DEVICE FOR OPTICAL PROFILOMETRY WITH CONICAL LIGHT BEAMS

• US 20160178356A1
• Filed: 12/18/2015
• Published: 06/23/2016
• Est. Priority Date: 12/19/2014
• Status: Active Grant

• Current Assignee: Institut national d'optique
• Original Assignee: Institut national d'optique
• Inventors: LEFEBVRE, Daniel, SAMSON, ric, ROY, Sbastien, DOUCET, Michel
• Granted Patent: US 9,696,143 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01B 11/12 internal diameters
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures

Abstract

There is described an optical system for sensing the surface of an object. The system comprises: a light source for emitting at least one light beam centered on the optical axis of the system; a light reflector for reflecting the at least one incident light beam to generate at least two hollow conical light beams centered on the optical axis and having different opening angles, the at least two reflected hollow conical light beams for illuminating the surface; and an image capture device for imaging the illuminated surface.

Claims

1. A system for sensing a surface of an object, comprising:

a light source for emitting at least one incident light beam centered on an optical axis of the system;

a light reflector for reflecting the at least one incident light beam to generate at least two reflected hollow conical light beams centered on the optical axis and having different opening angles, the at least two hollow conical light beams for illuminating the surface; and

an image capture device for imaging the illuminated surface.

2. The system of claim 1, wherein the at least one incident light beam comprises at least two incident hollow conical light beams.

3. The system of claim 2, wherein the light source comprises at least two light emitters each for emitting a respective one of the at least two incident hollow conical light beams.

4. The system of claim 3, wherein the at least two light emitters are aligned and spaced apart one another along the optical axis of the system.

5. The system of claim 3, wherein the at least two light emitters are adapted to emit light at different wavelengths.

6. The system of claim 2, wherein the light source comprises a laser and a diffractive optical element for generating at least two incident hollow conical light beams.

7. The system of claim 2, wherein the light source comprises a light emitter that emits incoherent light and an opaque mask containing at least two annular apertures for generating the at least two incident hollow conical light beams.

8. The system of claim 2, wherein the light reflector comprises a mirror having a reflecting face, the reflecting face for reflecting the at least two incident hollow conical light beams and thereby generating the at least two reflected hollow conical light beams.

9. The system of claim 8, wherein the mirror has one of a conical shape, a hemi-spherical shape, and a hemi-ellipsoidal shape.

10. The system of claim 8, wherein the mirror is made of optical glass coated with a reflecting material.

11. The system of claim 1, wherein the at least one incident light beam comprises a solid conical light beam.

12. The system of claim 11, wherein the light source comprises a laser and a pinhole for generating the solid conical light beam.

13. The system of claim 11, wherein the light reflector comprises a mirror having a lateral face, the lateral face being provided with at least two annular reflecting surfaces each for reflecting a respective portion of the solid conical light beam and thereby generating the at least two reflected hollow conical light beams.

14. The system of claim 13, wherein the mirror has one of a conical shape, a hemi-spherical shape, and a hemi-ellipsoidal shape.

15. The system of claim 1, wherein the image capture device comprises a complementary metal-oxide-semiconductor (CMOS) image sensor and a fish-eye lens.

16. The system of claim 1, further comprising an optical band-pass filter located in front of the image capture device for filtering ambient light.

17. The system of claim 1, further comprising a computing module connected to the image capture device, the computing module comprising a processing unit and a memory coupled to the processing unit, and the memory comprising statements and instructions stored thereon that, when executed by the processing unit, perform a determination of a distance between the optical axis and the illuminated surface, the distance being determined using a triangulation method.

18. The system of claim 1, wherein the light source is located between the image capture device and the light reflector along the optical axis of the system.

19. The system of claim 1, further comprising a motorized platform for moving the system.