US 2025/0052382 A1 · LIGHT-EMITTING DEVICE, LIGHTING APPLIANCE, AND STREET LIGHT

Abstract

Provided is a light-emitting device, a lighting appliance, and a street light that emit light with minimal negative effects on the behavior of sea turtles and which makes irradiated objects easily visible to humans. The light-emitting device includes a light-emitting element having an emission peak wavelength within a range from 400 nm to 490 nm; and a first phosphor having an emission peak wavelength within a range from 570 nm to 680 nm, wherein the light-emitting device, lighting appliance, and street light emit light that has a correlated color temperature of 1950 K or less, an average color rendering index Ra of 40 or greater, a full width at half maximum of an emission spectrum indicating a maximum emission intensity in an emission spectrum of the light-emitting device of 110 nm or less, and a sea turtle light attraction index T derived from Equation (1) of 0.416 or less.

Claims20

Dependent claims

A light-emitting device comprising:

a light-emitting element having an emission peak wavelength within a range from 400 nm to 490 nm;
and
a first phosphor having an emission peak wavelength within a range from 570 nm to 680 nm, wherein
the light-emitting device emits light that has a correlated color temperature of 1950 K or less, an average color rendering index Ra of 40 or greater, and a sea turtle light attraction index T derived from Equation (1) of 0.416 or less,
T
=
∫
360
700
S
(
λ
)
×
R
t
(
λ
)
⁢
d
⁢
λ
∫
380
730
S
(
λ
)
×
V
(
λ
)
⁢
d
⁢
λ
(
1
)
where S(λ) is a spectral radiance of light emitted by the light-emitting device, V(λ) is a spectral luminous efficiency function for human photopic vision specified by the Commission Internationale de l'Eclairage (CIE), and Rt(λ) is a sea turtle light response curve.

40 more elements

A light-emitting device comprising:

a light-emitting element having an emission peak wavelength within a range from 400 nm to 490 nm;
and
a first phosphor having an emission peak wavelength within a range from 570 nm to 680 nm, wherein
the first phosphor includes a first nitride phosphor having a composition represented by Formula (1A), and
the light-emitting device emits light that has a correlated color temperature of 1950 K or less, and a sea turtle light attraction index T derived from Equation (1) of 0.416 or less,
M12Si5N8:Eu (1A)
where M1 is an alkaline earth metal element including at least one selected from the group consisting of Ca, Sr, and Ba, and
T
=
∫
360
700
S
(
λ
)
×
R
t
(
λ
)
⁢
d
⁢
λ
∫
380
730
S
(
λ
)
×
V
(
λ
)
⁢
d
⁢
λ
(
1
)
where S(λ) is a spectral radiance of light emitted by the light-emitting device, V(λ) is a spectral luminous efficiency function for human photopic vision specified by the Commission Internationale de l'Eclairage (CIE), and Rt(λ) is a sea turtle light response curve.

43 more elements

Dependencies are inferred from the claim text.

Light-emitting device, lighting appliance, and street light

Life of this patent

Light-emitting device, lighting appliance, and street light

Life of this patent

Abstract

Claims20