FIXING DEVICE AND IMAGE FORMING APPARATUS INCORPORATING SAME

摘要

A fixing device includes a rotatable fixing member, a pressing member, and an induction heater. The induction heater includes an excitation coil, ferromagnetic cores, and a holder. The ferromagnetic cores include multiple arch cores and multiple side cores. The multiple arch cores are disposed facing an outer surface of a heat generation layer with the excitation coil interposed therebetween. The multiple side cores are disposed outside the excitation coil in a longitudinal direction of the induction heater so as to face both ends of each of the multiple arch cores. The multiple side cores are integrally inserted in the holder. The holder includes a spacer. The spacer contains a resin material used in the holder and provided in a close-facing portion located between at least one of the multiple arch cores and at least one of the multiple side cores to form a gap.

主权项

1. A fixing device comprising:
a rotatable fixing member, comprising one of a roller and a belt; a pressing member to press against the fixing member; and an induction heater serving as a heating source to heat the fixing member, the induction heater including:
an excitation coil to inductively heat a heat generation layer;ferromagnetic cores to form a continuous magnetic path to direct magnetic flux arising from the excitation coil to a predetermined position; anda holder to hold the excitation coil and the ferromagnetic cores,the ferromagnetic cores including multiple arch cores disposed facing an outer surface of the heat generation layer with the excitation coil interposed therebetween and multiple side cores disposed outside the excitation coil in a longitudinal direction of the induction heater so as to face both ends of each of the multiple arch cores,the multiple side cores integrally inserted in the holder,the holder including a spacer,the spacer containing a resin material used in the holder and provided in a close-facing portion located between at least one of the multiple arch cores and at least one of the multiple side cores to form a gap.