| 摘要 |
PROBLEM TO BE SOLVED: To achieve excellent thermal conductivity in a discharge lamp including an electrode formed by different members being joined by diffusion junction.SOLUTION: A short arc type discharge lamp 10 includes: a tip side member 22 made of thoriated tungsten; and a cathode 20 to which a rear end side member 24 made of tungsten is joined by solid phase bonding. A cover member 40 is installed on a taper surface of the cathode 20 so as to cover a periphery PS of a joint surface S. The cover member 40 is retained by retainers 50A, 50B.SELECTED DRAWING: Figure 3 |
