White light emitting device

Abstract

A white light emitting device includes a structure for emitting white light having at least four wavelengths by using two or less LEDs, where the LEDs include a blue/green LED emitting blue and green wavelengths of light. The device also includes means for emitting red wavelength of light.

1 . A white light emitting device comprising: a structure for emitting white light having at least four wavelengths by using two or less light emitting diodes (LEDs),
 wherein the LEDs comprise a blue/green LED emitting blue and green wavelengths of light; and   the device comprising red light emitting means.   
     
     
         2 . The white light emitting device according to  claim 1 , wherein the blue/green LED comprises an InGaN-based LED. 
     
     
         3 . The white light emitting device according to  claim 1 , wherein the red light emitting means comprises an InGaAlP-based LED. 
     
     
         4 . The white light emitting device according to  claim 1 , wherein the red light emitting means comprises red phosphor. 
     
     
         5 . The white light emitting device according to  claim 1 , wherein the red light emitting means comprises a red Photon Recycling System (PRS). 
     
     
         6 . The white light emitting device according to  claim 1 , the white light has a light emission spectrum with a blue peak wavelength in the range of 440 to 470 nm, and a green peak wavelength in the range of 500 to 530 nm, a yellow peak wavelength in the range of 560 to 580 nm and a red peak wavelength in the range of 620 to 640 nm. 
     
     
         7 . The white light emitting device according to  claim 1 , the white light has a light emission spectrum with a blue peak wavelength in the range of 450 to 460 nm, a green peak wavelength in the range of 505 to 515 nm, and a yellow peak wavelength in the range of 565 to 575 nm, and a red peak wavelength in the range of 630 to 640 nm. 
     
     
         8 . The white light emitting device according to  claim 7 , the white light has a color rendering index of at least 95. 
     
     
         9 . The white light emitting device according to  claim 1 , further comprising yellow phosphor,
 wherein the red light emitting means comprises at least one selected from a group consisting of a red LED, a red PRS and red phosphor.   
     
     
         10 . The white light emitting device according to  claim 9 , wherein the yellow phosphor has a peak wavelength in the range of 540 to 590 nm. 
     
     
         11 . The white light emitting device according to claim  1 , wherein the red light emitting means comprises an amber/red LED emitting amber and red wavelengths of light. 
     
     
         12 . The white light emitting device according to  claim 1 , wherein the blue/green LED is adapted to emit amber wavelength of light along with blue and green wavelengths of light, and
 the red light emitting means comprises a red LED emitting red wavelength of light.