Patent ID: 7855499

Claim:
A back light unit, comprising: an electron emitter substrate emitting electrons from a front surface and a rear surface thereof; a first anode substrate arranged opposite to the front surface of the electron emitter substrate, the first anode substrate receiving electrons emitted from the electron emitter substrate, emitting light in response to the electrons, and outputting the light from a front surface of the first anode substrate; and a second anode substrate arranged opposite to the rear surface of the electron emitter substrate, the second anode substrate receiving electrons emitted from the electron emitter substrate, emitting light in response to the electrons, and reflecting the light to the first anode substrate, and the second anode substrate including a photoluminescent material arranged between a reflective layer and a transparent anode electrode, the transparent anode electrode being arranged between the rear surface of the electrode emitter substrate and the photoluminescent material.