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:
Feb. 27, 1979
Filed:
Apr. 19, 1977
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A photoconductive drum or sheet is movable relative to a developing electrode which is biased to a voltage which prevents smearing of the background areas of the copy. A sensing electrode is disposed upstream of the developing electrode in the direction of movement of the drum or sheet which senses the voltage on the drum or sheet. The sensing electrode is provided in a plurality of independent segments, and a computing circuit selects the voltage on the segment which is lowest in magnitude and which corresponds to a background area of the copy and applies the biasing voltage to the developing electrode in dependence on the sensed voltage. An auxiliary electrode is provided so that the combination of the sensing electrode and the auxiliary electrode is coextensive with the drum or sheet in a direction perpendicular to the movement thereof to prevent streaking of the copy. The auxiliary electrode is either electrically floated and thereby self-biased by the drum or sheet or the biasing voltage from the computing circuit is applied thereto.