Patents by Inventor Hirohisa Otsuka

Hirohisa Otsuka 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: 5638158
    Abstract: At least a photosensitive drum 2 and charge roller 9 are attached to a unit 8 so that the photosensitive drum 2 and charge roller 9 can be freely attached to and detached from an apparatus body 1 in unison with the unit case 8, and the charge roller 9 can be freely brought into and out of contact with the surface of the photosensitive drum 2. The apparatus body 1 is provided with pressure cams 5a and 5b adapted to cause the charge roller 9 to be brought into and out of contact with the surface of the photosensitive drum 2.
    Type: Grant
    Filed: March 14, 1995
    Date of Patent: June 10, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Sanpe, Hirohisa Otsuka, Kazuhisa Sudo
  • Patent number: 5585896
    Abstract: In an image forming apparatus, a charging member, image transfer member or similar contact member contacts an image carrier implemented as a photoconductive element. Even when a voltage is applied to the contact member in a relatively low temperature environment, the contact member is provided with an adequate charge potential or an image transfer potential.
    Type: Grant
    Filed: November 9, 1994
    Date of Patent: December 17, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Kouichi Yamazaki, Sadao Takahashi, Nobuo Kikuchi, Kentaro Matsumoto, Tadashi Hayakawa, Yoshiaki Miyashita, Takeshi Tabuchi, Naomi Misago, Hirohisa Otsuka
  • Patent number: 4956671
    Abstract: A device for cleaning a wire of a corona discharge type charger installed in an electrophotographic copier or similar image recording apparatus such as a charger for charging a photoconductive element, a transfer charger or a separation charger. The device includes a pair of cleaning pads which clean the wire by individually holding diametrically opposite portions of the periphery of the wire, i.e. a portion which faces the surface of the photoconductive element to be charged and a portion which is remote from the surface of the same element. The cleaning pads act on the wire only when the pads and the wire are moved in one predetermined direction relative to each other.
    Type: Grant
    Filed: October 27, 1988
    Date of Patent: September 11, 1990
    Assignee: Ricoh Company, Ltd.
    Inventor: Hirohisa Otsuka
  • Patent number: 4921236
    Abstract: A recycling automatic document feeder usable with an electronic copier and others includes a reversing section for feeding a document to a glass platen of the copier while turning it over. The document feeder adapts itself to a single-face and a double-face copy mode as well as to a document through type and an optical scan type exposing system.
    Type: Grant
    Filed: January 4, 1989
    Date of Patent: May 1, 1990
    Assignee: Ricoh Company, Ltd.
    Inventors: Sirou Saeki, Sunao Ikeda, Hirohisa Otsuka, Nobuyuki Yanagawa