MATRIX-TYPE LUMINOUS CATHODIC SCREEN Russian patent published in 2002 - IPC

FIELD: electronic engineering; flat screens with many light-emitting parts; luminescent television screens, and vacuum luminescent displays. SUBSTANCE: screen has evacuated envelope built up of face panel and insulating base with rows of evaporated anode electrodes in the form of parallel bars covered with phosphor of at least one color and connected by means of current-carrying tracks to external terminals through contact pads; set of filamentary cathodes; control electrodes which are orthogonal to anode electrodes and form light-emitting segments; insulating frame interconnecting through sealed joint face panel and insulating base; novelty is introduction of cathode grid curtain with duty factor 0,1±0,06 following condition being satisfied: , where K is grid-curtain duty factor; S_cm is area occupied by cathode-grid curtain metal; S_W is cathode-grid window area; distance between set of cathodes and cathode grid as well as between cathode grid and set of control electrodes meets following inequality: 1/2X_Cg-Cl≤ X_C-Cg< X_Cg-Cl, where X_C-Cg is distance between set of cathodes and cathode grid; X_Cg-Cl is distance between cathode grid and set of control electrodes. In addition cathode grid is placed between set of control electrodes and set of cathodes; cathode grid is placed between face panel and set of cathodes. Novelties introduced provide for enhancing current take-off to anode and brightness of glow, chrome, visible uniformity of brightness in different colors, and for reducing parasitic contrast. EFFECT: enhanced economic efficiency and service life of screen. 3 cl, 2 dwg