JP2014051028A - Droplet discharge head, and maintenance system of nozzle surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently collect an ink and cleaning liquid which adhere to a nozzle surface of a droplet discharge head.SOLUTION: A droplet discharge head 72, in which a plurality of head modules 72-i on which a plurality of nozzles discharging droplet are arranged are continuously joined together, includes an absorbable member 102, which has a porous structure, between the head modules 72-i which are joined together. In addition, a maintenance system of a nozzle surface includes: the droplet discharge head and a wiping device to wipe the nozzle surface.

Description

  The present invention relates to a droplet discharge head and a nozzle surface maintenance system, and more particularly, to a droplet discharge head and a nozzle surface maintenance system formed by connecting a plurality of head modules.

  Excess ink or cleaning liquid during maintenance adheres to the nozzle surface of an ink jet head used in an image recording apparatus, for example, an ink jet recording apparatus. Therefore, how to efficiently remove excess ink and cleaning liquid is a very important issue in terms of the life and reliability of the inkjet head, printing performance, and whether or not the recording medium is contaminated.

  For example, in Patent Document 1 below, the ink discharge port surface is treated to be ink repellent, the periphery thereof is protected by an ink-philic member protruding in the ink discharge direction, and the porous elastic body is pressed at the maintenance position. Describes an apparatus for collecting and removing excess ink.

  In Patent Document 2, as an example of a line head in which a plurality of head modules are arranged in a line, ink attached to the nozzle surface is wiped by sliding a wiper blade. A liquid ejecting apparatus is described which is absorbed by an ink absorber provided along the side surface in the longitudinal direction of the ink jet recording head.

JP 2006-44163 A JP 2008-143039 A

  However, in the apparatus described in Patent Document 1, since the liquid is recovered only by the maintenance member, the surplus ink cannot be completely recovered due to the shape of the uneven mechanism around the nozzle, and the ink is discharged to the ejection surface. It remained. Therefore, in the next discharge, it causes discharge bending and satellite, or causes the remaining ink to fall.

  Further, in the apparatus described in Patent Document 2, a groove is provided at the joint of the head module, and ink is easily collected in the groove, so that the groove is provided on the side surface in the longitudinal direction of the wiper blade and the line head. Only the absorber, that is, the absorber provided in parallel with the passing direction of the maintenance member, could not completely remove the ink accumulated in the groove. When the ink could not be removed, they gathered and dropped, causing the recording medium to become dirty.

  The present invention has been made in view of such circumstances, and provides a droplet discharge head and a nozzle surface maintenance system capable of efficiently recovering ink and cleaning liquid adhering to the nozzle surface of the droplet discharge head. For the purpose.

  In order to achieve the above object, the present invention is a droplet discharge head in which a plurality of head modules in which a plurality of nozzles for discharging liquid are arranged are continuously connected, and between the connected head modules, A droplet discharge head including an absorbent member having a porous structure is provided.

  According to the present invention, since the absorbent member having a porous structure is provided between the joined head modules, the excess ink remaining on the nozzle surface of the head module or the cleaning liquid during maintenance is transferred between the head modules. It can be made to absorb with an absorptive member. Moreover, since the absorptive member has a porous structure, it can be easily absorbed by capillary pressure. Therefore, excess ink and cleaning liquid adhering around the nozzle can be easily removed.

  In the droplet discharge head according to another aspect of the present invention, the absorbent member is preferably wrapped in a shape maintaining member that maintains the shape of the absorbent member.

  According to the droplet discharge head according to another aspect of the present invention, since the absorbent member is wrapped in the shape maintaining member, the absorbent member can be prevented from being deformed, and the absorbent member By hitting the head module, it is possible to prevent reabsorption of the absorbed ink and cleaning liquid.

  In the liquid droplet ejection head according to another aspect of the present invention, the shape maintaining member is preferably formed of a metallic or resinous material.

  According to the liquid droplet ejection head according to another aspect of the present invention, a stronger shape maintaining member can be produced by forming the shape maintaining member from a metallic or resinous material. It is possible to prevent the shape of the sex member from changing.

  In the droplet discharge head according to another aspect of the present invention, it is preferable that the shape maintaining member is detachably disposed between the connected head modules.

  According to the droplet discharge head according to another aspect of the present invention, since the shape maintaining member is detachably disposed between the head modules, the absorbent member can be easily replaced.

  In the liquid droplet ejection head according to another aspect of the present invention, the shape maintaining member is preferably a spacer that can determine the position of the head module by contacting the adjacent head module.

  The droplet discharge head according to another aspect of the present invention can be used as a spacer capable of positioning the head module by bringing the shape maintaining member into contact with the adjacent head module. Therefore, the head module can be easily positioned after replacing the head module.

  In the droplet discharge head according to another aspect of the present invention, it is preferable that the abutting portion that abuts the head module of the shape maintaining member has a circular shape with a distance between adjacent head modules as a diameter.

  According to the droplet discharge head according to another aspect of the present invention, since the contact portion that contacts the head module of the shape maintaining member is circular with the distance between adjacent head modules as a diameter, the width between the head modules An absorptive member can be arranged by arranging a plurality of shape maintenance members in the direction. Therefore, when the shape maintaining member is formed of a single member, it is necessary to manufacture the head module in the entire width direction so that the position between the head modules can be determined. Thus, the position of the head module can be determined even when the accuracy of the individual shape maintaining member is low as compared with the case of forming with a single member.

  The droplet discharge head according to another aspect of the present invention preferably includes an opening that opens the absorbent member to the atmosphere on the side opposite to the nozzle of the shape maintaining member.

  According to the droplet discharge head according to another aspect of the present invention, since the shape maintaining member has the opening that opens the absorbent member to the atmosphere, evaporation of the liquid absorbed by the absorbent member can be promoted. The frequency of replacement of the absorbent member can be reduced.

  In the droplet discharge head according to another aspect of the present invention, it is preferable that dry air is allowed to flow to the open portion side of the shape maintaining member.

  According to the droplet discharge head according to another aspect of the present invention, the dry air is allowed to flow toward the opening of the shape maintaining member, so that the absorbent member can be efficiently dried and the absorbed liquid can be evaporated. Can be urged.

  In the liquid droplet ejection head according to another aspect of the present invention, the shape maintaining member preferably has a handle.

  According to the droplet discharge head according to another aspect of the present invention, the shape maintaining member and the absorbent member can be easily removed by providing the handle on the shape maintaining member, and the shape maintaining member and the absorbent member are exchanged. Can be easily performed.

  In the droplet discharge head according to another aspect of the present invention, the absorbent member preferably has a handle.

  According to the droplet discharge head according to another aspect of the present invention, it is possible to easily replace only the absorbent member by providing a handle on the absorbent member.

  In the droplet discharge head according to another aspect of the present invention, the side surface of the head module is preferably hydrophilic.

  According to the liquid droplet ejection head according to another aspect of the present invention, since the side surface of the head module is hydrophilic, excess ink and cleaning liquid adhering to the nozzle surface can be drawn between the head modules. Then, the liquid can be efficiently removed by absorbing and removing with the absorbent member.

  In order to achieve the above object, the present invention includes the above-described droplet discharge head, and a wiping device for wiping the nozzle surface on which the nozzle is formed along the arrangement direction of the head module of the droplet discharge head. A maintenance system for the nozzle surface is provided.

  According to the present invention, the wiping device for wiping the nozzle surface along the arrangement direction of the head modules is provided, and the absorbent member is provided between the head modules in the width direction. Accordingly, when the nozzle surface is wiped, excess ink or cleaning liquid can be absorbed by the absorbent member provided between the head modules in the wiping direction, so that the nozzle surface can be efficiently wiped.

  According to the droplet discharge head and the nozzle surface maintenance system of the present invention, the absorbent member having a porous structure is provided between the plurality of connected head modules. Since the adhering excess ink and cleaning liquid can be absorbed by the absorbent member, the liquid adhering to the nozzle surface can be effectively removed.

1 is an overall configuration diagram of an ink jet recording apparatus. It is a top view which shows the structural example of the inkjet head shown in FIG. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 3 is a plan perspective view of the head module shown in FIG. 2. It is a side view of the joint part of the head module of an inkjet head. It is the top view which shows embodiment of a shape maintenance member, a front view, and a side view. It is the top view which shows other embodiment of a shape maintenance member, a front view, and a side view. It is a figure which shows embodiment of an absorption member. It is a side view which shows schematic structure of the drawing part of an inkjet recording device. It is a front view of the drawing part of an inkjet recording device.

  Preferred embodiments of a droplet discharge head and a nozzle surface maintenance system according to the present invention will be described below with reference to the accompanying drawings. In the following, an inkjet head will be described as an example of a droplet discharge head. An ink jet recording apparatus having this ink jet head will be described.

<< Overall configuration of inkjet recording apparatus >>
First, the overall configuration of the ink jet recording apparatus will be described. FIG. 1 is a configuration diagram showing the overall configuration of the ink jet recording apparatus.

  The inkjet recording apparatus 10 includes a plurality of colors from inkjet heads 72M, 72K, 72C, and 72Y on a recording medium 24 (sometimes referred to as “paper” for convenience) held on an impression cylinder (drawing drum 70) of the drawing unit 16. Is an impression cylinder direct drawing type ink jet recording apparatus that forms a desired color image by applying ink droplets of the ink. A treatment liquid (here, an aggregating treatment liquid) is applied onto the recording medium 24 before ink droplet ejection, This is an on-demand type image forming apparatus to which a two-liquid reaction (aggregation) method for forming an image on a recording medium 24 by reacting a treatment liquid and an ink liquid is applied.

  As shown in the figure, the ink jet recording apparatus 10 mainly includes a paper feed unit 12, a treatment liquid application unit 14, a drawing unit 16, a drying unit 18, a fixing unit 20, and a discharge unit 22.

(Paper Feeder)
The paper supply unit 12 is a mechanism that supplies the recording medium 24 to the treatment liquid application unit 14, and a recording medium 24 that is a sheet is stacked on the paper supply unit 12. The paper feed unit 12 is provided with a paper feed tray 50, and the recording medium 24 is fed from the paper feed tray 50 to the processing liquid application unit 14 one by one.

  In the inkjet recording apparatus 10 of this example, a plurality of types of recording media 24 having different paper types and sizes (paper sizes) can be used as the recording medium 24. A mode is also possible in which a plurality of paper trays (not shown) are provided in the paper feed unit 12 to separately collect various recording media and the paper to be sent to the paper feed tray 50 is automatically switched from among the plurality of paper trays. In addition, a mode is also possible in which the operator selects or replaces the paper tray as necessary. In this example, a sheet (cut paper) is used as the recording medium 24, but a configuration in which continuous paper (roll paper) is cut to a required size and fed is also possible.

(Processing liquid application part)
The processing liquid application unit 14 is a mechanism that applies the processing liquid to the recording surface of the recording medium 24. The treatment liquid contains a color material aggregating agent that agglomerates the color material (pigment in this example) applied in the ink provided by the drawing unit 16, and the ink comes into contact with the colorant when the treatment liquid comes into contact with the ink. And the solvent are promoted.

  As shown in FIG. 1, the treatment liquid application unit 14 includes a paper feed drum 52, a treatment liquid drum 54, and a treatment liquid application device 56. The treatment liquid drum 54 is a drum that holds and rotates and conveys the recording medium 24. The processing liquid drum 54 is provided with a claw-shaped holding means (gripper) 55 on the outer peripheral surface thereof, and the recording medium 24 is sandwiched between the claw of the holding means 55 and the peripheral surface of the processing liquid drum 54 to thereby remove the recording medium 24. The tip can be held. The treatment liquid drum 54 may be provided with suction holes on the outer peripheral surface thereof and connected to suction means for suction from the suction holes. As a result, the recording medium 24 can be held in close contact with the peripheral surface of the treatment liquid drum 54.

  A processing liquid coating device 56 is provided outside the processing liquid drum 54 so as to face the peripheral surface thereof. The processing liquid coating device 56 includes a processing liquid container in which the processing liquid is stored, an anix roller partially immersed in the processing liquid in the processing liquid container, and the recording medium 24 on the anix roller and the processing liquid drum 54. And a rubber roller that transfers the measured processing liquid to the recording medium 24. According to the processing liquid application device 56, the processing liquid can be applied to the recording medium 24 while being measured.

  The recording medium 24 to which the processing liquid is applied by the processing liquid applying unit 14 is transferred from the processing liquid drum 54 to the drawing drum 70 of the drawing unit 16 via the intermediate transport unit 26.

(Drawing part)
The drawing unit 16 includes a drawing drum (second transport body) 70, a sheet pressing roller 74, and inkjet heads 72M, 72K, 72C, and 72Y. The drawing drum 70 includes a claw-shaped holding means (gripper) 71 on the outer peripheral surface thereof, like the processing liquid drum 54. The recording medium 24 fixed to the drawing drum 70 is conveyed with the recording surface facing outward, and ink is applied to the recording surface from the inkjet heads 72M, 72K, 72C, 72Y.

  Each of the inkjet heads 72M, 72K, 72C, and 72Y is preferably a full-line inkjet recording head (inkjet head) having a length corresponding to the maximum width of the image forming area in the recording medium 24. On the ink ejection surface, a nozzle row in which a plurality of nozzles for ink ejection are arranged over the entire width of the image forming area is formed. Each inkjet head 72M, 72K, 72C, 72Y is installed so as to extend in a direction orthogonal to the conveyance direction of the recording medium 24 (the rotation direction of the drawing drum 70).

  The droplets of the corresponding color ink are ejected from the respective ink jet heads 72M, 72K, 72C, 72Y toward the recording surface of the recording medium 24 held tightly on the drawing drum 70. The ink comes into contact with the treatment liquid previously applied to the recording surface, and the color material (pigment) dispersed in the ink is aggregated to form a color material aggregate. Thereby, the color material flow on the recording medium 24 is prevented, and an image is formed on the recording surface of the recording medium 24.

  In this example, the configuration of CMYK standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink, dark ink, and special colors are used as necessary. Ink may be added. For example, it is possible to add an inkjet head that discharges light-colored ink such as light cyan and light magenta, and the arrangement order of the color heads is not particularly limited.

  The recording medium 24 on which an image is formed by the drawing unit 16 is transferred from the drawing drum 70 to the drying drum 76 of the drying unit 18 via the intermediate conveyance unit 28.

(Drying part)
The drying unit 18 is a mechanism for drying moisture contained in the solvent separated by the color material aggregation action, and includes a drying drum 76 and a solvent drying device 78 as shown in FIG.

  Similar to the treatment liquid drum 54, the drying drum 76 includes a claw-shaped holding unit (gripper) 77 on the outer peripheral surface thereof, and the holding unit 77 can hold the leading end of the recording medium 24.

  The solvent drying device 78 is disposed at a position facing the outer peripheral surface of the drying drum 76, and includes a plurality of IR heaters 82 and hot air ejection nozzles 80 disposed between the IR heaters 82.

  Various drying conditions can be realized by appropriately adjusting the temperature and air volume of the hot air blown toward the recording medium 24 from each hot air jet nozzle 80 and the temperature of each IR heater 82.

  The surface temperature of the drying drum 76 is set to 50 ° C. or higher. Drying is accelerated by heating from the back surface of the recording medium 24, and image destruction during fixing can be prevented. The upper limit of the surface temperature of the drying drum 76 is not particularly limited, but from the viewpoint of safety of maintenance work such as cleaning ink adhering to the surface of the drying drum 76 (preventing burns due to high temperature). It is preferably set to 75 ° C. or lower (more preferably 60 ° C. or lower).

  The recording drum 24 is held on the outer peripheral surface of the drying drum 76 so that the recording surface of the recording medium 24 faces outward (that is, in a state where the recording surface of the recording medium 24 is convex), and is dried while being rotated and conveyed By doing so, it is possible to prevent the recording medium 24 from being wrinkled or lifted, and to reliably prevent uneven drying due to these.

  The recording medium 24 that has been dried by the drying unit 18 is transferred from the drying drum 76 to the fixing drum 84 of the fixing unit 20 via the intermediate conveyance unit 30.

(Fixing part)
The fixing unit 20 includes a fixing drum 84, a halogen heater 86, a fixing roller 88, and an inline sensor 90. Like the processing liquid drum 54, the fixing drum 84 includes a claw-shaped holding unit (gripper) 85 on its outer peripheral surface, and the holding unit 85 can hold the leading end of the recording medium 24.

  With the rotation of the fixing drum 84, the recording medium 24 is conveyed with the recording surface facing outward. The recording surface is preheated by the halogen heater 86, fixed by the fixing roller 88, and by the inline sensor 90. Inspection is performed.

  The halogen heater 86 is controlled to a predetermined temperature (for example, 180 ° C.). Thereby, the recording medium 24 is preheated.

  The fixing roller 88 is a roller member for heating and pressurizing the dried ink to weld the self-dispersing thermoplastic resin fine particles in the ink to form a film of the ink. The fixing roller 88 is configured to heat and press the recording medium 24. Composed. Specifically, the fixing roller 88 is disposed so as to be in pressure contact with the fixing drum 84, and constitutes a nip roller with the fixing drum 84. As a result, the recording medium 24 is sandwiched between the fixing roller 88 and the fixing drum 84 and nipped at a predetermined nip pressure (for example, 0.15 MPa), and a fixing process is performed.

  The fixing roller 88 is configured by a heating roller in which a halogen lamp is incorporated in a metal pipe such as aluminum having good thermal conductivity, and is controlled to a predetermined temperature (for example, 60 to 80 ° C.). By heating the recording medium 24 with this heating roller, thermal energy equal to or higher than the Tg temperature (glass transition temperature) of the thermoplastic resin fine particles contained in the ink is applied, and the thermoplastic resin fine particles are melted. As a result, pressing and fixing are performed on the unevenness of the recording medium 24, and the unevenness of the image surface is leveled to obtain glossiness.

  In the embodiment of FIG. 1, only one fixing roller 88 is provided. However, a configuration in which a plurality of fixing rollers 88 are provided may be employed depending on the thickness of the image layer and the Tg characteristics of the thermoplastic resin fine particles.

  On the other hand, the in-line sensor 90 is a measuring means for measuring a check pattern, a moisture content, a surface temperature, a glossiness, and the like for an image fixed on the recording medium 24, and a CCD line sensor or the like is applied.

  According to the fixing unit 20 configured as described above, the thermoplastic resin fine particles in the thin image layer formed by the drying unit 18 are heated and pressurized by the fixing roller 88 and melted. Can be fixed and fixed. Further, by setting the surface temperature of the fixing drum 84 to 50 ° C. or higher, drying is promoted by heating the recording medium 24 held on the outer peripheral surface of the fixing drum 84 from the back surface, thereby preventing image destruction during fixing. In addition, the image intensity can be increased by the effect of increasing the image temperature.

In addition, when a UV curable monomer is contained in the ink, after the water is sufficiently volatilized in the drying unit, the image is irradiated with UV at the fixing unit equipped with a UV irradiation lamp. The monomer can be cured and polymerized to improve the image strength.

(Discharge part)
As shown in FIG. 1, a discharge unit 22 is provided following the fixing unit 20. The discharge unit 22 includes a discharge tray 92, and a transfer drum 94, a conveyance belt 96, and a tension roller 98 are provided between the discharge tray 92 and the fixing drum 84 of the fixing unit 20 so as to be in contact therewith. It has been. The recording medium 24 is sent to the conveying belt 96 by the transfer drum 94 and discharged to the discharge tray 92.

  Although not shown in the drawing, the ink jet recording apparatus 10 of this example has an ink storage / loading unit for supplying ink to each of the ink jet heads 72M, 72K, 72C, and 72Y, and a treatment liquid application, in addition to the above-described configuration. A means for supplying a processing liquid to the unit 14, and a head maintenance unit for cleaning each of the inkjet heads 72M, 72K, 72C, 72Y (wiping, purging, nozzle suction, etc. of the nozzle surface), A position detection sensor for detecting the position of the recording medium 24, a temperature sensor for detecting the temperature of each part of the apparatus, and the like are provided.

  FIG. 2 is a plan view showing a structural example of the head 72, and is a view of the head 72 as seen from the nozzle surface 72A side. FIG. 3 is a partially enlarged view of FIG.

  As shown in FIG. 2, the head 72 has n head modules 72-i (i = 1, 2, 3,..., N) perpendicular to the transport direction of the longitudinal direction (recording medium 24 (see FIG. 1)). ), And a plurality of nozzles (not shown in FIG. 2) are provided over a length corresponding to the entire width of the recording medium.

  Each head module 72-i is supported by a head module support member 72B from both sides of the head 72 in the short direction. Further, both end portions of the head 72 in the longitudinal direction are supported by a head support member 72D.

  As shown in FIG. 3, each head module 72-i (n-th head module 72-n) has a structure in which a plurality of nozzles are arranged in a matrix. In FIG. 3, an oblique solid line denoted by reference numeral 151A represents a nozzle row in which a plurality of nozzles are arranged in a row.

  4A is a plan perspective view of the head module 72-i, and FIG. 4B is an enlarged view of a part thereof.

  In order to increase the dot pitch formed on the recording medium 24, it is necessary to increase the nozzle pitch in the head 72. As shown in FIGS. 4A and 4B, the head module 72-i of the present example includes a plurality of ink chamber units each including a nozzle 151 serving as an ink discharge port, a pressure chamber 152 corresponding to each nozzle 151, and the like. (Droplet discharge elements as recording element units) 153 has a structure in which the zigzag is arranged in a matrix (two-dimensionally), and thereby, the head longitudinal direction (direction orthogonal to the transport direction of the recording medium 24); High density of the substantial nozzle interval (projection nozzle pitch) projected along the main scanning direction is achieved.

The pressure chamber 152 provided corresponding to each nozzle 151 has a substantially square planar shape, the nozzle 151 is provided at one of the diagonal corners, and the supply port 154 is provided at the other. ing. The shape of the pressure chamber 152 is not limited to this example, and the planar shape may have various forms such as a quadrangle (rhombus, rectangle, etc.), a pentagon, a hexagon, other polygons, a circle, and an ellipse.

  As shown in FIG. 4B, the ink chamber units 153 having such a structure are arranged in a fixed manner along a row direction along the main scanning direction and an oblique column direction having a constant angle θ that is not orthogonal to the main scanning direction. By arranging a large number of patterns in a lattice pattern, the high-density nozzle head of this example is realized.

  That is, with a structure in which a plurality of ink chamber units 153 are arranged at a constant pitch d along the direction of an angle θ with respect to the main scanning direction, the pitch P of the nozzles projected in the main scanning direction is d × cos θ. Thus, in the main scanning direction, each nozzle 151 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, it is possible to realize a high-density nozzle configuration in which the number of nozzle rows projected so as to be aligned in the main scanning direction is 2400 per inch (2400 nozzles / inch).

  In the implementation of the present invention, the nozzle arrangement structure is not limited to the illustrated example, and various nozzle arrangement structures such as an arrangement structure having one nozzle row in the sub-scanning direction can be applied.

  FIG. 5 is a side view of a connecting portion between the head modules 72-i. As shown in FIG. 5, a porous processed absorbent member 102 is provided between the head modules 72-i.

  By providing the absorbing member 102, excess ink and cleaning liquid can be absorbed by the absorbing member 102. By absorbing the excess ink with the absorbing member 102, it is possible to prevent the ink from accumulating and becoming solid between the head modules 72-i and becoming a fixed substance, and damaging the nozzle surface 72A. Further, by absorbing with the absorbing member 102, it is possible to prevent the ink accumulated between the head modules 72-i from dropping as a liquid.

  Moreover, it is preferable that the side surface 104 on the side having the absorbing member 102 of the head module 72-i is subjected to a hydrophilic treatment. By applying a hydrophilic treatment, the hydrophilic end surface draws droplets on the nozzle surface in the gap of the joint of the head module 72-i, and the excess ink and the cleaning liquid are absorbed and removed by the capillary pressure of the absorbing member 102. Can do.

  As shown in FIG. 5, the absorbing member 102 is held between the shape maintaining members 106 and provided between the head modules 72-i. By wrapping the absorbing member 102 with the shape maintaining member 106 as shown in FIG. 5, the deformation of the absorbing member 102 can be reduced, and the absorbing member 102 is pushed by the head module 72-i. It is possible to prevent the absorbed ink and the cleaning liquid from being re-released. The shape maintaining member 106 is detachably disposed between the head modules 72-i. By arranging the shape maintaining member 106 so as to be detachable, the shape maintaining member 106 and the absorbing member 102 can be easily replaced.

  FIG. 6 is a view showing an embodiment of the shape maintaining member. FIG. 6A is a plan view, a front view, and a side view of the shape maintaining member 106 shown in FIG. The shape maintaining member 106 shown in FIG. 6A includes a contact portion 132 that contacts the head module 72-i and a side portion 134 that holds and holds the absorbing member 102. The shape maintaining member 106 is provided so as to be disposed over substantially the entire short direction of the head module 72-i, and the shape maintaining member 106 is sealed on the side opposite to the nozzle surface. Further, in FIG. 6A, a handle 126 is provided on the shape maintaining member 106 so that the shape maintaining member 106 can be easily detached from the connecting portion of the head module 72-i. The replacement work of the member 102 can be simplified. Further, since the shape maintaining member 106 is formed of a highly rigid member, when the head module 72-i is replaced and the inkjet head 72 is assembled, the contact portion 132 of the shape maintaining member 106 is connected to the head module 72- on both sides. By abutting against the abutment surface 105 (shown in FIG. 5) of i, the position of the head module can be assembled with high accuracy, and the positioning accuracy can be ensured. Thus, since the shape maintaining member 106 can be used as a spacer when replacing the head module 72-i, the replacement operation of the head module 72-i can be simplified.

  The shape maintaining member 106 is at least open on the nozzle surface side, and it is only necessary that the absorbing member 102 can absorb ink and cleaning liquid from the opened nozzle surface side, but the side portion 134 of the shape maintaining member 106 is meshed. It is preferable to form a hole or provide a hole since the ink and the cleaning liquid can be absorbed by the absorbing member 102 from the side portion 134 side of the shape maintaining member 106.

  In FIG. 6B, the shape maintaining member 108 is a screw type, and the upper portion of the shape maintaining member 108 (opposite the nozzle surface of the inkjet head) is sealed. As shown in FIG. 6 (b), the shape maintaining member 108 is formed into a screw shape, and a plurality of the screw shape maintaining members 108 are installed in the short direction of the connecting portion of the head module 72-i. In addition, the cleaning liquid can be absorbed. As shown in FIG. 6B, the shape maintaining member 108 is formed in a screw shape, and a plurality of the shape maintaining members 108 are provided, so that the accuracy is improved over the entire short direction of the head module 72-i as compared with the shape maintaining member 106 shown in FIG. Since it is not necessary to prepare well, the positioning accuracy of the head module 72-i can be more easily ensured.

  The shape maintaining member 110 shown in FIG. 6 (c) and the shape maintaining member 112 shown in FIG. 6 (d) are the upper parts of the shape maintaining members 106 and 108 shown in FIGS. 6 (a) and 6 (b). An opening 140 is provided on the side opposite to the nozzle surface 72A when installed between modules. As the shape maintaining members 110 and 112 are opened, it is possible to promote the drying of the liquid absorbed by the absorbing member 102, so that the number of replacement operations of the absorbing member 102 can be reduced. Furthermore, drying from the absorbing member 102 can be promoted by blowing dry air above the shape maintaining members 110 and 112.

  FIG. 6E shows a configuration in which the shape maintaining member 114 is separated so as to sandwich the absorbing member 102. As shown in FIG. 6E, the length l sandwiching the absorbing member 102 can be adjusted by separating the shape maintaining member 114. Therefore, it can be adjusted to a length l suitable for the thickness of the absorbing member 102 used.

  FIG. 6F shows a structure in which a length adjusting member 128 such as a spring or a screw is provided between the separated shape maintaining members 116. By providing the length adjusting member 128, the rigidity of the shape maintaining member 116 can be increased.

  FIG. 6G shows a configuration in which the claw 130 is provided below the shape maintaining member 118 (on the nozzle surface side of the inkjet head). By providing the claw 130, it is possible to prevent the absorbing member 102 provided on the shape maintaining member 118 from dropping.

  6 (e) to 6 (g), since the opposite side to the nozzle surface when the shape maintaining member is installed between the head modules 72-i is open, the absorbing member 102 The drying of the liquid can be promoted.

  The shape maintaining members 120, 122, and 124 in FIGS. 6 (h), 7 (i), and (j) are only contact portions 132 with the head modules of the shape maintaining members in FIGS. 6 (a) to 6 (g). This is the configuration. By adopting the configuration of only the contact portion 132 of the shape maintaining member, handling can be facilitated with a simple configuration. FIG. 6 (h) is obtained by removing the side portion 134 of FIG. 6 (c), and FIG. 7 (j) is obtained by removing the side portion 134 of FIG. 6 (d). FIG. 7 (i) is a configuration in which a length adjusting member 128 is provided on the shape maintaining member 120 of FIG. 6 (h), and the position for holding the absorbing member 102 can be fixed. The rigidity of can be increased.

  Examples of the material of the shape maintaining member include a corrosion-resistant metal material such as SUS, and a resin material such as an epoxy resin and an acrylic photocurable resin material. In the embodiment having the side portion 134, the shape maintaining member is made of a highly rigid material, so that the deformation of the absorbing member 102 can be prevented, and the ink and cleaning liquid absorbed by the absorbing member being pushed. Can be prevented from being re-released.

  As a hydrophilic treatment method applied to the side surface of the head module 72-i, a surface modification method that irradiates excitation light can be used. As the excitation light, energy rays such as ultraviolet rays or oxygen plasma can be used.

  FIG. 8 is a diagram illustrating an example of the shape of the absorbing member 102. FIG. 8A shows a cylindrical absorbing member 102a, which can be used for the screw-type shape maintaining members 108, 112, and 124 shown in FIGS. 6B and 6D. 8 (b) is a sheet-type absorbing member 102b, which can be used for the T-shaped shape maintaining member 106 such as FIGS. 6 (a) and 6 (h) or the rectangular parallelepiped shape maintaining member 120. Further, the absorbing member 102c in FIG. 8C and the absorbing member 102d in FIG. 8D are obtained by changing the shape shown in FIGS. 7B and 7A into a quadrangular pyramid shape and a conical shape. By using the absorbing member (d), a gap is provided between the shape maintaining member and the capillary pressure can be increased, and the liquid absorption efficiency can be improved. Moreover, since the absorption member 102 has the hole 138, absorption of the liquid can be promoted by capillary pressure.

  In addition, as shown in FIG. 5, by providing the absorption member 102 with a handle 136 as a separate member, the replacement work of only the absorption member 102 can be simplified.

  As the absorbent member 102, polyacrylate, polysulfonate, anhydrous maleate, polyacrylamide, polyvinyl alcohol, polyethylene oxide, etc., which are common as high water supply resin SAP (Super Absorbent Polymer), etc. An absorbent member obtained by processing the above material and processing the inside and the surface to be porous can be given.

  The processing method of the absorbent member 102 includes a freeze-drying method using a liquid state change using a freeze dryer, a selective dissolution method represented by salting, sintering of water-absorbing particles, MEMS (Micro Electro Mechanical System) It can be processed by a fine processing technique represented by

  For example, as a salting method, a salt such as sodium chloride is added to a solution obtained by dissolving a resin, which is a material of an absorbent member, in an organic solvent, and then solidified, and then immersed in water to remove the salt. A hole is formed in this part, and a porous body can be formed. In the selective dissolution method, any material that does not dissolve in the solvent at the stage of hardening the resin instead of salt and can be removed later with water can be used. For example, sugar can also be used.

  In the freeze-drying method, the solution in which the resin material is dissolved is frozen and stored in a high vacuum, so that the solvent can be sublimated, and pores are formed in the portion where the solvent is sublimated. Can be formed.

  In the sintering of the water-absorbing particles, the water-absorbing particles are gradually bonded by heating the water-absorbing particles, and the gaps between the water-absorbing particles become pores to form a porous material. As a fine processing technique, a porous body can be formed by forming holes by etching or the like, such as a technique for processing a semiconductor such as silicon.

≪Description of maintenance department≫
Next, the maintenance unit will be described. FIG. 9 is a side view illustrating a schematic configuration of a drawing unit of the ink jet recording apparatus.

  The drawing drum 70 is rotatably provided with both ends of the rotating shaft 218 being pivotally supported by a pair of bearings 222 (see FIG. 10). The pair of bearings 222 are provided on the main body frame 220 of the ink jet recording apparatus, and the drawing drum 70 is attached horizontally by supporting both ends of the rotating shaft 218 on the pair of bearings 222. The rotation shaft 218 is attached in parallel to the installation surface.

  The four inkjet heads 72M, 72K, 72C, 72Y are arranged radially on the concentric circle with the rotation axis 218 of the drawing drum 70 as the center, and are attached to the head support frame 240 as shown in FIG. And arranged around the drawing drum 70.

  The head support frame 240 includes a pair of side plates 242L and 242R provided orthogonal to the rotation shaft 218 of the drawing drum 70, and a connection frame 244 that connects the pair of side plates 242L and 242R at the upper end. ing.

  The pair of side plates 242L and 242R are formed in a plate shape, and are disposed so as to face each other with the drawing drum 70 interposed therebetween. Mounting portions 246M, 246K, 246C, and 246Y for mounting the inkjet heads 72M, 72K, 72C, and 72Y are provided inside the pair of side plates 242L and 242R (in FIG. 10, for the sake of convenience, the mounting portions are mounted). Only 246Y is shown).

  The attachment portions 246C, 246M, 246Y, and 246K are radially arranged on the concentric circle with the rotation axis 218 of the drawing drum 70 as the center at a constant interval. Each inkjet head 72M, 72K, 72C, 72Y has attached portions 248M, 248K, 248C, 248Y (only the attached portion 248Y is shown in FIG. 10 for the sake of convenience) formed at both ends of the inkjet heads 246M, 246K, 246C. By fixing to 246Y, the head support frame 240 is attached. Then, by being attached to the head support frame 240, the respective ink jet heads 72M, 72K, 72C, 72Y are radially arranged on the concentric circle with the rotation axis 218 of the drawing drum 70 as a center at a constant interval.

  The head support frame 240 is guided by a guide rail (not shown) and is slidably provided in parallel with the rotation shaft 218 of the drawing drum 70. Then, it is driven by a linear drive mechanism (not shown) (for example, a feed screw mechanism) and moves between an “image recording position” indicated by a solid line in FIG. 10 and a “maintenance position” indicated by a broken line in FIG.

  Each inkjet head 72M, 72K, 72C, 72Y is disposed around the drawing drum 70 when the head support frame 240 is positioned at the image recording position, and is ready for image recording.

  The maintenance position is set to a position where each inkjet head 72M, 72K, 72C, 72Y is retracted from the drawing drum 70. At this maintenance position, a moisturizing unit 250 for moisturizing each inkjet head 72M, 72K, 72C, 72Y is provided.

  The moisturizing unit 250 includes caps 252M, 252K, 252C, and 252Y (only the cap 252Y is shown for convenience in FIG. 10) that covers the nozzle surfaces of the inkjet heads 72M, 72K, 72C, and 72Y. When the apparatus is stopped for a long time, the nozzle surface is covered with the caps 252M, 252K, 252C, 252Y. Thereby, non-ejection due to drying is prevented.

  The caps 252M, 252K, 252C, and 252Y are provided with a pressure / suction mechanism (not shown) so that the inside of the nozzle can be pressurized and suctioned.

  Further, the caps 252M, 252K, 252C, 252Y are provided with a cleaning liquid supply mechanism (not shown) so that the cleaning liquid can be supplied to the inside.

  A waste liquid tray 254 is disposed below the caps 252M, 252K, 252C, 252Y. The cleaning liquid supplied to the caps 252M, 252K, 252C, 252Y is discarded in the waste liquid tray 254 and is recovered in the waste liquid tank 258 via the waste liquid recovery pipe 256.

  A nozzle surface cleaning device 260 for cleaning the nozzle surfaces 72AM, 72AK, 72AC, 72AY of the inkjet heads 72M, 72K, 72C, 72Y is provided between the image recording position and the maintenance position. Each of the inkjet heads 72M, 72K, 72C, 72Y is moved by the nozzle surface cleaning device 260 in the process of moving from the maintenance position to the image recording position or in the process of moving from the image recording position to the maintenance position. 72AC, 72AY are cleaned.

  As illustrated in FIG. 10, the nozzle surface cleaning device 260 includes a cleaning liquid applying device (cleaning liquid ejecting unit) 262 and a nozzle surface wiping device 264.

  The cleaning liquid applying device 262 applies a cleaning liquid to the nozzle surfaces 72AM, 72AK, 72AC, 72AY of the inkjet heads 72M, 72K, 72C, 72Y that move from the image recording position toward the maintenance position.

  The nozzle surface wiping device 264 presses and contacts the wiping web against the nozzle surfaces 72AM, 72AK, 72AC, 72AY of the inkjet heads 72M, 72K, 72C, 72Y to which the cleaning liquid is applied, so that the nozzle surfaces 72AM, 72AK, 72AC, Wipe 72AY.

  The cleaning liquid applying device 262 and the nozzle surface wiping device 264 are arranged on the moving path of the head support frame 240. At this time, the nozzle surface wiping device 264 is disposed on the maintenance position side with respect to the cleaning liquid applying device 262. Thereby, when each inkjet head 72M, 72K, 72C, 72Y is moved from the image recording position to the maintenance position, the nozzle surfaces 72AM, 72AK, 72AC, 72AY can be wiped with the wiping web after the cleaning liquid is applied.

  As shown in FIG. 10, the nozzle surface wiping device 264 wipes along the longitudinal direction of the inkjet head 72. Since the absorbing member 102 is provided between the head modules 72-i in the wiping direction by wiping along the longitudinal direction of the ink jet head 72, the cleaning member and excess ink are wiped by the nozzle surface wiping device while being absorbed by the absorbing member. It can be absorbed efficiently.

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device, 12 ... Paper feed part, 14 ... Processing liquid provision part, 16 ... Drawing part, 18 ... Drying part, 20 ... Fixing part, 22 ... Discharge part, 24 ... Recording medium, 70 ... Drawing drum, 72 Inkjet head, 72A ... Nozzle surface, 72B ... Head module support member, 102 ... Absorbing member, 104 ... Side surface, 105 ... Abutting surface, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124 ... shape maintaining member, 126, 136 ... handle, 128 ... length adjusting member, 130 ... claw, 132 ... abutting part, 134 ... side part, 138 ... hole, 140 ... open part, 151 ... nozzle, 260 ... nozzle surface Cleaning device, 262 ... cleaning liquid application device, 264 ... nozzle surface wiping device

Claims (12)

A droplet discharge head in which a plurality of head modules each having a plurality of nozzles for discharging liquid are continuously connected,
A droplet discharge head comprising an absorbent member having a porous structure between the connected head modules.   The droplet discharge head according to claim 1, wherein the absorbent member is wrapped in a shape maintaining member that maintains the shape of the absorbent member.   The droplet discharge head according to claim 2, wherein the shape maintaining member is formed of a metallic or resinous material.   The droplet discharge head according to claim 2, wherein the shape maintaining member is detachably disposed between the joined head modules.   5. The droplet discharge head according to claim 2, wherein the shape maintaining member is a spacer that can determine a position of the head module by contacting the adjacent head module. 6.   The droplet discharge head according to claim 5, wherein the contact portion of the shape maintaining member that contacts the head module is a circle having a diameter that is a distance between the adjacent head modules.   7. The liquid droplet ejection head according to claim 2, further comprising an opening that opens the absorbent member to the atmosphere on a side opposite to the nozzle of the shape maintaining member.   The liquid droplet ejection head according to claim 7, wherein dry air is allowed to flow to the opening side of the shape maintaining member.   The liquid droplet ejection head according to claim 2, wherein the shape maintaining member has a handle.   The liquid droplet ejection head according to claim 1, wherein the absorbent member has a handle.   The liquid droplet ejection head according to claim 1, wherein a side surface of the head module is hydrophilic. A droplet discharge head according to any one of claims 1 to 11,
A wiping device for wiping the nozzle surface on which the nozzles are formed along the arrangement direction of the head module of the droplet discharge head;
Nozzle surface maintenance system.

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