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

Abstract

A head chip (32) comprises: a flow path-defining part that includes a plurality of partitioning parts (46) provided at intervals in an X direction, and that forms, between adjacent partitioning parts from among the plurality of partitioning parts (46), a plurality of individual flow paths (47) through which a liquid can flow in a Y direction; and an actuator part that is stacked, in a Z direction, on the flow path-defining part so as to face the plurality of individual flow paths (47), and that can be deformed so as to enlarge or reduce the interiors of the individual flow paths (47). Defining grooves (49) for communicating the inside and the outside of one individual flow path (47) are formed in portions of partitioning parts (46) in the Y direction. Provided is a nozzle plate which is provided so as to face the flow path-defining part, and in which are formed nozzle holes communicating with positions, in the individual flow paths (47), that are shifted in the Y direction with respect to the defining grooves.

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 to Japanese Patent Application No. 2024-166127 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 actuator plate disposed facing a plurality of pressure chambers and a nozzle plate in which a plurality of nozzle holes communicating with the respective pressure chambers are formed are provided (see, for example, Patent Document 1 below).

[0003] In this type of head chip, to eject ink, a voltage is applied to a drive electrode to generate an electric field in an actuator plate formed of a piezoelectric material. Then, when the actuator plate is deformed, the volume of the pressure chamber expands or contracts. As a result, pressure fluctuations occur in the pressure chamber, and the ink contained in the pressure chamber is ejected through the nozzle holes.

[0004] Japanese Patent No. 7220327 Gazette

[0005] By the way, in the head chip, in the longitudinal direction of the pressure chamber, ink is ejected from the nozzle holes by a combined wave of a pressure wave generated by pressure fluctuations on one side with respect to the nozzle holes and a pressure wave generated by pressure fluctuations on the other side with respect to the nozzle holes. Therefore, the length of the pressure chamber (pump length) is a factor that determines the ejection performance of the head chip. For example, since the responsiveness to the applied waveform (pulse) changes depending on the length of the pressure chamber, it affects the ejection frequency and the like. However, manufacturing a head chip for each required ejection performance (length of the pressure chamber) will lead to a decrease in manufacturing efficiency and an increase in manufacturing cost.

[0006] The present disclosure provides a head chip, a liquid jet head, and a liquid jet recording apparatus that can manufacture a head chip according to required ejection performance simply and at low cost.

[0007] To solve the above problems, the present disclosure adopts the following embodiments: (1) A head tip according to one embodiment of the present disclosure has a plurality of partitions spaced apart in a first direction, and a flow path defining portion that forms a plurality of individual flow paths between adjacent partitions, through which liquid can flow in a second direction intersecting the first direction; and an actuator portion that is superimposed on the flow path defining portion so as to face each of the plurality of individual flow paths in a third direction intersecting the second direction when viewed from the first direction, and is deformable to expand or contract the inside of the individual flow paths, wherein a defined groove is formed in a part of the partition in the second direction that connects the inside of one of the individual flow paths with the outside of one of the individual flow paths, and an injection hole is formed in the individual flow path that communicates with a position shifted in the second direction relative to the defined groove, and an injection hole plate is provided facing the flow path defining portion.

[0008] According to this embodiment, by connecting the inside and outside of individual flow paths with a defined groove, pressure fluctuations generated within the individual flow paths due to deformation of the actuator are released to the outside of the individual flow paths through the defined groove. That is, the portion of the individual flow path located on the injection hole side with respect to the defined groove in the second direction functions as a pressure chamber capable of spraying liquid, while the portion located on the opposite side of the groove in the second direction ceases to function as a pressure chamber. As a result, the length of the pressure chamber (pump length) can be adjusted without changing the dimensions of the flow path defining section and the actuator section in the second direction, and the spray performance of the liquid sprayed through the injection hole can be adjusted. Therefore, it is not necessary to manufacture head tips with dimensions corresponding to the required spray performance. Thus, head tips corresponding to the required spray performance can be manufactured easily and at low cost.

[0009] (2) In the head tip according to the embodiment of (1) above, it is preferable that the defined groove extends linearly in the first direction and connects adjacent individual flow channels. According to this embodiment, by forming the defined groove so as to connect adjacent individual flow channels, the defined groove can be formed collectively on the flow channel defining portion by, for example, dicing. This makes it possible to further improve manufacturing efficiency.

[0010] (3) In the head chip according to the embodiment of (2) above, the actuator portion is provided with a drive electrode that generates an electric field in the actuator portion, and it is preferable that only electrodes of the same polarity are formed on the first surface of the actuator portion that faces the individual flow path in the third direction. According to this embodiment, since only electrodes of the same polarity are formed on the first surface, the increase in the risk of short circuits due to the addition of specified grooves can be suppressed.

[0011] (4) In a head chip according to any embodiment of (3) above, it is preferable that the drive electrode formed on the first surface is a common electrode that is at a reference potential. According to this embodiment, even if common electrodes provided in adjacent individual channels come into contact with each other via liquid, no potential difference is generated between the electrodes, so short circuits of the drive electrodes can be suppressed.

[0012] (5) In a head tip according to any of the embodiments of (2) to (4) above, a common channel is provided on one side in the second direction with respect to the individual channels, extending in the first direction and communicating with the plurality of individual channels, and the specified groove extends in the first direction and communicates with the common channel at one end in the second direction. According to this embodiment, the cross-sectional area of ​​the channel at the connection portion of the individual channel with the common channel can be increased, thereby reducing pressure loss at the connection portion and allowing liquid to flow smoothly between the common channel and the individual channels.

[0013] (6) In a head chip according to any of the embodiments of (2) to (5) above, a common channel is provided on one side in the second direction with respect to the individual channels, extending in the first direction and communicating with the plurality of individual channels, and the specified groove is provided in the partition portion at a position away from the common channel in the second direction. According to this embodiment, the position of the specified groove in the second direction in the partition portion can be easily set freely. This improves the degree of design freedom.

[0014] (7) In a head tip according to any of the embodiments of (2) to (6) above, it is preferable that the specified groove includes a first specified groove provided on the first side in the second direction with respect to the injection hole, and a second specified groove provided on the second side in the second direction with respect to the injection hole. According to this embodiment, the position of the specified groove in the second direction among the partition portion can be freely set. This improves the degree of design freedom.

[0015] (8) In a head tip according to any embodiment of (7) above, it is preferable that the distance between the injection hole and the first specified groove in the second direction is equal to the distance between the injection hole and the second specified groove. According to this embodiment, the pressure fluctuations on both sides in the second direction with respect to the injection hole can be made uniform, thereby improving the injection performance.

[0016] (9) In a head tip according to any of the embodiments of (2) to (8) above, it is preferable that, among the individual flow paths, adjacent individual flow paths are designated as a first individual flow path and a second individual flow path, and among the injection holes, the injection hole communicating with the first individual flow path is designated as the first injection hole, and the injection hole communicating with the second individual flow path is designated as the second injection hole, then, of the first individual flow path, the portion located on the first side in the second direction with respect to the specified groove constitutes a first pressure chamber communicating with the first injection hole, and of the second individual flow path, the portion located on the second side in the second direction with respect to the specified groove constitutes a second pressure chamber communicating with the second injection hole. According to this embodiment, between adjacent individual flow paths, injection holes are distributed to both sides in the second direction with respect to the specified groove. That is, injection holes adjacent in the first direction are arranged alternately in the second direction. Therefore, the injection holes can be arranged in a staggered pattern without changing the tip size in the second direction. Therefore, crosstalk between adjacent pressure chambers can be suppressed. Furthermore, by arranging the pressure chambers (injection holes) in a staggered pattern, it is easier to maintain distance between injection holes arranged in the same row compared to arranging them in a single row. Therefore, when liquid is injected from the injection holes, the airflow generated between the head chip and the recording medium can be suppressed from affecting the liquid injected from surrounding injection holes. As a result, even if the gap between the head chip and the recording medium is increased, variations in the liquid's impact point can be suppressed.

[0017] (10) In the head tip according to the embodiment of (9) above, it is preferable that the dimension in the first direction of the first pressure chamber is larger than the dimension in the first direction of the portion of the first individual flow path located on the second side in the second direction with respect to the specified groove, and the dimension in the first direction of the second pressure chamber is larger than the dimension in the first direction of the portion of the second individual flow path located on the first side in the second direction with respect to the specified groove. According to this embodiment, pressure loss in each pressure chamber can be reduced while maintaining the arrangement pitch between each individual flow path. As a result, liquid can flow smoothly within the pressure chamber.

[0018] (11) 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 (10) above. According to this aspect, a highly reliable liquid spray head can be provided.

[0019] (12) 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 (11) above. According to this aspect, a highly reliable liquid jet recording device can be provided.

[0020] According to one aspect of this disclosure, a head tip can be manufactured easily and at low cost according to the required injection performance.

[0021] 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 cross-sectional view of the head chip corresponding to the V-V line in Figure 4. This is a cross-sectional view of the ejection unit corresponding to the VI-VI line in Figure 4. This is a cross-sectional view of the ejection unit corresponding to the VII-VII line in Figure 5. This is a cross-sectional view of the ejection unit corresponding to the VIII-VIII line in Figure 5. This is a cross-sectional view of the ejection unit corresponding to the IX-IX line in Figure 5. This is a bottom view of the ejection unit according to the first embodiment showing the lower surface of the actuator plate. This is a bottom view of the ejection unit according to the first embodiment showing the lower surface of the support plate. This is a plan view of the ejection unit. This is a plan view of the ejection unit according to the first embodiment showing the upper surface of the actuator plate. This is a flowchart for explaining the manufacturing method of the ejection unit according to the first embodiment. This is a process diagram for explaining the first actuator processing step, and is a cross-sectional view corresponding to Figure 5. This is a process diagram for explaining the first actuator processing step, and is a cross-sectional view corresponding to Figure 5. This is a process diagram for explaining the first support plate processing step, and is a cross-sectional view corresponding to Figure 7. This is a process diagram illustrating the first processing step of the support plate, and is a cross-sectional view corresponding to Figure 7. This is a process diagram illustrating the first processing step of the support plate, and is a cross-sectional view corresponding to Figure 7. This is a process diagram illustrating the first joining step, and is a cross-sectional view corresponding to Figure 5. This is a process diagram illustrating the second processing step of the actuator, and is a cross-sectional view corresponding to Figure 5. This is a cross-sectional view of the head tip according to the second embodiment. This is a bottom view of the discharge unit according to the second embodiment showing the lower surface of the actuator plate. This is a bottom view of the discharge unit according to the second embodiment showing the lower surface of the actuator plate.

[0022] 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.

[0023] (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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] <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.

[0030] [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).

[0031] <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.

[0032] 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.

[0033] <Head Chip 32> Figure 4 is an exploded perspective view of the head chip 32. As shown in Figure 4, the head chip 32 ejects ink from the pressure chambers 50A and 50B through nozzle holes 39A and 39B, which are separately connected to the pressure chambers 50A and 50B, in response to pressure fluctuations within the pressure chambers 50A and 50B. The head chip 32 comprises a chip module 37 and a nozzle plate 39.

[0034] 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.

[0035] As shown in Figure 4, the chip module 37 comprises an actuator plate 41 and a support plate 42. In the following description, the direction from the actuator plate 41 toward the support plate 42 (+Z side) in the Z direction may be referred to as the upper side, and the direction from the support plate 42 toward the actuator plate 41 (-Z side) may be referred to as the lower side. In the first embodiment, the lower surface of the chip module 37 is flush with the lower surface of the flow path frame member 31. The upper surface of the chip module 37 is flush with the upper surface of the flow path frame member 31.

[0036] <Actuator Plate 41> 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.

[0037] Figure 5 is a cross-sectional view of the head tip 32 corresponding to the V-V line in Figure 4. Figure 6 is a cross-sectional view of the head tip 32 corresponding to the VI-VI line in Figure 4. Figure 7 is a cross-sectional view corresponding to the VII-VII line in Figure 5. Figure 8 is a cross-sectional view corresponding to the VIII-VIII line in Figure 5. Figure 9 is a cross-sectional view corresponding to the IX-IX line in Figure 5. As shown in Figures 5 to 9, the actuator plate 41 comprises an opposing portion 45 and a partition portion 46. The opposing portion 45 is formed in a plate shape with the Z direction as the thickness direction. Each partition portion 46 protrudes downward from the opposing portion 45 and extends parallel to each other along the entire length of the opposing portion 45 in the Y direction. In the actuator plate 41, the portion surrounded by the opposing portion 45 and adjacent partition portions 46 constitutes an individual flow path 47. That is, multiple individual flow paths 47 are formed in the actuator plate 41 at intervals in the X direction. Each individual channel 47 extends linearly in the Y direction along the entire length of the actuator plate 41. The +Y side opening of each individual channel 47 is individually connected to the inlet common channel 31b. The -Y side opening of each individual channel 47 is individually connected to the outlet common channel 31c. In other words, the inlet common channel 31b and the outlet common channel 31c are connected via each individual channel 47.

[0038] Figure 10 is a bottom view of the discharge unit 30 showing the lower surface of the actuator plate 41. As shown in Figures 5 to 10, the individual flow channels 47 of the first embodiment are distinguished into a first individual flow channel 47a and a second individual flow channel 47b. The first individual flow channel 47a and the second individual flow channel 47b are arranged alternately in the X direction. The first individual flow channel 47a is formed by a first wide portion 47a1 formed on the +Y side with respect to the center in the Y direction, and a first narrow portion 47a2 formed on the -Y side with respect to the center in the Y direction. The width in the X direction of the first wide portion 47a1 is wider than the width in the X direction of the first narrow portion 47a2. The depth in the Z direction of the first wide portion 47a1 is equal to the depth in the Z direction of the first narrow portion 47a2.

[0039] The second individual channel 47b is formed by a second narrow portion 47b1 formed on the +Y side with respect to the center in the Y direction, and a second wide portion 47b2 formed on the -Y side with respect to the center in the Y direction. That is, the first individual channel 47a and the second individual channel 47b are formed with the wide portions 47a1 and 47b2 alternating with each other, and the narrow portions 47a2 and 47b1 alternating with each other. Therefore, in the part of the actuator plate 41 located on the +Y side with respect to the center in the Y direction, the first wide portion 47a1 and the second narrow portion 47b1 are arranged alternately in the X direction. In the part of the actuator plate 41 located on the -Y side with respect to the center in the Y direction, the first narrow portion 47a2 and the second wide portion 47b2 are arranged alternately in the X direction.

[0040] The dimensions of the second wide section 47b2 in each direction are the same as those of the first wide section 47a1. The dimensions of the second narrow section 47b1 in each direction are the same as those of the first narrow section 47a2. However, the dimensions in each direction may differ between the wide sections 47a1 and 47b2, and between the narrow sections 47a2 and 47b1.

[0041] A defined groove 49 is formed in the center of the actuator plate 41 in the Y direction. The defined groove 49 divides the individual flow channels 47 in the Y direction. Specifically, in the first individual flow channel 47a, the defined groove 49 divides the first wide section 47a1 and the first narrow section 47a2 in the Y direction at the boundary between them. In the second individual flow channel 47b, the defined groove 49 divides the second narrow section 47b1 and the second wide section 47b2 in the Y direction at the boundary between them. In the first embodiment, "separation" does not refer to a state in which communication between the first wide portion 47a1 and the first narrow portion 47a2 is blocked in the first individual flow path 47a, but rather to a state in which a defined groove 49 crosses between the first wide portion 47a1 and the first narrow portion 47a2. That is, the first wide portion 47a1 and the first narrow portion 47a2 are in communication via the defined groove 49.

[0042] The defined groove 49 opens on the lower surface of the actuator plate 41 and extends across each partition 46 in the X direction. Therefore, the defined groove 49 connects adjacent individual flow paths 47. The depth in the Z direction of the defined groove 49 is set to be less than the height in the Z direction of the partition 46. In the illustrated example, the depth in the Z direction of the defined groove 49 is set to be more than half the height in the Z direction of the partition 46.

[0043] The width of the defined groove 49 in the Y direction is set to a predetermined width that includes the center of the actuator plate 41 in the Y direction. In the illustrated example, the width of the defined groove 49 in the Y direction is narrower than the width of the individual flow path 47 in the X direction. The defined groove 49 extends in the X direction so as to traverse at least all of the partition portions 46. That is, the defined groove 49 does not have to be open at both end faces in the X direction of the actuator plate 41. The position of the defined groove 49 in the Y direction may be offset from the center of the actuator plate 41.

[0044] In the actuator plate 41 of the present embodiment, a first pressure chamber row 55A and a second pressure chamber row 55B are formed. The first pressure chamber row 55A is formed in a portion of the actuator plate 41 that is located on the +Y side with respect to the specified groove 49. The second pressure chamber row 55B is formed in a portion of the actuator plate 41 that is located on the -Y side with respect to the specified groove 49. Hereinafter, regarding the configuration of the pressure chamber rows 55A and 55B, the first pressure chamber row 55A will be described as an example. In the following description, among the respective pressure chamber rows 55A and 55B, for the configuration related to the first pressure chamber row 55A, an A is added to the end of the reference sign, and for the configuration related to the second pressure chamber row 55B, a B is added to the end of the reference sign, and the description of the same or corresponding configurations in the first pressure chamber row 55A row and the second pressure chamber row 55B row may be omitted. When it is not necessary to distinguish between the A row and the B row in each of the pressure chamber rows 55A and 55B, the A or B at the end of the reference sign is omitted.

[0045] As shown in FIGS. 5, 7 to 9, the first pressure chamber row 55A is configured such that pressure chambers 50A for discharging ink and non-discharge grooves 51A for not discharging ink are alternately arranged in the X direction. The pressure chamber 50A is formed in a stepped shape in which the width in the X direction of the upper portion in the cross-sectional view shown in FIG. 5 is narrower than the width in the X direction of the lower portion. In the first embodiment, the pressure chamber 50A is defined by a first wide portion 47a1 and a first recess 52A formed in the opposing portion 45.

[0046] The first recess 52A opens in a portion of the lower surface of the opposing portion 45 that faces the first wide portion 47a1. The first recess 52A extends linearly in the Y direction over the entire length of the first wide portion 47a1 in the opposing portion 45. The +Y side opening of the first recess 52A communicates separately with the inlet common flow path 31b together with the first wide portion 47a1.

[0047] The width of the first concave portion 52A in the X direction is narrower than the distance between the partition portion 46 located on the +X side (the +X side partition portion 46a) and the partition portion 46b located on the -X side (the -X side partition portion 46b) among the partition portions 46 forming one pressure chamber 50A. The first concave portion 52A is provided at a position that includes the center of the pressure chamber 50A (the first wide portion 47a1) in the X direction and does not contact the partition portions 46a and 46b. In the illustrated example, the width of the first concave portion 52A in the X direction is set to be equivalent to that of the first narrow portion 47a2 (and the second narrow portion 47b1). The depth of the first concave portion 52 in the Z direction is set to be not less than half of the thickness of the opposing portion 45 in the Z direction and not less than the height of the partition portion 46 in the Z direction. However, the depth of the first concave portion 52 in the Z direction can be changed as appropriate.

[0048] Among the non-discharge grooves 51A, the +X side non-discharge groove 51A1 located on the +X side with respect to one pressure chamber 50A is formed between the +X side partition portion 46a forming one pressure chamber 50A and the -X side partition portion 46b forming the +X side pressure chamber 50A1 located on the +X side of one pressure chamber 50A. Among the non-discharge grooves 51A, the -X side non-discharge groove 51A2 located on the -X side with respect to one pressure chamber 50A is formed between the -X side partition portion 46b forming one pressure chamber 50A and the +X side partition portion 46a forming the -X side pressure chamber 50A2 located on the -X side of one pressure chamber 50A. That is, in the first embodiment, the partition portion 46 is formed individually for each pressure chamber 50A, and the partition portion 46 is shared between adjacent pressure chambers 50A and non-discharge grooves 51A.

[0049] The non-discharge groove 51A is formed in a stepped shape in which the width in the X direction of the portion located above is narrower than the width in the X direction of the portion located below in the cross-sectional view shown in FIG. 5. In the first embodiment, the non-discharge groove 51A is defined by the second narrow portion 47b1 and the second concave portion 53A formed in the opposing portion 45.

[0050] The second recess 53A opens in the portion of the lower surface of the opposing portion 45 that faces the second narrow portion 47b1. The second recess 53A extends linearly in the Y direction along the entire length of the second narrow portion 47b1 of the opposing portion 45. The +Y side opening of the second recess 53A, together with the first narrow portion 47b1, is separately connected to the common inlet flow path 31b.

[0051] The width in the X direction of the second recess 53A is narrower than, for example, the distance between the +X side partition 46a that forms one pressure chamber 50A and the -X side partition 46b that forms the +X side pressure chamber 50A1 (see Figure 5). The width in the X direction of the second recess 53A is narrower than the width in the X direction of the first recess 52A. The depth in the Z direction of the second recess 53A is the same as the depth in the Z direction of the first recess 52A. However, the dimensions of the first recess 52A and the second recess 53A can be changed as appropriate.

[0052] In the opposing portion 45, a dividing groove 54A is formed in the portion located between the first recess 52A and the second recess 53A, which are adjacent in the X direction. The dividing groove 54A opens on the upper surface of the opposing portion 45 and extends linearly in the Y direction. Therefore, the first recess 52A, the second recess 53A, and the dividing groove 54A are arranged alternately in the X direction (offset from each other when viewed from the Z direction) and extend parallel to each other in a plan view. The length of the dividing groove 54A in the Y direction is shorter than that of the first recess 52A and the second recess 53A. The ends of the dividing groove 54A in the Y direction are not open to the end faces in the Y direction of the opposing portion 45.

[0053] As shown in Figure 5, the width of the dividing groove 54A in the X direction is formed to be less than the distance between the adjacent first recess 52A and second recess 53A. The dividing groove 54A is provided in a position that includes the center of the partition portion 46 in the X direction and does not touch the recesses 52A and 53A. In the first embodiment, the center of the dividing groove 54A in the X direction coincides with the center of the partition portion 46 in the X direction, and the width in the X direction is formed to be narrower than the width of the partition portion 46 in the X direction. Therefore, the entire dividing groove 54A overlaps the entire partition portion 46 in a plan view. The width of the dividing groove 54A may be greater than or equal to the width of the partition portion 46. Furthermore, it is sufficient that at least a portion of the partition portion 46 and the dividing groove 54A overlap each other in a plan view.

[0054] The depth in the Z-direction of the dividing groove 54A is formed to be more than half the thickness in the Z-direction of the opposing portion 45. Therefore, parts of the dividing groove 54A and recesses 52A and 53A overlap with each other when viewed from the X-direction (they overlap in the Z-direction).

[0055] Of the opposing portion 45, the portion located between the adjacent first recess 52A and dividing groove 54A in the X direction constitutes the first drive portion 59A. In a cross-sectional view perpendicular to the Y direction, the first drive portion 59A has the same thickness as the opposing portion 45. The width of the first drive portion 59A in the X direction is narrower than the recesses 52A, 53A, the dividing groove 54A, and the partition portion 46. In the illustrated example, the first drive portion 59A is provided in a position that does not overlap with the entire partition portion 46 in a plan view. However, a part of the first drive portion 59A may overlap with the partition portion 46 in a plan view.

[0056] The first drive units 59A are provided at positions corresponding to both ends in the X direction of a single pressure chamber 50A. In the following description, the first drive unit 59A located at the +X side end of the pressure chamber 50A may be referred to as the +X side first drive unit 59A1, and the first drive unit 59A located at the -X side end of the pressure chamber 50A may be referred to as the -X side first drive unit 59A2.

[0057] Of the opposing portion 45, the portion located between the adjacent second recess 53A and dividing groove 54A in the X direction constitutes the second drive portion 69A. In a cross-sectional view perpendicular to the Y direction, the second drive portion 69A has the same thickness as the opposing portion 45. The width of the second drive portion 69A in the X direction is narrower than the recesses 52A, 53A, the dividing groove 54A, and the partition portion 46. In the illustrated example, the second drive portion 69A is provided in a position that does not overlap with the entire partition portion 46 in a plan view. However, a part of the second drive portion 69A may overlap with the partition portion 46 in a plan view.

[0058] The second drive units 69A are provided at positions corresponding to both ends in the X direction for each pressure chamber 50A. In the following description, the second drive unit 69A located between the +X side non-discharge groove 51A1 and the pressure chamber 50A may be referred to as the +X side second drive unit 69A1. The second drive unit 69A located between the -X side non-discharge groove 51A2 and the pressure chamber 50A may be referred to as the -X side second drive unit 69A2.

[0059] As shown in Figures 6 to 9, the second pressure chamber row 55B has a configuration in which pressure chambers 50B and non-discharge grooves 51B are alternately arranged in the X direction. Specifically, the pressure chamber 50B is defined by a second wide section 47b2 and a first recess 52B. The pressure chamber 50B faces the non-discharge groove 51A (second narrow section 47b1) in the Y direction, with a specified groove 49 in between. That is, of the second individual flow paths 47b, the -Y side with respect to the specified groove 49 functions as the pressure chamber 50B. Of the second individual flow paths 47b, the +Y side with respect to the specified groove 49 functions as the non-discharge groove 51A. The non-discharge groove 51B is defined by a first narrow section 47b1 and a second recess 53B. The non-discharge groove 51B faces the pressure chamber 50A (first wide section 47a1) in the Y direction, with a specified groove 49 in between. In other words, of the first individual flow path 47a, the +Y side with respect to the specified groove 49 functions as a pressure chamber 50A. Of the first individual flow path 47a, the -Y side with respect to the specified groove 49 functions as a non-discharge groove 51B.

[0060] Thus, the pressure chambers 50A of the first pressure chamber row 55A and the pressure chambers 50B of the second pressure chamber row 55B are arranged with a half-pitch offset relative to the arrangement pitch of adjacent pressure chambers 50A (or pressure chambers 50B). Similarly, the non-discharge grooves 51A of the first pressure chamber row 55A and the non-discharge grooves 51B of the second pressure chamber row 55B are also arranged with a half-pitch offset relative to the arrangement pitch of adjacent non-discharge grooves 51A (or non-discharge grooves 51B). Therefore, the pressure chambers 50A of the first pressure chamber row 55A and the pressure chambers 50B of the second pressure chamber row 55B, as well as the non-discharge grooves 51A of the first pressure chamber row 55A and the non-discharge grooves 51B of the second pressure chamber row 55B, are arranged in a staggered (alternating) pattern.

[0061] The -Y side opening of the first recess 52B is separately connected to the common outlet channel 31c together with the second wide portion 47b2. The -Y side opening of the second recess 53B is separately connected to the common outlet channel 31c together with the first wide portion 47a2.

[0062] <Support Plate 42> As shown in Figures 5 to 9, the support plate 42 ensures the rigidity of the chip module 37. The support plate 42 is stacked on the actuator plate 41, thereby supporting the actuator plate 41 from above. The support plate 42 is a plate-like structure formed to have the same planar external shape as the actuator plate 41. The support plate 42 is fixed to the upper surface of the actuator plate 41 (opposing portion 45) by adhesive 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 made of, for example, metal, metal oxide, glass, resin, ceramics, etc.

[0063] Figure 11 is a bottom view of the discharge unit 30 showing the lower surface of the support plate 42. As shown in Figures 5, 6, and 11, a deformation-allowing portion 60A is formed on the support plate 42 at a position that overlaps with at least a part of the first drive unit 59A in a plan view. The deformation-allowing portion 60A is a groove that opens on the lower surface of the support plate 42. In a plan view, the deformation-allowing portion 60A extends linearly in the Y direction along the pressure chamber 50A to the portions located at both ends (outer circumference) of the pressure chamber 50A in the X direction. Specifically, the deformation-allowing portion 60A located on the +X side is formed in the X direction to span (overlap in a plan view) the entirety of the +X side first drive unit 59A1, the dividing groove 54A, and the +X side second drive unit 69A1 corresponding to one pressure chamber 50A. Of the deformation-allowable portions 60A, the deformation-allowable portion 60A located on the -X side is formed in the X direction to span across (overlap in plan view) the entirety of the -X side first drive portion 59A2, the dividing groove 54A, and the -X side second drive portion 69A2 corresponding to one pressure chamber 50A. Therefore, in the cross-sectional view shown in Figure 5, the first drive portion 59A, the second drive portion 69A, and the dividing groove 54A are not in contact with the support plate 42.

[0064] As shown in Figures 7 to 9, the length of the deformation-allowable portion 60A in the Y direction is shorter than the length of the pressure chamber 50A in the Y direction. That is, both ends of the deformation-allowable portion 60A in the Y direction are not open to the end faces of the support plate 42 in the Y direction. In the Y direction, the deformation-allowable portion 60A is formed to be the same length as the dividing groove 54A. In a plan view, the deformation-allowable portion 60A overlaps with the entire Y direction of the dividing groove 54A. Therefore, in the cross-sectional view shown in Figures 7 to 9, the first drive unit 59A, the second drive unit 69A, and the dividing groove 54A are not in contact with the support plate 42. However, the dimensions of the deformation-allowable portion 60A can be changed as appropriate.

[0065] As shown in Figures 7 to 9, the support plate 42 has a common conductive portion 61A and individual conductive portions 62A. The common conductive portion 61A is provided at the +Y side end of the support plate 42. The individual conductive portion 62A is provided at the -Y side end of the support plate 42.

[0066] The common conductive portion 61A is formed in the support plate 42 in the portion located on the +Y side with respect to the deformation-tolerant portion 60A. The common conductive portion 61A includes a common recess 65A and a common wiring groove 66A. The common recess 65A opens on the upper surface of the support plate 42. The common recess 65 constitutes the upper end opening of the common conductive portion 61A. Multiple common recesses 65A are provided at intervals in the X direction.

[0067] The common wiring groove 66A opens on the lower surface of the support plate 42 and extends linearly in the X direction. That is, the common wiring groove 66A constitutes the lower end opening of the common conductive portion 61A. The common wiring groove 66A is provided to traverse the X direction between a plurality of common recesses 65A. The common wiring groove 66A communicates with each common recess 65A through a portion that overlaps with the common recess 65A in a plan view. The portion of the common conductive portion 61A that communicates with the common recess 65A and the common wiring groove 66A constitutes a common through-hole 67A that penetrates the support plate 42 in the Z direction. Note that the common wiring groove 66A is not limited to spanning all common recesses 65A, but only needs to span between at least adjacent common recesses 65A.

[0068] The individual conductive portion 62A 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 60A. The individual conductive portion 62A includes an individual recess 70A and an individual wiring groove 71A. The individual recess 70A is open on the upper surface of the support plate 42. The individual recess 70A constitutes the upper end opening of the individual conductive portion 62A. Multiple individual recesses 70A are provided at intervals in the X direction. In the first embodiment, the common recess 65A and the individual recesses 70A are arranged at different positions in the Y direction and alternately in the X direction. However, the position of the common recess 65A relative to the individual recesses 70A can be changed as appropriate.

[0069] The individual wiring groove 71A opens on the lower surface of the support plate 42 and extends linearly in the X direction. That is, the individual wiring groove 71A constitutes the lower end opening of the individual conductive portion 62A. The individual wiring groove 71A is provided so as to traverse the X direction between the multiple individual recesses 70A. The individual wiring groove 71A communicates with each individual recess 70A through a portion that overlaps with the individual recess 70A in a plan view. The portion of the individual conductive portion 62A that communicates with the individual recess 70A and the individual wiring groove 71A constitutes an individual penetration portion 73A that penetrates the support plate 42 in the Z direction. Note that the individual wiring groove 71A is not limited to spanning all individual recesses 70A, but only needs to span between at least adjacent individual recesses 70A.

[0070] <Nozzle Plate 39> As shown in Figures 5 to 9, 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 actuator plate 41 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, the individual flow paths 47a and 47b, and the lower end openings of the specified groove 49 together. The nozzle plate 39 is formed from a metal material (such as SUS or Ni-Pd). However, the nozzle plate 39 may be made from a resin material (such as polyimide), glass, silicon, etc., in addition to a metal material.

[0071] The nozzle plate 39 has a plurality of nozzle holes 39A and 39B that penetrate the nozzle plate 39 in the Z direction. The nozzle holes 39A and 39B 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 pressure chamber 50A in a plan view. Each nozzle hole 39B overlaps with each pressure chamber 50B in a plan view. That is, each nozzle hole 39A and 39B communicates separately with the corresponding pressure chambers 50A and 50B. On the other hand, the nozzle holes 39A and 39B do not communicate with the non-discharge grooves 51A and 51B.

[0072] Next, the various wirings formed on the head chip 32 will be described. As shown in Figures 5 and 6, the head chip 32 is equipped with common wirings 81A and 81B and individual wirings 82A and 82B as drive wirings. In the following, the common wirings 81A and individual wirings 82A corresponding to the first pressure chamber row 55A will be described as an example, and the description of the common wirings 81B and individual wirings 82B corresponding to the second pressure chamber row 55B will be omitted as appropriate.

[0073] As shown in Figures 5, 9, and 10, the common wiring 81A includes a first common electrode 81Aa, a second common electrode 81Ab, an end-face routing wiring 81Ac, an upper-face routing wiring 81Ad, a through-hole wiring 81Ae, and a common pad 81Af.

[0074] The first common electrode 81Aa is formed on the inner surface of at least each first recess 52A on the lower surface of the opposing portion 45. In the illustrated example, the first common electrode 81Aa is formed over the entire inner surface of the first recess 52A. That is, the entire first common electrode 81Aa faces into the pressure chamber 50A. The second common electrode 81Ab is formed on the inner surface of at least each second recess 53A on the lower surface of the opposing portion 45. In the illustrated example, the second common electrode 81Ab is formed over the entire inner surface of the second recess 53A. That is, the entire second common electrode 81Ab faces into the non-discharge groove 51A.

[0075] The end face routing wiring 81Ac is formed on the +Y side end face of the opposing portion 45. In the first embodiment, the end face routing wiring 81Ac is formed over the entire +Y side end face of the opposing portion 45. The end face routing wiring 81Ac is connected to the first common electrode 81Aa and the second common electrode 81Ab at the boundary between the lower surface of the opposing portion 45 and the +Y side end face. The upper surface routing wiring 81Ad is formed on the +Y side end of the upper surface of the opposing portion 45. The upper surface routing wiring 81Ad is formed in a strip shape extending in the X direction on the upper surface of the opposing portion 45. The upper surface routing wiring 81Ad is connected to the end face routing wiring 81Ac at the boundary between the upper surface of the opposing portion 45 and the +Y side end face. The upper surface routing wiring 81Ad is separated in the Y direction from the dividing groove 54A.

[0076] The through-wiring 81Ae is for connecting the upper surface routing wiring 81Ad and the common pad 81Af. The through-wiring 81Ae is provided so as to pass through the support plate 42. The through-wiring 81Ae is formed on the inner surface of the common through-hole 67A. The through-wiring 81Ae is connected to the upper surface routing wiring 81Ad at the lower end edge of the common through-hole 67A. Note that it is sufficient for the through-wiring 81Ae to have conductivity along the entire length in the Z direction of the inner surface of the common through-hole 67A. That is, the through-wiring 81Ae may be formed over the entire circumferential surface of the inner surface of the common through-hole 67A, or it may be formed only on a part of the circumferential surface.

[0077] Figure 12 is a plan view of the discharge unit 30. As shown in Figures 4 and 12, the common pad 81Af is formed on the upper surface of the support plate 42. The common pad 81Af is connected to the through wiring 81Ae at the upper end opening edge of the common through portion 67A.

[0078] Figure 13 is a plan view of the discharge unit 30 showing the upper surface of the actuator plate 41. As shown in Figures 5, 7, and 13, the individual wiring 82A includes an upper surface first individual electrode 82Aa, an upper surface second individual electrode 82Ab, an upper surface third individual electrode 82Ac, a grooved first individual electrode 82Ad, a grooved second individual electrode 82Ae, an upper surface routing wiring 82Af, a through wiring 82Ag, and an individual pad 82Ah.

[0079] The upper surface first individual electrodes 82Aa are each formed on the upper surface of the opposing portion 45 in a portion that overlaps with each pressure chamber 50 in a plan view. In the first embodiment, the upper surface first individual electrodes 82Aa are formed on the upper surface of the opposing portion 45 in a portion that overlaps with the first recess 52A in a plan view. Therefore, the upper surface first individual electrodes 82Aa face the first common electrode 81Aa in the Z direction with the opposing portion 45 in between. On the upper surface of the opposing portion 45, the +Y side end of the upper surface first individual electrode 82Aa is separated from the upper surface routing wiring 81Ad.

[0080] The upper second individual electrodes 82Ab are formed on the upper surface of the opposing portion 45 in a portion that overlaps with the +X side non-discharge groove 51A1 in a plan view. In the first embodiment, the upper second individual electrodes 82Ab are formed on the upper surface of the opposing portion 45 in a portion that overlaps with the -X side end of the second recess 53A in a plan view. Therefore, the upper second individual electrodes 82Ab face the second common electrode 81Ab formed on the inner surface of the +X side non-discharge groove 51A1 in the Z direction with the opposing portion 45 in between. On the upper surface of the opposing portion 45, the +Y side end of the upper second individual electrode 82Ab is separated from the upper routing wiring 81Ad.

[0081] The upper third individual electrodes 82Ac are formed on the upper surface of the opposing portion 45 in a portion that overlaps with the -X side non-discharge groove 51A2 in a plan view. In the first embodiment, the upper third individual electrodes 82Ac are formed on the upper surface of the opposing portion 45 in a portion that overlaps with the +X side end of the second recess 53A in a plan view. Therefore, the upper third individual electrodes 82Ac face the second common electrode 81Ab formed on the inner surface of the -X side non-discharge groove 51A2 in the Z direction with the opposing portion 45 in between. On the upper surface of the opposing portion 45, the +Y side end of the upper third individual electrode 82Ac is separated from the upper surface routing wiring 81Ad.

[0082] The first individual electrode 82Ad of the groove is formed on the inner surface of the dividing groove 54A (+X side dividing groove 54A1) located on the +X side with respect to the pressure chamber 50A. The second individual electrode 82Ab is formed over the entire inner surface of the +X side dividing groove 54A1. Therefore, the first individual electrode 82Ad of the groove faces the first common electrode 81Aa with the +X side first drive unit 59A1 in between. The first individual electrode 82Ad of the groove faces the second common electrode 81Ab, which is formed on the inner surface of the +X side non-discharge groove 51A1, with the +X side second drive unit 69A1 in between.

[0083] The grooved second individual electrode 82Ae is formed on the inner surface of the dividing groove 54A (-X side dividing groove 54A2) located on the -X side with respect to the pressure chamber 50A. The grooved second individual electrode 82Ae is formed over the entire inner surface of the -X side dividing groove 54A2. Therefore, the grooved second individual electrode 82Ae faces the first common electrode 81Aa with the -X side first drive unit 59A2 in between. The grooved second individual electrode 82Ae faces the second common electrode 81Ab, which is formed on the inner surface of the -X side non-discharge groove 51b, with the -X side second drive unit 69A2 in between.

[0084] As shown in Figure 13, the top surface routing wiring 82Af connects the top surface first individual electrode 82Aa, top surface second individual electrode 82Ab, top surface third individual electrode 82Ac, groove first individual electrode 82Ad, and groove second individual electrode 82Ae, which are provided on the upper surface of the opposing portion 45 corresponding to one pressure chamber 50A. The top surface routing wiring 82Af extends in a strip shape in the X direction on the upper surface of the opposing portion 45.

[0085] As shown in Figures 7 to 9, the through-wiring 82Ag is for connecting the upper surface routing wiring 82Af and the individual pads 82Ah. The through-wiring 82Ag is provided so as to penetrate the support plate 42. The through-wiring 82Ag is formed on the inner surface of the individual through-part 73A. The through-wiring 82Ag is connected to the upper surface routing wiring 82Af at the lower end edge of the individual through-part 73A. Note that it is sufficient for the through-wiring 82Ag to have conductivity along the entire length in the Z direction on the inner surface of the individual through-part 73A. That is, the through-wiring 82Ag may be formed over the entire circumferential surface of the inner surface of the individual through-part 73A, or it may be formed only on a part of the circumferential surface.

[0086] As shown in Figures 4 and 12, the individual pads 82Ah are formed on the upper surface of the support plate 42. The individual pads 82Ah are connected to the through-wiring 82Ag at the upper end opening edge of the individual through-port 73A.

[0087] <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.

[0088] 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 pads 81Af, 81Bf and the individual pads 82Ah, 82Bh on the upper surface of the support plate 42.

[0089] 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.

[0090] 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 common pads 81Af, 81Bf and individual pads 82Ah, 82Bh 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.

[0091] [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.

[0092] 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.

[0093] 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 individual channel 47. Of the ink distributed to each individual channel 47, the ink distributed to the first individual channel 47a is discharged to the common outlet channel 31c through the pressure chamber 50A and the non-discharge groove 51B. Of the ink distributed to each individual channel 47, the ink distributed to the second individual channel 47b is discharged to the common outlet channel 31c through the non-discharge groove 51A and the pressure chamber 50B. 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.

[0094] 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 via the flexible printed circuit board 35 between the common electrodes 81Aa, 81Ab and the individual electrodes 82Aa to 82Ae, and between the common electrodes 81Ba, 81Bb and the individual electrodes 82Ba to 82Be. At this time, the common electrodes 81Aa, 81Ab, 81Ba, and 81Bb are set to a reference potential GND, and the individual electrodes 82Aa to 82Ae and 82Ba to 82Be are set to a drive potential Vdd when the drive voltage is applied. As a result, a potential difference is generated between the common electrodes 81Aa, 81Ab and the individual electrodes 82Aa to 82Ae, and between the common electrodes 81Ba, 81Bb and the individual electrodes 82Ba to 82Be, which are facing each other across the opposing part 45, and an electric field is generated in the opposing part 45.

[0095] For example, in the first pressure chamber row 55A, a potential difference is generated in the Z direction between the first common electrode 81Aa and the upper surface first individual electrode 82Aa. Due to the potential difference generated in the Z direction, an electric field is generated in the opposing portion 45 in a direction parallel to the polarization direction (Z direction). As a result, the opposing portion 45 expands and contracts in the Z direction by the bend mode. A potential difference is generated in the X direction between the first common electrode 81Aa and the grooved first individual electrode 82Ad, and between the first common electrode 81Aa and the grooved second individual electrode 82Ae. Due to the potential difference generated in the X direction, an electric field is generated in the first drive unit 59A, causing the first drive unit 59A to undergo thickness sliding deformation in the Z direction by the shear mode. As a result, the portion of the opposing portion 45 corresponding to each pressure chamber 50A undergoes shear deformation upward from both ends in the X direction towards the center.

[0096] A potential difference is generated in the Z direction between the second common electrode 81Ab and the upper second individual electrode 82Ab. Due to the potential difference generated in the Z direction, the opposing portion 45 expands and contracts in the Z direction by the bend mode. In addition, a potential difference is generated in the X direction between the second common electrode 81Ab and the groove first individual electrode 82Ad, and between the second common electrode 81Ab and the groove second individual electrode 82Ae. Due to the potential difference generated in the X direction, an electric field is generated in the second drive unit 69A, causing the second drive unit 69A to undergo thickness sliding deformation in the Z direction by the shear mode. As a result, the portions of the opposing portion 45 corresponding to each non-discharge groove 51A undergo shear deformation upward from both ends in the X direction towards the center.

[0097] 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 45) deforms so that the volume inside the pressure chamber 50A (wide portion 47a1) expands. Then, when the drive voltage is reduced to zero, the opposing portion 45 returns to its original state, causing the volume inside the pressure chamber 50A (wide portion 47a1) 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 50A increases, and the ink inside the pressure chamber 50A is ejected to the outside through the nozzle hole 39A. When the ink ejected to the outside lands on the recording medium P, the print information is recorded on the recording medium P. Also, a pressure fluctuation occurs in the pressure chamber 50B through an operation similar to the one described above, causing ink to be ejected through the nozzle hole 39B.

[0098] <Manufacturing Method of Discharge Unit 30> Next, the manufacturing method of the discharge unit 30 described above will be explained. Figure 14 is a flowchart illustrating the manufacturing method of the discharge unit 30. As shown in Figure 14, the manufacturing method of the discharge unit 30 comprises 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, an assembly step S16, and a second joining step S17. For convenience, the following explanation will use the case where the chip module 37 is manufactured at the chip level as an example.

[0099] Figures 15 and 16 are process diagrams illustrating the first actuator machining process S11, and are cross-sectional views corresponding to Figure 5. Note that in the first actuator machining process S11, the cross-section corresponding to Figure 6 is performed in the same manner as the cross-section corresponding to Figure 5, and therefore is not shown. In the first actuator machining process S11, as shown in Figure 15, a dividing groove 54A is formed in the actuator plate 41 (dividing groove formation process). Specifically, the dividing groove 54A is formed by dicing or the like on the upper surface of the actuator plate 41.

[0100] Next, in the first actuator processing step S11, as shown in Figure 16, the portion of the drive wiring located on the upper surface of the actuator plate 41 (individual electrodes 82Aa to 82Ae and upper surface routing wiring 81Ad, 82Af, 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 54A.

[0101] Figures 17 to 19 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 17, in the first processing step S12 of the support plate, conductive portions 61A, 61B, 62A, and 62B are first formed on the support plate 42. Specifically, common recesses 65A, 65A and individual recesses 70A, 70B are formed on the upper surface of the support plate 42 by sandblasting or the like. Subsequently, as shown in Figure 18, common wiring grooves 66A, 66B and individual wiring grooves 71A, 71B are formed on the lower surface of the support plate 42 by dicing or the like. At this time, the common wiring grooves 66A, 66B and common recesses 65A, 65B are formed so that they communicate with each other, and the individual wiring grooves 71A, 71B and individual recesses 70A, 70B are formed so that they communicate with each other. This forms conductive portions 61A, 61B, 62A, and 62B.

[0102] Next, in the first processing step S12 of the support plate, deformation-tolerant portions 60A and 60B are formed as shown in Figure 19. The deformation-tolerant portions 60A and 60B are formed on the lower surface of the support plate 42 by dicing or the like.

[0103] Figure 20 is a process diagram illustrating the first joining process S13, and is a cross-sectional view corresponding to Figure 5. Note that in the first joining process S13, the cross-section corresponding to Figure 6 is performed in the same manner as the cross-section corresponding to Figure 5, so it is not shown. As shown in Figure 20, 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 grooves 66A, 66B, the individual wiring grooves 71A, 71B, and the deformation-allowing sections 60A, 60B.

[0104] Figure 21 is a process diagram illustrating the second actuator processing step S14, and is a cross-sectional view corresponding to Figure 5. Note that in the second actuator processing step S14, the cross-section corresponding to Figure 6 is performed in the same way as the cross-section corresponding to Figure 5, so it is not shown. In the second actuator processing step S14, the lower surface of the actuator plate 41 is processed as shown in Figure 21. In the second actuator processing step S14, first, recesses that will become the first recess 52A and the second recess 53A of the pressure chamber 50A and non-discharge groove 51A are formed on the lower surface of the actuator plate 41 by dicing or the like. Next, the parts of the drive wiring located on the lower surface of the actuator plate 41 and the +Y side end face (common electrodes 81Aa, 81Ab and end face routing wiring 81Ac, etc.) are formed, for example, by vapor deposition (second wiring formation step). After that, the parts of the pressure chamber 50A and non-discharge groove 51A that correspond to, for example, the individual flow path 47 are formed on the lower surface of the actuator plate 41 by dicing or the like.

[0105] 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.

[0106] In the second support plate processing step S15, through-wirings 81Ae, 82Ag and pads 81Af, 82Ah 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 81Ae, 82Ag and pads 81Af, 82Ah. 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 81Ae, 82Ag and pads 81Af, 82Ah.

[0107] In assembly step S16, 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.

[0108] In the second joining step S17, 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.

[0109] As described above, the head chip 32 of the first embodiment includes an actuator plate (flow channel defining section) 41 having a plurality of partition sections 46 spaced apart in the X direction (first direction), and forming a plurality of individual flow channels 47 between adjacent partition sections 46 through which ink can flow in the Y direction (second direction), and an opposing section (actuator section) 45 of the actuator plate 41 that is superimposed on the partition sections 46 in the Z direction (third direction) and is deformable to expand or contract the inside of the individual flow channels 47. A defined groove 49 is formed in a part of the partition section 46 in the Y direction, which connects the inside of one individual flow channel 47 to the outside of one individual flow channel 47. Among the individual flow channels 47, a nozzle hole (injection hole) 39a is formed that communicates with a position shifted in the Y direction from the defined groove 49, and a nozzle plate (injection hole plate) 39 is provided facing the opposing section 45. With this configuration, the inside and outside of the individual flow channels 47 are connected by a specified groove 49, so that pressure fluctuations generated in the individual flow channels 47 due to the deformation of the opposing part 45 are released to the outside of the individual flow channels 47 through the specified groove 49. That is, of the individual flow channels 47, the part located on the nozzle hole 39A, 39B side with respect to the specified groove 49 in the Y direction functions as pressure chambers 50A, 50B capable of ejecting ink, while the part located on the opposite side of the nozzle hole 39A, 39B side with respect to the specified groove 49 in the Y direction functions as non-ejection grooves 51A, 51B (no longer functions as a pressure chamber). As a result, the length (pump length) of the pressure chambers 50A, 50B can be adjusted without changing the dimensions of the actuator plate 41 in the Y direction, and the ejection performance of the ink ejected through the nozzle holes 39A, 39B can be adjusted. Therefore, it is not necessary to manufacture head tips 32 with dimensions corresponding to the ejection performance. Thus, head tips 32 corresponding to the required ejection performance can be manufactured simply and at low cost.

[0110] In the head chip 32 according to the first embodiment, the defined groove 49 extends linearly in the X direction and connects adjacent individual flow channels 47. With this configuration, by forming the defined groove 49 so as to connect adjacent individual flow channels 47, the defined groove 49 can be formed collectively on the partition portion 46 by, for example, dicing. This makes it possible to further improve manufacturing efficiency.

[0111] In the head chip 32 according to the first embodiment, the opposing portion 45 is provided with a drive electrode that generates an electric field on the opposing portion 45. On the lower surface (first surface) of the opposing portion 45, only electrodes of the same polarity (common electrodes 81Aa, 81Ba) of the drive electrode are formed. With this configuration, since only electrodes of the same polarity are formed on the lower surface of the opposing portion 45, the increase in the risk of short circuits due to the addition of the specified groove 49 can be suppressed.

[0112] In the head chip 32 according to the first embodiment, the drive electrodes formed on the lower surface of the opposing portion 45 are common electrodes 81Aa and 81Ba that are at a reference potential GND. With this configuration, even if the common electrodes 81Aa and 81Ba provided in adjacent individual flow channels 47 come into contact with each other via ink, no potential difference is generated between the electrodes, thus suppressing short circuits of the drive electrodes.

[0113] In the head chip 32 according to the first embodiment, an inlet common channel 31b and an outlet common channel 31c are provided on both sides in the Y direction relative to the individual channels 47, extending in the X direction and communicating with a plurality of individual channels 47. The specified groove 49 is provided in the partition portion 46 at a position separated in the Y direction from the common channels 31b and 31c. With this configuration, the position of the specified groove 49 in the Y direction within the partition portion 46 can be easily set. This improves the degree of design freedom.

[0114] In the head tip 32 according to the first embodiment, adjacent individual flow paths 47 are designated as the first individual flow path 47a and the second individual flow path 47b, respectively. Of the nozzle holes 39A and 39B, the nozzle hole communicating with the first individual flow path 47a is designated as the nozzle hole (first injection hole) 39A, and the nozzle hole communicating with the second individual flow path 47b is designated as the nozzle hole (second injection hole) 39B. The portion of the first individual flow path 47a located on the +Y side (first side in the second direction) with respect to the specified groove 49 constitutes a pressure chamber (first pressure chamber) 50A communicating with the nozzle hole 39A. The portion of the second individual flow path 47b located on the -Y side (second side in the second direction) with respect to the specified groove 49 constitutes a pressure chamber (second pressure chamber) 50B communicating with the nozzle hole 39B. In this configuration, nozzle holes 39A and 39B are distributed to both sides in the Y direction relative to the specified groove 49 between adjacent individual flow paths 47. That is, nozzle holes 39A and 39B adjacent in the X direction are arranged alternately in the Y direction. Therefore, the nozzle holes 39A and 39B can be arranged in a staggered pattern without changing the tip size in the Y direction. As a result, crosstalk between adjacent pressure chambers 50A and 50B can be suppressed. In addition, by arranging the pressure chambers 50A and 50B (nozzle holes 39A and 39B) in a staggered pattern, it is easier to secure the distance between nozzle holes arranged on the same pressure chamber row 55A and 55B than if the nozzle holes were arranged in a single row. Therefore, when ink is ejected from the nozzle holes 39A and 39B, the airflow generated between the head tip 32 and the recording medium P can be suppressed from affecting the ink ejected from the surrounding nozzle holes 39A and 39B. This makes it possible to suppress variations in the ink's landing position, even if the gap between the print head 32 and the recording medium P is increased.

[0115] In the head chip 32 according to the first embodiment, the dimension in the X direction of the pressure chamber 50A (wide section 47a1) is larger than the dimension in the X direction of the non-discharge groove 51B (narrow section 47a2), and the dimension in the X direction of the pressure chamber 50B (wide section 47b2) is larger than the dimension in the X direction of the non-discharge groove 51A (narrow section 47b1). With this configuration, pressure loss within each pressure chamber 50A, 50B can be reduced while maintaining the arrangement pitch between each individual flow path 47. As a result, ink can flow smoothly within the pressure chambers 50A, 50B.

[0116] 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.

[0117] (Second Embodiment) Figure 22 is a cross-sectional view of the head tip 32 according to the second embodiment. Figure 23 is a bottom view of the discharge unit 30 according to the third embodiment, showing the lower surface of the actuator plate 41. The head tip 32 of the second embodiment differs from the embodiment described above in that the pressure chamber row 55 is in a single row. In the head tip 32 shown in Figures 22 and 23, the dimensions of the multiple individual flow paths 47 are set to be the same in each direction. In the second embodiment, the nozzle hole 39a is provided at a position that overlaps with the center of each individual flow path 47 in the Y direction in a plan view.

[0118] As shown in Figure 23, the actuator plate 41 has a first defined groove 149A and a second defined groove 149B formed at both ends in the Y direction. The first defined groove 149A is provided in the portion of the individual flow path 47 located on the +Y side with respect to the nozzle hole 39a. The first defined groove 149A opens on the lower surface of the actuator plate 41 and extends across each partition portion 46 in the X direction. Therefore, the first defined groove 149A connects adjacent individual flow paths 47.

[0119] The second regulating groove 149B is provided in the portion of the individual flow path 47 located on the -Y side with respect to the nozzle hole 39a. The second regulating groove 149B opens on the lower surface of the actuator plate 41 and extends across each partition portion 46 in the X direction. Therefore, the second regulating groove 149B connects adjacent individual flow paths 47. The dimensions in each direction of the first regulating groove 149A and the second regulating groove 149B are set to be the same. However, the dimensions between the first regulating groove 149A and the second regulating groove 149B may be different.

[0120] In the head tip 32, the pressure chamber row 55 is composed of pressure chambers 50 arranged in the X direction. The pressure chamber 50 is formed by the portion of the individual flow path 47 and the first recess 52 located between the first specified groove 149A and the second specified groove 149B. That is, the portion of the individual flow path 47 and the first recess 52 located outward in the Y direction relative to each specified groove 149A, 149B functions as a non-pressure chamber separated from the pressure chamber 50. In the illustrated example, the Y-direction dimension from the nozzle hole 39a to the first specified groove 149A is equal to the Y-direction dimension from the nozzle hole 39a to the second specified groove 149B. That is, the nozzle hole 39a is located at the center in the Y direction relative to the pressure chamber 50. Note that a non-discharge groove that does not communicate with the nozzle hole 39a may be formed between adjacent pressure chambers 50.

[0121] In the head tip 32 of the second embodiment, the inside and outside of the individual flow path 47 are connected by specified grooves 149A and 149B, so that pressure fluctuations generated in the individual flow path 47 due to the deformation of the opposing part 45 are released to the outside of the individual flow path 47 through the specified grooves 149A and 149B. That is, of the individual flow path 47, the part located on the nozzle hole 39a side with respect to the specified grooves 149A and 149B in the Y direction functions as a pressure chamber 50 capable of ejecting ink, and the part located on the opposite side of the specified grooves 149A and 149B in the Y direction from the nozzle hole 39a side functions as a non-pressure chamber (it ceases to function as a pressure chamber). As a result, the length of the pressure chamber 50 (pump length) can be adjusted without changing the dimensions of the actuator plate 41 in the Y direction, and the ejection performance of the ink ejected through the nozzle hole 39a can be adjusted. Therefore, it is not necessary to manufacture head tips 32 with dimensions corresponding to the required ejection performance. Thus, head tips 32 corresponding to the required ejection performance can be manufactured easily and at low cost. Furthermore, a shorter pressure chamber 50 tends to accommodate higher ejection frequencies and more easily eject ink droplets with small drop volumes. A longer pressure chamber 50 tends to eject ink droplets with larger drop volumes.

[0122] In the head tip 32 of the second embodiment, the defined groove includes a first defined groove 149A provided on the +Y side with respect to the nozzle hole 39a, and a second defined groove 149B provided on the -Y side with respect to the nozzle hole 39a. With this configuration, the positions of the defined grooves 149A and 149B in the Y direction of the partition portion 46 can be freely set. This improves the degree of design freedom.

[0123] In the head tip 32 of the second embodiment, the distance between the nozzle hole 39a and the first groove 149A in the Y direction is equal to the distance between the nozzle hole 39a and the second groove 149B. With this configuration, pressure fluctuations on both sides in the Y direction with respect to the nozzle hole 39a can be made uniform, thereby improving discharge performance. However, the distance between the nozzle hole 39a and the first groove 149A and the distance between the nozzle hole 39a and the second groove 149B in the Y direction may be different from each other.

[0124] (Third Embodiment) Figure 24 is a bottom view of the discharge unit 30 according to the third embodiment, showing the lower surface of the actuator plate 41. In the head tip 32 shown in Figure 24, the +Y side end of the first regulating groove 149A is open to the +Y side end face of the actuator plate 41. That is, the first regulating groove 149A is in communication with the inlet common flow path 31b. The -Y side end of the second regulating groove 149B is open to the -Y side end face of the actuator plate 41. That is, the second regulating groove 149B is in communication with the outlet common flow path 31c.

[0125] This configuration allows for an increase in the cross-sectional area of ​​the individual flow channels 47 at the connection points with the common flow channels 31b and 31c, thereby reducing pressure loss at the connection points and enabling smooth ink flow between the common flow channels 31b and 31c and the individual flow channels 47.

[0126] (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.

[0127] In the embodiments described above, a configuration in which the Z direction coincides with the direction of gravity was explained, but the configuration is not limited to this, and the Z direction may be aligned with the horizontal direction.

[0128] In the above-described embodiment, a configuration was described in which common electrodes 81a and 81b are formed on the lower surface of the actuator plate 41 and individual electrodes 82a to 82e are formed on the upper surface of the actuator plate 41. However, the configuration is not limited to this. Individual electrodes may be formed on the lower surface of the actuator plate 41 and common electrodes may be formed on the upper surface of the actuator plate 41. Furthermore, common electrodes and individual electrodes may be formed side by side on the same surface of the actuator plate 41. In the above-described embodiment, a configuration was described in which the actuator plate 41 is deformed by both bend mode and shear mode. However, the configuration is not limited to this. The actuator plate 41 only needs to be deformed by at least shear mode.

[0129] In the embodiments described above, a configuration in which the opposing portion 45 and the partition portion 46 are integrally formed has been described, but the configuration is not limited to this. The opposing portion 45 and the partition portion 46 may be formed separately. In this case, the actuator portion may be formed by the actuator plate 41, and the flow path defining portion may be formed by the flow path plate stacked on the actuator plate 41. In the embodiments described above, a configuration in which a defined groove connects adjacent individual flow paths has been described, but the configuration is not limited to this. The defined groove may connect individual flow paths and a common flow path (outside the individual flow paths).

[0130] In the embodiments described above, a configuration in which one or two defined grooves communicate with one individual flow path was described, but the configuration is not limited to this. Three or more defined grooves may be formed. In the embodiments described above, a configuration in which one side of one individual flow path 47 is a pressure chamber with respect to the defined groove 49 and the other side is a non-discharge groove was described, but the configuration is not limited to this. Both sides of the defined groove 49 may be pressure chambers. Furthermore, one individual flow path 47 may be divided into three or more pressure chambers (or non-discharge grooves).

[0131] 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.

[0132] 1: Printer (liquid jet recording device) 5: Inkjet head (liquid jet head) 31b: Inlet common channel (common channel) 31c: Outlet common channel (common channel) 32: Head tip 39: Nozzle plate (jet hole plate) 39a: Nozzle hole (jet hole) 39A: Nozzle hole (first nozzle hole) 39B: Nozzle hole (second nozzle hole) 41: Actuator plate (channel definition section, actuator section) 42: Support plate 45: Opposing section (actuator section) 46: Partition section 46a: +X side partition section (partition section) 46b: -X side partition section (partition section) 47: Individual channel 47a: First individual channel 47b: Second individual channel 49: Standard groove 50: Pressure chamber 50A: Pressure chamber (first pressure chamber) 50B: Pressure chamber (second pressure chamber) 81a: Common electrode (drive electrode) 81Aa, 81Ba: First common electrode (common electrode, driving electrode) 81Ab, 81Bb: Second common electrode (common electrode, driving electrode) 149A: First specified groove (specified groove) 149B: Second specified groove (specified groove)

Claims

1. A head tip comprising: a flow path defining section having a plurality of partitions spaced apart in a first direction, and forming a plurality of individual flow paths between adjacent partitions, through which liquid can flow in a second direction intersecting the first direction; and an actuator section superimposed on the flow path defining section so as to face each of the plurality of individual flow paths in a third direction intersecting the second direction when viewed from the first direction, and which is deformable to expand or contract the inside of the individual flow paths, wherein a defined groove is formed in a part of the partition in the second direction, connecting the inside of one individual flow path to the outside of one individual flow path, and an injection hole is formed in one of the individual flow paths at a position offset in the second direction from the defined groove, and an injection hole plate is provided facing the actuator section.

2. The head tip according to claim 1, wherein the specified groove extends linearly in the first direction and connects adjacent individual flow paths.

3. The actuator portion is provided with a drive electrode that generates an electric field in the actuator portion, and of the actuator portion, only electrodes of the same polarity are formed on the first surface facing the individual flow path in the third direction.

4. The head tip according to claim 3, wherein the drive electrode formed on the first surface is a common electrode that serves as a reference potential.

5. A head tip according to any one of claims 2 to 4, wherein a common channel is provided on one side in the second direction with respect to the individual channels, extending in the first direction and communicating with the plurality of individual channels, and the defined groove extends in the first direction and communicates with the common channel at one end in the second direction.

6. A head tip according to any one of claims 2 to 5, wherein a common channel is provided on one side in the second direction with respect to the individual channels, extending in the first direction and communicating with the plurality of individual channels, and the defined groove is provided in the partition portion at a position separated in the second direction with respect to the common channel.

7. The head tip according to any one of claims 2 to 6, wherein the specified groove includes a first specified groove provided on the first side in the second direction with respect to the injection hole, and a second specified groove provided on the second side in the second direction with respect to the injection hole.

8. The head tip according to claim 7, wherein the distance between the injection hole and the first defined groove in the second direction is equal to the distance between the injection hole and the second defined groove.

9. The head tip according to any one of claims 2 to 8, wherein, among the individual flow paths, adjacent individual flow paths are designated as a first individual flow path and a second individual flow path, and among the injection holes, the injection hole communicating with the first individual flow path is designated as a first injection hole, and the injection hole communicating with the second individual flow path is designated as a second injection hole, wherein the portion of the first individual flow path located on the first side in the second direction with respect to the specified groove constitutes a first pressure chamber communicating with the first injection hole, and the portion of the second individual flow path located on the second side in the second direction with respect to the specified groove constitutes a second pressure chamber communicating with the second injection hole.

10. The head tip according to claim 9, wherein the dimension in the first direction of the first pressure chamber is greater than the dimension in the first direction of the portion of the first individual flow path located on the second side in the second direction with respect to the specified groove, and the dimension in the first direction of the second pressure chamber is greater than the dimension in the first direction of the portion of the second individual flow path located on the first side in the second direction with respect to the specified groove.

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

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

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