Patent ID: 7211956
Filing Date: 2007-05-01
Classification: H01J

Abstract:
1. Short arc ultra-high pressure mercury lamp, comprising: a silica glass arc tube, a pair of opposed electrodes disposed in the arc tube with a distance of at most to 2 mm between them, and the arc tube being filled with at least 0.15 mg/mm wherein at least one of the electrodes includes a rod having a tip with an area toward the tip of the rod wound with a coil, wherein a front part of the coil oriented towards the tip of the rod is melted and a back end of the coil extending from the front melted part in a direction away from the electrode tip is unmelted and has a base point that is rounded and is free of sharp edges, wherein the shortest distance between the coil and an inside surface of the arc tube is at most 2.0 mm.