To minimize the variability in the emitted light color and improve the unevenness of color tone, a light emitting device comprises a light emitting element and a fluorescent substance that is excited by the light emitting element, wherein the light emitting element has an emission spectrum in a region...http://www.google.fr/patents/US7091656?utm_source=gb-gplus-shareBrevet US7091656 - Light emitting device
