Patent ID: 7866844

Claim:
An emission device comprising: a light emitting element, a substrate for mounting said light emitting element and a light flux control member through which light of said light emitting element is outputted, wherein said light flux control member has a light control emission face controlling light outputting and a back face which is opposite to and in contact with said substrate, said back face being provided with a first recess portion which has an opening edge and is formed at a location corresponding to said light emitting element as to taking light of said light emitting element into said light flux control member and at least two ventilation grooves which provides a sink extending from said first recess portion radially outward along said back face so that said first recess portion communicates with ambiance, and, said light control emission face being configured as to meet a condition at least regarding light emitted in a direction range which is within 75° from a maximum intensity light emission direction of said light emitting element, said condition being that increasing quantity of θ 5 relative to increasing quantity of θ1, Δθ5/Δθ1 is larger for light in an angle region near to the reference optical axis as compared with Δθ5/Δθ1 for light in an angle region remote from the reference optical axis, under definition such that θ1 is angle of a travelling direction of light within said direction range, on reaching a reaching point on said light control emission face after incidence to said light flux control member, with respect to a line parallel with a reference optical axis of said emission device and emission angle θ5 is angle of emission from said light control emission face.