbamate compound; and a silyl compound having a terminal group reactive with hydroxyl groups and having silylalkoxy groups. 15. A polyester resin composition as set forth in claim 14 wherein said first compound comprises pentaerythritol. 16. A polyester resin composition as set forth in claim 15 wherein said carboxylic acid anhydride comprises hexahydrophthalic anhydride. 17. A polyester resin composition as set forth in claim 16 wherein said second compound comprises glycidylneodecanoate. 18. A polyester resin composition as set forth in claim 17 wherein said carbamate compound comprises methyl carbamate. 19. A polyester resin composition as set forth in claim 18 wherein said silyl compound comprises an isocyanatoalkylalkoxysilane. 20. A polyester resin composition as set forth in claim 14 wherein said first compound is selected from the group consisting of erythritol, pentaerythritol, dipentaerythritol, glycerol, trimethylolethane, trimethylolpropane, dulcitol, threitol, and mixtures thereof. 21. A polyester resin composition as set forth in claim 14 wherein said second compound is selected from the group consisting of glycidylneodecanoate, dodecyl oxide, tetradecyl oxide, octadecyl oxide, and cyclohexene oxide, and mixtures thereof. 22. A polyester resin composition as set forth in claim 14 wherein said carboxylic acid anhydride is selected from the group consisting of maleic anhydride, hexahydrophthalic anhydride, methyl-hexahydrophthalic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, succinic anhydride, dodecenylsuccinic anhydride, trimellitic anhydride, and mixtures thereof. 23. A polyester resin composition as set forth in claim 14 wherein said carbamate compound is further defined as an alkyl carbamate having 1 to 20 carbon atoms in the alkyl chain. 24. A polyester resin composition as set forth in claim 14 wherein said carbamate compound is selected from the group consisting of methyl carbamate, ethyl carbamate, and mixtures thereof. 25. A polyester resin composition as set forth in claim 14 wherein said silyl compound is selected from the group consisting of isocyanatopropyltrimethoxysilane, iso-cyanatepropylmethyldimethoxysilane, isocyanatopropylmethyldiethoxysilane, isocyanate-propyltriethoxysilane, isocyanatoneohexyltrimethoxysilane, isocyanateneo-hexyldimethoxysilane, isocyanatoneohexydiethoxysilane, isocyanatoneohexyl-triethoxysilane, isocyanateisoamyltrimethoxysilane, isocyanatoisoamyldimethoxysilane, isocyanatoisoamylmethyldiethoxysilane, isocyanatoisoamyltriethoxysilane, and mixtures thereof. 26. A polyester resin composition as set forth in claim 14 having a polydispersity of from about 1 to about 2. 27. A polyester resin composition as set forth in claim 14 having a number average molecular weight of less than 4000. 28. A polyester resin composition as set forth in claim 14 having a non-volatile content of from 50 to 90. 29. A polyester resin composition as set forth in claim 14 wherein said first compound is present in an amount from 1 to 50 parts by weight based on 100 parts by weight of said polyester resin composition. 30. A polyester resin composition as set forth in claim 14 wherein said carboxylic acid anhydride is present in an amount from 10 to 40 parts by weight based on 100 parts by weight of said polyester resin composition. 31. A polyester resin composition as set forth in claim 14 wherein said second compound is present in an amount from 20 to 70 parts by weight based on 100 parts by weight of said polyester resin composition. 32. A polyester resin composition as set forth in claim 14 wherein said amount of said carbamate compound is from 5 to 65 parts by weight based on 100 parts by weight of said polyester resin composition. 33. A polyester resin composition as set forth in claim 14 wherein said silyl compound is added in an amount of from 1 to 70 parts by weight based on 100 parts by weight of said polyester resin composition. 34. A method of preparing a polyester resin composition for use in a coating composition, said method comprising the steps of: (A) providing a branched compound having a plurality of hydroxyl groups; (B) reacting hydroxyl groups with a carbamate compound to form a carbamated intermediary having at least one primary carbamate group available for cross-linking and having unreacted hydroxyl groups; (C) reacting the unreacted hydroxyl groups of the carbamated intermediary with a silyl compound having a terminal group reactive with said unreacted hydroxyl groups and having silylalkoxy groups, each being available for cross-linking, to form the resin composition. 35. A method as set forth in claim 34 wherein the step of (A) providing the branched compound is further defined as providing a first compound selected from the group consisting of erythritol, pentaerythritol, dipentaerythritol, glycerol, trimethylolethane, trimethylolpropane, dulcitol, threitol, and mixtures thereof. 36. A method as set forth in claim 34 further comprising the step of reacting the hydroxyl groups of the branched compound with a carboxylic acid anhydride selected from the group consisting of maleic anhydride, hexahydrophthalic anhydride, methyl-hexahydrophthalic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, succinic anhydride, dodecenylsuccinic anhydride, trimellitic anhydride, and mixtures thereof, to form a first intermediate compound having the plurality of carboxylic acid groups prior to reacting with the carbamate compound. 37. A method as set forth in claim 36 further comprising the step of reacting at least one of the carboxylic acid groups of the first intermediate compound with a second compound selected from the group consisting of glycidylneodecanoate, dodecyl oxide, tetradecyl oxide, octadecyl oxide, and cyclohexene oxide, and mixtures thereof, to form the second intermediate compound having the at least one hydroxyl group prior to reacting with the carbamate compound. 38. A method as set forth in claim 37 further comprising the the step of reacting the at least one hydroxyl group of the second intermediate compound with an alkyl carbamate having from 1 to 20 carbon atoms in the alkyl chain, to prepare the resin composition of step (B). 39. A method as set forth in claim 38 wherein the step of (C) reacting any remaining hydroxyl groups of the carbamated intermediary with the silyl compound is further defined as reacting any remaining hydroxyl groups of the carbamated intermediary with at least one of isocyanatopropyltrimethoxysilane, isocyanatopropyl-methyldimethoxysilane, isocyanatopropylmethyldiethoxysilane, isocyanatopropyl-triethoxysilane, isocyanatoneohexyltrimethoxysilane, isocyanatoneohexyldimethoxy-silane, isocyanatoneohexydiethoxysilane, isocyanatoneohexyltriethoxysilane, isocyanate-isoamyltrimethoxysilane, isocyanatoisoamyldimethoxysilane, isocyanatoisoamylmethyl-diethoxysilane, and isocyanatoisoamyltriethoxysilane. 40. A method as set forth in claim 34 further including the step of continuing the reaction of step (C) until less than 5% of isocyanate groups remain in the resin composition. 41. A method as set forth in claim 40 further including the step of removing excess carbamate compound that has not reacted with the hydroxyl groups. 42. A method as set forth in claim 34 wherein the steps of (A) through (C) are conducted at a temperature between 50° C. and 200° C. | FIELD OF THE INVENTION The subject invention generally relates to a polyester resin composition utilized in coating compositions. More specifically, the subject invention relates to a polyester resin composition having increased cross-linking capability for use in a clear coat and a method of preparing the polyester resin composition. BACKGROUND OF THE INVENTION Various resin compositions are known for use in coating compositions that include silyl compounds and carbamate compounds. Typically, the resin compositions include a first compound having a plurality of hydroxyl groups, such as a diol or a polyester or polyether polyol. Examples of such compositions are disclosed in U.S. Pat. Nos. 6,602,964; 6,375,789; and 6,319,311. These patents disclose a resin composition formed from a silane carbamate compound. To form the silane carbamate compound, a silyl compound is reacted with diol, which forms the carbamate group with an isocyanate group of the silyl compound. However, for this reaction to proceed, the conditions must be precisely controlled and certain catalysts are used to ensure the formation of the silane carbamate compound. None of these resin compositions include a first compound having carbamate functionality and silyl functionality separate from the carbamate functionality, since the silyl compound and the carbamate compound are reacted to form the silane carbamate compound, prior to reaction with the first compound. Therefore, there are no secondary groups available for supplemental cross-linking. Another example of a resin composition is disclosed in U.S. Pat. No. 6,451,930. The '930 patent discloses a resin composition that includes two distinct components. The first component is as a polyester polymer having a carbamate group and the second component is an oxyalkylsilyl monomer containing a silyl group. The first component does not include primary carbamate groups that are available for cross-linking, nor does the second component include terminal isocyanate groups available for reacting with the unreacted hydroxyl groups of the first component. Therefore, like the resin composition described above, this resin composition does not have the capability of increased cross-linking. Accordingly, it would be advantageous to provide a resin composition that has increased cross-linking capability for use in a coating composition. The increased cross-linking capability of the coating composition would allow for linking with various cross-linkers, which when applied to a substrate produces a film having improved physical properties. SUMMARY OF THE INVENTION A polyester resin composition is disclosed. The resin composition of the subject invention is utilized in a coating composition and exhibits improved scratch and mar characteristics. This resin composition is the reaction product of a first compound, a carbamate compound, and a silyl compound. The first compound has a plurality of hydroxyl groups and the carbamate compound is reactive with the hydroxyl groups of the first compound. Further, the carbamate compound is added in an amount sufficient to form a carbamated intermediary. The carbamated intermediary has at least one primary carbamate group available for cross-linking and has unreacted hydroxyl groups. The silyl compound, which has a terminal isocyanate group, reacts with the unreacted hydroxyl groups of the carbamated intermediary to form the resin composition. The silyl compound also includes silylalkoxy groups which, after the terminal isocyanate group has reacted with the unreacted hydroxyl groups, are available for secondary cross-linking. A method of preparing the polyester resin composition is also disclosed. According to this method, the hydroxyl groups of the first compound are reacted with the carbamate compound to form the carbamated intermediary. The carbamated intermediary has unreacted hydroxyl groups which are further reacted with the silyl compound to form the resin composition having available carbamate groups for cross-linking and available silylalkoxy groups for secondary cross-linking. The general object of the subject invention is to develop a polyester resin composition for use in a coating composition to produce films that have improved scratch and mar characteristics. Without intending to be bound by theory, it is believed that the improved results are obtained because the resin composition has an increased cross-linking capability due to the carbamate groups from the carbamated polyester and due to the silylalkoxy groups from the silyl compound. The primary carbamate group is available for cross-linking and the silylalkoxy groups are available for secondary cross-linking. It is this cross-linking which provides the improved scratch and mar characteristics in the films of the coating composition. Further, the silyl compound reduces the viscosity and surface tension of the resin composition, while also using less solvent to reduce the viscosity for application of the coating composition. DETAILED DESCRIPTION OF THE INVENTION The general object of the subject invention is to develop a polyester resin composition for use in a coating composition. The resin composition has increased cross-linking capability, which when reacted with a cross-linker and applied to a substrate as a film, has improved scratch and mar characteristics. Without intending to be bound by theory, it is believed that the improved results are obtained when the resin composition has an increased cross-linking capability. In the subject invention, terminal carbamate groups are available for cross-linking and silylalkoxy groups are available for secondary cross-linking. It is this cross-linking which provides the improved scratch and mar characteristics of the film. The resin composition of the subject invention, a polyester polycarbamate, is utilized in coating compositions and results in improved scratch and mar characteristics. The polyester resin composition of the present invention, also referred to in the art as a star polyester polymer, is used in a coating composition, preferably in conjunction with a suitable cross-linking agent, to produce a film for coating a substrate, such as the body panels of a vehicle and the like. The resin composition includes a branched organic structure having various functionalities including, but not limited to, branched hydrocarbon functionality, hydroxyl functionality, carboxylate functionality, carbamate functionality, and ester functionality. In a first embodiment, the resin composition is generally the reaction product of a first compound having a plurality of hydroxyl groups, a primary carbamate compound, and a silyl compound having a terminal group reactive with hydroxyl groups and also having silylalkoxy groups. In a second embodiment, the resin composition is more specifically the reaction product of the first compound having the plurality of hydroxyl groups, a carboxylic acid anhydride, a second compound having at least one epoxy group, the carbamate compound, and the silyl compound having the terminal group reactive with hydroxyl groups and having silylalkoxy groups. In both embodiments, the first compound is a branched compound having a plurality of hydroxyl groups, however, the first compound may remain unreacted or reacted prior to carbamation, as will be described more below. In the first embodiment, the method of preparing the resin composition includes the steps of providing the branched compound having the plurality of hydroxyl groups and reacting the hydroxyl groups of the branched compound with the carbamate compound to form a carbamated intermediary. The carbamated intermediary has at least one primary carbamate group that is available for cross-linking and has unreacted hydroxyl groups. The primary carbamate group results from the reaction of the carbamate compound with the first compound. The unreacted hydroxyl group results from the plurality of hydroxyl groups of the first compound. The unreacted hydroxyl groups are then reacted with the terminal group of the silyl compound, which is preferably a terminal isocyanate group. This allows the silylalkoxy groups of the silyl compound to be available for secondary cross-linking. The method steps of the first embodiment are preferably conducted at temperatures between 50° C. and 200° C., more preferably between 100° C. and 175° C. This method will be described in further detail below. In the second embodiment, the method of preparing the resin composition includes the steps of providing the branched compound having the plurality of hydroxyl groups, reacting the hydroxyl groups of the branched compound with the carboxylic acid anhydride to form a first intermediate compound having a plurality of carboxylic acid groups and may be, unreacted hydroxyl groups, and then reacting at least one of the carboxylic acid groups of the first intermediate compound with the epoxy group of the second compound to form a second intermediate compound having at least one hydroxyl group. The at least one hydroxyl group of the second intermediate compound is then reacted with the carbamate compound, which results in the primary carbamate groups, which are for cross-linking. Next, all of the unreacted hydroxyl groups of this carbamated intermediate are reacted with the terminal isocyanate group of the silyl compound to prepare the resin composition. The silyl compound includes silylalkoxy groups for secondary cross-linking. Like the first embodiment, the method steps for the second embodiment are preferably conducted at temperatures between 50° C. and 200° C., more preferably between 100° C. and 175° C. This method will be described in further detail below. To prepare the polyester resin composition, the first compound is selected to maximize the number of hydroxyl groups, i.e., the hydroxyl functionality, in the first compound while establishing a foundation for the branched organic structure of the resin composition. As such, the first compound may alternatively be described as a branched compound having a plurality of hydroxyl groups. The hydroxyl groups of the first compound can be primary, secondary, and tertiary hydroxyl groups. Preferably, the first compound is present in the resin composition in an amount from 1 to 50, more preferably from 10 to 30, parts by weight based on 100 parts by weight of the resin composition. The first compound is more specifically selected from the group consisting of erythritol, pentaerythritol, dipentaerythritol, glycerol, trimethylolethane, trimethylolpropane, dulcitol, threitol, and mixtures thereof. As understood by those skilled in the art, trimethylolethane and trimethylolpropane each provide three hydroxyl groups, erythritol, pentaerythritol and threitol each provide four hydroxyl groups, and dipentaerythritol and dulcitol each provide six hydroxyl groups. In the preferred embodiment of the subject invention, the first compound comprises pentaerythritol. For descriptive purposes, a chemical representation of pentaerythritol is disclosed below. As shown above, pentaerythritol is a compound having a central carbon atom and four peripheral carbon atoms each providing a hydroxyl group for a total of four hydroxyl groups. In view of the above characteristics of the first compound, other equivalent compounds include, but are not limited to, ethylene glycol and propylene glycol, which each provide two hydroxyl groups, and glycerol, which provides three hydroxyl groups. Other alcohols, sugars, and acids providing a plurality of hydroxyl groups are also suitable as the first compound. Next, in the first embodiment, the carbamate compound is added to the first compound. The carbamate compound is further defined as an alkyl carbamate having 1 to 20 carbon atoms in the alkyl chain. For example, the carbamate compound may be generically defined as where R is an alkyl chain having from 1 to 20 carbon atoms. Preferably, the carbamate compound is selected from the group consisting of methyl carbamate, ethyl carbamate, and mixtures thereof. The most preferred carbamate compound comprises methyl carbamate [CH3OC(O)NH2]. Other carbamate compounds include, but are not limited to, butyl carbamate, propylene glycol monocarbamate, and the like. The carbamate compound is present in the resin composition in an amount from 5 to 65, preferably from 20 to 60, parts by weight based on 100 parts by weight of the resin composition. The carbamate compound is added in an amount sufficient to form a carbamated intermediary having unreacted hydroxyl groups. This trans-carbamation is effected by use of a tin catalyst like dibutyltin dioxide (DBTO) and removing the alcohol byproduct that is formed. It is preferred that the first compound is carbamated to at least 75%, i.e., that three out of the four available hydroxyl groups have been reacted and therefore the carbamated intermediary has at least one unreacted hydroxyl groups. It is to be appreciated that in a mixture, there will be certain molecules that may have achieved 100% carbamation, while others will only be at 25% or less. Therefore, the 75% carbamation refers to the mixture, so long as there remain unreacted hydroxyl groups. Those skilled in the art recognize that the amount of carbamation can be determined by either titration to determine the hydroxyl number or by monitoring the amount of methanol by-product produced from the reaction. A theoretical amount of methanol by-product can be calculated for 75% carbamation and once that amount is reached, the reaction will have reached the desired carbamation. As indicated above, the number of hydroxyl groups in the first compound functions as a foundation for the branched organic structure of the resin composition. In the preferred embodiment, the molar ratio of the carbamate compound, methyl carbamate, to the first compound, pentaerythritol, is 3:1. If the first compound is dipentaerythritol having six hydroxyl groups, then preferably five moles of the carbamate compound are utilized to prepare the completed resin composition. Of course, structures resulting from lower equivalents of the carbamate compound are not to be excluded, so long as there are plurality of carbamate groups and at least one hydroxyl group available for subsequent reaction with the silyl compound. A chemical representation of the carbamated intermediary of the first embodiment, wherein the first compound is pentaerythritol and the carbamate compound is methyl carbamate, is disclosed below. The carbamated intermediary is then reacted with a silyl compound having the terminal group. The terminal group is preferably an isocyanate group, however, other groups may be used that are reactive with hydroxyl groups. The terminal group should be more reactive than the silylalkoxy groups with the hydroxyl groups to ensure that the silylalkoxy groups are intact at the end of the reaction. Preferably, the silyl compound is an isocyanatoalkylalkoxysilane and is more preferably selected from the group consisting of isocyanatopropyltrimethoxysilane, isocyanatopropylmethyldimethoxysilane, isocyanatopropylmethyldiethoxysilane, iso-cyanatepropyltriethoxysilane, isocyanatoneohexyltrimethoxysilane, isocyanate-neohexyldimethoxysilane, isocyanatoneohexydiethoxysilane, isocyanatoneo-hexyltriethoxysilane, isocyanatoisoamyltrimethoxysilane, isocyanatoisoamyl-dimethoxysilane, isocyanatoisoamylmethyldiethoxysilane, isocyanatoisoamyltri-ethoxysilane, and mixtures thereof. One example of the silyl compound is commercially available from Crompton Corp. as SILQUEST® A-Link 25 or SILQUEST® A-Link 35. It is believed that the terminal isocyanate component of the silyl compound reacts with the unreacted hydroxyl groups of the carbamated intermediary, because the hydroxyl groups are much more reactive than the carbamate groups toward the isocyanate. However, it is to be appreciated that in the mixture, and under particular reaction circumstances, while not preferred, the isocyanate groups may react with the carbamate groups. The reaction of the silylalkoxy groups with the hydroxyl group may occur but the experimental conditions were chosen such that the isocyanate group will react with the hydroxyl groups more readily over that of silylalkoxy reaction with the hydroxyls. The silyl compound also reduces the viscosity and surface tension of the resin composition, while also allowing for a higher solids content to be obtained for the resin composition. Reduced viscosity of the resin composition means that less solvent is required to lower an application viscosity of a coating composition that incorporates the resin composition and this is, therefore, more environmentally friendly. The silyl compound is present in the resin composition in an amount from 1 to 70, preferably from 15 to 50, parts by weight based on 100 parts by weight of the resin composition. A chemical representation of the resin composition of the first embodiment is disclosed below where the silyl compound is isocyanatopropyltrimethoxysilane. In the second embodiment, the first compound is first reacted with the carboxylic acid anhydride prior to adding the carbamate compound. The carboxylic acid anhydride may be either an aromatic or non-aromatic cyclic anhydride. The carboxylic acid anhydride is preferably selected from, but not limited to, the group consisting of maleic anhydride, hexahydrophthalic anhydride, methyl-hexahydrophthalic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, succinic anhydride, dodecenylsuccinic anhydride, trimellitic anhydride, and mixtures thereof. In the preferred embodiment of the subject invention, the carboxylic acid anhydride comprises hexahydrophthalic anhydride. For descriptive purposes, a chemical representation of hexahydrophthalic anhydride is disclosed below. As shown above, the hexahydrophthalic anhydride provides an acid functionality whereby one carboxylic acid group can be formed into the intermediate compound per mole of the carboxylic acid anhydride introduced. The carboxylic acid anhydride is present in the resin composition in an amount from 10 to 40, preferably from 23 to 37, parts by weight based on 100 parts by weight of the resin composition. More specifically, in the preferred embodiment, the molar ratio of the carboxylic acid anhydride, hexahydrophthalic anhydride, that is reacted with the first compound, pentaerythritol, is 3:1. That is, three moles of hexahydrophthalic anhydride are reacted with one mole of pentaerythritol to form the first intermediate compound. For descriptive purposes, a chemical representation of the first intermediate compound formed by the reaction of one mole pentaerythritol and three moles of hexahydrophthalic anhydride according to the second embodiment is disclosed below. As shown above, the first intermediate compound that is formed with the reactants of the preferred embodiment is a tricarboxylic acid compound, i.e., a compound including three carboxylic acid groups or an acid functionality of three. These three carboxylic acid groups of the first intermediate compound are formed when the anhydride rings of the three moles of hexahydrophthalic anhydride open forming ester linkages with the pentaerythritol, and the hydrogen atoms from the three hydroxyl groups of the pentaerythritol react with the oxygen atoms originally from the anhydride rings of the three moles of hexahydrophthalic anhydride thereby forming the tricarboxylic acid intermediate compound according to the preferred embodiment. As stated above, the intermediate compound of the preferred embodiment has an acid functionality of three. Of course, it is to be understood that the acid functionality can decrease or increase depending upon the selection of the particular first compound and of the particular carboxylic acid anhydride, and upon the equivalent weight ratios between the first compound and the carboxylic anhydride. It is preferred to have unreacted hydroxyl groups remaining from the first compound for reacting with the silyl compound to increase the cross-linking capability of the compound and reduce the equivalent weight of the resin. The chemical representation of the first intermediate compound disclosed above is merely illustrative of the subject invention. The intermediate compound disclosed above has a four-branch organic structure originally derived from the organic structure of the pentaerythritol. It is to be understood that if an alternative first compound is selected, such as dipentaerythritol which, as discussed above, provides six hydroxyl groups, then the intermediate compound would have a six-branch organic structure derived from the structure of the dipentaerythritol. Of course, five moles of hexahydrophthalic anhydride then would be selected to react with five of the six hydroxyl groups of the dipentaerythritol. Continuing with the preparation of the resin composition according to the second embodiment, at least one of the carboxylic acid groups of the first intermediate compound is reacted with the second compound to form the second intermediate compound having the at least one hydroxyl group. More specifically, it is the epoxy group of the second compound that reacts with at least one of the carboxylic acid groups of the first intermediate compound to form the second intermediate compound having the at least one hydroxyl group. Preferably, all of the carboxylic acid groups of the first intermediate compound are reacted with the second compound such that the second intermediate compound is formed with a plurality of hydroxyl groups. The second compound is selected to include at least one epoxy group, and is present in the resin composition in an amount from 20 to 70, preferably from 30 to 60, parts by weight based on 100 parts by weight of the resin composition. The second compound is further selected to include from 6 to 20, preferably from 10 to 15, carbon atoms. As such, the second compound is selected from the group consisting of glycidylneodecanoate, dodecyl oxide, tetradecyl oxide, octadecyl oxide, and cyclohexene oxide, and mixtures thereof. In view of the above characteristics of the second compound, other equivalent compounds include, but are not limited to, epoxy-containing aromatic hydrocarbons such as bisphenol A monoglycidyl ether. In the preferred embodiment of the subject invention, the second compound comprises glycidylneodecanoate. As is known in the art, glycidylneodecanoate is commercially available from Miller-Stephenson Chemical Company, Inc. under its CARDURA® product line, as CARDURA E 10P. For descriptive purposes, a chemical representation of glycidylneodecanoate is disclosed below. As shown above, glycidylneodecanoate includes one epoxy group. Preferably, three moles of glycidylneodecanoate are reacted with the three carboxylic acid groups of the first intermediate compound such that one epoxy group reacts with each carboxylic acid group. As described above, it is the epoxy group of the second compound that reacts with at least one of the carboxylic acid groups of the first intermediate compound. More specifically, the epoxy ring of the glycidylneodecanoate opens such that one of the two carbon atoms, originally in the epoxy ring of the glycidylneodecanoate, reacts and bonds with an oxygen atom from one of the hydroxyls of the carboxylic acid groups of the first intermediate compound. It is to be understood by those skilled in the art that in the reaction, the epoxy ring can open in one of two manners such that either one of the carbon atoms of the epoxy ring reacts and bonds with the oxygen atom from the hydroxyl of the carboxylic acid group. The resultant second intermediate compound includes either a primary hydroxyl or a secondary hydroxyl. For simplicity, only the second intermediate compound with primary hydroxyl groups is disclosed, but it is to be appreciated that one skilled in the art would recognize the second intermediate compound with secondary hydroxyl groups. Next, in the second embodiment, the hydroxyl groups of the second intermediate compound are reacted with the carbamate compound in amounts sufficient to carbamate the second intermediate compound, as described above. Those skilled in the art will appreciate that in the mixture some of the unreacted hydroxyls may react with the carbamate compound. A chemical representation of the carbamated intermediary of the second embodiment is disclosed below, wherein only the primary hydroxyls from the reaction of carboxylic acids with the epoxide are transcrabamated. However, those skilled in the art will recognize that one cannot distinguish between these and the unsubstituted primary hydroxyl from the starting first compound. Also, some of the secondary hydroxyls present will also be transcarbamated, even though kinetically these are expected to be slower. As shown above in the carbamated intermediary, the carbamate compound, methyl carbamate, has reacted with the primary hydroxyls of the second intermediate compound that result from the particular manner of epoxy ring opening of the glycidylneodecanoate. As such, primary carbamate groups are present. Of course, in terms of the second embodiment, during the three moles of methyl carbamate react with the hydroxyl groups of the second intermediate compound (catalyzed by Tin compounds) to prepare the resin composition, three moles of methanol are produced as a side product. The number of moles of alcohol that are produced as a side product vary depending on the number of moles of the carbamate compound, preferably the methyl carbamate, that are reacted with the second intermediate compound. It is to be appreciated that the carbamate compound can also react with the secondary hydroxyls of the second intermediate compound that result from a second manner of epoxy ring opening of the glycidylneodecanoate, if present. Next, the carbamated intermediary is then reacted with the silyl compound having the terminal isocyanate group, as described above. A chemical representation of the resin composition of the second embodiment is disclosed below where the silyl compound is isocyanatopropyltriethoxysilane. As shown above in either of the embodiments, the resin composition is a polyester polycarbamate, preferably a polyester tricarbamate, having a four-branch organic structure. The resin composition of the subject invention has a number-average molecular weight, Mn, of 4000 or less. Preferably, the molecular weight is from 1250 to 3000, and more preferably, from 1300 to 2500. Additionally, the resin composition of the subject invention has a non-volatile content of from 50 to 90, preferably from 60 to 75, percent non-volatile by weight. The resin composition also has a polydispersity of 1 to 2 and preferably from about 1.01 to 1.5. It is to be understood that all of the preceding chemical representations are merely two-dimensional chemical representations and that the structure of these chemical representations may be other than as indicated. Further, the intermediates illustrated are but one of many different intermediates that may result and the invention is not necessarily limited to the reactions with such intermediates. The following examples illustrate the formation of the resin composition of the subject invention, as presented herein, and are intended to illustrate and not limit the subject invention. EXAMPLES Examples 1 through 3 illustrate the formation of the resin composition according to the subject invention. Example 1 is formed according to the first embodiment and Examples 2 and 3 are formed according to the second embodiment. The resin composition was prepared by adding and reacting the following parts listed in Tables 1-3, by weight, unless otherwise indicated. Specifically, Table 1 lists the first compound in Example 1 and the formation of a polyester in Examples 2 and 3 for use in the subject invention. TABLE 1 Example 1 Example 2 Example 3 Amount Weight Amount Weight Amount Weight Reactant (grams) % (grams) % (grams) % First 136.0 100.0 720.0 9.2 746.0 9.5 Compound Second 0.0 0.0 4432.0 56.2 4390.0 56.0 Compound Carboxylic 0.0 0.0 2730.0 34.6 2704.0 34.5 Acid Anhydride TOTAL 136.0 100.0 7882.0 100.0 7840.0 100.0 The first compound is pentaerythritol (PE), the second compound is glycidylneodecanoate, commercially available as CARDURA E 10P, and the carboxylic acid anhydride is hexahydrophthalic anhydride (HHPA). In Example 1, 136 grams of PE are used. In Example 2, 2730.0 grams of HHPA were added in a reaction flask to 720.0 grams of PE, i.e., the branched compound, to form the first intermediate compound. The reaction flask, including the PE and HHPA, was heated with a conventional heat supply to a temperature of 120° C. to 125° C. An exotherm was observed which was maintained below 145° C., by use of xylene as a solvent and cooling. After this exotherm, the batch was allowed to cool and was maintained at 135-140° C. for approximately one hour. Standard titration for acid number revealed that the reaction to form the first intermediate compound was complete (200 to 220 mg KOH/gram). The completeness of the reaction between the PE and HHPA was also monitored with IR Spectroscopy noting the absence of an anhydride peak. The reaction mixture was cooled to 120° C. and 4432.0 grams of CARDURA E 10S were added to the first intermediate compound to form a second intermediate compound. Another exotherm was observed, which was controlled below 140° C. by metered addition of CARDURA E 10S and cooling. After the addition, the reaction was maintained between 135-140° C. until standard titration for acid number revealed that the reaction to form the second intermediate compound was complete (<3 mg KOH/gram). The completeness of this reaction was also monitored with IR Spectroscopy noting the absence of an epoxide peak. The second intermediate compound had a hydroxyl number of 160 to 175 mg KOH/gram/solids. In Example 3, 2704.0 grams of HHPA were added in a reaction flask to 746.0 grams of PE, i.e., the branched compound, to form the first intermediate compound. The reaction flask, including the PE and HHPA, was heated with a conventional heat supply to a temperature of 120° C. to 125° C. An exotherm was observed which was controlled to below 145° C., by use of xylene as solvent and cooling. After this exotherm, the batch was allowed to cool and was maintained between 135-140° C. for approximately one hour. Standard titration for acid number revealed that the reaction to form the first intermediate compound was complete (200 to 220 mg KOH/gram). The completeness of the reaction between the PE and HHPA was also monitored with IR Spectroscopy noting the absence of an anhydride peak. The reaction mixture was cooled to 120° C. and 4390.0 grams of CARDURA E 10P were added in small portions to the first intermediate compound to form a second intermediate compound. Another exotherm was observed, which was controlled below 140° C. by cooling and proper metering of the CARDURA E10S. After the addition, the reaction was maintained at 135-140° C. until standard titration for acid number revealed that the reaction to form the second intermediate compound was complete (<3 mg KOH/gram). The completeness of this reaction was also monitored with IR Spectroscopy noting the absence of an epoxide peak. The second intermediate compound had a hydroxyl number of 160 to 175 mg KOH/gram/solids. The first compound of Example 1 and the second intermediate compound from Examples 2 and 3 were then reacted with a carbamate compound to form a carbamated intermediary, as set forth in Table 2. TABLE 2 Example 1 Example 2 Example 3 Amount Weight Amount Weight Amount Weight Reactant (grams) % (grams) % (grams) % First 136.0 37.2 0.0 0.0 0.0 0.0 Compound Second 0.0 0.0 897.6 84.5 2324.0 84.4 Intermediate Compound Carbamate 230.0 62.8 165.0 15.5 430 15.6 Compound TOTAL 366.0 100.0 1062.6 100.0 2754.0 100.0 The carbamate compound is methyl carbamate. In Example 1, 150 grams each of toluene and xylene (solvents) were added in a reaction flask to the 136 grams of pentaerythritol. Next, 230 grams of methyl carbamate were added to the reaction flask along with 0.3 grams of dibutyl tin oxide (DBTO), the catalyst. Standard titration for hydroxyl number revealed that the initial mixture had a hydroxyl number of 167.4 mg KOH/g. The reaction flask was heated with a conventional heat supply to a temperature of 123° C. The amount of methyl carbamate added was just enough to trans-carbamate 3 equivalents of hydroxyl groups. The batch was maintained between 120-125° C. and the reaction was stopped when the amount of the methanol by-product collected was equal to the theoretical amount to achieve 75% carbamation. The amount of carbamation was determined by measuring the methanol by-product because the tricarbamate of pentaerythritol is not very soluble in xylene and precipitates out making the determination of hydroxyl number difficult. Excess methyl carbamate was removed by vacuum distillation. Additional solvent was added in an amount of 50 g of methylpropyl ketone. In Example 2, 897.6 grams of the second intermediate compound (from Table 1) were mixed with 165.0 grams of methyl carbamate and 1.4 grams of dibutyl tin oxide (DBTO) in 200 grams of toluene. The mixture was heated with a conventional heat supply to a temperature of 120° C. to 125° C., such that carbamation took place with the azeotropic removal of methanol as the side product. The reaction was continued until the hydroxyl number was determined to be 25.6 mg KOH/g/NV by titration to form the carbamated intermediary. This corresponds to 85% of the hydroxyl groups being trans carbamated. Excess methyl carbamate was removed by vacuum distillation. Next, the carbamated intermediary was dissolved in 104 grams of a solvent, Solvesso 100 to a final non-volatile (NV) of 89% by weight. In Example 3, 2324.0 grams of the second intermediate compound (from Table 1) were mixed with 430.0 grams of methyl carbamate and 4.8 grams of DBTO in 109.6 grams of toluene. The mixture was heated with a conventional heat supply to a temperature of 120° C. to 125° C., such that carbamation took place with the azeotropic removal of methanol as the side product. The reaction continued until the hydroxyl number was determined to be 26.2 mg KOH/g/NV by titration to form the carbamated intermediary. This results in 84% of the hydroxyls being trans carbamated. Excess methyl carbamate was then removed by vacuum distillation. Next, the carbamated intermediary was dissolved in 700 grams of a solvent, Solvesso 100, to a final non-volatile (NV) of 73.9% by weight. Next, the resin composition was prepared by adding and reacting the carbamated intermediaries from Table 2 with the silyl compound as listed in Table 3 below. TABLE 3 Example 1 Example 2 Example 3 Amount Weight Amount Weight Amount Weight Reactant (grams) % (grams) % (grams) % Carbamated 85.0 56.1 850 90.8 1450.0 93.3 Intermediary Silyl Com- 66.5 43.9 86.8 9.2 — — pound A Silyl Com- — — — — 103.0 6.7 pound B TOTAL 151.5 100.0 936.8 100.0 1553 100.0 Silyl compound A is 3-isocyanatopropyltriethoxysilane and silyl compound B is 3-isocyanatopropyltrimethoxysilane. In Example 1, 66.5 grams of the silyl compound A were added in the reaction flask to 85 grams of the carbamated intermediary (from Table 2). The reaction flask was heated with a conventional heat supply to a temperature of 106° C. It is desired to continue the reaction until all of the isocyanate groups present from the silyl compound have reacted with the hydroxyl groups of the carbamated intermediary. The resultant resin composition had 0% isocyanate groups, a non-volatile content of 65.2%, and an equivalent weight of 170 g/carbamate and 170 g/ethoxy (from triethoxysilyl group). The resultant resin composition has a theoretical weight-average molecular weight of 470 and a poly-dispersity of from 1.01-1.1. In Example 2, 86.8 grams of the silyl compound A were added in the reaction flask to 850 grams of the carbamated intermediary (from Table 2). The reaction flask was heated with a conventional heat supply to a temperature of 82° C. It is desired to continue the reaction until all of the isocyanate groups present from the silyl compound have reacted with the hydroxyl groups of the carbamated intermediary. The resultant resin composition had 0% isocyanate groups, a number-average molecular weight of 2115, a polydispersity of 1.6, a non-volatile content of 71%, and an equivalent weight of 470 g/carbamate and 888 g/ethoxy (from triethoxy silyl group). In Example 3, 103.0 grams of the silyl compound A were added in the reaction flask to 1450.0 grams of the carbamated intermediary (from Table 2). The reaction flask was heated with a conventional heat supply to a temperature of 76° C. It is desired to continue the reaction until all of the isocyanate groups present from the silyl compound have reacted with the hydroxyl groups of the carbamated intermediary. The resultant resin composition had 0% isocyanate groups, a number-average molecular weight of 1778, a polydispersity of 1.03, a non-volatile content of 69.7%, and an equivalent weight of 468 g/carbamate and 884 g/methoxy (from trimethoxysilyl group). The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings, and the invention may be practiced otherwise than as specifically described. | <SOH> BACKGROUND OF THE INVENTION <EOH>Various resin compositions are known for use in coating compositions that include silyl compounds and carbamate compounds. Typically, the resin compositions include a first compound having a plurality of hydroxyl groups, such as a diol or a polyester or polyether polyol. Examples of such compositions are disclosed in U.S. Pat. Nos. 6,602,964; 6,375,789; and 6,319,311. These patents disclose a resin composition formed from a silane carbamate compound. To form the silane carbamate compound, a silyl compound is reacted with diol, which forms the carbamate group with an isocyanate group of the silyl compound. However, for this reaction to proceed, the conditions must be precisely controlled and certain catalysts are used to ensure the formation of the silane carbamate compound. None of these resin compositions include a first compound having carbamate functionality and silyl functionality separate from the carbamate functionality, since the silyl compound and the carbamate compound are reacted to form the silane carbamate compound, prior to reaction with the first compound. Therefore, there are no secondary groups available for supplemental cross-linking. Another example of a resin composition is disclosed in U.S. Pat. No. 6,451,930. The '930 patent discloses a resin composition that includes two distinct components. The first component is as a polyester polymer having a carbamate group and the second component is an oxyalkylsilyl monomer containing a silyl group. The first component does not include primary carbamate groups that are available for cross-linking, nor does the second component include terminal isocyanate groups available for reacting with the unreacted hydroxyl groups of the first component. Therefore, like the resin composition described above, this resin composition does not have the capability of increased cross-linking. Accordingly, it would be advantageous to provide a resin composition that has increased cross-linking capability for use in a coating composition. The increased cross-linking capability of the coating composition would allow for linking with various cross-linkers, which when applied to a substrate produces a film having improved physical properties. | <SOH> SUMMARY OF THE INVENTION <EOH>A polyester resin composition is disclosed. The resin composition of the subject invention is utilized in a coating composition and exhibits improved scratch and mar characteristics. This resin composition is the reaction product of a first compound, a carbamate compound, and a silyl compound. The first compound has a plurality of hydroxyl groups and the carbamate compound is reactive with the hydroxyl groups of the first compound. Further, the carbamate compound is added in an amount sufficient to form a carbamated intermediary. The carbamated intermediary has at least one primary carbamate group available for cross-linking and has unreacted hydroxyl groups. The silyl compound, which has a terminal isocyanate group, reacts with the unreacted hydroxyl groups of the carbamated intermediary to form the resin composition. The silyl compound also includes silylalkoxy groups which, after the terminal isocyanate group has reacted with the unreacted hydroxyl groups, are available for secondary cross-linking. A method of preparing the polyester resin composition is also disclosed. According to this method, the hydroxyl groups of the first compound are reacted with the carbamate compound to form the carbamated intermediary. The carbamated intermediary has unreacted hydroxyl groups which are further reacted with the silyl compound to form the resin composition having available carbamate groups for cross-linking and available silylalkoxy groups for secondary cross-linking. The general object of the subject invention is to develop a polyester resin composition for use in a coating composition to produce films that have improved scratch and mar characteristics. Without intending to be bound by theory, it is believed that the improved results are obtained because the resin composition has an increased cross-linking capability due to the carbamate groups from the carbamated polyester and due to the silylalkoxy groups from the silyl compound. The primary carbamate group is available for cross-linking and the silylalkoxy groups are available for secondary cross-linking. It is this cross-linking which provides the improved scratch and mar characteristics in the films of the coating composition. Further, the silyl compound reduces the viscosity and surface tension of the resin composition, while also using less solvent to reduce the viscosity for application of the coating composition. detailed-description description="Detailed Description" end="lead"? | 20040212 | 20060516 | 20050818 | 97379.0 | 0 | BOYKIN, TERRESSA M | POLYESTER RESIN COMPOSITION FOR USE IN A COATING COMPOSITION AND METHOD OF PREPARING THE SAME | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,777,765 | ACCEPTED | Method and an arrangement in a radar level gauging system | A method, an arrangement and a radar level gauging system for preventing interference, which radar level gauging system comprises at least two radar level gauges arranged to measure a filling level of a product kept in a container. Microwave pulses are transmitted towards the surface of said product and microwave pulses reflected by said surface are received by said at least two radar level gauges. Information is provided with said microwave pulses and said information is used for controlling the measurement pulses of said at least two radar level gauges. | 1. A method for preventing interference in a radar level gauging system comprising at least two radar level gauges arranged to measure a filling level of a product kept in a container, the method comprising the steps of: transmitting microwave pulses towards a surface of said product; receiving said microwave pulses reflected from said surface; determining the filling level of said product based upon said received microwave pulses; modulating said microwave pulses to carry information with said microwave pulses; and communicating using said information for controlling the measurement pulses of said at least two radar level gauges. 2. A method according to claim 1, wherein said information is provided by making packets of said microwave pulses, whereby the packets have different lengths for different information. 3. A method according to claim 1, wherein said information is used for controlling the timing of the measurement pulses of said at least two radar level gauges. 4. A method according to claim 1, wherein said information is used for controlling the pulse repetition frequency of the measurement pulses of said at least two radar level gauges. 5. A method according to claim 1, wherein said information is used for controlling the polarization of the measurement pulses of said at least two radar level gauges. 6. A method according to claim 1, wherein said information is used for controlling the frequency bands with which said at least two radar level gauges transmit and receive microwaves. 7. A method according to claim 3, wherein the method further comprises the steps of: detecting any pulses from at least one other radar level gauge present in the container; if pulses from one or more other radar level gauge(s) are detected, attempting to establish contact with said one or more other radar level gauge(s) by transmitting said information and listening for an acknowledgement from said one or more other radar level gauge(s); if contact is established, determining in which order said at least two radar level gauges are to measure by defining at least a first and a second radar level gauge. 8. A method according to claim 7, further comprising the step of providing an alert signal indicating that at least one other radar level gauge is detected but no communication is established to thereby prevent interference. 9. A method according to claim 7, wherein the step of detecting is repeated with a predetermined time interval. 10. A method according to claim 7, further comprising the steps of: measuring the filling level of said product using the defined first radar level gauge; sending a message with said information to the defined second radar level gauge when the measuring using said first radar level gauge is done; measuring the filling level of said product using said second radar level gauge; sending a message with said information to said first radar level gauge when the measuring using said second radar level gauge is done. 11. A method according to claim 10, wherein said first radar level gauge is waiting for said message from said second radar level gauge during a predetermined period of time and if no message is received within that time period said first radar level gauge starts measuring in a stand alone mode. 12. A method according to claim 10, wherein said message is a stop word. 13. An arrangement in a radar level gauge for measuring a filing level of a product kept in a container, wherein said arrangement comprises: a transmitted arranged to transmit microwave pulses towards a surface of said product; a receiver arranged to receive said microwave pulses reflected by said surface; measurement circuitry coupled to the transmitter and receiver for determining the filling level of said product based upon the received microwave pulses; communication means arranged to modulate information with said microwave pulses and to transmit said information to at least one other radar level gauge and to receive information from the at least one other radar level gauge. 14. An arrangement according to claim 13, wherein said communication means is arranged to make packets of said microwave pulses having different lengths for different information. 15. An arrangement according to claim 13, further comprising storage means arranged to store said information. 16. An arrangement according to claim 13, wherein said communication means is arranged to detect any pulses from the at least one other radar level gauge present in the container, and to attempt to establish contact with said one or more other radar level gauge(s). 17. An arrangement according to claim 16, further comprising alerting means arranged to provide an alert signal indicating that the at least one other radar gauge is detected but no communication is established to thereby prevent interference. 18. An arrangement according to claim 13, wherein said information is used to prevent interference between said radar level gauge and at least one other radar level gauge present in said container by controlling the timing of the measurement pulses from said radar level gauge and one or more other radar level gauge. 19. An arrangement according to claim 13, wherein said information is arranged to prevent interference between said radar level gauge and at least one other radar level gauge present in said container by controlling pulse repetition frequency of the measurement pulses from said radar level gauge and one or more other radar level gauge. 20. An arrangement according to claim 13, wherein said information is used to prevent interference between said radar level gauge and at least one other radar level gauge present in said container by controlling a polarization of the measurement pulses from said radar level gauge and one or more other radar level gauge. 21. An arrangement according to claim 13, wherein said radar level gauge is arranged to measure the filling level of said product by using at least two different frequency bands and said information is arranged to prevent interference between said radar level gauge and at least one other radar level gauge present in said container by controlling said frequency bands. 22. A level gauging system comprising at least two radar level gauges arranged to measure a filling level of a product kept in a container, wherein at least one of said at least two radar level gauges comprises: a transmitter arranged to transmit microwave pulses towards a surface of said product; a receiver arranged to receive said microwave pulses reflected by said surface; measurement circuitry coupled to the transmitter and receiver for determining the filling level of said product based upon the received microwave pulses; communication means for modulating information with said microwave pulses and for transmitting said information to at least one other radar level gauge and for receiving information from the at least one other radar level gauge. | BACKGROUND OF THE INVENTION 1. Field of the Invention The present patent application relates to the field of radar gauges in radar level gauging systems, and particularly to radar gauges allowing for a prevention of interference in the level gauging system as well as a method for such prevention. 2. Description of the Related Art Radar level gauges are commonly used today for measuring the level of the surface of a product kept in a container, such as a tank. Two different types of radars are principally used in such level gauging, pulse radar gauges and Frequency Modulated Continous Wave (FMCW) radar gauges. The pulse radar uses the pulse-shaped amplitude modulation of the wave to be radiated and determines the direct time interval between transmission and reception of the pulses. The FMCW radar determines the transit time in an indirect way by emitting a frequency-modulated signal and differentiating between the emitted and the received instantaneous frequency. In certain applications, such as the process industry, there are a need for installing more than one radar gauge, e.g. for redundancy purpose and/or using one radar gauge for level control and another for measuring. The presence of two or more radar gauges in the same container will lead to a certain interference between these gauges. This problem is negligible for an FMCW radar gauge type, but is serious for a pulse radar gauge type. This is due to the fact that an FMCW radar only listens within an interval of about 100 kHz, while a pulse radar is open to the whole frequency band. A pulse radar transmits short pulses in the size of nanoseconds (ns) modulated around one frequency, e.g. 6.3 or 26 GHz, while an FMCW radar is scanning the frequency within a defined frequency band, e.g. 9.5-10.5 GHz. In the case when more than one pulse radar level gauge is installed in a container, the pulses from one radar level gauge will interfere with the measuring of the other radar level gauge(s) and vice versa, unless the radar level gauges transmitting pulses, transmit these pulses in a synchronized manner or by other means separated. Therefore, it would be desirable to provide a method and an arrangement for preventing interference between radar level gauges installed in a container for measuring the filling level of a product kept in the container. A method and arrangement which are possible to apply to already existing radar level gauges. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for preventing interference in a radar level gauging system comprising at least two radar level gauges arranged to measure a filling level of a product kept in a container. This object is achieved through a method in which microwave pulses are transmitted towards the surface of said product and microwave pulses reflected by said surface are received by said at least two radar level gauges, wherein information is provided with said microwave pulses and said information is used for controlling the measurement pulses of said at least two radar level gauges. Another object of the invention is to provide an improved arrangement in a radar level gauge allowing for a prevention of interference in a radar level gauging system for measure a filling level of a product kept in a container. This object is achieved through providing a transmitter arranged to transmit microwave pulses towards a surface of said product, a receiver arranged to receive said microwave pulses reflected by said surface, measurement circuitry coupled to the transmitter and receiver for determining the filling level of said product based upon the received microwave pulses, and communication means arranged to provide information with said microwave pulses and to transmit said information to one or more other radar level gauge(s) and to receive information from one or more other radar level gauge(s). Still another object of the present invention is to provide an improved radar level gauging system for preventing interference comprising at least two radar level gauges arranged to measure a filling level of a product kept in a container. This object has been achieved through providing at least one of said at least two radar level gauges with a transmitter arranged to transmit microwave pulses towards a surface of said product, a receiver arranged to receive said microwave pulses reflected by said surface, measurement circuitry coupled to the transmitter and receiver for determining the filling level of said product based upon the received microwave pulses, and communication means arranged to provide information with said microwave pulses and to transmit said information to one or more other radar level gauge(s) and to receive information from one or more other radar level gauge(s). A method and an arrangement in a radar level gauge for preventing interference in a radar level gauging system comprising at least two radar level gauges has been invented, where the measuring with said at least two radar level gauges can be synchronized or by other means separated due to a communication between the radar level gauges present in the container. Still other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, wherein like reference characters denote similar elements throughout the several views: FIG. 1 is a schematic representation of a container in which three pulse radar level gauges are installed according to one embodiment of the present invention; FIG. 2 is a flowchart showing the inventive method steps for preventing interference between two or more pulse radar gauges in a level gauging system. DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS Referring to FIG. 1, a container indicated generally at 10 is filled with a product 11, the height or level of which is to be determined utilizing a pulse radar level gauge, which measures the distance to a surface 12 of the product 11. In the embodiment shown in FIG. 1, three pulse radar level gauges 13a, 13b, 13c are installed and used for measuring the filling level of the product 11. There may, however, be any number of pulse radar level gauges installed suitable for different applications. The container 10 may e.g. be a tank on a ship, in a process industry or in an oil refinery or may be a dam or pond. The product may be a liquid such as oil or water, a gas, pulverized solid material such as sand or stone powder or other chemical compounds. The pulse radar level gauges 13a, 13b, 13c are mounted on a container port at the top of the container 10 and is sealed relative thereto. The pulse radar level gauges 13a, 13b, 13c each comprise a horn antenna 15a, 15b, 15c which transmits microwaves towards the product surface 12 and receives reflected microwaves from the product surface 12 to provide an indication of the level of the product 11 kept in the container 10. It should be noted that antennas other than horn antennas may of course be used, such as paraboloidal antennas or rod antennas. As a remark, the pulse radar level gauges 13a, 13b, 13c measure the distance from the top to the surface 12 of the product 11, but as the container height is known it is straightforward to recalculate this distance to the level which is the height of the product 11. Each of the radar level gauges 13a, 13b, 13c further comprises a waveguide 16a, 16b, 16c feeding microwaves between the horn antenna 15a, 15b, 15c and an electronic unit 17a, 17b, 17c in which the microwaves are generated and in which received microwaves are converted into electrical signals. The electronic unit 17a, 17b, 17c used for transmitting microwaves on a transmitting channel, Tx, and receiving the reflected microwaves on a receiving channel, Rx, is well known and is shown only schematically. The electronic units 17a, 17b, 17c further comprise communication interfaces (not shown) to be able to send and receive information, e.g. send the received microwave signals to a signal-processing unit. The radar level gauge used in the preferred embodiment of the present invention is a pulse radar level gauge transmitting short carrier wave pulses, e.g. 1 nanosecond (ns), having in the preferred embodiment a 2 MHz Pulse Repetition Frequency (PRF). The PRF is normally a predetermined value stored in the hardware of the pulse radar level gauge. If the level gauging system comprises more than one pulse radar level gauge transmitting on the same frequency, e.g. 6 GHz, these gauges will interfere with each other. A PRF of 2 MHz will give a 0.5 μs time gap between the transmitted pulses. In a large container, e.g. having a height of about 40 m, the time for a pulse to travel up and down the container will be 0.2 μs. This means that the gauges are sensitive to interference 40% of the time gap between two transmitted pulses. The pulse radar level gauge of the present invention “listens” on the receiving channel, Rx, to detect other pulse radar level gauges within the container, i.e. to detect pulses from other pulse radar level gauges. For example, in a stand alone mode the radar level gauges transmit pulses during 2 seconds and “listens” for 0.1 second, which provides 5%. Thus, the risk of not detecting other radar level gauges is small. If there are more than one pulse radar level gauge present in the container, these gauges are arranged to communicate through coded information in the transmitted pulses and to use this coded information, for example, to control the timing of the measurement pulses of the radar level gauges (to synchronize the measuring). Thus, each radar level gauge is provided with two communication interfaces, one interface outside the container in the electronic unit and the other interface within the container via the transmitted and received radar pulses. The coding is stored in storage means, such as a memory, of the pulse radar level gauges, i.e. in the software. Therefore, it is possible to apply the inventive method on already existing pulse radar level gauges. Each pulse radar level gauge has a unique unit-ID number, which may be used to identify the different pulse radar level gauges. The coded information may, as described above, control the timing of the measurement pulses of the radar level gauges, i.e. controlling the radar level gauges to measure in different timeframes. However, besides controlling the timing of the radar level gauges, the information may be used to control the PRF of the different radar level gauges, which normally is stored in the hardware of the radar level gauges, but could be used to prevent interference by letting the different radar level gauges have different PRF. Another use of the coded information to prevent interference, is to control the polarization of the transmitted microwave pulses. And, if dual band radar level gauges are used, i.e. radar level gauges having two versions of the electronics available (such as 6 and 26 GHz) for use in different situations, the coded information may be used to control the frequencies with which the different radar level gauges are measuring the filling level of the product. The coded information may also be used to increase security of the measurements. By sending the latest measurement result in the information, the radar level gauge next in turn can compare the sent measurement result with the new measurement result etc., and if there is a divergence (more than a predetermined value) the radar level gauge sends an alarm to the operator of the level gauging system. Other parameters than the latest measurement result may be sent, such as the signal strength etc. The coded information may be provided by making packets of the transmitted pulses and changing the length of the packet on the PRF sequence. Different kind of information will have different lengths of packets. Just as an example, a packet having 100 pulses (will take 50 μs) means a logical 1 and a packet having 300 pulses (will take 150 μs) means a logical 0 and that the time gap between two packets is 250 μs. In the preferred embodiment of the present invention, the procedure for preventing interference between two or more pulse radar level gauges in the level gauging system, shown in FIG. 2, is as follows: 1. The first radar level gauge 13a measures the level of the fluid surface 12 (step 21) by transmitting microwaves towards and receiving reflected microwaves from the fluid surface 12 in a stand alone measurement mode; 2. The radar level gauge 13a listens repeatedly with a predetermined interval on the receiving channel to detect other pulse radar gauges present in the container 10 (step 22) transmitting pulses with the same frequency. If no other radar level gauges are detected the radar level gauge 13a continues to measure the fluid level in the stand alone measurement mode (step 21); 3. If, however, a second 13b and/or a third radar level gauge 13c is/are detected, the first radar level gauge 13a attempts to establish a contact with the other gauge(s) (step 23). Hereby the first radar level gauge 13a transmits coded information, i.e. coded packets of pulses, repeatedly to make sure that the other gauge(s) will be able to detect this information in a listening mode; 4. If contact can't be established, the first radar gauge 13a sends an alarm to the operator (step 24), saying that there are several gauges measuring and that the measurement results may be wrong. Thereafter, the first radar gauge 13a continues to measure the fluid level in the stand alone measurement mode (step 21) and attempts to establish contact again at the next “listening session” (after two more seconds); 5. If contact has been established, i.e. the other gauge(s) 13b, 13c has/have sent an acknowledgement in return, the radar level gauges 13a, 13b, 13c communicate with each other about which timeframes to use (step 25), i.e. determine in which order the gauges 13a, 13b, 13c are to measure and defining a first radar gauge 13a, a second radar gauge 13b and a third radar gauge 13c. For example, the radar level gauges may determine the order based on their unique unit-ID numbers. The radar level gauge having the lowest unit-ID number starts measuring etc. Several known protocols may be used for this negotiation or communication. The radar level gauges can, for example, send a stop word when the measuring is done, telling which radar level gauge it is and that it is done measuring, especially in the case of more than two radar level gauges present. Then the next radar level gauge in turn will know that it can start measuring, and so on; 6. The defined first radar gauge 13a starts measuring the fluid level and sends a message to the defined second radar gauge 13b when the measuring is done (step 26) and so on. Said message is in the preferred embodiment the above described stop word. There is a predetermined time limit for how long the radar level gauges are waiting for the message before they start measuring in the stand alone mode again (step 21). Thus, while there have been shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present patent application relates to the field of radar gauges in radar level gauging systems, and particularly to radar gauges allowing for a prevention of interference in the level gauging system as well as a method for such prevention. 2. Description of the Related Art Radar level gauges are commonly used today for measuring the level of the surface of a product kept in a container, such as a tank. Two different types of radars are principally used in such level gauging, pulse radar gauges and Frequency Modulated Continous Wave (FMCW) radar gauges. The pulse radar uses the pulse-shaped amplitude modulation of the wave to be radiated and determines the direct time interval between transmission and reception of the pulses. The FMCW radar determines the transit time in an indirect way by emitting a frequency-modulated signal and differentiating between the emitted and the received instantaneous frequency. In certain applications, such as the process industry, there are a need for installing more than one radar gauge, e.g. for redundancy purpose and/or using one radar gauge for level control and another for measuring. The presence of two or more radar gauges in the same container will lead to a certain interference between these gauges. This problem is negligible for an FMCW radar gauge type, but is serious for a pulse radar gauge type. This is due to the fact that an FMCW radar only listens within an interval of about 100 kHz, while a pulse radar is open to the whole frequency band. A pulse radar transmits short pulses in the size of nanoseconds (ns) modulated around one frequency, e.g. 6.3 or 26 GHz, while an FMCW radar is scanning the frequency within a defined frequency band, e.g. 9.5-10.5 GHz. In the case when more than one pulse radar level gauge is installed in a container, the pulses from one radar level gauge will interfere with the measuring of the other radar level gauge(s) and vice versa, unless the radar level gauges transmitting pulses, transmit these pulses in a synchronized manner or by other means separated. Therefore, it would be desirable to provide a method and an arrangement for preventing interference between radar level gauges installed in a container for measuring the filling level of a product kept in the container. A method and arrangement which are possible to apply to already existing radar level gauges. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, it is an object of the present invention to provide a method for preventing interference in a radar level gauging system comprising at least two radar level gauges arranged to measure a filling level of a product kept in a container. This object is achieved through a method in which microwave pulses are transmitted towards the surface of said product and microwave pulses reflected by said surface are received by said at least two radar level gauges, wherein information is provided with said microwave pulses and said information is used for controlling the measurement pulses of said at least two radar level gauges. Another object of the invention is to provide an improved arrangement in a radar level gauge allowing for a prevention of interference in a radar level gauging system for measure a filling level of a product kept in a container. This object is achieved through providing a transmitter arranged to transmit microwave pulses towards a surface of said product, a receiver arranged to receive said microwave pulses reflected by said surface, measurement circuitry coupled to the transmitter and receiver for determining the filling level of said product based upon the received microwave pulses, and communication means arranged to provide information with said microwave pulses and to transmit said information to one or more other radar level gauge(s) and to receive information from one or more other radar level gauge(s). Still another object of the present invention is to provide an improved radar level gauging system for preventing interference comprising at least two radar level gauges arranged to measure a filling level of a product kept in a container. This object has been achieved through providing at least one of said at least two radar level gauges with a transmitter arranged to transmit microwave pulses towards a surface of said product, a receiver arranged to receive said microwave pulses reflected by said surface, measurement circuitry coupled to the transmitter and receiver for determining the filling level of said product based upon the received microwave pulses, and communication means arranged to provide information with said microwave pulses and to transmit said information to one or more other radar level gauge(s) and to receive information from one or more other radar level gauge(s). A method and an arrangement in a radar level gauge for preventing interference in a radar level gauging system comprising at least two radar level gauges has been invented, where the measuring with said at least two radar level gauges can be synchronized or by other means separated due to a communication between the radar level gauges present in the container. Still other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. | 20040213 | 20060207 | 20050818 | 62509.0 | 0 | GREGORY, BERNARR E | METHOD AND AN ARRANGEMENT IN A RADAR LEVEL GAUGING SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,777,876 | ACCEPTED | Electronic control system used in security system for cargo trailers | A security system is provided for a cargo container having a door. An electronic control unit is provided for monitoring the locked status of the door. The electronic control unit is operably communicable with a remote computer terminal. A first software control program is located within the electronic control unit to monitor the locked status of the door. A second software control program is located within the remote computer terminal and is capable of retrieving activity and functions from the first software control program. A protocol is provided to facilitate communication between the electronic control unit and the remote computer terminal. | 1. A security system for a cargo container having a door comprising: an electronic control unit operably communicable with a remote computer terminal and capable of performing at least one activity and monitoring at least one function; a first software control program within the electronic control unit to monitor the activity and the function; and a second software control program within the remote computer terminal capable of retrieving the activity and the function from the first software control program. 2. The security system as claimed in claim 1 further comprising a first voltage source to supply power to the electronic control unit. 3. The security system as claimed in claim 2 further comprising a second voltage source to supply power to the electronic control unit if the first voltage source is inadequate. 4. The system as claimed in claim 3 wherein the second voltage source is a battery. 5. The security system as claimed in claim 1 further comprising a protocol to facilitate communication between the electronic control unit and the remote computer terminal. 6. The security system as claimed in claim 5 wherein the protocol facilitates wireless communication between the electronic control unit and the remote computer terminal. 7. The security system as claimed in claim 1 wherein the electronic control unit includes a microcontroller, a nonvolatile memory, a real time clock, a radio frequency receiver, an analog to digital converter, a temperature sensor for measuring the temperature, a motor driver, and a serial communication port. 8. The security system as claimed in claim 7 wherein the electronic control unit includes a means to record a plurality of events in the nonvolatile memory. 9. The security system as claimed in claim 1 further comprising a lock operably coupled to the electronic control unit and disposed adjacent to the door in order to lock the door in a closed position, thereby defining a locked status. 10. The security system as claimed in claim 9 wherein the electronic control unit monitors the locked status. 11. The security system as claimed in claim 7 wherein the radio frequency receiver is capable of receiving a remote command. 12. A cargo security system as claimed in claim 7 wherein the real time clock is settable with a clock operably coupled to the remote terminal computer. 13. A cargo security system as claimed in claim 7 wherein the temperature creates an alarm condition. 14. A cargo security system as claimed in claim 7 wherein the electronic control unit receives a command from a keyfob device. 15. A method of monitoring and recording a condition of a cargo container having a lockable door using a cargo security system comprising: an electronic control unit capable of monitoring at least one function and creating an alarm condition; a sensor capable of measuring a parameter and being operably coupled to the electronic control unit; and a remote terminal computer capable of operably communicating with the electronic control unit, the method comprising: disposing the electronic control unit within the cargo container; comparing the parameter with a table having parameter limits; and creating the alarm condition if the parameter does not comply with the parameter limits. 16. A method for controlling a cargo security system, the method comprising: providing an electronic control unit capable of performing at least one activity and monitoring at least one function, and having a software control program for controlling its activities; communicating with a remote computer terminal using a unique serial protocol; providing a program in said remote computer terminal using communication protocol to adjust security system settings; and providing a battery backup to operate the security system if an external power source is not available. 17. The method as defined in claim 16 in which said software program in said remote computer terminal enables the monitoring of system status, the retrieving of logged events, and problem diagnosis. 18. A method as defined in claim 16, including the step of providing said electronic control unit with a microcontroller, nonvolatile memory, battery backed-up real time clock, RF receiver, analog to digital converter, temperature sensor, I/O lines, motor driver, and serial communication. 19. A method as defined in claim 18 in which an event log in nonvolatile memory is kept up to date by overwriting older events by new ones and continuously maintaining the last set number of events, based on memory size. 20. A method as defined in claim 18, in which the log event records in a nonvolatile memory have a different structure to save memory space and record more information. 21. A method as defined in claim 16, including the step of automatically converting a real time clock from GMT to local time, and automatically adjusting for daylight saving time. 22. A method as defined in claim 16, in which a supply voltage is selected to extend the operational time of the back up battery, the method further comprising: measuring a main power source continuously to determine that it has enough power to supply the security system; and forcing the system to use the main power source if available, even though the back up power source has a higher voltage. 23. A method as defined in claim 16, in which the back up battery is trickle charged from the main power source to prolong its uninterrupted operation, the method comprising: measuring voltage of both batteries continuously; connecting both batteries together and allowing the charging current to flow, if the main battery voltage is sufficiently higher; protecting the charging circuit from overheating, by turning the charging current periodically on and off if there is a substantial voltage difference between both batteries. 24. A method as defined in claim 16, including the steps of measuring temperature and supply voltage; and increasing a control pulse duration in response to low temperature or voltages. 25. A method as defined in claim 16, including the step of triggering an alarm condition in response to rapid temperature or voltage changes. 26. A method as defined in claim 6, including the steps of providing a security device latch, providing one of a short reverse pulse and a high impendence to stop security device latch movement at a desired position. 27. A method as defined in claim 16, including the step of locating the security system using GPS signal and cellular phone to send control signals. 28. A method as defined in claim 27 including the step of excepting a customer's input from an intelligent keypad for sending controlled signals to the security device and for bypassing a serial protocol. 29. A method as defined in claim 16, in which the access to the system is password protected including: using a relatively low-level user password to read log, program keyfobs, and adjust configuration; using a relatively high-level user password to additionally program firmware, and change passwords; and using default user passwords with limited capability when serial memory fails. 30. A method as defined in claim 16, comprising the steps of using a license file containing pairs of security device serial numbers and associated low level user passwords. | FIELD OF THE INVENTION This invention relates to an electronic control system that is used in interfacing to and controlling various devices used in security systems for containers having doors, and also has particular application to apparatus and methods for securing roll-down and/or swing-open doors for cargo trailers, such as cargo containers, trailers, delivery vans, storage facilities, and cargo trailers. BACKGROUND A need exists for a security system that employs an electronic controller used specifically to control various devices and interface with the controlled devices using software unique to the security process employed by those devices, so that it can be used for both roll-down doors and swing-out doors. A need also exists for a security system that stores a number of information records, such as records concerning the unlocking, locking, opening or closing of the door, including the date, time, air temperature, and/or geographical location of such event. The records need to be updated in such a way that the new ones replace the oldest as soon as the maximum number of records allowed is reached. Furthermore, a need exists for an electronic control system that communicates with a unique protocol and provides a customer a secure two-way connection using a remote terminal, such as a personal computer (PC). A need exists for a PC software program to communicate with the electronic controller, update its software, adjust features, enable/disable and program input devices, calibrate, diagnose problems, and retrieve information records. The supplier should be able to control access by issuing software licenses for each electronic control system. The customer should be able to protect access to the security system by setting and maintaining software passwords. A need further exists for an electronic control system that operates on its own, without external power connected, for a maximum possible time duration, and to maintain its power source by charging it when the outside power is available and controlling which power source is used by the system. SUMMARY The disclosed apparatus and methods avoid some of the disadvantages of prior devices that do not employ an electronic control system, and add new features. In an embodiment of the invention, a security system is provided for a cargo container having a door. The security system comprises an electronic control unit capable of performing at least one activity and monitoring at least one function and being operably communicable with a remote computer terminal. A first software control program is provided within the electronic control unit to monitor the activity and the function. A second software control program is provided within the remote computer terminal and is capable of retrieving the activity and the function from the first software control program. In an embodiment of the invention, a method is provided for monitoring and recording a condition of a cargo container having a lockable door using a cargo security system. The method comprises an electronic control unit capable of monitoring at least one function and creating an alarm condition; a sensor capable of measuring a parameter and being operably coupled to the electronic control unit; and a remote terminal computer capable of operably communicating with electronic control unit. The method comprises the steps of disposing the electronic control unit within the cargo container; comparing the parameter with a table having parameter limits; and creating an alarm condition if the parameter does not comply with the parameter limits. In an embodiment of the invention, a method is provided for securing from the inside the cargo of a trailer having a container and cargo door accessible from the outside for closing the container and being movable from an open position to a closed position. The method comprises providing a security device containing a latch with a screw on the inside of the container, and a linked electronic control system. The electronic control system may be used to operate and control turning of the screw in a direction, thereby moving the latch between unlocked and locked positions. In one embodiment of the invention, the method comprises providing a control software program that controls the movement of the latch between the unlocked and the locked positions. The control software program may be located in a nonvolatile memory of the electronic controller or other memory retention device. A signal generation device may also be provided, which is capable of sending lock, unlock, or other control signals to the controller. The software determines when one of the control signals is sent from the signal generation device to the controller. For example, the unlock control signal may indicate that the security device should be in the unlocked position, but the lock control signal indicates that the security device is in the locked position. In order to maximize precision and repeatability of the security system to be able to stop at the same position at any voltage and temperature conditions, a short reverse control signal may also be applied after the main control signal is complete. In one embodiment, the method also includes storing in memory control data indicative of the most recent control signals sent from the signal generation device to the controller. In one embodiment, several different sensors could be coupled to the controller. The method includes the control software to process the sensor inputs. The security device position sensors indicate whether the security device is in the locked or unlocked position. One or more door sensors could be provided, which are also coupled to the controller. The method includes sensing, with the door sensor, whether the cargo door is in the open or closed position. A door position signal, indicative of whether the door is in the open or closed position, is sent to the controller. The method includes moving the latch from its unlocked position to its locked position, if the signal generation device sends the lock control signal to the controller, the security device position signal indicates that the latch is in the unlocked position, and the door position indicates that the door is in the closed position. In one embodiment, a memory is coupled to the controller, with the controller activity being sent through the software which allows the memory to be capable of storing control data indicative of the most recent control signal sent from the signal generation device to the controller. A more detailed explanation of the invention is provided in the following description and claims, and is illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated. FIG. 1 is a security system drawing showing the security device and the electronic control system components; FIG. 2 represents the ECU and its internal components; FIG. 3 represents a flow chart showing the ECU main functionality; FIG. 4 shows the PC-ECU communication protocol packet format; FIG. 5-12 represent a possible implementation of the PC program, where: FIG. 5 is a Data/Lock-Unlock screen without ECU-PC communication; FIG. 6 is a Data/Lock-Unlock screen with ECU-PC communication; FIG. 7 is a Configure system screen; FIG. 8 is a Program RF key-fob screen; FIG. 9 is a Firmware and password screen; FIG. 10 is a Diagnostics screen: FIG. 11 is a typical Setup screen; FIG. 12 is a Diagnostic Test Mode screen; FIG. 13 is a flow chart representing the main loop in the ECU firmware; FIG. 14 represents a flow chart of the timer interrupt routine executed every 40 msec; FIG. 15 is a flow chart representing corrupted header correction; FIG. 16 represents different types of log entries; FIG. 17 shows where passwords and software license files are stored; FIG. 18 is a flow chart representing how passwords and a software license are used to protect access to the security system, when diagnostic features are not enabled; FIG. 19 represents what a PC program user can access with different passwords, when diagnostic features are not enabled; FIG. 20 is a flow chart representing how passwords and a software license are used to protect access to the security system, when diagnostic features are enabled; FIG. 21 represents what a PC program user can access with different passwords, when diagnostic features are enabled. DETAILED DESCRIPTION In U.S. patent application Ser. No. 10/360,521, filed Feb. 6, 2003, a system is disclosed in which the inside of a cargo container is secured from the outside using a security device containing a latch with a screw on the inside of the container, and a linked electronic control system. The disclosure of U.S. application Ser. No. 10/360,521, filed Feb. 6, 2003, and which is assigned to the same assignee as the present invention, is hereby incorporated in full into the present application. Turning now to the drawings, and, more particularly, FIG. 1, there is a typical cargo security system comprising a security device 10 (including position sensors 11, a motor 12, and a latch 9), a controller, referred herein as an electronic control unit (ECU) 14, a wiring harness 13, a door sensor(s) 15, a backup battery 16, a sound creating device 17, such as a buzzer, and a serial connection 18 to a personal computer (PC) software program 19 for communication, firmware updating, adjusting features, enabling and programming input devices, diagnosing problems, and information records retrieval. In one embodiment, the cargo security system includes a controller, such as the ECU 14 (FIG. 2) which controls a security device, such 10 as a stand alone lock, or as a device that can be coupled with telematic (GPS, cellular, GLS, wireless networks, etc) or RF systems to provide the security system that logs various events, including location of the event. The ECU 14 can be comprised of a microcontroller 20 that may include internal memory (not shown) or that has memory coupled to it. A real time clock 21 (RTC) can be coupled to the ECU allow the timing of various events to be recorded in event EEPROM memory 22 coupled to the microcontroller 20. Such events may include, for example, opening or closing the door, the latch 9 moving to either an unlocked or a locked position, temperature readings, configuration and password changes, an RF key-fob ECU memory programming and erasing, firmware updates, an attempted break-in, problems or errors in the execution of commands or in the status sensed after a command. In one embodiment, the event memory 22 can record time, location, and the individual (or key-fob) associated with a particular event. The event memory 22 can be designed to control erasure of data and can be set up to override older information with newer. The RTC 21 may have an independent battery (not shown), in order to provide the time of events stored in the event memory 22. In an embodiment, a power management system can be provided to adjust the operation according to the type of power used and to allow the power input to be switched between several different power supplies, for example, such as the truck alternator or battery, a stand alone (backup) battery 16 coupled to security system, solar panels, or other appropriate power supplies. In one embodiment, the power management device 23 can enable automatic recharging of the back up battery 16, whenever it is feasible, and can sense power, remaining this battery before the latch 9 is moved to the locked position in order to determine whether adequate power is likely to remain afterwards in order to return it to the unlocked position. If, for example, there is not enough power, the ECU 14 can be programmed to trigger a visual or audible warning 17 and either not take any action, or require the user to confirm that they want the latch 9 moved to the locked position even though there may not be enough power left to move it back to the unlocked position. Another option includes selecting the power source in such a way to maximize time available to operate on the backup battery 16. In some cases, the power management 23 may use the outside power source even when the backup battery 16 has a higher voltage, in order to preserve the backup battery 16 for use when the main power is removed. The security system can be configured to run on a variety of voltages, such as, for example, 6 VDC, or 12 VDC, or even 24 VDC. A temperature sensor 29 may also be used to adjust duration of the locking and unlocking signals. The lower the temperature which naturally lowers the battery voltage, the longer the signal needs to be to make sure the latch 9 reaches the locked and unlocked positions. Also, the ECU 14 could be programmed to issue a warning, an alarm, or record a log event in case there is a sudden change in temperature, and it could also be programmed to behave differently depending on the temperature. For example, some of the power saving features may be enabled/disabled at certain temperatures, since the electronic devices may change their electrical consumption characteristic with temperature changes. The ECU 14 is operably coupled to a motor 12 and thereby controls the operation of the motor 12. In one embodiment, an H-bridge driver may be utilized as the motor control output 24 in such a way, that a positive voltage is applied to one motor 12 terminal and the ground reference to the other, in order to turn it in one direction, and when voltages are reversed, the motor 12 rotates in the opposite direction. When the movement in one direction is complete, the ECU 14 may send a short reverse control signal for the motor 12 to operate in the opposite direction. This action will allow the latch 9 movement to stop immediately, and therefore it improves precision and repeatability of the system response under different voltage and temperature conditions. A receiver, such as an RF receiver 25 may be operably coupled to the microcontroller 20. A transmitter, such as an RF two channel key-fob transmitter 26, can be provided with two RF outputs to transmit signals to the RF receiver 25. Signals transmitted from the RF transmitter 26 are the signals that are used to elicit a response from the ECU 14. For example, one RF output signal of the transmitter 26 can be used to cause the ECU 14 to activate the motor 12 and move the latch 9 to the locked position. The other transmitter 26 output can cause the ECU 14 to activate the motor 12 and move the latch 9 to the unlocked position. Alternately, an RF three channel (or any other suitable number of channel) key-fob transmitter can be used. Multiple key-fob transmitters can be provided and each might be separately coded so that the identity of the particular key-fob 26, and thus the individual entrusted with that key-fob, can be recorded in the event memory 22 with any other appropriate information regarding the particular event. If the three-channel key-fob is used, the third channel can indicate an alarm condition, or it could become a master fob to enable or disable the ECU 14 from responding to a signal from other fobs. As another alternative, the third channel could be used to initiate and perform a new key-fob programming process, if the user does not want to use the PC software 19 for the RF transmitter programming. Otherwise, the key-fobs 26 are programmable in the field using a PC. The PC program 19 may also used to erase the key-fob memory in RF receiver 25 when a key-fob 26 is stolen or lost. The ECU 14 may be provided with a plurality of other inputs 27 or outputs 24. For example, one or two digital inputs 27 could be used to hardwire a remote keypad as an alternative to the RF operated key-fobs 26. Some keypads may provide separate lock an unlock signals, and some may use only one input for both signals. The ECU 14 could be configured to accept both types of keypads. If only one input is provided, the ECU 14 will determine the current status of the security device 10 and move the latch 9 to the opposite position, when a valid keypad signal is received. Another digital input 27 could be used with a sensor 15, for example a switch, that produces a signal when the door is open. In one form, such sensor can take the form of a magnetic switch that sends a signal when the door is opened and, thus, moves away from the magnetic switch. In another form, the magnetic switch is a magnetic reed switch. Additional digital or dry contact inputs 27 can be provided for additional external switches or sensors inputs. The ECU 14 may also use analog inputs 27 for voltage, temperature, or other measurements. For example, a light sensor may be used, providing a variable voltage or resistance input 27 to the ECU 14, to sense if the door was open, or maybe another event caused the light to be sensed. The ECU 14 can also include a plurality of outputs 24 for control signals sent to other devices. Outputs 24 could be an open collector/open drain to sink a current, or a relay type to provide electrical isolation (dry contact type). Feedback input signals, coming to the ECU inputs 27, can indicate that the security device 10 is in the locked position or is unlocked, the door is closed or opened, or that an error condition exists. In one form, an error signal is generated if two different sensors indicate opposite states, such as one sensor indicating that the security device 10 is in the locked position and the other sensor indicating that it is unlocked. In one form, an output signal 24 is sent to a device, such as a camera, to activate the device when the vehicle door is opened. When a camera is used, a recording can be made of any loading and unloading activities when the door is opened. One, or more, feedback input signals 27 can be used by the ECU 14 to activate a buzzer 17, a siren, or another warning device. In one form, a warning device is located in the cab and indicates that the security device 10 is unlocked, or that the door is opened. In selected situations, an output signal 24 can be used to lock the front of a cab hauling the cargo trailer or to disable the engine. A plurality of serial ports, such as a nine-pin connector communication port 28, that is often referred to as RS-232, can be provided to interface with one or more auxiliary devices, such as a programming terminal or computer, a keypad, a telematic device, a GPS tracking device, a serial sensing device, or a modem. Such auxiliary devices can be used to send signals to the ECU 14 to lock or unlock the security device 10. They can also be used to program the ECU 14 firmware, or to download information stored in the event memory 22 or other memory associated with the ECU 14. In one form, a keypad is provided that requires the entry of an employee identifying code to unlock the door, so that a record of the unlocking of the door can be saved in memory 22. The telematic device and GPS tracking device can be used to track the location of the cargo transport vehicle when the cargo door is opened or unlocked and send the data to a remote location. In one form, the ECU 14 is normally in the sleep mode and “awakens” when a command is sent, or a signal is sent from one of the sensors or other devices. FIG. 3 shows a functional description of a program that can be run by the ECU 14. After being turned on, the power-up process 30 will include, for example, verification 31 and status check of all states and sensor inputs. If an error condition 32 is detected during power-up (e. g. security system in unknown state), the program may try to correct it by applying an automatic lock/unlock request and/or may signal this condition to the user by flashing an LED or by activating an alarm 17. In normal situations, the ECU 14 will wait until either a “Lock request” 33, or an “Unlock request” 34 are supplied. In one form, both “Lock request” 33 and “Unlock request” 34 may come from an RF key-fob 26. If the “Lock request” 33 is generated, the program may determine whether the door is closed at 35. If the door is not closed, the program goes back to verify status 31. However, if the door is closed, the program verifies if the security device 10 is already in the locked position 36. If the security device is in the locked position, the program sends a “Locked acknowledge signal” 37 and goes back to verify status 31. If the security device 10 is not in the locked position, the program may verify if the maximum number of locking retries 38 is exceeded. This number could be programmed in the ECU 14 by the user to protect the security device 10 in case an obstruction (e.g. ice, debris) prevents the locking process. If the maximum number of retries 38 is not exceeded, the “Activate locking” 39 command is generated. At this time, the motor 12 is energized which causes the latch 9 to move to the locked position. There is a delay 40 needed for the motor 12 to operate, after which the program checks if the locking process was successful at 36. If the security device 10 is in the locked position, the program sends a “Locked acknowledge signal” 37 and goes back to verify status 31. If the security device 10 is not in the locked position, the locking process is repeated, unless the number of locking retries is exceeded. In that case, an error 41 is generated and the locking process stops. The maximum number of locking retries could be any number from 0, 1 to as much as 100 in some cases. The security device 10 “Locked acknowledge signal” 37 could be used to generate an output to the user, such as a chirp of the buzzer 17, an LED or an indicator light output, or an LCD screen output. In a different implementation, instead using a delay 40, the ECU 14 may monitor the security device 10 position sensor(s) status and disengage the motor 12, when the sensor(s) indicate that the locked position has been reached. In one form, the system can be programmed to have an automatic lock/relock feature enabled and generate automatic lock requests 42. The automatic locking may occur when the user closes the door, but does not send a “Lock request” 33 signal within a specified period of time. The automatic relocking may occur when the user requests the security device 10 to unlock, but does not open the door within a specified period of time. The time period can be programmed by the user from 0 to as much as 5 min, or even 10 min. In some cases, not shown on FIG. 3, the ECU 14 could be programmed to accept a “Lock request” 33 signal even when the door is not closed. In one instance, the request could be memorized and executed by the ECU 14 after the door closure is detected. The “Lock request” 33 also could be executed when the door is open, since the construction of the security device 10 allows the door to close even when it is in the locked position. During the closing, the security device locking mechanism (latch) 9 will move inside compressing a spring (not shown) until it has cleared the receiving device. When the door is fully closed, the compressed spring will cause the latch 9 to move back to the locked position. If the “Unlock request” 34 is generated, the program determines whether the security device 10 is already in an unlocked state 43. If it is unlocked, the program sends a security device “Unlocked acknowledge signal” 44 and goes back to verify status 31. If the security device 10 is not unlocked, the program verifies if the maximum number of unlocking retries 45 is not exceeded. This number could be programmed in the ECU 14 by the user to protect the security device 10 in case an obstruction (e.g. ice, debris) prevents the unlatching process. If the maximum number of retries 45 is exceeded, the “Activate unlocking” 46 command is generated. At this time, the motor 12 is energized which causes the latch 9 to move to the unlocked position. There is a delay 47 needed for the motor 12 to operate, after which the program checks if the unlocking process was successful. If the security device 10 is unlocked at 43, the program sends an “Unlocked acknowledge signal” 44 and goes back to verify status 31. If the security device 10 is not unlocked, the unlocking process is repeated, unless the number of unlocking retries is exceeded. In that case, an error 48 is generated and the unlocking process stops. The maximum number of unlocking retries could be any number from 0, 1 to as much as 100 in some cases. The security device 10 “Unlocked acknowledge signal” 44 could be used to generate an output to the user, such as a chirp of the buzzer 17, an LED or an indicator light output, or an LCD screen output. In a different implementation, instead using a delay 48, the ECU 14 may monitor the security device 10 position sensor(s) status and disengage the motor 12, when the sensor(s) indicate that the unlocked position has been reached. Several different communication protocols could be used for commands, status, and data exchange between the security system and a PC software 19. One of them is described in details below. This unique serial protocol has been developed to communicate with the ECU 14 through PC software 19, or a remote connection. FIG. 4 indicates main parts of this protocol. The PC software 19 issues command packets to communicate to the ECU 14 what action it should take. Each command packet 60 may contain a unique start character 50, a command character(s) 51, a password 52 (either Administrator or Access), data 53 (optional—if a command argument is needed), a check sum 54, and a unique packet end character 55. The ECU 14 may echo the command packet 60 back to the PC, if this option is selected. A modified configuration is an example of a command argument. In order to send one byte (8 bits) of data, 2 ASCII characters are used in this protocol. For example, to send a hexadecimal 8F (a binary 10001111), the communication protocol uses an ASCII “8” (hexadecimal 38) and an ASCII “F” (hexadecimal 46). Therefore, for each data byte to be transmitted, 2 ASCII characters are used. This approach may seem inefficient, but it is simple and easy to generate and decode by both ECU 14, and PC program 19. When the command 60 is executed, the ECU 14 may return a data packet 61 and a status packet 62. The data packet 61 is applicable to some commands (e.g. retrieve event log), and some of them don't have any data packet 61 associated with them. If the data packet 61 exists, it should include the start character 50, a data packet type character 56, data transmission 53, the check sum 54, and the end character 55. There may be several different data packet type characters 56, depending on how many bytes the data packet 61 contains and what is the data structure. The ECU 14 should always respond to each command 60 with the status packet 62 transmission. The status packet 62 comprises the start character 50, a status packet indicator character 57, the last command 51, a status of the command execution 59, the check sum 54, and the end character 55. In some cases, when the command 60 requires longer action from the ECU 14, or to perform several intermediate steps, there may be several status packets 62 sent to indicate the status change, and then at the end the final status packet 62 is issued. The checksum 54 for each packet is calculated to prevent accepting corrupted communication packets. In some instances the checksum could be replaced with more sophisticated methods, like CRC-16, CRC-32, or others. In one embodiment, the PC program 19 communicating with the ECU 14 may look like the one presented in FIG. 5 to FIG. 12. The program 19 needs to be able to verify software license compliance and provide a secure access to the ECU 14 to perform various tasks, including checking of the security system status, modifying the system configuration, programming RF transmitters 26, changing passwords, updating the ECU 14 firmware, adjusting the RTC 21, retrieving event memory 22, locking and unlocking the security device 10, calibrating voltages and temperature, and diagnosing problems. In order to start the PC program 19, the user needs to provide a valid password—either a User, or an Administrator password. If the User password is verified, a DataLock-Unlock screen (FIG. 5) is displayed on the PC. A second way to reach this exact screen is to provide a valid Administrator password, without installing or detecting a valid software license for the security system. At this point, the user can select one of four items from a menu bar 70. In one embodiment the “File” option 71 may let the user to load, save, or print the PC program 19 configuration or security systems' data, and also exit the program. The second option “Tools” 72 may provide the user a possibility to setup the PC program 19, adjust screen size and colors, or access other available software tools. The third option “Data” 73 may allow the user to export the event log to other PC programs in form of a text file or a spreadsheet, create graphs, or import saved data files for further processing. The last option “Help” 74 may provide written information on how to use this PC program 19 and how to configure the security system. Some of the options, described above, may not be available if the PC-ECU communication is in progress (example—setup screen FIG. 11), others may be only accessible when the communication is established (example—exporting the event log). For illustration purposes, a sample PC program 19 setup screen (FIG. 11) is provided. Using this window, the user can set a serial communication (Com) port 110, change the user password 107, install a software license file 108, or copy the current license file to a diskette 109 for installation on another PC. When the Administrator password is used and a valid license for the security system is detected, the PC program 19 may start the PC-ECU communication automatically. Otherwise, the user has to press the “Initialize” button 75. When this happens, the PC program 19 will try to establish communication with the ECU 14 and to verify the software license. It checks if the security system serial number and the Access password, stored in the ECU 14, match the pair stored in the encrypted software license file installed to work with the PC program 19. If the license is verified, the user gains access to the ECU 14, based on what type of password was used. Software licensing is described later (FIG. 17-21). At that time, the “Initialize” button 75 changes to a “Disconnect” button 76, as is shown on FIG. 6. All screens of the PC program 19, shown on FIG. 5-10, have a common area indicating the current configuration 77, the current RTC time 78, the current supply voltages 81, and the current temperature 82, and the current security system status 80 (security device locked/unlocked and door open/closed). The ECU 14 serial number and firmware version are also displayed at 79. Additionally, the program can indicate that maintenance is needed, such as by using an LED 83 either continuously turned on, or by flashing maintenance codes. The LED 83 may be also used in diagnostic mode to calibrate the security device position sensors 11. The screen LED 83 is duplicated in one of the open drain ECU outputs 24, and a real LED could be used there. The first communication screen (FIG. 6) lets the user operate the security device 10 by selecting one of the buttons at 84, and to retrieve the event memory 22 by pressing “Retrieve Data” 85. The event memory 22 may contain large number of events, as large as 2000, 4000, or even 8000. When the memory is filled with events, the oldest of them are overwritten one by one by the new ones, so there is always a fixed number stored to retrieve. The PC program 19 gives user a choice to retrieve all events, or a selected number of the latest events, or the events since the last event retrieval, or the events for the selected number of days. The events are place in a table, starting with the most recent one. There are four columns displayed: event name 86, date/time of the event 87, data high 88, and data low 89. Both data high and data low display decimal equivalents of data bytes stored in memory. The PC program 19 converts these 2 bytes to more readable information, when it exports data to a text file. The user may be given a chart explaining what the associated data bytes represent for each event. The second screen (FIG. 7) allows the user to change the system configuration by selecting options at the configuration area 90 and pressing the “Update configuration” button 91. The user can also synchronize the RTC 21 to the PC time by selecting the “Update time” button 94, change the communication baud rate at 93, and reset the ECU 14 at 92. The RTC time used by the ECU 14 is a GMT time and it is not adjusted for daylight savings. The PC program 19 knows a time zone of the PC it is running on, therefore, it automatically adjusts the RTC 21 information received form the ECU 14 to that time zone. For example, if the user uses EST time on his PC, this is the time zone that would be used in event records coming from the ECU 14, including changes for daylight saving. If the user switches the PC time to CST, all the records coming from the ECU 14 would have their time adjusted accordingly by one hour. The serial number at 79 is established during production process and cannot be changed afterwards. Standard baud rates at 93 from 19,200 bits/sec to as low as 1200 bits/sec are available. The third screen (FIG. 8) allows the user to program 96 and erase 95 the RF key-fob memory in the ECU 14. The number of transmitters 26 available could be limited or not, depending on the firmware setup. The fourth screen (FIG. 9) is only accessible to administrators and allows loading 99 and updating 100 the ECU firmware and Administrator 98 and Access 99 password changes. Any password changes are written to the ECU memory 22. In addition, if the Access password is changed, the software license file, which includes the Access passwords, is updated. After changing the Access password, the administrator must update license files on all the PC's used to service the particular security system. Otherwise, any user who's PC is not updated, will not be able to access this security system. This feature could also be used by the administrator to eliminate users who are no longer with the company, or who no longer need to have rights to communicate with a particular security system. The fifth screen (FIG. 10) is only accessible by the security system supplier. This screen provides the ability to calibrate voltages readings at 104 and temperature sensor 29 at 105, diagnose problems with sensors and other devices at 106, perform cycling operation 102 of the security device 10, and set configuration items not accessible to the regular user at 101. To make sure that all functions are done on purpose (not by incident) the operator is required to enable the diagnostic mode in configuration 101 prior to performing any other function from this screen. Diagnostic “Lock” and “Unlock” commands 103 are also provided to help diagnosing position sensors 11 malfunctioning. The diagnostic mode is automatically disabled when this screen is exited. Diagnostic test mode screen (FIG. 12) provides the operator a way of testing the security system functionality. Sensor readings are checked if they are within limits provided by a limit file loaded at 111—a text file prepared for each ECU 14 version. The test results are displayed, stored in a file, and could be printed after each test. Giving the user a possibility to change configuration 77, based on his needs, provides great flexibility of the security system and allows it to be used in many different applications. For example, a delivery truck may require autolocking option to be enabled, and a container shipped overseas may not want this feature. Low power consumption may be very important for systems using their own batteries, but a quick key-fob 26 response may be more important for the delivery truck, even though the power consumption is higher. Some, or all, of the options might be pre-configured by the supplier based on the user's needs. In the security system described hereon, the user may have the following configuration 77 choices to select: Enable a software power management—option to minimize power consumption even at the expense of slower response time; Enable autolocking—the security device 10 could lock by itself if the autolocking time expires and conditions described below are met; Enable autorelocking—the security device 10 will be locked if it is unlocked, the relock time expires, and the door is never opened; Enable hardwire control—digital lock and unlock inputs are enabled to accept external locking and unlocking command inputs 27 from switches or a keypad; Enable RF key-fob control—an RF receiver 25 is enabled to accept RF commands from a key-fob 26 to lock and unlock the security device 10; Enable backup battery recharging—the backup battery 16 can be charged from the main power source, if the conditions are right (right voltage difference, backup battery connected). If the voltage difference between the main and backup 16 batteries exceed certain limits, the charging may be turned on and off periodically to limit the average charging current/reduce heat dissipation; Enable a buzzer—a buzzer 17 or other indicator output is enabled to confirm locking and unlocking processes. If the door is open, a short chirp may be used, if it is closed, longer signals are applied to positively confirm the operation; Unrestricted locking—if this option is selected, the security device 10 will be locked (including autolocking) or unlocked regardless of the door status, otherwise the door closure is required for the security device to operate; Recharge continuous—if selected, and the backup battery 16 recharging is enabled, the charging process will be permitted regardless of the backup battery 16 voltage, otherwise there are limits set in the ECU 14 firmware on when the charging should start and stop, in order to maintain the backup battery 16 at the right state of charge; 3rd key-fob button enabled—if selected and a 3-button key-fob is programmed for this security system, the 3rd button will be able to perform its function (described below); Enable key-fob as a master—if selected, and the 3rd button is enabled, this button will enable/disable all locking and unlocking by RF keyfobs 26. This feature is designed for supervisors to be able to restrict access to cargo for the drivers at night, for example. Alternatively, the supervisor may use this button to program additional key-fobs 26. If this feature is disabled, and the 3rd button is still enabled, it will be used as a panic button (buzzer 17 on for 30 sec at the time); Enable 2nd door sensor—if selected, another door sensor is added. This sensor may indicate that the door may be slightly open, and the ECU 14 may sound a warning signal 17 to a person forcing the door to open; Enable temperature sensor—if selected, the temperature is measured by the temperature sensor 29, otherwise the temperature is set to 0 deg C.; Additionally, during a system setup process, the supplier selects more configuration 101 items: Enable one relay keypad—if selected, the ECU 14 will accept locking and unlocking commands on the same digital input; Enable diagnostic mode—if selected, diagnostic features are enabled; Enable watchdog timer—if selected, the ECU 14 is automatically reset, if the firmware is not executing properly; Enable 6 V battery—if selected, the ECU 14 accepts a 6 V backup battery 16 and adjusts all verification limits for that battery. The ECU 14 firmware is installed in the microcontroller 20 flash memory; however, it could be also installed in any EEPROM, EPROM, OTP (one time programmable), or RAM memory. The program could be written in “C”, or any other high level programming language or assembly language, in any way where the compilation, assembly, or any other process creates a string of hexadecimal or binary characters to be executed by a microcontroller 20 inside the ECU 14. In one embodiment, the main routine, executed by the processor may look like the one shown in FIG. 13. After powering up at 120, the ECU 14 initializes its configuration at 121, and clears a received packet buffer and a character counter at 122. At this time, it starts looking for characters—commands 60 from a PC or any other source at 123. If a character is received, it is verified if it is a valid start character 50 at 124. If it is the start character 50, the received packet buffer and the character counter are cleared at 125 and the program starts looking for the following command 60 characters. If the character received is not the start character at 124 and not the end character at 126, the program will load it to the received packet buffer and increment the character counter at 127. If the buffer is full, the next character will overwrite the oldest one received. Typically, the buffer size is 32 characters, but it could be different. Anytime the new start character 50 is detected at 124, the received packet buffer and the character counter are cleared at 125, and the program starts looking for valid command 60 characters again. If the valid end character 55 is received at 127, the string of previously received characters is treated as a command packet 60 (see FIG. 4). The checksum 54 is verified first at 128—if it is valid, and the command 60 is valid as well, it is processed at 130, otherwise the ECU 14 sends a response—a status packet 62 indicating a problem (either invalid checksum 129, or invalid command). If there are no characters coming (which is the case in most of the time), the microcontroller 20 performs other tasks, including: resetting the watchdog timer 131, making event log entries 132, processing 3rd key-fob button configuration changes 133, enabling the power saving mode 134, voltage and temperature measurements, and charging setup 135, and checking for problems in diagnostic mode 136. All timing related tasks, as well as processing lock and unlock requests, position corrections, and the 2nd door sensor are being done by a 40 msec interrupt routine (FIG. 14). All timers are incremented every 40 msec and compared to previously set values for a particular task to happen. When the comparison is successful, the task is executed. Described here is one of many ways of accomplishing timing related tasks. Examples of used herein timers include: a watchdog timer 140, system and remote timers 141, buzzer 17 and LED timers 142, door timers 143, a locking process timer 148, a unlocking process timer 149, a charger control timer 151, and relay output timers 152. Examples of processing tasks include: processing autolock and autorelock conditions 144, lock request 147, unlock request 145, emergency unlock request 146, 3rd key-fob button 150, 2nd door sensor 153, latch 9 position correction and forced unlock 154. Interrupt frequency may be different, and tasks could be designed to be time related, event related, or both ways. All commands and tasks are executed to perform efficiently the job required. The security system reliability and ability to perform its tasks, even when there is a failure detected in the system, is essential. The user needs to be able to rely on locking and unlocking ability all the time. One possible failure mode is when a memory 22 holding the system configuration 77, passwords, calibration offsets, and pointers to event log memory 22 gets corrupted. This memory 22 area, also called a header, is duplicated and also held in a different location. The second header (also called a redundant header) in normal operation is exactly the same as the first one. If a corruption happens to one header, the remaining one is used for repair. FIG. 15 describes the correction process. When the ECU 14 determines that a header may be corrupted, it generates a reset. Any time the reset happens, the correction process routine is executed to make sure both headers are correct. First, during initialization process, the 1st header is loaded to microcontroller's 20 RAM at 160. At 161 it is checked if it contains all hexadecimal FF's, an indication that this is a brand new ECU 14, never configured for operation. If the ECU 14 is determined to be new, both headers are loaded at 162 and the process ends. If it is not a new ECU 14, the 1st header's check sum is verified at 163. If it is correct, the second header is loaded at 164 and its check sum verified at 165. If any of them is found corrupted, it is fixed using the good header at 166 and 167. If both headers are corrupted at 168, the ECU 14 is still functional, however its functionality is limited and the user must use default passwords. In this case, events cannot be stored or retrieved. If the EEPROM memory 22 is functional, when different events happen, they are recorded into an event memory 22. In order to utilize the event memory 22 efficiently, there may be several different types of events. A different number of bytes may be used to store each event, depending on the implementation and data needed to be stored. In one embodiment shown in FIG. 16, each event uses 8 bytes, and there are 6 types of events. All events include an event type byte 170, 2 data bytes 171 and 172, and a time stamp (5 bytes) 173. Most of the events are type 1, which uses data bytes to record the ECU 14 status and the highest supply voltage—examples include: locking, unlocking, and programming RF key-fob memory. The events of type 2 include resets and configuration 77 changes, where both data bytes are used to store configuration. Type 3, 4, and 5 events are used during the initial setup and for diagnostics to record calibration offsets and number of security device 10 diagnostic cycles. A type 6 event is used to record the current temperature from the temperature sensor 29 and the backup battery 16 voltage. There is no limitation to number of types of events to use. In one embodiment, in order to access the ECU 14, the user must have a valid software license. Licenses for different ECU's are stored in a license file. FIG. 17 shows physical locations of the license file 180, serial number 182, and all passwords (Access 183, Administrator 184, User 181, Default Access 185 and Administrator 186). Each license file 180 contains encrypted pairs of each ECU's serial number 182 and an associated password, called the Access password 183. In addition, the license file 180 contains default information: a serial number 0 and a default Access password 185 assigned for the user by the supplier. The initially supplied license file 180 contains all serial numbers 182 of the security systems purchased by the user and one common Access password 183 for all of them. This Access password 183 could be the same as the default Access password 185. The user is also given an Administrator password 184 and a default Administrator password 186—most likely they are initially the same, but they could be different. The user installs a communication program 19 on his PC and also installs the license file 180. The supplier always encourages the user to change the passwords during the initial installation, in order to make sure that nobody else (even the supplier) has access to the user's security systems. The Administrator password 184 is needed to change the ECU 14 passwords. When the Access password 183 is changed, the license file 180 is automatically updated on the PC used to change the password. If any other PC needs to be used, the license file 180 from the first PC needs to be transferred to that PC, otherwise the new Access password 183 stored in the ECU 14 won't match the one included in the original license 180. Any time an EEPROM memory 22 gets corrupted, the default password 185 (or 186) is needed to access that ECU 14, and the functionality is limited. A default serial number is 0, because the real serial number 182 couldn't be read form the corrupted memory 22. There is also a User password 181 available to the user, needed to limit the access to the PC program 19 to the authorized people only. The Administrator password 184 could also be used to access the ECU 14 and the PC program 19, even if the User password 181 is not known to the administrator—he cannot change the User password 181 without knowing the old one, though. The only way to reset the User password 181 is to reinstall the PC program 19. When the Administrator password 184 is used to access the ECU 14, there is a data packet 61 returned to the PC, which includes the valid Access password 183 for that ECU 14. Then, the PC program 19 can use the obtained serial number 182 and Access password 183 to verify software license 180. If the EEPROM memory 22 is corrupted, the ECU 14 status packet 62 contains this information in the status byte 59. At this time, the PC program 19 needs to use default passwords 185 (or 186) and the serial number 0 for any ECU 14 access. The corrupted memory 22 cannot be repaired or reset in the field. The ECU 14 needs to be sent for service to the supplier. FIG. 18 shows the process used to validate User 181 and Administrator 184 passwords, if diagnostics is not enabled. The user enters a password to the PC. The PC program 19 verifies if this is a valid User password at 190. If the User password 181 is verified, the user can access the PC program 19 setup only at 191. In order to gain access to the ECU 14, the user has to “initialize” 75 the connection at 192. At this point, the software license is verified at 193 by comparing the ECU 14 serial number 182 and Access password 183 with the pairs stored in the license file 180, and the user can access the ECU 14 at 194. If additional features are needed, like changing passwords for example, the user is prompted at 195 to enter the Administrator password 184, otherwise the additional feature will be denied. If the user enters the PC program 19 with a password other than the User password 181, the PC program 19 verifies if this is a valid the Administrator password 184. If the password is verified at 196, and the Access password 183 and the serial number 182 are retrieved from the ECU 14 to verify the software license 180 compliance at 197. If everything is fine, the user is given the administrator rights at 198, otherwise only the PC program 19 setup rights 191 are available. FIG. 19 shows all available choices to users with different passwords verified in the system. If for any reason the internal EEPROM memory 22 is corrupted, the user must use default passwords 185 or 186 and his access is limited to what the default software license allows. If diagnostics mode is enabled (FIG. 20), it is assumed that the ECU 14 is still at the supplier and it is being setup or diagnosed for problems. The user enters a password at 200. The PC program 19 verifies if this is a valid User password 181 at 201. If the User password 181 is verified, the user can access the PC program 19 setup only at 202. In order to gain access to the ECU 14, the user has to “initialize” 75 the connection at 203. At this point, the software license is verified at 204 by comparing the ECU 14 serial number 182 and Access password 183 with the pairs stored in the license file 180, and the user can access the ECU 14 at 205. If additional features are needed, like changing passwords, or running diagnostics for example, the user is prompted at 206 to enter the Administrator password 184, otherwise the additional feature will be denied. If the user enters the PC program 19 with a password other than the User password 181, the PC program verifies if this is a valid the Administrator password 184. If the password is verified at 207, the Access password 183 and the serial number 182 are still retrieved from the ECU 14, but the software license is not needed in this mode. The user is given the full administrator rights at 208. FIG. 21 shows all available choices to users with different passwords verified in the system. If for any reason the internal EEPROM memory 22 is corrupted, the user must use default passwords 185 or 186 and his access is limited, however, the administrator 186 can attempt to repair the corrupted memory 22, by writing initial default values to it, stored in the microcontroller 20 program memory. If a brand new ECU 14 is connected to the PC program 19, the communication is not possible, because the firmware is not programmed yet to the microcontroller 20 flash memory. Therefore, in this particular case, the Administrator password 184 cannot be verified. The User password 181 is needed to start the PC program 19 and verify if the ECU 14 is responding to commands at 209. If there is no PC-ECU communication, the program 19 could load the ECU 14 firmware at 210. When the firmware is programmed and communication established at 203, either a generic license (S/N 0, default Access password 185) is verified at 204 and the user finishes its tasks in this mode, or he is prompted for the default Administrator password 186 at 206 to continue diagnostics and/or setup the passwords 183 or 184, and/or the serial number 182, and/or create the user software license file 180. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants' contribution. | <SOH> BACKGROUND <EOH>A need exists for a security system that employs an electronic controller used specifically to control various devices and interface with the controlled devices using software unique to the security process employed by those devices, so that it can be used for both roll-down doors and swing-out doors. A need also exists for a security system that stores a number of information records, such as records concerning the unlocking, locking, opening or closing of the door, including the date, time, air temperature, and/or geographical location of such event. The records need to be updated in such a way that the new ones replace the oldest as soon as the maximum number of records allowed is reached. Furthermore, a need exists for an electronic control system that communicates with a unique protocol and provides a customer a secure two-way connection using a remote terminal, such as a personal computer (PC). A need exists for a PC software program to communicate with the electronic controller, update its software, adjust features, enable/disable and program input devices, calibrate, diagnose problems, and retrieve information records. The supplier should be able to control access by issuing software licenses for each electronic control system. The customer should be able to protect access to the security system by setting and maintaining software passwords. A need further exists for an electronic control system that operates on its own, without external power connected, for a maximum possible time duration, and to maintain its power source by charging it when the outside power is available and controlling which power source is used by the system. | <SOH> SUMMARY <EOH>The disclosed apparatus and methods avoid some of the disadvantages of prior devices that do not employ an electronic control system, and add new features. In an embodiment of the invention, a security system is provided for a cargo container having a door. The security system comprises an electronic control unit capable of performing at least one activity and monitoring at least one function and being operably communicable with a remote computer terminal. A first software control program is provided within the electronic control unit to monitor the activity and the function. A second software control program is provided within the remote computer terminal and is capable of retrieving the activity and the function from the first software control program. In an embodiment of the invention, a method is provided for monitoring and recording a condition of a cargo container having a lockable door using a cargo security system. The method comprises an electronic control unit capable of monitoring at least one function and creating an alarm condition; a sensor capable of measuring a parameter and being operably coupled to the electronic control unit; and a remote terminal computer capable of operably communicating with electronic control unit. The method comprises the steps of disposing the electronic control unit within the cargo container; comparing the parameter with a table having parameter limits; and creating an alarm condition if the parameter does not comply with the parameter limits. In an embodiment of the invention, a method is provided for securing from the inside the cargo of a trailer having a container and cargo door accessible from the outside for closing the container and being movable from an open position to a closed position. The method comprises providing a security device containing a latch with a screw on the inside of the container, and a linked electronic control system. The electronic control system may be used to operate and control turning of the screw in a direction, thereby moving the latch between unlocked and locked positions. In one embodiment of the invention, the method comprises providing a control software program that controls the movement of the latch between the unlocked and the locked positions. The control software program may be located in a nonvolatile memory of the electronic controller or other memory retention device. A signal generation device may also be provided, which is capable of sending lock, unlock, or other control signals to the controller. The software determines when one of the control signals is sent from the signal generation device to the controller. For example, the unlock control signal may indicate that the security device should be in the unlocked position, but the lock control signal indicates that the security device is in the locked position. In order to maximize precision and repeatability of the security system to be able to stop at the same position at any voltage and temperature conditions, a short reverse control signal may also be applied after the main control signal is complete. In one embodiment, the method also includes storing in memory control data indicative of the most recent control signals sent from the signal generation device to the controller. In one embodiment, several different sensors could be coupled to the controller. The method includes the control software to process the sensor inputs. The security device position sensors indicate whether the security device is in the locked or unlocked position. One or more door sensors could be provided, which are also coupled to the controller. The method includes sensing, with the door sensor, whether the cargo door is in the open or closed position. A door position signal, indicative of whether the door is in the open or closed position, is sent to the controller. The method includes moving the latch from its unlocked position to its locked position, if the signal generation device sends the lock control signal to the controller, the security device position signal indicates that the latch is in the unlocked position, and the door position indicates that the door is in the closed position. In one embodiment, a memory is coupled to the controller, with the controller activity being sent through the software which allows the memory to be capable of storing control data indicative of the most recent control signal sent from the signal generation device to the controller. A more detailed explanation of the invention is provided in the following description and claims, and is illustrated in the accompanying drawings. | 20040212 | 20060815 | 20050818 | 78772.0 | 1 | LIEU, JULIE BICHNGOC | ELECTRONIC CONTROL SYSTEM USED IN SECURITY SYSTEM FOR CARGO TRAILERS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,777,915 | ACCEPTED | Desynchronized fingerprinting method and system for digital multimedia data | A desynchronized fingerprinting method and system for identifying collaborators in the making of illegal copies of digital multimedia products. The desynchronized fingerprinting system and method can be used for both audio and video applications. The method and system include an embedding feature and a detection and extraction feature. A different and unique key is assigned to each buyer of a copy of the digital data. The embedding feature includes applying a pseudo-random transformation to selected embedding regions. The key for the pseudo-random transform is user-specific. These regions are chosen by using a secure multimedia hash function. The detection and extraction feature includes a brute-force search in the key space of the buyers. If one of the keys is likely enough, then it can be said that that user was been involved in the production of an illegal copy. | 1. A computer-implemented method for desynchronized fingerprinting of digital data, comprising: selecting embedding regions in the digital data for embedding fingerprints; selecting desynchronization regions in the digital data for desynchronizing copies of the digital data from each other; performing random desynchronization for each of the desynchronization regions to randomly vary a width of each of the desynchronization regions; and embedding fingerprints at each of the embedding regions to produce desynchronized fingerprinted digital data. 2. The computer-implemented method of claim 1, further comprising randomly selecting the embedding regions and desynchronization regions. 3. The computer-implemented method of claim 1, further comprising using a master key and a hash function to randomly select the embedding regions. 4. The computer-implemented method of claim 3, further comprising finding and storing hash values for each of the embedding regions. 5. The computer-implemented method of claim 1, further comprising using a master key to randomly select the desynchronization regions. 6. The computer-implemented method of claim 1, wherein performing random desynchronization for each of the desynchronization regions further comprises using a master key to randomly compute a width for each of the desynchronization regions such that the width varies between the copies of the digital data. 7. The computer-implemented method of claim 1, further comprising generating multiple copies of the digital data and fingerprinting each copy. 8. The computer-implemented method of claim 1, further comprising embedding a unique secret key at each of the embedding regions. 9. A computer-readable medium having computer-executable instructions for performing the computer-implemented method recited in claim 1. 10. A computer-readable medium having computer-executable instructions for desynchronized fingerprinting of digital multimedia data, comprising: generating multiple copies of the digital multimedia data; randomly selecting embedding regions within each copy; randomly selecting desynchronization regions within each copy; computing a random width for each of the desynchronization regions such that a width of each of the desynchronization regions varies between the multiple copies; and embedding information at each of the embedding regions to produce desynchronized fingerprinted copies of the digital multimedia data. 11. The computer-readable medium of claim 10, wherein randomly selecting embedding regions further comprises using a pseudo-random operator and a master key. 12. The computer-readable medium of claim 11, wherein the pseudo-random operator is a hash function. 13. The computer-readable medium of claim 10, further comprising finding and storing hash values for each of the embedding regions. 14. The computer-readable medium of claim 10, wherein randomly selecting desynchronization regions further comprises using a master key. 15. The computer-readable medium of claim 10, wherein computing a random width for each of the desynchronization regions further comprises using a master key for computing a random width and changing the width accordingly. 16. The computer-readable medium of claim 10, wherein embedding information at each of the embedding regions further comprises embedding unique copy information and a unique secret key. 17. The computer-readable medium of claim 16, further comprising cataloging the unique copy information such that each of the multiple copies is associated with a specific entity. 18. The computer-readable medium of claim 16, further comprising associating the unique copy information with the unique secret key. 19. The computer-readable medium of claim 18, wherein the unique information is number of a specific one of the multiple copies. 20. The computer-readable medium of claim 17, further comprising: extracting the unique copy information from an illegal copy of the digital multimedia data; and determining from the unique copy information the identities of entities involved in the production of the illegal copy. 21. A process for detecting and extracting fingerprints from digital data, comprising: determining embedding regions within the digital data; using a plurality of secret keys to perform watermark detection on each of the embedding regions; and detecting identification information associated with a secret key. 22. The process as set forth in claim 21, further comprising computing multiple hash values of the digital data and determining the embedding regions using the multiple hash values. 23. The process as set forth in claim 21, further comprising extracting collaborator information from the identification information. 24. The process as set forth in claim 23, further comprising constructing a list of collaborators from the collaborator information representing a list of persons who collaborated in producing the digital data. 25. One or more computer-readable media having computer-readable instructions thereon which, when executed by one or more processors, cause the one or more processors to implement the method of claim 21. 26. A desynchronized fingerprinting system for desynchronized fingerprinting of copies of an original digital multimedia product, comprising: an embedding module for using a random desynchronization process and a plurality of secret keys to embedding fingerprints in each copy of the product; and a detection and extraction module for detecting the embedded fingerprints using the plurality of secret keys and extracting collaborator information from the fingerprints to identify collaborators in the production of an illegal copy of the digital multimedia product. 27. The desynchronized fingerprinting system as set forth in claim 26, wherein the embedding module further comprises an embedding region selector for randomly selecting embedding regions in each copy of the product in which to embed fingerprints. 28. The desynchronized fingerprinting system as set forth in claim 26, wherein the embedding module further comprises a desynchronization region selector for randomly selecting desynchronization regions in which to apply intentional desynchronization. 29. The desynchronized fingerprinting system as set forth in claim 28, wherein the embedding module further comprises a random desynchronization module for randomly selecting and applying a width of the desynchronization regions such that each width of a desynchronization region is different between each copy of the product. | TECHNICAL FIELD The present invention relates in general to multimedia fingerprinting and more particularly to a secure fingerprinting system and method for identifying collaborators in the making of illegal copies of digital multimedia products. BACKGROUND OF THE INVENTION The illegal copying of digital multimedia data products (such as movies and audio recordings) is a widespread problem. The problem only seems to be growing, despite technical advancements in copy protection and mounting efforts to enforce intellectual property rights. This infringement of intellectual property rights can cause great financial harm to the owner. The upward trend in illegal copying seems to be tied to the expanding use of digital media and equipment for storing and distributing digital multimedia data. The enormous growth of Internet technology and digitally stored data has made it possible to easily and inexpensively produce high-quality identical copies of an original. In addition, it is possible to make the copies available to the entire Internet community. This process has become further easier with the usage of peer-to-peer (P2P) networks. With the increasing availability of copying devices and increased bandwidth for digital data, the need to restrain illegal redistribution of digital multimedia data (such as images,. videos and music) has become an important issue. One way to deter illegal copying is to increase the risk of being caught after the piracy has occurred. Storing a unique, invisible mark in each copy (in other words, embedding the mark in the perceptual content of the digital media signal securely and robustly) is a way to increase that risk. In this manner, if an illegal copy is found somewhere, it is possible to find the owner of the copy and to take legal action. This type of enforcement scheme is called fingerprinting (also known as “mark embedding” for forensics in some communities). The idea of fingerprinting is to uniquely mark each copy. This makes each copy bit-wise different from every other copy, and yet otherwise perceptually approximately the same. In this way, it is possible to distinguish between all legal copies. The marking can be used to identify the copy, and thereby the user if his identity is linked to the fingerprint in some way. For example, if the fingerprinted copies are only distributed to those persons who identify themselves, it may be possible, if an illegal copy is found, to identify the owner of the legal copy from which the illegal copy was made. By way of example, assume the owner of a movie on digital video disk (DVD) makes copies of the movie for sale. Each of the copies is fingerprinted. The owner only sells a copy to a user after having individually and uniquely marked each user's copy with a fingerprint and associated each fingerprint uniquely with a buyer. Later, a number of buyers, called pirates, collude in creating an illegal copy that they redistribute (in this situation the pirates are also called colluders). The owner of the movie can analyze an illegal copy and attempt to find out which of the buyers took part in the creation of the illegal copy. The fingerprinting technique includes inserting fingerprints in each copy of a digital product using a watermarking (also termed “mark embedding”) scheme. A watermarking scheme imperceptibly embeds the fingerprint in the perceptual content in a way that it can only be recovered using a secure key. It should be noted that this type of scheme is completely different from conventional Digital Rights Management (DRM) techniques for content protection. There are two important differences between watermarks (for screening purposes to prevent illegal copying or recording) and fingerprints (for forensics purposes to trace the leakage). First, while in watermarking the hidden message (mark) is the same for all buyers (and this mark often represents the identity of the content owner), in fingerprinting the mark depends on the buyer's identity. Second, buyer collusion is not an issue in watermarking (the marked copies for a single content being the same for all buyers). However, in fingerprinting the mark is different for every buyer, and it makes sense for a collusion of buyers to collude by comparing their copies and try to locate and delete some mark bits. Thus, in a collusion attack on fingerprinted digital products, a group of dishonest users colludes to create an illegal copy that hides their identities by putting together different parts of their copies. The attack seeks to eliminate the hidden embedded fingerprints. One problem with current fingerprinting techniques is that they are limited in the number of collaborators that can be identified. For example, several traditional current fingerprinting techniques can only identify between four and eight collaborators. Some newer fingerprinting techniques use fingerprinting codes to enable the detection of an order of magnitude better that traditional fingerprinting techniques. However, there are frequently a large number of collaborators involved in the production of an illegal copy. This means that current fingerprinting techniques cannot accurately detect and identify collaborators greater than one-hundred. This severely limits the deterrent effect of fingerprinting, since collaborators know that all they have to do is collaborate with a large number of other copy owners to avoid detection. Another problem with current fingerprinting techniques is that they are susceptible to estimation attacks. Estimation attacks occur when attackers take all of the frames of the scene and compute an average of all the frames, thereby forming an estimate of the original unmarked content. Alternatively, different techniques may also be used to estimate the fingerprint of each client using the inherent redundancy that is present in the media signal. This tends to greatly weaken or eliminate all of the fingerprints. Therefore, what is needed is a fingerprinting system and method that is capable of accurately identifying at least an order of magnitude greater number of collaborators than current fingerprinting techniques. What is also needed is a fingerprinting system and method that is (cryptographically) secure and resistant to estimation attacks. SUMMARY OF THE INVENTION The invention disclosed herein includes a desynchronized fingerprinting method and system that is resistant to attacks and that can identify a large number of collaborators without the use of fingerprinting codes. In particular, the desynchronized fingerprinting method and system disclosed herein is capable of identifying more than an order of magnitude more collaborators than current fingerprinting techniques. The desynchronized fingerprinting system and method can be used for any type of multimedia, particularly audio and video applications. In general, a different key is assigned to each user. The embedding feature includes applying a pseudo-random transformation to chosen regions. The key for the pseudo-random transform is user-specific. These regions are chosen via a secure multimedia hash function. The detection and extraction feature includes a brute-force search in the key space of the users. If one of the keys is “likely” enough, it is declared that the user has been involved in the production of an illegal copy. The desynchronized fingerprinting method includes a desynchronized embedding process and a detection and extraction process. The desynchronized embedding process includes generating copies of an original multimedia product (where each copy is a pseudo-random desynchronized version of the original) and randomly selecting both desynchronization and embedding regions in which to embed fingerprints. The pseudo-random “intentional” desynchronization prior to actual mark embedding ensures that it is difficult for colluders to find a good estimate of the unmarked original signal (such as, for example, by using averaging-type attacks). This is because it is necessary for the colluders to “align” their copies with respect to each other for collusion, and this becomes more difficult as the number of colluders increases (assuming the total computation power is limited). A random desychronization process includes mapping the width of each desynchronization region to a pseudo-randomly determined quantity such that they vary between copies for different clients. A master key is used in the random desychronization process. Similarly, a master key and a hash function are used to randomly select the embedding regions. Unique copy information and secret keys then are embedded in the embedding regions. In general, embedding regions and desynchronization regions need not be the same, though they can overlap. The detection and extraction process includes obtaining an illegal copy of the original digital multimedia product. Hash values are computed for the illegal copy, and these hash values are used to determine the embedding regions by comparing them to the hash values of the embedding regions of the original content. In essence, robust perceptual hash functions are used to “lock” to the embedding locations at the receiver. Watermark detection then is performed on each of the embedding regions using each one of the secret keys. Identification information is detected and collaborator information is extracted to construct a list of collaborators. These collaborators represent persons who collaborated on the production of the illegal copy. BRIEF DESCRIPTION OF THE DRAWINGS The present invention can be further understood by reference to the following description and attached drawings that illustrate aspects of the invention. Other features and advantages will be apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the present invention. Referring now to the drawings in which like reference numbers represent corresponding parts throughout: FIG. 1 is a block diagram illustrating an exemplary implementation of the desynchronized fingerprinting system and method disclosed herein. FIG. 2 is a general flow diagram illustrating the general operation of the desynchronized fingerprinting system shown in FIG. 1. FIG. 3 is a general flow diagram illustrating the operation of the desynchronized embedding process of the desynchronized fingerprinting method shown in FIG. 2. FIG. 4 is a detailed flow diagram illustrating in further detail the operation of the desynchronized embedding process shown in FIG. 3. FIG. 5 is a general flow diagram illustrating the operation of the detection and extraction process of the desynchronized fingerprinting method shown in FIG. 2. FIG. 6 illustrates an example of a suitable computing system environment in which the desynchronized fingerprinting system and method shown in FIG. 1 may be implemented. FIG. 7 is a block diagram illustrating the details of the desynchronized fingerprinting system shown in FIG. 1. FIG. 8 is a block diagram illustrating the details of the embedding module shown in FIG. 7. FIG. 9 is a block diagram illustrating the details of the detection and extraction module shown in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION In the following description of the invention, reference is made to the accompanying drawings, which form a part thereof, and in which is shown by way of illustration a specific example whereby the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. I. Introduction The illegal copying and distribution of digital multimedia data has become a widespread problem, resulting in the loss of revenue for the owner of the intellectual property. One way to increase the risk of being caught is to use fingerprinting techniques that uniquely identify a copy of a product containing the digital multimedia data with a buyer. However, current fingerprinting techniques are severely limited on the number of collaborators that can be identified. In addition, these techniques typically use fingerprinting codes, which can be difficult to implement. Moreover, current fingerprinting techniques are vulnerable to estimation attacks, which can virtually eliminate the fingerprints. The desynchronized fingerprinting method and system described herein is capable of identifying at least an order of magnitude greater number of collaborators than current techniques. Moreover, the method and system achieves this without the use of fingerprinting codes. Although codes may be used with the desynchronized fingerprinting method and system, they are not required. In addition, the desynchronized fingerprinting method and system is made resistant to estimation attacks through the use of a novel random desynchronization process that randomly varies the width of randomly-selected desynchronization regions. Then, fingerprints are embedded for each copy of the digital multimedia data in embedding regions, which may be the same as or different from desynchronization regions. By increasing the number of collaborators that can be identified and by making the technique resistant to estimation attacks, the desynchronized fingerprinting method and system serves as a strong deterrent to illegal copying. II. General Overview FIG. 1 is a block diagram illustrating an exemplary implementation of the desynchronized fingerprinting system and method disclosed herein. It should be noted that FIG. 1 is merely one of several ways in which the desynchronized fingerprinting system and method may implemented and used. The desynchronized fingerprinting system and method operates on digital multimedia data (such as images, video, or audio). In general, there are two parts to the desynchronized fingerprinting system and method. The first part is using the desynchronized fingerprinting system and method to embed unique information within each copy of a digital multimedia product (such as a movie or an audio recording). This unique information is cataloged so that a copy of the product is associated with a specific person (such as the buyer of the product copy). The second part involves analyzing an illegal copy of the product (such as, for example, forensics analysis) to determine which of persons collaborated to produce the illegal copy. In the exemplary implementation shown in FIG. 1, the digital multimedia product is movie. More specifically, as shown in FIG. 1, the desynchronized fingerprinting system and method 100 is used to process a master copy of a movie 105. As described in detail below, the desynchronized fingerprinting system and method 100 uses a master key 110 and a plurality of secret keys 115. In this exemplary implementation the number of secret keys is N. After processing, the output of the desynchronized fingerprinting system and method 100 is N copies of the movie 105. In particular, the desynchronized fingerprinting system and method 100 produces a fingerprinted movie copy (1) 120, a fingerprinted movie copy (2) 125, a fingerprinted movie copy (3) 130, and so forth, up to a fingerprinted movie copy (N) 135. Each of the fingerprinted movie copies has a corresponding one of the secret keys 115. The secret key associated with the fingerprinted movie copy allows the holder of the key to access the unique information contained within the movie copy. Each of the fingerprinted movie copies then is distributed in some manner. Typically, distribution includes offering for sale. However, other types of distribution are possible, such as distribution for some other purpose to clients, such as reviewing, evaluation, and so forth. In the exemplary implementation shown in FIG. 1, the distribution is by someone purchasing a fingerprinted copy of the movie. In particular a first buyer (B(1)) 140 buys fingerprinted movie copy (1) 120, a second buyer (B(2)) 145 buys fingerprinted movie copy (2) 125, a third buyer (B(3)) 150 buys fingerprinted movie copy (3) 130, and so forth such that an Nth buyer (B(N)) 155 buys fingerprinted movie copy (N) 135. A record is kept of each of the buyers and the copy number of the movie they bought. An illegal copy of the movie 160 is typically made by a collaboration of several of the buyers, as shown by the arrow 165 in FIG. 1. However, the identity of the buyers who participated in the collaboration is unknown at this point. The desynchronized fingerprinting system and method 100 is used to process the illegal movie copy 160 and identify the collaborators. The illegal movie copy 160 is processed by the desynchronized fingerprinting system and method 100 by trying each of the secret keys 115. If a secret key 115 opens a portion of information embedded within the illegal movie copy 160, then the buyer associated with that key is said to be a collaborator involved in the making of the illegal movie copy 160. In this exemplary implementation shown in FIG. 1, buyers B(6) 165, B(7) 170 and B(9) 175 were identified as being involved in the making of the illegal movie copy 160. Appropriate legal action then can be taken to deter others from collaborating in the making of illegal copies (such as incarcerating the guilty parties 180). It should be noted that the desynchronized fingerprinting system and method 100 can identify a much greater number of collaborators than the three shown. In fact, one strength of the desynchronized fingerprinting system and method 100 is that it can identify a very large number of collaborators. However, for the sake of simplicity, only three are shown in this exemplary implementation. III. Operational Overview The operation of the desynchronized fingerprinting system and method 100 shown in FIG. 1 now will be discussed. FIG. 2 is a general flow diagram illustrating the general operation of the desynchronized fingerprinting system shown in FIG. 1. The desynchronized fingerprinting method begins by obtaining an original digital multimedia product (box 200) and making copies (box 210). A different and unique secret key is assigned for each copy along with unique information associated with that key (box 220). For example, the unique information may be a number of the copy. Each copy then is fingerprinted by embedding the secret key and the associated unique information by using a desynchronized embedding process (box 230). The resulting desynchronized fingerprinted copies then are distributed (box 240). For example, the copies may be sold to the general public or available for rental. Some of the holders of the copies may later collaborate to produce an illegal copy. For example, a small portion of each of the collaborators' copies may be used to produce a single illegal copy. This typically would involve a large number of collaborators. In general, the idea is that the larger number of collaborators the less likely that each of them will be identified as a collaborator. The illegal copy is obtained (box 250) and is processed by the desynchronized fingerprinting method. The method detects and extracts the embedded fingerprints in the illegal copy (box 260). The embedded fingerprints are detected and extracted using a desynchronized fingerprinting detection and extraction process and secret keys. The desynchronized fingerprinting detection and extraction process determines and identifies the collaborators that participated in the making of the illegal copy. IV. Operational Details FIG. 3 is a general flow diagram illustrating the operation of the desynchronized embedding process of the desynchronized fingerprinting method shown in FIG. 2. In general, the desynchronized embedding process performs two functions. First, the process embeds unique information into a copy of a multimedia product at random embedding locations. Second, the process desynchronizes different copies from each other randomly (using the master key) at different desynchronization locations. In one embodiment, the embedding regions and the desynchronization regions are at the same locations. Alternatively, the embedding regions may be at the same locations as the desynchronization regions. Referring to FIG. 3, the desynchronized embedding process first obtains a copy of the multimedia product (box 300). Next, embedding regions and desynchronization regions of the multimedia product copy are selected randomly (box 310). An embedding region is a location in the multimedia product copy where the fingerprint is to be embedded. A desynchronization region is a location where random width changes are applied. These random width changes are different for each user with high probability. If the multimedia product is a movie, preferably, the embedding region is not a single frame or scene. Alternatively, the embedding region can be a single scene containing a number of frames. If the multimedia product is an audio recording, the embedding region can be audio clip or audio fragment containing a portion of the audio recording. Similar arguments also apply to the desynchronization regions. Typically, the audio clip, where a fingerprint is to be embedded, is much shorter than the entire recording. The number of embedding and desynchronization regions may be selected randomly or may be selected by a user. Furthermore, the perceptual characteristics of the media content are also significant in this choice. Typically, it is not desirable to embed marks in a region where there is low activity (or regions having little entropy) because of perceptual and security reasons. Naturally, this affects the choice of the number of selected regions. Even if there are a large number of high-activity regions (suitable for mark embedding in terms of security and robustness), the selection of the number of embedding regions is a tradeoff between confidence and expense. A greater number of embedding regions means a larger number of fingerprints and a higher confidence, but a greater expense. On the other hand, a smaller number of embedding regions means a smaller number of fingerprints and a smaller confidence, and a greater number of collaborators that may be missed. However, it also means less expense in detecting and extracting the fingerprints Random desynchronization is performed for each desynchronization region (box 320). Random desynchronization is a novel feature of the desynchronized fingerprinting method that is used to make the desynchronized fingerprinting method secure from estimation attacks. One problem in fingerprinting is the class of collusion attacks that arise if there are numerous copies of the product and if the same scene is fingerprinted with numerous keys. As an example, an attacker can take all of the frames of the scene and compute an average of all the frames (known as an estimation attack, since the attacker is forming an estimate of the original unmarked content). Alternatively, an attacker can select and paste different portions of the scene from different copies, thereby forming a new copy (known as copy and paste attacks). These types of attacks (assuming they are executed properly) generally will kill all the fingerprints. To counter these types of attacks (such as estimation attacks, copy and paste attacks, and so forth), the desynchronized fingerprinting method uses random desynchronization to randomly vary the number of frames that a scene contains. Note that, in order to be able to apply a collusion attack, one important prerequisite is that all client copies should be “aligned”. After applying pseudo-random desynchronization, the number of frames a scene contains varies between copies of the movie. These numbers are chosen pseudo-randomly for each user and hence they are different for each user with high probability. This technique is applied to randomly-chosen regions, called desynchronization regions. The desynchronization technique, which is unique to the desynchronized fingerprinting method, mitigates the probability of an attacker erasing the fingerprints. Thus, copy 1 of the first scene of the movie may contain 28 frames, while copy 2 may contain 32 frames. This severely limits the ability of a potential attacker to apply collusion attacks. This is because the method makes it difficult to synchronize all of the copies and average them. Moreover, more copies means that it is more difficult to synchronize the copies and put them together to launch an estimation attack. Next, information is embedded at each of the embedding regions (box 330). In general, desynchronization regions and embedding regions need not be the same, but they can possibly overlap. The embedded information may be, for example, the number of the copy of the multimedia product. Finally, the desynchronized fingerprinted copy of the multimedia product is output (box 340). FIG. 4 is a detailed flow diagram illustrating in further detail the operation of the desynchronized embedding process shown in FIG. 3. A copy of the multimedia product is created (box 400). Next, a master key is used to randomly select the desynchronization regions within the multimedia product copy (box 410). Also, the master key and a hash function are used to randomly select the embedding regions (box 420). Hash values then are found and stored for each of the embedding regions (box 430). The random desynchronization process includes randomly varying the width of the desynchronization regions so as to desynchronize product copies. This random desynchronization process includes using the master key to randomly compute a new width for each of the desynchronization regions and changing the width accordingly (box 440). Unique copy information is embedded at each of the embedding regions (box 450). In addition, a secret and unique key is embedded at each of the embedding regions (box 460). Finally, the desynchronized fingerprinted product copy is output (box 470). FIG. 5 is a general flow diagram illustrating the operation of the detection and extraction process of the desynchronized fingerprinting method shown in FIG. 2. The process begins by obtaining an illegal copy of the original multimedia product (box 500). Next, hash values of the illegal copy are computed (box 510). The embedding regions then are determined from the computed hash values (box 520). A watermark detection process then is performed on each of the embedding regions for each of the secret keys (box 530). Thus, for each of the embedding regions each of the secret keys is tried. This alleviates the need for fingerprinting codes or other types of codes. At the expense of computation, much larger collusions than are currently available can be traced using this process. Alternatively, a random number of keys may be selected to be tried to the illegal copy. This lessens the computation expense but runs the risk that certain collaborators may be missed. Identification information associated with a particular secret key then is detected (box 540). This identification may be, for example, the name and address of a buyer of the product copy. Once the identification information is detected, it is extracted and associated with a collaborator to obtain collaborator information (box 550). A list of collaborators then can be constructed (box 560). V. Exemplary Operating Environment The desynchronized fingerprinting system and method 100 are designed to operate in a computing environment and on a computing device. The computing environment in which the desynchronized fingerprinting system and method 100 operates will now be discussed. The following discussion is intended to provide a brief, general description of a suitable computing environment in which the desynchronized fingerprinting system and method 100 may be implemented. FIG. 6 illustrates an example of a suitable computing system environment in which the desynchronized fingerprinting system and method 100 shown in FIG. 1 may be implemented. The computing system environment 600 is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing environment 600 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment 600. The desynchronized fingerprinting system and method 100 is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable for use with the background color estimation system and method include, but are not limited to, personal computers, server computers, hand-held, laptop or mobile computer or communications devices such as cell phones and PDA's, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like. The desynchronized fingerprinting system and method 100 may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. The desynchronized fingerprinting system and method 100 may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices. With reference to FIG. 6, an exemplary system for implementing the desynchronized fingerprinting system and method 100 includes a general-purpose computing device in the form of a computer 610. Components of the computer 610 may include, but are not limited to, a processing unit 620, a system memory 630, and a system bus 621 that couples various system components including the system memory to the processing unit 620. The system bus 621 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus. The computer 610 typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by the computer 610 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computer 610. Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. Note that the term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer readable media. The system memory 630 includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) 631 and random access memory (RAM) 632. A basic input/output system 633 (BIOS), containing the basic routines that help to transfer information between elements within the computer 610, such as during start-up, is typically stored in ROM 631. RAM 632 typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 620. By way of example, and not limitation, FIG. 6 illustrates operating system 634, application programs 635, other program modules 636, and program data 637. The computer 610 may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only, FIG. 6 illustrates a hard disk drive 641 that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive 651 that reads from or writes to a removable, nonvolatile magnetic disk 652, and an optical disk drive 655 that reads from or writes to a removable, nonvolatile optical disk 656 such as a CD ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive 641 is typically connected to the system bus 621 through a non-removable memory interface such as interface 640, and magnetic disk drive 651 and optical disk drive 655 are typically connected to the system bus 621 by a removable memory interface, such as interface 650. The drives and their associated computer storage media discussed above and illustrated in FIG. 6, provide storage of computer readable instructions, data structures, program modules and other data for the computer 610. In FIG. 6, for example, hard disk drive 641 is illustrated as storing operating system 644, application programs 645, other program modules 646, and program data 647. Note that these components can either be the same as or different from operating system 634, application programs 635, other program modules 636, and program data 637. Operating system 644, application programs 645, other program modules 646, and program data 647 are given different numbers here to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer 610 through input devices such as a keyboard 662 and pointing device 661, commonly referred to as a mouse, trackball or touch pad. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, radio receiver, or a television or broadcast video receiver, or the like. These and other input devices are often connected to the processing unit 620 through a user input interface 660 that is coupled to the system bus 621, but may be connected by other interface and bus structures, such as, for example, a parallel port, game port or a universal serial bus (USB). A monitor 691 or other type of display device is also connected to the system bus 621 via an interface, such as a video interface 690. In addition to the monitor, computers may also include other peripheral output devices such as speakers 697 and printer 696, which may be connected through an output peripheral interface 695. The computer 610 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 680. The remote computer 680 may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 610, although only a memory storage device 681 has been illustrated in FIG. 6. The logical connections depicted in FIG. 6 include a local area network (LAN) 671 and a wide area network (WAN) 673, but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet. When used in a LAN networking environment, the computer 610 is connected to the LAN 671 through a network interface or adapter 670. When used in a WAN networking environment, the computer 610 typically includes a modem 672 or other means for establishing communications over the WAN 673, such as the Internet. The modem 672, which may be internal or external, may be connected to the system bus 621 via the user input interface 660, or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer 610, or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation, FIG. 6 illustrates remote application programs 685 as residing on memory device 681. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. VI. System Components The desynchronized fingerprinting system 100 shown in FIG. 1 includes a number of program modules that allow the system 100 to uniquely mark copies of a multimedia product and later identify collaborators involved in the production of an illegal copy of the product. In general, the system 100 includes an embedding feature and a detection and extraction feature. The program modules for each of these features now will be discussed. FIG. 7 is a block diagram illustrating the details of the desynchronized fingerprinting system 100 shown in FIG. 1. The system 100 essentially has two functions, as illustrated by the dashed line: (a) a desynchronized embedding of fingerprints; and (b) detection and extraction of fingerprints. In particular, for the embedding function, an original digital multimedia product 700 (such as a movie or audio recording) is input into the desynchronized fingerprinting system 100. An embedding module 710, which is located in the desynchronized fingerprinting system 100, is used to process the product 100 such that desynchronized fingerprinted copies 720 of the product 700 are created. For the detection and extraction function, an illegal copy 730 of the product 700 is obtained and analyzed by the desynchronized fingerprinting system 100. A detection and extraction module 740, which is located in the desynchronized fingerprinting system 100, is used to detect embedded fingerprints and extract information in the fingerprints. This information allows collaborators that had involvement in the production of the illegal copy 730 to be uniquely identified. The desynchronized fingerprinting system 100 then can create a list of collaborators 750. FIG. 8 is a block diagram illustrating the details of the embedding module 710 shown in FIG. 7. In particular, the embedding module 710 includes a copy module 800, an embedding region 810, a desynchronization region selector 820, a random desynchronization module 830, and an embedding module 840. The copy module 800 is used to produce multiple copies of the original digital multimedia product 700. Each of these copies is processed by the embedding module 840. The embedding region selector 810 randomly selects the regions within each copy where the fingerprint embedding will occur. Similarly, the desynchronization region selector 820 randomly selects the regions within each copy to which random desynchronization using width changing will be applied. In some embodiments, the embedding region selector 810 and the desynchronization region selector 820 also select the number of embedding and desynchronization regions. The random desynchronization module 830 randomly selects a width of each of the desynchronization regions. This means that the width of desynchronization regions will be slightly different between different copies of the product 700. By width, it is meant the number of frames (if the product 700 is a movie) or the time length of an audio segment (if the product 700 is an audio recording). The embedding module 840 embeds fingerprints within each of the embedding regions to produce a desynchronized fingerprinted copy 720 of the product 700. FIG. 9 is a block diagram illustrating the details of the detection and extraction module 740 shown in FIG. 7. The detection and extraction module 740 includes a hash value extractor 900, an embedding region determination module 910, a fingerprint detector 920, and a collaborator extraction module 930. The hash value extractor 900 analyzes the illegal copy 730 and extracts hash values. The embedding region determination module 910 uses the extracted hash values and compares them to the hash values of the embedding regions of the original signal to determine the location of the embedding regions within the copy 730. The fingerprint detector 920 searches for fingerprints in each of the embedding regions. Each of the secret keys is used to detect a fingerprint. The collaborator extraction module 930 extract information about a collaborator based on the secret key used to detect a fingerprint. If a fingerprint is detected using a certain secret key, the unique information associated with that key is used to identify a collaborator that was involved in the production of the illegal copy 730. Because there is typically a large number of collaborators, the list of collaborators is generated that participated in the making of the illegal copy 750. VII. Working Example In order to more fully understand the desynchronized fingerprinting system and method disclosed herein, the operational details of an exemplary working example are presented. It should be noted that this working example is only one way in which the desynchronized fingerprinting system and method may be implemented. In this working example, the desynchronized fingerprinting system and method is applied to streaming multimedia objects. The desynchronized fingerprinting system and method can be used for both audio and video applications. In general, a different key is assigned to each user. The embedding feature includes applying a pseudo-random transformation to chosen regions. The key for the pseudo-random transform is user-specific. These regions are chosen via a secure multimedia hash function. The detection and extraction feature includes a brute-force search in the key space of the users. If one of the keys is “likely” enough, it is declared that the user has been involved in the production of an illegal copy. Notation Let the given multimedia signal consist of separate “objects” s1, s2, . . . , sM, where M is the total number of objects. For instance, in a video application, a frame can be treated as an object and M may denote the total number of frames in the video. Alternatively, in an audio application, a fixed-length time-block can be treated as an object and M may denote the total number of such time-blocks. Let N be the total number of customers (or buyers). Accordingly, it is desired to produce N different copies of the multimedia signal. Let Ki be the secret key for user i, 1≦i≦N. Let K be the secret master key, which is different from {Ki}i=1′N. Hash Function Assume that there is a hash function, hK(·) which operates on objects, {si} and its range is {0, 1}L. The hash function is a pseudo-random operator, which is randomized by a secret key K. Let d(·,·) denote the normalized Hamming distance (normalized by L, the length of the output hash value). It is assumed that: 1. hK (si) is approximately uniformly distributed in {0, 1}L for each given i. 2. Pr[d (hK(si), hK(sj))≧T1]≅1, where si and sj are perceptually different objects. 3 Pr [d(h(si),hK(s′i))≦T0]≈1,where si and s′i are perceptually approximately same objects. Note that, the probability space is defined over different keys in the criteria above. For most practical purposes, 0<T0<T1<0.5 and T0 and T1 are sufficiently far apart. Watermarking of Group of Objects In this working example, a pseudo-random watermark embedding function was used, WKi(·), which operates on at most R objects. Here Ki is the key for the pseudo-random number generator used in watermarking. Given 1≦r≦R objects, say s1, . . . sr-1, sr, the watermark embedding function, produces r objects, s1Ki, . . . sr-1Ki,srKi as a function of the key Ki. The objects, { s j K i } j = 1 r are perceptually similar to { s j } j = 1 r . Within this context, watermark embedding function can be viewed as a pseudo-random transformation, indexed by a secret key. Furthermore, the working example assume a corresponding watermark detector function DKi(·), which operates on the same number of objects as the embedder function. The domain of the detector function is {0,1}, where 1 denotes the decision of the presence of the watermark with key Ki; and 0 otherwise. It is assumed that the detector function operates reliably, i.e., 1. Pr [ D K i ( { s ^ j K i } j = 1 r ) = 1 ] ≈ 1 , where { s ^ j K i } j = 1 r are attacked versions of { s j K i } j = 1 r such that they are perceptually similar. 2. Pr [ D K i ( { s ^ j K q } j = 1 r ) = 0 ] ≈ 1 for K i ≠ K q , and Pr[DKi({sj}j=1r)=0]≈1. Mark Embedding of Streaming Multimedia The mark embedding algorithm for user i (1≦i≦N) is given as: 1 . Choose P different locations, randomized by the master key K. Let t1, t2, . . . tp denote these locations, where, tj∈{1,2 . . . N}, 1≦j≦P. 2. Find and store the hash values, { h K ( s t j ) } j = 1 P . 3. For each location tj, consider a neighborhood around it with width, 2Δj+1, thereby find the region j, tj−Δj, tj−Δj+1, . . . , tj+Δj−1,tj+Δj, 1≦j≦P. Here, choose {Δj}j=1P pseudo-randomly using the master key K such that for all j, 2Δj+1≦R and region j does not overlap with region k for all, j≠k. 4. For each 1≦j≦P, replace { s k } k = t j - Δ j t j + Δ j with { s k K i } k = t j - Δ j t j + Δ j = W K i ( { s k } k = t j - Δ j t j + Δ j ) , secret key for user i. Decoding of Streaming Multimedia Let the input to the decoder be the multimedia signal that consists of objects x1; x2, xM′. Note that in general it is possible to have, M′≠M. The detection and extraction (or decoding) process used in the working example includes: 1. For all 1≦j≦M′, compute the hash values of the received signal hK(xj). 2. For each 1≦j≦M′, perform the following: (a) If there exists a tk, 1≦k≦P, such that d(hK(xj), hK(stk))<T0: then proceed to the next step. (b) For all Ki, 1≦i≦N, run a watermark detection algorithm on the width 2Δk+1 region around tk: Compute d i = D K i ( { x j } j = t k - Δ k t k + Δ k ) , 1 ≤ i ≤ N . (c) For each 1≦i≦N, if di=1, declare that user i's mark has been found in the received input. VIII. An Improved Image-Hash Based Temporal Synchronization Algorithm For Digital Video In the working example of the previous section, a general algorithmic description of the desynchronized fingerprinting system and method was presented. In step 2 of the mark embedding algorithm and step 2(a) of the decoding algorithm of the wording example, a single hash value was employed in order to match mark embedding locations. In practice, however, this is not always enough. In particular, for digital video, the hash value of a single image frame is often not sufficient to find embedding locations accurately enough. Thus, in this section, an improved variant of hash-based region matching technique is presented. This technique uses multiple hash values instead of a single hash value. In this section, the discussion is confined to digital video and a robust image hash functions is used that is applied to single video frames (single images). However, it should be noted that the methodology can clearly be extended to collection of frames or digital audio signals. Referring to FIG. 9, the improved variant of hash-based region matching technique presented in this section can be applied in the embedding region determination module 910. The concern is the fact that the mark-embedded video may undergo changes that cause time synchronization problems at detection or decoding. Often, temporal attacks are in this class. In particular, any kind of malicious attack that changes the content order of the video along the time axis (such as scene insertions, changes and swaps, time decimation and interpolation, and shifts) are potentially problematic for decoders. Moreover, even in non-malicious cases, it is possible that the video is cut and pasted or that commercials are inserted in the video for various purposes in the entertainment business. Therefore, a mark-embedded area in the original video might not be at the same temporal location in the received video. In such cases, it is a non-trivial problem to find the mark-embedded locations at the receiver. In order to overcome this problem, the improved variant of hash-based region matching technique presented in this section achieves time synchronization in digital video by using robust image hash functions to determine mark-embedded locations. This technique assumes that the output of a robust image hash function is invariant under both watermark embedding and also acceptable attacks (in other words, the ones that preserve the perceptual quality). The notation for this section will now be defined for the sake of completeness. It should be noted that the notation in this section is different from the notation in Section VII. Notation Bold lowercase letters represent frames, and subscripts represent the indices of elements in a set or vector. Let N be the total number of frames in the original video of interest, and {s1, s2, . . . sN} and {x1, x2, . . . , xN} denote the original and mark-embedded video frames. Let NN be the total number of frames in the attacked video (which is input to the decoder) and {y1, y2, . . . , yNN} denote the attacked video. Note that in general N is not equal to NN. In other words, the length of the attacked video is possibly different from the length of the original and mark-embedded videos. Let M be the total number of embedding regions (i.e., regions where a fingerprint has been embedded). Let h (·) and d (·,·) represent a robust image hash function (that is suitable for use with this hash-based region matching technique and whose specifications are given in Section VII) and the Hamming distance between two binary inputs, respectively. Let td(·,·) denote the temporal distance (with direction information) between any two frames of a given video, e.g., td (sm,sn)=n−m. Encoding and Decoding At the embedder side, for each mark embedding region j (1<=j<=M), K frames are chosen to represent the temporal location of that region. These representative frames are termed as “poles” in the terminology used in this section and denoted by {pjk}, where j (resp. k) corresponds to the mark-embedding region (with respective to the index of the pole inside that region), 1<=j<=M, 1<=k<=K. Obviously, the set of {pjk} is a subset of {s1, s2, . . . , sN}. Here, how to choose {pjk} given a region j will not be discussed. However, in general, as a rule of thumb, poles should be chosen approximately uniformly distributed inside a mark-embedding region so as to represent that region accurately. Let {ajk} be the hash values of {pjk}, i.e., for all j,k, ajk=h(Pjk). The hash values {ajk} are sent as side information to the receiver. In other words, it is assumed that the receiver (or the decoder) has perfect knowledge of {ajk}. The hash values {ajk} are used to “lock” the receiver to the correct position in the attacked video {yi} for each mark embedding region j. In order to achieve this task, the following process must be considered, where M and K are user-dependent parameters: 1. Find {b1, b2, . . . , bNN}, where bi=h(yi), 1<=i<=NN. 2. For each pole pjk, form the perceptual similarity sets Fjk from {yi}, where Fjk={yi|d(bi,ajk)<K, 1<=i<=N}. 3. For each mark-embedding region j, form the set Gj, which consists of all “temporally-suitable” K-tuples from the similarity sets Fjk: Gj={(gj1, gj2, . . . , gjk)| |td(gjk,gj,k+1)−td(pjk,pj,k+1)|<M gjkLFjk, 1<=k<K}. 4. Find the optimal K-tuple for embedding region j in the sense of perceptual similarity via hash: (gj1*, gj2*, . . . , gjk*)=argmin K=1K d(h(jk),ajk), where the minimization is carried out over all element of Gj. 5. The K-tuple (gj1*, gj2*, . . . , gjK*) determines the j-th embedding location in {yi}. Remark Note that, by using this straightforward process, steps 3 and 4 take O(K k=1K|Fjk|) operations. The reason is that the total number of possible K-tuples is k=1K|Fjk| (i.e., exponential in K) and for each K-tuple, this approach needs to perform O(K) operations to find its optimal match in the sense of perceptual similarity (in other words, the Hamming distance to the original hash values). However, there is redundancy in these operations because there exist K-tuples that have common elements for which the Hamming distances between the hash values does not need to be recalculated. Thus, a computationally more efficient approach to solve steps 3 and 4 jointly can be applied by using dynamic programming. Pseudo-Code The following pseudo-code is presented to illustrate the basic idea by using dynamic programming. This would replace steps 3 and 4 above for any j. Furthermore, let Fjk={gjkl}, where I indexes the order of each set element. I. Initialize mindist to a very large number and k=1, l=1. II. While 1<=l<=Fjk, do II.I. Initialize the K-tuple path such that path(m)=0 if m k and path(k)=qjkl, where path(k) is the k-th entry of path. II.II. Initialize dist=d(ajk,h(path(k))), VALIDITY=GOOD. II.III. Apply function FINDOPTPATH(path,dist,k+1,l, VALIDITY) which is defined below. II.IV. Increment|by 1, go to step II.I. function FINDOPTPATH(path,dist,k,l, VALIDITY) I. Initialize ll=1. II. While ll<=|Fjk| do II.I. Compute timedist=|td(path(k−1), qj,k,ll)−td(pj,k−1,pjk). II.II If (k<K) and (timedist>M), II.II.I Set VALIDITY=BAD. II.II.II. Apply function FINDOPTPATH(path,dist,K,ll, VALIDITY). II.III. Else if (k<K) and (timedist<=M), II.III.I. Set path(k)=qj,k,ll, and increment dist by d(ajk,h(path(k))). II.III.II. Apply function FINDOPTPATH(path,dist,k+1,ll, VALIDITY). II.IV. Else if (k=K) and (dist<mindist) and (VALIDITY=GOOD), set mindist=dist and minpath=path. II.V. Increment 1 by 1, go to step II.I. The foregoing description of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description of the invention, but rather by the claims appended hereto. | <SOH> BACKGROUND OF THE INVENTION <EOH>The illegal copying of digital multimedia data products (such as movies and audio recordings) is a widespread problem. The problem only seems to be growing, despite technical advancements in copy protection and mounting efforts to enforce intellectual property rights. This infringement of intellectual property rights can cause great financial harm to the owner. The upward trend in illegal copying seems to be tied to the expanding use of digital media and equipment for storing and distributing digital multimedia data. The enormous growth of Internet technology and digitally stored data has made it possible to easily and inexpensively produce high-quality identical copies of an original. In addition, it is possible to make the copies available to the entire Internet community. This process has become further easier with the usage of peer-to-peer (P2P) networks. With the increasing availability of copying devices and increased bandwidth for digital data, the need to restrain illegal redistribution of digital multimedia data (such as images,. videos and music) has become an important issue. One way to deter illegal copying is to increase the risk of being caught after the piracy has occurred. Storing a unique, invisible mark in each copy (in other words, embedding the mark in the perceptual content of the digital media signal securely and robustly) is a way to increase that risk. In this manner, if an illegal copy is found somewhere, it is possible to find the owner of the copy and to take legal action. This type of enforcement scheme is called fingerprinting (also known as “mark embedding” for forensics in some communities). The idea of fingerprinting is to uniquely mark each copy. This makes each copy bit-wise different from every other copy, and yet otherwise perceptually approximately the same. In this way, it is possible to distinguish between all legal copies. The marking can be used to identify the copy, and thereby the user if his identity is linked to the fingerprint in some way. For example, if the fingerprinted copies are only distributed to those persons who identify themselves, it may be possible, if an illegal copy is found, to identify the owner of the legal copy from which the illegal copy was made. By way of example, assume the owner of a movie on digital video disk (DVD) makes copies of the movie for sale. Each of the copies is fingerprinted. The owner only sells a copy to a user after having individually and uniquely marked each user's copy with a fingerprint and associated each fingerprint uniquely with a buyer. Later, a number of buyers, called pirates, collude in creating an illegal copy that they redistribute (in this situation the pirates are also called colluders). The owner of the movie can analyze an illegal copy and attempt to find out which of the buyers took part in the creation of the illegal copy. The fingerprinting technique includes inserting fingerprints in each copy of a digital product using a watermarking (also termed “mark embedding”) scheme. A watermarking scheme imperceptibly embeds the fingerprint in the perceptual content in a way that it can only be recovered using a secure key. It should be noted that this type of scheme is completely different from conventional Digital Rights Management (DRM) techniques for content protection. There are two important differences between watermarks (for screening purposes to prevent illegal copying or recording) and fingerprints (for forensics purposes to trace the leakage). First, while in watermarking the hidden message (mark) is the same for all buyers (and this mark often represents the identity of the content owner), in fingerprinting the mark depends on the buyer's identity. Second, buyer collusion is not an issue in watermarking (the marked copies for a single content being the same for all buyers). However, in fingerprinting the mark is different for every buyer, and it makes sense for a collusion of buyers to collude by comparing their copies and try to locate and delete some mark bits. Thus, in a collusion attack on fingerprinted digital products, a group of dishonest users colludes to create an illegal copy that hides their identities by putting together different parts of their copies. The attack seeks to eliminate the hidden embedded fingerprints. One problem with current fingerprinting techniques is that they are limited in the number of collaborators that can be identified. For example, several traditional current fingerprinting techniques can only identify between four and eight collaborators. Some newer fingerprinting techniques use fingerprinting codes to enable the detection of an order of magnitude better that traditional fingerprinting techniques. However, there are frequently a large number of collaborators involved in the production of an illegal copy. This means that current fingerprinting techniques cannot accurately detect and identify collaborators greater than one-hundred. This severely limits the deterrent effect of fingerprinting, since collaborators know that all they have to do is collaborate with a large number of other copy owners to avoid detection. Another problem with current fingerprinting techniques is that they are susceptible to estimation attacks. Estimation attacks occur when attackers take all of the frames of the scene and compute an average of all the frames, thereby forming an estimate of the original unmarked content. Alternatively, different techniques may also be used to estimate the fingerprint of each client using the inherent redundancy that is present in the media signal. This tends to greatly weaken or eliminate all of the fingerprints. Therefore, what is needed is a fingerprinting system and method that is capable of accurately identifying at least an order of magnitude greater number of collaborators than current fingerprinting techniques. What is also needed is a fingerprinting system and method that is (cryptographically) secure and resistant to estimation attacks. | <SOH> SUMMARY OF THE INVENTION <EOH>The invention disclosed herein includes a desynchronized fingerprinting method and system that is resistant to attacks and that can identify a large number of collaborators without the use of fingerprinting codes. In particular, the desynchronized fingerprinting method and system disclosed herein is capable of identifying more than an order of magnitude more collaborators than current fingerprinting techniques. The desynchronized fingerprinting system and method can be used for any type of multimedia, particularly audio and video applications. In general, a different key is assigned to each user. The embedding feature includes applying a pseudo-random transformation to chosen regions. The key for the pseudo-random transform is user-specific. These regions are chosen via a secure multimedia hash function. The detection and extraction feature includes a brute-force search in the key space of the users. If one of the keys is “likely” enough, it is declared that the user has been involved in the production of an illegal copy. The desynchronized fingerprinting method includes a desynchronized embedding process and a detection and extraction process. The desynchronized embedding process includes generating copies of an original multimedia product (where each copy is a pseudo-random desynchronized version of the original) and randomly selecting both desynchronization and embedding regions in which to embed fingerprints. The pseudo-random “intentional” desynchronization prior to actual mark embedding ensures that it is difficult for colluders to find a good estimate of the unmarked original signal (such as, for example, by using averaging-type attacks). This is because it is necessary for the colluders to “align” their copies with respect to each other for collusion, and this becomes more difficult as the number of colluders increases (assuming the total computation power is limited). A random desychronization process includes mapping the width of each desynchronization region to a pseudo-randomly determined quantity such that they vary between copies for different clients. A master key is used in the random desychronization process. Similarly, a master key and a hash function are used to randomly select the embedding regions. Unique copy information and secret keys then are embedded in the embedding regions. In general, embedding regions and desynchronization regions need not be the same, though they can overlap. The detection and extraction process includes obtaining an illegal copy of the original digital multimedia product. Hash values are computed for the illegal copy, and these hash values are used to determine the embedding regions by comparing them to the hash values of the embedding regions of the original content. In essence, robust perceptual hash functions are used to “lock” to the embedding locations at the receiver. Watermark detection then is performed on each of the embedding regions using each one of the secret keys. Identification information is detected and collaborator information is extracted to construct a list of collaborators. These collaborators represent persons who collaborated on the production of the illegal copy. | 20040211 | 20080603 | 20050811 | 58786.0 | 0 | CHAWAN, SHEELA C | DESYNCHRONIZED FINGERPRINTING METHOD AND SYSTEM FOR DIGITAL MULTIMEDIA DATA | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,777,924 | ACCEPTED | Emergency shower system | An emergency shower system for attachment to a water pipe located behind a wall and a valve mounted to the pipe. The system includes a frame mounted to the wall around the valve, a panel connected to the frame for covering an opening in the wall to expose the valve, the panel having an opening, a plate mounted to the panel to close the panel opening and a handle mounted to the plate. The system also includes a linkage pivotally connected to the plate and to the valve, such that vertical movement of the handle and plate are translated to rotational movement by the linkage so as to operate the valve. There are no openings apparent in the front of the shower system. The handle only moves vertically and at a constant distance of about one and a half inches from the wall. An eye/face wash station may be included with the shower. The eye/face wash station includes a pull down tray with two spray nozzles. The nozzles are connected to another valve which is opened by the rotation of the pull down tray. | 1. An emergency shower system operable with a fluid, a fluid delivery apparatus, a dispensing shower head and a valve for controlling the flow of fluid, the system comprising: a frame having an opening to provide access to the valve; a panel mounted over said frame opening and having a panel opening; a plate movable adjacent said panel to close said panel opening, said plate being movable relative to said panel between two positions; a handle connected to said plate for moving said plate; a linkage connecting said plate to said valve whereby movement of said plate between said two positions causes operation of said valve; and said plate and said panel being structured and dimensioned to collectively cover said frame opening. 2. The system as claimed in claim 1 wherein: said frame mounts to a wall having an opening. 3. The system as claimed in claim 1 wherein: said plate moves vertically between said two positions; and said linkage translates the vertical movement of said plate to rotational movement at said valve. 4. The system as claimed in claim 3 wherein: said linkage includes a front link pivotally connected to said plate and a rear link pivotally connected to said front link and to said valve. 5. The system as claimed in claim 4 wherein: said handle extends away from said plate about one and a half inches. 6. The system as claimed in claim 1 wherein said handle extends away from said plate about one and a half inches. 7. The system as claimed in claim 1 including: an eye/face wash station, said station including a rotatable tray, two spray nozzles mounted to said tray, a second valve connected to said tray, said valve being operated by said rotatable tray. 8. The system as claimed in claim 5 including: an eye/face wash station, said station including a rotatable tray, two spray nozzles mounted to said tray, a second valve connected to said tray, said valve being operated by said rotatable tray. 9. The system as claimed in claim 1 wherein: said linkage includes first and second links which are pivotally connected to said plate, to said valve and to each other. 10. The system as claimed in claim 1 wherein: said plate is mounted to move vertically. 11. The system as claimed in claim 1 wherein: said handle moves parallel to said panel during movement of said plate. 12. The system as claimed in claim 1 including: an eye/face wash station having a rotatable tray, a pair of fluid dispensers and a valve, said tray being movable from a closed generally vertical position to an open generally horizontal position. 13. The system as claimed in claim 1 wherein: said plate is mounted to move vertically; and said handle moves parallel to said panel during movement of said plate. 14. The system as claimed in claim 13 wherein: said linkage includes first and second links which are pivotally connected to said plate, to said valve and to each other. 15. The system as claimed in claim 14 including: an eye/face wash station having a rotatable tray, a pair of fluid dispensers, a valve, and a delivery apparatus connected to said valve and to said pair of dispensers, said tray moving from a closed generally vertical position to an open generally horizontal position. 16. An emergency shower system comprising: a pipe adapted to be connected to a fluid source, said pipe being located behind a wall and said wall having an opening; a valve connected to said pipe; a showerhead connected to said pipe; a frame connected to said wall in said opening, said frame having an opening; a panel mounted over said frame opening, said panel having an opening; a movable plate mounted to said panel for closing said panel opening; a handle mounted to said plate for moving said plate in a vertical direction; and a linkage pivotally connected to said plate and to said valve for translating vertical motion of said plate to rotational motion at said valve. 17. The system as claimed in claim 14 including: an eye/face wash station having a pull down tray and a spray nozzle. 18. An emergency shower system to be connected to a fluid source, the flow of fluid being controlled by a valve, said system comprising: a linkage connected to said valve for operating said valve; and a plate having an inner surface and an outer surface connected to said linkage for moving said linkage and for completely covering said linkage to prevent liquid and debris beyond said outer surface from contacting said linkage. 19. The system as claimed in claim 18 including: a handle connected to said plate for moving said plate in a vertical direction; and wherein said handle extends away from said plate a distance of about one and a half inches. 20. The system as claimed in claim 19 including: an eye/face wash station including a rotatable tray, a spray nozzle mounted to said tray and a second valve operable by rotation of said tray. | BACKGROUND OF THE INVENTION CROSS REFERENCE TO RELATED APPLICATIONS Not applicable. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH Not applicable. FIELD OF THE INVENTION The present invention relates to an emergency shower system and more particularly, to an emergency shower system that is easy to operate and to safely integrate into an appropriate environment, such as a laboratory, a school or a municipal, commercial or industrial facility. DESCRIPTION OF THE RELATED ART Emergency showers are often used in industry, laboratory and academic environments where researchers, students and workers may be exposed to hazardous materials and/or conditions. It is important that such emergency showers be easily operated in an emergency situation, where for example, a user may not have use of his/her eyes. The showers must also operate effectively once activated even though they may be seldom used. Further, the shower mechanism must be designed with safety in mind so that there is little likelihood that the structural components of the shower will cause injury at any time and, particularly, during usage. U.S. Pat. No. 5,768,721 illustrates an example of an existing emergency shower. The patent discloses an emergency shower installed in a recessed area in a wall behind which water pipes are located. A valve mounted to the water pipes is operated by a pivoting handle. The installation covers most but not all of the wall recess into which the shower control mechanism is mounted. The handle is required to move along a path and this necessitates a slot. This slot provides an opening into the recess where the handle mechanism operates and through which water may enter. This water may collect in the recess and behind the wall so that, over a period of time, the collected water may cause damage to the fascia and other structural components of the shower installation and, also, presents a potential for mildew and/or mold problems. Furthermore, the slot disclosed in U.S. Pat. No. 5,768,721 presents an opening in the front face of the device described there which invites the intentional or unintentional deposit of debris, particularly when the shower device is located in an open environment, such as those presented in a laboratory, a school or a municipal, commercial or industrial facility and the like. Thus, over time, sufficient debris or extraneous objects may be introduced into the recess through the slot opening to prevent complete rotation of the operating handle and, thus, block effective operation of the emergency shower valve during an emergency situation. Another drawback of a pivoting handle as described in U.S. Pat. No. 5,768,721 is that by its nature the handle moves in an arc which is contrary to current safety practices. Furthermore this arced motion varies the distance that the handle extends outwardly from the adjacent wall. This outward movement may interfere with operation of the handle should a stressed or panicked user not recognize that the handle will first move toward him/her and then away when the handle is rotated from a shower-off to a shower-on position. BRIEF SUMMARY OF THE INVENTION The difficulties encountered with previous devices have been overcome by the present invention. What is described here is an emergency shower system which is operable with a fluid delivery apparatus, a shower dispenser connected to the fluid delivery apparatus, a valve connected to the fluid delivery apparatus for controlling the flow of fluid through the fluid delivery apparatus, the system including frame, a panel connected to the frame, the panel having an opening therein, a plate slidably mounted behind the panel for closing the opening in the panel, a handle connected to the plate for moving the plate relative to the covering panel, and a linkage connecting the plate to the valve for operating the shower, the plate and panel covering the linkage and valve. In a preferred embodiment, the control valve is positioned behind a wall and is accessible through an opening in the wall; the plate is mounted for slidable movement in a substantially linear plane essentially parallel to the wall. There are a number of advantages, features and objects achieved with the present invention which are believed not to be available in earlier related devices. For example, an object of the present invention is to provide an emergency shower system that is advantageously easy to operate and is safe in its environment after installation. Another object of the present invention is to provide an emergency shower system with an operating handle that extends a minimal distance from an adjoining wall. A further advantage of the present invention is that the emergency shower system has no front facing opening or slot into which water can be introduced that could cause a potential for mildew formation over time. Another advantage derived from the elimination of the front facing opening or slot in the emergency shower system of the present invention is that no debris can be introduced through the covering panel which could cause interference with movement of the operating handle. In other words, the system mechanism is fully enclosed. Other features and advantages of the present invention include the provision of an emergency shower system which is simple, reliable and relatively inexpensive. A complete understanding of the present invention and other objects, advantages and features thereof will be gained from a consideration of the present specification which provides a written description of the invention, and of the manner and process of making and using the invention, set forth in such full, clear concise and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same in compliance with Title 35 U.S.C. section 112 (first paragraph). Furthermore, the following description of preferred embodiments of the invention read in conjunction with the accompanying drawing provided herein represents examples of the invention in compliance with Title 35 U.S.C. section 112 (first paragraph), but the invention itself is defined only by the attached claims. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a diagrammatic side elevation view of an installed emergency shower system illustrating the positions of an operating handle in both “on” and “off” orientations. FIG. 2 is a diagrammatic front elevation view of a portion of the emergency shower system illustrated in FIG. 1 as it would appear to potential shower users. FIG. 3 is an enlarged, exploded, partially broken-away isometric view of the emergency shower system illustrating the shower system's operating mechanism. FIG. 4 is a diagrammatic elevation view of the operating handle on a plate of the emergency shower system shown in FIGS. 1-3 illustrating the locations of the handle in a shower-off position (broken line) and in a shower-on position (solid line). FIG. 5 is a diagrammatic elevation view of a linkage alignment when the emergency shower system is in the shower-off position. FIG. 6 is a diagrammatic elevation view of the linkage alignment when the emergency shower system is in the shower-on position. FIG. 7 is a diagrammatic side elevation view of an installed emergency shower system with a combined eye/face wash station in an open position. FIG. 8 is a diagrammatic front elevation of a portion of the combined system shown in FIG. 7 with the eye/face wash station in a closed position. FIG. 9 is an isometric view of a portion of the combined system shown in FIGS. 7 and 8 illustrating the eye/face wash station of the combined system in an open, operating position. FIG. 10 is an enlarged, exploded, isometric view of the combined system shown in FIGS. 7-9. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION While the present invention is open to various modifications and alternative constructions, the preferred embodiments illustrating the best mode contemplated by the inventors of carrying out their invention are shown in the various figures of the drawing and will be described herein in detail, pursuant to Title 35 U.S.C. section 112 (first paragraph). It is understood, however, that there is no intention to limit the invention to the particular embodiments, forms or examples which are disclosed herein. To the contrary, the intention is to cover all modifications, equivalent structures and methods, and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims, pursuant to Title 35 U.S.C. section 112 (second paragraph). Referring now to FIGS. 1-3, an emergency shower system 10 is illustrated in a typical installation. The emergency shower system is connected to a fluid delivery apparatus such as water pipes 12 mounted behind a wall 14 with water flow being controlled by a valve 20. Water is dispersed from a shower head 16 mounted flush with a ceiling 18. The system includes a frame 22 in an opening 24 formed in the wall 14, a cover panel 26 mounted to the frame 22, a plate 28 slidably mounted behind to the cover panel 26, a shower operating handle 30 attached to the plate 28, and a linkage 32 connected to the plate 28 and to the valve 20 to translate linear motion of the handle and the plate to rotating motion for the valve. The plate has an inner surface 31 and an outer surface 33. It is to be understood that the system may also include the valve and shower head. Usually the water pipes are a preexisting part of a building structure. However, the system may include an entire installation including water pipes, a wall and an opening formed in the wall. The shower head 16 is shown flush with the ceiling 18 although it should be recognized that within the scope of the present invention, the shower dispenser head 16 may extend outwardly from the wall 14 or extend downwardly from the ceiling 18 if so desired. The shower head 16 is directly connected to the water pipes 12. The pipes extend from a source 34, usually a potable water supply such as a municipal water main, which is brought in from under a building structure and then extended behind the wall 14 to connect to the shower head. Beneath the shower head is a floor 36 which may have an arrangement for a drain (not shown). The valve 20 is positioned behind the wall and is connected in line with the pipes. The valve is operable to prevent the passage of water when the shower is in an “off” or “closed” mode and allows the passage of water when the shower is in an “on” or “open” mode. Mounted around the valve and adjoining pipes is the frame 22 which is inserted into the opening 24 in the wall 14 and is attached to the wall by any suitable fasteners. The cover panel 26 is mounted to the frame 22 and mounted to the panel is a pictograph 40 illustrating how the handle 30 is to be operated. Beneath the pictograph is a rectangular opening 42 which provides access to the plate 28. The handle 30 allows a user to slide the plate relative to the panel and thereby operate the shower system. An important feature of the emergency shower system 10 is that there is no opening available to allow the introduction of water or debris through the wall opening which could cause mildew formation or could interfere with the effective functioning of the valve 20 or the linkage 32. The frame 22, the panel 26 and the plate 28 effectively block all access through the wall opening. More particularly, there is no slot or other opening as in the above mentioned patent. This construction overcomes the serious drawback presented by the handle slot, whereby water or other liquid could enter the recess and present a mildew forming condition or an object or some other form of debris could be stuck into the slot and prevent operation of the emergency shower assembly. As may be best seen in FIG. 2, the present system is fully enclosed and no openings are presented to a user or to a passing person who would be beyond the outer surface 33 of the plate, i.e., someone positioned in front of the system so that the system appears to that person as it is depicted in FIG. 2. Referring now to the detail illustrated in FIG. 3, it is noted that the frame 22 is positioned in front of a portion of the pipes 12 as well as the valve 20 and provides ready access to the valve. It is noted that the pipes and the valve may be offset and placed behind the wall adjacent the frame and the wall opening, if desired. The frame 22 includes a series of holes, such as the hole 50, for receiving fasteners, such as a screw 52, to allow the frame to be attached to the wall 14. Holes, such as the hole 54 in the frame and hole 56 in the panel are provided to receive fasteners, such as a screw 58, to attach the panel to the frame. Spacers, such as a spacer 60, provide room for the sliding plate and act as plate guides. The handle 30 may be attached to the plate 28 in any convenient fashion, such as with the use of fasteners (not shown). The valve 20 may be of a standard ball type with a stem 80 projecting in an outwardly horizontal direction. A suitable valve is made by Conbraco Industries, Inc. of Matthews, N.C. and sold under the APOLLO brand, Model 70-105-01. Pivotally mounted to the plate 28 is the linkage 32. The linkage includes a first or front link 82 and an L-shaped second or rear link 84. A pair of openings 86, 88 are located at the end portions of the link. The rear link 84 has a vertical arm portion 90 and a horizontal arm portion 92, each with an opening 94, 96 at end portions thereof. The lower opening 88 of the front link 92 allows the front link to be pivotally connected to the plate, which also has an opening 98, with a fastener 100. The upper opening 86 of the front link 82 allows the front link to be pivotally connected to the vertical arm portion 90 of the rear link 84 with a fastener 102 through the opening 94. The horizontal arm portion 82 of the rear link 84 is mounted to the stem 80 of the ball valve by having the stem inserted into the opening 96 and retained there by a fastener 104. It may now be appreciated that vertical movement of the plate causes rotational movement of the ball valve stem by way of the linkage. In this way, a light force on the handle of the plate is magnified by the linkage to rotate the valve stem. In FIGS. 4-6, the operation of the shower is shown in more detail. Vertical movement of the handle from an upper position, shown in broken line in FIG. 4, downwardly, as depicted by an arrow 110, to the lower position shown in solid line is sufficient movement by a shower user to cause the shower to go from “off” when the handle is in its upper position to “on” when the handle is in its lower position. When the handle is in its upper position, the links 82, 84 are shown generally in the position illustrated in FIG. 5. In this position, the valve stem 80 is disposed in a horizontal orientation. However, when the handle and the plate are moved vertically downwardly, the fastener 100 in the bottom portion of the front link and the bottom portion of the plate is pulled downwardly as depicted by an arrow 111, causing the fastener 102 in the upper portion of the front link to pivot the vertical arm portion 90 of the rear link 84. This causes the rear link 84 to rotate clockwise as depicted by an arrow 112 about the connection of the arm portion 92 and the valve stem 80. The vertical movement of the handle, which is approximately 4.85 inches, causes a rotational movement of the ball valve stem of approximately ninety degrees. The ball valve is designed so that when the valve stem 80 is horizontally oriented, the valve blocks or closes the pipes to the passage of any water. However, when the valve stem is rotated, a passage is opened through the valve for the water in the pipes to flow to the shower head. Manipulating the handle 30 is very convenient and requires little force and movement to turn the shower to “on”. There is little friction in the linkage system and the links are long enough to provide sufficient torque to the valve stem 80 so that rotation is simple and easy. It is to be noted that the handle moves parallel to the panel and does not swing outwardly in an arc as is the situation with some shower devices. The handle is sufficiently large to be easily gripped by a user and extends only about one and a half inches from the wall so that the handle does not interfere with the normal operation of a laboratory or manufacturing plant, such as when someone walks past the wall where the emergency shower system is installed. Hence, the emergency shower system may be mounted in a hallway. It is also noted that the handle and linkage are simple, reliable and relatively inexpensive. It is to be understood that a fluid other than water may flow through the pipes, or water may be mixed with chemicals, if desired. In operation of the emergency shower system of the present invention, an individual who, for example, has accidentally encountered an emergency situation such as a hazardous substance spill or leak and the like, immediately goes to the emergency shower system installation and while positioned under the showerhead pulls the shower operating handle downwardly. This short, vertical, downward motion is translated by the linkage to rotational motion so as to rotate the ball valve from a closed position to an open position, thereby allowing water to flow from the source through the pipes to the showerhead. To cause the shower to go from “on” to “off”, a user merely lifts the handle back to its original, upper position. The above specification describes in detail one preferred embodiment of the present invention. In an alternative preferred embodiment, as illustrated in FIGS. 7-10, an optional eye/face wash section is combined with the shower apparatus to form a combined emergency shower system. In such an arrangement, the structure and operation of the shower portion of the system is essentially the same as the above described system and as illustrated in FIGS. 1-6. In the FIGS. 7-10 embodiment 136 there is an enlarged frame 120 in front of pipes 122 and a valve 124. A panel 126, a plate 128, a handle 130, a linkage 132 and a pictograph 134 are connected to the frame. Adjacent to the shower is an eye/face wash station 138. Included in the eye/face wash station is a pull down tray 140, an operating handle 142, a pair of water nozzles 144, 146, a branch pipe 148, a second valve 150, a supply pipe 152, a hook 154 and an access panel 156. In greater detail, the cover panel 126 of the shower station is mounted to the frame 120 by screw fasteners 158 on the right side of the system, and the optional eye/face wash station 138 is mounted to the frame for rotatable movement on the left side of the system. The supply pipe 152 is connected to the valve 150 which is rotated from a closed position to an open position when the tray 150 is rotated from its up, folded position as shown in FIGS. 8 and 10 to its down, operating position shown in FIGS. 7 and 9. The branch pipe 148 extends off the main pipe 122 to feed water to the eye/face wash station. The handle 142 is fastened to the front or underside of the tray to move the tray from its “up” vertical position to its “down” horizontal position. The handle 142 of the eye/face wash station extends about one and a half inches from the tray, essentially the same distance as the handle 130 of the shower. Hence, there is minimal impediment to the area around the system. Specifically, operation of the eye/face wash station of the emergency shower system is activated by moving the tray from its up position to its down position. During this maneuver of rotating the tray approximately ninety degrees, the valve 150, illustrated as a ball valve, goes from a closed position to an open position where water is delivered to the pair of nozzles 144, 146 which are ideally situated to wash a user's eyes and face and thereby dilute and wash away hazardous chemicals. To turn the water off on the left side of the system, the tray is lifted from the horizontal, down position to the vertical, up position during which the second valve moves from an open position to a closed position. The plate 128 of the shower system is attached to pivot a front link 160 by a fastener 162 and the front link is pivotally attached to a rear link 164 by a fastener 166. The rear link is attached to a valve stem 168 by a fastener 170. Vertical movement of the plate 128 by a downward pull of the handle 130, rotates the links and opens the valve 124. This causes water to flow in the pipes 122 behind the wall 14 to a shower dispenser head 172 suspended below the ceiling 18. The above specification describes in detail preferred embodiments of the present invention. Other examples, embodiments, modifications and variations will, under both the literal claim language and the doctrine of equivalents, come within the scope of the invention defined by the appended claims. For example, whether the showerhead is located as shown or flush with the ceiling or the wall or in some other disposition is considered an equivalent as are different handle shapes or dimensions, or shapes and dimensions of the linkage. The type of valve used may be changed to an equivalent structure. The fluid in the pipes may be water, a chemical or a mix of both. Still other alternatives will also be equivalent as will many new technologies. There is no desire or intention here to limit in any way the application of the doctrine of equivalents nor to limit or restrict the scope of the invention. | <SOH> BACKGROUND OF THE INVENTION <EOH> | <SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The difficulties encountered with previous devices have been overcome by the present invention. What is described here is an emergency shower system which is operable with a fluid delivery apparatus, a shower dispenser connected to the fluid delivery apparatus, a valve connected to the fluid delivery apparatus for controlling the flow of fluid through the fluid delivery apparatus, the system including frame, a panel connected to the frame, the panel having an opening therein, a plate slidably mounted behind the panel for closing the opening in the panel, a handle connected to the plate for moving the plate relative to the covering panel, and a linkage connecting the plate to the valve for operating the shower, the plate and panel covering the linkage and valve. In a preferred embodiment, the control valve is positioned behind a wall and is accessible through an opening in the wall; the plate is mounted for slidable movement in a substantially linear plane essentially parallel to the wall. There are a number of advantages, features and objects achieved with the present invention which are believed not to be available in earlier related devices. For example, an object of the present invention is to provide an emergency shower system that is advantageously easy to operate and is safe in its environment after installation. Another object of the present invention is to provide an emergency shower system with an operating handle that extends a minimal distance from an adjoining wall. A further advantage of the present invention is that the emergency shower system has no front facing opening or slot into which water can be introduced that could cause a potential for mildew formation over time. Another advantage derived from the elimination of the front facing opening or slot in the emergency shower system of the present invention is that no debris can be introduced through the covering panel which could cause interference with movement of the operating handle. In other words, the system mechanism is fully enclosed. Other features and advantages of the present invention include the provision of an emergency shower system which is simple, reliable and relatively inexpensive. A complete understanding of the present invention and other objects, advantages and features thereof will be gained from a consideration of the present specification which provides a written description of the invention, and of the manner and process of making and using the invention, set forth in such full, clear concise and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same in compliance with Title 35 U.S.C. section 112 (first paragraph). Furthermore, the following description of preferred embodiments of the invention read in conjunction with the accompanying drawing provided herein represents examples of the invention in compliance with Title 35 U.S.C. section 112 (first paragraph), but the invention itself is defined only by the attached claims. | 20040211 | 20060801 | 20050811 | 67720.0 | 0 | FETSUGA, ROBERT M | EMERGENCY SHOWER SYSTEM | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,777,959 | ACCEPTED | Communications system with data storage device interface protocol connectors and related methods | A communications system may include a plurality of data storage devices for storing data using at least one of a plurality of different operating protocols. The system may further include a plurality of mobile wireless communications devices for accessing the data storage devices and each using at least one of the plurality of different operating protocols. Moreover, a protocol interface device may also be included. The protocol interface device may include a front-end proxy module for communicating with the plurality of mobile wireless communications devices using respective operating protocols, and a protocol engine module communicating with the front-end proxy module using a common interface protocol. The protocol interface device may also include a respective interface connector module for translating communications between the protocol engine module and the plurality of data storage devices for each of the different operating protocols. | 1. A communications system comprising: a plurality of data storage devices for storing data using at least one of a plurality of different operating protocols; a plurality of mobile wireless communications devices for accessing said data storage devices and each using at least one of the plurality of different operating protocols; and a protocol interface device comprising a front-end proxy module for communicating with said plurality of mobile wireless communications devices using respective operating protocols, a protocol engine module communicating with said front-end proxy module using a common interface protocol, and a respective interface connector module for translating communications between said protocol engine module and said plurality of data storage devices for each of the different operating protocols. 2. The communications system of claim 1 wherein said protocol engine module comprises a universal proxy servlet module. 3. The communications system of claim 2 wherein said protocol interface device further comprises a plurality of provider modules coupled between said universal proxy servlet module and said plurality of interface connector modules; and wherein said universal proxy servlet module generates calls for said plurality of interface connector modules based upon respective data access requests from said front-end proxy module, and wherein said plurality of provider modules transfer the calls to respective interface connector modules. 4. The communications system of claim 1 wherein said interface connector modules comprise a plurality of a Microsoft Exchange connector module, a Domino connector module, an America Online (AOL) connector module, a Hotmail connector module, a Microsoft Network (MSN) connector module, a Compuserve connector module, a Post Office Protocol (POP) connector module, and an Internet Message Access Protocol (IMAP) connector module. 5. The communications system of claim 1 wherein said plurality of data storage devices, said plurality of mobile wireless communications devices, and said protocol interface device process electronic mail (e-mail) messages. 6. The communications system of claim 1 wherein the common interface protocol is based upon a Web-based distributed authoring and versioning (WebDAV) protocol. 7. The communications system of claim 1 wherein said protocol interface device generates an error responsive to at least one non-supported operating protocol. 8. The communications system of claim 1 further comprising a wide area network (WAN) connecting at least one of said mobile wireless communications devices with said protocol interface device. 9. The communications system of claim 1 further comprising a wide area network (WAN) connecting at least one of said data storage devices with said protocol interface device. 10. A protocol interface device for interfacing a plurality of mobile wireless communications devices with a plurality of data storage devices, the mobile wireless communications devices and the data storage devices each using at least one of a plurality of different operating protocols, the protocol interface device comprising: a front-end proxy module for communicating with the plurality of mobile wireless communications devices using respective operating protocols; a protocol engine module communicating with the front-end proxy module using a common interface protocol; and a respective interface connector module for translating communications between said protocol engine module and the plurality of data storage devices for each of the different operating protocols. 11. The protocol interface device of claim 10 wherein said protocol engine module comprises a universal proxy servlet module. 12. The protocol interface device of claim 11 further comprising a plurality of provider modules coupled between said universal proxy servlet module and said plurality of interface connector modules; and wherein said universal proxy servlet module generates calls for said plurality of interface connector modules based upon respective data access requests from said front-end proxy module, and wherein said plurality of provider modules transfer the calls to respective interface connector modules. 13. The protocol interface device of claim 10 wherein the plurality of data storage devices, the plurality of mobile wireless communications devices, and the protocol interface device process electronic mail (e-mail) messages. 14. The protocol interface device of claim 10 wherein the common interface protocol is based upon a Web-based distributed authoring and versioning (WebDAV) protocol. 15. A protocol interface device for interfacing a plurality of communications devices with a plurality of data storage devices, the communications devices and the data storage devices each using at least one of a plurality of different operating protocols, the protocol interface device comprising: a front-end proxy module for communicating with the plurality of communications devices using respective operating protocols; a protocol engine module communicating with the front-end proxy module using a common interface protocol; and a respective interface connector module for translating communications between said protocol engine module and the plurality of data storage devices for each of the different operating protocols. 16. The protocol interface device of claim 15 wherein said protocol engine module comprises a universal proxy servlet module. 17. The protocol interface device of claim 16 further comprising a plurality of provider modules coupled between said universal proxy servlet module and said plurality of interface connector modules; and wherein said universal proxy servlet module generates calls for said plurality of interface connector modules based upon respective data access requests from said front-end proxy module, and wherein said plurality of provider modules transfer the calls to respective interface connector modules. 18. The protocol interface device of claim 15 wherein the plurality of data storage devices, the plurality of mobile wireless communications devices, and the protocol interface device process electronic mail (e-mail) messages. 19. The protocol interface device of claim 15 wherein the common interface protocol is based upon a Web-based distributed authoring and versioning (WebDAV) protocol. 20. A method for interfacing a plurality of mobile wireless communications devices with a plurality of data storage devices, the mobile wireless communications devices and the data storage devices each using at least one of a plurality of different operating protocols, the method comprising: providing a front-end proxy module for communicating with the plurality of mobile wireless communications devices using respective operating protocols; providing a protocol engine module communicating with the front-end proxy module using a common interface protocol; and providing a respective interface connector module for translating communications between the protocol engine module and the plurality of data storage devices for each of the different operating protocols. 21. The method of claim 20 wherein the protocol engine module comprises a universal proxy servlet module. 22. The method of claim 21 further comprising a plurality of provider modules coupled between the universal proxy servlet module and the plurality of interface connector modules; and wherein the universal proxy servlet module generates calls for the plurality of interface connector modules based upon respective data access requests from the front-end proxy module, and wherein the plurality of provider modules transfer the calls to respective interface connector modules. 23. The method of claim 20 wherein the plurality of data storage devices, the plurality of mobile wireless communications devices, and the protocol interface device process electronic mail (e-mail) messages. 24. The method of claim 20 wherein the common interface protocol is based upon a Web-based distributed authoring and versioning (WebDAV) protocol. 25. A computer-readable medium having computer executable modules for interfacing a plurality of mobile wireless communications devices with a plurality of data storage devices, the mobile wireless communications devices and the data storage devices each using at least one of a plurality of different operating protocols, the computer-readable medium comprising: a front-end proxy module for communicating with the plurality of mobile wireless communications devices using respective operating protocols; a protocol engine module communicating with the front-end proxy module using a common interface protocol; and a respective interface connector module for translating communications between the protocol engine module and the plurality of data storage devices for each of the different operating protocols. 26. The computer-readable medium of claim 25 wherein the protocol engine module comprises a universal proxy servlet module. 27. The computer-readable medium of claim 26 further comprising a plurality of provider modules coupled between the universal proxy servlet module and the plurality of interface connector modules; and wherein the universal proxy servlet module generates calls for the plurality of interface connector modules based upon respective data access requests from the front-end proxy module, and wherein the plurality of provider modules transfer the calls to respective interface connector modules. 28. The computer-readable medium of claim 25 wherein the plurality of data storage devices, the plurality of mobile wireless communications devices, and the protocol interface device process electronic mail (e-mail) messages. 29. The computer-readable medium of claim 25 wherein the common interface protocol is based upon a Web-based distributed authoring and versioning (WebDAV) protocol. | CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application Nos. 60/493,165, 60/493,167, 60/493,163 filed Aug. 7, 2003, and 60/494,235, 60/494,326, 60/494,255, and 60/494,234, filed Aug. 11, 2003 all of which are hereby incorporated herein in their entireties by reference. FIELD OF THE INVENTION The present invention relates to the field of communications systems, and, more particularly, to communications systems using multiple operating protocols for data access operations and related methods. BACKGROUND OF THE INVENTION Software clients operating on or in conjunction with a computer system are often used to access data stored at a server with which the computer system can establish communications, such as through a local area on the server is accessible only through a particular protocol, which in turn tends to limit a user to a particular client. Similarly, a particular type of client is typically configurable to operate with only certain types of servers or protocols. In an e-mail system, for example, in which users have associated mailboxes on a mail server, a particular protocol and often a particular messaging client is required for e-mail access. There is no single standard method for accessing e-mail stored on a server. Instead, there are several incompatible protocols defined by various vendors and standards bodies. In addition, the explosion of the Internet has resulted in several key problems. First, in order to obtain control over their user base, several Internet-based e-mail providers have extended standard protocols with their own proprietary extensions. Other vendors have gone away from RFC-based protocols and have defined new protocols from the ground up. Moreover, many vendors have chosen to implement standard protocols such as Internet Message Access Protocol (IMAP) and Post Office Protocol (POP), but have interpreted the rules of these protocols differently. Because of this proliferation of access mechanisms, there is no single way to access all of these mail stores. Applications that need to access these mail stores quickly become overly complicated when attempting to account for all of the different protocols and implementations of the protocols. Various prior art approaches have been developed for providing communications between systems and devices using different operating protocols. One such approach is set forth in U.S. Pat. No. 6,615,212 to Dutta et al., in which a transcoding proxy server receives a request for content from a client machine. The transcoding proxy server retrieves the content from an originating server. The retrieved content is provided in a first format type. In response to a determination that an increase in efficiency would be obtained by allowing the client to process the content in the first format type prior to transcoding the content into a second format type, the transcoding proxy server sends the content to the client in the first format type. Furthermore, in response to a determination that the client does not have content processing software for processing the content in the first format, the transcoding proxy server sends content processing software for the first format type along with the content in the first format type to the client. The transcoding proxy server then transcodes the content from the first format type into the second format type and sends the content in the second format to the client. Despite such prior art approaches, further protocol translation and/or conversion functionality may be desirable in certain applications. SUMMARY OF THE INVENTION In view of the foregoing background, it is therefore an object of the present invention to provide a communications system providing enhanced operating protocol conversion features and related methods. This and other objects, features, and advantages in accordance with the present invention are provided by a communications system which may include a plurality of data storage devices for storing data using at least one of a plurality of different operating protocols. The system may further include a plurality of mobile wireless communications devices for accessing the data storage devices and each using at least one of the plurality of different operating protocols. Moreover, a protocol interface device may also be included. The protocol interface device may include a front-end proxy module for communicating with the plurality of mobile wireless communications devices using respective operating protocols, and a protocol engine module communicating with the front-end proxy module using a common interface protocol. The protocol interface device may also include a respective interface connector module for translating communications between the protocol engine module and the plurality of data storage devices for each of the different operating protocols. More particularly, the protocol engine module may be a universal proxy servlet module. In addition, the protocol interface device may also include a plurality of provider modules coupled between the universal proxy servlet module and the plurality of interface connector modules. The universal proxy servlet module may generate calls for the plurality of interface connector modules based upon respective data access requests from the front-end proxy module, and the plurality of provider modules transfer the calls to respective interface connector modules. By way of example, the interface connector modules may include a Microsoft Exchange connector module, a Domino connector module, an America Online (AOL) connector module, a Hotmail connector module, a Microsoft Network (MSN) connector module, a Compuserve connector module, a Post Office Protocol (POP) connector module, and an Internet Message Access Protocol (IMAP) connector module. Of course, other interface connector modules may also be used. The plurality of data storage devices, the plurality of mobile wireless communications devices, and the protocol interface device may process electronic mail (e-mail) messages, for example. Also, the common interface protocol may be based upon a Web-based distributed authoring and versioning (WebDAV) protocol. Furthermore, the protocol interface device may generate an error responsive to at least one non-supported operating protocol. The communications system may further include a wide area network (WAN), such as the Internet, connecting at least one of the mobile wireless communications devices with the protocol interface device. Additionally, such a WAN may also be used to connect at least one of the data storage devices with the protocol interface device. A method aspect of the invention is for interfacing a plurality of mobile wireless communications devices with a plurality of data storage devices. The mobile wireless communications devices and the data storage devices may each use at least one of a plurality of different operating protocols. The method may include providing a front-end proxy module for communicating with the plurality of mobile wireless communications devices using respective operating protocols, and providing a protocol engine module communicating with the front-end proxy module using a common interface protocol. The method may further include providing a respective interface connector module for translating communications between the protocol engine module and the plurality of data storage devices for each of the different operating protocols. A protocol interface device in accordance with the invention may include a front-end proxy module and a protocol engine module, such as those described briefly above, for example. Moreover, a computer-readable medium in accordance with the present invention may similarly include a front-end proxy module and a protocol engine module. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic block diagram of a communications system in accordance with the present invention. FIG. 2 is a schematic block diagram illustrating the protocol interface device of the communications system of FIG. 1 in greater detail. FIG. 3 is a schematic block diagram illustrating the extensible front-end proxy module of the protocol interface device of FIG. 2 in greater detail. FIGS. 4 and 5 are schematic block diagrams illustrating an alternate embodiment of a communications system in accordance with the invention implementing an extensible proxy architecture similar to that of FIG. 3. FIG. 6 is a schematic block diagram of an alternate embodiment of the protocol interface device of FIG. 2. FIG. 7 is a schematic block diagram further illustrating the protocol engine module of the protocol interface device of FIG. 3 and interface connector modules therefor. FIG. 8 is a schematic block diagram of an alternate embodiment of the protocol engine module and interface connector modules of FIG. 7. FIG. 9 is a schematic block diagram of still another alternate embodiment of the protocol interface device of FIG. 2. FIG. 10 is a schematic block diagram of yet another alternate embodiment of the protocol interface device of FIG. 2. FIG. 11 is a flow diagram illustrating operation of the protocol interface device of FIG. 2. FIG. 12 is a flow diagram illustrating operation of the front-end proxy module of FIG. 3. FIG. 13 is a flow diagram illustrating operation of the communications system of FIG. 5. FIG. 14 is a flow diagram illustrating operation of the protocol interface module of FIG. 6. FIG. 15 is a flow diagram illustrating operation of the protocol engine and interface connector modules of FIG. 7. FIG. 16 is a flow diagram illustrating operation of the protocol interface device of FIG. 9. FIG. 17 is a flow diagram illustrating operation of the protocol interface device of FIG. 10. FIG. 18 is a schematic block diagram of an exemplary mobile wireless communications device for use with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation and multiple prime notation are used to indicate similar elements in alternate embodiments. Turning now to FIG. 1, a communications system 10 includes a protocol interface device 14 that provides access to a plurality of data storage devices or systems 16, 18, 20. The communications system 10 illustratively includes a plurality of communications devices, namely a mobile wireless communications device 11 and a communications device 12 connected to the system via a wired connection. By way of example, various mobile wireless communications devices may be used in accordance with the invention, such as personal data assistants (PDAs), cellular telephones, etc. An exemplary mobile wireless communications device 11 suitable for use with the present invention is described in the example provided below with reference to FIG. 18. Moreover, examples of wired communications devices include personal computers, telephones, fax machines, etc. Of course, numerous wired and wireless devices may be used, although only two are shown in the exemplary embodiment for clarity of illustration. The communications devices 11, 12 typically include software clients, which are software modules or applications that operate on or in conjunction with their respective communications device to provide access to data stored at one or more of the data storage devices 16, 18, and 20 through the protocol interface device 14. Those skilled in the art will appreciate that such communications devices also include further components and/or software modules, which have not been explicitly shown in FIG. 1 for clarity of illustration. With respect to the mobile wireless communications device 11, its software client communicates with the protocol interface device 14 via a wireless communication network 13, and perhaps other networks as well (e.g., a public switched telephone network (PSTN) or the Internet), as will be appreciated by those skilled in the art. The various functions and operations of the protocol interface device 14 are preferably implemented in software operating thereon, or in conjunction therewith. The protocol interface device 14 illustratively bridges the software clients of the communications devices 11, 12 and the data storage devices 16, 18, 20. Communications between the protocol interface device 14, the communications devices 11, 12, and the data storage devices 16, 18, 20 are preferably via a wide area network (WAN) such as the Internet. That is, the communications devices 11, 12 may communicate with the protocol interface device 14 via the Internet, as noted above, and so too may the protocol interface device communicate with the data storage devices 16, 18, 20. Of course, other implementations are also contemplated. For example, the protocol interface device 14 may be implemented in a private network that also includes the data storage devices 16, 18, 20, the communications devices 11, 12, or both the data storage devices and the communications devices (e.g., in a WAN). It should be noted that the present invention is in no way limited to any particular connection or communication scheme. The data storage devices 16, 18, 20 store data to be accessed by the software clients of the communications devices 11, 12. Although some software clients are configurable to directly access certain types of data storage devices, they are often data system specific or protocol specific, as described briefly above. More particularly, on constrained electronic devices such as the mobile wireless communication device 11, processor power, memory resources, and communication channel characteristics may preclude the installation and operation of software clients having the same capabilities as those commonly used on desktop and laptop computer systems, for example. In addition, while the installation of multiple software clients for accessing data storage devices associated with different protocols is feasible for desktop and laptop computer systems, providing multiple-protocol support on such constrained devices may not be possible. The data storage devices 16, 18, 20 are accessible using different operating protocols or access schemes. As such, the protocol interface device 14 accesses the data storage devices 16, 18, 20 via an operating protocol supported by respective data storage devices, and provides data to the communications device 11, 12 via a respective client-supported operating protocol. The protocol conversion functionality of the protocol interface device 14 provides a unified approach to support access to multiple types of data system. As described in further detail below, the protocol interface device 14 provides an “any-to-any” bridge between different protocols or access schemes. The protocol interface device 14 is illustrated in further detail in FIG. 2. As noted above, the protocol interface device 14 bridges different types of communications devices with different types of data storage devices. In the illustrated embodiment, data storage devices 24, 26, 28 are systems/servers for storing electronic mail (e-mail). However, it should be noted that the present invention is not limited to mail system access. Each of the mail systems 24, 26, 28 supports a different operating protocol or access scheme. More particularly, the mail system 24 supports Outlook Web Access (OWA), the mail system 26 supports Microsoft Messaging Application Programming Interface (MAPI), and the mail system 28 supports a proprietary protocol, such as that used by America Online (AOL), for example. The protocol interface system 14 illustratively includes a front-end proxy module 30. The front-end proxy module illustratively includes proxy modules 34, 36, 38, 40 which respectively support the Wireless Application Protocol (WAP), the Post Office Protocol (POP), the Internet Message Access Protocol (IMAP), and the Hypertext Transfer Protocol (HTTP) for communication with clients. The front-end proxy 30 also communicates with a protocol engine module 32. The protocol engine module 32 translates OWA, MAPI, the proprietary protocol of the mail system 28 (and other protocols, if desired) into a format compatible with the front-end proxy module 30. To this end, a respective interface connector module may 70-77 (FIG. 7) be coupled to the protocol engine module 32 for each of the operating protocols used by the mail systems 24, 26, 28, as will be discussed further below. In a preferred embodiment, the front-end proxy module 30 and the protocol engine module 32 are extensible or expandable to accommodate additional operating protocols as they become available, as will also be discussed further below. In operation, a user accesses a mailbox on one of the mail systems 24, 26, 28 through client software on his communications device. For example, a WAP browser on a mobile wireless communication device communicates with the WAP proxy module 34 to access the mail system 24. Access commands or instructions received by the WAP proxy 34 are converted into a format compatible with the protocol engine module 32. Communications between the front-end proxy module 30 and the protocol engine module 32 are preferably achieved via a common interface protocol, which may be a proprietary protocol or an established public protocol. The protocol engine module 32 then translates the access commands or instructions received from the front-end proxy module 30 into a protocol associated with the mail system to be accessed (e.g., OWA for the mail system 24). Data received from the mail system (e.g., e-mail messages, a list of new messages, calendar appointments, tasks, etc., depending on the particular mail system), the features that its access protocol supports, and the nature of the access command are translated into the common interface protocol and transferred to the front-end proxy. The active proxy module (i.e., the WAP proxy module 34 in the present example) then formats the received data, or at least portions thereof, for the requesting client. Further commands from the client are also translated by the protocol interface device 14. Access commands from other types of clients are similarly processed. It should be noted that several mail systems may be accessed in response to a single access command, where a user has enabled multiple mailbox access through the protocol interface device 14. The protocol interface device 14 thus allows clients using different operating protocols to access the mail systems 24, 26, 28, which also use different operating protocols. Access commands such as move, delete, create, send, fetch, and view, for example, that are generated at a client affect the data stored at the mail systems 24, 26, 28 instead of copies of the data. Through the protocol interface device 14, a client compatible with any one of the proxy modules 34, 36, 38, 40 is provided access to one or more of the mail systems 24, 26, 28. The client itself advantageously need not support the access protocol or scheme associated with the mail system(s) to be accessed. Since the mail system protocol and the client protocol need not be compatible, feature support between the protocols may be different. For example, a POP client does not support the same features as OWA. The interface protocol used between the protocol engine module 32 and the front-end proxy module 30 is preferably designed to be able to represent a desired number of protocol-supported elements or features for a desired operating protocol. More specifically, the common interface protocol is preferably able to represent all protocol-supported elements for the most “capable” protocol (OWA in the present example), to provide the broadest possible feature support. Further still, the common interface protocol may support a full feature set across all supported protocols, if desired. By way of example, the common interface protocol may be a proprietary protocol based on the Web-based Distributed Authoring and Versioning (WebDAV) protocol. An example of an authentication request using such a common interface protocol is provided as program listing #1, below. This exemplary authentication request routine allows the protocol interface device 14 to be authenticated by a mail system using a user identifier and password provided by a user, and it also retrieves a root folder and basic capabilities of a target mailbox on the mail system. An exemplary inbox request in accordance with a WebDAV-based common interface protocol is set forth below as program listing #2. In accordance with this routine, responsive to an inbox request, the capabilities of the inbox in a target mailbox are queried, and then its contents are queried. Another example is provided below as program listing #3, which is for a folder search request in accordance with the aforementioned WebDAV-based common interface protocol. Here, a list of subfolders for a given folder is returned in response to this request. It will be appreciated by those skilled in the art that numerous other requests and operations may be used as well. It should be noted that the software clients need not initiate data access requests in all embodiments. For example, in some embodiments the protocol interface device 14 may include (or communicate with) a polling or aggregation engine module (not shown) that prompts the protocol engine module 32 to aggregate messages for respective users from the mail systems 24, 26, 28 at predetermined intervals, as will be appreciated by those skilled in the art. The protocol engine module 14 would then cooperate with the front-end proxy module 30 to provide the aggregated messages to the respective software clients, as described above. Additionally, the front-end proxy module 30 need not communicate directly with the communications devices 11, 12 in all embodiments, but it may instead communicate therewith via an intervening mail system or server, for example. Thus, in the case where an aggregation engine module is used, the aggregated messages may be first transferred by the front-end proxy module 30 to an intervening mail server, which in turn provides the messages to the appropriate communications device, as will also be appreciated by those skilled in the art. Here again, the front-end proxy module 30 would use the appropriate protocol(s) supported by such intervening mail server for communicating therewith. A method for providing access to a plurality of data storage devices, such as the mail systems 24, 26, 28, using the protocol interface system 14 is illustrated in FIG. 11. Beginning at Block 110, an access command or data is first received, at Block 111. The access command or data is translated into the common interface protocol, at Block 112. An access command is then translated (Block 113) into a data system protocol associated with the data system to be accessed, such as OWA for the mail system 24, for example. On the other hand, data is translated into the client protocol, at Block 113. Depending upon the particular features supported by the client protocol, only those portions of the data corresponding to elements of the interface protocol that are supported by the client protocol are translated during this step. The protocol interface device 14 may generate an error responsive to a non-supported operating protocol. More particularly, non-supported interface protocol elements are preferably ignored or processed according to a default or error-processing scheme. Translated access commands or data are then transferred to a data system or a client, at Block 114, thus concluding the illustrated method (Block 115). Turning now additionally to FIG. 3, an exemplary embodiment of the front-end proxy module 30 is now described. The front-end proxy module 30 illustratively includes the proxy modules 34, 36, 38, 40, a renderer module 44, an extensible stylesheet language transformations (XSLT) engine module 46, a memory or template store 48, a flow controller module 50, and handlers 52a-52n. As noted above, each proxy module 34, 36, 38, 40 effectively “fronts” the protocol engine module 32 and translates respective operating protocols for different client types. For example, a WAP proxy module provides information retrieved from one or more of the handlers 52a-52n in the form of WML documents targeted for display on devices such as cell phones and PDAs. A POP proxy makes use of at least some of the same proxy components, including the flow controller module 50 and the renderer module 44 to render data in the form required by the POP protocol. One particularly advantageous benefit of the illustrated front-end proxy module 30 is that each proxy module 34, 36, 38, 40 makes use of the same core services to route traffic, access data, and render data. In other words, the renderer module 44, XSLT engine module 46, template memory 48, flow controller module 50, and handlers 52a-52n provide a common core service module for the proxy modules 34, 36, 38, 40. The only differences between translations by the different proxy modules 34, 36, 38, 40 would be in the configuration of the flow controller 50, the handlers 52a-52n, and the XSL templates used to translate the data into its final form. It many cases, the same handlers 52a-52n will be re-used between by the various proxy modules 34, 36, 38, 40, as will be appreciated by those skilled in the art. During operation, a data access request from a client is passed to the appropriate proxy module 34, 36, 38, 40 using standard mechanisms for the client protocol. For a WAP client, for example, parameters are passed via a query string and/or form variables. The WAP proxy module 34 determines a component identifier (which identifies a target item such as a mail folder), an action identifier (which identifies an action to be performed), and any parameters based on data in the request. In the case of WAP, the component and action identifiers are passed in the query string or form. Other parameters in the query string or form are packaged into a parameter list. The active proxy module then calls the flow controller 50, passing along the identifiers and parameter list. The flow controller looks up the appropriate handler via the component and action identifiers and constructs the handler, passing the parameters as arguments to a constructor (not shown). Using the handler 52a as an example, this handler would processes the request, using a data layer (FIG. 5) to gather information needed for a response. For mail system access, for instance, the data layer communicates with the protocol engine module 32 for any information related to the contents of the user's mailbox, calendar, or address book, for example. Communications with other components may be established for different types of information, such as information related to authentication services and a user's e-mail account. The handler 52a then decides whether the request should be forwarded to another handler, or if its results should be rendered. All information passed back by the handlers 52a-52n is preferably in a common format, such as org.xml.sax.InputSource, for example, a provider of extensible mark-up language (XML) data. The active proxy module then calls the renderer module 44, passing along the InputSource, locale information, the name of the template to be rendered, and an OutputStream. The renderer module 44, making use of the XSLT engine 46, renders the page into the OutputStream. The OutputStream is then provided to the client by the active proxy module using the client protocol. The above system provides a generic application framework following the classic model/view/controller (MVC) architecture that implements most of the application infrastructure. One important feature is that a base set of functionality may be defined for similar services and then extended to provide the service-specific functionality required to fully implement a given service. Within a given implementation, the flow controller 50, the handlers 52a-52n, and/or the data access layer are fully extensible or replaceable. With this in mind, supporting a brand new service simply involves defining and implementing the data layer, defining the control flow and discrete actions within the system (i.e., the flow controller module 50), and defining and implementing the interface with the service (i.e., the renderer module 44). On the other hand, supporting a new type of client with an existing service involves making minor changes to, and extending actions within, the flow controller module 50 and handlers 52a-52n to support additional client-required functionality, and defining and implementing the interface between the client and the system (i.e., the renderer module 44). Operation of the front-end proxy module 30 to perform protocol translation is further described with respect to the block diagram of FIG. 12. Certain of the illustrated operations have been described in detail above, and thus will be described only briefly below to avoid undue repetition. Beginning at Block 120, an access request or command is received at a proxy module 34, 36, 38, 40, at Block 121. The access request is translated into the common interface protocol by one or more of the handlers 52a-52n, at Block 122. Data is received from a given mail system 24, 26, 28 in response to the request, at Block 123. This data, which has already been translated into the common interface protocol by the protocol engine module 32, is rendered (Block 124) and returned to the client, at Block 125, thus concluding the illustrated method (Block 126). Depending upon the particular features supported by the client protocol, only portions of the data corresponding to elements of the common interface protocol that are supported by the client protocol are rendered or translated. Non-supported interface protocol elements may be ignored or processed according to a default or error processing scheme, as noted above. It should be noted that the extensible, common core service architecture of the front-end proxy module 30 may also be used for a variety of applications. One such application is to address various shortcomings of the disparate methods used to respond to HTTP requests from a Web application. Referring now to FIGS. 4 and 5, a Web data access system 100 having an extensible architecture in accordance with the present invention is now described. The components of the Web data access system 100 communicate bi-directionally, and they illustratively include a user request 101, a Web server 102, a proxy server 104, and an extensible controller system 106. More particularly, the user request 101 refers to a user using a web browser or web application to request a web page (e.g., from a PDA or personal computer). Once the request is made, the Web server 102 processes the request. The proxy server 104 assists the Web server 102 in processing the request. For comparison purposes, the proxy server 104 here functions similar to the protocol interface device 14 discussed above, and the extensible controller system 106 would be implemented as a software module that is run on or in conjunction with the proxy server, as will be appreciated by those skilled in the art. Of course, in some embodiments the proxy server 104 and extensible controller system 106 could be implemented in different physical devices or servers, for example. The proxy server 104 provides a process of providing cached or storage items available on other servers which are slower or more resource intensive to access. The proxy server 104 accepts URLs with a special prefix. When it receives a request for such a URL, it strips off the prefix and looks for the resulting URL in its local cache. If found, it returns the document immediately, otherwise it fetches it from the remote server, saves a copy in the cache, and returns it to the requester. The pages returned by the proxy server 104 can be either static or dynamic in nature. The proxy server 104 may communicate with application servers or data servers, and in this specific embodiment, the extensible controller system 106. More particularly, the components of the proxy server 104 illustratively include an aggregate server 202, a renderer module 212, an XSLT engine module 214, and a memory 216 for storing a series of templates, similar to those described above. The components of the extensible controller system 106 include an action map 204, and a series of handlers 206, also similar to those discussed above. The aggregate server 202 performs the processing of incoming information and passes it onto other components for assistance. The renderer module 212 renders the resultant data into a viewable format. The renderer module 212 makes use of the XSLT engine module 214 and any necessary templates from the memory 216 to render the page. The aggregate server 202 sends data to the action map 204, which maintains the control flow and handles the business logic in the system. The action map 204 interacts with a series of handlers 206. The handler 206 utilizes the data layer 208 to retrieve information from other data sources 210. The other data sources 210 may include, for example, XML for web data, a universal proxy for any information related to the contents of user applications (e.g., e-mail, calendar or contact), or a provisioning API for authentication services and data relating to a user account. The system functions by having a user send in a URL as a user request 101. This request is received at the Web server 102, which passes on to the proxy server 104 for processing using standard mechanisms for the protocol. For example, a WML request would pass a WAP parameter query string and/or form variables. The aggregate server 202 component of the proxy server 104 determines the component ID, action ID and any parameters based on data in the request. Using the same WAP example, the component and action IDs are passed in the query string or form. All other parameters in the query string or form are packaged up into a parameter list. The aggregate server 202 then calls the action map 204 of the extensible controller system 106 and passes along the IDs and parameter list. The action map 204 looks up the appropriate handler 206 via the component and action IDs and constructs the handler, passing the parameters as arguments to the constructor. The handler 206 processes the request, using the data layer 208 to gather information needed for a response. The data layer 208 will retrieve information from other data sources 210 located within the network or external to the network. The handler 206 then decides whether the request should be forwarded to another handler 206, or if its results should be rendered. If the system decides to render the data, the data is passed from the handler 206, back to the action map 204, and back to aggregate server 202 of the proxy server 104. The aggregate server 202 then calls the renderer module 212, which invokes the XSLT engine module 214 and any necessary templates to render the data into a viewable output. This output is then returned to the Web server 102 to serve the data as a viewable web page as a result of the user request 101. The various steps involved in processing Web data using the extensible controller system 106 will now be further described with reference to FIG. 13. More particularly, this diagram illustrates in greater detail the processing and interaction of the proxy server 104 and the extensible controller system 106. The system flow begins with a user request 101. This request is sent to the Web server 102, which passes the information to the proxy server 104 for processing. The proxy server 104 invokes the aggregate server 202 for processing. The aggregate server 202 determines whether a context is available, at Block 302. If it is available, the system will move to the next step to mine the IDs (Block 306). If it is not available, the system will first create the context, at Block 304, and then continue onto the step to mine the IDs, at Block 306. The action ID and component ID are also mined out of the system. These IDs, along with the request parameters and any form data, are packaged into an envelope and gathered together, at Block 308. An invoke procedure is called to pass the data from the aggregate server 202 to the action map 204 of the extensible controller system 106. This invoke procedure will pass information pertaining to the envelope, an action code, the component ID and context info to the action map 204. The action map 204 looks up the action, at Block 310, and determines whether the action exists, at Block 312. If it does, then it moves to the next step to determine whether the action requires authentication, at Block 316. If the action does not exist, the system retrieves the default action, at Block 314, and then determines whether the action requires authentication, at Block 316. At this point, if the action does not require authentication, the system determines if any requests are pending, at Block 320. If the action does require authentication, the system then determines whether the context is in an authenticated state, at Block 318. If the context is in an authenticated state, the system then determines whether a request is pending, at Block 320. However, if the context is not in an authenticated state, the system returns the request to the retrieve default action, at Block 314, until authentication is accepted. At Block 320, the system determines if a request is pending. If a request is pending, the system executes on the pending request and jumps to next stage, determining whether a process is in queue, at Block 346. If no request is pending, the system executes on the action and validates on the envelope data, at Block 322, and passes control to the handler 206 to create the action handler, at Block 324. Once the action handler is created, it is initialized, at Block 326. The system then determines whether background processing is allowed, at Block 328. If so, a background handler is created, at Block 344, and the system determines whether a process is in queue, at Block 346. However, if background processing is not allowed, the system then processes the action handler, at Block 330, and then returns the result, at Block 332. Revisiting the system, at Block 346 the system determines whether a process is in the queue. If the process is in the queue, it then determines whether the action is complete, at Block 350. If the process is not in the queue, then it submits it to the queue, at Block 348, and then determines whether the action handler is complete, at Block 350. If the action handler is complete, the system returns the action handler result, at Block 352. If the action handler is not complete, the system returns the pending render result, at Block 354. The output of the steps illustrated at Blocks 352 and 354 (returning either an action handler result or pending renderer result) will be used to determine whether to render the result, at Block 334. More particularly, the results of the steps illustrated at Blocks 332 (return result), 352 (return action handler result) and 354 (return pending render result) are used to determine whether to render the result (Block 334). If the system decides to render the result, the system sends the data from the extensible controller system 106 to the proxy server 404 and renders the data, at Block 340, at the renderer module 212. The data is then passed onto the Web server 102 to display the result, at Block 342, as a response to the user request 101. However, if the system decides not to render the result and has instead decided to forward the request to another action handler for processing, the system retrieves the ID keys, at Block 336, retrieves the envelope data, at Block 338, and then looks up the appropriate action, at Block 310. The system will loop around at this point until a decision to render a result is ultimately accepted, at Block 334. The above-described method involves using a single source for defining the components within the system. In this particular embodiment, the source is an XML file, but other formats could be used as well, as will be appreciated by those skilled in the art. This source would define the code that handles the request, the URL syntax and parameters, templates or code used to generate the response for the request, and the routing information for the request, for example. The code that handles the request, along with the parameter definition, is used by the system to create the action handler, pass the correctly typed parameters, and pass control to it for processing. The parameters include type information allowing for strongly typed data. The parameters may also be defined as optional or required. The template or templates are used to generate the response for the request. If an attempt is made to generate a response other than to what was defined an error is generated. The source would also define the routing information for the request. Often times, it is desirable for a handler to perform work within its scope and then hand off control to another handler to allow it to perform its work. However, if the handler attempts to hand control to something not defined in the source, an error is generated. Other variations are also possible. For example, the source may be used whenever generating URL's for use within the system. Moreover, request routing may be separated from the actual processing of those requests. Control flow is then handled by one component of the system, not by each handler. The handler would then simply ask the controller to forward a request to another handler. Thus, incoming data may be kept in a known state for the life of a particular request. Yet another approach involves enforcing control flow through the system where one handler does not call another handler directly to do its work. Still another approach involves keeping the handlers relatively small and simple. That is, this will limit the handler's purpose and scope to receiving requests and calling the appropriate business logic to gather the desired results. Another variation involves keeping each handler focused on one task, and upon completion of the task, allowing the results to be rendered or forwarded on to the next handler. A further variation involves providing an extensible mechanism for handling requests that can handle immediate needs, as well as grow over time without becoming overly complex. When loading the system, the user is able to specify a primary and secondary action map. In this way, generic business logic and control flow may be specified by the primary action map while still providing the user with a method of adding or modifying the functionality. Another approach is to provide the developer with a generic mechanism for responding quickly to long running requests to avoid generating a timeout. This enables the developer to specify background processing at either a handler level, or at the entire system. The above-described extensible controller is particularly advantageous for addressing shortcomings in Web or HTTP-based applications. Of course, it will be also appreciated by those skilled in the art that this same architecture may be extended to support other types of non-HTTP based applications as well. Turning now to FIG. 6, an alternate embodiment of the protocol interface device 14′ is now described. In the illustrated embodiment, all requests to a data storage device, such as the mail systems 24′, 26′, 28′, are defined in configuration files stored in a configuration file store or memory 31′. In this way, for a given client category, an application developer can easily request only those properties required to support the client for which it was written. A resource manager, which may be part of the front-end proxy module 30′ or a separate component of the protocol interface device 14′, advantageously allows a user to specify a primary and secondary set of configuration files. If a secondary configuration file is specified, any resources defined in it will override those specified in the primary configuration file. This allows the user to specify a core set of resources and then tweak them to fit a particular implementation. Moreover, configuration files may be stored for processing operations at different network layers. For example, configuration files for data layer operations for interfacing the front-end proxy module 30′ and protocol engine module 32′ may be stored in the memory 31′, as well for upper network layer operations performed by the flow controller module 50, for example. Other types of configurations files may be used as well, as will be appreciated by those skilled in the art. A configuration file also preferably specifies the implementation class that is created to handle the response to a given request. This makes it a simple matter to slightly change the behavior of an object in a data model, or even completely replace it. Caching behavior and strength for each request may also be specified in a configuration file. With a combination of these two properties, a developer can have much greater control over memory consumption and response/request performance. In addition, configuration files also allow a user to specify multiple requests for a given resource. This makes it possible to support data systems with different request/response formats. An exemplary configuration file is provided below as program listing #4. This configuration file is suitable for a data store that supports a WebDAV interface, as discussed above, or in the case of the protocol interface device 14′, a protocol engine that supports a WebDAV interface. However, it could be used for other types interfaces/data stores as well. It should also be noted that, in addition to the content class specified for the resource, a user may also specify a command to further identify a given resource. This allows the user to perform multiple different operations on a given resource type, as will be appreciated by those skilled in the art. Operation of the protocol interface device 14′ using configuration files will now be described further with reference to FIG. 14. Beginning at Block 140, an access request or command is received at a proxy module, at Block 141. The access request is translated into the common interface protocol by a handler 52a-52n, at Block 142, with reference to one or more configuration files. Data that is received from the data system (Block 143) in response to the request, and which has already been translated into the common interface protocol by the protocol engine module 32′, is formatted into a response and rendered, at Block 144. Again, this is done with reference to one or more configuration files. The rendered response is then returned to the client (Block 145), thus concluding the illustrated methods, at Block 146. Referring now additionally to FIG. 7, the protocol engine module 32 will now be described in further detail. The protocol engine module 32 provides a framework to incorporate various interface connector modules 70-77 that communicate with various mail systems using different protocols. The protocol engine module 32 also provides a common interface XML and WebDAV, for example, that the clients, through the front-end proxy module 30, use to access various mail accounts. Common operations like retrieving only the essential headers of new mail and determining the presence and size of attachments without downloading them are highly efficient. All operations are performed directly on the source, and only the essential data is retrieved. The protocol engine module 32 uses an appropriate one of a plurality of interface connector modules 70-77 to access a mail account. All of the connector modules 70-77 preferably support a common application programming interface (API), such that adapting the protocol engine module 32 to support a new protocol amounts to simply adding a new interface connector module. The connector modules 70-77 may be written in Java, for example, although other suitable languages or protocols may also be used. Overall system performance and availability may be improved, for example, by providing multiple dynamically load-balanced protocol engine machines. Results received by the protocol engine module 32 from the mail systems 24, 26, 28 are similarly translated into the common interface protocol for translation into a client-supported protocol, if necessary, and transmission to a client. The results communicated back to a client preferably include only data that was requested by the client. Data corresponding to features that are supported by a mail system protocol but not by a client protocol may be translated into the common interface protocol, but it may also be ignored or handled according to a default or error processing scheme, as noted above. A method of protocol translation using the protocol engine module 32 and interface connector modules 71-77 is now described with reference to FIG. 15. Beginning at Block 150, an access request or command is received, at Block 151. The access request is translated into a protocol supported by the target data system, at Block 152. Data is received from the data system in response to the request, at Block 153, and it is translated into the common interface protocol, at Block 154. Further translation of the data into a client protocol may be performed, if necessary, at Block 155, and the data transmitted to the client at Block 156, thus concluding the illustrated method, at Block 157. Again, depending upon the particular features supported by the client protocol, only portions of the data corresponding to elements of the common interface protocol that are supported by the client protocol are translated. As described above, non-supported interface protocol elements may be ignored or processed according to a default or error processing scheme. Turning now to FIG. 8, an alternate embodiment of the above-described protocol conversion module architecture is now described. Here, the protocol engine module 32 takes the form of a universal proxy (UP) servlet module 80, and each interface connector module 81, 82, 83 and a respective provider module 84, 85, 86 are associated with different operating protocols. In the illustrated example, the different protocols are OWA, IMAP, and POP. Further or different protocols may be supported by corresponding provider/connection pairs, as will be appreciated by those skilled in the art. For a common interface protocol, such as the proprietary interface protocol described above, the UP servlet module 80 takes incoming common format requests and translates them into calls, using the defined interfaces, to the interface connector modules 81-83. The UP servlet module 80 also takes the results of these calls and formats them into common format requests. Each common format request includes a method request and a path in the form of a URL. It may also include an XML document that provides additional parameters for the request. Conceptually, below the UP servlet module 80 there is a provider module 84-86 for each supported mail system protocol. The providers take care of handling the calls made by the UP servlet module 80. As shown, each provider has a connection, which takes care of communicating with the source mailbox/account on a target mail system. Initially, the connection will also be the provider. The interfaces used by the UP servlet 80 and implemented by the provider modules 84-86 define a loose folder hierarchy. In fact, it may be conceptualized as a collection of collections of items. An item can be a message, a folder, or a contact, for example, or any other data item to be represented. Each item has a defined type (e.g., mail, contact, appointment). An interface for each type of item defines the properties and actions that are available for that type of item. A folder item includes a collection of items, and provides methods to enumerate the items within a folder. The connector interface modules 81-83 provide a common way for the UP servlet module 80 to communicate with different provider modules/interface connector modules. Some connector modules may only implement a subset of the protocol and/or may only support a single folder (collection) of items, as in the case of POP. The basic flow for an exemplary common format request proceeds as follows. The UP servlet module 80 receives the request, and it either retrieves or creates the appropriate provider/connection. The UP servlet module 80 then calls an appropriate “get folder” or similar function associated with the interface connector module, passing a target mail system identifier, such as a URL that was included in the common format request. The interface connection module returns a reference to some object that implements the folder interface and represents the requested folder. In its simplest implementation (e.g., POP), a single object could be the interface connector module and also represent the mailbox folder. The UP servlet module 80 uses the returned folder reference to make additional calls to satisfy the common format request. For example, if the UP servlet module 80 needs to retrieve a specific item, it may first call a “get folder” function, passing the requested URL, and after it has the folder, it will then call a “get item” function, again passing the URL. The results of the call(s) are then formatted into an appropriate format, such as XML, and returned in an HTTP response. It will be up to the provider module/interface connection module to interpret a URL passed in and return the appropriate reference. This will not be complicated because the provider module/interface connection module provides the URLs in the first place. The only URL that any interface connection module will be required to know about is “\”. All other URLs are generated by the provider/connection. As long as the URLs within the hierarchy/collections are unique, the provider will be able to resolve to the correct item when a “get” function is called. The provider modules 84-86 and interface connection modules 81-83 preferably support a root folder. If only a root folder is supported, then inbox, calendar, and contact items (as appropriate) should be items within that folder if they are to be accessible through a protocol engine. In accordance with one aspect of the invention, a single, advantageous mechanism to access various types of protocols is provided. This mechanism supports the full functionality of each data system protocol for similarly capable client protocols, and degrades when a specific data system protocol feature is not supported by a client protocol. Requests received in a common format are translated into a provider/protocol specific format before forwarding the request on to the destination server. Responses from the destination server, which are in provider/protocol specific format, are translated back into the common format. A mechanism for a client to query supported functionality for a specific provider module, giving the client greater control over how it generates requests to the provider, is also provided. Any client written to support the common protocol format, directly or through a proxy, can easily provide access to any mail store without concerning itself with the details of the mail store provider module/protocol. Referring now additionally to FIG. 9, another embodiment of the protocol interface device 14″ is now described. Here, user e-mail account information associated with e-mail accounts to be accessed through the protocol interface device 14″ is stored in a data store 90″. The per-account information preferably includes an indication of the access protocols supported for each e-mail account. Records in the data store 90″ may be arranged by an account identifier, such as an e-mail address, or by a user name associated with the protocol interface device 14″ such that all e-mail account information for particular users is grouped in the data store 90″, for example. Where access protocol support is the same for all e-mail accounts on each of the mail systems 24″, 26″, the per-account information may include mail system information indicating the operating protocols supported by each mail system. A data store 91″ stores a list of all operating protocols supported by the protocol engine module 32″, and corresponding metrics (i.e., ranking) representing protocol preferences. These metrics are calculated based on capability criteria, such as the degree to which features of each mail system 24″, 26″ are supported by a protocol and the security level of a protocol, for example. Other criteria may also be used and will be apparent to those skilled in the art. In the data store 91″, OWA would typically have a higher metric or ranking than MAPI, and IMAP would generally be ranked higher than POP. Each of the data stores 90″, 91″ may be implemented, for example, in a database on a local hard disk or other memory at the protocol interface device 14″, or on a file server with which the protocol interface device communicates. The protocol engine module 32″ determines to which mailbox(es) or account(s) the command or instruction relates, and then accesses the per-account information in the data store 90″ to determine whether more than one access protocol is supported for each account to be accessed. If only one access protocol is supported, then that protocol is selected. Where more than one access protocol is supported for the account, then the protocol engine module 32″ accesses the data store 91″ to determine which supported protocol is preferred or desired, and the supported protocol with the highest metric or ranking is selected. For the mail system 24″, OWA is preferably selected over MAPI, and for the mail system 26″, IMAP is preferably selected over POP. The protocol interface device 14″ thus allows access to the mail systems 24″, 26″ using a most capable supported protocol. Through the protocol interface device 14″, a client compatible with any of the proxy modules 34″, 36″, 38″, 40″ is provided access to one or more of the mail systems 24″, 26″. The client itself need not support the access protocol or scheme associated with the mail system(s) to be accessed. A method of data system access protocol selection using the protocol interface device 14″ is now described with reference to FIG. 9. Beginning at Block 160, an access command is received from a client at Block 161. A determination is made (Block 162) as to whether each data system to be accessed in response to the command supports more than one access protocol. If so, then the most capable supported protocol is selected, at Block 164. Otherwise, the one supported protocol is selected, at Block 163. Each data system is accessed using the selected protocol, at Block 165, thus concluding the illustrated method, at Block 166. Where more than one data system is to be accessed, the protocol selection steps illustrated at Blocks 162-164 are preferably repeated for each data system. It should be noted that the protocol and metric data store 91″ is but one example exemplary of a protocol preference ranking technique that may be used in accordance with the present invention. Protocol preferences may be inherent in the ordering of a list of supported protocols, for example. Further criteria than metrics or overall preferences may also be considered when selecting a protocol. The type of client from which the access command is received may also affect protocol selection. Where the access command is received from a POP client, for example, many of the enhanced features supported by OWA cannot be represented in POP for transfer to the device. If a user has only one type of client for accessing the protocol interface device 14″, then the per-account information may be adapted to reflect the type of client or to limit the list of supported protocol based on the type of client. Otherwise, a further step in protocol selection may be to determine the type of client from which an access request is received. Alternatively, a most capable protocol supported by a data system to be accessed may always be selected, and any incompatibility between the selected access protocol and the protocol supported by the client is handled during translation of data to the client protocol. Portions of data corresponding to elements of the interface protocol that are supported by the client protocol are translated, whereas non-supported interface protocol elements are ignored or processed according to a default or error processing scheme. Generally speaking, clients often access servers through proxies. Also, the latency is often positively correlated to the cardinality of the collection being accessed (e.g., number of email messages in the mailbox being accessed). As will be evident from the following description, the present invention provides an apparatus and technique that may be used by the proxy to give the client the illusion that the collection being accessed is smaller than it really is. For example, a proxy may show only the 100 most recent messages in a mailbox, while the mailbox itself has 2000+messages. The present invention advantageously allows this proxy to select a small subset of the collection that can be presented to the client in lieu of the entire collection without a significant impact to the user experience. More particularly, turning now to FIG. 10, another advantageous embodiment of the protocol interface device 14″′ is now described. Generally speaking, when a data access request is received from a client, the protocol interface device 14″′ accesses one or more of the data systems 24″′, 26″′. However, in some cases accessing the data systems and providing a response to the client might otherwise cause timeouts for certain client protocols, and longer than desired wait times for a user of a client after a request has been sent. Yet, in accordance with the present aspect of the invention, certain data may be stored at the protocol interface device 14″′ which may be used to reduce response times. More particularly, the protocol engine module 32″′ polls the data systems 24″′, 26″′ to determine whether they currently store data items associated with users that have been configured for access thereof. Users are configured in the protocol interface device 14″′ by establishing a user account associated therewith, for example. Polling is preferably performed in accordance with a polling interval. The polling interface may be a static predetermined polling interval, or an adaptive polling interval that can be adjusted based on operating conditions or the occurrence of particular events, as will be appreciated by those skilled in the art. In response to a poll from the protocol engine module 32″′, a given data system 24″′, 26″′ returns data items, or at least data item identifiers that can be used to retrieve the data items, to the protocol interface device 14″′. These data items or identifiers are then stored by the protocol engine module 32″′ in the data store or memory 92″′. In particular, the protocol engine module 32″′ may determine whether new data items for a user are stored in any of the data systems 24″′, 26″′. Where the data systems 24″′, 26″′ are e-mail systems, for example, the protocol engine module 32″′ queries mailboxes associated with each user configured for e-mail access through the protocol interface device 14″′. For each mailbox query, a mail system returns, at a minimum, a list of unique identifiers (UIDs) associated with e-mail messages stored in the mailbox. A current UID list is then compared with a previous UID list for the mailbox in the UID store 92″′ to determine whether new messages have been stored in the mailbox at the mail system. If new messages are detected, an alert is preferably sent to a user's client by the protocol engine module 32″′ in cooperation with the front-end proxy module 30″′ (or another component of the protocol interface device 14″′), and the current UID list including the new messages is stored to the UID store 92″′. One of the most common data access operations is viewing a listing of data items currently stored at data systems, especially where the data items are messages stored on mail systems. As described above, the protocol engine module 32″′ polls one or more of the data systems 24″′, 26″′ to detect new data items based on a list of UIDs stored in the UID store 92″′. Therefore, the protocol interface device 14″′ has a local listing of UIDs of data items that were stored at the data systems 24″′, 26″′ the last time the data systems were polled. In accordance with the present aspect of the invention, the protocol engine module 32″′ retrieves the stored UID list from the UID store 92″′ when a “view items” or similar access request is received. This stored UID list, which is accurate to within the current polling interval, is then returned to the requesting client. This provides a much faster response time than accessing the data systems 24″′, 26″′ when the request is received, as will be appreciated by those skilled in the art. In the case of a POP client, for example, the client times out if no response to a request is received within 30 seconds. Where the POP client is operating on a mobile wireless communications device, latency within the wireless communications network can cause delays that are significant relative to this limited response time. The faster response time associated with providing a stored UID list in response to a data access request is particularly advantageous in these types of scenarios. Even in the absence of such time constraints, a faster response time enhances the user experience at a client by reducing the wait time between sending a data access request and receiving a response. As described above, the stored UID list is accurate to within the polling interval. When the stored UID list is provided to a client in response to a data access request, the protocol engine module 32″′ preferably polls the data system(s) 24″′, 26″′ to determine whether the stored UID list is still accurate. If new items have been stored at the data system(s) 24″′, 26″′ since the last poll, then a new UID list is sent to the client. This further polling of the data systems 24″′, 26″′ is performed either according to the polling interval or initiated by the data access request. It will be appreciated that the preceding description relates to “view items” or similar data access requests. Other types of data access requests may be processed by other components or modules of the protocol interface device 14″′. For example, such data access requests are translated, if necessary, by the front-end proxy module 30″′, as described above. The protocol interface device 14″′ thereby allows access to the data systems 24″′, 26″′, and provides for reduced response times for various types of data access requests. Through the protocol interface device 14″′, a client compatible with any of the protocols handled by the front-end proxy module 30″′ is provided access to one or more of the data systems 24″′, 26″′. The client itself need not support the access protocol or scheme associated with the data system(s) 24″′, 26″′ to be accessed, as noted above. A method of reducing response times for data system access requests using the protocol interface device 14″′ is now described with respect to FIG. 17. Beginning at Block 170, a data access request is received at Block 171. A determination is then made, at Block 172, as to whether data pertinent to the data access request (i.e., a UID list) is locally stored. Where such data is in a local store 92″′, then the stored data is provided to the requesting client, at Block 173. After the stored data has been transmitted to the client, or if no such data has been stored, the data system(s) 24″′, 26″′ to which the data access request relates is polled, at Block 174. An optional step of determining whether the polled data received in response to a poll is different from the stored data may then be performed at Block 175. If so, this means that there is new data stored on the data system(s) 24″′, 26″′, and the data received in response to the poll is provided to the client, at Block 176. It is also locally stored in the data store 92″′, at Block 177, thus concluding the illustrated method (Block 178). By way of example, data access systems and methods according to aspects of the invention may be applied to other types of data storage devices than mail systems, and other protocols and access schemes than those specifically described above and shown in the drawings. Additional features of the invention may be found in co-pending applications entitled COMMUNICATIONS SYSTEM PROVIDING REDUCED ACCESS LATENCY AND RELATED METHODS, attorney docket number ID-494; COMMUNICATIONS SYSTEM INCLUDING PROTOCOL INTERFACE FOR MULTIPLE OPERATING PROTOCOLS AND RELATED METHODS, attorney docket number ID-493; COMMUNICATIONS SYSTEM PROVIDING EXTENSIBLE PROTOCOL TRANSLATION FEATURES AND RELATED METHODS, attorney docket number ID-507; COMMUNICATIONS SYSTEM PROVIDING MULTI-LAYERED EXTENSIBLE PROTOCOL INTERFACE AND RELATED METHODS, attorney docket number ID-503; COMMUNICATIONS SYSTEM PROVIDING EXTENSIBLE PROTOCOL TRANSLATION AND CONFIGURATION FEATURES AND RELATED METHODS, attorney docket number ID-502; and COMMUNICATIONS SYSTEM INCLUDING PROTOCOL INTERFACE DEVICE PROVIDING ENHANCED OPERATING PROTOCOL SELECTION FEATURES AND RELATED METHODS, attorney docket number ID-495, the entire disclosures of which are hereby incorporated herein by reference. EXAMPLE An exemplary hand-held mobile wireless communications device 1000 that can be used in the present invention is further described in the example below with reference to FIG. 18. The device 1000 includes a housing 1200, a keyboard 1400 and an output device 1600. The output device shown is a display 1600, which is preferably a full graphic LCD. Other types of output devices may alternatively be utilized. A processing device 1800 is contained within the housing 1200 and is coupled between the keyboard 1400 and the display 1600. The processing device 1800 controls the operation of the display 1600, as well as the overall operation of the mobile device 1000, in response to actuation of keys on the keyboard 1400 by the user. The housing 1200 may be elongated vertically, or may take on other sizes and shapes (including clamshell housing structures). The keyboard may include a mode selection key, or other hardware or software for switching between text entry and telephony entry. In addition to the processing device 1800, other parts of the mobile device 1000 are shown schematically in FIG. 18. These include a communications subsystem 1001; a short-range communications subsystem 1020; the keyboard 1400 and the display 1600, along with other input/output devices 1060, 1080, 1100 and 1120; as well as memory devices 1160, 1180 and various other device subsystems 1201. The mobile device 1000 is preferably a two-way RF communications device having voice and data communications capabilities. In addition, the mobile device 1000 preferably has the capability to communicate with other computer systems via the Internet. Operating system software executed by the processing device 1800 is preferably stored in a persistent store, such as the flash memory 1160, but may be stored in other types of memory devices, such as a read only memory (ROM) or similar storage element. In addition, system software, specific device applications, or parts thereof, may be temporarily loaded into a volatile store, such as the random access memory (RAM) 1180. Communications signals received by the mobile device may also be stored in the RAM 1180. The processing device 1800, in addition to its operating system functions, enables execution of software applications 1300A-1300N on the device 1000. A predetermined set of applications that control basic device operations, such as data and voice communications 1300A and 1300B, may be installed on the device 1000 during manufacture. In addition, a personal information manager (PIM) application may be installed during manufacture. The PIM is preferably capable of organizing and managing data items, such as e-mail, calendar events, voice mails, appointments, and task items. The PIM application is also preferably capable of sending and receiving data items via a wireless network 1401. Preferably, the PIM data items are seamlessly integrated, synchronized and updated via the wireless network 1401 with the device user's corresponding data items stored or associated with a host computer system. Communication functions, including data and voice communications, are performed through the communications subsystem 1001, and possibly through the short-range communications subsystem. The communications subsystem 1001 includes a receiver 1500, a transmitter 1520, and one or more antennas 1540 and 1560. In addition, the communications subsystem 1001 also includes a processing module, such as a digital signal processor (DSP) 1580, and local oscillators (LOs) 1601. The specific design and implementation of the communications subsystem 1001 is dependent upon the communications network in which the mobile device 1000 is intended to operate. For example, a mobile device 1000 may include a communications subsystem 1001 designed to operate with the Mobitex™, Data TAC™ or General Packet Radio Service (GPRS) mobile data communications networks, and also designed to operate with any of a variety of voice communications networks, such as AMPS, TDMA, CDMA, PCS, GSM, etc. Other types of data and voice networks, both separate and integrated, may also be utilized with the mobile device 1000. Network access requirements vary depending upon the type of communication system. For example, in the Mobitex and DataTAC networks, mobile devices are registered on the network using a unique personal identification number or PIN associated with each device. In GPRS networks, however, network access is associated with a subscriber or user of a device. A GPRS device therefore requires a subscriber identity module, commonly referred to as a SIM card, in order to operate on a GPRS network. When required network registration or activation procedures have been completed, the mobile device 1000 may send and receive communications signals over the communication network 1401. Signals received from the communications network 1401 by the antenna 1540 are routed to the receiver 1500, which provides for signal amplification, frequency down conversion, filtering, channel selection, etc., and may also provide analog to digital conversion. Analog-to-digital conversion of the received signal allows the DSP 1580 to perform more complex communications functions, such as demodulation and decoding. In a similar manner, signals to be transmitted to the network 1401 are processed (e.g. modulated and encoded) by the DSP 1580 and are then provided to the transmitter 1520 for digital to analog conversion, frequency up conversion, filtering, amplification and transmission to the communication network 1401 (or networks) via the antenna 1560. In addition to processing communications signals, the DSP 1580 provides for control of the receiver 1500 and the transmitter 1520. For example, gains applied to communications signals in the receiver 1500 and transmitter 1520 may be adaptively controlled through automatic gain control algorithms implemented in the DSP 1580. In a data communications mode, a received signal, such as a text message or web page download, is processed by the communications subsystem 1001 and is input to the processing device 1800. The received signal is then further processed by the processing device 1800 for an output to the display 1600, or alternatively to some other auxiliary I/O device 1060. A device user may also compose data items, such as e-mail messages, using the keyboard 1400 and/or some other auxiliary I/O device 1060, such as a touchpad, a rocker switch, a thumb-wheel, or some other type of input device. The composed data items may then be transmitted over the communications network 1401 via the communications subsystem 1001. In a voice communications mode, overall operation of the device is substantially similar to the data communications mode, except that received signals are output to a speaker 1100, and signals for transmission are generated by a microphone 1120. Alternative voice or audio I/O subsystems, such as a voice message recording subsystem, may also be implemented on the device 1000. In addition, the display 1600 may also be utilized in voice communications mode, for example to display the identity of a calling party, the duration of a voice call, or other voice call related information. The short-range communications subsystem enables communication between the mobile device 1000 and other proximate systems or devices, which need not necessarily be similar devices. For example, the short-range communications subsystem may include an infrared device and associated circuits and components, or a Bluetooth™ communications module to provide for communication with similarly-enabled systems and devices. Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims. Computer Program Listings Program Listing #1 - Exemplary Authentication Request PROPFIND/ups HTTP/1.1 Depth: 0 Brief: t Pragma: no-cache Content-Type: text/xml X_UP_LOGIN: svr=login.oscar.aol.com&prt=5190&ssl=0&pcol=aol&uid=******&pwd=******&pwp= X_UP_SYNC: false X_UP_REFRESH_CACHE: force X_UP_NEWCON: 1 User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0) Connection: Keep-Alive Host: localhost:9080 Content-Length: 664 <?xml version=“1.0”?> <D:propfind xmlns:D=“DAV:” xmlns:h=“http://schemas.microsoft.com/hotmail/” xmlns:hm=“urn:schemas:httpmail:” xmlns:up=“urn:schemas:corp:universalproxy”> <D: prop> <hm:contacts/> <hm:calendar/> <hm:journal/> <hm:notes/> <hm:inbox/> <hm:outbox/> <hm:sendmsg/> <hm:sentitems/> <hm:deleteditems/> <hm:drafts/> <hm:msgfolderroot/> <up:corporatecontacts/> <h:maxpoll/> <h:sig/> </D:prop> </D:propfind> HTTP/1.1 207 Multi-Status Set-Cookie: JSESSIONID=C70CD1AED7D2BE210B34D93F7ACD6935; Path=/ups Content-Type: text/xml Transfer-Encoding: chunked Date: Wed, 06 Aug 2003 18:20:28 GMT Server: Apache Coyote/1.0 <?xml version=“1.0” encoding=“UTF-8”?> <D:multistatus xmlns:D=“DAV:” xmlns:up=“urn:schemas:corp:universalproxy” xmlns:c=“urn:schemas:calendar.” xmlns:a=“urn:schemas:contacts:” xmlns:hm=“urn:schemas:httpmail:” xmlns:m=“urn:schemas:mailheader.”> <D:response> <D:href>http://localhost:9080/ups/</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <hm:inbox>http://localhost:9080/ups/INBOX/</hm:inbox> <hm:sendmsg>http://localhost9080/ups/AOL_MAIL_SUBMISSION_URL/</hm:sendmsg> <hm:sentitems>http://localhost:9080/ups/Sent Items/</hm: sentitems> <hm:msgfolderroot>http://localhost:9080/ups/</hm:msgfolderroot> </D:prop> </D:propstat> </D:response> </D:multistatus> Program Listing #2 - Exemplary Inbox Request Query Folder Capabilities: REQUEST: OPTIONS /ups/INBOX/ HTTP/1.1 User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0) Connection: Keep-Alive Host: localhost:9080 Cookie: JSESSIONID=C70CD1AED7D2BE210B34D93F7ACD6935 Content-Length: 0 RESPONSE: HTTP/1.1 200 OK allow: OPTIONS, PROPFIND, MOVE, DELETE, BDELETE, BMOVE, SEARCH dasl: <urn:schemas:corp:universalproxy:basicsearch> Content-Type: text/plain Content-Length: 0 Date: Wed, 06 Aug 2003 18:20:28 GMT Server: Apache Coyote/1.0 List messages in INBOX: REQUEST: PROPFIND /ups/INBOX/ HTTP/1.1 Range: rows=0-24 Depth: 1,noroot Brief: t Pragma: no-cache Content-Type: text/xml X_UP_REFRESH_CACHE: force User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0) Connection: Keep-Alive Host: localhost:9080 Cookie: JSESSIONID=C70CD1AED7D2BE210B34D93F7ACD6935 Content-Length: 586 <?xml version=“1.0”?> <D:propfind xmlns:D=“DAV:” xmlns:hm=“urn:schemas:httpmail:” xmlns:m=“urn:schemas:mailheader.” xmlns:up=“urn:schemas:corp:universalproxy”> <D:prop> <D:uid/> <D:isfolder/> <D:ishidden/> <hm:read/> <hm:hasattachment/> <hm:importance/> <m:from/> <m:subject/> <m:date/> <up:isdeleted/> <D:getcontentlength/> <D:contentclass/> </D:prop> </D:propfind> RESPONSE: HTTP/1.1 207 Multi-Status Content-Range: rows 0-8; total=9 Content-Type: text/xml Transfer-Encoding: chunked Date: Wed, 06 Aug 2003 18:20:28 GMT Server: Apache Coyote/1.0 <?xml version=“1.0” encoding=“UTF-8”?> <D:multistatus xmlns:D=“DAV:” xmlns:up=“urn:schemas:corp:universalproxy” xmlns:c=“urn:schemas:calendar.” xmlns:a=“urn:schemas:contacts:” xmlns:hm=“urn:schemas:httpmail:” xmlns:m=“urn:schemas:mailheader:”> <D:contentrange>0-8</D:contentrange> <D:response> <D:href>http://localhost:9080/ups/INBOX/6623963; 1</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>3ac59b38c08ad3356435efea144660e3</D:uid> <D:isfolder>0</D:isfolder> <D:ishidden>0</D:ishidden> <hm:read>0</hm:read> <hm:hasattachment>0</hm:hasattachment> <hm:importance>1</hm:importance> <m:from>Mail Delivery Subsystem <[email protected]></m:from> <m:subject>Returned mail: User unknown</m:subject> <m:date>2003-08-05T23:12:48Z</m:date> <up:isdeleted>0</up:isdeleted> <D:getcontentlength>3247</D:getcontentlength> <D:contentclass>urn:content-classes:message</D:contentclass> </D:prop> </D:propstat> </D:response> <D:response> <D:href>http://localhost:9080/ups/INBOX/6623954;1</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>51073b22a28c2820115bc80d42e8c6ec</D:uid> <D:isfolder>0</D:isfolder> <D:ishidden>0</D:ishidden> <hm:read>1</hm:read> <hm:hasattachment>0</hm:hasattachment> <hm:importance>1</hm:importance> <m:from>[email protected]</m:from> <m:subject>Re: Test #1-All -French template</m:subject> <m:date>2003-08-05T23:10:30Z</m:date> <up:isdeleted>0</up:isdeleted> <D:getcontentlength>1577</D:getcontentlength> <D:contentclass>urn:content-classes:message</D:contentclass> </D:prop> </D:propstat> </D:response> <D:response> <D:href>http://localhost:9080/ups/INBOX/6623926;1</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>b072c3748ceff1320f9fa746f797e64b</D:uid> <D:isfolder>0</D:isfolder> <D:ishidden>0</D:ishidden> <hm:read>1</hm:read> <hm:hasattachment>0</hm:hasattachment> <hm:importance>1</hm:importance> <m:from>[email protected]</m:from> <m:subject>Re: xxxFWD: Re: Test #1</m:subject> <m:date>2003-08-05T23:07:18Z</m:date> <up:isdeleted>0</up:isdeleted> <D:getcontentlength>1927</D:getcontentlength> <D:contentclass>urn:content-classes:message</D:contentclass> </D:prop> </D:propstat> </D:response> <D:response> <D:href>http://localhost:9080/ups/INBOX/6623922;1</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>11f1c8e69555d33971aea12c09be5021</D:uid> <D:isfolder>0</D:isfolder> <D:ishidden>0</D:ishidden> <hm:read>1</hm:read> <hm:hasattachment>0</hm:hasattachment> <hm:importance>1</hm:importance> <m:from>[email protected]</m:from> <m:subject>Re: xxxFWD: Re: Test #1</m:subject> <m:date>2003-08-05T23:06:45Z</m:date> <up:isdeleted>0</up:isdeleted> <D:getcontentlength>1930</D:getcontentlength> <D:contentclass>urn:content-classes:message</D:contentclass> </D:prop> </D:propstat> </D:response> <D:response> <D:href>http://localhost:9080/ups/INBOX/6623915;1</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>55bc30adfb4fb66f3d11b0416c82b701</D:uid> <D:isfolder>0</D:isfolder> <D:ishidden>0</D:ishidden> <hm:read>1</hm:read> <hm:hasattachment>1</hm:hasattachment> <hm:importance>1</hm:importance> <m:from>[email protected]</m:from> <m:subject>xxxFWD: Re: Test #1</m:subject> <m:date>2003-08-05T23:05:27Z</m:date> <up:isdeleted>0</up:isdeleted> <D:getcontentlength>3254</D:getcontentlength> <D:contentclass>urn:content-classes:message</D:contentclass> </D:prop> </D:propstat> </D:response> <D:response> <D:href>http://localhost:9080/ups/INBOX/6623910;1</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>07cdf24a06f8e849754f90fe6dc8bf4f</D:uid> <D:isfolder>0</D:isfolder> <D:ishidden>0</D:ishidden> <hm:read>1</hm:read> <hm:hasattachment>0</hm:hasattachment> <hm:importance>1</hm:importance> <m:from>[email protected]</m:from> <m:subject>Re: Test #1-All</m:subject> <m:date>2003-08-05T23:04:31Z</m:date> <up:isdeleted>0</up:isdeleted> <D:getcontentlength>1258</D:getcontentlength> <D:contentclass>urn:content-classes:message</D:contentclass> </D:prop> </D:propstat> </D:response> <D:response> <D:href>http://localhost:9080/ups/INBOX/6623909;1</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>0e79a3593253ffb9596bf9d86873f498</D:uid> <D:isfolder>0</D:isfolder> <D:ishidden>0</D:ishidden> <hm:read>1</hm:read> <hm:hasattachment>0</hm:hasattachment> <hm:importance>1</hm:importance> <m:from>[email protected]</m:from> <m:subject>Re: Test #1</m:subject> <m:date>2003-08-05T23:04:13Z</m:date> <up:isdeleted>0</up:isdeleted> <D:getcontentlength>1241</D:getcontentlength> <D:contentclass>urn:content-classes:message</D:contentclass> </D:prop> </D:propstat> </D:response> <D:response> <D:href>http://localhost:9080/ups/INBOX/6605332;1</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>6060b944e60256c814498af29e5f0e47</D:uid> <D:isfolder>0</D:isfolder> <D:ishidden>0</D:ishidden> <hm:read>0</hm:read> <hm:hasattachment>0</hm:hasattachment> <hm:importance>1</hm:importance> <m:from>[email protected]</m:from> <m:subject>Security Notice to AOL Members</m:subject> <m:date>2003-08-01T23:00:58Z</m:date> <up:isdeleted>0</up:isdeleted> <D:getcontentlength>5137</D:getcontentlength> <D:contentclass>urn:content-classes:message</D:contentclass> </D:prop> </D:propstat> </D:response> <D:response> <D:href>http://localhost:9080/ups/INBOX/6567082;1</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>f47b72c8c1aa91458f40f81fce3b5e05</D:uid> <D:isfolder>0</D:isfolder> <D:ishidden>0</D:ishidden> <hm:read>0</hm:read> <hm:hasattachment>0</hm:hasattachment> <hm:importance>1</hm:importance> <m:from>[email protected]</m:from> <m:subject>Coming Soon - AOL 9.0 Optimized</m:subject> <m:date>2003-07-25T21:15:22Z</m:date> <up:isdeleted>0</up:isdeleted> <D:getcontentlength>10012</D:getcontentlength> <D:contentclass>urn:content-classes:message</D:contentclass> </D:prop> </D:propstat> </D:response> </D:multistatus> Program Listing #3 - Exemplary Folder Search Request Capabilities of folder: REQUEST: OPTIONS /ups HTTP/1.1 User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0) Connection: Keep-Alive Host: localhost:9080 Cookie: JSESSIONID=C70CD1AED7D2BE210B34D93F7ACD6935 Content-Length: 0 RESPONSE: HTTP/1.1 200 OK allow: OPTIONS, PROPFIND, MOVE, DELETE, BDELETE, BMOVE, SEARCH dasl: <urn:schemas:corp:universalproxy:basicsearch> Content-Type: text/plain Content-Length: 0 Date: Wed, 06 Aug 2003 18:20:28 GMT Server: Apache Coyote/1.0 Search for folders: REQUEST: SEARCH /ups HTTP/1.1 Depth: 1,noroot Brief: t Pragma: no-cache Content-Type: text/xml User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0) Connection: Keep-Alive Host: localhost:9080 Cookie: JSESSIONID=C70CD1AED7D2BE210B34D93F7ACD6935 Content-Length: 922 <?xml version=“1.0”?> <D:searchrequest xmlns:D=“DAV:” xmlns:t=“urn:schemas:corp:universalproxy”> <t:basicsearch> <D:select> <D:prop><D:uid/></D:prop> <D:prop><D:contentclass/></D:prop> <D:prop><D:displayname/></D:prop> </D:select> <D:from> <D:scope> <D:href>url</D:href> <D:depth>1</D:depth> </D:scope> </D:from> <D:where> <D:eq> <D:prop><D:contentclass/></D:prop> <D:literal>urn:content-classes:mailfolder</D:literal> </D:eq> </D:where> </t:basicsearch> </D:searchrequest> RESPONSE: HTTP/1.1 207 Multi-Status Content-Type:text/xml Transfer-Encoding: chunked Date: Wed, 06 Aug 2003 18:20:28 GMT Server: Apache Coyote/1.0 <?xml version=“1.0” encoding=“UTF-8”?> <D:multistatus xmlns:D=“DAV:” xmlns:up=“urn:schemas:corp:universalproxy” xmlns:c=“urn:schemas:calendar:” xmlns:a=“urn:schemas:contacts:” xmlns:hm=“urn:schemas:httpmail:” xmlns:m=“urn:schemas:mailheader:”> <D:response> <D:href>http://localhost:9080/ups/INBOX/</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>c90d66b2362a1a0bc3df1852021a6f63</D:uid> <D:contentclass>urn:content-classes:mailfolder</D:contentclass> <D:displayname>INBOX/</D:displayname> </D:prop> </D:propstat> </D:response> <D:response> <D:href>http://localhost:9080/ups/VOICE-MAIL/</D:href> <D:propstat> <D:status>HTTP/1.1 200 OK</D:status> <D:prop> <D:uid>cabbce34709ab79d2ad2d5334d998272</D:uid> <D:contentclass>urn:content-classes:mailfolder</D:contentclass> <D:displayname>VOICE-MAIL/</D:displayname> </D:prop> </D:propstat> </D:response> </D:multistatus> Program Listing #4 - Exemplary Configuration File <resource contentclass=“urn:content-classes:mailfolder” javaclass=“com.teamon.proxy.data.impl.MailFolderImpl” responsecacheduration=“0” cachestrength=“0”> <request method=“PROPFIND”> <header name=“Brief” value=“t” /> <header name=“Content-Type” value=“text/xml”/> <header name=“Depth” value=“1,noroot”/> <header name=“Range” value=“rows=$rangeStart$-$rangeEnd$”/> <header name=“Pragma” value=“no-cache”/> <header name=“X_UP_REFRESH_CACHE” value=“force” /> <body><![CDATA[ <?xml version=“1.0”?> <D:propfind xmlns:D=“DAV:” xmlns:hm=“urn:schemas:httpmail:” xmlns:m=“urn:schemas:mailheader:” xmlns:up=“urn:schemas:teamon:universalproxy”> <D:prop> <D:uid/> <D:isfolder/> <D:ishidden/> <hm:read/> <hm:hasattachment/> <hm:importance/> <m:from/> <m:subject/> <m:date/> <up:isdeleted/> <D:getcontentlength/> <D:contentclass/> </D:prop> </D:propfind> ]]> </body> </request> </resource> | <SOH> BACKGROUND OF THE INVENTION <EOH>Software clients operating on or in conjunction with a computer system are often used to access data stored at a server with which the computer system can establish communications, such as through a local area on the server is accessible only through a particular protocol, which in turn tends to limit a user to a particular client. Similarly, a particular type of client is typically configurable to operate with only certain types of servers or protocols. In an e-mail system, for example, in which users have associated mailboxes on a mail server, a particular protocol and often a particular messaging client is required for e-mail access. There is no single standard method for accessing e-mail stored on a server. Instead, there are several incompatible protocols defined by various vendors and standards bodies. In addition, the explosion of the Internet has resulted in several key problems. First, in order to obtain control over their user base, several Internet-based e-mail providers have extended standard protocols with their own proprietary extensions. Other vendors have gone away from RFC-based protocols and have defined new protocols from the ground up. Moreover, many vendors have chosen to implement standard protocols such as Internet Message Access Protocol (IMAP) and Post Office Protocol (POP), but have interpreted the rules of these protocols differently. Because of this proliferation of access mechanisms, there is no single way to access all of these mail stores. Applications that need to access these mail stores quickly become overly complicated when attempting to account for all of the different protocols and implementations of the protocols. Various prior art approaches have been developed for providing communications between systems and devices using different operating protocols. One such approach is set forth in U.S. Pat. No. 6,615,212 to Dutta et al., in which a transcoding proxy server receives a request for content from a client machine. The transcoding proxy server retrieves the content from an originating server. The retrieved content is provided in a first format type. In response to a determination that an increase in efficiency would be obtained by allowing the client to process the content in the first format type prior to transcoding the content into a second format type, the transcoding proxy server sends the content to the client in the first format type. Furthermore, in response to a determination that the client does not have content processing software for processing the content in the first format, the transcoding proxy server sends content processing software for the first format type along with the content in the first format type to the client. The transcoding proxy server then transcodes the content from the first format type into the second format type and sends the content in the second format to the client. Despite such prior art approaches, further protocol translation and/or conversion functionality may be desirable in certain applications. | <SOH> SUMMARY OF THE INVENTION <EOH>In view of the foregoing background, it is therefore an object of the present invention to provide a communications system providing enhanced operating protocol conversion features and related methods. This and other objects, features, and advantages in accordance with the present invention are provided by a communications system which may include a plurality of data storage devices for storing data using at least one of a plurality of different operating protocols. The system may further include a plurality of mobile wireless communications devices for accessing the data storage devices and each using at least one of the plurality of different operating protocols. Moreover, a protocol interface device may also be included. The protocol interface device may include a front-end proxy module for communicating with the plurality of mobile wireless communications devices using respective operating protocols, and a protocol engine module communicating with the front-end proxy module using a common interface protocol. The protocol interface device may also include a respective interface connector module for translating communications between the protocol engine module and the plurality of data storage devices for each of the different operating protocols. More particularly, the protocol engine module may be a universal proxy servlet module. In addition, the protocol interface device may also include a plurality of provider modules coupled between the universal proxy servlet module and the plurality of interface connector modules. The universal proxy servlet module may generate calls for the plurality of interface connector modules based upon respective data access requests from the front-end proxy module, and the plurality of provider modules transfer the calls to respective interface connector modules. By way of example, the interface connector modules may include a Microsoft Exchange connector module, a Domino connector module, an America Online (AOL) connector module, a Hotmail connector module, a Microsoft Network (MSN) connector module, a Compuserve connector module, a Post Office Protocol (POP) connector module, and an Internet Message Access Protocol (IMAP) connector module. Of course, other interface connector modules may also be used. The plurality of data storage devices, the plurality of mobile wireless communications devices, and the protocol interface device may process electronic mail (e-mail) messages, for example. Also, the common interface protocol may be based upon a Web-based distributed authoring and versioning (WebDAV) protocol. Furthermore, the protocol interface device may generate an error responsive to at least one non-supported operating protocol. The communications system may further include a wide area network (WAN), such as the Internet, connecting at least one of the mobile wireless communications devices with the protocol interface device. Additionally, such a WAN may also be used to connect at least one of the data storage devices with the protocol interface device. A method aspect of the invention is for interfacing a plurality of mobile wireless communications devices with a plurality of data storage devices. The mobile wireless communications devices and the data storage devices may each use at least one of a plurality of different operating protocols. The method may include providing a front-end proxy module for communicating with the plurality of mobile wireless communications devices using respective operating protocols, and providing a protocol engine module communicating with the front-end proxy module using a common interface protocol. The method may further include providing a respective interface connector module for translating communications between the protocol engine module and the plurality of data storage devices for each of the different operating protocols. A protocol interface device in accordance with the invention may include a front-end proxy module and a protocol engine module, such as those described briefly above, for example. Moreover, a computer-readable medium in accordance with the present invention may similarly include a front-end proxy module and a protocol engine module. | 20040212 | 20071030 | 20050217 | 68871.0 | 0 | LEROUX, ETIENNE PIERRE | COMMUNICATIONS SYSTEM WITH DATA STORAGE DEVICE INTERFACE PROTOCOL CONNECTORS AND RELATED METHODS | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,778,100 | ACCEPTED | Systems for regulating temperature in fluid ejection devices | Temperature regulating system for use in fluid ejection devices, such as inkjet printing devices, are provided. Such temperature regulating systems can include an ink reservoir, a printhead and optionally an intermediate ink container. Exchange of ink between the ink reservoir, or optionally the intermediate ink container, and the printhead regulates the temperature of the printhead and makes the temperature substantially uniform from drop ejector to drop ejector. Optionally, the ink is transported in a fluid communication path that is in contact with a thermally conductive substrate to further dissipate heat. Printing devices comprising such inkjet cartridges are also provided. | 1. A temperature regulating system for a fluid ejection device, comprising: a fluid reservoir; a fluid ejection device; at least one fluid communication path for carrying fluid between the fluid reservoir and the fluid ejection device; wherein the temperature regulating system causes fluid not ejected by the fluid ejection device to be recirculated to regulate the temperature of the fluid ejection device to be within a predetermined temperature range. 2. The temperature regulating system of claim 1, further comprising a thermally conductive substrate as a component of the fluid ejection device. 3. The temperature regulating system of claim 2, wherein the thermally conductive substrate is thermally coupled to both the fluid ejection device and at least one of the at least one fluid communication paths. 4. The temperature regulating system of claim 2, wherein at least a portion of the at least one fluid communication path is in contact with the thermally conductive substrate. 5. The temperature regulating system of claim 4, wherein at least a portion of the at least one fluid communication path is internal to the thermally conductive substrate. 6. The temperature regulating system of claim 1, further comprising a temperature sensor for detecting a temperature in the fluid ejection device. 7. The temperature regulating system of claim 6, wherein the temperature regulating system causes fluid to be carried from the fluid ejection device to the fluid reservoir when a predetermined temperature is detected by the temperature sensor. 8. The temperature regulating system of claim 1, wherein the fluid ejection device is a thermal ink jet printhead having one die module. 9. The temperature regulating system of claim 1, wherein the fluid ejection device is a thermal ink jet printhead having more than one die module. 10. An inkjet printing device, comprising the temperature regulating system of claim 1. 11. A temperature regulating system for a fluid ejection device, comprising: a fluid reservoir; an intermediate fluid container; a fluid ejection device; at least one first fluid communication path for carrying fluid between the fluid reservoir and the intermediate fluid container; at least one second fluid communication path for carrying fluid between the intermediate fluid container and the fluid ejection device; and wherein the temperature regulating system causes fluid not ejected by the fluid ejection device to be carried from the fluid ejection device to the intermediate fluid container via the at least one second fluid communication path, and from the intermediate fluid container to the fluid reservoir via the at least one first fluid communication path, to regulate the temperature of the fluid ejection device. 12. The temperature regulating system of claim 11, further comprising a thermally conductive substrate as a component of the fluid ejection device. 13. The temperature regulating system of claim 12, wherein the thermally conductive substrate is thermally coupled to both the fluid ejection device and at least one of the at least first communication path and the at least one second communication path. 14. The temperature regulating system of claim 12, wherein at least a portion of the at least one second fluid communication path is in contact with the thermally conductive substrate. 15. The temperature regulating system of claim 14, wherein at least a portion of the at least one second fluid communication path is internal to the thermally conductive substrate. 16. The temperature regulating system of claim 11, further comprising a temperature sensor for detecting a temperature of fluid in the intermediate fluid container. 17. The temperature regulating system of claim 16, wherein the temperature regulating system causes fluid to be carried from the intermediate fluid container to the fluid reservoir when a predetermined temperature is detected by the temperature sensor. 18. The temperature regulating system of claim 11 wherein the fluid ejection device is a thermal ink jet printhead having one die module. 19. The temperature regulating system of claim 11 wherein the fluid ejection device is a thermal ink jet printhead more than one die module. 20. An inkjet printing device, comprising the thermal regulating system of claim 11. | BACKGROUND OF THE INVENTION 1. Field of Invention This invention is directed to systems and methods for regulating temperature in fluid ejection devices. 2. Description of Related Art Inkjet printing devices have gained prominence in printing as result of their capabilities in performing quality, economical color and monochromatic printing. Inkjet printing devices include, but are not limited to, piezoelectric inkjet printing devices and thermal inkjet printing devices. Piezoelectric inkjet devices eject ink from a nozzle by mechanically generating pressure to deform an ink chamber. Thermal inkjet devices eject ink by energizing a heater element to vaporize ink. In such inkjet printing devices, a printhead, which acts to eject ink onto a recording medium, is comprised of at least one fluid ejecting die module, a substrate to which the die module is bonded, an ink manifold which brings ink to the die module, and electrical interconnection means for enabling the transfer of electrical signals to and from the printhead. The die module typically contains many individual drop ejecting elements, such as piezoelectric actuators or thermal ink jet heaters. In many types of inkjet printheads there is only one die module in the printhead. In other types of inkjet printheads, where it is desired to enable faster printing throughput than can be achieved using a single die module, several die modules are contained within the printhead. Because the fluid ejection process is dependent on the local temperature near the drop ejecting elements, it is important that the temperature be somewhat uniform in the various regions containing drop ejecting elements, whether within a single die module, or among several die modules. In addition, because fluid ejection can become unstable if the temperature gets too high or too low, it is important to keep the temperature within a certain range. The die module in a thermal inkjet printhead generates significant amounts of residual heat as ink is ejected by heating the ink to the point of vaporization. This residual heat will change the performance, and ultimately the ejection quality, if the excess heat remains within the printhead. Changes in printhead performance are usually manifested by a change in the drop size, firing sequence, or other related ejection metrics. Such ejection metrics desirably stay within a controllable range for acceptable ejection quality. During lengthy operation or heavy coverage ejection, the temperature of the printhead can exceed an allowable temperature limit. Once the temperature limit is exceeded, a slow down or cool down period is normally used to maintain the ejection quality. In addition to self-heating of the printhead, various ambient conditions may make it advantageous to regulate the temperature of an inkjet printhead or other fluid ejection device. A variety of devices and methods are conventionally used to dissipate heat in an inkjet printhead. Many inkjet printing devices improve throughput by improving thermal performance. One technique to improve printhead performance is to divert excess heat into the ink being ejected. As the hot ink is ejected from the printhead during printing, some amount of printhead cooling occurs as a result. During lengthy operation or heavy coverage ejection, this technique is also susceptible to temperatures in the printhead exceeding an allowable temperature. Another technique is to attach the die module to a substrate having heat sinking properties. Such substrates store heat and/or conduct heat away from the printhead. Typically, such substrates are made from copper, aluminum or other materials having high thermal conductivity to remove heat from the printhead. U.S. patent application Ser. No. 10/600,507, which is incorporated herein by reference in its entirety, discloses various exemplary embodiments of such substrates molded from a polymer mixed with at least one thermally-conductive filler material. Thermally conductive substrates, however, add additional weight, size, cost and/or energy usage to the printhead. Each of these becomes disadvantageous when in thermally conductive substrates attached to die modules that are translated past a receiving medium. Moreover, thermally conductive substrates typically dissipate heat via convection, and are inherently ineffective due to their small size. FIG. 1 is a schematic of a known inkjet printing system 100 showing one method by which ink is conventionally provided to a printhead 130. The system 100 includes a remote ink reservoir 110 and a printhead 130. The printhead is comprised of at least one die module 132, which is bonded to substrate 133, and an ink manifold 131 which brings ink via first fluid communication path 134 to the die module 132. Other components of the printhead 130, such as electrical interconnection means, are not shown. Typically, the remote ink reservoir 110 contains a much larger volume of ink than the ink manifold 131. The remote ink reservoir 110 can be 10 to 1000 times as large as the ink manifold 131. In the case of a scanning type of printhead, this type of ink supply configuration allows the mass of the moving printhead to remain small so that accelerations and decelerations of the scanning printhead do not exert unacceptably large forces on the printer. For either a scanning type of printhead or a stationary type of printhead, there is also typically not enough space near the printhead to store the entire supply of ink. The ink reservoir 110 and the ink manifold 131 are connected by a second fluid communication path 150. The second fluid communication path 150 allows ink stored in the ink reservoir 110 to be provided to the ink manifold 131. The ink is then supplied to the die module 132 as necessary to effect ejection of the ink from the printhead 130 onto a recording medium. Inkjet printing systems, such as shown in FIG. 1, are limited in their ability to dissipate heat. Such systems are limited because heat can only be dissipated via contact between the printhead and the thermally conductive substrate, and through ejection of ink during printing operations. SUMMARY OF THE INVENTION Notwithstanding the merits of the above methods, there is still a need for additional suitable ways to regulate temperature in fluid ejection systems, such as inkjet printheads. The present invention meets this need by providing systems, methods and structures in which fluid that is present in a fluid ejection system (e.g., ink exchanged between an ink reservoir and a printhead) is used to bring the temperature of a fluid ejector (e.g., a printhead) closer to that of the ink reservoir, for example by carrying heat away from the fluid ejector by recirculation. By carrying fluid in the fluid ejector to other parts of the fluid ejection system and/or to locations remote from the fluid ejector, heat in the fluid ejector is dissipated. The present invention is directed to systems, methods and structures for regulating temperature in fluid ejection systems. The present invention separately provides systems, methods and structures for regulating temperature of a fluid ejection system using a recirculating fluid supply. The present invention separately provides a fluid ejection system having a thermally conductive mass associated with a heat generating fluid ejector. In various exemplary embodiments, the recirculating fluid supply can be contacted with the thermally conductive mass to dissipate heat. The present invention is also directed to inkjet printheads, ink supply subsystems and inkjet printing devices including such systems. Various exemplary embodiments of the temperature regulating systems according to this invention include an ink reservoir and a printhead which are connected by two fluid communication paths: a first fluid communication path for providing ink from the ink reservoir to the printhead and a second fluid communication path for returning ink from the printhead to the ink reservoir. In various exemplary embodiments, the fluid communication path for supplying ink to the printhead and/or the fluid communication path for returning ink from the printhead to the ink reservoir are in contact with a thermally conductive substrate. Further exemplary embodiments of the temperature regulating systems according to this invention include an ink reservoir, an intermediate ink container and a printhead. In various exemplary embodiments, the ink reservoir and the intermediate ink container are connected by two fluid communication paths: a first fluid communication path for providing ink from the ink reservoir to the intermediate ink container and a second fluid communication path for returning ink from the intermediate ink container to the ink reservoir. In various exemplary embodiments, the intermediate ink container and the printhead are connected by two fluid communication paths: a first fluid communication path for providing ink from the intermediate ink container to the print head and a second fluid communication path for returning ink from the printhead to the intermediate ink container. In various exemplary embodiments, the fluid communication path for returning ink from the intermediate ink container to the ink reservoir and/or the fluid communication path for delivering ink from the ink reservoir to the intermediate ink container are in contact with a thermally conductive substrate. In various exemplary embodiments, the inkjet printheads and ink supply subsystems according to this invention are manufactured to include the temperature regulating systems according to this invention. In various exemplary embodiments, the printing devices according to this invention include inkjet printheads and ink supply subsystems manufactured employing the temperature regulating systems according to this invention. For a better understanding of the invention as well as other aspects and further features thereof, reference is made to the following drawings and descriptions. BRIEF DESCRIPTION OF THE DRAWINGS Various exemplary embodiments of the invention will be described in detail with reference to the following figures, wherein: FIG. 1 shows a schematic of a known inkjet printing system; FIG. 2 shows a schematic of an exemplary embodiment of a temperature regulating system for an inkjet printing device according to this invention; FIG. 3 shows a schematic of an exemplary embodiment of a temperature regulating system for an inkjet printing device according to this invention; FIG. 4 shows a schematic of an exemplary embodiment of a temperature regulating system for an inkjet printing device according to this invention; FIG. 5 shows a schematic of an exemplary embodiment of a temperature regulating system for an inkjet printing device according to this invention; FIG. 6A shows a front cross-section view of an exemplary embodiment of a thermally conductive substrate according to this invention; FIG. 6B shows a side cross-section view of an exemplary embodiment of a thermally conductive substrate according to this invention; FIG. 7A shows a front cross-section view of an exemplary embodiment of a thermally conductive substrate according to this invention; FIG. 7B shows a side cross-section view of an exemplary embodiment of a thermally conductive substrate according to this invention; FIG. 8A shows a front cross-section view of an exemplary embodiment of a thermally conductive substrate according to this invention; FIG. 8B shows a side cross-section view of an exemplary embodiment of a thermally conductive substrate according to this invention; DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS FIG. 2 is a schematic of an exemplary embodiment of a temperature regulating system 200 for an inkjet printing device according to this invention showing how ink is provided to the printhead 230. The temperature regulating system 200 includes an ink reservoir 210 with optional first temperature sensor 215, a printhead 230, a first fluid communication path 250, and second fluid communication path 252. The printhead 230 is comprised of at least one die module 232 which is bonded to thermally conductive substrate 233, and an ink manifold 231 which supplies ink to the die module 232 via a third fluid communication path 234. The second fluid communication path 252 is in contact with the thermally conductive substrate 233. Optionally there is a second temperature sensor 235 in the printhead 230. In various exemplary embodiments, the second temperature sensor 235 is located on the die module 232 or the thermally conductive substrate 233. In further exemplary embodiments, the second temperature sensor 235 is located in or adjacent to the ink manifold 231. In operation, ink for use in printing originates in the ink reservoir 210. The ink is transported from the ink reservoir 210 to the printhead 230 via the first fluid communication path 250. Some portion of the ink provided to the printhead 230 is ejected onto a recording medium. Excess ink can be returned from the printhead 230 to the ink reservoir 210 via the second fluid communication path 252. As discussed above, operation of the printhead 230 generates heat that can adversely affect printing. Either as a matter of course, or when a temperature outside an acceptable range is detected by the first temperature sensor 215 and/or the second temperature sensor 235, ink can be transported from the printhead 230 to the ink reservoir 210 via the second fluid communication path 252. The ink, when transported from printhead 230 to the ink reservoir 210, carries heat energy generated by the printhead 230 away from the printhead 230. The ink reservoir 210 is generally substantially larger than the ink manifold 231 and, especially in the case of thermal printheads, generally contains ink existing at a lower temperature than ink arriving from the printhead 230. Accordingly, when the relatively small amount of hot ink in the printhead 230 joins the relatively larger volume of ink in the ink reservoir 210 the heat energy is dissipated into a larger volume of ink. After the hot ink has been transported from the printhead 230 to the ink reservoir 210, and when additional ink for printing is needed, ink is again transported from the ink reservoir 210 to the printhead 230 via the first fluid communication path 250. Since additional amounts of heat can be carried away from a hot printhead, temperature can be better controlled than in the configuration shown in FIG. 1. This allows for extended printing without encountering heat effects in the printhead which would tend to degrade print quality. Of course, in other types of fluid ejection systems, a fluid ejector may not generate excessive heat. In such systems, it may still be useful to maintain the temperature of the fluid ejector at a substantially uniform level and/or within a given desired temperature range. While the exemplary embodiment described above is applicable to the case of dissipating excessive heat generated by a printhead, a more general case is that of maintaining the temperature of a fluid ejection system within a desirable temperature range which may be higher or may be lower than a fluid ejector, such as a printhead, would otherwise tend to reach, depending on ambient conditions and heat dissipation in the system. In various exemplary embodiments, the temperature regulating system for an inkjet printing device according to this invention includes a printhead and a separate ink reservoir. The printhead can include one or more die modules and an ink manifold. In various exemplary embodiments, the ink reservoir and printhead can be situated and shaped in any suitable manner that permits ink storage and allows printing to be accomplished. In various exemplary embodiments, the fluid communication paths for connecting the ink reservoir and the printhead are any type of fluid communication path suitable for linking the ink reservoir and printhead together and for storing and transporting ink. In various exemplary embodiments, the conduits can be flexible tubing. In various exemplary embodiments, the conduits can include valves for regulating the flow of ink. In various exemplary embodiments, one fluid communication path capable of controlled transport of ink to and from a location can be used in lieu of two separate fluid communication paths each capable of unidirectional transport. In various exemplary embodiments, the ink reservoir, printhead and fluid communication paths therebetween can be formed from any one or more materials suitable for storing and/or transporting ink, and for performing printing functions. In various exemplary embodiments, the ink reservoir and ink manifold can be formed from heat resistant polymers. In various exemplary embodiments, the fluid communication paths can be formed from heat resistant elastomers. In various exemplary embodiments, the thermally conductive substrate can be situated and shaped in any suitable manner that permits heat generated by the printhead to be dissipated. In various exemplary embodiments, the thermally conductive substrate is directly attached or bonded to the printhead through a thermally conductive bond. In various exemplary embodiments, the thermally conductive substrate is formed from a material having good heat conductivity. In some such embodiments, the thermally conductive substrate may be formed from aluminum, copper and/or a thermally conductive polymer. The temperature sensor can be any known or later developed device or apparatus for detecting and reporting temperature. In the exemplary embodiment shown in FIG. 2, ink travels to and from the ink reservoir via the first fluid communication path 250, which carries ink from the ink reservoir 210 to the ink manifold 231, and via the second fluid communication path 252, which carries ink from the ink manifold 231 through or across the thermally conductive substrate 233, and on to the ink reservoir 210. By directing the ink to flow through or across the thermally conductive substrate 233, the transfer of heat from the printhead 230 to the ink reservoir 210 is enabled to be more efficient. In some exemplary embodiments, the second fluid communication path 252 proceeds directly from ink manifold 231 to ink reservoir 210, without contacting the thermally conductive substrate 233. In the exemplary embodiment shown in FIG. 2, the first fluid communication path 250 proceeds from the ink reservoir 210 to the ink manifold 231. From there, the ink proceeds via the third fluid communication path 234 to the die module 232 for printing, and also via the second fluid communication path 252 across or through the thermally conductive substrate 233 for cooling by ink flow. The ink then proceeds via the second fluid communication path 252 from the thermally conductive substrate 233 to the ink reservoir 210. The second fluid communication path 252 can, of course, include two separate conduits, one leading from the ink manifold 231 to the thermally conductive substrate 233 and a second leading from the thermally conductive substrate 233 to the ink reservoir 210. FIG. 3 is a schematic of an exemplary embodiment of a temperature regulating system 300 for an inkjet printing device according to this invention showing how ink is provided to the printhead 330. The temperature regulating system 300 includes an ink reservoir 310 with optional first temperature sensor 315, a printhead 330, a first fluid communication path 350, and second fluid communication path 352. The printhead 330 is comprised of at least one die module 332 which is bonded to thermally conductive substrate 333, and an ink manifold 331 which supplies ink to the die module 332 via a third fluid communication path 334. The first fluid communication path 350 is in contact with the thermally conductive substrate 333. Optionally there is a second temperature sensor 335 in the printhead 330. In operation, the exemplary embodiment shown in FIG. 3 functions similarly to the exemplary embodiment shown in FIG. 2. However, the direction of ink flow is reversed. The first fluid communication path 350 carries ink from the ink reservoir 310 and across or through the thermally conductive substrate 333. From there, the first fluid communication path 350 carries the ink to the ink manifold 331. Some of the ink is carried via the third fluid communication path 334 to die module 332 for printing, while some of the ink is returned to ink reservoir 310 via the second fluid communication path 352. The first fluid communication path 350 can, of course, include two separate conduits, one leading from the ink reservoir 310 to the thermally conductive substrate 333 and a second leading from the thermally conductive substrate 333 to the ink manifold 331. FIG. 4 is a schematic of an exemplary embodiment of a temperature regulating system 400 for an inkjet printing device according to this invention showing how ink is provided to the printhead 430. The temperature regulating system 400 includes an ink reservoir 410, an intermediate ink container 420, and a printhead 430. The printhead 430 includes an ink manifold 431, a die module 432 and a thermally conductive substrate 433. The thermally conductive substrate 433 is directly attached or bonded to the die module 432 through a thermally conductive bond. The ink reservoir 410 and the intermediate ink container 420 are connected by a first fluid communication path 440. The first fluid communication path 440 allows ink stored in the ink reservoir 410 to be provided to the intermediate ink container 420. The intermediate ink container 420 typically contains a much lower volume of ink than the ink reservoir 410, so that it may reach a desired thermal steady state more rapidly. In addition, intermediate ink container 420 optionally includes a temperature sensor 425 and a heating or cooling subsystem 422. The heating or cooling subsystem 422 may include cooling fans, thermoelectric coolers, electric heaters or other such means to raise or lower the temperature of the ink in the intermediate ink container 420, together with optional temperature control circuitry. The intermediate ink container 420 and the printhead 430 are connected by a second fluid communication path 450 and a third fluid communication path 452. The second fluid communication path 450 allows ink stored in the intermediate ink container 420 to be provided to the printhead 430. The third fluid communication path 452 allows ink present in the printhead 430 to be returned to the intermediate ink container 420. The intermediate ink container 420 and the ink reservoir 410 are connected by a fourth fluid communication path 442. The fourth fluid communication path 442 allows ink in the intermediate ink container 420 to be returned to the ink reservoir 410. In operation, ink for use in printing originates in the ink reservoir 410. The ink is transported from the ink reservoir 410 to the intermediate ink container 420 via the first fluid communication path 440. Ink temperature may optionally be controlled in the intermediate ink container using the heating or cooling subsystem 422. When required for printing, the ink is transported from the intermediate ink container 420 to the printhead 430 via the second fluid communication path 450. Some portion of the ink provided from the ink manifold 431 to the die module 432 via a fifth fluid communication path 434, and is ejected onto a recording medium. Excess ink, and the associated heat energy generated by the printhead 430 can be returned from the printhead 430 to the intermediate ink container 420 via the third fluid communication path 452. Either as a matter of course, or when excess heat is detected, ink can be transported from the intermediate ink container 420 to the ink reservoir 410 via the fourth fluid communication path 442. The ink reservoir 410 is generally at a lower temperature than the ink in the intermediate ink container, and is remote from the printhead 430. Accordingly, when the hot ink in the intermediate ink container 420 is transported to the ink reservoir 410, the heat energy is dissipated. After the ink has cooled, at least to some extent, it is transferred from the ink reservoir 410 to the intermediate ink container 420 via the first fluid communication path 440. In the exemplary embodiment shown in FIG. 4, ink travels between the intermediate ink container 420 and the printhead 430 via the second fluid communication path 450, which carries ink from the intermediate ink container 420 to the ink manifold 431, and via the third fluid communication path 452, which carries ink from the ink manifold 431 through or across the thermally conductive substrate 433, and on to the intermediate ink container 420. By directing the ink to flow through or across the thermally conductive substrate 433, the transfer of heat from the printhead 430 to the ink reservoir 410 is enabled to be more efficient. In some exemplary embodiments, the third fluid communication path 452 proceeds directly from ink manifold 431 to the intermediate ink container 420, without contacting the thermally conductive substrate 433. The second fluid communication path 452 can, of course, include two separate conduits, one leading from the ink manifold 431 to the thermally conductive substrate 433 and a second leading from the thermally conductive substrate 433 to the intermediate ink container 210. In various exemplary embodiments, the intermediate ink container, like the ink reservoir and printhead, can be situated and shaped in any suitable manner that permits ink storage and allows printing to be accomplished. In various exemplary embodiments, the temperature regulating system for an inkjet printing device according to this invention includes a printhead, a separate ink reservoir and a separate intermediate ink container. In various exemplary embodiments, the fluid communication paths for connecting the ink reservoir to the intermediate ink container are any type of fluid communication paths suitable for linking those elements and for storing and transporting ink. In various exemplary embodiments, the conduits can be flexible tubing. In various exemplary embodiments the conduits can include valves for regulating the flow of ink. In various exemplary embodiments, the intermediate ink container and the conduits between the intermediate ink container and the ink reservoir can be formed from any one or more materials suitable for storing and/or transporting ink, and for performing printing functions. In various exemplary embodiments, the intermediate ink container can be formed from a heat resistant polymer. In various exemplary embodiments, the fluid communication paths can be formed from heat resistant elastomers. In various exemplary embodiments, the intermediate ink container may be formed from a thermally conductive material, such as metal or a conductive polymer, so as to serve as a thermally conductive substrate releasing heat from the ink to ambient air. FIG. 5 is a schematic of an exemplary embodiment of a temperature regulating system 500 for an inkjet printing device according to this invention showing how ink is provided to the printhead 530. The temperature regulating system 500 includes an ink reservoir 510, an intermediate ink container 520, and a printhead 530. The printhead 530 includes an ink manifold 531, a die module 532 and a thermally conductive substrate 533. The thermally conductive substrate 533 is directly attached or bonded to the die module 532 through a thermally conductive bond. The ink reservoir 510 and the intermediate ink container 520 are connected by a first fluid communication path 540. The first fluid communication path 540 allows ink stored in the ink reservoir 510 to be provided to the intermediate ink container 520. The intermediate ink container 520 optionally includes a temperature sensor 525 and a heating or cooling subsystem 522. The heating or cooling subsystem 522 may include cooling fans, thermoelectric coolers, electric heaters or other such means to raise or lower the temperature of the ink in the intermediate ink container 520, together with optional temperature control circuitry. The intermediate ink container 520 and the printhead 530 are connected by a second fluid communication path 550 and a third fluid communication path 552. The second fluid communication path 550 allows ink stored in the intermediate ink container 520 to be provided to the printhead 530. The third fluid communication path 552 allows ink present in the printhead 530 to be returned to the intermediate ink container 520. The intermediate ink container 520 and the ink reservoir 510 are connected by a fourth fluid communication path 542. The fourth fluid communication path 542 allows ink in the intermediate ink container 520 to be returned to the ink reservoir 510. In operation, the exemplary embodiment shown in FIG. 5 functions similarly to the exemplary embodiment shown in FIG. 4. However, the direction of ink flow between the intermediate ink container 520 and the ink manifold 531 is reversed. The second fluid communication path 450 carries ink from the intermediate ink container 520 and across or through the thermally conductive substrate 533. From there, the second fluid communication path 550 carries the ink to the ink manifold 531. Some of the ink is carried via a fifth fluid communication path 534 to die module 532 for printing, while some of the ink is returned to intermediate ink container 520 via the second fluid communication path 552. The second fluid communication path 550 can, of course, include two separate conduits, one leading from the intermediate ink container 520 to the thermally conductive substrate 533 and a second leading from the thermally conductive substrate 533 to the ink manifold 531. As described above, in various exemplary embodiments, one or more of the fluid communication paths contacts the thermally conductive substrate. FIGS. 6-8 show various exemplary ways in which such contact between the fluid communication path and the thermally conductive substrate can be made. As the surface area of the portion of the fluid communication path in contact with the thermally conductive substrate is increased (e.g., by forming at least part of the fluid communication path inside of the thermally conductive substrate or increasing the length of the portion of the fluid communication path in contact with the thermally conductive substrate), the heat dissipating effect of that contact is increased. The configurations of fluid communication path and thermally conductive substrate shown in FIGS. 6-8 are not intended to limit the scope of the present invention. Numerous variations on the configurations shown in FIGS. 6-8 will be apparent to those of ordinary skill in the art. FIGS. 6A and 6B show an exemplary embodiment of a thermally conductive substrate 670 according to this invention. The thermally conductive substrate 670 is in contact with a fluid communication path 642. In this embodiment, a portion of an outside surface of the fluid communication path 642 contacts a planar surface of the thermally conductive substrate 670. FIGS. 7A and 7B show an exemplary embodiment of a thermally conductive substrate 770 according to this invention. The thermally conductive substrate 770 is in contact with a fluid communication path 742. In this embodiment, a portion of the fluid communication path 742, is internal to the thermally conductive substrate 770. FIGS. 8A and 8B show an exemplary embodiment of a thermally conductive substrate 870 according to this invention. The thermally conductive substrate 870 is in contact with a fluid communication path 842. In this embodiment, a portion of the fluid communication path 842 is internal to the thermally conductive substrate 870. The portion of the fluid communication path 842 internal to the thermally conductive substrate 870 may be curved, coiled, sinusoidal or other-shaped, so as to increase the surface area of the fluid communication path 842 that is in contact with the thermally conductive substrate 870. While this invention has been described in conjunction with the exemplary embodiments outlined above, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or that are or may be presently unforeseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention. Therefore, the claims as filed and as they may be amended are intended to embrace all known or later developed alternatives, modifications, variations, improvements, and/or substantial equivalents. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention This invention is directed to systems and methods for regulating temperature in fluid ejection devices. 2. Description of Related Art Inkjet printing devices have gained prominence in printing as result of their capabilities in performing quality, economical color and monochromatic printing. Inkjet printing devices include, but are not limited to, piezoelectric inkjet printing devices and thermal inkjet printing devices. Piezoelectric inkjet devices eject ink from a nozzle by mechanically generating pressure to deform an ink chamber. Thermal inkjet devices eject ink by energizing a heater element to vaporize ink. In such inkjet printing devices, a printhead, which acts to eject ink onto a recording medium, is comprised of at least one fluid ejecting die module, a substrate to which the die module is bonded, an ink manifold which brings ink to the die module, and electrical interconnection means for enabling the transfer of electrical signals to and from the printhead. The die module typically contains many individual drop ejecting elements, such as piezoelectric actuators or thermal ink jet heaters. In many types of inkjet printheads there is only one die module in the printhead. In other types of inkjet printheads, where it is desired to enable faster printing throughput than can be achieved using a single die module, several die modules are contained within the printhead. Because the fluid ejection process is dependent on the local temperature near the drop ejecting elements, it is important that the temperature be somewhat uniform in the various regions containing drop ejecting elements, whether within a single die module, or among several die modules. In addition, because fluid ejection can become unstable if the temperature gets too high or too low, it is important to keep the temperature within a certain range. The die module in a thermal inkjet printhead generates significant amounts of residual heat as ink is ejected by heating the ink to the point of vaporization. This residual heat will change the performance, and ultimately the ejection quality, if the excess heat remains within the printhead. Changes in printhead performance are usually manifested by a change in the drop size, firing sequence, or other related ejection metrics. Such ejection metrics desirably stay within a controllable range for acceptable ejection quality. During lengthy operation or heavy coverage ejection, the temperature of the printhead can exceed an allowable temperature limit. Once the temperature limit is exceeded, a slow down or cool down period is normally used to maintain the ejection quality. In addition to self-heating of the printhead, various ambient conditions may make it advantageous to regulate the temperature of an inkjet printhead or other fluid ejection device. A variety of devices and methods are conventionally used to dissipate heat in an inkjet printhead. Many inkjet printing devices improve throughput by improving thermal performance. One technique to improve printhead performance is to divert excess heat into the ink being ejected. As the hot ink is ejected from the printhead during printing, some amount of printhead cooling occurs as a result. During lengthy operation or heavy coverage ejection, this technique is also susceptible to temperatures in the printhead exceeding an allowable temperature. Another technique is to attach the die module to a substrate having heat sinking properties. Such substrates store heat and/or conduct heat away from the printhead. Typically, such substrates are made from copper, aluminum or other materials having high thermal conductivity to remove heat from the printhead. U.S. patent application Ser. No. 10/600,507, which is incorporated herein by reference in its entirety, discloses various exemplary embodiments of such substrates molded from a polymer mixed with at least one thermally-conductive filler material. Thermally conductive substrates, however, add additional weight, size, cost and/or energy usage to the printhead. Each of these becomes disadvantageous when in thermally conductive substrates attached to die modules that are translated past a receiving medium. Moreover, thermally conductive substrates typically dissipate heat via convection, and are inherently ineffective due to their small size. FIG. 1 is a schematic of a known inkjet printing system 100 showing one method by which ink is conventionally provided to a printhead 130 . The system 100 includes a remote ink reservoir 110 and a printhead 130 . The printhead is comprised of at least one die module 132 , which is bonded to substrate 133 , and an ink manifold 131 which brings ink via first fluid communication path 134 to the die module 132 . Other components of the printhead 130 , such as electrical interconnection means, are not shown. Typically, the remote ink reservoir 110 contains a much larger volume of ink than the ink manifold 131 . The remote ink reservoir 110 can be 10 to 1000 times as large as the ink manifold 131 . In the case of a scanning type of printhead, this type of ink supply configuration allows the mass of the moving printhead to remain small so that accelerations and decelerations of the scanning printhead do not exert unacceptably large forces on the printer. For either a scanning type of printhead or a stationary type of printhead, there is also typically not enough space near the printhead to store the entire supply of ink. The ink reservoir 110 and the ink manifold 131 are connected by a second fluid communication path 150 . The second fluid communication path 150 allows ink stored in the ink reservoir 110 to be provided to the ink manifold 131 . The ink is then supplied to the die module 132 as necessary to effect ejection of the ink from the printhead 130 onto a recording medium. Inkjet printing systems, such as shown in FIG. 1 , are limited in their ability to dissipate heat. Such systems are limited because heat can only be dissipated via contact between the printhead and the thermally conductive substrate, and through ejection of ink during printing operations. | <SOH> SUMMARY OF THE INVENTION <EOH>Notwithstanding the merits of the above methods, there is still a need for additional suitable ways to regulate temperature in fluid ejection systems, such as inkjet printheads. The present invention meets this need by providing systems, methods and structures in which fluid that is present in a fluid ejection system (e.g., ink exchanged between an ink reservoir and a printhead) is used to bring the temperature of a fluid ejector (e.g., a printhead) closer to that of the ink reservoir, for example by carrying heat away from the fluid ejector by recirculation. By carrying fluid in the fluid ejector to other parts of the fluid ejection system and/or to locations remote from the fluid ejector, heat in the fluid ejector is dissipated. The present invention is directed to systems, methods and structures for regulating temperature in fluid ejection systems. The present invention separately provides systems, methods and structures for regulating temperature of a fluid ejection system using a recirculating fluid supply. The present invention separately provides a fluid ejection system having a thermally conductive mass associated with a heat generating fluid ejector. In various exemplary embodiments, the recirculating fluid supply can be contacted with the thermally conductive mass to dissipate heat. The present invention is also directed to inkjet printheads, ink supply subsystems and inkjet printing devices including such systems. Various exemplary embodiments of the temperature regulating systems according to this invention include an ink reservoir and a printhead which are connected by two fluid communication paths: a first fluid communication path for providing ink from the ink reservoir to the printhead and a second fluid communication path for returning ink from the printhead to the ink reservoir. In various exemplary embodiments, the fluid communication path for supplying ink to the printhead and/or the fluid communication path for returning ink from the printhead to the ink reservoir are in contact with a thermally conductive substrate. Further exemplary embodiments of the temperature regulating systems according to this invention include an ink reservoir, an intermediate ink container and a printhead. In various exemplary embodiments, the ink reservoir and the intermediate ink container are connected by two fluid communication paths: a first fluid communication path for providing ink from the ink reservoir to the intermediate ink container and a second fluid communication path for returning ink from the intermediate ink container to the ink reservoir. In various exemplary embodiments, the intermediate ink container and the printhead are connected by two fluid communication paths: a first fluid communication path for providing ink from the intermediate ink container to the print head and a second fluid communication path for returning ink from the printhead to the intermediate ink container. In various exemplary embodiments, the fluid communication path for returning ink from the intermediate ink container to the ink reservoir and/or the fluid communication path for delivering ink from the ink reservoir to the intermediate ink container are in contact with a thermally conductive substrate. In various exemplary embodiments, the inkjet printheads and ink supply subsystems according to this invention are manufactured to include the temperature regulating systems according to this invention. In various exemplary embodiments, the printing devices according to this invention include inkjet printheads and ink supply subsystems manufactured employing the temperature regulating systems according to this invention. For a better understanding of the invention as well as other aspects and further features thereof, reference is made to the following drawings and descriptions. | 20040217 | 20061024 | 20050818 | 59579.0 | 0 | FIDLER, SHELBY LEE | SYSTEMS FOR REGULATING TEMPERATURE IN FLUID EJECTION DEVICES | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,778,507 | ACCEPTED | Vented soffit panel and method for buildings and like | A vented soffit panel and related method for buildings and the like includes a generally flat imperforate base portion shaped to enclose at least a portion of the building soffit when mounted in a generally horizontal orientation under an eave. At least one vent channel protrudes upwardly from the base portion, and has a generally trapezoidal shape defined by a horizontal imperforate top wall and inclined perforate sidewalls with lower ends that connect with the base portion in a spaced apart relationship to define a slot through which air flows to vent the eave. The perforate sidewalls are disposed at an acute angle, such that they are hidden from view from a position underneath the eave. | 1. A vented soffit panel for building roofs and the like of the type having at least one eave with a soffit thereunder; comprising: a generally flat, imperforate base portion shaped to enclose at least a portion of the soffit when mounted in a generally horizontal orientation under the eave; and at least one vent channel portion extending along said base portion, and protruding upwardly therefrom; said vent channel portion having a generally trapezoidal lateral cross-sectional shape defined by a generally horizontal imperforate top wall and inclined perforate sidewalls with lower ends thereof connected with said base portion in a mutually spaced apart relationship to define a slot therebetween through which ambient air enters into said vent channel and flows through said perforate sidewalls to vent the eave; said perforate sidewalls being disposed at a predetermined acute angle relative to said top wall and said base portion, whereby when said soffit panel is installed in said generally horizontal orientation, said perforate sidewalls are hidden from view from a position underneath the eave. 2. A vented soffit panel as set forth in claim 1, wherein: said predetermined acute angle of said perforate sidewalls is in the range of 20-70 degrees. 3. A vented soffit as set forth in claim 2, wherein: said predetermined acute angle of said perforate sidewalls is less than 60 degrees. 4. A vented soffit panel as set forth in claim 3, wherein: said predetermined acute angle of each of said perforate sidewalls is substantially identical such that said trapezoidal shape is generally regular. 5. A vented soffit panel as set forth in claim 4, wherein: said predetermined acute angle of each of said perforate sidewalls is around 60 degrees. 6. A vented soffit panel as set forth in claim 5, wherein: said slot has a predetermined width in the range of 0.125-0.750 inches. 7. A vented soffit panel as set forth in claim 6, wherein: said predetermined width of said slot is in the range of 0.20-0.30 inches. 8. A vented soffit panel as set forth in claim 7, wherein: said predetermined width of said slot is around 0.26 inches. 9. A vented soffit panel as set forth in claim 8, wherein: said perforate sidewalls include a plurality of apertures extending laterally therethrough. 10. A vented soffit panel as set forth in claim 9, wherein: said apertures have a generally circular plan shape. 11. A vented soffit panel as set forth in claim 10, wherein: said apertures are sized to permit ambient air to flow freely therethrough, yet prevent bugs and debris from entering the soffit. 12. A vented soffit panel as set forth in claim 11, wherein: said apertures have a diameter in the range of 0.080-0.100 inches. 13. A vented soffit panel as set forth in claim 12, wherein: said apertures have a diameter of around 0.094 inches. 14. A vented soffit panel as set forth in claim 13, wherein: said perforate sidewalls each have around 21 of said apertures per inch. 15. A vented soffit panel as set forth in claim 5, wherein: said apertures are arranged in a plurality of mutually staggered rows. 16. A vented soffit panel as set forth in claim 15, wherein: said base portion includes opposed end edges defining a predetermined width therebetween which is substantially commensurate with the width of the soffit to fully enclose the same; and wherein: said vent channel extends along said predetermined width of said soffit panel. 17. A vented soffit panel as set forth in claim 16, wherein: said vent channel extends continuously along the entire width of said base portion in a generally parallel relationship with said opposed end edges. 18. A vented soffit panel as set forth in claim 17, including: a plurality of said vent channels extending across the width of said base portion in a mutually parallel relationship. 19. A vented soffit panel as set forth in claim 18, wherein: said base portion includes opposed side edges with flanges shaped for connection with like flanges of an adjacent one of said vented soffit panels to fully enclose the soffit. 20. A vented soffit panel as set forth in claim 19, wherein: said base portion and said vent channels are integrally formed to provide a one-piece construction. 21. A vented soffit panel as set forth in claim 20, wherein: said vented soffit panel is constructed from roll formed aluminum. 22. A vented soffit panel as set forth in claim 21, wherein: said apertures have central axes disposed generally perpendicular to the associated one of said perforate sidewalls. 23. A vented soffit as set forth in claim 22, wherein: said imperforate top wall is spaced apart from said base portion a distance in the range of 0.40-0.50 inches. 24. A vented soffit panel as set forth in claim 1, wherein: said predetermined acute angle of each of said perforate sidewalls is substantially identical such that said trapezoidal shape is generally regular. 25. A vented soffit panel as set forth in claim 1, wherein: said predetermined acute angle of each of said perforate sidewalls is around 60 degrees. 26. A vented soffit panel as set forth in claim 1, wherein: said slot has a predetermined width in the range of 0.125-0.750 inches. 27. A vented soffit panel as set forth in claim 1, wherein: said predetermined width of said slot is in the range of 0.20-0.30 inches. 28. A vented soffit panel as set forth in claim 1, wherein: said predetermined width of said slot is around 0.26 inches. 29. A vented soffit panel as set forth in claim 1, wherein: said perforate sidewalls include a plurality of apertures extending laterally therethrough. 30. A vented soffit panel as set forth in claim 29, wherein: said apertures have a generally circular plan shape. 31. A vented soffit panel as set forth in claim 29, wherein: said apertures are sized to permit ambient air to flow freely therethrough, yet prevent bugs and debris from entering the soffit. 32. A vented soffit panel as set forth in claim 29, wherein: said apertures have a diameter in the range of 0.080-0.100 inches. 33. A vented soffit panel as set forth in claim 29, wherein: said apertures have a diameter of around 0.094 inches. 34. A vented soffit panel as set forth in claim 29, wherein: said perforate sidewalls each have around 21 of said apertures per inch. 35. A vented soffit panel as set forth in claim 29, wherein: said apertures are arranged in a plurality of mutually staggered rows. 36. A vented soffit panel as set forth in claim 1, wherein: said base portion includes opposed end edges defining a predetermined width therebetween which is substantially commensurate with the width of the soffit to fully enclose the same; and wherein: said vent channel extends along said predetermined width of said soffit panel. 37. A vented soffit panel as set forth in claim 1, including: a plurality of said vent channels extending across the width of said base portion in a mutually parallel relationship. 38. A vented soffit panel as set forth in claim 1, wherein: said base portion includes opposed side edges with flanges shaped for connection with like flanges of an adjacent one of said vented soffit panels to fully enclose the soffit. 39. A vented soffit panel as set forth in claim 1, wherein: said base portion and said vent channels are integrally formed to provide a one-piece construction. 40. A vented soffit panel as set forth in claim 1, wherein: said vented soffit panel is constructed from roll formed aluminum. 41. A vented soffit panel as set forth in claim 30, wherein: said apertures have central axes disposed generally perpendicular to the associated one of said perforate sidewalls. 42. In a method for venting building roofs and the like of the type having at least one eave with a soffit defined thereunder, the improvement comprising: forming a plurality of vented soffit panels, each having a generally flat, imperforate base portion shaped to enclose at least a portion of the soffit when mounted in a generally horizontal orientation under the eave, and at least one vent channel portion extending along said base portion, and protruding upwardly therefrom, wherein the vent channel portion has a generally trapezoidal lateral cross-sectional shape defined by a generally horizontal imperforate top wall and inclined perforate sidewalls with lower ends thereof connected with said base portion in a mutually spaced apart relationship to define a slot therebetween through which ambient air enters into said vent channel and flows through said perforate sidewalls to vent the eave and the perforate sidewalls are disposed at a predetermined acute angle relative to said top wall and said base portion; and installing the soffit panels in a side-by-side, generally horizontal position under the eave, such that the eave is enclosed, and the perforate sidewalls are hidden from view from a position underneath the eave. 43. A method as set forth in claim 42, wherein: said forming step includes forming the predetermined acute angle of the perforate sidewalls in a range of 20-70 degrees. 44. A method as set forth in claim 43, wherein: said forming step includes forming the predetermined acute angle of the perforate sidewalls at less than 65 degrees. 45. A method as set forth in claim 44, wherein: said forming step includes forming the slot with a predetermined width in the range of 0.125-0.750 inches. 46. A method as set forth in claim 45, wherein: said forming step includes forming the perforate sidewalls with a plurality of apertures extending laterally therethrough. 47. A method as set forth in claim 46, wherein: said forming step roll forming each of the soffit panels from sheet aluminum. | BACKGROUND OF THE INVENTION The present invention relates to building construction, and in particular to a vented soffit panel and related method for buildings and the like. Soffit panels are generally well-known in the art, and serve to cover or enclose the underside of the eaves of homes and other buildings of the type having roof eaves which extend beyond and hang over the outside walls of the building. The purpose of the soffit panels is to hide the eaves from view, and prevent the use of the underside of the eaves as a nesting place for insects, birds and the like. In modern day building construction, the soffit is normally vented to allow outside air to flow into the attic of the building to equalize the attic temperature and pressure with that of the outside environment. This equalization helps to prevent degradation of the roof, reduce moisture accumulation, and improve the heating and cooling efficiency for the building interior. While some soffit panels are perforated or louvered to facilitate venting, they possess certain drawbacks. One such disadvantage is that insects, such as bees, bugs and the like, can get through the vents, and use the soffit as a nesting place. Debris can also become lodged in the vents to impede the free flow of air into the eave. Furthermore, such prior soffit panels normally have exposed or visible vents, thereby detracting from the overall appearance of the structure. Consequently, a soffit panel which overcomes these problems would be advantageous. SUMMARY OF THE INVENTION One aspect of the present invention is a vented soffit panel for buildings and the like, which includes a generally flat imperforate base portion shaped to enclose at least a portion of the building soffit when mounted in a generally horizontal orientation under an eave. At least one vent channel protrudes upwardly from the base portion, and has a generally trapezoidal shape defined by horizontal imperforate top wall and inclined perforate sidewalls with lower ends that connect with the base portion in a spaced apart relationship to define a slot through which air flows to vent the eave. The perforate sidewalls are disposed at an acute angle, such that they are hidden from view from a position underneath the eave. Another aspect of the present invention is a method for venting building roofs and the like of the type having at least one eave with a soffit thereunder. The method comprises forming a plurality of vented soffit panels, each having a generally flat imperforate base portion shaped to enclose at least a portion of the soffit when mounted in a generally horizontal orientation under the eave, and at least one vent channel portion extending along the base portion, and protruding upwardly therefrom, wherein the vent channel portion has a generally trapezoidal lateral cross-sectional shape defined by a generally horizontal imperforate top wall and inclined perforate sidewalls with lower ends connected with the base portion in a mutually spaced apart relationship to define a slot therebetween through which ambient air enters into the vent channel and flows through the perforate sidewalls to vent the eave, wherein the perforate sidewalls are disposed at a predetermined acute angle relative to the top wall and the base portion. The method further includes installing the soffit panels in a side-by-side, generally horizontal position under the eave, such that the eave is enclosed, and the perforate sidewalls of the vented soffit panels are hidden from view from a position underneath the eave. Yet another aspect of the present invention is a vented soffit panel which has a hidden venting structure for improved aesthetics, yet prevents insects, bugs and other debris from entering the soffit or eave. The vented soffit panel has an uncomplicated design, is easy to install, and economical to manufacture. Preferably, the vented soffit panel is constructed from roll formed aluminum or the like to provide a very lightweight, yet durable, product. These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims, and appended drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a vented soffit panel embodying the present invention. FIG. 2 is an enlarged, fragmentary view of the soffit panel, showing airflow therethrough. FIG. 3 is an enlarged, fragmentary, vertical cross-sectional view of the soffit panel, showing a vent channel portion thereof. FIG. 4 is an end view of the vented soffit panel. FIG. 5 is a bottom plan view of the vented soffit panel. FIG. 6 is a cross-sectional view of the vented soffit panel, taken the along the line VI-VI, FIG. 4. FIG. 7 is a front elevational view of a plurality of soffit panels interconnected along opposite edges. FIG. 8 is a partially schematic view of a roof eve with the soffit panel installed therein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For purposes of description herein, the terms “upper”, “lower”, “right”, “left”, “rear”, “front”, “vertical”, “horizontal”, and derivatives thereof shall relate to the invention as oriented in FIG. 1, and installed in a generally horizontal orientation under an associated eave. However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. The reference numeral 1 (FIG. 1) generally designates a vented soffit panel embodying the present invention. In the illustrated example, vented soffit panel 1 includes a generally flat imperforate base portion 2 shaped to enclose at least a portion of the building soffit 3 (FIG. 8) when mounted in a generally horizontal orientation under an eave 4. At least one vent channel 5 (FIGS. 1-3) protrudes upwardly from the base portion 2, and has a generally trapezoidal shape defined by a horizontal imperforate top wall 6, and inclined perforate sidewalls 7 with lower ends 8 that connect with base portion 2 in a spaced apart relationship to define a slot 9 through which air flows to vent eave 4. The perforate sidewalls 7 are disposed at an acute angle relative to top wall 6 and base portion 2, such that they are hidden from view from a position underneath eave 4. In the example illustrated in FIG. 8, building 15 has a substantially conventional construction, comprising an exterior wall 16 and an inclined roof 17 which protrudes over exterior wall 16 to define eave 4. A fascia board 18 extends along the lower edge of roof 17, and depends downwardly therefrom, and is typically fastened to the ends of the rafters 19. A ledger board 20 is attached to the exterior wall 16 of building 15 at a location generally horizontally aligned with the bottom of fascia board 18. Vented soffit panels 1 are positioned in a side-by-side relationship beneath the overhang or eave 4, and extend from fascia board 18 to ledger board 20 to enclose the underside of eave 4 and define soffit 3, which communicates with the attic (not shown) of building 15. In the illustrated example, vented soffit panel 1 preferably has an integrally formed, one-piece construction, and can be made from metal, such as aluminum or the like, as well as synthetic materials, such as vinyl. As best illustrated in FIG. 3, sidewalls 7 are oriented at a predetermined acute angle with respect to both base portion 2 and top wall 6. Preferably, the predetermined acute angle of sidewalls 7 is in the range of 20 to 70 degrees. The illustrated sidewalls 7 are disposed at a predetermined acute angle of approximately 60 degrees. The illustrated sidewalls 7 are substantially identical in size and oriented at a similar angle with respect to base portion 2 and top wall 6, so as to define a generally regular trapezoidal shape. In the example illustrated in FIGS. 1-3, the top wall 6 of vent channel 5 is substantially imperforate, and therefore does not permit air to pass there through. Top wall 6 does not have any visually detectable openings or apertures, but rather has an appearance substantially identical with the exterior surface of base portion 2, such that the same match. Top wall 6 is disposed in a generally horizontal orientation when vented soffit panel 1 is installed under an eave 4. In the example illustrated in FIGS. 1-3, each of the sidewalls 7 is perforate, and therefore permits air to pass therethrough. The illustrated sidewalls 7 include a plurality of apertures 25, which have a generally circular plan shape, and are oriented perpendicularly with respect to the associated sidewalls 7. Apertures 25 are sized to permit ambient air to flow freely through sidewalls 7, yet prevent bugs and other debris from entering soffit 3. Preferably, apertures 25 have a diameter in the range of 0.080 to 0.100 inches, and in the illustrated example have a diameter of around 0.094 inches. The illustrated apertures 25 are arranged in a plurality of mutually staggered rows, which provide around 21 apertures 25 per running inch in the orientation illustrated in FIG. 6. As will be apparent to those skilled in the art, while the illustrated soffit panel 1 has a plurality of circular apertures 25 in sidewalls 7 to render the same perforate, sidewalls 7 may be equipped with other forms of vents, such as elongate slits, rectangular windows, and the like, to permit air to pass therethrough. With reference to FIGS. 4-7, the illustrated vented soffit panel 1 has a substantially rectangular plan configuration, defined by a front edge 30, a rear edge 31, and opposing side edges 32 and 33. The illustrated vented soffit panel 1 also includes a plurality of vent channels 5 extending along the depth of base portion 2. More specifically, the vented soffit panel 1 illustrated in FIGS. 4-7 includes two vent channels 5, which extend along the depth of vented soffit panel 1 in a mutually spaced apart relationship at a medial portion of base portion 2. Furthermore, vented soffit panel 1 includes connector flanges 34 and 35, which extend along the side edges 32 and 33 respectively of vented soffit panel 1. Connector flange 34 includes an inclined sidewall 36, whose shape, size, and orientation are substantially identical to the sidewalls 7 of vent channel 5. Connector flange 34 also includes a narrow receptor slot 37, formed by overlapping portions of connector flange 34, which is shaped to receive therein the connector flange 35 of an adjacent vented soffit panel 1, in the manner illustrated in FIG. 7. The top wall 38 of connector flange 34 is coplanar with the top wall 6 of vent channel 5, and includes a downwardly oriented protrusion of detent 39 adjacent the free end thereof which is adapted to abut and frictionally engage the connector flange 35 of the next adjacent vented soffit panel 1 to securely interconnect the same in a side-by-side relationship. The sidewall 36 of connector flange 35 may also be perforated in a manner similar to the sidewall 7 of vent channel 5 to provide additional venting. Connector flange 35 also includes an inclined sidewall 40, which is similar in shape, size, and orientation to sidewalls 7 of vent channel 5, as well as the sidewall 36 of connector flange 34, and may also be provided with perforations for additional venting. The top wall 41 of connector flange 35 is also coplanar with the top wall 6 of vent channels 5. In one working embodiment of the present invention, elongate sheets of aluminum having a length of around 12 feet and a width of around 13-14 inches are roll formed into the shape illustrated in FIG. 1, and then cut lengthwise into segments having a length equal to the depth of the eve to be covered. For example, the vented soffit panel 1 shown in FIG. 1 has a depth, as measured between edges 30 and 31 in the range of 12-36 inches, and a width, as measured between side edges 32 and 33, of approximately 13¼ inches. The height of vent channel 5, as measured between base portion 2 and top wall 6, is around 0.46 inches, while the width of slot 9, as measured between the lower ends 8 of adjacent sidewalls 7, is around 0.26 inches. Vent channels 5, as well connector flanges 34 and 35, are spaced apart on four inch centers, and the staggered rows of apertures are spaced apart around 0.13 inches. Vented soffit panels 1 are installed under the eave 4 of building roof 17 in the following manner. The rear edge 31 of each vented soffit panel 1 is positioned along ledger board 20, with vent channels 5 oriented upwardly. The front edge 30 of each vented soffit panel 1 is positioned along the interior surface of fascia board 18, and may be attached to the same, as well as to the lower surfaces of rafters 19. Vented soffit panels 1 are arranged in a side-by-side fashion, with the connector flange 35 of each soffit panel 1 being inserted into the connector flange 34 of the next adjacent soffit panel, so as to interconnect the same in a substantially flat or planar condition. When vented soffit panels 1 are so installed, the perforate sidewalls 7 of vent channels 5, and/or sidewalls 36 and 40 of connector flanges 34 and 35 are concealed or hidden from view from a position underneath the eave. The angular orientation of sidewalls 7, in combination with the size of slot 9, prevents apertures 25 from being seen from a position underneath the eave, so as to greater improve the aesthetics of the building construction. Vented soffit panel 1 thereby provides improved aesthetics by hiding from view apertures 25 and/or other perforate structures to permit air to flow therethrough. Yet, vented soffit panel 1 prevents insects, bugs, and other debris from entering the soffit 3 or eave 4. The vented soffit panel 1 has an uncomplicated design, is easy to install, economical to manufacture, and very durable. In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise. | <SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to building construction, and in particular to a vented soffit panel and related method for buildings and the like. Soffit panels are generally well-known in the art, and serve to cover or enclose the underside of the eaves of homes and other buildings of the type having roof eaves which extend beyond and hang over the outside walls of the building. The purpose of the soffit panels is to hide the eaves from view, and prevent the use of the underside of the eaves as a nesting place for insects, birds and the like. In modern day building construction, the soffit is normally vented to allow outside air to flow into the attic of the building to equalize the attic temperature and pressure with that of the outside environment. This equalization helps to prevent degradation of the roof, reduce moisture accumulation, and improve the heating and cooling efficiency for the building interior. While some soffit panels are perforated or louvered to facilitate venting, they possess certain drawbacks. One such disadvantage is that insects, such as bees, bugs and the like, can get through the vents, and use the soffit as a nesting place. Debris can also become lodged in the vents to impede the free flow of air into the eave. Furthermore, such prior soffit panels normally have exposed or visible vents, thereby detracting from the overall appearance of the structure. Consequently, a soffit panel which overcomes these problems would be advantageous. | <SOH> SUMMARY OF THE INVENTION <EOH>One aspect of the present invention is a vented soffit panel for buildings and the like, which includes a generally flat imperforate base portion shaped to enclose at least a portion of the building soffit when mounted in a generally horizontal orientation under an eave. At least one vent channel protrudes upwardly from the base portion, and has a generally trapezoidal shape defined by horizontal imperforate top wall and inclined perforate sidewalls with lower ends that connect with the base portion in a spaced apart relationship to define a slot through which air flows to vent the eave. The perforate sidewalls are disposed at an acute angle, such that they are hidden from view from a position underneath the eave. Another aspect of the present invention is a method for venting building roofs and the like of the type having at least one eave with a soffit thereunder. The method comprises forming a plurality of vented soffit panels, each having a generally flat imperforate base portion shaped to enclose at least a portion of the soffit when mounted in a generally horizontal orientation under the eave, and at least one vent channel portion extending along the base portion, and protruding upwardly therefrom, wherein the vent channel portion has a generally trapezoidal lateral cross-sectional shape defined by a generally horizontal imperforate top wall and inclined perforate sidewalls with lower ends connected with the base portion in a mutually spaced apart relationship to define a slot therebetween through which ambient air enters into the vent channel and flows through the perforate sidewalls to vent the eave, wherein the perforate sidewalls are disposed at a predetermined acute angle relative to the top wall and the base portion. The method further includes installing the soffit panels in a side-by-side, generally horizontal position under the eave, such that the eave is enclosed, and the perforate sidewalls of the vented soffit panels are hidden from view from a position underneath the eave. Yet another aspect of the present invention is a vented soffit panel which has a hidden venting structure for improved aesthetics, yet prevents insects, bugs and other debris from entering the soffit or eave. The vented soffit panel has an uncomplicated design, is easy to install, and economical to manufacture. Preferably, the vented soffit panel is constructed from roll formed aluminum or the like to provide a very lightweight, yet durable, product. These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims, and appended drawings. | 20040216 | 20061121 | 20050818 | 99551.0 | 1 | MANAF, ABDUL | VENTED SOFFIT PANEL AND METHOD FOR BUILDINGS AND LIKE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,778,534 | ACCEPTED | Apparatus for detecting a pointer within a region of interest | An apparatus for detecting a pointer within a region of interest includes at least one pair of imaging devices. The imaging devices have overlapping fields of view encompassing the region of interest. At least one light source provides illumination across the region of interest and is within the field of view of at least one of the imaging device. A filter is associated with the at least one imaging device whose field of view sees the light source. The filter blocks light projected by the light source to inhibit the imaging device from being blinded by the projected light. | 1. An apparatus for detecting a pointer within a region of interest comprising: at least one pair of imaging devices, said imaging devices having overlapping fields of view encompassing said region of interest; at least one light source providing illumination across said region of interest and being within the field of view of at least one of said imaging devices; and a filter associated with the at least one imaging device whose field of view sees said light source, said filter blocking light projected by said light source to inhibit said imaging device from being blinded by said projected light. 2. An apparatus according to claim 1 wherein said filter blocks light having a characteristic different from a characteristic assigned to the at least one imaging device. 3. An apparatus according to claim 2 wherein said characteristic includes at least one of polarization and frequency. 4. An apparatus according to claim 2 including a light source associated with each imaging device, each light source being in the field of view of the non-associated imaging device, light projected by each light source being visible to said associated imaging device and being blocked by a filter associated with the non-associated imaging device. 5. An apparatus according to claim 4 wherein said characteristic includes at least one of polarization and frequency. 6. An apparatus according to claim 5 wherein the light source associated with one imaging device projects illumination having a first polarization orientation and wherein the light source associated with the other imaging device projects illumination having a second polarization orientation. 7. An apparatus according to claim 6 wherein the first and second polarization orientations are vertical and horizontal polarization orientations. 8. An apparatus according to claim 2 wherein said region of interest overlies a touch surface on which pointer contacts are made. 9. An apparatus according to claim 8 wherein said touch surface and region of interest are rectangular. 10. An apparatus according to claim 9 including a light source associated with each imaging device, each light source being in the field of view of the non-associated imaging device, light projected by each light source being visible to said associated imaging device and being blocked by a filter associated with the non-associated imaging device. 11. An apparatus according to claim 10 wherein said characteristic includes at least one of polarization and frequency. 12. An apparatus according to claim 11 wherein the light source associated with one imaging device projects illumination having a first polarization orientation and wherein the light source associated with the other imaging device projects illumination having a second polarization orientation. 13. An apparatus according to claim 12 wherein the first and second polarization orientations are vertical and horizontal polarization orientations. 14. An apparatus for detecting a pointer within a region of interest comprising: at least one pair of imaging devices, said imaging devices having overlapping fields of view looking generally across said region of interest; a light source associated with each imaging device, each said light source providing illumination across said region of interest and being in the field of view of the non-associated imaging device; and a filter device associated with each imaging device so that substantially only light projected by the light source associated therewith is received by said associated imaging device. 15. An apparatus according to claims 14 further comprising a filter device associated with each light source to alter a characteristic of projected light such that the projected light is unable to pass through the filter device associated with the non-associated imaging device. 16. An apparatus according to claim 15 wherein said filter devices are polarizers. 17. An apparatus according to claim 16 wherein each light source is an infrared light source. 18. An apparatus according to claim 17 wherein each infrared light source includes at least one infrared light emitting diode (IR LED). 19. An apparatus according to claim 15 further comprising: retro-reflective elements bordering said region of interest, said retro-reflective elements returning light impinging thereon in the direction of impingement without altering the polarization thereof. 20. An apparatus according to claim 15 wherein said region of interest overlies a touch surface on which pointer contacts are made. 21. An apparatus according to claim 20 wherein said touch surface and region of interest are rectangular. 22. An apparatus according to claim 21 wherein said filter devices are polarizers. 23. An apparatus according to claim 22 including an imaging device and associated light source at each corner of said region of interest, diagonally opposite imaging devices being aimed generally at one another. 24. An apparatus according to claim 23 wherein one of the diagonally opposite polarizers has a vertical orientation and wherein the other of the diagonally opposite polarizers has a horizontal orientation. 25. An apparatus for detecting a pointer within a region of interest comprising: an imaging device adjacent at least two corners of said region of interest, the imaging devices having overlapping fields of view looking generally across said region of interest, said imaging devices being configured to capture light having a particular characteristic; and a light source associated with each imaging device, each said light source projecting light across said region of interest having a characteristic of the type capturable by said associated imaging device. 26. An apparatus according to claim 25 wherein each light source is an infrared light source. 27. An apparatus according to claim 26 wherein each infrared light source includes at least one infrared light emitting diode (IR LED). 28. An apparatus according to claim 25 wherein said region of interest overlies a touch surface on which pointer contacts are made. 29. An apparatus according to claim 28 wherein said touch surface and region of interest are rectangular. 30. An apparatus according to claim 29 wherein said imaging devices are configured to capture light having different polarizations. 31. An apparatus according to claim 30 wherein said different polarizations are vertical and horizontal. 32. An apparatus for detecting a pointer within a region of interest comprising: at least two color imaging devices having overlapping fields of view looking generally across said region of interest; processing circuitry receiving and processing images acquired by said imaging devices to detect the existence of a pointer in said images and to determine the location of said pointer relative to said region of interest; and at least one illumination source projecting light in a specified frequency range across said region of interest thereby to provide lighting for said imaging devices, wherein said color imaging devices are sensitive to ambient light to capture color images and are sensitive to the light projected by said at least one illumination source to capture monochrome images. 33. An apparatus according to claim 32 wherein said illumination source is operated to project light when ambient light levels fall below a threshold level. 34. An apparatus according to claim 33 wherein said illumination source projects light in the infrared range. 35. An apparatus according to claim 32 said illumination source projects light in the infrared range. 36. An apparatus according to claim 35 wherein said region of interest overlies a touch surface. 37. An apparatus according to claim 36 wherein said illumination source is operated to project light when ambient light levels fall below a threshold level. 38. An apparatus according to claim 32 wherein said region of interest overlies a touch surface. 39. An apparatus for detecting a pointer contact on a generally rectangular touch surface comprising: a color imaging device at each corner of said touch surface and having a field of view looking generally across said touch surface; processing circuitry receiving and processing images acquired by said imaging devices to detect the existence of a pointer in said images and to determine the location of said pointer relative to said region of interest; and illumination sources surrounding said touch surface and projecting light in a specified frequency range across said touch surface thereby to provide backlighting for said imaging devices, wherein said color imaging devices are sensitive to ambient light to capture color images and are sensitive to the light projected by said illumination sources to capture monochrome images. 40. An apparatus according to claim 39 wherein said illumination sources are operated to project light when ambient light levels fall below a threshold level. 41. An apparatus according to claim 40 wherein said illumination sources project light in the infrared range. 42. An apparatus for detecting a pointer within a region of interest comprising: at least two monochrome imaging devices having overlapping fields of view looking generally across said region of interest; processing circuitry receiving and processing images acquired by said imaging devices to detect the existence of a pointer in said images and to determine the location of said pointer relative to said region of interest; and at least one illumination source projecting light across said region of interest; and at least one filter changing the frequency band of light in a cycle thereby to enable said imaging devices to capture images looking across said region of interest in different lighting conditions. 43. An apparatus according to claim 42 wherein said illumination source projects light of different frequencies across said region of interest in a repeating cycle. 44. An apparatus according to claim 43 wherein said illumination source projects infrared, red, blue, and green light in a cycle across said region of interest. | FIELD OF THE INVENTION The present invention relates generally to interactive systems and in particular to an apparatus for detecting a pointer within a region of interest. BACKGROUND OF THE INVENTION Touch systems are well known in the art and typically include a touch screen having a touch surface on which contacts are made using a pointer such as for example a pen tool, finger or other suitable object. Pointer contacts with the touch surface are detected and are used to generate output pointer position data representing areas of the touch surface where pointer contacts are made. International PCT Application No. PCT/CA01/00980 filed on Jul. 5, 2001 and published under number WO 02/03316 on Jan. 10, 2002, assigned to SMART Technologies Inc., assignee of the present invention, discloses a passive camera-based touch system. The camera-based touch system comprises a touch screen that includes a touch surface on which a computer-generated image is presented. A rectangular bezel or frame surrounds the touch surface and supports digital cameras at its comers. The digital cameras have overlapping fields of view that encompass and look across the touch surface. The digital cameras acquire images of the touch surface from different locations and generate image data. The image data is processed by digital signal processors to determine if a pointer exists in the captured image data. When it is determined that a pointer exists in the captured image data, the digital signal processors convey pointer characteristic data to a master controller, which in turn processes the pointer characteristic data to determine the location of the pointer in (x,y) coordinates relative to the touch surface using triangulation. The pointer location data is conveyed to a computer executing one or more application programs. The computer uses the pointer location data to update the computer-generated image that is presented on the touch surface. Pointer contacts on the touch surface can therefore be recorded as writing or drawing or used to control execution of an application program executed by the computer. Although this camera-based touch system works extremely well, it has been found that when the digital camera frame rates are high, in less favorable light conditions, the ability to determine the existence of a pointer in the captured image data is diminished. As a result, there exists a need to improve the lighting environment for the digital cameras to ensure high resolution irrespective of ambient lighting conditions. U.S. patent application Ser. No. 10/354,168 to Akitt et al. entitled “Illuminated Bezel And Touch System Incorporating The Same”, assigned to SMART Technologies Inc., assignee of the present invention, discloses an illuminated bezel for use in the above-described camera-based touch system. The illuminated bezel projects infrared backlighting across the touch surface that is visible to the digital cameras. As a result, when no pointer is positioned within the fields of view of the digital cameras, the digital cameras see bright bands of illumination as a result of the projected backlighting. When a pointer is positioned within the fields of view of the digital cameras, the pointer occludes the backlight illumination. Therefore, in each captured image the pointer appears as a high-contrast dark region interrupting the bright band of illumination allowing the existence of the pointer in the captured image to be readily detected. Although the illuminated bezel works very well, because the illuminated bezel completely surrounds the touch surface and makes use of an array of infrared light emitting diodes mounted on a printed circuit board that is disposed behind a diffuser, manufacturing costs are significant especially in cases where the illuminated bezel surrounds large touch surfaces. As will be appreciated, lower cost backlight illumination for touch systems of this nature is desired. Also, although the existence of the pointer in captured images can be readily detected, currently the use of monochrome digital cameras to capture images increases costs and provides limited information concerning attributes of the pointer used to contact the touch system. It is therefore an object of the present invention to provide a novel apparatus for detecting a pointer within a region of interest. SUMMARY OF THE INVENTION Accordingly, in one aspect of the present invention, there is provided an apparatus for detecting a pointer within a region of interest comprising: at least one pair of imaging devices, said imaging devices having overlapping fields of view encompassing said region of interest; at least one light source providing illumination across said region of interest and being within the field of view of at least one of said imaging devices; and a filter associated with the at least one imaging device whose field of view sees said light source, said filter blocking light projected by said light source to inhibit said imaging device from being blinded by said projected light. In one embodiment, the filter blocks light having a characteristic different from a characteristic assigned to the at least one imaging device. The characteristic may be one of polarization and frequency. The apparatus may include a light source associated with each imaging device, with each light source being in the field of view of the non-associated imaging device. Light projected by each light source is visible to its associated imaging device but is blocked by the filter associated with the non-associated imaging device. The region of interest may overlie a touch surface on which pointer contacts are made, with imaging devices and associated light sources being provided adjacent each comer of the touch surface. According to another aspect of the present invention there is provided an apparatus for detecting a pointer within a region of interest comprising: at least one pair of imaging devices, said imaging devices having overlapping fields of view looking generally across said region of interest; a light source associated with each imaging device, each said light source providing illumination across said region of interest and being in the field of view of the non-associated imaging device; and a filter device associated with each imaging device so that substantially only light projected by the light source associated therewith is received by said associated imagining device. According to still yet another aspect of the present invention there is provided an apparatus for detecting a pointer within a region of interest comprising: an imaging device adjacent at least two corners of said region of interest, the imaging devices having overlapping fields of view looking generally across said region of interest, said imaging devices being configured to capture light having a particular characteristic; and a light source associated with each imaging device, each said light source projecting light across said region of interest having a characteristic of the type capturable by said associated imaging device. According to still yet another aspect of the present invention there is provided an apparatus for detecting a pointer within a region of interest comprising: at least two color imaging devices having overlapping fields of view looking generally across said region of interest; processing circuitry receiving and processing images acquired by said imaging devices to detect the existence of a pointer in said images and to determine the location of said pointer relative to said region of interest; and at least one illumination source projecting light in a specified frequency range across said region of interest thereby to provide lighting for said imaging devices, wherein said color imaging devices are sensitive to ambient light to capture color images and are sensitive to the light projected by said at least one illumination source to capture monochrome images. According to still yet another aspect of the present invention there is provided an apparatus for detecting a pointer contact on a generally rectangular touch surface comprising: a color imaging device at each corner of said touch surface and having a field of view looking generally across said touch surface; processing circuitry receiving and processing images acquired by said imaging devices to detect the existence of a pointer in said images and to determine the location of said pointer relative to said region of interest; and illumination sources surrounding said touch surface and projecting light in a specified frequency range across said touch surface thereby to provide backlighting for said imaging devices, wherein said color imaging devices are sensitive to ambient light to capture color images and are sensitive to the light projected by said illumination sources to capture monochrome images. According to still yet another aspect of the present invention there is provided an apparatus for detecting a pointer within a region of interest comprising: at least two monochrome imaging devices having overlapping fields of view looking generally across said region of interest; processing circuitry receiving and processing images acquired by said imaging devices to detect the existence of a pointer in said images and to determine the location of said pointer relative to said region of interest; and at least one illumination source projecting light across said region of interest; and at least one filter changing the frequency band of light in a cycle thereby to enable said imaging devices to capture images looking across said region of interest in different lighting conditions. The present invention provides advantages in that in one embodiment, backlight illumination is provided across the touch surface in an effective and cost efficient manner. The present invention provides further advantages in that since images looking across the region of interest can be acquired at different frequency bands of light, in addition to determining the location of the pointer, increased pointer attribute information can be easily obtained. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be described more fully with reference to the accompanying drawings in which: FIG. 1 is a schematic diagram of an apparatus for detecting a pointer within a region of interest; FIG. 2 is a front elevation view of a touch screen forming part of the apparatus of FIG. 1; FIG. 3 is another front elevation view of the touch screen of FIG. 2; FIG. 4 is a schematic diagram of a digital camera forming part of the touch screen of FIG. 2; FIG. 5 is a schematic diagram of a master controller forming part of the apparatus of FIG. 1; FIG. 6 is a front elevational view of an alternative embodiment of the touch screen; FIG. 7 is a front elevational view of yet another embodiment of the touch screen; and FIG. 8 is a graph showing the light sensitivity of digital cameras used in the touch screen of FIG. 7. DETAILED DESCRIPTION OF THE INVENTION Turning now to FIGS. 1 to 3, an apparatus for detecting a pointer within a region of interest in accordance with the present invention is shown and is generally identified by reference numeral 50. In this embodiment, apparatus 50 is a camera-based touch system similar to that disclosed in International PCT Application Serial No. WO 02/03316, assigned to SMART Technologies Inc., assignee of the present invention, the content of which is incorporated herein by reference. As can be seen, touch system 50 includes a touch screen 52 coupled to a digital signal processor (DSP) based master controller 54. Master controller 54 is also coupled to a computer 56. Computer 56 executes one or more application programs and generates computer-generated image output that is presented on the touch screen 52. The touch screen 52, master controller 54 and computer 56 form a closed-loop so that pointer contacts made on the touch screen 52 can be recorded as writing or drawing or used to control execution of an application programs executed by the computer 56. FIGS. 2 and 3 better illustrate the touch screen 52. Touch screen 52 in the present embodiment includes a high-resolution display device such as a plasma display 58, the front surface of which defines a touch surface 60. The touch surface 60 is bordered by a bezel or frame 62 coupled to the display device. Comer pieces 68 that house DSP-based CMOS digital cameras 70 are located at each corner of the bezel 62. Each digital camera 70 is mounted within its respective corner piece 68 so that its field of view encompasses and looks generally across the entire plane of the touch surface 60. An infrared light source 72 is associated with and positioned adjacent each digital camera 70. Each light source 72 includes an array of infrared (IR) light emitting diodes (LEDs). The light emitting diodes project infrared lighting across the touch surface 60. Polarizers 74 are provided in front of the digital cameras 70 and the infrared light sources 72. The polarization of the polarizers 74 at opposite corners of the touch surface 60 have opposite polarization. For example, in this embodiment, the polarizers 74 at the top and bottom left comers of the touch surface 60 have a vertical orientation and the polarizers 74 at the top and bottom right corners of the touch surface 60 have a horizontal orientation. In this manner, the polarizers 74 minimize the light projected by the diagonally opposite infrared light sources 72 that is seen by the digital cameras 70 i.e. block the diagonally opposite infrared light sources 72 from their fields of view thereby to avoid digital camera photo-saturation and other effects that reduce the effectiveness of the digital cameras 70. One of the digital cameras 70 within a corner piece 68 is shown in FIG. 4. As can be seen, the digital camera 70 includes a two-dimensional CMOS image sensor and associated lens assembly 80, a first-in-first-out (FIFO) buffer 82 coupled to the image sensor and lens assembly 80 by a data bus and a digital signal processor (DSP) 84 coupled to the FIFO 82 by a data bus and to the image sensor and lens assembly 80 by a control bus. A boot EPROM 86 and a power supply subsystem 88 are also included. In the present embodiment, the CMOS camera image sensor is configured for a 20×640 pixel subarray that can be operated to capture image frames at high frame rates in excess of 200 frames per second since arbitrary pixel rows can be selected. Also, since the pixel rows can be arbitrarily selected, the pixel subarray can be exposed for a greater duration for a given digital camera frame rate allowing for good operation in dark rooms as well as well lit rooms. The DSP 84 provides control information to the image sensor and lens assembly 80 via the control bus. The control information allows the DSP 84 to control parameters of the image sensor and lens assembly 80 such as exposure, gain, array configuration, reset and initialization. The DSP 84 also provides clock signals to the image sensor and lens assembly 80 to control the frame rate of the image sensor and lens assembly 80. An infrared pass filter 89 is provided on the image sensor and lens assembly 80 to blind the digital camera 70 to frequencies of light outside the infrared range. Master controller 54 is better illustrated in FIG. 5 and includes a DSP 90, a boot EPROM 92, a serial line driver 94 and a power supply subsystem 95. The DSP 90 communicates with the DSPs 84 of the digital cameras 70 over a data bus via a serial port 96 and communicates with the computer 56 over a data bus via a serial port 98 and the serial line driver 94. The master controller 54 and each digital camera 70 follow a communication protocol that enables bidirectional communications via a common serial cable similar to a universal serial bus (USB). Communications between the master controller 54 and the digital cameras 70 are performed as background processes in response to interrupts. The operation of the touch system 50 will now be described. To provide appropriate lighting for the digital cameras 70, the infrared light source 72 associated with each digital camera 70 generates infrared light that is projected across the touch surface 60 covering an area at least as large as the field of view of the associated digital camera. As mentioned previously, the polarizers 74 at opposite diagonal corners of the touch surface 60 inhibit the infrared light source 72 diagonally opposite each digital camera 70 from blinding that digital camera due to the different polarization orientations of the polarizers 74. Infrared light impinging on a polarizer 74 that is polarized in a manner different from the polarization orientation of the polarizer is blocked. In this manner, the digital camera 70 behind each polarizer 74 in effect does not see the infrared light source 72 at the diagonally opposite comer. Each digital camera 70 acquires images looking across the touch surface 60 within the field of view of its image sensor and lens assembly 80 at a desired frame rate and processes each acquired image to determine if a pointer is in the acquired image. When a pointer is positioned within the fields of view of the digital cameras 70, the pointer is illuminated by the light projected by the infrared light sources 72. Light reflecting off of the pointer typically does not maintain its polarization and therefore is visible to the digital cameras 70. Therefore, the illuminated pointer appears as a high-contrast bright region interrupting a dark band in each captured image allowing the existence of the pointer in the captured images to be readily detected. If a pointer is in the acquired image, the image is further processed to determine characteristics of the pointer contacting or hovering above the touch surface 60. Pointer information packets (PIPs) including pointer characteristics, status and/or diagnostic information are then generated by the digital cameras 70 and the PIPs are queued for transmission to the master controller 54. The master controller 54 polls the digital cameras 70 for PIPs. If the PIPs include pointer characteristic information, the master controller 54 triangulates pointer characteristics in the PIPs to determine the position of the pointer relative to the touch surface 60 in Cartesian rectangular coordinates. The master controller 54 in turn transmits calculated pointer position data, status and/or diagnostic information to the computer 56. In this manner, the pointer position data transmitted to the computer 56 can be recorded as writing or drawing or can be used to control execution of an applications program executed by the computer 56. The computer 56 also updates the computer-generated image output conveyed to the plasma display 58 so that information presented on the touch surface 60 reflects the pointer activity. Specifics concerning the processing of acquired images and the triangulation of pointer characteristics in PIPs are described in U.S. patent application Ser. No. 10/294,917 to Morrison et al., assigned to SMART Technologies Inc., assignee of the present invention, the content of which is incorporated herein by reference. Accordingly, specifics will not be described further herein. As will be appreciated, the use of infrared light sources 72 and polarizers 74 at the corners of the touch surface 60 inhibit light sources in the fields of view of the digital cameras from blinding the digital cameras. Turning now to FIG. 6, another embodiment of a touch screen is shown and is generally identified by reference numeral 152. Tough screen 152 is similar to that of the previous embodiment but in this case the bezel 162 is designed to allow the touch screen 152 to operate in an occlusion mode. As can be seen, bezel 162, in this embodiment, includes elongate retro-reflectors 164 bordering the sides of the touch surface 160. The retro-reflectors 164 have retro-reflecting surfaces 166 lying in planes that are generally normal to the plane of the touch surface 160. The retro-reflectors 164 are designed to maintain polarization of light impinging thereon. In the present embodiment, corner cube retroreflectors such as those manufactured by Reflexite Corporation and sold under the name Reflexite™ AP1000 that preserve polarization are used. In this embodiment, when infrared light generated by the infrared light sources 172 travels across the touch surface and impinges on one or more retro-reflectors 164, the retro-reflectors 164 in turn reflect the infrared light back in the opposite direction while maintaining the polarization of the infrared light. Since the infrared light sources 172 are mounted adjacent the digital cameras 170, infrared light reflected by the retro-reflectors 164 is aimed back towards the digital cameras 170. As a result, each digital camera 170 sees a bright band of illumination within its field of view. During image acquisition, when no pointer is positioned within the fields of view of the digital cameras 170, the digital cameras 170 see bright bands of illumination. When a pointer is positioned within the fields of view of the digital cameras 170, the pointer occludes the infrared illumination and therefore appears as a high-contrast dark region interrupting a bright band of illumination in each captured image allowing the existence of the pointer in the captured images to be readily detected. The embodiments of the touch screen described above show digital cameras, infrared light sources and polarizers at each comer of the touch screen. Those of skill in the art will appreciate that only two imaging devices having overlapping fields of view are required. Also the infrared light sources need not be positioned adjacent the digital cameras. In addition other types of filters may be used to inhibit the digital cameras from being blinded by a light source within its field of view. Basically any filter type device that blocks light projected by a light source within the field of view of the digital camera based on a characteristic (i.e. polarization, frequency etc.) of the projected light may be used. In addition, although each light source is described as including an array of IR LEDs, those of skill in the art will appreciate that other light source configurations to provide light illumination across the touch surface can be used. Although the touch system 50 has been described as including a plasma display 58 to present images on the touch surface, those of skill in the art will appreciate that this is not required. The touch screen may be a rear or front projection display device or virtually any surface on which a computer generated image is projected. Alternatively, the touch system 50 may be a writeboard where images are not projected on the touch surface. Also, although the touch system 50 is described as including a master controller 54 separate from the digital cameras, if desired one of the digital cameras can be conditioned to function as both a camera and the master controller and poll the other digital cameras for PIPs. In this case, the digital camera functioning as the master controller may include a faster DSP 84 than the remaining digital cameras. Turning now to FIG. 7, yet another embodiment of a touch screen is shown and is generally identified by reference numeral 252. In this embodiment, touch screen 252 includes a high-resolution display device such as a plasma display 258, the front surface of which defines a touch surface 260. The touch surface 260 is bordered by an illuminated bezel or frame 262 coupled to the display device. Illuminated bezel 262 is of the type disclosed in U.S. patent application Ser. No. 10/354,168 to Akitt et al., assigned to SMART Technologies Inc., assignee of the present invention, the content of which is incorporated by reference. Illuminated bezel 262 includes elongate side frame assemblies 264 that are coupled to the sides of the plasma display 258. Each side frame assembly 264 accommodates a generally continuous infrared illumination source 266. The ends of the side frame assemblies 264 are joined by corner pieces 268 that house DSP-based CMOS digital cameras 270. Each digital camera 270 is mounted within its respective corner piece 268 so that its field of view encompasses and looks generally across the entire touch surface 260. Each illuminated bezel 262 includes an array of IR LEDs (not shown) that project light onto a diffuser (not shown). The diffuser in turn, diffuses and expands the infrared light emitted by the IR LEDs so that adequate infrared backlighting is projected across the touch surface 260. As a result, the illuminated bezels 162 appear as generally continuous bright bands of illumination to the digital cameras 270. Rather than using monochrome digital cameras capturing infrared images, in this embodiment, the image sensors used in the digital cameras 270 are color CMOS image sensors and do not include IR pass filters. FIG. 8 shows the light sensitivity of one of the image sensors. As can be seen, the sensitivity of the image sensor to red, green and blue light is localized around the appropriate frequencies. However at light in the infrared range i.e. about 850 nm, the color filters of the image sensors become transparent making the sensitivity of all of the pixels of the image sensors basically equal. This characteristic of the image sensor allows the touch screen to be operated in a number of modes depending on ambient light levels as will now be described. For example, in one mode of operation when the ambient light level is sufficiently high, the illuminated bezels 262 are switched off allowing color images to be acquired by the digital cameras 270. During image processing, in addition to determining the pointer position in the manner described previously, acquired color information is used to enhance pointer recognition and scene understanding. As will be appreciated, when an image including a pointer is captured, the foreground object i.e. the pointer, is the object of interest. During image processing, it is desired to separate the foreground object from the background. Since the optical properties of the foreground object and background are different for different wavelengths of light, the foreground object is detected easier in some light frequencies than others. For example, if the background is predominantly blue, then the foreground object such as a finger will have higher luminosity when looking through red or green filters since the blue filter does not permit blue light to pass. This effectively segments the foreground object from the background. In general, the luminosity differences between the foreground object and the background are exploited at different frequencies. When the ambient light level drops below a threshold level, the illuminated bezels 262 are switched on. In this case, the touch screen 252 operates in an occlusion mode as described previously. Pointer data is developed from images captured by the image sensors and processed in the manner discussed above. Although the touch screen 252 has been described as using infrared illumination to provide backlighting, those of skill in the art will appreciate that light in a different frequency range other than infrared may be used provided the image sensors in the digital cameras have sufficient quantum efficiency at that different frequency range to capture images. Rather than exclusively using ambient light when the ambient light level is sufficiently high and infrared illumination when the ambient light level is low, infrared illumination can be multiplexed with ambient light to enable the digital cameras 270 to capture different types of images. For example, the illuminated bezels 262 can be strobed so that one or more images are captured by the digital cameras 270 in ambient light conditions and then in infrared backlighting conditions. The strobing may be achieved by shutting the illuminated bezels 262 on and off and relying on ambient light levels in the off condition. Alternatively, rather than using colour image sensors, monochrome sensors may be used in conjunction with an illumination source that provides lighting across the touch surface that changes frequency bands allowing one or more images to be captured by the digital cameras in the different frequency bands. For example, the illumination source may include a white light source and a light filter in the form of a wheel that is rotatable in front of the light source. The wheel may include alternating infrared and clear sections. When a clear section is presented in front of the light source, white light is projected across the touch surface and when an infrared section is presented in front of the light source, infrared light is projected across the touch surface. Other light filters can of course be used with the wheel. For example, the wheel may include infrared, blue, red and green sections arranged about the wheel. Depending on the section of the wheel positioned in front of the light source, light in a different frequency band is projected across the touch surface allowing one or more images to be captured during each type of illumination. Of course, those of skill in the art will appreciate that colour wheels may be disposed in front of the digital cameras rather than adjacent the light source. Although embodiments of the present invention have been described, those of skill in the art will appreciate that variations and modifications may be made without departing from the spirit and scope thereof as defined by the appended claims. | <SOH> BACKGROUND OF THE INVENTION <EOH>Touch systems are well known in the art and typically include a touch screen having a touch surface on which contacts are made using a pointer such as for example a pen tool, finger or other suitable object. Pointer contacts with the touch surface are detected and are used to generate output pointer position data representing areas of the touch surface where pointer contacts are made. International PCT Application No. PCT/CA01/00980 filed on Jul. 5, 2001 and published under number WO 02/03316 on Jan. 10, 2002, assigned to SMART Technologies Inc., assignee of the present invention, discloses a passive camera-based touch system. The camera-based touch system comprises a touch screen that includes a touch surface on which a computer-generated image is presented. A rectangular bezel or frame surrounds the touch surface and supports digital cameras at its comers. The digital cameras have overlapping fields of view that encompass and look across the touch surface. The digital cameras acquire images of the touch surface from different locations and generate image data. The image data is processed by digital signal processors to determine if a pointer exists in the captured image data. When it is determined that a pointer exists in the captured image data, the digital signal processors convey pointer characteristic data to a master controller, which in turn processes the pointer characteristic data to determine the location of the pointer in (x,y) coordinates relative to the touch surface using triangulation. The pointer location data is conveyed to a computer executing one or more application programs. The computer uses the pointer location data to update the computer-generated image that is presented on the touch surface. Pointer contacts on the touch surface can therefore be recorded as writing or drawing or used to control execution of an application program executed by the computer. Although this camera-based touch system works extremely well, it has been found that when the digital camera frame rates are high, in less favorable light conditions, the ability to determine the existence of a pointer in the captured image data is diminished. As a result, there exists a need to improve the lighting environment for the digital cameras to ensure high resolution irrespective of ambient lighting conditions. U.S. patent application Ser. No. 10/354,168 to Akitt et al. entitled “Illuminated Bezel And Touch System Incorporating The Same”, assigned to SMART Technologies Inc., assignee of the present invention, discloses an illuminated bezel for use in the above-described camera-based touch system. The illuminated bezel projects infrared backlighting across the touch surface that is visible to the digital cameras. As a result, when no pointer is positioned within the fields of view of the digital cameras, the digital cameras see bright bands of illumination as a result of the projected backlighting. When a pointer is positioned within the fields of view of the digital cameras, the pointer occludes the backlight illumination. Therefore, in each captured image the pointer appears as a high-contrast dark region interrupting the bright band of illumination allowing the existence of the pointer in the captured image to be readily detected. Although the illuminated bezel works very well, because the illuminated bezel completely surrounds the touch surface and makes use of an array of infrared light emitting diodes mounted on a printed circuit board that is disposed behind a diffuser, manufacturing costs are significant especially in cases where the illuminated bezel surrounds large touch surfaces. As will be appreciated, lower cost backlight illumination for touch systems of this nature is desired. Also, although the existence of the pointer in captured images can be readily detected, currently the use of monochrome digital cameras to capture images increases costs and provides limited information concerning attributes of the pointer used to contact the touch system. It is therefore an object of the present invention to provide a novel apparatus for detecting a pointer within a region of interest. | <SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, in one aspect of the present invention, there is provided an apparatus for detecting a pointer within a region of interest comprising: at least one pair of imaging devices, said imaging devices having overlapping fields of view encompassing said region of interest; at least one light source providing illumination across said region of interest and being within the field of view of at least one of said imaging devices; and a filter associated with the at least one imaging device whose field of view sees said light source, said filter blocking light projected by said light source to inhibit said imaging device from being blinded by said projected light. In one embodiment, the filter blocks light having a characteristic different from a characteristic assigned to the at least one imaging device. The characteristic may be one of polarization and frequency. The apparatus may include a light source associated with each imaging device, with each light source being in the field of view of the non-associated imaging device. Light projected by each light source is visible to its associated imaging device but is blocked by the filter associated with the non-associated imaging device. The region of interest may overlie a touch surface on which pointer contacts are made, with imaging devices and associated light sources being provided adjacent each comer of the touch surface. According to another aspect of the present invention there is provided an apparatus for detecting a pointer within a region of interest comprising: at least one pair of imaging devices, said imaging devices having overlapping fields of view looking generally across said region of interest; a light source associated with each imaging device, each said light source providing illumination across said region of interest and being in the field of view of the non-associated imaging device; and a filter device associated with each imaging device so that substantially only light projected by the light source associated therewith is received by said associated imagining device. According to still yet another aspect of the present invention there is provided an apparatus for detecting a pointer within a region of interest comprising: an imaging device adjacent at least two corners of said region of interest, the imaging devices having overlapping fields of view looking generally across said region of interest, said imaging devices being configured to capture light having a particular characteristic; and a light source associated with each imaging device, each said light source projecting light across said region of interest having a characteristic of the type capturable by said associated imaging device. According to still yet another aspect of the present invention there is provided an apparatus for detecting a pointer within a region of interest comprising: at least two color imaging devices having overlapping fields of view looking generally across said region of interest; processing circuitry receiving and processing images acquired by said imaging devices to detect the existence of a pointer in said images and to determine the location of said pointer relative to said region of interest; and at least one illumination source projecting light in a specified frequency range across said region of interest thereby to provide lighting for said imaging devices, wherein said color imaging devices are sensitive to ambient light to capture color images and are sensitive to the light projected by said at least one illumination source to capture monochrome images. According to still yet another aspect of the present invention there is provided an apparatus for detecting a pointer contact on a generally rectangular touch surface comprising: a color imaging device at each corner of said touch surface and having a field of view looking generally across said touch surface; processing circuitry receiving and processing images acquired by said imaging devices to detect the existence of a pointer in said images and to determine the location of said pointer relative to said region of interest; and illumination sources surrounding said touch surface and projecting light in a specified frequency range across said touch surface thereby to provide backlighting for said imaging devices, wherein said color imaging devices are sensitive to ambient light to capture color images and are sensitive to the light projected by said illumination sources to capture monochrome images. According to still yet another aspect of the present invention there is provided an apparatus for detecting a pointer within a region of interest comprising: at least two monochrome imaging devices having overlapping fields of view looking generally across said region of interest; processing circuitry receiving and processing images acquired by said imaging devices to detect the existence of a pointer in said images and to determine the location of said pointer relative to said region of interest; and at least one illumination source projecting light across said region of interest; and at least one filter changing the frequency band of light in a cycle thereby to enable said imaging devices to capture images looking across said region of interest in different lighting conditions. The present invention provides advantages in that in one embodiment, backlight illumination is provided across the touch surface in an effective and cost efficient manner. The present invention provides further advantages in that since images looking across the region of interest can be acquired at different frequency bands of light, in addition to determining the location of the pointer, increased pointer attribute information can be easily obtained. | 20040217 | 20070619 | 20050818 | 64519.0 | 0 | WILLIAMS, DON J | APPARATUS FOR DETECTING A POINTER WITHIN A REGION OF INTEREST | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,778,601 | ACCEPTED | Vehicle lamp | A vehicle lamp can include a plurality of light source modules each having an LED as a light source, and optical systems for distributing light from each of the light source modules frontward toward predetermined areas or predetermined patterns that are different from each other and which make up a light distribution pattern. Each of the optical systems can be optimized to emit light to a predetermined area, and each of the light source modules' LEDs can be optimally arranged for each of the corresponding optical systems. | 1. A vehicle lamp comprising: a plurality of light source modules each having an LED as a light source; and optical systems for distributing light from each of the light source modules frontward and toward respective predetermined areas that are different from each other and that form a light distribution pattern, wherein each of the optical systems is optimized for distributing the light to one of said predetermined areas, and wherein each of the LEDs of the light source modules is optimally arranged for a corresponding optical system. 2. The vehicle lamp according to claim 1, wherein each of the light source modules and each of the optical systems emit light to one of a converged area and a diverged area of the light distribution pattern 3. The vehicle lamp according to claim 1, wherein each of the light source modules and each of the optical systems emit light to one of a converged area, a diverged area and an intermediate area of the light distribution pattern. 4. The vehicle lamp according to claim 2, wherein the light source module for emitting light to the converged area of the light distribution pattern includes a shading member having a shape that is substantially the same as a light distribution pattern for a low beam vehicle headlight and has a corresponding optical system, and wherein the corresponding optical system includes a projector lens for converging light. 5. The vehicle lamp according to claim 2, wherein the light source module for emitting light to the diverged area of the light distribution pattern is configured to produce light having a shape that includes one linear ridge line and that is elongated in one direction, the light source for emitting light to the diverged area having a corresponding optical system, and wherein the corresponding optical system includes a reflector for condensing light from the light source module by reflecting the light. 6. The vehicle lamp according to claim 3, wherein the optical system for emitting light to the intermediate area of the light distribution pattern includes a reflector and a projector lens that are configured to produce light at a juncture between the converged area and diverged area such that the converged area and the diverged area are smoothly connected to each other. 7. The vehicle lamp according to claim 1, wherein the light source modules and the optical systems are configured to emit light to a light distribution area of a sub-lamp. 8. The vehicle lamp according to claim 7, wherein the light distribution area of the sub-lamp is one of a light distribution area of a daytime running lamp, a light distribution area of a fog lamp, and a light distribution area of a cornering lamp. 9. The vehicle lamp according to claim 1, wherein the light source modules and the optical systems are configured to be removable and reconfigurable for emitting light to a selectable light distribution area. 10. The vehicle lamp according to claim 1, wherein each of the light source modules is an integral unit separate from each other, for which the number of LEDs, and the configuration of the light source modules are optimized for a corresponding one of said predetermined areas. 11. A vehicle lamp comprising: a first light source module having an LED as a light source, a first optical system located adjacent the first light source module; a second light source module having an LED as a light source; a second optical system located adjacent the second light source module, wherein the first light source module and corresponding first optical system are configured to emit light in a first pattern, and the second light source module and corresponding second optical system are configured to emit light in a second pattern that is different from the first pattern. 12. The vehicle lamp according to claim 11, wherein the first pattern is not symmetrical and is elbow shaped. 13. The vehicle lamp according to claim 11, further comprising: a third light source module having an LED as a light source; and a third optical system located adjacent the third light source module, wherein the third light source module and corresponding third optical system are configured to emit light in a third pattern, and the third pattern is different from the first pattern and the second pattern. 14. The vehicle lamp according to claim 11, wherein the first light source module emits light to a converged area of a light distribution pattern and includes a shading member having a shape that is substantially the same as a light distribution pattern for a low beam, and the corresponding first optical system includes a projector lens configured to converge light. 15. The vehicle lamp according to claim 11, wherein the second light source module is configured to emit light to a diverged area of a light distribution pattern, the second pattern of light having a shape that is elongated and includes one linear ridge line, and wherein the corresponding second optical system includes a reflector configured to condense light from the light source module. 16. The vehicle lamp according to claim 13, wherein the third optical system includes a reflector and a projector lens that are configured to produce light at a juncture between the first pattern of light and second pattern of light such that contrast between the first pattern and second pattern is diminished. 17. The vehicle lamp according to claim 13, wherein the first, second and third light source modules and the first, second and third optical systems are configured to emit light to a sub-lamp light distribution pattern that is different from a low beam light distribution pattern for a vehicle headlight. 18. The vehicle lamp according to claim 13, wherein the first, second and third light source modules and the first, second and third optical systems are configured to emit light to a low-beam light distribution pattern for a vehicle headlight, the low-beam light distribution pattern being non-symmetrical and substantially elbow shaped. 19. The vehicle lamp according to claim 11, wherein the first and second light source modules and the first and second optical systems are configured to be removable and reconfigurable for emitting light to selectable and different light distribution patterns. 20. The vehicle lamp according to claim 11, wherein each of the light source modules is an integral unit separate from each other, for which the number of LEDs, and the configuration of the light source module are optimized for a desired light pattern. | This invention claims the benefit of Japanese Patent Application No. 2003-364866, filed on Oct. 24, 2003, which is hereby incorporated by reference. 1. Field of the Invention The present invention relates to a vehicle lamp, and more particularly to a vehicle headlight such as a headlight and a sub-headlight using a plurality of LED devices as the light source. 2. Description of Related Art In recent years, with the increase of power and intensity of white LEDs, white LEDs have been considered for use as the light source for a vehicle lamp. The advantages of using the LEDs are expected to be the acquisition of a non-replaceable light source, lowering of power consumption and size-reduction of the lighting fixture itself. However, though the power of white LEDs has increased, for each individual LED light source both the luminous flux and the intensity are low compared to an individual conventional light source using an electric discharge lamp, such as a halogen lamp, an HID lamp, etc. The luminous flux of a white LED is approximately {fraction (1/20)} of that of a halogen lamp and approximately {fraction (1/60)} of that of an HID lamp in the present situation. Furthermore, since it may be difficult, even in the future, for the flux and the intensity of an LED to reach those equal to those of an HID lamp, it is preferable to make a vehicle lamp with an optical system that uses a plurality of LEDs in order to use an LED as a light source of a vehicle lamp. A vehicle lamp as described above, for example a conventional vehicle lamp as shown in FIGS. 25-27, will now be described. First, a vehicle lamp 1 shown in FIG. 25 comprises a light source module 2 in which a plurality of LEDs 2a are arranged and mounted on the surface of a substrate having a dented shape facing the front. A projector lens 3 is arranged in front of the light source module 2, and a shading member 4 is arranged in the vicinity of the focusing position F on the light source side of the projector lens 3. Each of the LEDs 2a of the above light source module 2 is respectively arranged such that its optical axis is directed to the focusing position F of the projector lens 3 and is respectively adapted to be illuminated by being supplied with a driving current from a driving unit (not shown). The projector lens 3 comprises a convex lens and is adapted to converge and frontwardly emit the light irradiated from each of LEDs 2a of the light source module 2. The shading member 4 has an edge 4a formed such that it forms a cut-off to create a light distribution pattern for a low beam. According to the vehicle lamp having such a structure, each of the LEDs 2a of the light source module 2 is illuminated by being supplied with a driving current, and the light irradiated from each of the LEDs 2a respectively travels toward the focusing position F of the projector lens 3 and is converged and emitted frontward by the projector lens 3. In this case, as shown in FIG. 26, due to the shading member 4 forming a cut-off, the above mentioned light is emitted frontward and within the area of a light distribution pattern L for a so-called low beam. Thereby, the vehicle lamp is configured such that it does not give any glaring or dazzling light to oncoming cars and pedestrians when used as a headlamp. A vehicle lamp 5 shown in FIG. 27 comprises a light source module comprising a plurality of LEDs 6a arranged circumferentially around a central axis extending frontward. A reflector 7 reflects light from the light source module 6 towards the front. A projector lens 3 causes the reflected light from the reflector 7 to converge, and a shading member 4 forms a cut-off for dipped light-distribution. As shown in FIG. 27 (B), each of the LEDs 6a of the light source module 6 is arranged such that its optical axis extends from the central axis in an outward radial direction. The reflector 7 comprises, for example, an ellipsoid of revolution, and each of the LEDs 6a of the light source module 6 is arranged in the vicinity of a first focusing position of the surface, and a second focusing position of the surface is in the vicinity of a focusing position on the light source side of the projector lens 3. According to the vehicle lamp 5 having such a structure, each of the LEDs 6a of the light source module 6 is illuminated by being supplied with a driving current. The light irradiated from each of the LEDs 6a is respectively reflected by the reflector 7 and travels toward the second focus of the reflector 7, i.e., a focusing position F of the projector lens 3. Then, the light is caused to converge by the projector lens 3, and is emitted frontward. In this case, as shown in FIG. 26, due to a cut-off formed by the shading member 4, the light is emitted frontward within the area of a light distribution pattern L for a so-called low beam. Thus, the vehicle lamp is configured such that it does not give any glaring or dazzling light to oncoming cars and pedestrians, when configured as a headlight. However, for a vehicle lamp 1 having such a structure, it has not been suitable to employ LEDs as light sources since the lamp comprises an optical system based on a halogen lamp or an electric discharge lamp. It has been difficult to form a desired light distribution pattern with the LEDs. Therefore, it has also been difficult to efficiently use the light irradiated from each of the LEDs and emit the light frontward. Furthermore, as shown in FIG. 26, a luminous intensity of, for example, 6,000-20,000 cd is preferable for a low beam of a headlight in the vicinity of the central area. In contrast, in an optical system in which light is caused to converge by a projector lens, the value of the luminous intensity is in proportion to the density of light (luminous flux divergence) in vicinity of a focusing position of the projector lens and the area of the lamp fitting. Therefore, in the case where an LED (which has a considerably lower intensity compared to an electric discharge lamp such as a halogen lamp or an HID lamp) is used as a light source, the optical system becomes considerably large in order to obtain the above-mentioned luminous intensity with a conventional optical system using a reflector and a projector lens as described above. In the case of a vehicle lamp 1 shown in FIG. 25, the density of light in the vicinity of a focusing position F becomes low as the distance increases between each of the LEDs 2a of the light source module 2 and a focusing position F of the projector lens 3. Therefore, it is difficult to obtain a high luminous intensity. In contrast, as the light source module 2 and the focusing position F are made closer to each other, the number of the LEDs 2a capable of being integrated on the light source module 2 becomes fewer. In this manner, for the vehicle lamp 1, in any case, it is difficult to obtain a desired luminous intensity. Furthermore, in the case of the vehicle lamp 5 shown in FIG. 27, each of the LEDs 6a of the light source module 6 is projected and enlarged by the reflector 7, and it is difficult to obtain a desired luminous intensity as well. In contrast, for example, a conventional vehicle lamp 8 shown in FIG. 28 can be considered. In FIG. 28, the vehicle lamp 8 has a structure in which a reflector 9b, a projector lens 9c and a shading member 9d are provided adjacent each of a plurality of LEDs 9a arranged in a matrix of horizontal rows and vertical columns. An image of each of the LEDs 9a is projected frontward by the reflector 9b and a projector lens 9c corresponding to each of the LEDs 9a. However, for the vehicle lamp 8, the optical system comprising the reflector 9b and the projector lens 9c is also not suitable for employing an LED as the light source because it has a structure based on a halogen lamp or an electric discharge lamp, similar to the case of the vehicle lamp 5 discussed above. Furthermore, for each of the vehicle lamps 1, 5 and 8, shading members 4 or 9d are provided in order to form a light distribution pattern of a low beam, e.g., a light beam which illuminates more brightly on one side of the road (in the case of driving on the left, the left side) so as not to dazzle or blind the drivers of oncoming cars. By cutting unnecessary light with the shading member 4 or 9d, the vehicle lamps are adapted to obtain the light distribution pattern of the above-mentioned low beam. In this case, in order to form a cut-off against the light distribution pattern of the low beam, it is necessary to form the cut-off with the shading member 4 or 9d at the location in the vicinity of the optical axis of each of the LEDs 2a, 6a and 9a, where the luminous intensity is highest. Therefore, for example, an amount of light close to approximately 40% is cut by the shading member 4 or 9d from the emitted light amount from each of the LEDs 2a, 6a and 9a, resulting in a substantial loss of light. Therefore, the LED's optical characteristic of plane illumination can not be utilized and the efficiency of light use is very low. On the contrary, when a vehicle lamp is adapted to control its light distribution pattern only with the reflector 7 or 9b without using the shading members 4 and 9d, the efficiency of light use can be increased by up to approximately 70% since the loss can be minimized. However, it is difficult to obtain a sufficient contrast at the border of light and shade on an H line (horizontal line) and elbow line (an inclined line of 15 degrees) since the intensity of each LED is low. SUMMARY OF THE INVENTION In view of the foregoing, an aspect of the present invention includes a lamp or vehicle lamp suitable for a headlight, a sub-headlight, tail light, or other vehicle lamp, etc. configured to obtain a desired light distribution pattern using a plurality of LED devices as light sources. According to another aspect of the present invention there is provided a vehicle lamp that can include a plurality of light source modules each having an LED as a light source; and-optical systems for emitting light from each of the light source modules frontward toward predetermined areas of a light distribution pattern, the predetermined areas being different from each other, wherein each of the optical systems can be optimized to emit the light to a predetermined area, and wherein the LEDs of the light source modules can be arranged optimally for the optical systems corresponding thereto. Preferably, each of the light source modules and each of the optical systems respectively emit light to a converged area and a diverged area of the light distribution pattern. In addition, it is preferable that each of the light source modules and each of the optical systems respectively emit light to a converged area, a diverged area and an intermediate area of the light distribution pattern. Preferably, the light source module for emitting light to the converged area of the light distribution pattern includes a shading member having a shape similar to that of the light distribution pattern of a low beam, and the optical system corresponding thereto can be composed of a projector lens for converging light. The light source module for emitting light to the diverged area of the light distribution pattern preferably has a shape for illumination having one linear ridge line and is elongated in one direction, and the optical system corresponding thereto preferably includes a reflector for condensing light from the light source module by reflecting the light. The optical system for emitting light to the intermediate area of the light distribution pattern is preferably composed of a reflector and a projector lens such that the light distribution characteristics of the converged area and the diverged area are smoothly connected to each other. The light source module and the optical system can be optimized for emitting light to a light distribution area of a sub-lamp. The light distribution area of the sub-lamp can be a light distribution area of a daytime running lamp, a fog lamp, a cornering lamp, etc. The light source module and the optical system can be arranged in a removable fashion and optimized for emitting light to an arbitrary or even light distribution area Each of the respective light source modules can be configured as a different kind of package as compared to each other, for which the number of LEDs, the arrangement and the composition can be optimized for the light distribution area for each respective light source module in order to efficiently emit light. According to the above structure, a light distribution pattern can be divided into a plurality of areas, and a light source module and an optical system can be provided for each of the areas. Then, by optimizing each of the light source modules and each of the optical system for their corresponding area respectively, a light distribution characteristic can be obtained in which each of the areas of the light distribution pattern respectively has desired luminous intensity distribution. Thereby, the vehicle lamp as a whole can form a desired light distribution pattern having desired luminous intensity distribution by virtue of the plurality of combinations of the light source modules and the optical systems. In this case, by optimizing each of the LEDs of each of the light source modules together with the optical system for their corresponding area of the light distribution pattern, the efficiency of light usage from each of the LEDs can be increased and brighter emitted light can be obtained. When each of the above light source modules and optical systems emit light respectively to the converged area and the diverged area of the light distribution pattern, they can respectively emit light to the converged area and the diverged area in desired light distribution by optimizing each of the light source modules and each of the optical systems respectively for the converged area and the diverged area of the light distribution pattern. Thereby, as a whole, a light distribution pattern having desired luminous intensity distribution can be formed. When each of the above light source modules and optical systems emit light respectively to the converged area, the diverged area and an intermediate area of the light distribution pattern, they can respectively emit light to the converged area, the diverged area and the intermediate area in desired luminous intensity distribution by optimizing each of the light source modules and each of the optical systems respectively for the converged area, the diverged area and the intermediate area of the light distribution pattern. Thereby, as a whole, a light distribution pattern having desired luminous intensity distribution can be formed and, at the same time, the converged area and the diverged area can be continuously connected by the intermediate area in a smoothly varying contrast. In the case where a light source module for emitting light to the converged area of the above light distribution pattern is provided with a shading member having the same shape as that of the light distribution pattern of the low beam, and an optical system corresponding to the module includes a projector lens for converging light, a cut-off can be formed by a shading member. The shading member can be located to block light from each LED of the light source module and, further, the shape of the emission formed by the cut-off can be converged by the projector lens and emitted frontward. Thereby, in a simple structure, it is possible to, for example, form a border of light and shade having a high contrast in the vicinity of the center. Therefore, it is possible to form a light distribution pattern suitable for the converged area. In the case where a light source module for emitting light to a diverged area of the above light distribution pattern has an illuminating shape having one linear ridge line and is elongated along one direction, and an optical system corresponding to the light source module includes a reflector for reflecting light from the light source module, utilizing, for example, a light source module in which LED chips are arranged in a line, the linear ridge line is reflected by the reflector and emitted frontward. Therefore, the light from the light source module can be efficiently reflected frontward. At the same time, a high-contrast border of light and shade can be formed by projecting the linear ridge line into the vicinity of a cut-off line. Thereby, it is possible to form a light distribution pattern diverging in the horizontal direction (the cut-off line has a difference in light and shade) and suitable for the diverged area. Furthermore, since the light source module is substantially plane-illuminating and fully-diverging illuminating, the reflector does not need to cover the entire light source and can have a substantially planar shape. Therefore, the vehicle lamp can be made thin. In the case where an optical system for emitting light to the intermediate area of the above light distribution pattern includes a reflector and a projector lens such that the light distribution characteristics of the converged area and the diverged area are connected continuously and smoothly, the light is diverged by the reflector and is converged by the projector lens and emitted frontward while being slightly diverged. Since the cut-off is formed by a shading board at a lens focus, it is possible to smoothly connect a light distribution pattern forming a high-contrast border of light and shade in the converged area with a light distribution pattern diverging horizontally in the diverged area. Furthermore, in the case where a light source module and an optical system optimized for emitting light to a light distribution area of a sub-lamp are provided and, preferably, the light distribution area of the sub-lamp is a daytime-running lamp distribution area, fog lamp distribution area or a cornering lamp distribution area, the light source module and the optical system can be directly incorporated in the vehicle lamp. Therefore, it is possible to implement a function of a sub-lamp in the vehicle lamp itself, and the entire lamp fitting for a vehicle can be made very small. As a result, the degree of freedom for lamp design and lamp fitting for a vehicle is increased. Furthermore, in the case where a light source module and an optical system optimized for emitting light to an arbitrary light distribution area are removably arranged, it is possible to add or remove functions of a sub-lamp or other lamp fittings for a vehicle as necessary. Therefore, it is possible to easily manufacture a lamp fitting for a vehicle provided with arbitrary functions. As indicated, each light source module can be structured as a different kind of package for which the number, the arrangement and the structure of LED chips are optimized, respectively, corresponding to a light distribution area in order to efficiently emit light. Therefore, a vehicle lamp can be made by combining different types of such packages. In this manner, by virtue of a light source module employing an LED as a light source, light from each of the LEDs can be emitted to a predetermined area in a light distribution pattern through the corresponding optical system. In this case, since the light source module and the optical system are optimized in terms of each corresponding area of the light distribution pattern, it is possible to realize a light distribution characteristic having a desired shape of illumination and intensity distribution. Therefore, even when an LED, which typically has a lower intensity compared to an electric discharge lamp such as a halogen lamp or an HID lamp, is used as a light source, a sufficient maximum luminous intensity can be obtained. Therefore, it is possible to realize a highly efficient, small and thin vehicle lamp. Furthermore, since a desired light distribution characteristic can be formed by combining light source modules, the degree of freedom of light distribution and the degree of freedom of the design of the vehicle lamp can be increased. Another aspect of the invention includes a vehicle lamp that has: a first light source module having an LED as a light source; a first optical system located adjacent the first light source module; a second light source module having an LED as a light source; a second optical system located adjacent the second light source module, wherein the first light source module and corresponding first optical system are configured to emit light in a first pattern, and the second light source module and corresponding second optical system are configured to emit light in a second pattern that is different from the first pattern. The vehicle lamp can also include a first pattern that is not symmetrical and is elbow shaped. In addition, a third light source module can be provided an LED as a light source; and a third optical system can be located adjacent the third light source module, wherein the third light source module and corresponding third optical system are configured to emit light in a third pattern, and the third pattern being different from the first pattern and the second pattern. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, aspects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. 1 is a schematic diagram illustrating the composition of an embodiment of a vehicle lamp made in accordance with the principles of the present invention; FIG. 2 is a schematic perspective view illustrating the composition of a set of lighting units of the vehicle lamp shown in FIG. 1; FIG. 3 is an enlarged perspective view illustrating a light source module of the set of lighting units shown in FIG. 2; FIG. 4 is a schematic side view illustrating a modification of the set of lighting units shown in FIG. 2: FIG. 5 is a graph showing a light distribution pattern formed by the set of lighting units shown in FIG. 4; FIG. 6 is a schematic perspective view illustrating another embodiment of the lighting units of the vehicle lamp shown in FIG. 1; FIG. 7 is a schematic diagram showing an example of the shape of an illuminating unit of a light source module of the set of lighting units shown in FIG. 6; FIG. 8 is a schematic diagram showing a projected image of the light source of the set of lighting units shown in FIG. 6; FIG. 9 is a graph showing a light distribution pattern formed by the set of lighting units shown in FIG. 6; FIG. 10 is a schematic diagram showing another example of the shape of the illuminating unit of the light source module of the set of lighting units shown in FIG. 6; FIG. 11 is a schematic view showing yet another example of the shape of the illuminating unit of the lighting source module of the set of lighting units shown in FIG. 6; FIG. 12 is a schematic side view illustrating another embodiment of the lighting unit of the vehicle lamp shown in FIG. 1; FIG. 13 is a schematic side view illustrating another embodiment of the lighting unit of the vehicle lamp shown in FIG. 1; FIG. 14 is a schematic side view illustrating yet another embodiment of the lighting unit of the vehicle lamp shown in FIG. 1; FIG. 15 is a schematic side view illustrating a modification of the embodiment of the lighting unit shown in FIG. 12; FIG. 16 is a schematic side view illustrating another modification of the embodiment of the lighting unit shown in FIG. 12; FIG. 17 is a schematic diagram showing the composition of another embodiment of a vehicle lamp made in accordance with the principles of the present invention; FIG. 18 is a schematic perspective view illustrating a set of lighting units for a vehicle lamp as shown in FIG. 17; FIG. 19 is a schematic perspective view illustrating another set of lighting units for a vehicle lamp as shown in FIG. 17; FIG. 20 is a schematic perspective view illustrating yet another set of lighting units for a vehicle lamp as shown in FIG. 17; FIG. 21 is a graph showing a light distribution pattern formed by the set of lighting units as shown in FIG. 18; FIG. 22 is a graph showing a light distribution pattern formed by the set of lighting units as shown in FIG. 19; FIG. 23 is a graph showing a light distribution pattern formed by the set of lighting units as shown in FIG. 20; FIG. 24 is a graph showing a light distribution pattern formed by the vehicle lamp as shown in FIG. 17; FIG. 25 is a schematic side view illustrating the composition of an example of a conventional vehicle lamp; FIG. 26 is a graph schematically showing a light distribution pattern for a low beam; FIGS. 27(A) and (B) are a schematic side view and partial front view, respectively, illustrating the composition of another example of a conventional vehicle lamp; and FIGS. 28(A) and (B) are a schematic side view and front view, respectively, illustrating the composition of yet another example of a conventional vehicle lamp. Preferred embodiments of the present invention will be described in detail referring to FIGS. 1-24. Since the embodiments described herein below are preferred specific examples and embodiments of the present invention, there are various technically preferred limitations given thereto. However, the scope of the present invention is not limited to these aspects or limitations unless otherwise described. FIG. 1 shows the composition of an embodiment of a vehicle lamp made in accordance with the principles of the present invention. In FIG. 1, a vehicle lamp 10 can include three sets 11, 21 and 31 of lighting units. The first set 11 of the lighting units is preferably adapted to emit light to a converged area having maximal luminous intensity and including borders of light and shade, such as an elbow line, in a light distribution pattern of a so-called low beam. The second set 21 of the lighting units can be adapted to emit light to a diverged area. The diverged area being a wide area for which no elbow line is necessary, in the above light distribution pattern. Furthermore, the third set 31 of lighting units can be adapted to emit light to an intermediate area that is located between the above areas such that it smoothly connects the contrast of the light distribution in the above converged area and the diverged area in the above light distribution pattern. First, the first set of the lighting units 11 for the converged area will be described. As shown in FIG. 2, the first set of the lighting units 11 can include a light source module 12 and an optical system 13. As shown in FIG. 3, the light source module 12 can be provided with an illuminating unit 12a that includes an LED formed by surrounding an LED chip with fluorescent material and which can be packaged by a lens house 12b made of; for example, resin. The above illuminating unit 12a can be arranged such that, by being supplied with external power through a lead 12c, light emitted from an LED chip strikes fluorescent material and a mixed-color light that includes both the light emitted directly from the LED chip and the light emitted by excitation of the fluorescent material is emitted from the illuminating unit 12a. The light source module 12 can also include a core 12f made from a core material, such as a copper core material. The above described light source module 12 can further be provided with a lens 12d and a shading member 12e located at the front of the illuminating unit 12a. A cut-off can be formed by cutting out or blocking light emitted from the illuminating unit 12a with the shading member 12e. Therefore, by projecting using a horizontal line and a convex lens (projector lens), an elbow line extending obliquely upward at an angle of, for example, 15 degrees from the center, can be formed, which is a characteristic of a light distribution pattern of a low beam. The above described optical system 13 can be formed as a projector lens that includes a convex lens and, as shown in FIG. 2, arranged such that its optical axis is aligned on the central axis of the light source module 12. The optical system's focusing position can be located on the light source side and positioned in the vicinity of the shading member 12e in front of the illuminating unit 12a of the light source module 12. Thereby, light from each LED 12a of the light source module 12 can be converged frontward by the optical system 13. Therefore, the light can form a light distribution pattern area (converged area) indicated by the symbol “La” in FIG. 2. Here, since the optical system 13 is preferably a condensing optical system, it is possible to use condensing optical systems having other compositions. However, since the maximum value of luminous intensity in a converged area in a light distribution pattern is preferably in proportion to the intensity in the vicinity of a focus of the secondary optical system, i.e., the optical system 13 and the area of the optical system 13, the maximum intensity can be obtained most efficiently with a composition shown in FIG. 2, in which the illuminating unit 12a of the light source module 12 is projected directly to the converged area by a projector lens. In contrast, in the case where a focusing position of the projector lens is disposed in the vicinity of the shading member 12e which is located in the vicinity of the outer surface of the lens of the light source module, the intensity is considerably lowered. Therefore, the maximum value of the luminous intensity is also considerably lowered. In the case of an optical system in which an image of the illuminating unit 12a is imaged in the vicinity of the shading member 12e using a relay lens, and the image is projected toward the converged area by the projector lens, the optical system is complicated, and the cost of parts and cost for assembling are increased. Furthermore, the depth of the whole vehicle lamp is large and the intensity of the image of the illuminating unit 12a at the focusing position is lowered and, therefore, the maximum value of luminous intensity is also lowered. Here, it is difficult for the first set of the lighting units 11 to give arbitrary or even intensity distribution in the converged area of the light distribution pattern. Therefore, as shown in FIG. 4, by providing the first set of lighting units 11 with a plurality (in the case shown, four (4)) illuminating units 11a, 11b, 11c and 11d, light L1, L2, L3 and L4 from light source modules 12a′, 12b′, 12c′ and 12d′ is respectively emitted frontward by optical systems 13a, 13b, 13c and 13d, each having focus distances respectively different from each other. Thereby, as shown in FIG. 5, a light distribution characteristic having intensity distribution, i.e., gradation as a whole, can be provided by setting the range to be emitted for each of the illuminating units 11a, 11b, 11c and 11d to be properly overlapped. Next, a set of lighting units 21 for the diverged area will be described. As shown in FIG. 6, the set of lighting units 21 can include a light source module 22 and an optical system 23. The light source module 22 can be provided with an illuminating unit 22a having an illuminating shape having one (1) or more linear ridge line(s) such as, for example, a rectangle composed of an LED. The optical system 23 can include a reflector having a combination of concave surfaces, e.g., surfaces dented frontward. For example, the reflector can include a combination of a paraboloid of revolution and an ellipsoid of revolution and can be arranged such that its focusing position is positioned in the vicinity of the illuminating unit 22a of the light source module 22 opposing over the axis of the light source module 22. Thereby, light from the illuminating unit 22a of the light source module 22 can be reflected by the optical system 23 and can form the light distribution pattern area (diverged area) indicated by the symbol “Lb” in FIG. 6. The light source module 22 can be plane-illuminating and, utilizing the advantage of having Lambertian directivity, the efficiency of light use emitted from the illuminating unit 22a of the light source module 22 can be approximately 70% or more. A desired light distribution pattern can be formed by properly selecting the shape of the reflector. By projecting light frontward by the optical system 23 by arranging the linear ridge line of the illuminating unit 22a of the light module 22 in a horizontal direction, the ridge line can form a cut-off for a horizontal line of the light distribution pattern Furthermore, the set of lighting units 21 preferably includes an optical system 23 that has a multi-reflector divided into a plurality of reflecting faces. By forming each of the reflecting faces properly, the illuminating unit 22a of the light source module 22 can be projected as shown in FIG. 8. Thus the projected image of the illuminating unit 22a can be rotated depending on the position where light is reflected. Thereby, the diverged area of the light distribution pattern can be provided with a light distribution characteristic having intensity distribution, i.e., gradation, as shown in FIG. 9, by allowing projected images of the illuminating unit 22a formed by each reflecting face to overlap each other. The shape of the illuminating unit 22a of the light source module 22 is not limited to a rectangle and, as shown in FIG. 10, may be formed such that it has an outer shape of an approximate semicircle. As shown in FIG. 11, the shape of the illuminating unit 22a can be formed such that a plurality of LED chips are lined up in a particular direction. Another set of lighting units 31 will now be described. As shown in FIG. 12, a set of lighting units 31 can include a light source module 32 and an optical system 33. The light source module 32 can have a composition that does not include the shading member 12e from the light source module 12 in FIG. 2. The surface of the illuminating unit 12a can be arranged along the optical axis of the optical axis of the optical system 33. There is no limitation for the shape of the illuminating unit 32a of the light source module 32. However, it is preferable that the illuminating unit 32a be as small and as high-intensity as possible in order to improve the efficiency of incidence to a projector lens 33b of the optical system 33, and to further downsize the size of the optical system 33. The optical system 33 can include a reflector 33a, a projector lens 33b and a shading member 33c. The reflector 33a can include, for example, an ellipsoid of revolution and can be arranged such that a focusing position on one hand is positioned in the vicinity of the center of the illuminating unit 32a of the light source module 32, and the other focusing position on the other hand can be positioned in front on the optical axis of the optical system 33. The projector lens 33b can be a convex lens and can be arranged such that its focusing position on the light source side is positioned in the vicinity of a focusing position on the front side of the reflector 33a. Furthermore, the shading member 33c can be arranged in the vicinity of a focusing position on the light source side of the projector lens 33b and its edge 33d can be adapted to form a cut-off with its upper end. In the composition described above, the illuminating unit 32a is preferably arranged facing upward and the reflector 33a is preferably arranged in the upper half portion. However, the composition is not limited to this configuration and, as shown in FIG. 13, in addition to the above illuminating unit 32a, a reflector 33a′ facing downward may be provided along with a reflector 33a′ in the lower half portion facing vertically to the reflector 32a. Furthermore, as shown in FIG. 14, a shading member 33c may be arranged along the optical axis to form a cut-off with the front end of its edge 33d. Thereby, light incident to a portion of the surface of the shading member 33d can be reflected and emitted frontward. Accordingly, the efficiency of light use can be improved by 50% or more. As shown in FIG. 15, in order to improve the contrast at the cut-off line, the illuminating unit 32a may be arranged to be slightly inclined backward. In the optical system shown in FIG. 16, the LED light source can be plane-illuminating and, when the reflecting faces are either present only above or below the center of the lens, light is incident to either an area below or above the center of the projector lens 33b. Therefore, by cutting off the upper half portion or the lower half portion of the projector lens 33b, downsizing in the vertical direction can be facilitated. In addition, when a plurality of lighting units 31 are arranged to vertically overlap each other in order to obtain a light distribution pattern having a higher intensity, they can be arranged more densely in the vertical orientation. The vehicle lamp 10 according to embodiments of the present invention can include lighting units 11, 21 and 31 which are illuminated by being supplied with power, respectively. Thereby, the light irradiated from the illuminating unit 12a of the light source module 12 can have the cut-off formed by the shading member 12e and be condensed by the projector lens of the optical system 13, and can be emitted frontward to form the converged area “La” of the light distribution pattern. The light irradiated from the illuminating unit 22a of the light source module 22 can be emitted frontward by being reflected by the reflector of the optical system 23 and can thus form the diverged area “Lb” of the light distribution pattern. Furthermore, the light irradiated from the illuminating unit 32a of the light source module 32 can be reflected by the reflector 33a of the optical system 33, can be further converged by the projector lens 33b and be concurrently given the cut-off formed by the shading member 33c, and can be emitted frontward to form the intermediate area between the converged area “La” and the diverged area “Lb.” Thereby, the reflected light from each of the lighting units 11, 21 and 31 can overlap each other and can form the light distribution pattern of a so-called low beam. The plurality of areas of the light distribution pattern, i.e., the converged area, the diverged area and the intermediate area can be respectively formed by the lighting units 11, 21, and 31. Here, since each of the lighting units 11, 21 and 31 is optimized for its respective corresponding area, each of the areas and the whole light distribution pattern can be formed in a desired luminous intensity distribution and at maximum luminous intensity. In this manner, a desired light distribution pattern such as, for example, a light distribution of a so-called low beam can be obtained using a plurality of LEDs as the vehicle lamp's light source. FIG. 17 shows the composition of another embodiment of a vehicle lamp made in accordance with the principles of the present invention. In FIG. 17, vehicle lamp 40 is a specific embodiment of the vehicle lamp 10 described above. Similar to the vehicle lamp 10 shown in FIG. 1, the vehicle lamp 40 can include three sets of lighting units 41, 51 and 61. A first set of lighting units 41 corresponding to a converged area can be composed to be almost the same as the set of lighting units 11 of the vehicle lamp shown in FIG. 1 and can be adapted to emit light to the range from 8 degrees on the left to 8 degrees on the right. The set of lighting units 51 corresponding to a diverged area can be composed to be almost the same as the set of lighting units 21 of the vehicle lamp shown in FIG. 1 and can be adapted to emit light to the range from 50 degrees on the left to 50 degrees on the right. Furthermore, the lighting units 61 corresponding to an intermediate area can be composed to be almost the same as the set of lighting units 31 of the vehicle lamp shown in FIG. 1 and can be adapted to emit light to the range from 20 degrees on the left to 20 degrees on the right. The light distribution ratio (luminous flux ratio) for each of the areas, i.e., the converged area, the intermediate area and the diverged area is set preferably at 1:2:4. As shown in FIG. 18, the set of lighting units 41 can include a plurality (in the case shown, four (4)) of light source modules 42a, 42b, 42c and 42d, and projector lenses 43a, 43b, 43c and 43d, respectively, corresponding to the light source modules. Each of the light source modules 42a, 42b, 42c and 42d are preferably composed to be almost the same as the light source modules of the set of lighting units 11 of the vehicle lamp 10. Each of the projector lenses 43a, 43b, 43c and 43d can have the same composition as that shown in FIG. 4 and can each have a focusing position that is different from the other lenses, and can each have a focusing distance different from the other lenses. A luminous intensity and a projection size on a screen can be obtained by properly selecting the focusing distance of each of the projector lenses 43a, 43b, 43c and 43d. As shown in FIG. 19, the set of lighting units 51 can include a plurality (in the case shown, two (2)) of light source modules 52a and 52b, and reflectors 53a and 53b corresponding to the light source modules 52a and 52b. Each of the light source modules 52a and 52b can be configured to be similar to the light source module 22 in the set of lighting units 21 of the vehicle lamp 10, and can be arranged back-to-back in the direction from right to left. Here, an illuminating unit of each of the light source modules 52a and 52b can have one (1) or more linear ridge lines, for example, ridge lines formed as a rectangle, and the ridge line(s) can be longer than a filament of a halogen lamp or an arc electrode dimension and preferably have a length that is twice as long as the filament. As shown in FIG. 11, by using a light source package formed with a plurality of LED chips of a so-called multi-chip type arranged linearly in a package, the luminous flux of the light source package itself can be increased and the, size of the vehicle lamp can be minimized. Furthermore, each of the reflectors 53a and 53b can be composed similar to the reflector 23 in the set of lighting units 21 of the vehicle lamp 10 and can be configured to spread light in the rightward and leftward directions. Thus, even when the illuminating units of respective light source modules 52a and 52b have a relatively long linear ridge line, the position of the projected image of the illuminating units can be arbitrarily controlled based on the shape of reflectors 53a and 53b, and 70% or more of the luminous flux from the illuminating units can be emitted frontward. As shown in FIG. 20, the set of lighting units 61 can include a plurality (in the case shown, three (3)) of light source modules 62a, 62b and 62c, reflectors 63a 63b and 63c respectively corresponding to the light source modules, one (1) projector lens 64 and a shading member 65. Each of the light source modules 62a, 62b and 62c can be respectively composed similar to the light source module 32 as shown in the set of lighting units 31 of the-vehicle lamp 10, and can be arranged around the central axis and spaced from each other by the same degree. An illuminating unit of each of the light source modules 62a, 62b and 62c is preferably selected to be as small as possible, for example, smaller than the filament of a conventional halogen lamp or the arc electrode dimension of an MID. Each of the reflectors 63a, 63b and 63c can be configured similar to the reflector 33a in the set of lighting units 31 of the vehicle lamp 10, and can be arranged above and on both sides of the optical axis corresponding to each of the light source modules 62a, 62b and 62c. Furthermore, the projector lens 64 can be similar to the projector lens 33b in the set of lighting units 31 of the vehicle lamp 10, and preferably only one projector lens 64 is arranged on the optical axis. The shading member 65 can also be configured similar to the shading member 33c of the set of lighting units 31 of the vehicle lamp 10, and can be arranged in the vicinity of a focusing position on the light source side of the projector lens 64. In the case where the light source module has a linear illuminating unit, in order to form a light distribution pattern that spreads in the rightward and leftward directions, it is desirable that the light source module correspond to a reflector positioned above the optical axis and be arranged such that the longitudinal direction of the illuminating unit is substantially perpendicular to the optical axis. Furthermore, it is desirable that the light source module that corresponds to a reflector positioned on the side of the optical axis be arranged such that the longitudinal direction of the illuminating unit is parallel to the optical axis. Thereby, the projected image of the illuminating unit that is formed by the reflector extends horizontally and, therefore, a light distribution pattern can be easily formed. With respect to the vehicle lamp 40, as shown in FIG. 21, the set of lighting units 41 emits light to a converged area “La” and, as shown in FIG. 22, the set of lighting units 51 emits light to a diverged area “Lb,” and the set of lighting units 61 emits light to an intermediate area “Lc” between the converged area and the diverged area, as shown in FIG. 23. Then, by overlapping the light distribution patterns “La”, “Lb”, and “Lc” formed by each set of the lighting units 41, 51 and 61, as shown in FIG. 24, a light distribution pattern L suitable for a low beam can be formed. In the embodiments described above, the vehicle lamps 10 and 40 have lighting units 11, 21 and 31 or 41, 51 and 61, respectively, corresponding to the converged area, the diverged area and the intermediate area, respectively. However, the composition of a vehicle lamp is not limited to the above described preferred embodiments. For example, the lighting units 31 and 61 corresponding to the intermediate areas can be omitted. Furthermore, by adding a lighting unit that has a light distribution pattern for realizing a different function, for example, a daytime running lamp, a sub-lamp for a cornering lamp, a sub-headlight of a fog lamp or a so-called AFS lamp it is possible to form a multi-functional light distribution pattern with one (1) vehicle lamp. The light distribution pattern can also be divided into multiple areas and new lighting units can be added for the additional divided areas to form a multi-functional light distribution pattern with one (1) vehicle lamp. It is also possible to arbitrarily and/or optionally add or remove the lighting units by configuring the lighting units such that they are removable. The embodiments described above disclose a light distribution characteristic for a low beam limited to the case of running the vehicle on the left side of a road. Moreover, in order to avoid the production of dazzling or blinding light directed towards oncoming cars on the right side of a car, edges of the shading boards 12e, 33c and 65 are provided. However, the invention is not limited to this light distribution characteristic for a low beam. Specifically, in the case of running the vehicle on the right side of a road, the arrangement of the edges of the shading boards can be inverted to provide the same effect as described above with respect to the vehicle driven on the left hand side of the road, ie., diminishing the glaring, blinding or dazzling light that would be directed towards oncoming cars or pedestrians. While illustrative and presently preferred embodiments of the present invention have been described in detail herein, it is to be understood that the inventive concepts may be incorporated in different variations and embodiments and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art. | <SOH> SUMMARY OF THE INVENTION <EOH>In view of the foregoing, an aspect of the present invention includes a lamp or vehicle lamp suitable for a headlight, a sub-headlight, tail light, or other vehicle lamp, etc. configured to obtain a desired light distribution pattern using a plurality of LED devices as light sources. According to another aspect of the present invention there is provided a vehicle lamp that can include a plurality of light source modules each having an LED as a light source; and-optical systems for emitting light from each of the light source modules frontward toward predetermined areas of a light distribution pattern, the predetermined areas being different from each other, wherein each of the optical systems can be optimized to emit the light to a predetermined area, and wherein the LEDs of the light source modules can be arranged optimally for the optical systems corresponding thereto. Preferably, each of the light source modules and each of the optical systems respectively emit light to a converged area and a diverged area of the light distribution pattern. In addition, it is preferable that each of the light source modules and each of the optical systems respectively emit light to a converged area, a diverged area and an intermediate area of the light distribution pattern. Preferably, the light source module for emitting light to the converged area of the light distribution pattern includes a shading member having a shape similar to that of the light distribution pattern of a low beam, and the optical system corresponding thereto can be composed of a projector lens for converging light. The light source module for emitting light to the diverged area of the light distribution pattern preferably has a shape for illumination having one linear ridge line and is elongated in one direction, and the optical system corresponding thereto preferably includes a reflector for condensing light from the light source module by reflecting the light. The optical system for emitting light to the intermediate area of the light distribution pattern is preferably composed of a reflector and a projector lens such that the light distribution characteristics of the converged area and the diverged area are smoothly connected to each other. The light source module and the optical system can be optimized for emitting light to a light distribution area of a sub-lamp. The light distribution area of the sub-lamp can be a light distribution area of a daytime running lamp, a fog lamp, a cornering lamp, etc. The light source module and the optical system can be arranged in a removable fashion and optimized for emitting light to an arbitrary or even light distribution area Each of the respective light source modules can be configured as a different kind of package as compared to each other, for which the number of LEDs, the arrangement and the composition can be optimized for the light distribution area for each respective light source module in order to efficiently emit light. According to the above structure, a light distribution pattern can be divided into a plurality of areas, and a light source module and an optical system can be provided for each of the areas. Then, by optimizing each of the light source modules and each of the optical system for their corresponding area respectively, a light distribution characteristic can be obtained in which each of the areas of the light distribution pattern respectively has desired luminous intensity distribution. Thereby, the vehicle lamp as a whole can form a desired light distribution pattern having desired luminous intensity distribution by virtue of the plurality of combinations of the light source modules and the optical systems. In this case, by optimizing each of the LEDs of each of the light source modules together with the optical system for their corresponding area of the light distribution pattern, the efficiency of light usage from each of the LEDs can be increased and brighter emitted light can be obtained. When each of the above light source modules and optical systems emit light respectively to the converged area and the diverged area of the light distribution pattern, they can respectively emit light to the converged area and the diverged area in desired light distribution by optimizing each of the light source modules and each of the optical systems respectively for the converged area and the diverged area of the light distribution pattern. Thereby, as a whole, a light distribution pattern having desired luminous intensity distribution can be formed. When each of the above light source modules and optical systems emit light respectively to the converged area, the diverged area and an intermediate area of the light distribution pattern, they can respectively emit light to the converged area, the diverged area and the intermediate area in desired luminous intensity distribution by optimizing each of the light source modules and each of the optical systems respectively for the converged area, the diverged area and the intermediate area of the light distribution pattern. Thereby, as a whole, a light distribution pattern having desired luminous intensity distribution can be formed and, at the same time, the converged area and the diverged area can be continuously connected by the intermediate area in a smoothly varying contrast. In the case where a light source module for emitting light to the converged area of the above light distribution pattern is provided with a shading member having the same shape as that of the light distribution pattern of the low beam, and an optical system corresponding to the module includes a projector lens for converging light, a cut-off can be formed by a shading member. The shading member can be located to block light from each LED of the light source module and, further, the shape of the emission formed by the cut-off can be converged by the projector lens and emitted frontward. Thereby, in a simple structure, it is possible to, for example, form a border of light and shade having a high contrast in the vicinity of the center. Therefore, it is possible to form a light distribution pattern suitable for the converged area. In the case where a light source module for emitting light to a diverged area of the above light distribution pattern has an illuminating shape having one linear ridge line and is elongated along one direction, and an optical system corresponding to the light source module includes a reflector for reflecting light from the light source module, utilizing, for example, a light source module in which LED chips are arranged in a line, the linear ridge line is reflected by the reflector and emitted frontward. Therefore, the light from the light source module can be efficiently reflected frontward. At the same time, a high-contrast border of light and shade can be formed by projecting the linear ridge line into the vicinity of a cut-off line. Thereby, it is possible to form a light distribution pattern diverging in the horizontal direction (the cut-off line has a difference in light and shade) and suitable for the diverged area. Furthermore, since the light source module is substantially plane-illuminating and fully-diverging illuminating, the reflector does not need to cover the entire light source and can have a substantially planar shape. Therefore, the vehicle lamp can be made thin. In the case where an optical system for emitting light to the intermediate area of the above light distribution pattern includes a reflector and a projector lens such that the light distribution characteristics of the converged area and the diverged area are connected continuously and smoothly, the light is diverged by the reflector and is converged by the projector lens and emitted frontward while being slightly diverged. Since the cut-off is formed by a shading board at a lens focus, it is possible to smoothly connect a light distribution pattern forming a high-contrast border of light and shade in the converged area with a light distribution pattern diverging horizontally in the diverged area. Furthermore, in the case where a light source module and an optical system optimized for emitting light to a light distribution area of a sub-lamp are provided and, preferably, the light distribution area of the sub-lamp is a daytime-running lamp distribution area, fog lamp distribution area or a cornering lamp distribution area, the light source module and the optical system can be directly incorporated in the vehicle lamp. Therefore, it is possible to implement a function of a sub-lamp in the vehicle lamp itself, and the entire lamp fitting for a vehicle can be made very small. As a result, the degree of freedom for lamp design and lamp fitting for a vehicle is increased. Furthermore, in the case where a light source module and an optical system optimized for emitting light to an arbitrary light distribution area are removably arranged, it is possible to add or remove functions of a sub-lamp or other lamp fittings for a vehicle as necessary. Therefore, it is possible to easily manufacture a lamp fitting for a vehicle provided with arbitrary functions. As indicated, each light source module can be structured as a different kind of package for which the number, the arrangement and the structure of LED chips are optimized, respectively, corresponding to a light distribution area in order to efficiently emit light. Therefore, a vehicle lamp can be made by combining different types of such packages. In this manner, by virtue of a light source module employing an LED as a light source, light from each of the LEDs can be emitted to a predetermined area in a light distribution pattern through the corresponding optical system. In this case, since the light source module and the optical system are optimized in terms of each corresponding area of the light distribution pattern, it is possible to realize a light distribution characteristic having a desired shape of illumination and intensity distribution. Therefore, even when an LED, which typically has a lower intensity compared to an electric discharge lamp such as a halogen lamp or an HID lamp, is used as a light source, a sufficient maximum luminous intensity can be obtained. Therefore, it is possible to realize a highly efficient, small and thin vehicle lamp. Furthermore, since a desired light distribution characteristic can be formed by combining light source modules, the degree of freedom of light distribution and the degree of freedom of the design of the vehicle lamp can be increased. Another aspect of the invention includes a vehicle lamp that has: a first light source module having an LED as a light source; a first optical system located adjacent the first light source module; a second light source module having an LED as a light source; a second optical system located adjacent the second light source module, wherein the first light source module and corresponding first optical system are configured to emit light in a first pattern, and the second light source module and corresponding second optical system are configured to emit light in a second pattern that is different from the first pattern. The vehicle lamp can also include a first pattern that is not symmetrical and is elbow shaped. In addition, a third light source module can be provided an LED as a light source; and a third optical system can be located adjacent the third light source module, wherein the third light source module and corresponding third optical system are configured to emit light in a third pattern, and the third pattern being different from the first pattern and the second pattern. | 20040217 | 20060613 | 20050428 | 63977.0 | 0 | CRANSON JR, JAMES W | VEHICLE LAMP | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,778,775 | ACCEPTED | Light shield mounting for automotive headlamp | A lamp unit has a reflector (10) having a reflector surface (12) with an inverted U-shaped aperture (14) formed therein and extending through said reflector to an opposite surface (16). The inverted U-shaped aperture thereby has a bight (18) uppermost with a pair of channels (20, 22) depending therefrom. A light-shield (24) comprises a cup-shaped member (26) having an arm (28) projecting therefrom. The arm (28) has a distal end (30) formed to provide a pair of nibs (32, 34) for engaging and penetrating the channels (20, 22) of the inverted U-shaped aperture (14). The nibs (32, 34) have their ends (36, 38) deformed to fix the position of the light-shield (24) relative to the reflector (10). | 1. A lamp unit comprising: a reflector having a reflector surface with an inverted U-shaped aperture formed therein and extending through said reflector to an opposite surface, said inverted U-shaped aperture thereby having the bight uppermost with a pair of channels depending therefrom; and a light-shield comprising a cup-shaped member having an arm projecting therefrom, said arm having a distal end formed to provide a pair of nibs for engaging and penetrating said channels of said inverted U-shaped aperture and having their ends deformed to fix the position of said light-shield relative to said reflector. 2. The lamp unit of claim 1 wherein said nibs have their ends deformed outwardly. 3. The lamp unit of claim 1 wherein said nibs have their ends deformed inwardly. 4. The lamp unit of claim 1 wherein said inverted U-shaped aperture has an entrance side and an exit side and said entrance side is provided with a stop that cooperates with mating stop edges formed in said nibs and determines the degree of penetration of said nibs into said channels of said inverted U-shaped aperture. 5. The lamp unit of claim 1 wherein said nibs have a transverse bar connecting them for part of their length and said transverse bar is provided with a tensioning spring. | TECHNICAL FIELD This invention relates to lamp units and more particularly to automotive headlamps. Still more particularly it relates to a reflector and shield for an automotive headlamp unit. BACKGROUND ART Automotive headlamps employ small light sources arranged in a reflector. It is common practice to cover the forwardmost facing part of the light source with a cup-shaped shield. Mounting the shield is a continuing problem usually solved by having an arm on the shield having a distal end that is fixed to the reflector at a remote location, usually by a screw or by a pressed-in fit. Use of the screw introduces an extra part raising the cost while the pressed-in feature allows the shield to fall out if it is not properly engaged. DISCLOSURE OF INVENTION It is, therefore, an object of the invention to obviate the disadvantages of the prior art. It is another object of the invention to enhance light shields in automotive headlamps. These objects are accomplished, in one aspect of the invention, by the provision of a lamp unit comprising: a reflector having a reflector surface with an inverted U-shaped aperture formed therein and extending through said reflector to an opposite surface, said inverted U-shaped aperture thereby having the bight uppermost with a pair of channels depending therefrom; and a light-shield comprising a cup-shaped member having an arm projecting therefrom, said arm having a distal end formed to provide a pair of nibs for engaging and penetrating said channels of said inverted U-shaped aperture and having their ends deformed to fix the position of said light-shield relative to said reflector. Deforming the nibs provides more than adequate fixation for the shield and eliminates the need for a screw or other separate holding device or dependence upon a mere friction fit. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a shield in accordance with an aspect of the invention; FIG. 2 is a perspective view of a shield first mounted to a reflector; FIG. 3 is a perspective view of the front or reflector surface side of an aperture formed in the reflector; FIG. 4 is a perspective view of the rear surface of the aperture formed in the reflector; FIG. 5 is a perspective view of a first embodiment of deformation of the shield fixing means; FIGS. 6 and 7 are diagrammatic perspective views of the sequence of operation for accomplishing the deformation of the first embodiment; FIG. 8 is perspective view of a second embodiment of the deformation of the shield fixing means; FIG. 9 is a diagrammatic plan view of the sequence of operation for accomplishing the deformation of the second embodiment; and FIG. 10 is a perspective view, partially in section, of a spring element used for positioning the shield. BEST MODE FOR CARRYING OUT THE INVENTION For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in conjunction with the above-described drawings. Referring now to the drawings with greater particularity, there is shown in FIG. 1 a light-shield 24 having a cup-shaped member 26 with an arm 28 projecting therefrom. The arm 28 has a distal end 30 formed to provide nibs 32, 34 having ends 36, 38. A reflector 10 (see particularly FIGS. 2, 3, and 4) has a reflector surface 12 with an inverted U-shaped aperture 14 formed therein and extending through the reflector to an opposite surface 16. To provide an adequate length for nibs 32, 34, a housing 17 is formed with surface 16. The inverted U-shaped aperture 14 has a bight 18 uppermost and channels 20, 22 depending therefrom to receive the nibs 32, 34, as shown in FIG. 2. Aperture 14 has an entrance side 12a and an exit side 16a and the entrance side 12a is provided with a stop 40 that limits the penetration of nibs 32 and 34 into the aperture 14. The stop 40 cooperates with mating stop edges 42, 43 formed on nibs 32, 34. A transverse web 44 connects the nibs 32, 34 for a part of their length and is provided with a tensioning spring member 46. As shown in FIG. 10, when the nibs 32, 34 are inserted into the channels 20, 22, the tensioning spring 46 exerts pressure against the bight 18 and the rib 48 formed between the channels 20, 22, thereby accurately positioning the light-shield 24 with respect to the reflector 10. With light-shield 24 held in position by the tension between the spring member 46 and the bight 18 and the fit of the nibs 32, 34 in channels 20, 22, the ends 36, 38 of the nibs 32, 34 are deformed by compressing them inwardly toward the rib 48 as shown in FIGS. 5 and 6, or by deforming the nibs outwardly, away from the rib 48 as shown in FIG. 8. FIGS. 6 and 7 illustrate the inward deformation performed by tools 60a and 60b while FIG. 9 illustrates the outward deformation performed by a tool 62. In a preferred embodiment of the invention, the reflector material is unsaturated polyester and the light-shield material is 1008-1010 C.R.S. This structure greatly enhances the operation of lamp units. The cooperation between the stop 40 and the stop-edge 42, 43, the fit between the nibs 32, 34 and the channels 20, 22, and the tension provided by the spring member 46 guaranty a proper initial location for the light-shield and the deformation of the ends of the nibs 32, 34 assures that the initial location remains. While there have been shown and described what are at present considered to be the preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims. | <SOH> BACKGROUND ART <EOH>Automotive headlamps employ small light sources arranged in a reflector. It is common practice to cover the forwardmost facing part of the light source with a cup-shaped shield. Mounting the shield is a continuing problem usually solved by having an arm on the shield having a distal end that is fixed to the reflector at a remote location, usually by a screw or by a pressed-in fit. Use of the screw introduces an extra part raising the cost while the pressed-in feature allows the shield to fall out if it is not properly engaged. | <SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 is a perspective view of a shield in accordance with an aspect of the invention; FIG. 2 is a perspective view of a shield first mounted to a reflector; FIG. 3 is a perspective view of the front or reflector surface side of an aperture formed in the reflector; FIG. 4 is a perspective view of the rear surface of the aperture formed in the reflector; FIG. 5 is a perspective view of a first embodiment of deformation of the shield fixing means; FIGS. 6 and 7 are diagrammatic perspective views of the sequence of operation for accomplishing the deformation of the first embodiment; FIG. 8 is perspective view of a second embodiment of the deformation of the shield fixing means; FIG. 9 is a diagrammatic plan view of the sequence of operation for accomplishing the deformation of the second embodiment; and FIG. 10 is a perspective view, partially in section, of a spring element used for positioning the shield. detailed-description description="Detailed Description" end="lead"? | 20040213 | 20060314 | 20050818 | 85716.0 | 0 | LE, KHANH H | LIGHT SHIELD MOUNTING FOR AUTOMOTIVE HEADLAMP | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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10,778,857 | ACCEPTED | Multicasting in a shared address space | There is disclosed apparatus and methods of multicasting in a shared address space. There may be defined a number of portions of the address space. There may be groups of the portions, and data units addressed to one portion within the group may be re-addressed to the other portions | 1. A method of multicasting data units having destination addresses in a shared address space, the switch having a plurality of ports, wherein respective individual portions of the address space are associated with each of the ports, respective multicast portions are associated with at least some of the ports, and wherein the multicast portions have associations with one other, the method comprising, for a given data unit if the destination address is in the individual portion associated with one of the ports, then forwarding the data unit for transmission out the associated port if the destination address is in the multicast portion associated with one of the ports, then forwarding the data unit for transmission out the port associated with the multicast portion encompassing the destination address forwarding the data unit for transmission out the ports associated with multicast portions associated with the multicast port encompassing the destination address, wherein the forwarded data unit is revised to specify a destination address within the respective multicast address. 2. The method of multicasting in a shared address space of claim 1 wherein the individual portions are unique within the shared address space with respect to one another. 3. The method of multicasting in a shared address space of claim 1 wherein the multicast portions are unique within the shared address space with respect to one another. 4. A switch for multicasting in a shared address space, the switch comprising a buffer for storing data units, the data units having a destination address a first port having a first address portion in the shared address space a second port having a second address portion in the shared address space logic to cause data units in the buffer having a destination address in the first address portion to be forwarded for transmission out the first port without being removed from the buffer and then replace the destination address with an address in the second address portion cause data units in the buffer having a destination address in the second portion to be forwarded for transmission out the second port. 5. The switch for multicasting in a shared address space of claim 4 wherein the first address portion has a first size the second address portion has a second size the second size is substantially equal to the first size. 6. The switch for multicasting in a shared address space of claim 5 wherein the second size is exactly equal to the first size. 7. The switch for multicasting in a shared address space of claim 4 wherein the first address portion has a first base address the second address portion has a second base address the first base address and the second base address differ by only a single digit. 8. The switch for multicasting in a shared address space of claim 4, wherein the shared address space comprises a shared memory address space, and the switch has logic to transmit data units through the first port and the second port via memory mapped I/O into the shared address space. 9. The switch for multicasting in a shared address space of claim 4 having at least three ports, wherein the logic supports all of the ports having the characteristics defined for the first port. 10. The switch for multicasting in a shared address space of claim 4 wherein the logic is further to cause data units in the buffer having a destination address in the second portion to be forwarded for transmission out the second port and be removed from the buffer. 11. The switch for multicasting in a shared address space of claim 4 wherein the first port has a third address portion in the shared address space wherein the second port has a fourth address portion in the shared address space wherein the logic is further to cause data units in the buffer having a destination address in the third address portion to be forwarded for transmission out the first port and be removed from the buffer cause data units in the buffer having a destination address in the fourth portion to be forwarded for transmission out the second port and be removed from the buffer. 12. The switch for multicasting in a shared address space of claim 4 wherein the first portion comprises only a portion of a pre-existing address portion in the shared address space assigned to the first port. 13. A switch for multicasting in a shared address space, the switch comprising a buffer logic to store data units into the buffer a first port having a first address portion in the shared address space, the first address portion including an individual portion and a multicast portion a second port having a second address portion in the shared address space including an individual portion and a multicast portion logic to cause data units in the buffer having a destination address in the individual portion of the first address portion to be forwarded for transmission out the first port and be removed from the buffer cause data units in the buffer having a destination address in the individual portion of the second portion to be forwarded for transmission out the second port and be removed from the buffer cause data units in the buffer having a destination address in the multicast portion of the first address portion to be forwarded for transmission out the first port without being removed from the buffer and then replace the destination address with an address in the multicast portion of the second address portion cause data units in the buffer having a destination address in the multicast portion of the second portion to be forwarded for transmission out the second port. 14. The switch for multicasting in a shared address space of claim 13 further comprising a third port having a third address portion in the shared address space including an individual portion and a multicast portion logic to cause data units in the buffer having a destination address in the individual portion of the third address portion to be forwarded for transmission out the third port and be removed from the buffer replace the destination address of data units in the buffer having a destination address in the multicast portion of the second address portion with an address in the multicast portion of the third address portion cause data units in the buffer having a destination address in the multicast portion of the third portion to be forwarded for transmission out the third port. 15. The switch for multicasting in a shared address space of claim 13 wherein the multicast portion of the first address portion has a first size the multicast portion of the second address portion has a second size the second size is substantially equal to the first size. 16. The switch for multicasting in a shared address space of claim 15 wherein the second size is exactly equal to the first size. 17. The switch for multicasting in a shared address space of claim 13 wherein the multicast portion of the first address portion has a first base address the multicast portion of the second address portion has a second base address the first base address and the second base address differ by only a single digit. 18. The switch for multicasting in a shared address space of claim 13, wherein the shared address space comprises a shared memory address space, and the switch has logic to transmit data units through the first port and the second port via memory mapped I/O into the shared address space. 19. The switch for multicasting in a shared address space of claim 13 having at least three ports, wherein the logic supports all of the ports having the characteristics defined for the first port. 20. The switch for multicasting in a shared address space of claim 13 wherein the logic is further to cause data units in the buffer having a destination address in the multicast portion of the second address portion to be forwarded for transmission out the second port and be removed from the buffer. 21. The switch for multicasting in a shared address space of claim 13, wherein the first address portion includes a broadcast portion, and the second address portion includes a broadcast portion, the switch further comprising a third port having a third address portion in the shared address space including an individual portion, a multicast portion and a broadcast portion logic to cause data units in the buffer having a destination address in the individual portion of the third address portion to be forwarded for transmission out the third port and be removed from the buffer cause data units in the buffer having a destination address in the broadcast portion of the first address portion, the second address portion or the third address portion to be forwarded for transmission out the first port, the second port and the third port with the destination address set to an address in the broadcast portion of the respective address portion for the respective port. 22. A method of multicasting in a shared address space, the switch having a buffer, a first port and a second port, the method comprising associating a first address portion in the shared address space with the first port, the first address portion including an individual portion and a multicast portion associating a second address portion in the shared address space with the second port, the second address portion including an individual portion and a multicast portion storing data units in the buffer, the data units including a destination address in the shared address space if a data unit in the buffer has a destination address in the individual portion of the first address portion, then forwarding the data unit for transmission out the first port removing the data unit from the buffer if a data unit in the buffer has a destination address in the multicast portion of the first address portion, then forwarding the data unit for transmission out the first port replacing the destination address of the data unit with an address in the multicast portion of the second address portion forwarding the data unit for transmission out the second port removing the data unit from the buffer if a data unit in the buffer has a destination address in the individual portion of the second address portion, then forwarding the data unit for transmission out the second port removing the data unit from the buffer. 23. The method of multicasting in a shared address space of claim 22 wherein the shared address space comprises a shared memory address space, the method further comprising transmitting data units through the first port via memory mapped I/O into the shared memory address space transmitting data units through the second port via memory mapped I/O into the shared memory address space. 24. The method of multicasting in a shared address space of claim 22 wherein the multicast portion of the first address portion has a first size the multicast portion of the second address portion has a second size the second size is substantially equal to the first size. 25. The method of multicasting in a shared address space of claim 0 wherein the second size is exactly equal to the first size. 26. The method of multicasting in a shared address space of claim 22, wherein there is a third port, the method further comprising providing characteristics defined for the first port for the second port and the third port. 27. The method of multicasting in a shared address space of claim 22 further comprising, if a data unit in the buffer has a destination address in the individual portion of the second address portion, then forwarding the data unit for transmission out the second port removing the data unit from the buffer. 28. The method of multicasting in a shared address space of claim 22, wherein the first address portion includes a broadcast portion and the second address portion includes a broadcast portion, the method further comprising associating a third address portion in the shared address space with a third port, the third address portion including an individual portion, a multicast portion and a broadcast portion if a data unit in the buffer has a destination address in the individual portion of the third address portion, then forwarding the data unit for transmission out the third port removing the data unit from the buffer if a data unit in the buffer has a destination address in the broadcast portion of the first address portion, the second address portion or the third address portion, then forwarding the data unit for transmission out the first port, the second port and the third port with the destination address set to an address in the broadcast portion of the respective address portion for the respective port removing the data unit from the buffer. | RELATED APPLICATION INFORMATION This patent is a continuation-in-part of Application No. 60/534,586 filed Jan. 5, 2004 and entitled “PCI Express Switch with Broadcast and/or Multicast Capability.” NOTICE OF COPYRIGHTS AND TRADE DRESS A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by any one of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to multicasting in a shared address space. 2. Description of the Related Art The Peripheral Component Interconnect (“PCI”) standard was promulgated about ten years ago, and has since been updated a number of times. One update led to the PCI/X standard, and another, more recently, to PCI Express. The PCI standards are defined for chip-level interconnects, adapter cards and device drivers. The PCI standards are considered cost-effective, backwards compatible, scalable and forward-thinking. PCI buses, whether they be PCI Express or previous PCI generations, provide an electrical, physical and logical interconnection for multiple peripheral components of microprocessor based systems. PCI Express systems differ substantially from their PCI and PCI/X predecessors in that all communication in the system is performed point-to-point. Unlike PCI/X systems in which two or more end points share the same electrical interface, PCI Express buses connect a maximum of two end points, one on each end of the bus. If a PCI Express bus must communicate with more than one end point, a switch, also known as a fan out device, is required to convert the single PCI Express source to multiple sources. The communication protocol in a PCI Express system is identical to legacy PCI/X systems from the host software perspective. In all PCI systems, each end point is assigned one or more memory and 10 address ranges. Each end point is also assigned a bus/device/function number to uniquely identify it from other end points in the system. With these parameters set a system host can communicate with all end points in the system. In fact, all end points can communicate with all other end points within a system. However, communication in PCI Express is limited to two end points, a source and a destination, at a time. The PCI Express standard specifies one limited form of broadcasting. That is, if the transaction is a TLP type Message (Msg) denoted by a Format and Type field of 0110011, the transaction is broadcast from the Root Complex to all end points. This broadcast is for system management and configuration and is not applicable to data transport transactions. DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a switching environment. FIG. 2 is a diagram of a shared address space. FIG. 3 is a flow chart of a method of multicasting in a shared address space. DETAILED DESCRIPTION OF THE INVENTION Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and methods of the present invention. Description of Systems Referring now to FIG. 1, there is shown a block diagram of a switching environment 100. The switching environment includes a switch 110, a number of end points 120a, 120b, 120c, 120d. The switching environment 100 may be a point-to-point communications network. The term “switch” as used herein means a system element that connects two or more ports to allow data units to be routed from one port to another, and the switch 110 is a switch. The switch 110 includes a number of ports 112a, 112b, 112c, 112d, which are logical interfaces between the switch 110 and the end points 120. The switch 110 further includes a buffer 115 and logic 117. By data unit, it is meant a frame, cell, datagram, packet or other unit of information. In some embodiments, such as PCI, a data unit is unencapsulated. Data units may be stored in the buffer 115. By buffer, it is meant a dedicated or shared memory, a group or pipeline of registers, and/or other storage device or group of storage devices which can store data temporarily. The buffer 115 may operate at a speed commensurate with the communication speed of the switching environment 100. For example, it may be desirable to provide a dedicated memory for individual portions (as described below) and pipelined registers for multicast portions (as described below). The logic 117 includes software and/or hardware for providing functionality and features described herein. The logic 117 may include one or more of: logic arrays, memories, analog circuits, digital circuits, software, firmware, and processors such as microprocessors, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), programmable logic devices (PLDs) and programmable logic arrays (PLAs). The hardware and firmware components of the logic 117 may include various specialized units, circuits, software and interfaces for providing the functionality and features described herein. The invention may be embodied in whole or in part in software which operates in the switch 110 and may be in the form of firmware, an application program, an applet (e.g., a Java applet), a browser plug-in, a COM object, a dynamic linked library (DLL), a script, one or more subroutines, or an operating system component or service. The hardware and software of the invention and its functions may be distributed such that some components are performed by the switch 110 and others by other devices. The end points 120a, 120b, 120c, 120d are logical devices which connect to and communicate with the switch 110 respectively through the ports 112. The end points 120a, 120b, 120c, 120d may share an address space, such as a memory address space or an I/O address space. The term “address space” means the total range of addressable locations. If the shared address space is a memory address space, then data units are transmitted via memory mapped I/O to a destination address into the shared memory address space. Referring now to FIG. 2, there is shown a diagram of a shared address space 200. The shared address space 200 shows contiguous ranges, but the address spaces associated with the end points 120 may be non-contiguous and the term “portions” is meant to refer to contiguous and non-contiguous spaces. Data units may be written into or communicated into an address portion. Address portions must therefore be large enough to accommodate at least one data unit. For at least these reasons, a single point or address within an address space cannot be a portion. An address portion must occupy at least two slots within the address space, and in most embodiments will have a sizable number of slots specified as a range. In a switch conforming to the PCI Express standard, it is expected that the address portions in a 32-bit shared memory address space or shared I/O address space will be at least as large as the largest expected transaction, and comparable to those shown in FIG. 2. Within the shared address space 200, there is a gross address portion 210a associated with end point A 120a. Within the gross address portion 210a, there is an individual portion 220a, a multicast portion 230a and a broadcast portion 240a. Likewise, end point B 120b may have a gross address portion 210b with an individual portion 220b, a multicast portion 230b and a broadcast portion 240b. Likewise, end point C 120c may have a gross address portion 210c with an individual portion 220c, a multicast portion 230c and a broadcast portion 240c. A gross address portion, an individual portion, a multicast portion and a broadcast portion may be associated with end point D 120d. The address space 200 may be allocated so as to provide the end points 120 with unique gross address portions. The individual portions may be unique within the shared address space with respect to one another, as may be the multicast portions and the broadcast portions. The address portions (gross, individual, multicast and broadcast) may have various characteristics. The address portions may have respective sizes. The sizes may be fixed or variable. The address portions may be defined by a base address, as well as by a size or end address. The address portions may come to be associated with the end points 120 through an arbitrage process, through centralized assignment (e.g., by a host or the switch 110), otherwise or through a combination of these. The group portion, the individual portion, the multicast portion and the broadcast portion for a given end point 120 need not be contiguous. To avoid errors, it may be desirable if the individual portions, the multicast portions and the broadcast portions do not overlap. Data units may be directed to one or more of the end points 120 by addressing. That is, a destination address is associated with and may be included in the data units. The destination address determines which end point 120 should receive a given data unit. Thus, data units addressed to the individual portion for a given end point 120 should be received only by that end point 120. Depending on the embodiment, the destination address may be the same as the base address or may be within the address portion. Multicasting presents a somewhat more complex and flexible case than single-casting. To allow for multicasting to a group of selected end points, a multicast group is defined. Within the multicast group, the multicast portions of the selected end points are associated, and logic is provided which causes data units sent to the multicast portion of one end point in the multicast group to be sent to the multicast portions of the other end points in the multicast group. The data units addressed to the multicast portion for a given end point 120 should be received by all of the end points in the same multicast group. Alternatively, within a multicast group, one of the multicast portions may be selected as a “master” and the other multicast portions treated as ghosts. Accordingly, data units addressed to the master may be multicast to the group, but data units addressed to a ghost may be single-cast to the slave or treated as exceptions. A given end point 120 may belong to multiple multicast groups and therefore have multiple multicast portions. For example, end point A 120a may be in a first multicast group with end point B 120b, in a second multicast group with end point C 120c, and a third multicast group with end point B 120b and end point C 120c. In this example, end point A might have three multicast portions. The various multicast groups may also be grouped, to provide super-groupings. For example, there might be a first multicast group having end point A 120a and end point B 120b; a second multicast group having end point A 120a and end point C 120c; and a third multicast group having the first multicast group and the second multicast group, i.e., end point A 120a, end point B 120b and end point C 120c. It can be seen that single-casting and broadcasting are special cases of multicasting. In single-casting, the multicast group includes only one end point, and has only the one end point's individual portion. In contrast, in broadcasting, the multicast group includes all end points, and has the broadcast portions for all end points. In one alternative, there is a single broadcast portion, and logic is provided which causes data units which are sent to the broadcast portion to be sent to the individual portions of all end points 120. Each multicast portion may be unique. Alternatively, there may be a single multicast portion for all of the end points 120 in a multicast group. An alternate way to support multicast would be to define multiple sub-portions within a master broadcast portion, each with its own vector defining which ports are to participate in the multicast transactions. Each sub-portion would define a multicast group and the associated vector would contain an enable bit for each port on the switch. If the enable bit for a port is set then the transaction is forwarded to that port. Any number of multicast portions could be defined by this mechanism. The multicasting portions in a group may have nearly identical base addresses, and only differ from each other from a single or small number of bits or digits. The sizes of the individual portions for the various end points 120 may differ. In contrast, the multicasting portions in a multicast group may have substantially equal or equal sizes. Having such equal-sized multicast portions may ensure communication integrity and efficient use of the shared address space 300. The end points 120 may be associated with respective ports 112. Through this association, a given end point 120 may send data units to and receive data units from its associated port 112. This association may be on a one-to-one basis. Because of these relationships, the ports 112 also have associations with the address portions of the end points 120. Thus, the ports 112 may be said to have address portions (including respective individual portions, multicast portions and broadcast portions) within the address space 200. Description of Methods Referring now to FIG. 3, there is shown a flow chart of a method of multicasting in a shared address space. The switch 110 may receive a data unit, e.g., through port D 120d (step 305). The logic 117 causes the received data unit to be stored in the buffer 115 (step 310). The data unit may be stored in whole or in part in the buffer 115. For example, in streaming applications, it may be desirable to store a header in the buffer but switch the payload directly from the ingress port to the egress port in a cut-through manner. The logic 117 also determines the destination address of the data unit and selects the port 120 associated with the destination address (step 315). Step 315 may be performed, for example, using a lookup table, or through hard wiring addresses to ports. Next, the logic 117 forwards the data unit for transmission out the selected port 120 (step 320). If the destination address is in the individual portion associated with one of the ports (step 325), then the logic 117 causes or allows the data unit to be removed from the buffer 115 (step 395). If the destination address is in the multicast portion associated with one of the ports (step 325), then step 395 is deferred. Instead, the data unit is forwarded for transmission out the other ports in the same group as the multicast portion encompassing the destination address. This may be achieved by replacing the destination address of the data unit with that of another (e.g., the next) multicast portion in the same group (step 330), and then forwarding the data unit for transmission out the port associated with the (revised) destination address (step 335). If there is more than one port in the multicast group (step 340), steps 330 and 335 may be continued until the data unit has been forwarded for transmission out all of the ports in the group. Then, the data unit may be removed from the buffer 115 (step 395). The replacing step 330 may be performed in a number of ways. For example, the destination address may be revised by drawing addresses from a table of multicast portions. Alternatively, the multicast portions in a multicast group may differ from one another according to a rule, and the rule used to determine the next destination address. For example, as shown in FIG. 2, the multicast portions may be contiguous blocks of 0x10000000 spaced apart by 0x40000000. Broadcasting may be handled similarly to multicasting. Thus, if a data unit has a destination address in the broadcast portion for a port, then the data unit is forwarded for transmission out the port, the destination address is revised as in step 330 and the data unit is forwarded as in step 335. This may be continued until the data unit has been forwarded for transmission out all of the ports. The use of shared memory space as described may be considered as providing “real” ports which are associated with the individual portions, and “virtual” ports which are associated with the multicast portions and broadcast portions. The virtual ports may be mapped to the real ports. Thus, data units may be multicast simply by selecting an appropriate address, and neither the format of the data units nor the content of the data units need be changed to accommodate multicasting. Intelligence in the switch recognizes that an address is a multicast address, and replicates and re-maps the address of the data units to the other ports in the multicast group. Although broadcast has been treated as a special case of multicast, the converse is also possible. According to one alternative, broadcast support is enabled and ports outside of the multicast group are disabled. This could be done ahead of each multicast data unit. For example, to send a data unit from end point D 120d to both end point A 120a and end point C 120c, end point D 110d could send an instruction to the switch 110 to enable broadcast, but disable port B 112b. End point D 120d would then send the data unit which the switch 110 would route to port A 112a and port C 112c. With regard to FIG. 2, additional and fewer steps may be taken, and the steps as shown may be combined or further refined to achieve the methods described herein. There may be anticipated and unanticipated conditions in which one or more of the ports 112 is removed or otherwise becomes unavailable, either in a controlled or uncontrolled manner. To maintain desirable data flow, the logic 117 may include a capability to resolve these types of port exceptions. If a port becomes unavailable, for example, the logic 117 may ignore or discard those data units addressed to the individual portion, the multicast portion and/or the broadcast portion for that port. If the data unit is addressed to a The logic 117 may multicast portion or a broadcast portion for an unavailable port, the logic may skip the unavailable port and continue the multicast or broadcast to other ports. Alternatively, the logic 117 may discontinue the multicast or broadcast altogether. The logic 117 may report the port exceptions and its response to the source of the data units and/or to other destinations. The invention may be used to advantage in PCI Express switches and devices. For example, PCI Express-compliant video graphics systems and communications data backplanes may benefit from the invention. It is believed that the invention is compatible with the PCI Express memory write request transaction. The invention may be compatible with other PCI Express transaction types and other standards. The PCI Express standard provides for confirmation messages in some situations, which the standard refers to as non-posted transactions. The system and methods described herein are compatible with both posted and non-posted transactions, though it may be desirable to consolidate or otherwise dispose of confirmation messages responsive to multicast and broadcast data units. Although exemplary embodiments of the present invention have been shown and described, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit of the present invention. All such changes, modifications and alterations should therefore be seen as within the scope of the present invention. | <SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to multicasting in a shared address space. 2. Description of the Related Art The Peripheral Component Interconnect (“PCI”) standard was promulgated about ten years ago, and has since been updated a number of times. One update led to the PCI/X standard, and another, more recently, to PCI Express. The PCI standards are defined for chip-level interconnects, adapter cards and device drivers. The PCI standards are considered cost-effective, backwards compatible, scalable and forward-thinking. PCI buses, whether they be PCI Express or previous PCI generations, provide an electrical, physical and logical interconnection for multiple peripheral components of microprocessor based systems. PCI Express systems differ substantially from their PCI and PCI/X predecessors in that all communication in the system is performed point-to-point. Unlike PCI/X systems in which two or more end points share the same electrical interface, PCI Express buses connect a maximum of two end points, one on each end of the bus. If a PCI Express bus must communicate with more than one end point, a switch, also known as a fan out device, is required to convert the single PCI Express source to multiple sources. The communication protocol in a PCI Express system is identical to legacy PCI/X systems from the host software perspective. In all PCI systems, each end point is assigned one or more memory and 10 address ranges. Each end point is also assigned a bus/device/function number to uniquely identify it from other end points in the system. With these parameters set a system host can communicate with all end points in the system. In fact, all end points can communicate with all other end points within a system. However, communication in PCI Express is limited to two end points, a source and a destination, at a time. The PCI Express standard specifies one limited form of broadcasting. That is, if the transaction is a TLP type Message (Msg) denoted by a Format and Type field of 0110011, the transaction is broadcast from the Root Complex to all end points. This broadcast is for system management and configuration and is not applicable to data transport transactions. | 20040213 | 20090526 | 20050707 | 75880.0 | 1 | MATTIS, JASON E | MULTICASTING IN A SHARED ADDRESS SPACE | UNDISCOUNTED | 0 | ACCEPTED | 2,004 |
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