To provide a lighting device or the like, which has a miniaturized structure and which makes the illumination light efficiently propagate in a prescribed direction within a prescribed angular range.
The lighting device has a light emission part 201 consisting of a solid state light emitting element and supplying the illumination light, a reflector 210 of an approximately elliptical shape for reflecting the illumination light, a collimator lens 220 for collimating and emitting the illumination light, and an auxiliary reflector 230 of an approximately spherical shape for reflecting the illumination light from the light emission part 201 in the direction of the reflector 210, in which the light-emitting central position of the light emitting part 201, the first focal position of the reflector 210, the front-side focal position of the collimator lens 220, and the curvature central position of the auxiliary reflector 230 approximately coincides with a position P1, and in which the second focal position of the reflector 210 and the position of the front-side principal point of the collimator lens 220 approximately agree at a position P2.
TAKEDA TAKASHI
Fujitsuna Hideyoshi
Osamu Suzawa