Two dimensional process control system for an electrostratographic printing machine

摘要

An electrophotographic printing machine having an imaging member with a surface adapted to move along a preselected path in a process direction, the electrophotographic printing machine includes a charge control system, incorporating charging device for applying different voltage potentials on the imaging surface in the process direction. An exposure system is provided for discharging each of the different voltage potentials with different exposure levels in a second direction substantially perpendicular to the process direction to form segments having different voltage potentials. The charging device has a coronode wire and a screen or grid wires. The charging device acts as a constant voltage charging device and, in fact, acts as an indicator of the potentials voltage on the photoreceptor. An array of electrostatic voltmeter (ESV) provides a second voltage potentials measurements to complete the requirements to estimate the electrical parameter.