A coin handling mechanism for vending machines has a coin validation sensor (12), a coin accepting gate (20), a plurality of coin distributing gates (21, 22, 23) and a cutter (31a) for cutting a string (70) which is suspending a deposited coin (85). When a coin (85) suspended by a string (70) is deposited in a coin inlet (10) of the mechanism, the string (70) is caught by the coin accepting gate (20) before the coin (85) reaches the coin distributing gates (21, 22, 23). When the string (70) is then pulled towards the coin inlet (10) in an attempt to remove the coin (85), the string (70) is cut by the cutter (31a). The coin (85) with the cut string portion attached thereto then falls down in the machine. In this situation the coin distributing gates (21, 22, 23) are automatically oriented to form a coin path communicating with a cash box (73) therebelow. The coin (85) with the cut string thus falls to the cash box (73), thereby preventing it from being paid or given to a customer.

A coin selector has a coin passageway where coins are inserted. A magnetic sensor inspects the coins through the coin passageway, and generates an inspecting signal, which a controller evaluates to generate an acceptant or unacceptant signal responsively. A gate plate responds to the acceptant or unacceptant signal, and provides two chutes selectively with the inspected coins. An accepting chute passes acceptable coins. A returning chute returns unacceptable coins. A photo sensor detects the acceptable coins through the accepting chute, and generates a detecting signal. Counters are adapted to counting, respectively, the acceptant signal in increment and the detecting signal in decrement. The controller adds together two counts of the counters, evaluates a sum of the addition, and generates an error signal in accordance with the sum evaluation. The error signal is utilized for implication of possible deceit or imposture of a player who inserts the coins.

A system comprising coin-released apparatus (2) incorporates a coin validator (1) which monitors the acceptance ratio between the number of coins accepted for operation of the apparatus and the total number of coins (or purported coins) inserted into the apparatus. A central control unit (7) for the apparatus has a display (8) for the percentage acceptance rate and an alarm system (12) at a remote security unit (11) is arranged to be activated when the percentage acceptance rate falls below a predetermined lower limit, possibly indicating that users are attempting to feed false coins into the apparatus (2).

A coin acceptor includes main body having coin dispenser mounted therein, coin tubes mounted in the main body and disposed at the bottom side of the coin dispenser, and sensing device including multiple optical sensor modules respectively aimed at the coin tubes. The distance between each optical sensor module and the coins in the respective coin tube is calculated by: measuring the time taken for the reflected light to travel from the coins in the respective coin tube to the proximity sensor of the respective optical sensor module and then multiplying the time thus measured by the speed of light. The number of coins in each coin tube is calculated by: deducting the distance between the respective optical sensor module and the coins in the respective coin tube from the pre-measured depth of the empty coin tube, and then dividing the reminder thus obtained by the thickness of single coin.