FOCUS ADJUSTING HEADSET

• US 20170262054A1
• Filed: 03/10/2017
• Published: 09/14/2017
• Est. Priority Date: 03/11/2016
• Status: Active Grant

• Current Assignee: META Platforms Technologies LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Original Assignee: Oculus VR, LLC (Meta Platforms, Inc. (f/k/a Facebook, Inc.))
• Inventors: Lanman, Douglas Robert, Fix, Alexander Jobe, Matsuda, Nathan Seigo, Trail, Nicholas Daniel
• Granted Patent: US 11,106,276 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 2027/0129 comprising devices for correcting parallax
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0185 Displaying image at variable distance
• CPC Class Codes: G02B 27/0068 having means for controlling the degree of correction, e.g. using phase modulators, movable elements controlling the phase of light using moving or deformable elements G02B26/06
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G06F 1/163 Wearable computers, e.g. on a belt
• 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 3/012 Head tracking input arrangements
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06T 19/006 Mixed reality object pose determination, tracking or camera calibration for mixed reality G06T7/00

Abstract

A virtual reality (VR) headset adjusts the phase of light of a virtual scene received from a display element using a spatial light modulator (SLM) to accommodate changes in vergence for a user viewing objects in the virtual scene. The VR headset receives virtual scene data that includes depth information for components of the virtual scene and the SLM adjusts a wavefront of the light of the virtual scene by generating a phase function that adjusts the light of the virtual scene with phase delays based the depth values. Individual phase delays shift components of the virtual scene based on the depth values to a target focal plane to accommodate a user at a vergence depth for a frame of the virtual scene. Further, the SLM can provide optical defocus by shifting components of the virtual scene with the phase delays for depth of field blur.

Claims

1. A method comprising:

receiving, by a virtual reality headset, virtual scene data to display a virtual scene on an electronic display element of the virtual reality headset;

determining an eye position and gaze lines for each eye of a user wearing the virtual reality headset via images of each eye captured by an eye tracking system included in the virtual reality headset;

determining a vergence point for the user in the virtual scene based on an estimated intersection of the gaze lines for each eye of the user;

displaying the virtual scene on the electronic display element, the virtual reality headset including an optics block and a spatial light modulator (SLM) in optical series that receive a wavefront of light of the virtual scene displayed on the electronic display element; and

adjusting, via the SLM, the wavefront of the light from the electronic display element based at least in part on the determined vergence point for the user, the SLM directing the adjusted wavefront of the light of the virtual scene to the user via an exit pupil of the virtual reality headset.

2. The method of claim 1, further comprising:

generating, by the SLM, a phase function for the virtual scene based on the determined vergence point and depth values associated with the virtual scene, the phase function introducing phase delays into the wavefront of the light from the electronic display element.

3. The method of claim 2, wherein the phase function shifts the light from the electronic display element by introducing the phase delays for a target focal plane based on the determined vergence point and depth values of the virtual scene, and wherein the target focal plane is at least one of a continuously-varying shape or a discontinuous surface.

4. The method of claim 3, wherein the phase delays are applied based on the depth values relative to a depth value of the determined vergence point and provide optical defocus to the virtual scene based on each locations depth relative to the determined vergence point.

5. The method of claim 1, wherein each location in the virtual scene is associated with a depth value of the plurality of depth values via the virtual scene data, and wherein the focal pattern provides optical defocus to each location in the virtual scene based on the depth value for each location relative to the depth value of the determined vergence point.

6. The method of claim 5, wherein the focal pattern is generated to adjust a plane of focus of the virtual reality headset to the determined vergence point to provide accommodation at the determined vergence point.

7. The method of claim 5, further comprising:

adjusting a focal length of the optics block at least in part on the determined vergence point for the user, wherein adjusting the focal length of the optics block comprises;

changing a distance between the optics block and the electronic display element to accommodate the determined vergence point.

8. The method of claim 5, wherein the SLM adjusts the focal pattern in response to determining a new vergence point for the user.

9. A method comprising:

receiving, by a virtual reality headset, virtual scene data for displaying a virtual scene on an electronic display element of the virtual reality headset;

determining a position and an orientation of the virtual reality headset;

determining a portion of the virtual scene to display on the electronic display element based on the position and the orientation of the virtual reality headset;

displaying the portion of the virtual scene on the electronic display element, the virtual reality headset including a spatial light modulator (SLM) that receives a wavefront of light for the portion of the virtual scene displayed on the electronic display element; and

adjusting, via the SLM, the wavefront of the light received for the portion of the virtual scene displayed on the electronic display element based at least in part on a plurality of depth values associated with different locations within the portion of the virtual scene, the SLM directing the adjusted wavefront received from the electronic display element to an exit pupil of the virtual reality headset.

10. The method of claim 9, further comprising:

determining an updated position and an updated orientation of the virtual reality headset;

determining a updated portion of the virtual scene to display on the electronic display element based on the updated position and the updated orientation of the virtual reality headset;

displaying the updated portion of the virtual scene on the electronic display element; and

adjusting, via the SLM, the wavefront for the updated portion of the virtual scene based at least in part on the plurality of depth values associated with different locations within the updated portion of the virtual scene.

11. The method of claim 9, further comprising:

generating, by the SLM, a phase function to adjust the wavefront based on the plurality of depth values associated with the different locations within the portion of the virtual scene relative to a central depth value for the portion of the virtual scene, the central depth value associated with a location in the portion of the virtual scene corresponding to a target viewing area of the electronic display element, the phase function introducing phase delays to one or more portion of the wavefront of the light for the portion of the virtual scene from the electronic display element.

12. The method of claim 9, further comprising:

determining an eye position and gaze lines for each eye of a user wearing the virtual reality headset via images of each eye captured by an eye tracking system included in the virtual reality headset;

determining a vergence point for the user in the portion of the virtual scene based on an estimated intersection of the gaze lines for each eye of the user; and

adjusting, based at least in part on the determined vergence point, a focal length of an optics block in optical series with the SLM to provide accommodation for each eye of the user at the determined vergence point, wherein the wavefront is adjusted to provide optical defocus to at least one of the different locations in the portion of the virtual scene based on the plurality of depth values relative to a depth value associated with the determined vergence point.

13. The method of claim 9, wherein the adjusted wavefront adjusts a plane of focus of the virtual reality headset to a location in the portion of the virtual scene associated with a target viewing area of the electronic display element.

14. The method of claim 13, wherein each of the different locations within the virtual scene is associated with a depth value of the plurality of depth values including a depth value for the location associated with the target viewing area, the SLM adjusting the wavefront of the light from the electronic display element based on the depth value for each location in the portion of the virtual scene for each frame of the virtual scene displayed on the electronic display element, and wherein the wavefront provides optical defocus to at least one of the different locations in the portion of the virtual scene based on the depth value for each location relative to the depth value for the location associated with the target viewing area.

15. A virtual reality headset comprising:

at least one processor;

an eye tracking system including an image capturing element, the eye tracking system configured to determine an eye position of each eye of a user wearing the virtual reality headset and gaze lines for each eye of the user;

memory including instructions that, when executed by the at least one processor, cause the at least one processor to;

determine a viewing location of the user within the virtual scene based on an estimated intersection of the gaze lines for each eye;

an electronic display element configured to display a virtual scene; and

an optics block including a spatial light modulator (SLM) configured to;

receive light of the virtual scene displayed by the electronic display element, the light including a wavefront;

adjust the wavefront of the light for the virtual scene based at least in part on the viewing location of the user; and

direct the adjusted wavefront of the light to an exit pupil of the virtual reality headset, the adjusted wavefront providing optical defocus to the virtual scene based on the viewing location of the user.

16. The virtual reality headset of claim 15, wherein the adjusted wavefront moves a plane of focus of the virtual reality headset to the viewing location of the user to provide accommodation for each eye of the user at the viewing location.

17. The virtual reality headset of claim 15, wherein the SLM adjusts the wavefront in response to determining a new viewing location of the user.

18. The virtual reality headset of claim 15, further comprising:

a varifocal actuation block configured to change a focal length of the optics block based at least in part on the viewing location of the user, wherein the adjusted wavefront provides the optical defocus to different locations in the virtual scene based on a depth value associated with each of the different locations relative to a depth value associated with the viewing location of the user.

19. The virtual reality headset of claim 15, wherein the SLM operates in phase-modulation mode.

20. The virtual reality headset of claim 19, wherein the SLM generates a phase function based on depth values associated with the virtual scene including a depth value associated with the viewing location of the user, the phase function introducing phase delays to one or more portions of the wavefront the light from the electronic display element to adjust the wavefront to provide the optical defocus.