ARC TUBE FOR METAL VAPOR DISCHARGE LAMP AND ITS ELECTRODE SYSTEM

摘要

PROBLEM TO BE SOLVED: To prevent the generation of bubbles of CO or CO2 which might cause a leakage path in a glass frit for sealing a gap produced between the inner surfaces of slender tubes installed on both sides of a fluorescent tube body and the outer surfaces of conductive cermet rods inserted into the slender tubes. SOLUTION: Stoppers 5 for the conductive cermet rods 4 coming in contact with the glass frit are arranged on the tube end sides of the slender tubes 2a, 2b into which molten glass frit is poured, and the stoppers 5 are made of niobium or tantalum.