Patent ID: 8886064

Claim:
A fixing device for fixing a toner image in place on a recording medium, the fixing device comprising: a rotary, endless fuser belt subjected to heating, on which the recording medium is conveyed to fuse the toner image thereon; a heater for heating the fuser belt; a thermometer to detect an operational temperature of the fuser belt; and a controller operatively connected to the thermometer and the heater to deactivate the heater upon detecting an abnormal condition in which the operational temperature detected remains below a setpoint temperature after lapse of a warm-up time limit since activation of the heater, the controller including: a historical data recorder to record historical usage data of the fixing device since installation, and a processor to adjust the warm-up time limit according to the historical usage data recorded by the historical data recorder, wherein the warm-up time limit is initially set to a first value where the historical usage data indicates that the fixing device is in an unaged state, the first value representing a period of time required for the operational temperature of the fuser belt, as detected by the thermometer, to rise from a reference temperature to the setpoint temperature where the heater is operated with a lowest allowable power supply voltage in the fixing device in the unaged state.