White light source and white light source system including the same
View Patent ↗The present invention provides a white light source comprising a blue light emitting LED having a light emission peak of 421 to 490 nm and satisfying 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. 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.
1. A white light source comprising a blue light emitting LED having a light emission peak of 421 to 490 nm and a phosphor excited by the blue light emitting LED thereby to emit a white light,
wherein the phosphor comprises four or more types of phosphors having different peak wavelengths, and at least one of the phosphor is a blue-green phosphor having a peak wavelength of 480 to 500 nm, and 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.
2. The white light source according to claim 1 , wherein said white light source satisfies a relational equation of:
−0.1≦[( P (λ)× V (λ))/( P (λmax1)× V (λmax1))−( B (λ)× V (λ))/( B (λmax2)× V (λmax2))]≦+0.1.
3. The white light source according to claim 1 , wherein the color temperature of the white light source is 2,500 to 5,400 K.
4. The white light source according to claim 1 , wherein said white light source comprises five or more types of phosphors having different peak wavelengths.
5. The white light source according to claim 1 , wherein adjacent peak wavelengths of the phosphors are different by 150 nm or less.
6. The white light source according to claim 1 , wherein said phosphor forms a phosphor layer in which phosphor particles and resin are mixed.
7. The white light source according to claim 6 , wherein said phosphor layer has a multi-layered structure in which a plurality of phosphor elements formed by dispersing phosphor particles in a resin are laminated.
8. The white light source according to claim 1 , comprising, wherein a plurality of the white light sources each having different light emission spectrum, wherein a plurality of blue light emitting LEDs are arranged within one housing, and
wherein each of the white light sources satisfies the relational equation of
−0.2≦[( P (λ)× V (λ))/( P (λmax1)× V (λmax1))−( B (λ)× V (λ))/( B (λmax2)× V (λmax2))]≦+0.2.
9. A white light source system comprising a plurality of the white light sources according to claim 1 .
10. A white light source system comprising a plurality of the white light sources according to claim 5 .