PROCESS AND APPARATUS FOR MAGNETIZING A MAGNETIC RING FOR STATIC CONVERGENCE CORRECTION IN A CRT

摘要

A process and apparatus are described for custom magnetizing a magnetic ferrite ring on the outside of the neck of a color cathode ray tube (CRT), in order to provide correction of convergence, color purity and frame errors in the CRT. The two step process provides for a first coarse correction step and a second fine correction step, each step involving bringing the ring to an initial state of magnetic saturation, and then custom magnetizing the ring using a series of high power AC pulses and low power DC offsetting fields, via cylindrical coils positioned around the periphery and in close proximity to the ring.