Temperature control method for use in a fusing device of an image forming apparatus having a fusing roller and a heater heating the fusing roller and image forming apparatus using the same

A temperature control method for use in a fusing device of image forming apparatus having a fusing roller and a heater heating the fusing roller, comprising:

• sensing a surface temperature T of the fusing roller at one of when the image forming apparatus is turned on, when the image forming apparatus begins a normal operation from a power saving operation, and when a cover of the image forming apparatus is closed after being opened;
• comparing the sensed surface temperature T of the fusing roller with a set temperature;
• driving the heater until the surface temperature T reaches a first target temperature Tt1 when the sensed surface temperature T is below the set temperature;
• and
• driving the heater until the surface temperature T reaches a second target temperature Tt2 when the sensed surface temperature T is over the set temperature,
• wherein the first target temperature Tt1 is one of a temperature Tv so that the surface temperature T of the fusing roller is increasable to the third target temperature Tt3 when the heater is turned off after heating the surface temperature T of the fusing roller to the first target temperature Tt1, and a temperature higher than the temperature Tv.