Patents by Inventor Tadashi Dojyo

Tadashi Dojyo 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 toner and image forming method
    Patent number: 5641600
    Abstract: A magnetic toner composed of a binder resin and magnetic fine particles, wherein the magnetic fine particles are coated with an iron-zinc oxide on their surfaces and the magnetic fine particles have a saturation magnetization (.sigma.s) of 50 Am.sup.2 /kg or above under a magnetic field of 79.58 kA/m (1K oersted) where the product of residual magnetization (.sigma.r, Am.sup.2 /kg) and coercive force (Hc, kA/m), .sigma.r.times.Hc, is in the range between 60 and 250 (kA.sup.2 m/kg).
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: June 24, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kotaki, Masaki Uchiyama, Yasutaka Akashi, Makoto Unno, Yushi Mikuriya, Tadashi Dojyo
  • Toner for developing electrostatic images, image forming method and process cartridge
    Patent number: 5604072
    Abstract: A toner for developing electrostatic images comprises,(i) a binder resin,(ii) a colorant, and(iii) a compound made by a reaction of a monohydroxylic compound having a long-chain alkyl group having an alkylene group with 40 or more carbon atoms and a hydroxyl group with a carboxylic acid having a molecular weight of 1,000 or less, or a compound made by a reaction of a monocarboxylic compound having a long-chain alkyl group having an alkylene group with 40 or more carbon atoms and a carboxyl group with an alcohol having a molecular weight of 1,000 or less.
    Type: Grant
    Filed: September 19, 1995
    Date of Patent: February 18, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Unno, Takaaki Kotaki, Yushi Mikuriya, Tadashi Dojyo
  • Toner for developing electrostatic image, one component-type developer and two-component type developer
    Patent number: 5578409
    Abstract: A toner for developing an electrostatic image has a binder resin and a colorant.The binder resin contains a polyester resin at least part of which has a long-chain alkyl group having 22 to carbon atoms and has a hydroxyl group or a carboxyl group at its terminal.
    Type: Grant
    Filed: November 15, 1995
    Date of Patent: November 26, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kotaki, Masaaki Taya, Makoto Unno, Yushi Mikuriya, Tadashi Dojyo