EP3341204A1

EP3341204A1 - Method and system for printing containers

Info

Publication number: EP3341204A1
Application number: EP16744782.0A
Authority: EP
Inventors: Stefan MAGERSTEDT; Katrin Preckel
Original assignee: KHS GmbH
Current assignee: KHS GmbH
Priority date: 2015-08-26
Filing date: 2016-07-28
Publication date: 2018-07-04
Also published as: CN107921788B; US10538110B2; BR112017028588A2; WO2017032546A1; DE102015114172A1; US20180250954A1; JP2018526247A; CN107921788A

Abstract

The invention relates to a method for printing a printed image on a container, comprising the following steps: providing printing metadata which include at least information in respect of the geometry of the container to be printed; providing first printed image information which includes data of a printed image to be applied to the container; providing coding data which includes information to be applied to the container, such as in steganographically coded form, for example; selecting a local region where the coding data are to be arranged in the printed image or on the container, based on the printing metadata; generating coded printed image information by modifying the first printed image information based on the coding data, wherein the first printed image information is selectively modified in respect of location based on the selected local region; and printing a printed image on the container based on the coded printed image information by means of at least one print head in a direct printing method.

Description

Method and system for printing on containers

The invention relates to a method for printing containers according to the preamble of claim 1 and to a system for container printing according to the preamble of claim 15.

Devices for printing containers are known in different designs. In particular, printing systems for printing on containers using digital ink jet or ink jet printing heads are known. In particular, printing systems or printing machines (eg DE 10 2007 050 490 A1) are known in which a plurality of treatment or printing stations for receiving in each case a container to be printed are formed on a at least one vertical axis driven transport element, where the container under Use of electronically controllable, operated by the inkjet or ink-jet principle, digital printheads are printed.

The main advantage of the direct printing of containers is that, in contrast to the equipment of containers with pre-printed labels, a highly flexible container printing is possible, which is particularly suitable for the equipment of containers for small series or events.

In particular, in the food industry there is a need to ensure delivery routes of containers, for example bottles filled with a filling material, or to be able to allocate a batch of containers to a manufacturer or bottler or to a specific container treatment machine.

Proceeding from this, it is an object of the invention to provide a method for container printing, by means of which a traceability of the container can be ensured. The object is achieved on the basis of the preamble of independent claim 1 by its characterizing features. A system for printing on containers is the subject of the independent patent claim 15. According to a first aspect, the invention relates to a method for printing on a container with a printed image. In particular, the printing takes place in a direct printing process by applying printing ink or printing ink to the container outer wall by means of a digital, working on the inkjet principle printhead. First, print metadata is provided or received at a corresponding interface of a printing system, wherein the print metadata include at least information regarding the geometry of the container to be printed. In particular, the geometry information contains exact, three-dimensional data of the container to be printed, for example also grooves, beads, bulges, embossings, etc. As print metadata, information is generally referred to below that has an influence on printing parameters, for example the placement of the printed image or the coding data ,

Furthermore, first print image information is provided which contains data of a printed image to be attached to the container. For example, the first print image information can be provided as an image file, pixel graphics or vector graphics. These can be in particular TIF, BMP or JPG files. The first print image information in this case preferably contain all information that is to be recognized by the naked human eye recognizable on the container, i. in particular texts, pictures, line or matrix codes etc.

In addition, encoding data is provided that contains information to be attached to the container. For example, steganographically encoded information can be attached to the container. Apart from the steganographic coding, other variants of the coding are also conceivable. The coding data may contain, for example, tacking information, information regarding the filling installation, the manufacturer, the customer, the printing ink batch, the print head recognition, the filling date, etc. For example, this information should be incorporated into the first print image information using steganographic means. be integrated so that they can not be recognized by a human observer.

In order to ensure easier and faster detection and readability of the coding data from the print image, based on the print metadata, a selection is made of a local area at which the coding data are to be arranged on the container or in the print image. The local area may be defined either on the surface of the container or in the printed image itself, i. either the printed image or the container itself forms the reference for the position of the coding data to be applied. Frequently, the printed image is attached to the container in such a way that it has a defined relative position to a container feature, for example an embossing. Thus, regardless of the selected reference, the location of the coding data on the container is clearly defined. In particular, a local area, referred to below as the code area, is determined, at which the container wall has a shape which is as constant as possible, for example a curvature which is as constant as possible, and at which a coloration of the printed image which is as constant as possible is given. The first print image information is therefore preferably used to select the local area in order to be able to determine a code area with as constant a coloration or color distribution as possible.

Subsequently, encoded print image information is generated by changing the first print image information based on the encoding data, the change of the first print image information being location-selectively based on the selected local area (code area) in the print image. In this case, the first printed image information is changed, for example, by steganographic means, the encoded print image information being produced by locally changing color values of individual points of the first print image information based on the coding data. In other words, by way of example, the coding data are converted into a dot matrix and this bitmap is included in the first print image information by selectively changing color values of the first print image information at the points of the dot matrix. The information contained in the coding data, for example, by the location of the individual Dots relative to each other shown or coded, ie the actual information is encoded by the position of the points to each other.

Finally, the printing of the container is then based on the coded print image information by means of at least one print head in the direct printing method, i. the steganographically changed first print image information based on the coding data is printed on the container wall as a print image. Thus, the printed image contains a code with the encoding data contained therein. In other words, the code is an integral part of the printed image.

The essential advantage of the method according to the invention is that in a printed image to be attached to the container, further data can be flexibly integrated which are not perceived by the human observer, but can be used for the tracking of delivery routes, for manufacturer tracking or for batch determination. For example, each machine operator can integrate their own coding data into the printed image, whereby the coding data does not change over time (for example manufacturer code) or is variable in time (batch number, filling date, etc.). According to an embodiment, the encoding data is provided as second print image information and the encoded print image information is obtained by combining or superimposing the first and second print image information. For example, the second print image information is contained in an image file, pixel graphic or vector graphic, and the coded print image information is created by merging these two image files. These can be in particular TIF, BMP or JPG files. The merging or combining or overlaying can take place, for example, in a data processing unit which is assigned to the printing device. As a result, a temporal decoupling between the generation of the first print image information, which is produced by a service provider, for example, an advertising agency or a software provider with a long lead time, and he generation of the second print image information generated by the plant operator itself, for example, shortly before Tank printing, reached. In order not to damage the visual appearance of the printed container, the coding data are preferably contained or integrated in the coded print image information such that they are not recognizable without technical aids for the human eye, but are detectable and readable by a read-out device. In addition to avoiding the visual impairment of the printed image is thereby also achieved that any third parties can not read the coding data, as they are not recognizable without technical aids. In order to be able to find the code (in particular steganographic code), also referred to as secure code, more quickly on the printed image, in one exemplary embodiment one or more defined code regions are defined in the printed image on the basis of the print metadata, in which the coding data are contained in coded form , In this case it is possible that the same secure code is contained several times in the printed image. By repeating it can be achieved that even with damage of the printed image, for example, on the transport, the coding data can still be read. Alternatively, it is possible for the coding data to be present exclusively in a single code area in the printed image.

Preferably, the at least one code area is arranged at a defined location relative to a reference mark or a reference position. In particular, the reference mark or the reference position can be an optically easily recognizable region (either feature of the printed image or even a characteristic inherent in the container, for example a convexity or an embossing), which can thus easily be found. The code area can then be arranged, for example, in a defined angle and / or length offset to the reference mark or to the reference position. Thus, the findability of the code area is greatly simplified. According to one embodiment, the reference mark is formed by a print mark or at least part of a bar, matrix or 2D code. It is understood that other print image-specific features can be used as a reference mark. According to one embodiment, the encoding data is included as a dot pattern in the encoded print image information. In other words, the information contained in the coding data is converted into a dot pattern, wherein the information of the coding data is included in the relative position of the individual dots of the dot pattern to each other. Thus, an unauthorized viewer can not readily restore the encoded information even after reading out the dot pattern. The coding data are preferably converted into pixels or pixel groups of a defined color, which partially replace pixels or pixel groups of the first print image information. In other words, a pixel pattern or pixel group pattern is used instead of existing pixels or pixel groups in the first print image information, preferably at a predetermined code area. The color of the pixels or pixel groups is chosen such that they stand out sufficiently from the surrounding pixels.

In an alternative exemplary embodiment, color values of pixels or pixel groups of the first print image information are partially varied based on the coding data. For example, pixels or groups of pixels are changed by a defined color value, so that the pixels or groups of pixels stand out from the surrounding pixels and thus the secure code can be read out.

According to one embodiment, a partial change of pixels or groups of pixels in the area of the bar, matrix or 2D code is effected based on the coding data. In other words, the secure code is integrated into the bar, matrix or 2D code. Typically, these bar, matrix or 2D codes consist partially of homogeneously colored areas (in particular black bars or rectangles) into which the secure code is introduced. This achieves a better retrievability of the secure code.

Preferably, based on the coding data, a partial change of pixels or pixel groups in a defined surface area is effected, wherein the area chenbereich has a size smaller than 5mnn ² , in particular smaller than I mm ² . In particular, the surface area may comprise only a few pixels, for example 10 by 10 pixels. Due to such a small surface area in which the coding data are integrated, a minimal optical impairment of the printed image is achieved.

According to one embodiment, the print metadata also contain information regarding the color of the container to be printed, the size of the applied print image or the color of the filling material. As a result, the integration of the secure code into the printed image and its readability can be further improved.

Preferably, the selection of the local area takes place in such a way that the coding data are arranged in a form homogeneous tank wall area. This can prevent unwanted distortions of the Secure-Code and any resulting problems in recognizing or reading it out.

According to a further embodiment, the invention also relates to a system for printing on containers in the direct printing method comprising at least one printing station with at least one print head and a control unit for controlling the print head. The system continues to include:

an interface adapted to receive print metadata containing at least information regarding the geometry of the container to be printed;

an interface adapted to receive print image information containing data of a print image to be attached to the container;

- An interface which is adapted to receive coding data to be mounted, for example, in steganographically encoded form on the container;

a data processing unit based on the print metadata for selecting a local area to which the encoding data to be arranged in the print image or on the container and is designed to generate coded print image information by changing the first print image information based on the coding data, the change of the first print image information being location-selectively based on the selected local area;

wherein the control unit is adapted to drive the printhead based on the encoded print image information to print the container with a print image containing the encode data. Under container in the context of the invention, all containers are understood, especially bottles, cans, but also pouches, etc.

The expression "essentially" or "approximately" in the sense of the invention means deviations from the exact value by +/- 10%, preferably by +/- 5% and / or deviations in the form of changes that are insignificant for the function.

Further developments, advantages and applications of the invention will become apparent from the following description of exemplary embodiments and from the figures. In this case, all described and / or illustrated features alone or in any combination are fundamentally the subject of the invention, regardless of their summary in the claims or their dependency. Also, the content of the claims is made an integral part of the description.

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

1 shows an example of a printing device in a schematic plan view; 2 is a block diagram of a printing system in an abstracted representation; and 3 shows an example of a flow chart of a method for printing a container with a printed image containing steganographically encoded information.

In Figure 1, the reference numeral 1, a printing device of rotating design for printing bottles or similar containers shown. The printing device 1 has a plurality of printing stations 3, on each of which at least one print head 2 is provided. The printheads are, in particular, digital printheads 2 operating according to the ink-jet or inkjet principle. The printheads 2 each have a multiplicity of nozzles which are provided successively on each printhead 3, for example in a row in the vertical direction, and are individually electrically connected are controllable. The application of the printing ink or printing ink to the nozzles is carried out by appropriate control of electrodes or piezo elements.

In more detail, the printing apparatus 1 in the illustrated embodiment consists of a rotatable around a vertical machine axis MA, preferably continuously circulating rotatably driven rotor 6, at the periphery of a plurality of printing stations 3 are formed. Preferably, each printing station 3 is assigned in each case at least one print head 2, which is moved together with the respective printing station 3. The containers 4 to be printed are fed to the printing stations 3 via a container inlet 7 and subsequently moved together with the printing head 2 assigned to this printing station 3, the printing of the container 4 taking place during this movement. The printed containers 4 are taken from the respective printing station 3 at a container outlet 8.

The printing of the container 4 at the printing stations 3 takes place, for example, line by line by relative movement of the container to the print head 2, in the illustrated embodiment in that each with its container axis in the vertical direction, ie parallel to the axis of rotation of the rotor 6 oriented container 4 during printing is rotated around its container vertical axis controlled. For example, in order to be able to trace or track supply routes of individual containers 4, coding data is applied to the container 4 in addition to the actual printed image. Coding data here are any information that can be applied in encoded form to the container. In particular, coding data may be the filling date or time, an identification number (for example, the container processing unit, the ink lot, the ink tank number, the printhead, the customer, etc.), a security number, or a code number. The coding data are preferably integrated into the printed image in such a way that they are not recognizable to the naked eye. In particular, the printed image is changed steganographically in such a way that the integration of the coding data into the printed image can not be recognized without technical aids. Furthermore, coding is preferably used to integrate the coding data into the printed image. These encoding data integrated into the printed image in coded form are also referred to below as the Secure Code (See Code).

2 shows a system 10 for printing on containers 4, by means of which coding data are integrated into a printed image to be printed on a container 4, and subsequently the printed image containing the coding data can be applied to the container 4 by means of a printing device 1. The system has a data processing unit 11, by means of which the coding data are integrated into the printed image. The data processing unit 11 is provided with first print image information via an interface 12. The first print image information contains data about the print image that is to be attached to the respective container. In particular, the first print image information in the form of an image file or a vector graphic of the data processing unit 1 1 can be made available.

Furthermore, the data processing unit 11 is provided with pressure metadata at an interface 13. The print metadata may in particular contain information that is useful for the preparation and / or execution of the printing process, for example for the placement of the print image, the orientation of the print image, the size of the print image, or the like. are of importance. In particular, the print metadata may include information regarding the geometry or shape, in particular the 3D shape of the container 4. This makes it possible for the secure code to be placed in such a way that it is possible to recognize and read the secure code without difficulty. For example, based on the print metadata, a shape-homogenous surface area can be selected for the placement of the secure code, ie a surface area without beads, grooves, embossings, etc.

Furthermore, the coding data themselves of the processing unit 11 are made available via an interface 14. It has been assumed above that the respective data or information is made available at separate interfaces of the data processing unit. Deviating from this, it is of course also possible for all information or groups of information to be made available at a common interface of the data processing unit 11.

Based on the first print image information, the print metadata and the encoding data, the data processing unit 11 creates encoded print image information. In addition to the first print image information visible to the human eye, this coded print image information also contains the coding data, in particular in coded form. For example, the coding data can be integrated into the first print image information by steganographic editing. Steganographic here means that the coding data are not recognizable integrated with the human eye in the printed image and the customer or buyer of a container is not aware of the integrated image data in the print image.

The selection of the local area in the printed image, at which the integration of the coding data is to take place, can in particular be software-based, wherein the software proposes, for example, one or more local areas where the coding data is advantageously placed in the form of a secure code. For example, the location is selected in a fully automated manner by the data processing unit 11 or semi-automatically, whereby a user or machine operator Operators can select a local area from a variety of proposed local areas. In particular, the three-dimensional shape of the container 4 to be printed is taken into account in order to select the local areas, in order to avoid that the secure code comes to rest on local areas where strong distortions due to indentations or bulges of the container wall are present. Furthermore, the first print image information can also be used to select the local area in order, for example, to ensure that the secure code is arranged at a location in the print image at which the most homogeneous possible color distribution is provided. As a result, the readability of the secure code can be advantageously improved.

The secure code can be formed by arranging a multiplicity of points, hereinafter referred to as secure dots, which are integrated in a suitable manner into the print image or into the first print image information, the combination of first print image information and secure print data. Dots form the encoded print image information. The individual Secure Dots can, for example, be individual pixels or be formed by groups of pixels. The Secure Dots thus form a point cloud or a point grid, wherein the coding of the coding data is done by the relative arrangement of the individual points of the point cloud to each other. The Secure Dots can have a defined color, and pixels or pixel groups of the first print image information can be replaced by these Secure Dots. This is especially the case when the secure code is placed at a point in the print image that has the most homogeneous possible color, which is also different to the color of the Secure Dots. Alternatively, it is possible to integrate secure dots of a secure code into the first print image information by changing color values of pixels or pixel groups of the first print image information based on the coding data, so that a point cloud of locally distributed, varied in their color values Secure -Dots results. Depending on the print metadata or the first print image information, the secure code can also be arranged in the area of a bar code, matrix code or 2D code. This makes it easier to find the secure code and, secondly, such barcodes, matrix codes Codes or 2D codes always have areas with a homogeneous coloring (eg black bars or fields), which are advantageously suitable for arranging a secure code. The secure code can be arranged in particular in a locally very limited area, for example in a surface area that includes a few square millimeters, for example, a surface area less than 5mm ² , in particular less than 2mm ² , more preferably less than 1 mm ² . For example, the area may only cover an area of 10 ^* 10 pixels or 0.7 mm ² . The colors of the individual points of the secure code can be adapted to the background color of the area of the printed image in order to ensure sufficient recognition of the secure code (for example, even after partial fading after UV irradiation), but also to secure it ensure that the secure code is not recognizable as such to the naked eye and therefore is not perceived as visually disturbing.

The first print image information is preferably contained in a first print image file, for example an image file or a vector graphics file. Furthermore, the coding data can be converted into second print image information, for example in the form of an image file or a vector graphics file. The conversion can take place here by means of a coding algorithm which converts the coding data into a secure code, in particular a steganographic code. This steganographic code may for example be contained in the second print image information and already contain the plurality of secure dots. The encoded print image information is obtained by combining or superposing the first and second print image information. In this case, for example, an image processing program can be used, which causes the merging of the print image information to the coded print image information. In the event that the container 4 is provided with a multi-color printing, the first printed image information can also be provided on the basis of a plurality of files, wherein each file is associated, for example, with a defined color and contains information regarding the local application of this color for the production of the printed image. This makes it possible for the generation of the first print image information to be timed. lent independently of the integration of the coding data into the printed image. Thus, for example, the first print image information can for example be generated beforehand, for example by a service provider and the second print image information is generated by the respective bottler or manufacturer of the beverage units themselves and converted to the coded print image information by combining or overlaying the first print image information. Thus, it can also be achieved with reduced expenditure of time and money that continuously changing data, for example production-dependent data, can be applied to the container 4 in coded form.

In a preferred embodiment, the secure code is arranged at a defined location in the printed image and only at a single position in the printed image. In other words, there is no repetition of the secure code at different locations. Alternatively, it is possible to place the secure code in several different places in the printed image and thus to create a redundancy that is necessary, for example, in the event of damage to the printed image for reading out the secure code. The arrangement of the secure code can take place in a defined code area, which has a fixed relative position to a reference point. The reference point may be any container or print image feature that is optically detectable, such as a print mark, a portion of a bar code, bar code or 2D code, embossing, or other optically recognizable mark. For example, the placement of the secure code can be made such that it is arranged offset by a defined distance to a container or print image feature. This achieves an improved findability of the secure code.

3 shows a schematic block diagram of a method for printing a container 4 in direct printing. First, in a first step, the first print image information is generated (S20). This takes place, for example, taking into account print metadata which are at least partially identical to the print metadata used to place the secure code in the print image. For example, the position of the print image on the container 4 and / or the size of the print image are determined before the creation of the first print image information. FER ner can be considered in the choice of creating the first print image information both the color of the container wall or the color of the filling. In addition, the generation of the first print image information can be based on geometry information of the container 4, for example 3D data that reproduces the exact container geometry. Based on this geometry information, for example, the first print image information can be selected such that a distortion of print details by beads or bulges (grooves, depressions, Embossings, etc.) can be largely avoided. As already stated above, the first print image information can also be generated in the form of a plurality of partial print image information, the individual partial print image information indicating the local color application of a defined color.

Hereinafter, in the case where several different ways of coding the coding data, i. for conversion into a secure code, a coding type is selected (S30). For example, according to a first coding type, it is possible to replace image regions or individual pixels of a printed image by secure dots. Alternatively, it would be possible to suitably change only color values of pixels on which the secure dots are situated in terms of location. Furthermore, the choice of the coding type can influence whether the secure code is introduced into the printed image itself or into a bar code, matrix code or 2D code.

Subsequently, in the subsequent step (S40), the determination of the code area, i. the location where the secure code is integrated into the print image. This determination is made in such a way that the secure code is as easily recognizable or retrievable (for example, in a place with a homogeneous color as possible), on the other hand, that the secure code comes to rest on a homogeneously shaped container wall area, i. For example, not in the area of grooves, beads or bulges.

After the determination or the reception of the coding data (S50), the generation of the second print image information (S60) ensues. The second Print image information can also be generated in partial print image information, wherein each partial print image has a certain color (for example cyan, magenta and yellow) and the superposition of the partial print images produces a desired color of the secure code.

After the second print image information is generated, the first and second print image information are combined (S70), resulting in the coded print image information. Here as well, a plurality of first and second partial image data can be combined or superimposed, with the resulting partial image information being used to control the printheads of a particular color after the respective overlay.

Finally, the coded print image information or print image information derived therefrom is transmitted to the respective print heads of the printing apparatus 1 (S80) to perform the container printing based thereon.

The invention has been described above by means of exemplary embodiments. It goes without saying that a large number of changes or modifications are possible without leaving the inventive idea underlying the invention.

LIST OF REFERENCE NUMBERS

1 printing device

2 printhead

3 printing station

4 containers

6 rotor

7 container inlet

8 container outlet

10 printing system

1 1 data processing unit

12 interface

13 interface

14 interface

MA machine axis

Claims

claims

1 . Method for printing a surface of a container (4) with a printed image, comprising the following steps:

- Providing print metadata containing at least information regarding the geometry of the container to be printed (4);

Providing first print image information containing data of a print image to be attached to the container (4);

Providing coding data containing information to be attached to the container (4) in, for example, steganographically encoded form;

Selecting a local area where the encoding data is to be located in the print image or on the container, based on the print metadata;

Generating encoded print image information by modifying the first print image information based on the encoding data, the change of the first print image information being location-selectively based on the selected local area; and

- Printing the container (4) with a print image based on the coded print image information by means of at least one printhead in the direct printing process.

2. The method according to claim 1, characterized in that the coding data are provided as second print image information and that the coded print image information is obtained by combining or superimposing the first and second print image information.

3. The method according to claim 1 or 2, characterized in that the coding data are contained in the encoded print image information such that they are not recognizable without technical aids for the human eye, but are detectable and readable by a read-out device. Method according to one of the preceding claims, characterized in that based on the print metadata one or more defined code areas are defined in the print image, in which the coding data are contained in coded form.

A method according to claim 4, characterized in that the coding data are present exclusively in a single code area in the printed image.

A method according to claim 4 or 5, characterized in that the at least one code area is arranged at a defined location relative to a reference mark or a reference position.

7. The method according to claim 6, characterized in that the reference mark is formed by a print mark or at least part of a bar, matrix or 2D code.

8. The method according to any one of the preceding claims, characterized in that the coding data are included as a dot pattern in the encoded print image information.

9. The method according to any one of the preceding claims, characterized in that the coding data are converted into pixels or pixel groups of a defined color, the pixels or pixel groups of the first print image information partially replace.

10. The method according to any one of the preceding claims 1 to 8, characterized in that based on the coding data color values of pixels or pixel groups of the first print image information are partially varied. 1 1. Method according to one of the preceding claims, characterized in that, based on the coding data, a partial change of pixels or pixel groups in the area of the bar, matrix or 2D code is effected.

2. The method according to any one of the preceding claims, characterized in that based on the coding data, a partial change of pixels or groups of pixels in a defined surface area is effected, wherein the surface area has a size less than 5mm ² , in particular less than 1 mm ² .

3. The method according to any one of the preceding claims, characterized in that the pressure metadata also contain information regarding the color of the container to be printed wall, the size of the applied print image or the color of the filling material.

4. The method according to any one of the preceding claims, characterized in that the selection of the local area is performed such that the coding data are arranged in a form homogeneous container wall area.

A system for printing the surface of containers (4) by direct printing, comprising at least one printing station (3) with at least one print head (2) and a control unit for controlling the print head, the system further comprising:

- an interface (13) adapted to receive print metadata containing at least information regarding the geometry of the container (4) to be printed;

- an interface (12) adapted to receive first print image information containing data of a print image to be attached to the container (4);

- At least one interface (14) which is adapted to receive coding data to be mounted, for example, in steganographically encoded form on the container (4);

a data processing unit (11) to be arranged based on the print metadata for selecting a local area where the encoding data is to be placed in the print image and the container, respectively for generating coded print image information by modifying the first print image information based on the coded data, the change of the first print image information and / or production of the coded print image information being carried out in a location-selective manner based on the selected local area;

wherein the control unit is adapted to drive the printhead (2) based on the encoded print image information to print the container (4) with a print image containing the encode data.