Developing Assembly/Drum Claener; Outlines; Remaining Toner Sensor; Torque Limiter - Canon NP6320 Service Manual

CHAPTER 4 IMAGE FORMATION SYSTEM
VI. DEVELOPING ASSEMBLY/DRUM CLAENER
A.

Outlines

The paddle inside the drum cleaning unit and also the developing cylinder are rotated by the
main motor.
The amount of toner in the developing assembly is sensed by the black toner level sensor
(TS1).
When the amount of toner falls below the required quantity, the Add Toner indicator on the
control panel will flash.
The toner collected by the cleaning blade is stored in the drum cleaning unit.
The developing assembly is pressed against the drum by the cams that press against the devel-
oping assembly rail. (The cams are operated by the developing assembly release lever.)
B.

Remaining Toner Sensor

The black developing assembly has a piezoelectric type sensor (TS1) which senses if the toner
remaining in the hopper of the developing assembly is above or below the required level.
When the amount of toner in the hopper is sufficient, the sensor output is '1'. When it is below
the specified level, the output is '0'.
The DC controller makes checks for 30 seconds during copying, if the TONER EMPTY signal
(BTEP) is being outputted. If the signal is outputted continuously for 30 seconds, it is regarded as
TONER OUT and the DC controller makes the Add Toner indicator flash.
Drum cleaning unit
C.

Torque Limiter

There is a torque limiter in the drive train between the main motor and the drum to stop the
drum in response to a jam in the drum cleaner.
4-14
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Main motor
M1
Torque
Cleaning
limiter
blade
Photosensitive
drum
Paddle
DC controller PCB
Figure 4-601
COPYRIGHT © 1999 CANON INC.
Black developing
assembly
Black toner level
sensor (TS1)
Developing cylinder
TONER EMPTY
singnal(TEP)
CANON NP6320 REV.0 DEC. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Pressed Released
Developing assembly
positioning cam
Stirrer
Developing assembly rail unit