Apparatus for compensating convergence in a color cathode ray tube

Abstract

This invention relates to an apparatus for compensating convergence in a color cathode ray tube, more particularly to an apparatus for minimizing the convergence drift variance of R and B electron beams on a screen so as to improve convergence characteristics and a picture quality on the screen. The apparatus for compensating convergence drift comprising: a convergence purity magnet for converging the electron beams emitted from the electron gun on the specific point of the screen of the color cathode ray tube; and a supplementary magnet ring 52 with at least four-magnetic pole contacting the neck N between a second grid electrode 24 and the deflection yoke 60. Particularly, the supplementary magnet ring is mounted on a holder 48 of the convergence purity magnet 40 and has a pole arrangement to move the convergence of the R and B beams in the direction opposite to the electron gun from the screen.

Dependencies are inferred from the claim text.