TOROIDAL ELECTROMAGNETIC DEFLECTION YOKE

摘要

1299491 Electron beam deflecting apparatus RCA CORPORATION 4 March 1970 [7 March 1970] 10341/70 Heading H1D A toroidally wound deflection yoke for providing beam deflection in a multi-beam colour TV tube (e.g. delta gun shadow mask tube) while maintaining substantial convergence of the beams over the raster, comprises an annular core and a pair of orthogonally acting beam deflection windings symmetrically disposed about respective symmetry axes, each wound with substantially constant winding progression, wherein each winding comprises in each quadrant a first portion extending from the axis through a first angular segment and a second winding portion extending from that axis through a second angular segment of different angular extent to the second segment, the angular extensions and winding distributions being selected to produce a deflecting field which also provides convergence of the beams. In Fig. 4, the horizontal and vertical windings are 21a and 21b respectively. The ferrite core 22 may have grooved plastic rings (23), (24) (Fig. 2, for example), the front and rear grooves having a 1 degree and 2 degree separation, respectively, the conductors overlapping at the rear (Fig. 3, not shown), but not at the front of the core (Fig. 5, not shown), the separate horizontal and vertical coil windings being subsequently formed by cutting, peeling and interconnecting appropriate conductors, the interconnections being as indicated in Fig. 6 (not shown) with Fig. 4. Convergence errors may be minimized manipulating only four parameters # 1V , # 2V , # 1H , # 2H , equations being given, constants of which are determined by measuring convergence errors for five winding distributions, or more than five windings to minimize the influence of any measurement error. Matrix equations may be utilized to solve simultaneously for minimum convergence errors existing in more than one direction. Specific distribution angles and core sizes are given using No. 23 copper wire. # 1 and # 2 may be so large as to effect overlapping in three layers and three or more parameters corresponding to one or more additional stairsteps may be used. A red, green, blue phosphor dot screen is instanced.