| 摘要 |
<p>A high-pressure electrical discharge lamp has a transparent airtight electrical discharge container, an electrode composed chiefly of tungsten and placed in the electrical discharge container, and an electrical discharge medium containing a halide of a luminous metal and enclosed in the electrical discharge container. The surface of the electrode is specified as follows. The average surface roughness (Ra) along the center line on the surface of the electrode is equal to or less than 0.3 micron, or the ten-point average surface roughness (Rz) on the surface of the electrode is equal to or less than 1 micron, or the average rate of increase in the surface area of the electrode is equal to or less than 1 %.</p> |
