3D-CAMERA AND METHOD FOR THE THREE-DIMENSIONAL MONITORING OF A MONITORING AREA

• US 20120293625A1
• Filed: 05/03/2012
• Published: 11/22/2012
• Est. Priority Date: 05/18/2011
• Status: Active Grant

• Current Assignee: Sick AG (Sick)
• Original Assignee: Sick AG (Sick)
• Inventors: SCHMITZ, Stephan, SCHNEIDER, Florian
• Granted Patent: US 9,228,697 B2
• Time in Patent Office: Days
• US Class Current: 348/46
• CPC Class Codes: F16P 3/142 using image capturing devices
• 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: G06T 2207/10012 Stereo images
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/18394 Apertures, e.g. defined by the shape of the upper electrode
• CPC Class Codes: H01S 5/423 having a vertical cavity
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects

Abstract

A 3D-camera (10) is provided, having at least one image sensor (14a-b) and at least one illumination unit (100) which comprises a light source and which is configured for generating an irregular illumination pattern (20) in an illumination area (12) of the 3D-camera (10). The light source comprises a semiconductor array (104) having a plurality of individual emitter elements (106) in an irregular arrangement, and a respective individual emitter element (106) generates a pattern element (112) of the irregular illumination pattern (20).

Claims

1. A 3D-camera (10) having at least one image sensor (14a-b) and at least one illumination unit (100) which comprises a light source and which is configured for generating an irregular illumination pattern (20) in an illumination area (12) of the 3D-camera (10), wherein the light source comprises a semiconductor array (104) having a plurality of individual emitter elements (106) in an irregular arrangement, and wherein a respective individual emitter element (106) generates a pattern element (112) of the irregular illumination pattern (20).

2. The 3D-camera (10) according to claim 1,

wherein the semiconductor array (104) is a VCSEL array.

3. The 3D-camera (10) according to claim 1,

wherein the semiconductor array (104) comprises a large number of at least a thousand, ten thousand, or a hundred thousand individual emitter elements (106).

4. The 3D-camera (10) according to claim 1,

wherein each individual emitter element (106) comprises a point-like emitter surface, and wherein the pattern element (112) generated by the individual emitter element (106) comprises the shape of the emitter surface.

5. The 3D-camera (10) according to claim 4,

wherein the point-like emitter surfaces have at least one of mutually different shapes and sizes.

6. The 3D-camera (10) according to claim 1,

wherein the individual emitter elements (106) form at least two groups (106a-b), and wherein a group (106a-b) of individual emitter elements (106) can be activated without activating the remaining groups (106a-b) of individual emitter elements (106).

7. The 3D-camera (10) according to claim 1,

wherein the individual emitter elements (106) are controllable with mutually different currents.

8. The 3D-camera (10) according to claim 7,

wherein the individual emitter elements (106) in an outer region of the semiconductor array (104) are controllable with higher currents than individual emitter elements (106) in an inner region of the semiconductor array (104).

9. The 3D-camera (10) according to claim 1,

wherein the density of the individual emitter elements (106) on the semiconductor array (104) varies.

10. The 3D-camera (10) according to claim 9,

wherein more individual emitter elements (106) are provided in an outer region of the semiconductor array (104) than in an inner region of the semiconductor array (104).

11. The 3D-camera (10) according to claim 1,

wherein the arrangement of the pattern elements (112) in the illumination pattern (20) corresponds to the arrangement of the individual emitter elements (106) on the semiconductor array (104).

12. The 3D-camera (10) according to claim 1,

wherein the illumination unit (100) comprises an imaging objective (108, 114) to image the illumination pattern (20) from the near field at the semiconductor array (104) into the monitoring area (12).

13. The 3D-camera (10) according to claim 12,

wherein imaging objective (108, 114) and semiconductor array (104) are arranged mutually movable to image different subsets of individual emitter elements (106).

14. The 3D-camera (10) according to claim 1,

wherein a microlens array is arranged in front of the semiconductor array (104).

15. The 3D-camera (10) according to claim 14,

wherein the microlenses have the same irregular arrangement on the microlens array as the individual emitter elements (106) on the semiconductor array (104).

16. The 3D-camera (10) according to claim 1,

which is made as a stereo camera and comprises an evaluation unit (22) configured for the application of a stereo algorithm which, for generating a three-dimensional distance image, detects partial regions corresponding to one another in the two images of the monitoring area (12) illuminated by the illumination pattern (20) and captured by the two cameras (14a-b, 16a-b) of the stereo camera, and calculates the distances from their disparity.

17. The 3D-camera (10) according to claim 1,

which is made as a safety camera, wherein the evaluation unit (22) is configured to detect forbidden intrusions into the monitoring area (12) and to thereupon generate a shutdown signal, and wherein a safety output (26) is provided to output a shutdown signal to a monitored machine.

18. A method for the three-dimensional monitoring of a monitoring area (12),

wherein an illumination unit (100) generates an irregular illumination pattern (20) in the monitoring area (12), wherein a 3D-camera (10) captures images of the illuminated monitoring area (12), wherein a plurality of individual light beams (110) is transmitted by a corresponding plurality of individual emitter elements (106) on a semiconductor array (104), wherein the individual emitter elements (106) are arranged irregularly on the semiconductor array (104) and the bundle of individual light beams (110) leads to the irregular illumination pattern (20) due to the irregular arrangement, wherein a respective individual emitter element (106) generates a point-like pattern element (112) of the illumination pattern (20) via its individual light beam (110).