EP1096432A2 - Device for counting and/or sorting coins - Google Patents

Abstract

Optical devices have a light source (6) and light-sensitive sensor devices (7) set opposite a coin's (1) main surface to convert contact light into electrical signals. The sensor devices are designed as a CCD element. The light source has an emitting source (8) and optical elements to create a parallel bundle of light rays orthogonal to a coin's main surface.

Description

The invention relates to a counting device and / or sorting coins in random order with the edge against a leading edge on a guideway be promoted with a coin recognition unit having optical means for determining coin diameters, the optical means being a light source and, in relation to a main surface of the coin, opposite the coin photosensitive sensor means, which incident Convert light into electrical signals, exhibit.

A device of the construction mentioned at the outset is known for example from reference DE-2547685 C2. In the device known in this respect, the Illumination of the coin using one or more difusers Light sources. On the main illuminated area of the The opposite side of the coin is a sensor means set up which has a variety of light guides which is substantially along a perpendicular arranged to the conveying direction line are. The light guides are each with a photocell optically connected. Now a coin runs over the line of the Light guides, so it covers and shades from a maximum a certain number of light guides. From the or the The information can therefore be shaded by light guides get that the passing coin has a diameter whose value is between the distance of the outermost shaded light guide from the leading edge and the distance of the innermost unshaded one Has light guide from the leading edge. That so The signal obtained and evaluated can then be used for sorting of the coins going through.

The device known in this respect has been put into practice proven excellent, but is in terms of equipment Effort for improvement. On the one hand it is Manufacture of a light guide holder with a plurality of exact positioning of the light guides. Furthermore, such a device can not be without use another to count different currencies. This is because ultimately none Diameter is determined, but a diameter range. However, different currencies have different coins with various diameters, so that usually with a light guide holder at most two or three currencies can be covered, because for each individual "allowed" Diameter one or two associated light guides must be set up.

In contrast, the invention is the technical problem based on a device for counting and / or sorting of coins, which are less expensive to build and nevertheless for a variety of currencies without changing from structural facilities can be used.

The invention teaches to solve this technical problem a device for counting and / or sorting coins, the in random order with the edge on a leading edge to be carried on a guideway with a coin recognition unit having optical means for the determination of coin diameters, the optical Means a light source as well as, based on a Main surface of the coin, photosensitive to the coin Sensor means, which incident light in electrical Convert signals, having the sensor means is designed as a CCD element, the light source an emission source and optical elements for generation a parallel and orthogonal to a major coin surface has standing light beam, the lateral Extent of the light beam as well as the arrangement of the CCD element according to the coin diameter to be recognized are set up in such a way that a Only part of the CCD element can be shaded by the coin is. Within the scope of the invention, each is a CCD element denotes optoelectronic element, which is a plurality of independent photosensitive pixels, which are individually readable electronically. The pixels can be one-dimensional (straight or curved) or two-dimensional (flat or one-dimensional or two-dimensional curved).

By using a CCD element, little can be done Very high resolution, e.g. 15 pixels or "dots" per mm. Comparatively with that very high resolution are also only in strictness Diameter ranges and no exact diameter determined, these reduced diameter ranges in the frame However, a measurement is so small that it is practical can be assigned to a discrete diameter value. As a result, the diameter can be practically any Coin can be determined with one and the same CCD element. Therefore, different currencies can only by supplementing or exchanging evaluation software to be edited. The high achieved with the invention Accuracy in the detection of diameters is based but not solely on the use of a CCD element. Rather, it is just as important that, in contrast to the State of the art, the lighting of the coin with a parallel light beams. Because diffuse Light would lead to "soft" transitions in the shade Area of the coin edge lead due to the spatial Extension of the coin in the direction orthogonal to the Main coin surface.

Particularly simple and inexpensive to carry out is an embodiment of the invention in which the Emission source as LED, preferably in the wavelength range Emit 640 to 980 nm, is formed. In particular working with an emission source emitting in the IR range is possible.

A parallel beam of light can be used, for example by making the light source in focus of a parabolic mirror or in the focus of the Parabolic mirror mapped with other optical means is.

Interfering shadows and / or emissions from the emission source can be avoided that the curvature of the parabolic mirror a segment of a parabolic load follows, i.e. does not include the base point.

Basically, the invention can be done in different ways function. In a comparatively complex embodiment of the invention, the CCD element is a CCD surface element, i.e. with an extension in both directions a plane parallel to a major coin surface. In this embodiment, one can Reading the CCD area element a coin edge contour segment are photographed as it were, then using evaluation software the coin diameter with accuracy can calculate which with suitable algorithms is still below the resolution of the CCD surface element. In such an embodiment would have the parabolic mirror have a double curved surface, i.e. an area segment of a paraboloid of revolution. Corresponding applies if an optical converging lens is used, as described below. Let with this embodiment there are also special coin edges that deviate from the circular shape recognize their special shape in the sort function as an additional input variable (next to the "diameter") can come in.

In comparison, it is simple but in practice it is satisfactory embodiment is the CCD element a CCD line arranged orthogonally to the conveying direction, their extension line in one to a main coin surface parallel surface is arranged. The parabolic mirror can then be used as a simply parabolic curved surface one, based on the curvature, lateral extension of less than 10 mm, preferably less than 5 mm, maximum preferably as 3 mm, one according to the extension of the CCD line form an aligned light line of appropriate width, be executed.

As an alternative to using a parabolic mirror, the Light source in the focus of an optical converging lens lie or in the focus of the optical converging lens be pictured. Then mirrors are not needed.

The optical converging lens can then be simply, e.g. cylindrical or rod-shaped, curved surfaces with an extension in the direction orthogonal to the optical axis and orthogonal to the curvature of less than 10 mm, preferably less than 5 mm, most preferably less than 3 mm, one aligned according to the extension of the CCD line Forming a line of light of appropriate width.

A lens is designated as an optical converging lens Focal length in optically thinner medium is greater than 0. A converging lens can be symmetrical or asymmetrical biconvex, plano-convex or concave-convex. The Lens surfaces can be spherical or aspherical his. If the optical converging lens is simply simple curved surfaces, i.e. a rod lens is, it does not have a focal point, but a focal line on. Otherwise, the above applies in principle. The concept of an optical converging lens does not include only single lenses, but also lens systems, which are overall behave like a converging lens, i.e. a focal length in an optically thinner medium of greater than 0. In such a lens system can therefore diverging lenses can also be provided. During construction and design of the optical converging lens or one corresponding lens systems can be found by those skilled in the art Rules of geometric optics application. The optical converging lens can be made of all usual translucent Materials are formed, in particular glass and / or Plastic. However, training is preferred as a plastic lens. The lens surfaces can be compensated, e.g. to reduce disturbing reflections.

In the embodiment described above with a CCD line, the light line can be narrowed even further, if in the area of a light exit opening Light source is arranged parallel to the light line Rod lens is provided. Optimal results are obtained if the focal point of the rod lens is approximately in the range a center plane between the two main coin surfaces lies. But it is also possible to focus on the Rod lens to be provided in the area of the CCD element. This gives a focusing of the (parallel) light beam in one by the conveying direction and the optical axis of the light beam defined plane. In an orthogonal and parallel to the optical Axis of the plane of the beam of light remains maintain the parallelism. Through that achievable Narrowing of the light line can cause edge effects be reduced when going through coins.

A device according to the invention can be used in a wide variety of ways Wise be educated. So it is possible in immediate area of the CCD element, for example immediately before that, based on the direction of conveyance To set stop element to block the sequence of coins, the stop element being as by a bistable magnet driven locking pin is formed, which in a Position of the magnet releases the guideway and in the other position of the magnet blocked. Furthermore can a deflection element for sorting out the coin recognition unit of coins with a given diameter value deviating diameter connected downstream be, the deflecting element by means of a bistable Magnet is driven. Such deflection elements are out the prior art in connection with an ejection opening known and in this respect reference is made to it.

The use of bistable magnets described above has the advantage that compared to monostable magnets with return spring comparatively low electrical Benefits for actuation are needed. Also are the response times are short and independent of any Aging processes in spring elements.

The locking pin can be essentially rod-shaped with a major axis orthogonal to the guideway. The actuation the magnet then takes the form that the Pin is moved towards its major axis, taking it only in one of its two positions in the guideway protrudes. When using a bistable magnet insofar also advantageous that the holding current in the blocking position acts like a feather. This has to Consequence that a located above the activated locking pin Coin is not thrown out of its guideway. Rather, it slides along the end of the locking pin and the locking pin only pivots into the guideway, when the coin releases it. Alternatively or additionally For this purpose, the locking pin can be in the direction of the main axis of the locking pin have compression spring-loaded locking element, which is exercised according to the above Function causes.

In the case of the deflecting element, it is understood that in one Evaluation electronics the period is taken into account which between the detection of an undesired diameter through the optical means and reaching the concerned Coin of the deflecting element lies. This Time period is essentially dependent on the conveying speed determined and can vary accordingly with this.

The invention further relates to a method for determination of coin diameters, with coins in random Follow with the edge against a leading edge a guideway through a coin recognition unit according to the invention are promoted, with the CCD line at Passage of a single coin is read out several times, a degree of shading is determined for each reading and a shadow degree sequence for the single coin in a storage element is stored, with decreasing Degree of shadowing during the passage of a coin the previously determined maximum degree of shading as a diameter value retrieved from the storage element and as an input variable a sorting function is used. A special one high interference immunity during measurement and reading The CCD line is possible when the light source is on of the read cycle is switched dark.

In contrast, when using a CCD surface element no multiple triggering of the CCD element required. Because here a single "momentary exposure" is sufficient Determination of an edge segment and consequently for calculation of a coin diameter. Here it can be recommended to let the emission source work as a pulse source, so that the recorded edge contour does not depend on the progress of the funding as it were washed out.

Fig. 1

eine schematische Explosionsdarstellung einer erfindungsgemäßen Vorrichtung im Bereich der optischen Mittel zur Bestimmung von Münzendurchmessern und

Fig. 2 a+b

einen Querschnitt im Bereich der Lichtquelle (a) bzw. eine perspektivische Darstellung der Lichtquelle (b) und

Fig. 3

eine zum Gegenstand der Fig. 2 alternative Lichtquelle.

In the following, the invention is explained in more detail with reference to figures that represent only one exemplary embodiment. Show it:

Fig. 1

a schematic exploded view of a device according to the invention in the field of optical means for determining coin diameters and

2 a + b

a cross section in the region of the light source (a) or a perspective view of the light source (b) and

Fig. 3

an alternative to the subject of Fig. 2 light source.

A device for counting can be seen in FIG and / or sorting coins 1 in random order with the edge 2 resting on a leading edge 3 on a Guideway 4 are promoted. This happens with Help of the conveyor belt 19. For this, in addition to a comparative consideration with Figure 2a referenced. Intended have a coin recognition unit 5 optical means for determining coin diameters d. The optical means have a light source 6 and, related on a main coin surface, opposite the coin photosensitive sensor means 7, which incident Convert light into electrical signals. The sensor means 7 is in the exemplary embodiment as orthogonal to Direction of delivery arranged CCD line 7, its extension line in a parallel to a major coin surface Surface is arranged, formed. The CCD line is 7 immediately below a light passage opening 16 in the Guide track 4 arranged, for example on a circuit board 17 with other electronic components.

In a comparative examination of FIGS. 1 and 2 you can see that the emission source designed as LED 8 via a cylindrical lens 18 in the focal point B one Parabolic mirror 11 is shown. Between the cylindrical lens 18 and the parabolic mirror 11 can also be a Pinhole (not shown in the figures) is provided to be aberrations due to the non-punctiform To minimize emission source and the cylindrical lens 18. In the exemplary embodiment, the parabolic mirror 11 is simple parabolically curved surface (i.e. no surface segment of a rotary hyperbolic) with one, based on the curvature, lateral extension of less than 5 mm, one aligned according to the extension of the CCD line Line of light of corresponding width executed. It is understood that the light source 6 shown in the Practice closed on both sides and with inner walls (with the exception of of the optical elements) is black. In the Figures is for the purpose of better understanding only a side cover has been omitted. You can see that the curvature of the parabolic mirror 11 a segment follows a parabolic load. The orientation of the parabolic mirror 11 is such that the optical axis of the Emission source 8 substantially orthogonal to the optical Axis of the light exit opening 12 is. In the field of Light exit opening 12 can be parallel to the light line arranged rod lens 13, which the Width of the light line in the area of a coin to be recognized 1 reduced.

A stop element 14 can also be seen in FIG. 1 for blocking the sequence of coins, the stop element 14 than driven by a bistable magnet 15 Lock pin 14 is formed, which is in one position of the magnet 15 releases the guideway 4 and in the other position of the magnet 15 blocked. In the illustrated The operating state is the guideway 4 Approved.

In the exemplary embodiments, a is determined Coin diameter as follows. When going through a single one CCD line 7 is read out several times from coin 1. At a degree of shading is determined for each reading. The so resulting degree of shading for a single coin is stored in a storage element. With decreasing Degree of shading in the course of this sequence of degrees of shading in the course of the passage of a coin 1, the previous one determined maximum degree of shading as diameter value d retrieved from the storage element and as an input variable a sort function used. It is understood that the Sorting function one or more predefined or adjustable Diameter values saved contains and that for example a deflection element in accordance with a comparison a currently measured diameter value d with a predetermined diameter value activated or deactivated becomes.

FIG. 3 also shows a device such as basically described for Figure 1. In this embodiment was a CCD line of the type IL-CC 1024 the Dalsa company uses which in a straight line arrangement 1024 sensor elements (dots or pixels) with a density of approximately 72 dots per mm. You can see in deviation to the above embodiment, that the trained as an LED Emission source 8 in the focal point B of an optical Converging lens 11. In this embodiment is the optical converging lens 11 with simply curved Surfaces (i.e. no surface segment of a body of revolution) with a lateral extension in relation to the curvature less than 5 mm, one according to the extent line of light aligned corresponding to the CCD line Made width forming. It is understood that the illustrated Light source 6 closed on both sides in practice and inside wall (with the exception of the optical elements) is black. In the figure are only for The side covers have been omitted for better understanding been. The orientation of the optical converging lens 11 is such that the optical axis of the Emission source 8 essentially colinear to the optical Axis of the light exit opening 12 is or with this matches.

In this embodiment, the determination is made Coin diameter basically as before described.

Basically, the CCD element can be wavelength-dependent Sensitivity characteristics so matched be that the sensitivity maximum in the range of the emission spectrum the light source, preferably at the maximum, lies. For this purpose, the light source and / or suitable filters of the CCD element can be provided. The The light source can also be operated with (amplitude) modulation then, the signal arising in the CCD element processed with the modulation frequency for evaluation becomes. In this way, the influence of extraneous light is minimized.

Claims (11)

Device for counting and / or sorting coins (1), which are conveyed in a regular sequence with the edge (2) resting on a guide edge (3) on a guide track (4), with a coin recognition unit (5) having optical means for determination of coin diameters (d),
wherein the optical means have a light source (6) and, based on a main surface of the coin, light-sensitive sensor means (7) opposite the coin (1), which convert incident light into electrical signals, the sensor means (7) as a CCD element (7 ) is trained,
The light source (6) has an emission source (8) and optical elements (9, 10) for generating a light beam parallel and orthogonal to a main coin surface, the lateral extension of the light beam and the arrangement of the CCD element (7) as required coin diameter (d) to be recognized are set up such that only a part of the CCD element (7) can be shaded by a coin (1) to be recognized. The device of claim 1, wherein the emission source (8) as LED, preferably in the wavelength range 640 emitting up to 980 nm. Apparatus according to claim 1 or 2, wherein the light source at the focal point (B) of a parabolic mirror (11) lies or in the focal point (B) of the parabolic mirror (11) is shown. Device according to one of claims 1 to 3, wherein the curvature of the parabolic mirror (11) one Parabolic load segment follows. Apparatus according to claim 1 or 2, wherein the light source (6) at the focal point (B) of an optical converging lens (11) or in the focus (B) of the optical converging lens (11) is shown. Device according to one of claims 1 to 5, wherein the CCD element (7) is orthogonal to the conveying direction arranged CCD line (7), the extension line in a surface parallel to a major coin surface is arranged, wherein the parabolic mirror (11) as simply parabolic curved surface with a, related on the curvature, lateral extension of less less than 10 mm, preferably less than 5 mm, maximum preferably as 3 mm, one according to the extension of the CCD line (7) aligned light line corresponding Is designed to form width or being the optical Converging lens (11) simply curved surfaces with a related to the curvature, lateral extension of less than 10 mm, preferably less than 5 mm, most preferably as 3 mm, one according to the Extension of the CCD line (7) aligned light line corresponding width is executed forming. Device according to one of claims 4 to 6, wherein in Area of a light exit opening (12) of the light source (6) one arranged parallel to the line of light Rod lens (13) is set up, which is the width of the Light line in the area of a coin to be recognized (1) reduced. Device according to one of claims 1 to 7, wherein in immediate area of the CCD line (7) a stop element (14) set up to block the sequence of coins is, the stop element (14) as by a bistable Magnet (15) driven locking pin (14) is formed, which is in a position of the magnet (15) releases the guideway (4) and in the other Position of the magnet blocked. Device according to one of claims 1 to 8, wherein the coin recognition unit (5) has a deflecting element for Sorting out coins of a given diameter value deviating diameter value in terms of conveyor technology is connected downstream, the deflecting element by means of a bistable magnet is driven. Method for determining coin diameters (d), coins (1) in random order with the edge (2) on a leading edge (3) on a Guideway (4) through a coin recognition unit (5) are promoted according to one of claims 1 to 9, the CCD line (7) when passing through a single Coin (1) is read out several times, with each Reading determines a degree of shading and a sequence of degrees of shading for the single coin in one Storage element is stored, with decreasing Degree of shading in the course of passing one Coin (1) the previously determined maximum degree of shading as diameter value (d) from the storage element retrieved and as the input variable of a sort function is used. The method of claim 10, wherein the light source during of the read cycle of the CCD line (7) is switched dark becomes.

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