Patent ID: 7155154

Claim:
A fixing device comprising: a fixing belt module composed of a fixing roller having a heat source, two or more tension rollers at a fixing side and an endless fixing belt looped and stretched around the fixing roller and tension rollers to thereby rotate; and a pressure belt module including an endless pressure belt that comes in contact with an outer peripheral surface of the fixing belt only within a range of a section where the fixing belt is wrapped around a surface of the fixing roller, thereby forming a nip section for fixation between itself and the fixing belt, wherein the fixing belt module includes a fixing belt heating unit that comprises at least two of the tension rollers that have respective heat sources, at least one of the tension rollers with the heat source heating by contact an inner peripheral surface of the fixing belt and at least one of the tension rollers with the heat source heating by contact an outer peripheral surface of the fixing belt at any sections other than the section where the fixing belt is wrapped around the outer peripheral surface of the fixing roller.