Patent ID: 9217967
Filing Date: 2015-12-22
Classification: G03G

Abstract:
1. An induction heating fusing device comprising: a pressure roller; a heating element arranged to form a fusing nip together with the pressure roller and that is rotatable; an inductor that is installed in a rotation axis direction on the outer circumference surface of the heating element, the inductor comprising a main coil and a plurality of control coils and being configured to inductively heat the heating element; and a controller comprising a plurality of switching devices that switch connections of the main coil and the plurality of control coils, the controller being configured to selectively operate at least one of the plurality of control coils depending on a width of a printing paper passing though the fusing nip, wherein a current direction in the at least one selectively operated control coil of the plurality of control coils is reversed according to an ON/OFF combination of the plurality of switching devices, and wherein the controller controls the plurality of switching devices to form the ON/OFF combination of the plurality of switching devices so that the current direction of the at least one selectively operated control coil of the plurality of control coils becomes opposite to the current direction of the main coil when the width of a printing paper passing though the fusing nip is small, and controls the plurality of switching devices to form the ON/OFF combination of the plurality of switching devices so that the current direction of the at least one selectively operated control coil of the plurality of control coils becomes the same as the current direction of the main coil when the width of a printing paper passing though the fusing nip is large.