Patent ID: 8045907

Claim:
A fixing device comprising: a fixing member that includes a conductive layer and that fixes toner on a recording medium by self-heating the conductive layer by electromagnetic induction; a magnetic field generating member that generates an alternate-current magnetic field intersecting with the conductive layer of the fixing member; a magnetic path forming member that includes a circular arc shaped portion arranged so as to face the magnetic field generating member with the fixing member interposed between the circular arc shaped portion and the magnetic field generating member, that forms a magnetic path of the alternate-current magnetic field generated by the magnetic field generating member, within a temperature range up to a permeability change start temperature at which a permeability starts to decrease in the circular arc shaped portion, and that allows the alternate-current magnetic field generated by the magnetic field generating member to go through the magnetic path forming member within a temperature range exceeding the permeability change start temperature; and a support member that supports the magnetic path forming member, wherein the magnetic path forming member is mounted on the support member so that a position of an upstream edge of the circular arc shaped portion in a moving direction of the fixing member is displaced in a direction away from the fixing member while the displacement of the position is larger toward a center of the magnetic path forming member from each of ends of the magnetic path forming member in a longitudinal direction.