Tiled waveguide display with a wide field-of-view
A waveguide display includes light sources, a source waveguide, an output waveguide, and a controller. Light from each of the light sources is coupled into the source waveguide. The source waveguide includes gratings with a constant period determined based on the conditions for total internal reflection and first order diffraction of the received image light. The emitted image light is coupled into the output waveguide at several entrance locations. The output waveguide outputs expanded image lights at a location offset from the entrance location, and the location/direction of the emitted expanded image light is based in part on the orientation of the light sources. Each of the expanded image light is associated with a field of view of the expanded image light emitted by the output waveguide.
1. A source waveguide assembly comprising:
a waveguide body;
a first entrance area configured to in-couple a first image light corresponding to a first portion of an image from a first light source into the waveguide body;
a second entrance area configured to in-couple a second image light corresponding to a second portion of the image from a second light source into the waveguide body, the second portion of the image different than the first portion of the image;
a first exit area configured to output expanded first image light, the expanded first image light being the first image light expanded along two opposite directions; and
a second exit area configured to output expanded second image light, the expanded second image light being the second image light expanded along the two opposite directions.
2. The source waveguide assembly of claim 1 , wherein the first entrance area and the second entrance area are located at opposite edges of the source waveguide assembly.
3. The source waveguide assembly of claim 1 , wherein the first entrance area comprises a first coupling element and the second entrance area comprises a second coupling element, each of the first coupling element and the second coupling element comprising a plurality of grating elements of a grating period selected based on a refractive index of a material forming the waveguide body.
4. The source waveguide assembly of claim 1 , wherein the expanded first image light propagates along a first direction of the two opposite directions and the expanded second image light propagates along a second direction of the two opposite directions, the second direction opposite to the first direction.
5. The source waveguide assembly of claim 1 , wherein each of the in-coupled first image light and the in-coupled second image light undergoes a total internal reflection inside the waveguide body.
6. The source waveguide assembly of claim 1 , wherein each of the in-coupled first image light and the in-coupled second image light undergoes a first order diffraction inside the waveguide body.
7. The source waveguide assembly of claim 1 , further comprising a second waveguide body, the first waveguide body expanding light along a first dimension and the second waveguide body expanding light along a second dimension orthogonal to the first dimension.
8. A method comprising:
in-coupling, at a first entrance area, a first image light corresponding to a first portion of an image from a first light source into a waveguide body;
in-coupling, at a second entrance area, a second image light corresponding to a second portion of the image from a second light source into the waveguide body, the second portion of the image different than the first portion of the image;
expanding the first image light along two opposite directions;
expanding the second image light along two opposite directions;
outputting, at a first exit area, the expanded first image light; and
outputting, at a second exit area, the expanded second image light.
9. The method of claim 8 , wherein the first entrance area and the second entrance area are located at opposite edges of the waveguide body.
10. The method of claim 8 , wherein the first entrance area comprises a first coupling element and the second entrance area comprises a second coupling element, each of the first coupling element and the second coupling element comprising a plurality of grating elements of a grating period selected based on a refractive index of a material forming the waveguide body.
11. The method of claim 8 , wherein the expanded first image light propagates along a first direction of the two opposite directions and the expanded second image light propagates along a second direction of the two opposite directions, the second direction opposite to the first direction.
12. The method of claim 8 , further comprising:
undergoing, by the in-coupled first image light, a total internal reflection inside the waveguide body; and
undergoing, by the in-coupled second image light, a total internal reflection inside the waveguide body.
13. The method of claim 8 , further comprising:
undergoing, by the in-coupled first image light, a first order diffraction inside the waveguide body; and
undergoing, by the in-coupled second image light, a first order diffraction inside the waveguide body.
14. The method of claim 8 , further comprising:
expanding light, via the waveguide body, along a first dimension; and
expanding light, via a second waveguide body, along a second dimension that is orthogonal to the first dimension.