| 主权项 |
1. A surface light source apparatus comprising:
a light emitting element that emits light; a light flux controlling member that controls light emitted from a light emitting element; and a light diffusing member that scatters light and allows transmission of light emitted from the light emitting apparatus, wherein the light flux controlling member comprises:
a light control/emission surface that controls a traveling direction of the light emitted from the light emitting element;a concavity that allows a main beam to be incident inside, the main beam being light emitted in a predetermined range of an angle from a reference optical axis serving as a center axis of three-dimensional light fluxes emitted from the light emitting element; anda back surface that extends in a radial direction from an opening rim part of the concavity and that allows sub-beams to be incident inside, the sub-beams being light other than the main beam emitted from the light emitting element, wherein one of a grid convex part which arranges a plurality of strips of convex parts in a grid pattern and a grid concave part which arranges a plurality of strips of concave parts in a grid pattern, is formed in the back surface of the light flux controlling member, and wherein surface roughening treatment is applied to one of the strips of the convex parts and the strips of the concave parts. |
