A method of fabricating a semiconductor device includes the steps of forming a base diffusion layer in a predetermined region in a semiconductor substrate of a first conduction type, the base diffusion layer being of a second conduction type; forming first insulating films and simultaneously forming an emitter lead-out electrode and a collector lead-out electrode in regions above an emitter-contact-forming region and a collector-contact-forming region, the first insulating films extending on the emitter and collector lead-out electrodes, the emitter and collector lead-out electrodes including impurity corresponding to the first conduction type; forming second insulating films at sides of the emitter and collector lead-out electrodes; forming a base contact; forming a base lead-out electrode including impurity corresponding to the second conduction type; diffusing the impurity from the emitter lead-out electrode, the collector lead-out electrode, and the base lead-out electrode to form an emitter diffusion layer of the first conduction type, a collector contact diffusion layer of the first conduction type; and a base contact diffusion layer of the second conduction type; locating an end of the emitter diffusion layer and a first end of the base contact diffusion layer at positions directly below a portion of the second insulating films which extends at a side of the emitter lead-out electrode; and locating a second end of the base contact diffusion layer and an end of the collector contact diffusion layer at positions directly below a portion of the second insulating films which extends at a side of the collector lead-out electrode.

1. Field of the Invention
This invention relates to a method of fabricating a semiconductor device having a self-aligned structure.
2. Description of the Prior Art
Y. Kobayashi et al. published "High Speed IC fabricated by SST4 process" in the 1986 National Meeting of the Institute of Electronics and Communication Engineers of Japan. This publication relates to an improvement of an SST (super self-aligned process technology) structure. Specifically, the improved SST structure additionally has a collector compensation layer. According to this publication, in a fabricated transistor, an emitter width was equal to 0.35 .mu.m and the distance between a collector and an emitter was equal to 0.65 .mu.m, and the distance between the emitter and a base was also equal to 0.65 .mu.m.
M. Suzuki et al. published "A 165 ps/gate 5000-Gate ECL Gate Array" in Extended Abstracts of the 17th Conference on Solid State Devices and Materials, Tokyo, 1985, pp. 377-380. According to this publication, a 5130-gate ECL gate array has been developed with a basic gate delay of 164 ps/gate at a power dissipation of 1.5 mW/gate. This gate array is fabricated by using 1.5 .mu.m rule super self-aligned process technology (SST-1A) combined with deep U-groove isolation and three-level metallization technology. This device permits the customization of a dual 40-bit data link control LSI equivaling 3654 gates for the multiprocessing system. The power dissipation of this LSI is 4.8 W/chip.
U.S. Pat. No. 4,693,782 discloses a method of fabricating a semiconductor device having the structure of self-alignment between an emitter contact and a base contact.
U.S. Pat. No. 4,908,324 discloses a method of manufacturing a bipolar transistor having the structure of self-alignment between an emitter contact and a base contact.
FIG. 1 shows a transistor with the base and the emitter formed by a self-aligned process which is published in the 1983 National Meeting of the Semiconductor Material Department of the Institute of Electronics and Communication Engineers of Japan.
As shown in FIG. 1, the prior art transistor includes a p-type semiconductor substrate 1, an n-type buried layer 2, an n-type epitaxial layer 3, an isolating region 4 consistinf of an SiO.sub.2 film, a base diffusion layer 5, an emitter lead-out electrode 9 consisting of a polycrystalline silicon film containing arsenic, a collector lead-out electrode 10 consisting of a polycrystalline silicon film containing arsenic, a base lead-out electrode 13 consisting of a polycrystalline silicon film containing boron, an emitter diffusion layer 15, a base contact diffusion layer 16, a collector contact diffusion layer 17, electrode leads 21-23 of aluminum or the like, SiO.sub.2 films 50, 52, and 53, an Si.sub.3 N.sub.4 film 51, and an emitter contact 100.
In the prior art transistor of FIG. 1, the base and the emitter are formed by a self-aligned process. During the self-aligned process, the base electrode 13 is formed, and then an SiO.sub.2 film is formed. The SiO.sub.2 film is subjected to an anisotropic dry etching process to leave the SiO.sub.2 film 53 on a side surface of the base electrode 13. In addition, an opening for the emitter contact 100 is provided in the SiO.sub.2 film. The self-aligned process enables smaller emitter and base, thus reducing the emitter-base capacitance, the base-collector capacitance, and the base resistance. The reductions of these parameters result in a higher operation speed of the transistor.

Method of fabricating semiconductor device

Matsushita Electric Industrial Co., Ltd.


An optical filter or valve comprises autonomously tunable liquid crystal filters in which photoactivated materials such as a photoconductive and photovoltaic substrates or films are used to produce or control application of an electric field to a liquid crystal material to tune the liquid crystal material to the wavelength of the incident light or radiation that is illuminating the filter thereby enabling the filter to automatically and autonomously filter the incident light or radiation.

Tunable liquid crystal filters that vary the electrical-optical properties of liquid crystal materials have a variety of uses. Currently, tunable liquid crystals use direct current (DC) fields to control the tuning of an active system. Such tunable liquid crystal filter systems are limited by the fact that the optical wavelength must be known a priori and the tuning must be controlled by an electric device such as by cueing to tune the liquid crystal medium to filter the optical wavelength that is anticipated.

Autonomously tuning photoconductive and photovoltaic light valves

The United States of America as represented by the Secretary of the Air Force


A low profile elbow, and a process of manufacturing the same, includes a tube secured at two different location in two different planes of a base, wherein an end surface of the tube is positioned at an acute angle with respect to a tube axis, and wherein the tube defines a center of curvature positioned lower than a lower surface of the base.

Commercial Vehicles (such as long distance eighteen wheel trucks) and industrial equipment typically include an engine exhaust device using a full radius elbow which turns the exhaust gas flow from the engine through an angle of ninety degrees or more. These prior art full radius elbows define a height that often interferes with adjacent components in the engine compartment that are positioned directly adjacent the full radius elbow.
In order to reduce the height of the ninety degree turn of the exhaust gas when compared to the full radius elbow, some commercial vehicles utilize two tubes joined at a right angles. Such a design reduces the height of the engine exhaust device but presents a significant increase in resistance to exhaust gas flow, thereby increasing exhaust back-pressure. Engine manufacturers typically limit the maximum permissible exhaust back-pressure in applications for their engines. Right angle fabrications such as these typically exceed the maximum permissible back-pressure limits. A right angle fabrication of this type is also relatively weak and vulnerable to vibration fatigue failure because the end tube is only welded to one side of the base tube.


A fuel system for an aircraft is provided including a fuel tank configured to receive fuel and a fuel pump. The fuel pump includes a motor disposed proximate the fuel tank. The fuel pump further includes a power supply in electrical communication with the motor and disposed outside the fuel tank. The fuel pump further includes an impeller disposed within the fuel tank and rotatably coupled to the motor. The impeller includes a shaft having a first end and a second end spaced from the first end with the motor coupled to the first end. The shaft has a resistivity greater than the resistivity of the fuel tank between the first end and the second end to minimize electrical transfer between the motor and the fuel.

Considerable testing and analysis is necessary to address single and dual-fault tolerance requirements for rules and regulation pertaining to fuel tank ignition prevention. One approach to address these requirements is to allow electrical power to enter the fuel tank, quantify the level of the electrical power, design for the level of the electrical power, and test for the level of the electrical power. When allowing electrical power to enter the fuel tank, all foreseeable failure modes that can create an ignition source must be accounted for by testing designs, implementing design changes where required, increasing maintenance inspections, and meeting complex certification strategies. Another approach is to minimize electrical transfer into the fuel tank thereby minimizing the foreseeable failure modes. One component of the fuel system that has the potential of allowing electrical current to enter the fuel tank is a fuel pump.
Conventional fuel pumps include a motor disposed within the fuel tank and a power supply disposed outside the fuel tank, and in direct electrical contact with, the fuel tank. An electrical fault occurring within the power supply may enter the fuel tank through the direct electrical path between the power supply and the fuel tank. Further, the power supply is cooled utilizing a fuel-cooled wash plate, which is thermally conductive. The wash plate may also inadvertently act as an electrical conductivity path between an electrical fault occurring within the power supply and the fuel tank. The fuel pump further includes an impeller disposed in the fuel tank with the impeller coupled to the motor by a shaft. The shaft of the impeller may act as an electrical conductivity path between an electrical fault occurring within the motor and the fuel tank.
Accordingly, it is desirable to provide an improved fuel system. Furthermore, other desirable features and characteristics will become apparent from the subsequent summary and detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.


The present invention provides an improved container holder having a unique shape that facilitates efficient manufacturing of the holder and printing of advertising material at a predetermined location on the holder. The container holder comprises an elongate body delimited by top and bottom edges and first and second end edges. The top and bottom edges define straight lines that are parallel to each other. The body further comprises a first tab positioned at the first end edge of the body, and a second tab positioned interiorly of the body, and generally adjacent to the first tab. The tabs are positioned at an acute angle with respect to one of the top and bottom edges, and extend away from each other in opposite directions. The body further comprises a first slot positioned adjacent the second end edge, and a second slot positioned generally adjacent the first slot. The first and second slots are positioned so as to receive the corresponding first and second tabs, the slots being positioned at an acute angle with respect to one of the top and bottom edges. The body further comprises an outer surface having a texture embossed thereon so as to increase the grippability and insulating properties of the container holder.

Container holders are used to reduce the rate of heat transfer between a container and a hand gripping the container holder. Container holders also may be used to increase the grippability of the container. Additionally, container holders may be used to advertise a product by including advertising material printed on an outer surface of the container holder.
Conventional container holders typically are manufactured with arcuate top and bottom edges such that when the holder is fastened in an assembled configuration, the holder forms a tapered sleeve that may be positioned about a tapered container. Such arcuate top and bottom edges lead to inefficient manufacturing in that a large portion of a sheet of material, from which the holders are cut, remains unused and numerous cuts must be made in the sheet to form the holder. In addition, the arcuate top and bottom edges lead to nonuniform spacing of the container holders within the sheet of material such that advertising material printed on the container holders is not predictably centered thereon.
Conventional container holders may be permanently fastened in the assembled configuration by adhesive placed along overlapping end edges. These permanently assembled container holders are expensive to ship and store in that they require a relatively large volume of space. Releasably fastenable container holders may be assembled by interlocking mating webs, the webs created by oppositely extending cuts that sever the top and bottom edges, respectively, of the holder. The mating web configuration provides a "tear drop" shaped cross section when the holder is assembled and provides outwardly extending tabs that may become torn and that may snag other holders upon stacking. Accordingly, to stack such a holder, the holder must be pressed into a shape having a circular cross section while simultaneously preventing tearing or snagging of the webs.


In an image compression system using a typical image compression scheme, a pointer array is provided to point to each of the many MCUs in a compressed image file. From all the blocks of an image, a subset of the blocks is selected as a virtual image. The virtual image is edited, and each edited block is compressed into an edited block. The edited block is compressed into an edited MCU and placed in an edited block region, and the pointer to the original MCU is changed to point to the new MCU. In this way, the pointer array can be modified to perform an Undo operation. An edge table is provided to hold values where each value, when combined with the differential value for a block on the edge of the virtual image, provides an absolute value for the block without reference to blocks beyond the edge of the virtual image. The entries in the edge table are determined from the compressed MCUs without the blocks being fully decompressed. More than one edge table can be provided. In an image editor, a virtual image is decompressed from a compressed image, the virtual image is processed, and recompressed. The recompressed, edited blocks are then placed in a edited block memory.

The present invention relates to the field of editing compressed images. More specifically, in one embodiment the invention provides means for editing portions of compressed images without decompressing the entire image.
Modern color imagery for cameras and scanners require huge amounts of memory to store image files containing a data representation of the input or scanned image. A typical image such as that used with a color copier with 8.5".times.11" (216 mm.times.297 mm) paper, a resolution of 400 dots per inch (15.75 per mm), and 3 bytes (24 bits) to represent the intensity of each dot, would occupy 44.88 megabytes of memory. In addition to the size of the memory, the memory must have high bandwidth for real time applications, such as a color copier where 15 pages per minute is a typical demand. This implies a bandwidth, or data rate, of 11.22 megabytes/second. Both these requirements drive up the cost of imaging systems. Compression techniques have been used to solve both the bandwidth and the storage problems for quite a while. With compression, an image file can be stored in less memory, and moves faster across any bandwidth limited channel because of the lower number of bits used to represent an image. Compression involves passing the raw image data into a compressor, which combines and analyzes the patterns in the raw data to produce a compressed image file where the original image is not readily discernable without a corresponding decompression.
If an image is to be edited, scaled, rotated, or otherwise processed, random access to any or all of the pixels is required. Once the processing is complete, the edits must be saved to the image file. If the image file being processed is compressed, the conventional means for obtaining random pixel access is to decompress the image into a frame store, perform the processing, and then recompress the image into a new image file. The problem with this is that no memory is saved by decompressing, since memory is needed for the frame store. The bandwidth is also lowered, since compression and decompression of entire images takes time. This additional processing time and memory is often wasted, since even the most expensive display in an imaging system could not display the entire image a full resolution.
One solution is to allow only limited in-line real-time manipulation, manipulating the image as it moves through a channel from one compressed image to another. Unfortunately, only a small area can be processed at once, and such a scheme cannot be adapted to interactive editing.
Compression methods for compressing image data are known. One such compression standard is JPEG (Joint Photographic Experts Group). Other standards include JBIG, Fax G3 or G4, and GIF. In JPEG, to give one example, an image is represented by a two-dimensional array of picture elements, or pixels. If the image is grayscale, each pixel is represented by an intensity value, and if the image is color, each pixel is represented by several values. Before compressing the image data, the image is divided into blocks of eight by eight pixels each. Within each block, the 64 pixels are transformed, using a discrete cosine transform, into 64 frequency amplitudes, a DC value and 63 AC values. Rather than encoding the DC value directly, the DC value of the block preceding the current block is subtracted from the DC value of the current block, and the resulting differential DC value is stored. Because the typical image being compressed has a constant color within each eight by eight pixel block and a relatively slowly changing average color value, this scheme results in greatly compressed images. Many other image compression schemes use similar techniques for compression and the use of differential values.
An image comprises raw pixel data indicating color or intensity at a number of pixel locations, usually a two-dimensional grid. Pixels are grouped into blocks, and each block is compressed separately. The process of compression involves transforming the 64 values associated with the block into one differential DC value and 63 AC values, and reducing the number of bits needed to describe the transformed values through entropy encoding. Each block is compressed into a minimum coded unit (MCU), the MCUs which make up a compressed image are tagged with identifying information, such as the block location within the image, length data to indicate how many bits are contained in the MCU, and the like, and the MCUs are stored sequentially in an image file. Length data is needed since MCUs vary in length. The length is determined by the entropy encoding step. A block which is very ordered, such as a uniformly colored block will compress into a relatively small MCU as compared to a block with more color variation. The process of entropy encoding is generally referred to as coding, whereas a compressing process involves blocking, cosine transforming and coding image data. Significantly, differential DC values can be read from an MCU which has been decoded only, since full decompression is not necessary. This savings in processing resources may be significant since cosine transforms and inverse transforms can be very computationally intensive operations.
To decompress an image, each MCU from an image file is decompressed into a block, by reverse operation of the differential encoding of the DC value and by an inverse cosine transform. While differential encoding of slowly changing values from block to block increases the compression, it increases the difficulty of decompressing only a part of an image, since decompression of some MCUs in the partial image will require reference to MCUs which are not in the partial image. Further difficulties arise in partial decompression when the partial image is edited and recompressed. Because the degree of compression depends on the image data, an edited partial image will usually be a different size when compressed compared with the original image. Consequently, simply replacing the MCUs from the partial image with the MCUs from the edited partial image is impractical, unless the entire image is decompressed, edited and recompressed. From the above it is seen that an improved method for manipulating and editing compressed images is needed.


Provided is a bistable driving method for an electrowetting display, comprising: setting a non-selected voltage for one or more writing rows; switching a row voltage of the one or more writing rows from the non-selected voltage to a selected voltage; applying the digital voltage on at least one column of digital electrodes to be written; switching the row voltage of the one or more writing rows from the selected voltage to the non-selected voltage, and decreasing the digital voltage applied to the at least one column to a voltage less than the opening voltage minus the selected voltage; and applying the steps above to next one or more writing rows until an entire display screen is written.

Electrowetting displays are becoming more and more attractive due to high brightness, high contrast ratio, large viewing angle and fast switching speed. Resulting from these properties, the electrowetting displays are suitable for video application. In theory, the electrowetting displays can be grouped into transmissive type displays and reflective type displays. For a reflective electrowetting display, energy consumption can be relatively low, as backlight is not required.
An electrowetting display generally comprises a closed electrowetting unit, polar and non-polar liquids (such as water and oil) having different optical properties and contained in the unit, several electrodes (such as digital electrodes and common electrodes) for controlling the liquid contained in the unit, and a front plate and a rear reflective plate. These immiscible liquids can be displaced by applying a voltage to the electrodes. In a balance state (in which no voltage is applied to the electrodes), the polar and non-polar liquids are naturally delaminated in the closed unit, thus forming a thin film, such as an oil film. In this state, i.e., a colored state, the thin film covers a reflective area and the unit or the pixel is displayed in color or black. By applying the voltage at two ends the electrodes, the delaminated and colored state is no longer satisfactory in terms of energy, and the unit or the pixel can move the polar liquid to make the polar liquid be contacted with an electrode surface, thus pushing the oil film to a corner of the pixel. As a result, the non-polar liquid is displaced to expose a reflective or white surface below. Therefore, in this state, i.e., a white state, the unit or the pixel is displayed as white or bright. An interaction between static electricity and capillary force determines how far the non-polar liquid is displaced to a side. A detailed description of a structure of the electrowetting display refers to the Chinese patent application CN103984088A.
In other words, the electrowetting display is usually driven by applying the voltage to the electrodes, thus affecting the "wetting" of the electrode surface, i.e., a hydrophilicity of the electrode surface. A high voltage means that a large area of electrode surface is covered with water, so that the electrowetting display has a low absorbance. Until now, the electrowetting display is driven by a constant voltage applied to the digital electrodes, but the common electrodes are at ground potential. The oil film covers the electrode surface when no voltage is applied. A minimum voltage is required to open the oil film (which is partly caused by a surface tension), which is called an opening voltage. At this voltage, the surface tension is destroyed and the pixel is suddenly switched to an "opening" state. When the voltage is lowered, the pixel cannot be closed at the same voltage, but is only closed at a much lower voltage, which is called a closing voltage. This hysteresis phenomenon is usually deemed as an obstacle, and the display is operated in an area with the voltage higher than the closing voltage, displaying continuous behaviors with increased and decreased voltages. In addition, a display surface is usually designed to have a structure that reduces the surface tension to avoid this hysteresis phenomenon. Because this addressing method requires each pixel to have a separate drive electrode, an active matrix backplane is required to address a larger number of pixels. However, by making full use of this hysteresis phenomenon to drive the electrowetting display, it is possible to use only a passive matrix (thus being cheaper) structure to drive a larger array.

Bistable driving method for electrowetting display and related electrowetting display

Academy of Shenzhen Guohua Optoelectronics

Shenzhen Guohua Optoelectronics Co., Ltd.


A self-actuating robot or vehicle tether capable of moving itself, remaining free while traversing around obstacles, and free itself is disclosed. In a preferred embodiment of the invention, a valve is mounted to the tether or robot. An inflow conduit attached to or in the tether is connected to the valve. A fluid flows through the tether and the valve is opened and closed to create a waterhammer effect in the inflow conduit. The forces created on the tether from the waterhammer effect result in motion of the tether and in freeing of the tether from obstructions. Closing and opening the valve further creates pressure changes in the tether, thereby causing momentary dimensional changes in the tether. In an alternative embodiment, a plurality of valves are placed along the tether. Pulsing of the plurality of valves while a fluid flows through the tether results in the tether effectively moving itself.

1. Field of the Invention
The present invention relates to mobile tethers providing a physical connection between two locations. More specifically, the present invention relates to a system and method for providing an actuated tether capable of moving itself, remaining free while traversing around obstacles, and/or freeing itself when pinned by debris or restrained by obstacles.
2. Description of the Related Art
A longstanding goal of mobile robotics is to allow robots to work in hazardous or inaccessible environments. Post-disaster urban search and rescue is one of the most hazardous environments imaginable, and victims are often in unreachable locations buried beneath unstable rubble. The goal of rescue robotics is to extend the capabilities of human rescuers while also increasing their safety. Robots can enter voids too small or deep for humans and can survey larger voids that humans are not permitted to enter until, for example, a fire has been put out or a structure has been reinforced. They can carry various types of equipment, such as thermal imagers, cameras, hazardous materials sensors, medical supplies, or even food and water into the interior of a rubble pile far beyond where searchers may otherwise reach, such as with a boroscope.
In practice, however, rescue robots have encountered a number of difficulties involving radio transmission inefficiency, poor maneuverability, and tethers becoming caught. Numerous publications have discussed experiences with rescue robots at actual disaster sites. One such publication is "Human-Robot Interactions during the Robot-Assisted Urban Search and Rescue Response at the World Trade Center," Casper, J., and Murphy, R. R., IEEE Transactions on Systems, Man and Cybernetics Part B, Vol. 33, No. 3, pp. 367-385, June 2003, which is hereby incorporated by reference in its entirety.
Rescue robots may come in many forms and varieties. Robots likewise may be polymorphic, meaning that the robot's effectors (components that perform actuation and any connections relating to those components) may be dynamically changed to fit the environment. Some examples of existing robots are listed Table I in "How UGVs Physically Fail in the Field," Carlson, J., and Murphy, R. R., submitted IEEE Transactions on Robotics for publication and publicly available at crasar.csee.usf.edu/research/Publications/CRASAR-TR2004-16.pdf, which is hereby incorporated by reference in its entirety. The robots may be of a variety of different sizes, may use different means of locomotion, may use different types of power, may have different modes of control, may incorporate different tools or equipment, and may have different modes of communication. Some examples of robot types and features are described in "Human-Robot Interaction in Rescue Robotics," Murphy, R., IEEE Systems, Man and Cybernetics Part C: Applications and Reviews, special issue on Human-Robot Interaction, Vol. 34, No. 2, May 2004, which is hereby incorporated by reference in its entirety.
In many environments in which rescue robots may be needed, however, the most useful robot size is about the dimensions of a shoebox. This limitation in size can preclude use of certain types of controls that, for example, may require multiple sensors, certain types of power such as batteries, or certain means of locomotion.
Reliability of the rescue robots obviously is an important issue. Rescue robots can fail for a wide variety of reasons. Examples of rescue robot failures are described and discussed in the previously referenced articles and in other published articles such as "Follow-up Analysis of Mobile Robot Failures," J. Carlson, R. Murphy, A. Nelson, IEEE International Conference on Robotics and Automation (ICRA), April 2004, which is hereby incorporated by reference in its entirety.
Communication has been a large issue with respect to rescue robots. Wireless robots typically are larger and more mobile than tethered robots, but they still require a safety line and communication are easily lost in the harsh environment in which they are used. For example, following the World Trade Center disaster on Sep. 11, 2001, a communication failure caused the temporary loss of an untethered, teleoperated robot. As such a disaster site, usable communication frequencies are very limited because most frequencies are reserved for emergency response agents. Additionally, thick concrete walls and steel debris often obstruct radio communication between the operator and the robot. These communications difficulties often make tethered robots more reliable and useful than untethered robots in this kind of environment.
Tethered robots additionally may be much smaller than their untethered counterparts due to the elimination of batteries and wireless communications equipment. A smaller size allows tethered robots to search areas that would be inaccessible by larger robots.
Lack of mobility also can hinder robotic search and rescue efforts. For example, it is often beneficial to deploy robots through holes or vertical pipes. Tethers are beneficial in these situations as tethered robots can be safely lowered or raised vertically. Additionally, in the event of a robot malfunction, tethers may be used for robot recovery.
Drawbacks of using conventional tethers include increased drag and a tendency to catch on obstacles. Conventional tethers therefore may limit the depth and path of exploration. The use of tethers also requires an additional operator to handle the tether. This operator attempts to avoid breaking or locking the tether on debris as the robot moves into the site. Tether managers, of course, are at risk since they often work close to structures with questionable stability during the deployment.
Many of these issues also pertain to other applications of remotely controlled vehicles in inaccessible or hazardous locations. For example, vehicles for pipe inspection and repair or military operations in trenches and caves encounter similar problems with communications and tether management. Examples of such other applications are disclosed in U.S. Pat. Nos. 6,697,710 and 4,862,808, which are hereby incorporated by reference in their entirety. The present invention described below is equally applicable to these other applications in addition the field of rescue robots.

President and Fellows of Harvard College


A system for galvanic isolation between an analog input signal and an analog output signal, which system performs an analog to digital conversion of the input signals into input digital data. As a result, input parameters can be corrected in a nearly perfect way.

1. Field of the Invention
The present invention relates to a system and a method for converting an input signal to an output signal, which system performs an digital conversion of the input signals into input digital data, which system performs digital conversion into the output signal, which system performs separate digital conversion of a plurality input signals.
2. Description of Related Art
German Patent Application DE 44 34 553 A1 concerns a field digital converter. The analog signal is separately converted so that at first digitalization of the current is performed, and parallel to this process, digitalization of the voltage is performed. These two digital signals are then combined in an arithmetic logic circuit where a common signal is achieved which signal is then sent through a galvanic insulator before the signal is sent to a data communication system.
U.S. Pat. No. 6,329,817 discloses a sensor for measuring a parameter including at least one transducer adapted to provide an analog transducer signal, and at least one converter adapted to convert the analog transducer signal into a digitized transducer signal, and a memory device associated with the converter capable of receiving the digitized transducer signal directly from the converter. The memory device is configured to provide a digitized output value from a memory location, the memory location being associated with or corresponding to the digitized transducer signal received by the memory device.
In U.S. Pat. No. 6,329,817, there is no disclosure any galvanic isolation of the signals in that an analog signal is transmitted in parallel to the digital signal for subsequent combination in an analog adder circuit. No galvanic isolation is performed suggested for the analog or digital communication line.

System for linear interpolation in multiple dimensions


A rapid prototyping system forms three-dimensional objects by depositing layers of material on a substrate. A planer stator containing a grid of stator elements is positioned above and generally parallel to the substrate. An extrusion head is magnetically suspended below the stator and is separated from the stator by an air bearing. An electromagnetic drive receives control signals from moving the extrusion head relative to the grid of stator elements. An umbilical provides mechanical damping to the head to reduce resonance of the head during movements.

The present invention relates to the field of three-dimensional prototype modeling. In particular, the present invention is a rapid prototyping system for forming three-dimensional objects of predetermined design by depositing multiple layers of a material in its fluid state from an extrusion head onto a base. The material is selected and its temperature is controlled so that it solidifies upon extrusion or dispensing onto the base, with the build-up of the multiple layers forming the desired object. In the present invention, the extrusion head or heads are driven by a linear motor and are attached to an umbilical which provides mechanical damping to reduce resonance of the head during movements.
A rapid prototyping system involves the making of three-dimensional objects based upon design data which is provided from a computer aided design (CAD) system. Examples of apparatus and methods for rapid prototyping of three-dimensional objects by depositing layers of solidifying material are described in Crump U.S. Pat. No.5,121,329, Batchelder et al. U.S. Pat. No. 5,303,141, Crump U.S. Pat. No. 5,340,433, Batchelder U.S. Pat. No. 5,402,351, Batchelder U.S. Pat. No. 5,426,722, Crump et al. U.S. Pat. No. 5,503,785, and Abrams et al. U.S. Pat. No. 5,587,913, all of which are assigned to Stratasys, Inc.
Rapid prototyping allows the user to turn a design into a prototype to test form, fit, and function. There is a continuing need to produce larger parts through rapid prototyping. As the size of the parts being produced increases, higher speed movement of the extrusion heads and precise control of extrusion head position is required.

High performance rapid prototyping system


A weighing system that operates according to the principle of electromagnetic force compensation, having two connecting rods (2, 3) which are fashioned as a parallel guide and connect a load receiver (4) to a base area (1) fixed to the housing, and having an angle lever (5) mounted on the base area. The force due to weight that is transmitted by the load receiver acts upon the short lever arm (5′) of the angle lever via a coupling element, and a coil projecting into the air gap of a permanent magnet system (7) is fastened to the long lever arm (5″). The weighing system occupies only a small area since the long lever arm takes the form of a vertical lever arm and extends, at least in part, in the area underneath the connecting rods of the parallel guide. The permanent magnet system is likewise arranged underneath the connecting rods of the parallel guide.

The invention relates to a weighing system operating according to the principle of electromagnetic force compensation, having two connecting rods which, in the form of a parallel guide, connect a load receiver to a base fixed to the housing, and having an angle lever mounted to the base area. The weight force transmitted by the load receiver acts on the short lever arm of the angle lever, and a coil projecting into the air gap of a permanent magnet system is fixed to the long lever arm of the angle lever.
A weighing system of this type is disclosed, for example, in German publication DE 31 27 939 C2. German publication DE 195 40 782 C1 also describes such a weighing system, which is in addition provided with a second angle lever.

Weighing system having an angle lever with a long vertical lever arm


To provide a semiconductor integrated circuit device that reduces charging and discharging currents flowing through clock tree synthesis, thereby reducing current consumption of entire circuits of the semiconductor integrated circuit device.

When the clock synchronous type circuit including a plurality of flip-flops (that will be referred below as F/Fs) that operate in synchronization with the reference clock is formed in the semiconductor integrated circuit device such as an ASIC (Application Specific Integrated Circuit), the reference clock is supplied to each of the F/Fs using a plurality of clock buffer circuits for distributing the reference clock.
FIG. 7 is a circuit diagram showing a conventional clock buffer circuit provided for a semiconductor integrated circuit device, and FIG. 8 is a timing diagram showing input and output waveforms for the clock buffer circuit shown in FIG. 7. FIG. 9 is a circuit diagram showing a configuration of clock tree synthesis using the clock buffer circuit shown in FIG. 7.
As shown in FIG. 7, the conventional clock buffer circuit includes a first inverter 5 and a second inverter 6. The first inverter 5 is constituted from a P-channel field-effect transistor (that will be referred below as a P-channel transistor) 51 and an N-channel field-effect transistor (that will be referred below as an N-channel transistor) 52. Gates of the P-channel transistor 51 and the N-channel transistor 52 are interconnected, and drains of the P-channel transistor 51 and the N-channel transistor 52 are interconnected. The P-channel transistor 51 and the N-channel transistor 52 use different types of carriers in channels. The reference clock is input to the respective gates of the P-channel transistor 51 and the N-channel transistor 52. The second inverter 6 for driving a load is constituted from a P-channel transistor 61 and an N-channel transistor 62. The gates of the P-channel transistor 61 and the N-channel transistor 62 are interconnected, and the drains of the P-channel transistor 61 and the N-channel transistor 62 are interconnected. Sources of the P-channel transistors 51 and 61 are connected respectively to a power supply VDD, while the sources of the N-channel transistors 52 and 62 are connected respectively to a ground potential GND.
Since the conventional clock buffer circuit is based on an assumption that the clock buffer circuit is for general-purpose use in a device such as the ASIC, the clock buffer circuit outputs a waveform that is the same as the input reference clock so as to accommodate both the clock synchronous type circuit that operates in synchronization with the rising edge flank of the reference clock and the clock synchronous type circuit that operates in synchronization with the falling edge flank of the reference clock. When the reference clock with a duty cycle of 50% has been input, for example, the clock buffer circuit outputs a pulse train with the duty cycle of 50% having substantially same delays in rise and fall times and with the rising and falling edges flank that are the same as those of an input waveform.
For this reason, in the conventional clock buffer circuit, the P-channel transistor of each of the inverters is formed to be larger than the N-channel transistor. In other words, the P-channel transistor is formed to have a gate width wider than the N-channel transistor. More specifically, as shown in FIG. 7, the first inverter 5 in a front stage is formed of the P-channel transistor 51 having a gate width Wp of 8.472 μm and the N-channel transistor 52 having a gate width Wn of 2.82 μm, while the second inverter 6 in a back stage is formed of the P-channel transistor 61 having the gate width Wp of 16.944 μm and the N-channel transistor 62 having the gate width Wn of 6.24 μm. A transistor size ratio Wp/Wn of the first inverter 5 then becomes 3.00, while the transistor size ratio of Wp/Wn of the second inverter 6 becomes 2.72. This arrangement is adopted because when a transistor size is the same, the P-channel transistor has lower driving capability than the N-channel transistor.
In the conventional semiconductor integrated circuit device, the clock tree synthesis as shown in FIG. 9, which will be referred to below as CTS, was performed using a clock buffer circuit 50 described above. The clock having same duty ratio and skew is thereby distributed to a plurality of F/Fs provided for the clock synchronous type circuit. FIG. 9 shows an example where posedege F/Fs 60 that operate at the rising edge flank of the reference clock are connected to the CTS.
Patent document 1, for example, proposes a configuration in which the transistor size ratio of the P-channel transistor and the N-channel transistor in a CMOS circuit is made asymmetrical in order to transmit a signal through the semiconductor integrated circuit device at high speed.
[Patent Document 1]
JP Patent Kokai Publication No. JP-A-8-181596

Abstract: In a semiconductor integrated circuit device including a clock synchronous type circuit that operates in synchronization with either of rising and falling edges flank of a reference clock and a plurality of clock buffer circuits for distributing the reference clock to the clock synchronous type circuit, each clock buffer circuit is constituted from a first transistor that drives a load at one of the edges flank of the reference clock with which the clock synchronous type circuit does not operate in synchronization and a second transistor that drives the load at the other edge flank of the reference clock. A gate width of the first transistor is set so that a change in the edge flank is slowed down, provided that a pulse waveform of the reference clock is not destroyed. A carrier type of the second transistor is different from the carrier type of the first transistor, and the second transistor is formed to have the gate width larger than the first transistor.


A locking system is disclosed which comprises a microcomputer controlled lock with multiple level keying, i.e. multiple keys having different functions in the locking system. A key reader, for example punch card or magnetic type, reads key code into the microcomputer. A read/write memory has a predetermined number of assigned key codes stored therein and a read-only memory has a control program stored therein for control of the microcomputer. An electrically controlled actuator for the locking means is coupled with an unlocking output of the microcomputer. The control program comprises a main program and a plurality of subroutines each stored at a different location in the read-only memory. A function table has a number of pointers each of which points to the memory address of one of the subroutines. The number of pointers in the function table is equal to the number of locations in the key code memory. Decoding means operative under program control in conjunction with a control code on the key points to selected locations in the key code memory and the function table corresponding to the control code. The microcomputer, under control of the main program, compares the primary and secondary key codes from the selected key with the assigned key code at the location in the key code memory. If there is a match, the microcomputer then operates under the control of the subroutine at the memory address pointed to by the function table to execute the function of the selected key.

Hotels, office buildings and the like require door locks on a large number of individual rooms. In a hotel, for example, the door lock of each guest room should have a different key for successive guests. Also, at a given time, a guest room door lock must be operable by different keys assigned to hotel personnel, such as the maid, housekeeper and other levels of hotel management. For security purposes, the keys for each lock must be readily changeable.
In the prior art, locking systems for hotels and the like have been developed which utilize electronic code responsive logic circuits for operation of a lock mechanism.
The Aydin U.S. Pat. No. 4,177,657 granted Dec. 11, 1979 discloses an electronic lock system which senses code on a key and compares it to a code stored in a memory. When the key code matches the stored code, the lock activates a clutch operated bolt and may also change the stored code to a new code. The Aydin patent discloses a microcomputer control system for the lock. Each key has a control code, a primary key code and a secondary key code stored thereon. A read/write memory stores a predetermined number of assigned key codes and a read-only memory has a control program stored therein for control of the microcomputer. A key reader is coupled with the microcomputer and is adapted to coact with any of the keys to read the code stored thereon into the microcomputer. Different keys are used for different access levels in accordance with the control code on the key. The access levels are designated as guest key, floor master, section master, security master, etc. If a code match is obtained, the system performs two major functions, namely, enabling the clutch to permit door opening and changing of the stored code in the memory. In addition, there are certain auxiliary functions, namely, inhibiting opening to permit the change of code, a special key which can be used once only and a double lock function.
The Sabsay U.S. Pat. No. 3,821,704 discloses an electronic locking system suitable for hotels and the like and having multiple levels of master keys. Each lock mechanism is controlled by a decoding circuit having a changeable binary memory. A key has two decodable information fields, namely, a key field and an authorization field. When the key field matches the combination stored in the decoding circuit memory the lock opens. If there is not a match, the authorization field and the combination field are compared and if they are equal the key field is stored in the memory and the lock is opened.
The Dimitriadis U.S. Pat. No. 3,797,936 discloses an electronic lock which is provided with an optically encoded key. If the code on the key corresponds to the stored code, the circuit activates a mechanism which opens the lock. The Astin U.S. Pat. No. 4,396,914 discloses a microprocessor controlled lock. In this system an electronic circuit compares the content of the memory with the combination code and enables the lock device if a match is found. If the key card is a new one the circuit calculates a new combination code and if it matches that on the key card the memory is loaded with the new combination code.
A general object of this invention is to provide an improved security device which is especially adapted for use in controlling a door lock mechanism and which overcomes certain disadvantages of the prior art.


One feature pertains to a modular design of a motherboard for a computer system. The mother board is disaggregated into a CPU board and an IO board. The CPU board contains at least one CPU, the associated memory subsystem and the voltage regulator module. The integrated IO ports escape to a high speed connector mating with its counterpart on an IO board which contains all peripheral devices including system logic not part of the CPU. In a multi-socket configuration the CPUs are on the CPU board and the processor interconnects are routed directly in a point to point manner.

The backbone of a computer system is the mainboard or motherboard that typically contains the central processing unit (CPU), a system logic or chipset and various on-board devices, e.g. Ethernet controller, or expansion connectors such as peripheral computer interconnect express (PCIe) slots. Most motherboards are monolithic designs, that is, a single printed circuit board (PCB) accommodates the CPUs and all peripherals regardless of whether they are chip-down, i.e. soldered on to the PCB or removable cards.
In server computers, multiple CPUs sharing a single system logic and being interconnected through a dedicated bus are a common design. This design using symmetric multiprocessing (SMP) effectively doubles the computational power and input/output (IO) resources. However, routing out all available input/output (IO) ports becomes increasingly difficult and poses some significant challenges specifically with respect to signal integrity (SI). Of particular relevance are the electromagnetic interferences between different signal traces and the loss of signal with increasing trace length.
Furthermore, the transition to higher data rate signaling increases the problems with signal integrity. Some of these issues can be addressed by using better board substrates with a lower loss tangent and more sophisticated trace routing including, but not limited to, signal skew matching and shielding. However, in view of the above, it is clear that new design strategies are needed to reduce the overall trace length in order to improve signal integrity while saving board manufacturing cost.

Modular motherboard for a computer system and method thereof


A method and apparatus are provided for updating software one or more control devices in a data center. According to the method and apparatus a data center is outfitted with a plurality of control devices responsible for controlling the operation of a data center component. An update server is configured to update software running one of the plurality of control devices whenever software running on another one of the plurality of control devices is updated.

Automatic control devices are used to control the operation of various machines and devices in a data center. In operation, some control devices output control signals, causing motors of controlled devices to turn, valves to open, or circuit boards to power up. In some instances, the system boards of the control devices may lack sufficient facilities for generating the control signals on their own. For this reason, they may use another type of control device, an interface device, to generate and receive signals on their behalf. By using specialized circuitry, the interface devices may generate signals having a specified voltage, current, frequency, or another characteristic, which other control devices cannot by themselves produce.
In general, each interface device may perform at least one of two functions. The interface device may relay control signals whose values are determined by other control devices, and also the interface device may determine the values of control signals by itself. Both functions may be implemented in software. In addition, the functions of control devices that feed control signals to the interface devices may also be implemented in software.
When software running on a control device is updated, special care needs to be taken to prevent the introduction of software bugs. Software updates, over the course of their development, may be tested for compliance with only some of many possible software versions that are running on interface devices (and other control devices) in a data center. Installing, on a control device, a software update that has not been tested for compliance with software running on an interface device connected to the control device may interfere with the proper operation of both the control device and the interface device. The interference may be due software bugs in either one of the two devices. A consequence of the interference may be a loss of control over a data center component that is controlled using the two devices.

Updating control devices in a data center


A plate-tube type heat exchanger not requiring maintenance is described, comprising: a plate with a plurality of channels running parallel along thereof; and, a plurality of tubes housed and secured to said channels, thus forming a circuit for the circulation of a heating fluid, a cooling fluid or a means of heating; the plate includes integrally attachment means associated to each channel, which in their closed position, cover along with its corresponding channel, almost the entire tube external perimeter housing in said channel, thereby securing each of the tubes to the whole plate, without the use of welding and a large contact surface is achieved for the heat conduction between the plate and each one of the tubes.

Generally, plate-tube type heat exchangers are comprised by a plurality of tubes and plates, which are bonded to each other by mechanical fastening or tack welded in order to shape the exchanger structure.
Particularly, such heat exchangers are used as condenser and evaporator in domestic and commercial refrigeration systems, they can also be found on water heaters by means of solar energy, air heaters including inside the tubes, an electric resistance, natural convection static condensers, forced air condensers, natural convection static evaporators and forced air evaporators.
In spite of the widely spread use of these equipments, they have been observed as presenting some drawbacks. In first instance, it may be said that manufacturing process of these equipments is quite complex, since upon being comprised of multiple components, steps to assemble them are burdensome, such as the bonding step between tubes and plates via tack welding, in which it is necessary to bond the tubes one by one to the plates.
Likewise, such a traditional method of binding tubes and plates is not that suitable for the equipments previously mentioned to achieve a efficient heat transfer between the environment and the heating or refrigeration fluid which is inside the tubes, particularly, because the contact surface between tubes and plates is significantly reduced, as may be seen in FIG. 1, showing a cross sectional cut of a "half coverage" type assembly used in plate-tube type heat exchangers of the prior art. In such an assembly, a tube is housed in a plate channel, remaining fixed and contacting directly therewith only through a welding point.
A variant of this traditional method of assembly by welding can be appreciated in FIG. 2, (total coverage), wherein a pair of plates similar to those in FIG. 1 are welded to each other by welding tacks, enclosing the tube between the channel thereof. This variant is neither efficient, since most of times the tube does not fit correctly the space formed by the plate channels, thus having a little direct contact between plates and tube for heat conduction.
On the other hand, there is an additional problem related to maintenance and cleaning of these equipments, specially forced air condensers which include fins, such as those used in domestic or commercial refrigeration systems. In said condensers, spacing between fins is significantly reduced, generally between 2 to 3 mm, which favors adhesion and accumulation of dust, grime and crap therebetween. Said accumulation becomes so important that in many cases, the air passage through fins may be obstructed, thereby causing reduction in condenser's heat exchange ability with the environment and consequently, the refrigeration system stops functioning and cooling properly, affecting other elements of the refrigeration system. Additionally, cleaning said dust or grime adhered to the fins is made difficult due to the space quite reduced existing between fins.
Thus, in the state of the art, it may be found systems which intent to reduce on one hand, the assembly steps of these heat exchangers, such is the case of evaporator described in U.S. Pat. No. 2,212,912, which is formed from an extruded sheet integrally including tubes and fins. However, in order to give the evaporator a final shape, the tubes included in said plates need to be welded to a header or headers using several accessories. Similarly, when it is desired to form condensers with a higher capacity, it is necessary to weld bonding two extruded sheets or to change the size of extrusion die used to manufacture said sheets, thus increasing manufacturing costs.
On the other hand, the European Patent No. 0157370, is directed to a panel for an evaporator or condenser heat exchange, said panel is also formed from an extruded sheet which includes a plurality of oval-shape grooves in cross section; inserting a tube in each of said grooves, said tube undergoes a plastic deformation at its circular wall to refill and to fit the oval contour of the groove walls, thus remaining fixed inside, reason why it is not necessary to use welding in order to bind tubes to the extruded sheet. However, when it is desired to bind two panels to form a larger condenser, this document only provides the use of a piping to connect both panels, without mentioning the existence of a direct and firm bonding therebetween; this lack does not allow to manipulate such panels together so as to form different condenser or evaporator configurations and arrangements.
Finally, both documents from the prior art, do not consider among its objects to form a heat exchanger, on which said problems regarding adhesion, accumulation, and dust and grime cleaning between its components are minimized, which as mentioned above, decrease the capacity of equipment performance.
An additional prior art document is U.S. Pat. No. 2,732,615, related to a method for securing a tube to a metal plate, whereby the plate is deformed to form a channel, and further to the placement of a tube in said channel, pressing the plate against the tube in order to deform it and secure it. This document does not show how to join two or more plates in order to form a tridimensional heat exchanger, neither it indicates the employment of alternative extruded plates.
Accordingly, it has been sought to suppress the drawbacks of the tube-plate-type heat exchangers from the current art, and to provide a tube-plate-type heat exchanger not requiring maintenance, of a very simple and convenient construction, which allows to reduce the number of components and work used during its manufactures, thus eliminating the use of welding to join the tubes and plates, or to join two or more plates to each other, in which cleaning of dust and grime that may be adhered and accumulated between its components is easy.


The invention provides a method for forming a plurality of single silicon crystals over a substrate. The method forms a plurality of nucleation sites over the substrate. An amorphous silicon layer is formed over the substrate covering the plurality of silicon nucleation sites. The amorphous silicon layer is melted by using a laser beam and then crystallized to form the plurality of single silicon crystals. Each of the plurality of single silicon crystals correspond to one of the plurality of nucleation sites.

1. Field of the Invention
This invention relates to a method for forming single silicon crystals by laser crystallization.
2. Description of Related Art
As the demand for higher performance two-dimensional arrays used in devices such as displays and scanners increases, the requirements for higher performance thin film transistors (TFTs) to integrate high speed electronic circuits with the two-dimensional arrays also increase. However, because conventional TFTs are manufactured using polycrystalline silicon thin films having small grain sizes, the performance of conventional TFTs is limited by undesirable low field-effect mobilities inherent in these polycrystalline silicon thin films.
Field-effect mobilities are reduced by grain boundaries. Thus, if the polycrystalline silicon film contains large grain sizes, then the number of grain boundaries per unit area would be reduced and the field-effect mobility would be improved. Accordingly, many efforts have been advanced to increase field-effect mobilities by producing polycrystalline silicon thin films having large crystal grain sizes so that greater performance polycrystalline silicon TFTs may be obtained.
Prior efforts to increase polycrystalline silicon grain sizes have relied on solid phase crystallization in which an entire assembly (i.e., the substrate and deposited films) is heated at high temperatures for many hours to encourage large crystal growth. However, solid phase crystallization has several drawbacks: 1) throughput is low because a large amount of time is required to form large crystal grains; and 2) glass substrates are subjected to high temperatures causing many adverse effects such as warping and bending of the glass substrates.
Besides having small grain sizes, the polycrystalline silicon films formed by prior processes also have a problem of varying grain densities. Since polycrystalline silicon grains are formed randomly, there is no control of the number of grains formed or the distribution of grain sizes. In fact, many polycrystalline silicon films have greatly varying grain sizes. The performance of TFTs formed in these polycrystalline silicon films strongly depends on the locations of the devices since grain size and density vary greatly over the substrate area. Thus, dependable electronic circuitry cannot be realized even though the average polycrystalline silicon grain size is increased.

Method for forming single silicon crystals using nucleation sites


In a fast scanning technique in which the repeat time TR is less than the T2 relaxation time, a first generation component (34), a second generation component (52), and a third generation component (62) are each phase encoded by a phase encode gradient (36). The persisting second and third generation components are encoded with the sum of the phases with which they have been encoded in the present and prior repetitions. A composite data line is sampled during each echo and includes a first component (44), a second component (54), and a third component (64), each component having an independent phase encoding. The data lines are each stored in a first data set memory (80) in accordance with the phase encoding of the first generation component, in a second data set memory (82) in accordance with the phase encoding of the second component and in a third data set memory means (84) in accordance with the phase encoding of the third generation component. Each of these data sets is filtered (110), transformed (112) into a magnitude image (114) and phase image (116). The magnitude and phase images are filtered (120, 122) and reverse transformed (126) back into a filtered data set (128) and weighted (130) to form an estimate of one component of the other data sets. The estimate is subtracted (138, 140) from the other data sets. This process is iteratively repeated until each data set contains substantially only the data of one component. Each data set is then reconstructed (98) into a separate image representation.

The present invention relates to fast scanning magnetic resonance imaging. It finds particular application in conjunction with medical diagnostic imaging procedures in which data is concurrently acquired for multiple images with different T1/T2 weightings and will be described with particular reference thereto. However, it is to be appreciated, that the invention will also find application in conjunction with fast scanning sequences for generating a single image and for non-medical applications.
In many magnetic resonance imaging sequences, the repeat time TR is selected to be substantially longer than the T2 relaxation time of the material being imaged. This permits the transverse magnetization which is excited in each repetition of the sequence to die out before the next repetition, of course, if the repeat time is shortened, then the time required to collect a full set of data is shortened proportionately. However, when the repeat time is shortened to be comparable to or less than the T2 relaxation time, transverse magnetization excited in one repetition persists or carries over into the next repetition.
Various fast scanning sequences have been developed in which the repetition time TR is less than the T2 relaxation time of the material being imaged. In each repetition of the sequence, there is a freshly excited or first generation resonance signal component and older persisting (second and higher generation) residual magnetization signal components which carry over from the preceding one or more repetitions. When the freshly excited and persisting residual resonance magnetization signal components are allowed to coincide, the resultant images are difficult to interpret. The different signal components have had different amounts of time (TE) in which the signal may decay, and thus one cannot expect to see the typical contrast associated with any one TE. Worse yet, the residual signal components have different histories of phase evolution than the freshly excited component. In particular, the different histories involve different phase accumulation, and so the residual components may not reconstruct properly at all, or they may reconstruct with minor phase errors causing them in some places to add constructively to the main component, and in other places to add destructively.
One can run a generic field echo scan with a very short TR and with a small flip angle. The freshly excited and residual signals from several repetitions can be permitted to overlap without expressly worrying about alignment in the time of the echoes, refocusing phase echoes, or inducing dephasing. In this manner, the freshly excited and residual magnetization signals add together to produce a stronger resonance signal for imaging. However, this technique is prone to serious banding artifacts and interference patterns. Because the single resultant image is actually a complicated superposition of images, its contrast is hard to interpret.
In one technique for improving the resultant images, untwisting or phase decoding gradients are applied at the end of each repetition to erase the phase history of the residual components. In this manner, the residual magnetization and the freshly excited magnetization signal components have the same phase encoding. When the residual and freshly excited magnetization signal components are caused to refocus concurrently into echoes, their contributions add improving the signal-to-noise ratio. This enables a steady-state to be reached in which the magnetization in each repetition has the same ratio of freshly excited to residual signal, one of the drawbacks to this technique is that it is prone to banding artifacts and has a complicated contrast. A source of the banding is phase dispersion from static field inhomogeneities, chemical shift, motion, or the like, which are phase-producing mechanisms not compensated for by the phase untwisting gradient waveforms.
Another approach is to spoil the residual signal from the preceding cycles. A constant gradient section is used in each repetition that is not refocused. This spoils the residual signal components and averages the phase dispersion within each voxel. The image intensity of a steady-state type scan varies as a function of the evolving phase dispersion. However, this evolving dispersion effect is reduced or eliminated by causing each voxel to contain one complete cycle of phase variation or an integer number of phase wraps. Leaving a constant amount of gradient without rephasing in each repetition interval insures that all voxels exhibit a comparable, average phase dispersion. However, this technique may still yield some banding artifacts and striping. It does not make use of all available signal. Rather, the signal-to-noise of the total scan is lower than other techniques described above.
Another technique is to spoil the residual magnetization signal components with varying gradients. When the amplitude of the spoiling gradient is altered from repetition to repetition, a spoiling effect is achieved under conditions where constant amplitude spoiler gradients would just cancel out. The spoiler gradients are applied along coherency pathways with RF spin echoes or with RF stimulated echoes. The spoiler gradients either increase progressively in steps with each repetition or alternate polarity. However, these techniques do not make use of the total available signal. Stepping the spoilers over long ranges which do not repeat is impractical, especially with shorter repetitions. Often the hardware to support large gradients is not available. Stepping spoiler gradients through short patterns breaks up the shorter coherence pathways but allows longer RF echoes to be refocused. Using large sections of gradients which alter significantly from repetition to repetition may induce detrimental gradient eddy current effects which distort images and destroy steady-state effects.
There is a class of techniques in which the RF pulse is modified from repetition to repetition. The phase modification is used in one of several ways to reduce artifacts. For example, the phase of the RF pulse is indexed in steps which vary throughout the duration of the scan. In another technique, two scans are taken. In one scan, the RF phase is held constant and in the other the RF phase is alternated. The images obtained from two scans are selectively combined such that regions of one image with banding artifacts are replaced with artifact-free portions of the other image. In another related technique, the RF transmit phases are stepped and different transforms are performed to separate the various echoes. The other RF modified techniques also have the disadvantage of requiring longer scan times, or the disadvantage of greatly reducing resolution to achieve the same short total scan time. In the first technique in which the phase step varies, less than all of the total available signal strength is used. Although this technique reduces artifacts, residual artifacts are still found.
In other techniques, the residual and freshly excited signal components are caused to generate echoes which are offset in time. In this manner, the echoes from each component occur one after the other and are acquired in succession. This enables the data from each echo to be handled separately to generate multiple images or a single image which is free of residual magnetization contribution. However, because numerous echoes occur in a very short interval, the sampling time accorded for each is relatively small. This small sampling window decreases the signal-to-noise. Moreover, for a given resolution and a given field of view, more total gradients are required (particularly the read gradient) than in the other methods discussed above. In order to be practiced on currently available scanners, it is normally necessary to compromise either the repeat time, the resolution, or the field of view.
The present invention contemplates a new fast scanning technique which overcomes the above-referenced problems and others while generating one or more artifact reduced images.

Concurrent generation of multiple images in fast (TR<T2) scanning sequences


In a centrifugal rotor having inlet channels (23) situated between a stack of axially separated conical separation discs (13) and the rotor end wall (10), towards which the separation discs turn their apex ends, there is formed a counter pressure chamber (22) in an area where the inlet channels (23) communicate with one end of several distribution channels (21) extending through the stack of separation discs. The counter pressure chamber (22) is free of entrainment members, so that liquid leaving the inlet channels (23) is allowed to rotate in the counter pressure chamber at a smaller angular speed than the rotor. Further, the counter pressure chamber (22), communicates with a radially outer portion of the rotor separation chamber (9) through a sludge passage (34), which opens in the separation chamber at a level radially outside the stack of separation discs. The outlet channels (27) for separated liquid extend towards the rotor axis (R) from an area of the separation chamber which is situated in the vicinity of said rotor end wall (10) at a level in the separation chamber radially outside the stack of separation discs (13).

A starting point for the invention has been a centrifugal separator, which has a rotor for rotation around a central axis extending through the rotor and in which
a rotor body, which comprises a first end wall and a second end wall arranged axially one on each side of a separation chamber surrounding the rotor axis, forms a central inlet for said liquid containing the suspended light and heavy particles, a central first outlet through said first end wall for liquid having been freed from light and heavy particles, and a central second outlet for a liquid light phase containing separated light particles, PA1 a stack of conical separation discs is so arranged in the separation chamber that the separation discs, which have base portions and apex portions and which are arranged with interspaces between themselves, are placed coaxially with the rotor and have their apex portions facing said first end wall, PA1 each one of several inlet channels, which are distributed around the central axis and which connect the central inlet of the rotor body with the separation chamber, has an inclination relative to the central axis in the same direction as a generatrix of each one of said conical separation discs, PA1 the separation discs have several series of aligned holes forming several parallel distribution channels through said stack, which communicate with the interspaces between the separation discs and at their ends closest to said first end wall communicate with said inlet channels, PA1 each one of a number of outlet channels, which are distributed around the rotor axis and intended for liquid having been freed from light and heavy particles, has a channel opening situated in the separation chamber in the vicinity of said first end wall at a level radially outside the stack of separation discs and extends from this channel opening towards the central axis of the rotor, and PA1 the rotor is substantially free of entrainment members in a flow space in the separation chamber situated radially outside and surrounding the stack of separation discs, so that liquid leaving the interspaces between the separation discs is allowed to rotate at an angular speed smaller than that of the rotor body while it flows towards said channel openings. PA1 that said inlet channels open in a counter pressure chamber, which extends around the rotor axis and is delimited axially by chamber walls which are substantially free of rotational entraining members, so that liquid is allowed to rotate in the counter pressure chamber at an angular speed smaller than that of the rotor body, PA1 that the counter pressure chamber has a first portion, which communicates with said distribution channels, and a second portion which is situated radially outside said first portion and communicates with at least one sludge passage, and PA1 that the sludge passage opens in the separation chamber at a level radially outside the stack of separation discs.
A centrifugal separator of this kind, known for instance from SE-19 666 and SE-21 885 (both granted in 1904), has certain advantages over other centrifugal separators. One advantage lies in the fact that liquid to be treated in the centrifugal separator is introduced into the rotor separation chamber at the rotor end wall, towards which the separation discs turn their apex portions. This makes possible an effective use, from a separation point of view, of said inlet channels which extend between the central inlet of the rotor and the so called distribution channels in the stack of separation discs. Thus, thanks to the inclination of these inlet channels in relation to the rotor axis, the pre-separation of liquid obtained in the inlet channels may be used to a maximum, i.e. the result of this pre-separation is not spoiled by an undesired cross flow of the part flows of liquids, which are obtained through the pre-separation, when the liquid is conducted further on into said distribution channels. Such cross flow would be obtained, however, if the liquid would be conducted into the distribution channels at the opposite end of the separation disc stack after having flowed through corresponding inlet channels having the same inclination relative to the central axis in this part of the rotor.
Another advantage of a centrifugal separator of the defined kind is that liquid being conducted into the separation chamber in the described manner can, advantageously, be introduced into the rotor at the rotor body end wall at which said inlet channels are situated. Thus, the liquid need not be conducted axially through the whole of the rotor before it enters the separation chamber, which today most often occurs in centrifugal rotors having frusto conical separation discs. This is advantageous particularly in connection with rotors having relatively small dimensions and having both of their respective end walls kept axially together by means of force absorbing members arranged centrally in the rotor.

Centrifugal separator to free a liquid from bath lighter particles and heavier particles


The onset of an excessive slip condition in a slip controller is determined so that it is adaptable to the actual drive torque conditions between the driven wheel and the road surface so as to achieve the desired acceleration or braking characteristics for all vehicle driving conditions including while the vehicle is traveling on a curved road surface. At low vehicle speeds, slip control is enabled when the value of a predetermined function of the difference in speeds of the driven and undriven wheels exceeds a threshold that is a function of the vehicle turn radius and at high vehicle speeds when the value of a predetermined function of a wheel slip ratio exceeds the threshold that is a function of the vehicle turn radius. The vehicle speed below which slip control is enabled based on a wheel speed function and above which traction control is enabled based on the wheel slip function increases with an increasing vehicle steering angle.

This invention relates to a method of sensing an excessive slip condition for a vehicle slip control system.
When a torque is applied to a vehicle wheel for braking or driving the wheel, a force is generated between the wheel and the road surface tending to decelerate or accelerate the vehicle. This force is dependent upon various parameters, including the road surface conditions and the amount of slip between the wheel and the road surface. As the torque input to the wheel is increased, the force between the tire and the road surface increases as wheel slip increases, until a critical slip value is surpassed. When the slip exceeds this critical slip value, the force between the wheel and the road surface decreases. Further, as wheel slip increases, the lateral forces acting on the slipping wheel decrease.
Various methods have been proposed for preventing this excessive slip condition of the wheels of a vehicle. In the case of acceleration slip, these methods include a traction controller that adjusts engine torque and/or the application of the brakes of the driven wheels when an excessive slip condition is sensed. In the case of vehicle braking, a wheel-lock controller limits brake pressure when an excessive slip condition is sensed. Whatever method is selected for controlling wheel slip, it is an objective of these systems to (a) maximize the longitudinal driving or braking forces and (b) to continuously maintain lateral
In order to achieve the foregoing objectives, it is desirable to control entry into traction or anti-lock braking control so as to minimize premature entry to thereby achieve a maximum transfer of force between the wheels and the road surface while at the same time maintaining lateral stability.

Method of sensing excessive slip in a wheel slip control system


Provided is a foot structure for a humanoid robot capable of effectively keeping its balance in a pause state or action. The foot structure includes a support; a plurality of lower structures having an upper member connected to a bottom of the support; a plurality of lower members having a plurality of independent portions each movably connected to the upper member; and a revolute joint for coupling the upper member and the lower member. Since a contact between the foot structure and the floor is smoothly made, a shock is prevented from being transferred to a body of the humanoid robot. Also, a vibration generated when the humanoid robot steps on the floor is eliminated, so that the humanoid robot can pose a stable and smooth gate.

1. Field of the Invention
The present invention relates to a humanoid robot, and more particularly, to a foot structure for a humanoid robot capable of effectively keeping its balance in a pause state and/or action state.
2. Description of the Related Art
Robots are generally utilized for factory automation and play an important role in non-human environments. Recently, humanoid robot systems are being actively developed because robots capable of performing in a human environment such as offices, homes, or hospitals are desired. Accordingly, some humanoid robots have been developed.
One of most important conditions of a humanoid robot is to guarantee an effective interaction between a foot of the robot and the ground. If there is no effective interaction between the foot of the robot and the ground, a shock is generated when a heel of the robot's foot touches on the ground, and is then transferred to the robot's foot. Furthermore, the shock is transferred to the robot's body through an ankle joint. Due to such a shock, the dynamic equilibrium of the robot may be disturbed and an unstable gait of the robot may be caused. In addition, a vibration of the foot resulted from the shock is transferred to the body of the robot, thereby lowering a control stability of the robot.
Another problem resulted from the unstable interaction between the robot's foot and the ground occurs when the robot passes an area where small obstacles exist on the ground or a surface of the ground is not flat, even though the robot may use a vision system for assessing the surroundings. In this case, the robot's foot does not adequately step on the ground, which deteriorates the stability and spontaneity of the gait of the robot.
In order to solve the above problems, several robot's foot mechanisms capable of absorbing a shock during walking have been proposed. Among them are the foot structures disclosed in the article "The development of Honda humanoid robot" by K. Hirai et al., Proceedings of the 1998 IEEE International Conference on Robotics & Automation, Leuven, Belgium, May 1998, and U.S. Pat. No. 6,377,014, "Legged walking robot" issued to Gomi et al., on Jun. 23, 2002.
FIG. 1 is a cross-sectional view illustrating a structure of a conventional robot foot disclosed by K. Hirai et al.
Referring to FIG. 1, a foot 10 includes a sole 14 made of rubber and a bushing 12 having a guide shape and made of rubber, thereby constructing a mechanism capable of absorbing a shock. The foot 10 of the robot is elastically deformed in a vertical direction by a ground force applied from the sole 14. With the above construction, the transfer of an impact load is reduced, since the foot serves mechanically as a low-pass filter to prevent the vibration of a leg so that the leg can be smoothly controlled.
However, the foot 10 does not provide a stable walking mechanism. For this, the rubber used for the sole 14 and the bushing 12 has to have high elasticity in order to secure the stability of the upper portion of the robot relative to the sole 14 so that a tight contact between the sole 14 and the ground can be achieved.
Consequently, the total stiffness of the foot is increased and becomes approximately a constant regardless of a value of the ground force. Therefore, this type of shock-absorbing apparatus has a disadvantage in that it cannot effectively attenuate the vibration generated after a shock is applied to the heel of the robot.
In order to overcome the above problem, U.S. Pat. No. 6,377,014 teaches a robot foot having a sole consisting of a first elastic portion and a second elastic portion, and the second elastic portion having a heel portion consisting of a flat central portion of a relatively thin thickness and a plurality of projections of a relatively thick thickness which are spaced apart from each other at regular intervals.
Meanwhile, a structure of a humanoid robot employing a six-axis force sensor that makes the robot walk stably on a rough and flat terrain is disclosed in the article "Design of advanced leg module for humanoid robotics project of METI," by Kenji Kaneko et al., Proceedings of the 2002 IEEE International Conference on Robotics & Automation, Washington, D.C., May 2002.
FIG. 2 is an explanatory view depicting a foot structure of the conventional robot of using a six-axis force sensor.
As shown in FIG. 2, a foot 20 of the robot includes a six-axis force sensor 22, a plurality of rubber bushes 24, and a sole plate 26. It is very important to control a torque of the sole in order to make the robot walk stably on rough terrain. Since the plurality of bushes 24 serve as a compliance element with a roll axis and a pitch axis, the rotational deformation of the plurality of bushes 24 is controlled by the 6-axis force sensor 22, thereby controlling the torque applied to the sole of the robot.
In addition, WAF-2 (Waseda Anthropomorphic Foot No. 2), an advanced foot structure for a humanoid robot, and a controlling system for the WAF-2 are disclosed in the article "Experimental development of a foot mechanism with shock absorbing material for acquisition of landing surface position information and stabilization of dynamic biped walking," by Jinichi Yamaguchi et al., IEEE International Conference on Robotics & Automation, pp 2892-2899 (1995).
FIG. 3A is a view depicting a structure 30 of WAF-2.
As shown in FIG. 3A, the WAF-2 structure 30 includes an upper foot plate 40, four potentiometers 36 placed on the upper foot plate 40, four wires 38 penetrating the upper foot plate 40, a plurality of upper stoppers 50 placed under the upper foot plate 40, a shock-absorbing member 44 positioned under the upper foot plate 40, a first acrylic plate 42 positioned between the upper foot plate 40 and the shock-absorbing member 44, a lower foot plate 62, a second acrylic plate 46 placed between the lower foot plate 62 and the shock-absorbing member 44, a plurality of lower stoppers 60 placed on the lower foot plate 62, and a plurality of spikes 64 formed under the lower foot plate 62.
FIG. 3B is a perspective view depicting one of the plurality of upper stoppers 50 placed under the upper foot plate 40 in FIG. 3A.
As shown in FIG. 3B, the upper stopper 50 consists of a duralumin 52, a urethane rubber 54, a Teflon resin 56, and a silicon foam 58.
As shown in FIGS. 3A and 3B, the WAF-2 structure 30 has a passive shock-absorbing mechanism achieved by the shock-absorbing member 44 placed between the upper foot plate 40 and the lower foot plate 62 and the plurality of upper stoppers 50 placed under the upper foot plate 40. In the case of a ground force having a nonlinear characteristic where the foot stiffness is gently increases with the ground force, such a structure can provide a shock-absorbing mechanism. In addition, this structure provides a stabilizing function by the upper stoppers 50 and the lower stoppers 60 placed on the spikes 64, and the upper foot plate 40 and the lower foot plate 62, respectively.
A two-legged robot using this structure can easily operate on a surface having variations of a few millimeters in a vertical or horizontal direction or at an inclination angle of about 1°.
However, the humanoid robots employing the WAF-2 or WAF-3 structure have several drawbacks.
The humanoid robot has a nonlinear stiffness characteristic similar to a human being only at a nominal load corresponding to a robot having a weight of about 110 kg and within a range of 6 mm. In other words, the maximum stiffness of the foot is equal to 91.7 N/mm under a restricted condition. If the maximum ground force is above the value, the upper foot plate is completely contacted with the lower foot plate. Thus, an average stiffness of the foot is determined by a metal portion having high stiffness and low damping.
In addition, since the WAF-2 or WAF-3 structure utilizes a shock-absorbing material, such as a yellow memory foam M-36, the elastic characteristic varies. A heater is mounted in the foot structure to maintain the temperature in about 40° C., so as to prevent variations of the elastic characteristic. Thus, the foot structure is heavy and very complicated.
Finally, since the WAF-2 or WAF-3 structure has no toe joints, the robot cannot secure a tight contact between the ground and the foot in a push-off motion during walking. Therefore, the robot cannot secure a sufficient propelling force required for quick walk, run, carrying a load, or the like.

Foot structure for humanoid robot and robot with the same


A fluid level sensor for determining a fluid level within a container, includes a transducer for generating sonic or ultrasonic waves and a wave guide. The wave guide has a first end operatively coupled to the transducer and a second end for immersion into the fluid, the second end spaced a predetermined distance from the first end, wherein a gap is formed between the first end and the second end. The sensor can be used to measure a fluid level using both an impedance mismatch signal and a fluid conductance signal.

Conventional non-continuous fluid level sensors used in aircraft fuel systems typically are based on two-wire thermistors or float switches. Conventional thermistor-type aircraft fuel level sensors monitor the temperature change of the sensor as power is applied to the sensor. If the sensor is immersed in the fuel, the temperature will not change significantly, as the fuel acts as a heat sink. However, if the sensor is not immersed in the fuel, the power applied to the thermistor causes the sensor temperature to rise, thereby signaling that the sensor is not immersed in the fuel.
Recently, the Federal Aviation Administration has enacted Special Federal Aviation Regulation Number 88 (SFAR 88). SFAR 88 requires certain Type Certificate and Supplemental Type Certificate (STC) holders to conduct a system safety review of fuel tank systems on transport category airplanes. The above described thermistor fuel level sensor is not compatible with SFAR 88.
Float switches are another type of conventional non-continuous fluid level sensor. A float switch relies upon a magnet in a float that rides along a vertical rod and activates a reed switch in the rod at the desired fluid level (set point). This type of sensor is based upon mechanical motion and is prone to reliability problems and limited operating life.
Fluid level sensors have been used for other level sensing applications. However, these sensors typically are multi-transducer systems that utilize three or four wire configurations, which are not compatible with existing two-wire level sensors used in aircraft fuel tanks.
Further, conventional single-transducer ultrasonic sensors usually depend on a minimum propagation time of the ultrasonic wave in the fluid, resulting in a relatively long sensor and large minimum sensing height (e.g., around two to four inches above the bottom of a liquid container or tank). Such sensors rely on an ultrasonic wave traveling in a fluid reflecting off a target surface. Thus, changes in the target surface (e.g., due to contamination, degradation, etc.) can degrade sensor performance.
By way of further example, U.S. Pat. No. 4,320,659 to Lynnworth discloses an ultrasonic sensor that generates vertically polarized shear-mode (SV) ultrasonic waves, which interact with surrounding fluids through the length of the ultrasonic propagation path. The sensor relies on the SV waves "leaking" into the surrounding fluid.
U.S. Pat. No. 4,325,255 to Howard discloses a two-transducer system (e.g., one transducer for transmitting and the other transducer for receiving the ultrasonic wave) mounted in a sensor head and using a closed loop servo system for measurements.
U.S. Pat. No. 4,614,115 to Pelletier discloses a sensor based primarily on the use of non-longitudinal waves (shear waves) generating multiple (secondary) reflections off the lateral walls of a sensing rod immersed in material to be tested. These secondary waves propagate outside of the lateral walls of the sensor rod and interact with the surrounding medium. Pelletier is primarily concerned with the change in amplitude of the non-longitudinal secondary reflections over time (as a measure of change in properties of the surrounding system).
U.S. Pat. No. 4,890,490 to Telford uses Lamb waves (flexural waves) propagating in a thin metal plate (waveguide). These relatively slow, low frequency Lamb waves are designed to travel relatively long distances (tens of meters) in their sheet metal wave guide and exhibit a change in amplitude at discontinuities when fluid is present/absent.


A contouring broom assembly is provided for following contours of a surface. The assembly includes an angling contour mechanism (600) for allowing a cylindrical side broom (140) to angle relative to horizontal and an elevating contour mechanism (610) for allowing the cylindrical side broom to rise and fall in a substantially linear fashion. The mechanisms (600 and 610) operate separately to allow for independent elevating and angling and each of the mechanisms can be operated without active user involvement, for example, responsive to pressure exerted on the cylindrical side broom by the surface due to traversing a contour. A scrubber squeegee assembly (620) formed from discrete units (622, 624 and 626) is also disclosed. The assembly (620) allows for independent selection of the materials or characteristics of each unit (622, 624 or 626).

The typical industrial sweeper is a motor driven vehicle that employs a rotating broom to lift debris from a surface such as a floor. The sweeper also typically includes a vacuum system that establishes a directional airstream adjacent to the broom to pull the debris that has been lifted by the broom into a hopper where the heavier debris precipitates out of the airstream. The lighter debris is generally removed from the airstream by a filtering device.
Present sweepers primarily rely upon a cylindrical broom, which rotates about an axis that is parallel to the floor surface, to lift debris for deposit in the hopper. The cylindrical broom is generally located between the front and rear wheels and laterally extends no further than the edge of the sweeper body. Many sweepers also employ a disk side broom that rotates about a vertical axis relative to the floor surface to move the debris adjacent to the wall into the path of the cylindrical broom so that debris can be picked up by the cylindrical broom and deposited in the hopper. In some cases, the disk side broom is mounted on shock absorbers to accommodate bumps or other surface irregularities.
Another floor cleaning apparatus is a scrubber that mechanically scrubs a floor with a cleaning solution and then removes the cleaning solution from the floor. One type of scrubber is a motor driven vehicle that includes a device for spraying the floor surface with a soap or other cleaning solution, a pair of counter-rotating disk brushes for scrubbing the floor with the cleaning solution and producing a stream of wastewater in which the dirt is entrained, and a vacuum squeegee that is located behind the brushes and used to collect the wastewater for recycling.
The typical vacuum squeegee includes a mount with a front edge for receiving a front squeegee rubber that has a lower edge which is disposed slightly above the floor so that water can pass thereunder, a back edge for receiving a rear squeegee that has a lower edge that contacts or seals against the floor, and a vacuum port located between the front and back edges for removing the wastewater trapped between the front and rear squeegee rubbers. Typically, the mount is curved to direct the wastewater towards the vacuum port. Operation of the typical vacuum squeegee commences with wastewater passing under the front squeegee and then being retained between the front and rear squeegees, where it is vacuumed up through the vacuum port.

Floor cleaning apparatus with contouring broom