Light emission device
AssigneesKabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
InventorsMasami Okamura, Masaaki Tamatani, Naomi Shida, Kazuaki Ootsuka, Yukihiro Fukuta
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Abstract
The present invention relates to a light emitting apparatus including a semiconductor light emitting element and a transparent ceramic phosphor for converting a wavelength of a light emitted from the semiconductor light emitting element, wherein the semiconductor light emitting element emits an ultraviolet light, and the ceramic phosphor corresponding to the semiconductor light emitting element has (i) a minimum transmission of 0.1 to 40% under a wavelength of 350-420 nm and (ii) a transmission of 10 to 90% under an emission peak wavelength of the ceramic phosphor.
Claims20
A light emitting apparatus comprising:
- a semiconductor light emitting element;
- and
- a transparent ceramic phosphor for converting a wavelength of a light emitted from the semiconductor light emitting element, wherein
- said ceramic phosphor has a relative density of 99.50 to 99.98% and has at least a part of the surface of which average surface roughness is 0.5 to 150 μm in terms of arithmetical average surface roughness Ra,
- the semiconductor light emitting element emits an ultraviolet light, and
- the ceramic phosphor corresponding to the semiconductor light emitting element has:
- a minimum transmission of 0.1 to 40% under a wavelength of 350-420 nm;
- and
- a transmission of 10 to 90% under an emission peak wavelength of the ceramic phosphor;
- and
- wherein the ceramic phosphor is composed of at least one compound selected from the group consisting of silicate, aluminate, phosphate, halo-phosphate, borate, oxide, tungstate, salt of vanadic acid, oxysulfide, sulfide, nitride and oxynitride.
A light emitting apparatus comprising:
- a semiconductor light emitting element;
- and
- a transparent ceramic phosphor for converting a wavelength of a light emitted from the semiconductor light emitting element, wherein
- said ceramic phosphor has a relative density of 99.50 to 99.98% and has at least a part of the surface of which average surface roughness is 0.5 to 150 μm in terms of arithmetical average surface roughness Ra,
- the semiconductor light emitting element emits a blue light, and
- the ceramic phosphor corresponding to the semiconductor light emitting element has:
- a minimum transmission of 20 to 80% under a wavelength of 420-500 nm;
- and
- a transmission of 10 to 90% under an emission peak wavelength of the ceramic phosphor;
- and
- wherein the ceramic phosphor is composed of at least one compound selected from the group consisting of silicate, aluminate, phosphate, halo-phosphate, borate, oxide, tungstate, salt of vanadic acid, oxysulfide, sulfide, nitride and oxynitride.
Dependencies are inferred from the claim text.