LIGHT GUIDE AND GUARDRAIL STRUCTURE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a light guide which has a high uniformity ratio of illuminance of just under illumination on an irradiation surface. SOLUTION: In this light guide in which a diffuse reflection material 2 is arranged at one part of a side surface of a light guiding member 1 along an axial direction and which performs surface light emission with light A that is made incident from an end part of the light guiding member 1 and emitted from a light source, at least a transparent member 3 whose refractive index is lower than that of the light guiding member 1 is disposed in close contact with the light guiding member 1 and the diffuse reflection material 2 between the light guiding member 1 and the diffuse reflection material 2. Incident luminous fluxes to the diffuse reflection material 2 per unit length are averaged and the uniformity ratio of illuminance of an illumination distribution of an irradiation surface is improved by reducing incident components to the diffuse reflection material 2 particularly in the vicinity of a side end part of the light source and also improving the light guiding efficiency of the light guide. It is also possible to provide the long light guide with a high uniformity ratio of illuminance by improving light guiding efficiency.