PURPOSE: To eliminate the need for the motor to be exclusively used and to obtain a large aperture angle with a simple construction by dividing a device, providing an open-close member to freely openably and shuttably pivoted split parts and making the same connectable to the motor of a fixing device.

CONSTITUTION: A motor 11 for a fixing device 11 and an output gear 10 rotate a heating roll 5 via a gear 8 and a one-way clutch to perform fixing. On the other hand said motor and gear rotate an open-close gear 14 as well via a counter gear 13. The device body is vertically bisected with the paper passage as a boundary and tbe split parts are pivotally supported by a supporting shaft 3 so as to be made freely openable and shuttable. An upper frame 1 is opened and shut by changing over the driving route for the motor 11 and rotating the gear 14 around the shaft 3. The motor 11 is therefore used commonly and since the support 3 is provided at the end of the device, the aperture angle is increased and the change-over from the fixing device is easily performed.