| 摘要 |
PURPOSE:To keep a developing gap constant by providing directly a ring-shaped spacer member on one of a photosensitive drum or a developing roller, in a position of the outside of both ends of an image forming position of the photosensitive drum, and pressing this spacer member against the outside peripheral surface of the other side. CONSTITUTION:At the time of development, the outside periphery of a developing roller 4 is pressed against a ring-shaped spacer member 10, and a developing gap (strictly speaking, it is different by a size difference of the outside surface of a photosensitive layer and the outside surface of both ends of a conductive base body) of only a portion prescribed by thickness of the ring-shaped spacer member 10 is held between the photosensitive layer 3 and the developing roller 4. In this state, by a rotation of the developing roller 4, a toner on its outside peripheral surface is supplied to a photosensitive drum 1. As for the ring-shaped spacer member 10 which is used in this case, a resin film which has been formed endlessly, for instance, an endless polyester film is suitable. |
