Abstract: To permit visual observation of tanning effects obtained by a UV radiation amp, the UV radiation emitting material has admixed thereto a coating material which provides auxiliary visible radiation output in the yellow-green spectral range of between about 490-600 nm. Suitable materials are: 13% of strontium aluminate, activated with cerium; 79% of barium disilicate, activated with lead; 3% of zinc silicate, activated with manganese; and 5% of calcium halogen phosphate, activated with antimony and manganese, with the spectral ranges shown in FIG. 1, or 12% of strontium aluminate, activated with cerium; 68% of barium disilicate, activated with lead; and 20% of calcium halogen phosphate, activated with antimony and manganese, with the spectral ranges shown in FIG. 2.

Abstract: To provide a uniformly illuminated panel of essentially uniform brightness hroughout, 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.