Abstract: To present a green- to yellow-emitting phosphor whereby a light-emitting device having high color rendering properties and high luminance can be obtained, a light-emitting device employing such a phosphor, and an image display device and a lighting system, containing such a light-emitting device. A phosphor made of a compound represented by the following formula (I), which comprises, as matrix, a compound of a garnet structure and which contains, as a luminescent center ion, a metal element in the matrix: M1aM2bXcM3dM43Oe??(I) wherein M1 is Mg and/or Zn, M2 is a bivalent metal element excluding Mg and Zn, X is a metal element as a luminescent center ion composed mainly of Ce, M3 is a trivalent metal element excluding X, M4 is a tetravalent metal element, and a, b, c, d and e are numbers satisfying the following formulae, respectively: 0.001?a?0.5 2.5?b?3.3 0.005?c?0.5 1.5?d?2.3 e={(a+b)×2+(c+d)×3+12}/2.

Abstract: The present invention relates to a phosphor that satisfies requirements (1) to (3): (1) the phosphor satisfies Formula [2] and/or Formula [3]: 85?{R455(125)/R455(25)}×100<110??[2] 92?{R405(100)/R405(25)}×100<110??[3] wherein R455(125) represents an emission peak intensity when the phosphor is excited by light having a peak wavelength of 455 nm at 125° C., (2) the emission peak wavelength is in the range of 570 nm to 680 nm, and (3) the full width at half maximum of an emission peak is 90 nm or less. The phosphor of the present invention has a high luminous efficiency and emits light of orange to red with high luminance. The use of the phosphor makes it possible to produce a light-emitting device, an illumination apparatus, and an image display, having a high efficiency and excellent color rendering properties.

Abstract: To present a green- to yellow-emitting phosphor whereby a light-emitting device having high color rendering properties and high luminance can be obtained, a light-emitting device employing such a phosphor, and an image display device and a lighting system, containing such a light-emitting device. A phosphor made of a compound represented by the following formula (I), which comprises, as matrix, a compound of a garnet structure and which contains, as a luminescent center ion, a metal element in the matrix: M1aM2bXcM3dM43Oe??(I) wherein M1 is Mg and/or Zn, M2 is a bivalent metal element excluding Mg and Zn, X is a metal element as a luminescent center ion composed mainly of Ce, M3 is a trivalent metal element excluding X, M4 is a tetravalent metal element, and a, b, c, d and e are numbers satisfying the following formulae, respectively: 0.001?a?0.5 2.5?b?3.3 0.005?c?0.5 1.5?d?2.3 e={(a+b)×2+(c+d)×3+12}/2.