An examination of cathode-ray-tube screen characteristics

The development of cathode-ray tubes for radar has demanded improved screen performance. A wider range of screen types was found to be necessary, and many of these types were of a complex character. This paper deals with the general problems of screen design, with the exception of problems of afterglow, which are treated elsewhere. The approach to the problem has been photometric, and less emphasis is placed upon the electrical characteristics of screens than upon their optical properties. A range of luminescent materials was examined, and their luminous efficiency measured under the conditions of screen voltage and beam-current density normally met with in practice. The effect of various common methods of screen preparation upon colour and efficiency was studied, and also the various causes of loss of luminous output. A study of the optical properties of screens was undertaken with reference to methods of measuring and specifying screen thickness, and to the effect of the texture of the screen upon its value as a radar indicator.