Canon LBP6000 Series, Руководство по обслуживанию

Страница: 38 / 146

Chapter 2
2-6
*: Unblanking period
The period during which the laser diode is emitted in non-image area.
2.3.2.3 Laser ON/OFF Control
0025-1141
LBP6000 / LBP6000B
In this control, the laser driver turns on/off the laser diode (LD) according to the laser control signal sent from the engine controller.
The following is the circuit diagram of the laser control.
F-2-6
The engine controller sends the laser control signal (CNT0, CNT1) for changing the operation mode of the laser to the logic circuit in the laser driver IC, as well as
the video signal (VD0, /VD0) for image formation. The laser driver IC executes laser control according to the combination of the CNT0, CNT1 signals.
The following is the combination of the laser control signal (CNT0, CNT1).
T-2-4
2.3.2.4 Horizontal Sync Control
0025-1142
LBP6000 / LBP6000B
This is the control to adjust the writing position in the image horizontal direction.
Operation mode CNT0 CNT1 Remarks
Discharge L L The capacitor (C1) is discharged.
Data output H H At normal print
APC H L At using APC
Forced OFF L H At using image mask
Engine controller
Main controller
Laser driver PCB
Laser driver IC
BD Sensor
LD PD
C1
+3.3V
/BDI
+5V
CNT1
CNT0
VOD
/VOD
Sample hold
circuit
Drive
circuit
Comparator
Logic PCB
/BD