| 摘要 |
PURPOSE:To achieve efficient illumination by deciding the position, where reflected light from an upper reflecting mirror among columnar reflecting mirrors which is laid out on the side of a part to be lighted while keeping a tubular light source as a center, can attain maximum illuminance, more closely to the center of an optical path than to an auxiliary reflecting mirror. CONSTITUTION:A tubular light source 5 consists of a partially covered columnar main reflecting mirror and a plane auxiliary reflecting mirror 12, and the main reflecting mirror 11 consists of an upper reflecting mirror 11a, a lower reflecting mirror 11b, and a back reflecting mirror 11c for connecting them together. The shape of the part of the main reflecting mirror 11 on the side of stage glass 11 is part of an elliptic column which has a focal point at the axial center F1 of the tubular light source 5 and also has a focal point F2 halfway to the part 4 to be lighted on the stage glass 1. Consequently, a beam 13 of light reflected at the closest part of the upper reflecting mirror 11a to the tubular light source reaches the part 4 to be lighted which is closer to the auxiliary reflecting mirror 12 than to the optical path center 8, and a beam 14 of light reflected at the closest distance to the tubular light source by the lower reflecting mirror 11b reaches the part 4 to be lighted which is closer to the light source than to the optical path center 8. |
