Patents by Inventor Hirohisa Ohtsuka

Hirohisa Ohtsuka 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: 5629755
    Abstract: An image forming apparatus includes a rotating photosensitive body, a charging member which is rotated in a direction opposite to a rotational direction of the photosensitive body while contacting the photosensitive body in order to uniformly charge a surface of the photosensitive body, a cleaning member for cleaning a surface of the charging member, and a device for bringing the charging member into contact with the photosensitive body or separating the charging member from the photosensitive body. The charging member is rotated contacting the cleaning member in order to clean the charging member when the charging member is separated from the photosensitive body. A surface peripheral speed of the charging member made when the charging member is separated from the photosensitive body is reduced to become slower than a surface peripheral speed of the charging member maintained when the charging member is rotated contacting the photosensitive body.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: May 13, 1997
    Assignee: Ricoh Company, Ltd.
    Inventor: Hirohisa Ohtsuka
  • Patent number: 5610691
    Abstract: An image forming apparatus includes a contact charging member which contacts a surface of an image carrier member in order to charge the surface of the image carrier member, and a cleaning member which contacts and slides on a surface of the contact charging member in order to clean the surface of the contact charging member. The image forming apparatus performs a function in such a way that after an electrostatic latent image is produced on the image carrier member which is in a charged state, toner powder is supplied to the image carrier member by a developing device in order to make the electrostatic latent image visible and then a visualized image is transferred to a transfer member. In the image forming apparatus, a maximum height of concavities and convexities formed on the surface of the contact charging member is equal to or less than an average particle diameter of the toner powder supplied by the developing device.
    Type: Grant
    Filed: October 10, 1995
    Date of Patent: March 11, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Sadao Takahashi, Hirohisa Ohtsuka, Takaaki Tawada
  • Patent number: 5572293
    Abstract: A system for cleaning a charge inducing member comprising a cleaning element for establishing relative lineal as well as rotary movement between the cleaning element and charge inducing member. Embodiments include various mechanisms for imparting axial reciprocal motion to the cleaning element and for disabling reciprocation of the cleaning element or separating the cleaning element and charging member from each other during sensitive portions of a photoduplication cycle.
    Type: Grant
    Filed: October 13, 1994
    Date of Patent: November 5, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Nobuo Kikuchi, Kouichi Yamazaki, Sadao Takahashi, Kentaro Matsumoto, Tadashi Hayakawa, Yoshiaki Miyashita, Takeshi Tabuchi, Hirohisa Ohtsuka, Takaaki Tawada
  • Patent number: 5526100
    Abstract: An image recording apparatus includes a toner supplying unit for supplying fresh toner to a toner chamber via a toner supplying passage; a toner collecting unit for collecting toner which remains on a photosensitive medium after an image on the photosensitive medium is transferred to a sheet of paper, and for supplying the collected toner to the toner chamber via a toner collecting passage; a toner ratio detecting unit for detecting whether or not a ratio of the collected toner to the fresh toner relating to a quantity of to toner contained in the toner chamber is greater than a maximum allowable ratio; and a toner quantity control for it for allowing the toner supplying unit to supply free toner to the toner chamber when the ratio relating to the quantity of toner contained in the toner chamber is detected to be greater than the maximum allowable ratio.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: June 11, 1996
    Assignee: Ricoh Company, Ltd.
    Inventors: Naomi Misago, Hirohisa Ohtsuka