Patents by Inventor Keiko Hiraoka

Keiko Hiraoka 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: 6296978
    Abstract: The present invention provides an electrophotographic photosensitive member having a substrate and a photosensitive layer thereupon, wherein a surface layer of the photosensitive member contains a resin which is obtained by being subject to polycondensation as a monomer component only an organosilicon-modified positive hole transporting compound; a process cartridge which has, in addition to the electrophotographic photosensitive member, at least one from among a primary charging means, a developing means, and a cleaning means placed into a housing; and the image forming apparatus using the electrophotographic photosensitive member.
    Type: Grant
    Filed: April 24, 1998
    Date of Patent: October 2, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Itaru Takaya, Kazuo Yoshinaga, Yuko Sato, Katsumi Aoki, Masataka Kawahara, Keiko Hiraoka
  • Publication number: 20010002139
    Abstract: The present invention provides an image exposure apparatus comprising a substrate on which a plurality of light emitting elements are disposed. Wherein, the plurality of light emitting elements are arranged in a non-parallel relation to a longitudinal direction of the substrate.
    Type: Application
    Filed: December 27, 1995
    Publication date: May 31, 2001
    Inventor: KEIKO HIRAOKA
  • Patent number: 5910386
    Abstract: An electrophotographic photosensitive member is disclosed which has a photosensitive layer and a protection layer. The protection layer contains a particulate colloidal silica and a siloxane resin to have a contact angle of water of not less than 90.degree.. The photosensitive member has a lowered surface energy and excellent mechanical and electrical durability.
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: June 8, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuo Yoshinaga, Shunichiro Nishida, Masataka Kawahara, Keiko Hiraoka, Nobuo Kushibiki, Hideki Kobayashi, Kikuko Takeuchi, Toru Masatomi
  • Patent number: 5905008
    Abstract: An electrophotographic photosensitive member has a photosensitive layer formed on a support. A surface layer (or the outermost layer) of the photosensitive layer contains a fluorine-modified organic silicone resin represented by the following average unit formula:{F(CF.sub.2).sub.a1 -Q.sub.1 -R.sub.1.m1 SiO.sub.(3-m1)/2 }.sub.X1 {F(CF.sub.2).sub.a2 -Q.sub.2 -R.sub.2.m2 SiO.sub.(3-m2)/2 }.sub.X2 . . . {F(CF.sub.2).sub.ap -Q.sub.p -R.sub.p.mp SiO.sub.(3-mp)/2 }.sub.Xp {R.sub.1 '.sub.n1 SiO.sub.(4-n1)/2)}.sub.y1 {R.sub.2 '.sub.n2 SiO.sub.4-n2)/2 }.sub.y2 . . . {R.sub.q '.sub.nq SiO.sub.(4-nq)/2 }.sub.yqwhere R.sub.1 -R.sub.p and R.sub.1 '-R.sub.q ' are each an alkyl or aryl group; Q.sub.1 -Q.sub.p are each an alkylene group; m1-mp are each an integer of 0 to 2; n1-nq are each an integer of 0 to 3; a1-aq are each an integer; x1-y1 are each a number larger than 0; and X2-Xp and Y2 are each respectively a number of 0 or more.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: May 18, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuo Yoshinaga, Shunichiro Nishida, Keiko Hiraoka, Yayoi Nagao, Hideki Kobayashi, Toru Masatomi