Patents by Inventor Kazuyoshi Oka

Kazuyoshi Oka 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).

  • Method of making carrier for use in electrophotographic developers
    Patent number: 4751164
    Abstract: A novel carrier material useful in conjunction with a toner for preparing a two-component developer for electrophotographic processes is provided. The carrier comprises a spherical magnetite particulate material having a reduced metallic iron outer layer which is coated with an outermost resinous layer for conditioning the copying properties of the carrier.
    Type: Grant
    Filed: May 13, 1987
    Date of Patent: June 14, 1988
    Assignees: Kanto Denka Kogyo Co., Ltd., Hoganas AB
    Inventors: Mitsuhiro Katayama, Kenkichi Hara, Kazuyoshi Oka, Ulf Engstrom, Svenn E. Larssen
  • Carrier for use in electrophotographic developers
    Patent number: 4732835
    Abstract: A novel carrier material useful in conjunction with a toner for preparing a two-component developer for electrophotographic processes is provided. The carrier comprises a spherical magnetite particulate material having a reduced metallic iron outer layer which is coated with an outermost resinous layer for conditioning the copying properties of the carrier.
    Type: Grant
    Filed: June 9, 1986
    Date of Patent: March 22, 1988
    Assignees: Kanto Denka Kogyo Co., Ltd., Hoganas AB
    Inventors: Mitsuhiro Katayama, Kenkichi Hara, Kazuyoshi Oka, Ulf Engstrom, Svenn E. Larrssen
  • Carrier for use in electrophotographic developers
    Patent number: 4663262
    Abstract: A noval carrier powder for electrophotographic developers is provided. The carrier powder comprises spherical magnetite particles having a wustite (FeO) content of less than 10% by weight, a particle diameter of 30-200 .mu.m and a surface porosity of less than 20%.
    Type: Grant
    Filed: December 26, 1985
    Date of Patent: May 5, 1987
    Assignees: Kanto Denka Kogyo Co., Ltd., Hoganas AB
    Inventors: Kazuyoshi Oka, Mitsuhiro Katayama, Toshihiko Kohno, Ulf Engstrom, Svenn-Erik Larssen
  • Two-component resin system of acrylic and diene polymers for coating electrophotographic carrier particles
    Patent number: 4503136
    Abstract: A carrier for use as a component in electrophotographic two-component developers which is improved in durability of the triboelectric property by coating the surface of the iron core particles of carrier with a resinous composition comprised essentially of an epoxy-hydroxy hydrocarbon resin and an acrylic resin.
    Type: Grant
    Filed: January 24, 1983
    Date of Patent: March 5, 1985
    Assignees: Kanto Denka Kogyo Co., Ltd., Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Kenkichi Hara, Shigeo Yokoe, Kazuyoshi Oka, Tamotsu Murakami, Tsugifusa Hashimoto
  • Resin-coated carrier for use in two-component electrophotographic developers
    Patent number: 4486502
    Abstract: A carrier for use as a component in electrophotographic two-component developers which is improved in durability of the triboelectric property by coating the surface of the iron core particles of carrier with a resinous composition comprised essentially of an epoxy-hydroxy hydrocarbon resin and a silicone resin.
    Type: Grant
    Filed: January 4, 1983
    Date of Patent: December 4, 1984
    Assignees: Kanto Denka Kogyo Co. Ltd., Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Kenkichi Hara, Shigeo Yokoe, Kazuyoshi Oka, Tamotsu Murakami, Tsugifusa Hashimoto