Patent ID: 8729823

Claim:
A regulating system comprising: a tricolor LED system comprising: at least one first LED that emits light having a first color, at least one second LED that emits light having a second color, and at least one third LED that emits light having a third color, at least one fourth LED that emits light having a fourth color, a sensor that detects light emitted by the LEDs and generating sensor signals representing characteristics of the light, wherein the sensor is an RGB sensor that measures characteristics of mixed light emitted by the tricolor LED system and the fourth LED during a first time interval and generates a triple set of values representing the characteristics of the mixed light, and the sensor measures characteristics of light emitted by the fourth LED during a second time interval, where the tricolor LED system does not emit light, and generates a triple set of values representing the characteristics of the light emitted by the fourth LED, a controller that outputs control signals depending on the sensor signals and reference values, and LED drivers that drive the first, second, third and fourth LEDs depending on the control signals.