Light emitting device provided with a wavelength conversion unit incorporating plural kinds of phosphors
AssigneeSharp Kabushiki Kaisha
InventorsMasatsugu Masuda, Masaaki Katoh, Tsukasa Inoguchi
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Abstract
A light-emitting device includes a light-emitting element for emitting primary light, and a wavelength conversion unit for absorbing part of the primary light and emitting secondary light having a wavelength longer than that of the primary light, wherein the wavelength conversion unit includes plural kinds of phosphors having light absorption characteristics different from each other, and then at least one kind of phosphor among the plural kinds of phosphors has an absorption characteristic that can absorb the secondary light emitted from at least another kind of phosphor among the plural kinds of phosphors.
Claims11
A light-emitting device, comprising:
- a light-emitting element for emitting primary light;
- and
- a wavelength conversion unit for absorbing at least part of said primary light and emitting secondary light having a wavelength longer than that of the primary light;
- wherein
- said wavelength conversion unit includes at least a phosphor for emitting green light and a phosphor for emitting red light, and
- said phosphor for emitting red light includes a divalent europium-activated nitride phosphor represented by (M31-8Eug)M4SiN3, where M3 represents at least one kind of element selected from Mg, Ca, Sr and Ba;
- M4 represents at least one kind of element selected from Al, Ga, In, Sc, Y, La, Gd and Lu;
- and g represents a number satisfying 0.001≦g≦0.05.
Dependencies are inferred from the claim text.