Patents by Inventor Ravi Sampath

Ravi Sampath 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).

  • Method and apparatus for charging a photoconductive surface to a uniform potential
    Patent number: 5247328
    Abstract: An apparatus for charging a photoconductive surface to a substantially uniform potential in a printing machine having a cleaning station for cleaning the surface and an exposure station for exposing the surface to a light source includes a first mechanism for charging the surface to a substantially uniform potential of a first polarity after the surface is cleaned at the cleaning station. The apparatus further includes a second mechanism for charging the surface to a substantially uniform potential of a second polarity opposite to the first polarity after the surface is charged to the substantially uniform potential of the first polarity by the first charging mechanism and before the surface is exposed to the light source at the exposure station.
    Type: Grant
    Filed: September 15, 1992
    Date of Patent: September 21, 1993
    Assignee: Xerox Corporation
    Inventors: Clive R. Daunton, John J. Kopko, Ravi Sampath
  • Automatic background control for an electrostatic copier
    Patent number: 4912508
    Abstract: A document background control system having a sensor in the optical path of a reproduction machine to sense the background of a document in the copy mode during the scanning of the document to adjust the illumination of the document and also includes a control to adjust the charging potential on the photoconductor in response to document background that is non-white.
    Type: Grant
    Filed: March 14, 1988
    Date of Patent: March 27, 1990
    Assignee: Xerox Corporation
    Inventors: David T. Zawadzki, Timothy W. Jacobs, Ravi Sampath, John W. Prebola