Three-dimensional scanner having pixel memory

• US 10,458,783 B2
• Filed: 10/05/2018
• Issued: 10/29/2019
• Est. Priority Date: 10/13/2017
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Technologies Incorporated
• Inventors: Wolke, Matthias, Heidemann, Rolf, Hillebrand, Gerrit, Doring, Daniel
• Primary Examiner(s): Rahman, Md M
• Application Number:
  US16/152,789
• Publication Number:
  US 20190113334A1
• Time in Patent Office: 389 Days
• Field of Search: 356603
• 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: G01B 11/2545 with one projection direction and several detection directions, e.g. stereo
• 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 23/90 Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums

Abstract

A triangulation scanner includes a projector, a camera, and a processor, the projector projecting a first pattern of light on a first point during first intervals and a no light during second intervals, the camera including an optical detector, a first accumulator, and a second accumulator, the optical detector receiving reflected light from the first point, the first and second accumulators summing signals from the optical detector during the first and second intervals, respectively, the processor determining 3D coordinates of the first point based at least in part on the first pattern, the summed signals from the first and second accumulators, and a speed of light in air.

Claims

1. A triangulation scanner system comprising:

a projector operable to project onto an object a first pattern of light at a first light level during first time intervals and to project onto the object the first pattern of light at a second light level during second time intervals, the second light level being different than the first light level;

a first camera including a first lens and a first integrated circuit having a first photosensitive array, the first photosensitive array having a plurality of pixels including a first pixel, the first pixel including an optical detector, a first memory, and a second memory, the optical detector operable to produce signals in response to light levels reflected from a first point on the object, the first memory operable to store signals received from the optical detector during the first time intervals to obtain a first stored signal, the second memory operable to store signals received from the optical detector during the second time intervals to obtain a second stored signal; and

a processor operable to execute computer instructions that, when executed on the processor, determine three-dimensional (3D) coordinates of the first point based at least in part on the projected first pattern of light, the first stored signal, and the second stored signal.

2. The triangulation scanner system of claim 1 wherein the processor is further operable to execute computer instructions that, when executed on the processor, determine the 3D coordinates of the first point further based on a relative pose of the projector and the first camera.

3. The triangulation scanner system of claim 1 wherein the first time interval has a corresponding second time interval of equal duration.

4. The triangulation scanner system of claim 1 further comprising an analog-to-digital converter operable to convert analog signals to digital signals, the analog-to-digital converter being at a location selected from the group consisting of:

within the first pixel, outside the first pixel but within the first integrated circuit, and outside the first integrated circuit.

5. The triangulation scanner system of claim 1 further comprising:

a second camera including a second lens and a second integrated circuit having a second photosensitive array, the second camera operable to capture a second image of the object on the second photosensitive array.

6. The triangulation scanner of claim 5 wherein the processor is further operable to execute computer instructions that, when executed on the processor, determine the 3D coordinates of the first point further based on a relative pose of the first camera and the second camera.

11. The method of claim 7 triangulation scanner system of claim 1 further comprising:

providing a second camera including a second lens and a second integrated circuit having a second photosensitive array; and

with the second camera, capturing a second image of the object on the second photosensitive array.

12. The method of claim 11 further comprising:

with the processor, executing computer instructions to determine the 3D coordinates of the first point further based on a relative pose of the first camera and the second camera.

7. A method comprising:

providing a projector, a first camera, and a processor, the first camera including a first lens and a first integrated circuit having a first photosensitive array, the first photosensitive array having a plurality of pixels including a first pixel, the first pixel including an optical detector, a first memory, and a second memory;

with the projector, projecting onto an object a first pattern of light at a first light level during a first time interval;

with the projector, projecting onto the object the first pattern of light at a second light level during a second time interval, the second light level being different than the first light level;

with the optical detector, producing signals in response to light levels reflected from a first point on the object;

with the first memory, storing a signal received from the optical detector during the first time interval to obtain a first stored signal;

with the second memory, storing a signal received from the optical detector during the second time interval to obtain a second stored signal;

with the processor, executing computer instructions to determine three-dimensional (3D) coordinates of the first point based at least in part on the projected first pattern of light, the first stored signal, and the second stored signal; and

storing the 3D coordinates of the first point.

8. The method of claim 7 further comprising:

with the processor, executing computer instructions to determine the 3D coordinates of the first point further based on a relative pose of the projector and the first camera.

9. The method of claim 7 wherein the first time interval has a corresponding second time interval of equal duration.

10. The method of claim 7 further comprising:

providing an analog-to-digital converter, the analog-to-digital converter being at a location selected from the group consisting of;

within the first pixel, outside the first pixel but within the first integrated circuit, and outside the first integrated circuit; and

with the analog-to-digital converter, converting analog signals to digital signals.

13. A triangulation scanner system comprising:

a projector operable to project onto an object a first pattern of light;

a first camera including a first lens and a first integrated circuit having a first photosensitive array, the first photosensitive array having a plurality of pixels including a first pixel, the first pixel including an optical detector, a first memory, and a second memory, the optical detector operable to produce signals in response to light levels reflected from a first point on the object, the first memory operable to store a signal received from the optical detector during a first time interval to obtain a first stored signal, the second memory operable to store a signal received from the optical detector during a second time interval to obtain a second stored signal, the second time interval being different than the first time interval; and

a processor operable to execute computer instructions that, when executed on the processor, determine three-dimensional (3D) coordinates of the first point based at least in part on the projected first pattern of light, the first stored signal, and the second stored signal.

14. The triangulation scanner system of claim 13 wherein the processor is further operable to execute computer instructions that, when executed on the processor, determine the 3D coordinates of the first point further based on a relative pose of the projector and the first camera.

15. The triangulation scanner system of claim 13 wherein the first time interval has a corresponding second time interval of equal duration.

16. The triangulation scanner system of claim 13 further comprising an analog-to-digital converter operable to convert analog signals to digital signals, the analog-to-digital converter being at a location selected from the group consisting of:

within the first pixel, outside the first pixel but within the first integrated circuit, and outside the first integrated circuit.

17. A method comprising:

providing a projector, a first camera, and a processor, the first camera including a first lens and a first integrated circuit having a first photosensitive array, the first photosensitive array having a plurality of pixels including a first pixel, the first pixel including an optical detector, a first memory, and a second memory;

with the projector, projecting onto an object a first pattern of light;

with the optical detector, producing signals in response to light levels reflected from a first point on the object;

with the first memory, storing a signal received from the optical detector during the first time interval to obtain a first stored signal;

with the second memory, storing a signal received from the optical detector during the second time interval to obtain a second stored signal, the second time interval being different than the first time interval;

with the processor, executing computer instructions to determine three-dimensional (3D) coordinates of the first point based at least in part on the projected first pattern of light and on the first stored signal and the second stored signal; and

storing the 3D coordinates of the first point.

18. The method of claim 17 further comprising:

with the processor, executing computer instructions to determine the 3D coordinates of the first point further based on a relative pose of the projector and the first camera.

19. The method of claim 17 further comprising:

providing a second camera including a second lens and a second integrated circuit having a second photosensitive array; and

with the second camera, capturing a second image of the object on the second photosensitive array.

20. The method of claim 19 further comprising:

with the processor, executing computer instructions to determine the 3D coordinates of the first point further based on a relative pose of the first camera and the second camera.