Light-emitting devices for liquid crystal displays

Abstract

A lighting system includes a panel having an edge, the edge having a thickness defined between a front surface of the panel and a back surface of the panel, the panel configured to propagate light therein. The lighting system further includes a first light emitting diode (LED) light source and a second LED light source disposed in serrated arrangement along the edge of the panel so that light emitted from respective light emitting surfaces of the light sources impinges on the edge of the panel and enters the panel through the edge and so that the light emitting surfaces lie in respective planes that are not parallel.

1 . A system, comprising:
 a panel having an edge, the edge having a thickness defined between a front surface of the panel and a back surface of the panel, the panel configured to propagate light therein; and   a first light emitting diode (LED) light source and a second LED light source disposed in serrated arrangement along the edge of the panel so that light emitted from respective light emitting surfaces of the light sources impinges on the edge of the panel and enters the panel through the edge and so that the light emitting surfaces lie in respective planes that are not parallel.   
     
     
         2 . The system of  claim 1 , wherein there are a plurality of light sources disposed in serrated arrangement along the edge of the panel and each light source has a length perpendicular to the thickness direction of the panel, an aggregate of the lengths being more than a width of the panel measured between side edges of the panel and along the edge in a direction perpendicular to the thickness direction of the panel. 
     
     
         3 . The system of  claim 1 , wherein each light source comprises a light emitting device die that has an upper surface defining the light emitting surface and a pattern of openings in at least the upper surface, the pattern of openings creating a dielectric function that varies spatially according to the pattern, the pattern of openings being configured such that the light that is emitted through the upper surface is more collimated than a Lambertian distribution. 
     
     
         4 . The system of  claim 3 , wherein the pattern is a periodic pattern with an ideal lattice constant and detuned by a detuning parameter ranging between zero percent and 15 percent.