Patents by Inventor Yoosuke Hamada

Yoosuke Hamada 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: 5229896
    Abstract: A disk drive has a data recording medium disk, a head disposed facing a recording surface of the disk, for reading and writing data, a positioning mechanism for supporting and moving the head, a position detector for detecting the position of the head and outputting a position detection signal, and a control unit for processing the position detection signal and outputting a position control signal to the positioning mechanism.
    Type: Grant
    Filed: October 23, 1991
    Date of Patent: July 20, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Souichi Tohyama, Hiromu Hirai, Haruaki Otsuki, Yoosuke Hamada
  • Patent number: 4956789
    Abstract: When a move command (data indicating to move a movable unit from one position to a target position) is issued, a movable unit is displaced in response to the move command. A target trajectory which is an aggregation of target positions varying with time is determined such that a residual vibration of a structure at and after the stop of displacement of the movable unit is minimized. Target positions at various times during the displacement of the movable unit are generated based on the target trajectory. The target positions at various times are supplied to a control unit which feeds back an actual position of the movable unit and produces a drive signal which makes a difference from the target position zero. The drive signal is supplied to an actuator so that a drive force is transmitted from the actuator to the movable unit which follows a change in the target position. As a result, the movable unit is moved to the target position and the vibration at and after the stop of movement is suppressed.
    Type: Grant
    Filed: May 10, 1988
    Date of Patent: September 11, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Yoosuke Hamada, Hiromu Hirai, Isao Kobayashi