US 2025/0052381 A1Published application

Light emitting device, light fixture, and street light

AssigneeNichia Corporation

InventorsMika MATSUMOTO, Kazushige FUJIO

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Abstract

A light emitting device comprises a light emitting element having a light emission peak wavelength in a range of 400 nm or more and 490 nm or less and a first fluorescent material having a light emission peak wavelength in a range of 570 nm or more and 680 nm or less, and emits light having a correlated color temperature being 1,950 K or less, an average color rendering index Ra being 70 or more, a full width at half maximum of a light emission peak having the maximum light emission intensity being 110 nm or less, and a ratio B/L of an effective radiance B to a luminance L being 0.151 or less, wherein the luminance of light emitted by the light emitting device in a range of 300 nm or more and 800 nm or less when B and L is as defined in the disclosure.

Claims20

Dependent claims

A light emitting device, comprising a light emitting element having a light emission peak wavelength in a range of 400 nm or more and 490 nm or less and a first fluorescent material having a light emission peak wavelength in a range of 570 nm or more and 680 nm or less,

the light emitting device emitting light having a correlated color temperature being 1,950 K or less, an average color rendering index Ra being 70 or more, and a first scattering index B/L of an effective radiance B to a luminance L, as defined by the following formula (1), being 0.151 or less,
wherein L is the luminance of light emitted by the light emitting device in a range of 300 nm or more and 800 nm or less in consideration of a photopic standard specific luminous sensitivity curve of humans specified by CIE (Commission Internationale de l′Eclairage), and B is the effective radiance of light emitted by the light emitting device in a range of 300 nm or more and 800 nm or less in consideration of a scattering intensity curve for wavelengths when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is 1:
B
/
L
=
∫
300
800
⁢
Dc
⁡
(
λ
)
×
S
⁡
(
λ
)
⁢
d
⁢
λ
∫
300
800
⁢
S
⁡
(
λ
)
×
V
⁡
(
λ
)
⁢
d
⁢
λ
(
1
)
wherein S (λ) represents a spectral radiance of light emitted by the light emitting device, V (λ) represents a photopic standard specific luminous sensitivity curve of humans specified by CIE (Commission Internationale de l'Eclairage), and Dc (λ) represents a scattering intensity curve for wavelengths when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is 1 in Rayleigh scattering.

45 more elements

the light emitting device emitting light having a correlated color temperature being 1,950 K or less, an average color rendering index Ra being 70 or more, and a second scattering index B/A of an effective radiance B to a radiance A, as defined by the following formula (2), being 0.060 or less,
wherein A is the radiance of light emitted by the light emitting device in a range of 300 nm or more and 800 nm or less, and B is the effective radiance of light emitted by the light emitting device in a range of 300 nm or more and 800 nm or less in consideration of a scattering intensity curve for wavelengths when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is 1:
B
/
A
=
∫
300
800
⁢
Dc
⁡
(
λ
)
×
S
⁡
(
λ
)
⁢
d
⁢
λ
∫
300
800
⁢
S
⁡
(
λ
)
⁢
d
⁢
λ
(
2
)
wherein S (λ) represents a spectral radiance of light emitted by the light emitting device and Dc (λ) represents a scattering intensity curve for wavelengths when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is 1 in Rayleigh scattering.

39 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/928,790Filed 28 Oct 2024
Priority: JP 2021-07439226 Apr 2021
Published: 13 Feb 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

F21K 9/64
Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction: using wavelength…
H10H 20/8512
Characterised by their material, e.g. binder: wavelength conversion materials
C09K 11/77348
Containing europium: silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
C09K 11/7774
Containing two or more rare earth metals: aluminates

Family

Application17/660,784Continuation · filed 26 Apr 2022
Application18/928,790Continuation
US 12,163,632 B2Related patent
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US 2025/0052381 A1This patent

From the US filing history. Foreign family members aren’t listed.