| 摘要 |
<p>A method of and apparatus for determining authenticity of coins based on difference in surface irregularity pattern of coins. A coin passage is inclined at a predetermined angle, and an exciting coil is arranged near one side wall of the coin passage such that the two magnetic poles of the exciting coil face the coin passage. Two receiving coils having substantially identical characteristics are arranged near the same passage wall such that they are electromagnetically coupled with the exciting coil. The exciting coil is excited at a predetermined frequency, and an influence of a demagnetizing field caused by eddy current induced on the surface of a coin is detected by the receiving coils. The level of the demagnetizing field varies depending on difference in surface irregularity pattern of coins, and thus authenticity of coins can be determined based on the difference in surface irregularity pattern. This can be attained with a simple, inexpensive arrangement. Even those coins which are almost identical in material, outside diameter and thickness can be discriminated from one another based on the difference in surface irregularity pattern. <IMAGE></p> |
