| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device which is enabled to irradiate light with a practically big solid angle and enabled to improve the utilizing efficiency of a flux of a light source. SOLUTION: A luminous flux reflected by an ellipsoidal surface mirror of a reflector 1 travels toward a second focus F2 through a window 5 of a front mirror 4, and the luminous flux emitted from a light source 2 and reflected by the front mirror 4, and the flux emitted from a light source 2, reflected by the ellipsoidal surface mirror 1, and reflected by the front mirror 4, are enabled to travel toward the second focus F2 through the window 5 of the front mirror 4. The solid angle θ is enabled to practically become big only by prescribing the size of the window 5 of the front mirror 4, and almost whole part of the luminous flux of the light source is enabled to efficiently utilize. |
