Patent ID: 6392197
Filing Date: 2002-05-21
Classification: G03G,H05B

Abstract:
A ceramic heater for a toner-fixing unit which unit:(a) comprises: (a1) a heating cylinder provided with a ceramic heater along the longitudinal direction of the outer surface of the cylinder; (a2) a continuous heat-resistant film revolving along the periphery of the heating cylinder; and (a3) a pressure roller that forms a nip portion together with the heat-resistant film at the outer region of the roller opposite to the ceramic heater on the heating cylinder and that rotates to revolve the heat-resistant film at the same speed as the peripheral speed of the pressure roller; (b) feeds a copying sheet to the nip portion by the revolution of the heat-resistant film and the pressure roller; and (c) fixes a toner image on the copying sheet by the pressure of the pressure roller and the heat from the ceramic heater on the heating cylinder; the ceramic heater comprising:(d) a ceramic base material in which at least one part of the face that contacts the heat-resistant film is curved when viewed from a direction perpendicular to the feeding direction of the copying sheet; (e) a heating element, made of silver or silver alloy, formed on the ceramic base material; and (f) current-feeding electrodes, made of silver or silver alloy, formed on the ceramic base material.