Display system with rapid color switching

Claim 1

A cathode-ray tube comprising in combination: an envelope, said envelope having a neck portion, an accelerating portion, said screen portion comprising beam penetration phosphor layers and a screen portion; an electron gun for producing a beam of electrons, said electron gun being located in said neck portion and said beam of electrons being directed toward said screen portion; a phosphor screen layer, said phosphor screen layer being disposed upon said screen portion of said envelope, the color of light emitted from said screen being dependent upon the velocity of electrons striking said screen layer; a conductive layer, said conductive layer being contiguous to said phosphor screen layer; a first accelerating electrode, said first accelerating electrode being disposed upon a first section of said accelerating portion of said envelope adjacent said neck portion and outside the region traversed by said beam; and a second accelerating electrode, said second accelerating electrode being disposed upon a second section of said accelerating portion of said envelope adjacent said screen portion and coupled to said conductive layer, there being a gap between said first and second accelerating electrodes upon said accelerating portion of said envelope, the color of light emitted from said phosphor screen layer being determined by a voltage applied to said second accelerating electrode, the width of said gap being less than the distance from said electron beam at the nearest approach of said electron beam to said gap and being sufficiently great that substantially no pattern distortion is effected upon changing the magnitude of a voltage applied to said second accelerating electrode.