Patents by Inventor Hiroji Kumagai

Hiroji Kumagai 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: 4592977
    Abstract: The present invention relates to a lithographic printing plate which can eliminate disadvantages of conventional zinc oxide master papers and has sensitivity sufficient for practical use in respect of long wavelength laser light. The invention contemplates to provide the lithographic printing plate which is fabricated by charging an electrophotographic plate involving a photoconductive layer on a conductive substrate, the photoconductive layer being prepared by dispersing a mixture containing 50 wt % or less of a phthalocyanine pigment/(zinc oxide and zinc sulfide) into a binder resin, exposing the electrophotographic plate to an image to form the electrostatic latent image, developing the exposed electrophotographic plate by the use of an ink receptive toner, and fixing the plate thus developed.
    Type: Grant
    Filed: June 19, 1984
    Date of Patent: June 3, 1986
    Assignees: Toppan Printing Co., Ltd., Toyo Ink Mfg. Co., Ltd.
    Inventors: Tsutomu Naganuma, Sigeru Hirayama, Hiroji Kumagai, Manabu Sawada, Tsuneo Tanaka, Isao Kumano
  • Patent number: 4268158
    Abstract: A dry planographic printing apparatus having a photosensitive plate feed mechanism for feeding a photosensitive plate which includes an electrically conductive support and a photoconductive layer formed on the support, the photoconductive layer includes a resin binder and a photoconductive powder dispersed in the binder. The printing apparatus includes mechanisms for charging the photosensitive plate without irradiation by light and then image-exposing the resultant photosensitive plate, and finally developing by use of a conductive toner and fixing of the conductive toner. The toner is transferred to a sheet of transfer material and is then fixed. A delivery mechanism is provided for delivering the transfer material having the fixed toner, and a plate take-out mechanism is provided for taking out the dry planographic printing plate after a predetermined amount of printing.
    Type: Grant
    Filed: December 21, 1978
    Date of Patent: May 19, 1981
    Assignee: Toppan Printing Co., Ltd.
    Inventors: Tsutomu Naganuma, Hisao Hoshi, Hiroji Kumagai, Kaneki Yoshida
  • Patent number: 4209551
    Abstract: A method for manufacturing a phosphor screen for a color picture tube is disclosed which comprises the steps of transferring an ink pattern contained on an intaglio having a surface comprising ink receiving portions with a depth of 10.mu. or more, said ink containing 15 to 90% by volume of phosphor powder, by rotatably moving at a first speed a transcriber having a cylindrical surface covered with a layer of a soft material along the surface of the intaglio in order to apply the ink pattern onto the cylindrical surface of the transcriber and transcribing said ink pattern from said transcriber onto an object to be printed for a color picture tube by rotatably moving the transcriber at a second higher speed along the surface of said object.
    Type: Grant
    Filed: December 28, 1977
    Date of Patent: June 24, 1980
    Assignee: Toppan Printing Co., Ltd.
    Inventors: Tatsuo Masaki, Keiji Miyajima, Kenzo Fukuyoshi, Hiroji Kumagai
  • Patent number: 4175958
    Abstract: This invention provides a dry planographic printing plate prepared by forming on an electrically conductive support a photoconductive layer composed of a binder and photoconductive powder dispersed in the binder, charging and then image-exposing a resultant photosensitive plate, and finally developing by means of a conductive toner and fixing the conductive toner. This invention also provides a dry planographic printing method including reversal-developing said printing plate by using a toner, transferring the toner to a sheet of transfer material, and then fixing the toner, as well as an apparatus used in said printing method.
    Type: Grant
    Filed: December 20, 1977
    Date of Patent: November 27, 1979
    Assignee: Toppan Printing Co., Ltd.
    Inventors: Tsutomu Naganuma, Hisao Hoshi, Hiroji Kumagai, Kaneki Yoshida