| 摘要 |
PROBLEM TO BE SOLVED: To provide an excellent Fresnel lens free from a blurred image or color irregularity by suppressing exiting of internally reflected light from a segment non-lens face. SOLUTION: Each lens segment 1 of the Fresnel lens has a segment lens face 12 having the lens effect and a segment non-lens face 13 having no lens effect. The segment non-lens face 13 is a rugged face having a sawtooth cross section with 80 to 100°apex angles. The segment non-lens face 13 repeatedly reflects the internal light by the similar effect to that obtained by tightly arranging small corner cubes. Therefore, exiting of the internal reflection light from the segment non-lens face 13 is suppressed. The rugged face may be altered into a curved face or a structure similar to a lenticular lens as required. COPYRIGHT: (C)2003,JPO
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