Thomson Tubes & Displays, S.a.

Thomson Licensing S.a.

Thomson Licensing

Thomson Tubes & Displays

Olivier Masson

Nacerdine Azzi

Sebastien Volatier

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

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

Deflection yoke with saddle-shaped vertical deflection coils

In a deflection yoke four Gorner magnets are used for correcting inner north-south raster distortion. The north-south axis of each of the comer magnets is disposed in parallel to the Z-axis.

Growing community of inventors

Cuisery, France

Olivier Masson