Fluorescent lamp with sharp emission peaks betwen 480 and 490 nm and between 620 and 640 nm

摘要

A fluorescent lamp having excellent color rendering property and high luminous efficiency comprises a fluorescent layer coated on an inner surface of a discharge tube.PPThe fluorescent layer mainly comprises a first fluorescent material having-emission peak in a range of wavelength of 480 to 490 nm which is an alkaline earth metal boron phosphate activated by a divalent europium compound having the formula ##EQU1## wherein the parameters x, y, p, m and n are in ranges of 0≦x≦0.5PP0≦y≦0.2P P 0.001≦ p≦0.15PP1.75≦m≦2. 30 andPP 0. 05≦n≦0.23PPand a second fluorescent material having the emission peak in a range of wavelength of 620 to 649 nm and a band width (50%) of 120 to 160 nm.