JPS6448356A - Electron gun structural body for color picture tube - Google Patents

Abstract

PURPOSE:To check the occurrence of an eddy current due to a deflection mag netic field as well as to prevent any asymmetrical misconvergence from occur ring by forming a wavy wall on a shielding magnetic pole cylinder side face. CONSTITUTION:The cylinder side 22 of a shielding magnetic pole 20 is formed with a wavy wall 22P over the whole surface of base 23 in the almost vertical direction by a bottomed cylinder body having the base 23, where three electron beam through holes disposed in line are installed, and the cylinder side 22. Consequently, in order to densely display a color picture tube, even if deflection horizontal frequency of a deflecting yoke is made higher than 15, 75kHz for television and set to 64kHz or more and scanning is made at high speed, the occurrence of an eddy current due to a high frequency deflection magnetic field piercing through the cylinder side 22 of the shielding magnetic pole 20 is checked by the wavy wall 22P, and a delay magnetic field to be produced by the eddy current also does not come to occur. Accordingly, asymmetrical misconvergence of a scanning image plane of a central electron beam and both outer electron beams at both phosphor screen ends is hard to occur, so that even at both faceplate ends, convergence slippage is preventable.