Head tip, liquid injection head, and liquid injection recording device

Abstract

It contributes to cost reduction. [Solution] A head tip according to one aspect of the present disclosure comprises a nozzle plate having nozzle holes for spraying liquid, an actuator tip provided on one side of the nozzle plate and including an actuator plate made of a piezoelectric material, wherein a pressure chamber communicating with the nozzle holes is formed to open in a first direction along one side of the nozzle plate, and a flow channel member provided on the one side of the nozzle plate and outside the actuator tip in the first direction, having a first common liquid chamber communicating with the first side of the pressure chamber in the first direction and a second common liquid chamber communicating with the second side of the pressure chamber opposite to the first side in the first direction, and also made of a material different from the piezoelectric material.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a head chip, a liquid ejection head, and a liquid ejection recording apparatus.

Background Art

[0002] In a head chip mounted on an inkjet printer, an electric field is generated in an actuator plate formed of a piezoelectric material to deform the actuator plate, thereby causing pressure fluctuations in a pressure chamber. As a result, the ink contained in the pressure chamber is ejected through a nozzle hole. Patent Document 1 discloses a structure including a cover in which nozzles are formed and a sheet in which channels for generating pressure pulses are formed in an inkjet print head. The channels are separated by side walls made of a piezoelectric material polarized in the thickness direction of the sheet. Patent Document 2 discloses that in a liquid chamber unit and an actuator unit constituting an inkjet head, the flatness of the surface composed of components and piezoelectric elements is made to be a predetermined value or less.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, in head chips installed in inkjet printers equipped with an ink circulation mechanism, the structure of the side wall of the ink circulation path communicating with the pressure chamber includes an actuator function section that functions as an actuator and an actuator non-function section that does not function as an actuator. If both the actuator function section and the actuator non-function section are made of piezoelectric material, the amount of expensive piezoelectric material used increases, which can hinder cost reduction. This problem can also occur when the actuator function section and the actuator non-function section are a single integrated structure or a multi-part structure.

[0005] This disclosure has been made in view of the above-mentioned issues and aims to contribute to reducing the cost of head chips, liquid injection heads, and liquid injection recording devices. [Means for solving the problem]

[0006] (1) A head tip according to one aspect of the present disclosure comprises: a nozzle plate having nozzle holes for spraying liquid; an actuator tip provided on one side of the nozzle plate and including an actuator plate made of a piezoelectric material, wherein a pressure chamber communicating with the nozzle holes is formed to open in a first direction along one side of the nozzle plate; and a flow channel member provided on the one side of the nozzle plate and outside the actuator tip in the first direction, having a first common liquid chamber communicating with the first side of the pressure chamber in the first direction and a second common liquid chamber communicating with the second side of the pressure chamber opposite to the first side in the first direction, and also being made of a material different from the piezoelectric material.

[0007] According to the head chip of this embodiment, the amount of expensive piezoelectric material used can be reduced compared to the case where both the actuator plate and the flow path member are made of piezoelectric material. Therefore, it contributes to cost reduction.

[0008] (2) In the head tip according to the embodiment of (1), the first common liquid chamber and the second common liquid chamber may each be partitioned by the one surface of the nozzle plate, the inner surface of the flow channel member in the first direction, and the outer surface of the actuator tip in the first direction.

[0009] This configuration eliminates the need to stack multiple components on one surface of the nozzle plate (preventing the formation of conventional joint surfaces), thus simplifying the structure and contributing to cost reduction.

[0010] (3) In the head chip according to (1) or (2), a lid member may be further provided which is joined to the actuator chip and the flow path member so as to close the first common liquid chamber and the second common liquid chamber.

[0011] With this configuration, the lid member can seal the gap between the actuator tip and the flow path member (the first common liquid chamber and the second common liquid chamber) to prevent liquid leakage.

[0012] In the head chip according to the embodiment of (4)(3), the lid member may be joined to the actuator chip and the flow path member via an adhesive.

[0013] This configuration allows for flexible adaptation to changes in the design shape of the actuator tip and flow path components, enabling the creation of a sealed structure. Since machining is not required during head tip assembly, the impact on spray performance due to the adhesion of machining dust is reduced. The lower precision required for manufacturing each component simplifies the preparation of assembly parts. Therefore, the degree of freedom in product design is increased.

[0014] (5) In the head chip according to (3) or (4), the actuator chip is formed in a shape that extends along one surface and in a second direction intersecting the first direction, and the cover member may be formed in a frame shape that covers the outer edge of the actuator chip and the flow path member when viewed from a direction intersecting the one surface.

[0015] This configuration simplifies the structure of each component, thus reducing the manufacturing cost of each component.

[0016] In the head chip according to the embodiment of (6)(5), the flow channel member may be formed in a frame shape so as to surround the actuator chip when viewed from a direction intersecting the one surface.

[0017] This configuration simplifies the structure of the flow channel component (requiring only one part), thus reducing the manufacturing cost of the flow channel component.

[0018] In a head chip according to (7), (5), or (6), a plurality of flow path members are provided at intervals in the first direction, and the plurality of flow path members may include a first flow path member that forms the first common liquid chamber and a second flow path member that forms the second common liquid chamber.

[0019] With this configuration, even if the length of the actuator chip in the first direction is changed, a common flow channel member can be used (only the distance between the first and second flow channel members in the first direction needs to be changed), thus reducing the manufacturing cost of the flow channel member.

[0020] (8) In any of the head tips according to (4) to (7), the height from the one surface of the nozzle plate to the adhesive side surface of the actuator tip in a direction intersecting the one surface may be greater than the height from the one surface of the nozzle plate to the adhesive side surface of the flow channel member.

[0021] With this configuration, even if the flatness of the flow path component is greater than the flatness of the actuator tip, the nozzle plate deforms to conform to the actuator tip, thus reducing the risk of reduced injection performance.

[0022] (9) In the head chip according to any one of aspects (4) to (7), in a direction intersecting the one surface, the height from the one surface of the nozzle plate to the surface of the actuator chip on the adhesive side may be less than or equal to the height from the one surface of the nozzle plate to the surface of the flow path member on the adhesive side.

[0023] According to this configuration, compared with the case where the height to the surface of the actuator chip on the adhesive side is higher than the height to the surface of the flow path member on the adhesive side, the amount of use of an expensive piezoelectric material can be reduced, contributing to further cost reduction.

[0024] (10) In the head chip according to any one of aspects (4) to (7), in a direction intersecting the one surface, the height from the one surface of the nozzle plate to the surface of the actuator chip on the adhesive side may be the same as the height from the one surface of the nozzle plate to the surface of the flow path member on the adhesive side.

[0025] According to this configuration, compared with the case where the height to the surface of the actuator chip on the adhesive side is different from the height to the surface of the flow path member on the adhesive side, the joining of the lid member via the adhesive becomes easier.

[0026] (11) The liquid ejection head according to one aspect of the present disclosure includes a head chip according to any one of aspects (1) to (10).

[0027] According to the liquid ejection head according to this aspect, a liquid ejection head that contributes to cost reduction can be obtained.

[0028] (12) The liquid ejection recording apparatus according to one aspect of the present disclosure includes the liquid ejection head according to aspect (11).

[0029] According to the liquid ejection recording apparatus according to this aspect, a liquid ejection recording apparatus that contributes to cost reduction can be obtained.

Brief Description of the Drawings

[0030] [Figure 1]This is a schematic diagram of the inkjet printer according to the first embodiment. [Figure 2] This is a schematic configuration of the inkjet head and ink circulation mechanism according to the first embodiment. [Figure 3] This is an exploded perspective view of the head chip according to the first embodiment. [Figure 4] This is a perspective view of the head chip according to the first embodiment. [Figure 5] This is a cross-sectional view of the head chip according to the first embodiment, corresponding to the YZ plane. [Figure 6] This is a cross-sectional view of the head tip corresponding to the YZ plane according to the first modified example of the first embodiment. [Figure 7] This is a cross-sectional view of the head tip corresponding to the YZ plane according to a second modified example of the first embodiment. [Figure 8] This is an exploded perspective view of the head chip according to the second embodiment. [Modes for carrying out the invention]

[0031] Embodiments relating to this disclosure will be described below with reference to the drawings. In the embodiments and modifications described below, corresponding components may be denoted by the same reference numerals and their descriptions may be omitted. In the following description, expressions indicating relative or absolute arrangements such as "parallel," "orthogonal," "center," and "coaxial" will not only strictly represent such arrangements, but will also represent states of relative displacement with tolerances or angles and distances that allow the same function to be obtained.

[0032] In the following embodiments, an inkjet printer (hereinafter simply referred to as "printer") that uses ink (liquid) to record on a recording medium will be described as an example of a liquid jet recording device equipped with the liquid jet head of this disclosure. In the drawings used in the following description, the scale of each component has been appropriately changed in order to make each component recognizable.

[0033] <First Embodiment> <Printer> Figure 1 is a schematic diagram of printer 1. As shown in Figure 1, the printer 1 of this embodiment includes a pair of transport mechanisms 2 and 3, an ink tank 4, an inkjet head 5 (liquid ejection head), an ink circulation mechanism 6, and a scanning mechanism 7.

[0034] In the following explanation, the Cartesian coordinate system of X, Y, and Z will be used as needed. The X direction coincides with the transport direction (sub-scanning direction) of the recording medium P (e.g., paper). The Y direction coincides with the scanning direction (main scanning direction) of the scanning mechanism 7. The Z direction indicates the height direction (gravity direction) perpendicular to the X and Y directions. In the following explanation, the direction indicated by the arrow in the diagram will be considered the positive (+) side, and the direction opposite to the arrow will be considered the negative (-) side. In this specification, the +Z side corresponds to the upward direction of gravity, and the -Z side corresponds to the downward direction of gravity.

[0035] The transport mechanisms 2 and 3 transport the recording medium P to the +X side. Each of the transport mechanisms 2 and 3 includes, for example, a pair of rollers 11 and 12 extending in the Y direction. Each ink tank 4 contains four separate inks, for example, yellow, magenta, cyan, and black. Each inkjet head 5 is configured to eject the four inks corresponding to the connected ink tank 4.

[0036] Figure 2 is a schematic diagram of the inkjet head 5 and the ink circulation mechanism 6. Referring also to Figure 2, the ink circulation mechanism 6 circulates ink between the ink tank 4 and the inkjet head 5. The ink circulation mechanism 6 comprises a circulation channel 23 having an ink supply pipe 21 and an ink discharge pipe 22, a pressure pump 24 connected to the ink supply pipe 21, and a suction pump 25 connected to the ink discharge pipe 22.

[0037] The pressurizing pump 24 pressurizes the ink supply pipe 21 and sends ink to the inkjet head 5 through the ink supply pipe 21. As a result, the ink supply pipe 21 side is under positive pressure relative to the inkjet head 5.

[0038] The suction pump 25 reduces the pressure inside the ink discharge pipe 22 and draws ink from the inkjet head 5 through the ink discharge pipe 22. As a result, there is negative pressure on the ink discharge pipe 22 side relative to the inkjet head 5. The ink can be circulated between the inkjet head 5 and the ink tank 4 through the circulation channel 23, driven by the pressurizing pump 24 and the suction pump 25.

[0039] As shown in Figure 1, the scanning mechanism 7 causes the inkjet head 5 to reciprocate in the Y direction. The scanning mechanism 7 includes a guide rail 28 extending in the Y direction and a carriage 29 movably supported on the guide rail 28.

[0040] <Inkjet head> The inkjet head 5 is mounted on a carriage 29. In the illustrated example, multiple inkjet heads 5 are mounted in a row in the Y direction on a single carriage 29. The inkjet head 5 includes a head chip 30 (see Figure 2), an ink supply unit (not shown) connecting the ink circulation mechanism 6 and the head chip 30, and a control unit (not shown) that applies a drive voltage to the head chip 30.

[0041] The inkjet head 5 of this embodiment is an electromechanical conversion type inkjet head that ejects ink from a head chip 30 which includes an actuator plate 40 formed from a piezoelectric element such as PZT (lead zirconate titanate).

[0042] In this inkjet head 5, to eject ink, a voltage is applied between the electrodes of the drive wall of the ejection channel 42 (pressure chamber) formed in the actuator plate 40, causing the drive wall to slide and deform in thickness. As a result, the volume inside the ejection channel 42 changes, and the ink inside the ejection channel 42 is ejected through the nozzle hole 31a. Note that the ink ejection method is not limited to the electromechanical conversion method described above, but may also be a charge control method, a pressurized vibration method, an electrothermal conversion method, an electrostatic attraction method, etc.

[0043] The electrostatic control method involves applying an electric charge to the material using a charging electrode and controlling the direction of the material's flight with a deflection electrode to discharge it from the nozzle. The pressurized vibration method, on the other hand, applies ultra-high pressure to the material to discharge it towards the nozzle tip. If no control voltage is applied, the material travels in a straight line and is discharged from the nozzle. When a control voltage is applied, electrostatic repulsion occurs between the material particles, causing them to scatter and not be discharged from the nozzle.

[0044] Furthermore, the electrothermal conversion method involves rapidly vaporizing the material using a heater placed within the space where the material is stored, generating bubbles, and then using the pressure of these bubbles to discharge the material from the space. The electrostatic attraction method involves applying a small amount of pressure to the space where the material is stored, forming a meniscus of material in the nozzle, and then applying electrostatic attraction to draw out the material. In addition, other technologies such as methods that utilize changes in fluid viscosity due to an electric field, and methods that use discharge sparks to propel the material can also be applied.

[0045] <Head Tip> Figure 3 is an exploded perspective view of the head tip 30 according to the first embodiment. Figure 4 is a perspective view of the head tip 30 according to the first embodiment. Figure 5 is a cross-sectional view of the head tip 30 according to the first embodiment, corresponding to the YZ plane. Referring to Figures 3 to 5, the head tip 30 is a so-called circulating side-chute type head tip that circulates ink with the ink tank 4 and ejects ink from the center of the extension direction (Y direction) of the ejection channel 42. The head tip 30 comprises a nozzle plate 31, an actuator tip 32, a flow path member 33, and a lid member 34.

[0046] <Nozzle Plate> The nozzle plate 31 is formed of, for example, a resin material (such as polyimide). The nozzle plate 31 may also be made of a single-layer or laminated structure of a metal material (such as SUS or Ni-Pd), a resin material (such as polyimide), glass, silicon, etc. The form of the nozzle plate 31 can be changed according to the design specifications.

[0047] The nozzle plate 31 has nozzle holes 31a formed therein for ejecting ink. Multiple nozzle holes 31a are formed, penetrating the nozzle plate 31 in the Z direction. The nozzle holes 31a may be formed in a tapered shape, for example, with the inner diameter gradually decreasing from top to bottom. The multiple nozzle holes 31a are spaced apart in the X direction. Each nozzle hole 31a communicates separately with a corresponding discharge channel 42. The upper end opening of each nozzle hole 31a may open, for example, in the center of the discharge channel 42 in the Y direction.

[0048] The nozzle plate 31 covers the lower surface of the actuator plate 40 and the lower surface of the flow path member 33 together. The nozzle plate 31 is joined to the lower surface of the actuator plate 40 and the lower surface of the flow path member 33 via adhesive or the like. The nozzle plate 31 covers the lower end openings of the first common liquid chamber 61 and the second common liquid chamber 62, and the lower end openings of each channel 42, 43 together.

[0049] <Actuator chip> The actuator tip 32 is provided on the +Z plane side (one side) of the nozzle plate 31. The actuator tip 32 includes an actuator plate 40 made of piezoelectric material. The actuator tip 32 is formed such that a discharge channel 42 (pressure chamber) leading to the nozzle hole 31a opens in the Y direction (first direction) along the +Z plane (one side) of the nozzle plate 31.

[0050] The actuator tip 32 is formed in a shape that follows the +Z plane of the nozzle plate 31 and extends in the X direction (a second direction intersecting the first direction). The actuator tip 32 is formed in a block shape with the Z direction as the thickness direction and the X direction as the longitudinal direction. The actuator tip 32 is fitted into the tip housing 63.

[0051] The actuator tip 32 has a thickness in the Z direction greater than that of the flow channel member 33, and its plan view shape is formed to be the same as that of the tip housing portion 63. The +X side end face of the actuator tip 32 is fixed to the inner surface of the tip housing portion 63 facing the -X side by adhesive or the like. The -X side end face of the actuator tip 32 is fixed to the inner surface of the tip housing portion 63 facing the +X side by adhesive or the like. Within the flow channel member 33, the first common liquid chamber 61 and the second common liquid chamber 62 are separated by the actuator tip 32.

[0052] The actuator chip 32 comprises an actuator plate 40 and a cover plate 50.

[0053] The actuator plate 40 is made of a piezoelectric material such as PZT (lead zirconate titanate). The actuator plate 40 is a so-called chevron substrate, which is made by laminating two piezoelectric plates with different polarization directions in the Z direction. Alternatively, the actuator plate 40 may be a so-called monopole substrate, in which the polarization direction is unidirectional throughout the entire Z direction.

[0054] The actuator plate 40 has a channel row 41 formed therein. The channel row 41 has an ejection channel 42 (pressure chamber) into which ink is filled, and a non-ejection channel 43 into which ink is not filled. The channels 42 and 43 are arranged alternately on the actuator plate 40 with spacing in the X direction.

[0055] The discharge channel 42 penetrates the actuator plate 40 in the Z direction and extends linearly in the Y direction along the entire length of the actuator plate 40. The +Y side opening of each discharge channel 42 communicates with the first common liquid chamber 61. The -Y side opening of each discharge channel 42 communicates with the second common liquid chamber 62. The first common liquid chamber 61 and the second common liquid chamber 62 communicate through each discharge channel 42.

[0056] The non-discharge channel 43 extends linearly in the Y direction from the portion of the actuator plate 40 located between adjacent discharge channels 42. The portions of the actuator plate 40 located between adjacent discharge channels 42 and non-discharge channels 43 each constitute a drive wall 44 facing the discharge channel 42. Channels 42 and 43 are surrounded on both sides in the X direction by a pair of drive walls 44.

[0057] The non-discharge channel 43 terminates at both ends in the Y direction within the actuator plate 40. The non-discharge channel 43 does not communicate with the first common liquid chamber 61 and the second common liquid chamber 62. The non-discharge channel 43 is formed in a convex arc shape that is downward when viewed from the X direction. The Y-direction dimension of the non-discharge channel 43 gradually decreases from top to bottom. Although not shown in the figures, the actuator plate 40 has common wiring and individual wiring formed therein as drive wiring.

[0058] The cover plate 50 is a component for connecting the actuator chip 32 and the flexible printed circuit board (external wiring). The cover plate 50 is a plate material made of, for example, a resin material (e.g., PI, PE, PET, PP, PEEK, etc.). The Z-axis dimension of the cover plate 50 is smaller than that of the actuator plate 40.

[0059] In addition to resin materials, the cover plate 50 may also be made of piezoelectric materials such as PZT, glass, silicon, or other non-conductive materials. Furthermore, the cover plate 50 may be made by coating the outer surface of a non-conductive material with a conductive material such as a metal material as the base.

[0060] The cover plate 50 has the same external shape as the actuator plate 40 when viewed from above. The cover plate 50 is superimposed on the entire upper surface of the actuator plate 40. The cover plate 50 is bonded to the upper surface of the actuator plate 40 by adhesive or the like.

[0061] <Flow channel component> The flow channel member 33 is provided on the +Z plane side of the nozzle plate 31, outside the actuator tip 32 in the XY plane. The flow channel member 33 has a first common liquid chamber 61 that leads to the +Y side (first side in the first direction) of the discharge channel 42, and a second common liquid chamber 62 that leads to the -Y side (second side opposite to the first side in the first direction) of the discharge channel 42.

[0062] The flow channel member 33 is formed of a material different from the piezoelectric material. For example, the flow channel member 33 is formed of a metallic material (such as SUS or Ni-Pd). In addition to metallic materials, the flow channel member 33 may also be a single-layer or laminated structure made of resin materials (such as polyimide), glass, silicon, etc. The form of the flow channel member 33 can be changed according to the design specifications, as long as it is made of a material different from the piezoelectric material.

[0063] The first common liquid chamber 61 and the second common liquid chamber 62 are each demarcated by the +Z plane of the nozzle plate 31, the Y-direction inner surface of the flow channel member 33 (the inner surface in the first direction), and the Y-direction outer surface of the actuator tip 32 (the outer surface in the first direction). The flow channel member 33 is formed in a frame shape so as to surround the actuator tip 32 when viewed from the Z direction (the direction intersecting one surface of the nozzle plate).

[0064] The flow channel member 33 is formed in the shape of a rectangular frame with the Z direction as the thickness direction and the X direction as the longitudinal direction. The flow channel member 33 separates the chip housing section 63, the first common liquid chamber 61, and the second common liquid chamber 62. The chip housing section 63, the first common liquid chamber 61, and the second common liquid chamber 62 are in communication with each other and penetrate the flow channel member 33 in the Z direction.

[0065] The chip housing portion 63 is formed in the center of the flow channel member 33 in the Y direction. In a plan view, the chip housing portion 63 is formed as an elongated hole with the X direction as its longitudinal direction.

[0066] The first common liquid chamber 61 is formed in the portion of the flow channel member 33 located on the +Y side relative to the chip housing portion 63. The first common liquid chamber 61 is formed in the same way as the chip housing portion 63, with the X direction as its longitudinal direction. The +X side end of the first common liquid chamber 61 protrudes in the X direction relative to the chip housing portion 63.

[0067] The second common liquid chamber 62 is formed in the portion of the flow channel member 33 located on the -Y side relative to the chip housing portion 63. The second common liquid chamber 62 is formed in the same way as the first common liquid chamber 61, with the X direction as its longitudinal direction. The -X side end of the second common liquid chamber 62 protrudes in the X direction relative to the chip housing portion 63.

[0068] <Lid component> The lid member 34 is joined to the actuator tip 32 and the flow path member 33 so as to close the first common liquid chamber 61 and the second common liquid chamber 62. The lid member 34 is joined to the actuator tip 32 and the flow path member 33 via adhesive 80. The lid member 34 is formed in a frame shape so as to cover the outer edge of the actuator tip 32 and the flow path member 33 when viewed from the Z direction.

[0069] The lid member 34 sandwiches the flow path member 33 and the actuator tip 32 between itself and the nozzle plate 31. The lid member 34 includes a cover base 70, an inlet port 71, and an outlet port 72.

[0070] The cover base 70 is a rectangular plate-shaped structure whose plan view outline is the same as that of the flow channel member 33. The cover base 70 is superimposed on the upper surfaces of the flow channel member 33 and the actuator tip 32. The cover base 70 is joined to the upper surfaces of the flow channel member 33 and the actuator tip 32 via adhesive 80. The cover base 70 may also be fastened to the flow channel member 33 with screws or the like. The cover base 70 closes the upper end openings of the first common liquid chamber 61 and the second common liquid chamber 62.

[0071] A slit 70a is formed in the central part of the cover base 70 in the Y direction. The slit 70a penetrates the cover base 70 in the Z direction and extends in the X direction.

[0072] The slit 70a is formed in a position that overlaps with the central part (excluding the outer periphery) of the actuator tip 32 in a plan view. The Y-direction dimension of the slit 70a is smaller than the Y-direction dimension of the actuator tip 32. The X-direction dimension of the slit 70a is smaller than the X-direction dimension of the actuator tip 32.

[0073] The inlet port 71 is located at the +Y and +X ends of the cover base 70. The inlet port 71 protrudes upward from the cover base 70. The inlet port 71 communicates with the first common liquid chamber 61 through the +X end of the first common liquid chamber 61 (the portion that protrudes relative to the chip housing 63). The ink flowing through the ink supply pipe 21 is supplied to the first common liquid chamber 61 through the inlet port 71.

[0074] The outlet port 72 is located at the -Y and -X ends of the cover base 70. The outlet port 72 protrudes upward from the cover base 70. The outlet port 72 communicates with the second common liquid chamber 62 through the -X end of the second common liquid chamber 62 (the portion that protrudes relative to the tip housing 63). The ink flowing through the second common liquid chamber 62 is discharged to the ink discharge pipe 22 through the outlet port 72.

[0075] Although not shown in the diagram, the flexible printed circuit board is pressed against the upper surface of the cover plate 50 through a slit 70a. For example, after being pulled upward, the flexible printed circuit board is connected to a control unit (not shown).

[0076] As shown in Figure 5, in the head tip 30 of this embodiment, in the Z direction, the height Z1 from the +Z plane of the nozzle plate 31 to the side of the actuator tip 32 facing the adhesive 80 is higher than the height Z2 from the +Z plane of the nozzle plate 31 to the side of the flow channel member 33 facing the adhesive 80 (Z1 > Z2).

[0077] Height Z1 corresponds to the height from the +Z plane of the nozzle plate 31 to the +Z plane of the cover plate 50. Height Z2 corresponds to the height from the +Z plane of the nozzle plate 31 to the +Z plane of the flow path member 33. For example, height Z1 may be 0.01 mm or more higher than height Z2.

[0078] <How to operate the printer> Next, we will explain the case in which characters, figures, etc., are recorded on the recording medium P using the printer 1 configured as described above. Initially, the four ink tanks 4 shown in Figure 1 are assumed to be sufficiently filled with ink of a different color. Furthermore, the ink in the ink tanks 4 is filled into the inkjet head 5 via the ink circulation mechanism 6.

[0079] Under these initial conditions, when printer 1 is activated, the recording medium P is carried to the +X side while being gripped by the rollers 11 and 12 of transport mechanisms 2 and 3. At the same time, carriage 29 moves in the Y direction, causing the inkjet head 5 mounted on carriage 29 to move back and forth in the Y direction. As the inkjet head 5 moves back and forth, ink is ejected from each inkjet head 5 onto the recording medium P as needed. This allows for the recording of characters, images, and other data onto the recording medium P.

[0080] The movement of each inkjet head 5 is described in detail below. In the circulating side-chute type inkjet head 5, ink is first circulated through the circulation channel 23 by operating the pressure pump 24 and suction pump 25 shown in Figure 2. In this case, the ink circulating in the ink supply pipe 21 is supplied to the first common liquid chamber 61 through the inlet port 71. The ink supplied to the first common liquid chamber 61 is distributed to each ejection channel 42 through the +Y side opening in each ejection channel 42, and then circulates through each ejection channel 42 to the -Y side. After that, the ink is discharged to the second common liquid chamber 62 through the -Y side opening of each ejection channel 42. The ink discharged to the second common liquid chamber 62 flows into the ink discharge pipe 22 through the outlet port 72 and is returned to the ink tank 4. This allows ink to be circulated between the inkjet head 5 and the ink tank 4.

[0081] Then, when the reciprocating movement of the inkjet head 5 begins due to the movement of the carriage 29 (see Figure 1), a drive voltage is applied between the common electrode and the individual electrodes via a flexible printed circuit board (not shown). At this time, the common electrode is set to a reference potential GND, and the individual electrodes are set to a drive potential Vdd when the drive voltage is applied. As a result, a potential difference is generated in the X direction between the common electrode and the individual electrodes facing each other across the drive wall 44. Due to the potential difference generated in the X direction, an electric field is generated in the actuator plate 40 in a direction perpendicular to the polarization direction (Z direction). As a result, the actuator plate 40 undergoes thickness sliding deformation in the Z direction due to shear mode. Specifically, thickness sliding deformation occurs in the two drive walls 44 that define the ejection channel 42, and these two drive walls 44 deform so that they protrude toward the non-ejection channel 43 side. That is, since the actuator plate 40 is made up of two piezoelectric substrates that have been polarized in the thickness direction (Z direction), when a drive voltage is applied, it bends in a V shape around the midpoint in the Z direction of the drive wall 44. As a result, the discharge channel 42 deforms as if it were expanding.

[0082] Subsequently, when the drive voltage is reduced to zero, the actuator plate 40 restores itself, causing the volume in the ejection channel 42 to return to its original state. During the process of the actuator plate 40 restoring, the pressure in the ejection channel 42 increases, and the ink in the ejection channel 42 is ejected to the outside through the nozzle hole 31a. The ink ejected to the outside lands on the recording medium P, and the printed information is recorded on the recording medium P.

[0083] <Effects and Effects> The head tip 30 of this embodiment comprises a nozzle plate 31 having nozzle holes 31a for ejecting ink, an actuator tip 32 provided on the +Z side of the nozzle plate 31 and including an actuator plate 40 made of piezoelectric material, with a discharge channel 42 leading to the nozzle holes 31a opening in the Y direction along the +Z side of the nozzle plate 31, and a flow channel member 33 provided on the +Z side of the nozzle plate 31 and outside the actuator tip 32 in the Y direction, with a first common liquid chamber 61 leading to the +Y side of the discharge channel 42 and a second common liquid chamber 62 leading to the -Y side of the discharge channel 42, and made of a material different from the piezoelectric material.

[0084] This configuration allows for a reduction in the amount of expensive piezoelectric material used compared to a case where both the actuator plate 40 and the flow path member 33 are made of piezoelectric material. Therefore, it contributes to cost reduction.

[0085] In the head tip 30 of this embodiment, the first common liquid chamber 61 and the second common liquid chamber 62 are each demarcated by the +Z plane of the nozzle plate 31, the inner surface in the Y direction of the flow path member 33, and the outer surface in the Y direction of the actuator tip 32. With this configuration, multiple components are not stacked on the +Z plane of the nozzle plate 31 (no conventional connecting surfaces are formed), thus simplifying the structure and contributing to cost reduction.

[0086] The head tip 30 of this embodiment further includes an actuator tip 32 and a lid member 34 joined to the flow path member 33 so as to close the first common liquid chamber 61 and the second common liquid chamber 62. With this configuration, the lid member 34 can seal the gap between the actuator chip 32 and the flow path member 33 (the first common liquid chamber 61 and the second common liquid chamber 62) to prevent ink leakage.

[0087] In this embodiment, the lid member 34 is joined to the actuator tip 32 and the flow path member 33 via adhesive 80. This configuration allows for flexible adaptation to sealing structures even if the design shape of the actuator chip 32 or the flow path member 33 changes. Since machining is not required during the assembly of the head chip 30, the impact on spray performance caused by the adhesion of machining dust can be reduced. The required precision for manufacturing each component is lower, making it easier to prepare the assembly components. Consequently, the degree of freedom in product design is increased.

[0088] In this embodiment, the actuator tip 32 is formed in a shape that follows the +Z plane of the nozzle plate 31 and extends in the X direction. The cover member 34 is formed in a frame shape so as to cover the outer edge of the actuator tip 32 and the flow path member 33 when viewed from the Z direction. This configuration simplifies the structure of each component, thus reducing the manufacturing cost of each component.

[0089] In this embodiment, the flow path member 33 is formed in a frame shape so as to surround the actuator tip 32 when viewed from the Z direction. This configuration simplifies the structure of the flow channel member 33 (requiring only one part), thus reducing the manufacturing cost of the flow channel member 33.

[0090] In the head tip 30 of this embodiment, in the Z direction, the height Z1 from the +Z plane of the nozzle plate 31 to the side of the actuator tip 32 facing the adhesive 80 is higher than the height Z2 from the +Z plane of the nozzle plate 31 to the side of the flow channel member 33 facing the adhesive 80 (Z1 > Z2). With this configuration, even if the flatness of the flow path member 33 is greater than the flatness of the actuator tip 32, the nozzle plate 31 deforms to conform to the actuator tip 32, thus reducing the risk of reduced injection performance.

[0091] The inkjet head 5 of this embodiment includes the head chip 30 described above. This configuration provides an inkjet head 5 that contributes to cost reduction.

[0092] The printer 1 of this embodiment includes the inkjet head 5 described above. This configuration yields a printer 1 that contributes to cost reduction.

[0093] Incidentally, in conventional ink circulation path structures, in order to ensure the quality stability of leak sealing and production stability, there is a configuration disclosed in Patent Document 1 (Japanese Patent Publication No. 2003-507213). The structure of the side wall of the ink circulation path disclosed in Patent Document 1 is an integrated structure in which the actuator functional part is also formed from a piezoelectric material such as PZT (lead zirconate titanate). Furthermore, in the case of a multi-body structure in which multiple members are laminated, it is necessary to join the PZT materials together using a technology that forms a thin, even, and uniform adhesive layer at the joint surface. When both the actuator functional part and the actuator non-functional part are formed from piezoelectric material, the amount of expensive piezoelectric material used increases, which can be an obstacle to cost reduction. This problem can also occur when the actuator functional part and the actuator non-functional part are an integrated structure or a multi-body structure (Problem 1).

[0094] Patent document 2 (Japanese Patent Publication No. Hei 8-108540) discloses that the actuator's non-functional section is composed of two components. However, variations in the clearance between the joint surfaces due to manufacturing variations in each of the two components will be large, which may raise a new challenge: how to ensure both the quality stability of leak sealing and the production stability (Problem 2). Furthermore, in the planar machining method disclosed in Patent Document 2, since two members are machined simultaneously, it is difficult to select an appropriate tool, and there are concerns about the impact on discharge performance due to the adhesion of non-PZT material machining powder to the actuator function part.

[0095] In contrast to the above, in this embodiment, the actuator plate 40 of the head tip 30 is formed of a piezoelectric material, and the flow channel member 33 is formed of a material different from the piezoelectric material. As a result, the amount of expensive piezoelectric material used can be reduced compared to the case where both the actuator plate 40 and the flow channel member 33 are formed of a piezoelectric material, thus contributing to cost reduction. Furthermore, the first common liquid chamber 61 and the second common liquid chamber 62 are each demarcated by the +Z plane of the nozzle plate 31, the inner surface in the Y direction of the flow channel member 33, and the outer surface in the Y direction of the actuator tip 32. As a result, multiple members are not stacked on the +Z plane of the nozzle plate 31 (no conventional connecting surfaces are formed), thus simplifying the structure and contributing to cost reduction. Moreover, in the Z direction, the height Z1 from the +Z plane of the nozzle plate 31 to the adhesive 80 side of the actuator tip 32 is higher than the height Z2 from the +Z plane of the nozzle plate 31 to the adhesive 80 side of the flow channel member 33. As a result, even if the flatness of the flow path member 33 is greater than the flatness of the actuator tip 32, the nozzle plate 31 deforms to conform to the actuator tip 32, thereby reducing the risk of reduced injection performance. Therefore, according to this embodiment, the conventional problems 1 and 2 described above can be solved.

[0096] <Variation> It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. In the above-described embodiment, the first common liquid chamber 61 and the second common liquid chamber 62 are each partitioned by one surface of the nozzle plate 31, the inner surface of the flow path member 33 in a first direction, and the outer surface of the actuator tip 32 in a first direction. However, the embodiment is not limited to this configuration. For example, the first common liquid chamber 61 and the second common liquid chamber 62 may each be partitioned by stacking multiple members on one surface of the nozzle plate 31. The manner in which the first common liquid chamber 61 and the second common liquid chamber 62 are partitioned can be changed according to the design specifications.

[0097] In the embodiment described above, the head tip 30 was described as further comprising a lid member 34 joined to the actuator tip 32 and the flow path member 33 so as to close the first common liquid chamber 61 and the second common liquid chamber 62, but the configuration is not limited to this. For example, the first common liquid chamber 61 and the second common liquid chamber 62 may be closed by the flow path member 33. The installation method of the lid member 34 can be changed according to the design specifications.

[0098] In the embodiment described above, the lid member 34 is described as being joined to the actuator tip 32 and the flow path member 33 via adhesive 80, but the configuration is not limited to this. For example, the lid member 34 may be joined to the actuator tip 32 and / or the flow path member 33 with fastening members such as screws. The joining method of the lid member 34 can be changed according to the design specifications.

[0099] In the embodiment described above, the actuator tip 32 is formed in a shape that extends in a second direction that intersects the first direction along one surface of the nozzle plate 31, and the cover member 34 is formed in a frame shape that covers the outer edge of the actuator tip 32 and the flow path member 33 when viewed from a direction intersecting one surface of the nozzle plate 31. However, the embodiment is not limited to this configuration. For example, the cover member 34 may be formed in a shape that includes a portion that overlaps with the actuator tip 32 when viewed from a direction intersecting one surface of the nozzle plate 31. For example, the cover member 34 may be formed by combining multiple parts. The form of the actuator tip 32 and / or the cover member 34 can be changed according to the design specifications.

[0100] Figure 6 is a cross-sectional view of the head tip 30A corresponding to the YZ plane according to the first modified example of the first embodiment. In this modified example, the same reference numerals are used for components similar to those in the above-described embodiment, and detailed descriptions are omitted. In the first embodiment described above, an example was given in which, in the Z direction, the height Z1 from the +Z plane of the nozzle plate 31 to the adhesive side of the actuator tip 32 is higher than the height Z2 from the +Z plane of the nozzle plate 31 to the adhesive side of the flow channel member 33 (Z1 > Z2). However, the embodiment is not limited to this example. For example, as shown in Figure 6, in the Z direction, the height Z1 from the +Z plane of the nozzle plate 31 to the adhesive side of the actuator tip 32 may be less than or equal to the height Z2 from the +Z plane of the nozzle plate 31 to the adhesive side of the flow channel member 33 (Z1 ≤ Z2). For example, the height Z1 may be 0.01 mm or more lower than the height Z2.

[0101] According to the configuration of the head chip 30A in the first modified example, the amount of expensive piezoelectric material used can be reduced compared to the case where the height of the actuator chip 32 to the side surface of the adhesive 80 is higher than the height of the flow channel member 33 to the side surface of the adhesive 80, thus contributing to further cost reduction.

[0102] Figure 7 is a cross-sectional view of the head tip 30B corresponding to the YZ plane according to a second modified example of the first embodiment. In this modified example, components similar to those in the above-described embodiment are denoted by the same reference numerals, and detailed descriptions are omitted. For example, as shown in Figure 7, in the Z direction, the height Z1 from the +Z plane of the nozzle plate 31 to the side of the actuator tip 32 facing the adhesive 80 may be the same as the height Z2 from the +Z plane of the nozzle plate 31 to the side of the flow channel member 33 facing the adhesive 80 (Z1=Z2).

[0103] According to the configuration of the head tip 30B in the second modified example, the joining of the lid member 34 via the adhesive 80 becomes easier compared to the case where the height of the actuator tip 32 to the side surface of the adhesive 80 is different from the height of the flow channel member 33 to the side surface of the adhesive 80.

[0104] <Second Embodiment> Figure 8 is an exploded perspective view of the head chip 230 according to the second embodiment. In the first embodiment described above, an example was given in which the flow channel member 33 is formed in a frame shape so as to surround the actuator tip 32 when viewed from the Z direction, but the embodiment is not limited to this. For example, as shown in Figure 8, multiple flow channel members 233A and 233B may be provided spaced apart in the Y direction. In the second embodiment, the same reference numerals are used for components similar to those in the embodiment described above, and detailed descriptions are omitted.

[0105] The multiple flow path members 233A, 233B include a first flow path member 233A that forms a first common liquid chamber 61 and a second flow path member 233B that forms a second common liquid chamber 62. For example, the first flow path member 233A and the second flow path member 233B may be formed in the same shape as each other. In this case, one of the first flow path member 233A and the second flow path member 233B may be positioned with its orientation reversed in the XY direction relative to the other.

[0106] The chip housing portion 63 (dashed line in the figure) is formed between the first flow channel member 233A and the second flow channel member 233B in the Y direction. In a plan view, the chip housing portion 63 is formed as an elongated slit with the X direction as its longitudinal direction.

[0107] The first common liquid chamber 61 is formed in the portion of the first flow channel member 233A located on the +Y side relative to the chip housing portion 63. The first common liquid chamber 61 is formed in the same way as the chip housing portion 63, with the X direction as its longitudinal direction. The +X side end of the first common liquid chamber 61 protrudes in the X direction relative to the chip housing portion 63.

[0108] The second common liquid chamber 62 is formed in the portion of the second flow channel member 233B located on the -Y side with respect to the chip housing portion 63. The second common liquid chamber 62 is formed in the same way as the first common liquid chamber 61, with the X direction as its longitudinal direction. The -X side end of the second common liquid chamber 62 protrudes in the X direction relative to the chip housing portion 63.

[0109] In this embodiment, multiple flow path members 233A and 233B are provided at intervals in the Y direction. The multiple flow path members 233A and 233B include a first flow path member 233A that forms a first common liquid chamber 61 and a second flow path member 233B that forms a second common liquid chamber 62. With this configuration, even if the length of the actuator chip 32 in the Y direction is changed, common flow path members 233A and 233B can be used (only the distance between the first flow path member 233A and the second flow path member 233B in the Y direction needs to be changed), thus reducing the manufacturing cost of the flow path members 233A and 233B.

[0110] Although not shown in the diagram, the lid member 34 may also be divided in accordance with the division of the flow channel members 233A and 233B. In addition, a recess may be provided on the -Z side (common flow channel side) of the lid member 34 to increase the volume of the common liquid chambers 61 and 62.

[0111] (Other variations) The scope of this disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of this disclosure. For example, in the embodiment described above, an inkjet printer was used as an example of a liquid jet recording device, but it is not limited to a printer. For example, the liquid jet recording device may be a fax machine or an on-demand printer, etc. In the embodiments described above, a configuration in which the inkjet head moves relative to the recording medium during printing (a so-called shuttle machine) was used as an example, but the invention is not limited to this configuration. The configuration according to this disclosure may also be adopted in a configuration in which the recording medium moves relative to the inkjet head while the inkjet head is fixed (a so-called fixed-head machine). In the embodiments described above, the case where the recording medium is paper was explained, but the configuration is not limited to this. The recording medium is not limited to paper; it may be a metal material, a resin material, or even food. In the embodiments described above, a configuration in which the liquid spray head is mounted on a liquid spray recording device was described, but the configuration is not limited to this. That is, the liquid sprayed from the liquid spray head is not limited to what is to be sprayed onto the recording medium, but may also be, for example, a drug solution to be mixed in a compounding agent, a food additive such as a seasoning or flavoring to be added to food, or a fragrance to be sprayed into the air. In the embodiments described above, a configuration in which the Z direction coincides with the direction of gravity was explained, but the configuration is not limited to this. For example, the Z direction may coincide with the horizontal direction.

[0112] In the embodiment described above, a discharge channel that serves as a pressure chamber is formed in the actuator plate itself, and the direction of the pressure applied to the ink and the direction of ink discharge intersect, a so-called wall-vent type actuator tip was used as an example. However, the configuration is not limited to this. A roof-chute type actuator tip (where the direction of the pressure applied to the ink and the direction of ink discharge are the same) may also be used.

[0113] The embodiments described above describe a side-chute actuator chip, but are not limited to this. For example, the above embodiments may be appropriately applied to a so-called edge-chute type actuator chip that ejects ink from the extending end of the ejection channel.

[0114] Furthermore, without departing from the spirit of the present invention, the components in the embodiments described above can be replaced with well-known components as appropriate, and the modifications described above can be combined as appropriate.

[0115] While preferred embodiments and variations of the Disclosure have been described and explained above, it should be understood that these are illustrative examples of the Disclosure and should not be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the Disclosure. Therefore, the Disclosure should not be considered limited by the foregoing description, but rather limited by the claims. [Explanation of Symbols]

[0116] 1. Printer (liquid jet recording device) 5. Inkjet head (liquid jet head) 30, 30A, 30B, 230… Head tips 31… Nozzle plate 31a ... Nozzle hole 32… Actuator chip 33 ... Flow channel component 34 ... Lid component 40… Actuator plate 42 … Discharge channel (pressure chamber) 61 … 1st common liquid chamber 62 … 2nd common liquid chamber 80… Adhesive 233A … First flow channel member 233B … Second flow channel member Z1… Height from one side of the nozzle plate to the adhesive side of the actuator tip. Z2… Height from one side of the nozzle plate to the adhesive side of the flow path component.

Claims

1. A nozzle plate having nozzle holes formed for spraying liquid, An actuator tip is provided on one side of the nozzle plate and includes an actuator plate made of piezoelectric material, wherein a pressure chamber communicating with the nozzle hole is formed to open in a first direction along one side of the nozzle plate, The nozzle plate is provided on one side of the nozzle plate, outside the actuator tip in the first direction, and comprises a first common liquid chamber that leads to the first side of the pressure chamber in the first direction, and a second common liquid chamber that leads to the second side of the pressure chamber opposite to the first side in the first direction, and a flow path member made of a material different from the piezoelectric material. Head tip.

2. Each of the first common liquid chamber and the second common liquid chamber is demarcated by the one surface of the nozzle plate, the inner surface of the flow path member in the first direction, and the outer surface of the actuator tip in the first direction. The head tip according to claim 1.

3. The device further comprises a lid member joined to the actuator tip and the flow path member so as to close the first common liquid chamber and the second common liquid chamber, The head tip according to claim 1 or 2.

4. The lid member is joined to the actuator tip and the flow path member via adhesive. The head tip according to claim 3.

5. The actuator tip is formed in a shape that extends along one surface and in a second direction intersecting the first direction, The cover member is formed in a frame shape so as to cover the outer edge of the actuator tip and the flow path member when viewed from a direction intersecting the one surface. The head tip according to claim 3.

6. The flow channel member is formed in a frame shape so as to surround the actuator tip when viewed from a direction intersecting the one surface. The head tip according to claim 5.

7. Multiple flow path members are provided at intervals in the first direction. The multiple flow channel members are, The first flow channel member forming the first common liquid chamber, Including a second flow channel member that forms the second common liquid chamber, The head tip according to claim 5.

8. In a direction intersecting the aforementioned surface, the height from the aforementioned surface of the nozzle plate to the adhesive-side surface of the actuator tip is greater than the height from the aforementioned surface of the nozzle plate to the adhesive-side surface of the flow path member. The head tip according to claim 4.

9. In a direction intersecting the aforementioned surface, the height from the aforementioned surface of the nozzle plate to the adhesive-side surface of the actuator tip is less than or equal to the height from the aforementioned surface of the nozzle plate to the adhesive-side surface of the flow channel member. The head tip according to claim 4.

10. In a direction intersecting the aforementioned surface, the height from the aforementioned surface of the nozzle plate to the adhesive-side surface of the actuator tip is the same as the height from the aforementioned surface of the nozzle plate to the adhesive-side surface of the flow path member. The head tip according to claim 4.

11. A head tip comprising the head tip described in claim 1 or 2, Liquid spray head.

12. A liquid spray head as described in claim 11, Liquid injection recording device.

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