Abstract: It is a recent trend in a fluorescent display device comprising a plurality of anode units, each composed of segmented anodes arranged in a preselected configuration, that grids aligned in one-to-one correspondence to the anode units are rendered narrower in the direction of alignment. The device comprises a first and a second group of anode connections for every other one of the anode units and the remaining anode units, respectively, with each of all anode connections connected to a prescribed one of the segmented anodes of each anode unit. For making the device display at least one digit, a grid driver energizes all grids, preferably cyclically, a particular one at a time slot together with at least one nearest grid. An anode driver selectively energizes the anode connections of one of the two groups that includes the anode unit to which the particular grid is in one-to-one correspondence.

Abstract: A luminescent display panel comprises a substrate assembly comprising a solid insulator substrate and an underlying and an overlying insulator layer successively thereon, a glass cover, and a sealing layer sealing the glass cover and the substrate assembly to enclose a vacuum space where electrodes of the panel are placed. Use is made of a sealing mass for positively eliminating slow leak which otherwise occurs if at least one of the leads for the electrodes interposed between the insulator layers is extended outwardly of the vacuum space continuously along the overlying layer. The sealing mass may comprise that portion of the underlying layer which lies across the sealing layer, with all leads laid directly on the solid substrate at their portions extended across the sealing layer.

Abstract: A method for producing multi-figure luminescent display tubes comprising a step of baking a frit glass for fixing parts such as grid electrodes and filament supports onto a substrate which is provided with segment electrodes having phosphor layers applied thereon. The baking process is carried out in a non-oxidizing environment and an infrared heater is used prior to baking to eliminate the frit binder.

Abstract: A multi-digit luminescence display tube comprises an anode assembly including a plurality of luminescent anode segments for each digit, a cathode, a plurality of grids disposed between the cathode and the anode segments of the respective digits, structure for supplying first voltages to the grids and to at least a selected one of the anode segments to make the same luminesce, and apparatus for superposing a second voltage on the first voltage supplied to at least a selected one of the grids to suppress luminescence at the anode segments covered thereby. The cathode comprises a common filament for the anode segments of all digits. Structure is provided for rendering the second voltage non-negative without adversely affecting the brightness of the selected anode segment which are not covered by the selected grid.