Delivery and method for marking sheets in the delivery of a sheet-processing machine

Abstract

Delivery for a sheet processing machine, with a conveyor system for conveying sheets (1) to a delivery sheet stack (2) and for releasing the sheets (1) in the delivery area, wherein the released falling sheets (1) form the delivery sheet stack (2) in the delivery area and with a marking device (3) for marking several sheets (1) forming the delivery sheet stack (2), wherein the marking device (3) is arranged next to the delivery sheet stack (2) in such a way that a laser beam locally colors or removes and / or ablates sheet material by laser action on several sheets (1) on the front surface and / or at least one side surface of the delivery sheet stack (2), or that an inkjet inks several sheets (1) at least locally on the front surface and / or at least one side surface of the delivery sheet stack (2) and wherein the local marking applies order- and / or stack-related data in the form of alphanumeric characters, codes, one- or multi-dimensional barcodes and / or graphics to the delivery sheet stack (2).

Description

The invention relates to a delivery and a method for identifying sheets in the delivery of a sheet-processing machine.So-called pallet magazines are known which contain data relating to the printing material stack which leaves a sheet-fed printing press, for example. The pallet ticket is often filled by hand or printed on commercially available printers. It generally contains data on the print job, such as, for example, job name, customer name, product name, number of sheets in the respective stack and in the total job, and stack number. The pallet running notes are glued to the delivery sheet stack or inserted into it. There is a risk that the pallet ticket will be lost or replaced.Printing machines with integrated quality inspection systems are also known. In order not to process the sheets identified as defective in the following process stages (further processing), these must be able to be marked and separated out. The marking is generally carried out by paper strips or b) shot in by means of warp-gun shooting devices by local colorings by means of marking ink or laser action on the sheet top side and can thus be lost in case a) or is not necessarily recognizable from the outside in the stack in case b).DE 29 02 261 A1 discloses a method and an apparatus for marking sheets, wherein after the preselected number of stacked sheets has been reached, a stamping device is actuated, which provides the upper part of the ream with a stamp imprint on the top side of the sheet stack.DE 10 2005 037 498 A1 discloses a quality control system for a printing press, downstream of which one or more laser device / s are connected, which, in the event of a fault or when a predetermined tolerance value or tolerance window is exceeded, ablates a portion of the pre-printed printing ink in the printed image and / or removes it by evaporation or leads to a color change by the laser beam in the case of a pre-printed special color. A disadvantage of this solution is that the laser acts on the sheets from above and a marking on the deposited delivery sheet stack is therefore not detectable or visible.DE 10 2005 045 498 A1 discloses a method for identifying or treating at least one defective sheet, which proposes a differently configured identification, which can be perceived outside the stack, on the stack by a stripe shooting device. The strips can differ from one another, for example, in their color, in their material and / or in their marking. A disadvantage of this solution is that the strips can be lost. If, however, stripes are lost, erroneous information is immediately obtained, since the operator relies on the information embodied by the ridges. However, incorrect information can lead to an intolerably incorrect further processing and / or to time-consuming checks.DE 10 2006 004 569 A1 discloses a method and a device for marking printing substrate sheets, which proposes a marking element on one of the sheet side edges during the conveying movement of the printing substrate sheets. A disadvantage of this solution is that the side edge of the uppermost sheet is colored before it is deposited on the stack, where the latter is still unstable. During the arc, the information can be displaced or lost. Special codes cannot be economically realized during the inking.DE 10 2007 036 326 A1 discloses a device and a method for marking and screening faulty printed images, wherein marking liquid can be applied by a spray head to the printing substrate surface in a pre-selectable manner that can be adapted to existing screening possibilities for faulty printed images for marking the faulty printing substrate or faulty printed image. A disadvantage of this solution is that the ink acts on the individual sheet from above or below, so that the marking in the stack is no longer visible.DE 10 2011 076 067 A1 likewise shows marking sheets in front of a sheet brake device by means of a marking device. The marking device can be an ink-jet printing device.DE 10 2011 010 719 A1 discloses a method for marking sheets in a sheet-fed printing press, wherein printed sheets are provided with a permanent marking that is visible on the end side after being deposited in the delivery stack with the aid of a laser beam during the passage through the printing press. A disadvantage of this solution is that the laser has to strike the individual sheet side edge, which leads to high outlay and complicated adjustment work in the case of very thin printing materials. In this case, only the end faces can be marked, which is not visible on all configurations of printing machines.The object of the invention is therefore to further improve the labeling process of sheets in the delivery of a sheet-processing machine. The purpose of the invention is in particular to develop an apparatus and a method which make it possible to apply labels and / or texts to at least one side of a delivery sheet stack in such a way that they are visible from the outside and cannot be lost and / or interchanged.According to the invention, the object is achieved by a device having the features of the independent device claim and a method having the features of the independent method claim. Advantageous embodiments are evident from the dependent claims, the description and the drawing.The invention has the advantage that the labeling process of sheets in the delivery of a sheet-processing machine is further improved.Application of order- and / or stack-related information, which is otherwise transmitted by means of pallet running notes into the further processing, is preferably carried out directly on the printing material in the delivery sheet stack. Advantageously, the safety of the logistic sequences, for example in a printing shop, is increased by an indiscernible application of information which otherwise takes place by means of pallet running notes. In addition, an otherwise necessary printer for dispensing the pallet tickets can be saved. In the case of a combination with a quality inspection system, it is possible to detect the position of the defective sheets on the stack, which in particular facilitates manual sorting processes.Since the stack in the delivery of a sheet-fed printing press is lowered with an increasing stack height, it is also possible to dispense with a height adjustment of the identification device. The use of a laser, for example, makes it possible to mark the stack from a greater distance than with ink jet printers. In some circumstances, if the scanning range is sufficient, a laser can even be fixedly mounted and can compensate for the format-specific distances from the stack. Particularly preferably, the marking or marking is applicable for printed products in which the marked, for example colored, edge of the sheets affected by the marking is removed during the further processing during punching or cutting and thus does not reach the final customer. The identification device can be displaced for the variable identification of different stack sides or a plurality of identification devices controlled as required can be arranged.The most varied graphic elements, in particular identifications / texts / geometric elements / codes of all kinds, can be imaged by the identification device. The desired data, which are contained on the so-called pallet running notes, for example, can be colored or printed / ablated particularly advantageously on the stack outer side, i.e. overlapping over several sheets (edges), by means of ink jet printing or lasers.Particularly advantageously, the identification device can be arranged on any desired stack side, so that an identification of the delivery stack can take place independently of the stack extension direction. In particular, an end face of the delivery stack, which is formed by sheet front edges stacked one above the other, can be characterized. Additionally or alternatively, the opposite stacking surface, which is formed by sheet trailing edges stacked one above the other, can also be marked. Advantageously, the marking of a respective sheet does not take place until it has touched the stack surface or deposited and thus forms the delivery sheet stack.The invention is to be explained below by way of example. The accompanying drawing schematically represents: FIG. 1 : Delivery of a sheet-processing machine with identification device.The single FIG. 1 shows an embodiment of a sheet-processing machine, in particular a sheet-fed printing press, here especially a sheet-fed offset rotary printing press, preferably of aggregate and series construction. The machine contains at least two successive works which can be designed, for example, as plant, printing, lacquer, drying and / or finishing works. Furthermore, the machine can have a feeder for sheet feeding. The printing machine can preferably be equipped with a reversing device and can thus be operated in a switchable manner between the modes of perfecting and perfecting. Here, only a last printing and varnishing unit of the machine immediately before the delivery is shown by way of example.The delivery unit contains a sheet conveying system which transports the sheets 1 printed, painted, processed, etc. in the printing machine to a delivery sheet stack 2. This sheet conveying system is preferably designed as a chain conveying system with two delivery chains, each guided laterally on the frame of the delivery device, between which delivery chains gripper carriages, not shown, are arranged. The gripper carriages have sheet fixing systems with which the sheets 1 to be transported are gripped at the front edge. The delivery chains guide the gripper carriages on a gripper carriage path in the sheet running direction BLR as far as over the delivery sheet stack 2, where the gripper carriages release the sheets 1 for deposition. On the sheet conveying path to the delivery sheet stack 2, at least one mechanical sheet guiding element, preferably one or more sheet guiding plates, is arranged in the delivery below the sheet conveying plane, which guiding element guides the sheets 1 on the path to the delivery sheet stack 2. The sheet guide plate has an at least approximately closed surface for the sliding or floating guiding of the sheets 1. The sheet metal guide plate can be provided with an ink-repellent coating. Furthermore, nozzle openings for the pneumatic guidance of the sheets 1 can be assigned to the sheet guiding element, in particular to the sheet guiding plate. An air cushion can be formed between the sheet guiding element, in particular the sheet guiding plate, and the sheets 1 transported above it, in particular in the perfecting mode.In the delivery position, the delivery sheet stack 2 is preceded in the sheet running direction BLR by a sheet brake, not shown in detail, which takes over the sheets 1 to be deposited by the gripper carriages and, after their release, delays them from machine speed to depositing speed. After the delay by the sheet brake, the released falling sheets 1 forming the delivery sheet stack 2 in the delivery region are aligned with front, rear and / or side edge stops, not shown, and deposited cleanly. The delivery sheet stack 2 is preferably lowered by a stack lifting drive, not shown, during the sheet depositing process in such a way that the stack surface forms an at least approximately constant depositing level for the coming sheets 1. The sheet brake contains at least two brake stations which are arranged so as to be displaceable, in particular displaceable, axially, that is to say transversely to the sheet running direction BLR. However, it is also possible to use a plurality of such brake stations, for example at least three or exactly three, four, five or also more brake stations depending on the format. The braking stations are preferably placed on a respective lateral sheet edge, which is generally unprinted, on print-free corridors and / or on sufficiently dried ink areas. The displacement can be carried out manually or preferably by motor. For example, a drive, in particular via a spindle drive, can displace the brake stations. Braking stations not required can be deactivated and / or displaced out of the range of the sheet format.In the delivery of the machine, an identification device 3 is arranged in such a way that it can identify at least one side surface and / or an end surface of the delivery sheet stack 2. The marking comprises a plurality of sheets 1, wherein individual regions or even an entire length and / or width of a sheet 1 can be marked. In this case, an identification device 3 can be provided or a plurality of identification devices 3 are assigned to one stack side or else to a plurality of stack sides. According to one variant, an identification laser can be arranged next to the delivery sheet stack 2 in such a way that it locally colors the delivery sheet stack 2 by laser action on the sheet 1 or removes or ablates sheet material. In a further variant, an ink jet printing device is arranged next to the delivery sheet stack 2 in such a way that it locally inks the delivery sheet stack 2 onto the sheet 1 by means of an ink, wherein in particular ink can be used which is visible under normal light or which is visible under ultraviolet (UV) or infrared (IR) light.The identification device 3 can be mechanically and / or electrically connected to the display or to the machine, for example, or can also be arranged in a self-supporting manner next to the machine, wherein the identification device 3 can operate independently or is electrically connected to the machine. The identification device 3 could be designed to be height-adjustable, wherein a height adjustment can be carried out automatically or manually. Further preferably, the identification device 3 can be adjusted to the sheet format in the width and / or length direction, wherein this adjustment can be carried out automatically or manually. For example, the identification device 3 for adjustment can be mechanically connected to an existing device for format adjustment, in particular to the sheet brake, e.g. for adjustment in the sheet running direction BLR, or to a side wheel pusher, e.g. for adjustment transversely to the sheet running direction BLR. Furthermore, it can be provided to assign to the machine, in particular to the delivery, a suction device for the vapors generated during the labeling. It is particularly preferred to use the suction device when using an identification laser. The suction device can also be integrated into the machine, in particular the printing machine.A marking device 3 is used to locally mark or mark a plurality of sheets 1. Here, the identification is made on at least one stack side or stack surface on the sheet 1 lying firmly in the delivery sheet stack 2. The marking thus takes place only after the sheet 1 has been deposited on the delivery stack surface, i.e. when the dropping process for the relevant sheet 1 is completed. Slipping of the sheet 1 relative to the one immediately beneath it is thus largely ruled out. Preferably, sheets 1 can also be marked which are located firmly in the delivery sheet stack 2 between further sheets 1. The marking can apply order- and / or stack-related data in the form of alphanumeric characters, codings, one- or multi-dimensional bar codes and / or graphics to the stack by local coloring. The data can contain, among other things, information about the order name, customer name, product name, number of sheets in the respective stack and in the total order and stack number.Furthermore, a machine, in particular a sheet-fed printing press, can be assigned a control device 4 which interacts with a quality control system and which actuates the at least one identification device 3. Particularly preferably, the machine can be equipped with an inline quality control system, for example an inline inspection system 5, which, in combination with the control device 4, makes a distinction between crop sheets and sheets 1 evaluated as defective. To distinguish the sheets 1 evaluated, they can be colored, ablated or ablated locally or over their full width or length at one or more of their edges in the display by the marking device 3.An inline inspection system 5 is preferably arranged downstream of the last printing nip of the machine. Preferably, the sheets 1 are inspected while they are held by a cylinder, in particular a printing cylinder 6. In the case of two-sided printing in the perfecting mode, an additional inspection device is required for the rear side of the sheet, which inspection device is assigned to a cylinder in particular downstream of the turning device or which can also be arranged below a downstream transfer drum or below the delivery chains. The inspection devices, in particular the inline inspection device 5 assigned to the last printing cylinder 6, are connected to the control device 4 in such a way that printed image information obtained can be evaluated or evaluated, for example also via users. The control device 4 comprises an evaluation unit for this purpose. The control device 4 can also be part of the machine control or can be integrated therein.The control device 4 can further be connected to a higher-order production planning system 7 or a product control system (PPS) or an operating data acquisition (BDE). Data for the identification device 3 can thus be supplied to the control device 4 from the control station of the printing machine (possibly via an interface to a superordinate PPS or BDE system) or from an inline and / or offline quality control system. The data obtained by the control device 4 (e.g. sheet no. of the error sheets, number of error sheets or good sheets) can subsequently be applied by the identification device 3 in the form of alphanumeric characters, codes, one- or multi-dimensional bar codes and / or graphics to the delivery sheet stack 2.The delivery sheet stack 2 which is marked at least locally by the marking device 3 is generally subjected to further processing. During the further processing, the marked or the unlabeled sheets 1 can subsequently be sorted out manually or automatically identified and discharged.To identify fault sheets which have been identified by the identification device 3, for example, it is possible, in particular in automated further processing, to use an industrial image processing (IBV) system which counts the sheets 1 for example and / or determines their position in the delivery sheet stack 2. Such an IBV system can be connected via a data interface to the machine control station, the control device 4, the further processing machine and / or the quality control system.The monitoring of the markings applied to at least one stacking side or stacking surface by the IBV system can be carried out automatically. The markings or markings are illuminated permanently or in flash operation by means of illuminations, preferably LEDs, in suitable wavelengths, for example visible light, IR or UV light. The markings are detected by means of one or more cameras, in particular with matrix-shaped sensors, preferably CCD or CMOS, and are subsequently evaluated with methods of image processing, preferably pattern matching. Gray-scale-based systems are preferably sufficient as cameras. The image processing or preprocessing can be carried out in the camera (smart camera) or in an external evaluation unit. The sheets 1 can be counted in a technically demanding manner within the image processing or preferably by means of an external sensor, for example a light barrier, light scanner, ultrasonic sensor, capacitive sensor.List of reference characters1 Sheet 2 Delivery sheet stack 3 Identification device 4 Controller 5 Inline inspection system 6 Printing cylinder 7 Production planning system BLR Sheet running direction

Claims

Delivery for a sheet processing machine, having a conveying system for conveying sheets (1) to a delivery sheet stack (2) and for releasing the sheets (1) in the delivery region, wherein the released falling sheets (1) form the delivery sheet stack (2) in the delivery region and having an identifying device (3) for identifying a plurality of sheets (1) forming the delivery sheet stack (2), wherein the identifying device (3) is arranged next to the delivery sheet stack (2) in such a way, a laser beam, by laser action on a plurality of sheets (1) on the end face and / or at least one side face of the delivery sheet stack (2), locally coloring the latter or removing and / or ablating sheet material, or an ink jet at least locally coloring a plurality of sheets (1) on the end face and / or at least one side face of the delivery sheet stack (2), and wherein the local identification applies application-related and / or stack-related data in the form of alphanumeric characters, codings, one- or multi-dimensional bar codes and / or graphics to the delivery sheet stack (2).Display according to Claim 1, characterized in that the marking device (3) uses visible ink or ink which is visible under UV or IR light.Display according to claim 1 or 2, characterised in that the identification device (3) is arranged so as to be adjustable and / or adjustable in height in the width and / or length direction to the sheet format.Display according to Claim 1, 2 or 3, characterized in that the identification device (3) can be controlled by a control device (4) which interacts with a quality control system (5).Display according to claim 1, 2, 3 or 4, characterised in that the display is assigned a suction device for the vapours produced during operation of the identification device (3).Method for identifying sheets (1) in the delivery of a sheet-processing machine, wherein sheets (1) are conveyed to a delivery sheet stack (2) by means of a conveying system and are released in the delivery region, wherein the released falling sheets (1) form the delivery sheet stack (2) in the delivery region, wherein a plurality of sheets (1) forming the delivery sheet stack (2) are identified by means of an identifying device (3), wherein the identification of a sheet (1) does not take place until it touches the stack surface and thus forms the delivery sheet stack (2), wherein the identifying device (3) applies data in the form of alphanumeric characters, codes, one- or multi-dimensional bar codes and / or graphics to the delivery sheet stack (2), and wherein the local identification applies sheet numbers, The number of sheets in the stack can be selected from the group consisting of sheet numbers of sheets and / or missheets, number of sheets and / or missheets and / or order- and / or stack-related data.Method according to Claim 6, characterized in that the identification device (3) is actuated by a control device (4) which interacts with an inline quality control system (5), wherein, in order to distinguish sheets of material and sheets (1) which have been assessed as defective, said sheets are coloured, ablated and / or ablated locally at one or more edges or over the full length and / or width.

Images