Low-pressure mercury-vapor discharge lamp having electrode shield carrying direct electric current

Abstract

A low-pressure mercury-vapor discharge lamp is provided with a discharge vessel and a first and a second end portion ( ). The discharge vessel encloses a discharge space provided with a filling of mercury and an inert gas in a gastight manner. Each end portion ( ) supports an electrode ( ) arranged in the discharge space. An electrode shield ( ) encompasses the electrodes ( ) and, according to the invention, carries an electric current during operation, and is at a temperature ≧250° C., preferably ≧450° C., during nominal operation of the discharge lamp. Preferably, a first current supply conductor ( ) electrically contacts a first current divider ( ), which is electrically connected to a second current divider ( ′) via a shell-shaped body ( ). Said second current divider ( ′) electrically contacts the electrode ( ), which is connected to the second current supply conductor ( ′), the electrode shield ( ) is made from stainless steel, in particular a chromium nickel steel. Preferably, the heat dissipation of the electrode shield ( ) during nominal operation ranges between 0.1 and 10 Watts. Preferably, the electrode shield ( ) is made from a ceramic material or carbon. The discharge lamp exhibits a comparatively low mercury consumption.