An analysis of focusing and deflection in the post–deflection–focus color kinescope

In the Post-Deflection-Focus Color Kinescope, there is an array of parallel wires next to the phosphor screen for the purpose of focusing the electron beam and for deflecting it up and down in order to change colors. Expressions are derived for the deflection sensitivity and focusing properties of such a system which are applicable for all points within the picture area. The theoretical results are compared with experimental measurements; good agreement is obtained. Contour maps showing the variation over the grid plane of deflection sensitivity and the voltage ratio for optimum focus are included.