Epson EPL-N4000, Service Manual

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EPSON EPL-N4000/EPL-N4000+ Chapter 2 Operating Principles
Rev.B 69
2.4.1 Charge
The Bias Charge Roll (BCR) 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 remains in darkness. Light striking the drum discharges the
surface charge.
The BCR is a conductive roll that is positioned slightly above the
surface of the drum. The HVPS supplies the BCR with two voltages; a
negative DC charge voltage and an AC discharge voltage that is used
for electrically cleaning the drum.
Figure 2-25. Charging
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