| 摘要 |
PROBLEM TO BE SOLVED: To reduce the thickness of an electrical conductive elastic layer in the radial direction and to maintain positional relation between a photoreceptor and a regulation blade within a fixed range without being affected by environmental change such as temperature or humidity though a developing roller is provided with the electrical conductive elastic layer by using an electrical conductive resin layer for a core body part supporting the electrical conductive elastic layer. SOLUTION: The developing roller 1 adopting a non-magnetic one-component system is mainly constituted of the electrical conductive elastic layer 2 and the core body part 5 supporting it. Besides, a surface protection layer 6 whose thickness is 10 to 150μm is formed on the layer 2. The roller 1 is constituted so that the diameter of the core body part 5 is made large, the thickness of the layer 2 in the radial direction is reduced within such a range that an elastic effect can be maintained and the electrical conductive resin layer 3 is used for the core body part 5. Since the diameter of the core body part 5 is made large by using the resin layer 3 whose coefficient of linear expansion and percentage of water absorption are small in comparison with the layer 2 and the thickness of the layer 3 in the radial direction can be reduced, the change of the outside diameter of the roller caused by the environmental change such as the temperature or the humidity can be suppressed. |
