| 摘要 |
PURPOSE:To obtain a three-wavelength-type high-efficiency high-color-rendering fluorescent lamp having a high luminous flux and a satisfactory color rendering by using a first phosphor consisting of specified components as well as a second and a third phosphor each having an emission peak within a specified wavelength range. CONSTITUTION:A fluorescent lamp is provided with a phosphor 41 consisting of a first phosphor which consists of a halophosphate activated with divalent europium and has an emission peak within the wavelength range of 440-465nm, a second phosphor having an emission peak within the wavelength range of 520- 570nm and a third phosphor having an emission peak within the wavelength range of 600-640nm. The first phosphor is indicated by a general formula M5-xX(PO4)3:EU(x) in which M consists of 4.5-4.95gram atoms of Ba, 0.05- 0.49gram atom of Ca and 0.01-0.3gram atom of Mg, X represents F, Cl, Br or mixture consisting of two or more kinds of these elements and 0.01<x<=0.2. |
