Liquid discharge head and liquid discharge apparatus

Abstract

A liquid ejecting head and a liquid ejecting apparatus capable of improving mountability are provided. A liquid ejecting head according to an embodiment includes a piezoelectric member, a substrate, and a separate electrode and a common electrode. The piezoelectric member is composed of a piezoelectric material and is formed with a plurality of grooves formed in one direction, and has a plurality of piezoelectric elements arranged across the grooves and a connection portion connecting the plurality of piezoelectric elements. The substrate is joined to the connection portion of the piezoelectric member. The separate electrode and the common electrode are formed on side surfaces on one side and the other side in the one direction of the piezoelectric member, respectively. The grooves are configured so that the depth of the end portion on the separate electrode side is deeper than the end portion on the common electrode side and the depth on the separate electrode side reaches the substrate.

Description

Technical Field

[0001] Embodiments of the present invention relate to a liquid ejector head and a liquid ejection device. Background Technology

[0002] As a driving source for liquid ejection devices such as inkjet printheads, piezoelectric actuators using piezoelectric materials such as PZT are employed. For example, a known configuration is a piezoelectric element, which serves as the actuator component, has multiple grooves formed on it and is divided into columnar shapes. One external electrode of the actuator is designated as a separate electrode to which a driving voltage is applied individually, while the other external electrode is designated as a common electrode to which the same voltage (including 0) is applied continuously. Among multiple actuators, the individual electrodes are separated, and the common electrode is connected. Sometimes, for example, the individual electrodes are separated by cutting off a corner of one side of the piezoelectric element. Because the piezoelectric element in such actuators is brittle and has a fine shape, it is difficult to ensure installation stability. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a liquid nozzle and liquid dispensing device that can improve installability.

[0004] One embodiment of the liquid ejector head includes a piezoelectric component, a substrate, individual electrodes, and a common electrode. The piezoelectric component is made of a piezoelectric material and has multiple grooves formed in one direction, and has multiple piezoelectric elements disposed across the grooves and connecting portions connecting the multiple piezoelectric elements. The substrate is joined to the connecting portions of the piezoelectric component. Individual electrodes and a common electrode are respectively formed on one side and the other side of the piezoelectric component in the one direction. The grooves are configured such that the depth of the end on the individual electrode side is deeper than the depth of the end on the common electrode side, and the depth of the individual electrode side reaches the substrate.

[0005] One embodiment of the liquid ejection device includes the liquid ejection head described above. Attached Figure Description

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

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

[0008] Figure 3 This is a three-dimensional view showing the structure of a portion of the inkjet head.

[0009] Figure 4 This is a side view of one side of the actuator section of the inkjet head.

[0010] Figure 5 This is a side view of the actuator section from the other side.

[0011] Figure 6 This is an explanatory diagram showing the manufacturing method of the inkjet head.

[0012] Figure 7 This is an explanatory diagram showing the manufacturing method of the inkjet head.

[0013] Figure 8 This is an explanatory diagram showing a simplified configuration of the inkjet recording apparatus according to the embodiment.

[0014] Figure 9 This is an explanatory diagram showing the manufacturing method of the inkjet head.

[0015] Figure 10 This is an explanatory diagram showing the manufacturing method of the inkjet head.

[0016] Explanation of reference numerals in the attached figures

[0017] 1…Inkjet head, 10…Substrate, 20…Actuator section, 201…Layered piezoelectric components, 21…Drive piezoelectric element, 22…Non-drive piezoelectric element, 23…Gate, 26…Connection section, 30…Vibrating plate, 31…Pressure chamber, 32…Common chamber, 33…Connection section, 40…Flow path component, 42…Partition wall section, 50…Nozzle plate, 51…Nozzle, 60…Frame section, 70…Drive circuit, 71…FPC, 72…Driver IC, 73…Printed wiring board, 731…Head control circuit, 100…Inkjet recording device, 111…Frame, 112…Media supply section, 113… Image forming unit, 114…media discharge unit, 115…conveying device, 117…support unit, 118…conveyor 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 unit, 1161…control circuit, 211…piezoelectric layer, 212…virtual layer, 221…internal electrode, 222…internal electrode, 223…external electrode, 224…external electrode, 301…vibration area, 302…support area, 405…flow path substrate. Detailed Implementation

[0018] Below, refer to Figures 1 to 8 The inkjet head 1, which is a liquid ejection head, and the inkjet recording device 100, which is a liquid ejection device, according to the embodiment, will be described. Figure 1 and Figure 2 This is a cross-sectional view showing the simplified structure of the inkjet head 1. Figure 3 This is a three-dimensional view showing the structure of a portion of the inkjet head. Figure 4 This is a side view of the individual electrode side. Figure 5 This is a side view of the common electrode side. Figure 6 and Figure 7 This is an explanatory diagram showing the manufacturing method of the inkjet head. Figure 8 This is an explanatory diagram showing a simplified configuration of the inkjet recording device 100. The arrows X, Y, and Z in the diagram represent three mutually orthogonal directions. In each diagram, for ease of explanation, the configuration has been appropriately enlarged, reduced, or omitted.

[0019] like Figure 1 and Figure 2 As shown, the inkjet head 1 includes a substrate 10, a pair of actuator sections 20, a flow path component 40, a nozzle plate 50 having a plurality of nozzles 51, a frame section 60 as a structural section, and a drive circuit 70.

[0020] As an example, the inkjet head 1 includes two actuator sections 20, each having two rows of nozzles 51 arranged in the column direction (X direction), a row of pressure chambers 31 arranged in the column direction, and a row of piezoelectric elements 21, 22 arranged in the column direction. In this embodiment, an example is shown where the stacking direction of the piezoelectric layers 211, the vibration direction of the piezoelectric elements 21, and the vibration direction of the vibrating plate 30 are all along the Z direction.

[0021] The substrate 10 is a circuit board that supports a pair of actuator sections 20. The substrate 10 is configured as a plate, for example, and has mounting surfaces along the extension direction and the arrangement direction. Electrode layers 11 and 12 are formed on the mounting surfaces of the substrate 10 on which the actuator sections 20 are mounted. For example, on the mounting surfaces of the substrate 10, an electrode layer 11 constituting a separate electrode is formed in the region opposite to the side of the pair of actuator sections 20, i.e., the outer side, and an electrode layer 12 constituting a common electrode is formed in the region on the inner side of the pair of actuator sections 20.

[0022] For example, on the mounting surface of the substrate 10, a plurality of grooves 101 are formed along the extension direction in the regions on the outer sides at both ends of the extension direction. The plurality of grooves 101 are arranged in the arrangement direction and are formed continuously with the grooves 23 of the actuator section 20, which will be described later. On the mounting surface of the substrate 10, the electrode layer 11 is separated by the plurality of grooves 101, thereby forming a predetermined wiring pattern (wiring section) having a plurality of individual wirings 102. For example, the individual wirings 102 are continuous with the external electrodes 223 formed on the side of the actuator section 20, constituting individual electrodes.

[0023] Furthermore, on the mounting surface of the substrate 10, the electrode layer 12 formed in the region inside between the pair of actuator sections 20 has a common wiring 103. The common wiring 103 is continuous with the external electrode 224 of the actuator section 20, forming a common electrode.

[0024] The actuator section 20 is engaged with a mounting surface that is one side of the substrate 10. For example, two actuator sections 20 are arranged in the Y direction.

[0025] like Figures 1 to 5 As shown, the actuator section 20 is, for example, composed of a piezoelectric component, and includes a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22 arranged alternately along the column direction as actuators, and a connecting portion 26 integrally connecting these plurality of piezoelectric elements 21, 22 on the substrate 10 side. The piezoelectric component is a stacked piezoelectric component 201 formed by stacking a plurality of piezoelectric body layers 211 and a plurality of internal electrodes 221, 222.

[0026] In the actuator section 20, a plurality of driven piezoelectric elements 21 and a plurality of non-driven piezoelectric elements 22 are arranged in one direction at fixed intervals.

[0027] As an example, the multiple driven piezoelectric elements 21 and the multiple non-driven piezoelectric elements 22 are all configured as cuboid columns with the same shape. The actuator section 20 is divided into multiple parts by multiple slots 23, and all the multiple driven piezoelectric elements 21 and non-driven piezoelectric elements 22 are arranged in the column direction with the same spacing due to the slots 23 of the same width.

[0028] The groove 23 is configured such that the depth of the end on the individual electrode side is deeper than the depth of the end on the common electrode side, and the depth of the individual electrode side reaches the substrate 10. For example, when the groove 23 is formed from one side of the stacked piezoelectric member 201 in the Z direction, the depth of the groove 23 is set such that one side in the extension direction is deeper than the other side. That is, by forming a groove 23 that is deeper than the end of the external electrode 223 formed on the substrate 10 side, the external electrode 223 on one end side is divided into multiple parts, forming multiple individual electrodes. Furthermore, on the side portion of the stacked piezoelectric member 201 on the other side, by forming a groove 23 that is shallower than the end of the external electrode 224 on the substrate 10 side, the external electrode 224 is connected to the substrate 10 side.

[0029] Furthermore, the groove 23 is configured such that its depth reaches the substrate 10 in a predetermined area on at least one side. In other words, the groove 23 formed on the pair of actuator portions 20 is continuous with the plurality of grooves 101 formed on the surface portion of the substrate 10. For example, the groove 23 is formed simultaneously on the actuator portion 20 and the substrate 10 by simultaneously machining the laminated piezoelectric component 201 and the substrate 10 using a common tool. In addition, the groove 23 is shallower in the region on the common electrode side, leaving a portion of the laminated piezoelectric component 201 remaining. Therefore, no groove is formed in the region on the common electrode side of the substrate 10, and the electrode layer 12 forms the common wiring 103 in an integral and continuous state.

[0030] For example, multiple driven piezoelectric elements 21 and multiple non-driven piezoelectric elements 22 are respectively configured as rectangles in which, when viewed from above in the Z direction, the short side direction is along the column direction of the element column and the long side direction is along the extension direction orthogonal to the column direction and the Z direction.

[0031] The drive piezoelectric elements 21 are arranged in the Z direction at positions opposite to the plurality of pressure chambers 31 formed in the flow path component 40. As an example, the center positions of the drive piezoelectric elements 21 in the column direction and the center positions of the pressure chambers 31 in the column direction and the extension direction are arranged in the Z direction.

[0032] The non-driven piezoelectric elements 22 are arranged in the Z direction at positions opposite to the plurality of partition walls 42 formed on the flow path member 40. As an example, the center positions of the non-driven piezoelectric elements 22 in the column direction and the center positions of the partition walls 42 in the column direction and the extension direction are arranged in the Z direction.

[0033] For example, the actuator section 20 forms a groove 23 by cutting a layered piezoelectric component 201 pre-bonded to the substrate 10 from the end face opposite to the substrate 10 side, thereby forming a plurality of piezoelectric elements at predetermined intervals. These plurality of piezoelectric elements are formed into rectangular columnar shapes. In addition, electrodes and the like are provided on the formed plurality of columnar elements to form a plurality of driven piezoelectric elements 21 and a plurality of non-driven piezoelectric elements 22 arranged alternately. The plurality of driven piezoelectric elements 21 and the plurality of non-driven piezoelectric elements 22 are arranged alternately in the column direction, separated by the groove 23.

[0034] For example, the stacked piezoelectric component 201 constituting the actuator section 20 is formed by stacking and sintering sheet-like piezoelectric materials.

[0035] 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 have multiple stacked piezoelectric layers 211 and internal electrodes 221 and 222 formed on the main surface of each piezoelectric layer 211. It should be noted that, as an example, the driven piezoelectric element 21 and the non-driven piezoelectric element 22 have the same stacked structure. Furthermore, the driven piezoelectric element 21 and the non-driven piezoelectric element 22 each have external electrodes 223 and 224 formed on their surfaces.

[0036] The piezoelectric layer 211 is formed into a thin plate shape, for example, from a piezoelectric ceramic material such as PZT (lead zirconate titanate) or lead-free KNN (sodium potassium niobate). Multiple piezoelectric layers 211 are stacked with their thickness direction along the stacking direction and bonded together. For example, in this embodiment, the thickness direction and stacking direction of the piezoelectric layers 211 are arranged along the vibration direction (Z direction).

[0037] Internal electrodes 221 and 222 are conductive films formed in a predetermined shape from calcinable conductive materials such as silver and palladium. Internal electrodes 221 and 222 are formed in predetermined regions on the main surface of each piezoelectric layer 211. Internal electrodes 221 and 222 are different from each other. For example, one internal electrode 221 is formed in a region that reaches one end of piezoelectric layer 211 but not the other end in a direction orthogonal to both the column direction (X direction) and the vibration direction (Z direction) of the arrangement of the plurality of driven piezoelectric elements 21 and the plurality of non-driven piezoelectric elements 22, i.e., the extension direction (Y direction). The other internal electrode 222 is formed in a region that does not reach one end of piezoelectric layer 211 in the extension direction but reaches the other end. Internal electrodes 221 and 222 are respectively connected to external electrodes 223 and 224 formed on the sides of piezoelectric elements 21 and 22.

[0038] Furthermore, the stacked piezoelectric components 201 constituting the driving piezoelectric element 21 and the non-driving piezoelectric element 22 also have a virtual layer 212 at either or both of their ends on the substrate 10 side and the nozzle plate 50 side. The virtual layer 212 is made of the same material as the piezoelectric layer 211, for example, and has an electrode on only one side. It is not subjected to an electric field and therefore does not deform. For example, the virtual layer 212 does not function as a piezoelectric element, but instead serves as a substrate for fixing the actuator part 20 to the substrate 10, or as an abrasive for grinding to ensure accuracy during and after assembly.

[0039] External electrodes 223 and 224 are formed on the surfaces of multiple driven piezoelectric elements 21 and multiple non-driven piezoelectric elements 22, and are formed by converging the ends of internal electrodes 221 and 222. For example, external electrode 223 is formed on one end face of the piezoelectric layer 211 in the extension direction.

[0040] An external electrode 224 is formed on the other end face of the piezoelectric layer 211 in the extending direction. Furthermore, the external electrode 224 is continuous with a common wiring 103 formed by the electrode layer 12 on the substrate 10 of the piezoelectric layer 211.

[0041] External electrodes 223 and 224 are formed into films from Ni, Cr, Au, etc., using known methods such as electroplating and sputtering. External electrodes 223 and 224 are different electrodes. External electrodes 223 and 224 are respectively disposed on different side portions of the plurality of driven piezoelectric elements 21 and the plurality of non-driven piezoelectric elements 22.

[0042] In this embodiment, as an example, external electrode 223 is a separate electrode, and external electrode 224 is a shared electrode. Figure 6 and Figure 7As shown, in the external electrode 223, which serves as the individual electrode of a plurality of driven piezoelectric elements 21 and a plurality of non-driven piezoelectric elements 22, during the manufacturing process, the electrode layer 2230 formed on one side of the stacked piezoelectric component 201 is divided by a groove 23 and arranged independently of each other. That is, the external electrode 223 on one side is configured such that the groove 23 is deeper than the end of the electrode layer 2230 on the substrate 10 side, so that the electrode layers 2230 are separated from each other and independent in the arrangement direction, thus constituting the external electrode 223 as a plurality of individual electrodes.

[0043] External electrodes 223 are connected to the drive circuit 70, for example, via individual wiring 102 on the substrate 10 and via an FPC 71, which is an example of a wiring substrate. For example, each external electrode 223 is configured to be connected to a control unit 116, which is a drive unit, via the drive IC 72 of the drive circuit 70 through the FPC 71, and can be driven and controlled by the control circuit 1161. It should be noted that external electrodes 224 may also be disposed on the side of the external electrode 223 and connected to the drive circuit 70 via the FPC 71.

[0044] The external electrode 224 formed on the other side end face of the actuator is configured such that the groove 23 is shallower than the end of the electrode layer on the substrate 10 side, so that the electrode layer 2240 is continuous in the region closer to the substrate 10 side than the bottom of the groove 23, forming a common electrode. The external electrodes 224 are connected to each other on the other side of the stacked piezoelectric component 201 and connected to the common wiring 103 on the substrate 10, for example, grounding.

[0045] The virtual layer 212 and the piezoelectric layer 211 are made of the same material. The virtual layer 212 has electrodes on only one side and is not subjected to an electric field, therefore it will not deform. That is, the virtual layer 212 does not function as a piezoelectric element, but serves as a substrate for fixing or as an abrasive for grinding to ensure accuracy during and after assembly.

[0046] In addition, the vibration direction of each piezoelectric element 21 and 22 is along the stacking direction, and is displaced in the d33 direction by applying an electric field.

[0047] As an example, each piezoelectric element 21 and 22 has 3 or more layers and less than 50 layers, the thickness of each layer is set to be more than 10μm and less than 40μm, and the product of the thickness and the total number of layers is set to be less than 1000μm.

[0048] Regarding the driving piezoelectric element 21, vibration is achieved by applying voltage to the internal electrodes 221 and 222 via external electrodes 223 and 224. In this embodiment, the driving piezoelectric element 21 vibrates longitudinally along the stacking direction of the piezoelectric layer 211. This longitudinal vibration is, for example, "vibration in the thickness direction as defined by the piezoelectric constant d33". The driving piezoelectric element 21 displaces the vibrating plate 30 through longitudinal vibration, thereby deforming the pressure chamber 31.

[0049] The flow path component 40 includes a vibrating plate 30 disposed opposite to one side of the actuator section 20 in the deformation direction, and a flow path substrate 405 stacked on one side of the vibrating plate 30.

[0050] The vibrating plate 30 is disposed between the flow path substrate 405 and the actuator section 20 in the vibration direction. The vibrating plate 30 and the flow path substrate 405 together constitute the flow path component 40. The vibrating plate 30 extends in a direction that intersects with the side of the stacked piezoelectric component 201 where individual electrodes and shared electrodes are formed.

[0051] The vibrating plate 30 extends along a surface orthogonal to the Z-direction, which is the vibration direction, and engages with the surface of the piezoelectric layer 211 of the plurality of piezoelectric elements 21, 22 on one side of the vibration direction, namely the nozzle plate 50 side. The vibrating plate 30 is configured to be deformable, for example. The vibrating plate 30 engages with the driving piezoelectric element 21 and the non-driving piezoelectric element 22 of the actuator section 20, as well as the frame section 60. For example, the vibrating plate 30 has a vibration region 301 opposite to the piezoelectric elements 21, 22, and a support region 302 opposite to the frame section 60.

[0052] The vibration region 301 is, for example, a flat plate configured with its thickness direction aligned with the vibration direction of the piezoelectric layer 211. The surface direction of the vibration plate 30 extends in the arrangement direction of the plurality of driven piezoelectric elements 21 and the plurality of non-driven piezoelectric elements 22. The vibration plate 30 is, for example, a metal plate. The vibration plate 30 has a plurality of vibration portions opposite to each pressure chamber 31 and capable of individual displacement. The vibration plate 30 is formed by connecting the plurality of vibration portions together.

[0053] As an example, the vibrating plate 30 is made of nickel and SUS plate, with a thickness of approximately 5 μm to 15 μm along the vibration direction. It should be noted that, in the vibration region 301, to facilitate the displacement of multiple vibration points, creases or height differences may be formed at locations adjacent to or between adjacent vibration points. By driving the elongation and compression of the piezoelectric element 21, the portion opposite to the driving piezoelectric element 21 is displaced, thereby deforming the vibration region 301. For example, the vibrating plate 30 needs to have a very thin and complex shape; therefore, it is formed by electroforming or the like. The vibrating plate 30 is bonded to the upper surface of the actuator section 20 by adhesive or the like.

[0054] The support region 302 is a plate-shaped component disposed between the frame portion 60 and the flow path substrate 405. The support region 302 has a connecting portion 33, which has a through hole communicating with the common chamber 32.

[0055] For example, the connecting part 33 has a filter element that has multiple fine holes through which liquid can pass as through holes.

[0056] The flow path substrate 405 is disposed between the nozzle plate 50 and the vibrating plate 30 in the vibration direction. The flow path substrate 405 is joined to one side of the vibrating plate 30 in the vibration direction.

[0057] The flow path substrate 405 has wall components such as guide wall portion 41 and partition wall portion 42, forming a predetermined ink flow path having multiple pressure chambers 31 separated from each other and multiple individual flow paths connecting the separated pressure chambers 31 and the common chamber 32.

[0058] Within the flow path substrate 405, multiple pressure chambers 31 are separated by partition walls 42. That is, the two sides of the arrangement direction of the pressure chambers 31 are formed by partition walls 42. Each pressure chamber 31 communicates with a nozzle 51 formed on a nozzle plate 50 disposed on one side. Furthermore, in the pressure chamber 31, the opposite side of the nozzle plate 50 is blocked by a vibrating plate 30.

[0059] Multiple pressure chambers 31 are spaces formed on one side of the vibration region 301 of the vibrating plate 30, and are connected to a common chamber 32 via individual flow paths and connecting portions 33. The multiple pressure chambers 31 are connected to nozzles 51 formed on the nozzle plate 50. Furthermore, in the pressure chambers 31, the opposite side of the nozzle plate 50 is blocked by the vibrating plate 30.

[0060] Multiple pressure chambers 31 contain liquid supplied from a common chamber 32, which is deformed by the vibration of a vibrating plate 30 that forms part of the pressure chamber 31, thereby ejecting the liquid from the nozzle 51.

[0061] The partition wall 42 is a wall component that separates the multiple pressure chambers 31 arranged in the arrangement direction and forms both sides of the pressure chambers 31. The partition wall 42 is disposed opposite to the non-driven piezoelectric element 22 across the vibrating plate 30 and is supported by the non-driven piezoelectric element 22. Multiple partition walls 42 are provided at a spacing that is the same as the spacing between the multiple pressure chambers 31.

[0062] The nozzle plate 50 is configured as a square plate with a thickness of about 10 μm to 100 μm, for example, made of metals such as SUS·Ni and resin materials such as polyimide. The nozzle plate 50 is disposed on one side of the flow path substrate 405 such that it covers the opening on one side of the pressure chamber 31.

[0063] Multiple nozzles 51 are arranged in a first direction, which is the same as the arrangement direction of the pressure chambers 31, to form a nozzle array. For example, two rows of nozzles 51 are provided, with each nozzle 51 positioned at a position corresponding to one of the multiple pressure chambers 31 arranged in two rows. In this embodiment, the nozzles 51 are respectively positioned at the ends of the pressure chambers 31 in the extending direction.

[0064] The frame portion 60 is a structure that is joined to the vibrating plate 30 together with the piezoelectric elements 21 and 22. The frame portion 60 is disposed on the side of the vibrating plate 30 opposite to the flow path substrate 405 of the piezoelectric elements 21 and 22, for example, in this embodiment, it is arranged adjacent to the actuator portion 20. The frame portion 60 forms the outer contour of the inkjet head 1. Furthermore, the frame portion 60 may also form a liquid flow path internally. In this embodiment, the frame portion 60 is joined to the other side of the vibrating plate 30 and forms a common chamber 32 with the vibrating plate 30.

[0065] The common chamber 32 is formed inside the frame portion 60 and is connected to the pressure chamber 31 through the connecting portion 33 provided in the vibrating plate 30 and a separate flow path.

[0066] The driving circuit 70 includes an FPC71 (Flexible printed circuits) connected to the actuator section 20 via individual wiring 102 and common wiring 103 on the mounting surface of the substrate 10, a driving IC72 mounted on the FPC71, and a printed wiring substrate 73 mounted on the other end of the FPC71.

[0067] The drive circuit 70 applies a drive voltage to the external electrodes 223 and 224 through the drive IC 72, thereby driving the drive piezoelectric element 21, causing the volume of the pressure chamber 31 to increase or decrease, and ejecting droplets from the nozzle 51.

[0068] The FPC71 is connected to the mounting surface of the substrate 10 and is connected to multiple external electrodes 223 and 224 of the actuator section 20 via individual wiring 102 and common wiring 103. As the FPC71, a COF (chip-on-film) is used, which is mounted as an electronic component to drive the IC72.

[0069] The driver IC 72 is connected to external electrodes 223 and 224 via FPC 71. The driver IC 72 is an electronic component used for ejection control.

[0070] The driver IC 72 generates control signals and drive signals to operate each drive piezoelectric element 21. Based on the image signal input from the control unit 116 of the inkjet recording apparatus 100 equipped with the inkjet head 1, the driver IC 72 generates control signals for controlling the timing of ink ejection and the drive piezoelectric elements 21 that eject ink. Furthermore, the driver IC 72 generates a voltage, i.e., a drive signal, applied to the drive piezoelectric element 21 based on the control signal from the control unit 116. When the driver IC 72 applies a drive signal to the drive piezoelectric element 21, the drive piezoelectric element 21 is driven, causing the vibrating plate 30 to displace and changing the volume of the pressure chamber 31. This causes pressure vibration in the ink filling the pressure chamber 31. Through this pressure vibration, ink is ejected from the nozzle 51, which communicates with the pressure chamber 31. It should be noted that the inkjet head 1 can also achieve grayscale representation by changing the amount of ink droplets falling on a pixel. Furthermore, the inkjet head 1 can also change the amount of ink droplets falling on a pixel by changing the number of ink ejections. Thus, the driver IC72 is an example of an application unit that applies a drive signal to the drive piezoelectric element 21.

[0071] For example, the driver IC 72 includes a data buffer, a decoder, and a driver. The data buffer stores the printed data for each driven piezoelectric element 21 in a timing sequence. The decoder controls the driver for each driven piezoelectric element 21 based on the printed data stored in the data buffer. Based on the decoder's control, the driver outputs a drive signal that causes each driven piezoelectric element 21 to operate. The drive signal is, for example, a voltage applied to each driven piezoelectric element 21.

[0072] The printed wiring board 73 is a PWA (Printing Wiring Assembly) equipped with various electronic components and connectors, and has a head control circuit 731. The printed wiring board 73 is connected to the control unit 116 of the inkjet recording device 100.

[0073] In the inkjet head 1 configured as described above, an ink flow path is formed by a nozzle plate 50, a frame portion 60, a flow path substrate 405, and a vibrating plate 30. This ink flow path has multiple pressure chambers 31 communicating with the nozzles 51, and a common chamber 32 communicating with each of the multiple pressure chambers 31. For example, the common chamber 32 communicates with the ink 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 in a voltage-applyable manner. In the inkjet head 1, for example, if the control unit 116 of the inkjet recording device 100 applies a driving voltage to the electrodes 221 and 222 via 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.

[0074] Specifically, the control unit 116 applies a driving voltage to the internal electrodes 221 and 222 of the driving piezoelectric element 21 of the driven object, selectively driving the driving piezoelectric element 21 of the driven object. In addition, the deformation in the tensile direction and the deformation in the compression direction caused by the driving piezoelectric element 21 of the driven object deform the vibrating plate 30, change the volume of the pressure chamber 31, thereby guiding the liquid from the common chamber 32 and ejecting it from the nozzle 51.

[0075] 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-shaped piezoelectric material by printing. Then, multiple piezoelectric layers 211 having internal electrodes 221 and 222 are stacked, and calcination and polarization treatments are performed to form a stacked piezoelectric component 201.

[0076] In addition, such as Figure 6 As shown, the piezoelectric element 21, which has internal electrodes 221 and 222 pre-formed in the stacked piezoelectric component 201, undergoes polarization treatment and is then bonded to the substrate 10 using an adhesive or the like. For example, in the case of constructing two actuator sections 20, the integrally constructed stacked piezoelectric component 201 can be joined to the substrate 10 and then divided into two by groove processing or the like, or two stacked piezoelectric components 201 constituting the two actuator sections 20 can be prepared separately.

[0077] In addition, such as Figure 7 As shown, with the stacked piezoelectric component 201 disposed on the substrate 10, the surfaces of the substrate 10 and the stacked piezoelectric component 201 are surface-machined (Act 11) using a tool 282 such as a diamond cutter, thereby forming the mounting surface and the outer surface of the stacked piezoelectric component 201 (Act 12). This ensures the flatness of the upper surface of the actuator component 20, which is then joined to the vibrating plate 30 in subsequent processes.

[0078] Next, electrode layers 2230 and 2240, serving as external electrodes 223 and 224, are formed on the end faces of one and the other of the stacked piezoelectric components 201 by printing, and electrode layers 11 and 12 (Act 13) are formed on the mounting surface of the substrate 10. As an example, electrodes may also be temporarily formed on the top of the actuator component 20. In this case, the electrodes on the top of the actuator component 20 are removed by grinding or the like, thereby separating the external electrodes 223 and 224 from each other.

[0079] Next, by moving a tool 282, such as a diamond cutter, in the Z direction, machining is performed, thereby forming a plurality of grooves 23 (Act 14) in the actuator section 20. As an example, in this embodiment, such as... Figure 7As shown, a tool 282, which bends the cutting edge 2821 so that it gradually becomes shallower from one side of the extending direction to the other, is used to form the groove 23, thereby forming the bottom surface 231 of the groove 23 into a curved shape that gradually becomes shallower from one side of the extending direction to the other. Here, the groove 23 is formed to reach the full length of the electrode layer 2230 in the depth direction at one end, thereby achieving the desired depth. Figure 4 As shown, the external electrode 223, which is a single electrode, is formed by separating the electrode layer 2230 into multiple independent electrodes that are separated from each other. At one end, a portion of the electrode layer 2240 remains, not reaching its full length, thus... Figure 5 As shown, in the region closer to the substrate 10 than the bottom of the groove 23, an external electrode 224, which serves as a common electrode, is formed as a continuous electrode layer 2240. In addition, at this time, a groove 101 is also formed in the electrode layer 11 in the region formed on the individual electrode side of the surface layer of the substrate 10.

[0080] Thus, a stacked piezoelectric component 201 is formed, in which the electrode layer on one end is divided into multiple parts, and the electrode layers on the other end are connected to each other on the substrate 10 side. At this time, multiple grooves 23 are formed simultaneously at predetermined intervals to divide the stacked piezoelectric component 201 into multiple parts, thereby forming multiple columnar elements as multiple piezoelectric elements 21, 22 arranged at the same interval. Thus, multiple driven piezoelectric elements 21 and non-driven piezoelectric elements 22 arranged at the same interval are formed.

[0081] Furthermore, by forming the groove 101, the electrode layer 11 on the mounting surface of the substrate 10 is separated to form a predetermined wiring pattern with a plurality of individual wirings 102.

[0082] Furthermore, on the wiring patterns such as individual wiring 102 and common wiring 103 formed in a predetermined shape on the substrate 10, an FPC 71, which serves as a control component and is equipped with electronic components such as a driver IC 72, is connected, for example, by soldering or anisotropic conductive film. A printed wiring substrate 73 having a head control circuit 731 is also connected to the FPC 71.

[0083] In addition, the vibrating plate 30, the flow path substrate 405, and the nozzle plate 50 are stacked on the actuator section 20 with bonding material sandwiched between them and positioned. The frame section 60 is disposed on the outer periphery of the actuator section 20 and these multiple components are joined together to complete the inkjet head 1.

[0084] Below, refer to Figure 8 An example of an inkjet recording apparatus 100 equipped with an inkjet head 1 will be described. The inkjet recording apparatus 100 includes a housing 111, a media supply unit 112, an image forming unit 113, a media discharge unit 114, a transport device 115, and a control unit 116.

[0085] The inkjet recording apparatus 100 is a liquid ejection device as described below: along a predetermined transport path R from the media supply unit 112 through the image forming unit 113 to the media discharge unit 114, a printing medium, such as paper P, which is the object to be ejected, is transported while liquid such as ink is ejected, thereby performing image forming processing on the paper P.

[0086] The frame 111 forms the outer contour of the inkjet recording device 100. A discharge port for discharging paper P to the outside is provided at a predetermined position on the frame 111.

[0087] The media supply unit 112 has multiple paper feed boxes, which are configured to stack and hold multiple sheets of paper P of various sizes.

[0088] The media discharge section 114 is equipped with a paper discharge tray, which is configured to hold the paper P discharged from the discharge port.

[0089] The image forming unit 113 includes a support portion 117 for supporting the paper P, and a plurality of head units 130 disposed above the support portion 117.

[0090] The support portion 117 includes: a conveyor belt 118 arranged in a ring in a predetermined area for image formation; a support plate 119 supporting the conveyor belt 118 from the inside; and a plurality of belt rollers 120 disposed on the inside of the conveyor belt 118.

[0091] During image formation, the support portion 117 supports the paper P on the holding surface, which is the upper surface of the conveyor belt 118, and conveys the conveyor belt 118 at a predetermined time by the rotation of the belt roller 120, thereby conveying the paper P to the downstream side.

[0092] The head unit 130 includes multiple (four colors) inkjet heads 1, ink tanks 132 mounted on each inkjet head 1 as liquid containers, a connection flow path 133 connecting the inkjet head 1 and the ink tank 132, and a supply pump 134.

[0093] In this embodiment, the inkjet head 1 is equipped with four colors: cyan, magenta, yellow, and black, and ink tanks 132 that respectively contain ink of these colors. The ink tanks 132 are connected to the inkjet head 1 via a flow path 133.

[0094] Furthermore, a negative pressure control device, such as a pump (not shown), is connected to the ink tank 132. In addition, corresponding to the water head value of the inkjet head 1 and the ink tank 132, the negative pressure control device controls the negative pressure inside the ink tank 132, thereby causing the ink supplied to each nozzle 51 of the inkjet head 1 to form a curved surface of a predetermined shape.

[0095] The supply pump 134 is, for example, a liquid delivery pump composed of a piezoelectric pump. The supply pump 134 is provided in the supply flow path. The supply pump 134 is configured to be connected to the control circuit 1161 of the control unit 116 via wiring, and can be controlled by the control unit 116. The supply pump 134 supplies liquid to the inkjet head 1.

[0096] The conveying device 115 conveys paper P along a conveying path R from the media supply unit 112 through the image forming unit 113 to the media discharge unit 114. The conveying device 115 includes a plurality of guide plate pairs 121 arranged along the conveying path R and a plurality of conveying rollers 122.

[0097] Each of the multiple guide plates 121 has a pair of plate components that are arranged opposite each other to clamp the paper P being conveyed, and guides the paper P along the conveying path R.

[0098] The conveying roller 122 is driven to rotate under the control of the control unit 116, thereby conveying the paper P downstream along the conveying path R. It should be noted that sensors for detecting the conveying status of the paper are arranged at various points along the conveying path R.

[0099] The control unit 116 includes a control circuit 1161 such as a CPU (Central Processing Unit) that acts as a controller, a ROM (Read Only Memory) that stores various programs, a RAM (Random Access Memory) that temporarily stores various variable data, image data, etc., and an interface unit that inputs data from the outside and outputs data to the outside.

[0100] In the inkjet recording apparatus 100 configured as described above, for example, when a user detects a printing instruction based on an operation input unit in the interface, the control unit 116 drives the transport device 115 to transport the paper P, and outputs a printing signal to the timing alignment unit 130 at a predetermined time, thereby driving the inkjet head 1. As an ejection operation, the inkjet head 1 sends a drive signal to the drive IC 72 according to the image signal corresponding to the image data, applies a drive voltage to the internal electrodes 221, 222, selectively drives the drive piezoelectric element 21 of the ejection object to make it vibrate longitudinally, for example, in the lamination direction, changes the volume of the pressure chamber 31, and ejects ink from the nozzle 51 to form an image on the paper P held on the conveyor belt 118. In addition, as a 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.

[0101] Here, the driving operation of the inkjet head 1 will be explained. The inkjet head 1 according to this embodiment includes driving piezoelectric elements 21 disposed opposite to the pressure chamber 31. These driving piezoelectric elements 21 are connected by wiring in a manner in which voltage can be applied. The control unit 116 sends a driving signal to the driving IC 72 according to the image signal corresponding to the image data, and applies a driving voltage to the internal electrodes 221, 222 of the driving piezoelectric elements 21 to selectively deform the driving piezoelectric elements 21. In addition, by combining the deformation in the tensile direction and the deformation in the compression direction of the vibrating plate 30, the volume of the pressure chamber 31 is changed, thereby ejecting liquid.

[0102] For example, the control unit 116 alternately performs stretching and compression actions. In the inkjet head 1, during stretching, which increases the volume of the pressure chamber 31 of the object, the drive piezoelectric element 21 driving the object contracts, preventing deformation of the drive piezoelectric element 21 outside the object. Furthermore, in the inkjet head 1, during compression, which decreases the volume of the pressure chamber 31 of the object, the drive piezoelectric element 21 of the object extends. It should be noted that the non-drive piezoelectric element 22 is not deformed.

[0103] According to the inkjet head 1 and inkjet recording apparatus 100 described above, a volume ejector head and liquid ejector device with high installability can be provided. That is, by adjusting the depth of the groove 23 during processing, multiple separate individual electrodes and continuous common electrodes can be easily formed, improving installability. For example, according to the inkjet head 1 and inkjet recording apparatus 100, wiring is formed on the substrate 10, and grooves 23 and 101 are simultaneously formed on the actuator section 20 and the substrate 10, making it easy to connect the wiring on the substrate 10 and the actuator section 20 with excellent precision, allowing the FPC and the like to be mounted on the substrate 10. Therefore, connection strength is ensured, reliability is improved, and a thin profile can be achieved without increasing the thickness of the connecting portion 26. Furthermore, according to the inkjet head 1 and inkjet recording apparatus 100, compared to the case where a portion of the side is cut off to separate individual electrodes, processing steps can be reduced. Moreover, since the area of ​​the common electrode is easily ensured, the increase in resistance of the common electrode can be suppressed, ensuring high print quality.

[0104] It should be noted that the present invention is not limited to the above-described embodiments. During the implementation stage, the constituent elements can be modified to be specific without departing from its spirit.

[0105] In the above embodiment, an example is shown where the entire length of the groove 101 on the substrate 10 is formed simultaneously with the groove 23; however, this is not a limitation. For example, in other embodiments of inkjet head manufacturing methods, such as... Figure 9 and Figure 10As shown, in the outer region separated from the actuator section 20 in the extending direction, patterning is performed using PEP, laser, or other means as a preliminary process to form patterned wiring 104. Furthermore, in a subsequent process, a groove 101 is formed together with a tool 282 (using a blade 2821 to bend the tool) and a groove 23, thereby forming a separate wiring 102 continuous with the outer patterned wiring 104 in the region near the actuator section 20 on the substrate 10, thus forming the desired wiring pattern. This method is effective, for example, when the spacing of the grooves in the actuator section 20 differs from the spacing of the wiring on the mounting surface, or when the wiring is elongated and difficult to mount together.

[0106] The specific materials and configurations of the piezoelectric elements 21 and 22 in the above embodiments are not limited to those described above and can be appropriately modified.

[0107] Furthermore, in the above embodiment, the piezoelectric layer 211 is configured as a multilayered piezoelectric layer, and the piezoelectric element 21 is driven by longitudinal vibration (d33) in the stacking direction. However, it is not limited to this. For example, it can also be applied to a method in which the piezoelectric element 21 is composed of a single-layered piezoelectric component, or it can be applied to a method in which it is driven by lateral vibration displaced in the d31 direction.

[0108] The arrangement of the nozzles 51 and pressure chambers 31 is not limited to the above-described embodiment. For example, the nozzles 51 may be arranged in two or more rows. In addition, an air chamber as a virtual chamber may be formed between multiple pressure chambers 31. It is not limited to a circulating type, and can also be a non-circulating inkjet head, or it is not limited to end-firing, and can also be applied to a side-firing type inkjet head.

[0109] Furthermore, an example is shown where piezoelectric elements 21 and 22 have virtual layers 212 at both ends in the stacking direction. However, this is not a limitation; the virtual layers 212 may be present only on one side of the piezoelectric elements 21 and 22, or the piezoelectric elements 21 and 22 may not have virtual layers 212. In addition, the configuration and positional relationship of various components, including the flow path component 40, the nozzle plate 50, and the frame portion 60, are not limited to the above example and can be appropriately modified.

[0110] Furthermore, in the above embodiment, an example is shown in which two actuator sections 20 are arranged on the substrate 10. However, it is not limited to this, and the number of actuator sections 20 may also be singular.

[0111] Furthermore, the sprayed liquid is not limited to ink for printing; for example, it can be a device that sprays liquid including conductive particles for forming wiring patterns on a printed wiring substrate.

[0112] Furthermore, in the above embodiments, an example of the inkjet head 1 being used in a liquid ejection device such as an inkjet recording device is shown. However, it is not limited to this. For example, it can also be used in 3D printers, industrial manufacturing machines, and medical applications, thereby achieving miniaturization, lightweighting, and low cost.

[0113] According to at least one embodiment described above, a liquid nozzle and a liquid dispensing device that improve installability can be provided.

[0114] While several embodiments have been described, these embodiments are merely illustrative and not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and likewise within the scope of the invention as described in the claims and its equivalents.

Claims

1. A liquid ejector head, comprising: A piezoelectric component is made of a piezoelectric material and has a plurality of grooves formed in one direction, and has a plurality of piezoelectric elements arranged between the grooves and a connecting portion connecting the plurality of piezoelectric elements; A substrate, joined to the connecting portion of the piezoelectric component; as well as Individual electrodes and a shared electrode are respectively formed on one side and the other side of the piezoelectric component in one direction. The groove is configured such that the depth of the end on the individual electrode side is greater than the depth of the end on the common electrode side, and the depth of the individual electrode side reaches the substrate. The bottom surface of the groove is formed into a curved shape that gradually becomes shallower from the individual electrode side toward the common electrode side. A plurality of substrate grooves are formed on the mounting surface of the substrate along the one direction, and the substrate grooves are formed continuously with the grooves.

2. The liquid ejector head according to claim 1, wherein, The individual electrodes formed on one side of one of the plurality of piezoelectric elements are separated from each other by the groove. The common electrodes formed on the other side of the plurality of piezoelectric elements are connected to each other through the connecting portion. A wiring portion is formed on the mounting surface of the piezoelectric component on the substrate, and the wiring portion has individual wiring connected to the individual electrode.

3. The liquid ejector head according to claim 1, comprising: A vibrating plate is disposed opposite to the piezoelectric component and extends in a direction intersecting the side surfaces on which the individual electrodes and the common electrode are formed. The liquid ejector head has: a plurality of pressure chambers, at least a portion of which are opposite to the vibrating plate; and a plurality of nozzles communicating with the plurality of pressure chambers.

4. The liquid ejector head according to claim 1, wherein... The piezoelectric component is a stacked piezoelectric component composed of multiple piezoelectric body layers and multiple internal electrodes.

5. The liquid ejector head according to claim 1, characterized in that, The piezoelectric element includes a driven piezoelectric element and a non-driven piezoelectric element.

6. The liquid ejector head according to claim 4, characterized in that, The piezoelectric layer is made of piezoelectric ceramic material in the form of a thin plate.

7. The liquid ejector head according to claim 4, characterized in that, The stacking direction of the piezoelectric layer is the same as the vibration direction of the piezoelectric element.

8. The liquid ejector head according to claim 3, characterized in that, Multiple nozzles are formed on a nozzle plate, which is configured as a plate with a thickness of 10 μm to 100 μm.

9. The liquid ejector head according to claim 3, characterized in that, The thickness of the vibrating plate along the vibration direction is 5μm to 15μm.

10. A liquid ejection device, comprising: The liquid ejector head according to any one of claims 1 to 9.

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