| 摘要 |
The present invention provides a white light source comprising: a light emitting diode (LED) having a light emission peak wavelength in a range of 350 or more and 420 nm or less; and a phosphor layer including four or more types of phosphors and resin, wherein the white light source satisfies a relational equation of: -0.2 ‰¤ [(P(») × V(»)) / (P(»max1) × V(»max1)) - (B(») × V(»)) / (B(»max2) × V(»max2))] ‰¤ +0.2, assuming that: a light emission spectrum of the white light source is P(»); a light emission spectrum of black-body radiation having a same color temperature as that of the white light source is B(»); a spectrum of a spectral luminous efficiency is V(»); a wavelength at which P(») × V(») becomes largest is »max1; and a wavelength at which B(») × V(») becomes largest is »max2, and wherein an amount (difference) of chromaticity change on CIE chromaticity diagram from a time of initial lighting up of the white light source to a time after the white light source is continuously lighted up for 6000 hours is less than 0.010. According to the above white light source, there can be provided a white light source capable of reproducing the same light emission spectrum as that of natural light. |
