Canon 1000 Service Manual page 123

The pattern reading assembly is equipped with a shutter (Figure 3-428) to prevent soiling with toner. The
shutter is driven by the shutter drive motor, and the open/closed positions detected by the shutter open/
closed sensor.
See Figure 3-429 for the sequence of operations. In sync with the image position correction movement,
the shutter drive motor remains on for 5 sec to move the shutter to the open position. After reading eight sets
of patterns, the shutter drive motor remains on for 5 sec once again to move the shutter to the closed position.
Shutter drive motor (M25)
Shutter closed sensor
(PS39)
Shutter open sensor
(PS40)
Y image print enable signal
(YPE)
M image print enable signal
(MPE)
C image print enable signal
(CPE)
Bk image print enable signal
(BkPE)
Pattern read signal
(CCDRD)
If the shutter open sensor dose not detect the light-blocking plate when the shutter must open while the
motor is at rest, 'E194-0001' will be indicated on the control panel. If the shutter close sensor does not detect
the light-blocking plate when the shutter must close, 'E194-0002' will be indicated on the control panel.
COPYRIGHT © 2001 CANON INC.
Shutter open sensor
(PS40)
Shutter drive motor
(M25)
Figure 3-428
Y M C Bk
1st set
Figure 3-429
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
3. OPERATION AND TIMING
Shutter closed sensor
(PS39)
Shutter
Y M C Bk
8th set
3-79