Patent ID: 7621657
Filing Date: 2009-11-24
Classification: G02B

Abstract:
1. A light emitting device comprising: a light flux control member via which light from a light emitting element is emitted, wherein said light flux control member has a recess and an emission control face, said recess being arranged corresponding to said light emitting element and provides a light input portion for causing light emitted from said light emitting element to be inputted into said light flux control member, and said emission control face causing light inputted into said light flux control member to be outputted after inner propagation, and said emission control face is configured so that a projection image of said emission control face onto an imaginary plane perpendicular to a datum optical axis of said light emitting device provides a planar outline shape anisotropic around said datum optical axis, and so that the following Conditions 1 to 3 are satisfied, Condition 1 is that a relation of (θ5/θ1)>1 is satisfied except for light of directions angularly near to a direction of said datum optical axis, Condition 2 is that the value of θ5/θ1(>1) according to the above Condition 1 gets smaller gradually with increasing of θ1, Condition 3 is that the value of θ5/θ1(>1) according to the above Condition 1 shows dependency on direction around said datum optical axis, where θ1 is an angle made by an inner incident light to said emission control face on inner incidence with respect to a line which passes a position of said inner incidence and is parallel to said datum optical axis of said light emitting device, and θ5 is angle made by said inner incident light with respect to said line on being emitted from said emission control face.