Bd Signal Generation; Overview; Bd Generation / Detection; Ii. Bd Signal Generation - Canon GP160DF Service Manual

II. BD SIGNAL GENERATION

A.

Overview

When the laser is illuminated onto the photosensitive drum, a laser emission start
signal (horizontal sync. signal) is necessary. The laser beam sensor signal is used to
generate this start signal.
B.

BD generation / detection

The DC controller PCB CPU outputs the laser forced light signal (LON*) at "0",
based on the BDI* signal, and forcibly emits the laser. The laser beam is reflected by the
BD mirror and then input in the BD sensor PCB. BD sensor PCB detects this laser beam
and generates a BD input signal (BDI*), then sends it to the DC controller PCB CPU
(IC301). The CPU (IC301) generates a horizontal sync. signal (BDO*) based on the
BDI* signal, and outputs it to the image processor PCB.
Photosensitive drum
BD sensor PCB
COPYRIGHT © 1999 CANON INC.
Back
Collimator lens
Polygon mirror
(6 sided)
DC controller PCB
CANON GP160 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 5 LASER EXPOSURE SYSTEM
Laser forced light emission signal (LON*)
Horizontal sync.
signal (BDO)
Figure 5-201
Front
BD mirror
Laser
Laser scanner unit
Image processor
PCB
5-3