A liquid crystal array device (10) comprises a liquid crystal material contained between two substrates (12, 20), a first and a second plurality of electrodes (16, 22) defining a plurality of pixels and driving circuitry (18, 26, 28) for applying a first signal (Strobe Voltage) in succession to the first plurality of electrodes and for applying a plurality of second signals (Data Voltage) to each of the second plurality of electrodes. Each second signal comprises one of at least a first waveform (a) and a second waveform (b) and the first waveform and the second waveform each comprise first and second signal levels. The first waveform (a) and the second waveform (b) further comprise at least one portion at a third signal level different from the first and second signal levels. This provides a limited difference in heating effect upon the array between a signal comprising a plurality of first waveforms (a, a, a, a etc.) and an alternating succession of first and second waveforms (a, b, a, b, a, b etc.).