DEVIATION SYSTEM FOR CATHODE RAY TUBES ADAPTED TO CONTROL THE NORTH / SOUTH GEOMETRY OF IMAGE

摘要

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 (3) is mounted on the separator (2) for producing a deflection field to scan the electron beam along a horizontal axis of the display screen (9). The horizontal deflection coil includes a plurality of winding turns forming a pair of side portions, a rear end turn portion (19), close to an electron gun of the tube and a front end turn portion (29), close to the screen (9). 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 (5) cooperates with the deflection coils to form a deflection yoke free of permanent magnets upfront.