H. Controlling the Primary Corona Roller Cleaning Mechanism1. OutlineThe copier’s primary charging roller is equipped with an automatic cleaningmechanism.The automatic cleaning mechanism cleans the primary charging roller during initialrotation(INTR) after having made 250 or more copies, i.e., after executing transfer rollerrelease control five times.2. Primary Charging Roller Cleaning OperationThe primary charging roller cleaning solenoid (SL4) on signal (PCLSLD) is generatedunder the control of the microprocessor (Q301) on the DC controller PCB. In responseto the signal, the cleaning pad is butted against the roller for 2 sec, during which time thecleaning roller makes about 4 rotations.Figure 4-118COPYRIGHT © 1997 CANON INC. CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 4 IMAGE FORMATION SYSTEM4-20Primary charging rollercleaning solenoid Fulcrum Fulcrum Cleaning padPrimarychargingrollerDrum unit Drum
