| 摘要 |
PROBLEM TO BE SOLVED: To lessen the color change according to a change in a horizontal visual field angle and to improve uniformity by specifying the exit intensity ratio of the respective incident rays on lenticular lenses in such a manner that the ratio satisfies specific conditions. SOLUTION: The lenticular lenses are provided with incident side lenses 3 on the side near a light source and exit side lenses 4 and light absorption bands 5 on an observer side and such shapes are repetitively molded in a horizontal direction. Parallel beams are made incident respectively at horizontal incident angles 0 deg., -11 deg. and +11 deg. on the incident side lens 3 face. The exit intensity of the respective rays at the horizontal visual field angle 0 deg. on the exist side is defined as 1 and the exit intensities of the respective rays at the horizontal visual field angleθH deg. are respective defined as I0 (θH), I-11 (θH) and I+11 (θH). In such a case, 0.30<=|I0 (θH)|<=0.36 is satisfied when|θH|<=40 deg. is set in the equation i0 (θH)=I0 (θH)/(I0 (θH)+I-11 (θH)+I+11 (θH)).
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