Focussing electrode structure for colour TV CRT - has three apertures,with centre one circular and outer two of elongated shape of specified dimensions

摘要

The c.t. has heating elements in parallel coupled to cathodes generating electron emissions passing through control and screen electrodes. These are followed by a focussing electrode unit (1) having three apertures with a common centre line. The central aperture (a) is of circular cross-section, while the outer two (b', c') are of an elongated shape. The elongation is defined by the equation y + 0.04 less than or equal to x which is less than or equal to y + 0.14. Dimensions are in millimetres and x is the length and y is the width. ADVANTAGE - Improved focussing.