COPYRIGHT © 1999 CANON INC. CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)1. Primary Charging Bias Generation CircuitThis circuit is controlled by three signals (Figure 4-604) from the DC controller PCB,and generates primary charging DC bias and primary charging AC bias for application tothe primary charging roller.The primary charging AC bias is used to turn on and off the AC bias applied to theprimary charging roller, while the primary charging DC bias drive signal is used to turnon and off the DC bias applied to the primary charging roller.The primary charging bias level control signal is used to switch the levels of the pri-mary charging DC bias for image areas.Figure 4-604Note:The primary charging DC bias level for image areas is varied in conjunction with thedeveloping DC bias of each color according to the density adjustment command fromthe printer board*1 or based on the result of image density correction control (p. 4-21).*1 Reader controller PCB (when making prints with the reader unit installed).CHAPTER 4 IMAGE FORMATION SYSTEM4-27DC controllerPCB Primarycharging biasgenerationcircuitPrimary charging DC bias drive signalPrimary charging AC bias drive signalPrimary charging bias level control signalPrimary charging rollerAC+DC (negative)Download free service manual at http://printer1.blogspot.com
