Basic Sequence; Various Controls; Controlling The Laser Activation Timing; Turning On And Off The Laser Light - Canon iR3570 Service Manual

6.2 Basic Sequence

6.2.1 Basic Sequence
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

6.3 Various Controls

6.3.1 Controlling the Laser Activation Timing

6.3.1.1 Turning On and off the Laser Light

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.
Single
CNT2
VDO2
PWCHG
FG PULSE DETECT
POLYGON FG
P ACC
P DEC
BD
STBY INTR
PVREQ
Laser A
BD detention/APC control ON
Laser control signal
CNT2 CNT1 CNT0
0 1 0
0 1 1
0 0 1
0 1 1
1 1 1
0 1 1
0 0 1
0 1 1
Description
Laser driver control signal
Image data signal input
Light intensify switchover signal
FG PULSE detecting signal
FG output signal
Motor acceleration signal
Motor deceleration signal
BD output level single
PRINT STBY
BD
BD detection/APC control ON
APC control ON
F-6-4
T-6-7
Laser status
Laser A Laser B
ON (for APC control) OFF
OFF OFF
OFF ON (for APC control)
OFF OFF
Video signal input enabled Video signal input enabled
OFF OFF
OFF ON (for APC control)
OFF OFF
Chapter 6
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