Canon i-SENSYS D450d, Service Manual, Page: 83 / 182

Chapter 6
6-3
6.3 Toner Cartridge
6.3.1 Toner Level Detection
0020-2694
i-SENSYS MF4300dn / i-SENSYS MF4350d / i-SENSYS MF4380dn / i-SENSYS MF4310/4318 / i-SENSYS MF4320d / i-SENSYS MF4330d / i-SENSYS
MF4340d / i-SENSYS D450d / i-SENSYS MF4370dn
Overview
The toner sensor (magnetic sensor) detects the remaining toner level.
When a toner cartridge is inserted, the toner sensor becomes in contact with the lower part of the cartridge and converts the magnetic force change in the cartridge
filled with the toner into voltage.
The MPU of the DCNT PCB compares this output voltage of the toner sensor with the reference value, and detects the toner level.
If the toner level comes near approx.100 sheets (standard original), the following message is shown on the display.
When the toner cover is opend, the message will disappear.
[TONER LOW
PREPARE NEW TONER]
If the toner cartridge is not exchanged, the message is shown again when the toner cover is closed.
Toner detections sequence
Detection is performed per 2.16 sec after 550 ms passing since the main motor was activated. The CPU of the DCNT PCB compares the output voltage of the toner
sensor with the reference value.
At initialize rotation after power-on and opening/closing the toner cover, it is detected once at 4.32 sec.