LOW-PRESSURE MERCURY VAPOUR DISCHARGE LAMP

摘要

Low-pressure mercury vapour discharge lamp. Low-pressure mercury vapour discharge lamp having a very satisfactory colour rendition and a colour temperature from 2300 to 3300 K. The lamp is provided with a luminescent layer comprising : a a luminescent alkaline earth metal halophosphate activated by Sb3+ and Mn2+ and having a colour temperature of 2900 - 5000 K; b a luminescent material activated by Eu2+ and having an emission maximum of 470 - 500 nm; c a luminescent rare earth metal metaborate activated by Ce3+ and Mn2+ and having a red Mn2+ emission, and d a luminescent aluminate activated by Ce3+ and having a garnet crystal structure absorbing blue radiation below 480 nm. Furthermore the luminescent layer comprises: e a green luminescing Mn2+ activated material having an emission maximum in the range from 510 to 535 nm. As a result of the addition of the material e the quantity of the material d can be limited so that colour point differences among the lamps are avoided. Figure.