Canon imageRUNNER 2520 Series, Service Manual, Page: 59 / 402

*1: The BD signal is generated in reference to the light from laser C. The BD sensor of the BD PCB
receives light from laser C but not light from laser D.
PRINT STBY STBY INTR
PVREQ
BD
BD detection/APC control ON
APC control ON
Laser C
BD detention/APC control ON
Laser C
Laser D
Controls
■ Controlling the Laser Activation Timing
● Laser ON/OFF Control
Laser ON/OFF control is dependent on the combination of the laser control signal (CNT1-0/1-1/1-2) from the image PCB.
Laser control signal Laser status
CNT1-2 CNT1-1 CNT1-0 C Laser D 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
J8142
C
T
RL
0
_2
C
T
RL
0
_1
C
T
RL
0
_0
Main Controller PCB
● Main Scanning Synchronous Control
The synchronous control in the main scanning direction is performed in the synch circuit based on the BD synchsignal.
Using the BD signal generated based on the light from laser C, the DC controller PCB generates the BD synchsignal for laser C
and the BD synch signal for laser D.
2. Technical Explanation
49