| 摘要 |
PURPOSE:To form a direct heating type heat fixing device where electric conduction to a resistance heating body is possible by extending a resistance heating body layer up to the shaft end part of a metallic core and connecting a voltage source between an electrode provided on the surface of the resistance heating body layer in the shaft end part and the metallic 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 impressed to feeding brushes 14 and 14', a current is flowed to a resistance heating body layer 8 through an electrode film 9 and a hollow core 5. 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 1 and the pressure roll 2 to obtain a fixed image. By this heating device, one electrode can be omitted because it is used as an electrode of the hollow core 5 of the heat roll 1, and the feeding mechanism is simplified. Further, since the resistance heating body layer 8 extends to the range of the hollow core 5, the fall of temperature in both end parts of the roll is prevented to make the tempeature distribution in the axial direction on the surface of the heat roll uniform practically. |
