Patent ID: 7652237
Filing Date: 2010-01-26
Classification: H05B

Abstract:
1. Colour point control system comprising an LED device, comprising a plurality of light-emitting diodes for emitting a first light, said diodes fixed on a substrate, a layer of material disposed on at least one light-emitting diode for converting at least a first portion of the first light into a second light, a photo-sensor for measuring a second portion of the first light of each single diode of said plurality of light-emitting diodes during a turn-off time when all other diodes are turned off, wherein the measured second portion of the first light is emitted to the photo-sensor without passing the layer, and a controller for sequentially turning off said diodes and for comparing the second portion of the first light of each single diode measured by the photo-detector to a default value and to adapt the emitted second portion of first light of each single diode to said default value.