Patents by Inventor Hirokazu Ishizaki

Hirokazu Ishizaki 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).

  • Spindle motor having temperature compensation member encircling hub body around bearing
    Patent number: 6330126
    Abstract: The spindle motor comprises a stationary axis fixed to a housing of a recording disk apparatus, and a hub body supported around the stationary axis by upper and lower ball bearings for rotation. A member serves to at least partly surround the hub body around the upper and lower ball bearings. Thermal expansion of the hub body may be suppressed by the member having a thermal expansion coefficient smaller than that of the hub body.
    Type: Grant
    Filed: September 29, 1998
    Date of Patent: December 11, 2001
    Assignee: Fujitsu Limited
    Inventors: Hirokazu Ishizaki, Shinji Tsukada
  • DISK APPARATUS WITH REAL-TIME ECCENRICITY CORRECTION
    Publication number: 20010013989
    Abstract: For a balance adjustment due to a reduction in size and weight of an actuator, an arm portion, an axis attaching portion, and a coil supporting portion are arranged so that the centers of gravity on the coil side are located on a straight line connecting a rotational center and the center of gravity on the head side. Further, the improvement of an assembling efficiency of a VCM, an increase in torque, a one-touch fixing of an FPC connecting band, a noise prevention of a read pattern, and an insulation between the base and cover due to a bias of an MR read head are accomplished. A sector mark is detected by comparing a peak detection pulse and its reference polarity signal. A redundancy is provided to a reference detection polarity signal so that a read signal can be detected even if any one of the read signals of the sector marks is dropped out.
    Type: Application
    Filed: April 24, 1998
    Publication date: August 16, 2001
    Applicant: FUJITSU LIMITED
    Inventors: MASARU SAIKI, TSUTOMU SASAKI, HIROKAZU ISHIZAKI, EIJI OKAMURA, TATSUYA GOFUKU, NORIHIKO SUZUKI, KOICHI TOHKAIRIN, HIROFUMI SUZUKI, KENJI ENDO, CHIHIRO ONO, KAZUHIDE OHBA, ATSUSHI SATOH, EISAKU TAKAHASHI, TAKASHI TOKAIRIN, ISAO SUDA, TAKAHIRO ONO
  • Head positioning control for disk apparatus using peak detection, polarity detection and sector mark detection
    Patent number: 5798885
    Abstract: For a balance adjustment due to a reduction in size and weight of an actuator, an arm portion, an axis attaching portion, and a coil supporting portion are arranged so that the centers of gravity on the coil side are located on a straight line connecting a rotational center and the center of gravity on the head side. Further, the improvement of an assembling efficiency of a VCM, an increase in torque, a one-touch fixing of an FPC connecting band, a noise prevention of a read pattern, and an insulation between the base and cover due to a bias of an MR read head are accomplished. A sector mark is detected by comparing a peak detection pulse and its reference polarity signal. A redundancy is provided to a reference detection polarity signal so that a read signal can be detected even if any one of the read signals of the sector marks is dropped out.
    Type: Grant
    Filed: May 5, 1995
    Date of Patent: August 25, 1998
    Assignee: Fujitsu Limited
    Inventors: Masaru Saiki, Tsutomu Sasaki, Hirokazu Ishizaki, Eiji Okamura, Tatsuya Gofuku, Norihiko Suzuki, Koichi Tohkairin, Hirofumi Suzuki, Kenji Endo, Chihiro Ono, Kazuhide Ohba, Atsushi Satoh, Eisaku Takahashi, Takashi Tokairin, Isao Suda, Takahiro Ono