Abstract: In a self-convergent type color cathode ray tube apparatus, three in-line electron beams emitted from an electron gun assembly are deflected by non-uniform magnetic fields generated by a deflection yoke and thus self-converged onto a screen. The electron gun assembly has a second grid and a third grid. First and second auxiliary grids are disposed between the second and third grids. A dynamic voltage varying in synchronism with deflection of the electron beams is applied to the first auxiliary grid situated on the second grid side. A fixed voltage is applied to the second auxiliary grid situated on the third grid side. Accordingly, the second grid, the first and second auxiliary grids and the third grid form an electron lens such that a higher astigmatism is provided by focusing in a direction perpendicular to a direction of arrangement of the three electron beams than by focusing in the direction of arrangement of the three electron beams and the degree of the astigmatism is dynamically varied.

Abstract: A color cathode-ray tube apparatus comprises an electron gun structure for generating three electron beams arranged in line, the three electron beams comprising a center beam and a pair of side beams. The electron gun structure forms a main lens for ultimately focusing the three electron beams on a phosphor screen. The main lens is formed by a focus electrode, an additional electrode and an anode electrode which are arranged in a direction of traveling of electron beams.

Abstract: A cathode structure comprises a cathode, a cathode sleeve, a cathode holder and a cathode strap. The cathode sleeve contains a heater. A hold structure includes a cylindrical cathode support cylinder for holding the cathode structure, and a cathode support strap having an elongated plate shape and having a cylindrically curved portion engaging the cathode support cylinder. An opening portion is formed in the cylindrically curved portion of the cathode support strap. The cathode support cylinder of the hold structure and the cathode holder of the cathode structure are welded through the opening portion, and the cathode structure is held by the hold structure.

Abstract: In an electron gun for a color cathode ray tube apparatus of this invention, one intermediate electrode is arranged between a final acceleration electrode and a focus electrode that make up a main lens, and a voltage divided by a voltage dividing resistor for dividing a voltage to be applied to the final acceleration electrode is applied to the intermediate electrode. A dynamic voltage which increases along with an increase in deflection amount of an electron beam is applied to the focus electrode, and a dielectric portion is formed between the final acceleration electrode and the focus electrode. This dielectric portion is formed on the intermediate electrode. Hence, elliptical distortion of electron beam spots is decreased on the entire surface of a phosphor screen, thereby providing a color cathode ray tube apparatus with a good performance on the entire surface of the phosphor screen.

Abstract: An electron gun comprises a supplementary grid applied with a voltage which dynamically changes in synchronization with a magnetic field generated by a deflection yoke, between a second grid and a third grid. Further, by the second grid, the supplementary grid, and the third grid, an electron is constructed which has an astigmatic aberration in which a focusing force in the horizontal direction is stronger than a focusing force in the vertical direction. The intensity of the astigmatic aberration of the electron lens is dynamically changed by a voltage applied to the supplementary grid.