MULTIBEAM DIFFRACTION GRATING-BASED NEAR-EYE DISPLAY

• US 20180227576A1
• Filed: 04/03/2018
• Published: 08/09/2018
• Est. Priority Date: 10/16/2015
• Status: Active Grant

• Current Assignee: LEIA SPV LLC
• Original Assignee: Leia Inc.
• Inventors: Fattal, David A.
• Granted Patent: US 10,728,533 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 2027/0127 comprising devices increasing the depth of field
• CPC Class Codes: G02B 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/4205 having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
• CPC Class Codes: G02B 30/36 using refractive optical elements, e.g. prisms, in the optical path between the images and the observer
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: H04N 13/32 using arrays of controllable light sources; using moving apertures or moving light sources
• CPC Class Codes: H04N 13/324 Colour aspects
• CPC Class Codes: H04N 13/344 with head-mounted left-right displays
• CPC Class Codes: H04N 13/351 for displaying simultaneously
• CPC Class Codes: H04N 2213/001 Constructional or mechanical details

Abstract

A near-eye display and a binocular near-eye display system provide a plurality of different views of an image to different locations within an eye box to impart focus depth cues to a user. The near-eye display includes a multibeam diffraction grating-based display configured to provide the different views and an optical system configured to relay the different views to the different locations within the eye box. The binocular near-eye display system includes a pair of the multibeam diffraction grating-based displays and a binocular optical system configured to provide and relay a stereoscopic image pair representing a three-dimensional (3D) scene to a corresponding pair of laterally displaced eye boxes.

Claims

1. A near-eye display comprising:

a multibeam diffraction grating-based display configured to provide a plurality of different views of an image; and

an optical system configured to relay the plurality of different views of the image to a corresponding plurality of different locations within an eye box at an output of the near-eye display, the corresponding plurality of different locations within the eye box being configured to impart focus depth cues to a user of the near-eye display.

2. The near-eye display of claim 1, wherein the image comprises a three-dimensional (3D) image, and wherein different views of the plurality of different views represent different perspective views of the 3D image.

3. The near-eye display of claim 1, wherein the plurality of different views of the image includes at least four different views.

4. The near-eye display of claim 1, wherein the plurality of different views has a total angular extent and the optical system has an input aperture, the total angular extent being configured to substantially correspond to a size of the input aperture.

5. The near-eye display of claim 1, wherein the optical system comprises a simple magnifier configured to provide a virtual image of the image at a distance from the eye box corresponding to a normal accommodation range of an eye of a user.

6. The near-eye display of claim 1, wherein both of the multibeam diffraction grating-based display and the optical system are located within a field-of-view (FOV) of a user to substantially block a portion of the FOV, the near-eye display being a virtual reality display configured to supplant a view of a physical environment with the image within the blocked FOV portion.

7. The near-eye display of claim 1, wherein the multibeam diffraction grating-based display is located outside of a field-of-view (FOV) of a user, the optical system being located within the FOV, the near-eye display being an augmented reality display configured to augment a view of a physical environment in the FOV with the image.

8. The near-eye display of claim 1, wherein the optical system comprises a freeform prism.

9. The near-eye display of claim 8, wherein the optical system further comprises a freeform compensation lens.

10. The near-eye display of claim 1, wherein the multibeam diffraction grating-based display comprises:

a plate light guide configured to guide a collimated light beam at a non-zero propagation angle; and

an array of multibeam diffraction gratings at a surface of the plate light guide, a multibeam diffraction grating of the array being configured to diffractively couple out a portion of the guided collimated light beam as a plurality of coupled-out light beams having different principal angular directions that correspond to view directions of the plurality of different views of the image.

11. The near-eye display of claim 10, wherein the multibeam diffraction grating is a linearly chirped diffraction grating.

12. The near-eye display of claim 10, wherein the multibeam diffraction grating-based display further comprises:

a light source configured provide the collimated light beam to plate light guide; and

a light valve array adjacent to the plate light guide surface, the light valve array being configured to selectively modulate the coupled-out light beams as a plurality of pixels corresponding to of the plurality of different views of the image.

13. The near-eye display of claim 12, wherein the light source comprises a plurality of different optical sources configured to provide different colors of light, the different optical sources being configured to provide different, color-specific, non-zero propagation angles of collimated guided light beams corresponding to each of the different colors of light.

14. A near-eye binocular display system comprising a pair of the near-eye display of claim 1, wherein a first near-eye display of the pair is configured to provide a first plurality of different views of a first image to a first eye box, a second near-eye display of the pair being configured to provide a second plurality of different views of a second image to a second eye box, the second eye box being laterally offset from the first eye box, the first image and the second image representing a stereoscopic pair of images.

15. A near-eye binocular display system comprising:

a pair of multibeam diffraction grating-based displays, each multibeam diffraction grating-based display being configured to provide a different image of a pair of stereoscopic images representing a three-dimensional (3D) scene; and

a binocular optical system configured to separately relay the different images of the stereoscopic image pair to a corresponding pair of eye boxes, the eye boxes being laterally displaced from one another,

wherein a multibeam diffraction grating-based display of the display pair comprises a plate light guide and an array of multibeam diffraction gratings, a multibeam diffraction grating of the array being configured to diffractively couple out guided light from within the plate light guide as a plurality of coupled-out light beams, the coupled-out light beam plurality being configured to provide the different image of the stereoscopic image pair.

16. The near-eye binocular display system of claim 15, wherein each of the different images of the stereoscopic image pair comprises a plurality of different views of the 3D scene, the coupled-out light beams of the plurality having different principal angular directions corresponding to 3D view directions of the different views of the coupled-out light beam plurality.

17. The near-eye binocular display system of claim 16, wherein the binocular optical system is configured to relay the plurality of different views to a corresponding plurality of different locations within the eye boxes, the different locations of the different views within the eye boxes being configured to provide depth focus cues to a user of the near-eye binocular display system, the depth focus cues corresponding to binocular disparity between the different images of the stereoscopic image pair.

18. The near-eye binocular display system of claim 15, wherein the binocular optical system comprises a first freeform prism and a second freeform prism, the first freeform prism being configured to relay an image provided by a first multibeam diffraction grating-based display of the multibeam diffraction grating-based display pair to a first eye box of the eye box pair, the second freeform prism being configured to relay a different image provided by a second multibeam diffraction grating-based display of the multibeam diffraction grating-based display pair to a second eye box of the eye box pair.

19. The near-eye binocular display system of claim 18, wherein the binocular optical system further comprises a pair of freeform compensation lenses configured to provide different images of a physical environment to the pair of eye boxes, the near-eye binocular display system being an augmented reality display system.

20. The near-eye binocular display system of claim 15, wherein the provided different images of the stereoscopic image pair are configured supplant a binocular view of a physical environment within the eye boxes, the near-eye binocular display system being configured as a virtual reality display system.

21. The near-eye binocular display system of claim 15, wherein the multibeam diffraction grating-based display further comprises:

a light source configured to provide light;

an optical collimator configured to collimate the light provided by the light source; and

an array of light valves adjacent to the plate light guide, the light valve array being configured to selectively modulate the coupled-out light beams as a plurality of pixels corresponding to pixels of the provided image of the stereoscopic image pair,

wherein the plate light guide is configured to guide the collimated light at a non-zero propagation angle as a collimated light beam.

22. A method of near-eye image display operation, the method comprising:

guiding a collimated light beam in a light guide at a non-zero propagation angle;

diffractively coupling out a portion of the guided collimated light beam from the light guide using a multibeam diffraction grating to produce a plurality of coupled-out light beams directed away from the light guide at different principal angular directions to form a light field, the light field providing a plurality of different views of an image corresponding to the different principal angular directions of the coupled-out light beams; and

relaying the plurality of different views of the image to an eye box using an optical system.

23. The method of near-eye image display operation of claim 22, wherein relaying the plurality of different views relays different ones of the different views to different locations within the eye box, the different locations of different views affording depth focus cues to a user viewing the image in the eye box.

24. The method of near-eye image display operation of claim 22, wherein relaying the plurality of different views of the image comprises magnifying the image to provide a virtual image located at a distance from the eye box corresponding to a normal accommodation range of an eye of a user.

25. The method of near-eye image display operation of claim 22, wherein relaying the plurality of different views of the image provides one or both of an augmented reality display and a virtual reality display of the image.