Patent ID: 11402952

Abstract:
A method and circuit for obtaining a capacitive feedback signal of a capacitive feedback micro torsion mirror are provided to solve the problem of poor stability of the capacitive feedback signals of the micro torsion mirror. First, a pulse signal is used as a driving signal to drive the capacitive feedback micro torsion mirror to vibrate; it is ensured that the micro torsion mirror may twist freely for at least 0.5 cycles during an interval of two adjacent sets of driving pulses; secondly, the capacitive feedback signal of the capacitive feedback micro torsion mirror is extracted, and converted into a voltage signal; then, the voltage signal is amplified; and finally extracted during the interval of the two adjacent sets of driving pulses, and taken as a real capacitive feedback signal. A carrier generation circuit and a detection circuit are omitted, and the influence of the carrier generation circuit and the detection circuit on a capacitive feedback signal is eliminated. The circuit is more concise and the stability of the capacitive feedback signal is improved. Further, a specific driving form and signal extraction manner are used to obtain the real capacitive feedback signal.