Patent-treuhand-gesellschaft F. Elektrische Gluehlampen Mbh

Ngk Insulators, Inc.

Rita Tiedt

Dieter Lang

Roland Huettinger

Koichiro Maekawa

Helmut Weske

Junichi Doi

At least at one end of a discharge lamp, for example a metal-halide discharge lamp or a sodium high-pressure discharge lamp, which has a ceramic discharge vessel (,), a feed-through (,) is provided which includes a cermet. The cermet may be in pin or capillary tube form, and has a metal content which is so high that it can be welded like a metal. The cermet can be directly sintered into an end plug (,) or into an end portion (,) of the vessel itself. The seal thus is effected by a sealing arrangement (,) devoid of glass melt, which would be degraded by attack of corrosive fills within the lamp, while additionally having the capability of withstanding higher operating temperatures.

Metal halide or sodium high pressure lamp with cermet of alumina, molybdenum and tungsten

A ceramic discharge vessel (6) for a high-pressure discharge lamp (1) made from a sintered body of optically translucent polycrystalline alumina ceramic which is doped with only 100-800 ppm MgO, only 200-1200 ppm ZrO.sub.2 and only 10-300 ppm Y.sub.2 O.sub.3 (by weight). This improves the loading capacity and operating characteristics of the vessel and of the lamp.

High-pressure discharge lamp having a ceramic discharge vessel, sintered

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Berlin, Germany

Rita Tiedt