Ceramic heater for toner-fixing units and method for manufacturing the heater

摘要

A ceramic heater that is used in a toner-fixing system comprising a ceramic heater and a heat-resistant film, that reduces the degree of deformation of the heat-resistant film, that lightens the load applied to the film at the time of revolution, that prevents the fracture of the film, and that enables fixing at a high rate exceeding 24 ppm. A ceramic base material 11 of the ceramic heater attached to a heating cylinder comprises aluminum nitride or silicon nitride. A heating element 12 and current-feeding electrodes are made of heat-resistant metal such as tungsten and molybdenum or heat resistant alloy and are formed on the ceramic base material. In the ceramic heater, at least one part of the face (the fixing face) that contacts the heat-resistant film is curved when viewed from a direction perpendicular to the feeding direction of a copying sheet.