Patents Assigned to MAXWELL, LTD.
  • Optical disc base plate and process for producing the same
    Patent number: 4812346
    Abstract: The invention discloses an optical disc base plate obtained by curing with irradiation of light a light- or radiation-curable resin composition in which a photopolymerization initiator is contained in an amount of 0.5 to 5 parts by weight per 100 parts by weight of a resin composition comprising the compounds (1), (2) and (3) mixed in amounts falling in the area defined by lines A-B-C-D-E-A in the triangular diagram of FIG.
    Type: Grant
    Filed: July 22, 1986
    Date of Patent: March 14, 1989
    Assignees: Hitachi Ltd., Hitachi Maxwell Ltd.
    Inventors: Ryoichi Sudo, Hiroaki Miwa, Tetsuo Tajima
  • Disc cartridge
    Patent number: 4740948
    Abstract: A disc cartridge comprising a cartridge case, a magnetic recording disc rotatably mounted in the cartridge case, and head insertion openings formed extending to the side portions of the cartridge case, the openings being opened even at one edge of the cartridge case for facilitating insertion of the head mounted in a recording and play back device, the cartridge case being reinforced by at least one reinforcement member having a smaller diameter or a smaller thickness than the thickness of the cartridge case.
    Type: Grant
    Filed: May 9, 1986
    Date of Patent: April 26, 1988
    Assignees: Hitachi Maxwell, Ltd., Hitachi, Ltd.
    Inventors: Yoshiyuki Nakamori, Seiichi Matsushima, Yasunori Kanazawa, Mitsuyoshi Koyama, Shinichi Abe, Nobuyuki Fujimoto
  • Magnetic recording medium
    Patent number: 4701371
    Abstract: A magnetic recording medium having good running stability and high electromagnetic characteristics which comprises a base film, a magnetic layer provided on one surface of the base film and a back coat layer provided on the other surface of the base film, said back coat layer comprising non-magnetic oxide particles at least one of complex oxide or oxide solid solutions of the SiO.sub.2 or TiO.sub.2 system.
    Type: Grant
    Filed: June 26, 1986
    Date of Patent: October 20, 1987
    Assignee: Hitachi Maxwell, Ltd.
    Inventors: Shigeo Aoyama, Yoshinori Yamamoto
  • Disc cartridge
    Patent number: 4630728
    Abstract: In a disc cartridge comprising a disc case (1) having drive shaft insertion holes (3) on the central portion of the disc case (1) and head insertion holes (4), a disc (2) is rotatably mounted in the disc case (1) and liners (12) laid on the respective inner surfaces of each of the halves of the disc case (1) so as to slidably contact with both surfaces of the disc (2), there are formed ribs (15) on said inner surfaces of the disc case so as generally to surround the part of the drive shaft insertion holes (3).
    Type: Grant
    Filed: September 5, 1984
    Date of Patent: December 23, 1986
    Assignee: Hitachi Maxwell, Ltd.
    Inventors: Fujio Matsumoto, Yoshitake Kato