Patent ID: 8155541

Claim:
A fixing device comprising: a fixing member which fixes a developer image to a recording medium; a first heat generation member which heats the fixing member; a second heat generation member which has a different heat generation peak position from a heat generation peak of the first heat generation member in a direction of a rotation axis of the fixing member and heats the fixing member; a third heat generation member which heats the fixing member overlap for the heat generation peak positions of the first heat generation member and the second heat generation member; a first temperature detection member provided near the heat generation peak position of the first heat generation member; a second temperature detection member provided near the heat generation peak position of the second heat generation member; a circuit member which performs on-off control of the first heat generation member, the second heat generation member and the third heat generation member; and an anomaly detection member which turns off the first heat generation member and the second heat generation member, turns on only the third heat generation member for a third predetermined time, detects a quantity of temperature change in the fixing member during a lapse of the third predetermined time after only the third heat generation member starts being on, by using the first temperature detection member or the second temperature detection member, and inspects whether the quantity of temperature change is within a third predetermined range or not.