DE102005037497A1 - Method for individually characterizing each copy on a printed sheet comprises applying a printing ink or coating on the sheet using a printing device connected to a laser device with a thermosensitive ink - Google Patents

Abstract

Method for individually characterizing each copy (2) on a printed sheet (1) comprises applying a printing ink or coating on the sheet using a printing device connected to a laser device with a thermosensitive ink. Independent claims are also included for the following: (1) Device for carrying out the above method; and (2) Method for operating an image inspection system for quality assurance of an offset printing machine. Preferred Features: The ink is applied using an inkjet printing machine or a spraying device. The ink is transparent when not illuminated.

Description

These The invention relates to a method of applying individual Codes on substrates during the printing run in a printing press, preferably sheet-fed offset printing press, and a method of generating such coding. It also includes the invention also provides a system for quality control of printed picture elements.

In the US 1,681,716 An apparatus and method for individualized coding of packages is described. As possible encodings for the purposes of this invention, references to the packer, the date of packaging or other similar information are provided. The printed information should be uncommon and meaningless at first glance. This is achieved in the sense of the invention by the combination of different bar codes. The desire to provide packaging with individualized codes has therefore been known since at least 1928.

There are thermal papers or thermosensitive papers known, as used for example in ticket printers. A subset of these papers consists of a carrier material, for example paper or cardboard, and a heat-sensitive recording layer located thereon. This heat-sensitive recording layer is usually colorless or consists of only weakly colored dye precursors. Upon heating with a thermal head or a laser beam, the heat-sensitive layer reacts immediately and a color change occurs in the heated area swept by the thermal head or the laser. The exposed or heated area becomes readable. Generic representatives of such thermal papers are in the DE 36 01 645 A1 and in the DE 40 10 721 A1 to find.

It is known to use laser systems in printing machines, also sheet-fed presses, for the drying or curing of ink layers. A generic representative of such a laser drying system is inter alia in the EP 1466732 A2 disclosed.

From the DE 3425086 For example, a method is known in which an individualized print is produced within a printing press in which a conventional printing ink, as can also occur in the print images, is printed and the marking is carried out by removing the preprinted printing ink by applying energy. As a source of energy in the sense of this invention modulated laser light or ultrasound is provided.

In addition to the destructive laser ablation processes in which parts of the ink layer are removed or evaporated, non-destructive methods are known. Characteristic of these methods is that a coating or a color layer is applied to the substrate, which is usually colorless and contains a activatable by the laser dye, which shows a color change under laser action. Generic representatives of such coatings or printing inks are among others from the EP 0 993 964 A2 or EP 0 600 441 A1 known. Advantage of the use of such coatings or printing inks is that the laser energy to be used can be significantly lower than in the destructive method, as in the DE 3425086 to be discribed. In addition, these color change layers after labeling with the laser very high contrasts, which make an evaluation after printing or during printing by a suitable sensor, such as a bar code reader, very easy.

There is often the claim to provide each package with an individual number, barcode or other identification that allows later identification of the product. These procedures are used to stem the gray market and counterfeiting. Usually these codes are applied in packaging lines or by special equipment on the packaging. A generic representative of such labeling methods is in the US 4757187 disclosed.

at Sheet-fed offset printing machine is judged by the print quality Draw a sample sheet, which is then placed on an extra clamp and is recorded and evaluated visually and / or metrologically. A such quality assessment However, this is just a sample, so a slow change the quality in certain circumstances only after a big one Period is noticed, then a corresponding amount of waste paper accrues. Also test sheets can lead to mature quality defects, for example caused by oil spills, Slugs or scratches, difficult to grasp. Accordingly is not to prevent a corresponding amount of unnoticed waste in the Display lands, which then before further processing by appropriate Work steps must be sorted out again.

Permanent quality monitoring is possible with printing machines if, in particular after the last printing unit, an image recording device in the form of a camera together with image processing is arranged. Such image inspection systems are for example from EP 1 190 855 A1 and of the EP 0 884 182 B1 known. The image data obtained by the image recording device are compared on a pixel-by-pixel basis with predetermined nominal values, whereupon, in the event of deviations from nominal values, either warnings are issued or corrective action is taken on the printing process.

With The known image inspection systems, it is also possible, the Sheet according to the print quality on different stacks store. So waste is automatically sorted out and further processing not supplied. Straight sheets printed in multiples, e.g. labels for bottles, Folding boxes, one would faulty picture place in a use the whole sheet to waste paper do. The remaining error-free benefits that could be further processed would be included such a rating also committee. A typical sheet with several benefits is shown.

This prevents the DE 200 10 920 U1 to determine from the image signals of the image pickup device, the error-free benefits and therefore set the print edition to be printed on the basis of the error-free printed benefits. In further processing, for example when punching out the labels or folding boxes, then the error-free benefits must be recognized in turn by appropriate devices.

From the DE 39 38 138 C2 a device for quality assurance of the print run on a sheet-fed printing machine is known, in which the sample sample sheet resulting in the area are provided with a mark. These sheets are then marked after printing on the display by means of a Streifeninserters in the stack, in addition sounds an optical and / or acoustic signal, so that these sheets can be removed by hand. A report is drawn up about the distribution of the sample, so that the quality assurance is documented by the edition print.

From the EP 0 612 042 B1 For example, a scanning station in a printing machine is known which generates data describing the printed images and analyzes these data based on given criteria. A marking station is coupled with the analysis station, which affixes a nullification notice to those documents or benefits in which the data analysis has determined that they do not meet the specified criteria. The individual documents are marked by a print head, eg an inkjet or impact printer.

Embodiments for a color control within a printing press are in the EP 0749 8833 A2 and the EP 0 798 117 A2 described. The DE 43 21 177 A describes a co-solution of defect detection and color measurement within a printing machine. In addition to the camera-based solutions for inline color measurement, solutions based on densitometric or spectrophotometric probes are also known. An assignment of colorimetric and / or densitometric tolerance ranges for individual picture elements is inter alia from EP 0 527 285 A2 known.

The EP 1 454 746 A1 describes an image processing system for a printing press, in which the image processing device is arranged downstream of a printing device by which markings are generated at recognized as defective image locations. As printing units for marking erroneous image locations or benefits are inkjet printers; Laser printers, numbering devices that produce either a visible or invisible mark on the substrate. It can be arranged according to the image division along a traverse multiple printing units.

task The invention is within the print run by a printing press a fast, inexpensive and to find secure identification method and apparatus that enables an individualized labeling of printed products.

Is solved This object is achieved by the characterizing features of claim 1.

further developments The invention will become apparent from the dependent claims 2 to 7.

A Another object of the invention is a quality control system by means of image analysis using individually printed codes. Is solved This object is achieved by the characterizing features of claim 8.

further developments The invention results from the subclaims 9 to 18.

Of Another is a procedure for the traceability of products described in claim 19.

in the The invention will be described in more detail below with reference to an exemplary embodiment. The associated Drawings show in detail

1 a printed sheet with several benefits,

2 a printing unit and boom with image processing device, and

3 a printing machine with boom and image processing device

Becomes in the case of a trademark protection program waives a first-opening characteristic, which the authenticity guaranteed by the content of the packaging, it is of enormous importance that the complete distribution chain of the product right up to the point of sale is checked to make sure that the original goods too arrives at the intended location. Securing the entire distribution chain, from the production site to the various points of sale, represents for a brand manufacturer in terms of brand protection a crucial Role, because the trend is always manufacturing many products more in less expensive Relocating areas like Eastern Europe, new problems arise for him.

Though he saves by the cheaper production money for the production costs, it falls to him but heavier, the overview of your own Production, logistics and distribution channels. Become produced more copies of the packaging provided with safety elements as intended, for example in an additional night shift, from the manufacturer does not know anything the entire effort of product protection is quickly meaningless.

provides The manufacturer now ensures that in its production everything goes as planned runs and well-secured products are on the way to the point of sale, must Even the long delivery route can be monitored there to reduce the risk ruled out that fake Products inserted in the chain and against the original products be replaced. in principle Every interface on the delivery route of a product carries a risk potential, at the goods disappear or can be exchanged. This includes everyone Turnover points, as well as warehouses (manufacturer, central, customs, distribution warehouse) and Transport service providers (water, land, air). The fewer interfaces There is, the easier the control. The control of the supply chain means logistical effort that goes well beyond the brand protection goes, but supports it can be.

Next Trademark protection plays the traceability also in the food sector a big role. Owns the packaging an individual code, the code can be read at any time and connect with more information. With appropriate shortcut The data can be at any time the manufacturer of the packaging, the filling time and filling location be determined. Furthermore can the product during of the entire product life cycle through its individual coding be followed. This will meet the high requirements of food law in the best way possible.

One typical representative of such "track-and-trace" technologies for Product tracking is RFID (radio frequency identification) technology, which allows the storage of individual data on a chip. Typically, such RFID transponders Applied on a label that is usually called a smart label named, which is glued on the packaging. This technology has already been widely used in transport packaging or Enforced packaging, but is in consumer packaging in usually too expensive. This is how a typical smart label costs between 0.40 cents and 1 euro, so these costs for most consumer packaging, e.g. in the food sector, are too high.

Out The packaging industry knows of procedures, individual packaging as a single piece or as part of a printed sheet with several benefits by means of a Mark ink jet device. The marker can be a number, a readable or coded text or a barcode of any design be.

The EP 1 454 746 A1 describes an image processing system for a printing press, in which the image processing device is arranged downstream of a printing device by which markings are generated at recognized as defective image locations. As printing units for marking erroneous image locations or benefits are inkjet printers; Laser printers, numbering devices that produce either a visible or invisible mark on the substrate. It can be arranged according to the image division along a traverse multiple printing units.

In the in the US 4,757,187 disclosed method is provided by an authorized body, an identification set that is known only to this body. These markings are then printed on the packaging and the markings allow the manufacturer of the packaging, the date of manufacture and the distribution channel to be tracked at any later time. This labeling makes the packaging an individual. The disadvantage of these methods is that they are applied either by a separate inkjet printing machine after printing or by an inkjet printing device in a packaging line. As a result, there is always the danger that more prints that are produced in the printing press, used for illicit purposes or gray market activities. Are the printed products already in the printing press clearly marked, such abuse is less easily possible.

Another advantage of the individual identification within a printing press is that the applied code can be read out by a suitable sensor system in a further processing machine. If a corresponding coding, for example a text, a number or a barcode, is applied to a single image during the printing run and then an image recording device with coupled image evaluation unit, the printed sheet during the printing process with regard to the occurrence of defect images, such as defects in the image or deviations from other predetermined tolerance windows, evaluated, at the same time the information content of the coding for the erroneous benefit can be determined by image analysis. The code should be on every use ( 2 ) on the printed sheet ( 1 ) are applied. The device for applying the code may be located in the feeder ( 10 ) of a printing press, in the installation of a printing press, in the area of the 9 ) and in the arch, in front of the printing nip or sheet exit, after the printing nip of a printing unit ( 12 ) are located. However, the code should be read before passing the measuring range of the image acquisition system ( 3 ) be applied to the sheet. If this information information content of the individual marking and error image, such as error outside tolerance or no error, connected to the information value of the individual coding and then passed this data via data line, data storage or in any other suitable way to appropriate data processing equipment to further processing machines, so later a discharge device are controlled, which ejects the erroneous benefits from the production flow. What is needed for this approach is only suitable sensor technology on the further processing machine, which makes it possible to detect the printed, individual code. This could, for example, be a barcode reader for a printed barcode.

One alternative approach could be that the printed code associated with a benefit later in terms of data, with an error that also occurred Benefit is assigned later linked by data technology and this data will be used to control the ejector. In this case, the individually printed code does not have to be from the image analysis unit are evaluated, but the linkage of the Error location and the individual code is done by data technology on the Assignment to the individual benefit or coordinates on the sheet.

In demarcation to the EP 1 454 746 A1 Not only is the erroneous benefit marked, but each benefit on the print sheet contains an individual code that later makes it possible to uniquely identify the benefit. This code is primarily used to track products, but at the same time, when using a suitable quality control system, it is used to identify faulty products. The EP 1 454 746 A1 requires that marking be carried out after the image analysis has been carried out, since first the location of the defect and thus the location of the marking must be determined. This means, due to the required computing time, that the marking device often has to be located in the delivery of a sheet-fed printing press, since an image analysis device is typically located in the last printing unit or in the coating unit of a sheet-fed printing machine, since the entire print is to be evaluated. In the delivery of a sheet-fed printing machine, such a marking device is difficult to realize because of the circulating delivery gripper systems. Inkjet printers, for example, are difficult to deploy because of the high distance between the printhead and substrate and the turbulence created by dryer units and rotary delivery gripper systems.

By the decoupling of the imprint of the individual code from the evaluation the bow may already be on the delivery pile if the Evaluation is still running, i.e. With this method, the time pressure can also be clear defused become. this could For example, in the pictures or drawing files that make up the image analysis system has recognized as faulty passed on to a second evaluation unit which makes the mapping fault to code. This would be the image analysis unit entrusted with the task of performing the complex error analysis, they are extremely time critical is while the downstream evaluation algorithms only in case of error on one run second system. This will make the image analysis system of the elaborate structural analysis, as required for code recognition are relieved.

1

sheet

2

Use on the sheet

3

camera for image recording

4

Image processing system

5

plate cylinder of the printing unit

6

lighting device

7

Impression cylinder

8th

transferters

9

feed drum

10

investor with feeder pile

11

rubber cylinder

12

printing unit with inking unit, rubber, plate and impression cylinder

Claims (20)

Method of individual labeling of each benefit ( 2 ) on a printed sheet ( 1 ) by means of a laser device during the printing run in a sheet-fed press, preferably sheet-fed offset printing machine, with a visually or machine-readable unique coding, characterized in that a printing ink or coating is applied to the printing sheet with a printing device, wherein the printing device in the sheet running direction of the printing machine of the laser device is arranged upstream and in that the printing ink or coating applied by the printing device is a thermosensitive printing ink or coating which exhibits a color change under the action of a laser beam, Apparatus for carrying out the method according to claim 1, characterized in that it is in the device for Application of the thermosensitive ink to an offset printing unit These, Apparatus for carrying out the method according to claim 1, characterized in that it is in the device for Application of the thermosensitive ink to a flexographic printing unit or coating plant, Apparatus for carrying out the method according to claim 1, characterized in that it is in the device for Application of the thermosensitive ink to an ink jet device is. Apparatus for carrying out the method according to claim 1, characterized in that it is in the device for Application of the thermosensitive ink to a spray device is. Printing ink for carrying out the method according to claim 1, characterized in that the printing ink in the unexposed Condition transparent or approximate is transparent. Printing ink for carrying out the method according to claim 1, characterized in that the printing ink in the unexposed Condition has a uniform color. Method for operating an image inspection system for quality assurance for a printing press, in particular sheet-fed offset printing press, in which the printing material is processed by an image recording device ( 3 ) and the signals obtained in a downstream image processing ( 4 ), characterized in that each benefit ( 2 ) of the print sheet ( 1 ) receives in the sheet running direction of the printing machine before passing through the image processing device an individual code by a printing device or by a laser device and in case of error within a benefit ( 2 ) This code or derived therefrom unique identifier in digital form and passed to a post-processing device, such as a Faltschachtelklebemaschine in digital form, and there in the further processing device after punching or Schnei the sheet of the individual code of the isolated benefits detected by a suitable sensor and compared in an evaluation of the detected code with the existing data of the erroneous benefits and in the case of conformity of the erroneous benefits from the production process by a suitable device within the further processing device is discharged. Method according to claim 8, characterized in that that the individual codes on the sheet in the image analysis be excluded in the printing machine from the error consideration. A method according to claim 8, characterized in that the individual codes together with the printed images in the evaluation unit ( 4 ) of the image analysis system can be evaluated jointly or sequentially by suitable software. Method according to Claim 8, characterized in that, in the event of an error, the affected image detail, which must comprise at least the region of the associated individual code, is displayed on one of the image analysis evaluation units ( 4 ) is passed to the switched evaluation unit and there the analysis of the code by means of a suitable software. Method according to Claim 8, characterized in that, in the event of an error, the coordinates of the error are determined by the evaluation unit of the image analysis system ( 4 ) is passed on to an additional evaluation unit, there the associated benefits ( 2 ) is identified on the basis of the coordinates and then by means of a combination of printed sheets and coordinates, the printed code is identified by access to the data of the printing device and combined with the error feature. Apparatus for carrying out the method according to claim 8, characterized in that it is in the printing device to imprint the individual codes of each benefit is an ink jet device. Apparatus for carrying out the method according to claim 8, characterized in that it is a Laservorrich in the printing device is acting. Method for carrying out according to claim 1 and 8, characterized in that a conventional printing ink pre-printed and this is partial to the creation of the individual coding is at least partially ablated by the laser beam. Method for carrying out according to claim 1 and 8, characterized in that the individual coding by carbonization (discoloration by heat) of the printing material surface is achieved. Method for carrying out according to claim 1 and 8, characterized in that the marking method according to claim 1 of this patent application is used. Method according to claims 8-16, characterized by that the individual code is a readable sequence of Characters and numbers act. Method according to claims 8-16, characterized by that the individual code is a barcode, a 2D barcode or other machine-evaluable code. Method for tracking printed products characterized by the fact that the data in the printing presses Printed individual codes in digital form to each or the last process step in the chain of print product production be passed on and in each process step or in the last Production step the data to the erroneous or missing Encodings are cleaned up, so that in the end in digital form data the individual codes of the printed products, which are for Delivery to the customer. The file can then be sent to the Be passed on to customers. So theoretically at any point the product life cycle, if necessary, ensures traceability become.