HEAD CHIP, LIQUID JET HEAD AND LIQUID JET RECORDING APPARATUS

Abstract

A head chip, a liquid jet head, and a liquid jet recording apparatus capable of suppressing short circuits between a common electrode and an individual electrode are provided. [Solution] A head chip according to one aspect of the present disclosure includes an actuator plate having a lower surface facing a plurality of pressure chambers in which liquid is contained and an upper surface facing the opposite side of the pressure chambers relative to the lower surface in the thickness direction, with a recess formed on at least one of a first surface and a second surface, a common electrode provided on the first surface and functioning as a reference potential, and an individual electrode provided on a surface other than the first surface, the second surface, which generates a potential difference between the common electrode and an individual electrode to generate an electric field in the actuator plate. Of the common electrode and the individual electrode, one of the electrodes formed on one surface is formed on at least the inner surface of the recess.

Description

[Technical field]

[0001] The present disclosure relates to a head chip, a liquid jet head, and a liquid jet recording apparatus. [Background technology]

[0002] In the head chip mounted on an inkjet printer, an electric field is generated in an actuator plate made of a piezoelectric material, which deforms the actuator plate and generates pressure fluctuations in the pressure chambers, causing the ink contained in the pressure chambers to be ejected through the nozzle holes.

[0003] For example, Patent Document 1 below discloses a configuration in which an actuator plate and a nozzle plate are arranged facing each other and a pressure chamber is formed between the actuator plate and the nozzle plate. A common electrode and individual electrodes are formed on the lower surface of the actuator plate (the surface facing the pressure chamber). The common electrode and the individual electrodes are prevented from coming into contact with the ink in the pressure chamber by a protective film (film, insulating layer, etc.) that covers the lower surface of the actuator plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7220327 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even if a protective film is provided as in the conventional technology, there is a possibility that discontinuities will occur in the protective film (for example, cracks in the film, or film formation defects in the protective layer, etc.). In this case, ink may get into the gap between the protective film and the lower surface of the actuator plate through the discontinuous areas, which may cause a short circuit between the common electrode and the individual electrodes.

[0006] The present disclosure provides a head chip, a liquid jet head, and a liquid jet recording apparatus that can suppress short circuits between a common electrode and an individual electrode. [Means for solving the problem]

[0007] In order to solve the above problems, the present disclosure employs the following aspects. (1) A head chip according to one embodiment of the present disclosure comprises an actuator plate having a first surface facing a plurality of pressure chambers in which liquid is contained, and a second surface facing the opposite side of the pressure chambers relative to the first surface in a thickness direction, with a recess formed on at least one of the first and second surfaces, a common electrode provided on the first surface and functioning as a reference potential, and an individual electrode provided on a surface other than the first surface, the individual electrode generating a potential difference between the common electrode and an individual electrode, and generating an electric field in the actuator plate, wherein one of the common electrode and the individual electrode formed on the one surface is formed on at least an inner surface of the recess.

[0008] According to this aspect, since the actuator plate has a recess, it is easy to ensure the rigidity of the actuator plate as a whole. Therefore, it is possible to improve manufacturing efficiency and yield. Furthermore, in this aspect, since one of the electrodes is also formed in the recess, it is possible to ensure the surface area of ​​one of the electrodes and it is easy to ensure the opposing area of ​​the first electrode and the second electrode. Therefore, it is easy to improve the pressure generated in the pressure chamber during liquid ejection. In particular, in this embodiment, the individual electrodes are formed on the second surface other than the first surface, so that only the common electrode is formed on the first surface. Therefore, compared to a configuration in which the common electrode and the individual electrodes are provided on the first surface, short-circuiting between the common electrode and the individual electrodes via a liquid can be suppressed. This makes it possible to provide a head chip with excellent durability and reliability.

[0009] (2) In the head chip relating to the above aspect (1), it is preferable that the thickness direction of the actuator plate is set as the polarization direction, the recesses are formed on each of the first surface and the second surface, a first recess formed on the first surface is disposed in a portion facing the pressure chamber as viewed from the thickness direction, and a second recess formed on the second surface is disposed in a position offset from the first recess as viewed from the thickness direction. According to this aspect, an electric field is generated in the portion (driving portion) of the actuator plate located in the first and second recesses due to a potential difference generated between the common electrode formed in the first recess and the individual electrode formed in the second recess. This causes the driving portion to deform in the thickness direction of the actuator plate due to a so-called shear mode. As a result, the amount of deformation of the actuator plate is ensured, and it is easy to ensure the pressure generated in the pressure chamber.

[0010] (3) In the head chip according to any one of aspects (2) above, it is preferable that the individual electrodes are formed on the second surface in a portion other than the second recess. According to this aspect, by generating a potential difference between the individual electrodes formed on the second surface other than the second recess and the common electrode, an electric field can be generated in the thickness direction (polarization direction) of the actuator plate. This allows the actuator plate to deform in the thickness direction in a bend mode (bimorph type). This allows the generated pressure to be further improved.

[0011] (4) In the head chip according to any one of the above aspects (1) to (3), the common electrode may be formed over the entire first surface. According to this aspect, since patterning of the common electrode and the like is not required on the first surface of the actuator plate, it is possible to improve manufacturing efficiency and reduce costs.

[0012] (5) In the head chip according to any one of the above aspects (1) to (4), it is preferable that the actuator plate is integrally formed with the thickness direction as a polarization direction. According to this aspect, by using a so-called monopole actuator plate in which the polarization direction is set in one direction, unlike, for example, a case in which an actuator plate is formed by stacking a plurality of piezoelectric materials with different polarization directions, there is no joint surface between the piezoelectric materials. Therefore, it is possible to prevent liquid from bridging between the common electrode and the individual electrodes through the joint interface in the actuator plate. As a result, the possibility of a short circuit can be reduced.

[0013] (6) In the head chip according to any one of aspects (1) to (5) above, it is preferable that the actuator plate is provided with a protective film covering the common electrode on the first surface. According to this aspect, by covering the common electrode with the protective film, it is possible to prevent the common electrode from coming into contact with liquid, and improve the durability of the common electrode.

[0014] (7) In a head chip according to any one of the above aspects (1) to (6), a jet hole plate is provided facing the actuator plate in the thickness direction, with a plurality of jet holes respectively communicating with the plurality of pressure chambers penetrating in the thickness direction, the actuator plate having the first surface and the second surface, and comprising: an opposing portion provided apart from the jet hole plate in the thickness direction; and a partition portion formed integrally with the opposing portion, protruding from the opposing portion in the thickness direction, and separating adjacent ones of the pressure chambers; and among the recesses, a partition portion formed on the first surface It is preferable that a first recess formed on the second surface is positioned in a portion facing the pressure chamber as viewed in the thickness direction, a second recess formed on the second surface of the recesses is positioned at a position offset from the first recess as viewed in the thickness direction, the common electrode is formed on an inner surface of the first recess, and the individual electrodes are formed on an inner surface of the second recess, the opposing portion includes a driving portion in which an electric field is generated by the common electrode and the individual electrode in a portion located between the first recess and the second recess adjacent to each other, and at least a portion of the partition portion is provided in a position that does not overlap with the driving portion as viewed in the thickness direction. According to this aspect, an electric field is generated in the driving section due to a potential difference generated between the common electrode formed in the first recess and the individual electrode formed in the second recess, which causes the driving section to deform in the thickness direction in a so-called shear mode, thereby enabling the liquid to be ejected through the ejection hole. In particular, in this embodiment, at least a part of the partition is provided at a position that does not overlap with the driving part when viewed in the thickness direction, so that a gap is generated in the thickness direction between the injection hole plate and the driving part. This reduces the inhibition of deformation of the driving part by the injection hole plate or the like when ejecting liquid. As a result, it is easy to ensure the amount of deformation of the actuator plate and the pressure generated in the pressure chamber. Moreover, according to this aspect, the partition also serves as at least a part of the partition that separates the adjacent pressure chambers, which makes it possible to improve the positional accuracy of the drive section and the partition in the direction intersecting the thickness direction (the arrangement direction of the pressure chambers) compared to a configuration in which the partition is entirely made of a separate material from the actuator plate.

[0015] (8) A liquid jet head according to one aspect of the present disclosure includes the head chip according to any one of the above aspects (1) to (7). According to this aspect, it is possible to provide a liquid jet head with excellent reliability.

[0016] (9) A liquid jet recording apparatus according to an aspect of the present disclosure includes the liquid jet head according to the aspect (8) above. According to this aspect, it is possible to provide a highly reliable liquid jet recording apparatus. Effect of the Invention

[0017] According to one aspect of the present disclosure, short circuits between the common electrode and the individual electrodes can be suppressed. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic configuration diagram of an inkjet printer according to a first embodiment. [Diagram 2] FIG. 2 is a schematic configuration diagram of an inkjet head and an ink circulation mechanism according to the first embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of the discharge unit according to the first embodiment. [Figure 4] FIG. 2 is an exploded perspective view of the head chip according to the first embodiment. [Diagram 5] FIG. 2 is a plan view of the actuator plate according to the first embodiment. [Figure 6] 6 is a cross-sectional view of the head chip taken along line VI-VI in FIG. [Figure 7] 7 is a cross-sectional view of the discharge unit taken along line VII-VII in FIG. 6. [Figure 8]8 is a cross-sectional view of the discharge unit taken along line VIII-VIII in FIG. 6. [Figure 9] FIG. 4 is a bottom view of the support plate according to the first embodiment. [Figure 10] FIG. 2 is a plan view of the support plate according to the first embodiment. [Figure 11] 5 is a flowchart for explaining a manufacturing method of the discharge unit according to the first embodiment. [Figure 12] FIG. 7 is a process drawing for explaining a first actuator processing step, and is a cross-sectional view corresponding to FIG. 6. [Figure 13] FIG. 7 is a process drawing for explaining a first actuator processing step, and is a cross-sectional view corresponding to FIG. 6. [Figure 14] FIG. 8 is a process diagram for explaining a first processing step of the support plate, and is a cross-sectional view corresponding to FIG. 7. [Figure 15] FIG. 8 is a process diagram for explaining a first processing step of the support plate, and is a cross-sectional view corresponding to FIG. 7. [Figure 16] FIG. 8 is a process diagram for explaining a first processing step of the support plate, and is a cross-sectional view corresponding to FIG. 7. [Figure 17] FIG. 7 is a process diagram for explaining a first bonding step, and is a cross-sectional view corresponding to FIG. 6. [Figure 18] FIG. 7 is a process drawing for explaining a second actuator processing step, and is a cross-sectional view corresponding to FIG. 6. [Figure 19] FIG. 7 is a process diagram for explaining a protective film forming step, and is a cross-sectional view corresponding to FIG. [Figure 20] FIG. 11 is a cross-sectional view of a head chip according to a second embodiment. [Figure 21] FIG. 11 is a cross-sectional view of a head chip according to a third embodiment. [Figure 22] FIG. 11 is a cross-sectional view of a head chip according to a fourth embodiment. [Diagram 23] FIG. 13 is a cross-sectional view of a head chip according to a fifth embodiment. [Figure 24] FIG. 13 is a cross-sectional view of a head chip according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. In the embodiments and modified examples described below, the same reference numerals may be used to designate corresponding configurations, and the description may be omitted. In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," not only strictly indicate such arrangements, but also indicate a state in which the components are relatively displaced with a tolerance or an angle or distance to the extent that the same function is obtained. In the following embodiment, an inkjet printer (hereinafter, simply referred to as a printer) that uses ink (liquid) to record on a recording medium will be taken as an example for description. In the drawings used in the following description, the scale of each component has been appropriately changed so that each component can be recognized.

[0020] (First embodiment) [Printer 1] FIG. 1 is a schematic diagram of a printer 1. A printer (liquid jet recording apparatus) 1 shown in FIG. 1 includes 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 .

[0021] In the following explanation, an X, Y, Z Cartesian coordinate system is used as necessary. In this case, the X direction coincides with the transport direction (sub-scanning direction) of the recording medium P (e.g., paper, etc.). The Y direction coincides with the scanning direction (main scanning direction) of the scanning mechanism 7. The Z direction indicates the height direction (gravity direction) perpendicular to the X and Y directions. In the following explanation, the X, Y, and Z directions will be explained with the arrows on the figures as the plus (+) side and the opposite side to the arrows as the minus (-) 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. The transport mechanisms 2 and 3 each include a pair of rollers 11 and 12 extending in the Y direction, for example. The ink tanks 4 each contain ink of four colors, for example, yellow, magenta, cyan, and black. Each inkjet head 5 is configured to be capable of ejecting ink of one of the four colors, yellow, magenta, cyan, or black, according to the ink tank 4 connected thereto.

[0023] FIG. 2 is a schematic diagram of the ink-jet head 5 and the ink circulation mechanism 6. As shown in FIG. 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 flow path 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 pressure pump 24 applies pressure to the inside of 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 relative to the inkjet head 5 is under positive pressure. The suction pump 25 reduces the pressure inside the ink discharge tube 22 and sucks ink from the inkjet head 5 through the ink discharge tube 22. This creates a negative pressure on the ink discharge tube 22 side relative to the inkjet head 5. By driving the pressure pump 24 and the suction pump 25, the ink can be circulated between the inkjet head 5 and the ink tank 4 through the circulation flow path 23.

[0025] 1, the scanning mechanism 7 causes the inkjet head 5 to scan back and forth in the Y direction. The scanning mechanism 7 includes a guide rail 28 extending in the Y direction, and a carriage 29 movably supported by the guide rail 28.

[0026] <Inkjet head 5> The inkjet head 5 is mounted on a carriage 29. In the illustrated example, a plurality of inkjet heads 5 are mounted side by side in the Y direction on one carriage 29. The inkjet head 5 includes a discharge unit 30 (see FIG. 2), an ink supply unit (not shown) that connects the ink circulation mechanism 6 and the discharge unit 30, and a control unit (not shown) that applies a drive voltage to the discharge unit 30.

[0027] (First embodiment) [Discharge unit 30] FIG. 3 is an exploded perspective view of the discharge unit 30. As shown in FIG. 3 is a so-called circulation type side chute type discharge unit 30 that circulates ink between the ink tank 4 and discharges ink from the center of the pressure chamber 50 in the extension direction (Y direction). The discharge unit 30 includes a flow path frame member 31, a head chip 32, a flow path cover 34, and a flexible printed circuit board 35 (see FIG. 7).

[0028] <Flow path frame member 31> The flow path frame member 31 is formed in a rectangular frame shape with the thickness direction being the Z direction and the longitudinal direction being the X direction. The flow path frame member 31 defines a chip accommodating section 31a, an inlet common flow path 31b, and an outlet common flow path 31c. The chip accommodating section 31a, the inlet common flow path 31b, and the outlet common flow path 31c penetrate the flow path frame member 31 in the Z direction while communicating with each other.

[0029] The chip accommodating portion 31a is formed in the center in the Y direction of the flow path frame member 31. The chip accommodating portion 31a is formed in an elongated hole shape with the X direction as the longitudinal direction in a plan view. The inlet common flow channel 31b is formed in a portion of the flow channel frame member 31 that is located on the +Y side with respect to the chip accommodating portion 31a. The inlet common flow channel 31b is formed in an elongated hole shape with the X direction as the longitudinal direction, similar to the chip accommodating portion 31a. The +X side end of the inlet common flow channel 31b protrudes in the X direction with respect to the chip accommodating portion 31a. The outlet common flow channel 31c is formed in a portion of the flow channel frame member 31 that is located on the -Y side with respect to the chip storage section 31a. The outlet common flow channel 31c is formed in an elongated hole shape with the X direction as the longitudinal direction, similar to the inlet common flow channel 31b. The -X side end of the outlet common flow channel 31c protrudes in the X direction with respect to the chip storage section 31a.

[0030] <Head chip 32> FIG. 4 is an exploded perspective view of the head chip 32. As shown in FIG. 4, the head chip 32 has a plurality of pressure chambers 50 in the X direction in which ink is stored, and ejects ink from the pressure chambers 50 through nozzle holes 39a that are individually connected to the pressure chambers 50 due to pressure fluctuations in the pressure chambers 50. The head chip 32 has a chip module 37 and a nozzle plate 39.

[0031] As shown in FIG. 3, the chip module 37 is formed in a block shape with the thickness direction being the Z direction and the longitudinal direction being the X direction. The chip module 37 is fitted into the chip accommodating section 31a. Specifically, the chip module 37 is formed so that the thickness in the Z direction is equal to that of the flow path frame member 31 and the planar shape is equal to that of the chip accommodating section 31a. In this case, the +X side end face of the chip module 37 is fixed by adhesion or the like to the surface facing the -X side of the inner surface of the chip accommodating section 31a, and the -X side end face is fixed by adhesion or the like to the surface facing the +X side of the inner surface of the chip accommodating section 31a. Therefore, in 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] Fig. 5 is a plan view of actuator plate 41. Fig. 6 is a cross-sectional view of head chip 32 corresponding to line VI-VI in Fig. 4. Fig. 7 is a cross-sectional view of discharge unit 30 corresponding to line VII-VII in Fig. 6. Fig. 8 is a cross-sectional view of discharge unit 30 corresponding to line VIII-VIII in Fig. 6. As shown in FIGS. 4 to 8, the chip module 37 includes an actuator plate 41, a support plate 42, and an intermediate plate 43. The chip module 37 is configured by stacking the intermediate plate 43, the actuator plate 41, and the support plate 42 in this order. In the following description, the Z direction may be described as the upper side from the intermediate plate 43 toward the support plate 42 (+Z side), and the Z direction may be described as the lower side from the support plate 42 toward the intermediate plate 43 (-Z side). In the first embodiment, the lower surface of the head chip 32 is disposed flush with the lower surface of the flow path frame member 31. On the other hand, the upper surface of the head chip 32 is disposed 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 a pressure fluctuation in the pressure chamber 50 when ink is ejected. The actuator plate 41 is formed of a piezoelectric material such as PZT (lead zirconate titanate). For example, a so-called monopole substrate in which the polarization direction is one direction over the entire area in the Z direction is used for the actuator plate 41. In other words, the actuator plate 41 is formed integrally without a bonding interface. Note that a so-called chevron substrate formed by stacking two piezoelectric plates in which the polarization directions are different in the Z direction may also be used for the actuator plate 41.

[0034] The actuator plate 41 includes a facing portion 55 and a partition portion 56 . The facing portion 55 is formed in a plate shape with its thickness direction in the Z direction. The facing portion 55 constitutes the top wall of each pressure chamber 50. That is, the facing portion 55 is located above all of the pressure chambers 50 so as to straddle each of the pressure chambers 50. The partitions 56 protrude downward from the opposing portions 55 and extend parallel to each other over the entire length of the opposing portions 55 in the Y direction. The partitions 56 separate adjacent pressure chambers 50 in the X direction. In other words, the partitions 56 form side walls of the pressure chambers 50.

[0035] A recess 57 is formed in each of the opposing portions 55 at portions located between the partition portions 56 adjacent to each other in the X direction. The recess 57 opens at the lower surface of the opposing portion 55 and extends linearly over the entire length of the opposing portion 55 in the Y direction. The recess 57 also functions as a part of the pressure chamber 50.

[0036] 6, the width of the recess 57 in the X direction is narrower than the distance between adjacent partitions 56. The recess 57 is provided at a position that includes the center of the pressure chamber 50 in the X direction and does not contact the partitions 56. Therefore, the pressure chamber 50 is formed in a stepped shape in which the width in the X direction at an upper portion is narrower than the width in the X direction at a lower portion in the cross-sectional view shown in FIG. 6. In the first embodiment, the center of the recess 57 in the X direction coincides with the center of the pressure chamber 50 in the X direction. Further, the depth in the Z direction of the recess 57 is set to be equal to or greater than half the thickness in the Z direction of the opposing portion 55 and equal to or greater than 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 a portion located between adjacent recesses 57 in the X direction. The dividing groove 58 opens at 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 positions offset from each other when viewed from the Z direction) and extends parallel to the recesses 57 in a plan view. Both ends of the dividing groove 58 in the Y direction are not opened at both end surfaces of the opposing portion 55 in the Y direction.

[0038] As shown in FIG. 6, the width of the dividing groove 58 in the X direction is less than the distance between the adjacent recesses 57. The dividing groove 58 is provided at a position including the center of the partition portion 56 in the X direction and not in contact with the recesses 57. In the first embodiment, the dividing groove 58 is formed so that the center in the X direction coincides with the center in the X direction of the partition portion 56 and the width in the X direction is narrower than the width in the X direction of the partition portion 56. Therefore, the entirety of the dividing groove 58 overlaps with the entirety of the partition portion 56 in a plan view. The width of the dividing groove 58 may be equal to or greater than the width of the partition portion 56. It is sufficient that the partition portion 56 and the dividing groove 58 at least partially overlap with each other in a plan view.

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

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

[0041] A portion of the facing portion 55 located between the recesses 57 and the dividing grooves 58 adjacent to each other in the X direction constitutes a driving portion 59. In a cross-sectional view perpendicular to the Y direction, the driving portion 59 has a thickness equivalent to that of the facing portion 55. The width of the facing portion 55 in the X direction is narrower than the recesses 57, the dividing grooves 58, and the partition portion 56. In the illustrated example, the driving portion 59 is provided at a position that does not overlap the entire partition portion 56 in a plan view. However, a portion of the driving portion 59 may overlap 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 with respect to one pressure chamber 50. In the following description, the drive unit 59 located at the +X side end of the pressure chamber 50 may be referred to as the +X side drive unit 59a, and the drive unit 59 located at the -X side 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 one pressure chamber 50 on the +X side. 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 one pressure chamber 50 on the -X side.

[0043] <Support plate 42> As shown in FIGS. 4 and 6, the support plate 42 ensures the rigidity of the chip module 37, and is stacked on the actuator plate 41 to support the support plate 42 from above. The support plate 42 is in the form of a plate formed to have the same outer shape as the actuator plate 41 in a plan view. The support plate 42 is fixed to the upper surface of the actuator plate 41 (facing portion 55) by adhesion or the like. In the illustrated example, the support plate 42 is thicker than the actuator plate 41. However, the support plate 42 may be thinner than the actuator plate 41. The support plate 42 can be formed of, for example, a metal, a metal oxide, glass, a resin, ceramics, or the like.

[0044] FIG. 9 is a bottom view of the support plate 42. 6 to 9, the support plate 42 has a deformable portion 60 formed at a position overlapping at least a part of the drive portion 59 in a plan view. The deformable portion 60 is a groove that opens on the lower surface of the support plate 42. In a plan view, the deformable portion 60 extends linearly in the Y direction along the pressure chamber 50 at portions located at both ends (outer peripheries) in the X direction of the pressure chamber 50. Specifically, of the deformable portions 60, the deformable portion 60 located on the +X side is formed so as to straddle (so as to overlap in a plan view) the entire +X side drive portion 59a corresponding to one pressure chamber 50, the separating groove 58, and the -X side drive portion 59b corresponding to another pressure chamber 50 adjacent to the one pressure chamber 50 in the X direction. Of the deformable portions 60, the deformable portion 60 located on the -X side is formed in the X direction so as to span (so as to overlap in a plan view) the entire -X side drive portion 59b corresponding to one pressure chamber 50, the separating groove 58, and the +X side drive portion 59a corresponding to another pressure chamber 50 adjacent to the one pressure chamber 50. Therefore, in the cross-sectional view shown in FIG. 6, the drive portion 59 and the separating groove 58 are not in contact with the support plate 42.

[0045] As shown in Figures 7 and 8, the length of the deformation allowing 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 allowing 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 allowing portion 60 is formed to have the same length as the dividing groove 58. In a plan view, the deformation allowing portion 60 overlaps with the entirety of the dividing groove 58 in the Y direction. Therefore, in the cross-sectional views shown in Figures 7 and 8, the drive portion 59 and the dividing groove 58 are not in contact with the support plate 42. However, the dimensions of the deformation allowing portion 60 can be changed as appropriate.

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

[0047] The common conductive 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 conductive portion 61 includes a common recess 65 and a common wiring groove 66. The common recess 65 is open on the upper surface of the support plate 42. The common recess 65 constitutes an upper end opening of the common conductive 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 conductive portion 61. The common wiring groove 66 is provided so as to cross between the multiple common recesses 65 in the X direction. The common wiring groove 66 communicates with each common recess 65 through a portion overlapping with the common recess 65 in a plan view. A portion of the common conductive portion 61 where the common recess 65 and the common wiring groove 66 communicate with each other constitutes a common through portion 67 that penetrates the support plate 42 in the Z direction. The common wiring groove 66 does not necessarily have to span all the common recesses 65, but may at least span between adjacent common recesses 65.

[0049] The individual conductive portion 62 is formed in a position of the support plate 42 that overlaps, for example, the -Y side end portion of the deformation allowance portion 60 in a plan view. The individual conductive portion 62 includes an individual recess 70 and an individual wiring groove 71. The individual recesses 70 open on the upper surface of the support plate 42. The individual recesses 70 form the upper end openings of the individual conductive portions 62. A plurality of individual recesses 70 are provided at intervals in the X direction. In the first embodiment, the common recesses 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 cross between the multiple individual recesses 70 in the X direction. 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. A portion of the individual conductive portion 62 where the individual recess 70 and the individual wiring groove 71 communicate with each other constitutes an individual through portion 73 that penetrates the support plate 42 in the Z direction. Note that the individual wiring groove 71 does not necessarily have to span all the individual recesses 70, but may at least span between adjacent individual recesses 70.

[0051] As shown in FIG. 4 and FIG. 6, the intermediate plate 43 is overlapped with 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 bonded to the lower surface of the actuator plate 41 via an adhesive or the like. As a result, the intermediate plate 43 covers the lower end openings of the pressure chambers 50 collectively. The intermediate plate 43 is preferably formed of a material having a higher rigidity than the nozzle plate 39. However, the intermediate plate 43 may be formed of a material having a lower 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 formed of a single layer structure or a laminated structure of a resin material, a metal material, glass, silicon, or the like.

[0052] The intermediate plate 43 is formed with a plurality of communication holes 43a penetrating the intermediate plate 43 in the Z direction. In a plan view, each communication hole 43a overlaps with each pressure chamber 50. In the first embodiment, each communication hole 43a opens to each pressure chamber 50 at the center in the Y direction and the X direction.

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

[0054] <Nozzle plate 39> The nozzle plate 39 collectively covers the lower surface of the chip module 37 and the flow path frame member 31. The nozzle plate 39 is bonded to the lower surface of the intermediate plate 43 and the flow path frame member 31 via an adhesive or the like. As a result, the nozzle plate 39 collectively covers the lower end openings of the inlet common flow path 31b and the outlet common flow path 31c and the lower end openings of the communication hole 43a, and 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., other than the resin material.

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

[0056] In the first embodiment, the communication hole 43a is only required 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 in the illustrated example, or may be the same shape as the pressure chamber 50.

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

[0058] The common electrode 81a is formed on at least the inner surface of each recess 57 of the lower surface of the facing portion 55. In the example shown in the figure, the common electrode 81a is formed over the entire inner surface of the recess 57. That is, the entire common electrode 81a faces the inside of 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 across 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. 4 and 5, the top surface wiring 81c is formed at the +Y side end of the top surface of the facing portion 55. The top surface wiring 81c is formed in a band shape extending in the X direction on the top surface of the facing portion 55. The top surface wiring 81c is connected to the end surface wiring 81b at the boundary between the top surface of the facing portion 55 and the +Y side end surface. The top surface wiring 81c is separated from the dividing groove 58 in the Y direction.

[0060] 8, the through wiring 81d is for connecting between the upper surface routed wiring 81c and the common pad 81e, and is provided to penetrate the support plate 42. The through wiring 81d is formed on the inner surface of the common through portion 67. The through wiring 81d is connected to the upper surface routed wiring 81c at the lower end edge of the common through portion 67. It is sufficient that the through wiring 81d is ensured to be conductive over the entire length in the Z direction of the inner surface of the common through portion 67. In other words, the through wiring 81d may be formed, for example, over the entire circumferential direction of the inner surface of the common through portion 67, or may be formed only in a part of the circumferential direction.

[0061] FIG. 10 is a plan view of the support plate 42. As shown in FIG. 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 edge of the upper opening of the common through portion 67.

[0062] As shown in FIGS. 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 lead-out 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 facing 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 facing portion 55 in a portion that overlaps with the recessed portion 57 in a plan view. Therefore, the first individual electrodes 82a face the common electrode 81a in the Z direction with the facing portion 55 sandwiched therebetween. On the upper surface of the facing portion 55, the +Y side end of the first individual electrode 82a is separated from the upper surface lead-out wiring 81c.

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

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

[0066] The through wiring 82e is for connecting between the upper surface routed wiring 82d and the individual pads 82f, and is provided to penetrate the support plate 42. The through wiring 82e is formed on the inner surface of the individual through portion 73. The through wiring 82e is connected to the upper surface routed wiring 82d at the lower end edge of the individual through portion 73. It is sufficient that the through wiring 82e ensures electrical continuity over the entire length in the Z direction of the inner surface of the individual through portion 73. In other words, the through wiring 82e may be formed, for example, over the entire circumferential direction of the inner surface of the individual through portion 73, or may be formed only in a part of the circumferential direction.

[0067] 4 and 10, the individual pad 82f is formed on the upper surface of the support plate 42. The individual pad 82f is connected to the through wiring 82e at the upper opening edge of the individual through portion 73.

[0068] As shown in FIG. 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 portion 56. As a result, the protective film 88 protects the common electrode 81a. The protective film 88 contains an organic insulating material such as a paraxylylene-based resin material (e.g., Parylene (registered trademark)) as a material having insulating properties. The protective film 88 is made of tantalum oxide (Ta 2 O 5 ), silicon nitride (SiN), silicon carbide (SiC), silicon oxide (SiO 2 ), diamond-like carbon, or the like, or may contain at least one of these.

[0069] <Flow passage cover 34> 3 and 7, the flow path cover 34 sandwiches the flow path frame member 31 and the chip module 37 between itself and a reinforcing plate 38. The flow path cover 34 includes a cover base 90, an inlet port 91, and an outlet port 92. The cover base 90 is a rectangular plate whose planar outer shape is formed to be the same as that of the flow path frame member 31. The cover base 90 is overlaid on the upper surfaces of the flow path frame member 31 and the chip module 37. The cover base 90 is bonded to the upper surfaces of the flow path frame member 31 and the chip module 37 via an adhesive or the like, and is fastened to the flow path frame member 31 with screws or the like. As a result, the cover base 90 closes the upper end openings of the inlet common flow path 31b and the outlet common flow path 31c.

[0070] A slit 90a is formed in the center 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 at a position overlapping the center of the chip module 37 (excluding the outer periphery) in a plan view. That is, the dimension of the slit 90a in the Y direction is smaller than the dimension of the chip module 37 in the Y direction. The dimension of the slit 90a in the X direction is smaller than the dimension of the chip module 37 in the X direction. 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 end of the cover base 90 on the +Y side and the +X side. The inlet port 91 protrudes upward from the cover base 90. The inlet port 91 communicates with the inlet common flow channel 31b through the +X side end of the inlet common flow channel 31b (the portion protruding toward the chip accommodation section 31a). That is, the ink flowing through the ink supply tube 21 is supplied to the inlet common flow channel 31b through the inlet port 91. The outlet port 92 is located at the end of the cover base 90 on the -Y side and the -X side. The outlet port 92 protrudes upward from the cover base 90. The outlet port 92 communicates with the outlet common flow path 31c through the -X side end of the outlet common flow path 31c (the portion protruding toward the chip housing portion 31a). That is, the ink flowing through the outlet common flow path 31c is discharged to the ink discharge tube 22 through the outlet port 92.

[0072] The flexible printed circuit board 35 is pressure-bonded to the upper surface of the support plate 42 through the slit 90a. The flexible printed circuit board 35 is connected to the common pad 81e and the individual pads 82f on the upper surface of the support plate 42. The flexible printed circuit board 35 is pulled out upward and then connected to a control unit.

[0073] [Printer 1 operation method] Next, a case where characters, figures, etc. are recorded on a recording medium P using the printer 1 configured as described above will be described below. 1 are each fully filled with ink of a different color. Also, the ink in the ink tanks 4 is filled in the inkjet head 5 via the ink circulation mechanism 6.

[0074] When the printer 1 is operated in this initial state, the recording medium P is conveyed to the +X side while being sandwiched between the rollers 11 and 12 of the conveying mechanisms 2 and 3. At the same time, the carriage 29 moves in the Y direction, causing the inkjet head 5 mounted on the carriage 29 to move back and forth in the Y direction. While the inkjet heads 5 are moving back and forth, ink is appropriately ejected from each inkjet head 5 onto the recording medium P. In this way, characters, images, etc. can be recorded on the recording medium P.

[0075] The movement of each ink-jet head 5 will now be described in detail. In the inkjet head 5 of the circulation type side chute type as in the first embodiment, first, the pressurizing pump 24 and the suction pump 25 shown in FIG. 2 are operated to circulate ink in the circulation flow path 23. In this case, the ink flowing in the ink supply pipe 21 is supplied into the inlet common flow path 31b through the inlet port 91. The ink supplied to the inlet common flow path 31b is distributed to each pressure chamber 50 through the +Y side opening of each pressure chamber 50, and then flows through each pressure chamber 50 to the -Y side. After that, the ink is discharged to the outlet common flow path 31c through the -Y side opening of each pressure chamber 50. The ink discharged to the outlet common flow path 31c flows into the ink discharge pipe 22 through the outlet port 92, and is returned to the ink tank 4. In this way, the ink can be circulated between the inkjet head 5 and the ink tank 4.

[0076] Then, when the inkjet head 5 starts to move back and forth due to the movement of the carriage 29 (see FIG. 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 drive voltage is applied with the common electrode 81a at a reference potential GND and the individual electrodes 82a to 82c at a drive potential Vdd. Then, a potential difference occurs between the common electrode 81a and the individual electrodes 82a to 82c that face each other across the facing portion 55, generating an electric field in the facing portion 55.

[0077] Specifically, a potential difference occurs between the common electrode 81a and the first individual electrode 82a in the Z direction. Due to the potential difference occurring in the Z direction, an electric field is generated in the facing 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. In addition, a potential difference occurs 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 occurring in the X direction, an electric field is generated in the driving portion 59, and the driving portion 59 undergoes thickness slip deformation in the Z direction due to the shear mode. As a result, the portions of the facing portion 55 corresponding to each pressure chamber 50 shear deform upward from both ends toward the center in the X direction. That is, in the head chip 32 of the first embodiment, the deformations caused by the shear mode and the bend mode of the actuator plate 41 both extend in the Z direction. Specifically, due to the application of a drive voltage, the actuator plate 41 (facing portion 55) deforms in a direction away from the pressure chamber 50. As a result, the volume inside the pressure chamber 50 increases.

[0078] Thereafter, when the driving voltage is set to zero, the opposing portion 55 returns to its original state, and the volume inside the pressure chamber 50 tries to return to its original state. In 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 print information is recorded on the recording medium P.

[0079] <Method of Manufacturing Discharge Unit 30> Next, a description will be given of a method for manufacturing the above-mentioned discharge unit 30. Fig. 11 is a flow chart for explaining a method for manufacturing the discharge unit 30. 11, the manufacturing method of the discharge unit 30 includes a first actuator processing step S11, a first support plate processing step S12, a first bonding step S13, a second actuator processing step S14, a second support plate processing step S15, a protective film forming step S16, a second bonding step S17, an assembly step S18, and a third bonding step S19. For convenience, the following description will be given taking as an example a case where the chip module 37 is manufactured at the chip level.

[0080] 12 and 13 are process drawings for explaining the actuator first processing step S11, and are cross-sectional views corresponding to FIG. 12, in the actuator first processing step S11, dividing grooves 58 are formed in the actuator plate 41 (dividing groove forming step). Specifically, the dividing grooves 58 are formed by performing a dicing process or the like on the upper surface of the actuator plate 41.

[0081] Next, in the first actuator processing step S11, as shown in FIG. 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 lead-out wirings 81c, 82d, etc.) is formed (first wiring formation step). In the first wiring formation step, first, a mask pattern having openings in areas where the drive wiring is to be formed is formed on the upper surface of the actuator plate 41. Next, an electrode material is formed on the actuator plate 41 by, for example, oblique deposition. The electrode material is formed on the actuator plate 41 through the openings of the mask pattern. As a result, the drive wiring is formed on the upper surface of the actuator plate 41 and on the inner surface of the dividing groove 58. Thereafter, the bottom surface of the dividing groove 58 is irradiated with laser light to separate the second individual electrode 82b corresponding to one pressure chamber 50 and the third individual electrode 82c corresponding to another pressure chamber 50 adjacent to the one pressure chamber 50 at the bottom surface of the dividing groove 58.

[0082] 14 to 16 are process drawings for explaining the first support plate processing step S12, and are cross-sectional views corresponding to FIG. As shown in Fig. 14, in the support plate processing step S12, first, conductive parts 61, 62 are formed in the support plate 42. Specifically, a common recess 65 and an individual recess 70 are formed in the upper surface of the support plate 42 by sandblasting or the like. Then, as shown in Fig. 15, a common wiring groove 66 and an individual wiring groove 71 are formed in the lower surface of the support plate 42 by dicing or the like. At this time, the common wiring groove 66 and the individual wiring groove 71 are formed so that the common wiring groove 66 and the common recess 65 communicate with each other and the individual wiring grooves 71 and the individual recesses 70 communicate with each other. As a result, the conductive parts 61, 62 are formed.

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

[0084] FIG. 17 is a process diagram for explaining the first bonding step S13, and is a cross-sectional view corresponding to FIG. 17, in the first bonding process S13, the support plate 42 is attached to the upper surface of the actuator plate 41 with an adhesive or the like. In the first bonding process S13, excess adhesive is washed away when the actuator plate 41 and the support plate 42 are pressed together, and is contained in the common wiring groove 66, the individual wiring groove 71, and the deformation allowance portion 60.

[0085] FIG. 18 is a process diagram for explaining the actuator second processing step S14, and is a cross-sectional view corresponding to FIG. 18, in the second actuator processing step S14, a groove having a width corresponding to the recess 57 is formed in the lower surface of the actuator plate 41 by dicing or the like. Then, of the drive wiring, a portion located on the lower surface or +Y side end surface of the actuator plate 41 (common electrode 81a, end surface lead-out wiring 81b, etc.) is formed (second wiring formation step). After that, for example, by performing dicing or the like on the lower surface of the actuator plate 41, a portion of the pressure chamber 50 corresponding to between adjacent partition portions 56 is formed.

[0086] In the second actuator processing step S14, grinding or the like is appropriately performed to smooth the lower surface of the actuator plate 41. At this time, since the support plate 42 is laminated 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, the through wirings 81d, 82e and the pads 81e, 82f of the drive wirings are formed on the support plate 42 (third wiring forming step). Specifically, a mask pattern having openings for the formation regions of the through wirings 81d, 82e and the pads 81e, 82f is formed on the upper surface of the support plate 42. Next, an electrode material is formed on the support plate 42 by, for example, oblique deposition from the Y direction. The electrode material is formed on the support plate 42 through the openings of the mask pattern. As a result, the through wirings 81d, 82e and the pads 81e, 82f are formed.

[0088] FIG. 19 is a process diagram for explaining the protective film forming step S16, and is a cross-sectional view corresponding to FIG. In the protective film forming step S16, a protective film 88 is formed on the lower surface of the actuator plate 41 as shown in FIG.

[0089] In the second bonding step S17, the intermediate plate 43 is attached to the lower surface of the actuator plate 41 with an adhesive or the like. Through the above steps, the chip module 37 is completed.

[0090] Thereafter, in an assembly process S18, the chip module 37 is assembled to the flow path frame member 31. Specifically, the chip module 37 is fitted into the chip accommodation 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] Next, in a third bonding process S19, a nozzle plate 39 is attached so as to cover the lower surface of the flow path frame member 31 and the lower surface of the chip module 37. Thereafter, a flow path cover 34 is attached to the upper surface of the flow path frame member 31. Through the above steps, the discharge unit 30 is completed.

[0092] As described above, the head chip 32 of the first embodiment includes an actuator plate 41 having an opposing portion 55 with a recess (recess) 57 formed on its lower surface (first surface) and a dividing groove (recess) 58 formed on its upper surface (second surface), a common electrode 81a provided on the lower surface of the opposing portion 55 and functioning as a reference potential GND, and individual electrodes 82a to 82c provided on the upper surface of the opposing portion 55, which is a surface other than the lower surface of the opposing portion 55. Of the common electrode 81a and the individual electrodes 82a to 82c, the common electrode 81a is formed on at least the inner surface of the recess 57. The individual electrodes 82b, 82c are formed on at least the inner surfaces of the dividing groove 58. According to this configuration, since the recesses 57 and the dividing grooves 58 are formed in the actuator plate 41, it is easy to ensure the rigidity of the actuator plate 41 as a whole. Therefore, it is possible to improve manufacturing efficiency and yield. Furthermore, in the first embodiment, since the drive electrodes are also formed in the recesses 57 and the dividing grooves 58, it is possible to ensure the surface area of ​​the drive electrodes (common electrode 81a and individual electrodes 82b, 82c) and it is easy to ensure the opposing area of ​​the common electrode 81a and the individual electrodes 82b, 82c. Therefore, it is possible to improve the pressure generated in the pressure chamber 50 when ink is ejected. In particular, in the first embodiment, since the individual electrodes 82a to 82c are formed on the upper surface of the facing portion 55, only the common electrode 81a is formed on the lower surface of the facing portion 55. Therefore, short-circuiting between the common electrode 81a and the individual electrodes 82b and 82c via the ink can be suppressed compared to a configuration in which the common electrode 81a and the individual electrodes 82b and 82c are provided on the lower surface of the facing portion 55. This makes it possible to provide a head chip 32 that is excellent in durability and reliability.

[0093] In the head chip 32 of the first embodiment, the actuator plate 41 is set with the polarization direction being the Z direction (thickness direction), a recess (first recess) 57 formed on the lower surface of the opposing portion 55 is positioned in a portion facing the pressure chamber 50 when viewed from the Z direction, and a separating groove (second recess) 58 formed on the upper surface of the opposing portion 55 is positioned in a position offset from the recess 57 when viewed from the Z direction. According to this configuration, an electric field is generated in the driving portion 59 of the actuator plate 41 due to a potential difference generated between the common electrode 81a formed in the recess 57 and the individual electrodes 82b, 82c formed in the dividing groove 58. This causes the driving portion 59 to deform in the Z direction of the actuator plate 41 due to a so-called shear mode. As a result, the amount of deformation of the actuator plate 41 is ensured, and it is easy to ensure the pressure generated in the pressure chamber 50.

[0094] In head chip 32 of the first embodiment, first individual electrode 82a is formed on the upper surface of facing portion 55 in a portion other than separating groove 58. According to this configuration, by generating a potential difference between the first individual electrode 82a and the common electrode 81a, an electric field can be generated in the Z direction of the actuator plate 41. This allows the actuator plate 41 to deform in the Z direction in a bend mode (bimorph type). This allows the generated pressure to be further improved.

[0095] In the head chip 32 of the first embodiment, the actuator plate 41 is integrally formed with the Z direction as the polarization direction. According to this configuration, by using a so-called monopole type actuator plate 41 in which the polarization direction is set in one direction, unlike when an actuator plate is configured by stacking a plurality of piezoelectric materials with different polarization directions, there is no joint surface between the piezoelectric materials. Therefore, it is possible to prevent ink from bridging between the common electrode 81a and the individual electrodes 82a to 82c through the joint interface in the actuator plate 41. As a result, the possibility of a short circuit can be reduced.

[0096] In head chip 32 of the first embodiment, actuator plate 41 is provided on the lower surface of facing portion 55 with protective film 88 that covers common electrode 81a. According to this configuration, by covering the common electrode 81a with the protective film 88, it is possible to suppress contact between the common electrode 81a and ink, and to improve the durability of the common electrode 81a.

[0097] The head chip 32 of the first embodiment includes a nozzle plate (injection hole plate) 39 that is provided facing the actuator plate 41 in the Z direction and has a plurality of injection holes 39a that are respectively connected to the plurality of pressure chambers 50 and penetrate the head chip 32 in the Z direction. The actuator plate 41 includes a facing portion 55 that is provided apart from the nozzle plate 39 in the Z direction, and a partition portion 56 that is formed integrally with the facing portion 55 and separates the adjacent pressure chambers 50. The facing portion 55, located between the adjacent recesses 57 and separating grooves 58, includes a driving portion 59 in which an electric field is generated by a common electrode 81a and individual electrodes 82b, 82c, and at least a part of the partition portion 56 is provided at a position that does not overlap with the driving portion 59 when viewed from the Z direction. According to this configuration, an electric field is generated in the driving section 59 due to a potential difference generated between the common electrode 81a formed in the recess 57 and the individual electrodes 82b, 82c formed in the dividing groove 58. This causes the driving section 59 to deform in the Z direction in a so-called shear mode, thereby enabling ink to be ejected through the nozzle hole 39a. In particular, in the first embodiment, at least a part of the partition portion 56 is provided at a position that does not overlap with the driving portion 59 when viewed from the Z direction, and therefore a gap is generated in the Z direction between the nozzle plate 39 and the driving portion 59. This makes it possible to reduce the inhibition of the deformation of the driving portion 59 by the nozzle plate 39, the intermediate plate 43, etc. when ejecting ink. As a result, it is easy to ensure the amount of deformation of the actuator plate 41 and the pressure generated in the pressure chamber 50. Moreover, in the first embodiment, the partition portion 56 also serves as at least a part of the partition portion 56 that separates the adjacent pressure chambers 50. This makes it possible to improve the positional accuracy between the drive portion 59 and the partition portion 56 in the X direction (arrangement direction of the pressure chambers 50) compared to a configuration in which the entire partition portion 56 is formed of a separate member from the actuator plate 41.

[0098] Since the inkjet head 5 and printer 1 of the first embodiment include the head chip 32 described above, it is possible to provide an inkjet head 5 and printer 1 with excellent reliability.

[0099] Second embodiment 20 is a cross-sectional view of a head chip 32 according to the second embodiment. The second embodiment differs from the first embodiment in that an actuator plate 41 does not include a partition portion 56. In the head chip 32 shown in FIG. 20, a flow path plate 200 is provided between the actuator plate 41 and the nozzle plate 39. The flow path plate 200 is bonded to the lower surface of the actuator plate 41 via an adhesive or the like. A plurality of individual flow paths 201 are formed in the flow path plate 200. Each individual flow path 201 constitutes a pressure chamber 50 together with a corresponding recess 57. The individual flow paths 201 penetrate the flow path plate 200 in the Y direction and the Z direction, and are provided at intervals in the X direction. Note that, in the flow path plate 200, a portion located between adjacent pressure chambers 50 functions as a partition portion 202 that separates the adjacent pressure chambers 50.

[0100] 20, the individual flow paths 201 are formed in a stepped shape such that the width in the X direction at an upper portion is wider than the width in the X direction at a lower portion. The lower end opening of each individual flow path 201 communicates with the corresponding nozzle hole 39a. The width in the X direction of the individual flow paths 201 may be uniform over the entire Z direction.

[0101] According to this configuration, the partitions 202 of the pressure chambers 50 are formed by the flow path plate 200 separate from the actuator plate 41, so that the actuator plate 41 can be made thin. This makes it easier to ensure the amount of deformation of the actuator plate 41 caused by the electric field generated in the actuator plate 41.

[0102] Third embodiment FIG. 21 is a cross-sectional view of a head chip 32 according to the third embodiment. 21, common electrode 81a is formed over the entire lower surface of facing portion 55, including the inner surface of recess 57. That is, common electrode 81a is formed for all pressure chambers 50 collectively.

[0103] According to this configuration, since patterning of the common electrode 81a is not required on the lower surface of the actuator plate 41, it is possible to improve manufacturing efficiency and reduce costs. Note that, in the third embodiment, a configuration in which the common electrode 81a is continuously formed for all the pressure chambers 50 has been described, but this is not limiting. Of all the pressure chambers 50, the common electrodes 81a may be formed collectively for any two or more of the pressure chambers 50.

[0104] In addition, in each of the above-described embodiments, the support plate 42 is formed with the deformable portion 60, but the present invention is not limited to this configuration. As in the third embodiment, the deformable portion 60 is not an essential component.

[0105] (Fourth embodiment) 22 is a cross-sectional view of head chip 32 according to the fourth embodiment. The fourth embodiment differs from the above-described embodiments in that dividing groove 58 is not formed and common electrodes 81j, 81k are also formed on the upper surface of actuator plate 41. In the head chip 32 shown in FIG. 22, a second common electrode 81j and a third common electrode 81k are formed on the upper surface of the actuator plate 41. As shown in FIG.

[0106] The second common electrode 81j is a portion of the upper surface of the actuator plate 41 that is located on the +X side with respect to the first individual electrode 82a, and is formed at a position that overlaps with the +X side end of the pressure chamber 50 in a plan view. The third common electrode 81k is a portion of the upper surface of the actuator plate 41 that is located on the -X side with respect to the first individual electrode 82a, and is formed at a position that overlaps with the -X side end of the pressure chamber 50 in a plan view.

[0107] According to this configuration, a potential difference occurs in the X direction between the first individual electrode 82a and the second common electrode 81j, and between the first individual electrode 82a and the third common electrode 81k. The potential difference occurring in the X direction generates an electric field in a direction perpendicular to the polarization direction (Z direction) in the actuator plate 41. As a result, the actuator plate 41 undergoes thickness slip deformation in the Z direction due to shear mode. In addition, in the third embodiment, since the dividing groove 58 is not provided, it is possible to suppress the occurrence of chipping of the actuator plate 41 and improve handling. As a result, it is possible to improve manufacturing efficiency and yield.

[0108] Fifth embodiment FIG. 23 is a cross-sectional view of a head chip 32 according to the fifth embodiment. 23, individual wirings 82 may not have first individual electrodes 82a. That is, head chip 32 of the fifth embodiment includes, as individual wirings 82, second individual electrodes 82b and third individual wirings 82c.

[0109] According to this configuration, since the first individual electrodes 82a are not provided on the upper surface of the actuator plate 41, the layout of the drive wiring can be facilitated.

[0110] Sixth embodiment 24 is a cross-sectional view of head chip 32 according to the eighth embodiment. The sixth embodiment differs from the above-described embodiments in that a so-called edge shoot type head chip 32 is used. The head chip 300 shown in FIG. 24 includes an actuator plate 301 , a cover plate 302 , a support plate 303 , and a nozzle plate 304 .

[0111] As in the first embodiment described above, the actuator plate 301 has a plurality of pressure chambers 50 formed side by side in the X direction. In this embodiment, the pressure chambers 50 have their -Z side ends open on the lower surface of the actuator plate 301 and their +Z side ends closed.

[0112] The cover plate 302 is stacked on the +Y side with respect to the actuator plate 301. 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, for example, by a length spanning the multiple pressure chambers 50, and is open on the surface of the cover plate 302 facing the +Y side. Slits 302b are formed in the cover plate 302 at positions overlapping with the pressure chambers 50 when viewed from the Y direction. The slits 302b connect the common ink chamber 302a and each pressure chamber 50 individually.

[0113] The support plate 303 is stacked on the -Y side with respect to the actuator plate 301. In the support plate 303, a deformation allowable portion 303a is formed on the surface facing the +Y side, similarly to the first embodiment.

[0114] The nozzle plate 304 collectively covers the lower surfaces of the actuator plate 301, the cover plate 302, and the support plate 303. In the nozzle plate 304, nozzle holes 304a are formed in portions that overlap the pressure chambers 50 in a plan view.

[0115] According to this configuration, the ink in the common ink chamber 302a flows through the slit 302b into the pressure chamber 50. The ink in the pressure chamber 50 is ejected to the outside through the nozzle hole 304a due to pressure fluctuations in the pressure chamber 50 caused by application of a drive voltage.

[0116] (Other variations) The technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure. For example, in the above embodiment, the inkjet printer 1 has been described as an example of a liquid jet recording apparatus, but the liquid jet recording apparatus is not limited to a printer. For example, the liquid jet recording apparatus may be a fax machine, an on-demand printer, or the like. In the above-described embodiment, a configuration in which the inkjet head moves relative to the recording medium during printing (so-called shuttle machine) has been described as an example, but the present disclosure is not limited to this configuration. The configuration according to the present disclosure may be adopted in a configuration in which the recording medium moves relative to the inkjet head while the inkjet head is fixed (so-called fixed head machine). In the above embodiment, the recording medium P is paper, but this is not limited to the above configuration. The recording medium P is not limited to paper, and may be a metal material, a resin material, or a food product. In the above-described embodiment, the liquid ejection head is mounted on the liquid ejection recording device, but the present invention is not limited to this configuration. In other words, the liquid ejected from the liquid ejection head is not limited to the liquid that is to be landed on the recording medium, and may be, for example, a medicinal liquid to be mixed in a medicine, a food additive such as a seasoning or a fragrance to be added to food, or an aromatic to be sprayed into the air.

[0117] In the above embodiment, the configuration has been described in which the Z direction coincides with the direction of gravity, but the present invention is not limited to this configuration, and the Z direction may be aligned with the horizontal direction. In the above-described embodiment, a configuration in which the dividing groove 58 and the recess 57 are formed in the actuator plate 41 has been described, but the present invention is not limited to this configuration. At least one of the first recess and the second recess may be formed in the actuator plate 41. Furthermore, the first recess and the second recess may be formed in positions that overlap each other in a plan view. In each of the above-described embodiments, a configuration has been described in which the pressure chamber 50 is formed as a groove that linearly penetrates the chip module 37 in the Y direction, but the configuration is not limited to this. The pressure chamber 50 can be appropriately modified, for example, to a circular shape in a plan view. For example, even when the pressure chamber 50 is formed in a circular shape, it is preferable that the deformation allowance portion extends along the outer periphery of the pressure chamber 50 in a plan view.

[0118] In the above embodiment, the actuator plate 41 is deformed in both the bend mode and the shear mode, but the present invention is not limited to this configuration. The actuator plate 41 may be deformed in at least one of the bend mode and the shear mode. In the above embodiment, the adjacent pressure chambers 50 are separated only by either the partition portion 56 of the actuator plate 41 or the partition portion 202 of the flow path plate 200, but the present invention is not limited to this configuration. The adjacent pressure chambers 50 may be separated by both the partition portion 56 of the actuator plate 41 and the partition portion 202 of the flow path plate 200. In the above-described embodiment, the configuration in which the individual electrodes are formed only on the upper surface of the actuator plate 41 (opposing portion 55) has been described, but the present invention is not limited to this configuration. As long as the individual electrodes are formed on at least the upper surface of the actuator plate 41, they may be formed separately on a surface other than the lower surface.

[0119] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0120] 1: Printer (liquid jet recording device) 5: Inkjet head (liquid ejection head) 32: Head chip 39: Nozzle plate (injection hole plate) 39a: Nozzle hole (injection hole) 41: Actuator plate 50: Pressure chamber 55: Opposing part 56: Partition 57: Recess (recess, first recess) 58: Dividing groove (recess, second recess) 58a: +X side dividing groove (recess, second recess) 58b: -X side dividing groove (recess, second recess) 59: Drive unit 59a: +X side drive unit (drive unit) 59b:-X side drive unit (drive unit) 81a: Common electrode 82a: 1st individual electrode (individual electrode) 82b: 2nd individual electrode (individual electrode) 82c: 3rd individual electrode (individual electrode) 88:Protective film 300: Head chip 301: Actuator plate 304: Nozzle plate (injection hole plate)

Claims

1. an actuator plate having a first surface facing a plurality of pressure chambers in which liquid is accommodated, and a second surface facing a side opposite to the pressure chambers with respect to the first surface in a thickness direction, a recess being formed in at least one of the first surface and the second surface, and the thickness direction being set as a polarization direction; a common electrode provided on the first surface and functioning as a reference potential; an individual electrode provided on the second surface other than the first surface, the individual electrode generating a potential difference between the individual electrode and the common electrode to generate an electric field in the actuator plate; one of the common electrode and the individual electrode formed on the one surface is formed on at least an inner surface of the recess, The recesses are formed in each of the first surface and the second surface, Among the recesses, a first recess formed on the first surface is disposed in a portion facing the pressure chamber as viewed in the thickness direction, Among the recesses, a second recess formed on the second surface is disposed at a position shifted from the first recess when viewed in the thickness direction, The individual electrodes are formed on at least the inner surface of the second recess.

2. The head chip according to claim 1 , wherein the individual electrodes are formed on the second surface in a portion other than the second recess.

3. 3. The head chip according to claim 1, wherein the common electrode is formed over the entire first surface.

4. 3. The head chip according to claim 1, wherein the actuator plate is integrally formed with the thickness direction as a polarization direction.

5. 3. The head chip according to claim 1, wherein the actuator plate is provided with a protective film covering the common electrode on the first surface.

6. An actuator plate having a first surface facing a plurality of pressure chambers in which liquid is contained, and a second surface facing the opposite side of the pressure chambers relative to the first surface in a thickness direction, with a recess formed on at least one of the first surface and the second surface; a common electrode provided on the first surface and functioning as a reference potential; an individual electrode provided on the second surface other than the first surface, the individual electrode generating a potential difference between the individual electrode and the common electrode to generate an electric field in the actuator plate; an injection hole plate having a plurality of injection holes penetrating in the thickness direction and respectively communicating with the plurality of pressure chambers, the injection hole plate being provided facing the actuator plate in the thickness direction, one of the common electrode and the individual electrode formed on the one surface is formed on at least an inner surface of the recess, The actuator plate includes: an opposing portion having the first surface and the second surface and spaced apart from the injection hole plate in the thickness direction; a partition portion that is integrally formed with the facing portion, protrudes from the facing portion in the thickness direction, and separates the adjacent pressure chambers, Among the recesses, a first recess formed on the first surface is disposed in a portion facing the pressure chamber as viewed in the thickness direction, Among the recesses, a second recess formed on the second surface is disposed at a position shifted from the first recess when viewed in the thickness direction, The common electrode is formed on an inner surface of the first recess, The individual electrode is formed on an inner surface of the second recess, the facing portion includes a driving portion in which an electric field is generated by the common electrode and the individual electrodes, the driving portion being located between the first recess and the second recess adjacent to each other; At least a part of the partition is provided at a position that does not overlap with the drive section when viewed in the thickness direction.

7. A liquid jet head comprising the head chip according to claim 1 or 2.

8. A liquid jet recording apparatus comprising the liquid jet head according to claim 7.

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