EP1256909B1 - Apparatus and Method for the Examination of Objects - Google Patents

Abstract

Device for examination of objects (5), especially banknotes, passports or other security documents has a detection arrangement (1) for detection of one or more properties of the object and for generation of a detector signal (S) corresponding to the detected property. The detector (1) and object move relative to each other in a transport direction (T). The detector extends over at least part of the object and has at least two different extensions (A, B) in the transport direction. An Independent claim is made for a method for examination of objects, especially banknotes, passports or other security documents using a detector with different extensions in the direction in which the examination objects are being transported.

Description

The invention relates to a device and a corresponding method for the examination of objects, in particular value, identity or security documents, with at least one detector device for detection at least one property of an object to be examined and for generation at least one of the detected property corresponding detector signal, wherein the detector means and the object are relative to each other can be moved in a transport direction and the detector device extends over at least a portion of the object.

A device of this kind is for example from the European patent application EP 0 413 534 A1. To check one on one Banknote located coded security thread, along which magnetic or luminescent code areas are positioned, becomes the banknote with a transport device past an elongate detector transported. The detector ends with the transport direction a sharp Angle, causing the individual code areas of the security thread be gradually brought into the range of the detector. With a suitable Evaluation electronics can from the timing of the detector signals the coded information is determined.

However, this device is mainly for investigations on security threads suitable. Statements, in particular, about position or condition other types of security features, e.g. round holograms, so-called patches, or surface areas with special electrical, magnetic or optical properties, are with the known device not sufficiently reliable or only using a complex Evaluation electronics possible.

It is an object of the invention to provide a device and a corresponding Specify method, which with a simple structure and simple evaluation a reliable investigation of objects, especially a reliable one Determining the position and / or condition of characteristics in or on objects.

This object is achieved by the device and the method solved according to the independent claims 1 and 15, respectively. advantageous Further developments of the invention can be found in the respectively dependent therefrom Claims.

The invention is based on the idea that over at least one Part of the object area extending detector device at least two has different sized expansions in the transport direction. Under the extent of the detector device is the respective width of the Detector device in the transport direction and / or the respective distance of detector units, which may comprise the detector device, in Transport direction to understand.

A feature located on or in the object, in particular a security or authenticity feature, becomes with the movement of the object in the transport direction at the detector device or at the detector units transported by. The feature then passes through the detector device with the object or the detector units at a location at which the Detector device has a certain width and the detector units have certain distances. Depending on position and / or condition of the feature are the continuous dimensions, i. spread or distances, different, so that the feature varies accordingly long in the area of the detector device or the detector units located. The time duration, the time interval, the signal height or the waveform of the generated detector signals therefore contain Information about the position and / or condition of the feature.

The detector device or the detector units are preferably for Detection of electrical and / or magnetic and / or optical Properties trained. In addition to security or authenticity features With the invention, various other features, e.g. Adhesive strips, inhomogeneities or impurities, on or in the Object to be examined. In principle, the invention is also suitable for Recognition of double and multiple copies or for transport monitoring in banknote processing machines. In addition, with the inventive device encodings are detected, which in Print image of a printed document, in the thickness of a document, e.g. in the form of thickness modulations, or in safety features on or in a document are included.

Fig. 1

a) eine erste Ausführungsform der Erfindung und

b) ein Diagramm mit dem zeitliche Verlauf von zwei Detektorsignalen;

Fig. 2

a) eine zweite Ausführungsform der Erfindung und

b) ein Diagramm mit entsprechenden Detektorsignalen;

Fig. 3

a) bis d) Beispiele für unterschiedliche Formen der Detektoreinrichtung;

Fig. 4

a) eine bevorzugte Ausführungsform der Erfindung und

b) ein Diagramm mit entsprechenden Detektorsignalen;

Fig. 5

a) eine weitere Ausgestaltungsform und

b) ein Diagramm mit entsprechenden Detektorsignalen;

Fig. 6

a) eine Ausführungsform mit fünf Detektoreinheiten,

b) ein Diagramm mit entsprechenden Detektorsignalen und

c) ein Diagramm mit einer Fourier-Transformation der Detektorsignale;

Fig. 7

a) ein Beispiel für eine aus mehreren dreieckförmigen Detektoreinrichtungen zusammengesetzte Vorrichtung und

b) und c) Diagramme mit entsprechenden Detektorsignalen;

Fig. 8

a) eine weitere Ausführungsform der Erfindung und b) bis d) Diagramme mit Detektorsignalen;

Fig. 9

a) eine Ausführungsform zur Bestimmung der Eigenschaften, insbesondere der Breite, eines Sicherheitsfadens und

b) ein Diagramm mit entsprechenden Detektorsignalen.

The invention will be explained in more detail with reference to embodiments shown in FIGS. Show it:

Fig. 1

a) a first embodiment of the invention and

b) a diagram with the time course of two detector signals;

Fig. 2

a) a second embodiment of the invention and

b) a diagram with corresponding detector signals;

Fig. 3

a) to d) examples of different forms of the detector device;

Fig. 4

a) a preferred embodiment of the invention and

b) a diagram with corresponding detector signals;

Fig. 5

a) another embodiment and

b) a diagram with corresponding detector signals;

Fig. 6

a) an embodiment with five detector units,

b) a diagram with corresponding detector signals and

c) a diagram with a Fourier transformation of the detector signals;

Fig. 7

a) an example of a device composed of a plurality of triangular detector devices and

b) and c) diagrams with corresponding detector signals;

Fig. 8

a) another embodiment of the invention and b) to d) diagrams with detector signals;

Fig. 9

a) an embodiment for determining the properties, in particular the width, of a security thread and

b) a diagram with corresponding detector signals.

Fig. 1a) shows a first embodiment of the invention. One to be examined Object 5, for example a value, identity or security document, in particular a banknote, by means of a transport device, which is indicated in the example shown by transport belt 2, in Transport direction T transported to a detector device 1 over. On or in the object 5 to be examined there are features 30 and 40, particular authenticity or security features, with certain physical, in particular electrical and / or magnetic and / or optical, Properties. These properties are provided by the detector device 1 detected while the object 5 passes the detector device 1. In this case, a detector signal S is generated by the detector device 1, which corresponds to the detected properties. From the detector signal S can then in an evaluation 3 statements about the examined Object 5, in particular on the nature and / or position of Characteristics 30 and 40 on the object 5, are derived.

According to the invention, the detector device 1 has parallel to the transport direction T two different large extensions B, i. Wide. In the illustrated embodiment, the detector device 1 has a Contour, which is stepped on one side. Depending on her Position on the object 5, the features 30 and 40 pass through the detector device 1 in places of different extension B, whereby the from the detector device 1 generated by the detector signal S pulses with one each has correspondingly different duration.

The detector device 1 is preferably a sensor for detecting electrical and / or magnetic and / or optical properties.

In the example selected, the detector device 1 constitutes a plate of a Capacitor plate pair, wherein the - in the illustration only schematically indicated - second capacitor plate is behind the object 5 and one of the detector device 1 has a similar shape. Depending on the electrical and / or dielectric property of an object or on or in the feature located on the object changes the capacitance of the capacitor, so that corresponding detector signals can be generated.

The detector device 1 may also be a correspondingly shaped one Polschuh act, which for detecting magnetic properties of the object is suitable and in magnetic contact with a measuring coil stands, which generates corresponding detector signals. The detector device 1 may also be formed as a magnetic head, in which the gap lying between two pole pieces a varying according to the invention Has width B. Also, for the detection of magnetic fields according to the invention shaped detection surfaces on which e.g. Hall probes or magnetoresistive ohmmeter are located.

In addition, the detector device 1 as inventively shaped Detection surface of an optical detector to be formed.

FIG. 1b) shows a diagram of the profile of the detector device 1 generated detector signal S over time t. According to the different ones Extensions B of the detector device 1, each of which Characteristics 30 and 40 are traversed in the transport direction T, are different length pulses S1 and S2 generated. From the respective period Δt1 and Δt2 of the pulses S1 and S2 can thus easily statements derived over the position of the features 30 and 40 on the object 5 become. In this case, the short period of time Δt1 of the pulse S1 leaves it conclude that the feature 30 is on the upper half of the object 5, during the longer period Δt2 of the pulse S2 to a position of the Feature 40 in the lower half of object 5.

The operation of the second embodiment shown in Fig. 2a) The invention is analogous to that described in FIG. The device makes a difference from that shown in Fig. 1a), however, is that the detector device 1 has a continuous contour in the form of a triangle. Analogous to FIG. 1a), features 30, 40 and 50 pass through different ones Position on the object 5 different sizes B the detector device 1.

The pulses S1, S2 and S3 of the generated in the diagram in Fig. 2b) Detector signal S differ according to their time duration .DELTA.t1, .DELTA.t2 or .DELTA.t3, from which to the position of the respective feature 30, 40th or 50 can be closed on the object 5.

The detector device 1 shown in Fig. 1a with a stepped contour allows only the determination of individual position areas in which a feature 30 or 40 is located on an object 5. On the other hand allowed the detector device 1 shown in Fig. 2a), each in the region of Pages of the detector device 1 continuous contour the exact determination the position of a feature 30, 40 and 50 on the object 5 from the respective time duration .DELTA.t1, .DELTA.t2 and .DELTA.t3 of the pulses S1, S2 and S3 of the detector signal S.

From the detector signals S of the devices of FIGS. 1 a) and 2 a), statements about the nature, in particular the shape and / or size, of the features 30, 40 and 50 can be derived in addition to the position. For example, the duration Δt1, Δt2 or Δt3 of a pulse S1, S2 or S3 can also affect the extent d _{T of} a feature 30, 40 or 50 in the transport direction T and the signal height of the pulses S1, S2 and S3, respectively the extent d _{H of} a feature 30, 40 and 50 are closed perpendicular to the transport direction T.

In Fig. 3a) to d) are other examples of detector devices 1 with continuous running contour shown. The selected examples have the form an isosceles triangle, a trapezoid, an ellipse segment or a surface with a concave profile in the region of one side and are, depending on the application, for easy and reliable determination the position and / or nature of certain features particularly suitable.

Fig. 4a) shows a preferred embodiment of the invention, in which the detector device 1 comprises two detector units 10 and 11, which in the transport direction T are arranged one behind the other and two different have large distances A from each other. Each of the detector units 10 or 11 serves to detect properties of the object 5 or of located on or in the object 5 features 30 and 40, as well as Generation of at least one of the detected properties Detector signal S.

The detector signals S can in this case in a common channel of the Evaluation device 3 are summarized or even before the evaluation 3 to a common connection (not shown) between the detector units and the evaluation are placed.

The detector signals S of the two located on the object 5 features FIGS. 30 and 40 are shown in the diagram of FIG. 4b). Passed a feature 30 and 40, the detector units 10 and 11, they produce corresponding Detector signals S, which have individual pulses S1 to S4. The pulses S1 and S2 correspond to the detector signals S, which are the feature 30 caused when passing the detector units 10 and 11, the pulses S3 and S4 are analogous to feature 40.

The duration of the individual pulses S1 to S4 depends primarily on the respective one Width of a detector unit 10 or 11 and the extent of the feature 30 and 40 in the transport direction T from. From the duration of pulses S1 and S2 or S3 and S4 can therefore - analogous to those in Figs. 1a) and 2a) described examples - on the nature of the features 30 and 40, in particular their extent in the transport direction T, be closed.

The time interval Δτ1 or Δτ2 of each of a feature 30 or 40 generated pulses S1 and S2 or S3 and S4 is dependent on the position of the respective feature 30 or 40 on the object 5 perpendicular to the transport direction T. In the illustrated embodiment can therefore by determination the time interval Δτ1 or Δτ2 two pulses S1 and S2 or S3 and S4 in a simple manner to the position of one feature 30 and 40, respectively the object 5 are closed.

Fig. 5a) shows a development of the embodiment shown in Fig. 4a). Instead of a step-shaped detector unit 11 is in In this example, an elongated detector unit 11 is arranged so that these an acute angle α with the transport direction T includes. In analogy to the example described in Fig. 4b) can also be in this embodiment from the time intervals Δτ1 and Δτ2 of the individual pulses S1 and S2 and S3 and S4 of the detector signals S shown in Fig. 5b), the position of a feature 30 or 40 on the object 5. From the Duration of the pulses S1 and S3 or S2 and S4 can also statements on the nature of the features 30 and 40, in particular their Extension in the transport direction T, are derived.

Fig. 6a) shows a further embodiment of the device shown in Fig. 5a). In this example, there are five detector units arranged one behind the other 10 to 14 are provided which different angles α with the Include transport direction T. The individual detector devices are preferred 10 to 14 arranged so that these at a fixed height in each case Transport direction T equal distances A from each other. As a result this equidistant arrangement of the detector devices 10 to 14 have the corresponding detector signals S pulses S1 to S5 or S6 to S10 with same time intervals. This is shown in Fig. 6b). Out For reasons of clarity, the pulses were in the selected representation S6 to S10 are shifted by a constant value towards higher signals. The feature 30 passes through the individual detector units 10 to 14 in one Height at which they have a greater distance A from each other than this is the case in the height of the feature 40. Correspondingly larger are the time intervals of the pulses S1 to S5 shown in Fig. 6b) in comparison to the pulses S6 to S10. As already mentioned in connection with FIG. 4b) and 5b) can be derived from the respective time intervals the pulse is the position, i. the height perpendicular to the transport direction T, of the respective feature 30 or 40 on the object 5 determined.

An advantageous possibility of evaluating the detector signals S provides a Fourier analysis of the detector signals S. This method is in particular then advantageous if the detector signals S of interference or are superimposed on strong noise. For this purpose are by Fourier transformation the respective detector signals S transformed detector signals S ' generates, among other things, the fundamental frequency f1 and f2 of the pulses S1 to S5 or S6 to S10 of the detector signal S determined in a simple manner can be. Fig. 6c) shows the transformed detector signals S 'in the range the fundamental frequencies f1 and f2 of the respective sequence of pulses S1 to S5 or S6 to S10. The determined from the transformed detector signal S ' Basic frequencies f1 and f2 can then be used as a measure of the time interval the individual pulses S1 to S5 or S6 to S10 for determining the position the features 30 and 40 are used. This way will a particularly reliable position determination of the features 30 and 40, respectively reached. In addition, the transformed detector signals S 'in the Range of frequencies above the respective fundamental frequency, in particular integer multiples of the fundamental frequency, to be analyzed, and derive statements about the shape and / or size of the features become.

In Fig. 7a) is an example of a four detector devices 1 comprehensive Inventive device shown. The individual detector devices 1 each have the shape of a triangle and are for generation formed by detector signals S, from which analogous to that in FIG. 2 described example, the location of the features 30 and 40 on the object. 5 can be determined. In addition, it is in this embodiment of the invention possible, from the time sequence of individual pulses S1 to S4 or S5 to S8 (FIGS. 7b and 7c) of different time length, to the position of the respective feature 30 or 40 to close. In particular, can from the difference or the ratio of pulses of different duration, z. B. S1 and S2 or S2 and S3 or S3 and S4, to the exact position of Feature 30 or 40 are closed on the object 5. In principle, in This embodiment also allows a Fourier analysis to periodic Filter out parts from the generated pulse sequence and from it statements derive 30 and 40 on the position and / or condition of the features. In the embodiment shown in Fig. 7a), there are four identical detector devices 1 combined. In principle, it is also possible to have a device from detector devices 1 of different shape and / or size together. Also the distance between the detector devices 1 can be designed variable. In general, one of several detector devices 1 composite "jigsaw" construction of the device possible.

8a) shows an embodiment of the device according to the invention, which in particular to investigate the extent of individual features 51, 52 and 53 is designed perpendicular to the transport direction T and therefore especially suitable for investigations on security threads. Which each extending over a portion of the object 5 individual detector units 10 to 14 are arranged one behind the other in the transport direction T and offset perpendicular to the transport direction T. Only in the middle of the Detector device 1 arranged detector unit 12 extends completely about the object to be examined 5. The information content of the detector signals S, individual detector units, e.g. 11 and 13, perpendicular to the transport direction T partially overlap.

In analogy to the embodiments described in FIGS. 4 and 5 can also in this example the position of a feature on the object 5 from the time interval of the individual detector units 10 to 14 generated detector signals S are determined. In addition, let yourself from the detector signals S statements about the extent of the features Derive 51, 52 and 53 perpendicular to the transport direction T, as shown in the in 8b) to d) detector signals S to be illustrated. So feature 51 only pulses S1 and S3 in the detection units 10 and 12 generates, whereby the course shown in Fig. 8b) of the detector signal S is obtained. Pass the other two features 52 and 53, the detector device 1, the in Figs. 8c) and 8d) generated detector signals S generated. From the presence of individual Pulse S1 to S5 in the detector signal S can therefore be statements in a simple manner on the extent of individual features 51 to 53 perpendicular to Derive transport direction T. This embodiment of the invention is for example to examine objects with broken features, such as banknotes with broken security threads, especially suitable.

Fig. 9a) shows a further embodiment of the invention, which in particular for the examination of elongated features, such as Security threads on banknotes, is beneficial. The detector device 1 is formed stepwise, wherein the perpendicular to the transport direction T running step heights in each case from one step to the next are variable. Analogous to the embodiment shown in Fig. 4a) In addition, a substantially perpendicular to the transport direction T extending detector unit 15, which in the example shown by dashed Lines is indicated, be provided, for example, in addition Information about the position of features on the object 5 too win.

The scheme shown in Fig. 9b) shows the time course of the of Detector 1 generated detector signal S for two different broad security threads 53 and 54. The pulse sequence F1 corresponds to this Detector signal S, which is a thin security thread 54 when passing the Detector device 1 would cause. In the case of a broader security thread 53 results in a correspondingly changed detector signal S. with a pulse sequence F2, which due to the larger lateral overlap each adjacent steps by a certain amount to larger values the detector signal is shifted and beyond due to the less sudden increase or decrease in the transitional area of one Level to the next has a less edged course. Also in this Fall can by means of Fourier analysis of the pulse sequences F1 and F2 to the width the respective security thread 54 and 53 are closed. in this connection In particular, those components in the Fourier spectrum are of interest. which are in the range of a multiple of the fundamental frequency of the pulse sequences F1 or F2 are located. The respective frequency and / or strength of these so-called Harmonics can then be used to determine the width of the examined Security thread 53 and 54 are used.

In the illustrated examples, the detector signals in particular based on the time duration, the time interval or the signal level and / or -form of pulses of the detector signal evaluated. In the sense of the Invention, but it is also possible, the detector signals under consideration a variation of the detector signal, e.g. by differentiating the detector signal, an integral of the detector signal or their combination to evaluate over a certain period of time and from this accordingly Statements about the position and / or nature of features derive.

Claims (19)

1. An apparatus for examining objects, in particular documents of value, identification or security documents, having at least one detector device (1, 10 - 15)

   for detecting at least one property of an object to be examined (5), and

   for generating at least one detector signal (S) corresponding to the detected property,

   wherein

   the object (5) is guided past the detector device (1, 10 - 15) in a transport direction (T), and

   the detector device (1, 10 - 15) extends over at least a partial area of the object (5),

   characterized in that
   the detector device (1, 10 - 15) has at least two extensions (A, B) of different magnitude in the transport direction (T).
2. An apparatus according to claim 1, characterized in that the detector device (1, 10 - 15) has a contour with a step-shaped course in at least a partial area of the object (5).
3. An apparatus according to either of claims 1 and 2, characterized in that the detector device (1, 10 - 15) has a contour with a continual course of extension in the transport direction (T) in at least a partial area of the object (5).
4. An apparatus according to claim 3, characterized in that the continually extending contour has a continually decreasing or increasing extension (B) in the transport direction (T).
5. An apparatus according to either of claims 3 and 4, characterized in that the detector device (1, 10 - 15) has

   a polygonal form, in particular the form of a triangle or trapezoid, or

   a round form, in particular the form of a segment of an ellipse or circle.
6. An apparatus according to any of claims 1 to 5, characterized in that the detector device (1, 10 - 15) includes at least two detector units (10-14) disposed one behind the other in the transport direction (T) and having at least two intervals (A) of different magnitude therebetween in the transport direction (T).
7. An apparatus according to claim 6, characterized in that the detector units (10 - 14) each enclose different angles (α) with the transport direction (T).
8. An apparatus according to claim 7, characterized in that at least one detector unit (10) is oriented perpendicular to the transport direction (T), and at least one detector unit (11 - 14) encloses an acute angle (α) with the transport direction (T).
9. An apparatus according to any of claims 1 to 8, characterized in that the detector device (1, 10 - 15) or at least one detector unit (10 - 15) is inclined by an acute angle to a plane of the object (5).
10. An apparatus according to any of claims 6 to 9, characterized in that the interval varies between at least two detector units (10) and the plane of the object (5).
11. An apparatus according to any of claims 1 to 10, characterized in that an evaluation device (3) is provided for determining the position of a feature (30, 40, 50 - 53) on the object (5) and/or the nature, in particular the shape and/or size, of a feature (30, 40, 51 - 54) from the detector signal (S).
12. An apparatus according to claim 11, characterized in that the evaluation device (3) is designed for determining the position or nature, in particular the shape and/or size, of the feature (30, 40, 51 - 54) from the duration (Δt1, Δt2, Δt3) and/or the time interval (Δτ1, Δτ2) of pulses (S1 - S8) of the detector signal (S).
13. An apparatus according to any of claims 1 to 12, characterized in that the evaluation device (3) is designed for performing a Fourier analysis of the detector signal (S).
14. An apparatus according to any of the above claims, characterized in that the detector device (1, 10 - 15) is designed for detecting electric and/or magnetic and/or optical properties of the object (5) and/or a feature (30, 40, 51 - 54) located in or on the object (5).
15. A method for examining objects, in particular documents of value, identification or security documents, wherein

    an object to be examined (5) is guided past a detector device (1, 10 - 15) in a transport direction (T), and

    the detector device (1, 10 - 15) detects at least one property of the object to be examined (5) and generates at least one detector signal (S) corresponding to the detected property,

    characterized in that the object (5) moves relative to at least two extensions (A, B) of different magnitude of the detector device (1, 10 - 15) in the transport direction (T), wherein

    a feature (30, 40, 50 - 54) located on or in the object (5) traverses the detector device (1, 10 - 15) in the area of at least one of the extensions (A, B), and

    a detector signal (S) corresponding to the traversed extension (A, B) is generated.
16. A method according to claim 15, characterized in that the position of the feature (30, 40, 50 - 53) on the object (5) and/or the nature, in particular the shape and/or size, of the feature (30, 40, 51 - 54) is determined from the detector signal (S).
17. A method according to claim 16, characterized in that the position or nature, in particular the shape and/or size, of the feature (30, 40, 51 - 54) is determined from the duration (Δt1, Δt2, Δt3) and/or the time interval (Δτ1, Δτ2) of pulses (S1 - S8) of the detector signal (S).
18. A method according to any of claims 15 to 17, characterized in that a Fourier analysis is performed on the detector signal (S).
19. A method according to any of claims 15 to 18, characterized in that the detector device (1, 10 - 15) detects electric and/or magnetic and/or optical properties of the object (5) and/or the feature (30, 40, 51 - 54) located in or on the object (5).

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