Multi-waveguide LED luminaire with outward emission

1. A luminaire, comprising:

a frame;

a plurality of optical waveguides retained by the frame and bounding a cavity, each of the optical waveguides comprising:

a top end and a bottom end opposite the top end;

a coupling portion disposed at the top end;

an inner side facing the cavity and an outer side opposite the inner side, wherein the inner and outer sides are disposed between the top and bottom ends;

at least one light emitting diode (LED) associated with each optical waveguide, each of the LEDs being disposed opposite, and configured to direct light into, the coupling portion of the associated optical waveguide; and

wherein each optical waveguide is configured to receive the light via the coupling portion and emit the light primarily from the outer side.

2. The luminaire of claim 1 , wherein the inner side of each of the optical waveguides is configured to prevent at least some of the light received via the coupling portion from escaping the optical waveguide at the inner side by redirecting the at least some of the light back into the optical waveguide.

3. The luminaire of claim 1 , wherein each of the LEDs is enclosed within the frame by a cover configured to transfer heat by thermal conductivity from the LED to an exterior of the luminaire.

4. The luminaire of claim 3 , wherein the cavity is open opposite from the cover.

5. The luminaire of claim 1 , wherein the coupling portion of each of the optical waveguides comprises refractive and reflective portions that are arranged to collimate and direct the light into the top end of the optical waveguide.

6. The luminaire of claim 1 , wherein each of the optical waveguides tapers from the top end towards the bottom end.

7. The luminaire of claim 1 , wherein the inner side of each optical waveguide faces the inner side of another of the optical waveguides.

8. The luminaire of claim 1 , wherein to emit the light primarily from the outer side, the inner side of each of the optical waveguides comprises light extraction features configured to direct the light primarily toward the outer side, and the outer side comprises scalloped features configured to spread the light up and down as the light is emitted.

9. The luminaire of claim 1 , further comprising:

a central enclosure connected to the frame and extending into the cavity; and

operating circuitry electrically connected to the LEDs and retained in the central enclosure, wherein the operating circuitry is configured to supply power to the LEDs.

10. The luminaire of claim 9 , wherein:

the central enclosure comprises an opening exposed to the cavity;

the operating circuitry comprises a sensor supported in the opening;

the sensor is configured to sense ambient light level and vary an illumination level of the luminaire in accordance with the sensed ambient light level.

11. The luminaire of claim 1 , wherein each of the optical waveguides further comprises an end light extraction feature adjacent to the bottom end and configured to increase the light emitted from the optical waveguide on a single pass of the light through the optical waveguide.

12. The luminaire of claim 11 , wherein the end light extraction feature of each optical waveguide comprises a wedge-shaped protrusion on the inner side, and a wedge-shaped channel on the outer side.

13. The luminaire of claim 1 , further comprising a mounting plate opposite an open end of the cavity.

14. The luminaire of claim 1 , further comprising a respective circuit board corresponding to each optical waveguide, wherein the LEDs associated with each optical waveguide are mounted to the circuit board corresponding to the optical waveguide.

15. An optical waveguide comprising:

a top end and a bottom end opposite the top end;

a coupling portion disposed at the top end and configured to direct light into the top end;

an outer side disposed between the top and bottom ends, wherein the outer side is configured to emit most of the light directed into the top end by the coupling portion;

an inner side opposite the inner side and between the top and bottom ends, wherein the inner side comprises light extraction features configured to direct at least a portion of the light received via the coupling portion primarily towards the outer side;

an end light extraction feature adjacent to the bottom end and configured to increase the emission of the light by the outer side that occurs on a single pass of the light directed into the top end through the optical waveguide.

16. The optical waveguide of claim 15 , wherein to direct the light into the top end, the coupling portion comprises refractive and reflective portions that are arranged to collimate the light.

17. The optical waveguide of claim 15 , wherein the optical waveguide tapers from the top end towards the bottom end.

18. The optical waveguide of claim 15 , wherein the outer side comprises scalloped features configured to spread the light up and down as the light is emitted.

19. The optical waveguide of claim 15 , wherein the end light extraction feature comprises a wedge-shaped protrusion on the inner side, and a wedge-shaped channel on the outer side.

20. A method of assembling a luminaire, the method comprising:

inserting an optical waveguide into a frame of the luminaire such that:

a primary light emitting surface of the optical waveguide faces away from a cavity of the luminaire;

a surface of the optical waveguide configured to redirect light toward the primary light emitting surface is adjacent to the cavity;

a bottom end of the optical waveguide is inserted into the frame before a top end of the optical waveguide;

a coupling cavity disposed at the top end of the optical waveguide is exposed;

mounting at least one light emitting diode (LED) into the frame of the luminaire such that the at least one LED is configured to direct light toward the coupling cavity of the optical waveguide;

sealing a cover onto the frame over the at least one LED and the optical waveguide.