Light-emitting device, white light-emitting device, illuminator, and image display

摘要

To achieve a light-emitting device emitting light with high brightness, closer to natural light, and less color shift due to a small change in intensity of emitted light, in a light-emitting device including a light source emitting light by driving current and at least one wavelength-converting material absorbing at least part of the light from the light source and emitting light having a different wavelength, the color coordinate x1(17.5) and the color coordinate y1(17.5) of the light emitted at a driving current density of 17.5 A/cm2 and the color coordinate x1(70) and the color coordinate y1(70) of the light emitted at a driving current density of 70 A/cm2 satisfy the following Expressions (D) and (E):
−0.006≦x1(17.5)−x1(70)≦0.006  (D),−0.006≦y1(17.5)−y1(70)≦0.006  (E).

主权项

1. A white light emitting device comprising:
a light source configured to emit light; and at least one wavelength converting-material configured to absorb at least a part of the light emitted from the light source and configured to emit light having different wavelengths, wherein the white-light emitting device emits white light comprising the light emitted by the wavelength-converting material, a maximum intensity of an emission spectrum of the white light at a wavelength range of 500 nm to 650 nm is not higher than 150% of a minimum intensity in the wavelength range, and said wavelength converting-material comprises at least one green phosphor and comprises at least one red phosphor represented by formula (3):
MaAbDcEdXe  (3)where M is one or more elements selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm and Yb; A represents one or two elements selected from the group consisting of divalent metallic elements other than the M; D represents one or more elements selected from the group consisting of quadrivalent metallic elements; E represents one or more elements selected from the group consisting of trivalent metallic elements; X represents one or more elements selected from the group consisting of 0, N, and F; and a, b, c, d, and e are numbers satisfying:
0.00001≦a≦0.1, a+b=1, 0.5≦c≦4, 0.5≦d≦8, 0.8×(⅔+ 4/3×c+d)≦e, and e≦1.2×(⅔+ 4/3×c+d).