| 摘要 |
PROBLEM TO BE SOLVED: To obtain bright and uniform exit light by which a light source is not reflected and dark areas are not brought about even in both ends of an incidence end face around the incidence end face. SOLUTION: A light guide plate 2 is configured to have backside portions 7a and 7b having respective inclines of a single slope from incidence end faces 3a and 3b to a central portion between the two incidence end faces 3a and 3b so that a distance between a surface 6 and the backside portions 7a, 7b is minimum at the incidence end faces 3a and 3b and is maximum at the central portion. Light rays incident upon the incidence end faces 3a and 3b do not exceed a critical angle when traveling in a direction away from the incidence end faces 3a and 3b until the central portion, exceed a critical angle when then traveling to the mutual incidence end faces 3a and 3b past the central portion, do not exceed a critical angle when subsequently traveling to the central portion after being reflected on the mutual incidence end faces 3a and 3b, and exceed a critical angle and bring about their output when thereafter traveling back to the incidence end faces 3a and 3b past the central portion. COPYRIGHT: (C)2007,JPO&INPIT |
