Patent ID: 7340192

Claim:
A fixing apparatus of an image forming apparatus comprising: an endless heating member having a metallic conductive layer; a pressure member pressed to the heating member to form a nip to hold and convey a medium to be fixed having a toner image in a predetermined direction together with the heating member; an induction heating coil arranged on an outer periphery of the heating member to generate an induced current in the metallic conductive layer; and a temperature sensor to detect a temperature of the endless heating member, wherein the heating member is a heat roller, and the temperature sensor and the induction heating coil are sequentially arranged on a downstream side of the nip in a rotational direction of the heat roller, and when a rotational speed of the heat roller is assumed as S 1 , and a radius of the heat roller is assumed as r, and a response speed of the temperature sensor is assumed as t, an arrangement position θ(°) of the heat roller centering on a shaft thereof from a detection position on the heat roller by the temperature sensor to a position opposite to an upstream side end of the induction heating coil is set to θ(°)>S 1 ×t×360(2πr).