Chapter 2
2-4
F-2-4
The DC controller sends the VIDEO signals (VDO1, /VDO1, VDO2, /VDO2) and the LASER CONTROL signals (CNT0, CNT1, CNT2) to the logic circuit in the
laser driver IC. The VIDEO signals are for image formation and the LASER CONTROL signals are for switching the operational
modes of the laser. The laser driver IC controls the laser according to the combination of the CNT0, CNT1, and CNT2.
The table below indicates combinations of the LASER CONTROL signals (CNT0, CNT1, CNT2).
T-2-2
This control incorporates the LASER CONTROL signals for the following 4 controls:
1) Laser emission control
2) Automatic power control (APC)
3) Horizontal synchronization control
4) Image masking control
Operation mode
CNT2
CNT1
CNT0
Remarks
Discharge mode
L
L
L
C802, C803 discharge
Data output mode
H
H
H
Used during normal printing
LD1 APC mode
L
H
L
Used during LD1 APC mode
LD2 APC mode
L
L
H
Used during LD2 APC mode
Force LD1, LD2 ON
H
L
L
Used during test printing
Force LD1, LD2 OFF
L
H
H
Used during image masking period
Video
controller PCB
Logic circuit
PD
LD1
Engine
controller PCB
Laser driver PCB
Laser driver IC
CPU
VCC
IC201
LD2
LD1
switching
circuit
/CNT0
/CNT1
/CNT2
Reference
voltage
Comparator
Sample
hold circuit
C803
C802
J801
-14
J201
-12
-6
-5
-3
-2
-16
-17
-18
-10
-9
-8
BD PCB
/BDI
-15
-11
VDO1
/VDO1
VDO2
/VDO2
GND
-14
-13
LD2
switching
circuit
/BDO
CNT0
CNT1
CNT2
Comparator
Sample
hold circuit
-13
+5V
Summary of Contents for LBP3300 Series
Page 1: ...Jan 19 2006 Service Manual LBP3300 Series LBP3300 ...
Page 9: ...Chapter 1 PRODUCT DESCRIPTION ...
Page 16: ...Chapter 2 TECHNICAL REFERENCE ...
Page 43: ...Chapter 3 DISASSEMBLY AND ASSEMBLY ...
Page 56: ...Chapter 4 MAINTENANCE AND INSPECTION ...
Page 59: ...Chapter 5 TROUBLESHOOTING ...
Page 63: ...Chapter 6 APPENDIX ...
Page 68: ...Sep 19 2006 PARTS CATALOG LBP3300 LBP3360 ...
Page 97: ......