Patent ID: 8143791

Claim:
A light-emitting device, comprising: a plurality of light-emitting elements, each of the plurality of light-emitting elements configured to emit light upon receiving electric current; driving circuitry coupled to the plurality of light-emitting elements, the driving circuitry configured to supply electric current to each of the plurality of light-emitting elements; a light-mixing region configured to receive light emitted by the plurality of light-emitting elements; test circuitry coupled to the driving circuitry, the test circuitry configured to control the driving circuitry to supply electric current to a plurality of groups of light-emitting elements in sequence, wherein each of the plurality of groups of light-emitting elements includes one or more of the plurality of light-emitting elements; a plurality of photodetectors arranged at a plurality of locations of the light-mixing region, wherein each of the plurality of photodetectors is configured to detect an intensity of light present at a location of the light-mixing region and generate a corresponding detection signal; a reflector having a reflective surface configured to reflect light emitted by the plurality of light-emitting elements to the light-mixing region the reflector having a plurality of openings defined therein and wherein at least one of the plurality of photodetectors is disposed within or below the plurality of openings; and process circuitry coupled to the plurality of photodetectors and the driving circuitry, wherein the process circuitry is configured to process the detection signals generated by the plurality of photodetectors and adjust an electric current supplied to each of the plurality of light-emitting elements based on the processing such that at least one characteristic of light emitted by all of the plurality of light-emitting elements is substantially the same at each of the plurality of locations of the light-mixing region.