Abstract: A cathode ray tube device in which two deflection yokes and two electron guns are used, but in which only one shadow mask is used. Image uniformity is obtained by creating a partial overlap of the two images created by the two yokes.

Abstract: A color display device having an electron gun, a display screen, a color selection electrode and a deflection unit. The distance between the electron beams in the x-direction is dynamically varied, whereby the distance in the deflection space decreases as the beams are deflected in at least one direction. The reduction of the distance enables the distance between the color selection electrode and the display screen to be increased in that direction. As a result, the curvature of the color selection electrode is increased, which has a positive effect on the strength and the doming and microphonic properties of the color selection electrode.

Abstract: A cathode ray tube device in which two deflection yokes and two electron guns are used, but in which only one shadow mask is used. Image uniformity is obtained by creating a partial overlap of the two images created by the two yokes.

Abstract: A cathode ray tube device in which two deflection yokes and two electron guns are used, but in which only one shadow mask is used. Image uniformity is obtained by creating a partial overlap of the two images created by the two yokes.

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: Color display device with a deflection-dependent distance between outer beams. A color display device comprises an electron gun, a display screen and a color selection electrode as well as a deflection means. The distance between the electron beams is dynamically varied, whereby the distance in the deflection space decreases as the beams are deflected in at least one direction. The reduction of the distance enables the distance between the color selection electrode and the display screen to be increased in that direction. As a result, the curvature of the color selection electrode is increased, which has a positive effect on the strength and the doming and microphonic properties of the color selection electrode.

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: A color display device comprises an electron gun, a display screen with a curved inner surface and a flat color selection electrode as well as a deflection means. The distance between the electron beams is dynamically varied, whereby the distance in the deflection space increases as the beams are deflected in at least one direction. The reduction of the distance enables the distance between the color selection electrode and the display screen to be decreased in that direction. As a result, the curvature of the inner surface of the display window is increased, which has a positive effect on the strength and weight of the display window.

Abstract: A color cathode ray tube is provided with a saddle-shaped shadow mask.As a result, the sensitivity to doming and microphonics of the mask is improved. This is advantageous, in particular, for a cathode ray tube having a very flat display window. Preferably, the display device in which the cathode ray tube is employed is provided with two dynamic quadrupoles, for example, in front of the electron gun and in front of a deflection unit.

Abstract: A color display device having a color display tube with a display screen, comprising an electron gun for generating three co-planar electron beams, and a deflection system which, in operation, generates deflection fields for scanning the display screen, and an element influencing the landing angle of the outermost beams, for example an element generating, in operation, a 45.degree. magnetic 4-pole field, and comprising a correction device which supplies a signal to the element influencing the landing angle, which signal is derived from the video information (for example a signal which is proportional to the strength of the instantaneous beam current) in order to remedy landing errors caused by space-charge repellence between beams.

Abstract: A method for improving brightness uniformity reduces a decrease of light towards the edges of a display screen (10) of a display tube (1). The extent of the decrease of light particularly depends on an increase of the thickness of the glass of the display screen (10) from the center of the display screen (10) to its edges, and on a transmission of the glass. This decrease of light is corrected by causing the deflection rate to decrease (C1, Cs) from the center of the display screen (10) towards its edges.

Abstract: In a method of reducing a moire phenomenon upon display of a video signal on a display device (4), the video signal is low-pass filtered (2) with a cut-off frequency substantially corresponding to a maximum frequency of a baseband portion of the video signal, to obtain a low-pass filtered video signal. The low-pass filtered video signal is filtered (3) in accordance with a transfer function substantially corresponding to the inverse of the transfer function of the display device, to obtain a filtered signal. Finally, the filtered signal is applied (3a) to the display device (4).

Abstract: The display system comprises a colour cathode ray tube. The colour cathode ray tube comprises an in-line electron gun with a distributed main lens (DML). The final electrode (anode) of the DML generates a quadrupole lens field. To a first electrode a static voltage V.sub.foc is applied. Between a second electrode, on which a dynamic voltage V.sub.dyn is applied, and a first intermediate electrode a quadrupole electric field is generated. The value of the dynamic voltage is lower than the static voltage.

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: An electromagnetic deflection unit (5) comprising a coil holder (6) with a flange (8) whose inner side supports coils (10a, 10b) for (line) deflection of electron beams. At the flange side of the coil holder (magnetized) preformed elements (14) are arranged within these coils so as to influence the magnetic field of these coils (10a, 10b), thereby reducing spreading errors, caused during manufacture, throughout the display screen. For the purpose of automatic mounting of the preformed elements, an annular support having predetermined locations (in particular from 12 to 36) for accommodating preformed elements is used. The preformed elements (14) are accommodated at a plurality of these predetermined locations and, if made of a permanent magnetic material, produce magnetic fields having magnetic strengths measured at a distance of some mm above the heart of the elements in the range between 1 and 1000 .mu.T.

Abstract: Color display tube comprising an electron gun system (5) of the "in-line" type and an electromagnetic deflection unit. This unit is provided with coma correctors 14 and 14' at its gun side, which correctors, viewed from the gun system, provide a pincushion-shaped vertical deflection field component and a barrel-shaped vertical deflection field component. These components are used to reduce the "green droop" (=anisotropic Y coma) in the corners and at the ends of the display screen axes to an equal extent without the spot shape of the outer beams being influenced detrimentally.

Abstract: Color display tube comprising an electron gun for producing three co-planar electron beams, and including a deflection system which, in operation, generates deflection fields of the self-convergent type, with three consecutive elements influencing convergence being arranged between the electron gun and the display screen, the two outer elements producing, in operation, opposite effects and the central element being energizable for correcting remaining convergence errors.

Abstract: Picture display device comprising an in-line color display tube having an elongate display screen with a short axis and a long axis, which screen is provided on an inner surface, and a deflection system. The plane in which the undeflected electron beams are located is parallel to the short axis of the display screen. The deflection system comprises a first system of deflection coils for generating a substantially pincushion-shaped deflection field in the direction of the short axis of the display screen and a second system of deflection coils for generating a substantially barrel-shaped deflection field in the direction of the long axis of the display screen. The deflection system has terminals to be connected to a signal generator for scanning the display screen in a raster having a plurality of lines oriented along the short axis of the display screen.

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: 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.