| 摘要 |
PROBLEM TO BE SOLVED: To obtain an illumination device capable of brightly displaying picture based on a picture display device on a prescribed surface (screen surface). SOLUTION: This illumination device is provided with a light source 1 arranged at the focal position of a condensing reflection mirror 2, a 1st lens array 3 where plural lenses for condensing luminous flux radiated on the light source 1 and reflected on the mirror 2 are two-dimensionally arranged, a 2nd lens array 4 where plural lenses arranged near the focal position of the array 3 are two-dimensionally arranged, and lens systems 6 and 7 for illuminating the surface to be irradiated 8 with the luminous flux from the array 4. Then, when the expression of K1=(Larc×fryf1/2fm)/(Lfry2p/2) is attained [provided that Larc is the length of the light emission part of the light source 1 in an optical axis direction, (fryf1) is the focal distance of the array 3, (fm) is the focal distance of the mirror 2 and (Lfry2p) is the length of the array 4 in the long-side direction of one frame], the expression of 0.7<K1<1.3 is satisfied. |
