Canon 1000 Service Manual page 126

3. OPERATION AND TIMING
5. Correcting a Discrepancy in the
Main Scanning Direction
If the coordinates of the centers at the front
and the rear are different (in Figure 3-434, ∆Y is
not 0), the position where images are started in the
main scanning direction is likely to have a
discrepancy. Correction is made so that ∆Y will be
closer to 0. (In the case of Figure 3-434, the start of
Y will be delayed to correspond to the start of M.)
The correction is made by changing the read timing (T1 in Figure 3-435) for the Y, C, and Bk video
signals. In the case of Figure 3-434, T1 is extended, thereby delaying the start of the Y image.
Y BD signal (YBD)
Y main scanning direction sync signal (YSYNC*)
Y read enable signal (YRE*)
Y video signal (YVD)
Video controller PCB
BD signal
BD detection
PCB
Y,M,C,Bk
3-82
COPYRIGHT © 2001 CANON INC.
Clock
generation
for
sync control
Feeding direction
Figure 3-435
C,Bk
WE
YRE, MRE
WE
Memory for main
scanning sync (FIFO)
Y,M
The read timing is varied at points
indicated by broad arrows.
Figure 3-436
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
Y
Y
Y
Figure 3-434
T1
Effective pixels on CCD
Video signal
Memory for main
scanning sync (FIFO)
C,Bk
CRE, BkRE
Video signal
Y,M
M