Patent ID: 7746000

Claim:
A discharge bulb for a vehicle, comprising: an arc tube; a glass shroud cylindrically surrounding the arc tube; and an insulated plug fixedly supporting an end portion of the glass shroud, wherein the arc tube including: a light generating portion having a discharge space therein; a first pinch seal portion and a second pinch seal portion, disposed on respective sides of the light generating portion; a first electrode rod protruding into the discharge space from the first pinch seal portion; and a second electrode rod protruding into the discharge space from the second pinch seal portion so as to be opposed to the first electrode rod, wherein a discharge light-emitting portion is formed directly from the first electrode to the second electrode, wherein the discharge space contains a rare gas and a metal halide, but does not contain mercury, the first electrode is made of thoriated tungsten, and the second electrode rod is made of pure tungsten.