JP2012176544A - Ink jet head, ink jet head cleaning device and ink jet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cleaning quality in a dipping type head maintenance system.SOLUTION: When a head 100 dipped in a cleaning liquid is drawn up, a liquid membrane of the cleaning liquid is generated on the boundary between a nozzle surface 102 and the surface of the cleaning liquid by surface tension of the cleaning liquid (Fig.2(b)). When the head 100 is further moved up from this state, the resultant liquid membrane is guided and gathered to a liquid membrane guide member 104 which is the narrowest space between the nozzle surface 102 and the surface of the cleaning liquid which are at a distance (Fig.2(c)). The head 100 is further moved up from this state, the liquid membrane is separated at the liquid membrane guide member 104, and the residue of the cleaning liquid is generated in the liquid membrane guide member 104 (Fig.2(d)).

Description

  The present invention relates to an inkjet head, an inkjet head cleaning apparatus, and an inkjet recording apparatus, and more particularly to a head cleaning technique in which a nozzle surface is immersed in a cleaning liquid.

  In the ink jet recording apparatus, if the nozzle surface of the head (surface on which the nozzle is formed) is dirty, ejection failure occurs. For this reason, the nozzle surface is periodically cleaned.

  Conventionally known methods for cleaning the nozzle surface include a method for cleaning the nozzle surface by wiping with a blade, a method for cleaning the nozzle surface by wiping with a web, and the like.

  Further, Patent Document 1 discloses a cleaning liquid tank that fills a cleaning liquid for dissolving a fixed substance attached to a functional liquid discharge port formed on a nozzle surface of a functional liquid droplet discharge head that discharges a functional liquid, and a functional liquid droplet discharge head. And at least one of the cleaning liquid tanks is moved up and down to contact the cleaning liquid tank lifting means for immersing the nozzle surface of the functional liquid droplet discharge head in the cleaning liquid, and the functional liquid discharge port immersed in the cleaning liquid in the cleaning liquid tank, There has been disclosed a nozzle cleaning device including a wiping member for removing a fixed matter.

  According to the apparatus of Patent Document 1, the functional liquid discharge port is immersed in the cleaning liquid, so that the fixed matter in the vicinity of the functional liquid discharge port of the functional liquid droplet discharge head is dissolved by the cleaning liquid in the cleaning liquid tank. By making contact with the fixed matter inside the discharge port, it is possible to surely remove the fixed matter firmly stuck in the vicinity of the functional liquid discharge port. Thereby, the functional liquid discharge port is always kept in a good state, and dot omission, flight bending, discharge amount instability, and the like can be prevented.

JP 2006-272097 A

  As described above, the nozzle cleaning device of Patent Document 1 has a cleaning liquid tank that fills the cleaning liquid for dissolving the fixed matter adhering to the nozzle surface, and is wiped in a state where the nozzle surface is immersed in the cleaning liquid (dip method). Do. However, in this embodiment, when the nozzle surface is separated from the cleaning liquid surface after wiping, a cleaning liquid residue is generated at an unspecified position on the nozzle surface.

  Generation | occurrence | production of this residue is demonstrated using FIG.

  As shown in FIG. 11A, when cleaning the nozzle surface 202 of the head 200, first, the cleaning liquid surface filled in the cleaning liquid tank 210 and the nozzle surface 202 are maintained in a substantially parallel state. 200 is lowered with respect to the cleaning liquid tank 210, and the nozzle surface 202 is immersed in the cleaning liquid.

  In this state, the nozzle surface 202 is wiped off, and the fixed matter attached to the nozzle surface 202 is removed.

  When the cleaning of the nozzle surface 202 is completed, the head 200 is lifted from the cleaning liquid tank 210 in a state where the nozzle surface 202 and the cleaning liquid surface are kept substantially parallel. Here, it is assumed that the speed at which the head 200 moves up is about 0.5 mm / sec.

  Here, when the nozzle surface 202 is separated from the cleaning liquid and the gap between the nozzle surface 202 and the cleaning liquid surface is about 1 mm, the cleaning liquid surface tension causes the cleaning liquid to move as shown in FIG. A liquid film is generated.

  When the head 200 is raised and the gap is further widened, the generated liquid film gathers in the narrowest space between the separated nozzle surface 202 and the cleaning liquid surface due to the cohesive force of the cleaning liquid as shown in FIG. Go.

  When the head 200 is further raised, the liquid film is divided at the narrowest gap. As a result, as shown in FIG. 11D, a cleaning liquid residue is generated at the position where the liquid film is divided.

  If a residue of cleaning liquid is generated at an unspecified position on the nozzle surface in this way, wiping unevenness occurs during subsequent wiping, and there is a problem that the cleaning quality deteriorates and the deterioration of the liquid repellent film on the nozzle surface increases. is there.

  SUMMARY An advantage of some aspects of the invention is that it provides an inkjet head, an inkjet head cleaning apparatus, and an inkjet recording apparatus that improve cleaning quality in a dip-type head maintenance system.

  In order to achieve the above object, an inkjet head cleaning apparatus according to the present invention includes an inkjet head having a nozzle surface composed of a nozzle formation region and a region other than the nozzle formation region, and a cleaning liquid that holds a cleaning liquid that can be contacted by the nozzle surface. A lifting means for raising and lowering the inkjet head relative to the cleaning liquid holding means in a state in which the holding means and the nozzle surface and the cleaning liquid surface held by the cleaning holding means are substantially parallel to each other; Elevating means for moving up and down between a contact position where the nozzle surface is brought into contact with the cleaning liquid and a non-contact position where the nozzle surface is not brought into contact with the cleaning liquid, and the inkjet head is provided at least at one end of the nozzle surface with the nozzle surface And an inclined surface that protrudes toward the nozzle surface toward the end of the nozzle surface. A, characterized in that it induces a cleaning liquid film remaining on the nozzle surface when the nozzle surface is separated from the washing liquid surface to the inclined surface.

  According to the present invention, since the cleaning liquid film remaining on the nozzle surface is guided to the inclined surface continuous with the nozzle surface when the nozzle surface is separated from the cleaning liquid surface, the position where the residue is generated can be controlled. Accordingly, it is possible to improve the cleaning quality and improve the discharge stability in the dip type head maintenance system.

  According to the present invention, it is possible to improve cleaning quality and improve ejection stability in a dip type head maintenance system.

Diagram showing inkjet head Diagram showing inkjet head cleaning process Schematic diagram showing another embodiment for applying a cleaning liquid to the nozzle surface Front view showing the configuration of the main part of the inkjet recording apparatus A plan view showing a configuration of a main part of an ink jet recording apparatus Side view showing the configuration of the main part of the inkjet recording apparatus Perspective view of inkjet head Plan view of nozzle surface of inkjet head Schematic diagram showing the schematic configuration of the wiping unit The figure which shows the raising method of the inkjet head of other embodiment. Diagram for explaining generation of residue in conventional dip method

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Configuration of inkjet head]
FIG. 1 is a diagram schematically showing an inkjet head 100 (head 100) according to the present embodiment, and FIG. 1A is a side view of the head 100. FIG. As shown in FIG. 1A, the head 100 has a length in the longitudinal direction of L [mm], is one end in the longitudinal direction of the nozzle surface 102, and does not affect the ink ejection of the head 100 ( A liquid film guiding member 104 is provided in a region other than the nozzle forming region.

  As shown in FIG. 1B, the liquid film guiding member 104 has a triangular prism shape with a right triangle formed by the sides 104a, 104b, and 104c as a bottom surface and a side 104d as a height. The liquid film guiding member 104 is preferably formed of a material having lyophilicity with respect to the cleaning liquid.

  The lengths of the sides 104a and 104b are a [mm] and b [mm], respectively, and the angle formed by the sides 104a and 104b is a right angle. Further, the length of the side 104d substantially coincides with the length W of one side of the nozzle surface 102 in the short direction.

  Here, a surface formed by the sides 104a and 104d is referred to as surface A, a surface formed from the sides 104b and 104d is referred to as surface B, and a surface formed from the sides 104c and 104d is referred to as surface C.

  As shown in FIG. 1C, the surface A of the liquid film guiding member 104 is joined to the nozzle surface 102 so that the surface B and the side surface of the inkjet head 100 are continuous. Thus, the nozzle surface 102 is an inclined surface continuous with the nozzle surface 102 due to the surface C of the liquid film guiding member 104 and protrudes toward the nozzle surface 102 toward the end of the nozzle surface 102 (nozzle). An inclined surface is formed in which the protruding height relative to the surface 102 increases continuously.

  Here, the length of the side 104b (the height of the inclined surface formed on the nozzle surface 102) b is preferably about 0.2 mm to 0.5 mm. This b is preferably larger, but it must be set smaller than the distance between the nozzle surface 102 and the recording medium so that the nozzle surface 102 does not contact the recording medium when the head 100 ejects ink.

  Further, it is preferable that the length of the side 104a (the length of the inclined surface formed on the nozzle surface 102) is as large as possible without affecting ink ejection.

  Note that the liquid film guide member 104 may not have a triangular prism shape. For example, a wedge shape in which the surface C is a curved surface may be used. Further, as shown in FIG. 1D, the liquid film guiding member 104 may have a triangular pyramid shape. By adopting the triangular pyramid shape, the residue of the cleaning liquid can be concentrated at one point. Further, the liquid film guide member 104 may have a quadrangular prism shape as shown in FIG.

  Furthermore, instead of joining the liquid film guiding member 104 to the nozzle surface 102 of the head 100, an inclined surface that protrudes toward the nozzle surface 102 toward the end of the nozzle surface 102 may be formed integrally with the nozzle surface 102. .

  Next, a cleaning apparatus for cleaning the nozzle surface 102 of the head 100 shown in FIG. 1 will be described with reference to FIG.

  FIG. 2 is a diagram showing cleaning of the head 100 in the cleaning apparatus 110, and FIGS. 2A to 2D show a dip type cleaning process similar to FIGS. 11A to 11D, respectively. Yes.

  The cleaning device 110 includes a lifting mechanism (not shown) in addition to the head 100 and the cleaning liquid tank 210. The cleaning device 110 is controlled by a control device (not shown).

  The cleaning liquid tank 210 is previously filled with a cleaning liquid. Here, the nozzle surface 102 of the head 100 is immersed in the cleaning liquid as shown in FIG. 2A by lowering the head 100 relative to the cleaning liquid tank 210 by the lifting mechanism. position). At this time, since the nozzle formation region of the nozzle surface 102 is immersed (contacted) in the cleaning liquid, the entire inclined surface (liquid film guiding member 104) protruding with respect to the nozzle surface 102 is immersed in the cleaning liquid. Further, the nozzle formation region of the nozzle surface 102 is kept substantially parallel to the cleaning liquid surface of the cleaning liquid tank 210.

  Thus, the nozzle surface 102 is cleaned with the cleaning liquid by immersing the nozzle surface 102 in the cleaning liquid. When dirt (ink) adhering to the nozzle surface 102 is not completely dissolved by the cleaning liquid, the nozzle surface 102 may be wiped while being immersed in the cleaning liquid.

  When the cleaning of the nozzle surface 102 is completed, the head 100 is pulled up from the cleaning liquid tank 210 at a predetermined rising speed by the lifting mechanism. At this time, the nozzle formation region of the nozzle surface 102 is pulled up in a state where it is kept substantially parallel to the cleaning liquid surface.

  In the process of pulling up the head 100, as shown in FIG. 2B, when the gap between the nozzle surface 102 and the liquid surface of the cleaning liquid is about 1 mm, the nozzle surface 102 and the cleaning liquid surface are A liquid film of cleaning liquid is generated at the interface.

  When the head 100 is further raised from this state, the gap between the nozzle surface 102 and the cleaning liquid surface is further widened, and the nozzle surface 102 and the cleaning liquid surface are separated.

  Then, due to the cohesive force of the cleaning liquid, as shown in FIG. 2C, the generated liquid film is guided to the liquid film guiding member 104, which is the narrowest space between the separated nozzle surface 102 and the cleaning liquid surface, and gathers. Go.

  When the head 100 is further raised from this state, as shown in FIG. 2D, the liquid film is divided at the liquid film guiding member 104, and a cleaning liquid residue is generated on the liquid film guiding member 104. Thereafter, the head 100 stops (standby position).

  As described above, according to the cleaning apparatus of the present embodiment, the liquid film generated when the nozzle surface 102 and the cleaning liquid surface are separated is guided to the liquid film guide member 104 provided at the end of the nozzle surface 102. A residue of the cleaning liquid can be generated in the liquid film guiding member 104. Therefore, no residue is generated in other areas of the nozzle surface 102. As a result, the cleaning quality can be improved.

Here, the rising speed of the head 100 will be described. The liquid film holding time at the end of the head 100 where the liquid film guiding member 104 is not provided is t1 [s], and the liquid film holding time at the end where the liquid film guiding member 104 is provided is t2 [s. ], The liquid film holding height when the nozzle surface 102 is separated from the cleaning liquid is h [mm], and the aggregation speed of the cleaning liquid film on the nozzle surface 102 is μ [mm / s]. Since the distance from the end where the film guiding member 104 is not provided to the end where the liquid film guiding member 104 is provided is L [mm], in order to guide the cleaning liquid residue to the liquid film guiding member 104 Is
t2-t1> L / μ (Formula 1)
It is necessary to satisfy the relationship.

Here, if the rising speed of the head 100 is v [mm / s],
t1 = h / v (Formula 2)
t2 = (h + b) / v (Formula 3)
It can be expressed as.

From these equations, the rising speed v of the head 100 is
v <b · μ / L (Formula 4)
It is expressed.

  Therefore, by providing the liquid film guiding member 104 at one end in the longitudinal direction of the head 100 and raising the head 100 at a speed satisfying (Equation 4), the liquid film of the cleaning liquid can be guided to the liquid film guiding member 104. . As a result, no residue is generated in other regions of the nozzle surface 102.

  It should be noted that the head 100 may not be raised at a constant speed. In addition, after the liquid film is generated after the head 100 starts to rise, the head 100 is once stopped, and the liquid film at the end of the nozzle surface 102 where the liquid film guiding member 104 is not formed is divided (broken). You may raise it again.

  In the present embodiment, the nozzle surface 102 (nozzle formation region) is cleaned by immersing the nozzle surface 102 in the cleaning liquid filled in the cleaning liquid tank 210. However, a method for applying the cleaning liquid to the nozzle surface 102 is described here. It is not limited.

  For example, the cleaning liquid may be applied to the nozzle surface 102 by forming a thin layer of the cleaning liquid on a flat surface such as a flat plate member and bringing the nozzle surface 102 into contact with the cleaning liquid layer.

  FIG. 3 is a schematic diagram illustrating a state in which the nozzle surface 102 of the head 100 is brought into contact with the cleaning liquid layer 222 formed on the flat plate 220. As shown in FIG. 3A, as in the case of using the cleaning liquid tank 210, it is preferable that the entire inclined surface (liquid film guiding member 104) protruding with respect to the nozzle surface 102 is immersed in the cleaning liquid. . That is, the height of the cleaning liquid layer is preferably higher than the height b of the liquid film guiding member 104.

  If at least a part of the inclined surface formed by the liquid film guiding member 104 is in contact with the cleaning liquid layer, the liquid film generated at the time of separation can be guided to the liquid film guiding member 104. For example, as shown in FIG. 3B, a mode in which a part of the inclined surface formed by the liquid film guiding member 104 contacts the cleaning liquid layer 222 is possible.

  3B, since the cleaning liquid on the flat plate 220 is transmitted through the liquid film guiding member 104 and flows out from the end of the flat plate 220, the cleaning liquid layer 222 is appropriately formed. Cannot be formed. Therefore, the cleaning liquid layer 222 is dynamically formed by replenishing the cleaning liquid as needed, or the flat plate 220 is inclined so that the cleaning liquid does not flow out (in the example of FIG. 3B, the left side is inclined downward). ) Is required.

  In the present embodiment, the liquid film guide member 104 is provided at one end in the longitudinal direction, but may be provided at one end in the lateral direction. The ascending speed of the head 100 when it is provided at one end in the short direction may be calculated by replacing L in (Equation 4) with W.

  When it is provided at one end in the longitudinal direction, an efficient liquid film can be guided. Further, when it is provided at one end in the short direction, the rising speed of the head 100 can be increased, and the liquid film can be guided in a short time. Therefore, productivity can be improved.

  Further, the liquid film guiding member 104 may be provided at both ends of the nozzle surface 102 instead of one end. When provided at both ends, L in (Expression 4) is half. By guiding the liquid film to both ends, the rising speed of the head 100 can be increased, and the liquid film can be guided in a short time. As a result, productivity can be improved.

[Device configuration of inkjet recording apparatus]
Next, an ink jet recording apparatus to which the present invention is applied will be described. 4, 5, and 6 are a front view, a plan view, and a side view, respectively, showing a configuration of a main part of the ink jet recording apparatus.

  As shown in FIG. 1, the inkjet recording apparatus 10 is a single-pass line printer, and mainly includes a sheet conveying mechanism 20 that conveys a sheet (sheet) P that is a recording medium, and a sheet conveying mechanism 20. Maintenance of the head unit 30 that ejects cyan (C), magenta (M), yellow (Y), and black (K) ink droplets toward the transported paper P, and each head mounted on the head unit 30 And a nozzle surface wiping device 80 that cleans the nozzle surface of each head mounted on the head unit 30.

  The paper transport mechanism 20 is constituted by a belt transport mechanism, and adsorbs the paper P to the traveling belt 22 and transports the paper P horizontally.

  The head unit 30 mainly includes a head 32C that ejects cyan ink droplets, a head 32M that ejects magenta ink droplets, a head 32Y that ejects yellow ink droplets, and a head 32K that ejects black ink droplets. The head support frame 38 to which the heads 32C, 32M, 32Y, and 32K are attached, and a head support frame moving mechanism (not shown) that moves the head support frame 38 are configured.

  The heads (inkjet heads) 32C, 32M, 32Y, and 32K are constituted by line heads corresponding to the maximum paper width of the paper P to be printed. Since the configurations of the heads 32C, 32M, 32Y, and 32K are the same, in the following, they are described as the heads 32 unless otherwise distinguished.

  The head 32 (32C, 32M, 32Y, 32K) is formed in a rectangular block shape, and a nozzle surface 33 (33C, 33M, 33Y, 33K) is formed on the bottom thereof.

  FIG. 7 is a perspective view of the head 32. The figure shows a state where the nozzle surface 33 is looked up from below the head 32 (obliquely downward direction). The head 32 is formed by connecting a plurality of head modules in the width direction of the paper P and connecting them, and FIG. 7 shows an example in which 17 head modules are connected.

  The nozzle surface 33 includes a nozzle plate 34, a wing part 35, and an end cap part 36. A liquid film guiding member 104 is provided on the end cap portion 36 at one end of the nozzle surface 33.

  FIG. 8 is a plan view of the nozzle plate 34 on the nozzle surface 33 (viewed from the ejection side), and here, only one head module is shown. Here, although the number of nozzles is omitted, for example, 32 × 64 nozzles N are two-dimensionally arranged on the ink ejection surface of one head module.

  In FIG. 8, the Y direction is the feeding direction (sub-scanning direction) of the recording medium (paper), and the X direction is the width direction (main scanning direction) of the recording medium. The head module has an end surface on the long side along the v direction having an inclination of angle γ with respect to the X direction, and an end surface on the short side along the w direction having an inclination of angle α with respect to the Y direction. The plane shape of the parallelogram having As shown in FIG. 7, by connecting a plurality of such head modules in the X direction (paper width direction), a nozzle row that covers the entire drawing range with respect to the paper width is formed. A full-line head capable of recording an image with a recording resolution (eg, 1200 dpi) is configured.

  Further, the head 32 of the present embodiment discharges ink droplets from the nozzles N by a so-called piezo method. Each nozzle N communicates with a pressure chamber, and ink droplets are ejected from the nozzle N by vibrating the wall surface of the pressure chamber with a piezo element. The ink ejection method is not limited to this, and a thermal ejection method may be employed.

  The head support frame 38 includes a head attachment portion (not shown) for attaching each head 32. Each head 32 is detachably attached to the head attachment portion.

  Each head 32 attached to the head support frame 38 is disposed orthogonal to the transport direction of the paper P. Further, the paper P is arranged in a predetermined order at a constant interval along the conveyance direction of the paper P (in this example, the paper P is arranged in the order of cyan, magenta, yellow, and black).

  The head mounting portion is provided on the head support frame 38 so as to be movable up and down, and is moved up and down by a lifting mechanism (not shown). Each head 32 attached to the head attaching portion is raised and lowered vertically with respect to the transport surface of the paper P by this lifting mechanism.

  The head support frame moving mechanism slides the head support frame 38 horizontally in a direction perpendicular to the transport direction of the paper P at a position above the paper transport mechanism 20.

  The head support frame moving mechanism includes, for example, a ceiling frame that is horizontally installed across the paper transport mechanism 20, a guide rail laid on the ceiling frame, a traveling body that slides on the guide rail, and its traveling It is comprised by the drive means (for example, feed screw mechanism etc.) which moves a body along a guide rail. The head support frame 38 is attached to the traveling body and slides horizontally.

  The head support frame 38 is driven by the head support frame moving mechanism, and is provided so as to be movable between a predetermined “image recording position” and “maintenance position”.

  The head support frame 38 is disposed above the paper transport mechanism 20 when positioned at the image recording position. As a result, printing can be performed on the paper P transported by the paper transport mechanism 20.

  On the other hand, when it is located at the maintenance position, it is disposed at the installation position of the cleaning liquid tank 40.

  The cleaning liquid tank 40 is provided in such a size that the four heads 32C, 32M, 32Y, and 32K can be immersed in the cleaning liquid at the same time. In addition, you may provide four tanks which can immerse each head 32C, 32M, 32Y, 32K separately.

  The cleaning liquid tank 40 is filled with a cleaning liquid by a cleaning liquid supply mechanism (not shown). The cleaning liquid tank 40 is configured to be movable up and down by an elevating mechanism 42. Accordingly, the contact position where the nozzle surface 33 is immersed in the cleaning liquid in a state where the cleaning liquid surface of the cleaning liquid tank 40 and the nozzle surface 33 of the head 32 face each other in parallel, and the standby where the cleaning liquid surface is separated from the nozzle surface 33. It is possible to move between positions (non-contact positions).

  Instead of moving the cleaning liquid tank 40 up and down, the head 32 may be moved up and down to move between the contact position and the standby position.

  The elevating mechanism 42 is configured to be able to adjust the elevating speed of the cleaning liquid tank 40. As described above, the speed at which the nozzle surface 33 is separated from the cleaning liquid surface needs to satisfy (Equation 4). Therefore, the moving speed from the contact position to the standby position is appropriately set according to the length L of the head 100, the height b of the liquid film guiding member 104, and the aggregation speed μ of the cleaning liquid film.

  The aggregation rate μ of the cleaning liquid film varies depending on the ink characteristics. Here, since the four heads 32C, 32M, 32Y, and 32K are simultaneously moved from the contact position to the standby position, it is necessary to match the speed at this time with the ink having the slowest aggregation speed μ of the cleaning liquid film.

  A nozzle surface wiping device 80 is disposed between the image recording position and the maintenance position. The nozzle surface wiping device 80 wipes the nozzle surface 33 of the head 32 while the head support frame 38 moves from the maintenance position to the image recording position.

  The nozzle surface wiping device 80 mainly includes wiping units 84C, 84M, 84Y, and 84K attached to the wiping device main body frame 82, and a wiping device main body lifting mechanism (not shown) that lifts and lowers the wiping device main body frame 82. .

  The wiping units 84 </ b> C, 84 </ b> M, 84 </ b> Y, 84 </ b> K are provided for each head, and are installed on the wiping device main body frame 82 according to the installation interval of the heads 32. In addition, since the structure of each wiping unit 84C, 84M, 84Y, 84K is the same, the structure is demonstrated as the wiping unit 84 here.

  FIG. 9 is a schematic diagram illustrating a schematic configuration of the wiping unit 84. As shown in the figure, the wiping unit 84 mainly includes a feeding shaft 88 that feeds the wiping web 86, a winding shaft 90 that winds the wiping web 86, and a winding motor (not shown) that rotationally drives the winding shaft 90. ), A set of feeding guides 94 and 94 for guiding the wiping web 86 fed from the feeding shaft 88 so as to be wound around the pressing roller 92, and the wiping web 86 wound around the pressing roller 92 as a winding shaft. And a set of winding guides 96 and 96 for guiding them to be wound around 90.

  The wiping web 86 is formed of a sheet made of knitting or weaving using ultra fine fibers such as PET, PE, NY, and is formed in a strip shape having a width corresponding to the width of the nozzle surface 33 of the head 32. The wiping web 86 is provided in a state in which the wiping web 86 is wound around the feeding shaft 88 in a roll shape and the tip is fixed to the winding shaft 90.

  The operation of the nozzle surface wiping device 80 is controlled by a control device (not shown) that controls the entire inkjet recording device 10.

  The entire nozzle surface wiping device 80 is configured to be movable up and down by a wiping device main body lifting mechanism. The nozzle surface wiping device 80 is located at a predetermined standby position except during cleaning, and is positioned at a predetermined operation position that is a position raised by a predetermined amount from the standby position during cleaning.

  In a state where the nozzle surface wiping device 80 is located at the operating position, the wiping units 84 can wipe the nozzle surfaces 33 of the heads 32. That is, when the head 32 passes through each wiping unit 84, the wiping web 86 wound around the pressure roller 92 can be pressed against the nozzle surface 33.

  Instead of using a web, the nozzle surface 33 may be wiped with a blade. Alternatively, only the liquid film guiding member 104 may be wiped or sucked. With this configuration, the residue generated on the liquid film guiding member 104 can be efficiently recovered (removed).

  Further, the ink jet recording apparatus 10 may not include the nozzle surface wiping device 80. For example, when using a cleaning liquid that can completely dissolve the ink adhered to the nozzle surface 33, it is possible to record an image at the image recording position as it is without wiping after cleaning with the cleaning liquid at the maintenance position. .

[Other Embodiments]
As shown in FIG. 10, even when the liquid film guiding member 104 is not provided on the nozzle surface 102 of the head 100, the nozzle surface 102 is inclined from the cleaning liquid surface when the head 100 is pulled up from the cleaning liquid tank 210. It is also possible to induce a liquid film at the lower edge of the nozzle surface 102.

  It should be noted that the above embodiments can be combined as appropriate.

  As described above, according to the present invention, the liquid film generated when the nozzle surface and the cleaning liquid surface are separated from each other is guided to the liquid film guide member provided at the end of the nozzle surface, and the cleaning liquid residue is liquidated. Since it is generated in the film guiding member, the cleaning quality can be improved in the dip type head maintenance system. Thereby, the discharge stability of the nozzle can be improved.

<Appendix>
As will be understood from the description of the embodiment described in detail above, this specification includes disclosure of various technical ideas including the invention described below.

  (Invention 1): An inkjet head having a nozzle surface composed of a nozzle formation region and a region other than the nozzle formation region, a cleaning liquid holding unit that holds a cleaning liquid that can be contacted by the nozzle surface, and the nozzle surface and the cleaning holding unit. Lifting means for raising and lowering the inkjet head relative to the cleaning liquid holding means in a state where the cleaning liquid surface to be held is substantially parallel to the nozzle, and a contact position for bringing the nozzle surface into contact with the cleaning liquid and the nozzle Elevating means for elevating and lowering a surface to a non-contact position that does not contact the cleaning liquid, and the inkjet head is an inclined surface continuous with the nozzle surface at at least one end of the nozzle surface, The nozzle surface has an inclined surface that protrudes toward the end, and the nozzle surface moves away from the cleaning liquid surface. A cleaning liquid film remaining on the surface, characterized in that to guide the inclined surface.

  According to the first aspect, when the nozzle surface is separated from the cleaning liquid surface, the cleaning liquid film remaining on the nozzle surface is guided to the inclined surface continuous with the nozzle surface, so that the cleaning quality is improved in the dip type head maintenance system. Discharge stability can be improved.

  (Invention 2): In the inkjet head cleaning device of Invention 1, the inclined surface is formed by a wedge-shaped member joined to the nozzle surface.

  Thereby, an inclined surface can be formed appropriately.

  (Invention 3): In the inkjet head cleaning device of Invention 1 or 2, the inkjet head has the inclined surface at least at one end in the longitudinal direction of the nozzle surface.

  Thereby, a liquid film can be efficiently induced.

  (Invention 4): In the inkjet head cleaning device according to any one of Inventions 1 to 3, the height of the inclined surface from the nozzle surface is b, the aggregation rate of the cleaning liquid film is μ, and the distance between both ends of the inkjet head Is L, the ascending speed v of the inkjet head by the elevating means when the nozzle surface is separated from the cleaning liquid surface satisfies the relationship of v <b · μ / L.

  Thereby, a liquid film can be induced | guided | derived appropriately.

  (Invention 5): In the inkjet head cleaning device according to any one of Inventions 1 to 4, the inclined surface is lyophilic with respect to the cleaning liquid.

  Thereby, a liquid film can be induced | guided | derived appropriately.

  (Invention 6): The inkjet head cleaning device according to any one of Inventions 1 to 5, wherein the inkjet head has inclined surfaces at both ends of the nozzle surface.

  Thereby, the relative ascending speed of the inkjet head can be increased, and the liquid film can be induced in a short time.

  (Invention 7): The inkjet head cleaning device according to any one of Inventions 1 to 6, further comprising cleaning liquid removing means for wiping or sucking the inclined surface.

  Thereby, the cleaning liquid guided to the inclined surface can be removed.

  (Invention 8): In the ink jet head cleaning device according to any one of Inventions 1 to 7, the cleaning liquid holding means is a cleaning liquid tank filled with a cleaning liquid.

  Thereby, it is possible to appropriately hold the cleaning liquid.

  (Invention 9): In the inkjet head cleaning device according to any one of Inventions 1 to 7, the cleaning liquid holding means is a flat plate member having a cleaning liquid layer formed on a surface thereof.

  Thereby, it is possible to appropriately hold the cleaning liquid.

  (Invention 10): Conveying means for conveying a medium, an inkjet head for recording an image by ejecting ink droplets onto the medium conveyed by the conveying means, and a nozzle surface of the inkjet head according to Inventions 1 to 9 An inkjet recording apparatus comprising: a cleaning device for any inkjet head.

  By providing the inkjet head cleaning device, an inkjet recording device with improved ejection stability can be provided.

  (Invention 11): a nozzle surface comprising a nozzle formation region and a region other than the nozzle formation region, and an inclined surface provided at one end of the nozzle surface and in a region other than the nozzle formation region, the inclined surface Is an inclined surface that is continuous with the nozzle surface, and protrudes from the nozzle surface toward the end of the nozzle surface.

  According to the eleventh aspect of the present invention, the nozzle surface is provided with an inclined surface provided in an area other than the nozzle formation region, and the inclined surface is an inclined surface continuous with the nozzle surface, Since it protrudes toward the nozzle surface as it goes to the end, when the nozzle surface is separated from the cleaning liquid surface in dip type head maintenance, the cleaning liquid film remaining on the nozzle surface is guided to an inclined surface continuous with the nozzle surface. Therefore, the cleaning quality can be improved and the ejection stability can be improved.

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device, 20 ... Paper conveyance mechanism, 30 ... Head unit, 32 (32C, 32M, 32Y, 32K), 100 ... Head, 33, 102 ... Nozzle surface, 34 ... Nozzle plate, 35 ... Wing part, 36 ... End cap part, 40, 210 ... Cleaning liquid tank, 42 ... Elevating mechanism, 80 ... Nozzle surface wiping device, 84 (84C, 84M, 84Y, 84K) ... Wiping unit, 86 ... Wiping web, 104 ... Liquid film guide member, 110 ... Cleaning device

Claims (11)

An inkjet head having a nozzle surface composed of a nozzle formation region and a region other than the nozzle formation region;
Cleaning liquid holding means for holding a cleaning liquid that can be contacted by the nozzle surface;
Lifting and lowering means for moving the inkjet head relatively up and down with respect to the cleaning liquid holding means in a state where the nozzle forming region and the cleaning liquid surface held by the cleaning liquid holding means are substantially parallel to each other; Lifting means for moving up and down between a contact position for contacting with the cleaning liquid and a non-contact position for not contacting the nozzle surface with the cleaning liquid;
With
The inkjet head has an inclined surface that is continuous with the nozzle surface at at least one end of the nozzle surface, and protrudes with respect to the nozzle surface toward the end of the nozzle surface. A cleaning device for an inkjet head, wherein a cleaning liquid film remaining on the nozzle surface is guided to the inclined surface when the cleaning liquid surface is separated from the cleaning liquid surface.   The inkjet head cleaning apparatus according to claim 1, wherein the inclined surface is formed by a wedge-shaped member joined to the nozzle surface.   The inkjet head cleaning apparatus according to claim 1, wherein the inkjet head has the inclined surface at at least one end in a longitudinal direction of the nozzle surface. When the height of the inclined surface from the nozzle surface is b, the aggregation rate of the cleaning liquid film is μ, and the distance between one end and the other end of the inkjet head having the inclined surface is L, the nozzle surface is the cleaning liquid. The relative ascending speed v of the inkjet head by the elevating means when being separated from the surface is:
v <b · μ / L
The inkjet head cleaning device according to claim 1, wherein the relationship is satisfied.   The inkjet head cleaning device according to claim 1, wherein the inclined surface is lyophilic with respect to the cleaning liquid.   The inkjet head cleaning apparatus according to claim 1, wherein the inkjet head has the inclined surfaces at both ends of the nozzle surface.   The inkjet head cleaning apparatus according to claim 1, further comprising a cleaning liquid removing unit that wipes or sucks the inclined surface.   8. The ink jet head cleaning apparatus according to claim 1, wherein the cleaning liquid holding means is a cleaning liquid tank filled with a cleaning liquid.   8. The inkjet head cleaning apparatus according to claim 1, wherein the cleaning liquid holding means is a flat plate member having a cleaning liquid layer formed on a surface thereof. Transport means for transporting media;
An inkjet head that records an image by ejecting ink droplets onto a medium conveyed by the conveying means;
The inkjet head cleaning device according to claim 1, wherein the nozzle surface of the inkjet head is cleaned.
An ink jet recording apparatus comprising: A nozzle surface composed of a nozzle formation region and a region other than the nozzle formation region;
One end of the nozzle surface, an inclined surface provided in a region other than the nozzle formation region,
With
The inkjet head according to claim 1, wherein the inclined surface is an inclined surface continuous with the nozzle surface and protrudes from the nozzle surface toward an end of the nozzle surface.

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