Fixing Unit System; Outline - Canon mf6600 Series Service Manual

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Technical Overview > Fixing Unit System > Outline

Fixing Unit System

Outline

The Fixing/Delivery Unit fixes the toner onto a print paper and delivers it to the Delivery Tray.
The operation of the Fixing/Delivery Unit is explained in the following.
1) The print paper fed from the Pickup/Feed Unit is fused the toner by the Fixing Film and the
pressure roller.
2) The print paper delivered from the Fixing Unit is delivered to the face-down Delivery Tray
or the face-up Delivery slot. When the engine controller detects that the heater temperature
reaches 50 deg C after the last rotation is completed, it drives the main Motor for 50 msec.
and dislocates the nip part. This prevents the toner adhering to the pressure roller.
The Fixing Unit of this printer utilizes the on-demand Fixing method. It is structured as shown
below.
- Heater:
This Fixing Unit incorporates one heater.
Fixing Heater (H1): To heat the Fixing Film (ceramic heater)
- Thermistor:
This Fixing Unit incorporates one thermistor.
Thermistor (TH1): Sit almost at the center of the Fixing Film. (contact type)
To control the temperature of the Fixing Film
- Thermal switch:
Thermoswitch (TP1): Sit almost at the center of the Fixing Film (contact type)
If the temperature of the heater rises abnormally high, the contact gets broken and
cuts off the AC Voltage Supply to the Fixing Heater to interrupt the power supply to the
heater.
2 Technical Overview > Fixing Unit System > Outline
The temperature control of the Fixing Unit incorporated as above is operated by the Fixing
temperature control circuit according to the command from the CPU (IC201) on the DC
Controller.
The followings describe the each circuit and function of the temperature control of the Fixing
Unit.
Thermistor
Fixing heater
Fixing temperature
control circuit
Engine controller PCB
2-20
Fixing unit
Fixing film
Thermoswitch
Pressure roller
CPU
F-2-25 F-2-25
2-20