Inkjet head

Abstract

This inkjet head is provided with: a head body having a plurality of nozzle holes that are arranged on a line and eject ink, a plurality of ink chambers that are in communication with the plurality of nozzle holes, respectively, and a vibration plate that vibrates to pressurize the ink inside the plurality of ink chambers; and a plurality of piezoelectric element units that have piezoelectric elements to vibrate the vibration plate, are arranged zigzag along the line with the line held therebetween, and are bonded to the vibration plate.

Description

[Technical Field]

[0001] The present disclosure relates to an inkjet head. [Background technology]

[0002] One example of conventional inkjet head technology is disclosed in Patent Document 1. When printing on an object whose width is wider than the width of the inkjet head, the inkjet head makes multiple reciprocating movements. According to Patent Document 1, by arranging multiple inkjet heads in a staggered pattern on a substrate, the number of reciprocating movements of the substrate and, therefore, the inkjet heads can be reduced. Furthermore, by adjusting the spacing between inkjet heads on the substrate, the nozzle pitch can be adjusted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-90686 Summary of the Invention

[0004] An inkjet head according to one aspect of the present disclosure includes a head body having a plurality of nozzle holes arranged in a straight line and ejecting ink, a plurality of ink chambers respectively communicating with the plurality of nozzle holes, and a vibration plate that vibrates to pressurize the ink in the plurality of ink chambers; and a plurality of piezoelectric element units that have piezoelectric elements that vibrate the vibration plate and are arranged in a zigzag pattern along the straight line and joined to the vibration plate. The plurality of piezoelectric elements corresponding to the plurality of ink chambers are connected to each other and integrated. . In addition, an inkjet head according to one aspect of the present disclosure comprises a head body having a plurality of nozzle holes arranged in a straight line and ejecting ink, a plurality of ink chambers each connected to the plurality of nozzle holes, and a vibration plate that vibrates to pressurize the ink in the plurality of ink chambers; and a plurality of piezoelectric element units having piezoelectric elements that vibrate the vibration plate, and arranged in a zigzag pattern along the straight line and sandwiched between the straight line and joined to the vibration plate, wherein the plurality of ink chambers are divided into a plurality of groups of ink chambers, and each of the plurality of groups of ink chambers is arranged in a zigzag pattern along the straight line and sandwiched between the straight line so as to correspond to one of the plurality of piezoelectric element units. Furthermore, an inkjet head according to one aspect of the present disclosure comprises a head body having a plurality of nozzle holes arranged in a straight line and ejecting ink, a plurality of ink chambers each connected to the plurality of nozzle holes, and a vibration plate that vibrates to pressurize the ink in the plurality of ink chambers; and a plurality of piezoelectric element units having piezoelectric elements that vibrate the vibration plate, and arranged in a zigzag pattern along the straight line and sandwiched between the straight line and joined to the vibration plate, wherein the plurality of ink chambers are arranged in a zigzag pattern along the straight line and sandwiched between the straight line to correspond to the plurality of piezoelectric element units, and the head body further has a plurality of discharge paths that discharge ink from the plurality of ink chambers, the plurality of discharge paths being arranged in a zigzag pattern along the straight line and sandwiched between the straight line, and each of the plurality of discharge paths is connected to a plurality of ink chambers arranged on the opposite side of the straight line. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a top view of an inkjet head according to a first embodiment of the present disclosure; [Figure 2] Cross-sectional view of the inkjet head taken along line II-II in Figure 1. [Figure 3] Cross-sectional view of the inkjet head taken along line III-III in Figure 1. [Figure 4] FIG. 10 is a diagram showing the operation of an inkjet head when changing the nozzle pitch. [Figure 5] FIG. 10 is a top view of an inkjet head according to a second embodiment of the present disclosure. [Figure 6] Cross-sectional view of the inkjet head taken along line VI-VI in Figure 5. [Figure 7] Cross-sectional view of the inkjet head taken along line VII-VII in Figure 5. DETAILED DESCRIPTION OF THE INVENTION

[0006] Inkjet heads are increasingly being used in the production of semiconductor devices. To improve production efficiency, there is a demand for longer printing widths and variable nozzle pitches. Variable nozzle pitches can be achieved, for example, by arranging the nozzles in a straight line and tilting the inkjet head relative to the scanning direction.

[0007] However, when a plurality of inkjet heads are arranged in a staggered pattern as disclosed in Patent Document 1, it is not possible to obtain a desired nozzle pitch even if the substrate is tilted.

[0008] Furthermore, when the inkjet head is lengthened to increase the printing width by arranging the nozzles in a straight line, it is difficult to lengthen the piezoelectric elements used in the actuators for ejecting ink due to their characteristics. Also, due to differences in the linear expansion coefficients of the components that make up the inkjet head, temperature changes cause variations in internal stress, which in turn causes distortion, affecting the nozzle pitch.

[0009] The present disclosure is intended to solve the above-mentioned problems, and aims to suppress distortion caused by temperature changes even when an inkjet head is made longer.

[0010] First Embodiment An inkjet head according to a first embodiment of the present disclosure will be described below with reference to the drawings. In the following description, six directions are used: right, left, front, rear, top, and bottom. Each direction is shown in FIGS. 1 to 3.

[0011] The inkjet head 1 ejects ink to print on an object. The ink is printing ink. In addition to printing ink, the ink may be a liquid material such as solder paste, silver paste, stamping paste, phosphor paste, or a cell suspension.

[0012] The inkjet head 1 ejects ink by controlling a piezoelectric element (described later) with a control device (not shown). The inkjet head 1 is configured so that ink circulates between the inkjet head 1 and a liquid delivery device (not shown). That is, the liquid delivery device supplies ink to the inkjet head 1, and also discharges ink that has not been ejected from the inkjet head 1.

[0013] As shown in FIGS. 1 to 3, the inkjet head 1 includes a head main body 10, a piezoelectric element unit 20, and a housing member 30.

[0014] The head main body 10 is formed in a rectangular parallelepiped shape and is configured by stacking a nozzle plate 11, an ink chamber plate 12, and a vibration plate 13. The nozzle plate 11, the ink chamber plate 12, and the vibration plate 13 are bonded together by, for example, an adhesive.

[0015] The nozzle plate 11 is formed in a plate shape from an alloy steel such as stainless steel. The nozzle plate 11 has a plurality of nozzle holes 11a that are arranged on a straight line L and eject ink. The straight line L is an imaginary line that extends in the left-right direction. The number of nozzle holes 11a is 36, but it goes without saying that the number is not limited to this.

[0016] The ink chamber plate 12 is formed into a rectangular parallelepiped shape by, for example, bonding stainless steel plates formed by etching or pressing with an adhesive. The ink chamber plate 12 has multiple sets of supply channels 12a, ink chambers 12b, silos 12c, and discharge channels 12d. The multiple sets are configured to correspond to the multiple nozzle holes 11a. In other words, the number of sets is 36, the same as the number of nozzle holes 11a, but it goes without saying that it is not limited to this.

[0017] The supply path 12a is formed to extend along the front-rear direction and supplies ink to the ink chamber 12b.

[0018] The ink chamber 12b is formed in a rectangular parallelepiped shape extending in the front-rear direction, and is connected to the supply channel 12a and the silo 12c. The upper wall of the ink chamber 12b is formed by a vibration plate 13.

[0019] The silos 12c are formed to extend in the vertical direction and are connected to the ink chambers 12b and the discharge channels 12d. The silos 12c are also formed to be connected to the nozzle holes 11a. That is, each of the ink chambers 12b communicates with a corresponding one of the nozzle holes 11a via a corresponding one of the silos 12c.

[0020] The discharge path 12d is formed to extend in the front-rear direction and is connected to the silo 12c. The discharge path 12d communicates with the ink chamber 12b via the silo 12c, and discharges ink from the ink chamber 12b.

[0021] The plurality of sets are divided into a plurality of groups. There are four groups. That is, each of the plurality of groups has nine sets. It goes without saying that the number of groups is not limited to four. Each of the plurality of groups has one supply connection path 12e and one discharge connection path 12f.

[0022] The supply connection 12e is connected to each of the supply passages 12a in one of the groups, and the discharge connection 12f is connected to each of the discharge passages 12d in one of the groups.

[0023] The multiple groups are arranged in a zigzag pattern along a straight line L, with the straight line L in between (FIG. 1). That is, the nine supply channels 12a, ink chambers 12b, silos 12c, and discharge channels 12d that make up one group are arranged as a single unit along the straight line L, with the straight line L in between.

[0024] By arranging the plurality of groups in this manner, in the plurality of sets, the supply connection path 12e, the supply path 12a, and the ink chamber 12b are arranged on the opposite side of the straight line L from the discharge path 12d and the discharge connection path 12f. Also, the plurality of discharge paths 12d are each connected to the plurality of ink chambers 12b arranged on the opposite side of the straight line L. The plurality of supply paths 12a are each connected to the plurality of ink chambers 12b arranged on the same side as viewed from the straight line L.

[0025] Similarly, the supply connection path 12e and the discharge connection path 12f are also arranged in a zigzag pattern along the straight line L. FIG. 2 is a cross-sectional view of a portion where the ink chamber 12b is located in front of the straight line L. FIG. 3 is a cross-sectional view of a portion where the ink chamber 12b is located in back of the straight line L.

[0026] The vibration plate 13 vibrates to pressurize the ink in the ink chambers 12b. The vibration plate 13 is formed in the shape of a single plate and is arranged to cover the ink chambers 12b. The vibration plate 13 is made of an alloy of nickel and cobalt, nickel, or the like. The vibration plate 13 has a plurality of vibration plates 13a bonded to it by, for example, an adhesive so as to correspond to the ink chambers 12b.

[0027] A plurality of piezoelectric element units 20 are arranged to correspond to the plurality of groups. The number of piezoelectric element units 20 is four, but it goes without saying that the number is not limited to this.

[0028] Each of the plurality of piezoelectric element units 20 has a plurality of piezoelectric elements 20a corresponding to the plurality of sets constituting one of the plurality of groups. The number of piezoelectric elements 20a in each piezoelectric element unit 20 is nine, but it goes without saying that this is not limited to this. The piezoelectric elements 20a are formed in a rectangular parallelepiped shape.

[0029] The piezoelectric element unit 20 is formed by combining a plurality of piezoelectric elements 20a. The piezoelectric element unit 20 is formed in a comb shape such that the plurality of piezoelectric elements 20a are connected to each other at their upper ends. The lower ends of the piezoelectric elements 20a are bonded to the vibration plate 13a, for example, with an adhesive. The piezoelectric elements 20a are deformed when a voltage is applied, causing the vibration plate 13a and therefore the vibration plate 13 to vibrate. The piezoelectric element unit 20 is formed in a rectangular parallelepiped shape and includes electrodes (not shown) that apply a voltage to the piezoelectric elements 20a, and is bonded to the vibration plate 13, for example, with an adhesive.

[0030] Furthermore, the plurality of piezoelectric element units 20 are arranged in a zigzag pattern along the straight line L, with the straight line L in between. Specifically, the plurality of piezoelectric element units 20 are arranged in a zigzag pattern along the straight line L, with the straight line L in between, so as to correspond to the plurality of ink chambers 12b. Conversely, the plurality of ink chambers 12b are arranged in a zigzag pattern along the straight line L, with the straight line L in between, so as to correspond to the plurality of piezoelectric element units 20.

[0031] The multiple piezoelectric element units 20 are arranged in a zigzag pattern along the line L, sandwiching the line L. Therefore, the multiple piezoelectric element units 20 include two or more first piezoelectric element units and two or more second piezoelectric element units located opposite the two or more first piezoelectric element units with respect to the line L. The two or more first piezoelectric element units are arranged at a first interval in a direction parallel to the line L. The two or more second piezoelectric element units are arranged at a second interval in a direction parallel to the line L. The second interval may be the same as the first interval. The two or more second piezoelectric element units have an offset with respect to the two or more first piezoelectric element units in a direction parallel to the line L. The offset may be half the length of the first interval. The two or more first piezoelectric element units may each be separated by a first distance from the line L in a direction perpendicular to the line L. The two or more second piezoelectric element units may each be separated by a second distance from the line L in a direction perpendicular to the line L. The second distance may be the same as the first distance.

[0032] Furthermore, one of the plurality of piezoelectric element units 20 is arranged so as to partially face another of the plurality of piezoelectric element units 20 in a direction perpendicular to the straight line L. Specifically, the right and left sides of the piezoelectric element unit 20 arranged in front of the straight line L face the left and right sides of the piezoelectric element unit 20 arranged behind the straight line L, respectively.

[0033] The housing member 30 is made of alloy steel such as stainless steel and has a rectangular frame shape when viewed from above. The housing member 30 is joined to the upper surface of the head main body 10, for example, by adhesive. The housing member 30 has a common supply path 31, a plurality of second discharge connection paths 32, and a common discharge path 33. The common supply path 31, the plurality of second discharge connection paths 32, and the common discharge path 33 are arranged on both sides of a straight line L.

[0034] The common supply path 31 is formed on the underside of the housing member 30 so as to extend in a direction along the straight line L, and is connected to each of the plurality of supply connection paths 12e. Specifically, the common supply path 31 disposed in front of the straight line L is connected to each of the plurality of supply connection paths 12e located in front of the straight line L. Furthermore, the common supply path 31 disposed behind the straight line L is connected to each of the plurality of supply connection paths 12e located behind the straight line L. The common supply path 31 is connected to the liquid delivery device via supply piping 40 connected to the housing member 30.

[0035] The plurality of second discharge connection paths 32 are provided so as to connect to the common discharge path 33 and the discharge connection paths 12f in one of the plurality of groups, respectively.

[0036] The common discharge path 33 is formed on the upper side of the housing member 30 so as to extend in a direction along the straight line L, and is connected to each of the plurality of discharge connection paths 12f via the second discharge connection paths 32. Specifically, the common discharge path 33 disposed forward as viewed from the straight line L is connected to each of the plurality of discharge connection paths 12f located forward as viewed from the straight line L via the second discharge connection paths 32. Furthermore, the common discharge path 33 disposed rearward as viewed from the straight line L is connected to each of the plurality of discharge connection paths 12f located rearward as viewed from the straight line L via the second discharge connection paths 32. The common discharge path 33 is connected to the liquid delivery device via a discharge pipe 50 connected to the housing member 30.

[0037] In addition, in the head main body 10, the linear expansion coefficients of the nozzle plate 11, the ink chamber plate 12, and the housing member 30 are different from the linear expansion coefficients of the vibration plate 13 and the piezoelectric element unit 20. In addition, the linear expansion coefficients of the nozzle plate 11, the ink chamber plate 12, the housing member 30, and the vibration plate 13 are greater than the linear expansion coefficient of the piezoelectric element unit 20.

[0038] Specifically, the linear expansion coefficients of the nozzle plate 11, ink chamber plate 12, and housing member 30 are approximately 10 to 18×10 / °C. The linear expansion coefficient of the vibration plate 13 is approximately 13 to 15×10 / °C. The linear expansion coefficient of the piezoelectric element unit 20 is approximately 2 to 4×10 / °C. It goes without saying that the materials and linear expansion coefficients of the members constituting the inkjet head 1 are not limited to those described above.

[0039] As described above, the components constituting the inkjet head 1 have different linear expansion coefficients, and therefore, the amount of deformation caused by, for example, a change in ambient temperature varies. Furthermore, the components constituting the inkjet head 1 are joined as described above. Therefore, variations in internal stress and, ultimately, distortion occur in the head body 10.

[0040] As described above, even if the linear expansion coefficients differ between the components that make up the inkjet head 1, the multiple piezoelectric element units 20 are arranged in a zigzag pattern along the straight line L, with the straight line L on either side, thereby suppressing variations in internal stress in the head body 10 and, ultimately, distortion.

[0041] For example, consider a comparative inkjet head 1 in which all of the piezoelectric element units 20 are arranged only forward as viewed from the line L, in a direction along the line L. In this case, all of the ink chambers 12b are arranged so as to be located forward as viewed from the line L.

[0042] As described above, the linear expansion coefficient of the piezoelectric element unit 20 is smaller than the linear expansion coefficients of the nozzle plate 11, the ink chamber plate 12, and the vibration plate 13. Therefore, when the ambient temperature rises, internal stress occurs due to the difference in linear expansion coefficients in the area of ​​the head body 10 forward of the line L where the piezoelectric element unit 20 is arranged.

[0043] On the other hand, no piezoelectric element unit 20 is disposed in the area of ​​the head body 10 that is rearward as viewed from the line L. In other words, the internal stress generated in the area of ​​the head body 10 that is rearward as viewed from the line L is smaller than the internal stress generated in the area of ​​the head body 10 that is forward as viewed from the line L. Therefore, in the head body 10, there is a difference between the internal stresses generated in the areas on both sides of the line L, i.e., there is a variation in the internal stress. This causes distortion in the head body 10, which affects the nozzle pitch.

[0044] On the other hand, in the inkjet head 1 of the first embodiment, as described above, the piezoelectric element units 20 are arranged in a zigzag pattern along the straight line L, with the straight line L in between. Furthermore, the internal stresses generated in the head main body 10 at each location where the plurality of piezoelectric element units 20 are arranged are of the same magnitude. Therefore, the variation in the internal stress generated in the head main body 10 is smaller than in the inkjet head 1 of the comparative example. In other words, the distortion generated in the inkjet head 1 of the first embodiment, and therefore the effect on the nozzle pitch, is suppressed compared to the inkjet head 1 of the comparative example.

[0045] Furthermore, as described above, one of the plurality of piezoelectric element units 20 is arranged so as to partially face another one of the plurality of piezoelectric element units 20 in the direction perpendicular to the straight line L. This makes the distance between adjacent piezoelectric element units 20 in the direction along the straight line L smaller than when one of the plurality of piezoelectric element units 20 does not partially face another one of the plurality of piezoelectric element units 20 in the direction perpendicular to the straight line L.

[0046] Therefore, in the head main body 10, the difference between the internal stress generated in the portion where the piezoelectric element unit 20 is arranged and the internal stress generated in the portion where the piezoelectric element unit 20 is not arranged, i.e., the variation in internal stress, is reduced. Therefore, the distortion generated in the head main body 10 and the influence on the nozzle pitch are reduced. Note that one of the multiple piezoelectric element units 20 may be arranged so as not to partially face another of the multiple piezoelectric element units 20 in the direction perpendicular to the line L.

[0047] Next, we will explain the operation of the inkjet head 1. Ink is supplied from the liquid delivery device to the common supply channel 31 via the supply pipe 40. The ink supplied to the common supply channel 31 is diverted to the multiple supply channels 12a via the multiple groups of supply connection channels 12e.

[0048] In each of the groups, the ink flows through the supply channel 12a, ink chamber 12b, silo 12c, and discharge channel 12d, and then joins together at the discharge connection channel 12f. The ink that has flowed through one of the groups is discharged from the discharge connection channel 12f through the second discharge connection channel 32 to the common discharge channel 33, where it joins with the ink that has flowed through another of the groups. The ink is then discharged from the common discharge channel 33 through the discharge piping 50 to the liquid delivery device.

[0049] When the piezoelectric element 20a is energized while ink is circulating between the liquid delivery device and the inkjet head 1 as described above, the vibration plate 13a and, ultimately, the vibration plate 13 vibrate in response to the deformation of the piezoelectric element 20a. The vibration of the vibration plate 13 pressurizes the ink in the ink chamber 12b, causing the ink to be ejected from the nozzle hole 11a. As a result, the ink is printed on an object passing below the inkjet head 1.

[0050] Furthermore, since the nozzle holes 11a are arranged on a straight line L, the nozzle pitch can be changed with respect to the traveling direction F of the object by tilting the inkjet head 1 with respect to the traveling direction F, as shown in FIG.

[0051] As described above, in the inkjet head 1, the plurality of piezoelectric element units 20 are arranged in a zigzag pattern along the straight line L, with the straight line L in between. Also, the ink chambers 12b, and in turn the supply connection path 12e, the supply path 12a, the silo 12c, the discharge path 12d, the discharge connection path 12f, and the second discharge connection path 32 are arranged in a zigzag pattern along the straight line L, corresponding to the piezoelectric element units 20. Therefore, the piezoelectric element units 20 and the discharge connection paths 12f are alternately arranged along the straight line L. This allows the head main body 10 to be configured efficiently and compactly.

[0052] Furthermore, in the housing member 30, as described above, the common supply path 31 and the common discharge path 33 are arranged on either side of the head main body 10 across the straight line L. This allows the head main body 10 to be configured even more efficiently.

[0053] Second Embodiment Next, an inkjet head 1 according to a second embodiment of the present disclosure will be described, focusing mainly on the differences from the first embodiment. As shown in Fig. 5, the inkjet head 1 according to the second embodiment includes a plurality of vibration plates 113 corresponding to the plurality of groups. In the second embodiment, the number of vibration plates 113 is four, but it goes without saying that the number is not limited to four.

[0054] The vibration plate 113 is formed by electroforming, including a photolithography process, using a nickel-cobalt alloy, a nickel-palladium alloy, or nickel. In other words, the vibration plate 113 is a metal thin film formed using a metal. Because the manufacturing process for the vibration plate 113 includes a photolithography process, the outer shape of the vibration plate 113 can be formed with high precision. Furthermore, when multiple vibration plates 13a are formed by a photolithography process and bonded to the vibration plate 113, the outer shape precision of the vibration plates 13a and the positional precision of the vibration plates 13a relative to the vibration plate 113 are improved. This improves the positional precision of the vibration plates 13a relative to the piezoelectric element 20a, and ultimately the positional precision of the vibration plate 113 relative to the piezoelectric element unit 20. Therefore, the multiple vibration plates 113 can be arranged without interfering with each other. Furthermore, because the vibration plate 113 is a metal thin film, it has good responsiveness to deformation of the piezoelectric element 20a.

[0055] Furthermore, the vibration plate 113 of the second embodiment is smaller than the vibration plate 13 of the first embodiment. Therefore, when the ambient temperature changes, the amount of deformation of each vibration plate 113 of the second embodiment is smaller than the amount of deformation of the vibration plate 13 of the first embodiment. Therefore, the magnitude of the internal stress of the head body 10 of the second embodiment is smaller than the magnitude of the internal stress of the head body 10 of the first embodiment. In other words, by forming a plurality of vibration plates 113, it is possible to reduce the variation in the internal stress of the head body 10, and therefore the distortion.

[0056] The multiple vibration plates 113 are arranged in a zigzag pattern along the straight line L on either side of the straight line L so as to correspond to the piezoelectric element units 20. Therefore, similar to the arrangement of the multiple piezoelectric element units 20 described above, the multiple vibration plates 113 of the second embodiment can reduce the variation in internal stress of the head body 10, and therefore the distortion.

[0057] Moreover, one of the plurality of vibration plates 113 is arranged so as to partially face another of the plurality of vibration plates 113 in the direction along the straight line L. Furthermore, one of the plurality of vibration plates 113 is arranged so as to partially face another of the plurality of vibration plates 113 in the direction perpendicular to the straight line L.

[0058] Therefore, the distance between the multiple vibration plates 113 in the second embodiment is smaller than when one of the multiple vibration plates 113 does not partially face another one of the multiple vibration plates 113. In other words, similar to the arrangement of the multiple piezoelectric element units 20 described above, it is possible to reduce the variation in internal stress of the head body 10 and, therefore, the distortion.

[0059] Specifically, the plurality of vibration plates 113 are arranged such that the corners located on the side of the straight line L are chamfered and the corners of the plurality of vibration plates 113 that are diagonally adjacent to each other face each other. Note that one of the plurality of vibration plates 113 may be arranged so as not to partially face another one of the plurality of vibration plates 113 in the direction perpendicular to the straight line L or in the direction along the straight line L.

[0060] 6 and 7, in the ink chamber plate 12, the ink chamber 12b is disposed away from the nozzle hole 11a in the direction perpendicular to the line L. This allows the ink chamber 12b of the second embodiment to be formed smaller than the ink chamber 12b of the first embodiment. Therefore, the vibration plate 113 that forms the upper wall of the ink chamber 12b can be made smaller, and multiple vibration plates 113 can be arranged so as not to interfere with each other.

[0061] Furthermore, the ink chambers 12b and the silos 12c are connected via intermediate flow paths 112g in the ink chamber plate 12. This increases the distance between the ink chambers 12b via the discharge connection paths 12f compared to the first embodiment, thereby suppressing the effects of pressure fluctuations between the ink chambers 12b.

[0062] According to the inkjet head of the present disclosure, even when the inkjet head is made long, distortion caused by temperature changes can be suppressed.

[0063] The present disclosure is not limited to the embodiments described above, and various modifications to the present embodiments and combinations of components from different embodiments are also included within the scope of the present disclosure, as long as they do not deviate from the gist of the present disclosure. [Industrial Applicability]

[0064] The present invention is widely applicable to inkjet heads. [Explanation of symbols]

[0065] 1 Inkjet head 10 Head body 11 Nozzle plate 11a Nozzle hole 12 Ink chamber plate 12a Supply route 12b ink chamber 12d Exhaust channel 13 Vibration Plate 13a diaphragm 20 Piezoelectric element unit 20a Piezoelectric element 30 Housing member 31 Common supply route 33 Common discharge path L straight line

Claims

1. a head body having a plurality of nozzle holes arranged in a line and ejecting ink, a plurality of ink chambers respectively communicating with the plurality of nozzle holes, and a vibration plate that vibrates to pressurize the ink in the plurality of ink chambers; a plurality of piezoelectric element units each having a piezoelectric element that vibrates the vibration plate, the piezoelectric element units being arranged along the straight line in a zigzag pattern on either side of the straight line and joined to the vibration plate; The plurality of piezoelectric elements corresponding to the plurality of ink chambers are connected to each other and integrated. Inkjet head.

2. A head body having a plurality of nozzle holes arranged in a straight line for ejecting ink, a plurality of ink chambers each communicating with the plurality of nozzle holes, and a vibration plate that vibrates to pressurize the ink in the plurality of ink chambers; a plurality of piezoelectric element units each having a piezoelectric element that vibrates the vibration plate, the piezoelectric element units being arranged along the straight line in a zigzag pattern on either side of the straight line and joined to the vibration plate; the plurality of ink chambers are divided into a plurality of ink chamber groups, and each of the plurality of ink chamber groups is arranged in a zigzag pattern along the straight line so as to correspond to one of the plurality of piezoelectric element units; Inkjet head.

3. A head body having a plurality of nozzle holes arranged in a straight line for ejecting ink, a plurality of ink chambers each communicating with the plurality of nozzle holes, and a vibration plate that vibrates to pressurize the ink in the plurality of ink chambers; a plurality of piezoelectric element units each having a piezoelectric element that vibrates the vibration plate, the piezoelectric element units being arranged along the straight line in a zigzag pattern on either side of the straight line and joined to the vibration plate; the ink chambers are arranged in a zigzag pattern along the straight line so as to correspond to the piezoelectric element units, the head body further includes a plurality of discharge paths for discharging the ink from the plurality of ink chambers; the plurality of discharge paths are arranged along the straight line in a zigzag pattern on either side of the straight line, The plurality of discharge paths are respectively connected to the plurality of ink chambers arranged on opposite sides of the straight line. Inkjet head.

4. The head body is configured by laminating a nozzle plate in which the plurality of nozzle holes are formed, an ink chamber plate in which the plurality of ink chambers are formed, and the vibration plate. The ink jet head according to claim 1 .

5. one of the plurality of piezoelectric element units is disposed so as to partially face another of the plurality of piezoelectric element units in a direction perpendicular to the straight line; The ink jet head according to claim 1 .

6. A plurality of the vibration plates are provided, the vibration plates are arranged along the straight line in a zigzag pattern on either side of the straight line so as to correspond to the piezoelectric element units; The ink jet head according to claim 1 .

7. one of the plurality of vibration plates is disposed so as to partially face another of the plurality of vibration plates in a direction along the straight line; 7. The ink jet head according to claim 6.

8. one of the plurality of vibration plates is disposed so as to partially face another of the plurality of vibration plates in a direction perpendicular to the straight line; 8. The ink jet head according to claim 6 or 7.

9. the ink chambers are spaced apart from the nozzle holes in a direction perpendicular to the straight line; The ink jet head according to claim 1 .

10. a linear expansion coefficient of a portion of the head body that constitutes the plurality of nozzle holes and the plurality of ink chambers is different from a linear expansion coefficient of the vibration plate and the plurality of piezoelectric element units; The ink jet head according to claim 1 .

11. a linear expansion coefficient of the vibration plate and a linear expansion coefficient of the nozzle holes and ink chambers in the head body are greater than a linear expansion coefficient of the piezoelectric element units; The ink jet head according to claim 1 .

12. a housing member joined to the head body and having a common discharge channel through which the ink discharged from the plurality of discharge channels is joined and discharged; 4. The ink jet head according to claim 3.

13. the head body further includes a plurality of supply paths for supplying ink to the plurality of ink chambers; the plurality of supply paths are arranged along the straight line in a zigzag pattern on either side of the straight line, the plurality of supply paths are respectively connected to the plurality of ink chambers that are arranged on the same side as viewed from the straight line; The ink jet head according to claim 12.

14. the housing member further includes a common supply channel that divides the ink and supplies it to the plurality of supply channels; the common discharge path and the common supply path are disposed on both sides of the straight line in a direction perpendicular to the straight line, The ink jet head according to claim 13.

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