Patents by Inventor Tadashi Tonegawa

Tadashi Tonegawa 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: 5715806
    Abstract: A multi-wire saw device for slicing a semiconductor ingot and method therefore provides a plurality of spaced wires for cutting the ingot which is held by two sets of clip boards therebetween. The sets of clip boards form a holding means which may ascend and descend in order to engage the cutting wires. The multi wire saw device includes a cassette having chambers partioned by wires extending between opposite cassette ends and into which individual wafers fall. The cassette is formed with teflon resin for easy entry of the wafers.
    Type: Grant
    Filed: December 14, 1995
    Date of Patent: February 10, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tadashi Tonegawa, Junzo Wakuda
  • Patent number: 5160967
    Abstract: An apparatus for forming an image of a document, capable of charging a photoconductor by using a charging device includes a unit for detecting a value of a flowing current into the photoconductor, a unit for comparing the value of the flowing current with a predetermined life time current value of the photoconductor, and a unit for determining a layer thinning of the photoconductor at a time when the value of the flowing current exceeds the predetermined life time current value of the photoconductor so that the layer thinning is indicated.
    Type: Grant
    Filed: June 13, 1991
    Date of Patent: November 3, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Tadashi Tonegawa
  • Patent number: 5019862
    Abstract: Quality of images formed electrophotographically on a photoreceptor is improved by controllingly switching on and off a heater for the photoreceptor such that the photoreceptor temperature remains higher than the measured ambient temperature by several .degree.C. to 20.degree. plus several .degree.C. At the same time, the output of the charger for the photoreceptor or brightness of an image forming lamp is controlled according to the measured surface temperature of the photoreceptor.
    Type: Grant
    Filed: November 8, 1988
    Date of Patent: May 28, 1991
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masatsugu Nakamura, Kunio Ohashi, Shoichi Nagata, Kazuki Wakita, Katsuhiro Nagayama, Tadashi Tonegawa
  • Patent number: 4910111
    Abstract: A photoreceptor with a photoconductive layer of amorphous silicon has an overcoating layer to protect the photoconductive layer and to prevent formation of SiO.sub.x. The overcoating layer is amorphous C.sub.1-x X.sub.x, Ge.sub.1-x X.sub.x, (BNGe).sub.1-x X.sub.x or (BNC).sub.1-x X.sub.x where x is greater than or equal to 0 and smaller than 0.5 and X is H, F or Cl.
    Type: Grant
    Filed: November 8, 1988
    Date of Patent: March 20, 1990
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuki Wakita, Syoichi Nagata, Masatsugu Nakamura, Kunio Ohashi, Tadashi Tonegawa, Katsuhiro Nagayama
  • Patent number: 4757345
    Abstract: An electric photographical copying system which provides a main charger for charging the photo-conductive layer of the recording medium, an optical exposure means for projecting an image of an original onto the photo-conductive layer to make an electrostatic latent image thereon, a developing device for developing the latent image with developer, a transfer device for transferring the image developed onto a copy sheet, a cleaning device for cleaning residual developer on the photo-conductive layer and an erasing device for erasing the surface potential of the photo-conductive layer. The devices are successively activated in an order to use the recording medium repeatedly.
    Type: Grant
    Filed: January 16, 1986
    Date of Patent: July 12, 1988
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kunio Ohashi, Kazuki Wakita, Tadashi Tonegawa, Syoichi Nagata, Masatsugu Nakamura, Kazuo Maeyama
  • Patent number: 4683186
    Abstract: A photoconductive device including a conductive substrate, a photoconductive layer of amorphous silicon containing at least hydrogen and a surface protection layer applied on the photoconductive layer a dopant is added in the photoconductive layer at least near the interface with the surface protection layer, and the concentration of the dopant increases in the direction perpendicular to the interface. The surface protection layer has an optical energy gap larger than that of the photoconductive layer.A further photoconductive device comprising a conductive substrate; a photoconductive layer of amorphous silicon applied on the conductive substrate and a surface protection layer of amorphous silicon applied on said photoconductive layer wherein the surface protection layer contains oxygen, and is doped with a IIIb element.
    Type: Grant
    Filed: October 10, 1985
    Date of Patent: July 28, 1987
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kunio Ohashi, Tadashi Tonegawa, Shoichi Nagata, Masatsugu Nakamura
  • Patent number: 4643559
    Abstract: There is disclosed an electrophotographic copying method applicable to an electrophotographic copying machine providing a photo-sensitive drum (hereinafter referred to as a first drum) and a drum capable of being brought into contact with or being separated from the first drum on the surface of which an insulation film is formed (hereinafter referred to as a second drum).According to the present method, a latent image formed on the first drum is developed and, thereafter, the toner image transferred to the second drum first. The image transferred to the second drum is used to reproduce a second latent image on the first drum to obtain a copy therefrom.
    Type: Grant
    Filed: May 23, 1985
    Date of Patent: February 17, 1987
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Tadashi Tonegawa
  • Patent number: 4632894
    Abstract: A photoconductive device comprising a conductive substrate and a photoconductive layer applied on the conductive substrate, which photoconductive layer is made of amorphous silicon containing at least hydrogen, wherein the photoconductive layer contains hydroxy radicals.Another photoconductive device comprising a conductive substrate, a photoconductive layer of amorphous silicon containing at least hydrogen and a surface protection layer applied on the photoconductive layer; wherein a dopant is added in the photoconductive layer at least near the interface with the surface protection layer, and the concentration of the dopant increases in the direction perpendicular to the interface and the surface protection layer has an optical energy gap larger than that of the photoconductive layer.
    Type: Grant
    Filed: February 28, 1985
    Date of Patent: December 30, 1986
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kunio Ohashi, Tadashi Tonegawa, Shoichi Nagata, Masatsugu Nakamura