The laser driver PCB is divided into two. One is for Y/M, and the other for C/K. The Y/M laser
driver PCB only is described here, as both are identical.
Figure 5-21.
Laser control block diagram
The DC controller sends the VIDEO signals (VDO, /VDO) for forming images and the
LASER CONTROL signals (CTRL0, CTRL1) for switching the operation modes of the laser
driver circuit to each laser driver IC (IC101, IC102). The laser driver IC controls the laser
according to the combination of the LASER CONTROL signals.
The following table shows the combination of the LASER CONTROL signals for yellow.
Operation mode CTRL0 CTRL1 Description
Standby L L Laser control OFF
Print H L Ready to emit laser by VIDEO signals
Force LD ON L H Force the laser ON
Force LD OFF H H Force the laser OFF
The LASER CONTROL signal is used for the following controls:
● Laser emission control
● Automatic photocurrent control
ENWW Laser/scanner system 141
