Three dimensional depth mapping using dynamic structured light

Patent metadata

Field	Value
Publication number	US-11962748-B2
Application number	US-202117339559-A
Country	US
Kind code	B2
Filing date	Jun 4, 2021
Priority date	Oct 23, 2013
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

Apparatus for generating a dynamic structured light pattern for optical tracking in three-dimensional space, comprises an array of lasers, such as a VCSEL laser array, to project light in a pattern into a three-dimensional space; and an optical element or elements arranged in cells. The cells are aligned with subsets of the laser array, and each cell individually applies a modulation, in particular an intensity modulation, to light from the laser or lasers of the subset, to provide a distinguishable and separately controllable part of the dynamic structured light pattern. A method of generating a structured light pattern is disclosed, in which light is provided from an array of lasers, and light is individually projected from subsets of the array of lasers to provide differentiated parts of the structured light pattern.

First claim

What is claimed is:

1. An optical cell comprising:
a plurality of different optical elements in optical series sharing an optical axis, the plurality of different optical elements aligned with a corresponding laser of an array of lasers and configured to apply a modulation to light previously emitted from the corresponding laser that later passes through each of the plurality of different optical elements forming a partial tile of a structured light pattern,
a last of the plurality of different optical elements in the optical series having a surface configured to shape the partial tile of the structured light pattern into a unique shape while projecting the partial tile of the structured light pattern for illuminating a portion of a scene, the unique shape depending on a preset random function that defines the surface.

2. The optical cell of claim 1 , wherein the plurality of different optical elements comprises an optical element configured to change a direction of the light emitted from the corresponding laser.

3. The optical cell of claim 2 , wherein the optical element is configured to change the direction of the light by diffracting the light.

4. The optical cell of claim 2 , wherein the optical element is configured to change the direction of the light by refracting the light.

5. The optical cell of claim 2 , wherein the optical element comprises features arranged in a saw tooth configuration that are configured to change the direction of the light by bending the light.

6. The optical cell of claim 1 , wherein the plurality of different optical elements comprises an optical element configured to focus the light emitted from the corresponding laser.

7. The optical cell of claim 6 , wherein the optical element comprises features arranged in a saw tooth configuration that is configured to focus the light to a focal point.

8. The optical cell of claim 1 , wherein the modulation is selected from a group consisting of: a diffractive modulation, a refractive modulation, and a combination of a diffractive and a refractive modulation.

9. The optical cell of claim 1 , wherein the plurality of different optical elements in the optical series comprises:
a first optical element configured to focus the light emitted from the corresponding laser;
a second optical element configured to generate bending light by changing a direction of the focused light; and
a third optical element configured to shape the bending light to generate the partial tile of the structured light pattern.

10. The optical cell of claim 1 , wherein a resolution of the portion of the scene corresponding to the partial tile of the structured light pattern is modified in accordance with the applied modulation.

11. The optical cell of claim 1 , wherein the array of lasers is selected from a group consisting of: individual lasers, pairs of lasers, triplets of lasers, combinations of different sizes of lasers, and dynamically changing combinations of lasers.

12. The optical cell of claim 1 , wherein the array of lasers and the last of the plurality of different optical elements are configured to project the partial tile into a three-dimensional space to track a three-dimension scene.

13. A method comprising:
controlling an optical cell comprising a plurality of different optical elements in optical series sharing an optical axis, the plurality of different optical elements aligned with a corresponding laser of an array of lasers to apply a modulation to light previously emitted from the corresponding laser that later passes through each of the plurality of different optical elements forming a partial tile of a structured light pattern; and
shaping, by a surface of a last of the plurality of different optical elements in the optical series, the partial tile of the structured light pattern into a unique shape while projecting the partial tile of the structured light pattern for illuminating a portion of a scene, the unique shape depending on a preset random function that defines the surface.

14. The method of claim 13 , further comprising:
changing a direction of the light emitted from the corresponding laser using an optical element of the plurality of different optical elements.

15. The method of claim 13 , further comprising:
focusing the light emitted from the corresponding laser to a focal point using an optical element of the plurality of different optical elements, the focal point depending on features of the optical element.

16. The method of claim 13 , further comprising:
focusing the light emitted from the corresponding laser;
changing a direction of the focused light to generate bending light; and
changing a shape of the bending light to generate the partial tile of the structured light pattern.

17. An apparatus comprising:
an optical cell comprising a plurality of different optical elements in optical series sharing an optical axis, the plurality of different optical elements aligned with a corresponding laser of an array of lasers and configured to apply a first modulation to light previously emitted from the corresponding laser that later passes through each of the plurality of different optical elements forming a partial tile of a structured light pattern, a last of the plurality of different optical elements in the optical series having a surface configured to shape the partial tile of the structured light pattern into a unique shape while projecting the partial tile of the structured light pattern for illuminating a portion of a scene, the unique shape depending on a preset random function that defines the surface; and
a processor configured to:
determine a second modulation different from the first modulation by analyzing captured light reflected from the scene, and
configure the optical cell to adjust a modulation of other light when the other light previously emitted from the corresponding laser later passes through each of the plurality of different optical elements to apply the second modulation to generate an adjusted version of the partial tile.

Assignees

• Meta Platforms Tech Llc

Inventors

• Romano Nitay
• Grossinger Nadav
• Alpern Yair
• Alon Emil

Classifications

• H04N13/296 Primary

  Synchronisation thereof; Control thereof · CPC title

• G01S7/4815

  using multiple transmitters · CPC title

• G01S17/46 Primary

  Indirect determination of position data · CPC title

• G01S17/89

  for mapping or imaging · CPC title

• G02B27/4205 Primary

  having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant · CPC title