Patent ID: 8193711

Claim:
A metal halide lamp, comprising: an airtight tube having a discharge section with a discharge space formed therein; a discharge medium enclosed in the discharge space, the discharge medium containing metal halide exhibiting a molar ratio of sodium halide to scandium halide of 1.5 or below, the metal halide having halogen atoms bonded to metal therein mostly consisting of iodine and bromine atoms, the metal halide having a bromine at a rate of 10% to 50% by a ratio of the bromine atoms to the total halogen atoms, the metal halide being enclosed with a total enclosed amount per unit volume of the metal halide being 0.02 mg/μl or below in the discharge space, and 8 atm or higher of xenon, wherein the discharge medium does not substantially contain mercury; and a pair of electrodes with their tip ends arranged to oppose to each other in the discharge space, and wherein the metal halide further contains 1.0 wt % to 5.0 wt % zinc halide.