Patents by Inventor Hihumi Nagai

Hihumi Nagai 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).

  • Magnetic head comprising a laminated magnetic layer structure between non magnetic rock salt structure oxide substrates
    Patent number: 5231555
    Abstract: A non-magnetic substrate used for a magnetic head comprising a pair of non-magnetic substrates, and a magnetic layer structure sandwiched between the pair of non-magnetic substrates. The magnetic layer structure is comprised, of alternately laminated magnetic layers and intermediate insulating layers. The invention discloses for the substrate material a composition expressed by Zn.sub.x M.sub.y Co.sub.2-x-y O.sub.2, with the proviso that M is Mn or Ni, 0.ltoreq.x.ltoreq.0.4, 0.4.ltoreq.y.ltoreq.1.0, 0.8.ltoreq.x+y.ltoreq.1.0, or Co.sub.x Ni.sub.2-x O.sub.2, with the proviso that 0.2.ltoreq.x .ltoreq.1.8, and having a rock-salt structure.
    Type: Grant
    Filed: September 20, 1991
    Date of Patent: July 27, 1993
    Assignee: Nippon Mining Co., Ltd.
    Inventors: Eiji Itoh, Ryuichi Nagase, Kazuhiro Saito, Hiroshi Hosaka, Hihumi Nagai
  • Non-magnetic substrate of magnetic head, magnetic head and method for producing substrate
    Patent number: 5089196
    Abstract: A non-magnetic substrate used for a magnetic head comprising a pair of non-magnetic substrates, and a magnetic layer structure sandwiched between the pair of non-magnetic substrates. The magnetic layer structure is comprised, of alternately laminated magnetic layers and intermediate insulating layers. The invention discloses for the substrate material a composition expressed by Zn.sub.x M.sub.y Co.sub.2-x-y O.sub.2, with the proviso that M is Mn or Ni, 0.ltoreq.x.ltoreq.0.4, 0.4.ltoreq.y.ltoreq.1.0, 0.8.ltoreq.x+y.ltoreq.1.0, or Co.sub.x Ni.sub.2-x O.sub.2, with the proviso that 0.2.ltoreq.x.ltoreq.1.8, and having a rock-salt structure.
    Type: Grant
    Filed: April 12, 1991
    Date of Patent: February 18, 1992
    Assignee: Nippon Mining Co., Ltd.
    Inventors: Eiji Itoh, Ryuichi Nagase, Kazuhiro Saito, Hiroshi Hosaka, Hihumi Nagai
  • Magnetic recording medium with a zinc cobalt oxide non-magnetic substrate containing nickel or manganese
    Patent number: 5026614
    Abstract: A non-magnetic substrate used for a magnetic head comprising a pair of non-magnetic substrates, and a magnetic layer structure sandwiched between the pair of non-magnetic substrates. The magnetic layer structure is comprised, of alternately laminated magnetic layers and intermediate insulating layers. The invention discloses for the substrate material a composition expressed by Zn.sub.x M.sub.y Co.sub.2-x-y O.sub.2, with the proviso that M is Mn or Ni, 0.ltoreq.x.ltoreq.0.4, 0.4.ltoreq.y.ltoreq.1.0, 0.8.ltoreq.x+y.ltoreq.1.0, or CO.sub.x Ni.sub.2-x O.sub.2, with the proviso that 0.2.ltoreq.x.ltoreq.1.8, and having a rock-salt structure.
    Type: Grant
    Filed: February 24, 1989
    Date of Patent: June 25, 1991
    Assignee: Nippon Mining Co., Ltd.
    Inventors: Eiji Itoh, Ryuichi Nagase, Kazuhiro Saito, Hiroshi Hosaka, Hihumi Nagai