| 摘要 |
PROBLEM TO BE SOLVED: To provide ultra-fine rod-like transparent material enabling a generated dark line to be disappeared for attaining a direct lighting by making at least a part of longitudinal section of the transparent material into an arcuate shape or narrowing a spacing of a plurality of pattern grooves (recesses) formed at a reflection surface of the transparent material in order to extend an irradiation distance of light outgoing from a light-emitting face of the transparent material.SOLUTION: This invention relates to transparent material 3 for guiding light 12 incident from a longitudinal end incident face. One of the side surfaces of the transparent material 3 is formed with a planar reflection surface 3b and the other side surface opposing against a reflection surface 3b is formed with a light-emitting surface 3a of arcuate section. A plurality of recesses 3e are arranged and spaced apart along a longitudinal direction at a central region spaced apart from the side end part in a width direction of the reflection surface 3b, and at the same time, forming positions in width direction of the adjoining recesses 3e are set to be staggered. |
