3–53
OPERATIONS AND TIMING
COPYRIGHT
©
1998 CANON INC. CANON NP6621 REV.0 FEB. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
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.
The machine’s blank exposure area is controlled
by two slide shutters and one open/close shutter.
Figure 3-315
Lens motor
M3
Change solenoid (SL1)
Slide shutter (rear)
Size blanking
reflecting plate
Gear A
Gear B
Full blanking
reflecting plate
Blanking
shutter
solenoid
(SL3)
Pre-exposure lamp
Open/close shutter
Blanking shutter
home position sensor
(PS3)
Slide shutter
(front)
DC controller PCB
Blanking shutter solenoid drive signal
(BSSLD*)
Blank home position detection
signal (BSHP)
Change solenoid drive signal (CHSLD*)