DE19743804A1 - Large format printing using ink-jet printer - Google Patents

Abstract

The printer, for simultaneous line printing on large format web materials, has a number of modular ink jet printer heads (10), at right angles to the direction of material movement through the printer. They overlap in lines, in at least two stationary lines. Their operation is controlled electronically, to form a printed image along the lines. The printing unit is stationary, while the material moves through it. The control synchronizes the movement speed of the material in relation to the printer, and the rows of printing heads are set to give a homogenous printed image. The material is a continuous web, or it is fed as sheets. The ink jet printing heads are piezo printing heads, arranged in groups, secured to a mounting with positioning units (16). A number of mountings are assembled and secured in a carrier, along the line direction. The carrier has supply channels for the ink and/or a coolant fluid to the printing heads (10). The ink feed is an overflow circuit, and the ink is moved to the printing heads by atmospheric pressure. A cleaning fluid is delivered to the printing heads through the ink supply circuit. The printing head, with the positioning units (16), can have a coolant fluid channel (22). The carrier has an electric heater, to heat the printing head (10) fitted to the carrier. The coolant fluid circuit for the printing heads (10) is temperature controlled. An under pressure system can be applied to one or more ink jet printing heads, to extract ink and/or cleaning fluid in a flow direction from them.

Description

The present invention relates to a printing device according to the preamble of claim 1.

Such printing devices are used in industry len production area, especially for the Be printing of large format carriers, such as paper, tex til, plastic or textile webs or the like. Materials. In the context of the present invention, the format is said to be large an arrangement can be understood that has a greater pressure wider than about A3 allows (about 40 cm).

While in the office area for small format applications, for example letterheads, numerous printing processes for creating individual printing units or small editions exist (laser, for example, are popular or ink jet printing), such applications especially for large format solutions in industry Use too slowly, too susceptible to errors, and therefore rell unusable.

Depending on the type and number of industrially printed Substrates - foils, paper, cardboard, solid plastic or Metal parts etc. - become different printing tech technologies applied depending on the character of the enraged ing print image. For large format reprints are mainly flexographic, offset and screen printing used. Templates (clichés) are used for both processes or sieves that were created in advance and then in the printing device can be installed on a drum  have to. In advance, an image to be printed must generally be made by one specialized graphic artist and then created by one Cliché manufacturers are implemented. More operational The installation of such problems presents difficulties Clichés in the printing device, especially when Purpose of full color printing clichés on four drums must be brought into line with each other; in addition, after the completion of a print job the Remove and clean clichés. Are also through the described printing process generally only flat, flat Print substrates effectively. Ultimately restrict also the width and circumference of each printing drum possible size of what can be produced commercially Printed image.

In contrast, individual prints are used in industrial printing often stamped in so-called pad printing. As a stamp (tampons) serves, similar to the flexo process Plastic cliché; with full color printing a must printing part for this purpose four times (if possible fit nau) are stamped. With regard to the installation or Set-up times are similar to problems as in continuous ornate flexographic printing.

This is the main problem with the known printing processes for large or small, large format print jobs, for example for printing on boxes, in that not only effort and Preparation of the print very complex and therefore high Quantity or requirements are necessary, but also the achievable dimensions of the printed image are through the Printing system limited.  

Due to the ever shorter life cycles of Products and devices and an ever increasing demand more attractive - and more revealing, with a respective Package contents matching packaging (for example in the growing self-service market, where the Selection of a product by a customer sometimes alone based on the illustration on a packaging) ent there is increasing demand, small quantities from Verpac kungen or small series of textiles, wallpaper and much more. With at least the previously known, if not a better one To be able to print print quality. This applies in particular also the color printing.

A solution that meets these requirements for large format applications Turns with reasonable effort, with the necessary Flexibility and suitability for the stresses of an in industrial use are not yet available act.

The object of the present invention is therefore a gat to create appropriate printing device that is more flexible Wise, with the shortest set-up times and with an appropriate distance speed of printing large format Substrates - paper, cardboard, textiles, foils etc. - made possible light without about a dimension of the printed image in egg ner feed direction due to mechanical conditions (about a drum diameter) is limited.

The task is carried out by the printing device with the characteristics len of claim 1 solved.  

This advantageously allows for large format Inkjet line printing processes implemented in the field the simultaneous printing of a potentially unlimited and print line practically up to several meters wide continuously and with considerable printing speed can be guided over the substrate. It also ensures the modular structure of the printing device for a Reali sierbarkeit of the invention by means of inexpensive procurable rer individual components, such as (of preferably as Piezo-Ele ink jet printheads, which are then printed in flexible and configurable way to the ge Desired print format can be adjusted.

Advantageous developments of the invention are in the Un Described claims.

So it is particularly preferred to use the modular one To fix the printing unit stationary, during one - before pulls web-shaped - printing substrate under this unit can be passed through. In this way, an ef fective length of a print image (in a feed direction) practically only through the available computer capacity or limited memory.

The design of the inkjet print heads as piezo printing heads not only have a long lifespan advantageous suitability for industrial use; also can a wide variety of different ink liquids can be used without the proper Printing operation of the arrangement according to the invention is impaired would.  

It is also particularly preferred the modular implementation the invention with the help of grouped together Make printheads, each out as a group can be exchanged or serviced. One in particular rail-shaped carrier unit is used in a particularly suitable manner Way to accommodate a plurality of such groups and also enables exact positioning and Alignment in the row direction, so that a continuous Print image is created. In addition, such is a Trä unit also suitable for both a central ink and also a central coolant supply for the To carry out most of the modules provided for; in Er addition is also local (i.e. remote from one central control computer) provided control electronics in attachable to the support element.

According to the invention, a temperature control is provided tion or a constant temperature of the printheads to guarantee an optimal operating temperature afford that not only a continuously operated cooling liquid cycle is created, but beyond from individually controllable, individual printheads Duell assigned heating elements quickly and flexibly electronically heating a respective printhead can act, so that in particular not currently be used heads (i.e. not warmed by the printing operation) can be kept at a favorable operating temperature nen.

For this purpose, according to the invention is a respective one Carrier element assigned to ink jet print head det.  

According to a further embodiment of the invention it is also possible to use the individual inkjet printheads in the Rows - based on the feed direction or based on the line direction - to arrange obliquely (inclined); on this way the effective print density of the he ranged printed image, about the linear distance of individual Increase inkjet nozzles of a printhead further; here too the associated coordination or control by the control unit provided in the training Made within the scope of the invention.  

Further advantages, features and details of the invention result from the following description more preferred Exemplary embodiments and with reference to the drawings; this show in:

Figure 1 is a perspective view of an ink jet print head in an inventive, provided for a precise alignment print head carrier.

FIG. 2 is a perspective rear view of the print head carrier from FIG. 1 with a schematically drawn heating resistor;

Figure 3 is a perspective view of a modular arrangement of print heads in a for a printing ink seen in cross-section U-shaped array rail.

Figure 4 is a perspective view of a three sub-modules for insertion into the arrangement of Figure 3 is provided for print head module with a total of 27 print heads..;

Fig. 5 is a plan view of the support plate of a Submo module of Figure 4 for nine printheads.

FIG. 6 shows an arrangement of four array rails of FIG. 3 for four-color printing;

FIG. 7 shows a plan view of the arrangement of FIG. 6 with submodules or modules shown;

FIG. 8 shows a side sectional view of the arrangement according to FIG. 3 or FIG. 7;

Figure 9 is a schematic view of the Tintenversorgungs- and flushing system for the printhead assemblies.

FIG. 10 is a schematic view of the cooling water supply for a print head sub-module;

Figure 11 is an exploded view of the cooling water flow through triads of print heads in a submodule.

Figure 12 is a bottom perspective view of a submodule with supply lines for cooling water and ink, and the ink distribution in the submodule.

Fig. 13 is a perspective sectional view of U-shaped array by a rail with an inserted sub-module and associated electronics, and

Fig. 14 is a functional block diagram showing essential electronic functional components of the printing device to the invention OF INVENTION.

Fig. 1 illustrates the attachment and alignment of egg nes ink jet print head 10 in a print head carrier (adapter) 12 , which is designed in the manner shown as an aluminum block. In the area on the engagement side - in FIG. 1 at the top - the print head 10 has a nozzle arrangement 14 - of 128 in the exemplary embodiment shown - ink jet nozzles along a row. Such a print head, which is manufactured by the manufacturer MIT (Modular Inkjet Technology), is based on the piezoelectric process; Piezoelectrically active elements for each ink jet nozzle are arranged in such a way that an associated channel is reduced by the application of a voltage and ink is ejected through a respective nozzle (such piezoelectric ink jet heads are particularly suitable for the present application area compared to known ink jet heads of so-called bubble jet technology, which are based on the principle of heating small drops of ink, due to their significantly longer lifespan and their basic suitability for almost any inks, especially solvent inks, which are required for printing on many common plastics.)

On the adapter 12 , which has a high-precision, flat receiving surface for receiving the printhead unit 10 , the printhead 10 is fixed by gluing at three points, and a thermal adhesive is used for the heat transfer. For a precise centering of the adapter 12 carrying the printhead in a carrier or module arrangement, which will be described in detail later, the adapter 12 has a pair of centering tips 16 which, extending upwards, fasten to projections 18 of the adapter block 12 and, are aligned according to the course of the nozzle arrangement 14 . More specifically, a respective centering tip 16 is inserted into a - not shown - over-dimension bore of a respective projection 18 , was fixed there with adhesive, aligned under a microscope with respect to the nozzle arrangement 14 and then fixed by UV radiation and curing of the adhesive.

On the upper side of the adapter 12 shown , a pair of fastening holes 20 with an internal thread are additionally seen, which serve for mechanically fastening the adapter.

The adapter shown in Fig. 1 has a, indicated by the dashed lines in Fig. 1, reversed U-shaped channel 22 for cooling water, which is supplied in a manner to be described below on one side of the adapter 12 , through the Adapter block 12 flows through and can come out on the opposite side.

In addition, the adapter block 12 shown in FIG. 1 shows a further projection 24 which, as indicated by the bores shown, for supplying ink or for distributing the (bottom-side) supplied ink to a group of three printheads in respective adapters see is. The reference numeral 26 denotes the ink supply nozzle of the print head 10 , which is to be connected to the projection 24 via a hose (not shown).

The rear view of the adapter unit 12 in FIG. 1 shows an electrical heating unit 28 , which is inserted schematically into the adapter block in the form of electrical resistors which are supplied with electrical current by a circuit (not shown) and temperature control and provide additional heating for the arrangement can (in addition to the temperature influence by the cooling channel 22 , this creates the possibility, in accordance with the invention, of keeping all ink jet print heads, even those not currently being used, at a largely constant operating temperature, so that the printing behavior of the device according to the invention can be optimized)

In connection with FIGS. 3 to 8 will be described below how the ge in FIGS . 1 and 2 in adapters 12 held print heads - multidimensional - line by line and mechanically kept in an optimal, suitable for a precise pressure suitable way can.

Fig. 5 shows a top view of a cover or carrier plate 30 which can accommodate nine, in three horizontal, staggered rows of three to be arranged printheads or printhead adapter. More specifically, a respective adapter 12 is attached beneath the carrier plate 30 so that the nozzle arrangement 14 is exposed in a respective break 32 of the plate 20 , the centering tips 16 of a respective adapter 12 engage in corresponding centering holes 34 of the plate 30 centering and through BEFE stigungsbohrungen 36 of the plate 30 engaging through (not shown) screws in aligned mounting holes 20 of the adapter 12 for fixing the same. The result is a submodule consisting of nine print heads, which in the exemplary embodiment shown has a longitudinal edge extension a of 158 mm and a width b of 100 mm.

On the edge, the carrier plate 30 , as shown in FIG. 5 ge, also has three additional openings 40 arranged along a line, each for receiving control lights (not shown) (LED) or test and blow-through buttons for one respective triad of inkjet heads are provided.

A submodule constructed in this way from 3 × 3 inkjet heads can then be arranged line by line and arranged and fastened in a cross-sectionally U-shaped array rail 42 , as shown in FIG. 3; edge-side bores 44 in the carrier plate 30 allow the screwing of a plurality of submodules 38 in an array rail. 5 for the submodule 38 shown in FIG. 5, the respective adapters 12 and the ink jet nozzle arrangements 14 of the print heads held there are arranged such that in a (line-by-line) printing direction perpendicular to the paper feed along arrow 46 an uninterrupted, con results in continuous pressure line, the arrangement of several submodules in the carrier rail 42 enables a continuous continuation of the pressure line via a submodule 38 . More specifically, the next higher arrangement of the sub modules 38 is in the form of modules 48 , one of which is shown in perspective view in FIG. 4. Such a module then has an overall length c of 474 mm in the direction of the printing line. The figure also shows how the individual adapters 12 or the inkjet print heads 10 attached to them are provided in arrays or submodules on the carrier plates 30 which are seated one against the other.

The array rail 42 is a U-shaped, one-piece rail, which - comparable to the centering of the adapter 12 in a submodule plate 30 - offers an additional centering option for the submodules via positioning pins in the rail 42 .

A respective rail 42 thus not only specifies a maximum printing width (d = 3 m in FIG. 3) provided for one embodiment; on the bottom, it also accommodates parts of the control electronics for the respective print head subarrays as well as supply lines for cooling water and ink in a manner to be explained in more detail below.

In the top view in FIG. 7 and in the side view in FIG. 6, four of the array rail arrangements shown in FIG. 3 with submodules inserted are provided; in this way, in the printing direction along arrow 50 , four-color printing is possible in that four colors are applied one after the other and each array rail 42 carries ink of one of these four colors. As shown in FIG. 6, the respective array rails 42 can be laterally attached to one another and each have an arrangement on the bottom for a coolant supply 52 , a coolant discharge 54 and an ink supply 56 .

As the longitudinal section through the arrangement of Fig. 3 and Fig. 7 shows, a lower floor 58 is ge under a respective array rail 42 at an angle of about 10 °, so that from each of the printheads before a cleaning regained Ink can flow back into a reservoir according to the manner to be explained in more detail below.

Each of the array rails 42 also has a section 60 on the end for electrical supply lines or

Plug and a (not shown) bracket holder, with which a respective array rail for possible improvements cleaning by hand, the installation of individual mo dule etc. can be rotated or pivoted.

The arrangements shown in this way enable the precise Centering in the horizontal direction (based on the Printheads of a submodule to each other) a position deviation less than 13 microns in both X and in the Y direction; between the print heads of two print modules this directional deviation is less than 20 microns (This applies, for example, to a nozzle spacing of Print heads of 137 microns, corresponding to a write density of 185 dpi (dot per inch)). The accuracy is over so remarkable than when using four modules (with three submodules each) along an array rail simultaneous line printing with a printing width of 1895 mm is possible, and when using 6 modules from 2850 mm.

The ink flow in the printing device according to the invention is explained below with reference to FIG. 9, specifically by the flow arrangement shown in FIG. 9 ensuring both the supply of the respective individual printheads with ink and, for cleaning purposes, with a cleaning fluid .

An ink reservoir 62 holds the ink to be supplied to the entirety of the printheads of a printing device and receives an ink reflux; a corresponding tank 64 contains a suitable cleaning liquid which, alternating with the ink, is fed to the print heads. 9 in this respect, FIG. 62 a flow which acts on nacheinan the three groups of printing heads 10 with ink (or cleaning liquid). A hose pump 68 is used for the delivery to the print heads, which offers numerous advantages for the present application (in addition to the self-priming effect and the variable speed, this can also be easily deactivated, two-way operation for suction is possible, and the Pumpme dium is separate from the pump mechanism).

As shown in FIG. 9, by means of the distributor shown in FIG. 1 on the projection 24, one of the adapters 12 ink from the first printhead 10 _{a of} a first group of three (more precisely: the associated adapter 12 ) to neighboring printheads 10 _a 'or 10 _a ''passed, the three printheads 10 _a , 10 _a ' and 10 _a '' are adjacent to each other in the printing direction printheads in a submodule and the printhead 10 _{a is} the central or central of this group of three. The same applies to the printheads 10 _b , 10 _b 'or 10 _b '', 10 _c etc. At the end of the feed 66 , an overflow vessel 70 is provided by means of a valve, which not only ensures according to the invention that ink overflowing in the direction of arrow 72 returns 74 and so the ink circuit can be closed; in addition, the overflow vessel 70 ensures that the respective ink level - symbolized by the horizontal line 76 in FIG. 9 - is in each case at ambient pressure and so the ink level in the respective printhead can be checked (if, for example, there is overpressure in the inkjet printhead (as generated by the peristaltic pump 68 for ink delivery, ink would undesirably be pushed out of the nozzles).

The ink flowing back through the return 74 is fed back into the ink reservoir 62 via the three-way valve 78 . Also flows during an ink suction process - before cleaning the printheads with the cleaning fluid, ink is drawn off from the printheads or the flow by reversing the pump operation - unneeded ink through a further three-way valve 80 assigned to the peristaltic pump 68 into the Tank 62 back. The respective units are connected to one another by means of schematically illustrated isolating couplings 82 .

After the remaining ink was sucked out of the heads in preparation for the cleaning operation by reversing the pump operation, by actuating the three-way valve 80 and activating the pump 68 in the conveying operation, cleaning liquid is now flushed through the printhead arrangement until the intended cleaning purpose is fulfilled ; in a corresponding manner, the activation of the printing operation is then switched over to the application of ink.

The arrangement shown - the illustration of FIG. 8 also clarifies the corresponding direction of fall for back-flowing ink - enables a very large number of printheads to be supplied with ink at a constant pressure in a comparatively simple yet efficient manner, without the need for a Print result would deteriorating overpressure would be generated; a composed of six modules (see. Fig. 4) printing arrangement in an array rail 42 with a printing width of just under 3 m comprises no less than 162 ink printheads, which in the described manner evenly applied with ink to who.

Analogously to the ink circuit, the application of cooling water to the printhead arrangement is described below with reference to FIGS. 10 and 11.

Thus, in particular for the Druckvorrich device according to the invention, a storage tank 84 for cooling liquid (in particular cooling water) is provided, which is additionally provided with a heat exchanger 86 for controlling a predetermined temperature of the cooling water.

From the reservoir 84 where (see. Fig. 3 or Fig. 6), pump by means of a cooling water 88 cooling water continuously through a respective Ar rayschiene 42 pumped, a hinlaufender cooling water line 90 for the supply of cooling water 52 and a back traveling strand 92 keitsabfuhr for the cooling liquid 54 are provided; at the end, the cooling water circuit is closed by a suitable pressure valve.

While Fig. 10 shows schematically the flow of cooling water through a submodule, Fig. 11 illustrates the overall principle in an extended manner. Fig. 10 shows that - contrary to the ink flow of Fig. 9, which emanated from a middle printhead of a group of three in a submodule - the cooling water flows in series through all three adjacent heads, in accordance with the order 10 _a ', 10 _a - 10 _a '' and correspondingly in parallel for the next group 10 _b '- 10 _b - 10 _b ''etc. A respective group of three is connected by means of a plug-in coupling 94 to the strand 90 or the strand 92 running back . In the manner shown, not only can cooling of printheads (or associated adapter carriers) heated by use be achieved in an efficient manner, but it is also possible to advantageously keep the temperature of the printhead arrangement largely constant. It is thus advantageously achieved that when the print is resumed with a head that has not been used for a longer period of time, its print quality does not differ from that of other, neighboring heads that are heated by printing operation.

This temperature control is advantageously carried out for one by a mechanical, dynamic control of the Coolant flow rate according to the amount using a Thermal valve.

In addition, heads are selectively heated with the help of the heating unit 28 ( FIG. 2) in order to keep them at the same temperature as other heads, such as heads heated in the printing operation. This heating is carried out with the aid of a temperature-compensated electronic control of the counter 28 shown . Specifically, it is achieved in this way that before partially heated, but a maximum operating temperature of the heads of 40 ° C is not exceeded; the ideal value is around 35 ° C. The cooling medium must not exceed a temperature of 25 ° C (ideally 20 ° C); especially after prolonged printing operation, heat is removed from the coolant storage tank 84 by means of the heat exchanger 86 for this purpose.

Fig. 12 shows in perspective view from below how ink and cooling water are supplied and distributed within a respective tri-group of printheads in a submodule.

As an average, central ink supply 96 is particularly useful for each of the three groups of three shown, the vertical with the central ink supply 56 in the array rail (see. Fig. 3, Fig. 6 or Fig. 13) is connected, and a vertical water feed 98 and water discharge 100 is connected to the central liquid supply 52 or discharge 54 in a suitably pluggable manner.

FIG. 12 now shows the ink supply nozzle 26 ( FIG. 1) of the middle adapter 12 , of which three, in relation to the ink supply for a respective central (middle) printhead in a row of three 10 _a , 10 _b , 10 _c (reaching into the sheet) Lead ink hoses 102 , 102 'and 102 ''to print heads 10 _a , 10 _a ', 10 _a '' and 10 _b , 10 _b ', 10 _b ''and 10 _c , 10 _c ', respectively. In addition, brackets 104 are shown, which connect the cooling channels of a respective adapter 12 sequentially to one another in the manner shown in FIGS. 10 and 11 and are correspondingly tubular, so that a continuous coolant loop takes place between a water supply nozzle 98 and an associated discharge nozzle 100 .

In Fig. 13 this arrangement is now shown with a vice versa array rail 42 in sections; Fig. 13 also illustrates how electronic printed circuit boards are arranged for a respective submodule in the array rail. More specifically, a base board 106 is provided on the bottom of the rail 42 ; this has the openings 96 to 100 for carrying out the corresponding openings.

The respective electronics, which are necessary for local control of the print heads, which will be explained in detail below, are located on the base board. In addition, a vertically extending connection board 108 is schematically shown in the left-hand area of FIG. 13, which - for example by means of the flat ribbon connections 110 shown - couples the respective print heads to the control electronics.

With reference to the block diagram in Fig. 14, the control electronics for the Druckvor direction shown above will now be described. For an approximately 1.90 m wide printing arrangement with four modules, consisting of a total of 108 printheads each with 128 nozzles, a 2 × 8 bit wide, parallel control is necessary for each module, with a repetition rate of each nozzle of an ink head up to 8500 Hz is. This requires considerable effort to create this large amount of data in parallel on the entire line to be printed from printheads.

Correspondingly, the arrangement shown in FIG. 14 has a central print controller 114 , which is supplied via an input data bus 116 with print image data of a suitable data format - for example PCL 5, Postscript or other suitable protocols. A corresponding plurality of data channel controllers 118 are then connected to the controller 114 , each of which is assigned to a print head module (corresponding to three submodules or 27 print heads). The channel control unit 118 communicates with the controller 114 via a high-speed data transfer, in particular by means of direct memory access (DMA) indicated by the arrow 120 . The control units provided to the left of the vertical dividing line 122 in FIG. 14 are suitably contained in a remote computer unit, for example a PC. Each channel control unit 118 is then connected via a data bus 124 to a local control unit (base board) 106 in a respective array rail 42 , which further processes and distributes the received data to one of three submodule boards 126 , corresponding to a respective submodule 38 . The submodule boards 126 control the respective printheads of the submodule assigned to them and for this purpose each have a buffer provided.

In operation, the printer controller 114 receives the data and commands to be printed in the respectively selected, standardized emulation and uses this data to produce the printed image with the desired rasterization; This is significant insofar as - since the print line is distributed over three nested print head lines - a data grid to be printed in each case has to be adapted to a current feed speed of the web transport under the print line. More precisely, the controller 114 controls the assignment of the print data in accordance with the offset of the individual print heads in a line and the transport speed of the print web transport in such a way that a continuous, homogeneous print image of the desired resolution — in the described embodiment, 185 dpi — is produced. Depending on the mechanical realization of the transport device for the printing material or the material web to be printed under the stationary printing device according to the invention, which is not described in more detail in the present application, a practical printing speed of about 58 cm is thus also possible in the feed direction at a resolution of 185 dpi / sec. to reach.

According to a further development, there is also a Feed detection for the substrate to be printed to provide, which is suitable, for example, the influence downstream units - such as a punching unit with their influence on printing speed - too consider. Depending on this captured, for example slower, feed rate of the printing material could then in the invention How the printing can be adjusted or controlled.

In particular, further training is also provided that, by suitable manipulation of the rasterization in the controller or the downstream storage and buffer units, an electronic displacement of a Li to be printed can never take place by one or more dots, for example when an array rail 42 is not complete is adjusted perpendicular to the printing direction, but deflects from the vertical by about one or two points. Then no mechanical readjustment is required, only the exact orthogonality of the print line is then established by an electronic measure.

In the case of multi-color printing in particular, the controller 114 with the downstream electronic units ensures a correct and positionally accurate printing process. According to the invention, it is also possible, in particular, to supply the print image data via a network interface.

According to an alternative embodiment of the invention, it would be possible, even the described printing device with a or several array rails movable and over to maintain a static print substrate; choosing one ever transport system and its control is dependent of a particular application and is of that spoke specialist, as well as the specific movement control tion, with measures known from the prior art perform.

In the manner described, a Printing device which, according to the invention, is not only exceptional usually wide printing substrates, such as cardboard or pla Katbahnen, line by line and therefore with the highest speed can print on; It is also advantageous possible a print image in the dimension of the feed direction theoretically unlimited and practically only limited through the available print image storage (a Work used in the described embodiment memory of 64 MB RAM enables with the shown resolution solution to create a monochrome print image of a Area of about 7.5 square meters).

The present invention is therefore particularly suitable for applications in the field of cardboard manufacture or Boxes in the textile industry for printing fabric in the graphic industry for immediate printing of posters or the like. Large-format printing goods, for Er testify to wallpaper, etc., the one-off costs for the Print an image are minimal. Therefore it is in use of the present invention printing small quantities (estimated up to about 5000 sqm) much cheaper than with  the conventional methods such as flexo or offset printing, previously used for these use cases become. Generally speaking, the benefit of the present Er show the more clearly, the lower the concrete quantities to be printed or the edition is, so that the before lying invention for optimal flexibility one Printing station ensures.

This is especially for the application field of Printing on boxes or boxes is a completely new one Flexibility and adaptability to specific customer requirements created: So it would be by means of the present invention now possible for the first time, directly in a rational manner the outer carton with a concrete illustration and / or one Description of the subject contained therein hen, even if the carton is not in a meh reren 100,000, but only in a few copies 100 pieces are printed (such a procedure with Realizing conventional printing processes would be undesirable socially). The same applies to the detection and opening print variable data, such as date, serial number or address directly on a box.

The ink jet heads used on the invention on pie zobasis are characterized by their long lifespan, the just in an industrial production environment long downtimes.

A major advantage of the present, flexible technology is that, in addition, the subsequent rasterization in the controller 114 or an upstream computer unit means that virtually no mechanical changeover time is required; For example, the rolls with plastic clichés for cardboard printing from flexographic printing technology had to be converted for each new print run in a costly and time-consuming manner before a printing system could perform a subsequent, modified printing task. In contrast, the present inven tion makes it possible to switch practically continuously from one artwork to the next without any mechanical changes being necessary.

The advantageous suitability of ink jets in particular he also makes it for a slightly wavy environment Technology according to the invention also for the corresponding sub basic material, for example CDs, wallpaper or the like. usable and powerful.

According to a further development according to the invention, for example the print resolution of the image with the Increase used inkjet printheads in that instead of horizontally arranged printheads, as in the figures shown this, based on the pressure line or the Vertical to the feed direction, inclined or tilted are arranged. In this way it is practically an increase Printing density up to about 240 dpi, theoretically up to 360 dpi, possible, depending on the inkjet print head used.

It is also according to an advantageous further development possible to rotate the entire printing device in this way to design that the printheads or their outlet nozzles can point downward in a twisted position. A such an arrangement is particularly suitable for Purification purposes, because then in such a case  Ink or cleaning fluid immediately down can leak.

According to a preferred development, it is also the Invention possible, a - not shown in the figures - To provide cleaning device, which sealing over each of the print heads can be placed and in the art a suction device liquid of the print heads upwards can suction. More specifically, such an arrangement is printhead or group specific, but for the entirety of the printing device along a plate od. Like. Carrier arranged so that for the entire Pressure device then a corresponding suction can be carried out. Additional training experiences this solution in that by means of the device additional liquid can also be introduced, the then as a cleaning agent - via the outlet side End - the printheads can enter this and on this way for a full pressure flushing of the same worries about dirt or foreign bodies that not suck in or blow through Have the spray direction removed.

Claims (15)

1. Printing device for line-by-line simultaneous printing of a preferably large format carrier material, in particular of large format cardboard for packaging or the like, with a printing unit and a carrier material guide associated therewith, characterized in that the printing unit as a modular, line-by-line arrangement of a plurality of ink jet Printheads ( 10 ) is realized, which is arranged in a vertical direction perpendicular to a feed direction ( 46 , 50 ) of the printing unit or the substrate guide line overlapping one another in at least two rows and for generating a continuous print image in the line direction by means of one Control unit ( 114 to 126 ) can be controlled electronically. 2. Device according to claim 1, characterized in that the printing unit is stationary relative to the to this movably formed carrier material tion is formed and the control unit for syn chronize a feed rate of the Trä germ material guide relative to the printing unit and the rows of printheads is formed so that a homogeneous print image is created.   3. Device according to claim 1 or 2, characterized records that the carrier material is endless and web-like mig or sheet or piecewise can. 4. Device according to one of claims 1 to 3, characterized characterized in that the ink jet printheads as Piezo print heads are realized. 5. Device according to one of claims 1 to 4, characterized in that the ink jet printheads are group by group in a with a positioning device ( 34 , 16 ) provided mounting unit ( 30 ) are attached. 6. The device according to claim 5, characterized in that a plurality of the mounting units in the row direction in a carrier unit ( 42 ) is combined and fixed. 7. The device according to claim 6, characterized in that the carrier unit supplies for an ink supply and / or a coolant supply for the ink jet printheads ( 10 ). 8. Device according to one of claims 1 to 7, characterized in that an ink supply for the ink jet print heads takes place in a circuit having an overflow unit ( 70 ), with which ink can be supplied to the ink jet print heads at ambient pressure. 9. The device according to claim 7 or 8, characterized records that the inkjet printheads over the Feeders for ink supply with a Reini supply liquid are acted upon. 10. Device according to one of claims 1 to 9, characterized in that an ink jet print head ( 10 ) is provided in each case on a carrier element ( 12 ) which has an alignment device ( 16 ) and a channel ( 22 ) for a cooling liquid. 11. The device according to claim 10, characterized in that the carrier element has an electric heating element ( 28 ) which is designed for heating the ink jet printhead ( 10 ) attached to the carrier element. 12. Device according to one of claims 1 to 11, there characterized in that a temperature controlled Coolant circuit for the inkjet printheads is provided. 13. The apparatus according to claim 6, characterized in that the carrier unit for at least one board control electronics for the in the carrier unit mounted inkjet printheads. 14. The apparatus according to claim 13, characterized in that the board has a local buffer memory for the Has printheads.   15. The device according to one of claims 1 to 14, characterized by an individual or the Most of the inkjet printheads are attachable Vacuum device used to suck off ink and / or cleaning fluid from the Inkjet printheads in one direction the same is formed.