| 摘要 |
PURPOSE:To maintain a stable image by providing aperture limiting means which measure the axial potential of a photosensitive body by a sensor and varies the quantity of exposure according to the measurement result, on the optical path of a light beam. CONSTITUTION:The sensor 3 which measures the surface potential of the photosensitive body 1 is provided and measures the potential of the photosensitive body 1 in the axial direction A and the aperture limiting means 34 and 35 which vary the quantity of exposure of each position to a light beam according to the measurement results at respective positions of the photosensitive body 1 are provided on the optical path of the light beam. The aperture limiting means 34 and 35 are arms and form a slit for light quantity limitation at the part of dust-proof glass 11 on the optical path of the light beam. Consequently, stable image forming operation is performed irrelevantly to the generation of a potential difference between positions of the photosensitive body 1 in the axial direction A. |
