Patent ID: 7209628

Claim:
An optical device for outputting light comprising: a lamp cavity including a light source and a polarization splitting layer, the polarization splitting layer transmitting light of a first polarization and reflecting light of a second polarization different than the first polarization, the polarization of at least a portion of the reflected light being converted to the first polarization in the lamp cavity, the polarization splitting layer transmitting the converted light; a base layer having first and second surfaces and a back surface spanning the first and second surfaces, the light from the light source entering the base layer through the back surface and propagating in the base layer by reflection from the first and second surfaces, the propagating light striking the first and second surfaces at incident angles and exiting the base layer when the incident angle is less than the critical angle; and a light control layer receiving light from the base layer and redirecting the received light to provide light with a controlled angular distribution.