Abstract: A display device comprising a cathode ray robe having a deflection unit with elongated compensation coils for compensating the stray field of the deflection unit next to the display device. The distance between the coils is preferably at least 0.7 times the dimension of the display window in the line deflection direction, and the length/width ratio of the coils is at least 3:1.

Abstract: A color display tube is provided with a high resistance layer having a resistance between 10.sup.6 and 10.sup.10 ohms per square on the external portion of the tube envelope underneath the deflection coil system. The high resistance layer prevents arcing between the coil system and the envelope without adversely affecting the deflection field.

Abstract: A flat display tube comprising an emission system (3) for emitting a planar electron beam (20), a modulation system (22) and a deflection system (5a, 5b, 28) for deflecting the planar electron beam towards the modulation system (22), which flat display tube also comprises a selection system (23) for selecting the planar electron beam transversely to this beam. The thickness of the electron beam (20) is increased by mutual repulsion of the electrons in the planar electron beam. The selection system in the flat display tube precludes that this adversely affects the resolution of the picture on the display screen.

Abstract: A color television display tube having color selection means connected electrically by at least one metal contact spring to a resistive layer provided on the inner surface of the envelope of the tube. A low resistance contact face is applied on the resistive layer between the spring and the layer to reduce the contact resistance therebetween, thereby reducing undesirable interference radiation transmitted by the tube.