Low profile luminaire and associated systems and methods

A luminaire comprising:

• a heat sink comprising a sidewall and a base that, in combination, define a recess;
• a light source carried by the heat sink and configured to emit a source light, the light source comprising
• a heat spreader that is fittedly disposed in the recess of the heat sink and has an inner surface and an outer surface, the heat spreader comprising a printed circuit board, and
• a plurality of light-emitting diodes (LEDs) disposed generally along an outer peripheral perimeter portion of the inner surface of the heat spreader, and positioned in thermal communication therewith;
• a reflector disposed generally coextensive with the plurality of LEDs and comprising an aperture formed in a medial region thereof, an outer edge of the aperture defining an inner rim of the reflector;
• and
• a light guide positioned between the reflector and the light source, the light guide characterized, at any position along its width, by a height defined as the distance between the inner surface of the heat spreader and a plane defined by the inner rim of the reflector, the light guide comprising a lens portion and a propagation region configured to change the source light into a first shaped light;
• wherein the source light is emitted from the light source incident upon the reflector, and is changed by the light guide into the first shaped light that is directed by the light guide through the aperture;
• and
• wherein a combination of the light source, the heat sink, and the reflector has an overall outside height H and an overall outside dimension D such that the ratio of H/D is equal to or less than 0.25.

A luminaire comprising:

• a heat sink;
• a light source carried by the heat sink and configured to emit a source light, the light source comprising
• a heat spreader comprising a circuit board having an inner surface and an outer surface, and
• a plurality of light-emitting diodes (LEDs) carried by and disposed generally along the inner surface of the heat spreader, and positioned in thermal communication therewith;
• a reflector disposed generally coextensive with the plurality of LEDs;
• and
• a light guide positioned between the reflector and the light source, wherein the light guide is configured to change the source light into a first shaped light;
• wherein the source light is emitted from the light source incident upon the reflector, and is changed by the light guide into the first shaped light.