| 摘要 |
Provided is an atomic force microscope capable of increasing the phase detection speed of a cantilever vibration. The cantilever (5) is excited and the cantilever (5) and a sample are relatively scanned. Displacement of the cantilever (5) is detected by a sensor. An oscillator (27) generates an excitation signal of the cantilever (5) and generates a reference wave signal having a frequency based on the excitation signal and a fixed phase. According to vibration of the cantilever (5), a trigger pulse generation circuit (41) generates a trigger pulse signal having a pulse position changing in accordance with the vibration of the cantilever (5). According to the reference wave signal and the trigger pulse signal, a phase signal generation circuit (43) generates a signal corresponding to the level of the reference wave signal at the pulse position as a phase signal of vibration of the cantilever (5). As the reference wave signal, a saw tooth wave is used. A phase signal generation circuit (43) is formed by a sample hold circuit.
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