Illumination system for a flat-panel picture display device

Abstract

The invention relates to an illumination system comprising an optical waveguide of an optically transparent material having an exit surface and a plurality of end faces, and a light source whose light is coupled into the waveguide via at least one end face of the waveguide. The waveguide further comprises polarizing means for polarizing the light emitted by the light source. The waveguide comprises at least two layers, of which one layer comprises an optically anisotropic material having refractive indices n.sub.e and n.sub.o and the other layer comprises an optically isotropic material having a refractive index n.sub.i, in which one of the refractive indices n.sub.e or n.sub.o is equal to n.sub.i. For the refractive indices, n.sub.e or n.sub.o should be equal or substantially equal to n.sub.i in order that polarization separation occurs at the interface between the isotropic and the anisotropic material. The invention also relates to a flat-panel picture display device including such an illumination system.

Dependencies are inferred from the claim text.