Patents by Inventor Michihiro Matsui

Michihiro Matsui 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).

  • Method of and device for demagnetizing magnetic recording medium
    Patent number: 5053893
    Abstract: A magnetic recording medium such as a magnetic recording tape or disk is demagnetized by applying a saturating magnetic field to the magnetic recording medium, then applying an unsaturating magnetic field to the magnetic recording medium in a direction opposite to the direction of the saturating magnetic field, and finally applying an alternating magnetic field to the magnetic recording medium to remove residual magnetism which has been produced on the magnetic recording medium by the unsaturating magnetic field. The saturating, unsaturating, and alternating magnetic fields are generated respectively by a first DC erasing head, a second DC erasing head, and an AC erasing head, which are arranged at spaced intervals in the order named in the direction in which the magnetic recording medium is continuously moved.
    Type: Grant
    Filed: July 6, 1990
    Date of Patent: October 1, 1991
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Youichi Hayata, Michihiro Matsui
  • Method of and device for demagnetizing magnetic recording medium
    Patent number: 4956728
    Abstract: A magnetic recording medium such as a magnetic recording tape or disk is demagnetized by applying a saturating magnetic field to the magnetic recording medium, then applying an unsaturating magnetic field to the magnetic recording medium in a direction opposite to the direction of the saturating magnetic field, and finally applying an alternating magnetic field to the magnetic recording medium to remove residual magnetism which has been produced on the magnetic recording medium by the unsaturating magnetic field. The saturating, unsaturating, and alternating magnetic fields are generated respectively by a first DC erasing head, a second DC erasing head, and an AC erasing head, which are arranged at spaced intervals in the order named in the direction in which the magnetic recording medium is continuously moved.
    Type: Grant
    Filed: November 19, 1986
    Date of Patent: September 11, 1990
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Youichi Hayata, Michihiro Matsui