Service manual

COPYRIGHT © 1999 CANON INC. CANON GP160 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 5 LASER EXPOSURE SYSTEM
5-6
IV.LASER SCANNER MOTOR CONTROL
A. Operation outline
The laser scanner motor is a 3 phase 8 pole DC brushless motor integrated, with the
laser scanner motor drive circuit.
The laser scanner motor rotates when receiving the instruction from the DC con-
troller PCB. The supply of electrical power to the motor is controlled inside the scanner
driver PCB.
When the scanner motor acceleration signal (ACC*) is output from the DC controller
PCB, electrical power is supplied from the scanner driver PCB motor drive circuit, and
the laser scanner motor rotation is maintained.
When the laser scanner motor is rotating by the CPU forcing the laser to emit light, a
BDI* signal is sent from the BD sensor PCB to the DC controller PCB. The DC controller
PCB’s CPU detects the BDI* signal cycle, and the ACC* signal controls the laser scan-
ner motor rotation until it reaches the stipulated rotation count.
Furthermore, when stopping the laser scanner motor, the CPU changes the scanner
motor deceleration signal (DEC*) to “0”, and stops the motor’s rotation.
Figure 5-401
BD sensor PCB
Motor drive circuit
Laser scanner motor
driver PCB
Laser
scanner
motor
6 sided mirror
Laser scanner motor
DC controller PCB
BD input signal (BDI*)
24VA
Scanner motor acceleration
signal (ACC*)
Scanner motor deceleration
signal (DEC*)
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