摘要 |
Different arrangements for improving the coupling-in efficiency between an LED assembly and a light guide are disclosed. In a first arrangement, a substantially planar end of a light guide is seated on a perimeter wall of a support that encloses a LED assembly, and a reflecting surface enhances coupling efficiency of a light guide. Alternative arrangements use a separate coupler 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 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.
|