Patent ID: 7558498

Claim:
A fixing unit for use in passing a recording medium carrying an unfixed image between a pair of rotating bodies which are rotated while being pressed to each other to heat and press the recording medium thereby fixing the unfixed image to the recording medium, comprising: a first heater which generates heat energy with electric current supplied from a power source to heat up one of the rotating bodies; a second heater which generates heat energy with the electric current supplied from the power source to heat up the other of the rotating bodies or other components; and a switch which changes over a first state that the first heater and the second heater are serially connected to and supplied with the electric current from the power source and a second state that the first heater is connected to and supplied with the electric current from the power source while the second heater is substantially disconnected from the power source, wherein the relation: Q 11 /Q 21 >1/8 is satisfied, where Q 11 denotes energy of the first heater in the first state per unit of time and Q 21 denotes energy of the first heater in the second state per unit of time.