Patent ID: 7212762

Claim:
An image forming apparatus having an image forming unit for forming a toner image on a printing medium as the printing medium is transported through the image forming unit and a fuser for applying heat to the printing medium to fuse the toner image onto the printing medium after the printing medium leaves the image forming unit, the image forming apparatus comprising: a heater for heating the fuser; a temperature sensor for sensing a temperature of the fuser; and a control unit for controlling the heater according to the temperature sensed by the temperature sensor to hold the fuser at a predetermined target temperature while the toner image is being fused onto the printing medium, and for preheating the fuser, responsive to a condition of the fuser, before the fuser applies heat to the printing medium; wherein the control unit compares the sensed temperature of the fuser with a threshold temperature higher than the target temperature, and causes the heater to preheat the fuser while the sensed temperature is less than the threshold temperature.