A method of manufacturing a semiconductor device includes a step of forming a device region 5 that is separated by a device-separation insulating film 4 formed in a part of an SOI layer, a step of forming a gate insulating film 6a on a device region 5 so that the device region 5 can be exposed on both sides of the gate insulating film 6a, a step of forming a gate electrode 7a with polysilicon on the gate insulating film 6a, a step of adjusting the area of exposed silicon so that the area of exposed silicon can be a prescribed area by forming at least either a pseudo region 5b or a pseudo electrode 7b to control the growth rate in growing an epitaxial layer 9, and a step of conducting low-temperature epitaxial growth of silicon.

1. Field of the Invention
The present invention relates to a semiconductor device and a method of manufacturing the same. More specifically, the present invention relates to a semiconductor device that includes a device formed in a semiconductor layer on an insulating film, and a method of manufacturing the same.
2. Background Information
Related examples of a semiconductor device that include an MOS transistor formed with a semiconductor process are described in Japanese Patent Publications JP-A-2000-150806 and JP-A-11-003992, which are hereby incorporated by reference.
Japanese Patent Publication JP-A-2000-150806 discloses a semiconductor device, which includes device-separation insulating films, an active region, a pseudo region, a gate electrode, a pseudo conductive film, and an interlayer insulating film. The device-separation insulating films are buried in trenches formed on a surface of a semiconductor substrate of a bulk. The active region and the pseudo region are separated by a device-separation insulating film on a surface of a semiconductor substrate. The gate electrode is formed on an active region. The pseudo conductive film is formed on a device-separation insulating film at almost the same height with a gate electrode. The interlayer insulating film covers the gate electrode and the pseudo conductive film. In the semiconductor device, the pseudo region inhibits occurrence of erosion, for which the active region is excessively polished, and of dishing, for which the insulating film in a trench is excessively polished at the middle.
The device-separation insulating film is formed by the following steps. That is, the device-separation insulating film is buried in trenches that are formed on a surface of the semiconductor substrate of the bulk, and then the insulating film is polished by the CMP method so that the insulating film remains only in the trenches. If the area of the active region is too small compared to the area of the trench in polishing the device-separation insulating film, there is a possibility that excessive of erosion may occur in the polish in the active region compared to the polish in the insulating film. Also, in polishing the device-separation insulating film that is buried in a wide trench, there is a possibility dishing might occur in the thickness of the device-separation insulating film as the middle gets thinner than at the edges.
Accordingly, the semiconductor device inhibits the occurrence of erosion and dishing by increasing the substantive area of the active region by forming a pseudo region and decreasing the area of the trench at the same time.
In addition, the pseudo-conductive film improves planarization of the interlayer insulating film. In conducting planarization of the interlayer insulating film that covers the gate electrode by polishing it with the CMP method, polishing speed highly depends on a difference of elevation of a substrate pattern. In a part that there are few gate electrodes, the difference of elevation in the substrate pattern enlarges and polishing speed in the interlayer insulating film varies inside the film because a gate electrode is a part that projects from an active region. Therefore, the difference in elevation in the substrate is reduced by making the part projecting from an active region dense by allocating a pseudo electrode that has a similar height with the gate electrode.
Japanese Patent Publication JP-A-11-003992 also discloses a semiconductor device in which a pseudo region (a dummy device region) and a pseudo conductive film (a dummy gate electrode) are formed, as described in Japanese Patent Publication JP-A-2000-150806. Furthermore, in the semiconductor device, a dummy electrode has an electrical interconnection with a pseudo region in order to prevent a state in which the dummy gate electrode is in a state of floating. To put it concretely, a part of the dummy gate electrode is formed on a pseudo region, and the dummy gate electrode and the pseudo region are connected by a titanium silicide layer.
By the way, in recent years, an MOS transistor can be manufactured with a Silicon on Insulator (SOI) substrate to reduce power consumption. Especially, power consumption is effectively reduced with a full depletion layer type SOI, which inhibits the short channel effect by making an SOI layer (a semiconductor layer on an insulating film) thin and is operated in a full depletion layer. In a full depletion layer type SOI, sheet resistance increases because thickness of an SOI layer is formed at 50 nanometers or less. Accordingly, R. Chau et al., in "A 50 nm depleted-substrates CMOS transistor (DST)," IEDM 2001, pp. 621–624, which is hereby incorporated by reference, describes a method of reducing sheet resistance by forming a source drain that is thicker than a channel layer by epitaxial growth of silicon in the source drain.
In conducting epitaxial growth of silicon on an extremely thin SOI layer, such as an SOI layer in a full depletion layer type SOI, silicon in the SOI layer agglutinates when epitaxial growth is conducted at a general growth temperature (e.g., 800 degrees C.). Therefore, epitaxial growth has to be conducted at a low temperature (e.g., 700 degrees C. or below) so that the SOI layer does not agglutinate. However, the inventor of the present invention found that growth rate depends more on the density of silicon that is exposed on a substrate pattern than other growth conditions such as gas concentration or pressure.
FIGS. 1(a) to 1(c) a diagrams illustrating a part with high pattern ratio of silicon and a part with low pattern ratio of silicon in a semiconductor wafer. Here, the pattern ratio of silicon means a proportion of an area of silicon that is exposed on a substrate to epitaxial growth of silicon to the total area of the substrate. A growth rate v is expressed in a formula v/v0, on the basis of the growth rate v/0 when the pattern ratio is 100%. FIG. 1(b) is a diagram illustrating a part with a high pattern ratio of silicon in the semiconductor wafer. The part surrounded by an outside rectangle shows the whole of a part with high pattern ratio of silicon in the semiconductor wafer. Further black parts show a part of silicon that is exposed. The pattern ratio of the part with a high pattern ratio is a proportion of the area of the black parts to the area of the whole of the part with the high pattern ratio surrounded by the outside rectangle. For example, the pattern ratio of the part with high pattern ratio of silicon is 80% or more. FIG. 1(c) is a diagram illustrating a part with a low pattern ratio of silicon in a semiconductor wafer. The part surrounded by an outside rectangle shows the whole of a part with a low pattern ratio of silicon in the semiconductor wafer. Further, the black part shows the part of silicon that is exposed. The pattern ratio in a part with low pattern ratio of silicon is a proportion of the area of a black part to the area of the whole of the part with a low pattern ratio surrounded by the outside rectangle. For example, the pattern ratio in a part with the low pattern ratio of silicon is 10% or less.
FIGS. 2(a) and 2(b) are charts illustrating a growth rate of silicon for the x-axis and the y-axis in low-temperature epitaxial growth. As shown in FIG. 1(a), horizontal axes, x and y in FIGS. 2(a) and 2(b), are used to show coordinates of the x-axis and y-axis arranged such that the middle of a wafer is set to be the origin. In both the x-axis and y-axis, a coordinate value on the edge of a part of that chip is formed to be set to one. In the charts, a measurement result in a part with high pattern ratio is obtained when the whole of the wafer is the part with high pattern ratio (pattern ratio is 80% or greater), and a measurement result in the part with a low pattern ratio is obtained when the whole of the wafer is a part with a low pattern ratio (pattern ratio is 10% or less). Also, in the measurement, the growth rate is measured by conducting epitaxial growth of silicon with a Vapor Phase Epitaxy (VPE) method. Epitaxial growth is conducted at 730 degrees C. of atmosphere temperature by using SiH2Cl2 as gas to grow silicon and HCl as a gas to conduct etching of silicon that adheres to a device-separation insulating film.
In reference to FIGS. 2(a) and 2(b), it is obvious that the growth rate in the low-temperature epitaxial growth of silicon decelerates in a part with a low pattern ratio of silicon (pattern ratio is 10% or less), compared to a part with a high pattern ratio of silicon (pattern ratio is 80% or more), when an identical process is used (i.e., when growth conditions such as gas used and atmosphere temperature are identical) and when growth rate is measured along the x-axis and y-axis.
Therefore, in conducting low-temperature epitaxial growth of silicon with the identical process, if the pattern ratio of silicon varies from place to place on an identical chip extra space, an identical wafer, or a plurality of wafers, that is, if the density of exposed silicon varies from place to place, the growth rate varies from place to place and the film thickness of the epitaxial layer is uneven because film thickness of the epitaxial layer is thicker in a part in which the density of exposed silicon is high than in a part in which the density of exposed silicon is low.
However, the problem of the growth rate in low-temperature epitaxial growth depending on the density of exposed silicon is described neither Japanese Patent Publications JP-A-2000-150806 and JP-A-11-003992, nor the nonpatent literature described above. Both Japanese Patent Publications JP-A-2000-150806 and JP-A-11-003992 describe a step of forming a pseudo conductive film and a pseudo region that are made of silicon. However, the pseudo conductive film makes a part that is projected from an SOI layer dense, and the pseudo region prevents a region of silicon in the SOI layer from being much smaller than that of a device-separation insulating film to inhibit occurrence of erosion and dishing in polishing a device-separation insulating film. Therefore, the pseudo conductive film and the pseudo region are not used to adjust the density of exposed silicon.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved semiconductor device and method of manufacturing the same. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.

Semiconductor device and method of manufacturing the same


In a semiconductor device of the present invention, a clock is not changed instantaneously but it is changed over maximum N+1/M clocks (N: integer not less than 2) by shifting delay cells in a step by step manner to make the phase state of a previous reference signal and the phase state of a present reference signal coincide with each other, whereby the clock is synchronized with the reference signal with accuracy, and the duty of the output clock is kept constant. With this semiconductor device, it is possible to prevent the duty of the clock from being discontinuous when a signal whose reference signal does not coincide with the clock is inputted and reset is made to a rising edge of this reference signal.

In recent years, digitization of video signal processing has been advanced, and a semiconductor device which performs video signal processing using a clock synchronized with a reference signal such as a horizontal sync signal has been utilized. As an example, there is a semiconductor device disclosed in Japanese Published Patent Application No. 2002-290218.
FIG. 21 shows a configuration example of such conventional semiconductor device.
A conventional semiconductor device shown in FIG. 21(a) includes a clock input terminal 101, delay cells 102 to 105, a phase comparator 106, a controller 107, a reference signal input terminal 108, a selector 109, and a sync clock output terminal 110.
The delay cells 102 to 105 shift the phase of a clock inputted to the clock input terminal 101, each by 1/4 clock.
The phase comparator 106 compares the phase of a clock that is one clock after the input clock with the phase of the output clock of the delay cell 105.
The controller 107 controls the delay values of the delay cells 102 to 105 on the basis of the output of the phase comparator 106.
The selector 109 selects, as a sync clock, a clock whose phase is closest to the phase of the reference signal inputted to the reference signal input terminal 108 from among the clocks outputted from the respective delay cells 102 to 105, and outputs the sync clock through the sync clock output terminal 110 to the outside.
A description will be given of the operation of the conventional semiconductor device constructed as described above, with reference to FIG. 21(b).
A clock inputted to the clock input terminal 101 is delayed by the four stages of delay cells 102 to 105. Then, in the phase comparator 106, the phase of a clock that is one clock after the clock inputted to the clock input terminal 101 is compared with the phase of the clock outputted from the delay cell 105, and the delay values of the respective delay cells 102 to 105 are controlled by the controller 107 on the basis of a phase difference that is detected as a result of the comparison.
The selector 109 selects an edge clock which is a rear part of the reference signal and is closest to the phase of the reference signal, from among the delay clocks outputted from the respective delay cells 102 to 105. In this example, the clock outputted from the delay cell 103 is selected as a sync clock, and the sync signal is outputted through the sync clock output terminal 110.

Matsushita Electric Industrial Co., Ltd.


The present invention relates to a process for the production of conjugated linoleic acid and a process for the production of triglycerides with an increased content of conjugated linoleic acid. Moreover, the invention relates to a nucleic acid sequence; a nucleic acid construct, a vector and transgenic organisms comprising at least one nucleic acid sequence or one nucleic acid construct which encodes a polypeptide with conjugated linoleic isomerase activity. Furthermore, the invention relates to the use of a microorganism of the genus Bifidobacterium as a probiotic.

Fatty acids and triglycerides have a multiplicity of applications in the food industry, animal nutrition, cosmetics and in the pharmaceutical sector. Depending on whether they are free saturated or unsaturated fatty acids or triglycerides with an increased content of saturated or unsaturated fatty acids, they are suitable for a very wide range of applications; thus, for example, polyunsaturated fatty acids are added to baby formula to increase the nutritional value. The various fatty acids and triglycerides are obtained mainly from microorganisms such as Mortierella or from oil-producing plants such as soya, oilseed rape, sunflowers and others, where they are usually obtained in the form of their triacyl glycerides. Alternatively, they are obtained advantageously from animals, such as fish. The free fatty acids are prepared advantageously by hydrolysis.
Whether oils with unsaturated or with saturated fatty acids are preferred depends on the intended purpose; thus, for example, lipids with unsaturated fatty acids, specifically polyunsaturated fatty acids, are preferred in human nutrition since they have a positive effect on the cholesterol level in the blood and thus on the possibility of heart disease. They are used in a variety of dietetic foodstuffs or medicaments.
Especially valuable and sought-after unsaturated fatty acids are the so-called conjugated unsaturated fatty acids, such as conjugated linoleic acid. A series of positive effects have been found for conjugated fatty acids; thus, the administration of conjugated linoleic acid reduces body fat in humans and animals, and increases the conversion of feed into body weight in the case of animals (WO 94/16690, WO 96/06605, WO 97/46230, WO 97/46118). By administering conjugated linoleic acid, it is also possible to positively affect, for example, allergies (WO 97/32008) or cancer (Banni et al., Carcinogenesis, Vol. 20, 1999: 1019–1024, Thompson et al., Cancer, Res., Vol. 57, 1997: 5067–5072).
Conjugated linoleic acid (=CLA) is an intermediate of linoleic acid metabolism in ruminants. CLA refers to a mixture of positional and geometric isomers of linoleic acid, involving double bonds at positions 9 and 11, 10 and 12 or 11 and 13, and has gained considerable attention in recent years because of the many beneficial effects attributed to the cis-9, trans-11 and trans-10, cis-12 isomers, in particular. These include anti-carcinogenic activity, antiatherogenic activity, the ability to reduce the catabolic effects of immune stimulation, the ability to enhance growth promotion and the ability to reduce body fat (Martin and Banni, 1998 for review, and references therein). The isomers can differ positionally (mainly at positions 7 and 9, 9 and 11; or 10 and 12) (Ha et al., 1987) and geometrically (cis-cis, cis-trans, trans-cis, trans-trans). Of the individual isomers of CLA, cis-9, trans-11-octadecadienoic acid has been implicated as the most biologically active because it is the predominant isomer incorporated into the phospholipids of cell membranes, liver phospholipids and triglycerides (Kramer et al., 1998). This is the only isomer incorporated into the phospholipid fraction of cell membranes of animals fed a mixture of CLA isomers (Ha et al., 1990; Ip et al., 1991). This isomer is also the predominant dietary form of CLA, obtained from fats derived from ruminant animals, including milk, dairy products and meat (Chin et al., 1992, O'Shea et al., 2000).
Studies have shown that CLA may have potential in the prevention of a wide range of human medical conditions, and a number of potential health benefits have been described for CLA, including as mentioned above anticarcinogenic activity, antiatherogenic activity, potential in the prevention of diabetes, obesity and bone disorders. Given that dietary CLA has the potential to beneficially affect human health, it is important to identify effective strategies to enrich the natural form of CLA in food products. Currently, the effective level of dietary CLA for disease prevention in humans is not known. Furthermore, the long-term health implications of a low dietary CLA intake at critical stages throughout life are unknown, as for example in formula-fed infants, compared with breast-fed infants, the latter group receiving a relatively higher CLA intake. In the rodent model, dietary CLA was more effective as an anticarcinogen when consumed during periods of active mammary gland development (Ip et al., Nutr. Cancer, 1995, 24: 241–247), which may indicate that increased CLA intake during adolescence might preferentially decrease the risk of cancer in women.
Few data concerning the CLA intake are available. In Germany the daily CLA intake has been estimated to be 0.36 g/day for women and 0.44 g/day for men (Fritsche et al., 1998). CLA in human tissue is predominantly the isomere cis-9, trans-11-octa-decadienoic acid (>95%), three minor isomers have also been identified. Trans-9, trans-11–18:2, cis-9, cis-11–18:2 and trans9, cis-11–18:2, [Fritsche et al., Zeitschrift Lebensmittel. Untersuchung Forschung A-Food Research & Technology 205:415–418 (1997)]. The origin is thought to be dietary and the consumption of cheddar cheese, a good source of CLA, has been shown to enhance plasma CLA levels in men, [Huang et al. Nutr. Res. 14:373–386 (1994)]. In another study it was found that the relationship between milk fat intake and the occurence of cis-9, trans-11-octadecadienoic acid in human tissue was significantly correlated, [Jiang et al., Am. J. Clin. Nutr. 70:21–29 (1999)]. Safflower oil, a rich source of linoleic acid, did not increase plasma CLA levels suggesting that the intestinal flora of humans do not possess the ability to convert linoleic acid to conjugated linoleic acid, however a CLA increase was observed in some subjects [Herbel et al., Am. J. Clin. Nutr. 67: 332–337 (1998)]. Dietary trans fatty acid has been shown to increase serum CLA, [Salminen et al., Nutritional Biochemistry 9: 93–98 (1998)]. It was in this study concluded that CLA may be formed by desaturation of trans fatty acid possibly by a liver enzyme as has been described for rats.
The principial dietary sources of CLA are milk, dairy products and meat from ruminants, but as a result of differences in environmental conditions and diet of the ruminant species, the CLA content of milk and beef fat vary substantially [Michelle et al., Advances in Conjugated Linoleic Acid Research, Volume 1 (1999)]. Among the richest dietary sources of CLA are milk, dairy products, beef and lamb (Chin et al., J. Food Comp. and Anal., 1992, 5: 185–197; Fritsche and Steinhart, Z. Lebensm. Unters. Forsch., 1998, A206: 77–82 and Lipid, 1998, 6S: 190–210).
In fat from ruminant meats and dairy products, the cis-9, trans-11 CLA isomer is present at 80–90% of the total CLA isomers (Chin et al., J. Food Comp. and Anal., 1992, 5: 185–197).
As mentioned above the origin of CLA in foods is mainly due to the biohydrogenation of dietary linoleic acid by anaerobic rumen bacteria. Accordingly the main dietary sources of CLA are meat from ruminant animals and dairy products, and the main CLA isomer found is cis-9, trans-11-C18:2, (80–90%). In uncooked meats, lamb and beef answer for the highest CLA levels 5.6 mg/g of fat in lamb and 4.3 mg/g of fat in beef (Chin et al., 1992; Fritsche and Steinhart, 1998 ). CLA levels in milk varies with season, highest values occuring when pastures are lush and rich in PUFAs, hence levels of CLA in dairy products such as cheese also varies. In vegetable oils CLA is present in low amounts (0.2–0.7 mg/g fat) and contain higher levels of the isomer trans-10, cis-12-C18:2 (˜40%) (Chin et al., 1992). Since fatty acids with conjugated double bonds are a well-known phenomena in plants, specific enzyme systems are belived to be involved. Meats from non-ruminant animals can contain CLA in lower amounts and it may occur from dietary sources such as feeding meat meal. It could also be explained by formation of CLA by intestinal flora as has been shown for rats (Chin et al., J. Nutr., 1993, 124: 694–701). CLA can also be produced by free radical-based double bond shifting during autooxidation and during partial hydrogenation performed industrially.
CLA can be manufactured synthetically from alkaline isomerization of linoleic and linolenic acids, or vegetable oils containing linoleic or linolenic acids. Two reactions are catalyzed when heating oil at 180° C. under alkaline conditions; hydrolysis of the fatty acid ester bond from the triglyceride lipid backbone, which produces free fatty acids, and conjugation of unconjugated unsaturated fatty acids with two or more approproiate double bonds (WO 99/32604). This method produces about 20–35% cis-9, trans-11 CLA and about the same amount of trans-10, cis-12 CLA, but enrichment of either of the isomers relative to the other is possible by using a fractional crystallization procedure.
In addition other isomers are produced mainly trans, trans isomers.
The chemical preparation of conjugated fatty acids, for example conjugated linoleic acid, is also described in U.S. Pat. Nos. 3,356,699 and 4,164,505.
The presence of conjugated unsaturated fatty acids in milk fat was first established by Booth et al. Bioch. J. 29, 133–137 (1935), who also showed that these fatty acids increased in milk fat when cows were turned out to pasture after winter, by demonstrating an increased absorption of the fatty acids in the ultra-violet (UV) region at 230 nm. CLA is formed in the rumen during microbial biohydrogenation of dietary linoleic acid (Kepler and Tove, 1969 Methods in enzymology Vol XIV, p105; J. Biol. Chem., Vol 246, No. 14, 1970: 3612–3620 and J. Biol. Chem., Vol 246, No. 9, 2765–2771). The complete biohydrogenation of linoleic acid in the rumen is a three step process, yielding C 18:0, stearic acid, as an end product. The first reaction, the conversion of linoleic acid to cis-9, trans-11 CLA by linoleic acid isomerase of rumen bacteria occurs very rapidly, followed by slower conversion to trans-11-C 18:1 (FIG. 1). Some of the CLA formed in the rumen is absorbed into blood and incorporated into milk fat. In addition to the biohydrogenation reaction leading to CLA synthesis, CLA can also be produced endogenously from trans-11-C 18:1 in mammary tissues. Trans-11-C 18:1 accumulates in the rumen due to the slower conversion step to stearic acid, and following absorption from the digestive tract is utilized by different tissues e.g. the mammary gland as a substrate for CLA synthesis by the action of Δ-9-desaturase. Indeed, this may be the major pathway of CLA synthesis in lactating cows, accounting for about 64% of the CLA in milk fat.
In addition member of strains of propionibacteria were previously identified to synthesise CLA from linoleic acid by Jiang et al. (1998).
WO 99/29886 describes the use of certain bacterial strains found among food grade bacteria, particularly among dairy starter cultures, which have the ability to produce CLA in vitro by fermentation. Furthermore WO 99/29886 decribes that said bacteria may be used to provide food or feed products enriched in CLA, and also pharmaceutical products containing CLA as active ingredients.
Isomerases are enzymes which bring about an isomerisation of substrate. Linoleic acid isomerase catalyzes the isomerisation reaction of lionoleic acid to cis-9, trans-11-octadecadienoic acid. This membrane bound enzyme was isolated and characterised by Kepler & Tove (1969). The isomerisation reaction occurs in the middle of a long hydrocarbon chain remote from any functional group and requires no cofactors. The enzyme exhibits max activity with substrates linoleic and linolenic acid within a narrow concentration range. Three parameters are involved in the binding of substrate to linoleic acid isomerase: 1.) the π system of a substrate double bond, 2.) hydrophobic interaction and 3.) hydrogen bonding of the substrate carboxyl group. A proposed model for the isomerization of linoleic acid by linoleic acid isomerase is illustrated in FIG. 2. Pictured at the active site are an electrophile (E) that interacts with one of the substrate double bonds, and two basic centers, one of wich (B) is hydrogen bonded to the carboxyl group and the other (B—H) which serves as a donor for the hydrogen added at C-13 (FIG. 2).
WO 99/32604 describes a linoleate isomerase from Lactobacillus reuteri. The enzyme activity leads to the conversion of linoleic acid to six different CLA species which are as follows: (cis,trans)-9,11-CLA, (trans,cis)-10,12-CLA, (cis,cis)-9,11-CLA, (cis,cis)-10,12-CLA, (trans,trans)-9,11-CLA and (trans,trans)-10,12-CLA.
The disadvantages of the abovementioned process is that the yield of the reaction is very low, the purity of the CLA produced is for an industrial process not sufficient and that the process takes place with only low space-time yields. This leads to economically unattractive processes.
Thus, there is still a great need for a single, economic birthdenological industrial process for the production of CLA which does not have the abovementioned disadvantages and therefore for new genes which encode enzymes which participate in the biosynthesis of conjugated linoleic acid and which allow to synthesize and produce it on an industrial scale.

Conjugated linoleic acid isomerase and a process for the production of conjugated linoleic acid


A reduced-thickness backlighter for an autostereoscopic display is disclosed having a lightguide and at least one light source parallel to an edge of the lightguide so as to be substantially coplanar with the lightguide. The lightguide is provided with a first surface which has a plurality of reflective linear regions, such as elongated grooves or glossy lines, parallel to the illuminated edge of the lightguide. Preferably the lightguide further has a second surface which has a plurality of lenticular lenses for reimaging the reflected light from the linear regions into a series of thin vertical lines outside the guide. Because of the reduced thickness of the backlighter system, autostereoscopic viewing is enabled in applications requiring thin backlighter systems. In addition to taking up less space, the reduced-thickness backlighter uses less lamps and less power. For accommodating 2-D applications, a 2-D diffuser plate or a 2-D lightguide parallel to the 3-D backlighter is disclosed for switching back and forth between 3-D viewing and 2-D viewing.

U.S. Pat. Nos. 4,717,949, 4,829,365, 5,036,385, 5,040,878, and 5,457,574 disclose autostereoscopic display devices with an array of thin, vertical, parallel, equidistant, light emitting lines behind a flat, transmissive, electronically controlled display panel, such as a liquid crystal display (LCD), to generate for an observer a perception of three dimensional images. These patents describe various means for generating an array of thin lightlines as the means for creating stereoscopic images, however they all utilize light sources which are not coplanar with their lightguides. The backlighters described in these prior patents vary in cost and complexity, but they all share the disadvantage of having backlighters which are too thick for some of today's applications, such as lap top computers, and which consume more power than is desirable, especially for battery operated devices.
Planar or edge-lit backlighters are known in the prior art such as shown in U.S. Pat. Nos. 5,126,882, 5,339,179, and 5,359,691. These types of backlighters are useful in lap top computers and the like, however none of these patents disclose how to incorporate autostereoscopic technology into planar backlighters. Therefore, there is a need for a simple, low cost autostereoscopic system capable of providing clear, bright, high resolution images with a relatively thin planar back lighting system as is necessary for use in today's thin portable computer systems, televisions, and other electronic display devices. There is also a need to provide a planar back lighting system with the capability of switching back and forth from 3-D to 2-D images. There is further the need to provide an autostereoscopic system of smaller size, which uses less lamps and less power, takes up less space, and is less expensive to produce than existing systems.

Reduced-thickness backlighter for autostereoscopic display and display using the backlighter


An inkjet system including a printhead with an ink-fillable chamber operatively connected to a piezoelectric actuator and provided with a nozzle for the ejection of ink drops in response to the energization of the actuator, which actuator is connected to a measuring circuit for measuring an electrical signal generated by the actuator in response to the deformation thereof, wherein the system is configured such that a natural frequency of said system corresponds substantially to a natural frequency of a disturbance in the system.

The present invention relates to an inkjet system including a printhead comprising an ink-fillable chamber operatively connected to a piezoelectric actuator and provided with a nozzle for the ejection of ink drops in response to the energization of the actuator, said actuator being connected to a measuring circuit for measuring an electric signal generated by the actuator in response to the deformation thereof. The present invention also relates to a method of making such a system and use of said system in forming an image on a receiving material.
A system of this kind is known from European Application EP 1 013 453. This system forms part of an inkjet printer with which receiving materials can be printed. The known system is of the piezo type and has a printhead with an ink chamber (also termed an "ink duct" or, briefly, a "duct") operatively connected to a piezoelectric actuator. In one embodiment the ink chamber has a flexible wall which is deformable by energization of the actuator connected to said wall. Deformation of the wall results in an acoustic pressure wave in the chamber which, given adequate strength, will result in ejection of an ink drop from the nozzle of that chamber. The pressure wave in turn, however, results in a deformation of the wall, and this can be fed to the piezoelectric actuator. This will generate an electrical signal under the influence of its deformation.
From this application it is recognized that an analysis of this signal can provide information as to the state of the ink chamber corresponding to the particular actuator. Thus it is possible to derive from the signal whether there is an air bubble or some other disturbance in the chamber, whether the nozzle is clean, whether there are mechanical defects in the ink chamber, and so on. In principle, any disturbance of influence on the pressure wave can be traced by analysing the signal.
A disadvantage of the known method is that the signal generated by the piezoelectric actuator in response to its deformation by the pressure wave in the duct is often very complex, apart from the possible presence of random disturbances (noise). It has been found that the pressure wave in the duct is not a simple sine curve or some other simple wave configuration. This would, in fact, result in a comparably simple electrical signal. Apparently the pressure wave is not solely determined by the deformation of the actuator directly preceding the drop ejection, but there are also a number of other events which influence the pressure wave. Another consequence of this complex pressure wave is that the signal generated by the actuator as a result of this pressure wave is also very complex. Analysis of such a complex signal requires a complex, preferably digital, measuring circuit and/or relatively long processing times. This is particularly disadvantageous, especially for printers with many ink chambers in which each ink chamber of the printer is checked for disturbances after each energization. Making each chamber measurable by such a complex circuit after each energization is economically unattractive, and in addition it will often be difficult to round off an analysis within the time available until the next ink drop should be ejected from this chamber (typically 10−4 seconds). It should be clear that, particularly for applications in which high print quality is required, for example the printing of color photographs and making publicity posters, it is desirable to check each ink chamber after each energization.

Inkjet system, method of making this system, and use of said system


A safety closure is provided for threadingly engaging a neck portion of a container. The safety closure includes a cap portion and a tamper-indicating band connected to a lower end of a peripheral side wall of the cap portion by a plurality of frangible bridge segments. A cap lug projects downwardly from an outer surface of the cap portion and is sized to engage a band lug projecting upwardly from an outer surface of the tamper-indicating band. At least one bead segment projects inwardly from an inner surface of the tamper-indicating band and is sized to engage a continuous bead projecting outwardly from an outer surface of the container neck portion to prevent removal of the tamper-indicating band therefrom upon a first application thereto. Removal of the cap portion from the container neck portion a first time breaks the plurality of frangible bridge segments, thereby detaching the cap portion from the tamper-indicating band and permitting removal of the cap portion from the container neck portion, while retaining the tamper-indicating band on the container neck portion for subsequent use.

1. Technical Field of the Invention
The present invention relates to safety closures for use on containers. More particularly, the present invention relates to a safety closure for use on a container, wherein the safety closure includes a tamper-indicating band having child-resistant features.
2. Description of the Related Art
It is often desirable to provide a safety closure for use on a container neck portion, wherein the safety closure includes tamper-indicating means integrally formed therewith and wherein the tamper-indicating means includes a removable, detachable or frangible portion thereof which must be removed, detached or otherwise broken prior to a first removal of the safety closure from the container neck portion. In the absence of an unbroken tamper-indicating means, an individual is thereby notified that the container has been previously opened. It is therefore desirable to provide a safety closure for use on a container neck portion, wherein the safety closure is provided with tamper-indicating means.
For example, U.S. Pat. No. 4,341,318 to Smalley teaches a closure with a child-resistant tamper-proof band frangibly attached thereto and removable therefrom. Removal of the closure from a container neck portion to which the closure has been snap-fit thereon requires prior removal of the tamper-proof band from the closure. Similarly, U.S. Pat. No. 4,573,599 to Fillmore teaches a closure having a tamper-indicating band which must be removed from the closure prior to removal of the closure from a container neck portion to which the closure has been snap-fit thereon. However, it is furthermore desirable to provide a safety closure threadingly fit upon a container neck portion, wherein the safety closure includes a tamper-indicating band frangibly attached thereto, and wherein the tamper-indicating band remains affixed to the container neck portion upon a first removal of the safety closure therefrom.
For example, U.S. Pat. No. 5,398,829 to Stubbs teaches a tamper-resistant, child-resistant cap assembly having a cap portion connected to a captive band by a tear-away portion. Upon removal of the tear-away portion, the cap can be removed from a container neck portion to which the cap has been snap-fit thereon, wherein the captive band remains affixed to the container neck portion. However, it is furthermore desirable to provide a safety closure threadingly fit upon a container neck portion, wherein the safety closure includes a tamper-indicating band frangibly attached thereto, wherein the tamper-indicating band remains affixed to the container neck portion upon a first removal of the safety closure therefrom, and wherein the tamper-indicating band includes locking means for engaging cooperating locking means provided on the safety closure.

Safety closure having tamper-indicating means


Systems and methods for evaluating probe signal level readings in a manner that allows a low water detector to distinguish between a probe that is under a fluid level, or is above the fluid level and either being splashed or is within a foam. Low water detectors which utilize these systems and methods are also provided. The detectors generally utilize a representative probe reading, and a dynamic indicator between probe readings, for a set of probe readings taken in a time period to detect low water levels, foam, or surge.

(1) Field of the Invention
The present invention relates to a fluid detector which can differentiate between liquid fluid and foam, bubbles, or surges of the fluid; more particularly, it is to a device generally used to detect a low water condition in a boiler system
(2) Background of the Invention
Boilers have been used for generating steam in radiant heating systems in both residential and commercial applications for a number of years. The systems generally operate by heating boiler water to produce steam. The steam is then distributed through a piping system and radiators to heat the facility. Once distributed to radiators, the resultant steam condenses and returns to the boiler to be heated again and redistributed.
Steam boiler systems can be damaged if they have too much water or if foaming occurs within the boiler. In either case, since steam exits the boiler at high velocities, it can propel liquid water from the boiler into the piping system. This condition, known to the industry as priming, occurs when the high-velocity steam drives slugs of water through the piping system and equipment. When these slugs of water impact heating system components and piping, it causes water hammer which can lead to damage of piping, valves, or heating system components such as radiators. When foaming occurs in a steam boiler, priming becomes a more frequent condition. For these reasons, boiler systems are filled to their desired water level during installation and steps, such as cleaning the boiler and piping or chemical treatments, are taken to control foaming in the boiler.
Because of the way these boiler systems operate, it is also necessary that there be sufficient water in the boiler system at all times. If the water level drops too low, the water in the boiler can flash to steam explosively, seriously injuring or killing people or damaging the boiler, facility or both. Boilers generally include a Low Water Cutoff (LWCO) which will serve to turn off the heat source for the boiler if the water level drops below a predetermined safe level. The LWCO therefore serves as a defense against the system being operated with insufficient water and indicates when additional water needs to be added.
There are many types of different systems used in an LWCO to detect the low water condition. In the simplest example, a simple float switch may be used. Historically, these float style LWCO devices function reliably, so long as they receive proper daily or weekly maintenance like blowdown to remove deposits that can cause moving parts to get stuck in a position that falsely indicates a proper water level. Since maintenance is often not performed regularly or sometimes not performed at all, mechanical type LWCO devices are, therefore, subject to improper operation on a regular basis. For this reason, the industry has adopted more sophisticated electronic probe style LWCO devices which have no moving parts.
Probe style LWCO devices generally utilize the electrical conductivity of a fluid, in this case the boiler water, to complete an electrical circuit between two conductors of the probe. One conductor is placed low down in the tank so as always to be in fluid while the other conductor is placed at the desired minimum operating level of water. When both conductors are underwater, electric current can pass through the water between the two conductors completing the electric circuit between them and indicating a safe water level. When the level drops below the level of the upper conductor, the electric circuit is broken which indicates a low water condition.
When the fluid level is stable in the vessel and the surface line is well defined, this type of technology works quite well. In steam boiler applications, however, the stability of the water level and the definition of the water line can degrade during operation. For instance, boiling water will often surge due to heat underneath creating bubbles which pass through the water disrupting the water line. Further, differences in heat throughout the boiler water can further cause water movement which can disrupt the water line making a constantly changing water level. Under intense boiling conditions, the water line becomes very undefined, making it difficult to ascertain the actual water level.
Steam boilers also act under pressure. When the boiler has reached a desired operating pressure, it enters a relatively stable state where steam can be removed and the water boils in a fairly controlled fashion. When heating loads increase rapidly, the additional load on the boiler can result in much more steam suddenly being removed from the boiler, decreasing the pressure in the boiler. This can result in the water being heated more aggressively and boiling more violently as the pressure falls off. A violent boil of water will generally lead to a significant disruption of the water line due to splashing of the water inside the fluid vessel. Further, water which is not completely clean can generate a foam which can float on the surface of the water or even fill the inside of the boiler.
Traditional LWCO technologies generally determine the water level by examining the resistance between the two probes as a method to determine if the conductive fluid is between the probes. The strength of the LWCO signal transmitted via the boiler water is related to the amount of surface area of the probe in contact with the liquid. Therefore, in a well behaved system, as the water line slowly drops across the surface of the upper probe, the signal will decrease as resistance effectively increases. In the boiler system, however, the presence of steam bubbles within the water and an imprecise water line can lead to false readings as the surface area of the probe actually in contact with liquid water can change from instant to instant, even when the water line is significantly above the probe.
In order to prevent false indications of a low water level due to the changes in probe signal levels due to surging or bubbling, traditional low water detectors average the probe signal over a period of time, and then use the average to determine whether there has been a sufficient change over time to indicate a low water level. In the event of small changes to the average over a significant time period, the low water detector will often adjust to accept new values as the expected signal levels (or baseline) and will only trigger a low water condition in the event of a major change from that baseline. These types of systems effectively compensate for small changes in the conductivity such as through alteration of the water chemistry from interaction with the pipes.
The problem with averaging systems is that having their probe in foam or under relatively violent splashing will generally still produce an average probe signal within the period that is similar to the average probe signal when liquid is covering the probe. The alternative problem is, however, that not using the average produces a large number of false indications for low water as the water surges and bubbles during the boiling process but is still at a sufficient operating level.
To attempt to compensate for the false low water indications produced by dynamic water levels, while preventing premature restoration from a low water condition, low water cutoff devices often incorporate a delay feature that requires water to be continuously present before a low water condition is removed or continuously absent for a predetermined length of time before a low water condition is indicated. In some other systems, the low water detection system attempts to correct for dynamic effects by periodically shutting off the boiler's burner circuit and keeping it off for a predetermined duration or settling period. At the end of this period, it is presumed that the dynamic system has stabilized or settled and therefore the low water detection device can take a more accurate reading of whether it is within fluid or not.
While both these options help with the problem of inaccurate detection, numerous issues plague the methods. Requiring continuous low water indications before triggering a low water condition can often make a low water condition less detectable by making it harder to detect foam or surge which will result in less detection accuracy. Further, during a settling period, foam and steam also have an opportunity to condense and return to the boiler, replenishing the water level and possibly altering the determination. Alternatively, a heavy foam may not recondense, leaving the probe still within the foam at the end of the settling period and having the probe still generate an inaccurate reading. The short cycling of the heating cycle created by periodically turning the burner off can also cause numerous problems that lead to premature failures of the heating system resulting in potentially high repair or replacement costs. Further, the system will not be able to meet demands for heat when the shut-off period is implemented.

Methods for detecting fluid surge conditions


A coupling device for a split, in-line engine is provided. The coupling device may be configured to connect a first section of a crank shaft to a second section of the crank shaft of the engine. Further, the coupling device may be positioned at at least one main bearing of the crank shaft. Further still, the coupling device may be encircled by the at least one main bearing.

The rising cost and the coming shortage of automotive fuel makes it an object for the automotive industries to improve the fuel economy of automotive vehicles. Several different improvements in the internal combustion engine technology have been made in order to maximize fuel economy. Among these improvements are different injection technologies, different ignition technologies and turbo-charging of the engine. Another improvement used to reduce fuel consumption is the development of an internal combustion engine capable of shutting down some cylinders when the full power of the engine is not needed (e.g., when cruising on a highway) and where all cylinders are used when more power is needed (e.g., when accelerating or climbing).
An engine using this type of technology is often referred to as a Variable Displacement Engine (VDE). In such an engine, the fuel supply is shut off to the cylinders that are to be shut down. At the same time, as the fuel supply is shut off, the intake valves and exhaust valves of these cylinders may be held opened or closed. With closed valves, the engine will perform an internal compression work that will induce so-called NVH (Noise, Vibration, and Harshness) problems. The magnitude of these problems is dependent on the engine speed. At high engine speeds, the NVH problems are less noticeable, so that the closed valve technology can be used at high engine speeds. At low engine speeds, the closed valve technology is impractical. One problem using open valves is that cold air is pumped into the exhaust system, which influences the three-way conversion of the catalyst in a detrimental way.
A further disadvantage with the VDE engine technology is that the pistons of the shut off cylinders still move, together with the connecting rods and the crank shaft, which in turn results in power loss due to internal friction in the engine. Yet another disadvantage with the VDE engine technology is that the torque fluctuations will increase, with a higher maximum peak torque and more zero torque passages, compared with the same engine running on all cylinders.
Different specialized modifications of multi-cylinder internal combustion engines have been disclosed earlier for achieving various results. The use of two or more separate crank shafts to serve some cylinders relative to the remaining cylinders has been described in U.S. Pat. Nos. 4,170,970, 4,470,379, 5,732,668 and 6,205,972. However, said separate crank shafts generally operate synchronously, and not in a selectively alternating manner to accomplish results other than fuel economy. U.S. Pat. No. 7,080,622 discloses a split engine, wherein the divided crank shaft is provided with an overrun clutch arranged between adjacent bearings. U.S. Pat. No. 4,069,803 discloses a split engine with a crank shaft clutch arrangement located between adjacent bearings. The clutch comprises a hydraulically actuated cone clutch with synchronizing teeth.
These solutions may function for some applications, but they still show some disadvantages. One disadvantage is that additional space between adjacent cylinders is required. Thus, there is room for improvement.

Coupling device for split in-line engine


The key obstacle for current resuscitation is the acutely limited time window. The major reason for the limited time window is that the brain and spinal cord are extremely vulnerable to hypoxic-ischemic insult. A method and a lymph-like fluid composition for resuscitation of cardiac arrest are provided. The method includes steps of inhibiting CSF production, removing CSF, replacing the CSF with invented lymph-like fluid composition plus conventional CPR. The lymph-like fluid composition includes polypeptides, insulin, elevated magnesium concentration and ATP in artificial CSF.

1. Field of the Invention
This invention is related to a lymph-like fluid composition and a method of using the composition to protect the brain and spinal cord during resuscitation of cardiac arrest.
2. Background Information
It is estimated that more than 350,000 Americans died of sudden cardiac arrest each year, more than 95 percent of victims die before reaching the hospital. Economic costs for trauma related arrest is over 400 billion dollars each year. Despite numerous scientific advances throughout modern medicine, outcome of resuscitation for arrest victims remains poor. The cardiopulmonary resuscitation (CPR) practice including ventilation, closed chest compressions, open chest cardiac massage and defibrillation (step ABC, i.e. Airway, Breathing and Circulation) was established in the 1960's. This CPR protocol has not taken vulnerability of central nervous system (CNS) into account. Therefore, the key obstacle for current resuscitation is the acutely limited time window, and the major reason for the limited time window is that the CNS is extremely vulnerable to hypoxic-ischemic insult. Traditionally, it is believed that the maximum tolerant survival time for brain in a cardiac arrest patient is about 5 to 8 minutes. Therefore, in clinic, the real problem in circulatory arrest is usually not to restore cardiopulmonary function but instead to prevent brain death.
Shock results in low blood perfusion throughout body. Although the blood perfusion is not completely stopped, shock shares many similar pathological processes with cardiac arrest, and is also a life-threatening condition. Shock can be categorized into anaphylactic, septic, cardiogenic, hypovolemic shock depending on the causes.
The CNS including brain and spinal cord is extremely susceptible to hypoxic-ischemic insults compared with peripheral organ systems such as the liver, kidney, lung, or intestines. The mechanism underlying this susceptibility has not been completely understood. Lacking of an effective approach to protect brain and spinal cord is the ultimate reason why the time window for resuscitation is so limited.
In peripheral tissues, capillaries are relatively permeable and as a result the interstitial fluid (ISF) contains about 2 g/dl of plasma proteins. It is believed that interstitial proteins and hyaluronic acids form a dense network of proteoglycan filaments so that the ISF moves molecule by molecule from one place to another by kinetic motion among proteoglycan filaments in the interstitium. Normally the amount of free-flowing fluid, present in the interstitium is small. A low interstitial protein concentration results in an increased amount of free ISF. An elevated concentration of interstitial protein may reduce the free ISF, but it also attracts more fluid, resulting in increased volume. The lymphatic system is the scavenging pathway for interstitial proteins. By regulating the removal of excess protein, the lymphatic system keeps the interstitial protein concentration around 2 g/dl. This ensures limited free fluid and also regulates the ISF volume. Lymph flow reduces ISF volume resulting in negative interstitial pressure. Therefore, the movement of proteins from plasma to ISF and finally to lymph is important for maintaining extracellular homeostasis.
The CNS lacks a lymphatic system; instead it is bathed by the cerebrospinal fluid (CSF). The CSF is very different from the lymph in peripheral tissues in at least two aspects: protein concentration and the resultant interstitial fluid pressure. The CSF is secreted by the choroid plexuses that line the cerebral ventricles. Tight junctions linking the adjacent choroidal epithelial cells form the blood-CSF barrier and prevent most large molecules from passing into the CSF from the blood. Therefore the CSF contains an extremely low protein concentration. In a human adult, the CSF occupies about 10 percent of the intra-cranial and intra-spinal volume. The average rate of CSF formation is about 21 to 22 ml/hr, or approximately 500 ml/day. The CSF formation is related to intracranial pressure (ICP). When the intracranial pressure is below about 70 mm H20, the CSF is not absorbed, and production increases. Many agents are known as CSF production inhibitors such as Furosemide and Acetazolamide. The choroid plexuses may not be the only sites for CSF production. Milhorat reported that in monkeys with choroid plexuses removed, up to 60% of the CSF is produced from ISF flow out of the brain. The blood-brain barrier (BBB) prevents proteins from entering the interstitium. Therefore, it is speculated that the ISF in brain, just like the CSF, has a low protein concentration. Importantly, the CSF is contiguous with the ISF, with the Virchow-Robin spaces, serving as a conduit. It is estimated that intracellular protein concentration averages about 16 g/dl in mammalian cells. Therefore water and Na+ in the ISF tend to move easily into cells. To make matters worse, the ICP averages about 10 mmHg leading to a positive interstitial fluid pressure. Taken together, these factors make the CNS prone to edema formation. As a result cells in the CNS constantly consume more energy to remove excess intracellular fluid in physiological condition. When cell energy is compromised, such as in ischemia following cardiac arrest, cells rapidly become swollen, i.e. cytotoxic edema.
Swelling of cerebral tissue can compress blood vessels inside the Virchow-Robin space leading to a persistent deficit in blood perfusion even after the restoration of blood perfusion, termed a 'no-reflow' or 'low reflow' phenomenon. This blood perfusion deficit blocks collateral circulation and induces a feedback loop contributing irreversible cerebral cell death and tissue necrosis.
The treatment disclosed in this invention to protect bran and spinal cord is based on the following measures: (1) reducing interstitial pressure in the CNS, and (2) increasing the concentration of water and ion-binding Polypeptides in the CSF.
Lowering the ICP reduces the interstitial pressure of CNS. For example, the CSF drainage to lower the ICP has been used to prevent spinal cord damage caused by cross-clamping aorta during aortic surgery for more than 50 years. Although it is beneficial in most of the cases, the clinical outcomes of this approach, have been inconsistent. This inconsistent result is likely caused by the CSF remained in the folds and chambers of the CNS after general CSF removal. The brain and spinal cord have complex contours with many sulci, gyri and pools. These complicated structures make it impossible to remove the CSF completely even when ICP is reduced to 0 mmHg. Moreover, surface tension and capillary forces retain CSF in the Virchow-Robin space and in the spaces between the dura and brain surface. This invention addresses problem of treating the remaining CSF after general CSF removal.
Researchers have suggested that bolus infusion of hyperoncotic solution into the cerebral vasculature or perfusion of hyperoncotic artificial CSF can alleviate cerebral edema. The term "hyperonconic" refers to high colloid osmotic pressure caused by the existence of large molecular weight substances that do not pass readily across capillary walls. For example, U.S. Pat. No. 6,500,809 to Frazer Glenn discloses a method of treating neural tissue edema using hyperoncotic artificial CSF. Several colloid osmotic agents including albumin and dextran were used in the method.
This invention, however, reveals that the colloid osmotic pressure is not a key factor. Although albumin is effective in protecting the CNS tissue, it appears that its colloid osmotic effect is not the primary reason for its neural protective effect, because other colloid osmotic agents such as Dextran and Hetastarch are ineffective. In contrast, gelatins, even with molecular weights smaller than cut-off size for colloid osmotic agents are effective. In fact, gelatins with various molecular weights ranging from 20,000 to 100,000 Daltons are all effective regardless of their molecular weights. Collagen and Sericin peptides are also effective. Albumin, gelatin, collagen, and Sericin peptides all belong to poly amino acids category. It is thus the water and ions binding properties of proteins or other polyaminoacids that really matter.
The CNS can be made as resistant to various insults as other organ systems, or at least less vulnerable to such insults, by mimicking lymphatic system of other organs. The present invention is also directed at other mechanisms of ischemic injury that are common to all organ systems, including the use of insulin, magnesium and ATP.
The CSF contains about one fifteenth of plasma insulin concentration (CSF: 0-4 μU/ml; fasting plasma: 20-30 μU/ml). Insulin has also been regarded as a growth factor, evidences have repeatedly proven that insulin yield protection for ischemic cerebral tissue independent of its glucose lowering effect. Compared with other growth factors, insulin has been used in clinic for years, and is much less expensive.
Magnesium (Mg2+) is the second highest electrolyte intracellularly (58 mEq/L). ATP (Adenosine 5′-triphosphate) is always present as a magnesium: ATP complex. Mg2+ basically provides stability to ATP. At least more than 260 to 300 enzymes have been found to require Mg2+ for activation. Best known among these are the enzymes involved in phosphorylations and dephosphorylations: ATPases. phosphatases, and kinases for glycolytic pathway and krebs cycles. At the level of the cell membrane Mg2+ is needed for cytoskeletal integrity, the insertion of protein into membranes, the maintenance of bilayer fluidity, binding of intracellular messengers to the membrane, regulation of intracellular Ca2+ release by inositol triphosphate etc. Mg2+ also affects the activities of pumps and channels regulating ion traffic across the cell membrane. The potential changes in tissue Mg2+ might also affect the tissue ATP levels. In tissue culture and animal models elevated Mg2+ concentration has been repeatedly proven to protect neurons and other cells.
The concentration of ATP inside cells is high, whereas the concentration outside cells is very low. Harkness and coworkers showed that the ATP concentrations is about 1 to 20 μmol/l in plasma, however in CSF, ATP could not be detected, and it was estimated to be about less than 0.05 μmol/l. Mufioz and coworkers detected that the ATP concentration in CSF is about 16 nM/l. Exogenous ATP provides direct energy to the damaged tissue. Sakama and coworkers showed that continuous application of ATP (100 μM) significantly increased axonal transport of membrane-bound organelles in anterograde and retrograde directions in cultured neurons. Uridine 5′-triphosphate produced an effect similar to ATP. Mg-ATP has been used clinically in Japan to treat hepatic and kidney hypoxia-ischemia.
Acidosis is a universal response of tissue to ischemia. In the brain, severe acidosis has been linked to worsening of cerebral infarction. Recent evidence however suggests that mild extracellular acidosis protects the brain. It has been reported mild acidosis provide cell protection down to pH 6.2. The acidosis that accompanies ischemia is an important endogenous protective mechanism. Correction of acidosis seems to trigger the injury. It has also been speculated that mild acidosis might stimulate anaerobic glycolysis that might supplement NADH oxidation and ATP yields.

Method and composition for resuscitation


An image forming apparatus is provided. The image forming apparatus includes a photosensitive body unit including a photosensitive body, at least one developing unit including a developing roller that is configured to contact the photosensitive body or to be separated from the photosensitive body, and a press device to press the developing unit in order to contact or separate the photosensitive body and the developing roller to/from each other. The press device includes at least one lever configured to rotate about an end portion thereof and press the developing unit by rotation, and at least one cam configured to allow the lever to rotate by rotation thereof. Since the lever gradually rotates by rotation of the cam, force applied to the developing unit through the lever is also gradually and smoothly increased or decreased. Accordingly, shock, which may occur by rough movement of the developing unit, is remarkably reduced.

1. Field
Embodiments relate to an image forming apparatus having a structure capable of contacting or separating developing rollers and photosensitive bodies to/from each other.
2. Description of the Related Art
An image forming apparatus refers to an apparatus that prints an image on a printing medium according to input signals. An image forming apparatus may be classified as a printer, a copying machine, a fax machine, a multi-function printer that has multiple functions including printing, scanning, copying and faxing, and the like.
An image forming apparatus comprises a photosensitive body unit including a photosensitive body therein, a laser scanning unit to form an electrostatic latent image on the photosensitive body, and a developing unit including a developing roller to form a visible image by supplying developers to the photosensitive body on which an electrostatic latent image is formed.
An image forming apparatus having a structure of supplying developers by contacting a developing roller to a photosensitive body operates such that a developing roller and a photosensitive body contact each other while an image forming process is performed, but are separated from each other to avoid interference therebetween while an image forming process is not being performed.


A switch-mode power supply that includes a transformer coupled to an alternating current (AC) power source and a direct current (DC) power source, wherein the AC power source is electrically isolated from the DC power source. The switch-mode power supply further includes a first controller configured to regulate a first voltage output from the AC power source, and a second controller configured to regulate a second voltage output from the DC power source when the transformer is not receiving power from the AC output.

The subject matter described herein relates generally to electric generators, and more specifically, to methods, systems, and apparatus that enable a switch-mode power supply to have a dual primary transformer that derives a low voltage power supply from two different power sources of disparate voltage ratings.
A switched-mode power supply (SMPS) is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently. Like other power supplies, an SMPS transfers power from a source, like mains power, to a load while converting voltage and current characteristics. An SMPS is usually employed to efficiently provide a regulated output voltage, typically at a level different from an input voltage.
Electronic voltage regulators are used to regulate the output voltage of a brushless synchronous generator by controlling the level of current in an exciter field of the generator. The power source for the excitation is most often derived from a relatively small permanent magnet generator (PMG) that is part of a larger, main generator. However, because a rotor of the PMG is mounted to the same shaft as a rotor of the main generator, it is required that a prime mover of the main generator be rotating in order for the electronic voltage regulator to receive input power. As such, if the prime mover of the main generator is not rotating, the electronic voltage regulator module is unable to perform system monitoring (e.g., temperature monitoring) or perform communication with other system elements because power is not being supplied to the electronic voltage regulator. Thus, the electronic voltage regulator module cannot perform system monitoring nor communication functions until the prime mover begins rotating and power is once again provided to the electronic voltage regulator.

Switch-mode power supply with a dual primary transformer


Embodiments of the present invention include methods and apparatus for circulating fluid through casing and filling the casing with fluid using a combination fill-up and circulating tool while maintaining the fill-up/circulating tool in substantially the same position relative to the casing. In one embodiment, the fill-up/circulating tool includes a mandrel insertable into casing and having a sealing element therearound, the sealing element capable of sealingly engaging with an outer diameter of the mandrel to permit circulating fluid through the casing. The fill-up/circulating tool is also capable of allowing air flow around the outer diameter of the mandrel for the operation of filling the casing with fluid without the need to move the mandrel within the casing.

1. Field of the Invention
Embodiments of the present invention generally relate to running a tubular into a wellbore. More specifically, embodiments of the present invention relate to using a circulating tool for running casing into a wellbore.
2. Description of the Related Art
To obtain hydrocarbons from an earth formation, a wellbore is typically drilled to a first depth using a drill string having a drill bit attached to its lower end. The drill string is then removed, and thereafter a first casing is lowered into the wellbore to line the wellbore. The casing may be a casing section or, in the alternative, a casing string including two or more casing sections threadedly connected to one another. After the first casing is lowered to the first depth, cement is typically circulated into an annulus between the outer diameter of the first casing and the wall of the wellbore to set the first casing within the wellbore.
After setting the first casing within the wellbore, the drill string is re-inserted into the wellbore through a bore of the first casing and used to drill to a second depth within the earth formation. The drill string is again removed, and a second casing is lowered into the wellbore and set therein using cement. This process is repeated with additional casing until casing is installed within the wellbore to the desired depth.
While the casing is being lowered into the wellbore during the "casing running" operation, the pressure within the wellbore is typically higher than the pressure within the bore of the casing. This higher pressure within the wellbore exerts stress on the casing as it is being lowered into the wellbore, risking damage or collapse of the casing during run-in; thus, a casing fill-up operation is performed, where the bore of the casing being run into the wellbore is filled with a fluid (often termed "mud") in an attempt to equalize the pressure inside the casing with the pressure outside the casing (the pressure within the wellbore) and thereby prevent collapse of the casing during the run-in operation. Pressurized fluid is typically input into the bore of the upper end of the casing using a fill line from the existing mud pumps at the well site.
At various times during running of the casing into the wellbore, the casing often sticks within the wellbore. To dislodge the casing from the wellbore, a circulating operation is performed, where pressurized drilling fluid is circulated down the casing and out into the annulus to wash sand or other debris which is causing the casing to stick out from the lower end of the casing. To force pressurized fluid out into the annulus for the circulating operation, a circulating tool is utilized.
To "rig up" the circulating tool for the circulating of fluid through the casing, the circulating tool is inserted into the bore of the casing at the upper end of the casing. A sealing member on the circulating tool is then activated to seal the circulating tool with the casing, forming a path for fluid flow through the circulating tool and out into the bore of the casing. Specifically, in a circulation operation, fluid is introduced into the circulating tool, flows through the bore of the casing and out the lower end of the casing to remove the obstructing debris, and then the fluid having the debris therein flows up the annulus to the surface of the wellbore.
After the circulation operation, the circulating tool is removed from the casing to allow another casing fill-up operation and further running of the casing into the wellbore to occur. During the casing running and fill-up operations, air must be allowed to escape through the bore of the casing to prevent over-pressurizing the bore of the casing. To permit the air being replaced by the fluid during the fill-up operation to escape from the bore of the casing, the circulating tool must be removed from the casing prior to the fill-up operation. To remove the circulating tool ("rig down"), the sealing member is de-activated, and the circulating tool is lifted from the bore of the casing. The casing may then be lowered further into the wellbore while filling the casing with fluid to prevent collapse of the casing.
Rigging up and rigging down the circulating tool, which are time-consuming procedures, must often be performed numerous times during a casing running operation. Therefore, attaching and re-attaching the circulating tool each time the casing is stuck within the wellbore during casing running is expensive and decreases the profitability of the well. Furthermore, because rig personnel perform the rigging up and rigging down of the circulating tool, which are often dangerous operations, numerous rigging up and rigging down operations decrease the safety of the well site.
Thus, there is a need for a method for circulating fluid for a circulating operation and filling up the casing with fluid for casing running and fill-up operations without the need to rig up and rig down the circulating tool every time a circulating operation must be performed. There is a further need for a circulating tool which is capable of performing both the fill-up and circulating operations without removal of the circulating tool from the casing. There is yet a further need for a circulating tool which allows air to escape while maintaining the circulating tool inside the casing during the duration of the casing running operation.

One-position fill-up and circulating tool and method


A polymer comprises at least two types of monomer units selected from: (1) diethynyl benzene units, (2) triethynyl benzene units, and (3) ester units. After curing, the polymer may form a condensed polyaromatic dielectric having a dielectric constant of at most 2.0 at 1 MHz, an elastic modulus of at least 7.7 GPa, and a hardness of at least 2.0 GPa.

Minimization in integrated circuit (IC) dimension allows faster device speed, higher device packing density, and the integration of more functions on a single chip. However, the propagation delays increase with increasing numbers of interconnects, and limits the overall performance of the device. From a materials point of view, in order to lower the propagation delay, higher conductivity metallization and lower dielectric constant (k) materials are required to replace the Al and SiO2/polyimide interconnect structure [1]. Although Cu has successfully replaced Al and become the current metallization material, designing low-k dielectrics remains one of the main challenges today.
Development of low-k materials has lagged behind other areas of semiconductor R&D [2]. As early as 1999, the Internal Technology Roadmap for Semiconductors (ITRS) called for materials having a dielectric constant of 2.2, a goal that was modified several times and ultimately pushed out to 2007 [3]. The reason for this lag is that interlayer dielectric (ILD) materials need to meet stringent material property requirements for successful integration into the structures. These include sufficient mechanical properties to survive chemical mechanical polishing (CMP) processing. Moreover, properties, such as Young's modulus, hardness, and thermal conductivity decrease with increasing porosity, which is used to achieve lower k values [4].
In April 2000, IBM announced its intent to use SiLK™ (Dow Chemical Co.) [5], a spin-on aromatic thermosetting polyphenylene. By 2003, IBM considered abandoning SiLK™, because of its low mechanical properties (Young's modulus of 2.45 GPa and hardness of less than 0.38 GPa [5]) and mismatch in coefficient of thermal expansion with both metal and ceramic substrates [6]. In February 2004, Applied Materials held a press conference to trumpet the use of its Black Diamond™ low-k CVD film by several firms in 90 and 130 nm critical dimension semiconductors [7]. Black Diamond™ is derived from plasma polymerization of siloxane and has a general composition of SiOxCyHz. It has a dielectic constant lower than 2.7, an elastic modulus of 3.5 GPa and a hardness greater than 1.5 GPa. During the conference, Farhad Moghadam pointed out that a key property of the material is the hardness, which is greater than 1.5 GPa. However, the extendability of Black diamond™ to next generation materials (k<2.4) is questionable.
Aromatic polydiacetylenes appeared to be good low-k candidates because they are known to have a relatively low k value, low moisture uptake, excellent thermal stability, and a curing reaction which proceeds without evolving volatiles. Poly(m-diethynyl benzene) (polyDEB) was initially discovered in the early 1960s by Hay and co-workers [11]. The high molecular weight polymer was prepared by the oxidative coupling of m-diethynyl benzene. The polymer undergoes an apparent exothermic decomposition upon heating to 180° C. and showed a weight retention of over 90% after heating to 800° C. under inert conditions [12]. Alternatively, the decomposition observed at 180° C. could have been the result of an uncontrolled exothermic curing process. PolyDEB is an aromatic polydiacetylene, having butadiynylene groups (—C≡C—C≡C—) along the polymer backbone. In 1969, Wegner [13] reported that monomeric diacetylenic single crystals could be polymerized by ultraviolet radiation. This finding suggested that polymers containing diacetylene units would have potential as photoresists.
Poly(p-diethynyl benzene) (polyPEB) typically has high crystallinity and is difficult to dissolve in common solvents. A cured thin film of polyPEB is very brittle [14]. Economy et al. [15–16] developed a highly soluble poly(triethynylbenzene) (polyTEB) as a thermally stable insulating thin film for electronic applications. However, its poor adhesion, huge exotherm during curing, brittleness and high cost limited further applications. TEB oligomers synthesized and formed into films according to their methods broke into small pieces during thermal curing even though the film thickness was below 1 μm. A thinner film (less than 500 nm) could be formed by applying an adhesion promoter. UV pretreatment could be used to further reduce the exotherm during thermal curing. DEB has better solubility and less rigidity than PEB, as well as a lower exotherm and cost compared to TEB. However, its solubility in common organic solvents is still low for use in spin-on coating techniques and it has a tendency to crack prior to curing, resulting in poor film formability [17–18]. Several studies have been carried out to solve the low solubility problem of polyDEB. Stille and Whitesides [19–21] made soluble poly(diacetylene) by incorporating a solubilizing aliphatic side group. Miller et al. [22] synthesized several copolymers containing aromatic diacetylenes and showed the dielectric constants for these polymers were around 2.82 to 3.34 with low moisture uptakes, good film formability and photo definition.

Thermosetting aromatic dielectric material

The Board of Trustees of the Univeristy of Illinois


An apparatus and method for transmitting Uplink Control Information (UCI) over a Physical Uplink Control CHannel (PUCCH) in a communication system. The method includes acquiring information for configuration of a first PUCCH format and a second PUCCH format; generating UCI to be transmitted; selecting one of the first PUCCH format and the second PUCCH format for transmitting the UCI; encoding the generated UCI; performing an Inverse Fourier Transform (IFT) operation on the encoded UCI; and transmitting the IFT performed UCI using the selected PUCCH format. The second PUCCH format is selected, if the transmitting of the UCI is related to multiple downlink carriers.

1. Field of the Invention
The present invention is directed to wireless communication systems and, more particularly, to multiplexing transmissions conveying large payloads of control information from user equipments.
2. Description of the Related Art
A communication system consists of a DownLink (DL), supporting transmissions of signals from a base station (Node B) to User Equipments (UEs), and of an UpLink (UL), supporting transmissions of signals from UEs to the Node B. A UE, also commonly referred to as a terminal or a mobile station, may be fixed or mobile and may be a wireless device, a cellular phone, a personal computer device, etc. A Node B is generally a fixed station and may also be referred to as a Base Transceiver System (BTS), an access point, or some other terminology.
The DL signals consist of data signals, carrying the information content, control signals providing Downlink Control Information (DCI), and Reference Signals (RS) which are also known as pilots. The Node B transmits DCI through a Physical Downlink Control CHannel (PDCCH) and data information through a Physical Downlink Shared CHannel (PDSCH).
The UL signals consist of data signals, carrying the information content, control signals providing Uplink Control Information (UCI), and Reference Signals (RS). The UEs convey UL data signals through a Physical Uplink Shared CHannel (PUSCH). UCI signals include acknowledgement signals associated with the application of a Hybrid Automatic Repeat reQuest (HARQ) process, Service Request (SR) signals, Channel Quality Indicator (CQI) signals, Precoding Matrix Indicator (PMI) signals, and Rank Indicator (RI) signals. The combination of CQI, PMI, and RI will be referred to as Channel State Information (CSI). UCI can be transmitted in a Physical Uplink Control CHannel (PUCCH) or, together with data, in the PUSCH.
The CSI is used to inform the Node B of the channel conditions the UE experiences in the DL in order for the Node B to select the appropriate parameters, such as the Modulation and Coding Scheme (MCS), for the PDCCH or PDSCH transmission to the UE and ensure a desired BLock Error Rate (BLER) for the respective information. The CQI provides a measure of the Signal to Interference and Noise Ratio (SINR) over sub-bands or over the whole operating DL BandWidth (BW), typically in the form of the highest MCS for which a predetermined BLER target can be achieved for a signal transmission by the Node B in the respective BW. The PMI and RI are used to inform the Node B how to combine a signal transmission to the UE from multiple Node B antennas in accordance with the Multiple-Input Multiple-Output (MIMO) principle. Full channel state information in the form of channel coefficients allows the selection of the precoding weights with MIMO to closely match the channel experienced by the UE and offer improved DL performance at the expense of increased UL overhead required to feedback the channel coefficients relative to other CSI signal types.
An exemplary structure for the PUSCH transmission in the UL Transmission Time Interval (TTI), which for simplicity is assumed to consist of one sub-frame, is shown in FIG. 1. The sub-frame 110 includes two slots. Each slot 120 includes NsymbUL symbols used for the transmission of data signals, control signals, or RS. Each symbol 130 further includes a Cyclic Prefix (CP) to mitigate interference due to channel propagation effects. The PUSCH transmission in one slot may be located at the same or at a different part of the operating BW than the PUSCH transmission in the other slot. Some symbols in each slot can be used for RS transmission 140 to provide channel estimation and enable coherent demodulation of the received signal. The transmission BW is assumed to consist of frequency resource units which will be referred to as Physical Resource Blocks (PRBs). Each PRB is further assumed to consist of NscRB sub-carriers, or Resource Elements (REs), and a UE is allocated MPUSCH PRBs 150 for PUSCH transmission for a total of MscPUSCH=MPUSCH·NscRB REs for the PUSCH transmission BW.
An exemplary UE transmitter block diagram for UCI and data transmission in the same PUSCH sub-frame is illustrated in FIG. 2. Coded CQI bits 205 and coded data bits 210 are multiplexed 220. If HARQ-ACK bits also need to be multiplexed, data bits are punctured to accommodate HARQ-ACK bits. Discrete Fourier Transform (DFT) of the combined data bits is performed in DFT unit 230. UCI bits are then obtained by performing sub-carrier mapping in sub-carrier mapping unit 240, wherein the REs corresponding to the assigned transmission BW are selected in control unit 250. Inverse Fast Fourier Transform (IFFT) is performed in the IFFT unit 260. Finally the CP is inserted in CP Insertion unit 270 and filtering is performed in Time Windowing unit 280, which outputs the transmitted signal 290. For brevity, additional transmitter circuitry such as digital-to-analog converter, analog filters, amplifiers, and transmitter antennas are not illustrated. Also, the encoding process for the data bits and the CSI bits, as well as the modulation process for all transmitted bits, are omitted for brevity. The PUSCH signal transmission is assumed to be over clusters of contiguous REs in accordance to the DFT Spread Orthogonal Frequency Multiple Access (DFT-S-OFDM) method allowing signal transmission over one cluster 295A (also known as Single-Carrier Frequency Division Multiple Access (SC-FDMA)), or over multiple non-contiguous clusters of contiguous BW 295B.
The Node B receiver performs the reverse (complementary) operations of the UE transmitter. This is conceptually illustrated in FIG. 3 where the reverse operations of those illustrated in FIG. 2 are performed. After an antenna receives the Radio-Frequency (RF) analog signal and after further processing units (such as filters, amplifiers, frequency down-converters, and analog-to-digital converters) which are not shown for brevity, the received signal 310 is filtered in Time Windowing unit 320 and the CP is removed in CP Removal unit 330. Subsequently, the Node B receiver applies a Fast Fourier Transform (FFT) in FFT unit 340, selects the REs used by the UE transmitter in Sub-Carrier Demapping unit 350, applies an Inverse DFT (IDFT) in IDFT unit 360, extracts the HARQ-ACK bits and places respective erasures for the data bits in Extraction unit 370, and de-multiplexes in Demultiplexer unit 380 the data bits 390 and CSI bits 395. As for the UE transmitter, well known Node B receiver functionalities such as channel estimation, demodulation, and decoding are not shown for brevity.
An exemplary structure for the CSI transmission in one slot of the PUCCH is illustrated in FIG. 4. A similar structure may also be used for the HARQ-ACK transmission in the PUCCH. The transmission in the other slot, which may be at a different part of the operating BW for frequency diversity, is assumed to effectively have the same structure. The CSI signal transmission in the PUCCH is assumed to be in one PRB. The CSI transmission structure 410 comprises the transmission of CSI signals and RS for enabling coherent demodulation of the CSI signals. The CQI bits 420 are modulated in modulators 430 with a "Constant Amplitude Zero Auto-Correlation (CAZAC)" sequence 440, for example with QPSK modulation, which is then transmitted after performing the IFFT operation as it is subsequently described. Each RS 450 is transmitted through the unmodulated CAZAC sequence.
An example of CAZAC sequences is given by Equation (1).
                                          c            k                                          (            n            )                          =                  exp                                [                                                            j2π                                                                                k                                L                                                          (                                  n                  +                                      n                                                                                n                        +                        1                                            2                                                                      )                                      ]                                              (        1        )
In Equation (1), L is the length of the CAZAC sequence, n is the index of an element of the sequence n={0, 1, . . . , L−1}, and k is the index of the sequence. If L is a prime integer, there are L−1 distinct sequences which are defined as k ranges in {0, 1, . . . , L−1}. If the PRBs comprise of an even number of REs, such as for example NscRB=12, CAZAC sequences with even length can be directly generated through computer search for sequences satisfying the CAZAC properties.
FIG. 5 shows an exemplary transmitter structure for a CAZAC sequence that can be used without modulation as RS or with modulation as CSI signal. The frequency-domain version of a computer generated CAZAC sequence, generated in CAZAC Sequence generator 510, is used. The REs corresponding to the assigned PUCCH BW are selected in Control unit 520 for mapping in Sub-Carrier Mapping unit 530 the CAZAC sequence. An IFFT is performed in IFFT unit 540, and a Cyclic Shift (CS), as it is subsequently described, is applied to the output in Cyclic Shift unit 550. Finally, the CP is inserted in CP Insertion unit 560 and filtering is performed in Time Windowing unit 570, which outputs transmitted signal 580. A UE is assumed to apply zero padding in REs used for signal transmission by other UEs and in guard REs (not shown). Moreover, for brevity, additional transmitter circuitry such as digital-to-analog converter, analog filters, amplifiers, and transmitter antennas as they are known in the art, are not shown.
The reverse (complementary) transmitter functions are performed for the reception of the CAZAC sequence. This is conceptually illustrated in FIG. 6 where the reverse operations of those in FIG. 5 apply. An antenna receives RF analog signal and after further processing units (such as filters, amplifiers, frequency down-converters, and analog-to-digital converters) the digital received signal 610 is filtered in Time Windowing unit 620 and the CP is removed in CP Removal unit 630. Subsequently, the CS is restored in the CS Restore unit 640, and a Fast Fourier Transform (FFT) is performed in FFT unit 650. The transmitted REs are selected in Sub-Carrier Demapping unit 660 under control of Control unit 665. FIG. 6 also shows the subsequent correlation in Multiplier 670 with the replica of the CAZAC sequence produced in CAZAC Based Sequence unit 680. Finally, the output 690 is obtained which can then be passed to a channel estimation unit, such as a time-frequency interpolator, in case of a RS, or can to detect the transmitted information, in case the CAZAC sequence is modulated by CSI information bits.
Different CSs of the same CAZAC sequence provide orthogonal CAZAC sequences. Therefore, different CSs of the same CAZAC sequence can be allocated to different UEs in the same PRB for their RS or CSI transmission and achieve orthogonal UE multiplexing. This principle is illustrated in FIG. 7. In order for the multiple CAZAC sequences 710, 730, 750, 770 generated respectively from multiple CSs 720, 740, 760, 780 of the same root CAZAC sequence to be orthogonal, the CS value 790 should exceed the channel propagation delay spread DELTA (including a time uncertainty error and filter spillover effects). If TS is the DFT-S-OFDM symbol duration, the number of such CSs is equal to the mathematical floor of the ratio TS/D.
For the CSI transmission structure in the PUCCH sub-frame, as illustrated in FIG. 4, for one of the two sub-frame slots, 5 symbols carry CSI and 2 symbols carry RS. As the CSI transmission needs to be relatively reliable and cannot utilize HARQ retransmissions, it needs to be protected through reliable channel coding. As a result, the CSI payload supported in the PUCCH is small. For example, puncturing a (32, 10) Reed-Mueller (RM) code to (20, 10), 10 CSI bits can be transmitted using QPSK modulation and coding rate of 1/2 (20 coded bits).
In order to support higher data rates than possible in legacy communication systems, aggregation of multiple Component Carriers (CCs) can be used in both the DL and the UL to provide higher operating BWs. For example, to support communication over 100 MHz, aggregation of five 20 MHz CCs can be used. UEs capable of operating only over a single DL/UL CC pair will be referred to as "Legacy-UEs (L-UEs)" while UEs capable of operating over multiple DL/UL CCs will be referred to as "Advanced-UEs (A-UEs)". The invention assumes that if an A-UE receives PDSCH in multiple DL CCs or transmits PUSCH in multiple UL CCs, a different data packet having its own HARQ process is conveyed by each such PDSCH or PUSCH transmission.
FIG. 8 further illustrates the principle of CC aggregation. An operating DL BW of 100 MHz 810 is constructed by the aggregation of 5 (contiguous, for simplicity) DL CCs, 821, 822, 823, 824, 825, each having a BW of 20 MHz. Similarly, an operating UL BW of 100 MHz 820 is constructed by the aggregation of 5 UL CCs, 831, 832, 833, 834, 835, each having a BW of 20 MHz. Each DL CC is assumed to be uniquely mapped to a UL CC (symmetric CC aggregation) but it is also possible for more than 1 DL CC to be mapped to a single UL CC or for more than 1 UL CC to be mapped to a single DL CC (asymmetric CC aggregation, not shown for brevity). The link between DL CCs and UL CCs can be UE-specific.
To improve cell coverage and increase cell-edge data rates in the DL, Coordinated Multiple Point (CoMP) transmission/reception through Joint Processing (JP) can be used where multiple Node Bs transmit the same data signal to a UE. The DL CoMP principle is illustrated in FIG. 9 wherein two Node Bs, Node B1 910 and Node B2 920, transmit a first data signal to UE1 930 and a second data signal to UE2 940. The Node Bs share the information content for a UE operating in DL CoMP mode through backhaul which is typically referred to as X2 interface 950. The backhaul, for example, may be a fiber optic link or a microwave link.
To support PDSCH reception by an A-UE over multiple DL CCs, the A-UE should be able to transmit substantially larger CSI or HARQ-ACK information payloads to the Node B than an L-UE having PDSCH reception only in a single DL CC. While for symmetric DL/UL CC aggregations UCI transmission may fundamentally appear just as a parallelization of the one for single DL/UL CC pair to multiple DL/UL CC pairs, it is instead preferable for a UE to transmit all UCI in only one UL CC. This allows addressing all possible UE-specific symmetric or asymmetric DL/UL CC aggregations with a single design. It also avoids Transmission Power Control (TPC) problems that may occur if the UE simultaneously transmits UCI signals with substantially different powers in different UL CCs. Therefore, it is advantageous to consider UCI signaling structures where the transmission is in a single UL CC. This further necessitates the transmission of larger UCI payloads, than legacy ones, in a single channel.
DL CoMP also represents a challenging scenario with respect to required payloads of CSI feedback signaling. Even for the benign case of CQI-only feedback, the respective payload increases proportionally with the number of Node Bs in the CoMP CSI reporting set. For example, for 3 Node Bs in the CoMP CSI reporting set, the total CSI payload is 30 bits and cannot be supported by the PUCCH structure in FIG. 4. Since a CoMP UE is often likely to also experience low UL SINR, supporting higher CSI payloads becomes even more challenging. The combination of CoMP and multiple DL CCs further increases the required CSI payloads.
The PUSCH can support substantially larger payloads than the PUCCH and can accommodate the increased UCI payloads. However, as the minimum PUSCH granularity is 1 PRB, the UL overhead from using conventional PUSCH to support only UCI transmissions can become substantial even when this is done for a few UEs per sub-frame.
Therefore, there is a need to design PUCCH structures supporting large payloads for UCI signaling in a communication system supporting DL CC aggregation or DL CoMP.
There is another need to minimize the UL overhead corresponding to the transmission of large UCI payloads.
Finally, there is a need to efficiently manage the PUCCH and PUSCH resources while supporting the transmission of large UCI payloads.

Multiplexing large payloads of control information from user equipments