EP3279875B1 - Pollution detector, coin sorting machine and method for contamination detection for coins - Google Patents

Description

The invention relates to a contamination detector for a coin sorting machine, in particular for determining the fitness for circulation of coins, the contamination detector having at least one control device and two contamination detection devices, each with at least one photosensor, the two contamination detection devices each further having at least two light sources of different colors, the contamination detector having at least a coin transport path for transporting coins and two contamination detection devices, and wherein the contamination detection devices are arranged on the coin transport path and spaced perpendicularly thereto, with a first contamination detection device at the level of a ring/core transition area of a 1 euro coin and a second contamination detection device in Height of the diameter of a 2 cent coin are arranged above a baseline of the coin transport route. The invention also relates to a method for detecting contamination of coins, in particular for detecting the fitness for circulation of coins, using a contamination detector with at least one contamination detection device, which comprises at least two light sources and at least one photosensor for detecting the light of the light sources reflected on a coin. Finally, the invention relates to a coin sorting machine.

Contamination detectors of the aforementioned type and methods for detecting contamination of coins are known. These are usually used to check coins for their fitness for circulation. For this purpose, optical means can be used to check whether a coin is too dirty to be put back into circulation or whether it needs to be sorted out, cleaned or replaced. Corresponding devices and methods are generally used in coin sorting machines, which additionally check a large number of coins for coin value and/or authenticity. From the US 5,923,413 A a recognition device for banknotes is known, which can assess the fitness of the banknotes and in particular also recognize dirty banknotes. Each banknote is illuminated one after the other with light of different colors and the reflected light is received by sensors. The results of the measurement are then compared with reference values. From the US 6,328,150 B1 a device for determining the fitness for circulation of coins is known. Light sources are installed along a transport route for coins. The light reflected on the coins is recorded and evaluated using a CCD.

When detecting contamination, it can be important that it works reliably even when a high coin throughput is required. A quick check should therefore reliably identify whether a coin is still fit for circulation or not.

It is therefore the object of the invention to provide a device according to claim 1 and a method according to claim 10 of the type mentioned above, which improve the recognition accuracy for different coin surfaces and also function reliably at high throughput rates and the associated short verification times.

For the contamination detector according to the invention, the task is solved in that the two contamination detection devices are arranged on a common circuit board.

For the method according to the invention, the object is achieved in that a coin is illuminated with at least two different colors of visible light by the at least two light sources, the light reflected by the coin is detected by the at least one photosensor, and the measured intensity of the reflected light by a control device is compared with at least one comparison value previously stored in a storage unit, using a contamination detector according to the invention.

For the coin sorting machine according to the invention, the object is achieved in that it has at least one contamination detector according to the invention and / or that it is designed to carry out the method according to the invention.

The device according to the invention, the coin sorting machine according to the invention and the method according to the invention therefore use at least two different colors of visible light to detect contamination. This has several advantages. On the one hand, contamination can be easily recognized using visible light, or in particular the type of contamination that is also perceived as such by a human eye can be clearly recognized. The use of at least two different colors can also improve the quality of contamination detection. For example, contamination that is not detected when measuring with only one color can be detected when measuring with at least one other color. In addition to checking the fitness for circulation, the coin sorting machine according to the invention can also be designed to check other features such as coin value or authenticity.

Arranged on the coin transport route means in connection with the contamination detection device that a coin located on the coin transport route is from Light from the at least two light sources illuminates and the light reflected from the coin can be received by the at least one photosensor. The at least one coin transport route can be a rail, for example. Alternatively or additionally, it can also be formed by a movable conveyor such as a turntable, a treadmill or similar. If the at least one coin transport route is part of the contamination detector, it can be ensured that the at least one contamination detection device is optimally positioned in relation to the coin transport route.

By arranging two contamination detection devices on the coin transport route, it can be ensured that coins of different sizes can be checked and also that both contamination detection devices can check a single coin simultaneously or one after the other.

The arrangement of the contamination detection devices in relation to the baseline is helpful in order to be able to carry out contamination detection on euro coins. The baseline is the line from which the height of the coins is measured. In the case of a rail or transport route, the coin lies on the base line. If, on the other hand, the coins are transported horizontally over a turntable or other device, the base line is the line at which the coin passes the contamination detector with a radial end.

The device according to the invention and the method according to the invention can be further improved by various, individually advantageous configurations that can be combined with one another in any way. The designs and the advantages associated with them are discussed below. The embodiments of the device according to the invention can of course be used for the method according to the invention and vice versa.

According to a first advantageous embodiment of the contamination detector according to the invention, the control device can have at least one storage unit or can be connected to one. Previously stored comparison values can be stored in the storage unit. After a measurement, a value measured by the photosensor can be compared with a corresponding comparison value by the control device. The control device can then decide whether the coin is fit for circulation or not based on the comparison of the two values. Preferably, the value measured by the photosensor is compared with two corresponding comparison values, whereby the measured value must lie between the two comparison values so that the coin is classified as fit for circulation.

Furthermore, the control device can have at least one signal output via which a signal which provides information about the fitness for circulation can be output. Such a signal is usually referred to as a fit signal for a fit coin and an unfit signal for a non-fit coin.

Each light source preferably produces exactly one color. For technical reasons, each of the colors cannot be monochromatic, but rather have a corresponding spectrum within the scope of technical possibilities. The spectral maxima of the respective colors are preferably at least 50 nm apart. Furthermore, the spectral maxima should be so far apart that they are still separated from each other at half the maximum height. The half-width of the spectra of the individual colors is preferably less than 40 nm. The light sources are preferably formed by light-emitting diodes (LED). Light-emitting diodes have the advantage that they are cost-effective, space-saving and long-lasting. They also have low energy consumption.

The light sources can be controlled with a color-specific intensity in order to compensate for differences in the sensitivity of the at least one photosensor for different colors.

According to a particularly advantageous embodiment, the at least one contamination detection device can have exactly three light sources which are designed to generate visible light in the colors red, green and blue. This can be advantageous as it makes the basic colors available. Furthermore, all three colors can be used at the same time, so that contamination is detected with white light. Alternatively or additionally, any variations of the three basic colors can be used, provided this is useful for detecting contamination. The different colors can be used one after the other or, as already described, simultaneously. The three colors red, green and blue can be obtained particularly easily by using an RGB LED.

In order to obtain a particularly cost-effective but at the same time reliable photosensor, it can be formed by a phototransistor.

When measuring with different colors, the light sources can each have different intensities in order to compensate for differences in the sensitivity of the photo sensor for different colors.

In order to be able to cover a large area of a coin and also to be able to check different coin sizes, the contamination detector can be two apart have spaced contamination detection devices. Where appropriate, the contamination detector can also have more than two contamination detection devices. The at least two contamination detection devices can be integrated in one component. For example, the two devices can be arranged on a common circuit board. In order to further increase system integration, at least one further coin sensor can also be arranged on a circuit board with at least two contamination detection devices. For example, a remanence sensor for detecting the residual magnetization of a coin can be arranged between two contamination detection devices on a common circuit board.

In the case of at least two contamination detection devices, at least one optical barrier can be arranged between two contamination detection devices in order to prevent the measurements from influencing each other. The optical barrier is preferably made of an opaque material.

Ideally, the two contamination detection devices are located equidistant from the coin transport route or from a coin located on the coin transport route or through a coin transport channel, which is determined by the space through which a coin is moved along the coin transport route. The two contamination detection devices do not necessarily have to be arranged one above the other along a vertical line or a perpendicular to the coin transport route; they can also be offset from one another along a coin transport direction. If the contamination detector also has a remanence sensor described above, this can be arranged between the two contamination detection devices.

The ring/core transition area on a 1 euro coin is usually arranged at a height of 3 mm. The first contamination detection device is therefore preferably arranged so that it covers at least an area between 1 and 5 mm above the baseline. The diameter of a 2 cent coin is usually 18.75 mm. The second contamination detection device is therefore preferably arranged so that it covers at least the range between 16.75 and 20.75 mm.

In order to trigger a measurement process, ie the contamination detection automatically when a coin passes the contamination detector, the contamination detector can have at least one trigger sensor or trigger sensor, which is connected to the at least one contamination detection device and is designed to trigger a measurement process in the at least one contamination detection device. The At least one trigger sensor can detect the passage of a coin optically, magnetically, mechanically or in another suitable manner.

The contamination detector can also have a connection to at least one further coin sensor, which is also connected to the at least one trigger sensor. The at least one further coin sensor can be, for example, a contact image sensor (Contact Image Sensor, CIS), which is designed to recognize the coin type. Likewise, the at least one further sensor can be an eddy current sensor. The at least one contamination detection device can then use the at least one trigger sensor together with the at least one further coin sensor. This allows a high level of system integration to be achieved. The connection can be formed by a suitable interface or a line.

In particular, in the event that the at least one further sensor and the at least one contamination detection device are located at different positions along the coin transport route, a delay element can be present between the at least one triggering sensor and the at least one contamination detection device to delay the triggering of the measuring process. The delay element can also be used to compensate for different reaction times of the sensors or the device.

The contamination detector according to the invention can be designed to allow a coin throughput of 1 to 5000 coins per minute, preferably 3000 to 5000 coins per minute. This can be achieved, for example, by ensuring that the measurement times of the contamination detection devices are correspondingly short. The coins are preferably illuminated for 100 to 300 µs per color by the at least one contamination detection device. However, other measurement durations are also possible. In order to reduce reflection scatter and to avoid incorrect evaluations, several measurements per color, preferably three, can also be carried out and an average value can then be formed.

If the contamination detector has at least two contamination detection devices, both contamination detection devices can simultaneously carry out contamination detection with the same color. This can significantly reduce detection times.

Comparison values are preferably stored for each color in a memory unit, which can be part of the control device or connected to it. Separate comparison values can also be available for color combinations, especially for the color white, which is made up of all three primary colors. The comparison values can, for example, be a measure of the light intensity received by the photo sensor. For example, they can be proportional to the photo voltage or a photo current generated by the photo sensor. To determine the fitness for circulation or the degree of contamination, a measured value from the photo sensor can be compared with a comparison value.

The comparison values can be chosen so that they can be assigned to a coin that is just fit for circulation, i.e. if a value supplied by the photo sensor is below that of a comparison value, the coin is not fit for circulation or the control device can generate an unfit signal. However, if the value generated by the photo sensor is above the comparison value or corresponds to the comparison value, the coin can be classified as fit for circulation.

Each measured value is preferably compared with two comparison values, whereby the measured value must lie between the two comparison values so that the coin is classified as fit for circulation.

A coin is preferably only classified as fit for circulation if the measurement for all colors used and for all contamination detection devices used provides values which at least correspond to the respective comparison values.

It is advantageous if at least one further coin sensor is present, which is designed to recognize the coin type. This can then transmit the recognized coin type to the control device, so that it uses the comparison values stored for this coin type based on the coin type for comparison with the measured values generated by the at least one photo sensor.

The invention is explained in more detail below using two advantageous embodiments with reference to the drawings. The combination of features shown as examples in the embodiments can be supplemented by further features for a specific application in accordance with the above statements. Also in accordance with the above statements, individual features can be omitted from the described embodiment if the effect of this feature is not important in a specific application.

In the drawings, the same reference numbers are always used for elements with the same function and/or the same structure.

Fig. 1

eine erste Ausführungsform eines erfindungsgemäßen Verschmutzungsdetektors in einer perspektivischen Darstellung;

Fig. 2

eine zweite Ausführungsform eines erfindungsgemäßen Verschmutzungsdetektors.

Show it:

Fig. 1

a first embodiment of a contamination detector according to the invention in a perspective view;

Fig. 2

a second embodiment of a contamination detector according to the invention.

Fig. 1 shows a first advantageous embodiment of a contamination detector 1 according to the invention. The embodiment has two contamination detection devices 3. The two contamination detection devices 3 are arranged on a mounting plate 5, which is preferably formed by a circuit board. They are spaced apart at a distance 7.

Each of the contamination detection devices 3 has an RGB light-emitting diode (RGB-LED) 9 and a photosensor 17, which is preferably formed by a phototransistor 19. Each of the RGB LEDs has three light sources 11, 13 and 15 for the three primary colors red, green and blue. The contamination detection devices 3 do not necessarily have to have RGB LEDs 9. They can also have at least two individual light sources 11, 13 or 15, with three light sources preferably being present. In Fig. 1 the individual light sources 11, 13 and 15 are not shown.

The contamination detector 1 has a connecting element 21, which is indicated only by way of example as a plug connector 23 on a back side 25 of the mounting plate 5. A connection to a control device 27 (indicated by dashed lines) can be established via the connecting element 21. Alternatively, it is also possible for the control device 27 to be mounted on the mounting plate 5.

A remanence sensor 29 is arranged between the two contamination detection devices 3 and is equipped with an AMR sensor 31 for measuring an anisotropic magnetoresistive effect of coins. By arranging the remanence sensor 29 between the two contamination detection devices 3, a space-saving combination sensor can be formed. The remanence sensor 29 can be used to check the authenticity of coins and/or to detect the coin type.

In order to prevent the contamination detection devices 3 from influencing each other, at least one optical barrier (not shown) can be arranged between the contamination detection devices 3. The optical barrier is preferably made of an opaque material.

Fig. 2 shows a second advantageous embodiment of a contamination detector 1 according to the invention. The contamination detector 1 has all the features of the first with reference Fig. 1 described embodiment. Only further features have been added. The contamination detector 1 and the other features can be part of a coin sorting machine 32 according to the invention (indicated by a dashed line). For the sake of brevity, the additional features will be discussed below.

The mounting plate 5 with the two contamination detection devices 3 and the remanence sensor 29 is housed in a housing 33. The contamination detector 1 has a coin transport route 35. The coin transport route 35 has a rail 37 over which coins (not shown) can be moved. In the simplest case, coins can be moved over the rail 37 by a conveyor device (not shown). Alternatively or in addition to the coin transport route 35 shown, the contamination detector 1 can also be equipped with an active coin transport device. It is also possible for the contamination detector 1 to be arranged above or below a coin transport route over which coins are transported lying down.

Coins can be transported along a coin transport direction 38 via the coin transport route 35. In the illustrated embodiment, the coin transport path 35 is formed by a rail 37, so that the coins can be moved passively along the rail 37.

Further coin sensors are accommodated in the housing 33, which can belong to a coin sorting machine in which the contamination detector 1 is used. A contact image sensor (CIS sensor) 39 can be used to optically detect the coin type. The contact image sensor 39 is connected to a trigger sensor 41. A coin passing the trigger sensor 41 can trigger a measurement on the contact image sensor 39.

Furthermore, an eddy current sensor 43 may be present. The eddy current sensor 43 can also be connected to a trigger sensor 45, which can be used to trigger an eddy current measurement.

At least one of the trigger sensors 41 or 45 can be connected to the contamination detector 1. For example, a connection can be made via the control device 27 (not shown). Alternatively, a connection can also be established directly with the contamination detection devices 3.

A delay element 47 (not shown) can be arranged between a trigger sensor 41 or 45 connected to the contamination detector 1 and the contamination detector 1, which serves to only start the contamination detection when a coin has arrived in the area of the contamination detection devices 3.

The two contamination detection devices 3 are arranged on the coin transport route 35. They are spaced perpendicular to the coin transport direction 38. A first contamination detection device 3a is arranged at the level of the ring/core transition area of a 1 euro coin and a second contamination detection device 3b is arranged at the height of the diameter of a 2 cent coin above the base line 49 of the coin transport route 35. In the case of the coin transport route 35 described, the base line 49 runs on the rail 37. The contamination detection devices 3 are arranged in such a way that the areas just described can be detected by them.

The method according to the invention for detecting contamination is described below as an example. A coin (not shown) moves along the coin transport direction 38 along the coin transport route 35.

When the trigger sensor 41 passes, a measurement is triggered using the contact image sensor 39. The contact image sensor 39 detects the coin type or the coin value of the coin. The recognized coin type can be communicated to the contamination detector 1. At the same time, a trigger signal from the trigger sensor 41 can also be transmitted to the contamination detector 1 or to the contamination detection devices 3 via a delay element 47 (not shown).

The coin can continue to move along the coin transport path 35 and pass the eddy current sensor 43, with the eddy current measurement being triggered by the trigger sensor 45.

As soon as the coin has arrived in the area of the contamination detector 1 or in the area of the contamination detection devices 3, a contamination detection measurement can be started. As already described previously, the measurement can be started by the trigger sensor 41 or alternatively by the trigger sensor 45, with a delay element 47 can serve to only start the measurement when the coin has arrived in the area of the contamination detection devices 3.

To detect contamination, the coin is illuminated with at least two colors of visible light. The color with the three primary colors red, green and blue is preferably illuminated by the three light sources 11, 13 and 15. If the contamination detector 1, as shown in the embodiment, has two contamination detection devices 3, both contamination detection devices 3 can either be active at the same time, i.e. each illuminate the coin with the same light. Alternatively, the contamination detection devices 3 can carry out the contamination detection one after the other.

Preferably, the coin is first illuminated one after the other by each of the contamination detection devices by each of the three light sources 11, 13 and 15 of each contamination detection device 3. This means that lighting with the three primary colors red, green and blue takes place one after the other. All three light sources 11, 13 and 15 can then be active at the same time, so that the coin is illuminated with white light. As already described, both contamination detection devices 3 or their light sources can be switched on at the same time or carry out the measurements one after the other.

When measuring with different colors, the light sources 11, 13, 15 can each have different intensities in order to compensate for differences in the sensitivity of the photo sensor 17 for different colors.

The light reflected by the coin is received by the photosensor 17 of the respective contamination detection device 3 and a signal is generated which is proportional to the intensity of the detected light.

A measured value can be generated from the signal by the control device 27, which can be compared with a comparison value for the respective color in the control device 27. For this purpose, the control device 27 can have a memory unit 51 (not shown) or be connected to it.

The storage unit 51 preferably has comparison values for each contamination detection device 3 separately, since the two contamination detection devices 3 each cover different coin areas. Comparative values are preferably available for each individual color and for different color combinations, especially white.

It is equally advantageous if comparison values are available for each individual coin type. If the coin type was determined during a measurement by the contact image sensor 39 or the eddy current sensor 43, the control unit 27 can call up the values stored for this coin type and compare them with the measured values of the photo sensors 17.

If, for example, a coin was illuminated by both contamination detection devices 3 with the three primary colors and a measured value was recorded for each lighting process, then there are six measured values. Each of these six measured values can be compared with two comparison values by the control device 27. The comparison values can represent a range of light intensity that characterizes a coin as still fit for circulation.

If each of the measured values lies between the two respective comparison values, a signal can be generated and output via a signal output (not shown) of the control device 27, which identifies the coin as fit for circulation.

On the other hand, if at least one of the measured values lies outside the range defined by the two comparison values, this means that the coin is probably dirty or damaged. In this case, a signal is output via the signal output, which designates the coin as unfit for circulation.

Reference symbols

1

Pollution detector

3

Contamination detection device

5

Mounting plate

7

Distance

9

RGB LEDs

11

light source

13

light source

15

light source

17

Photosensor

19

Phototransistor

21

connecting element

23

Plug

25

Bottom of the mounting plate

27

Control device

29

Remanence sensor

31

AMR sensor

32

Coin sorting machine

33

Housing

35

Coin transport route

37

rail

38

Coin transport direction

39

Contact image sensor

41

Trigger sensor

43

Eddy current sensor

45

Trigger sensor

47

delay element

49

Baseline

51

Storage unit

Claims (11)

1. A contamination detector (1) for determining the suitability for circulation of coins, in particular for a coin sorting machine, wherein the contamination detector (1) comprises at least one control means (27) and two contamination detecting means (3), each having at least one photosensor (17), wherein in particular the two contamination detecting means (3) each further include at least two light sources (11, 13, 15) of different colors, wherein the contamination detector comprises at least one coin transport path (35) for transporting coins, and wherein the contamination detecting means (3) are arranged along the coin transport path (35) and are spaced perpendicularly thereto, a first contamination detecting means (3a) being arranged at the level of a ring/core transition region of a 1-euro coin and a second contamination detecting means (3b) being arranged at the level of the diameter of a 2-cent coin above a base line (49) of the coin transport path (35), characterized in that the two contamination detecting means (3) are arranged on a common circuit board (5).
2. The contamination detector (1) according to claim 1, characterized in that at least one of the contamination detecting means (3) includes exactly two RGB LEDs (9), each comprising three light sources (11, 13, 15) for generating visible light of the colors red, green and blue.
3. The contamination detector (1) according to claim 1 or 2, characterized in that at least one of the photosensors (17) is a phototransistor (19).
4. The contamination detector (1) according to any one of claims 1 to 3, characterized in that the contamination detector (1) comprises at least one trigger sensor (41, 45) connected to at least one of the contamination detecting means (3) and configured to trigger a measurement process in the contamination detecting means (3).
5. The contamination detector (1) according to claim 4, characterized in that the contamination detector (1) comprises a connection to at least one further coin sensor (39, 43) which is also connected to the at least one trigger sensor (41, 45).
6. The contamination detector (1) according to claim 5, characterized in that a delay element (47) is provided between the at least one trigger sensor (41, 45) and the at least one contamination detecting means (3) for delaying the triggering of the measuring process.
7. The contamination detector (1) according to any one of claims 1 to 6, characterized in that the contamination detector (1) enables a throughput of 1 to 5000 coins/minute.
8. The contamination detector (1) according to any one of claims 1 to 7, characterized in that the first contamination detecting means is arranged to cover at least a range between 1 and 5 mm above the baseline and the second contamination detecting means is arranged to cover at least the range between 16.75 and 20.75 mm above the baseline.
9. A coin sorting machine (32) for sorting coins at least according to their suitability for circulation, characterized in that the coin sorting machine (32) comprises at least one contamination detector (1) according to any one of claims 1 to 8.
10. A method for detecting contamination of coins, in particular for detecting the suitability for circulation of coins, wherein a contamination detector (1) is employed comprising two contamination detecting means (3), each comprising at least two light sources (11, 13, 15) and at least one photosensor (17) for detecting the light of the light sources (11, 13, 15) reflected at a coin, characterized in that a coin is illuminated with at least two different colors of visible light by the at least two light sources (11, 13, 15), the light reflected by the coin is detected by the at least one photosensor (17) of the associated contamination detecting means (3), and the measured intensity of the reflected light is compared with at least one reference value previously stored in a memory unit (51) by a control means (27), wherein the contamination detector (1) is designed according to one of claims 1 to 8.
11. The method according to claim 10, characterized in that the at least one reference value is selected depending on the previous output of least one further coin sensor (39, 43).

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