JP2006076264A - Inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form atmosphere communication holes so that the rigidity of a head is prevented from being damaged and a high-density arrangement of nozzles is not hindered in the inkjet recording head where the nozzles and pressure chambers are arranged in two dimensions, an ink passage is constituted of an ink passage main stream to which ink is supplied from an ink tank and a plurality of ink passage branches which branch from the ink passage main stream and supply the ink to each pressure chamber, and an air damper chamber is set extending overlapping with the ink passage branches. <P>SOLUTION: In the inkjet recording head 10, the plurality of ink passage branches 48 branch from the ink passage main stream 46, and the air damper chamber 60 extends overlapping with each ink passage branch 48. The atmosphere communication hole 62 extends from an end 60A of the ink passage main stream 46 side of the air damper chamber 60 to a diaphragm 12 through a first communication hole 36 set adjacent to the ink passage main stream 46, a second communication hole 38 and between the pressure chamber 40 and the ink passage main stream 46. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording head provided with an air damper chamber that extends from a main flow of an ink flow path and absorbs pressure waves propagated to a plurality of ink flow path tributaries that supply ink to two-dimensionally arranged pressure chambers. About.

  In the ink jet recording head, the pressure chamber is selectively pressurized by a pressurizing unit such as a piezoelectric element and ink filled in the pressure chamber is ejected from the nozzle. At this time, the pressure wave acting on the pressure chamber is It is divided into a traveling component that travels to the side and a receding component that recedes to the ink channel side. This backward component propagates to other pressure chambers via the ink flow path, fluctuates the pressure in the other pressure chambers, generates crosstalk, and changes the ink ejection performance.

  In addition, when the number of nozzles for ejecting 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 channel changes abruptly, and the pressure caused by the water hammer effect on the ink channel A wave is generated. This pressure wave propagates to the other pressure chambers in the same manner as the backward component described above, and changes the ink ejection performance. Therefore, unevenness in printing density corresponding to the vibration period of the pressure wave occurs.

  For this reason, it has been devised that an air damper chamber is provided so as to overlap the ink flow path between the ink flow path and the nozzle plate, and the pressure wave propagated to the ink flow path by this air damper chamber is absorbed and relaxed (for example, (See Patent Documents 1 to 3). The air damper chamber functions as a damper by being connected to the atmosphere through the atmosphere communication hole, but in recent years, the nozzles are arranged with high density, and accordingly, the pressure chamber and the ink flow path are also high. Since they are arranged in density, there is a limit to the space in which air communication holes can be formed. In this limited space, it is necessary to form an air communication hole so as not to impair the rigidity of the head.

  In Patent Document 1, an air communication hole extending from the side surface of the head to the air damper chamber is formed. However, as in the ink jet recording head described in Patent Document 2, an ink flow path main stream in which nozzles and pressure chambers are two-dimensionally arranged and an ink flow path is supplied with ink from an ink tank, and this ink flow path main flow When the ink flow path branch and the air damper chambers are arranged in three or more rows, the head of the head passes from the inner air damper chamber. Since the air communication hole cannot be extended linearly to the side surface, the air communication hole becomes longer and the space of the air gap in the head increases, so that the rigidity of the head decreases.

  If the air damper chamber at the end is shorter than the air damper chamber at the inside, the air communication hole can be extended straight to the side of the head, but the damper capacity of the air damper chamber at the end decreases, and the damper There is a risk that it will not be possible to secure the ability. In addition, since the characteristics of the pressure wave of the ink flow path tributary are different between the inner side and the end, the ink ejection characteristics between the ejector connected to the ink flow path tributary at the end and the ejector connected to the inner ink flow path. There will be a difference.

Although it is conceivable to extend the air communication hole from the air damper chamber to the nozzle plate, there is a risk that ink may enter the air damper chamber from the air communication hole, which is not a good idea.
JP-A-9-141856 JP 2002-307676 A JP 2003-11356 A

  The present invention has been made in consideration of the above-described facts. The nozzle and the pressure chamber are two-dimensionally arranged, and the ink flow path is supplied with ink from the ink tank. Ink jet recording heads that are composed of a plurality of ink channel branches that branch and supply ink to each pressure chamber, and that are provided with an air damper chamber that extends over the ink channel branches, impair the rigidity of the head. The air damper chamber is formed with an air communication hole that communicates with the atmosphere, and the damper function of the air damper chamber is secured. Further, the ink is prevented from entering the air damper chamber.

  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 branches that branch off from the main road flow and extend in a direction intersecting the one direction to flow the ink in a direction intersecting the one direction, and the ink flowing through each ink flow branch is filled into the chamber. A plurality of two-dimensionally arranged pressure chambers and a diaphragm constituting a part of the wall surface of each pressure chamber are attached so as to overlap each pressure chamber, and a plurality of pressure chambers that pressurize the ink filled in each pressure chamber. Pressure means, a plurality of nozzles for discharging ink filled in each pressure chamber and pressurized by each pressure means, and each ink flow path between a nozzle plate on which the nozzle is formed and each ink flow path tributary Tributary A plurality of overlapping air damper chambers, the pressure chamber adjacent to the main ink flow path from the end of the main air flow side of the air damper chamber to the diaphragm, and the main ink flow path And an air communication hole that extends through the air and communicates the air damper chamber with the atmosphere.

  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. . In addition, a plurality of ink flow path branches branch from the ink flow path main stream and extend in a direction crossing one direction, and ink flowing in one direction through the ink flow path main flow flows into each ink flow path branch. It flows in a direction that intersects one direction.

  The ink flowing through each ink flow path tributary is filled into a plurality of pressure chambers arranged two-dimensionally. In addition, a plurality of pressurizing means are attached to a diaphragm constituting a part of the wall surface of the pressure chamber so as to overlap each pressure chamber, and ink filled in each pressure chamber is applied by each pressurizing means. Pressure is discharged from each nozzle.

  Also, between the nozzle plate where the nozzle is formed and each ink flow path tributary, an air damper chamber extends over each ink flow path tributary, and an air communication hole extends from the air damper chamber to the diaphragm. The pressure wave propagating to the ink flow path tributary is absorbed and relaxed by the air damper chamber.

  Here, an ink flow path tributary, a pressure chamber, and the like are disposed between the air damper chamber and the diaphragm. However, in order to arrange the nozzles with high density, it is necessary to arrange these with high density. . For this reason, when an air communication hole is formed at a place where an ink flow path tributary, a pressure chamber, or the like is complicated, it is impossible to achieve both the rigidity of the head and the high-density arrangement of the nozzles.

  Therefore, the air communication hole extends from the end of the air damper chamber on the ink flow path main stream side to the diaphragm between the pressure chamber adjacent to the ink flow path main flow and the ink flow path main flow.

  That is, the end of the air damper chamber on the ink flow path main stream side is outside the nozzle formation region, and no pressure chamber is provided between the end and the vibration plate. During the period, the original rigidity is high. For this reason, by extending the atmospheric communication hole from the end portion to the diaphragm, it is possible to form the atmospheric communication hole without impairing the rigidity of the head and without hindering the high density of the nozzles.

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

  An ink jet recording head according to a second aspect is the ink jet recording head according to the first aspect, wherein a plurality of the air communication holes are provided, and the air communication holes communicate with the air damper chambers. .

  In the ink jet recording head according to the second aspect, the plurality of air communication holes communicate with the respective air damper chambers. That is, instead of forming a large air communication hole that spans a plurality of air damper chambers, one air communication hole is connected to each air damper chamber, thereby reducing the gap space in the head and increasing the rigidity of the head. Is increasing.

  An ink jet recording head according to a third aspect is the ink jet recording head according to the first or second aspect, wherein the ink flow path tributaries are provided in three or more rows.

  In the ink jet recording head according to the third aspect, the ink flow path tributaries are provided in three or more rows, and the air damper chambers are arranged in three or more rows. Since the atmospheric communication holes are extended from the end of the ink flow path mainstream side of the three or more rows of the air damper chambers to the diaphragm, that is, to the upper surface of the head, compared with the case where the atmospheric communication holes are extended to the side surface of the head. Thus, the air communication hole can be shortened, the space of the air gap in the head can be reduced, and the rigidity of the head can be improved. Also, unlike the case where the air communication hole is extended to the side surface of the head, the length of all the air damper chambers can be unified, so that variation in the pressure wave characteristics of all the ink flow path tributaries can be suppressed, Variations in ink ejection characteristics can be suppressed. Further, since the air damper chamber can be provided over the entire length of each ink flow path tributary, the damper function of the air damper chamber can be sufficiently secured, and the pressure wave propagating to the ink flow path tributary can be sufficiently relaxed.

  An ink jet recording head according to claim 4 is the ink jet recording head according to any one of claims 1 to 3, wherein a plurality of two-dimensionally arranged pressure chambers are provided to face each other. A pair of the ink flow path main flow is provided, and the air damper chambers are provided separately for the ink flow path tributary branched from one ink flow flow main flow and the ink flow path tributary branched from the other ink flow flow main flow, respectively. It is characterized by that.

  The ink jet recording head according to claim 4, wherein a pair of ink flow channel mainstreams face each other with a plurality of pressure chambers arranged two-dimensionally in between, and the air damper chamber has one ink flow channel mainstream. And an ink flow path branch branched from the other main flow path of the other ink flow path.

  Here, the air communication hole is communicated with the end of the air damper chamber on the main side of the ink flow path so that the air communication hole is not formed near the center of the head, so that the pressure chamber and the first communication are formed in the center of the head. The holes and the second communication holes can be arranged with high density, and the nozzles can be arranged with high density. In addition, the rigidity of the central portion of the head can be improved.

  The ink jet recording head according to claim 5 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 branches that branch off from the main road flow and extend in a direction intersecting the one direction to flow the ink in a direction intersecting the one direction, and the ink flowing through each ink flow branch is filled into the chamber. A plurality of two-dimensionally arranged pressure chambers and a diaphragm constituting a part of the wall surface of the pressure chamber are attached so as to overlap each pressure chamber, and a plurality of pressure chambers that pressurize the ink filled in each pressure chamber. Pressure means, a plurality of nozzles for discharging ink filled in each pressure chamber and pressurized by each pressure means, and each ink flow path between a nozzle plate on which the nozzle is formed and each ink flow path tributary Branch And an air communication hole extending from the air damper chamber to the diaphragm and communicating the air damper chamber with the atmosphere. A pair of the ink flow path main streams facing each other with a plurality of the pressure chambers arranged in between are provided, and the air damper chamber is divided into an ink flow path tributary branching from one ink flow path main stream and the other ink. Provided separately for each ink flow path branch branched from the main flow path, and provided with the air communication hole so as to straddle the ends of the pair of air damper chambers facing each other in the extending direction of the ink flow path branch. It is characterized by that.

  The ink jet recording head according to claim 5, wherein a pair of ink flow channel main streams are opposed to each other with a plurality of pressure chambers arranged two-dimensionally in between, and the air damper chamber has one ink flow channel main flow. And an ink flow path branch branched from the other main flow path of the other ink flow path.

  Here, the atmosphere communication hole is provided so as to straddle the ends of a pair of air damper chambers facing each other in the direction intersecting with one direction, that is, the extending direction of the ink flow path tributary, and one atmosphere communication hole. Communicates a pair of air damper chambers to the atmosphere. For this reason, since the space of the air communication hole in the central portion of the head can be reduced, the nozzles can be arranged densely in the central portion of the head, and the rigidity of the central portion of the head can be improved.

  An ink jet recording head according to a sixth aspect of the invention is the ink jet recording head according to the fifth aspect, wherein three or more rows of the ink flow path branches branched from the main flow of each ink flow path are provided.

  In an ink jet recording head according to a sixth aspect of the present invention, three or more rows of ink flow channels are branched from each main flow of ink channels, and three or more rows of air damper chambers are arranged. Since the air communication holes are extended from the end near the center of the head of the air damper chambers of these three or more rows to the diaphragm, that is, to the upper surface of the head, compared with the case where the air communication holes are extended to the side surface of the head. Thus, the air communication hole can be shortened, the space of the air gap in the head can be reduced, and thus the rigidity of the head can be improved. In addition, unlike the case where the air communication hole is extended to the side surface of the head, the length of all the air damper chambers can be unified, so that variation in the pressure wave characteristics of all the ink flow path tributaries can be suppressed, Variations in ink ejection characteristics can be suppressed. Furthermore, since the air damper chamber can be provided over the entire length of each ink flow path tributary, the damper function of the air damper chamber can be sufficiently secured, and the pressure wave propagating to the ink flow path tributary can be sufficiently relaxed.

  Since the present invention is configured as described above, the nozzles and pressure chambers are two-dimensionally arranged, the ink flow path is supplied from the ink tank, and the ink flow path main stream is branched from the ink flow path main flow to each pressure chamber. In an ink jet recording head having an air damper chamber that is formed by a plurality of ink flow path tributaries that supply ink and that extends over the ink flow path tributaries, the head rigidity is not impaired, and the nozzle An air communication hole that communicates the air damper chamber with the atmosphere can be formed so as not to hinder high density. In addition, the damper function of the air damper chamber can be secured. Furthermore, ink can be prevented from entering the air damper chamber.

  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 lateral 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 flow path tributary 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 flow path tributary 48 and the inner ink flow path tributary 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 branch 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. For this reason, the pressure wave propagated to the ink flow path branch 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.

  Accordingly, the air communication hole 62 is provided with the second communication hole 38, the first communication hole 36, the pressure chamber 40, the dummy pressure chamber 56, and the ink that are disposed closest to the ink flow main flow 46 from the end 60A of the air damper chamber 60. The diaphragm is extended to the diaphragm 12 through the flow path 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, by connecting one air communication hole 62 to each air damper chamber 60 one by one, the space of the gap in the head is reduced, 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 atmosphere communication holes 62 are provided so as to straddle the end portions 60B of the pair of air damper chambers 60 facing in the longitudinal direction of the head, and one atmosphere communication hole 62 is a pair. The air damper chamber 60 communicates with 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.

  In addition, 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. .

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 60 Air damper chamber 62 Air communication hole 100 Inkjet recording head

Claims (6)

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; and
A plurality of ink channel tributaries that branch from the ink channel main stream and extend in a direction intersecting the one direction and flowing ink in a direction intersecting the one direction;
A plurality of two-dimensionally arranged pressure chambers filled with ink flowing through each ink flow path tributary;
A plurality of pressurization means for pressurizing ink filled in each pressure chamber, attached to a vibration plate constituting a part of the wall surface of each pressure chamber so as to overlap each pressure chamber;
A plurality of nozzles for discharging ink filled in each pressure chamber and pressurized by each pressurizing means;
A plurality of air damper chambers extending overlapping each ink flow path tributary between the nozzle plate on which the nozzle is formed and each ink flow path tributary;
The air damper chamber extends from the ink flow channel main stream side end portion to the vibration plate between the pressure chamber adjacent to the ink flow channel main flow and the ink flow channel main flow, and the air damper chamber is An air communication hole communicating with the atmosphere;
An inkjet recording head comprising:   The ink jet recording head according to claim 1, wherein a plurality of the air communication holes are provided, and each air communication hole is communicated with each air damper chamber.   The ink jet recording head according to claim 1, wherein the ink flow path tributary is provided in three or more rows. A pair of the ink flow path mainstreams facing each other with a plurality of the pressure chambers arranged two-dimensionally in between,
4. The air damper chamber according to claim 1, wherein the air damper chamber is provided separately for an ink flow path branch branched from one ink flow path main stream and an ink flow path branch branched from the other ink flow path main flow. The inkjet recording head according to any one of the above. 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; and
A plurality of ink channel tributaries that branch from the ink channel main stream and extend in a direction intersecting the one direction and flowing ink in a direction intersecting the one direction;
A plurality of two-dimensionally arranged pressure chambers filled with ink flowing through each ink flow path tributary;
A plurality of pressurization means for pressurizing ink filled in each pressure chamber, attached to a vibration plate constituting a part of the wall surface of the pressure chamber, and overlapping each pressure chamber;
A plurality of nozzles for discharging ink filled in each pressure chamber and pressurized by each pressurizing means;
A plurality of air damper chambers extending overlapping each ink flow path tributary between the nozzle plate on which the nozzle is formed and each ink flow path tributary;
An air communication hole extending from the air damper chamber to the diaphragm, and communicating the air damper chamber with the atmosphere;
An ink jet recording head provided with
A pair of the ink flow path mainstreams facing each other with a plurality of the pressure chambers arranged two-dimensionally in between,
The air damper chamber is provided separately for an ink flow path tributary branched from one ink flow path main stream and an ink flow path tributary branched from the other ink flow path main flow,
An ink jet recording head, wherein the air communication hole is provided so as to straddle the ends of a pair of the air damper chambers facing each other in the extending direction of the ink flow path tributary.   6. The ink jet recording head according to claim 5, wherein three or more rows of the ink flow path branches branched from the main flow paths of the ink flow paths are provided.

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