A cathode ray tube for displaying coloured pictures of the postfocusing type. In each aperture of the colour selection means an electrostatic postfocusing lens is formed. The electrodes of the colour selection means which have the highest potential are connected to the high voltage connection. The electrodes of the colour selection means which have the lowest potential are charged by the electron beams, their voltage being stabilized by a series arrangement of zener diodes, the cathode of which is connected to the high voltage connection.
POST-DEFLECTION-FOCUS ASSEMBLY FOR COLOUR CATHODE RAY TUBE