| 摘要 |
PURPOSE:To accurately set the gap between the first grid and the electron emission surface of a cathode even when the diameter of the electron beam permeation hole of the first grid is small by using a dummy air micro nozzle with a level surface. CONSTITUTION:A dummy air micro nozzle 14 provided with a flange 16 having a level surface 21 is arranged in front of the electron emission surface 6 of a cathode 1 and is adjusted to a gap 7 to be set and then the amount of air jetting 22 is obtained. In addition, the position of an air micro nozzle 20 is adjusted and held at the side of the cathode 1 and the amount of air jetting 26 is obtained. Then a nozzle 14 is removed and is opposed to the first grid 2 incorporated in an electron gun 24 and then the amount of air jetting of the nozzle 20 is adjusted by moving the grid 2 so as to be the same as the amount 26 obtained before. As a result, even when the diameter of the electron beam permeation hole 5 of the first grid 2 is small the cathode 1 can accurately be fixed and high resolution can be obtained. |
