ILLUMINATION MODULES THAT EMIT STRUCTURED LIGHT

• US 20150097947A1
• Filed: 10/09/2013
• Published: 04/09/2015
• Est. Priority Date: 10/09/2013
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Hudman, Joshua, Masalkar, Prafulla
• Granted Patent: US 9,443,310 B2
• Time in Patent Office: Days
• US Class Current: 348/136
• 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 that outputs structured light that illuminates a capture area; and

an image detector module that captures 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 emits a separate beam of light, and wherein the plurality of VCSELs collectively emits a light pattern; and

projection optics that receives 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 light pattern projected by the projection optics.

2. The depth camera system of claim 1, wherein the projection optics include:

a field lens that receives the beams of light emitted by the VCSELs of the VCSEL array and converges the beams; and

an objective lens that receives the converged beams from the field lens and diverges the beams to produce the light pattern projected by the projection optics.

3. 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, optically downstream from the projection optics, that causes 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.

4. The depth camera system of claim 3, wherein the optical element comprises a beam splitter that causes 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.

5. The depth camera system of claim 3, wherein the optical element comprise a diffractive optical element (DOE) that causes 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.

6. The depth camera system of claim 5, wherein the diffractive optical element (DOE) causes 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.

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

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

8. The depth camera system of claim 7, wherein the one or more processors also update an application based on the depth image.

9. A depth camera system, comprising:

an illumination module that outputs structured light that illuminates a capture area; and

an image detector module that captures 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) having a first pitch;

a micro-lens array (MLA) comprising a plurality of lenslets having a second pitch that is offset relative to the first pitch of VCSEL array, which causes light beams received by the MLA, from the VCSEL array, to converge; and

a diffractive optical element (DOE) that receives converged light beams from the MLA and outputs the structured light that illuminates the capture area.

10. The depth camera system of claim 9, wherein the second pitch is less than the first pitch.

11. The depth camera system of claim 9, wherein the MLA causes light beams, received by the MLA from the VCSEL array, to converge to a single pupil at which is located the DOE.

12. The depth camera system of claim 9, wherein:

a light pattern output by the MLA includes a number of features; and

the DOE causes a 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 output by the MLA.

13. The depth camera system of claim 12, wherein the DOE causes 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 output by the MLA.

14. The depth camera system of claim 9, wherein:

the VCSEL array is formed on a semiconductor substrate that includes first alignment elements; and

the MLA includes second alignment elements that align with the first alignment elements.

15. The depth camera system of claim 9, further comprising:

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

16. A depth camera system, comprising:

an illumination module that outputs structured light that illuminates a capture area; and

an image detector module that captures 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 emits a separate beam of light;

a first diffractive optical element (DOE) that collimates each beam of light output by each of the plurality of VCSELs of the VCSEL array; and

a second DOE that receives the collimated beams produced by the first DOE and outputs the structured light.

17. The depth camera system of claim 16, wherein:

a light pattern output by the first DOE includes a number of features; and

the second DOE causes a 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 output by the first DOE.

18. The depth camera system of claim 17, wherein the second DOE causes 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 output by the first DOE.

19. The depth camera system of claim 16, further comprising:

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

20. The depth camera system of claim 19, wherein the one or more processors also update an application based on the depth image.