Outline; Laser Exposure System - Canon 1000 Service Manual

3. OPERATION AND TIMING
IV. LASER EXPOSURE SYSTEM
A. Outline
The laser exposure system consists of a laser unit, which is the source of laser beams, a laser scanning
unit, which performs laser scanning (main scanning direction) using a polygon (8-facet) mirror, and a BD
detection PCB, which generates sync signals for scanning direction.
DC controller PCB
Motor driver PCB
BD detection PCB
The video signals (for M in Figure 3-401), which is synchronized for main and sub scanning directions by
the video controller, are converted by the laser driver into laser drive signals that represent the level of the
signals. The laser beam is generated by the laser unit using this laser drive signal. The laser beam comes to
have scanning characteristics in a specific direction because of the polygon mirror, which rotates at a high
speed. The laser beam hits and scans the negatively charged photosensitive drum (Figure 3-401) to form a
static latent image on the photosensitive drum.
3-62
COPYRIGHT © 2001 CANON INC.
Polygon mirror
BD signal
Figure 3-401
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
Laser unit for M
Laser driver PCB
Video controller PCB