Integrated spectrometer assembly and methods

• US 6,246,479 B1
• Filed: 12/23/1999
• Issued: 06/12/2001
• Est. Priority Date: 06/08/1998
• Status: Expired due to Term

• 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:
  US09/471,953
• Time in Patent Office: 537 Days
• Field of Search: 356/414, 356/416, 356/419, 356/71, 250/226, 359/891, 359/892, 257/432, 257/434, 257/435, 257/436, 257/440, 257/443, 257/444
• US Class Current: 356/419
• 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 2021/6471 Special filters, filter wheel
• 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. Low cost and small form factor spectrometers, and methods for manufacturing the same, also are disclosed.

Claims

1. A spectrometer assembly, comprising:

a substrate having thereon a plurality of optical sensors and one or more processing elements;

a plurality of filter elements fixedly positioned over at least a first group of the sensors and fixedly positioned with respect to the substrate, wherein the plurality of filter elements have spectral transmission characteristics over one or more predetermined spectral bands;

an optical manifold fixedly positioned over at least certain of the plurality of filter elements and fixedly positioned with respect to the substrate, wherein the optical manifold has a plurality of exit ports and at least one entrance port, wherein light entering the entrance port is transmitted to an interior portion of the optical manifold, wherein at least a portion of the light is transmitted from the exit ports through at least certain of the filter elements and is sensed by at least certain of the sensors;

wherein light may be coupled to the entrance port, wherein at least first spectral data corresponding to the light is generated by the one or more processing elements, wherein the spectrometer assembly is fabricated in a fixed manner with respect to the substrate.

2. The assembly of claim 1, wherein the sensors comprise sensors that generate at least one signal having a frequency proportional to the light intensity received by the one or more sensors.

3. The assembly of claim 2, wherein the at least one signal comprises a digital signal.

4. The assembly of claim 3, wherein the digital signal comprises a TTL or CMOS digital signal.

5. The assembly of claim 2, wherein one or more spectral characteristics are determined based on measuring a period of a plurality of digital signals produced by a plurality of sensors.

6. The assembly of claim 2, wherein the signal comprises an asynchronous signal of a frequency dependent upon the intensity of the received light.

7. The assembly of claim 2, wherein the one or more sensors comprise a plurality of light to frequency converter sensing elements.

8. The assembly of claim 1, wherein the filter elements comprise a plurality of filter portions having a wavelength dependent optical transmission property.

9. The assembly of claim 1, wherein a spectral analysis is performed based on light received from an object or material.

10. The assembly of claim 1, wherein the filter elements comprise a plurality of cut-off filter elements.

11. The assembly of claim 1, wherein the filter elements collectively comprise a color gradient filter.

12. The assembly of claim 1, wherein the filter elements collectively comprise a filter grid.

13. The assembly of claim 1, wherein received light is spectrally analyzed without using a diffraction grating.

14. The assembly of claim 1, wherein the light is received by a probe, wherein a plurality of measurements are taken at a plurality of distances of the probe with respect to the object or material.

15. The assembly of claim 1, wherein a probe having one or more light sources provides light to an object or material, wherein light from one or more light sources is received by one or more light receivers from the object or material.

16. The assembly of claim 15, wherein one or more sensors determine a distance of the probe with respect to the object or material.

17. The assembly of claim 15, wherein one or more sensors determine an angle of the probe with respect to the object or material.

18. The assembly of claim 15, wherein one or more sensors determine a distance and an angle of the probe with respect to the object or material.

19. The assembly of claim 1, wherein the at least one signal having a frequency proportional to the light intensity received by the one or more sensors is generated by an integrator coupled to the one or more sensors.

20. The assembly of claim 1, wherein the sensors comprise a photo diode array.

21. The assembly of claim 1, wherein the filter elements comprise one or more interference filters.

22. The assembly of claim 1, wherein the light is collimated prior to being sensed by the sensors.

23. The assembly of claim 22, wherein the light is collimated by an aspheric lens or lens assembly.

24. The assembly of claim 1, wherein the light is provided by one or more light sources to an object or material.

25. The assembly of claim 24, wherein characteristics of the object or material are determined.

26. The assembly of claim 25, wherein the characteristics comprise spectral characteristics.

27. The assembly of claim 25, wherein the characteristics comprise whether the object or material contains a predetermined material.

28. The assembly of claim 25, wherein a determination is made if the object or material is genuine.

29. The assembly of claim 24, wherein the object or material 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.

30. The assembly of claim 1, further comprising a bias light source, wherein the bias light source provides bias light to at least certain of the sensors.

31. The assembly of claim 1, further comprising a probe providing light to a surface of an object or material and receiving light from the object or material, wherein light is provided from the probe by at least one light source and light is received by one or more light receivers, wherein the light source and one or more of the light receivers define a critical height from the surface below which no light from the light source that is specularly reflected from the object or material is received by the one or more of the light receivers.

32. The assembly of claim 31, wherein the assembly takes at least one measurement with the probe below the critical height for one or more of the light receivers.

33. The assembly of claim 1, further comprising a blocking filter, wherein the blocking filter blocks light outside of a spectral resolution range of the assembly.

34. The assembly of claim 1, wherein the exit ports are of non-uniform size.

35. The assembly of claim 34, wherein a first exit port corresponding to a sensor receiving light from a filter element that passes light from a blue portion of a spectrum of light received by the assembly has a size greater than a second exit port corresponding to a sensor receiving light from a filter element that passes light from a red portion of the spectrum of light received by the assembly.

36. The assembly of claim 1, further comprising a non-coherent light guide, wherein light from the non-coherent light guide is coupled to the at least one entrance port.

37. The assembly of claim 1, wherein the optical manifold comprises an optical block.

38. The assembly of claim 37, wherein the optical block comprises quartz or a poly-optic material.

39. The assembly of claim 37, wherein the optical block has mirrored surfaces.

40. The assembly of claim 37, wherein the optical block includes a surface that includes the plurality of exit ports.

41. The assembly of claim 40, wherein the surface of the optical block that includes the plurality of exit ports is contoured.

42. The assembly of claim 41, wherein the contoured surface of the optical block provides lens for at least certain of the plurality of exit ports.

43. The assembly of claim 40, wherein an optical mask is adjacent the surface that includes the plurality of exit ports.

44. The assembly of claim 43, wherein the optical mask controls angles of light that is received by the sensors.

45. The assembly of claim 1, wherein the filter elements comprise interference filters deposited on the optical manifold.

46. The assembly of claim 45, wherein light exits the optical manifold rough the interference filters and is detected by the sensors.