| 摘要 |
<p>RCA 71,751 An electrode of the electron gun assembly has two accurately positioned alignment apertures therein, a line connecting the centers of the alignment apertures being transverse to the central longitudinal axis of the gun assembly. The alignment method includes holding the electron gun assembly relative to the cathode-ray tube envelope and directing a collimated light beam toward the alignment apertures. Next, the position of the electron gun assembly is rotationally stepped about its central longitudinal axis while the light source is pulsed in coordination with the steps of the electron gun assembly. During the rotation, the number of light pulses passing through the alignment apertures are counted up. Thereafter, the stepping direction of the electron gun assembly is reversed and the number of light pulses passing through the alignment apertures are counted down. The reverse rotation of the electron gun assembly is stopped when the number of counted down light pulses are half of the maximum number of light pulses counted up.</p> |
