Regenerative-cycle incandescent lamp containing SnI{HD 4 {B additive

摘要

The quality and useful life of regenerative-cycle type incandescent lamps that employ iodine as the halogen are enhanced by dosing the lamps with a carefully controlled amount of SnI4 which decomposes when the lamp filament is energized and provides from about 0.05 to 0.20 micromole of vaporized elemental iodine per ml. of bulb volume within the lamp during operation. The resulting increase in the amount of iodine that is converted into atomic rather than molecular form within the energized lamp permits elongated iodine-cycle lamps having singly-coiled filaments to be operated in any position in contrast to conventional iodine-cycle lamps of the same configuration and construction that exhibit early blackening of the top portion of the envelope when the lamp is operated in a vertical position. The undesirable light-absorption and color distortion effects characteristic of conventional iodine-dosed lamps are also reduced, thus increasing the lamp efficiency.