Patent ID: 7705540

Claim:
A high pressure discharge lamp comprising a transparent discharge vessel, an ionizable filling and electrodes, the ionizable filling arranged in the discharge space of the discharge vessel, and the electrodes arranged to extend into the discharge space of the discharge vessel, for the purpose of producing a gas discharge, the lamp further comprising a base arranged at an end of the high pressure discharge lamp, wherein said discharge vessel comprises a proximate sealed end which is arranged near to the base and a distal sealed end which is arranged remotely from the base, wherein a power supply line is passed out of each of the afore-said sealed ends of the discharge vessel, for the purpose of supplying energy to the electrodes, and the power supply line which is passed out of said distal sealed end is connected to a power return line which is passed back to said base, and the lamp further comprising an electrically conductive transparent layer which is in the form of a partial coating on the outer surface of the discharge vessel, with the result that a capacitive coupling is produced between the said partial coating and at least one of the electrodes and at least one of the power supply lines, said partial coating being arranged on a region of the outer surface of the discharge vessel which faces said power return line and extending over part of the circumference of the discharge space, and wherein said at least one power supply line comprises at least one molybdenum foil embedded in a material of the discharge vessel, and said partial coating extends up to the at least one molybdenum foil of said at least one power supply line, wherein said at least one molybdenum foil is oriented such that one of two sides of said at least one molybdenum foil faces said partial coating.