| 摘要 |
PROBLEM TO BE SOLVED: To suppress luminance unevenness on an emission surface even when viewed from various positions and angles including a wide-angle range with respect to a downward direction of a light source, in a luminaire.SOLUTION: A luminaire 1 includes: a plurality of light sources 2; and a flat plate-like light diffusion member 3 arranged so as to face the light sources 2. In the light diffusion member 3, a surface facing the light sources 2 is made to be an incident surface 30A and the opposite side surface is made to be an emission surface 30B, and the light diffusion member 3 includes a plurality of prisms 31 having two or more of optical surfaces 32A, 32B. The prisms 31 constitute a prism group 33 with each of the light sources 2 being a center. The prism group 33 includes a total reflection prism 31R in which an angle α formed by a normal line H1 of the optical surface in which distance from the light source 2 is the farthest out of the optical surfaces 32A, 32B, and a normal line H2 of the incident surface 30A satisfies nsinα≥1 (n is a refractive index of the light diffusion member), and the ratio of the total reflection prism 31R increases as the distance from the light source 2 becomes farther away. |
