Kinescope Spot Size as it Relates to Picture Quality

The degradation of kinescope spot size (spot blooming) with increasing beam current is a well known phenomenon that has significant bearing on kinescope resolution. For purposes of improving kinescope design evaluation and production lot monitoring, it is desirable to quantify the effects of beam current on picture quality. The basis for this paper is the assumption that kinescope performance can be defined in terms of its spatial frequency response. Computer oriented techniques which are employed to analyze a light output profile of the spot and calculate the associated spatial frequency response of the kinescope are discussed. In addition, the non-linear effects of the human eye are considered. Advantages and disadvantages of both techniques are examined and some typical measurements are shown.