COPYRIGHT © 1999 CANON INC. CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)1. Secondary Pre-Transfer Charging Bias Generation CircuitThis circuit consists of three signals (Figure 4-6y08) from the DC controller PCB, andgenerates the secondary pre-transfer charging DC bias and the secondary pre-transferAC bias for application to the secondary pre-transfer charging assembly.The application voltage to the secondary pre-transfer charging assembly is turned onand off by the secondary pre-transfer DC bias drive signal and the secondary pre-trans-fer charging AC bias drive signal. The secondary pre-transfer charging bias signal is usedto switch the level of the secondary pre-transfer charging DC bias according to environ-mental conditions.Figure 4-6082. Secondary Transfer Bias Generation CircuitThis circuit is controlled by four signals (Figure 4-609) from the DC controller PCB,and generates the secondary transfer DC (positive) bias and the secondary transfer DC(negative) bias for application to the secondary transfer belt.The secondary transfer DC (positive) bias drive signal is used to turn on and off theDC (positive) bias applied to the secondary transfer belt, while the secondary DC (nega-tive) bias drive signal is used to turn on and off the DC (negative) bias applied to the sec-ondary transfer belt.The secondary transfer bias level (constant current) control signal and the secondarytransfer bias level (constant voltage) control signals are bias level switch signals, and areused to switch the secondary transfer DC (positive) bias according to the type of paperand the conditions of the environment.Figure 4-609CHAPTER 4 IMAGE FORMATION SYSTEM4-31DC control PCB Secondary pre-transfer chargingbias generationcircuitSecondary pre-transfer DC biasdrive signalAC+DC (negative)Secondary pre-transfer AC biasdrive signalSecondary pre-transfercharging bias level switchsignalSecondary pre-transfercharging assemblyDC controllerPCBSecondarytransfer biasgeneration circuitSecondary transfer DC (positive)bias drive signalSecondary transfer DC (negative)bias drive signalSecondary transfer bias level (constant current) control signalSecondary transfer bias (constant voltage) control signalDC (positive)orDC (negative)Secondary transfer beltDownload free service manual at http://printer1.blogspot.com
