Abstract: A cathode ray tube including an electron gun including a cathode and a plurality of electrodes and for generating an electron beam, a phosphor screen and an electron beam deflection device. The cathode ray tube includes a deflection-defocusing correcting member having laminated nonmagnetic and magnetic materials disposed in a deflection magnetic field produced by the electron beam deflection device for establishing at least one non-uniform magnetic field. The magnetic materials are disposed at positions with respect to a path of the electron beam where a magnetic flux density of said deflection magnetic field is more than five per cent of a maximum magnetic flux density of the deflection magnetic field.

Abstract: A color cathode ray tube includes an electron gun having a plurality of electrodes, an electron beam deflection device and a phosphor screen. A deflection defocusing correcting element is located in a deflection magnetic field produced by the deflection device to locally modify the magnetic field in a path of an electron beam and corrects the deflection defocusing of the electron beam corresponding to deflection of the electron beam. The deflection defocusing element includes the magnetic metal plate providing magnetic pole pieces and a non-magnetic metal support for holding the magnetic metal plate in place. The magnetic metal plate and the non-magnetic metal support are laminated or clad one on another, or joined edge-to-edge.

Abstract: In a color cathode ray tube having an inline electron gun, an electrode geometry asymmetric in the inline direction is provided on the two side beam apertures in the first grid electrode for the two side beams on the side facing the cathode such that as the electron beam current through the side beam apertures decreases, the degree of an asymmetry in the inline direction in a distribution of an electric field between the side beam apertures and the cathodes increases.