Abstract: An in-line electron gun includes main lens electrodes, a common aperture and, at a distance from the common aperture, three in-line apertures in a plate-shaped part. The outer apertures extend, viewed in a direction transverse to the plate-shaped part, beyond the common aperture.

Abstract: A color cathode ray tube includes an in-line electron gun having a main lens with recessed apertures. The main lens is formed by two electrodes. These electrodes have outer edges and recessed apertures which allow passage of three in-line electron beams and which are arranged at a distance d1 and d2, respectively, from the outer edges. The outermost apertures are asymmetric. The difference d1-d2 and the asymmetry of the outermost apertures is such that both the beam displacement and the core haze asymmetry are minimal.

Abstract: A color display tube system having an electron gun producing three co-planar electron beams which are non-convergent, i.e. parallel or divergent. A convergence element located at a distance from the electron gun and coaxial with the tube axis then produces convergence of the electron beams at the display screen by generating a static 45.degree. 4-pole field. This combination reduces growth of the scanning beam spot in the horizontal direction at the ends of the horizontal axis, which is a problem encountered with electron guns which are convergent.

Abstract: A display device comprising a deflection unit and a cathode ray tube having an in-line electron gun. The electron gun comprises a main lens portion having means to generate a main lens field and a quadrupole field. During operation, the intensity of the fields is dynamically varied. The electron gun comprises a prefocusing lens portion having means of generating a prefocusing lens field and a further quadrupole field. During operation, the intensity of said fields is controlled so that a dynamic cylindrical lens is formed in the prefocusing lens portion. By virtue thereof, an improved picture reproduction can be obtained.

Abstract: A color display tube system comprising an electron gun for producing three co-planar electron beams, and including a main deflection system which in operation generates deflection fields of the self-convergent type, and an auxiliary deflection system which in operation generates a 45.degree. magnetic 4-pole field facing the electron gun and moving the outer electron beams away from each other, and a 45.degree. magnetic 4-pole field facing the display screen and moving the outer beams towards each other.

Abstract: A color cathode ray tube having an integrated electron gun structure including mirrored main focusing and accelerating electrodes (46B, 52). The electron gun comprises a triode section formed by three in-line arranged cathodes (27, 28, 29) and first and second grid electrodes (30, 36) whose apertures are symmetrically disposed about respective central (21) and outer (32, 34) axes which pass through their respective cathodes. A prefocusing electrode (38) having eccentric outer apertures is positioned next to the second electrode (36). The field produced by the prefocusing electrode (38) serves to converge the electron beams produced in the triode section. At least one, but more conveniently two, further electrode(s) (40, 46A) are provided between the prefocusing electrode (38) and the main focusing lens electrode (46B).

Abstract: A color display tube system comprising an electron gun for producing three co-planar electron beams, and including a main deflection system which in operation generates deflection fields of the self-convergent type, and an auxiliary deflection system which in operation generates a 45.degree. magnetic 4-pole field facing the electron gun and moving the outer electron beams away from each other, and a 45.degree. magnetic 4-pole field facing the display screen and moving the outer beams towards each other.