Waveguide light multiplexer using crossed gratings

A display system comprising:

• a waveguide;
• an outcoupling optical element comprising:
• at least one or more first diffraction gratings having a grating direction, the one or more first diffraction gratings disposed on a major surface of the waveguide;
• and
• at least one or more second diffraction gratings having a grating direction, the one or more second diffraction gratings disposed with respect to the one or more first diffraction gratings such that the grating direction of the one or more first diffraction gratings is perpendicular to the grating direction of the one or more second diffraction gratings;
• wherein the at least one or more second diffraction gratings or the at least one or more first diffraction gratings are disposed over the other, and wherein the one or more first diffraction gratings and one or more second diffraction gratings are disposed on the same side of the waveguide;
• an incoupling optical element positioned at a separate laterally displaced location on the waveguide from the outcoupling optical element;
• and
• an image injection device comprising a light emitting diode (LED) and configured to direct image light having image content onto the incoupling optical element, and wherein the incoupling optical element is configured to incouple the image light into the waveguide such that the image light is guided within the waveguide to the outcoupling optical element.