Fusing - Oki OF5700 Service Manual

(6) Fusing

After the end of the transfer operation, the unfused toner image is fused on the paper under heat and pressure as it
passes between the heater roller and the back-up roller. The heater roller with a Teflon coating incorporates a 500 W
heater Halogen lamp), which heats the heat roller.
A thermister, which is in contact with the heater roller regulates the heater roller at a predetermined temperature
(about 185 °C for OKIFAX 5000 series). A safety thermostat cuts off voltage supply to the heater by opening the
thermostat in the event of abnormal rise in temperature.
The back-up roller is held under a pressure of 3.76 kg applied by the pressure spring on each side.