Patent ID: 7783219
Filing Date: 2010-08-24
Classification: G03G

Abstract:
1. A fixing apparatus comprising: a fixing member which has a heat source and an elastic layer therein, the elastic layer being located close to an outer surface of the fixing member in relation to the heat source; a pressure member which is pressed against the fixing member so that a first nip area is provided between the pressure member and the fixing member, the first nip area causing a toner image formed on a recording paper to be fixed on the recording paper; an external heating device which has a heat source and is disposed on the outer surface of the fixing member so that a second nip area is provided between the external heating device and the fixing member, and a control device configured to control a temperature difference between a surface temperature of the external heating device and a surface temperature of the fixing member in accordance with a length of the second nip area in a direction of transport of the recording paper, so that the surface temperature of the fixing member is maintained to fall within a temperature range in which offset does not occur, the offset being a phenomenon in which part of a toner formed on the recording paper sticks onto a surface of the fixing member due to overheating or insufficient heating of the recording paper, wherein the control device is configured to control power supply to the heat source of the fixing member and the heat source of the external heating device giving a first priority to power supply to the heat source of the external heating device until the external heating device reaches a setting temperature for warm-up.