Sub Scan Sync Control - Canon imagePRESS C1 P Service Manual

[1] FIFO
[2] BD PCB
[3] Laser Unit
MN-CON: Main controller PCB
DC-CON: DC controller PCB

6.3.1.3 Sub Scan Sync Control

imagePRESS C1 P / imagePRESS C1 / imagePRESS C1+ (Printer) / imagePRESS C1+
The sync control of the sub scanning is the control for adjustment of the writing position of each color image formed on ITB at full-color print.
This control is performed at the sub scan sync control circuit in ASIC.
This circuit produces the sync signal (PVREQ) of the sub scanning based on ITB home position signal (ITBHP) detected by ITB home position sensor.
Here the operation of this circuit is explained.
ITB home position signal (ITBHP) output from the ITB home position sensor is detected at the sub scanning sync control circuit.
At the same time, this circuit produces PVREQ signal for each color based on ITBHP signal, output them to the main controller PCB.
The main controller PCB sends VIDEO signal to DC controller PCB synchronized with PVREQ signal for each color.
After that, DC controller PCB produces the image for each color at the specified position on ITB.
[1] Sub Scanning Sync Control Circuit
[2] ITB Home Position Sensor
MN-CON: Main Controller PCB
DC-CON: DC Controller PCB
[2]
J1120
J1122
LD
PWM IC
(IC28)
WCK
LSYNC
PWM IC
WCK
(IC29)
ASIC(IC262)
DC-CON
ITB
ITBHP
[2]
[3]
PBD
VDO
[1]
F-6-5
DC-CON
[1]
ASIC(IC262)
F-6-6
MN-CON
PVREQ
MN-CON
VDO
Chapter 6
0012-7579
6-5