Device and method for adjusting a pressure bolt

Abstract

A device (101) for adjusting the height of a print bar (102) of an inkjet printer (100) is described, wherein the printer (100) has a cleaning carriage (153) for cleaning the one or more printheads (103) of the print bar (102). The device (101) is configured to determine distance information regarding the distance (201) between the cleaning carriage (153) and the print bar (102) at different measuring points using a sensor unit (200, 210), and to adjust the height of the print bar (102) depending on the determined distance information. This allows for precise adjustment of the print bar (102) for high-quality and gentle cleaning.

Description

[0001] The invention relates to a method and a device for adjusting a printing bar, in particular the height of a printing bar, of an inkjet printing device, in particular to enable reliable cleaning of one or more print heads of the printing bar.

[0002] An inkjet printing device for printing on a recording medium may comprise at least one print bar with one or more print heads, each print head typically having a plurality of nozzles. The nozzles are each configured to eject ink droplets to print pixels of a print image onto the recording medium.

[0003] During printing, a print head typically becomes contaminated with ink, aerosols, and / or components of the recording medium. Furthermore, the ink in a print head dries during operating phases when printing is not taking place. Contamination of the print head and / or drying of the ink can lead to impaired print quality and / or the failure of individual print head nozzles.

[0004] To clean a print head of a print bar and / or to remove dried or dried-on ink, one or more of the print head's nozzles can be flushed with ink during a cleaning process. Furthermore, the print head's nozzle plate can be wiped with a wiper.

[0005] The document US 2014 / 0 111 576 A1 describes a printing unit comprising a movable print head with a nozzle plate having a plurality of nozzles for ejecting liquid ink; a cleaning station having a cleaning surface with at least one suction element for generating an air suction; wherein the cleaning station is configured to clean the nozzles when the print head overlaps the cleaning station, such that the nozzle plate and the cleaning surface at least partially overlap.

[0006] The document US 2022 / 0 176 706 A1 describes a printing device comprising a reservoir for cleaning fluid, a line for the cleaning fluid supply, one or more electrical connectors configured to be connected to a print head and to supply electrical signals to the print head, one or more memories and one or more processors in communication with the one or more memories.

[0007] The document US 2021 / 0 373 437 A1 describes a method for checking a dispenser comprising a front plate, wherein a sensor is moved over the front plate while the distance between the sensor and the front plate is measured.

[0008] This document addresses the technical problem of reliably enabling gentle cleaning and consistently high cleaning quality of one or more print heads of a print bar of an inkjet printing device. This problem is solved by the features of independent device claim 1. Furthermore, the problem is solved by the features of independent method claim 10.

[0009] According to one aspect of the invention, a device for adjusting a printing bar of an inkjet printing device is described, wherein the printing device comprises a cleaning carriage for cleaning nozzle plates of the one or more print heads of the printing bar, and wherein the cleaning carriage is movable along a cleaning direction from a first side to a second side of the printing bar.

[0010] The device is configured to use at least one sensor unit to determine distance information regarding the distance between the cleaning carriage and the pressure bar at at least two different measuring points along the cleaning direction. The device is further configured to adjust the distance between the cleaning carriage and the pressure bar based on the distance information using at least one alignment element.

[0011] According to a further aspect, a method for adjusting a printing bar of an inkjet printing device is described, wherein the printing device comprises a cleaning carriage of the printing bar and wherein the cleaning carriage can be moved along a cleaning direction from a first side to a second side of the printing bar.

[0012] The method comprises determining, using at least one sensor unit, distance information relating to the distance between the cleaning carriage and the pressure bar at at least two different measuring points along the cleaning direction. Furthermore, the method comprises adjusting, using at least one alignment element, the distance between the cleaning carriage and the pressure bar depending on the distance information.

[0013] In the following, exemplary embodiments of the invention are described in more detail with reference to the schematic drawings. In the drawings: Fig. 1a is a block diagram of an exemplary inkjet printing device; Fig. 1b shows an exemplary regeneration device of an inkjet printing device in a view from below; Fig. 1c shows an exemplary regeneration device of an inkjet printing device in a side view; Fig. 2 an excerpt from Fig. 1c; and Fig. 3 is a flowchart of an exemplary method for adjusting a print bar of an inkjet printing device.

[0014] The Fig. The printing device 100 shown in Figure 1a is designed for printing on a sheet-, sheet-, plate-, or tape-shaped recording medium 120. The recording medium 120 can be made of paper, cardboard, carton, metal, plastic, textiles, a combination thereof, and / or other suitable and printable materials. The recording medium 120 is transported along the transport direction 1 (represented by an arrow) through the printing unit 140 of the printing device 100.

[0015] In the illustrated example, the printing unit 140 of the printing device 100 comprises two printing bars 102, wherein each printing bar 102 can be used for printing with ink of a specific color, such as black, cyan, magenta, and / or yellow, and possibly MICR ink. Furthermore, the printing device 100 typically comprises at least one fixing or drying unit (not shown) configured to fix a print image printed on the recording medium 120.

[0016] A printing bar 102 may comprise one or more print heads 103, which may be arranged in several rows next to one another, in order to print the pixels of different columns 31, 32 of a print image onto the recording medium 120. In the Fig. In the example shown in Figure 1a, a printing bar 102 comprises five print heads 103, each print head 103 printing the pixels of a group of columns 31, 32 of a print image onto the recording medium 120.

[0017] Each print head 103 of the printing unit 140 comprises in the Fig. 1a, a plurality of nozzles 21, 22, each nozzle 21, 22 being configured to fire or impinge ink droplets onto the recording medium 120. A print head 103 of the printing unit 140 can, for example, comprise several thousand effectively used nozzles 21, 22 arranged along several rows transversely to the transport direction 1 of the recording medium 120. By means of the nozzles 21, 22 of a print head 103 of the printing unit 140, pixels of a line of a print image can be printed onto the recording medium 120 transversely to the transport direction 1, i.e., along the width of the recording medium 120.

[0018] The printing device 100 further comprises a control device 101 (e.g., a control hardware and / or a controller) which is configured to control the actuators of the individual nozzles 21, 22 of the individual print heads 103 of the printing unit 140 in order to apply the print image to the recording medium 120 as a function of print data.

[0019] The printing unit 140 of the printing device 100 thus comprises at least one printing bar 102 with N nozzles 21, 22, which can be controlled with a specific line clock to print a line, which runs transversely to the transport direction 1 of the recording medium 120, with N pixels or N columns 31, 32 of a print image on the recording medium 120 (with N>1000). In the example shown, the nozzles 21, 22 are immovably or permanently installed in the printing device 100, and the recording medium 120 is guided past the stationary nozzles 21, 22 at a specific transport speed along the transport direction 1.

[0020] Furthermore, the printing device 100 comprises one or more regeneration devices 150 for the one or more printing bars 102. A printing bar 102 can be transferred from a printing position, at which the printing bar 102 is arranged above the recording medium 120, into a cleaning or maintenance position. For this purpose, the printing bar 102 can be moved in the direction of movement 2 indicated by an arrow, wherein the direction of movement 2 can run perpendicular to the transport direction 1. The nozzle plates of the one or more print heads 103 of a printing bar 102 can then be cleaned, e.g., wiped, in the cleaning or maintenance position using a regeneration device 150. The printing device 100 can have at least or exactly one regeneration device 150 for each printing bar 102.

[0021] Fig. 1b shows a view of the regeneration device 150 from below onto the nozzle plates 180 of two print heads 103 of a print bar 102, and Fig. 1c shows a side view of the regeneration device 150, with a print bar 102 with three print heads 103. The print heads 103 are arranged one behind the other along a cleaning direction 160. The cleaning direction 160 typically runs parallel to the direction of movement 2. The outlets or nozzle openings of one or more nozzles 21, 22 of the print head 103 are arranged on the underside or on the nozzle plate 180 of a print head 103.

[0022] In the cleaning or maintenance position, the one or more nozzles 21, 22 of the print head 103 can be caused to eject ink, e.g., by increasing the pressure within the one or more nozzles 21, 22. This step is typically referred to as "purging." Furthermore, the nozzle plate 180 of a print head 103 can be sprayed with a (cleaning) liquid 156 by one or more spray nozzles 155. Subsequently, the underside or nozzle plate 180 of a print head 103 can be cleaned with a wiper 151. The wiper 151 can be moved along the cleaning direction 160 over the nozzle plate 180 of a print head 103 in order to clean the nozzle plate 180 of any ink remaining on the nozzle plate 180. This step is typically referred to as "wiping."

[0023] The wiper 151 and / or a spray nozzle 155 can be attached (separately or together) to a cleaning carriage 153, which is guided along a guide rail 154 on the nozzle plate 180 of a print head 103. A carriage 153 can guide one or more wipers 151 over the nozzle plates 180 of several (in particular all) print heads 103 of a print bar 102. The liquid wiped away can drip into a tray (not shown), which is arranged below the carriage 153. After the nozzle plates 180 of the one or more print heads 103 have been wiped, the wiper 151 can be moved into a cleaning module 152, in which the wiper 151 is cleaned.

[0024] The pressure bar 102 can be designed such that the inclination of the pressure bar 102 can be changed along the cleaning direction 160, i.e., transversely to the transport direction 1. The pressure bar 102 can extend along the cleaning direction 160 from a first side 171 to an opposite second side 172. An alignment element 170 can be arranged on each of the two sides 171, 172, with which the pressure bar 102 can be aligned. In particular, the alignment elements 170 can each be designed to change the height of the respective side 171, 172 of the pressure bar 102 along a height direction, wherein the height direction runs perpendicular to the cleaning direction 160 and perpendicular to the transport direction 1. The alignment elements 170 can each comprise an electric motor, in particular a stepper motor.

[0025] The alignment element 170 on the first side 171 of the pressure bar 102 can be used to increase or decrease the height of the first side 171 of the pressure bar 102, and thus move the pressure bar 102 on the first side 171 away from the cleaning carriage 153 or toward the cleaning carriage 153. Similarly, the alignment element 170 on the second side 172 of the pressure bar 102 can be used to increase or decrease the height of the second side 172 of the pressure bar 102, and thus move the pressure bar 102 on the second side 172 away from the cleaning carriage 153 or toward the cleaning carriage 153. Thus, the inclination of the pressure bar 102 along the cleaning direction 160 can be changed.Furthermore, the distance between the cleaning carriage 153 and the printing bar 102, in particular between the wiper 151 arranged on the cleaning carriage 153 and the nozzle plates 180 of the one or more print heads 103 of the printing bar 102, can be changed.

[0026] To ensure a consistently high cleaning quality of the nozzle plates 180 of the one or more print heads 103, the force with which the wiper 151 acts on the nozzle plates 180 should be constant along the entire cleaning direction 160, from the first side 171 to the second side 172 of the print bar 102. This can be achieved by maintaining a constant distance along the height direction between the wiper 151 or the carriage 153 and the nozzle plates 180 along the entire cleaning direction 160, from the first side 171 to the second side 172 of the print bar 102. This can in turn be achieved by adjusting the inclination of the print bar 102 using the one or more alignment elements 170.

[0027] Fig. 2 shows an excerpt from Fig. 1c. At least one sensor unit 200, 210 is arranged on the carriage 153 of the wiper 151, which is designed to detect distance information relating to the distance 201 between the carriage 153 or the wiper 151 and the print bar 102 or the one or more print heads 13.

[0028] The sensor unit 200, 210 can, for example, comprise a distance sensor 200 configured to directly detect the distance 201. A reference element 202 can be arranged on the underside of the print bar 102 or a print head 103 facing the distance sensor 200. This reference element 202 can optionally be configured to reflect a measurement signal emitted by the distance sensor 200 in a defined manner in order to enable a particularly precise distance measurement. The distance sensor 200 can be configured to detect the distance 201 between the carriage 153 and the reference element 202. Exemplary distance sensors 200 are ultrasound-based, optical, inductive, and / or capacitive.

[0029] Alternatively or additionally, the sensor unit 200, 210 can comprise a force and / or pressure sensor 210 configured to detect the force or pressure with which the wiper 151 acts on the nozzle plate 180 of a print head 103. The force or pressure is typically higher the closer the carriage 153 with the wiper 151 is arranged to the nozzle plate 180. Consequently, the distance 210 between the nozzle plate 180 and the carriage 153 can be determined from the detected force or pressure. The pressure or force with which the wiper 151 acts on the nozzle plate 180 of a print head 103 thus represents distance information with respect to the distance 201.

[0030] The (control) device 101 of the inkjet printing device 100 can be configured to use the sensor unit 200, 210 to determine distance information relating to the distance 201 between the carriage 153 or the wiper 151 and the printing bar 102 on the first side 171 of the printing bar 102. Furthermore, the sensor unit 200, 210 can be used to determine distance information relating to the distance 201 between the carriage 153 or the wiper 151 and the printing bar 102 on the second side 172 of the printing bar 102. The alignment elements 170 can then be operated depending on the determined distance information in order to align the pressure bar 102 along the cleaning direction 160 such that the distance 201 between the wiper 151 and the pressure bar 102 remains constant along the entire cleaning direction 160, from the first side 171 to the second side 172 of the pressure bar 102, and optionally has a defined value.This allows for a consistently high cleaning quality to be achieved efficiently and reliably. Furthermore, it allows for gentle cleaning of the individual print heads 103, thereby increasing the service life of the print heads 103.

[0031] The printing bar 102 can have a plurality of print heads 103 arranged one behind the other along the cleaning direction 160. Following the alignment of the printing bar 102 along the cleaning direction 160, distance information relating to the distance 201 between the wiper 151 and the nozzle plates 180 of the individual print heads 103 can be detected using the sensor unit 200, 210. In particular, it can be checked whether the individual print heads 103 have a uniform distance 201. If a print head 103 has a deviating distance 201, it can be concluded that this print head 103 is incorrectly installed in the printing bar 102. One or more measures can then be initiated, such as the output of a message via the user interface of the printing device 100, which cause the incorrect installation of the print head 103 to be corrected. The print quality of the printing device 100 can thus be improved.

[0032] In order to enable correct, reproducible, and operator-independent height adjustment of the print bar 102, a sensor 200, 210 can be installed on the carriage 153 of the wiper 151, which is designed to determine the distance 201 between the carriage 153 and the surface 180 of the one or more print heads 103 being cleaned. The carriage 153 can be moved to a first position, and the sensor 200, 210 measures the distance 201 at the first position. The first position can be arranged on the first side 171 of the print bar 102. Subsequently, the wiper carriage 153 can be moved to a second position, and the sensor 200, 210 measures the distance 201 at the second position. The second position can be arranged on the second side 172 of the print bar 102.

[0033] The distance measurements can be evaluated, and if it is determined that the distance 201 between the carriage 153 and the one or more print heads 103 is incorrect, the height of the print bar 102 on the first side 171 and / or on the second side 172 of the print bar 102 can be adjusted accordingly using the alignment elements 170. The process can be repeated if necessary until the height is correctly adjusted. Alternatively or in addition to measuring the distance, the pressure exerted by the individual print heads on the wiper 151 can be measured.

[0034] By correctly adjusting the wiper 151, the cleaning quality, print quality, and service life of the one or more print heads 103 can be increased. In particular, optimal contact of the wiper 151 with the surface 180 of the one or more print heads 103 can be achieved in order to remove liquid 156 and / or ink from the surface 180. Furthermore, the wiper 151 can be caused to act on the surface 180 of the one or more print heads 103 with a defined force, thus preventing damage to the coating of the surface 180 of the one or more print heads 103.

[0035] Fig.3 shows a flowchart of an exemplary, possibly computer-implemented, method 300 for adjusting a print bar 102 of an inkjet printing device 100 having one or more print heads 103. The method 300 can be configured, in particular, to adjust the height of the print bar 102 along the height direction and / or the inclination of the print bar 102 along the cleaning direction 160. The method 300 can be performed while the print bar 102 is arranged at the maintenance and / or cleaning position.

[0036] The printing device 100 has a cleaning carriage 153 for cleaning the nozzle plates 180 of the one or more print heads 103. A wiper 151 for wiping the nozzle plates 180 of the one or more print heads 103 can be arranged on the cleaning carriage 153. Furthermore, a sensor unit 200, 210 can be arranged on the cleaning carriage 153. The cleaning carriage 153 can be movable along the cleaning direction 160 from the first side 171 to the opposite second side 172 of the printing bar 102. The first print head 103 can be arranged on the first side 171 and the last print head 103, e.g., the K, can be arranged on the second side 172. te , print head 103 of the print bar 102 may be arranged.

[0037] The method 300 comprises determining 301, using the at least one sensor unit 200, 210, distance information relating to the distance 201 between the cleaning carriage 153 and the print bar 102, in particular between the cleaning carriage 153 and the nozzle plate 180 of a print head 103, at at least two different measuring points along the cleaning direction 160. A first measuring point can be arranged on the first side 171 of the print bar 102 and a second measuring point can be arranged on the second side 172 of the print bar 102. The sensor unit 200, 210 can be moved together with the cleaning carriage 153 along the cleaning direction 160 to the respective measuring point in order to determine the respective distance information.

[0038] The method 300 further comprises adjusting 302, using at least one alignment element 170, the distance 201 between the cleaning carriage 153 and the pressure bar 102 as a function of the distance information, in particular such that after the adjustment the distances 201 between the cleaning carriage 153 and the pressure bar 102 are equal on the first side 171 and on the second side 172 of the pressure bar 102.

[0039] This document thus describes a device 101 for adjusting a print bar 102 with one or more print heads 103 of an inkjet printing device 100. The printing device 100 comprises a cleaning carriage 153 for cleaning the nozzle plates 180 of the one or more print heads 103. For this purpose, a wiper 151 can be arranged on the cleaning carriage 153. The cleaning carriage 153 can be moved along the cleaning direction 160 from a first side 171 to a second side 172 of the print bar 102, e.g., in order to wipe the nozzle plates 180 of the one or more print heads 103 with the wiper 151. The cleaning direction 160 can run perpendicular to the transport direction 1.

[0040] The device 101 is configured to use at least one sensor unit 200, 210 to determine distance information relating to the distance 201 between the cleaning carriage 153 and the print bar 102 at at least two different measuring points along the cleaning direction 160. The distance information can, in particular, indicate the distance 201 between the cleaning carriage 153 and the nozzle plate 180 of the print head 103 arranged at the respective measuring point. The sensor unit 200, 210 can be configured to be moved together with the cleaning carriage 153. For this purpose, the sensor unit 200, 210 can be attached to the cleaning carriage 153.

[0041] The sensor unit 200, 210 may comprise a distance sensor 200 configured to acquire sensor data relating to the distance 201 between the distance sensor 200 and the print bar 102, in particular the nozzle plate 180 of a print head 103. In this case, the distance information may comprise sensor data of the distance sensor 200 or at least be based on this sensor data.

[0042] Alternatively or additionally, the sensor unit 200, 210 can comprise a pressure sensor 210 configured to record sensor data relating to the pressure exerted by the wiper 151 arranged on the cleaning carriage 153 on the nozzle plate 180 of the print head 103 of the print bar 102 at the respective measuring point. In this case, the distance information can comprise sensor data, in particular pressure measurement values, of the pressure sensor 210 or be based on this sensor data. Different pressure measurement values ​​at the different measuring points indicate that the distances 201 between the cleaning carriage 153 and the print bar 102 are different at the different measuring points. By using a pressure sensor 210, the distance information can be determined in a particularly efficient and precise manner.

[0043] The device 101 can be configured to use the sensor unit 200, 210 to determine distance information relating to the distance 201 between the cleaning carriage 153 and the printing bar 102 at a first measuring point on the first side 171 and at a second measuring point on the second side 172 of the printing bar 102. The printing bar 102 can, for example, comprise, if necessary, precisely, K print heads 103, with K≥2, which are arranged one behind the other along the cleaning direction 160. The first print head 103 can be arranged on the first side 171 of the printing bar 102 and the K te Print head 103 can be arranged on the opposite second side 172 of the print bar 102. Thus, distance information relating to the distance 201 between the cleaning carriage 153 and the nozzle plate 180 of the first print head 103 and distance information relating to the distance 201 between the cleaning carriage 153 and the nozzle plate 180 of the K tenPrint head 103 can be determined. By taking into account distance information from measuring points arranged on the opposite sides 171, 172 of the print bar 102, a particularly precise adjustment of the print bar 102 can be achieved.

[0044] The device 101 is further configured to adjust the distance 201 between the cleaning carriage 153 and the pressure bar 102 based on the distance information using at least one alignment element 170. In particular, the inclination of the pressure bar 102 along the cleaning direction 160 can be adjusted, in particular changed, based on the distance information using the alignment element 170.The distance 201 between the cleaning carriage 153 and the printing bar 102 can be set as a function of the distance information such that the distance 201 between the cleaning carriage 153 and the printing bar 102, in particular between the cleaning carriage 153 and the nozzle plate 180 of the first print head 103, on the first side 171 of the printing bar 102 and the distance 201 between the cleaning carriage 153 and the printing bar 102, in particular between the cleaning carriage 153 and the nozzle plate 180 of the K. ten Print head 103, on the second side 172 of the print bar 102, are at least substantially equal. This can be achieved, for example, if the distances 201 differ from each other by less than 10% or by less than 5%.

[0045] The cleaning carriage 153 is typically arranged vertically below the print bar 102, in particular below the nozzle plates 180 of the one or more print heads 103. The adjustment of the distance 201 can be achieved by changing the height of the print bar 102 using one or more alignment units 170. The one or more alignment units 170 can each comprise an electric motor, in particular a stepper motor.

[0046] The printing device 100 can, for example, have a first alignment element 170 on the first side 171 and a second alignment element 170 on the second side 172 of the printing bar 102. The device 101 can be configured to control the first and / or the second alignment element 170 depending on the distance information in order to adjust the distance 201 between the cleaning carriage 153 and the printing bar 102 and / or to adjust the inclination of the printing bar 102 along the cleaning direction 160. This allows for a particularly precise adjustment of the distance 201.

[0047] A device 101 for adjusting the height of a printing bar 102 of an inkjet printing device 100 is thus described, wherein the printing device 100 has a cleaning carriage 153 for cleaning the one or more print heads 103 of the printing bar 102. The device 101 is configured to use a sensor unit 200, 210 to determine distance information relating to the distance 201 between the cleaning carriage 153 and the printing bar 102 at different measuring points, and to adjust the height and / or inclination of the printing bar 102 depending on the determined distance information. This allows for precise adjustment of the printing bar 102 for high-quality and gentle cleaning. Furthermore, the print quality of the printing device 100 can be increased.

[0048] The print head 102 can comprise a first print head 103 and a different second print head 103. The device 101 can be configured to use the sensor unit 200, 210 to determine first distance information relating to the distance 201 between the cleaning carriage 153 and the nozzle plate 180 of the first print head 103. For this purpose, the cleaning carriage 153 with the sensor unit 200, 210 can be positioned below the nozzle plate 180 of the first print head 103. The device can further be configured to use the sensor unit 200, 210 to determine second distance information relating to the distance 201 between the cleaning carriage 153 and the nozzle plate 180 of the second print head 103. For this purpose, the cleaning carriage 153 with the sensor unit 200, 210 can be positioned below the nozzle plate 180 of the second print head 103.

[0049] Furthermore, the device 101 can be configured to detect, based on the first distance information and the second distance information, whether the first print head 103 and / or the second print head 103 are incorrectly installed in the print bar 102. If necessary, a notification can be issued to inform a user of the printing device 100 that a faultily installed print head 103 has been detected. This allows the print quality of the printing device 100 to be further improved.

[0050] The device can be configured to determine the first distance information and the second distance information in order to detect whether the first print head 103 and / or the second print head 103 are incorrectly installed in the print bar 102 before and / or after the distance 201 between the cleaning carriage 153 and the print bar 102 is or has been adjusted depending on the distance information determined at different measuring points. In particular, the inclination of the print bar 102 can first be adjusted before distance information for detecting a faultily installed print head 103 is acquired. In this way, a faultily installed print head 103 can be detected particularly reliably.

[0051] Furthermore, this document describes an inkjet printing device 100 which includes the control device 101 described in this document. List of reference symbols 1 Transport direction (of the recording medium) 2 Direction of movement (of a pressure bar) 21, 22 nozzle 31, 32 columns (of the print image) 100 printing device 101 Control unit 102 pressure bars 103 Printhead 120 recording media 140 printing units 150 Regeneration device 151 Cleaning unit (wiper) 152 Cleaning module 153 carriage / wiper holder 154 guide rail 155 application unit (spray nozzle) 156 (Cleaning) Liquid 160 Cleaning direction 170 Alignment element 171, 172 side of the pressure bar 180 nozzle plate 200 sensor unit (distance sensor) 201 distance 202 Reference element 210 Sensor unit (pressure sensor) 300 Procedure for adjusting a pressure bar 301-302 Procedural steps

Claims

[1] Device for adjusting a printing bar (102) with one or more print heads (103) of an inkjet printing device (100); wherein the printing device (100) comprises a cleaning carriage (153) for cleaning nozzle plates (180) of the one or more print heads (103); wherein the cleaning carriage (153) can be moved along a cleaning direction (160) from a first side (171) to a second side (172) of the printing bar (102); wherein the device (101) is configured - to determine distance information relating to a distance (201) between the cleaning carriage (153) and the pressure bar (102) at at least two different measuring points along the cleaning direction (160) using at least one sensor unit (200, 210); and - using at least one alignment element (170) to adjust the distance (201) between the cleaning carriage (153) and the pressure bar (102) as a function of the distance information, characterized by , that - the print bar (102) comprises a first print head (103) and a second print head (103); and - the device (101) is arranged -- to determine first distance information relating to the distance (201) between the cleaning carriage (153) and the nozzle plate (180) of the first print head (103) using the sensor unit (200, 210); -- to determine second distance information relating to the distance (201) between the cleaning carriage (153) and the nozzle plate (180) of the second print head (103) using the sensor unit (200, 210); and -- to detect on the basis of the first distance information and the second distance information whether the first print head (103) and / or the second print head (103) are incorrectly installed in the print bar (102). [2] Device according to claim 1, wherein the device (101) is configured to use the sensor unit (200, 210) to determine distance information relating to the distance (201) between the cleaning carriage (153) and the pressure bar (102) at a first measuring point on the first side (171) and at a second measuring point on the second side (172) of the pressure bar (102). [3] Device according to claim 2, wherein - the printing bar (102) comprises K printing heads (103), with K ≥ 2, which are arranged one behind the other along the cleaning direction (160); and - the first print head (103) on the first side (171) of the print bar (102) and the K tePrint head (103) is arranged on the opposite second side (172) of the print bar (102). [4] Device according to one of the preceding claims, wherein the device (101) is configured to adjust an inclination of the pressure bar (102) along the cleaning direction (160) based on the distance information by means of the alignment element (170). [5] Device according to one of the preceding claims, wherein - the printing device (100) has a first alignment element (170) on the first side (171) and a second alignment element (170) on the second side (172) of the printing bar (102); and - the device (101) is configured to control the first and / or the second alignment element (170) as a function of the distance information in order to adjust the distance (201) between the cleaning carriage (153) and the pressure bar (102) and / or the inclination of the pressure bar (102) along the cleaning direction (160). [6] Device according to one of the preceding claims, wherein the device (101) is arranged to adjust the distance (201) between the cleaning carriage (153) and the pressure bar (102) in dependence on the distance information such that the distances (201) between the cleaning carriage (153) and the pressure bar (102) on the first side (171) of the pressure bar (102) and on the second side (172) of the pressure bar (102) are the same. [7] Device according to one of the preceding claims, wherein the sensor unit (200, 210) comprises - a distance sensor (200) configured to detect sensor data relating to the distance (201) between the distance sensor (200) and the pressure bar (102); and / or - a pressure sensor (210) configured to detect sensor data relating to a pressure exerted by a wiper (151) arranged on the cleaning carriage (153) on the nozzle plate (180) of a print head (103) of the print bar (102). [8] Device according to claim 1, wherein the device (101) is configured to determine the first distance information and the second distance information in order to detect whether the first print head (103) and / or the second print head (103) are incorrectly installed in the print bar (102) before and / or after the distance (201) between the cleaning carriage (153) and the print bar (102) is or has been set as a function of the distance information determined at different measuring points. [9] Method for adjusting a printing bar (102) with one or more print heads (103) of an inkjet printing device (100); wherein the printing device (100) comprises a cleaning carriage (153) for cleaning nozzle plates (180) of the one or more print heads (103); wherein the cleaning carriage (153) can be moved along a cleaning direction (160) from a first side (171) to a second side (172) of the printing bar (102); wherein the method (300) comprises - determining (301), using at least one sensor unit (200, 210), distance information relating to a distance (201) between the cleaning carriage (153) and the pressure bar (102) at at least two different measuring points along the cleaning direction (160); and - adjusting (302), using at least one alignment element (170), the distance (201) between the cleaning carriage (153) and the pressure bar (102) as a function of the distance information, characterized by , that - the print bar (102) comprises a first print head (103) and a second print head (103); and - the device (101) is arranged -- to determine first distance information relating to the distance (201) between the cleaning carriage (153) and the nozzle plate (180) of the first print head (103) using the sensor unit (200, 210); -- to determine second distance information relating to the distance (201) between the cleaning carriage (153) and the nozzle plate (180) of the second print head (103) using the sensor unit (200, 210); and - to detect on the basis of the first distance information and the second distance information whether the first print head (103) and / or the second print head (103) are incorrectly installed in the print bar (102).

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