Discharge lamp

摘要

An arc tube 6 of discharge lamp comprises a main tube body 11 of translucent ceramic sealed with a terminal plate 13 at both ends thereof. The main tube body 11 comprises integrally a large diameter portion 11A, a tapered portion 11B which is disposed at both sides of the large diameter portion 11A and has a smaller diameter toward the forward end thereof, and a small diameter portion 11C connected to the forward end of the tapered portion 11B. The curvature radius R of the border of the tapered portion 11B with the small diameter portion 11C is not smaller than 2 mm.