| 摘要 |
PURPOSE:To utilize luminous flux effectively by guiding rectangular luminous flux emitted by a light source to a lighting system through an optical conversion system which is different in the conversion ratio of luminous flux shape size on a section containing the optical axis and a section perpendicular to it, and irradiating an object surface. CONSTITUTION:When the focal lengths of the 1st and the 2nd lenses are denoted as f1 and f2 and the interval between their principal points if denoted as l, an arrangement is so made that f1+f2 is nearly equal to l. The luminous flux from an excimer laser 1 is in such a shape that its size is (b) in the direction of a section H and (a) (>b) in the direction of a section V perpendicular to the section H. At this time, when the luminous flux is diverged by the 1st lens 21 in the direction of the section H and travels by the distance l, the refracting power and distance l of the 1st lens 21 are so set that the luminous flux size in the section H is the luminous flux size (a) of the section V. Then, the luminous flux is shaped to the luminous flux size (a) in the section H and then converged by the 2nd lens L and the luminous flux sizes in the sections H and V are both (a), so that parallel luminous flux is projected. At this time, the refracting power values of the 1st and the 2nd lenses are so set that af1+bf2=0 holds.
|
