Abstract: A single gun color cathode ray tube (CRT) having a screen consisting of alternating red, blue and green vertical phosphor strips in groups of three, with strips of conductive or photovoltaic material overlaying each phosphor strip, or placed between adjacent strips. The same color conductive strips are connected in parallel in three arrays, and connected to three individual trigger buses. The conductive lines are connected to a positive bias voltage such that when the electron beam within the CRT strikes a conductive strip, a pulse is generated and fed to the corresponding trigger bus. As the single electron beam scans the screen, trigger pulses are generated in the conductive strips and are fed to a trigger pulse amplifier and then to a multiplexer and used as control signals.