HEAT ROLLER FOR COPYING MACHINE

PURPOSE:To shorten considerably the rise time to a prescribed temperature, by providing a heat roller and a coil in one longer side part and the other of a loop iron core and by heating the metallic thin layer of the roller by an induced voltage. CONSTITUTION:One longer side part of a loop iron core 1 is formed to have an angular section, and a roller part 3 is provided freely rotatably through a bearing part in this longer side part. The roller part 3 consists of a pipe-shaped insulating material 4 having a mechanical strength and metallic thin layer 5 and an insulating layer 6 which are thin on the material 4. A coil 2 is fitted to the other longer side part of the iron core 1. In this constitution, when an AC power source is connected to the coil 2, the magnetic flux of the iron core 1 is changed by the frequency, and a voltage is induced only in the metallic thin layer 5 near the surface of the roller part 3 to heat this layer 5. Since the metallic thin layer 5 is thin to reduce the heat capacity sufficiently, the rise time is shortened considerably in comparison with the conventional heat roller using radiant heat.