FRESNEL LENS, ITS MOLDING DIE AND MANUFACTURING METHOD, AND TRANSMISSION TYPE SCREEN USING FRESNEL LENS

摘要

PROBLEM TO BE SOLVED: To provide a Fresnel lens and the like that can be easily released from a molding die when manufactured using the molding die and that hardly causes stray light in use. SOLUTION: This is a Fresnel lens 1 equipped on the light incident area with a plurality of prisms 2 having a refractive face 3 for refracting incident light and a total reflecting face 4 for totally reflecting the light refracted on the refractive face 3. The plurality of prisms 2 are formed by bending, to the other prism 2B, the valley part 5 which is formed of the refractive face 3 of one prism 2A and of the total reflecting face 4 of the other prism 2B adjacent to the refractive face 3 of the one prism 2A. COPYRIGHT: (C)2004,JPO&NCIPI