| 摘要 |
<p>This apparatus comprises a light entrance surface, a diffused light exit surface, and a diffused light guide of a volume area having a uniform diffusing power. The value E [cm<-><1>], of the effective diffusion illumination parameter of the guide is 0.45 </= E </= 100. In the correlation functional approximate expression, (r) = exp [-r/a], expressing the uneven refractive index structure of the guide, the correlation distance a is 0.01 mu m </= a </= 50 mu m. No diffusing layer of diffusive ink need to be formed on the back side of the guide. When an element for correcting the direction of the light outgoing from the light exit light surface, having a serrated surface is provided on the light exit surface, it is possible to increase the light traveling in a specific direction. The uneven refractive index structure can be produced by kneading a polymer matrix and a granular material having a different refraction index, by kneading two or more polymers having different refractive indecies, or by dispersing a granular material by suspension polymerization. The material having such a structure is then molded and used as the guide. <IMAGE></p> |
