US Patent 9851490 Light guide for low profile luminaire

A luminaire comprising a heat sink, a light source and a light guide. The light source is carried by the heat sink and configured to emit a source light. The light source includes a heat spreader having an inner surface and an outer surface, and a plurality of light-emitting diodes (LEDs) carried by a circuit board and disposed generally along an outer peripheral perimeter portion of the inner surface of the heat spreader, and positioned in thermal communication with the heat spreader. The light guide includes a lens with a plurality of optical elements disposed within the lens.