PURPOSE: To prevent transfer paper from being wound into a press-contacting roller and a heat roller and from the contamination of the rollers, by providing a separating ring, which has a larger diameter than those of the rollers, on the circumference of either roller so that the ring is internally brought into contact with the part of said rollers.

CONSTITUTION: A separating ring 8 has a larger than that of a heat roller 1 and is fitted being brought into contact with a heat roller 1 at the contact with a press- contacting roller 2. Since the press-contacting roller 2 is made of an elastic material, it is press-contacted with the circumferential surface of the heat roller 1 and the external circumferential surface of the separating ring 8 and although there is a little difference in pressing force to both, passing transfer paper is heated and press-contacted nearly uniformly to be fixed. The tip end 3a of an upper guide plate 3 is so provided that it projects toward the heat roller 1 from the external circumference of the separating ring 8 and the leading end of the transfer paper passed through the press-contact part abuts the guide plate 3 and is carried along a normal path without fail, so that said paper is not wound with the rollers.