Patent ID: 8526836

Claim:
A fixing device comprising: a fixing member; a pressure member; a heating member for heating the fixing member at a heat quantity corresponding to an amount of power supplied; and a temperature control section for controlling an amount of power to be supplied to the heating member, the fixing member and the pressure member being rotatably provided, the fixing member and the pressure member carrying recording material provided between the fixing member and the pressure member while sandwiching the recording material between the fixing member and the pressure member, the fixing member and the pressure member fixing, onto the recording material, an unfixed image formed on the recording material by heat and pressure while carrying the recording material, the control section including: a temperature detecting section for detecting a temperature of the fixing device; a temperature storage section for storing a temperature detection result obtained by the temperature detecting section; a temperature difference calculating section for calculating a first temperature difference and a second temperature difference, the first temperature difference being a difference between (a) a first detected temperature that is a current temperature of the fixing member which temperature is detected by the temperature detecting section and (b) a control target temperature of the fixing member, the second temperature difference being a difference between (a) the first detected temperature and (b) a past temperature of the fixing member which past temperature was detected by the temperature detecting section a predetermined time earlier than the current time; a table storage section for storing an output setting table in which a combination of the first temperature difference and the second temperature difference is associated with information for specifying the amount of power to be supplied to the heating member; an output determining section for reading out, from the output setting table, the information corresponding to the combination of the first temperature difference and the second temperature difference which are calculated by the temperature difference calculating section and for determining the amount of power to be supplied to the heating member based on the information; and a power control section for controlling an actual amount of power supplied to the heating member in accordance with the amount of power to be supplied to the heating member which amount is determined by the output determining section.