Apparatus and method for controlling electrical parameters of an imaging surface

摘要

To control an electrical parameter of an imaging surface (20), a patch generator (34, 16,37) records a first control patch at a first voltage level and a second control patch at a second voltage level on the imaging surface. An electrostatic voltmeter (ESV)(33) measures voltage potentials associated with the first and second control patches. A processor (12), in communication with said patch generator, calculates electrical parameter of the imaging surface from the measured voltage potentials from said first and second control patches. The processor determines a deviation between the calculated electrical parameter values and setup values. Then, the processor can produce and send a feedback error signal to said patch generator if said deviation exceeds a threshold level. The patch generator can record a third control patch at a third voltage level on the imaging surface upon reception of said error signal. The ESV senses said third control patch. The processor can calculate electrical parameters of the imaging surface from the measured voltage potential of the third control patch and can determine a correction factor. The charging device, exposure system and developer are adjusted in accordance to the correction factor. <IMAGE>