Patent ID: 9551467
Date: 2017-01-24
CPC Classifications: C09K,F21K,F21V,F21Y,H01L,Y02B

Claim:
1. A white light source comprising: a blue light emitting diode having a light emission peak wavelength in a range of 421 to 490 nm; and a phosphor layer including phosphor and resin, wherein the phosphor layer contains three or more types of phosphor selected from among a blue phosphor, a blue-green phosphor, a green phosphor, a yellow phosphor, and a red phosphor, and a mass ratio of the phosphor included in the phosphor layer is 5 mass % or more and 50 mass % or less, wherein the white light source satisfies a relational equation of −0.2≦[(P(λ)×V(λ))/ (P(λmax1)×V(λmax1))−(B(λ)×V(λ))/(B(λmax2)×V(λmax2))]≦+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 λmax1; and a wavelength at which B(λ)×V(λ) becomes largest is λmax2, 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.