| 摘要 |
A light guide (40) formed of a plurality (between 2 and 100) of layers of transparent dielectric material (42) such as LEXAN<TM>, with each adjacent pair of dielectric layers separated by an air gap (44). The dielectric material's index of refraction is between about 1.1 and 2.0. The light guide has a closed transverse cross-sectional shape, and has a low aspect ratio of between about 3 and 36. A light source (56) emits substantially collimated light rays into one end of the light guide. A mirror (54) at the opposite end of the light guide reflects the light back toward the light source. One or more layers of light modification material can be added to the light guide to alter a selected characteristic of the light emitted through the light emitting portion of the light guide. The light modification material layer may be a diffuser having a selected density, a colour correcting filter, a colour filter, an aperture mask, or a polarizing film. A lighting fixture having a housing (66) is also provided; a plurality of layers of dielectric material are mounted in a front portion of the housing. Each adjacent pair of dielectric material layers is separated by an air gap. A light source (64) emits substantially collimated light rays into a one side of the housing. A mirror (70) mounted in the opposite side of the housing reflects the lgiht back toward the light source. |
