C09K11/77348

Light emitting device emitting light bright in both scotopic vision and photipic vision

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:
(Lu.sub.1-p-nLn.sub.pCe.sub.n).sub.3(Al.sub.1-mGa.sub.m).sub.5kO.sub.12  (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.

(Oxy)nitride phosphor powder and method of producing same

An (oxy)nitride phosphor powder has a fluorescence peak wavelength of 610 to 625 nm and also has higher external quantum efficiency than the conventional one. The (oxy)nitride phosphor powder includes an α-type SiAlON and aluminum nitride, represented by the compositional formula: Ca.sub.x1Eu.sub.x2Si.sub.12−(y+z)Al.sub.(y+z)O.sub.zN.sub.16−z wherein x1, x2, y, z fulfill the following formulae: 1.60≦x1+x2≦2.90, 0.18≦x2/x1≦0.70, 4.0≦y≦6.5, 0.0≦z≦1.0. The powder can additionally contain Li in an amount of 50 to 10000 ppm. The content of the aluminum nitride may be more than 0 mass % to less than 33 mass %.

Phosphor, production method for same, light-emitting device, image display device, pigment, and ultraviolet absorber

A phosphor having different light emission characteristics from the conventional phosphor, having high emission intensity and chemical and thermal stability, combined with LED of less than 450 nm. This phosphor includes an inorganic compound comprising: a crystal represented by Ba.sub.1Si.sub.4Al.sub.3N.sub.9, an inorganic crystal having the same crystal structure as Ba.sub.1Si.sub.4Al.sub.3N.sub.9 crystal, or a solid solution crystal thereof, comprising A element, D element, E element, and X element (A is one or more elements selected from Li, Mg, Ca, Sr, Ba, and La; D is one or more elements selected from Si, Ge, Sn, Ti, Zr, and Hf; E is one or more elements selected from B, Al, Ga, In, Sc, and Y; X is one or more elements selected from O, N, and F), into which M element is solid-solved (M is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb).

FLUORESCENT COMPOSITION, A LIGHT EMITTING ELEMENT PACKAGE COMPRISING SAME, AND AN ILLUMINATING DEVICE

A phosphor composition of an embodiment and a light emitting device package including the same includes: a green phosphor excited by blue light to emit green light; a first red phosphor of a nitride series which is excited by the blue light and emits first red light; and a second red phosphor of a fluorine series which is excited by the blue light and emits second red light, and is capable of emitting white light without deterioration of optical characteristics at a high temperature while improving luminous flux and color reproduction rate as compared with a light emitting device package including a conventional phosphor composition.

Light emitting device
11667836 · 2023-06-06 · ·

A light emitting device includes a first light source containing a first light emitting element, and a second light source containing a second light emitting element and a second fluorescent material, the first light source emits light in a region that is demarcated in a chromaticity diagram of the CIE 1931 color coordinate system by a first straight line connecting a first point having x,y of 0.280, 0.070 in the chromaticity coordinate and a second point having x,y of 0.280, 0.500 in the chromaticity coordinate, a second straight line connecting the second point and a third point having x,y of 0.013, 0.500 in the chromaticity coordinate, a purple boundary extending from the first point toward a direction in which x decreases in the chromaticity coordinate, and a spectrum locus extending from the third point toward a direction in which y decreases in the chromaticity coordinate, in a light emission spectrum, a light emission intensity ratio I.sub.PM/I.sub.PL of a light emission intensity I.sub.PM at a wavelength of 490 nm with respect to a light emission intensity I.sub.PL at a maximum light emission peak wavelength of the first light emitting element is in a range of 0.22 or more and 0.95 or less, the second light source emits light having a color deviation duv from a blackbody radiation locus in a range of −0.02 or more and 0.02 or less measured according to JIS Z8725 with a correlated color temperature in a range of 1,500 K or more and 8,000 K or less in a chromaticity diagram of the CIE 1931 color coordinate system, and the light emitting device emits mixed color light of light emitted from the first light source and light emitted from the second light source.

OXIDE FLUORESCENT MATERIAL AND LIGHT EMITTING DEVICE
20230167358 · 2023-06-01 · ·

To provide an oxide fluorescent material that has a light emission peak wavelength in a wavelength range of from red light to near infrared light. The oxide fluorescent material has a composition encompassed in a compositional formula represented by the following formula (1):


(Li.sub.1-tM.sup.1.sub.t).sub.u(Ga.sub.1-vM.sup.2.sub.v).sub.5O.sub.w:Cr.sub.x,Ni.sub.y,M.sup.3.sub.z,  (1)

wherein in the formula (1), M.sup.1 represents at least one kind of an element selected from the group consisting of Na, K, Rb, and Cs; M.sup.2 represents at least one kind of an element selected from the group consisting of B, Al, Sc, In, and a rare earth element; M.sup.3 represents at least one kind of an element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta; and t, u, v, w, x, y, and z each satisfy 0≤t≤1.0, 0.7≤u≤1.6, 0≤v<1.0, 7.85≤w≤11.5, 0.05≤x≤1.2, 0≤y≤0.5, 0.25<x+y≤1.2, y<x, and 0≤z≤0.5.

LED PHOSPHOR COMPRISING BOW-TIE SHAPED A2N6 BUILDING BLOCKS

The invention provides, amongst others for application in a lighting unit, a phosphor selected from the class of


M.sub.2D.sub.2C.sub.2-2bB.sub.bA.sub.2N.sub.6:Ln   (I)

with M=selected from the group consisting of divalent Ca, Sr, and Ba; D=selected from the group consisting of monovalent Li, divalent Mg, Mn, Zn, Cd, and trivalent Al and Ga; C=selected from the group consisting of monovalent Li and Cu; B=selected from the group consisting of divalent Mg, Zn, Mn and Cd; A=selected from the group consisting of tetravalent Si, Ge, Ti, and Hf; Ln=selected from the group consisting of ES and RE; ES=selected from the group consisting of divalent Eu, Sm and Yb; RE=selected from the group consisting of trivalent Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Tm; and 0≦b≦1.

PHOSPHOR AND LIGHT-EMITTING EQUIPMENT USING PHOSPHOR

Phosphors include a CaAlSiN.sub.3 family crystal phase, wherein the CaAlSiN.sub.3 family crystal phase comprises at least one element selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb.

LIQUID CRYSTAL DISPLAY APPARATUS

A liquid crystal display device includes: a liquid crystal display panel that includes red color filters, green color filters, and blue color filters; and an illumination device that illuminates the liquid crystal display panel with white light. The illumination device includes light-emitting elements that emit blue light, a green phosphor that absorbs a portion of the blue light emitted from the light-emitting elements and then emits green light, and a red phosphor that absorbs a portion of the blue light emitted from the light-emitting elements and then emits red light. The blue color filters are made of a colored material that contains a dye, and the chromaticity values x and y of the white light emitted from the illumination device satisfy the relationships 0.24<x and 0.24<y.

Phosphor particle, composite, light-emitting device, and method for producing phosphor particle

An α-sialon phosphor particle containing Eu. At least one minute recess is formed on a surface of the α-sialon phosphor particle. The α-sialon phosphor particle is preferably produced by undergoing a raw material mixing step, a heating step, a pulverizing step, and an acid treatment step.