METHOD AND APPARATUS TO IMPROVE THE COLOUR RENDERING OF A SOLID STATE LIGHT SOURCE

摘要

This invention relates to a method and apparatus for improving the colour rendering of a lamp or light source. Specifically, a solid state light source such as an InGaN LED is driven by a modulated signal in which portions of the signal are provided with different forward currents within a single cycle. The different forward currents can provide a variation in the dominant wavelength emitted from the LED for each portion to provide a broader range of colour produced by the LED. The pulses and cycle may be of sufficient frequency to provide an apparent constant light to the human eye without colour change although the use of varying dominant wavelengths to provide the overall colour can improve the LEDs colour rendering. An improvement in such colour rendering may be particularly important when the lamp or light source is used for illumination either on its own or in conjunction with other LEDs.