High efficacy electrodeless high intensity discharge lamp
AssigneeGeneral Electric Company
InventorHarald L. Witting
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Abstract
Improved efficacy and color rendition are achieved in a high intensity discharge, solenoidal electric field (HID-SEF) lamp by using a novel combination of fill ingredients, including lanthanum halide, sodium halide, cerium halide, and xenon or krypton as a buffer gas. The preferred lamp structure is that of a short cylinder having rounded edges in order to achieve isothermal lamp operation and further efficacy improvement.
Claims22
An electrodeless metal halide high intensity discharge lamp, comprising:
- a light transmissive arc tube for containing an arc discharge;
- a fill disposed in said arc tube, said fill including lanthanum halide, sodium halide and cerium halide, said halides being selected from the group consisting of iodides, chlorides and bromides, including mixtures thereof, said halides being combined in weight proportions to generate white color lamp emission exhibiting improved efficacy and color rendition;
- said fill further including a buffer gas selected from the group consisting of xenon and krypton, said buffer gas being present in sufficient quantity to limit chemical transport of energy from said arc discharge to the walls of said arc tube;
- and
- excitation means for coupling radio frequency energy to said fill.
In an electrodeless metal halide high intensity discharge lamp having an arc tube for containing an arc discharge, an arc tube fill substantially free of mercury comprising:
- lanthanum halide, sodium halide and cerium halide, said halides being selected from the group consisting of iodides, chlorides and bromides, including mixtures thereof, said halides being combined in weight proportions to generate white color lamp emission exhibiting improved efficacy and color rendition;
- and
- a buffer gas selected from the group consisting of xenon and krypton, said buffer gas being present in sufficient quantity to limit chemical transport of energy from said arc discharge to the walls of said arc tube.
Dependencies are inferred from the claim text.