Abstract: A color cathode ray tube equipped with an in-line type electron gun, a deflection yoke designed to generate a uniform deflection magnetic field, the in-line type electron gun having a focusing grid which accommodates three pole pieces of magnetic bodies, and a magnetic field generator disposed outside the cathode ray tube so as to apply 4-pole dynamic magnetic fields to the pole pieces, thus constituting a dynamic convergence system capable of correcting any misconvergence of the three electron beams in a vertical direction or a horizontal direction.

Abstract: A color cathode ray unit which includes an in-line type electron gun, a deflection yoke disposed on the color CRT so as to generate substantially uniform horizontal and vertical deflection magnetic fields, thereby ensuring that an axially unsymmetrical lens electric field is dynamically generated between a first and a second focusing grid thereby correcting a distortion of electron beams caused by a magnetic field leaking from a dynamic convergence means.

Abstract: An in-line type electron gun used in a color cathode ray tube apparatus, the electron gun comprising a focusing grid, a final accelerating grid adjacent to the focusing grid, these grids having elongated cylindrical apertures having their majors extending horizontally, a field correction metal plate located in each grid along the elongated aperture, the field correction metal plate having three apertures produced in an in-line arrangement, wherein the central aperture is elongated with a major extending vertically, and the two apertures on each side are circular, the horizontal diameter L.sub.s and the vertical diameter .phi..sub.v having a ratio .phi..sub.v /L.sub.s of 0.49 to 0.6.

Abstract: The invention provides an in-line electron gun in which first astigmatic lens fields that are convergent in a horizontal direction and divergent in a vertical direction are produced between a first focusing grid and a second focusing grid, and second astigmatic lens fields that are divergent in a horizontal direction and convergent in a vertical direction are produced upstream of the first focusing grid. The lens magnifications in both horizontal and vertical directions can be made substantially equal, so that it is possible to achieve a satisfactory resolution over the entire area of the phosphor screen and also to prevent moire occurrences.