Canon GP215, Руководство по обслуживанию

Страница: 105 / 458

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.
3–51
COPYRIGHT © 1996 CANON INC. CANON GP215/200 REV.0 JULY 1996 PRINTED IN JAPAN (IMPRIME AU JAPON)
3. OPERATIONS AND TIMING
Figure 3-401A
Original exposure system
No. 2 mirror
No. 3 mirror
No. 1mirror
Scanning lamp
Lens
CORE/IP Baord
Printer
Board
FAX
Board
Image processing system
Image processor
PCB
Laser
Driver
Laser
Laser exposure system
Laser beam
CCD
Analog
processor
PCB
Laser
mirror
Photo-
sensitive
drum