| 摘要 |
<p>PURPOSE:To surely identify the thickness of a coin by detecting the thickness of the coin with the change of the static capacity between a pair of electrodes to provide a guard ring electrode and the fluctuation width of the resonance voltage due to this. CONSTITUTION:An electric force line by a resonance output signal by resonance circuits 7 and 8 is impressed by sensor electrodes 2 and 3 to obtain the fluctuation at the time of passing through a coin and a guard ring electrode to prevent the diffusion of the electric force line to occur from the electrode, so a to cross the coin passage. In the condition, when the coin passes, the static capacity between electrodes 2 and 3 is changed, and accompanying this, a resonance output voltage is fluctuated. The fluctuation follows the change of the thickness of the coin. Then, when the fluctuation width of the resonance output voltage signal is within the range of a certain specified reference voltage, it is acknowledged that the coin is within the range of the specified thickness. In this case, since the electric force line is contracted to a beam shape by the guard ring electrode, the thickness of the coin can be finely detected.</p> |
