Patents by Inventor Shigenori Kouno

Shigenori Kouno 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: 6383700
    Abstract: In an electrostatic image forming method, said electrophotographic photoreceptor comprises a resinous layer comprising siloxane base resin containing a structural unit having charge transport performance and a cross-linked structure on an electrically conductive support, and developer material comprises a toner which is obtained by suspension-polymerizing a polymerizable composition comprised of at least polymerizing monomer and colorant or a toner which is obtained by fusing at least said resin particles in an aqueous medium.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: May 7, 2002
    Assignee: Konica Corporation
    Inventors: Hiroshi Yamazaki, Hiroyuki Yamada, Meizo Shirose, Shigenori Kouno, Akihiko Itami
  • Patent number: 6296980
    Abstract: Disclosed is a toner for developing electrostatic image, comprising a resin and colorant. The toner has a variation coefficient of shape coefficient of not more than 16 percent and a number variation coefficient in the number particle size distribution of not more than 27 percent. An image forming method employing the toner is also disclosed.
    Type: Grant
    Filed: November 15, 1999
    Date of Patent: October 2, 2001
    Assignee: Konica Corporation
    Inventors: Tomomi Oshiba, Ken Ohmura, Takao Yamanouchi, Asao Matsushima, Shigenori Kouno
  • Patent number: 6248494
    Abstract: A toner for developing an electrostatic image is disclosed. The toner comprises colored particles containing a resin and a colorant, the volume average particle diameter of said colored particles is 3 to 9 &mgr;m, the shape coefficient of said colored particles, which is described by the formula below, is 1.3 to 2.2, and the ratio of toner particles having a shape coefficient of 1.5 to 2.0 is at least 80 percent by number. Shape coefficient=[(maximum diameter/2)2×&pgr;]/(projection area) A developer and image forming method employing the toner are also disclosed.
    Type: Grant
    Filed: November 30, 1999
    Date of Patent: June 19, 2001
    Assignee: Konica Corporation
    Inventors: Hiroshi Yamazaki, Ken Ohmura, Tomomi Oshiba, Meizo Shirose, Shigenori Kouno
  • Patent number: 5863691
    Abstract: Disclosed is a toner for developing an electrostatic latent image, comprising colored particles containing a colorant and a binder resin, and hydrophobic particles, wherein said colored particles have a BET specific surface area of not less than 5 m.sup.2 /g and said hydrophobic particles satisfy the following relation:.vertline.pH.sub.A -pH.sub.B .vertline..ltoreq.1.0wherein said pH.sub.A is a pH value of said hydrophobic particles before heating and said pH.sub.B is a pH value of said hydrophobic particles after heating.
    Type: Grant
    Filed: June 24, 1997
    Date of Patent: January 26, 1999
    Assignee: Konica Corporation
    Inventors: Hiroshi Yamazaki, Shigenori Kouno, Michiaki Ishikawa, Mikio Kohyama
  • Patent number: 5817443
    Abstract: Toner for developing electro-static image is disclosed. The toner comprises at least a resin and a colorant, and the resin is composed of a vinyl-based polymer. The component dissolved in tetrahydrofuran (THF) of the resin has a peak molecular weight at the molecular weight region of 5,000 or more and less than 150,000 and at the molecular weight region of 300,000 or more and less than 500,000. The storage elastic module G'.sub.160 at 160.degree. C. of the toner is 500-1200 dyn/cm.sup.2 and loss elastic module G".sub.160 at 160.degree. C. of the toner is 1500-3000 dyn/cm.sup.2.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: October 6, 1998
    Assignee: Konica Corporation
    Inventors: Asao Matsushima, Shigenori Kouno, Kazuya Isobe, Yoshiaki Kobayashi, Kaori Soeda, Meizo Shirose
  • Patent number: 5376488
    Abstract: A carrier of developer for developing an electrostatic image and a method for producing the carrier are disclosed. The carrier comprises core particles each having a resin layer covering the surface of said core particle. The resin layer is formed by dry process in which the core particles are stirred together with fine resin particles with no solvent for the resin to form the resin layer on the surface of each core particle. The fine resin particles comprise a homopolymer or a copolymer comprising a fluorinated acrylate repeating unit and are formed by emulsified polymerization carried out in the presence of a surfactant comprising an alkylbenzene sulfonic compound, and the residual amount of the surfactant in the fine resin particles is within the range of from 60 ppm to 10,000 ppm. The carrier is improved in adhesion between the surface of the core and the resin layer and satisfactory in friction electricity providing capability.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: December 27, 1994
    Assignee: Konica Corporation
    Inventors: Ken Ohmura, Shigenori Kouno, Tomoyasu Umeno
  • Patent number: 5350656
    Abstract: There is disclosed an electrostatic image-developing carrier having a resin coat layer with an excellent mechanical strength. The carrier is prepared by repeatedly applying a mechanical impact force to the mixture of the core particle and the coating resin particle in a dry condition, wherein a molecular weight distribution chromatogram according to a gel permeation chromatography of a tetrahydro-furansoluble component in the resin coat layer has at least one peak or shoulder in a molecular weight range 1,000 to 20,000.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: September 27, 1994
    Assignee: Konica Corporation
    Inventors: Shigenori Kouno, Ken Ohmura, Yoshiaki Koizumi, Kenji Tsujita
  • Patent number: 5200287
    Abstract: A resin coated carrier for developing an electrostatic image is disclosed. The carrier coating layer comprises a silicone resin and a carbon fluoride having a BET specific surface area of not more than 100 m.sup.2 /g. The carrier imparts proper positive polarity triboelectric charge without charge control agent.
    Type: Grant
    Filed: July 18, 1991
    Date of Patent: April 6, 1993
    Assignee: Konica Corporation
    Inventors: Ken Ohmura, Kenji Tsujita, Shigenori Kouno
  • Patent number: 5194360
    Abstract: A method for producing a carrier for an electrostatic image developer is disclosed. The carrier comprises a core particle and a resin coating layer and is produced by a method comprising stirring a mixture of core particles, resin particles and particles of a carbon fluoride to form a resin coating layer on the surface of each core particle, the resin coating layer contains the carbon fluoride dispersed therein, in a ratio of from 5% to 45% by weight to the whole weight of the resin coat layer. A two-component developer using the carrier is improved in the durability.
    Type: Grant
    Filed: March 26, 1991
    Date of Patent: March 16, 1993
    Assignee: Konica Corporation
    Inventors: Ken Ohmura, Kenji Tsujita, Shigenori Kouno
  • Patent number: 5182181
    Abstract: The invention relates to a carrier and method of making a carrier in which elementary resin particles of volume average particle size not more than 0.5 m are fused on their surfaces to form secondary particles of BET surface areas of 5 to 150 m/g and volume average particle size of 1.5 to 5.0 m, which secondary particles are coated by a dry method on core particles to form carrier particles.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: January 26, 1993
    Assignee: Konica Corporation
    Inventors: Yoshiaki Koizumi, Kenji Tsujita, Shigenori Kouno, Ken Ohmura
  • Patent number: 5129354
    Abstract: An apparatus for producing an electrostatic image developer carrier from a material, comprising; a chamber for providing an enclosed space in which the material is processed, a stirrer for stirring the material in a horizontal direction in the chamber, and at least one of: a heater for heating up the chamber to a predetermined temperature, and a cooler for cooling down the chamber to a predetermined temperature.
    Type: Grant
    Filed: June 19, 1991
    Date of Patent: July 14, 1992
    Assignee: Konica Corporation
    Inventors: Yoshiaki Koizumi, Kenji Tsujita, Shigenori Kouno, Ken Ohmura
  • Patent number: 5075158
    Abstract: There is disclosed the method of preparing a carrier for developing a static latent image, wherein the carrier comprises a mixture of a core matrial and two or more kinds of the resin particles having different impact strengths. The method comprises applying an impact force repeatedly to said mixture to thereby fix the resin particles on the core material.
    Type: Grant
    Filed: December 11, 1989
    Date of Patent: December 24, 1991
    Assignee: Konica Corporation
    Inventors: Shigenori Kouno, Kenji Tsujita