Abstract: A light emitting device includes a light emitting element having a dominant wavelength in a range of 400 nm or more and 500 nm or less, and a wavelength conversion member that is arranged on a light emitting side of the light emitting element and includes a rare earth aluminate fluorescent material having a composition represented by the following formula (I), wherein the light emitting device emits light having a dominant wavelength in a range of 475 nm or more and 500 nm or less, and wherein the light emitting device emits light having an S/P ratio of 6.5 or less derived from the formula (1), which is the ratio of a luminous flux in scotopic vision relative to a luminous flux in photopic vision: (Lu1-p-nLnpCen)3(Al1-mGam)5kO12??(I) wherein in the formula (I), Ln represents at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb, and the parameters k, m, n, and p satisfy 0.95?k?1.05, 0.05?m?0.70, 0.002?n?0.050, and 0?p?0.30, respectively.

Abstract: Provided is a ceramic complex having high luminous characteristics. Proposed is a ceramic complex including a rare earth aluminate fluorescent material, glass, and calcium fluoride, wherein, when the total amount of the rare earth aluminate fluorescent material, the glass, and the calcium fluoride is taken as 100% by volume, the content of the rare earth aluminate fluorescent material is in a range of 15% by volume or more and 60% by volume or less, the content of the glass is in a range of 3% by volume or more and 84% by volume or less, and the content of the calcium fluoride is in a range of 1% by volume or more and 60% by volume of less.

Abstract: Provided are a ceramic complex capable of improving the luminous efficiency, a projector comprising a ceramic complex, and a method for producing a ceramic complex. Proposed is a ceramic complex including a rare earth aluminate fluorescent material having an average particle diameter in a range of 15 ?m or more and 40 ?m or less, aluminum oxide having a purity of aluminum oxide of 99.0% by mass or more, and voids, wherein the content of the rare earth aluminate fluorescent material is in a range of 15% by mass or more and 50% by mass or less relative to a total amount of the rare earth aluminate fluorescent material and the aluminum oxide, and a void fraction is in a range of 1% or more and 10% or less.

Abstract: A light emitting device includes a light emitting element having a dominant wavelength in a range of 400 nm or more and 500 nm or less, and a wavelength conversion member that is arranged on a light emitting side of the light emitting element and includes a rare earth aluminate fluorescent material having a composition represented by the following formula (I), wherein the light emitting device emits light having a dominant wavelength in a range of 475 nm or more and 500 nm or less, and wherein the light emitting device emits light having an S/P ratio of 6.5 or less derived from the formula (1), which is the ratio of a luminous flux in scotopic vision relative to a luminous flux in photopic vision: (Lu1-p-nLnpCen)3(Al1-mGam)5kO12??(I) wherein in the formula (I), Ln represents at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb, and the parameters k, m, n, and p satisfy 0.95?k?1.05, 0.05?m?0.70, 0.002?n?0.050, and 0?p?0.30, respectively.

Abstract: Provided is a rare earth aluminate fluorescent material and a method of producing the same. The rare earth aluminate fluorescent material contains at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd, and Tb; Ce; Al; and optionally at least one element M1 selected from Ga and Sc, wherein a total molar ratio of the rare earth element Ln and Ce is 3, a total molar ratio of Al and the element M1 is a product of 5 and a parameter k in a range of 0.95 or more and 1.05 or less, and a molar ratio of Ce is a product of a parameter n in a range of 0.003 or more and 0.017 or less and 3, and wherein a light emission peak wavelength ?p (nm) at an excitation wavelength of 450 nm and the parameter n satisfy ?p?1590n+531.

Abstract: Provided is a ceramic complex having high luminous characteristics. Proposed is a ceramic complex including a rare earth aluminate fluorescent material, glass, and calcium fluoride, wherein, when the total amount of the rare earth aluminate fluorescent material, the glass, and the calcium fluoride is taken as 100% by volume, the content of the rare earth aluminate fluorescent material is in a range of 15% by volume or more and 60% by volume or less, the content of the glass is in a range of 3% by volume or more and 84% by volume or less, and the content of the calcium fluoride is in a range of 1% by volume or more and 60% by volume of less.

Abstract: Provided are a ceramic complex capable of improving the luminous efficiency, a projector comprising a ceramic complex, and a method for producing a ceramic complex. Proposed is a ceramic complex including a rare earth aluminate fluorescent material having an average particle diameter in a range of 15 m or more and 40 ?m or less, aluminum oxide having a purity of aluminum oxide of 99.0% by mass or more, and voids, wherein the content of the rare earth aluminate fluorescent material is in a range of 15% by mass or more and 50% by mass or less relative to a total amount of the rare earth aluminate fluorescent material and the aluminum oxide, and a void fraction is in a range of 1% or more and 10% or less.

Abstract: Provided is a rare earth aluminate fluorescent material and a method of producing the same. The rare earth aluminate fluorescent material contains at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd, and Tb; Ce; Al; and optionally at least one element M1 selected from Ga and Sc, wherein a total molar ratio of the rare earth element Ln and Ce is 3, a total molar ratio of Al and the element M1 is a product of 5 and a parameter k in a range of 0.95 or more and 1.05 or less, and a molar ratio of Ce is a product of a parameter n in a range of 0.003 or more and 0.017 or less and 3, and wherein a light emission peak wavelength ?p (nm) at an excitation wavelength of 450 nm and the parameter n satisfy ?p?1590n+531.