Patent ID: 7286780

Claim:
An image formation apparatus comprising: a fuser having a heater used in forming an image to provide thermal fixation; a temperature detector detecting a temperature of said fuser; and a temperature controller controlling said heater based on a resultant detection of said temperature detector, wherein: said fuser includes a hot roller heated by thermal conduction provided by said heater, a pressurization roller cooperating with said hot roller to pressurize a sheet inserted, and a temperature detection element transmitting a voltage in accordance with a temperature; said temperature controller includes: a pulse signal generation circuit operative in response to an instruction to output a pulse signal and also to adjust a duty ratio of said pulse signal, a first digital port outputting said pulse signal from said pulse signal generation circuit, and a second digital port receiving a digital signal corresponding to said resultant detection of said temperature detector; said temperature detector includes: a smoother circuit receiving said pulse signal from said pulse signal generation circuit to smooth and output said pulse signal as a reference voltage, and a comparator comparing the voltage transmitted from said temperature detection element with said reference voltage to output a resultant comparison to said temperature controller; and said pulse signal generation circuit adjusts said duty ratio of said pulse signal in accordance with a mode.