SINGLE-PASS INKJET PRINTER

Abstract

A single-pass inkjet printer contains a track for guiding a printing medium in the Y direction, a plurality of printing head modules which are arranged one behind the other in the Y direction and a respective plurality of printing heads which extends in the X direction transversely over the track, and a printing region in which the printing head modules can be mounted in a respective printing position in an upright manner in the Z direction and in a reversibly insertable and removable manner along the Z direction. The single-pass inkjet printer further contains a storage region in which a number of printing head modules are mounted in a storage position in an upright manner substantially in the Z direction and in a reversibly insertable and removable manner along the Z direction. The printing heads of printing head modules set in the storage position are received in a protective cover.

Claims

1. A single-pass inkjet printer, comprising: a running track for guiding a printing medium in a Y-direction; a plurality of print head modules disposed behind one another in the Y-direction and extending in each case with a plurality of print heads in an X-direction transversely over said running track; a printing region in which said print head modules are mounted such that they stand upright in a respective printing position substantially in a Z-direction and can be inserted and removed reversibly along the Z-direction; a protective cover; and a storage region being offset in the X-direction or in the Y-direction with respect to said printing region and in said storage region a number of said print head modules being mounted such that said print head modules stand upright in a respective storage position substantially in the Z-direction and are inserted and removed reversibly along the Z-direction, said print heads of said print head modules which are set in the respective storage position being received in said protective cover.

2. The single-pass inkjet printer according to claim 1, further comprising a cleaning device disposed in said storage region, said cleaning device having a number of doctor blade carriers which are assigned to in each case one storage position, can be displaced in the X-direction, and in each case carry a number of doctor blades.

3. The single-pass inkjet printer according to claim 2, wherein precisely one of said doctor blades is assigned to each of said doctor blade carriers for each of said print heads of a set of said print head modules.

4. The single-pass inkjet printer according to claim 2, wherein said cleaning device has a drive device for displacing a or each of said doctor blade carriers.

5. The single-pass inkjet printer according to claim 4, wherein at each said respective storage position, said cleaning device has a drive device for displacing in each case one of said doctor blade carriers.

6. The single-pass inkjet printer according to claim 2, wherein each of said doctor blades is guided on a respective one of said doctor blade carriers such that said doctor blade is adjusted in the Z-direction between a cleaning position and a distance position; and further comprising doctor blade setting devices, each of said doctor blade setting devices for adjusting in each case one of said doctor blades between the cleaning position and the distance position.

7. The single-pass inkjet printer according to claim 6, further comprising: first guide tracks extending in the X-direction; second guide tracks extending in the X-direction; and connecting sections each connecting one of said first guide tracks to one of said second guide tracks, wherein each of said doctor blades is positively guided in the cleaning position along said one first guide track and is positively guided in the distance position along said one second guide track, and said doctor blade setting devices being configured for switchable determining which of said first and second guide tracks is to be taken.

8. The single-pass inkjet printer according to claim 7, further comprising engagement elements disposed in said first guide tracks or in said second guide tracks, each of said doctor blades is guided by means of said one of said engagement elements; and wherein said doctor blade setting devices each have a magnetic element which acts on a respective one of said engagement elements in a respective one of said connecting sections.

9. The single-pass inkjet printer according to claim 1, further comprising a maintenance region being offset in the X-direction with respect to said storage region, in said maintenance region said print head modules are mounted such that said print head modules stand upright in a respective maintenance position substantially in the Z-direction and can be inserted and removed reversibly along the Z-direction.

10. The single-pass inkjet printer according to claim 9, wherein said storage region provides, for each of said print head modules, in each case one storage apparatus which can be displaced in the X-direction and in which a set print head module assumes a storage position, said protective cover being a part of said storage apparatus, and in that said storage region and said maintenance region can be coupled in such a way that said storage apparatus can be displaced with said set print head module in the Z-direction out of said storage region onto said maintenance region.

11. The single-pass inkjet printer according to claim 10, wherein said storage region and said maintenance region in each case have guide elements for guiding said storage apparatus, it being possible for said guide elements of said storage region and said guide elements of said maintenance region to be coupled to one another in order to form a displacement track which is continuous in the X-direction.

12. The single-pass inkjet printer according to claim 10, wherein said maintenance region is configured as a mobile maintenance carriage.

13. The single-pass inkjet printer according to claim 10, wherein said maintenance region has a stop buffer and a fixing element for each said storage apparatus which is moved in.

14. The single-pass inkjet printer according to claim 2, wherein said cleaning device has a drive device for displacing a or each of said doctor blade carriers along the X-direction.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0035] FIG. 1 is a diagrammatic, perspective view of a detail of a printing region of a single-pass inkjet printer with a print head module which is set into a printing position, in which it is fixed on the unit, and according to the invention;

[0036] FIG. 2 is an illustration showing the single-pass inkjet printer which has a printing region, a storage region and a maintenance region;

[0037] FIG. 3 is a partial, perspective view of the storage region and the maintenance region of the single-pass inkjet printer, a storage apparatus which can be displaced between the storage region and the maintenance region being included;

[0038] FIG. 4 is partial, perspective view of the storage region and the maintenance region of the single-pass inkjet printer in accordance with FIG. 3, the displaceable storage apparatus being displaced onto the maintenance region;

[0039] FIG. 5 is a plan view of the storage region and the maintenance region of the single-pass inkjet printer, the print head module being set into a displaceable storage apparatus in the storage region;

[0040] FIG. 6 is a plan view of the storage region and the maintenance region of the single-pass inkjet printer in accordance with FIG. 5, the storage apparatus with a set print head module being displaced onto the maintenance region;

[0041] FIG. 7 is an illustration showing a cleaning device with a displaceable doctor blade carrier in an enlarged detail view of the storage region of the single-pass inkjet printer;

[0042] FIG. 8 is another enlarged perspective view of the storage region of the single-pass inkjet printer in accordance with FIG. 7, the storage apparatus with a doctor blade carrier having been pushed out; and

[0043] FIG. 9 is a perspective partial view of a displaceable doctor blade carrier of a cleaning device in accordance with FIGS. 7 and 8.

DETAILED DESCRIPTION OF THE INVENTION

[0044] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a printing region 2 in a three-dimensional illustration for a single-pass inkjet printer 1. For orientation, an orthogonal coordinate system with the three spatial directions X, Y and Z is illustrated.

[0045] A printing medium 4 is moved continuously in the Y-direction (running direction) along a running track 3 during a printing operation. A print head module 6 extends in the X-direction (transverse direction) over the entire printing medium 4, which print head module 6 is mounted fixedly on the unit on a frame construction 8 of the single-pass inkjet printer 1 in an oriented printing position such that it stands upright substantially in the Z-direction (vertical direction).

[0046] The print head module 6 has a load-bearing frame 10 which extends with a cross-member 11 in the X-direction transversely over the printing medium 4. A transverse bracket 12 is mounted in a suspended manner via two side cheeks 13 on the cross-member 11 of the load-bearing frame 10. Here, the mounting permits swinging of the transverse bracket 12 about a swing axis which is oriented in the X-direction. The swing axis runs, in particular, through the cross-member 11 or just below the cross-member 11, with the result that the centroid of the transverse bracket 12 is situated below the cross-member 11 in the Z-direction. If the print head module 6 is lifted out vertically in the Z-direction, the transverse bracket 12 is aligned in an oriented manner by way of gravity below the cross-member 11.

[0047] A multiplicity of print heads 14 are arranged on the transverse bracket 12 along the X-direction over the printing medium 4. Control boards 15 and supply lines for operating materials or for supplying electric energy are mounted on the load-bearing frame 10. As a result, the weight of components of the print head module 6 which acts on the print heads 14 is reduced. A weight-induced deformation of the transverse bracket 12 and therefore an undesired displacement of the print heads 14 with respect to the adjusted printing position are prevented. This allows the dimension of the print head module 6 along the X-direction to be increased in comparison with the prior art. The transverse bracket 12 of the single-pass inkjet printer 1 which is shown in FIG. 1 has, for example, a length of over 2.5 m in the X-direction.

[0048] A coupling module 16 can be coupled and decoupled on the cross-member 11 of the load-bearing frame 10 via a multiple coupling which is not shown in detail. Here, the multiple coupling is operated via an electric motor 17 which is placed onto the coupling module 16. For example, the motor 17 actuates screw connections, via which the coupling module 16 and the cross-member 11 are coupled to one another with simultaneous connection of supply lines, control lines and/or electric lines. During coupling, the cross-member 11 and the coupling module 16 approach one another. During the decoupling, the cross-member 11 and the coupling module 16 move away from one another. The coupling module 16 makes simple connection of the print head module 6 to the supply and control lines of the single-pass inkjet printer 1 possible.

[0049] In order to lift the print head module 6 out and in the Z-direction (vertical direction), furthermore, mounting aids 19 which are configured, for example, as cable fastening devices are arranged on the coupling module 16. Cable ends of a lifting/lowering device (not shown) are coupled on the mounting aids 19. The print head module 6 is raised or lowered for installation or dismantling by way of the cable length being changed by means of the lifting/lowering device. Furthermore, two ink reservoirs 20 are mounted on the coupling module 16, the print heads 14 being supplied with ink during the printing operation via the supply lines which are likewise coupled by the multiple coupling.

[0050] The cross-member 11 of the print head module 6 has two carrying arms 22 which extend laterally in the X-direction as far as over the frame construction 8. The carrying arms 22 and therefore the load-bearing frame 10 of a load-bearing construction 25 which is configured on both sides, which load-bearing frame 10 carries the substantial weight of the print head module 6, are placed via a supporting device 24 which cannot be seen in greater detail here, which load-bearing construction 25 for its part is mounted on the frame construction 8 of the single-pass inkjet printer 1. For reasons of clarity, merely the right-hand load-bearing construction 25 in FIG. 1 is illustrated here.

[0051] The print head module 6 which is deposited on the load-bearing constructions 25 via the supporting device 24 is already aligned in accordance with the provided printing position in a manner which is oriented by way of gravity. To this end, the carrying arms 22 are guided vertically upward with regard to the cross-member 11. Accordingly, the print head module 6 can be lifted in and out of the single-pass inkjet printer 1 easily in the vertical direction. The supporting devices 24 are deposited on the carrying arms 22, in each case on a rest 27 of the load-bearing construction 25. The rest 27 is shown on an enlarged scale in a detailed view. Each rest 27 contains a planar supporting face 28 which is mounted in a rotatably movable manner in a ball joint. The supporting face 28 of the rest 27 is oriented in the ball joint by way of the weight of the deposited load-bearing frame 10, with the result that there is always a flat contact between the supporting device 24 and the rest 27, even in the case of an inclined angle of the print head module 6, which inclined angle is possibly desired in the printing position.

[0052] Bearing pieces 30 are mounted in each case at the lower ends of the side cheeks 13 of the transverse bracket 12 which is suspended in a swinging manner. When the print head module 6 which has already been pre-oriented by way of gravity is lifted in, the bearing pieces 30 are precision adjusted by respective catching device 32 with respect to corresponding bearing seats of open bearings 34. Here, the catching devices 32 are configured in each case as a combination of a catching wedge and a wedge shaft which receives the catching wedge. The bearing pieces 30 are configured, for example, as ball pivots. To this end, the bearing seats of the open bearings 34 which are arranged on both sides of the running track 3 on the frame construction are preferably configured as conical, spherical or prismatic seats. Here, one of the open bearings 34 is further preferably configured as a fixed bearing with regard to the X-direction, and the other one of the open bearings 34 is configured as a floating bearing. As a consequence, for example, a bearing combination with a spherical or conical seat on one side and with a prismatic seat on the other side of the print head module 6 is formed. A prismatic seat which extends in the X-direction permits displaceability in the X-direction, while the Y-coordinate and the Z-coordinate are fixed. A longitudinal offset of the print head module 6 in the X-direction on account of thermal cycling is absorbed in a defined manner by way of a fixed/floating bearing combination of this type in the open bearings 34. In particular, a creeping offset of the print head module in the X-direction is prevented, since both a longitudinal expansion and a longitudinal contraction are absorbed in a defined manner by way of always the same one of the bearings 34, namely by way of the floating bearing.

[0053] In order to fix the printing position, in which it is fixed on the unit, of the print head module 6 which is received in the single-pass inkjet printer 1, a stop piece 36 is mounted on a side cheek 13 of the transverse bracket 12. The stop piece 36 is defined with respect to a stop face 38 of the frame construction 8. When the print head module 6 is lifted in, the inclination or polar angle of the print head module 6 is defined in the printing position, in which it is fixed on the unit, via the stop piece 36 and the stop face 38.

[0054] FIG. 2 diagrammatically shows a plan view from above of the entire construction of a single-pass inkjet printer 1 in accordance with FIG. 1. The printing region 2 which is shown in FIG. 1 can be seen in the plan view, three print head modules 6 being lifted in each case at their corresponding printing position 47 by way of example behind one another in the Y-direction (running direction) of the printing medium 4. Here, each of the print head modules 6 which are lifted into the printing region 2 is provided for printing the printing medium 4 with a specific color or ink.

[0055] In a manner which is spaced apart in the Y-direction from the printing region 2, furthermore, the single-pass inkjet printer 1 has a storage region 40, in which print head modules 6 can be introduced, for cleaning purposes or for protecting the print heads, out of the printing region 2 by means of a lifting/lowering device (not shown here) after being lifted out in the vertical direction, by way of movement in the Y-direction and subsequent lowering. In the present case, three print head modules 6 are lifted in their respective storage position 49 into the storage region 40.

[0056] For external maintenance or for exchanging individual print head modules 6, furthermore, the single-pass inkjet printer 1 has a maintenance region 45 which is arranged laterally of the storage region 40 in the X-direction. The maintenance region 45 is configured, for example, as a mobile maintenance carriage 51 which is configured, in particular, such that it can be moved in the Y-direction, and can be coupled to the storage region 40. Individual print head modules 6 are changed between the storage region 40 and the maintenance region 45 by way of being pushed in or out laterally. The print head modules 6 which are situated in the respective maintenance position 50 in the maintenance region 45 are moved to another location by way of movement of the maintenance carriage 51, for the purpose of an inspection or an exchange.

[0057] FIG. 3 shows a three-dimensional view of the storage region 40 and the maintenance region 45 of the single-pass inkjet printer 1 in one exemplary refinement. The maintenance region 45 is configured as a movable maintenance carriage 51. In the situation which is shown, a print head module 6 is lifted neither into the storage region 40 nor into the maintenance region 45.

[0058] A frame construction 52 can be seen on the storage region 40. A protective cover 53 for covering the print heads of received print head modules 6 is configured at each storage position 49 of the storage region 40. The protective cover 53 is in each case a fixed constituent part of a storage apparatus 54 which can be displaced in the X-direction and for its part has in each case the load-bearing constructions 25 which are configured in accordance with the printing region 2 (see FIG. 1), including the rests 27 and the catching devices 32. The print head modules 6 which are lifted in the vertical direction out of the printing region 2 or out of their printing position 47 there can correspondingly be lifted into the respective storage apparatus 54 with corresponding orientation. Here, the supporting devices 24 of the print head modules 6 accordingly lie on the corresponding rests 27 of the respective storage apparatuses 54. The bearing pieces 30 of print head modules 6 which have been lifted in are positioned in the corresponding open bearings 34. Merely stop faces 38 for inclining print head modules 6 which have been lifted in via their corresponding stop pieces 36 are not provided in the storage apparatuses 54. Print head modules 6 which have been lifted in stand upright in a manner which is oriented in the vertical direction in the respective storage position 49.

[0059] Each of the four storage apparatuses 54 in the exemplary embodiment which is shown is guided on the frame construction 52 by means of guide elements 57 such that it can be displaced in the X-direction. The guide elements 57 of the storage region 40 can be coupled with corresponding guide elements 57 of the maintenance carriage 51 to form a continuous displacement track 60 along the X-direction if the maintenance carriage 51 is positioned correspondingly in the Y-direction with respect to the storage region 40. In addition to the guide elements 57, the maintenance carriage 51 has retaining brackets 62 which serve to store cover plates of a received print head module 6. The non-illustrated cover plates of this type are mounted on the print head modules 6 in accordance with FIG. 1 on the sides which are open there in order to cover the interior space and for mechanical stabilization. This can also be gathered, in particular, from FIGS. 5 and 6 (see designation 66).

[0060] Via the jointly formed continuous displacement track 60, a storage apparatus 54 with a print head module 6 which is lifted in can be displaced out of the storage region 40 into the maintenance region 45 and vice versa. Each print head module 6 which is lifted in can be pushed out or in separately. In order to limit the displacement movement of a storage apparatus 54, a stop buffer 63 is mounted on the end side of the maintenance carriage 51.

[0061] Furthermore, a cleaning device 64 is configured in the storage region 40 of the single-pass inkjet printer 1 which is shown. Here, the cleaning device 64 has a plurality of individual doctor blades 65 which are directed from below against the print heads of a set of print head modules 6. The doctor blades 65 are likewise part of the displaceable storage apparatus 54 and can be displaced in the X-direction in a to and fro movement via a doctor blade drive device (designation 87 in FIG. 8).

[0062] FIG. 4 shows the storage region 40 and the maintenance region 45 of the single-pass inkjet printer 1 in accordance with FIG. 3 in a three-dimensional view. In comparison with FIG. 3, however, in FIG. 4 one of the storage apparatuses 54 is then pushed out in the X-direction along the displacement track 60 which is formed by means of the guide elements 57 of the storage region 40 and of the maintenance region 45 onto the maintenance carriage 51. Here, the storage apparatus 54 which is pushed out comes into contact with the stop buffer 63 of the maintenance carriage 51. It can be seen, in particular, that the storage apparatus 54 including the load-bearing constructions 25, the catching device 32, the open bearings 34 and the doctor blade 65 is displaced onto the maintenance carriage 51. The doctor blades 65 are mounted, in particular, in the interior of the protective cover 53.

[0063] FIGS. 5 and 6 show the storage region 40 and the maintenance region 45 of the single-pass inkjet printer 1 in accordance with FIGS. 3 and 4 from another perspective, namely from a viewing direction in the Y-direction (running direction). In contrast to FIGS. 3 and 4, however, a print head module 6 in accordance with FIG. 1 is then lifted into a respective storage apparatus 54. In particular, the lateral carrying arms 22, the coupling module 16, the motor 17 and the stop piece 36 of the print head module 6 can be seen. The rests 27 of the print head module 6 lie on the supporting face 28 of the load-bearing constructions 25 which are arranged on both sides. The bearing pieces 30 are received in the corresponding open bearing 34 of the storage apparatus 54. The print head module 6 is shown with inserted covering plates 66 in FIGS. 5 and 6.

[0064] In FIG. 5, the print head module 6 is positioned with the storage apparatus 54 in the storage region 40. In FIG. 6, the storage apparatus 54 is pushed out with the received print head module 6 onto the maintenance carriage 51. The contact with respect to the stop buffer 63 can be seen.

[0065] FIG. 7 shows, partially in cross section and partially in plan view, a detail of the cleaning device 64. In the detail, in particular, the mounting of the doctor blades 65 for cleaning the print heads of set print head modules 6 can be seen.

[0066] Each doctor blade 65 of the cleaning device 64 is assigned a doctor blade setting device 67. Each doctor blade setting device 67 has a setting element 68 which is configured, for example, as a magnetic element 81. The doctor blades 65 are mounted jointly on a doctor blade carrier 70 which can be displaced in the X-direction in a to and fro movement. Corresponding guide rollers 71 to this end can be seen. With respect to the doctor blade carrier 70, the doctor blades 65 are in turn mounted in each case by a carrying element 73 such that they can be displaced in the Z-direction. To this end, the carrying element 73 of each doctor blade 65 is guided by means of a respective engagement element 74 in each case either in a first guide track 77 which extends in the X-direction or in a second guide track 78 which extends in the X-direction. Both guide tracks 77, 78 are coupled to one another via a connecting section 80 which extends substantially in the Z-direction. The doctor blade carrier 70 moves in the X-direction relative to the components of the cleaning device 64 during a cleaning operation.

[0067] In the present case, the doctor blade 65 which is shown is situated in a distance position A, the engagement element 74 being guided in the second guide track 78. If the doctor blade carrier 70 is moved in the X-direction, the doctor blade 65 remains at a distance position with regard to the Z-direction with respect to the print head 14 of a set print head module 6. The doctor blade 65 is spaced apart further from the respectively assigned print head 14 than in the cleaning position.

[0068] The carrying element 73 is prestressed in the Z-direction with respect to the doctor blade carrier 70. If the carrying element 73 is aligned with the setting element 68 during the cleaning movement, without said setting element 68 being activated, the engagement element 74 is pulled upward along the connecting section 80 on account of the mechanical prestress. During a return movement of the doctor blade carrier 70, the doctor blade 65 is then situated in the cleaning position R, the engagement element 74 being guided in the first guide track 77. In other words, the cleaning position R is the mechanically predefined position of the doctor blade 65. If a doctor blade 65 is to be moved into the distance position A, the setting element 68 or, by way of example, the magnetic element 81 is activated during the cleaning movement if the carrying element 73 is aligned. In this way, the engagement element 74 is moved via the connecting section 80 into the second guide track 78 counter to the mechanical prestress or remains there, with the result that the distance position A is given during the cleaning movement of the doctor blade carrier 70 (a to and fro movement in the X-direction). The activated magnetic element 81 acts on a correspondingly ferrimagnetic or ferromagnetic material element on the carrying element 73, counter to the mechanical prestress.

[0069] The cleaning device 64 which is shown makes it possible to switch each doctor blade 65 separately between a cleaning position R, in which the doctor blade 65 is close to the print head 14 of a set print head module 6, preferably touches the print head 14, and a distance position A, in which the doctor blade 65 is spaced apart further from the print head 14. If each print head 14 of a set print head module 6 is assigned a doctor blade 65, it becomes possible to actuate each print head 14 separately for cleaning.

[0070] In FIG. 8, details of the storage region 40 and, in particular, of the displaceable storage apparatuses 54 can be seen in a plan view. The protective cover 53 of a storage apparatus 54 which is pushed in can be seen clearly. The front storage apparatus 54 (at the bottom in FIG. 8) is pushed out.

[0071] Each storage apparatus 54 has a doctor blade carrier 70 which can be displaced in the X-direction and carries a plurality of doctor blades 65 which are mounted thereon in accordance with FIG. 7. In each case one doctor blade drive device 87 is assigned for displacing the doctor blade carrier 70 in a to and fro movement along the X-direction. To this end, for example, an electric motor is provided which acts directly on the doctor blade carrier 70 via a spindle drive. Furthermore, the left-hand open bearing 34 can be seen clearly in FIG. 8 on the storage apparatus 54 which is pushed in, which open bearing 34 has a conical seat for receiving a bearing piece 30 of a set print head module 6, which bearing piece 30 is configured as a ball pivot. Furthermore, a part of the load-bearing construction 25 and the catching device 32 (in the present case, the catching wedge) can be seen.

[0072] If the storage apparatus 54 is displaced in the X-direction along the guide elements 57 (a corresponding guide roller 85 is shown in FIGS. 7 and 8), the corresponding setting elements 68 or magnetic elements 81 of the cleaning device 64 remain in the storage region 40. A set print head module 6 remains securely and stably positioned on the storage apparatus 54, the print heads 14 continuing to remain in a securely protected manner in the protective cover 53. The doctor blade setting device 67 is decoupled. If the storage apparatus 54 is moved in, it acts through the bottom of the protective cover 53.

[0073] FIG. 9 shows a detailed view of the doctor blade carrier 70. The carrying element 73 and the engagement element 74 which is mounted on it can then be seen clearly, which engagement element 74 is positively guided in the guide tracks 77, 78 in accordance with FIG. 7. The carrying element 73 is prestressed upward with respect to the doctor blade carrier 70 via a spring element 88. Guide rollers 71, the rotational axes of which extend in the Z-direction and in the Y-direction, can likewise be seen clearly.