Miniaturized cathode-ray tube with precisely oriented electrostatic deflection electrodes

Claim 1

A character display system having a plurality of side-by-side cathode-ray tubes, each displaying separate characters comprising in combination, each said tube having an unflared envelope whose internal dimension perpendicular to the longitudinal axis does not exceed 0.8 inch, and an overall length less than four inches, said tube having substantially symmetrical sidewalls with a closed transparent end member including a phosphorescent coating upon which the cathode ray impinges and two pairs of electrostatic deflection plates to deflect the cathode-ray beam in two dimensions to produce a pattern upon said phosphorescent coating representative of characters such as alphanumeric displays, and further having a glass stem with a set of terminal pins extending therethrough at a predetermined orientation to said deflection plates, means forming separate characters upon the coating of separate tubes by deflecting a single cathode-ray beam striking said coating over pattern identifying a lEgible symbol in each tube, with the plurality of tubes aligned in said side-by-side array to provide an intelligible line of messages text thereupon by producing different deflection potentials at said electrostatic deflection means for each tube of said plurality, a set of electrodes comprising an electron gun in each said tube for forming and directing a discrete beam to said coating all being held in precise position by portions thereof being held by a pair of spaced glass beads extending along the length of the set of electrodes, each deflection electrode of one pair of said two pairs comprising a single flat plate bent at an intermediate position and held by an integral tab extending into said beads, and tab means for attaching the deflection electrodes of the second of said two pairs to said beads for aligning said two pairs for scanning two normal axes within a tolerance of less than three degrees relative to said predetermined orientation, whereby each of said tubes forms a character in said line precisely oriented and positioned to prevent visibly detectable misorientation of characters caused by mispositioning or skew.