Canon imageRUNNER 2535, Service Manual, Page: 57 / 362

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Technology > Laser Exposure System > Various Controls > Controlling the Laser Activation Timing
Technology > Laser Exposure System > Various Controls > Controlling the Laser Activation Timing
Various Controls
■ Controlling the Laser Activation Timing
● Laser ON/OFF Control
Laser ON/OFF control is dependent on the combination of the laser control signal (A/B laser:
CNT1-0/1-1/1-2, C/D laser: CNT0-0/0-1/0-2) from the image PCB.
<A laser/B laser>
Laser control signal Laser status
CNT1-2 CNT1-1 CNT1-0 A Laser B Laser
0 1 0 ON (For APC control) OFF
0 1 1 OFF OFF
0 0 1 OFF ON (For APC control)
0 1 1 OFF OFF
1 1 1 Video signal entry arrowed Video signal entry arrowed
0 1 1 OFF OFF
0 0 1 OFF ON (For APC control)
0 1 1 OFF OFF
<C laser/D laser>
Laser control signal Laser status
CNT1-2 CNT1-1 CNT1-0 C Laser D Laser
0 0 1 ON (For APC control) OFF
0 1 1 OFF OFF
0 1 0 OFF ON (For APC control)
0 1 1 OFF OFF
1 1 1 Video signal entry arrowed Video signal entry arrowed
0 1 1 OFF OFF
0 0 1 OFF ON (For APC control)
0 1 0 OFF OFF
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J8142
CTRL_1-2 CTRL_1-1 CTRL_1-0 CTRL_0-2 CTRL_0-1 CTRL_0-0
Main Controller PCB
● Main Scanning Synchronous Control
Main scanning synchronous control is operated at synchronous PCB based on BD
synchronous signal.
Based on BD signal that is formed from A laser light detected by BD PCB, BD synchronous
signal for each laser is formed inside image PCB.
Image data written in the line memory is read out by the readable signal (RE_A, RE_B, RE_
C, RE_D) according to the 4 phase differences formed inside the delayPCB based on the BD
synchronous signal (BD_SYNCH) and is sent to the laser driver.
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