The invention relates to a nonwoven highloft flame barrier well suited for use in mattress, upholstered furniture and other end use applications where a highloft nonwoven material is desired for flame barrier purposes. A preferred nonwoven highloft flame barrier of the invention comprises a blend of fibers, that are inherently fire resistant and essentially nonshrinking to direct flame, with melamine fibers being preferred either alone or in conjunction with, for example, viscose rayon based fibers, fibers extruded from polymers made with halogenated monomers and preferably low-melt binder fibers, which are thermally activated in a highloft manufacturing process to provide low bulk density, resiliency and insulation properties in the end use application. The preferred fiber blends are designed to withstand extended periods of time exposed to open flame with minimal shrinkage of the char barrier; thereby preventing a flames from “breaking through” the char barrier and igniting underlying materials. Other component fibers can also, optionally, be included such as: natural fibers, to improve product economics in the end use application. The highloft flame barrier of this invention also allows for the manufacture of open flame resistant composite articles, while also permitting the continued use of conventional non-flame retardant dress cover fabrics, conventional non-flame retardant fiberfills and conventional non-flame retardant polyurethane foams.

It is known in the textile industry to produce fire resistant products for use in upholstered furniture, mattresses, pillows, bedspreads, comforters, quilts, mattress pads, automotive seating, public transportation seating, aircraft seating and the like, using woven, needlepunched or spunlace nonwoven or knit fabrics formed of natural or synthetic fibers, and then treating these fabrics with fire retarding chemicals. Conventional fire retarding (FR) chemicals include halogen-based, phosphorus-based and/or antimony-based chemicals. Unfortunately, such treated fabrics are heavier than similar types of non-fire retardant fabrics, and have reduced wear life. Although FR chemically treated fabrics will self-extinguish and exhibit limited melt behavior when a flame is removed, they do not perform well as a flame barrier against large direct flame assaults for even short periods of time. Typically FR chemically treated fabrics form brittle chars, shrink and crack open after a short exposure to a direct flame. This exposes the underlying material (e.g., polyester fiberfill and/or polyurethane foam), in a composite article, to the open flame. This fabric cracking and shrinking behavior may allow the underlying materials to ignite. When these fabrics made with FR treated cotton, FR polyester and other FR treated fabrics are used in composite articles such as upholstered furniture and mattresses, these composite articles are deemed unsuited for passing the more stringent open flame tests such as: California Test Bulletin 133 (January 1991) (Cal TB133), California Test Bulletin 129 "Flammability Test Procedure for Mattresses for use in Public Buildings", (October 1992) (Cal TB129) and British Standard 5852—Crib 5 (August 1982) (BS5852) without the use of additional flame barrier or FR backcoating materials.
Some of the flame barrier fabrics currently being used with the goal to pass the more stringent open flame tests, such as Cal TB129 and Cal TB133 include:    1) A woven polymer coated 100% fiberglass flame barrier (Sandel® Fabric, Sandel International Inc.)    2) A woven or knit core-spun yarn based flame barrier, where natural and/or synthetic fibers are wrapped around a multifilament fiberglass core and then optionally treated with FR chemicals and/or a coating of thermoplastic polyvinyl halide composition, such as polyvinyl chloride (Firegard® Seating Barriers, Intek; Firegard® Brand Products, Chiquola Fabrics, LLC)    3) A nonwoven hydroentangled spunlace flame barrier made of 100% p-aramid (Thermablock™ Kevlar® Z-11, DuPont Company).    4) A woven or knit core-spun yarn based flame barrier where natural and/or synthetic fibers are wrapped around a multifilament and/or spun p-aramid core yarn and then optionally treated with FR chemicals and/or a coating of thermoplastic polyvinyl halide composition, such as polyvinyl chloride (Firegard® Seating Barriers, Intek; Firegard® Brand Products, Chiquola Fabrics, LLC)
The disadvantages of the above mentioned flame barrier solutions for more stringent open-flame applications in mattresses, upholstered furniture and other fiber-filled applications include:                a) Woven flame barriers, especially when coated with FR materials, impart a stiff "hand" to the composite article, which negatively affect the feel of the final product.        b) Prior art woven, nonwoven and knit flame barriers must be either laminated to the decorative fabric or double upholstered during manufacturing. This increases the number and complication of the dress cover fabrics, thereby increasing manufacturing costs.        c) 100% fiberglass flame barriers have poor durability due to glass-to-glass abrasion.        d) Woven and knit flame barriers made with natural fiber wrapped core-spun yarns must be made in heavy weight constructions (i.e. ˜10 opsy or 336 g/m2) to be effective flame barriers, and can negatively affect the feel of the composite article.        e) Natural fiber wrapped core-spun yarn fabrics require additional FR chemical treatments and/or coatings of a thermoplastic polyvinyl halide composition, such as polyvinyl chloride to be effective in passing the more stringent open-flame tests. This negatively impacts the workplace by having to handle these chemicals and increases the exposure of chemicals to the consumer who uses the composite article.        f) Hydroentangled nonwoven spunlace flame barriers, containing significant amounts of p-aramid fibers, impart a yellow color to the flame barrier and negatively effect the look of the composite article, especially when used directly under white or light-colored decorative upholstery and/or mattress ticking fabrics.        g) Woven and knit flame barriers add a significant cost to the composite article because they require a yarn formation step, which is eliminated in the formation of a nonwoven flame barrier of the invention.


The invention is directed to an apparatus for calibrating an output of an image output device, comprising an image input device configured to image an output of the image output device; and a test pattern generator having an output of a dynamic test patch area and a grating area connected to an input of the image output device and responsive to the image input device for adjusting an intensity level of the dynamic test patch area to match an average intensity level of the grating area.

Continuing advances in computers and digital communications have resulted in the proliferation of digital imagery, such images including, for example, still images, full motion video, graphics incorporated into on-line catalogs, advertisements and web pages. While substantial effort has been expended to ensure that data storage and transmission provides an accurate representation of the original data, fidelity of a rendered image with respect to the original or a desired image has been largely left to the individual user.
Prior techniques to ensure the fidelity of an output device such as a video monitor or color printer accurately represents a desired image relied heavily upon specialized devices such as CRT color analyzers, such as the Minolta CA-100 or the Sencore CPT 288 color analyzer. These devices may be capable of measuring the exact gain or gamma function relating display parameters to actual screen output. Such devices have typically been costly and relegated to manufacturing and other test facilities when the cost is justified. However, consumer and small scale usage has not been adequately addressed. This has become a problem with the ever increasing usage of images and graphics in which image fidelity is increasingly important.
At least one software manufacture includes in their game programs a method to calibrate screen video without a photometer or other equipment, instead using just the naked eye. According to this method, a square area is displayed on the screen and the brightness of the square is adjusted until it is just invisible. From this adjustment, an estimate is made of the black level of the screen and graphics are re-calibrated so that display presentation is optimized. However, this method is subjective and requires substantial user effort and experimentation.
Other approaches to calibrating an output device are described in U.S. Pat. Nos. 5,012,163 and 5,381,309 assigned in common with the present application and incorporated herein by reference in their entireties.
There is a need for a simplified method and an inexpensive apparatus for calibrating color rendition of an output device such as a video monitor or printer to ensure image fidelity and, in particular, maintain accurate and consistent color rendition of images.

Digital camera for image device calibration

Hewlett-Packard Development Company, L.P.


A Pressure Sensing Apparatus is disclosed. Also disclosed is an apparatus that provides increased pressure sensitivity without added cost and complexity in the electronic detector circuitry. The apparatus further is less sensitive to gravity, vibrations or other external influences. It is a still further object that the apparatus be available with curved bellow head, formed with either concave or convex reflective surfaces. Other versions of the apparatus may have a deflectable focusing diaphragm that permits pressure detection responsive to the curvature of the diaphragm in response to pressure differentials across the diaphragm.

1. Field of the Invention
This invention relates generally to pressure sensors and, more specifically, to a Pressure Sensing Apparatus.
2. Description of Related Art
The bellows-type pressure sensor is widely used in high sensitivity applications. Essentially, what is involved is a very small bellow that is configured to reflect light onto a detector. When the bellow stretches or contracts in response to a pressure change, the detector will sense a corresponding change in the light intensity.
FIG. 1 is a perspective view of a prior art bellow assembly 10. As can be seen, from its outer dimensions, the bellow assembly 10 comprises a stem 12 from which extends the bellow section 14 which terminates in the head 16. The bellow section 14 is formed somewhat like an accordion, such that the bellow assembly 10 can stretch and shrink in response to changes in external forces. If we now turn to FIG. 2, we can examine the details of how this bellow assembly 10 functions to detect pressure.
FIG. 2 is a partial cutaway side view of the bellow assembly 10 of FIG. 1. Again we can see that the bellow section 14 extends from the stem 12 and terminates in the head 16. In this current embodiment the head 16 comprises a reflector 18 formed on its inner surface. Within the bellow section 14 is conventionally located a light detector 20 mounted on a stand 22. Also found within the bellow section 14 is a light emitter 24. The light emitter is configured to transmit light to the reflector 18 where it is in turn reflected towards the light detector 20. In a conventional bellow assembly pressure detector 10, the light detector 20 is sensitive enough to detect a change in light intensity in response to a change in bellow length 26. It should be noticed that in this conventional design, the reflector 18 has always been substantially flat. As such, the reflective light does not converge in any sort of focal point but instead essentially reflects outward in a Gaussean distribution and is spread into a wide area at the depth of the receiver 20; when the reflector moves towards the receiver 20, reflected areas become smaller (in effect focusing the signal). If one imagines that the bellow assembly 10 has an internal pressure 1 (which may be effectively zero) and the bellow assembly 10 is located within another volume at a unknown pressure PX, as PX is changed, the bellow length 26 will also change to some length determined by the pressure difference and the physical properties of the bellow. It is this bellow length change 26 that is detected by the detector 20 and converted into an electrical signal for display to the user. FIG. 3 depicts further information about this prior art device.
FIG. 3 is a partial cutaway side view of a conventional bellow-type pressure sensor 30 of the present invention. As can be seen, bellow assembly 10 is typically located within a chamber 28. If we imagine that the bellow assembly 10 is isolated from the chamber 28 and that the chamber 28 includes a sensor tube 32 for sensing an external pressure, we can appreciate that when the sensor tube 32 is placed in a location such that the pressure PX changes from some reference pressure, and the bellows 10 later extend or contract while the internal pressure P1 seeks to reach equilibrium with the sensed or unknown pressure PX. If we now turn to FIGS. 4A through 4C we can discuss the operation of the prior device more fully.
FIG. 4A is a depiction of the signal path of the bellow assembly 10 of FIGS. 1, 2 and 3. In this simplified drawing, the reflector 18 is shown at a distance LX1 from the detector 20. We will assume at this point that LX1 defines the at rest condition of the bellow 10. As can be seen, the transmitted light 34 from the transmitter (not shown) strikes the reflector 18 and is reflected back as reflected light 36. As discussed above, it should be understood that substantially all of the transmitted light 34 is returned along the identical path of its arrival 36. Some light however, will scatter as a result of surface irregularities on the reflector 18 and it is this light that is most likely received by the detector 20 (and therefore may contribute to the dynamic range). If we turn to FIG. 4B we can see that when the sensed pressure changes, the distance between the reflector 18 and the detector 20 changes to LX2.
FIG. 4B is a depiction of the device of FIG. 4A after a pressure change has occurred. It should be casually apparent that the reflected light 36 is not substantially changed by the change in the location of the reflector 18. In fact, in order to sense this changed distance, detector 20 must be extremely sensitive (and therefore expensive). Even still, this design will provide a fairly responsive and sensitive pressure detector having a dynamic range in the area of 2 dB. If we now turn to FIG. 4C we can see yet another limitation of the prior sensor.
FIG. 4C is a depiction of the device of FIGS. 4A and 4B when the device is experiencing off-axis deflection. As can well be imagined, the bellow 10 in order to be sensitive, is formed from very thin-walled material. As such, it is affected by external forces including vibrations, gravity and other acceleration and it is common for these external forces to result in an off-axis deflection θy. As can be seen here, while the transmitted light 34 has not changed, when a theoretical deflection θy is caused in the bellow 10, the reflected light 36 tends to be directed away from the detector 20. As such, where the sensor is experiencing vibrations they might actually be sensed as pressure changes but in fact this is not necessarily the case. This, again, adds expense because the detector must be isolated for many external acceleration-type forces.
What is needed therefore, is an improved pressure sensor that will increase responsiveness of the detector while reducing the need for an extremely sensitive detector. It would further be desirable if the improved sensor was less sensitive to off-axis deflection.


A method is provided of forming a bipolar transistor device. The method comprises depositing a collector dielectric layer over a substrate in a collector active region, depositing a dielectric anti-reflective (DARC) layer over the collector dielectric layer, dry etching away a base opening in the DARC layer, and wet etching away a portion of the collector dielectric layer in the base opening to provide an extended base opening to the substrate. The method further comprises performing a base deposition to form a base epitaxy region in the extended base opening and extending over first and second portions of the DARC layer that remains as a result of the dry etching away the base opening in the DARC layer, and forming an emitter region over the base epitaxy region.

Silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) and complementary metal oxide semiconductors (CMOS) combined together and referred to as BiCMOS circuits and systems are one of the most promising and ready technologies for ultra-high frequency applications in the radio frequency (RF) and terahertz (THz) range. SiGe BiCMOS devices and circuits have been demonstrated for frequencies as high as 600 GHz, and are capable of integrating multiple speed and power devices in single integrated circuits. The frequency and power ranges are tuned for a particular application by altering the device geometry (smaller devices being for higher frequency applications) and the base epitaxy thickness (thinner epitaxy being for higher frequency applications).
However, the processing of SiGe BiCMOS comprises several steps that require additional consideration compared to conventional processes. Importantly, deposition steps require underlying surfaces to be pristine silicon surfaces to ensure devices and circuits function properly and material is not wasted. Additionally, the multiple surfaces and subsequent deposition steps need to be uniform and repeatable over large areas. To ensure a pristine surface typically requires a cleaning step immediately prior to the layer deposition, but in SiGe BiCMOS structures an oxide layer with a window down to the substrate is typically present whose geometry is a critical dimension for performance. Thus, designing a process flow ensuring retention of that geometric integrity is a crucial enabling technology for reliable SiGe BiCMOS production. A hard mask layer can be introduced, but the usual layers used for hard masking are typically not appropriate. For example, silicon nitride would be a candidate, but its high permittivity increases the SiGe HBT base-to-collector capacitance (Cbc) that directly reduces device frequency performance.

Method of making bipolar junction transistor by forming base epitaxy region on etched opening in DARC layer


In one form, a method for managing message flow includes processing messages concurrently by processing nodes in a computer software application. The processing nodes include at least one set of lock acquisition, system resource access and lock release nodes interconnected in a flow path. In such a set, the nodes are interconnected in a flow path and process a respective one of the messages in a sequence defined by the flow path. The processing includes granting access to a system resource exclusively for the set's respective message responsive to the lock acquisition node processing its respective message. The system resource is accessed for the message responsive to the set's system resource node processing the message. The accessing of the resource for the message includes changing a certain system state. The exclusive accessing of the system resource is released responsive to the set's lock release node processing the message.

1. Field of the Invention
The present invention concerns managing system state for a system having multiple messages for related transactions in a message flow environment, and more particularly concerns nodes in such an environment for granting and releasing, to a selected one of the messages, exclusive access to a system resource.
2. Related Art
To put business enterprise data to more productive use, the data must be moved reliably among different software applications. That is, businesses want applications located anywhere within their enterprise to be linked together, and even to send messages to systems of other business enterprises, such as those of their customers and suppliers. A simple example is of two payroll systems that need to communicate with each other. Numerous issues arise in this effort, not the least of which concerns communication among disparate applications running on heterogeneous networked platforms using diverse data formats. In the payroll example, for instance, both of the systems may have employee names but with a name stored in one field in one system and in more than one field in the other system. Moreover, the problem illustrated by the payroll example is relatively simple. Data produced by one application may have a data structure that is more unrecognizable to another application. It is of course possible to transform data between applications, but as data is shared among more and more systems the overhead becomes unacceptable, and future maintenance becomes a large and often messy job.
This situation has led to an increasing focus on integration tools, such as IBM's WebSphere MQSeries Integrator ("WMQI"), for developing message processing applications with a common Application Programming Interface (API). ("WebSphere MQSeries Integrator" is a trademark of IBM.) An enterprise integration application developed with software such as WMQI typically acts as a distribution hub, i.e., a sort of a broker, for messages passing among other applications, and may accordingly be referred to herein as a "Broker." In this centralized location, definitions are configured specifying how messages are to be transformed and routed. This arrangement tends to eliminate the need for numerous interfaces between applications and to free developers from worrying about platform differences, such as different operating systems.
This kind of enterprise integration application is typically characterized by graphical tools and a high level flow language for configuring a flow of messages on a structure of interconnected nodes, including numerous predefined nodes, creating what may be referred to as a "workflow" or "message flow" environment. That is, within the Broker, individual functions are assigned to a collection of interconnected nodes, with the processing and transformation activities taking place in the nodes. Through the deployment of predefined and customized nodes, a sophisticated processing environment is built in which nodes perform operations on message data within a message flow, and have the ability to access information outside the message flow, such as information in a database or an external application, and to leave the message flow by placing a message on a queue.
Certain support is typically provided for multithreading in a Broker such as WMQI. A message can be read from a queue to begin the message flow and can be placed into a queue to terminate the flow of the message. There can be multiple flow paths between the input and terminating nodes, with respective messages concurrently flowing through different paths, each message handled by its own thread. Moreover, even if there is only one flow path between the input and terminating nodes, concurrent instances of the same message flow are supported, with each instance processing its own respective message read from the queue.
For such multithreaded messages it is important to maintain system state. For example, two multithreaded transactions, or even two multithreaded messages for the same transaction, may access a common resource, such as a database. The manner in which the threads access the resource may be important for transactional integrity, i.e., for maintaining the system in a proper state. However, in conventional workflow applications processing nodes do not automatically and explicitly maintain transactional integrity of messages flowing through the system. Instead, the developer must carefully maintain transactional integrity within the bounds of the message flow by diligently structuring the Broker application and applying its predefined transactional properties.
One known way to structure a message flow application to maintain transactional integrity among threads is to force related messages to join. See for example, Notani et al., U.S. Pat. No. 6,397,192 B1, "Synchronizing One or More Workflows Using One or More Synchronization-Join Activities That Include Synchronization Logic," May 28, 2002. However this may cause a performance penalty, particularly when this joining includes forcing multiple-threads to become essentially single-threaded. Therefore, a need exists for improvements in a multithreaded message flow environment to manage multiple messages for related transactions.

Method, apparatus and computer program product for managing message flow in a multithreaded, message flow environment

International Business Machines Corporation


A portable water tank heating system utilizes a continuous hollow tubular loop that contains a fluid which is circulated through the tubular loop by convection to prevent the water in a drinking tank from freezing. The system is made up of the continuous loop having an outlet line containing hot fluid under relatively higher pressure and a return line containing cold fluid under relatively lower pressure and a protective housing having hot and cold chambers for holding various components including sensors to maintain the temperature of the fluid above freezing in the system. The fluid in the continuous loop flows from a reservoir and travels past a gas burner in the hot chamber for heating the fluid. As the fluid flows through a heat exchanger in a drinking tank, the fluid releases heat to the cold water in the tank before flowing back into the housing through the return line. The fluid then returns to the reservoir to repeat the operational cycle. The housing has air inlet and exhaust ducts and baffles which allow proper air flow for the burner operation even when the system is subjected to severe inclement weather.

1. Field of the Invention
The present invention relates generally to water tank heating devices. More specifically, the invention relates to a portable water tank heating system which utilizes a continuous tubular loop that is filled with a fluid which is circulated through the tubular loop by convection to prevent the water in a drinking tank from freezing.
2. Description of the Prior Art
In climates where the weather becomes very cold for extended periods of time, the livestock industry encounters many problems and challenges when water in the livestock watering tanks becomes frozen, thereby preventing the livestock from having free access to water. One of the challenges is to provide a water tank heating device with an appropriately protective housing which protects the heater and components of the system even under severe weather conditions. In remote areas, electric power is often not available for powering a water tank heating device. Further, the use of electric power may be impractical or unsafe. Further, the use of solar power in geothermal units is very expensive, and such units are difficult to construct. Many different devices have been developed to deal with the problems and challenges, as exemplified by the following prior art:
U.S. Pat. No. 237,689, issued on Feb. 15, 1881, to Odile Martin, discloses an incubator that uses a gas burner to heat a fluid that circulates by convection and exchanges heat with the incubator-warming chamber to keep the incubator warm. The closed loop fluid heating system disclosed in the incubator of Martin is constructed as an internal part of the device rather than as a portable, external unit like the present invention.
U.S. Pat. No. 1,524,804, issued on May 27, 1924, to Thomas W. Dougherty, discloses a hog watering trough that heats the water circulating in a loop which is open to the trough to keep the water in the trough at a proper drinking temperature. The heating system of the watering trough of Dougherty uses an open loop and is internal to the hog waterer unlike the present invention.
U.S. Pat. No. 2,126,657, issued on Oct. 9, 1936, to Leslie T. Petersen, discloses a livestock watering tank which is heated by a gas burner and in which the water is circulating by convection. The watering tank of Petersen has neither the external heating system or the closed-loop fluid heat exchange of the present invention.
U.S. Pat. No. 2,612,138, issued on Jul. 5, 1950, to Reinhard C. Lindemann, discloses an animal watering fountain which prevents the water in a livestock watering trough from freezing. The fountain of Lindemann has neither the external heating system nor the closed-loop heating of the present invention.
U.S. Pat. No. 3,306,263 issued on Apr. 22, 1965, to Glen J. Johnson, discloses a livestock watering system which prevents the water in the trough from freezing by circulating the water in the tank with the water from a tank located underground below the frost line. The watering system of Johnson has neither the gas-powered heating system nor the closed-loop heating of the present invention.
U.S. Pat. No. 3,618,569, issued on Nov. 9, 1971, to Stephen C. Baer, discloses a device for preventing the water in a livestock watering hole from freezing which consists of a continuous loop tubing filled with a liquid which will circulate through the loop by convection and exchange heat absorbed from the bottom of the watering hole with the water on the surface of the watering hole to prevent it from freezing. The Baer device utilizes a closed loop and is portable. The device is completely submerged, however, making it difficult to use, and it relies on natural differences in temperature to cause convection rather than a gas burner which allows more heat to be exchanged into the water.
U.S. Pat. No. 4,280,556, issued on Jul. 28, 1981, to George H. Cooper, discloses a heat exchange tank assembly for a hot water heating system which utilizes a heated liquid circulating through a closed loop by convection to warm the water in a hot water tank. The closed loop heating system of the hot water heating system of Cooper relies on solar radiation rather than gas heat which does not have the limitations of solar energy.
U.S. Pat. No. 4,320,720, issued Mar. 23, 1982, to Clifford P. Streed, discloses a livestock watering system which uses geothermal energy to heat a fluid in a closed loop. The fluid is evaporated by the geothermal heat and rises through the hot half of the loop and condenses next to the waterer to transfer heat to the waterer and keep the water heated. The waterer of Streed does not disclose the external heating system according to the present invention.
U.S. Pat. No. 5,138,980, issued on Aug. 18, 1992, to Frederick D. Ewing, discloses an animal liquid feeder system which uses an electrically-operated fluid heating and cooling system to circulate a fluid in a closed loop to regulate the temperature of the liquid animal feed in the system. The closed loop temperature regulating system of the Ewing liquid feeder is electrically operated rather than gas-operated which limits the locations in which it can be used.
French Patent Document Number 2,258,124, dated Aug. 18, 1975, by Philippe Pierre Marie et al., discloses an electrically-heated livestock watering tank. Marie does not show the closed loop liquid heating system nor the gas burner of the present invention.
French Patent Document Number 2,469,116, dated May 5, 1981, by Roger Naulet, discloses a float device for preventing freezing of a livestock watering tank The device is electrically operated, unlike the present invention.
Soviet Patent Document Number 1,672,004, dated Oct. 3, 1985, by N. V. Bogomolou et al., discloses a device which uses an electrically heated fluid circulated in a closed loop which extends into a tank for heating the liquid therein. The reference does not have the gas power heating device of the present invention.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed.


A fuel cell system having a hydrogen supply manifold is provided and includes a stack that uses supplied air and fuel gas to generate electricity. A recirculation line recirculates a fuel gas, to an inlet of the stack. An ejector unit is disposed on the recirculation line, supplies fresh fuel gas, and circulates the recirculated gas. The ejector unit includes a middle pressure manifold in which a nozzle mounting portion is formed and a supply passage to transmit fuel gas to the nozzle mounting portion. A control valve is disposed on the middle pressure manifold to adjust fuel supplied to the stack. A nozzle is engaged with an end portion of the nozzle mounting portion to inject fuel gas supplied through the supply passage. Additionally, a low pressure manifold is engaged with the middle pressure manifold to suction and mix exhaust gas of the stack.

(a) Field of the Invention
The present invention is related to a fuel cell system having a hydrogen supply manifold that securely supplies a stack with fuel gas and moisture, the stack generates uses the fuel gas and moisture to generate electrical energy, wherein a pressure of hydrogen is decreased to be recirculated and the compact packaging of the recirculation structure is realized.
(b) Description of the Related Art
As known in the related art, a fuel cell vehicle having a fuel cell system supplies a fuel cell stack with hydrogen as fuel so as to generate electricity, and the electricity that is generated by the fuel cell stack operates a motor so as to move a vehicle.
Herein, a fuel cell system does not transform chemical energy of fuel to combustion heat and is a electricity generation system that transforms chemical energy of fuel to electrical energy through electrochemical process.
The fuel cell system supplies a fuel electrode (anode) of a fuel cell with high purity of hydrogen from a hydrogen storage tank and uses an air supply device such as an air blower to supply an air electrode (cathode) of a fuel cell with atmosphere air.
Thus, the hydrogen that is supplied to a fuel cell stack is divided into a proton and an electron, the divided hydrogen ion is supplied to an air electrode (cathode) through a high molecule electrolyte film, oxygen that is supplied to an air electrode combines with an electron that comes in an air electrode to form moisture, and then the electrical energy is generated therein.
Generally, a fuel cell vehicle uses electricity that is generated by reacting hydrogen and oxygen in a stack so as to operate a motor such that a vehicle can be moved. For this purpose, it is necessary to supply a stack with a predetermined pressure of hydrogen.
Also, it is necessary to large amount of hydrogen so as to increase a flying distance of a fuel cell vehicle, and therefore a fuel cell vehicle uses a high pressure hydrogen tank having hundreds of pressure in a fuel cell vehicle.
Accordingly, a plurality of valves and regulators are disposed to decrease pressure of hydrogen between a hydrogen tank and a stack, and a plurality of pipes and manifolds are used to connect them respectively.
However, the more the portions connecting parts, the higher the possibility of hydrogen leak, and also O ring and sealing members are necessary so as to keep air-tightness, the cost is increased, and the productivity is deteriorated.
Also, because points that is to be measure a leak after the manufacturing and maintenance of the system is increased, air-tightness test time and cost are increased. In addition, when a fitting and tubing is used to configure a gas supply line, connecting portions are increased, and it is hard to use an automatic device to assemble them and to manage an assembly torque. Accordingly, fuel cell vehicle has been making makes an effort to decrease connecting portions/volume of a hydrogen supply system (fuel processing system) having a valve and a regulator.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Fuel cell system using hydrogen supply manifold


A semiconductor storage device comprises: a sense amplifier circuit; a first data retaining circuit and a second data retaining circuit configured to retain data and threshold voltage information, the second data retaining circuit output the data and the threshold voltage information to the outside; and a control circuit configured to control operation. The sense amplifier circuit is configured to perform a data-read operation and a threshold-voltage-information read operation at the same time. The control circuit is configured to control read operations so that either one of the data or the threshold voltage information for which a read operation is finished earlier is output from the second data retaining circuit, and the other one of the data or the threshold voltage information for which a read operation is not finished yet is read from a memory cell array and retained in the first data retaining circuit.

1. Field of the Invention
The present invention relates to a semiconductor storage device, and in particular, to a non-volatile semiconductor storage device allowing multiple bits to be stored in one memory cell.
2. Description of the Related Art
NAND-type flash memory is known as one of non-volatile semiconductor storage devices. The NAND-type flash memory has a memory cell array including a plurality of NAND cell units. Each NAND cell unit includes a plurality of memory cells connected in series and two selection transistors connected to both ends thereof.
Each memory cell stores, in an erase state, data "1" having a negative threshold voltage. In a data write operation, electrons are injected into a floating gate to write data "0" having a positive threshold voltage. The NAND-type flash memory may change the threshold voltage only from a lower value to a higher value in a data write operation, and may change the threshold voltage in the reverse direction (from a higher value to a lower value) only by an erase operation on a block basis.
To increase memory capacity, current technology has developed so-called multi-value NAND-type flash memory to store two or more bits of information in one memory cell. For example, when 3 bits are stored in one memory cell, one memory cell involves 23=8 different threshold voltage distributions. If 8-value information is stored in one memory cell, the interval between eight different threshold voltage distributions will be reduced. Thus, incorrect data read will occur in a data-read operation, which may lead to lower data reliability.
This requires an error check and correct (ECC) operation to be performed for correcting any incorrectly read data. The error check and correct operation may control the number of write pulses to be applied by performing a verify operation when writing data to a memory cell (see Japanese Patent Laid-Open No. 2006-12367), or correct data that has been read from a memory cell when reading data.
For a semiconductor storage device where an error check and correct operation is performed in reading data, improved data reliability may be achieved by reading data to be read as well as the threshold voltage information of the relevant memory cell, and adding that information to the read data. As used herein, the term "threshold voltage information" refers to information that indicates where the threshold voltage of a memory cell is positioned in the threshold voltage distribution to which certain data is allocated. Given that operations are separately performed for reading data and threshold voltage information, the read data that has been read by a sense amplifier and retained in a data register is transferred to the outside before the threshold voltage information is read. Since the NAND-type flash memory outputs a large amount of data, there will be some period of time during which threshold voltage information is not read at the time of transferring read data, which could increase the total operating time for reading data and threshold voltage information.

Semiconductor storage device equipped with a sense amplifier for reading data and threshold-voltage-information data


A device for removing secretions from an artificial tube is provided. The device may include a clearing catheter and a driving mechanism that may apply repetitive motion to the clearing catheter. In another version of the device, the clearing catheter may dispense irrigation fluid and aspirate the irrigation fluid. The clearing catheter may have an irrigation and an aspiration lumen that may both reciprocate with the clearing catheter. In another version a compliant member into which irrigation fluid is located may be present.

1. Field of the Invention
The present invention pertains generally to the field of medical devices, and more specifically to a system for in-situ clearing of secretions in endotracheal tubes and other tubes in the body where secretions or other materials accumulate and negatively impact tube patency.
2. Background
The following is a description of the background of endotracheal tubes (ETTs). It should be understood that the device and method of the present invention is not limited to the clearing of ETTs but is applicable to a range of artificial tubes such as indwelling catheters, pigtail catheters, abscess drains, and chest tubes and that ETTs are being discussed simply by way of example. It should also be understood that the device and method of the present invention is not limited to secretions but is applicable to a range of accumulating and/or occluding materials such as blood, clots, and ingrown tissues/membranes.
Automated mechanical ventilation is often required for patients under anesthesia and for longer-term breathing assistance in compromised patients. Endotracheal tubes are placed in the upper respiratory tract of patients to provide direct airway access when connected to a mechanical ventilator. Annually, 50 million ETTs are sold globally. Patients intubated with ETTs are unable to effectively clear lung secretions, and therefore secretions can accumulate and partially occlude the inside of the ETT. This leads to increased airway resistance and a potentially negative impact on patient health if not remedied. Without proper air humidification, the secretions also potentially become dried, thick, and difficult to remove.
The most routine method to maintain ETT patency is periodic aspiration with a suction catheter. The suction catheter is designed to be momentarily inserted down the ETT manually while attached to a negative pressure source. There are two general types of suction catheters: open and closed. An open suction catheter requires the patient to be disconnected from the ventilator for the suctioning procedure. A closed suction catheter is enclosed in a sterility sleeve and remains attached to the ventilator circuit the entire time. Suctioning can occur without having to shut off the ventilator or disconnect the patient. Whether open or closed, the general suction procedure remains the same. With one hand stabilizing the proximal end of the ETT, the suction catheter is fed into the ETT with the opposite hand until the end is reached, being careful to not over-insert the catheter beyond the tip of the ETT. While retracting the suction catheter, the negative pressure is applied to suction out secretions accumulated on the inner wall of the ETT. It is generally desired for the entire suction procedure to be performed in 10-15 seconds, or ≦5 seconds in children to minimize the impact of the suctioning procedure on lung mechanics and respiration. Generally, a patient will require suctioning every 4-6 hours, but the process may be performed with greater regularity if necessary. The procedure is recommended on an as needed basis, not a regular interval, due to the detrimental effect on the patient.
Attempts to clear the ETT using standard techniques are often ineffective, time-consuming, expensive, and an agonizing experience for the patients, families, and health care providers. Standard methods can also dislodge bacteria-containing particles into the lungs. Ventilator Acquired Pneumonia (VAP) is a major source of infection in hospitals, and is often due to the direct path to the lungs for bacteria from ETT intubation. Standard suctioning has an effect on lung mechanics, including decreased expired tidal volume and lung compliance. Clinical side effects include hypoxia (low oxygen in blood), bradycardia (low heart rate), or atelectasis (collapse of part of the lung). In general, the long term effects of acute changes in lung mechanics or cumulative exposures to short term clinical side effects of suctioning on long term respiratory health is not known. Minimizing the potential negative impacts of the suctioning process on the lungs is desirable.
Negative effects can be minimized with use of smaller diameter suction catheters, which allow improved airflow during suctioning. With narrow ETTs (such as neonatal or pediatric patients) this is difficult to achieve without severely limiting secretion aspiration effectiveness using standard methods. Such small diameter suction catheters may easily clog, depending on the consistency of the secretions. In addition to airflow considerations, larger suction catheters may be difficult to insert if the catheter diameter to ETT inner diameter ratio is larger than 0.7.
Occasionally, physiologic saline is first instilled at the inlet to the ETT in an attempt to hydrate and thin the secretions to encourage its removal during the subsequent suctioning procedure, although this point remains controversial. Additional goals of saline instillation may include lubricating and easing the insertion of the catheter itself, and/or elicitation of a cough from the patient to aid secretion removal. The current methods of instilling saline into ETTs are not precise and there is risk of excess fluid entering the lungs and possibly causing dispersion of adherent contaminating material. Reports further suggest saline instillation may cause greater blood oxygen desaturation than suctioning without saline. Despite lack of evidence supporting saline instillation and its potential risks, many clinicians continue the practice.
When suctioning is unable to restore patency quickly, the only recourse is to replace the ETT, further raising the risk of VAP while also depriving the patient of oxygen until the patient is reintubated and reconnected to the ventilator. The present active device will safely and quickly clear ETTs, while reducing the negative impact the suction procedure has on the lung mechanics of an already compromised patient.
The present device is also applicable to clearing other types of tubes that may become occluded by secretions or other accumulating or occluding material. For example, pigtail catheters for chest drainage may be cleared in the same way.

Active system for in-situ clearing of secretions and occlusions in tubes


A measuring device having an elongated member with at least one measuring edge and a measuring indicia including successive groups of equally spaced color coded measuring marks located adjacent to and extending along the length of the measuring edge. Each successive group is identified by a different label. Each individual measuring mark corresponds to a selected fractional portion of the group wherein it is located and has a color which is different from all of the remaining measuring marks in the group and is the same color as the measuring marks in each successive group which correspond to the corresponding fractional portion in each successive group.

1. Field of the Invention
This invention relates generally to measuring devices, and more particularly, to measuring devices having color coded indicia thereon to facilitate the measurement of fractional lengths with a minimum of errors and loss of time.
2. Description of the Prior Art
It has been observed that the measurement of fractional lengths is particularly difficult to a significant number of people. Furthermore, it is difficult to differentiate between and to locate gradations along a tape or a ruler without tediously counting the individual gradations. Many devices have been proposed to help with the measurement of different lengths. An example of such a device is disclosed in U.S. Pat. No. 1,816,548, which assists with fractional measurement. Other devices which have been proposed to solve the aforementioned problem through the use of color combinations are disclosed in U.S. Pat. Nos. 2,561,020, 4,323,234 and 5,335,421. However, none of these devices permits the easy, accurate and convenient measure of fractional lengths without counting the individual gradations.
It is the object of the invention to provide a measuring device which assists in the measurement of fractional lengths. It is a further object of the invention to provide a device which is easy to use, inexpensive and simple in construction.

Graduated measuring device with color coded indicia


An improved cermet for hermetically sealing a discharge vessel in a ceramic discharge lamp where the cermet includes a material having a coefficient of linear expansion which is at least equal to a coefficient of linear expansion of a translucent ceramic, and a material having a coefficient of linear expansion which is smaller than the coefficient of linear expansion of the translucent ceramic, where the cermet has an average coefficient of linear expansion in a range of Exc2x11.0xc3x9710xe2x88x926 (Kxe2x88x921) at a temperature range of 25 to 300xc2x0 C., where E (Kxe2x88x921) is an average coefficient of linear expansion of said translucent ceramic at a temperature range of 25 to 300xc2x0 C. In addition, a ceramic discharge lamp utilizing such a cermet.

1. Field of the Invention
The invention relates to a cermet for a lamp which is used for hermetically sealing a discharge vessel in a ceramic discharge lamp, and also to a ceramic discharge lamp. The invention relates especially to a cermet for a lamp with a coefficient of linear expansion which is essentially equal to the coefficient of linear expansion of a translucent ceramic which forms the discharge vessel, and to a discharge vessel of ceramic with hermetically sealed components such a cermet for a lamp.
2. Description of the Related Art
Conventionally a ceramic discharge lamp which is shown in FIG. 1 (for example patent publication JP-SHO 61-220265) is known which has a discharge vessel 3 of translucent ceramic, with an arc tube part 1 and side tube parts 2 which are joined to the arc tube part 1. In the arc tube part 1, there are a pair of electrodes 4 opposite one another. The electrodes 4 are located in 5 the tip areas of the upholding parts 5 of the electrodes. The base parts of the upholding parts of the electrodes are inserted into hermetically sealed components 6. A hermetically sealed arrangement is obtained by fritting-welding of these hermetically sealed components 6 in the side tube parts 2. In FIG. 1, reference number 7 labels an outer lead which is inserted into the hermetically sealed component 6.
The hermetically sealed component 6 in this discharge lamp consists of a conductive cermet which is obtained by sintering of ceramic powder and metal powder and is hermetically welded by a glass frit (not shown in the drawing) in the side tube part 2.
The ceramic for obtaining this cermet is the same material as the translucent ceramic comprising the discharge vessel 3, for example polycrystalline aluminum oxide, so that the difference between the coefficient of linear expansion of the hermetically sealed component 6 of this cermet and the coefficient of linear expansion of the discharge vessel 3 is reduced.
Molybdenum or tungsten is used as the metal powder to obtain the cermet. To ensure the conductivity necessary for supply, a metal with a percentage by volume from 30 to 60% is contained therein.
Metals such as molybdenum and tungsten which are contained in the cermet have a smaller coefficient of linear expansion than a ceramic like aluminum oxide. The coefficient of linear expansion of the cermet which comprises the hermetically sealed component 6 is therefore, less than the coefficient of linear expansion of the ceramic which comprises the cermet. As a result, between the coefficient of linear expansion of the cermet to be obtained and the coefficient of linear expansion of the translucent ceramic comprising the discharge vessel 3, a difference of greater than 1xc3x9710xe2x88x926 (Kxe2x88x921) results, even when the same material as that of the translucent ceramic comprising the discharge vessel 3 is used as the ceramic for the cermet.
As a result, the following disadvantages arose when the hermetically sealed components are formed for example from a conventionally known conductive cermet (especially based on aluminum oxide-molybdenum) and from fritting-welding these hermetically sealed components on the discharge vessel of translucent aluminum oxide ceramic.
In welding (cooling process) or at the start of operation (within a few hundred hours), there are cases in which due to the different coefficients of linear expansion of the two material components, cracks form at the welded sites. Reliability is therefore low.
The first object of the invention is to devise a cermet for a lamp in which the reliability of the hermetically sealed parts is increased by the fact that their coefficient of linear expansion is made essentially equal to the coefficient of linear expansion of a translucent ceramic which comprises the discharge vessel of a discharge lamp of ceramic.
A second object of the invention is to devise a cermet for a lamp in which no cracks form at the weld spots, even if it is frit-welded as the hermetically sealed components of a discharge lamp of ceramic in the side tube parts of the discharge vessel.
The third object of the invention is to devise a ceramic discharge lamp in which no cracks occur at the locations at which side tube parts of the discharge vessel and the hermetically sealed components are frit-welded to one another.
The objects are achieved by a cermet in accordance with the embodiments of the present invention where.
(1) In a cermet for a lamp which is used for hermetically sealing a discharge vessel (10) in a ceramic discharge lamp, the object is achieved in that the cermet contains a material with a coefficient of linear expansion which is greater than or equal to that of a translucent ceramic comprising the discharge vessel (10) of the above described ceramic discharge lamp. Furthermore, the cermet contains a material with a coefficient of linear expansion which is smaller than that of the translucent ceramic, and that the average coefficient of linear expansion at 25 to 300xc2x0 C. is in the range of Exc2x11.0xc3x9710xe2x88x926 (Kxe2x88x921) where E (Kxe2x88x921) the average coefficient of linear expansion of the translucent ceramic comprising the discharge vessel (10) of the above described ceramic discharge lamp at 25 to 300xc2x0 C.
(2) In a cermet for a lamp which is used for hermetically sealing a discharge vessel (10) in a ceramic discharge lamp, the cermet is obtained by sintering with one another a ceramic with a coefficient of linear expansion greater than that of a translucent ceramic comprising the discharge vessel (10) of the above described ceramic discharge vessel, and a metal with a coefficient of linear expansion less than that of the translucent ceramic.
(3) In a cermet for a lamp which is used for hermetically sealing a discharge vessel (10) in a ceramic discharge lamp, the object is achieved in that the cermet is obtained by sintering with one another a ceramic, a metal with a coefficient of linear expansion which is less than that of a translucent ceramic comprising the discharge vessel (10) of the above described ceramic discharge lamp, and a material with a coefficient of linear expansion greater than that of the translucent ceramic.
In this cermet for a lamp it is desirable for the average coefficient of linear expansion of the ceramic which forms the cermet at 25 to 300xc2x0 C. to be in the range of Exc2x11.0xc3x9710xe2x88x926 (Kxe2x88x921) where E (Kxe2x88x921) the average coefficient of linear expansion of the translucent ceramic comprising the discharge vessel (10) of the above described ceramic discharge lamp at 25 to 300xc2x0 C. It is especially preferred that the ceramic which forms the cermet comprises of the same material as the translucent ceramic comprising the discharge vessel (10) of the above described ceramic discharge lamp.
Furthermore the objects in the ceramic discharge lamp in accordance with the embodiments of the present invention achieved as follows:
(4) In a ceramic discharge lamp including a discharge vessel (10) of translucent ceramic with an arc tube part (11) and side tube parts (12) which are connected to the arc tube part (11), further including a pair of electrodes (21) opposite one another in the arc tube part (11) and in which a hermetically sealed arrangement is obtained by fritting-welding of these hermetically sealed components (24) on the side tube parts (12). The base parts of the upholding parts (22) of the electrodes are inserted, into the hermetically sealed arrangement the upholding parts having trip areas which are provided with electrodes (21) the object is achieved as claimed in the invention in that the above described hermetically sealed components (24) consist of the above described cermet for a lamp.
(5) In a ceramic discharge lamp including a discharge vessel (10) of translucent ceramic with an arc tube part (11) and side tube parts (12) that are connected to the arc tube part (11), further including a pair of electrodes (21) opposite one another in the arc tube part (11) and in which a hermetically sealed arrangement is obtained by fitting-welding of cylindrical or disk-shaped hermetically sealed components (24) on the outside faces of the side tube parts (12). The base parts of the upholding parts (22) of the electrodes are inserted into the hermetically sealed arrangement the upholding parts having tip areas which are provided with electrodes (21) the object is achieved as claimed in the invention in that where the above described hermetically sealed components (24) consist of the above described cermet for a lamp.

Cermet for lamp and ceramic discharge lamp


A racetrack-shaped magnetic-field-generating apparatus for magnetron sputtering comprising a linear portion and corner portions, the linear portion comprising a magnetic base, a center permanent magnet disposed on its surface, and side permanent magnets disposed on both sides thereof with a gap; the center and side permanent magnets being vertically magnetized with opposite polarities; the corner portions comprising a non-magnetic base, a center magnetic pole member disposed on its surface, a semicircular or semi-polygonal, peripheral magnetic pole member, and plural permanent magnets arranged between both magnetic pole members with their magnetization directions in parallel to a target surface; and the magnetic poles of plural permanent magnets opposing the center magnetic pole member having the same polarity as those of the center permanent magnet opposing the target.

In the production process of electronic parts such as semiconductor ICs, etc., magnetron sputtering methods having high film-forming speeds by targets and capable of forming thin films at low temperatures because electrons are not impinged onto substrates are widely used to form thin films on substrates.
A phenomenon that atoms or molecules are ejected from a target by a high-speed bombardment of an inert substance such as Ar, etc. is called "sputtering." The ejected atoms or molecules can be accumulated on a substrate to form a thin film. A magnetron sputtering method uses a magnetic field in a cathode to increase a film-forming speed, thereby improving the productivity.
A magnetron sputtering apparatus comprises a substrate (anode), a target (cathode) arranged to oppose the substrate, and a magnetic-field-generating apparatus arranged below the target, in a vacuum chamber. With voltage applied between the anode and the cathode to cause glow discharge for ionizing an inert gas (Ar at about 0.1 Pa, etc.) in the vacuum chamber, secondary electrons discharged from the target are captured by a magnetic field generated by the magnetic-field-generating apparatus, so that cyclotron motion occurs on a target surface. Because the cyclotron motion of electrons accelerates the ionization of gas molecules, a film-forming speed is dramatically higher than when a magnetic field is not used, resulting in strong adhesion of a film.
As shown in FIG. 29, a magnetic circuit apparatus 4 used in a magnetron sputtering apparatus comprises a center rod-shaped magnet 410 magnetized in a height direction (perpendicular to a target surface), a peripheral rectangular magnet 420 arranged around the center magnet 410 and magnetized in an opposite direction to the center magnet 410, and a yoke 430 supporting the center magnet 410 and the peripheral magnet 420, to generate a leaked magnetic field in a racetrack form in parallel to a target surface (for example, see JP 8-134640 A). With a racetrack-shaped magnetic circuit, secondary electrons can be contained in a closed space, resulting in a high secondary electron density and thus high sputtering efficiency. To form this closed space, a magnetic field of 10 mT or more in a horizontal component of a magnetic flux density is usually needed.
The erosion of a target is fastest in a portion shown by a broken line in FIG. 30, in which a perpendicular component of a magnetic flux density is zero, and by adjusting a magnetic field to cause uniform erosion in this portion, a target can be used for a long period. However, when plasma is contained on a target surface by a magnetic circuit apparatus 4 as shown in FIG. 29, plasma formed in the linear portion is concentrated in the corner portions, resulting in rapid erosion in the corner portions. The concentration of plasma occurs by a magnetic flux concentrated in the corner portions, because a portion in which a perpendicular component of a magnetic flux density is zero is located at a distance R from the center magnet 410 in the linear portion, and at a smaller distance r (r<R) in the corner portions.
JP 8-134640 A discloses a technology of arranging magnets having a smaller residual magnetic flux density in a T form in corner portions, to eliminate the unevenness of a perpendicular component of a magnetic flux density in the corner portions. However, its improvement is not sufficient, making it desirable to develop a technology of alleviating the concentration of a magnetic flux in the corner portions.
JP 2008-156735 A discloses, as shown in FIGS. 31(a) and 31(b), a magnetic-field-generating apparatus 5 for magnetron sputtering, which comprises a non-magnetic base 510, a rectangular center magnetic pole piece 520 disposed on a surface of the non-magnetic base 510, a peripheral racetrack-shaped magnetic pole piece 530 disposed around the rectangular center magnetic pole piece 520, and plural permanent magnets 540, 550 arranged between the center magnetic pole piece and the peripheral magnetic pole piece, the permanent magnets 540, 550 being magnetized in a horizontal direction (in parallel to a target surface) and arranged with their magnetic poles of the same polarity opposing the center magnetic pole piece, and the center magnetic pole piece and the peripheral magnetic pole piece being higher than the permanent magnets. JP 2008-156735 A describes that because magnetic pole surfaces of the permanent magnets are in contact with the magnetic pole pieces in this magnetic-field-generating apparatus, the leakage of magnetic flux from the permanent magnets is reduced, so that a predetermined magnetic flux can be generated by a smaller number of permanent magnets than in the above magnetic circuit apparatus comprising magnets magnetized in a height direction. JP 2008-156735 A further describes that a region providing a magnetic field intensity of 10 mT or more in a horizontal component of a magnetic flux density, which is necessary for containing an inert gas excited to a plasma state, is expanded than before, thereby expanding an erosion region of a target, providing uniform erosion between the linear portion and the corner portions, thereby forming a uniform-thickness film on a substrate.
However, because the magnetic-field-generating apparatus described in JP 2008-156735 A comprises a non-magnetic base, a magnetic field leaks on the opposite side of the target in the magnetic circuit, adversely affecting control equipments for the sputtering apparatus disposed on the opposite side of the target. When large magnetic field leakage occurs on the opposite side of the target, electronic devices cannot disadvantageously be arranged on a rear side of the magnetic circuit. Though a magnetic circuit base may be formed by a magnetic material such as iron to prevent magnetic field leakage, only a small amount of a magnetic field appears on the target side because most magnetic fields generated pass through the magnetic base. Further, because most part of the linear portion is occupied by magnets in the magnetic-field-generating apparatus described in JP 2008-156735 A, fastening members such as screws are not easily arranged there, making it difficult to fix it to a sputtering apparatus.
Thus desired is the development of an efficient magnetic-field-generating apparatus for magnetron sputtering, which has the reduced influence of a leaked magnetic field on a sputtering apparatus, is easily fixed to a sputtering apparatus, and provides the uniform erosion of a target.
As a technology of expanding an erosion region to provide a proper perpendicular component distribution of a magnetic field on a target surface in the use of a magnetic circuit apparatus 4 as shown in FIG. 29, JP 2006-16634 A discloses a magnetic-field-generating apparatus comprising magnetic plates (shunt plates) arranged in parallel to a target surface between the magnetic pole of the center magnet and the magnetic pole of the peripheral magnet. JP 2006-16634 A describes that the shunt plates contribute to the formation of a region in which a perpendicular component of a magnetic field generated by the magnetic circuit on a target surface is zero or flat near zero, or a region crossing the zero point three times.
However, because the magnetic-field-generating apparatus described in JP 2006-16634 A has a structure in which shunt plates are arranged between the magnetic circuit and the target, the removal and position adjustment of the shunt plates for adjusting a magnetic field cannot easily be conducted. Also, because vacuum should be released when a target-containing chamber is in a vacuum state, for example, a demand for adjusting a magnetic field depending on the erosion of a target during sputtering cannot be met.
In electronic parts constituted by multilayer thin films such as semiconductor ICs, etc., various metal films and alloy films are necessary, needing different targets for various layers. In a sputtering apparatus for producing such electronic parts, sputtering should be conducted with different targets for various layers under conditions suitable for them. Because magnetic field intensity is one of factors having large influence on production efficiency and the properties of metal films among sputtering conditions, there is a demand for properly adjusting magnetic field intensity for each of layers formed with different targets. Though the adjustment of magnetic field intensity is possible to some extent by changing the distance between the magnetic-field-generating apparatus and the target, it is extremely difficult to change a magnetic field finely depending on the position of the target. Thus, the development of a magnetic-field-adjusting means for an optimum magnetic circuit is desired.

Magnetic-field-generating apparatus for magnetron sputtering


A method for producing a polarizing plate including a polarizer and a substrate film is provided. The method comprises: stretching a primary film to obtain a polarizer material film; providing an unstretched substrate film on the polarizer material film to obtain a layered body; and stretching the layered body to obtain the polarizing plate. The polarizer includes a dichroic material and has a thickness T of 20 μm or less. A phase difference Re in an in-plane direction of the substrate film in the polarizing plate is 20 nm or less.

As a display device such as a liquid crystal display device and an organic electroluminescent (EL) display device, a display device having a large surface area, light weight and thin thickness has been required in prior art. Therefore, as a panel constituting the display device, a thin panel has been required in prior art.
In a display device, a polarizing plate including a polarizer and a protective film for protecting the polarizer is generally used. In order to constitute a thin display device, a thinner polarizing plate is also required. In particular, materials generally used for a polarizer, such as polyvinyl alcohol, may shrink in a use environment of a display device. Such shrinkage may cause a problem of warping when the display device has a large surface area and thin thickness. Therefore, employment of a polarizer having a thickness as thin as 10 μm or less is expected to contribute to thickness reduction of the display device attributed to the thin thickness of the polarizer itself, and also contribute to reduction of the aforementioned occurrence of the warping.
However, when such a thin polarizer is produced from polyvinyl alcohol by a prior art production method, melt-breakage of the polarizer frequently occurs. As methods for producing a polarizing plate including a thin polarizer with which such melt-breakage of the polarizer can be avoided, some methods have been proposed. For example, Patent Literature 1 proposes a method in which a layered body is obtained by attaching an unstretched polyvinyl alcohol-based film to an unstretched high-density polyethylene substrate film, the layered body is then subjected to a stretching treatment, and the substrate film is separated therefrom to obtain a polyvinyl alcohol-based film.
Patent Literature 2 proposes a method in which an aqueous solution containing a polyvinyl alcohol-based resin is applied onto an amorphous ester-based thermoplastic resin substrate to form a polyvinyl alcohol-based resin layer and obtain a layered body, the layered body is then subjected to a stretching treatment, a dichroic material is oriented to obtain a colored layered body, and the colored layered body is subjected to a stretching treatment to obtain an optical film.


The disclosed computer-implemented method for establishing restricted interfaces for database applications may include analyzing, by a computing device, query behavior of an application for query requests from the application to a remote database in a computer system and identifying, based on the analysis, an expected query behavior for the application. The method may include establishing, between the application and the remote database, a restricted interface. The method may include receiving, at the restricted interface, a query request from the application to the remote database and limiting, by the restricted interface, the query request from the application to the remote database based on the expected query behavior. The method may include determining, by checking the query request against the expected query behavior, that the query request is anomalous query behavior and performing a security action with respect to the computer system. Various other methods, systems, and computer-readable media are also disclosed.

Many applications and services are available over the internet. These applications may be accessed by a user's computer accessing the internet, or a user's mobile device. These applications often require storing and accessing data. For example, the user may have a user account associated with the application or service. The user's user account data may be stored remotely such that the user may access the user account data from multiple devices. Often, the user account data may be stored in a remote database that is accessed by the application. Storing the user account data in the remote database may further protect the user account data, which may include personal data, payment information, etc. The application may have limited access to the remote database as a security measure.
However, an attacker may attempt to breach the security of the remote database by compromising the application. Because the application has access to the database, an attacker may be able to bypass some of the security measures by accessing the database through the application. For example, the attacker may pretend to be the application and send queries to the database. The database, believing the queries to be valid queries from the application, may accordingly respond, which may expose protected data.
The instant disclosure, therefore, identifies and addresses a need for systems and methods for establishing restricted interfaces for database applications.

Systems and methods for establishing restricted interfaces for database applications


A management device includes a memory and a processor configured to transmit a first instruction to proxy servers, receive, from each of the proxy servers, each of a plurality of expected completion times for each transaction executed by each of the proxy servers, perform a selection of a first proxy server corresponding to an earliest expected completion time among the plurality of expected completion times, and transmit a second instruction to the first proxy server so that the first proxy server executes scale-in processing when the transaction executed by the first proxy server ends.

In a business system using a database (hereinafter also referred to as an information processing system), for example, a business operator which provides a service to a user (hereinafter, also simply referred to as a business operator) constructs a business system including a database storing data used for provision of the service.
The above-described business system includes, for example, a plurality of databases storing respective pieces of data synchronized with each other and a database-connected proxy server (hereinafter, also simply referred to as a proxy server) which distributes a query transmitted from an application to any one of the databases. In this case, the proxy server analyzes the content of a query accepted from an application and identifies a database to handle the query based on a result of the analysis. The proxy server distributes the query transmitted from the application to the identified database. This allows the business operator to perform database load balancing.
For example, Japanese Laid-open Patent Publication No. 2002-163241, Japanese Laid-open Patent Publication No. 2003-248668, Japanese National Publication of International Patent Application No. 2013-544562, and Japanese Laid-open Patent Publication No. 2007-226802 disclose related art.

Management device for controlling scale-in processing, computer-readable recording medium storing management program for controlling scale-in processing and management method for controlling scale-in processing


A linear motion rolling contact guide unit includes a rail elongated in shape, a slider slidably mounted on the rail and a plurality of rolling members interposed between the rail and the slider. The rail has a top surface, a pair of side surfaces and a bottom surface, and a guide groove is formed in each of the side surfaces with a tapered relief trench formed at the bottom of the guide groove. A side recess is also formed in each of the side surfaces. The slider is provided with an end seal having a first seal lip at each of front and rear ends and also with a bottom seal having a second seal lip. The first seal lip is in sliding contact with the top surface and also with the guide groove and the tapered relief trench and the second seal lip is in sliding contact with the side recess of the rail.

1. Field of the Invention
This invention generally relates to a linear motion rolling contact guide unit, and, in particular, to such a linear motion rolling contact guide unit having an enhanced seal characteristic.
2. Description of the Prior Art
A linear motion guide unit is well known in the art, and it generally includes a rail, a slider and a plurality of rolling members interposed between the rail and the slider for providing a rolling contact between the rail and the slider. There are basically two types of such a linear motion guide unit, i.e., the infinite stroke type and the finite stroke type. Such a typical prior art linear motion guide unit is illustrated in FIG. 7. As shown, the illustrated linear motion guide unit includes a rail 1a extending straight over a desired length, a slider 3 slidably mounted on the rail 1a in a straddling manner, and a plurality of balls 2 as rolling members interposed between the rail 1a and the slider 3. Use may also be made of rollers as rolling members in place of balls 2.
In the structure shown in FIG. 7, the rail 1a is elongated in shape and has a generally square or rectangular cross section so that it has a pair of opposite side surfaces 4a, each of which is formed with an inner guide groove 5 extending in parallel with the longitudinal axis of the rail 1a. Thus, the structure shown in FIG. 7 provides a two guide channel type linear motion guide unit. Alternatively, as shown in FIG. 8, another inner guide groove may be formed in each of the opposite side surfaces, or at the top thereof, of the rail 1a, in which case a four guide channel type linear motion guide unit is provided.
As shown in FIG. 7, the rail 1a is provided with a plurality of mounting holes 26 through which bolts or the like may be inserted to have the rail 1a fixedly mounted on a desired object. On the other hand, the slider 3 typically has a U-shaped cross section, including a horizontal section and a pair of side sections depending from the opposite sides of the horizontal section, so that the slider 3 is slidably mounted on the rail 1a in a straddling manner. The slider 3 is typically provided with a pair of endless circulating paths, including a load path section, a return path section 11 and a pair of curved connecting path sections connecting the corresponding ends of the load and return path sections as well known in the art. An outer guide groove 1 is formed in a surface of each of the side sections of the slider 3 in an opposed relationship with a corresponding one of the inner guide grooves 5 of the rail to thereby define a load path section as a guide channel between the associated pair of inner and outer guide grooves.
A plurality of rolling members or balls 2 in the illustrated example are provided in each of the endless circulating paths so that the balls 2 in the load path sections provide a rolling contact between the rail 1a and the slider 3 and therefore the slider 3 may move relative to the rail 1a as long as the rail 1a extends.
When the slider 3 is detached from the rail 1a for some reason, such as maintenance or repair, mostly those balls 2 which are located in the load path sections fall off. If this happens, it would be extremely difficult to put all of the balls 2 back in position when the slider 3 is mounted on the rail 1a once again. Thus, in order to prevent the balls from falling off when the slider 3 is removed from the rail 1a, a ball retaining member 18 extending generally along the load path section is provided with its both ends fixedly attached to the slider 3 so as to prevent the balls from falling off when the slider 3 is detached from the rail 1a.
Such a ball retaining member 18 is integral with and thus moves with the slider 3 and thus it must be located not to scrub against the rail 1a when the slider 3 moves relative to the rail 1a. For this reason, a relief trench 6a is provided at the bottom of each of the inner guide grooves 5 extending in parallel with the longitudinal axis of the rail 1a to receive therein a portion of the ball retaining member 18 without contact. In the prior art, such a relief trench 6a is typically either square or rectangular in shape. Incidentally, in the structure shown in FIG. 8, the additional guide groove is not provided with a relief trench; however, as well known in the art, a plate-shaped projection is typically provided on the slider 3 to project therefrom toward the balls 2 to retain the balls 2 in position, though such a projection is not shown specifically.
Now, a typical prior art method for manufacturing the rail 1a will be described with reference to FIGS. 4 through 6.
(a) As shown in FIG. 4, a rail intermediate product 19 having a shape indicated by the two-dotted line is formed from an alloy steel material or the like by drawing. The rail intermediate member 19 includes a top surface 20, a side surface 21 and a bottom surface 24. The side surface 21 is formed with a guide groove portion 22 and a side recess portion 23.
(b) After drawing, a relief trench 6a for receiving therein a corresponding ball retaining member 18 is formed at the bottom of each of inner guide grooves 22 by milling as shown in FIG. 5.
(c) Then, a guide surface of the inner guide groove 22 is hardened by induction hardening.
(d) Then, after removing distortions due to heat treatment, selected portions of the rail intermediate product 19, including a top surface portion 20, a guide groove portion 22, a side surface portion 21 and a bottom surface portion 24, as indicated by the fat lines in FIG. 6, are ground to thereby finish the rail guide groove 5 and side surface 4a to a desired shape and accuracy, as shown by the solid line in FIG. 4.
Additional steps, such as a step for providing the mounting hole 26, are also carried out, but such additional steps are omitted since they do not form a part of the present invention. In FIG. 4, a contact relationship between the finished guide groove 5 and an associated ball 2 is illustrated. It is to be noted that a side recess 7a(23) remains unprocessed after drawing as indicated by the dotted line in FIG. 6.
In accordance with the prior art, the relief trench 6a is formed by milling irrespective of the length of the rail 1a to be manufactured. Thus, if the rail 1a is relatively long, there may be produced a larger deformation after heat treatment so that there arise fluctuations in the position of the relief trench 6a. Thus, after grinding, when the rail 1a and the slider 3 are assembled, there arises a case in which the ball retaining member 18 is in contact with the relief trench 6a of the rail 1a. In order to avoid such an inconvenience, the width of the relief trench 6a must be made significantly larger as compared with the size of the ball retaining member 18. It is disadvantageous to set the width of the relief trench 6a larger since the effective ball bearing portion of the guide groove 5 is reduced and the rigidity of the guide groove 5 is also reduced.
As shown in FIG. 7, the slider 3 is generally comprised of a center block 8 and a pair of front and rear end blocks 9 each fixedly attached to each end of the center block 8. In the structure shown in FIG. 7, since a pair of endless circulating paths including a load path section, a return path section 11 and a pair of curved connecting path sections connecting the corresponding ends of the load and return path sections is provided, the load and return path sections are defined in the center block 8 and the curved connecting path sections are defined in both of the front and rear end blocks 9. It is to be noted, however, that the guide unit shown in FIG. 7 may also be constructed to be of the finite stroke type in which no endless circulating paths are provided. The end blocks 9 are also typically formed with a lubricant distributing system, and a grease nipple 12 is also provided as inserted into the end block 9.
Each of the end blocks 9 is provided with an end seal 13 which projects forwardly or rearwardly and which has a lip 14 defined at its tip end to be in sliding contact with the top surface 15, side surface 4a and guide groove 5 of the rail 1a so as to prevent any undesired foreign matter from entering into a gap between the rail 1a and the slider 3. However, in the prior art structure, the end seal lip 14 is only disposed to be in the vicinity of the relief trench 6a and not in sliding contact therewith. Moreover, a bottom seal 16 is also mounted at the bottom surface of the center block 8 of the slider 3. The bottom seal 16 has a lip 17 defined at its tip end, but the lip 17 is only disposed to be in the vicinity of the side recess 7a and not in sliding contact therewith. In this manner, since the seal lips 14 and 17 are not provided to be in sliding contact with corresponding surface portions of the rail 1a, there are defined open gaps which could allow any undesired foreign matter to enter into the gap between the rail 1a and the slider 3, which is extremely disadvantageous. The reason why the end seal lip 14 cannot be set in sliding contact with the corresponding relief trench 6a is because the relief trench 6a provides a rough surface. This is so because the relief trench 6a has been formed by milling. In addition, because of errors in positional relationship between the guide groove 5 and the relief trench 6a, a sliding contact between the end seal lip. 14 and the surface of the relief trench 6a would fluctuate significantly and thus the seal end lip 14 may be temporarily separated away from the surface of the relief trench 6a during operation. In addition, the seal lip 17 of the bottom seal 16 cannot be brought into sliding contact with the side recess 7a since the side recess 7a is an unprocessed and thus an extremely rough surface.
In addition, since the processing of the relief trench 6a and the processing of the guide groove 5 are carried out separately and before and after heat treatment in the prior art process, an absolute shift in position between the relief trench 6a and the guide groove 5 tends to be amplified, which can also be a cause of a sliding contact between the ball retaining member 18 and the relief trench 6a. Furthermore, since the side recess 7a(23) (FIG. 4) of the rail 1a remains unprocessed after drawing, a bottom surface seal 16 of the slider 3 cannot be brought into sliding contact with the side recess 7a(23), and, thus, the sealing characteristic between the rail 1a and the slider 3 remains incomplete in this respect also.

Linear motion rolling contact guide unit having an enhanced seal characteristic


There is described a method as well as a device for motion detect ion in an optical sensing device, such as an optical mouse. A photodetector array comprising a plurality of pixels is used to detect successive light intensity patterns of an illuminated portion of a surface with respect to which a measurement of relative motion is to be determined. Light intensity between neighbouring pixels is compared in order to determine edge direction data descriptive of light intensity differences between the pixels, such data including (i) a first edge condition, or positive edge, defined as a condition wherein light intensity of a first pixel is less than light intensity of a second pixel, and (ii) a second edge condition, or negative edge, defined as a condition wherein light intensity of the first pixel is greater than light intensity of the second pixel. Through comparison of this edge direction data with edge direction data determined from a previous illumination (or by comparing data extracted from this edge direction data) a measurement of the relative motion of the optical sensing device with respect to the illuminated portion of the surface is determined.

Optical pointing devices are already known in the art. U.S. Pat. No. 5,288,993, which is incorporated herein by reference, for instance discloses a cursor pointing device utilizing a photodetector array and an illuminated target ball having randomly distributed speckles. U.S. Pat. No. 5,703,356 (related to the above-mentioned U.S. Pat. No. 5,288,993), which is also incorporated herein by reference, further discloses (in reference to FIGS. 23A and 23B of this document) an optical pointing device in the form of a mouse which does not require a ball and wherein light is reflected directly from the surface over which the pointing device is moved.
The imaging technique used in above-cited U.S. Pat. Nos. 5,288,993 and 5,703,356 in order to extract motion-related information is based on a so-called "Edge Motion Detection" technique. This "Edge Motion Detection" technique essentially consists in a determination of the motion of edges (i.e. a difference between the intensity of pairs of pixels) in the image detected by the photodetector array. Edges are defined as spatial intensity differences between two pixels of the photodetector array. The relative motion of each of these edges is tracked and measured so as to determine an overall displacement measurement which is representative of the relative movement between the photodetector array and the illuminated portion of the surface.
More particularly, according to U.S. Pat. No. 5,288,993, edges are determined between pairs of pixels aligned along a first axis of the photodetector array (for example in each column of the photodetector array) and between pairs of pixels aligned along a second axis of the photodetector array (for example in each row of the photodetector array). FIG. 1 depicts three pixels of a photodetector array, a first pixel or current pixel P, a second pixel Pright aligned with the first pixel P along a first axis 101, and a third pixel Pup aligned with the first pixel P along a second axis 102. Pixels Pright and Pup are shown as being disposed on the right side and top side of pixel P for the purpose of explanation only. It will be appreciated that axes 101 and 102 may be orthogonal (as shown) or alternatively non orthogonal. It will also be appreciated that the pixels are not necessarily disposed so as to form a regular array having rows and columns. Other suitable arrangements may very well be envisaged.
For the purpose of simplification, the pixels of FIG. 1 are either shown as being white or hatched, a hatched pixel denoting an illuminated pixel. In this case, pixel P is illuminated and first and second edge conditions Ex, Ey exist respectively between pixels P and Pright along the first axis 101 and between pixels P and Pup along the second axis 102.
According to U.S. Pat. No. 5,288,993 and U.S. Pat. No. 5,703,356, the displacement measurement is evaluated, on the one hand, based on a normalized difference between the number of edges Ex which move in a first direction along the first axis 101 and edges Ex which move in the opposite direction along the first axis 101 (for example edges which move from left to right and right to left in each row of the photodetector array), and, on the other hand, based on a normalized difference between the number of edges Ey which move in a first direction along the second axis 102 and edges Ey which move in the opposite direction along the second axis 102 (for example edges which move downwards and upwards in each column of the photodetector array).
Relative motion of edges is determined by comparing the position of these edges in the photodetector array at a first point in time with the position of edges in the photodetector array at a subsequent point in time. The optical pointing device thus typically comprises a light source (such as an infrared LED) which intermittently illuminates the portion of the surface in accordance with a determined sequence, and the pixel outputs of the photodetector array are sampled in accordance with the determined sequence to provide basis for the determination of two successive edge frames that are compared to each other in order to determine a relative motion measurement.
According to one embodiment of U.S. Pat. No. 5,288,993 and U.S. Pat. No. 5,703,356 a differential technique is advantageously used in order to determine an edge condition between two pixels. According to this embodiment, an edge is defined as existing between two pixels if the ratio of intensities of the two photosensitive elements is larger than a determined level. An edge may thus be defined mathematically by the following Boolean expression:Intensity[PIXEL 1]>K Intensity[PIXEL 2]ORK Intensity[PIXEL 1]<Intensity[PIXEL 2]  (1)where K is a selected scaling factor.
The edge condition Ex between two pixels along the first axis 101 in FIG. 1 (or horizontal edge condition) may accordingly be defined by the following Boolean expression:Ex=Intensity[pixelP]>KIntensity[pixelPright]ORK Intensity[pixel P]<Intensity[pixel Pright]  (2)Ex at a high state meaning that there exists an edge between the current pixel and the pixel on its right.
Similarly, the edge condition Ey between two pixels along the second axis 102 in FIG. 1 (or vertical edge condition) may accordingly be defined by the following Boolean expression.Ey=Intensity[pixel P]>K Intensity[pixel Pup]ORK Intensity[pixel P]<Intensity[pixel Pup]  (3)Ey at a high state meaning that there exists an edge between the current pixel and the pixel on top.
It will be appreciated that conditions Ex and Ey above are not dependent on the direction or sense of the edge but simply indicate whether an edge exists or not between two pixels.
The above definitions and associated motion detection algorithms described in U.S. Pat. No. 5,288,993 and No. 5,703,356 have been used with great success in optical trackballs, i.e. optical pointing devices which detect light intensity patterns of an illuminated ball which is manipulated by the user. The above definitions and associated algorithms however require that the detected light intensity patterns exhibit clearly defined light intensity differences. Accordingly, the surface of the ball is covered with a plurality of randomly shaped markings in a color which exhibits great contrast with respect to the background. In addition, these markings (generally in the shape of spots) need to have a predetermined size. Referring to U.S. Pat. No. 5,288,993, the size of these markings is for instance said to be in the range of 0.5 mm2 to 0.7 mm2, with a density of about one spot per square millimeter. The size of these markings is relatively independent of the diameter of the ball but however depends largely on the resolution and size of the photodetector array. As mentioned in U.S. Pat. No. 5,703,356, the image of a single spot on the sensor should, as a minimum, cover the center to center distance between two adjacent pixels (or pixel pitch). In practice, however, the preferred typical dot size has been selected so that the surface of the image of the dot covers about five pixels. By complying with the above requirements, a number of edges which remains substantially constant and which is substantially less than the number of pixels may be determined and used for motion detection.
A serious problem however arises when applying the above motion detection scheme to optical pointing devices where the illuminated surface does not exhibit a predetermined pattern, such as in the case of an optical "ball-less" mouse which directly uses light reflected from a random surface, such as paper or the surface of a desk. An optical mouse not requiring any ball is described in U.S. Pat. No. 5,703,356, but this embodiment requires that the illuminated surface exhibits a suitable pattern having sufficient numbers of dark and light areas of sufficient size.
In any case, when applying the above technique to optical sensing devices which use an uncharacterised surface as reference for motion detection, edges as defined above are actually detected between every pixels. Since specific and well-defined patterns of edges cannot clearly be detected and tracked, it is accordingly impossible to derive any measurement of the relative motion between the optical sensing device and the illuminated surface. In practice, the above-mentioned motion detection technique is therefore not applicable and alternative solutions need to be found.
It is accordingly an object of the present invention to provide a solution that is more suited to an application in an optical pointing device where the illuminated surface which is used as reference for motion detection is uncharacterised and produces purely random light intensity patterns.
It should be mentioned at this point that some solutions to the above goal are already known in the art. U.S. Pat. No. 5,578,813 and No. 5,644,139 for instance disclose a motion detection principle which is based on correlation of consecutive image frames outputted by the photodetector array. According to this motion detection principle, comparison of light intensity between neighbouring pixels is however not performed to provide any information concerning spatial intensity differences (i.e. edges) between neighbouring pixels. Correlation of successive image frames as proposed in the just mentioned documents however implies some limitations. In particular, in order to derive a sufficiently precise measurement of relative motion, it is in practice required to illuminate the reference surface with a very low angle with respect to the surface, which angle is typically within sixteen degrees of the surface as more precisely described in U.S. Pat. No. 5,686,720. This leads to constraints in the construction of the optical pointing device.
In addition, image frame correlation techniques as proposed in these documents show some limitations when analysing grayscale image frames, the complexity of the correlation process increasing exponentially with the depth of intensity of the image. In practice, the application of the above correlation techniques to motion detection in optical device is limited to the analysis of binary black-and-white images.
In contrast, detecting spatial intensity differences (i.e. edges) between pixels of the image frame (or in other words pre-processing the image frames to extract binary data descriptive of light intensity differences between neighbouring pixels) and comparing this extracted data with previously extracted data in order to determine a measurement of relative motion is particularly efficient in terms of sensitivity to slight variations of intensity between pixels. With this technique, one can easily extract characterising features and patterns that may be tracked and exploited directly for motion detection. It may also be demonstrated that this technique is particularly robust and simple in terms of required processing.

This patent is subject to a terminal disclaimer.

Method and sensing device for motion detection in an optical pointing device, such as an optical mouse