To provide a lens for illumination capable of enlarging the directivity of a light source.
This lens 1 for illumination includes an incident surface 11 and an outgoing surface 12. The outgoing surface 12 includes a first outgoing surface 121 projecting toward the vertex on the optical axis A, and a second outgoing surface 122 enlarging from the rim of the first outgoing surface 121 to the outside. The first outgoing surface 121 has a shape that totally reflects, at a first arrival point at which the radiation light arrives first, the radiation light arriving at a point on the first outgoing surface 121 where θi establishes a predetermined angle or larger, in which the angle formed between the line connecting the point on the first outgoing surface 121 to a base point P and the optical axis A is assumed to be θi, of radiation light radiated from the base point P as the light source position on the optical axis A and arriving at the first outgoing surface 121, and refracts the totally reflected radiation light at a second arrival point to make it arrive at the surface to be irradiated. The second outgoing surface 122 has a shape that refracts the radiation light radiated from the base point P and arriving at the second outgoing surface 122 at the arrival point to make it arrive at the surface 3 to be irradiated.
KIMURA SHUNSUKE
MATSUKI DAIZABURO
Keiko Manaka