Apparatus and method for measuring optical characteristics of an object

• US 6,501,542 B2
• Filed: 12/29/1999
• Issued: 12/31/2002
• Est. Priority Date: 06/30/1998
• Status: Expired due to Fees

• Current Assignee: RPX Corporation
• Original Assignee: LJ Laboratories L.L.C.
• Inventors: Jung, Wayne D., Jung, Russell W., Loudermilk, Alan R.
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): MERLINO, AMANDA H
• Application Number:
  US09/462,020
• Publication Number:
  US 20020024653A1
• Time in Patent Office: 1,098 Days
• Field of Search: 356/73, 356/317-319, 356/326, 356/328, 356/371, 356/416, 356/417, 356/419, 356/445, 356/446, 433/29
• US Class Current: 356/73
• CPC Class Codes: G01J 2003/2866 Markers; Calibrating of scan
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0205 Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows
• CPC Class Codes: G01J 3/0216 using light concentrators or collectors or condensers
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/027 Control of working procedures of a spectrometer; Failure detection; Bandwidth calculation
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/0278 Control or determination of height or angle information for sensors or receivers
• CPC Class Codes: G01J 3/04 Slit arrangements slit adjustment
• CPC Class Codes: G01J 3/508 measuring the colour of teeth
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: G01N 21/03 Cuvette constructions

Abstract

Optical characteristic measuring systems and methods for determining the color or other optical characteristics of teeth comprising a probe body (2) wherein the probe provides light to the surface of the object (20). Perimeter receiver fiber optics (102) are spaced apart from a source fiber optic and receive light from the surface of the object (20) being measured. Light from the perimeter fiber optics passes to a variety of filters. The system utilizes the perimeter receiver fiber optics to determine information regarding the height and angle of the probe with respect to the object being measured wherein the numerical apertures of the receiver fiber optics are different.

Claims

1. A method comprising the steps of:

moving a probe towards an object, wherein the probe provides light to an object from at least one light source, and receives light from the object through at least one light receiver, wherein the light source has a first numerical aperture during at least a portion of the movement of the probe towards the object;

moving the probe away from the object, wherein the probe provides light to the object from the at least one light source, and receives light from the object through the at least one light receiver, wherein the light source has a second numerical aperture during at least a portion of the movement of the probe away from the object;

determining the intensity of light received by the at least one light receiver during the movement of the probe towards the object and during the movement away from the object; and

measuring the optical characteristics of the object, wherein the measurement produces data indicative of the optical characteristics of the object.

2. The method of claim 1, wherein the numerical aperture of the at least one light source is varied with an iris.

3. The method of claim 2, wherein the iris controls angles of light entering a light source fiber optic.

4. The method of claim 1, wherein the numerical aperture of the at least one light source is varied by passing light through an aperture disk.

5. The method of claim 4, wherein the aperture disk has a plurality of regions, wherein at least some of the plurality of regions have apertures of different light transmission properties.

6. The method of claim 5, wherein light is selectively transmitted through the apertures of different light transmission properties, wherein the numerical aperture of the at least one light source is varied.

7. The method of claim 5, wherein light is selectively transmitted through the apertures of different light transmission properties, wherein spectral properties of the at least one light source are varied.

8. The method of claim 5, wherein at least one of the plurality of regions includes a filter or diffraction grating or other optical implement to alter the light from the at least one source.

9. The method of claim 5, wherein an angle of light entering a light source fiber is varied.

10. The method of claim 6, wherein the aperture disk is controlled by a stepping motor, wherein light is selectively transmitted through the apertures of different light transmission properties.

11. The method of claim 1, wherein the probe comprises a plurality of light receivers, wherein the plurality of light receivers comprise one or more first light receivers and one or more second light receivers, wherein the one or more first light receivers have a third numerical aperture and the one or more second light receivers have a fourth numerical aperture different from the third numerical aperture.

12. The method of claim 1, wherein the optical characteristics of the object comprise color characteristics.

13. The method of claim 1, wherein the optical characteristics of the object comprise translucence characteristics.

14. The method of claim 1, wherein the optical characteristics of the object comprise fluorescence characteristics.

15. The method of claim 1, wherein the optical characteristics of the object comprise surface texture characteristics.

16. The method of claim 1, wherein the optical characteristics of the object comprise gloss characteristics.

17. The method of claim 1, wherein the optical characteristics of the object comprise opalescence characteristics.

18. The method of claim 1, wherein the object comprises an object selected from the group consisting of a dental object, a gem, a document or a painted object.

19. The method of claim 1, wherein the received light is spectrally analyzed by a plurality of sensors, wherein light is coupled to the plurality of sensors via a plurality of filter elements.

20. The method of claim 19, wherein the plurality of sensors comprise a CCD array or a photodiode array.

21. The method of claim 19, wherein the plurality of sensors comprise a plurality of light-to-frequency converters.

22. The method of claim 19, wherein the plurality of filter elements collectively comprise a color gradient filter.

23. The method of claim 19, wherein the plurality of filter elements comprise a plurality of interference filters.

24. A method comprising the steps of:

providing with a probe first light having a plurality of wavelengths to an object, wherein the first light is provided from a source that has a first numerical aperture;

receiving with the probe first light from the object and taking a first measurement that includes a spectral analysis of the received first light;

providing with a probe second light having a plurality of wavelengths to the object, wherein the second light is provided from a source that has a second numerical aperture different from the first numerical aperture;

receiving with the probe second light from the object and taking a second measurement that includes a spectral analysis of the received second light; and

quantifying the optical properties of the object based on the first and second measurements.

25. The method of claim 24, wherein the first light and the second light are provided from a common light source, wherein the numerical aperture of the common light source is varied.

26. The method of claim 25, wherein the numerical aperture of the common light source is varied with an iris.

27. The method of claim 26, wherein the iris controls angles of light entering a light source fiber optic.

28. The method of claim 27, wherein the first light and the second light are provided from a common light source, wherein the numerical aperture of the common light source is varied by passing light through an aperture disk.

29. The method of claim 28, wherein the aperture disk has a plurality of regions, wherein at least some of the plurality of regions have apertures of different light transmission properties.

30. The method of claim 28, wherein light is selectively transmitted through the apertures of different light transmission properties, wherein the numerical aperture of the common light source is varied.

31. The method of claim 28, wherein light is selectively transmitted through the apertures of different light transmission properties, wherein spectral properties of the common light source are varied.

32. The method of claim 29, wherein at least one of the plurality of regions includes a filter or diffraction grating or other optical implement to alter the light from the at least one source.

33. The method of claim 25, wherein an angle of light entering a light source fiber is varied.

34. The method of claim 28, wherein the aperture disk is controlled by a stepping motor, wherein light is selectively transmitted through the apertures of different light transmission properties.

35. The method of claim 24, wherein the probe comprises a plurality of light receivers, wherein the plurality of light receivers comprise one or more first light receivers and one or more second light receivers, wherein the one or more first light receivers have a third numerical aperture and the one or more second light receivers have a fourth numerical aperture different from the third numerical aperture.

36. The method of claim 24, wherein the optical characteristics of the object comprise color characteristics.

37. The method of claim 24, wherein the optical characteristics of the object comprise translucence characteristics.

38. The method of claim 24, wherein the optical characteristics of the object comprise fluorescence characteristics.

39. The method of claim 24, wherein the optical characteristics of the object comprise surface texture characteristics.

40. The method of claim 24, wherein the optical characteristics of the object comprise gloss characteristics.

41. The method of claim 24, wherein the optical characteristics of the object comprise opalescence characteristics.

42. The method of claim 24, wherein the object comprises an object selected from the group consisting of a dental object, a gem, a document or a painted object.

43. The method of claim 24, wherein the first and second measurements are taken when the probe is at a first distance from the object.

44. The method of claim 24, wherein the first and second measurements are taken when the probe is at first and second distance from the object, respectively.

45. The method of claim 24, wherein the received first and second light is spectrally analyzed by a plurality of sensors, wherein light is coupled to the plurality of sensors via a plurality of filter elements.

46. The method of claim 45, wherein the plurality of sensors comprise a CCD array or a photodiode array.

47. The method of claim 45, wherein the plurality of sensors comprise a plurality of light-to-frequency converters.

48. The method of claim 45, wherein the plurality of filter elements collectively comprise a color gradient filter.

49. The method of claim 45, wherein the plurality of filter elements comprise a plurality of interference filters.

50. A method comprising the steps of:

providing first light having a plurality of wavelengths to an object, wherein the first light is provided from a source that has a first numerical aperture;

receiving first light from the object and taking a first measurement that includes a spectral analysis of the received first light;

providing second light having a plurality of wavelengths to the object, wherein the second light is provided from a source that has a second numerical aperture different from the first numerical aperture;

receiving second light from the object and taking a second measurement that includes a spectral analysis of the received second light; and

quantifying the optical properties of the object based on the first and second measurements.

51. The method of claim 50, wherein the first light and the second light are provided from a common light source, wherein the numerical aperture of the common light source is varied.

52. The method of claim 51, wherein the numerical aperture of the common light source is varied with an iris.

53. The method of claim 52, wherein the iris controls angles of light entering a light source fiber optic.

54. The method of claim 50, wherein the first light and the second light are provided from a common light source, wherein the numerical aperture of the common light source is varied by passing light through an aperture disk.

55. The method of claim 54, wherein the aperture disk has a plurality of regions, wherein at least some of the plurality of regions have apertures of different light transmission properties.

56. The method of claim 54, wherein light is selectively transmitted through the apertures of different light transmission properties, wherein the numerical aperture of the common light source is varied.

57. The method of claim 54, wherein light is selectively transmitted through the apertures of different light transmission properties, wherein spectral properties of the common light source are varied.

58. The method of claim 55, wherein at least one of the plurality of regions includes a filter or diffraction grating or other optical implement to alter the light from the at least one source.

59. The method of claim 51, wherein an angle of light entering a light source fiber is varied.

60. The method of claim 54, wherein the aperture disk is controlled by a stepping motor, wherein light is selectively transmitted through the apertures of different light transmission properties.

61. The method of claim 50, wherein the method comprises moving a probe in proximity to the object, wherein the probe comprises a plurality of light receivers, wherein the plurality of light receivers comprise one or more first light receivers and one or more second light receivers, wherein the one or more first light receivers have a third numerical aperture and the one or more second light receivers have a fourth numerical aperture different from the third numerical aperture.

62. The method of claim 61, wherein the probe emits the first light and the second light.

63. The method of claim 50, wherein the optical characteristics of the object comprise color characteristics.

64. The method of claim 50, wherein the optical characteristics of the object comprise translucence characteristics.

65. The method of claim 50, wherein the optical characteristics of the object comprise fluorescence characteristics.

66. The method of claim 50, wherein the optical characteristics of the object comprise surface texture characteristics.

67. The method of claim 50, wherein the optical characteristics of the object comprise gloss characteristics.

68. The method of claim 50, wherein the optical characteristics of the object comprise opalescence characteristics.

69. The method of claim 50, wherein the object comprises an object selected from the group consisting of a dental object, a gem, a document or a painted object.

70. The method of claim 50, wherein the first and second measurements are taken when the probe is at a first distance from the object.

71. The method of claim 51, wherein the first and second measurements are taken when the probe is at first and second distance from the object, respectively.

72. The method of claim 50, wherein the received first and second light is spectrally analyzed by a plurality of sensors, wherein light is coupled to the plurality of sensors via a plurality of filter elements.

73. The method of claim 72, wherein the plurality of sensors comprise a CCD array or a photodiode array.

74. The method of claim 72, wherein the plurality of sensors comprise a plurality of light-to-frequency converters.

75. The method of claim 72, wherein the plurality of filter elements collectively comprise a color gradient filter.

76. The method of claim 72, wherein the plurality of filter elements comprise a plurality of interference filters.