| 摘要 |
1532462 Colour television tubes PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 10 March 1976 [13 March 1975] 09522/76 Heading H1D A static convergence device mounted about the neck of a three coplanar beam colour television tube comprises at least two annular magnetic structures which enclose the neck of the tube but are eccentrically arranged with respect to each other and to the longitudinal axis of the tube, and each of which generates a six-pole magnetic field, whereby the beams may be adjusted substantially independently of each other. As described, two structures are arranged one at each mid-point between the centre beam and a side beam, each structure (Figs. 3 and 4, not shown) being in the form of a pair of six pole annular magnetic rings (47, 49 and 46, 48, respectively) rotatable with respect to each other to adjust the corresponding side beam. In an embodiment employing electromagnets (Figs. 5, 6 and 7, not shown), independent horizontal and vertical adjustment of each outer beam is obtained by the use, for each structure, of a ring having 12 pole shoes, the coils of which are wound to form two independently energized 6-pole systems, angularly displaced through 30 degrees. |
