| 摘要 |
PURPOSE:To improve the withstand voltage characteristics of a cathode by surrounding with a metallic member covering the neck-facing surface of a bead glass from an electrode, the electrode is not the electrode nearest to the cathode and fluorescent screen, and forming a sputtered film on the inside wall of the neck. CONSTITUTION:The inside wall of the neck 37-facing surface of a bead-glass 36 of an in-line type bipotential electron gun is surrounded with a metallic member 38, and the both ends of it is fixed to the third grid electrode 33. The electrode to which the metallic member 38 is fixed is not confined to the third grid electrode, and an electrode which is not nearest to the cathode and fluorescent screen may be selected. Then, a part of the metallic member 38 is evaporated by high frequency heating during exhausion process to form a sputtered film 39 on the inside wall of the neck. Thus, the sputtered film prevents the emission of secondary electrons, and stabilizes the neck-inside-wall voltage to reduce the discharge. |
