Focus control results in multi-focal imaging. (a) Experimental setup. (b) Input electric currents. (c) Photodiode outputs representing the resulting optical powers and the target pattern, respectively (blue: naïve, red: proposed, black: target). Vd100, Vd200, and Vd1500 represent the photodiode output values when the ETL focused at the targets, respectively. (d) Images captured per period in the naïve method (left) and their PSNR values (right), computed by comparing the captured images with those focused at the targets in (a). (e) As for (d), but for the proposed method. The green, purple, and orange plots correspond to the near, middle, and far targets, respectively.