Patent ID: 7529515

Claim:
An image forming apparatus comprising: an image carrier which holds a developer image in an electrostatic manner; and a fixing apparatus which fixes the developer image onto a recording medium to which the developing material image has been transferred, the fixing apparatus comprising: a heating unit including a first roller fixed at a predetermined position and rotated by a drive mechanism; a pressuring unit including a second roller being pressed against the heating unit; an elastic layer formed at least at one of the first roller and the second roller; a conductive layer formed outside of the elastic layer; an inductive heating device including a coil, the inductive heating device supplying inductive heating to the conductive layer by a magnetic field generated from the coil, thereby heating the conductive layer; and a hardness change detecting mechanism which detects a hardness change of the first roller or the second roller, the hardness change detecting mechanism including a switch configured to be depressed to detect an expansion of the first roller or the second roller.