Display illumination light guide

摘要

A near-eye display device has a multi-color light source, a micro display, an optical system and a light guide. The optical system collimates and redirects light from the micro display to an optical axis of the device. The light guide comprises multiple color-specific layers, an in-coupling diffraction grating through which light from the source enters the light guide, and an out-coupling diffraction grating through which light from the light guide exits towards the micro display. Two distinct embodiments are detailed: each different color-specific layer of the light guide is defined by a different refractive index; or by a different color-specific filter. In one example there is one in-coupling diffraction grating through which all light from the source enters the light guide; in another there are at least first and second in-coupling diffraction gratings on opposed light guide surfaces through which different colors enter the light guide.

主权项

1. An apparatus comprising:
a multi-color light source; a micro display; an optical system for collimating and redirecting light reflected from the micro display to an optical axis defined by a near-eye display device; and a light guide, said light guide conducting light from said multi-color light source to said micro display, said light guide having a plurality of stacked color-specific layers, an in-coupling diffraction grating through which light from the multi-color light source enters the light guide, and an out-coupling diffraction grating through which light from the light guide exits towards the micro display.