Fluorescent lamp having a multi-layer phosphor optimized for lumen output, color rendering and cost

摘要

In a fluorescent lamp having a multi-layer phosphor, a halophosphate-containing layer having color coordinates within an oval centered on X=0.382 and Y=0.384. A rare earth activated phosphor layer has approximately the same color coordinates. The area density ratio of the rare earth and halophosphate-containing phosphor layers is between 0.088 to 0.222 and preferably between 0.088 to 0.133.