Canon imageRUNNER ADVANCE 4551i Service Manual page 110

The toner in the toner cartridge is fed to the toner feed path and then to the developing assembly by the toner feed screw. The
toner presence/absence in the toner feed path is detected by the toner feed level detection sensor (S51) which is a magnetic
permeability sensor.
If the developing assembly toner level sensor(S25) detects the absence of the toner in the developing assembly, the toner feed
motor(M21) drives to rotate the toner feed screw to feed toner in the toner feed path to the developing assembly. Also, if the toner
feed level detection sensor (S51) detects the absence of the toner in the toner feed path, the bottle motor (M17) drives to rotate
the toner cartridge to feed the toner in the Toner cartridge to the toner feed path.
If the toner feed level detection sensor (S51) keeps detecting the absence of the toner for more than the specified period of time,
no toner in the toner cartridge is assumed and the message to replace the Toner cartridge will be displayed. Also, if the developing
assembly toner level sensor(S25) keeps detecting the absence of the toner for more than the specified period of time, no toner
in the developing assembly is assumed and a No Toner error message will be displayed.
Toner Cartridge
Developing Assembly
Toner Level Sensor
M17
Bottle Motor
Bottle motor
drive signal
■ Bottle State Detection
Purpose: To detect the state of the Toner Container
Detection timing
• At power-on
• When the Toner Bottle Exchange Door is closed
• At recovery from sleep mode
Bottle ROM PCB(UN76) detects the state of the bottle from the Toner Container memory [1].
Toner Feed
Screw
Toner Feed Path
Route of toner supply
S25
Developing Assembly
Developing Clutch
CL1
M1
Main Motor
Main motor
drive signal
DC Controller PCB
Toner Feed Level
S51
Detection Sensor
Toner Feed
Screw
Developing Clutch
drive signal
97
2. Technology
Toner Feed
Motor
M21