Display assembly using dynamic liquid crystal array

• US 10,359,845 B1
• Filed: 05/01/2018
• Issued: 07/23/2019
• Est. Priority Date: 05/01/2018
• Status: Active Grant

• Current Assignee: META Platforms Technologies LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Original Assignee: Facebook Technologies, LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Inventors: Sulai, Yusufu Njoni Bamaxam, Gollier, Jacques, Geng, Ying, Wheelwright, Brian
• Primary Examiner(s): Lao, Lunyi
• Assistant Examiner(s): Casarez, Benjamin X
• Application Number:
  US15/968,589
• Time in Patent Office: 448 Days
• Field of Search: None
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 27/00 Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02F 1/29 for the control of the position or the direction of light beams, i.e. deflection
• CPC Class Codes: G02F 2203/24 beam steering
• CPC Class Codes: G02F 2203/50 Phase-only modulation
• CPC Class Codes: G06F 1/163 Wearable computers, e.g. on a belt
• CPC Class Codes: G06F 1/3231 Monitoring the presence, absence or movement of users
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A head-mounted display includes an electronic display, a liquid crystal (LC) array with LC cells forming a dynamic lens array, an optical assembly, an eye tracker, and a controller. The LC array refracts image light emitted from the electronic display. The LC array includes a gaze region with a subset of the LC cells forming a portion of the dynamic lens array having a lens density different than that associated with remaining portions of the LC cells outside the gaze region. The eye tracker tracks a gaze location corresponding to a foveal region of a user'"'"'s eye. The controller generates emission instructions and provides the emission instructions to the LC array to change location of the gaze region in the LC array based on the tracked gaze location. The optical assembly directs portions of image light refracted by the gaze region toward the foveal region of the user'"'"'s eye.

Claims

1. A head-mounted display (HMD) comprising:

a display assembly comprising an electronic display and a liquid crystal (LC) array,

wherein

the electronic display is configured to emit image light, and

the LC array includes a plurality of LC cells positioned in front of the electronic display and is configured to refract the image light received from the electronic display, a dynamic lens array formed by the LC cells, a gaze region of the LC array comprising a subset of the LC cells forming a portion of the dynamic lens array having a lens density different than one or more other lens densities of one or more other portions of the dynamic lens array associated with remaining portions of the LC cells outside the gaze region, the lens density controlled by controlling sizes of diameters of lenses formed by the subset of the LC cells;

an eye tracker configured to track a gaze location corresponding to a foveal region of a user'"'"'s eye, wherein a location of the gaze region in the LC array changes based on the tracked gaze location; and

an optical assembly configured to direct the image light refracted by the LC array to an eye box of the HMD corresponding to a location of the user'"'"'s eye.

2. The HMD of claim 1, wherein the HMD further comprises a controller coupled to the eye tracker and the LC array, the controller configured to:

receive information about the tracked gaze location from the eye tracker;

generate emission instructions based on the information about the tracked gaze location; and

provide the emission instructions to the LC array to change the location of the gaze region in the LC array in accordance with the tracked gaze location.

3. The HMD of claim 1, wherein the HMD further comprises a controller coupled to the eye tracker and the LC array, the controller configured to:

control phase functions of one or more subsets of the LC cells to generate the gaze region of the LC array tracking the gaze location, based on information about the tracked gaze location from the eye tracker.

4. The HMD of claim 1, wherein the lens density of the portion of the dynamic lens array associated with the gaze region of the LC array is higher than the one or more other lens densities of the one or more other portions of the dynamic lens array.

5. The HMD of claim 1, wherein the HMD further comprises a controller coupled to the eye tracker and the LC array, the controller configured to:

determine mapping between a plurality of regions of the LC array and different gaze locations of the user'"'"'s eye; and

store information about the mapping in a memory coupled to the controller.

6. The HMD of claim 5, wherein the controller is further configured to:

provide emission instructions to the LC array to change the location of the gaze region in the LC array to one of the plurality of regions, based on the tracked gaze location and the information about the mapping.

7. The HMD of claim 1, wherein the LC array is configured to provide optical correction to the image light such that a portion of the image light refracted by the subset of the LC cells in the gaze region of the LC array is in focus at the user'"'"'s eye.

8. The HMD of claim 7, wherein the optical assembly is configured to direct the portion of the image light toward the foveal region of the user'"'"'s eye.

9. The HMD of claim 1, wherein a portion of the image light refracted by the remaining portions of the LC cells outside the gaze region of the LC array is not in focus at the user'"'"'s eye.

10. The HMD of claim 9, wherein the optical assembly is configured to direct the portion of the image light toward a region of the user'"'"'s eye outside the foveal region.

11. A head-mounted display (HMD) comprising:

an electronic display configured to emit image light;

a liquid crystal (LC) array including a plurality of LC cells positioned in front of the electronic display and configured to refract the image light received from the electronic display, a dynamic lens array formed by the LC cells, a gaze region of the LC array comprising a subset of the LC cells forming a portion of the dynamic lens array having a lens density different than one or more other lens densities of one or more other portions of the dynamic lens array associated with remaining portions of the LC cells outside the gaze region, the lens density controlled by controlling sizes of diameters of lenses formed by the subset of the LC cells;

an eye tracker configured to track a gaze location corresponding to a foveal region of a user'"'"'s eye;

a controller coupled to the eye tracker and the LC array, the controller configured to;

generate emission instructions based on information about the tracked gaze location, and

provide the emission instructions to the LC array to change a location of the gaze region in the LC array in accordance with the tracked gaze location; and

an optical assembly configured to direct the image light refracted by the LC array to an eye box of the HMD corresponding to a location of the user'"'"'s eye.

12. The HMD of claim 11, wherein the lens density of the portion of the dynamic lens array associated with the gaze region of the LC array is higher than the one or more other lens densities of the one or more other portions of the dynamic lens array.

13. The HMD of claim 11, wherein:

the LC array is configured to provide optical correction to the image light such that a portion of the image light refracted by the subset of the LC cells in the gaze region of the LC array is in focus at the user'"'"'s eye, and

the optical assembly is configured to direct the portion of the image light toward the foveal region of the user'"'"'s eye.

14. The HMD of claim 11, wherein the controller is further configured to:

control phase functions of one or more subsets of the LC cells to generate the gaze region of the LC array tracking the gaze location, based on information about the tracked gaze location from the eye tracker.

15. The HMD of claim 11, wherein the controller is further configured to:

determine mapping between a plurality of regions of the LC array and different gaze locations of the user'"'"'s eye; and

store information about the mapping in a memory coupled to the controller.

16. The HMD of claim 15, wherein the controller is further configured to:

provide the emission instructions to the LC array to change the location of the gaze region in the LC array to one of the plurality of regions, based on the tracked gaze location and the information about the mapping.

17. A method of controlling a head-mounted display (HMD), the method comprising:

tracking a gaze location corresponding to a foveal region of a user'"'"'s eye;

generating emission instructions based in part on the tracked gaze location;

providing the emission instructions to a liquid crystal (LC) array including a plurality of LC cells configured to refract image light emitted from an electronic display of the HMD toward an eye box corresponding to a location of the user'"'"'s eye, a dynamic lens array formed by the LC cells, a gaze region of the LC array comprising a subset of the LC cells forming a portion of the dynamic lens array having a lens density based in part on the emission instructions different than one or more other lens densities of one or more other portions of the dynamic lens array associated with remaining portions of the LC cells outside the gaze region, the lens density controlled by controlling sizes of diameters of lenses formed by the subset of the LC cells;

providing the emission instructions to the LC array to change a location of the gaze region in the LC array in accordance with the tracked gaze location; and

directing the image light refracted by the LC array to an eye box of the HMD corresponding to a location of the user'"'"'s eye.

18. The method of claim 17, wherein a portion of the image light refracted by the subset of the LC cells in the gaze region of the LC array is in focus at the user'"'"'s eye.

19. The method of claim 17, further comprising:

determining mapping between a plurality of regions of the LC array and different gaze locations of the user'"'"'s eye; and

providing the emission instructions to the LC array to change the location of the gaze region in the LC array to one of the plurality of regions, based on the tracked gaze location and information about the mapping.