Patents by Inventor Seiichi Takagi

Seiichi Takagi 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 comprising magnetic powders having controlled size distribution
    Patent number: 4543312
    Abstract: A magnetic toner comprises magnetic powders having a particle distribution that the particle size of 50% accumulated volume, the particle size of 25% accumulated volume and the particle size of 75% accumulated volume of the magnetic powders are 1.5-4.5.mu., 1.0-4.0.mu. and 2.5-6.0.mu., respectively. This magnetic toner can produce high density and clear images and further, can produce colorful images.
    Type: Grant
    Filed: April 26, 1983
    Date of Patent: September 24, 1985
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazunori Murakawa, Yasuo Mitsuhashi, Hitoshi Uchide, Seiichi Takagi, Masaki Uchiyama, Hisayuki Ochi, Motoo Urawa, Eiichi Imai
  • Magnetic color toner
    Patent number: 4448870
    Abstract: Red to sepia magnetic toners stable to heat and light which do not fade or discolor for a long period of time are prepared by incorporating a partially .alpha.-transformed .gamma.-Fe.sub.2 O.sub.3 as a component in a toner.
    Type: Grant
    Filed: April 11, 1983
    Date of Patent: May 15, 1984
    Assignee: Canon Kabushiki Kaisha
    Inventors: Eiichi Imai, Hitoshi Uchide, Kazunori Murakawa, Masaki Uchiyama, Hisayuki Ochi, Motoo Urawa, Seiichi Takagi, Yasuo Mitsuhashi