Patents by Inventor Emi Mangyo

Emi Mangyo 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: 6177208
    Abstract: A magnetic recording system high in S/N and low in bit error rate, capable of carrying out writing and reading of high recording density of at least 1 gigabit per 1 square inch and high in reliability can be realized by making the magnetic layer of the magnetic recording medium from a mixture comprising at least one non-magnetic compound selected from the group consisting of oxides and nitrides and a magnetic material comprising Co and Pt as main components and specifying the molar ratio of Pt to Co in the magnetic layer, and employing a magnetoresistive read back magnetic recording head.
    Type: Grant
    Filed: May 25, 1999
    Date of Patent: January 23, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Tomoo Yamamoto, Nobuyuki Inaba, Masukazu Igarashi, Masaaki Futamoto, Yuzuru Hosoe, Ichiro Tamai, Emi Mangyo, Kazusuke Yamanaka
  • Patent number: 5919581
    Abstract: A magnetic recording system high in S/N and low in bit error rate, capable of carrying out writing and reading of high recording density of at least 1 gigabit per 1 square inch and high in reliability can be realized by making the magnetic layer of the magnetic recording medium from a mixture comprising at least one non-magnetic compound selected from the group consisting of oxides and nitrides and a magnetic material comprising Co and Pt as main components and specifying the molar ratio of Pt to Co in the magnetic layer, and employing a magnetoresistive read back magnetic recording head.
    Type: Grant
    Filed: June 25, 1996
    Date of Patent: July 6, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Tomoo Yamamoto, Nobuyuki Inaba, Masukazu Igarashi, Masaaki Futamoto, Yuzuru Hosoe, Ichiro Tamai, Emi Mangyo, Kazusuke Yamanaka
  • Patent number: 5723198
    Abstract: In a magnetic recording system including magnetic recording media, a rotation driving unit for driving these magnetic recording media, read/write magnetic heads, driving apparatus for driving these read/write magnetic heads, and a read/write signal processing apparatus, a reading portion of the respective magnetic heads is arranged by a magnetoresistive head. The magnetic recording media are constructed of multi-layered magnetic media having a plurality of magnetic layers fabricated directly, or via underlayers on a non-magnetic disk substrate, and of non-magnetic intermediate layers arranged among these non-magnetic layers.
    Type: Grant
    Filed: June 13, 1994
    Date of Patent: March 3, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Yuzuru Hosoe, Yoshihiro Shiroishi, Akira Ishikawa, Futoshi Tomiyama, Kazuetsu Yoshida, Tomoo Yamamoto, Yotsuo Yahisa, Akira Osaki, Katsuo Abe, Shinji Narishige, Naoki Kodama, Kiwamu Tanahashi, Emi Mangyo
  • Patent number: 5650889
    Abstract: A magnetic recording medium having a high coercivity and a high S/N ratio for high-density operation can include either a conductive or a nonconductive substrate. If the substrate is nonconductive, a conducting precoat layer is formed over the substrate. Further, an underlayer may be provided, over which a magnetic layer is formed by a bias sputtering method. The bias sputtering method may use Kr, Xe or Rn as a sputter gas, and employs a negative bias voltage. The magnetic recording medium has a product of remanent magnetization and magnetic layer thickness of 10-150 G.multidot..mu.m and a coercivity of 1600-4000 Oe. In combination with this magnetic recording medium, a large-capacity magnetic recording system has a write head that uses a magnetic material having a saturation magnetic flux density of more than 1.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: July 22, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Tomoo Yamamoto, Yuzuru Hosoe, Emi Mangyo, Masaaki Futamoto, Nobuyuki Inaba