Laser position array optical measuring system and method

• US 6,346,988 B1
• Filed: 08/01/1997
• Issued: 02/12/2002
• Est. Priority Date: 08/01/1997
• Status: Expired due to Fees

• Current Assignee: CyberOptics Semiconductor, Inc. (Nordson Corporation)
• Original Assignee: Hama Sensors Inc. (Nordson Corporation)
• Inventors: Cerny, Mark, Bartunek, Hans
• Primary Examiner(s): Evans, F. L.
• Assistant Examiner(s): Smith, Zandra V
• Application Number:
  US08/904,950
• Time in Patent Office: 1,656 Days
• Field of Search: 356/384, 356/385, 356/376, 356/396, 356/386, 250/559.12, 250/559.13, 250/559.14, 250/559.15, 348/312, 348/322
• US Class Current: 356/635
• CPC Class Codes: G01B 11/2433 for measuring outlines by shadow casting

Abstract

An optical measuring system capable of high resolution measurement of objects, and a method of measuring the same, are provided. The optical measuring system is formed in one integral, portable unit, and includes a laser source having associated optics for emitting a wide collimated light beam. A CCD receiver and a processor housed together and spaced apart from the laser source receive the wide collimated light beam. The CCD receiver has a plurality of diode cells, or “pixels,” formed in a linear array, and the diode cells exhibit output signals corresponding to the received light beam. The processor processes the output signals and determines a measurement associated with the output signals.

Claims

1. An optical measuring system for measuring an object, comprising:

an integral unit containing a laser source having associated optics for emitting a wide collimated light beam; and

a CCD receiver and a processor housed together and spaced apart from said laser source, said CCD receiver including a plurality of diode cells formed in a linear array, for receiving said light beam and wherein each of said diode cells exhibit output signals corresponding to the amount of received light, the linear array of diode cells and the light beam being at least as wide as the object;

said processor receiving said output signals and generating a measurement signal corresponding to said output signals of said plurality of diode cells;

wherein said CCD receiver further includes;

a semi-transparent mirror for receiving said light beam and splitting said light beam into first and second light portions; and

a plurality of first and second arrays of diode cells, said first array receiving said first light portion, and said second array for receiving said second light portion.

2. The system of claim 1 wherein said CCD receiver includes a CCD clock and said processor includes means for sampling said output signal at a rate greater than said clock.

3. The system of claim 2 wherein said output signal is sampled at a rate of at least twice said CCD clock.

4. The system of claim 1 wherein said processor further includes a low pass filter for filtering said output signal.

5. The system of claim 1 wherein said processor further comprises:

a low pass filter for filtering said output signal;

an analog to digital convertor for digitizing said output signal; and

said interpolator for sampling said output signal at a selected frequency.

6. The system of claim 1 wherein said processor further includes a digital filter having a preselected value wherein said output signal is shifted by said preselected value.

7. The system of claim 1 wherein said processor further includes means for selecting a portion of said light beam for processing and generating an output signal corresponding to the light detection characteristics of the portion of said light beam.

8. The system of claim 1 wherein said measurement associated with said measurement signal is a spatial measurement.

9. The system of claim 1 wherein said measurement associated with said measurement signal is a size measurement.

10. The system of claim 1 wherein said laser source is pulsed.

11. The system of claim 1 wherein said processor includes

an analog circuit;

and

a digital circuit, said digital circuit being comprised of a field programmable gate array.

12. The system of claim 1 wherein said laser source further comprises a plurality of lasers each having associated optics for emitting a plurality of collimated light beam segments, and said collimated light beam segments form said wide collimated light beam.

13. The system of claim 1, wherein said optics are configured to emit said wide collimated light beam with substantially zero aberration.

14. An optical measuring system for measuring an object, comprising:

an integral unit containing a laser source having associated optics for emitting a wide collimated light beam;

a CCD receiver and a processor housed together and spaced apart from said laser source, said CCD receiver including a plurality of diode cells formed in a linear array, for receiving said light beam and wherein each of said diode cells exhibit output signals corresponding to the amount of received light beam; and

said processor for generating a measurement signal corresponding to said output signals of said plurality of diode cells, and determining a measurement of the object placed in said light beam, said processor including;

a low pass filter for filtering said output signal;

an analog to digital convertor for digitizing said output signal; and

a field programmable gate array having an interpolator for sampling said output signal at a selected frequency.

15. The system of claim 14 wherein said processor further includes a digital filter having a preselected value wherein said output signal is shifted by said preselected value.

16. The system of claim 14 wherein said processor further includes means for selecting a portion of said light beam for processing and generating an output signal corresponding to the light detection characteristics of the portion of said light beam.

17. The system of claim 14 wherein said laser source is pulsed.

18. The system of claim 14 wherein said optics are configured to emit said wide collimated light beam with substantially zero aberration.

19. The system of claim 14 wherein said laser source further comprises a plurality of lasers each having associated optics for emitting a plurality of collimated light beam segments, and said collimated light beam segments form said wide collimated light beam.

20. The system of claim 14 wherein said CCD receiver further includes:

a semi-transparent mirror for receiving said light beam and splitting said light beam into first and second light portions; and

a plurality of first and second arrays of diode cells, said first array receiving said first light portion, and said second array for receiving said second light portion.

21. A method of measuring an object, comprising:

emitting a wide collimated light beam from a laser source;

receiving said light beam at a CCD receiver having a CCD clock and a plurality of diode cells formed in a linear array and being spaced apart from said laser source;

activating said diode cells, wherein said diode cells exhibit light detection characteristics corresponding to said received light beam;

generating an output signal corresponding to the light detection characteristics;

interpolating said output signal at a selected frequency;

determining a measurement associated with said output signal; and

filtering said out-put signal by a preselected value wherein said output signal is shifted by said preselected value.

22. The method of claim 21 further comprising the steps of:

filtering said output signal with a low pass filter;

digitizing said output signal;

interpolating said output signal by sampling said output signal at a frequency greater than the frequency of said CCD clock; and

determining a measurement associated with said output signal.

23. The method of claim 21 further comprising:

filtering said output signal by a preselected value wherein said output signal is shifted by said preselected value.

24. The method of claim 21 further comprising:

selecting a portion of said light beam for processing; and

generating an output signal corresponding to the light detection characteristics of the portion of said light beam.

25. The method of claim 21 wherein said measurement associated with said output signal is a spatial measurement.

26. The method of claim 21 wherein said measurement associated with said output signal is a size measurement.

27. The method of claim 21 wherein the step of emitting a wide collimated light beam from a laser source further comprises:

pulsing said laser source.

28. A method of measuring an object, comprising:

emitting a wide collimated light beam from a laser source;

receiving said light beam at a CCD receiver having a CCD clock and a plurality of diode cells formed in a linear array and being spaced apart from said laser source;

activating said diode cells, wherein said diode cells exhibit light detection characteristics corresponding to said received light beam;

generating an output signal corresponding to the light detection characteristics;

filtering said output signal with a low pass filter;

digitizing said output signal;

interpolating said output signal by sampling said output signal at a frequency greater than the frequency of said CCD clock;

determining a measurement associated with said output signal; and

filtering said output signal by a preselected value wherein said output signal is shifted by said preselected value.

29. The method of claim 28 further comprising:

selecting a portion of said light beam for processing; and

generating an output signal corresponding to the light detection characteristics of the portion of said light beam.

30. An optical measuring system for measuring an object, comprising:

an integral unit containing a laser source having a plurality of lasers each including associated optics for emiting a pluralty of collimated light beam segments, and said collimated light beam segments forming a wide collimated light beam;

a CCD receiver and a processor housed together and spaced apart from said laser source, said CCD receiver for receiving said light beam, said CCD receiver including a semi-transparent mirror for receiving said light beam and splitting said light beam into first and second light portions, and a plurality of first and second arrays of diode cells, said first arrays receiving said first light portion, and said second arrays for receiving said second light portion, wherein each of said diode cells exhibit output signals corresponding to the amount of received light beam; and

said processor for generating a measurement signal corresponding to said output signals of said plurality of diode cells, for determining a measurement of the object placed in said light beam, said processor including;

a low pass filter for filtering said output signal;

an analog to digital convertor for digitizing said output signal; and

a field programmable gate array having an interpolator for sampling said output signal at a selected frequency.

31. The system of claim 30 wherein said processor further includes means for selecting a portion of said light beam for processing and generating an output signal corresponding to the light detection characteristics of the portion of said light beam.

32. The system of claim 30 wherein said laser source is pulsed.

33. The system of claim 30 wherein said optics are configured to emit said wide collimated light beam with substantially zero aberration.

34. An optical measuring system for measuring an object, comprising:

an integral unit containing a laser source having associated optics for emitting a wide collimated light beam; and

a CCD receiver and a processor housed together and spaced apart from said laser source, said CCD receiver including a plurality of diode cells formed in a linear array, for receiving said light beam and wherein each of said diode cells exhibit output signals corresponding to the amount of received light, the linear array of diode cells and the light beam being at least as wide as the object;

said processor receiving said output signals and generating a measurement signal corresponding to said output signals of said plurality of diode cells, wherein said processor includes an analog circuit and a digital circuit, said digital circuit being comprised of a field programmable gate array;

wherein said processor further includes a digital filter having a preselected value wherein said output signal is shifted by said preselected value.

35. The system of claim 34 wherein said CCD receiver includes a CCD clock and said processor includes means for sampling said output signal at a rate greater than said clock.

36. The system of claim 34 wherein said processor further includes means for selecting a portion of said light beam for processing and generating an output signal corresponding to the light detection characteristics of the portion of said light beam.

37. An optical measuring system for measuring an object, comprising:

an integral unit containing a laser source having associated optics for emitting a wide collimated light beam; and

a CCD receiver and a processor housed together and spaced apart from said laser source, said CCD receiver including a plurality of diode cells formed in a linear array, for receiving said light beam and wherein each of said diode cells exhibit output signals corresponding to the amount of received light;

said processor receiving said output signals and generating a measurement signal corresponding to said output signals of said plurality of diode cells;

wherein said laser source further comprises a plurality of lasers each having associated optics for emitting a plurality of collimated light beam segments, and said collimated light beam segments form said wide collimated light beam.

38. The system of claim 37 wherein said CCD receiver includes a CCD clock and said processor includes means for sampling said output signal at a rate greater than said clock.

39. The system of claim 37 wherein said processor further includes a digital filter having a preselected value wherein said output signal is shifted by said preselected value.

40. The system of claim 37 wherein said processor further includes means for selecting a portion of said light beam for processing and generating an output signal corresponding to the light detection characteristics of the portion of said light beam.

41. An optical measuring system for measuring an object, comprising:

an integral unit containing a laser source having associated optics for emitting a wide collimated light beam; and

a CCD receiver and a processor housed together and spaced apart from said laser source, said CCD receiver including a plurality of diode cells formed in a linear array, for receiving said light beam and wherein each of said diode cells exhibit output signals corresponding to the amount of received light;

said processor receiving said output signals and generating a measurement signal corresponding to said output signals of said plurality of diode cells, said processor including an interpolator for sampling said output signals at a selected frequency;

wherein said CCD receiver further includes a semi-transparent mirror for receiving said light beam and splitting said light beam into first and second light portions, and a plurality of first and second arrays of diode cells, said first array receiving said first light portion, and said second array receiving said second light portion.

42. The system of claim 41 wherein said CCD receiver includes a CCD clock and said processor includes means for sampling said output signal at a rate greater than said clock.

43. The system of claim 41 wherein said processor further includes a digital filter having a preselected value wherein said output signal is shifted by said preselected value.

44. The system of claim 41 wherein said processor further includes means for selecting a portion of said light beam for processing and generating an output signal corresponding to the light detection characteristics of the portion of said light beam.

45. An optical measuring system for measuring an object, comprising:

an integral unit containing a laser source having associated optics for emitting a wide collimated light beam; and

a CCD receiver and a processor housed together and spaced apart from said laser source, said CCD receiver including a plurality of diode cells formed in a linear array, for receiving said light beam and wherein each of said diode cells exhibit output signals corresponding to the amount of received light, the linear array of diode cells and the light beam being at least as wide as the object;

said processor receiving said output signals and generating a measurement signal corresponding to said output signals of said plurality of diode cells;

wherein said laser source further comprises a plurality of lasers each having associated optics for emitting a plurality of collimated light beam segments, and said collimated light beam segments form said wide collimated light beam.