Light-emitting device and electronic apparatus using same
View Patent ↗Disclosed is a light-emitting device provided with a solid-state light-emitting element and a phosphor and emits output light. The spectral distribution of the output light has a first light component and a second light component derived from fluorescence emitted by the phosphor, and has a first minimum value between the first light component and the second light component. The first light component is a fluorescent component having a maximum intensity value within a wavelength range of 560 nm or more and less than 700 nm. The second light component is a fluorescent component having a maximum intensity value within a wavelength range of 700 nm or more and less than 2500 nm. The maximum intensity value of the second light component is greater than that of the first light component. The first minimum value is less than 50% of the maximum intensity value of the second light component.
1 . A light-emitting device comprising a solid-state light-emitting element, a first wavelength converter including a first phosphor, and a second wavelength converter including a second phosphor, and emitting output light,
wherein the first wavelength converter comprises a wavelength converter in which the first phosphor is sealed with a silicone resin, an all-inorganic wavelength converter in which the first phosphor is sealed with a low-melting-point glass, an all-inorganic wavelength converter composed of the first phosphor with a binding material, or a sintered body obtained by sintering the first phosphor,
wherein the second wavelength converter comprises a wavelength converter in which the second phosphor is sealed with a silicone resin, an all-inorganic wavelength converter in which the second phosphor is sealed with a low-melting-point glass, an all-inorganic wavelength converter composed of the second phosphor with a binding material, or a sintered body obtained by sintering the second phosphor,
wherein a spectral distribution of the output light has a first light component derived from fluorescence emitted by the first phosphor, a second light component derived from fluorescence emitted by the second phosphor, and a third light component derived from light emitted by the solid-state light-emitting element, and has a first minimum value between the first light component and the second light component, and a second minimum value between the first light component and the third light component,
the first light component is a fluorescent component having a maximum intensity value within a wavelength range of 560 nm or more and less than 700 nm,
the second light component is a fluorescent component having a maximum intensity value within a wavelength range of 700 nm or more and less than 2500 nm,
the maximum intensity value of the second light component is larger than the maximum intensity value of the first light component, and
the first minimum value and the second minimum value are less than 50% of the maximum intensity value of the second light component.
2 . The light-emitting device according to claim 1 , wherein a spectral distribution of the second light component is unimodal when spectral intensities of each wavelength of 10 nm are displayed as a histogram.
3 . The light-emitting device according to claim 1 , wherein in the second light component, a wavelength difference between a wavelength on a long-wavelength side and a wavelength on a low-wavelength side at which an intensity that is 50% of the maximum intensity value is obtained is 50 nm or more and less than 200 nm.
4 . The light-emitting device according to claim 1 , wherein a spectral distribution of the first light component is unimodal when spectral intensities of each wavelength of 10 nm are displayed as a histogram.
5 . The light-emitting device according to claim 1 , wherein in the first light component, a wavelength difference between a wavelength on a long-wavelength side and a wavelength on a low-wavelength side at which an intensity that is 60% of the maximum intensity value is obtained is 50 nm or more and less than 200 nm.
6 . The light-emitting device according to claim 1 , wherein the third light component has a maximum intensity value within a wavelength range of 350 nm or more and less than 660 nm.
7 . The light-emitting device according to claim 1 , wherein the first light component has a maximum intensity value in a wavelength range of 570 nm or more and less than 650 nm.
8 . The light-emitting device according to claim 1 , wherein the first light component is derived from fluorescence emitted by the first phosphor activated with Ce 3+ or Eu 2+ .
9 . The light-emitting device according to claim 1 , wherein the second light component is derived from fluorescence emitted by the second phosphor activated with Cr 3+ .
10 . The light-emitting device according to claim 1 , wherein the first light component includes a fluorescent component having a maximum intensity value within a wavelength range of 570 nm or more and less than 650 nm, and the fluorescent component is derived from the first phosphor, which is activated with Ce 3+ and has a garnet-type crystal structure, and
the second light component is derived from a fluorescent component of the second phosphor, which has an excitation peak within a wavelength range of 450 nm or more and less than 520 nm.
11 . The light-emitting device according to claim 1 , wherein the first light component includes a fluorescent component having a maximum intensity value within a wavelength range of 600 nm or more and less than 660 nm, and the fluorescent component is derived from the first phosphor, which is composed of a nitride or an oxynitride activated with Eu 2+ , and
the second light component is derived from a fluorescent component of the second phosphor, which has an excitation peak within a wavelength range of 600 nm or more and less than 750 nm.
12 . The light-emitting device according to claim 1 , wherein a maximum thickness of each of the first wavelength converter and the second wavelength converter is 100 μm or more and less than 5 mm.