| 摘要 |
PURPOSE:To easily and accurately hold a development gap constant by mounting annular electric insulating spacer members on the outer peripheral surfaces of a photosensitive drum at the outside of both ends of an image formation position, and pressing them against the outer peripheral surface of a developing roller. CONSTITUTION:The spacer members 14 are provided directly to the outer peripheral surfaces 12 of the photosensitive drum 11. Therefore, even if the photosensitive drum 11 or developing roller 16 itself vibrates, the development gap is hardly affected by the vibration and a variation in development gap is caused only by the thickness irregularity of the spacer members 14, which are manufactured only with uniform thickness. Consequently, the development gap can be set easily, permanently, and stably at low cost. |
