| abstract |
Provided is a white light source, comprising a light emitting diode with a peak wavelength of 350nm-420nm, and a fluorescent light body layer further comprising four or more types of fluorescent light bodies with different peak wavelengths and a resin. With the emission spectrum of the white light source designated P(λ), the emission spectrum of black body radiation which denotes a color temperature which is the same as that of the white light source designated B(λ), the spectrum of the spectral luminous efficiency designated V(λ), the wavelength at which P(λ) x V(λ) is at a maximum designated λmax1, and the wavelength at which B(λ) x V(λ) is at a maximum designated λmax2, the relational formula -0.2≤[(P(λ) x V(λ))/(P(λmax1) x V(λmax1))-(B(λ) x V(λ))/(B(λmax2) x V(λmax2))]≤+0.2 is satisfied, and the size of the color change between the initial lighting of a white light source which uses a CIE chromaticity diagram and after 6000 hours of consecutive lighting is less than 0.010. Additionally, it would be permissible for the mass ratio of the fluorescent light bodies in the fluorescent light body layer to be 60mass%-90mass%. It is possible, with this configuration, to provide a white light source which has high long-term reliability, with which natural light is reproduced, and color change is alleviated. |