A method of flushing, disinfecting and lubricating a dental turbine handpiece by forcing a pressurized solution of a disinfectant and lubricant simultaneously through an air drive line to the handpiece when it is not in operation to flush dental debris through an exhaust line.

Dental instruments commonly include an air turbine driven by compressed air from a drive line. Such instruments include high and low speed turbine handpieces and scaling instruments, and all forms are referred to herein as turbine handpieces. The air drive line is routed within a flexible hose having an end fitting for removable attachment of the turbine handpiece. Also contained within the flexible hose are an exhaust line for returning the drive air after it has served its function in driving the turbine, a coolant line for removing excess heat from the dental work site, and in the case of high speed turbine handpieces a chip air line which mixes the compressed air with the coolant to generate a spray. During operation of dental turbine handpieces some debris from the mouth such as saliva, cuttings, coolant and pathogens, enters the turbine of the handpiece. The pressurized air that drives the turbine is not capable of flushing out this debris and indeed the debris may not even be fully flushed out during sterilization by autoclaving which normally is carried out on the handpiece after each use on a patient.
Dental turbine handpieces also require periodic lubrication. For this purpose the conventional practice is to remove the handpiece from the hose end fitting and connect it to an aerosol container of a lubricant which is typically of a petroleum base such as naphtha. A few bursts from the container serve to lubricate the moving parts of the turbine. The efficiency of the aerosol container decreases of course as its propellant is exhausted and it is by no means ideal that petroleum-based lubricant later enters the mouth of the patient, but those disadvantages have been tolerated.
It is the principal purpose of the present invention to provide a method by which the turbine of a dental handpiece may be disinfected after each use and flushed of all dental debris and simultaneously lubricated without necessitating the use of separate lubricant containers. This is to be achieved by forcing a pressurized solution of a disinfectant-lubricant through the air drive line to the turbine of the handpiece when it is not in operation on a patient, thus flushing dental debris through the exhaust line and effectively lubricating the moving parts of the turbine. Petroleum based lubricants are to be avoided.
My U.S. Pat. No. 4,668,190 describes apparatus for injecting a liquid solution into a dental water-injection system and certain of the components of that apparatus are useful in practicing the method of the present invention. I also describe in my U.S. Pat. No. 4,695,255 a method of lubricating human hard tissue during cutting by directing against that hard tissue a flow of solution which includes glycerin as a lubricating agent, and glycerin is the preferred lubricant in the practice of the present invention. Neither of these prior art references discloses any method of disinfecting and lubricating a dental turbine handpiece.
Elsewhere in the prior art it is known to deliver a liquid solution to a dental handpiece. For example U.S. Pat. No. 3,987,550 teaches the introduction of a prophylaxis material (a cleaning agent) through a slow speed handpiece and U.S. Pat. Nos. 3,949,753, 4,193,196 and 5,044,952 disclose other similar methods and apparatus. In each of them a solution is transmitted one way or the other through a dental instrument into the patient's mouth. None of those references, however, teaches the introduction of any solution through an air drive line of a dental turbine handpiece when it is not in operation, nor do they teach simultaneous disinfecting and lubricating of the turbine by the solution introduced through the air drive line.
U.S. Pat. No. 4,990,087 is also relevant because it discloses a method of lubricating, disinfecting and flushing a dental handpiece. However three distinct fluids are employed in that method. First a liquid lubricant from one bottle is passed through the air drive line to the turbine, then a liquid disinfectant from another bottle is passed through the coolant line but not the turbine air drive line and finally compressed air is injected for flushing. The method is deficient in that the disinfectant does not reach contaminating debris within the turbine or the chip air line. Moreover this method concludes with an air purging step which removes both excess disinfectant and lubricant. If autoclaving is carried out subsequently this is a disadvantage because a residue of disinfectant continues to function effectively during autoclaving. And a residue of lubricant is obviously desirable to be effective later during operation of the moving parts of the turbine.

Method of flushing, disinfecting and lubricating a dental turbine handpiece


The invention relates to a method and apparatus for controlling and for setting the switching states of switches which are connected to the electrical poles or outputs of a fuel cell and which are followed by a network, which is fed from the fuel cell, and has loads. The invention is preferably suitable for use in a vehicle. The switches are opened if the fuel cell and/or the vehicle assume critical states.

This application claims the priority of German patent document 199 50 008.8, filed Oct. 18, 1999 and PCT International Application No. PCT/EP00/09980, filed Oct. 11, 2000, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a method and apparatus for controlling and for setting the switching state of a switching connection between the electrical outputs or poles of a fuel cell and an electrically isolated network which is arranged in the apparatus, and which supplies power from the fuel cell to loads that connect therewith. A further network is provided in the apparatus, whose voltage is lower than that of the network which can be connected to the fuel cell and that of electrical loads as well as that of a storage battery.
Mobile power generating systems (with fuel cells, in particular) often have two electrical networks. The network which is fed from the fuel cell is not grounded, is electrically isolated, and contains, for example, one or more drive motors for the mobile apparatus. A range of auxiliary units are required for starting and operation of the fuel cell, and their drive motors are supplied with power from a rechargeable battery while the fuel cell is being started. The rechargeable battery is arranged in a low-voltage network, and supplies the drive motors of the auxiliary units (which are arranged in a high-voltage network) with electrical power via a DC/DC converter. During operation of the fuel cell, the battery can be charged via the converter arranged between the two networks. The converter, which provides DC isolation between the two networks, feeds the loads which are connected to the low-voltage network, even during operation of the fuel cell. At least in vehicles, one pole of the low-voltage network is generally connected to the vehicle ground.
In order to avoid any danger to personnel or to parts of the mobile device resulting from current from the fuel cell, the switching connection at the output of the fuel cell either must not be closed, or must at least be opened in certain situations or when certain events occur. For example, in the case of fuel cells which are operated with hydrogen, the fuel cell system must be checked for uncontrolled escape of hydrogen before and during operation. In order to prevent a defect in the fuel cell, it is necessary to ensure that the high-voltage network is not connected to the fuel cell until it has reached operational readiness, and is quickly disconnected from it if an unacceptably large amount of current is drawn, for example in the event of a short circuit, or if the output voltage is too low. A minimum isolation resistance between the two networks must also always be maintained, for safety reasons.
The invention is therefore directed to a method and apparatus for use in a power supply system, which has a fuel cell with a switching connection for an electrically isolated network containing electrical loads and has a further network designed for a lower voltage than the fuel cell voltage, with further electrical loads. According to the invention, the switching connection between the outputs of the fuel cells and the network can either not be closed, or can be opened quickly in certain situations or certain operating states in which a conductive connection between the electrical outputs of the fuel cell and the electrically isolated network can endanger personnel, or endanger parts of the apparatus or the fuel cell itself.
This and other objects and advantages are achieved by the method and apparatus according to the invention, in which sensors arranged in or on the apparatus are used to detect and signal the existence of certain "apparatus states" in which the supply of power to the electrically isolated network must be precluded or stopped for safety reasons. The sensors are monitored by a control and evaluation unit that is supplied with power from the network. The switching connection has at least one switching or operating contact of a switching member connected to each output or pole of the fuel cell, in order to disconnect the electrically isolated network from the outputs or poles of the fuel cell that are electrically isolated from the conductive parts of the apparatus. The switching or operating contacts which are connected to the poles or outputs are part of one switching member (or of separate switching members connected to the switching and control unit). The energy for closing the switching or operating contacts during starting of the fuel cell is released to the switching member or members by the switching and control unit once the fuel cell has reached operational readiness, provided the switching and control unit does not detect any sensor signal indicating that closure of the switching or operating contacts is not permissible for safety reasons. Upon detection of a sensor signal indicating that closure of the switching or operating contacts is not permissible for safety reasons, the control and evaluation unit blocks or interrupts the power supply to the switching member or members.
The method according to the invention achieves a high degree of operational reliability for the fuel cell system. It is thus possible to prevent danger to personnel and to the environment as well as to parts of the apparatus itself. In the event of short circuits in the electrically isolated network, or in the loads fed from this network, the power supply to the switching member members fails, so that the switching or operating contacts open automatically. When a danger or defect is signalled, the fuel cell system changes to a state in which the output power from the fuel cell is interrupted, that is to say a safe operating state is reached.
The series circuit formed by a resistor and a switching or operating contact of a further switching member (which is connected to the switching and control unit and can be operated separately from the other switching members) is preferably connected in parallel with one of the switching or operating contacts which are connected to the outputs or poles of the fuel cell. Energy for closing the switching or operating contact of the further switching member is supplied at the same time as the energy for closing the switching or operating contact of the switching member after the starting of the fuel cell and after it has reached operational readiness. If the switching and control unit detects a signal which indicates that closure of the switching or operating contacts of the switching members is not permissible, power for operating the further switching member and the other switching members is blocked or interrupted. The method described above results in an initial charge between the fuel cell outputs and the electrically isolated network. The potentials on both sides of the switching member contacts are matched by closing the initial charging path, which contains the resistor, in order to largely avoid generating sparks when the contacts are closed.
In one preferred embodiment, the emergence of hydrogen from the hydrogen-producing or hydrogen-storing units is monitored by means of gas sensors. A sensor which is connected downstream from the fuel cell monitors whether the load current from the fuel cell has overshot or undershot limit values, and at least one crash sensor monitors whether the mobile apparatus has impacted with an obstruction. The isolation resistance of the electrically isolated network from the mobile apparatus earth is monitored. In addition, the output voltage of the fuel cell is monitored to determine whether limit values are overshot or undershot. Furthermore, the closure state of doors and covers is monitored by switches, and the supply voltage of the further network is monitored for limit values being overshot and undershot. Finally, the presence of conditions for the opening of the switching or operating contacts of the switching members is checked.
In particular, the isolation resistance between the electrically isolated network and the mobile apparatus ground is determined by means of a pulse measurement method, with alternate positive and negative pulses being passed to ground via a measurement resistor of predetermined magnitude. The pulses cause a current to flow via the isolation resistances to a reference point in the network; and the latter current is measured by means of the voltage drop across the measurement resistor. The measurement voltage is supplied to an A/D converter via a high-pass filter and a low-pass filter. The isolation resistance is monitored to detect any overshooting of a lower threshold (which can be predetermined) or of an excessively high threshold. The isolation measurement is carried out continuously during operation of the mobile device while, during starting, it is carried out as a quick measurement with reduced accuracy. If the isolation resistance is too low, the ungrounded network is disconnected from the fuel cell.
In another expedient embodiment, the current measurement device is monitored by feeding a test current into an additional winding of the current sensor, which contains a current transformer.
For safety reasons, in one preferred embodiment, when one or more of the gas sensors responds, the contacts of the switching connection between the outputs or poles of the fuel cell and the electrically isolated network, as well as at least one contact of an additional switching member in the further network are opened in order to interrupt the power supply at least to the switching and control unit.
In the apparatus according to the invention, the outputs or poles of the fuel cell are each connected via at least one switching or operating contact to the electrically isolated network. A control and evaluation unit of an assembly has a processor which is connected to an internal bus of the mobile apparatus, a logic circuit with logic functions in the form of hardware, an A/D converter (which is connected to the processor in a DC-isolating manner and which is connected at its input to analog sensors for the current and voltage of the fuel cell and to a measurement device for the isolation resistance between the electrically isolated network and the mobile apparatus earth), a sensor for fuel cell current which is connected to the processor and the logic circuit in a DC-isolated manner, and a power supply unit, which is fed from the further network, with DC isolation for supplying an operating voltage to the A/D convertor. Control modules are connected to the output of the logic circuit and converters that are connected to the processor and to the logic circuit, for supplying an operating voltage to the hydrogen sensors, and for matching signals which are emitted from these sensors to the levels of the logic circuit and of the processor.
The logic module, the processor, the converters and the control modules are supplied with an operating voltage from the further network. At least one output of the processor (30) is connected to a corresponding input of the logic circuit, which logic circuit is connected to sensors for producing signals relating to operating states of the mobile apparatus or its modules. The enabling of output signals from the control modules can be controlled by means of (or via) the logic circuit, which is controlled by a higher-level appliance and is connected to the respective one coil of a first switching member which has one of the two contacts and of a second switching member which has the other switching contact. For current, voltage and/or isolation resistance measured values which are detected by the processor, and for sensor measured values which are detected by the logic circuit for which the supply to the electrically isolated network must be precluded or stopped for safety reasons, the output of output signals from the control modules to the coils is blocked or interrupted.
The assembly according to the invention provides a compact controller of relatively low weight and with small dimensions for a mobile fuel cell system, by means of which numerous safety requirements can be satisfied during operation of the fuel cell system. The signals which are processed by the logic circuit relating to critical states of the fuel cell system or of the mobile device cause the switching contacts to be opened immediately.
A further switching or operating contact of a third switching member in series with a resistor is preferably arranged in parallel with the contact of the second or first switching member, and the third switching member is connected to a driver module that is supplied with an operating voltage from the further network on the assembly. The driver module is connected to the logic circuit such that, in the start phase after the fuel cell has reached operational readiness (before the emission of a control signal to the one control module, which operates the second or first switching member), the logic circuit applies a control signal to the driver module to emit an operating signal to the third switching member at the same time as the emission of a control signal for operating the first or second switching member. It also blocks the emission of control signals to operate the three switching members, in order to disconnect the outputs of the fuel cell from the electrically isolated network. The method described above results in an initial charge between the fuel cell outputs and the electrically isolated network. The initial charge causes the potentials on both sides of the contact poles to be matched to one another, thus largely avoiding the generation of sparks during switching. This protects the contacts.
When the gas sensors respond, it is also advantageous to disconnect not only the switching connection between the fuel cell and the electrically isolated network, but also the connection for the further network to the rechargeable battery. For this purpose, a further driver module, which receives the operating voltage from the further network on the assembly is connected to the output of the logic circuit, and a system relay is operated, which can be disconnected together with the switching members when at least one gas sensors responds, in order to interrupt the power supply from the further network at least for that assembly.
In one preferred embodiment, the assembly has a printed circuit board with a first section fitted with those components that are supplied with an operating voltage from the further network (such as the logic circuit, the processor, the converter and control and driver modules with associated conductor tracks) and the connections for the coils of the switching members and the connections for sensors that are supplied with the voltage of the further network, for bus conductors and for the earth connection. This first section is separated from a further section of the printed circuit board, which is fitted with those components to which the voltage of the fuel cell or the isolated electrical network is applied (such as the current sensor, a voltage divider for measuring the voltage and the associated conductor tracks as well as connections for the network fed by the fuel cell). The separation (which is formed by the two sections) of those components and conductor tracks which carry low voltages from those components and conductor tracks which carry high voltages results in a high level of safety with regard to short circuits between the two networks on the printed circuit board.
In one expedient embodiment, the negative side of the fuel cell voltage provides the reference potential for those components on the assembly to which the voltage of the fuel cell is applied; it is connected to one connection of the second section of the assembly. This reference potential allows major circuit simplification. The current sensor preferably has a current transformer with a conductor that passes through the printed circuit board and through a current transformer core arranged on the printed circuit board (without touching them). The current is measured using the compensation principle.
In particular, the current transformer is fitted with an additional winding, which is connected to a device for feeding in a defined current and is used to monitor the current measurement for functionality. Upper and lower limit values for the fuel cell current are stored in the processor. An appropriate signal is emitted to the bus, and the switching or operating contacts downstream from the poles or outputs of the fuel cell are opened if the upper limit value is exceeded, or if the lower limit is undershot.
A measurement resistor is preferably in the second section of the printed circuit board for measuring the isolation resistance of the isolated electrical network from the ground of the mobile device. Positive and negative voltage pulses applied to the measurement resistor cause a current flow, which in turn causes a voltage across the measurement resistor. The latter voltage is supplied via a high-pass filter and a low-pass filter to the A/D converter, whose output signals are supplied to the processor. The high-pass filter blocks the fuel cell DC voltage, and the low-pass filter screens out radio-frequency interference. After a specific waiting time, the processor processes the measured values for determining the isolation resistance, in order to avoid transferring any measured values during transient oscillation processes.
The processor, together with its software, is preferably monitored by a watchdog module. Thus, a processor module defect or a software crash causes the contacts at the output of the fuel cell to open, so that the initial charging path is also disconnected.
Expediently, the bus is also checked continuously for correct operation. It is advantageous for the supply voltage for the further network to be detected by means of an A/D converter, for example by means of an appropriate input to the processor, and to be monitored against predetermined limit values. If these limit values are overshot or undershot, the signal for opening the make or switching contacts is passed from the processor to the logic circuit.
In one particularly expedient embodiment, the inputs and outputs of the components arranged on the printed circuit board (such as the logic circuit, processor, control and driver stages and converter) are designed to be resistant to short circuits, resulting in a high level of operational safety.
In particular earth shorts and short circuits are detected as faults.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Method and arrangement for controlling a switching connection between the electrical outputs of a fuel cell and an isolated electrical network


A ventilation-mast monitoring system for filling stations contains a thermal through-flow measuring device (30) and a hydrocarbon-measuring device (30). The thermal through-flow-measuring device (30) has a heating device and a temperature sensor which is located in the flow path and reacts to the temperature of the heating device, and is configured to sense the gas volume flow escaping from a reservoir tank (1) via a ventilation mast (4) of the reservoir tank (1) of a filling station or entering the reservoir tank (1). The hydrocarbon-measuring device (30) is configured to sense the direction of the gas volume flow escaping from or entering the reservoir tank (1) via the ventilation mast (4). A control device which is configured to receive and to process measuring signals emitted by measuring devices of the system is preferably provided as a further system component.

The invention relates to a ventilation-mast monitoring system for filling stations.
At filling stations, the fuels which are intended for refuelling motor vehicles are generally stored in reservoir tanks which are buried in the ground. Such a reservoir tank is connected to a ventilation mast which projects out of the ground and by means of which, depending on the pressure conditions prevailing in the reservoir tank, gas (in particular a fuel/air mixture) can escape from the reservoir tank or air can enter the reservoir tank. The pressure in the reservoir tank can vary, for example if the fuel cools to the temperature of the ground after the reservoir tank has been filled. Also, pressure fluctuations occur in the reservoir tank if, when refuelling a motor vehicle, the fuel feed rate does not correspond to the gas feed rate of the gas recirculation system. The cause of this may be, for example, faults in the gas recirculation system or refuelling processes in motor vehicles in which fuel vapours are retained with on-board means (ORVR). Since the pressure in a reservoir tank can increase and decrease, and as little fuel gas or vapour as possible should be allowed to escape into the environment, ventilation masts are frequently provided in their upper end region with a throttle or a gas pendulum valve. A throttle has a high flow resistance and therefore reduces the gas volume flow through the ventilation mast while a gas pendulum valve acts as an overpressure valve in both directions so that gas can flow through the ventilation mast only if an overpressure in the reservoir tank exceeds a predefined value or an underpressure drops below a predefined value.
A ventilation-mast monitoring system can be used to acquire an overview of the pressure conditions in a reservoir tank of a filling station and, if appropriate, to adjust the pressure. Such a system is described in EP 0 985 634 B1. In said system, the ventilation mast is provided with a gas pendulum valve, a non-return valve, a through-flow meter and a mass spectrometer serving as a hydrocarbon sensor. The measured data is processed in a controller and makes it possible, in particular, to recognize an ORVR vehicle when refuelling and to set the gas recirculation accordingly.
The through-flow meter of the previously known ventilation-mast monitoring system is a conventional device which is limited in its measurement dynamics and, for example, can no longer sense quantitatively if a large quantity of gas escapes through the ventilation mast while the reservoir tank is being filled, because the gas pendulum hose, which serves to recirculate the gas expelled out of the reservoir tank during refuelling into the tanker vehicle, has inadvertently not been connected.

Ventilation mast monitoring system for filling stations


A document reading device of the present invention includes a glass platen on which a document is to be laid and document reading means including scanning optics for reading the image of the document laid on the glass platen. A document pressing member presses the document against the surface of the document table. The document pressing member is removably mounted to the body of the document reading device by hook and loop fasteners.

1. Field of the Invention
The present invention relates to a copier, facsimile apparatus, printer, plotter, stencil printer or similar printer, multifunction machine or similar image forming apparatus and more particularly to a document reading device mounted on such an image forming apparatus, a document reading device including a scanner or similar image reading unit and a cover plate mounted on the document reading device.
2. Description of the Background Art
It is a common practice with a document reading device mounted on an image forming apparatus or an image reading device including a scanner or similar image reading unit to include a cover plate configured to press a document against a glass platen or similar document table or to provide an ADF (Automatic Document Feeder) with such a cover plate. This kind of document reading device is taught in, e.g., Japanese patent laid-open publication Nos. 8-195852, 8-234330, 9-244161 and 6-222479 and Japanese Patent No. 2652021.
Japanese patent laid-open publication No. 8-195852, for example, teaches a cover plate configured separately from an ADF structural body which is heavy.
A scanner or similar image reading device or a document reading device has customarily been required to selectively use light or white background or dark or black background when processing an input image. However, it is necessary for a user needing black background to prepare a black background member beforehand and substitute it for a white or usual background member, limiting serviceability or operability available with the document reading device.

Document reading device and image forming apparatus using the same


An obstacle sensor includes a line light irradiating unit including a light-emitting unit, a light-emitting driving unit to drive the light-emitting unit, and a first conical mirror, an apex of which is disposed towards the light-emitting unit in a light irradiation direction of the light-emitting unit and which converts light emitted from the light-emitting unit into line light irradiated in all directions, and a reflected light receiving unit including a second conical mirror to condense light, that is irradiated from the first conical mirror and is then reflected from an obstacle, a lens, that is spaced from the apex of the second conical mirror by a predetermined distance and transmits the reflected light, an imaging unit to image the reflected light that passes through the lens, an image processing unit, and an obstacle sensing control unit.

1. Field
Embodiments of the present disclosure relate to an obstacle sensor capable of sensing obstacles in all directions and a robot cleaner including the same.
2. Description of the Related Art
In general, an obstacle sensor irradiates light, ultrasonic waves and the like, senses light or ultrasonic waves reflected from obstacles, judges presence of obstacles and the distance thereof based on time difference, phase difference and intensity difference of the sensed signals or judges the distance using a reflected angle.
Recently, a method for measuring the distance between a sensor and an obstacle using point light source or structural light such as line light has been developed. However, use of a point light source causes a problem in that only an obstacle present in the direction of a beam radiated from the point light source is detected. When a point light source sensor is rotated in order to solve this problem, a separate servomechanism and some degree of scanning time are required, thus disadvantageously causing deterioration in efficiency.
In a case of using a line light, obstacles present throughout a plurality of regions, not in one point, can be simultaneously detected, but there are problems such as limited detection range and difficulty of formation of uniform line light when a line light is formed using a cylindrical lens of the related art.

Obstacle sensor and robot cleaner having the same


A garage door operator has a light which is turned on for a preset period by the controller each time the operator motor is operated. A pedestrian door is equipped with a magnetic switch which signals the controller when the door is opened, causing the light to be turned on for the preset period. A switch console has a vacation switch, a work light switch and a push button which, with the magnetic switch, send signals to the controller. Voltage level encoding and decoding is used to minimize the number of connecting wires between the console and the controller. The controller comprises a microprocessor subject to the switch inputs and programmed to produce output signals for operator motor control and light control.

Garage door operators responsive to manually controlled switches directly wired to the controller or coupled by radio signals to the controller are well known. The controller normally opens a door if it is closed when the switch is actuated and closes the door if it is open when the switch is actuated. Usually such operators are equipped with a lamp which illuminates the garage each time the operator is actuated and a time delay keeps the lamp on for a few minutes after actuation. It is also known to provide a work light switch to turn on the lamp and to turn it off when desired. A switch console on the garage wall houses the work light switch and the push button for door actuation. In some cases a vacation switch is included in the console for disabling all operator functions as long as the switch is closed; this is typically used to prevent door operation when the user is away for an extended period.
While such garage door operators are able to illuminate the garage upon manual switch operation, a person entering a dark garage through the pedestrian door from the house or from outside will have to locate and operate the work light switch to obtain light and again operate the switch when leaving the garage to turn out the light. It is thus desirable to have a light turn on when the pedestrian door is opened and to later turn off without user action. Thus it is proposed here that a desirable additional function of a garage door operator is to illuminate the lamp whenever the pedestrian door is opened to allow immediate vision by a user upon entering an otherwise dark garage and to automatically turn off the lamp.

Garage door operator with pedestrian light control


A variable displacement swash plate compressor includes a housing, drive shaft, first and second radial bearings, swash plate, and actuator. The actuator includes a movable body and fixed body. The movable body includes a main portion and circumferential wall. The main portion includes an insertion hole. The housing includes an accommodation wall. A first clearance exists between the circumferential wall and fixed body. A second clearance exists between the drive shaft and wall of the insertion hole. A third clearance exists between the circumferential wall and accommodation wall. A fourth clearance exists between the drive shaft and first radial bearing. A fifth clearance exists between the drive shaft and second radial bearing. The first and second clearances differ in size. The sum of the third clearance and the smaller one of the first and second clearances is larger than the fourth and fifth clearances.

The present invention relates to a variable displacement swash plate compressor.
Japanese Laid-Open Patent Publication No. 5-172052 discloses a variable displacement swash plate compressor (hereinafter referred to as compressor). The compressor includes a housing formed by a front housing segment, a cylinder block, and a rear housing segment. The front housing segment includes a first suction chamber and a first discharge chamber. The rear housing segment includes a second suction chamber and a second discharge chamber. The rear housing includes a pressure adjustment chamber.
The cylinder block includes a swash plate chamber and cylinder bores. Each cylinder bore includes a first cylinder bore, which is formed in the front side of the cylinder block, and a second cylinder bore, which is formed in the rear side of the cylinder block. A radial bearing is arranged near the first cylinder bores of the cylinder block. A control pressure chamber, which is connected to the pressure adjustment chamber, is formed near the second cylinder bores of the cylinder block.
A drive shaft, which extends through the housing, is rotatably supported by radial bearings in the cylinder block. A swash plate, which is rotated by the drive shaft, is arranged in the swash plate chamber. A link mechanism is located between the drive shaft and the swash plate to change the inclination angle of the swash plate. The inclination angle refers to the angle of the swash plate relative to a direction that is orthogonal to the rotation axis of the drive shaft. Each cylinder bore receives a piston, which is reciprocated in the cylinder bore to form a compression chamber. When the swash plate rotates, a conversion mechanism reciprocates the piston in each cylinder bore with a stroke that is in accordance with the inclination angle. An actuator changes the inclination angle of the actuator, and a control mechanism controls the actuator.
The actuator, which is arranged in the control pressure chamber, is not allowed to rotate integrally with the drive shaft. More specifically, the actuator includes a non-rotation movable body that covers a rear end of the drive shaft. An inner surface of the non-rotation movable body supports the rear end of the drive shaft so that the drive shaft is rotatable relative to the non-rotation movable body and movable in the axial direction. An outer surface of the non-rotation movable body is movable in the axial direction in the control pressure chamber but not about the rotation axis. A pushing spring is arranged in the control pressure chamber to urge the non-rotation movable body toward the front. The actuator includes a movable body that is coupled to the swash plate and movable in the axial direction. A thrust bearing is arranged between the non-rotation movable body and the movable body. A pressure control valve is arranged between the pressure adjustment chamber and the discharge chamber to change the pressure in the control pressure chamber and move the non-rotation movable body and the movable body in the axial direction.
The link mechanism includes a movable body and a lug arm, which is fixed to the drive shaft. The rear end of the lug arm includes an elongated hole that extends toward the rotation axis from the outer side in a direction orthogonal to the rotation axis. A pin is inserted into the elongated hole to support the front side of the swash plate so that the front side is tiltable about a first tilt axis. The front end of the movable body includes an elongated hole that extends toward the rotation axis from the outer side in a direction orthogonal to the rotation axis. A pin is inserted into the elongated hole to support the rear side of the swash plate so that the rear side is tiltable about a second tilt axis, which is parallel to the first tilt axis.
In the compressor, the pressure adjustment valve is controlled to open and connect the discharge chamber and the pressure adjustment chamber so that the pressure of the control pressure chamber becomes higher than the pressure of the swash plate chamber. This moves the non-rotation movable body and the movable body forward. As a result, the inclination angle of the swash plate increases, and the stroke of the pistons increases. The compressor displacement of the compressor for each drive shaft rotation also increases. When the pressure adjustment valve is controlled to close and disconnect the discharge chamber and the pressure adjustment chamber, the pressure of the control pressure chamber decreases to the same level as the pressure in the swash plate chamber. This moves the non-rotation movable body and the movable body rearward. As a result, the inclination angle of the swash plate decreases, and the stroke of the pistons decreases. The compressor displacement of the compressor for each drive shaft rotation also decreases.
In a compressor like the one described above, compression reaction force, discharge reaction force, and the like that act on the pistons produce a radial load that acts on the drive shaft. Thus, even though the radial bearings are arranged between the housing and the drive shaft, displacement of the drive shaft in the radial direction is unavoidable. This tendency is especially outstanding in the compressor described above because there is no radial bearing in the proximity of the first cylinder bores. In such a compressor, when the actuator moves, the non-rotation movable body moves in the axial direction relative to the drive shaft inside the control pressure chamber.
In the above compressor, an O-ring is arranged between the outer surface of the non-rotation movable body and the inner surface of the control pressure chamber. When the actuator moves in the compressor, the radial load produced by the drive shaft may deform the O-load beyond a tolerable margin. In this case, the outer surface of the non-rotation movable body may interfere with the inner surface of the control pressure chamber, and a friction force proportional to the radial load would act between the outer surface of the non-rotation movable body and the inner surface of the control pressure chamber. This would hinder forward and rearward movement of the non-rotation movable body and the movable body in the compressor. Thus, the controllability would be low when varying the compressor displacement.
In particular, when increasing the inclination angle of the swash plate to increase the compressor displacement, the radial load acting on the drive shaft increases. This increases the friction force. Thus, the time used to increase the compressor displacement would become longer. This would affect the response of the compressor and cause a cooling delay. In order to avoid such a situation, the control pressure chamber would have to be enlarged in the radial direction so that the non-rotation movable body and the movable body overcome the friction force when moving forward. However, this would enlarge the housing and consequently the compressor. Thus, limitations may be imposed on the arrangement of the compressor when installing the compressor in a vehicle or the like.
When enlarging the control pressure chamber in the radial direction to increase the compressor displacement, the volume of the control pressure chamber increases, and a longer time would be used to decrease the pressure of the control pressure chamber. In this case, the compressor displacement cannot be readily decreased when the vehicle is accelerated. Further, if there is a delay in the decrease of the compression when the engine speed is low and the compressor displacement remains high, the control executed by an ECU may stall the engine. If the engine were to be controlled in accordance with such slow changes in the compressor displacement, the control executed by the ECU would be complicated.

Variable displacement swash plate compressor


The present invention relates to a system for replication and encapsidation of recombinant DNA fragments into virus particles comprised of adenovirus associated viral (AAV) capsid proteins. The invention provides a means of obtaining recombinant viral stocks that may be used to treat patients suffering from genetic diseases.

At the present time, treatments for most genetic diseases do little to alleviate the symptoms associated with the genetic disease and considerable effort is currently underway to develop new, safe and effective methods of treatment. Recent progress in the areas of molecular biology and genetic engineering have lead to the isolation and characterization of genes associated with genetic diseases. This in turn has lead to the development of the concept of gene therapy i.e., the replacement or supplement of defective genetic information with normal functional genes, and its potential use for treatment of genetic disorders.
The most well studied models for gene therapy involve gene transfer using recombinant pathogenic viruses to express new genetic information in order to correct disease phenotypes. Until recently, the most widely researched viral vectors for use in gene therapy were the retroviruses (Miller, A. D., 1990, Human Gene Ther. 1:5-14). One problem associated with retroviral use is the random integration of retroviruses into the host genome which can lead to insertional mutagenesis. In addition, the long terminal repeats (LTR) structures located at the ends of the retroviral genome contain promoter/enhancer activity that may lead to activation of genetic loci located adjacent to the integrated viral DNA. For example, integration of retroviral DNA adjacent to a proto-oncogene may lead to inadvertent activation of proto-oncogene expression which may, in turn, lead to transformation and tumorigenesis. This is illustrated, for example, by recent evidence indicating that retrovirus vectors in non-human primates results in T cell lymphomas. More recent efforts in the field of gene therapy have focussed on the development of viral vectors lacking the deleterious characteristics of the retroviruses.
In addition to the retroviruses, the adeno associated viruses have also been studied as an alternative system for delivery of stable genetic information into the cell. The AAV genome is composed of a linear single stranded DNA molecule of 4680 nucleotides which contains major open reading frames coding for the Rep (replication) and cap (capsid) proteins. Flanking the AAV coding regions are the two 145 nucleotide inverted terminal (ITR) repeat sequences that contain palindromic sequences that can fold over to form hairpin structures which function as primers during initiation of DNA replication (FIG. 1). In addition, the ITR sequences are needed in cis, for viral integration, rescue from the host genome and encapsidation of viral genomic DNA, into mature virions (Muzyczka, N. 1992, Current Topics in Microbiology & Immunology. 158, 97-129).
AAV can assume one of two pathways upon infection into the host cell. In the presence of helper virus, AAV will enter the lytic cycle whereby the viral genome is transcribed, replicated, and encapsidated into newly formed viral particles. In the absence of helper virus function, the AAV genome integrates as a provirus into of the host cell genome through recombination between the AAV termini and host cell sequences (Cheung, A. et al., 1980, J. Virol. 33:739-748; Berns, K. I. et al., 1982, in Virus Persistence, eds. Mahey, B. W. J., et al. (Cambridge Univ. Press, Cambridge), pp. 249-265).
Characterization of the proviral integration site and analysis of flanking cellular sequences indicates that AAV viral DNA integrates specifically into the long arm of human chromosome 19 (Kotin, R. M. et al., 1990, Proc. Natl. Acad. Sci. USA 87:2211-2215; Samulski, R. J. et al., 1991, EMBO J. 10:3941-3950). This particular feature of AAV reduces the likelihood of insertional mutagenesis resulting from random integration of viral vector DNA into the coding region of a host gene. Furthermore, in contrast to the retroviral LTR sequences, the AAV ITR (inverted terminal repeat) sequences appear to be devoid of transcriptional regulatory elements, reducing the risk of insertional activation of proto oncogenes.
Recent work with AAV has been facilitated by the discovery that AAV sequences cloned into prokaryotic vectors are infectious (Samulski, et al. 1982, Proc. Natl. Acad. Sci. U.S.A. 79:2077-2081). For example, when a plasmid containing an intact AAV genome is transfected into cells in the presence of helper virus, AAV can be rescued out from the plasmid vector and enter the lytic pathway leading to production of mature virions. In the absence of helper virus the recombinant AAV vector will integrate into the host cell genome and remain as a provirus until the cell subsequently becomes infected with a helper virus.
One problem associated with the use of vectors containing an intact AAV genome is the size limitations imposed on the vectors by the packaging of DNA fragments into mature viral particles. Prior to the present invention it was unknown what viral sequences were required for replication, and encapsidation of the DNA into viral particles, or alternatively, for integration of vector DNA into the host genome. The present invention defines a novel 165 bp sequences derived from AAV that can function to direct the replication and encapsidation of DNA into viral particles and/or the integration of vector DNA into the targeted host genome.


A method and computer program for clustering a string are described. The string includes a plurality of characters. R unique n-grams T1 . . . R are identified in the string. For every unique n-gram TS, if the frequency of TS in a set of n-gram statistics is not greater than a first threshold, the string is associated with a cluster associated with TS. Otherwise, for every other n-gram TV in the string T1 . . . R, except S, if the frequency of n-gram TV is greater than the first threshold, and if the frequency of n-gram pair TS-TV is not greater than a second threshold, the string is associated with a cluster associated with the n-gram pair TS-TV. Otherwise, for every other n-gram TX in the string T1 . . . R, except S and V, the string is associated with a cluster associated with the n-gram triple TS-TV-TX. Otherwise, nothing is done.

A growing application for relational database systems is a data warehouse which stores a vast quantity of data concerning, for example, a company's ongoing operations. Many data warehouse implementations integrate information from a number of sources. Because more than one data source is involved, the system may receive inconsistent and/or incorrect data. Existing systems execute a transformation process to correct the errors or make the data consistent. Part of this transformation process includes identifying and eliminating duplicate records and linking records into common groups. For example, a system may group records associated with a particular household. Typically, similar records are identified based on fuzzy matching to address issues such as data entry errors or phonetic errors.
Clustering is a common technique used to partition a data set to reduce the complexity cost of comparing data set records and/or to support partitioned execution. One known clustering technique, known as probabilistic clustering, is based on the concept of evaluating multiple iterations of exact matching on fields in the input records. Results from the multiple runs are combined to identify duplicates or groups. Examples of this technique include the sorted moving window algorithm. Another clustering technique, known as the feature vector approach, is based on mapping the input string to an N dimensional vector. The vector represents the frequency of each word token in the string. Similarity is then defined as the proximity of feature vectors in feature space. A common similarity measure is the cosines measure. The feature vector approach has typically been applied to the problem of clustering documents which include many tokens.
An example fuzzy matching algorithm provides a mechanism to efficiently cluster strings into partitions of potentially similar strings. The records within each partition can then be compared using a more exhaustive similarity measure. Examples of similarity measures include:                A. Pattern similarity—n-grams (i.e., substrings of length n within the string), are the most common measure. n-gram similarity is based on the concept that strings with common n-grams can be considered similar.        B. Data entry similarity—Edit distance is the most common measure. Edit distance counts the insertions, deletions, substitutions and transpositions needed to transform one string into another.        C. Phonetic similarity—Strings are compared to determine their phonetic (speech sound) similarity.


A data access method uses variable mask data and shift amount to write data into or read data from a data storage zone. The mask data and shift amount are determined according to starting and end data bit addresses in a bit range of the data to be read or written. Therefore, the data access method is applicable to various platforms with various byte endians.

In a digital data processing system such as a computer system or a network communication system, some specific digital data such as common parameters, control data or addresses are generally stored together in a designated data storage zone to be referred when required and to save storage space of the memory. The data format of the designated data storage zone can be an array for successively storing a plurality of data bytes.
Please refer to FIG. 1 which schematically shows the data storage zone 10 and three data bytes B11, B12 and B13 stored in the data storage zone 10. Each of the data bytes B11, B12 and B13 includes 8 bits, and thus there are 24 bits (numbers 0–23) stored in corresponding addresses (0)˜(23) in the data storage zone 10.
In practical, the 24 bits are divided into 5 columns 101˜105 for respectively storing 5 sets of different bit data. For example, there are four bits 0˜3 in the first column 101, six bits 4˜9 in the second column 102, seven bits 10˜16 in the third column 103, two bits 17˜18 in the fourth column 104, and five bits 19˜23 in the fifth column 105.
Since the digital processing system stores data byte by byte, the 5 sets of bit data in columns 101˜105 should be properly shifted and operated to be successfully accessed. For example,                Bit data in column 101=data byte B11 & 0x0F;        Bit data in column 102=((data byte B12 & 0x03)<<4)|((data byte B11 & 0xF0)>>4);        Bit data in column 103=((data byte B13 & 0x01)<<6)|((data byte B12 & 0xFC)>>2);        Bit data in column 104=(data byte B13 & 0x06)>>1; and        Bit data in column 105=(data byte B13 & 0xF8) 3;wherein each of the expressions "0x0F", "0x03","0xF0","0x01","0xFC", "0x06" and "0xF8" indicates an 8-bit hexadecimal mask data, the expression "X & Y" indicates an AND gate logic operation of X with Y, the expression "X|Y" indicates an OR gate logic operation of X with Y, the expression "X>>Y" indicates the rightward shift of the data X by Y bits and the expression "X<<Y" indicates the leftward shift of the data X by Y bits.
In the above processing method, the mask data and shift amounts are preset and constant. When the bit specifications in the columns are rearranged, the mask data and shift amounts will be unable to be adjusted accordingly. Therefore, the bit data cannot be accessed correctly. Conventionally, these data have to be adjusted manually at the time the specification changes.
In order to solve this problem, the processing method is operated with bits as basic units in another prior art. Giving the five columns 101˜105 mentioned above as an example, the five columns 101˜105 are adjacent to one another, and respective bit numbers required by the five columns 101˜105 are determined. Afterwards, when the data in the columns are being accessed, the mask data and shift amounts are not required any longer. In stead, the bit ranges of the columns should be defined in advance, and then the columns are independently accessed. For example, the data storage zone 10 has a format of structural array, and the bit numbers of the sequentially adjacent columns 101˜105 are defined as follows:                Bit data in column 101 includes 4 bits;        Bit data in column 102 includes 6 bits;        Bit data in column 103 includes 7 bits;        Bit data in column 104 includes 2 bits; and        Bit data in column 105 includes 5 bits.
This method, however, is performed logically. In practice, the digital processing system does not provide any real and continuous memory block for the bit data to be stored as immediately adjacent columns. The data, in stead, have to be stored according to the basic storage format of the system. For example, as shown in FIG. 2A, the basic storage format of the system is two bytes (16 bits) stored in corresponding addresses (0)˜(15) in the data storage zone 10. As described above, the bit data in columns 101, 102 and 103 are 4, 6, and 7 bits, respectively. Therefore, the storage of the bit data in the third column 103 is beyond the basic storage capacity, i.e. 16 bits. In other words, only the data in the first and the second columns can be stored in the same basic storage unit, e.g. the basic storage unit BX0, and the data in the other columns 103, 104 and 105 have to be stored in another 16-bit basic storage unit BX1. It is obvious that there will be 6-bit clearance between the column 102 and column 103, so the columns are not adjacent to each other. This might render errors in the subsequent accessing procedures.
Further, for different systems or platforms, their endians also differ from one another. Giving a system incorporating an 80×86 CPU as an example, the arrangement shown in FIG. 2B is referred to as "little endian", i.e. the lower bit data are stored in lower bit addresses. In FIG. 2B, three basic storage units BL, BM and BH comprise bits 0˜7, 8˜15 and 16˜23 stored in addresses (0)˜(7), (8)˜(15) and (16)˜(23), respectively. On the other hand, the arrangement shown in FIG. 2C is referred to as "big endian", i.e. the lower bit data are stored in higher bit addresses. In FIG. 2C, three basic storage units BL, BM and BH comprise bits 0˜7, 8˜15 and 16˜23 stored in addresses (16)˜(23), (8)˜(15) and (0)˜(7), respectively.
It is understood from the above description that different platforms, e.g. systems with different endians, requires different processing methods. Otherwise, the bit data will not be able to be correctly accessed.

Data access method applicable to various platforms


A method and system for dynamically adjusting packet size to decrease a delay of a streaming data transmission. A measurement is obtained by a measuring computing unit (i.e., data transmission server or client computing unit). The first measurement is either (1) a delay of a streaming data transmission being sent from the data transmission server to the client computing unit via a plurality of packets or (2) a frequency of damaged packets of the plurality of packets. The damaged packets contribute to the delay of the streaming data transmission. The packet size is adjusted by the data transmission server. The packet size adjusting includes utilizing the measurement and facilitating a reduction of the streaming data transmission delay. The delay results from noise on one or more communication link segments used by the streaming data transmission.

In conventional Transmission Control Protocol/Internet Protocol (TCP/IP)-based communication of continuous data streams (e.g., video streams) where the data receiver is separated from the data transmitter by one or more link segments on which data can be damaged (i.e., distorted), the overall communication line throughput suffers due to the fact that the longer a TCP packet is, the more likely the data is distorted. In certain data receivers such as cell phones receiving video streams, when a TCP packet for a continuous data stream is distorted (i.e., any number of bits are missing or the bits indicate an incorrect value), the entire TCP packet is dropped and a retransmission is requested. That retransmission, in turn, is also not guaranteed to be free of distortion, so subsequent retransmissions may be needed. The need for retransmissions and subsequent retransmissions lead to unacceptable data delivery delays (e.g., a delay in the outputting of a video data stream onto a display on the data receiver). In cell phone data communication, the quality of the wireless link is inferior and varies over time, leading to a substantial image delay in a video stream (e.g., a delay of several dozen seconds). A shorter TCP packet decreases the likelihood of data distortion, but increases overhead costs of network bandwidth. The overhead costs increase because shortening the packet length shortens the data portion of the packet, but does not shorten the length of a packet's header. A typical TCP packet length is about 1500 bytes with about 50 bytes being allocated to the header. In this typical case, the overhead is insignificant, but the chance of the packet being damaged is very high if the communication line is noisy. Thus, there exists a need to overcome at least one of the preceding deficiencies and limitations of the related art.

Method and system for dynamically adjusting packet size to decrease delays of streaming data transmissions on noisy transmission lines

International Business Machines Corporation


Signal-adaptive noise reduction in digital radiographic images is described herein. Embodiments comprise methods for signal-adaptive noise reduction in digital radiographic images, comprising the steps of: obtaining raw x-ray image data of an imaged object; processing the raw x-ray image data to create processed x-ray image data; inputting at least one of the raw x-ray image data and the processed x-ray image data to an image processor; developing at least one of a first intensity modulation image from the raw x-ray image data and a second intensity modulation image from the processed x-ray image data; deriving a structure-dependent noise filtered image using the processed x-ray image data; performing signal attenuation-dependent blending; and creating a noise-reduced digital x-ray image therefrom. Computer-readable mediums encoded with programming for facilitating signal-adaptive noise reduction in digital radiographic images, and digital radiographic imaging systems comprising such programming, are also described.

With applications ranging from diagnostic procedures to radiation therapy, the importance of high-performance medical imaging is immeasurable. As such, new advanced medical imaging technologies continue to be developed. Digital medical imaging techniques represent the future of medical imaging. Digital imaging systems produce far more accurate and detailed images of an object than conventional film-based imaging systems, and also allow further enhancements of the images to be made once an object is scanned.
During the display processing of images from digital radiographic imaging systems, the image noise at highly attenuated regions in the images becomes more noticeable, and can therefore decrease the perceived quality of the final images. This perceived image degradation is mainly due to the contrast enhancement that occurs in the highly attenuated regions of the image. Currently, noise reduction techniques based on image properties alone can greatly improve the perceived quality of highly attenuated regions of such images. However, that comes at the cost of having decreased contrast at lowly attenuated regions in the images, such as the lung parenchyma. Since existing systems and methods for reducing noise in digital x-ray images have such drawbacks, it would be desirable to have systems and methods for improving the displayed image quality of digital x-ray images that can reduce noise at highly attenuated regions without affecting the image contrast at relatively lowly attenuated regions. It would also be desirable to have such systems and methods that take the detected signal properties into account in a noise reduction framework, where the noise reduction framework is adaptive to the detected signal.


A system is disclosed according to the present invention that manages the process of providing a client access to a secured service. In the exemplary embodiment, the secured service is a computer system that allows the client to trade financial instruments. Management of this process includes managing execution of tasks that can be automatically executed and delegating tasks that require manual execution; communicating with entities outside of the process management system; and handling “demands,” or unexpected problems that arise in the middle of the client connectivity process.

Today's technology is capable of providing direct access to markets, allowing users to trade financial instruments on their own from almost any location. Access to this technology is highly demanded, and, therefore, it is important to quickly and efficiently provide such access to users. However, providing users with access to systems that provide direct market access is very complicated, requiring numerable steps. Conventionally, these steps have been manually managed and performed, taking up to six or more months to complete the task of providing direct market access to users. With the high state of demand for direct market access, such delays of six or more months are unacceptable.

User connectivity process management system


Embodiments of the disclosure provide systems and methods for clock duty cycle measurement. A clock signal and a complement of the clock signal are provided to a charge pump during first and second predetermined timing windows. A charge pump is operable to generate first and second output voltages in response to the clock signal and the complement of the clock signal during the first and second timing windows, respectively. In addition a predetermined positive voltage and a ground voltage are applied to the charge pump during predetermined third and fourth timing windows, respectively. The charge pump is operable to generate third and fourth output voltage signals corresponding to the predetermined positive and ground voltages during the third and fourth timing windows, respectively. The first, second, third and fourth voltages are then used to calculate the duty cycle of the clock.

1. Field of the Invention
The present invention relates in general to the field of computer circuitry. More specifically, embodiments of the invention are systems and methods for measuring a clock duty cycle without using a reference clock for calibration.
2. Description of the Related Art
The duty-cycle of a high-speed clock is a very important aspect of modern integrated circuits, such as high-performance microprocessors. For example, either the positive or the negative cycle of a clock can be used for memory access and the memory access speed is directly related to the duration of the clock pulse and thus the duty cycle. In theory, a fifty percent duty cycle clock is preferred from a phase-locked loop (PLL) and the clock distribution circuitry. However, the optimum duty cycle of a clock for maximum system performance will vary from one circuit to another due to process variation and model-to-hardware correlation.
In general it is difficult to measure the duty cycle of a clock, since any logic that is used to extract the duty cycle of a clock will also lead to duty cycle degradation of the original clock. In addition, most prior techniques for measuring the duty cycle of a clock require an off-chip reference clock for calibration.
To help optimize design, it is preferable to calculate the duty cycle of a clock using on-chip hardware. A clock duty cycle is sensitive to many different factors, including operating frequency, operating temperature, supply voltage, circuit design style, circuit loading, and process (e.g., variations in the doping, threshold voltage, mobility, gate oxide thickness, etc. across single and/or multiple wafers). Because so many different factors may affect duty cycle, it is important to be able to accurately measure clock duty cycle at the point of use on the chip under actual operating conditions.
It is apparent, therefore, that there is a need for an improved system and method for measuring the duty cycle of a clock using on-chip hardware without a reference clock.

Clock duty cycle measurement with charge pump without using reference clock calibration


Techniques are described for accurately and efficiently emulating an instruction processor having a write buffer. The described techniques may be utilized to quickly develop an emulated instruction processor that provides a fully-functional write buffer interface in an efficient and elegant manner. For example, a system is described that includes a computing system that provides an emulation environment, and software executing within the emulation environment that emulates an instruction processor having a write buffer interface and a memory interface. The software emulates the instruction processor by selectively outputting a write request on the write buffer interface or the memory interface in response to an emulation control instruction embedded within an instruction stream.

A computer system typically involves multiple components working in cooperation to perform a task. For example, a computer system may include one or more co-operating instruction processors. These instruction processors may be supported by communication busses, cache memories, shared and dedicated memories, input/output (I/O) devices, interface hardware, and the like.
The process of designing and ensuring proper functionality of these constituent components, i.e., development process, is involved and time consuming. In addition, the demand for computer systems of increasing complexity, such as computer systems that can provide more throughput, further increase the time and resources required to design and ensure the proper functionality of components.
In order to expedite the design process, emulation tools are often used to assist in testing the functionality of a component or system being designed. During this process, one or more emulation modules are often developed to interface with and test the functionality of the components being designed. For example, a designer currently developing a memory architecture may use an emulation module to mimic the functionality of an associated instruction processor. The emulated instruction processor may be used, for example, to interact with the memory architecture being developed in a manner that conforms to that of an actual instruction processor in order to test the operation of the memory architecture. As the processor itself may also not yet be implemented, the use of an emulated instruction processor allows the development of the actual instruction processor and the memory architecture to proceed concurrently. In this manner, the development period needed to complete the overall computer system may be compressed.
A designer may develop an emulation module for a particular component by utilizing an editor or other software application to describe the functionality of the component in accordance with a hardware description language (HDL). Examples of widely-used HDLs include the Very high-speed integrated circuits Hardware Description Language (VHDL) and Verilog™, which is described in the IEEE Verilog 1364-2000 standard. These languages support syntaxes that appear similar to software programming languages, such as C++ and Java, and allow the designer to define and simulate components using high-level code by describing the structure and behavior of components.
While the use of emulation can greatly aid in the development of the computer system, even the design of operationally-correct emulation modules requires time and resources. In other words, development of an emulated instruction processor that correctly mimics the functionality of an actual instruction processor is a complex and time-consuming process. For example, one feature of an instruction processor that may require significant resources to accurately emulate is the incorporation of a write buffer.
A write buffer is a type of first in, first out (FIFO) queue that typically resides within the instruction processor and provides storage space for pending write requests. The instruction processor typically issues the write requests queued in the write buffer as "pre-fetch" write requests to a cache via a dedicated write buffer interface, and subsequently issues the corresponding "real" write request to the cache via a memory interface. The pre-fetch write requests are typically used to reserve ownership of cache lines within the cache prior to the issuance of the actual write requests. In this manner, the execution of the subsequent write request may be accelerated as the instruction processor has already reserved ownership of the cache lines. Time-saving techniques directed to the efficient and accurate development and configuration of an emulated instruction processor having write buffers may further reduce the overall time necessary to develop a computer system.

Instruction processor write buffer emulation using embedded emulation control instructions


The present invention relates to salts comprising novel aryl-alkyl-substituted imidazolium and triazolium cations and arbitrary anions. The invention further relates to methods for the chemical conversion and separation of substances, comprising the salts according to the invention as solvents, solvent additives, or extraction means, and to the use of the salts according to the invention, for example as solvents or solvent additives in chemical reactions, as extracting agents for the separation of substances, or for storing hydrogen. According to the invention, the object is achieved by salts of the general formula (I), where X— is an anion, Y1 and Y2 are CH, or Y1 is CH and Y2 is N, or Y1 is N and Y2 is CH, n is a number from 1 up to an including 18, Q is selected from —CH3, —OH, —ORx, —S03H, —S03Rx, —COOH, —COORx, —CORx, NH2, —NHRx, —N(Rx)2, and —CH(Rx)2, Z is H or Rx, R1, R2, R3, R4 and R5 independently from each other are —H, -halogen, —N02, —NH2, —NHRx, —N(Rx)2, —Rx, —COORx or —ORx, where Rx is an optionally substituted and/or branched C1 to C18-alkyl group, excluding compounds of the general formula (I), where Y1 and Y2 are CH and R1, R2, R3, R4 and R5 are H, excluding compounds of the general formula (I), where Y1 and Y2 are CH, R1=R3=R5=CH3 is true, n=1, 2, 6 and Q=CH3 is true, excluding compounds of the general formula (I), where Y1 is CH and Y2 is N, R1, R2, R3, R4 and R5 are H, n=1 is true, and Q=CH3 is true, and excluding compounds of the general formula (I), where Y1 and Y2 are CH, R1, R2, R4, R5=H is true, R3=ORx is true, and Rx is a hydrocarbon having 3 or 12 carbon atoms.

The present invention concerns salts from new aryl-alkyl-substituted imidazolium and triazolium cations and any anions. The invention concerns furthermore methods for the chemical reaction and separation of substances comprising the inventive salts as solvents, solvent additives, or extraction agents as well as the use of the inventive salts, for example, as Solvents or solvent additives in chemical reactions, as extraction agents for the separation of substances or for the storage of hydrogen.
Nowadays, organic solvents find applications in many different areas, beginning with chemistry, but also in biology and in material development. However, in traditional catalytic processes organic solvents as a result of their volatility, flammability and toxicity often bring about the problem that dangers relating safety, health and environment must be prevented with costly technical measures (cf. Wasserscheid/Welton, "Ionic liquids in synthesis", Wiley-VCH 2007).
Hence, new environmentally friendly synthesis methods that require no solvents or use environmentally friendly alternative solvents become more and more important. In this context, attention has focused in recent years particularly on ionic liquids.
The definition of ionic liquids ("ionic liquids", "ILs") concerns substances that consist completely of organic cations and organic or inorganic anions and have, in addition, a low melting point of less than 100° C. and a relatively low viscosity.
Ionic liquids exhibit further advantageous properties, for example, low vapor pressures, low combustibility as well as an adjustable polarity and miscibility with other organic and inorganic substances. Hence, they represent in synthesis and homogeneous catalysis an interesting alternative to the organic solvents used today. The low vapor pressure, the low flammability linked therewith, the low toxicity and variability of these compounds makes them ideal "green" solvents for a plurality of chemical processes.
Known ionic liquids contain as a cation, e.g., alkyl ammonium, alkyl phosphonium, N,N′ dialkyl imidazolium and N-alkyl pyridinium cations:

Up to now, however, there is no reliable way to predict the melting points of organic salts. Discovering new organic salts that fulfill the definition of ionic liquids is possible currently only experimentally.
The electronic properties of the conventionally employed ionic liquids available commercially can be changed only minimally.
From the prior art (e.g., WO 03/074494 A1, DE 10 2004 060 247 A1 or EP 1 201 657 A1) N,N′-substituted imidazolium and triazolium salts are known which are used as ionic liquids. The individual compounds disclosed therein are aliphatic substituted imidazolium and triazolium salts in which the sp3-hybridized substituents on the nitrogen atoms reduce the possibilities of influencing the system to the inductive effects. Mesomeric effects cannot be used.
Presently, the research activities focus extensively on the synthesis of new anions. Thus, WO 03/074494 A1 discloses ionic liquids with anions free of halogen; WO 2007/131498 A2 discloses hydrophobic anions; WO 2004/054991 A1 discloses those with [N(CF3)2−] anions, EP 1 512 460 A1 those with thiocyanate anions; and WO 2004/096776 A1 those with alkyl sulfate anions.
It is therefore the object of the invention to provide salts with new organic cations whose electronic properties can be varied in a targeted fashion and whose melting points and solution properties are adjustable so that they are suitable for use as ionic liquids.

Salts comprising aryl-alkyl-substituted imidazolium and triazolium cations and the use thereof


A stepping motor control system for a recording apparatus which uses a stepping motor as a driving source of a carriage with a recording head, has a stepping motor driving circuit for exciting the phases of the stepping motor, and a control circuit for transferring data corresponding to a predetermined stepping motor driving curve to the driving circuit, so as to easily obtain a stepping motor driving curve that can suppress vibrations, and the driving curve is formed from an Nth-order specific formula having two or more inflection points.

1. Field of the Invention
The present invention relates to a stepping motor control system suitable for driving, e.g., a carriage of a recording apparatus.
2. Related Background Art
In recent years, stepping motors are popularly used as driving sources for industrial equipment since they have high rotational positioning precision. Among industrial equipment, stepping motors are popularly used as driving motors for so-called OA equipment.
In recording apparatuses as well, stepping motors are often used as driving sources of carriages with recording heads. Upon driving a carriage, a stepping motor is normally used in the slew section outside the self-activation section. Hence, the stepping motor is made to rise at a low frequency in the self-activation section, and accelerated to a predetermined use frequency. To stop the stepping motor, the stepping motor is decelerated from the predetermined use frequency, and made to fall to the low frequency in the self-activation section. The above-mentioned driving method is normally used in a stepping motor for driving a carriage. As such frequency vs. time acceleration/deceleration curve of the stepping motor, a linear curve, exponential function curve, S-shaped curve, and the like are normally used since they have high torque characteristics and vibration characteristics. Furthermore, in order to improve the vibration characteristics and the like in a limited arrangement, for example, a control method of supplying a pulse with a long duration that deviates from the predetermined acceleration/deceleration curve during acceleration is used.
However, since the S-shaped driving curve is calculated from a higher-order (third-order or higher) equation, elaborate and time-consuming calculations are required. Furthermore, innumerable curves are available depending on the portions of the curve to be used as the driving curve, how a large number of variables and parameters are set, and the like. Also, calculations and confirmation of such variable, parameters, and the like require much labor. On the other hand, a manual input method that does not use any equations requires much labor due to repeated trials and errors. For the above-mentioned reasons, demand has arisen for a method that can easily form a good driving curve within a short period of time.

Stepper motor control system which uses pulse frequencies that vary according to a non-liner curve


A full-color OLED display device comprised of a substrate; an array of light-emitting elements, each element comprised of a first EL unit positioned between and in electrical contact with a first pair of electrodes and a second EL unit positioned between and in electrical contact with a second pair of electrodes and located above or below the first EL unit, wherein the first EL unit emits light primarily in only two of the red, green and blue portions of the visible spectrum, and the second EL unit emits light at least in the remaining third portion of the visible spectrum; and a component for selectively filtering the light produced by the first EL unit to filter light from one of the only two of the red, green and blue portions of the visible spectrum in some light-emitting elements and to filter light from the other of the only two of the red, green and blue portions of the visible spectrum in some other light-emitting elements.

Light-emitting, flat-panel display devices are used for a number of applications such as general illumination light sources, decorative light sources, and information displays. Organic light-emitting diode (OLED) display devices often form an array of differently colored, light-emitting elements that are either arranged spatially on a single plane as discussed by U.S. Pat. No. 5,294,869 issued to Tang and Littman, entitled "Organic electroluminescent multicolor image display device" or are composed of a number of stacked, individually-addressable emissive layers as has been discussed by U.S. Pat. No. 5,703,436 issued to Forrest et al., entitled "Transparent Contacts for Organic Devices". To form large, high-resolution devices of either type presents significant manufacturing barriers.
The structure of an OLED typically comprises, in sequence, an anode, an organic electroluminescent (EL) medium, and a cathode. The organic EL medium disposed between the anode and the cathode is commonly comprised of an organic hole-transporting layer (HTL) and an organic electron-transporting layer (ETL). Holes and electrons recombine and emit light in the ETL near the interface of HTL/ETL. Tang et al., "Organic electroluminescent diodes", Applied Physics Letters, 51, 913 (1987), and U.S. Pat. No. 4,769,292, demonstrated highly efficient OLEDs using such a layer structure. Since then, numerous OLEDs with alternative layer structures have been disclosed. For example, there are three-layer OLEDs that contain an organic light-emitting layer (LEL) between the HTL and the ETL, such as that disclosed by Adachi et al., "Electroluminescence in Organic Films with Three-Layer Structure", Japanese Journal of Applied Physics, 27, L269 (1988), and by Tang et al., "Electroluminescence of doped organic thin films", Journal of Applied Physics, 65, 3610 (1989). The LEL commonly includes a host material doped with a guest material wherein the layer structures are denoted as HTL/LEL/ETL. Further, there are other multi-layer OLEDs that contain a hole-injecting layer (HIL), and/or an electron-injecting layer (EIL), and/or a hole-blocking layer, and/or an electron-blocking layer in the devices. These structures have further resulted in improved device performance. The term "EL unit" may be used to describe the layers between and in electrical contact with a pair of electrodes, and will include at least one light-emitting layer, and more typically comprises, in sequence, a hole-transport layer, a light-emitting layer, and an electron-transport layer, denoted in brief as HTL/LEL/ETL.
The formation of a full-color display device through the spatial arrangement of different colors of emissive organic materials on a single plane requires at least three different organic materials to be deposited in a mosaic on a single plane. This mosaic must be deposited such that any one of the organic materials does not overlap a second organic material and further that each organic material appropriately overlaps electrodes that are formed to drive the organic display. Methods such as vapor deposition through a shadow mask are often used to accomplish this task. Unfortunately, accurate alignment of shadow masks with the appropriate electrodes on the substrate requires a significant period of time to accomplish, slowing manufacturing. Of even greater concern is the fact that the shadow masks are typically not thermally stable and, therefore, it is difficult to maintain the exact tolerances necessary to correctly pattern the three-or-more colors of organic light-emitting materials onto a substrate. Further, the amount of thermal expansion that can occur with a shadow mask increases with increases in mask area, making this process very difficult, if not impossible, when forming OLED displays on large substrates. Other methods to pattern organic materials onto a substrate have been proposed and are a subject of research. However, only evaporation through a shadow mask has been successfully demonstrated in high-volume manufacturing.
To overcome this problem, a single organic emitter may be deposited on a single plane, this organic emitter providing either a broadband emission or multiple spectral peaks. Red, green and blue color filters may then be used to filter the emission from the single emitter to form red, green, and blue subpixels. While this method has the advantage that it allows a full-color display to be made without requiring patterning of the deposited organic material, the color filters must provide a narrow pass band to form a full-color display, significantly reducing the efficiency of the display. In such a display, it is typical that less than one third of the light that is produced by the organic emitter is passed through the color filters.
It is possible to use other color filter arrangements to improve the efficiency of an OLED with red, green and blue color filters. One particularly useful approach utilizes an unfiltered white subpixel in addition to the subpixels that are filtered using red, green, and blue color filters as described in US Patent Application US2004/0113875 assigned to Miller et al. and entitled "Color OLED display with improved power efficiency". Using this approach, it has been shown that the efficiency of the display device can be doubled when compared to the use of subpixels having red, green, and blue color filters. In this display configuration nearly two-thirds of the light that is produced by the organic emitter is passed through the color filters when displaying typical images. Unfortunately, the layout of the underlying circuitry required to drive a display employing a fourth subpixel in each pixel limits the resolution of the display device.
Alternatively to patterning multiple colors of emitters on a single plane, separately addressable layers of red, green and blue emitters may be formed in a passive-matrix stacked OLED display structure as described by U.S. Pat. No. 5,703,436 issued to Forrest et al., entitled "Transparent Contacts for Organic Devices". A display device of this type is created by forming multiple, alternating layers of organic light-emitting material and materials that are used to form an electrode over a base electrode as shown in FIG. 1. Referring to FIG. 1, a display device of this type is formed by forming a first electrode 12 on a substrate 10. An EL unit 14 (comprised of one or more light-emitting organic material layers, and optionally additional material layers as further discussed below) is then formed over the first electrode, followed by a second electrode 16. Successive EL units 18 and 22 and electrodes 20 and 24 are then formed over this second electrode 16. To form a full-color device in this way requires the formation of at least three EL units 14, 18, and 22 and four electrodes 12, 16, 20, and 24. This method has the advantage that it does not, necessarily; require the organic materials to be spatially patterned. That is, if three independently addressable layers of light-emitting material can be formed, one emitting red light, a second emitting green light, and a third emitting blue light, then a full-color display may be formed without spatially patterning the EL materials. The display device can also theoretically be higher in resolution since the red, green, and blue subpixels are formed in the same spatial location.
Unfortunately, a robust manufacturing process for forming display devices of this type has not been demonstrated and active-matrix structures for forming such displays have not been disclosed. Issues such as the need to connect four stacked electrodes to circuitry on a substrate; the lack of electrode materials that are substantially transparent and have a high enough work function to serve as a cathode; and the need for TFT structures that can be used and connected to the four separate electrodes all prohibit the robust manufacturing of devices having three or more stacks.
There is a need, therefore, for an OLED device structure that avoids the need for patterning different OLED materials, has a high efficiency, has the capability for forming a high resolution display device, and that is simpler to construct than the three-or-more layer stacked display device.


A method of coating a ceramic matrix composite fiber is disclosed. The method includes passing the composite fiber through a reaction zone along a path substantially parallel to a longitudinal axis of the reaction zone. It also includes passing a flow of a fiber coating reactant through the reaction zone. Further, the method includes disrupting a portion of the flow of the fiber coating reactant from a path substantially parallel to a fiber path to create a mixing flow adjacent the composite fiber.

The invention relates to a method and reactor for applying a coating to a fiber by chemical vapor deposition (CVD).
Fiber reinforced ceramic matrix composites (CMCs) are formed of continuous uniaxial or woven fibers of ceramic material embedded in a ceramic matrix. These materials are designed to have a weak fiber-matrix bond strength. When a CMC is loaded above a stress that initiates cracks in the matrix, the fibers debond from the matrix allowing fiber/matrix sliding without fiber fracture. The fibers bridge the matrix crack and transfer load to the surrounding matrix by transferring tensile stress to frictional interfacial shear force.
Conventional manufacturing processes for CMCs have comprised, first, preparing a flowable suspension of the ceramic matrix material in powdered form, coating or immersing the inorganic fibers (usually long fiber tows) with the suspension, and collecting the coated fiber tows into a mat or other shape. The impregnated fibers and shapes made therefrom are at this stage of the process commonly termed "prepreg." The prepreg can be reshaped as desired but is ultimately formed into a preform for the desired composite article. The preform is then subjected to a burn-out step wherein organic or other fugitive components present in the coating are removed from the preform. The debindered preform is finally consolidated into a dense composite material by reaction with molten silicon at high temperature.
Preferred fibers for producing CMCs are of relatively small diameter (8-15 microns). The fibers are wrapped in tows of several hundred individual filaments. The coating is applied to the fibers for several purposes such as to protect them during composite processing, to modify fiber-matrix interface stresses and to promote or prevent mechanical and/or chemical bonding of the fiber and matrix. Chemical vapor deposition (CVD) is a preferred technique for production of coatings on fibers used for production of ceramic matrix composites.
The coating process must uniformly coat all fibers. While this is possible when the fibers are individual filaments, it is very difficult to achieve when the fibers are collected into tows and woven, braided or knitted into fabrics. Adjacent and neighboring fibers block the flow of gaseous coating reactant to the fiber surfaces and block counterflow of reaction by-product gases away from the fibers. There is a need for an improved CVD process and reactor for uniformly coating CMC fibers.

Method of coating a ceramic matrix composite fiber


The invention concerns a bridging system comprising several uniform bridge section in the form of track supports (1). The width of the bridge can be continuously adjusted with telescoping pipes ( 2 ). The stationary ramps ( 3 ) on the track support are slotted like a comb and, once the have been assembled and connected to the pivoted-out lower truss system (4), can accommodate any compression forces and bending moments that occur when traveled. Since each track support is the same shape, the bridging system has a smoothly curving upper roadway edge.. The traction component (5) in each track support travels back and forth between pivoting stays (9) provided with connectors (8) and the overall lower truss system can be pivoted into the track support.. This bridging system, which consists of modular track supports (1), is outstanding for its compact traveling state and few connectors and can be positioned by appropriate transporting and laying equipment.

The invention concerns a bridging system consisting of several uniform bridge sections in the form of track supports. One bridge section or several bridge sections together constitute a bridge.
A take-apart latticework bridge is known from German 3 814 502. Its modular components comprise two roadway slabs connected by transverse girders.
One bridge component consists of two roadway slabs, two lower flanges, and eight diagonal struts. The diagonal struts and lower flanges in each bridge component telescope and can be locked into position.
The diagonal struts can be rotated to unlock them. Once it has been pulled apart or pushed together, the rod can be locked back into another position by being rotated into another groove.
Assembling a bridge 14 m long from two bridge components requires much rotating to unlock and relock eight diagonal struts.
A 40 m long bridge will then consist for example of six bridge components, and 40 diagonal struts will have to be rotated many times to unlock and relock them during disassembly, and a total of eight diagonal struts, two per bridge component, will have to be dismounted. This approach to assembling bridge components demands an enormous expenditure of time.

Bridging system consisting of track supports


A method and apparatus for protecting spaced high pressure seals in a high pressure chamber from damage caused by retained high pressure between the seals after the high pressure in the chamber has been released. A one-way check valve is coupled to the area between the seals and to the interior of the high pressure chamber to automatically vent the area between the seals only when the high pressure in the chamber has been released or removed.

High pressure devices such as compressors have component parts which are fitted together. Because of the high pressure that the unit contains, the parts that are fitted together generally have seals therebetween. In high pressure systems such as compressors, the pressure can gradually seep past a seal over extended periods of time. Thus, generally, two seals are placed in spaced relationship to each other to form an area in which the fluid that bypasses the first seal can collect. The second seal forms an effective barrier against further loss of pressure.
When the unit such as the compressor is shut down or stopped, it is depressurized inside. However, the pressure that is caught between the two seals remains and provides a constant prolonged pressure against the two seals creating undue wear and premature failure of the seals such as O-rings.
The present invention overcomes the disadvantages of the prior art by providing a system and method for automatically depressurizing the area between the two O-ring seals after the compressor unit has been stopped or shut down. In particular, a passageway connects the space between the two seals and formed by the adjoining surfaces to the interior of the unit such as a compressor. A one-way check valve is located in the passageway so as to allow pressure to enter the interior of the unit such as the compressor from the space between the seals but not to allow pressure to leave the compressor into the passageway during operation of the compressor. When the compressor is in operation, the passageway is held closed by a spring loaded sealing head in the check valve. Pressure in the compressor assists in holding the check valve in the closed position. Internal pressure in the unit seeps through the inner O-ring seal, through permeation, to a cavity between the inner and outer O-ring seals formed by the two surfaces joined together to form the chamber.
When the compressor is stopped or shut down and the inside of the casing is depressurized, the high pressure gas or fluid is trapped between the inner and outer O-ring seals. The trapped pressure follows the passageway connecting the space between the inner and outer O-ring seals toward the interior of the compressor. A check valve is placed in the passageway which will open to the internal side of the compressor allowing the high pressure trapped between the O-rings to automatically vent down when the compressor is depressurized internally, thus protecting and prolonging the use of the O-ring seals.
Thus, it is an object of the present invention to provide a device and method for depressurizing the area between two spaced high pressure seals such that any high pressure that seeps into the cavity between the seals during operation of the compressor or other device will not be maintained in the space to cause deterioration of the seals when the device is shut down.
It is another object of the present invention to couple a one-way check valve from the space between the seals to the interior of the compressor such that when the compressor is depressurized any high pressure remaining between the seals is automatically vented back into the interior of the compressor unit.