Print head module

[0001] The invention relates to a printhead module for a single pass inkjet printer that includes a housing and a number of printheads arranged along a transverse direction perpendicular to the direction of travel.

[0002] While in a traditional inkjet printer, printheads mounted on a sled, spray in a transverse direction, with lines, ink drops on the agent, transported discontinuously in the direction of travel, in the case of a single-pass inkjet printer the printheads are mounted in the head modules printers of the aforementioned type, across the entire width of the refrigerant. The printing medium can be moved continuously in the direction of travel. While traditional inkjet printers achieve print speeds up to 2 m per minute, print speeds up to 50 m per minute can be achieved with a single-pass inkjet printer. For single-color inkjet printing, several printhead modules are installed in the feed direction, one after the other. In this case, the base color is assigned to the printhead modules, especially cyan, magenta and yellow, and possibly black. Printhead modules with a special color can be added for specific printing inserts.

[0003] A single pass inkjet printer is particularly suitable for industrial use, in which large quantities of goods must be printed and therefore high throughput is involved. Thanks to the high printing speeds, the single-pass inkjet printer is also suitable for printing large area objects. Therefore, the single-pass inkjet printer is especially suitable for industrial applications in the furniture and ceramics industries, where floor coverings, such as laminates or cladding tiles, work boards, profile strips or the like should be ornamented. At the same time, various inks are used, which are, for example, resistant to the subsequent protective coating, and so on.

[0004] Compared to traditional printing methods, such as gravure printing or the like, a single pass inkjet printer is also just used for small batch sizes where it is not profitable to produce a printing roller. In contrast, the single-pass inkjet printer also allows you to customize ornaments and make impossible ornaments that are not possible with the help of rollers. A one-pass inkjet printer is not limited to constant repetition of a printing pattern or report, as is the case with roller printing.

[0005] The printhead module for a single-pass inkjet printer can reach transversely and vertically dimensions from above half to more than one meter. Individual printheads collected in the printhead of the printhead module can be up to several dozen cm wide. At the same time, resolutions up to 600 x 600 dpi (dots per inch) are possible. At the same time, several thousand nozzles are contained on the print head. Thanks to large printhead modules or by placing several printhead modules next to each other, print widths of up to several meters can be achieved.

[0006] With the help of the human eye, position deviations of kiika micrometers are visible in the printed image. In the case of the above resolutions, the individual printhead nozzles diverge only at several dozen pm. The size of the image point moves by itself within 10 pm. It is apparent that for a single-pass inkjet printer with multiple printhead modules positioned one after the other in the direction of travel, it is necessary to adjust the printheads in

ΕΡ 2 582 526 Β1 micrometer range to produce a high quality printed image. Therefore, adjusting the printhead module in a single-pass inkjet printer is labor intensive. The position of the printheads must be detected, for example, by means of an optical microscope and manually adjusted in a labor-intensive manner. In this way, the construction of a single-pass inkjet printer is relatively tedious.

Adjustment must also be made for each replacement of the printhead module. This leads to unnecessary extension of downtime.

[0007] The object of the invention is to indicate a printhead module for a single-pass inkjet printer that can be replaced quickly and easily. It should also be possible to make a single pass inkjet printer design with this type of printhead module as quickly as possible.

[0008] The said task is solved according to the invention by a printhead module of the aforementioned type, wherein the hanger part mounted on the housing is provided for suspension directed to the force of gravity and wherein the individual printheads located on the housing are adjustable with respect to at least one reference position.

[0009] In this respect, the invention is derived from the reasoning that the hanging mounting of printhead modules allows substantially easier mounting and dismounting in the vertical direction. The hanging printhead module can, for example, be removed from a fixed printing position in the device, especially pulled out, and brought to the cleaning or removal position, above or below the printing position, while the hanging position of the printhead module allows self-alignment based on gravity applied to the center of gravity . When using hanging printhead modules, rough positioning is already achieved for the subsequent print position constant in the device. As a result, the hanging attachment, especially without the laborious mechanical auxiliary structures, allows the printhead module to self-adjust to the fixed device of the printing position, without the need for final adjustment by hand. The assembly of any mechanical guide elements is simplified due to the automatic positioning of the hanging printhead module due to gravity compared to laborious forced guides.

[0010] On the sides of the single-pass inkjet printer, for example next to the hanger for the printhead module, supports or guide elements can be provided which, when inserted in the vertical direction, bring the printhead module to a fixed final printing position. The mechanical components provided for this are especially shaped so that only lowering or raising the printhead module leads to a fixed printing position. By lowering or raising the printhead module, it leaves the print position and can be returned to it easily, back and forth.

[0011] The printhead module, in particular next to the printheads, may simultaneously contain an electronic control device and optionally an ink tank. However, the invention is by no means limited to such relatively large shapes.

[0012] The hanger part is preferably shaped so that it is used in cooperation with a single pass inkjet printer as a fixed support or a bearing mounted slidably to fix the end position. The hanger part can in particular also be shaped so that it can be removed from the hanger in the vertical direction. In the final printing position, this allows the print head module to be mounted upright. Accordingly, in the case of a hanging insertion, the center of gravity of the printhead module is below the support point of the hanger or the hanger part. However, in

ΕΡ 2 582 526 Β1 obtained, fixed in the device, printing position in the case of upright mounting, the center of gravity of the print head module is located above the resulting lower support place, shuttle. The rocking mounting of the printhead module allows, for example, through the lifting and lowering device on the printer side, the necessary degrees of freedom that are necessary to position the printhead module between its free hanging position and a fixed printing position in the device. The swinging position can be implemented essentially by a suitable mechanical hanger. In this case, knife or cup bearings are as conceivable as a hanging connection via a flexible connecting part, such as a rope element or the like. In the last case, the hanging part is the rope element itself. In addition, the suspension part is shaped, for example, spherically, conically or in the form of a connector.

[0014] Preferably, the suspension of the printhead module is used as a support to fix the printing position. In this preferred embodiment, the hanger parts are shaped so that the suspended printhead module can be hung parallel to the transverse direction and is swayed by an angular coordinate. By positioning the printhead module parallel to the transverse direction, important pre-positioning is obtained. The perpendicular positioning of the printhead module extending in the transverse direction to the direction of travel of the printing medium is important for the achieved print quality. If there is a deviation from the right angle in the direction of travel, then this leads to the displacement of individual printed points relative to the desired position of the image point in the transverse direction. To this end, the hanger for the printhead module is shaped, for example, as a sliding bearing that allows sliding in the transverse direction, but does not allow any degree of freedom in the sliding direction. Such a bearing with a suitable suspension part can be shaped in particular as a transverse sliding guide.

[0015] To this end, preferably, the hanging part is shaped as a conical part, which can be hung in a transverse, prismatic or wedge-like depression or the like. In order to enable the rolling motion, the taper opening angle is especially smaller than the opening angle of a prismatic or wedge depression. If the acetabulum is open, especially on one side in the transverse direction, then the printhead module can easily be hung and removed, [0016] Preferably, at least two hanger parts arranged in the transverse direction are provided. In this way, the desired parallel alignment of the printhead module relative to the lateral direction is forcedly obtained with the suspension.

In a further preferred embodiment, coarse positioning gripping means are arranged on the housing with respect to the intended printing position. In cooperation with a one-pass inkjet printer, these gripping means are used for coarse positioning of the incoming, especially the falling printhead module. Particularly during insertion, the swaying printhead module sets its center of gravity due to its gravity. The gripping means are then shaped so that they are able to detect possible positioning elements in the device during the movement of the printhead module, especially when lowering, and pre-position the latter relative to the final printing position.

In a preferred embodiment, the gripping means are formed by a gripping wedge or a wedge shaft. If, for example, one wedge shaft is provided, mounted on the housing of the printhead module, then it can cooperate with the gripping wedge fixed in the device. When gradually moving, especially lowering the printhead module to the printing position, the wedge shaft adopts initially a fixed, sharp wedge end, and then the entire wedge, thanks to which module 3

58 2 582 526 Β1 of the print head is further limited in its still possible degrees of freedom, for example, lateral displacement or angular pendulum movement. Accordingly, the printhead module is guided by the gripping means, in a forced manner, intentionally into a subsequent fixed printing position. Conversely, the gripping wedge mounted on the printhead module housing can work in the same way with a wedge shaft permanently mounted in the device.

[0019] In a particularly preferred configuration, the gripping wedge or the wedge shaft are shaped for substantial vertical sliding guidance with a corresponding mating part. By such sliding guidance, with simultaneous initial positioning in the transverse direction, further movement of the printhead module in the vertical direction is possible. Preferably, a gripping angle arranged parallel to the direction of travel or a groove depression arranged parallel to the direction of travel is preferably provided as the gripping means. Through the gripping wedge, set in the direction of travel, the angular coordinate during the movement of the printhead module to the printing position is ascertained. By grooving lowering, set in the direction of travel, the printhead module is fixed in the transverse direction.

[0020] Preferably, at least two supporting parts arranged in the transverse direction are arranged on the housing, which are shaped in each case for self-adjusting positioning in the open support. Especially when gripping means are provided, the self-adjusting supports in the vertical direction need not be constructed in a complicated manner. It is only necessary for the two supporting elements carrying the support to automatically position each other during the gradual introduction of the printhead module, so that the final position is finally determined. Corresponding supporting parts are intended for interaction with, for example, a knife or claw ball bearing. In this regard, the support parts can be made in particular conically, conically, in an angular, pointed or spherical manner.

[0021] In a further preferred embodiment, the support parts are mounted on the housing in a vertically adjustable manner. In this way, executive dimensional tolerances can be aligned or the printheads are vertically adjustable for the printing position.

[0022] In a preferred embodiment, one of the support parts is configured for positioning in a fixed support and the other of the support parts for positioning in a bearing mounted slidably in the transverse direction. For example, the extent of the printhead module in the transverse direction can be captured through the slide-mounted bearing. In a deliberate design, the fixed support is in each case shaped as a support for a spherical journal, and the bearing is slidably mounted by means of a prismatic lateral slide. In addition, the support parts are preferably shaped as spherical pins each time. Then, preferably, the fixed support for pivot bearing is equipped with a conical bearing, in which the spherical end of the journal is received and positioned during the vertical insertion of the printhead module. The prismatic sliding guide is shaped especially also as the support of the spherical journal, however, the cup is shaped with a prismatic cross-section along the transverse direction. The prismatic sliding guide then sets the parallel position of the printhead module to the lateral direction. In the transverse direction itself, a linear adjustment is still possible as a degree of freedom.

[0023] Further, preferably, a stop portion for colliding with the stop surface is arranged on the printhead module. Such a stop part sets the inclination of the printhead module in particular by an angular coordinate, provided the hanger does not completely limit the degree of freedom in the direction of travel. This is the place

ΕΡ 2 582 526 zwłaszcza1 especially when the printhead module is shaped for upright attachment in the final printing position, the hanging parts being removed from the hanger.

[0024] Particularly preferably, the stop portion includes a spherical plug extending in lateral direction. When the hanging printhead module is moved to the printing position, the spherical plug gradually comes into contact with a solid stop surface in the device that ultimately positions the kufty plug in the direction of travel. A spherical spigot, together with, for example, a barrel-shaped stop surface allows a specific collision regardless of the vertical height. In the final printing position, the respective printhead module is then accurately fixed, for example, by both open supports, namely the spherical support, as a fixed support and prismatic sliding guidance, as a sliding bearing, and by a stop portion adjacent to the stop surface. In this case, in particular, the angle of inclination or the angular coordinate is determined by the abutting stop part. Appropriate guidance is taken over by the stop part, in cooperation with the fixed vertical stop surface in the device.

[0025] Another important aspect of the invention is to adjust the position of the printheads relative to the at least one reference position. By determining the position of the printheads relative to at least one reference position, when the final printing position is reached, the printhead modules are constantly set identically, except for dimensional tolerances that cannot be avoided. In other words, each printhead module, with respect to at least one reference position, constantly has the same position setting of its respective printheads. This results in easy replacement of the printhead modules. The position of the printheads of the replaced and newly mounted printhead module are identical in terms of the device side.

[0026] Thanks to these measures, the laborious re-adjustment of the embedded printhead module is eliminated. The printheads, after the print head module has been easily seated, are already adjusted to dimensional tolerances. Only in the case of reconstruction of a single-pass inkjet printer, based on manufacturing tolerances or the like, must first be set printhead modules, from the device side, in each support position. Due to the identical initial positioning of the printheads of all printhead modules, however, this also shapes easily compared to the previous laborious on-site positioning.

[0027] In order to regulate the position of the printheads, they are mounted in the printhead module slidably in, for example, in the transverse direction and the direction of travel. In a suitable tool, the printhead module, before it is released, is brought to a mounting position comparable to a later printing position to adjust the position. Then, the individual printheads are adjusted, for example by means of microscope light in the micrometer range, to the position of the reference position.

[0028] Preferably, the adjusting heads are in each case adjustable in position relative to the supporting parts, for example spherical plugs. To this end, the printhead modules are fed to the subsequent printing position prior to delivery to the corresponding blank. This tool has identical supports as the later single-pass inkjet printer. Since the printhead module is accurately positioned by two supporting parts, displaced in the transverse direction and by suspension also in the tool, the printheads can in particular be arranged in parallel and in the transverse direction and in the direction of travel. The height of the printheads can then, for example, be adjusted by supporting parts, vertically adjustable, [0029] In order to keep the printhead module, especially the optionally included electronic control device and the printheads as such, in a dust-free state, further preferably a housing 5

ΕΡ 2 582 526 Β1 includes a number of air gaps, with air being provided into the interior space of the housing. In this way, overpressure can be created in the inner space of the printhead module, where excess air escapes again through the air gaps. In this way, dust and dirt are kept away from the printhead module.

[0030] Document WO 2 005 108 094 shows a suspendable print head, [0031] Embodiments of the invention will be explained in more detail on the basis of the drawing. It shows:

1 shows a printhead module with a hanger for vertical sliding guiding.

[0032] Fig. 1 shows the printhead module 1, with the housing 3 on which two hanger parts 4 are located on the upper side. The hanger parts 4 in a single-pass inkjet printer allow hanging printhead module 1 to be hung later for a fixed print position in the device. [0033] For orientation, in Figure 1 the drawing direction 7 of the respective print medium is shown, the transverse direction 8 perpendicular to it, and the vertical direction 9. In a fixed printing position in the device, the printing medium moves in the direction of travel 7 under the printhead module 1.

[0034] In the transverse direction 8, a number of printheads 10 are mounted on the bottom side of the printhead module 1. The printheads 10 are mounted in such a way that only one compact printable area is created across the width. In addition, the printheads 10 are offset relative to each other in the direction of travel and are arranged in a transverse direction, overlapping each other. In this regard, reference is made to the fact that each printhead 10 includes a number of nozzles that are held in each frame.

[0035] The printhead module 1 further includes a number of connectors 12 that serve to supply current, control signals and ink. Inside the housing 3 there is an electronic control device for controlling the printheads 10 and an ink tank.

[0036] In addition, the housing 3 comprises a number of air gaps 15 and an air inlet 16. Compressed air is introduced from the outside through the air inlet 16, which again leaks out in particular through the air gaps 15. In this way dust or other impurities are kept from away printhead module 1.

In order to vertically suspend the printhead module 1, two hinged parts 8 arranged in a transverse direction 4. The hanger parts 4 are in each case shaped as hanging parts 19, which enable swinging suspension in a suitable bearing bearing. Hanging parts 19 they are shaped in each case as conical parts 20. The conical parts 20 have a smaller angle of inclination than the bearing shell of the respective bearing. Due to the laterally displaceable arrangement of the two conical parts 20, when the printhead module 1 is suspended, it is already positioned parallel to the transverse direction 8. Then both conical parts 20 allow the printhead module 1 to swing in the appropriate bearing with an angular coordinate. In other words, the printhead module 1 will be positioned by virtue of gravity, when suspended, in a substantially vertical direction. [0038] On the other hand, the provided suspension parts 4 also allow the inclination angle or the angular coordinate to be set to set the print beam with the print heads 10 parallel to the print medium path. The print media path can be shaped, for example, as a bent arc, which allows a more tenuous guiding of the print medium.

[0039] Further, the housing 3 is mounted on both sides, and thus in the transverse direction 8, the support parts 23, 24, which are staggered in an adjustable manner. On the support parts 23, 24, each vertically adjustable ball spigot 27, 28 is additionally mounted. , on both parts 6

ΕΡ 2 582 526 Β1 supports 23, 24, each gripping means 30 is mounted, only the right gripping means 30 is shown in Figure 1. The gripping means 30 comprises a wedge shaft 32 open in the vertical direction 9, which has on its other side groove depression 33 in the transverse direction 7.

[0040] When lowering the printhead module 1, suspended through the suspension parts 4 of, for example, the lifting and lowering device of a single-pass inkjet printer, the gripping means 30 gradually acquire a position with the corresponding mating part on the printer. This cooperating part is shaped in each case as a gripping kiin directed in the direction of travel 7. This gripping wedge is first embraced by the groove lowering 33 and slides deep into the wedge shaft 32. The gripping wedge of the single-pass inkjet printer and the wedge shaft 32 each form vertical sliding guide for both support parts 23, 24.

[0041] On further lowering, the printhead module 1 is positioned in the angular coordinate and in the transverse direction, since the gripping means 30 gradually slide completely over the gripping wedge fixed in the device. The gripping means 30 therefore causes the coarse positioning of the printhead module 1 when it is lowered, relative to the final printing position obtained.

[0042] After coarse positioning, both ends of the ball spherical balls 27, 28 align in the ball bearing pivot open each time. In addition, one of the ball bearing bearings includes a fixed cup bush with a tapered depression. The second of the two bearings includes a prismatic lowering in the transverse direction 8. The ball 27, for example, forms a three-dimensional fixed pivot point with a conical depression. The ball of the opposite ball spigot 28 fixes the position of the support part 24 in the vertical direction 9 and in the direction of travel 7. In transverse direction 8, the offset is possible due to the prismatic lowering, thanks to which the longitudinal extensions of the printhead module 1 are captured.

[0043] In the finally obtained printing position, the printhead module 1 stands in the respective supports of the support parts 23 and 24. Both conical parts 20 are removed from the respective cup bearings. In this removed position, there is again a degree of freedom for the upper side of the printhead module 1 in the direction of travel 7. To determine the angle of inclination or angular coordinate, a stop part 35 is provided on the upper side of the housing 3, which includes a spherical pin 37. This spherical pin 37, when lowering the printhead module 1, falls onto the pre-tensioned barrel stop surface of a single-pass inkjet printer. In this way it is ensured that when removing the conical parts 20 in the obtained printing position, the angle of inclination of the printhead module 1 is precisely determined.

[0044] In the printing position obtained in the device constant, the printhead module 1 is limited in all degrees of freedom by the provided three supports, and is therefore accurately positioned.

[0045] The stop portion 35 is not necessarily necessary. For example, the hanger can be made as a knife support that accurately determines the pivot point. In particular, the hanger in the printing position also does not have to be removed.

[0046] The respective print heads 10 are adjustable in position relative to the spherical balls 27, 28 in the direction of travel 7 and in the transverse direction 8. For the subsequent printing position constant in the device, the print heads 10 are adjustable in position also in the vertical direction 9 by vertically moving spherical pins 27, 28.

[0047] The adjustment of the position in the transverse direction 8 and in the direction of travel 7 of the printheads 10 takes place through the longitudinally sliding support in the housing 3. The position adjustment itself is carried out by means of the light of the microscope. For this, the printhead module 1 with its 7 shown

ΕΡ 2 582 526 Β1 support places is embedded in a suitable tool, which in the later printing position creates identical support.

[0048] By adjusting the position of the printheads 10 it is possible to easily replace the printhead modules 1, without the laborious manual final adjustment in place.

List of markers [0049]

<td> 10</td><td> 1</td><td>printhead module</td>

<td></td><td> 3</td><td>housing</td>

<td></td><td> 4</td><td>hanger part</td>

<td></td><td> 7</td><td>direction of travel</td>

<td></td><td> 8</td><td>transverse direction</td>

<td> 15</td><td> 9</td><td>vertical direction</td>

<td></td><td> 10</td><td>printheads</td>

<td></td><td> 12</td><td>connections</td>

<td></td><td> 15</td><td>air gaps</td>

<td></td><td> 16</td><td>an air inlet</td>

<td> 20</td><td> 19</td><td>hanging part</td>

<td></td><td> 20</td><td>conical part</td>

<td></td><td> 23</td><td>supporting part</td>

<td></td><td> 24</td><td>supporting part</td>

<td></td><td> 27</td><td>spherical pin</td>

<td> 25</td><td> 28</td><td>spherical pin</td>

<td></td><td> 30</td><td>gripping means</td>

<td></td><td> 32</td><td>wedge shaft</td>

<td></td><td> 33</td><td>groove lowering</td>

<td></td><td> 35</td><td>bumper part</td>

<td> 30</td><td> 37</td><td>kufisty spigot</td>

ΕΡ 2 582 526 Β1