Canon CLC 1130, Service Manual

Page: 68 / 965

COPYRIGHT © 2002 CANON INC. CANON CLC1100/1130/1150/1160/1180 REV.1 FEB. 2002 PRINTED IN JAPAN (IMPRIME AU JAPON)
2-13
CHAPTER 2 BASIC OPERATION
a. Turning On/Off the Drum Motor
When the DC-CPU on the CPU PCB causes the drum motor drive signal (DRMON) to go ‘1’
through the DC driver PCB, the control circuit on the drum motor drive PCB generates drive
current to rotate the drum motor at a constant speed.
When the drive signal goes ‘0’, on the other hand, the output of the control signal stops, and the
absence of drive current prevents the drum motor from rotating.
b. Controlling the Rotation Speed
The drum motor operates in sync with the drum motor clock signal (DRMCLK) generated
from the BD signal so that color displacement otherwise occurring when images are printed may be
corrected.
To ensure proper fixing when copying on transparencies or thick paper, the rotation speed is
reduced to suit the speed of the fixing motor.
The foregoing speeds are controlled by two speed control signals (DRMSP0, DRMSP1) from
the DC driver PCB.
The rotation speed control circuit compares the pulse signals and reference signals (clock
signals), and exerts control so that the phase of one matches that of the other. At this time, it sends
a signal indicating a state of constant speed (DRMRDY=1) to the DC driver PCB.
It also generates the drum motor FG signal (DRMFG) in keeping with the rotation cycle of the
drum motor for counting purposes (drum rotation) and sequential control.
E012
If an error causes the rotation speed of the motor to deviate, the drum motor
ready signal (DRMRDY) indicating a state of constant speed will go ‘0’,
stopping all operations of the copier (drum motor error).
DRMSPO DRMSP1
Normal 0 0
Transparency 0 1
Service mode* 1 1
· When checking parts in service mode (FUNCTION>PART-CHK>MTR>6).