Brother HL-4040CN Service Reference Manual page 45

5. Fusing
The toner transferred on to the paper passes between the heat roller and the pressure roller
ASSY in the fuser unit and are fused by heat and pressure. The thermistor detects surface
temperature of the heat roller and turns ON/OFF the halogen heater lamp to keep the
temperature constant.
Thermistor
Halogen heater lamp
Memo:
Control of fusing temperature
The fuser unit adjusts such temperature according to types and sizes of paper so as to keep
excellent image quality.
Fig. Ref2-24
Ref. 2-25
Heat roller
Pressure roller ASSY
Fuser unit
Confidential