High-speed driving of liquid crystal lens with weakly conductive thin films and voltage booster

Liquid crystal (LC) lenses with weakly conductive thin films are known to have driving voltages of several volts, which are much smaller than those of devices without them; however, their response characteristics have not been investigated in much detail. Here, we show that low-voltage LC lenses, with the help of an overdrive pulse, can show response times of several 10 ms, which are comparable with voice coil motors currently used for focus-tuning of mobile cameras. We provide data on the lens power as well as real images captured using a lens module and a camera; we also present a compact circuit design that can boost a 3.5 V(rms) square pulse from a mobile battery to 15 V(rms). The results of this study should accelerate the use of LC lenses in mobile applications.