The purpose of the present invention is to provide a mechanoluminescent material which can be exhibit brighter luminescence compared to traditional SAO mechanoluminescent material even with respect to small strains and which has a relatively high mechanoluminescent capability even when left to stand for a long period of time after excitation. Provided is a strontium aluminate mechanoluminescent material containing Zr ions, characterized in that the Zr ions are contained in a reduced state, the content of the Zr ions is 10 mol % or less, and in a thermoluminescence measurement, one or more luminescence peaks are observed at a temperature of 100° C. or higher.

A device including an LED light source optically coupled to a phosphor selected from [Y,Gd,Tb,La,Sm,Pr,Lu].sub.3[Al,Ga].sub.5−aO.sub.12−3/2a:Ce.sup.3+ (wherein 0<a<0.5), beta-SiAlON:Eu.sup.2+, [Sr,Ca,Ba][Al,Ga,In].sub.2S.sub.4:Eu.sup.2+, alpha-SiAlON doped with Eu.sup.2+ and/or Ce.sup.3+, Ca.sub.1−h−rCe.sub.hEu.sub.rAl.sub.1−h[Mg,Zn].sub.hSiN.sub.3, (where 0<h<0.2, 0<r<0.2), Sr(LiAl.sub.3N.sub.4):Eu.sup.2+, [Ca,Sr]S:Eu.sup.2+ or Ce.sup.3+, [Ba,Sr,Ca].sub.bSi.sub.gN.sub.m:Eu.sup.2+ (wherein 2b+4g=3m), quantum dot materials, and combinations thereof; and a green-emitting U.sup.6+-doped phosphor having a composition selected from the group consisting of U.sup.6+-doped phosphate-vanadate phosphors, U.sup.6+-doped halide phosphors, U.sup.6+-doped oxyhalide phosphors, U.sup.6+-doped silicate-germanate phosphors, U.sup.6+-doped alkali earth oxide phosphors, and combinations thereof, is presented.

Provided are an aluminate fluorescent material, a light emitting device, and a method for producing an aluminate fluorescent material. The aluminate fluorescent material, having an aluminate composition containing: at least one alkaline earth metal element selected from the group consisting of Ba, Sr, and Ca; Mn; and optionally Eu and/or Mg, wherein the fluorine content in the aluminate fluorescent material is 100 ppm or more and 7,000 ppm or less, and the average particle diameter of the aluminate fluorescent material, which is measured according to a Fisher Sub-Sieve Sizer method, is 8 μm or more.

Provided is an aluminate fluorescent material having a high emission intensity and having a composition containing a first element that contains one or more of Ba and Sr, and a second element that contains Mg and Mn. In the composition, when a molar ratio of Al is 10, a total molar ratio of the first element is a parameter a, a total molar ratio of the second element is a parameter b, a molar ratio of Sr is a product of a parameter m and the parameter a, a molar ratio of Mn is a product of a parameter n and the parameter b. The parameters a and b satisfy 0.5<b<a≤0.5b+0.5<1.0, the parameter m satisfies 0≤m≤1.0, and the parameter n satisfies 0.4≤n≤0.7.

A pearlescent pigment for security purposes according to an embodiment of the present invention includes a single or a plurality of coating layers containing a metal oxide and an organic or inorganic fluorescent material. Since the pearlescent pigment for security purposes according to the present disclosure includes a fluorescent layer containing the organic or inorganic fluorescent material, it can be used as a pigment for security purposes due to its optical characteristics and can also provide effects such as magnetism, high color intensity, multiple colors, etc. Also, since the pearlescent pigment for security purposes has aesthetic benefit and security characteristic at the same time, it is economical, easy to use and applicable in various industries.

A wavelength converting member comprising a first wavelength converting layer containing: a first fluorescent material having a light emission peak wavelength in a range of 620 nm or more and 660 nm or less; a second fluorescent material having a light emission peak wavelength in a range of 510 nm or more and 560 nm or less; and a resin, wherein the average particle diameter, as measured according to a Fisher Sub-Sieve Sizer method, of the first fluorescent material is in a range of 2 m or more and 30 m or less, wherein the second fluorescent material comprises a -SiAlON fluorescent material, the circularity of the -SiAlON fluorescent material is 0.7 or more, and the volume average particle diameter, as measured according to a laser diffraction scattering particle size distribution measuring method, of the -SiAlON fluorescent material is in a range of 2 m or more and 30 m or less, and wherein the thickness of the first wavelength converting layer is in a range of 50 m or more and 200 m or less.

Provided are a light-emitting instrument, and an image display device utilizing an AlON phosphor and having wide color gamut. The light-emitting instrument includes an emission source emitting light having a wavelength from 410 nm to 470 nm and a phosphor or a light-transmitting body where the phosphor is dispersed, and the phosphor includes an inorganic compound where an AlON crystal, an AlON solid solution crystal, or an inorganic crystal having a crystal structure identical to AlON includes at least Mn, an A element (a monovalent metal element) it necessary, a D element (a divalent metal element) if necessary, an E element (a monovalent anion) if necessary, and a G element (one or more elements other than Mn, the A, Al, O, N, the D, or the E) if necessary, and emits fluorescence having a peak wavelength from 515 nm to 541 nm upon irradiation of an excitation source.

A method for producing a rare earth aluminate sintered body includes: preparing a molded body by mixing a fluorescent material having a composition of a rare earth aluminate and a raw material mixture comprising an oxide containing at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd, and Tb, an oxide containing Ce, an oxide containing Al, and optionally an oxide containing at least one element M.sup.1 selected from the group consisting of Ga and Sc; and calcining the molded body to obtain a sintered body.

A light emitting apparatus affording high quality colors and energy economy and an electronic device comprising the light emitting apparatus.

A wavelength conversion element includes a phosphor layer having phosphor particles and a binder, and a holding member including alumina, configured to hold the layer. The binder includes glass and is configured to bind a part the adjacent particles. The holding member has a pore, defining an apparent porosity thereof as X, bending strength A of the holding member fulfills A=7.11X+316.52, an elastic modulus B of the holding member fulfills B=6.26X+288.43, and defining an elastic modulus of the glass as C, 1/B+1/C=D, and a product of a difference between a linear expansion coefficient of the holding member and a linear expansion coefficient of the glass and a transition point of the glass as Y, Y<(A)(D)(0.001) when the linear expansion coefficient of the glass is smaller than the linear expansion coefficient of the holding member in a temperature range from the transition point of the glass to a room temperature.