CANTILEVER CONTROL DEVICE

Japanese Patent JP3817589

B2

PROBLEM TO BE SOLVED: To provide a cantilever control device preventing the stop of the self-oscillation of a cantilever and the contact of the probe of the cantilever with a measuring target in an atomic force microscope. SOLUTION: In the atomic force microscope, the cantilever control device 1 is constituted of: the cantilever 10 having the probe 12; an actuator 20 for causing the self-oscillation of the cantilever 10; an oscillation speed detector 30 for detecting the oscillation speed of the cantilever 10; a displacement calculator 32 for calculating the oscillation displacement of the cantilever 10 and a controller 40 for forming a signal for driving the actuator 20. A feedback control signal S is set at (K-G×x2)×dx/dt (wherein x is the oscillation displacement of the cantilever 10, dx/dt is the oscillation speed of the cantilever 10, and both of K and G are a feedback gain of a positive value).