Blue-enriched incandescent lamp
View Patent ↗A blue-enriched incandescent lamp having on the interior surface of its light transmissive glass envelope a coating in accordance with an aspect of the invention. The coating contains a phosphor that is energized by the ultraviolet/violet emission (<420 nm) from the hot filament causing it to emit radiation in the range of 420 to 490 nm. In a preferred embodiment of the invention, the coating contains a europium-activated barium magnesium aluminate phosphor and a blue pigment.
1. A blue-enriched incandescent lamp comprising:
a light transmissive envelope;
a filament within said envelope, the filament producing at least an emission having a wavelength less than 420 nm when operating; and
a coating on the interior surface of said envelope, said coating containing a phosphor having a general formula BaMgAl 10 O 17 : Eu that emits radiation in the range of 420 to 490 nm when stimulated by the emission from the filament.
2. The blue-enriched incandescent lamp of claim 1 wherein said coating further contains a blue pigment.
3. The blue-enriched incandescent lamp of claim 1 wherein said coating includes about 2 weight percent cobalt aluminate.
4. The blue-enriched incandescent lamp of claim 1 wherein said emitted radiation from the phosphor has a maximum at about 450 nm.