A COIN HANDLING APPARATUS

Abstract: This invention relates to coin selector mechanisms having in a consecutive arrangement three protection zones, two of them being optical and one of them being and electro­ magnetic zone intermediate the two optical zones, the optical zones taking the form of phototransistor type sensors while the electromagnetic zone, which is preferably the central zone, is embodied by at least one and preferably two wind­ ings which are interconnected and positioned opposite one another on either side of the coin path so that the fields produced by the coils intercept the coin path, the coils being connected to an oscilattor having two outputs, one output being connected to a microprocessor and the other output being connected to a rectifier connected to an analog-to-digital converter which outputs to the micro­ processor.

Description: The invention relates to a coin handling mechanism according to the features cited in the preamble of claim 1. Coin-operated machines such as automatic vending machines, amusement-with-prizes machines and so on, each have a coin handling mechanism, which may be adapted to accept coins of various differing values. A typical coin handling mechanism comprises means for determining the value of the coin introduced and means for determining whether or not the coin is genuine. These detection means are usually constituted my mechanical devices which make predetermined checks on the basis of the weight and/or dimensions of acceptable coins. Some prior proposed coin handling devices are inefficient since they cannot detect counterfeit coins made of metals or alloys different from that of the genuine coins if the counterfeit coins have the same weight and dimensions as the genuine coins. US-Patent Specification No. 3 797 628 discloses the coin handling mechanism of the kind with the features cited in the preamble of claim 1. This known mechanism comprises a mechanical start control and behind it a first check zone of two photo-electric sensors spaced apart a predetermined distance along the path for the coin. This first pair of sensors provide informations concerning the velocity of the coin immediately before it enters the magnetic field of magnetic means. Every coin passes through the magnetic field and eddy currents are induced such that a retarding force is created. A second pair of photo-electric sensors are disposed at the path and provide informations concerning velocity of the coin as it emerges from the magnetic field. This mechanism is complex and needs a long path for checking and stopping the coin. The precision of the measurement depends on the alternations of the velocity as well as changes of the temperature and friction influences. European Patent Application 164 110 discloses a coin discrimination apparatus comprising electro-magnetic detecting means for detecting as an electrical signal a physical characteristic of a coin, an analog-to-digital converter for converting an output of the detecting means to a digital signal and furthermore comprising a memory device for receiving as an address signal the digital signal generated from said converter and for storing a finally signal. There are needed two electro-magnetic sensors which must be absolutely identically in there mechanical and electrical properties since the cross point of the electrical signals generated by said sensors should correspond to the diameter of the coin. The invention has the object to improve the coin handling mechanism of the kind mentioned above such that the mechanism is easy to manufacture and that the mechanism can detect coins made from known magnetic materials. This object is achieved by the features cited in the characterising part of claim 1. Preferably the electro magnetic sensor comprises at least one pair of coils disposed on, opposite sides of the coin path, each coil having an electro-magnetic field which intercepts the coin path, there being an oscillator to excite the arrangement and means to determine the electro-magnetic properties of a coin passing through the electro-magnetic fields of the coils. Advantageously each coil is directly connected to one output of an oscillator the oscillator having a further output which is connected to a microprocessor. The microprocessor being adapted to process the signals supplied to it to determine the characteristics of the variations experienced by the oscillator during the passage of a coin through the said electro-magnetic sensor. Preferably the output of the oscillator that is connected to the micro processor is connected to the micro processor through a rectifier and an analogue-to-digital convertor Conveniently a further output of the oscillator is fed to the microprocessor as a clock input. The microprocessor comprises the means to determine the acceleration and preferably additionally the speed of the coin between the photo-electric sensors. Determined values relating to the coin are compared with corresponding values stored in a memory. A coin rejection arrangement may be activated if no valid comparison can be effected, but if a comparison is effected the coin is accepted and a signal is generated to activate the machine associated with the coin handling mechanism. In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawing which is a schematic block diagram of one embodiment of the invention. Referring the drawing a coin handling mechanism in accordance with the invention is adapted to receive a coin 1 and to direct the coin along a predetermined path 2. The predetermined path is not horizontal and is thus inclined downwardly or is vertical, so that the coin passes along the path under the influence of gravity. The coin will, of course, move along the path with a velocity and an acceleration determined by the mass of the coin. Disposed at two spaced positions along the path 2 are photo-electric sensors 3, 4. The sensors 3,4 are spaced a predetermined distance apart defining a check zone. Each sensor 3,4 is constituted by a photo-diode light emitter and a photo-transistor light receiver. The sensors may be adapted specifically to determine the diameter or thickness of the coin. Between these sensors 3 and 4 there is a further sensor 5 which is an electro-magnetic measuring sensor. The electro-magnetic measuring sensor is provided with a pair of coils 6 which are electrically interconnected and which are located on opposite sides of the path 2 followed by the coin 1. The coils are so located that the electro-magnetic field of each coil intercepts the coin path. The coils 6 are directly energised by an oscillator 7. An output of the oscillator 7 is connected to a microprocessor 8 to provide a clock input signal for the microprocessor and a further output of the oscillator 7 is passed through a rectifier 9 and an analogue-to-digital convertor 10 to the micro processor 8. To preclude any possible oscillator drift an automatic compensator 11 is provided connected between the rectifier 9 and a control terminal of the oscillator 7 to minimise a risk of any long term variation of the amplitude or frequency of the oscillator. The optical checking zones 3 and 4 are also connected to the microprocessor 8. The micro processor 8 is associated with a memory 12 and is provided with output terminals 13 and control input terminals 14. In operation of the described device a coin 1 is inserted into the coin handling device and falls, under the influence of gravity, following the path 2. The coin enters and leaves the sensor 3. The moment that the leading edge of the coin intercepts the beam of light between the photo-diode and the photo-transistor is effectively recorded in the micro processor 8, as is the instant that the light beam is re-established as the trailing edge of the coin leaves the sensor 3. As the coin enters the magnetic sensor 5 the coin influences the inductance of the coils 6, thus altering the operating conditions of the oscillator 7. This alteration becomes manifest in the form of a variation in the oscillator amplitude and frequency. This variation in amplitude and frequency is fed, via the rectifier 9 and the analogue-to-digital convertor 10 to the microprocessor 8. The coin then passes through the sensor 4 where again the instant of interception of the light beam between the photo-diode and the photo-transistor is recorded, and again the instant of reestablishment of the light beam is recorded at the micro processor 8. From the information received by the microprocessor it is possible for the microprocessor to determine to speed and/or acceleration of the coin, and to determine its electrical characteristics. If the sensors 3 and 4 measure the diameter and width of the coin, such information can also be fed to the microprocessor 8. The micro processor 8 is programmed to compare data determined from the received signals with corresponding sets of data stored in memory 12, corresponding to the data generated by a valid coin of an acceptable denomination or value. If a comparison is effected, the coin is effectively identified as a valid coin of a predetermined value. If a comparison is not effected, the coin is effectively identified as an invalid coin, either being a coin of a denomination not acceptable to the coin handling apparatus, or being a counterfeit. The microprocessor may, in such a situation, provide an output signal through an output 13 to operate a coin-rejecting mechanism.

Claims: A coin handling mechanism comprising means defining a path (2) to be followed by a coin (1) means defining a check zone of two photo-electric sensors (3, 4) spaced apart a predetermined distance along the said path for determing the speed of the coin and magnetic means near by said path characterised in that the magnetic means are constituted by an electro-magnetic sensor (5) for detecting electro-magnetic properties of the coin (1) that the electro-magnetic sensor (5) is arranged between the both photo-electric sensors (3, 4) and that the signals received from said two photo-electric sensors (3, 4) and the electro-magnetic sensor (5) are fed to a microprocessor (8) for determing the acceleration of the coin (1) as well as for comparing with corresponding sets of data stored in a memory (12) corresponding to genuine coins. A coin handling mechanism according to claim 1 wherein said photo-electric sensors (3, 4) are adapted to measure directly the diameter and/or width of the coin (1). A coin handling mechanism according to claim 1 or 2 wherein the electro magnetic sensor (5) comprises at least one pair of coils (6) disposed on opposite sides of the coin path (2), each coil having an electro-magnetic field which intercepts the coin path, there being an oscillator (7) to excite the coils (6). A coin handling mechanism according to claim 3 wherein each coil (6) is directly connected to one output of the oscillator (7), the oscillator (7) having a further output which is connected to the microprocessor (8), the microprocessor being adapted to process the signals supplied to it to determine the characteristics of the variations experienced by the oscillator (7) during the passage of a coin (1). A coin handling mechanism according to claim 4 wherein the output of the oscillator (7) that is connected to the microprocessor (8) is connected to the microprocessor (8) through a rectifier (9) and an analogue-to-digital converter (10). A coin handling mechanism according to claim 5 wherein a further output of the oscillator (7) is fed to the microprocessor (8) as a clock input. A coin handling mechanism according to any one of claims 5, 6 and 7 wherein the micro processor comprises the means to determine the speed of the coin between the check zones.

Inventors: ECHAPARE IBARROLA, JESUS, Echapare Ibarrola, Jesús 
Applicants: AZKOYEN INDUSTRIAL, S.A.
Application year: 1987
Main classification: G07F3
IPC codes: G07F5, G07D5