6 - 31.3 Technical explanation of printing processes1.3.1 ChargeIn "Charge" process, the surface of drum that rotates at regulated speed is negatively chargedevenly by discharging of BCR (Bias Charge Roll). BCR contacts the drum at all times, and follows the rotation of the drum.BCR is a conductive roll, to which negative voltage of overlapped AC voltage is applied fromHVPS and it discharges to the surface of the drum.Surface of drum is negative charged evenly by DC bias voltage. The surface of the drum is made of a photoconductor (insulator where not exposed to light,conductor where exposed) and the inside of it is made of a conductor (aluminum cylinder).HVPSBCRLeg_Sec06_005FA: Negative charge: Positive chargeDrumPhotoconducto rConductorLeg_Sec06_006FADrum surface -V0Leg_Sec06_007FAPotential ondrum surfaceChapter 6 Principles of Operation
