LIGHT GUIDE WITH INTERNAL LIGHT RECIRCULATION

摘要

This disclosure provides systems, methods, and apparatuses for illumination using illumination systems having a light guide. A light source is configured to inject light into a light input edge of the light guide. The light guide is configured to recirculate the injected light therein such that the light passes back and forth across the light guide one or more times. The light guide includes light-turning features that extract light out of the light guide. To promote light recirculation, the light-turning features have a per-pass light extraction efficiency of about 50% or less and one or more edges of the light guide may be reflective. The light extracted out of the light guide by the light-turning features may be used to illuminate a display.