Patents by Inventor Kazuyuki Tamanoi

Kazuyuki Tamanoi 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).

  • Positioning control system including a servo-error signal generating circuit
    Patent number: 5930212
    Abstract: A positioning control system for performing recording/reproducing operations by irradiating an optical beam to a predetermined position on an optical recording medium, includes a photo-detector and a servo-error signal generating circuit which can generate at least one servo-error signal in accordance with a difference between the detection currents.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: July 27, 1999
    Assignee: Fujitsu Limited
    Inventors: Akira Minami, Shigeyoshi Tanaka, Michio Matsuura, Hiromichi Kuwano, Kazuyuki Tamanoi
  • Positioning control system which generates a servo-error signal in accordance with a difference between detection currents
    Patent number: 5909415
    Abstract: A positioning control system for performing recording/reproducing operations by irradiating an optical beam to a predetermined position on an optical recording medium, e.g., magneto-optical disk. The control system includes a photo-detector constituted by at least two-divisional units, and a servo-error signal generating circuit which can generate at least one servo-error signal in accordance with a difference between the detection currents. Preferably, the servo-error signal generating circuit includes at least one division circuit that has two pairs of transistors, two emitters in each pair of transistors being connected together into a common emitter, bias voltages of a direct current type being applied to the respective bases of transistors on one side, and the respective collectors of the transistors on one side being connected to a common connecting portion via resistors.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: June 1, 1999
    Assignee: Fujitsu Limited & Texas Instruments Japan
    Inventors: Akira Minami, Shigeyoshi Tanaka, Michio Matsuura, Hiromichi Kuwano, Kazuyuki Tamanoi
  • Positioning control system having an optical beam and a servo-error signal generating circuit for accurately irradiating a desired position
    Patent number: 5812503
    Abstract: A positioning control system for performing recording/reproducing operations by irradiating an optical beam on a predetermined position on an optically recording medium includes a photo-detector constituted by at least two-divisional units and a servo-error signal generating circuit which can generate at least one servo-error signal in accordance with a difference between detection currents measured at the collectors of selected transistors in two pairs of transistors.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: September 22, 1998
    Assignee: Fujitsu Limited
    Inventors: Akira Minami, Shigeyoshi Tanaka, Michio Matsuura, Hiromichi Kuwano, Kazuyuki Tamanoi
  • Positioning control system utilizing optical beam having servo-error signal generating circuit
    Patent number: 5636191
    Abstract: A positioning control system for performing recording/reproducing operations by irradiating an optical beam to predertermined position on an optically recording medium, e.g., magneto-optical disk, includes a photo-detector constituted by at least two-divisional units; and a servo-error signal generating circuit which can generate at least one servo-error signal in accordance with a difference between the detection currents.
    Type: Grant
    Filed: April 13, 1995
    Date of Patent: June 3, 1997
    Assignees: Fujitsu Limited, Texas Instruments Japan Limited
    Inventors: Akira Minami, Shigeyoshi Tanaka, Michio Matsuura, Hiromichi Kuwano, Kazuyuki Tamanoi
  • Positioning control system utilizing optical beam
    Patent number: 5566143
    Abstract: A positioning control system for performing recording/reproducing operations by irradiating an optical beam to predetermined position on an optically recording medium, e,g., magneto-optical disk, includes a photo-detector constituted by at least two-divisional units; and a servo-error signal generating circuit which can generate at least one servo-error signal in accordance with a difference between the detection currents.
    Type: Grant
    Filed: July 22, 1993
    Date of Patent: October 15, 1996
    Assignee: Fujitsu Limited
    Inventors: Akira Minami, Shigeyoshi Tanaka, Michio Matsuura, Hiromichi Kuwano, Kazuyuki Tamanoi