Canon iR3570 Series, Service Manual

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Chapter 6
6-4
F-6-5
6.3.1.2 Main Scanning Synchronous Control
0006-5974
iR2270 / iR2870 / iR3570 / iR4570 / iR2230 / / / iR3530 /
The synchronous control in the main scanning direction is performed in the synch circuit based on the BD synch signal.
Using the BD signal generated based on the light from laser A, the DC controller PCB generates the BD synch signal for laser A and the BD synch signal for laser B.
The image data written to line memory is read out by the readout enable signal (RE_A, RE_B) generated based on the BD synch signal (BD_A, BD_B) for output
to the laser driver PCB.
F-6-6
[1] Sync circuit
[2] Delay circuit
[3] Line memory
[4] VDO
[5] VDO signal processing block
[6] Laser driver PCB
BD_A/B : BD synch signal
RE_A/B : readout enable signal
Memo:
J318
DC-CON
CNT0 CNT1 CNT2
J318 J316
J301
MN-CON
[3]
[3]
[2]
DC-CON
BD_A
RE_A
BD_B
BD
[1]
RE_B
[6]
[5]
[4]