| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanner which controls the amplitude with high precision, without being affected by change of the drive frequency of an optical scanner. SOLUTION: The optical scanner having a drive coil and a sensor coil formed on a mobile plate is provide with a current supply means for the drive coil, a detection means which outputs a detection signal, corresponding to an induced electromotive force generated in the sensor coil, and a control circuit 4a which controls electricity supply of the current supply means, on the basis of the detection signal, and the control circuit 4a is provided with oscillation frequency control means 403, 404, 408, and 402 which control the frequency of torsional oscillation of the mobile plate, an integral circuit 409 which gives a gain inversely proportional to the frequency to the detection signal in a frequency band in the vicinity of the torsional oscillation frequency of the mobile plate, and amplitude control means 405, 406, 407 and 408 which control the amplitude of torsional oscillation of the mobile plate, on the basis of the output of the integration circuit 409.
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