| 摘要 |
<p>PURPOSE:To produce high quality images with minimal density nonuniformity by installing surface-like cathodes which radiate thermions from their surface toward an anode. CONSTITUTION:In a vacuum space located over a grid 5, surface-like filament cathodes 6 are installed which radiate thermionic rays from their surface. Each filament cathode 6 is formed by densely arranging several filaments prepared by applying an oxide to fine tungsten wires in a direction vertical to a base plate 1. And, a pair of the filament cathodes 6 are installed symmetrical about the central surface where a phosphor array 3 is located. Because of the above structure, thermionic rays are radiated from the entire surfaces of the cathodes 6. Consequently, it is possible to form high quality images with minimal density nonuniformity.</p> |
