Back-lighted box for displaying placards or transparencies - has e.g. opal matt glass diffusion plate and reflector sepd. by edge-lighted stack of light guides

摘要

A strip lamp (9) is installed in the box (1) along the end (11) of a light-guiding element (10) whose thickness decreases towards the other end. The rear wall (2) is coated internally with a a diffuse reflector (8). - The element (10) comprises a stack of flat sheets of different lengths set at an angle of about 10 deg. to the reflector (8). A sheet of metal (18) is bent around the lamp (9) to concentrate its light on the end (11) of the element (10). Direct lighting of the diffusion plate (7) is screened (21).