Patents by Inventor Kiyokazu Tohma

Kiyokazu Tohma 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: 5087476
    Abstract: The method includes applying ions and electrons from an ion gun onto a polymer film while the polymer film is traveling circumferentially along a peripheral surface of a cylindrical can from a supply location to a take-up location of the polymer film relative to the cylindrical drum. The ions and electrons from the ion gun are applied onto a part of the polymer film while it is moving through a position near the supply location of the polymer film relative to the drum at which the polymer film begins to contact the outer peripheral surface of the drum. At a downstream location relative to the drum, electrons are applied from an electron gun onto the polymer film traveling on the drum surface. At a further downstream location relative to the drum, the thin film is deposited, e.g., by vacuum evaporation, on the polymer film travelling on the drum. This method enables a thin film, having no wrinkles and with a high adhesion strength with respect to the polymer film, to be produced in a stable manner.
    Type: Grant
    Filed: March 2, 1990
    Date of Patent: February 11, 1992
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kiyokazu Tohma, Ryuji Sugita, Kazuyoshi Honda, Yasuhiro Kawawake, Tatsuaki Ishida
  • Patent number: 4999220
    Abstract: In manufacturing perpendicular magnetic recording medium wherein a magnetic layer containing Co and Cr as main contents on a running substrate of polymer film incident angle (.phi..sub.f) of vaporized atom to form said magnetic layer is 30.degree. or larger at the final part of the film formation to improve manufacturing capacity, and magnetic layer (119) is heated after forming the magnetic layer in an oxygen-containing atmosphere.
    Type: Grant
    Filed: February 16, 1989
    Date of Patent: March 12, 1991
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuyoshi Honda, Ryuji Sugita, Kiyokazu Tohma, Yasuihiro Kawawake, Yoshiki Murakami
  • Patent number: 4859501
    Abstract: A perpendicular magnetic recording method uses a perpendicular magnetic recording medium. This medium comprises a perpendicular anisotropy film having perpendicular remanent magnetization Mr and longitudinal remanent magnetization Mr.sub..parallel., wherein the value of the ratio Mr.sub..perp. /Mr.sub..parallel. is not less than 0.2, but is less than 1.
    Type: Grant
    Filed: December 31, 1987
    Date of Patent: August 22, 1989
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Ryuji Sugita, Kiyokazu Tohma, Kazuyoshi Honda, Taro Nanbu