Patents by Inventor Yukito Kawahara

Yukito Kawahara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6303919
    Abstract: A light receiving element is provided with a phototransistor and a light receiving MOS diode proximate thereto and having a gate electrode covering a portion of the base region of the phototransistor. The gate electrode permits transmission of a portion of received light. The light receiving MOS diode forms an inversion layer in a substrate adjacent the base of a phototransistor during the time photo charges are stored, and generated photo charges are stored in the inversion region and the base region of the phototransistor. During the storage state, the potential of the inversion region and the base region of the phototransistor is limited, so that the intensity of an electric field applied to an insulating film between the electrode and the semiconductor substrate is 0.7 MV/cm or less. Alternatively, the potential of the electrode in a waiting state is fixed or made floating, so that an electric field is not applied, and recombination at the surface of the semiconductor substrate is made stable.
    Type: Grant
    Filed: April 26, 1999
    Date of Patent: October 16, 2001
    Assignee: Seiko Instruments Inc.
    Inventors: Masahiro Yokomichi, Yukito Kawahara, Satoshi Machida, Tooru Shimizu
  • Patent number: 6291810
    Abstract: A voltage at an output terminal of a photodiode is reset to a fixed voltage and an output signal of the photodiode and a dummy signal matching a dark output signal is output by a dummy photodiode comprising an identical component as that of the photodiode. The voltage difference between an input side and an output side of an amplifier is made to match the difference between a reset voltage of the photodiode and a reset voltage of a common signal line and a reset voltage of an output terminal to optimize the size of a MOS transistor forming the amplifier. The offset voltage is set to a constant which does not depend on the size of the MOS transistor. The amplifier is formed with CMOS devices and is selectively operated only during an output operation to suppress the current consumption.
    Type: Grant
    Filed: April 26, 1999
    Date of Patent: September 18, 2001
    Assignee: Seiko Instruments Inc.
    Inventors: Masahiro Yokomichi, Yukito Kawahara, Satoshi Machida
  • Patent number: 6285047
    Abstract: A linear image sensor IC comprising a plurality of switching circuits each connected to a plurality of light receiving elements in series; scanning circuits for sequentially switching said switching circuits; and driving circuits for operating said scanning circuits, wherein a LOCOS isolation layer is formed between an edge in the main scanning direction of the linear image sensor IC which is closest to an array of the light receiving elements and a light receiving portion of the light receiving element. The inventive image sensor IC is mounted by devising so that the circuit can be put into a thin and long pattern in the scanning direction, so that the chip having a width thinner than a thickness thereof which had been beyond expectation by the prior art can be realized. The use of this very thin IC allows a compact IC assembling substrate having less fluctuation among ICs to be manufactured at low cost.
    Type: Grant
    Filed: March 20, 1996
    Date of Patent: September 4, 2001
    Assignee: Seiko Instruments, Inc.
    Inventors: Satoshi Machida, Yukito Kawahara, Masahiro Yokomichi, Yoshikazu Kojima, Noritoshi Ando
  • Patent number: 6046492
    Abstract: A semiconductor temperature sensor comprises independent current sources and bipolar transistors connected to form a Darlington circuit. The bipolar transistors have electrodes each connected to one of the current sources. An output voltage of the semiconductor temperature sensor is adjusted by trimming a current value of at least one of the current sources.
    Type: Grant
    Filed: September 12, 1996
    Date of Patent: April 4, 2000
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara, Kentaro Kuhara, Toru Shimizu, Yoshikazu Kojima
  • Patent number: 5665960
    Abstract: A photoelectric converter device having improved residual image characteristics and composed of a transistor having a control electrode region made of a semiconductor of a first conductivity type for accumulating carriers generated by an electromagnetic wave emitted by an object to be detected, a first main electrode region made of a semiconductor of a second conductivity type, and a second main electrode region made of a semiconductor of the second conductivity type, for performing an operation to accumulate the carriers, an operation of reading signals based on the carriers, and an operation of extinguishing the carriers, wherein carriers other than those generated by the electromagnetic wave emitted by the object to be detected are generated in or injected into the control electrode region. Thus, since the amount of excess majority carriers in the control electrode region after the extinguishing operation is always kept substantially constant, improved residual image characteristics are obtained.
    Type: Grant
    Filed: March 20, 1996
    Date of Patent: September 9, 1997
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara, Masahiro Yokomichi, Yoshikazu Kojima
  • Patent number: 5619345
    Abstract: An image sensor of the contact type is comprised of a plurality of image sensor chips arranged linearly with one another. Each chip has an array of picture elements arranged at a given constant pitch which is set slightly smaller than a standard reading pitch in a main scanning direction, thereby ensuring uniform output performance of the image sensor.
    Type: Grant
    Filed: July 16, 1991
    Date of Patent: April 8, 1997
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara, Hiroshi Mukainakano, Masahiro Yokomichi
  • Patent number: 5426060
    Abstract: A method of inspecting and a method of manufacturing image sensors formed on a surface of a semiconductor wafer. A semiconductor wafer is provided having image sensors formed on its surface. Grooves are cut at boundaries between image sensors to be inspected, so that each groove has a depth that is smaller than the thickness of the semiconductor wafer. The grooves are cut in the boundaries between the image sensors so that photoN sensing carriers generated in the boundary regions, that are not generated by the image sensor being inspected, do not affect the inspection of the image sensor. The characteristics of the image sensors are inspected before cutting through the semiconductor wafer to form individual image sensors. Thus, in accordance with the present invention, the electrical characteristics of the image sensors can be accurately ascertained either before or after separation from the semiconductor wafer.
    Type: Grant
    Filed: September 2, 1992
    Date of Patent: June 20, 1995
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Hiroshi Mukainakano, Masahiro Yokomichi, Masato Higashi
  • Patent number: 5329149
    Abstract: An improved image sensor comprises a plurality of photo-sensing elements each comprising an impurity diffusion layer formed in a surface of a semiconductor substrate and arrayed linearly. The photo-sensing elements are of an opposite conductivity type than that of the semiconductor substrate. A transparent insulating film is formed on the photo-sensing elements and the surface of the semiconductor substrate. A non-light transmitting shading film is formed over the transparent insulating film and has photo-sensing windows which overlay a part of each of the photo-sensing elements. The shape and area of each of the photo-sensing elements is equal. The area of each of the photo-sensing windows is equal, but the shape of the first and last photosensing windows is different from that of the remaining photosensing windows. By this arrangement, the amount of photoexcited carriers generated is uniform at all photo-sensing regions, since the area of all photo-sensing windows is equal.
    Type: Grant
    Filed: October 11, 1991
    Date of Patent: July 12, 1994
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Hiroshi Mukainakano, Masahiro Yokomichi, Masato Higashi
  • Patent number: 5321303
    Abstract: A method for manufacturing a semiconductor device using inclined stage of a dicing saw in order to cut the semiconductor substrate obliquely with respect to the depthwise direction. When a plurality of semiconductor chips diced obliquely are connected, a degree of connecting accuracy is increased, and it is possible to realize a contact-type image sensor of high resolving power and high accuracy.
    Type: Grant
    Filed: April 17, 1992
    Date of Patent: June 14, 1994
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Hiroshi Mukainakano, Satoshi Machida
  • Patent number: 5198654
    Abstract: The image reading apparatus is of the multi-chip line sensor having a plurality of photoelectric conversion elements connected through corresponding switching elements commonly to every one another. Each group of the commonly connected photoelectric conversion elements outputs on a common line an image signal which is then fed to a sample hold circuit and is thereafter outputted from a single output terminal. By such construction, the image signal from the photoelectric conversion elements is sequentially outputted externally from the single output terminal in the form of output waveshape as held in the sample hold circuit in such manner as to prolong output duration of each bit image signal to thereby enable fast operation of the line sensor.
    Type: Grant
    Filed: March 8, 1991
    Date of Patent: March 30, 1993
    Assignee: Seiko Instruments Inc.
    Inventors: Hiroshi Mukainakano, Yukito Kawahara, Satoshi Machida
  • Patent number: 5151587
    Abstract: The image sensor is comprised of an array of operative bipolar transistors. Another array of optically shielded dummy bipolar transistors are formed adjacently to the operative bipolar transistors. Reset switches are connected to base regions of the operative and dummy bipolar transistors so as to reduce variation in dark image output, to ensure linearity of output signal, and to eliminate image storage.
    Type: Grant
    Filed: January 4, 1991
    Date of Patent: September 29, 1992
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara, Hiroshi Mukainakano
  • Patent number: 5146074
    Abstract: The solid state imaging device having an array of bit units formed in a semiconductor substrate. Each bit unit is comprised of a phototransistor having a collector formed of the semiconductor substrate an emitter and a base, a switching transistor of the MOS type having a drain connected to the emitter of the phototransistor, an initializing transistor of the MOS type having a drain connected to the base of the phototransistor, a source receptive of a first reference voltage, and a gate connected to the emitter of the phototransistor, and a resetting transistor of the MOS type having a drain connected to the emitter of the phototransistor, a source receptive of a second reference voltage, and a gate receptive of a reset signal. The resetting transistor operates in the reset signal to enable the initializing transistor to initialize the phototransistor. The switching transistor drives the initialized phototransistor to effect reading of image.
    Type: Grant
    Filed: August 8, 1991
    Date of Patent: September 8, 1992
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Hiroshi Mukainakano, Masahiro Yokomichi
  • Patent number: 5119156
    Abstract: A photo-detecting element is covered with a passivation film having an uneven surface to avoid multi-reflection for the monochromatic incident light. The uneven film transmits the same intensity of incident light even if the mean thickness of uneven film is not constant over the entire surface of a semiconductor substrate.
    Type: Grant
    Filed: September 1, 1988
    Date of Patent: June 2, 1992
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Hiroshi Mukainakano
  • Patent number: 5109440
    Abstract: A plurality of opto-electro conversion elements are arranged integrally in a row to constitute a line image sensor to produce respective image bit signals. A plurality of switching elements are connected to the corresponding conversion elements and switchable between on and off states to read out the corresponding bit image signals. A scanning circuit scans sequentially the switching elements to successively turn on them to thereby effect the sequential reading of bit image signals. An initiating circuit is connected to the scanning circuit for generating an initiating signal effective to initiate the scanning circuit. An ending circuit is also connected to the scanning circuit and operates after the switching element of last stage is turned off for generating an ending signal indicative of the ending of scanning operation for one line. A control circuit receives the initiating and ending signals and produces a control signal.
    Type: Grant
    Filed: May 26, 1989
    Date of Patent: April 28, 1992
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Hiroshi Mukainakano
  • Patent number: 5109155
    Abstract: The semiconductor image sensing device is comprised of a single crystal substrate of one conductivity type, formed thereon with an array of photodetector 5 for effecting photo-electric conversion, a read-out circuit for sequentially reading out an output signal from each photodetector, an amplifier for voltage-converting the read output signal, and a voltage regulator for providing a constant voltage. The read-out circuit and the photodetectors are driven by a lower voltage supplied from the integrated voltage regulator so as to reduce a switching noise generated in the read-out circuit. S/N ratio of the semiconductor image sensor is improved by reducing the switching noise. Further, the power consumption can be saved by driving the read-out circuit at the lower voltage.
    Type: Grant
    Filed: July 23, 1990
    Date of Patent: April 28, 1992
    Assignee: Seiko Instruments Inc.
    Inventors: Hiroshi Mukainakano, Yukito Kawahara, Satoshi Machida
  • Patent number: 5060084
    Abstract: A semiconductor device for image sensing and printing comprises an integrated circuit composed of a single semiconductor substrate on which are integrated a linear array of phototransistors, driving circuits and control circuits. The control circuits are operable in a read mode for processing output signals from the phototransistors to enable transmission thereof to an external device and are operable in a print mode for processing inputted image data signals to produce printing signals which are applied to the driving circuits for use in driving an external printing device.
    Type: Grant
    Filed: December 23, 1988
    Date of Patent: October 22, 1991
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Hiroshi Mukainakano, Masato Higashi
  • Patent number: 4992653
    Abstract: The image sensor of the linear type includes a plurality of photoelectric conversion elements, switching elements each having an input terminal connected to each photoelectric conversion element and an output terminal for reading out a detection signal produced from the corresponding photoelectric conversion element, and a scanning circuit for sequentially driving the switching elements. A first common line is connected to output terminals of odd-numbered switching elements. A second common line is connected to output terminals of even-numbered switching elements. A first reading gate has an output terminal and an input terminal connected to the first common line. A first reset gate has an output terminal and an input terminal connected to the first common line. A second reading gate has an output terminal and an input terminal connected to the second common line. A second reset gate has an output terminal and an input terminal connected to the second common line.
    Type: Grant
    Filed: April 16, 1990
    Date of Patent: February 12, 1991
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Hiroshi Mukainakano
  • Patent number: 4928095
    Abstract: An active matrix-addressed picture display device comprises a matrix of picture elements arranged in a row-by-column matrix, each picture element comprising a liquid crystal cell, a single capacitor for holding a signal voltage to be applied to the liquid crystal cell, and a single switching transistor for enabling a signal voltage to be applied to the capacitor. Column signal supply electrodes are connected to apply signal voltages to the columns of switching transistors, and row address electrodes are connected to apply scanning voltages to the rows of switching transistors. To eliminate shorting between the substrate and the column and row electrodes, one side of the capacitors in each row of picture elements are connected to a preceding row address electrode of a neighboring row of picture elements.
    Type: Grant
    Filed: December 16, 1983
    Date of Patent: May 22, 1990
    Assignee: Seiko Instruments Inc.
    Inventor: Yukito Kawahara
  • Patent number: 4906856
    Abstract: A photoelectric conversion array is comprised of a longitudinal semiconductor substrate formed with a plurality of doped regions electrically isolated from one another and equidistantly aligned in the longitudinal direction of the substrate.
    Type: Grant
    Filed: March 23, 1988
    Date of Patent: March 6, 1990
    Assignee: Seiko Instruments Inc.
    Inventors: Eiichi Iwanami, Yukito Kawahara, Hiroshi Mukainakano
  • Patent number: 4901153
    Abstract: A photo-electro conversion sensor of the image sensor is covered with a single layer passivation film or a multi-layer passivation film composed of plural layers having the substantially same refractive indexes, and the thickness of the passivation film is arranged some ten times as much as the wavelength of incident light so as to eliminate interference.
    Type: Grant
    Filed: August 2, 1988
    Date of Patent: February 13, 1990
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara, Hiroshi Mukainakano