Cathode ray tube with plural beams for each color element

Claim 1

A cathode ray tube comprising an electron receiving screen having sets of different color phosphors arranged in a repetitive pattern and each including a central color phosphor and two other color phosphors at opposite sides of said central color phosphor considered in one direction parallel to the plane of said screen; beam selecting means spaced from said screen and having apertures each corresponding to a respective one of said sets of color phosphors; and electron gun means including cathode means emitting electrons, first and second grid means arranged successively in adjacent opposing relation to said cathode means and having aligned apertures for passing electrons from said cathode means in respective electron beams directed toward said screen, each of said first and second grid means having a central group of apertures to define a central beam group for impingement on said central color phosphor of said color phosphor sets and two side groups of apertures spaced symmetrically in said one direction from said central aperture group at opposite sides of the latter to define respective side beam groups for impingement on said other color phosphors at respective sides of said central phosphor of each of said sets, the apertures in each of said central and side groups of apertures being spaced from each other in another direction substantially at right angles to said one direction, electron focusing lens means interposed between said grid means and said beam selecting means for focusing all of said beams of said groups at said screen, said focusing lens means having an optical axis and said aperture of said central group lying on a line that extends through said optical axis, and beam deflecting means located between said focusing lens means and said beam selecting means and including two sections arranged in axial succession, one of said sections deflecting beams of each of said groups in said other direction for converging all of the beams in each group to a respective common landing spot on said screen, and the other of said sections deflecting only said side beam groups in said one direction for converging the side beam groups with said central beam group at a common area of said beam selecting means so that, when said common area corresponds to an aperture of said beam selecting means, said common landing spots of the central and side beam groups will correspond to said central color phosphor and the other color phosphors of the respective color phosphor set.