Luminaire

Abstract

A luminaire includes a semiconductor light source having a light emission peak in a range of wavelength smaller than 480 nm and a phosphor excited by light radiated from the semiconductor light source to radiate light having wavelength equal to or larger than 480 nm. A spectrum of radiated light obtained by combining the light radiated from the semiconductor light source and the light radiated from the phosphor has a light emission peak in a range of wavelength equal to or larger than 610 nm and smaller than 650 nm. A ratio of radiation energy in a range of wavelength equal to or larger than 650 nm and equal to or smaller than 780 nm to radiation energy in a range of wavelength equal to or larger than 600 nm and smaller than 650 nm is equal to or lower than 35%. A color gamut area ratio exceeds 100%.

What is claimed is: 
     
         1 . A luminaire comprising:
 a semiconductor light source having a light emission peak in a range of wavelength smaller than 480 nm; and   a phosphor excited by light radiated from the semiconductor light source to radiate light having wavelength equal to or larger than 480 nm,   wherein the phosphor includes a first phosphor excited by light radiated from the semiconductor light source to radiate light having an emission spectrum that includes an emission peak in a wavelength range equal to or larger than 610 nm and smaller than 650 nm, and the emission peak has a half width smaller than 20 nm, and   wherein output light obtained by combining the light radiated from the semiconductor light source and the light radiated from the phosphor has a color gamut area ratio that exceeds 100%.   
     
     
         2 . The luminaire according to  claim 1 , wherein the first phosphor further includes a second phosphor having a light emission peak in a wavelength range equal to or larger than 540 nm and equal to or smaller than 580 nm, and a third phosphor having a light emission peak in a wavelength range equal to or larger than 480 nm and smaller than 540 nm. 
     
     
         3 . The luminaire according to  claim 1 , wherein the phosphor further includes a second phosphor having a light emission peak in a wavelength range equal to or larger than 540 nm and equal to or smaller than 580 nm. 
     
     
         4 . The luminaire according to  claim 3 , wherein a ratio of radiation energy in the wavelength range equal to or larger than 650 nm and equal to or smaller than 780 nm to radiation energy in the wavelength range equal to or larger than 600 nm and smaller than 650 nm is equal to or lower than 10%. 
     
     
         5 . The luminaire according to  claim 3 , wherein a ratio of light emission intensity at light wavelength of 650 nm to intensity at the light emission peak in the wavelength range equal to or larger than 610 nm and smaller than 650 nm is smaller than 0.29. 
     
     
         6 . The luminaire according to  claim 2 , wherein
 correlated color temperature of the output light obtained by combining the light radiated from the semiconductor light source and the light radiated from the phosphor is equal to or lower than 3000 kelvin, and   weight of the first phosphor is three times or more as large as weight of the second phosphor.   
     
     
         7 . The luminaire according to  claim 1 , wherein
 the first phosphor has at least a pair of the light emission peaks in the wavelength range equal to or larger than 610 nm and smaller than 650 nm, and   fluctuation in the light emission peak on a short wavelength side due to temperature is smaller than fluctuation in the light emission peak on a long wavelength side due to temperature.   
     
     
         8 . The luminaire according to  claim 1 , further comprising:
 a substrate mounted with the semiconductor light source; and   transparent resin provided on the substrate and including the phosphor.   
     
     
         9 . The luminaire according to  claim 8 , wherein the transparent resin includes:
 first transparent resin formed to seal the semiconductor light source on the substrate and containing a member that scatters radiated light of the semiconductor light source; and   second transparent resin provided on the first transparent resin and containing the phosphor.   
     
     
         10 . The luminaire according to  claim 8 , wherein
 the phosphor further includes a second phosphor having a light emission peak in a wavelength range equal to or larger than 540 nm and equal to or smaller than 580 nm, wherein   the transparent resin includes:
 first transparent resin formed to seal the semiconductor light source and containing the second phosphor; and 
 second transparent resin provided on the first transparent resin and containing the first phosphor. 
   
     
     
         11 . The luminaire according to  claim 10 , wherein the first transparent resin includes a main component which is the same as a main component of the second transparent resin. 
     
     
         12 . The luminaire according to  claim 8 , wherein
 the phosphor further includes a second phosphor having a light emission peak in a wavelength range equal to or larger than 540 nm and equal to or smaller than 580 nm, and a third phosphor having a light emission peak in a range of wavelength equal to or larger than 480 nm and smaller than 540 nm,   wherein the transparent resin includes resin containing the first phosphor, resin containing the second phosphor, and resin containing the third phosphor.   
     
     
         13 . The luminaire according to  claim 12 , wherein the first phosphor, the second phosphor, and the third phosphor are arranged from a substrate side in order from the one having a smallest change in light emission intensity due to temperature. 
     
     
         14 . The luminaire according to  claim 1 , wherein the first phosphor contains a fluoride phosphor having a light emission peak in a range of wavelength equal to or larger than 610 nm and smaller than 650 nm.