Laser Exposure System; Outline - Canon imageCLASS D600s Service Manual

CHAPTER 4 OPERATION

3 Laser Exposure System

3.1

Outline

The laser scanner unit consists of the following major components:
• laser unit, which serves as the source of laser light.
• laser scanner motor, equipped with a 4-face mirror for laser scanning.
• laser driver/BD PCB used to detect laser light or to control emission of laser light.
The laser beam generated by the laser unit based on the signals from the DC controller
PCB moves through the collimator lens (inside the laser unit) and the cylindrical lens to
reach a 4-face polygon mirror rotating at a constant speed.
When reflected by the 4-face polygon mirror, the laser beam moves through the imaging
lens, and is bent by the bending mirror to reach the photosensitive drum. At this time, the
laser light also is directed to the BD circuit of the laser driver/BD PCB. (F04-301-01)
As the 4-face polygon mirror rotates at a constant speed, the laser light scans the surface
of the photosensitive drum at a constant speed, thereby removing charges and forming static
images.
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COPYRIGHT © 2001 CANON INC.
Chapter4.p65
CANON imageCLASS D600s/PC1060s/PC1200s/iR1200s REV. 0 SEPT. 2001
14 8/26/01, 3:44 PM