Display system

摘要

A display system comprises an optical waveguide and a light engine. The light engine generates multiple input beams which form a virtual image. An incoupling grating of the waveguide couples each beam into an intermediate grating of the waveguide, in which that beam is guided onto multiple splitting regions. The intermediate grating, formed by modulations on a first surface of the waveguide, splits that beam at the splitting regions to provide multiple substantially parallel versions of that beam. Those multiple versions are coupled into an exit grating of the waveguide, in which the multiple versions are guided onto multiple exit regions. The exit grating diffracts the multiple versions of that beam outwardly. The multiple input beams thus cause multiple exit beams to exit the waveguide which form a version of the virtual image. A polarization state of each beam interacting with the modulations is controlled by a retarder film.

主权项

1. A display system comprising:
an optical waveguide having an incoupling grating, an intermediate grating including modulations on a first surface of the optical waveguide, and an exit grating; and a light engine configured to generate multiple input beams, each beam being substantially collimated and directed to the incoupling grating in a unique inward direction, whereby the multiple input beams form a virtual image which depends on the location of that point in the image; wherein the intermediate and exit grating have widths substantially larger than the beams' diameters; wherein the intermediate grating has a height that increases from an inner edge of the optical waveguide to an outer edge of the optical waveguide in a lateral direction along its width; wherein the incoupling grating is arranged to couple each beam into the intermediate grating, in which that beam is guided onto multiple splitting regions of the intermediate grating in a direction along the width of the intermediate grating; wherein the intermediate grating is arranged to split that beam at the splitting regions to provide multiple substantially parallel versions of that beam which are coupled into the exit grating, in which the multiple versions are guided onto multiple exit regions of the exit grating, the exit regions lying in a direction along the width of the exit grating; wherein the exit grating is arranged to diffract the multiple versions of that beam outwardly, the multiple input beams thus causing multiple exit beams to exit the waveguide which form a version of the virtual image; and wherein a polarization state of each beam interacting with the modulations of the intermediate grating on the first surface of the optical waveguide is controlled by a retarder film on a second surface of the optical waveguide opposing the first surface.