| 摘要 |
<p>PURPOSE:To improve the light quantity distribution and the utilization efficiency of light by returning light which is emitted by the light source and reflected by a submirror to the, light source and setting the focus of a main mirror and the light source at different positions. CONSTITUTION:When an elliptic mirror as a main mirror 11 and an annular spherical mirror as a submirror 13 are used, the center light emission part 12c of the light source 12 is positioned in the spherical center Or of the submirror 13. The main mirror 11 has a 1st focus f1 and a 2nd focus f2 and the 1st focus f1 and the center light emission part 12c of the light source 12 are offset in the direction of the optical axis O of lighting without being aligned with each other. The offset quantity (a) and its direction are set by simulation corresponding to elements such as the shape of the main mirror 11 and the size of the light source 12. Namely, the light which is emitted by the light source light emission part 12c and reflected by the submirror 13 returns to the light source light emission part 12c, so the light reflected by the submirror 13 can be returned to the main mirror 11 without increasing the size of the light source 12 substantially. The focus f1 of the main mirror 11 is offset from the light source light emission part (spherical center of submirror) 12c, so an illuminance distribution which is free from center absence is obtained.</p> |
