Patents by Inventor Shigeto Ohta

Shigeto Ohta 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: 4485159
    Abstract: In an electrophotographic light-sensitive material comprising at least one electric charge generation layer comprising a charge generating substance and a binder resin therefor and at least one electric charge transport layer on an electrically conductive base, said electrophotographic light-sensitive material is a laminate type electrophotographic light-sensitive material wherein the binder resin for the electric charge generating substance contains at least one polyvinylpyridine resin.
    Type: Grant
    Filed: October 23, 1980
    Date of Patent: November 27, 1984
    Assignee: Copyer Co., Ltd., Canon Inc.
    Inventors: Katsunori Watanabe, Shigeto Ohta, Kiyoshi Sakai, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4419428
    Abstract: An electrophotographic light-sensitive medium is described comprising at least an electrically conductive layer, a charge generation layer and a charge transport layer, the charge generation layer containing a dis-azo compound represented by Formula (1) wherein A represents a single bond, ##STR1## B represents a coupler having aromatic properties; and R represents a group selected from hydrogen, a halogen and a lower alkyl having 1 to 4 carbon atoms.
    Type: Grant
    Filed: May 18, 1981
    Date of Patent: December 6, 1983
    Assignees: Copyer Co., Ltd., Canon Inc.
    Inventors: Kazuharu Katagiri, Shozo Ishikawa, Katsunori Watanabe, Shigeto Ohta, Makoto Kitahara
  • Patent number: 4359513
    Abstract: An electrophotographic light-sensitive medium is described comprising a light-sensitive layer containing a dis-azo compound represented by Formula (1) ##STR1## wherein A represents a coupler having aromatic properties.
    Type: Grant
    Filed: February 19, 1981
    Date of Patent: November 16, 1982
    Assignees: Copyer Co., Ltd., Canon Inc.
    Inventors: Kazuharu Katagiri, Katsunori Watanabe, Shigeto Ohta, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4359515
    Abstract: An electrophotographic light-sensitive medium comprising a light-sensitive layer containing a dis-azo compound represented by Formula (1) ##STR1## wherein A represents a single chemical bond, a divalent hydrocarbon group containing a conjugated double bond, a divalent hydrocarbon group containing a nitrogen atom in a conjugated double bond, or a divalent heterocyclic group which may be condensed with a benzene ring or substituted and forms a conjugated double bond system in combination with the adjacent azomethine groups, and B and B', which may be the same or different, each represents a coupler having aromatic properties.
    Type: Grant
    Filed: February 25, 1981
    Date of Patent: November 16, 1982
    Assignees: Copyer Co., Ltd., Canon Inc.
    Inventors: Kazuharu Katagiri, Katsunori Watanabe, Shigeto Ohta, Shozo Ishikawa, Makoto Kitahara
  • Patent number: 4356243
    Abstract: An electrophotographic light-sensitive medium is described comprising at least an electrically conductive layer, a charge generation layer and a charge transport layer, the charge generation layer containing a dis-azo compound represented by Formula (1) ##STR1## wherein A is a coupler having aromatic properties, and B is a group selected from hydrogen, halogen, lower alkyl having 1 to 4 carbon atoms and lower alkoxy having 1 to 4 carbon atoms.
    Type: Grant
    Filed: February 19, 1981
    Date of Patent: October 26, 1982
    Assignee: Copyer Co., Ltd.
    Inventors: Shozo Ishikawa, Kazuharu Katagiri, Katsunori Watanabe, Shigeto Ohta, Makoto Kitahara
  • Patent number: 4268595
    Abstract: An electrostatic recording material comprising a support having formed thereon a dielectric layer composed of a terpolymer consisting of (a) methacrylic acid, (b) a monomer selected from the group consisting of (1) acrylic acid esters containing at least 4 carbon atoms and (2) methacrylic acid esters containing at least 5 carbon atoms, and (c) a monomer selected from the group consisting of (1) acrylic acid esters containing at least 4 carbon atoms and (2) methacrylic acid esters containing at least 5 carbon atoms, wherein monomer (b) and monomer (c) are different and at least one of the monomers (b) and (c) is an acrylic acid ester containing at least 11 carbon atoms or a methacrylic acid ester containing at least 8 carbon atoms, and a method for producing an electrostatic recording material, which comprises converting such a terpolymer to a water-soluble or water-emulsifiable salt of the terpolymer in which about 20 to 100 mol% of the carboxyl groups present form a salt with ammonia and/or a volatile amine,
    Type: Grant
    Filed: November 5, 1979
    Date of Patent: May 19, 1981
    Assignee: Copyer Co., Ltd.
    Inventors: Kazuharu Katagiri, Shozo Ishikawa, Shigeto Ohta, Makoto Kitahara