Image display system with beam multiplication

An optical system for displaying an image to an eye of a user comprising:

• a) a light-guide optical element (LOE) having two planar major external surfaces that are parallel so as to support propagation of image illumination within the LOE by internal reflection at the major external surfaces, the LOE having a thickness h between the major external surfaces, the LOE having a coupling-in region and a propagation region;
• (b) a coupling-out configuration associated with the propagation region of the LOE and configured for coupling out at least part of the image illumination from the LOE towards the eye of the user;
• (c) an image projector for generating image illumination corresponding to a collimated image, the image projector being optically coupled to the LOE so as to introduce the image illumination into the coupling-in region of the LOE so as to propagate within the propagation region of the LOE by internal reflection;
• and
• (d) a beam-multiplication configuration associated with the LOE and configured for beam multiplication of the image illumination introduced into the coupling-in region of the LOE, the beam-multiplication configuration comprising a transparent plate having mutually parallel external surfaces, the transparent plate bonded to a major external surface of the LOE adjacent to the coupling-in region, the transparent plate providing a partially-reflective surface between the LOE and the plate, and further providing a reflector, the partially-reflective surface and the reflector being arranged to reflect, into the propagation region, image illumination that was introduced into the coupling-in region so as to fully illuminate the propagation region with both the collimated image and a conjugate of the collimated image, wherein the transparent plate extends along a length of the LOE adjacent to the coupling-in region.