Patent ID: 6824285
Filing Date: 2004-11-30
Classification: G02B

Abstract:
The light source unit comprising:a primary light source; and a light director, comprising plural adjacent regions, wherein said light director takes in light from said primary light source through an entrance face and outputs the light as emergent light from an exit face, wherein said light director has i) reflective internal surfaces adjacent opposite peripheral regions of the entrance face, ii) a first refractive index interface and a second refractive index interface disposed along a light path from the entrance face to said exit face, each of said first and second refractive index interfaces delineating the adjacent regions within said light director having different refractive indices, and iii) a refractive index of a region between said first refractive index interface and said second refractive index interface and said second refractive interface has a smallest value among those of said light director, wherein at least one of said first and said second refractive index interfaces describes inclined planes that refract said light from said primary light source causing refracted light to pass through said first and second refractive index interfaces in a direction of the emergent light from said exit face.