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: 7721169
    Abstract: A scanning circuit has path switches connected between a plurality of data flip-flop circuits of the scanning circuit for sequentially reading an output signal in synchronism with a clock. A plurality of control signal lines select the path switches to arbitrarily skip reading of the flip-flop circuits that do not require the scanning circuit and always fix a potential of the skipped data flip-flop circuit. Only the arbitrary data is read, and in the case where unnecessary data exists, reading is skipped, to thereby increase the read rate.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: May 18, 2010
    Assignee: Seiko Instruments Inco.
    Inventors: Masahiro Yokomichi, Satoshi Machida, Yoshihiro Shibuya, Yukito Kawahara, Minoru Ariyama
  • Patent number: 7394054
    Abstract: A photoelectric converter capable of reducing random noise has a photoelectric conversion circuit that generates an optical signal in correspondence to incident light, a reset circuit connected to an output terminal of the photoelectric conversion circuit, and a first amplification circuit connected to output terminals of the photoelectric conversion circuit and the reset circuit. A first electric charge transfer unit has a terminal connected to an output terminal of the amplification circuit and a terminal connected to a first capacitor. Second and third electric charge transfer units have terminals connected to second and third amplification circuits and other terminals connected to second and third capacitors, and the second and third amplification circuits are connected to the first and second capacitors, respectively.
    Type: Grant
    Filed: August 9, 2006
    Date of Patent: July 1, 2008
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara
  • Publication number: 20060266932
    Abstract: The invention provides a photoelectric converter capable of reducing a random noise. The photoelectric converter includes: a photoelectric conversion unit having an output terminal connected to input terminals of a reset unit and an amplification unit; a hold unit for holding a reference signal generated through resetting of the output terminal of the photoelectric conversion unit; and a signal read unit for reading out to a common signal line the reference signal and an optical signal obtained after storage of electric charges generated on the basis of light made incident to a photoelectric conversion area of the photoelectric conversion unit.
    Type: Application
    Filed: August 9, 2006
    Publication date: November 30, 2006
    Inventors: Satoshi Machida, Yukito Kawahara
  • Patent number: 7102115
    Abstract: A photoelectric converter capable of reducing random noise comprises a photoelectric conversion circuit for generating an optical signal in correspondence to incident light, a reset circuit connected to an output terminal of the photoelectric conversion circuit, and an amplification circuit connected to output terminals of the photoelectric conversion circuit and the reset circuit. An electric charge transfer unit has one terminal connected to an output terminal of the amplification circuit and another terminal connected to a capacitor. A source follower amplifier has a gate connected to the electric charge transfer unit and the capacitor, and a channel selection circuit is connected to a source of the source follower amplifier. A common signal line is connected to an output terminal of the channel selection circuit, a first current source is connected to the common signal line, and a second current source is connected to the source of the source follower.
    Type: Grant
    Filed: February 23, 2004
    Date of Patent: September 5, 2006
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara
  • Patent number: 7015449
    Abstract: A linear image sensor comprises linear image sensor ICs each having light receiving elements arranged according to a preselected resolution level for outputting output signals in accordance with an amount of light received. Switch elements interconnect output terminals of adjacent two or more of the light receiving elements for switching between the preselected resolution level of the light receiving elements to at least one other resolution level constituting a fraction of the preselected resolution level. First amplifier circuits are is connected to output terminals of the light receiving elements. Sample and hold circuits temporarily hold outputs of the first amplifier circuits. Second amplifier circuits are connected to output terminals of the sample and hold circuits. Reading switch elements read outputs of the second amplifier circuits. Scanning circuits control the reading switch elements.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: March 21, 2006
    Assignee: Seiko Instruments Inc.
    Inventors: Masahiro Yokomichi, Satoshi Machida, Yukito Kawahara
  • Patent number: 6941002
    Abstract: A fingerprint reading system is provided, which is capable of enhancing versatility when actually used, increasing productivity and reducing costs. An illumination device emits the light from a rear surface side of an active matrix liquid crystal cell. A light guiding plate provided on a surface side of the active matrix liquid crystal cell, transmits the light coming from the rear surface side and deflects the light coming from the surface side toward one side end surface. A light receiving device provided on the side of one side surface of the light guiding plate receives the light exiting from this one side surface. A drive circuit makes the active matrix liquid crystal cell pinpoint-irradiate a fingerprint in contact with the light guiding plate by pinpointing with the light emitted from the illumination device and makes the light receiving device pinpoint-receive the light reflected by the fingerpoint, thereby obtaining an image of the fingerprint.
    Type: Grant
    Filed: August 8, 2000
    Date of Patent: September 6, 2005
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Hiroyuki Fujita, Tsutomu Matsuhira
  • Publication number: 20050035273
    Abstract: The invention provides a photoelectric converter capable of reducing a random noise. The photoelectric converter includes: a photoelectric conversion unit having an output terminal connected to input terminals of a reset unit and an amplification unit; a hold unit for holding a reference signal generated through resetting of the output terminal of the photoelectric conversion unit; and a signal read unit for reading out to a common signal line the reference signal and an optical signal obtained after storage of electric charges generated on the basis of light made incident to a photoelectric conversion area of the photoelectric conversion unit.
    Type: Application
    Filed: February 23, 2004
    Publication date: February 17, 2005
    Inventors: Satoshi Machida, Yukito Kawahara
  • Patent number: 6803957
    Abstract: To eliminate after-image due to residual charges to provide an output form that is easy to obtain effective on-light output. The outputs of photo-diodes 1 are read out as sequential signal outputs on a common signal line 15 through connected amplifiers 3, and two states of before and after resetting the photo-diodes 1 are outputted in order for each light receiving element.
    Type: Grant
    Filed: January 26, 1999
    Date of Patent: October 12, 2004
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Masahiro Yokomichi, Yukito Kawahara
  • Patent number: 6643038
    Abstract: A low-priced contact type color image sensor formed without the need to provide color filters on a linear image sensor. The color filters are formed on a surface of a document side of a transparent protective glass in direct contact with a document for flattening the light irradiation surface, such that the pitch thereof is equal to that of light receiving elements of a linear image sensor.
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: November 4, 2003
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Masahiro Yokomichi
  • Patent number: 6618086
    Abstract: A linear image sensor using phototransistors as light receiving elements has improved after-image characteristics and reduced production costs by providing a light-receiving MOS diode proximate each photosensor, placing the MOS diode in an inversion state during the accumulation of photo-charge so that the accumulated photo-charge is accumulated at a base region of the phototransistors, placing the MOS diode in an accumulating state during a reset operation to return the phototransistors to an initial state after a readout operation has been performed, so that residual charge without reading out is transferred to the base region of the phototransistors and an after-image caused by residual charge is reduced through an emitter of the phototransistors.
    Type: Grant
    Filed: April 24, 1998
    Date of Patent: September 9, 2003
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Tooru Shimizu, Satoshi Machida, Masahiro Yokomichi
  • Publication number: 20030156105
    Abstract: A scanning circuit has path switches connected between a plurality of data flip-flop circuits of the scanning circuit for sequentially reading an output signal in synchronism with a clock. A plurality of control signal lines select the path switches to arbitrarily skip reading of the flip-flop circuits that do not require the scanning circuit and always fix a potential of the skipped data flip-flop circuit. Only the arbitrary data is read, and in the case where unnecessary data exists, reading is skipped, to thereby increase the read rate.
    Type: Application
    Filed: February 14, 2003
    Publication date: August 21, 2003
    Inventors: Masahiro Yokomichi, Satoshi Machida, Yoshihiro Shibuya, Yukito Kawahara, Minoru Ariyama
  • Publication number: 20030155483
    Abstract: An image sensor is provided in which a read rate can be increased and missing of data of the output signal of a light receiving element can be eliminated. There are disposed switch elements that connect the output terminals of all of a plurality of light receiving elements that output an output signal in accordance with the amount of received light. The switch elements are arbitrarily conductive connective in accordance with 1/n of the highest resolution from the highest resolution, and the output of the average value is held in respective sample/hold circuits at the plural same potential, to thereby read only arbitrary data in accordance with the resolution at the time of reading. In the case where there are unnecessary data, the data is skipped so as to increase a read rate and eliminate missing of data of the output signals of the light receiving elements.
    Type: Application
    Filed: February 14, 2003
    Publication date: August 21, 2003
    Inventors: Masahiro Yokomichi, Satoshi Machida, Yukito Kawahara
  • Patent number: 6545776
    Abstract: According to the present invention, there is provided an image sensor for receiving light reflected from an original copy on which the light has been irradiated and for converting the received light into electrical signals, the image sensor having a simple configuration, no residual image, a small fluctuation in the dark outputs, and a good S/N ratio. In order to achieve such an image sensor, an output terminal of a photodiode is reset to a constant voltage, and an image signal output of the photodiode and the reference voltage output immediately after the photodiode is reset are performed succeedingly, using a clamping circuit.
    Type: Grant
    Filed: November 13, 1998
    Date of Patent: April 8, 2003
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara, Masahiro Yokomichi
  • Patent number: 6512604
    Abstract: The present disclosure relates to a color image reading device that successively switches three color light sources to irradiate the color original copy and successively reads information on the original using a monochrome image sensor, and which is featured by simple construction and less reading time period. A plurality of image sensor ICs are linearly mounted. A start pulse output terminal of an anterior stage image sensor IC is connected to a start pulse input terminal of a posterior stage image sensor IC, thereby forming an image sensor block. A plurality of those image sensor blocks are provided such that start pulse input terminals of initial stage image sensor ICs in all blocks are connected together. By inputting start pulses to the terminals connected together, image signal outputs are read out simultaneously.
    Type: Grant
    Filed: December 16, 1998
    Date of Patent: January 28, 2003
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara, Masahiro Yokomichi
  • Patent number: 6468825
    Abstract: A method for producing a semiconductor temperature sensor comprises the steps of forming PNP bipolar transistors and PMOS transistors so that a base region of each of the PNP bipolar transistors and a corresponding N-well region of each of the PMOS transistors are formed at the same time, and connecting the PNP bipolar transistors in a Darlington connection.
    Type: Grant
    Filed: February 11, 2000
    Date of Patent: October 22, 2002
    Assignee: Seiko Instruments Inc.
    Inventors: Satoshi Machida, Yukito Kawahara, Kentaro Kuhara, Toru Shimizu, Yoshikazu Kojima
  • Patent number: 6462563
    Abstract: A fingerprint reading system is provided with enhanced versatility and reduced cost. The fingerprint reading sensor includes a group of first electrodes arranged in a plurality of lines extending in a first direction, a group of second electrodes arranged in a plurality of lines extending in a second direction intersecting the first direction above the first electrode group through an interlayer insulating film, and a surface protective film formed of a dielectric material provided on the second electrode group. Drive circuits detect electrostatic capacity between each of the electrodes and a finger touching the surface protective film by sequentially applying a predetermined voltage to both groups of electrodes and measuring a change in the electrostatic capacity at each point where a second electrode crosses over a first electrode.
    Type: Grant
    Filed: August 11, 2000
    Date of Patent: October 8, 2002
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Hiroyuki Fujita, Tsutomu Matsuhira
  • Patent number: 6429413
    Abstract: To eliminate a residual image due to residual charge in an image sensor circuit and provide an effective bright-time output, the image sensor is provided with a reset switch connected to a photodiode. After the potential of the photodiode is held through a first amplifier in two holding circuits as an image signal and an initial signal, the initial signal and the image signal are sequentially output through a second amplifier. By resetting the photodiode to a desired potential to produce an initial signal, a residual image can be eliminated.
    Type: Grant
    Filed: October 20, 1999
    Date of Patent: August 6, 2002
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Masahiro Yokomichi, Kenji Yoshida
  • Publication number: 20020090211
    Abstract: An apparatus for implementing readout of a fingerprint irradiates a fingertip with light via a transparent base plate. When implementing touch-and-move of the finger on the transparent base plate, an image sensor of a slim piece implements readout of reflected light formed by the asperity of the fingerprint.
    Type: Application
    Filed: December 12, 2001
    Publication date: July 11, 2002
    Inventor: Yukito Kawahara
  • Patent number: 6401551
    Abstract: A fingerprint reading device is provided, which is capable of enhancing a versatility when actually used, increasing a productivity and reducing costs. The fingerprint reading device comprises an electrostatic capacity type fingerprint reading sensor provided on a liquid crystal panel, and drive circuits thereof. The fingerprint reading sensor includes detection electrodes arranged in predetermined positions, active elements connected respectively to the detection electrodes, and a protective film provided on the surface thereof.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: June 11, 2002
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Hiroyuki Fujita, Tsutomu Matsuhira
  • Patent number: 6327057
    Abstract: To reduce current consumption in a contact type linear image sensor of a multi-chip form, a control circuit controls a clock buffer circuit of the device so that the clock buffer is activated only when a picture signal from a corresponding linear image sensor IC is output. The control circuit inputs a control signal, operates the clock buffer, and drives a shift register when a picture signal is to be read out.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: December 4, 2001
    Assignee: Seiko Instruments Inc.
    Inventors: Yukito Kawahara, Satoshi Machida, Masahiro Yokomichi