Apparatus for image formation

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.