Laser Exposure System; Outline; Optical Unit Failure Detection - Canon LBP253 SM Manual

Laser Exposure System

Outline

The laser exposure system forms a latent image on the photosensitive drum according to the VIDEO signalssent from the Main
Controller.
The main components of the laser scanner are the laser unit and the scanner motor unit, which arecontrolled by the signals sent
from the DC controller.
Diagram of the Laser Scanner Unit is shown below.

Optical Unit Failure Detection

The optical unit failure detection manages the laser scanner failure detection functions.
The DC controller determines an optical unit failure and notifies E100 to the Main controller if the laser scanner encounters the
following conditions:
• If the scanner motor does not reach a specified rotation within a specified period of start-up.
• If the rotation of the scanner motor is out of specified range for a specified period during drive.
• If an out of specified BD interval is detected during a print operation.
Engine controller
DC controller
Scanner mirror
Scanner motor unit
16
Main controller
Laser unit
BD sensor
Photosensitive drum
2. Technology