JP3915412B2 - Inkjet printer head and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet print head, and more particularly to an ink jet printer head capable of easily grasping the position of an electrode arrangement that has shifted in a manufacturing process of a piezoelectric actuator, and a method of manufacturing the same.
[0002]
[Prior art]
A prior art on-demand type piezoelectric ink jet printer head includes a cavity plate having a plurality of nozzles and a pressure chamber for each nozzle, as described in JP-A-4-341851, and each pressure chamber. The plate-type piezoelectric actuator is formed by sandwiching a piezoelectric sheet with a formed flat individual electrode and a common electrode common to a plurality of adjacent pressure chambers, and the piezoelectric actuator is connected to the cavity plate. Each of the individual electrodes is stacked so as to correspond to each pressure chamber.
[0003]
The piezoelectric actuator in the ink jet printer head configured as described above is configured such that the end of each individual electrode is pulled out to the edge of the piezoelectric sheet and is electrically connected to at least the end of each individual electrode on the side surface in the stacking direction. The electrodes are formed by metal vacuum deposition, sputtering, or application of a conductive paste, and connected to the outside via the side electrodes.
[0004]
In addition, as a configuration in which the common electrodes and the individual electrodes in the piezoelectric actuator are electrically connected to each other in the stacking direction, through-holes penetrating in the thickness direction of the piezoelectric sheet are provided corresponding to the positions where the respective electrodes are provided. It has been proposed to fill each hole with a conductive paste to sequentially connect individual electrodes or common electrodes in the stacking direction and lead them to the surface of the piezoelectric actuator.
[0005]
[Problems to be solved by the invention]
However, as conventionally known, the piezoelectric sheet contracts when sintered, and the pitch of the individual electrodes is reduced. For this reason, a green sheet to be a piezoelectric sheet is manufactured in anticipation of shrinkage. However, the shrinkage varies between the central portion and the peripheral portion of the green sheet, and the shrinkage varies depending on the position in the sintering furnace. Therefore, if the piezoelectric actuator and the cavity plate made of a metal material or the like are arbitrarily combined, the pitch of the individual electrodes and the pitch of the pressure chambers of the cavity plate may not match.
[0006]
For this reason, the pitch of the individual electrodes must be measured after the above-mentioned sintering, and a piezoelectric actuator that matches the pressure chamber pitch of the cavity plate must be combined with the cavity plate. However, in the piezoelectric actuator having the above-described through holes, the individual electrodes cannot be seen from the outside, and therefore the pitch cannot be measured. The end of the through hole is exposed on the surface, but because it is located in the periphery of the piezoelectric actuator, the amount of contraction may differ from the location where the individual electrode is located. Even if it is used for measurement, it is difficult to accurately grasp the pitch of the individual electrodes.
[0007]
As described above, in the case where the side electrode is formed on the side surface of the piezoelectric actuator, the end of the individual electrode is exposed on the side surface before the side electrode is formed. Since the thickness of the electrode exposed on the side surface in the stacking direction is small, it is difficult to measure. Moreover, as described above, since this position is the peripheral portion of the piezoelectric actuator, the contraction amount is different from the position where the main part of the individual electrode is located, and it is difficult to accurately grasp the pitch of the individual electrode.
[0008]
The present invention has been made to solve the above-described problems, and provides an inkjet printer head capable of easily grasping the position of an electrode arrangement that has shifted in the manufacturing process of a piezoelectric actuator, and a manufacturing method thereof. The purpose is to do.
[0009]
[Means for Solving the Problems]
In order to achieve this object, an ink jet printer head according to claim 1 includes a cavity plate having a plurality of nozzles and pressure chambers for each of the plurality of nozzles, and a plurality of correspondingly provided pressure chambers. The internal electrodes are sandwiched between piezoelectric sheets and laminated, and the surface is connected to each internal electrode and external control is performed. circuit And a plate-type piezoelectric actuator having a plurality of surface electrodes connectable to a wiring member extending from the surface, and the surface of the piezoelectric actuator is disposed at a position spaced from the surface electrode. The mark which shows a position is given.
[0010]
According to the ink jet printer head of the first aspect, when a voltage is applied to an arbitrary internal electrode among the plurality of internal electrodes, distortion in the stacking direction due to the piezoelectric occurs. Due to the pressure caused by this distortion, the internal volume of the pressure chamber corresponding to the internal electrode is reduced, so that ink in the pressure chamber is ejected from the nozzles in the form of droplets and printing is performed on the paper. Therefore, the internal electrodes provided in the piezoelectric actuator and the pressure chambers provided in the cavity plate must be laminated in correspondence with each other, but the internal electrodes are displaced due to sintering in the manufacturing process of the piezoelectric actuator. . In order to grasp the position of the internal electrode where the deviation occurs, a mark indicating the position of the internal electrode is provided on the surface of the piezoelectric actuator.
[0011]
According to a second aspect of the present invention, in the ink jet printer head according to the first aspect, in order to grasp the position of each internal electrode, a plurality of the marks are provided at positions corresponding to the plurality of internal electrodes. One is provided.
[0012]
The ink jet printer head according to claim 3 is the ink jet printer head according to claim 1 or 2, wherein the piezoelectric actuator includes a sheet, which is not sandwiched between the internal electrodes, laminated on the surface integrally with the piezoelectric sheet. In order to grasp the position of the internal electrode inside, the mark is provided on the internal surface spaced from the outer periphery of the sheet on the surface.
[0013]
An ink jet printer head according to a fourth aspect of the present invention is the ink jet printer head according to the third aspect, wherein the piezoelectric actuator has the surface electrode, and the mark is located at a distance from the plurality of surface electrodes.
[0014]
The inkjet printer head according to claim 5 is the inkjet printer head according to claim 4, wherein the pressure chambers and the internal electrodes are arranged in two rows, and the plurality of surface electrodes correspond to the internal electrodes in each row. Arranged along two opposing side edges of the surface sheet, the mark is located between the row of surface electrodes along the two side edges.
[0015]
The inkjet printer head according to claim 6 is the inkjet printer head according to any one of claims 1 to 5, wherein the mark reflects the same displacement as the displacement of the internal electrode, and is the same as the internal electrode. Consists of materials.
[0016]
The ink jet printer head according to claim 7 is the ink jet printer head according to any one of claims 1 to 6, wherein the mark has the same thickness as the surface electrode.
[0017]
An ink jet printer head according to an eighth aspect is the ink jet printer head according to any one of the first to seventh aspects, wherein the mark is provided on a side surface or a bottom surface of the piezoelectric actuator.
The method of manufacturing an ink jet printer head according to claim 9 includes: a cavity plate having a plurality of nozzles and pressure chambers for each of the plurality of nozzles; and a plurality of internal electrodes provided corresponding to each of the pressure chambers. Stacked by sandwiching between piezoelectric sheets, connected to each internal electrode on the surface and external control circuit A plate-type piezoelectric actuator having a plurality of surface electrodes connectable to a wiring member extending from the first is formed, and the plurality of internal electrodes are printed and formed on a first sheet material serving as the piezoelectric sheet. A second step of printing and forming a plurality of marks indicating the positions of the internal electrodes on the second sheet material laminated on the first sheet material at positions spaced from the surface electrodes. A printing step, the first sheet material on which the internal electrode is printed and the second sheet material on which the mark is printed, the mark and the internal electrode are made to correspond to each other, and the mark is on the surface Laminating step of laminating so as to be exposed, and a sintering step of sintering and integrating the laminated first sheet material and second sheet material.
[0018]
According to the method of manufacturing an ink jet printer head according to the ninth aspect, in the ink jet printer head, when a voltage is applied to any internal electrode among the plurality of internal electrodes, distortion in the stacking direction due to the piezoelectric occurs. Due to the pressure caused by this distortion, the internal volume of the pressure chamber corresponding to the internal electrode is reduced, so that the ink in the pressure chamber is ejected from the nozzle in the form of droplets and printing is performed on the paper. Here, in the piezoelectric actuator provided with the internal electrodes, first, a plurality of individual electrodes are printed and formed on the first sheet material by the first printing process. Next, marks indicating the positions of the plurality of individual electrodes are printed and formed on the second sheet material by the second printing step. Then, in the laminating process, the marks and the internal electrodes are made to correspond to each other and are laminated so that the marks are exposed on the surface. The laminated first sheet material and second sheet material are manufactured by integrating them by a sintering process. Therefore, even if the internal electrode is displaced in the sintering process, the position of the internal electrode can be grasped from the outside by the mark formed by the second printing process and exposed on the surface. .
[0019]
The method of manufacturing an ink jet printer head according to claim 10 is the method of manufacturing an ink jet printer head according to claim 9, wherein the second printing step includes the mark, the internal electrodes, A plurality of surface electrodes that can be connected to wiring members that are connected and extend from an external control circuit are printed simultaneously.
[0020]
An ink jet printer head manufacturing method according to claim 11 is the ink jet printer head manufacturing method according to claim 9 or 10, wherein the sintering step is performed in order to facilitate connection with a wiring member extending from an external control circuit. And a step of further printing an electrode material on the plurality of surface electrodes.
[0021]
The method for manufacturing an ink jet printer head according to claim 12 is the method for manufacturing an ink jet printer head according to any one of claims 9 to 11, wherein after the sintering step, the interval between the plurality of marks is measured. A step of combining the piezoelectric actuator with a cavity plate having the pressure chambers at intervals suitable for the intervals is provided.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a color ink jet printer which is an embodiment of the ink jet head of the present invention. In FIG. 1, the color inkjet printer 100 includes an ink cartridge 61 filled with, for example, four color inks of cyan, magenta, yellow, and black, and a piezoelectric inkjet head 6 for printing on paper 62. A head unit 63; a carriage 64 on which the ink cartridge 61 and the head unit 63 are mounted; a drive unit 65 that reciprocates the carriage 64 in a linear direction; and a piezoelectric inkjet head 6 that extends in the reciprocating direction of the carriage 64; A platen roller 66 and a purge device 67 are provided so as to face each other.
[0023]
The drive unit 65 includes a carriage shaft 71 disposed at the lower end portion of the carriage 64 and extending in parallel with the platen roller 66, a guide plate 72 disposed at the upper end portion of the carriage 64 and extending in parallel with the carriage shaft 71, and the carriage shaft 71. Two pulleys 73 and 74 disposed between the guide plate 72 and at both ends of the carriage shaft 71, and an endless belt 75 spanned between the pulleys 73 and 74 and joined to the carriage 64 Consists of.
[0024]
When one pulley 73 is rotated forward and backward by driving the motor, the carriage 64 joined to the endless belt 75 is moved to the carriage shaft 71 and the guide plate 72 as the pulley 73 rotates forward and backward. And reciprocally moved in a linear direction.
[0025]
The paper 62 is fed from a paper feed cassette (not shown) provided on the side of the ink jet printer 100 and introduced between the piezoelectric ink jet head 6 and the platen roller 66, and the piezoelectric ink jet head 6. Predetermined printing is performed by the ink ejected from the ink, and then the paper is discharged. In FIG. 1, the paper feed mechanism and paper discharge mechanism for the paper 62 are not shown.
[0026]
The purge device 67 is provided on the side of the platen roller 66 and is disposed so as to face the piezoelectric inkjet head 6 when the head unit 63 is at the reset position. The purge device 67 includes a purge cap 81 that abuts against an opening surface of the nozzle so as to cover a plurality of nozzles to be described later of the piezoelectric inkjet head 6, a pump 82 and a cam 83, and an ink reservoir 84. When the head unit 63 is at the reset position, the nozzle of the piezoelectric inkjet head 6 is covered with the purge cap 81, and the cam 83 drives the defective ink containing bubbles accumulated inside the piezoelectric inkjet head 6. Thus, the piezoelectric ink jet head 6 is recovered by being sucked by the pump 82. The sucked defective ink is stored in the ink reservoir 84.
[0027]
The cap 85 covers the plurality of nozzles 15 (see FIG. 2) of the piezoelectric inkjet head 6 mounted on the carriage 64 that is returned to the reset position when printing is completed in order to prevent ink from drying.
[0028]
FIG. 2 shows a perspective view of the head unit 63 with the nozzle 15 side up. As shown in FIG. 2, the head unit 63 mounted on the carriage 64 that runs along the paper 62 is formed in a substantially box shape with the upper surface open, and four ink cartridges 61 are detachably mounted from above. The ink supply passages 4 a, 4 b, 4 c, and 4 d that can be connected to the ink discharge portions of the ink cartridges 61 communicate with the lower surface of the bottom plate 5 of the head unit 63. ing. In this ink supply passage, a rubber-made packing 47 is arranged so as to be in close contact with ink supply holes 19a, 19b (to be described later) of the head unit 63.
[0029]
On the lower surface side of the bottom plate 5, four support portions 8 for arranging four piezoelectric inkjet heads 6 in parallel are formed in a stepped shape. Each support portion 8 is formed with a plurality of cavities 9 a and 9 b for fixing with a UV adhesive material so as to penetrate vertically.
[0030]
FIG. 3 is a perspective view of the piezoelectric inkjet head 6. As shown in FIG. 3, the piezoelectric inkjet head 6 includes a stacked cavity plate 10, a plate-type piezoelectric actuator 20 that is bonded and stacked on the cavity plate 10 via an adhesive or an adhesive sheet, A flexible flat cable 40 is overlapped and joined to the upper surface for electrical connection with an external device, and ink is ejected downward from the nozzle 15 opened on the lower surface side of the cavity plate 10. The piezoelectric actuator 20 will be described in detail with reference to FIG.
[0031]
FIG. 4 is an exploded perspective view of the cavity plate 10. FIG. 5 is an exploded perspective view of the cavity plate 10. As shown in FIG. 4, the cavity plate 10 has a structure in which five thin metal plates, ie, a nozzle plate 11, two manifold plates 12, a spacer plate 13, and a base plate 14, are laminated and bonded together with an adhesive. is there. In the present embodiment, each of these plates 11 to 14 is made of 42% nickel alloy steel plate (42 alloy) and has a thickness of about 50 μm to 150 μm. In addition, each of these plates 11-14 is not restricted to metal, For example, you may form with resin.
[0032]
As shown in FIG. 5, a plurality of narrow pressure chambers 16 extending in a direction perpendicular to the longitudinal direction of the base plate 14 are formed in the base plate 14 in two rows in a staggered arrangement. Further, on the spacer plate 13 side of the base plate 14, a throttle portion 16 d connected to each pressure chamber 16 and an ink supply hole 16 b connected to the throttle portion 16 d are recessed. Each ink supply hole 16 b communicates with the common ink chamber 12 a in the manifold plate 12 through each ink supply hole 18 formed in both the left and right portions of the spacer plate 13. Here, the cross-sectional area perpendicular to the direction in which the ink flows in each throttle portion 16 d is smaller than the cross-sectional area in each pressure chamber 16. This is because the flow path resistance is increased by reducing the cross-sectional area of the throttle portion 16d.
[0033]
One end portion 16a of each pressure chamber 16 has a through hole 17 having a small diameter formed in the staggered arrangement of nozzles 15 in the nozzle plate 11 in the spacer plate 13 and the two manifold plates 12 in the same staggered arrangement. Communicated through.
[0034]
As shown in FIG. 4, the base plate 14 and the spacer plate 13 are provided with two ink supply holes 19a for supplying ink from a common ink cartridge to the two common ink chambers 12a in the manifold plate 12. ing.
[0035]
As shown in FIG. 4, the two manifold plates 12 </ b> X and 12 </ b> Y have two common ink chambers across the row formed by the plurality of nozzles 15 in the nozzle plate 11. The common ink chambers 12 a and 12 b are located in a plane parallel to the surface formed by the plurality of pressure chambers 16 in the base plate 14, and are closer to the opening surfaces of the plurality of nozzles 15 in the nozzle plate 11 than the plurality of pressure chambers 16. In addition, the plurality of nozzles 15 extend in the row direction. The common ink chamber 12a of one manifold plate 12X is drilled so as to penetrate in the plate direction, and the common ink chamber 12a of the other manifold plate 12Y is recessed with the bottom side closed.
[0036]
Further, the common ink chambers 12a and 12b have a shape in which the cross-sectional area decreases at a constant rate in the direction away from the ink supply holes 19a and 19b at the end portions away from the ink supply holes 19a and 19b. This is to make it easier to discharge residual bubbles that tend to accumulate at the ends of the common ink chambers 12a and 12b.
[0037]
Further, the upper surfaces of the common ink chambers 12 a and 12 b are sealed by stacking the spacer plates 13 on the two manifold plates 12.
[0038]
As shown in FIG. 4, a plurality of ink ejection nozzles 15 having a minute diameter (about 25 μm in this embodiment) are arranged on the nozzle plate 11 at intervals of a minute pitch along the longitudinal direction of the nozzle plate 11. It is drilled in a staggered arrangement.
[0039]
With the configuration of the cavity plate 10 described above, the ink that has flowed into the common ink chambers 12a and 12b from the ink supply holes 19a and 19b formed in the one end portions of the base plate 14 and the spacer plate 13 flows into the ink supply holes 18 and The ink is distributed to the pressure chambers 16 through the ink supply holes 16b and the narrowed portions 16d. Then, ink flows in the direction of the one end portion 16 a of each pressure chamber 16, passes through each through hole 17, and reaches the nozzle 15 corresponding to each pressure chamber 16.
[0040]
6 is an exploded perspective view of the plate-type piezoelectric actuator 20, and FIG. 7 is a cross-sectional view of the plate-type piezoelectric actuator 20 in the arrow direction along the line VII-VII in FIG. As shown in FIGS. 6 and 7, the plate type piezoelectric actuator 20 is formed in a structure in which ten piezoelectric sheets 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 are laminated.
[0041]
Among the piezoelectric sheets 21 to 30, narrow individual electrodes 31 are provided on the upper surfaces of the piezoelectric sheets 26, 28, and 30 at positions corresponding to the pressure chambers 16 (see FIG. 5) provided in the cavity plate 10. Each is formed. Further, a discarded pattern electrode 32b, which is a land pattern that does not participate in the deformation of the piezoelectric sheet, is formed at a position corresponding to an end portion 32a of the common electrode 32 described later.
[0042]
On the upper surface of the piezoelectric sheets 25, 27, and 29, a strip-shaped common electrode 32 that is a common electrode for the plurality of pressure chambers 16 is formed. Further, a discarded pattern electrode 31b, which is a land pattern not involved in the deformation of the piezoelectric sheet, is formed at a position corresponding to the end portion 31a of the individual electrode 31. The discarded pattern electrodes 31b and 32b are formed to have the same thickness as the individual electrode 31 and the common electrode 32. When the piezoelectric sheets are laminated as will be described later, the piezoelectric sheet in the portion where the individual electrode 31 and the common electrode 32 are not formed is recessed. It is corrected. Although the common electrode 32 and the discard pattern electrode 31b are also formed on the upper surfaces of the piezoelectric sheets 22, 23, and 24, the piezoelectric operation is not performed on these sheets.
[0043]
On the upper surface of the uppermost piezoelectric sheet 21, a surface electrode 33 for each of the individual electrodes 31 and a surface electrode 34 for the common electrode 32 are arranged along side edges extending in parallel with the arrangement direction of the individual electrodes 31. It is provided in two rows. Further, a mark 35 is formed between the surface electrodes 33 and 34 formed in two rows on the upper surface of the piezoelectric sheet 21 so as to be spaced from the surface electrodes 33 and 34. The marks 35 are provided in one-to-one correspondence with the surface electrodes 33 and 34. That is, since the surface electrode 33 is provided in a one-to-one correspondence with the plurality of individual electrodes 31, the mark 35 is provided in a one-to-one correspondence with the plurality of individual electrodes 31. Become.
[0044]
Except for the lowermost piezoelectric sheet 30, all the other piezoelectric sheets 21 to 29 have the surface electrode 33, the individual electrode 31 and the discard pattern electrode 31 b at the corresponding positions (the same vertical position). A through hole 36 is formed so as to communicate (see FIG. 7). Similarly, a through hole 37 is formed so that the surface electrode 34 and the common electrode 32a and the discard pattern electrode 32b at the corresponding positions communicate with each other.
[0045]
The through holes 36 and 37 are filled with a conductive material, and are configured so that the individual electrodes 31 of each layer and the surface electrode 33 at a position corresponding thereto are electrically connected. 32 and the surface electrode 34 of the position corresponding to 32 are electrically connected.
[0046]
Next, a manufacturing method of the piezoelectric actuator will be described with reference to FIG. FIG. 8 is a perspective view showing patterns of individual electrodes, common electrodes, surface electrodes and the like on the material sheet of the piezoelectric actuator. First, a first material sheet 52 (ceramic green sheet) having a size in which a plurality of piezoelectric sheets 26 (same for 28 and 30) are arranged in a matrix is formed, and each piezoelectric material that becomes the piezoelectric sheets 26 and 28 is formed. Through holes 36 and 37 are drilled in advance along the periphery of the portion to be the sheet. Similarly, a second material sheet 51 (ceramic green sheet) having a size in which a plurality of piezoelectric sheets 22 (23, 24, 25, 27, and 29) are arranged in a matrix is formed, and each of the piezoelectric sheets is formed. Through holes 37 and 36 are drilled in advance along the periphery of the portion to be. Further, in the same manner as described above, a third material sheet 50 (ceramic green sheet) having a size in which a plurality of uppermost piezoelectric sheets 21 are arranged in a matrix is formed, and the uppermost piezoelectric sheet 21 on the surface thereof is formed. Through-holes 36 and 37 are drilled along the peripheral edge of the location.
[0047]
Next, on the surface of the green sheet 52, the individual electrodes 31 and the discard pattern electrodes 32b are provided for the portions to be the piezoelectric sheets 26, 28, 30. On the surface of the green sheet 51, the piezoelectric sheets 22, 23, 24, The common electrode 32 and the discarded pattern electrode 31b are provided for the portions 25, 27, and 29, and the surface electrodes 33 and 34 and the mark 35 are provided for the portion that becomes the uppermost piezoelectric sheet 21 on the surface of the green sheet 50, respectively. It is formed by screen printing of a conductive paste. Here, since each through-hole 36, 37 penetrates the upper and lower wide surfaces of each green sheet, the conductive paste penetrates into each through-hole 36, 37 and passes through each through-hole 36, 37. Each electrode portion can conduct electricity on the upper and lower surfaces of the piezoelectric sheet. Further, since the mark 35 can be printed at the same time as the surface electrodes 33 and 34, it is not necessary to provide a process for applying a new mark. Further, since the mark 35 is made of substantially the same material as that of the individual electrode 31, the mark 35 can reflect a shift similar to the positional shift of the internal electrode caused by shrinkage in a sintering process described later.
[0048]
Next, the sheets 50, 51, 52 are laminated. At this time, the individual electrode 31, the discarded pattern electrode 31b and the surface electrode 33 of each sheet correspond to the stacking direction, and the end 32a of the common electrode 32, the discarded pattern electrode 32b and the surface electrode 33 correspond to the stacking direction, And it laminates | stacks so that the surface electrodes 33 and 34 and the mark 35 of the sheet | seat 50 may be exposed, degreasing, sintering, and integrating. As a result, the individual electrode 31, the discarded pattern electrode 31b, and the surface electrode 33 of each sheet stacked one above the other are electrically connected via the through hole 36, and the common electrode 32, the discarded pattern electrode 32b, and the surface electrode 33 are Are electrically connected through the through hole 37.
[0049]
The surface electrodes 33 and 34 and the mark 35 are configured with substantially the same thickness, and when the sheets 50, 51 and 52 are stacked and pressed from above and below by a flat jig, the surface electrodes 33 and 34 are arranged between the surface electrodes 33 and 34. The surface electrodes 33 and 34 and the mark 35 are pressed at the same time so that the portion does not float up so that the entire sheets 50, 51 and 52 are flat.
[0050]
Thereafter, the laminated body is cut for each piezoelectric actuator at the position of the two-dot chain line in FIG. Further, the electrode material is again printed on the surface electrodes 33 and 34 of each piezoelectric actuator. This is because the electrodes 33 and 34 originally printed by the sintering process are oxidized, and the solderability with the flexible flat cable 40 described later is deteriorated. Therefore, after the sintering process, on the surface electrodes 33 and 34. Furthermore, it is for improving solderability by printing an electrode material.
[0051]
In the above-described sintering step, the laminate of the sheets 50, 51, 52 contracts as is well known. It is known that the amount of shrinkage differs between the central portion and the peripheral portion of the sheet, and the amount of shrinkage varies depending on the position in the same sintering furnace. Therefore, the pitch of the individual electrode 31 is different for each piezoelectric actuator, and when arbitrarily combined with the cavity plate 10, the individual electrode 31 and the pressure chamber 16 may not correspond.
[0052]
Therefore, the amount of contraction is grasped by the mark 35 formed on the upper surface of the piezoelectric actuator 20. That is, the contraction amount is measured by measuring the pitch P2 (FIG. 8) between both ends of the plurality of marks 35. Then, the measurement amount is divided into a plurality of groups for each predetermined range. Similarly, the pitch of the pressure chambers 16 of the cavity plate 10 is also measured and divided into a plurality of groups for each predetermined range. The piezoelectric actuator 20 and the cavity plate 10 are combined and joined.
[0053]
In addition, it can replace with the mark 35 and can measure the pitch of the surface electrodes 33 and 34 (the state before forming a new electrode material on it is preferable). However, since the contraction amount between the center and the peripheral portion of the piezoelectric actuator may be different, it is best to use the mark 35 corresponding to the upper side of the individual electrode 31.
[0054]
After that, the flexible flat cable 40 is joined to the surface electrodes 33 and 34 of the piezoelectric actuator, and the flexible flat cable 40 is used between the individual electrodes 31 and the common electrode 32 through the flexible flat cable 40 as compared with the normal ink ejection operation. A high voltage is applied, the portions of the piezoelectric sheets 25 to 29 sandwiched between the individual electrode 31 and the common electrode 32 are polarized, and these portions are formed as active layers. This polarization treatment can be performed before the piezoelectric actuator 20 is joined to the cavity plate 10 or the flexible flat cable 40.
[0055]
In addition, since the piezoelectric sheets 21 to 24 are only sandwiched between the common electrodes 32 and the surface electrodes 33 and 34 and are not polarized, they do not perform a piezoelectric operation. In these sheets, the piezoelectric actuator is warped or waved in the sintering process so that the flatness thereof is not impaired, and the active layer of the piezoelectric sheets 25 to 29 is deformed only in the direction of the pressure chamber 16. It functions as a constraining layer for doing so.
[0056]
Then, by applying a voltage between an arbitrary individual electrode 31 among the individual electrodes 31 of the piezoelectric actuator 20 in the piezoelectric inkjet head 6 and the common electrode 32, the individual electrode 31 to which a voltage is applied in the piezoelectric sheet. In the active portion corresponding to the above, distortion in the stacking direction due to piezoelectricity occurs. The ink in the pressure chamber 16 is ejected from the nozzle 15 in the form of droplets by the pressure caused by this distortion, and predetermined printing on the paper 62 is performed.
[0057]
As described above, according to the color ink jet printer 100 of the present embodiment, since the mark 35 indicating the position of the individual electrode 31 is provided on the surface of the piezoelectric actuator 20, the position of the individual electrode 31 can be easily set. I can grasp it. That is, even if the piezoelectric actuator 20 contracts due to the sintering process in the manufacturing process of the piezoelectric actuator, the position of the individual electrode 31 that has been displaced due to the contraction can be easily measured from the outside by this mark 35. In combination with the pressure chamber 16 of the adapted cavity plate 10, the expected excellent ink ejection performance can be exhibited.
[0058]
Although the present invention has been described based on the above embodiment, the present invention is not limited to the above embodiment, and various modifications and changes can be easily made without departing from the gist of the present invention. Can be inferred.
[0059]
For example, in the above-described embodiment, the mark 35 is provided on the surface of the uppermost layer 21 of the piezoelectric actuator 20, but the mark 35 is not necessarily provided at such a position, as long as it can be measured from the outside. The piezoelectric actuator 20 may be provided on the side surface or the bottom surface.
[0060]
Further, in the present embodiment, a plurality of marks 35 are provided in a one-to-one correspondence with a plurality of individual electrodes, but the marks 35 are not necessarily provided in a one-to-one correspondence with individual electrodes. Instead, one mark 35 may be provided for a plurality of individual electrodes 31.
[0061]
Further, the mark 35 only represents the position of the individual electrode 31 as an internal electrode, but the common electrode 32 can be individually provided corresponding to each pressure chamber in the same manner as the individual electrode 31. Reference numeral 35 denotes the position of the internal electrode composed of the common electrode 32 and the individual electrode 31.
[0062]
【The invention's effect】
According to the ink jet printer head of the first aspect, since the mark indicating the position of the internal electrode is provided on the surface of the piezoelectric actuator, the position of the internal electrode can be easily grasped. That is, even if the piezoelectric actuator contracts due to the sintering process in the manufacturing process of the piezoelectric actuator, the position of the internal electrode that has been displaced due to the contraction can be grasped by this mark. In combination with a piezoelectric actuator having a suitable internal electrode, there is an effect that the expected excellent ink ejection performance can be exhibited.
[0063]
According to the ink jet printer head of the second aspect, in addition to the effect produced by the ink jet printer head of the first aspect, a plurality of marks are provided at positions corresponding to the plurality of internal electrodes. The position corresponding to each internal electrode can be grasped.
[0064]
According to the ink jet printer head of the third aspect, in addition to the effect produced by the ink jet printer head of the first or second aspect, the piezoelectric actuator has a surface that is not sandwiched between the internal electrodes and the piezoelectric sheet. Since the mark is provided on the inner surface spaced from the outer periphery of the sheet on the surface, the position of the inner electrode can be adjusted even if the contraction amount differs between the center and the peripheral portion of the piezoelectric actuator. There is an effect that it can be grasped almost accurately.
[0065]
According to the ink jet printer head of the fourth aspect, in addition to the effect achieved by the ink jet printer head of the third aspect, the piezoelectric actuator is provided along a side edge of the surface sheet that extends in parallel with the arrangement direction of the internal electrodes. A plurality of surface electrodes connected to each internal electrode and connectable to a wiring member extending from an external control circuit, and the mark is positioned at a distance from the plurality of surface electrodes. Even if the contraction amount of the peripheral portion is large and the position of the surface electrode is shifted or another electrode material is provided on the surface electrode, the position of the internal electrode can be accurately grasped by the mark.
[0066]
According to the ink jet printer head of claim 5, in addition to the effect of the ink jet printer head of claim 4, the pressure chambers and the internal electrodes are arranged in two rows, and a plurality of surface electrodes are arranged in each row. Corresponding to the internal electrodes are arranged along two opposite side edges of the surface sheet, and the marks are located between the rows of surface electrodes along the two side edges, so that two rows of arrangements are formed. By using the mark, the mark can be arranged at a position where the position of the internal electrode can be easily grasped.
[0067]
According to the ink jet printer head of the sixth aspect, in addition to the effect produced by the ink jet printer head according to any one of the first to fifth aspects, the mark is made of the same material as the internal electrode. There is an effect that a shift similar to the positional shift of the internal electrode can be reflected.
[0068]
According to the inkjet printer head of the seventh aspect, in addition to the effect produced by the inkjet printer head according to any one of the first to sixth aspects, the mark is configured with the same thickness as the surface electrode. When a piezoelectric sheet is laminated in the manufacturing process and pressed with a flat jig from above the surface electrode and the mark, even when the laminated body has waviness, the waviness portion can be crushed into a flat surface. Accordingly, the degree of adhesion between the piezoelectric actuator and the cavity plate is increased, and the leakage of ink from the pressure chamber can be prevented, and the occurrence of defective ink jet printer heads can be prevented.
[0069]
According to the method of manufacturing an ink jet printer head according to claim 9, the first printing step of printing and forming a plurality of internal electrodes on the first sheet material to be a piezoelectric sheet, and the first sheet material are laminated. A second printing step for printing and forming a plurality of marks indicating the positions of the internal electrodes on the second sheet material; the first sheet material for printing and forming the internal electrodes; and the marks for printing. And laminating the second sheet material so that the mark and the internal electrode correspond to each other and the mark is exposed on the surface, the laminated first sheet material and the first Since the second sheet material on which the mark is printed is exposed on the surface, the same effect as in claim 1 is provided by the mark. There is.
[0070]
According to the method for manufacturing an ink jet printer head according to claim 10, in addition to the effect of the method for manufacturing the ink jet printer head according to claim 9, the second printing step is connected to the mark and each internal electrode. In addition, since the plurality of surface electrodes connectable to the wiring member extending from the external control circuit are simultaneously printed and formed, the mark can be applied without increasing the number of steps for applying the mark. Therefore, the productivity of the ink jet printer head can be improved.
[0071]
According to the method for manufacturing an ink jet printer head according to claim 11, in addition to the effect exhibited by the method for manufacturing the ink jet printer head according to claim 9 or 10, after the sintering step, the ink jet printer head further includes Since the step of printing and forming the electrode material is provided, the connection between the plurality of surface electrodes and the wiring member can be facilitated. That is, since the plurality of surface electrodes are oxidized by the sintering process, the solderability with the wiring member is deteriorated. Therefore, by further printing the electrode material on the plurality of surface electrodes after the sintering step, there is an effect that solderability is improved and generation of defective products can be suppressed.
[0072]
According to the method for manufacturing an ink jet printer head according to claim 12, in addition to the effect of the ink jet printer head according to any one of claims 9 to 11, the interval between the plurality of marks is measured after the sintering step. Since it has a process of combining a cavity plate having a pressure chamber with an interval suitable for the interval and a piezoelectric actuator, the internal electrode and the pressure chamber can be corresponded almost accurately, and the desired ink ejection performance There is an effect that it is possible to manufacture an ink jet printer head that reliably exhibits the above.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a color ink jet printer which is an embodiment of an ink jet head of the present invention.
FIG. 2 is a perspective view with the nozzle side of the head unit facing up.
FIG. 3 is a perspective view of each component of the piezoelectric inkjet head.
FIG. 4 is an exploded perspective view of a cavity plate.
FIG. 5 is an exploded enlarged perspective view of a cavity plate.
FIG. 6 is an exploded enlarged perspective view of a piezoelectric actuator.
7 is an enlarged sectional view taken along line VII-VII in FIG.
FIG. 8 is a perspective view showing patterns of individual electrodes, common electrodes, surface electrodes and the like in the material sheet.
[Explanation of symbols]
6 Inkjet printer head
10 Cavity plate
15 nozzles
16 Pressure chamber
20 Piezoelectric actuator
21-30 Piezoelectric sheet
31 Individual electrode (internal electrode)
31b Discard pattern electrode
32 Common electrode
32b Discard pattern electrode
35 mark
33, 34 Surface electrode
36, 37 Through hole
40 Flexible flat cable (wiring member)

Claims (12)

A cavity plate having a plurality of nozzles and pressure chambers for each of the plurality of nozzles, and a plurality of internal electrodes provided corresponding to each of the pressure chambers are sandwiched between piezoelectric sheets and laminated on the surface. In an inkjet printer head configured by overlapping plate-type piezoelectric actuators having a plurality of surface electrodes that can be connected to wiring members connected to each internal electrode and extending from an external control circuit ,
2. An ink jet printer head according to claim 1, wherein a mark indicating the position of the internal electrode is provided on the surface of the piezoelectric actuator at a position spaced from the surface electrode.   2. The ink jet printer head according to claim 1, wherein a plurality of the marks are provided at positions corresponding to the plurality of internal electrodes on a one-to-one basis.   The piezoelectric actuator is provided with a sheet that is not sandwiched between the internal electrodes on the surface, and is laminated with the piezoelectric sheet, and the mark is provided on an inner surface spaced from the outer periphery of the sheet on the surface. An ink jet printer head according to claim 1 or 2. The piezoelectric actuator has the plurality of surface electrodes along a side edge of the surface sheet extending in parallel with the arrangement direction of the internal electrodes,
The inkjet printer head according to claim 3, wherein the mark is located at a distance from the plurality of surface electrodes. The pressure chambers and internal electrodes are arranged in two rows,
The plurality of surface electrodes are arranged along two opposing side edges of the surface sheet corresponding to the internal electrodes of each row,
The ink-jet printer head according to claim 4, wherein the mark is located between the row of the surface electrodes along the two side edges.   6. The ink jet printer head according to claim 1, wherein the mark is made of the same material as the internal electrode.   The ink-jet printer head according to claim 4, wherein the mark has the same thickness as the surface electrode.   The ink jet printer head according to claim 1, wherein the mark is provided on a side surface or a bottom surface of the piezoelectric actuator. A cavity plate having a plurality of nozzles and pressure chambers for each of the plurality of nozzles, and a plurality of internal electrodes provided corresponding to each of the pressure chambers are sandwiched between piezoelectric sheets and laminated on the surface. In a method of manufacturing an ink jet printer head constituted by overlapping a plate-type piezoelectric actuator having a plurality of surface electrodes that can be connected to a wiring member connected to each internal electrode and extending from an external control circuit ,
A first printing step of printing and forming the plurality of internal electrodes on a first sheet material to be the piezoelectric sheet;
A second printing step of printing and forming a plurality of marks indicating the position of each internal electrode on the second sheet material laminated on the first sheet material at a position spaced from the surface electrode;
The first sheet material on which the internal electrode is printed and the second sheet material on which the mark is printed are made to correspond to the mark and the internal electrode, and the mark is exposed on the surface. Laminating step of laminating to,
Method of manufacturing an inkjet printer head, characterized in that you are a sintering step of the sintering the stacked first sheet material and the second sheet material integral.   10. The method of manufacturing an ink jet printer head according to claim 9, wherein in the second printing step, the mark and the surface electrode are printed and formed simultaneously.   The method of manufacturing an ink jet printer head according to claim 9, further comprising a step of printing and forming an electrode material on the plurality of surface electrodes after the sintering step.   The step of measuring the interval between the plurality of marks after the sintering step, and combining the piezoelectric actuator with a cavity plate having the pressure chambers at intervals suitable for the interval. The manufacturing method of the inkjet printer head in any one of 9 to 11.

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