a fixing roller and a pressure roller form a nip therebetween to fix a recorded image onto a recording sheet provided into the nip . a coil provides alternating magnetic field with respect to the fixing roller to inductively heat the fixing roller . the coil includes a plurality of coil segments arranged in an axial direction of the fixing roller . the coil segments are connected in a manner of either forward connection or alternate connection . a controller determines either the forward connection or the alternate connection such that an heating efficiency due to the induction heating has a larger value .