Laser Exposure System; Original Exposure System; Laser Processing Assembly - Canon GP215 Service Manual

IV. LASER EXPOSURE SYSTEM
A. Laser Processing Assembly
1. Outline
The major components of the laser unit include a laser unit, which serves as the source of laser beams,
a laser scanner motor, which is equipped with a 6-facet mirror, and a BD detection PCB, which serves to
detect laser beams.
The laser beam generated by the laser unit is directed to the 6-facet mirror rotating at a specific speed.
The laser beam reflected by the 6-facet mirror is moved through the imaging lens and its optical path is
bent by the laser mirror before it reaches the photosensitive drum. While all this is taking place, the laser
beam is bent to an acute angle by the BD mirror located inside the laser scanner unit for the BD detection
PCB. (Figure 3-401B)
When the 6-facet mirror rotates at a specific speed, the laser beam scans the surface of the photo-
sensitive drum at a specific speed to remove charges and, as a result, to form a latent image.

Original exposure system

No. 2 mirror
No. 3 mirror
CORE/IP Baord
Printer FAX
Board Board
COPYRIGHT © 1996 CANON INC.
Scanning lamp
No. 1mirror
Image processing system
Image processor
PCB
Laser
Laser
Driver

Laser exposure system

Figure 3-401A
CANON GP215/200 REV.0 JULY 1996 PRINTED IN JAPAN (IMPRIME AU JAPON)
3. OPERATIONS AND TIMING
CCD
Lens
Analog
processor
PCB
Laser beam
Laser
mirror
Photo-
sensitive
drum
3–51