| 摘要 |
A light flux control member has a back face provided with a recess and a ring-like-recess-portion surrounding the recess. Output light of a point-like-light-source (light emission element) is incident to the recess and the ring - like - recess - portion. Incident light to the recess is emitted from a light control emission face after inner-propagation. Incident light to the ring - like - recess - portion is refracted as to hardly generate inner - propagation light deflected to directions near to a direction of reference optical axis L, resulting in outgoing from any part of the light control emission face, or, if some outgoing occurs from the light control emission face, such outgoing occurs only at an outer periphery portion of the light control emission face. As a result, illumination light quality is avoided from being reduced by appearance of conspicuous ring-like bright part. In addition, uniform illumination light can be supplied to a broad angle range. Even if a plurality of point - like - light - sources are arranged at intervals, respective light fluxes originated from respective point - like - light - sources are well mixed. |
