FIXING DEVICE AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a fixing device capable of surely preventing an excessive temperature rise in an area where no paper sheet passes of a fixing belt.SOLUTION: The fixing device comprises: a shielding member 27 which is provided rotatably around a halogen heater 23 (a heat source) and shields heat from the halogen heater 23 to a fixing belt 21 (a fixing member); and a controller to control a rotation angle of the shielding member 27. The shielding member 27 comprises: a shielding part 48 provided in an area covering a part of the halogen heater 23 in the axial direction; and an opening part 50 provided adjacently to one side of the shielding part 48 in the axial direction. The shielding part 48 extends along the inner peripheral surface of the fixing belt 21 and is formed to have ends in the circumferential direction. The controller determines the rotation angle of the shielding member 27 on the basis of paper sheet size and temperature of the fixing belt 21 or a pressure roller 22.