Blank Exposure Control - Canon NP6621 Service Manual

J. Blank Exposure Control
1. Outline
The machine directs light from the pre-exposure
lamp to the photosensitive drum by way of a reflecting
plate for blank exposure, thereby blanking out gaps
between sheets of paper and non-image areas.
Lens motor
Gear A
Gear B
Blanking
shutter
solenoid
(SL3)
COPYRIGHT © 1998 CANON INC.
M3
Slide shutter (rear)
Pre-exposure lamp
Open/close shutter
DC controller PCB
CANON NP6621 REV.0 FEB. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
The machine's blank exposure area is controlled
by two slide shutters and one open/close shutter.
Change solenoid (SL1)
Size blanking
reflecting plate
Blanking shutter
home position sensor
(PS3)
Figure 3-315
OPERATIONS AND TIMING
Full blanking
reflecting plate
Slide shutter
(front)
3–53