SURFACE LIGHT SOURCE DEVICE, DISPLAY DEVICE, AND LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a surface light source device capable of making brightness distribution uniform.SOLUTION: A surface light source device 1 according to the present invention comprises: a light source 6 including a light emitting element 7 and a concave surface mirror 9 reflecting light emitted from the light emitting element 7; and a light guide body 3 on which the light emitted from the light source 6 is incident from an end face 3a, and that emits the light from a principal plane 3b while the light is propagated inside. The concave surface mirror 9 at least partially has such a curve shape that a cross sectional shape when being cut into a plane parallel to the principal plane 3b of the light guide body 3 has a focal point. The light emitting element 7 is arranged so that the focal point is positioned on a light emitting surface 7a, and is configured so that the light from the light emitting element 7 is incident on the light guide body 3 via the concave surface mirror 9. The light emitting element 7 is arranged outside the light guide body 3 when seen in a normal direction of the light emitting surface 7a.