JP5733992B2 - Ink ejection head - Google Patents

Description

  The present invention relates to an ink discharge head that can be used in an ink jet recording apparatus.

  In recent years, an on-demand type capable of highly flexible data processing has been widely used as an ink jet recording apparatus. In such an ink jet recording apparatus, high definition and high speed recording are required.

  An ink jet recording apparatus performs recording using an ink discharge head that performs an ink discharge operation. In the ink discharge operation by the ink discharge head, first, the ink supplied from the ink tank flows into the ink chamber through the flow path. An energy generating element is provided in the ink chamber, and the energy generating element generates energy to instantaneously increase the pressure in the ink chamber. Thereby, ink in the ink chamber is discharged from an ink discharge port (hereinafter referred to as “nozzle”) provided in the ink chamber.

  In order to achieve high definition recording by the ink jet recording apparatus, it is required that the ejection operation by the ink ejection head be accurately performed. Accurate ink ejection operation can be achieved by miniaturization of ejected ink droplets. In order to form fine ink droplets, it is effective to use a highly viscous ink with a low solvent content. Examples of the solvent used in the ink include water and organic liquid.

  On the other hand, high-viscosity ink has the property of not easily flowing. Therefore, in the case of high-viscosity ink, replenishment of ink into the ink chamber (hereinafter referred to as “refill”) in which the amount of ink has decreased after the ink ejection operation may be delayed. If the refill delay continues, the amount of ink in the ink chamber will eventually become insufficient, and the ink ejection head will not be able to perform the ink ejection operation normally.

  Patent Document 1 discloses an ink ejection head having a configuration in which refill delay is unlikely to occur. In a general ink ejection head, a partition wall that separates an ink chamber and a flow path is formed of a material such as a resin, and refilling is performed from the flow path through an opening provided in a part of the partition wall. On the other hand, the partition walls of the ink discharge head described in Patent Document 1 are formed of a porous material such as sponge or ceramics. The porous material is composed of a tissue having innumerable pores, and the ink can pass through the pores in the porous material. Therefore, in this ink discharge head, it is possible to perform a quick refill from the flow path through the entire partition wall.

JP-A-5-185593

  In the ink discharge head described in Patent Document 1, although quick refill is possible, if the ink stays in the vicinity of the nozzle when not in use, the solvent contained in the ink evaporates from the nozzle, and the ink in the vicinity of the nozzle The viscosity becomes higher. The ink having such a high viscosity may stay in the vicinity of the nozzle. In this state, even if the ink ejection head tries to perform the ink ejection operation again, the ink staying in the vicinity of the nozzle is not ejected and causes clogging of the nozzle. Nozzle clogging is noticeable when high viscosity ink is used.

  In order to prevent clogging of the nozzles, there is an ink discharge head that flows ink near the nozzles when not in use. In such an ink discharge head, the ink hardly stays in the vicinity of the nozzle, and the nozzle is not easily clogged. However, even in such an ink discharge head, there is a case where the solvent evaporates from the ink near the nozzle and thickens when not in use, and the ink near the nozzle gradually accumulates without flowing. In such a case, as described above, the ink staying in the vicinity of the nozzle causes clogging of the nozzle.

  SUMMARY An advantage of some aspects of the invention is that it provides an ink discharge head capable of preventing nozzle clogging.

In order to achieve the above object, the ink ejection head of the present invention has a first wall portion in which nozzles for ejecting ink are formed on a peripheral wall constituting an ink chamber to which ink is supplied , and ink can pass therethrough. A second wall portion configured to include a plurality of second wall portions, the second wall portion extending from a position relatively far from the first wall portion toward a side closer to the first wall portion. The plurality of columnar bodies are arranged on the first wall portion so that the ink flow resistance is lower on the side relatively closer to the first wall portion than on the far side. It is characterized in that the lengths extending toward it are different .

  According to the present invention, it is possible to provide an ink discharge head capable of preventing nozzle clogging.

1 is a schematic configuration diagram of an ink discharge head according to a first embodiment of the present invention. FIG. 2 is a plan view of the ink ejection head illustrated in FIG. 1. FIG. 2 is a partial cross-sectional view illustrating a manufacturing process of the ink discharge head illustrated in FIG. 1. It is a perspective view of the partition of the ink discharge head which concerns on the 2nd Embodiment of this invention. FIG. 5 is a partial cross-sectional view illustrating a manufacturing process of an ink ejection head including the partition wall illustrated in FIG. 4. It is a fragmentary sectional view of the partition of the ink discharge head which concerns on the 3rd Embodiment of this invention. FIG. 7 is a partial cross-sectional view illustrating a manufacturing process of the ink ejection head illustrated in FIG. 6. It is a top view of the ink discharge head which concerns on the 4th Embodiment of this invention. It is a top view of the ink discharge head which concerns on the 5th Embodiment of this invention.

Next, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1A is a partial cross-sectional view of the ink ejection head according to the first embodiment of the present invention. In this ink ejection head, two plate-like members, the nozzle plate 30 and the bottom substrate 70 are arranged to face each other. A partition wall 20 is sandwiched between the nozzle plate 30 and the bottom substrate 70. A space between the nozzle plate 30 and the bottom substrate 70 is divided by the partition wall 20 into a flow path 41, an ink chamber 10, and a flow path 42. The partition wall 20 is sandwiched between the nozzle plate 30 and the bottom substrate 70. That is, the ink chamber 10 is constituted by a peripheral wall constituted by the partition wall 20, the nozzle plate 30, and the bottom substrate 70.

  At a position corresponding to the ink chamber 10 of the nozzle plate 30 that is the first wall portion, a nozzle 35 that communicates the ink chamber 10 with the external space is opened. In the ink chamber 10, an ejection energy generating element 60 provided on the bottom substrate 70 is provided at a position facing the nozzle 35.

  In the ink discharge operation of the ink discharge head, the ink supplied into the ink chamber 10 can be discharged from the nozzle 35 to the external space by the energy generated by the discharge energy generating element 60. Here, the direction in which ink is ejected from the nozzle 35 toward the external space is referred to as the ejection direction. The discharge direction is a direction perpendicular to the nozzle plate 30 and is an upward direction shown in FIG. When this ink ejection head is used in an ink jet recording apparatus, recording is performed on a recording medium such as paper by this ink ejection operation. When ink in the ink chamber 10 is ejected from the nozzle 35 during the ink ejection operation, ink replenishment (refill) into the ink chamber 10 is performed from the flow paths 41 and 42 through the partition wall 20.

  The detail of the partition 20 which is a 2nd wall part is demonstrated with reference to FIG. 1 (B) and FIG.1 (C). FIG. 1B is a perspective view showing the partition 20 in an enlarged manner, and FIG. 1C is a plan view showing the partition 20 in an enlarged manner. 1B and 1C, the nozzle plate 30 and the bottom substrate 70 are omitted.

  The partition wall 20 includes a structure in which a plurality of columnar bodies 50 standing upright from the bottom substrate 70 illustrated in FIG. 1A are arranged in a matrix at equal intervals. Each columnar body 50 has a circular cross section parallel to the bottom substrate 70 and is continuously narrowed from the bottom substrate 70 toward the nozzle plate 30. In other words, each columnar body 50 has a shape in which the top of the cone is cut out parallel to the bottom surface.

  A gap is formed between the columnar bodies 50 in the structure constituting the partition wall 20. The ink can flow in the partition wall 20 through the gap. In this ink discharge head, it is only necessary that the ink can flow between the flow path 41, the ink chamber 10, and the flow path 42. For this reason, the partition wall 20 may be configured to allow ink to pass in a direction intersecting the ejection direction. With this configuration, in this ink ejection head, the ink in the flow paths 41 and 42 flows through the entire partition 20 into the ink chamber 10 during refilling.

  Here, it is assumed that the partition wall of the ink discharge head is formed of a porous material such as sponge or ceramics. These porous materials are generally composed of a structure in which pores having different sizes are dispersed non-uniformly. The speed at which the ink passes through the porous material increases as the size of the pores increases and the amount of the pores increases. Therefore, the speed at which the ink passes through the partition wall depends on the structure constituting the partition wall. Accordingly, in such an ink ejection head, the speed of ink passing through the partition wall during refilling varies depending on the ink chamber, and therefore the refilling speed varies depending on the ink chamber.

  On the other hand, the partition wall 20 of the ink ejection head according to the present embodiment has a structure in which the columnar bodies 50 are arranged in a matrix at equal intervals. That is, the gaps between the columnar bodies 50 constituting the partition wall 20 surrounding the ink chamber 10 are the same in all the ink chambers 10. Therefore, the speed of the ink passing through the partition wall 20 during refilling is the same regardless of the ink chamber. That is, the refill speed in each ink chamber 10 is constant. Therefore, with this ink ejection head, it is possible to replenish an accurate amount of ink to all the ink chambers 10 during refilling.

  FIG. 2 is a plan view of the ink discharge head shown in FIG. In FIG. 2, the nozzle plate 30 and the ejection energy generating element 60 are omitted, and the position of the nozzle 35 is indicated by a broken line. The ink chamber 10 is surrounded by the partition wall 20 from a direction parallel to the nozzle plate 30, and the flow paths 41 and 42 are adjacent to the partition wall 20. Each nozzle 35 is provided corresponding to each ink chamber 10, and the plurality of ink chambers 10 and the plurality of nozzles 35 are arranged in one direction along the flow paths 41 and 42.

  This ink discharge head is configured to perform an ink replacement operation in which the ink in the ink chamber 10 flows when not in use and the ink in the vicinity of the nozzles is constantly replaced. In this ink replacement operation, ink flows in the order of the flow path 41, the ink chamber 10, and the flow path 42. Considering the details of the ink flow path in the ink replacement operation, the ink flows while changing its direction microscopically. However, here, the ink flows in the direction intersecting the ejection direction and the arrangement direction of the ink chambers 10 (for example, the arrow direction shown in FIG. 2) regardless of the microscopic flow path. 41, the ink chamber 10, and the flow path 42 may flow. Therefore, the partition 20 may be configured such that ink cannot flow in the arrangement direction of the ink chambers 10 (the left-right direction shown in FIG. 2).

  During the ink replacement operation, the columnar body 50 of the partition wall 20 has a shape that continuously narrows from the bottom substrate 70 toward the nozzle plate 30 shown in FIG. Becomes wider as it is closer to the nozzle plate 30. Therefore, the ink has a lower flow resistance as it is closer to the nozzle plate 30, and has a higher flow resistance as it is farther from the nozzle plate 30, that is, closer to the bottom substrate 70. Therefore, the flow rate of the ink passing through the partition wall 20 during the ink replacement operation is relatively faster as it is closer to the nozzle plate 30 and is relatively slower as it is closer to the bottom substrate 70.

  Due to the configuration of the partition wall 20 described above, in this ink ejection head, the ink flow velocity in the ink chamber 10 during the ink replacement operation is the fastest in the vicinity of the nozzle 35. Therefore, since the ink stays in the vicinity of the nozzle 35 for a short time, the solvent component does not easily evaporate. Further, even if there is ink collected in the vicinity of the nozzle, it can be effectively replaced by this configuration. Therefore, in the ink ejection head according to the present embodiment, even when high-viscosity ink is used, it is difficult to stay in the vicinity of the nozzle 35 and the nozzle 35 is not easily clogged.

  The partition wall 20 may have a structure in which the end portion closer to the nozzle plate 30 can relatively increase the ink passage speed than the end portion closer to the bottom substrate 70. For example, the thickness of the columnar body 50 shown in FIG. 1 is formed so as to be continuously reduced from the bottom substrate 70 toward the nozzle plate 30, but may be formed so as to be gradually reduced. .

  Further, “the end portion closer to the nozzle plate 30” of the partition wall 20 indicates a portion of the partition wall 20 within a certain distance from the nozzle plate 30. This fixed distance can be arbitrarily determined within 50% of the length of the partition wall 20 in the ejection direction.

  Similarly, “the end portion closer to the bottom substrate 70” of the partition wall 20 indicates a portion of the partition wall 20 within a certain distance from the bottom substrate 70. This fixed distance can be arbitrarily determined within 50% of the length of the partition wall 20 in the ejection direction.

  Next, with reference to FIG. 3, a method for manufacturing the ink ejection head according to the present embodiment will be described. FIG. 3 is a partial cross-sectional view illustrating the manufacturing process of the ink ejection head according to the present embodiment. Portions other than the portion shown in FIG. 3 of the ink discharge head according to the present embodiment can be manufactured by the same technique as that of a general ink discharge head.

  A general MEMS (Micro Electro Mechanical Systems) technique can be used for the manufacturing technique of the ink discharge head. Examples of the MEMS technique include an etching technique, a plating technique, a laser ablation technique, and a dicing technique. The technique used in the present embodiment is merely an example, and an appropriate technique can be appropriately selected for manufacturing the ink ejection head.

  In this embodiment, first, a Cr thin film 110 is formed on the surface of the Si substrate 100 as shown in FIG. The film thickness of the Cr thin film 110 was 200 nm, and the electron beam evaporation method was used as the film formation method. The film thickness of the Cr thin film 110 is preferably about several hundred nm, and a Si oxide film may be formed instead of the Cr thin film 110. Further, instead of the Si substrate 100, a substrate formed of Ni or SUS can be used.

  Next, as shown in FIG. 3B, a pattern 111 was formed by removing a part of the Cr thin film 110 using a photolithography technique and an etching technique. The dimension of the pattern 111 can be appropriately selected within a range from several μm to several mm. Further, the interval between the patterns 111 can be appropriately selected within a range of several μm to several mm.

  Next, as shown in FIG. 3C, the surface of the Si substrate 100 was etched using the pattern 111 as a mask. As an etching technique, a Bosch process was used. In the present embodiment, by performing etching while sequentially changing the etching conditions such as the gas flow rate and the processing time, a groove having an obtuse angle between the bottom surface and the side surface is formed. This groove serves as a gap between the ink chamber 10 and the columnar body 50. This step can also be performed by alternately performing etching and surface protection.

  The depth of the groove formed by etching is appropriately determined depending on the size of the ink chamber 10 and the length of the columnar body 50, and is preferably in the range of 10 μm to several mm. In this embodiment, it is 20 μm.

  Next, as shown in FIG. 3D, the pattern 111 was removed with a Cr etching solution. Through the steps described above, the bottom substrate 70 and the partition wall 20 are integrally formed. Instead of forming the bottom substrate 70 and the partition wall 20 integrally, a method may be used in which the bottom substrate 70 and the partition wall 20 are separately prepared and bonded together. As a bonding method, there are direct bonding between substrates and indirect bonding in which a bonding material is applied to the bonding surface of the substrates. Examples of indirect bonding include bonding via a metal film (for example, Au), bump bonding, and bonding using an adhesive. When both are bonded, the manufacturing method and the extraction of the electrode may be simplified by forming the ejection energy generating element 60 on the bottom substrate 70 and then bonding them.

  The columnar body 50 can be formed of, for example, a metal material such as Ni or SUS, a resin material such as SU-8 or polyimide, or a ceramic material such as PZT in addition to a semiconductor material such as Si. The diameter of the cross section of the columnar body 50 is preferably in the range of several μm to several mm. In this embodiment, the upper end on the nozzle plate 30 side is 3 μm and the lower end on the bottom substrate 70 side is 6 μm. It was made to become. The shape of the cross section of the columnar body 50 may be, for example, a polygon such as a quadrangle or an ellipse other than a circle. The arrangement of the columnar bodies 50 on the bottom substrate 70 may be other than the matrix form as in the present embodiment as long as it has regularity. The interval between the columnar bodies 50 is preferably within a range of several μm to several mm, and is 8 μm in this embodiment.

  It is desirable to perform a surface modification treatment on the surface of the columnar body 50 of the partition wall 20 by forming an appropriate single layer film or multilayer film. For example, in consideration of ink resistance, electrical characteristics, wettability, and the like, a corrosion resistant film, an insulating film, or a metal film may be formed on the surface of the bottom substrate 70 or the partition wall 20. In the present embodiment, a parylene thin film having a thickness of about 0.5 μm is formed on the surface of the columnar body 50 by a CVD (Chemical Vapor Deposition) method. Instead of the parylene thin film, a heat treatment in oxygen may be performed on the surface of the columnar body 50 to form an Si oxide film.

  Finally, as shown in FIG. 1A, the ejection energy generating element 60 is provided on the bottom substrate 70, and the nozzle plate 30 is provided on the partition wall 20. The timing of forming the nozzle 35 of the nozzle plate 30 may be before the nozzle plate 30 is provided on the partition wall 20 or after the nozzle plate 30 is provided on the partition wall 20.

  As a discharge energy generating element, a heater generally used for a thermal ink discharge head is provided, but another element capable of generating discharge energy may be provided. Examples of other ejection energy generating elements include piezoelectric elements. The ejection energy generating element is connected to a circuit board (not shown) and driven by the circuit board.

  In the present embodiment, the nozzle plate 30 is formed of Ni, but may be formed of other metal materials such as SUS, semiconductor materials such as Si, and resin materials such as polyimide. The thickness of the nozzle plate 30 is preferably in the range of 5 μm to 100 μm, and in this embodiment, it is 15 μm. The inner diameter of the nozzle 35 is preferably within a range from several nm to several μm, and in this embodiment, it is 8 μm.

In the present embodiment, the nozzles 35 are formed on the nozzle plate 30, but the nozzles 35 are not necessarily formed on a plate-like member. For example, the nozzle 35 may be formed on a member formed integrally with the partition wall 20.
(Second Embodiment)
FIG. 4 is a perspective view of the partition 20a of the ink discharge head according to the second embodiment of the present invention. The configuration of the ink ejection head according to the present embodiment is the same as that of the ink ejection head according to the first embodiment except for the partition wall 20a.

  The partition wall 20a according to the present embodiment is configured by a plurality of columnar bodies 51 and 52 having a columnar shape extending from the bottom substrate 70 (see FIG. 1) and arranged alternately in a matrix. The columnar body 51 and the columnar body 52 have different lengths, and the columnar body 51 extends to the nozzle plate 30 (see FIG. 1), whereas the columnar body 52 extends halfway toward the nozzle plate 30.

  The structure constituting the partition wall 20a has both the columnar body 51 and the columnar body 52 at the end closer to the bottom substrate 70, whereas only the columnar body 51 exists at the end closer to the nozzle plate 30. Absent. Accordingly, the gap between the partition walls 20 a through which ink can pass is wide at the end portion closer to the nozzle plate 30 and narrow at the end portion closer to the bottom substrate 70. Therefore, the flow rate of the ink passing through the partition wall 20 a during the ink replacement operation is faster at the end portion closer to the nozzle plate 30 than at the end portion closer to the bottom substrate 70.

  Due to the configuration of the partition wall 20a described above, in this ink ejection head, the flow rate of the ink in the ink chamber 10 during the ink replacement operation increases near the nozzle 35 (see FIG. 1). Therefore, since the ink stays in the vicinity of the nozzle 35 for a short time, the solvent component does not easily evaporate. Further, even if there is ink collected in the vicinity of the nozzle, it can be effectively replaced by this configuration. Therefore, in this ink discharge head, even when high-viscosity ink is used, it is difficult to stay in the vicinity of the nozzle 35 and the nozzle 35 is not easily clogged.

  Next, with reference to FIG. 5, a method for manufacturing the ink ejection head according to the present embodiment will be described. FIG. 5 is a partial cross-sectional view illustrating the manufacturing process of the ink ejection head according to the present embodiment. In FIG. 5, only the portions corresponding to the partition walls 20a and the bottom substrate 70 are shown. Further, portions other than the portion shown in FIG. 5 of the ink discharge head according to the present embodiment can be manufactured by the same technique as that of a general ink discharge head. Further, description of contents common to the first embodiment is omitted.

  First, as in the first embodiment, a Cr thin film 110 was formed on the surface of the Si substrate 100 as shown in FIG. 5A, and a pattern 111 was formed as shown in FIG. 5B.

  Next, as shown in FIG. 5C, the groove 102 was formed by etching the surface of the Si substrate 100 in the vertical direction using the pattern 111 as a mask. In the present embodiment, the Bosch process is used as the etching process, but other processes such as deep RIE (Reactive Ion Etching) may be used.

Next, as shown in FIG. 5D, a thin film pattern 112 was formed by implanting Ga ions into the surface of the groove 102 using a focused ion beam (FIB) technique. The FIB conditions were an acceleration voltage of 30 kV and a current of 5 nA. The thin film pattern 112 had a Ga concentration peak value of about 5 × 10 ²⁰ cm ⁻³ . As long as the thin film pattern 111 can mask the surface of the groove | channel 102, another material and a formation method may be sufficient as it.

  Next, as shown in FIG. 5E, the surface of the Si substrate 100 was etched in the vertical direction using the patterns 111 and 112 as a mask. Etching was performed by a Bosch process. The etching depth was 22 μm. However, the etching process and the etching depth can be appropriately determined.

  Next, as shown in FIG. 5F, the pattern 111 was removed with a Cr etching solution. At this time, the thin film pattern 112 can be removed by sputtering with argon ions or the like. However, since the thin film pattern 112 may not be removed, it is not removed in this embodiment. Through the steps described above, the bottom substrate 70 and the partition wall 20a are integrally formed. A parylene thin film having a thickness of about 500 nm was formed on the surfaces of the columnar bodies 51 and 52.

In this embodiment, the diameter of the cross section of the columnar bodies 51 and 52 is 4 μm, and the interval between the columnar bodies 51 and 52 is 7.5 μm.
(Third embodiment)
FIG. 6 is a cross-sectional view of the partition wall 20b and the bottom substrate 70 of the ink ejection head according to the third embodiment of the present invention. The configuration of the ink ejection head according to the present embodiment is the same as that of the ink ejection head according to the first embodiment except for the partition wall 20b.

  The structure of the partition wall 20b according to the present embodiment includes a plurality of columnar columns 53 arranged in a matrix like the first embodiment. Further, the columnar body 53 has a columnar shape, and unlike the first embodiment, the diameter of the cross section is uniform in the longitudinal direction. Unlike the first embodiment, the partition wall 20b has a portion between the columnar body 53 and the bottom substrate 70 where there is no gap at the end of the partition wall 20b on the bottom substrate 70 side.

  Therefore, in the partition wall 20b, ink can pass through the tip portion on the side of the nozzle plate 30 (see FIG. 1) where there is a gap between the columnar bodies 53, but the ink does not pass through the rear end portion on the bottom substrate 70 side. I can't pass. Therefore, the ink passing through the partition wall 20b inevitably passes through the nozzle plate 30 side.

  Due to the configuration of the partition wall 20b described above, in this ink discharge head, the flow rate of ink in the ink chamber 10 during the ink replacement operation is increased near the nozzle 35 (see FIG. 1). Therefore, since the ink stays in the vicinity of the nozzle 35 for a short time, the solvent component does not easily evaporate. Further, even if there is ink collected in the vicinity of the nozzle, it can be effectively replaced by this configuration. Therefore, in this ink discharge head, even when high-viscosity ink is used, it is difficult to stay in the vicinity of the nozzle 35 and the nozzle 35 is not easily clogged.

  Next, with reference to FIG. 7, a method for manufacturing the ink ejection head according to the present embodiment will be described. FIG. 7 is a partial cross-sectional view illustrating the manufacturing process of the ink ejection head according to the present embodiment. The portions other than the portion shown in FIG. 7 of the ink discharge head according to the present embodiment can be manufactured by the same technique as that of a general ink discharge head. Further, description of contents common to the first embodiment is omitted.

  First, as in the first embodiment, a pattern 111 was formed on the surface of the Si substrate 100 as shown in FIG.

  Next, as shown in FIG. 7B, a photoresist pattern 113 was formed so as to cover the pattern 111 in the portion where the partition wall 20b was to be formed.

  Next, as shown in FIG. 7C, the Si substrate 100 was etched using the pattern 113 as a mask to form a groove 102a. Etching was performed by a Bosch process. The etching depth was 10 μm. The etching process and the etching depth can be determined as appropriate.

  Next, as shown in FIG. 7D, the pattern 113 was removed with an organic solvent, and the Si substrate 100 was etched using the pattern 111 as a mask. Etching was performed by a Bosch process. The etching depth was 15 μm. The etching process and the etching depth can be determined as appropriate. Thereby, the columnar bodies 53 masked by the pattern 111 remain, and the ink chambers 10 and the gaps between the columnar bodies 53 are formed.

  Next, as shown in FIG. 7E, the pattern 111 was removed with a Cr etching solution. Thereby, the bottom substrate 70 and the partition wall 20b are integrally formed.

In this embodiment, the diameter of the cross section of the columnar body 53 is 3 μm, and the interval between the columnar bodies 53 is 5 μm.
(Fourth embodiment)
FIG. 8 is a plan view of an ink discharge head according to the fourth embodiment of the present invention. The configuration of the ink ejection head according to the present embodiment is the same as that of the ink ejection head according to the first embodiment, except for the configuration described below.

  In this ink discharge head, the partition 20a according to the second embodiment surrounds each ink chamber 10 for each ink chamber 10, and a communication path 45 is formed between each partition 20a. The communication path 45 is a space that connects the flow path 41 and the flow path 42. The width of the communication path 45 is preferably within a range from several μ to several tens of μm, and in this embodiment, the width is 4 μm.

In the ink ejection head according to the present embodiment, there are a portion with the partition wall 20a and a communication passage 45 without the partition wall 20a as paths when ink passes from the channel 41 to the channel 42 in the ink replacement operation. . In the ink replacement operation, when it is necessary to increase the flow velocity of ink, the load applied to the partition wall 20a increases. However, in the present embodiment, the communication path 45 is provided so that the ink is applied to the partition wall 20a. The load is reduced. The steps described above prevent the partition 20a from being damaged, so that the reliability of the ink ejection head is improved.
(Fifth embodiment)
FIG. 9 is a plan view of an ink ejection head according to the fifth embodiment of the present invention. The configuration of the ink ejection head according to the present embodiment is the same as that of the ink ejection head according to the first embodiment, except for the configuration described below.

  This ink discharge head is provided with a partition wall 15 sandwiched between a bottom substrate 70 and a nozzle plate 30 (see FIG. 1). The partition wall 15 isolates the A region and the B region shown in FIG. Therefore, in this ink discharge head, liquid such as ink does not flow between the A area and the B area. That is, different operations can be performed simultaneously in the A region and the B region.

  For example, while the ink discharge operation is performed in the A region, the cleaning operation can be performed by flowing only the solvent component of the ink in the B region. Similarly, while performing the ink ejection operation in the B region, it is possible to perform the cleaning operation by flowing only the solvent component of the ink in the A region.

  As described above, the ink discharge head according to the present embodiment can perform so-called online recovery in which the internal cleaning operation is performed during the ink discharge operation.

  In the ink ejection head of this embodiment, the area is divided into two areas, the A area and the B area where ink does not flow, but may be divided into three or more areas.

DESCRIPTION OF SYMBOLS 10 Ink chamber 20 Partition 30 Nozzle plate 35 Nozzle 41, 42 Flow path 50 Columnar body 60 Discharge energy generating element 70 Bottom substrate

Claims (9)

A peripheral wall constituting an ink chamber to which ink is supplied includes a first wall portion in which a nozzle for ejecting ink is formed, and a second wall portion configured to allow ink to pass therethrough. An ink discharge head,
The second wall portion is composed of a plurality of columnar bodies extending from a position relatively distant from the first wall portion toward a near side, and the plurality of columnar bodies are formed by the first wall portion. An ink discharge head having different lengths extending toward the first wall so that the ink flow resistance is lower on the side relatively closer to the wall than on the far side. .   The plurality of columnar bodies include a columnar body that extends to the first wall portion and a columnar body that extends halfway toward the first wall portion. Ink ejection head. A peripheral wall constituting an ink chamber to which ink is supplied includes a first wall portion in which a nozzle for ejecting ink is formed, and a second wall portion configured to allow ink to pass therethrough. An ink discharge head,
The second wall portion is composed of a plurality of columnar bodies extending from a position relatively far from the first wall portion toward a side closer to the first wall portion, and the plurality of columnar bodies include the first wall portion. An ink discharge head having a region having no gap between the columnar bodies on a side far from the wall. The columnar body extends so thin toward the near side from a relatively far side with respect to the first wall portion, the ink discharge head according to claim 1 or 3. 5. The ink ejection head according to claim 3, wherein the plurality of columnar bodies have different lengths extending toward the first wall portion. The ink ejection head according to any one of claims 1 to 5 , wherein the ink chamber is arranged between the adjacent flow paths along the flow path. The ink ejection head according to claim 6 , wherein a communication path that communicates the adjacent flow paths is provided between the ink chambers adjacent in the arrangement direction of the ink chambers.   The ink ejection head according to claim 6, wherein the ink ejection head is divided into a plurality of regions along the arrangement direction, and a partition wall through which ink does not pass is provided between the plurality of regions. A peripheral wall constituting an ink chamber to which ink is supplied includes a first wall portion in which a nozzle for ejecting ink is formed, and a second wall portion configured to allow ink to pass therethrough. An ink discharge head,
The second wall portion is composed of a plurality of columnar bodies extending from a position relatively distant from the first wall portion toward a near side, and the plurality of columnar bodies are formed by the first wall portion. The length extending toward the wall portion is different, and the gap formed between the columnar bodies is wider on the side relatively closer to the first wall portion than on the far side. Ink discharge head.

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