GATED 3D CAMERA

• US 20100171813A1
• Filed: 12/31/2009
• Published: 07/08/2010
• Est. Priority Date: 01/04/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft International Holdings BV (Microsoft Corporation)
• Inventors: Sander, Avner Ishay, Pelman, Asaf, Yahav, Giora
• Granted Patent: US 8,681,321 B2
• Time in Patent Office: Days
• US Class Current: 348/46
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/894 3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
• CPC Class Codes: H04N 13/20 Image signal generators
• CPC Class Codes: H04N 13/207 using a single 2D image sensor
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A camera for determining distances to a scene, the camera comprising: a light source comprising a VCSEL controllable to illuminate the scene with a train of pulses of light having a characteristic spectrum; a photosurface; optics for imaging light reflected from the light pulses by the scene on the photosurface; and a shutter operable to gate the photosurface selectively on and off for light in the spectrum.

Claims

1. A camera for determining distances to a scene, the camera comprising:

a light source comprising at least one vertical cavity surface emitting light emitting laser (VCSEL) controllable to illuminate the scene with a train of pulses of light having a characteristic spectrum;

a photosurface;

optics for imaging light reflected from the light pulses by the scene on the photosurface; and

a shutter operable to gate the photosurface selectively on and off for light in the spectrum.

2. A camera according to claim 1 wherein the light source has a characteristic spectrum with a FWHM width equal to or greater than about 1.5 nm.

3. A camera according to claim 1 wherein the characteristic spectrum has a FWHM width equal to or greater than about 2.0 nm.

4. A camera according to claim 1 wherein the characteristic spectrum has a FWHM width equal to or greater than about 2.5 nm.

5. A camera according to claim 1 wherein the VCSEL has a lasing cavity characterized by a diameter about equal to or greater than 20 microns.

6. A camera according to claim 1 wherein the VCSEL has a lasing cavity characterized by a diameter about equal to or greater than 25 microns.

7. A camera according to claim 1 wherein a normalized convolution of shutter contrast ratio (CR) and characteristic spectrum is greater than or equal to about 10 for a temperature difference between the shutter and light source less than or equal to about 20°

C.

8. A camera according to claim 1 wherein a normalized convolution of shutter contrast ratio (CR) and characteristic spectrum is greater than or equal to about 12 for a temperature difference between the shutter and light source less than or equal to about 20°

C.

9. A camera according to claim 1 wherein the light source operates at a power level about equal to or greater than 12 Watts to illuminate the scene with the train of light pulses.

10. A camera according to claim 1 wherein the power level is about equal to or greater than 15 Watts.

11. A camera according to claim 1 wherein the power level is about equal to or greater than 18 Watts.

12. An apparatus for determining distances to a scene, the apparatus comprising:

a light source having an array of VCSELs provides improved matching of the light source to the camera shutter reduced bias errors, controllable to illuminate the scene with a train of pulses of light having a characteristic spectrum;

a photosurface;

a lens system for imaging light reflected from the light pulses by the scene on the photosurface; and

a shutter operable to gate the photosurface selectively on and off for light in the spectrum.

13. An apparatus according to claim 12 wherein the light source has a characteristic spectrum with a FWHM width equal to or greater than about 1.5 nm.

14. An apparatus according to claim 13 wherein the VCSEL has a lasing cavity characterized by a diameter about equal to or greater than 20 microns.

15. An apparatus according to claim 14 wherein a normalized convolution of shutter contrast ratio (CR) and characteristic spectrum is greater than or equal to about 10 for a temperature difference between the shutter and light source less than or equal to about 20°

C.

16. An apparatus according to claim 15 wherein the light source operates at a power level about equal to or greater than 12 Watts to illuminate the scene with the train of light pulses.

17. A camera for determining distances to a scene, the camera comprising:

a light source having an array of VCSELs providing improved matching of the light source to the camera shutter and being controllable to illuminate the scene with a train of pulses of light having a characteristic spectrum, the light source has a characteristic spectrum with a FWHM width equal to or greater than about 1.5 nm, and a lasing cavity characterized by a diameter about equal to or greater than 20 microns;

a controller coupled to the light source;

a photosurface comprising a CCD or CMOS photosensitive surface;

a lens system for imaging light reflected from the light pulses by the scene on the photosurface; and

a shutter operable to gate the photosurface selectively on and off for light in the spectrum.