JP2006076265A - Inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a difference of degrees of generation of crosstalk between a pressure chamber communicated with an ink passage branch of an end and a pressure chamber communicating with an ink passage branch of the inside, and of discharge performances of ink by suppressing a characteristic difference of backward components of pressure waves propagated between the end ink passage branch and the inside ink passage branch. <P>SOLUTION: In an inkjet recording head 10, a plurality of the ink passage branches 48 branch from an ink passage main stream 46. Buffer passages 54 branch and extend from the ink passage main stream 46 at the outside of the ink passage branches 48 of both ends. By setting the buffer passages 54, similar to the inside ink passage branch 48, the end ink passage branch 48 propagates the backward components of the pressure waves to the passages of both sides set adjacent to each other. Therefore, the characteristic difference of the backward components of the pressure waves between the end ink passage branch 48 and the inside ink passage branch 48 is suppressed, whereby the difference of degrees of generation of crosstalk between the pressure chamber communicating with the end ink passage branch and the pressure chamber communicating with the inside ink passage branch, and of discharge performances of ink is suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording head that supplies ink to pressure chambers in which a plurality of ink flow channel branches branched from an ink flow channel main stream are two-dimensionally arranged.

  In an ink jet recording head in which nozzles and pressure chambers communicating with the nozzles are two-dimensionally arranged, an ink channel that supplies ink to each pressure chamber includes an ink channel main stream that is supplied with ink from an ink tank, and an ink It is composed of a plurality of ink channel tributaries that branch out from the main channel and supply ink to a plurality of pressure chambers that communicate with each other (see, for example, Patent Document 1).

  By the way, when ejecting ink, the pressure wave applied to the pressure chamber by the pressurizing means such as a piezoelectric element is divided into a traveling component that travels to the nozzle side and a backward component that recedes to the ink flow path side. When the backward component fluctuates the pressure in the other pressure chamber, crosstalk occurs in the other pressure chamber, or the ink ejection performance in the other pressure chamber is affected. In the configuration described in Patent Document 1, the retreat component of the pressure wave propagated to each ink flow path tributary propagates to another ink flow path tributary through the ink flow path main flow. Among these, the retreat component of the pressure wave propagated to the ink flow path tributary arranged at the extreme end propagates only toward the ink flow path tributary on one side. For this reason, the characteristics of the pressure wave receding component differ between the inner ink channel tributary that propagates the pressure wave receding component to the ink channel tributaries on both sides, and the ink channel tributary on the end. There is a difference in the degree of occurrence of crosstalk and ink ejection performance between the pressure chamber communicated with the inner ink flow path tributary and the pressure chamber communicated with the end ink flow path tributary.

  In addition, bubbles tend to stagnate at the end of the main flow path of the ink flow path, and the bubbles change the characteristics of the retreat component of the pressure wave propagated to the ink flow path tributary at the end. In addition, when the ink is sucked from the nozzle during maintenance of the ink jet recording head, bubbles accumulated at the end of the main ink flow path may flow into the end ink flow path branch, which may change the ink discharge performance. is there.

  Structure of ink flow path for the purpose of suppressing the crosstalk due to the backward component of the pressure wave generated in the pressure chamber and preventing the flow of bubbles stagnated at the end of the ink flow path into the pressure chamber. Has been devised (see, for example, Patent Document 2).

However, in the configuration of the ink flow path described in Patent Document 2, the backward component of the pressure wave generated in the pressure chamber at the end propagates only to the pressure chamber on one side, as in Patent Document 1, so the pressure chamber at the end. And other pressure chambers have different characteristics of the backward component of the pressure wave, resulting in differences in the degree of occurrence of crosstalk and ink ejection performance. Further, in order to prevent the pressure chamber at the end from being affected by the bubbles stagnated at the end of the ink flow path, it is possible to prevent the bubbles accumulated at the end of the ink flow path from flowing into the end pressure chamber. However, there is a problem that the distance between the end portion of the ink flow path and the pressure chamber at the end must be increased, and the size of the ink jet recording head is increased.
JP 2002-307676 A JP 2000-177119 A

  The present invention has been made in consideration of the above-mentioned fact, and suppresses the difference in the characteristic of the receding component of the pressure wave between the end ink flow path tributary and the inner ink flow path tributary, and communicates with the end ink flow path tributary. The degree of occurrence of crosstalk between the pressure chamber formed and the pressure chamber communicated with the inner ink flow path tributary and the difference in ink ejection performance are suppressed. In addition, the effect of the backward component of the pressure wave propagating to the end ink channel tributary from the bubbles stagnating at the end of the main ink flow channel is reduced, and further, the stagnant bubbles at the end of the main ink channel flow are further reduced. This prevents the ink from flowing into the end ink channel branch.

  The ink jet recording head according to claim 1 is connected to an ink tank that stores ink, extends in one direction, and flows the ink supplied from the ink tank in the one direction, and the ink flow A plurality of ink flow channel tributaries that branch from the main flow and extend in a direction crossing the one direction, and flow the ink flowing in the main flow direction in the direction crossing the one direction. A plurality of pressure chambers communicated with each of the ink flow channel tributaries, and are provided to overlap the pressure chambers and a plurality of pressure chambers filled with ink flowing through the ink flow channel tributaries, and pressurize the ink filled in the pressure chambers. An ink jet recording head comprising a plurality of pressurizing means and a plurality of nozzles that are communicated with each pressure chamber, and that are filled in each pressure chamber and eject ink pressurized by each pressurizing means, A buffer channel for branching out and extending from the main ink channel stream on the outside of the ink channel tributary arranged at the end of the plurality of ink channel tributaries and storing ink; To do.

  In the ink jet recording head according to claim 1, the ink flow path main stream communicated with the ink tank extends in one direction, and the ink stored in the ink tank is supplied to the ink flow path main flow and flows in one direction. . Also, a plurality of ink flow path branches branch from the ink flow path main flow and extend in one direction, that is, a direction intersecting with the direction in which the ink flow path extends, and the ink flowing in the ink flow main flow in one direction Flows into each ink flow path tributary and flows in a direction crossing one direction.

  A plurality of two-dimensionally arranged pressure chambers communicate with each of the ink flow channel tributaries, and ink flowing through each ink flow channel tributary is filled in each pressure chamber. Further, a plurality of pressurizing means are provided to overlap each pressure chamber, and a plurality of nozzles are communicated with each pressure chamber, and the ink filled in each pressure chamber is pressurized by each pressurizing means and It is discharged from the nozzle.

  Here, the buffer channel branches out from the ink channel main stream outside the ink channel branch arranged at the end of the plurality of ink channel branches, and stores the ink. Therefore, the backward component of the pressure wave generated by the pressurizing means in the pressure chamber communicated with the ink flow path tributary disposed at the end propagates from the ink flow path tributary to the main ink flow path, and , And propagates to the ink flow path tributary and the buffer flow path provided inside. That is, the end ink channel tributary, like the inner ink channel tributary, propagates the backward component of the pressure wave to the adjacent channels on both sides, and therefore the end ink channel tributary and the inner ink channel tributary. The difference in the characteristics of the receding component of the pressure wave between the pressure chamber and the pressure chamber communicated with the end ink flow path tributary and the occurrence of crosstalk between the pressure chamber communicated with the inner ink flow path tributary Thus, the difference in ink ejection performance is suppressed.

  Further, by providing the buffer flow path, the total amount of ink in the ink flow path increases, and the compliance of the ink in the ink flow path (an amount indicating the ease of deformation of the object) increases. As a result, the meniscus amplitude of the ink in the pressure chamber when the backward component of the pressure wave acts from the ink flow path tributary to the pressure chamber is reduced, so that the variation in the droplet volume of the ink ejected from the nozzle is reduced. Variation in the printed dot diameter is reduced. In addition, since the bubbles in the ink flow path main stream are close to the buffer flow path side, the influence of the backward component of the pressure wave propagated to the ink flow path tributary at the end from the bubbles in the ink flow path main flow is reduced.

  Further, bubbles accumulated at the end of the ink flow channel main stream can be captured in the buffer flow channel, and the bubbles can be prevented from flowing into the ink flow channel branch at the end, and communicated with the ink flow channel branch at the end. Ink discharge performance of the nozzles can be stabilized. In addition, since air bubbles accumulated at the end of the ink flow path main stream are captured by the buffer flow path, it is not necessary to increase the distance between the end of the ink flow path main stream and the end ink flow path tributary. The recording head can be downsized.

  An ink jet recording head according to a second aspect is the ink jet recording head according to the first aspect, wherein the ink jet recording head includes a dummy nozzle that does not discharge the ink communicated with the buffer flow path.

  In the ink jet recording head according to the second aspect, a dummy nozzle that does not discharge ink is communicated with the buffer flow path. For this reason, when the ink is sucked from the nozzle in the maintenance operation of the ink jet recording head, the air bubbles flowing into the buffer flow path can be sucked and discharged from the nozzle.

  An ink jet recording head according to claim 3 is the ink jet recording head according to claim 1, wherein the ink jet recording head has a dummy pressure chamber communicating the buffer channel and the dummy nozzle, and the buffer channel, The shape of the dummy nozzle and the dummy pressure chamber is the same as the shape of the ink flow path tributary, the nozzle and the pressure chamber, respectively, and the dummy nozzle communicated with each buffer flow path and the arrangement of the dummy pressure chambers, The arrangement is the same as the arrangement of the nozzles and the pressure chambers communicated with each ink flow path tributary.

  In the ink jet recording head according to claim 3, the shape of the buffer flow path, the dummy nozzle, and the dummy pressure chamber that communicates with each other is the same as the shape of the ink flow path branch, the nozzle, and the pressure chamber, The arrangement of the dummy nozzles and dummy pressure chambers communicated with the buffer flow path is the same as the arrangement of the nozzles and pressure chambers communicated with each ink flow path tributary. This suppresses a difference in characteristics between the pressure wave retreat component propagated from the ink flow path main flow to the buffer flow path and the pressure wave retraction component propagated from the ink flow path main flow to the ink flow path tributary. Therefore, it is possible to further suppress the difference in the characteristics of the backward component of the pressure wave between the end ink flow path tributary and the inner ink flow path tributary, and thus the pressure chamber communicated with the end ink flow path tributary and the inner ink flow path tributary. It is possible to further suppress the degree of occurrence of crosstalk with the pressure chamber communicated with the flow channel tributary and the difference in ink ejection performance.

  Since the present invention has the above-described configuration, it is possible to suppress the difference in the characteristic of the backward component of the pressure wave propagated between the end ink flow path tributary and the inner ink flow path tributary, thereby communicating with the end ink flow path tributary. It is possible to suppress the degree of occurrence of crosstalk and the difference in ink ejection performance between the pressure chamber formed and the pressure chamber communicated with the inner ink flow path tributary. In addition, it is possible to reduce the influence of the backward component of the pressure wave propagated to the ink flow path tributary from the bubbles stagnated at the end of the main ink flow path, and further, the bubbles stagnated at the end of the main ink flow path It is possible to prevent the ink from flowing into the end ink channel branch.

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

  As shown in FIGS. 1 and 2, the ink jet recording head 10 includes a vibration plate 12, a pressure chamber plate 14, communication path plates 16, 18, 20, branch plates 22, 24, 26, an air damper plate 28, an air damper chamber plate. 30 and the nozzle plate 32 are laminated | stacked in order.

  On the diaphragm 12, a piezoelectric element group 44 ′ is configured in which the piezoelectric elements 44 are arranged in 10 rows along the longitudinal direction of the head and 3 columns along the short side direction, and two groups along the longitudinal direction of the head. It is arranged. As shown in FIGS. 2 and 3, nozzles 34 are arranged on the nozzle plate 32 corresponding to each piezoelectric element 44 in 10 rows along the longitudinal direction of the head and 3 columns along the short direction. Two nozzle groups 34 'are formed in the longitudinal direction of the head. As shown in FIGS. 3 and 4, a pressure chamber 40 is communicated with each nozzle 34 via a second communication hole 38.

  The pressure chambers 40 are arranged corresponding to each nozzle 34 in 10 rows along the longitudinal direction of the head and in 3 columns along the short direction to constitute a piezoelectric element group 40 '. The piezoelectric element group 40' Are arranged in two groups along the longitudinal direction of the head.

  The pressure chambers 40 constituting the pressure chamber group 40 ′ are communicated with the common ink flow path 42 through the first communication hole 36. As shown in FIGS. 3 to 5, the ink flow path 42 is an ink flow path main stream extending along the short direction of the head (corresponding to one direction in claim 1) at the end portion in the longitudinal direction of the head. 46 and three rows of ink channel tributaries 48 branched from the ink channel main flow 46 and extending along the longitudinal direction of the head (corresponding to the direction intersecting one direction in claim 1). Yes. The ink flow path 42 is provided for each pressure chamber group 40 '.

  An ink supply port 50 is provided in the central portion of the ink channel main flow 46 in the short side direction of the head, and ink stored in an ink tank (not shown) is supplied from the ink supply port 50 to the ink channel main flow 46. It flows in the short direction of the head. Further, the pressure chambers 40 of each row are communicated with the ink flow path tributary 48 via the first communication holes 36, and the ink flowing from the ink flow path main flow 46 to the ink flow path tributary 48 is in the head longitudinal direction. To fill each pressure chamber 40.

  In addition, ink channels branched from the main ink flow channel 46 and extending along the ink channel tributary 48 are formed on both sides of the three rows of ink flow channel tributaries 48, similarly to the nozzle 34 and the pressure chamber 40. The shape and arrangement of nozzles and pressure chambers are formed, which will be described later.

  As shown in FIGS. 2 and 4, ink supply ports 50 are formed at both ends of the vibration plate 12 and the pressure chamber plate 14 in the longitudinal direction. In addition, a pair of ink flow path main flows 46 are formed at both ends in the longitudinal direction of the pressure chamber plate 14 and the communication path plates 16, 18, and 20 and face each other. A plurality of pressure chambers 40 arranged in a two-dimensional manner are formed between a pair of ink flow channel main streams 46 of the pressure chamber plate 14. The first communication path 36 is formed in the communication path plates 16, 18, 20, and the second communication path 38 is formed of the communication path plates 16, 18, 20, the branch plates 22, 24, 26, the air damper plate 28, The air damper chamber plate 30 is formed. Further, as shown in FIGS. 2 and 5, the ink flow path tributary 48 is formed in the tributary plates 22, 24 and 26. The ink channel tributaries 48 are arranged in three rows on one side and the other side in the longitudinal direction of the tributary plates 22, 24, 26.

  As shown in FIGS. 2 and 4, a plurality of partition walls 22A, 24A and 26A separating the ink flow branches 48 of the tributary plates 22, 24 and 26 are provided along the longitudinal direction of the tributary plates 22, 24 and 26. The second communication hole 38 is formed. A plurality of nozzles 34 are formed in the nozzle plate 32 so as to overlap the second communication holes 38. The air damper chamber plate 30 will be described later. Further, the air communication hole 52 is formed in the diaphragm 12 and the like, which will be described later.

  Here, as shown in FIGS. 2, 4, and 5, the buffer flow paths 54 are formed in two rows respectively on one side and the other side of the longitudinal direction of the tributary plates 22, 24, and 26. Each buffer channel 54 extends along the ink channel 48 from the end of the ink channel main flow 46 to the outside of the endmost ink channel tributary 48. That is, the ink supplied to the ink flow path main flow 46 flows into the ink flow path tributary 48 and flows into the buffer flow path 54. The buffer channel 54 has the same shape as the ink channel tributary 48.

  A plurality of dummy pressure chambers 56 are formed in the pressure chamber plate 14. The plurality of dummy pressure chambers 56 are arranged along a row of pressure chambers 40 communicated with the ink flow path branch 48 at the end. The dummy pressure chambers 56 have the same shape as the pressure chambers 40, and the dummy pressure chambers in each row have the same arrangement as the pressure chambers 40 in each row.

  In addition, a plurality of dummy nozzles 58 are formed in the nozzle plate 32. The plurality of dummy nozzles 58 are arranged along the row of nozzles 34 communicated with the pressure chambers 40 in the end row. The shape of the dummy nozzle 58 is the same as the shape of the nozzle 34. The arrangement of the dummy nozzles 58 in each row is the same as the arrangement of the nozzles 32 in each row, and each dummy nozzle 58 and each dummy pressure chamber 56 is the same as each nozzle 34 and each pressure chamber 40. The two communication holes 38 communicate with each other. Each dummy pressure chamber 56 communicates with the buffer flow path 54 through the first communication hole 36 and is filled with ink from the buffer flow path 54. The diaphragm 12 is not provided with the piezoelectric element 44 corresponding to each dummy pressure chamber 56, and the ink filled in each dummy pressure chamber 56 is not ejected from each dummy nozzle 58. Therefore, ink is stored in the buffer flow path 54 and the dummy pressure chamber 56.

  By the way, in the ink jet recording head 10, by selectively applying a voltage to the piezoelectric element 44 and displacing the piezoelectric element 44 and the diaphragm 12, the ink filled in the corresponding pressure chamber 40 is pressurized, and the nozzle 34. Discharge from. At this time, the pressure wave acting on the pressure chamber 40 is divided into a traveling component toward the nozzle 34 and a backward component toward the ink flow path tributary 48. As shown in FIG. 6, the retreat component of the pressure wave propagated to the ink flow path branch 48 at the end is transferred to the ink flow path branch 48 and the buffer flow path 54 that are provided inside via the ink flow path main flow 46. Propagate.

  That is, the end ink channel tributary 48, like the inner ink channel tributary 48, propagates the backward component of the pressure wave to the adjacent channels on both sides. The difference in the characteristics of the receding component of the pressure wave from the ink channel branch 48 is suppressed. As a result, the degree of occurrence of crosstalk between the pressure chamber 40 communicated with the end ink flow path tributary 48 and the pressure chamber 40 communicated with the inner ink flow path tributary and the difference in ink ejection performance are suppressed. The Here, as described above, the shapes of the buffer flow path 54, the dummy nozzle 58, and the dummy pressure chamber 56 are the same as the shapes of the ink flow path tributary 48, the nozzle 34, and the pressure chamber 40, respectively. The arrangement of the dummy nozzles 58 and the dummy pressure chambers 56 communicated with the flow paths 54 is the same as the arrangement of the nozzles 34 and the pressure chambers 40 communicated with each ink flow path tributary 48. For this reason, it is possible to further suppress the difference in characteristics of the backward component of the pressure wave between the end ink channel branch 48 and the inner ink channel branch 48. As a result, the degree of occurrence of crosstalk and the difference in ink ejection performance between the pressure chamber 40 communicated with the end ink flow path branch 48 and the pressure chamber 40 communicated with the inner ink flow path branch 46 are further increased. Can be suppressed.

  Further, by providing the buffer flow path 54, the total amount of ink in the ink flow path 42 increases, and the compliance of the ink in the ink flow path 42 (an amount indicating the ease of deformation of the object) increases. As a result, the meniscus amplitude of the ink in the pressure chamber 40 when the backward component of the pressure wave acts from the ink flow path tributary 48 to the pressure chamber 40 is reduced, so that the variation in the droplet volume of the ink ejected from the nozzle 34 is reduced. As a result, the printed dot diameter variation is reduced.

  Further, as shown in FIG. 6, since the bubbles H in the ink flow path main stream 46 are closer to the buffer flow path 54, the backward component of the pressure wave propagated to the ink flow path tributary 48 is the ink flow path main flow. The influence received from the bubbles H in 46 is reduced.

  Also, the bubbles H accumulated at the end of the ink flow path main flow 46 can be captured in the buffer flow path 54, and the bubbles H can be prevented from flowing into the end ink flow path tributary 48. The ink discharge performance of the pressure chamber 40 communicated with the flow path branch 48 can be stabilized.

  In addition, since the dummy nozzle 58 that does not discharge ink communicates with the buffer flow path 54, the bubbles H that have flowed into the buffer flow path 54 when the ink is sucked from the nozzle 34 in the maintenance operation of the inkjet recording head 10. Can be sucked and discharged from the nozzle 34.

  As described above, in the ink jet recording head 10, by providing the buffer flow path 54, it is possible to suppress the difference in characteristics of the receding component of the pressure wave propagating to each ink flow path tributary 48. However, the retreat component of the pressure wave propagating to each ink flow path tributary 48, which is a factor such as crosstalk, cannot be sufficiently suppressed by itself. In addition, when the number of nozzles 34 that eject ink, the frequency at which ink is ejected, or the appropriate amount of ink to be ejected changes rapidly, the amount of ink in the ink flow path 42 changes abruptly, A pressure wave is generated by the impact action. This pressure wave propagates to other pressure chambers 40 in the same manner as the backward component described above, and changes the ink ejection performance. Therefore, it is necessary to suppress the pressure wave propagating to the ink flow path tributary 48.

  Hereinafter, the air damper chamber 60 that suppresses pressure waves propagating to the ink flow path branch 48 will be described.

  As shown in FIGS. 2 and 7 (sectional view 7-7 in FIG. 1), the air damper plate 28 joined to the tributary plate 26 and the air damper chamber plate 30 sandwiched between the nozzle plates 32 have a longitudinal direction of the head. A plurality of air damper chambers 60 extending along the line are formed. The air damper chamber 60 is arranged in five rows on one side and the other side in the longitudinal direction of the air damper chamber plate 30, each row is separated by a partition wall 30A, and one end side and the other end side in the longitudinal direction are separated by a partition wall 30B. It has been. A second communicating hole 38 is formed in the partition wall 30A along the longitudinal direction of the head.

  Each air damper chamber 60 extends between each ink tributary 48 and each buffer channel 54 and the nozzle plate 32 so as to overlap each ink channel tributary 48 and each buffer channel 54. The end 60 </ b> A on the ink flow path main flow 46 side is refracted to a position where it does not overlap with each ink flow path tributary 48 and each buffer flow path 54. An air communication hole 62 extends linearly from the end 60A of the air damper chamber 60 to the diaphragm 12, and the air damper chamber 60 communicates with the atmosphere. Therefore, the pressure wave propagated to the ink flow path tributary 48 is absorbed and relaxed by the air damper chamber 60.

  Here, between the air damper chamber 60 and the diaphragm 12, an ink flow path branch 48, a buffer flow path 54, a second communication hole 38, a first communication hole 36, a pressure chamber 40, and a dummy pressure chamber 56 are arranged. However, in order to arrange the nozzles 34 with high density, they need to be arranged with high density. Therefore, when the air communication hole 62 is formed at a place where the ink flow path 48, the buffer flow path 54, the second communication hole 38, the first communication hole 36, the pressure chamber 40, and the dummy pressure chamber 56 are intricate, the head The rigidity of the nozzle 34 and the high-density arrangement of the nozzles 34 cannot be compatible.

  Therefore, the air communication hole 62 is connected to the second communication hole 38, the first communication hole 36, the pressure chamber 40, and the dummy pressure chamber 56 that are disposed closest to the ink flow main flow 46 from the end 60 </ b> A of the air damper chamber 60. It extends to the diaphragm 12 through the ink flow main flow 46.

  That is, the end 60A of the air damper chamber 60 is located outside the formation region of the nozzle 34, and the second communication hole 38, the first communication hole 36, and the pressure chamber 40 are provided between the end 60A and the diaphragm 12. The dummy pressure chamber 56 is not provided, and the rigidity between the end portion 60A and the diaphragm 12 is high. For this reason, by extending the atmospheric communication hole 62 from the end portion 60A to the diaphragm 12, the atmospheric communication hole 62 is formed without impairing the rigidity of the head and without hindering the high density of the nozzles 34. be able to.

  Further, since the atmosphere communication hole 62 is extended to the diaphragm 12 instead of the nozzle plate 32, ink does not flow into the air damper chamber 60 from the atmosphere communication hole 62.

  A plurality of atmospheric communication holes 62 are communicated with each air damper chamber 60 separately. That is, instead of forming a large air communication hole that spans a plurality of air damper chambers 60, one air communication hole 62 communicates with each air damper chamber 60, thereby reducing the space of the air gap in the head. Increases the rigidity of the head.

  Further, in the ink jet recording head 10, a pair of ink flow channel main streams 46 are opposed to each other with a plurality of pressure chambers 40 arranged two-dimensionally in between, and the air damper chamber 60 has one ink flow channel main flow. Ink flow branch 48 branched from 46 and ink flow branch 48 branched from the other ink flow main flow 46 are provided separately.

  Here, since the atmosphere communication hole 62 is communicated with the end 60A of the air damper chamber 60 so that the atmosphere communication hole 62 is not formed near the center of the head, the pressure chamber 40 and the dummy pressure chamber 56 are formed at the center of the head. The first communication holes 36 and the second communication holes 38 can be arranged with high density, and the nozzles 34 can be arranged with high density. In addition, the rigidity of the central portion of the head can be improved.

  In addition, the inkjet recording head 10 is provided with three rows of ink flow channels 48 and two rows of buffer channels 54, and five rows of air damper chambers are arranged. Since the atmospheric communication holes 62 are extended from the end portions 60A of the five rows of the air damper chambers 60 to the diaphragm 12, that is, to the upper surface of the head, compared with the case where the atmospheric communication holes 62 are extended to the side surface of the head. The air communication hole 62 can be shortened and the space of the air gap in the head can be reduced. As a result, the rigidity of the head can be improved. In addition, unlike the case where the atmosphere communication hole 62 is extended to the side surface of the head, the lengths of all the air damper chambers 60 can be unified, so that variations in the pressure wave characteristics of all the ink flow path tributaries 48 are reduced. It is possible to suppress the variation in ink ejection characteristics. Furthermore, since the air damper chamber 60 can be provided over the entire length of each ink flow path tributary 48, the damper function of the air damper chamber 60 can be sufficiently secured, and the pressure wave propagating to the ink flow path tributary 48 can be sufficiently relaxed. .

  Next, a second embodiment of the present invention 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 FIGS. 8 and 9, in the ink jet recording head 100, as in the ink jet recording head 10 of the first embodiment, a pair of ink flow channel main streams 46 includes a plurality of pressure chambers 40 arranged two-dimensionally. The air damper chambers 60 are opposed to each other, and the air damper chamber 60 is divided into an ink flow path tributary 48 branched from one ink flow path main stream 46 and an ink flow path tributary 48 branched from the other ink flow path main flow 46. It is provided separately.

  As shown in FIG. 10, the atmospheric communication hole 62 is provided so as to straddle the opposed end portions 60B of the pair of air damper chambers 60 arranged along the longitudinal direction of the head. 62 communicates a pair of air damper chambers 60 to the atmosphere. For this reason, since the space of the air communication hole 62 in the head center portion can be reduced, the nozzles 34 can be arranged with high density in the head center portion, and the rigidity of the head center portion can be improved.

  Further, as shown in FIGS. 8 and 9, in the ink jet recording head 100, three rows of ink flow channels 48 and two rows of buffer channels 54 are branched from each ink flow channel main flow 46, and the air damper chamber 60. Are arranged in five columns. Since the atmosphere communication holes 62 are extended from the end portions 60B of the five rows of air damper chambers 60 to the diaphragm 12, that is, to the upper surface of the head, compared with the case where the atmosphere communication holes 62 are extended to the side surface of the head. The air communication hole 62 can be shortened and the space of the air gap in the head can be reduced. Thereby, the rigidity of the head can be improved. In addition, unlike the case where the atmosphere communication hole 62 is extended to the side surface of the head, the lengths of all the air damper chambers 60 can be unified, so that variations in the pressure wave characteristics of all the ink flow path tributaries 48 are reduced. It is possible to suppress the variation in ink ejection characteristics.

  Further, since the air damper chamber 60 can be provided over the entire length of each ink flow path tributary 48, the damper function of the air damper chamber 60 can be sufficiently secured, and the pressure wave propagating to the ink flow path tributary 48 can be sufficiently absorbed. Can be relaxed.

1 is a perspective view showing an ink jet recording head according to a first embodiment of the present invention. 1 is an exploded perspective view showing an ink jet recording head of a first embodiment of the present invention. 1 is a plan view showing a schematic configuration of an ink jet recording head according to a first embodiment of the present invention. FIG. 4 is a sectional view taken along the line 4-4 in FIG. 1. FIG. 5 is a sectional view taken along line 5-5 in FIG. 1. 1 is a plan view showing a schematic configuration of an ink jet recording head according to a first embodiment of the present invention. It is 7-7 sectional drawing of FIG. It is a perspective view which shows the inkjet recording head of 2nd Embodiment of this invention. It is a disassembled perspective view which shows the inkjet recording head of 2nd Embodiment of this invention. It is a perspective view which shows the positional relationship of the air | atmosphere communicating hole and air damper chamber in the inkjet recording head of 2nd Embodiment of this invention.

Explanation of symbols

10 Inkjet recording head 34 Nozzle 40 Pressure chamber 44 Piezoelectric element (pressurizing means)
46 Ink channel main stream 48 Ink channel tributary 54 Buffer channel 56 Dummy pressure chamber 58 Dummy nozzle 100 Inkjet recording head

Claims (3)

An ink flow path that is communicated with an ink tank that stores ink, extends in one direction, and flows ink supplied from the ink tank in the one direction;
A plurality of ink channel tributaries branched from the ink channel main stream and extending in a direction intersecting the one direction, and flowing ink flowing in the ink channel main stream in a direction intersecting the one direction;
A plurality of pressure chambers that are two-dimensionally arranged and communicated with each of the ink flow path tributaries, and in which the ink flowing through the ink flow path tributaries is filled into the chamber;
A plurality of pressurizing means that are provided to overlap each pressure chamber and pressurize the ink filled in each pressure chamber;
A plurality of nozzles that communicate with each pressure chamber and discharge ink that is filled in each pressure chamber and pressurized by each pressurizing means;
An inkjet recording head comprising:
It has a buffer channel for branching out from the ink channel main stream and extending outside the ink channel tributary arranged at the end of the plurality of ink channel tributaries and storing ink. Inkjet recording head.   The inkjet recording head according to claim 1, further comprising a dummy nozzle that does not discharge ink connected to the buffer flow path. A dummy pressure chamber communicating the buffer flow path and the dummy nozzle;
The shapes of the buffer channel, the dummy nozzle, and the dummy pressure chamber are the same as the shapes of the ink channel branch, the nozzle, and the pressure chamber, respectively, and the dummy nozzle and the dummy communicated with each buffer channel 3. The ink jet recording head according to claim 1, wherein the pressure chambers are arranged in the same arrangement as the nozzles and pressure chambers communicated with the respective ink flow path tributaries.

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