| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical element capable of efficiently emitting light incident in a predetermined angular range in a predetermined angular range, and to provide a manufacturing method of the same, a luminaire, window material and a fixture.SOLUTION: An optical element includes: a first surface S1; a second surface S2 facing the first surface; and a plurality of reflection surfaces 151r aligned inside a first region defined by the first surface and the second surface. The plurality of reflection surfaces have a first length d in a first direction perpendicular to the first surface, and are arrayed along a second direction orthogonal to the first direction. Light entering one surface of the first surface and the second surface is reflected toward the other surface by the plurality of reflection surfaces. The optical element satisfies a conditional expression related to first length, the number of total reflection, an array pitch p of the reflection surfaces, an angle formed between a projection to a plane including the first and second directions of light entering the reflection surface and a tangential line at any point on the reflection surface, a refractive index inside the region defined by the first surface and the second surface, and the like. |
