Color cathode ray tube system with reduced spot growth

A color cathode ray tube system comprising

• (a) an evacuated envelope having a neck, a cone and a display window,
• (b) an electron gun in the neck, which gun has a beam-forming part for generating a central electron beam and two outer electron beams whose axes are co-planar, and a first and a second electrode system which in operation jointly constitute a main lens and are connectable to means for supplying an energizing voltage,
• (c) an astigmatic element in the electron gun for astigmatically influencing the electron beams, and
• (d) a deflection unit for generating line and field deflection fields for deflecting the electron beams, characterized in that an element causing underconvergence is arranged between the beam-forming part of the electron gun and the deflection unit, which element exerts a force on each outer electron beam having a component in the plane of the electron beams transversely to the axis of the relevant outer electron beam and remote from the central electron beam, said force deflecting the outer electron beams away from the central electron beam to cause said underconvergence, and in that the deflection unit is constructed in such a way that it generates deflection fields causing an overconvergence which compensates said underconvergence.