Patents by Inventor Kohji Ichimura

Kohji Ichimura 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: 6025857
    Abstract: A photosensitive member which has an electrode provided on the front side and a photoconductive layer stacked on the electrode, the photosensitive member being disposed face-to-face with an electrostatic information recording medium that includes a charge retaining layer having an electrode provided on the rear side, either in or out of contact with each other, to carry out exposure with a voltage being applied between the two electrodes, thereby forming an electrostatic charge pattern on the electrostatic information recording medium in accordance with an exposure light pattern. The layer arrangements of the photosensitive member and the photoconductive layer as well as the method of forming the photoconductive layer are improved so that electrostatic information can be recorded on the electrostatic information recording medium with high sensitivity and it is also possible to improve the contrast ratio of the information charge at the exposed region to that at the unexposed region.
    Type: Grant
    Filed: August 30, 1995
    Date of Patent: February 15, 2000
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Hiroyuki Obata, Minoru Utsumi, Kohji Ichimura
  • Patent number: 5981122
    Abstract: Electric discharge between a photosensitive member and a charge retaining medium is ON/OFF controlled by changing the gas pressure between these two members, so that it is possible to effect image recording in a state where a DC voltage is applied. An electric charge which is opposite in polarity to an image forming charge is uniformly formed on the charge retaining medium in advance of the image exposure, and thereafter image exposure is carried out, thereby reducing the background potential at the unexposed region and increasing the contrast potential of the electrostatic latent image formed on the charge retaining medium. In addition, it is possible to increase the voltage distribution to the photosensitive member. As a result, it is possible to improve the photosensitivity of image exposure.
    Type: Grant
    Filed: May 20, 1997
    Date of Patent: November 9, 1999
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Hiroyuki Obata, Kohji Ichimura
  • Patent number: 5665497
    Abstract: Electric discharge between a photosensitive member and a charge retaining medium is ON/OFF controlled by changing the gas pressure between these two members, so that it is possible to effect image recording in a state where a DC voltage is applied. Accordingly, it is possible to effect image recording on the charge retaining medium without the need for precise control for obtaining a high-voltage pulse and without employing an optical shutter. In addition, an electric charge that is emitted by a field is attracted to the charge retaining medium and accumulated on the surface thereof, thereby forming an electrostatic latent image, and thus making it possible to attain image recording of extremely high resolution.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: September 9, 1997
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Hiroyuki Obata, Kohji Ichimura
  • Patent number: 5298947
    Abstract: The present invention provides an image-recording process wherein the voltage applied between a photosensitive member 2 and electrostatic information recording medium 1 is put off after the lapse of a given time from the closing of an exposure shutter 13. It is thus possible to move all the generated carriers onto electrostatic information recording medium 1 and accumulate them as charges in an amount corresponding to the quantity of exposure irrespective of a voltage shutter time. It is also possible to electrically charge electrostatic information recording medium 1 or the photosensitive member 2 in advance and put on-off an electrical connection between the electrodes of the photosensitive member 2 and electrostatic information recording medium 1 to control image exposure, thereby dispensing with any external high voltage power source and obtaining a positive image.
    Type: Grant
    Filed: July 16, 1991
    Date of Patent: March 29, 1994
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Takashi Aono, Minoru Utsumi, Hiroyuki Obata, Kohji Ichimura, Masayuki Iijima
  • Patent number: 5192634
    Abstract: The a-selenium-tellurium photosensitive member according to the present invention comprises an electric charge injection preventive layer, an a-selenium-tellurium mixed vacuum evaporation layer of 0.03-0.2 .mu.m thick having tellurium concentration within the range of 20-50 wt % with uniform concentration on the deposited surface, and an electric charge transport layer, and these three layers are sequentially laminated on a transparent electrode layer. Thus, a-selenium-tellurium layer is formed in thin film, and thermal excitation carrier and injection carrier can be reduced to very low level even when tellurium concentration is increased. The increase of dark current is not very high. Panchromatic property can be provided in visible light region, and the sensitivity can be improved even in short wavelength region.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: March 9, 1993
    Assignee: Dai Nippon Printing Co., Ltd.
    Inventors: Kohji Ichimura, Minoru Utsumi