Patents by Inventor Koh Ishigami

Koh Ishigami 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).

  • Publication number: 20060008723
    Abstract: The present invention provides a toner improved in dispersibility of a colorant in the toner particles and excellent in the color reproducibility including color mixability and transparency. The toner is also excellent in the stability in long-term of the chargeability and capable of forming images maintaining high image quality. The present invention provides a toner for forming a full-color image which includes at least toner particles containing a binder resin, a colorant and a wax, and inorganic fine particles, wherein the binder resin comprises a resin having polyester units which is synthesized by use of an aromatic carboxylic acid titanium compound as a catalyst, and the inorganic fine particles comprise fine titanium oxide particles.
    Type: Application
    Filed: September 14, 2005
    Publication date: January 12, 2006
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroyuki Fujikawa, Nobuyoshi Sugahara, Takayuki Itakura, Naoki Okamoto, Koh Ishigami, Yoshinobu Baba, Hirohide Tanikawa
  • Publication number: 20050244737
    Abstract: An image forming method and an image forming apparatus are disclosed in which an electrostatic latent image is formed on a photosensitive member surface by using a two-component developer including a toner and carrier. The photosensitive member surface has a specific modulus of elastic deformation and includes a charge transport layer with a specific thickness. The toner has a specific weight-average particle diameter. The carrier has a specific volume-average particle diameter and a specific circularity, and contains 20% by number or less of particles having a value of “average circularity?2 ?” where ? is standard deviation of carrier circularity.
    Type: Application
    Filed: April 26, 2005
    Publication date: November 3, 2005
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yoshinobu Baba, Hiroyuki Fujikawa, Nobuyoshi Sugahara, Koh Ishigami, Naoki Okamoto, Takayuki Itakura
  • Publication number: 20050238988
    Abstract: In an image forming method having primarily transferring step for transferring to an intermediate transfer member a toner image formed on a photosensitive member, secondarily transferring step for transferring to a transfer material the toner image held on the intermediate transfer member, and, after the secondary transferring step, cleaning step for removing the toner remaining on the intermediate transfer member by bringing a cleaning means into contact with the intermediate transfer member, the cleaning means is a fur brush or a charging roller, and the intermediate transfer member has a specific maximum displacement quantity (Sb) and has a specific elastic deformation percentage (Eb) (%); a toner which forms the toner image has a specific average circularity, has a specific maximum displacement quantity (St), and has a specific elastic deformation percentage (Et) (%); and the elastic deformation percentage of the intermediate transfer member and the elastic deformation percentage of the toner satisfy the
    Type: Application
    Filed: April 18, 2005
    Publication date: October 27, 2005
    Applicant: Canon Kabushiki Kaisha
    Inventors: Nobuyoshi Sugahara, Hiroyuki Fujikawa, Koh Ishigami, Naoki Okamoto, Yoshinobu Baba, Takayuki Itakura
  • Publication number: 20050238392
    Abstract: The present invention relates to a developing method using a developing device including at least: a first developer bearing member arranged to be opposed to an image bearing member; and a second developer bearing member arranged on a downstream side of a rotation direction of the image bearing member with respect to the first developer bearing member, the developing method including developing a latent image formed on the image bearing member with a developer, in which: the developer is a two-component developer having toner and a magnetic carrier; and the developer has a degree of compression C in the range of 20 to 32% and a shearing stress obtained by shearing stress measurement under a consolidation load of 4.0×10?4 N/mm2 in the range of 0.5×10?4 to 2.5×10?4 N/mm2.
    Type: Application
    Filed: April 26, 2005
    Publication date: October 27, 2005
    Applicant: Canon Kabushiki Kaisha
    Inventors: Naoki Okamoto, Hiroyuki Fujikawa, Koh Ishigami, Nobuyoshi Sugahara, Yoshinobu Baba, Takayuki Itakura
  • Publication number: 20050112489
    Abstract: A magnetic carrier composed of carrier particles is provided in which each carrier particle has a carrier core including magnetic fine particles and a binder resin with the carrier core surface being coated with a coat material containing a coat resin. In the magnetic carrier, Fatom/Catom and (Fatom/Catom)/(Fcalc/Ccalc) are respectively in specific ranges, wherein Fatom and Catom represent respectively a fluorine element abundance ratio and a carbon element abundance ratio at the magnetic carrier particle surface, and Fcalc and Ccalc represent respectively a fluorine element abundance ratio and a carbon element abundance ratio which are calculable from the molecular structure of the coat resin. In addition, a two-component developer is provoded including the magnetic carrier and a toner having a specific contact angle against water.
    Type: Application
    Filed: November 16, 2004
    Publication date: May 26, 2005
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroyuki Fujikawa, Takayuki Itakura, Takakuni Kobori, Koh Ishigami, Nobuyoshi Sugahara, Yoshinobu Baba, Hirohide Tanikawa
  • Publication number: 20050106489
    Abstract: An image forming apparatus includes an electrophotographic photosensitive member and a toner. The photosensitive member has a universal hardness of 1.5×108 to 2.3×108 N/m2, the hardness being measured in an environment of 25° C. with a humidity of 50% using a Vickers diamond indenter having a quadrangular pyramid shape with a maximum load of 6 mN, and has an elastic deformation ratio of 46% to 65%. The toner has a weight average particle diameter of 4.0 to 8.0 ?m, the average circularity of the toner having an equivalent circle diameter of at least 2 ?m is 0.915 to 0.950, the toner has a storage modulus at 80° C. of 1×105 to 1×108 Pa, and a ratio of a loss modulus G? of the toner to the storage modulus G? of the toner (G?/G?=tan ?) is equal to 1 at a temperature in the range of 60° C. to 72° C.
    Type: Application
    Filed: November 16, 2004
    Publication date: May 19, 2005
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Nobuyoshi Sugahara, Takayuki Itakura, Koh Ishigami, Hiroyuki Fujikawa, Takakuni Kobori, Hirohide Tanikawa
  • Publication number: 20050079429
    Abstract: In a color toner having toner particles which have toner base particles containing a binder resin, a colorant and a wax, and inorganic fine particles, (i) in the toner base particles, particles having a circle-equivalent diameter of 3.00 ?m or more as measured with a flow type particle image analyzer have an average circularity of from 0.920 or more to less than 0.950, (ii) in the particles having a circle-equivalent diameter of 3.00 ?m or more in the toner base particles, particles having a circularity of 0.960 or more are in a number frequency cumulative value of 40% or less; and (iii) in the particles having a circle-equivalent diameter of 3.00 ?m or more in the toner base particles, particles having a circularity of 0.920 or less are in a number frequency cumulative value of 30% or less. Also disclosed is a full-color image forming method making use of the toner.
    Type: Application
    Filed: September 9, 2004
    Publication date: April 14, 2005
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kazuhiko Hayami, Tetsuya Ida, Nozomu Komatsu, Yasuhiro Ichikawa, Akira Hashimoto, Hirohide Tanikawa, Takakuni Kobori, Takayuki Itakura, Hiroyuki Fujikawa, Koh Ishigami, Nobuyoshi Sugahara