| 摘要 |
<p>An electrode end is accurately positioned so that the arc length is constant, and when electrode mounts are sealed by heating a sealing part, a leakage caused by bending and twisting of a molybdenum foil is prevented from occurring at the sealed part. A quartz bulb (10) has openings at opposite ends of a body pipe (11) where a light emission part and sealing parts are formed, and the quartz bulb (10) also has a positioning step (15) formed by fusion bonding extension pipes (14A, 14B) to the openings. The extension pipes (14A, 14B) have an internal diameter greater than the internal diameter of the openings. The electrode mounts (20A, 20B) having a positioning engagement part (24) located at a position a predetermined distance away from the electrode end is inserted into the quartz bulb, and sealing parts (13A, 13B) are sealed with the positioning engagement part (24) of the electrode mounts (20A, 20B) engaged with the positioning step (15).</p> |
