Controlling The Locking Cam Inside The Transfer Drum - Canon CLC 1120 Service Manual

CHAPTER 7 PICK-UP / FEEDING SYSTEM
B. Controlling the Locking Cam Inside the Transfer Drum
The transfer drum houses the attraction brush, transfer blade, and an internal brush for
cleaning. Each brush or blade is away from the transfer drum sheet, and is brought against the
transfer drum sheet by its respective locking cam when the attraction/transfer locking cam motor
(PM7) turns on as needed. (See Figure 7-502.)
The copier's attraction/transfer locking cam motor is a stepping motor, and the locking
mechanism of each brush and blade is operated by controlling the rotation of the three locking cams
through application of specific pulses to the motor after the DC-CPU identifies home position with
reference to the signal from the attraction/transfer locking cam HP sensor (PS8).
Figure 7-503 shows the state of each brush and the blade, varying according to the position of
the locking cam.
Attraction/transfer
locking cam HP sensor
Internal brushes
7-36
COPYRIGHT © 1999 CANON INC.
Transfer blade
Internal brush
locking cam
Attraction brush
Figure 7-502
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
(rear)
Transfer blade
Attraction brush
locking cam
locking cam