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:
May. 21, 1991
Filed:
Nov. 29, 1989
Paul V Sadwick, Dayton, OH (US);
AM International, Inc., Chicago, IL (US);
Abstract
In a high speed electrophotographic printing apparatus and method wherein a charge of desired polarity and potential is applied uniformly to a photoconductive surface of a rapidly rotating drum, an improvement is provided which comprises an electrometer located adjacent the drum surface for sensing and measuring the charge imparted to the surface. The electrometer is operatively connected through a programmable logic controller to a variable power output that drives the corona array to impart the charge to the drum surface. Irregularities in charge potential imparted to the surface are thereby measured by the electrometer with appropriate adjustment being made in the charge applied to the drum by the corona array.