| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a short arc high pressure discharge lamp, designed for DC operation with nominal power of 1 kW or greater, which improves anode shape stability and evaporation resistance, and also excels in anode processability even after the anode material is subjected to high temperature processing. <P>SOLUTION: The number of crystal grains which a tungsten based material has in a bulk region 4b is more than 100 grains per 1 mm<SP POS="POST">2</SP>, in which case the number of crystal grains is measured in a second plane perpendicular to a vertical axis Z of an anode 4, and, furthermore, the second plane has a distance s in the axial direction to the surface of a functional surface region 4a (where s is larger than d). There exists a rapid change in the crystal grain size of the tungsten based material of the anode 4 between the functional surface region 4a in a direction parallel to the vertical axis Z and the bulk region 4b. As for others, charging pressure, the amount of charged mercury, electron radiation material, electrode shape and electric power are regulated. <P>COPYRIGHT: (C)2013,JPO&INPIT |
