| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device capable of attaining a uniform emission quantity of light in a longitudinal direction even if a light guide element has a long shape, exhibiting an appropriate illumination effect, and ensuring excellent user-friendliness.SOLUTION: A lighting device 2 includes: a light guide element 6 having a long shape, including an incident surface 3 on an end, and including an output surface 4 and a reflection surface 5 on an outer peripheral surface in a longitudinal direction; and a light source 7 arranged opposed to the incident surface 3 of the light guide element 6, a diffusion section 8 being provided on the reflection surface 5, the diffusion section 8 having a long shape extending from the incident surface 3 in a direction of being away from this incident surface 3, and a width of the diffusion section 8 in a direction orthogonal to the extension direction being gradually increased from the incident side 3 in the extension direction. |
