LASER DEVICE FOR PROJECTING A STRUCTURED LIGHT PATTERN ONTO A SCENE

• US 20150316368A1
• Filed: 11/22/2013
• Published: 11/05/2015
• Est. Priority Date: 11/29/2012
• Status: Active Grant

• Current Assignee: TRUMPF Photonic Components GmbH (TRUMPF SE + Co. KG)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: MOENCH, HOLGER, GRONENBORN, STEPHAN, CARPAIJ, MARK
• Granted Patent: US 10,386,178 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01B 11/2513 with several lines being projected in more than one direction, e.g. grids, patterns
• CPC Class Codes: G01B 11/254 Projection of a pattern, viewing through a pattern, e.g. moiré
• CPC Class Codes: G01S 17/46 Indirect determination of position data
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/4815 using multiple transmitters
• 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 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 5/265 Mixing

Abstract

The present invention relates to a laser device (10) for projecting a structured light pattern (9) onto a scene (15). The device is formed of several arrays (1) of semiconductor lasers (2), each array (1) comprising an irregular distribution of emission areas (2a) of the semiconductor lasers (2). One or several imaging optics (4) image said arrays (1) to an imaging space and superpose the images of said arrays (1) in the imaging space to form said light pattern (9). The proposed laser device generates a light pattern with high contrast and efficiency which may be used for 3D imaging systems, e. g. in automotive applications.

Claims

1. A laser device for projecting a structured light pattern onto a scene, said device comprising:

a plurality of arrays of semiconductor lasers, each of the arrays comprising an irregular distribution of emission areas of the semiconductor lasers, and

at least one imaging optics for generating images from said arrays to an imaging space and superposing the images from said arrays in the imaging space to form a light pattern such that a failure pattern of a single array showing a clustering of defective mesas does not lead to dead areas in the light pattern.

2. The device according to claim 1, wherein said imaging optics is configured such that most of the beam spots in said light pattern comprise at least one neighbouring beam spot which originates from the semiconductor laser of a different array.

3. The device according to claim 1, wherein said semiconductor lasers are VCSELs.

4. The device according to claim 3, wherein the VCSELs of at least one of said arrays comprise emission areas with at least two different shapes.

5. The device according to claim 3, wherein the VCSELs of each array comprise emission areas of identical shape, shapes of the emission areas of at least two arrays being different from one another.

6. The device according to claim 3, wherein diameters of emission areas of the VCSELs in at least one direction in each array are ≦

10 μ

m, a minimum distance between said emission areas being ≧

20 μ

m.

7. The device according to claim 1, wherein said imaging optics is configured such that the superposed images from said arrays are slightly shifted with respect to one another in at least a first direction in the imaging space.

8. The device according to claim 7, wherein said imaging optics is configured to squeeze the superposed images from said arrays in a second direction perpendicular to said first direction in the imaging space, said squeezing being selected to achieve a substantially equal density of beam spots in both directions.

9. The device according to claim 1, further comprising a control unit for sequential switching of the different arrays.

10. The device according to claim 1, further comprising a camera arranged to take an image of a scene in the image space onto which the light pattern is projected.

11. The device according to claim 1, wherein the device is used for a 3D recognition or 3D detection of scenes.

12. The device according to claim 1, wherein the device is used for detection of objects in a car environment.

13. The device according to claim 1, wherein the device is used for the 3D recognition of scenes in industrial production or logistic areas.

14. The device according to claim 1, wherein the device is used in user interfaces.