| 摘要 |
PURPOSE:To prevent generation of optical distortion to form always good images by allowing an optical system and a developing system to follow up a sheet-shaped photosensitive body in accordance with the quantity of winding of this photosensitive body to make the optical path length constant independently of variance of the quantity of winding. CONSTITUTION:A developing device body 61 is brought into contact with a photosensitive sheet 47 on a take-up drum 43 for image formation through a pair of rollers 73 by the charging force of a spring 69. An optical focusing device 75 is pressed to the side of the drum 43 through a roller 85 with a reflection point 83 on a reflective mirror 77 as the fulcrum by the charging force of a spring 87. Consequently, though the outside shape of the drum 43 is changed by variance of the number of turns of the photosensitive sheet 47, the interval between the developing device 61 as well as the optical system 75 and the photosensitive sheet 47 is kept constant because the developing device 61 and the optical system 75 are moved in accordance with this change of the outside shape. Thus, the optical path length is constant independently of variance of the quantity of winding, and generation of optical distortion is prevented to form always good images. |
