SYSTEMS, DEVICES, AND METHODS FOR EYEBOXES WITH HETEROGENEOUS EXIT PUPILS

• US 20160327796A1
• Filed: 05/03/2016
• Published: 11/10/2016
• Est. Priority Date: 05/04/2015
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Thalmic Labs Inc.
• Inventors: Choi, Jaehong, Bailey, Matthew, Alexander, Stefan, Morrison, Vance R., Mahon, Thomas, Holland, Lloyd Frederick
• Granted Patent: US 10,197,805 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• CPC Class Codes: G02B 2027/015 involving arrangement aiming to get less bulky devices
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G02B 5/1876 Diffractive Fresnel lenses; Zone plates; Kinoforms G02B5/1842, G02B5/1847 take precedence; optical systems having diffractive correction means G02B27/0037; Fresnel lenses operating by refraction G02B3/08
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G03H 1/0252 Laminate comprising a hologram layer
• CPC Class Codes: G03H 1/2286 Particular reconstruction light G03H1/24 takes precedence; Beam properties
• CPC Class Codes: G03H 1/2645 Multiplexing processes, e.g. aperture, shift, or wavefront multiplexing
• CPC Class Codes: G03H 1/265 Angle multiplexing; Multichannel holograms G03H1/268 takes precedence
• CPC Class Codes: G03H 2001/2292 Using scanning means
• CPC Class Codes: G03H 2001/266 Wavelength multiplexing

Abstract

Systems, devices, and methods for engineering the eyebox of a display using multiple heterogeneous exit pupils are described. The eyebox of a display includes at least two heterogeneous exit pupils that are different from one another in terms of size and/or shape. Heterogeneous exit pupils may overlap, one may encompass another, or they may be completely spatially-separated from one another. Such configurations enable specific eyebox and/or visual display configurations that can be advantageous in certain applications. An example in which a scanning laser-based wearable heads-up virtual retina display implements a holographic combiner that is engineered to provide multiple heterogeneous exit pupils is described.

Claims

1. A holographic optical element (“

HOE”

) comprising;

at least one layer of holographic material, wherein the at least one layer of holographic material includes;

a first hologram to receive light from a light source and direct the light to a first exit pupil at or proximate an eye of a user, the first exit pupil having a first area; and

a second hologram to receive light from the light source and direct the light to a second exit pupil at or proximate the eye of the user, the second exit pupil having a second area that is different from the first area.

2. The HOE of claim 1 wherein the first hologram and the second hologram are positioned and oriented with respect to one another to cause the first exit pupil and the second exit pupil to at least partially overlap with one another at the eye of the user.

3. The HOE of claim 2 wherein the first hologram and the second hologram are positioned and oriented with respect to one another to cause the second exit pupil to encompass the first exit pupil at the eye of the user.

4. The HOE of claim 1 wherein the first hologram and the second hologram are positioned and oriented with respect to one another to cause the first exit pupil and the second exit pupil to be completely spatially-separated from one another at the eye of the user.

5. The HOE of claim 1 wherein the at least one layer of holographic material further includes at least one additional hologram, each additional hologram to receive light from the light source and direct the light to a respective exit pupil at or proximate the eye of the user, and wherein each respective exit pupil has a respective area that is different from the area of at least one of the other exit pupils.

6. The HOE of claim 1 wherein the at least one layer of holographic material includes a holographic material selected from a group consisting of:

a holographic film, a silver halide compound, and a photopolymer.

7. The HOE of claim 1 wherein the at least one layer of holographic material includes a first layer of holographic material and both the first hologram and the second hologram are in the first layer of holographic material.

8. The HOE of claim 1 wherein the at least one layer of holographic material includes a first layer of holographic material and a second layer of holographic material, the second layer of holographic material carried by the first layer of holographic material, and wherein the first hologram is in the first layer of holographic material and the second holograms is in the second layer of holographic material.

9. The HOE of claim 1 wherein the first exit pupil has a first geometry and the second exit pupil has a second geometry that is different from the first geometry.

10. The HOE of claim 1 wherein the first hologram and the second hologram are both multiplexed holograms that implement a same form of multiplexing, the form of multiplexing implemented by both the first hologram and the second hologram selected from a group consisting of:

angle multiplexing, wavelength multiplexing, angle and wavelength multiplexing, and spatial multiplexing holograms.

11. The HOE of claim 1 wherein the first hologram converges the light to the first exit pupil with a first rate of convergence and the second hologram converges the light to the second exit pupil with the same first rate of convergence.

12. A wearable heads-up display (“

WHUD”

) comprising;

a support structure that in use is worn on a head of a user;

a scanning laser projector carried by the support structure; and

a holographic combiner carried by the support structure, wherein the holographic combiner is positioned within a field of view of an eye of the user when the support structure is worn on the head of the user, and wherein the holographic combiner comprises at least one layer of holographic material and the at least one layer of holographic material includes;

a first hologram to receive light from the scanning laser projector and direct the light to a first exit pupil at or proximate the eye of the user, the first exit pupil having a first area; and

a second hologram to receive light from the scanning laser projector and direct the light to a second exit pupil at or proximate the eye of the user, the second exit pupil having a second area that is different from the first area.

13. The WHUD of claim 12 wherein the support structure has a general shape and appearance of an eyeglasses frame, and wherein the holographic combiner further comprises an eyeglass lens that carries the at least one layer of holographic material.

14. The WHUD of claim 12 wherein the first hologram and the second hologram are positioned and oriented with respect to one another to cause the first exit pupil and the second exit pupil to at least partially overlap with one another at the eye of the user.

15. The WHUD of claim 12 wherein the first hologram and the second hologram are positioned and oriented with respect to one another to cause the second exit pupil to encompass the first exit pupil at the eye of the user.

16. The WHUD of claim 12 wherein the first hologram and the second hologram are positioned and oriented with respect to one another to cause the first exit pupil and the second exit pupil to be completely spatially-separated from one another at the eye of the user.

17. The WHUD of claim 12 wherein the at least one layer of holographic material in the holographic combiner further includes at least one additional hologram, each additional hologram to receive light from the scanning laser projector and direct the light to a respective exit pupil at or proximate the eye of the user, and wherein each respective exit pupil has a respective area that is different from the area of at least one of the other exit pupils.

18. The WHUD of claim 12 wherein the first exit pupil has a first geometry and the second exit pupil has a second geometry that is different from the first geometry.

19. The WHUD of claim 12 wherein the first hologram and the second hologram of the holographic combiner are both multiplexed holograms that implement a same form of multiplexing, the form of multiplexing implemented by both the first hologram and the second hologram selected from a group consisting of:

angle multiplexing, wavelength multiplexing, angle and wavelength multiplexing, and spatial multiplexing.

20. The WHUD of claim 12 wherein the first hologram converges the light from the scanning laser projector to the first exit pupil with a first rate of convergence and the second hologram converges the light from the scanning laser projector to the second exit pupil with the same first rate of convergence

21. A method of operating a wearable heads-up display (“

WHUD”

), the WHUD including a scanning laser projector and a holographic combiner positioned within a field of view of an eye of a user when the WHUD is worn on a head of the user, the method comprising;

directing a first light signal towards the holographic combiner by the scanning laser projector;

redirecting the first light signal towards a first exit pupil that has a first area at or proximate the eye of the user by a first hologram of the holographic combiner;

directing a second light signal towards the holographic combiner by the scanning laser projector; and

redirecting the second light signal towards a second exit pupil that has a second area at or proximate the eye of the user by a second hologram of the holographic combiner, the second area different from the first area.

22. The method of claim 21 wherein:

redirecting the first light signal towards a first exit pupil that has a first area at or proximate the eye of the user by a first hologram of the holographic combiner includes converging the first light signal towards the first exit pupil that has the first area at or proximate the eye of the user by the first hologram of the holographic combiner; and

redirecting the second light signal towards a second exit pupil that has a second area at or proximate the eye of the user by a second hologram of the holographic combiner includes converging the second light signal towards the second exit pupil that has the second area at or proximate the eye of the user by the second hologram of the holographic combiner.

23. The method of claim 21 wherein converging the first light signal towards the first exit pupil that has the first area at or proximate the eye of the user by the first hologram of the holographic combiner includes converging the first light signal towards the first exit pupil with a first rate of convergence by the first hologram of the holographic combiner and converging the second light signal towards the second exit pupil includes converging the second light signal towards the second exit pupil with the same first rate of convergence by the second hologram of the holographic combiner.

24. The method of claim 21 wherein redirecting the second light signal towards a second exit pupil that has a second area at or proximate the eye of the user by a second hologram of the holographic combiner includes redirecting the second light signal towards a second exit pupil that at least partially overlaps with the first exit pupil at or proximate the eye of the user by the second hologram of the holographic combiner.

25. The method of claim 24 wherein redirecting the second light signal towards a second exit pupil that at least partially overlaps with the first exit pupil at or proximate the eye of the user by the second hologram of the holographic combiner includes redirecting the second light signal towards a second exit pupil that encompasses the first exit pupil at or proximate the eye of the user by the second hologram of the holographic combiner.

26. The method of claim 21, further comprising:

directing at least one additional light signal towards the holographic combiner by the scanning laser projector; and

redirecting each additional light signal towards a respective exit pupil at or proximate the eye of the user by a respective hologram of the holographic combiner, each respective exit pupil having a respective area that is different from the area of at least one of the other exit pupils.

28. The WHUD of claim 24 wherein the first exit pupil and the second exit pupil at least partially overlap with one another in the eyebox of the WHUD.

29. The WHUD of claim 24 wherein the second exit pupil encompasses the first exit pupil in the eyebox of the WHUD.

30. The WHUD of claim 24 wherein the first exit pupil and the second exit pupil are completely spatially-separated from one another and do not overlap in the eyebox of the WHUD.

31. The WHUD of claim 24 wherein the eyebox of the visual display further comprises at least one additional exit pupil, wherein each respective exit pupil has a respective area that is different from the area of at least one of the other exit pupils.

27. A wearable heads-up display (“

WHUD”

) comprising;

a support structure that in use is worn on a head of a user;

a display module carried by the support structure and operative to provide a visual display to the user, wherein the visual display has an eyebox that comprises;

a first exit pupil at or proximate an eye of the user, the first exit pupil having a first area; and

at least second exit pupil at or proximate the eye of the user, the second exit pupil having a second area that is different from the first area.