Patents by Inventor Yuji Nakayama

Yuji Nakayama 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: 6240269
    Abstract: An electrophotographic process is implemented with improved ghost memory and with high chargeability even under circumstances of increased process speed or compactified structure and the electrophotographic process forms an image on a photosensitive member having a photosensitive layer through a series of steps including steps of charge elimination, charging, latent image exposure, and development to form a toner image, wherein light used in the latent image exposure step is light of a wavelength within such a range that a value of (optical memory before charging)/(sensitivity) of the photosensitive layer is not more than 1.5 times a minimum value. The optical memory before charging means lowering in chargeability due to light irradiation before charging.
    Type: Grant
    Filed: April 29, 1999
    Date of Patent: May 29, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kaya, Masaya Kawada, Tetsuya Karaki, Toshiyuki Ehara, Yuji Nakayama
  • Patent number: 6233417
    Abstract: An image forming apparatus which largely improves the reliability of electrophotographic apparatuses and can accommodate their extremely large productivity comprises an image forming part which forms toner images on an image carrying member, an image transfer part which transfers the toner images on the image carrying member onto a transfer material, and a cleaning part which removes post-transfer residual toner left on the image carrying member after the images are transferred onto the transfer material by the image transfer part, wherein the image carrying member is an amorphous silicon photosensitive member and an initial average gradient &Dgr;a of the photosensitive member is 0.0001 to 0.005.
    Type: Grant
    Filed: July 8, 1999
    Date of Patent: May 15, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuji Nakayama, Koji Yamazaki, Masaya Kawada, Takaaki Kaya, Hironori Owaki
  • Patent number: 6226479
    Abstract: An electrophotographic amorphous silicon photosensitive member is used for an electrophotographic apparatus that forms images by the electrophotographic method, and an image forming apparatus uses this photosensitive member, which includes a drum-shaped cylindrical conductive substrate, and a photosensitive layer that contains amorphous silicon, thus structuring an electrophotographic photosensitive drum. Then, the outer diameter of this photosensitive drum is configured to be gradually smaller from the vicinity of the central portion thereof in the generatrix direction to both ends in the longitudinal direction, hence making it possible to enhance the cleaning effect on residual toner.
    Type: Grant
    Filed: September 16, 1999
    Date of Patent: May 1, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tetsuya Karaki, Yuji Nakayama, Masaya Kawada, Takaaki Kaya
  • Patent number: 6169868
    Abstract: The present invention relates to an electrophotographic apparatus in which maximum potential difference &Dgr;VD (volt) in a potential of a dark portion of the electrostatic image in the longitudinal direction, maximum potential difference &Dgr;VL in a potential of a light portion of the electrostatic image in the longitudinal direction, a value a (1/volt) represented by (variation amount in density, in the longitudinal direction, in the image formed by developing the light portion with the developing means)/(the maximum potential difference &Dgr;VD) and a value b (1/volt) represented by (variation amount in density, in the longitudinal direction, in the image formed by developing the light portion with the developing means)/(the maximum potential difference &Dgr;VL) satisfy a relation: 0.3≦a×&Dgr;VD+b×&Dgr;VL≦0.3 in which 100≧|&Dgr;VD|≧20 and 100≧|&Dgr;VL|≧20.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: January 2, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koji Yamazaki, Yuji Nakayama, Masaya Kawada, Hironori Ohwaki
  • Patent number: 6122467
    Abstract: In order to reduce the cost of a photosensitive member and to prevent the fluctuation in image density and the image smear by highly precise temperature control, the image forming apparatus of the present invention includes: a cylindrical photosensitive member with a conductive substrate having a thickness not smaller than 0.1 mm and smaller than 2.5 mm, and a light-receiving layer having a photoconductive layer on the conductive substrate, the light-receiving layer containing at least amorphous silicon; and a charging device for charging the photosensitive member, wherein the photoconductive layer has a thickness not smaller than 5 .mu.m and smaller than 20 .mu.m, and wherein the charging device is a device for contacting a charging member with the surface of the photosensitive member and applying a voltage to the charging member to charge the photosensitive member.
    Type: Grant
    Filed: May 13, 1999
    Date of Patent: September 19, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Toshiyuki Ehara, Yuji Nakayama, Masaya Kawada, Hironori Owaki
  • Patent number: 6110629
    Abstract: A cylindrical, photosensitive member is disclosed which has a photosensitive layer comprising amorphous silicon provided on an electroconductive substrate, and in which the thickness of the electroconductive substrate is not less than 0.1 mm but less than 2.5 mm, thereby accomplishing cost reduction of the photosensitive member and also accomplishing prevention of variations of image density and image smearing by high-accuracy temperature control.
    Type: Grant
    Filed: May 13, 1999
    Date of Patent: August 29, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Toshiyuki Ehara, Yuji Nakayama, Tetsuya Karaki, Hironori Owaki
  • Patent number: 6055404
    Abstract: In order to prevent uneven shaving of a light receiving member and fusion of a developer, a surface of the light receiving member after development and transfer of the developer is scrape-cleaned with an elastic rubber blade, the wear loss of the light receiving member after copying steps on transfer sheets is within a range of not less than 1 .ANG./10,000 rotations nor more than 10 .ANG./10,000 rotations.
    Type: Grant
    Filed: May 11, 1999
    Date of Patent: April 25, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Koji Yamazaki, Toshiyuki Ehara, Yuji Nakayama, Hironori Ohwaki
  • Patent number: 5950938
    Abstract: A fixed roller is laterally axially supported by a movable body so as to ow an axial center line of the fixed roller to extend in parallel to a lateral direction, and driven to rotate an upper peripheral surface of the fixed roller backward, and a plurality of split press rollers respectively having the axes inclined by a predetermined angle with respect to an axial center line of the fixed roller as viewed in plan are arranged in a row in a lateral direction above the fixed roller in the manner of supporting the split press rollers by press roller frames. The split press rollers are energized to the descending side by oil-hydraulic cylinders respectively provided between a frame of the body and the press roller frames so as to bring the lower peripheral surface side of each split press roller into contact with the upper peripheral surface of the fixed roller under the action of pressure.
    Type: Grant
    Filed: May 29, 1998
    Date of Patent: September 14, 1999
    Assignees: Director General of Hokkaido National Agricultural Experiment Station, Takakita Co., Ltd
    Inventors: Kunio Nishizaki, Yoichi Shibata, Yasuhiro Yokochi, Yuji Nakayama
  • Patent number: 5621511
    Abstract: The present invention provides a fixing apparatus comprising a heat body heated by a heater and adapted to convey a recording sheet, temperature detection means for detecting a temperature of the heat body, energization control means for controlling energization of the heater in such a manner that a detection temperature detected by the temperature detection means is maintained to a set temperature, and selection means for selecting either extension of a sheet feed interval or temporary interruption of a fixing operation, when the detection temperature detected by the temperature detection means exceeds a predetermined fixing mode change temperature.
    Type: Grant
    Filed: April 19, 1995
    Date of Patent: April 15, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventor: Yuji Nakayama
  • Patent number: 4665957
    Abstract: A counterpressure liquid filling device for a container (1) comprises a gas discharge passage (9a) for discharging the pressurized gas of the container (1) into the atmosphere, the gas discharge passage (9a) being branched into a first branch discharge conduit (12), one end of which is communicated with the neck of the container (1), and a second branch discharge passage (13), one end of which is communicated with the container at a position where the quantity of the liquid to be filled is determined, the other ends of both the first branch discharge conduit (12) and the second branch discharge passage (13) being communicated with a valve operating chamber (11). A gas flow control valve (10) is housed in the valve operating chamber (11).
    Type: Grant
    Filed: October 17, 1985
    Date of Patent: May 19, 1987
    Assignee: Kirin Beer Kabushiki Kaisha
    Inventors: Toshio Suzuki, Takeshi Saegusa, Toshimitsu Takasu, Yuji Nakayama, Yutaka Yamaguchi