CHAPTER 5 IMAGE FORMATION SYSTEMCOPYRIGHT © 22002 CANON INC. 2000 CANON iR1600/iR2000 REV.1 JAN. 20025-42 1 Controlling the Primary Charging Roller Bias2.1 OutlineThe machine uses a charging roller for primary charging (direct charging method), and itapplies an AC bias to stabilize the charging in addition to the DC bias.The following items of control are used in relation to the primary charging control system:[1] turning on and of the bias.[2] performing constant voltage control for the DC bias.[3] performing constant current control for the AC bias.The primary charging control system is constructed as shown in the following diagram:F05-201-01TB401/TB402PrPRACON*PRACFOT*DCPWM*PRDCFOT*To developing bias circuitTo primarycharging rollerDC controller PCBPrimary charging circuitASICCPUPrimary DCbias voltagedetection circuitPrimary ACbias voltagedetection circuitDC generationcircuitAC generationcircuitComparisoncircuitComparisoncircuitSuperimposition
