Web inspection system for analysis of moving webs

• US 6,259,109 B1
• Filed: 08/21/1998
• Issued: 07/10/2001
• Est. Priority Date: 08/27/1997
• Status: Expired due to Fees

• Current Assignee: Datacube, Inc.
• Original Assignee: Datacube, Inc.
• Inventors: Wilson, Anthony W., Simmons, David M., Dalmia, Arun, OʼNeill, Conor
• Primary Examiner(s): Lee, John R.
• Assistant Examiner(s): PYO, KEVIN K
• Application Number:
  US09/137,789
• Time in Patent Office: 1,054 Days
• Field of Search: 250/559.07, 250/559.08, 250/559.44, 250/559.45, 250/559.46, 356/429, 356/430, 356/237.1, 356/239.3, 348/125, 348/128, 348/88, 382/108
• US Class Current: 250/559.08
• CPC Class Codes: G01N 21/8903 using a multiple detector array
• CPC Class Codes: G06T 2207/30124 Fabrics; Textile; Paper
• CPC Class Codes: G06T 7/0004 Industrial image inspection

Abstract

A web inspection system for analysis of a moving web of material records and stores continuous sequences of the web. The web inspection system includes a camera for recording the continuous sequence of the web, an encoder for synchronizing movements of the web with the video image being recorded, and an Image Processing System (IPS) including a real time video disk for storing the image of the web and for displaying the continuous sequence web image on a video display. The IPS is also utilized for detecting faults or features and for categorizing the faults or features detected. The entire web is recorded and the image can be viewed either interactively while the image is being recorded or at a later time. The recorded image of the web can be played back at a slower speed to allow for a more detailed inspection of the web. The sequence image can be analyzed to build a defect image database. The web inspection system can also be utilized for sorting and displaying defect information.

Claims

1. A web inspection system comprising:

a camera assembly disposed proximate a moving web of material, said camera assembly providing a continuous sequence of real time images of the web as the web passes by said camera assembly;

an image processing system in electrical communication with said camera assembly, the image processing system including a storage element for storage of the continuous sequence of images of the moving web of material;

a light assembly for providing illumination to said web, said light assembly comprising a light source with a light sensor and a ballast in communication with said light source, such that a constant light intensity is automatically maintained, said light assembly in electrical communication with said image processing system; and

a video display in electrical communication with said image processing system, said video display operative to display the continuous sequence of images of the web.

2. The web inspection system of claim 1 wherein said storage element comprises a disk drive.

3. The web inspection system of claim 1 wherein said storage element comprises a video disk drive.

4. The web inspection system of claim 1 further comprising an encoder disposed adjacent said web, said encoder in electrical communication with said image processing system.

5. The web inspection system of claim 1 wherein said camera assembly comprises:

an enclosure;

a camera disposed within said enclosure; and

an adjustable mount for securing said camera and said enclosure in a stable position.

6. The web inspection system of claim 5 wherein said camera assembly further comprises an encoder interface in electrical communication with said image processing system.

7. The web inspection system of claim 5 wherein said camera assembly further comprises a light control interface in electrical communication with said image processing system.

8. The web inspection system of claim 5 wherein said camera is selected from the group consisting of a linear array camera, an area camera and a TDI camera.

9. The web inspection system of claim 1, wherein said light assembly comprises:

an enclosure;

disposed about said light source

a mounting bracket for securing said enclosure and said light source in a stable position.

10. The web inspection system of claim 1 wherein said light source is selected from the group consisting of a metal halide light and a fiber optic light.

11. The web inspection system of claim 1 wherein said camera assembly is disposed generally perpendicular to said web.

12. The web inspection system of claim 1 wherein said camera assembly is disposed obliquely with respect to said web.

13. The web inspection system of claim 9 wherein said light source is disposed subjacent with respect to said web.

14. The web inspection system of claim 9 wherein said light source is disposed obliquely with respect to said web.

15. The web inspection system of claim 1 wherein said video display is operative to display the continuous sequence of images of the web as said camera assembly is providing the continuous sequence of images of the web.

16. The web inspection system of claim 1 wherein said video display is operative to display the continuous sequence of images of the web at a later time than a time said camera assembly is providing the continuous sequence of images of the web.

17. The web inspection system of claim 1 wherein said web inspection system is operative to display the continuous sequence of images of the web at a slower speed than a speed of the moving web.

18. The web inspection system of claim 1 wherein the web of material is selected from the group consisting of paper, film, metal and textile.

19. The web inspection system of claim 1 wherein the web of moving material travels at a speed of up to approximately 1500 meters/second.

20. The web inspection system of claim 1 wherein said inspection system is operative to detect defects greater than approximately twenty five microns.

21. The web inspection system of claim 1 wherein said image processing system is operative to build an image database of defect images detected.

22. The web inspection system of claim 1 wherein said image processing system is operative to identify and classify detected defects.

23. The web inspection system of claim 1 wherein said image processing system is operative to sort and display detected defects.

24. The web inspection system of claim 1 wherein said continuous sequence of real time images are provided as digital images.

25. The web inspection system of claim 1 wherein said inspection system is operative to view a web up to approximately ten meters wide.