Optical scanning probe

• US 8,117,668 B2
• Filed: 04/26/2007
• Issued: 02/14/2012
• Est. Priority Date: 04/27/2006
• Status: Active Grant

• Current Assignee: 3D Scanners Ltd. (Nikon Corporation)
• Original Assignee: 3D Scanners Ltd. (Nikon Corporation)
• Inventors: Crampton, Stephen James, Champ, Peter
• Primary Examiner(s): NGUYEN, KIET TUAN
• Application Number:
  US12/298,688
• Publication Number:
  US 20090205088A1
• Time in Patent Office: 1,755 Days
• Field of Search: 850/9
• US Class Current: 850/9
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object

Abstract

The present invention relates to a scanning probe (2) for capturing data from a plurality of points on the surface of an object by irradiating the object with a light stripe and detecting light reflected from the object surface, the scanning probe comprising (a) stripe generating means (14) for generating and emitting a light stripe (55); (b) a camera (16) comprising an imaging sensor having an array of pixels to detect the light stripe reflected from the object surface: (c) means for adjusting the intensity of the light stripe (55) during acquisition of the frame, in dependence upon the intensities detected by the camera (16). It also relates to a means to modify the stripe length, a scanner with separate compartment for the processing means, and an attachable dust cover for a scanner.

Claims

1. A scanning probe for capturing data from a plurality of points on the surface of an object by irradiating the object with a light stripe and detecting light reflected from the object surface, the scanning probe comprising:

(a) stripe generator for generating and emitting the light stripe;

(b) a camera comprising an imaging sensor having an array of pixels to detect the light stripe reflected from the object surface;

(c) intensity adjuster stripe during acquisition of a single frame, in dependence upon intensities detected by the camera;

wherein the camera and/or the stripe generator are configured such that different subsets of the array of pixels at different times detect light reflected from the light stripe during the acquisition of the frame, the different subsets of the array of pixels corresponding to different positions on the detected light stripe reflected from the object surface,

and wherein the intensity adjuster stripe is configured to adjust the intensity subsequent to and in dependence upon the detection of the intensities by the subset of pixels, which adjustment takes place during acquisition of the frame.

2. The scanning probe according to claim 1, wherein the imaging sensor is a CMOS equipped with a rolling shutter, wherein the rolling shutter is configured such that the different subsets of the array of pixels at different times detect light reflected from the light stripe during the acquisition of the frame, the different subsets of the array of pixels corresponding to different positions on the detected light stripe, and

wherein the stripe generator is configured to generate a stripe having an invariable intensity across the length of the stripe which has an overall intensity that is adjustable during acquisition of the frame, in dependence upon the intensities detected by the subset of pixels.

3. The scanning probe according to claim 1, wherein the stripe generator comprises static optics.

4. The scanning probe according to claim 1, wherein the stripe generator comprises a laser and solid cylindrical optics.

5. The scanning probe according to claim 1, wherein the stripe generator comprises a laser and a micro-mirror array.

6. The scanning probe according to claim 1, wherein the intensity adjustor stripe is arranged to set the intensity measured by each subset of the array of pixels in dependence upon the light detected by the pixel(s) in the corresponding subset for at least one previously projected light stripe, and the intensity of the light stripe emitted for the corresponding subset in at least one previously projected light stripe.

7. The scanning probe according to claim 1, wherein the stripe generator is configured to generate a stripe comprising a plurality of spots whose individual intensities are adjustable during acquisition of the frame, and wherein the spots are separately projected so that different subsets of the array of pixels at different times detect light reflected from the light stripe during the acquisition of the frame, the different subsets corresponding to different positions on the detected light stripe, and wherein the individual spot intensities are adjusted in dependence upon the intensities detected by the subset of the array of pixels.

8. The scanning probe according to claim 7, wherein the stripe generator comprises a laser and a micro-mirror array.

9. The scanning probe according to claim 7, wherein the stripe generator comprises moving optics.

10. The scanning probe according to claim 9, wherein the stripe generator comprises a laser and a moving mirror.

11. The scanning probe according to claim 7, whereby the imaging sensor is a CMOS equipped with a rolling shutter, or a CCD.

12. The scanning probe according to claim 7, wherein the intensity adjuster is arranged to set the intensity of the spots within a projected stripe for each subset of pixels in dependence upon the light detected by the pixel(s) in each subset for at least one previously projected spot in the stripe, and the intensity of the emitted light stripe corresponding to each subset in at least one previously projected spot in the stripe.

13. The scanning probe according to claim 1, further comprising an exposure time adjuster for adjusting the exposure time for at least one subset of the array of pixels in dependence upon the light intensity set for the subset.

14. A method of capturing data from a plurality of points on the surface of an object by irradiating the object with a light stripe and detecting light reflected from the object surface, the method comprising:

(a) generating and emitting the light stripe using a stripe generator;

(b) detecting the light stripe reflected from the object surface using an imaging sensor comprising an array of pixels,

(c) adjusting the intensity of the light stripe during acquisition of a single frame in dependence upon the intensity of light detected by the pixels,

different subsets of the array of pixels at different times detect light reflected from the light stripe during the acquisition of the frame, the different subsets of the array of pixels corresponding to different positions on the detected light stripe, to determine the light detected by the pixel(s) in each subset, and wherein the intensity of the light stripe is adjusted subsequent to and in dependence upon the detection of intensity by the subset of the array of pixels, which adjustments take place during acquisition of the frame.

15. The method according to claim 14, wherein the light stripe is detected using a CMOS imaging sensor equipped with a rolling shutter allowing different subsets of the sensor pixels at different times to detect light reflected from the light stripe during the acquisition of the frame, the different subsets of the array of pixels corresponding to different positions on the detected light stripe, and wherein the stripe generator generates a stripe having an invariable intensity across the length of the stripe which has an overall intensity that is adjusted during acquisition of a single frame.

16. The method according to claim 15, wherein the stripe generator comprises static optics.

17. The method according to claim 15, wherein the stripe generator comprises a laser and solid cylindrical optics.

18. The method according to claim 15, wherein the stripe generator comprises a laser and a micro-mirror array.

19. The method according to claim 15, wherein the intensity of the light is further adjusted by setting the intensity for each subset of the array of pixels in dependence upon the light detected by the pixel(s) in the corresponding subset for at least one previously projected light stripe, and the intensity of the light stripe emitted for the corresponding subset in at least one previously projected light stripe.

20. The method according to claim 14, wherein the stripe generator generates a stripe comprising a plurality of spots whose individual intensities are adjustable during acquisition of the single frame, and wherein the spots are separately projected so that different subsets of the sensor pixels at different times detect light reflected from the stripe during the acquisition of the frame, the different subsets corresponding to different positions on the detected light stripe, wherein the individual spot intensities are adjusted in dependence upon the intensities detected by the subset of the array of pixels.

21. The method according to claim 20, wherein the stripe generator comprises a laser and a micro-mirror array.

22. The method according to claim 20, wherein the stripe generator comprises moving optics.

23. The method according to claim 22, wherein the stripe generator comprises a laser and a moving mirror.

24. The method according to claim 20, wherein the imaging sensor is a CMOS camera equipped with a rolling shutter, or a CCD.

25. The method according to claim 20, wherein the intensity of the light stripe is further adjusted by setting the intensity within a projected stripe for each subset of pixels in dependence upon the light detected by the pixel(s) in the corresponding subset for at least one previously projected spot in the stripe, and the power of the light emitted for that subset in at least one previously projected spot in the stripe.

26. The method according to claim 25, further comprising adjusting the exposure time for at least one subset of the array of pixels in dependence upon the light power set for the subset.