Patent ID: 8358948

Claim:
A fixing device for fixing a toner image on a recording medium, comprising: a fixing rotary body heated by a heater; a pressing member pressed against the fixing rotary body to form a fixing nip therebetween through which the recording medium bearing the toner image passes, each of the fixing rotary body and the pressing member including a core and a waveform elastic layer provided on the core and having at least one wave crest and at least one wave trough to form a waveform face between the fixing rotary body and the pressing member where the wave trough of the pressing member is pressed against the wave crest of the fixing rotary body and the wave crest of the pressing member is pressed against the wave trough of the fixing rotary body; a first temperature detector disposed on a surface thereof opposite the wave crest of the fixing rotary body to detect a first temperature thereof; a second temperature detector disposed on a surface thereof opposite the wave trough of the fixing rotary body to detect a second temperature thereof; and a controller connected to the heater, the first temperature detector, and the second temperature detector to identify a temperature differential between the first temperature and the second temperature and adjust an amount of heat stored from the heater into the fixing rotary body based on the identified temperature differential.