| 摘要 |
PURPOSE:To prevent any electric short-circuits from developing between signal electrodes by preventing any adhesion of an evaporated substance by providing openings located between modulation electrode pieces in at least areas of an insulating base plate which face a linear hot cathode. CONSTITUTION:An insulating base plate 4 has openings 7. Sections of the base plate 4 on which modulation electrodes 5 consisting of conductors facing a linear hot cathode 3, have a shape gradually becoming wider toward the linear hot cathode 3 such as a reverse triangle or a trapezoid. Such a shape can be easily obtained by performing photoetching on a photosensitive glass. Owing to this shape, a conductive substance evaporated by heating the linear hot cathode 3 is masked by the modulation electrodes 5 and does not adhere to the sections of the insulating base plate 4 located under the electrodes 5, thereby preventing any electric short-circuits from developing between the electrodes 5. |
