Patents by Inventor Kazuhito Yokoyama

Kazuhito Yokoyama 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: 6563768
    Abstract: A magneto-optical memory device includes a first unit projecting a light beam onto a desired position on a recording medium, and a second unit applying a magnetic field to a position onto which the light beam is projected. The second unit applies, to the recording medium, a predetermined magnetic field within a magnetic field intensity range wherein a rate of change of a reproduced signal amplitude at the time of reproduction with respect to a magnetic field intensity becomes large. The relative positions of the second unit and the first unit are adjusted in accordance with a reproduced signal amplitude thus obtained.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: May 13, 2003
    Assignee: Fujitsu Limited
    Inventors: Yasukiyo Kunimatsu, Kazuhito Yokoyama
  • Patent number: 6501710
    Abstract: Disclosed herein is an optical storage device having an objective lens actuator for moving an objective lens in a focusing direction. The objective lens actuator includes an actuator base fixed to a carriage movable in the radial direction of an optical disk, a lens holder for holding the objective lens, and a supporting mechanism for elastically supporting the lens holder to the actuator base. The actuator base has an elongated hole extending in the radial direction of the optical disk. A relative position between the actuator base and the carriage is adjusted so that the tilt of the optical axis of the objective lens in the radial direction of the optical disk occurring in displacing the lens holder in the focusing direction is minimized, and thereafter the actuator base is fixed to the carriage by means of screws.
    Type: Grant
    Filed: May 1, 2001
    Date of Patent: December 31, 2002
    Assignee: Fujitsu Limited
    Inventors: Kazuhito Yokoyama, Yasukiyo Kunimatsu
  • Publication number: 20010024407
    Abstract: A magneto-optical memory device includes a first unit projecting a light beam onto a desired position on a recording medium, and a second unit applying a magnetic field to a position onto which the light beam is projected. The second unit applies, to the recording medium, a predetermined magnetic field within a magnetic field intensity range wherein a rate of change of a reproduced signal amplitude at the time of reproduction with respect to a magnetic field intensity becomes large. The relative positions of the second unit and the first unit are adjusted in accordance with a reproduced signal amplitude thus obtained.
    Type: Application
    Filed: December 15, 2000
    Publication date: September 27, 2001
    Applicant: Fujitsu Limited
    Inventors: Yasukiyo Kunimatsu, Kazuhito Yokoyama
  • Patent number: 6185162
    Abstract: A magneto-optical memory device includes a first unit projecting a light beam onto a desired position on a recording medium, and a second unit applying a magnetic field to a position onto which the light beam is projected. The second unit applies, to the recording medium, a predetermined magnetic field within a magnetic field intensity range wherein a rate of change of a reproduced signal amplitude at the time of reproduction with respect to a magnetic field intensity becomes large. The relative positions of the second unit and the first unit are adjusted in accordance with a reproduced signal amplitude thus obtained.
    Type: Grant
    Filed: March 31, 1999
    Date of Patent: February 6, 2001
    Assignee: Fujitsu Limited
    Inventors: Yasukiyo Kunimatsu, Kazuhito Yokoyama