LED White Source with Improved Color Rendering

摘要

A light source that generates light having an output optical spectrum is disclosed. The light source includes first and second LEDs and a layer of phosphor that is excited by light from the first LED. The layer of phosphor is positioned to convert a portion of the light from the first LED in a first LED optical spectrum to light having a phosphor spectrum. The second LED emits light in a second LED optical spectrum. The first and second LEDs are powered such that the output optical spectrum includes the first and second optical spectrums and the phosphor spectrum such that the output spectrum is more constant as a function of wavelength at wavelengths between 450 nm to 650 nm than the first or second optical spectrums or the phosphor spectrum. The invention can provide a white LED light source with improved color rendering.