Scanner Drive System; Document Scanner Motor - Canon GP160DF Service Manual

II. SCANNER DRIVE SYSTEM
A.

Document scanner motor

The document scanner motor (M701) uses a 2 phase excitation stepping motor
which is controlled by the image processor PCB.
The image processor's PCB drive control IC (IC15) sends instructions for the clock-
wise rotation (scanner forward movement), anti-clockwise rotation (scanner backward
movement) and the rotation speed to the motor driver IC (IC3). The motor driver IC (IC3)
supplies power to the document scanner in compliance with the clock signal which is
sent with this control instruction.
Reference:
In the event of a failure such as a blown fuse in the document scanner motor, 24 V
continues to be supplied to the motor driver's IC (IC3) which causes the IC's surface
temperature to increase. Consequently, a thermoswitch has been installed in the
motor driver IC (IC3) for its protection. When the IC surface temperature reaches 115
± 5°C the thermoswitch's contact is released, cutting off the 24V power supply to the
motor driver IC (IC3).
If it is not possible to replace this thermoswitch, or if the switch has tripped because
the temperature does not return to normal, eliminate the cause of the temperature
increase, and then replace the image processor PCB.
Drive
control IC
(IC15)
Related service mode
By setting service mode>#10 CS SET>, the Mirror 1 mount will be moved to the fac-
tory setting position.
COPYRIGHT © 1999 CANON INC.
Image processor PCB
Thermo
switch
Motor
driver IC
(IC3)
Clock pulse
Figure 3-201
CANON GP160 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 3 EXPOSURE SYSTEM
+24V

Document scanner motor

A
COM
M701
A*
B
COM
B*
3-3