Thomson Tubes & Displays, S.a.

Thomson Licensing S.a.

Thomson Licensing

Thomson Tubes & Displays

Nacerdine Azzi

Olivier Masson

Sebastien Volatier

Sébastien Volatier

Céline Cossu

Jean-Philippe Descombes

Mohamed Massaoudi

Electromagnetic deflection unit for colour cathode-ray tubes, including a pair of frame deflection coils and a pair of line deflection coils, at least one of these two pairs of coils having the shape of a saddle, each saddle-shaped deflection coil having a rear bundle placed on the side facing the electron gun and a front bundle placed on the side facing the screen, two lateral harnesses of conductors connecting the front bundle to the rear bundle, each lateral harness being characterized in that the external edge of the said lateral harness lies in a radial angular position close to 0&#xb0; at the rear of the coil and in a radial angular position greater than 5&#xb0; at the front of the coil, so as to minimize the trapezoid differential error between the red and blue beams.

Deflection unit for self-converging cathode-ray tubes with reduced trapezoid differential

The invention is a color cathode-ray tube having a rectangular front face connected to a funnel shaped rear part, a neck connected to the rear part and having an electron gun therein, the gun is used to generate beams intended to scan the front face under the influence of a deflection device placed on the neck of the tube. The deflection device comprising correction magnets placed on the periphery of the device in locations closest to the front face and a magnetic screen within the tube having an opening for passage of the electron beams, wherein the opening has notches in its periphery. The notches are arranged so as to face at least one pair of correction magnets.

Color cathode-ray tube having internal magnetic screening

Deflection yoke for cathode-ray tubes with a north/south geometry correction comprising a pair of horizontal deflection coils and a pair of vertical deflection coils, the two pairs being isolated one from the other by a separator, a ferrite ring at least partly covering the deflection coils and having a flared front part, the deflection yoke comprising in its front region at least one pair of magnetic means to modify locally the magnetic field in the said front region and to correct the geometry of the image created on the screen of the tube, the magnetic means being placed in the space in such a way that, for a plane containing the longitudinal axis of the deflection yoke and the axis of symmetry of a magnetic means, and for the point M of the plain corresponding to the point of minimum coordinates of the said means, the intersection of the ring with is at least partly in its front part, located outside the region delimited by the half line passing through M and perpendicular to Z, and the half line passing through M and making an angle of 45&#xb0; with.

Magnetic device for correcting image geometry defects for cathode-ray tubes

Deflection yoke for a cathode-ray tube has at least one pair of saddle-shaped coils. The saddle-shaped coils form an asymmetric field in the vicinity of a front conductor assembly. The field asymmetry is produced by an inclusion near the front conductor assembly of at least a metal piece. The purpose of this asymmetry is to minimize the effects of an orthogonality defect between the deflection fields created by the horizontal and vertical deflection coils on the geometry of the image.

Asymmetric shunt for deflection yoke for reducing diagonal symmetric defects

Deflection coil of a deflection yoke

Deflection coil having a winding window

A deflection yoke mounted on a neck of a cathode ray tube includes a pair of horizontal deflection coils, a pair of vertical deflection coils and a core of a ferromagnetic material. The core has magnetic reluctance, in a front region, close to a screen end of the tube, that is greater along the vertical direction than along the horizontal direction. In one embodiment of the invention this feature is achieved by making recesses at the intersection of a flared front part of the core with the horizontal plane of symmetry XZ. In another embodiment of the invention, the thickness of the core varies.

Deflection yoke for a cathode-ray tube with both improved geometry and convergence

A video display deflection apparatus includes a vertical deflection coil. A separator is used for mounting the vertical deflection coil thereon. The separator has a funnel shaped first part conforming to a shape of a neck of the cathode ray tube and a second part forming a front portion of the separator close to the screen. A degree of flare of the first and second parts is substantially different. A saddle shaped, horizontal deflection coil is mounted on the separator for producing a deflection field to scan the electron beam along a horizontal axis of the display screen. The horizontal deflection coil includes a plurality of winding turns forming a pair of side portions, a rear end turn portion, close to an electron gun of the tube and a front end turn portion, close to the screen. At least a portion of the front end turn portion, in a radial angular position ranging between 0 and 30 degrees, is supported on the second part of said separator away from the boundary. Consequently, an effective length of the horizontal deflection coil is extended in a direction of the screen to provide north-south raster distortion correction. A magnetically permeable core cooperates with the deflection coils to form a deflection yoke free of permanent magnets upfront.

Deflection yoke with geometry distortion correction

A deflection yoke for a cathode-ray tube of a video display, includes a pair of horizontal deflection windings and a pair of vertical deflection windings. The pair of vertical deflection windings includes a saddle-shaped winding. The saddle-shaped winding includes a front end winding portion, close to a screen of the cathode ray tube, a rear end winding portion, remote from the screen and a pair of side winding portions, between the front and rear end portions. The saddle-shaped winding is disposed generally symmetrically with respect to a plane of symmetry. A depression or notch is formed in the front end winding portion for varying a winding distribution locally. The depression or notch forms asymmetry with respect to the plane of symmetry.

Asymmetry forming arrangement in a deflection winding

Saddle shaped deflection winding having a winding space within a

Saddle shaped deflection winding having winding spaces in the rear

Saddle shaped deflection winding having a winding space

An electron beam deflection device for cathode ray tubes comprises a pair of vertical deflection coils, a pair of horizontal deflection coils. At least one of the vertical deflection coils and the horizontal deflection coils has a saddle shape. A rigid separator supports the deflection coil pairs and insulating one from the other. An attachment element is coupled to the separator for securing the separator to a neck portion of the tube. The attachment element has a position on the neck and extends into a region under the vertical deflection coil pair.

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Nacerdine Azzi