Laser Exposure System; Overview; Laser On/Off Control - Canon imageRUNNER ADVANCE 715iF III Series Service Manual

Laser Exposure System

Overview

The laser exposure system forms a static latent image on the Photosensitive Drum by laser exposure.
The Laser Scanner Unit consists of the Laser Assembly and the Scanner Motor, and is controlled by the signal input from the DC
Controller PCB.

Laser ON/OFF Control

Purpose
Turns the laser beam ON and OFF according to the combination of laser control signals.
Execution timing
After turning ON the power
Control description
The DC Controller performs the register setting of the Laser Polygon Control ASIC on the Laser Driver PCB. This Laser Polygon
Control ASIC switches between four modes (Forced OFF mode, APC mode, Print mode, and Standby mode).
DC Controller
Mode
Forced OFF mode
APC mode
Print mode
Stanby mode
Scanner Mirror
Scanner Motor Assembly
APC signal
PCB
Video signal
CPU
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 machine is in standby mode
DC Controller
Laser Assembly
BD Sensor
Photosensitive Drum
Laser Driver PCB
46
Polygon Mirror
Laser
Beam
Remarks
2. Technology