Patents by Inventor Yasuhiro Ichikawa

Yasuhiro Ichikawa 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).

  • Patent number: 5733702
    Abstract: An image forming method is conducted by forming a toner image on a latent image bearing member containing an organic photoconductive material. The latent image bearing member includes a photosensitive layer containing an organic photoconductive material and a protective layer which contains fluorine-containing resin particles in an amount from 5% by weight to 40% by weight. The toner contains toner particles and external additives. The external additives include titanium oxide particles having a weight average particle diameter from 0.01 .mu.m to 0.2 .mu.m having been subjected to hydrophobic treatment, organic resin particles having a weight average particle diameter from 0.02 .mu.m to 0.5 .mu.m, and inorganic compound particles having a weight average particle diameter from 0.5 .mu.m to 2.5 m.The inorganic compound particles may be specific titanates, oxides or carbonate.
    Type: Grant
    Filed: April 5, 1995
    Date of Patent: March 31, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenji Okado, Toshiyuki Ugai, Ryoichi Fujita, Tsuyoshi Takiguchi, Yasuhiro Ichikawa
  • Patent number: 5670288
    Abstract: A carrier for electrophotography has carrier particles. The carrier has a 50% average particle diameter (D.sub.50) of from 15 .mu.m to 45 .mu.m and contains from 1% to 20% of carrier particles with a size smaller than 22 .mu.m, not more than 3% of carrier particles with a size smaller than 16 .mu.m, from 2% to 15% of carrier particles with a size of 62 .mu.m or larger, and not more than 2% of carrier particles with a size of 88 .mu.m or larger. The carrier has a specific surface area S.sub.1 as measured by an air-permeability method and a specific surface area S.sub.2 as calculated by the following expression:S.sub.2 =(6/.rho..multidot.D.sub.50).times.10.sup.4wherein .rho. is a specific gravity of carrier; satisfying the following condition:1.2 .ltoreq.S.sub.1 /S.sub.2 .ltoreq.2.0.
    Type: Grant
    Filed: February 12, 1996
    Date of Patent: September 23, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenji Okado, Toshiyuki Ugai, Ryoichi Fujita, Makoto Kanbayashi, Tsuyoshi Takiguchi, Yasuhiro Ichikawa, Wakashi Iida
  • Patent number: 5637432
    Abstract: The present invention provides a toner for developing an electrostatic image, comprising toner particles and external additives, wherein;said external additives comprise (A) titanium oxide particles having a weight average particle diameter of from 0.01 .mu.m to 0.2 .mu.m, having been subjected to hydrophobic treatment, (B) organic resin particles having a weight average particle diameter of from 0.02 .mu.m to 0.5 .mu.m and (C) an inorganic compound having a weight average particle diameter of from 0.5 .mu.m to 2.5 .mu.m; said external additives being added in an amount satisfying the relationship:(A):(B)=2:1 to 10:1(A):(C)=1:1 to 5:1; andsaid toner contains toner particles having a particle diameter of from 2 .mu.m to 5 .mu.m in an amount of from 15% by number to 40% by number.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: June 10, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenji Okado, Toshiyuki Ugai, Ryoichi Fujita, Tsuyoshi Takiguchi, Yasuhiro Ichikawa
  • Patent number: 5512402
    Abstract: A carrier for electrophotography has carrier particles. The carrier has a 50% average particle diameter (D.sub.50) of from 15 .mu.m to 45 .mu.m and contains from 1% to 20% of carrier particles with a size smaller than 22 .mu.m, not more than 3% of carrier particles with a size smaller than 16 .mu.m, from 2% to 15% of carrier particles with a size of 62 .mu.m or larger, and not more than 2% of carrier particles with a size of 88 .mu.m or larger. The carrier has a specific surface area S.sub.1 as measured by an air-permeability method and a specific surface area S.sub.2 as calculated by the following expression:S.sub.2 =(6/.rho..D.sub.50).times.10.sup.4wherein .rho. is a specific gravity of carrier; satisfying the following condition:1.2.ltoreq.S.sub.1 /S.sub.2 .ltoreq.2.0.
    Type: Grant
    Filed: May 19, 1994
    Date of Patent: April 30, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenji Okado, Toshiyuki Ugai, Ryoichi Fujita, Makoto Kanbayashi, Tsuyoshi Takiguchi, Yasuhiro Ichikawa, Wakashi Iida
  • Patent number: 5456916
    Abstract: The present invention provides a resin molding composition for preventing gnawing damage by the animal, a microcapsule filled with a capsaicine compound, and a process for producing the capsaicine compound and the microcapsule.
    Type: Grant
    Filed: February 22, 1994
    Date of Patent: October 10, 1995
    Assignee: Nippon Kayaku Kabushiki Kaisha
    Inventors: Mitsuo Kurata, Yasuhiro Ichikawa, Mika Toya, Iwao Takahashi, Yoshinobu Okui, Shoichi Kato, Takeshi Nishitani
  • Patent number: 5322862
    Abstract: The present invention provides a resin molding composition for preventing gnawing damage by the animal, a microcapsule filled with a capsaicine compound, and a process for producing the capsaicine compound and the microcapsule.
    Type: Grant
    Filed: August 17, 1992
    Date of Patent: June 21, 1994
    Assignee: Nippon Kayaku Kabushiki Kaisha
    Inventors: Mitsuo Kurata, Yasuhiro Ichikawa, Mika Toya, Iwao Takahashi, Yoshinobu Okui