Controlling The Intensity Of Laser Light; Apc Control - Canon iR4570 Series Service Manual

J318
[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:
The BD sensor of the BD PCB receives light from laser A only, and is free of light from laser B, i.e., the BD signal
is generated based on the light from laser A.

6.3.2 Controlling the Intensity of Laser Light

6.3.2.1 APC Control

iR2270 / iR2870 / iR3570 / iR4570
The laser light hitting the photodiode included in the laserdiode is monitored and is controlled so that it remains a
[6]
BD_A
[1]
RE_A
BD_B
[2]
RE_B
[5]
DC-CON
J316
[3]
[3]
F-6-6
MN-CON
[4]
Chapter 6
0006-5976
6-9