EP3036524A1

EP3036524A1 - Device and method for identifying codings under a transparent film

Info

Publication number: EP3036524A1
Application number: EP14746989.4A
Authority: EP
Inventors: Jürgen-Peter HERRMANN; Marius Michael Herrmann; Wolfgang Schorn
Original assignee: KHS GmbH
Current assignee: KHS GmbH
Priority date: 2013-08-20
Filing date: 2014-07-25
Publication date: 2016-06-29
Also published as: CN105473997A; RU2623815C1; BR112016002510A2; JP2016528505A; US9842237B2; DE102013109005A1; WO2015024734A1; MX2016002112A; US20160247007A1; JP6516744B2

Abstract

The invention relates to a method for identifying an object covered by a transparent layer at least in some sections by determining a surface property. In order to provide a method by means of which property parameters of a surface of an object, which surface is covered by a transparent layer, can be determined especially simply and reliably, an optical system according to the invention detects at least two polarization planes of light that is reflected by the surface of the object and the surface of the transparent layer and determines the surface property, while taking into account the detected polarization planes, in order to identify the object.

Description

DEVICE AND METHOD FOR IDENTIFYING CODINGS

UNDER A TRANSPARENT FOIL

The invention relates to a method and a device for identifying an at least partially covered by a transparent layer counter state by determining a surface property.

The surfaces of basically the same objects can be clearly distinguished from each other with a sufficiently accurate examination. This is partly true for the macroscopic range, but in any case in the microscopic range. Ultimately, therefore, no two objects are completely identical.

For identifying objects, in particular for checking their origin or authenticity, it is therefore known, for example, to determine property parameters of a surface section of the object and to convert them into one or more characteristic digital values. That is, properties of the natural surface are sampled and determined to derive therefrom measurements which, in turn, correspond to digital values characteristic of the surface.

However, the detection of the surface property is made more difficult, for example, by different light conditions during the initial determination of the parameters and during a subsequent verification process, since, for example, the light striking the surface produces reflections on the surface of the object which are dependent on the light conditions. Also, for example, the positioning of the object when first collecting the property parameters and in a further review may be different, so that in this way also different reflections arise that affect each determined data.

The determined property parameters thus often do not correspond to the surface of the article itself, but are strongly influenced by the different environmental conditions. A comparison of the original and the reviewed records can thus lead to errors in the identification. The invention is therefore based on the object to provide a method and a device, with the property parameters of a surface of an object can be determined particularly simple and reliable.

The invention achieves the object by a method having the features of claim 1 and a device having the features of claim 8. Advantageous developments of the invention are specified in the dependent claims. A basic idea for the invention was the problem that previous surface recognition methods could not be applied to surfaces which are covered by a transparent layer, such as a cellophane film, since the light reflections arising on the transparent layer make correct detection of the property parameters difficult or completely impossible.

The inventive method for identifying an object at least partially covered by a transparent layer by determining a surface property is performed with an optical system that detects at least two planes of polarization of light reflected from the surface of the article and the surface of the transparent layer and taking into account the detected polarization planes determines the surface property for identifying the object. Due to the different polarization planes, it is possible to filter out a polarization plane in which the detected image has a larger number of disturbances, for example light reflections, during the detection of the property parameters. That is, the property parameters are recorded as possible in each possible polarization plane of the optical system as an image and processed by the optical system, for example, converted to a data set and stored. During detection, processing or conversion, the optical system ignores completely the polarization planes in which the light reflections occur Optical system is designed such that it disregards areas in polarization planes in which it detects unwanted light reflections when creating the property parameters. It should be noted that in the context of this invention, surface properties are understood to mean the entire reflection profile of the surface, which includes both inherent (natural) properties, structures, material properties, and roughness, as well as artificially created properties due to or introduced markings, embossing, structures, colors, etc. The optical system thus determines the property parameters of the surface of the object largely without, in particular the generated by the surface of the transparent layer, disturbing light reflections.

The inventive method thus makes it possible to detect and determine exclusively the surface properties of the object, in particular without the influence of the above-arranged transparent layer, so that it is also possible, for example, to check the property parameters at a later point in time, to which the article no Transparent layer has more sense to compare the newly determined property parameters with the originally determined property parameters meaningful.

The optical system may be formed of a plurality of image sensing devices, for example of a plurality of image sensors, each having a polarizing filter, wherein the polarizing filters are aligned offset from each other. Also, for example, an image capture device may be arranged with a rotatable polarization filter, which is moved to acquire the data in different positions. However, in at least two positions of the polarization filter, a capture of the data must be performed. According to a development of the invention, the optical system has a polarization sensor, ie an image sensor which has a multiplicity of polarization filters and which simultaneously detects at least two or more polarization planes. Such polarization sensors are known, for example, from DE 10 2008 014 334 A1 or DE 20 2012 010 977 U1. The use of such a polarization filter thus enables a particularly rapid detection of the property parameters in multiple polarization planes. This makes it possible, in particular in an industrial application, to adapt the speed of passage of the objects through the optical system to the speed of passage of the objects through an industrial device.

The surface properties determined by the optical system are particularly preferably natural surface properties, such as parameters for microstructure, roughness, color or also surface tension. In this case, the optical system can be designed to jointly determine individual property parameters as well as parameters of different properties. Accordingly, the "fingerprint" of the surface portion that can be generated by the optical system can also contain a multiplicity of different parameters, thereby significantly increasing the identification accuracy of the object.

As stated above, both natural and artificial properties can be detected, i. In principle, all optically detectable properties can be used for identification, so that the surface properties can also be applied or introduced properties. These include, for example, markings introduced into the surface, for example embossings or markings applied to the surface, such as characters, characters, color markings, codes, in particular a dot code, barcode or matrix code and / or other artificial structures which are to be used for identification However, under a transparent layer can not be detected with sufficient certainty. It may also be, for example, surface properties which under normal light are not clearly or sufficiently clearly visible to the human eye, but which, for example, become visible through the polarization of the reflected light.

Under a transparent layer, all surfaces or surfaces are chen section of an object covering layers understood that are transparent, ie transparent. This may for example be a transparent layer, which is formed as a coating. Such a coating can be permanently or detachably connected to the surface. These can be, for example, high-gloss coated packaging papers or else lacquer coatings on, for example, machine components.

According to a development of the invention, however, the transparent layer is formed as a film. The foil covers at least a portion of the object which is to be used for identification. It can also wrap the object completely. Typical examples are transparent films which at least partially encase the article itself or an outer packaging and, for example, protect it against external influences. These include e.g. Cellophane films, shrink films or transparent transport films.

The transparent layer may in principle be colored, whereby it must be ensured that it has at least a minimum of transparency. It is thus minimally transparent in each case, so that an optical system can detect the surface arranged below the layer. Preferably, however, the transparent layer is colorless, since the detection of the surface properties by a colorless transparent layer is particularly simple.

The method can basically be used with any object whose surface section identified for identification is covered by a transparent layer. Thus, for example, machines, machine parts, consumer goods, foodstuffs, pharmaceuticals or pharmaceutical packaging or the like which are at least partially covered by a transparent layer can be identified by means of the inventive method. However, particularly preferably objects whose surface consists of paper and / or plastic, in particular a paper packaging and / or plastic packaging, are identified with the inventive method. Due to the high number of product counterfeits, there is an increased need for identification in cigarettes, for example. Both cigarette packaging and cigarette tube packaging are covered with cellophane wrap to protect against moisture and dirt. This can for example be double-layered even at the end sides in sections, so that it is impossible to determine the property parameters of a surface section arranged below the two-ply film.

By the inventive method, it is possible, for example. Before packaging the cigarette rods in cartons a surface portion of the individual cigarette packs enveloping outer packaging safely and without the effects of occurring light reflections to capture and, for example, to save in a central database. In this case, for example, surface sections arranged under double-layered transparent layers and their natural or artificial surface properties can also be detected. In the case of seized cigarettes, for example, authorities can again record the properties of the surface of the outer packaging, compare the data obtained with the data stored in the database and thus determine whether there is any product counterfeiting or, if necessary, the original cigarette chain supply chain.

In order to be able to retrieve the property parameters originally acquired by the optical system for identifying the object at a later time at any time, the determined parameters are particularly preferably processed by the optical system, in particular represented and stored as digital values. These digital values are unique to the subject surfaces and, as it were, represent a fingerprint of the surface, thus uniquely characterizing them. Depending on the parameter type determined, there should be a high degree of agreement between the original and the data determined during the check for the purpose of reliable identification.

The optical system therefore particularly preferably has a data processing unit, such as, for example, a microprocessor and possibly a memory unit or a memory unit. Binding unit for example. Wireless connect to a storage unit on. Alternatively or additionally, the data records can be stored on the object itself, for example in the form of a matrix or bar code. In order to limit the effort involved in capturing and, in particular, the amount of data recorded, only a defined section area of the surface is usually detected. The number of surface parameters determined via the inventive section size is particularly suitable for ensuring reliable identification and limits the effort, in particular the acquisition, processing and storage of the property parameters, to a minimum.

Further, the invention solves the problem by a device for identifying an object, wherein the article

- At least partially covered by a transparent layer and

is arranged with the covered portion in the detection range of an optical system,

- The optical system is adapted to detect at least two polarization planes of a light reflected from the surface of the article and the surface of the transparent layer and light

taking into account the detected planes of polarization, to determine the surface property for identifying the object.

The inventive device is designed to detect different polarization planes of the reflected light and to filter out the plane in which a plurality of light reflections is present. This can be done, for example, in such a way that complete polarization planes or section regions of detected polarization planes in which the optical system determines light reflections are disregarded during recording or processing or when creating a data record.

The object to be identified can in principle be any object whose surface section to be identified differs from a transparent layer. is covered. Thus, the design of the device may be different. Thus, for example, it is possible to permanently install an inventive device in different devices or to design the device as a mobile unit. Direct contact between the optical system and the object need not be present.

The inventive device also makes it possible for the device to reliably determine the property parameters in the case of a different positioning of the object in front of the detection area of the optical system or else in different light conditions when determining the property parameters, so that the device is particularly suitable for mobile use.

Although some aspects have been described in the context of a method, it will be understood that these aspects also constitute a description of the corresponding apparatus. Similarly, aspects described in the context of a device are also to be understood as a description of a corresponding method step or as a feature of a method step.

Furthermore, the invention will be described in detail with reference to an embodiment.

Fig. 1. shows schematically in a perspective view of an optical system and a transported on a treadmill object;

FIG. 2 schematically shows an enlarged cross section through the surface of an identification portion of the article of FIG. 2. FIG.

3 shows schematically in a perspective view the optical system from FIG. 1 with an article with a point code.

FIG. 1 schematically shows a cigarette rod 2 with an outer package 2a, which is covered by a transparent layer 1 designed as a cellophane film (here as a punk). tete line shown) is wrapped. The cigarette rod 2 is transported on a conveyor belt 7 to a packaging unit (not shown here). In this case, the cigarette rod 2 is positioned on the transport such that it faces an end face 2b to a lens 3a of an optical system 3.

The optical system 3 has a polarization camera 4, which is designed for high-resolution recordings. The polarization camera is connected to a data processing and storage unit 5. The polarization camera 4 has a polarization sensor (not shown here), that is to say an image sensor with polarization filters, which simultaneously detects four different polarization planes of light.

The polarization camera 4 is thus designed to detect a surface structure, in particular parameters for surface roughness, and to create a reflection profile of the scanned surface using a data processing and storage unit 5 belonging to the optical system 3 from the determined property parameters and to convert this into a data value. Alternatively, for example, a mark applied to the object, such as, for example, a point code, bar code or matrix code or a marking introduced into the surface, such as, for example, an embossing mark, could also be detected.

In operation, the polarization camera 4 is arranged aligned with the conveyor belt such that it detects an identification section 6 present below the transparent layer 1 (shown here as a cross-hatched area) at the upper right corner of the cigarette rod 2.

The cigarette rod 2 is transported by means of the conveyor belt 7 through the detection area (shown by dashed lines) of the polarization camera 4. In this case, the polarization camera 4 scans the identification section 6, ie, the light reflected from the surface of the cellophane film and the surface of the outer package 2a of the cigarette rod 2 intercepts four polarization planes and transmits the information to the data processing unit 5. The identification section is located there 6 due to the folding of the cellophane film on the front side 2b of the cigarette rod 2 each partially under two or a layer of cellophane, resulting in a variety of different reflections.

The polarization camera 4 records the property parameters of the surface determined in two or more planes of polarization, filters out the regions of the identification section 6 in which light reflections have disturbed the detection of the surface parameters of the outer packaging 2a and creates a reflection profile of the filtered polarity of the four polarization planes detected surface portion of the outer packaging, and calculated from the properties of two and more polarization planes a reflection profile of the detected surface area of the outer packaging.

The reflection profile is converted by the data processing unit 5 into a data record and stored in the data storage unit 5, so that it is easily retrievable for later comparison with newly determined property parameters.

Figure 2 shows schematically a cross section through the identification section 6 of the cigarette rod 2. The cigarette rod 2 consists of the outer package 2a, which covers a plurality of individual cigarette packs (not shown here). The outer package 2a is made of paper. The paper has individual surface properties, here a surface roughness (shown schematically by a wave form), which can be detected by the high-resolution polarization camera 4 of the optical system 3. Alternatively, an applied mark, such as a code could be detected.

Above the surface section to be detected (identification section 6), the outer packaging 2a is covered by a colorless, transparent cellophane film.

Upon incidence of light on the cigarette rod 2, the light is reflected both from the surface of the cellophane film and from the surface of the paper (outer package 2a) in different polarization planes. This results in light reflections, especially on the surface of the cellophane film, which produce a exact detection of the surface structure of the outer packaging 2a (paper) hinder.

By detecting the light reflected by the identification section 6 in different polarization planes, the optical system 3 can filter out the interfering light reflections during the processing of the determined property parameters, or disregard them when creating a data set for the determined surface parameters.

FIG. 3 shows the optical system 3 and the conveyor belt 7 from FIG. 1. On the conveyor belt 7 is a cigarette rod 2 with a printed on the outer packaging 2a of the cigarette rod 2 point code eighth

(Dot code) past the optical system 3. According to the identification section 6, the dot code 8 is covered by a cellophane film (transparent layer 1), which, on account of the folding of the cellophane film on the front side, covers it one by one or in two layers. The determination of the point code 8 by the optical system 3 is carried out according to the preceding explanations to FIGS. 1 and 2.

As an alternative to a point code 8, any other applied characteristic drawing, for example also characters, color markings, bar or matrix codes can be applied and read out by the optical system 3.

Claims

claims

1 . Method for identifying an object covered at least partially by a transparent layer (1) by determining a surface property by means of an optical system (3), wherein

the optical system (3) comprises a polarization camera which is designed for high-resolution recordings and connected to a data processing and storage unit (5), and wherein the polarization camera has a polarization sensor, and by means of which at least

two polarization planes of light reflected from the surface of the article and the surface of the transparent layer (1) are detected and

- Taking into account the detected polarization planes, the surface property for identifying the object is determined

2. The method according to claim 1, characterized in that the optical system (3) comprises an image sensor with polarization filter, which detects at least two or more polarization planes simultaneously.

3. The method according to claim 1 or 2, characterized in that the surface structure, the microstructure, roughness, color and / or as a surface property marking on the surface, in particular a point code, matrix code or barcode is detected.

4. The method according to any one of the preceding claims, characterized in that the transparent layer (1) is formed as a transparent film.

5. The method according to any one of the preceding claims, characterized in that the surface of the article of paper and / or plastic, in particular a paper packaging and / or plastic packaging, is.

6. The method according to any one of the preceding claims, characterized in that the surface property processed, in particular digitized and stored.

7. The method according to any one of the preceding claims, characterized in that for identifying the object, the property of the already determined surface portion is again determined and compared with the first determined and stored property data.

8. An apparatus for identifying an article, wherein the article

- At least partially covered by a transparent layer (1) and

is arranged with the covered portion in the detection range of an optical system (3),

- The optical system (3) is adapted to detect at least two planes of polarization of a light reflected from the surface of the article and the surface of the transparent layer (1) and to determine, taking into account the detected polarization planes, the surface property for identifying the object

the optical system (3) has a polarization camera which is designed for high-resolution images, which are furthermore connected to a data processing and storage unit (5), and wherein the polarization camera has a polarization sensor by means of which four different polarization planes of light can be detected simultaneously.