Print Process Description; Charge - Xerox 4400DT - Phaser B/W Laser Printer Service Manual

Print Process Description

Charge

The Bias Charge Roller (BCR) places a uniform negative electrostatic charge on the
drum surface. The drum surface is made of a photoconductive material that holds the
electrical charge as long as the drum remains in darkness. Light striking the drum
discharges the surface charge.
The BCR is a conductive roller that is positioned slightly above the surface of the
drum. The HVPS PWB supplies the BCR with two voltages: a negative DC charge
voltage and an AC discharge voltage. The negative DC voltage creates a uniform
negative charge across the surface of the drum. The AC voltage removes any residual
DC charge that was left from the previous print cycle.
Block Diagram of the Drum Charge Process — Side View
Phaser 4400 Laser Printer Service Manual 8-5