Apparatus and method for providing snapshot action thermal infrared imaging within automated process control article inspection applications

• US 8,097,857 B2
• Filed: 08/21/2002
• Issued: 01/17/2012
• Est. Priority Date: 05/21/2001
• Status: Active Grant

• Current Assignee: Pressco Technology Inc.
• Original Assignee: Pressco Technology Inc.
• Inventors: Cochran, Don W., Cech, Steven D.
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): VU, MINDY D
• Application Number:
  US10/526,799
• Publication Number:
  US 20060232674A1
• Time in Patent Office: 3,436 Days
• Field of Search: 250/358.1
• US Class Current: 250/358.1
• CPC Class Codes: G01J 2005/0077 Imaging
• CPC Class Codes: G01N 2021/845 Objects on a conveyor
• CPC Class Codes: G01N 21/88 Investigating the presence of flaws or contamination
• CPC Class Codes: G01N 21/89 in moving material, e.g. running paper or textiles G01N21/90, G01N21/91, G01N21/94 take precedence
• CPC Class Codes: G01N 25/72 Investigating presence of flaws
• CPC Class Codes: H01L 27/1467 of the hybrid type
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

This application relates to an apparatus and method for providing snapshot action thermal infrared imaging within automated process control article inspection applications. More specifically, it pertains to the use of snapshot mode lead salt area-array imaging sensors (20) as the imaging front-end in high-speed machine vision inspection systems (12). the relatively low-cost, good measurement sensitivity at temperatures consistent with thereto-electric cooling means, and the ability to be operated in snap-shot mode enables lead salt-based image acquisition sensors (20) to be used in a variety of automated process control and article inspection applications.

Claims

1. A system for providing snapshot action thermal imaging within a high speed automated process control article inspection environment comprising:

a lead salt-based thermal infrared imager configured to support snapshot-mode image acquisition in the high speed environment;

an image acquisition zone configured to support the snapshot-mode image acquisition of a part or process being presented at a high rate of speed;

an image processor configured to receive and process output of the imager in a manner which reduces a two-dimensional infrared spatial image or data set produced by the imager into a specific set of quality- or process-related attributes associated with the part or process within the image acquisition zone; and

,

a control electronics module configured to provide image acquisition control signals within the system.

2. The system as set forth in claim 1 further comprising an automated conveyance device used to dynamically present a stream of parts in rapid succession to the system.

3. The system as set forth in claim 2 further comprising a part detect or presence sensing device which interfaces to the control electronics module and provides the system an indication of the presence of a part requiring inspection.

4. The system as set forth in claim 1 further comprising a thermal baffle disposed within the inspection zone to shield the imager from deleterious thermal infrared energy emanating from uncontrolled or non-preferred sources.

5. The system as set forth in claim 4 wherein the thermal baffle comprises high emissivity surfaces to facilitate absorption of the deleterious thermal infrared energy.

6. The system as set forth in claim 5 wherein the thermal baffle is actively cooled to reduce self-emission of thermal infrared energy.

7. The system as set forth in claim 6 wherein the thermal baffle is cooled using thermo-electric coolers.

8. The system as set forth in claim 1 further comprising a thermal energy stimulus used for imparting thermal energy to the part or process for differentiating defective parts from acceptable parts.

9. The system as set forth in claim 8 wherein the thermal energy stimulus is implemented as an induction-type heater.

10. The system as set forth in claim 8 wherein the thermal energy stimulus is implemented as an ultrasonic heater.

11. The system as set forth in claim 8 wherein the thermal energy stimulus is implemented as a microwave source.

12. The system as set forth in claim 8 wherein the thermal energy stimulus is implemented as a spatially-directed high power laser.

13. The system as set forth in claim 8 wherein the thermal energy stimulus is implemented as a blackbody emitter.

14. The system as set forth in claim 3 wherein the blackbody emitter is implemented as a lamp.

15. The system set forth in claim 14 wherein the lamp is implemented as a quartz halogen lamp.

16. The system as set forth in claim 14 wherein the thermal energy emitted by the lamp is exchanged by way of natural convection.

17. The system as set forth in claim 14 wherein the thermal energy emitted by the lamp is exchanged by way of forced air flow.

18. The system as set forth in claim 13 wherein the blackbody emitter is implemented as a glowbar.

19. The system as set forth in claim 18 wherein the energy emitted by the glowbar is exchanged by way of natural convection.

20. The system as set forth in claim 18 wherein the energy emitted by the glowbar is exchanged by way of forced air.

21. The system as set forth in claim 1 wherein thermal infrared energy is added to the part by electrically energizing components associated with the part.

22. The system as set forth in claim 1 further comprising a status enunciator used to indicate a status of the part or process under inspection.

23. The system as set forth in claim 22 wherein the status enunciator is implemented as a mechanical reject mechanism which acts to remove specific parts from a manufacturing process when such parts are determined to be below or, alternately, above a predefined quality level.

24. The system as set forth in claim 23 wherein the reject mechanism is an air valve.

25. The system as set forth in claim 23 wherein the reject mechanism is a solenoid actuator.

26. The system as set forth in claim 22 wherein the status enunciator is implemented as a marking device which acts to mark parts determined to be below or, alternately, above a predefined quality level.

27. The system as set forth in claim 22 wherein the status enunciator is implemented as a print or display report writer that acts to provide a part-by-part quality report.

28. The system as set forth in claim 22 wherein the status enunciator is implemented as a print or display report writer that acts to provide a cumulative archive of article quality.

29. The system as set forth in claim 22 wherein the status enunciator is implemented as a module that electronically communicates part or process status in a manner which facilitates closed loop control of a manufacturing process.

30. A method for providing snapshot action thermal infrared imaging within a high steed automated process control article inspection environment, the method comprising the steps of:

simultaneously integrating thermal infrared signals within all pixel sites of a lead salt-based imager based on image acquisition control signals provided by an electronics control module;

providing a two-dimensional infrared spatial image or data set based on the pixel site integrating to a processor; and

,

processing the two-dimensional infrared spatial image or data set into a set of quality- or process-related attributes associated with a part or process under inspection being presented at a high rate of speed.

31. The method as set forth in claim 30 further comprising the step of automatically conveying objects to be inspected into an inspection zone.

32. The method as set forth in claim 30 further comprising the step of applying thermal energy to parts under inspection for the purpose of differentiating defective parts from acceptable parts.

33. The method as set forth in claim 30 further comprising the step of generating a status report based on the processing.

34. The method as set forth in claim further comprising the step of proving the status report to a status enunciator.

35. The method as set forth in claim 34 further comprising the step of using the status report to automatically alter parameters of a manufacturing process.

36. A method for providing snapshot action thermal infrared imaging within a high speed automated process control article inspection environment, the method comprising the steps of:

energizing components within an inspected part or process by applying a controlled voltage or current to the components;

simultaneously integrating thermal infrared signals within all pixel sites of a lead salt-based imager based on image acquisition control signals provided by an electronics control module;

providing a sequence of two-dimensional infrared spatial ages or data sets based on the pixel site integrating to a processor; and

,

processing the two-dimensional infrared spatial images or data sets into a set of quality- or process-related attributes associated with a part or process under inspection being presented at a high rate of speed.

37. The method as set forth in claim 36 further comprising the step of generating a status report based on the processing.

38. The method as set forth in claim 37 further comprising the step of providing the status report to a status enunciator.

39. The method as set forth in claim 38 further comprising the step of using the status report to automatically alter parameters of a manufacturing process.