Liquid ejection head and liquid ejection apparatus

Abstract

The invention provides a liquid ejecting head and a liquid ejecting apparatus capable of improving mounting performance. A liquid ejection head according to one embodiment includes an actuator portion having a plurality of grooves forming a pressure chamber communicating with a nozzle, one end side in one direction is divided into a plurality of parts by the grooves, the other end side is provided with a connecting portion, and a plurality of pressure chambers are formed on the other end side of a side surface portion of the connecting portion. The mounting part is used for mounting the ACF.

Description

Technical Field

[0001] Embodiments of the present invention relate to a liquid ejecting head and a liquid ejecting device. Background Art

[0002] As a driving source for liquid ejection devices such as inkjet print heads, piezoelectric actuators using piezoelectric bodies such as PZT are used. For example, it is known to form a plurality of grooves in a piezoelectric body as an actuator component and to use the divided columnar piezoelectric elements as the structure of the actuator. For example, by forming a groove with a depth from one side to the middle of the piezoelectric body, an actuator component is formed in which one side is divided into multiple parts and the other side is connected. One external electrode of the actuator is set as an independent electrode to which a driving voltage is independently applied, and the other external electrode is set as a common electrode to which the same voltage (including 0) is always applied. Between multiple actuators, the independent electrodes are separated and the common electrodes are connected. For example, the independent electrodes are sometimes separated by cutting off the corner of one side of the piezoelectric body. Such an actuator is difficult to ensure installation due to the brittleness and fine shape of the piezoelectric element.

[0003] Patent Document 1: Japanese Patent No. 5668382 Summary of the Invention

[0004] The problem to be solved by the present invention is to provide a liquid ejection head and a liquid ejection device capable of improving mountability.

[0005] A liquid ejection head according to one embodiment includes an actuator portion having a plurality of grooves forming a pressure chamber connected to a nozzle, one end side in one direction being divided into a plurality by the grooves, and having a connecting portion on the other end side, and an installation portion for installing an ACF on a side portion of the connecting portion, closer to the other end side than the bottom surface of the groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a cross-sectional view showing the structure of an inkjet head according to the embodiment.

[0007] Figure 2 It is a cross-sectional view showing the structure of the inkjet head.

[0008] Figure 3 This is a side view of one side of the actuator portion of the inkjet head.

[0009] Figure 4 This is a side view of the other side of the actuator unit.

[0010] Figure 5 It is an explanatory diagram of the method for manufacturing the ink jet head according to this embodiment.

[0011] Figure 6It is an explanatory diagram showing a schematic configuration of an inkjet recording apparatus according to an embodiment.

[0012] Figure 7 It is an explanatory diagram of a method for manufacturing an inkjet head according to another embodiment.

[0013] Description of Reference Numerals

[0014] 1…Inkjet head; 10…Support base; 20…Actuator unit; 201…Laminated piezoelectric member; 21…Driven piezoelectric element; 22…Non-driven piezoelectric element; 23…Groove; 26…Connecting unit; 261…Mounting unit; 30…Vibrating plate; 31…Pressure chamber; 32…Common chamber; 33…Connecting unit; 40…Flow path member; 42…Partition wall; 50…Nozzle plate; 51…Nozzle; 60…Frame; 70…Drive circuit; 71…FPC; 72…Driver IC; 73…Printed wiring board; 731…Head control circuit; 100…Inkjet recording device; 111…Casing; 112…Media supply unit; 113…Image Forming portion; 114…medium discharge portion; 115…conveying device; 117…support portion; 118…conveying belt; 119…support plate; 120…belt roller; 121…guide plate pair; 122…conveying roller; 130…head unit; 132…ink tank; 133…connecting flow path; 134…supply pump; 116…control portion; 1161…control circuit; 211…piezoelectric layer; 212…dummy layer; 221…internal electrode; 222…internal electrode; 223…external electrode; 224…external electrode; 2230, 2240…electrode layer; 301…vibration region; 302…support region; 405…flow path substrate. DETAILED DESCRIPTION

[0015] Below, refer to Figures 1 to 6 An inkjet head 1 as a liquid ejecting head according to the embodiment and an inkjet recording apparatus 100 as a liquid ejecting device will be described. Figure 1 and Figure 2 It is a cross-sectional view showing a schematic configuration of the inkjet head 1 . Figure 3 is a side view of the independent electrode side, Figure 4 It is a side view of the common electrode side. Figure 5 is an explanatory diagram of the manufacturing process of the inkjet head 1, Figure 6 1 and 2 are explanatory diagrams showing a schematic configuration of the inkjet recording apparatus 100. Arrows X, Y, and Z in the figure indicate three mutually orthogonal directions. For the purpose of explanation in each figure, the configuration is appropriately enlarged, reduced, or omitted.

[0016] like Figure 1 and Figure 2As shown, the inkjet head 1 includes a support base 10 , a pair of actuator units 20 , a flow path member 40 , a nozzle plate 50 having a plurality of nozzles 51 , a frame unit 60 as a structural portion, and a drive circuit 70 .

[0017] As an example, the inkjet head 1 includes two actuator units 20, each having two nozzle rows, two pressure chamber rows, and two element rows. In the nozzle rows, multiple nozzles 51 are arranged in the row direction (X direction). In the pressure chamber rows, multiple pressure chambers 31 are arranged in the row direction. In the element rows, multiple piezoelectric elements 21 and 22 are arranged in the row direction. In this embodiment, the stacking direction of the multiple piezoelectric layers 211, the vibration direction of the piezoelectric elements 21, and the vibration direction of the vibration plate 30 are all along the Z direction.

[0018] The support base 10 supports the pair of actuator units 20. The support base 10 is, for example, plate-shaped. The support base 10 may also be a circuit board.

[0019] The actuator unit 20 is provided on one side of the support base 10. For example, two actuator units 20 are arranged side by side in the Y direction.

[0020] like Figures 1 to 4 As shown, the actuator unit 20 includes, for example, a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22, each composed of piezoelectric components, arranged alternately in a row direction, and a connecting portion 26 integrally connecting the plurality of piezoelectric elements 21 and 22 on the support base 10 side. The piezoelectric component is a stacked piezoelectric component 201 having a plurality of piezoelectric layers 211 and a plurality of internal electrodes 221 and 222 stacked on top of each other.

[0021] In the actuator unit 20 , a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22 are arranged in one direction at regular intervals.

[0022] As an example, a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22 are all configured as the columnar shape of the rectangular parallelepiped with the same shape. The actuator part 20 is divided into a plurality of driving piezoelectric elements 21 and a non-driving piezoelectric element 22 by forming a plurality of grooves 23 from one side. A plurality of driving piezoelectric elements 21 and a non-driving piezoelectric element 22 are arranged in the row direction with the same spacing by the grooves 23 of the same width in the arrangement direction. In addition, because the depth of the groove 23 of the actuator part 20 is set to be less than the total length of the size of the actuator part 20 in the Z direction, a connecting portion 26 that connects a plurality of elements 21, 22 into one is formed on the bottom surface 231 of the groove 23 by the support base 10 side.

[0023] The connecting portion 26 is a block-shaped component that is arranged on the base end side of the plurality of piezoelectric elements 21 and 22 and connects the plurality of piezoelectric elements 21 and 22. That is, the connecting portion 26 is formed into a plate-like shape that is connected to the entire length of the stacked piezoelectric component 201 in the long side direction along the X direction together with the layer. The thickness dimension of the connecting portion 26 along the Z direction is configured to be greater than 0.5 mm. An independent electrode constituting the external electrode 223 is formed on the side surface of one side of the end face of the connecting portion 26 in the Y direction, which is different from the Z direction. The independent electrode is, for example, a plurality of line patterns spaced apart from each other on one side surface of the connecting portion 26. In other words, on one side surface of the connecting portion 26, a plurality of line patterns spaced apart from each other, i.e., the external electrodes 223, and an electrode removal portion 225 obtained by removing the electrode layer 2230 using PEP or the like between the plurality of external electrodes 223 are alternately formed.

[0024] One side surface forms a mounting portion 261 for ACF or solder mounting. For example, on one side surface of the connecting portion 26, the FPC 71 is electrically and mechanically connected to the individual electrodes by solder or ACF mounting. For example, the side surface forming the mounting portion 261 and the opposite side surface form a plane perpendicular to the stacking direction.

[0025] Furthermore, a common electrode constituting the external electrode 224 is formed on the other side surface of the connection portion 26 in the Y direction. The common electrode includes an electrode layer 2240 formed on the entire surface of the other side surface of the connection portion 26 .

[0026] For example, the depth of the groove 23 is set to a depth that allows the connection portion 26 to ensure the size of the mounting portion 261. For example, when the groove 23 is formed from one side in the Z direction of the laminated piezoelectric member 201, by making the depth of the groove 23 shallower than the end portion on the support base 10 side, the size of the mounting portion 261 is ensured to be, for example, 0.5 mm or more as a size that allows for mounting.

[0027] For example, the plurality of driven piezoelectric elements 21 and the plurality of non-driven piezoelectric elements 22 are each configured in a rectangular shape with the short side direction along the column direction of the element column and the long side direction along the extending direction orthogonal to the column direction and the Z direction when viewed from above in the Z direction.

[0028] The driving piezoelectric elements 21 are arranged in the Z direction at positions facing each of the plurality of pressure chambers 31 formed in the flow path member 40. As an example, the center positions of the driving piezoelectric elements 21 in the row direction and the extension direction and the center positions of the pressure chambers 31 in the row direction and the extension direction are arranged side by side in the Z direction.

[0029] The non-driven piezoelectric elements 22 are arranged in the Z direction at positions opposite to the plurality of partition walls 42 formed in the flow path member 40. As an example, the center positions of the non-driven piezoelectric elements 22 in the row direction and the extension direction are aligned with the center positions of the partition walls 42 in the row direction and the extension direction in the Z direction.

[0030] For example, the actuator unit 20 forms a groove 23 by cutting a stacked piezoelectric member 201 that is previously bonded to the support base 10 from the end surface opposite to the support base 10, thereby forming a plurality of piezoelectric elements formed in a rectangular column shape at predetermined intervals. Then, an electrode layer is formed on the plurality of columnar elements formed to form a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22 that are alternately arranged. The plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22 are alternately arranged side by side in the column direction, separated by the groove 23.

[0031] For example, the laminated piezoelectric member 201 constituting the actuator portion 20 is formed by laminating and sintering sheet-shaped piezoelectric materials.

[0032] The piezoelectric components constituting the driven piezoelectric element 21 and the non-driven piezoelectric element 22 are, for example, stacked piezoelectric components 201. The driven piezoelectric element 21 and the non-driven piezoelectric element 22 each include a plurality of stacked piezoelectric layers 211 and internal electrodes 221 and 222 formed on the main surfaces of each piezoelectric layer 211. Furthermore, as an example, the driven piezoelectric element 21 and the non-driven piezoelectric element 22 each have the same stacked structure. Furthermore, the driven piezoelectric element 21 and the non-driven piezoelectric element 22 each include external electrodes 223 and 224 formed on their surfaces.

[0033] The piezoelectric layer 211 is formed into a thin plate from a piezoelectric ceramic material such as PZT (lead zirconate titanate) or lead-free KNN (potassium sodium niobate). The multiple piezoelectric layers 211 are stacked with their thickness aligned along the stacking direction and bonded to each other. For example, in this embodiment, the piezoelectric layers 211 are arranged with their thickness and stacking directions aligned with the vibration direction (Z direction).

[0034] The internal electrodes 221 and 222 are conductive films formed into a predetermined shape from a calcinable conductive material such as silver palladium. The internal electrodes 221 and 222 are formed in predetermined regions on the main surface of each piezoelectric layer 211. The internal electrodes 221 and 222 have different polarities. For example, one internal electrode 221 is formed in a region that reaches one end of the piezoelectric layer 211 but does not reach the other end of the piezoelectric layer 211 in the extension direction (Y direction), which is orthogonal to both the column direction (X direction) and the vibration direction (Z direction) of the arrangement of the multiple driven piezoelectric elements 21 and the multiple non-driven piezoelectric elements 22. Another internal electrode 222 is formed in a region that does not reach one end of the piezoelectric layer 211 but reaches the other end of the piezoelectric layer 211 in the extension direction. The internal electrodes 221 and 222 are connected to external electrodes 223 and 224 formed on the side surfaces of the piezoelectric elements 21 and 22, respectively.

[0035] Furthermore, the laminated piezoelectric member 201 constituting the driving piezoelectric element 21 and the non-driving piezoelectric element 22 further includes a dummy layer 212 on either or both of its ends on the support base 10 side and the nozzle plate 50 side. The dummy layer 212 is, for example, made of the same material as the piezoelectric layer 211, has an electrode on only one side, and does not deform when an electric field is not applied. For example, the dummy layer 212 does not function as a piezoelectric body, but instead serves as a base for securing the actuator unit 20 to the support base 10, or as a grinding allowance for improving precision during or after assembly.

[0036] External electrodes 223 and 224 are formed on the surfaces of the plurality of driven piezoelectric elements 21 and the plurality of non-driven piezoelectric elements 22, by converging the ends of the internal electrodes 221 and 222. For example, external electrode 223 is formed on one end surface in the direction in which the piezoelectric layer 211 extends. External electrode 224 is formed on the other end surface in the direction in which the piezoelectric layer 211 extends.

[0037] The external electrodes 223 and 224 are formed of Ni, Cr, Au, or the like by known methods such as electroplating or sputtering. The external electrodes 223 and 224 have different polarities. The external electrodes 223 and 224 are respectively arranged on different side surfaces of the plurality of driven piezoelectric elements 21 and the plurality of non-driven piezoelectric elements 22.

[0038] In this embodiment, as an example, the external electrode 223 is an independent electrode, and the external electrode 224 is a common electrode. The external electrodes 223, which serve as independent electrodes for the plurality of driven piezoelectric elements 21 and the plurality of non-driven piezoelectric elements 22, are independently arranged during the manufacturing process by patterning the electrode layer 2230 formed on one side of the stacked piezoelectric member 201. Specifically, one side of the external electrode 223 is divided by the groove 23, and the side surface of the connecting portion 26 on the support base 10 side of the electrode layer 2230 is divided by patterning, thereby forming a plurality of independent external electrodes 223 that are spaced apart from each other in the parallel direction.

[0039] The external electrodes 223 are connected to the drive circuit 70 via an FPC 71, which is an example of a flexible circuit board, at the mounting portion 261 on the side of the connecting portion 26. For example, each external electrode 223 is connected to the control unit 116, which is a drive unit, via the FPC 71 and the driver IC 72 of the drive circuit 70, so that the external electrodes 223 can be driven and controlled by the control circuit 1161. Alternatively, the external electrode 224 may be wrapped around the side surface of the external electrode 223 and connected to the drive circuit 70 via the FPC 71.

[0040] The external electrode 224 formed on the other end face of the actuator is configured so that the groove 23 is shallower than the end of the electrode layer 2240 on the support base 10 side. This allows the electrode layer 2240 to continue on the other side face of the piezoelectric member 201 in the region closer to the support base 10 than the bottom of the groove 23, forming a common electrode. For example, the external electrode 224 is grounded.

[0041] Dummy layer 212 is made of the same material as piezoelectric layer 211. Dummy layer 212 has an electrode only on one side and, because no electric field is applied, does not deform. In other words, dummy layer 212 does not function as a piezoelectric element, but rather serves as a base for mounting or as a grinding allowance for improving precision during or after assembly.

[0042] Furthermore, the vibration direction of each piezoelectric element 21 , 22 is along the stacking direction, and is displaced in the direction d33 by application of an electric field.

[0043] As an example, each piezoelectric element 21 , 22 has 3 or more layers and 50 or less layers, the thickness of each layer is set to 10 μm or more and 40 μm or less, and the product of the thickness and the total number of stacked layers is set to less than 1000 μm.

[0044] The piezoelectric element 21 is driven to vibrate by applying a voltage to the internal electrodes 221 and 222 via the external electrodes 223 and 224. In this embodiment, the piezoelectric element 21 vibrates longitudinally along the stacking direction of the piezoelectric layer 211. The longitudinal vibration referred to here refers to, for example, "vibration in the thickness direction defined by the piezoelectric constant d33." This longitudinal vibration of the piezoelectric element 21 displaces the vibration plate 30, thereby deforming the pressure chamber 31.

[0045] The flow path member 40 includes a vibration plate 30 disposed to face one side of the actuator portion 20 in the deformation direction, and a flow path substrate 405 stacked on one side of the vibration plate 30 .

[0046] The vibration plate 30 is provided between the flow path substrate 405 and the actuator unit 20 in the vibration direction. The vibration plate 30 and the flow path substrate 405 together constitute the flow path member 40. The vibration plate 30 extends in a direction intersecting the side surfaces forming the individual electrodes and the common electrode of the stacked piezoelectric member 201.

[0047] The vibration plate 30 extends along a surface perpendicular to the Z direction, which is the vibration direction, and is bonded to one side of the piezoelectric layer 211 of the plurality of piezoelectric elements 21 and 22 in the vibration direction, that is, to the surface on the nozzle plate 50 side. The vibration plate 30 is, for example, configured to be deformable. The vibration plate 30 is bonded to the driven piezoelectric elements 21 and the non-driven piezoelectric elements 22 of the actuator unit 20 and the frame unit 60. For example, the vibration plate 30 has a vibration region 301 that faces the piezoelectric elements 21 and 22, and a support region 302 that faces the frame unit 60.

[0048] The vibration region 301 is, for example, a flat plate configured such that its thickness direction corresponds to the vibration direction of the piezoelectric layer 211. The surface direction of the vibration plate 30 extends in the direction in which the multiple driven piezoelectric elements 21 and the multiple non-driven piezoelectric elements 22 are arranged. The vibration plate 30 is, for example, a metal plate. The vibration plate 30 has multiple vibration regions that are opposed to each pressure chamber 31 and can be independently displaced. The vibration plate 30 is formed by connecting the multiple vibration regions into an integral body.

[0049] As an example, the vibration plate 30 is made of nickel or SUS plate, and the thickness dimension along the vibration direction is about 5μm to 15μm. In addition, in the vibration area 301, in order to facilitate the displacement of multiple vibration parts, folds or steps can also be formed in parts adjacent to the vibration parts or between mutually adjacent vibration parts. The vibration area 301 is deformed by the displacement of the part arranged opposite to the driving piezoelectric element 21 due to the extension and compression of the driving piezoelectric element 21. For example, the vibration plate 30 requires a very thin and complex shape, so it can be formed by electroforming or the like. The vibration plate 30 can be joined to the upper end surface of the actuator part 20 by bonding or the like.

[0050] The support region 302 is a plate-shaped member disposed between the frame portion 60 and the fluid-channel substrate 405. The support region 302 includes a communication portion 33 having a through hole communicating with the common chamber 32.

[0051] For example, the communication portion 33 includes a filter member having a plurality of fine pores through which liquid can pass as through-holes.

[0052] The flow channel substrate 405 is disposed between the nozzle plate 50 and the vibration plate 30 in the vibration direction. The flow channel substrate 405 is bonded to one side of the vibration plate 30 in the vibration direction.

[0053] The flow path substrate 405 forms a predetermined ink flow path having a wall member such as a guide wall portion 41 or a partition wall portion 42 , and having a plurality of pressure chambers 31 separated from each other and a plurality of independent flow paths separated from each other and connecting the pressure chambers 31 with the common chamber 32 .

[0054] Within the fluid channel substrate 405, multiple pressure chambers 31 are separated by partition walls 42. Specifically, the partition walls 42 define both sides of the pressure chambers 31 in the parallel direction. Each pressure chamber 31 communicates with a nozzle 51 formed on a nozzle plate 50 disposed on one side. Furthermore, the side of the pressure chamber 31 opposite the nozzle plate 50 is blocked by the vibration plate 30.

[0055] The plurality of pressure chambers 31 are spaces formed on one side of the vibration region 301 of the vibration plate 30 and communicate with the common chamber 32 via independent flow paths or communication portions 33. The plurality of pressure chambers 31 communicate with the nozzles 51 formed on the nozzle plate 50. The side of the pressure chambers 31 opposite the nozzle plate 50 is blocked by the vibration plate 30.

[0056] The plurality of pressure chambers 31 hold liquid supplied from the common chamber 32 , and are deformed by the vibration of the vibration plate 30 forming a portion of the pressure chambers 31 , thereby ejecting the liquid from the nozzles 51 .

[0057] The partition wall 42 is a wall member that separates the multiple pressure chambers 31 arranged in the parallel direction and forms the pressure chambers 31 and the side portions. The partition wall 42 is arranged opposite the non-driven piezoelectric element 22 via the vibration plate 30 and is supported by the non-driven piezoelectric element 22. A plurality of partition walls 42 are provided at the same pitch as the arrangement of the multiple pressure chambers 31.

[0058] The nozzle plate 50 is a square plate with a thickness of about 10 to 100 μm and is made of metal such as SUS / Ni or resin such as polyimide. The nozzle plate 50 is arranged on one side of the flow channel substrate 405 to cover one opening of the pressure chamber 31 .

[0059] A plurality of nozzles 51 are arranged in a first direction that is the same as the direction in which the pressure chambers 31 are arranged, forming a nozzle row. For example, two rows of nozzles 51 are provided, with each nozzle 51 positioned at a position corresponding to the plurality of pressure chambers 31 arranged in the two rows. In this embodiment, the nozzles 51 are positioned at the ends of the pressure chambers 31 in the direction in which they extend.

[0060] The frame portion 60 is a structure that is joined to the vibration plate 30 together with the piezoelectric elements 21 and 22. The frame portion 60 is provided on the side of the vibration plate 30 of the piezoelectric elements 21 and 22 opposite to the flow path substrate 405, for example, in this embodiment, it is arranged adjacent to the actuator portion 20. The frame portion 60 constitutes the outer contour of the inkjet head 1. In addition, the frame portion 60 may also form a flow path for the liquid inside. In this embodiment, the frame portion 60 is joined to the other side of the vibration plate 30 and forms a common chamber 32 between the frame portion 60 and the vibration plate 30.

[0061] The common chamber 32 is formed inside the frame portion 60 and communicates with the pressure chamber 31 via the communication portion 33 provided on the vibration plate 30 and the independent flow path.

[0062] The drive circuit 70 includes an FPC 71 (Flexible printed circuit) connected to the actuator unit 20 via various wirings, a drive IC 72 mounted on the FPC 71 , and a printed wiring board 73 attached to the other end of the FPC 71 .

[0063] The driving circuit 70 applies a driving voltage to the external electrodes 223 and 224 via the driving IC 72 to drive the piezoelectric element 21 , thereby increasing or decreasing the volume of the pressure chamber 31 and ejecting liquid droplets from the nozzle 51 .

[0064] The FPC 71 is connected to the mounting portion 261 on the side surface of the connection portion 26 and is connected to the plurality of external electrodes 223 and 224 of the actuator portion 20. As the FPC 71, a COF (Chip on Film) on which a driver IC 72 is mounted is used as an electronic component.

[0065] The driver IC 72 is connected to the external electrodes 223 and 224 via the FPC 71. The driver IC 72 is an electronic component for ejection control.

[0066] The driver IC 72 generates control signals and drive signals for activating each piezoelectric element 21. Based on image signals input from the control unit 116 of the inkjet recording device 100 equipped with the inkjet head 1, the driver IC 72 generates control signals for selecting the timing for ejecting ink and controlling the piezoelectric elements 21 that eject ink. Furthermore, based on the control signals from the control unit 116, the driver IC 72 generates a voltage, or drive signal, to be applied to the piezoelectric elements 21. When the driver IC 72 applies a drive signal to the piezoelectric elements 21, the piezoelectric elements 21 are driven so as to displace the vibration plate 30 and change the volume of the pressure chamber 31. This causes pressure vibrations in the ink filling the pressure chamber 31. This pressure vibration causes ink to be ejected from the nozzle 51 connected to the pressure chamber 31. Furthermore, the inkjet head 1 can be configured to achieve grayscale representation by varying the amount of ink droplets that land per pixel. Furthermore, the inkjet head 1 can be configured to vary the amount of ink droplets that land per pixel by varying the number of times the ink is ejected. As described above, the driver IC 72 is an example of an application unit that applies a driving signal to the driven piezoelectric element 21 .

[0067] For example, the driver IC 72 includes a data buffer, a decoder, and a driver. The data buffer stores printing data for each driving piezoelectric element 21 in a time series. The decoder controls the driver for each driving piezoelectric element 21 based on the printing data stored in the data buffer. Based on the control of the decoder, the driver outputs a driving signal to activate each driving piezoelectric element 21. The driving signal is, for example, a voltage applied to each driving piezoelectric element 21.

[0068] The printed wiring board 73 is a PWA (Printing Wiring Assembly) on which various electronic components and connectors are mounted, and includes a head control circuit 731 . The printed wiring board 73 is connected to the control unit 116 of the inkjet recording apparatus 100 .

[0069] In the inkjet head 1 constructed as described above, an ink flow path having a plurality of pressure chambers 31 connected to the nozzle 51 and a common chamber 32 respectively connected to the plurality of pressure chambers 31 is formed by the nozzle plate 50, the frame portion 60, the flow path substrate 405, and the vibration plate 30. For example, the common chamber 32 is connected to the cartridge, and ink is supplied to each pressure chamber 31 through the common chamber 32. All the driving piezoelectric elements 21 are connected by wiring so that voltage can be applied. When the control unit 116 of the inkjet recording device 100 applies a driving voltage to the electrodes 221 and 222 through the driving IC 72, the driving piezoelectric element 21 of the driven object vibrates, for example, in the stacking direction, that is, in the thickness direction of each piezoelectric layer 211. That is, the driving piezoelectric element 21 vibrates longitudinally.

[0070] Specifically, the control unit 116 applies a driving voltage to the internal electrodes 221 and 222 of the driven piezoelectric element 21, selectively driving the driven piezoelectric element 21. The vibration plate 30 is then deformed by combining the tensile and compressive deformations of the driven piezoelectric element 21, changing the volume of the pressure chamber 31. This in turn guides liquid from the common chamber 32 and ejects it from the nozzle 51.

[0071] Reference Figure 5 An example of a method for manufacturing the inkjet head 1 according to this embodiment will be described. First, internal electrodes 221 and 222 are formed on a sheet of piezoelectric material by printing. Then, multiple piezoelectric layers 211 having internal electrodes 221 and 222 are stacked, sintered, and polarized to form the laminated piezoelectric member 201.

[0072] Then, the piezoelectric element 21 of the laminated piezoelectric member 201 having the internal electrodes 221 and 222 formed thereon is subjected to polarization treatment and then attached to the support base 10 using an adhesive or the like. For example, when two actuator units 20 are to be formed, the laminated piezoelectric member 201 formed integrally with the support base 10 may be joined and then divided into two by groove processing or the like, or two laminated piezoelectric members 201 constituting the two actuator units 20 may be prepared separately.

[0073] Then, with the laminated piezoelectric member 201 placed on the support base 10, the surface of the support base 10 and the surface of the laminated piezoelectric member 201 are processed using a tool such as a diamond cutter to shape the outer surface of the laminated piezoelectric member 201. This ensures the flatness of the upper surface of the actuator portion 20, to which the vibration plate 30 is bonded in a subsequent step.

[0074] Next, electrode layers 2230 and 2240, which will become external electrodes 223 and 224, are formed by printing on one and the other end surfaces of the laminated piezoelectric member 201. As an example, electrodes may be formed at once on the top of the actuator unit 20. In this case, the electrodes on the top of the actuator unit 20 are removed by grinding or the like, so that the external electrodes 223 and 224 are spaced apart from each other.

[0075] Next, the electrode layer 2230 formed on one side is patterned and individually divided. For example, the patterning method involves forming shallow grooves in the surface using PEP or laser processing, thereby partially removing the electrode layer 2230. Specifically, the electrode layer 2230 formed on the end surface of the stacked piezoelectric member 201 is divided into a plurality of columns in the X direction, alternating between forming a plurality of line patterns corresponding to the pressure chambers 31, namely, external electrodes 223, and electrode-removed portions 225 formed by partially removing the electrode layer 2230 between adjacent external electrodes 223.

[0076] Next, a tool such as a diamond cutter is moved in the Z direction to perform machining, thereby forming a plurality of grooves 23 in the actuator portion 20. At this time, the plurality of grooves 23 are simultaneously formed at a predetermined pitch, dividing the laminated piezoelectric member 201 into a plurality of columnar elements, thereby forming a plurality of piezoelectric elements 21 and 22 arranged at the same pitch. As a result, a plurality of driving piezoelectric elements 21 and non-driving piezoelectric elements 22 are formed, arranged at the same pitch.

[0077] Here, the groove 23 partially remains as a depth that does not reach the full length of the actuator unit 20 , thereby forming a connecting portion 26 in a region closer to the support base 10 than the bottom surface 231 of the groove 23 . This connecting portion 26 forms a mounting portion 261 .

[0078] After patterning and processing of the grooves 23, an external electrode 224 serving as a common electrode is formed on the other side of the connecting portion 26, continuous with the electrode layer 2240. Furthermore, an FPC 71, which serves as a control unit and on which electronic components such as a driver IC 72 are mounted, is connected to a mounting portion 261 on the side of the connecting portion 26 of the actuator unit 20, for example, by solder mounting or ACF mounting using anisotropic conductive film. Furthermore, a printed wiring board 73 having a head control circuit 731 is connected to the FPC 71.

[0079] Then, the vibration plate 30 , the flow path substrate 405 , and the nozzle plate 50 are stacked with bonding material interposed therebetween to position the actuator unit 20 . The frame 60 is disposed around the outer periphery of the actuator unit 20 , and these components are bonded together to complete the inkjet head 1 .

[0080] Below, refer to Figure 6 An example of an inkjet recording apparatus 100 including the inkjet head 1 will be described. The inkjet recording apparatus 100 includes a housing 111 , a medium supply unit 112 , an image forming unit 113 , a medium discharge unit 114 , a transport device 115 , and a control unit 116 .

[0081] The inkjet recording device 100 is a liquid ejecting device that ejects liquid such as ink while transporting, for example, paper P as an ejection object, i.e., a printing medium, along a predetermined transport path R from a medium supply unit 112 through an image forming unit 113 to a medium discharge unit 114, thereby performing image forming processing on the paper P.

[0082] The housing 111 forms the outer shell of the inkjet recording apparatus 100. The housing 111 is provided with a discharge port at a predetermined position thereof for discharging the paper P to the outside.

[0083] The medium supply unit 112 includes a plurality of paper feed cassettes and is configured to be able to stack and hold a plurality of sheets of paper P of various sizes.

[0084] The medium discharge unit 114 includes a paper discharge tray configured to hold the paper P discharged from the discharge port.

[0085] The image forming section 113 includes a support portion 117 that supports the paper P, and a plurality of head units 130 that are arranged to face each other above the support portion 117 .

[0086] The support portion 117 includes a conveyor belt 118 provided in an endless shape in a predetermined area where image formation is performed, a support plate 119 supporting the conveyor belt 118 from the rear side, and a plurality of belt rollers 120 provided on the rear side of the conveyor belt 118 .

[0087] The support portion 117 supports the paper P on a holding surface serving as the upper surface of the conveyor belt 118 during image formation, and conveys the conveyor belt 118 at a predetermined timing by the rotation of the belt roller 120 to convey the paper P downstream.

[0088] The head unit 130 includes a plurality of (four-color) inkjet heads 1 , ink tanks 132 as liquid tanks mounted on the respective inkjet heads 1 , connection channels 133 connecting the inkjet heads 1 and the ink tanks 132 , and a supply pump 134 .

[0089] In this embodiment, the inkjet heads 1 for four colors, cyan, magenta, yellow, and black, and the ink tanks 132 for storing the inks of the respective colors are provided. The ink tanks 132 are connected to the inkjet heads 1 via connection channels 133 .

[0090] Furthermore, a negative pressure control device, such as a pump (not shown), is connected to the ink tank 132. The negative pressure control device controls the negative pressure within the ink tank 132 in accordance with the hydraulic head value between the inkjet head 1 and the ink tank 132, thereby forming a meniscus of a predetermined shape into the ink supplied to each nozzle 51 of the inkjet head 1.

[0091] The supply pump 134 is a liquid delivery pump composed of, for example, a piezoelectric pump. The supply pump 134 is provided in the supply flow path. The supply pump 134 is connected to a control circuit 1161 of the control unit 116 via wiring and is controllable by the control unit 116. The supply pump 134 supplies liquid to the inkjet head 1.

[0092] The transport device 115 transports the paper P along a transport path R from the medium supply unit 112 through the image forming unit 113 to the medium discharge unit 114 . The transport device 115 includes a plurality of guide plate pairs 121 arranged along the transport path R and a plurality of transport rollers 122 .

[0093] Each of the plurality of guide plate pairs 121 includes a pair of plate members that are disposed opposite to each other with the paper P being transported interposed therebetween, and guides the paper P along the transport path R.

[0094] The transport roller 122 is driven and rotated under the control of the control unit 116 , thereby transporting the paper P downstream along the transport path R. In addition, sensors for detecting the transport status of the paper are arranged at various locations in the transport path R.

[0095] The control unit 116 includes a control circuit 1161 such as a CPU (Central Processing Unit) serving as a controller; a ROM (Read Only Memory) for storing various programs; a RAM (Random Access Memory) for temporarily storing various variable data and image data; and an interface unit for inputting and outputting data from and to the outside.

[0096] In the inkjet recording device 100 configured as described above, when, for example, a user detects a print instruction via an operation input unit in the interface, the control unit 116 drives the transport device 115 to transport the paper P and outputs a print signal to the head unit 130 at a predetermined timing, thereby driving the inkjet head 1. In the inkjet head 1, in the ejection operation, an image signal corresponding to image data is transmitted to the driver IC 72, which applies a drive voltage to the internal electrodes 221 and 222. This selectively drives the driving piezoelectric element 21 of the ejection target, causing it to vibrate longitudinally, for example, in the stacking direction. This changes the volume of the pressure chamber 31, causing ink to be ejected from the nozzle 51, thereby forming an image on the paper P held on the conveyor belt 118. Furthermore, in the liquid ejection operation, the control unit 116 drives the supply pump 134 to supply ink from the ink tank 132 to the common chamber 32 of the inkjet head 1.

[0097] Here, the driving action of driving the inkjet head 1 is described. The inkjet head 1 involved in this embodiment has a driving piezoelectric element 21 arranged opposite to the pressure chamber 31, and these driving piezoelectric elements 21 are connected by wiring so that voltage can be applied. The control unit 116 transmits a driving signal to the driving IC 72 through an image signal corresponding to the image data, applies a driving voltage to the internal electrodes 221 and 222 of the driving piezoelectric element 21 of the driven object, and selectively deforms the driving piezoelectric element 21 of the driven object. Then, by combining the deformation of the vibration plate 30 in the tensile direction and the deformation in the compression direction, the volume of the pressure chamber 31 is changed, thereby ejecting liquid.

[0098] For example, the control unit 116 alternately performs stretching and compression. In the inkjet head 1, when stretching is performed to increase the internal volume of the pressure chamber 31 of the object, the driving piezoelectric element 21 of the driving object is contracted, and the driving piezoelectric elements 21 outside the driving object are not deformed. In addition, when compressing is performed to reduce the internal volume of the pressure chamber 31 of the object in the inkjet head 1, the driving piezoelectric element 21 of the object is extended. In addition, the non-driving piezoelectric elements 22 are not deformed.

[0099] According to the inkjet head 1 and inkjet recording device 100 involved in the above-mentioned embodiment, a liquid ejection head and a liquid ejection device with high installability can be provided. That is, in the above-mentioned embodiment, the actuator part 20 is a structure in which one end side is divided and the other end side is connected. Since the mounting portion 261 is provided on the connecting portion 26, the connection strength can be ensured and the reliability can be improved. That is, the block-shaped connecting portion 26 without the groove 23 is a structure with high load resistance compared to the shape of multiple fine columnar elements. Therefore, the strength of the solder joint is high. In addition, other methods such as ACF joining can also be adopted to further improve reliability. In addition, by making the thickness dimension of the connecting portion 26 larger to be 0.5 mm or more, the installability can be further improved.

[0100] The present invention is not limited to the above-described embodiments as they are, and components can be modified and embodied in an implementation stage without departing from the spirit and scope of the invention.

[0101] In the above embodiment, as a process before forming the groove 23, an example of patterning by other means such as PEP or laser is shown, but it is not limited to this. Figure 7 As shown, after forming a plurality of grooves 23 on the entire surface of the stacked piezoelectric member 201 having the electrode layer 2230, the electrode layer 2230 of the connecting portion 26 may be patterned to separate the electrodes. Furthermore, in the case of the PEP method, if the method is performed after the grooves 23 are formed, the WET process may cause defects such as unevenness or residue due to the different flow patterns of the treatment liquid near the grooves 23 and other parts. Therefore, for the PEP method, it is more preferable to perform patterning before the grooves 23 are formed.

[0102] In addition, the specific materials and structures of the piezoelectric elements 21 and 22 in the above-mentioned embodiment are not limited to those described above, and can be changed as appropriate.

[0103] Furthermore, in the above embodiment, a plurality of piezoelectric layers 211 are stacked, and the piezoelectric element 21 is driven by longitudinal vibration (d33) in the stacking direction. However, the present invention is not limited to this. For example, the piezoelectric element 21 can also be driven by a single-layer piezoelectric member or by transverse vibration that displaces in the d31 direction.

[0104] The arrangement of the nozzles 51 or pressure chambers 31 is not limited to the above embodiment. For example, the nozzles 51 may be arranged in two or more rows. Furthermore, air chambers serving as dummy chambers may be formed between multiple pressure chambers 31. This is not limited to circulating inkjet heads; non-circulating inkjet heads are also possible. Furthermore, this is not limited to end-fire inkjet heads; side-fire inkjet heads are also possible.

[0105] In addition, an example is shown in which the piezoelectric elements 21 and 22 have dummy layers 212 at both ends in the stacking direction, but the present invention is not limited thereto. The dummy layer 212 may be provided on only one side of the piezoelectric elements 21 and 22, or the piezoelectric elements 21 and 22 may not have the dummy layer 212. Furthermore, the configuration and positional relationship of the various components including the flow path member 40, the nozzle plate 50, and the frame portion 60 are not limited to the examples described above and can be modified as appropriate.

[0106] Furthermore, in the above embodiment, an example is shown in which two actuator units 20 are arranged in parallel on the support base 10 , but the present invention is not limited thereto, and the number of actuator units 20 may be single.

[0107] Furthermore, the liquid to be discharged is not limited to ink for printing, and for example, a device that discharges a liquid containing conductive particles for forming a wiring pattern of a printed wiring board may also be used.

[0108] In addition, in the above embodiment, an example of the inkjet head 1 being used in a liquid ejecting device such as an inkjet recording device is shown, but it is not limited to this. For example, it can also be used for 3D printers, industrial manufacturing machinery, and medical purposes, and can achieve miniaturization, lightness, and low cost.

[0109] According to at least one of the embodiments described above, a liquid ejecting head and a liquid ejecting device capable of improving mountability can be provided.

[0110] In addition, although some embodiments of the present invention have been described, these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and their variations are included in the scope or spirit of the invention and are included in the invention described in the claims and their equivalents.

Claims

1. A liquid ejection head, characterized in that: An actuator portion is provided, wherein the actuator portion has a plurality of grooves forming a pressure chamber communicating with the nozzle, one end side in one direction is divided into a plurality of parts by the grooves, and the other end side has a connecting portion, A mounting portion for mounting the ACF is provided on the side surface of the connecting portion on the other end side of the bottom surface of the groove.

2. The liquid ejection head according to claim 1, wherein The dimension of the connecting portion in the one direction is 0.5 mm or more.

3. The liquid ejection head according to claim 1, wherein A plurality of independent electrodes spaced apart from each other are formed on one side of the connecting portion, A common electrode is formed on the other side surface of the connecting portion.

4. A liquid ejection head, characterized in that: An actuator portion is provided, wherein the actuator portion has a plurality of grooves forming a pressure chamber communicating with the nozzle, one end side in one direction is divided into a plurality of parts by the grooves, and the other end side has a connecting portion, The side surface of the connecting portion includes a mounting portion for solder mounting on the other end side of the bottom surface of the groove.

5. A liquid ejection device, characterized in that: A liquid ejection head according to any one of claims 1 to 4 is provided.

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