Patent ID: 7890042

Claim:
An image forming apparatus, comprising: an image forming unit for transferring a toner image to a sheet; and a fixing unit including a heating member and a pressing member and adapted to convey the sheet while holding the sheet between the heating member and the pressing member and to fix the toner image to the sheet by heat at least from the heating member in a conveying process, wherein the fixing unit further includes: a coil arranged along an outer surface of the heating member for generating a magnetic field for induction heating the heating member; a core arranged to face the heating member with the coil located therebetween in order to form a magnetic path around the coil and made of a magnetic material; a shielding member arranged on a side of the outer surface of the heating member and near the magnetic path generated by the coil, including a closed frame portion and made of a nonmagnetic metal; and a magnetic shielding portion for displacing the shielding member between a retracted position for permitting a magnetic flux to pass along a frame surface virtually formed inside the closed frame portion and a shielding position for shielding magnetism by the penetration of a magnetic flux inside the frame surface.