Patent ID: 8027600

Claim:
An apparatus for image formation comprising: a fixing member; a pressing member; the fixing and pressing members forming a nip therebetween and adapted to fix a developer image on a record medium by heating and pressing the medium while the medium is passing through the nip; a heating member for heating at least one of the fixing and pressing members during a heating operation; a sensor for sensing the surface temperature of at least one of the fixing and pressing members; and a controller for stopping the heating operation of the heating member if the surface temperature sensed by the sensor exceeds a threshold temperature, and for starting the heating operation of the heating member if the sensed temperature drops below the threshold temperature; the controller including a period measuring unit for measuring the switching period at which the controller switches the starting and stopping of the heating operation of the heating member; wherein the controller restrains the heating of the fixing and pressing members if the switching period exceeds a reference time.