EP2879542B1 - Method for testing the coin - Google Patents

Description

The invention relates to a method for checking a coin according to claim 1.

So-called bicolor coins, which consist of an inner core and an outer ring surrounding the core, have been in use around the world for a long time. The core and outer ring are made from various metallic materials. Out DE 10 2010 013 148 It is also known to add an additional material component to the coin in the form of a central ring. The middle ring, which is made from a polymer or a composite material, is electrically insulating and firmly connected to the outer ring and core.

The testing of bimetal coins is mainly carried out using electromagnetic measuring methods. It has been found that the contact resistance between the core and the outer ring, for example due to corrosion, leads to a falsification of the measurement results. The greater the potential differences for the metals or alloys used, the stronger the falsification effect.

In the cited document it is also described that the middle ring should consist of a transparent, semitransparent, opalescent and / or color effect-producing material. The width of the middle ring is given as preferably between 0.5mm and 3mm.

In addition to improving the verifiability of these coins by electromagnetic means, an improved distinguishability from other conventional coins is also achieved. For example, the user can easily recognize a transparent central ring by looking at it.

A coin is described that can be easily detected with the aid of optical arrangements. The invention is also based on the object of specifying a method with which the coins having a central ring can be detected in a simple and effective manner.

This object is achieved by the features of claim 1.

The coin according to claim 1 is characterized in that the middle ring is permeable to electromagnetic waves of a first wavelength range and / or less permeable or impermeable to a second wavelength range.

If such a coin runs through a light barrier, for example, the number of light barrier signals or the number of light barrier interruptions can be counted for the middle ring. At the same time, the individual times of light interruption or light permeability can be recorded in the form of signal changes or signal durations. The presence of the transparent or translucent ring can be detected from the signal sequence, and the individual widths of the outer ring, the translucent middle ring and the metallic core can be determined from the recorded times.

According to one embodiment of the invention, the material of the middle ring is transparent to the visible wavelength range. According to another embodiment of the invention, the material of the middle ring is transparent to the invisible wavelength range. According to a further embodiment of the invention, the material of the middle ring is translucent for the visible and invisible wavelength range and impermeable for one or certain Wavelength ranges of visible or invisible light, especially for the IR range. The latter embodiment of the invention is particularly preferred. The reason is that presence light barriers in coin checking devices normally work with IR light. If the middle ring is made of transparent material, but is not transparent to IR light, then the sensor arrangement, which is sensitive to both IR light and visible light, responds differently when a coin moves through the optical arrangement and the sensor arrangement is irradiated free of obstacles or not free of obstacles. On the other hand, it is within the scope of the invention to provide the impermeability of the material for the middle ring also for a visible wavelength range, for example for the red range.

According to another embodiment of the invention, the material of the middle ring is translucent for the visible wavelength range and impermeable for at least one specific wavelength range of visible light. Another embodiment of the invention provides that the material of the middle ring is translucent for the invisible wave range and permeable for at least one specific wave range of visible light.

All described possibilities of permeability or non-permeability for electromagnetic waves in the visible or invisible range allow simple methods for discriminating coins that are provided with a central ring made of electrically insulating material that is permeable to at least a limited spectral range of light.

According to another embodiment of the invention, the middle ring has a different reflection factor than the core or the outer ring. The reflection properties of the coin surfaces can also be determined with the help of an optical Detect the arrangement if it is different from that of the outer ring or the core. For example, the middle ring can reflect more strongly than the core or the outer ring. It is also understood that additional optically detectable properties of the middle ring can be detected with the aid of a suitable optical arrangement, for example color pigments, UV stabilizers, fluorescent or holographic particles, etc.

The method for testing a coin with a central ring made of electrically insulating material is based on an optical arrangement through which the coins move and generate a signal that is evaluated in an evaluation device to generate a real or false signal. According to the invention, the coins are irradiated by at least one optical transmitter, and an optical arrangement receives the light passing through it from the central ring, and an evaluation device generates a signal when the coins are moved through the sensor arrangement. If the material of the middle ring is transparent, for example, light in the visible wavelength range is allowed to pass through the middle ring and can strike the sensor arrangement and generate a corresponding signal there. If the middle ring is permeable to light in the invisible wave range and the sensor arrangement is sensitive to this light, a signal can also be generated when invisible light from the light source or the optical sensor passes through the material of the middle ring and strikes the sensor arrangement. For example, a light barrier transverse to the direction of travel of the coin can be provided and the evaluation device counts the number of signal changes when the coin passes through the light barrier, whereby at the same time the individual times of light interruption or light transmission are recorded over the signal duration.

According to one embodiment of the invention, the evaluation device analyzes the signal from the sensor arrangement and generates a real signal when the spectrum of the received light corresponds to the material of the middle ring of a real coin. If, for example, white light is generated by the optical sensor, a spectral analysis on the side of the sensor arrangement can be used to determine whether the spectrum of the light transmitted corresponds to that which is usually caused by the material of the middle ring of a real coin. Under certain circumstances, it is determined from the analysis whether the light from the optical transmitter has an invisible component or not, in order to check, for example, whether the material of the middle ring is impermeable to the invisible light.

When electromagnetic waves or light are mentioned above and below, this is understood to mean light in the wide range of the visible and invisible spectrum, as far as it can be processed with the conventional and currently available elements and devices without protective measures.

According to one embodiment of the invention, the sensor arrangement is sensitive to at least one limited wave range. According to another embodiment of the invention, the sensor arrangement is sensitive to a wavelength range of visible light. Alternatively, the sensor arrangement can be sensitive to a wavelength range of invisible light. According to another embodiment of the invention, the sensor arrangement is sensitive to a wavelength range of visible and a wavelength range of invisible light.

It is also possible, instead of starting from the selective sensitivity of the sensor arrangement itself, to connect one or more filters in front of it which determine which Allow or block wavelength ranges of the light from the optical transmitter.

The sensor arrangement contains at least one sensor element, for example in the form of a phototransistor. According to one embodiment of the invention, two or more sensors can also be provided. Instead of providing sensors with a narrow field of view, according to one embodiment of the invention, it is conceivable to use an area or line sensor. For this purpose, a light source is used, for example, on one side of the coin channel, which emits light of the transparent and blocked wavelength range, for example white light. On the opposite side there is a light-sensitive area or line sensor. This sensor is preferably at least as wide as the width of the central ring of the coin. As a rule, this ring width will be 1.0mm to 1.5mm. The light-sensitive sensor arrangement is designed in such a way that it detects the two wavelength ranges, namely that of the permeable light and also that of the blocked wavelength range, or visible and invisible light. In the idle state, the sensor arrangement detects both wavelength ranges because there is no object between the transmitter and the receiver. If, on the other hand, the coin with the middle ring rolls past the sensor arrangement, all wavelengths are initially blocked by the metallic outer ring. If the special material of the middle ring passes the sensor arrangement, only the blocked wavelength range is absorbed, eg the IR range and not the other wavelengths. This is then an evaluable feature that is used to check or discriminate against the coins. If, in the process described, the core moves past the sensor arrangement, all wavelengths are blocked again. Then the middle ring on the sensor arrangement is passed at a second point and finally the second side of the metallic outer ring.

With the aid of the photosensitive sensor arrangement described, the size of the entire irradiated area can be determined, as well as the width of the individual components of the outer ring and core.

According to one embodiment of the invention, the signals from the sensor arrangement are used to determine the mechanical dimensions of the coins, in particular the width of the outer ring, the width of the middle ring, the diameter of the core and the diameter of the coin.

The simplest optical arrangement for checking the three-part coins can consist of a single light path. According to one embodiment of the invention, it is preferred to move the coins through two optical paths, each having an optical transmitter and an optical sensor, for example one path working with wavelengths of the visible and the other with wavelengths of the invisible spectral range. In the case of a light source that emits light in both the visible and the invisible range, for example, both optical sensors are activated when they receive the light. If the middle ring is made of a material that is not transparent to the invisible light, only one sensor of the two optical paths receives light when the middle ring is moved through the two optical paths.

Alternatively, provision can also be made to make the sensor arrangement sensitive to wavelengths in the visible and invisible range at the same time and to activate the optical sensor one after the other in order to generate light in the visible range and light in the invisible range. According to one embodiment of the invention, two optical transmitters can be used for this purpose. In the end it is also conceivable to switch the optical sensor differently briefly one after the other, that is to say to be sensitive to limited wavelength ranges.

Fig. 1A

zeigt eine Draufsicht auf eine Münze aus drei Materialien.

Fig. 1B

zeigt einen Schnitt durch die Darstellung nach Fig. 1A entlang der Linie B-B.

Fig. 2

zeigt schematisch eine Münze nach den Fign. 1A und 1B beim Durchlaufen von zwei Lichtschranken L1 und L2.

Fig. 3

zeigt die Ansprache der Lichtschranken für unterschiedliche Materialien des mittleren Rings der Münzen.

Fig. 4

zeigt eine ähnliche Anordnung wie Fig. 2 mit zwei Lichtschranken übereinander.

Fig. 5

zeigt im Schnitt eine optische Anordnung zur Durchführung des erfindungsgemäßen Verfahrens.

Fig. 6

zeigt eine ähnliche Anordnung wie Fig. 2 mit einem Zeilen- oder Flächendetektor für die optische Anordnung.

Fig. 7

zeigt im Schnitt die optische Anordnung entsprechend Fig. 6 zur Durchführung des erfindungsgemäßen Verfahrens.

The invention is to be explained in more detail below with reference to drawings.

Figure 1A

Figure 10 shows a top view of a three material coin.

Figure 1B

shows a section through the representation according to Figure 1A along the line BB.

Fig. 2

shows schematically a coin according to the Figs. 1A and 1B when passing through two light barriers L1 and L2.

Fig. 3

shows the activation of the light barriers for different materials of the middle ring of the coins.

Fig. 4

shows an arrangement similar to Fig. 2 with two light barriers one above the other.

Fig. 5

shows in section an optical arrangement for carrying out the method according to the invention.

Fig. 6

shows an arrangement similar to Fig. 2 with a line or area detector for the optical arrangement.

Fig. 7

shows in section the optical arrangement accordingly Fig. 6 for carrying out the method according to the invention.

In the Figs. 1A and 1B a coin consisting of three parts is shown, namely with a core 1 made of a first metallic material, an outer ring 2 made of a second metallic material and a middle ring 3 made of an electrically insulating material, for example a polymer. In addition, the material of the middle ring 3 can be translucent or transparent. The thickness of the core 1 is dd and the thickness of the outer ring 2 is dr.

In Fig. 2 a coin track 20 is shown rolling along the coin 10. Two light barriers L1 and L2, which have a height h above the coin track 20, are arranged at a distance a. The light barriers consist, for example, of at least one optical transmitter and an optical receiver or sensor on different sides of the path of the coin 10. The light barrier L1 works with light in the visible wavelength range, and the light barrier 2 works in the IR wavelength range. While the coin 10 passes the light barriers L1 and L2, time recordings are made with the interruptions of the light barriers. The interruption takes place for the first time with the edge of the coin 10 entering the light barrier L1 and sets the point in time t0 in Fig. 3a At this moment, both wavelength ranges (transparent and non-transparent) are blocked. However, if the edge of the transition from the metallic outer ring to the middle ring passes the light barrier L1, the permeable wave range is detected by the optical sensor of the light barrier L1, which is represented by time t1. With the transition from the middle ring to the metallic core, both wavelength ranges are blocked again. This occurs at time t2. As the second half of the coin 10 continues to pass, the times t3, t4 and t5 are determined analogously. The individual ring widths or the core diameter and the entire coin diameter can be determined from the determined time segments t0 to t1, t1 to t2, t2 to t3, t3 to t4 and t4 to t5. Such provisions are known per se, as in DE 27 24 868 , EP 0 839 364 and EP 0 694 888 disclosed. The determined individual ring widths can be used as security features.

The light barrier L2 is positioned at the same distance from the track 20 as the light barrier L1, and the distance L1 to L2 is known. The mechanical distances between the coins can be calculated from these specifications. The light barrier L2 is designed for a certain wavelength range, for example infrared light. For this specific wavelength range, no signal changes are now detected at t11 and t12, t13 and t14, but only again at t15 when the entire coin 10 has passed the light barrier L2 because the material of the middle ring does not let the IR light through from the graphic representation of Fig. 3a below. Figure 3b shows the process when a coin is tested with a material of the middle ring, which is transparent to IR light. It can be seen that the same signal curves are then generated for the light barriers L1 and L2. This is therefore a good discriminatory feature for identifying coins that have been provided with the wrong material for the middle ring.

Figure 3c shows the signal curve for the two light barriers L1 and L2 for a conventional bicolor coin as well as for a coin provided with a central ring, where the material for the central ring is impermeable to both visible and invisible light.

• Material mittlerer Ring mit durchlässigem sichtbarem Licht
• Material mit gesperrtem IR-Licht
• Breiten des Außenrings links und rechts
• Breite des Materials des mittleren Rings links und rechts
• Kerndurchmesser

Overall, the following security areas are recognizable:

• Medium ring material with permeable visible light
• IR light blocked material
• Widths of the outer ring left and right
• Width of the material of the middle ring left and right
• core diameter

In Fig. 4 are four light barriers each consisting of an optical transmitter and an optical receiver, which are labeled 11 or 11 'and 12 or 12', arranged one above the other at a distance h or h 'from the coin track 20 and at a distance a from one another. If a conventional coin with a smaller diameter moves through the light barriers 11 and 12, a signal curve t1 and t2 is generated. For a coin with a larger diameter, similar signal profiles are also generated by the light paths 11 'and 12'. If, on the other hand, the light barriers are at the level of a middle ring according to Figure 1A or 1B , in turn, similar signal profiles for 11 and 12 and 11 'and 12' can be generated as these in connection with Fig. 3 have been described.

In Fig. 5 a main plate 30 and a pivot plate 32 are shown, the latter forming the coin track 20. An LED 34 is embedded in the plate 32 and irradiates a coin 10 when it runs along the track 20 along the LED. In the main plate, a phototransistor 36 is arranged, which interacts with an optical element 38, which generates a lens effect and with a small diameter section 40 in a recess 42 of the main plate 30 and receives the light generated by the LED, as far as it either is not blocked by the coin 10 or allowed through by a portion of the coin 10, as is the case in connection with the figures described above.

Instead of a point-shaped receiver for the light from the LED 34, a line or area sensor can also be provided in a vertical and / or horizontal arrangement, as shown at 44 or 46 in FIG Fig. 6 is shown. In Fig. 7 the line sensor 46 is shown in a horizontal arrangement, which is controlled by the LED 34 via the entire width is irradiated and in this way to receive light from the LED 34, which is either not blocked by the coin or is allowed through by this.

Claims (13)

1. Method for testing coins having a core (1) made of a first metal, an outer ring (2) made of a second metal and a ring (3) arranged between the core (1) and the outer ring (2), with the ring being made of electrically insulating material that is transmissive for light for a first wavelength range and is opaque or less transmissive for light for a second wavelength range, in which method the coins are moved through an optical arrangement and signals in the optical arrangement are evaluated by an evaluation apparatus for generating an authenticity or forgery signal, wherein the coins are irradiated with light by an optical transmitter, and an optical sensor arrangement receives the light passing through the central ring (3), and the evaluation apparatus analyses the signal of the sensor arrangement and generates an authenticity signal if the spectrum of the received light corresponds to the material of the central ring of an authentic coin.
2. Method according to Claim 1, characterized in that the sensor arrangement is sensitive for at least one limited wavelength range.
3. Method according to Claim 1 or 2, characterized in that the sensor arrangement is sensitive for a wavelength range of visible light.
4. Method according to Claim 1 or 2, characterized in that the sensor arrangement is sensitive for a wavelength range of invisible light.
5. Method according to Claim 1 or 2, characterized in that the sensor arrangement is sensitive for a wavelength range of visible light and a wavelength range of invisible light.
6. Method according to Claim 5, characterized in that two sensors are provided.
7. Method according to one of Claims 1 to 6, characterized in that the light is generated by an LED.
8. Method according to one of Claims 1 to 7, characterized in that a phototransistor is used as the sensor.
9. Method according to one of Claims 1 to 8, characterized in that the sensor arrangement uses an area-scan or line-scan sensor.
10. Method according to one of Claims 1 to 9, characterized in that the mechanical dimensions of the coin, in particular the width of the outer ring, the width of the central ring, the diameter of the core and the diameter of the coin, are determined with the aid of the signals of the sensor arrangement.
11. Method according to one of Claims 1 to 10, characterized in that the coins pass through two optical paths made up in each case of an optical transmitter and an optical sensor, wherein one path operates with wavelengths in the visible spectral range and the other operates with wavelengths in the invisible spectral range.
12. Method according to one of Claims 1 to 11, characterized in that the sensor arrangement is sensitive for waves in the visible and in the invisible spectral ranges and the optical transmitter is activated briefly in succession and alternately generates light in the visible spectral range and light in the invisible spectral range.
13. Method according to Claim 12, characterized in that two optical sensors having different sensitivities are used.

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