Patents by Inventor Keizo Kitamura

Keizo Kitamura 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: 6317576
    Abstract: A magnetic member is arranged at a position on the downstream side with respect to the rotational direction of a developing sleeve, outside the developer conveyance path where the magnetism from the magnetic member has no influence on the magnetic field of the developing magnetic pole. When the magnetic member is arranged with its N pole facing the developing sleeve, the magnetic attractive force from the magnetic member weakens the developer's attraction to the peripheral surface of the developing sleeve. When the magnetic member is arranged with its S pole facing the developing sleeve, the developer being conveyed along the developer conveyance path is magnetized in such a direction as to repel the peripheral surface of the developing sleeve.
    Type: Grant
    Filed: January 21, 2000
    Date of Patent: November 13, 2001
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshihisa Ishida, Hitoshi Nagahama, Katsuaki Sumida, Takahiro Bito, Keizo Kitamura
  • Patent number: 6212339
    Abstract: An image forming apparatus includes (i) a photosensitive drum for holding an electrostatic latent image on its surface, the photosensitive drum being driven to rotate by a motor, (ii) charging means for charging the surface of the photosensitive drum so that the surface has a predetermined polarity and a predetermined potential, (iii) exposing means for forming an electrostatic latent image by exposing the charged surface of the photosensitive drum, and (iv) developing means for developing the electrostatic latent image, and is arranged so that after stop of the motor due to occurrence of a trouble, during an inertial rotation time in which the photosensitive drum rotates due to an inertial force, the exposing means executes discharge exposure with respect to a charge remaining region on the surface of the photosensitive drum.
    Type: Grant
    Filed: March 17, 2000
    Date of Patent: April 3, 2001
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Katsushi Inoue, Mitsuhiro Hasegawa, Keizo Kitamura, Tomoko Mamemoto
  • Patent number: 5983055
    Abstract: A photosensitive element is produced with a minimum amount of a conductive synthetic resin material. A draft for injection molding is formed in the inner circumferential surface as a supporting body, and a driven member provided with a gear is fixed to the end of the supporting body with a smaller inner diameter, that is, the thicker end. A driven portion in which a plurality of projections and depressions are formed alternately to be adjacent to each other in the circumferential direction is arranged on an axial end of a cylindrical supporting body made of a conductive synthetic resin, including a photosensitive layer on the outer circumferential surface. By a joint member removably engaged with the driven portion, the supporting body is rotated around the axis. In one arrangement, only the end of the supporting body is solid. In another arrangement, the supporting body is solid in the almost entire length in the axial direction.
    Type: Grant
    Filed: March 14, 1997
    Date of Patent: November 9, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takahiro Bito, Syouichi Fujita, Kouichi Takenouchi, Teruhiko Noguchi, Yukihisa Imaue, Tatsuya Itou, Ken Yamagishi, Keizo Kitamura, Tadayuki Sawai
  • Patent number: D665443
    Type: Grant
    Filed: February 8, 2012
    Date of Patent: August 14, 2012
    Assignee: Yamamoto Kogaku Co., Ltd.
    Inventors: Keizo Kitamura, Naoya Aoyama