| 摘要 |
PROBLEM TO BE SOLVED: To prevent the use efficiency of illumination light from decreasing even if a projection surface side is trimmed by forming a light reflection surface which reflects the illumination light corresponding to the trimming of the projection surface side on a plate member side of trimming. SOLUTION: A protection sheet 21 is formed by sticking a silver tape 21B which reflects illumination light with good efficiency on a light absorption layer on the side of a light guide plate 6, and this silver tape 21B forms a light reflecting surface which reflects the illumination light. Consequently, the side light type surface light source device reflects the illumination light reaching a light shield surface toward the light guide plate 6 by the light reflecting surface and the light guide plate 6 reuses it. This light reflecting surface is made narrower than the light shield surface and formed so that the outer peripheral side meets the outer peripheral side of the light shield surface. Consequently, the protection sheet 21 has the light shield surface exposed to the light guide plate 6 at the inside part of trimming. Then excessive projection light is absorbed to evade luminance unevenness of projection light. |
