Electric lamp including oxygen getter

DETAILED DESCRIPTION We claim: 1.
An electric incandescent lamp having a closed envelope, said envelope containing a filament mounted therein; and a gaseous oxygen getter within said envelope, said oxygen getter comprising phosphine.
2.
The lamp of claim 1 wherein said envelope contains a substantial vacuum.
3.
The lamp of claim 1 wherein said envelope includes a substantially inert fill gas.
4.
The lamp of claim 3 wherein said substantially inert fill gas is selected from one or more of the group consisting of nitrogen, neon, argon, krypton and xenon.
5.
The lamp of claims 1, 2, 3 or 4 wherein said envelope contains a sufficient amount of halogen to allow said lamp to function with a tungsten-halogen cycle.




Description:
TECHNICAL FIELD This invention relates to electric lamps.
More particularly, it relates to such lamps of the incandescent variety which include an efficient oxygen getter.
BACKGROUND ART The deleterious effects of oxygen in incandescent lamps is well known.
To counteract these deleterious effects it also has long been known to include within such lamps an oxygen getter; i.
e.
, a material which will preferentially combine with any free oxygen in the lamp.
Among usable getter materials for lamps, the benefits of phosphorous are well known, and many techniques and compounds have been employed in attempts to incorporate phosphorous into electric lamps.
For example, U.
S.
Pat.
No.
3,475,072 suggests the use of triphosphorous penta-nitride (P.
sub.
3 N.
sub.
5) in solid or slurry forms.
U.
S.
Pat.
No.
4,032,808 suggests the use of phosphorthionitride (PNS) which is to be mixed with a hydrocarbon solvent such as toluene.
The mixture is applied to the filament or the supports therefor as a coating.
These methods require additional steps to include the phosphorous within the lamp and add to the cost thereof.
It would be a decided advance in the art to provide an improved system for incorporating a getter within a lamp.
DISCLOSURE OF THE INVENTION It is, therefore, an object of this invention to obviate the disadvantages of the prior art