Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Antonius Henricus Van Tiel

Leopold Cyrille Maria Beirens

Nicolaas G Vink

Tjerk G Spanjer

Dirk Willem Harberts

Albertus Aemilius Seyno Sluyterman

Hans Meershoek

Albertus Aemilius Seyno Sluijterman

The invention relates to a color display device comprising an electron gun () for generating three electron beams (), and convergence means () for dynamically influencing the convergence of the electron beams. The convergence means () comprise coils () for generating a magnetic field. The coils () are provided with an electrically conducting layer.

Cathode ray tube with convergence unit

A color display device having an in-line electron gun ( ) for generating three electron beams ( ), and a convergence unit ( &prime;) to dynamically influence the convergence of the electron beams, preferably to decrease a distance (p) between the electron beams. The convergence unit ( &prime;) includes a ring-shaped element ( &prime;) having coils ( &prime;) formed by 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;)&equals;N cos ( &phgr;)&plus;C where &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&deg; and 360&deg;, N is a given winding density, the sign of N (&phgr;) denotes the winding direction, and C is a constant different from zero, and preferably equal to &minus;N .

Color display device having quadrupole convergence coils

The invention relates to a color display device comprising an in-line electron gun ( ) for generating three electron beams ( ), a deflection unit ( ) for deflecting the electron beams ( ) and a convergence unit ( &prime;) for dynamically influencing the convergence of the electron beams. A variable transformer ( ) is connected between the convergence unit ( &prime;) and the deflection unit ( ) for compensating undesired voltages induced by the deflection unit ( ). The variable transformer ( ) comprises three coils ( ) wound around a hollow coil holder ( ) and an adjustable core ( ), which moves within the coil holder.

When, for example, horizontal lines are displayed on a display screen of a display device, they may exhibit a field distortion, predominantly in the form of gullwing distortion which becomes manifest as a sinewave-shaped line instead of the horizontal line to be displayed. To correct this field distortion, a correction is generated by a field distortion correction circuit and a resonant circuit, dependent on the location on the display screen, which correction is added to the field deflection current so that the picture to be displayed is corrected for this error.

Display device including a field distortion correction circuit, and

A cathode-ray tube and deflection system suitable for a cathode-ray tube. A cathode-ray tube having a deflection system, comprising two switched line deflection coils, a coil being arranged between the deflection coils, and a line deflection system suitable for a cathode-ray tube. The coil reduces the occurrence of 'ringing' on the picture screen without necessitating a modification in the design of the deflection system or the enivonment of the deflection system.

Cathode-ray tube with deflection system

A cathode ray tube electromagnetic deflection unit comprising a support (4) having a flange (8) at its constricted end (5) which has a tangential groove into which radial grooves (14) merge. Two sets of deflection coils (18, 19) are wound on the support (4), the turns thereof running through the radial grooves (14) and the turns of one set bending into the tangential groove. The coils of the coil system 18 are for line deflection, and the two halves thereof are wound in the opposite winding sense and are energized during operation in such a manner that the highest voltage in both coils occurs at the coil turns adjacent plane of separation between the two coils and the lowest voltage occurs at the coil turns most remote from such plane of separation.

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Eindhoven, Netherlands

Antonius Henricus Van Tiel