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:
Jun. 14, 1977
Filed:
Sep. 22, 1975
AGFA-Gevaert, A.G., Leverkusen, DT;
Abstract
An electric charge is created on a moving reproduction carrier by each of a plurality of electrodes extending in a line perpendicular to the direction of transport of the reproduction carrier. Each of the signals applied to the electrodes has an amplitude corresponding to the density of the corresponding point of the original. The charge created by the electrode has undesirable variations resulting from differences in the electrode characteristics and from differences in the amplifiers amplifying the signal before application to each electrode. After each charge distribution from a copy has been created, a test signal is supplied to the inputs of all amplifiers. This creates a test charge distribution on the reproduction carrier. After developing of the reproduction carrier the test line created by developing of the test charge distribution is scanned photoelectrically. A differential amplifier compares each of the so-scanned signals with a reference signal and furnishes an error signal as a function of the difference therebetween. The error signal is utilized to vary the gain of the amplifier associated with the electrode.