PURPOSE: To enlarge the nip of a pressure roller in press-contact with a fixing heat roller and to improve fixing performance by forming many projections on the peripheral surface of the pressure roller in press-contact with the fixing heat roller.
CONSTITUTION: Both ends of a mandrel 15 are supported by bearings and the peripheral surface of an elastic layer 9 with which the mandrel 15 is coated is caused to press-contact with the fixing heat roller 1. The projection 9a formed on the peripheral surface of the elastic layer 9 has a circular base diameter equal to or under nip width formed by press-contact and is formed in a round shape. By forming many projections 9a on the peripheral surface of the pressure roller 3, surface tension is reduced in a state where the roller 3 is in press- contact with the roller 1 in comparison with the conventional pressure roller having a smooth peripheral surface, and the nip is enlarged as much as the reduction of the surface tension. Furthermore, in the case of fixing an unfixed toner image on recording paper, the recording paper can more widely be brought into press-contact with the roller 1. Therefore, contact time and the quanty of heat are increased and the toner image is surely fixed.
TAMAOKI SHUNPEI
KIUCHI YASUSHI
SAKATA YOSHIO
KAKEHASHI YASUSHI
KANEGAFUCHI CHEMICAL IND