Patent ID: 6049169
Filing Date: 2000-04-11
Classification: G02B,H01J

Abstract:
An electric lamp assembly comprisinga lamp vessel sealed in a vacuum tight manner,an electric element arranged in the lamp vessel and connected to current supply conductors extending through the lamp vessel,a hermetically sealed outer envelope in which said lamp vessel is located, said outer envelope having a filling consisting essentially of inert gas surrounding said lamp vessel, andan interference filter on the lamp vessel, said interference filter comprising alternating first and second layers, said first layers consisting essentially of SiO.sub.2, and second layers consisting essentially of a mixture of Nb.sub.2 O.sub.5 and Ta.sub.2 O.sub.5, said mixture having a least 20% Nb.sub.2 O.sub.5 by weight and at most 40% Nb.sub.2 O.sub.5 by weight.