A driver for driving an optical deflector includes a mirror, a movable frame for supporting the mirror, a support body surrounding the movable frame, and a first group of piezoelectric actuators and a second group of piezoelectric actuators alternating with the first group of piezoelectric actuators. A first drive voltage for the first group of piezoelectric actuators has first repeated waves each with a first rising period. A second drive voltage for the second group of piezoelectric actuators has second repeated waves each with a second falling period corresponding to the first rising period of the first drive voltage and a second rising period corresponding to the first falling period of the first drive voltage. Frequencies of the first and second repeated waves exclude natural frequencies of a mechanically-vibrating system of the mirror with respect to the axis thereof depending upon the piezoelectric actuators.