APPARATUS, METHOD TO CHANGE LIGHT SOURCE COLOR TEMPERATURE WITH REDUCED OPTICAL FILTERING LOSSES

摘要

The efficiency and color temperature of a lighting device may be improved by using wavelength shifting material, such as a phosphor, to absorb less desired wavelengths and transmit more desired wavelengths. A reflective filter (e.g., dichroic or dielectric mirror material) may pass desired wavelengths while returning or reflecting less desired wavelengths away from an optical exit back toward wavelength shifting material which may either be disposed in the optical path or on the periphery of the light source.