| US 7,975,315 B2 | ||
| Atomic force microscope | ||
| Toshio Ando, Ishikawa (Japan); Takayuki Uchihashi, Ishikawa (Japan); Noriyuki Kodera, Ishikawa (Japan); and Naohisa Takahashi, Ishikawa (Japan) | ||
| Assigned to National University Corporation Kanazawa University, Ishikawa (Japan) | ||
| Appl. No. 12/439,598 PCT Filed Jul. 27, 2007, PCT No. PCT/JP2007/064732 § 371(c)(1), (2), (4) Date May 26, 2009, PCT Pub. No. WO2008/029562, PCT Pub. Date Mar. 13, 2008. |
||
| Claims priority of application No. 2006-238886 (JP), filed on Sep. 04, 2006. | ||
| Prior Publication US 2010/0024082 A1, Jan. 28, 2010 | ||
| Int. Cl. G01Q 20/02 (2010.01); G01Q 60/32 (2010.01); G01Q 60/34 (2010.01) | ||
| U.S. Cl. 850—6 [850/37; 850/38; 310/317; 310/316.01; 331/35; 331/116 M; 331/156; 331/183] | 13 Claims |
| 1. An atomic force microscope that causes a cantilever to self-excitedly oscillate at a resonant frequency and obtains information
on a sample on the basis of a resonant frequency shift caused by an interaction between the cantilever and the sample, comprising:
a displacement sensor for detecting displacement of the cantilever; and
a resonant frequency shift detecting section for detecting the resonant frequency shift caused by the interaction between
the cantilever and the sample on the basis of a detection signal from the displacement sensor, wherein
the resonant frequency shift detecting section including:
a reference signal extracting section for extracting a reference signal from the detection signal from the displacement sensor,
the reference signal having a cycle corresponding to oscillation of the cantilever and being restrained from a phase change
in accordance with the resonant frequency shift in the cantilever;
a phase shift signal extracting section for extracting a phase shift signal from the detection signal from the displacement
sensor, the phase shift signal having a cycle corresponding to oscillation of the cantilever and having a phase shifted in
accordance with the resonant frequency shift in the cantilever; and
a phase detecting section for determining the resonant frequency shift by determining, on the basis of the reference signal
and the phase shift signal extracted by the reference signal extracting section and the phase shift signal extracting section,
a phase difference of the phase shift signal from the reference signal.
|