Image fixing device

摘要

A fixing device configured to fix an image on a recording material, includes: a rotary member including an electroconductive layer; a coil which has a spiral shaped portion and is disposed in the inside of the rotary member; and a core disposed in the spiral shaped portion; with magnetic resistance of the core being, with an area from one end to the other end of the maximum passage region of the image on the recording material regarding the generatrix direction, equal to or smaller than 30% of combined magnetic resistance made up of magnetic resistance of the electroconductive layer and magnetic resistance of a region between the electroconductive layer and the core.

主权项

1. A fixing device configured to fix an image on a recording material by heating the recording material where the image is formed, comprising:
a cylindrical rotary member including an electroconductive layer; a coil configured to form an alternating magnetic field which subjects the electroconductive layer to electromagnetic induction heating, the coil including a spiral shaped portion which is disposed in the rotary member so that a spiral axis of the spiral shaped portion extends along a generatrix direction of the rotary member; and a core configured to induce magnetic force lines of the alternating magnetic field, the core being disposed in the spiral shaped portion; wherein magnetic resistance of the core is, with an area from one end to the other end of the maximum passage region of the image on a recording material in the generatrix direction, equal to or smaller than 30% of combined magnetic resistance made up of magnetic resistance of the electroconductive layer and magnetic resistance of a region between the electroconductive layer and the core.