Illumination system and display device

摘要

An illumination system includes a polarized light source which emits circularly polarized light of a particular handedness and a cholesteric filter having a region arranged to transmit circularly polarized light falling within a first wavelength band and to reflect other wavelengths of circularly polarized light. A reflector redirects the reflected light back towards the cholesteric filter. The cholesteric filter can include a first layer having portions which reflect red, green and blue light while transmitting other colors, and a second layer identical to the first layer but out of alignment therewith so that each region of the filter transmits only one color of light, the other colors being reflected.