Laser Driver - Canon 1000 Service Manual

3. OPERATION AND TIMING
F. Laser Driver
Figure 3-417 shows the laser driver PCB used to generate the laser drive signal from video signals. The
circuit drives the semiconductor laser units, and the laser power adjustment PCB monitors and controls the
intensity of the laser beam. Each of these PCBs has the following functions:
Laser Driver PCB
1 Generates the laser drive signals for 400 lines/200 lines/266 lines.
2 Turns ON/OFF the laser.
3 Selects activation mode.
Laser Power Adjustment PCB
1 Monitors laser intensity.
2 Generates activation current.
3 Detects errors in activation current.
Laser driver PCB
Video signal
8
Mode signal
Error signal
3-72
COPYRIGHT © 2001 CANON INC.
Signal generation for 400 lines
Signal generation for 200 lines/
266 lines
Laser power adjustment PCB
Activation current generation
Figure 3-417
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
Laser drive signal
Intensity monitor
Laser power setting
Laser beam
+5V