EXPOSURE DEVICE OF ELECTROPHOTOGRAPHIC COPIER

摘要

PURPOSE:To control exposure intensity properly according to the stains of photoreceptor surface by conducting the reflected light from the photoreceptor to a photodetector and comparing the same with a reference value. CONSTITUTION:In an exposure system for electrophotographic copiers, the light from a light source 10 is projected to an original 4, and the reflected light enters a photoreceptor 2 via a focusing type optical transmission body 15. The light from the light source 10 is also entered to the reference reflection plate 30 of an original platen 3, and the reflected light thereof enters the photoreceptor 2 via the optical transmission body 15 and also the reflected light of the photoreceptor 2 enters a photodetector 27. The output of this photoreceptor 27 is compared with a reference value, thus the output of the light source 10 is controlled to a proper value according to the stains of the photoreceptor surface.