Patent ID: 8297783

Claim:
A light emitting device comprising a light emitting diode (LED) that is operated by a driving bias and a emits first light, and a phosphor layer including a phosphor that partially wavelength-converts a first light and emits a second light, thereby emitting white light using the first light and the second light, wherein the phosphor has a maximum conversion efficiency at a first level of the driving bias, and the LED has a maximum conversion efficiency at a second level of the driving bias, the first level being different from the second level, wherein the LED is a blue LED that emits blue light, and the phosphor is a red phosphor that partially wavelength-converts the blue light and emits red light, wherein the phosphor layer further includes a yellow phosphor that partially wavelength-converts the blue light and emits yellow light, and a green phosphor that partially wavelength-converts the blue light and emits green light.