Calibration of stereoscopic display using waveguide combiner

Patent metadata

Field	Value
Publication number	US-12470686-B2
Application number	US-202318539216-A
Country	US
Kind code	B2
Filing date	Dec 13, 2023
Priority date	Jan 24, 2022
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

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 projection waveguide comprising a first optical path configured to transmit a first image for viewing; a second image projection waveguide comprising a second optical path configured to transmit a second image for viewing; an optical calibration system comprising
a third optical path configured to transmit a first calibration image, a portion of the third optical path being located in the first image projection waveguide and separate from the first optical path,
a fourth optical path configured to transmit a second calibration image, a portion of the fourth optical path being located in the second image projection waveguide and separate from the second optical path,
a waveguide combiner in which the third optical path and the fourth optical path combine into a shared optical path, and
a boresight sensor optically coupled to a common output coupler of the waveguide combiner, the boresight sensor configured to detect light traveling along the third optical path or the fourth optical path; and
a controller configured to adjust one or more of the first image or the second image based at least in part on an output of the boresight sensor.

2 . The device of claim 1 , wherein the boresight sensor comprises one or more of a camera, a quadrant diode detector, a lensless camera or an angular sensitive pixel detector.

3 . The device of claim 1 , further comprising a first image projector optically coupled to a first input coupler of the first image projection waveguide on the first optical path, and wherein the optical calibration system further comprises a first calibration image source optically coupled to a second input coupler of the first image projection waveguide on the third optical path.

4 . The device of claim 3 , wherein the first calibration image source comprises a calibration image output of the first image projector.

5 . The device of claim 3 , wherein the first calibration image source is separate from the first image projector.

6 . The device of claim 1 , wherein the first image projection waveguide comprises a first output coupler on the first optical path, and a second output coupler on the third optical path, the second output coupler being optically coupled to an input coupler of the waveguide combiner.

7 . 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.

8 . A head mounted display (HMD) device comprising:
a first image projection waveguide comprising a first optical path configured to transmit a first image for viewing; a second image projection waveguide comprising a second optical path configured to transmit a second image for viewing; and an optical calibration system comprising
a third optical path configured to transmit a first calibration image, a portion of the third optical path being located in the first image projection waveguide and separate from the first optical path,
a fourth optical path configured to transmit a second calibration image, a portion of the fourth optical path being located in the second image projection waveguide and separate from the second optical path,
a waveguide combiner in which the third optical path and the fourth 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 a common output coupler of the waveguide combiner, the boresight sensor configured to detect light traveling along the third optical path or the fourth optical path.

9 . The device of claim 8 , further comprising a controller configured to adjust one or more of the first image or the second image based at least in part on an output of the boresight sensor.

10 . The device of claim 8 , wherein the boresight sensor comprises one or more of a camera, a quadrant diode detector, a lensless camera or an angular sensitive pixel detector.

11 . The device of claim 8 , further comprising a first image projector optically coupled to a first input coupler of the first image projection waveguide on the first optical path, and wherein the optical calibration system further comprises a first calibration image source optically coupled to a second input coupler of the first image projection waveguide on the third optical path.

12 . The device of claim 11 , wherein the first calibration image source comprises a calibration image output of the first image projector.

13 . The device of claim 11 , wherein the first calibration image source is separate from the first image projector.

14 . The device of claim 8 , wherein the device is configured as a pair of glasses.

15 . A method enacted on a head mounted display (HMD) device comprising a first image projection waveguide including a first optical path, a second image projection waveguide including a second optical path, and an optical calibration system comprising a third optical path, a fourth optical path, a waveguide combiner, and a boresight sensor, the method comprising:
projecting a first calibration image along the third optical path that is spatially separated from the first optical path within the first image projection waveguide; projecting a second calibration image along the fourth optical path that is spatially separated from the second optical path within the second image projection waveguide; directing the first calibration image and the second calibration image to the waveguide combiner that combines the third optical path and the fourth optical path into a shared optical path; detecting an output of the shared optical path of the waveguide combiner via the boresight sensor, the output of the shared optical path comprising one or more of the first calibration image or the second calibration image; and adjusting one or more of a first image along the first optical path or a second image along the second optical path based at least in part on an output of the boresight sensor.

16 . The method of claim 15 , 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.

17 . The method of claim 15 , wherein the HMD device further includes an image projector comprising a calibration image output and a stereoscopic image output, and wherein projecting the first calibration image uses the calibration image output, and adjusting one or more of the first image along the first optical path or the second image along the second optical path comprises adjusting the first image using the stereoscopic image output.

Assignees

• Microsoft Technology Licensing Llc

Inventors

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

Classifications

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B2027/0134

  of stereoscopic type · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title

• H04N13/398

  Synchronisation thereof; Control thereof · CPC title

• H04N13/363

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