Patents by Inventor Kenichi Ohkuwa

Kenichi Ohkuwa 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: 6952550
    Abstract: A toner supply roll free from occurrence of an imaging failure. The toner supply roll comprises a shaft (1) and a urethane foam layer (2) provided on an outer peripheral surface of the shaft (1), wherein when the urethane foam layer is compressed to a depth of 1 mm from an outermost surface thereof during compression thereof to a depth of 2 mm, a stress F0 occurs in the urethane foam layer and when the urethane foam layer is decompressed to a depth of 1 mm after the compression thereof to a depth of 2 mm, a stress F1 occurs in the urethane foam layer, the urethane foam layer satisfies a relation represented by the following expression (1) at a temperature of 23±3° C. at a humidity of 50±10%: F1/F0?0.7??(1) the stresses F1 and F0 being expressed by a unit of Pa.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: October 4, 2005
    Assignee: Tokai Rubber Industries, Ltd.
    Inventors: Kenichi Ohkuwa, Eiji Yasui, Kazunori Toyama
  • Publication number: 20040086303
    Abstract: A toner supply roll free from occurrence of an imaging failure. The toner supply roll comprises a shaft (1) and a urethane foam layer (2) provided on an outer peripheral surface of the shaft (1), wherein when the urethane foam layer is compressed to a depth of 1 mm from an outermost surface thereof during compression thereof to a depth of 2 mm, a stress F0 occurs in the urethane foam layer and when the urethane foam layer is decompressed to a depth of 1 mm after the compression thereof to a depth of 2 mm, a stress F1 occurs in the urethane foam layer, the urethane foam layer satisfies a relation represented by the following expression (1) at a temperature of 23±° C.
    Type: Application
    Filed: October 29, 2003
    Publication date: May 6, 2004
    Applicant: TOKAI RUBBER INDUSTRIES, LTD.
    Inventors: Kenichi Ohkuwa, Eiji Yasui, Kazunori Toyama
  • Patent number: 6146320
    Abstract: A conductive roll available at low cost and superior both in moldability and compression set and having small dispersion or fluctuation in electrical resistance includes a shaft and a base rubber layer formed on a peripheral surface of the shaft, the base rubber layer formed of a composition containing the following components (A) to (C): (A) a liquid polymer having a structural unit (.alpha.) derived from at least one of butadiene and isoprene and having an alkenyl group in a side chain thereof; (B) a hydrosilylation crosslinking agent; and (C) a hydrosilylation catalyst. In the conductive roll the alkenyl group of the structural unit (.alpha.
    Type: Grant
    Filed: July 28, 1999
    Date of Patent: November 14, 2000
    Assignee: Tokai Rubber Industries, Ltd.
    Inventors: Hitoshi Yoshikawa, Shoji Arimura, Kunio Ito, Sumio Oinuma, Akihiko Kaji, Kenichi Ohkuwa, Kazuhiro Takeda, Satoshi Suzuki
  • Patent number: 6142922
    Abstract: A conductive roll to be used as a developing roll, a charging roll, a transfer roll or the like in an electrophotographic apparatus such as a copying machine, a printer or a facsimile, of the present invention comprises a base rubber layer formed on a peripheral surface of a shaft, an intermediate layer formed on a peripheral surface of the base rubber layer, and a surface layer formed on a peripheral surface of the intermediate layer, the surface layer being composed of a resin composition comprising:(A) a silicone-grafted acrylic polymer which comprises repeating units represented by the following general formula (1), wherein an acrylic polymer portion of the silicone-grafted acrylic polymer exclusive of a structural portion derived from a siloxane has a glass-transition temperature of -35 to 30.degree. C.:--(Y).sub.k -- --(Z).sub.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: November 7, 2000
    Assignee: Tokai Rubber Industries, Ltd.
    Inventors: Hitoshi Yoshikawa, Shoji Arimura, Akihiko Kaji, Kenichi Ohkuwa
  • Patent number: 5993366
    Abstract: A low hardness conductive roll, wherein an innermost layer is formed on the peripheral surface of a shaft body, an intermediate layer is formed on the peripheral surface thereof, and further an outermost layer is formed on the peripheral surface thereof, and wherein the outermost layer is formed of a resin composition comprising the following Component (A) so that good toner electrification property and toner releasability are achieved: ##STR1## wherein Y denotes a linear structural portion derived from an acrylic monomer, Z denotes a structural portion derived from an acrylic monomer and also has a structural portion derived from siloxane, and k and n denote positive numbers of 1 to 3,000, respectively.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: November 30, 1999
    Assignee: Tokai Rubber Industries, Ltd.
    Inventors: Akihiko Kaji, Kenichi Ohkuwa, Hitoshi Yoshikawa, Shoji Arimura