PHOSPHOR-CENTRIC CONTROL OF COLOR CHARACTERISTIC OF WHITE LIGHT
Lighting systems and devices offer dynamic control or tuning of a color characteristic, e.g. color temperature, of white light. The exemplary lighting systems and devices are used for general lighting applications that utilize solid state sources to pump remotely deployed phosphors. Two or more phosphors emit visible light of different visible spectra, and these spectra are somewhat broad, e.g. pastel, so that combinations thereof can approach white light temperatures including points along the black body curve. Independent adjustment of the intensities of electromagnetic energy emitted by the solid state sources adjusts levels of excitations of the phosphors, in order to control a color characteristic of the visible white light output of the lighting system or device.
1 . A lighting system for a white light application, comprising:
a first solid state source configured to emit electromagnetic energy in a narrow first spectrum;
a first optical element arranged to receive electromagnetic energy from the first solid state source;
a first phosphor in the first optical element at a location for excitation by the electromagnetic energy from the first solid state source, the first phosphor being of a type excitable by electromagnetic energy of the first spectrum and when excited for emitting visible light of a second spectrum different from and broader than the first spectrum;
a second solid state source configured to emit electromagnetic energy in said first narrow spectrum;
a second optical element arranged to receive electromagnetic energy from the second solid state source but to receive little or no electromagnetic energy from the first solid state source, wherein the first optical element is arranged to receive little or no electromagnetic energy from the second solid state source;
a second phosphor in the second optical element at a location for excitation by the electromagnetic energy from the second solid state source, the second phosphor being of a type excitable by electromagnetic energy of the first spectrum and when excited for emitting visible light of a third spectrum different from and broader than the first spectrum, the third spectrum also being different from the second spectrum,
wherein a visible light output of the lighting system includes a combination of light of the second spectrum from excitation of the first phosphor and light of the third spectrum from excitation of the second phosphors, from the first and second optical elements, and the visible light output of the lighting system is at least substantially white; and
a controller coupled to the first and second solid state sources configured to enable adjustment of respective intensities of the electromagnetic energy of the first spectrum emitted by the first and second solid state sources to adjust relative levels of excitations of the first and second phosphors to control a spectral characteristic of the visible white light output of the lighting system.
2 - 37 . (canceled)