| 摘要 |
<p>A displacement sensor capable of detecting with a simple structure the displacement amount of a moving object with a micron-meter to nano-meter resolution. An exciting coil (23) and a detecting coil (25) are juxtaposed, and a conical magnetic probe (27) having its sectional area changing in a lengthwise direction is disposed while being inserted into the air core of the exciting coil (23). An output terminal from the detecting coil (25) is connected with an amplifier (33), and a phase shift circuit (35) is provided between the amplifier (33) and the input terminal of the exciting coil (23). When the magnetic probe (27) moves in the air core of the exciting coil (23), the inductance of the coil (23) changes to produce a phase difference between an input signal to the coil (23) and an output signal from the detecting coil (25) and allow the phase shift circuit (35) to change a frequency so as to reduce the phase difference to zero, whereby a displacement amount is detected from a frequency deviation.</p> |
