| 摘要 |
PURPOSE:To facilitate manufacture and reduce is cost by forming a grid electrode with an expanded metal. CONSTITUTION:A discharge electrode 2 and an expanded metal grid electrode 8 are installed in a gutter-shaped shield 1. This grid 8 is prepared by forming plural rows 10 of chain-like slits almost parallel to a metallic plate 9, and stretching the plate 9 in the direction almost perpendicular to the slit rows 10 to expand each slit and form it into a net-shape. Since the grid electrode is thus formed, its manufacture is made easy and inexpensive. |
