Canon 1000 Service Manual page 112

3. OPERATION AND TIMING
2. Synchronization Control for the Main/Sub Scanning Direction
The video signals are synchronized for the main scanning direction based on the BD signal by the video
controller. The video signal after gamma correction is written to the memory for main scanning direction
synchronization in response to the main scanning sync signal (HSYNC*) based on the write BD signal
(WBD). At this time, writing is enabled by the write enable signal (WE*), and the same timing is used for Y, M,
C, and Bk.
Reading from the memory for the main scanning direction is executed based on the BD signal for Y, M,
C, and Bk. In the sample shown in Figure 3-410, the Y main scanning sync signal (YSYNC*) is generated in
sync with the Y BD signal (YBD); the read enable signal (YRE*) is generated after a specific period of time*
following the generation of YSYNC; and the Y video signals are read from the memory for the main scanning
direction.
*May be changed; used for image position correction explained later.
Video control PCB
BD signal
BD
detection
Y,M,C,Bk
PCB
Write BD signal (WBD)
Main scanning sync signal
(HSYNC*)
Write enable signal (WE*)
Y video signal (YVD)
Y BD signal (YBD)
Y main scanning sync signal
(YSYNC*)
Y read enable signal (YRE*)
Y video signal (YVD)
3-68
COPYRIGHT © 2001 CANON INC.
WE
Clock
generation
for
sync
control
WE
Y,M
Figure3-409
Figure 3-410
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
C,Bk
Memory for
main scanning
direction sync
CRE, BkRE
YRE, MRE
Memory for main
scanning direction
Effective pixels in CCD
Video signal
C,Bk
Video signal
Y,M