Patents by Inventor Masaaki Shidochi

Masaaki Shidochi 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).

  • Publication number: 20080253264
    Abstract: An optical pickup device according to an aspect of the present invention includes a rotary mechanism which rotates a half-wave plate in mechanical conjunction with drive of first and second collimator lenses. The rotary mechanism locates the half-wave plate at a first rotational position when the first collimator lens is located at a control operation position, and the rotary mechanism locates the half-wave plate at a second rotational position when the second collimator lens is located at the control operation position. When the rotational position of the half-wave plate is switched between the first rotational position and the second rotational position, a polarization direction of a laser beam is changed with respect to the polarization beam splitter to switch an optical path of the laser beam.
    Type: Application
    Filed: April 11, 2008
    Publication date: October 16, 2008
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Kenji NAGATOMI, Masaaki Shidochi
  • Patent number: 6693856
    Abstract: A magneto-optical disk apparatus includes a magnetic head in a position opposed to an objective lens included in an optical head with a magneto-optical record medium therebetween. The magneto-optical disk apparatus includes a magnet for cancelling a first magnetic field emitted toward the magnetic head from a magnet for focus servo-control or tracking servo-control of the objective lens. The magnet emits a second magnetic field in a direction toward the magnetic head. The second magnetic field is opposite in direction to the first magnetic field, and has the same intensity as the first magnetic field. Consequently, the signal can be accurately reproduced from the magneto-optical record medium while removing a magnetic influence from the magnet included in the optical head.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: February 17, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masaaki Shidochi, Kanichi Koyama, Yoichi Tsuchiya, Mitsuhiko Maeda, Seiji Kajiyama, Seiichiro Takahashi
  • Publication number: 20020034128
    Abstract: A magneto-optical disk apparatus includes a magnetic head in a position opposed to an objective lens included in an optical head with a magneto-optical record medium therebetween. The magneto-optical disk apparatus includes a magnet for cancelling a first magnetic field emitted toward the magnetic head from a magnet for focus servo-control or tracking servo-control of the objective lens. The magnet emits a second magnetic field in a direction toward the magnetic head. The second magnetic field is opposite in direction to the first magnetic field, and has the same intensity as the first magnetic field. Consequently, the signal can be accurately reproduced from the magneto-optical record medium while removing a magnetic influence from the magnet included in the optical head.
    Type: Application
    Filed: September 17, 2001
    Publication date: March 21, 2002
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Masaaki Shidochi, Kanichi Koyama, Yoichi Tsuchiya, Mitsuhiko Maeda, Seiji Kajiyama, Seiichiro Takahashi