Videocolor, S.a.

Videocolor

Jean-Pierre Fourche

Eric Audoux

Alain Dossot

Marc Milili

Jean Rousseau

Michel Faivre

Guy Legrand

Olivier Berthaut

Bernard Priere

Dimples or depressions are formed in a deflection coil for a CRT deflection yoke assembly by inserting a spherically shaped end of a dowel-like pin through a hole in the wall of a female arbor, to protrude into a winding cavity formed between a male arbor and the female arbor of the associated yoke coil winding machine. The pin end is inserted only partially into the cavity, for acting as a deformation in the wall of the female arbor, thereby causing convolutions of wire being wound around the cavity to overly the pin. This creates the desired dimple or depression, and controls the distribution of the wires in that area of the deflection coil.

Saddle coil deflection winding, apparatus and method of making thereof

A scan velocity modulation (SVM) coil arrangement for a cathode ray tube has SVM coils arranged on a rear portion of the main horizontal deflection coils. The main horizontal coils are of the saddle type and have flat end turns at the rear of the deflection coil, lying along the surface of the picture tube. The SVM coil is placed over the flat rear end turns forward of the static convergence magnets and forward of ferromagnetic materials associated with the electron gun. The sensitivity of the SVM coil is increased to the point that the coil can be efficiently driven in a progressively scanned raster display, at twice the horizontal rate of an interleaved raster display.

Scan velocity modulation apparatus

This invention relates to a deflection arrangement for a video display of color pictures. The arrangement comprises a deflection yoke including a pair of vertical deflection coils toroidally wound on a magnetic core, using a multi-layer terminal technique. An R-C network is coupled between an intermediate terminal of the firstly wound layer of one of the coils and between an intermediate terminal of the firstly wound layer of the other one of the coils. The R-C network suppresses ringing in the coils that are produced by a horizontal deflection coil during horizontal retrace.

Deflection yoke with ringing suppression means

To avoid the use of adhesives or notched parts when winding the non-radial layers of a cathode tube deflector, first a radial layer with a wide pitch is wound. This first radial layer then presents notches for winding the folllowing layers of the non-radial coil.

Winding method for the non-radial winding of a cathode tube deflector

A deflection yoke arrangement with geometry correction includes horizontal and vertical deflection coils for scanning a raster pattern on a phosphor screen of a cathode ray tube. A support housing suitable for positioning about the neck of the cathode ray tube contains the coils and has a front rim formed with a plurality of slots near the outer periphery. A plurality of brackets formed from magnetically permeable material are located in corresponding ones of the slots. Each bracket comprises two flat end sections joined to opposite sides of a flat central part at substantially right angles thereto. One of the flat end sections of each bracket collects magnetic flux generated by the coils and channels the flux via the central part to the other end section. The plurality of brackets shape the deflection magnetic field in the region about the front rim to provide the geometry correction.

Geometry correction device for cathode ray tubes

For the automatic determining of the characteristics of the corrections to be made in trichromatic cathode tube deflectors, measurements are made of the coordinates of the midpoints of the bars R and B of a crossed bar test pattern at 'strategic' places. With the deflector in the 'mean' position on the tube, the values obtained are standardized by computation to re-establish virtually the ideal position of the deflector, the convergence errors due to this deflector are computed and the pinpoint or overall corrections to be made to it are deduced therefrom.

Method for the automatic measurement of convergence and for the

A deviator associated with an autoconvergent color image tube is modified so that it may be used in combination with a tube of the same type, but having an image screen of smaller size, the horizontal and/or vertical deviation center being displaced. According to the invention, a magnetic screen is placed across the magnetic field lines produced by the vertical and horizontal deviation coils whereby the deviation centers are displaced without any modification of the coils.

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Dijon, France

Jean-Pierre Fourche