Recent developments in beam-index color-display systems

In the beam-index color-television tube, a single electron beam is scanned horizontally across a structure of vertical red, green, and blue phosphor lines in a conventional raster. Color reproduction is obtained by sequential application of the red, green, and blue color signals to the beam, taking care that the instantaneous color signal corresponds to the color of the phosphor strip being hit by the electron beam. The correct time sequence of this process is controlled by a signal, generated by the index tube, indicating the instantaneous position of the electron beam.