Patent ID: 7635950
Filing Date: 2009-12-22
Classification: H01J

Abstract:
1. A short-arc type high pressure discharge lamp having gaps formed among electrode axes, metal foils and a glass material surface, comprising: a discharge container made of glass material, having two axis portions and a swelled portion between the two axis portions; two electrodes, each having an electrode axis and an electrode body at the end of the electrode axis; and two metal foils, each being strip-shaped and having a connection portion at one end, wherein the connection portion of each metal foil is partitioned widthwise into a widthwise middle portion and two widthwise side portions, and the widthwise middle portion is curved to form a groove extending in the longitudinal direction of the metal foil, the groove including: and wherein the electrode axes of the two electrodes are welded to the bottoms of the grooves of the respective metal foils, the bottoms partially wrapping the respective electrode axes, and wherein the bodies of the two electrodes are housed in the swelled portion of the discharger container, with the electrode axes and the welded metal foils extending to the respective axis portions of the discharger container, and wherein the axis portions of the discharger container are fused to hermetically seal the electrode bodies of the two electrodes in a discharge space located in the swollen portion of the discharger container, and wherein within each of the fused axis portions, two gaps are formed among the glass material, the circumferential surface of the electrode axis, and the longitudinal convex surfaces of the groove of the metal foil, and the gaps are connected to the discharge space in the swollen portion of the discharger container, and wherein within each gap, an obtuse angle is formed between the glass material and the longitudinal convex surface for preventing formation and growth of cracks in the interface of the glass material and the metal foil.