GB1280972A - Improvements in or relating to signal storage devices - Google Patents

Abstract

1280972 Cathode-ray storage tubes M-O VALVE CO Ltd 13 Jan 1971 [30 Jan 1970] 4617/70 Heading H1D [Also in Division G4] A storage screen for a cathode-ray tube comprises an array of gas discharge cells 10, Fig. 3, formed by the apertures in a glass plate 7 and a metal plate 6 which are sandwiched between glass plates 5 and 8. The cells may contain neon at a pressure of 200 Torr and emit visible light, and a conductor 9 sealed through the plate 8 forms an individual electrode for each cell. In Fig. 3 a circular resistor area 18 is centred on each conductor 9 and an aluminium layer 19 overlap each area 18 and fills the interstices between the resistor areas. In operation the layer 19 is maintained at a negative potential, relative to the earthed electrode 6, that is above the striking voltage but below the running voltage for the cells; a high velocity electron beam is adapted to impinge on selected areas of the screen thereby reducing their potential sufficiently to allow the associated cells to strike. The stored image can be erased by earthing the layer 19. In a modification, Fig. 5 (not shown), a layer of bombardment-inducedconductivity material overlies the areas 18 and 19 of Fig. 3 and is in turn coated with a conductive layer. In another arrangement, Fig. 2 (not shown), the layers 18 and 19 are omitted and the potential at the surface of the plate 8 is stabilized by means of a flooding electron beam. In a further arrangement, Fig. 4 (not shown) an apertured glass plate has its apertures aligned with conductive discs connected to the ends of the conductors 9; the sides of the apertures are resistive and the exposed face of the glass plate has a conductive coating. In a modification of the arrangement the plate is itself resistive, so the resistive coatings are not required.