Deflection yoke arrangement with overlapping deflection coils

A television display tube deflection coil system, comprising:

• a saddle shaped primary deflection coil and an auxiliary deflection coil having a forward flat end turn section,
• said primary deflection coil operable to produce an electron beam deflection field having a first polarity within a first region defined by that coil and an opposite polarity in a second region,
• said auxiliary deflection coil also operable to produce an electron beam deflection field having said first polarity in a first region and said opposite polarity in a second region that is substantially defined by its flat end section;
• said auxiliary deflection coil being positioned along a tube axis to the rear of said primary deflection coil with said flat end turn section partially overlapping said primary deflection coil to thereby cross couple part of the first polarity field regions and all of the opposite regions for substantially cancelling cross coupling between the primary and auxiliary deflection coils.

A scanning electron beam display, comprising:

• a tube defining a neck and an envelope, at least one electron gun being disposed in a neck of the tube and operable to produce a beam of electrons to be accelerated through the neck and through the envelope toward a display surface at an opposite end of the tube;
• at least one primary deflection coil for deflecting said beam in at least one of two mutually perpendicular directions on the display surface, the primary deflection coil having a saddle shaped configuration and being mounted on the envelope of the tube, for producing a primary magnetic field perpendicular to the beam of electrons;
• at least one auxiliary deflection coil having a saddle shaped configuration and being mounted on the neck on a common axis with the primary deflection coil, the auxiliary deflection coil producing an auxiliary magnetic field substantially parallel to that of the primary deflection field, centered at a point spaced therefrom along the common axis;
• at least one of said primary and auxiliary deflection coils being arranged to produce a magnetic field of a first polarity in the tube and a supplemental field of an opposite polarity at an end of the coils along the axis of the tube, said primary and auxiliary deflection coils being mounted relative to one another on the tube such that the supplemental field of said coil couples to the other coil, whereby coupling between said primary and secondary deflection coils at the first polarity is substantially cancelled.