GB1310643A - Electron tubes for character display - Google Patents

Abstract

1310643 Character display tubes SONY CORP 19 April 1971 [19 Feb 1970] 22019/71 Heading H1D An electron tube for character display comprises a substrate, a plurality of indicating units A 1 , A 2 formed thereon, each unit having a plurality of first segmented electrodes E 1 to E 8 arranged in substantially identical patterns, a plurality of second electrodes P 1 , P 2 , P 3 formed on the substrate, at least one barrier electrode C between each pair of adjacent indicating units and a transparent envelope enclosing all the electrodes. The tube may be of the glow discharge type or the segmented electrodes may be coated with luminescent material and irradiated by electrons from a cathode H. Corresponding segmented electrodes of the indicating units may be interconnected within the envelope and the indicating units may be operated sequentially in a time divisional manner. Instead of one barrier electrode which surrounds all the indicating units a separate electrode may be provided between each adjacent pair of units in which case a further second electrode may be provided surrounding each set of segmented electrodes, Figs. 3 and 7 (not shown). In the case of a glow discharge device the barrier electrodes are kept at a potential such that interference between adjacent indicating units does not arise and that the barrier electrodes themselves do not give rise to a discharge. In the luminescent type tubes the barrier electrodes are held at substantially the same positive potential as those segmented electrodes which are to be displayed. In a preferred construction the segmented electrodes and the second electrodes are printed on the substrate together with their interconnecting conductors 3, 4, a layer of dielectric, e.g. glass frit, is deposited thereon and the barrier electrodes then provided on the insulating layer.