Toshiba 4560 Service Manual page 157

(5) Cleaning roller
This cleans the toner remaining on the drum at the fixing process. The cleaning roller is located so
that it can come in contact with the heat roller. The silicon oil soaked in the pressure roller is evapo-
rated by the heat roller, causing it to adhere to the surface of the heat roller. As a result, the cleaning
of the toner on the heat roller can be smoothly performed.
(6) Cleaning felt roller
This cleans the toner remaining on the drum at the fixing process. The cleaning felt roller is located
so that it can come in contact with the heat roller. The cleaning felt roller does not contain silicon oil.
(7) Thermistor-1
The surface temperature of the heat roller should be maintained within a fixed range, (actually, around
200 °C), i.e. higher than the minimum temperature at which improper fixing may occur, lower than the
maximum temperature at which "baking" may occur. The thermistor detects the surface temperature
of the heat roller. If the temperature is lower than the standard temperature, it turns ON the heater
lamp, if higher, it turns it OFF.
(8) Thermistor-2
Temperature distribution in the axis of the heat roller may differ greatly at its center and ends by
conditions. Thermistor-2 detects the temperature at the heat roller end.
When either thermistor-1 or -2 detects a temperature above the specified ones, the heater lamp is
turned OFF by their thermal controls.
(9) Thermostat
When the surface temperature of the heat roller becomes excessively high due to thermistor failure,
etc., the thermostat stops the power supply to the heater lamp.
As the thermostat used in this copier is a type which protects against abnormal operation, when it
detects an abnormal operation, it is set to stay OFF. Therefore, during repair, this should be replaced
together with other damaged parts in the fuser unit.
(10) Exit rollers
Through the exit rollers, the paper removed by the heat roller separation claws or pressure roller
separation claws exits smoothly onto the receiving tray via the ADU exit roller.
Nov. 1997 © TOSHIBA 12 - 3 4560/4570 FUSER