Patent ID: 7330688

Claim:
A fixing device, comprising: at least two support members, each support member being a roller; a belt wound around the at least two support members and movably supported in the circumferential direction of the at least two support members; a heat source that heats the belt; and a pressurizing member that contacts the belt with pressure; wherein a toner image is heated and fused on a recording medium by passing the recording medium on which the toner image is electrostatically formed through a fixing nip portion formed between the belt and the pressurizing member; the support members and the pressurizing member contact each other with pressure at an upstream side and a downstream side in a carrying direction of the recording medium; a first interposing portion of the belt disposed between the support members is inserted between the support members and the pressurizing member and installed in a tensed state, a second interposing portion of the belt is installed in a non-tensed state, and the pressurizing member contacts an outer surface of the first interposing portion to form the fixing nip portion; and the support members contact the pressurizing member with different pressures at the upstream side and the downstream side in the carrying direction of the recording medium.