Multi-wavelength laser check detection tool

• US 10,012,598 B2
• Filed: 06/27/2016
• Issued: 07/03/2018
• Est. Priority Date: 07/17/2015
• Status: Expired due to Fees

• Current Assignee: Emhart Glass SA (Bucher Industries AG)
• Original Assignee: Emhart Industries, Inc. (Stanley Black & Decker, Inc.)
• Inventors: Huibregtse, David, French, Scott L.
• Primary Examiner(s): Ahmed, Jamil
• Application Number:
  US15/194,088
• Publication Number:
  US 20170016833A1
• Time in Patent Office: 736 Days
• CPC Class Codes: G01N 2021/8845 Multiple wavelengths of illumination or detection
• CPC Class Codes: G01N 21/9036 using arrays of emitters or receivers
• CPC Class Codes: G01N 21/9054 Inspection of sealing surface and container finish
• CPC Class Codes: G01N 2201/06113 Coherent sources; lasers

Abstract

A device and method for inspecting glass containers and particularly the finish of glass containers is provided. The glass container inspection device includes a rotator rotates a glass container located in an inspection location at least 360 degrees. A first laser source produces a first laser beam which is directed towards the inspection location to form an angle of incidence with the selected glass container being greater than or equal to a critical angle for producing internal reflection of the first laser beam within the selected glass container. A camera is directed at the inspection location to detect light that escapes from the selected glass container as a result of the internally reflected laser beam intersecting a defect in the selected glass container.

Claims

1. A glass container inspection device for inspecting a finish region of the glass container comprising:

a rotator configured to rotate a selected glass container located in an inspection location at least 360 degrees;

a first laser source configured to produce a first collimated laser beam, the first laser source being configured to direct the first collimated laser beam towards the inspection location, the first collimated laser beam forming an angle of incidence with the selected glass container being greater than or equal to a critical angle for producing internal reflection of the first collimated laser beam within the selected glass container; and

a camera directed at the inspection location for detecting light that escapes from the selected glass container as a result of the internally reflected first collimated laser beam intersecting a defect in the selected glass container;

an alignment mechanism for simultaneously adjusting a position of the first laser source and the camera parallel to a plane normal to a container axis of rotation about which the selected glass container is rotated by the rotator;

an alignment guide being carried with the camera and the first laser source when the alignment mechanism adjusts the position of the first laser source and the camera, the alignment guide defining a pair of alignment lines extending at a right angle to one another in the plane normal, wherein both alignment lines are positioned tangent to an outer periphery of a selected glass container within the inspection location when viewed along the container axis of rotation to set a position of the alignment mechanism.

2. The glass container inspection device of claim 1, wherein the first laser source is a multi-wavelength laser source configured such that the first collimated laser beam is a multi-wavelength collimated laser beam, the multi-wavelength laser source including:

a first wavelength laser source configured to produce a first wavelength collimated laser beam of a first wavelength of light;

a second wavelength laser source configured to produce a second wavelength collimated laser beam of a second wavelength of light different than the first wavelength of light; and

a third wavelength laser source configured to produce a third wavelength collimated laser beam of a third wavelength of light different than the first and second wavelengths of light;

the multi-wavelength light source configured to direct the multi-wavelength collimated laser beam towards the inspection location, the multi-wavelength collimated laser beam forming an angle of incidence with the selected glass container that is greater than or equal to a critical angle for producing total internal reflection of at least one of the first, second and third wavelength collimated laser beams of the multi-wavelength collimated laser beam within the selected glass container.

3. The glass container inspection device of claim 1, wherein the first wavelength of light is between 440-490 nm, the second wavelength of light is between 495-570 nm and the third wavelength of light is between 620-750 nm.

4. The glass container inspection device of claim 3, wherein the first wavelength of light is between 440-460 nm, the second wavelength of light is between 510-530 nm and the third wavelength of light is between 630-650 nm.

5. The glass container inspection device of claim 4, wherein the first laser source has an excitation source having a power value of between 5-150 milliwatts average power continuous wave.

6. The glass container inspection device of claim 5, wherein the first laser source is operably located and oriented relative to the inspection location such that the first collimated laser beam has a first dimension parallel to a first axis of between 20 and 60 millimeters and a second dimension along a second axis perpendicular to the first dimension and first axis of between 25 and 100 micrometers.

7. The glass container inspection device of claim 6, wherein the rotator rotates the selected glass container about a container axis of rotation, the first axis of the first collimated laser beam being at an angle of between 0 and 15 degrees relative to the container axis of rotation in a plane orthogonal to a focus axis of the first collimated laser beam.

8. The glass container inspection device of claim 1, further comprising a glass container transport arrangement for transporting the selected glass container into the inspection location, configured for stopping the selected glass container within the inspection location for a predetermined period of time at which time the rotator rotates the selected glass container at least 360 degrees, and configured for transporting the selected bottle out of the inspection location.

9. The glass container inspection device of claim 1, wherein the first laser source is configured to direct the first collimated laser beam towards the selected glass container at an angle of incidence of at least 65 degrees and less than 90 degrees.

10. The glass container inspection device of claim 1, wherein the camera defines a camera focus axis directed toward the inspection location, the camera focus axis extending angularly relative to a first laser focus axis of the first laser source along which the first collimated laser beam travels at a camera-to-laser angle of between 17 and 32 degrees.

11. The glass container inspection device of claim 10, wherein the first laser source and the camera are spaced from the inspection location such that the camera focus axis and the first laser focus axis intersect an outer periphery of a glass container within the inspection location prior to intersecting when the camera focus axis and the first laser focus axis are viewed in a direction extending parallel to a container axis of rotation about which the selected glass container is rotated by the rotator.

12. The glass container inspection device of claim 1, further including:

an alignment camera, the alignment camera positioned to view a selected glass container within the inspection location and the alignment lines, at least when, the alignment lines are both tangent to the outer periphery of the selected glass container; and

an alignment display operably connected to alignment camera displaying an output of the alignment camera.

13. The glass container inspection device of claim 2, further including first collimated laser beam delivery optics including:

a second laser source redirection structure optically interposed between the second laser source and the inspection location for redirecting the second wavelength collimated laser beam produced by the second wavelength laser source along a first laser focus axis;

a third wavelength laser source redirection structure optically interposed between the third wavelength laser source and the inspection location for redirecting the third wavelength collimated laser beam produced by the third wavelength laser source along the first laser focus axis such that the first, second and third wavelength collimated laser beams are coincident when they intersect an outer periphery of a selected glass container within the inspection location.

14. The glass container inspection device of claim 13, wherein the second wavelength laser source redirection structure is made of a material that allows the first wavelength of light to pass therethrough and the second wavelength of light is reflected and the third laser source redirection structure is made of a material that allows the first and second wavelengths of light to pass therethrough and the third wavelength of light is reflected.

15. The glass container inspection device of claim 14, further including a first laser source redirection structure optically interposed between the first laser source and the inspection location for redirecting the first wavelength collimated laser beam produced by the first wavelength laser source along the first laser focus axis.

16. The glass container inspection device of claim 1, wherein the first collimated laser beam of the first laser source travels along a first laser focus axis as the first collimated laser beam contacts an outer periphery of the selected glass container;

further including a fifth laser source configured to produce a fifth collimated laser beam traveling along a fifth laser focus axis different than the first laser focus axis, the fifth laser source being configured to direct the fifth collimated laser beam towards the selected glass container in the inspection location at a fifth angle of incidence with the selected glass container being greater than or equal to a critical angle for producing internal reflection of the fifth collimated laser beam within the selected glass container, the fifth laser focus axis being at a skew angle relative to a plane normal to a container axis of rotation about which the rotator rotates the selected glass container.

17. The glass container inspection device of claim 16, wherein the second laser focus axis is directed to intersect an inside of an opening of the selected glass container such that horizontal defects can be detected using a second camera.

18. The glass container inspection device of claim 1, wherein the rotator is configured to rotate the selected glass container at least 720 degrees while in the inspection location.

19. The glass container inspection device of claim 1, further comprising a fourth laser source configured to produce a fourth collimated laser beam, the fourth laser source being configured to direct the fourth collimated laser beam towards the inspection location to form an angle of incidence with the selected glass container being greater than or equal to a critical angle for producing internal reflection of the fourth collimated laser beam within the selected glass container;

and

a second camera directed at the inspection location for detecting light that escapes from the selected glass container as a result of the internally reflected fourth collimated laser beam intersecting a defect in the selected glass container;

the first and fourth laser sources being oriented such that the first and fourth collimated laser beams travel in opposite directions within the selected glass container.

20. A method of inspecting the finish region of the glass container comprising:

rotating a selected glass container located in an inspection location at least 360 degrees;

producing a first collimated laser beam with a first laser source;

directing the first collimated laser beam towards the inspection location, the first collimated laser beam forming an angle of incidence with the selected glass container being greater than or equal to a critical angle for producing internal reflection of the first collimated laser beam within the selected glass container;

detecting light that escapes from the selected glass container as a result of the internally reflected first collimated laser beam intersecting a defect in the selected glass container;

adjusting, simultaneously, a position of the first laser source and a camera for detecting light that escapes parallel to a plane normal to a container axis of rotation about which the selected glass container is rotated;

wherein adjusting the position of the first laser source and the camera includes using an alignment guide being carried with the camera and the first laser source when the position of the first laser source and the camera is adjusted, the alignment guide defining a pair of alignment lines extending at a right angle to one another in the plane normal; and

wherein adjusting the position of the first laser source and the camera includes aligning both alignment lines tangent to an outer periphery of a selected glass container within the inspection location when viewed along the container axis of rotation to set a position of the alignment mechanism.

21. The method of claim 20, wherein producing the first collimated laser beam includes producing a multi-wavelength collimated laser beam and the first laser source is a multi-wavelength laser source including a first, second and third wavelength laser source, producing the multi-wavelength collimated laser beam includes:

producing a first wavelength collimated laser beam of a first wavelength of light with the first wavelength laser source;

producing a second wavelength collimated laser beam of a second wavelength of light different than the first wavelength of light with the second wavelength laser source; and

producing a third wavelength collimated laser beam of a third wavelength of light different than the first and second wavelengths of light with the third wavelength laser source;

wherein directing the first collimated laser beam includes directing the multi-wavelength collimated laser beam towards the inspection location, the multi-wavelength collimated laser beam forming an angle of incidence with the selected glass container that is greater than or equal to a critical angle for producing total internal reflection of at least one of the first, second and third wavelength collimated laser beams of the multi-wavelength collimated laser beam within the selected glass container.

22. The method of claim 21, wherein the first wavelength of light is between 440-490 nm, the second wavelength of light is between 495-570 nm and the third wavelength of light is between 620-750 nm.

23. The method of claim 21, wherein the first wavelength of light is between 440-460 nm, the second wavelength of light is between 510-530 nm and the third wavelength of light is between 625-665 nm.

24. The method of claim 20, wherein the first laser source has an excitation source having a power value of between 5-150 milliwatts average power continuous wave.

25. The method of claim 20, wherein the first collimated laser beam has a first dimension parallel to a first axis of between 20 and 60 millimeters and a second dimension along a second axis perpendicular to the first dimension and first axis of between 25 and 100 micrometers.

26. The method of claim 25, wherein rotating the selected glass container includes rotating the selected glass container about a container axis of rotation, the first axis of the first collimated laser beam being at an angle of between 0 and 15 degrees relative to the container axis of rotation in a plane orthogonal to a focus axis of the first collimated laser beam.

27. The method of claim 20, further comprising:

transporting the selected glass container into the inspection location;

stopping the selected glass container within the inspection location for a predetermined period of time during which the step of rotating the selected glass container occurs while the selected glass container is stopped within the inspection location; and

transporting the selected bottle out of the inspection location.

28. The method of claim 20, wherein rotating includes rotating the selected glass container at least 720 degrees while in the inspection location.

29. The method of claim 20, wherein directing the first collimated laser beam includes directing the first collimated laser beam towards the selected glass container at an angle of incidence of at least 65 degrees and less than 90 degrees.

30. The method of claim 20, wherein detecting light that escapes from the selected glass container is performed using a line scan camera defining a camera focus axis directed toward the inspection location, the camera focus axis extending angularly relative to a first laser focus axis of the first laser source along which the first collimated laser beam travels at a camera-to-laser angle of between 17 and 32 degrees.

31. The method of claim 30, wherein the first laser source and the camera are spaced from the inspection location such that the camera focus axis and the first laser focus axis intersect an outer periphery of a glass container within the inspection location prior to intersecting when the camera focus axis and the first laser focus axis are viewed in a direction extending parallel to a container axis of rotation about which the selected glass container is rotated by the rotator.

32. The method of claim 20, wherein adjusting the position of the first laser source and the camera includes viewing a selected glass container within the inspection location and the alignment lines with an alignment camera and an alignment display operably connected to alignment camera displaying an output of the alignment camera.

33. The method of claim 21, wherein directing the multi-wavelength collimated laser beam includes, using first collimated laser beam delivery optics:

redirecting, with a second laser source redirection structure optically interposed between the second laser source and the inspection location, the second wavelength collimated laser beam produced by the second wavelength laser source along a first laser focus axis;

redirecting, with a third wavelength laser source redirection structure optically interposed between the third wavelength laser source and the inspection location, the third wavelength collimated laser beam produced by the third wavelength laser source along the first laser focus axis such that the first, second and third wavelength collimated laser beams are coincident when they intersect an outer periphery of a selected glass container within the inspection location.

34. The method of claim 33, wherein the second wavelength laser source redirection structure is made of a material that allows the first wavelength of light to pass therethrough and the second wavelength of light is reflected and the third laser source redirection structure is made of a material that allows the first and second wavelengths of light to pass therethrough and the third wavelength of light is reflected.

35. The method of claim 34, further including redirecting, with a first laser source redirection structure optically interposed between the first laser source and the inspection location, the first wavelength collimated laser beam produced by the first wavelength laser source along the first laser focus axis.

36. The method of claim 20, wherein directing the first collimated laser beam includes directing the first collimated laser beam of the first laser source along a first laser focus axis as the first collimated laser beam contacts an outer periphery of the selected glass container;

further including;

producing a second collimated laser beam, with a second laser source, traveling along a second laser focus axis different than the first laser focus axis;

directing the second collimated laser beam towards the selected glass container in the inspection location at a second angle of incidence with the selected glass container being greater than or equal to a critical angle for producing internal reflection of the second collimated laser beam within the selected glass container, the second laser focus axis being at a skew angle relative to a plane normal to a container axis of rotation about which the rotator rotates the selected glass container.

37. The method of claim 36, wherein directing the second collimated laser beam directs the second collimated laser beam such that the second laser focus axis is directed to intersect an inside of an 42 of the selected glass container such that horizontal defects are detected.

38. The method of claim 20, further comprising:

producing a second collimated laser beam with a second laser source;

directing the second collimated laser beam towards the inspection location at an angle of incidence with the selected glass container being greater than or equal to a critical angle for producing internal reflection of the second collimated laser beam within the selected glass container;

detecting light that escapes from the selected glass container as a result of the internally reflected second collimated laser beam intersecting a defect in the selected glass container; and

the first and second laser sources being directed such that the internally reflected first and second collimated laser beams travel in opposite directions within the selected glass container.