摘要 |
A metal vapor discharge lamp comprises a discharge tube having a ceramic container into which a pair of electrodes and a discharge metal compound are sealed. The container comprises a first cylindrical portion, tapered portions, second cylindrical portions and third cylindrical portions. The third cylindrical portions are shrinkage-fitted to the second cylindrical portions. The electrodes are attached to the third cylindrical portion with a sealing member. An inner wall of the third cylindrical portions and the electrodes define a gap. The inner surface of the tapered portions and a central axis of the electrodes define an angle of 40°-80°. Thus, a metal vapor discharge lamp is provided whose discharge tube does not include disks among its parts, and which can maintain, over a long period of operation, good operating characteristics that depend only little on the lamp orientation.
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