Patent ID: 6489736
Filing Date: 2002-12-03
Classification: H01J

Abstract:
A color cathode ray tube apparatus characterized by comprising an electron gun assembly having a main lens which is made up of at least a focusing electrode and anode electrode, and accelerates and focuses an electron beam on a phosphor screen, and a deflection yoke for generating a deflection magnetic field for deflecting the electron beam emitted by said electron gun assembly,wherein said electron gun assembly has at least one additional electrode located along an equipotential plane of a potential distribution formed between the focusing electrode and anode electrode forming the main lens, in a no-deflection state in which the electron beam is focused on a center of the phosphor screen, the additional electrode receives a voltage of a predetermined level corresponding to a potential of the equipotential plane on which the additional electrode is located, and in a deflection state in which the electron beam is deflected to a periphery of the phosphor screen, letting Vf be an application voltage of the focusing electrode, Eb be an application voltage of the anode electrode, and Vs be an application voltage of the additional electrode, a value (Vsâˆ’Vf)/(Ebâˆ’Vf) changes with an increase in electron beam deflection amount, while the additional electrode forms an electron lens having different horizontal and vertical focusing powers.