METHOD FOR CONTROLLING A DRIVE DEVICE OF A MICRO-OSCILLATION MIRROR, CONTROL APPARATUS AND DEFLECTION MIRROR DEVICE

摘要

A method for controlling a drive device of a micro-oscillation mirror, a control apparatus and a deflection mirror device are described. In the method, at least one control signal (20) is generated and is used to control the drive device in such a manner that the latter drives the micro-oscillation mirror in an oscillating manner. At least one position signal (26) characterizing the deflection (22) of the micro-oscillation mirror is captured. The at least one control signal (20) is regulated on the basis of the at least one position signal (26) in such a manner that the micro-oscillation mirror is driven at the resonant frequency thereof. The amplitude of the at least one position signal (26) is continuously compared with at least one threshold value. At least one interval of time between at least two passes of the at least one position signal (26) through at least one threshold value is determined. The at least one control signal (20) is regulated on the basis of the at least one interval of time. The control signal (20) is a pulse-width-modulated signal, for example. In this case, unipolar square-wave pulses are generated at periodic intervals. The pulses of the control signal (20) control a comb drive of the drive device, such that the micro-oscillation mirror is excited to oscillate. The comb capacitance of the comb drive, which is converted into an amplitude change, is output as the position signal (26). In order to adapt the duty factor of the control signal (20) to the resonant frequency of the micro-oscillation mirror, the position signal (26) is compared with threshold values. Corresponding intervals of time are determined between particular passes of the position signal (26) through the threshold values. The duty factor of the control signal (20) is accordingly adapted on the basis of the intervals of time.