Patents by Inventor Takaaki Kotaki

Takaaki Kotaki 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: 20020045114
    Abstract: In a two-component development system containing a toner and a carrier, an a-Si photosensitive member having a diameter of from 20 mm to 80 mm is used, the photosensitive member is electrostatically charged to have a surface potential of from 300 to 450 V (absolute value), and yellow, magenta, cyan and black toners are used each of which have a weight-average particle diameter of from 4.0 &mgr;m to 10.0 &mgr;m, and, under a condition that the carrier of the two-component developer has a 50% average particle diameter of from 10 &mgr;m to 80 &mgr;m and as image density (D0.5) measured usually after the toner is fixed once when the quantity of unfixed toner on a transfer medium, M/S, is 0.5 mg/cm2, have a coloring power of from 1.0 to 1.9, and in which the difference between a maximum value and a minimum value of D0.5 of yellow, magenta, cyan and black colors is form 0 to 0.5. This makes it possible to obtain high-quality images in a high image density and a superior color reproduction.
    Type: Application
    Filed: July 6, 2001
    Publication date: April 18, 2002
    Inventors: Takaaki Kaya, Takaaki Kotaki, Makoto Kanbayashi, Yushi Mikuriya, Katsumi Kondo, Wakashi Iida
  • Publication number: 20020037466
    Abstract: A magenta toner containing at least a binder resin and a colorant; the magenta toner having a storage elastic modulus at a temperature of 80° C., G′80, in the range of from 1×106 dN/m2 to 1×108 dN/m2 and a storage elastic modulus at a temperature of from 120° C. to 180° C., G′120-180, in the range of from 2×103 dN/m2 to 1×106 dN/m2, and containing at least a compound selected from the group consisting of compounds represented by the following Formulas (1) and (2) and a compound represented by the following Formula (3).
    Type: Application
    Filed: July 10, 2001
    Publication date: March 28, 2002
    Inventors: Makoto Kanbayashi, Takaaki Kotaki, Katsumi Kondo, Yasuhiro Ichikawa, Takaaki Kaya, Wakashi Iida, Takayuki Itakura
  • Patent number: 6017669
    Abstract: The toner for developing an electrostatic image has toner particles containing at least binder resin and colorant. The resin components of a range of 2,000 to 100,000 in molecular weight, prepared by preparatory liquid chromatograph from the binder resin, exhibit an M/S ratio of 200 or greater and are 50% to 90% in abundance. The M and S stand for a weight average molecular weight (M) measured by means of light scattering method and an inertia radius (S) measured by means of light scattering method, respectively.
    Type: Grant
    Filed: September 18, 1996
    Date of Patent: January 25, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Unno, Takaaki Kotaki, Yushi Mikuriya, Tadashi Doujo
  • Patent number: 5773183
    Abstract: A toner for developing an electrostatic image has a binder resin, a colorant and a charge control agent. The binder resin has a polyester resin having an acid value of from 15 to 40 and a hydroxyl value of 45 or less. The toner has, in its molecular weight distribution as measured by gel permeation chromatography, tetrahydrofuran-soluble matter having a weight average molecular weight Mw of 100,000 or more, having a ratio of weight average molecular weight Mw to number average molecular weight Mn, Mw/Mn, of not less than 35, containing from 70% to 94% of a low-molecular weight region component having a molecular weight of less than 150,000, containing from 1% to 10% of a medium-molecular weight region component having a molecular weight of from 150,000 to 500,000, and containing from 5% to 25% of a high-molecular weight region component having a molecular weight of more than 500,000. The high-molecular weight region component is more than the medium-molecular weight region component.
    Type: Grant
    Filed: November 15, 1996
    Date of Patent: June 30, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tadashi Doujo, Yuichi Mizoo, Takaaki Kotaki, Yushi Mikuriya
  • 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
  • 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
  • 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
  • Patent number: 5418102
    Abstract: A developer for developing an electrostatic image has a toner containing a binder resin and a colorant. The binder resin is comprised of an AB-type block copolymer having segment-A and segment-B.The segment-A has a copolymer structure comprised of a styrene monomer and at least one monomer selected from the group consisting of an acrylic monomer, a methacrylic monomer and a diene monomer, and the segment-B has a copolymer structure comprised of a styrene monomer and at least one monomer selected from the group consisting of an acrylic monomer, a methacrylic monomer and a diene monomer, provided that the segment-A and segment-B have copolymer structures different from each other.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: May 23, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kotaki, Yoshihiko Hyosu, Ryoichi Fujita, Makoto Kanbayashi, Minoru Shimojo