| 摘要 |
PURPOSE:To correct illuminance over a wide range without any abrupt change in light shielding effect by scanning a light shielding plate for correcting illuminance irregularity integrally with a lens. CONSTITUTION:A lens scanning system which forms original images on a drum 3 from one edge part A of the original to the other edge part C is constituted of a movable lens 2 and a photosensitive drum 3. In this optical system, a light shielding plate 6 is disposed with slight deviation by a distance (h) toward the original from the incident pupil position of the lens 2. The plate 6 is designed to move integrally with the lens 2. A method of providing the plate 6 in one body with the holding member of the lens 2 or the like is used for a means of moving the plate 6 intergrally with the lens 2. With such arrangement, the abrupt change in the light shielding effect in accordance with the scanning of the lens is prevented, and illuminance is corrected over a wide range. |
