CHAPTER 4 IMAGE FORMATION SYSTEM

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.

A

B

Figure 4-116

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.

Size blanking optical path

 

Reflecting plate

 

for size blanking

Full blanking optical path

Reflecting plate

for full blanking

 

Open/close shutter

Slide shutter

Image exposure optical path

Pre-exposure optical path

Drum cleaning

Drum cartridge assembly

Pre-exposure

reflecting platePhotosensitive drum

Figure 4-117

COPYRIGHT © 1997 CANON INC.

CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)

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Canon FY8-13EX-000, NP6218 service manual Blanking Whiting of Non-Image Areas for Reduction