A liquid crystal based optical deflector includes a light source array configured to generate a laser beam, an optical deflector including a plurality of liquid crystal cells, which transmit the laser beam, the optical deflector configured to deflect a transmission path of the laser beam depending on a gradually increased voltage profile applied to the plurality of liquid crystal cells, an optics assembly configured to scan the laser beam deflected by the optical defector in a horizontal direction, and a controller configured to adjust the voltage profile applied to the plurality of liquid crystal cells.