Outline; Optical Unit Failure Detection - Canon LBP6670dn Series Service Manual

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Technology > Laser Exposure System > Optical Unit Failure Detection
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.
Engine controller
DC controller
Scanner mirror
Scanner motor unit
2 Technology > Laser Exposure System > Optical Unit Failure Detection
Main controller
Laser unit
BD sensor
Photosensitive drum
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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.
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