Canon 1000S, Руководство по обслуживанию

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COPYRIGHT © 2001 CANON INC. CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
3-69
3. OPERATION AND TIMING
The video signals are synchronized for the sub scanning direction by the video controller based on the
image leading edge signal (ITOP). The ITOP signal is triggered by the output of the transfer belt home
position sensor, and the timing of output varies according to paper size. When the ITOP signal is generated,
the read enable signal for each color (YMRE in the case of Figure 3-411) causes the video signals (YMCBk)
to be read from the page memory area for transmission to the video controller. (As can be learned from the
timing chart, the read enable signal for each color is given a delay for the distance between drums.)
The video signal is forced to remain ‘0’ until the print area signal (YFRM in Figure 3-411) is generated,
thereby creating a leading edge margin.
Figure 3-411
Figure 3-412
Sub scanning
sync control
Density correction
Y,M,C,Bk
Video controller PCB
ITOP signal
Print area signal
Memory read
signal (MRE)
Test pattern
Video signal
Y,M,C,Bk
Video signal
Y,M,C,Bk
Video signal
Memory PCB
DC controller PCB
Image processor PCB
Image leading edge signal
(ITOP)
Y read enable signal (YMRE)
M read enable signal (MMRE)
Y print enable signal (YPE)
M print enable signal (MPE)
Y print area signal (YFRM)
M print area signal (MFRM)
Paper length
(feeding direction)
Paper length
(feeding direction)
Image area
Image area
Drum distance
1st page 2nd page
1st page