Image heating apparatus

Abstract

An image heating apparatus for heating an image includes a cylindrical rotatable member including an electroconductive layer; a helical coil provided in the rotatable member, the coil having a helix axis extending along a generatrix direction of the rotatable member; a magnetic core provided in the coil and having an end portion; and a controller configured to control a frequency of an AC current supplied to the coil; wherein the image is heated by heat of the rotatable member heated by electromagnetic induction heat generation of the electroconductive layer, wherein the controller sets the frequency to a first frequency corresponding to a size of a recording material, and wherein the controller sets the frequency to a second frequency higher than the first frequency when a print ratio of the image is larger than a predetermined value.

Dependencies are inferred from the claim text.