Patent ID: 9342002
Filing Date: 2016-05-17
CPC Classification: G03G

Claim Text:
1. A fixing device comprising: a rotary member including a heat generation layer; an excitation coil generating magnetic flux, disposed along an axial direction of the rotary member, to heat by induction the heat generation layer of the rotary member; a first demagnetizing coil layered on the excitation coil and generating magnetic flux in a direction reverse to and cancelling out the magnetic flux that the excitation coil generates; a sheet size detector to obtain a size of a recording sheet on which an image is to be formed by passing through the rotary member; a drive controller to control driving of the first demagnetizing coil; and a second demagnetizing coil layered on the excitation coil and generating magnetic flux in a direction reverse to and cancelling out the magnetic flux that the excitation coil generates, wherein the drive controller drives the first demagnetizing coil after information including the sheet size has been obtained, and wherein the second demagnetizing coil is disposed opposite the center portion in the axial direction of the rotary member, and the drive controller obtains the information of the recording sheet to be passed through the rotary member including the sheet size information and controls to drive the second demagnetizing coil.