| 摘要 |
PURPOSE:To eliminate defective adhesion of a metallic ring occurring in the difference in the coefft. of thermal expansion of a metallic ring material for power feeding to be provided on a supporting roll having a surface consisting of a ceramic material by specifying the coefft. of thermal expansion of said material. CONSTITUTION:A material having <=20X10<-6>(l/K) coefft. of linear expansion is used as the annular electrodes 5, 5a of a heat fixing roll formed by providing an exothermic layer 3 on the surface of the supporting roll 2 having the surface consisting of the ceramic material and forming the annular electrodes 5, 5a, connected electrically to both ends of said exothermic layer thereto. The coefft. of thermal expansion of the ceramic material or ceramic layer to be used therein is usually <=10X10<-6>(1/K). Since the coefft. of thermal expansion of the adhesive layer is equalized in the above-mentioned manner, shearing forces do not act at all between both and the exfoliation of the adhesive surface does not arise. Electric power is thus stably supplied to the roll for a long period of time and the generation of defective contact, current leakage, etc., is obviated. |
