| 摘要 |
PURPOSE:To attain recording with high density, by preventing a detecting probe from being brought into contact with a storage medium, reading a bit of information by measuring capacitance between the probe and the storage medium, or a tunnel current generated at time of impressing a voltage between them. CONSTITUTION:A gap (ha) between the tip of the probe 20 and the surface of the storage medium 1 is held in constant invariably at the gap (several ten angstroms) to detect the capacitance in a micro area, or the gap (10 angstroms) to generate the tunnel current. And detected capacitance or tunnel current is fed back, and a piezoelectric element 22 is driven by a control circuit, and the probe 20 is moved in a direction of (z). At such a time, the upper limit of the response frequency of the movement of the probe is set less than the frequency of the change of the capacitance to detect a bit string, or that of the change of the tunnel current. Therefore, it is possible to separate the detecting signal of the bit string in the influence of the fluctuation in the gap (ha), from disturbance. |
