Patent ID: 7279839
Filing Date: 2007-10-09
Classification: H01J

Abstract:
1. A short arc high-pressure discharge lamp ( 1 , 28 ) for direct current operation, having a discharge vessel ( 2 , 29 ) which includes two diametrically opposite necks ( 4 ; 30 , 31 ), into which an anode ( 26 , 36 ) and a cathode ( 7 , 33 ), in each case made from tungsten, are fused in a gastight manner and which contains a fill comprising at least one noble gas and optionally mercury, characterized in that at least the material of the cathode tip ( 11 , 34 a ), consists of tungsten, lanthanum oxide La 2 O 3 and at least one further oxide selected from the group consisting of hafnium oxide HfO 2 and zirconium oxide ZrO 2 .