Step1: Charge - Lexmark C950 Service Manual

Step1: Charge

Voltage is sent from the high-voltage power supply (HVPS) to the charge roll, which places a uniform negative
electrostatic charge on the surface of the drum. The drum surface is made of a photoconductive material that
holds an electrical charge as long as the drum is not exposed to light. Light striking the drum causes the surface
charge to neutralize.
Photoconductive
Surface
Conductive Tube
The charge roll is a conductive roll that is positioned slightly above the surface of the drum. The HVPS supplies
the charge roll with two voltages: a negative DC charge voltage and an AC discharge voltage that is used for
electrically cleaning the drum.
Photoconductive
Surface
Conductive Tube
Charge roll
(-VDC)
DRUM
Ground
Charge roll
(-VDC)
DRUM
Ground
HVPS
(-VDC)
Ground
Drum Surface
Drum Surface
Image Voltage
0V
HVPS
(-VDC)
Ground
Drum Surface
Drum Surface
Image
Voltage
0V
5058-030
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-VDC value
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