| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce variation in color temperatures of light in a light-emitting device using a light-emitting element and a phosphor which is exited to emit light by outgoing radiation of light from the light-emitting element. <P>SOLUTION: A light-emitting device 1 comprises a light-emitting element 3, a first phosphor 5 which is exited to emit light by the light radiated from the light-emitting element 3, and a second phosphor 7 which is exited to emit light by the light radiated from the light-emitting element 3 or the light radiated from the first phosphor 5. The inclination θ<SB POS="POST">1</SB>of a straight line L<SB POS="POST">1</SB>on a chromaticity diagram linking a chromaticity coordinate Y of the light radiated from the first phosphor 5 and a chromaticity coordinate B of the light radiated from the light-emitting element 3 is made equal to the inclination θ<SB POS="POST">2</SB>of an isochromatic temperature line L<SB POS="POST">2</SB>of light which has had a designated color temperature obtained by mixing the light radiated from the light-emitting element 3, the light radiated from the first phosphor 5, and the light radiated from the second phosphor 7 together. Thus, since a variation in chromaticity coordinates of the light radiated from the light-emitting device 1 occurs along the isochromatic temperature line L<SB POS="POST">2</SB>, a variation in color temperatures is reduced. <P>COPYRIGHT: (C)2012,JPO&INPIT |
