| 摘要 |
PURPOSE:To prolong a useful service life of a heat roller by pressing a separating claw formed by a shape memory alloy against the heat roller, only when the heat roller is below a fixing control temperature, and also, exceeds a set temperature being above a stand-by rotation start temperature. CONSTITUTION:A separating claw 10 is formed by a shape memory alloy which returns to its original shape at a martensite transformation temperature (storage temperature), and constituted so that at a temperature below the storage temperature, it holds the first state P1 that the tip is separated from a heat roller 3, and at the time of exceeding the storage temperature, it is transformed to the second state P2 that the tip is pressed against the surface of the heat roller 3. In this regard, the storage temperature is set in advance to a temperature heated by the influence from the heat roller 3, when the heat roller 3 is heated by a heater 4, it is above a fixing stand-by rotation start temperature, and also has become a separating claw press-contacting temperature being below a fixing control temperature. In such a way, a useful service life of the heat roller 3 can be extended.
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