JPS6417040A - Scanning exposure type copying machine - Google Patents

Abstract

PURPOSE:To prevent the formation of a noise image caused by miscellaneous light and to improve the image quality of a copied image by applying a reflected light preventing film on at least one surface of the surface opposite to the original placing surface of an original platen glass, the surface of a filter on the same side as the above-mentioned surface and the surface of a Fresnel lens facing the original platen glass. CONSTITUTION:The reflection preventing films a1 and a2 are vapor-deposited on the surfaces of the cylindrical Fresnel lenses 131 and 132 facing an exposure lamp 4. In the same way, the reflection preventing films (b) and (c) are respectively vapor-deposited on the original platen glass 2 and the filter 133 which is sometimes provided on the bottom part of the original platen. Then, the radiated light from the exposure lamp 4 of the exposure optical system 3 of a scanning exposure type copying machine 1 is reflected by the reflection preventing films coated on the filter 133, the original platen glass 2 and the respective surfaces of the cylindrical Fresnel lenses 131 and 132 facing the exposure lamp 4, so that it does not enter the optical system 3. Thus, the formation of the noise image caused by the miscellaneous light can be prevented and the distinct copied image of good quality can be obtained.