Apparatus and method for measuring optical characteristics of an object

• US 7,397,562 B2
• Filed: 06/26/2006
• Issued: 07/08/2008
• Est. Priority Date: 07/09/1998
• Status: Expired due to Fees

• Current Assignee: RPX Corporation
• Original Assignee: JJL Technologies, L.L.C.
• Inventors: Jung, Wayne D, Jung, Russell W, Loudermilk, Alan R.
• Primary Examiner(s): Nguyen, Tu T
• Application Number:
  US11/475,717
• Publication Number:
  US 20070061111A1
• Time in Patent Office: 743 Days
• Field of Search: None
• US Class Current: 356/419
• CPC Class Codes: G01J 1/0411 using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
• CPC Class Codes: G01J 1/0437 using masks, aperture plates, spatial light modulators, spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 1/0474 Diffusers cavities G01J2001/0481
• CPC Class Codes: G01J 1/06 Restricting the angle of incident light
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02
• 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 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• 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 3/0227 using notch filters
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/0251 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 3/027 Control of working procedures of a spectrometer; Failure detection; Bandwidth calculation
• CPC Class Codes: G01J 3/0275 making use of sensor-related data, e.g. for identification of sensor parts or optical elements
• 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 3/10 : Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/2803 : using photoelectric array detector
• CPC Class Codes: G01J 3/46 : Measurement of colour; Colour measuring devices, e.g. colorimeters measuring colour temperature G01J5/60
• CPC Class Codes: G01J 3/463 : 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

Abstract

A method for determining spectral characteristics of an object is disclosed. A probe is positioned in proximity relative to the object and provides light to a surface of the object and receives light from the object. One or more critical heights are defined below which no specularly refelcted light is received and propagated. Prior to positioning the probe in proximity relative to the object, a plurality of position-sensitive calibration/normalization reference and a plurality of calibration/normalization measurements are taken with the probe at a plurality of predetermined positions with respect to the calibration/normalization reference. The intensity of light received is determined in a plurality of spectral bands with one or more measurements. The spectral characteristics of the object are determined based on the one or more measurements and based on data taken from one or more of the calibration/normalization measurements.

Claims

1. A method for determining spectral characteristics of an object comprising the steps of:

positioning a probe and/or the object such that the probe is in proximity relative to the object, wherein the probe provides light to a surface of the object and receives light from the object, wherein light is provided from the probe by at least first and second light sources and light is received by at least a central light receiver, wherein the first light source is positioned a first distance from the central light receiver and the second light source is positioned a second distance from the central light receiver, and wherein the first light source and the central light receiver define a first critical height from the surface below which no specularly reflected light from the first light source is received and propagated by the central light receiver and the second light source and the central light receiver define a second critical height from the surface below which no specularly reflected light from the second light source is received and propagated by the central light receiver, wherein the first critical height is different from the second critical height;

prior to positioning the probe and/or the object such that the probe is in proximity relative to the object, taking a plurality of position-sensitive calibration/normalization measurements, wherein the probe is controllably moved relative to a calibration/normalization reference, wherein a plurality of calibration/normalization measurements are taken with the probe at a plurality of predetermined positions with respect to the calibration/normalization reference;

when the probe is positioned in proximity relative to the object determining the intensity of light received by the central light receiver in a plurality of spectral bands with a first measurement when the first light source is on and with a second measurement when the second light source is on;

determining the spectral characteristics of the object based on the first and second measurements and based on data taken from one or more of the calibration/normalization measurements.

2. The method of claim 1, wherein the controllable movement of the probe relative to the calibration/normalization reference is controlled by a servo motor.

3. The method of claim 1, wherein one or more position sensors detect the position of the probe relative to the plurality of predetermined positions.

4. The method of claim 1, wherein a computer remote from the probe controls the taking of the plurality of calibration/normalization measurements.

5. The method of claim 4, wherein the computer receives data from the plurality of calibration/normalization measurements via the internet.

6. The method of claim 5, wherein the computer receives data from a plurality of probes in a plurality of geographically remote locations.

7. A method for determining spectral characteristics of an object comprising the steps of:

positioning a probe and/or the object such that the probe is in proximity relative to the object, wherein the probe provides light to a surface of the object via one or more light sources and receives light from the object via one or more light receivers, wherein the one or more light sources and the one or more light receivers define a plurality of light source/light receiver pairs, wherein a first light source/light receiver pair defines a first critical height from the surface below which no specularly reflected light from the light source of the first light source/light receiver pair is received and propagated by the light receiver of the first light source/light receiver pair, and a second light source/light receiver pair defines a second critical height from the surface below which no specularly reflected light from the light source of the second light source/light receiver pair is received and propagated by the light receiver of the second light source/light receiver pair, wherein the first critical height is different from the second critical height;

prior to positioning the probe and/or the object such that the probe is in proximity relative to the object, taking a plurality of position-sensitive calibration/normalization measurements, wherein the probe is controllably moved relative to a calibration/normalization reference, wherein a plurality of calibration/normalization measurements are taken with the probe at a plurality of predetermined positions with respect to the calibration/normalization reference;

when the probe is positioned in proximity relative to the object determining the intensity of light received by the one or more light receivers in a plurality of spectral bands with one or more measurements;

determining the spectral characteristics of the object based on the one or more measurements and based on data taken from one or more of the calibration/normalization measurements.

8. The method of claim 7, wherein the controllable movement of the probe relative to the calibration/normalization reference is controlled by a servo motor.

9. The method of claim 7, wherein one or more position sensors detect the position of the probe relative to the plurality of predetermined positions.

10. The method of claim 7, wherein a computer remote from the probe controls the taking of the plurality of calibration/normalization measurements.

11. The method of claim 10, wherein the computer receives data from the plurality of calibration/normalization measurements via the internet.

12. The method of claim 11, wherein the computer receives data from a plurality of probes in a plurality of geographically remote locations.

13. A method for determining spectral characteristics of an object comprising the steps of:

positioning a probe and/or the object such that the probe is in proximity relative to the object, wherein the probe provides light to a surface of the object via at least a first light source and receives light from the object via at least a first light receiver, wherein the first light source and the first light receiver define a first critical height from the surface below which no specularly reflected light from the first light source is received and propagated by the first light receiver;

prior to positioning the probe and/or the object such that the probe is in proximity relative to the object, taking a plurality of position-sensitive calibration/normalization measurements, wherein the probe is controllably moved relative to a calibration/normalization reference, wherein a plurality of calibration/normalization measurements are taken with the probe at a plurality of predetermined positions with respect to the calibration/normalization reference;

when the probe is positioned in proximity relative to the object determining the intensity of light received by the first light receiver in a plurality of spectral bands with one or more measurements;

determining the spectral characteristics of the object based on the one or more measurements and based on data taken from one or more of the calibration/normalization measurements.

14. The method of claim 13, wherein the controllable movement of the probe relative to the calibration/normalization reference is controlled by a servo motor.

15. The method of claim 13, wherein one or more position sensors detect the position of the probe relative to the plurality of predetermined positions.

16. The method of claim 13, wherein a computer remote from the probe controls the taking of the plurality of calibration/normalization measurements.

17. The method of claim 16, wherein the computer receives data from the plurality of calibration/normalization measurements via the internet.

18. The method of claim 17, wherein the computer receives data from a plurality of probes in a plurality of geographically remote locations.