Methods, systems, and apparatus for determining optical properties of elements of lighting components having similar color points

• US 8,589,120 B2
• Filed: 01/28/2011
• Issued: 11/19/2013
• Est. Priority Date: 01/28/2011
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Seibel, Harry A. II, Collins, Brian, Emerson, David
• Primary Examiner(s): Bui, Bryan
• Application Number:
  US13/015,996
• Publication Number:
  US 20120197599A1
• Time in Patent Office: 1,026 Days
• Field of Search: 702/189
• US Class Current: 702/189
• CPC Class Codes: G01J 1/10 by comparison with reference light or electric value provisionally void
• CPC Class Codes: G01J 3/0251 Colorimeters making use of an integrating sphere
• CPC Class Codes: G01J 3/0254 Spectrometers, other than colorimeters, making use of an integrating sphere
• CPC Class Codes: G01J 3/027 Control of working procedures of a spectrometer; Failure detection; Bandwidth calculation
• CPC Class Codes: G01J 3/465 taking into account the colour perception of the eye; using tristimulus detection
• CPC Class Codes: G01J 3/505 measuring the colour produced by lighting fixtures other than screens, monitors, displays or CRTs

Abstract

A method of determining lighting contributions of elements of a lighting component includes obtaining optical data representative of light output of the lighting component. Relative intensity data may be calculated from the optical data, and may indicate intensity differences in the light output of the lighting component as compared to that of a reference component. An optical property of an element of the lighting component is determined based on a comparison of the optical data with that of the reference component, where the reference component includes at least one reference element. Related systems and apparatus are also discussed.

Claims

1. A method of determining lighting contributions of elements of a solid state lighting component, the method comprising:

obtaining optical data representative of light output of a solid state lighting component including multiple elements; and

determining an optical property of an element of the solid state lighting component based on one or more wavelength ranges indicated by a comparison of the optical data of the solid state lighting component relative to that of a reference component including at least one reference element.

2. The method of claim 1, further comprising:

calculating, from the optical data, relative intensity data indicative of intensity differences between the light output of the lighting component and that of the reference component,

wherein the comparison indicates the one or more wavelength ranges of the intensity differences.

3. The method of claim 2, wherein the lighting component and the reference component provide respective light output having a substantially similar color point.

4. The method of claim 3, wherein the element comprises a light emitting element, and wherein the optical property comprises absorption and/or emission properties of the light emitting element.

5. The method of claim 4, wherein the at least one reference element comprises a reference light emitting element having known absorption and/or emission properties.

6. The method of claim 5, wherein the light emitting element comprises a wavelength conversion material configured to absorb light within a first wavelength range and responsively emit light within a second wavelength range, and wherein the wavelength conversion material is not included in the reference component.

7. The method of claim 6, wherein the reference light emitting element comprises a reference conversion material that is configured to absorb and re-emit light over the first and second wavelength ranges, respectively, and wherein determining the optical property comprises:

determining relative absorption and emission properties of the wavelength conversion material as compared to that of the reference conversion material over the first and second wavelength ranges, respectively.

8. The method of claim 2, further comprising:

weighting the intensity differences according to a sensitivity of the human eye over the one or more wavelength ranges,

wherein determining the optical property comprises determining the optical property according to the weighting of the intensity differences.

9. The method of claim 8, further comprising:

correlating the intensity differences to one or more characteristics of the light output of the lighting component that differ from that of the reference component according to the weighting thereof over the one or more wavelength ranges; and

attributing the intensity differences to the element of the lighting component, wherein the element is not included in the reference component.

10. The method of claim 8, wherein:

calculating the relative intensity data further comprises computing a difference function for the light output of the lighting component based on the relative intensity data; and

weighting the intensity differences comprises weighting the intensity differences based on a product of the difference function and a luminosity function approximating the sensitivity of the human eye over the one or more wavelength ranges.

11. The method of claim 9, wherein correlating comprises:

correlating the intensity differences at wavelengths between about 500 nm and about 600 nm to an increased brightness of the light output of the lighting component relative to that of the reference component.

12. The method of claim 9, wherein correlating comprises:

correlating the intensity differences at wavelengths below about 500 nm to a decreased color rendering index (CRI) of the light output of the lighting component without a substantial decrease in brightness relative to that of the reference component.

13. The method of claim 3, wherein respective color coordinates of the reference component are equal those of the lighting component up to at least a third decimal place to provide the substantially similar color point.

14. The method of claim 2, wherein the element comprises one of a plurality of elements of the lighting component that are not included in the reference component, and further comprising:

attributing the intensity differences to the element among the plurality of elements based on the one or more wavelength ranges of the intensity differences.

15. The method of claim 1, further comprising:

fabricating a light emitting device including the element of the lighting component responsive to determining the optical property thereof,

wherein the light emitting device is configured to provide a desired brightness at a substantially similar color point as the lighting component based on the determined optical property of the element.

16. The method of claim 15, wherein the light emitting device includes a light emitting diode, and further comprising:

selecting the light emitting diode for use in the light emitting device based on the determined optical property of the element.

17. A spectral analysis device, comprising:

a photodetector interface operable to obtain optical data representative of light output of a solid state lighting component including multiple elements;

a memory operable to store the optical data for the solid state lighting component and reference optical data representative of light output of a reference component including at least one reference element; and

a processor operable to determine an optical property of an element of the solid state lighting component based on one or more wavelength ranges indicated by a comparison of the optical data with the reference optical data.

18. The device of claim 17, wherein the processor is operable to calculate, from the optical data and the reference optical data, relative intensity data indicative of intensity differences between the light output of the lighting component and that of the reference component, and wherein the comparison indicates the one or more wavelength ranges of the intensity differences.

19. The device of claim 18, wherein the lighting component and the reference component provide respective light output having a substantially similar color point.

20. The device of claim 19, wherein the element comprises a light emitting element, and wherein the optical property comprises absorption and/or emission properties of the light emitting element.

21. The device of claim 20, wherein the at least one reference element comprises a reference light emitting element having known absorption and/or emission properties.

22. The device of claim 21, wherein the light emitting element comprises a wavelength conversion material configured to absorb light within a first wavelength range and responsively emit light within a second wavelength range, and wherein the wavelength conversion material is not included in the reference component.

23. The device of claim 22, wherein the reference light emitting element comprises a reference conversion material that is configured to absorb and re-emit light over the first and second wavelength ranges, and wherein the processor is operable to determine relative absorption and emission properties of the wavelength conversion material as compared to that of the reference conversion material over the first and second wavelength ranges, respectively.

24. The device of claim 18, wherein the processor is further operable to weight the intensity differences according to a sensitivity of the human eye over the one or more wavelength ranges, and to determine the optical property according to the weighting of the intensity differences.

25. The device of claim 24, wherein the element is not included in the reference component, and wherein the processor is further operable to correlate the intensity differences to one or more characteristics of the light output of the lighting component that differ from that of the reference component according to the weighting thereof over the one or more wavelength ranges, and to attribute the intensity differences to the element of the lighting component.

26. The device of claim 24, wherein the processor is operable to compute a difference function for the light output of the lighting component based on the relative intensity data, and is operable to weight the intensity differences based on a product of the difference function and a luminosity function approximating the sensitivity of the human eye over the one or more wavelength ranges.

27. A method of determining a lighting contribution of a wavelength conversion material of a lighting component, the method comprising:

calculating intensity differences in emission spectra for the lighting component relative to that of a reference component having a substantially similar color point; and

determining differences in optical properties of the wavelength conversion material independent of the lighting component relative to a wavelength conversion material of the reference component based on one or more wavelength ranges of the intensity differences.

28. The method of claim 27, wherein calculating the intensity differences comprises:

obtaining the emission spectra for each of the lighting component and the reference component;

computing a difference function indicative of the intensity differences in the emission spectra of the lighting component as compared to that of the reference component; and

weighting the intensity differences based on a product of the difference function and a luminosity function approximating a sensitivity of a human eye over the one or more wavelength ranges.

29. The method of claim 28, further comprising:

correlating the intensity differences to one or more characteristics of light output of the lighting component according to the weighting thereof over the one or more wavelength ranges.

30. A method, comprising:

receiving a signal including emission data for a solid state lighting component comprising multiple light emitting elements;

calculating relative data indicative of differences between the received emission data and reference emission data over a visible wavelength range; and

determining an optical property of one of the light emitting elements of the solid state lighting component based on one or more wavelength ranges within the visible wavelength range corresponding to the differences.

31. The method of claim 30, wherein determining comprises:

weighting the differences according to a sensitivity of the human eye over the one or more wavelength ranges;

correlating the differences to one or more characteristics of light output of the lighting component that differ from that indicated by the reference emission data according to the weighting thereof over the one or more wavelength ranges; and

attributing the one or more characteristics of the light output to one of the light emitting elements of the lighting component based on the one or more wavelength ranges corresponding to the differences.

32. The method of claim 31, wherein:

calculating comprises computing a difference function for the lighting component based on the differences over the visible wavelength range; and

weighting comprises weighting the differences based on a product of the difference function and a luminosity function approximating the sensitivity of the human eye over the one or more wavelength ranges.