Light source and liquid crystal display device using this light source

摘要

A small light source unit of simple structure that emits light forward with high efficiency is well-suited as a backlight in a liquid crystal display device. The light director in this unit has reflective internal faces adjacent opposite peripheral regions of the entrance face and two refractive index interfaces in it. The reflective internal faces and the refractive index interfaces are oriented on inclined planes. The refractive index of a middle region between the two interfaces is the smallest among those of the three regions making up the light director.