Process and apparatus for the rapid adjustment of the static convergence and purity in a television tube, by using a permanent magnet

摘要

Process for adjusting the static convergence and/or purity of a color television tube by using a magnetic ring surrounding the neck of the tube and coils creating in this ring induction poles of values selected to carry out the adjustment. To the terminals of each coil a current impulse is applied conferring on the remanent induction an important value higher than that necessary to carry out the correction; then a current impulse is applied in the opposite direction effecting a partial demagnetization in such a way that the remanent induction allows the desired adjustment.