3–53OPERATIONS AND TIMINGCOPYRIGHT © 1998 CANON INC. CANON NP6621 REV.0 FEB. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)J. Blank Exposure Control1. OutlineThe machine directs light from the pre-exposurelamp to the photosensitive drum by way of a reflectingplate for blank exposure, thereby blanking out gapsbetween sheets of paper and non-image areas.The machine’s blank exposure area is controlledby two slide shutters and one open/close shutter.Figure 3-315Lens motor M3Change solenoid (SL1)Slide shutter (rear)Size blankingreflecting plateGear AGear BFull blankingreflecting plateBlankingshuttersolenoid(SL3)Pre-exposure lampOpen/close shutterBlanking shutterhome position sensor(PS3)Slide shutter(front)DC controller PCBBlanking shutter solenoid drive signal(BSSLD*)Blank home position detectionsignal (BSHP)Change solenoid drive signal (CHSLD*)
