Mathematical model to describe vidicon operation

A theoretical development is presented that describes the operation of a vidicon. Output current is determined for an arbitrary distribution of intensity and wavelength of illumination falling on the face of the vidicon. The nonlinear behavior of the photoconductor is taken into account. The effect of progressive erasure of the stored charge on the rear of the photoconductor with the motion of the electron beam is included. The readout beam is assumed to be Gaussian with either a circular or elliptical cross section. The effect of the electron beam on lines other than that being scanned is included. Variation in electron beam spot size across the face of the vidicon is also considered. Correlation with published output data is presented. The apparent phase shift of objects, especially at high beam currents, can be significant. Numerical results for the cases of line and sinusoidal targets are discussed in detail.