Patent ID: 9082939
Filing Date: 2015-07-14
Classification: C09K,F21K,H01L,Y02B

Abstract:
1. A white light source comprising: a light emitting diode having a light emission peak wavelength in a range of 350 nm 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(λ)×V(λ))/(P(λmax 1 )×V(λmax 1 ))−(B(λ)×V(λ))/(B(λmax 2 )×V(λmax 2 ))]≦+0.2, assuming that: a light emission spectrum of the white light source is P(λ); a light emission spectrum of black-body radiation having a same color temperature as that of the white light source is B(λ); a spectrum of a spectral luminous efficiency is V(λ); a wavelength at which P(λ)×V((λ) becomes largest is λmax 1 ; and a wavelength at which B(λ)×V(λ) becomes largest is λmax 2 , and wherein an amount 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.