| 摘要 |
The invention relates to alighting apparatus comprising a light emission unit (2) for emitting light (3) from an emission surface (4) in a main emission direction (6) and an outcoupling unit (7) for coupling the light out of the light emission unit. The outcoupling unit comprises a first surface (8) having a first central region (9) optically coupled to the emission surface and a first peripheral region (10)enclosing the first central region and a second surface (11) opposite to the first surface. The peripheral regions can be structured wherein the ratio of a) the area of the emission surface to b) the area of the first surface or the second surface is smaller than 0.5. This configuration can significantly decrease the likelihood of reabsorption of light by the emission surface thereby increasing the efficiency of extracting light out of the lighting apparatus. |
