Blanking (Whiting) Of Non-Image Areas For Reduction; Blanking (Whiting) Out The Leading/Trailing Edges And Between Copies - Canon NP6218 Service Manual

2. Blanking (Whiting) of Non-Image Areas for Reduction

In Reduce mode, the change solenoid (SL1) turns on, and the lens moves according
to the selected reproduction ratio. When the change solenoid (SL1) turns off, the drive of
the lens motor is transmitted to gears A and B, thereby moving the slide shutter (rear,
front) for the appropriate distance to open the exposure window. In this condition, the
light from the pre-exposure lamp is directed to the photosensitive drum by way of the
reflecting plate for size blanking.

3. Blanking (Whiting) Out the Leading/Trailing Edges and between Copies

The blank shutter solenoid drive signal (BSSSLD) turns on or off under the control of
the microprocessor (Q301) on the DC controller. The leading/trailing edge and the area
between copies are blacked (whited) out by opening the open/close shutter in this way.
COPYRIGHT © 1997 CANON INC.
A
B
Figure 4-116
Size blanking optical path
Full blanking optical path
Open/close shutter
Slide shutter
Pre-exposure optical path
Drum cleaning
assembly
Drum cartridge
Pre-exposure
reflecting plate
Figure 4-117
CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 4 IMAGE FORMATION SYSTEM
Reflecting plate
for size blanking
Reflecting plate
for full blanking
Image exposure
optical path
Photosensitive
drum
4-19