Patent ID: 7772604

Claim:
A separate optical device operable to couple to a separate LED, the separate optical device comprising: an entrance surface to receive light from a separate LED when the separate optical device is coupled to the separate LED; an exit surface opposite from and within 10% of a minimum distance from the entrance surface so that all light rays having a direct transmission path from the entrance surface to the exit surface will be incident on the exit surface at less than or equal to a critical angle at the entrance surface, wherein the exit surface has an area that is within 10% of a minimum area necessary to fully conserve radiance for a desired half-angle of light projected from the separate optical device; a set of sidewalls, wherein each sidewall has a plurality of sections, each section based on a different curve and adapted to reflect light having a straight transmission path to that section in a corresponding angular sub-tense to the exit surface so that the light is incident on the exit surface at less than or equal to the critical angle at the exit surface and wherein the separate optical device is shaped to emit in a uniform distribution pattern from the exit surface at least 70% of the light entering the separate optical device through the entrance surface.