U.S. Philips Corporation

Marinus L Vrinten

Albertus A Sluyterman

Jacobus J Ruigrok

Lambert J Stil

Fransiscus M Doomernik

Andre A Verhulst

Casper M Smit

An element of an apparatus is magnetized so as to generate a magnetic field pattern around the element. To achieve this, use is made of a magnetizing coil, and the element and the magnetizing coil are moved relative to each other, the magnetizing coil carrying an alternating current of substantially constant amplitude as well as a signal current. Preferably, there is a phase difference between the signal current and an intended magnetic field pattern.

Method of manufacturing a magnetic device

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.

Picture display device

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.

Color display tube system with reduced spot growth

A color cathode ray tube system comprising three coplanar electron guns and one deflection unit. A dynamically controlled element driving the outer electron beams away from each other is arranged at the input side of the deflection unit. The underconvergence induced thereby is compensated in that the deflection unit generates deflection fields which cause an overconvergence of the outer beams. This leads to a reduction of the spot growth upon deflection.

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Eindhoven, Netherlands

Marinus L Vrinten