Self-targeting reader system for remote identification

• US 6,064,476 A
• Filed: 11/23/1998
• Issued: 05/16/2000
• Est. Priority Date: 11/23/1998
• Status: Expired due to Term

• Current Assignee: Spectra Science Corp. (Spectra Acquisition Corp.)
• Original Assignee: Spectra Science Corp. (Spectra Acquisition Corp.)
• Inventors: Goltsos, William
• Primary Examiner(s): Font, Frank G.
• Assistant Examiner(s): Nguyen, Tu T.
• Application Number:
  US09/197,650
• Time in Patent Office: 540 Days
• Field of Search: 356/417, 356/317, 356/375, 356/376, 250/458.1, 250/459.1, 250/461.1, 250/461.2, 250/548, 209/3.3, 209/579, 209/583
• US Class Current: 356/213
• CPC Class Codes: B07C 5/3412 according to a code applied to the object which indicates a property of the object, e.g. quality class, contents or incorrect indication sorting according to size measured by light-responsive means B07C5/10; sorting according to optical properties B07C5/342; for packages B65D79/02; for information carriers G06K7/00
• CPC Class Codes: B07C 5/342 according to optical properties, e.g. colour according to radiation transmittivity B07C5/3416

Abstract

A method and apparatus for identifying articles is disclosed. The method includes steps of: (a) providing a plurality of articles, each of the articles having at least one portion that includes a photonically active material; (b) for each article, illuminating the at least one portion with light from a stimulus source; (c) identifying a location of the at least one portion by detecting an emission from the photonically active material; (d) pointing an excitation source at the identified location; and (e) illuminating the at least one portion within the identified location with light from the excitation source. A next step detects an information-encoded emission from the photonically active material in response to the light from the excitation source. An optional step (g) sorts the articles based on the detected emission.

Claims

1. A method for identifying articles, comprising steps of:

providing a plurality of articles, each of the articles having at least one portion that includes a photonically active material;

for each article, illuminating the at least one portion with light from a stimulus source;

identifying a location of the at least one portion that includes the photonically active material by detecting an emission from the photonically active material;

pointing an excitation source at the identified location;

illuminating the at least one portion within the identified location with light from the excitation source; and

detecting an identification-encoded emission from the photonically active material in response to the light from the excitation source.

2. A method as set forth in claim 1, wherein the photonically active material is comprised of threads comprising a substrate material and an electromagnetic radiation emitting and amplifying material for providing a laser-like emission.

3. A method as set forth in claim 2, wherein the threads are stitched to the article.

4. A method as set forth in claim 2, wherein a patch is comprised of the threads, and wherein the patch is affixed to the article.

5. A method as set forth in claim 1, wherein the photonically active material is comprised of bead structures for providing an emission having characteristics similar to laser emission characteristics.

6. A method as set forth in claim 1, wherein the stimulus source is comprised of an electromagnetic source whose emission is absorbed by the photonically active material and which has sufficient energy to induce a detectable emission from the photonically active material.

7. A method as set forth in claim 1, wherein when excited by the light from the excitation source the photonically active material outputs a secondary emission that is substantially brighter than when excited by light from the stimulus source, such that a high signal-to-noise ratio spectral analysis of the identification-encoded emission is achieved.

8. A method as set forth in claim 1, and further comprising a step of sorting articles based on the detected identification-encoded emission.

9. A method as set forth in claim 1, wherein the detected identification-encoded emission is comprised of an optical code for identifying at least one characteristic of the article.

10. A method for identifying articles, comprising steps of:

providing a plurality of articles, each of the

articles having at least one portion that includes a photonically active material;

for each article, illuminating the at least one portion with light from a stimulus source;

identifying a location of the at least one portion by detecting an emission from the photonically active material;

pointing an excitation source at the identified location;

illuminating the at least one portion within the identified location with light from the excitation source; and

detecting an identification-encoded emission from the photonically active material in response to the light from the excitation source, wherein the method further comprises initial calibration steps of;

providing a calibration source for generating light;

co-propagating a portion of the light from the calibration source with a portion of the light from the excitation source and the response from the photonically active material to the light from the excitation source; and

constructing a calibration table for associating excitation source pointing directions with directions from which an emission is received in response to the light from the stimulus source.

11. A method for identifying articles, comprising steps of:

providing a plurality of self-emissive articles, each of the self-emissive articles having at least one portion that includes a photonically active material;

for each article, identifying a location of the at least one portion that includes the photonically active material by detecting an emission from the self-emissive article;

pointing an excitation source at the identified location;

illuminating the at least one portion within the identified location with light from the excitation source;

detecting an identification-encoded emission from the photonically active material in response to the light from the excitation source; and

identifying an individual one of the articles based on the detected identification-encoded emission.

12. A method as set forth in claim 11, wherein the self-emissive articles are comprised of one of bioluminescent and chemiluminescent articles.

13. An apparatus for identifying articles, comprising:

a stimulus source generating light for illuminating at least one portion of each of said articles, said at least one portion comprising a photonically active material;

a first detector for identifying a location of said at least one portion that comprises said photonically active material by detecting an emission from said photonically active material in response to said light from said stimulus source;

an excitation source for generating light;

a pointing system for pointing said excitation source at said identified location such that said light from said excitation source illuminates said at least one portion within said identified location; and

a second detector for detecting an information-encoded emission from said photonically active material in response to said light from the excitation source.

14. An apparatus as set forth in claim 13, wherein said stimulus source is comprised of a radiant source whose emission is absorbed by said photonically active material and which has sufficient energy to induce a detectable secondary emission from said photonically active material.

15. An apparatus as set forth in claim 13, wherein said first detector is comprised of an electronic camera.

16. An apparatus as set forth in claim 13, wherein said excitation source is comprised of a laser.

17. An apparatus as set forth in claim 13, wherein said excitation source is comprised of one of a flashlamp-pumped, Q-switched frequency doubled Nd:

YAG laser, a diode-pumped, Q-switched frequency doubled Nd;

YAG laser, and devices derived from nonlinear devices which include Nd;

YAG lasers and other laser crystals.

18. An apparatus as set forth in claim 13, wherein said means for pointing is comprised of a beamsteering device having at least one degree of freedom.

19. An apparatus as set forth in claim 13, and further comprising a conveyor for moving said articles through a field of view of said apparatus.

20. An apparatus as set forth in claim 13, and further comprising a calibration subsystem for associating an output of said first detector with a controlling input of said pointing system.

21. A method for determining information about an object, comprising steps of:

providing an object so as to have at least one portion comprised of a photonically active material;

illuminating the at least one portion with stimulus light;

detecting a first emission from the photonically active material in response to the stimulus light;

identifying a location of the at least one portion using the detected first emission;

pointing a beam of excitation light at the identified location;

illuminating the at least one portion within the identified location with the excitation light;

detecting a second emission from the photonically active material in response to the excitation light; and

decoding the second emission to obtain information that is descriptive of at least one characteristic of the object.

22. A method as in claim 21, wherein the steps of illuminating use two separate light sources.

23. A method as in claim 22, wherein one of the light sources is comprised of a lamp, and wherein another one of the sources is comprised of a laser.

24. A method as in claim 22, wherein both of the light sources are comprised of a lamp.

25. A method as in claim 22, wherein both of the light sources are comprised of a laser.

26. A method as in claim 21, wherein the steps of illuminating use the same light source.

27. A method as in claim 26, wherein the light source is comprised of a lamp.

28. A method as in claim 26, wherein the light source is comprised of a laser.

29. A method as in claim 21, wherein the step of illuminating the at least one portion with stimulus light comprises a step of operating one of an X-ray source, a flashlamp, a fluorescent lamp, an incandescent lamp or a laser.

30. A method as in claim 21, wherein the step of illuminating the at least one portion within the identified location with excitation light comprises a step of operating a Xenon flashlamp.

31. A method as in claim 21, wherein the step of illuminating the at least one portion within the identified location with excitation light comprises a step of generating a plurality of wavelengths of light.

32. A method as in claim 31, wherein the step of generating includes steps of generating first excitation light having a first wavelength;

and generating further excitation light, having a second wavelength, from the first excitation light.

33. A method as in claim 21, wherein the step of detecting the first emission uses an imager having a two-dimensional field of view;

and wherein the step of pointing the beam of excitation light uses a pointing system that operates in two-dimensions.

34. A method as in claim 21, wherein the step of providing the object includes a step of moving the object, wherein the step of pointing the beam of excitation light points the beam along one axis.

35. A method as in claim 21, wherein the step of detecting the first emission uses one of a position sensing detector or an imaging camera system.

36. A method as in claim 21, and further comprising a step of reducing parallax between a field of view of a source of the stimulus light and a field of view of a source of the excitation light.

37. A method as in claim 36, wherein the step of reducing parallax includes steps of generating a calibration table that relates an output of a system that detects the first emission to a system that points the beam of excitation light;

and using the calibration table when pointing the beam of excitation light based on the output of the system that detects the first emission.

38. A method as in claim 21, wherein the step of detecting the second emission comprises steps of spectrally imaging emissions along one axis and spatially imaging emissions along a second axis.

39. A method as in claim 38, wherein the step of decoding comprises a step of analyzing both of the spectrally imaged emissions and the spatially imaged emissions to obtain the information that is descriptive of the at least one characteristic of the object.

40. A method as in claim 21, wherein the step of detecting the first emission uses an emission detector having a field of view;

and wherein the field of view of the emission detector is separate from a field of view of a pointing system that points the beam of excitation light.

41. A method as in claim 21, wherein the step of detecting the first emission uses an emission detector having a field of view;

and wherein the field of view of the emission detector directed through a pointing system that points the beam of excitation light.

42. A method as in claim 21, wherein the step of detecting the second emission comprises a further step of detecting at least one property of the object.

43. A method as in claim 42, wherein the at least one property is comprised of color.

44. A method as in claim 21, wherein the step of illuminating the at least one portion with stimulus light comprises a step of generating a plurality of wavelengths of light.

45. A method for determining information about an object, comprising steps of:

providing an object so as to have a plurality of regions each comprised of a photonically active material;

illuminating at least a portion of the object with stimulus light;

detecting a first emission from the photonically active material in response to the stimulus light;

identifying a location of each of the plurality of regions from the detected first emission;

pointing a beam of excitation light, in turn, at each of the identified locations for illuminating, in turn, each of the regions with the excitation light;

in response to the excitation light, detecting a second emission from the photonically active material in each of the illuminated regions; and

decoding a plurality of the second emissions to obtain information that is descriptive of at least one characteristic of the object.

46. A method for identifying individual ones of a plurality of objects, comprising steps of:

providing each of the plurality of objects so as to have at least one region comprised of a photonically active material;

illuminating the plurality of objects with stimulus light;

detecting from each object a first emission from the photonically active material in response to the stimulus light;

identifying a location of each of the plurality of regions from the detected first emission;

pointing a beam of excitation light, in turn, at each of the identified locations for illuminating, in turn, each of the regions with the excitation light;

in response to the excitation light, detecting a second emission from the photonically active material in each of the illuminated regions; and

decoding each of the second emissions to identify individual ones of a plurality of objects.