Patent ID: 12217416

DETAILED DESCRIPTION

In the figures, the same reference numbers denote the same, similar or corresponding elements. Elements depicted in the figures are not necessarily represented to scale. Rather, the various elements shown in the figures are presented in such a way that their function and general purpose can be understood by those skilled in the art. Connections and couplings, shown in the figures, between functional units and elements can also be implemented as an indirect connection or coupling, unless expressly stated otherwise. Unless specifically stated otherwise, functional units can be implemented in particular as hardware, software or a combination of hardware and software.

FIG.1illustrates an exemplary embodiment100of the method for controlling a coating device for surface-selectively coating a surface of an individual physical document with a liquid coating. For this purpose,FIG.2illustrates a sequence200of different intermediate states that are reached as part of the method100. For this reason, reference is also made toFIG.2in the description of method100.

As part of method100, reference image information is generated in a process105based on an in particular card-like sample document225(or an image, in particular photos thereof), which information, as reference image225A, represents an image of a reference surface serving as an error-free reference of sample document225. The reference image information or the reference image225A can be obtained in particular by (digital) photographing the surface of the sample document, preferably in the form of digital image data.

The reference image225A shows a pre-printed background image230, a representation of an electronic chip235, which is integrated in the sample document, as well as an identifier composed of a text element240-1, and a graphic element240-2, which identifier is present on a plurality, in particular several different documents v to be coated according to the method. For example, this can be the name and a logo of an issuer of the document, for example in the case of a bank or credit card of a bank or a credit card company.

In a further process115a, the two image elements240-1(text element) and240-2(graphic element) are extracted from the reference image225A by image processing using a color-dependent analysis criterion. According to the analysis criterion, the image elements240-1and240-2to be extracted are characterized by a certain predefined color (shown as black surface in the figures), which differs from the color of the background image230. Instead of a single color, a specific color range in a defined color space (such as RGB) can also be used as a color-dependent analysis criterion, so that only image elements are extracted, the coloring of which lies within this color range.

Alternatively or cumulatively with a color-dependent analysis criterion, a surface structure-dependent analysis criterion can also be used, so that only surface regions or image elements which have a surface structure detected by sensors, which correspond to a specified surface structure (such as roughness or material property) or lie within a specified reference structure region, are extracted as image elements or surface regions to be coated.

In addition, alternatively or cumulatively, a form recognition process can be used in order to recognize at least one form element represented in the reference image225A from a predefined set of forms as at least a partial target form. This makes sense in particular with regard to the recognition of text elements or other predefined characters or character chains (such as using OCR technology), in which case the range of shapes (alphabet, for example) can serve as an analysis criterion.

In process115a, geometry information245is generated using the analysis criterion, which information represents, for example in the form of a layout, these two image elements240-1and240-2and their respective position and orientation within reference image225A (in the form of corresponding data). The image elements240-1and240-2at least partially define a target shape (in particular form) of a partial surface of the surface of at least one document205to be provided with a liquid coating, but typically of a plurality of such documents205of the same type. The target shape accordingly comprises here at least the two non-contiguous surface regions240-1and240-2.

The processes105and115acan in particular be carried out before the further process steps described below.

The method100also comprises a process110in which image information (“actual image information”) is generated by image sensors with a vision system (in particular a camera) or is received in the form of image data from a data source, wherein the image information represents an image (“actual image”)205A of a relevant surface of a document205to be coated.

The actual image205A has a pre-printed background image210, a representation of an electronic chip215, which is integrated in the document205, as well as an identifier composed of a text element220-1, and a graphic element220-2, which identifier is present on a plurality, in particular several different documents205to be coated according to the method. For example, as in sample document225, this can be the name and a logo of an issuer of the document, for example in the case of a bank or credit card of a bank or a credit card company. In addition, the actual image205A contains a further image element220-3, which is document-specific information (in particular personalization) that is not already present on the sample document225or its image225A. The actual image205A thus differs from the reference image225A at least by the image element220-3. A further difference, however, in the present example ofFIG.2is that due to a deformation of the surface of the document205, the image elements220-1to220-3in a plan view of the document205and correspondingly in its image (actual image)205A appear distorted (illustrated here by a skewing of the picture elements), while they appear undistorted in the reference image225A.

In a first embodiment variant of the method100, the actual image205A is compared with the reference image225A as part of a process120ain order to be able to use any deviations to infer a potential deformation of the document205or its surface compared to a flat shape. In the present example, the distortions in the actual image205A with regard to the image elements220-1and220-2compared to the corresponding image elements240-1or240-2are recognized and a type and extent of a corresponding deformation is reconstructed and used as the resulting deformation information (in data form). This can be done in particular by a suitably adapted machine-learning-based process, such as using a suitably trained artificial neural network.

In a further process115b, similar to process115a, such image elements220-1to220-3which correspond to the analysis criterion are extracted using an analysis criterion which can correspond in particular to that from process115a.

According to a second embodiment variant of the method100, instead of the process120a, a process120btakes place to compare the geometric data245resulting from the process115awith the geometric data250resulting from the process115bin order to correspondingly, as described above, recognize a potential deformation of the document205and to generate corresponding deformation information. The use of process120binstead of process120ahas the advantage that the comparison can already be carried out on the basis of the extracted image elements and thus without taking into account the full complexity of images225A and205A including their other image contents (210,215,230,235).

The target shape of the liquid coating to be produced is then obtained by combining the geometric information245and250, so that the target shape contains the image elements240-1,240-2and additionally the image element220-3. It should be pointed out that depending on the application and embodiment of the method, the target shape can also be derived exclusively from the geometry information245or from the geometry information250or can be defined thereby. The former makes sense in particular when only surface regions of the document205are to be coated which are already represented by corresponding image elements in the reference image225A, while the latter is particularly relevant when surface regions are to be coated with document-specific information. Insofar as mutually corresponding image elements are contained in the two items of geometry information245and250, preferably only one of them is adopted in each case in order to avoid duplication.

In a further process125, in particular on an optical basis, an orientation of the document205to be coated relative to the coating device used for its coating can be detected by sensors. Thus, in particular, any deviation from a target alignment can be recognized and taken into account in a further process130in the subsequent definition of a coating information255that defines a coating layout.

In the process130, the previously obtained geometry information defining the target shape, the determined orientation of the document205and the deformation information serve as input variables. As a result, the process130supplies the coating information255, which in particular represents a coating layout for a liquid coating to be applied to the document205by a coating device. Depending on the deformation information, as part of process130, image elements220-1to220-3are included in the image information or in the coating layout in such a distorted form that this distortion at least partially compensates the deformation-related distortion of these image elements in actual image205A or in the geometry information250(similar to how a barrel distortion as counter-distortion can compensate an original pincushion distortion). The generation of the coating information can, in particular, also include a conversion in the sense that a coloring of the partial surface to be coated that is optionally contained in the geometry information and is defined by the actual image information is converted into a different “coloring”, in particular black/white or shades of gray, in order to control the application of the liquid coating. The new coloring can then encode in particular a location-dependent variable thickness of the liquid coating to be applied or a coloring of the same.

A further process135follows, in which a coating device is controlled in accordance with the coating information in order to provide the surface of the document205with a liquid coating in accordance with the coating layout. The coated document260thus results in that the original deformation-related distortion of the image elements220-1to220-3is at least partially, ideally as here completely, compensated (cf. undistorted image elements260-1to260-3).

The target shape of the liquid coating to be produced is then obtained by combining the geometric information245and250, so that the target shape contains the image elements240-1,240-2and additionally the image element220-3. It should be pointed out that depending on the application and embodiment of the method, the target shape can also be derived exclusively from the geometry information245or from the geometry information250or can be defined thereby. The former makes sense in particular when only surface regions of the document205are to be coated which are already represented by corresponding image elements in the reference image225A, while the latter is particularly relevant when surface regions are to be coated with document-specific information.

In a further process125, in particular on an optical basis, an orientation of the document205to be coated relative to the coating device used for its coating can be detected by sensors. Thus, in particular, any deviation from a target alignment can be recognized and taken into account in a further process130in the subsequent definition of a coating information item255that defines a coating layout.

In the process130, the previously obtained geometry information defining the target shape, the determined orientation of the document205and the deformation information serve as input variables. As a result, the process130provides the coating information255, which in particular represents a coating layout for a liquid coating to be applied to the document205by a coating device and defines a shape (“actual shape”) of the surface regions to be coated (combined: “partial surface”). Depending on the deformation information, as part of process130, image elements220-1to220-3are included in the image information or in the coating layout in such a distorted form that this distortion at least partially compensates the deformation-related distortion of these image elements in the actual image205A or in the geometry information250(similar to how a barrel distortion as counter-distortion can compensate an original pincushion distortion). Also this process130can be performed in particular by a suitably adapted machine-learning-based process, such as using a suitably trained artificial neural network.

A further process135follows, in which a coating device is controlled in accordance with the coating information in order to provide the surface of the document205with a liquid coating in accordance with the coating layout. The coated document260thus results in that the original deformation-related distortion of the image elements220-1to220-3is at least partially, ideally as here completely, compensated (cf. undistorted image elements260-1to260-3). The surface-selective coating takes place here only in the region of the surface regions representing the image elements255-1to255-3(collectively: “partial surface”), while the other regions of the surface of the document260resulting from the coating from document205remain uncoated.

Optionally, only one further process140can follow, in that a limited image portion220is identified in the actual image on the basis of the results of process115b, within which the image elements220-1to220-3extracted according to the analysis criterion lie. This image portion220can now be defined as an image analysis region for subsequent further method executions with regard to further documents in such a way that the process115bis carried out there only with regard to this limited image analysis region. The process140can also be defined in such a way that it refers to an entire ensemble of previous executions of the process115bincluding the last process run carried out in relation to document205and defines the image analysis region based on a plurality, in particular all, of the corresponding image portions from this ensemble of process runs. The process140is or can be defined accordingly in particular in such a way that the currently determined image portion is compared with an image portion resulting from earlier process runs of this process, and an adjustment of the image portion only takes place if the last determined image portion extends beyond the image portion resulting from earlier process runs.

Finally,FIG.3illustrates an exemplary system300for performing the method100comprising a coating process controlled according to the process135itself.

The system300has a plurality of modules305to325connected in series within the framework of a processing path and is configured in particular to carry out the method100. A first module is configured as an input module305and is used to receive the documents to be coated, which can be supplied in particular as a stack of documents, and then to supply them individually to the next module310for further processing. Furthermore, the input module305can also be configured to receive a sample document225and to supply it to the module310. For this purpose, either the same transport route can be used as for documents205, or a separate, dedicated transport route for sample documents225can be used.

Module310is a module configured for image acquisition and process control. In particular, it can have a processor platform310awith one or more processors, an associated program and data memory310band an image sensor system (in particular a camera)310cfor generating the actual image information and the reference image information. A computer program is stored in the memory310b, which is designed and configured to be executed on the processor platform310ain order to control the system300in such a way that it executes the method100. The processor platform310aand the data storage together form a data processing device.

The next module315along the processing path is configured as a module for chip coding of the chip215on the document205. In particular, this can be done using contacts or wirelessly, depending on the type of document205and/or the corresponding communication capability of the system300.

The further module320follows along the processing path, which is configured, under corresponding control by the computer program, to carry out a surface-selective liquid coating (including application and curing of the coating, in particular by irradiation with ultraviolet light (UV)) of the document205. The module320accordingly represents a coating device within the meaning of the method100and can be configured in particular for printing the document205with the liquid coating, for example as an inkjet printer.

The next module is a module325for quality control, which in turn can have an image sensor system, such as a photo or video camera, in order to capture and check the coated documents260(seeFIG.2) using an image sensor for quality control purposes.

Finally, there follows an output module330for the coated documents260, which can be configured in particular in such a way that, depending on the results of the quality control carried out in module325, it outputs error-free documents on the one hand and faulty documents on the other hand, in different ways. In particular, documents with errors can be ejected from the process flow before the documents recognized as being error-free are output, which can in particular include a stacking of the documents to be output.

While at least one exemplary embodiment has been described above, it is to be noted that a large number of variations thereto exist. It is also to be noted that the exemplary embodiments described only represent non-limiting examples, and are not intended to restrict the scope, the applicability, or the configuration of the devices and methods described herein. Rather, the preceding description will provide those skilled in the art with guidance for implementing at least one exemplary embodiment, wherein it is apparent that various changes in the operation and arrangement of elements described in an exemplary embodiment may be made without departing from the scope of the subject matter defined in the appended claims and its legal equivalents.