Calibration of stereoscopic display using waveguide combiner

Patent metadata

Field	Value
Publication number	US-11876952-B2
Application number	US-202217648794-A
Country	US
Kind code	B2
Filing date	Jan 24, 2022
Priority date	Jan 24, 2022
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

Examples are disclosed that relate to calibration of a stereoscopic display system of an HMD via an optical calibration system comprising a waveguide combiner. One example provides an HMD device comprising a first image projector and a second image projector configured to project a stereoscopic image pair, and an optical calibration system. The optical calibration system comprises a first optical path indicative of an alignment of the first image projector, a second optical path indicative of an alignment of the second image projector, a waveguide combiner in which the first and second optical paths combine into a shared optical path, and one or more boresight sensors configured to detect calibration image light traveling along one or more of the first optical or the second optical path.

First claim

The invention claimed is:

1. A head mounted display (HMD) device comprising:
a first image projector configured to project a first image of a stereoscopic image pair;
a second image projector configured to project a second image of the stereoscopic image pair;
an optical calibration system comprising
a first optical path indicative of an alignment of the first image projector,
a second optical path indicative of an alignment of the second image projector,
a waveguide combiner in which the first optical path and the second optical path combine into a shared optical path, and
one or more boresight sensors, each boresight sensor configured to detect calibration image light traveling along one or more of the first optical path or the second optical path; and

a controller configured to adjust one or more of the first image of the stereoscopic image pair and the second image of the stereoscopic image pair based at least in part on an output of the one or more boresight sensors.

2. The device of claim 1 , wherein the one or more boresight sensors comprises a sensor configured to detect a first calibration image and a second calibration image delivered via the shared optical path.

3. The device of claim 2 , wherein the sensor comprises one or more of a camera, a quadrant diode detector, lensless camera or an angular sensitive pixel detector.

4. The device of claim 2 , wherein the optical calibration system further comprises a first calibration image source configured to output the first calibration image along the first optical path, and a second calibration image source configured to output the second calibration image along the second optical path.

5. The device of claim 4 , wherein the first calibration image source comprises a calibration image output of the first image projector, and wherein the second calibration image source comprises a calibration image output of the second image projector.

6. The device of claim 4 , wherein the first calibration image source is separate from the first image projector, and wherein the second calibration image source is separate from the second image projector.

7. The device of claim 2 , wherein the controller is configured to control projection of the first calibration image and the second calibration image in a time multiplexed manner.

8. The device of claim 4 , wherein the first calibration image source and the second calibration image source are configured to output infrared light.

9. The device of claim 1 , wherein the optical calibration system further comprises a calibration image source configured to output a calibration image along the shared optical path, and wherein the one or more boresight sensors comprises a first boresight sensor configured to detect the calibration image output from the first optical path, and a second boresight sensor configured to detect the calibration image output from the second optical path.

10. The device of claim 1 , wherein the device is configured as a pair of glasses, and wherein the waveguide combiner is located in a nose bridge of the pair of glasses.

11. The device of claim 10 , further comprising an image projection waveguide configured to transmit at least the first image of the stereoscopic image pair for viewing, and wherein a portion of the first optical path of the optical calibration system is located within the image projection waveguide.

12. A head mounted display (HMD) device comprising:
a first image projector configured to project a first image of a stereoscopic image pair;
a second image projector configured to project a second image of the stereoscopic image pair;
an optical calibration system comprising
a first calibration image source configured to output a first calibration image along a first optical path indicative of an alignment of the first image projector,
a second calibration image source configured to output a second calibration image along a second optical path indicative of an alignment of the second image projector,
a waveguide combiner in which the first optical path and the second optical path combine into a shared optical path, the waveguide combiner being positioned in a nose bridge of the HMD device, and
a boresight sensor optically coupled to an output coupler of the waveguide combiner, the boresight sensor configured to detect the first calibration image and the second calibration image; and

a controller configured to adjust one or more of the first image of the stereoscopic image pair and the second image of the stereoscopic image pair based at least in part on an output of the boresight sensor.

13. The device of claim 12 , wherein the boresight sensor comprises one or more of a camera, a quadrant diode detector, lensless camera or an angular sensitive pixel detector.

14. The device of claim 12 , wherein the first calibration image source and the second calibration image source are configured to output infrared light.

15. The device of claim 12 , wherein the device is configured as a pair of glasses.

16. The device of claim 15 , further comprising an image projection waveguide configured to transmit at least the first image of the stereoscopic image pair for viewing, and wherein a portion of the first optical path of the optical calibration system is located within the image projection waveguide.

17. The device of claim 16 , wherein the first optical path is spatially separated from an optical path configured for transmission of the first image of the stereoscopic image pair.

18. A method enacted on a head mounted display (HMD) device comprising a first image projector, a second image projector, a controller, and an optical calibration system comprising a first optical path, a second optical path, a waveguide combiner that combines the first optical path and the second optical path into a shared optical path, and a boresight sensor, the method comprising:
projecting a first calibration image along the first optical path;
projecting a second calibration image along the second optical path;
directing the first calibration image and the second calibration image to the waveguide combiner;
detecting an output of the shared optical path of the waveguide combiner via the boresight sensor, the output of the shared optical path comprising the first calibration image and the second calibration image; and
adjusting one or more of a first image of a stereoscopic image pair and a second image of the stereoscopic image pair based at least in part on an output of the boresight sensor.

19. The method of claim 18 , wherein projecting the first calibration image and projecting the second calibration image comprises projecting infrared light.

20. The method of claim 18 , wherein projecting the first calibration image and projecting the second calibration image comprises projecting the first calibration image and the second calibration image in a time multiplexed manner.

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Churin Dmitriy
• Johnson Parry Byron
• Reshidko Dmitry
• Wan Congshan

Classifications

• H04N13/327 Primary

  Calibration thereof · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title

• H04N13/341

  using temporal multiplexing · CPC title

• H04N13/344

  with head-mounted left-right displays · CPC title

• H04N13/363

  using image projection screens (volumetric display H04N13/388) · CPC title