Apparatus and method for measuring optical characteristics of an object

• US 6,246,471 B1
• Filed: 01/10/2000
• Issued: 06/12/2001
• Est. Priority Date: 06/08/1998
• Status: Expired due to Term

• Current Assignee: JJL Technologies, L.L.C., 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:
  US09/480,312
• Time in Patent Office: 519 Days
• Field of Search: 356/326, 356/328, 356/71, 356/73
• US Class Current: 356/73
• 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 3/0251 Colorimeters making use of an integrating sphere
• CPC Class Codes: G01J 3/0259 Monolithic
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/50 using electric radiation detectors
• 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 2021/4742 comprising optical fibres
• CPC Class Codes: G01N 2021/4747 Concentric bundles
• CPC Class Codes: G01N 2021/6484 Optical fibres
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/474 Details of optical heads therefor, e.g. using optical fibres
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence

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 data base. 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 comprising the steps of:

providing light to a diffraction grating;

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

wherein spectral characteristics of the light are determined.

2. The 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 filter elements comprise interference filters.

5. The method of claim 1, wherein the filter elements comprise a linear variable filter.

6. The method of claim 1, wherein the filter elements comprise a color gradient filter.

7. The method of claim 1, 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.

8. The method of claim 1, wherein the diffraction grating is curved.

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

10. The method of claim 1, wherein the light is collimated prior to being provided to the diffraction grating.

11. The method of claim 10, wherein the light is collimated by an aspheric lens or lens assembly.

12. The method of claim 1, further comprising the step of providing light to a material or object, wherein the light provided to the diffraction grating comprises light received from the material or object.

13. The method of claim 12, wherein characteristics of the material or object are determined.

14. The method of claim 13, wherein the characteristics comprise spectral characteristics.

15. The method of claim 13, wherein the characteristics comprise whether the material or object contains a predetermined material.

16. The method of claim 13, wherein a determination is made if the object or material is genuine.

17. The method of claim 12, wherein the light is provided to the material or object by a probe, 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.

18. The method of claim 12, 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.

19. A method comprising the steps of:

providing light to a material or object;

providing light to a diffraction grating, wherein the light provided to the diffraction grating comprises light received from the material or object;

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

wherein spectral characteristics of the light are measured;

wherein the light is provided to the material or object by a probe, 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.

20. The method of claim 19, wherein the optical sensors comprise an array of optical sensors.

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

22. The method of claim 19, wherein the optical sensors comprise CCD sensors, photodiode sensors or phototransistor sensors.

23. The method of claim 19, wherein the optical sensors comprise light to frequency converters.

24. The method of claim 19, wherein the filter elements comprise interference filters.

25. The method of claim 19, wherein the filter elements comprise a linear variable filter.

26. The method of claim 19, wherein the filter elements comprise a color gradient filter.

27. The method of claim 19, 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.

28. The method of claim 19, wherein the diffraction grating is curved.

29. The method of claim 19, wherein the diffraction grating comprises a spherical diffraction grating.

30. The method of claim 19, wherein the light is collimated prior to being provided to the diffraction grating.

31. The method of claim 30, wherein the light is collimated by an aspheric lens or lens assembly.

32. The method of claim 19, wherein the light is provided by one or more light sources.

33. The method of claim 32, wherein characteristics of the material or object are determined.

34. The method of claim 33, wherein the characteristics comprise spectral characteristics.

35. The method of claim 33, wherein the characteristics comprise whether the material or object contains a predetermined material.

36. The method of claim 33, wherein a determination is made if the object or material is genuine.

37. The method of claim 32, wherein the second optical sensors comprise light to frequency converters.

38. The method of claim 32, 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.

39. A method comprising the steps of:

providing light to a diffraction grating;

receiving diffracted light from the diffraction grating with a plurality of optical sensors, wherein the optical sensors comprise light to frequency converters;

wherein spectral characteristics of the light are determined.

40. The method of claim 39, wherein the optical sensors comprise an array of optical sensors.

41. The method of claim 39, wherein the optical sensors comprise a linear array of optical sensors.

42. The method of claim 39, wherein the optical sensors comprise CCD sensors, photodiode sensors or phototransistor sensors.

43. The method of claim 39, wherein the optical sensors comprise an array of light to frequency converters.

44. The method of claim 39, wherein light is selectively coupled to the optical sensors through a plurality of filter elements, wherein the filter elements comprise interference filters.

45. The method of claim 39, wherein light is selectively coupled to the optical sensors through a plurality of filter elements, wherein the filter elements comprise a linear variable filter.

46. The method of claim 39, wherein light is selectively coupled to the optical sensors through a plurality of filter elements, wherein the filter elements comprise a color gradient filter.

47. The method of claim 39, wherein light is selectively coupled to the optical sensors through a plurality of filter elements, 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.

48. The method of claim 39, wherein the diffraction grating is curved.

49. The method of claim 39, wherein the diffraction grating comprises a spherical diffraction grating.

50. The method of claim 39, wherein the light is collimated prior to being provided to the diffraction grating.

51. The method of claim 50, wherein the light is collimated by an aspheric lens or lens assembly.

52. The method of claim 39, further comprising the step of providing light to a material or object, wherein the light provided to the diffraction grating comprises light received from the material or object.

53. The method of claim 52, wherein characteristics of the material or object are determined.

54. The method of claim 53, wherein the characteristics comprise spectral characteristics.

55. The method of claim 53, wherein the characteristics comprise whether the material or object contains a predetermined material.

56. The method of claim 52, wherein a determination is made if the object or material is genuine.

57. The method of claim 52, wherein the light is provided to the material or object by a probe, 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.

58. The method of claim 52, 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.