A solid-state matrix-addressed display

Cadmium selenide (CdSe) switches have been devised to control the luminous emittance of electroluminescent cells in a solid-state display. The technique employed makes use of the hysteresis in CdSe to change the resistance of the material to some low value when a switching voltage is applied. In its low-resistance state, the CdSe switch can energize an electroluminescent cell connected in series with it. By wiring the cells in rows and the switches in columns, a display panel results in which each cell-switch combination can be individually addressed by energizing the appropriate row and column. This paper describes the principles of operation and outlines the construction techniques for this display. Performance characteristics of a 100-unit display panel are discussed. This panel, with 20 lines per inch resolution, has been operated with addressing pulses of 25 microseconds duration, providing an output brightness of 20 footlamberts. The construction process is adaptable to mass production, resulting ultimately in low cost. The display has memory thus allowing random access, and operates on very little power. Demonstration of this display represents a significant advancement in the state of the art. This small display possesses the characteristics necessary for development of practical large-area displays.