Abstract: A light emitting device according to one embodiment includes: a board; plural first light emitting units each including a first light emitting element and a first fluorescent layer formed on the first light emitting element having a green phosphor; plural second light emitting units each including a second light emitting element and a second fluorescent layer formed on the second light emitting element having a red phosphor; the second fluorescent layers and the first fluorescent layers being separated in a non-contact manner with gas interposed there between; and plural third light emitting units each including a third light emitting element and a resin layer formed on the third light emitting element having neither a green phosphor nor the red phosphor, the third light emitting units being disposed between the first light emitting units and the second light emitting units.

Abstract: A light emitting device according to one embodiment includes a board; plural first light emitting elements mounted on the board to emit light having a wavelength of 250 nm to 500 nm; plural second light emitting elements mounted on the board to emit light having a wavelength of 250 nm to 500 nm; a first fluorescent layer formed on each of the first light emitting elements, the first fluorescent layer including a first phosphor; and a second fluorescent layer formed on each of the second light emitting elements, the second fluorescent layer including a second phosphor. The second phosphor is higher than the first phosphor in luminous efficiency at 50° C., and is lower than the first phosphor in the luminous efficiency at 150° C.

Abstract: The embodiment provides a process for production of an oxynitride fluorescent substance. In the process, a compound represented by the formula: (Sr,Eu)2Si5N8, silicon nitride and aluminum nitride are mixed and then fired in a nitrogen atmosphere under high pressure.

Abstract: A semiconductor light-emitting device includes a semiconductor light-emitting element emitting light in a region ranging from ultraviolet to visible, and a visible-light luminescent element absorbing light emitted from the semiconductor light-emitting element and outputting visible light. The visible-light luminescent element includes a substrate, a light-reflecting layer formed on the substrate and containing light scattering particles, and a luminescent layer containing phosphor particles. The luminescent layer absorbs light emitted from the semiconductor light-emitting element and output visible light. The luminescent layer further absorbs light that is emitted from the semiconductor light-emitting element, arrives at and is reflected from the light scattering particles, and output the visible light.

Abstract: A light emitting device according to one embodiment includes a light emitting element that emits light having a wavelength of 250 nm to 500 nm and a fluorescent layer that is disposed on the light emitting element. The fluorescent layer includes a phosphor having a composition expressed by the following equation (1) and an average particle diameter of 12 ?m or more. (M1?x1Eux1)3?ySi13?zAl3+zO2+uN21?w??(1) (In the equation (1), M is an element that is selected from IA group elements, IIA group elements, IIIA group elements, IIIB group elements except Al, rare-earth elements, and IVB group elements. x1, y, z, u, and w satisfy the following relationship. 0<x1<1, ?0.1<y<0.3, ?3<z?1, ?3<u?w?1.

Abstract: A light emitting device according to one embodiment includes a light emitting element that emits light having a wavelength of 250 nm to 500 nm and a fluorescent layer that is disposed on the light emitting element. The fluorescent layer includes a phosphor having a composition expressed by the following equation (1) and an average particle diameter of 12 ?m or more. (M1?x1Eux1)3?ySi13?zAl3+zO2+uN21?w??(1) (In the equation (1), M is an element that is selected from IA group elements, IIA group elements, IIIA group elements, IIIB group elements except Al, rare-earth elements, and IVB group elements. x1, y, z, u, and w satisfy the following relationship. 0<x1?1, ?0.1?y?0.15, ?1?z?1, ?1<u?w?1.

Abstract: The present invention provides a fluorescent substance excellent both in quantum efficiency and in temperature characteristics, and also provides a process for producing the fluorescent substance. This fluorescent substance is an oxynitride phosphor having a low paramagnetic defect density and comprising aluminum, silicon, either or both of oxygen and nitrogen, and a metal element M, provided that the metal element M is partly replaced with an emission center element R. That phosphor can be produced by the steps of: subjecting a mixture of starting materials to heat treatment under a nitrogen atmosphere so as to obtain an intermediate fired product, and then further subjecting the intermediate fired product to heat treatment under an atmosphere of nitrogen-hydrogen mixed gas.

Abstract: A luminescent material is provided, which includes a carbide oxynitride-based compound having a composition represented by formula 1: (M1?wRw)uAl1?xSi1+vOzNtCy??formula 1 wherein M is at least one metal element excluding Si and Al, and R is a luminescent central element. w, u, x, v, z, t and y satisfy following relationships: 0.001<w<0.5; 0.66?u?1; 0.07?x?0.73; 0.06?v?0.84; 0.04?z?0.44; 2.7?t?3.1; and 0.019?y?0.13.

Abstract: Disclosed is a white light emitting device including a semiconductor light emitting element configured to emit near ultraviolet light having a peak wavelength ranging from 380 to 410 nm, a first phosphor layer and a second phosphor layer. The first phosphor layer contains a blue-emitting phosphor configured to emit blue light by the near ultraviolet light, and a red-emitting phosphor activated by trivalent europium and configured to emit red light by the near ultraviolet light. The second phosphor layer contains a green-emitting phosphor configured to emit green light by the near ultraviolet light. The semiconductor light emitting element, the first phosphor layer and the second phosphor layer are laminated in this order to emit white light.

Abstract: The embodiment provides a process for production of an oxynitride fluorescent substance. An compound containing In or Ga is adopted in the process as a material thereof. The red fluorescent substance produced by the process can be combined with a semiconductor light-emitting element, so as to be used in a light-emitting device or a light-emitting module.

Abstract: The embodiment provides a process for production of a green light-emitting oxynitride fluorescent material having Sr3Al3Si13O2N21 crystal structure, and also provides the fluorescent material produced by that process. An metal halide is adopted in the process as one of the starting material metal compounds. As the metal halide, a Ca or Na compound as well as a Sr compound can be preferably employed.

Abstract: The present invention provides a red-emitting phosphor emitting luminescence of excellent color purity with high efficiency under the excitation with near UV light, and it also provides a color image displaying device employing that phosphor. This phosphor comprises an ARS2 matrix (A is at least one of Na, K and Rb, and R is at least one of Y, Gd and Lu) doped with 0.003 to 0.3 mol % of Bi and 0.1 to 3 mol % of Mn, and is suitable as a red-emitting phosphor used in a color image displaying device without a color filter.

Abstract: It is made possible to provide a light-emitting material having a short decay time of 10 ?s or less and an emission wavelength of 650 nm or longer. A light-emitting material includes a material having a composition represented by ARS2:Eu, wherein A represents at least one element selected from Na, K, Rb, and Cs, and R represents at least one element selected from Y, La, Gd, and Lu.

Abstract: The present invention provides a red fluorescent substance and a light-emitting device utilizing the substance. This device less suffers from color drift even when working with high power. The light-emitting device comprises a blue LED, a green fluorescent substance of Sr3Al3Si13O2N21 activated with a luminescent center, and the red fluorescent substance. The red fluorescent substance contains an inorganic compound comprising a metal element M, a trivalent element M1 other than the M, a tetravalent element M2 other than the M, and nitrogen element. In the inorganic compound, the M is partly replaced with a luminescent center element EC. The red fluorescent substance has basically the same crystal structure as Sr2Al3Si7ON13. The red fluorescent substance emits luminescence having a peak in the range of 580 to 650 nm when excited with light of 250 to 500 nm.

Abstract: A semiconductor light-emitting device includes a semiconductor light-emitting element emitting light in a region ranging from ultraviolet to visible, and a visible-light luminescent element absorbing light emitted from the semiconductor light-emitting element and outputting visible light. The visible-light luminescent element includes a substrate, a light-reflecting layer formed on the substrate and containing light scattering particles, and a luminescent layer containing phosphor particles. The luminescent layer absorbs light emitted from the semiconductor light-emitting element and output visible light. The luminescent layer further absorbs light that is emitted from the semiconductor light-emitting element, arrives at and is reflected from the light scattering particles, and output the visible light.

Abstract: A fluorescent substance is provided, with includes a matrix composed of a compound having an AlN polytypoid structure represented by the following general formula (1), and a luminescence center element: (Al,M)a(N,X)b??(1) wherein, M is at least one metal excluding Al, X is at least one non-metal excluding N, and a and b are positive values.

Abstract: A lithium calcium silicate luminescent material is provided, which includes a tetragonal crystal phase containing Li, Ca, Si and O, and an activator containing Eu. The luminescent material exhibits a peak wavelength of emission spectrum falling within a wavelength region of 470 to 490 nm when excited by light having an emission peak falling within a wavelength region of 360 to 460 nm.

Abstract: A luminescent material is provided, which includes a carbide oxynitride-based compound having a composition represented by formula 1: (M1?wRw)uAl1?xSi1+vOzNtCy??formula 1 wherein M is at least one metal element excluding Si and Al, and R is a luminescent central element. w, u, x, v, z, t and y satisfy following relationships: 0.001<w<0.5; 0.66?u?1; 0.07?x?0.73; 0.06?v?0.84; 0.04?z?0.44; 2.7?t?3.1; and 0.019?y?0.13.

Abstract: An image display device is provided, which includes a first substrate having a cold-cathode electron-emission element which emits electrons, and a second substrate which is spaced from and opposed to the first substrate. The second substrate has a transparent substrate, a light-emitting layer provided on the transparent substrate and including phosphor particles containing zinc sulfide as a base material, a boron nitride film disposed on a surface of the light-emitting layer, and an anode applying a voltage to the light-emitting layer.

Abstract: It is made possible to provide a light-emitting material having a short decay time of 10 ?s or less and an emission wavelength of 650 nm or longer. A light-emitting material includes a material having a composition represented by ARS2:Eu, wherein A represents at least one element selected from Na, K, Rb, and Cs, and R represents at least one element selected from Y, La, Gd, and Lu.