| 摘要 |
Each convergence device is particularly adapted for converging the three electron beams of an in-line picture tube. Each convergence device comprises a mounting sleeve having an axial opening for receiving the neck of the picture tube, and a plurality of beam adjusting assemblies mounted around the supporting sleeve. Each beam adjusting assembly may comprise a rotatable supporting ring, a pair of rotatable magnet rings stacked upon the mounting ring, the magnet rings having integral bevel gears facing toward each other, a radial shaft having a bevel pinion meshing with such gears, and a member on the supporting ring and rotatably supporting the shaft. Each magnet ring is formed with permanent magnetic poles. The orientation of the poles can be varied by rotating the entire beam adjusting assembly about the axis of the picture tube. The effective strength of the poles can be adjusted by rotating the shaft, which causes rotation of the magnet rings in opposite directions. In one embodiment, there are two such beam adjusting assemblies, plus a third similar assembly in which the supporting ring is replaced by a flange on the mounting sleeve. In a second embodiment, there are three of the rotatable beam adjusting assemblies, which are stacked and pressed together by springs. A clamping device produces increased clamping pressure between the adjusting assemblies to retain the adjustment thereof.
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