Horizontal Scanning Synchronization Control - Canon imageRUNNER ADVANCE C255 Series Service Manual

Main Controller
PCB (UN81)
Mode
Forced OFF mode
APC mode
Print mode
Standby mode

Horizontal Scanning Synchronization Control

Purpose
Aligns the write start position in the horizontal scanning direction.
Execution timing
When printing is started (for each line)
Control description
1. The Main Controller PCB forcibly activates the laser diode of the Y/M/C/Bk Laser Driver PCB by executing the Bk laser control
signal in APC mode.
2. The laser beam of the Bk laser has a BD circuit in the scanning light path, and is incident on the BD Circuit.
3. The BD Circuit detects the laser beam and then generates a BD signal, and sends it to the DC Controller PCB.
4. The DC Controller PCB performs synchronization based on this signal, and then sends a reference BD signal to the Main
Controller PCB as the horizontal scanning synchronous signal (BD) for every line.
Laser ON
/OFF signal
ASIC
APC signal
Video signal
Laser status
OFF Clears the light intensity setting determined by the APC.
ON Adjusts laser light intensity.
On/Off Emits the laser according to the video signal.
OFF The laser is OFF in an area without images.
DC Controller
PCB (UN04)
CPU
Y/M/C/Bk
Laser
Laser Driver PCB
Beam
(UN05)
Remarks
46
2. Technology
Polygon Mirror