Plurality of light sources for inspection apparatus and method

• US 20050200838A1
• Filed: 02/25/2005
• Published: 09/15/2005
• Est. Priority Date: 09/10/2003
• Status: Active Grant

• Current Assignee: Raven Engineering, Inc.
• Original Assignee: Shearographics, LLC
• Inventors: Shaw, Eugene L., Wright, Forrest S.
• Granted Patent: US 7,187,437 B2
• Time in Patent Office: Days
• US Class Current: 356/237.100
• CPC Class Codes: G01B 11/162 by speckle- or shearing interferometry
• CPC Class Codes: G01M 17/027 using light, e.g. infrared, ultraviolet or holographic techniques
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features

Abstract

Described is an anomaly detector apparatus 10 for detecting an anomaly in a substrate, e.g., a tire comprising: a source of coherent light 20 to shine the light 27 directly onto the tire surface 24 and the light being reflected 32 from the tire; a stressing apparatus 12, which is juxtaposed to the tire and which, can optionally stress the tire; a reflected light receiving apparatus 40 for receiving the light 32 reflected directly from the tire surface 24 whether the tire is in a stressed or unstressed condition; a comparator 44 which views and compares images of reflected light from the reflected light receiving apparatus 40 when the tire is stressed or unstressed thereby ascertaining an anomaly in the tire and generates an output from the comparison; and a display apparatus 46 electronically connected to the comparator for displaying the output from the comparator. Also described is a plurality of sources 100 and light receiving apparatus 102 sitting atop a vertically moving support structure 110 that may view 360 degrees, of the whole circumferential interior surface of the tire.

Claims

1. An anomaly detector apparatus for detecting an anomaly in a substrate comprising:

a plurality of sources of coherent light to shine the light directly onto the substrate surface and the light being reflected from the substrate;

a stressing apparatus, which is juxtaposed to the substrate and which, can optionally, stress the substrate;

a plurality of reflected light receiving apparatus for receiving the light reflected directly from the substrate whether the substrate is in a stressed or unstressed condition, wherein the sources of light are spaced to shine simultaneously on the entirety of the substrate surface to be tested and all of the receiving apparatus are spaced to receive the reflected light simultaneously to detect an anomaly on all substrate surfaces on which the light is shown;

a comparator which views and compares images of reflected light from the reflected light receiving apparatus when the substrate is stressed or unstressed thereby ascertaining an anomaly in the substrate and which generates an output from the comparison; and

a display apparatus electronically connected to the comparator for displaying the output from the comparator.

2. The apparatus of claim 1 wherein there are a plurality of clusters of light sources and light receiving apparatus wherein each cluster has a plurality of light sources that are in a plane and the light sources are spaced near each light receiving apparatus and which plane forms an angle from 10 to 45 degrees with an axis of the light receiving apparatus.

3. The apparatus of claim 1 for detecting an anomaly in a tire.

4. The apparatus of claim 2 wherein there are about 2 to 8 clusters to view the substrate.

5. The apparatus of claim 2 wherein there are 2 to 6 sources of light per light receiving apparatus with one half of the sources spaced 180 degrees from each other spaced about the circumference of the light receiving apparatus.

6. The apparatus of claim 1 where the source of light is a laser.

7. The apparatus of claim 1 further comprising a light shaping elliptical diffuser placed between the source of light and the tire to distribute the light over a portion of the tire surface.

8. The apparatus of claim 3 further comprising a light shaping elliptical diffuser placed between the source of light and the tire to distribute the light over a portion of the tire without breaking the source of light into more than one beam.

9. The apparatus of claim 1 wherein the reflected light receiving apparatus is a camera.

10. The apparatus of claim 5 wherein the camera is electronically connected to a computer.

11. The apparatus of claim 1 wherein the comparator is software operating in a computer which displays the output.

17. The method of claim 11 where the source of light is a laser.

22. The method of claim 11 wherein the comparator is software operating in a computer which displays the output.

12. A method of detecting an anomaly in a substrate comprising:

providing a plurality of sources of coherent light;

shining the light directly onto the substrate surface, thereby generating a reflected light from the substrate;

stressing the substrate;

providing a plurality of reflected light receiving apparatus for receiving the light reflected directly from the substrate whether the substrate is in a stressed or unstressed condition, wherein the sources of light are spaced to shine substantially simultaneously on the entirety of the substrate surface to be tested and all of the receiving apparatus are spaced to receive the reflected light substantially simultaneously to detect an anomaly on all substrate surfaces on which the light is shown;

providing a comparator which views and compares images of reflected light from the reflected light receiving apparatus when the substrate is stressed or unstressed thereby ascertaining an anomaly in the substrate and generates an output from the comparison; and

displaying, from apparatus electronically connected to the comparator, the output from the comparator.

13. The method of claim 12 wherein there are a plurality of clusters of light sources and light receiving apparatus wherein each cluster has a plurality of light sources that are in a plane and the light sources are spaced near each light receiving apparatus and which plane forms an angle from 10 to 45 degrees with an axis of the light receiving apparatus.

14. The method of claim 12 wherein the substrate to be tested is a tire.

15. The method of claim 13 wherein there are about 2 to 8 clusters to view the interior of a tire.

16. The method of claim 12 wherein there are 2 to 6 sources of light per light receiving apparatus with one half of the sources spaced 180 degrees from each other spaced about the circumference of the light receiving apparatus.

18. The method of claim 12 further comprising distributing the light over a portion of the substrate surface by a light shaping elliptical diffuser placed between the source of light and the tire.

19. The method of claim 13 further comprising distributing the light over a portion of the tire without breaking the source of light into more than one beam by a light shaping elliptical diffuser placed between the source of light and the tire.

20. The method of claim 12 wherein the reflected light receiving apparatus is a camera.

21. The method of claim 12 further comprising passing the images from the camera to a computer.

23. The method of claim 13 wherein the output is scaled to size the anomaly in the tire.

24. The method of claim 12 where the output is characterized as a scattered speckle reflection.

25. The method of claim 12 wherein the output is black on white or white on black.

26. The method of claim 12 wherein the output is in multiple colors to enhance visibility of the anomaly.