EXPOSURE LENS AND ITS MANUFACTURE

PROBLEM TO BE SOLVED: To prevent a yellowing phenomenon of discoloration caused by ultraviolet rays emitted by a light source in exposing operation and prevent the life of an exposure lens from becoming short as much as possible by providing a means which suppresses the transmission of ultraviolet rays having a wavelength below of a specifier wavelength or smaller. SOLUTION: The exposure lens has a block lens 31 which is formed by combining respective block cells 31a through injection molding or press machining and has a diffusing function. This block lens 31 is made of PMMA(Poly Methyl Methacrylate). This exposure lens is composed by fitting an ultraviolet- ray suppression member 33 which is formed to have a specified thickness on the lower end surface of the block lens 31. This ultraviolet-ray suppression member 33 suppresses or cuts off ultraviolet rays of