Patents by Inventor Yasufumi Mizuta

Yasufumi Mizuta 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: 5274084
    Abstract: An azo compound represented by the following general formula IA and an electrophotographic photosensitive member comprising a photosensitive layer containing the azo compound: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different from each other and indicate a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, a carboxy group, an alkoxy carbonyl group, an acyl group, an aryl group, a halogen group or a cyano group, respectively; R.sup.14 indicates a hydrogen atom, a halogen group, an alkyl group, an alkoxy group, an aryl group, an amino group, a cyano group, a nitro group or a sulfoxide group; and A indicates a coupler residue having an acceptor property.
    Type: Grant
    Filed: November 24, 1992
    Date of Patent: December 28, 1993
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Eiichi Miyamoto, Yasuyuki Hanatani, Hiroaki Iwasaki, Yasufumi Mizuta, Akihiko Kawahara
  • Patent number: 5260157
    Abstract: An electrophotographic photosensitive element comprising a photosensitive layer and a surface protective layer on the photosensitive layer, the surface protective layer comprising a thermosetting silicone resin, and a methyl-butyl etherified melamine-formaldehyde resin in an amount of from 0.1 to 30 parts by weight per 100 parts by weight of the non-volatile solid components of the thermosetting silicone resin, an electrophotographic photosensitive element comprising a photosensitive layer and a surface protective layer on the photosensitive layer, the surface protective layer comprising a thermosetting silicone resin, and an acrylic copolymer having an average molecular weight of 6,000 or less in an amount of from 0.
    Type: Grant
    Filed: October 19, 1990
    Date of Patent: November 9, 1993
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Yasufumi Mizuta, Akihiko Kawahara, Kaname Nakatani, Nariaki Tanaka
  • Patent number: 5185228
    Abstract: The present invention provides an electrophotosensitive material having a layer containing a binding resin, a charge transferring material and a biphenyl derivative of the following formula [I], or a compound of which energy level in a triplet state is not more than the energy level in an excited state of the charge transferring material. The present invention prevents the charge transferring material from being decreased in charge amount and sensitivity due to light irradiation: ##STR1## wherein R.sup.1 is an aryl or aralkyl group.
    Type: Grant
    Filed: August 14, 1990
    Date of Patent: February 9, 1993
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Tatsuo Maeda, Masato Katsukawa, Hiroaki Iwasaki, Yasufumi Mizuta
  • Patent number: 5135834
    Abstract: An electrophotographic photosensitive element having a layer containing polyvinyl acetal, wherein the layer is formed by coating a coating composition containing the polyvinyl acetal and being compounded with a solution comprising an acetylacetone complex salt, an alcohol and water, and a process of producing an electrophotographic photosensitive element having a layer containing polyvinyl acetal, wherein the layer is provided by the steps of:preparing (A) a solution of an acetylacetone complex salt dissolved in a mixed solvent of an alcohol and water, and (B) a solution containing polyvinyl acetal;mixing the solutions (A) and (B) to provide a coating composition (C);coating the coating composition (C) on a constituting layer or a conductive substrate; and drying.
    Type: Grant
    Filed: October 29, 1990
    Date of Patent: August 4, 1992
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Yasuyuki Hanatani, Yasufumi Mizuta, Kaname Nakatani
  • Patent number: 5063126
    Abstract: This invention presents an electrophotographic photosensitive material wherein a charge transporting layer and a charge generating layer are laminated in this order on a conductive substrate, and the charge generating layer contains N-type dye and P-type dye at a ratio of 40/60 to 90/10 (N-type dye/P-type dye) by weight.This electrophotographic photosensitive material is especially superior in reproductivity of red-colored originals as well as having a high sensitivity.
    Type: Grant
    Filed: November 16, 1989
    Date of Patent: November 5, 1991
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Kaname Nakatani, Yasuyuki Hanatani, Yasufumi Mizuta