In an aspect of the present invention, a synchronizer ring, made of Fe-based sintered alloy, having an internal circumferential surface 101, is provided, the internal circumferential surface 101 being adapted to detachably engage in synchronized sliding with a rotating counterpart member thereof. At least the internal circumferential surface 101 is applied with aqueous vapor treatment to form iron oxide film thereon. In another aspect of the present invention, the iron oxide film has surface roughness not less than 20 .mu.mRz but not more than 55 .mu.mRz. In a further aspect of the present invention, the iron oxide film has a surface roughness not less than 25 .mu.mRz but not more than 35 .mu.mRz. In another aspect of the present invention, the iron oxide film has a thickness not less than 0.05 .mu.m but not more than 5 .mu.m. In a further aspect of the present invention, the major component of the iron oxide film is Fe.sub.3 O.sub.4. In a still further aspect of the present invention, at least the internal circumferential surface is applied with blasting treatment in addition to, and in combination with, the aqueous vapor treatment to form iron oxide film thereon.

Synchronizer rings have been conventionally used, for example, in synchromesh gear transmissions. Such synchronizer ring is a friction ring that engages in synchronized sliding with its rotating counterpart member, for example, a tapered cone, and disengages with the tapered cone. The ring plays an important role in synchronization of peripheral speeds of two mutually engaged gears. A synchronizer ring is known to have a structure, as shown in FIG. 1, where multiple gear teeth 100, adapted to engage with a counterpart member (not shown), are disposed, with a predetermined spacing, on the external-most circumference of a synchronizer ring, an internal circumferential surface 101, adapted to make contact with a tapered cone (not shown) when engaged, has longitudinal grooves 103 disposed thereon, and, when required, ring-shaped thin stripe grooves 102 formed thereon at a right angle with longitudinal grooves 103, and an external circumferential surface has keyways 104 disposed thereon for a synchrozizer key (not shown) to fit. Brass (a Cu--Zn alloy) has been typically used as material for forming a synchronizer ring.
With a synchronizer ring having chances to be formed in such shape, for example, as one described above, it is typically required that the ring has high mechanical strength and precision, and, besides, its internal circumferential surface, adapted to make contact with its counterpart member when engaged, has both excellent frictional characteristics and ample scuffing resistance. Especially, in the field of automotive transmissions, since not only secured functionality but also luxurious and sportive feeling are looked for in the operation as transmissions recently tend to be more luxurious and have higher performance, a synchronizer ring is desired that has further improved frictional characteristics and scuffing resistance.
Thus, various types of synchronizer rings are being studied that are attempted to have frictional characteristics and scuffing resistance improved, compared to conventional synchronizer rings made of brass (a Cu--Zn alloy).
Specifically, a synchronizer ring is known where a layer is formed on its internal circumferential surface by means of a flame-spraying method, the layer being prepared by uniformly mixing metal with ceramics and oxide, and fusing them together, as disclosed in JP-B 46-15043. Also, as a method available for manufacturing synchronizer rings, for example, a method for manufacturing a friction ring is known where a friction lining is formed on its internal circumferential surface by means of a flame-injecting method, the lining comprising sintered powder containing an 80 weight percent of metallic component powder and a 20 weight percent of non-metallic component powder, as disclosed in DE-PS 3,705,661.
Furthermore, a synchronizer ring is also being studied that comprises Fe-based sintered alloy containing bainite, pearlite and free Cu-phase in its base body.
However, the required frictional characteristics and scuffing resistance have not been accomplished yet with such conventional synchronizer rings as disclosed above, including the synchronizer rings having a layer formed on its internal circumferential surface by means of a flame-spraying method, the layer being prepared by uniformly mixing metal with ceramics and oxide, and fusing them together, and the synchronizer rings obtained by employing the method for manufacturing a friction ring where a friction lining is formed on its internal circumferential surface by means of a flame-injecting method, the lining comprising sintered powder containing an 80 weight percent of metallic component powder and a 20 weight percent of non-metallic component powder.
Other problems also having been experienced are such as insufficient strength due to insufficient dispersion of each metallic component, and unstable quality due to irregularity in the material of flame-sprayed coating. Furthermore, particles incompletely fused in the flame, or splashed or rebounded particles, are often entrained in the surface layer of flame-sprayed coating. Such entrained particles cause such problems that frictional characteristics tend to vary as time elapses due to the surface made rough by the entrained particles, and various portions in the transmission are caused to wear due to the entrained particles dropping off. On the other hand, grinding and cutting were being applied to the surface of the flame-sprayed coating for reducing the surface roughness of the coating. Disadvantageously, however, such grinding or cutting caused high working cost and material loss due to working margin.
In addition, the synchronizer ring comprising Fe-based 6 sintered alloy containing bainite, pearlite and free Cu-phase in its base body, as discussed above, has disadvantage in that sizing is difficult to work due to high hardness of HRB 90 caused by the contained bainite. Besides, coefficient of dynamic friction still has room for improvement.
The present invention has been made to solve the problems and overcome disadvantages, described above. Thus, an object of the present invention is to provide a synchronizer ring having excellent frictional characteristics and scuffing resistance and stable quality.


A side-view optical diode package is mounted on a printed circuit board with at least a solder bump. The side-view optical diode package includes a silicon substrate, a holding space, a bonding surface and a positioning structure. The silicon substrate has a first surface and a second surface. The holding space has a top opening in the first surface and a bottom for holding an optical diode thereon. The bonding surface is disposed at a lateral side of the silicon substrate and bonded onto the printed circuit board. The positioning structure has at least a solder-receiving portion beside the bonding surface and corresponding to the solder bump. The solder bump is molten during a soldering process and received in the solder-receiving portion, thereby facilitating positioning the silicon substrate on the printed circuit board.

Typically, two approaches are employed to mount a side-view optical diode package. The first approach involves the use of a printed circuit board (PCB) made of a composite material as a substrate. The side-view optical diode package is mounted on the printed circuit board and then encapsulated by a plastic molding operation. The second approach involves the use of a metallic lead frame as the substrate. The side-view optical diode package is mounted on the metallic frame and then encapsulated by an ejection molding operation or a plastic molding operation.
These two approaches, however, have some drawbacks. For example, the side-view optical diode package has poor temperature resistance and low heat-dissipating efficiency. In addition, during the side-view optical diode package is soldered onto the printed circuit board, some of the solder may overflow from the rear side of the silicon substrate to the lateral side and thus cause an leakage current. Due to the overflowing solder, the side-view optical diode package may fail to be securely attached onto the printed circuit board.
Therefore, there is a need of providing an improved side-view optical diode package so as to obviate the drawbacks encountered from the prior art.

Side-view optical diode package and fabricating process thereof


There is disclosed a system (45, 55) for controlling a high resolution color discrete level display device, wherein the display device can have multiple common lines (80, 81, 82) for each line of pixels. A frame buffer controller system (45) is disclosed which is adapted to utilise the multiple common lines in a number of different modes, producing a number of different output speeds for the display. Means (126, 127) are also disclosed for dithering the pixel data in accordance with the output modes. Further, the system is capable of displaying images, such as fonts or the like, at an increased resolution than that which would otherwise be possible.

In recent years, computer workstations, comprising a computational device, input devices and display devices, have become increasingly popular. In addition the demand for high powered workstations with high quality, high resolution displays has also increased dramatically.
Normally these demands are partially satisfied through the provision of Cathode Ray Tube (CRT) type devices capable of high resolution display. However, such devices tend to be extremely bulks, have an excessive weight and consume large amounts of power.
Recently, it has beer, proposed to provide a high resolution discrete level display having a large number of pixels with the pixels arranged in lines, and with each pixel having a plurality of independently setable areas with the overall pixel able to display a predetermined number of different discrete levels. The independently settable areas being controlled by a series of intersecting drive and common lines, are designed to cam predetermined voltages to each pixel of the display. Examples of these types of displays include liquid crystal displays, plasma displays and electro-luminescent displays.


A manhole system that includes a manhole cover and a frame with at least one locking device for maintaining the manhole cover in place on the frame. The locking device is selectively movable between locked and unlocked positions to selectively engage the cover to hold the cover in place on the frame. The locking device may be rotatable between “locked” and “unlocked” positions about an axis perpendicular to the plane of the cover. The locking device may includes a plurality of cam locks that engage the outer circumferential edge of the cover and are configured to increasingly clamp down the cover against the frame with increasing rotation from “unlocked” position to “locked” position. A plurality of locks can be arranged around frame to engage the cover at different locations.

The present invention relates to manhole closure assemblies and, more particularly, to manhole closure assemblies that can be maintained in a closed position.
Manholes are both well-known and widely utilized. Manholes are generally utilized as means for accessing an infrastructure, such as underground pipelines or cabling. Because manholes are essentially open holes into which an individual can fall, manhole covers are utilized to prevent entry into the manhole. A traditional manhole cover rests on a frame that is attached to the substructure above the infrastructure to be maintained. The cover rests on the frame and must be lifted and moved in order to gain access to the infrastructure beneath the manhole. Typically, manhole covers are formed of iron or other heavy metals and thus can weigh in excess of 100 pounds, creating a cover that is cumbersome to lift and otherwise maneuver. Although it can make manipulation of the cover difficult, the weight of the manhole cover is a benefit in that it helps to prevent the cover from being inadvertently removed from the frame, for example, by the force of passing vehicle traffic. It also helps to deter removal of the cover by unauthorized individuals.
It is known to lock a manhole cover to a surrounding frame. In many applications, the lock is, as far as is possible, tamperproof. The frequency with which the lock is used, i.e. locked and unlocked, may be high or low, depending on the circumstances. In many instances though a manhole cover will remain locked for a considerable period. The environmental conditions to which a manhole cover is exposed may also be severe and the cover may be subjected to a wide temperature range, the full effects of the weather e.g. rain and snow, traffic and the like. In an effort to effectuate a locking mechanism various padlock configurations, keyed locks or other similar locking devices have been utilized. The use of such locks has not gained popularity because they are cumbersome and difficult to utilize. They may also fail over long periods of exposure to environmental conditions.


A video processing method, a video processing device, and a storage medium are provided. The video processing method includes: determining target image frames corresponding to a dynamic special effect in a video and determining an attribute of a special effect element corresponding to the dynamic special effect in each of the target image frames and coordinates of the special effect element. The video processing method also includes: rendering the special effect element on a drawing interface based on the attribute and the coordinates of the special effect element; filling the target image frames into the drawing interface as a background and forming drawing interface frames with the dynamic special effect; and outputting the drawing interface frames corresponding to each of the target image frames.

With development of the Internet industry, especially mobile access to the Internet, sharing a video through the Internet is widely recognized as a new form of information exchange.
For example, in a mobile application, a user may record a video by using a mobile terminal such as a mobile phone. The user may share the video on a social network platform. Other users of the social network platform may view the video shared by the first user and provide comments, communicate, and share the video again by using an interactive function of the social network platform, sometimes with enhanced visual effects in the videos.
In the above example, when a user is recording a video or needs to share a video over the Internet, to emphasize or express a certain clip or a certain object in the video, the user usually needs to add a special effect to a corresponding clip or over the object to attract the attention of viewers. However, relevant technologies only support creating a simple graphic layer on each frame of image of a video, to achieve an effect of a graffiti, for example, in a video.
FIG. 1 is a schematic view of a display effect of making text graffiti on a frame of image in a video. The effect of making a graffiti by using letters "LALA" can be realized on one frame of image or at least two continuous frames of images in a video. However, when drawing a graphic layer on at least two frames of images in a video, a viewer may not know the clip or object of the video that a presenter intended to highlight if the viewer does not view the video from the beginning.

Method, device, and storage medium for displaying a dynamic special effect

TENCENT TECHNOLOGY (SHENZHEN) COMPANY LIMITED


A machine for surface preparation of a pipeline includes a vacuum shroud that encircles the pipeline. Three manifolds, each housing a plurality of ultra high pressure water nozzles, are mounted in the vacuum shroud at circumferentially spaced intervals. A carrier assembly advances the vacuum shroud along the pipeline at a rate that avoids contact between the water jets and uncoated pipe. The shroud also oscillates about a longitudinal axis of the pipeline so that a short extent of the pipeline is subjected to the force of the water for each oscillation. The vacuum in the shroud carries away all debris created by the coat-stripping process to a closed loop filtration and recycling system. The nozzles are mounted a constant stand-off distance from the pipeline to avoid creation of hot spots during the stripping process. All motions are electronically monitored and detection of any movement failure results in system shutdown.

1. Field of the Invention
This invention relates, generally, to pipeline surface preparation systems. More particularly, it relates to machines that travel along the length of a pipeline and remove coating therefrom by the application of water jets at ultra high pressure.
2. Description of the Related Art
The disclosure made in U.S. Pat. No. 5,238,331 to Chapman is believed to be relevant to the present invention because it describes a pipeline surface preparation system that is sufficiently light-in-weight to enable a team of two workers to place it into position around a pipeline in the absence of weight-lifting machinery. A frame surrounds the pipeline and the frame supports wheels that engage the surface of the pipeline and enable the pipeline surface preparation system to travel along the extent thereof. Moreover, the Chapman apparatus employs water jets to strip coating from a pipeline. Water nozzles are circumferentially spaced about the perimeter of the pipeline and limit switches are employed to cause the frame that carries the nozzles to reciprocate along a circumferential path of travel so that hoses connected to the apparatus are not wrapped around the pipeline as the apparatus advances along the length thereof.
The invention disclosed in the Chapman patent therefore solves several problems left unsolved by earlier advances in the field. Earlier devices are so heavy that a crane is needed to lower them into position atop a pipe. The weight of such devices causes the pipe to sag and thus limits the length of pipeline that can be excavated at any one time. When a crane drops one of the early heavy pipeline surface preparation systems onto a pipeline, catastrophic explosions may occur.
However, the art has not heretofore solved all of the outstanding problems associated with pipeline surface preparation systems. One of the outstanding, unsolved problems relates to handling of debris generated by the pipe coating removal process. Old coating commonly includes asbestos and other materials that require special handling. However, the pipeline surface preparation systems of the prior art do not adequately address the debris-handling problem. The conventional wisdom is that Visqueen® plastic or other suitable sheet material should be placed in overlying relation to the ground below the pipeline undergoing reconditioning. Asbestos and other debris is thus collected atop the plastic sheet material as the machine travels along the extent of the pipeline. Workers then carefully fold the plastic sheet material in an attempt to contain the hazardous materials deposited thereatop. The inadequacies of this well-known procedure are readily apparent. Asbestos in small pieces may easily float in the air beyond the reaches of the plastic sheet material and enter the lungs of workers in the vicinity. Asbestos may also enter the lungs of those who attempt to collect it by folding the plastic sheet material into a collection means.
A pipeline surface preparation system that prevents asbestos and other hazardous debris from escaping into the atmosphere and that minimizes total contaminated waste is clearly needed.
The earlier pipeline surface preparation systems also slip from time to time as they travel along a pipe because insufficient engagement is provided between the pipe surface and the rollers or wheels that rotatably engage said surface to cause the pipeline surface preparation system to travel along the pipe. When a pipeline surface preparation system slips, the pipeline can be damaged because the water jets have extended dwell time on the surface. It is very important that the extremely high pressure water jets that are used to strip away pipe coating be applied to the surface with controlled speed and rotation. When a pipeline surface preparation system carrier means slips, exposed pipe is subjected to the full power of the high pressure water jets for an extended time and pipeline damage may occur. A pipeline surface preparation system having improved traction is therefore needed.
A closely related problem is known in the industry as the "hot spots" problem. A "hot spot" is a location on a pipe surface that is subjected to more water pressure than other sections. A hot spot is created whenever a nozzle passes closer to the surface of the pipe in one location than it does in another. Thus, a hot spot may be created by slippage of the transported means as just mentioned, or it may be created by the inherent structural features of the pipeline surface preparation system. The prior art includes a nozzle assembly where a pair of nozzles is mounted to opposite ends of a rotating conduit that is straight in configuration. As a result, the nozzles pass closer to the surface of the pipe in some locations than others, giving rise to the problem of hot spots.
A need therefore exists for a structural design that eliminates hot spots by ensuring that all nozzles are spaced equally from the pipe surface at all times.
It is also important to monitor the air supply and the operation of all water-emitting nozzles because any failed movement will direct a high pressure water stream to a single spot and thereby damage the pipe. Automatic monitoring means should therefore be connected to the air supply, each nozzle, and other movable parts. A means should be provided for sending a "shut-down" signal to the ultra high pressure system when any required motion fails.
Yet another outstanding problem relates to the debris created by the stripping action of the water jets. The known pipeline surface preparation systems produce debris in large particle size. The art has addressed this problem by providing an external shredding means to reduce the debris particles to a more manageable size. The price of an external shredder increases the cost of the system, the time required to operate the external shredder decreases productivity, and the operation of the shredder could potentially add to environmental concerns with hazardous wastes.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the art how the known pipeline surface preparation systems could be improved.

This patent is subject to a terminal disclaimer.

Pipeline surface for inspection with debris collection


An interactive system for producing acceptable quality fluoroscopy images determines X-ray tube photon count and voltage while minimizing X-ray radiation dosage to a subject. Parameters of the subject and the type of image to be produced are provided to the system. X-ray tube voltage U and photon count Q are initialized at a fraction of conventional values for a portion of a subject to be imaged. An image is created and sectioned into rectangles. Rectangles having the greatest and least gradient values are used to determine variances indicating signal and noise power respectively. Images are produced and adjusted until the maximum transmitted power is reached, or the signal-to-noise ratio does not increase beyond a quality increment. The process is repeated to optimize X-ray tube voltage. The X-ray fluoroscopy procedure is then performed with the optimum X-ray tube photon count and the optimum X-ray tube voltage thereby reducing X-ray dosage. The optimization is repeated periodically to readjust the system.

1. Field of the Invention
This invention relates to fluoroscopic imaging and more specifically to reduction in patient X-ray dosage during imaging.
2. Description of Related Art
An X-ray procedure, known as fluoroscopy, creates a series of internal images of a subject. Conventional pulsed systems produce each image by transmitting an X-ray pulse or other ionizing radiation from one side of the subject and detecting the transmitted radiation or shadow at an opposite side of the subject. The intensity of an X-ray radiation beam can be described by the following equation: EQU J=.intg.J.sub.0 (E)e.sup.-.intg..mu.(x,E)dx dE
from p. 103 of Imaging Systems for Medical Diagnostics by Erich Krestel, Siemans Aktienggesellschaft, Berlin and Munich, where J.sub.0 is the intensity of an incident X-ray beam, E is the quantum energy of the X-ray photons, .mu.(x,E) is the linear attenuation constant which changes along a direction of the ray x, and changes with photon energy E.
Different tissues exhibit different linear attenuation as a function of X-ray photon energy E, thereby exhibiting different X-ray beam intensities J after transmission through the tissue. Adjusting the X-ray photon energy, therefore, can change the relative X-ray beam intensities as they pass through different tissue types, leading to increased contrast in an image.
The difference in intensity between the incident X-ray radiation, J.sub.0 and the transmitted intensity J is proportional to an absorbed dose by the subject being imaged. Compton scattering and photoelectric absorption account for the majority of the energy absorbed by the subject in the spectrum used for conventional X-ray imaging as described on p. 27 of Medical Imaging Systems by Albert Macovski, 1983 Prentice-Hall, Engelwood Cliffs, N.J. 07632.
In fluoroscopic systems, the radiation is pulsed at a rate to produce a continuous sequence of images, causing the dosage to become quite large. Fluoroscopy is commonly used in order to correctly position a catheter or similar invasive device inside a subject. Since these procedures may take a long time, the acquired radiation accumulates to a large total dose. A primary goal of diagnostic and interventional X-ray fluoroscopic procedures is to provide an accurate diagnosis while reducing the dose received by the subject and medical staff.
Attempts have been made to reduce dose absorbed by the subject and medical staff during fluoroscopic procedures. These attempts can be classified into three categories:
(1) mechanical redesign of elements of an X-ray system such as the X-ray grid, grid cover, scintillator, table top, cassette front etc. to reduce scattering; PA1 (2) the use of protective gear (e.g., gloves and glasses, although the use of lead gloves hampers the ability to perform the fine movements necessary for catheter placement); and PA1 (3) control of X-ray tube parameters. PA1 a) reducing the duration T of each X-ray pulse or the rate at which the source is pulsed; and PA1 b) reducing the power transmitted by the X-ray source.
The control of X-ray tube parameters may be broken down into two methods for reducing the total X-ray dosage. These are:
Pulse duration T has been reduced to limit the radiation dose as described in Effect of Pulsed Progressive Fluoroscopy on Reduction of Radiation Dose in the Cardiac Catheterization Laboratory, by D. Holmes, M. Wondrow, J. Gray, R. Vetter, J. Fellows, and P. Julsrud, Journal American College of Cardiology, vol. 15, no. 1, pp. 159-162, January 1990 and hereby incorporated by reference. Imaging by reduced pulse rate has the advantage of maintaining the important diagnostic signal at its original high contrast level for a given dosage, but does not collect as many frames. However, the fixed rate reduction methods produce visible jerky motion artifacts. These artifacts may also introduce time delays between a physician's actions and viewed results (e.g., moving a catheter or injecting radio-opaque dye).
A technique for imaging using reduced pulse rates triggered by the subject's organ activity was disclosed in U.S. patent application "Fluoroscopic Method with Reduced X-Ray Dosage" Ser. No. 07/810,341 by Fathy F. Yassa, Aiman A. Abdel-Malek, John J. Bloomer, Chukka Srinivas filed Dec. 9, 1991 assigned to the present assignee and hereby incorporated by reference. Although this technique reduces dosage by reducing the pulse rate, it does not adjust the power transmitted by the X-ray source which may further reduce dose.
Incorrectly reducing the power transmitted by the X-ray source may lead to poor quality images with reduced diagnostic content-the image may be characterized by global graininess and low contrast about important features such as the catheter, balloon, vessel boundaries, etc. Attempts to improve signal to noise ratio via noise reduction filters affect the overall image quality by averaging-out the noise contribution and result in the resultant image quality being of questionable value since the diagnostic information is less exact at lower doses than at higher doses.
The X-ray tube voltage and current necessary to produce a high quality image also depend on the area of the body under study. It is well known that different tissue types attenuate X-rays differently. For example bone is quite dense, requiring high-energy X-ray photons for penetration, while fat, is quite transparent to high-energy photons. Fat requires lower-energy X-rays to retrieve an image with good definition of the embedded features (e.g., contrast).
Since conventional fluoroscopy systems may incorrectly calculate X-ray tube voltage and photon count, subjects may be exposed to more radiation than is necessary, or the images produced may be grainy and lack desired contrast.
Currently, there is a need to accurately determine the required X-ray tube voltage and photon count and produce a high quality image, while also minimizing the X-ray dose to the subject.

X-ray dose reduction in pulsed systems by adaptive X-ray pulse adjustment


The invention converts a digital HDTV or SDTV video and/or audio signal(s) into an analog signal which is compatible with existing analog systems. The compatible analog signal carries the digital video and/or audio in a quasi digital form which provides immunity to analog noise and distortion. Digital video and audio are compressed to provide digital compressed signals that are coupled to a digital to analog formatter where they are formatted into an NTSC, PAL, or SECAM compatible analog signal. The active video portion of the signal uses a multilevel pulse amplitude coded signal to carry the digital compressed signal. The converted analog signal can then be stored or transmitted using existing NTSC, PAL, or SECAM standards and equipment.

Devices such as the RCA DTC-100 allow for a HDTV broadcast to be viewed on an analog TV set. This is what is commonly known as a down converter which looses much of the HDTV signal detail when creating a NTSC signal. The present invention enables recording a SDTV (Standard Definition TV) or a HDTV (High Definition TV) digital signal, carried in compressed form, on a standard definition, analog (NTSC) video recorder, with the recording being essentially a digital recording. This is accomplished with no information thrown away and with a recording process, which is lossless.
Many articles (HDTV's Future Out of Focus, Jul. 31, 1998, Stewart Jennison of Messenger-Inquirer) discuss conversion of HDTV signal to an analog signal.
Integrated circuits or chips on the market today perform various functions with analog and digital SDTV and HDTV signals such as converting analog SDTV and HDTV signals to digital and vice versa. Other ICs perform MPEG compression and decompression of digital HDTV and SDTV signals. Still other Ics perform conversion and compression of audio signals. As one example, the Philips device SAA7114H provides for decoding of an analog PAL/NTSC/SECAM video signal to supply a digital component (Y, R-Y, B-Y) version of the input signal This IC and many others which are capable of such processing can be found on the internet web site for the respective companies. As another example, Texas Instrument chips THS8133 and THS8134 provide for digital to analog conversion of a digital HDTV signal. These and other similar chips provide a useful function for converting analog video to digital while other chips in the same product lines convert digital video to analog, which can be found in the discussion of the present invention. Motorola Super-Chip DSP56366 is a generalized digital signal processing IC which is capable of compression and decompression of digital audio signals. Program ROMs are available for several audio functions, for example decompression of MPEG or Dolby compressed audio signals. This chip provides a useful function for audio decompression, which can be found in the discussion of the present invention. C-Cube chip CLM4700 performs digital video encoding of MPEG digital video signals and, as such, can be useful for video compression as an element of the present invention. C-Cube also has available companion chips which perform decompression of compressed video signals.
It is known to convert CCIR 601 type digital video signal and AES/EBU audio signals to NTSC/PAL/SECAM analog audio and video for recording on existing analog video tape machines, with the subsequent conversion of the played back analog signals to digital Such systems are sold to enable the use of existing analog recording machines in CCIR 601 digital systems, thereby eliminating the need to replace the existing analog recording machines with new digital recording machines. The recorded signal is however an analog video signal and is subject to typical analog recording degradation such as added distortion and noise. This process of converting a digital signal to analog whereby the analog version is recorded is unlike the present invention which as will be explained in more detail uses a standard analog recorder to record a video and audio signals in digital form. The prior art system of converting to analog for recording works reasonably well because a CCIR 601 digital video signal contains only the same amount of information (i.e. image detail) as a standard analog NTSC/PAL/SECAM video signal. Thus CCIR 601 signals may be converted to analog and back with little loss of image detail, but with each conversion adding noise and distortion. Thought of in another way, the bandwidth of the analog signal necessary to carry an analog version of a CCIR 601 digital signal is compatible with analog NTSC/PAL/SECAM bandwidth standards In addition, while CCIR 601 allows for several audio channels, typically only two are used, which is compatible with the two analog audio channels which are typically provided in analog systems.
Unfortunately, the amount of image detail contained in any of the standard HDTV signal is far in excess of that of a CCIR 601 digital signal, and when such HDTV signals are converted to analog the resulting analog signal bandwidth is far in excess of that which is compatible with NTSC/PAL/SECAM standards and equipment. Consequently the aforementioned system of converting to analog and back to allow existing analog equipment to be used with HDTV signals will not work without a severe loss of image detail. Further, most HDTV audio signals are typically 4 or more channels with existing analog equipment typically providing capability for only two analog channels. Consequently, HDTV audio channels in excess of that provided in the existing analog equipment cannot be accommodated.

System and method for enabling compatibility between digital and analog television systems


An optical encoder is a reflecting triple grating type optical encoder. A light projecting section of the optical encoder which includes a combination of a bare chip LED and a first grating of a first pitch p1, irradiates a predetermined light. A photodetecting section of the optical encoder which includes a combination of a photodetector and a third grating of a third pitch p3 detects a movement of a self image. Each of the first grating and the third grating is disposed substantially parallel with respect to a scale, and a substantially parallel and substantially flat light transmitting area is formed in a predetermined portion of a surface of a detecting head. A light transparent member is disposed in a space between the surface of the detecting head, and the first grating and the second grating.

1. Field of the Invention
The present invention relates to a reflecting triple grating type optical encoder which detects a position of an object to be detected.
2. Description of the Related Art
An optical encoder which includes a detecting head and a scale are hitherto known (refer to Japanese Patent Application Laid-open Publication No. 2003-166856 for example). FIG. 21 shows an example of a structure disclosed in Japanese Patent Application Laid-open Publication No. 2003-166856. The detecting head includes a light source 14 in which a first grating 11 is disposed, and a photodetector 50 in which a third grating 30 is disposed. Moreover, a second grating 20 is formed on a scale 21. Light emerged from the light source 14 forms a self image on a light receiving surface of the photodetector 50 upon being affected by the first grating 11 and the second grating 20. In this patent application, "self image" means an optical pattern having a shape substantially similar to the second grating 20 formed on the light receiving surface of the photodetector 50. Moreover, the self image moves according to a relative displacement of the detecting head and the scale 21. The photodetector 50 detects the movement of the self image. Such type, hereinafter, will be called as a "reflecting triple grating type".
In the reflecting triple grating type optical encoder, it is desirable to perform a detection which is not affected easily by a change in a distance between the scale and the detecting head. For this, the first grating and the third grating included in the detecting head are disposed by lining up the heights thereof. Moreover, the self image can be classified into the following two typical cases (a) and (b) for example, according to structural conditions of the optical encoder, where
case (a) is a case of having a same space period as of a shadow pattern of the second grating, and
case (b) is a case of having the space period ½, ¼, and . . . of the shadow pattern of the second grating.
The most stable and the clearest image is formed in the case (a) mentioned above. Therefore, the case (a) mentioned above will be described below.
When the following conditional equation (1) is satisfied, a self image having the same space period as of the shadow pattern of the second grating is observed on the light receiving surface of the photodetector.1/z1+1/z2=λ/(k×p22)  (1)where,                λ denotes a central wavelength of light emitted from the light source,        z1 denotes an optical distance between the first grating and the second grating,        z2 denotes an optical distance between the second grating and the third grating,        p2 denotes a pitch of the second grating, and        k denotes a natural number.
Here, when                Δz0 is let to be a difference between z2 and z1, which is designed in advance,        Δz is let to be a difference between z2 and z1 when actually manufactured, and        Δzd is let to be a difference between Δz0 and Δz which occurred when actually manufactured (in other words, a difference between Δz0 designed in advance and Δz when actually prepared) the following equation (2) holds.Δz=Δz0+Δzd  (2)
Inventors of this patent application performed the following experiment, and calculated a tolerance of Δzd required for achieving satisfactory signal strength by the photodetector. According to results of the experiment, it was revealed that, with predetermined conditions, to achieve the satisfactory signal amplitude at the photodetector, such as signal strength at which the maximum signal amplitude is ½ for example, the tolerance of Δzd is ±36 μm. Moreover, it was revealed that with other conditions, for achieving the satisfactory signal strength at the photodetector, the tolerance of Δzd is approximately ±33 μm. Generally, the tolerance of machining accuracy is in a range of ±50 μm to ±100 μm. Therefore, from a point of view of manufacturing, it is extremely difficult to dispose by mounting the first grating, the second grating, and the third grating such that the Δzd is in a range of ±36 μm to ±33 μm. Moreover, when an attempt is made to realize an optical encoder in which Δzd is not greater than the range of ±36 μm to ±33 μm, a dimensional tolerance of structure members of the optical encoder being small, it becomes very difficult to manufacture at a low cost. Moreover, in the conventional example described above, a concrete method or a structure which is assembled with the tolerance Δzd to be very small is not at all disclosed.

Triple grating optical encoder with light transmitting area in optical path


Light detectors that combine field emission with light focusing by surface plasmon polaritons. Methods and devices that allow detection and measurement of light at high frequencies in the THz range are described. The disclosed devices include plasmonic metal contacts with a narrow nanometer-sized gap to couple an optical waveguide mode into a plasmonic mode thereby generating filed emission currents by biasing the contacts.

Photodetectors include devices such as photomultiplier tubes, bolometers and semiconductor detectors. Fast detectors typically require the use of semiconductor materials that convert photons to electron-hole pairs and change the conductivity or provide photocurrent. Generally, the energy of the photon must exceed a threshold energy, usually the bandgap, which enables electrons or holes to be generated and measured. These carriers have to move to electrical contacts before they can be detected, and this carrier transit time typically limits the ultimate frequency response of a photodetector. In designing a high frequency detector, the capacitance of the device and distance between carrier generation and contacts are generally minimized. Amplification of electrical signal is accomplished by introducing either a transistor or a carrier multiplication mechanism such as an avalanche photodiode or integrated phototransistors.
FIG. 1 shows a prior art germanium (Ge) p-n diode detector (100) integrated on a silicon (Si) waveguide. By coupling light from the 6 μm diameter mode of a glass fiber (110) into a 200×400 nm Si waveguide (120), the optical field is concentrated by a factor of over 300×. Typically, the waveguide consists of a different material than the detecting material, as light should not be absorbed before it can reach the detecting region. In FIG. 1, light is detected through a reverse-biased in-plane p-n diode (130), and current between contact (141) and contact (142) is measured. In this case, light is coupled from the Si waveguide (120) into the Ge detector region, and electron-hole pairs are generated in the depletion region of the p-n diode (130).
The operating frequency limit of the detector (100) of FIG. 1 is typically determined by the distance between the contacts and the carrier generation region. It should be noted that the maximum velocity of electrons in semiconductors is limited to the saturation velocity, which for silicon is approximately 1×10{circumflex over ( )}7 cm/s, and is approximately 2× higher for InP and GaAs. For carriers moving 100 nm in the semiconductor waveguide/detector region, this translates into a transit time of about 10{circumflex over ( )}12 seconds, or a fundamental frequency limitation of the photodetector to 1 THz. Therefore, there is a need for faster photodetectors functioning at higher frequencies, above 1 THZ.

Waveguide integrated plasmon assisted field emission detector


Moldable and pigmentable heat-curable compositions which can be employed for forming molded articles with zero or practically zero shrinkage (low profile type) or a small expansion include a heat-curable resin, a catalyst, a (meth)acrylic polymer in powder form with a dimension smaller than 150 .mu.m, at least one inorganic filler and, optionally, reinforcing fibers and organic or inorganic pigments.

The invention relates to moldable heat-curable compositions, based especially on unsaturated polyester resin, for obtaining molded articles with a practically zero final shrinkage (generally called "low profile"-shrinkage of approximately between 0 and 0.05%) or a slight expansion, that is to say an increase in size, for example, from +0.2% to +0.09%.
Conventional unsaturated polyester resins usually include an unsaturated polyester diluted in a monomer containing ethylenic (vinyl or acrylic) unsaturation in order to adjust the viscosity as a function of the intended application. This monomer serves as a solvent for the polyester and for the crosslinking agent. A shrinkage in volume is observed during the crosslinking (or curing) of the polyester and of the monomer. This shrinkage results in cracks, faults in appearance and distortion of the articles. Shrinkage-compensating agents are therefore added, which are generally thermoplastic substances. If introduced in the form of powder or diluted in styrene, these agents are of a polystyrene, polyethylene, polyvinyl chloride or polymethyl methacrylate nature, resulting in linear shrinkages, after molding, of 0.2% to 0.1% (low shrink) or else of polyvinyl acetate, saturated polyester or elastomer kind, resulting in shrinkages close to zero (low profile). Whether these shrinkage-compensating additives are or are not soluble in the resins before crosslinking, they produce a phase separation at the time of the crosslinking. The microdomains formed give rise to a vacuum volume compensating the shrinkage of the polyester.
Heat-curable compositions which have zero shrinkage and are prepared from shrinkage-compensating additives known hitherto are impossible to pigment homogeneously; in particular, whitish marbling effects. are observed. It is therefore not possible to obtain molded articles containing pigments or dyes distributed homogeneously in bulk. This presents a problem when it is desired to manufacture colored molded articles, for example in the field of household electrical appliances.
Moldable heat-curable compositions also find an application in fields in which it is desired to obtain molded articles with a perfectly smooth surface which can be coated, for example, with a layer of paint, varnish or with a metallic substance: this is the case, in particular, with motor vehicle components, for example components for the bodywork and reflectors for lighting devices.
Bodywork components for motor vehicles are manufactured by molding, for example compression or injection molding, of heat-curable materials of the BMC (Bulk Molding Compound) type or of the SMC (Sheet Molding Compound) type including chiefly an unsaturated polyester resin, inorganic fillers and reinforcing fibers and at least one shrinkage-compensating agent. This agent is particularly important in the case of the BMCs or the SMCs intended to form bodywork components, because in some cases it is necessary to obtain zero or practically zero shrinkage (low profile) and, in other cases, a slight expansion in order to meet the requirements of class A of the motor vehicle sector (for example obtaining a perfectly smooth surface without shrinkage cavities).
Molding components intended for motor vehicles, for example those intended for the bodywork or components of the engine compartment must be capable of being painted. Painting of components made of polyester generally requires the deposition of a bonding coat (also called a primer coat) which promotes the adhesion of the coats of paint and improves the surface quality before they are applied. In the case of paints applied, for example, by electrostatic gun-spraying a conductive coat must be deposited beforehand.
To avoid this pretreatment, thought has been given to introducing conductive pigments into the heat-curable mixture. However, as already indicated, with compositions containing shrinkage-compensating agents such as those employed hitherto to obtain shrinkage of the low-profile type or a slight expansion, obtaining a homogeneous pigmentation is difficult and, in the case of a molded article, this results in a surface quality which is not suited for the deposition of a smooth and uniform coat of paint by electrostatic gun-spraying.
Heat-curable materials can also be used for the manufacture of (paraboloid) reflectors for lighting devices, for example for motor vehicles. The reflector must have a reflective surface of very good quality. For this purpose the concave inner surface of the reflector is covered with a thin coat of aluminum. Before the deposition of this coat (aluminum coating), the molded articles are subjected to a preliminary treatment, for example the deposition of a varnish, intended to impart perfect surface quality to the article and to promote the adhesion of the aluminum coating. Another possible treatment is to make the surface antistatic and to perform a deposition of powder at elevated temperature, to obtain a film which promotes the adhesion of the aluminum coating.
These treatments are costly and it would naturally be desirable, for obvious reasons of economy, to make it possible to eliminate the pretreatments of the articles molded from BMC or SMC heat-curable materials, regardless of whether this is the treatment before the deposition of paint or else that before the coating with aluminum, and hence to obtain moulded articles whose surface quality allows the aluminum or paint to be deposited directly.

Moldable and pigmentable heat-curable compositions capable of being used for obtaining molded articles with zero shrinkage or small expansion


This invention relates to a breast pump which can perform the automatic suction with the following advantages: 1) a breast-milking mother can stop the operation of breast pump immediately, when her breast site feels painful through continual suction, 2) the suction can be immediately made available by re-pushing a switch, thus more convenient to use, 3) since the breast pump has a massage function in addition to the basic suction of human milk, thus removing a breast stiffness in an efficient manner and improve the overall functions of the breast pump, 4) the rapid detachment of the breast pump after use can be accomplished through a suction release value, thus making the separation procedure of breast pump easier, 5) since the induction neck of breast pump is equipped with a separate induction conduit which is extended to the inside of a breast milk bottle, human milk can be directly dropped to the bottle, whereby disinfecting the bottle is unnecessary, and 6) since the breast milk bottle is connected to the main body of the breast pump with a transparent hose, the attachment of the breast pump to the mother""s nipple and breast can be easily seen.

Field of the Invention
This invention relates to a breast pump used for squeezing human milk with the following advantages:
1) The automatic suction can ensure the convenience in use;
2) The additional massage function can contribute much to diverse performances;
3) Since the suction neck of breast pump is equipped with a soft induction neck designed to cover the breast site, any discomfort during use can be removed, while the breast pump can be easily detached using a suction release valve; and,
4) Since an induction neck is equipped with a separate induction conduit, human milk can be directly dropped to the floor of breast milk bottle, thus preventing the contamination of breast milk bottle; and,
5) Since the breast milk bottle is connected to the main body of breast pump with a transparent hose, the insertion of breast pump to mother""s nipple can be directly ascertained by naked eyes.
In general, a breast pump is intended for use to squeeze the first human milk from child-born or forcibly squeeze excessive amount of human milk during lactation. The breast pump is divided into manual and automatic types.
In the case of the manual breast pump, a lactating woman makes a manual pumping process by hands and thus a lot of force is inevitably required with inconvenient usage. To be harmonious with this matter, various types of automatic breast pump have been recently marketed.
However, the conventional automatic breast pump lacking any massage function has failed to remove the breast stiffness with the following disadvantages:
1) With a switch on, an automatic breast pump has a continuous operation. A breast-milking mother cannot stop the operation of breast pump immediately, when her breast site feels painful through continual suction. Furthermore, when a switch is off, the switch operation is quite cumbersome.
2) Since the suction force is controlled by inflow air, the continuous operation of motor results in excessive electric consumption.
3) Since the main body of breast pump is directly attached to the upper part of human milk bottle, there is a high risk on the malfunction or internal contamination of breast pump.
4) Since the inside of human milk bottle cap is smeared with human milk flowing from the bottle via suction neck, the human milk bottle needs to be disinfected every time during use.
5) The conventional automatic breast pump lacking diverse functions has a simple suction without any massage function.
To free from the aforementioned shortcomings, this invention relates to a breast pump which can perform the automatic suction with the following advantages:
1) A breast-milking mother can stop the operation of breast pump immediately, when her breast site feels painful through continual suction;
2) The suction can be immediately made available by re-pushing a switch, thus ensuring the convenience in use;
3) Since the breast pump has a massage function in addition to the basic suction of human milk, thus removing a breast stiffness in an efficient manner and improving the whole functions of breast pump;
4) Since a suction neck has a soft induction neck designed to softly contact with a breast site, a lactating woman feels comfort during use, and the rapid detachment of breast pump after use can be made through the fabrication of suction release value, thus making the separation procedure of breast pump easier;
5) Since the induction neck of breast pump is equipped with a separate induction conduit which is extended to the inside of a breast milk bottle, human milk can be directly dropped to the bottle, whereby any disinfection for bottle is unnecessary; and.
6) Since the breast milk bottle is connected to the main body of breast pump with a transparent hose, the insertion of breast pump to mother""s nipple can be directly ascertained by naked eyes, thus preventing any smear in the bottle.


A thin-film magnetic head has a slider formed of nonmagnetic polycrystalline Mn--Zn ferrite containing from 0.02 to 7 wt % of at least one member selected from the group consisting of CaO, MgO, ZrO.sub.2, SnO.sub.2, Al.sub.2 O.sub.3, SrO and NiO. Concave-convex surface having height difference is given to air bearings on a floatation surface side of the slider so that the convex portions occupy the area percentage in a range of from 20 to 80%.

The present invention relates to a thin-film magnetic head with superior CSS (contact, start and stop) characteristics, particularly for use in a small-sized high-density recording magnetic disk device.
Recording-reproducing floating type magnetic heads in magnetic devices are classified into three types, namely, a monolithic type in which the whole structure thereof is formed of soft-magnetic ferrite, a composite type in which, only for an electromagnetic transducer portion, a soft-magnetic Mn--Zn ferrite core or a magnetic head core with a metal magnetic thin film is produced and incorporated in a slider formed of a nonmagnetic material, and a thin-film type in which an electromagnetic transducer portion formed of a metal magnetic thin film is provided on a nonmagnetic substrate.
Composite type magnetic heads are mainly used as floating type magnetic heads for 3.5-inch or less than 3.5-inch high-density small magnetic disk devices. With the advance of increase of the recording density, there is a tendency to use more frequently thin-film type magnetic heads in which an electromagnetic transducer portion is formed on a nonmagnetic substrate by lithographic and thin-film techniques, and which have been heretofore mainly employed in large-sized devices.
The nonmagnetic slider used in thin-film type heads requires optimum relations in coefficient of thermal expansion from the double point of view of production and use because a metal magnetic film is formed on an Al.sub.2 O.sub.3 film generally formed on a trailing edge of the slider. From such relations, a substrate material formed of alumina titanium carbide (ATC) as a main material is generally used for the slider.
In order to meet the recent advance of increase of the recording density in magnetic disk devices, hard disks of the type in which a magnetic substance is closely deposited onto a disk substrate through plating or sputtering, are used as magnetic recording media.
The surface of the disk produced through plating or sputtering as described above is finished up with flat and fine surface roughness compared with the conventional coating type disk and is overcoated with a lubricant. Accordingly, the sticking phenomenon which occurs in between the head and the disk surface has come up to a serious problem though it was a minor problem up to now. That is, as the surface roughness of the surface facing the magnetic recording medium becomes finer, there arises a phenomenon that the surface of the disk in a state of rest is stuck to the surface of the head facing the disk. When the adhesion between the head and the disk becomes intensive excessively, the adhesion exceeds motor torque for rotating the disk so that the device cannot operate easily. At the same time, the lifetime against CSS (contact, start, and stop) operations is shortened. In particular, in the case where a plurality of disks are used in combination, the problem becomes more serious.
In order to relieve the sticking phenomenon, various means for treating the surface of the head facing the disk to make it rough to some degree have been proposed.
As one of the means for solving the problem, Japanese Patent Unexamined Publication No. Hei. 1-251308 (U.S. Pat. No. 5,010,429) discloses a floating type magnetic head formed of a polycrystalline material, in which air bearing surfaces as surfaces facing a magnetic recording medium are formed with convex-concave surface having height difference of 50 to 200 .ANG. on an average and repetition pitch of convex and concave of 5 to 20 .mu.m on an average, and the portions, in which the heights of convex and concave abruptly change, extend along the grain boundaries of the polycrystals. FIG. 4 is a perspective view of a monolithic type magnetic head as an example thereof.
The monolithic type magnetic head is, however, not suitable for magnetic disk devices requiring higher-density recording in the future because the whole structure is formed of a soft-magnetic material so that this type magnetic head has disadvantages, for example, in that the inductance (L) of the head is large, therefore, it makes the high-frequency response poor and thereby produce noise easily.
FIG. 5 is a perspective view showing an example of the thin-film type magnetic head. The reference numeral 10' designates a magnetic head, 11' air bearings, 12' an electromagnetic transducer portion and 13' a slider. Alumina titanium carbide used in a substrate constituting the slider of the thin-film head, is a material in which a problem may be caused by a lubricant of the disk as a recording medium because titanium carbide is active and in which another problem may be caused in workability because it has high hardness with the Vickers hardness of about 2,000 Kg/mm.sup.2. Furthermore, it is difficult to form suitable concave-convex level differences in the surface of the head facing the magnetic recording medium. Accordingly, in particular, the CSS characteristic becomes a problem in the floating type magnetic head requiring the flying height of less than or equal to 0.1 .mu.m with the advance of reduction in size and increase in recording density.
The inventors of the present invention have disclosed nonmagnetic Mn--Zn ferrite for a magnetic head in Japanese Patent Unexamined Publication No. Hei-3-126662 and have further disclosed a composite type floating type magnetic head having a slider formed of nonmagnetic Mn--Zn ferrite in Japanese Patent Unexamined Publication No. Hei-3-127315.
The inventors of the present invention have made further researches and, as a result, have made it possible to provide a thin-film magnetic head in which suitable concave-convex surface having height difference is given onto air bearing surfaces by using nonmagnetic Mn--Zn polycrystalline ferrite to approximate the co-efficient of thermal expansion thereof to the coefficient of thermal expansion of the Al.sub.2 O.sub.3 film formed between the slider and the metal magnetic film to thereby attain good CSS characteristic and avoid separation of the metal magnetic film.


A fillet board for filleting fish having spines or horns on their pectoral fins extending outwardly from the sides of the fish body. The board defines apertures each sized to receive the horn of a fish laid flat on one side with the horn secured by the board. A plurality of apertures are sized and spaced along a portion of the length of the board to accommodate fish of different sizes. The fillet board has a spacer element to elevate the board above a supporting surface to provide clearance for fish horns to extend below the board. The fillet board includes a tail clamp for securing the tail of a fish.

1. Field of the Invention
This invention relates to a fillet board for fish.
2. Related Art
Virtually all fish, after being caught, require some method of making the edible flesh available to eat. One of the most desirable ways to provide fish meat is as a fillet in which the larger longitudinal, or side, portions of the fish meat are excised from the body, providing fish meat that is free of bones and skin. While filleting a fish is one of the most desirable ways to prepare fish, not all fish are as easily filleted as others. For example, bullhead and catfish possess spines on their pectoral and dorsal fins, commonly referred to as horns. Bullhead and catfish horns are extremely stiff and sharp and in some species of catfish are venomous. The presence of horns requires careful handling of the bullhead and particularly catfish and makes filleting such fish quite difficult, as the size and stiffness of the horns make it difficult to lay the fish flat on its side to fillet the fish.
There are a variety of fillet boards available that attempt to make filleting fish easier; however, Such fillet boards are not easily usable with fish having horns. One such fillet board is described in U.S. Pat. No. 5,116,279 to Perry. Perry discloses a folding fillet board, which is essentially a portable platform having a central clamp for the fish's tail and a movable hook to aid in hands-free removal of the carcass. Another fillet board devised to aid in fish filleting is illustrated in U.S. Pat. No. 4,030,164, to Fick, which describes a fillet board with a serrated oval opening so that the fish's gill flap or operculum fits within the opening, holding the fish to the fillet board and providing a flat surface for filleting the fish. U.S. Pat. No. 3,878,586 to Hoppert et al. discloses a catfish cleaning board. Hoppert et al. avoid the problem of fish horns by securing the fish on its belly for cleaning, a position that makes filleting a fish very difficult.

Fillet board for use with fish having horns


An upscaler for upscaling a source image to generate a destination image without requiring large buffers. The aspect ratio (ratio of the length of the source image to that of the width) of the source image need not equal the aspect ratio of the destination image. The source image pixel data is received at a first clock rate and the destination image is generated at a second clock rate. The second clock rate is computed such that the frame rate at which the source image is received is the same as the frame rate at which the upscaled image is generated. Because of such a clock rate, the upscaler may be implemented using only a line buffer.

1. Field of the Invention
The present invention relates to graphics systems, and more specifically to a method and apparatus for upscaling a source image to generate a destination image.
2. Related Art
Graphics systems often display images on display screens. For example, a computer system may display the image of an object on a flat-panel monitor. Television systems and cameras are some of the other examples of such graphics systems. To achieve the display of an image, the image is generally represented by image data (e.g., RGB data or YUV data), and display signals are generated from the image data. The display signals cause the image to be displayed on a corresponding display screen.
During such a display, a graphics system may need to upscale the image. The upscaling may be needed for one or more of several reasons. For example, a source image may be provided in one resolution (e.g., 160.times.120 size image data from a CD-ROM decoder), and the image may need to be displayed on a larger display screen (e.g., 640.times.480 CRT screen). To take advantage of the larger display area, a graphics system may upscale the image.
In addition, with the advancements in user interfaces, a user of a graphics system may wish to have the image resized without maintaining the aspect ratio of the source image. That is, the image may need to be upscaled by different factors with regards to the length and the width. Thus, a user may specify that the image be doubled in the length dimension while upscaling the breadth dimension by a factor of 1.5. A well-designed graphics system should be able to meet such different needs of a user.
Graphics systems typically include special circuitry to upscale images. Examples of such circuitry include well-known graphics controller chips typically housed on a mother board of a computer system and special chip sets provided with LCD panels of computer systems and video cameras.
While providing the upscaling functionality, the special circuitry may need to meet specific requirements of the environment of usage. For example, if the special circuitry is used in a flat monitor, the circuitry may need to be compact. Without such compactness, the circuitry may be unsuitable for flat monitor environments where it is critical that circuitry occupy minimal space. In addition, it may be desirable to keep to a minimal level the total amount of power consumed by the special circuitry, particularly in the portable applications market (e.g., laptop computers).

Method and apparatus for upscaling an image


A hydroformed tubular frame member includes an internal bulkhead member that is formed during the hydroforming process during which the frame member is manufacture from tubular stock material. The internal bulkhead is cut from one face by piercing three sides of a weld access opening with the die in which the tubular frame member is formed during the hydroforming process. The bulkhead member is then bent along the fourth side of the weld access opening and shaped into a folded configuration that includes a vertical portion spanning the distance between the opposing faces of the frame member, and a horizontal portion to facilitate welding to the opposing face. The provision of the internal bulkhead member increases stiffness in the tubular frame member and reduces the matchboxing effect associated with hydroformed tubular frame members. The frame member with internal bulkhead is particularly advantageous in manufacturing an automotive frame.

Conventional front end assemblies in automotive vehicles are often made by stamping and welding together several individual frame components. One of the major challenges for manufacturing is to maintain rigidity because these assemblies are often a combination of a number of various frame parts. As each of the frame parts are attached to form subassemblies and then are attached to the body portion of the vehicle, it becomes more difficult to achieve the necessary or desired stiffness in the front end. This problem is sometimes referred to as "matchboxing." Matchboxing is a phenomenon that occurs when the sheet metal portion of the vehicle is attached to the frame and tends to sway on a hinge point and move from a desired perfect square orientation to a parallelogram orientation. Distorting the sheet metal in this manner may result in poor natural frequency characteristics of the front end structure.
Manufacturing processes for automobiles have evolved from one that utilized MIG welding processes, i.e. a welding process in which a line of molten material is deposited by the welder in joining two pieces of metal together. Spot-welding, a process involving the passage of electrical current between two electrodes to melt and join two pieces of metal placed between the electrodes, is being utilized in a greater degree in the manufacturing of automotive vehicles. Spot-welding requires a frame design that is conducive to being manufactured using the spot-welding process. For example, if two tubular members are being spot-welded, access to the adjoining walls of the two tubular members by the spot-welder electrodes must be provided.
Hydroformed tubular elements are frequently being used in the construction of vehicle body structures to take advantage of the spot-welding manufacturing techniques. Hydroforming is a metal forming process that uses high pressure fluids to outwardly expand tubular blanks into a die so that the tubular blank conforms to the surfaces of the die cavity, thus forming a contoured hydroformed part. Access openings in the contoured hydroformed part for the insertion of spot-welding electrodes can be formed during the manufacturing process by inserting cutouts in the die cavity so that the periphery of the tubular wall is pierced by the cutout during the expansion process. The leftover slug is usually completely removed from the hydroformed part.
Vehicle front end hydroformed structure requires tube-to-tube and tube-to-cowl welded joints in the formation of the manufactured vehicle front end. Such welded joints require large weld access openings that often remove most of the material on a side of the hydroformed structural member. Once assembled, the operative vehicle front end the hydroformed tubes undergo bending and torsion modes. During this torsion cycle, the hydroformed tubes tend to matchbox, which creates higher loading in the tube-to-tube and tube-to-cowl joints and can cause material fatigue and cracking. This matchbox phenomenon is more likely when the hydroformed members have been formed with a large weld access opening. Increasing the stiffness of hydroformed parts can be accomplished through conventional means by increasing the gage (or thickness) of the material, by making the part large (increasing the geometry of the member), by attaching secondary reinforcements (such as by welding); or by using pre-formed structural foams, all of which add significant cost to the manufacture of a vehicle front end assembly.
Vehicle front end assembly processes have yet to take full advantage of the capabilities of tubular hydro-formed parts. A number of prior patents have described the use of tubular members in hybrid front end assemblies, but fail to address the matchboxing issue. For example, Gerricke et al., U.S. Pat. No. 6,416,119, describes a vehicle front end constructed through the use of hydro-formed tubes. In Gerricke, a first body structure formed from a plurality of tube members and a second body structure formed from sheet metal are welded to each other in a sandwiching relationship. However, this method is still subject to matchboxing because the sheet metal structure can be distorted as it is secured to the tube members.
There is a need for a front end construction that may incorporate the use of hydroformed tubes that provides superior stiffness and rigidity capabilities. There is a further need for a front end assembly process that minimizes any tendency of the assembly to distort or matchbox.

Hydroformed members with internal bulkhead


A multi-chip module (MCM) assembly comprising: a graphite substrate comprising a plurality of silicon chips directly attached to the graphite substrate, and a Printed Wiring Board (PWB) attached to the graphite substrate by means of a solvent-resistant adhesive glue and provided with openings surrounding outer profiles of the silicon chips. A printing bar comprising a plurality of the MCM assemblies is also disclosed.

The concept of a multi-chip module (MCM) has been well known for a long time. Technological and economical reasons dissuade the manufacturers from increasing the length of a silicon chip. Accordingly, a longer and more effective print swath can be reasonably obtained only through a plurality of silicon chips, properly disposed onto a rigid substrate and thereby forming the MCM. Shaping the outer profile of a single MCM in a suitable way allows building an even longer printing bar, through the simple juxtaposition of several MCMs.
U.S. Pat. No. 5,016,023 discloses a structure comprising printheads, which are offset with respect to adjacent printheads by an amount at least equal to a width dimension of a printhead. The disclosed structure involves a use of a ceramic material as a substrate suitable for withstanding certain elevated temperatures. However, the manufacturing process of the ceramic substrate is rather expensive, because it requires a specific mold to get the desired shape at once or, alternatively, the use of some hard-tooling equipment to machine such a hard material. Moreover, the set of buss lines and IC packages disclosed in U.S. Pat. No. 5,016,023A are also rather complex and therefore not technologically efficient, reliable and cost-effective.
U.S. 5,939,206 describes an apparatus which comprises at least one semiconductor chip mounted on a substrate, said substrate comprising a porous, electrically conductive member having electrophoretically deposited thereon a coating of a polymeric material, wherein said porous, electrically conductive member comprises graphite or a sintered metal. However, the construction and maintenance of an electrophoretic deposition line is rather expensive that makes the apparatus manufacturing process complex and costly.
It is therefore an object of the present invention to overcome the shortcomings of the prior art and to provide technologically efficient, cost-effective, safe and simple way to realize the electrical contacts, to increase the electrical and mechanical reliability of the multi-chip module assembly, and to ensure high printing quality of the printing equipment using the same.
Another object of the invention is to provide a respective printing bar comprising a plurality of multi-chip module assemblies that ensures achievement of the above-mentioned advantageous effects.

Multi-chip module (MCM) assembly and a printing bar


The present invention relates to novel compositions comprising light emitting materials and/or charge transport materials and a polymeric binder, to their use as conducting inks for the preparation of organic light emitting diode (OLED) devices, to methods for preparing OLED devices using the novel formulations, and to OLED devices prepared from such methods and formulations.

When preparing OLED devices usually printing techniques like inkjet printing, roll to roll printing, slot dye coating or gravure printing are used to apply the active layer. Based on low solubility of the most of the present organic compounds useful as emitting materials and/or charge transport materials, these techniques need the use of solvents in high amounts.
In order to improve the film forming ability binding agents can be used. These additives are especially needed with regard to light emitting materials and/or charge transport materials having small molecular weight or polymeric compounds having a low molecular weight.
EP 1 883 124 A1 describes a formulation of light-emitting material particularly suitable for forming displays and lamps via printing techniques comprising organic-light emitting material housed in protective porous matrix material, a binder and a solvent. However, the OLED material encompasses also polymeric materials. Furthermore, the binder material is disclosed as a long list without any detailed specification.
US 2007/0103059 discloses compositions comprising an OLED material and a polymer having very specific repeating units. The polymer having specific repeating units is added to improve the emitting efficiency of the OLED. Also polymeric OLED materials can be employed.
According to U.S. Pat. No. 6,818,919 and U.S. Pat. No. 7,115,430 polymers having a high glass transition temperature Tg have to be used in order to process low molecular weight organic light emitting and charge transport materials. However, these materials are expensive and limit the application of the compositions.
U.S. Pat. No. 5,952,778 relates to an encapsulated organic light emitting device having an improved protective covering comprising a first layer of passivating metal, a second layer of an inorganic dielectric material and a third layer of polymer. The organic light emitting material can be polymeric or monomeric. The composition can contain a polymer binder. However, the binder material is disclosed in a long list without any detailed specification.
U.S. Pat. No. 6,277,504 B1 discloses specific light emitting compounds and compositions comprising the same. The compositions may include a binder. However, no detailed specification of the binder is provided.
U.S. Pat. No. 6,294,273 B1 describes light emitting compounds being soluble in methanol. The compositions comprising these compounds may contain polymer binders. However, the binder material is disclosed in a long list without any detailed specification.
WO 2005/055248 A2 relates to compositions comprising specific organic semiconductor compounds and an organic binder having a permittivity of 3.3 or less at 1000 Hz. However, the specific organic semiconductor compounds as disclosed in WO 2005/055248 A2 should form a layer having a high crystallinity in order to achieve a high efficiency. In contrast thereto, layers emitting light should usually have a low crystallinity for providing high efficiency. Therefore, the concept of WO 2005/055248 A2 cannot be applied to OLED layers.
Solutions of small molecules in a solvent do not generally have a big effect on the viscosity of the resultant solution as occurs with polymers. Therefore, compositions of small molecules for conventional printing applications like ink jet printing, flexographic or gravure printing need additives to increase ink viscosity and improve film formation. The prior art provides compositions being useful in order to process low molecular weight organic light emitting and charge transport materials. However, it is a permanent desire to improve the performance of the OLED layer, especially in terms of efficiency, lifetime and sensitivity regarding oxidation or water.
It is therefore desirable to have fluids comprising light emitting materials and/or charge transport materials that are suitable for the preparation of OLED devices by the aforementioned solution based processes, which allow the manufacture of very homogeneous OLED devices having a high efficiency, a long lifetime, and a low sensitivity against water or oxidation. One aim of the present invention is to provide such improved fluids. Another aim is to provide improved methods of preparing an OLED device from such fluids. Another aim is to provide improved OLED devices obtained from such fluids and methods. Further aims are immediately evident to the person skilled in the art from the following description.
Surprisingly it has been found that these aims can be achieved, and the above-mentioned problems can be solved, by providing methods, materials and devices as claimed in the present invention, especially by providing a process for preparing an OLED device using a composition comprising a polymeric binder.

Compositions comprising polymeric binders


A semiconductor device has a configuration in which more than three kinds of wells are formed with small level differences. One kind of well from among the more than three kinds of wells has a surface level higher than other kinds of wells from among the more than three kinds of wells. The one kind of well is formed adjacent to and self-aligned to at least one kind of well from among the other kinds of wells. The other kinds of wells are different in one of a conductivity type, an impurity concentration and a junction depth, and include at least two kinds of wells having the same surface level.

1. Field of the Invention
The present invention generally relates to semiconductor devices and, more particularly, to a semiconductor device having more than three kinds of wells in the same substrate and a manufacturing method of such a semiconductor device.
2. Description of the Related Art
A formation process of a well in a semiconductor manufacture process does not only influence an electrical property of a transistor formed in a semiconductor device, but also plays a very important roll to give influences to even a chip area and a manufacturing cost. Although it has been general to form two kinds of wells, N-well and P-well, thus far, a third well different from the N-well and P-well has become used more and more in reflecting the demand for a high-performance device.
A purpose of forming such a third well is: 1) to enable a formation of a high-voltage-withstanding element by forming a well having a small concentration; and 2) to form a triple well structure by forming a well having a deep junction.
A low-concentration well having a conductivity of N-type is referred to as "lightly-N-well", and a low-concentration well having a conductivity of P-type is referred to as "lightly-P-well". The lightly-N-well and the lightly-P-well are indispensable for a high-voltage-withstanding element, which operates at a high-voltage range. It should be noted that, in the present specification, a well having N-type conductivity is simply referred to as "N-well" and a well having P-type conductivity is simply referred to as "P-well".
Moreover, the triple well structure permits mixing of a negative power-supply circuit and is capable of shielding noise, and is also capable of improving a reliability of a dynamic random access memory (DRAM), etc. Thus, the triple well structure is widely used in a digital/analog mixed LSI and a memory mixed LSI, which contributes to the recent popularization of mobile phones and mobile terminals.
The above-mentioned way of thinking can be applied also to a case where the number of kinds of wells is increased to four or five, and a description will be given of the case where three kinds of wells are provided in the same substrate. The three kinds of wells may be "N-well/P-well/Lightly-N-well", "N-well/P-well/Lightly-P-well", or "N-well/P-well/triple well".
There is suggested a method of forming the three kinds of wells as shown in FIG. 1 (refer to Japanese Laid-Open Patent Application No. 61-502993). FIG. 1 is an illustration for explaining the process of forming three kinds of wells, which are the N-well, the P-well and the lightly-N-well, in the same substrate.
As shown in FIG. 1-(A), first a nitride film 1 is deposited on a silicon substrate 10, and a resist pattern 2 is formed according to a photolithography process so as to define an area where a lightly-N-well is formed. Then, a part of the nitride film 1 corresponding to an opening of the resist pattern 2 is removed by etching using the resist patter 2 as a mask, and phosphorous ions 3 are implanted or doped into the substrate 10 using an ion implantation or doping technique.
Thereafter, as shown in FIG. 1-(B), the substrate 10 is heat-treated in an oxidizing atmosphere after removing the resist pattern 2. According to the heat treatment, an oxide film 4 grows in the area where the nitride film 1 is removed, and the phosphorous ions 3 implanted into the silicon substrate 10 is diffused, thereby forming the lightly-N-well (Lightly-NW) 5.
Then, as shown in FIG. 1-(C), a resist pattern 7 is formed according to a photolithography process without removing the nitride film 1 so as to define an area where an N-well is formed.
As shown in FIG. 1-(D), after removing a part of the nitride film 1 corresponding to an opening of the resist pattern 7, phosphorous ions 8 are implanted or doped into the substrate 10 using an ion implantation or doping technique.
Then, as shown in FIG. 1-(E), after removing the resist pattern, the substrate 10 is heat-treated within an oxidizing atmosphere so as to cause an oxide film 2 growing up in the area where the phosphorous ions 8 are implanted or doped. Accordingly, the implanted or doped phosphorous ions 8 are diffused, which forms the N-well (NW) 20. At this time, since the previously formed oxide film 4 is exposed, the oxide film 4 is influenced by the heat treatment for forming the oxide film 9 and turns into an oxide film 4c having a thickness larger than the original film thickness. This lowers the level of the surface of the lightly-N-well 5c. Although the film thickness of the oxide film 4c depends on a condition of the oxidation process, if the condition of the oxidation process to form the oxide film 4 is the same as the condition of the oxidation process to form the oxide film 9, the film thickness of the oxide film 4c is about twice the film thickness of the oxide film 9.
As shown in FIG. 1-(F), after removing the nitride film 1, boron ions 11 are implanted into the substrate 10 using an ion implantation technique. At this time, a selection is made in the ion implantation or doping condition so that the previously formed oxide films 4c and 9 serve as implantation masks. Consequently, areas other than oxide films 4c and 9 are defined as P-wells.
Then, as shown in FIG. 1-(G), the substrate 10 is heat-treated within a nitrogen atmosphere. According to the heat treatment, the boron ions 11 are diffused, which forms the P-wells (PWs) 12. Thereafter, the oxide films 4c and 9 are removed, and the three wells, the lightly-N-well 5c, the N-well 20 and the P-wells 12, are completed.
However, according to the above-mentioned process, the thickness of the oxide film 4c is larger than the thickness of the oxide film 9. Thus, after removing both finally a difference in the level is generated between the P-wells 12 and the lightly-N well 5c, as indicated in a dotted circle 13 in FIG. 13-(G). If the level difference (step) is large, wire-breaking may occurs in wiring of a polysilicon or a metal, which is formed over the step. Additionally, if the level difference exceeds a focal depth in the photolithography, it becomes very difficult to form a device.
In order to decrease such a level difference between the wells, there is suggested a method in which the series of processes, the photolithography process→the ion implantation process→the oxide-film formation process, is performed twice (refer to Japanese Patent Publication No. 2795565). In this method, the second ion implantation is applied to areas outside the area where the first ion implantation is performed, and a thickness of the oxide film formed by the second oxidation is made smaller than a thickness of the oxide film formed by the first oxidation. By doing so, the level difference can be gentle two steps, which prevents the wiring extending over the level difference from being wire-broken. However, this method has a problem in that a device manufacturing process takes a long time since the series of processes, the photolithography process→the ion implantation or doping process→the oxide-film formation process, must be performed twice.

Semiconductor device having a plurality of kinds of wells and manufacturing method thereof


Disclosed are techniques for determining shroud size of a fan. The techniques receive by a computer processing system digital data of a three-dimensional representation of a shroud of an axial fan, partition the received data into a first partition corresponding to a shroud segment and a second partition corresponding to a fan segment. determine a shroud boundary ring for the shroud segment and a viewing angle of the shroud boundary ring, apply to an image of the first partition a beam shooting process to determine the shroud diameter, determine if there are pixels in the image, which have values that produce signals indicating that the pixels are coincident with portions of the shroud and when signal is detected, calculate the shroud diameter. One aspect includes using the determined should size opening for performing a flow simulation.

This description relates to computer simulation of physical processes, such as physical fluid flows.
High Reynolds number flow has been simulated by generating discretized solutions of the Navier-Stokes differential equations by performing high-precision floating point arithmetic operations at each of many discrete spatial locations on variables representing the macroscopic physical quantities (e.g., density, temperature, flow velocity). Another approach replaces the differential equations with what is generally known as lattice gas (or cellular) automata, in which the macroscopic-level simulation provided by solving the Navier-Stokes equations is replaced by a microscopic-level model that performs operations on particles moving between sites on a lattice.
Some fluid simulations involve simulating fluid flow caused by an axial cooling fan that has blades, a motor and a shroud. When a rotating mesh or local reference frame is used in computational fluid dynamics (CFD) simulations to simulate axial cooling fans, accurately defining the mesh rotating region around the fan is crucial to the accuracy and cost of the simulation. In order to achieve accuracy with low computational cost, the circular opening size of the axial fan shroud it is often necessary to determine the shroud opening size. Determining the shroud opening size for use in a numerical simulation can be a non-trivial process.
Generally, to measure a shroud circular opening size, one needs to use a geometric tool and manually pick three points. The accuracy of the opening size measurement is highly dependent on the selection of and location of these three points, which selection may introduce errors. These errors may become more significant when a shroud is digitally represented in a 3D representation is discretized, and a mesh is applied in which the shroud opening becomes less circular.
Although some tools offer a function to obtain the fan shroud circular opening size indirectly, (see for example, SIMULIA PowerDELTA® function called 'Find Mesh Holes' Dassault Systèmes SIMULIA Corp., Rising Sun Mills Providence, R.I., USA), significant errors may be present when the shroud has some special structures, such as auxiliary attachments, holes, supporters, along the circular opening which discontinue the circular profile.

Method for automatic calculation of axial cooling fan shroud circular opening size


A brake fluid pressure retaining unit is provided which allows a relief pressure to be variable only by use of a low-cost electromagnetic valve without using an expensive relief valve and orifice. The brake fluid pressure retaining unit includes an electromagnetic valve which is provided midway in a brake fluid channel connecting a master cylinder and a wheel cylinder and is capable of freely opening/closing the brake fluid channel by passing current though a solenoid coil; and an electromagnetic valve control section which detects a release signal indicative of releasing brake operation detected by a brake operation detecting section and passes current through the solenoid coil while referring to current values corresponding to a target maintaining fluid pressure to maintain a predetermined braking force. The electromagnetic valve control section determines in advance a predetermined opening-side current value required to switch the electromagnetic valve from a closed state to an open state and a predetermined closing-side current value required to switch the electromagnetic valve from an open state to a closed state, for each target maintaining fluid pressure, and performs control so that the value of the current to be passed through the solenoid coil is in a range between the predetermined opening-side current value and predetermined closing-side current value.

1. Field of the Invention
The present invention relates to a brake fluid pressure retaining unit that applies brake fluid pressure to the inside of a wheel cylinder even after the brake is released and thus maintains a predetermined brake fluid pressure so as to prevent a vehicle from moving backward (creeping down), for example, even on a steep hill.
2. Description of the Related Art
For instance, to start again a vehicle in a state of being temporarily stopped on an uphill slope such as an uphill road, a driver of a vehicle with a manual transmission (manual transmission vehicle) needs to perform troublesome operation, specifically, to cause partial clutch engagement while maneuvering a parking brake and depress an accelerator pedal to start the vehicle.
On the other hand, a vehicle with an automatic transmission (automatic transmission vehicle) is capable of providing creep force. However, for demands for improvement in fuel economy, environmental friendliness, and the like, it is required for vehicles to stop in an idle stop state or to reduce the engine idle speed. For this reason, even an automatic transmission vehicle moves backward when a driver changes pedals to depress from a brake pedal to an accelerator pedal on an uphill road, because creep force is lost or reduced.
Therefore, to prevent a vehicle from moving backward when starting the vehicle on a hill, a brake fluid pressure retaining unit has been proposed which continues to apply brake fluid pressure to the inside of a wheel cylinder even after a driver has released the depression of a brake pedal (for example, see Patent Document 1).
In this brake fluid pressure retaining unit, a brake fluid pressure circuit connecting a wheel cylinder and a master cylinder for generating brake fluid pressure according to depression force on a brake pedal caused by a driver, is provided with an electromagnetic valve capable of freely opening/closing the brake fluid pressure circuit, a relief valve for abruptly reducing the brake fluid pressure to a level where creep force is generated, and an orifice for making a decreasing rate for the brake fluid pressure inside the wheel cylinder smaller than a decreasing rate for the depression force on a brake pedal caused by a driver.
In this brake fluid pressure retaining unit, an extremely high pressure is applied to the wheel cylinder because a driver depresses a brake pedal with greater force than needed to obtain braking force. However, by use of the relief valve, the high brake fluid pressure can be abruptly reduce to a pressure that produces creep force, and further, the brake fluid pressure is gradually reduced by use of the orifice. Accordingly, when starting the vehicle on a hill, brake fluid pressure is continuously applied to the inside of the wheel cylinder after the driver releases the depression of the brake pedal until the driver starts the vehicle, thus preventing the vehicle from moving backward when it is started.
(Patent Document 1)
Japanese Patent Laid-Open No. 2000-190828 (pp 7–8, FIGS. 1 and 3)
However, in the above-described brake fluid pressure retaining unit, since a relief pressure obtained by use of the relief valve is constant, if, on a steep hill, braking force attributable to the relief pressure (brake fluid pressure) becomes less than creeping-down force due to a hill (force due to the weight of the vehicle), it will results that the vehicle moves backward. Moreover, in this brake fluid pressure retaining unit, the relief valve and the orifice are needed in addition to the electromagnetic valve. Further, pressure reduction characteristics at the time of slow release (i.e., when fluid pressure is slowly reduced) depend on the orifice (throttle) and are constant. Furthermore, the orifice is very difficult to manage during a manufacturing process and also expensive.
In this brake fluid pressure retaining unit in particular, since a spring provided in the relief valve produces a constant spring force and the diameter of the orifice is constant, only a constant relief pressure can be produced even when the gradient of a hill changes. Therefore, a need to quickly reduce the fluid pressure depending on the angle of inclination cannot be met. For instance, on a downhill slope, a driver wants to quickly reduce the brake fluid pressure but cannot do so actually, and as a result, drag occurs.
Moreover, it is also conceivable that the relief pressure is variably controlled by use of a solenoid valve. However, according to a conventional and general solenoid control method, the voltage value is duty cycle controlled periodically, and accordingly, the following problems arise. As shown in FIG. 9, when the voltage value is duty cycle controlled and the current value is controlled to be constant, it is difficult to maintain a constant oil pressure. That is, when the current value is intended to be constant, as can be seen from FIG. 9, the current value may become both a value that causes an electromagnetic valve to open and a value that causes the electromagnetic valve to close, and accordingly, the solenoid valve will be either in an open state or closed state depending on the state of the electromagnetic valve.
That is to say, when the current value is made constant based on the state of the electromagnetic valve before controlled, the maintaining oil pressure is greatly affected by this fact, and a balance is caught at a low value of maintaining oil pressure that brings the electromagnetic valve in a closed state. In the case of the balance at this value of maintaining oil pressure, when the electromagnetic valve is desired to be switched from a closed state to an open state, and again to a closed state (i.e., when the maintaining oil pressure is desired to be slightly lowered), the maintaining oil pressure is in some cases excessively reduced more than needed to make the electromagnetic, which has been once brought in an open state, return to a closed state. Such a problem is caused by the fact that the current value is controlled by performing periodical duty cycle control of the voltage value, and accordingly, instantaneous response ability of the current value is affected by the self-heating of the electromagnetic valve and the like.