Abstract: The invention relates to a color display device comprising an in-line electron gun (5) for generating three electron beams (6,7,8), and a convergence unit (14′) to dynamically influence the convergence of the electron beams, preferably to decrease a distance (p) between the electron beams. The convergence unit (14′) comprises a ring-shaped element (21′) having four coils (22′). The coils (22′) comprise electrically conductive wires, which have been toroidally wound in a winding direction and according to a winding density distribution N (&phgr;) given by N (&phgr;)=N0 cos (2&phgr;). Here &phgr; is an angle enclosed by the X-direction and a line between an element of the coil and the center, which ranges between 0° and 360°, N0 is the winding density at &phgr; equal to 0°, and the sign of N &phgr; denotes the winding direction.

Abstract: The invention relates to a color display device comprising an in-line electron gun (5) for generating three electron beams (6,7,8), and a convergence unit (14) to dynamically influence the convergence of the electron beams, preferably to decrease a distance (p) between the electron beams. The convergence unit (14) comprises a ring-shaped element (21) having four coils (22) and a longitudinal axis (24). A cross-section of the ring-shaped element (21) with a plane perpendicular to the longitudinal axis (24) is a circle with the longitudinal axis as its center and the ring-shaped element (21) forming the circumference. Each coil extends over the circumference over an angle &phgr; having a value between 50° and 75°.

Abstract: The invention relates to a deflection unit (10) for cathode ray tubes in which the external magnetic stray fields are further reduced and the sensitivity of the line deflection coils (17) is increased. This is done by applying a (preferably plastic deformable) magnetic material (56) in the first void spaces (52) between the wire strands (50) of the field deflection coils (18) and/or the second void spaces (54) between the field deflection coils (18) and the yoke ring (22). The plastic deformable magnetic material (56) can be additionally used for adhering the yoke ring (22) to the field deflection coils (18).

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 method of continuously winding in a recess-shaped winding space a saddle-shaped, flared deflection coil having two arcuate connection portions at the ends and two interposed coil flanks. Since a plurality of evenly distributed projections is inserted into the winding space during winding, reset points are provided in portions where the coil flanks are wound, which reset points counteract possible wire positioning errors (so-called winding spread) giving rise to a spread of line astigmatism when the coil is combined with a display tube.

Abstract: In-line color display tube with a deflection unit, provided with a twist correction device comprising two permanent magnets which generate magnetic fields with oppositely directed magnetic field components which, at the beginning and the end of a path traversed by each side beam, are transverse to the path of the relevant side beam and are located in the plane of the beams. This provides the possibility of deflecting each side beam once up and once down for compensating twist errors.

Abstract: Method of continuously winding in a gap-shaped winding space a saddle-shaped, flared deflection coil having a flange-shaped connection portion at its widest and extending transversely to the longitudinal axis. Since at least one symmetrical pair of pins is introduced at the front end of the coil into the winding space transversely to the plane of the flange-shaped connection portion and at least one further symmetrical pair of pins is introduced at the front end of the coil into the winding space transversely to the plane of the longitudinal turns, the designer of the coil is given an extra modulation possibility which can be utilized, for example to further reduce the east-west raster distortion.

Abstract: Deflection unit for use with a color display tube in which the line deflection coils are of the saddle type and have a front flange which is formed in such a way that a central portion has a part located closest to the axis of the display tube and being parallel to the surface of the display tube and a part located farthest away from the axis of the display tube and being transverse to the axis of the display tube, such that the north-south raster error is reduced.

Abstract: Method of continuously winding a saddle-shaped deflection coil flaring from a rear connection portion towards a front connection portion, in which at least one connection portion is given a convex shape during winding and in which after winding the convex connection portion is given a concave shape by means of a die, whereafter the coil turns are united to a compact assembly by means of a heating step.

Abstract: An electromagnetic deflection unit for use in a projection television display tube, includes: a system of line deflection coils having two oppositely located saddle coils each with their longitudinal conductor groups which are to be positioned on either side of the longitudinal axis of the display tube. At the screen-sided end the conductor groups of the oppositely located saddle coils are located at a first distance, on one side of the tube axis and on the other side they are located at a second, smaller distance from each other, whereas at the gun-sided end the situation is just the reverse. The distances at the screen-sided end are adjusted to generate a 4-pole component upon energization of the line deflection coil system, which component renders the raster to be written on the display screen trapezoidal. The distances at the gun-sided end are adjusted to generate a 4-pole component which is opposite to the 4-pole component generated in the proximity of the screen-sided end.

Abstract: A picture display device adapted for use in a projection color television receiver and comprising a monochrome display tube provided with a line deflection coil and a field deflection coil arranged contiguously in the direction of the tube axis, the line deflection coil being closer to the display screen of the picture tube. A convergence correction coil system is provided including a first convergence correction coil arranged coaxially with respect to the line deflection coil, one of such coils extending within the other, the first convergence correction coil generating a magnetic field at right angles to that produced by the line deflection coil. A second convergence correction coil is arranged coaxially with respect to the field deflection coil, one of such coils extending within the other, the second convergence correction coil generating a magnetic field at right angles to that produced by the field deflection coil.

Abstract: A color display tube deflection unit having an annular magnetizable core of tapered cylindrical shape and a raster distortion correction device comprising four pole shoes positioned at the corners of a rectangle adjacent the end of the core facing the display screen, the pole shoes respectively being near respective ends of a pair of vertical deflection coils. The four pole shoes are connected in pairs by respective bridging flux collector elements of soft magnetic material. The flux collector elements divert magnetic flux from the core which otherwise would not have emerged from the core, and such flux is conveyed to the pole shoes so as to cause the vertical deflection field to become pincushion-shaped adjacent the display screen.

Abstract: A combination of a monochrome cathode-ray tube with a deflection unit for applications which require high resolution. The deflection unit produces a magnetic field having a six-pole component which is positive on the screen side to minimize raster distortion and which, in the deflection center, has a strength and polarity sufficient to minimize spot distortion. Preferably the effective length 1 of the deflection field satisfies the conditon1.gtoreq.(0.2.tau..sup.2 +0.25)L,where L represents the distance between the deflection center and the display screen and .tau. is the tangent of the deflection angle of the electron beam for maximum deflection.

Abstract: During winding, the turns of the coil (9) are distributed over a number of sections (27, 29, 31) in which between each pair of adjacent sections an aperture (23, 25) is formed by providing, after winding the first section of the pair, pins (37, 38, 41) in the winding space around which the second section is wound. For the formation of at least one of the apertures (23) pins (38, 39) are provided in the winding space in at least two places on the same side of the plane of symmetry (43) of the coil so that said aperture obtains approximately the shape of a polygon having four or more sides.

Abstract: An electromagnetic deflection unit is disposed around a portion of a display tube and comprises a first deflection coil for producing, when energized, a frame deflection field and a second deflection coil for producing, when energized, a line deflection field the second deflection coil and being located coaxially within the first deflection coil, each deflection coil having two diametrically oppositely located deflection coil units.

Abstract: A hollow coil support for an electromagnetic deflection unit adapted to surround a part of a cathode-ray tube, the inside of the support carrying a deflection coil wound directly thereon, the support at each of its respective ends having a slotted annular member with groups of turns longitudinally extending from the slots in one annular member to the slots in the other annular member, and means provided between the ends of the support for locally supporting the longitudinal group of turns such that they are free from engagement with the inner surface of the support.

Abstract: A device for displaying television pictures comprising a display tube in the neck of which a gun system is present for emitting at least one electron beam towards a display screen, and comprising an electromagnetic deflection unit which is provided around the envelope of the display tube and which comprises a first deflection coil and a second deflection situated coaxially with respect to the first deflection coil, each having two diametrically oppositely located coil units.

Abstract: In a television deflection device which is mounted on a color cathode ray tube, a frustoconical supporting member (3) has a pair of coil halves (6) and (7) which form horizontal deflection coils halves. These coils have longitudinal portions (11, 12, 14 and 15) which extend to the front and the rear of the supporting member (3), an elongate tapered spacer (17) and (18) being inserted in the spaces between adjacent longitudinal portions of these coils. Movements of the spacers (17) and (18) adjust the space between the longitudinal portions which provides mechanical means for correcting for asymmetries in the display device.

Abstract: A color display tube having three electron guns situated in one plane for emitting three electron beams towards a display screen and having a deflection device which is mounted around a neck portion of the display tube and has a deflection yoke comprising: an annular core of a magnetizable material on which a field deflection coil toroidally is wound in such manner that its turns are located in planes passing through the longitudinal axis of the annular core. A dipolar field is generated in combination with a sixpole field resulting in a pin-cushion shaped overall field. To change the field at the rear end from the core from pin-cushion to barrel shape on the inside of the rear end of the annular core members of a magnetically permeable material are provided symmetrically with respect to the axis of the field deflection field.