MULTIWAVELENGTH SOLID-STATE LAMPS WITH AN ENHANCED NUMBER OF RENDERED COLORS

• US 20090200907A1
• Filed: 02/10/2009
• Published: 08/13/2009
• Est. Priority Date: 02/11/2008
• Status: Active Grant

• Current Assignee: Sensor Electronic Technology Incorporated (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Sensor Electronic Technology Incorporated (Seoul Semiconductor Co., Ltd.)
• Inventors: Shur, Michael, Vaicekauskas, Rimantas, Ivanauskas, Feliksas, Vaitkevicius, Henrikas, Zukauskas, Arturas
• Granted Patent: US 8,436,526 B2
• Time in Patent Office: Days
• US Class Current: 313/1
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules

Abstract

The current invention discloses polychromatic sources of white light, which are composed of at least two groups of colored emitters, such as light-emitting diodes (LEDs) are disclosed. Based on a novel approach of the assessment of quality of white light using 1269 test color samples from the enhanced Munsell palette, the spectral compositions of white light composed of two to five (or more) narrow-band emissions with the highest number of colors relevant to human vision rendered almost indistinguishably from a blackbody radiator are introduced. An embodiment of the current invention can be used, in particular, for designing polychromatic sources of white light with the ultimate quality capable of rendering of all colors of the real world.

Claims

1. A lighting source, having a predetermined correlated color temperature, comprising:

at least two sets of visible-light emitters, each set of emitters having a primary color, the primary colors and relative fluxes generated by each set of emitters being selected such that in comparison with a reference lighting source, when each of more than fourteen test color samples resolved by an average human eye as different is illuminated;

(a) chromaticity shifts with a chromatic adaptation of human vision taken into account are preserved within corresponding regions of a chromaticity diagram, each containing all colors that are indistinguishable, to the average human eye, from a color at a center of the region; and

(b) lightness shifts are preserved within predetermined values.

2. The lighting source of claim 1, wherein the primary colors and partial fluxes are selected in such a way that in comparison with a reference source for the illuminated test color samples the chromaticity shifts are preserved within 3-step MacAdam ellipses and the lightness shifts are preserved within 2%.

3. The lighting source of claim 1, wherein the emitters comprise light emitting diodes, and wherein the light source comprises two to five sets of the light-emitting diodes, selected from the group consisting of:

two sets of colored light-emitting diodes, with peak wavelengths of around 455-505 nm and 560-610 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples;

three sets of colored light-emitting diodes, with peak wavelengths of around 445-490 nm, 515-560 nm, and 580-625 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples;

four sets of colored light-emitting diodes, with peak wavelengths of around 440-480 nm, 500-540 nm, 550-600 nm, and 600-650 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples; and

five sets of colored light-emitting diodes, with peak wavelengths of around 440-465 nm, 490-515 nm, 540-565 nm, 590-615 nm, and 640-665 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples;

with a correlated color temperature in the range of around 2500 to 10000 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes.

4. The lighting source of claim 3, wherein the primary colors and partial fluxes are selected in such a way that in comparison with a reference source for the illuminated test color samples the chromaticity shifts are preserved within 3-step MacAdam ellipses and the lightness shifts are preserved within 2%.

5. The lighting source of claim 1, comprising three to five sets of the light-emitting diodes, selected from the group consisting of:

three sets of colored light-emitting diodes with the peak wavelengths of the light emitting diodes around 457 nm, 526 nm, and 595 nm, and with the correlated color temperature of around 6500 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes to about 0.34, 0.31, and 0.35, respectively, wherein the chromaticity and lightness shifts are preserved for more than about 70 percent of an average highest possible number of different test color samples;

four sets of colored light-emitting diodes with the peak wavelengths of the light-emitting diodes around 458 nm, 522 nm, 575 nm, and 625 nm, and with the correlated color temperature of around 6500 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes to about 0.32, 0.26, 0.20, and 0.22, respectively, wherein the chromaticity and lightness shifts are preserved for more than about 70 percent of an average highest possible number of different test color samples; and

five sets of colored light-emitting diodes with the peak wavelengths of the light-emitting diodes around 449 nm, 502 nm, 552 nm, 600 nm, and 652 nm, and with the correlated color temperature of around 6500 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes to about 0.24, 0.21, 0.19, 0.17, and 0.19, respectively, wherein the chromaticity and lightness shifts are preserved for more than about 70 percent of an average highest possible number of different test color samples.

6. The lighting source of claim 5 wherein the primary colors and partial fluxes are selected in such a way that in comparison with a reference source for the illuminated test color samples the chromaticity shifts are preserved within 3-step MacAdam ellipses and the lightness shifts are preserved within 2%.

7. The lighting source of claim 1, further comprising:

at least one package comprising the at least two sets of emitters, each set of emitters having a different peak wavelength.

8. The lighting source of claim 7, wherein the at least one package is integrated in a semiconductor chip, and wherein the peak wavelength of each set of emitters is adjusted by tailoring at least one of a chemical composition of an active layer or a thickness of the active layer forming each emitter.

9. The lighting source of claim 1, further comprising:

a component for uniformly distributing radiation from the at least two sets of light emitters over an illuminated object.

10. A lighting method, comprising:

selecting at least two sets of visible-light emitters, each set of emitters having a primary color, the primary colors and relative fluxes generated by each set of emitters being selected such that in comparison with a reference lighting source, when each of more than eight test color samples resolved by an average human eye as different is illuminated;

(a) chromaticity shifts with a chromatic adaptation of human vision taken into account are preserved within corresponding regions of a chromaticity diagram, each containing all colors that are indistinguishable, to the average human eye, from a color at a center of the region; and

(b) lightness shifts are preserved within predetermined values.

11. The lighting method of claim 10, wherein the primary colors and partial fluxes are selected in such a way that in comparison with a reference source for the illuminated test color samples the chromaticity shifts are preserved within 3-step MacAdam ellipses and the lightness shifts are preserved within 2%.

12. The lighting method of claim 10, wherein the emitters comprise light emitting diodes, and wherein the light source comprises two to five sets of the light-emitting diodes, selected from the group consisting of:

two sets of colored light-emitting diodes, with peak wavelengths of around 455-505 nm and 560-610 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples;

three sets of colored light-emitting diodes, with peak wavelengths of around 445-490 nm, 515-560 nm, and 580-625 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples;

four sets of colored light-emitting diodes, with peak wavelengths of around 440-480 nm, 500-540 nm, 550-600 nm, and 600-650 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples; and

five sets of colored light-emitting diodes, with peak wavelengths of around 440-465 nm, 490-515 nm, 540-565 nm, 590-615 nm, and 640-665 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples;

with a correlated color temperature in the range of around 2500 to 10000 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes.

13. The lighting method of claim 12, wherein the primary colors and partial fluxes are selected in such a way that in comparison with a reference source for the illuminated test color samples the chromaticity shifts are preserved within 3-step MacAdam ellipses and the lightness shifts are preserved within 2%.

14. The lighting method of claim 10, comprising three to five sets of the light-emitting diodes, selected from the group consisting of:

three sets of colored light-emitting diodes with the peak wavelengths of the light emitting diodes around 457 nm, 526 nm, and 595 nm, and with the correlated color temperature of around 6500 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes to about 0.34, 0.31, and 0.35, respectively, wherein the chromaticity and lightness shifts are preserved for more than about 70 percent of an average highest possible number of different test color samples;

four sets of colored light-emitting diodes with the peak wavelengths of the light-emitting diodes around 458 nm, 522 nm, 575 nm, and 625 nm, and with the correlated color temperature of around 6500 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes to about 0.32, 0.26, 0.20, and 0.22, respectively, wherein the chromaticity and lightness shifts are preserved for more than about 70 percent of an average highest possible number of different test color samples; and

five sets of colored light-emitting diodes with the peak wavelengths of the light-emitting diodes around 449 nm, 502 nm, 552 nm, 600 nm, and 652 nm, and with the correlated color temperature of around 6500 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes to about 0.24, 0.21, 0.19, 0.17, and 0.19, respectively, wherein the chromaticity and lightness shifts are preserved for more than about 70 percent of an average highest possible number of different test color samples.

15. The lighting method of claim 14, wherein the primary colors and partial fluxes are selected in such a way that in comparison with a reference source for the illuminated test color samples the chromaticity shifts are preserved within 3-step MacAdam ellipses and the lightness shifts are preserved within 2%.

16. The lighting method of claim 10, further comprising:

uniformly distributing radiation from the at least two sets of light emitters over an illuminated object.

17. A lighting method, comprising:

generating white light using at least two sets of visible-light emitters, each set of emitters having a primary color, the primary colors and relative fluxes generated by each set of emitters being selected such that in comparison with a reference lighting source, when each of more than eight test color samples resolved by an average human eye as different is illuminated;

(a) chromaticity shifts with a chromatic adaptation of human vision taken into account are preserved within corresponding regions of a chromaticity diagram, each containing all colors that are indistinguishable, to the average human eye, from a color at a center of the region; and

(b) lightness shifts are preserved within predetermined values.

18. The lighting method of claim 17, wherein the primary colors and partial fluxes are selected in such a way that in comparison with a reference source for the illuminated test color samples the chromaticity shifts are preserved within 3-step MacAdam ellipses and the lightness shifts are preserved within 2%.

19. The lighting method of claim 17, wherein the emitters comprise light emitting diodes, and wherein the light source comprises two to five sets of the light-emitting diodes, selected from the group consisting of:

two sets of colored light-emitting diodes, with peak wavelengths of around 455-505 nm and 560-610 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples;

three sets of colored light-emitting diodes, with peak wavelengths of around 445-490 nm, 515-560 nm, and 580-625 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples;

four sets of colored light-emitting diodes, with peak wavelengths of around 440-480 nm, 500-540 nm, 550-600 nm, and 600-650 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples; and

five sets of colored light-emitting diodes, with peak wavelengths of around 440-465 nm, 490-515 nm, 540-565 nm, 590-615 nm, and 640-665 nm, wherein the chromaticity and lightness shifts are preserved for more than about 35 percent of an average highest possible number of different test color samples;

with a correlated color temperature in the range of around 2500 to 10000 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes.

20. The lighting method of claim 19, wherein the primary colors and partial fluxes are selected in such a way that in comparison with a reference source for the illuminated test color samples the chromaticity shifts are preserved within 3-step MacAdam ellipses and the lightness shifts are preserved within 2%.

21. The lighting method of claim 17, comprising three to five sets of the light-emitting diodes, selected from the group consisting of:

three sets of colored light-emitting diodes with the peak wavelengths of the light emitting diodes around 457 nm, 526 nm, and 595 nm, and with the correlated color temperature of around 6500 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes to about 0.34, 0.31, and 0.35, respectively, wherein the chromaticity and lightness shifts are preserved for more than about 70 percent of an average highest possible number of different test color samples;

four sets of colored light-emitting diodes with the peak wavelengths of the light-emitting diodes around 458 nm, 522 nm, 575 nm, and 625 nm, and with the correlated color temperature of around 6500 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes to about 0.32, 0.26, 0.20, and 0.22, respectively, wherein the chromaticity and lightness shifts are preserved for more than about 70 percent of an average highest possible number of different test color samples; and

five sets of colored light-emitting diodes with the peak wavelengths of the light-emitting diodes around 449 nm, 502 nm, 552 nm, 600 nm, and 652 nm, and with the correlated color temperature of around 6500 K set by adjusting the relative fluxes generated by each set of colored light-emitting diodes to about 0.24, 0.21, 0.19, 0.17, and 0.19, respectively, wherein the chromaticity and lightness shifts are preserved for more than about 70 percent of an average highest possible number of different test color samples.

22. The lighting method of claim 21, wherein the primary colors and partial fluxes are selected in such a way that in comparison with a reference source for the illuminated test color samples the chromaticity shifts are preserved within 3-step MacAdam ellipses and the lightness shifts are preserved within 2%.

23. The lighting method of claim 17, further comprising:

uniformly distributing radiation from the at least two sets of light emitters over an illuminated object.