ELECTRON BEAM ADDRESSED PLASMA DISPLAY PANEL

摘要

1309591 Cathode ray storage and display tubes; gas discharge display panels MONSANTO CO 17 March 1970 [18 March 1969] 12898/70 Heading H1D Storage tube apparatus comprises a panel including a plurality of storage cells 26 filled with ionizable gas, an electrode such as apertured electrode 30, a continuous electrode 28 on or in the panel spaced from the cells and on the opposite side thereof, and electron beam addressing means positioned to direct an electron beam selectively on to the insulator panel such as through the apertures of the apertured electrode to establish charges on the insulator surface for initiating gas discharge. A sustaining potential (e.g. D.C. or A.C. (500 V, 300 KHz)) less than that required to initiate a discharge but sufficient to maintain the discharge once initiated may be maintained across the cells, charges on plate 24 from the electron beam then precipitating gas conduction. Insulators 20, 22, 24 may be glass, 0À006 inch thick and cells 26 formed by drilling or etching, with an intercellular spacing of 0À025 inch (1600 cells/ inch2), and filled with 95% He-5% Nitrogen for example. Electrode 28 may be stannous oxide, electrode 30 of Al film, the latter being at ground or positive potential depending on gun 34 potential. Intensity modulation during scanning is effected by beam-gating grid 46. In 105 to 107 torr vacuum, plate 24 deposited charges dissipate in about 10 seconds due to positive ion bombardment and surface leakage and the decay rate may be controlled by surface treatment, e.g. provision of thin, high resistivity stannous oxide layer. Extinction of a character or all displayed information may be by termination of the A.C. voltage, or pulsing the electron beam during the required half cycle to oppose the surface charge due to A.C. source 50. Applications instanced are alpha-numeric display, storage oscilloscopes, and data display in computer time sharing scientific and educational applications. For non-visual readout, the panel need not be transparent, the above panel being adjacent a photoconductive layer between orthogonal crossed-grid transparent conductors.