Patents by Inventor Shyuichi Kojima

Shyuichi Kojima 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-type recording medium and storage apparatus
    Patent number: 5272581
    Abstract: A disk-type recording medium having a circular substrate on which a recording layer is formed does not include any through hole formed in the center of rotation. Since no through hole is formed, it is possible to improve the reliability of the medium with regard to its strength, and to reduce the thickness of the substrate. Further, it is possible to render the thickness of the recording coating uniform.
    Type: Grant
    Filed: September 13, 1991
    Date of Patent: December 21, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Shyuichi Kojima, Hiroyuki Suzuki, Akira Kato, Keigo Iechika, Mikio Takada, Masaki Ohura
  • Magnetic recording media for longitudinal recording
    Patent number: 4792497
    Abstract: Disclosed is a magnetic recording medium of the magnetic metal thin-film type for longitudinal recording, in which the noise is reduced by selecting the value of maximum torque L (the product of magnetic anisotropy energy Ku and magnetic layer volume v; as measured by setting the axis of rotation in plane of the medium) and the value of magnetic flux .phi. (the product of saturation magnetization Ms and magnetic layer volume v) from a range defined by 0<L/(2.pi..multidot..phi..sup.2)<4.times.10.sup.5 (erg/emu.sup.2).
    Type: Grant
    Filed: January 28, 1988
    Date of Patent: December 20, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Suzuki, Yoshihiro Shiroishi, Sadao Hishiyama, Tomoyuki Ohno, Kazuetsu Yoshida, Shyuichi Kojima, Susumu Funamoto, Yasushi Kitazaki, Sakae Ohta, Hajime Aoi