Sensitivity Analyses for Construction of Monochrome Electron Guns

摘要

Manufacturing irregularities and misalignments in electron guns for CRTs degrade the resolution, especially at high brightness. Using simulations of an electron gun that are 3D and include space charge, the spot size, which directly determines resolution, is calculated. These simulations are then used to calculate the sensitivities of spot size to misalignments part-size tolerances, and lens out-of-roundness. Sensitivities for the manufacture of electron guns are defined and calculated. These sensitivities connect misalignments, part-size tolerances, and lens out-of-roundness to beam displacement in the lens to beam size in the lens, and to focus astigmatism, respectively. With specifications for tolerances and misalignments, the distribution of spot sizes expected in manufacturing CRTs can be calculated. The importances of the specifications are prioritized in Pareto charts. Logistics show which construction irregularity groups are benign and which ones threaten production crises. While monochrome electron guns are used to illustrate these concepts, they have been used for color electron guns and nanolithography, and they are applicable to many electron-optical systems.