Abstract: The present invention is a method and apparatus for compensating for position error inherent in a raster output scanning printing system by adjusting the intensity of image exposure to effect a correction in the output image. The invention is particularly well suited to compensate for position errors arising from a plurality of sources by first summing the errors and then applying a single compensating adjustment to the intensity of individual scan rasters based upon the position error thereof.
Type:
Grant
Filed:
June 5, 1995
Date of Patent:
May 4, 1999
Assignee:
Xerox Corporation
Inventors:
Daniel W. Costanza, Ronald E. Jodoin, Robert P. Loce
Abstract: An electrostatographic printing machine and apparatus that utilizes a two layer roll charger for contact charging of photoreceptors. The charger includes a liquid retentive foam layer fitted over an electrically conductive shaft. The shaft can be solid or porous, the later requiring a separate liquid reservoir. The second layer is a thin liquid permeable member, over the foam layer, which transmits water at a slow, but controlled rate during the rotation of the roller. The roller may rotate synchronously with the photoreceptor or be allowed to slip on the photoreceptor surface to improve uniformity and contact. The membrane increases life by controlling the runout of liquid from the repository. Also, the present invention permits charging over photoreceptor pinholes.
Type:
Grant
Filed:
November 19, 1997
Date of Patent:
April 20, 1999
Assignee:
Xerox Corporation
Inventors:
John S. Facci, Michael J. Levy, Joseph Mammino
Abstract: A printing machine and apparatus are disclosed that include an ultrasonically assisted cleaning blade to remove toner particles from an imaging surface. An ultrasonic transducer is attached to the cleaning blade to provide vibrational energy to the cleaning blade. The ultrasonic transducer concentrates vibrational energy at the blade tip for enhanced cleaning. A further element of the present invention is the addition of bias to create a strong electrostatic repulsion between the toner particles and the blade tip causing the toner to explode away from the cleaning edge, and to therefore enhance cleaning.