Patent ID: 8827476

Claim:
An LED based illumination device, comprising: a color conversion cavity comprising a first interior surface including a first wavelength converting material and a second interior surface including a second wavelength converting material; a first LED mounted to a mounting board, the first LED configured to receive a first current, wherein light emitted from the first LED enters the color conversion cavity and primarily illuminates the first interior surface; and a second LED mounted to the mounting board, the second LED configured to receive a second current, wherein light emitted from the second LED enters the color conversion cavity and primarily illuminates the second interior surface, wherein light emitted by the first wavelength converting material, light emitted by the second wavelength converting material, light emitted by the first LED, and light emitted by the second LED are mixed in the color conversion cavity to produce a combined light that is emitted from the color conversion cavity; and wherein the first current and the second current are selectable to achieve a range of correlated color temperature (CCT) of the combined light output by the LED based illumination device.