JP4678242B2 - Droplet discharge head and droplet discharge apparatus - Google Patents

Description

  The present invention relates to a droplet discharge head that discharges droplets from a nozzle and a droplet discharge device that includes the droplet discharge head.

  In order to perform stable printing in an ink jet printer, it is necessary to maintain the ink wettability uniformly on the nozzle surface of the ink jet recording head. For this reason, a water repellent film is formed on the nozzle surface of the ink jet recording head. This water-repellent film has poor durability against mechanical rubbing due to paper rubbing, paper jam, etc., so a metal plate is laminated on the plate on which the nozzle is formed, and the step structure is such that the nozzle is positioned in the recess. By doing so, it is made difficult for paper to contact the water-repellent film around the nozzle (see, for example, Patent Documents 1 to 3).

  However, as shown in FIG. 14, in the first and second embodiments of Patent Document 1 and Patent Document 2, since the nozzles 50 are surrounded by the recesses 71 one by one, when cleaning the nozzle surface with a wiper Ink I remains in the downstream corner in the direction in which the nozzle in the recess 71 is cleaned (the wiper movement direction indicated by arrow A in the figure). The ink I remaining in the recess 71 covers the water-repellent film to prevent the ink from being made uniform, or accumulates and covers the edge of the nozzle 50 to deteriorate the ink ejection performance.

  On the other hand, in 3rd Embodiment of patent document 2, and patent document 3, the some nozzle arranged in the same direction is provided in the recessed part extended in the direction where the nozzle is arranged. In this configuration, the amount of ink remaining in the recess can be reduced by moving the wiper in the direction in which the recess extends.

However, since the width of the concave portion is wider than the paper thickness and the edge of the paper easily enters the concave portion, the water repellent film around the nozzle may be destroyed.
Japanese Patent No. 3108771 JP 2002-225298 A JP-A-4-169238

  The present invention has been made in consideration of the above-mentioned facts. In the droplet discharge head in which the nozzle is provided in the recess, the amount of liquid remaining in the recess is reduced when the recess is cleaned, and the edge of the paper is reduced. Prevent entry into the recess.

The droplet discharge head according to claim 1 has a surface facing a sheet to be conveyed, and a droplet that discharges droplets to the sheet from a plurality of nozzles provided in a recess formed on the surface. In the ejection head, the plurality of nozzles are arranged in a width direction of the sheet orthogonal to the sheet conveyance direction, and the concave portion has a wide width portion around each nozzle and a width wider than the wide width portion. Ri Do a narrow plurality of the wide portion is extended along the width direction of the sheet and a narrow portion which communicates, characterized in that it is cleaned by the cleaning member to move in the width direction of the sheet along said surface And

  In the droplet discharge head according to the first aspect, a plurality of nozzles for discharging droplets are provided in the recess. In this recess, the wide portion around each nozzle communicates with a narrow portion that is narrower than the wide portion. The narrow portion extends in the traveling direction of the cleaning member that cleans the recess.

  For this reason, when the concave portion is cleaned by the cleaning member, the liquid in each wide width portion flows through the narrow width portion from the upstream side to the downstream side in the moving direction of the cleaning member. As a result, the amount of liquid remaining in each wide portion can be reduced.

  In addition, by making the width of the recess between the nozzles smaller than the width of the recess around the nozzle, the edge of the paper is less likely to enter the recess, resulting from contact between the edge of the paper and the periphery of the nozzle. It is possible to suppress deterioration of the droplet discharge performance.

  The droplet discharge head according to claim 2 is the droplet discharge head according to claim 1, wherein a tapered portion whose width gradually decreases toward the downstream side in the traveling direction of the cleaning member is the wide-width portion. It is characterized by being formed.

  In the droplet discharge head according to claim 2, a tapered portion whose width gradually decreases toward the downstream side in the traveling direction of the cleaning member is formed in the wide portion of the recess, and the recess is cleaned by the cleaning member. When doing so, the liquid in each wide part is moved to the narrow part by the taper part. As a result, the amount of liquid remaining in each wide portion can be reduced.

Droplet discharge head according to claim 3 is the liquid droplet ejection head according to any one of claims 1 to 3, the narrow portion, the traveling direction of the cleaning member with respect to the nozzle It is characterized by being shifted in the orthogonal direction.

In the droplet discharge head according to the third aspect, since the narrow width portion is shifted in the direction orthogonal to the traveling direction of the cleaning member with respect to the nozzle, the cleaning member scrapes off the wide width portion on the upstream side in the traveling direction. Thus, it is possible to reduce the amount of liquid passing over the wide nozzle on the downstream side in the traveling direction. This reduces the possibility that a liquid such as ink that thickens when exposed to air will remain on the nozzle in a thickened state, so that the droplet ejection performance is stabilized .

The droplet discharge head according to claim 4 is unitized by arranging and connecting the droplet discharge head according to any one of claims 1 to 3 in the advancing direction of the cleaning member, and the cleaning member The positions of the respective droplet discharge heads are aligned so that the respective concave portions are aligned with the traveling direction of the cleaning member, and the upstream of the cleaning member in the traveling direction of the cleaning member is located upstream of the concave portion of each droplet discharge head. It is characterized in that a tapered portion having a width gradually increasing toward the side is formed .

According to a fourth aspect of the present invention , the droplet discharge head is unitized by connecting the droplet discharge heads side by side in the direction of travel of the cleaning member, and the cleaning member advances at the upstream end in the direction of travel of the cleaning member in the recess. A thickened portion is formed which gradually increases in width toward the upstream side in the direction. For this reason, even if the alignment between the droplet discharge heads is slightly shifted in the direction intersecting with the traveling direction of the cleaning member, the traveling direction of the cleaning member from the concave portion of the droplet discharging head upstream in the traveling direction of the cleaning member The liquid can be moved to the concave portion of the droplet discharge head on the downstream side. As a result, the amount of liquid remaining at the joint of the droplet discharge heads adjacent to each other in the traveling direction of the cleaning member can be reduced .

According to a fifth aspect of the present invention, there is provided a liquid droplet ejection apparatus according to any one of the first to fourth aspects , a conveyance unit that conveys a sheet so as to face the surface , and a direction in which the concave portion extends. And a cleaning member for cleaning the recess.

In the droplet discharge device according to the fifth aspect, the sheet is conveyed by the conveying means so as to face the surface provided with the recess . Here, since the concave portion of the droplet discharge head has a narrow width between the nozzles, even when the paper conveyed by the conveying means contacts the droplet discharge head due to a jam or the like, the edge of the sheet is difficult to enter into the recess, is less risk of contact occurs with the surrounding paper and the nozzle.

  Further, since the cleaning member moves in the direction in which the recess extends to clean the recess, the liquid in the recess moves to the downstream end in the traveling direction of the cleaning member without remaining around the nozzle. For this reason, the surface state such as the wettability of the liquid around the nozzle can be maintained well, and the droplet discharge performance can be maintained well.

  Since the present invention is configured as described above, in the droplet discharge head in which the nozzle is provided in the recess, the amount of liquid remaining in the recess is reduced when the recess is cleaned, and the edge of the paper is easily placed in the recess. You will not be able to enter.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows an ink jet recording apparatus 12 of the present embodiment. A paper feed tray 16 is provided in the lower part of the casing 14 of the ink jet recording apparatus 12, and the sheets P stacked in the paper feed tray 16 can be taken out one by one by a pickup roll 18. The taken paper P is transported by a plurality of transport roller pairs 20 constituting a predetermined transport path 22.

  Above the paper feed tray 16, an endless transport belt 28 stretched around a drive roll 24 and a driven roll 26 is disposed. A recording head array 30 is disposed above the conveyor belt 28 and faces the flat portion 28F of the conveyor belt 28. This opposed area is an ejection area SE where ink droplets are ejected from the recording head array 30. The sheet P transported along the transport path 22 is held by the transport belt 28 and reaches the discharge area SE, and ink droplets corresponding to image information are attached from the recording head array 30 in a state of facing the recording head array 30. The

  In this embodiment, the recording head array 30 has a long shape in which the effective recording area is equal to or larger than the width of the paper P (the length in the direction orthogonal to the transport direction), and is yellow (Y) and magenta (M). , Sian (S), and four inkjet recording head units (hereinafter referred to as head units) 32 corresponding to the four colors of black (K) are arranged along the transport direction so that a full-color image can be recorded. It has become.

  Each head unit 32 is controlled by a recording head control means (not shown). For example, the recording head control means determines the ink droplet ejection timing and the ink ejection port (nozzle) to be used according to the image information, and sends a drive signal to the head unit 32.

  The recording head array 30 may be stationary in a direction orthogonal to the transport direction. However, if the recording head array 30 is configured to move as necessary, an image with higher resolution can be obtained by multi-pass image recording. Can be recorded, or troubles of the head unit 32 can be prevented from being reflected in the recording result.

  Four maintenance units 34 corresponding to the respective head units 32 are arranged on both sides of the recording head array 30. As shown in FIG. 2, when performing maintenance on the head unit 32, the recording head array 30 moves upward, and the maintenance unit 34 moves into the gap formed between the conveyance belt 28 and enters. Then, a predetermined maintenance operation (suction, wiping, capping, etc.) is performed while facing the nozzle surface 32N (see FIG. 3).

  As shown in FIG. 3, a charging roll 36 to which a power source 38 is connected is disposed on the upstream side of the recording head array 30. The charging roll 36 is driven while sandwiching the conveyance belt 28 and the paper P with the driven roll 26, and moves between a pressing position for pressing the paper P against the conveyance belt 28 and a separation position separated from the conveyance belt 28. It is possible. At the pressing position, a predetermined potential difference is generated between the grounded driven roll 26 and the sheet P can be charged and electrostatically attracted to the transport belt 28.

  A separation plate 40 is disposed on the downstream side of the recording head array 30 and separates the paper P from the conveyance belt 28. The peeled paper P is transported by a plurality of discharge roller pairs 42 that constitute a discharge path 44 on the downstream side of the peeling plate 40, and is discharged to a paper discharge tray 46 provided on the top of the housing 14.

Here, the configuration of the head unit 32 will be described. Although only one head unit 32 is illustrated and described here, all the head units 32 have the same configuration.
[First Embodiment]
As shown in FIGS. 4 and 5, the head unit 32 includes an inkjet recording head (hereinafter referred to as a recording head) 10 in which a plurality of nozzles 50 are arranged along the width direction of the paper P (a direction orthogonal to the transport direction). However, a plurality (four in this embodiment) are arranged along the width direction of the paper P. The recording heads 10 are alternately mounted on one surface and the other surface of the support plate 53 extending along the width direction of the paper P, and have a staggered arrangement.

  The recording head 10 is mounted on an ink discharge section 10A in which an ink flow path and a pressure chamber are formed by laminating a nozzle plate, a flow path plate, a vibration plate (both not shown) and the like, and the ink discharge section 10A. And an ink supply unit 10B communicated with the ink flow path of the ink discharge unit 10A. Piezoelectric elements are bonded to the vibration plate of the ink discharge unit 10 </ b> A corresponding to each pressure chamber.

  Further, an ink supply path 58 extending in the width direction of the paper P is attached to the upper portion of the support plate 53. The ink supply path 58 is connected to the ink tank 54 (see FIG. 1). Further, four ink supply path branches 60A to 60D are branched from the ink supply path 58, and these ink flow path branches 60A to 60D extend downward from the lower part of the ink supply path 58 so that each recording head 10 It is connected to the upper part of the ink supply unit 10B. That is, the ink is sent from the ink tank 54 and flows through the common ink supply path 58, and then is divided into the ink supply path branches 60A to 60D and flows into the ink supply section 10B of each recording head.

  As shown in FIGS. 6A and 6B, a metal plate (for example, SUS plate) 64 is laminated on the nozzle plate 62 of the recording head 10. A through hole exposing the nozzle 50 is formed in the metal plate 64 to form a recess 70 on the nozzle plate 62, and the nozzle 50 is provided in the recess 70. Further, the surface of the metal plate 64 and the inside of the recess 70 are covered with a water repellent film 66 made of a fluorine resin or the like.

  Further, as shown in FIG. 6A, the nozzle surface of the recording head 10 is wiped by a wiper blade 72 that moves along the width direction of the paper P in contact with the nozzle surface during a maintenance operation. A wiper cleaner 74 that is an absorbent body such as a sponge is disposed at the downstream end of the moving direction of the wiper blade 72 (arrow A in the figure, hereinafter referred to as “wipe direction”). The ink scraped off from the nozzle surface is absorbed by the wiper cleaner 74.

  Here, the nozzles 50 are arranged along the wipe direction, and the recesses 70 extend along the wipe direction. The recess 70 includes a wide-width portion 70A having a pentagonal shape around the nozzle 50 and a narrow-width portion 70B that is narrower than the wide-width portion 70A and extends in the wiping direction and communicates with the plurality of wide-width portions 70A. ing.

  For this reason, when the wiper blade 72 moves in the wipe direction, the ink staying in each of the wide width portions 70A flows from the upstream side to the downstream side in the wipe direction through the narrow width portion 70B. As a result, the amount of ink remaining in each wide portion 70A can be reduced.

  In addition, since the width of the recess 70 between the nozzles 50 is narrower than the width of the recess 70 around the nozzle 50, the edge of the paper P is difficult to enter the recess 70, and the edge of the paper P becomes the nozzle The contact with the peripheral portion of the nozzle 50 reduces the possibility that the water-repellent film 66 in the peripheral portion of the nozzle 50 is mechanically destroyed.

  Therefore, the wettability of the ink around the nozzle 50 can be made uniform, and deterioration of the ink droplet ejection performance can be suppressed.

  Further, as shown in FIG. 7, the width in the wipe direction upstream from the nozzle 50 of the wide portion 70A is uniformly wider, and the downstream in the wipe direction from the nozzle 50 of the wide portion 70A is gradually wider toward the downstream side. The taper portion (tapered portion) 70C becomes narrower. For this reason, when the wiper blade 72 moves in the wipe direction, the ink I staying in the wide portion 70A is moved to the narrow portion 70B by the tapered portion 70C and passes through the narrow portion 70B on the downstream side in the wipe direction. Move to the wide portion 70A.

  Accordingly, the amount of ink remaining in each of the wide portions 70A can be further reduced, and the wettability of the ink around the nozzle 50 can be made more uniform, so that deterioration in ink droplet ejection performance can be further suppressed.

  By the way, as shown in FIGS. 7 and 8A, an area that is not wiped off by the wiper blade 70 is formed at the corner of the wide portion 70A. For example, when wiping the wide portion 70A with a depth h of 10 μm by the wiper blade 72 having a hardness of 50 degrees and a plate thickness of 1.5 mm and a rectangular cross section, wiping the corner (one side) of the wide portion 70A The impossible width d is 5 μm. For this reason, in the wide width portion 70A in which the nozzle 50 having a depth h of 10 μm and a diameter of 25 μm is formed, the width D of the wide width portion 70A needs to be 35 μm or more so that the periphery of the nozzle 50 can be wiped off. Yes (see table in FIG. 8B).

  When only the depth h is 20 μm under the above-described conditions, the width d that cannot be wiped is 25 μm, and the width D of the wide portion 70A needs to be 75 μm or more. Similarly, when the depth h is 50 μm, the non-wiping width d is 60 μm, and the width D of the wide width portion 70A needs to be 145 μm or more.

In the present embodiment, the tapered portion provided in the wide width portion 70A is tapered. However, the tapered portion only needs to gradually become narrower toward the downstream side in the wipe direction. It may be curvilinear.
[Second Embodiment]
Next, a second embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

As shown in FIG. 9, in the recording head 80, the nozzles 50 are arranged in a staggered pattern along the wiping direction. As in the first embodiment, the recess 70 extends in the wipe direction, and the wide portions 70A and the narrow portions 70B are alternately arranged in the wipe direction. Further, in the plurality of rows of recesses 70, the wide portions 70A and the narrow portions 70B are alternately arranged in the direction orthogonal to the wipe direction, and the recesses 70 are recessed by the narrow portions 70B. The swelled portion by the wide portion 70A is fitted. Thereby, the concave portions 70 and the nozzles 50 can be arranged with high density.
[Third embodiment]
Next, a third embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st, 2nd embodiment, and description is abbreviate | omitted.

  As shown in FIG. 10, in the head unit 82, a plurality of recording heads 90 are arranged on a straight line along the wiping direction. In each recording head 90, as in the recording head 10 of the first embodiment, a plurality of nozzles 50 are arranged on a straight line along the wipe direction, and a recess 70 extends along the wipe direction.

  Here, at the upstream end portion of the recess 70 in the wipe direction, a reverse taper portion (tapered portion) 70 </ b> D that gradually increases in width from the narrow width portion 70 </ b> B to the upstream side in the wipe direction is formed. For this reason, when the plurality of recording heads 90 are arranged in the wipe direction as a unit, even if the alignment between the recording heads 90 is slightly shifted in the direction crossing the wipe direction, the recording head 90 on the upstream side in the wipe direction. The ink can be moved from the concave portion 70 to the concave portion 70 of the recording head 90 on the downstream side in the wiping direction. As a result, the amount of ink remaining at the joint between the recording heads 90 adjacent in the wipe direction can be reduced.

In the present embodiment, the taper portion provided at the upstream end portion in the wipe direction of the recording head 90 is tapered. However, the taper portion only needs to gradually increase in width toward the upstream side in the wipe direction. The width may be curvilinear.
[Fourth embodiment]
Next, a fourth embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st thru | or 3rd embodiment, and description is abbreviate | omitted.

  As shown in FIG. 11, in the recording head 100, the nozzles 50 are arranged on a straight line along the wipe direction, and the recess 102 extends along the wipe direction. The recess 102 includes a wide-width portion 102A having a trapezoidal shape around the nozzle 50, and a narrow-width portion 102B that is narrower than the wide-width portion 102A and extends in the wipe direction and communicates with the plurality of wide-width portions 102A. ing.

  The upstream side in the wipe direction from the nozzle 50 of the wide width portion 102A is uniformly wider, and the downstream side in the wipe direction from the nozzle 50 of the wide width portion 102A is a taper portion that gradually becomes narrower toward the downstream side in the wipe direction ( Tapered portion) 102C. For this reason, when the wiper blade 72 moves in the wipe direction, the ink adhering in the wide width portion 102A is moved to the narrow width portion 102B by the taper portion 102C and passes through the narrow width portion 102B to the wide width downstream of the wipe direction. Move to section 102A.

Here, by biasing the narrow portion 102B to one side in the direction orthogonal to the wipe direction of the wide portion 102A, the narrow portion 102B is scraped off by the wide portion 102A on the upstream side in the wipe direction and the wide portion 102A on the downstream side in the wipe direction. The amount of ink passing over the nozzle 50 can be reduced. As a result, the possibility that the thickened ink remains on the nozzle is reduced, and the ink ejection performance is stabilized.
[Fifth Embodiment]
Next, a fifth embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st thru | or 4th embodiment, and description is abbreviate | omitted.

  As shown in FIG. 12, in the recording head 110, the nozzles 50 are arranged in a zigzag pattern along the wipe direction, and the recesses 112 extend along the wipe direction. The recess 112 communicates with the plurality of wide portions 112A through a wide width portion 112A having a trapezoidal shape around the nozzle 50 and the nozzles 50 having a width narrower than the wide width portion 112A and arranged in a staggered manner. It is comprised by the narrow part 112B.

Here, the plurality of wide portions 112A are arranged in a staggered pattern in the wipe direction. Further, the narrow portion 112B extends through a plurality of wide portions 112A arranged in a staggered manner. For this reason, as in the fourth embodiment, the narrow width portion 112B is biased to one side or the other side in the direction orthogonal to the wipe direction of the wide width portion 112A, so that the wipe is scraped off by the wide width portion 112A on the upstream side in the wipe direction. The amount of ink passing over the nozzle 50 of the wide portion 112A on the downstream side in the direction is reduced. As a result, the possibility that the thickened ink remains on the nozzle is reduced, and the ink ejection performance is stabilized.
[Sixth Embodiment]
Next, a sixth embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st thru | or 5th embodiment, and description is abbreviate | omitted.

  As shown in FIG. 13, in the recording head 120, the nozzles 50 are arranged on a straight line along the wipe direction, and the concave portion 122 extends in the wipe direction. The recess 122 includes a wide portion 122A having the nozzle 50 at the center, and two narrow portions 122B that are narrower than the wide portion 122A and pass through both ends in the width direction of the wide portion 122A. The width in the wiping direction upstream from the nozzle 50 of the wide portion 122A is uniform. Further, a pair of tapered portions 122C whose width gradually narrows from the center line of the nozzle 50 extending in the wipe direction to the narrow width portions 122B on both sides is formed on the downstream side of the nozzle 50 of the wide width portion 122A. Has been.

Also in this embodiment, as in the fourth and fifth embodiments, the narrow width portion 122B is offset from the center line of the nozzle 50 extending in the wipe direction, so that the wide width portion 122A on the upstream side in the wipe direction is scraped off. The amount of ink passing over the nozzle 50 of the wide portion 122A on the downstream side in the wipe direction is reduced.
[Seventh embodiment]
Next, a seventh embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st thru | or 6th embodiment, and description is abbreviate | omitted.

  As shown in FIG. 14, in the recording head 130, the nozzles 50 are arranged in a staggered pattern along the wipe direction. The recess 132 is formed by a wide portion 132A and a narrow portion 132B having the same shape as the wide portion 122A and the narrow portion 122B of the sixth embodiment. All the wide portions 132A arranged in a staggered pattern along the wipe direction are communicated with each other by narrow portions 132B extending through the wide portions 132A and extending in the wipe direction.

  Also in the present embodiment, as in the fourth to sixth embodiments, the narrow portion 132B is offset from the center line of the nozzle 50 extending in the wipe direction, so that it is scraped off by the wide portion 132A on the upstream side in the wipe direction. The amount of ink that passes over the nozzle 50 of the wide portion 132A on the downstream side in the wipe direction is reduced.

  In the first to seventh embodiments, the present invention has been described by taking an ink jet recording apparatus as an example. However, the droplet discharge head of the present invention is not limited to an ink jet recording head, and is colored on a polymer film or glass. Production of display color filter by discharging ink, formation of bump for component mounting by discharging molten solder onto substrate, formation of EL display panel by discharging organic EL solution onto substrate In addition, the present invention is applicable to general liquid droplet ejection heads intended for various industrial uses such as formation of bumps for electrical mounting performed by discharging molten solder onto a substrate.

  In addition, the “recording medium” that is a target of image recording in the droplet discharge head and the droplet discharge apparatus of the present invention includes a wide variety of objects as long as the droplet discharge head is a target for discharging droplets. Therefore, the recording medium includes a recording sheet, an OHP sheet, and the like, but also includes, for example, a substrate on which a wiring pattern or the like is formed.

  Furthermore, in the first to seventh embodiments, the present invention has been described by taking as an example a configuration in which a plurality of inkjet recording heads shorter than the width of the paper P are arranged in the width direction of the paper P as a unit. For example, the droplet discharge head of the present invention can be applied to a configuration in which an inkjet recording head shorter than the width of the paper P is moved in the width direction of the paper P.

1 is a diagram showing an outline of an ink jet recording apparatus according to an embodiment of the present invention. 1 is a diagram showing an outline of an ink jet recording apparatus according to an embodiment of the present invention. It is a figure which shows the outline of the printing part of the inkjet recording device of embodiment of this invention. 1 is a perspective view illustrating an inkjet recording head unit according to a first embodiment of the present invention. 1 is a perspective view illustrating an inkjet recording head unit according to a first embodiment of the present invention. FIG. 2A is a plan view of the ink jet recording head according to the first embodiment of the present invention, and FIG. FIG. 3 is an enlarged plan view showing a recess of the ink jet recording head according to the first embodiment of the present invention. 6A is a cross-sectional view taken along the line BB in FIG. 6A, and FIG. 6B is a table summarizing the relationship between the depth h of the recess, the non-wiping width d of the recess, and the minimum width D of the wiping recess. . It is a top view which shows the inkjet recording head of 2nd Embodiment of this invention. It is a top view which shows the inkjet recording head of 3rd Embodiment of this invention. It is a top view which shows the inkjet recording head of 4th Embodiment of this invention. It is a top view which shows the inkjet recording head of 5th Embodiment of this invention. It is a top view which shows the inkjet recording head of 6th Embodiment of this invention. It is a top view which shows the inkjet recording head of 7th Embodiment of this invention. It is a top view which expands and shows the recessed part of the conventional inkjet recording head.

Explanation of symbols

10 Inkjet recording head (droplet ejection head)
12 Inkjet recording device (droplet ejection device)
28 Conveying belt (conveying means)
50 Nozzle 70 Recess 70A Wide part 70B Narrow part 70C Tapered part (tapered part)
70D Inverse taper part (tapered part)
72 Wiper blade (cleaning member)
80 Inkjet recording head (droplet discharge head)
90 Inkjet recording head (droplet discharge head)
100 Inkjet recording head (droplet ejection head)
102 Concave portion 102A Wide portion 102B Narrow portion 102C Tapered portion (tapered portion)
110 Inkjet recording head (droplet ejection head)
112 concave portion 112A wide portion 112B narrow portion 112C tapered portion (tapered portion)
120 Inkjet recording head (droplet ejection head)
122 recessed portion 122A wide portion 122B narrow portion 122C taper portion (tapered portion)
130 Inkjet recording head (droplet ejection head)
132A Wide part 132B Narrow part 132C Tapered part (tapered part)
P Paper (sheet)

Claims (5)

A droplet discharge head having a surface facing a sheet to be conveyed and discharging droplets to the sheet from a plurality of nozzles provided in recesses formed on the surface ;
The plurality of nozzles are arranged in a paper width direction orthogonal to the paper transport direction,
The recess, Ri Do from the wide portion of the periphery of each nozzle, the narrow portion communicating a plurality of said wide portion is extended along the width direction of the narrow and the paper than the wide portion, the surface A droplet discharge head, wherein the droplet discharge head is cleaned by a cleaning member that moves in the width direction of the sheet along the line .   2. The droplet discharge head according to claim 1, wherein a tapered portion whose width gradually decreases toward the downstream side in the traveling direction of the cleaning member is formed in the wide portion. Wherein the narrow portion, the liquid droplet ejection head according to claim 1 or claim 2, characterized in that to said nozzle is shifted in a direction perpendicular to the advancing direction of the cleaning member. The droplet discharge head according to any one of claims 1 to 3 is united by arranging and connecting the droplet discharge heads in the advancing direction of the cleaning member, and each concave portion is aligned in the advancing direction of the cleaning member. The position of the droplet discharge head is aligned, and the width of the concave portion of each droplet discharge head gradually increases toward the upstream end in the traveling direction of the cleaning member toward the upstream side in the traveling direction of the cleaning member. A unitized droplet discharge head characterized by forming a section. A droplet discharge head according to any one of claims 1 to 4,
A conveying means for conveying the paper so as to face the surface ;
A cleaning member that moves in a direction in which the recess extends to clean the recess;
A droplet discharge apparatus comprising:

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