Patent ID: 8387159
Filing Date: 2013-02-26
Classification: B82Y,G01Q

Abstract:
1. A scanning probe microscope comprising: a probe device; an excitation unit which excites the probe device; a sensor which detects a displacement signal from the probe device; a feedback circuit which performs feedback control so as to keep interaction between the probe device and a sample constant; and an excitation and detection circuit which generates an excitation signal controlling excitation carried out by the excitation unit and which detects, for feedback control, an interaction amount indicative of the interaction based on the displacement signal, the excitation and detection circuit comprising: an oscillation circuit which generates an excitation phase signal indicative of a phase of the excitation signal; an excitation signal generation circuit which generates the excitation signal based on the excitation phase signal; a complex signal generation circuit which generates a complex signal based on the displacement signal; a vector calculation circuit which calculates an argument of the complex signal by vector calculation; and a subtracting phase comparator which compares the argument with the phase of the excitation phase signal by subtraction, wherein a signal for the interaction amount obtained using the subtracting phase comparator is supplied to the feedback circuit.