Crossed-grid electroluminescent panel displays with sequential and random access

Abstract

Several electronic systems have been devised to obtain access to crossed-grid or x-y electroluminescent panels. These panels incorporate a continuous layer of glass-imbedded electroluminescent phosphor overlaid by an impedance-matched non-linear resistive layer. This layer is used to suppress the cross-light effect which results from half voltage excitation on the coordinate lines. Arrays with 16 elements to the linear inch have been prepared. Brightness-voltage data are presentd for panels operating in the frequency range of low audio to 300 kc. Magnetron beam switching tubes are employed as the basic switching and modulating elements for both sequential scanning and random access operation. A fast sequential, single pulse system, capable of element excitation in the low microsecond range is described. Where the panel frame time is not critical, an ac burst system is feasible. The random access system is also described. The principle of this system has been demonstrated in a 100- element panel audio-frequency oscilloscope.