Spectrometric apparatus and method for measuring optical characteristics of an object

• US 6,583,866 B2
• Filed: 05/30/2002
• Issued: 06/24/2003
• Est. Priority Date: 01/10/2000
• 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): EVANS, FANNIE L
• Application Number:
  US10/160,843
• Publication Number:
  US 20020180968A1
• Time in Patent Office: 390 Days
• Field of Search: 356/305, 356/326, 356/328, 356/73
• US Class Current: 356/73
• CPC Class Codes: G01J 1/0242 Control or determination of height or angle information of sensors or receivers; Goniophotometry
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/06 Restricting the angle of incident light
• CPC Class Codes: G01J 3/02 Details
• 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 3/0254 Spectrometers, other than colorimeters, making use of an integrating sphere
• CPC Class Codes: G01J 3/0259 Monolithic
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• 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 3/0283 using a charging unit
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• 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

Abstract

Optical characteristic measuring systems and methods such as for determining the color or other optical characteristics of teeth are disclosed. Perimeter receiver fiber optics preferably are spaced apart from a source fiber optic and receive light from the surface of the object/tooth being measured. Light from the perimeter fiber optics pass 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/tooth being measured. Under processor control, the optical characteristics measurement may be made at a predetermined height and angle. Various color spectral photometer arrangements are disclosed. Translucency, fluorescence, gloss and/or surface texture data also may be obtained. Audio feedback may be provided to guide operator use of the system. The probe may have a removable or shielded tip for contamination prevention. A method of producing dental prostheses based on measured data also is disclosed. Measured data also may be stored and/or organized as part of a patient database. Such methods and implements may be desirably utilized for purposes of detecting and preventing counterfeiting or the like. Preferably, a two stage spectral separation is utilized, preferably utilizing a diffraction grating and interference filters.

Claims

1. A method for making spectral measurements with a reduced optical path length, diffraction grating-based, spectrometer device, comprising the steps of:

providing light to a diffraction grating, wherein the diffraction grating requires a first optical path length from the diffraction grating for a first predetermined spectral resolution of spectral measurement;

providing a plurality of filter elements and a plurality of optical sensors, wherein the plurality of filter elements are positioned in an optical path between the diffraction grating and the plurality of optical sensors;

receiving diffracted light from the diffraction grating with the plurality of optical sensors, wherein the light is incident upon and selectively transmitted through a plurality of the filter elements prior to being received by the plurality of optical sensors;

wherein spectral characteristics of the light provided to the diffraction grating are measured;

wherein the filter elements/optical sensors are positioned to define a second optical path length from the diffraction grating, wherein the second optical path length is less than the first optical path length, wherein the spectral characteristics of the light provided to the diffraction grating are measured in accordance with the first predetermined spectral resolution with a reduced optical path length;

wherein the light is provided to a material or object by a probe and light returned from the material or object is provided to the diffraction grating, wherein the method further comprises the step of providing light received from the material or object to second optical sensors, wherein the second optical sensors provide data indicative of a height or angle of the probe with respect to the material or object, provide data indicative of an optical value measurement of the material or object, or provide data indicative of translucence, gloss, opalescence, texture or other optical characteristics of the material or object.

2. method of claim 1, wherein the optical sensors comprise an array of optical sensors.

3. The method of claim 1, wherein the optical sensors comprise a linear array of optical sensors.

4. The method of claim 1, wherein the optical sensors comprise CCD sensors, photodiode sensors or phototransistor sensors.

5. The method of claim 1, wherein the filter elements comprise interference filters.

6. The method of claim 1, wherein the diffraction grating comprises a spherical diffraction grating.

7. The method of claim 1, wherein the light is provided to the material or object by one or more light sources.

8. The method of claim 7, wherein characteristics of the material or object are determined.

9. The method of claim 8, wherein the characteristics comprise spectral characteristics.

10. The method of claim 8, wherein the characteristics comprise whether the material or object contains a predetermined material.

11. The method of claim 8, wherein a determination is made if the object or material is genuine.

12. The method of claim 1, wherein the second optical sensors comprise light to frequency converters.

13. The method of claim 7, wherein the material or object comprises a gaseous material, a non-gaseous material, skin, non-skin body tissue, paint, fabric, a photograph, a dental object, a printed object, hair, or makeup.

14. The method of claim 1, wherein the spectrometer device comprises a handheld spectrometer.

15. The method of claim 1, wherein the spectrometer device comprises a handheld spectrophotometer.

16. The method of claim 1, wherein the diffraction grating is substantially curved in shape.

17. A method for making spectral measurements with a reduced optical path length, diffraction grating-based, spectrometer device, comprising the steps of:

providing light to a diffraction grating, wherein the diffraction grating requires a first optical path length from the diffraction grating for a first predetermined spectral resolution of spectral measurement;

providing a plurality of filter elements and a plurality of optical sensors, wherein the plurality of filter elements are positioned in an optical path between the diffraction grating and the plurality of optical sensors;

receiving diffracted light from the diffraction grating with the plurality of optical sensors, wherein the light is incident upon and selectively transmitted through a plurality of the filter elements prior to being received by the plurality of optical sensors;

wherein spectral characteristics of the light provided to the diffraction grating are measured;

wherein the filter elements/optical sensors are positioned to define a second optical path length from the diffraction grating, wherein the second optical path length is less than the first optical path length, wherein the spectral characteristics of the light provided to the diffraction grating are measured in accordance with the first predetermined spectral resolution with a reduced optical path length;

wherein the optical sensors comprise light to frequency converters.

18. The method of claim 17, wherein the optical sensors comprise an array of optical sensors.

19. The method of claim 17, wherein the optical sensors comprise a linear array of optical sensors.

20. The method of claim 17, wherein the optical sensors comprise CCD sensors, photodiode sensors or phototransistor sensors.

21. The method of claim 17, wherein the filter elements comprise interference filters.

22. The method of claim 17, wherein the light is collimated by an aspheric lens or lens assembly prior to being provided to the diffraction grating.

23. The method of claim 17, wherein the light is provided to the material or object by one or more light sources.

24. The method of claim 23, wherein characteristics of the material or object are determined.

25. The method of claim 24, wherein the characteristics comprise spectral characteristics.

26. The method of claim 24, wherein the characteristics comprise whether the material or object contains a predetermined material.

27. The method of claim 24, wherein a determination is made if the object or material is genuine.

28. The method of claim 24, wherein the material or object comprises a gaseous material, a non-gaseous material, skin, non-skin body tissue, paint, fabric, a photograph, a dental object, a printed object, hair, or makeup.

29. The method of claim 17, wherein the spectrometer device comprises a handheld spectrometer.

30. The method of claim 17, wherein the spectrometer device comprises a handheld spectrophotometer.

31. The method of claim 17, wherein the diffraction grating is substantially curved in shape.

32. A method for making spectral measurements with a reduced optical path length, diffraction grating-based, spectrometer device, comprising the steps of:

providing light to a diffraction grating, wherein the diffraction grating requires a first optical path length from the diffraction grating for a first predetermined spectral resolution of spectral measurement;

providing a plurality of filter elements and a plurality of optical sensors, wherein the plurality of filter elements are positioned in an optical path between the diffraction grating and the plurality of optical sensors;

receiving diffracted light from the diffraction grating with the plurality of optical sensors, wherein the light is incident upon and selectively transmitted through a plurality of the filter elements prior to being received by the plurality of optical sensors;

wherein spectral characteristics of the light provided to the diffraction grating are measured;

wherein the filter elements/optical sensors are positioned to define a second optical path length from the diffraction grating, wherein the second optical path length is less than the first optical path length, wherein the spectral characteristics of the light provided to the diffraction grating are measured in accordance with the first predetermined spectral resolution with a reduced optical path length;

wherein the filter elements comprise a linear variable filter.

33. The method of claim 32, wherein the optical sensors comprise an array of optical sensors.

34. The method of claim 32, wherein the optical sensors comprise a linear array of optical sensors.

35. The method of claim 32, wherein the optical sensors comprise CCD sensors, photodiode sensors or phototransistor sensors.

36. The method of claim 32, wherein the filter elements comprise interference filters.

37. The method of claim 32, wherein the light is collimated by an aspheric lens or lens assembly prior to being provided to the diffraction grating.

38. The method of claim 32, wherein the light is provided to the material or object by one or more light sources.

39. The method of claim 38, wherein characteristics of the material or object are determined.

40. The method of claim 39, wherein the characteristics comprise spectral characteristics.

41. The method of claim 39, wherein the characteristics comprise whether the material or object contains a predetermined material.

42. The method of claim 39, wherein a determination is made if the object or material is genuine.

43. The method of claim 39, wherein the material or object comprises a gaseous material, a non-gaseous material, skin, non-skin body tissue, paint, fabric, a photograph, a dental object, a printed object, hair, or makeup.

44. The method of claim 32, wherein the spectrometer device comprises a handheld spectrometer.

45. The method of claim 32, wherein the spectrometer device comprises a handheld spectrophotometer.

46. The method of claim 32, wherein the diffraction grating is substantially curved in shape.

47. A method for making spectral measurements with a reduced optical path length, diffraction grating-based, spectrometer device, comprising the steps of:

providing light to a diffraction grating, wherein the diffraction grating requires a first optical path length from the diffraction grating for a first predetermined spectral resolution of spectral measurement;

providing a plurality of filter elements and a plurality of optical sensors, wherein the plurality of filter elements are positioned in an optical path between the diffraction grating and the plurality of optical sensors;

receiving diffracted light from the diffraction grating with the plurality of optical sensors, wherein the light is incident upon and selectively transmitted through a plurality of the filter elements prior to being received by the plurality of optical sensors;

wherein spectral characteristics of the light provided to the diffraction grating are measured;

wherein the filter elements/optical sensors are positioned to define a second optical path length from the diffraction grating, wherein the second optical path length is less than the first optical path length, wherein the spectral characteristics of the light provided to the diffraction grating are measured in accordance with the first predetermined spectral resolution with a reduced optical path length;

wherein the filter elements comprise a color gradient filter.

48. The method of claim 47, wherein the optical sensors comprise an array of optical sensors.

49. The method of claim 47, wherein the optical sensors comprise a linear array of optical sensors.

50. The method of claim 47, wherein the optical sensors comprise CCD sensors, photodiode sensors or phototransistor sensors.

51. The method of claim 47, wherein the filter elements comprise interference filters.

52. The method of claim 47, wherein the light is collimated by an aspheric lens or lens assembly prior to being provided to diffraction grating.

53. The method of claim 47, wherein the light is provided to the material or object by one or more light sources.

54. The method of claim 53, wherein characteristics of the material or object are determined.

55. The method of claim 54, wherein the characteristics comprise spectral characteristics.

56. The method of claim 54, wherein the characteristics comprise whether the material or object contains a predetermined material.

57. The method of claim 54, wherein a determination is made if the object or material is genuine.

58. The method of claim 54, wherein the material or object comprises a gaseous material, a non-gaseous material, skin, non-skin body tissue, paint, fabric, a photograph, a dental object a printed object, hair, or makeup.

59. The method of claim 47, wherein the spectrometer device comprises a handheld spectrometer.

60. The method of claim 47, wherein the spectrometer device comprises a handheld spectrophotometer.

61. The method of claim 47, wherein the diffraction grating is substantially curved in shape.

62. A method for making spectral measurements with a reduced optical path length, diffraction grating-based, spectrometer device, comprising the steps of:

providing light to a diffraction grating, wherein the diffraction grating requires a first optical path length from the diffraction grating for a first predetermined spectral resolution of spectral measurement;

providing a plurality of filter elements and a plurality of optical sensors, wherein the plurality of filter elements are positioned in an optical path between the diffraction grating and the plurality of optical sensors;

receiving diffracted light from the diffraction grating with the plurality of optical sensors, wherein the light is incident upon and selectively transmitted through a plurality of the filter elements prior to being received by the plurality of optical sensors;

wherein spectral characteristics of the light provided to the diffraction grating are measured;

wherein the filter elements/optical sensors are positioned to define a second optical path length from the diffraction grating, wherein the second optical path length is less than the first optical path length, wherein the spectral characteristics of the light provided to the diffraction grating are measured in accordance with the first predetermined spectral resolution with a reduced optical path length;

wherein the filter elements comprise interference filters deposited on an optical manifold, wherein the diffraction grating is part of the optical manifold, wherein light exits the optical manifold through the interference filters and is detected by the optical sensors.

63. The method of claim 62, wherein the optical sensors comprise an array of optical sensors.

64. The method of claim 62, wherein the optical sensors comprise a linear array of optical sensors.

65. The method of claim 62, wherein the optical sensors comprise CCD sensors, photodiode sensors or phototransistor sensors.

66. The method of claim 62, wherein the filter elements comprise interference filters.

67. The method of claim 62, wherein the light is collimated by an aspheric lens or lens assembly prior to being provided to the diffraction grating.

68. The method of claim 62, wherein the light is provided to the material or object by one or more light sources.

69. The method of claim 68, wherein characteristics of the material or object are determined.

70. The method of claim 69, wherein the characteristics comprise spectral characteristics.

71. The method of claim 69, wherein the characteristics comprise whether the material or object contains a predetermined material.

72. The method of claim 69, wherein a determination is made if the object or material is genuine.

73. The method of claim 69, wherein the material or object comprises a gaseous material, a non-gaseous material, skin, non-skin body tissue, paint, fabric, a photograph, a dental object, a printed object, hair, or makeup.

74. The method of claim 62, wherein the spectrometer device comprises a handheld spectrometer.

75. The method of claim 62, wherein the spectrometer device comprises a handheld spectrophotometer.

76. The method of claim 62, wherein the diffraction grating is substantially curved in shape.

77. A method for making spectral measurements with a reduced optical path length, diffraction grating-based, spectrometer device, comprising the steps of:

providing light to a diffraction grating, wherein the diffraction grating requires a first optical path length from the diffraction grating for a first predetermined spectral resolution of spectral measurement;

providing a plurality of filter elements and a plurality of optical sensors, wherein the plurality of filter elements are positioned in an optical path between the diffraction grating and the plurality of optical sensors;

receiving diffracted light from the diffraction grating with the plurality of optical sensors, wherein the light is incident upon and selectively transmitted through a plurality of the filter elements prior to being received by the plurality of optical sensors;

wherein spectral characteristics of the light provided to the diffraction grating are measured;

wherein the filter elements/optical sensors are positioned to define a second optical path length from the diffraction grating, wherein the second optical path length is less than the first optical path length, wherein the spectral characteristics of the light provided to the diffraction grating are measured in accordance with the first predetermined spectral resolution with a reduced optical path length;

wherein the light is collimated prior to being provided to the diffraction grating.

78. The method of claim 77, wherein the light is collimated by an aspheric lens or lens assembly.

79. The method of claim 77, wherein the optical sensors comprise an array of optical sensors.

80. The method of claim 77, wherein the optical sensors comprise a linear array of optical sensors.

81. The method of claim 77, wherein the optical sensors comprise CCD sensors, photodiode sensors or phototransistor sensors.

82. The method of claim 77, wherein the filter elements comprise interference filters.

83. The method of claim 77, wherein the light is provided to the material or object by one or more light sources.

84. The method of claim 83, wherein characteristics of the material or object are determined.

85. The method of claim 84, wherein the characteristics comprise spectral characteristics.

86. The method of claim 84, wherein the characteristics comprise whether the material or object contains a predetermined material.

87. The method of claim 84, wherein a determination is made if the object or material is genuine.

88. The method of claim 84, wherein the material or object comprises a gaseous material, a non-gaseous material, skin, non-skin body tissue, paint, fabric, a photograph, a dental object, a printed object, hair, or makeup.

89. The method of claim 77, wherein the spectrometer device comprises a handheld spectrometer.

90. The method of claim 77, wherein the spectrometer device comprises a handheld spectrophotometer.

91. The method of claim 77, wherein the diffraction grating is substantially curved in shape.