LIGHT-EMITTING DEVICE AND METHOD FOR DESIGNING LIGHT EMITTING DEVICE
First Claim
Patent Images
1. A light-emitting device at least including, as light-emitting elements:
- a blue semiconductor light-emitting element;
a green phosphor; and
a red phosphor, whereinlight emitted from the light-emitting device in a main radiant direction satisfies all of Conditions 1 to 4 below Condition 1;
when λ
denotes wavelength, φ
SSL1(λ
) denotes a spectral power distribution of light emitted from the light-emitting device in the main radiant direction,φ
ref1(λ
) denotes a spectral power distribution of reference light which is selected in accordance with a correlated color temperature TSSL1 of the light emitted from the light-emitting device in the main radiant direction,(XSSL1, YSSL1, ZSSL1) denote tristimulus values of the light emitted from the light-emitting device in the main radiant direction, and(Xref1, Yref1, Zref1) denote tristimulus values of the reference light which is selected in accordance with TSSL1 of the light emitted from the light-emitting device in the main radiant direction, anda normalized spectral power distribution SSSL1(λ
) of the light emitted from the light-emitting device in the main radiant direction, a normalized spectral power distribution Sref1(λ
) of the reference light which is selected in accordance with TSSL1 (K) of the light emitted from the light-emitting device in the main radiant direction, and a difference Δ
SSSL1(λ
) of between normalized spectral power distributions are respectively defined as
SSSL1(λ
)=φ
SSL1(λ
)/YSSL1
Sref1(λ
)=φ
ref1(λ
)/Yref1
Δ
SSSL1(λ
)=Sref1(λ
)−
SSSL1(λ
), andin a case where λ
SSL1-RL-max (nm) represents a wavelength that provides a longest wavelength local maximum value of SSSL1(λ
) in a wavelength range of 380 nm or more and 780 nm or less, and when a wavelength Λ
4 that is represented by SSSL1(λ
SSL1-RL-max)/2 exists on a longer wavelength-side of λ
SSL1-RL-max,an index Acg(φ
SSL1(λ
)) represented by the following formula (1-1) satisfies
−
10.0<
Acg(φ
SSL1(λ
))≦
120.0,butin a case where λ
SSL1-RL-max (nm) represents a wavelength that provides the longest wavelength local maximum value of SSSL1(λ
) in a wavelength range of 380 nm or more and 780 nm or less, and when the wavelength Λ
4 that is represented by SSSL1(λ
SSL1-RL-max)/2 does not exist on the longer wavelength-side of λ
SSL1-RL-max,an index Acg(φ
SSL1(λ
)) represented by the following formula (1-2) satisfies
−
10.0<
Acg(φ
SSL1(λ
))≦
120.0;
[Expression 1]
Acg(φ
SSL1(λ
))=∫
380495Δ
SSSL1(λ
)dλ
+∫
495590(−
Δ
SSSL1(λ
))dλ
+∫
590Λ
4Δ
SSSL1(λ
)dλ
(1-1)
[Expression 2]
Acg(φ
SSL1(λ
))=∫
380495Δ
SSSL1(λ
)dλ
+∫
495590(−
Δ
SSSL1(λ
))dλ
+∫
590780Δ
SSSL1(λ
)dλ
(1-2)Condition 2;
a distance Duv(φ
SSL1(λ
)) of the spectral power distribution φ
SSL1(λ
) of light from a black-body radiation locus defined by ANSI C78.377 satisfies
−
0.0220≦
Duv(φ
SSL1(λ
))≦
−
0.0070;
Condition 3;
when a maximum value of spectral intensity in a range of 430 nm or more and 495 nm or less is defined as φ
SSL1-BM-max and a minimum value of spectral intensity in a range of 465 nm or more and 525 nm or less is defined as φ
SSL1-BG-min, the spectral power distribution φ
SSL1(λ
) of light satisfies
0.2250≦
φ
SSL1-BG-min/φ
SSL1-BM-max≦
0.7000; and
Condition 4;
in the spectral power distribution φ
SSL1(λ
) of light, when a maximum value of spectral intensity in a range of 590 nm or more and 780 nm or less is defined as φ
SSL1-RM-max, a wavelength λ
SSL1-RM-max that provides φ
SSL1-RM-max satisfies
605 (nm)≦
λ
SSL1-RM-max≦
653 (nm).
1 Assignment
0 Petitions
Accused Products
Abstract
It is an object of the present invention to improve light source efficiency of “a light-emitting device capable of realizing a natural, vivid, highly visible and comfortable appearance of colors or an appearance of objects” already arrived at by adopting a spectral power distribution having a shape completely different from the shape of conventionally known spectral power distributions while maintaining favorable color appearance characteristics.
28 Citations
20 Claims
-
1. A light-emitting device at least including, as light-emitting elements:
-
a blue semiconductor light-emitting element; a green phosphor; and a red phosphor, wherein light emitted from the light-emitting device in a main radiant direction satisfies all of Conditions 1 to 4 below Condition 1; when λ
denotes wavelength, φ
SSL1(λ
) denotes a spectral power distribution of light emitted from the light-emitting device in the main radiant direction,φ
ref1(λ
) denotes a spectral power distribution of reference light which is selected in accordance with a correlated color temperature TSSL1 of the light emitted from the light-emitting device in the main radiant direction,(XSSL1, YSSL1, ZSSL1) denote tristimulus values of the light emitted from the light-emitting device in the main radiant direction, and (Xref1, Yref1, Zref1) denote tristimulus values of the reference light which is selected in accordance with TSSL1 of the light emitted from the light-emitting device in the main radiant direction, and a normalized spectral power distribution SSSL1(λ
) of the light emitted from the light-emitting device in the main radiant direction, a normalized spectral power distribution Sref1(λ
) of the reference light which is selected in accordance with TSSL1 (K) of the light emitted from the light-emitting device in the main radiant direction, and a difference Δ
SSSL1(λ
) of between normalized spectral power distributions are respectively defined as
SSSL1(λ
)=φ
SSL1(λ
)/YSSL1
Sref1(λ
)=φ
ref1(λ
)/Yref1
Δ
SSSL1(λ
)=Sref1(λ
)−
SSSL1(λ
), andin a case where λ
SSL1-RL-max (nm) represents a wavelength that provides a longest wavelength local maximum value of SSSL1(λ
) in a wavelength range of 380 nm or more and 780 nm or less, and when a wavelength Λ
4 that is represented by SSSL1(λ
SSL1-RL-max)/2 exists on a longer wavelength-side of λ
SSL1-RL-max,an index Acg(φ
SSL1(λ
)) represented by the following formula (1-1) satisfies
−
10.0<
Acg(φ
SSL1(λ
))≦
120.0,but in a case where λ
SSL1-RL-max (nm) represents a wavelength that provides the longest wavelength local maximum value of SSSL1(λ
) in a wavelength range of 380 nm or more and 780 nm or less, and when the wavelength Λ
4 that is represented by SSSL1(λ
SSL1-RL-max)/2 does not exist on the longer wavelength-side of λ
SSL1-RL-max,an index Acg(φ
SSL1(λ
)) represented by the following formula (1-2) satisfies
−
10.0<
Acg(φ
SSL1(λ
))≦
120.0;
[Expression 1]
Acg(φ
SSL1(λ
))=∫
380495Δ
SSSL1(λ
)dλ
+∫
495590(−
Δ
SSSL1(λ
))dλ
+∫
590Λ
4Δ
SSSL1(λ
)dλ
(1-1)
[Expression 2]
Acg(φ
SSL1(λ
))=∫
380495Δ
SSSL1(λ
)dλ
+∫
495590(−
Δ
SSSL1(λ
))dλ
+∫
590780Δ
SSSL1(λ
)dλ
(1-2)Condition 2; a distance Duv(φ
SSL1(λ
)) of the spectral power distribution φ
SSL1(λ
) of light from a black-body radiation locus defined by ANSI C78.377 satisfies
−
0.0220≦
Duv(φ
SSL1(λ
))≦
−
0.0070;Condition 3; when a maximum value of spectral intensity in a range of 430 nm or more and 495 nm or less is defined as φ
SSL1-BM-max and a minimum value of spectral intensity in a range of 465 nm or more and 525 nm or less is defined as φ
SSL1-BG-min, the spectral power distribution φ
SSL1(λ
) of light satisfies
0.2250≦
φ
SSL1-BG-min/φ
SSL1-BM-max≦
0.7000; andCondition 4; in the spectral power distribution φ
SSL1(λ
) of light, when a maximum value of spectral intensity in a range of 590 nm or more and 780 nm or less is defined as φ
SSL1-RM-max, a wavelength λ
SSL1-RM-max that provides φ
SSL1-RM-max satisfies
605 (nm)≦
λ
SSL1-RM-max≦
653 (nm).- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
3. The light-emitting device according to claim 1, wherein
in Condition 4,
625 (nm)≦- λ
SSL1-RM-max≦
647 (nm) is satisfied.
- λ
-
4. The light-emitting device according to claim 1, wherein Condition 5 below is satisfied
Condition 5: in the spectral power distribution φ
SSL1(λ
) of light, a wavelength λ
SSL1-BM-max that provides φ
SSL1-BM-max satisfies
430 (nm)≦
λ
SSL1-BM-max≦
480 (nm).
-
5. The light-emitting device according to claim 1, wherein Condition 6 below is satisfied
Condition 6:
0.1800≦
φ
SSL1-BG-min/φ
SSL1-RM-max≦
0.8500.
-
6. The light-emitting device according to claim 5, wherein
in Condition 6,
0.1917≦- φ
SSL1-BG-min/φ
SSL1-RM-max≦
0.7300 is satisfied.
- φ
-
7. The light-emitting device according to claim 1, wherein a luminous efficacy of radiation KSSL1 (lm/W) in a wavelength range of 380 nm or more and 780 nm or less, which is derived from φ
-
SSL1(λ
), satisfies Condition 7Condition 7;
210.0 lm/W≦
KSSL1≦
290.0 lm/W.
-
SSL1(λ
-
8. The light-emitting device according to claim 1, wherein TSSL1 (K) satisfies Condition 8 below
Condition 8:
2600 K≦
TSSL1≦
7700 K.
-
9. The light-emitting device according to claim 1, wherein
φ -
SSL1(λ
) does not have effective intensity derived from the light-emitting element in a range of 380 nm or more and 405 nm or less.
-
SSL1(λ
-
10. The light-emitting device according to claim 1, wherein
the blue semiconductor light-emitting element is configured such that a dominant wavelength λ - CHIP-BM-dom of the blue semiconductor light-emitting element alone when pulse-driven is 445 nm or more and 475 nm or less.
-
11. The light-emitting device according to claim 1, wherein
the green phosphor is a wide-band green phosphor. -
12. The light-emitting device according to claim 1, wherein
the green phosphor is configured such that a wavelength λ -
PHOS-GM-max that provides maximum emission intensity when light is excited by the green phosphor alone is 511 nm or more and 543 nm or less, and
a full-width at half-maximum WPHOS-GM-fwhm thereof is 90 nm or more and 110 nm or less.
-
PHOS-GM-max that provides maximum emission intensity when light is excited by the green phosphor alone is 511 nm or more and 543 nm or less, and
-
13. The light-emitting device according to claim 1, wherein the light-emitting device includes substantially no yellow phosphor.
-
14. The light-emitting device according to claim 1, wherein
the red phosphor is configured such that a wavelength λ -
PHOS-RM-max that provides maximum emission intensity when light is excited by the red phosphor alone is 622 nm or more and 663 nm or less, and
a full-width at half-maximum WPHOS-RM-fwhm thereof is 80 nm or more and 105 nm or less.
-
PHOS-RM-max that provides maximum emission intensity when light is excited by the red phosphor alone is 622 nm or more and 663 nm or less, and
-
15. The light-emitting device according to claim 1, wherein
the blue semiconductor light-emitting element is an AlInGaN light-emitting element. -
16. The light-emitting device according to claim 1, wherein
the green phosphor is Ca3(Sc,Mg)2Si3O12: - Ce (CSMS phosphor), CaSc2O4;
Ce (CSO phosphor), Lu3Al5O12;
Ce (LuAG phosphor), or Y3(Al,Ga)5O12;
Ce (G-YAG phosphor).
- Ce (CSMS phosphor), CaSc2O4;
-
17. The light-emitting device according to claim 1, wherein
the red phosphor includes (Sr,Ca)AlSiN3: - Eu (SCASN phosphor), CaAlSi(ON)3;
Eu (CASON phosphor), or CaAlSiN3;
Eu (CASN phosphor).
- Eu (SCASN phosphor), CaAlSi(ON)3;
-
18. The light-emitting device according to claim 1, wherein the blue semiconductor light-emitting element is an AlInGaN light-emitting element with a dominant wavelength λ
-
CHIP-BM-dom when the blue semiconductor light-emitting element alone is pulse-driven, of 452.5 nm or more and 470 nm or less,
the green phosphor is CaSc2O4;
Ce (CSO phosphor) or Lu3Al5O12;
Ce (LuAG phosphor) with a wavelength XPHOS-GM-max that provides maximum emission intensity when light is excited by the green phosphor alone, of 515 nm or more and 535 nm or less, and a full-width at half-maximum WPHOS-GM-fwhm of 90 nm or more and 110 nm or less, andthe red phosphor is CaAlSi(ON)3;
Eu (CASON phosphor) or CaAlSiN3;
Eu (CASN phosphor) with a wavelength that provides maximum emission intensity λ
PHOS-RM-max when light is excited by the red phosphor alone, of 640 nm or more and 663 nm or less, and a full-width at half-maximum WPHOS-RM-fwhm of 80 nm or more and 105 nm or less.
-
CHIP-BM-dom when the blue semiconductor light-emitting element alone is pulse-driven, of 452.5 nm or more and 470 nm or less,
-
19. The light-emitting device according to claim 1, wherein the light-emitting device is a packaged LED, a chip-on-board LED, an LED module, an LED light bulb, an LED lighting fixture, or an LED lighting system.
-
20. The light-emitting device according to claim 1, wherein
the light emitted from the light-emitting device in the main radiant direction satisfies Conditions I to IV below Condition I: -
when a*nSSL1 and b*nSSL1 (where n is a natural number from 1 to
15) respectively denote the a* value and b* value in the CIE 1976 L*a*b* color space of the following 15 Munsell renotation color samples of #01 to #15 based on a mathematical assumption that illumination is performed by the light emitted from the light-emitting device in the main radiant direction, andwhen a*nref1 and b*nref1 (where n is a natural number from 1 to
15) respectively denote the a* value and b* value in the CIE 1976 L*a*b* color space of the 15 Munsell renotation color samples based on a mathematical assumption that illumination is performed by reference light which is selected in accordance with the correlated color temperature TSSL1(K) of the light emitted in the main radiant direction, each saturation difference Δ
CnSSL1 satisfies
−
4.00≦
Δ
CnSSL1≦
8.00 (where n is a natural number from 1 to
15);Condition II; an average saturation difference represented by the following formula (1-3) satisfies
-
Specification
-
- Resources
Litigation Campaign Assessment
Thank you for your request. You will receive a custom alert email when the Litigation Campaign Assessment is available.
×
-
Current AssigneeCitizen Electronics Company Limited
-
Original AssigneeCitizen Electronics Company Limited
-
InventorsHORIE, Hideyoshi
-
Granted Patent
-
Time in Patent OfficeDays
-
Field of Search
-
US Class Current1/1
-
CPC Class CodesC09K 11/08 containing inorganic lumine...C09K 11/77348 Silicon Aluminium Nitrides ...C09K 11/7769 Oxides C09K11/7768 takes pr...C09K 11/7774 AluminatesC09K 11/77742 SilicatesH01L 33/504 Elements with two or more w...
