Canon iR3570 Series, Service Manual

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Chapter 6
6-3
6.2 Basic Sequence
6.2.1 Basic Sequence
0006-5972
iR2270 / iR2870 / iR3570 / iR4570 / iR2230 / / / iR3530 /
When the control panel power switch is turned on, the laser scanner starts to rotate; when the motor rotation reaches its target revolution, the machine turns on the
laser unit. Thereafter, when the Start key is turned on, the machine generates the image request signal (PVREQ) on the printer side, and turns on the laser beam
with reference to the generated signal.
A4, 1 Copy
F-6-4
6.3 Various Controls
6.3.1 Controlling the Laser Activation Timing
6.3.1.1 Turning On and off the Laser Light
0006-5973
iR2270 / iR2870 / iR3570 / iR4570 / iR2230 / / / iR3530 /
The laser light is turned on and off according to the combination of laser control signals (CNT0/1/2) from the DC controller PCB.
T-6-7
CNT2 Laser driver control signal
VDO2 Image data signal input
PWCHG Light intensify switchover signal
FG PULSE DETECT FG PULSE detecting signal
POLYGON FG FG output signal
P ACC Motor acceleration signal
P DEC Motor deceleration signal
BD BD output level single
Laser control signal Laser status
CNT2 CNT1 CNT0 Laser A Laser B
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 input enabled Video signal input enabled
0 1 1 OFF OFF
0 0 1 OFF ON (for APC control)
0 1 1 OFF OFF
Single Description
PRINT STBY STBY INTR
PVREQ
BD
BD detection/APC control ON
APC control ON
Laser A
BD detention/APC control ON