The present invention is a method and apparatus for readmitting air into vacuum containers, such as canning jars, by incorporating a flexibly-mounted check valve in the container lid or body, and sandwiching an elastomeric seal member, such as an O Ring, between the check valve and the vacuum container's lid or wall. The check valve is flexibly mounted to the airtight container by a retainer member that permits the check valve to move vertically and horizontally and compresses the elastomeric seal member sufficiently to prevent leakage. Air is readmitted into the vacuum container by applying a force to the check valve that sufficiently decompresses a segment of the elastomeric seal member to cause leakage. The displacement force on the check valve may be applied by hand, without using any tools.

People vacuum pack their foods to either retain fresh flavor or preserve food that would otherwise be thrown out. As such, the amortized cost of vacuum packing apparatus must be less than the cost of the food that users are trying to preserve. Further, the net savings must outweigh the inconvenience and time it takes to perform the vacuum packing operation. These economic factors dictate that vacuum packing systems be inexpensive and easy to operate. Further, they should be sufficiently compact to conveniently fit in crowded kitchens. Finally, vacuum packing systems must be reliable and consistently retain vacuums for extended periods.
With the exception of hermetic seals, all seals leak —it's just a matter of how slowly they leak. However, using appropriate materials with compatible lubricants, and applying sufficient sealing pressure, the leakage rate can be controlled to a level acceptable for the particular application.
Although the prior art is replete with simple and reliable mechanisms for evacuating air from containers, it contains few instances of simple and reliable mechanisms for readmitting air into vacuum containers. All air evacuation systems involve some sort of check valve —a generic term for a device that only allows fluids to flow in one direction. In contrast, air reentry systems can readmit air either through the same check valve that exhausted it (internal to the check valve), or through a path external to the check valve. The latter approach is inherently more reliable because making a check valve work in both directions compromises its effectiveness in at least one of the two directions. Further, bi-direction check valves generally require additional mechanisms that make them more complex and more expensive.
The internal and external are reentry approaches are illustrated in the sample of prior art examined in the following paragraphs. The internal air reentry approach embodied in U.S. Pat. No. 4,142,645 by Walton is simple, but cannot work as described. Walton discloses a check valve consisting of a ball 34 residing in an elastomeric nipple 32 featuring a conical bore 42, and a valve seat 44 having a relatively small slant angle of approximately 5 degrees. A major issue with the Walton device is the plausible impossible approach for readmitting air. Walton postulates that "pinching the nipple 32 immediately below the level of the ball 34" will deform the valve seat 44 into an elliptical or oval shape in transverse cross section, thereby creating an air reentry path between the ball and the elastic tube. See FIG. 5. This postulate is false. Although pressing on a hollow plastic tube will certainly flatten it out, pressing on a plastic tube containing a snugly-fitting ball 34 will not. This is because the ball 34 prevents diametric contraction of the tube in the vicinity of the ball, and diametric contraction in one direction must occur for the tube to expand in the perpendicular direction. Thus the circular tube cross section will remain circular, and the tube will simply compress tighter around the ball 34. Although an artist can easily draw a ball positioned in an oval-shaped cross section (FIG. 5), no such oval can be physically realized until the ball 34 is pushed out of intimate contact with the nipple 32. Pressing sufficiently hard on the elastomeric tube can generate axial forces on the ball 34 that act to move the ball 34 up the tube. However, such axial forces will be resisted by atmospheric pressure as well as frictional forces between the nipple 32 and the ball 34 that are especially large if the nipple 32 has a small slant angle. Grossly compressing the nipple 32 can force the ball 34 into a larger conical section of the nipple 32, but such compression can also pinch the tube completely closed, shutting off the air reentry path. Hence, Walton failed to disclose a combination of geometries and material properties of the nipple 32 and ball 34 that would allow the proposed air reentry method to work as postulated.
U.S. Pat. No. 6,619,493 B2 by Yang is another example of a two-way check valve that readmits air through a path internal to the check valve. The Yang approach is sound mechanically, but overly complex. Yang's approach consists of a curved diaphragm called a membrane piece 41 that rests atop a plurality of air holes 403 that lead to the inside of the container body 2. Drawing a vacuum causes the membrane piece 41 to lift and allow air to flow out of the container body 2 and through the suction hole 32. The membrane piece 41 has an integral pull rod 412 that is lifted upward by pressing on a push button 34 attached to the top of the cover 3. Lifting the pull rod 412 upward unseats the membrane piece 41 allowing air to re-enter the container body 2. The Yang apparatus for readmitting air will work, but consists of at least nine custom made parts, thereby increasing both complexity and cost. Further the housing 40 must be bonded air tight to the cover 3, and Yan mentions using a high-frequency welding machine to create such a bond. Hence the complexity and special manufacturing operations drive up cost and thereby diminish the value to would-be users.
U.S. Pat. No. 5,405,038 by Chuang is another example of a two-way check valve that readmits air through a path internal to the check valve. The silicon piece 26 is a diaphragm that naturally opens upward during the air evacuation phase. For the air reentry phase, the user presses on a separate T-shaped button 27 that forces the center of the silicon piece 26 down and its edges up, thereby creating an air leakage path. Once again, the need for a number of additional ancillary components, plus their associated assembly operations, adds complexity and cost to the air reentry mechanism.
U.S. Pat. No. 6,131,753 by Lynch is an example of an air re-entry mechanism that is external to the check valve. The air re-entry path is via a center valve opening 34. A spring 108 forces a ball 106 against the center valve opening 34, thereby keeping it closed when the container is under vacuum. The vacuum is released by pulling up on a cable 112 that has one end attached to the ball 106 and the other end attached to a pull ring 104. Lynch's valve relief assembly 100 consists of at least six different custom parts that must be manufactured and assembled to accomplish the air reentry task. Thus the Lynch device suffers from the same inherent cost penalty as the Yang device.
Air reentry systems must retain vacuums when the air reentry mechanisms are not in operation. Hence, a designer needs a quantitative understanding of how an air reentry system must be designed to preserve a vacuum. A commonly used method for retaining vacuums is to use elastomeric seals. However, to effectively retain a vacuum, the elastomeric seal member must be compressed sufficiently to limit leakage to an acceptable rate. More specifically, the elastomeric seal member must be lubricated and compressed sufficiently, in terms of pounds per linear inch, depending on the material properties of the elastomeric sealing material and the acceptable leak rate. For example, O Rings used as face compression seals typically have a Shore A Hardness of 70 (which represents a compromise between compressibility and durability). Face compression O Rings must be compressed between 20% and 30% to produce a sufficient load, measured in pounds per liner inch, to create long-lasting seals. For an O Ring having a Shore A Hardness 70, and a cross sectional diameter of 0.103 inches, the minimum recommended compression load is approximately 10.3 pounds per linear inch. Accordingly, for a standard AS568A-107 O Ring, that has a mean diameter of 0.309 inches, the total force required to achieve 10.3 pounds per linear inch is 9.99 pounds. This load can be generated by a combination of atmospheric pressure and force applied to the check valve for on external source. In the case of the AS568A-107 O Ring, the maximum load obtainable from atmospheric pressure is 1.1 pounds. This means that 8.9 additional pounds must be applied to the O Ring. This may be done with a spring-like mechanism that anchors the assembly together. This disclosure refers to such a spring-like anchor element as a retainer member. Thus, in the general case, the minimum number of parts to evacuate air from a container using an off-the-shelf check valve is three: a check valve, an elastomeric seal member, and a spring-like retainer member. The objective of this invention is to implement the vacuum release (air re-entry) mechanism with such a minimum number of parts.
Air may be readmitted into a vacuum container outfitted with a check valve and elastomeric seal member in one of three ways. The first way is to install a completely separate mechanism that may be opened and closed, such as a plug that fits into a valve or hole. This method is straight forward but requires two additional parts. A second method is to pull up on the check valve with sufficient force to unseat the elastomeric seal member. There are several disadvantages of this approach. First, a relatively high pulling load is required for even a small elastomeric seal member. For example, as already noted, the AS568A-107 O Ring requires a pre-load of approximately 9 pounds to retain a vacuum, and overcoming this large a force may be difficult for some users. A second disadvantage is the high pulling force may damage the retainer member, check valve, or the container lid. Finally, the check valve might have to be outfitted with a loop or some other pulling device to allow users to get a sufficiently strong grip on the check valve.
A third approach is not to unseat the elastomeric seal member at all, but rather lower the compressive load over a segment of the elastomer seal to allow air to leak between the elastomeric seal member and the container lid or container wall. This is the preferred approach and the one disclosed herein. This approach can be implemented by applying a lateral load to the side of the check valve. Doing so causes the check valve to tilt away from the applied load, thereby increasing compression on the opposite side of the elastomeric seal member, and decreasing compression on the side of the elastomeric seal member where the load is applied. The advantage of this approach is that it requires no additional parts. The only requirements are (1) the elastomeric seal member be sufficiently thick, and the check valve diameter be sufficiently small, to allow the check valve to tilt enough to greatly relieve the pressure on a segment of the elastomer seal, and (2) the retainer member be flexible enough to permit such movement. For example, for an AS568A-107 O Ring having a 0.103 inch thick uncompressed cross section and a 0.309 inch mean diameter, the check valve would have to be free to tilt approximately 7.6 degrees to decompress one segment of the O Ring. Accordingly, the check valve diameter must be small enough not to contact the lid when the check valve is tilted 7.6 degrees, and the retainer member must allow such a range of motion.
Prior art has not considered selectively lowering the contact pressure on one segment of an elastomeric seal member to allow air to leak past the elastomeric seal member. This is because elastomeric seal members such as O Rings are primarily intended to prevent fluid flow, not enhance it. In those instances of the prior art wherein an elastomeric seal member had to act as a switch, allowing fluid to flow past it on command, the conventional practice was to completely unseat the elastomeric seal member by disengaging it from the mating part.
In summary, a reliable and cost-effective method is needed for readmitting air into vacuum containers. The ideal method would not require a separate plug, cover, or any other ancillary part to prevent air from re-entering the vacuumed container. Such a method and apparatus are disclosed in the present invention. The present invention addresses the complexity and cost issues of prior art by devising an air re-entry system that consists of only three parts. Further, all three parts are commonly available, off-the-shelf components that can be supplied by multiple vendors. This not only avoids investments in custom manufacturing tooling, but also allows the present invention to benefit from economies of scale associated with off-the-shelf parts.

Method and apparatus for readmitting air into airtight containers


A water jet propulsion assembly for a jet ski-type watercraft includes an annular duct including a first section within which an impeller is located, a second section having a group of sloping vane members extending radially therethrough and a third section formed with a group of straight vane member extending partially radially inwardly from the inside surface of the outermost duct wall. The duct terminates in a nozzle for expelling water flowing therethrough. The second section of the duct includes radially inner and outer wall portions and the inner portion has a cap member secured to a rear end thereof. The cap member extends into the third duct section and is formed with another group of straight vane member which extend radially outwardly. The vane members function to convert the swirling water flow created by the impeller into a linear flow that is directed through the nozzle. The sloping and straight vane members are divided to permit more efficient molding of the vane sections by die casting.

1. Field of the Invention
The present invention pertains to a water jet propulsion assembly and, more particularly, a stationary vane arrangement for directing the pressurized flow of water from an impeller of a water jet propulsion unit.
2. Discussion of the Prior Art
A jet ski-type watercraft utilizes a water jet propulsion unit located in a concave area formed in a lower, stern portion of the watercraft to propel the watercraft. As shown in FIG. 1, a typical prior art water jet propulsion unit draws water in through an opening 38A formed in the hull of the boat. This water is pressurized by an impeller 30A which is rotated by an engine (not shown) through a shaft 16A. The pressurized water is then expelled rearward through a nozzle 40A. A duct structure 26A defined by an outer duct tube 20A and an inner duct tube 24A defines a water passage 36A for the pressurized water flowing toward nozzle 40A. Stationary vanes 23A, formed integral with duct 26A and extending radially inward therefrom, function to convert the swirling water flow from impeller 30A to a linear flow and to direct the water to nozzle 40A.
In order for stationary vanes 23A to be able to convert the swirling water flow into a linear flow, stationary vanes 23A must be colinear with the axial direction of drive shaft 16A. As best shown in FIG. 3, which is a cross-sectional view taken along line III--III of the stationary vane 23A shown in FIG. 2, each stationary vane 23A comprises a sloping portion 50A and a straight portion 52A. Sloping portion 50A comprising roughly half the length of vane 23A, is located on the impeller side of duct 26A and slopes in a direction opposite that of impeller 30A. Straight portion 52A of stationary vane 23A extends axially toward the nozzle end of duct 26A. This type of duct arrangement for a jet ski-type watercraft is exemplified by Japan Patent Sho 60-30599.
In this known jet ski propulsion arrangement, duct 26 A, along with stationary vanes 23A, is produced by aluminum die casting in order to improve productivity and to reduce manufacturing costs. However, since the stationary vanes 23A have sloping portions 50A, the fabrication has to be accomplished using a split mold, as depicted at 80A, 82A in FIG. 3, in order to cast duct 26A having stationary vanes 23A. This makes it necessary for each of the mold pieces to be removed in the directions of arrows 70A, 72A of FIG. 3. However, when stationary vanes 23A are made relatively long, the mold removal distance lengthens correspondingly. When this is done, as shown in FIGS. 2 and 4, a step 60B is formed on the outside circumference of the inner duct tube 24A along with a step 60A on the inside circumference of outer duct tube 20A. These steps 60A, 60B formed at the junction of the mold sections tend to disturb the water flow by creating turbulents and decrease the propulsion efficiency of the water jet propulsion unit.
Therefore, there exists a need in the art for a water jet propulsion assembly which can be die casted with minimal step differentials and which includes a water flow duct having radial vanes which enables a generally linear flow of water through the duct so as to increase the efficiency of the propulsion assembly.

Vane arrangement for a water jet propulsion assembly


A method and mechanism for producing and executing self-steering program code. A method comprises analyzing program code and identifying portions which may be amenable to optimization. Having identified such a portion of code, at least one optimized version of the identified code is added to the program code. Additionally, a selection mechanism is added to the program code which is configured to select between two or more versions of the portion of code during runtime. The modified program code is then compiled with the added optimized version and the selection mechanism. During execution, monitoring of behavior of the code may be enabled or disabled. Based upon such monitored behavior, a different version of the code may be selected for execution. Various optimized versions may be selected for execution in a manner which takes advantage of the current behavior of the program.

1. Field of the Invention
The invention relates to computing systems and, more particularly, to multithreaded processing systems.
2. Description of the Related Art
Modern optimizing compilers have the ability to do a large number of complex optimizations. Some types of optimization are universal and may improve performance in virtually all cases. However, in other cases, the benefit of optimizations, or the manner in which they need to be applied for maximum benefit, depends on the target program's behavior. In order to address optimizations that may depend on a target program's behavior, various approaches have been used.
One approach that has been used to optimize code in view of a program's behavior is "static analysis". FIG. 1 depicts one embodiment of the static analysis approach. Using this approach, a source program (block 100) is created. The compiler analyzes the program to determine its behavior and optimizes accordingly (block 110). During the analysis, the compiler determines or guesses at program behavior and makes optimizations. Finally, an optimized executable is produced (block 120). This approach may be relatively easy for the user compared to some other approaches, but is limited in applicability because static analysis generally cannot accurately determine program behavior in many cases. Therefore, optimization opportunities may not be fully exploited.
FIG. 2 depicts another compiler optimization approach sometimes utilized that is referred to as "profile feedback". The profile feedback approach acknowledges some of the deficiencies of the static analysis approach, and utilizes a "training run" to learn about a target program's behavior. Using this approach, developers build a training version of a program. As shown in FIG. 2, a source program is provided (block 200) and compiled (block 210). The resulting executable is built for the sole purpose of training. Training runs are then performed (block 220) using training inputs (block 230). After training, the source code is re-built (block 240) and a new executable created (block 250) which is optimized based upon the training runs. While a training run may help the compiler learn about the program's behavior, the build process requires extra steps. For this reason, many developers avoid profile feedback. In addition, training input might not represent actual input. Further, optimizations are fixed in the final executable and do not adapt to variations in program behavior.
Yet another approach used for optimizing program code is "run time optimization". Using the run time optimization approach, a program's behavior is monitored during runtime. Based upon the observed behavior, code may be optimized and re-optimized as desired. FIG. 3 illustrates one embodiment of this approach. As shown, a source program (block 300) is compiled (block 310) and training runs may be performed (block 320). Such training runs may utilize training input (block 330). Finally, an executable is produced (block 340). During runtime (block 350), a monitor (block 360) is utilized to monitor the execution. Based upon this runtime monitoring, the code may be re-compiled (block 370) in an effort to further optimize the code. Re-compilation produces a new executable (block 340). The process (350, 360, 370) may then be repeated as desired.
In this run time optimization approach, the original executable may be built with a traditional compiler. While the run time optimization approach may provide for some adaptability during runtime, it does have some drawbacks. For example, monitoring introduces additional overhead. Further, because run time optimization is designed to work on any executable, it doesn't know what parts to monitor for a given behavior in an executable. Consequently, it may end up monitoring many things in many places that are not particularly relevant. Still further, re-compilation is very complex and resource-hungry. Another potential problem for run time optimization is that certified code may be modified during execution. Consequently, the executable can no longer be trustworthy. For these and other reasons, traditional run time optimization may not be desirable.
In view of the above, effective methods and mechanisms for improving code optimization are desired.

Adaptive code through self steered execution


A method of forming a memory device (and the resulting device) by forming an electron trapping dielectric material over a substrate, forming conductive material over the dielectric material, forming a spacer of material over the conductive material, removing portions of the dielectric material and the conductive material to form segments thereof disposed underneath the spacer of material, forming first and second spaced-apart regions in the substrate having a second conductivity type different from that of the substrate, with a channel region extending between the first and second regions, with the segments of the dielectric and first conductive materials being disposed over a first portion of the channel region for controlling a conductivity thereof, and forming a second conductive material over and insulated from a second portion of the channel region for controlling a conductivity thereof.

An NROM device is a nonvolatile read-only memory electronic memory device which stores charges in a dielectric layer and is well-known in the art. Referring to FIG. 1, there is shown a cross-sectional view of an NROM device 1 of the prior art. The device 1 is made on a silicon substrate 2 with a first conductivity type, and with first and second regions 3/4 spaced apart from one another which are of a second conductivity type different from the first conductivity type of the silicon substrate 2. Separating the first region 3 from the second region 4 is a channel region 5. A first insulating layer 6 such as silicon oxide or silicon dioxide is formed over the channel region 5. A dielectric 7, such as silicon nitride, is positioned over the silicon dioxide layer 6. A second insulating layer 8 such as another layer of silicon dioxide is positioned over the dielectric 7. Collectively, the first insulating layer 6, the dielectric layer 7 and the second insulating layer 8 are also known as an ONO layer 6–8. Finally, a polysilicon gate 9 is positioned on the second layer silicon dioxide 8. Thus, the dielectric 7 is spaced apart and is insulated from the channel region 5 via the first insulating layer 6. The polysilicon gate 9 is insulated and separated from the dielectric 7 by the second insulating layer of silicon dioxide 8. In summary, the polysilicon gate 9 is spaced apart and separated from the channel region 5 by the ONO layer 6–8.
The NROM device 1 is a double density, nonvolatile storage cell, capable of storing 2 bits of information in the cell. The polysilicon layer 9 serves as the gate and controls the flow of current between the first region 3 and the second region 4 through the channel region 5. To program one of the bits, the polysilicon gate 9 is raised to a high positive voltage. The first region 3 is held at or near ground and the second region 4 is raised to a high positive voltage. Electrons from the first region 3 accelerate into the channel 5 towards the second region 4 and through hot channel electron injection mechanism are injected through the first oxide layer 6 and are trapped in the dielectric 7 near the region 10 of the dielectric layer 7. Since the dielectric layer 7, comprising of silicon nitride is a nonconductive material, the charges are trapped in the region 10.
To program the other bit of the cell 1, the polysilicon layer 9 is raised to a high positive voltage. The second region 4 is held at or near ground and the first region 3 is raised to a high positive voltage. Electrons from the second region 4 accelerate in the channel 5 towards the first region 3 and through hot channel electron injection mechanism are injected through the first silicon dioxide layer 6 and are trapped in the region 11 of the dielectric layer 7. Again, since the silicon nitride layer 7 is nonconductive, the charges are trapped in the region 11.
To read one of the bits, the first region 3 is held near ground. A positive bias voltage is applied to the polysilicon layer 9. The voltage applied is such that if the region 11 does not contain trapped charges (i.e. is not programmed), it will cause the channel region 5 underneath it to be conductive. However, if the region 11 has trapped charges (i.e. is programmed), the channel region 5 underneath will not be conductive (not be turned on). A positive voltage is also applied to the second region 4. The voltage applied to the second region 4 is such that it causes a depletion region of the second region 4 to expand and encroach the channel region 5 so that it extends beyond the region 10. Thus, the state of whether region 10 is programmed or not is irrelevant in reading region 11 of the memory cell. Therefore, under that condition, the state of conduction of the channel 5 between the first region 3 and the second region 4 is dependent solely on the state of charge stored or trapped in the region 11.
To read the other bit, the voltages applied are simply reversed. Thus, the second region 4 is held near ground. A positive bias voltage is applied to the polysilicon layer 9. The voltage applied is such that if region 10 is not programmed, it will cause the channel region 5 underneath it to be conductive. However, if region 10 is programmed, channel region 5 underneath will not be conductive (not be turned on). A positive voltage is also applied to the first region 3. The voltage applied to first region 3 is such that it causes the depletion region of the first region 3 to expand and encroach into the channel region 5 beyond region 11 so that the state of charge stored or trapped in region 11 is irrelevant in reading region 10 of the memory cell.
To erase, the substrate 2, the first region 3, and the second region 4, may be connected to a high positive voltage thereby causing electrons from the trapped regions 10 and 11 to tunnel via Fowler/Nordheim tunneling into the substrate 2.
The problem with the NROM cell 1 of the prior art is that the channel 5 is on the planar surface of the silicon substrate 2, and channel region 5 needs to be sufficiently large so that the two trapped regions 10 and 11 are sufficiently separated. This becomes a problem as the cell 1 is scaled to smaller sizes, especially since the thickness of the ONO layers 6–8 cannot be scaled.
FIG. 2 illustrates another prior art design of a NROM device which stores charges in a dielectric layer, with a split gate memory cell configuration. Here, oxide and nitride layers 6–7, along with a memory gate electrode 8, are disposed over only a first section of the channel region 5. Also, the polysilicon gate 9 has a lower portion that is disposed over and insulated from a second section of the channel region 5 (via insulation material 12), and a second portion that extends up and over oxide 6, nitride 7 and memory gate 8. Electrical contacts 13 and 14 are formed to make electrical contact with first and second regions 3/4. With this configuration, only a single bit of information is stored by programming nitride layer 7 with trapped electrons, in the same manner as described above. The problem with this design is that is can be difficult to scale down in size. Specifically, the effective channel length needs to be long enough to tolerate different lithographic steps used to form the separate poly gate 9 and oxide 6/nitride 7/gate 8. Further, the width of the oxide/nitride/gate 6/7/8 is at least one lithographic feature length long, which is unnecessarily long given that the trapped charges are immobile within the dielectric material.
There is a need for an improved method of forming an electron trapping NROM device that allows the device to scale down further in size than conventional designs allow.


A gas turbine installation includes at least one gas turbine. A transition piece may receive an exhaust gas from the gas turbine. The transition piece is an exhaust gas inlet part of a steam recovery part for a steam generator. The transition piece includes a chimney orifice for discharging the exhaust gas of the gas turbine.

In a gas turbine installation, while it is in operation, exhaust gas has to be extracted from the gas turbine and discharged. It is necessary, as a rule, to erect a special chimney for this purpose.
A chimney of this kind is also necessary, and has to be erected separately, when the gas turbine installation is extended by way of a steam generator to form a gas and steam turbine installation (combined-cycle installation). Here, the exhaust gas from the gas turbine is utilized for the generation of steam to be used by the steam turbine. A chimney is also necessary when gas turbine operation is desired, even before the completion of the entire combined-cycle installation ("preferential gas turbine operation").
A bypass chimney, as it is known, is erected and used for the discharge of the exhaust gas from the gas turbine, at least until the components relating to the steam turbine are installed and ready for operation. Once the combined-cycle installation is completed, the exhaust gas from the gas turbine can be introduced into a waste-heat steam generator, thereby obviating the need for the bypass chimney. The erection of a bypass chimney of this kind and its possible dismantling after the completion of the combined-cycle installation are complicated.

Gas turbine plant with an exhaust gas chimney


A method for combating malicious programs including monitoring network traffic from one or more devices, analyzing the network traffic to determine the presence of a malicious program in the one or more devices and disabling transmission of the network traffic for those of the one or more devices determined to have the malicious program present.

1. Technical Field
The present disclosure relates to security and, more specifically, to systems and methods of computer security.
2. Description of the Related Art
In today's highly computer dependant environment, computer security is a major concern. The security of computer networks is routinely threatened by computer viruses, Trojan horses, worms and the like. Once computer networks are infected with these malicious programs, the malicious programs may have the ability to damage expensive computer hardware, destroy valuable data, tie up limited computing resources or compromise the security of sensitive information.
Worms can be a particularly catastrophic form of malicious program. Worms can infect a computer network and quickly commandeer network resources to aid in the worm's further propagation. In many cases malicious code, for example worms, propagates so rapidly that network bandwidth can become nearly fully consumed. This consumption of bandwidth can grind network function to a near complete halt threatening the proper function of critical applications. Such a network slowdown can have severe adverse effects even on network systems that are not themselves infected with the malicious program.
After a worm has infected computers and computer networks a destructive payload can then be delivered. Destructive payloads can have many harmful consequences, for example, valuable hardware and/or data can be destroyed, sensitive information can be compromised and network security measures can be circumvented.
To guard against the risk of malicious programs such as worms, businesses may often employ antivirus programs, intrusion detection systems and intrusion protection systems. Antivirus programs are computer programs that can scan computer systems to detect malicious computer code embedded within infected computer files. Malicious code can then be removed from infected files, the infected files may be quarantined or the infected file may be deleted from the computer system. Intrusion detection systems and intrusion protection systems (IDSs) are systems that can be implemented on a computer network that monitor the computer network to detect anomalous traffic that can be indicative of a potential problem, for example a worm infection. IDSs may be either active or passive. Active IDSs may take affirmative measures to remedy a potential infection when found while passive IDSs may be used to alert a network administrator of the potential problem.
IDSs often attempt to identify the presence of network infection by analyzing packets of data that are communicated over the network. Packets are generally examined and compared with signatures of known malicious programs. When a signature matches a packet, the packet may be indicative of a malicious program infection.
IDSs that rely on signatures for the detection of malicious programs must regularly receive and install updated signatures corresponding newly discovered malicious programs. If no signature has been received and installed for a particular malicious program, the IDS might not be able to identify the malicious program.
Modern malicious programs such as worms are able to spread very quickly from computer network to computer network throughout the world. Unfortunately, they can spread so quickly that they can infect many networks before a signature for detecting the malicious program can be developed, distributed and installed.
It is desired that a method and system be used that can slow down the propagation of malicious programs until a suitable signature can be obtained to combat the malicious program. By slowing down the propagation of malicious programs, it is possible that further infection can be limited and network bandwidth can be maintained.

Intrusion detection based on amount of network traffic


A sorting conveyor for transporting objects and unloading objects at one or more unloading stations adjacent the conveyor. Each of the tilting conveyor carts includes a trailer frame base, a carrying tray for holding the objects and a tiltable support apparatus for supporting the carrying tray above the trailer frame base and for allowing tilting of the carrying tray towards at least one side of the conveyor to unload objects into unloading stations on at least one side of the conveyor.

(1) Field of the Invention
The present invention relates generally to package sorting conveyors and more particularly relates to an improved tilting mechanism for a tilting conveyor cart.
(2) Description of the Related Art
Conveyor systems having a number of individual carrying carts have been commonly used for many years to carry and sort packages or other items, such as mail. For example, U.S. Pat. No. 5,054,601 to Sjogren et al. discloses a package sorting conveyor comprised of a train of tilt tray carriers coupled in tandem to form a continuous loop. Each carrier includes a pivotally mounted tilt tray normally maintained in an upright position. The carriers are moved around the loop by a series of motors spaced around the loop. Branching out from the loop are outfeed chutes or the like for receiving packages from the carriers. When a particular carrier holding a particular package to be sorted reaches a selected outfeed chute, an actuator tilts the tray to dump the package into the outfeed chute. Another example of a typical package sorting conveyor is disclosed in International PCT Application Number PCT/DK90/00047 of Kosan Crisplant A/S.
One significant disadvantage of conventionally designed package sorting conveyors is that conventional conveyor carriers laterally tilt only on a horizontal axis parallel to the direction of conveyor travel. While this accomplishes the objective of dumping the package from the carrier into an outfeed chute or the like, the package is often roughly tumbled or rolled, sometimes damaging the package's contents. One reason for this is that the packages typically are unloaded from the carrier while still traveling forward at the same speed as the conveyor. Thus, packages tend to slam into a forward retaining wall of the outfeed chute before sliding down the chute. Another problem with conventional laterally tilting conveyors is that because the packages are moving forward at full speed when they are unloaded into the outfeed chute, the outfeed chute must be relatively wide so that packages do not miss the chute and fall off the conveyor past the chute. This often unnecessarily increases the overall size of the conveyor system.
U.S. Pat. No. 4,744,454 and an improvement thereto, U.S. Pat. No. 5,086,905, both to Polling, disclose previous attempts to remedy this problem of rough handling by conventional laterally tilting conveyor carriers. Both of these patents to Polling disclose a conveyor element for a package conveyor that includes a tilting carrier tray mounted to be rotatable about two swivel axes. A first swivel shaft extends obliquely downward from the underside of the carrying tray and is in turn connected at an angle to the end of a second swivel shaft extending obliquely upwards from a base support part of the conveyor element. Together, the two swivel shafts form a "V" that points in the direction of conveyor travel. Both of the swivel shafts lie in the vertical plane of symmetry of the conveyor element when the carrier tray is disposed in its upright position.
Because the carrier tray of Polling rotates about two oblique axes, the carrier tray can be tilted not only lateral on a horizontal axis, but is moved through a geometrically complex spatial reorientation during package discharge. This allows for more gentle placement of a package on an outfeed chute than can be accomplished using conventional conveyor trays that laterally tip on only a horizontal axis. The Polling conveyor element more gently handles the packages by imparting some degree of rearward velocity to the packages as they are discharged, which, when added to the forward velocity of the conveyor system, results in the packages' forward velocity during discharge being less than that of the conveyor system itself.
However, the conveyor elements of both of Polling's patents are unduly complicated and intolerant of manufacturing discrepancies. In fact, the second Polling conveyor element (U.S. Pat. No. 5,086,905) was invented in an attempt to simplify the original design disclosed in the first Polling patent (U.S. Pat. No. 4,744,454), which had proved to be too expensive and complicated to manufacture efficiently. As a result of this complexity and cost, the Polling devices have not enjoyed significant commercial acceptance and success.
One solution to these problems is shown in U.S. application Ser. No. 08/632,012, filed Apr. 15, 1996, which is hereby incorporated by reference in its entirety. One feature of this reference is the use of a pull-down design for tilting the improve trays.
Another example of a sorter conveyor using a pull-down design for tilting its trays is shown in U.S. Pat. No. 5,664,660, issued to Prydtz. The '660 patent is directed to a sorter conveyor having laterally tiltable transport trays, instead of a conventional transport chain driven by a driving station, in which a driving wheel or worm cooperates with the chain links, these being advanced arranged with guiding rails along a small mutual spacing and carrying both the transport trays and the tilt mechanisms associated therewith, which conventional arrangement causes considerable problems with respect to tolerances for both the longitudinal pitch of the chain links and the mounting of the guiding rails. The invention includes carts that are advanced along mutually widely spaced guiding rails, whereby the tolerance demands on the latter are reduced considerably. Also, the carts are advanced by way of stationary linear motors, which, supposedly, renders any tolerance demands on the longitudinal pitch of the tray units entirely superfluous. Also the tilting mechanisms may be given a very simple design according to the patent. However, it has been discovered that there are operational problems associated with this type of design, especially the operation of its linear motors and tilting mechanism.
While the design shown in U.S. application Ser. No. 08/632,012, filed Apr. 15, 1996 overcomes some of the problems associated with the prior art designs, some problems have begun to surface over time as the units have been operated. Specifically, there was a problem of wear on the pivot switch used to capture the wheel of the pull-down mechanism.
When the pivot switch is projected in front of the wheel, the wheel strikes the wall of the pivot switch and the wheel is rotating when the strike is made. The axle of the wheel is perpendicular to the direction of travel while the wall of the pivot switch is 30 degrees off of direction of travel. With the wheel rotating "lathe" action takes place between the pivot switch, wall and the wheel.
After the initial strike between the wheel and the pivot switch, the pressure between the two is relieved until the wheel has traveled past the pivot point and then the "lathe" action again repeats itself with the wear occurring on the pivot switch's tail.
Initially, a styrene wheel was used with a nylon pivot switch. The pivot switch was protected, but the wheel became sacrificial. Because there would be many more wheels to replace than pivot switches, it was preferable to fabricate the wheel from nylon and the pivot switch from Delrin.RTM. plastic, so that the wear appears on the pivot switch rather than the wheel. However, eventually the wheel wears the pivot switch sufficiently that the wheel can jump out of the track of the pivot switch and cause a missed tip which can also cause "cascading errors".
"Cascading errors" were first discovered when audits at the end of the chute indicated there were more errors occurring than were predicted by tray verification. Normally, when a tray is to tip to the right, immediately before the tray is being straightened, a series of photocells determines if the right hand arm is in the "low" or "tipped" position or the "up" or "latched" position. If the controls said that the arm should be tipped and the verifier says that the arm is tipped then it was assumed that the product went down the correct chute. However, in certain cases, tray verification would predict five errors but chute audits would indicate 35 errors. This previously unknown effect is referred to in this application as "cascade errors".
Most pull-down tilting mechanisms are actuated by spring when the pivot switch is released by an energizing solenoid. In other words, the pivot switch is spring-biased in the "out" position but held in the retained position by the solenoid.
When the computer provides a pulse, the solenoid plunger retracts, enabling the pivot switch to spring into the "out" position. The wheel strikes the pivot switch in front of the pivot point and the pivot switch unlatches the carriage and then as the wheel strikes the tail of the pivot switch, it pushes the pivot switch back to the home position and the spring on the solenoid plunger pushes the plunger into a detent capturing the pivot switch in the home position. The computer initiates the unlatch but it is the action of the wheel on the tail that normally relatches it.
If the solenoid does not return to capture the pivot switch before the wheel leaves the pivot switch's tail or a wheel is missing or broken, this will allow the pivot switch to move away from its intended home position back into the engagement position. The next tilt module that is not in the down position will then strike the pivot switch, tilt, and reset the pivot switch. If the pivot switch relatches properly this time, then that particular pivot switch will cause no more errors. If the pivot switch does not relatch it can again go into the engaged position and cause additional problems.
The cascade effect, though, comes from the first carriage that was tipped incorrectly, for if it were assigned a tilt position further downstream, when that carriage (which has been tilted incorrectly) gets in position to unload, the pivot switch at the proper destination chute will move into the engagement position. But because that arm has been incorrectly tipped upstream, no action will take place and the pivot switch will stay in the out position until the next untipped carriage arrives. That carriage will then be tipped at the wrong destination and should cause that pivot switch to relatch. If that particular tray was assigned a chute destination further downstream, when it arrives at its proper destination, the pivot switch will move into the engagement position, but again cannot engage because the tilt module is already in the low position, the tilt module will pass by and will not relatch the pivot switch. This pivot switch will then stay in the out position capturing the wheel of the next tilt module that is not tipped. This error will than continue to cascade downstream until eventually the error will pass the last destination and the system should heal itself.
However, there are some conditions that can exist that cause the error to not heal itself but continue to cause problems. An example would be if a particular tilt module were missing a wheel; that tilt module could then be loaded and when it gets to its destination, the pivot switch will go out to engage the wheel but with no wheel the module will not tip. The pivot switch will then catch the next available tray beginning the cascade problem. This will continue to repeat itself and will occur and start cascade error any time the tray with the missing wheel is assigned a destination.
One attempted solution to this problem is to use the tip verification switch to shut the sorter down if the pivot switch does not return to the "home" position within a given time period. However, with a large sorter this requires a maintenance man to then check the pivot switch to see if it should be reset and whether a wheel is missing. In the meantime, everything just sits on the sorter. For time critical applications, such as airline baggage sorting, this delay may be unacceptable.
Thus, there remains a need for a new and improved tilting mechanism for tilting a conveyor tray that reduces the chance of a mis-tip while, at the same time, is an uncomplicated design that is inexpensive and simple to manufacture and service.


A cleaning system for cleaning a moving surface of an image forming device, such as a photoreceptor. The cleaning system includes first and second links each having three pivot connections for pivotally connecting first and second cleaning blades together in mutually exclusive cooperative movement alternating between a common Cleaning Position at a first location and respective Suspended Positions. The cleaning system can include a Doctor Blade arrangement in which the cleaning blades are disposed in a Doctor Blade orientation in the Cleaning Position. The cleaning system can include a Wiper Blade arrangement in which the cleaning blades are disposed in a Wiper Blade orientation in the Cleaning Position. The first and second cleaning blades form similar Blade Holder Angles, Blade Deflection Angles and Working Angles when occupying the Cleaning Position.

Disclosed in embodiments herein are systems for cleaning an image forming device photoreceptor, and more specifically a dual blade cleaning system utilizing three-pivot links for moving the blades between separate Suspended Positions and a common Cleaning Position.
In electrophotographic applications such as xerography, a charge retentive photoreceptor belt or drum is electrostatically charged according to the image to be produced. In a digital printer, an input device such as a raster output scanner controlled by an electronic subsystem can be adapted to receive signals from a computer and to transpose these signals into suitable signals so as to record an electrostatic latent image corresponding to the document to be reproduced on the photoreceptor. In a digital copier, an input device such as a raster input scanner controlled by an electronic subsystem can be adapted to provide an electrostatic latent image to the photoreceptor. In a light lens copier, the photoreceptor may be exposed to a pattern of light or obtained from the original image to be reproduced. In each case, the resulting pattern of charged and discharged areas on photoreceptor form an electrostatic charge pattern (an electrostatic latent image) conforming to the original image.
The electrostatic image on the photoreceptor may be developed by contacting it with a finely divided electrostatically attractable toner. The toner is held in position on the photoreceptor image areas by the electrostatic charge on the surface. Thus, a toner image is produced in conformity with a light image of the original beam reproduced. Once each toner image is transferred to a substrate, and the image affixed thereto form a permanent record of the image to be reproduced. In the case of multicolor copiers and printers, the complexity of the image transfer process is compounded, as four or more colors of toner may be transferred to each substrate sheet. Once the single or multicolored toner is applied to the substrate, it is permanently affixed to the substrate sheet by fusing so as to create the single or multicolor copy or print.
Following the photoreceptor to substrate toner transfer process, it is necessary to at least periodically clean the charge retentive surface of the photoreceptor. In order to obtain the highest quality copy or print image, it is generally desirable to clean the photoreceptor each time toner is transferred to the substrate. In addition to removing excess or residual toner, other particles such as paper fibers, toner additives and other impurities (hereinafter collectively referred to as "residue") may remain on the charged surface of the photoreceptor.
The present application provides a new and improved apparatus for cleaning an image forming device moving surface, such as a photoreceptor surface, which overcomes at least the above-described problems.


Methods and systems for defining a compression and reconstruction scheme of a media stream, for generating and transmitting a base media layer and enhancement data layers and for reconstructing compressed representations of the media stream from the base media layer and the enhancement data layers.

Information signals, such as media signals and especially compressed video and audio streams and packetized audio and video streams propagate over a medium such as communication channels, and especially terrestrial, wireless, satellite and cable communication channels. Video streams usually include a relatively large amount of information and are usually stored in storage units and transmitted over communication channels in a compressed form.
The Moving Pictures Experts Group (MPEG) specifications are standardized methods for compressing and transmitting media signals such as video and audio.
As media signals, such as media signal arranged in streams, sequences of media signals and the like are transmitted over communication channels there is a need to match the bit rate of the media streams to the available bandwidth of the communication channels or to an available storage space of a storage unit. This match usually requires a reduction of the bit rate of the media streams. Very frequently, the bandwidth of even a compressed representation of a media stream requires more bandwidth than available and the transmission of the entire media stream is not feasible. Furthermore, a loss of media stream portions, such as packets conveying the media stream may result in severe quality degradation.
There is a need to provide methods and systems for a compact representation of a media stream. There is a further need to provide systems and methods for robust transmission methods of media streams, and especially systems and methods for allowing for recovering from a loss of some portions of the media stream. There is yet a further need to provide systems and methods for an efficient utilization of prioritized communication channels, quality of service communication channels and differential-service-supporting communication channels. There is another need to provide systems and methods for secure transmission of media streams. There is yet another need to provide an effective system and method for transmitting representations of media streams over variable bandwidth channels. There is a need to provide systems and methods for efficiently reconstructing a media stream from various representations of the media stream.

Method and system for scalable representation, storage, transmission and reconstruction of media streams


A fuel-fired water heater is provided with a flame spreader-type fuel burner assembly that reduces the operating NOx emissions of the water heater. The assembly includes a radial port gas burner coaxially disposed in a facing relationship with a generally inverted dish-shaped flame spreader which intercepts and is impinged on its concave side by the burner flames. In various disclosed embodiments of the flame spreader, during operation of the burner the burner flames pass through spaced series of openings extending through the flame spreader body inwardly of its outer edge periphery instead of being deflected horizontally outwardly past such periphery before passing upwardly beyond the flame spreader. The passage of the previously generated burner flames through these various openings serves to materially reduce the burner NOx emissions compared to a burner having an associated flame spreader with a conventional imperforate construction.

The present invention generally relates to fuel burner apparatus and, in a preferred embodiment thereof, more particularly relates to a heating appliance having a specially designed flame spreader-type fuel burner with lowered NOx (i.e., oxides of nitrogen) emissions.
Fuel-fired heating appliances such as furnaces, boilers and water heaters typically utilize combustion heat from a burner structure to controllably add heat to a heated medium such as air or water as the case may be. As might be imagined, these burner structures come in a wide variety of types, constructions and designs--each having its design strengths and weaknesses. In one particular type of fuel burner, to which the present invention is directed, a burner member from which flames emanate is positioned beneath a device typically referred to as a "flame spreader".
The flame spreader is typically a solid sheet of metal or other suitable noncombustible material, has a circular flat disc shape or a downwardly concave "hubcap" shape, and has a peripheral edge portion which is horizontally outwardly spaced apart from the actual flame generating burner section of the overall burner apparatus. As the burner flames travel upwardly they impinge on the bottom side of the flame spreader and are horizontally deflected thereby until they reach the peripheral flame spreader edge and turn upwardly past such edge. The purpose of flame spreaders of this general type is to stabilize and shape their underlying burner flame. Illustrative of this type of burner/flame spreader apparatus is the burner structure depicted and described in U.S. Pat. No. 4,134,719 to Velie.
In flame spreader-types of fuel burners, in common with other types of fuel burners, an increasingly stringent design requirement is the reduction NOx emissions from the burner. It would thus be desirable to provide a fuel burner of the flame spreader type which had a lowered NOx emission level, and to obtain this goal without greatly increasing the cost of the overall burner assembly. It is accordingly an object of the present invention to provide such a lowered NOx emission flame spreader-type burner for use in a fuel-fired heating appliance.

Flame spreader-type fuel burner with lowered NOx emissions


First and second screw threads along a feed screw permit a slide to be fed at two different speeds for a constant rotation of the feed screw. A first nut moves along the first thread. A second nut is threaded onto the outer diameter of the first nut for common translation along the first thread. Upon contacting a stop shoulder, the first nut stops translation and starts rotating with the screw. This rotation causes the second nut (and slide) to translate off the first nut and onto the second screw thread.

Since many types of machinery require several rates of travel along an axis during a machine cycle, this is a common machine design problem usually sought to be solved. For example, in metal cutting machine tools, it is frequently necessary to provide a rapid traverse or approach rate, where the tool comes from a clearance or home position, to a point near the workpiece where the tool then drops to a cutting feed rate. In a screw feed system for this application, it would be desirable to employ a screw which has a variable lead to obtain a variable axial feed velocity output resulting from a constant angular velocity input.
Molding machines, such as plastic injection molding machines, often have a continuous stroke cycle where a mold platen is moved along an axis with respect to a fixed platen, during a first stroke portion, in order to close a mold after a part has been extracted; a second stroke portion is used to drive the mold platens tightly against one another to withstand the injection pressures. The second stroke portion would usually involve a higher force than the first stroke portion of movement. In a screw feed system for this application, it would be desirable to employ a screw which produces a variable mechanical advantage with a nut system, based on constant input conditions.
It is well-known to provide two different threads on a common screw shaft in both "compound" and "differential" screw systems. The textbook, Kinematics of Machines, second edition, Prentice-Hall, Inc., defines these systems. A compound screw consists of two screws in series arranged so that the resultant motion produced is the sum of the individual motions. A differential screw consists of two screws in series arranged so that the resultant motion produced is the difference of the individual motions. In other words, with reference to a single thread system, a compound screw might be considered a coarse positioning device and a differential screw might be considered a fine positioning device.
One prior art device utilizes a compound screw to provide rapid positioning of a machine part, then converts to use only one of the two threads, for finer feed. U.S. Pat. No. 4,797,086, T. Adachi, Jan. 10, 1989 teaches an apparatus for closing a mold, where a movable mold platen is driven through part of its travel, by a compound screw. Two spaced nuts are used, with the first one fixed to the machine base and the second one mounted on the movable platen, the platen nut being selectively fixed, or freely rotatable, according to the state of an electric clutch. A feed screw has different threads at each end, of opposite hand helixes. When the electric clutch is energized, fixing the second nut, and a torque is transmitted to the screw through a spline, the screw moves through the first nut, and the second nut and platen move along the screw. Thus, the platen sees the addition of the two screw thread leads. The screw has an integrally-fixed mechanical clutch member between the end threads, and a mating mechanical clutch member is integrally-affixed to the second nut. At the precise time the mechanical clutch elements engage, the electric clutch must be deenergized; the now free-wheeling second nut then simply rotates with the screw while the first nut and mating screw thread continue propelling the platen in conventional single thread fashion.
Several difficulties are inherent in the '086 patent. The screw must be mounted to linearly advance while rotating. Lead errors in both screw threads are seen throughout the rapid feed stroke. An energizeable clutch must be provided, with precise energy control at the point where the mechanical clutch engages and disengages, in order to maintain a smooth, continuous motion. These difficulties are obviated by a feed system which uses two different thread portions on a screw where a nut system can smoothly translate from one thread to the other while the screw is rotating.


A YUV format to be stored in a memory is selected from A or B by a format judging unit for RGB data that is the input output display data of a memory unit, based on the comparison between chrominance (U, V) difference information on horizontal two pixels and the threshold values of U difference and V difference to be resistor-set at a format judging unit. The YUV data and information of A or B that are YUV format-converted at the format conversion unit are stored in the memory. The selection of the YUV format of A or B is, when the chrominance difference information is small as compared with the threshold value the format is YUV 422 (B conversion), and when it is large the format is that the low order bits of Y, U, V of each pixel are reduced (A conversion).

In the active matrix display device such as the TFT liquid crystal display and the like, with respect to an LCD driver (drive circuit) particularly for a mobile use such as a portable telephone and the like, an LCD driver containing a frame memory is in widespread use, which aims at low power consumption through elimination of data communications between a CPU (MPU) and the LCD driver at the time of displaying a still image or a standby screen.
For the still image, the standby screen, and the like, since one frame data can be carried by the frame memory of the LCD driver, the same data from the frame memory is read, so that display can be made without performing data communications between the CPU and the LCD driver.
However, when the frame memory is carried by the LCD driver, a chip size becomes large, and the cost thereof increases. On the other hand, the demand for a low cost system is generally advancing in the market, and chip size saving of the LCD driver is solicited. Hence, the LCD driver having no cost increase or a slight cost increase when carrying the frame memory is demanded in the market.
Hence, in the LCD driver of the conventional art, a display data is RGB-YUV converted (that is, converted from an RGB format to a YUV format), and particularly, by storing the display data in the memory (frame memory) by a YUV 422 format, in other words, by reducing the amount of the memory-stored data by compression, the chip size saving is realized. Note that, Y indicates luminance, and U and V indicate chrominance.
In the following, for comparison with the present invention, the system of a display drive (system and method) in the conventional liquid crystal display device (LCD) will be briefly described below. In the conventional method, in the liquid crystal display device, before storing the display data in the memory, the inputted display RGB data of 24 bits are serial/parallel converted, and the data of RGB 24 bits×2 for the parallelized horizontal two pixels portion is converted by YUV data, and is converted into a YUV 422 format.
Here, the YUV 422 format is a format which has luminance (Y) information for every one pixel without reducing the same, and averages the chrominance (U, V) information is a format averaged in the horizontal two pixels. In this YUV 422 format, the reason why the chrominance (U, V) information of the horizontal two pixels is averaged is because of the visual characteristic hard to be judged as the image degradation for human eyes.
As a result, the input display data is 48 bits for every horizontal two pixels, while in the YUV 422 format, it is possible that the input display data is 32 bits for every horizontal two pixels. Thus, the data amount-stored in the memory can be relatively reduced by about 30 percent.
In relation to the YUV processing (YUV format conversion processing) for the display data, Japanese Patent Application Laid-Open No. 2003-123062 and Japanese Patent Application Laid-Open No. 2005-055824 can be cited.
In Japanese Patent Application Laid-Open No. 2003-123062, a plurality of different tables performing YUV-Y′U′V′ conversion processing are provided in an LCD control unit, and from among these conversion tables, one table is selected so as to perform the YUV-Y′U′V′ conversion. As a result, the YUV-Y′U′V′ conversion matching the display image is performed, and after that, the YUV-RGB conversion processing is performed.
In Japanese Patent Application Laid-Open No. 2005-055824, an RGB data is converted into a YUV data, and the converted YUV format is separated into a luminance component and a chrominance component, and by giving consideration to the characteristic of a color space of the input data, data compression processing is performed. At this time, the luminance (Y) data realizes a lossless compression by Huffman coding processing (that is, compression ratio is changed depending on data), and the chrominance (U, V) data realizes reduction of information amount of the display data by performing quantizing lossless compression after reducing the information amount.


A diode bridge includes a plurality of diodes for coupling an input voltage signal to a holding capacitor for sampling when the diodes are forward biased, and uncoupling the voltage signal from the capacitor for holding when the diodes are reverse biased. The diode bridge has first and second bias current nodes. A constant current drain causes a constant bias current to flow out of the bridge. A transistor connects the first node to the drain for forward biasing the diodes, whereas a transistor connects the second node to the drain for reverse biasing the diodes. A bootstrap amplifier (A2) produces a variable control voltage which controls a pair of voltage-controlled constant current sources to cause the constant bias current to flow therethrough into the bridge. A transistor (Q7) couples the control voltage to the first current source for forward biasing the diodes, whereas a transistor couples the control voltage to the second current source for reverse biasing the diodes. The transistors are all bipolar and of the same conductivity type, preferably NPN.

1. Field of the Invention
The present invention generally relates to the field of electronic waveform sampling circuits, and more specifically to a power-efficient sample and hold circuit using bipolar transistors of single conductivity type.
2. Description of the Related Art
Sample and hold circuits charge a holding element, which is usually a capacitor, to the instantaneous amplitude of an analog input signal during a tracking or sampling interval, and then uncouple the signal from the capacitor during a holding interval. The sampled voltage which is held by the capacitor is typically applied to an analog-to-digital converter which produces a corresponding digital value which is stored in a random access memory of a waveform processing unit. A set of stored digital values obtained at increments of a sampled waveform constitutes a digital approximation of the analog signal, and can be analyzed or processed using a variety of known algorithms in accordance with a particular application.
FIG. 1 illustrates a basic prior art sample and hold circuit 10 including a diode bridge 12 such as described in U.S. Pat. No. 4,659,945, entitled "SAMPLING BRIDGE", issued Apr. 21, 1987 to A. Metz. The bridge 12 has a first bias current node N1 and a second bias current node N2. The anodes of diodes D1 and D3 are connected to the node N2, whereas the cathodes of diodes D2 and D4 are connected to the node N1. The cathodes of the diodes D1 and D3 are connected to the anodes of the diodes D2 and D4 respectively. An analog input voltage signal Vin for sampling is applied to the junction of the diodes D1 and D2, whereas an output signal Vout which appears at the junction of the diodes D3 and D4 is applied through an integrating resistor Rh to an integrating or holding capacitor Ch.
The diode bridge 12 further includes a diode D5 having a cathode connected to the node N2, and a diode D6 having an anode connected to the node N1. The anode of the diode D5 is connected to the cathode of the diode D6. A unity-gain replica of the output signal Vout is fed back through a buffer amplifier Al to the junction of the diodes D5 and D6 and designated as a bootstrap bias voltage Vbs. The diodes D5 and D6 are connected in anti-parallel relation to the diodes D1, D2, D3 and D4.
An NPN bipolar sampling transistor Q2 has a collector connected to the node N1 and an emitter connected to a constant current drain S1. A signal Vsample for selecting or commanding a tracking or sampling mode of operation is applied to the base of the transistor Q2. An NPN bipolar holding transistor Q1 has a collector connected to the node N2 and an emitter connected to the drain S1. A signal Vhold for selecting or commanding a holding mode of operation is applied to the base of the transistor Q1.
The drain S1 causes a predetermined constant bias current IBIAS to flow out of the bridge 12 through the node N1 and whichever transistor Q1 or Q2 is turned on into a voltage source VEE. A constant current source S2 is connected between a voltage source VCC, which produces a voltage higher than the voltage VEE, and the node N2. A constant current source S3, which is identical to the source S2, is connected between the voltage source VCC and the first node N1.
The sources S2 and S3 cause bias currents, each having a value of IBIAS/2, to flow into the bridge 12 through the nodes N2 and N1 respectively. In the illustrated topology in which the transistors Q1 and Q2 are of the NPN conductivity type, the sources S2 and S3 can be embodied by resistors (not shown).
The circuit 10 is operated in sampling mode by applying the sampling signal Vsample to the transistor Q2 and removing the holding signal Vhold from the transistor Q1. The transistor Q2 is turned on, thereby connecting the node N1 to the drain S1, whereas the transistor Q1 is turned off, thereby disconnecting the node N2 from the drain S1. The diodes D1, D2, D3 and D4 are forward biased, thereby coupling the signal Vin therethrough to the capacitor Ch which charges to the instantaneous value of the signal Vin to produce the signal Vout. The diodes D5 and D6 are reverse biased, and do not pass signal or bias current therethrough.
The bias current IBIAS flows out of the circuit 10 through the drain S1. Half of this current, IBIAS/2, flows through the source S2, node N2, diodes D1, D2, D3 and D4, node N1 and transistor Q2 to forward bias the diodes D1, D2, D3 and D4 and couple the input voltage signal Vin to the capacitor Ch. Another half IBIAS/2 of the bias current IBIAS flows through the source S3, node N1 and transistor Q2, and does not contribute to the sampling mode operation.
The circuit 10 is operated in holding mode by applying the holding signal Vhold to the transistor Q1 and removing the sampling signal Vsample from the transistor Q2. The transistor Q1 is turned on, thereby connecting the node N2 to the drain S1, whereas the transistor Q2 is turned off, thereby disconnecting the node N1 from the drain S1. The diodes D5 and D6 are forward biased by the bootstrap bias voltage Vbs, thereby causing the diodes D1, D2, D3 and D4 to be reverse biased and not pass signal or bias current therethrough, such that the signal Vin is uncoupled from the capacitor Ch.
The current IBIAS flows out of the circuit 10 through the drain S1 in holding mode as it does in sampling mode. Half of this current, IBIAS/2, flows through the source S3, node N1, diodes D5, and D6, node N2 and transistor Q1 to forward bias the diodes D5 and D6, reverse bias the diodes D1, D2, D3 and D4 and thereby uncouple the input voltage signal Vin from the capacitor Ch. Another half of this current, IBIAS/2, flows through the source S2, node N2 and transistor Q1, and does not contribute to the holding mode operation.
The diodes D5 and D6 must have a forward voltage drop which is larger than the forward voltage drop of the diodes D1, D2, D3 and D4 in order to cause the diodes D1, D2, D3 and D4 to be reverse biased when the diodes D5 and D6 are forward biased. Where a particular application must be implemented by diodes of a single type, the required effect can be produced by substituting two or more series diodes for each of the diodes D5 and D6, although not specifically illustrated.
The performance of the bridge 12 in following or tracking the input signal Vin can be improved by increasing the bias current flowing through the diodes D1, D2, D3 and D4 in the sampling mode. However, as described above, a current IBIAS/2, which is half of the total bias current IBIAS, flows around the bridge 12 from the source S3 and out through the node N1 in sampling mode rather than flowing through the diodes D1, D2, D3 and D4. This current IBIAS/2, which would improve the tracking performance of the bridge 12 if it flowed through the diodes D1, D2, D3 and D4 rather than bypassing the bridge 12, is wasted. The current IBIAS/2 which flows from the source S2 and out through the node N2 in holding mode is also wasted.
Another disadvantage of the circuit 10 in which the sources S2 and S3 are embodied as resistors is that since the voltage at the node N2 follows the input signal Vin, the current supplied into the bridge 12 through the sources S2 and S3 is modulated by the input voltage, thereby producing distortion in the signal Vout.
FIG. 2 illustrates an improvement to the circuit 10 in which all of the current IBIAS is caused to flow through the bridge 12 in both sampling and holding mode operation, in which like elements are designated by the same reference numerals used in FIG. 1. In a sample and hold circuit 16, the current sources S2 and S3 of the circuit 10 are replaced by a single constant bias current source S4 which causes the full bias current IBIAS to flow into the bridge 12. The circuit 16 includes a PNP bipolar transistor Q3 having an emitter connected to the source S4, a collector connected to the node N2 and a base connected to receive the sampling signal Vsample through an invertor IV1. A PNP bipolar transistor Q4 has an emitter connected to the source S4, a collector connected to the node N1 and a base connected to receive the holding signal Vhold through an invertor IV2.
In sampling mode, the transistor Q3 is turned on by the inverted sampling signal Vsample, thereby connecting the node N2 to the source S4. The transistor Q4 is turned off, thereby disconnecting the node N1 from the source S4. This causes the entire bias current IBIAS to flow from the source S4 through the transistor Q3, diodes D1, D2, D3 and D4 and transistor Q2 to the drain S1.
In holding mode, the transistor Q4 is turned on by the inverted holding signal Vhold, thereby connecting the node N1 to the source S4. The transistor Q3 is turned off, thereby disconnecting the node N2 from the source S4. This causes the entire bias current IBIAS to flow from the source S4 through the transistor Q4, diodes D5 and D6 and transistor Q1 to the drain S1.
Although the circuit 16 overcomes the drawbacks of the circuit 10 in that none of the bias current is wasted, the entire bias current is caused to flow through the bridge 12 in sampling mode and modulation of the source current by the input voltage is eliminated, it is not applicable to an integrated circuit topology in which all of the transistors must have the same conductivity type, either NPN or PNP. The circuit 16 is implemented by a complementary bipolar topology, with the transistors Q1 and Q2 being NPN conductivity type and the transistors Q3 and Q4 being PNP conductivity type.
Although it is theoretically possible to replace the transistors Q3 and Q4 with NPN transistors having their emitters and collectors reversed from the illustrated arrangement, the resulting circuit would be inoperative since the emitters of the NPN transistors would be connected to the bridge 12, the transistors would operate as emitter followers, and the voltage at the node N2 would follow the signal Vsample rather than the signal Vin.

Power-efficient sample and hold circuit using bipolar transistors of single conductivity type


There is disclosed an arrangement which has a projection means (LEDs) for projecting a light, a display means (mirror, finder view field range and the like) for guiding the light projected by the projection means to a predetermined display portion to display an index in the display portion, a variable means (masks, motor, decentring axis and the like) for periodically changing a projecting direction of the light of the projection means, and a control means (mask position detection circuit, control circuit and the like) for determining a projection timing of the projection means in accordance with the projecting direction changed by the variable means to control a position of the index on the display portion. By controlling the projection timing of the projection means, the position of the index in the display portion is controlled. Thereby, without irregularly or complicatedly changing the projecting direction itself, the index can be variously displayed.

1. Field of the Invention
The present invention relates to a display device for a display in a finder or the like of a camera or an optical apparatus.
2. Related Background Art
Recently, developments and researches have been eagerly advanced for a camera which can prevent a failure in photographing caused by a blurring from a hand vibration by a photographing person.
The camera is provided with a vibration sensor which accurately detects a vibration of the camera. Usually, by operating a correction mechanism for decentring a photographing optical axis based on detected information, an image blur is suppressed.
However, in a compact camera, since a finder is of an external type, not of a TTL system, the correction mechanism for decentring the photographing optical axis can correct a blur of an image being photographed, but cannot correct a blur in the finder while a photographing person aims at an object. Therefore, a finder mechanism also requires another image blur correction means.
To solve the problem, for example, the Japanese Patent Application Laid-open No. 5-204021 discloses a camera in which by restricting a periphery of a finder view field with an LCD (liquid crystal display), a blur quantity and a blur correction quantity are displayed.
Also, the Japanese Patent Application Laid-open No. 1-123219 discloses a camera in which a blurring from a hand vibration is optically displayed as a movement of a photo image.
On the other hand, recently, for the purpose of preventing a mistake of middle-off in automatic focusing (a phenomenon in which although a distance measuring region exists in a central point, a distance is measured by mistake in a case where main objects exist on the right and left sides in a finder view field or in other cases), a multipoint AF camera has become popular which is provided with plural distance measuring regions in a photographing screen.
In the finder view field of the camera, in many cases a distance measuring index exists only in a central portion. Therefore, it cannot be determined whether or not the middle-off can be prevented.
To solve the problem, a camera is increasingly manufactured and generalized in which only a distance measuring index of a selected distance measuring region is displayed by using an LCD incorporated in a finder optical system.
However, in the conventional camera disclosed in the aforementioned Japanese Patent Application Laid-open No. 5-204021, by restricting the display in the finder view field frame by the LCD, the blur quantity and the blur correction quantity are displayed, thereby resulting in following disadvantages.
(1) Since a resolution of a display pitch is determined by a divided pitch of an LCD segment, a blur is displayed remarkably roughly. A feeling of moving linearly in response to a blurring from a hand vibration cannot be grasped.
(2) Since the LCD needs to be incorporated in the finder optical system, the finder is made remarkably dark by the influence of an LCD transmittance and a polarizing plate.
(3) The LCD largely increases a cost.
Also, in the conventional camera disclosed in the aforementioned Japanese Patent Application Laid-open No. 1-123219, the blurring from the hand vibration is optically displayed as the movement of the photo image, but an effect of correction of the blurring is not displayed.
On the other hand, in the conventional multipoint AF camera, only the distance measuring index of the distance measuring region selected from plural distance measuring regions can be displayed. However, since the LCD is used, following defects are present: the finder becomes remarkably dark because of the influence of the LCD transmittance and the polarized plate; and the LCD largely increases a cost.


A lamp receptacle assembly has a hollow main body, a screw base disposed on a bottom of the main body, and a positioning plate inserted in the main body. The main body has two parallel slide rails, a through hole, an outer annular body, an inner annular body, a spacing, and a plurality of protruded plates. The positioning plate has a first channel, a second channel, a periphery slot, a rectangular groove, a first slot, and a second slot. A first conductive plate has a curved end and a first L-shaped end. A second conductive plate has a U-shaped end and a second L-shaped end. A U-shaped conductive plate has a curved terminal. The first conductive plate is inserted in the first channel. The second conductive plate is inserted in the second channel. The second L-shaped end is inserted in the periphery slot. The U-shaped end, the U-shaped conductive plate, and a fuse tube are inserted in the rectangular groove.

This invention relates to a lamp receptacle assembly, and more particularly, this invention relates to a lamp receptacle assembly which is disposed on a lamp string.
A conventional lamp string for a Christmas tree has a plug. An additional lamp string needs an additional plug. However, two lamp strings cannot be combined together because the additional plug cannot be disposed on the original lamp string in parallel. Since a receptacle cannot be disposed on the original lamp string in parallel, the additional plug cannot be disposed on the original lamp string. Referring to FIG. 1, a conventional lamp string has two wires 2 connected to a plurality of lamps in parallel. A plug 1 is connected to the ends of the wires 2. Each lamp has a socket 3 and a bulb 4 disposed on the socket 3. Since a receptacle cannot be disposed on the original lamp string in parallel, two lamp strings cannot be combined in parallel.


A semiconductor device containing a GaN FET has an isolating gate structure outside the channel area which is operable to block current in the two-dimensional electron gas between two regions of the semiconductor device. The isolating gate structure is formed concurrently with the gate of the GaN FET, and has a same structure as the gate.

Field effect transistors (FETs) made of III-N materials such as GaN exhibit desirable properties for power switches, such as high bandgaps and high thermal conductivity compared to silicon FETs. However, GaN FETs are undesirably susceptible to leakage current from the drain to the source through the two-dimensional electron gas outside the channel area.

III-nitride device and method having a gate isolating structure


The arrangement is directed to a roller excitation device for frictionally ngaging and turning rollers of a roller box assembly. The roller box assembly is of the type that includes a generally U-shaped housing having a partial tube which covers the open end of the housing, and a plurality of rollers captured by the housing. The rollers and partial tube define a space through which a cable is received. The arrangement being such that the rollers are adapted to roll upon engaging the cable located in the space defined by the tube and rollers. The roller excitation device includes a body portion fabricated from resilient material and sized for occupying the space defined by the tube and roller and for frictionally engaging the rollers, and means for moving the body portion over the rollers. Preferably, the body portion has an outer surface with a plurality of ribs extending outwardly along the circumference of the body portion. The ribs engage the rollers for causing them to turn upon moving the body portion thereover.

(1). Field of the Invention
This invention relates generally to pipes having roller boxes located at bends in the pipes for aiding the movement of cables positioned within the pipes, and more particularly to a roller excitation device which is used to cause rollers housed by such roller boxes to roll or turn.
(2). Description of the Prior Art
In certain applications, there is a pipe located outboard of a vessel. This pipe has a cable located therein. Typically, the pipe has bends formed in it, and, in order to minimize the friction encountered by the cable as it passes through the pipe and negotiates the bends, roller box assemblies are positioned at these bends. FIG. 1 illustrates a vessel wall 10 with a section of pipe 12 having a pair of roller box assemblies, each generally indicated at 14, positioned at the bends of the pipe 12. As shown, a roller box assembly 14 can be positioned anywhere along the length of the pipe 12 where it bends or turns.
FIGS. 2 and 3 illustrate a single roller box assembly 14 in plan view and cross section view, respectively. As shown in FIG. 2, the roller box assembly 14 has an arcuate housing 16 and a plurality of rollers, each indicated at 18, positioned within the housing 16. Referring to FIG. 3, the housing 16 of the roller box assembly 14 has a generally U-shaped cross section. Specifically, the housing 16 has a partial tube 20 which covers the open end of the housing 16 and a plurality of roller shafts or pins 22 captured by the housing 16, each roller shaft 22 having the roller 18 mounted thereon. The rollers 18 extend perpendicularly with respect to the direction of a cable 24 located in the space defined by the partial tube 20 and the rollers 18. The arrangement is such that each roller 18 is adapted to roll upon engaging the cable 24 when moving the cable 24 linearly through pipe 12 and roller box assemblies 14. This rotation of the roller 18 upon engaging the cable 24 eases the linear motion of the cable 24 passing through the pipe 12 at the bend.
Occasionally, rollers 18 and/or roller shafts 22 become immobile or seize due to a variety of causes (e.g., lack of lubrication, foreign objects preventing rotation of the rollers, etc.). In order to ensure that the roller box assemblies 14 perform their intended function, it is necessary to both test the assemblies 14 and to identify rollers 18 that are seized. Presently, there is no way of detecting or identifying whether rollers 18 are functional or non-functional. The present invention is provided for overcoming these above-noted constraints.

The United States of America as represented by the Secretary of the Navy


Apparatus and method for receiving a QAM signal using a backward compatible hierarchical coding scheme to increase data transmission using finer constellations, while maintaining compatibility with existing Direct Broadcasting Satellite (DBS) systems. The apparatus employs multiple stages of decoders such that the finer constellations of the QAM signal are unraveled at different stages.

Power and bandwidth are resources that are carefully conserved by digital transmission systems through the proper selection of modulation and error correction schemes. Quadrature Amplitude Modulation (QAM) is one form of multilevel amplitude and phase modulation that is frequently employed in digital communication. A QAM system modulates a source signal into an output waveform with varying amplitude and phase.
QAM is a form of two-dimensional symbol modulation composed of a quadrature (orthogonal) combination of two PAM (pulse amplitude modulated) signals. Data to be transmitted is mapped to a two-dimensional, four quadrant signal space, or constellation, having a plurality of signal (phasor) points each representing a possible transmission level. Each constellation signal point is commonly called a "symbol" and is defined by a unique binary code. The QAM constellation employs "I" and "Q" components to signify the in-phase and quadrature components, respectively, where a QAM data word or symbol is represented by both I and Q components.
QAM signals may employ words or symbols of different lengths and/or constellation shapes (e.g., circular, square, rectangular, cross, hexagonal or any arbitrary shapes). Although the present invention is described using a square QAM constellation, those skilled in the art will realize that the present invention can be modified for other QAM constellation shapes or QAM signal word of different lengths.
Generally, an increase in the number of phasor points (finer, higher order constellations) within the QAM constellation permits a QAM signal to carry more information, but the increase in density of the phasor points creates a disadvantage where the transmitted power is no longer constant. In fact, if the average transmitted signal power is limited, the maximum I and Q values are nearly the same for all the QAM levels, thereby causing the constellation points to be closely spaced as the QAM level increases. Since the distance between phasor points on a QAM constellation generally decreases with additional phasor points, it increases the complexity of distinguishing neighboring phasor points, and translates into a more expensive and complex receiver.
Thus, many older or existing DBS (Direct Broadcasting Satellite) systems employ Quaternary (Quadriphase) Phase Shift Keying (QPSK) modulation systems. For QPSK, a synchronous data stream is modulated onto a carrier frequency before transmission over the satellite channel, where the carrier can have four (phase) states, e.g., 45.degree., 135.degree., 225.degree. or 315.degree.. Thus, similar to QAM, QPSK employs quadriphase or quadrature modulation where the phasor points can be uniquely described using two orthogonal coordinate axes.
However, in contrast to QAM, QPSK has a "constant envelope", i.e., the pair of coordinate axes can be associated with a pair of quadrature carriers with a constant amplitude, thereby creating a four level constellation (four phasor points having a phase rotation of 90.degree.). This large separation of phasor points decreases the complexity of performing carrier recovery operation at a receiver, and the constant envelop is extremely desirable for power sensitive satellite transmission systems. Also, the constant power level allows the satellite amplifiers to operate in saturation.
Nevertheless, the desire to increase the data throughput over a satellite channel has created a strong incentive to consider other transmission schemes instead of QPSK. Due to the existence of numerous QPSK systems, it is herein recognized as desirable to provide a method and apparatus for processing a signal such as a QAM signal using a backward compatible hierarchical coding scheme to increase data transmission using finer constellations, while maintaining compatibility with existing systems including DBS systems.

Apparatus and method for processing a Quadrature Amplitude Modulated (QAM) signal


Method for manufacturing a bearing ring (14, 34, 36) from at least one steel bar (12) having ends. The method comprises the steps of forming said at least one steel bar (12) into at least one ring segment and flash butt welding the ends (12a, 12b) of said at least one ring segment to make a ring. The method also comprises the step of carburizing at least part (C) of a surface (12c, 12d) of said at least one steel bar (12) which is adjacent to said surface (12a, 12b) that is to be flash butt welded prior to said flash butt welding.

Flash-butt welding, or "flash welding" is a resistance welding technique for joining segments of metal rail, rod, chain or pipe in which the segments are aligned end to end and electronically charged, producing an electric arc that melts and welds the ends of the segments, yielding an exceptionally strong and smooth joint.
A flash butt welding circuit usually consists of a low-voltage, high-current energy source (usually a welding transformer) and two clamping electrodes. The two segments that are to be welded are clamped in the electrodes and brought together until they meet, making light contact. Energizing the transformer causes a high-density current to flow through the areas that are in contact with each other. Flashing starts, and the segments are forged together with sufficient force and speed to maintain a flashing action. After a heat gradient has been established on the two edges to be welded, an upset force is suddenly applied to complete the weld. This upset force extrudes slag, oxides and molten metal from the weld zone leaving a welding accretion in the colder zone of the heated metal. The joint is then allowed to cool slightly before the clamps are opened to release the welded article. The welding accretion may be left in place or removed by shearing while the welded article is still hot or by grinding, depending on the requirements.
A welded bearing ring may be subjected to a post-welding heat treatment, such as carburizing, in order to increase its surface hardness, wear resistance and/or fatigue and tensile strength. Carburizing is a heat treatment process in which an iron or steel component is heated in the presence of another material that liberates carbon as it decomposes. The outer surface of the component will have a higher carbon content than the original material. When the iron or steel component is cooled rapidly by quenching, the higher carbon content on the outer surface becomes hard, while the core remains soft (i.e. ductile) and tough.

Method of making a bearing ring, a bearing ring and a bearing