GB2216323A - Coin discriminator - Google Patents

Abstract

A coin discrimination device, comprises a downwardly inclined coin chute (2) having an end stop (3) at a testing region (21) against which stop a coil will come to rest after travelling down the chute; a coin accept path (7) communicating with said testing region, a coin reject path (20) communicating with said testing region; a coin accept mechanism having means (16) movable from a rest position blocking said accept path to a coin accept position permitting passage of an acceptable coin from said testing region to said accept path and means (15) for imparting lateral movement to at least the lower part of said acceptable coin at the testing region from said chute to said accept path for passage therethrough; a coin reject mechanism having means (8) for imparting lateral movement to an unacceptable coin at said testing region so that it is released from said end stop to pass to said reject path; and test means (10, 21) at said testing region serving to actuate or to stimulate manual actuation of one or other of said coin accept mechanism and said coin reject mechanism in response to the presence of an acceptable or unacceptable coin respectively. <IMAGE>

Description

COIN DISCRIMINATOR The invention relates to the discrimination of coins with application to the provision of coin-operated services.

In particular, though not exclusively, the invention relates to a low cost and low power-consuming method of accepting a variety of coins through a single slot and discriminating between a range of coins to be accepted and a range of coins (including fraudulent blanks) to be rejected.

The particular aim of the invention is low cost coin discrimination while accepting some degradation of resistance to frauding.

The invention therefore has application to low cost coinoperated machines vending goods or services in a preferably supervised or 'benign' environment and in particular to low cost supervised-environment pay-telephones.

Traditionally, coin discriminators have divided into two main classes, viz. mechanical and electronic. Because coins of very different monetary value may be physically similar, coin discriminators tend to be constructed either using large numbers of precision components or requiring extensive calibration or both. Also whereas electronic types of discriminators tend to be good at measuring some properties of a coin, such as metal type, they can be poor at measuring other properties of a coin such as its physical diameter.

The problems of physically similar coins of different value multiply as multi-coin discrimination through a single coin-entry slot is attempted, thereby further increasing the cost of the final coin discriminator.

An obJect of the invention is to solve these problems.

Accordingly, the present invention provides a coin discrimination device, comprising a downwardly inclined coin chute having an end stop at a testing region against which stop a coin will come to rest after travelling down the chute; a coin accept path communicating with said testing region, a coin reject path communicating with said testing region; a coin accept mechanism having means movabie from a rest position blocking said accept path to a coin accept position permitting passage of an acceptable coin from said testing region to said accept path and means for imparting lateral movement to at least the lower part of said acceptable coin at the testing region from said chute to said accept path for passage therethrough; a coin reject mechanism having means for imparting lateral movement to an unacceptable coin at said testing region so that it is released from said end stop to pass to said reject path; and test means at said testing region serving to actuate or stimulate manual actuation of one or other of said coin accept mechanism and said coin reject mechanism in response to the presence of an acceptable or unacceptable coin respectively.

Preferably the test means comprises an array of photo-electric detectors with associated illuminating sources, disposed at said testing region and arranged so that coins of different acceptable diameters when at said testing region affect a characteristic respective group of the array to indicate the presence of a specific acceptable coin.

Preferably the test means comprises means to determine the metallic content of a coin at said testing region.

Preferably the test means comprises means to determine the thickness of a coin at said testing region.

In this manner the cost may be substantially reduced in two ways. Firstly by combining a test of coin diameter and optionally coin thickness, with an electronic test of coin material to use these two different measurement techniques in their most effective way. Secondly by integrating all key mechanical elements, which normally would require calibration, into a single moulding which can be dimensionally controlled thereby obviating the need for mechanical adjustment.

In order to promote a fuller understanding of the above and other aspects of the invention an embodiment will now be described below by way of example with reference to the accompanying drawings in which: FIGURE 1 shows a cross-sectional view of an embodiment of the invention; FIGURE 2 shows a part cross-sectional view on the line I I of Figure 1; and FIGURE 3 is a schematic electronic blocked diagram of a control system associated with the embodiment.

The coin discriminator device embodying the invention shown in Figures 1 and 2 consists of a body 1 in which is formed an inclined coin-rundown chute 2 with an end-stop 3 which is an integral part of the body. Coins such as that indicated at 4 may be inserted in the body via a coin entry slot 5 and are constrained to roll down the chute 2 by a rear surface of the body 1 and a side-cover 6 of the body, part of which is shown in Figure 2, until they stop against the endstop 3.

Adjacent to the end-stop 3 are a coin-accept mechanism indicated generally at 7, a coin-reject mechanism indicated generally at 8, and test means in the form of a series of optical sensors 10 and a sensing coil 11 arranged at a testing region 21.

Each of the optical sensors 10 comprises a Light Emitting Diode (LED) 12 disposed to be on one side of a coin when it is against the stop 3 and an optical detector (normally an opto-transistor) 14 disposed to be in line with the respective LED, on the opposite side of the coin such that the presence of the coin may block the beam of light between them. The optical sensors are arranged in an array such that coins of different diameters block a different group of the light beams associated with their different diameters to give a group of output signals from the detectors 14. In the preferred embodiment, 4 optical sensors are used which may be arranged in an array to accept the existing 10p, 20p and 50p coins (United Kingdom currency) and reject the existing lp, 2p and 5p coins.The width of the coin entry slot 5 is chosen to prevent entry of the 1 coin. Two additional optical sensors 10 may also be incorporated to enable the array to accept the proposed new 10p coin and reject the proposed new 5p coin. The test means may also include means (not shown) for checking the thickness of a coin at the testing region.

The sensing coil 11 is mounted in a recess formed in the body 1 to be as close as possible to a coin when it comes to rest at the end-stop 3. In the preferred embodiment, the purpose of the coil is to ensure that such a coin is metallic so that it may be accepted. More sophisticated and expensive circuitry could be used in other embodiments to assess the type of metal that such a coin is made of to improve resistance to fraud.

The coin-accept mechanism 7 may be either manually actuated via a push button (not shown) or, as in the preferred embodiment, it may be actuated by a solenoid (not shown). The coin-accept mechanism has three main elements: a coin-accept hammer 15, a trap-door 16 and a latching link 17.

In the rest position shown in Figures 1 and 2, the trapdoor 16 which is pivotally mounted on the body 1 about an axis 16a is locked in that position by a pin 17a of the latching link 17 such that coins cannot erroneously travel down a coin accept path 19 to a cash box (not shown). When a coin as indicated at 18 is at rest against the end-stop 3 and is to be accepted the linkage 17 is actuated so as to unlatch the trap-door 16 which then pivots to a coin accept position so as to allow passage of the coin down the path 19. At the same time, the movement of the linkage 17 moves the coinaccept hammer 15 through a slot in the body 1 so as to push the bottom of the coin 18 off the chute 2 so that it then falls down the accept path 19. The passage of the coin down the accept path may be monitored by further optical sensors 10 which are suitably positioned in the body 1. In the preferred embodiment the array of optical sensors 10 is arranged such that each of the acceptable coin types gives a unique signature group of output signals before is passes to the accept path thereby minimising the possibility of fraud.

In the event of shock or other disturbance being applied to the mechanism at the time of coin acceptance, the geometry of the chute 2 and end-stop 3 is such as to allow the coin to fall past the end-stop 3 down a reject path 20 over the trapdoor 16 which is in the rest position and be returned to the user. Optical sensors 10 may also be arranged to detect passage of coins down the reject path 20 thereby minimising the possibility of fraud.

The coin-reject mechanism 8 comprises a simple hammer pivotally mounted on the body 1 about an axis 8a which pushes the leading edge of a coin as indicated at 18 away from the chute 2 so that the coin is no longer constrained by the endstop 3 and can roll forward past the end-stop 3 down the reject path 20, monitored by optical sensors 10.

The electronic circuitry directly associated with the device discussed above may be relatively simple as it is intended that the device be controlled by electronics external to it. In the preferred embodiment, for example, the device is controlled by the microprocessor which controls the coin-operated machine. Since the device is normally a peripheral of a central control unit and shares the resources of that central control unit with other functions of the host machine, the total cost of the system is minimised. However this does not prevent the device being provided with its own control microprocessor where circumstances dictate.

One key aspect of the electronics is that it can be rapidly switched to and from a very low-power consuming state by the control unit thereby facilitating the use of the device in power critical applications.

The electronics as shown in Figure 3, comprise, inter alia, buffers 21 to drive the LEDs 12 and, in some embodiments, buffers 22 to amplify the output of the optotransistors 14. The LED drive buffers may be controlled by external electronics. The outputs of the opto-transistors are fed to an external control unit 20.

The other part of the electronics consists of the metal detector circuit associated with the sense coil 11. The sense coil is connected in an oscillator circuit 23 in such a manner that when metal is present within the magnetic field of the sensing coil 11., the amplitude of oscillation is reduced. The oscillator output is fed to a rectifier circuit 24 which outputs a DC voltage which is a measure of amplitude of oscillation. This DC voltage is compared with a reference voltage by a comparator 25 which then supplies a "metal present" signal to the external electronics 20. If the "metal present" signal is "false" then insufficient metal is present near the sense coil. If the "metal present" signal is "true" then metal is present near the sense coil.

In alternative embodiments the metal detector circuit may measure changes in frequency of oscillation due to the presence of metal near the sense coil, or the decay of pulses of current applied to the sense coil, or any of a variety of other well known metal detecting techniques.

In operation, coins are entered by the user and come to rest at the end-stop of the rundown as described above.

In the preferred embodiment in a power crtical application, the control electronics 20 will be rapidly turning the optical sensors on and off in a low power consumption duty cycle.

The entry of the coin is detected by the obstruction of one or more of the light beams of the array of optical sensors 10. When the control unit 20 detects the presence of an entered coin, it switches on the metal detector circuit and allows a sufficient time for the coin to come to rest against the end-stop 3.

The control unit then checks the group of the optical sensor outputs with pre-ordained reference groups which may form either part of the operation program of the control unit 20 or be values stored in an associated memory.

If the optical sensor pattern matches one of the reference values and the "metal present" signal reads "true", the control unit actuates the coin-accept mechanism 7 , else it either actuates, or prompts the user to actuate by a display or indicator means (not shown), the coin-reject mechanism 8.

As mentioned the control unit 20 may embody a microprocessor to examine the group of signals from the detectors 10 and/or the metal detector coil 11, and to control the accept mechanism 7 and the coin operated machine or the reject mechanism 8 accordingly. In a more simple application the outputs from the buffers 22 together with the output from the comparator 25 may be connected to a tree of coded electronic gates to decode the group of signals and operate the coin accept, the coin reject, and the coin operated machine accordingly on detection of an acceptable coin.

Claims (14)

CLAIMS:

1. A coin discrimination device, comprising a downwardly inclined coin chute having an end stop at a testing region against which stop a coin will come to rest after travelling down the chute; a coin accept path communicating with said testing region, a coin reject path communicating with said testing region; a coin accept mechanism having means movable from a rest position blocking said accept path to a coin accept position permitting passage of an acceptable coin from said testing region to said accept path and means for imparting lateral movement to at least the lower part of said acceptable coin at the testing region from said chute to said accept path for passage therethrough; a coin reject mechanism having means for imparting lateral movement to an unacceptable coin at said testing region so that it is released from said end stop to pass to said reject path; and electronic test means at said testing region serving to actuate or to stimulate manual actuation of one or other of said coin accept mechanism and said coin reject mechanism in response to the presence of an acceptable or unacceptable coin respectively.

2. A coin discrimination device as claimed in claim 1, wherein said test means comprises an array of photo-electric detectors with associated illuminating sources, disposed at said testing region and arranged so that coins of different acceptable diameters when at said testing region affect a characteristic respective group of the array to indicate the presence of a specific acceptable coin.

3. A coin discrimination device as claimed in claim 1 or 2, wherein said test means comprises means to determine the metallic content of a coin at said testing region,

4. A coin discrimination device as claimed in any of claims 1, 2 or 3, wherein said test means comprises means to determine the thickness of a coin at said testing region.

5. A coin discrimination device as claimed in any preceeding claim, wherein said coin acceptance mechanism comprises a trap door pivotally mounted to lie across the coin acceptance path when in said rest position and clear of the acceptance path when in said accept position.

6. A coin discrimination device as claimed in claim 5, wherein said coin acceptance mechanism includes a latch link arranged to retain or release the trap door in dependence on detection of an unacceptable or acceptable coin.

7. A coin discrimination device as claimed in claim 6, wherein said latch link includes a hammer portion arranged to push said lower part of an acceptable coin at the testing station from said chute to said coin acceptance path.

8. A coin discrimination device as claimed in any preceding claim, wherein said coin reject mechanism comprises a reject hammer pivotally mounted to move from a rest position clear of the testing station to a reject position at which it pushes an unacceptable coin from said chute to pass the end stop to the reject path.

9. A coin discrimination device as claimed in any preceding claim, wherein said coin accept mechanism and/or said coin reject mechanism is operated by means of a solenoid.

10. A coin discrimination device as claimed in any one of Claims 1 to 8, wherein said coin accept mechanism is manually operable in response to a stimulation from said test means.

11. A coin discrimination device as claimed in any preceding claim, including electronic control means arranged to assess the output from said electronic test means and operate the accept and reject mechanisms and any apparatus controlled by the device accordingly.

12. A coin discrimination device as claimed in claim 11, in which said control means includes a microprocessor.

13. A coin discrimination device as claimed in claim 11, in which said control means includes a coded tree of electronic gates to determine detection of an acceptable coin.

14. A coin discrimination device substantially as herein described with reference to the accompanying drawings.