Patent ID: 9091408
Filing Date: 2015-07-28
Classification: F21K,F21V,G02B,G02F

Abstract:
1. A backlight, comprising: a front and back reflector forming a hollow light recycling cavity, the front reflector being partially transmissive to provide an output illumination area, and wherein the front reflector has a reflectivity for p-polarized light that is: (1) constant, or (2) increases, with angle of incidence, and a transmission that generally decreases with angle of incidence; a component that provides the cavity with a desired balance of specular and diffuse characteristics, the component being characterized by a transport ratio greater than 15% at a 15 degree incidence angle and less than 95% at a 45 degree incidence angle, wherein the front or back reflectors can be or include the component, or the component can be distinct from the front and back reflectors, wherein the transport ratio for the component, for light of a given incidence angle, equals (F−B)/(F+B), where F is the amount of light scattered into forward directions upon interaction of the incident light with the component, and B is the amount of light scattered into backward directions upon interaction of the incident light with the component; and one or more light source members disposed to emit light into the light recycling cavity over a limited angular distribution.