The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 18, 1977
Filed:
Nov. 05, 1974
John E Courtney, Fairport, NY (US);
Charles J Urso, Webster, NY (US);
Charles D Wilson, Pittsford, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A copier or reproduction machine of the type having a photoconductive plate, corona generating means to charge the plate in preparation for imaging thereof, exposure means to expose the charged plate to a light image of the original being copied, developer means to apply developing material to the electrostatic image, and transfer means for transferring the developed image to a support material, i.e., a copy sheet. To enable the electrostatic development field between the photoconductive plate and the developer section to be controlled and thereby enhance development, an automatic potential controller, which includes an electrometer, is provided. The electrometer includes a probe section arranged to sense voltages on the plate, the electrometer serving to provide a signal reflecting plate potentials. The electrometer signal is used by the controller to automatically adjust the electrostatic development field, as by controlling the voltage bias applied to the developer. The electrometer includes its own internal power supply for the electrometer components, and circuit means are provided to utilize the internal power supply, regulated by the controller itself in response to changes in the electrostatic development field, as the source of bias for the developer and for the electrometer itself thereby obviating the need for separate and duplicate power supplies.