Patents by Inventor Keizo Kurahashi

Keizo Kurahashi 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: 4550310
    Abstract: A new type touch sensing device comprises a touch panel with a plurality of transparent touch electrodes, a LC parallel resonant circuit connected to the touch electrode and an oscillation circuit. The LC resonant circuit has a resonant point on a same frequency with the oscillation frequency of the oscillation circuit. The touch/non-touch condition to the touch electrode is detected as a change of voltage value at the connecting point of the LC resonant circuit and touch electrode with an increased ON-OFF ratio.
    Type: Grant
    Filed: October 28, 1982
    Date of Patent: October 29, 1985
    Assignee: Fujitsu Limited
    Inventors: Hisashi Yamaguchi, Toru Asano, Kazuhiro Takahara, Keizo Kurahashi, Shizuo Andoh
  • Patent number: 4523189
    Abstract: A thin-film EL display device incorporates a MOS active matrix. Each of the MOS transistor arrays is additionally provided in parallel with a Zener diode for the purpose of protecting the device from a high voltage. This Zener diode has a breakdown voltage characteristic corresponding to a difference between a luminous voltage and a non-luminous voltage of an EL display element and clamps the voltage across the MOS transistor, in the "OFF" state, to a voltage less than or equal to non-recoverable breakdown voltage.
    Type: Grant
    Filed: May 21, 1982
    Date of Patent: June 11, 1985
    Assignee: Fujitsu Limited
    Inventors: Kazuhiro Takahara, Keizo Kurahashi, Hiroyuki Gondo, Kenichi Oki, Shoshin Miura
  • Patent number: 4458244
    Abstract: An improved driving system for write operations into shift rows in a multi-row self shift type gas discharge panel. Each shift row is composed of at least one shift channel comprising a regular arrangement of plural shift discharge cells and which is provided with a write electrode which defines a write discharge cell at one end of the shift channel. To the write electrodes of the shift rows, the write voltage pulse is supplied in common. When applying the write voltage pulse to the write electrode of a selected shift row, a shift voltage pulse which is the same in polarity as said write voltage pulse and has an equivalent or greater time width than said write voltage pulse is applied to the shift electrode opposing the write electrodes of the non-selected shift rows, and as a result, erroneous discharges, namely, over-write to the adjacent shift discharge cells, can be avoided by preventing the discharge of the write discharge cells of the non-selected shift rows.
    Type: Grant
    Filed: April 29, 1981
    Date of Patent: July 3, 1984
    Assignee: Fujitsu Limited
    Inventors: Hisashi Yamaguchi, Kazuo Yoshikawa, Keizo Kurahashi
  • Patent number: 4456909
    Abstract: A method for driving a thin film EL display device comprising the steps of clamping the Y side scanning electrodes selectively and sequentially to a reference voltage and applying the display voltage selectively from the X side data electrodes. In addition, the non-display voltage which is lower than the display threshold voltage, is applied to the non-selected data electrodes and the non-selected scanning electrodes are floated. This new driving method reduces drive power and widens the device operating voltage range.
    Type: Grant
    Filed: June 29, 1981
    Date of Patent: June 26, 1984
    Assignee: Fujitsu Limited
    Inventors: Kazuhiro Takahara, Keizo Kurahashi, Hisashi Yamaguchi
  • Patent number: 4368467
    Abstract: A new type flat panel display device has the structure combining a plurality of solid state display modules corresponding to character blocks. Each module is assembled using, as the basic element, a semiconductor substrate integrating circuit elements for driving and circuits for addressing, and moreover, it is provided with a memory element for a selection signal in view of making possible access to each module.
    Type: Grant
    Filed: February 20, 1981
    Date of Patent: January 11, 1983
    Assignee: Fujitsu Limited
    Inventors: Tomoyuki Unotoro, Kunihiro Tanikawa, Keizo Kurahashi, Hisashi Yamaguchi, Yuichiro Ito, Yoshihiro Miyamoto
  • Patent number: 4139803
    Abstract: In conjunction with an AC plasma display panel a light detecting pen is employed to designate coordinate points on the panel. Circuitry is employed to scan the electrodes of the panel with sustain voltage pulses at predetermined intervals and determine the coincidence of a selectively applied sustain voltage pulse with light detected by the light pen to indicate the location of the light pen with respect to the panel. A negative scanning method is also disclosed wherein coincidence between a sustain voltage pulse which is selectively not applied and the non-detection of light indicates the location.
    Type: Grant
    Filed: November 12, 1976
    Date of Patent: February 13, 1979
    Assignee: Fujitsu Limited
    Inventors: Keizo Kurahashi, Michihiro Shimizu, Shizuo Andoh, Kazuo Yoshikawa