Illumination modules that emit structured light

• US 9,443,310 B2
• Filed: 10/09/2013
• Issued: 09/13/2016
• Est. Priority Date: 10/09/2013
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Hudman, Joshua, Masalkar, Prafulla
• Primary Examiner(s): Patel, Jay
• Assistant Examiner(s): HUANG, FRANK F
• Application Number:
  US14/050,106
• Publication Number:
  US 20150097947A1
• Time in Patent Office: 1,070 Days
• US Class Current: 1/1
• CPC Class Codes: A63F 13/213 comprising photodetecting means, e.g. cameras, photodiodes or infrared cells A63F13/219, A63F13/655 take precedence
• CPC Class Codes: A63F 13/49 Saving the game status; Pausing or ending the game
• CPC Class Codes: A63F 13/816 Athletics, e.g. track-and-field sports
• CPC Class Codes: A63F 13/833 Hand-to-hand fighting, e.g. martial arts competition A63F13/837 takes precedence
• CPC Class Codes: A63F 13/87 Communicating with other players during game play, e.g. by e-mail or chat
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4815 using multiple transmitters
• CPC Class Codes: G01S 7/4818 using optical fibres
• CPC Class Codes: G01S 7/4863 Detector arrays, e.g. charge-transfer gates
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 27/0922 the semiconductor light source comprising an array of light emitters
• CPC Class Codes: G02B 27/425 in illumination systems mask illumination systems in photolithographic systems G03F7/70158
• CPC Class Codes: G06T 7/50 Depth or shape recovery
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects

Abstract

A depth camera includes an illumination module and an image detector module. The illumination module outputs structured light that illuminates a capture area. The image detector module captures an image of the structured light as reflected from object(s) within the capture area. The illumination module includes a VCSEL array and optical element(s), such as projection optics, an MLA or DOE, or combinations thereof. Projection optics receive a light pattern emitted by the VCSEL array and project the light pattern. An optical element, downstream from the projection optics, can cause a total number of features included in the structured light to be greater than the number of features included in the light pattern projected by the projection optics. In an embodiment, a pitch of an MLA is offset relative to a pitch of the VCSEL array. Various structures can include alignment elements to aid manufacture of the illumination module.

Claims

1. A depth camera system, comprising:

an illumination module configured to output structured light that illuminates a capture area; and

an image detector module configured to capture an image of the structured light as reflected from one or more objects within the capture area;

the illumination module including

a VCSEL array comprising a plurality of vertical cavity surface emitting lasers (VCSELs), wherein each of the VCSELs is configured to emit a separate beam of light, and wherein the plurality of VCSELs are configured to collectively emit a light pattern; and

projection optics configured to receive the light pattern emitted by the VCSELs of the VCSEL array and project the light pattern;

wherein the structured light output by the illumination module is created at least in part based on the light pattern projected by the projection optics;

wherein the projection optics include

a field lens that is positioned adjacent the VCSEL array and configured to receive the beams of light emitted by the VCSELs of the VCSEL array and converge the beams to a single pupil; and

an objective lens that is positioned adjacent the field lens at the single pupil and configured to receive the converged beams from the field lens and diverge the beams to produce the light pattern projected by the projection optics.

2. The depth camera system of claim 1, wherein:

the light pattern projected by the projection optics include a number of features; and

the illumination module also includes an optical element that is positioned optically downstream from the projection optics and configured to cause a total number of features included in the structured light output by the illumination module to be greater than the number of features included in the light pattern projected by the projection optics.

3. The depth camera system of claim 2, wherein the optical element, that is positioned optically downstream from the projection optics, comprises a beam splitter that is configured to cause the total number of features included in the structured light output by the illumination module to be twice the number of features included in the light pattern projected by the projection optics.

4. The depth camera system of claim 2, wherein the optical element, that is positioned optically downstream from the projection optics, comprises a diffractive optical element (DOE) that is configured to cause the total number of features included in the structured light output by the illumination module to be an integer multiple of the number of features included in the light pattern projected by the projection optics.

5. The depth camera system of claim 4, wherein the diffractive optical element (DOE) is configured to cause the total number of features included in the structured light output by the illumination module to be twice or thrice the number of features included in the light pattern projected by the projection optics.

6. The depth camera system of claim 1, further comprising:

one or more processors configured to produce a depth image in dependence on the image captured by the image detector module.

7. The depth camera system of claim 6, wherein the one or more processors is/are also configured to update an application based on the depth image.

8. The depth camera system of claim 1, wherein the VCSEL array comprises an X-by-Y two dimensional array of VCSELs on a single semiconductor substrate.

9. A method, comprising:

emitting a separate beam of light from each of a plurality of vertical cavity surface emitting laser (VCSELs) of a VCSEL array to thereby collectively emit a light pattern;

receiving the beams of light emitted by the VCSELs of the VCSEL array, at a field lens that is adjacent the VCSEL array, and using the field lens to converge the beams to a single pupil;

receiving the converged beams from the field lens, at an objective lens that is positioned adjacent the field lens at the single pupil, and using the objective lens to diverge the beams to produce a projected light pattern;

illuminating a capture area with structured light that is created at least in part based on the projected light pattern produced using the objective lens; and

capturing an image of the structured light as reflected from one or more objects within the capture area.

10. The method of claim 9, wherein:

the projected light pattern, produced using the objective lens, includes a number of features; and

further comprising using an optical element, which is positioned optically downstream from the field lens and the objective lens, to cause a total number of features included in the structured light to be greater than the number of features included in the projected light pattern produced using the objective lens.

11. The method of claim 10, wherein the optical element that is optically downstream from the field lens and the objective lens comprises a beam splitter, and the using the optical element comprises using the beam splitter to cause the total number of features included in the structured light to be twice the number of features included in the projected light pattern produced using the objective lens.

12. The method of claim 10, wherein the optical element that is optically downstream from the field lens and the objective lens comprises a diffractive optical element (DOE), and the using the optical element comprising using the DOE to cause the total number of features included in the structured light to be an integer multiple of the number of features included in the projected light pattern produced using the objective lens.

13. The method of claim 12, wherein the using the DOE causes the total number of features included in the structured light to be twice or thrice the number of features included in the light pattern projected using the projection optics.

14. The method of claim 9, further comprising producing a depth image in dependence on the captured image.

15. The method of claim 14, further comprising updating an application based on the depth image.

16. The method of claim 9, wherein the VCSEL array comprises an X-by-Y two dimensional array of VCSELs on a single semiconductor substrate.