| 摘要 |
PURPOSE: To uniformly radiate light windows at an output side by positioning a structural surface having a plurality of prisms at the upper part in an optical cavity, deciding one surface at the top part, and allowing at least one part to make an acute angle against a collimation adjusted axial line. CONSTITUTION: An optical cavity constituted of wall parts 10 and 12 is provided with a light window provided with a light transmitting member 14 inside, and a partially collimation adjusted light source 16 is positioned adjacent to a side part 10 of a housing inside the optical cavity. A side part 22 of the wall part 12 is the surface of a structure having a plurality of preferably triangular prisms 24 at the upper part, and a light from the light source 16 is reflected to a prescribed direction. Then, a flat surface is decided at the top part of the prism 24, an acute angler θ is made against a collimation adjusted axial line 18, and a light beam emitted from the light source 16 is interrupted by the side part 22 of the wall part 12. Thus, the whole opening of the light window 14 can be uniformly irradiated. |
