摘要 |
To provide a uniformly illuminated panel of essentially uniform brightness throughout, although illuminated by essentially point source lamps, a box-like structural element (1) is provided having a light emitting surface (2) which has, in the direction of transmission of radiation therethrough, a ratio of reflection to transmission of radiation greater than 50%, and preferably between 80% to 95%, the interior wall surfaces of the hollow structure being reflective, and the hollow structure having a depth dimension, for example about 2 cm, which is small with respect to the height and width dimensions. |