Patent ID: 6879101

Claim:
A metal halide lamp, comprising: a hermetic vessel which is fire resistant and translucent; a pair of electrodes sealed in the hermetic vessel facing each other at a distance of 5 mm or less, the electrodes each having a shaft part having a diameter of 0.25 mm or more and a tip part having a diameter of the same or less than the diameter of the shaft part, and a place for an arc to originate at the tip part has a curved surface with a radius of one-half or less of the diameter of the shaft part; and a discharge medium substantially containing no mercury, sealed in the hermetic vessel, and containing halides of metals including a light-emitting metal in an amount o 0.005 mg/mm 3 of an inner volume of the hermetic vessel or more and a xenon gas at 5 atmospheres or higher at a temperature of 25° C., wherein, in a stable state, the metal halide lamp is turned on with a lamp power of 60 W or lower.