2-13
2.8.6 Fusing
An Overview
The toner image that is transferred on to the paper is securely fixed during the fusing process.
A heat roller system is used as the fusing system. The toner image is fused by Heater Roller heated by
the Heater Lamp, and securely fixed by the pressure between the Heater roller and Press roller.
A Thermistor detects and controls the Heater Roller temperature.
The Thermostat functions when the Heater Lamp is not turned OFF even if the Thermistor detects a high
temperature malfunction.
Fusing Temperature Control Circuit
The Thermistor detects the surface temperature of the Heater Roller and inputs that analog voltage into
the Main Control PCB. Corresponding to this data, the Heater Lamp ON/OFF signal is output to the Heater
ON/OFF switch of the power supply unit, causing the Heater Lamp to turn ON or OFF to control the fusing
temperature.
When the Heater Lamp is not turned OFF even if the Thermistor detects a high temperature malfunction,
the thermostat shuts down the power to the heater lamp. When the thermostat malfunctions, the thermal
cut-off shuts down the power to the heater lamp.
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Main Control PCB
Fusing temperture
control circuit
Power supply unit
AC Inlet
Fusing unit
Thermistor
Heater Lamp
Thermostat
Thermal cut-off
Heater
on/off
switch
Main switch
