Canon NP6012 Service Manual page 61

TEEUOP ERATIONS AND 1198025. ST
4. Driving the Scanner/Lens Drive Motor
a. Outline
The scanner/iens drive motor (M2) is a
4-phase stepping motor. It is turned on or off
and its direction and speed of rotation is
changed by controlling the output timing of
the drive power supply SC-COMA and SC-
COMB and pulse signals A, A", B, and B*.
b. Operation
The microprocessor (Q101) on the DC
controller PCB receives such instructions as
copying modes and reproduction ratios from
the control panel circuit; and, in response, it
sends drive pulses to the scanner motor
(M2) through the motor drive circuit.
Voltage
on/off
signal Motor drive
= voltage on/off
24V |
The scanner/lens drive motor is a 4-
phase stepping motor, and controls the
direction and speed of scanning by changing
the frequency and the sequence of drive
pulses (SC-A through SC-B*).
The motor drive voltage on/off switching
circuit supplies power to drive the motor and
removes power to stop it. The current
switching circuit sets the current flowing to
the motor according to the speed of rotation;
the motor driver circuit is used to control the
rated current according to the setting.
J110
SC-COMA H 4
switching circuit
Microprocessor
Current
switching}
circuit
signal Current switching
SC-COMB | -1
(Q109)
i
i
!
i
1
i
i
—4
{
|
|
!
SC-A |-6
SC-A*| -5
_ —*
Motor | ¢¢.8 1-3
driver —_+—
circuit j
Figure 3-206
3-16 COPYRIGHT © 1995 CANONINC.
CANON NPGO12/NPSOT2F/NP6212 REV.1 SEPT, 1996 PRINTED IN JAPAN (MPRIME AU JAPON)