Highly efficient compact head-mounted display system

Abstract

There is provided an optical device, including a light-transmitting substrate, having at least two parallel major surfaces, edges and an output aperture, an optical element for coupling light waves into the substrate to effect total internal reflection, at least one redirecting element positioned outside of the substrate, and at least one reflecting surface having at least one active side located between the two major surfaces of the light-transmitting substrate for coupling light waves out of the substrate, wherein light waves trapped inside the substrate are coupled out from the substrate through the output aperture substantially inclined in relation to the normal to the substrate major surfaces and are reflected from the redirecting element into a viewer's eye, and wherein the redirecting element is a single flat reflecting surface parallel to the major surfaces of the substrate.