Abstract: A deflection unit (4) includes a saddle-shaped deflection coil (30). The deflection coil includes at either the front or rear end a concave part having a left and right corner (41, 42) which define a line (43). The concave part is flanked at either side by adjacent portions (38, 39). It holds that: &agr;>&bgr; where &agr; angle between a line (43) through the two corners (40, 41) of the concave part (40) and inner windings of the concave part (40), and &bgr; is an angle between said line (43) and the inner windings at the outer side of a corner (41,42).

Abstract: A color display device comprising a cathode ray tube and a deflection unit also includes a compensation coil or a compensation-coil system, for example, on the outside of the yoke of the deflection unit, so as to compensate for frame errors and convergence errors caused by the earth's magnetic field.

Abstract: Display tube comprising an electromagnetic deflection unit with field deflection coils of the saddle type having a lying gun-sided lobe which is provided with a plurality of sub-assemblies each comprising two longitudinal conductor groups which are connected at their gun side by means of a connection group of conductors lying flush with the longitudinal conductor groups, the first sub-assembly being arranged within the second, the second within the third, and so forth. Field coma errors, field astigmatism (isotropic and anisotropic) and north-south raster errors can be simultaneously minimized by means of such field deflection coils.

Abstract: A display tube has an electromagnetic deflection unit with line deflection coils of the semi-saddle type which are provided at their gun-sided ends with an extension having one single, wedge-shaped window directed towards the gun. Particularly line coma errors and raster errors, which occur in display tubes having display screens of small curvature and/or in the case of extreme long axis: short axis ratios, can be minimized with such line deflection coils.

Abstract: A color cathode ray tube of the type having a color selection electrode arranged in front of the display screen, is characterized in that the inner surface of the screen exhibits a deviation from an arc shape along the long X axis such that, in operation, the effect of doming is reduced. Preferably, the deviation decreases as the distance to the long axis increases. In an embodiment, the inner surface also exhibits a deviation from an arc shape along the short y-axis.

Abstract: A cathode ray tube comprising a rectangular display window whose thickness increases from the center of the display window along the long and the short axes. The thickness D (x) of the display window along the long axis (x) is defined by:D(x)=D.sub.O +.DELTA.(x);the thickness D(y) of the display window along the short axis (y) is defined by:D(y)=D.sub.O +.DELTA.(y);where D.sub.O is the thickness at the center of the window, and .DELTA.(y) is larger than 1.5.DELTA.(x). The display window thus formed combines a large strength with a relatively low weight. The invention is of particular importance in cathode ray tubes having a length: width ratio which is larger than 4:3, for example 16:9, and in large (.gtoreq.28 inch) tubes.

Abstract: Deflection unit mounted around a display tube for deflecting electron beams across the display screen includes a line deflection coil and a field deflection coil. A compensation coil system for generating a magnetic compensation field oppositely directed to the line frequency radiation field in a space in front of the display screen includes core means of a magnetizable material positioned between the display screen and the deflection unit in a plane parallel to the display screen and two diametrically arranged coils each having at least one turn.