| 摘要 |
PCT No. PCT/JP86/00489 Sec. 371 Date May 18, 1987 Sec. 102(e) Date May 18, 1987 PCT Filed Sep. 19, 1986 PCT Pub. No. WO87/01816 PCT Pub. Date Mar. 26, 1987.When light rays (L1, L2) from any arbitrary directions arrive at the surface of incidence (3) at one end of a main body (2) made of a transparent glass or plastic, they are successively totally reflected internally by opposite reflecting surfaces (5a, 5b) of the main body (2) such that an angle formed between each light ray and the perpendicular to the reflecting surface gradually approaches to a critical angle delta 0 and the light rays are taken out of the main body through light emerging surfaces (5a, 5b, 4). The light rays taken out of the main body (2) through the light emerging surfaces are given greater components in directions parallel to the longitudinal direction of the main body (2) than the incident light rays (L1, L2). Therefore, light rays from all directions, incident to the surface of incidence (3), after being caused to pass through the main body (2), are given substantially equal directivities. Typically, the main body (2) is in the form of a wedge-shaped plate, a cone or a polyhedron. In practical use, a plurality of main bodies (2) are arranged in a parallel array to form a board-like assembly whose one surface is used as a light incidence surface. |
