摘要 |
Disclosed are a heating unit and its malfunction determining method, an image fixing device including the heating unit, and an image forming apparatus including the image fixing device. The method comprises a temperature detection step of detecting temperature of a heating body in the heating unit; a first malfunction determination step of obtaining a temperature rise time of the heating body, and then determining whether there is malfunction in the heating unit; and a second malfunction determination step of calculating a temperature increase rate of the heating body, and then determining whether there is malfunction in the heating unit.
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