Patents by Inventor Ryoichi Kitajima

Ryoichi Kitajima 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: 8396399
    Abstract: A toner bearing member is provided which includes a conductive support, an insulation layer provided on the conductive support, multiple electrodes arranged at regular intervals on the insulation layer, a surface layer covering the multiple electrodes, comprising a polymerized compound having a specific unit, and a voltage applicator that applies a voltage between the conductive support and the multiple electrodes while periodically reversing an electric field generated therebetween.
    Type: Grant
    Filed: June 1, 2010
    Date of Patent: March 12, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuyuki Yamashita, Keiko Osaka, Ryoichi Kitajima
  • Patent number: 8369755
    Abstract: The developing device includes a developer charging member configured to charge a toner serving as a one developer; and a developer bearing member configured to bear and feed the charged toner while forming an electric field so that the toner hops. The developer bearing member includes an insulating substrate; plural electrodes arranged on the insulating substrate in a developer feeding direction to form the electric field; and an outermost layer covering the plural electrodes. The toner has a softening point of from 115 to 130° C.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: February 5, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Keiko Osaka, Yasuyuki Yamashita, Ryoichi Kitajima
  • Publication number: 20110176835
    Abstract: A toner bearing member having an electroconductive substrate, an insulation layer formed on the electroconductive substrate, multiple electrodes spaced a constant distance apart therebetween, formed on the insulation layer, and a surface layer that covers the multiple electrodes, the surface layer comprising a polymerizable material comprising a structure unit represented by the following chemical structure 1 and at least one of cyclohexanone and cyclopentanone, where R1 and R2, each, independently represent a hydrogen atom, an alkyl group, or an aryl group, or form a cyclic hydrocarbon residual group having 5 to 8 carbon atoms, R3 and R4, each, independently represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group, and “a” and “b” represent integers of 1 or 2.
    Type: Application
    Filed: January 20, 2011
    Publication date: July 21, 2011
    Inventors: Yasuyuki YAMASHITA, Ryoichi Kitajima
  • Publication number: 20100329748
    Abstract: The developing device includes a developer charging member configured to charge a toner serving as a one developer; and a developer bearing member configured to bear and feed the charged toner while forming an electric field so that the toner hops. The developer bearing member includes an insulating substrate; plural electrodes arranged on the insulating substrate in a developer feeding direction to form the electric field; and an outermost layer covering the plural electrodes. The toner has a softening point of from 115 to 130° C.
    Type: Application
    Filed: June 23, 2010
    Publication date: December 30, 2010
    Applicant: RICOH COMPANY, LTD.
    Inventors: Keiko OSAKA, Yasuyuki Yamashita, Ryoichi Kitajima
  • Publication number: 20100303509
    Abstract: A toner bearing member is provided which includes a conductive support, an insulation layer provided on the conductive support, multiple electrodes arranged at regular intervals on the insulation layer, a surface layer covering the multiple electrodes, comprising a polymerized compound having a specific unit, and a voltage applicator that applies a voltage between the conductive support and the multiple electrodes while periodically reversing an electric field generated therebetween.
    Type: Application
    Filed: June 1, 2010
    Publication date: December 2, 2010
    Applicant: RICOH COMPANY, LTD.
    Inventors: Yasuyuki YAMASHITA, Keiko Osaka, Ryoichi Kitajima
  • Patent number: 7482104
    Abstract: An image forming method, includes: forming a latent electrostatic image on a latent electrostatic image carrier; developing the latent electrostatic image with a toner to thereby form a visible image; transferring the visible image to a recording medium; and fixing the image transferred to the recording medium. The latent electrostatic image carrier includes: a support, a photoconductive layer on the support, and a surface protective layer on the support. The surface protective layer includes a reactant made by cross-linking the following: an electric charge transporting material which comprises a reactive functional group, a cross-linking resin, and a fluorine surfactant. The toner comprises an inorganic fine particle which defines an effective inorganic fine particle amount in a range of 0.8% by mass to 3.
    Type: Grant
    Filed: April 16, 2008
    Date of Patent: January 27, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Maiko Kondo, Hidetoshi Kami, Naohiro Toda, Ryoichi Kitajima, Hiroshi Nagame, Narihito Kojima, Yoshiaki Kawasaki
  • Publication number: 20080193865
    Abstract: An image forming method, includes: forming a latent electrostatic image on a latent electrostatic image carrier; developing the latent electrostatic image with a toner to thereby form a visible image; transferring the visible image to a recording medium; and fixing the image transferred to the recording medium. The latent electrostatic image carrier includes: a support, a photoconductive layer on the support, and a surface protective layer on the support. The surface protective layer includes a reactant made by cross-linking the following: an electric charge transporting material which comprises a reactive functional group, a cross-linking resin, and a fluorine surfactant. The toner comprises an inorganic fine particle which defines an effective inorganic fine particle amount in a range of 0.8% by mass to 3.
    Type: Application
    Filed: April 16, 2008
    Publication date: August 14, 2008
    Inventors: Maiko KONDO, Hidetoshi Kami, Naohiro Toda, Ryoichi Kitajima, Hiroshi Nagame, Narihito Kojima, Yoshiaki Kawasaki
  • Patent number: 7386256
    Abstract: An image forming method, includes: forming a latent electrostatic image on a latent electrostatic image carrier; developing the latent electrostatic image with a toner to thereby form a visible image; transferring the visible image to a recording medium; and fixing the image transferred to the recording medium. The latent electrostatic image carrier includes: a support, a photoconductive layer on the support, and a surface protective layer on the support. The surface protective layer includes a reactant made by cross-linking the following: an electric charge transporting material which comprises a reactive functional group, a cross-linking resin, and a fluorine surfactant. The toner comprises an inorganic fine particle which defines an effective inorganic fine particle amount in a range of 0.8% by mass to 3.
    Type: Grant
    Filed: December 9, 2004
    Date of Patent: June 10, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Maiko Kondo, Hidetoshi Kami, Naohiro Toda, Ryoichi Kitajima, Hiroshi Nagame, Narihito Kojima, Yoshiaki Kawasaki
  • Patent number: 7341814
    Abstract: An electrophotographic photoconductor includes an electroconductive substrate, a photoconductive layer arranged over the electroconductive layer with or without the interposition of an undercoat layer, and a surface top layer containing a crosslinkable resin arranged over the photoconductive layer, the photoconductive layer includes a charge generation layer containing a charge generating material, and a charge transport layer containing a charge transporting material, in which the surface top layer is substantially free from hydroxyl groups and residual uncured portions.
    Type: Grant
    Filed: January 7, 2005
    Date of Patent: March 11, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Hidetoshi Kami, Naohiro Toda, Yoshiaki Kawasaki, Maiko Kondo, Ryoichi Kitajima, Narihito Kojima, Hiroshi Nagame
  • Patent number: 7315722
    Abstract: An image forming apparatus, including an electrophotographic photoreceptor including: an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate, and a protective layer overlying the photosensitive layer and serving as an outermost layer, wherein the protective layer has an average abraded thickness not greater than 1 ?m after the electrophotographic image forming apparatus produces 100,000 images; a charger charging the electrophotographic photoreceptor; an irradiator irradiating the electrophotographic photoreceptor to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a toner to form a toner image on the electrophotographic photoreceptor; a transferer transferring the toner image onto a transfer sheet; and a cleaner cleaning a surface of the electrophotographic photoreceptor, wherein the cleaner comprises a cleaning brush impregnated with a resin.
    Type: Grant
    Filed: December 21, 2004
    Date of Patent: January 1, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Ryoichi Kitajima, Hidetoshi Kami, Yoshiaki Kwasaki, Naohiro Toda, Maiko Kondoh, Hiroshi Nagame
  • Publication number: 20050181291
    Abstract: An electrophotographic photoconductor includes an electroconductive substrate, a photoconductive layer arranged over the electroconductive layer with or without the interposition of an undercoat layer, and a surface top layer containing a crosslinkable resin arranged over the photoconductive layer, the photoconductive layer includes a charge generation layer containing a charge generating material, and a charge transport layer containing a charge transporting material, in which the surface top layer is substantially free from hydroxyl groups and residual uncured portions.
    Type: Application
    Filed: January 7, 2005
    Publication date: August 18, 2005
    Inventors: Hidetoshi Kami, Naohiro Toda, Yoshiaki Kawasaki, Maiko Kondo, Ryoichi Kitajima, Narihito Kojima, Hiroshi Nagame
  • Publication number: 20050158644
    Abstract: An image forming method, includes: forming a latent electrostatic image on a latent electrostatic image carrier; developing the latent electrostatic image with a toner to thereby form a visible image; transferring the visible image to a recording medium; and fixing the image transferred to the recording medium. The latent electrostatic image carrier includes: a support, a photoconductive layer on the support, and a surface protective layer on the support. The surface protective layer includes a reactant made by cross-linking the following: an electric charge transporting material which comprises a reactive functional group, a cross-linking resin, and a fluorine surfactant. The toner comprises an inorganic fine particle which defines an effective inorganic fine particle amount in a range of 0.8% by mass to 3.
    Type: Application
    Filed: December 9, 2004
    Publication date: July 21, 2005
    Inventors: Maiko Kondo, Hidetoshi Kami, Naohiro Toda, Ryoichi Kitajima, Hiroshi Nagame, Narihito Kojima, Yoshiaki Kawasaki
  • Publication number: 20050141919
    Abstract: An image forming apparatus, including an electrophotographic photoreceptor including: an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate, and a protective layer overlying the photosensitive layer and serving as an outermost layer, wherein the protective layer has an average abraded thickness not greater than 1 ?m after the electrophotographic image forming apparatus produces 100,000 images; a charger charging the electrophotographic photoreceptor; an irradiator irradiating the electrophotographic photoreceptor to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a toner to form a toner image on the electrophotographic photoreceptor; a transferer transferring the toner image onto a transfer sheet; and a cleaner cleaning a surface of the electrophotographic photoreceptor, wherein the cleaner comprises a cleaning brush impregnated with a resin.
    Type: Application
    Filed: December 21, 2004
    Publication date: June 30, 2005
    Inventors: Ryoichi Kitajima, Hidetoshi Kami, Yoshiaki Kwasaki, Naohiro Toda, Maiko Kondoh, Hiroshi Nagame