Patent ID: 8733968

Claim:
A lighting device comprising: a first group of solid state light emitters; a second group of solid state light emitters; and at least first and second portions of luminescent material; wherein: if the first group of solid state light emitters is illuminated, a portion of light emitted from the first group of solid state light emitters would excite the first portion of luminescent material, and a mixture of light exiting the lighting device that was emitted from the first group of solid state light emitters and light exiting the lighting device that was emitted from the first portion of luminescent material would, in the absence of any additional light, have a first group mixed illumination corresponding to a first point on a 1931 CIE Chromaticity Diagram, the first point having a first correlated color temperature; if the second group of solid state light emitters is illuminated, a portion of light emitted from the second group of solid state light emitters would excite the second portion of luminescent material, and a mixture of light exiting the lighting device that was emitted from the second group of solid state light emitters and light exiting the lighting device that was emitted from the second portion of luminescent material would, in the absence of any additional light, have a second group mixed illumination corresponding to a second point on a 1931 CIE Chromaticity Diagram, the second point having a second correlated color temperature; and the first correlated color temperature differs from the second correlated color temperature by at least 50 K.