| 摘要 |
<p>In coin discrimination apparatus, a coin under test rolls past first and second inductive sensors (C1, C2) which produce first and second coin signals (x1 x2) in dependence upon the coin under test. The coin signals are compared with data defining first and second stored windows (W1, W2) to determine acceptability of the coin. In accordance with the invention the data for the first and second windows (W1, W2) are stored respectively for providing both a first and a second window width ((W11, W12; W21, W22), wherein the first window width corresponds to the width of a distribution of coin signals associated with acceptable coins of a particular denomination, and the second window width corresponds to the width of said distribution but excludes therefrrom a range of values corresponding to fraudulent coins, and a coin under test is deemed to be acceptable upon the coin signals falling either within a first or a second acceptance condition wherein, for the first acceptance condition, the value of the first coin signal falls within the first window width of the first window (W11), and the value of the second coin signal falls within the second window width of the second window (W22), and for the second acceptance condition the value of the first coin signal falls within the second window width of the first window (W12), and the value of the second coin signal falls within the first window width of the second window (W21).</p> |
