Deflection yoke with a magnet for reducing sensitivity of convergence to yoke position

A self-converging deflection yoke assembly for use with a wide-angle in-line color television kinescope, comprising:

• means for producing deflection fields having a nonzero average nonuniformity for substantially converging the electron beams at all points on the raster, and also having a region about the entrance end of said yoke in which the average field nonuniformity is substantially zero for reducing the effect of yoke positioning relative to said electron beams, wherein said means for producing deflection fields comprises:
• a deflection winding for producing a magnetic field having a time-variant amplitude for progressive deflection of said electron beams;
• and
• first static magnetic field producing means disposed near said entrance end of said yoke for producing a static magnetic field which sums with said time-variant magnetic field in such a manner as to produce a time-variant field distribution in the vicinity of said entrance end of said yoke in which said average field nonuniformity is substantially zero, wherein said first static field producing means is disposed adjacent said deflection winding along the inside flare of said yoke and comprises a first magnet disposed near said entrance end of said yoke, and wherein said first static field producing means comprises a second permanent magnet disposed adjacent said deflection winding along the inside flare of said yoke diametrically opposite said first magnet.

A self-converging deflection yoke assembly for use with a color television kinescope, comprising:

• a horizontal deflection winding for producing a horizontal deflection field having an average positive nonuniformity function;
• a vertical deflection winding for producing a vertical deflection field having an average negative nonuniformity function coacting with said horizontal deflection winding for producing substantial convergence of the kinescope electron beam at all points on a raster;
• and
• means coupled to said yoke for altering said deflection fields to reduce the average nonuniformity of one of said horizontal and vertical deflection fields in the region of the beam-entrance end of said yoke for reducing the sensitivity of said convergence to the position of said yoke relative to said electron beams.

A self-converging deflection yoke assembly for use with a color television kinescope, comprising:

• a pair of horizontal and a pair of vertical deflection windings;
• first magnetic field producing means disposed about said windings for producing fields near the top and the bottom of the beam-exit end of the yoke which fields are of the same polarity as the field produced by said vertical windings during those intervals in which the electron beams are deflected towards the top and bottom, respectively, of said yoke;
• second magnetic field producing means disposed at the top and bottom of the inside flare of said yoke adjacent said windings at a position between the beam entrance and said beam exit ends of said yoke for adding a barrel-shaped component to said field produced by said vertical windings for correcting raster distortion in conjunction with said first field producing means;
• and
• third magnetic field producing means disposed at the top and bottom of said inside flare at a position between said beam entrance end of said yoke and said second field producing means for adding a pincushion-shaped component to said field produced by said vertical windings for reducing the sensitivity of the convergence to the path of said beams relative to said yoke.