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

Abstract

The objective is to suppress non-conductivity caused by disconnection of electrodes formed in non-injection channels, thereby improving the reliability of the drive system. [Solution] The head chip 50 has an actuator plate 53 formed alternately in the X-axis direction with an ink ejection channel 61 filled with ink and a non-ejection channel 62 not filled with ink, each extending in the Y-axis direction, and a drive wall 65 in between. It also includes a common electrode 85 formed on the inner surface of the ejection channel 61 and individual electrodes 88 formed on the inner surface of the non-ejection channel 62. The actuator plate 53 has a first main surface 53A facing the -Z side, which is provided with an individual electrode power supply unit 89 located on the -Y side of the first opening 61A that supplies driving power to a pair of individual electrodes 88 that sandwich the ejection channel 61 in the X-axis direction, and a bypass wiring 95 located on the +Y side of the first opening 61A that connects the pair of individual electrodes 88.

Description

Technical Field

[0005]

[0001] The present disclosure relates to a head chip, a liquid injection head, and a liquid injection recording apparatus.

Background Art

[0002] Patent Document 1 below discloses a liquid injection head that includes an actuator plate for applying pressure to a liquid and a wiring board, and that injects the liquid. The actuator plate includes a first surface, a second surface facing the opposite side of the first surface, and openings in at least one of the first surface and the second surface, and discharge channels and non-discharge channels that are separated from each other and arranged alternately.

[0003] A common electrode is provided on the side wall of the discharge channel. An individual electrode electrically separated from the common electrode is provided on the side wall of the non-discharge channel. A common electrode pad for electrically connecting the common electrode and the wiring board is provided on the first surface, and a bypass wiring for electrically connecting the individual electrodes of adjacent non-discharge channels is provided on the second surface.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above prior art, when a disconnection occurs in either one of the individual electrodes of adjacent non-discharge channels, conduction can be ensured for a disconnection of an individual electrode that occurred on the front side (tail side) of the bypass wiring, but conduction cannot be ensured for a disconnection of an individual electrode that occurred on the back side (opposite side of the tail) of the bypass wiring.

[0006] This disclosure aims to improve the reliability of the drive by suppressing non-conductivity due to disconnection of electrodes formed in non-injection channels. [Means for solving the problem]

[0007] To address the above issues, this disclosure adopts the following characteristics. (1) A head chip according to one aspect of the present invention comprises an actuator plate having injection channels filled with liquid and non-injection channels not filled with liquid, each extending in a first direction and alternately formed in a second direction intersecting the first direction with a drive wall in between; a first electrode formed on the inner surface of the injection channels and a second electrode formed on the inner surface of the non-injection channels, wherein the actuator plate has a first main surface facing one side of the first direction and a third direction intersecting the second direction, a second electrode power supply unit arranged on one side of the injection channels that open on the first main surface in the first direction and supplying driving power to a pair of second electrodes that sandwich the injection channels in the second direction, and a bypass wiring arranged on the other side of the first openings that sandwich the first direction and connecting the pair of second electrodes. According to this embodiment, even if a break occurs in one of the pair of second electrodes, power can be supplied from the second electrode power supply section through the other second electrode that is not broken, and through the bypass wiring to the other second electrode, thereby improving the reliability of the drive. Furthermore, since the bypass wiring is formed on the first main surface of the actuator plate, it can be formed simultaneously with other conductor patterns, thereby suppressing cost increases and lead time increases due to the increased manufacturing process.

[0008] (2) In the head chip according to the embodiment of (1) above, the first main surface is provided with a first electrode power supply unit formed in an annular shape along the opening edge of the first opening and connected to the first electrode, and when the shortest distance between the first electrode power supply unit and the bypass wiring is D1, and the shortest distance between the first electrode power supply unit and the second electrode is D2, the relationship D1 > D2 may exist. According to this embodiment, by making the shortest distance between the first electrode power supply unit and the bypass wiring greater than the shortest distance between the first electrode power supply unit and the second electrode, it is possible to suppress the occurrence of a short circuit caused by liquid being spread between the first electrode power supply unit and the bypass wiring, thereby improving the reliability of the drive.

[0009] (3) In the head chip according to the embodiment of (1) or (2) above, the first main surface is provided with a first electrode power supply section formed in an annular shape along the opening edge of the first opening and connected to the first electrode, and when the shortest distance between the first electrode power supply section and the bypass wiring is D1, and the shortest distance between the first electrode and the second electrode is D3, the relationship D1 ≥ D3 may exist. According to this embodiment, by making the shortest distance between the first electrode power supply unit and the bypass wiring greater than or equal to the shortest distance between the first electrode and the second electrode (i.e., the thickness of the drive wall), sufficient distance between the first electrode power supply unit and the bypass wiring can be secured, and the occurrence of a short circuit caused by liquid being spread between the first electrode power supply unit and the bypass wiring can be more reliably suppressed.

[0010] (4): In a head chip according to any of the embodiments of (1) to (3) above, the first main surface is provided with a first electrode power supply portion formed in an annular shape along the opening edge of the first opening and connected to the first electrode, and a dividing groove extending in the second direction and separating the first electrode power supply portion and the second electrode power supply portion, wherein the relationship W1 ≥ W2 is obtained when the minimum width of the bypass wiring is W1 and the minimum width of the second electrode in the portion where the dividing groove is provided is W2. According to this embodiment, the minimum width of the bypass wiring is greater than or equal to the minimum width of the second electrode in the portion where the dividing groove is provided, thereby preventing the wiring resistance in the bypass wiring from becoming higher than that portion. This prevents the bypass wiring from being disconnected due to the electrical load during driving (discharging).

[0011] (5) In a head chip according to any of the embodiments of (1) to (4) above, the injection channel has a tapered portion in which the dimension in the first direction gradually decreases as viewed from the second direction toward one side of the third direction, and the bypass wiring may be formed to intersect with the tapered portion when viewed from the third direction. According to this embodiment, by providing the bypass wiring so as to intersect with the formation range of the cut-off portion, it is possible to suppress the enlargement of the actuator plate in the first direction caused by adding the bypass wiring.

[0012] (6) In a head chip according to any of the embodiments of (1) to (5) above, the first main surface is provided with a first electrode power supply section formed in an annular shape along the opening edge of the first opening and connected to the first electrode, and a bypass groove extending in the second direction on one side of the first opening sandwiched in the first direction, and the bypass wiring may be formed in the bypass groove. According to this embodiment, by providing a bypass groove, the bypass wiring is not formed on the same plane as the first electrode power supply unit, and the occurrence of a short circuit caused by liquid being spread between the first electrode power supply unit and the bypass wiring can be reliably suppressed.

[0013] (7) In a head chip according to any of the embodiments of (1) to (6) above, the first main surface is provided with a first electrode power supply section formed in an annular shape along the opening edge of the first opening and connected to the first electrode, and a dividing groove extending in the second direction and separating the first electrode power supply section and the second electrode power supply section, and the second main surface of the actuator plate facing the other side in the third direction is provided with a second bypass wiring positioned between the second opening of the injection channel that opens on the second main surface and the dividing groove in the first direction, extending in the second direction and connecting the pair of second electrodes. According to this embodiment, the risk of wire breakage in the divided groove portion where the width of the second electrode becomes narrower can be avoided by the second bypass wiring.

[0014] (8): The liquid ejection head according to the present disclosure includes a head chip according to any one of the aspects (1) to (7) above. According to this aspect, the reliability of driving can be enhanced.

[0015] (9): The liquid ejection recording apparatus according to the present disclosure includes the liquid ejection head according to the aspect (8) above. According to this aspect, the reliability of driving can be enhanced.

Effects of the Invention

[0016] According to one aspect of the present disclosure, it is possible to suppress non - conduction due to disconnection of an electrode formed in a non - ejection channel and enhance the reliability of driving.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic configuration diagram of a printer according to the first embodiment. [Figure 2] It is a schematic configuration diagram of an inkjet head and an ink circulation mechanism according to the first embodiment. [Figure 3] It is an exploded perspective view of a head chip according to the first embodiment. [Figure 4] It is a cross - sectional view corresponding to the line IV - IV in FIG. 3. [Figure 5] It is a main - part configuration diagram of an actuator plate according to the first embodiment. [Figure 6] It is a flowchart showing a manufacturing method of a head chip according to the first embodiment. [Figure 7] It is a main - part configuration diagram of an actuator plate according to the second embodiment. [Figure 8] It is a main - part configuration diagram of an actuator plate according to the third embodiment. [Figure 9] It is a main - part configuration diagram of an actuator plate according to the fourth embodiment.

Modes for Carrying Out the Invention

[0018] Embodiments relating to this disclosure will be described below with reference to the drawings. In the embodiments and modifications described below, corresponding components may be denoted by the same reference numerals and their descriptions omitted. In the following description, expressions indicating relative or absolute arrangements such as "parallel," "orthogonal," "center," and "coaxial" will not only strictly represent such arrangements, but also represent states of relative displacement with tolerances or angles and distances that allow the same function to be obtained. In the following embodiments, an inkjet printer (hereinafter simply referred to as "printer") that uses ink (liquid) to record on a recording medium will be used as an example. In the drawings used in the following description, the scale of each component has been appropriately changed in order to make each component recognizable.

[0019] (First Embodiment) Figure 1 is a schematic diagram of the printer 1 according to the first embodiment. As shown in Figure 1, the printer 1 (liquid jet recording device) comprises transport mechanisms 2 and 3, an ink tank 4, an inkjet head 5 (liquid jet head), an ink circulation mechanism 6, and a scanning mechanism 7.

[0020] In the following explanation, the Cartesian coordinate system of X, Y, and Z will be used as needed. In this case, the X-axis direction coincides with the transport direction (sub-scanning direction) of the recording medium P (e.g., paper). The Y-axis direction coincides with the scanning direction (main scanning direction) of the scanning mechanism 7. The Z-axis direction represents the height direction (gravity direction) perpendicular to the X-axis and Y-axis directions. In the following explanation, the side indicated by the arrow in the figure will be considered the positive (+) side, and the side opposite the arrow will be considered the negative (-) side. In Figure 1, the +Z side corresponds to the upper side in the direction of gravity, and the -Z side corresponds to the lower side in the direction of gravity.

[0021] 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-axis direction. The ink tank 4 contains, for example, four colors of ink: yellow, magenta, cyan, and black. The inkjet head 5 is configured to eject the four colors of ink, yellow, magenta, cyan, and black, depending on the connected ink tank 4. The ink contained in the ink tank 4 can be exemplified by water-based ink (conductive ink) that uses water as a solvent.

[0022] Figure 2 is a schematic diagram of the inkjet head 5 and ink circulation mechanism 6 according to the first embodiment. As shown in Figure 2, the ink circulation mechanism 6 circulates ink between the ink tank 4 and the inkjet head 5. Specifically, the ink circulation mechanism 6 includes a circulation channel 23 having an ink supply pipe 21 and an ink discharge pipe 22, a pressure pump 24 connected to the ink supply pipe 21, and a suction pump 25 connected to the ink discharge pipe 22.

[0023] The pressure 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. 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, the ink discharge pipe 22 side is under negative pressure relative to the inkjet head 5. The ink circulates 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.

[0024] As shown in Figure 1, the scanning mechanism 7 causes the inkjet head 5 to reciprocate in the Y-axis direction. The scanning mechanism 7 includes a guide rail 28 extending in the Y-axis direction and a carriage 29 movably supported on the guide rail 28.

[0025] The inkjet head 5 is mounted on a carriage 29. In the illustrated example, multiple inkjet heads 5 are mounted on a single carriage 29 in a line along the Y-axis. The inkjet head 5 includes a head chip 50 (see Figure 3), an ink supply unit (not shown) connecting the ink circulation mechanism 6 and the head chip 50, and a control unit (not shown) that applies a drive voltage to the head chip 50.

[0026] Figure 3 is an exploded perspective view of the head chip 50 according to the first embodiment. The head tip 50 shown in Figure 3 is a so-called circulating side-chute type head tip 50 that ejects ink from the center of the elongation direction (Y-axis direction) of the ejection channel 61. The head tip 50 comprises a nozzle plate 51, an intermediate plate 52 (joining member), an actuator plate 53, and a cover plate 54. The head tip 50 is configured in which the nozzle plate 51, intermediate plate 52, actuator plate 53, and cover plate 54 are stacked in this order in the Z-axis direction (third direction).

[0027] The actuator plate 53 is formed from a piezoelectric material containing an oxide, such as PZT (lead zirconate titanate). The actuator plate 53 is a so-called monopole substrate, for example, in which the polarization direction is set to one direction in the Z-axis direction. However, the actuator plate 53 may also be a so-called chevron substrate in which the polarization direction differs between the positive and negative sides in the Z-axis direction.

[0028] An actuator plate 53 has a channel row 60 formed thereon. The channel row 60 has ejection channels 61 (injection channels) into which ink is filled, and non-ejection channels 62 (non-injection channels) into which ink is not filled. The ejection channels 61 and non-ejection channels 62 are arranged alternately on the actuator plate 53 with spacing in the X-axis direction (second direction). In the first embodiment, a configuration in which the channel extension direction (first direction) coincides with the Y-axis direction is described, but the channel extension direction may intersect with the Y-axis direction.

[0029] Figure 4 is a cross-sectional view corresponding to the line IV-IV in Figure 3. As shown in Figure 4, the discharge channel 61 is formed in a convex arc shape that curves downward (to one side of the third direction) when viewed from the X-axis direction. That is, the dimension of the discharge channel 61 in the Y-axis direction gradually decreases from top to bottom. Specifically, the discharge channel 61 includes a through portion 61a located in the center in the Y-axis direction, and upward-curving portions 61b that are connected to both sides of the through portion 61a in the Y-axis direction.

[0030] The through-section 61a penetrates the actuator plate 53 in the Z-axis direction. The intermediate region of the through-section 61a in the Y-axis direction constitutes a uniform section 63 in which the dimensions in the X-axis direction are uniform throughout the entire Z-axis direction. The portions of the through-section 61a located on both sides of the uniform section 63 in the Y-axis direction constitute a variation section 64. In the variation section 64, the dimensions in the X-axis direction (distance between the inner surfaces of the discharge channel 61) gradually decrease from top to bottom. Note that the through-section 61a may also be configured without the variation section 64.

[0031] The cut-off portion 61b opens on the upper surface of the actuator plate 53, and its dimension in the Z-axis direction gradually decreases as it moves away from the through-hole portion 61a in the Y-axis direction. That is, the upper end opening of the discharge channel 61 is formed by the through-hole portion 61a and the cut-off portion 61b. On the other hand, the lower end opening of the discharge channel 61 is formed by the through-hole portion 61a. The bottom surface of the cut-off portion 61b is formed in the shape of a circular arc with a uniform radius of curvature.

[0032] As shown in Figure 3, the non-discharge channel 62 extends linearly in the Y-axis direction, penetrating the actuator plate 53 in the Z-axis direction. The portions of the actuator plate 53 located between adjacent discharge channels 61 and non-discharge channels 62 each constitute a drive wall 65. Therefore, channels 61 and 62 are surrounded on both sides in the X-axis direction by a pair of drive walls 65.

[0033] In this embodiment, a head tip 50 with one row of channel rows 60 is described as an example, but multiple rows of channel rows 60 may be provided in the Y-axis direction. In this case, it is preferable that the ejection channels 61 constituting adjacent channel rows 60 are arranged with a shift of 1 / n pitch relative to the arrangement pitch of the ejection channels 61 in one channel row 60, where n is the number of channel rows 60.

[0034] The head tip 50 includes a treated film 110 and a protective film 120. The treated film 110 is for ensuring the bonding strength between the actuator plate 53 and the adhesive, and is subjected to a surface treatment such as silane coupling treatment. However, the treated film 110 is not limited to silane coupling treatment as long as the bonding strength with the actuator plate 53 is higher than the bonding strength between the actuator plate 53 and the adhesive.

[0035] The protective film 120 protects the electrodes formed on the actuator plate 53 from ink. The protective film 120 is formed of an organic insulating material such as a paraxylylene-based resin material (e.g., parylene®). However, the protective film 120 may be composed of tantalum oxide (Ta2O5), silicon nitride (SiN), silicon carbide (SiC), silicon oxide (SiO2), or diamond-like carbon, and may contain at least one of these.

[0036] As shown in Figures 3 and 4, the cover plate 54 is bonded to the upper surface of the actuator plate 53 via adhesive 70 so as to cover the upper end openings of each channel 61, 62. For example, an epoxy adhesive is used as the adhesive 70.

[0037] In the cover plate 54, a common inlet ink chamber 71 is formed at a position that overlaps with the -Y side end of the channel row 60 in a plan view. The common inlet ink chamber 71 extends in the X-axis direction with a length that spans the channel row 60, for example, and opens on the upper surface of the cover plate 54.

[0038] In the common inlet ink chamber 71, an inlet slit 72 is formed at a position that overlaps with the ejection channel 61 in a plan view. The inlet slit 72 separately connects the -Y side end of each ejection channel 61 to the inside of the common inlet ink chamber 71.

[0039] In the cover plate 54, a common outlet ink chamber 75 is formed at a position that overlaps with the +Y side end of the channel row 60 in a plan view. The common outlet ink chamber 75 extends in the X-axis direction with a length that spans the channel row 60, for example, and opens on the upper surface of the cover plate 54.

[0040] In the common exit ink chamber 75, an exit slit 76 is formed at a position that overlaps with the non-discharge channel 62 in a plan view. The exit slit 76 separately connects the +Y side end of each discharge channel 61 to the inside of the common exit ink chamber 75. Therefore, the inlet slit 72 and the exit slit 76 communicate with each discharge channel 61, but not with the non-discharge channel 62.

[0041] The intermediate plate 52 is bonded to the lower surface of the actuator plate 53 via adhesive 77. The intermediate plate 52 is made of a material such as polyimide and has a thickness of several tens of micrometers (for example, 50 micrometers). The intermediate plate 52 may also be made of a material other than polyimide (for example, a piezoelectric material such as PZT or a nonconductive material such as alumina).

[0042] A communication hole 52a is formed in the intermediate plate 52 at a position that overlaps with the discharge channel 61 (through portion 61a) in a plan view. The communication hole 52a penetrates the intermediate plate 52 in the Z-axis direction. The communication hole 52a communicates with the inside of the discharge channel 61 through the lower end opening of the discharge channel 61. Note that the intermediate plate 52 is not an essential component.

[0043] The nozzle plate 51 is joined to the lower surface of the intermediate plate 52 via adhesive 78. The nozzle plate 51 is formed from a metal material (such as SUS or Ni-Pd) to a thickness of approximately 50 μm. However, the nozzle plate 51 may be a single-layer or laminated structure made of a resin material (such as polyimide), glass, silicon, etc., in addition to a metal material.

[0044] The nozzle plate 51 has a plurality of nozzle holes 51a that penetrate the nozzle plate 51 in the Z-axis direction. The nozzle holes 51a are tapered, for example, with the inner diameter gradually decreasing from top to bottom. The nozzle holes 51a are spaced apart in the X-axis direction. Each nozzle hole 51a communicates separately with the corresponding discharge channel 61 through a communication hole 52a. Therefore, each non-discharge channel 62 does not communicate with a nozzle hole 51a and is covered from below by the nozzle plate 51.

[0045] The actuator plate 53 has common wiring 81 and individual wiring (not shown in Figure 4) formed on it. The common wiring 81 includes a common electrode 85 (first electrode) and a common electrode power supply section 86 (first electrode power supply section). The common electrode 85 is formed in pairs on the inner surfaces of the discharge channel 61, facing each other in the X-axis direction. Each common electrode 85 is formed in the lower half of the inner surface of the discharge channel 61 (through section 61a).

[0046] The common electrode power supply section 86 surrounds the lower end opening edge of the discharge channel 61 on the lower surface of the actuator plate 53 and connects the pair of common electrodes 85. The common electrode power supply section 86 includes an extraction section 86a and a connection section 86b. The extraction sections 86a are formed on both sides in the X-axis direction of the lower end opening edge of the discharge channel 61. The connection section 86b is formed on the lower surface of the actuator plate 53 in the part located on the -Y side with respect to the discharge channel 61 (hereinafter referred to as the tail section 90).

[0047] The connecting portion 86b is provided on the lower surface of the tail portion 90, corresponding to each discharge channel 61. Each connecting portion 86b extends linearly in the Y-axis direction relative to the corresponding discharge channel 61. The +Y side end of the connecting portion 86b is connected to each of the pair of take-out portions 86a. In the illustrated example, the +Y side end of the connecting portion 86b reaches the -Y side edge of the lower end opening edge of the discharge channel 61.

[0048] An individual electrode power supply section 89 (second electrode power supply section) is formed on the lower surface of the tail section 90. The individual electrode power supply section 89 is formed on the lower surface of the tail section 90 in a part located on the -Y side than the common electrode power supply section 86. The individual electrode power supply section 89 connects individual electrodes 88 (see Figure 5, described later) that face each other in the X-axis direction with the discharge channel 61 in between, at the lower end opening edge of non-discharge channels 62 that face each other in the X-axis direction with the discharge channel 61 in between.

[0049] In the tail section 90, a partition groove 91 (dividing groove) is formed in the portion located between the common electrode power supply section 86 and the individual electrode power supply section 89. The partition groove 91 extends in the X-axis direction in the tail section 90. The partition groove 91 separates the common electrode power supply section 86 and the individual electrode power supply section 89. A flexible printed circuit board 92 is crimped to the lower surface of the tail section 90. The flexible printed circuit board 92 is connected to the common electrode power supply section 86 and the individual electrode power supply section 89 on the lower surface of the tail section 90. The flexible printed circuit board 92 is pulled upward through the outside of the actuator plate 53.

[0050] Figure 5 is a diagram showing the main components of the actuator plate 53 according to the first embodiment. Figure 5(a) is a perspective view of a part of the actuator plate 53 viewed from the -Z side. Figure 5(b) is a plan view of a part of the actuator plate 53 viewed from the -Z side. Figure 5(c) is a side view of a part of the actuator plate 53 viewed from the -X side. Similar diagrams are shown in Figures 7 to 9, which will be described later. In the following explanation, the surface of the actuator plate 53 facing the -Z side (one side of the third direction) is referred to as the first main surface 53A, and the surface of the actuator plate 53 facing the +Z side (the other side of the third direction) is referred to as the second main surface 53B.

[0051] As shown in Figure 5, the individual wiring comprises individual electrodes 88 (second electrodes) and the individual electrode power supply unit 89 described above. The individual electrodes 88 are formed on the inner surfaces of each non-discharge channel 62 that face each other in the X-axis direction. In the illustrated example, the individual electrodes 88 are formed on approximately half of the inner surface of the non-discharge channel 62. Note that the individual electrodes 88 only need to be formed in an area that overlaps with at least the common electrode 85 when viewed from the X-axis direction, as long as conductivity with the individual electrode power supply unit 89 is ensured. The individual electrode power supply unit 89 is formed on the -Y side of the tail portion 90 and supplies driving power to a pair of individual electrodes 88 that sandwich the discharge channel 61 in the X-axis direction.

[0052] A first opening 61A (lower end opening) of the discharge channel 61 is formed on the first main surface 53A of the actuator plate 53. In Figure 5, the first opening 61A is shown as a rectangle extending in the Y-axis direction in a plan view, but its opening end is actually an arc or tapered shape and is not limited to this shape. The same applies to Figures 7 to 9, which will be described later. A common electrode power supply section 86 is formed at the opening edge of the first opening 61A on the first main surface 53A. The common electrode power supply section 86 is formed as a rectangular ring extending in the Y-axis direction in a plan view. The common electrode power supply section 86 is connected to a pair of common electrodes 85 formed on the inner surface of the discharge channel 61.

[0053] On the first main surface 53A of the actuator plate 53, an individual electrode power supply section 89 and a bypass wiring 95 are formed, sandwiching the first opening 61A and the common electrode power supply section 86 in the Y-axis direction (first direction). The individual electrode power supply section 89 is positioned on the -Y side (one side in the first direction) relative to the first opening 61A and the common electrode power supply section 86, and is connected to the -Y side end of a pair of individual electrodes 88 that sandwich the discharge channel 61 in the X-axis direction.

[0054] The bypass wiring 95 is positioned on the +Y side (the other side in the first direction) relative to the first opening 61A and the common electrode power supply section 86, and connects the pair of individual electrodes 88 that sandwich the discharge channel 61 in the X-axis direction. The bypass wiring 95 is a conductor of a constant width extending in the X-axis direction and connects the +Y side ends of the pair of individual electrodes 88. By connecting the pair of individual electrodes 88 on the opposite side of the individual electrode power supply section 89 relative to the first opening 61A and the common electrode power supply section 86, the bypass wiring 95 ensures that even if one of the individual electrodes 88 is disconnected, driving power can be supplied to the other via the other. This bypass wiring 95 is formed in the same process as the common electrode 85, the common electrode power supply section 86, the individual electrodes 88, and the individual electrode power supply section 89, as will be described later.

[0055] The bypass wiring 95 is formed with a gap between it and the common electrode power supply section 86. When the shortest distance between the common electrode power supply section 86 and the bypass wiring 95 is D1, and the shortest distance between the common electrode power supply section 86 and the individual electrodes 88 is D2, the relationship D1 > D2 holds true. In other words, the bypass wiring 95 is formed further away from the common electrode power supply section 86 than the individual electrodes 88. Furthermore, the shortest distance D2 between the common electrode power supply section 86 and the individual electrodes 88 is designed to suppress the occurrence of short circuits caused by ink being passed across them.

[0056] Furthermore, when the shortest distance between the common electrode power supply section 86 and the bypass wiring 95 is D1, and the shortest distance between the common electrode 85 and the individual electrode 88 is D3, the relationship D1 ≥ D3 holds. The shortest distance D3 between the common electrode 85 and the individual electrode 88 corresponds to the thickness of the drive wall 65 in the X-axis direction. In other words, the bypass wiring 95 is formed at a distance sufficiently greater than the thickness of the drive wall 65 from the common electrode power supply section 86.

[0057] A partition groove 91 is formed on the first main surface 53A, separating the common electrode power supply section 86 from the individual electrode power supply section 89. The partition groove 91 is formed to a constant depth relative to the first main surface 53A. As a result, there is a portion of the individual electrode 88 where the width in the Z-axis direction is partially narrowed (see Figure 5(c)). Here, if the minimum width of the bypass wiring 95 is W1 and the minimum width of the individual electrode 88 in the portion where the partition groove 91 is provided is W2, then the relationship W1 ≥ W2 holds. The minimum width W2 of the individual electrode 88 is designed to have a wiring resistance such that the individual electrode 88 does not break due to the electrical load during driving (discharging). In other words, the bypass wiring 95 has a lower wiring resistance than the individual electrode 88, and is a width on the safe side.

[0058] Next, a method for manufacturing the head chip 50 including the actuator plate 53 will be described. Figure 6 is a flowchart showing the method for manufacturing the head chip 50 according to the first embodiment. For convenience, the following description will use the case where the head chip 50 is manufactured at the chip level as an example. The manufacturing method for the head chip 50 includes an actuator plate processing step S1, a cover plate joining step S2, a grinding step S3, a wiring formation step S4, a conductive material removal step S5, a processed film formation step S6, an intermediate plate joining step S7, a protective film formation step S8, and a nozzle plate joining step S9.

[0059] In actuator plate processing step S1, a disc-shaped dicer is inserted from above into the formation regions of the ejection channel 61 and non-ejection channel 62 of the actuator plate 53. In actuator plate processing step S1, the amount of travel of the dicer in the Y-axis direction is increased in the formation region of the non-ejection channel 62 compared to the formation region of the ejection channel 61. As a result, when viewed from the X-axis direction, the bottom surface of the ejection channel 61 is formed in a downwardly convex arc shape, and the bottom surface of the non-ejection channel 62 is formed in a straight line shape.

[0060] In the cover plate joining process S2, the cover plate 54 is attached to the upper surface of the actuator plate 53 via adhesive 70. This results in the cover plate 54 being laminated onto the actuator plate 53.

[0061] In grinding step S3, the lower surface of the actuator plate 53 is ground. Specifically, the actuator plate 53 is ground until the discharge channel 61 and non-discharge channel 62 open on the lower surface of the actuator plate 53. This forms the first main surface 53A on the actuator plate 53.

[0062] In the wiring formation step S4, drive wiring is formed by depositing electrode material onto the first main surface 53A of the actuator plate 53. In the wiring formation step S4, oblique deposition is performed on the first main surface 53A of the actuator plate 53 from the +X side and the -X side. As a result, an electrode film including a common electrode 85, a common electrode power supply section 86, individual electrodes 88, individual electrode power supply sections 89, and bypass wiring 95 is deposited on the lower surface of the actuator plate 53. In addition, the common electrode 85 is formed on the inner surface of the discharge channel 61, while the individual electrodes 88 are formed on the inner surface of the non-discharge channel 62.

[0063] In the conductive material removal step S5, unnecessary portions of the electrode film formed in the wiring formation step S4 are removed. Specifically, a laser is scanned across the first main surface 53A of the actuator plate 53 in the X-axis and Y-axis directions. For example, by removing the conductive material adhering to the area around the common electrode power supply section 86 of the actuator plate 53, the common electrode power supply section 86 is separated from the individual electrodes 88 and the bypass wiring 95. As a result, a blank area with laser irradiation marks is formed around the common electrode power supply section 86. After the conductive material removal step S5, a partition groove 91 is formed on the first main surface 53A of the actuator plate 53, thereby separating the common electrode power supply section 86 from the individual electrode power supply section 89.

[0064] In the processing film formation step S6, the laminate, which consists of the actuator plate 53 and the cover plate 54 stacked together, is immersed in a processing agent (silane coupling agent). As a result, a processing film 110 is formed on the lower surface of the actuator plate 53, the inner surfaces of each channel 61, 62, and the portion of the lower surface of the cover plate 54 that is exposed within each channel 61, 62.

[0065] The intermediate plate joining step S7 involves joining the intermediate plate 52 to the lower surface of the actuator plate 53. Specifically, adhesive 77 is applied to the lower surface of the actuator plate 53 via the treatment film 110, and then the intermediate plate 52 is joined via the adhesive 77.

[0066] In the protective film formation step S8, a protective film 120 is formed on the inner surfaces of each channel 61, 62, the lower surface of the intermediate plate 52, the inner surface of the communication hole 52a, and the lower surface of the cover plate 54, specifically on the parts exposed within each channel 61, 62. When a paraxylylene resin material is used as the protective film 120, the protective film 120 can be formed using, for example, chemical vapor deposition (CVD).

[0067] In nozzle plate joining step S9, the nozzle plate 51 is attached to the lower surface of the intermediate plate 52 via adhesive 78 while the nozzle hole 51a and the discharge channel 61 are aligned. Based on the above steps, the head tip 50 is manufactured.

[0068] Next, the operation when recording characters, graphics, etc., onto the recording medium P using the printer 1 shown in Figure 1 will be explained below. Assuming that printer 1 is initially configured with each ink tank 4 sufficiently filled with ink of a different color, the inkjet head 5 is filled with ink from the ink tanks 4 via the ink circulation mechanism 6.

[0069] Under these initial conditions, when printer 1 is activated, the recording medium P is held between the rollers 11 and 12 of transport mechanisms 2 and 3 and transported to the +X side. Simultaneously with the transport of the recording medium P, the carriage 29 moves in the Y-axis direction, causing the inkjet head 5 mounted on the carriage 29 to reciprocate in the Y-axis 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.

[0070] The movement of each inkjet head 5 is described in detail below. In a circulating side-chute type inkjet head 5 like the first embodiment, ink is first circulated through the circulation channel 23 by operating the pressure pump 24 and suction pump 25 shown in Figure 2. In this case, the ink circulating in the ink supply pipe 21 is supplied to each discharge channel 61 through the common inlet ink chamber 71 and the inlet slit 72, as shown in Figure 4. The ink supplied to each discharge channel 61 circulates through each discharge channel 61 in the Y-axis direction. After that, the ink is discharged to the common outlet ink chamber 75 through the outlet slit 76 and then returned to the ink tank 4 through the ink discharge pipe 22. This allows ink to be circulated between the inkjet head 5 and the ink tank 4.

[0071] 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 85 and the individual electrodes 88 via the flexible printed circuit board 92. At this time, the individual electrode 88 is set to a drive potential Vdd and the common electrode 85 is set to a reference potential GND, and a drive voltage is applied between each electrode 85, 88. As a result, an electric field is generated in the portion of each drive wall 65 sandwiched between the opposing regions, causing each drive wall 65 to bend and deform in a V-shape around its midpoint in the Z-axis direction. In other words, the drive wall 65 deforms in such a way that the volume of the ejection channel 61 expands.

[0072] After increasing the volume of each ejection channel 61, the voltage applied between the common electrode 85 and the individual electrodes 88 is reduced to zero. This causes the drive wall 65 to return to its original volume, and the volume of the ejection channel 61, which had been increased, returns to its original volume. As a result, the pressure inside the ejection channel 61 increases, and the ink is pressurized. Consequently, the ink is ejected in droplet form through the nozzle holes 51a. When the ink ejected from the nozzle holes 51a lands on the recording medium P, characters, images, etc., can be recorded on the recording medium P.

[0073] As described above, the head chip 50 according to this embodiment has an actuator plate 53 which has an ejection channel 61 (injection channel) filled with ink (liquid) and a non-ejection channel 62 (non-injection channel) which is not filled with ink, both extending in the Y-axis direction (first direction), and which is alternately formed in the X-axis direction (second direction) that intersects the Y-axis direction with the drive wall 65 in between, and an actuator plate 53 which has a common electrode 85 (first electrode) formed on the inner surface of the ejection channel 61 and an individual electrode 88 (second electrode) formed on the inner surface of the non-ejection channel 62, and the actuator On the first main surface 53A of the data plate 53, facing the -Z side (one side) of the Z axis direction (third direction) intersecting the Y axis direction and the X axis direction, there is an individual electrode power supply unit 89 (second electrode power supply unit) which is located on the -Y side (one side) that sandwiches the first opening 61A of the discharge channel 61 that opens on the first main surface 53A in the Y axis direction and supplies driving power to a pair of individual electrodes 88 that sandwich the discharge channel 61 in the X axis direction, and a bypass wiring 95 which is located on the +Y side (the other side) that sandwiches the first opening 61A in the Y axis direction and connects the pair of individual electrodes 88.

[0074] With this configuration, even if a break occurs in one of the pair of individual electrodes 88, power can be supplied from the individual electrode power supply unit 89 through the other individual electrode 88 that is not broken, and then through the bypass wiring 95 to the other individual electrode 88, thereby improving the reliability of the drive. Furthermore, since the bypass wiring 95 is formed on the first main surface 53A of the actuator plate 53, it can be formed simultaneously with other conductor patterns, thus suppressing cost increases and lead time increases due to the increased manufacturing process. Thus, according to this embodiment, non-conductivity due to disconnection of the individual electrodes 88 formed in the non-discharge channel 62 can be suppressed, thereby improving the reliability of the drive.

[0075] Furthermore, in this embodiment, the first main surface 53A is provided with a common electrode power supply section 86 formed in an annular shape along the opening edge of the first opening 61A and connected to the common electrode 85. When the shortest distance between the common electrode power supply section 86 and the bypass wiring 95 is D1, and the shortest distance between the common electrode power supply section 86 and the individual electrodes 88 is D2, the relationship D1 > D2 exists. With this configuration, by making the shortest distance between the common electrode power supply section 86 and the bypass wiring 95 greater than the shortest distance between the common electrode power supply section 86 and the individual electrodes 88, it is possible to suppress the occurrence of short circuits caused by ink being passed between the common electrode power supply section 86 and the bypass wiring 95, thereby improving the reliability of the drive.

[0076] Furthermore, in this embodiment, when the shortest distance between the common electrode power supply unit 86 and the bypass wiring 95 is D1, and the shortest distance between the common electrode 85 and the individual electrode 88 is D3, the relationship D1 ≥ D3 exists. With this configuration, by making the shortest distance between the common electrode power supply unit 86 and the bypass wiring 95 greater than or equal to the shortest distance between the common electrode 85 and the individual electrode 88 (i.e., the thickness of the drive wall 65), sufficient distance between the common electrode power supply unit 86 and the bypass wiring 95 can be secured, and the occurrence of a short circuit caused by ink being passed between the common electrode power supply unit 86 and the bypass wiring 95 can be suppressed more reliably.

[0077] Furthermore, in this embodiment, the first main surface 53A is provided with a common electrode power supply section 86 formed in an annular shape along the opening edge of the first opening 61A and connected to the common electrode 85, and a partition groove 91 (dividing groove) extending in the X-axis direction and separating the common electrode power supply section 86 from the individual electrode power supply section 89. When the minimum width of the bypass wiring 95 is W1 and the minimum width of the individual electrode 88 in the portion where the partition groove 91 is provided is W2, the relationship W1 ≥ W2 exists. With this configuration, since the minimum width of the bypass wiring 95 is greater than or equal to the minimum width of the individual electrode 88 in the portion where the partition groove 91 is provided, it is possible to suppress the wiring resistance in the bypass wiring 95 from becoming higher than in that portion. This prevents the bypass wiring 95 from being disconnected due to the electrical load during driving (discharging).

[0078] Furthermore, the inkjet head 5 (liquid ejection head) according to this embodiment is equipped with the head chip 50 described above. This configuration makes it possible to improve the reliability of the drive.

[0079] Furthermore, the printer 1 (liquid jet recording device) according to this embodiment is equipped with the inkjet head 5 described above. This configuration makes it possible to improve the reliability of the drive.

[0080] (Second Embodiment) Next, a second embodiment of the present invention will be described. In the following description, components identical or equivalent to those in the above-described embodiment will be denoted by the same reference numerals, and their descriptions will be simplified or omitted.

[0081] Figure 7 is a diagram showing the main components of the actuator plate 53 according to the second embodiment. As shown in Figure 7(c), the discharge channel 61 has a tapered section 61b in which the dimension in the Y-axis direction gradually decreases as it moves toward the -Z side (first main surface 53A side) in the Z-axis direction when viewed from the X-axis direction. The bypass wiring 95 of the second embodiment is formed intersecting the tapered section 61b when viewed from the Z-axis direction, as shown in Figure 7(b).

[0082] In the second embodiment, the bypass wiring 95 is provided intersecting the formation range of the cut-off portion 61b. By providing the bypass wiring 95 in this manner, it is possible to suppress the enlargement of the actuator plate 53 in the Y-axis direction (especially the +Y side) caused by adding the bypass wiring 95. In other words, it can contribute to miniaturization of the head chip 50.

[0083] (Third embodiment) Next, a third embodiment of the present invention will be described. In the following description, components identical or equivalent to those in the above-described embodiments will be denoted by the same reference numerals, and their descriptions will be simplified or omitted.

[0084] Figure 8 is a diagram showing the main components of the actuator plate 53 according to the third embodiment. In the third embodiment, as shown in Figures 8(a) and (b), the first main surface 53A is provided with a bypass groove 96 that extends linearly in the X-axis direction on the +Y side of the first opening 61A and the common electrode power supply section 86. A bypass wiring 95 is formed on the bottom surface of the bypass groove 96. The bypass wiring 95 may be formed on the side wall surface of the bypass groove 96, as long as it can connect to the pair of individual electrodes 88 that sandwich the discharge channel 61.

[0085] In the third embodiment, the bypass wiring 95 is formed in a bypass groove 96 provided to a certain depth in the first main surface 53A. By providing the bypass groove 96 in this way, the bypass wiring 95 is not formed on the same plane as the common electrode power supply section 86, and the occurrence of a short circuit caused by ink being spread between the common electrode power supply section 86 and the bypass wiring 95 can be reliably suppressed.

[0086] (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. In the following description, components identical or equivalent to those in the above-described embodiments will be denoted by the same reference numerals, and their descriptions will be simplified or omitted.

[0087] Figure 9 is a diagram showing the main components of the actuator plate 53 according to the fourth embodiment. In the fourth embodiment, as shown in Figures 9(a) and (c), the second main surface 53B is provided with a second bypass groove 98 that extends linearly in the X-axis direction on the -Y side of the second opening (upper end opening) of the discharge channel 61 that opens on the second main surface 53B and on the +Y side of the partition groove 91. A second bypass wiring 97 is formed on the bottom surface of the second bypass groove 98. The second bypass wiring 97 may be formed on the side wall surface of the second bypass groove 98, as long as it can connect to a pair of individual electrodes 88 that sandwich the discharge channel 61.

[0088] Thus, in the fourth embodiment, the second main surface 53B of the actuator plate 53 is provided with a second bypass wiring 97 that connects a pair of individual electrodes 88, positioned between the second opening of the discharge channel 61 that opens on the second main surface 53B and the partition groove 91 in the Y-axis direction. With this configuration, the risk of wire breakage in the partition groove 91 portion where the width of the individual electrodes 88 is narrowed can be avoided by the second bypass wiring 97. For example, in the individual electrodes 88, the portion indicated by reference numeral 88b has a higher risk of wire breakage than the portion indicated by reference numeral 88a. However, even if a wire breakage occurs in the portion indicated by reference numeral 88b, the pair of individual electrodes 88 are connected via the second bypass wiring 97 further back (+Y side) from that portion. Therefore, even if the bypass wiring 95 breaks, the reliability of the drive can be improved. Note that if a wire breakage occurs in the portion indicated by reference numeral 88a, the second bypass wiring 97 will not function, but the bypass wiring 95 will function and be able to connect the pair of individual electrodes 88. Incidentally, if a second bypass wiring 97 is to be provided, it will be necessary to additionally deposit an electrode film on the second main surface 53B.

[0089] 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, a fax machine or an on-demand printing machine may also be used. 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 P is paper was explained, but the configuration is not limited to this. The recording medium P 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.

[0090] In the embodiments described above, a configuration in which the Z-axis direction coincides with the direction of gravity was explained, but the configuration is not limited to this, and the Z-axis direction may also be aligned with the horizontal direction. In the embodiments described above, a configuration in which ink is ejected by deforming the actuator plate in a direction that expands the volume of the ejection channel by applying a voltage, and then restoring the actuator plate (so-called pull-type ejection), was explained, but the invention is not limited to this configuration. The head chip according to this disclosure may also be configured in a way that ejects ink by deforming the actuator plate in a direction that reduces the volume of the ejection channel by applying a voltage (so-called push-type ejection). When push-type ejection is performed, the actuator plate deforms so as to bulge outwards into the ejection channel when a drive voltage is applied. As a result, the volume inside the ejection channel decreases, the pressure inside the ejection channel increases, and the ink inside the ejection channel is ejected to the outside through the nozzle hole. When the drive voltage is reduced to zero, the actuator plate returns to its original state. As a result, the volume inside the ejection channel returns to its original state.

[0091] Furthermore, it is possible to replace the components in the embodiments described above with well-known components as appropriate, without departing from the spirit of this disclosure, and the modifications described above may be combined as appropriate. [Explanation of symbols]

[0092] 1. Printer (liquid jet recording device) 5. Inkjet head (liquid ejection head) 50 head tips 53 Actuator Plate 53A First Main Surface 53B Second Main Surface 61 Discharge Channel (Injection Channel) 61A 1st opening 61b Cut-off section 62 Non-discharge channels 61 Discharge Channel (Non-Injection Channel) 65 Drive Wall 85 Common electrode (1st electrode) 86 Common electrode power supply section (first electrode power supply section) 88 Individual electrode (second electrode) 89 Individual electrode power supply unit (second electrode power supply unit) 90 Tail 91 Divided trenches (divided trenches) 95 Bypass wiring 96 Bypass groove 97 Second bypass wiring 98 Second bypass groove

Claims

1. An actuator plate having injection channels filled with liquid and non-injection channels not filled with liquid, each extending in a first direction, and alternately formed in a second direction intersecting the first direction with a drive wall in between, A first electrode formed on the inner surface of the injection channel, The system comprises a second electrode formed on the inner surface of the non-injection channel, Of the actuator plate, the first main surface facing one side of the third direction intersecting the first and second directions is: A second electrode power supply unit is provided, which is located on one side of the injection channel that opens on the first main surface, sandwiching the injection channel in the first direction, and supplies driving power to a pair of second electrodes that sandwich the injection channel in the second direction. A bypass wiring is provided, which is located on the other side of the first opening in the first direction and connects the pair of second electrodes. Head tip.

2. The first main surface is provided with a first electrode power supply section, which is formed in an annular shape along the opening edge of the first opening and connected to the first electrode. When the shortest distance between the first electrode power supply unit and the bypass wiring is D1, and the shortest distance between the first electrode power supply unit and the second electrode is D2, D1 > D2 Having a relationship The head tip according to claim 1.

3. The first main surface is provided with a first electrode power supply section, which is formed in an annular shape along the opening edge of the first opening and connected to the first electrode. When the shortest distance between the first electrode power supply unit and the bypass wiring is D1, and the shortest distance between the first electrode and the second electrode is D3, D1 ≥ D3 Having a relationship The head tip according to claim 1 or 2.

4. The first main surface has, A first electrode power supply section is formed in an annular shape along the opening edge of the first opening and connected to the first electrode, A dividing groove is provided that extends in the second direction and separates the first electrode power supply section and the second electrode power supply section. When the minimum width of the bypass wiring is W1, and the minimum width of the second electrode in the portion where the dividing groove is provided is W2, W1 ≥ W2 Having a relationship The head tip according to claim 1 or 2.

5. The injection channel is provided with a tapered section in which the dimension in the first direction gradually decreases as viewed from the second direction toward one side of the third direction, The bypass wiring is formed to intersect the raised section when viewed from the third direction. The head tip according to claim 1 or 2.

6. The first main surface has, A first electrode power supply section is formed in an annular shape along the opening edge of the first opening and connected to the first electrode, On the other side of the first opening, which is sandwiched in the first direction, a bypass groove extending in the second direction is provided, The bypass wiring is formed in the bypass groove, The head tip according to claim 1 or 2.

7. The first main surface has, A first electrode power supply section is formed in an annular shape along the opening edge of the first opening and connected to the first electrode, A dividing groove is provided that extends in the second direction and separates the first electrode power supply section and the second electrode power supply section. Of the actuator plate, the second main surface facing the other side in the third direction is: In the first direction, a second bypass wiring is provided, which is positioned between the second opening of the injection channel that opens on the second main surface and the dividing groove, extends in the second direction, and connects the pair of second electrodes. The head tip according to claim 1 or 2.

8. A liquid spray head comprising the head tip described in claim 1 or 2.

9. A liquid injection recording device comprising the liquid injection head described in claim 8.

Images