Electric discharge lamp

Abstract

An electric discharge lamp comprising: a light-transmissive ceramic lamp vessel; a first and a second current conductor each supporting an electrode in the lamp vessel; an ionizable filling comprising a noble gas and metal halide in the lamp vessel; at least the first current conductor being halide-resistant characterized in that the first current conductor forms an end wall of the lamp vessel, wherein the difference between the coefficient ai of linear thermal expansion of said end wall and the coefficient a2 of linear thermal expansion of the lamp vessel is equal to or less than 2.10-6 K1; or the first current conductor is at least partially provided at its outer surface with a halide-resistant layer, wherein the difference between the coefficient a1 of linear thermal expansion of said first current conductor and the coefficient a2 of linear thermal expansion of the lamp vessel is equal to or less than 2.10-6 K−1, and wherein said first current conductor is made of a metal, particularly a metal selected from the group consisting of titanium, palladium, platinum, vanadium, lutetium and rhodium, or an alloy thereof.

Dependencies are inferred from the claim text.