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:
Aug. 15, 1978
Filed:
Nov. 26, 1976
Robert F Buchheit, Pittsford, NY (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A d.c. type electrostatic voltmeter for use in measuring voltage potentials on a surface such as the photoconductive surface of an electrostatic type reproduction machine. Circuitry is provided to automatically compensate for variations the electrometer probe-to-surface spacing, the circuitry including an a.c. signal source, a circuit to superimpose an a.c. signal from the source through the input and onto the d.c. signal output of the electrometer probe, an amplitude detector to detect changes in the a.c. signal source amplitude resulting from changes in the probe-to-surface spacing, a feedback control responsive to such amplitude changes to adjust the amplitude of the combined d.c./a.c. signal to maintain a prescribed a.c. amplitude, and a filter to thereafter remove the a.c. signal leaving the corrected d.c. signal.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile