| 摘要 |
PURPOSE:To make construction simple and eliminate the need for maintenance of a heater by forming a roll core body by a ceramic heater comprising heating conductors buried in a ceramic body. CONSTITUTION:A cylindrical core body 2a obtained by extrusion-molding the green material of a ceramic material, such as alumina, of superior heat resistance, thermal conductivity, and electrical insulation characteristic, and a green ceramic sheet 2c consistig essentially of alumina formed with heating conductors 2b on one side are prepared. The heating conductors 2 are formed by printing conductive paste on the green ceramic sheet 2c by a thick film technigue such as screen printing so as to enable the heating resistance value required for fixing of toner images to be obtained. The sheet 2c formed with the heating conductors 2b is wound on the outside circumference of a core material 2a with the side of the heating conductors 2b brought on the inner side. The cylindrical green ceramic body is calcined in a reducig atmosphere of 1,400-1,600 deg.C, whereby it is sintered into one piece, thence the cylindrical surface is finished by polishing. |
