Display systems with waveguide configuration to mitigate rainbow effect

Patent metadata

Field	Value
Publication number	US-12339454-B2
Application number	US-202217674573-A
Country	US
Kind code	B2
Filing date	Feb 17, 2022
Priority date	Feb 17, 2022
Publication date	Jun 24, 2025
Grant date	Jun 24, 2025

Abstract

According to examples, a display system may include a wearable eyewear arrangement that may include a lens assembly having a projector to propagate display light associated with an image. The lens assembly may also include a waveguide configuration for propagating the display light to an eyebox. The waveguide configuration may include a volume Bragg grating (VBG) component for propagating the display light from a projector to an eyebox. The VBG component may include at least one tilt adjusted grating facilitated by adjustment in an original grating vector (k) direction of a grating by a pre-determined value. The tilt adjusted grating may facilitate to mitigate a rainbow effect observable in a gazing direction of the eyebox. The rainbow effect may be mitigated by modification of a rainbow ghost path away from the gazing direction without affecting propagation of the image pertaining to the display light.

First claim

The invention claimed is:

1. A display system, comprising:
a wearable eyewear arrangement, comprising:
a lens assembly comprising:
a projector to propagate display light associated with an image; and
a waveguide configuration comprising a volume Bragg grating (VBG) component for propagating the display light from a projector to an eyebox,
wherein the VBG component includes at least one tilt adjusted grating facilitated by adjustment in an original grating vector (k) direction of a grating by a pre-determined value, the pre-determined value pertaining to a change in a co-ordinate or a tilt axis pertaining to the original grating vector (k) direction of the grating,
wherein the tilt adjusted grating facilitates to mitigate a rainbow effect observable in a gazing direction of the eyebox, and
wherein the rainbow effect is mitigated by modification of a rainbow ghost path away from the gazing direction without affecting propagation of the image pertaining to the display light.

2. The display system of claim 1 , wherein the tilt adjusted grating includes the adjustment in the original grating vector (k) direction pertaining to at least one of an input grating, a middle grating or an output grating.

3. The display system of claim 2 , wherein the tilt adjusted grating mitigates the rainbow effect caused by an unexpected deviation of the rainbow ghost path by at least one of the output grating or the middle grating.

4. The display system of claim 2 , wherein the tilt adjusted grating mitigates a type-B rainbow effect that is a caused by a varied pitch response based upward deviation of collimated external light by the output grating, and wherein the tilt adjusted grating mitigates a crosstalk ghost rainbow effect that is caused by a downward deviation of the collimated external light by the middle grating.

5. The display system of claim 4 , wherein an extent of mitigation of the rainbow effect is tested by using a blocker between the waveguide configuration and the eyebox, and wherein the blocker blocks undeviated rays of the collimated external light.

6. The display system of claim 2 , wherein a partial tilting mitigates the rainbow effect caused by the output grating of the VBG component.

7. The display system of claim 1 , wherein the tilt adjusted grating is attained by partial tilting or flipping of the grating to change the co-ordinate or the tilt axis by the pre-determined value, based on type of the rainbow effect and requirements of the propagation of the image.

8. The display system of claim 7 , wherein the flipping mitigates the rainbow effect caused by the middle grating of the VBG component.

9. The display system of claim 1 , wherein the waveguide configuration comprises a single-layered or multi-layered VBG components.

10. The display system of claim 9 , wherein each VBG component includes a same or a different adjustment of the grating vector (k) direction of the corresponding tilt adjusted grating.

11. The display system of claim 1 , wherein reflection or diffraction characteristics of the rainbow ghost path are altered by the tilt adjusted grating in a direction above or below the gazing direction of the eyebox.

12. The display system of claim 1 , wherein each VBG component includes a same or a different adjustment of the grating vector (k) direction of the corresponding tilt adjusted grating.

13. An augmented reality (AR) system comprising:
a display system comprising a wearable eyewear arrangement that includes:
a lens assembly comprising:
a projector to propagate display light associated with an image; and
a waveguide configuration comprising a volume Bragg grating (VBG) component for propagating the display light from a projector to an eyebox,
wherein the VBG component includes at least one tilt adjusted grating facilitated by adjustment in an original grating vector (k) direction of a grating by a pre-determined value, the pre-determined value pertaining to a change in a co-ordinate or a tilt axis pertaining to the original grating vector (k) direction of the grating,
wherein the tilt adjusted grating facilitates to mitigate a rainbow effect observable in a gazing direction of the eyebox, and
wherein the rainbow effect is mitigated by modification of a rainbow ghost path away from the gazing direction without affecting propagation of the image pertaining to the display light.

14. The AR system of claim 13 , wherein the tilt adjusted grating includes the adjustment in the original grating vector (k) direction pertaining to at least one of an input grating, a middle grating or an output grating.

15. The AR system of claim 14 , wherein the tilt adjusted grating mitigates the rainbow effect caused by an unexpected deviation of the rainbow ghost path by at least one of the output grating or the middle grating.

16. The AR system of claim 14 , wherein the tilt adjusted grating is attained by partial tilting or flipping of the grating to change the co-ordinate or the tilt axis by the pre-determined value, based on a type of the rainbow effect and requirements of the propagation of the image.

17. The AR system of claim 13 , wherein the waveguide configuration comprises a single-layered or multi-layered VBG components.

18. A method comprising:
obtaining a waveguide configuration for implementation in a lens assembly, wherein the waveguide configuration comprises a volume Bragg grating (VBG) component;
adjusting, by a pre-determined value, an original grating vector (k) direction of a grating of the waveguide configuration to obtain at least one tilt adjusted grating, the pre-determined value pertaining to a change in a co-ordinate or a tilt axis pertaining to the original grating vector (k) direction of the grating; and
propagating, through the waveguide configuration, a display light to an eyebox, wherein the display light is associated with an image and is propagated to the waveguide configuration through a projector of the lens assembly,
wherein the tilt adjusted grating facilitates to mitigate a rainbow effect observable in a gazing direction of the eyebox, and wherein the rainbow effect is mitigated by modification of a rainbow ghost path away from the gazing direction without affecting propagation of the image pertaining to the display light.

19. The method of claim 18 , wherein the tilt adjusted grating includes the adjustment in the original grating vector (k) direction pertaining to at least one of an input grating, a middle grating or an output grating.

20. The method of claim 18 , wherein each VBG component includes a same or a different adjustment of the grating vector (k) direction of the corresponding tilt adjusted grating.

Assignees

• Meta Platforms Tech Llc

Inventors

• Lam Wai Sze Tiffany
• Yang Yang
• Meiser Dominic
• Chi Wanli

Classifications

• G02B2027/0138

  comprising image capture systems, e.g. camera · CPC title

• G02B2027/0116

  comprising devices for correcting chromatic aberration · CPC title

• G02B2027/011

  comprising device for correcting geometrical aberrations, distortion · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title