| 摘要 |
PROBLEM TO BE SOLVED: To provide a light guide where a dark part does not appear accompanying the reduction of luminance in the neighborhood of a corner part positioned on the light incident surface side on a light emission surface and which is excellent in the uniformity of luminance on the whole light emission surface, and to provide its manufacturing method and a surface light source unit using the light guide. SOLUTION: In the light guide for the surface light source unit, at least one side end surface is adopted as the light incident surface 2 and one of two opposing main surface is adopted as the light emission surface 3. A first area A with an average inclination angle which is larger than that in any other part is formed in the neighborhood of at least one angle positioned at the side of the light incident surface 2 on at least one of the main surfaces of the light emission surface 3 and its rear surface 4. |
