Device and method for detecting anomalies when stacking value documents

Abstract

The invention relates to a device (10) for detecting anomalies when stacking value documents (12) which are stacked to form a value document stack (14) in a stacker region (20) that has a stacker wheel (22) and a stacker compartment (24). A camera unit (30) has a detection region (32) which comprises at least a partial region (34) of the stacker region (20) which is located outside the stacker wheel (22) and outside the value document stack (14) formed in the stacker compartment (24), the camera unit (30) capturing an image (35) which represents an actual state (36) in at least the partial region (34). A processing unit (60) evaluates the image (35) captured by the camera unit (30), the evaluation comprising detecting whether the actual state (36) of the partial region (34) deviates from a target state (37) of the partial region (34). The processing unit (60) generates output information based on the evaluation.

Description

[0001] Apparatus and method for detecting anomalies in stacking valuable documents

[0002] Field of the invention

[0003] The present invention relates to the monitoring of value document processing operations. In particular, the invention relates to a device for detecting anomalies during the stacking of value documents and a method for detecting anomalies during the stacking of value documents.

[0004] Background of the invention

[0005] Security document processing devices are used to check, sort, and stack valuable documents, such as banknotes. The valuable documents are first separated to enable checking and, if necessary, sorting of the individual valuable documents. The individual valuable documents are then stacked by a stacker device of the security document processing device to make them available in stacked form. The valuable documents can be stacked in a stacker compartment to form a stack of valuable documents.

[0006] Typically, the valuable documents to be stacked, which are stripped from a stacker wheel using a stripper, for example, fall from the stacker wheel down onto a stack holder located beneath the stacker wheel or onto the stack of valuable documents located there. However, it can happen that the valuable documents end up next to the stack or next to the stacker wheel and possibly remain upright or get stuck there instead of being placed on the stack. This can lead to disruptions, for example if these valuable documents hinder further stacking, and to accounting errors, as these valuable documents may then not end up on the intended stack. If such disruptions are only detected when the completed stack of valuable documents is removed, for example by an operator or a gripper, the disruption or the problem must be rectified.The billing error involves greater effort than if the fault were detected at an early stage.

[0007] Description

[0008] It can be considered an object of the present invention to facilitate the elimination of faults in the stacking of value documents.

[0009] This object is achieved by the subject matter of the independent claims. Exemplary embodiments emerge from the dependent claims and the following description.

[0010] According to one aspect, a device is provided for detecting anomalies during the stacking of value documents that are stacked to form a value document stack during automatic value document processing in a stacker area having a stacker wheel and a stacker compartment. The device comprises a camera unit with a detection area that encompasses at least a partial area of ​​the stacker area that is located outside the stacker wheel and outside the value document stack, in particular formed in the stacker compartment. The camera unit is designed to capture an image that represents an actual state in at least the partial area outside the stacker wheel and the value document stack.The device further comprises a processing unit which is designed to evaluate the image captured by the camera unit, wherein the captured image is used to detect whether the actual state of the sub-area deviates from a target state of the sub-area. The processing unit is further designed to generate output information based on the evaluation. In particular, the processing unit is designed to generate the output information based on whether the actual state of the sub-area deviates from a target state of the sub-area. If a deviation of the actual state from the target state of the sub-area is determined during the evaluation, output information, in particular a control signal for stopping the processing of the value document orto warn the operator, and otherwise, if no deviation of the actual state from the target state of the sub-area is detected, this output information or control signal is not output.

[0011] The processing unit is preferably also designed to use the captured image to detect how much the actual state of the sub-area deviates from a target state of the sub-area. In particular, the processing unit is also designed to generate the output information based on how much the actual state of the sub-area deviates from a target state of the sub-area, e.g., taking into account a threshold with which the deviation is compared. For example, the output information can be generated depending on whether the deviation exceeds the threshold (in which case a control signal is generated to stop the processing of the value document or to warn the operator) or not (in which case no control signal is generated to stop the processing of the value document or no control signal is generated to warn the operator).

[0012] The device according to the invention makes it possible to better monitor a value document stacking process during value document processing and to react more quickly to malfunctions. In particular, the device according to the invention allows for direct evaluation of a status within the stacker area in order to reliably and quickly detect any anomalies that may occur during value document processing. This means that corresponding countermeasures or control measures can then be initiated to eliminate these anomalies. For example, an operator can be alerted to such anomalies at an early stage using the device according to the invention, so that they can stop the automatic value document processing or at least the value document stacking process in the stacker area affected by the malfunction in good time. In a further example, the value document stacking process can be autonomous orcan be stopped automatically and thus independently of the operator, which can be accomplished through appropriate control steps of the automatic value document processing. The device according to the invention can essentially be used to detect value documents that have deviated from their prescribed or predetermined movement path in the stacker area and could thus lead to disruptions in the further process of value document processing. The device is advantageously used in value document processing devices in which the view of the stacker area for an external operator is obscured by housing panels or covers during operation.

[0013] During a stacking process, the valuable documents, such as banknotes, are stacked into a stack of valuable documents in a stacking area containing the stacking wheel and the stacking compartment. During stacking using the stacking wheel, the individual valuable documents are inserted into the stacking wheel one after the other at short intervals, which then transports them to the stacking compartment by rotating the wheel. The valuable documents can then be removed one after the other from the stacking wheel by means of a stripper, thereby being stacked in the stacking compartment.

[0014] An anomaly or deviation during the stacking of valuable documents can be characterized, for example, by a valuable document deviating from a predetermined movement path and thus no longer being properly stacked on the valuable document stack in the stacker compartment. A valuable document that deviates from the predetermined movement path can, for example, end up in areas away from the stacker wheel or the valuable document stack, or even impair or block the further stacking of subsequent valuable documents onto the valuable document stack.

[0015] To prevent this, an image-based recording of an actual state within parts of the stacker area that are located outside the stacker wheel and the stack of valuable documents is described herein. The camera unit mentioned above is aligned or oriented with respect to the stacker area in such a way that it covers a recording area in which processes within the stacker area can be recorded. The camera unit can be designed to record only the image to be evaluated in the recording area. However, it can also be provided that the camera unit records an overall image of its recording area and only one or more partial images of the recorded overall image are evaluated, so that the respective recorded image to be evaluated during the evaluation is a partial image of the recorded overall image.

[0016] The captured image to be evaluated during the analysis can correspond to one or more regions of interest (ROIs) that, as seen from the camera, lie outside the stacker wheel and also outside the stack of valuable documents. These can represent sub-areas away from the stacker wheel or the stack of valuable documents into which valuable documents typically or are expected to end up when they deviate from the specified movement path. This means that the sub-areas are located where valuable documents are suspected of leaving their intended paths, for example, next to the stacker wheel, next to the stack of valuable documents, etc.Likewise, a sub-area may be located where valuable documents were inadvertently left in the stacker compartment, for example on a storage plate, whereby an analysis of this sub-area is preferably only carried out when the stack of valuable documents has been removed from the stacker compartment and the sub-area thus represents an area outside the stack of valuable documents.

[0017] In one example, the device according to the invention further comprises a fastening unit which is designed to fasten the device within a value document processing device such that the detection range of the camera unit of the device is aligned with the stacker area. The camera unit can thus be attached, for example, to a housing section or within a housing section of the value document processing device, wherein the housing section at least partially surrounds a stacker area in which the stacker wheel and the stacker compartment are arranged, or shields it from an external environment. The camera unit can thus capture a stacker area or a section thereof from the front, i.e. from an operator side, wherein the stacker wheel and the value document stack may or may not be included in the captured image.For this purpose, the camera unit can be mounted directly behind a cover of the stacker area, for example, as seen from the operator side. Alternatively, the camera can also be located opposite, i.e., as seen from the operator side, behind the stacker wheel in the security document processing device and directed from the inside toward the stacker wheel and the stacker cover.

[0018] Preferably, however, the image evaluated during the evaluation is selected such that it only shows one or more sub-areas of the stacker area that are located outside the stacker wheel and outside the stack of valuable documents (in particular formed in the stacker compartment). In particular, neither the (rotating) stacker wheel or parts thereof nor the (currently growing) stack of valuable documents or parts thereof are shown in the evaluated image. This has the advantage that areas are not evaluated in which, during a trouble-free stacking process, a movement of the valuable document and thus an image change occurs or is expected. The evaluation is specifically carried out only in those areas where, during a trouble-free stacking process, no movement of the valuable document or image change occurs or is expected. The evaluation can therefore more easily distinguish image changes that indicate a fault from regular movement of the valuable document orthe resulting image changes. This avoids a false alarm that might occur due to regular valuable document movements.

[0019] The camera unit may comprise one or more cameras, which may be arranged relative to the individual components of the value document processing device as previously explained. The optical axis of the camera unit or the camera may be aligned substantially parallel to the stacker wheel axis or slightly inclined to it in order to capture images of the stacker area.

[0020] The image captured by the camera unit, which depicts one or more areas outside the stacker wheel and the stack of valuable documents, is evaluated by the processing unit following capture. The image can be a selected section of the overall image captured by the camera unit. Analogously, several images can also be selected for evaluation. The image to be evaluated can be specified in advance or during the evaluation. In particular, a position of the image to be evaluated within the captured overall image as well as a width and height of the image can be specified. The captured image represents in particular an actual state, i.e. a current state, of the stacker area, as it appears within the stacker area at a current time during image capture.Thus, the partial area shown in the image also represents an actual state, i.e. a current state, for an area outside the stacker wheel and the stack of valuable documents.

[0021] It is possible to define a multitude of images in a single overall image captured by the camera unit, whereby only these are evaluated by the processing unit. An evaluation can be carried out on the basis of one or more captured images together with one or more reference images, whereby individual or different image analysis techniques or evaluation algorithms can be used for each image or images. Three variants of evaluation algorithms can be used for this purpose. The first evaluation algorithm can be based on a comparison of the captured image with a reference image, whereby the reference image can be created by recording an undisturbed starting situation.The second evaluation algorithm can be based on a comparison of a currently recorded situation in the sub-area with a (immediately) previously recorded situation in the sub-area during operation. The comparison can be made between two consecutive images of an image sequence. The third evaluation algorithm can be based on an evaluation of edge information in two consecutive images or on a comparison with edge information in the reference image. These evaluation algorithms will be explained in more detail below.

[0022] To perform the evaluation and detect an anomaly or deviation from a proper transport process with subsequent stacking of valuable documents, the processing unit can now perform a kind of comparison of the actual state of the sub-area located outside the stacker wheel and outside the valuable document stack depicted in the image with a target state of this sub-area. The target state of the sub-area can be a reference state of the sub-area, which represents a state of the sub-area—i.e., a state outside the stacker wheel and outside the valuable document stack—as it would occur during a proper stacking process.

[0023] For example, during a proper stacking process, no valuable document would deviate from the specified movement path and enter areas outside the stacker wheel and the valuable document stack. The target state of the sub-area can thus be characterized by the absence or non-presence of valuable documents in the sub-area.

[0024] If a valuable document now reaches the sub-area located outside the stacker wheel and outside the stack of valuable documents, the actual state of which is shown in the captured image, there is a deviation between the actual state and the target state for that sub-area. In other words, the processing unit can detect a deviation that indicates that a valuable document is present within the sub-area or that a valuable document has deviated from the specified movement path. To do this, the processing unit can compare image data from the captured image representing the actual state with image data from the reference image representing the target state. The processing unit can use various image analysis techniques for evaluation. An individual algorithm can be defined for each captured image or ROI.

[0025] The processing unit can then generate output information based on the evaluation, which can be provided as an output signal perceivable by an operator or as a control signal for a value document processing device. It can be provided that the output information is only generated if a deviation was detected during the evaluation by the processing unit. In addition to an image evaluation device, the processing unit can also have a control device, wherein the image evaluation device can be designed to carry out the evaluation described above, and the control device can be designed to provide the control signal for the value document processing device. The processing unit can have a computing device or a computer device, for example in the form of a processor.

[0026] The device can further comprise a light source, which is directed, for example, from the camera side onto the stacker area to be scanned, in order to illuminate it for image capture. The illumination is preferably not pulsed, but is switched on continuously during the stacking of the valuable documents or during the capture of the images by the camera unit.

[0027] According to one embodiment, the processing unit is designed to detect, on the basis of the captured image, a deviation between the actual state of the sub-area and the target state of the sub-area, which allows the conclusion that a value document is present within the sub-area.

[0028] According to one embodiment, the camera unit is designed to capture and evaluate an image sequence comprising a plurality of captured images using an image capture rate, wherein the image capture rate corresponds, for example, to a predetermined value document processing rate or an integer divisor of the value document processing rate at which the value documents are transported to the stacker area during automatic value document processing. The image sequence can comprise a plurality of consecutive images, wherein all images each comprise the selected sub-area. The images of the image sequence represent the same sub-area located outside the stacker wheel and outside the value document stack.

[0029] Preferably, the images of the image sequence are evaluated individually. The camera unit is designed, for example, to evaluate several images of the image sequence, e.g., each individual image, to determine whether this image detects a deviation between the actual state of the sub-area and the target state of the sub-area, which would indicate that a valuable document is present within the sub-area. Alternatively, several consecutively captured images can be combined and evaluated.

[0030] The value document processing rate can, for example, define a rate or cadence at which the individual value documents are fed to the stacker wheel one after the other. This allows the captured images of the stacker area to be captured in sync with the value documents being transported to the stacker wheel.

[0031] It can be provided that for each value document that is transported to the stacker area (20), exactly one image is captured by the camera unit, which is then evaluated by the processing unit as described above. The capture of the respective image can be triggered, for example, by the arrival of the respective value document in the stacker area or at the stacker wheel, or by the separation of the value documents from a stack or by transport to the stacker area of ​​the value documents. Since monitoring can thus take place in time with the processing of the value documents, it is possible to stop the value document processing device in a timely manner. This makes it possible to restore the sequence of the value documents and thus the allocation of the value documents to various deposits.

[0032] According to one embodiment, the target state of the partial area is predetermined by a reference image representing the partial area in the target state, wherein the evaluation comprises the detection of a deviation between the captured image representing the partial area in the actual state and the reference image.

[0033] It can be provided to create an initial image as a reference image, which is then always used as the basis for evaluation in the processing unit. The reference image includes, in particular, the partial area outside the stacker wheel and the stacker compartment in the target state, as it would appear during a proper stacking process. For example, during a proper stacking process, no valuable document would deviate from the specified movement path and end up in the partial area outside the stacker wheel and the valuable document stack. The target state of the partial area can thus be characterized by the absence or non-presence of valuable documents in the partial area. The actual state of the partial area, on the other hand, is represented by the same partial area as it appears in the currently captured image.

[0034] The reference image can form the starting point for the evaluation and be compared with all (subsequent) images captured by the camera unit. In particular, the camera unit can capture several consecutive images according to the specified image capture rate explained above. Each of these captured images can be immediately compared with the reference image after capture. This allows an absolute difference, for example, an intensity or color difference, between the sub-area in the respective captured image and the corresponding sub-area in the reference image to be determined.

[0035] It can be provided that for the evaluation only image data or pixel data in the captured image and the reference image are compared with each other in order to detect any deviations between them.

[0036] According to one embodiment, the camera unit is designed to capture an image sequence, wherein the image sequence comprises at least a first image with the partial area (representing the partial area) and a second image with the partial area (representing the same partial area) captured chronologically after the first image, and wherein the evaluation comprises detecting a deviation between the first image and the second image. The first image is captured, for example, at the beginning of the image sequence or immediately before the second image. The first image is used, in particular, as the reference image representing the partial area in the target state, and the second image is used as the captured image representing the partial area in the actual state. It can be provided, for example, that the image with the partial area captured immediately beforehand is always used as the reference image, which represents the target state of the partial area.The currently acquired image is used to determine the actual state of the sub-area. The evaluation can be carried out by detecting a deviation between image data in the second image and image data in the previously acquired, first image. In this case, a relative difference, for example an intensity or color difference, between the successively acquired images of an image sequence can be determined. As explained above, the images of the image sequence can be acquired at an acquisition rate that corresponds to the value document processing rate or to an integer divisor k (with k> 1) of the value document processing rate. In the first case, an image is acquired for each value document processed, in the second case only for each kth value document processed, where, for example, k can take the values ​​2, 3, 4, 5, ....

[0037] According to one embodiment, the evaluation may include edge detection in the captured image and in the reference image, wherein the evaluation particularly comprises detecting a deviation between the edges detected in the captured image and the edges detected in the reference image. Edge data in the currently captured image (actual state of the partial area) may be compared with edge data in the reference image (desired state).

[0038] The reference image can, in turn, be an initial image of a quasi-ideal state of the partial area outside the stacker wheel and the stack of valuable documents, in which no valuable document comes to rest outside the specified movement path. Likewise, the reference image can, in turn, be a previously acquired first image, whereby a deviation between edge data in the subsequently acquired second image and edge data in the previously acquired first image can be compared. Edge detection can involve the application of a Canny algorithm.

[0039] The output information can be generated depending on the deviation between the edges detected in the captured image and the edges detected in the reference image. For example, a deviation between the number of pixels identified as belonging to an edge in the captured image and the number of pixels identified as belonging to an edge in the reference image is used as the deviation between the edges detected in the captured image and the edges detected in the reference image.

[0040] In one example, the evaluation may include color detection in the captured image, wherein colors of areas in the captured image may be compared with colors of areas in the reference image.

[0041] According to one embodiment, the target state is represented by the reference image depicting the partial area in the target state, and the actual state of the partial area is represented by pixel data of the captured image. The evaluation includes detecting a discrepancy between the pixel data of the reference image and the pixel data of the captured image. The output information can then be generated depending on the discrepancy between the pixel data of the reference image and the pixel data of the captured image.

[0042] In other words, the evaluation in the processing unit can be performed by analyzing pixel data in the captured image. For this purpose, a corresponding algorithm can be used that analyzes the intensity of pixels in the captured image. It can be provided that the target state of the partial area is represented by pixel data within the reference image, which represents the partial area outside the stacker wheel and the stack of valuable documents. Similarly, it can be provided that the actual state of the partial area is represented by pixel data within the captured image, which represents the partial area outside the stacker wheel and the stack of valuable documents. The evaluation can then include detecting a discrepancy between the pixel data of the reference image and the pixel data of the captured image.

[0043] According to one embodiment, detecting the deviation between the pixel data of the reference image and the pixel data of the captured image comprises determining an intensity difference between pixels of the reference image and respective corresponding pixels of the captured image, wherein the evaluation further comprises determining whether the determined intensity difference between the pixels of the reference image and the pixels of the captured image exceeds a threshold intensity difference. The output information can then be generated depending on whether or not the determined intensity difference between the pixels of the reference image and the pixels of the captured image exceeds a threshold intensity difference.

[0044] According to one embodiment, the evaluation further comprises determining whether the determined intensity difference exceeds the threshold intensity difference for a minimum number of pixels. The output information can then be generated depending on whether or not the determined intensity difference exceeds the threshold intensity difference for a minimum number of pixels. In particular, the output information is generated only if the determined intensity difference exceeds the threshold intensity difference for a minimum number of pixels and not otherwise.

[0045] In other words, a number of conspicuous pixels in each acquired image can be determined, wherein a pixel is classified as conspicuous if, for that pixel, the threshold intensity difference between the acquired image and the reference image is exceeded. In another example, it can be determined whether, for a pixel, the threshold intensity difference relative to the reference image is exceeded for a minimum number of consecutively acquired images.

[0046] For each captured image, an individual threshold intensity difference can be provided which must be exceeded in order for an anomaly to be detected during evaluation. In other words, a threshold value can be set which, if exceeded, triggers the stoppage of value document processing. By specifying a threshold value for the intensity difference, small changes in the comparison algorithm can be permitted, for example shadows from movements of the stacker wheel and value documents, without immediately detecting an anomaly. According to one embodiment, the output information corresponds to an output signal for an operator. This can represent a warning to the operator of a malfunction in the stacker area. Additionally or alternatively, the output information corresponds to a control signal for the automatic value document processing orfor the value document processing device, which can in particular cause the automatic value document processing to be stopped.

[0047] The output information may include an output signal perceptible to an operator of the value document processing device. For example, the output information may include an acoustic, optical, or haptic signal.

[0048] For example, a value-document processing device in which the device according to the invention is integrated can output an error message or an alarm signal, for example a "CAN message," to the operator or to automatically stop further separation of value documents. Automatic stopping is particularly advantageous in a stacker module in which the operator's view of the stacker area is obscured by an opaque cover of the stacker area during operation of the value-document processing device.

[0049] Furthermore, the output information may comprise a control signal which is configured to provide corresponding control commands to the value document processing device, into which the device according to the invention may be integrated, so that the value document processing device, on the basis of these control commands, for example, causes the value document processing to be automatically stopped.

[0050] According to one embodiment, the partial area outside the stacker wheel and the valuable document stack comprises an area, for example a region of interest (ROI), between the valuable document stack and a side wall of the stacker compartment. The side wall can represent a lateral boundary of the stacker compartment, which extends in a vertical direction with respect to the stacker area or with respect to a valuable document processing device comprising the device according to the invention. The partial area outside the stacker wheel and the valuable document stack can thus be formed by an intermediate space that is located at least partially between the side wall of the stacker compartment and the valuable document stack formed in the stacker compartment.

[0051] Alternatively or additionally, the partial area outside the stacker wheel and the stack of valuable documents comprises an area adjacent to an outer circumference of the stacker wheel and extending within a housing of the stacker area, which area represents, for example, a further region of interest (ROI).

[0052] This further region can extend outside an outermost circumference of the stacker wheel and thus, for example, be located adjacent to an outer periphery of the stacker wheel. The housing can comprise a housing wall that extends at least partially circumferentially around the stacker wheel and is arranged at a radial distance from the outer circumference of the stacker wheel. The partial region outside the stacker wheel and the stack of valuable documents can thus represent an intermediate space that extends at least partially between the side wall and the outer circumference of the stacker wheel.

[0053] Alternatively or additionally, the partial area outside the stacker wheel and the stack of valuable documents includes an area encompassing the stacker compartment, particularly if there is no stack of valuable documents in the stacker compartment. This can, for example, represent another region of interest (ROI).

[0054] It can be provided that this partial area encompassing the stacker compartment represents an area where valuable documents are normally stacked, but the image of this partial area is only captured when there is no longer a valuable document stack in the stacker compartment, for example, after the valuable document stack has been removed from the stacker compartment. Thus, the image with the stacking compartment used for evaluation by the processing unit is also an image that represents a partial area outside the stacker wheel and outside the valuable document stack (which is no longer present in the stacking compartment at the time of image capture).

[0055] As explained above, the sub-area can represent or depict various areas of the stacker area outside the stacker wheel and outside the stack of valuable documents. It is possible for a large number of images to be evaluated by the processing unit. An evaluation can therefore be performed based on multiple images that can represent various of the exemplary sub-areas explained above.

[0056] The device according to the invention can be designed in the form of a module, e.g., a retrofit module, for an existing value document processing device, which module can be integrated into an existing value document processing device or can be attached and secured to an existing value document processing device. The module can, e.g., be integrated into a stacker module of an existing value document processing device or can be secured thereto in order to monitor its stacking area in the manner according to the invention. The stacker module can, e.g., be a reject module of the existing value document processing device, which is used for stacking sorted value documents.

[0057] According to one aspect, a value document processing device for automatically processing value documents is specified, which comprises the device described herein for detecting anomalies when stacking value documents. The value document processing device has a stacker area with a stacker wheel and a stacker compartment for stacking value documents, wherein the stacker area, the stacker wheel, and the stacker compartment can be the components already described above with regard to the device according to the invention. The value document processing device can also have a separating device for separating the value documents from an input stack that is fed to the value document processing device and / or a transport device for transporting the (separated) value documents one after the other to the stacker area, optionally further stacker modules and / or one or more sensors for checking the value documents, e.g.on their authenticity, type or condition.

[0058] In particular, the value document processing device according to the invention can also be designed in the form of an additional module for an existing value document processing device, e.g., in the form of an output module or stacker module of a value document processing device, wherein the camera unit, the processing unit, and the stacker area with the stacker wheel and the stacker compartment are parts of the additional module, and the existing value document processing device can comprise a separating device, a transport device, a checking device, and optionally additional stacker modules. The additional module can be integrated into an existing value document processing device as a separate module assembly, or can be attached and secured to an existing value document processing device.The additional module may comprise corresponding input and output interfaces designed to connect to associated interfaces of the value document processing device.

[0059] The value document processing device can comprise a fastening option for fastening the device according to the invention within or on the value document processing device. The stacker wheel and the stacker compartment can be arranged in a housing of the value document processing device. In one example, the value document processing device has an opaque housing, so that an operator's view of the stacker area, including the stacker wheel, stacker compartment, and spaces within the housing, is blocked from the outside. The camera unit can be arranged and / or fastened directly behind a housing section of the housing, as seen from the operator. According to one aspect, a method is specified for detecting anomalies during the stacking of value documents that are stacked into a value document stack during the automatic processing of the value documents in a stacker area having a stacker wheel and a stacker compartment.In one step, an image is captured by a camera unit such that the captured image represents an actual state in at least one partial area of ​​a capture range of the camera unit, wherein the partial area is located outside the stacker wheel and the stack of valuable documents, in particular formed in the stacker compartment. In a further step, the captured image is evaluated by a processing unit, wherein during the evaluation, it is recognized on the basis of the captured image whether the actual state of the partial area deviates from a target state of the partial area. In a further step, output information is generated by the processing unit based on the evaluation. The method steps can be carried out in the stated order.

[0060] The method according to the invention can thus be used to detect, based on camera images, whether a valuable document is located in an area outside the stacker wheel and outside the deposited valuable document stack, or possibly even several. Exactly one image can be captured for each valuable document transported to the stacker area. This means that the image capture rate of the camera unit can correspond to the valuable document processing rate, for example, a feed rate of the valuable documents fed into the stacker wheel. These captured images can then each be evaluated with regard to anomalies, as described above with regard to the device according to the invention. In particular, it is provided that one or more partial areas are shown in the respective captured image that lie completely or almost completely outside the stacker wheel or below or next to the stacker wheel.Preferred sub-areas are also located completely or almost completely outside the stack of valuable documents itself. According to the invention, in particular, it is not the stacker wheel or the stack of valuable documents itself that is to be monitored, but only the sub-areas outside the stacker wheel and the stack of valuable documents.

[0061] Brief description of the figures Fig. 1 shows a device for detecting anomalies when stacking value documents which are stacked to form a value document stack in a stacking area having a stacking wheel and a stacking compartment.

[0062] Fig. 2 shows a section of the device from Fig. 1 including exemplary sub-areas for determining anomalies when stacking value documents.

[0063] Fig. 3 A shows the overall image captured by the camera unit, which represents a target state of an exemplary partial area for determining anomalies when stacking value documents.

[0064] Fig. 3B shows a section of the overall image from Fig. 3 A, which is used as a reference image.

[0065] Fig. 4A shows the overall image captured by the camera unit, which represents an actual state of an exemplary partial area for determining anomalies when stacking value documents.

[0066] Fig. 4B shows a section of the overall image from Fig. 4A which is evaluated as a captured image.

[0067] Fig. 5 shows a first example process for determining anomalies when stacking value documents.

[0068] Fig. 6 shows a second example process for determining anomalies when stacking value documents.

[0069] Fig. 7 shows a third example process for determining anomalies in the stacking of value documents. Fig. 8 shows a block diagram of individual steps performed in a device for detecting anomalies in the stacking of value documents, including interfaces of the device to a value document processing device.

[0070] Fig. 9 shows a flowchart for a method for detecting anomalies when stacking value documents.

[0071] Detailed description of exemplary embodiments

[0072] The representations in the figures are schematic and not to scale. Where the same reference symbols are used in different figures in the following description, they refer to identical or similar elements. Identical or similar elements may also be designated by different reference symbols.

[0073] Fig. 1 shows a device 10 for detecting anomalies during the stacking of value documents 12, which are stacked into a value document stack 14 in a stacking area 20 having a stacker wheel 22 and a stacker compartment 24. Fig. 1 also shows a section of a value document processing device 100, which may include the device 10 for detecting anomalies during the stacking of value documents 12. For the sake of simplicity, the device 10 for detecting anomalies during the stacking of value documents 12 is also referred to herein simply as device 10.

[0074] The device 10 has a camera unit 30 with a detection area 32, which comprises at least a partial area 34 of the stacker area 20 located outside the stacker wheel 22 and outside the valuable document stack 14 formed in the stacker compartment 24. The stacker area 20 can comprise the stacker wheel 22, the stacker compartment 24, and various intermediate or free spaces of the stacker area 20 formed by a housing 28. The valuable documents 12 can be fed individually and successively to the stacker wheel 22 via a feed unit, for example, via a belt transport device. The valuable documents 12 are then fed into the stacker wheel 22, for example, by being inserted into intermediate spaces in the stacker wheel 22 formed by stacker wheel fingers 23 distributed along the circumference of the stacker wheel 22. The stacker wheel 22 can be mounted so as to rotate relative to a rotation axis 21.A stripper 26 removes the valuable documents 12 one after the other from the gaps of the stacker wheel 22 during the rotation of the stacker wheel 22, whereby they are transported into the stacker compartment 24, where they are stacked one after the other to form the valuable document stack 14. The stacker compartment 24 can be container-shaped, as shown in Fig. 1. The formed valuable document stack can then be removed from the stacker compartment manually or by a gripper.

[0075] The camera unit 30 is designed to capture an image representing an actual state in at least the partial area 34 outside the stacker wheel 22 and outside the valuable document stack 14. In Fig. 1, the partial area 34 is an area 34a, also referred to herein as the region of interest or ROI for short, which extends into the stacker compartment 24 but does not include the valuable document stack itself. This area 34a is indicated in Fig. 1 by a dashed line. It can be seen that the area 34a is arranged between a side wall 29 of the stacker compartment 24 and the valuable document stack 14 and thus represents a partial area 34 outside the stacker wheel 22 and the valuable document stack 14. For better understanding, the walls of the stacker compartment 24 are shown transparent. Although the camera unit is shown only in the form of a single camera in Fig. 1, it should be understood that the camera unit can comprise multiple cameras.

[0076] The device further comprises a processing unit 60, which is designed to evaluate the image captured by the camera unit 30, wherein the evaluation comprises detecting whether and, if so, to what extent the actual state of the partial area 34, 34a deviates from a desired state of the partial area 34, 34a. This means that the processing unit 60, which can be embodied in the form of a computing device or a processor, processes the image data captured by the camera unit 30, which define the actual state at least in the partial area 34, 34a, by comparing it with reference image data, which define the desired state in the partial area 34, 34a. Various image analysis techniques or image analysis processes can be used, as will be explained in more detail with reference to Figures 5 to 7. The processing unit 60 can comprise an evaluation device 61, which carries out the processing or evaluation described herein.

[0077] The processing unit 60 is further configured to generate output information based on the processing or evaluation. For this purpose, the processing unit 60 may also have a control device 62 in addition to the evaluation device 61. The evaluation device 61 may be configured to perform the evaluation described herein based on the image representing the partial area 34, 34a in the actual state and based on the reference image representing the partial area 34, 34a in the desired state. The control device 62 may be configured to provide a control signal for the value-document processing device 100, in particular for a control device 70 of the value-document processing device 100. For this purpose, the processing unit 60 may have a corresponding interface configured for communicative coupling with the control device 70 of the value-document processing device 100.The processing unit 60, in particular the control device 62 of the processing unit 60, can additionally or alternatively output an output signal to an operator of the value-document processing device 100, e.g., on the display of the value-document processing device 100. For this purpose, the processing unit 60 can send a corresponding signal to the control device 70 of the value-document processing device 100, or have another corresponding interface configured for communicatively coupling with a user interface 80, e.g., a display, of the value-document processing device 100. The control device 62 of the processing unit 60 can also be designed to specify an image capture rate or image capture clock rate at which the camera unit 30 performs the image capture described herein.The camera unit 30 captures the images, for example, triggered by the value documents 12 transported to the stacker wheel 22. For example, the images can be captured synchronously with a singulation or a singulation cycle of the value documents 12 or synchronously with a machine cycle of a transport system of the value document processing device 100. Furthermore, the images can be captured triggered by a signal from a detection unit 50 that is arranged on a transport path leading to the stacker wheel 22. Such a detection unit 50 on the transport path leading to the stacker wheel 22 can be a light barrier. The detection unit 50 can detect the passing of value documents 12 before entering the stacker wheel 22 and, each time a value document 12 passes, send a trigger signal to the processing unit 60, the control device 62 of which then sends an image capture command based on the received trigger signal.Sends a trigger signal to the camera unit 30. The image capture frequency or image capture rate preferably corresponds to the value document processing rate, for example, the singulation cycle or the machine cycle of the value document processing device 100. It is, for example, between 5 / s (five value documents per second) and 50 / s (fifty value documents per second). In one example, the value document processing rate is 33 / s (thirty-three value documents per second).

[0078] The capture unit 50 can be a subcomponent of the value document processing device 100, wherein the trigger signal originating from the capture unit 50 is sent via an interface between the value document processing device 100 and the device 10 to the control device 62 of the processing unit 60, so that the camera unit 30 subsequently initiates the corresponding image capture based on the trigger signal. After evaluation by the evaluation device 61, the generated output signal can be returned to the value document processing device 100 via the same or another interface between the value document processing device 100 and the device 10 in order to trigger a processing stop, in particular a singulation stop, or to alert the operator of the value document processing device 100 that an anomaly has occurred.

[0079] The device 10 can further comprise a light source 40, which is directed, for example, from the camera unit 30 onto the stacker area to be captured, i.e., onto the capture area 32, in order to illuminate it for image capture. The illumination can be continuously switched on. Alternatively, the light source 40 can also be a subcomponent of the value document processing device 100 instead of being a subcomponent of the device 10. With appropriate external illumination of the stacker area 20, the device 10 may not require its own light source.

[0080] The device 10 can be designed in the form of an assembly, e.g., a retrofit assembly, for the existing value document processing device 100, which has been integrated into the existing value document processing device 100 and which comprises the camera unit 30 and the processing unit 60. Optionally, the device 10 can also have the light source 40 in addition to the camera unit 30 and the processing unit 60. The device 10 according to the invention can be designed as an optional assembly for a value document processing device 100, which can be attached thereto. The assembly representing the device 10 according to the invention can contain corresponding input and output interfaces, which are configured for wired or wireless coupling with corresponding interfaces of the value document processing device 100.

[0081] Fig. 2 shows a section 35 of the device 10 from Fig. 1, including exemplary subregions 34, 34a, 34b, 34c for determining anomalies when stacking value documents 12. The exemplary subregions 34, 34a, 34b, 34c are represented by dashed lines in Fig. 2. The stacker wheel 22, the stripper 26, and the stacker compartment 24 are shown in Fig. 2 in a side view, although reference is also made to Fig. 1 for better understanding. The subregion 34a, or at least a similar subregion 34a, has already been explained in more detail with reference to Fig. 1. The partial area 34a defines an area 34a within the stacker compartment 24 adjacent to the side wall 29 of the stacker compartment 24. Preferably, the partial area 34a lies completely outside the valuable document stack 14. Images of further partial areas can also be evaluated, as can be seen in Fig. 2.For example, an upright value document 12 may be located in the partial area 34a, which has mistakenly ended up next to the value document stack 14.

[0082] The sub-area 34 can, for example, also be represented by a sub-area 34b comprising the stacker compartment 24, in which sub-area 34b the value documents 12 are normally stacked to form the value document stack 14. In particular, it can be provided that this sub-area 34b comprising the stacker compartment 24 represents a sub-area 34b where the value documents 12 are otherwise stacked, but the image capture for evaluating this sub-area 34b takes place at one or more such points in time at which the value document stack 14 is no longer present in the stacker compartment 24, for example after each removal of the value document stack 14 from the stacker compartment 24 and / or as soon as the respective stack has reached the maximum number of value documents (e.g. 500).Thus, the partial area 34b, which is used for evaluation by the processing unit 60, is also to be regarded as a partial area 34b outside the stacker wheel 22 and also outside the value document stack 14.

[0083] The partial area 34 outside the stacker wheel 22 and the value document stack 14 can also represent a partial area 34c outside the housing 28 of the stacker area 20, in particular a partial area 34c that is located directly on a wall of the housing 28, but outside the housing 28 of the stacker area 20 and / or the side wall 29 of the stacker compartment (see also Fig. 1).

[0084] Fig. 3 A shows the overall image of the

[0085] Detection area 32, which represents a target state 37 of an exemplary sub-area 34 for determining anomalies when stacking value documents 12. The sub-area 34 lies outside the stacker wheel 22 and the value document stack 14 (not present here) and represents a sub-area 34d adjacent to an outer circumference of the stacker wheel 22 and extending within a housing 28 of the stacker area 20. A section of the captured overall image is selected and used as a reference image 38, see Fig. 3B. Fig. 3B shows the reference image 38, which represents the target state 37 of the exemplary sub-area 34, 34d, which can be used for evaluation by the processing unit 60.

[0086] The reference image 38 is, for example, selected in advance and stored in the processing unit 60 as a reference. In addition, a Gaussian smoothing can be performed on the image 35 using a Gaussian filter. The target state 37 of the partial area 34, 34d represents a reference state of the partial area 34, 34d, which represents a state of the partial area 34, 34d, i.e., a state outside the stacker wheel 22 and outside the value document stack 14, as would occur during a proper stacking process. During a proper stacking process, no value document 12 deviates from its predetermined movement path, and the processed value documents 12, in particular, do not reach the partial area shown in Fig. 3A.

[0087] 34, 34d outside the stacker wheel 22 and the stack of valuable documents 14. The desired state 37 of the partial area 34, 34d is thus characterized by an absence or non-presence of valuable documents 12 in this partial area 34, 34d.

[0088] Fig. 4A shows the overall image of the detection area 32 captured by the camera unit (rotated by 90°), which represents an actual state 36 of the exemplary partial area 34 for determining anomalies when stacking valuable documents 12. The partial area 34 outside the stacker wheel 22 and the valuable document stack 14 (not present here) represents, within the captured overall image, the partial area 34d adjacent to the outer circumference of the stacker wheel 22 and extending within the housing 28 of the stacker area 20. A section of the captured overall image is selected and used as the captured image 35, see Fig. 4B. Fig. 4B shows the captured image.

[0089] 35, which can be used for evaluation by the processing unit 60. The captured image 35 therefore corresponds to the reference image 38, with the difference that in the captured image 35 a value document 12 is recognizable in the partial area 34, 34d and not in the reference image 38. The captured image 35 is selected by the processing unit 60, e.g., cut out of the overall image from Fig. 4A, before the captured image 35 is evaluated. In this case, Gaussian smoothing can again be additionally carried out using a Gaussian filter. The actual state 36 of the partial area 34, 34d represents a current state of the partial area 34, 34d, which represents a state of the partial area 34, 34d, i.e., a state outside the stacker wheel 22 and outside the value document stack 14, as it currently occurs within the stacker area 20.As can be seen, a value document 12 has deviated from the movement path and entered the area outside the stacker wheel 22 and the outside value document stack 14.

[0090] During the evaluation by the processing unit 60, the captured image 35 can now be evaluated by comparing it with the reference image 38. During the evaluation, it is determined whether and, if so, to what extent the actual state 36 of the partial area 34, 34d from the captured image 35 (see Fig. 4B) deviates from the desired state 37 of the partial area 34 from the reference image 38 (see Fig. 3B). This is the case when considering Figures 3B and 4B, so that the evaluation by the processing unit 60 detects an anomaly and subsequently points it out or initiates appropriate control measures to interrupt the further stacking process.

[0091] Fig. 5 shows a first example process for determining anomalies when stacking value documents 12, which is to be considered here with reference to Figures 3A to 4B. The target state 37 of the partial area 34 is represented by the reference image 38, and the actual state 36 of the partial area 34 is represented by the captured image 35, for example a first captured image 35a of an image sequence 35a, 35b, 35c captured by the camera unit 30, wherein the evaluation includes the detection of a deviation between the first captured image 35a and the reference image 38. It can thus be provided to create an initial image as a reference image 38 (cf. Figures 3A and 3B), which is subsequently always used as the basis for the evaluation in the processing unit 60. The reference image 38 can therefore form the starting point of the evaluation and be compared with all images 35a, 35b, 35c captured by the camera unit 30 over time t.The reference image 38 can represent an image of an undisturbed stacking process in which no value document 12 has deviated from the movement path. The camera unit 30 can thus capture several consecutive images 35a, 35b, 35c according to a predetermined image capture rate. Each of these captured images 35a, 35b, 35c can be directly compared with the reference image 38 after capture, as indicated by arrows in Fig. 5.

[0092] Fig. 6 shows a second example process for determining anomalies when stacking value documents 12, which in the present case is also to be considered with reference to Figures 3A to 4B. The camera unit 30 is designed to capture an image sequence 35a, 35b, 35c, 35d over the time course t, wherein the image sequence 35a, 35b, 35c, 35d comprises at least a first image 35a with the partial area 34 and a second image 35b with the partial area 34, captured chronologically after the first image 35a, and wherein the evaluation comprises the detection of a deviation between the first image 35a and the second image 35b. The image sequence 35a, 35b, 35c, 35d also includes a third image 35c with the partial area 34, which is captured after the second image 35b, wherein the evaluation includes the detection of a deviation between the second image 35b and the third image 35c.The image sequence 35a, 35b, 35c, 35d also includes a fourth image 35d with the partial area 34, acquired chronologically after the third image 35c, wherein the evaluation includes detecting a deviation between the third image 35c and the fourth image 35d. In other words, the previously acquired image with the partial area 34 is used as the reference image 38, which represents the desired state 37 of the partial area 34. The currently acquired image is used for the actual state 36 of the partial area 34. This procedure is illustrated by the arrows in Fig. 6.

[0093] Fig. 7 shows a third example process for determining anomalies when stacking value documents 12, which should also be considered here with reference to Figures 3A to 4B. Edge detection occurs in each captured image of an image sequence 35a, 35b, 35c, 35d captured by the camera unit 30 over time t. Edge data in the currently captured image 35a, 35b, 35c, 35d (corresponding to the actual state 36 of the partial area 34) can be compared with edge data in the reference image 38, which represents the target state 37 (see Figures 3A and 3B).

[0094] Fig. 8 shows a block diagram or block circuit diagram of individual steps which the device 10 performs for detecting anomalies when stacking value documents 12, including interfaces of the device 10 to a value document processing device 100. The device 10 of Fig. 8 can be the device 10 described in Fig. 1, so that reference is made to Fig. 1 in addition.

[0095] In step S1, the processing unit 60 receives a trigger signal from the value-document processing device 100. The detection unit 50 can, for example, detect the passage of value documents 12 before entering the stacker wheel 22 and send a trigger signal to the processing unit 60 each time a value document 12 passes, for example via a corresponding interface that connects the value-document processing device 100 to the device 10. Alternatively, the trigger signal is generated by the separator cycle or the machine cycle, which is forwarded from the value-document processing device 100 to the processing unit 60.

[0096] The control device 62 of the processing unit 60, integrated into the device 10, can then initiate image capture based on the received trigger signal in step S2 by sending the trigger signal to the camera unit 30 in the form of an image capture command. In step S3, the camera unit 30 receives the image capture command and captures an image accordingly. In particular, exactly one image is captured per processed value document 12.

[0097] In step S4, this captured image is in turn sent to the processing unit 60 and evaluated by the evaluation device 61 of the processing unit 60, specifically according to one or more of the image analysis techniques described above (see, for example, Figures 5 to 7). In particular, the evaluation device 61 detects whether the actual state 36 of the sub-area 34 deviates from a desired state 37 of the sub-area 34 (see, for example, Figures 3A to 4B). During the evaluation, in particular, exactly one result is created for each processed value document 12.

[0098] If a deviation is detected by the evaluation device 61 in step S4, an output information item (“C AN message”) can then be generated in step S5 based on the evaluation, which output information is sent to the value document processing device 100 via an interface of the device 10 as a control signal or is output via a further interface of the device 10 as an indication signal perceivable by an operator of the value document processing device 100.

[0099] The output information can be transferred in step S6 via a CAN bus of the value-document processing device 100. Via the CAN bus of the value-document processing device 100 and a further interface of the device 10, the processing unit 60 can receive activation information or deactivation information for the image capture process in step S7, in order to activate or deactivate image capture by the camera unit 30. Likewise, via the CAN bus of the value-document processing device 100 and a further interface of the device 10, the processing unit 60 can receive configuration information in step S8, which includes, for example, a configuration parameter for the image analysis technique to be used (see Figures 5 to 7) or a configuration parameter for the shape or position of the image 35 to be captured and evaluated (see Figures 2 to 4B).The CAN bus can be implemented, for example, by a digital IO interface and an Ethernet interface. Fig. 9 shows a flow chart for a method for detecting anomalies when stacking value documents. The method can be carried out, for example, using the device 10 as described with reference to Fig. 1. The method is configured to detect anomalies when stacking value documents 12, which are stacked to form a value document stack 14 in a stacker area 20 having a stacker wheel 22 and a stacker compartment 24. In a step S100, an image 35 is captured by a camera unit 30 such that the captured image 35 represents an actual state 36 in at least one partial area 34 of a detection area 32 of the camera unit 30, wherein the partial area 34 is located outside the stacker wheel 22 and the value document stack 14.In a step S200, the captured image 35 is evaluated by a processing unit 60, wherein a detection is made as to whether the actual state 36 of the partial area 34 deviates from a desired state 37 of the partial area 34. In a step S300, the processing unit 60 generates output information based on the evaluation.

Claims

P a t e n t a n s p r ü c h e 1. Device (10) for detecting anomalies during the stacking of value documents (12) which, during automatic value document processing, are stacked to form a value document stack (14) in a stacker area (20) having a stacker wheel (22) and a stacker compartment (24), comprising: a camera unit (30) with a detection area (32) which comprises at least a partial area (34) of the stacker area (20) which is located outside the stacker wheel (22) and outside the value document stack (14), wherein the camera unit (30) is designed to capture an image (35) which represents an actual state (36) in at least the partial area (34) outside the stacker wheel (22) and the value document stack (14), and a processing unit (60) which is designed to evaluate the image (35) captured by the camera unit (30), wherein during the evaluation, based on the captured image (35) is detected,whether the actual state (36) of the sub-area (34) deviates from a target state (37) of the sub-area (34), wherein the processing unit (60) is further designed to generate output information based on the evaluation.

2. Device (10) according to claim 1, wherein the processing unit (60) is designed to detect, on the basis of the captured image (35), a deviation between the actual state (36) of the partial area (34) and the desired state (37) of the partial area (34), which allows the conclusion that a value document (12) is present within the partial area (34).

3. Device (10) according to one of the preceding claims, wherein the camera unit (30) is designed to capture an image sequence from a plurality of the images (35) using an image capture rate and to evaluate the images (35) of the image sequence, preferably individually, and wherein the image capture rate corresponds in particular to a predetermined value document processing rate or an integer divisor of the value document processing rate at which the value documents are transported to the stacker area (20) during automatic value document processing.

4. Device (10) according to one of the preceding claims, wherein the camera unit (30) is designed to carry out the evaluation of the individual images already during the stacking of the value documents and to generate the output information based on the evaluation already during the stacking of the value documents.

5. Device (10) according to one of the preceding claims, wherein the camera unit (30) is designed to capture an image sequence, wherein the image sequence comprises at least a first image (35a, 38) with the partial area (34) and a second image (35b, 35c, 35d) with the partial area (34) captured chronologically after the first image (35a, 38), and wherein the evaluation comprises detecting a deviation between the first image (35a, 38) and the second image (35b, 35c, 35d), and wherein the processing unit is designed to generate the output information as a function of the deviation between the first image (35a, 38) and the second image (35b, 35c, 35d).

6. Device (10) according to one of the preceding claims, wherein the desired state (37) of the partial area (34) is predetermined by a reference image (38) representing the partial area (34) in the desired state, and wherein the evaluation comprises the detection of a deviation between the captured image (35) representing the partial area in the actual state and the reference image (38), and wherein the processing unit is designed to generate the output information as a function of the deviation between the captured image (35) and the reference image (38).

7. Device (10) according to claim 6, wherein the evaluation comprises edge detection in the captured image (35) and in the reference image (38), and wherein the evaluation comprises detection of a deviation between the edges detected in the captured image (35) and the edges detected in the reference image (38), and wherein the processing unit is designed to generate the output information as a function of the deviation between the edges detected in the captured image (35) and the edges detected in the reference image (38).

8. Device (10) according to one of claims 6 to 7, wherein the desired state (37) of the partial area (34) is represented by pixel data of the reference image (38) representing the partial area (34) in the desired state; wherein the actual state (36) of the partial area (34) is represented by pixel data of the captured image (35), and wherein the evaluation comprises detecting a deviation between the pixel data of the reference image (38) and the pixel data of the captured image (35), and wherein the processing unit is designed to generate the output information as a function of the deviation between the pixel data of the reference image (38) and the pixel data of the captured image (35).

9. The device (10) according to claim 8, wherein detecting the deviation between the pixel data of the reference image (38) and the pixel data of the captured image (35) comprises determining an intensity difference between pixels of the reference image (38) and respective corresponding pixels of the captured image (35), and wherein the evaluation further comprises determining whether the determined intensity difference between the pixels of the reference image (38) and the pixels of the captured image (35) exceeds a threshold intensity difference, and wherein the processing unit is designed to generate the output information depending on whether the determined intensity difference between the pixels of the reference image (38) and the pixels of the captured image (35) exceeds the threshold intensity difference or not.

10. The device (10) according to claim 9, wherein the evaluation further comprises determining whether the determined intensity difference exceeds the threshold intensity difference for a minimum number of pixels, and wherein the processing unit is configured to generate the output information depending on whether or not the determined intensity difference exceeds the threshold intensity difference for a minimum number of pixels.

11. Device (10) according to one of the preceding claims, wherein the output information corresponds to an output signal for an operator, which in particular causes a warning to the operator of a malfunction in the stacker area, and / or wherein the output information corresponds to a control signal for the stacker area automatic value document processing, which in particular causes the automatic value document processing to be stopped.

12. Device (10) according to one of the preceding claims, wherein the image (35) evaluated during the evaluation is selected such that only one or only several partial areas (34) of the stacker area are shown thereon, which are located outside the stacker wheel (22) and outside the valuable document stack (14), in particular formed in the stacker compartment (24).

13. Device (10) according to one of the preceding claims, wherein the partial area (34) located outside the stacker wheel (22) and the value document stack (14) - comprises an area (34a) between the stack of valuable documents (14) and a side wall (29) of the stacker compartment (24), and / or - comprises a region (34d) adjacent to an outer circumference of the stacker wheel (22) and extending within a housing (28) of the stacker region (20), and / or - comprises an area (34b) encompassing the stacker compartment (24), in particular when there is no stack of valuable documents in the stacker compartment (24).

14. A value document processing device (100) for automatically processing value documents, comprising a device (10) for detecting anomalies when stacking value documents (12) according to one of the preceding claims and a stacker area (20) with a stacker wheel (22) and a stacker compartment (24) for stacking value documents (14).

15. A method for detecting anomalies during the stacking of value documents (12) which are stacked to form a value document stack (14) during automatic processing of the value documents in a stacker area (20) having a stacker wheel (22) and a stacker compartment (24), comprising: - capturing an image (35) by a camera unit (30) such that the captured image (35) represents an actual state (36) in at least one partial area (34) of a capture area (32) of the camera unit (30), wherein the partial area (34) is located outside the stacker wheel (22) and the value document stack (14) (S100), and - evaluating the captured image (35) by a processing unit (60), wherein during the evaluation, it is detected on the basis of the captured image (35) whether the actual state (36) of the partial area (34) deviates from a desired state (37) of the partial area (34) (S200), and - generating output information by the processing unit (60) based on the evaluation (S300).

Images