Highly efficient compact head-mounted display system

Abstract

There is provided an optical device, including a light-transmitting substrate having at least two major surfaces and edges, a display source based on a time-sequential color imaging, characterized by a frame time, three different primary colors, and coupled-in brightness, an optical element for coupling light waves from the display source into the substrate to effect total internal reflection, at least one flat reflecting surface located between the two major surfaces of the light-transmitting substrate for coupling light waves out of the substrate, and a dynamic partially reflecting element for re-directing the coupled-out light waves into a viewer's eye, wherein the transmittance and the reflectance of the dynamic partially reflecting element is dynamically controllable to yield high reflection in each one of the three primary colors, while simultaneously having high transmittance of two other colors of the three primary colors.