Light diffusing device

摘要

A light diffusing device for obtaining a surface uniform in the brightness by using a luminous flux narrow in the radiating angle comprising a flat smooth transparent base plate having a favorable transparency and including a luminous flux incident area defined on one side surface, a conical concavity formed on the other side surface opposed to said one side surface, aligned with the luminous flux incident area and having a bottom area at least equal to said area and light diffusing reflecting means provided on all the side surfaces except the above mentioned other side surface. Said luminous flux incident area is used as a connecting part with the end portion of a light guide or a containing section for a light source. The above mentioned other side surface serves as a displaying surface for such display medium as of words or signs or as a luminous surface for introducing lights of a uniform brightness into a plurality of light guides.