Light-emitting device
AssigneesNational Institute of Advanced Industrial Science and Technology, Phoenix Electric Co., Ltd., National Institute for Materials Science
InventorsTakashi Fukuda, Tetsuya Gouda, Yuta Sakimoto, Naoto Hirosaki, Kohsei Takahashi
Life of this patent
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Abstract
A light-emitting device including a solid-state light source that emits light having a peak wavelength in the range of 480 nm or less and a fluorescent film that covers the solid-state light source and includes at least one kind of phosphor, wherein the fluorescent film includes at least one kind of near-infrared phosphor that is excited by light from the solid-state light source, has a peak wavelength in the range exceeding 700 nm, and has an emission spectrum with a full width at half maximum of 100 nm or more in a range including the peak wavelength.
Claims12
A light-emitting device comprising at least a solid-state light source that emits light having a peak wavelength in the range of 480 nm or less and a fluorescent film that covers the solid-state light source and includes at least one kind of phosphor, wherein
- the fluorescent film includes at least one kind of near-infrared phosphor that is excited by light from the solid-state light source and emits light having a peak wavelength in the range exceeding 700 nm and having an emission spectrum with a full width at half maximum of 100 nm or more in a range including the peak wavelength,
- the light emitting device has a continuous emission spectrum at least in the range of 400 nm or more to 1,000 nm or less, and
- the continuous emission spectrum means the emission intensity of the emission spectrum is 0.01 or more, as a value relative to an 800 nm reference, across the entire region within this range.
A fluorescent film including:
- at least one kind of near-infrared phosphor that, due to light having a peak wavelength in the range of 480 nm or less, emits light having a peak wavelength in the range exceeding 700 nm and having an emission spectrum with a full width at half maximum of 100 nm or more in a range including the peak wavelength;
- and at least one kind of visible phosphor that, due to the light, emits light having a peak wavelength in the range of 350 nm or more to 700 nm or less,
- wherein the near-infrared phosphor has a composition represented by formula (I)
- LiaSrbLacSidNeEuf (I)
- wherein a-f are numbers satisfying:
- a+b+c+d+e+f=100;
- and 0<a≤8.22, 0.22≤b≤17.33, 1.12≤c≤11.36, 22.41≤d≤38.09, 49.47≤e≤56.09, and 0.88≤f≤1.01.
Dependencies are inferred from the claim text.