| 摘要 |
PROBLEM TO BE SOLVED: To provide a transparent material in which leakage light from a side end surface where no light source is arranged can be made less, an efficiency for light utilization can be made high and no irregular light-dark state occurs.SOLUTION: This invention relates to a transparent material 10 comprising a lenticular lens 17 as a light deflection element, the lenticular lens has either a concave surface or a convex surface as seen from its sectional view, its surface satisfies a relation of 0.1 μm≤Ra≤1.0 μm, where Ra is a local arithmetic average roughness, its surface satisfies a relation of 5 μm≤h≤25 μm, where emission plane 10b is an upper side, a light deflection plane 10a is a lower side and (h) is a vertical height, its surface satisfies a relation of 10 μm≤h-h≤20 μm, where his the maximum height of (h) over an entire range in an extending direction of the lenticular lens and his the minimum height, and its surface satisfies a relation of 100 μm≤λ≤1000 μm, where λ is a distance between summits of adjoining apexes when the height (h) changes periodically in the extending direction of the lenticular lens. |
