COPYRIGHT © 2001 CANON INC. 2000 2000 2000 2000 CANON iR2200/iR2800/iR3300 REV.0 MAR. 2001CHAPTER 4 IMAGE FORMATION SYSTEM4-4 P2 Controlling the Primary Charging Roller Bias2.1 OutlinePart 2>Chapter 5>4.4 “Controlling the Primary Charging Roller Bias”The machine’s primary charging is a direct charging method that uses a charging roller. Inaddition to a DC bias, the charging roller is subjected to an AC bias to ensure stable charg-ing.The following items relate to the control of primary charging:[1] Turning on/off the bias.[2] Controlling the DC bias to a specific level of voltage.[3] Controlling the AC bias to a specific level of current.[4] Controlling the photosensitive drum resistance detection mechanism (APVC control).[5] Controlling the AC bias based on the readings of the environment sensor (humidity) andthe soft counters.[6] Controlling the DC bias based on the reading of the drum sensor (temperature).F04-201-01MemoThe primary charging output enable signal is used as the AC pulse ON sig-nal when the developing bias is being controlled.DC controller PCBPrimary chargingoutput enablesignalDC biasoutputcontrol signalDC biasoutputAC biasoutputDC biasoutput ONsignalAC bias outputcontrol signalJ301-B4J136-B9J135J301-A3-A1J136-A10-A1224 VDC input frommain power supplyComposite power supply PCBPW-CPUTransformerdrive signalVoltage levelJ130-4Transformerdrive signalPhotosensitivedrumSerial communicationPrint/standby mode signalAC bias level signalDC bias level signalAPVC measurement dataPrimary ACcharging high-voltage transformerPrimary DCcharging high-voltagetransformer(T502) Primarycharging rollerDrivecontrolCurrentdetectionOutputcontrolCurrentcontrolVoltagedetectionCurrent level(APVC measure-ment)+24VDrum sensor(temperature)Environmentsensor(humidity)Measurement resultMeasurement resultJ311-A2J302-B14
