Canon NP6218, FY8-13EX-000 service manual Controlling Blank Exposure, Bssld

CHAPTER 4 IMAGE FORMATION SYSTEM

G. Controlling Blank Exposure

1. Outline

The copier uses the reflecting plate to direct the light of the pre-exposure lamp to the photosensitive drum by way of executing blank exposure, thereby blanking (whiting) out the non-image areas and areas between copies.

The area of blank exposure is controlled by the two slide shutters and one open/close shutter.

Lens motor M

Change solenoid (SL1)

Gear A

Gear B

Blank shutter solenoid (SL3)

drive signal	(BSSLD*)
Blank shutter solenoid

Slide shutter (rear)

Reflectiong plate for size blanking

Pre-exposure lamp

Blanking shutter home position sensor (PS3)

Open/close shutter

Reflectiong plate for full blanking

Slide shutter (front)

Blank shutter home position detection signal (BSHP)

Change solenoid drive signal (CHSLD*)

DC controller PCB

Figure 4-115

4-18 COPYRIGHT © 1997 CANON INC. CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)