Nitto Kogyo Co., Ltd.

Yasuhide Hamada

Yuichiro Higashi

Kesaaki Kitazawa

The present invention provides a fixing apparatus includes a fixing roller, a heating sourcefor allowing the outer peripheral surface of the fixing rollerto have a given temperature capable of performing a fixing operation, a pressing rollerin rotational contact with the fixing roller, and a biasing memberfor allowing the pressing rollerto be brought into press contact with the fixing rollerat a given pressure. The fixing apparatus is operable to allow a sheet with a surface supporting an unfixed toner thereon to pass through the rotational contact region along one direction so as to fix the unfixed toner onto the sheet. In this fixing apparatus, the fixing rolleris disposed on the side of the sheet surface supporting the unfixed toner, and the pressing rolleris disposed on the opposite side of the fixing rollerwith respect to the sheet. Further, the biasing memberis adapted to apply a biasing force to the pressing roller in a direction Y intersecting with an axis X connecting the respective center positions of the fixing rollerand the pressing roller

Fixing apparatus

A toner image fixing apparatus has a fixing roller, a pressing roller, and a heating roller. The pressing roller is normally urged toward the fixing roller for pressing a sheet with an unfixed toner image carried on a surface thereof against the fixing roller to fix the unfixed toner image to the sheet when the sheet passes in one direction through a rolling contact region between the fixing roller and the pressing roller. The heating roller is disposed on one side of the fixing roller opposite to the pressing roller. A first heat source is disposed in the heating roller for heating the heating roller, and a second heat source is disposed in the pressing roller for heating the pressing roller. An endless heat transfer belt is trained around the heating roller and the fixing roller for transferring heat from the first heat source to heat the unfixed toner image on the sheet when the sheet passes through the rolling contact region. When the apparatus is in a standby mode, a controller energizes the first heat source and the second heat source. When the apparatus is in the sheet feed mode, the controller energizes the first heat source, and also energizes the second heat source only if the sheet is of a size larger than a predetermined size.

Toner image fixing apparatus capable of keeping constant fixing roller temperature

The present invention provides a fixing apparatus which can secure a sufficient fixing performance even if a nip pressure is arranged in relatively low value. A fixing apparatus comprises a fixing member (,) having an elastic layer (,B,,B) formed on the fixing member at a side to which a sheet surface supporting an unfixed toner is contacted; a pressing member (,) for making the sheet surface supporting the unfixed toner contact to the fixing member (,) with a particular pressure and forming a nip portion between the fixing member and the pressing member; and a heating means (,) heating the fixing member(,), wherein 0.05&lE;P&middot;t/E&lE;0.50 is satisfied, where t (mm) is thickness of the elastic layer (,B,,B), E (Pa) is Young's modulus of the elastic layer (,B,,B) and P (Pa) is pressure in the nip portion.

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Tokyo, Japan

Yasuhide Hamada