EP1507665A1

EP1507665A1 - Inkjet printing device

Info

Publication number: EP1507665A1
Application number: EP03730054A
Authority: EP
Inventors: Richard Piock; Franz Obertegger
Original assignee: Durst Phototechnik AG
Current assignee: Durst Phototechnik AG
Priority date: 2002-05-29
Filing date: 2003-05-16
Publication date: 2005-02-23
Anticipated expiration: 2023-05-16
Also published as: ATE465011T1; US7347540B2; EP1507665B1; ES2344835T3; WO2003099570A1; JP2005535468A; CN1655941A; DE50312643D1; AU2003240660A1; CN100337829C; US20060038861A1

Abstract

The invention relates to an inkjet printing device (1) comprising at least one printing head (2). Several tanks (3, 4) for inks and/or a cleaning medium are arranged upstream of a connection opening (7) for the printing head (2) and the tanks (3, 4) are connected to the connection opening (7) for the printing head (2) by means of supply lines (5), a blocking organ (6) being placed between each tank (3, 4) and the connection opening (7).

Description

Inkjet printing apparatus

The invention relates to an inkjet printing device and a printhead for inkjet printing devices, as described in the preamble of claims 1, 31.

Ink jet printing devices or ink jet printers are already known in which an ink tank or ink reservoir is arranged upstream of a nozzle or a nozzle group of a print head for applying or discharging inks. The ink reservoir is connected via channels to the nozzle or the nozzle group on the one hand and via a feed line to the ink tank on the other hand. The disadvantage was that due to this type of ink supply, only drawer devices could be produced with which only one type of ink can be processed. To process different inks, it was necessary to completely retrofit the machine.

The need for inkjet printers with different ink systems, i.e. To be able to operate inks of different types is particularly given in the industrial area, with which one and the same printing device is to be used for printing on different materials, such as paper, cardboard, plastic films or even textiles. For this purpose, solutions have already been proposed which make it possible to convert an inkjet printer for different ink systems.

US 6024441 A describes an inkjet printing device consisting of ink tanks, flexible feed lines and connecting units for the print heads. For the different colors of different ink systems, feed lines lead from the ink tanks to a connection unit belonging to an ink system.

The printheads of the inkjet printing device are in turn connected to the printhead connection units with printhead connecting parts, which ensures that the printheads are supplied with ink. To convert the inkjet printing device to a new ink system, it is necessary that the printheads are removed from the inkjet printing device by detaching the printhead connection parts from the printhead connection units. The printheads are then replaced, connecting the new set of dracking heads to the printhead connection units of the new color system. The change of the ink system in ink jet printing devices, as described in US Pat. No. 6,024,441 A, is therefore associated with a considerable amount of manipulation for removing or installing the print heads. The present invention has for its object to provide an ink jet printer that enables universal use without long changeover times on the ink jet printer.

This object of the invention is achieved by spoke 1. This is advantageous

Design that different ink systems or inks with different properties, viscosity, color, dye concentration, etc. can now be processed with a set of drack heads. For the changeover, the different tanks are only connected to the drain heads by appropriate adjustment of the shut-off devices, a change of the drain heads or a complete retrofitting of the ink jet printer or the ink jet printer is not necessary, however, and the advantages of each type of ink can still be exploited via a single ink jet printer ,

The further development of the ink jet stretching device according to claim 2 achieves the advantage that the reservoirs provide an intermediate or buffer memory for storing the inks, and thus provide protection against operational interruptions due to empty tanks.

The development of the inkjet printing device according to spoke 3 offers the advantage that the ink can flow into the print head to the required extent and thus impairments in the print quality can be avoided.

Through the development of the ink jet printing device according to claim 4, wherein a reservoir is arranged in the print head, ink jet printing devices of a substantially more compact design can be produced in an advantageous manner.

A further development of the ink jet stretching device according to spoke 5 is also advantageous, since it is possible to find enough with fewer components. By designing the shut-off devices by means of a common multi-way valve, the risk of malfunctions is also reduced since it is not possible for inks or the cleaning medium to flow into the printhead from several tanks at the same time.

The development of the inkjet printing device according to claim 6 offers the advantage that the supply of the ink or the cleaning agent into the drain head is independent of the effect of gravity and thus the tanks in any areas of the ink jet printer can be arranged. The pumps ensure the delivery of the ink or cleaning agent in any case.

By designing the inkjet printing device according to spoke 7, it can advantageously be avoided that contaminants get into the drain head and the

Nozzles are clogged.

The development according to claims 8 and 9 is also advantageous, since pressure decoupling of the ink in the print head or in the corresponding reservoir from the pressure in the corresponding tank can be achieved in this way.

The further developments of the inkjet printing device according to spoke 10 to 14 have the advantage that the inks can always be kept in the operating temperature range that is most favorable for their processing and the supply of the drain head with ink can be automated and in particular program-controlled.

The design of the ink jet printing device according to spoke 15 offers the advantage that it can be used to produce ink jet printing devices with a very wide range of applications. Inkjet printers with such inkjet printing devices can be used in inkjet printers of various designs and in a wide variety of fields of application.

The development according to claim 16 is also advantageous, since the cleaning of the print heads which is possible as a result of this makes it possible to significantly shorten the changeover of the inkjet printing device to a new ink system and thus, in particular misprints, can be avoided by the temporary and undesirable mixture of inks of different ink systems.

The development of the inkjet printing device with a fill level sensor according to claims 17 and 18 offers the advantage that the fill level of the inks in the reservoirs can thus always be determined. This also ensures that there is always sufficient amount of ink in the reservoirs and thus prevents the ink supply in the reservoirs from being depleted and the printing process being interrupted or, subsequently, incorrect printing occurring. By designing the inkjet printing device according to claims 19 to 22, by forming the reservoirs or the distribution chamber with ventilation openings or a pressure control valve, in particular a servo valve, it is advantageously ensured that the ink from the reservoirs can flow freely into the area of the spraying devices. can flow. This avoids that fluctuations in pressure occur in the distribution chamber of the pressure head and, as a result, ink droplets of different sizes are ejected from the pressure head, which influences the quality of the pressure.

The further development of the ink jet stretching device according to spoke 23 offers the advantage that penetration of dust particles from the ambient air into the drain head and subsequently clogging of the nozzles of the drain head can be prevented.

The further development of the inkjet printing device according to claims 24 and 25 is also advantageous, since pressure fluctuations in the feed lines or the reservoirs which disturb the ink delivery can thereby be reduced. This is because the fluctuations in the pressure of the ink occur particularly due to the acceleration forces acting on the ink, which occur when the head of the ink moves in the transverse feed direction across the printing medium.

The design of the inkjet printing device has the advantage that in the event that an ink is not currently in use, it is conveyed in a circuit and thus the deposition of components or constituents of the ink in the lines can be prevented.

The design of the ink jet stretching device according to claim 27 has the advantage that the arrangement of the ink tanks can be made more compact and, in particular, with a smaller number of tanks for the different colors of the inks of the different ink systems it can be found.

Finally, a further development of the ink jet printing device according to claims 28 and 29 is advantageous, since it enables the various operating states of the ink jet printing devices to be controlled automatically or program-controlled.

The further development of the inkjet printing device according to spoke 30 achieves the advantage that the supply of the inkjet printing device with ink or the required cleaning medium can be ensured for larger periods of time and thus an uninterrupted operation of the inkjet printing device can be ensured.

The object of the invention is also achieved independently by a Drackkopf according to the features in the characterizing part of the speech 31. The advantage here is that with a set of dracking heads for the required number of colors, inks of different ink systems can be processed. To switch between the different ink systems, it is only necessary that the shut-off devices of the drain head are closed or opened accordingly. Another advantage is that when changing over to a new ink system, the residues of the inks remaining in the reservoirs do not have to be removed, and material losses can thus be reduced.

The design of the printhead according to claims 32 to 34, in which the reservoirs are formed with ventilation openings, advantageously ensures that the ink from the reservoirs to the extent required for trouble-free operation

Area of the spray devices can flow.

The development of the printhead according to spoke 35 advantageously ensures that no dust particles or contaminants from the air penetrate into the nozzles of the printhead and can block them.

The development of the print head according to spoke 36 is also advantageous, since it makes it possible to keep the inks in the temperature range that is most favorable in their processing.

The design of the drain head according to claim 37 advantageously enables such print heads to be used for processing a wide variety of ink systems and in various types of ink jet printers.

By designing the drain head according to claim 38, it is possible to significantly reduce the time required for the changeover to the processing of inks of a new ink system and at the same time to avoid the loss of inks due to undesired mixing of the inks of different ink systems.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures. In a schematically simplified representation:

1 shows an inkjet printing device with a print head;

2 shows a print head with several reservoirs for inks or a cleaning medium;

Fig. 3 shows a detail of an inkjet printer with three inkjet printing devices according to FIG. 2 in a perspective and simplified representation.

In the introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, and the disclosures contained in the entire description can be applied analogously to the same parts with the same reference numerals or the same component names. The location information selected in the description, e.g. above, below, to the side, etc., refer to the figure described and illustrated immediately and are to be transferred to the new position in the event of a position change. Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

1 shows an ink jet stretching device 1 with a stretching head 2.

The inkjet printing device 1 consists of three tanks 3 for holding different inks and a tank 4 for holding a cleaning medium, the tanks 3, 4 being connected to a shut-off device 6 and a connection opening 7 by feed lines 5. The connection opening 7 of the shut-off element 6 is connected to a feed opening 8 of the drain head 2. The shut-off device 6 of the inkjet printing device 1 is designed in the concrete exemplary embodiment as a multi-way valve. Of course, it is also possible that each feed line 5 has a separate valve and the outlet openings of these valves open into a common connection opening 7.

The connection opening 7 for the drain head 2 is thus preceded by a plurality of tanks 3, 4 for inks and / or a cleaning medium, the tanks 3, 4 being connected to the connection opening 7 by feeder lines 5 and between each tank 3, 4 and the connection opening 7 a shut-off device 6 is arranged. Between the ink tanks 3 and the shut-off device 6 there is a reservoir 9 in the course of the feed line 5. These reservoirs 9 are arranged together with the shut-off device 6 near the print head 2, the reservoirs 9 being designed as pressure compensation tanks. A return line 10 is also formed in each case between a reservoir 9 and a tank 3 for the ink. This makes it possible to convey the ink from the reservoir 9 back into the tank 3 and has the advantage that in the event that an ink is not in use and the shut-off device 6 for this ink is closed, the ink between the Reservoir 9 and the tank 3 can be promoted in a circuit and thus the deposition of components or constituents of the ink in the lines (feed line 5, return line 10) is avoided.

The printhead 2 is designed in a manner known per se and consists of a distribution chamber 11 which is fed with ink via the feed opening 8 in a first end region and delivers ink to, in this case eight, spray devices 12 at a second end region. By actuating the spray devices 12, the ink is ejected through nozzles 13 arranged in a lower end region of the print head 2 and is thus applied to a print medium to be printed.

A pump 14 is arranged in the feeder lines 5 for conveying the inks or a cleaning agent from the tanks 3 and 4 into the print head. In order to prevent contaminants from penetrating into the print head 2, a filter 15 is also arranged in the feeder lines 5. Similarly, a pump 16 is formed in each of the return lines 10.

In the feeder lines 5 between each of the tanks 3 and the one connected thereto

Reservoir 9 is each a shut-off device 17 is arranged. Accordingly, a shut-off device 18 is arranged in the return lines 10 between each of the tanks 3 and the reservoir 9 connected to them. By means of these shut-off elements 17, 18, the reservoirs 9 can be decoupled from the respective tanks 3 with respect to the pressure, so that the ink flow in the print head 2 is stabilized.

Since it may be necessary to process the inks of some ink systems to raise their temperature above room temperature, the tanks 3 are each equipped with heating elements 20 and thermometers 21. For the same reason, the print head 2 or the reservoirs 9 are also equipped with a heating element 22 and a thermometer 23. Of course, it is also possible that the tanks 3 or the reservoirs 9 are each provided with a common heating element 20 or a common heating element 22. Accordingly, in most cases it will also be sufficient that the tanks 3 and the reservoirs 9 each have only one common thermometer 21 or one common thermometer 23.

For the automated control of the entire ink jet stretching device 1, it is equipped with a control device 24. The shut-off device 6, which is designed as a multi-way valve, is controlled by the control device 24 in such a way that only one of the feeder lines 5 is always connected to the connection opening 7 and thus the feed opening 8 of the print head

2 is connected. From the tank 3, the feed line 5 of which is in the open state with respect to the connection opening 7, ink is conveyed from this tank 3 via the corresponding reservoir 9 into the distribution chamber 11 of the drain head 2 with the aid of the pump 14. The corresponding pump 14 is also controlled by the control device 24. The delivery of the ink from the reservoir 9 into the distribution chamber 11 can be effected either by the force of gravity on the ink or by a separate pump arranged between the reservoir 9 and the shut-off device 6 ( not shown).

To measure the fill level of the ink in the corresponding containers, the tanks 3 are

Reservoirs 9 and the distribution chamber 11 of the drain head 2 are equipped in their interior with a level sensor 25. With these fill level sensors 25, the fill level can be continuously measured by the control device 24 connected to it. In a preferred embodiment, these level sensors 25 are each arranged in an upper end region of the tanks 3, 4, the reservoirs 9 and the distribution chamber 11. In order to enable pressure equalization with the ambient air drain, the reservoirs 9 and the distribution chamber 11 of the print head 2 are each equipped with a ventilation opening 26. The ventilation opening 26 in turn has an air filter that prevents dust particles from entering the nozzles 13 of the drain head 2 and clogging them.

Alternatively, however, it is also possible that the print head 2 does not have its own ventilation opening 26 and no level sensor 25. In this embodiment variant, the distribution chamber 11 of the printhead 2 is completely filled with ink and the pressure equalization with the ambient air pressure can take place via the ventilation opening 26 of the corresponding reservoir 9 or a suppressor can be applied in order to prevent the ink from escaping. A pressure control circuit is preferably connected to the ventilation opening 26, through which the pressure in the distribution chamber 11 or the corresponding reservoir 9 can be adjusted in such a way that ink does not leak out of the nozzles 13 of the print head 3.

The pump 14 and the shut-off element 6 are always actuated by the control device 24 in such a way that the fill level of the distribution chamber 11 and the reservoirs 9 with ink is in a predetermined range.

The control device 24 is thus designed such that it can be used to fill the distribution chamber 11 of the drain head 2 or the reservoirs 9 with ink, this filling being able to take place semi-automatically as well as fully automatically. With the aid of the level sensors 25 in the tanks 3, 4, the control device 24 can also be used to refill the tanks 3, 4 with the appropriate inks or a cleaning medium from refill containers connected to them and set up separately from the inkjet printing device. In this way, uninterrupted operation of the ink jet printer can be achieved.

The corresponding tank 3 as well as the reservoirs 9 and the printhead 2 are heated by the heating element 20 or the heating element 22 to that required for the corresponding ink

Operating temperature maintained, the actual temperature is determined by the thermometers 21 and 23 in cooperation with the control device 24 and thus the compliance with the operating temperature can be monitored.

If the ink jet cracking device or the ink jet cracker is now to be converted for printing on another medium, it will in most cases also be necessary for the ink jet cracking device to be processed on inks of another ink system, i.e. to another type of ink. 1, this is advantageously possible in that the print head 2, i. whose distribution chamber 11 and its spray devices 12 with the

Nozzles 13 are first cleaned with a cleaning medium. For this purpose, the control device 24 sets the shut-off element 6, which is designed as a multi-way valve, in such a way that the feed line 5 of the tank 4 is brought into the open position with respect to the connection opening 7. By actuating the pump 14 of the tank 4, cleaning agent is then pumped into the drain head 2. By simultaneously actuating the spray devices 12 thus the remnants of the remaining ink are removed from the print head 2 and the distribution chamber 11, the spray devices 12 and the nozzles 13 are cleaned.

In addition to this cleaning process by supplying the cleaning medium, it is also possible for compressed air to enter the through a separate feed line (not shown)

Printhead 2 is blown in and thus residues of the cleaning medium remaining in the drain head 2 are removed from the drain head 2. For this purpose, it is of course necessary that the ventilation opening 26 of the drain head 2 is closed by a corresponding valve (not shown). It is particularly advantageous to design the ventilation openings 26 of the print head 2 and the reservoirs 9 by means of a pressure control valve or a servo valve.

In an alternative embodiment variant, instead of using a cleaning medium, it is also possible to blow out the “old” ink by applying excess pressure to the ventilation openings 26.

For the process of ejecting remaining ink residues or the cleaning medium, the inkjet cracker is equipped with a suitable collecting device, e.g. an ink absorption pad or a suitable collecting container.

Following this cleaning process, the shut-off device 6 is set by the control device 24 such that the feed line 5 of that tank 3 with the ink of the new ink system is now brought into the open state, so that ink from the corresponding reservoir 9 into the distribution chamber 11 of the print head 2 can flow in. By actuating the corresponding pump 14, the ink is simultaneously conveyed from the corresponding tank 3 into the corresponding reservoir 9. As has already been described, the fill level of the distribution chamber 11 and the reservoir 9 is measured by means of the fill level sensors 25 and the control device 24 and is thus kept in a predetermined range.

It should be particularly pointed out that the individual parts of the ink jet printer 1 and the printer head 2 are shown to scale and in a simplified manner in FIG. 1. In particular, the volume of the tanks 3 and 4 in the specific and practical embodiment of a corresponding ink jet printing device is a multiple of the volume of the distribution chamber 11 of the print head 2 or the reservoirs 9. It should also be noted that the feeder lines 5, the return lines 10 as well the signal lines or the Supply lines between the control device 24 and the shut-off device 6 or the fill level sensor 25, the heating elements 22 and the thermometers 23 do not represent rigid connections, but that they are designed as flexible lines or connections. During the printing process, the dracking head 2 and the reservoirs 9 are sometimes at very high speeds as well as accelerations above what is to be printed

Print medium guided, so that it is advantageous that the tanks 3 and 4 and therefore the pumps 14 are attached to a part of the inkjet printer which is at rest opposite the print head 2.

A color of an ink system can be processed by a print head 2 as such. If the same print head 2 is part of an inkjet printing device 1, as shown in FIG. 1, it is possible to switch between different ink systems, i.e. to switch to the same color of another ink system. For a complete ink jet printer, it is, of course, necessary to have the same arrangement of a printhead 2 and the other components or elements as shown in FIG. 1 for each additional color to be processed

1 are to be provided. The tanks 3, the feeder lines 5, the reservoirs 9, the return lines 10, the shut-off elements 6, the pumps 14 and the filters 15 are designed to hold inks of different ink systems as well as different colors. Furthermore, the tank 4 and the corresponding feeder line 5, the corresponding pump 14 and the corresponding filter 15 are designed for a cleaning medium in the form of a cleaning liquid, but these parts can also be designed for receiving compressed air as a cleaning medium.

2 shows a drain head 2 with two reservoirs 9 and a feed opening 27 for a cleaning medium. The drain head 2 is via the feeder lines 5 with two

Tanks 3 for inks or a tank 4 for a cleaning medium connected.

At a first end region, the two reservoirs 9 of the drain head 2 are each connected to the connection opening 7 of a feed line 5 through a feed opening 8. At their second end region, the reservoirs 9 are connected by shut-off elements 6 to the distribution chamber 11 or an upper end region of the — in this exemplary embodiment eight — spray devices 12. The supply opening 27 for the cleaning medium is also connected to the upper end region of the spray devices 12 by a shut-off device 6. At their first end regions, the reservoirs 9 also each have a ventilation opening 26 equipped with an air filter. changes that dust particles penetrate into the print head 2 and cause a blockage in the nozzles 13.

As has already been explained in the figure description of FIG. 1, a pressure control circuit is preferably connected to the ventilation opening 3, through which the pressure inside the

Printhead 2 can be adjusted so that an erroneous leakage of ink through the nozzles 13, i.e. can be prevented without actuation of the spray device 12.

A pump 14 and a filter 15 are arranged in the feeder lines 5 of the tanks 3 for the inks and the tank 4 for the cleaning medium. The inks or the cleaning medium can be conveyed into the print head 2 by the pumps 14. The filters 15 can be used to prevent contaminants from the tanks 3 and 4 from getting into the print head 2. To control the inkjet cracking device 1, it is equipped with the control device 24. The control of the various operating states of the ink jet printer 1 can be automated or program-controlled as well as semi-automatic, i.e. by manually specifying parameters on a control panel (not shown), the control device 24 or by manually setting the various operating states.

In order to control the supply of ink or the cleaning medium, the control device 24 is connected to the pumps 14, to the shut-off elements 6 and to the level sensors 25. In order to keep the inks at the operating temperature required for them during processing, the tanks 3 or the drain head 2 are equipped with the heating elements 20 or 22 and the thermometers 21 or 23. These heating elements 20 and 22 as well as the thermometers are used to regulate the operating temperature of the inks

21 and 23 also in connection with the control device 24.

By opening one of the shut-off devices 6 of one of the two reservoirs 9, ink can flow from the reservoir 9 into the spraying devices 12, so that the supply of the spraying devices 12 with a corresponding ink of the corresponding ink system is ensured. The inflow of ink from the reservoir 9 into the area of the spray devices 12 is initially ensured in that pressure equalization can take place through the ventilation openings 26. If the fill level sensors 25, in cooperation with the control device 24, register a drop in the fill level in the reservoir 9, the corresponding pump 14 is controlled by the control device 24 in such a way that that a sufficient amount of ink is fed into the reservoir 9 from the corresponding tank 3.

In a further embodiment of the print head according to FIG. 2, it is advantageously also possible to design the shut-off elements 6 by means of a common multi-way valve.

The ink is ejected through the nozzles 13 in the lower end region of the spray devices 12 in a manner known per se by actuating the spray devices through corresponding data lines (not shown) or a corresponding control device (not shown) of the ink jet printer.

For this purpose, the spraying devices 12 are equipped with an actuator 28 and a liquid diode 29. The actuator 28 can be designed as an electrorestrective element, which is arranged on an outside of a housing wall of the nozzle head 2 which is elastically deformable in the region of the spraying device 12. If an electrical voltage is applied to the actuator 28 designed as an electrorestrective element, a pressure pulse is thereby exerted on the ink located in the area of the spraying device, so that the ink moves on the one hand in the direction of the nozzle 13 and on the other hand in the direction of the liquid diode 29 becomes. By means of the liquid diode 29, however, the movement of the ink from the actuator 28 in the direction of the liquid diode 29 is largely suppressed, so that the resultant effect is that a drop of the ink is expelled from the nozzle 13 onto the printing medium to be printed. As an alternative to this, it is also possible to design the actuator 28 by means of a corresponding heating element in such a way that the ink in the region of the spraying device 12 heats up to such an extent that a bubble of vaporous ink is formed, which ultimately leads to the ejection of a drop of the ink from the Nozzle 13 leads. The actuator 28 can of course also be changed by another physical effect, e.g. electrostatic, causing the ink to eject.

If the ink jet cracking device is to be converted to the processing of inks of another ink system, the shut-off devices 6 of the ink reservoirs 9 are first closed and the shut-off device 6 assigned to the feed access opening 27 is opened for the supply of a cleaning medium. The control device 24 then controls the pump 14 assigned to the tank 4 such that the cleaning medium is conveyed into the nozzle 2 and through the spray devices 12 and the nozzles 13. As a result, the ink remaining in the area of the spray devices 12 and the nozzles 13 Remnants removed from the nozzle 2 and cleaned these areas. In addition to cleaning with a cleaning medium in the form of a cleaning liquid, it is also additionally possible for compressed air to be blown into the print head 2 by the pump 14, so that the spray devices 12 and the nozzles 13 are also freed of the remaining residues of the cleaning liquid.

As already explained in the figure description of FIG. 1, the inkjet printer is a corresponding collecting device for the described process of ejecting remaining ink residues or the cleaning medium, e.g. an ink absorption pad or a suitable collecting container.

Following the described cleaning process, the corresponding shut-off device for the ink of the new ink system is now opened by the control device 24, so that it can flow into the spraying devices 12 and the nozzles 13. Thus, the ink jet stretching device is set to process inks of the new ink system. For ink jet printing devices with which more than one color is to be processed for different ink systems, it is of course necessary that a device with the elements, as shown in FIG. 2, is formed for each of the colors. It is of course also possible that only one common control device 24 is provided.

As was stated in the description of the figures in FIG. 1, it should also be emphasized here that the individual parts are shown to scale and in a simplified manner. The volumes of the tanks 3 and 4 in the specific and practical embodiment in a corresponding ink jet printing device are a multiple of the volumes of the reservoirs 9 of the drain head 2. Likewise, the feeder lines 5 and the various connections between the control device 24 and the shut-off devices 6, the pumps 14 and the heating elements 20 and 22 and the thermometers 21 and 23 and the level sensors 25 are flexible.

FIG. 3 shows a detail of an inkjet printer with three inkjet printing devices 1, according to FIG. 2 in a perspective and greatly simplified representation.

A draining medium 36 is moved in a direction 38 by a transport device 37 consisting of rollers. Three drain heads 2 are fastened in a slide 39, so that these in can be moved a short distance above the print medium 36 in the transverse feed direction, ie in a direction 40 perpendicular to the direction 38 of the movement of the print medium 36. To move the slide 39 in the transverse feed direction (direction 40), it is guided along two transverse guide path 41. During this movement of the print heads 2 over the print medium 36, the print medium 36 is covered with the ink ejected from the print heads 2. For this purpose, the ink is conveyed from the corresponding tanks 3 through the pumps 14 and the feed lines 5 into the print heads 2. The feeder lines 5 as well as the data and control lines (not shown) are routed through a flexible line channel 42 in a manner known per se. One end region of the conduit 42 is attached to a fixed part of the frame (not shown) of the inkjet printer, while the second end region of the conduit 42 is attached to the chute 39.

In order to keep the inks in the feed line 5 at the required operating temperature, they are connected to a heating element (not shown) and a thermometer (not shown). Of course, it is also possible for the feeder lines 5 to be connected to a common heating element and / or a common thermometer, in particular over the course of the line channel 42.

In modern inkjet printers with high printing performance, very high accelerations sometimes occur when the carriage 39 moves with the print heads 2. The acceleration forces thereby acting on the ink in the print heads 2 can lead to undesirable pressure fluctuations of the ink in the spraying devices 12 or in the nozzles 13 (FIG. 1, FIG. 2). As a result, the volumes of the ink droplets ejected through the nozzles 13 fluctuate, or air is sucked in or leaks out

Ink and thus affect the image quality. To avoid corresponding pressure fluctuations, the fact that the distribution chamber 11 or the reservoirs 9 are designed with ventilation openings 26 or to which ventilation pressure openings 26 are connected, as already mentioned in the figure descriptions in FIGS. 1 and 2. Through these ventilation openings 26, pressure equalization with the ambient air pressure is possible. To avoid pressure differences between different spray devices 12 of a print head 2 (this is a system of communicating vessels), the spray devices 12 or the nozzles 13 are also aligned perpendicular to the direction 40, ie perpendicular to the transverse feed direction of the carriage 39 , Finally, as a third measure to avoid fluctuations in pressure, hen that the feeder lines 5 and the return lines 10 as well as the lines between the shut-off device 6 and the drain head 2 are formed from an elastically resettable deformable material. In particular, the lines mentioned are designed to be resiliently deformable with a predeterminable force in the radial direction.

With the inkjet printing devices 1, according to FIG. 1 or FIG. 2, it is possible to produce inkjet crackers which enable simple retrofitting for processing inks of different ink systems. By designing inkjet printers with inkjet printer devices 1 according to the invention, the corresponding inkjet printers can be used universally with very short changeover times. The other elements of such an inkjet printer are, on the one hand, a transport device for a print medium 36 to be printed and, on the other hand, a transport device or a drive for moving the print heads 2 over the print medium 36. A corresponding inkjet printer also has a control device which is connected to the drives for the transport device for the drain medium 36 and the transport device for nozzle heads 2 or the slide 39 is connected and on the other hand via a system of data lines or via a data network, which can be controlled by the control device, the print heads 2 such that the corresponding image from the image information data the printing medium 36 to be printed can be applied. In the case of inkjet printers with a large number of print heads 2, it is of course also possible for a plurality of print heads 2 to process the same color. For this purpose, it is also possible for tanks 3 of a plurality of ink jet printing devices 1 for inks of the same ink system and of the same color to be formed by common tanks 3.

For the sake of order, it should finally be pointed out that for a better understanding of the

Construction of the inkjet printing device or the Drackkopf this / this or its / its components were partially shown to scale and / or enlarged and / or reduced.

The object on which the independent inventive solutions are based can be found in the description.

Above all, the individual in FIGS. 1; 2; 3 shown embodiments form the subject of independent, inventive solutions. The relevant tasks and solutions according to the invention can be found in the detailed descriptions of these figures. Regarding signs

Ink jet cracking device Drackkopf tank tank feed line shut-off device connection opening feed opening reservoir return line distribution chamber spraying device nozzle pump filter pump shut-off device shut-off device heating element thermometer heating element thermometer control device level sensor ventilation opening supply opening actuator liquid diode

Drackmedium Transport device in the direction of the carriage in the direction of the cross guide rail line

Claims

Patent claims

1. Ink jet cracking device with at least one print head, characterized in that a connection opening (7) for the drain head (2) is preceded by a plurality of tanks (3, 4) for inks and / or a cleaning medium and the tanks (3, 4) by feeder lines ( 5) are connected to the connection opening (7) for the drain head (2), a shut-off device (6) being arranged between each tank (3, 4) and the connection opening (7).

2. Ink jet cracking device according to spoke 1, characterized in that a reservoir (9) is arranged in the feeder line (5) between the shut-off device (6) and the tank (3, 4).

3. Inkjet printing device according to spoke 1 or 2, characterized in that the reservoir (9) is designed as a pressure expansion tank and / or for applying under-pressure.

4. The ink jet cracking device according to one of the preceding claims, characterized in that at least one reservoir (9) is arranged in the print head (2).

5. Inkjet printing device according to one of the preceding claims, characterized in that the shut-off element (6) is designed as a multi-way valve.

6. Inkjet printing device according to one of the preceding claims, characterized in that a pump (14) is arranged between each tank (3, 4) and the connection opening (7).

7. Inkjet printing device according to one of the preceding claims, characterized in that a filter (15) is arranged between each tank (3, 4) and the connection opening (7).

8. Ink jet cracking device according to one of the preceding claims, characterized in that a shut-off element (17) is arranged in the feed line (5) between each tank (3) and the reservoir (9) connected to it.

9. Inkjet printing device according to one of the preceding claims, characterized characterized in that a shut-off device (18) is arranged in the return line (10) between each tank (3) and the reservoir (9) connected to it.

10. Inkjet printing device according to one of the preceding claims, characterized in that the tanks (3, 4) for the inks and / or the reservoirs (9) and / or the

Drackkopf (2) with a heating element (20, 22) and / or a thermometer (21, 23) are formed.

11. The ink jet cracking device according to one of the preceding claims, characterized in that the tanks (3, 4) are formed with a common heating element (20) and / or a common thermometer (21).

12. The ink jet cracking device according to one of the preceding claims, characterized in that the feeder lines (5) are connected to a heating element and / or a thermometer.

13. An ink jet cracking device according to one of the preceding claims, characterized in that a plurality of feeder lines (5) is assigned a common heating element and / or a common thermometer.

14. The inkjet cracking device according to one of the preceding claims, characterized in that the dracking head (2) is designed with a heating element (22) and / or a thermometer (23).

15. Inkjet printing device according to one of the preceding claims, characterized in that the tanks (3, 4), the feed lines (5), the reservoirs (9), the shut-off elements (6), the pumps (14, 16) and the filters ( 15) are designed to hold inks of different ink systems and / or different colors.

16. The ink jet cracking device according to one of the preceding claims, characterized in that the tanks (3, 4), the feed lines (5), the reservoirs (9), the shut-off elements (6), the pumps (14, 16) and the filters ( 15) are designed for the absorption of a cleaning liquid and / or compressed air as a cleaning medium.

17. An ink jet cracking device according to one of the preceding claims, characterized characterized in that a fill level sensor (25) is arranged in an interior of the reservoir (9) and / or the tank (3, 4) and / or a distribution chamber (11) for the inks.

18. The ink jet cracking device according to one of the preceding claims, characterized in that the fill level sensor (25) is in an upper end region of the reservoir

(9) and / or the tanks (3, 4) and / or the distribution chamber (11) is arranged.

19. The ink jet cracking device according to one of the preceding claims, characterized in that the reservoir (9) for the inks is designed with at least one ventilation opening (26).

20. Inkjet printing device according to one of the preceding claims, characterized in that the distribution chamber (11) of the drain head (2) is formed with at least one ventilation opening (26).

21. Inkjet printing device according to one of the preceding claims, characterized in that a pressure control valve, in particular a servo valve, is arranged in the ventilation opening (26).

22. Inkjet printing device according to one of the preceding claims, characterized in that a pressure control circuit is connected to the ventilation opening (26).

23. The ink jet cracking device according to one of the preceding claims, characterized in that an air filter is arranged in the ventilation opening (26).

24. The ink jet cracking device according to one of the preceding claims, characterized in that the feed line (5) is designed to be resiliently deformable.

25. Inkjet printing device according to one of the preceding claims, characterized in that the feed line (5) with a predetermined force in radial

Is formed elastically resettable deformable.

26. The ink jet cracking device according to one of the preceding claims, characterized in that the reservoir (9) is connected to the tank (3, 4) by a return line (10) and a pump (16).

27. The ink jet cracking device according to one of the preceding claims, characterized in that tanks (3, 4) are connected to a plurality of drain heads via independent shut-off devices (6).

28. The ink jet cracking device according to one of the preceding claims, characterized in that the shut-off elements (6, 17, 18) and / or the pumps (14, 16) and / or the level sensors (25) and / or the heating elements (20, 22) and / or the thermometers (21, 23) are connected to a control device (24).

29. The ink jet stretching device according to one of the preceding claims, characterized in that the control device (24) is designed to control the filling of the distribution chamber (11) and / or the reservoirs (9) with ink.

30. The ink jet cracking device according to one of the preceding claims, characterized in that the control device (24) is designed to fill the tanks (3) with ink and / or to fill the tanks (4) with cleaning medium.

31. Printhead for ink jet printing devices, characterized in that several reservoirs (9) for inks and / or a cleaning medium, each with a feed opening (8, 27) at a first end region of the reservoirs (9) and a shut-off device (6) between one second end region of the reservoirs (9) and a distribution chamber (11) or a spray device (12) are formed.

32. Printhead according to claim 31, characterized in that the reservoir (9) for the inks is formed with at least one ventilation opening (26).

33. Drackkopf according spoke 31 or 3, characterized in that a pressure control valve, in particular a servo valve, is arranged in the ventilation opening (26).

34. Printhead according to one of the preceding claims, characterized in that a pressure control circuit is connected to the ventilation opening (26).

35. Printhead according to one of the preceding claims, characterized in that an air filter is arranged in the ventilation opening (26).

36. Drackkopf according to any one of the preceding claims, characterized in that the drackkopf (2) with a heating element (22) and / or a thermometer (23) is formed.

37. Printhead according to one of the preceding claims, characterized in that the reservoirs (9), the distribution chamber (11), the shut-off elements (6) and the spraying device (12) are designed to hold inks of different ink systems and different colors.

38. Drackkopf according to any one of the preceding claims, characterized in that the reservoirs (9), the distribution chamber (11), the shut-off elements (6) and the spray device (12) for receiving a cleaning liquid and / or compressed air as a cleaning medium are.