| 摘要 |
PURPOSE:To improve contrast and durability by setting the ten-point average roughness of the dielectric layer of an image holding member to a specific value. CONSTITUTION:An electrode 4 is disposed in such a way that it is oppositely isolated from the image holding member 5, magnetically conductive developer 1 is attracted to the electrode 4 by means of magnetism, and a voltage is applied between the electrode 4 and the image holding member 5, thereby attaching a developer 1 to the image holding member 5. The image holding member 5 consists of a conductive mast supporting plate 7 (conductive layer), a diffusing reflection layer 6a, and a dielectric layer 6b all of which are stuck together, the layer 6a being formed by dispersing reflecting grains in resin. The ten-point average roughness of the layer 6b is set to 0.1-5.0mum. Since highly insulating space is created between the layer 6b and the developer 1, an electric charge is prevented from being ejected into the layer 6b and the developer 1 is not taken into the minutely uneven surface. This improves contrast, the environmental characteristic, and durability. |
