Abstract: A color cathode ray tube having an in-line electron gun in which convergence drift is reduced significantly by providing conductive islands (32,34) in the form of metal mirrors on the internal wall of the neck. The islands (32,34) are located on and about the plane of the electron beams and face only the higher voltage one of the main focusing electrodes (g3,g4). The islands (32,34) float electrically. Additionally convergence stability can be improved by providing a ring or strip (36) about the external surface of the neck in the vicinity of the gap between the focusing electrodes (93,94), which ring or strip (36) is connected to a point of fixed potential such as ground.

Abstract: In a color television display tube the electron gun system constructed from three electron guns comprises a first group of corresponding electrodes and a second group of corresponding electrodes to be operated at a higher electrical potential than the first group. The electrodes in each group are positioned relative to each other by means of metal braces connected thereto. The ends of the braces are secured to insulating support rods. At least one group of corresponding electrodes is interconnected by means of one or more conductive contact springs surrounding the support rods and touching the surface of each electrode or of the brace connected thereto.

Abstract: A picture display tube comprising an internal resistive layer to restrict the peak current which at the operating potential of the tube is associated with an electrical flash-over possibly occurring therein. The effective part of the resistive layer extends in the neck and over the transition from neck to cone of the envelope of the tube. The resistive layer represents a static resistance value of at most 10.sup.4 Ohm and a dynamic resistance value of at least 300 Ohm.