High-pressure metal vapor discharge lamp.

摘要

A high-pressure metal vapor discharge lamp comprising an outer tube (1), a light emitting tube (5) located within the outer tube (1) and made of a light-transmissive ceramics material, and a fuse (20) electrically connected in series with the light emitting tube (5), in which said fuse (20) has such a blowing characteristic as given by the following equation and at a rated output during the lighting of the lamp the density of a current through the fuse (20) is not more than 23.9 A/mm2:A = -1.02 x 10-2 (D2t) - 0.885B = 2.64 × 10-2 (D2t) + 1.01T : required blowing time (seconds) of the fuse (20)I : blowing current (A) of the fuseD : inner diameter (mm) of the light emitting tube (5)t : wall thickness (mm) of the light emitting tube (5).