| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ultra-high pressure mercury lamp in which the tip position of the electrode is suppressed from retreating and a high illuminance maintenance factor can be obtained even when lighted for a long time. <P>SOLUTION: The ultra-high pressure mercury lamp has a pair of electrodes, which have a bar-shape shaft part of which the base end portion is embedded and supported in the sealing part in an arc tube having a light-emitting part and a sealing part connected to both ends of the light-emitting part, arranged so as to be mutually opposed. At least one of electrodes has a head portion having a larger diameter than the shaft portion, and an electrode material replenishing portion which extends by projecting integrally continued from the rear end face of the head portion and is provided separated from the shaft portion. <P>COPYRIGHT: (C)2011,JPO&INPIT |
