| 摘要 |
PROBLEM TO BE SOLVED: To perform proper temperature distribution in a width direction of a recording medium.SOLUTION: A fixing apparatus 20 includes a fixing belt 24 stretched on a heating roller 21 and a fixing roller 22, and a pressure roller 23 which forms a nip part with the fixing roller 22. The fixing apparatus includes induction heating means 30 which comprises: a plurality of excitation/demagnetization coils 31a, b, which have different lengths in an axial direction of a heating roller 21, of which a coil with the maximum axial length has other coils arranged on its inner periphery, and each of which coils is controlled to be connected to a resonance circuit 35 or to be short-circuited thereby to be switchable between excitation state where an alternate magnetic flux is generated to induction-heat the heating roller 21 and a demagnetization state where an alternate magnetic flux generated by the other coil is cancelled; the resonance circuit 35 for supplying an AC current to the excitation/demagnetization coils 31a, b; and a switching circuit 34 which controls a connection state and a shirt-circuit state between the resonance circuit 35 and the plurality of excitation/demagnetization coils 31a, b. |
