| 摘要 |
PURPOSE:To increase the roundness of plural cylindrical electrodes, which form the electron lens part of an electrostatic focusing image pickup tube, by installing the said electrodes inside a cylindrical insulating body, and inserting electrode fixing pieces into a number of holes provided in the side wall of the said cylindrical body so as to make the said electrodes to be joined and fixed together. CONSTITUTION:An electron lens part consisting of a third grid 9, a fourth grid 10, and a fifth grid 11 is installed inside a cylindrical body 16, which has electric insulating property and is made of a material such as glass, ceramics, alumina or steatite. A number of holes 16a are provided in the side wall of the body 16 so that they correspond to the grids 9, 10 and 11. In addition, electrode fixing pieces 17 are inserted into the holes 16a, and are fixed to the grids 9, 10 and 11 by welding. As a result, the roundnesses of the grids 9, 10 and 11 are increased by facilitating the assembly of the image pickup tube by enabling metal cores to be inserted into the grids 9, 10 and 11 during the assembly. |
