Systems, devices, and methods for curved waveguides integrated with curved eyeglass lenses
Systems, devices, and methods that implement waveguides in curved transparent combiners that are well-suited for use in wearable heads-up displays (WHUDs) are described. Waveguide structures with in-couplers and out-couplers are integrated with curved eyeglass lenses to provide transparent combiners that substantially match the shape, size, and geometry of conventional eyeglass lenses and can, in some implementations, embody prescription curvatures to serve as prescription eyeglass lenses. The waveguides and in-/out-couplers are planar or curved depending on the implementation. WHUDs that employ such curved transparent combiners are also described.
1. A wearable heads-up display (WHUD) comprising:
a support structure that in use is worn on a head of a user;
a display light source to provide display light; and
a transparent combiner carried by the support structure and positioned in a field of view of an eye of the user when the support structure is worn on the head of the user, the transparent combiner comprising:
a prescription eyeglass lens having a prescription curvature;
a curved waveguide at least partially embedded in an inner volume of the prescription eyeglass lens, wherein a curvature of the curved waveguide matches the prescription curvature of the prescription eyeglass lens;
an optical in-coupler physically coupled to a first area of the curved waveguide, the optical in-coupler to receive display light from the display light source and optically in-couple display light into the curved waveguide; and
an optical out-coupler physically coupled to a second area of the curved waveguide, the optical out-coupler to receive display light from the curved waveguide and optically out-couple display light into the field of view of the eye of the user.
2. The WHUD of claim 1 wherein the optical in-coupler and the optical out-coupler are each selected from a group consisting of: a hologram, a holographic optical element, a volume diffraction grating, a surface relief diffraction grating, a transmission grating, and a reflection grating.
3. The WHUD of claim 1 wherein the first area of the curved waveguide to which the optical in-coupler is physically coupled is an area on an outer surface of the curved waveguide.
4. The WHUD of claim 1 wherein the second area of the curved waveguide to which the optical out-coupler is physically coupled is an area on an inner surface of the curved waveguide.
5. The WHUD of claim 1 wherein the curved waveguide is completely contained in the inner volume of the prescription eyeglass lens.
6. The WHUD of claim 1 wherein the prescription eyeglass lens includes a convex world-side surface and a concave eye-side surface.
7. The WHUD of claim 6 wherein the optical out-coupler is positioned and oriented to apply a compensatory optical function to display light when the optical out-coupler out-couples display light from the curved waveguide, the compensatory optical function matched to an optical function of the convex world-side surface of the prescription eyeglass lens.
8. The WHUD of claim 1 wherein a length of the curved waveguide extends across a full width of the prescription eyeglass lens.
9. The WHUD of claim 8 wherein the second area of the curved waveguide to which the optical out-coupler is physically coupled is positioned at or proximate a center of the prescription eyeglass lens.
10. The WHUD of claim 1 wherein the first area of the curved waveguide is a first planar area of the curved waveguide and the second area of the curved waveguide is a second planar area of the curved waveguide, and wherein the optical in-coupler is a planar optical in-coupler physically coupled to the first planar area of the curved waveguide and the optical out-coupler is a planar optical out-coupler physically coupled to the second planar area of the curved waveguide.
11. The WHUD of claim 1 wherein the first area of the curved waveguide is a first curved area of the curved waveguide and the second area of the curved waveguide is a second curved area of the curved waveguide, and wherein the optical in-coupler is a curved optical in-coupler physically coupled to the first curved area of the curved waveguide and the optical out-coupler is a curved optical out-coupler physically coupled to the second curved area of the curved waveguide.
12. The WHUD of claim 1 wherein the display light source is selected from a group consisting of: a laser projector and a microdisplay.
13. The WHUD of claim 1 wherein the support structure has a shape and geometry of a pair of eyeglasses.