Systems, devices, and methods for eyebox expansion in wearable heads-up displays
Systems, devices, and methods for expanding the eyebox of a wearable heads-up display are described. A light guide with an expanded eyebox includes a light guide material, an in-coupler, an outcoupler, and a gradient refractive index (GRIN) material. The in-coupler and the out-coupler may comprise a GRIN material. An eyeglass lens with expanded eyebox includes a light guide with expanded eyebox. A wearable heads-up display includes an eyeglass lens including a light guide with an expanded eyebox.
1. A light guide comprising:
a light guide material;
a gradient refractive index (GRIN) material carried by the light guide material;
an in-coupler;
an out-coupler; and
an exit pupil expander hologram disposed between the in-coupler and the out-coupler,
wherein the exit pupil expander hologram is recorded in the GRIN material.
2. The light guide of claim 1 wherein a first portion of the GRIN material is disposed between the in-coupler and the light guide material and a second portion of the GRIN material is disposed between the out-coupler and the light guide material.
3. The light guide of claim 2 wherein the GRIN material comprises a single continuous layer of GRIN material carried by a surface of the light guide material.
4. The light guide of claim 1 wherein the in-coupler comprises an in-coupler hologram and the out-coupler comprises an out-coupler hologram.
5. The light guide of claim 1 wherein the in-coupler comprises an in-coupler surface relief grating and the out-coupler comprises an out-coupler surface relief grating.
6. The light guide of claim 1 wherein the GRIN material comprises a GRIN photopolymer material.
7. The light guide of claim 6 wherein the in-coupler comprises an in-coupler hologram recorded in a first portion of the GRIN material and the out-coupler comprises an out-coupler hologram recorded in a second portion of the GRIN material.
8. The light guide of claim 7 , wherein the exit pupil expander hologram is recorded in a third portion of the GRIN material, the third portion of the GRIN material positioned in between the first portion of the GRIN material and the second portion of the GRIN material on a surface of the light guide material.
9. A lens for use in a wearable heads-up display, the lens comprising: a lens material; and a light guide integrated with the lens material, the light guide comprising: a light guide material; a gradient refractive index (GRIN) material carried by the light guide material; an in-coupler; an out-coupler; and an exit pupil expander hologram disposed between the in-coupler and the out-coupler, wherein the exit pupil expander hologram is recorded in the GRIN material.
10. The lens of claim 9 wherein the light guide is integrated inside the lens material.
11. The lens of claim 9 wherein a first portion of the GRIN material is disposed between the in-coupler and the light guide material and a second portion of the GRIN material is disposed between the out-coupler and the light guide material.
12. The lens of claim 11 wherein the GRIN material comprises a single continuous layer of GRIN material carried by a surface of the light guide material.
13. The lens of claim 11 , wherein the GRIN material comprises a GRIN photopolymer material, the in-coupler comprises an in-coupler hologram recorded in a first portion of the GRIN material, and the out-coupler comprises an out-coupler hologram recorded in a second portion of the GRIN material.
14. The lens of claim 13 , wherein the exit pupil expander hologram is recorded in a third portion of the GRIN material, the third portion of the GRIN material positioned in between the first portion of the GRIN material and the second portion of the GRIN material on a surface of the light guide material.
15. A wearable heads-up display (WHUD) comprising: a support structure; a light engine carried by the support structure; and a transparent combiner positioned and oriented to appear in a field of view of an eye of a user when the support structure is worn on a head of the user, the transparent combiner comprising: a lens; and a light guide integrated with the lens, the light guide comprising: a light guide material; a gradient refractive index (GRIN) material carried by the light guide material; an in-coupler; an out-coupler; and an exit pupil expander hologram disposed between the in-coupler and the out-coupler, wherein the exit pupil expander hologram is recorded in the GRIN material.
16. The WHUD of claim 15 wherein a first portion of the GRIN material is disposed between the in-coupler and the light guide material and a second portion of the GRIN material is disposed between the out-coupler and the light guide material.
17. The WHUD of claim 16 wherein the GRIN material comprises a single continuous layer of GRIN material carried by a surface of the light guide material.
18. The WHUD of claim 15 wherein the GRIN material comprises a GRIN photopolymer material, the in-coupler comprises an in-coupler hologram recorded in a first portion of the GRIN material, and the out-coupler comprises an out-coupler hologram recorded in a second portion of the GRIN material.
19. The WHUD of claim 18 , wherein the exit pupil expander hologram is recorded in a third portion of the GRIN material, the third portion of the GRIN material positioned in between the first portion of the GRIN material and the second portion of the GRIN material on a surface of the light guide material.