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Variable Shape Bore Stator Type Deflection Yoke for Cathode Ray Tubes

IP.com Disclosure Number: IPCOM000037911D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-30
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Beck, VD: AUTHOR [+2]

Abstract

The field harmonic content for stator type yokes can be shaped by varying the shape of the bore of the yoke.

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Variable Shape Bore Stator Type Deflection Yoke for Cathode Ray Tubes

The field harmonic content for stator type yokes can be shaped by varying the shape of the bore of the yoke.

If the bore of a ferrite stator is varied from its nominal circular shape, the magnetic field in the bore will be changed for a fixed distribution of current through the winding in the slots. The bore can be made elliptical by radially moving the position of the stator pole tips and the dipole component of the field will be altered. This distortion of the bore is equivalent to radially moving the pole tips of the stator by an amount proportional to the cosine of twice the polar angle about the axis (second harmonic). If one distorts the bore by adding a radial component onto the pole tips which is proportional to the cosine of the fourth harmonic, a hexapole component will be introduced into the field. This makes the bore of the yoke take on a somewhat square shape. Likewise, pole tip displacement proportional to the cosine of the sixth harmonic introduces a decapole field component and the pole tip displacement proportional to the cosine of the eighth harmonic introduces a 14-pole field. These two harmonics cause the bore to take on a slightly hexagonal or octagonal shape respectively. While only the cosines of the even harmonics have been considered, there are other radial displacements which can alter the underlying symmetry of the yoke. These may be useful for systems which require n...