| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device with improved brightness feeling under twilight viewing environments, and capable of improving color rendering properties while restraining a melatonin inhibitory action toward a living body and light-trap properties.SOLUTION: A blue-color LED element is structured to have a half-value width narrower than 50 nm with a first peak wavelength P1 in a range of 440 nm to 480 nm. A phosphor is structured to have a second peak wavelength P2 in a blue-green-color wavelength band longer than 505 nm and a half-value width narrower than 50 nm, and to have a third peak wavelength P3 in a tangerine wavelength band in a range of 610 nm to 650 nm with a half-value width in a range of 80 nm to 200 nm. The phosphor is so structured to have light emission intensity of the second peak wavelength P2 smaller than 6 times that of the first peak wavelength P1 and smaller than 3 times that of the third peak wavelength P3. Further, the phosphor is so structured to have light emission intensity of the third peak wavelength P3 smaller than 3 times that of the first peak wavelength P1. |
