Visual display devices

Claim 1

A visual display device which includes a plurality of discharge cells comprising a block of electrically insulating material containing a plurality of gas-filled cavities arranged in a two co-ordinate array, a first set of electrical conductors located adjacent like ends of the cavities and in contact with the discharge gas therein, each conductor of said first set forming first electrodes of a particular group of cells extending along one coordinate of the array, a plurality of second electrodes each located adjacent the other end of an individual cavity and in contact with the discharge gas therein, a plurality of electrically resistive elements each of which is connected to a different second electrode, a second set of electrical conductors, each conductor of said second set interconnecting the resistive elements of a particular group of cells extending along the other co-ordinate of the array, and a glow transfer device including a plurality of pairs of spaced electrodes in a common gas-filled discharge space, one electrode of each of the pairs comprising a conductor of one of said sets of electrical conductors and the other electrode of each of the pairs extending parallel to said one electrode, and means for sequentially energising said other electrodes of the pairs of electrodes so as to cause a discharge formed between the electrodes of each pair to scan along the glow transfer device by the mechanism of glow transfer and to change the potential of each of said one electrodes of the pairs of electrodes in turn.