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

Abstract

To provide a head chip, a liquid jet head, a liquid jet recording device, and a head chip manufacturing method, capable of suppressing variation in discharge speed while improving manufacturing efficiency.SOLUTION: A head chip according to an aspect of the present disclosure includes an actuator plate in which a channel having a first opening and a second opening is formed. In the actuator plate, formed are: a drive electrode formed on an inner surface of the channel; and drive wiring formed on the first surface of the actuator plate and connected to the drive electrode through an opening edge of the first opening. The drive electrode includes: a first electrode extending in the thickness direction from an opening edge of the first opening and having a dimension in the first direction smaller than that of the second opening; and a second electrode extending from an opening edge of the first opening in a thickness direction in a state of being partly overlapped with the first electrode, the second electrode having a dimension in the thickness direction smaller than that of the first electrode and a dimension in a first direction larger than that of the first electrode.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] The inkjet head ejects ink onto a recording medium through a head chip. The head chip includes an actuator plate in which ejection channels and non-ejection channels are formed, and a nozzle plate joined to the actuator plate. The ejection channels and non-ejection channels each penetrate the actuator plate in the thickness direction, and are arranged alternately with the drive wall between them. A common electrode is formed on the inner surface of the ejection channel. An individual electrode is formed on the inner surface of the non-ejection channel. In the head chip, the volume of the ejection channel is changed by applying a voltage between the common electrode and the individual electrodes to cause the thickness sliding deformation of the driving wall, which causes the ink in the ejection channel to be ejected through the nozzle hole formed in the nozzle plate.

[0003] For example, the following Patent Document 1 discloses a method for forming a common electrode and individual electrodes by performing oblique deposition sequentially through an opening on the front side and an opening on the back side of an actuator plate (so-called double-sided deposition). With this configuration, it is possible to form a film of electrode material over the entire inner surface of each channel in the thickness direction of the actuator plate. As a result, it is believed that it is possible to suppress the variation in electrode area between each channel, and thus the variation in ejection speed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-75449 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional double-sided deposition configuration, it is necessary to perform oblique deposition from the front side, grind the rear side of the actuator plate to open the opening on the rear side of the actuator plate, and then perform oblique deposition again from the rear side, which leaves room for improvement in terms of improving manufacturing efficiency. In addition, in the process of grinding the back surface of the actuator plate, the electrode material adhering to the inner surface of the channel may remain as burrs on the edge of the opening on the back surface of the actuator plate. The remaining burrs may cause poor bonding when bonding the nozzle plate to the back surface of the actuator plate. Furthermore, when oblique deposition is performed through the opening on the back side of the actuator plate, the electrode material also adheres to the back side of the actuator plate. The electrode material adhered to the back side of the actuator plate may be peeled off due to rubbing or the like of the back side of the actuator plate.

[0006] The present disclosure provides a head chip, a liquid jet head, a liquid jet recording apparatus, and a method for manufacturing the head chip, which are capable of suppressing variations in ejection speed while improving manufacturing efficiency. [Means for solving the problem]

[0007] In order to solve the above problems, the present disclosure employs the following aspects. (1) A head chip according to one embodiment of the present disclosure comprises an actuator plate having a first opening on a first surface facing a first side in a thickness direction, and a second opening on a second surface facing a second side opposite to the first side in the thickness direction, the second opening having a length in a first direction intersecting the thickness direction shorter than that of the first opening, and a channel formed therein extending in a first direction intersecting the thickness direction, the actuator plate having a drive electrode formed on an inner surface of the channel, and a drive wiring formed on the first surface of the actuator plate and connected to the drive electrode through an edge of the first opening, the drive electrode comprising: a first electrode extending from the edge of the first opening in the thickness direction and having a dimension in the first direction smaller than that of the second opening, and a second electrode extending in the thickness direction from the edge of the first opening with a portion overlapping with the first electrode, the dimension in the thickness direction smaller than that of the first electrode and the dimension in the first direction larger than that of the first electrode.

[0008] According to this aspect, by making the dimension in the first direction of the first electrode, which has a large dimension in the thickness direction, smaller than that of the second electrode, it is possible to prevent an electrode from being formed on the opening edge of the second opening (the boundary between the channel inner surface and the second surface) facing the first direction. Therefore, when the second opening is opened by grinding the second surface of the actuator plate or the like after forming the driving electrode through the first opening in the channel recess, it is possible to prevent the electrode near the opening edge of the second opening from being removed and remaining as burrs. In addition, by forming the second electrode, which is larger in the first direction than the first electrode and smaller in the thickness direction, so as to overlap a part of the first electrode, it is easy to ensure the area of ​​the entire driving electrode. Therefore, when a voltage is applied by the driving electrode, it is easy to ensure the electrostatic capacitance generated in the wall (driving wall) that divides the channel, and it is easy to ensure the output when ejecting liquid.

[0009] (2) In the head chip according to the above aspect (1), it is preferable that the first electrode is formed over the entire length of the channel in the thickness direction. According to this aspect, the dimensional variation of the first electrode for each channel can be suppressed, and therefore the area variation of the drive electrode for each channel can be suppressed. Therefore, when a voltage is applied by the drive electrode, the capacitance generated in the drive wall corresponding to each channel can be easily made uniform. As a result, the variation in the ejection performance (speed) can be suppressed.

[0010] (3) In the head chip according to the above aspect (1) or (2), when the dimension of the first electrode in the thickness direction is D1 and the dimension of the second electrode in the thickness direction is D2, it is preferable that the following formula is satisfied. (D1-D2)>D2 According to this aspect, the variation in the thickness direction of the second electrode between the channels can be suppressed, and the variation in the area of ​​the drive electrode between the channels can be suppressed. Therefore, when a voltage is applied by the drive electrode, the capacitance generated in the drive wall corresponding to each channel can be easily made uniform. As a result, the variation in the ejection performance (speed) can be suppressed.

[0011] (4) In the head chip according to the above aspect (1) or (2), when the dimension of the first electrode in the thickness direction is D1 and the dimension of the second electrode in the thickness direction is D2, it is preferable that the following formula is satisfied. (D1-D2) <D2 According to this aspect, it is easy to ensure the area of ​​the entire driving electrodes between the channels, which makes it easy to ensure the capacitance generated in the walls (driving walls) that separate the channels when a voltage is applied by the driving electrodes, and therefore easy to ensure the output during liquid ejection.

[0012] (5) A liquid jet head according to an aspect of the present disclosure preferably includes the head chip according to any one of the above aspects (1) to (6). According to this aspect, since the head chip according to the above aspect is included, it is possible to provide a liquid jet head that has high performance and excellent reliability.

[0013] (6) A liquid jet recording apparatus according to an aspect of the present disclosure preferably includes the liquid jet head according to aspect (6) above. According to this aspect, since the liquid jet head according to the above aspect is provided, it is possible to provide a liquid jet recording apparatus that has high performance and excellent reliability.

[0014] (7) A method of manufacturing a head chip according to one aspect of the present disclosure includes the steps of: forming, on an actuator plate having a recess that is open on a first surface facing a first side in a thickness direction and has a dimension in a first direction intersecting the thickness direction that decreases toward a second side opposite the first side in the thickness direction, a first electrode forming step of forming, on an inner surface of the recess, a first electrode extending in the thickness direction from an opening edge of the first opening through the first opening; and forming, on the actuator plate, a second electrode extending in the thickness direction from the opening edge of the first opening through the first opening. and a grinding process of grinding a second surface of the actuator plate facing a second side in the thickness direction, wherein in the grinding process, the recess is opened onto the second surface to form a channel that penetrates the actuator plate in the thickness direction and has the first opening and a second opening whose length in the first direction is shorter than that of the first opening, wherein the first electrode has a dimension in the first direction smaller than that of the second opening, and the second electrode, with a portion overlapping with the first electrode, has a dimension in the thickness direction smaller than that of the first electrode and a dimension in the first direction larger than that of the first electrode.

[0015] (8) In the method for manufacturing a head chip relating to the above aspect (7), the first electrode formation process is performed by an oblique deposition method in which a conductor is deposited from an oblique direction relative to the normal direction of the first surface when viewed from the first direction, and in the first electrode formation process, it is preferable that deposition is performed on the inner surface of the recess so that at least a portion of the first electrode is larger than the dimension of the channel in the thickness direction. According to this aspect, after the grinding process, at least a part of the first electrodes is formed on the inner surface of the channel over the entire area in the thickness direction. This makes it possible to suppress the dimensional variation of the first electrodes for each channel. Therefore, when a voltage is applied by the drive electrode, it becomes easier to uniformize the capacitance generated in the drive wall corresponding to each channel. As a result, it is possible to suppress the variation in the ejection performance (speed).

[0016] (9) In the method for manufacturing a head chip according to the above aspect (7) or (8), the second electrode forming process is preferably performed by an oblique deposition method in which a conductor is deposited from an oblique direction relative to a normal direction of the first surface when viewed from the first direction, and in the second electrode forming process, deposition is preferably performed on the inner surface of the recess so that the entire second electrode is smaller than the dimension of the channel in the thickness direction. According to this aspect, it is possible to prevent the entire second electrode from reaching the edge of the second opening after the grinding process, which in turn prevents the electrode near the edge of the opening from remaining without being removed (the occurrence of burrs) after the grinding process.

[0017] (10) In the method for manufacturing a head chip according to any one of the above aspects (7) to (9), it is preferable that the first electrode forming step is performed prior to the second electrode forming step. According to this aspect, if the first electrode reaches the portion of the second opening edge of each channel facing the first direction, it can be determined that the product is defective at that point in time. This makes it unnecessary to carry out post-processing for products determined to be defective, thereby improving manufacturing efficiency.

[0018] (11) In the method for manufacturing a head chip according to any one of the above aspects (7) to (9), it is preferable that the second electrode forming step is performed prior to the first electrode forming step, and the second electrode is formed on the first surface of the actuator plate using a second electrode mask having a mask opening corresponding to the first opening, and that the first electrode forming step is performed while a first electrode mask having a mask opening smaller in dimension in the first direction than the first opening is set on the second electrode mask. According to this embodiment, since the mask for the first electrode, which is set separately on the actuator plate, involves the risk of foreign matter adhering to the actuator plate, the second electrode can be formed with high precision by performing the second electrode formation process before setting the mask for the first electrode. Effect of the Invention

[0019] According to one aspect of the present disclosure, it is possible to suppress variation in ejection speed while improving manufacturing efficiency. [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic configuration diagram of an inkjet printer according to a first embodiment. [Diagram 2] FIG. 2 is a schematic configuration diagram of an inkjet head and an ink circulation mechanism according to the first embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of the discharge unit according to the first embodiment. [Figure 4] FIG. 2 is an exploded perspective view of the head chip according to the first embodiment. [Diagram 5] FIG. 2 is a plan view of the actuator plate according to the first embodiment. [Figure 6] 6 is a cross-sectional view of the head chip taken along line VI-VI in FIG. 5. [Figure 7] 7 is a cross-sectional view of the head chip taken along line VII-VII in FIG. 5. [Figure 8] 8 is an end view corresponding to line VIII-VIII in FIG. 5. [Figure 9] 5 is a flowchart for explaining a manufacturing method of the discharge unit according to the first embodiment. [Figure 10] FIG. 9 is a process diagram for explaining a machining process of the actuator according to the first embodiment, and is an end view corresponding to FIG. 8. [Figure 11] FIG. 9 is a process diagram for explaining a machining process of the actuator according to the first embodiment, and is an end view corresponding to FIG. 8. [Figure 12] 7 is a process drawing for explaining a process for machining the actuator according to the first embodiment, and is a cross-sectional view corresponding to FIG. 6. FIG. [Figure 13] 8 is a process drawing for explaining a process for machining the actuator according to the first embodiment, and is a cross-sectional view corresponding to FIG. 7. [Figure 14] 7 is a process drawing for explaining a process for machining the actuator according to the first embodiment, and is a cross-sectional view corresponding to FIG. 6. FIG. [Figure 15] 8 is a process drawing for explaining a process for machining the actuator according to the first embodiment, and is a cross-sectional view corresponding to FIG. 7. [Figure 16] FIG. 9 is a process diagram for explaining a machining process of the actuator according to the first embodiment, and is an end view corresponding to FIG. 8. [Figure 17] FIG. 13 is an explanatory diagram for explaining deposition depth. [Figure 18] FIG. 8 is a process diagram for explaining an intermediate plate machining process according to the first embodiment, and is a cross-sectional view corresponding to FIG. 7. [Figure 19] FIG. 8 is a process diagram for explaining an intermediate plate machining process according to the first embodiment, and is a cross-sectional view corresponding to FIG. 7. [Figure 20] FIG. 8 is a process diagram for explaining an intermediate plate machining process according to the first embodiment, and is a cross-sectional view corresponding to FIG. 7. [Figure 21] FIG. 8 is a process diagram for explaining a surface plate processing step according to the first embodiment, and is a cross-sectional view corresponding to FIG. 7. [Figure 22]FIG. 8 is a process diagram for explaining a surface plate processing step according to the first embodiment, and is a cross-sectional view corresponding to FIG. 7. [Figure 23] FIG. 8 is a process diagram for explaining a surface plate processing step according to the first embodiment, and is a cross-sectional view corresponding to FIG. 7. [Figure 24] FIG. 9 is a process diagram for explaining the grinding step according to the first embodiment, and is an end view corresponding to FIG. 8. [Diagram 25] FIG. 8 is a process diagram for explaining a cutting step, and is a cross-sectional view corresponding to FIG. 7. [Figure 26] 7 is a cross-sectional view of a head chip according to a second embodiment, corresponding to FIG. 6. [Figure 27] 8 is a cross-sectional view of a head chip according to a second embodiment, corresponding to FIG. 7. [Figure 28] 9 is an end view of a head chip according to a third embodiment, the end view corresponding to FIG. 8. FIG. [Figure 29] FIG. 13 is an exploded perspective view of a head chip according to a fourth embodiment. [Diagram 30] 29 is a cross-sectional view corresponding to line XXVIII-XXVIII in FIG. 28. [Diagram 31] 29 is a cross-sectional view corresponding to the line XXX-XXX in FIG. 28. [Diagram 32] FIG. 13 is a plan view of an actuator plate according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. In the embodiments and modified examples described below, the same reference numerals may be used to designate corresponding configurations, and the description may be omitted. In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," not only strictly indicate such arrangements, but also indicate a state in which the components are relatively displaced with a tolerance or an angle or distance to the extent that the same function is obtained. In the following embodiment, an inkjet printer (hereinafter, simply referred to as a printer) that uses ink (liquid) to record on a recording medium will be taken as an example for description. In the drawings used in the following description, the scale of each component has been appropriately changed so that each component can be recognized.

[0022] (First embodiment) [Printer 1] FIG. 1 is a schematic diagram of a printer 1. A printer (liquid jet recording apparatus) 1 shown in FIG. 1 includes a pair of transport mechanisms 2 and 3, an ink tank 4, an inkjet head (liquid jet head) 5, an ink circulation mechanism 6, and a scanning mechanism .

[0023] In the following explanation, an X, Y, Z Cartesian coordinate system is used as necessary. In this case, the X direction coincides with the transport direction (sub-scanning direction) of the recording medium P (e.g., paper, etc.). The Y direction coincides with the scanning direction (main scanning direction) of the scanning mechanism 7. The Z direction indicates the height direction (gravity direction) perpendicular to the X and Y directions. In the following explanation, the X, Y, and Z directions will be explained with the arrows on the figures as the plus (+) side and the opposite side to the arrows as the minus (-) side. In this specification, the +Z side corresponds to the upward direction of gravity, and the -Z side corresponds to the downward direction of gravity.

[0024] The transport mechanisms 2 and 3 transport the recording medium P to the +X side. The transport mechanisms 2 and 3 each include a pair of rollers 11 and 12 extending in the Y direction, for example. The ink tanks 4 each contain ink of four colors, for example, yellow, magenta, cyan, and black. Each inkjet head 5 is configured to be capable of ejecting ink of one of the four colors, yellow, magenta, cyan, or black, according to the ink tank 4 connected thereto.

[0025] FIG. 2 is a schematic diagram of the ink-jet head 5 and the ink circulation mechanism 6. As shown in FIG. 1 and 2, the ink circulation mechanism 6 circulates ink between the ink tank 4 and the inkjet head 5. Specifically, the ink circulation mechanism 6 includes a circulation flow path 23 having an ink supply pipe 21 and an ink discharge pipe 22, a pressure pump 24 connected to the ink supply pipe 21, and a suction pump 25 connected to the ink discharge pipe 22.

[0026] The pressure pump 24 pressurizes the inside of the ink supply pipe 21, and sends ink to the inkjet head 5 through the ink supply pipe 21. As a result, the ink supply pipe 21 side relative to the inkjet head 5 is under positive pressure. The suction pump 25 reduces the pressure inside the ink discharge tube 22 and sucks ink from the inkjet head 5 through the ink discharge tube 22. This creates a negative pressure on the ink discharge tube 22 side relative to the inkjet head 5. By driving the pressure pump 24 and the suction pump 25, the ink can be circulated between the inkjet head 5 and the ink tank 4 through the circulation flow path 23.

[0027] 1, the scanning mechanism 7 causes the inkjet head 5 to scan back and forth in the Y direction. The scanning mechanism 7 includes a guide rail 28 extending in the Y direction, and a carriage 29 movably supported by the guide rail 28.

[0028] <Inkjet head 5> The inkjet head 5 is mounted on a carriage 29. In the illustrated example, a plurality of inkjet heads 5 are mounted side by side in the Y direction on one carriage 29. The inkjet head 5 includes a discharge unit 30 (see FIG. 2), an ink supply unit (not shown) that connects the ink circulation mechanism 6 and the discharge unit 30, and a control unit (not shown) that applies a drive voltage to the discharge unit 30.

[0029] (First embodiment) [Discharge unit 30] FIG. 3 is an exploded perspective view of the discharge unit 30. As shown in FIG. 3 is a so-called circulation type side shoot type discharge unit 30 that circulates ink between the ink tank 4 and discharges ink from the center of an ejection channel 51 (described later) in the extension direction (Y direction). The discharge unit 30 includes a flow path plate 31, a head chip 32, a nozzle plate 33, a flow path cover 34, and a flexible printed circuit board 35 (see FIG. 6).

[0030] <Flow path plate 31> The flow channel plate 31 is formed in a rectangular frame shape with the thickness direction being the Z direction and the longitudinal direction being the X direction. The flow channel plate 31 defines a chip storage section 31a, an inlet common flow channel 31b, and an outlet common flow channel 31c. The chip storage 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 plate 31 in the Z direction.

[0031] The chip receiving portion 31a is formed in the center in the Y direction of the flow path plate 31. The chip receiving portion 31a is formed in an elongated hole shape with the X direction as the longitudinal direction in a plan view. The inlet common flow channel 31b is formed in a portion of the flow channel plate 31 that is located on the +Y side of the chip storage unit 31a. The inlet common flow channel 31b is formed in an elongated hole shape with the X direction as the longitudinal direction, similar to the chip storage unit 31a. The +X side end of the inlet common flow channel 31b protrudes in the X direction with respect to the chip storage unit 31a. The outlet common flow channel 31c is formed in a portion of the flow channel plate 31 that is located on the -Y side with respect to the chip storage unit 31a. The outlet common flow channel 31c is formed in an elongated hole shape with the X direction as the longitudinal direction, similar to the inlet common flow channel 31b. The -X side end of the outlet common flow channel 31c protrudes in the X direction with respect to the chip storage unit 31a.

[0032] <Head chip 32> As shown in FIG. 3, head chip 32 is formed in a block shape with the thickness direction being the Z direction and the longitudinal direction being the X direction. Head chip 32 is fitted into chip accommodating section 31a. Specifically, head chip 32 is formed so that the thickness in the Z direction is equivalent to that of flow path plate 31 and the planar shape is equivalent to that of chip accommodating section 31a. In this case, head chip 32 has a +X side end face fixed by adhesion or the like to a surface facing the -X side among the inner surfaces of chip accommodating section 31a, and a -X side end face fixed by adhesion or the like to a surface facing the -X side among the inner surfaces of chip accommodating section 31a. Therefore, in flow path plate 31, inlet common flow path 31b and outlet common flow path 31c are blocked by head chip 32.

[0033] Fig. 4 is an exploded perspective view of head chip 32. Fig. 5 is a plan view of actuator plate 41. Fig. 6 is a cross-sectional view of head chip 32 corresponding to line VI-VI in Fig. 5. Fig. 6 is a cross-sectional view of head chip 32 corresponding to line VII-VII in Fig. 5. As shown in Figs. 4 to 7, the head chip 32 includes an actuator plate 41, an intermediate plate 42, and a surface plate 43. The head chip 32 has the actuator plate 41, the intermediate plate 42, and the surface plate 43 stacked in this order in the Z direction. In the following description, in the Z direction, the direction from the actuator plate 41 toward the surface plate 43 (+Z side) may be referred to as the upper side, and the direction from the surface plate 43 toward the actuator plate 41 (-Z side) may be referred to as the lower side. In the first embodiment, the lower surface of the head chip 32 is disposed flush with the lower surface of the flow path plate 31. On the other hand, the upper surface of the head chip 32 is disposed flush with the upper surface of the flow path plate 31.

[0034] The actuator plate 41 is made of a piezoelectric material such as PZT (lead zirconate titanate). The actuator plate 41 is a so-called chevron substrate formed by laminating two piezoelectric plates whose polarization directions are different in the Z direction. However, the actuator plate 41 may be a so-called monopole substrate whose polarization direction is one direction over the entire Z direction.

[0035] A channel row 46 is formed in the actuator plate 41. The channel row 46 has ejection channels 51 that are filled with ink and non-ejection channels 52 that are not filled with ink. The channels 51, 52 are alternately arranged at intervals in the X direction in the actuator plate 41. In the first embodiment, a configuration in which the channel extension direction coincides with the Y direction will be described, but the channel extension direction may intersect with the Y direction.

[0036] The discharge channels 51 penetrate the actuator plate 41 in the Z direction and extend linearly in the Y direction over the entire length of the actuator plate 41. The +Y side opening of each discharge channel 51 communicates with the inlet common flow path 31b. Meanwhile, the -Y side opening of each discharge channel 51 communicates with the outlet common flow path 31c. That is, the inlet common flow path 31b and the outlet common flow path 31c communicate with each discharge channel 51.

[0037] 4 and 7, the non-ejection channels 52 extend linearly in the Y direction in the portions of the actuator plate 41 that are located between adjacent ejection channels 51. The portions of the actuator plate 41 that are located between adjacent ejection channels 51 and non-ejection channels 52 each constitute a driving wall 53. Therefore, the channels 51, 52 are surrounded on both sides in the X direction by a pair of driving walls 53.

[0038] Both ends of the non-ejection channel 52 in the Y direction terminate within the actuator plate 41. Therefore, the non-ejection channel 52 does not communicate with the inlet common flow path 31b and the outlet common flow path 31c. The non-ejection channel 52 is formed in a circular arc shape that protrudes downward when viewed from the X direction. That is, the dimension of the non-ejection channel 52 in the Y direction gradually decreases from the top to the bottom. Specifically, the non-ejection channel 52 has a through portion 52a located in the center in the Y direction and cut-up portions 52b that are continuous with both sides of the through portion 52a in the Y direction.

[0039] The through portion 52a passes through the actuator plate 41 in the Z direction. The cut-up portion 52b opens on the upper surface of the actuator plate 41, and the dimension in the Z direction gradually decreases as it moves away from the through portion 52a in the Y direction. That is, the upper end opening of the non-ejection channel 52 is formed by the through portion 52a and the cut-up portion 52b. On the other hand, the lower end opening of the non-ejection channel 52 is formed by the through portion 52a. The bottom surface of the cut-up portion 52b is formed in an arc shape with a uniform radius of curvature. A dividing groove 52c is formed in the center of the bottom surface of each cut-up portion 52b in the X direction. The dividing groove 52c is recessed over the entire length in the Y direction with respect to the bottom surface of each cut-up portion 52b. The dividing groove 52c extends concentrically with the cut-up portion 52b in a side view.

[0040] In the following description, the portion of the actuator plate 41 located between adjacent ejection channels 51 and on the -Y side of the non-ejection channels 52 is referred to as a first tail portion 41a. The portion of the actuator plate 41 located between adjacent ejection channels 51 and on the +Y side of the non-ejection channels 52 is referred to as a second tail portion 41b.

[0041] <Intermediate plate 42> 4, 6, and 7, the intermediate plate 42 functions as a connection substrate between various drive wirings formed on the actuator plate 41 and various terminal wirings formed on the surface plate 43. The intermediate plate 42 is a plate material made of a piezoelectric material such as PZT, a resin material such as polyimide, or other non-conductive material. In the illustrated example, the dimension of the intermediate plate 42 in the Z direction is smaller than that of the actuator plate 41.

[0042] The intermediate plate 42 has the same outer shape as the actuator plate 41 in a plan view, and is superimposed on the entire upper surface of the actuator plate 41. The intermediate plate 42 is bonded to the upper surface of the actuator plate 41 with an adhesive or the like.

[0043] As shown in Figs. 4 and 7, the intermediate plate 42 is formed with an intermediate common hole 42a, a first intermediate individual hole 42b, and a second intermediate individual hole 42c. Each of the intermediate holes 42a to 42c is circular in plan view and tapered so that the inner diameter gradually decreases from top to bottom. However, the inner diameter of each of the intermediate holes 42a to 42c may be uniform over the entire Z direction. In addition, the plan view shape of each of the intermediate holes 42a to 42c can be appropriately changed to an elliptical shape, a polygonal shape, or the like. The intermediate common hole 42a, the first intermediate individual hole 42b, and the second intermediate individual hole 42c may be the same shape or different shapes.

[0044] The intermediate common hole 42a penetrates in the Z direction through a portion of the intermediate plate 42 that overlaps with the first tail portion 41a in a plan view. That is, the intermediate common hole 42a is provided between the discharge channels 51 adjacent to each other.

[0045] The first intermediate individual hole 42b and the second intermediate individual hole 42c are formed separately on both sides in the Y direction with respect to the non-ejection channel 52. Specifically, the first intermediate individual hole 42b penetrates in the Z direction a portion of the intermediate plate 42 that overlaps with the first tail portion 41a in a plan view and is located on the +Y side of the intermediate common hole 42a. The second intermediate individual hole 42c penetrates in the Z direction a portion of the intermediate plate 42 that overlaps with the second tail portion 41b in a plan view. That is, the first intermediate individual hole 42b and the second intermediate individual hole 42c are provided for each non-ejection channel 52.

[0046] <Surface plate 43> The surface plate 43 is used for connecting the head chip 32 and the flexible printed circuit board (external wiring) 35. The surface plate 43 is a plate material made of a piezoelectric material such as PZT, a resin material such as polyimide, or other non-conductive material. In this case, the intermediate plate 42 and the surface plate 43 may be made of the same material or different materials. In the first embodiment, it is preferable that the surface plate 43 has a higher rigidity (a larger Young's modulus) than the intermediate plate 42. In the illustrated example, the dimension of the surface plate 43 in the Z direction is larger than that of the actuator plate 41. That is, the dimension of each plate constituting the head chip 32 in the Z direction is the largest for the surface plate 43 and the smallest for the intermediate plate 42.

[0047] The surface plate 43 has the same outer shape as the intermediate plate 42 in a plan view, and is superimposed on the entire upper surface of the intermediate plate 42. The surface plate 43 is bonded to the upper surface of the intermediate plate 42 by an adhesive or the like.

[0048] The surface plate 43 is formed with a surface common hole 43a and surface individual holes 43b. Each of the surface holes 43a, 43b has an elliptical shape with the Y direction as the major axis in a plan view, and is formed in a tapered shape in which the inner diameter gradually decreases from the top to the bottom. However, the inner diameter of each of the surface holes 43a, 43b may be uniform over the entire Z direction. The plan view shape of each of the surface holes 43a, 43b can also be appropriately changed to a circular shape, a polygonal shape, or the like. The surface common hole 43a and the surface individual holes 43b may be the same shape or different shapes.

[0049] As shown in FIG. 4 and FIG. 6, the surface common hole 43a penetrates in the Z direction through a portion of the surface plate 43 that overlaps with the -Y side end of the discharge channel 51 in a plan view (a portion located between adjacent first tail portions 41a). That is, the surface common hole 43a is provided corresponding to each discharge channel 51. In a plan view, the surface common hole 43a is disposed shifted in the X direction relative to the intermediate common hole 42a. Meanwhile, in a side view, the lower end opening of the surface common hole 43a is located on the +Y side relative to the intermediate common hole 42a. However, the lower end opening of the surface common hole 43a may be provided on the -Y side relative to the intermediate common hole 42a, or may be provided at the same position in the Y direction.

[0050] The surface individual hole 43b penetrates in the Z direction through a portion of the surface plate 43 that overlaps with the +Y side end of the non-ejection channel 52 in a plan view (a portion located on each second tail portion 41b). That is, the surface individual hole 43b is provided corresponding to each non-ejection channel 52. The surface individual hole 43b and the intermediate individual holes 42b, 42c are aligned in a straight line in the Y direction. Specifically, the lower end opening of the surface individual hole 43b is located on the +Y side with respect to the second intermediate individual hole 42c. However, the lower end opening of the surface individual hole 43b may be provided on the -Y side with respect to the second intermediate individual hole 42c, or may be formed at a position that overlaps with the first tail portion 41a in a plan view.

[0051] The surface common hole 43a and the surface individual holes 43b are arranged at both ends in the Y direction of the surface plate 43, shifted by half a pitch with respect to the arrangement pitch of the ejection channels 51 (or non-ejection channels 52). In the first embodiment, the surface common hole 43a and the surface individual holes 43b are shifted from each other in the X direction when viewed from the Y direction. However, a portion of the surface common hole 43a and the surface individual holes 43b may overlap each other when viewed from the Y direction.

[0052] Next, various wirings formed on the head chip 32 will be described. As shown in FIGS. 4 to 7, the actuator plate 41 is provided with common wiring 61 and individual wiring 62 as drive wiring.

[0053] The common wiring 61 includes a common electrode (drive electrode) 65 and a common output wiring (drive wiring) 66. The common electrodes 65 are formed on the inner surfaces of the ejection channel 51 that face each other in the X direction. Specifically, the common electrodes 65 include a narrow common electrode 65a and a wide common electrode 65b. In the following description, the common electrode 65 formed on the inner surface facing the +X side will be described as an example.

[0054] FIG. 8 is an end view corresponding to line VIII-VIII in FIG. As shown in FIG. 4, FIG. 6, and FIG. 8, the narrow common electrode 65a is an electrode corresponding to the lower layer of the common electrode 65. The narrow common electrode 65a extends in a strip shape in the Z direction, for example, with a uniform dimension in the Y direction, on a portion including the center in the Y direction of the inner surface of the ejection channel 51. Specifically, the dimension in the Y direction of the narrow common electrode 65a is smaller than the dimension in the Y direction of the ejection channel 51. In the illustrated example, the dimension in the Y direction of the wide common electrode 65a is smaller than the dimension in the lower end opening of the non-ejection channel 52 (see FIG. 7). Note that the dimension in the Y direction of the narrow common electrode 65a may change depending on the position in the Z direction, as long as it is smaller than the dimension in the Y direction at the lower end edge of the ejection channel 51 at the lower end opening.

[0055] The narrow common electrode 65a is formed over the entire area in the Z direction on the inner surface of the ejection channel 51. Specifically, the upper edge of the narrow common electrode 65a is located at the upper opening edge of the ejection channel 51. The lower edge of the narrow common electrode 65a is located at the lower opening edge of the ejection channel 51. However, it is sufficient that at least the upper edge of the narrow common electrode 65a is located at the upper opening edge of the ejection channel 51.

[0056] The wide common electrode 65b is an electrode corresponding to the upper layer of the common electrode 65. A part of the wide common electrode 65b is overlapped with the narrow common electrode 65a. The wide common electrode 65b extends in a strip shape in the Z direction, for example, with a uniform dimension in the Y direction, on a part including the center part in the Y direction of the inner surface of the ejection channel 51. The wide common electrode 65b has a larger dimension in the Y direction than the narrow common electrode 65a. Therefore, the wide common electrode 65b protrudes on both sides in the Y direction with respect to the narrow common electrode 65a. In the illustrated example, the wide common electrode 65b is formed over the entire area of ​​the ejection channel 51 in the Y direction.

[0057] The wide common electrode 65b is formed on the upper part of the inner side surface of the discharge channel 51. Specifically, the upper end edge of the wide common electrode 65b is located at the upper opening edge of the discharge channel 51. The lower end edge of the wide common electrode 65b is located above the lower end edge of the narrow common electrode 65a. Therefore, the narrow common electrode 65a and the wide common electrode 65b overlap each other at least at the upper part and the center part in the Y direction of the inner side surface of the discharge channel 51. In the illustrated example, the centers of the narrow common electrode 65a and the wide common electrode 65b in the Y direction are aligned. However, the centers of the narrow common electrode 65a and the wide common electrode 65b in the Y direction may be shifted from each other as long as the upper end edges of each other are located at the upper opening edge of the discharge channel 51 and overlap each other in a part in the Y direction.

[0058] In the first embodiment, when the dimension in the Z direction of the narrow common electrode 65a is D1a and the dimension in the Z direction of the wide common electrode 65b is D2a, it is preferable that the following formula (1) is satisfied. (D1a-D2a)>D2a···(1)

[0059] 4, the common output wiring 66 extends in a strip shape in the X direction on the upper surface of the first tail portion 41a. The common output wiring 66 connects the common electrodes 65 that face each other in the X direction with the non-ejection channel 52 therebetween at the upper end opening edges of the ejection channels 51 that face each other in the X direction with the non-ejection channel 52 therebetween. In the illustrated example, the common output wiring 66 connects the portions of the wide common electrodes 65b that face each other in the X direction with the non-ejection channel 52 therebetween that protrude toward the +Y side with respect to the narrow common electrode 65a.

[0060] As shown in FIGS. 4, 7 and 8, the individual wiring 62 includes an individual electrode (drive electrode) 68 and an individual extraction wiring (drive wiring) 69. The individual electrodes 68 include a first individual electrode 68a formed on at least the inner surface facing the -X side of the inner surface of the non-ejection channel 52, and a second individual electrode 68b formed on at least the inner surface facing the +X side. Each of the individual electrodes 68a, 68b includes a narrow individual electrode 77 and a wide common electrode 78. Details of each of the individual electrodes 68a, 68b will be described using the second individual electrode 68b as an example.

[0061] As shown in FIG. 7 and FIG. 8, the narrow individual electrode 77 is an electrode corresponding to the lower layer of the second individual electrode 68b. The narrow individual electrode 77 extends in the Z direction in a strip shape, for example, with a uniform dimension in the Y direction, on a portion including the center portion in the Y direction of the inner surface facing the +X side of the non-ejection channel 52. Specifically, the dimension of the narrow individual electrode 77 in the Y direction is smaller than the dimension of the lower end opening of the non-ejection channel 52 in the Y direction. Therefore, both ends of the narrow individual electrode 77 in the Y direction are separated from the portion of the lower end opening edge of the non-ejection channel 52 facing the Y direction and the bottom surface of the non-ejection channel 52 (the cut-up portion 52b). Note that the dimension of the narrow individual electrode 77 in the Y direction may change depending on the position in the Z direction, as long as it is smaller than the dimension of the lower end opening of the non-ejection channel 52 in the Y direction at the lower end edge.

[0062] The narrow individual electrodes 77 are formed over the entire area in the Z direction on the inner surface facing the +X side of the non-ejection channels 52. Specifically, the upper edge of the narrow individual electrodes 77 is located at the upper opening edge of the non-ejection channels 52. The lower edge of the narrow individual electrodes 77 is located at the lower opening edge of the non-ejection channels 52. However, it is sufficient that at least the upper edge of the narrow individual electrodes 77 is located at the upper opening edge of the non-ejection channels 52.

[0063] The wide individual electrode 78 is an electrode corresponding to the upper layer of the second individual electrode 68b. A part of the wide individual electrode 78 overlaps with the narrow individual electrode 77. The wide individual electrode 78 is formed on a part including the center in the Y direction of the inner surface facing the +X side of the non-ejection channel 52. The dimension of the wide individual electrode 78 in the Y direction is larger than that of the narrow individual electrode 77. In the illustrated example, the wide individual electrode 78 is formed over the entire area in the Y direction on the inner surface facing the +X side of the non-ejection channel 52, and is also formed on the bottom surfaces of the cut-up portions 52a and 52b. Of the first individual electrode 68a and the second individual electrode 68b formed in the same non-ejection channel 52, the wide individual electrodes 78 are separated from each other by the separating groove 52c.

[0064] The wide individual electrode 78 is formed on the upper part of the inner surface facing the +X side of the non-ejection channel 52. Specifically, the upper end edge of the wide individual electrode 78 is located at the upper end opening edge of the non-ejection channel 52. The lower end edge of the wide individual electrode 78 is located higher than the lower end edge of the narrow individual electrode 77. Therefore, the narrow individual electrode 77 and the wide individual electrode 78 overlap each other at least at the upper part and the center part in the Y direction of the inner surface facing the +X side of the non-ejection channel 52. In the illustrated example, the centers in the Y direction of the narrow individual electrode 77 and the wide individual electrode 78 are aligned. However, the centers in the Y direction of the narrow individual electrode 77 and the wide individual electrode 78 may be shifted from each other as long as the upper end edges of the narrow individual electrode 77 and the wide individual electrode 78 are located at the upper end opening edge of the non-ejection channel 52 and overlap each other in a part in the Y direction.

[0065] In the first embodiment, when the dimension in the Z direction of the narrow individual electrode 77 is D1b and the dimension in the Z direction of the wide individual electrode 78 is D2b, it is preferable that the following formula (2) is satisfied. (D1b-D2b)>D2b···(2)

[0066] As shown in FIG. 4, the individual output wiring 69 includes a first individual output wiring 69a and a second individual output wiring 69b. The first individual output wiring 69a extends in the Y direction on the upper surface of the first tail portion 41a. The first individual output wiring 69a is connected to the first individual electrode 68a at the upper opening edge of the non-ejection channel 52. In the illustrated example, the first individual output wiring 69a is connected to a portion of the wide individual electrode 78 of the first individual electrode 68a that protrudes toward the -Y side relative to the narrow individual electrode 77. The first individual output wiring 69a is separated from the common output wiring 66 on the surface of the first tail portion 41a.

[0067] The second individual output wiring 69b extends in the Y direction on the upper surface of the second tail portion 41b. The second individual output wiring 69b is connected to the second individual electrode 68b at the upper opening edge of the non-ejection channel 52. In the illustrated example, the second individual output wiring 69b is connected to a portion of the wide individual electrode 78 of the second individual electrode 68b that protrudes toward the -Y side with respect to the narrow individual electrode 77.

[0068] As shown in FIGS. 4 and 7, the intermediate plate 42 is provided with a common connection wire 71 and individual connection wires 72 as connection wires. The common connection wiring 71 includes a common through wiring 75 and a common lead wiring 76 . The common through wiring 75 is formed on the inner surface of the intermediate common hole 42a. Specifically, the common through wiring 75 is formed on the entire inner surface of the intermediate common hole 42a and is formed over the entire Z direction. The common through wiring 75 is connected to the common output wiring 66 at the lower opening edge of the intermediate common hole 42a.

[0069] The common lead-out wiring 76 is formed on the upper surface of the intermediate plate 42. The common lead-out wiring 76 includes a strip-shaped portion 76a and a common protruding portion 76b. The strip portion 76a extends in the X direction so as to cross between the respective intermediate common holes 42a. The strip portion 76a is connected to the common through wiring 75 at the upper opening edge of the intermediate common hole 42a. That is, the strip portion 76a lumps together the common electrodes 65 via the respective common through wirings 75. It is not necessary that all the common through wirings 75 are connected to one strip portion 76a, and the common through wirings 75 may be lumped together by being shared by, for example, a plurality of strip portions 76a.

[0070] The common protrusions 76b are formed on the upper surface of the intermediate plate 42 at positions overlapping with the respective ejection channels 51 in a plan view. The common protrusions 76b protrude from the strip-shaped portions 76a to the +Y side. In the first embodiment, the common protrusions 76b and the common through-wires 75 are arranged alternately on the upper surface of the intermediate plate 42. Therefore, the total number of the common protrusions 76b is the same as the number of the common through-wires 75 or is one less.

[0071] The individual connection wiring 72 includes a first individual through wiring 81 , a second individual through wiring 82 , and an individual lead wiring 83 . The first individual through wires 81 are formed on the inner surface of the first intermediate individual hole 42b. Specifically, the first individual through wires 81 are formed around the entire inner surface of the first intermediate individual hole 42b and are formed over the entire Z direction. The first individual through wires 81 are connected to the first individual output wires 69a at the lower opening edge of the first intermediate individual hole 42b. The second individual through wires 82 are formed on the inner surface of the second intermediate individual hole 42c. Specifically, the second individual through wires 82 are formed around the entire inner surface of the second intermediate individual hole 42c and are formed over the entire Z direction. The second individual through wires 82 are connected to the second individual output wires 69b at the lower opening edge of the second intermediate individual hole 42c.

[0072] The individual lead-out wiring 83 is formed on the upper surface of the intermediate plate 42. Specifically, the individual lead-out wiring 83 includes a bridging portion 83a and an individual protruding portion 83b. The bridge portion 83a connects between the first individual through-wire 81 located on the -X side of one discharge channel 51 and the second individual through-wire 82 located on the +X side of one discharge channel 51. Specifically, the bridge portion 83a extends inclined toward the +Y side as it approaches the +X side in a plan view. A first end (-Y side end) of the bridge portion 83a is connected to the first individual through-wire 81 at the upper opening edge of the first intermediate individual hole 42b. A second end (+Y side end) of the bridge portion 83a is connected to the second individual through-wire 82 at the upper opening edge of the second intermediate individual hole 42c. This connects the individual electrodes 68a, 68b that face each other in the X direction with one ejection channel 51 in between (the second individual electrodes 68b of the non-ejection channels 52 located on the +X side of one ejection channel 51, and the first individual electrodes 68a of the non-ejection channels 52 located on the -X side of one ejection channel 51).

[0073] The individual protrusion 83b extends from the second end of the bridging portion 83a to the -Y side. That is, the individual protrusion 83b is provided at a position shifted in the X direction with respect to the common protrusion 76b.

[0074] As shown in FIGS. 4 to 7, on the surface plate 43, a common terminal wire 91 and individual terminal wires 92 are formed as terminal wires. The common terminal wiring 91 includes a surface common wiring 91a and a common pad 91b.

[0075] As shown in Figures 4 and 6, the surface common wiring 91a is formed on the inner surface of the surface common hole 43a. Specifically, the surface common wiring 91a is formed around the entire inner surface of the surface common hole 43a and is formed over the entire Z direction. The surface common wiring 91a is connected to the common protrusion 76b at the lower opening edge of the surface common hole 43a. In other words, the total number of the surface common wirings 91a is the same as the total number of the common protrusions 76b, and is set to be the same as or one less than the common through wirings 75. The common pad 91b is formed on the upper surface of the surface plate 43 so as to surround the surface common hole 43a. The common pad 91b is formed in an elliptical shape with the Y direction as the major axis direction in a plan view. The +Y side end of the common pad 91b is connected to the surface common wiring 91a at the upper opening edge of the surface common hole 43a.

[0076] As shown in FIGS. 4 and 7, the individual terminal wiring 92 includes a surface individual wiring 92a and an individual pad 92b. The surface individual wiring 92a is formed on the inner surface of the surface individual hole 43b. Specifically, the surface individual wiring 92a is formed around the entire inner surface of the surface individual hole 43b and is formed over the entire Z direction. The surface individual wiring 92a is connected to the individual protrusion 83b at the lower opening edge of the surface individual hole 43b.

[0077] The individual pads 92b are formed on the upper surface of the surface plate 43 so as to surround the surface individual holes 43b. The individual pads 92b are formed in an elliptical shape with the Y direction as the major axis direction in a plan view. The +Y side end of the individual pads 92b is connected to the surface individual wiring 92a at the upper opening edge of the surface individual hole 43b. The common pads 91b and the individual pads 92b are arranged at both ends of the surface plate 43 in the Y direction, shifted by half a pitch with respect to the arrangement pitch of the ejection channels 51 (or non-ejection channels 52).

[0078] <Nozzle plate 33> As shown in Figs. 4 and 6, the nozzle plate 33 covers the lower surface of the actuator plate 41 and the lower surface of the flow path plate 31 together. The nozzle plate 33 is bonded to the lower surface of the actuator plate 41 and the lower surface of the flow path plate 31 via an adhesive or the like. As a result, the nozzle plate 33 covers the lower end openings of the inlet common flow path 31b and the outlet common flow path 31c and the lower end openings of the channels 51 and 52 together. The nozzle plate 33 is formed of a resin material (polyimide, etc.). However, the nozzle plate 33 may have a single-layer structure or a laminated structure made of a resin material (polyimide, etc.), glass, silicon, etc., in addition to a metal material (SUS, Ni-Pd, etc.).

[0079] As shown in Figures 6 and 8, the nozzle plate 33 is formed with a plurality of nozzle holes 33a penetrating the nozzle plate 33 in the Z direction. The nozzle holes 33a are formed, for example, in a tapered shape in which the inner diameter gradually decreases from the top to the bottom. The nozzle holes 33a are arranged at intervals in the X direction. Each nozzle hole 33a is individually connected to a corresponding discharge channel 51. In the illustrated example, the upper end opening of each nozzle hole 33a opens at the center of the discharge channel 51 in the Y direction.

[0080] <Flow passage cover 34> 3 and 6, the flow path cover 34 sandwiches the flow path plate 31 and the head chip 32 between the flow path cover 34 and the nozzle plate 33. The flow path cover 34 includes a cover base 95, an inlet port 96, and an outlet port 97. The cover base 95 is a rectangular plate whose planar outer shape is formed to be the same as that of the flow path plate 31. The cover base 95 is overlaid on the upper surfaces of the flow path plate 31 and the head chip 32. The cover base 95 is bonded to the upper surfaces of the flow path plate 31 and the head chip 32 via an adhesive or the like, and is fastened to the flow path plate 31 with screws or the like. As a result, the cover base 95 closes the upper end openings of the inlet common flow path 31b and the outlet common flow path 31c.

[0081] A slit 95a is formed in the center of the cover base 95 in the Y direction. The slit 95a penetrates the cover base 95 in the Z direction and extends in the X direction. The slit 95a is formed at a position overlapping the center of the head chip 32 (excluding the outer periphery) in a plan view. That is, the dimension of the slit 95a in the Y direction is smaller than the dimension of the head chip 32 in the Y direction. The dimension of the slit 95a in the X direction is smaller than the dimension of the head chip 32 in the X direction. The slit 95a exposes at least a part of each of the pads 91b, 92b on the upper surface of the surface plate 43. In the illustrated example, the cover base 95 covers the outer periphery of the surface plate 43 with the opening edge of the slit 95a, and exposes the entirety of each of the pads 91b, 92b through the slit 95a.

[0082] The inlet port 96 is located at the end of the cover base 95 on the +Y side and the +X side. The inlet port 96 protrudes upward from the cover base 95. The inlet port 96 communicates with the inlet common flow channel 31b through the +X side end of the inlet common flow channel 31b (the portion protruding toward the chip accommodation section 31a). That is, the ink flowing through the ink supply tube 21 is supplied to the inlet common flow channel 31b through the inlet port 96. The outlet port 97 is located at the end of the cover base 95 on the -Y side and the -X side. The outlet port 97 protrudes upward from the cover base 95. The outlet port 97 communicates with the outlet common flow channel 31c through the -X side end of the outlet common flow channel 31c (the portion protruding toward the chip housing portion 31a). That is, the ink flowing through the outlet common flow channel 31c is discharged to the ink discharge tube 22 through the outlet port 97.

[0083] 6, the flexible printed circuit board 35 is pressure-bonded to the upper surface of the surface plate 43 through the slit 95a. The flexible printed circuit board 35 is connected to the pads 91b, 92b on the upper surface of the surface plate 43. The flexible printed circuit board 35 is pulled out upward and then connected to a control unit.

[0084] [Printer 1 operation method] Next, a case where characters, figures, etc. are recorded on a recording medium P using the printer 1 configured as described above will be described below. 1 are each fully filled with ink of a different color. Also, the ink in the ink tanks 4 is filled in the inkjet head 5 via the ink circulation mechanism 6.

[0085] When the printer 1 is operated in this initial state, the recording medium P is conveyed to the +X side while being sandwiched between the rollers 11 and 12 of the conveying mechanisms 2 and 3. At the same time, the carriage 29 moves in the Y direction, causing the inkjet head 5 mounted on the carriage 29 to move back and forth in the Y direction. While the inkjet heads 5 are moving back and forth, ink is appropriately ejected from each inkjet head 5 onto the recording medium P. In this way, characters, images, etc. can be recorded on the recording medium P.

[0086] The movement of each ink-jet head 5 will now be described in detail. In the inkjet head 5 of the circulation type side shoot type as in the first embodiment, first, the pressurizing pump 24 and the suction pump 25 shown in FIG. 2 are operated to circulate ink in the circulation flow path 23. In this case, the ink flowing in the ink supply pipe 21 is supplied into the inlet common flow path 31b through the inlet port 96. The ink supplied to the inlet common flow path 31b is distributed to each ejection channel 51 through the +Y side opening of each ejection channel 51, and then flows through each ejection channel 51 to the -Y side. After that, the ink is discharged to the outlet common flow path 31c through the -Y side opening of each ejection channel 51. The ink discharged to the outlet common flow path 31c flows into the ink ejection pipe 22 through the outlet port 97, and is returned to the ink tank 4. In this way, the ink can be circulated between the inkjet head 5 and the ink tank 4.

[0087] Then, when the inkjet head 5 starts to move back and forth by the movement of the carriage 29 (see FIG. 1), a driving voltage is applied between the common electrode 65 and the individual electrodes 68 via the flexible printed circuit board 35. At this time, the driving voltage is applied with the common electrode 65 set to a reference potential GND and the individual electrodes 68 set to a driving potential Vdd. Then, a potential difference is generated in the X direction between the common electrode 65 and the individual electrodes 68, which face each other across the driving wall 53. Due to the potential difference generated in the X direction, an electric field is generated in the actuator plate 41 in a direction perpendicular to the polarization direction (Z direction). As a result, the actuator plate 41 undergoes thickness slip deformation in the Z direction due to the shear mode. Specifically, thickness slip deformation occurs in the two driving walls 53 that define the ejection channel 51, and these two driving walls 53 deform so as to protrude toward the non-ejection channel 52 side. That is, since the actuator plate 41 of the first embodiment is composed of two piezoelectric substrates that are polarized in the thickness direction (Z direction) and are laminated, when a drive voltage is applied, the actuator plate 41 bends and deforms into a V shape centered on the middle position in the Z direction of the drive wall 53. This causes the ejection channel 51 to deform as if it is bulging.

[0088] Thereafter, when the driving voltage is set to zero, the actuator plate 41 returns to its original state, and the volume within the ejection channel 51 attempts to return to its original state. In the process of the actuator plate 41 returning to its original state, the pressure within the ejection channel 51 increases, and the ink within the ejection channel 51 is ejected to the outside through the nozzle hole 33a. The ink ejected to the outside lands on the recording medium P, and print information is recorded on the recording medium P.

[0089] <Method of Manufacturing Discharge Unit 30> Next, a description will be given of a method for manufacturing the above-mentioned discharge unit 30. FIG 9 is a flowchart for explaining a method for manufacturing the discharge unit 30. 9, the manufacturing method of the discharge unit 30 includes an actuator processing step S10, an intermediate plate processing step S20, a surface plate processing step S30, a grinding step S40, a cutting step S50, an assembly step S60, and a third joining step S70. Among the manufacturing steps of the discharge unit 30, the actuator processing step S10, the intermediate plate processing step S20, the surface plate processing step S30, and the grinding step S40 correspond to manufacturing steps of the head chip 32. In the following description, for convenience, an example will be described in which the head chip 32 is manufactured at the chip level.

[0090] Fig. 10 to Fig. 16 are process diagrams for explaining the actuator processing step S10. Among Fig. 10 to Fig. 15, Fig. 10, Fig. 11 and Fig. 16 are end views corresponding to Fig. 8, and Fig. 12 to Fig. 15 are cross-sectional views corresponding to Fig. 6 or Fig. 7. 10, a mask pattern 100 is formed on the upper surface of the actuator plate 41. Specifically, after a mask material (e.g., a laminate film) is formed on the upper surface of the actuator plate 41, the mask material is patterned using a photolithography technique. At this time, the mask pattern 100 is formed in which at least the formation regions of the common output wiring 66 and the individual output wiring 69 are opened in the mask material. Note that the dimension (pre-processing dimension) of the actuator plate 41 in the Z direction at the time of the actuator processing step S10 is larger than the dimension (post-processing dimension) of the actuator plate 41 when completed as the head chip 32.

[0091] In the channel forming step S12 shown in FIG. 11, the formation regions of the discharge channel 51 and the non-discharge channel 52 in the actuator plate 41 are processed by the first dicer 110. As a result, the first recess 101 that will later become the discharge channel 51 and the second recess 102 that will later become the non-discharge channel 52 are formed. The first dicer 110 is formed in a disk shape when viewed from the X direction. Therefore, as shown in FIG. 12 and FIG. 13, the first recess 101 and the second recess 102 are formed in a convex arc shape facing downward when viewed from the X direction. The first recess 101 and the second recess 102 have gradually reduced dimensions in the Y direction as they go downward. That is, in the first recess 101 and the second recess 102, the dimension in the Y direction of the upper end opening (first opening) is larger than the dimension in the Y direction of the lower end opening (second opening). The advance amount of the first dicer 110 in the Z direction is set to be larger than the dimension after processing of the actuator plate 41 and smaller than the dimension before processing of the actuator plate 41. That is, after the channel forming step S12, neither the first recess 101 nor the second recess 102 penetrates the actuator plate 41.

[0092] In the channel forming step S12 of the first embodiment, the travel distance of the first dicer 110 in the Y direction is made smaller in the formation region of the non-ejection channels 52 than in the formation region of the ejection channels 51. As a result, the first recess 101 is formed with a first central extension 101a located in the center in the Y direction and a first cut-up portion 101b continuing on both sides in the Y direction of the first central extension 101a. Similarly, the second recess 102 is formed with a second central extension 102a located in the center in the Y direction and a second cut-up portion 102b continuing on both sides in the Y direction of the second central extension 102a.

[0093] The first central extending portion 101a has a dimension in the Y direction larger than that of the second recess 102. In the illustrated example, the first central extending portion 101a protrudes from the second recess 102 on both sides in the Y direction. In the second recess 102, the second central extending portion 102a is a portion corresponding to the through portion 52a of the non-ejection channel 52. In the second recess 102, the second cut-out portion 102b is a portion corresponding to the cut-out portion 52b of the non-ejection channel 52.

[0094] In the first wiring formation process S13, common wiring 61 and individual wiring 62 are formed as drive wiring. In the first wiring formation process S13, oblique deposition is performed twice from the upper surface side of the actuator plate 41 to form a film of an electrode material. Specifically, the first wiring formation process S13 includes a narrow electrode formation process (first electrode formation process) S13a and a wide electrode formation process (second electrode formation process) S13b.

[0095] In the narrow electrode forming process S13a, a film of an electrode material is formed from above the actuator plate 41 to form a narrow common electrode 65a in the first recess 101 and a narrow individual electrode 77 in the second recess 102. In the narrow electrode forming process S13a, a metal mask 105 is first set on the upper surface of the actuator plate 41 via a mask pattern 100. Next, an electrode material is obliquely evaporated from an oblique direction with respect to the normal direction of the upper surface of the actuator plate 41 when viewed from the Y direction. Specifically, from an evaporation source arranged on the +X side of the actuator plate 41, oblique evaporation is performed on the inner surfaces of each of the recesses 101 and 102 facing the +X side. Then, from an evaporation source arranged on the -X side of the actuator plate 41, oblique evaporation is performed on the inner surfaces of each of the recesses 101 and 102 facing the -X side.

[0096] A mask opening 105a is formed in the metal mask 105. In plan view, the mask opening 105a is open all over the X direction in a portion of the actuator plate 41 that overlaps the entire channel row 46. Meanwhile, in plan view, the mask opening 105a exposes a portion including the center in the Y direction of each of the recesses 101, 102. In this case, the dimension of the mask opening 105a in the Y direction is smaller than the dimension of the second central extension portion 102a.

[0097] FIG. 17 is an explanatory diagram for explaining the deposition depth D. 17, when oblique deposition is performed on the inner side surface (film formation surface) of each of the recesses 101, 102, the deposition depth D is expressed by the following formula (3): In formula (3), r is the thickness of the mask pattern 100, s is the width (dimension in the X direction) of the upper opening of each of the recesses 101, 102, θ is the angle that the upper surface of the actuator plate 41 makes with respect to the vertical direction (the tilt angle of the actuator plate 41), and β is the incident angle of the electrode material from the deposition source into the recesses 101, 102. tan(β-θ)=s / (D+r) (3) From equation (3), the deposition depth D is expressed as equation (4). D = s / tan(β-θ)-r (4)

[0098] In the narrow electrode forming process S13a, the deposition depth D is set for all the recesses 101, 102 based on formula (4) so ​​as to be greater than the post-machining dimension of the actuator plate 41 and less than the pre-machining dimension of the actuator plate 41. In this state, oblique deposition is performed using both the metal mask 105 and the mask pattern 100 as masks, so that the electrode material is deposited on the inner surface of each of the recesses 101, 102. In the first embodiment, the mask opening 105a of the metal mask 105 constitutes the mask opening of the first electrode mask, and the portion of the mask pattern 100 exposing the first recess 101 and the second recess 102 constitutes the second mask opening of the second electrode mask.

[0099] As shown in FIGS. 14 and 15, in the wide electrode forming process S13b, an electrode material is deposited from above the actuator plate 41. As a result, the wide common electrode 65b is formed in the first recess 101, and the wide individual electrodes 78 are formed in the second recess 102. In addition to the wide common electrode 65b and the wide individual electrodes 78, the wide electrode forming process S13b also forms various output wirings 66, 69 on the upper surface of the actuator plate 41. Specifically, the metal mask 105 is removed, and oblique deposition is performed using only the mask pattern 100 as a mask. In the wide electrode forming process S13b, the deposition depth D is set to be smaller than the post-processing dimension of the actuator plate 41 for all the recesses 101, 102 based on formula (4).

[0100] 16, the individual electrodes 68a, 68b (wide individual electrodes 78) formed in one second recess 102 are divided. Specifically, a second dicer 115 is advanced into the center of the second recess 102 in the X direction. At this time, the dimension of the second dicer 115 in the X direction is smaller than the dimension of the second recess 102 in the X direction. Therefore, the individual electrodes 68a, 68b are divided at the bottom surface of the second recess 102.

[0101] 18 to 20 are process drawings for explaining the intermediate plate machining step S20, and are cross-sectional views corresponding to FIG. 18, an intermediate common hole 42a and intermediate individual holes 42b, 42c are formed in the intermediate plate 42. Specifically, a laser beam is irradiated from the upper surface side of the intermediate plate 42 to penetrate the intermediate plate 42. The intermediate common hole 42a and the intermediate individual holes 42b, 42c may be formed by sandblasting, etching, or the like.

[0102] In the first bonding step S22 shown in FIG.

[0103] 20, a common connection wiring 71 and individual connection wiring 72 are formed on the intermediate plate 42 as connection wiring. Specifically, an electrode material is deposited by vapor deposition or the like from the upper surface side of the intermediate plate 42. As a result, a common through wiring 75 is formed in the intermediate common hole 42a, and individual through wirings 81, 82 are formed in the intermediate individual holes 42a, 42b. In addition, a common lead-out wiring 76 and individual lead-out wiring 83 are formed on the upper surface of the intermediate plate 42 through a mask pattern (not shown).

[0104] 21 to 23 are process drawings for explaining the surface plate machining step S30, and are cross-sectional views corresponding to FIG. 21, a surface common hole 43a and surface individual holes 43b are formed in the surface plate 43. Specifically, sandblasting or the like is performed from the upper surface side of the surface plate 43 to penetrate the surface plate 43. The surface common hole 43a and the surface individual holes 43b may be formed by a laser, etching, or the like.

[0105] In the second joining step S32 shown in FIG. 22, the surface plate 43 is attached to the upper surface of the intermediate plate .

[0106] 23, a common terminal wiring 91 and individual terminal wiring 92 are formed on the surface plate 43 as terminal wiring. Specifically, a film of an electrode material is formed by performing deposition or the like from the upper surface side of the surface plate 43. As a result, a surface common wiring 91a is formed in the surface common hole 43a, and a surface individual wiring 92a is formed in the surface individual hole 43b. In addition, a common pad 91b and an individual pad 92b are formed on the upper surface of the surface plate 43 through a mask pattern (not shown).

[0107] FIG. 24 is a process diagram for explaining the grinding step S40, and is an end view corresponding to FIG. 24, a grinding process is performed on the lower surface of the actuator plate 41. Specifically, the actuator plate 41 is ground until the first recess 101 and the second recess 102 open on the lower surface of the actuator plate 41.

[0108] FIG. 25 is a process diagram for explaining the cutting step S50, and is a cross-sectional view corresponding to FIG. 25, both ends in the Y direction of the laminate of the actuator plate 41, the intermediate plate 42, and the surface plate 43 are cut. Specifically, the laminate is cut so as to remove the first cut-up portion 101b. As a result, both ends in the Y direction of the first recess 101 are opened, and the above-mentioned discharge channel 51 is formed. Through the above steps, the head chip 32 is completed.

[0109] Thereafter, in an assembly step S60, head chip 32 is assembled to flow path plate 31. Specifically, head chip 32 is fitted into chip housing portion 31a so that the lower surface of flow path plate 31 and the lower surface of head chip 32 are flush with each other.

[0110] Next, in a third bonding process S70, the nozzle plate 33 is attached so as to collectively cover the lower surface of the flow path plate 31 and the lower surface of the head chip 32. Thereafter, the flow path cover 34 is attached to the upper surface of the flow path plate 31. Through the above steps, the discharge unit 30 is completed.

[0111] When the head chip 32 is manufactured at the wafer level, the actuator plate wafer, the intermediate plate wafer, and the surface plate wafer are subjected to the same processes as the actuator processing process S10, the intermediate plate processing process S20, the surface plate processing process S30, and the grinding process S40 to form a wafer stack. The wafer stack is then diced into individual pieces to extract the head chips 32. The head chips 32 extracted from the wafer stack are then subjected to the assembly process S60 and subsequent processes to complete the discharge unit 30.

[0112] Thus, the head chip 32 of the first embodiment includes an actuator plate 41 having an upper end opening (a first opening that opens on a first surface facing a first side in the thickness direction) and a lower end opening (a second opening on a second surface facing a second side in the thickness direction), and in which channels (e.g., non-ejection channels 52) extending in the Y direction are formed. The actuator plate 41 is provided with individual electrodes (driving electrodes) 68 formed on the inner surfaces of the non-ejection channels 52, and individual output wiring (driving wiring) 69 formed on the upper surface (first surface) of the actuator plate 41 and connected to the individual electrodes 68 through the edge of the upper end opening. Furthermore, the individual electrode 68 includes a narrow individual electrode (first electrode) 77 that extends in the Z direction (thickness direction) from the upper opening edge of the non-ejection channel 52 and has a dimension in the Y direction smaller than that of the lower opening, and a wide individual electrode 78 that extends in the Z direction from the upper opening edge of the non-ejection channel 52 while partially overlapping with the narrow individual electrode 77, and has a dimension in the Z direction smaller than that of the narrow individual electrode 77 and a dimension in the Y direction larger than that of the narrow individual electrode 77.

[0113] According to this configuration, by making the Y-direction dimension of the narrow individual electrodes 77, which are large in the Z direction, smaller than that of the wide individual electrodes 78, it is possible to suppress the formation of an electrode on the portion of the lower end opening edge of the non-ejection channel 52 facing the Y direction. Therefore, when opening the lower end opening of the non-ejection channel 52 by grinding the lower surface of the actuator plate 41, it is possible to suppress the electrode near the lower end opening edge from being removed and remaining as a burr. In the first embodiment, the ejection channel 51 is formed by the first recess 101, the Y-direction dimension of the upper end opening is larger than the Y-direction dimension of the lower end opening. Therefore, the above-mentioned action and effect are similar to those of the ejection channel 51. In addition, the wide individual electrode 78 (wide common electrode 65b) which is larger in the Y direction than the narrow individual electrode 77 (narrow common electrode 65a) and smaller in the Z direction is formed so as to overlap a part of the narrow individual electrode 77 (narrow common electrode 65a). This makes it easy to ensure the area of ​​the entire drive electrode. This makes it easy to ensure the electrostatic capacitance generated in the drive wall 53 when a voltage is applied, and therefore makes it easy to ensure the output when ink is ejected.

[0114] In the head chip 32 of the first embodiment, the narrow common electrode 65a is formed over the entire length of the ejection channel 51 in the Z direction, and the narrow individual electrode 77 is formed over the entire length of the non-ejection channel 52 in the Z direction. According to this configuration, it is possible to suppress the dimensional variation of the narrow common electrode 65a and the narrow individual electrode 77 for each channel 51, 52, and therefore the area variation of the drive electrode for each channel 51, 52. Therefore, when a voltage is applied by the drive electrode, it is easy to equalize the electrostatic capacitance generated in the drive wall 53 corresponding to each ejection channel 51. As a result, it is possible to suppress the variation in the ejection performance (speed) for each ejection channel 51.

[0115] In the head chip 32 of the first embodiment, when the Z-direction dimensions of the narrow common electrode 65a and the narrow individual electrode 77 are D1a and D1b, respectively, and the Z-direction dimensions of the wide common electrode 65b and the wide individual electrode 78 are D2a and D2b, respectively, the configuration satisfies the above formula (1) or formula (2). According to this configuration, it is possible to suppress variation in the Z direction of the wide common electrode 65b and the wide individual electrode 78 between the channels 51, 52, and therefore it is possible to suppress variation in the area of ​​the drive electrodes between the channels 51, 52. Therefore, it is possible to suppress variation in the ejection performance (speed) between the channels 51, 52.

[0116] Since the inkjet head 5 and printer 1 of the first embodiment include the head chip 32 described above, it is possible to provide an inkjet head 5 and printer 1 that are high in performance and excellent in reliability.

[0117] In the head chip 32 of the first embodiment, in the narrow electrode formation process S13a, deposition is performed on the inner surfaces of the recesses 51, 52 so that at least a portion of the narrow common electrode 65a and the narrow individual electrodes 77 are larger than the dimensions of the channels 51, 52 in the Z direction. According to this configuration, after the grinding step S40, at least a portion of the narrow common electrode 65a and the narrow individual electrodes 77 are formed over the entire area in the Z direction on the inner surface of the channels 51, 52. This makes it possible to suppress dimensional variations in the narrow common electrode 65a and the narrow individual electrodes 77 for each of the channels 51, 52. Therefore, when a voltage is applied by the drive electrode, it becomes easier to uniformize the electrostatic capacitance generated in the drive walls 53 corresponding to each of the channels 51, 52. As a result, it is possible to suppress variations in the ejection performance (speed) for each of the channels 51, 52.

[0118] In the head chip 32 of the first embodiment, in the wide electrode formation process S13b, deposition is performed on the inner surfaces of the recesses 101, 102 so that the entire wide common electrode 65b and the wide individual electrodes 78 are smaller than the dimensions of the channels 51, 52 in the Z direction. According to this configuration, after the grinding step S40, it is possible to prevent the entirety of the wide common electrode 65b and the wide individual electrodes 78 from reaching the lower end opening edges of the channels 51, 52. This makes it possible to prevent the electrodes near the lower end opening edges from being removed and remaining (the occurrence of burrs) after the grinding step S40.

[0119] In head chip 32 of the first embodiment, narrow electrode forming process S13a is performed prior to wide electrode forming process S13b. According to this configuration, if the narrow common electrode 65a and the narrow individual electrode 77 reach the portion of the lower end opening edge of each channel 51, 52 facing the Y direction, it can be determined in advance that the product is defective at that point. As a result, it is not necessary to carry out post-processing for products determined to be defective, and therefore manufacturing efficiency can be improved.

[0120] Second embodiment FIG. 26 is a cross-sectional view of head chip 32 according to the second embodiment, which corresponds to FIG. In head chip 32 according to the second embodiment, as shown in FIG. 26, dimension D1a of narrow common electrode 65a and dimension D2a of wide common electrode 65b satisfy the following formula (5). (D1a-D2a) <D2a···(5)

[0121] FIG. 27 is a cross-sectional view of head chip 32 according to the second embodiment, which corresponds to FIG. As shown in FIG. 27, the dimension D1b of the narrow individual electrode 77 and the dimension D2b of the wide individual electrode 78 satisfy the following formula (6). (D1b-D2b) <D2b···(6)

[0122] In the head chip 32 of the second embodiment, when the Z-direction dimensions of the narrow common electrode 65a and the narrow individual electrode 77 are D1a and D1b, respectively, and the Z-direction dimensions of the wide common electrode 65b and the wide individual electrode 78 are D2a and D2b, respectively, the configuration satisfies the above formula (5) or formula (6). This configuration makes it easy to ensure the area of ​​the entire drive electrode between channels 51, 52. Therefore, when a voltage is applied by the drive electrode, it becomes easy to ensure the electrostatic capacitance generated in drive wall 53, and it becomes easy to ensure the output when ink is ejected.

[0123] Third embodiment FIG. 28 is an end view of head chip 32 according to the third embodiment, which corresponds to FIG. 27, in head chip 32 according to the third embodiment, wide common electrode 65b and wide individual electrode 78 are formed as a lower layer, and narrow common electrode 65a and narrow individual electrode 77 are formed as an upper layer. That is, in head chip 32 according to the third embodiment, after performing wide electrode formation process S13b using only mask pattern (mask for second electrode) 100, narrow electrode formation process S13a is performed using mask pattern 100 and metal mask (mask for first electrode) 105, to form the electrodes.

[0124] According to this configuration, since the metal mask 105, which is set separately on the actuator plate 41, involves the risk of foreign matter adhering to the actuator plate 41, the wide electrode formation process S13b is performed before setting the metal mask 105, so that the wide common electrode 65b, the wide individual electrode 78, and the various extraction wirings 66, 69 can be formed with high precision.

[0125] (Fourth embodiment) 29 is an exploded perspective view of head chip 200 according to the fourth embodiment. Head chip 200 according to the fourth embodiment differs from the above-described embodiments in that head chip 200 is provided with a common inlet flow path and a common outlet flow path. 29 includes a nozzle plate 201, an actuator plate 202, and a cover plate 203. The head chip 200 has a configuration in which the nozzle plate 201, the actuator plate 202, and the cover plate 203 are stacked in this order in the Z direction.

[0126] The actuator plate 202 is formed with a channel row 210. The channel row 210 has ejection channels 211 that are filled with ink, and non-ejection channels 212 that are not filled with ink. The channels 211, 212 are arranged alternately in the actuator plate 41 with a gap therebetween in the X direction.

[0127] FIG. 30 is a cross-sectional view corresponding to the line XXX-XXX in FIG. 30, the discharge channel 211 is formed in a circular arc shape that protrudes downward when viewed from the X direction. The discharge channel 211 opens on the upper and lower surfaces of the actuator plate 202. The dimension of the discharge channel 211 in the Y direction decreases downward. Therefore, the dimension of the discharge channel 211 in the Y direction at the upper end opening is larger than the dimension of the discharge channel 211 in the Y direction at the lower end opening.

[0128] FIG. 31 is a cross-sectional view corresponding to the line XXXI-XXXI in FIG. As shown in Fig. 31, the non-ejection channels 212 extend linearly in the Y direction while penetrating the actuator plate 202 in the Z direction. As shown in Fig. 29, the portions of the actuator plate 202 located between adjacent ejection channels 211 and non-ejection channels 212 each constitute a driving wall 215.

[0129] 29 to 31, the cover plate 203 is laminated by adhesion or the like on the upper surface of the actuator plate 202 so as to cover the upper end openings of the channels 211, 212. As shown in Fig. 29, an inlet common channel 220 is formed in the cover plate 203 at a position overlapping the -Y side end of the channel row 210 in a plan view. The inlet common channel 220 extends in the X direction, for example, by a length spanning the channel row 210, and opens at the upper surface of the cover plate 203. In the inlet common flow channel 220, an inlet slit 22 is formed at a position overlapping with the discharge channel 211 in a plan view. The inlet slit 221 individually communicates between the -Y side end of each discharge channel 211 and the inside of the inlet common flow channel 220.

[0130] An outlet common channel 225 is formed in the cover plate 203 at a position overlapping in plan view with the +Y side end of the channel row 210. The outlet common channel 225 extends in the X direction, for example, by a length spanning the channel row 210, and opens at the upper surface of the cover plate 203. In the outlet common flow path 225, an outlet slit 226 is formed at a position overlapping with the non-ejection channel 212 in a plan view. The outlet slit 226 separately communicates between the +Y side end of each ejection channel 211 and the inside of the outlet common flow path 225. Therefore, the inlet slit 221 and the outlet slit 226 communicate with each ejection channel 211, but do not communicate with the non-ejection channel 212.

[0131] 29, the nozzle plate 201 is laminated on the lower surface of the actuator plate 202 by adhesion or the like. Nozzle holes 201a are formed in the nozzle plate 201 at positions overlapping with the centers of the ejection channels 211 in the Y direction. An intermediate plate (not shown) may be interposed between the nozzle plate 201 and the actuator plate 202. In this case, the ejection channels 211 and the nozzle holes 201a are communicated with each other through communication holes formed in the intermediate plate.

[0132] Next, the drive wiring formed on the actuator plate 202 will be described. As shown in FIG. 30, the common wiring 230 includes a common electrode 231 and a common pad 232. The common electrodes 231 are formed on inner surfaces facing each other in the X direction among the inner surfaces of the ejection channel 211. The common electrodes 231 each include a narrow common electrode 231a and a wide common electrode 231b.

[0133] The narrow common electrode 231a is an electrode corresponding to the lower layer of the common electrode 231. The narrow common electrode 231a extends in a strip shape in the Z direction, for example, with a uniform dimension in the Y direction, on a portion including the center portion in the Y direction of the inner surface of the ejection channel 211. Specifically, the dimension in the Y direction of the narrow common electrode 231a is smaller than the dimension in the Y direction of the ejection channel 211. In the illustrated example, the dimension in the Y direction of the wide common electrode 231a is smaller than the lower end opening of the ejection channel 211. Therefore, both end edges in the Y direction of the narrow common electrode 231a are separated from the portion of the lower end opening edge of the ejection channel 211 facing the Y direction and the bottom surface of the ejection channel 211.

[0134] The narrow common electrode 231a is formed over the entire area in the Z direction on the inner surface of the discharge channel 51. Specifically, the upper edge of the narrow common electrode 231a is located at the upper opening edge of the discharge channel 211. The lower edge of the narrow common electrode 231a is located at the lower opening edge of the discharge channel 211.

[0135] The wide common electrode 231b is an electrode that corresponds to the upper layer of the common electrode 231. A part of the wide common electrode 231b overlaps the narrow common electrode 231a. The wide common electrode 231b has a larger dimension in the Y direction than the narrow common electrode 231a. In the illustrated example, the wide common electrode 231b is formed over the entire area of ​​the ejection channel 211 in the Y direction.

[0136] The wide common electrode 231b is formed on the upper part of the inner side surface of the discharge channel 211. Specifically, the upper edge of the wide common electrode 231b is located at the upper opening edge of the discharge channel 211. The lower edge of the wide common electrode 231b is located higher than the lower edge of the narrow common electrode 231a. Therefore, the narrow common electrode 231a and the wide common electrode 231b overlap each other at least in the upper part and the center in the Y direction of the inner side surface of the discharge channel 211.

[0137] FIG. 32 is a plan view of an actuator plate 202 according to the fourth embodiment. 32, the common pad 232 is formed on a portion (hereinafter referred to as tail portion 202a) located on the -Y side of the ejection channel 211 on the upper surface of the actuator plate 202. The common pad 232 is provided in the tail portion 202a corresponding to each ejection channel 211. Each common pad 232 extends linearly in the Y direction relative to the corresponding ejection channel 211. The +Y side end of the common pad 232 is connected to the common electrode 231 (wide common electrode 231b) at the upper opening edge of the ejection channel 211.

[0138] The individual wiring 235 includes an individual electrode 236 and an individual pad 237 . The individual electrodes 236 are formed separately on inner surfaces facing each other in the X direction among the inner surfaces of the non-ejection channels 212. In the following, an individual electrode 236 formed on the inner surface facing the -X side among the inner surfaces of the non-ejection channels 212 will be described as an example.

[0139] The individual electrodes 236 each include a narrow individual electrode 236a and a wide common electrode 236b. The narrow individual electrode 236a is an electrode corresponding to the lower layer among the individual electrodes 236. The narrow individual electrode 236 extends in a band shape in the Z direction, for example, with a uniform dimension in the Y direction, in a portion including the center in the Y direction of the inner surface facing the -X side of the non-ejection channel 212. Specifically, the dimension in the Y direction of the narrow individual electrode 236 is smaller than the dimension in the Y direction at the lower end opening of the ejection channel 212.

[0140] The narrow individual electrode 236a is formed over the entire area in the Z direction on the inner surface facing the +X side of the non-ejection channel 212. Specifically, the upper edge of the narrow individual electrode 236a is located at the upper opening edge of the non-ejection channel 212. The lower edge of the narrow individual electrode 236a is located at the lower opening edge of the non-ejection channel 212. However, it is sufficient that at least the upper edge of the narrow individual electrode 236a is located at the upper opening edge of the non-ejection channel 212.

[0141] The wide individual electrode 236b is an electrode that corresponds to the upper layer of the individual electrodes 236. A part of the wide individual electrode 236b is overlapped with the narrow individual electrode 236a. The wide individual electrode 236b is formed on a part including the center in the Y direction of the inner surface facing the +X side of the non-ejection channel 212. The dimension of the wide individual electrode 236b in the Y direction is larger than that of the narrow individual electrode 236a. In the illustrated example, the wide individual electrode 236a is formed on the inner surface of the non-ejection channel 52 over the entire area in the Y direction.

[0142] The wide individual electrode 236b is formed on the upper part of the inner surface facing the +X side of the non-ejection channel 212. Specifically, the upper edge of the wide individual electrode 236b is located at the upper opening edge of the non-ejection channel 212. The lower edge of the wide individual electrode 236b is located higher than the lower edge of the narrow individual electrode 236a. Therefore, the narrow individual electrode 236a and the wide individual electrode 236b overlap each other at least in the upper part and the center in the Y direction of the inner surface facing the +X side of the non-ejection channel 212.

[0143] As shown in FIG. 32, the individual pad 237 is formed on the upper surface of the tail portion 202a at a portion located on the -Y side of the common pad 232. The individual pad 237 is in a strip shape extending in the X direction. The individual pad 237 connects the individual electrodes 236 (wide individual electrodes 236b) facing each other in the X direction with the ejection channel 211 therebetween at the upper end opening edges of the non-ejection channels 212 facing each other in the X direction with the ejection channel 211 therebetween. In the tail portion 202a, a partition groove 202b is formed in a portion located between the common pad 232 and the individual pad 237. The partition groove 202b extends in the X direction in the tail portion 202a. The partition groove 202b separates the common pad 232 and the individual pad 237.

[0144] A flexible printed circuit board 240 is pressure-bonded to the tail portion 202a. The flexible printed circuit board 240 is connected to the common pad 232 and the individual pads 237 on the upper surface of the tail portion 202a.

[0145] The fourth embodiment can also achieve the same effects as the above-mentioned embodiments. In the fourth embodiment, the narrow common electrode 231a and the narrow individual electrode 236a are formed in the lower layer, and the wide common electrode 231b and the wide individual electrode 236b are formed in the upper layer, but the present invention is not limited to this configuration. The narrow common electrode 231a and the narrow individual electrode 236a may be formed in the upper layer, and the wide common electrode 231b and the wide individual electrode 236b may be formed in the lower layer.

[0146] (Other variations) The technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure. For example, in the above embodiment, the inkjet printer 1 has been described as an example of a liquid jet recording apparatus, but the liquid jet recording apparatus is not limited to a printer. For example, the liquid jet recording apparatus may be a fax machine, an on-demand printer, or the like. In the above-described embodiment, a configuration in which the inkjet head moves relative to the recording medium during printing (so-called shuttle machine) has been described as an example, but the present disclosure is not limited to this configuration. The configuration according to the present disclosure may be adopted in a configuration in which the recording medium moves relative to the inkjet head while the inkjet head is fixed (so-called fixed head machine). In the above embodiment, the recording medium P is paper, but the present invention is not limited to this configuration. The recording medium P is not limited to paper, and may be a metal material, a resin material, or a food product. In the above-described embodiment, the liquid ejection head is mounted on the liquid ejection recording device, but the present invention is not limited to this configuration. In other words, the liquid ejected from the liquid ejection head is not limited to the liquid that is to be landed on the recording medium, and may be, for example, a medicinal liquid to be mixed in a medicine, a food additive such as a seasoning or a fragrance to be added to food, or an aromatic to be sprayed into the air.

[0147] In the above embodiment, the configuration has been described in which the Z direction coincides with the direction of gravity, but the present invention is not limited to this configuration, and the Z direction may be aligned with the horizontal direction. In the above-described embodiment, the actuator plate 41 is deformed in a direction in which the volume of the ejection channel 51 is expanded by application of a voltage, and then the actuator plate 41 is restored to its original state to eject ink (so-called pull shot). However, the present disclosure is not limited to this configuration. The head chip according to the present disclosure may be configured to eject ink by deforming the actuator plate 41 in a direction in which the volume of the ejection channel 51 is reduced by application of a voltage (so-called push shot). When push shot is performed, the actuator plate 41 (drive wall 53) is deformed so as to bulge toward the inside of the ejection channel 51 by application of a drive voltage. As a result, the volume inside the ejection channel 51 decreases, and the pressure inside the ejection channel 51 increases, and the ink inside the ejection channel 51 is ejected to the outside through the nozzle hole 33a. When the drive voltage is set to zero, the actuator plate 41 is restored. As a result, the volume inside the ejection channel 51 returns to its original state. A push-shooting head chip can be realized by setting either the polarization direction of the actuator plate 41 or the direction of the electric field (layout of the common electrode and individual electrodes) inversely to that of a pull-shooting head chip.

[0148] In the above-described first embodiment, the various pads 91b, 92b are formed on the surface plate 43. However, the present invention is not limited to this configuration. The various pads may be formed on the intermediate plate .

[0149] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0150] 1: Printer (liquid jet recording device) 5: Inkjet head (liquid ejection head) 32: Head chip 41: Actuator plate 51: Discharge channel (channel) 52: Non-ejection channel (channel) 65: Common electrode (drive electrode) 65a: Narrow common electrode (1st electrode) 65b: Wide common electrode (second electrode) 66: Common wiring (drive wiring) 68: Individual electrode (driving electrode) 69: Individual wiring (drive wiring) 77:Narrow individual electrode (1st electrode) 78: Wide individual electrode (second electrode) 100: Mask pattern (mask for second electrode) 101: First recess (recess) 102: Second recess (recess) 105: Metal mask (mask for first electrode) 105a: Mask opening 200: Head chip 202: Actuator plate 211: Discharge channel 212: Non-ejection channel 231: Common electrode (drive electrode) 231a: Narrow common electrode (1st electrode) 231b: Wide common electrode (second electrode) 236: Individual electrode (driving electrode) 236a: Narrow individual electrode (1st electrode) 236b: Wide individual electrode (second electrode)

Claims

1. an actuator plate having a first opening on a first surface facing a first side in a thickness direction, and a second opening on a second surface facing a second side opposite to the first side in the thickness direction, the second opening having a length in a first direction intersecting the thickness direction shorter than that of the first opening, and a channel formed therein extending in the first direction intersecting the thickness direction; The actuator plate includes: a driving electrode formed on an inner surface of the channel; a driving wiring formed on the first surface of the actuator plate and connected to the driving electrode through an opening edge of the first opening; The driving electrode is a first electrode extending in the thickness direction from an edge of the first opening and having a dimension in the first direction smaller than that of the second opening; a second electrode extending in the thickness direction from the edge of the first opening while partially overlapping with the first electrode, the second electrode having a dimension in the thickness direction smaller than that of the first electrode and a dimension in the first direction larger than that of the first electrode.

2. The head chip according to claim 1 , wherein the first electrode is formed over the entire length of the channel in the thickness direction.

3. 3. The head chip according to claim 1, wherein the following formula is satisfied, where D1 is a dimension of the first electrode in the thickness direction, and D2 is a dimension of the second electrode in the thickness direction. (D1-D2)>D2

4. 3. The head chip according to claim 1, wherein the following formula is satisfied, where D1 is a dimension of the first electrode in the thickness direction, and D2 is a dimension of the second electrode in the thickness direction. (D1-D2)<D2

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

6. A liquid jet recording apparatus comprising the liquid jet head according to claim 5.

7. a first electrode forming process for forming a first electrode on an inner surface of the recess through the first opening, the first electrode extending in the thickness direction from an edge of the first opening, the first electrode being formed in the actuator plate, the first electrode having a dimension in a first direction intersecting the thickness direction that decreases toward a second side opposite the first side in the thickness direction; a second electrode forming step of forming a second electrode on an inner surface of the recess in the actuator plate, the second electrode extending from an edge of the first opening in the thickness direction through the first opening; a grinding step of grinding a second surface of the actuator plate facing a second side in the thickness direction, In the grinding step, the recess is opened on the second surface to form a channel penetrating the actuator plate in the thickness direction and having the first opening and a second opening having a length in the first direction shorter than that of the first opening; The first electrode has a dimension in the first direction smaller than that of the second opening, A method for manufacturing a head chip, wherein the second electrode, when partially overlapping the first electrode, has a dimension in the thickness direction smaller than that of the first electrode and a dimension in the first direction larger than that of the first electrode.

8. the first electrode forming step is performed by an oblique deposition method in which a conductor is deposited in a direction oblique to a normal direction of the first surface as viewed from the first direction, The method for manufacturing a head chip according to claim 7 , wherein in the first electrode forming step, deposition is performed on the inner surface of the recess so that at least a portion of the first electrode is larger than a dimension of the channel in the thickness direction.

9. the second electrode forming step is performed by an oblique deposition method in which a conductor is deposited in a direction oblique to a normal direction of the first surface as viewed from the first direction, The method for manufacturing a head chip according to claim 7 or 8, wherein in the second electrode forming step, deposition is performed on the inner surface of the recess so that the entire second electrode is smaller than the dimension of the channel in the thickness direction.

10. 9. The method for manufacturing a head chip according to claim 7, wherein the first electrode forming step is performed prior to the second electrode forming step.

11. the second electrode forming step is performed prior to the first electrode forming step, and the second electrode is formed on the first surface of the actuator plate using a second electrode mask having a mask opening corresponding to the first opening; 9. A method for manufacturing a head chip as described in claim 7 or claim 8, wherein in the first electrode formation process, the first electrode is formed while a mask for a first electrode, having a mask opening whose dimension in the first direction is smaller than that of the first opening, is set on a mask for a second electrode.

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