US Patent 10025093 Waveguide-based displays with exit pupil expander

A near eye or heads up display system includes a scan beam projector engine, an optical waveguide, and an exit pupil expander (EPE) optically coupled between the scan beam projector engine and the optical waveguide. The EPE improves the optical performance of the display system. The EPE could include a diffusive optical element, diffractive optical element, micro-lens array (MLA), or relay of aspherical lenses. A dual MLA EPE may have cells that prevent cross-talk between adjacent pixels. A dual MLA EPE may have a non-periodic lens array. The optical power of one MLA may be different from the other MLA.