| 摘要 |
PURPOSE:To reduce the variation of the potential on the inner wall of a neck portion near electrodes constituting a main electron lens and on a bead glass surface and stabilize the potential at an early time by providing a screening body blocking unnecessary electrons passing through a gap between a convergence electrode and the inner wall of the neck portion on an electron gun body structure. CONSTITUTION:An electron gun body structure 34 is constituted with a cathode 21, the first electrode 22, the second electrode 23, the third electrode 24, the fourth electrode 25, and a convergence electrode 26. These electrodes are melted and fixed with a bead glass 30 and stored in a neck portion 11. A bulb space is fixed to the convergence electrode 26, and its tip is connected to an inner conductive film 20 on the inner wall of the funnel portion 12. A screening ring 40 formed of a stainless material having a diameter of about 1.0mm. in an annular shape having a maximum diameter of about 17.0mm. is fitted between the panel portion side of the convergence electrode 26, i.e., the vicinity of the upper end portion of the convergence electrode and the inner wall of the neck portion 11, and it is supported by the bulb spacer 37. A gap between the inner wall of the neck portion 11 and the convergence electrode 26 is practically blocked by the screening ring 40. |
