| 摘要 |
A light box (1) is disclosed, comprising an optical cavity (3) and at least one elongated light source (4), the at least one light source (4) being arranged to direct light into the optical cavity (3) from an associated edge thereof, the optical cavity (3) comprising a first major face (5) comprising a prismatic micro-structured transparent material (51) to reflect part of the light from the at least one light source (4) back into the optical cavity (3), and to refract part of the light from the at least one light source (4) out of the light box (1), and an opposed reflective second major face to reflect the light from the at least one light source (4) back into the optical cavity (3), characterized in that said prismatic micro-structured transparent material (51) of the first major face comprises at least two portions (51a-d), the prismatic micro-structures of a first portion being not parallel to the prismatic micro-structures of a second portion. In such a way, control of uniformity of luminosity/illumination and glare can be improved. |
