Patents Examined by J. D. Welsh
  • Patent number: 4756992
    Abstract: A method of producing an electrostatic charge image comprising the sequential steps of: (1) bringing an electrode into proximity with a photoreceptor, the photoreceptor having a dielectric substrate and a photoconductive film intimately bonded to the substrate, the electrode having means to enable an electric field to be applied across the photoreceptor and being adapted to be brought into proximity with the substrate of the photoreceptor along a length of the electrode and charging the photoreceptor with an electrostatic charge of one polarity and projecting an image of a photograph on the receptor, (2) charging the photoreceptor with an electrostatic charge of opposite polarity, and (3) projecting a photographic image of the subject again on the photoreceptor whereby an electrostatic charge image is formed on the photoconductor surface. The invention also resides in apparatus to carry out the method.
    Type: Grant
    Filed: August 15, 1986
    Date of Patent: July 12, 1988
    Inventor: Stephen Po-Ming Cheng
  • Patent number: 4654289
    Abstract: When latent images in a magnetic printing apparatus are recorded and developed, a magnetic pattern which has one direction and which has at least two magnetic transfer regions is formed at one-dot black picture regions on a recording medium. When the black picture regions have two or more dots, beside the magnetic pattern having one direction, at least one magnetized pattern having the other direction is formed therein. A white picture region is formed by a magnetized pattern which is longer than the magnetized pattern in the black picture region and which has the other direction. The developing magnetic field is formed in the same direction as that of the other direction. A print having high resolution can be obtained by mutual action between the developing field and the magnetic field generated by the magnetized pattern for the recording.
    Type: Grant
    Filed: December 13, 1985
    Date of Patent: March 31, 1987
    Assignee: Iwatsu Electric Co., Ltd.
    Inventor: Norio Kokaji
  • Patent number: 4418136
    Abstract: An electrophotographic element comprising a photoconductive layer consisting essentially of a Bi-containing As.sub.2 Se.sub.3 layer on an electrically conductive substrate.
    Type: Grant
    Filed: May 17, 1982
    Date of Patent: November 29, 1983
    Assignee: Ricoh Co., Ltd.
    Inventor: Masahiro Kameda
  • Patent number: 4410615
    Abstract: An electrophotographic photosensitive element having a conductive support provided thereon with a photosensitive layer comprising a carrier-generating phase and a carrier-transporting phase. The carrier-transporting phase comprises a hydrazone compound to improve carrier-transporting ability having the formula ##STR1## wherein, X and Y each represent a hydrogen or a halogen, R.sub.1 and R.sub.2 each represent an aryl group which may have a substituent or substituents, and Ar represents an arylene group which may have a substituent or substituents.
    Type: Grant
    Filed: September 30, 1981
    Date of Patent: October 18, 1983
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Satoshi Goto, Akira Kinoshita, Tsuneo Wada, Yoshiaki Takei, Naoko Akashi, Hiroyuki Nomori
  • Patent number: 4361637
    Abstract: Organic electron donor compounds for use in electrophotographic constructions tend to suffer from problems of molecular weight non-uniformity and oxidation. Bis-benzocarbazole derivatives have been found to resist the oxidation and oligomerization which are a source of these problems.
    Type: Grant
    Filed: February 23, 1981
    Date of Patent: November 30, 1982
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: John J. Stofko, Jr., Kenneth G. Kneipp, Terry J. Sonnonstine