Patents by Inventor Syuichi Hashimoto

Syuichi Hashimoto 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).

  • Disk apparatus for detecting position of head by reading phase servo pattern
    Patent number: 5694265
    Abstract: A duty pulse is formed by setting in response to a leading edge of a clock synchronized with a peak detection of a servo frame read signal by a peak detecting circuit and by resetting by a signal by which a zero-cross point of a read signal of a phase servo pattern was detected. A head position signal is formed by integrating the duty pulse. Since there is a deviation of the timings between the peak detection and the zero-cross detection, a duty ratio is measured so as to be adjusted to 50% in the on-track state of a target cylinder. The timings for a reference clock and a zero-cross detection pulse are delayed and adjusted accordingly.
    Type: Grant
    Filed: August 30, 1994
    Date of Patent: December 2, 1997
    Assignee: Fujitsu Limited
    Inventors: Tatsuhiko Kosugi, Susumu Yoshida, Makoto Chiba, Syuichi Hashimoto, Masahide Kanegae
  • Method of compensating offtrack in disk unit
    Patent number: 5521773
    Abstract: In a disk unit including a plurality of disk media of which any one surface is a servo surface and the other surfaces are all data surfaces; a servo head and data heads arranged on the servo surface and the data surfaces; a positioning mechanism for positioning the servo head and the data heads on desired tracks; and a control unit for controlling the positioning mechanism; the control unit reading servo data from the data surfaces and updates them to find offtrack compensated data, and the head positioning operation being controlled by using the offtrack compensated data and servo information on the servo surface, an offset occurring in the disk unit is compensated by setting the servo track center of the servo head as a reference for positioning the head; writing a pair of servo data for positioning the head onto said data surface while giving a predetermined offset amount which is offset from said track center; giving a predetermined offset amount to thus read and measure the pair of servo data and using t
    Type: Grant
    Filed: February 16, 1995
    Date of Patent: May 28, 1996
    Assignee: Fujitsu Limited
    Inventors: Nobuyuki Suzuki, Syuichi Hashimoto
  • Method of compensating offtrack in disk unit
    Patent number: 5455724
    Abstract: In a disk unit including a plurality of disk media of which any one surface is a servo surface and the other surfaces are all data surfaces; a servo head and data heads arranged on the servo surface and the data surfaces; a positioning mechanism for positioning the servo head and the data heads on desired tracks; and a control unit for controlling the positioning mechanism; the control unit reading servo data from the data surfaces and updates them to find offtrack compensated data, and the head positioning operation being controlled by using the offtrack compensated data and servo information on the servo surface, an offset occurring in the disk unit is compensated by setting the servo track center of the servo head as a reference for positioning the head; writing a pair of servo data for positioning the head onto said data surface while giving a predetermined offset amount which is offset from said track center; giving a predetermined offset amount to thus read and measure the pair of servo data and using t
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: October 3, 1995
    Assignee: Fujitsu Limited
    Inventors: Nobuyuki Suzuki, Syuichi Hashimoto