Fixing device, heating device, image forming apparatus, and method of manufacturing heating device

A heating device comprising:

• a heating layer that generates heat, when energized, so as to heat a fixing member, the fixing member fixing a toner image to a recording medium;
• and
• an insulating layer that encloses the heating layer so as to electrically insulate the heating layer;
• wherein the insulating layer has a curved shape corresponding to an inner peripheral surface of the fixing member, in a state in which no external force is applied.

An image forming apparatus comprising:

• a toner image forming unit that forms a toner image;
• a transfer unit that transfers the toner image to a recording medium;
• a fixing member that fixes the toner image to the recording medium;
• a pressure member that forms, together with the fixing member, a pressure portion through which the recording medium carrying the toner image yet to be fixed passes;
• and
• a heating member including
• a heating layer that generates heat when energized, and
• an insulating layer that encloses the heating layer so as to electrically insulate the heating layer;
• wherein the heating member has a curved shape along an inner peripheral surface of the fixing member, in a state in which no external force is applied, and is in contact with the inner peripheral surface of the fixing member.

A method of manufacturing a heating device, comprising:

• heating a multilayer structure, the multilayer structure including
• a heating layer that generates heat when energized,
• a support layer that supports the heating layer, and
• an adhesive layer that is made of a material whose fluidity varies when heated and that bonds the heating layer and the support layer;
• supporting the multilayer structure in a curved shape;
• and
• reheating the multilayer structure while maintaining the curved shape.