Optical deflector

An optical deflector comprising:

• a mirror part configured to have a reflective plane;
• a support part configured to support the mirror part;
• a piezoelectric actuator of which one end is connected to the mirror part, of which the other end is connected to the support part, and which swings the mirror part about a predetermined axis relative to the support part by piezoelectric driving;
• a detecting piezoelectric element which outputs a detection voltage based on bending deformation due to vibration transmitted by the piezoelectric actuator, and
• a control unit configured to control a drive voltage to be applied to the piezoelectric actuator,
• wherein the control unit includes a natural frequency detecting unit configured to detect a mechanical natural frequency relevant to the swinging of the mirror part about the predetermined axis, a voltage signal generating unit configured to generate a voltage signal of a sawtooth waveform periodically repeating an increase and a decrease of a voltage value with a constant amplitude, and a removal unit configured to remove a predetermined frequency component, and
• wherein a voltage signal obtained by removing the natural frequency detected by the natural frequency detecting unit and a harmonic component of the natural frequency from the voltage signal generated by the voltage signal generating unit within a predetermined frequency range is applied as the drive voltage to the piezoelectric actuator and thereafter a frequency component which is equal to or greater than a predetermined value within the predetermined frequency range, out of the frequency components of the detection voltage output from the detecting piezoelectric element, is removed from the drive voltage.