| 摘要 |
PURPOSE:To make a light quantity distribution constant on the image forming surface of a copying machine exposing system, no matter how a copying magnification is varied, by rotating a cylindrical slit member in accordance with variation of the copying magnification, forming a sectional shape of a slit-like optical path in the shape of a drum, and varying it. CONSTITUTION:When an exposing system is set to a necessary copying magnification by a copying magnification setting mechanism, the second and the third mirrors 7, 8 and a lens 10 are moved to a prescribed position, also by interlocking with it, a cylindrical slit member 15 is driven to rotate suitably, becomes a constant value by the width of an image forming side slit formed by its bus 18 and a u-shaped slit member inside edge 20, a light quantity distribution immediately before an image forming side slit part 14, and a light quantity distribution in case when the product has passed through the image forming side slit part 14, and becomes constant irrespective of a distance to a lens optical axis on the image forming surface and a copying magnification M. In this way, light can be irradiated uniformly to the surface of a photosensitive body which is an image forming surface of the exposing system, and a copy of good quality can be obtained. |
