Patent ID: 8308309

Claim:
A lighting device comprising: a light source which emits light around a light source axis; a reflector which has a plurality of reflection surfaces for reflecting light emitted from the light source; a plurality of converging units each of which is provided for a corresponding reflection surface of the plurality of reflection surfaces to receive light released from the corresponding reflection surface; and a stacking system which stacks light having passed the plurality of converging units on a light receiving area, wherein: each of the plurality of reflection surfaces is formed by a part of a spheroid having focuses at a position of the corresponding converging unit and a position of the light source, and a focal distance of each of the plurality of converging units becomes longer as a distance between the position of the converging unit and a corresponding point of the light source axis increases, a line connecting the position of the converging unit and the corresponding point of the light source axis being perpendicular to the light source axis.