Patent ID: 8513900

Claim:
An apparatus for tuning a color produced by a lamp having a plurality of light-emitting diodes (LEDs) including a plurality of groups of LEDs wherein each group of LEDs produces light having a different color and wherein a current applied to each group of LEDs is independently variable, the apparatus comprising: an adjustment fixture configured to hold the lamp; a spectrometer configured to detect and measure a color of light produced by the lamp; a current supply subsystem configured to deliver a current to each one of the groups of LEDs, wherein the current delivered to each one of the groups of LEDs is independently variable; and a control system coupled to the spectrometer and the current supply subsystem, the control system configured to receive the measured light color from the spectrometer and to provide a current controlling signal to the current control circuit, wherein the control system includes a control processor configured to: operate the current supply subsystem and the spectrometer to make at least two initial measurements of the color of the light, for at least two different testing distributions of a total current among the groups of LEDs; and determine, based on the at least two initial measurements, a target distribution of the total current among the groups of LEDs, wherein the target distribution of the total current causes the lamp to produce light having a color closely approximating a target color.