GB1537070A - Colour television tube assemblies - Google Patents

Abstract

1537070 Colour television tubes MATSUSHITA ELECTRONICS CORP 21 Jan 1976 [24 Jan 1975 31 Jan 1975] 02247/76 Heading H1D In a self-convergence colour television tube having an assembly of three in-line guns, the convergence of which is produced, without a dynamic deflection circuit, by the use of a pincushion-shaped horizontal deflection magnetic field and a barrel-shaped vertical deflection magnetic field, the resulting distortion of the beam spot on the screen, i.e. horizontally elliptical towards all the screen boundaries (Fig. 1, not shown)-is modified to render it visually more acceptable by providing the beams with an initial vertically elliptical cross-section, by the use of vertically elliptical gun control grid apertures, and subsequent lens electrodes differently dimensioned along their horizontal and vertical axes, to provide differing horizontal and vertical convergence, thereby to provide a beam spot distortion distribution over the screen as shown in Fig. 4. In Fig. 6, the elliptically apertured control grid 1 is followed by an electrode 40 which has an apertured protruding portion 41 with smaller horizontal dimension h x than vertical dimension h y . In a further arrangement (Figs. 11 and 12, not shown) the plate 40 is apertured only opposite the aperture in the protruding portion 41. In Fig. 8, the inequality of horizontal and vertical convergence action is produced by the pair of vertically extending members 92, 93 flanking the electrode aperture. In a further arrangement (Figs. 9 and 10, not shown) two opposed electrode plates (95, 100) have oppositely disposed elliptical apertures (96, 101).