| 摘要 |
Different arrangements for improving the coupling-in efficiency between an LED (140) assembly and a light guide (150) are disclosed. In a first arrangement, a substantially planar end of a light guide is seated on a perimeter wall of a support (142) that encloses a LED assembly, and a reflecting surface (222) enhances coupling efficiency of a light guide. Alternative arrangements use a separate coupler (220, 320, 450) disposed between the LED assembly and the light guide, which coupler has a paraboloid or aspheroid conformation to develop substantially collimated light that is directed into the light guide. The cavity (462) around the LED assembly and within the coupler, may be air or a material having an index of refraction that closely matches the index of refraction of the light guide material. |
