Method and apparatus for assembling electron gun

Abstract

Disclosed is an electron gun assembling method used for assembling a first electrode having a plurality of beam apertures as opposed to one cathode used as an electron beam emitting source with a cathode structure having the cathode. The method includes: a first step of rotating the cathode structure on its axis in a state in which the cathode structure is opposed to the first electrode, and measuring, during rotation of the cathode structure, a distance between each of the beam apertures of the first electrode and a beam emission plane of the cathode; and a second step of setting a rotational position of the cathode structure on the basis of the result measured in the first step. In the second step, particularly, the rotational position of the cathode structure may be set under a condition that the maximum one of the differences between the distances from the beam apertures of the first electrode to the beam emission plane of the cathode is minimized. With this assembling method, it is possible to reduce a variation in operational characteristics of the electron gun, such as a cutoff characteristic.

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