Rare earth phosphor blends for fluorescent lamp using four to five phosphors

摘要

A phosphor blend for a fluorescent lamp having four rare earth phosphors, each of which emits a narrow band of visible light energy in the visible spectrum. The color of the light produced by three of the phosphors is red, blue and green. The fourth phosphor producing light in the blue-green range improves the color rendering index of the visible light output without seriously afflecting the lumen output as compared to a blend in which only the red-blue-green phosphors are used. A fifth rare earth narrow band phosphor capable of producing energy in the ultraviolet A range can be added to the blend when it is desired to simulate various phases of natural daylight. The band of ultraviolet range energy produced can be smoothed by adding to the blend another phosphor capable of producing energy in the Ultraviolet A range.