High-pressure discharge lamp

Abstract

A high-pressure discharge lamp of the invention includes a ceramic discharge vessel (10) in which a first and a second electrode (40a, 40b) are arranged and which encloses a discharge space (11 ) which is provided with a filling containing a metal halide. The discharge vessel (10) has a central zone (20) between the electrodes (40a, 40b) and a first and a second cylindrical end zone (30a, 30b) which each surround a current supply conductor (50a, 50b) connected to a respective electrode (40a, 40b). At least the first end zone (30a) has a diameter smaller than the smallest diameter of the central zone (20). The current supply conductor (50a) through the first end zone (30a) has a halide resistant portion (51a) which faces the discharge space (11) and a portion (52a) permeable to hydrogen and oxygen and facing away from the discharge space (11). The halide resistant portion (51a) extends through the first end zone (30a) over a distance that is at least the inner diameter D of the first end zone (30a) augmented by 2 mm. Furthermore, the current supply conductor (50b) through the second end zone (30b) has a halide resistant portion (51b) which faces the discharge space (11). The construction allows for a sufficient reduction of the amount of hydrogen and oxygen in the discharge vessel (10), while corrosive attack of the current supply conductors (50a, 50b) by halides is prevented.

Dependencies are inferred from the claim text.