Systems, devices, and methods for eyeboxes with heterogeneous exit pupils

• US 10,197,805 B2
• Filed: 05/03/2016
• Issued: 02/05/2019
• Est. Priority Date: 05/04/2015
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: North Inc. (Alphabet Inc.)
• Inventors: Bailey, Matthew, Alexander, Stefan, Morrison, Vance R., Mahon, Thomas, Holland, Lloyd Frederick, Choi, Jaehong
• Primary Examiner(s): Chwasz, Jade R
• Application Number:
  US15/145,583
• Publication Number:
  US 20160327796A1
• Time in Patent Office: 1,008 Days
• Field of Search: 359 3, 359 9, 359 10, 359 11, 359 13, 359 14, 359 15, 359 21, 359 22, 359 24, 359 27, 359 32, 359 35
• 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 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, the scanning laser projector to generate display content; 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, the holographic combiner to receive display content from the scanning laser projector and redirect the display content towards the 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 converge the display content to a first exit pupil at the eye of the user, the first exit pupil having a first area at the eye of the user that is smaller than an entrance pupil of the eye of the user when the support structure is worn on the head of the user, the first exit pupil to provide a first field of view that includes an entire display area of the display content to the eye of the user; and

a second hologram to converge the display content to a second exit pupil at the eye of the user, the second exit pupil having a second area at the eye of the user, wherein the second area of the second exit pupil is larger than the first area of the first exit pupil at the eye of the user and larger than an entrance pupil of the eye of the user when the support structure is worn on the head of the user, the second exit pupil to provide a second field of view that includes only a portion of the display area of the display content to the eye of the user, the display area of the display content extending outside of the second field of view of the second exit pupil, and wherein the first exit pupil and the second exit pupil at least partially overlap with one another at the eye of the user.

2. The WHUD of claim 1 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.

3. The WHUD of claim 1 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 WHUD of claim 1 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 display content from the scanning laser projector and converge the display content to a respective exit pupil at the eye of the user, and wherein each respective exit pupil has a respective area at the eye of the user that is different from the area of at least one of the other exit pupils at the eye of the user.

5. The WHUD 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.

6. The WHUD of claim 1 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.

7. The WHUD of claim 1 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.

8. 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, by a first hologram of the holographic combiner, the first light signal towards a first exit pupil that has a first area at the eye of the user, the first area of the first exit pupil smaller than an entrance pupil of the eye of the user to provide a first field of view that includes an entire display area of virtual content to the eye of the user;

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

redirecting, by a second hologram of the holographic combiner, the second light signal towards a second exit pupil that has a second area at the eye of the user, the second area larger than the first area at the eye of the user and the second area larger than the entrance pupil of the eye of the user to provide a second field of view that includes only a portion of the display area of the virtual content to the eye of the user, the display area of the virtual content extending outside of the second field of view of the second exit pupil, wherein the first exit pupil and the second exit pupil at least partially overlap with one another at the eye of the user.

9. The method of claim 8 wherein:

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

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

10. The method of claim 9 wherein converging, by the first hologram of the holographic combiner, the first light signal towards the first exit pupil that has the first area at the eye of the user includes converging, by the first hologram of the holographic combiner, 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, by the second hologram of the holographic combiner, the second light signal towards the second exit pupil includes converging, by the second hologram of the holographic combiner, the second light signal towards the second exit pupil with the same first rate of convergence by the second hologram of the holographic combiner.

11. The method of claim 8 wherein redirecting, by a second hologram of the holographic combiner, the second light signal towards a second exit pupil that has a second area at the eye of the user includes redirecting, by the second hologram of the holographic combiner, the second light signal towards a second exit pupil that encompasses the first exit pupil at the eye of the user.

12. The method of claim 8, 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 the eye of the user by a respective hologram of the holographic combiner, each respective exit pupil having a respective area at the eye of the user that is different from the area of at least one of the other exit pupils at the eye of the user.

13. 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 an eye of the user, the first exit pupil having a first area at the eye of the user that is smaller than an entrance pupil of the eye of the user, the first exit pupil to provide a first field of view that includes an entire display area of the visual display to the eye of the user; and

at least a second exit pupil at the eye of the user, the second exit pupil having a second area at the eye of the user that is larger than the first area of the first exit pupil at the eye of the user and larger than the entrance pupil of the eye of the user, the second exit pupil to provide a second field of view that includes only a portion of the display area of the visual display to the eye of the user, the display area of the virtual display extending outside of the second field of view of the second exit pupil, and wherein the first exit pupil and the second exit pupil at least partially overlap with one another in the eyebox of the WHUD.

14. The WHUD of claim 13 wherein the second exit pupil encompasses the first exit pupil in the eyebox of the WHUD.

15. The WHUD of claim 13 wherein the eyebox of the visual display further comprises at least one additional exit pupil, wherein each respective exit pupil has a respective area at the eye of the user that is different from the area of at least one of the other exit pupils at the eye of the user.