Illumination and Color Management in Solid State Lighting

The use of multi-wavelength light emitting diodes to generate predominantly white light for illumination has increased dramatically over the past years. Due to the nonlinear and often unpredictable relation between current and light output (i.e. efficiency) of LED´s, direct feedback control using the actual optical intensity of each LED set has to be used to adjust and maintain the desired color points. While control of three-color systems (RGB) for display backlights has been shown, here we describe the control of a four color system (RGB+amber) with a three channel sensor