Metal halide lamp

摘要

In a metal halide lamp in which Hg, a rare gas and InI and HoI3 are filled, filler amount of InI is in a range of 0.1 mg/cc to 1.5 mg/cc, and filler amount of HoI3 is in such range that an evaporable amount of said halide depending on the temperature of said halide is the minimum filler amount and 3.0 mg/cc of said halide is the maximum thereof, and thereby a lamp having a high efficacy in which an emission spectrum is well distributed over a visible range can be obtained, having also a long lifetime because devitrification of an arc tube is restricted. <IMAGE>