CATHODE-RAY TUBE

PURPOSE:To generate a spot focus of an electron beam sharply by furnishing a convergence correcting magnet for electron beam at the periphery of the prefocusing electrode part of an electron gun arranged in the neck tube of a cathode-ray tube. CONSTITUTION:A funel 2 is sealedly joined with a panel 1, and thereto a neck tube 3 fitted internally with an electron gun 10 is installed so that an envelope is formed. An electron beam emitted by the electron gun 10 is converged and accelerated by a prefocusing electrode part, and upon correction of eventual static misconvergence by a hexapolar magnet 6, is deflected by a deflection yoke 4 which is arranged at the boundary between the funnel 2 and neck tube 3. In this cathode-ray tube 20, a convergence correcting magnet 9 for electron beam is installed at the periphery of the prefocusing electrode part of the electron gun 10. The magnet 9 should be of hexapolar type and be preferably consolidated with a beam twisting coil 8 which is wound on the neck tube.