摘要:
The present invention relates to a metal halide lamp substantially containing no mercury, a metal halide lamp lighting device using the same and an automotive headlamp apparatus using the same. And object of the invention is to provide such products in which a rapid rising of luminous flux is achieved. A metal halide lamp (MHL) according to the present invention has: a discharge vessel having an inner volume of C (cc) and having a pair of electrodes (2), (2) sealed in a hermetic vessel (1a) at opposite ends of a discharge space (1a) in the hermetic vessel (1a) at a distance of 5 mm or less; and a discharge medium containing xenon gas at 3 atmospheres or higher, a halide of sodium Na, and at least one of halides of scandium Sc and rare earth metals, the melting point of the halides being T (K), in which a lamp power in a stable state is 50 W or lower, and the formula (1) is satisfied: (H/C)×[R/(T/500)6]