A mercury vapor discharge lamp having a barrier layer and a single phosphor layer. The phosphor layer comprises 10–50 weight percent halophosphors and 50–90 weight percent rare earth phosphors. The lamp has an Ra value of 70–81, more preferably 70–79, more preferably 75–79....http://www.google.es/patents/US6992432?utm_source=gb-gplus-sharePatente US6992432 - Fluorescent lamp
