Patent ID: 7783217

Claim:
A fixing apparatus comprising: a fixing roller; and a pressure roller, wherein a recording material is transported between the fixing roller and the pressure roller, so that an unfixed image formed on the recording material is fixed on the recording material under heat of the fixing roller, the fixing apparatus further comprising: an external heating member which heats the outer surface of the fixing roller by external contact with the outer surface of the fixing roller; and a temperature control section which controls a temperature of the external heating member in accordance with a transport speed of the recording material, wherein: the external heating member is an endless belt which is set over a plurality of support rollers, the temperature control section is made up of (i) a first heat source device which is a heat source of the external heating member and heats in response to power supply to the first heat source device, (ii) a first temperature sensor which detects a temperature of the external heating member, and (iii) a heat source control device which controls power supply to the first heat source device so that the temperature detected by the first temperature sensor reaches a first setting temperature, the heat source control device selects a value of the first setting temperature in accordance with a transport speed of the recording material, the fixing apparatus includes (a) a second heat source device which is disposed inside the fixing roller and heats in response to power supply to the second heat source device and (b) a second temperature sensor which detects a temperature of the outer surface of the fixing roller, the heat source control device controls power supply to the first heat source device and the second heat source device so that the temperature detected by the first temperature sensor takes the first setting temperature and the temperature detected by the second temperature sensor takes a second setting temperature, and the temperature control section sets the first setting temperature and the second setting temperature to an identical value under standby conditions where image forming operation is not performed by the image forming apparatus which includes the fixing apparatus.