A high color rendering fluorescent lamp having two-layered phosphor coating, wherein a first layer is formed immediately on the inner face of glass tube containing phosphors of alkaline earth halophosphate activated by antimony manganese or of alkaline earth holophosphate activated by antimony or both,...http://www.google.es/patents/US4705986?utm_source=gb-gplus-sharePatente US4705986 - High color rendering fluorescent lamp
