Color cathode ray tube with inline electron gun with variable distances of side beam passing holes from the central beam passing axis

Abstract

A color cathode ray tube apparatus comprising an electron gun assembly of inline type including an electron beam generating section designed to emit three electron beams having axes extending in the same horizontal plane and a main electron lens section designed to focus the three electron beams emitted from the electron beam generating section. The main electron lens section has at least three grids G5, GM and G6 arranged in the order mentioned from the cathode side. The distance between the axis of the hole for guiding the center beam, made in the grid most close to the cathode side, and the axis of either hole for guiding a side beam, made in this gird, is shorter than the distance between the common axis of the coaxial holes for guiding the center beam, made in the control, accelerating and focusing electrodes constituting the electron beam generating section, and the common axis of either group coaxial holes for guiding a side beam, made in these control, accelerating and focusing electrodes. Hence, the spot which either side beam forms on the center of the phosphor screen when the three electron beams are focused by convergence magnets has no halos extending in the horizontal direction of the screen. As a result, the resultant image can have high resolution at any part of the phosphor screen.