A versatile selection system for matrix displays requiring AC drive waveforms

An apparatus which generates complex high-voltage drive waveforms with zero d.c. content for matrix or multiplexed displays is described. It is versatile in that the same apparatus can generate several types of selection waveforms. Most of the component circuits are of the low-voltage binary-level switching type with few high-voltage drive devices and float on the outputs of other circuits. The breakdown voltages of the drivers are minimized by synthesizing the required complex high-voltage waveforms from simpler lower amplitude component waveforms. This scheme is particularly suited to driving liquid crystal displays.