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AssigneeGeneral Electric Company
InventorsTimothy D. Russell, Curtis E. Scott, Charles N. Stewart, Ranajit K. Datta, Mary S. Kaliszewski, Paul G. Mathews
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An arc tube of fused silica for a metal halide arc discharge lamp including a fill for the arc tube comprised of a sodium halide, at least one additional metal halide, and an inert starting gas, the arc tube including a tube of fused silica having an inner wall defining an arc chamber, the inner wall of the tube having provided thereon a metal silicate coating which is vitreous and light-transmissive, and which is comprised of a silicate of at least one metal selected from the group consisting essentially of scandium, yttrium, and a rare earth element, and preferably which is the same metal as that of the at least one additional metal halide. Protection of the fused silica arc tube with the metal silicate coating reduces loss of the metallic portion of the fill by diffusion or reaction and corresponding buildup of free halogen in the arc tube.
A metal halide arc discharge lamp assembly, comprising:
The process of protecting a fused silica arc tube of a metal halide arc discharge lamp, which contains a fill including sodium halide, at least scandium iodide, and an inert starting gas disposed within the arc tube, from loss of the metallic portion of the fill by diffusion or reaction and corresponding buildup of free halogen in the arc tube, the process comprising:
An arc tube of fused silica for a metal halide arc discharge lamp including a fill for the arc tube comprised of a sodium halide, at least one additional metal halide, and an inert starting gas, the arc tube comprising a tube of fused silica having an inner wall defining an arc chamber and a scandium silicate fused to the inner wall of the tube.
Dependencies are inferred from the claim text.