Hollow Light Guide for Light Weight and High Efficiency Planar Illuminator

Light guides have been widely used for transforming line or point sources into planar illuminators for general lighting applications. A hollow light guide with a diffusive reflection cavity (DRC) associated with edge-light LED light sources has been proposed to resolve the issues of weight, uniformity and efficiency simultaneously. The experiment shows an overall efficiency of 84.35%, uniformity of 90.5%, at the height of 35cm, the illumination is 1396 lux that only needed 3 watts of total LED driving power. The weight of the whole module is 180g, 55% lighter than the solid light guide with the same size.