| 摘要 |
PURPOSE:To form a heat fixing device where a practically uniform heating temperature is obtained throughout the overall length of a heat roll by extending an insulating layer on the outside circumference of a metallic hollow core up to shaft part of the hollow core. CONSTITUTION:When a heat roll 1 and a pressure roll 2 which are pressed to each other are rotated by a driving means such as a motor, a gear, or the like and, for example, a commercial AC voltage is to a feeding brush 13 brought into contact with electrodes 9a and 9b, a current is flowed to a resistance heating body layer 8 to heat it. When the surface of the heat roll 1 reaches a prescribed fixing temperature, a supporting material 16 holding a toner image 15 is allowed to pass between the heat roll 11 and the pressure roll 2 to obtain a fixed image. By this heat fixing device, the radiation from the shaft end part of the heat roll 1 to the outside of the fixing device is suppressed considerably by the heat insulating effect of an insulating layer 7 because the shaft end part of the heat roll 1 is supported on a bearing 3 through the insulating layer 7, and thus, the temperature distribution in the axial direction on the surface of the heat roll is kept uniform practically. |
