| 摘要 |
PURPOSE:To arrange electrode supports at a wider space and improve the characteristic of dielectric strength mutually between a focusing electrode and anode, in which a high potential difference is generated, by unequally dividing lengths in the axial direction of each set of the electrodes piled on one another. CONSTITUTION:An electrode structural body 2 for an electron gun is held and fixed by arranging a cathode structural body 10, consisting of three cathodes insulated from one another arranged in a row at an equal distance apart in the same plane, G1 electrode 11 as a control electrode, G2 electrode 12 as an accelerating electrode, G3 electrode 23 as a focusing electrode and G4 electrode 14 as an anode on the same axis, embedding and welding supports 15 to a support lever 16. While a mutual space between the face-to-face positioned electrode supports for the G3 electrode 23 and G4 electrode 14, in which a high potential difference is caused, is arranged in a dimension as large as possible. In this way, the distance mutually between the face- to-face positioned electrode supports 15 for the G3 electrode 23 and G4 electrode 14 is set at a valve larger than that between the supports when the G3 electrode 23 is equally divided. |
