In the previnus paper, the field calculatin for focus deflection system of a cam-era tube with electrostatic deflection yokes were deseribed. Now that the potential field is known we can treat the trajectories described by the electrons in this field. The electron trajectory calcula-tion in the focus-deflection system with the electrostatic deflection differs from usual trial solution determined by the discrete methods in the rotationally system field. Because poteotial fuoction of the focus-deflection field determined by the analytic method are analytic fuoctions of the variations r, θ, z, in the tracing process of the electron trajectories the potential and it's deriva-tives at an arbitrary point may be given by the aoalytic fuoctions.The purpose of the paper is to give the method of solving geoeral equation of motion for an electron in mixed field which produces a combined electromagnetic focus field and the electrostatic deflection field.

An electrostatic deflection-type camera tube has the following advantages: The small electron beam spots over the entire the scanned area provide uniform and high resolution picture, normal beam landing performance and deflection linearity are also excellent. The purpose of the paper is to .give the field calculation for focus deflection system of a camera tube with electrostatic deflection yokes.

Based on the finite difference method and the statistical theory of thermal electron emission, a set of computing and plotting programs using to computer aided design of electron beam device for electron guns and image tubes has been written in FARTRAN77 running on MV/8000 digital computer, and a good agreement between calculated result and that measured or given in ref has been obtained, This paper presents some numerical methods, such as optimization of Lagrange's interpolation function, determination of the optimum image plane using the statistical radius of the Airy disk, the tracing methods of equipotential lines and ion trajectories and so on. and some examples of the practical application, such as calculation and design for guns and image tubes, and analysis of the ion feedback in image tubes has been given.