the invention concerns drive circuitry for generating a plurality of independent drive voltage signals for a plurality of electrodes of at least one liquid lens , the liquid lens comprising first and second miscible liquids , an interface between the first and second liquids being movable by electro wetting by application of a drive voltage signal to at least one electrode of the liquid lens , the drive circuitry including generating circuitry arranged to generate a fixed drive voltage ; a duty cycle controller arranged to receive data values indicating a duty cycle to be applied to each of the plurality of electrodes , and to generate a control timing signal for each of the plurality of electrodes , each control timing signal having the duty cycle indicated by the controller ; and driving means arranged to generate an independent drive voltage signal for each of the plurality of electrodes by selectively applying the fixed drive voltage , based on the control timing signal associated with each liquid lens .