JP2021146567A - Inkjet head, inkjet head bar and inkjet printing device - Google Patents

Abstract

To provide an inkjet head, an inkjet head bar and an inkjet printing device, which can suppress occurrence of a portion left unwiped when wiping a nozzle surface.SOLUTION: An inkjet head comprises a nozzle plate (26) having a nozzle surface (18) having a plurality of nozzle openings arranged thereon, and a protecting member (20) that supports the nozzle plate from at least one side of both sides across the nozzle plate, with respect to a first direction. The protecting member, in a state of supporting the nozzle plate, comprises a first surface (38) positioned to protrude to outside of the nozzle plate more than the nozzle surface and a second surface (39), an inclined surface from the first surface toward the nozzle plate, whose end at the nozzle plate side is positioned closer to inside of the nozzle plate than the nozzle surface.SELECTED DRAWING: Figure 5

Description

The present invention relates to an inkjet head, an inkjet head bar, and an inkjet printing apparatus.

In the inkjet head, deterioration of ejection performance such as ink clogging in the nozzle, abnormality in the ejection direction, and abnormality in the ink ejection amount may occur. The inkjet head is regularly maintained for the purpose of suppressing deterioration of ejection performance. In addition, the inkjet head is also maintained when a deterioration in ejection performance is detected.

An example of maintenance of an inkjet head is a nozzle surface wiping process. As an example of the wiping process, there is an embodiment in which a wiping member such as a wiping web and a wiper is brought into contact with the nozzle surface, a constant pressure is applied to the wiping member, and the inkjet head and the wiping member are relatively moved.

Patent Document 1 describes an inkjet head having a structure in which a cover is joined to a nozzle plate. In the inkjet head described in the document, a cover is used to protect the nozzle surface from contact with a recording medium.

12 and 13 of the same document show a structural example of the cover that solves the problem that ink is trapped in the step between the nozzle surface and the cover when the nozzle surface is wiped. FIG. 12 shows an embodiment in which the steps have a stepped structure. FIG. 13 shows a mode in which the step is an inclined surface.

JP-A-2019-155839

However, in the inkjet head described in Patent Document 1, the cover is arranged outside the area wiped by the wiper on the nozzle surface. Then, the liquid or the like adhering to the cover cannot be wiped with the wiper. If the bar cannot be wiped, there is a concern that ink or the like may adhere to the cover.

On the other hand, when the nozzle surface and the cover are wiped with a wiper having a length capable of wiping the cover, a region where the wiper does not contact is generated at the contact position and the vicinity of the contact position of the nozzle surface with the cover. Then, there is a concern that the nozzle surface may be left unwiped.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an inkjet head, an inkjet head bar, and an inkjet printing apparatus capable of suppressing the occurrence of unwiped residue when wiping the nozzle surface.

In order to achieve the above object, the following aspects of the invention are provided.

The inkjet head according to the present disclosure includes a nozzle plate having a nozzle surface on which a plurality of nozzle openings are arranged, and a protective member that supports the nozzle plate from at least one of both sides sandwiching the nozzle plate in the first direction. The protective members are a first surface that protrudes to the outside of the nozzle plate from the nozzle surface in a state of supporting the nozzle plate, and an inclined surface that extends from the first surface to the nozzle plate, and is on the side of the nozzle plate. An inkjet head including a second surface whose end is located on the inner side of the nozzle plate with respect to the nozzle surface.

According to the inkjet head according to the present disclosure, the protective member that supports the nozzle surface has a second surface in which the end on the side of the nozzle plate is located inside the nozzle plate with respect to the nozzle surface. As a result, when the first surface and the nozzle surface of the protective member are wiped together, the wiping member can come into contact with the edge of the nozzle surface, and it is possible to suppress the occurrence of unwiped residue when wiping the nozzle surface. ..

As the nozzle plate, an embodiment in which a through hole serving as a nozzle opening is formed may be applied. As the nozzle plate, an embodiment in which a nozzle opening and a flow path communicating with the nozzle opening are formed may be applied.

In the inkjet head according to another aspect, the protective member includes a first member having a first surface and a second member having a second surface, and the first member and the second member are integrally formed. ..

According to such an embodiment, a protective member can be produced by applying integral molding of a resin or the like.

In the inkjet head according to another aspect, the protective member includes a first member having a first surface and a second member having a second surface, which is different from the first member.

According to such an aspect, the protective member can be generated by adding the second member having the second surface to the structure constructed by using the first member having the first surface.

When the specifications of the inkjet head are changed, such as when the structure of the components of the inkjet head is changed, the protective member before the specification change is a structure composed of the first member having the first surface. A second member having a surface can be added to generate a protective member after the specification change. According to such an aspect, the change cost in changing the specifications of the inkjet head can be suppressed.

In the inkjet head according to another aspect, a resin material is applied to the second member.

In such an embodiment, a curable adhesive containing resin particles can be applied as the resin material.

In the inkjet head according to another aspect, the plane including the second surface includes a surface in the nozzle plate that is orthogonal to the first direction and is orthogonal to the second direction that is parallel to the nozzle surface and is orthogonal to the nozzle surface. It intersects a plane at an angle of more than 0 degrees and less than 90 degrees.

According to such an aspect, when the nozzle surface and the first surface are wiped together by using the wiping member, the wiping member can come into contact with the end of the nozzle surface supported by the protective member.

In the inkjet head according to another aspect, the distance between the nozzle surface and the side end of the nozzle plate on the second surface is less than the distance between the nozzle surface and the first surface in the thickness direction of the nozzle plate.

According to such an aspect, it is possible to suppress the ingress of ink or the like between the nozzle surface and the end of the second surface on the side of the nozzle surface.

In the inkjet head according to another aspect, the distance between the nozzle surface and the end on the side of the nozzle plate on the second surface is equal to or greater than the distance between the nozzle surface and the first surface in the thickness direction of the nozzle plate.

According to such an aspect, the wiping member for wiping the nozzle can easily enter between the nozzle surface and the end on the side of the nozzle surface of the second surface, and a higher effect of suppressing unwiped residue on the nozzle surface can be obtained.

The inkjet head bar according to the present disclosure is an inkjet head bar having a structure in which a plurality of inkjet heads are arranged in a second direction orthogonal to the first direction, and the inkjet head is a nozzle in which a plurality of nozzles are arranged. A nozzle plate having a surface and a protective member that supports the nozzle plate from at least one side of both sides of the nozzle plate in the first direction are provided, and the protective member is provided from the nozzle surface in a state of supporting the nozzle plate. Is also the first surface that protrudes to the outside of the nozzle plate and the inclined surface from the first surface toward the nozzle plate, and the end on the side of the nozzle plate is the position on the inside side of the nozzle plate with respect to the nozzle surface. An inkjet headbar with a second surface.

According to the inkjet head bar according to the present disclosure, in an inkjet head bar having a structure in which a plurality of inkjet heads are arranged in a second direction, a nozzle surface when the first surface and the nozzle surface of the protective member are wiped together. It is possible to suppress the unwiped residue.

The inkjet printing apparatus according to the present disclosure is an inkjet printing apparatus including one or more inkjet heads, wherein the inkjet head includes a nozzle plate having a nozzle surface on which a plurality of nozzles are arranged and a nozzle plate in the first direction. A first surface is provided with a protective member that supports the nozzle plate from at least one side on both sides of the nozzle plate, and the protective member is positioned so as to protrude to the outside of the nozzle plate from the nozzle surface in a state of supporting the nozzle plate. This is an inkjet printing device including an inclined surface from the first surface toward the nozzle plate, and a second surface in which the end on the side of the nozzle plate is located on the inner side of the nozzle plate with respect to the nozzle surface.

The inkjet printing apparatus according to another aspect includes an inkjet head bar having a structure in which a plurality of inkjet heads are arranged in a second direction orthogonal to the first direction.

According to such an aspect, in an inkjet head bar having a structure in which a plurality of inkjet heads are arranged in a second direction, it is possible to suppress unwiped residue when wiping the nozzle surface.

The inkjet printing device according to another aspect includes a wiping device that wipes the nozzle surface and a head moving device that relatively moves the inkjet head and the wiping device in the second direction, and the wiping device wipes the nozzle surface. A wiping member and a pressure applying device for applying pressure toward the nozzle surface to the wiping member are provided.

According to this aspect, in wiping the nozzle surface using the wiping device that moves the inkjet head and the wiping device relative to each other, it is possible to suppress the unwiped residue of the nozzle surface.

In the inkjet printing apparatus according to another aspect, the wiping member is a sheet member traveling in the second direction, and the pressure applying device is a support roller that supports the sheet member from the opposite side of the nozzle surface and a support roller. A pressure generator for generating the applied pressure is provided.

According to such an aspect, it is possible to suppress the unwiped residue of the nozzle surface when the sheet member is run to wipe the nozzle surface.

In an inkjet printing apparatus according to another aspect, a plurality of inkjet heads corresponding to each of a plurality of ink types and a medium transport in which a medium to be printed by using the inkjet head and the inkjet head are relative to each other in the first direction. A device and a plurality of inkjet heads are arranged along the first direction.

According to this aspect, in an inkjet printing apparatus that prints using a plurality of inks, it is possible to suppress unwiped residue when wiping the nozzle surface of the inkjet head.

According to the present invention, the protective member that supports the nozzle surface has a second surface in which the end on the side of the nozzle plate is located inside the nozzle plate with respect to the nozzle surface. As a result, when the first surface and the nozzle surface of the protective member are wiped together, the wiping member can come into contact with the edge of the nozzle surface, and it is possible to suppress the occurrence of unwiped residue when wiping the nozzle surface. ..

FIG. 1 is a perspective view of an inkjet head bar including the inkjet head according to the first embodiment. FIG. 2 is a partially enlarged view of the nozzle surface of the inkjet head bar shown in FIG. FIG. 3 is a perspective view of the inkjet head shown in FIG. 1 and is a view including a partial cross-sectional view. FIG. 4 is a schematic view of the nozzle surface of the inkjet head bar shown in FIG. FIG. 5 is a cross-sectional view taken along the 5-5 cross-sectional line shown in FIG. FIG. 6 is a schematic view of the nozzle surface wiping process in the inkjet head bar. FIG. 7 is a schematic view showing a configuration example of a wiping device applied to the wiping process shown in FIG. FIG. 8 is a cross-sectional view of the inkjet head according to the first comparative example. FIG. 9 is a cross-sectional view of the inkjet head according to the second comparative example. FIG. 10 is a cross-sectional view of the inkjet head according to the second embodiment. FIG. 11 is an explanatory diagram of compatibility of the inkjet head. FIG. 12 is an overall configuration diagram of the inkjet printing apparatus. FIG. 13 is a configuration diagram of a maintenance unit provided in the inkjet printing apparatus shown in FIG. FIG. 14 is a table showing a composition example of the nozzle cleaning liquid. FIG. 15 is a table showing a composition example of the moisturizer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification, the same components are designated by the same reference numerals, and duplicate description will be omitted as appropriate.

[First Embodiment]
[Overall configuration of inkjet headbar]
FIG. 1 is a perspective view of an inkjet head bar including the inkjet head according to the first embodiment. The inkjet head bar 10 is a liquid ejection head applied to an inkjet printing apparatus, and ejects ink droplets toward a medium to be printed.

The inkjet head bar 10 has a structure in which a plurality of inkjet heads 12 are connected along the longitudinal direction. The plurality of inkjet heads 12 are integrally supported by the support frame 14. The inkjet head bar 10 shown in the embodiment is an example of an inkjet head bar having a structure in which a plurality of inkjet heads are arranged.

Two flexible substrates 16 are connected to each inkjet head 12. The flexible substrate 16 is formed with electrical wiring for transmitting a drive voltage supplied to a discharge element provided in the inkjet head 12.

The discharge element includes a nozzle opening, a flow path communicating with the nozzle opening, and an energy generating element. The energy generating element applies a ejection pressure to the ink ejected from the nozzle opening. Piezoelectric elements may be applied as the energy generating element. The inkjet head 12 may apply a piezoelectric method in which ink droplets are ejected from a nozzle opening according to the deflection deformation of the piezoelectric element.

A heating element may be applied as the energy generating element. The inkjet head 12 may apply a thermal method of ejecting ink droplets from a nozzle opening by utilizing the phenomenon of ink film boiling. The discharge element, nozzle opening, flow path, and energy generation element are not shown.

The inkjet head 12 has a plurality of nozzle openings formed on the nozzle surface 18. A liquid-repellent film having liquid-repellent property against ink is formed on the nozzle surface. Any arrangement such as a matrix arrangement may be applied to the arrangement of the plurality of nozzle openings.

The nozzle plate having the nozzle surface is supported from both sides of the inkjet head bar 10 in the lateral direction by using the wing cover 20. The inkjet head 12 may apply a mode in which the nozzle plate is supported from only one side in the lateral direction.

In FIG. 1, the nozzle opening and the nozzle plate are not shown. The nozzle opening is illustrated in FIG. 4 using reference numeral 40. The nozzle plate is illustrated in FIG. 3 using reference numeral 26. In the following description, the longitudinal direction of the inkjet head bar 10 is synonymous with the longitudinal direction of the inkjet head 12. Similarly, the lateral direction of the inkjet head bar 10 is synonymous with the lateral direction of the inkjet head 12.

The lateral direction of the inkjet head bar 10 shown in the embodiment is an example of the first direction. The longitudinal direction of the inkjet head bar 10 shown in the embodiment is an example of a second direction orthogonal to the first direction.

The wing cover 20 shown in the embodiment is an example of a protective member that supports the nozzle plate from at least one of both sides sandwiching the nozzle plate in the first direction. The first surface 38 shown in the embodiment is an example of the first surface at a position where the nozzle plate is supported and the position is such that the nozzle surface protrudes to the outside of the nozzle plate.

Here, the term orthogonal can include substantially orthogonal, which is non-orthogonal but can have the same effect as orthogonal.

FIG. 2 is a partially enlarged view of the nozzle surface of the inkjet head bar shown in FIG. The nozzle surface 18 of the inkjet head bar 10 in the following description is synonymous with the nozzle surface 18 of the inkjet head 12.

The nozzle surface 18 of the inkjet head 12 has a parallel quadrilateral shape. Dummy plates 22 are attached to both ends of the support frame 14. The nozzle surface 18 of the inkjet head 12 has a rectangular shape as a whole when combined with the surface 22A of the dummy plate 22.

A plurality of nozzle openings are formed on the nozzle surface 18 of the inkjet head 12. Note that FIG. 2 does not show the nozzle openings individually, but illustrates the nozzle opening group 24 composed of a plurality of nozzle openings.

[Structural example of inkjet head]
FIG. 3 is a perspective view of the inkjet head shown in FIG. 1 and is a view including a partial cross-sectional view. The inkjet head 12 has an ink supply unit including an ink supply chamber 28, an ink circulation chamber 30, and the like on the upper surface side in FIG. 4 opposite to the nozzle surface 18 of the nozzle plate 26.

The ink supply chamber 28 is connected to the ink tank via the supply-side individual flow path 32. The ink circulation chamber 30 is connected to the collection tank via the individual flow path 34 on the collection side. The illustration of the ink tank and the recovery tank will be omitted.

The nozzle opening formed in the nozzle plate 26 communicates with the flow path formed in the flow path structure 36. The flow path structure 36 forms a flow path and an energy generating element that communicate with the ink supply chamber 28 and the ink circulation chamber 30. A silicon substrate can be applied as the material of the nozzle plate 26 and the flow path structure 36. The detailed illustration of the flow path structure 36 will be omitted.

The nozzle plate 26 may have a structure integrated with the flow path structure 36. For example, photolithography can be applied to a silicon substrate to integrally generate the nozzle plate 26 and the flow path structure 36.

The inkjet head 12 has a structure in which the first surface 38 of the wing cover 20 protrudes from the nozzle surface 18. The wing cover 20 has a second surface that is inclined from the first surface 38 toward the nozzle plate 26. The side end of the nozzle plate 26 on the second surface is located on the inner side of the nozzle plate 26 with respect to the nozzle surface 18. In FIG. 3, the illustration on the second surface is omitted. The second surface of the wing cover 20 is designated by reference numeral 39 and is shown in FIG.

FIG. 4 is a schematic view of the nozzle surface of the inkjet head bar shown in FIG. FIG. 5 is a cross-sectional view taken along the 5-5 cross-sectional line shown in FIG. In FIG. 5, a part of the wing cover 20 and the nozzle plate 26 is enlarged and shown. Further, in FIG. 5, the illustration of the nozzle opening 40 shown in FIG. 4 is omitted, and the nozzle arrangement area 41 in which the nozzle opening 40 is arranged is shown.

The wing cover 20 shown in FIGS. 4 and 5 includes a first surface 38 and a second surface 39. The first surface 38 is positioned so as to protrude from the nozzle surface 18. The first surface 38 is parallel to the nozzle surface 18. It should be noted that the parallelism referred to here is non-parallel, but may include substantially parallel that can obtain the same action and effect as parallel.

The second surface 39 is an inclined surface from the first surface 38 toward the nozzle surface 18, and the end 39A of the second surface 39 on the nozzle surface 18 side is located closer to the inside of the nozzle plate 26 than the nozzle surface 18. do.

Further, the plane including the second surface 39 is 0 degrees with the plane including the surface of the nozzle plate 26 that is orthogonal to the lateral direction of the inkjet head 12 and the longitudinal direction of the inkjet head 12 and is orthogonal to the nozzle surface 18. It is an angle exceeding, and intersects at an angle of less than 90 degrees. The angle formed by both planes is preferably 45 degrees or less, and more preferably 30 degrees or less.

The distance from the nozzle surface 18 in the thickness direction of the nozzle plate 26 to the end 39A on the side of the nozzle surface 18 of the second surface 39 can be defined according to the distance from the first surface 38 to the nozzle surface 18 in the same direction.

The distance from the nozzle surface 18 in the same direction to the end 39A on the side of the nozzle surface 18 of the second surface 39 may be less than the distance from the first surface 38 to the nozzle surface 18 in the same direction. As a result, it is possible to suppress the entry of ink or the like between the nozzle plate 26 and the second surface 39.

For example, when the distance from the first surface 38 to the nozzle surface 18 in the same direction is 100 micrometers, the distance from the nozzle surface 18 to the end 39A on the nozzle surface 18 side of the second surface 39 in the same direction is 10 micrometers. As mentioned above, it may be 50 micrometers or less.

Further, the distance from the nozzle surface 18 in the same direction to the end 39A on the side of the nozzle surface 18 of the second surface 39 may be greater than or equal to the distance from the first surface 38 to the nozzle surface 18 in the same direction. As a result, it is possible to suppress the unwiped residue of the nozzle surface when the nozzle surface 18 and the first surface 38 are wiped together.

For example, when the distance from the first surface 38 to the nozzle surface 18 in the same direction is 100 micrometers, the distance from the nozzle surface 18 to the end 39A on the nozzle surface 18 side of the second surface 39 in the same direction is 100 micrometers. As mentioned above, it may be 500 micrometers or less.

The first surface 38 and the second surface 39 provided on the wing cover 20 can integrally form the first surface 38 and the second surface 39 by applying integral molding of a synthetic resin. An example of a synthetic resin is plastic.

Although FIG. 5 illustrates an embodiment in which the second surface 39 has a constant inclination, the second surface 39 may include two or more inclined surfaces that change continuously. Further, the second surface 39 is not limited to a flat surface, and a spherical surface including at least one of a concave surface and a convex surface can be applied. The same applies to the first surface 38.

[Nozzle surface wiping process]
FIG. 6 is a schematic view of the nozzle surface wiping process in the inkjet head bar. The inkjet head bar 10 periodically wipes the nozzle surface 18 in order to maintain the ejection performance of the ejection element.

In FIG. 6, as an example of the nozzle surface wiping process, the inkjet head bar 10 is moved in the head bar moving direction parallel to the longitudinal direction of the inkjet head bar 10, and the wiping web 100 is traveled in the web traveling direction. An embodiment of the mode is illustrated.

The wiping web 100 has a total width exceeding the total length of the inkjet head bar 10 in the lateral direction of the inkjet head bar 10. In other words, the wiping web 100 is configured to be able to wipe the entire width of the nozzle surface 18 and the entire width of the wing cover 20 at once. The width of the wiping web 100 is the length of the wiping web 100 in the web width direction orthogonal to the web traveling direction.

FIG. 6 shows an aspect in which the web traveling direction is parallel to the longitudinal direction of the inkjet head bar 10, but the web traveling direction is an angle exceeding 0 degrees with respect to the longitudinal direction of the inkjet head bar 10, and is 90. It may intersect in a range of angles less than degrees.

FIG. 7 is a schematic view showing a configuration example of a wiping device applied to the wiping process shown in FIG. The wiping device 102 shown in the figure includes a unwinding roll 104 around which an unused wiping web 100 is wound, and a winding roll 106 around which a used wiping web 100 is wound.

The wiping web 100 pulled out from the unwinding roll 104 is wound up on the winding roll 106 via the tension roller 108. The rotating shaft of the take-up roll 106 is connected to the rotating shaft of the motor via a transmission mechanism. When the motor is rotated in the specified rotation direction, the wiping web 100 travels from the unwinding roll 104 toward the winding roll 106. The transmission mechanism and the motor are not shown.

The tension roller 108 has a cylindrical shape. An elastic member such as rubber can be applied to the tension roller 108. The tension roller 108 presses the traveling wiping web 100 against the nozzle surface 18.

That is, the wiping device 102 includes a tension generator 110, and the tension generator 110 applies a specified tension to the tension roller 108. The arrow line with the reference numeral T indicates the direction of tension. The prescribed tension may apply 20 kilopascals. The specified tension may be any value between 10 kilopascals and 30 kilopascals.

In the inkjet head 12 shown in FIG. 5, a step is formed between the nozzle surface 18 and the first surface 38 of the wing cover 20, but the wiping web is dependent on the elasticity of the tension roller 108 and the flexibility of the wiping web 100. 100 follows a step between the nozzle surface 18 and the first surface 38 of the wing cover 20.

That is, the wiping web 100 supported by the tension roller 108 that elastically deforms following the inclination of the second surface 39 is inside the nozzle plate 26 rather than the nozzle surface 18 on the side of the nozzle surface 18 of the second surface 39. Can get into the side. Then, in the lateral direction of the inkjet head 12, the wiping web 100 can come into contact with the nozzle surface 18 from one end to the other end and wipe from one end to the other end of the nozzle surface 18.

The wiping device 102 includes a cleaning liquid supply device 112 that supplies the nozzle cleaning liquid to the unused wiping web 100. The cleaning liquid supply device 112 includes a cleaning liquid nozzle 114 that supplies the cleaning liquid to the wiping web 100. The cleaning liquid nozzle 114 is connected to the cleaning liquid tank via the cleaning liquid flow path 116. Further, the cleaning liquid flow path 116 includes a pump. The cleaning liquid tank and pump are not shown.

The wiping device 102 runs the wiping web 100 in the direction opposite to the moving direction of the inkjet head bar 10 at the contact position where the wiping web 100 contacts the nozzle surface 18, and brings the wiping web 100 into contact with the nozzle surface 18 to bring the wiping web 100 into contact with the nozzle surface 18. Carry out 18 wiping.

As a result, the deposit 120 adhering to the nozzle surface 18 is wiped off using the wiping web 100. Adhesion 122 indicates deposits adhering to the used wiping web 100.

The wiping web 100 shown in the embodiment is an example of a wiping member and an example of a sheet member. The tension roller 108 shown in the embodiment is an example of a support roller. The tension generator 110 shown in the embodiment is an example of the pressure generator. Each of the tension roller 108 and the tension generator 110 shown in the embodiment is an example of a component of the pressure applying device.

[Action and effect of the first embodiment]
The inkjet head 12 and the inkjet head bar 10 according to the first embodiment can obtain the following effects.

[1]
The wing cover 20 that supports the nozzle plate 26 includes a first surface 38 that protrudes from the nozzle surface 18. The wing cover 20 includes a second surface 39 which is an inclined surface from the first surface 38 toward the nozzle plate 26. The end of the second surface 39 on the nozzle plate 26 side is located on the inner side of the nozzle plate 26 with respect to the nozzle surface 18.

As a result, when the nozzle surface 18 and the wing cover 20 are wiped together, the wiping web 100 can be brought into contact with the nozzle surface 18 from one end to the other end in the lateral direction of the inkjet head, and the nozzle surface can be wiped. It is possible to suppress the unwiped portion of 18.

FIG. 8 is a cross-sectional view of the inkjet head according to the first comparative example. The inkjet head 1 shown in the figure has a step between the first surface 3 of the wing cover 2 and the nozzle surface 4. The web 5 pressed against the nozzle surface 4 by the tension roller does not follow the step between the first surface 3 of the wing cover 2 and the nozzle surface 4, and the end portion of the nozzle surface 4 on the wing cover 2 side. Do not contact with. Then, the nozzle surface 4 is left unwiped.

FIG. 9 is a cross-sectional view of the inkjet head according to the second comparative example. The inkjet head 1A shown in the figure includes a second surface 7A that is inclined from the first surface 3A of the wing cover 2A toward the nozzle surface 4.

The end of the second surface 7A on the nozzle surface 4 side is at the same position as the nozzle surface 4. Even in such a case, the web 5 does not follow the second surface 7A and does not come into contact with the end portion of the nozzle surface 4 on the wing cover 2A side. Then, the nozzle surface 4 is left unwiped.

On the other hand, in the inkjet head 12 shown in FIG. 5, the wiping web 100 follows the first surface 38, the second surface 39, and the nozzle surface 18 of the wing cover 20, and the unwiped residue of the nozzle surface 18 can be suppressed.

[2]
The wing cover 20 is produced by applying integral molding of a synthetic resin. As a result, the wing cover 20 having the first surface 38 and the second surface 39 can be generated with high accuracy.

[Second Embodiment]
[Inkjet head configuration example]
FIG. 10 is a cross-sectional view of the inkjet head according to the second embodiment. The wing cover 220 provided on the inkjet head 212 shown in the figure is composed of a first member 251 including a first surface 250 and a second member 253 including a second surface 252.

The nozzle plate 226 provided on the inkjet head 212 includes a nozzle surface 218 and a nozzle arrangement area 241 similar to the nozzle plate 26 shown in FIG. 5 and the like.

Similar to the wing cover 20 shown in FIG. 5 and the like, a synthetic resin such as plastic can be applied to the first member 251. The second member 253 may be made of a material different from the synthetic resin applied to the first member 251.

Examples of the material applied to the second member 253 include a resin material that fills the gap between the first member 251 and the nozzle surface 218. An example of a resin material is a curable adhesive containing resin particles.

[Compatibility with modified specifications]
FIG. 11 is an explanatory diagram of compatibility of the inkjet head. Consider a case where the specifications of the components of the inkjet head 1B are changed in the inkjet head bar in which the inkjet heads 1B shown on the right side of FIG. 11 are connected.

The specification change of the inkjet head 1B is to reduce the size of the nozzle plate 8B in the lateral direction. The alternate long and short dash line shown on the inkjet head 1B indicates the boundary between the wing cover 2B and the nozzle plate 8B after the specification change.

The inkjet head bar to which the inkjet heads 1B are connected can be replaced for each inkjet head 1B when any of the inkjet heads 1B fails.

When changing the specifications of the inkjet head 1B, it is necessary to consider compatibility before and after the specification change. When the nozzle plate 8B is miniaturized and the first surface 3B of the wing cover 2B is expanded toward the nozzle plate 8B, a sharp step as shown in FIG. 8 occurs between the first surface 3B and the nozzle surface 4B. ..

When the wiping device 102 shown in FIG. 7 is designed according to the inkjet head 1B before the specification change, when the nozzle surface 4B of the inkjet head 1B after the specification change is wiped, the nozzle surface 4B may be left unwiped. ..

It is possible to change the wiping device 102 in order to suppress the unwiped residue of the nozzle surface 4B, but it is necessary to consider the sharing of the inkjet head 1B before and after the specification change. The change of the wiping device 102 has a demerit that the existing device is changed, the device needs to be modified, and the business of the user is also affected. Considering such circumstances, it is desired that the inkjet head 1B be used.

The inkjet head 12 shown on the right side of FIG. 11 includes a nozzle plate 26 corresponding to the nozzle plate 8B after the specification change shown on the left side of the figure, and in wiping the nozzle surface 18 using the wiping device 102 shown in FIG. , No nozzle surface 18 is left unwiped.

In particular, when the inkjet head 212 according to the second embodiment is used, the second member 253 shown in FIG. 11 is provided with respect to the gap between the wing cover 2B and the nozzle plate 8B with respect to the wing cover 2B before the specification change. Just add it.

[Action and effect of the second embodiment]
The inkjet head 212 according to the second embodiment can obtain the following effects.

[1]
The wing cover 220 includes a first member 251 including a first surface 250 and a second member 253 including a second surface 252. A material different from that of the first member 251 is applied to the second member 253. This gives more choice of materials to be applied to the wing cover 220.

[2]
Even when the specifications of the nozzle plate 8B shown in FIG. 11 are changed, it is possible to add the second member 253 to the wing cover 2B before the specification change.

[Configuration example of inkjet printing device]
〔overall structure〕
FIG. 12 is an overall configuration diagram of the inkjet printing apparatus. The inkjet printing apparatus 300 shown in the figure includes a printing drum 304 and an inkjet head bar 306. The inkjet printing apparatus 300 supports the medium 302 delivered from the paper feed drum 303 on the outer peripheral surface of the printing drum 304 and conveys the medium 302.

The inkjet printing apparatus 300 ejects ink from the inkjet head bar 306 to the medium 302, and prints a color image on the printing surface of the medium 302. The medium 302 on which the color image is printed is delivered from the printing drum 304 to the paper ejection drum 307.

The printing drum 304 is rotatably supported on the rotating shaft 308. A motor is connected to the rotating shaft 308 of the printing drum 304 via a transmission mechanism. The print drum 304 rotates according to the rotation of the motor. The transmission mechanism and the motor are not shown.

The printing drum 304 includes two grippers 310. The two grippers 310 are arranged so as to be separated from each other by a distance of half of the total peripheral length of the printing drum 304 in the circumferential direction of the outer peripheral surface of the printing drum 304.

The gripper 310 includes a plurality of gripping claws arranged along the width direction of the medium. The plurality of gripping claws grip the tip of the medium 302. The medium width direction is a direction orthogonal to the transport direction of the medium 302 in the printing drum 304. The medium width direction is parallel to the direction of the rotation axis 308 of the printing drum 304. It should be noted that the illustration of the plurality of gripping claws is omitted.

The printing drum 304 includes a suction mechanism. As a configuration example of the suction mechanism, an embodiment including a suction hole arranged on the outer peripheral surface of the printing drum 304, a flow path connected to the suction hole, and a pump connected to the flow path can be mentioned. As the method of the adsorption mechanism, electrostatic adsorption or the like can be applied.

The tip of the medium 302 is gripped by the gripper 310, and the back surface of the printing surface is sucked by the suction mechanism, and the medium 302 is sucked and supported by the outer peripheral surface of the printing drum 304. The medium 302 attracted and supported by the outer peripheral surface of the printing drum 304 is conveyed along the outer peripheral surface of the printing drum 304 according to the rotation of the printing drum 304.

The inkjet printing apparatus 300 includes an inkjet head bar 306C, an inkjet head bar 306M, an inkjet head bar 306Y, and an inkjet head bar 306K. The inkjet head bar 306C, the inkjet head bar 306M, the inkjet head bar 306Y, and the inkjet head bar 306K are integrally supported by the head support member 309.

The inkjet head bar 306 is a general term for the inkjet head bar 306C, the inkjet head bar 306M, the inkjet head bar 306Y, and the inkjet head bar 306K. As the inkjet head bar 306 shown in FIG. 12, the inkjet head 12 shown in FIG. 4 and the inkjet head 212 shown in FIG. 10 are applied.

The inkjet head bar 306 is a line head corresponding to the entire width of the medium 302. The inkjet printing apparatus 300 can perform single-pass printing in which the inkjet head bar 306 and the medium 302 are relatively scanned once to print on the entire surface of the medium 302.

The inkjet head bar 306C ejects cyan ink. The inkjet head bar 306M ejects magenta ink. The inkjet head bar 306Y ejects yellow ink. Inkjet head bar 306K ejects black ink,
The inkjet headbars 306 are arranged at equal intervals along the outer peripheral surface of the printing drum 304 in a state where the nozzle surface is inclined with respect to the horizontal plane 301 and the nozzle surface is parallel to the outer peripheral surface of the printing drum 304. Will be done. Further, the inkjet head bar 306 is arranged at a position where the distance between the nozzle surface and the outer peripheral surface of the printing drum 304 is equal.

FIG. 12 illustrates a drum transport method for transporting the medium 302 using the printing drum 304, but various transport methods for the medium 302 such as a belt transport method for supporting and transporting the medium 302 using a transport belt can be used. Applicable.

The inkjet printing apparatus 300 shown in the embodiment is an example of an inkjet printing apparatus including one or more inkjet heads. The printing drum 304 shown in the embodiment is an example of a medium transporting device that transports the medium and the inkjet head relative to each other.

[Structure example of maintenance unit]
FIG. 13 is a configuration diagram of a maintenance device provided in the inkjet printing device shown in FIG. The maintenance device 350 includes a head bar moving device 352 for moving the inkjet head bar 306, a wiping device 354, and a capping device 356.

The head bar moving device 352 moves the inkjet head bar 306C, the inkjet head bar 306M, the inkjet head bar 306Y, and the inkjet head bar 306K shown in FIG. 12 between the drawing position and the capping position.

The drawing position is a position where the inkjet head bar 306 prints on the medium 302. The capping position is a position where the inkjet head bar 306 is capped using the capping device 356.

FIG. 13 shows the inkjet head bar 306 at the drawing position using a solid line. In addition, the inkjet head bar 306 at the capping position is illustrated using the alternate long and short dash line.

The head bar moving device 352 includes a linear guide 360 and a carriage 362.

The carriage 362 connected to the linear guide 360 is connected to the inkjet head bar 306. The linear guide 360 is connected to the motor via a transmission mechanism. The carriage 362 moves along the linear guide 360 in response to the rotation of the motor. The transmission mechanism and the motor are not shown. The head bar moving device 352 shown in the embodiment is an example of a head moving device that relatively moves the inkjet head and the wiping device.

The wiping device 354 wipes the nozzle surface of the inkjet head bar 306. As the wiping device 354, the wiping device 102 shown in FIG. 7 is applied. The wiping device 354 is arranged between the drawing position and the capping position.

The wiping device 354 includes an elevating mechanism 364 that raises and lowers the wiping device 354. The elevating mechanism 364 moves the wiping device 354 vertically upward and vertically downward. The wiping device 354 may move between the wiping position and the standby position. FIG. 13 shows a wiping device 354 at the wiping position.

The capping device 356 includes a cap 370, a cap flow path 372, a pump 374, and a recovery tank 376. The cap 370 is attached to the nozzle surface of the inkjet head bar 306. The cap 370 suppresses the drying of the nozzle surface of the inkjet head bar 306 while the inkjet head bar 306 is inactive. The cap 370 includes a moisturizer pool in which the moisturizer is stored.

Further, the cap 370 functions as a container for receiving the ink discharged from the inkjet head bar 306 when the purging process of the inkjet head bar 306 is performed.

The cap 370 is connected to the cap flow path 372. A pump 374 is attached to the cap flow path 372. The cap flow path 372 is connected to the recovery tank 376. The pump 374 generates a suction pressure acting on the inkjet head bar 306 when sucking ink from the inkjet head bar 306. The recovery tank 376 is a tank for storing the ink recovered from the cap 370.

The configuration of the maintenance device 350 shown in FIG. 13 is an example, and components can be added, deleted, and changed according to the configurations of the inkjet printing device 300 and the inkjet head bar 306.

[Specific example of nozzle cleaning liquid]
FIG. 14 is a table showing a composition example of the nozzle cleaning liquid. The figure shows a composition example of two types of nozzle cleaning liquids. The nozzle cleaning liquid is applied to the wiping device 102 shown in FIG. 7 and the wiping device 354 shown in FIG. The nozzle cleaning solution contains water, a solvent, a pH regulator, a surfactant, an additive and a defoaming agent.

In addition, TRIS represents trishydroxymethylaminomethane. Pionin D-1706-N is a product name of a surfactant manufactured by Takemoto Oil & Fats Co., Ltd. Snowtex XS (20%) is the product name of colloidal silica manufactured by Nissan Chemical Industries, Ltd. BYK-024 is a product name of an antifoaming agent manufactured by Big Chemy Japan Co., Ltd.

[Specific example of moisturizer]
FIG. 15 is a table showing a composition example of the moisturizer. The figure shows an example of the composition of two types of moisturizers. The moisturizing liquid is housed in the cap 370 shown in FIG. 13 and applied to moisturize the nozzle surface of the inkjet head bar 306. The moisturizer contains water, a surfactant, a rust inhibitor and a pH regulator.

Orphine E1010 is a product name of a surfactant manufactured by Nissin Chemical Industry Co., Ltd. Proxel GXL is a trade name of an ink preservative manufactured by Lonza Japan Co., Ltd. Kordek MLX is a product name of DuPont.

[Hardware configuration of each processing unit and control unit]
The inkjet printing apparatus 300 shown in FIG. 12 includes a processing unit that executes a program to realize various functions. Various processors can be applied to the hardware of the processing unit that executes various processes applied to the inkjet printing apparatus 300.

The processing unit may be called a processing unit. Various processors include a CPU (Central Processing Unit), a PLD (Programmable Logic Device), an ASIC (Application Specific Integrated Circuit), and the like.

The CPU is a general-purpose processor that executes a program and functions as various processing units. The PLD is a processor whose circuit configuration can be changed after manufacturing. An example of PLD is FPGA (Field Programmable Gate Array). An ASIC is a dedicated electric circuit having a circuit configuration specially designed to perform a specific process.

One processing unit may be composed of one of these various processors, or may be composed of two or more processors of the same type or different types. For example, one processing unit may be configured by using a plurality of FPGAs and the like. One processing unit may be configured by combining one or more FPGAs and one or more CPUs.

Further, a plurality of processing units may be configured by using one processor. As an example of configuring a plurality of processing units using one processor, there is a form in which one processor is configured by combining one or more CPUs and software, and one processor functions as a plurality of processing units. Such a form is represented by a computer such as a client terminal device and a server device.

As another configuration example, there is a mode in which a processor that realizes the functions of the entire system including a plurality of processing units by using one IC chip is used. Such a form is typified by a system on chip and the like. IC is an abbreviation for Integrated Circuit. In addition, system on chip may be described as SoC by using the abbreviation of System On Chip.

As described above, the various processing units are configured by using one or more of the above-mentioned various processors as a hardware structure. Further, the hardware structure of various processors is, more specifically, an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

[Terminology]
The term printing device is synonymous with terms such as a printing machine, a printer, a printing device, an image recording device, an image forming device, an image output device, and a drawing device. The image shall be interpreted in a broad sense, and includes a color image, a black-and-white image, a single-color image, a gradation image, a uniform density image, and the like.

The term printing includes the concepts of terms such as image recording, image formation, printing, drawing and printing. The term device can include the concept of a system.

The image is not limited to a photographic image, but is used as a comprehensive term including a pattern, a character, a symbol, a line drawing, a mosaic pattern, a color-coded pattern and various other patterns, and an appropriate combination thereof.

In the embodiment of the present invention described above, the constituent requirements can be appropriately changed, added, or deleted without departing from the spirit of the present invention. The present invention is not limited to the embodiments described above, and many modifications can be made by a person having ordinary knowledge in the art within the technical idea of the present invention. In addition, the embodiments, modifications, and applications may be combined as appropriate.

1 Inkjet head 1A Inkjet head 1B Inkjet head 2 Wing cover 2A Wing cover 2B Wing cover 3 First side 3A First side 3B First side 4 Nozzle surface 4B Nozzle surface 5 Web 7A Second side 8B Nozzle plate 10 Inkjet head bar 12 Inkjet head 14 Support frame 16 Flexible substrate 18 Nozzle surface 20 Wing cover 22 Dummy plate 22A Surface 24 Nozzle opening group 26 Nozzle plate 28 Inkjet plate 28 Ink circulation chamber 32 Ink circulation chamber 32 Supply side individual flow path 34 Recovery side individual flow path 36 Flow path structure Body 38 First surface 39 Second surface 39A End 40 Nozzle opening 41 Nozzle arrangement area 100 Wiping web 102 Wiping device 104 Unwinding roll 106 Winding roll 108 Tension roller 110 Tension generator 112 Cleaning liquid supply device 114 Cleaning liquid nozzle 116 Cleaning liquid flow path 120 Adhesion 122 Adhesion 212 Inkjet head 218 Inkjet head 218 Nozzle surface 220 Wing cover 226 Nozzle plate 241 Nozzle arrangement area 250 First surface 252 Second surface 253 Second member 300 Inkjet printing device 301 Horizontal plane 302 Medium 303 Feeding drum 304 Printing drum 306 Inkjet head bar 306C Inkjet head bar 306 Inkjet head bar 306Y Inkjet head bar 306K Inkjet head bar 307 Output drum 308 Rotating shaft 309 Head support member 310 Gripper 350 Maintenance device 352 Head bar moving device 354 Wiping device 356 Capping device 360 Linear guide 362 Carrying 364 Lifting mechanism 370 Cap 372 Flow path 374 Pump 376 Recovery tank

Claims (13)

A nozzle plate having a nozzle surface on which a plurality of nozzle openings are arranged, and
In the first direction, a protective member that supports the nozzle plate from at least one side on both sides of the nozzle plate, and
With
The protective member is
In a state of supporting the nozzle plate, a first surface at a position where the nozzle surface protrudes to the outside of the nozzle plate, and
A second surface which is an inclined surface from the first surface toward the nozzle plate and whose end on the side of the nozzle plate is located on the inner side of the nozzle plate with respect to the nozzle surface.
Inkjet head with. The protective member is
The first member having the first surface and
The second member having the second surface and
With
The inkjet head according to claim 1, wherein the first member and the second member are integrally formed. The protective member is
The first member having the first surface and
A second member having the second surface, which is different from the first member,
The inkjet head according to claim 1. The inkjet head according to claim 3, wherein the second member is a resin material. The plane including the second surface is a plane including a plane orthogonal to the first direction and orthogonal to the second direction orthogonal to the nozzle surface and orthogonal to the nozzle surface in the nozzle plate, and 0. The inkjet head according to any one of claims 1 to 4, which has an angle exceeding degrees and intersects at an angle of less than 90 degrees. Any of claims 1 to 5, wherein the distance between the nozzle surface and the end of the second surface on the side of the nozzle plate is less than the distance between the nozzle surface and the first surface in the thickness direction of the nozzle plate. The inkjet head described in item 1. Any of claims 1 to 5 in which the distance between the nozzle surface and the end of the second surface on the side of the nozzle plate is equal to or greater than the distance between the nozzle surface and the first surface in the thickness direction of the nozzle plate. The inkjet head described in item 1. An inkjet head bar having a structure in which a plurality of inkjet heads are arranged in a second direction orthogonal to the first direction.
The inkjet head
A nozzle plate having a nozzle surface on which a plurality of nozzles are arranged and
In the first direction, a protective member that supports the nozzle plate from at least one side on both sides of the nozzle plate.
With
The protective member is
In a state of supporting the nozzle plate, a first surface at a position where the nozzle surface protrudes to the outside of the nozzle plate, and
A second surface which is an inclined surface from the first surface toward the nozzle plate and whose end on the side of the nozzle plate is located on the inner side of the nozzle plate with respect to the nozzle surface.
Inkjet head bar with. An inkjet printing device equipped with one or more inkjet heads.
The inkjet head
A nozzle plate having a nozzle surface on which a plurality of nozzles are arranged and
In the first direction, a protective member that supports the nozzle plate from at least one side on both sides of the nozzle plate, and
With
The protective member is
In a state of supporting the nozzle plate, a first surface at a position where the nozzle surface protrudes to the outside of the nozzle plate, and
A second surface which is an inclined surface from the first surface toward the nozzle plate and whose end on the side of the nozzle plate is located on the inner side of the nozzle plate with respect to the nozzle surface.
Inkjet printing device equipped with. The inkjet printing apparatus according to claim 9, further comprising an inkjet head bar having a structure in which a plurality of the inkjet heads are arranged in a second direction orthogonal to the first direction. A wiping device that wipes the nozzle surface and
A head moving device that relatively moves the inkjet head and the wiping device in the second direction,
With
The wiping device is
A wiping member that wipes the nozzle surface and
A pressure applying device that applies pressure toward the nozzle surface to the wiping member, and
The inkjet printing apparatus according to claim 10. The wiping member is a seat member traveling in the second direction.
The pressure applying device is
A support roller that supports the sheet member from the opposite side of the nozzle surface,
A pressure generator that generates pressure applied to the support rollers, and
The inkjet printing apparatus according to claim 11. With the plurality of inkjet heads corresponding to each of the plurality of ink types,
A medium transport device for relatively transporting a medium to be printed using the inkjet head and the inkjet head in the first direction.
With
The inkjet printing apparatus according to any one of claims 9 to 12, wherein the plurality of inkjet heads are arranged along the first direction.

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