| 摘要 |
PROBLEM TO BE SOLVED: To provide a collector of small size, having a partially pyramid or partially cone shaped collector main body that efficiently collects a luminous flux incident onto an indent plane at an emitting plane efficiently, where a wide incident plane can be obtained with respect to length of the collector so as to attain efficient light concentration. SOLUTION: This collector has a transparent collector main body 11, an incident plane 12 formed to one end of the collector main body 11 and receiving an incident light, an emitting plane 13 formed opposite to the incident plane 12 at the other end of the collector main body 11 and emitting a light, and a reflection plane 14 that is formed on a side face or a circumferential face of the collector main body 11, tapered to narrow the opposite interval toward the emission plane 13 from the incident plane 12 and reflects a light propagated in the collector main body 11 from the incident plane 12 to the emission plane 13. A value for α=21×tanβ(i+o) is set at 0.7-1.3, where β is taper angle of the reflection plane 14, l is distance between the incident plane 12 and the emission plane 13 of the condenser main body 11, i is a width of the incident plane 12 and o is a width of the emission plane. |
