| 摘要 |
An optical deflector (19) includes a mirror (191); a piezoelectric actuator (196a, 196b) adapted to rock the mirror (191) around an axis of the mirror (191); and a piezoelectric sensor (198a, 198b) adapted to sense vibrations of the piezoelectric actuator (196a, 196b). A control unit (23) includes: a saw-tooth voltage generating block (151) adapted to generate a saw-tooth voltage (V y ); an integral block (161) adapted to calculate an integral voltage (V ys ') of a sum of a sense voltage (V ys ) of the piezoelectric sensor (198a, 198b) and a DC offset characteristic voltage (C); a DC offset characteristic voltage calculating block (162) adapted to calculate the DC offset characteristic voltage (C) in accordance with the integral voltage (V ys '); a subtracter block (152) adapted to generate a deviation (e(t)) between the saw-tooth voltage (V y ) and the integral voltage (V ys ') ; and a controller (153) adapted to generate a drive voltage (V ya ) in accordance with the deviation (e(t)) to apply the drive voltage (V ya ) to the piezoelectric actuator (196a, 196b). |
