An image forming apparatus, comprising:
- an image forming unit which forms a toner image;
- a transfer unit which transfers the toner image formed by the image forming unit onto a recording medium;
- and
- a fixing apparatus which fixes the toner image onto the recording medium;
- wherein the fixing apparatus includes:
- a magnetic flux generating source which generates a magnetic flux;
- an endless belt which inductively generates heat by the magnetic flux while rotating in a prescribed direction;
- a rotating body which rotates in a prescribed direction and, together with the belt, forms a nip section through which the recording medium carrying the toner image passes;
- a core which is made of a magnetic material, and directs the magnetic flux to the belt;
- a heat value adjustment member that is disposed rotatably and adjusts an amount of heat generated in the belt, the heat value adjustment member being disposed to oppose the magnetic flux generating source and the core across the belt;
- and
- a gripping piece which is a non-rotating member, is disposed in a position corresponding to the nip section, and contacts an inner surface of the belt to rotatably grip the belt against the rotating body;
- and
- wherein the belt is wrapped between the heat value adjustment member and the gripping piece, and
- the heat value adjusting member is rotated in accordance with a width dimension of a recording medium in a direction perpendicular to a conveyance direction of the recording medium passing through the nip section so that overheating is suppressed in the region outside the recording medium passage region of the belt,
- the magnetic flux generating source is a winding disposed to oppose the outer circumferential surface of the belt at a position opposite to the rotating body with respect to the belt,
- the core has a center core surrounded by the magnetic flux generating source and opposes the belt in a region where the magnetic flux generating source is not present, and
- the belt has a prescribed rigidity and contacts an outer circumferential surface of the heat value adjustment member at a position where the heat value adjustment member opposes the center core and a position in the vicinity thereof, and the belt does not contact the outer circumferential surface of the heat value adjustment member at a position where the heat value adjustment member opposes the magnetic flux generating source.