Image fixing apparatus with power control during sheet passage

摘要

An image fixing apparatus includes a heater; a detector for detecting a temperature of the heater; a controller for controlling electric power supply to the heater to provide a predetermined constant temperature detected by the detector; a rotatable member heated by the heater; a pressing member cooperable with the rotatable member to form a nip through which a recording material is passed through; and wherein the controller is capable of switching the predetermined temperature during one recording material is being passed through the nip.