| 摘要 |
PROBLEM TO BE SOLVED: To provide an annular lighting system that realizes a uniform annular illumination effect with a minimum light source. SOLUTION: This annular lighting system is equipped with an annular light guiding plate 1 and a light source 2 illuminating from its back side, and thus illuminates annularly. The annular light guiding plate 1 is equipped with a light guiding hole 7 composed of a surface 1a that is vertical and parallel to its normal direction and a projecting surface 1b formed on its outer circumferential edge at a certain angle, and a light guiding surface 1c that is tilted in the circumferential direction so as to reflect the incident light from the light guiding hole 7 formed on the back side of the annular light guiding plate 1. The projecting surface 1b of the light guiding hole 7 is formed protrusively more than the periphery of the annular light guiding plate 1 and uneven parts are formed on the light guiding surface 1c; the light source 2 is structure so as to face the projecting surface 1b of the light guiding hole 7 and to be placed out of the projecting range of the light guiding surface 1c. |
