| 摘要 |
PROBLEM TO BE SOLVED: To provide a optical diffusion plate with high screen irradiation efficiency, uniform optical diffusion and simple constitution, its manufacturing method and a optical guide device for illumination. SOLUTION: The surface of an optical guide plate 1 is covered with a polymer film 2, having a modulated refractive index so as to be nearly equivalent optically to a face with a modulated structure of a projecting and recessing face 11. Thereby when the optical guide plate 1 transmits the light from the light source, it is diffused with the polymer film 2 and fine parts 3 and emitted to the outside. Consequently, the screen irradiation efficiency is enhanced, and the uniform light diffusion is realized. Furthermore, the optical diffusion plate is simply constructed with the optical guide plate 1, the polymer film 2, the fine parts 3 and an ultraviolet ray absorption (or reflection) layer 4. |
