System and method for calibrating optical characteristics

• US 7,907,281 B2
• Filed: 07/26/2010
• Issued: 03/15/2011
• Est. Priority Date: 02/21/2002
• Status: Active Grant

• Current Assignee: Vita Zahnfabrik H. Rauter GMBH & Co.. KG (Rauter Beteiligungsgesellschaft mbH)
• Original Assignee: Vita Zahnfabrik H. Rauter GMBH & Co.. KG (Rauter Beteiligungsgesellschaft mbH)
• Inventors: Sloan, Walter W., Jung, Russell W., Loudermilk, Alan R., Jung, Wayne D.
• Primary Examiner(s): LAUCHMAN, LAYLA G
• Application Number:
  US12/843,637
• Publication Number:
  US 20100291510A1
• Time in Patent Office: 232 Days
• Field of Search: 356/402, 356/405, 356/73
• US Class Current: 356/402
• CPC Class Codes: A61C 19/04 Measuring instruments specially adapted for dentistry A61C5/44 takes precedence; testing vitality of teeth A61B5/0534; radiation diagnosis specially adapted for dentistry A61B6/51
• CPC Class Codes: G01J 1/0271 Housings; Attachments or accessories for photometers
• CPC Class Codes: G01J 2003/466 Coded colour; Recognition of predetermined colour; Determining proximity to predetermined colour
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/0256 Compact construction
• 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 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/0294 Multi-channel spectroscopy
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 3/46 Measurement of colour; Colour measuring devices, e.g. colorimeters measuring colour temperature G01J5/60
• CPC Class Codes: G01J 3/462 Computing operations in or between colour spaces; Colour management systems
• CPC Class Codes: G01J 3/463 Colour matching
• 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: G01J 3/524 Calibration of colorimeters
• CPC Class Codes: G01N 21/25 Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
• CPC Class Codes: G01N 21/57 : Measuring gloss

Abstract

A miniaturized spectrometer/spectrophotometer system and methods are disclosed. A probe tip including one or more light sources and a plurality of light receivers is provided. A first spectrometer system receives light from a first set of the plurality of light receivers. A second spectrometer system receives light from a second set of the plurality of light receivers. A processor, wherein the processor receives data generated by the first spectrometer system and the second spectrometer system, wherein an optical measurement of a sample under test is produced based on the data generated by the first and second spectrometer systems.

Claims

1. A method for determining optical characteristics of an object comprising:

storing a plurality of optical property parameters for each of a plurality of shades;

calibrating the stored plurality of optical property parameters by measuring optical properties of a test object;

replacing the stored plurality of optical property parameters with the calibrated plurality of optical property parameters;

measuring optical properties of the object with an instrument;

comparing the measured optical properties of the object to the stored calibrated optical property parameters;

determining one or more shade match candidates according to the comparing; and

displaying the one or more shade match candidates on a display device.

2. The method of claim 1, wherein the object is a denture tooth.

3. The method of claim 1, wherein the object is a tooth.

4. The method of claim 1, wherein the object is a restoration.

5. The method of claim 1, further comprising applying a barrier to the instrument, wherein the measuring optical properties of a test object is performed by the instrument with the applied barrier.

6. The method of claim 1, wherein the test object is a translucent or semi-transparent material and has optical properties that are substantially in a middle portion of a range of optical properties of the object to be measured.

7. The method of claim 1, further comprising displaying an indication of which of the displayed one or more shade match candidates is a best match.

8. The method of claim 1, wherein the optical property parameters comprise one or more of the group consisting of color tristimulus values, tristimulus values of L, a and b, an integral intensity of a calculated spectrum, three values representing color information for the object and an integral intensity of a calculated spectrum, and three values representing color information for the object and a degree of curvature of a calculated spectrum.

9. The method of claim 1, further comprising capturing an image of the object and displaying additional color information according to measuring optical properties of the object superimposed on the captured image of the object.

10. The method of claim 1, wherein each of the plurality of optical property parameters includes a preferred value, and wherein comparing the measured optical property parameters further comprises summing differences between the measured plurality of optical property parameters and the preferred values for the stored plurality of optical property parameters.

11. The method of claim 1, wherein the measuring is performed in a plurality of regions of the object, and wherein the one or more shade match candidates are determined for each of the plurality of regions of the object.

12. The method of claim 1, further comprising displaying additional color information according to measuring optical properties of the object.

13. The method of claim 12, wherein the displayed information includes a difference in value of the optical property parameters for the one or more shade match candidates and the stored optical property parameters for each of the plurality of shades.

14. The method of claim 12, wherein the displayed information includes differences in value and chroma of the optical property parameters for the one or more shade match candidates and the stored optical property parameters for each of the plurality of shades.

15. The method of claim 12, wherein the displayed information includes differences in value, chroma and hue of the optical property parameters for the one or more shade match candidates and the stored optical property parameters for each of the plurality of shades.

16. A system for determining optical characteristics of an object comprising:

a memory for storing a plurality of optical property parameters for each of a plurality of shades, and for storing a plurality of weight factors for each of the stored plurality of optical property parameters, wherein each of the stored plurality of optical property parameters is associated with a weight factor depending on a material type of said object;

a calibration block for calibrating the stored plurality of optical property parameters by determining optical properties of a test object and replacing the stored plurality of optical property parameters with the calibrated plurality of optical property parameters in the memory;

an optical measurement unit for measuring optical properties of the object and the test object;

a processor for comparing the measured optical properties of the object to the stored calibrated optical property parameters for each shade, and for determining one or more shade match candidates according to the comparing; and

a display for displaying the one or more shade match candidates.

17. The system of claim 16, wherein the display further displays an indication of which of the displayed one or more shade match candidates is a best match.

18. The system of claim 16, wherein the object is a denture tooth, a tooth, or a restoration.

19. The system of claim 16, further comprising a barrier applied to the instrument, wherein the instrument with the applied barrier measures the optical properties of the test object.

20. The system of claim 16, wherein the test object is a translucent or semi-transparent material and has optical properties that are substantially in a middle portion of a range of optical properties of the object to be measured.