A picker bar includes spindles which are nonaligned in the vertical direction to define two or more offset sets of spindles on the bar and increase the number of spindles per unit length of the spindle bar. A spindle assembly includes support carrying two spindles driven from a picker bar drive shaft by single drive gear. Driven spindle gears are spaced on opposite sides of the shaft axis to facilitate close spacing of the spindles.

Cotton harvesters often have a row unit structure with picker drums rotatable about upright axes adjacent a row-receiving area of the unit. The drum includes a plurality of upright picker bars having spindles which rotate in contact with cotton plants to remove the cotton. Corresponding spindles on the bars define generally horizontal spindle planes, with a typical drum having eighteen to twenty spindle planes. Doffers which rotate between the spindle planes in contact with the spindles to doff cotton wound on the spindles and direct the cotton towards air door structure for removal from the unit towards a basket or processor.
A conventional picker bar includes a single row of spindles spaced uniformly in the vertical direction. Each spindle includes a gear end engaged by a mating bevel gear located on an upright spindle drive shaft supported for rotation within a hollow portion of the bar. The spacing between the spindle planes and thus the density of the spindles on the picker bar is limited by the spindle support and spindle drive arrangement. Currently available drive shaft bevel gear and the spindle nut mounting arrangements prevent closer spacing of spindles. Therefore, increasing the spindle density for increased drum productivity while maintaining the reliability of the spindle, spindle bar and spindle drive has heretofore been a continuing source of difficulty.

High density cotton picker bar and spindle assembly therefor


A method using a mixer for disbursing an additive in a tube of compound. The mixer includes a rigid cylinder and a plunger assembly. The cylinder is configured for receiving an opened tube of compound, to which additive has been introduced. The plunger assembly includes a shaft, on which a cap is slidably and rotatably mounted. A mixer blade is mounted on a first end of the shaft and a second end of the shaft is provided with a handle. The cap is provided with a pair of cutouts designed for receiving a pair of studs mounted on the outside surface of the cylinder, such that the cap may be fitted on the cylinder and turned to engage the studs with the cutouts and connect the cap and the cylinder. The handle may be rotated and reciprocated to move the mixer blade through the contents of the tube for mixing.

1. Field of the Invention
The present invention relates to methods and apparatus for mixing an additive with a compound having a viscous and stiff consistency, and more particularly to methods using a hand held manually operated mixer capable of distributing an additive throughout such a compound disposed inside a retail dispensing tube.
2. Description of the Prior Art
Compounds used for caulking and grouting are formulated to be workable but viscous and relatively stiff. These compounds are formulated for application to joints and cracks by pressing the compound into an opening and smoothing the exposed surface, with the use of a tool designed for the purpose. The stiffness prevents the material from readily migrating, after application, even when the compound is applied on a vertical wall. Theviscosity causes the compound to adhere to the surfaces in cracks and joints to achieve a complete filling of the space, even when the compound is dragged somewhat by the smoothing phase of the work.
Unfortunately, the viscosity and stiffness, which make the compounds suitable for grouting and caulking also make the compounds difficult to handle. Suppliers have responded by delivering compounds for caulking and grouting in retail dispenser tubes. The tubes are typically a plastic or lined paperboard cylinder with a fixed wall at a front end and a thrust cap at an opposite filler end. The fixed wall is provided with a centered hole, through which a tapered dispenser tip extends. The supplier fills the tube, through the filler end and inserts the thrust cap to seal the compound inside the cylinder. The user opens the tube, for use, by cutting the dispenser tip at a location selected to provide an opening of desired diameter. The user places the tube in a caulking gun, which is configured with a ratchet driven trigger mechanism for gradually advancing a push rod. The push rod engages the thrust cap, of the tube, and presses the thrust cap forward through the tube to dispense the compound through the opening in the tip. The user may move the tip over an area where the compound is to be applied while operating the trigger mechanism to dispense the compound at a desired rate. The compound may be smoothed after it is applied to finish the job. The retail tube and calking gun allow a user to dispense the compound directly where it is needed without the necessity of removing the compound from the tube or otherwise handling the compound prior to use.
The retail tube and caulking gun are ideal for pre-mixed or one step compounds, which can be sold in the ready-to-use tubes; however, when an additive is required, the user must handle the compound to some extent. Certain quick setting compounds require that a catalyst be added immediately before use. For certain caulking jobs, it is desirable that the caulking compound be tinted with colorant before use, in order to match the compound with the color of adjacent surfaces such as walls or ceilings. While it is possible to add colorant in advance, it is not practical for a supplier to provide various compositions of caulking compound in all color variations. It is standard practice to purchase an untinted caulking compound and to add the colorant by mixing. When a fast acting catalyst is required or when color tinted caulk is needed, the user must mix an additive with the compound.
In order to minimize the handling of the compound, typical conventional methods of mixing an additive with caulking or grouting compound are practiced with the compound remaining in the retail tube. A U.S. Patent Application 2006/0151531, to Tikusis discloses a method of supplying the additive in a separate reservoir, which is disposed in the tube beside the compound. The additive and the compound are dispensed simultaneously into the dispenser tip and are mixed as they are dispensed. Another method, disclosed by U.S. Pat. No. 4,114,196, to Lostutter, uses a frame configured to hold retail tubes of compound and adapted for loading on a conventional paint shaker. The thrust cap is removed, the additive introduced to the compound inside the tube, and the tube is shaken to mix the additive and the compound. Finally, U.S. Pat. No. 7,070,318, to Renfro discloses a mixer blade mounted on a shaft. A mixer head is slidably and rotatably mounted on the shaft and the mixer head is configured for sealable engagement with the filler end of the tube. Two motors are used to rotate and reciprocate the mixer blade inside the tube containing the additive and the compound.
Alternatively, one motor may be used to rotate the mixer blade and reciprocation may be supplied manually in the manner of a soda fountain milkshake mixer. The mixer blade is designed with a continuous circumferential edge which is intended to remain adjacent to the inside surface of the tube, for scraping the compound from the side of the tube during the mixing operation.
Generally, the method of mixing the additive and the compound in the dispensing tip, at the point of application does not yield acceptable results, particularly in the case of color tinting, where a thorough and even dispersal of the colorant is necessary to achieve uniform appearance. The mechanical shaker of Lostutter and the mixing apparatus of Renfro require bulky equipment and a power source. These methods are suitable for mixing, by the retailer, at the point of sale.
There is a need for an effective apparatus and method of mixing an additive into a compound, in the retail tube, which can be used at a work site.
There is a need for an effective apparatus and method of mixing an additive into a compound, in the retail tube, which does not require bulky equipment or a power source.
Finally, there is a need for a hand held manually operated mixer and method for mixing an additive into a compound, in the retail tube.


A system for detecting hazardous agents is based on cellular telephone networks. The cellular telephones in public circulation have at least one detector for detecting at least one hazardous agent and broadcast alarm packets upon detecting the hazardous agent. A computer or computer network interconnected with telephones by the cellular telephone network processes the alarm packets and sets an alarm condition for the hazardous agent in a vicinity of the cellular telephone by calculations based upon alarm packets from other telephones with detectors for the hazardous agent in the vicinity. A map of the contaminated area is also created.

The present invention is related to electronic systems for the detection and location of hazardous agents and, more particularly, to such systems based upon mobile telephone networks.
Sources of hazardous agents, such as biological, chemical, and radioactive materials, are plentiful in modem society and the possibilities of their release must be faced. Furthermore, given the present threat of terrorism, the dangers of the purposeful release of these agents is also a real possibility. Hence there is the need for a network of ubiquitous detectors which are capable of sensing such biological, chemical, and radioactive agents.
Various networks, detectors and combinations of networks and detectors have been proposed in response. One proposal has been the deployment of such detectors in simple combination with, or as an integral part of, cellular (or cell) telephones. Cell telephones are ubiquitous in modem societies and are transported everywhere. As normally used telephones, the telephone owners are likely to keep the telephones charged and in good working order. Canadian Patent No. 2,418,612, which issued to Marian Gavrila and Gabriel Patulea, describes the incorporation of chemical, radiation, and biological agent detectors in cell phones and U.S. Pat. No. 6,697,645, which issued to J. M. MacFarlane, discloses the incorporation of environmental sensors into cellular phones.
Efforts at numerous national laboratories, universities, and businesses have focused mostly on sensor development. For example, Lawrence Livermore National Laboratory is currently developing radiation detectors which can be embedded in PDA (Personal Digital Assistant)/cell telephone devices which are part of a wireless network known as RadNet. These devices are to be deployed with specially trained personnel, such as firefighters, utility workers, police, and custom agents, as a first response team. But the relatively low number of such people compared to the general population means that the detectors, or sensors, must necessarily be highly sensitive and accurate. These requirements imply that deployment of such a network system is likely to be many years away. Other efforts include research on wireless networks of autonomous sensor devices; e.g., Graviton Corp. of San Diego is developing a network independent of existing cell telephone infrastructures.
Despite these efforts, these network systems suffer from various deficiencies, such as lack of geographical coverage, and high costs of installation and maintenance. The distribution of detectors/cell telephones to special personnel limits the distribution of the sensor network. Sensitive and accurate detectors raise the initial and maintenance costs of the sensor/PDA/cell telephone (or autonomous sensor) devices and the installation of special wireless networks further adds the total of network system costs.
On the other hand, the present invention provides for a network system which is inexpensive to operate with easy installation and low maintenance costs.

Mobile telephone network-based system for detection and location of hazardous agents


There is set forth herein an actuator having a housing and a piston assembly. The piston assembly can have a piston and a piston rod extending from the piston. In one embodiment, the housing can receive the piston and a portion of the piston rod. The piston assembly can define a piston assembly interior and a fluid reservoir can be located within the piston assembly interior. A chamber region within the interior of the housing can be separated by the piston assembly to define a piston side chamber and rod side chamber. The piston assembly can be moveable so that respective volumes of each of the piston side chamber and the rod side chamber are variable. For operation of the actuator by movement of the piston assembly within the interior of the housing, fluid can be moved between the reservoir and the chamber region.

Actuators are currently available in multiple varieties including electric ballscrew actuators, electric threaded rod actuators and Electric Hydraulic Actuators (EHAs).
According to one currently available EHA design an EHA includes a hydraulic cylinder unit with a fully encapsulated hydraulic supply system comprising a reservoir, check valves and relief valves, and a hydraulic pump, which is powered by an electric motor. The reservoir includes a volume of compressed gas separating the gas from the hydraulic fluid and allowing for orientation independent operation of the unit. In general, when the electric motor is driven in a first rotational direction, the hydraulic pump moves the fluid into the fluid chamber of the hydraulic actuator and out of the piston chamber, thereby extending a piston rod from the actuator housing. When the electric motor is driven in a second rotational direction, opposite the first rotational direction, the hydraulic pump moves the hydraulic fluid out of the fluid chamber and into the piston chamber, thereby retracting the rod.


In a storage system such as a SAN, NAS, or storage array that implements hierarchical performance tiers based rated drive access latency, on-drive compression is used on data stored on a first tier and off-drive compression is used on data stored on a second tier. Off-drive compression is more processor intensive and may introduce some data access latency but reduces storage requirements. On-drive compression is performed at or near line speed but generally yields lower size reduction ratios than off-drive compression. On-drive compression may be implemented at a higher performance tier whereas off-drive compression may be implemented at a lower performance tier. Further, space saving realized from on-drive compression may be applied to over-provisioning.

High-capacity data storage systems such as storage area networks (SANs), storage arrays, and network-attached storage (NAS) are used to maintain large storage objects and contemporaneously support multiple clients or host servers. Such storage systems may include compute nodes that manage access to host application data that is stored on arrays of drives. The drives are typically organized into protection groups such as redundant arrays of independent drives (RAID). The compute nodes respond to input-output (IO) commands from the clients or host applications running on the host servers. Examples of host applications may include, but are not limited to, software for email, accounting, manufacturing, inventory control, and a wide variety of other business processes.
Hierarchical storage tiering is often implemented in high-capacity data storage systems. Identical drives of a single technology type with the same rated data access latency are grouped together to create a tier in which drives are RAID members. Different types of drives are used to create different tiers that are hierarchically organized based on rated performance of the drives. For example, a fast tier could consist of enterprise flash drives (EFDs) and a slow tier could consist of hard disk drives (HDD), where the EFDs have a lower rated access latency than the HDDs. Extents of data are promoted and demoted between the tiers based on frequency of access. Extents that are accessed relatively more frequently are placed on the fast tier and extents that are accessed relatively less frequently are placed on the slow tier.

Using drive compression in uncompressed tier


A braking system for a machine includes a first valve assembly having a first electronically actuated proportional valve, and a second valve assembly having a second electronically actuated proportional valve. The braking system includes a first pressure sensor and a second pressure sensor disposed downstream of the first and second valve assemblies, respectively. The first and second pressure sensors are configured to determine a first pressure and a second pressure of a braking fluid from the first and second valve assembly. The braking system also includes a controller configured to receive a signal indicative of the first pressure and the second pressure of the braking fluid and compare the first pressure and the second pressure. The controller is configured to selectively actuate at least one of the first electronically actuated proportional valve and the second electronically actuated proportional valve to substantially equalize the first pressure and the second pressure.

Typically, machines, such as motor graders, may include a braking system having two independent braking circuits for increased safety and to conform to statutory regulations. Such a braking system generally includes two separate brake valves or two sections within the same brake valve. Due to design and tolerances, these separate brake valves or valve sections typically result in a pressure bias, i.e., different braking pressures for the two braking circuits. This pressure bias may cause premature brake failure due to higher pressure and resulting higher energy load.
Various solutions are proposed in the prior art to decrease the pressure bias. For example, a mechanical device, such as a by-pass valve, may be provided to reduce the pressure bias. However, using such mechanical devices may increase cost of the braking system. Additionally, the mechanical devices may not be suitable for dynamic changes in pressure bias.
For reference, U.S. Pat. No 4,729,607 discloses a dual circuit brake valve with a delivery differential control mechanism which controls the differential between the delivery pressures of the primary and secondary braking circuits. The delivery differential control mechanism includes a spring retainer which is mounted on the end of the stem of the relay valve and which receives a spring-biased plunger. The plunger engages with the actuating member during the brake application to thereby transfer the force of the spring to the relay member and therefore to the valve members of the secondary circuit. This transfer of the spring force reduces the crack open pressure of the valve members controlling communication through the secondary circuit, to thereby reduce the differential between the pressures generated and the primary and secondary circuits.


A capacitor having improved surface breakdown voltage performance and a method for applying laser marking to capacitors which does not reduce capacitor surface breakdown voltage, can be applied using existing laser marking technologies and apparatus, and which results in a mark that is legible and clear, is disclosed. In a first exemplary embodiment a capacitor includes a laser mark which is located near one of the capacitor terminals. The exact location is not critical as long as the mark does not make physical contact with the terminal. Conventional laser marking technologies and apparatus may be used to fix the mark in the new location. In a second embodiment the laser mark is oriented so that a flat portion of the mark is is oriented closest to the adjacent terminal.

1. Field of the Invention
The present invention relates to high-voltage capacitors and, more particularly, to a capacitor having improved surface breakdown voltage performance using novel method for applying laser or conductive ink marking which increases capacitor surface breakdown voltage.
2. Description of the Prior Art
Capacitors are second only to resistors as electronic circuit elements and are used in virtually every type of electronic circuit. In a typical application, capacitors are used as coupling capacitors in electronic circuits to block a direct current (DC) voltage while allowing alternating current (AC) currents to pass. They are also used as bypass capacitors to prevent the voltage at a circuit node from changing. These two applications do not depend on the exact value of the capacitance. In other applications, capacitors are also used in inductor-capacitor (LC) resonant circuits, in resistor-capacitor (RC) bridges, and as timing elements. In these applications the precise value of the capacitor is usually significant. Capacitors may also be used for accurate charge storage; for example, in sample-and-hold circuits or frequency-to-voltage converters. In these applications, the quality of the dielectric is more important than the capacitance, as long as the latter is stable.
Capacitors are used store charge for discharge through lamps, as in photographic flash lamps or stroboscopes. Capacitors are also used in filtering applications, both in power-supply filters and signal processing applications, often in conjunction with operational amplifiers or other analog circuit components. In power circuits, capacitors may be used to shift phase, as in capacitor-start motors, or for power factor compensation in the case of inductive loads. Finally, capacitors are extremely important in integrated circuits, where they are structured as metal or polysilicon films with silicon dioxide dielectrics on silicon.
A capacitor is typically constructed from two or more conducting electrodes, each of area A and separated by distances d. In most cases, the separations between the conducting electrodes are maintained by sheets of dielectric material of thickness d and having a dielectric constant k. The capacitance of this parallel-plate capacitor (in Farads) is given by C=ekAn/d F, where A is in m2 d is in meters, n is the number of parallel conducting electrodes, and pi=3.1415926. In SI units the constant is e=4(pi)/c2=8.854×10−12 F/m. In units of centimeters, the capacitance is given by C=kAn/4(pi)d, where A is now in cm2 and d in cm.
While the net charge on a capacitor under an applied voltage is zero, equal and opposite charges ±Q are induced on adjacent pairs of electrodes. The charge on the capacitor is thus taken to be |Q|, the absolute value of the charge. If one terminal of a capacitor has a polarity marking, say a +, then Q>0 means there is a positive charge Q on the corresponding electrode; similarly, Q<0 means there is a negative charge on that electrode. Further, given a current i=dQ/dt, a positive current flowing into the positively marked terminal will cause the voltage V across the capacitor to increase. The voltage V is the potential difference between the electrodes, and this voltage is positive if the potential of the positively marked plate is higher than the potential of the other.
In an ideal capacitor, the voltage V is proportional to the charge Q, and the constant of proportionality is defined as the capacitance C. More particularly, Q=CV, or C=Q/V. Most capacitors are close to ideal if the voltage is not excessive and does not vary too rapidly. Conventionally, the units are defined so that a unit charge is one coulomb, and unit voltage is one volt, or one joule/coulomb. The corresponding unit of capacitance is therefore one Farad, or one coulomb per volt. The Farad is an impractically large unit, so the microfarad (10−6 Farad) or picofarad (10−12 Farad) is commonly used in practice.
As discussed above, most practical capacitors include a dielectric material between the electrodes. The electric field E=V/d between the electrodes passes through the dielectric, terminating on the induced charges charges on the electrodes. Within the dielectric, the charges are elastically bound to their equilibrium positions and can only move slightly in response to the electric field. The positive charges move in the direction of the electric field, and the negative charges move in the opposite direction.
When placed between the parallel electrodes of a capacitor, the dielectric is polarized by the electric field. In order to maintain the electric field at V/d, the extra charge at the surfaces of the dielectric is balanced by equal and opposite charges on the electrodes. At the positive electrode, which had a charge density of E/4(pi) without the dielectric, a charge density P is added resulting in a total charge density of E/4(pi) +P=(E+4(pi)P)/4(pi). The combination E+4(pi)P is the total charge per unit area on the electrode and is analogous to E, the charge per unit area in the absence of the dielectric.
The combination D=E+4(pi)P is called the electric displacement. The flux of D through a closed surface is 4(pi) times the amount of free charge enclosed. The free charge is the total charge less the charge contributed by polarization, and represents that part of the charge that can move, while the polarization charge remains fixed.
A dielectric constant k can be defined in terms of the electric displacement as D=kE. The charge on the capacitor electrodes in the presence of the dielectric is thus s=D/4(pi)=kE/4(pi). Therefore, the total charge Q is increased by the factor k and the capacitance is now C=kAn/4(pi)d. Likewise, introducing a uniform dielectric reduces the electrode potentials by a factor 1/k, since the electric fields must be reduced by this factor to keep the same charge Q. Therefore, the effect of adding the dielectric is to increase the capacitance C while keeping area A and separation d constant.
The principal dielectric materials currently in use include mica, Mylar, polystyrene, polypropylene, polycarbonate, polyester, ceramic, aluminum electrolytic, tantalum electrolytic, and gold double layer.
The maximum voltage at which a capacitor can be used is determined by the formation of an electrical discharge in the dielectric. The heat produced by the discharge usually damages the capacitor, except in the case of an air or liquid dielectric, in which little permanent damage may be done. The dielectric strength is the maximum voltage difference that a given thickness of dielectric can sustain without electrical breakdown. Capacitors having improved voltage breakdown performance are in continuous demand in modern electronic circuits and devices, including flat panel and plasma televisions, telecommunications equipment, and military electronics systems.
High-voltage capacitors rated at 2,000 volts or more typically use a floating electrode design to increase effective dielectric thickness and to control electric field gradients within the capacitor. A key parameter of a high-voltage capacitor is the surface breakdown voltage, which defines the maximum voltage at which a capacitor can be used. The surface breakdown voltage is caused by inter-terminal current leakage across the outer surface of the capacitor body, as opposed to discharge between the electrodes and through the dielectric. Thus, the delectric constant of air (k=1.0006) is a key determinant of the surface breakdown voltage.
Most capacitors are marked with the capacitor value and voltage limit. For example, one common scheme uses three digits to indicate a value in picofarad. The first two digits are significant figures, and the final digit is a decimal exponent. Thus, 104 translates to 10 followed by 4 zeros, 100000 picofarads 0.1 microfarads; 472 means 4700 picofarads or 0.0047 microfarads. Other letters and numbers on disc ceramic capacitors are usually the temperature range or value tolerance. For example, 0.1Z Y5S means 0.1 microfarads, tolerance −20%+80%, useful temperature range −30° C. to 85° C., ±22% variation in value over this range. At one time, small capacitors were labeled with colored stripes like the resistor code, and mica capacitors in molded packages had six or three colored dots interpreted the same way; however, there is no uniform series of preferred values for capacitors as there is for resistors.
In addition to capacitor value, modern certified safety capacitors use a laser or conductive ink mark specific to each manufacturer of those safety capacitors to signify that they are safety certified by either the TUV or UL. A typical Multi-Layer Chip Capacitor (MLCC) marking is located on the top center of the device package. This location reduces the creepage, or arc distance, between the device terminals by effectively dividing the inter-terminal distance in half. This occurs because many of the marking inks use metal or carbon particles for color and are therefore slightly electrically conductive. In addition, the shape and size of the mark, along with its orientation, can also have an impact on surface breakdown voltage. Thus, conventional laser marking processes effectively create a slightly conductive island on the dielectric surface in the middle of the device between the terminals, thereby reducing the surface breakdown voltage.
Accordingly, there is a need capacitors having improved surface breakdown voltage performance, and a method for applying laser or conductive ink marking to capacitors which does not degrade or reduce capacitor surface breakdown voltage, is easy to apply using existing laser marking technologies and apparatus, and which results in a mark that is legible and clear.

Capacitor having improved surface breakdown voltage performance and method for marking same


A method, apparatus and computer program product for the express forwarding frames having multiple fragments are presented. A timer (NAV) is maintained at each respective node of a wireless Local Area Network (LAN). At least two fragments of a frame are designated as a Time Sensitive Quality of Service (TSQ) frame fragments to be express forwarded. A duration field of each of the TSQ frame fragments is incremented by a first predetermined time increment (DT0) before the TSQ frame fragments are forwarded. The TSQ frame fragments are transmitted when a last frame fragment is ready to be transmitted. A response is received from the second node wherein non-forwarding neighboring nodes each set their NAV according to a value equal to the duration field of the response. The second node attempts forwarding of the TSQ frame fragments when acknowledgement of receipt of the TSQ frame fragments is complete.

Wireless Local Area Networks (WLANS) have become ubiquitous. Growth in demand for Wireless Local Area Networks (WLANs) is driving the development of new technology to provide higher throughput. To a greater extent this growth is due to the increased number of users and applications desiring wireless transmission and to a lesser extent to the emergence of new applications needing higher transmission rates along a single connection between two points.
In wireless Local Area Networks (LANs), a wireless channel can be reserved for the transmission of a single frame or of a sequence of frames, known as a TXOP (transmit opportunity), while employing asynchronous distributed random channel access methods, as described in the 2007 802.11 standard, which includes the 11e amendment, where the TXOP was introduced, the IEEE Std 802.11™-2007, (Revision of IEEE Std 802.11-1999), and the Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications.
In such an environment, both the source and destination of the transmission broadcast the reservation duration in order to establish an interference neighborhood. A TXOP is a sequence of frames transmitted between a pair of nodes following a single contention for the channel. A TXOP holder, the node initiating the TXOP, may transmit contention-free after the first transmission to the Responder, which is the node receiving the frames in the TXOP.
To date, there are two basic ways of reserving the channel for a TXOP in wireless LANs. One method of performing reservation is by utilizing frame-by-frame reservation. According to the 802.11 distributed channel access MAC protocol, RTS/CTS frames are used to notify neighbors of the start of the reservation. Alternatively, the first frame of a TXOP has its duration field set to a time interval long enough to reserve the channel for the transmission of the following frame. The reservation time is extended on a frame-by-frame basis, by updating the length of the reservation with each data frame and the acknowledgement that follows. A consequence of frame-by-frame reservation is that, if the reservation is denied, it does not require cancellation.
Another method of performing reservation in wireless LANS is by utilizing start-to-finish reservation. If it is not be possible to extend the time of channel reservation on a frame-by-frame basis, the channel must be reserved for the entire sequence of transmissions, from start to finish, at the time of the reservation request. If the reservation request is denied, or if time remains reserved at the completion of transmission, the reservation must be cancelled.
A start-to-finish reservation applies to any combination of nodes (i.e., mesh points/Access Points (APs)/stations). A node reserves a channel to cover an entire sequence of transmissions, directed to either one or various different destinations, possibly including responses from the destinations. If the reservation is not authorized, or when the transmission sequence is completed, the reserving node releases the remaining reservation time by canceling the reservation.
To avoid collisions, each node keeps a NAV for a traffic channel, which is set according to the received reservation requests and responses. A NAV is defined as a time period a node must refrain from transmitting on a traffic channel. It is maintained by each station and is updated by the Duration field value of received transmissions, which may serve as TXOP reservation requests or responses to reservation requests. A reservation request from the transmission source is either granted or denied by the destination, and notice is sent to the source. The response contains in the Duration field the remaining reservation duration in order to notify the neighbors of the destination node. Applications for wireless networks include Voice Over Internet Protocol (VoIP), and multimedia (Voice and/or Video), together referred to as VoIP/multimedia. VoIP/multimedia applications require a certain Quality of Service (QoS) in order to maintain sufficient quality of the communication. Latency can be an issue for VoIP/multi-media. Meeting QoS requires short total end-to-end over-the-air delays. The 802.11e amendment to the IEEE 802.11 standard, which is incorporated in the 2007 revision of the standard, provides mechanisms for reducing the over-the-air delays from transmissions in a wireless LAN. These are single hop transmissions. The 802.11e mechanisms may not be adequate for meeting latency requirements in wireless networks involving multiple-hop transmissions. Wireless mesh networks are such networks.
A wireless mesh may be an Ad hoc mode mesh (not attached to a wired network) or an infrastructure mode mesh (attached to a wired network). In general, both traffic with source and destination in the mesh and traffic bound from/to a wired network may co-exist on a mesh. The latency/jitter limit for voice traffic traversing the wired network is lower (40 to 50 milliseconds) than that for traffic staying on the wireless mesh (175-200 milliseconds). A mesh will involve multiple-hop flows. The mesh backbone network is a multi-hop network. The multi-hop path delay will be at least a multiple of the single hop delay. Wireless meshes operating on a single channel have novel collision behavior that can impact nearby the latency experienced end to end, over the air. The prevalence of hidden nodes and the interaction of contention-based access with multi-hop flows impose latency increases on both mesh and nearby WLANs beyond what non-mesh experience suggests. Hidden nodes remain hidden after retrial, and their transmissions are dropped. The high correlation of sequentially forwarded frames on a multi-hop flow cause excessive delays to transmissions that have been involved in a collision. For backward compatibility, and for the contention-based access protocol to continue to be used, remedies are needed on the mesh side. For QoS traffic, multi-hop delay must meet the same latency constraints as single-hop delay. There is thus a need for remedies to reduce over-the-air latency. The goal is to reduce the delay experienced on the longest multi-hop path by forwarding frames along a multi-hop path in an accelerated manner.
A frame may be fragmented into pieces small enough to pass over a link with a smaller Maximum Transmission Unit (MTU) than the original frame size. MTU refers to the size (in bytes) of the largest packet or frame that a given layer of a communications protocol can pass onwards. If a receiving host receives a packet which is fragmented, it has to reassemble the packet and hand it over to the higher layer. Reassembly always happens only in the receiving host. Fragmentation can cause excessive retransmissions when fragments encounter packet loss and reliable protocols such as TCP must retransmit all of the fragments in order to recover from the loss of a single fragment.

Method and apparatus performing express forwarding frames having multiple fragments


A coordinate input control method is used in a display-integrated coordinate input apparatus which includes a display having thereon a first area and a second area, and a single coordinate-input unit, and in which the coordinate input means inputs coordinates on the display. The method determines if the coordinates input by the coordinate input unit are on the second area. When it is determined that the input coordinates are on the second area, it is determined whether the coordinates on the second area have been consecutively input since processing on the first area. When it is determined that the coordinates have been consecutively input, designation of processing on the second area is nullified.

1. Field of the Invention
The present invention relates to coordinate input control in a display-integrated coordinate input apparatus which includes a display having a drawing area and an operation area thereon, and in which drawing and operation instructions are input on the display by using a single coordinate input unit.
2. Description of the Related Art
A display-integrated drawing input apparatus has been known which includes a display unit and a coordinate input mechanism (digitizer). The coordinate input mechanism uses the display unit, whose screen has a drawing area and an operation detecting area (hereinafter referred to as an "operation area"). The operation area is next to the drawing area and functions as operation switches.
When, in the above apparatus, the operation area on a side of the screen is constituted by a plurality of operation switch areas and is realized by an operation input unit identical to that in a digitizer, by mounting electronic components, such as tactile switches and connectors corresponding to various functions, on a printed circuit board, the large cost required to install wiring in the housing of the apparatus by using connecting cords can be saved. Accordingly, the mounting of the electronic components has an advantage in that the operation switch forming cost can be reduced.
In a case in which the screen of the display has the drawing area and the operation area at adjacent positions, as described above, when drawing is performed by means of drawing such as a user's finger or a drawing pen, if the means of drawing mistakenly protrudes from the drawing area into the operation area, it is determined that a switch operation has been designated, thus resulting in an operation mistake.
In addition, in many cases, the display-integrated drawing input apparatus employs a system in which a coordinate input unit of the digitizer emits infrared radiation almost in parallel to the surfaces of the drawing area and the operation area on the display unit and coordinate detection is performed by using infrared radiation reflected by the means of drawing such as the user's finger or drawing pen. In this system, after the means of drawing temporarily loses contact with the drawing area and the operation area, when an intended operation is performed again, a zone in which coordinate detection is performed by using the infrared radiation extends to a relatively broad region positioned away from the drawing area and the operation area. Thus, separation of the means of drawing cannot be detected, so that a state in which intended drawing and operation cannot be performed occurs.


A high power microscopy illumination system is disclosed, including a solid state illumination source. A diffusing collection lens having a diffusing surface is configured to collect and diffuse light emission from the solid state illumination source. An emitting surface is disposed substantially opposite the diffusing surface. An optical coupling element couples the light emission from the diffusing collection lens emitting surface along an optical axis to an optical output. The diffusing collection lens provides improved uniformity of illumination with direct coupling, without significant power loss.

Direct coupling of a high-brightness illumination source to a microscope potentially maximizes the optical coupling efficiency. Traditionally, an arc lamp is directly coupled to a fluorescence microscope by adjusting a collimating lens to achieve Koehler illumination. However, more modern light sources use a non-adjustable collimating optic, for example, the LDGI X-Cite series, which couples light indirectly through a liquid light guide and homogenizer, as described for example in U.S. Pat. No. 7,016,566. This type of light source is much simpler to use since it removes the need for periodic re-alignment required for traditional direct-coupled light sources. However, for direct coupling with a non-adjustable adaptor, the uniformity at the objective plane of an illumination source is a challenge for both lamp and LED light sources. For example, electrode structures on LEDs may be used to spread the current over the emitting area. These electrodes block light emission, causing undesirable optical non-uniformity.
One way to improve the uniformity of illumination is to insert a diffuser, with an appropriate diffusing grit, or with a fly eye lens array into the optical path. Typical diffusers come in the form of ground glass plates (but could also be coated glass or holographic glass). An ideal diffuser would scatter the light in a Lambertian pattern with zero loss. The amount of scatter or diffusion is determined by the "grit." Grit refers to the size of the sand particle used in sandblasting of the glass. In practice, the diffuser generally causes a significant decrease in the optical power coupled to the objective plane. This may not be an issue with powerful, high-intensity arc lamp sources. However, for LED sources, the power loss incurred may be unacceptable. Furthermore, a fly eye lens array is expensive, and is often not a cost-effective option for the majority of microscopy applications.
Thus, there is a need for improved or alternative microscopy illumination systems, particularly those based on solid-state light sources that address one or more of the above-mentioned problems.

Diffusing collection lens for direct coupled high power microscopy illumination systems


The present invention relates to crystalline R-guanidines of (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, its preparations and its use as therapeutic agents. More specifically the present invention relates to crystalline Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, preferably (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, its preparation and its use as therapeutic agent.

Coronary artery disease (CAD) is the major cause of death in type 2 diabetic and metabolic syndrome patients (i.e. patients that fall within the 'deadly quartet' category of impaired glucose tolerance, insulin resistance, hypertriglyceridaemia and/or obesity).
The hypolipidaemic fibrates and antidiabetic thiazolidinediones separately display moderately effective triglyceride-lowering activities although they are neither potent nor efficacious enough to be a single therapy of choice for the dyslipidaemia often observed in type 2 diabetic or metabolic syndrome patients. The thiazolidinediones also potently lower circulating glucose levels of type 2 diabetic animal models and humans. However, the fibrate class of compounds are without beneficial effects on glycaemia. Studies on the molecular actions of these compounds indicate that thiazolidinediones and fibrates exert their action by activating distinct transcription factors of the peroxisome proliferator activated receptor (PPAR) family, resulting in increased and decreased expression of specific enzymes and apolipoproteins respectively, both key-players in regulation of plasma triglyceride content. Fibrates, on the one hand, are PPARα activators, acting primarily in the liver. Thiazolidinediones, on the other hand, are high affinity ligands for PPARγ acting primarily on adipose tissue.
Adipose tissue plays a central role in lipid homeostasis and the maintenance of energy balance in vertebrates. Adipocytes store energy in the form of triglycerides during periods of nutritional affluence and release it in the form of free fatty acids at times of nutritional deprivation. The development of white adipose tissue is the result of a continuous differentiation process throughout life. Much evidence points to the central role of PPARγ activation in initiating and regulating this cell differentiation. Several highly specialised proteins are induced during adipocyte differentiation, most of them being involved in lipid storage and metabolism. The exact link from activation of PPARγ to changes in glucose metabolism, most notably a decrease in insulin resistance in muscle, has not yet been clarified. A possible link is via free fatty acids such that activation of PPARγ induces Lipoprotein Lipase (LPL), Fatty Acid Transport Protein (FATP) and Acyl-CoA Synthetase (ACS) in adipose tissue but not in muscle tissue. This, in turn, reduces the concentration of free fatty acids in plasma dramatically, and due to substrate competition at the cellular level, skeletal muscle and other tissues with high metabolic rates eventually switch from fatty acid oxidation to glucose oxidation with decreased insulin resistance as a consequence.
PPARα is involved in stimulating β-oxidation of fatty acids. In rodents, a PPARα-mediated change in the expression of genes involved in fatty acid metabolism lies at the basis of the phenomenon of peroxisome proliferation, a pleiotropic cellular response, mainly limited to liver and kidney and which can lead to hepatocarcinogenesis in rodents. The phenomenon of peroxisome proliferation is not seen in man. In addition to its role in peroxisome proliferation in rodents, PPARα is also involved in the control of HDL cholesterol levels in rodents and humans. This effect is, at least partially, based on a PPARα-mediated transcriptional regulation of the major HDL apolipoproteins, apo A-I and apo A-II. The hypotriglyceridemic action of fibrates and fatty acids also involves PPARα and can be summarised as follows: (I) an increased lipolysis and clearance of remnant particles, due to changes in lipoprotein lipase and apo C-III levels, (II) a stimulation of cellular fatty acid uptake and their subsequent conversion to acyl-CoA derivatives by the induction of fatty acid binding protein and acyl-CoA synthase, (III) an induction of fatty acid β-oxidation pathways, (IV) a reduction in fatty acid and triglyceride synthesis, and finally (V) a decrease in VLDL production. Hence, both enhanced catabolism of triglyceride-rich particles as well as reduced secretion of VLDL particles constitutes mechanisms that contribute to the hypolipidemic effect of fibrates.
A number of compounds have been reported to be useful in the treatment of hyperglycemia, hyperlipidemia and hypercholesterolemia (U.S. Pat. No. 5,306,726, PCT Publications nos. WO 91/19702, WO 95/03038, WO 96/04260, WO 94/13650, WO 94/01420, WO 97/36579, WO 97/25042, WO 95/17394, WO 99/08501, WO 99/19313 and WO 99/16758).

Crystalline R-guanidines, Arginine or (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H -phenoxazin-10-yl)ethoxy]phenyl}propanoate


A method, system and device for addressing the reduction of snoring includes a removable or dissolvable strip of material that adhere to mucosal tissue of a person's soft palate to provide stiffening support therefore, thus reducing the occurrence of vibration of such tissue during sleep. Preferred embodiments include of a specially textured surface, either one both or at least the outer side of an adhesive strip (the side facing away from the mucosal tissue to which it is attached) that has anti-microbial characteristics, bioluminescent expressions, etc. and a surface topography that resists bioadhesion of undesired bacteria that are typically present in a human's mouth.

Snoring is a problem suffered by a large number of people. Snoring, upper airway resistance syndrome and obstructive sleep apnea syndrome (OSAS) are all breathing disorders related to narrowing of the upper airway during sleep. Individuals over age 65 experience such sleep difficulties, and the prevalence of sleep problems will therefore increase as the over-65 population increases. Each year, sleep disorders, sleep deprivation, and excessive daytime sleepiness add billions of dollars annually to the cost of health care and in lost productivity. When the muscles at the base of the tongue and the uvula (the small fleshy tissue hanging from the center of the back of the throat) relax and sag, the relaxed tissues may vibrate as air flows past the tissues during breathing, resulting in snoring. Snoring affects about half of men and 25 percent of women—most of whom are age 50 or older.
Snoring is a common chronic medical problem that is associated with episodic partial upper airway obstruction during sleep. Snoring afflicts millions of people worldwide. Snoring can lead to chronic fatigue that follows sleep deprivation and is considered by many to be a serious medical problem. The sound of snoring is produced by turbulent air-flow moving through an area of partial upper airway obstruction that produces resonant vibrations in the soft tissues adjacent to the upper airway. In many cases, snoring is caused by the relaxation of the tongue and the resulting blockage of the breathing airway. When the tongue of the sleeping individual relaxes and creates such a blockage and the individual subsequently forcibly passes air through the breathing airway, loud vibrations between the tongue and surrounding tissues will often result in the noises commonly referred to as snoring. Snoring is created by the vibration of the pharyngeal soft tissues as air passes through an airway that is too small to allow for smooth, unimpeded flow.
A percentage of those who snore also suffer from sleep apnea. The most common type of sleep apnea, obstructive sleep apnea (OSA), is caused by repeated collapse of soft tissues forming the walls of the upper airway in the sub-glottal region during sleep. Currently accepted treatment for OSA typically includes continuous positive airway pressure (CPAP). CPAP, as currently practiced, involves connection of a pressurized air delivering device to the mouth or nose of the patient. This device typically is connected to a pressurized air source in the form of a compressor or tank with a regulator. These pressurized air supplies are expensive, large, and noisy. Because body position and sleep stages vary throughout the night, the CPAP mask pressure often does not remain constant. To address this problem, many sleep clinicians select a sufficiently high pressure setting to ensure that respiratory disturbances are reliably inhibited even in the least favorable situations. Unfortunately, this necessitates a needlessly high mask pressure for periods during which it is not required. Furthermore, the high mask pressure may make CPAP uncomfortable. Variable patient compliance remains a significant problem. Studies have found that up to 25% of patients discontinue CPAP therapy.
Airway dryness may also contribute to CPAP discomfort. The high flow rates used during CPAP may overwhelm the capacity of the nasal mucosa to heat and humidity inspired air. Compounding this problem is a phenomenon known as mouth leak. Mouth leak occurs during approximately one-third of total sleep time in people who suffer from dryness of the nose and throat. It results from the mouth being partially or fully open during nasal CPAP therapy. During mouth leak, a portion of air bypasses the nasal membranes and exits via the mouth. Normally, expiratory air releases heat and water back into the nasal mucosa by condensing on the cooled mucosal surface. Leaked air is not conditioned in this way, and results in intensification of the excessive dryness experienced during the use of CPAP. To compensate for the decreased heat and humidification caused by moth leak, blood vessels in the nose dilate; however, their capacity to do so may be overwhelmed by the high flow rates produced by CPAP. As the patient continues to mouth leak, further moisture is lost and blood vessels continue to dilate, thereby narrowing the airway. The net result of this process is increased nasal resistance and nasal congestion.
It is known that such snoring can be alleviated by displacing the individual's lower jaw into a position that is relatively forward of its normal position. A variety of known devices are designed to forwardly displace an individual's lower jaw while they are sleeping to thereby alleviate snoring. Brace-like bite splints of this type for preventing snoring serve to move the mandibula slightly forwards, since in this position of the mandibula the respiratory tracts are opened wider, enabling a person to breathe more freely without snoring. Some appliances hold the lower jaw forward during sleep while others affect tongue position. Oral appliances relieve OSAS and snoring by realigning the jaw and/or tongue in relation to the head. Oral appliance therapy, while increasingly popular to treat selected cases of sleep disordered breathing, is not completely effective in all situations.
Oral appliances can be categorized generally into three types based on design. The first type mechanically lifts the soft palate. The effectiveness of this appliance type is presumed to be due to a prevention of collapse at the velopharyngeal level. The second type positions the tongue anteriorly while the mandible retains its customary relation to the maxilla. Some oral appliances of this type use a suction cup; others are designed to work through nocturnal neuromuscular training. Most oral appliances are of the third type—mandibular advancement appliances—which, as the name implies, advance the mandible. Because the mandible is the attachment for the genioglossus and other tongue muscles, the tongue moves anteriorly, as it does with the second type. The mechanism of action of the second and third of these oral appliance designs is to enlarge the hypopharyngeal airway by moving the base of the tongue farther from contact with the posterior wall of the pharynx, thereby reducing the likelihood of collapse from inspiration.
Nasal sprays mainly work as a snoring remedy for those who suffer from nasal blockage. Snoring caused by problems with the uvula or soft palate (as most snoring problems are) are not resolved by the use of, nasal sprays or nasal passage opening devices.
U.S. Pat. No. 5,465,734 to Snorex, Inc discloses a tongue retaining device formed of a flexible polyvinyl material and hollow interior that fits over the tongue and requires a specialist to take upper and lower jaw impressions of the patient to produce a tailored device for the patient.
Numerous attempts have been made towards treating OSA and snoring. These include placing implants in either the tissue of the soft palate or the pharyngeal airway as disclosed in
U.S. Pat. No. 6,250,307 to Conrad et al. and U.S. Pat. No. 6,431,174 to Knudson et al. After implantation, tissue grows into the attachment ends and a bioresorbable member resorbs after tissue in-growth, causing tissue contraction, which results in a debulking of the tissue and movement of tissue away from opposing tissue surfaces in the pharyngeal upper airway.
Physicians often treat minor snoring by recommending that patients take simple measures such as increasing exercise, losing weight, decreasing alcohol consumption, reducing smoking, altering sleeping position, and using dental or nasal appliances. Although these relatively simple measures can be somewhat effective, many patients do not experience satisfactory relief from snoring. As a result, for many patients the only alternative is surgery.
One of the earliest surgical procedures developed, which is still in use today, is uvulopalatopharygoplasty. In addition to the poor success rates of this expensive procedure, various complications were common, including serious postoperative bleeding, pain, velopharyngeal incompetence, palatal dryness, nasopharyngeal stenosis, long-term voice changes and partial loss of taste.
Other palatal stiffening procedures, called radio frequency ablation (RFA), have been employed with mixed results, where radio frequency energy is delivered to the soft palate to cause scarring of the palatal muscle. Unfortunately, RFA must be performed multiple times to obtain satisfactory results.
In U.S. Pat. No. 5,988,171 to Sohn et al., suture material is placed around a base of the tongue and secured to the jaw, thereby moving the tissue of the base of the tongue away from the opposing tissue of the pharyngeal airway. This procedure, referred to as tongue suspension, is uncomfortable. Another technique described in U.S. Pat. No. 5,843,021 to Edwards et al., includes applying radio frequency ablation to either the tongue base or of the soft palate to debulk the tissue of the tongue or palate, respectively.
Other snoring remedies involve the injecting of a microparticle solution into a patient's soft palate to stiffen the soft palate, thereby stiffening the soft palate with the injected composition to reduce palatal flutter.
Unfortunately, all current treatments produce results that are far from optimal. Surgery and re-positioning devices are effective in only a minority of OSA patients and many people are subjected to painful and expensive procedures without benefit. While CPAP is effective in many situations, the treatment is uncomfortable and not well tolerated during long-term use. A substantial number of patients given CPAP discontinue therapy within the first year after initiation. Surgical procedures to remedy snoring are expensive, painful, and of dubious long-term benefit.
There is a long-felt but unsolved need for a simple, effective, inexpensive non-surgical method and device for treating snoring, especially one that does not rely upon uncomfortable mouth or tongue repositioners or the use of continuous positive airway pressure machines.
To date, nonsurgical approaches to the management of OSAS include behavioral modification, drug therapy, continuous positive airway pressure (CPAP), and use of mechanical devices. Behavioral modifications include avoidance of alcohol and sedative medications, alteration of sleep position, avoidance of sleep deprivation, and weight loss.

This patent is subject to a terminal disclaimer.

Buccal bioadhesive strip and method of treating snoring and sleep apnea


A multilayered torsional hinged mirror assembly that includes a drive/sensing permanent magnet. To allow for permanent magnets having increased thicknesses, a hinge plate of the mirror defines a recess for receiving the permanent magnet. The recess may be etched completely through the hinge plate such that the permanent magnet is bonded to the back side of the mirror layer, or alternately may extend part way through the hinge plate to allow the permanent magnet to be mounted to the bottom of the recess. In both embodiments, the center of mass of the mirror assembly can be adjusted to lie on the pivoting axis of the mirror assembly by selection of the depth of the recess and the shape and mass of the permanent magnet.

Pivoting or oscillating torsional hinged mirrors provide a very effective, yet inexpensive replacement for spinning polygon shaped mirrors used in printers and some displays. As will be appreciated by those skilled in the art, many of the torsional hinged mirrors are MEMS type mirrors etched from a silicon substrate by processes similar to that used in the manufacturing of semiconductor devices. Early versions of the torsional hinged mirrors for providing a raster type scan for printing and displays required speeds of about 3 KHz. Multilayer mirrors that operate in this speed range or slower could be manufactured with a drive/sensing magnet that was readily mounted or bonded to the back side of the hinge plate or layer. Further, the size and shape of the permanent magnet could readily be selected such that the moment of inertia of the magnet balanced the moment of inertia of the mirror layer. Balancing the mirror layer and the permanent magnet on either side of the hinge plate or layer results in the mass center of the mirror assembly lying on the pivoting axis of the mirror. However, as the demand for higher and higher oscillating speeds has resulted in smaller and smaller mirror assemblies, the corresponding requirement of smaller permanent magnets has resulted in problems in manufacturing magnets sufficiently reduced in size.
More specifically, presently available manufactured disc shaped permanent magnets have a minimum diameter of about 0.50 mm and a length or depth of about 0.20 mm. Although, these dimensions are very small, the moment of inertia of a magnet the size is still greater than the moment of inertia of the mirror layer of the smaller high speed mirrors. Therefore, when these small magnets are mounted to the back side of the hinge plate or layer, they are still too large such that the center of the mass moment of the assembled mirror device does not lie on the pivoting axis. This unbalanced assembly is unacceptable.
Therefore, a method of fabricating a small high speed mirror assembly with the mass moment center of the assembly located on the pivoting axis of the assembly would be advantageous.

Multilayer torsional hinged mirror with a recessed drive/sensing permanent magnet


An outboard motor control system includes a plurality of outboard motors, a vibration detecting section, and a control section. The outboard motors are mounted on a stern of a watercraft. Each of the outboard motors includes a propeller. The outboard motors are configured to be steered independently of one another. The vibration detecting section is configured to detect a vibration of the outboard motors. The control section is configured and programmed to execute a vibration suppression control when the vibration detecting section detects a vibration of the outboard motors. With the vibration suppression control, the control section is configured and programmed to change a propeller rotational axis direction and/or a propeller position of at least one of the outboard motors.

1. Field of the Invention
The present invention relates to a control system for an outboard motor.
2. Description of the Related Art
There are conventional watercrafts in which a plurality of outboard motors are installed on a stern of the watercraft and the outboard motors are coupled together with a rod-shaped device called a tie bar. In such a watercraft, steering angles of the outboard motors are changed in a coordinated manner. Conversely, Laid-open Japanese Patent Application Publication No. 2007-083795 and Laid-open Japanese Patent Application Publication No. 2006-199189 disclose watercrafts in which a plurality of outboard motors are not coupled with a tie bar and, instead, steering angles of the outboard motors are controlled individually. More specifically, in the watercraft disclosed in Laid-open Japanese Patent Application Publication No. 2007-083795, the steering angles of the outboard motors are set according to a traveling performance mode selected by a helmsperson. In the watercraft disclosed in Laid-open Japanese Patent Application Publication No. 2006-199189, target steering angles for a port side outboard motor and a starboard side outboard motor are set individually based on a rotation angle of a steering wheel and an engine rotational speed.


An amplifier circuit includes a grounded-collector circuit for converting an input signal voltage into a first signal current, a second transistor circuit for transmitting the first signal current to an output side, a variable impedance for converting the first signal current transmitted to the output side into a voltage, and a circuit block having a voltage generation circuit connected in series to the variable impedance. A transistor constituting the grounded-collector circuit has a collector connected to a junction of the voltage generation circuit and the variable impedance and an emitter connected to an input side of the second transistor. The amplifier circuit has an operation point in which input and output voltages are maintained constant even if a gain is varied.

The present invention relates to an amplifier circuit and more particularly, to a variable gain circuit, a wideband circuit and a gain control circuit suitable for a video amplifier circuit for a CRT display.
A conventional video amplifier circuit for a color CRT display is shown in FIG. 3. In the circuit shown in FIG. 3, video signals for the three primary colors of R(red), G(green) and B(blue) are applied from signal sources 1R, 1G and 1B through video amplifier circuits 2R, 2G and 2B to cathodes 3R, 3G and 3B of a CRT display 4, respectively. The CRT 4 includes a first grid 40 shared by the signals of the three primary colors RGB.
Since the conventional amplifier circuits for the three primary colors have the same circuit configuration, description of the operation of only the amplifier circuit for the red color R is being presented for purposes of explanation. An input signal voltage V.sub.IR is applied to a base of a transistor 22R constituting a grounded-emitter amplifier circuit and is amplified by the transistor so that an inverted output signal voltage V.sub.OR is produced at its collector and is supplied to the cathode 3R of the CRT 4, An operation point of the output signal voltage V.sub.OR in this case is adjusted by using a variable resistor 27R for adjustment of cut-off, and a voltage gain is adjusted by using a variable resistor 23R for adjustment of drive. A range of adjustment for the operation point of the output signal voltage is limited by a resistor 26R. A resistor 24R limits the voltage gain adjustment range in the same manner as the resistor 26R and also compensates for the frequency characteristic of the video amplifier circuit 2R at the same time. The frequency band of the video amplifier circuit 2R is mainly limited by a load capacitance 30 and a collector resistor 21R and is 1/(2.pi.C.sub.LR R.sub.CR) when the frequency characteristic is not compensated for. The frequency characteristic is improved in excess of the frequency determined by a time constant defined by the resistor 24R and an emitter peaking capacitor 25R added to suppress the band limitation. However, the upper limit of the frequency band increased by the improved frequency characteristic is reduced in inverse proportion to increase of a signal amplitude.
Adjustment of the white balance in the prior art is attained by repeatedly performing the cut-off adjustment of the primary color circuits and the drive adjustment of the video amplifier circuit for at least two primary colors.
An example of a conventional wideband circuit is now shown in FIG. 14. The circuit shown in FIG. 14 is named a cascode amplifier circuit and is advantageous in that the Miller effect occurring in a grounded-emitter transistor 22 of a first stage is suppressed. More particularly, with a mere grounded-emitter configuration, a collector voltage of the transistor 22 is swung to a voltage gain Av times a base voltage in an inverted direction. Generally, a signal source 1 is regarded as a series circuit of a signal voltage source 1v and a signal source resistor 1r. Accordingly, an input capacitance of a base terminal of the transistor 22 is substantially equal to a value of (1+Av) times a value C.sub.BC2 of a capacitance 210 between the base and the collector thereof and a time constant on the side of the input terminal determined by the capacitance value of the base terminal and a value rs of the signal source resistor 1r is increased so that the frequency band of the circuit is narrowed. Thus, as shown in FIG. 14, the load of the grounded-emitter circuit is formed by a grounded-base circuit having a low input impedance and constituted of a transistor 208, so that a signal voltage appearing at the collector of the transistor 22 is suppressed. The input capacitance of the base terminal of the transistor 22 is a sum of the capacitance C.sub.BC2 and an equivalent capacitance of a circuit including resistors 23 and 24 and a capacitor 25 connected to the emitter of the transistor 22 reflected to the base side of the transistor 22 through the transistor 22 and is a small value to an extent that the frequency characteristic is not adversely affected. Accordingly, the cascode amplifier circuit shown in FIG. 14 is widely applied to the video amplifier circuit and various wideband circuits including an integrated circuit as a circuit capable of spreading the frequency band sufficiently. In FIG. 14, a terminal 212 is an output terminal.
A wideband variable gain amplifier circuit is shown in FIG. 25A. In FIG. 25A, a signal current 98 converted by a transistor 92 and a resistor 97 from a voltage is divided by a fixed ratio set in transistors 93 and 94 constituting a differential pair to vary a gain. Thus, a signal Vi of an input signal source 1 is amplified and is outputted at output terminal 95 as output signal Vo. The division ratio in this case is constant regardless of a magnitude i.sub.s of the signal current 98 but, however, can be varied by adjusting a voltage .DELTA.V.sub.B of a differential pair control voltage source 9. Further, since the transistors 93 and 94 are configured as a grounded-base circuit in series connection with a grounded-emitter circuit constituted of the transistor 92, the circuit of FIG. 25A is considered to constitute a cascode amplifier circuit and can attain the wideband characteristic.
Adjustment process of the white balance in the prior art is described with reference to an input and output characteristic diagram, of a video amplifier circuit, shown in FIG. 4. In the characteristic diagram of FIG. 4, the abscissa represents an input signal voltage V.sub.I and the ordinate represents an output signal voltage V.sub.o. A straight line 50 shown by a solid line represents an input and output characteristic in the case where the white balance to be targeted is ensured.
In the current adjustment of the white balance, the cut-off adjustment and the drive adjustment are made in the state where input signal voltages of FIG. 4 are V.sub.IC V.sub.ID. If it is assumed that the video amplifier circuit has the characteristic shown by a broken line 51 at an initial state thereof, the output voltage V.sub.o is mainly shifted as shown by an arrow 52 by performing a first cut-off adjustment, so that the characteristic is shifted as shown by broken line 53. Adjustment of the voltage gain is made as shown by an arrow 54 in a next drive adjustment, so that the characteristic shown by a broken line 55 is obtained and a first adjustment of the white balance is finished. However, as apparent from an arrow 56 of FIG. 4, there is a problem that the precedingly performed cut-off adjustment is additionally shifted by the drive adjustment. Such interference between the cut-off adjustment and the drive adjustment in the prior art is now analyzed quantitatively. The video amplifier circuit for the red color R shown in FIG. 3 is taken up as a circuit example. When an output voltage at the time of the cut-off adjustment is V.sub.OCR, and V.sub.0 =V.sub.OCR, V.sub.1 =V.sub.CC, V.sub.2 =V.sub.ICR, V.sub.3 =V.sub.BE22R, V.sub.4 =V.sub.ER, R.sub.1 =R.sub.CR and R.sub.2 =R.sub.ER, the output voltage can be expressed as follows: ##EQU1## where V.sub.BE22R : voltage between the base and the emitter of the transistor 22R; and
V.sub.ER : emitter equivalent voltage ##EQU2## R.sub.ER : emitter equivalent resistance EQU R.sub.ER .apprxeq.(R.sub.23 +R.sub.24)//{(R.sub.26 +(R.sub.1R //R.sub.2R)}(3)
where R.sub.1 //R.sub.2R represents a parallel resistance value (R.sub.1R.R.sub.2R /(R.sub.1R +R.sub.2R)) of resistances R.sub.1R and R.sub.2R, and a parallel resistance value is hereinafter expressed thereby similarly.
Further, when a voltage gain set by the drive adjustment is A.sub.VR, the voltage gain is represented by ##EQU3##
From the foregoing, it would be understood that the resistances R.sub.1R and R.sub.2R Set in the cut-Off adjustment and the resistance R.sub.23 set in the drive adjustment exist together in the equations of V.sub.ER and R.sub.ER and the respective effects are preserved without canceling each other. Accordingly, since there is interference between the cut-off adjustment and the drive adjustment in the prior art, there is a problem that the adjustment of the white balance is not completed unless these adjustments are made repeatedly.
An example of the frequency characteristic at the input terminal of the cascode amplifier circuit of FIG. 14 is shown in FIG. 15. In the characteristic diagram of FIG. 15, the abscissa represents a signal frequency fs and the ordinate represents an amplitude .vertline.V.sub.B .vertline. of a signal at the base electrode of the transistor 22 which is an input terminal. As shown by a characteristic curve 213 of FIG. 15, a trap occurs in a frequency fr lower than a cut-off frequency f.sub.CB determined by the resistance r.sub.s of the signal source and the capacitance C.sub.BC2 between the base and the collector of the transistor 22. In order to make clear the cause for the occurrence of the trap, the transistors 208 and 22 are expressed by a hybrid .pi.-shaped equivalent circuit shown in FIG. 16 for analysis. In FIG. 16, r.sub.bb represents an inter base resistance, r.sub.E an emitter bulk resistance, r.sub..pi. an operation resistance between the base and the emitter, C.sub..pi. a diffusion capacitance, C.sub..mu. a capacitance between the base and the collector, C.sub.o a capacitance between the collector and the emitter, and g.sub.m a mutual conductance.
(1) An input impedance Z.sub.E as viewed from the emitter electrode of the grounded-base transistor 208 exhibits the inductivity as expressed by the following equation (5), where .beta..sub.0 is a low-frequency current amplification factor. ##EQU4##
(2) An input impedance Z.sub.B of the grounded-emitter transistor 22 is proportional to a series impedance of a parallel capacitance C.sub..mu. and C.sub.O and a load impedance Z.sub.C connected to the collector electrode as shown in the following equation (6): ##EQU5##
(3) From the above equations (1) and (2), it is considered that the trap occurs by a series resonance of an impedance component of the input impedance Z.sub.E of the transistor 208 and a parallel combined capacitance of the capacitance 210 between the base and the collector and a capacitance 211 of the collector and the emitter of the transistor 22. It has been confirmed by an experiment that the trap occurs in the vicinity of a resonance frequency fr expressed by the equation (7 ). However, all parameters of the equivalent circuit of the transistor in the equation (7) are values concerning the transistor 208. ##EQU6##
Since a waveform distortion occurs in the vicinity of the frequency fr in which the trap occurs, there is a problem that there is a case where the cascode amplifier circuit must suppress the frequency band at the sacrifice of its feature.
The temperature characteristic of the gain of the variable gain amplifier circuit shown in FIG. 25A will now be considered. The gain is proportional to the division ratio of the signal current 98 flowing through the transistors 93 and 94 constituting the differential pair, that is, a ratio i.sub.e1 /i.sub.e2 of emitter currents 290 and 291 and can be expressed as shown by the following equation (8): EQU i.sub.e1 /i.sub.e2 .apprxeq.1/{1+exp(q.DELTA.V.sub.B /kTj)}(8)
where g is an amount of electron charges, k is the Bolzmann constant, and T.sub.j is a temperature of the junction of the transistors 93 and 94.
Accordingly, in order to obtain a fixed gain, it is necessary to vary a temperature coefficient .differential..DELTA.V.sub.B /.differential.T.sub.j for a voltage .DELTA.V.sub.B of a differential pair control voltage source 9 in accordance with .DELTA.V.sub.B as shown by the characteristic 293 of FIG. 25B. A variation amount of the junction temperature T.sub.j is equal to a variation amount of the ambient temperature of the transistors 93 and 94. Accordingly, if the voltage .DELTA.V.sub.B is constant regardless of the ambient temperature, the ratio i.sub.e1 /i.sub.e2 of the divided currents is drifted toward 1 with the increase of the ambient temperature.

Amplifier circuit having an operation point maintaining input and output voltages constant even if a gain thereof is varied


A method of predicting the lymphotrophic metastatic potential of a solid non-lymphoid tumor. The percentage of cells of each of a plurality of representative samples of the tumor which express lymphoid gene products is determined. The metastatic potential is predicted to be low when no tumor cells in all of the samples are detected to express lymphoid gene products. The metastatic potential is predicted to be high when a high percentage of tumor cells in at least one of the samples are detected to express lymphoid gene products. Expression of SYKB in any of a plurality of samples of a primary colon tumor is indicative that the primary colon tumor has lymphotrophic metastatic potential.

Metastasis or the spread of primary tumor cells to a secondary organ is a complex process involving a cascade of steps (Paget, S., 1889, Lancet, 1:571-573, Fidler, I. J., 1990, Cancer Res. 50:6130-6138). Neoplastic transformation usually results in the dedifferentiation of pre-malignant cells. Consequently, there is a loss of cell-to-cell adhesiveness and a detachment of tumor cells from the primary tumor bed. However, detachment does not ensure the spread of primary tumor cells to distant sites, since tumor cells must also acquire migratory capability to invade a secondary organ (Fidler, I. J., Kripke, M. L., 1977, Science 197:893-895). More specifically, tumor cells must have target specific motility and preferential chemotaxis to direct them toward either blood vessels (hematogenous metastasis) or lymphatics (lymphotrophic metastasis) (Willis, R A. 1972. 3rd Edit. London: Butterworth). It is our hypothesis that primary tumor cells may become metastatic by acquiring the phenotypic properties of migrating T lymphocytes. Once they acquire this invasive phenotype, these T cell "like" solid tumor cells can either be swiftly carried away by blood flow or may roll through lymphatic channels (Imhof, B. A., Dunon, D., 1995, Adv. Immunol. 58:345-416). Migration of tumor cells is promoted by specific receptor/ligand interactions between the tumor cells and cells lining the endothelium of secondary sites (Weiss et al., 1988, FASEB J. 2:12-21; McCarthy et al., 1991, Sem. Cancer Biol. 2:155-167) where arrest and adhesion of tumor cells occurs. Here the tumor cells may die, become dormant, or invade the organ's parenchyma where they proliferate and undergo homeotypic aggregation (Yefenof et al., 1993, Proc. Natl. Acad. Sci. 90:1829-33; Cohen et al., 1995, In: NK Cells in the Liver, Bouwens L, ed. RG Landes Biomedical Publication, Austin, CRC Press. Pp. 71-100). Tumor cells use growth factors produced by the tumors themselves (autocrine) or by cells from the secondary organs (paracrine) for colony growth and survival (Radinsky, R., 1992, Cancer Metas. Rev. 12:345-361).
In accordance with this specification and claims, tumor cells may be classified as benign if they have not invaded surrounding tissue and malignant if they have done so, and malignant tumor cells may be classified as having metastatic potential if they have the capacity to spread through the lymph or blood systems to distant sites and to have non-metastatic potential if they do not have such capacity. If metastatic cells have the capacity to spread through the lymph system, they are defined herein and in the claims as having "lymphotrophic" metastatic potential. A "primary" tumor is defined, for the purpose of this specification and the claims as one which is located at its site of origin, i.e., before any metastasis thereof, as contrasted with a "secondary" tumor, which is a tumor located at a site to which the primary tumor has metastasized.
Metastasis presents a cancer clinician with great difficulty in diagnosing and treating the malignant tumor because (i) metastasis may comprise as little as one or a few cells thereby evading clinical diagnosis even with modern techniques; (ii) often metastasis has already been seeded by the time a patient is diagnosed with a malignant non-lymphoid solid tumor (Silverberg et al., 1989, CA Cancer J. Clin. 39:3-21); (iii) treatment is more complex than simple surgical excision of the primary tumor; (iv) systemic therapy for metastatic non-lymphoid solid tumors, such as renal cell carcinoma (Rosenberg et al. 1985, N. Engl. J. Med. 313:1485-1492) remains ineffective with little survival advantage; and (v) not all malignant tumors have the same metastatic potential and no direct relationship has been established in determining whether any particular carcinoma will develop metastasis.
Monoclonal antibodies (Mab) have been used to characterize and classify T cell surface molecules such as the clusters of differentiation (CD) of human leukocyte antigens. As illustrated in FIG. 1, the T cell receptor (TCR), illustrated at 20, is an integral membrane protein, expressed on the surface of T lymphocytes, illustrated at 22, occurring as a disulfide linked heterodimer that is non-covalently associated with CD3 chains, illustrated at 24. TCR has been linked to autoimmune disease and anti-TCR antibodies have shown therapeutic potential for treating autoimmune disease (Basi et al., 1992, J. Immunol. Meth. 155:175-191). In some cancers, a correlation exists between an increase in concentration of the TCR associated CD8 molecule in the serum of children with non-Hodgkins lymphoma and the stage of the disease and its responsiveness to therapy (see U.S. Pat. No. 5,006,459).
Several studies have shown that T cell-associated molecules (Omar et al. 1991, AIDS 5:275-281, Kawami et al., 1993, Biotherapy 6:33-39; McMillan et. al. 1995, Int. J. Cancer 60:766-772) are expressed on the surface of non-lymphoid solid human tumor cells. SW620, a metastatic human colon tumor-derived from the lymph node of a 51-year-old male has been shown to possess the TCR co-receptor CD4 on its surface by several different methods including Northern analysis and FACS (Omary et al 1991. AIDS 5:275-281). To date, no one has directly identified Vβ sequences on the surface of carcinoma cells.

Methods for identifying or diagnosing carcinoma cells with metastatic potential based on the measurement of lymphoid genes or their products in carcinoma cells


A method of arranging mask patterns, which includes a first mask has a first mask pattern, a second mask has a second mask pattern. The distance between the first mask boundary and the first mask pattern boundary is different form the distance between the second mask boundary and the second mask pattern boundary.

1. Field of the Invention
The present invention relates to a method of arranging mask patterns, more particularly, to a method of arranging several mask patterns have different corresponding positions with lenses to lessen the lens mura of the panel.
2. Description of the Prior Art
In an exposure process, a light source of a scan exposure apparatus produces exposure light, like i-line, KrF, ArF, etc. The light passes through a mask and a projection lens to project on a photoresist of a semiconductor wafer or a glass substrate. The circuit pattern on the mask is transferred to the planned section of the substrate (called "a scan") to be a hard mask of the etching or the ion implanting. Then, the plate stage or the mask stage of the scan exposure apparatus moves toward the next position and repeats the same exposure, and the pattern of the mask is transferred to the photo-resist of the whole substrate step by step.
Recently, the size of LCD and PDP monitors have become bigger and bigger, and the size of the mask have become bigger, too. Therefore, the lenses of the recent exposure apparatus are combined by a plurality of lenses. The pattern of the mask is transferred to the glass substrate in the ratio of 1:1. However, every lens has a slight difference, lenses have overlapping sections, or the projection lenses have a precision bias after a long period of use.
Please refer to FIG. 1. FIG. 1 is schematic diagram of a corresponding position of a mask pattern and a lens of an exposure apparatus according to the prior art. The five masks in FIG. 1 are the exposure masks in the general TFT LCD manufacture process. The five masks are individually the gate electrode (GE) mask I, the semiconductor (SE) mask II, the source/drain (SD) mask III, the contact hole(CH) mask IV, and the pixel electrode (PE) mask V. Each of them has a corresponding mask pattern 102, 104, 106, 108, and 110 on the center of the masks I, II, III, IV, and V. All of the five masks I, II, III, IV, V have the width of L, and the mask patterns 102, 104, 106, 108, 110 have the width of I respectively.
Please note that, lenses of the exposure apparatus usually have n lenses, and the lens and the adjacent lens intercross and have a lens overlapping section. Hence, FIG. 1 illustrates the masks I, II, III, IV and V in the exposure apparatus, the corresponding position of each lens overlapping section 112, 114, 116, 118 and 120, the mask patterns 102, 104, 106, 108 and 110, and the masks I, II, III, IV and V. The distances of the mask patterns 102, 104, 106, 108 and 110 with the lens overlapping sections 112, 114, 116, 118 and 120 are z. The distance of the boundary of the masks I, II, III, IV and V with the boundary of the mask patterns 102, 104, 106, 108 and 110 are A for clear illustration in the prior art. But, the distance of the boundary of the mask and the boundary of the mask pattern isn't a fixed width in real manufacture.
Please refer to FIG. 2. FIG. 2 is a schematic diagram of photoresist patterns after exposure of the mask patterns of FIG. 1. FIG. 2 continues the condition of FIG. 1. Photoresist layers I′, II′, III′, IV′, and V′ are the schematic diagrams of the masks I, II, III, IV and V exposure on the glass panel. That means following the process of the scanning exposure apparatus, one section of the glass panel will be exposed by the masks I, II, III, IV and V in sequence. Therefore, in FIG. 2, the photoresist layers I′, II′, III′, IV′, V′ and the photoresist patterns 202, 204, 206, 208, 210 individually show the diagrams of the masks I, II, III, IV, V and the mask patterns 102, 104, 106, 108, 110 exposed on the glass panel.
As an example of the ratio 1:1, after completing many PEPs (photo-etching-processes), the width of the photoresist layers I′, II′, III′, IV′, V′ are L, and the width of the photoresist patterns 202, 204, 206, 208, 210 are I. The distances of the boundaries of photoresist layer I′, II′, III′, IV′, V′ and the boundaries of photoresist patterns 202, 204, 206, 208, 210 are A as the distance of the boundaries of the masks I, II, III, IV, V and the boundaries of the boundaries of the mask patterns 102, 104, 106, 108, 110. The distances of the photoresist patterns 202, 204, 206, 208, 210 with the lens sections 212, 214, 216, 218, 220 are z as the distance of the mask patterns 102, 104, 106, 108, 110 with the lens overlapping sections 112 , 114, 116, 118, 120. Finally, every lens section 212, 214, 216, 218, 220 is in the same position of the photoresist layer I′, II′, III′, IV′, V′.
Please refer to FIG. 3. FIG. 3 is schematic diagram of transfer patterns of FIG. 2 after exposure. As FIG. 3 shows, glass panel 302 has a plurality of transfer patterns 304. Each transfer pattern 304 is exposed by the above-mentioned five masks in the same section of the glass panel 302. That is why every lens overlapping section 212, 214, 216, 218, 220 in FIG. 2 is in the same position of the photoresist layers I′, II′, III′, IV′, V′ and the photoresist patterns 202, 204, 206, 208, 210. And, each transfer pattern 304 on the glass panel 302 has an obvious lens mura 306.
As mentioned above, because of the precision bias after a long period of use, the lenses overlapping sections of the prior art exposure apparatus become the uniformity of the exposure light from each lens. So, in the prior art, after many mask exposures, the many PEP is complete, and the monitor has various critical dimensions (CD) and overlays in a few sections of the panel. The monitor has lens mura. The quality of the product drops, and the yield of manufacture decreases. Therefore, to solve the lens mura problem is an important issue.


A method for improving variable length decoding performance is provided. A variable length decoding module decodes a coded data to obtain a decoded data and a subsequent module receives the decoded data to perform further processing. A buffering module is coupled between the variable length decoding module and the subsequent module, and buffers the decoded data decoded by the variable length decoding module. A read part of the buffering module is cleared so that a content of an unused area of the buffering module is a predetermined value when the subsequent module reads the decoded data from the buffering module, wherein the unused area is a part of the buffering module except for the unread decoded data. The variable length decoding module does not write zero values of the decoded data into the buffering module when the variable length decoding module reads a zero output instruction among the coded data.

1. Field of the Invention
The invention relates to video or audio decoding, and more particularly to a variable length decoding (VLD).
2. Description of the Related Art
Variable length coding (VLC) is a multimedia file coding technique, which can reduce a great quantity of coded data, so that a data transmission bandwidth or a storing space will also be reduced. VLC is widely applied in various video or audio coding formats, such as motion picture experts group (MPEG) coding. Moreover, the coded data is decoded through VLD to be recovered as an original code when the coded data is playing.
FIG. 1A shows a block diagram of an MPEG coder 100. The MPEG coder 100 comprises a motion estimation module 102, a discrete cosine transformation (DCT) module 104, a quantization module 106 and a VLC module 108. First, the motion estimation module 102 compares an input image and a reference image to obtain an image difference. Next, the DCT module 104 transforms the image difference into a DCT value. After the DCT value is quantized by the quantization module 106, a VLC operation is performing by the VLC module 108 to obtain a coded data.
FIG. 1B shows a block diagram of an MPEG decoder 150. The MPEG decoder 150 comprises a VLD module 152, an inverse quantization module 154, an inverse discrete cosine transformation (IDCT) module 156 and a motion compensation module 158. First, the VLD module 152 decodes the coded data to a decoded data through a VLD operation, and then the decoded data is inverse-quantized to the DCT value by the inverse quantization module 154. Next, the IDCT module 156 transforms and recovers the DCT value to the image difference. Finally, the motion compensation module 158 compensates an image by the image difference to obtain an output image.
However, the VLD module 152 shown in FIG. 1B requires much time to output a serial of zero values as the decoded data during decoding. Statistically, the serial of zero values will account for 70%-98% of the decoded data output from the VLD module 152.
The serial of zero values are output at least during the following statuses: 1) when an end of block (EOB) data is read; 2) when a coded block pattern (CPB) bit is zero; 3) when a skipped macro block data is read; and 4) when a run-level pair of the coded data is decoded. FIG. 2A shows a data block 200 with an EOB code 202. The decoded data decoded by the VLD module 152 comprises 8×8 (64) data which are composed of a serial of data blocks.
In the data block 200 of the decoded data output from the VLD module 152, the data values (shown as label 204) appearing after a pixel 202 are zero, wherein a value of the pixel 202 is 5, when the VLD module 152 reads an EOB code from a received coded data, such as the pixel 202 shown in FIG. 2A, which is interpreted as 5, and then a 2 bit EOB code "10" is met. The EOB code is not shown in FIG. 2A due to the fact that an EOB code only exists in the coded data and can not be decoded.
Furthermore, each macro block is composed of six data blocks among the decoded data. The macro block comprises four Y data blocks and Cb and Cr data blocks sampled from the four Y data blocks, wherein the four Y data blocks are shown as label 212 in FIG. 2B. The coded data read by the VLD module 152 comprises a CBP bit for indication of the data blocks which values are zero within a macro block. Thus, the VLD module 152 will output a data block which has zero values when the VLD module 152 reads that a CBP bit of a data block 214 of the coded data is zero. In addition, the skipped macro block data represents that all values of six data blocks composing a macro block are zero, shown as six data blocks 223-228 of a macro block 222 in FIG. 2C. Therefore, total capacity of six data blocks are output as zero values when the CBP bit is read by the VLD module 152.
FIG. 2D shows a process wherein a data block 232 is coded as a serial of run-level pairs through a VLC technique. A run-level pair comprises a run value and a level value. For example, the data block 232 comprises a serial data "1005000008", wherein 8 is a last level value. The serial data is coded as 1, (2, 5) and (5, 8), wherein (2, 5) and (5, 8) are run-level pairs. Thus, the VLD module 152 will output a lot of zero values according to the run value of each run-level pair when the run-level pair of the coded data is decoded.
If continuous zero values are output, a decoding time will be delayed and total decoding performance of the MPEG decoder 150 will be reduced. Thus, by improving the above disadvantages VLD efficiency can be enhanced and performance of video and audio decoding can be substantially increased.

Variable length decoding device and method for improving variable length decoding performance