Head chip, liquid jet head, and liquid jet recording device

Abstract

A head chip according to one aspect disclosed herein comprises: an actuator plate which is disposed facing a plurality of pressure chambers respectively communicating with a plurality of nozzle holes, and can be deformed to expand or contract the pressure chambers; and a support plate which is laminated on the opposite side of the actuator plate to the pressure chambers. Between the actuator plate and the support plate, a deformation allowing part for allowing deformation of the actuator plate is provided at a portion facing at least a portion of the pressure chambers when viewed from the thickness direction of the actuator plate.

Description

Head Chip, Liquid Jet Head, and Liquid Jet Recording Apparatus

[0001] The present disclosure relates to a head chip, a liquid jet head, and a liquid jet recording apparatus. This application claims priority from Japanese Patent Application No. 2024-166109 filed in Japan on September 25, 2024, the content of which is incorporated herein by reference.

[0002] In a head chip mounted on an inkjet printer, an electric field is generated in an actuator plate formed of a piezoelectric material, and the actuator plate is deformed to cause a pressure fluctuation in a pressure chamber (see Patent Document 1 below). As a result, the ink contained in the pressure chamber is ejected through a nozzle hole.

[0003] Japanese Patent No. 7220327 Gazette

[0004] By the way, in a head chip, in order to eject a desired amount of ink, it is necessary to generate a desired generation pressure (elastic energy) in the pressure chamber when an electric field is generated in the actuator plate. In order to improve the generation pressure in the pressure chamber, it is preferable that the actuator plate deform flexibly with respect to the electric field generated in the actuator plate. On the other hand, in order to perform the processing on the actuator plate with high precision, it is preferable that the actuator plate is difficult to deform with respect to the load applied to the actuator plate during the processing of the pressure chamber.

[0005] The present disclosure provides a head chip, a liquid jet head, and a liquid jet recording apparatus capable of achieving both ensuring the generation pressure in the pressure chamber during ink ejection and improving the processing accuracy for the actuator plate.

[0006] To solve the above problems, the present disclosure adopts the following embodiments: (1) A head tip according to one embodiment of the present disclosure comprises an actuator plate that is arranged facing a plurality of pressure chambers that communicate individually with a plurality of injection holes and is deformable so that the pressure chambers expand or contract, and a support plate laminated on the side of the actuator plate opposite to the pressure chambers, wherein a deformation-allowing portion is provided between the actuator plate and the support plate in the portion facing at least a part of the pressure chambers when viewed from the thickness direction of the actuator plate, which allows deformation of the actuator plate. According to this embodiment, by laminating the support plate on the side of the actuator plate opposite to the pressure chambers, the actuator plate can be supported by the support plate from the side opposite to the pressure chambers when forming a pressure chamber on the side of the actuator plate that faces away from the support plate, or when smoothing the side facing away from the support plate. This improves the machining accuracy of the actuator plate. Furthermore, by providing a deformation-allowing portion on the support plate that faces at least a part of the pressure chambers, the obstruction of the deformation of the actuator plate by the support plate during liquid injection can be reduced. As a result, it is easier to secure the pressure generated in the pressure chambers.

[0007] (2) In the head chip according to the embodiment of (1) above, it is preferable that the actuator plate is deformable in the thickness direction. According to this embodiment, the deformation-allowing portion faces the actuator plate in the deformation direction of the actuator plate. Therefore, the obstruction of the deformation of the actuator plate by the support plate during liquid injection can be further reduced.

[0008] (3) In the head chip according to the embodiment of (2) above, it is preferable that the deformation-allowing portion includes a recess that opens toward the actuator plate in the thickness direction. According to this embodiment, the movable area of ​​the actuator plate is secured, thereby further reducing the obstruction of the deformation of the actuator plate by the support plate.

[0009] (4) In the head chip according to the embodiment of (3) above, it is preferable that the deformation-tolerant portion extends along the outer circumference of the pressure chamber when viewed from the thickness direction. According to this embodiment, it is easier to secure the amount of deformation of the portion of the actuator plate that corresponds to the outer circumference of the pressure chamber which is the starting point of deformation.

[0010] (5) In the head chip according to the embodiment of (4) above, the actuator plate is set with the thickness direction as the polarization direction, and the actuator plate has a first groove that opens toward the opposite side of the support plate in the thickness direction and constitutes at least a part of the pressure chamber, and a second groove that opens toward the support plate in a portion located between adjacent pressure chambers when viewed from the thickness direction, and a first electrode is formed on the inner surface of the first groove, and a second electrode is formed on the inner surface of the second groove that generates an electric field in the portion of the actuator plate located within the first groove and the second groove due to the potential difference generated between the first electrode and the second electrode. According to this embodiment, an electric field is generated in the portion of the actuator plate located within the first groove and the second groove (drive portion) due to the potential difference generated between the first electrode and the second electrode, so the drive portion deforms in the thickness direction of the actuator plate by so-called shear mode. This makes it easier to secure the amount of deformation of the actuator plate and secure the generated pressure in the pressure chamber.

[0011] (6) In the head chip according to the embodiment of (5) above, it is preferable that at least a part of the deformation-tolerant portion overlaps with the portion of the actuator plate located between the first groove and the second groove when viewed from the thickness direction. According to this embodiment, deformation of the drive wall portion during liquid injection is easily tolerated. Therefore, it is possible to further improve the generated pressure.

[0012] (7) In the head tip according to the embodiment of (6) above, it is preferable that the dimensions of the deformation-tolerant portion in the direction of arrangement of the plurality of injection holes are larger than the second groove. According to this embodiment, since one deformation-tolerant portion is arranged to span between adjacent pressure chambers, manufacturing variations can be reduced and yield can be improved.

[0013] (8) In a head chip according to either embodiment of (6) or (7) above, the plurality of injection holes penetrate in the thickness direction, and an injection hole plate is provided on the side opposite to the support plate with respect to the actuator plate, wherein the actuator plate has a first groove formed thereon and a first surface facing the thickness direction with respect to the plurality of pressure chambers, and a second groove formed thereon and facing the opposite side in the thickness direction with respect to the first surface, and comprises an opposing portion provided at a distance in the thickness direction from the injection hole plate, and a partition portion formed integrally with the opposing portion and protruding from the opposing portion in the thickness direction to partition adjacent pressure chambers, wherein the opposing portion includes a drive portion located between adjacent first grooves and second grooves, and it is preferable that at least a part of the partition portion is provided at a position that does not overlap with the drive portion when viewed from the thickness direction. According to this embodiment, an electric field is generated in the drive portion by the potential difference generated between the first electrode formed in the first groove and the second electrode formed in the second groove. As a result, the drive unit deforms in the thickness direction by a so-called shear mode, allowing liquid to be injected through the injection holes. In particular, in this embodiment, at least a portion of the protruding wall is positioned so as not to overlap with the drive unit when viewed from the thickness direction, creating a gap in the thickness direction between the injection hole plate and the drive unit. Therefore, the obstruction of the drive unit's deformation by the injection hole plate, etc., during liquid injection can be reduced. As a result, it is easier to secure the amount of deformation of the actuator plate and the pressure generated in the pressure chamber. Moreover, according to this embodiment, the protruding wall also serves as at least a portion of the partition that separates adjacent pressure chambers. This improves the positional accuracy in the direction intersecting the thickness direction (the arrangement direction of the pressure chambers) between the drive unit and the partition compared to a configuration in which the entire partition is formed from a separate component from the actuator plate.

[0014] (9) In a head chip according to any of the embodiments (1) to (8) above, it is preferable that multiple deformation-allowing portions are provided for each pressure chamber. According to this embodiment, it is easier to improve the degree of design freedom compared to the case in which one deformation-allowing portion is provided for each pressure chamber. In addition, since the actuator plate can be supported by the portion of the support plate located between adjacent deformation-allowing portions, it is easier to improve the machining accuracy.

[0015] (10) A liquid spray head according to one aspect of the present disclosure comprises a head tip according to any of the aspects of (1) to (9) above. According to this aspect, a highly reliable liquid spray head can be provided.

[0016] (11) A liquid jet recording device according to one aspect of the present disclosure is equipped with a liquid jet head according to the aspect of (10) above. According to this aspect, a highly reliable liquid jet recording device can be provided.

[0017] According to one aspect of this disclosure, it is possible to achieve both securing the pressure generated in the pressure chamber during ink ejection and improving the machining accuracy of the actuator plate.

[0018] This is a schematic diagram of the inkjet printer according to the first embodiment. This is a schematic diagram of the inkjet head and ink circulation mechanism according to the first embodiment. This is an exploded perspective view of the ejection unit according to the first embodiment. This is an exploded perspective view of the head chip according to the first embodiment. This is a plan view of the actuator plate according to the first embodiment. This is a cross-sectional view of the head chip corresponding to the line VI-VI in Figure 4. This is a cross-sectional view of the ejection unit corresponding to the line VII-VII in Figure 6. This is a cross-sectional view of the ejection unit corresponding to the line VIII-VIII in Figure 6. This is a bottom view of the support plate according to the first embodiment. This is a plan view of the support plate according to the first embodiment. This is a flowchart for explaining the manufacturing method of the ejection unit according to the first embodiment. This is a cross-sectional view of the process for explaining the first actuator processing step, corresponding to Figure 6. This is a cross-sectional view of the process for explaining the first actuator processing step, corresponding to Figure 6. This is a cross-sectional view of the process for explaining the first support plate processing step, corresponding to Figure 7 joining process, corresponding to Figure 6. This is a process diagram illustrating the second actuator processing step, and is a cross-sectional view corresponding to Figure 6. This is a process diagram illustrating the protective film formation step, and is a cross-sectional view corresponding to Figure 6. This is a cross-sectional view of the head tip according to the second embodiment. This is a cross-sectional view of the head tip according to the third embodiment. This is a cross-sectional view of the head tip according to the fourth embodiment. This is a cross-sectional view of the head tip according to the fifth embodiment. This is a cross-sectional view of the head tip according to the sixth embodiment. This is an enlarged cross-sectional view of the head tip according to the seventh embodiment. This is an enlarged cross-sectional view of the head tip according to the eighth embodiment.

[0019] Embodiments relating to this disclosure will be described below with reference to the drawings. In the embodiments and modifications described below, corresponding components may be denoted by the same reference numerals and their descriptions omitted. In the following description, expressions indicating relative or absolute arrangements such as "parallel," "orthogonal," "center," and "coaxial" will not only strictly represent such arrangements, but also represent states of relative displacement with tolerances or angles and distances that allow the same function to be obtained. In the following embodiments, an inkjet printer (hereinafter simply referred to as "printer") that uses ink (liquid) to record on a recording medium will be used as an example. In the drawings used in the following description, the scale of each component has been appropriately changed in order to make each component recognizable.

[0020] (First Embodiment) [Printer 1] Figure 1 is a schematic diagram of printer 1. The printer (liquid jet recording device) 1 shown in Figure 1 comprises a pair of transport mechanisms 2 and 3, an ink tank 4, an inkjet head (liquid jet head) 5, an ink circulation mechanism 6, and a scanning mechanism 7.

[0021] In the following explanation, the Cartesian coordinate system of X, Y, and Z will be used as needed. In this case, the X direction coincides with the transport direction (sub-scanning direction) of the recording medium P (e.g., paper). The Y direction coincides with the scanning direction (main scanning direction) of the scanning mechanism 7. The Z direction represents the height direction (gravity direction) perpendicular to the X and Y directions. In the following explanation, among the X, Y, and Z directions, the side indicated by the arrow in the figure will be referred to as the positive (+) side, and the side opposite the arrow will be referred to as the negative (-) side. In this specification, the +Z side corresponds to the upward direction of gravity, and the -Z side corresponds to the downward direction of gravity.

[0022] The transport mechanisms 2 and 3 transport the recording medium P to the +X side. Each of the transport mechanisms 2 and 3 includes, for example, a pair of rollers 11 and 12 extending in the Y direction. The ink tank 4 contains, for example, four colors of ink separately: yellow, magenta, cyan, and black. Each inkjet head 5 is configured to eject the four colors of ink (yellow, magenta, cyan, and black) according to the connected ink tank 4.

[0023] Figure 2 is a schematic diagram of the inkjet head 5 and the ink circulation mechanism 6. As shown in Figures 1 and 2, the ink circulation mechanism 6 circulates ink between the ink tank 4 and the inkjet head 5. Specifically, the ink circulation mechanism 6 includes a circulation channel 23 having an ink supply pipe 21 and an ink discharge pipe 22, a pressure pump 24 connected to the ink supply pipe 21, and a suction pump 25 connected to the ink discharge pipe 22.

[0024] The pressurizing pump 24 pressurizes the ink supply pipe 21 and sends ink to the inkjet head 5 through the ink supply pipe 21. As a result, the ink supply pipe 21 side has positive pressure relative to the inkjet head 5. The suction pump 25 depressurizes the ink discharge pipe 22 and sucks ink from the inkjet head 5 through the ink discharge pipe 22. As a result, the ink discharge pipe 22 side has negative pressure relative to the inkjet head 5. Driven by the pressurizing pump 24 and the suction pump 25, the ink can circulate between the inkjet head 5 and the ink tank 4 through the circulation channel 23.

[0025] As shown in Figure 1, the scanning mechanism 7 causes the inkjet head 5 to reciprocate in the Y direction. The scanning mechanism 7 includes a guide rail 28 extending in the Y direction and a carriage 29 movably supported on the guide rail 28.

[0026] <Inkjet Head 5> The inkjet head 5 is mounted on a carriage 29. In the illustrated example, multiple inkjet heads 5 are mounted in a row in the Y direction on a single carriage 29. The inkjet head 5 includes an ejection unit 30 (see Figure 2), an ink supply unit (not shown) connecting the ink circulation mechanism 6 and the ejection unit 30, and a control unit (not shown) that applies a drive voltage to the ejection unit 30.

[0027] [Discharge Unit 30] Figure 3 is an exploded perspective view of the discharge unit 30. The discharge unit 30 shown in Figure 3 is a so-called circulating side-chute type. The circulating side-chute type discharge unit 30 circulates ink with the ink tank 4 and discharges ink from the center of the pressure chamber 50 in the extending direction (Y direction). The discharge unit 30 comprises a flow path frame member 31, a head chip 32, a flow path cover 34, and a flexible printed circuit board 35 (see Figure 7).

[0028] <Flow channel frame member 31> The flow channel frame member 31 is formed in the shape of a rectangular frame with the Z direction as the thickness direction and the X direction as the longitudinal direction. The flow channel frame member 31 separates the chip housing section 31a, the inlet common flow channel 31b, and the outlet common flow channel 31c. The chip housing section 31a, the inlet common flow channel 31b, and the outlet common flow channel 31c are in communication with each other and penetrate the flow channel frame member 31 in the Z direction.

[0029] The chip housing portion 31a is formed in the central part of the flow path frame member 31 in the Y direction. In a plan view, the chip housing portion 31a is formed as an elongated hole with the X direction as its longitudinal direction. The inlet common flow path 31b is formed in the part of the flow path frame member 31 located on the +Y side relative to the chip housing portion 31a. The inlet common flow path 31b is formed as an elongated hole with the X direction as its longitudinal direction, similar to the chip housing portion 31a. The +X side end of the inlet common flow path 31b protrudes in the X direction relative to the chip housing portion 31a. The outlet common flow path 31c is formed in the part of the flow path frame member 31 located on the -Y side relative to the chip housing portion 31a. The outlet common flow path 31c is formed as an elongated hole with the X direction as its longitudinal direction, similar to the inlet common flow path 31b. The -X side end of the outlet common flow path 31c protrudes in the X direction relative to the chip housing portion 31a.

[0030] <Head Chip 32> Figure 4 is an exploded perspective view of the head chip 32. As shown in Figure 4, the head chip 32 has a plurality of pressure chambers 50 in the X direction in which ink is contained, and discharges ink from the pressure chambers 50 through nozzle holes 39a that communicate with each pressure chamber 50 individually, depending on the pressure fluctuations within the pressure chambers 50. The head chip 32 comprises a chip module 37 and a nozzle plate 39.

[0031] As shown in Figure 3, the chip module 37 is formed in a block shape with the Z direction as the thickness direction and the X direction as the longitudinal direction. The chip module 37 is fitted into the chip housing portion 31a. Specifically, the chip module 37 has a thickness in the Z direction that is the same as that of the flow path frame member 31, and its plan view shape is the same as that of the chip housing portion 31a. The +X side end face of the chip module 37 is fixed by adhesive or the like to the inner surface of the chip housing portion 31a that faces the -X side. The -X side end face of the chip module 37 is fixed by adhesive or the like to the inner surface of the chip housing portion 31a that faces the +X side. Therefore, within the flow path frame member 31, the inlet common flow path 31b and the outlet common flow path 31c are blocked by the chip module 37.

[0032] Figure 5 is a plan view of the actuator plate 41. Figure 6 is a cross-sectional view of the head chip 32 corresponding to the line VI-VI in Figure 4. Figure 7 is a cross-sectional view of the discharge unit 30 corresponding to the line VII-VII in Figure 6. Figure 8 is a cross-sectional view of the discharge unit 30 corresponding to the line VIII-VIII in Figure 6. As shown in Figures 4 to 8, the chip module 37 comprises an actuator plate 41, a support plate 42, and an intermediate plate 43. The chip module 37 is constructed by stacking the intermediate plate 43, the actuator plate 41, and the support plate 42 in that order. In the following description, in the Z direction, the direction from the intermediate plate 43 toward the support plate 42 (+Z side) may be described as the upper side, and the direction from the support plate 42 toward the intermediate plate 43 (-Z side) may be described as the lower side. In the first embodiment, the lower surface of the head chip 32 is arranged flush with the lower surface of the flow path frame member 31. The upper surface of the head chip 32 is arranged flush with the upper surface of the flow path frame member 31.

[0033] <Actuator Plate 41> The actuator plate 41 constitutes a part of the pressure chamber 50 and generates pressure fluctuations in the pressure chamber 50 during ink ejection. The actuator plate 41 is made of a piezoelectric material such as PZT (lead zirconate titanate). For example, the actuator plate 41 uses a so-called monopole substrate in which the polarization direction is unidirectional throughout the entire Z-direction. That is, the actuator plate 41 is formed integrally without any bonding interfaces. Alternatively, the actuator plate 41 may use a so-called chevron substrate, which is made by laminating two piezoelectric plates with different polarization directions in the Z-direction.

[0034] The actuator plate 41 comprises an opposing portion 55 and a partition portion 56. The opposing portion 55 is formed in a plate shape with the Z direction as the thickness direction. The opposing portion 55 constitutes the top wall of each pressure chamber 50. That is, the opposing portion 55 is located above all of the pressure chambers 50, straddling the space between them. Each partition portion 56 protrudes downward from the opposing portion 55 and extends parallel to each other along the entire length of the opposing portion 55 in the Y direction. The partition portion 56 separates adjacent pressure chambers 50 in the X direction. That is, the partition portion 56 constitutes the side wall of the pressure chamber 50.

[0035] In the opposing section 55, recesses 57 are formed in the portions located between adjacent partition sections 56 in the X direction. The recesses 57 open on the lower surface of the opposing section 55 and extend linearly along the entire length of the opposing section 55 in the Y direction. The recesses 57 also function as part of the pressure chamber 50.

[0036] As shown in Figure 6, the width in the X direction of the recess 57 is narrower than the distance between adjacent partition portions 56. Furthermore, the recess 57 is located in a position that includes the center in the X direction of the pressure chamber 50 and does not come into contact with the partition portion 56. Therefore, in the cross-sectional view shown in Figure 6, the pressure chamber 50 is formed in a stepped shape in which the width in the X direction of the upper portion is narrower than the width in the X direction of the lower portion. In the first embodiment, the center in the X direction of the recess 57 coincides with the center in the X direction of the pressure chamber 50. The depth in the Z direction of the recess 57 is set to be more than half the thickness in the Z direction of the opposing portion 55 and greater than or equal to the height in the Z direction of the partition portion 56. However, the depth in the Z direction of the recess 57 can be changed as appropriate.

[0037] In the opposing portion 55, a dividing groove 58 is formed in the portion located between adjacent recesses 57 in the X direction. The dividing groove 58 opens on the upper surface of the opposing portion 55 and extends linearly in the Y direction. Therefore, the dividing groove 58 is arranged alternately with the recesses 57 in the X direction (at offset positions when viewed from the Z direction) and extends parallel to the recesses 57 in a plan view. The ends of the dividing groove 58 in the Y direction are not open to the end faces in the Y direction of the opposing portion 55.

[0038] As shown in Figure 6, the width of the dividing groove 58 in the X direction is formed to be less than the distance between adjacent recesses 57. The dividing groove 58 is located in the X direction, including the center of the partition 56, but not in contact with the recesses 57. In the first embodiment, the center of the dividing groove 58 in the X direction coincides with the center of the partition 56 in the X direction, and the width in the X direction is narrower than the width of the partition 56 in the X direction. Therefore, the entire dividing groove 58 overlaps the entire partition 56 in a plan view. The width of the dividing groove 58 may be greater than or equal to the width of the partition 56. Furthermore, the partition 56 and the dividing groove 58 only need to overlap in a plan view, at least in part.

[0039] The depth of the dividing groove 58 in the Z direction is formed to be more than half the thickness of the opposing portion 55 in the Z direction. Therefore, parts of the dividing groove 58 and recess 57 overlap each other when viewed from the X direction (they overlap in the Z direction).

[0040] In the first embodiment, the pressure chamber 50 is surrounded by adjacent partitions 56 and portions of opposing portions 55 located between adjacent partitions 56. The pressure chamber 50 extends linearly in the Y direction along the entire length of the actuator plate 41. The +Y side openings in the pressure chamber 50 are individually connected to the common inlet passage 31b. The -Y side openings in each pressure chamber 50 are individually connected to the common outlet passage 31c. That is, the common inlet passage 31b and the common outlet passage 31c are connected via each pressure chamber 50.

[0041] Of the opposing portion 55, the portion located between adjacent recesses 57 and dividing grooves 58 in the X direction constitutes the drive portion 59. In a cross-sectional view perpendicular to the Y direction, the drive portion 59 has the same thickness as the opposing portion 55. Furthermore, the width of the opposing portion 55 in the X direction is narrower than that of the recesses 57, dividing grooves 58, and partition portion 56. In the illustrated example, the drive portion 59 is positioned so as not to overlap with the entire partition portion 56 in a plan view. However, a part of the drive portion 59 may overlap with the partition portion 56 in a plan view.

[0042] The drive units 59 are provided at positions corresponding to both ends in the X direction of a single pressure chamber 50. In the following description, the drive unit 59 located at the +X end of the pressure chamber 50 may be referred to as the +side drive unit 59a. The drive unit 59 located at the -X end of the pressure chamber 50 may be referred to as the -side drive unit 59b. In the first embodiment, the +X side drive unit 59a of one pressure chamber 50 also functions as the -X side drive unit 59b adjacent to the +X side of the pressure chamber 50. The -X side drive unit 59b of one pressure chamber 50 also functions as the +side drive unit 59a of the pressure chamber 50 adjacent to the -X side of the pressure chamber 50.

[0043] <Support Plate 42>As shown in FIGS. 4 and 6, the support plate 42 ensures the rigidity of the chip module 37. The support plate 42 is laminated on the actuator plate 41 to support the actuator plate 41 from above. The support plate 42 is plate-shaped and formed with an outer shape in plan view equivalent to that of the actuator plate 41. The support plate 42 is fixed to the upper surface of the actuator plate 41 (opposing portion 55) by adhesion or the like. In the illustrated example, the thickness of the support plate 42 is greater than that of the actuator plate 41. However, the thickness of the support plate 42 may be less than that of the actuator plate 41. The support plate 42 can be formed of, for example, metal, metal oxide, glass, resin, ceramics, or the like.

[0044] FIG. 9 is a bottom view of the support plate 42. As shown in FIGS. 6 to 9, a deformation tolerance portion 60 is formed at a position of the support plate 42 that overlaps at least a part of the driving portion 59 in plan view. The deformation tolerance portion 60 is a groove that opens on the lower surface of the support plate 42. In plan view, the deformation tolerance portion 60 linearly extends in the Y direction along the pressure chamber 50 at portions located at both ends (outer peripheral portions) in the X direction of the pressure chamber 50. Specifically, among the deformation tolerance portions 60, the deformation tolerance portion 60 located on the +X side straddles (overlaps in plan view) the entire +X side driving portion 59a corresponding to one pressure chamber 50, the dividing groove 58, and the -X side driving portion 59b corresponding to another pressure chamber 50 adjacent to one pressure chamber 50 in the X direction. Among the deformation tolerance portions 60, the deformation tolerance portion 60 located on the -X side straddles (overlaps in plan view) the entire -X side driving portion 59b corresponding to one pressure chamber 50, the dividing groove 58, and the +X side driving portion 59a corresponding to another pressure chamber 50 adjacent to one pressure chamber 50 in the X direction. Therefore, in the cross-sectional view shown in FIG. 6, the driving portion 59 and the dividing groove 58 do not contact the support plate 42.

[0045] As shown in FIGS. 7 and 8, the length of the deformation allowance portion 60 in the Y direction is shorter than the length of the support plate 42 in the Y direction. That is, both ends of the deformation allowance portion 60 in the Y direction are not open at both end faces of the support plate 42 in the Y direction. In the Y direction, the deformation allowance portion 60 is formed to have the same length as the dividing groove 58. In plan view, the deformation allowance portion 60 overlaps the entire Y direction of the dividing groove 58. Therefore, in the cross-sectional view shown in FIGS. 7 and 8, the driving portion 59 and the dividing groove 58 are not in contact with the support plate 42. However, the dimensions of the deformation allowance portion 60 can be changed as appropriate.

[0046] As shown in FIGS. 4, 7 to 9, a common conduction portion 61 and an individual conduction portion 62 are formed on the support plate 42. The common conduction portion 61 is provided at the +Y side end of the support plate 42. The individual conduction portion 62 is provided at the -Y side end of the support plate 42.

[0047] The common conduction portion 61 is formed in a portion of the support plate 42 that is located on the +Y side with respect to the deformation allowance portion 60. The common conduction portion 61 includes a common recess 65 and a common wiring groove 66. The common recess 65 opens on the upper surface of the support plate 42. The common recess 65 constitutes the upper end opening of the common conduction portion 61. A plurality of common recesses 65 are provided at intervals in the X direction.

[0048] The common wiring groove 66 opens on the lower surface of the support plate 42 and extends linearly in the X direction. That is, the common wiring groove 66 constitutes the lower end opening of the common conduction portion 61. The common wiring groove 66 is provided so as to cross in the X direction between a plurality of common recesses 65. The common wiring groove 66 communicates with each common recess 65 through a portion that overlaps the common recess 65 in plan view. The portion where the common recess 65 and the common wiring groove 66 of the common conduction portion 61 communicate constitutes a common through portion 67 that penetrates the support plate 42 in the Z direction. Note that the common wiring groove 66 is not limited to straddling all the common recesses 65, and it may straddle at least between adjacent common recesses 65.

[0049] The individual conductive portion 62 is formed on the support plate 42, for example, at a position that overlaps in a plan view with the -Y side end of the deformation-allowable portion 60. The individual conductive portion 62 includes an individual recess 70 and an individual wiring groove 71. The individual recess 70 opens on the upper surface of the support plate 42. The individual recess 70 constitutes the upper end opening of the individual conductive portion 62. Multiple individual recesses 70 are provided spaced apart in the X direction. In the first embodiment, the common recess 65 and the individual recesses 70 are arranged at different positions in the Y direction and alternately in the X direction. However, the position of the common recess 65 relative to the individual recesses 70 can be changed as appropriate.

[0050] The individual wiring groove 71 opens on the lower surface of the support plate 42 and extends linearly in the X direction. That is, the individual wiring groove 71 constitutes the lower end opening of the individual conductive portion 62. The individual wiring groove 71 is provided so as to traverse the X direction between the multiple individual recesses 70. The individual wiring groove 71 communicates with each individual recess 70 through a portion that overlaps with the individual recess 70 in a plan view. The portion of the individual conductive portion 62 that communicates with the individual recess 70 and the individual wiring groove 71 constitutes an individual penetration portion 73 that penetrates the support plate 42 in the Z direction. Note that the individual wiring groove 71 is not limited to spanning all individual recesses 70, but only needs to span between at least adjacent individual recesses 70.

[0051] As shown in Figures 4 and 6, the intermediate plate 43 is superimposed on the nozzle plate 39 to reinforce the nozzle plate 39. The intermediate plate 43 covers the lower surface of the actuator plate 41. The intermediate plate 43 is joined to the lower surface of the actuator plate 41 via an adhesive or the like. In this way, the intermediate plate 43 covers the lower end openings of each pressure chamber 50 together. Preferably, the intermediate plate 43 is made of a material with greater rigidity than the nozzle plate 39. However, the intermediate plate 43 may be made of a material with less rigidity than the nozzle plate 39, as long as the rigidity can be ensured together with the nozzle plate 39. In this case, the intermediate plate 43 can be made of a single-layer or laminated structure of resin material, metal material, glass, silicon, etc.

[0052] The intermediate plate 43 has a plurality of communication holes 43a that penetrate the intermediate plate 43 in the Z direction. Each communication hole 43a overlaps individually with respect to each pressure chamber 50 in a plan view. In the first embodiment, each communication hole 43a opens at the center of each pressure chamber 50 in the Y and X directions.

[0053] In the actuator plate 41, the lower end surface of the drive unit 59 is positioned above the lower end surface of the partition 56. That is, the lower end surface of the drive unit 59 is positioned away from the upper surface of the intermediate plate 43 in the Z direction. In this case, the gap 77 formed between the lower surface of the drive unit 59 and the upper surface of the intermediate plate 43 constitutes part of the pressure chamber 50. The gap 77 functions as an adhesive reservoir when the upper surface of the intermediate plate 43 is joined to the actuator plate 41, and as a deformation space for the drive unit 59 during ink ejection.

[0054] <Nozzle Plate 39> The nozzle plate 39 covers the lower surfaces of the chip module 37 and the flow path frame member 31 together. The nozzle plate 39 is joined to the lower surfaces of the intermediate plate 43 and the flow path frame member 31 via adhesive or the like. As a result, the nozzle plate 39 covers the lower end openings of the inlet common flow path 31b and the outlet common flow path 31c, as well as the lower end opening of the communication hole 43a together. The nozzle plate 39 is formed of, for example, a resin material (polyimide, etc.). However, the nozzle plate 39 may be made of a metal material (SUS, Ni-Pd, etc.), glass, silicon, etc., in addition to a resin material.

[0055] The nozzle plate 39 has a plurality of nozzle holes 39a that penetrate the nozzle plate 39 in the Z direction. The nozzle holes 39a are formed in a tapered shape, for example, with the inner diameter gradually decreasing from top to bottom. Each nozzle hole 39a overlaps with each communication hole 43a in a plan view. That is, each nozzle hole 39a communicates separately with the corresponding pressure chamber 50 through the communication hole 43a.

[0056] In the first embodiment, the communication hole 43a only needs to be formed to be at least larger than the nozzle hole 39a. That is, the communication hole 43a may be slightly larger than the nozzle hole 39a, as shown in the illustrated example, or it may be the same shape as the pressure chamber 50.

[0057] Next, the various wirings formed on the head chip 32 will be described. The head chip 32 is equipped with a common wiring 81 and individual wirings 82 as drive wirings. As shown in Figures 6 to 8, the common wiring 81 includes a common electrode 81a, an end-face routing wiring 81b, an upper-face routing wiring 81c, a through-wiring 81d, and a common pad 81e.

[0058] The common electrode 81a is formed on the inner surface of at least each recess 57 on the lower surface of the opposing portion 55. In the illustrated example, the common electrode 81a is formed over the entire inner surface of the recess 57. That is, the entire common electrode 81a faces into the pressure chamber 50.

[0059] The end face routing wiring 81b is formed on the +Y side end face of the opposing portion 55. In the first embodiment, the end face routing wiring 81b is formed over the entire +Y side end face of the opposing portion 55. The end face routing wiring 81b is connected to the common electrode 81a at the boundary between the lower surface of the opposing portion 55 and the +Y side end face. As shown in Figures 4 and 5, the upper surface routing wiring 81c is formed on the +Y side end of the upper surface of the opposing portion 55. The upper surface routing wiring 81c is formed in a strip shape extending in the X direction on the upper surface of the opposing portion 55. The upper surface routing wiring 81c is connected to the end face routing wiring 81b at the boundary between the upper surface of the opposing portion 55 and the +Y side end face. The upper surface routing wiring 81c is separated from the dividing groove 58 in the Y direction.

[0060] As shown in Figure 8, the through-wiring 81d is for connecting the upper surface routing wiring 81c and the common pad 81e. The through-wiring 81d is provided so as to pass through the support plate 42. The through-wiring 81d is formed on the inner surface of the common through-hole 67. The through-wiring 81d is connected to the upper surface routing wiring 81c at the lower end edge of the common through-hole 67. Note that it is sufficient for the through-wiring 81d to have conductivity along the entire length in the Z direction of the inner surface of the common through-hole 67. That is, the through-wiring 81d may be formed over the entire circumferential surface of the inner surface of the common through-hole 67, or it may be formed only on a part of the circumferential surface.

[0061] Figure 10 is a plan view of the support plate 42. As shown in Figures 4 and 10, the common pad 81e is formed on the upper surface of the support plate 42. The common pad 81e is connected to the through wiring 81d at the upper opening edge of the common through portion 67.

[0062] As shown in Figures 4 and 6, the individual wiring 82 includes a first individual electrode 82a, a second individual electrode 82b, a third individual electrode 82c, an upper surface routing wiring 82d, a through wiring 82e, and an individual pad 82f.

[0063] The first individual electrodes 82a are formed on the upper surface of the opposing portion 55 in a portion that overlaps with each pressure chamber 50 in a plan view. In the first embodiment, the first individual electrodes 82a are formed on the upper surface of the opposing portion 55 in a portion that overlaps with the recess 57 in a plan view. Therefore, the first individual electrodes 82a face the common electrode 81a in the Z direction with the opposing portion 55 in between. On the upper surface of the opposing portion 55, the +Y side end of the first individual electrode 82a is separated from the upper surface routing wiring 81c.

[0064] The second individual electrode 82b is formed on the inner surface of the dividing groove 58 (+X side dividing groove 58a) located on the +X side with respect to the pressure chamber 50. The second individual electrode 82b is formed on the inner surface of the +X side dividing groove 58a, extending from the inner surface facing the +X side to the bottom surface. Therefore, the second individual electrode 82b faces the common electrode 81a with the +X side drive unit 59a in between. The third individual electrode 82c is formed on the inner surface of the dividing groove 58 (-X side dividing groove 58b) located on the -X side with respect to the pressure chamber 50. The third individual electrode 82c is formed on the inner surface of the -X side dividing groove 58b, extending from the inner surface facing the -X side to the bottom surface. Therefore, the third individual electrode 82c faces the common electrode 81a with the -X side drive unit 59b in between. The second individual electrode 82b, which corresponds to one pressure chamber 50, and the third individual electrode 82c, which corresponds to another pressure chamber 50 adjacent to the first pressure chamber 50, are separated at the bottom surface of the dividing groove 58.

[0065] The top surface routing wiring 82d connects the first individual electrode 82a, the second individual electrode 82b, and the third individual electrode 82c, which are provided on the upper surface of the opposing portion 55 corresponding to one pressure chamber 50. The top surface routing wiring 82d extends in a strip shape in the X direction from the -Y side end of the upper surface of the opposing portion 55. The top surface routing wiring 82d is connected to the first individual electrode 82a at its center in the X direction. The top surface routing wiring 82d is connected to the second individual electrode 82b at its +X side end. The top surface routing wiring 82d is connected to the third individual electrode 82c at its -X side end.

[0066] The through-wiring 82e is for connecting the upper surface routing wiring 82d and the individual pads 82f. The through-wiring 82e is provided so as to pass through the support plate 42. The through-wiring 82e is formed on the inner surface of the individual through-part 73. The through-wiring 82e is connected to the upper surface routing wiring 82d at the lower end edge of the individual through-part 73. Note that it is sufficient for the through-wiring 82e to be conductive along the entire length in the Z direction on the inner surface of the individual through-part 73. That is, the through-wiring 82e may be formed over the entire circumferential surface of the inner surface of the individual through-part 73, or it may be formed only on a part of the circumferential surface.

[0067] As shown in Figures 4 and 10, the individual pads 82f are formed on the upper surface of the support plate 42. The individual pads 82f are connected to the through-wiring 82e at the upper end opening edge of the individual through-port 73.

[0068] As shown in Figure 6, the actuator plate 41 is provided with a protective film 88 that covers the actuator plate from below. The protective film 88 is provided so as to cover the entire inner surface of the pressure chamber 50 and the lower surface of the partition 56. In this way, the protective film 88 protects the common electrode 81a. The protective film 88 contains an organic insulating material as a material with edge properties, such as a paraxylylene resin material (for example, parylene®). The protective film 88 is made of tantalum oxide (Ta ２ O ５ ), silicon nitride (SiN), silicon carbide (SiC), silicon oxide (SiO ２ ) or diamond-like carbon, etc., and may contain at least one of these.

[0069] <Flow channel cover 34> As shown in Figures 3 and 7, the flow channel cover 34 sandwiches the flow channel frame member 31 and the chip module 37 between itself and the reinforcing plate 38. The flow channel cover 34 comprises a cover base 90, an inlet port 91, and an outlet port 92. The cover base 90 is a rectangular plate with an outer shape in plan view that is the same as that of the flow channel frame member 31. The cover base 90 is superimposed on the upper surfaces of the flow channel frame member 31 and the chip module 37. The cover base 90 is joined to the upper surfaces of the flow channel frame member 31 and the chip module 37 via adhesive or the like, and is fastened to the flow channel frame member 31 with screws or the like. As a result, the cover base 90 closes the upper end openings of the common inlet flow channel 31b and the common outlet flow channel 31c.

[0070] A slit 90a is formed in the central part of the cover base 90 in the Y direction. The slit 90a penetrates the cover base 90 in the Z direction and extends in the X direction. The slit 90a is formed in a position that overlaps with the central part (excluding the outer periphery) of the chip module 37 in a plan view. That is, the Y-direction dimension of the slit 90a is smaller than the Y-direction dimension of the chip module 37. The X-direction dimension of the slit 90a is smaller than the X-direction dimension of the chip module 37. The slit 90a exposes at least a portion of the common pad 81e and the individual pad 82f on the upper surface of the support plate 42.

[0071] The inlet port 91 is located at the +Y and +X end of the cover base 90. The inlet port 91 protrudes upward from the cover base 90. The inlet port 91 communicates with the common inlet channel 31b through the +X end of the common inlet channel 31b (the portion that protrudes relative to the chip housing 31a). In other words, the ink flowing through the ink supply pipe 21 is supplied to the common inlet channel 31b through the inlet port 91. The outlet port 92 is located at the -Y and -X end of the cover base 90. The outlet port 92 protrudes upward from the cover base 90. The outlet port 92 communicates with the common outlet channel 31c through the -X end of the common outlet channel 31c (the portion that protrudes relative to the chip housing 31a). In other words, the ink flowing through the common outlet channel 31c is discharged to the ink discharge pipe 22 through the outlet port 92.

[0072] The flexible printed circuit board 35 is pressed against the upper surface of the support plate 42 through a slit 90a. The flexible printed circuit board 35 is connected to a common pad 81e and individual pads 82f on the upper surface of the support plate 42. After being pulled upward, the flexible printed circuit board 35 is connected to the control unit.

[0073] [Operation Method of Printer 1] Next, the process of recording characters, figures, etc., on the recording medium P using the printer 1 configured as described above will be explained below. Initially, it is assumed that the four ink tanks 4 shown in Figure 1 are each sufficiently filled with ink of a different color. The ink in the ink tanks 4 is filled into the inkjet head 5 via the ink circulation mechanism 6.

[0074] In this initial state, when the printer 1 is activated, the recording medium P is carried to the +X side while being held between the rollers 11 and 12 of the transport mechanisms 2 and 3. Simultaneously with the transport of the recording medium P, the carriage 29 moves in the Y direction, causing the inkjet heads 5 mounted on the carriage 29 to move back and forth in the Y direction. While the inkjet heads 5 move back and forth, ink is ejected from each inkjet head 5 onto the recording medium P as needed. This allows for the recording of characters, images, etc., on the recording medium P.

[0075] The movement of each inkjet head 5 will now be described in detail. In a circulating side-chute type inkjet head 5 like the first embodiment, ink is first circulated through the circulation channel 23 by operating the pressure pump 24 and suction pump 25 shown in Figure 2. In this case, the ink circulating in the ink supply pipe 21 is supplied to the common inlet channel 31b through the inlet port 91. The ink supplied to the common inlet channel 31b is distributed to each pressure chamber 50 through the +Y side opening in each pressure chamber 50, and then circulates through each pressure chamber 50 to the -Y side. After that, the ink is discharged to the common outlet channel 31c through the -Y side opening of each pressure chamber 50. The ink discharged to the common outlet channel 31c flows into the ink discharge pipe 22 through the outlet port 92 and is returned to the ink tank 4. This allows ink to be circulated between the inkjet head 5 and the ink tank 4.

[0076] When the reciprocating movement of the inkjet head 5 begins due to the movement of the carriage 29 (see Figure 1), a drive voltage is applied between the common electrode 81a and the individual electrodes 82a to 82c via the flexible printed circuit board 35. At this time, the common electrode 81a is set to the reference potential GND, and the individual electrodes 82a to 82c are set to the drive potential Vdd when the drive voltage is applied. As a result, a potential difference is generated between the common electrode 81a and the individual electrodes 82a to 82c, which are facing each other across the opposing portion 55, and an electric field is generated in the opposing portion 55.

[0077] Specifically, a potential difference is generated in the Z direction between the common electrode 81a and the first individual electrode 82a. Due to the potential difference generated in the Z direction, an electric field is generated in the opposing portion 55 in a direction parallel to the polarization direction (Z direction). As a result, the actuator plate 41 expands and contracts in the Z direction due to the bend mode. A potential difference is generated in the X direction between the common electrode 81a and the second individual electrode 82b, and between the common electrode 81a and the third individual electrode 82c. Due to the potential difference generated in the X direction, an electric field is generated in the drive unit 59, causing the drive unit 59 to undergo thickness sliding deformation in the Z direction due to the shear mode. As a result, the portions of the opposing portion 55 corresponding to each pressure chamber 50 undergo shear deformation upward from both ends in the X direction towards the center. In other words, in the head chip 32 of the first embodiment, the deformation caused by the shear mode and bend mode of the actuator plate 41 extends in the Z direction. Specifically, when a drive voltage is applied, the actuator plate 41 (opposing portion 55) deforms in a direction away from the pressure chamber 50. This increases the volume inside the pressure chamber 50.

[0078] Subsequently, when the drive voltage is reduced to zero, the opposing part 55 returns to its original state, causing the volume inside the pressure chamber 50 to return to its original state. During the process of the actuator plate 41 returning to its original state, the pressure inside the pressure chamber 50 increases, and the ink inside the pressure chamber 50 is ejected to the outside through the communication hole 43a and the nozzle hole 39a. The ink ejected to the outside lands on the recording medium P, and the printed information is recorded on the recording medium P.

[0079] <Manufacturing Method of Discharge Unit 30> Next, the manufacturing method of the discharge unit 30 described above will be explained. Figure 11 is a flowchart illustrating the manufacturing method of the discharge unit 30. As shown in Figure 11, the manufacturing method of the discharge unit 30 includes an actuator first processing step S11, a support plate first processing step S12, a first joining step S13, an actuator second processing step S14, a support plate second processing step S15, a protective film formation step S16, a second joining step S17, an assembly step S18, and a third joining step S19. For convenience, the following explanation will use the case where the chip module 37 is manufactured at the chip level as an example.

[0080] Figures 12 and 13 are process diagrams illustrating the first actuator machining process S11, and are cross-sectional views corresponding to Figure 6. In the first actuator machining process S11, as shown in Figure 12, a dividing groove 58 is formed in the actuator plate 41 (dividing groove formation process). Specifically, the dividing groove 58 is formed by dicing or the like on the upper surface of the actuator plate 41.

[0081] Next, in the first actuator processing step S11, as shown in Figure 13, the portion of the drive wiring located on the upper surface of the actuator plate 41 (individual electrodes 82a to 82c and upper surface routing wiring 81c, 82d, etc.) is formed (first wiring formation step). In the first wiring formation step, first, a mask pattern with openings for the drive wiring formation area is formed on the upper surface of the actuator plate 41. Next, electrode material is deposited on the actuator plate 41 by, for example, oblique deposition. The electrode material is deposited on the actuator plate 41 through the openings in the mask pattern. As a result, drive wiring is formed on the upper surface of the actuator plate 41 and on the inner surface of the dividing groove 58. After that, by irradiating the bottom surface of the dividing groove 58 with laser light, the second individual electrode 82b corresponding to one pressure chamber 50 and the third individual electrode 82c corresponding to the other pressure chamber 50 adjacent to the first pressure chamber 50 are separated at the bottom surface of the dividing groove 58.

[0082] Figures 14 to 16 are process diagrams illustrating the first processing step S12 of the support plate, and are cross-sectional views corresponding to Figure 7. As shown in Figure 14, in the support plate processing step S12, conductive portions 61 and 62 are first formed on the support plate 42. Specifically, a common recess 65 and individual recesses 70 are formed on the upper surface of the support plate 42 by sandblasting or the like. Subsequently, as shown in Figure 15, a common wiring groove 66 and individual wiring grooves 71 are formed on the lower surface of the support plate 42 by dicing or the like. At this time, the common wiring groove 66 and the common recesses 65 are in communication with each other, and the individual wiring grooves 71 and individual recesses 70 are in communication with each other. This forms the conductive portions 61 and 62.

[0083] Next, in the first processing step S12 of the support plate, a deformation-tolerant portion 60 is formed as shown in Figure 16. The deformation-tolerant portion 60 is formed on the lower surface of the support plate 42 by dicing or the like.

[0084] Figure 17 is a process diagram illustrating the first joining process S13, and is a cross-sectional view corresponding to Figure 6. As shown in Figure 17, in the first joining process S13, the support plate 42 is attached to the upper surface of the actuator plate 41 with adhesive or the like. In the first joining process S13, any excess adhesive that is pushed out when the actuator plate 41 and the support plate 42 are pressed together is contained in the common wiring groove 66, the individual wiring groove 71, and the deformation tolerance section 60.

[0085] Figure 18 is a process diagram illustrating the second actuator processing step S14, and is a cross-sectional view corresponding to Figure 6. In the second actuator processing step S14, as shown in Figure 18, a groove with a width corresponding to the recess 57 is formed on the lower surface of the actuator plate 41 by dicing or the like. Subsequently, the portion of the drive wiring located on the lower surface of the actuator plate 41 and the +Y side end face (common electrode 81a, end face routing wiring 81b, etc.) is formed (second wiring formation step). After that, the portion of the pressure chamber 50 corresponding to the space between adjacent partitions 56 is formed by dicing or the like on the lower surface of the actuator plate 41.

[0086] In the second actuator processing step S14, grinding or other processes are performed as appropriate to smooth the lower surface of the actuator plate 41. At this time, since the support plate 42 is stacked on the upper surface of the actuator plate 41, the lower surface of the actuator plate 41 is ground while being supported by the support plate 42.

[0087] In the second support plate processing step S15, through-wirings 81d, 82e and pads 81e, 82f of the drive wiring are formed on the support plate 42 (third wiring formation step). Specifically, a mask pattern is formed on the upper surface of the support plate 42, with openings for the formation areas of the through-wirings 81d, 82e and pads 81e, 82f. Next, electrode material is deposited on the support plate 42 by oblique deposition from the Y direction, for example. The electrode material is deposited on the support plate 42 through the openings in the mask pattern. This forms the through-wirings 81d, 82e and pads 81e, 82f.

[0088] Figure 19 is a process diagram illustrating the protective film formation process S16, and is a cross-sectional view corresponding to Figure 6. In the protective film formation process S16, as shown in Figure 19, a protective film 88 is formed on the lower surface of the actuator plate 41.

[0089] In the second joining step S17, the intermediate plate 43 is attached to the lower surface of the actuator plate 41 using an adhesive or the like. With this, the chip module 37 is completed.

[0090] In assembly step S18, the chip module 37 is assembled to the flow path frame member 31. Specifically, the chip module 37 is fitted into the chip housing portion 31a so that the lower surface of the flow path frame member 31 and the lower surface of the chip module 37 are flush with each other.

[0091] In the third joining step S19, the nozzle plate 39 is attached so as to cover both the lower surface of the flow path frame member 31 and the lower surface of the chip module 37. Then, the flow path cover 34 is attached to the upper surface of the flow path frame member 31. With these steps, the discharge unit 30 is completed.

[0092] As described above, the head tip 32 of the first embodiment is arranged facing a plurality of pressure chambers 50 that communicate individually with a plurality of nozzle holes (injection holes) 39a, and includes an actuator plate 41 that can be deformed so that the pressure chambers 50 expand or contract, and a support plate 42 stacked on the side of the actuator plate 41 opposite to the pressure chambers 50. Between the actuator plate 41 and the support plate 42, a deformation-allowing portion 60 is provided in the portion that faces at least a part of the pressure chambers 50 when viewed from the Z direction (thickness direction) to allow deformation of the actuator plate 41. With this configuration, since the support plate 42 is stacked on the side of the actuator plate 41 opposite to the pressure chambers 50, the actuator plate 41 can be supported by the support plate 42 from the side opposite to the pressure chambers 50 when forming the pressure chambers 50 etc. on the lower surface of the actuator plate 41 or when smoothing the lower surface of the actuator plate 41. This makes it possible to improve the machining accuracy of the actuator plate 41. Furthermore, by providing a deformation-allowing portion 60 in the support plate 42 that faces at least a part of the pressure chamber 50, the obstruction of the deformation of the actuator plate 41 by the support plate 42 during ink ejection can be reduced. As a result, it becomes easier to secure the pressure generated in the pressure chamber 50.

[0093] In the head chip 32 of the first embodiment, the actuator plate 41 is deformable in the Z direction. With this configuration, the deformation-allowing portion 60 faces the actuator plate 41 in the direction of deformation of the actuator plate 41. Therefore, the obstruction of the deformation of the actuator plate 41 by the support plate 42 during ink ejection can be further reduced.

[0094] In the head chip 32 of the first embodiment, the deformation-allowing portion 60 is a recess that opens toward the actuator plate 41 in the Z direction. With this configuration, the movable range of the actuator plate 41 is secured, thereby further reducing the obstruction of the deformation of the actuator plate 41 by the support plate 42.

[0095] In the head chip 32 of the first embodiment, the deformation-tolerant portion 60 extends along the outer circumference of the pressure chamber 50 when viewed from the Z direction. With this configuration, it is easy to secure the amount of deformation in the portion of the actuator plate 41 that corresponds to the outer circumference of the pressure chamber 50, which is the starting point of the deformation.

[0096] In the head chip 32 of the first embodiment, the actuator plate 41 is set with the Z direction as the polarization direction. The actuator plate 41 has a recess (first groove) 57 that constitutes at least a part of the pressure chamber 50, and a dividing groove (second groove) 58 that opens toward the support plate 42 in the portion located between adjacent pressure chambers 50 when viewed from the Z direction. A common electrode (first electrode) 81a is formed on the inner surface of the recess 57. Individual electrodes (second electrodes) 82b and 82c are formed on the inner surface of the dividing groove 58, which generate an electric field in the actuator plate 41 due to the potential difference generated between them and the common electrode 81a. With this configuration, an electric field is generated in the portion of the actuator plate 41 located between the recess 57 and the dividing groove 58 (drive unit 59) due to the potential difference generated between the common electrode 81a and the individual electrodes 82b and 82c. As a result, the drive unit 59 deforms in the Z direction by a so-called shear mode. This ensures sufficient deformation of the actuator plate 41 and makes it easier to secure the pressure generated in the pressure chamber 50.

[0097] In the head chip 32 of the first embodiment, at least a portion of the deformation-tolerant portion 60 overlaps with the portion of the actuator plate 41 located between the dividing groove 58 and the recess 57 when viewed from the Z direction. This configuration makes it easier to tolerate deformation of the drive unit 59 during ink ejection. Therefore, it is possible to further improve the generated pressure.

[0098] In the head chip 32 of the first embodiment, the width of the deformation-tolerant portion 60 in the X direction is wider than the dividing groove 58. With this configuration, one deformation-tolerant portion 60 is arranged to span between adjacent pressure chambers 50, thereby reducing manufacturing variations and improving yield.

[0099] The head tip 32 of the first embodiment includes a nozzle plate (injection hole plate) 39 in which a nozzle hole 39a is formed. The actuator plate 41 has a lower surface (first surface) in which a recess 57 is formed and an upper surface (second surface) in which a dividing groove 58 is formed, and includes an opposing portion 55 provided at a distance in the Z direction from the nozzle plate 39, and a partition portion 56 formed integrally with the opposing portion 55 and protruding from the opposing portion 55 in the Z direction, partitioning between adjacent pressure chambers 50. The opposing portion 55, located between adjacent recesses 57 and dividing grooves 58, includes a drive unit 59 in which an electric field is generated by a common electrode 81a and individual electrodes 82b, 82c. At least a part of the partition portion 56 is provided in a position that does not overlap with the drive unit 59 when viewed from the Z direction. With this configuration, since at least a part of the partition portion 56 is provided in a position that does not overlap with the drive unit 59 when viewed from the Z direction, a gap is created in the Z direction between the nozzle plate 39 and the drive unit 59. Therefore, the deformation of the drive unit 59 during ink ejection is less likely to be hindered by the nozzle plate 39, etc. As a result, it is easier to secure the amount of deformation of the actuator plate 41 and secure the pressure generated in the pressure chamber 50. Moreover, with the above configuration, since the partition 56 partitions adjacent pressure chambers 50, the positional accuracy of the drive unit 59 and the partition 56 in the X direction can be improved compared to a configuration in which the entire partition is formed from a separate component from the actuator plate 41.

[0100] In the head chip 32 of the first embodiment, multiple deformation-allowing portions 60 are provided for each pressure chamber 50. This configuration makes it easier to improve the degree of design freedom compared to the case where one deformation-allowing portion 60 is provided for each pressure chamber 50. In addition, since the actuator plate 41 can be supported by the portion of the support plate 42 located between adjacent deformation-allowing portions 60, it is easier to improve machining accuracy.

[0101] Since the inkjet head 5 and printer 1 of the first embodiment are equipped with the head chip 32 described above, a highly reliable inkjet head 5 and printer 1 can be provided.

[0102] (Second Embodiment) Figure 20 is a cross-sectional view of the head tip 32 according to the second embodiment. The second embodiment differs from the first embodiment in that the actuator plate 41 does not have a partition portion 56. In the head tip 32 shown in Figure 20, a flow path plate 200 is provided between the actuator plate 41 and the nozzle plate 39. The flow path plate 200 is joined to the lower surface of the actuator plate 41 via adhesive or the like. A plurality of individual flow paths 201 are formed in the flow path plate 200. Each individual flow path 201, together with a corresponding recess 57, constitutes a pressure chamber 50. The individual flow paths 201 penetrate the flow path plate 200 in the Y and Z directions and are provided at intervals in the X direction. The portion of the flow path plate 200 located between adjacent pressure chambers 50 functions as a partition portion 202 that separates the adjacent pressure chambers 50.

[0103] In the cross-sectional view shown in Figure 20, the individual channel 201 is formed in a stepped shape where the width in the X direction at the upper part is wider than the width in the X direction at the lower part. The lower end opening of each individual channel 201 communicates with the corresponding nozzle hole 39a. Note that the width in the X direction of the individual channel 201 may be uniform throughout the entire Z direction.

[0104] With this configuration, the actuator plate 41 can be made thinner by forming the partition portion 202 of the pressure chamber 50 with a flow path plate 200 that is separate from the actuator plate 41. This makes it easier to ensure the amount of deformation of the actuator plate 41 caused by the electric field generated on the actuator plate 41.

[0105] (Third Embodiment) Figure 21 is a cross-sectional view of the head chip 32 according to the third embodiment. The third embodiment differs from the embodiments described above in that a common electrode is formed on the upper surface of the actuator plate 41, and a common electrode and individual electrodes are formed on the lower surface of the actuator plate 41. In the head chip 32 shown in Figure 21, the common wiring 81 includes a first common electrode 210a, a second common electrode 210b, and a third common electrode 210c.

[0106] The first common electrode 210a is formed on the lower surface of the actuator plate 41, in a position that overlaps with each partition portion 202 in a plan view. The second common electrode 210b is positioned on the upper surface of the actuator plate 41, in a position that overlaps with the corresponding pressure chamber 50 in a plan view, but does not overlap with the first common electrode 210a in a plan view. The third common electrode 210c is formed over the entire inner surface of each dividing groove 58. That is, the third common electrode 210c is positioned on both sides in the X direction relative to the second common electrode 210b.

[0107] Regarding the individual wiring 82, the individual electrodes 211 are formed across the inner surface of the recess 57.

[0108] In this configuration, a potential difference is generated in the X direction between the first common electrode 210a and the individual electrodes 211, and between the individual electrodes 211 and the third common electrode 210c. Due to the potential difference generated in the X direction, the actuator plate 41 undergoes thickness sliding deformation in the Z direction due to shear mode. As a result, the portions of the actuator plate 41 corresponding to each pressure chamber 50 undergo shear deformation upward from both ends in the X direction towards the center. On the other hand, a potential difference is generated in the Z direction between the individual electrodes 211 and the second common electrode 210b. Due to the potential difference generated in the Z direction, an electric field is generated in the actuator plate 41 in a direction parallel to the polarization direction (Z direction). As a result, the actuator plate 41 undergoes expansion and contraction deformation in the Z direction due to bend mode. That is, in the head tip 32 of the third embodiment, the deformation caused by both shear mode and bend mode of the actuator plate 41 extends in the Z direction. As a result, the ink in the pressure chamber 50 is ejected to the outside through the nozzle hole 39a.

[0109] (Fourth Embodiment) Figure 22 is a cross-sectional view of the head chip 32 according to the fourth embodiment. In the embodiments described above, a configuration was described in which the deformation-allowing portion 60 is formed to span the +X side drive portion 59a, the dividing groove 58, and the -X side drive portion 59b, which corresponds to the other pressure chamber 50 adjacent to the pressure chamber 50, but the configuration is not limited to this. In the head chip 32 shown in Figure 22, the deformation-allowing portion 60 is formed at a position that overlaps with the pressure chamber 50 in a plan view, and at a position that overlaps with each drive portion 59.

[0110] (Fifth Embodiment) Figure 23 is a cross-sectional view of the head tip 32 according to the fifth embodiment. In the embodiments described above, the deformation-allowing portion 60 has been described as opening on the lower surface of the support plate 42, but the embodiment is not limited to this configuration. In the head tip 32 shown in Figure 23, the support plate 42 has a recess 220 that opens upward. The deformation-allowing portion 60 is a thin-walled portion of the support plate 42 that remains in a position that overlaps with the recess 220 in a plan view. The deformation-allowing portion 60 is a region of the support plate 42 that is more easily deformed than other parts. In the fifth embodiment, the deformation-allowing portion 60 (recess 220) located on the +X side is formed in a position that spans the +X side drive unit 59a, the dividing groove 58, which corresponds to one pressure chamber 50, and the -X side drive unit 59b which corresponds to another pressure chamber 50 adjacent to one pressure chamber 50. Of the deformation-allowing portions 60, the deformation-allowing portion 60 (recess 220) located on the -X side is formed in a position that spans the -X side drive portion 59b, the dividing groove 58, which corresponds to one pressure chamber 50, and the +X side drive portion 59a, which corresponds to another pressure chamber 50 adjacent to the one pressure chamber 50.

[0111] In this configuration, when the actuator plate 41 deforms in the Z direction due to the application of voltage to the drive wiring, the deformation-allowing portion 60 deforms together with the actuator plate 41. This ensures the thickness of the support plate 42 while suppressing the support plate 42 from hindering the deformation of the actuator plate 41.

[0112] In the fifth embodiment described above, a configuration was described in which the deformation-tolerant portion 60 is formed by forming a recess 220 in the support plate 42, but the configuration is not limited to this. For example, as shown in Figure 24, a cavity 221 may be formed in the support plate 42, and the portion of the support plate 42 that overlaps with the cavity 221 in a plan view may function as the deformation-tolerant portion 60. Alternatively, the deformation-tolerant portion 60 may be formed by extending the support plate 42 through in the Z direction.

[0113] (Sixth Embodiment) Figure 25 is a cross-sectional view of the head chip 32 according to the sixth embodiment. In the embodiments described above, a configuration in which a deformation-allowing portion 60 is formed on the support plate 42 itself has been described, but the embodiment is not limited to this configuration. In the head chip 32 shown in Figure 25, an elastically deformable film (deformation-allowing portion) 240 is provided between the actuator plate 41 and the support plate 42. The film 240 is made of a material with a lower elastic modulus than the support plate 42 (for example, a resin material).

[0114] In this configuration, when the actuator plate 41 deforms in the Z direction due to the application of voltage to the drive wiring, the film 240 deforms together with the actuator plate 41. This ensures the thickness of the support plate 42 while suppressing the support plate 42 from hindering the deformation of the actuator plate 41.

[0115] (Seventh Embodiment) Figure 26 is an enlarged cross-sectional view of the head chip 32 according to the seventh embodiment. In the head chip 32 shown in Figure 26, an adhesive layer 250 is interposed between the actuator plate 41 and the support plate 42. The adhesive layer 250 is interposed over the entire area between the actuator plate 41 and the support plate 42, joining the actuator plate 41 and the support plate 42. The adhesive layer 250 is divided into a first portion (deformation-allowing portion) 250a and a second portion 250b on a plane intersecting in the Z direction.

[0116] The first portion 250a functions as a deformation-tolerant portion. The first portion 250a is formed to span, for example, the entire +X side drive portion 59a, the dividing groove 58, and the -X side drive portion 59b, which corresponds to the other pressure chamber 50 adjacent to the first pressure chamber 50, in the X direction. In this embodiment, the first portion 250a is formed of an adhesive material (silicone-based, fluorine-based) that is softer than the second portion 250b.

[0117] The second portion 250b is the portion of the adhesive layer 250 other than the first portion 250a. The second portion 250b is formed of, for example, an epoxy adhesive.

[0118] In this configuration, when the actuator plate 41 deforms in the Z direction due to the application of voltage to the drive wiring, the first portion 250a deforms together with the actuator plate 41. This ensures the thickness of the support plate 42 while suppressing the obstruction of the deformation of the actuator plate 41 by the support plate 42. In the seventh embodiment, a configuration in which the adhesive layer 250 is divided into a first portion 250a and a second portion 250b was described, but the configuration is not limited to this. The adhesive layer 250 may be formed entirely of a relatively soft material.

[0119] (Eighth Embodiment) Figure 27 is a cross-sectional view of the head tip 32 according to the eighth embodiment. The eighth embodiment differs from the embodiments described above in that it employs a so-called edge chute type head tip 32. The head tip 300 shown in Figure 27 comprises an actuator plate 301, a cover plate 302, a support plate 303, and a nozzle plate 304.

[0120] Similar to the first embodiment described above, the actuator plate 301 has a plurality of pressure chambers 50 arranged in the X direction. In this embodiment, the pressure chambers 50 are open at the -Z side end on the lower surface of the actuator plate 301 and closed at the +Z side end.

[0121] The cover plate 302 is stacked on the actuator plate 301 on the +Y side. A common ink chamber 302a is formed in the cover plate 302 at a position that overlaps with the upper part of the pressure chamber 50 when viewed from the Y direction. The common ink chamber 302a extends in the X direction with a length that spans, for example, multiple pressure chambers 50, and opens on the surface of the cover plate 302 facing the +Y side. Slits 302b are formed in the cover plate 302 at positions that overlap with each pressure chamber 50 when viewed from the Y direction. The slits 302b connect the common ink chamber 302a to each pressure chamber 50 individually.

[0122] The support plate 303 is stacked on the actuator plate 301 on the -Y side. On the surface of the support plate 303 facing the +Y side, a deformation-allowing portion 303a is formed, similar to the first embodiment.

[0123] The nozzle plate 304 covers the lower surfaces of the actuator plate 301, the cover plate 302, and the support plate 303. In the portion of the nozzle plate 304 that overlaps with the pressure chamber 50 in a plan view, a nozzle hole 304a is formed.

[0124] In this configuration, the ink in the common ink chamber 302a flows into the pressure chamber 50 through the slit 302b. The ink in the pressure chamber 50 is ejected to the outside through the nozzle hole 304a due to pressure fluctuations within the pressure chamber 50 caused by the application of the drive voltage.

[0125] (Other Modifications) The scope of the present disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the disclosure. For example, in the embodiments described above, an inkjet printer 1 was used as an example of a liquid jet recording device, but it is not limited to a printer. For example, it may be a fax machine or an on-demand printer. In the embodiments described above, a configuration in which the inkjet head moves relative to the recording medium during printing (a so-called shuttle machine) was used as an example, but it is not limited to this configuration. The configuration according to the disclosure may also be adopted in a configuration in which the recording medium is moved relative to the inkjet head while the inkjet head is fixed (a so-called fixed-head machine). In the embodiments described above, the case in which the recording medium P is paper was described, but it is not limited to this configuration. The recording medium P is not limited to paper, but may be a metal material, a resin material, or food, etc. In the embodiments described above, a configuration in which the liquid jet head is mounted on a liquid jet recording device was described, but it is not limited to this configuration. In other words, the liquid sprayed from the liquid spray head is not limited to liquids that are to be sprayed onto the recording medium, but may also be, for example, a drug solution mixed in during compounding, food additives such as seasonings and flavorings added to food, or a fragrance sprayed into the air.

[0126] In the embodiments described above, a configuration in which the Z direction coincides with the direction of gravity was described, but the configuration is not limited to this, and the Z direction may be aligned with the horizontal direction. In the embodiments described above, a configuration in which a dividing groove 58 and a recess 57 are formed in the actuator plate 41 was described, but the configuration is not limited to this. In each of the embodiments described above, a configuration in which the pressure chamber 50 is formed as a groove that linearly penetrates the chip module 37 in the Y direction was described, but the configuration is not limited to this. The pressure chamber 50 can be appropriately changed, for example, to a circular shape in plan view. For example, even when the pressure chamber 50 is formed in a circular shape, it is preferable that the deformation-tolerant portion extends along the outer circumference of the pressure chamber 50 in plan view.

[0127] In the embodiments described above, a configuration was described in which the deformation-allowing portion extends continuously in the Y direction along the pressure chamber 50, but the configuration is not limited to this. The deformation-allowing portion may be provided intermittently in the Y direction. In the embodiments described above, a configuration was described in which the actuator plate 41 is deformed by both the bend mode and the shear mode, but the configuration is not limited to this. The actuator plate 41 only needs to be deformed in at least one of the bend mode and the shear mode. In the embodiments described above, a configuration was described in which adjacent pressure chambers 50 are partitioned by either the partition portion 56 of the actuator plate 41 or the partition portion 202 of the flow path plate 200, but the configuration is not limited to this. Adjacent pressure chambers 50 may be partitioned by both the partition portion 56 of the actuator plate 41 and the partition portion 202 of the flow path plate 200.

[0128] Furthermore, it is possible to replace the components in the embodiments described above with well-known components as appropriate, without departing from the spirit of this disclosure, and the modifications described above may be combined as appropriate.

[0129] 1: Printer (liquid jet recording device) 5: Inkjet head (liquid jet head) 32: Head chip 39: Nozzle plate (jet hole plate) 39a: Nozzle hole (jet hole) 41: Actuator plate 42: Support plate 50: Pressure chamber 55: Opposing part 56: Partition part 57: Recess (first groove) 58: Dividing groove (second groove) 58a: +X side dividing groove (second groove) 58b: -X side dividing groove (second groove) 59: Drive unit 59a: +X side drive unit (drive unit) 59b: -X side drive unit (drive unit) 81a: Common electrode (first electrode) 82a: First individual electrode (second electrode) 82b: Second individual electrode (second electrode) 82c: Third individual electrode (second electrode) 60: Deformation tolerance part 211: Individual electrode (first electrode) 210c: Third common electrode (second electrode) 240: Film (deformation-allowable portion) 250a: First portion (deformation-allowable portion) 300: Head tip 301: Actuator plate 303: Support plate 303a: Deformation-allowable portion 304: Nozzle plate (injection hole plate)

Claims

1. A head tip comprising: an actuator plate arranged facing a plurality of pressure chambers, each communicating with a plurality of injection holes, and deformable so as to expand or contract the pressure chambers; and a support plate stacked on the side of the actuator plate opposite to the pressure chambers, wherein a deformation-allowing portion is provided between the actuator plate and the support plate, in a portion facing at least a part of the pressure chambers when viewed from the thickness direction of the actuator plate, to allow deformation of the actuator plate.

2. The head tip according to claim 1, wherein the actuator plate is deformable in the thickness direction.

3. The head tip according to claim 2, wherein the deformation-tolerant portion includes a recess that opens toward the actuator plate in the thickness direction.

4. The head tip according to claim 3, wherein the deformation-tolerant portion extends along the outer circumference of the pressure chamber when viewed in the thickness direction.

5. The actuator plate is set with the thickness direction as the polarization direction, and the actuator plate has a first groove that opens toward the opposite side of the support plate in the thickness direction and constitutes at least a part of the pressure chamber, and a second groove that opens toward the support plate in a portion located between adjacent pressure chambers when viewed from the thickness direction, and a first electrode is formed on the inner surface of the first groove, and a second electrode is formed on the inner surface of the second groove that generates an electric field in the portion of the actuator plate located within the first groove and the second groove due to the potential difference generated between it and the first electrode.

6. The head tip according to claim 5, wherein at least a portion of the deformation-tolerant portion overlaps with a portion of the actuator plate located between the first groove and the second groove when viewed from the thickness direction.

7. The head tip according to claim 6, wherein the dimensions of the deformation-tolerant portion in the direction of the arrangement of the plurality of injection holes are larger than the dimensions of the second groove.

8. The head tip according to claim 6 or 7, wherein the plurality of injection holes penetrate in the thickness direction, and an injection hole plate is provided on the side of the actuator plate opposite to the support plate, the actuator plate having a first groove formed thereon and a first surface facing the plurality of pressure chambers in the thickness direction, and a second groove formed thereon and a second surface facing the opposite side of the thickness direction to the first surface, and provided at a distance from the injection hole plate in the thickness direction, and a partition portion formed integrally with the opposing portion and protruding from the opposing portion in the thickness direction, partitioning adjacent pressure chambers, the part of the opposing portion located between adjacent first grooves and second grooves includes a drive portion where an electric field is generated by the first electrode and the second electrode, and at least a part of the partition portion is provided at a position that does not overlap with the drive portion when viewed from the thickness direction.

9. The head tip according to any one of claims 1 to 7, wherein a plurality of deformation-allowing portions are provided for each pressure chamber.

10. A liquid spray head comprising the head tip described in any one of claims 1 to 7.

11. A liquid injection recording device comprising the liquid injection head described in claim 10.

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