Canon NP6012 Service Manual page 79

4. Checking the Waste Toner
When the photosensitive drum rotates,
its drive is transmitted through the drum
gear, coupling gear, and toner feeding blade
drive gear in order. The toner feeding blade
serves to forward waste toner collected by
the cleaning blade to the inside of the drum
unit.
The coupling gear transmits drive by
keeping two gears in contact by the work of
a spring.
Paper select
When the inside of the drum unit
becomes full of waste toner, the load against
rotating the toner feeding blade increases.
Further, when torque is imposed on the
toner feeding blade, the coupling gear
becomes disengaged, cutting the drive to
the toner feeding blade, thereby causing the
flag to move away from the waste toner sen-
sor (PS5). When the flag leaves the waste
toner sensor, the Replace Drum Cartridge
indicator (@2>) on the control panel starts to
flash; in the case of a model with the drum
unit replacement automatic indication func-
tion, the indicator turns on.
Waste toner
Waste toner
(PS5)
Toner feeding blade
DC controller PCB
Photosensitive drum
Coupling gear
Figure 3-318
3-34 COPYRIGHT © 1995 CANON INC,
CANON NP5OI2/NP6OTZF /NP6212 REV.A SEPT. 1995 PRINTED IN JAPAN (IMPRIME AU JAPON)