Image Number 2 for United States Patent #4070598.
A fluorescent lamp having a phosphor layer for converting radiation at a first non-visible wavelength to radiation in the visible spectrum, includes a second phosphor layer for converting other non-visible radiation, having a deleterious effect (depreciation) on the first phosphor layer, to wavelengths in the region containing the first wavelength for subsequent conversion to visible light, thus increasing the brightness of the fluorescent lamp simultaneous with minimization of early depreciation of lamp brightness.
|
