JP2021176249A - Piezoelectric actuator, and manufacturing method thereof - Google Patents

Abstract

To surely satisfy a requirement (I) even when a thin wall part is formed in an electrode.SOLUTION: A piezoelectric actuator 22 has a configuration of satisfying a requirement (I) "requirement that a second active part 62 is separated from a first active part 61 to one direction (left direction of Fig. 5) of an X direction", and a requirement (II-a) "requirement that a third active part 63 is overlapped with an end part (right end of Fig. 5) of the other direction of the X direction in the first active part 61 to a Z direction". In the configuration, a thin wall part 52s is formed in the other end 52ay and is not formed in one end 52ax in an individual part 52a of a high potential electrode 52. A thin wall part 53s is formed in one end 53ax and is not formed in the other end 53ay in an individual part 53a of a low potential electrode 53.SELECTED DRAWING: Figure 5

Description

The present invention relates to a piezoelectric actuator having a piezoelectric body having a plurality of piezoelectric layers and first to third electrodes, the piezoelectric body having first to third active portions, and a method for manufacturing the same.

Patent Document 1 includes a piezoelectric body having a plurality of piezoelectric layers and first to third electrodes, and the piezoelectric body has first to third portions (first to third active parts of the present invention). In the above, by satisfying the following requirements (I) and (II), the drive deterioration of the actuator portion can be suppressed (specifically, the deformation amount of the second portion decreases as the number of deformations of the actuator portion increases. However, it is shown that the amount of deformation increases in the third portion, and the amount of deformation of one actuator portion as a whole becomes stable).

Requirement (I): "The other end of the second part (second active part of the present invention) is, in the first direction, the one end of the second part and the first part (first activity of the present invention). The other end of the second active portion 62 in FIG. 6 of Patent Document 1 is located between the one end of the second active portion 62 and the first active portion 62 in the X direction. It is located between one end of the portion 61, that is, the second active portion 62 is separated from the first active portion 61 in one direction in the X direction.)

Requirement (II): "The end of the third part (third active part of the present invention)" is at any of the following positions (a) to (c) (a) "In the first direction. A position between the one end of the first portion (the first active portion of the present invention) and the other end of the first portion ”(for example, in FIG. 6 of Patent Document 1, one end of the second active portion 63 is , The position between one end of the first active portion 61 and the other end of the first active portion 61 in the X direction, that is, the second active portion 63 is the other end of the first active portion 61 in the X direction. It overlaps with the part in the Z direction.)
(B) "In the first direction, the same position as the other end of the first portion (first active portion of the present invention)" (for example, in FIGS. 16 (a) and 16 (b) of Patent Document 1, the first 2 One end of the active portion 63 is in the same position as the other end of the first active portion 61 in the X direction. That is, the second active portion 63 is X with the other end of the first active portion 61 in the X direction. Adjacent to the direction.)
(C) "Position between the other end of the first portion (first active portion of the present invention) and the other end of the third portion (third active portion of the present invention) in the first direction. The distance from the other end of the first part to the one end of the third part in the first direction is the distance from the other end of the second part to the one end of the first part. A position shorter than the distance in one direction ”(for example, in FIG. 16C of Patent Document 1, one end of the second active portion 63 is the other end 61b of the first active portion 61 and the second active portion 61 in the X direction. It is located between the other end 63b of the portion 63 (that is, the second active portion 63 is separated from the first active portion 61 to the other in the X direction), and the second active portion 63 and the first active portion 63. The distance t3 in the X direction from 61 is shorter than the distance t2 in the X direction between the second active portion 62 and the first active portion 61.)

JP-A-2019-177562

When the electrode is formed by screen printing using a squeegee, bleeding is likely to occur at the downstream end portion of the electrode in the moving direction of the squeegee, and the bleeding may be formed as a thin-walled portion.

In the configuration of Patent Document 1, when a thin-walled portion is formed on the electrode, the requirement (I) may not be satisfied depending on the position where the thin-walled portion is formed (for example, in FIG. 6 of Patent Document 1, the first The two active parts 62 and the first active part 61 may not be separated from each other in the X direction, may be adjacent to each other in the X direction, or may partially overlap in the Z direction). In this case, because the requirement (I) is not satisfied, not only the amount of deformation of the third active part but also the amount of deformation of the second active part increases as the number of times of deformation of the actuator part increases, and the actuator part as a whole increases. The amount of deformation changes.

An object of the present invention is to provide a piezoelectric actuator and a method for manufacturing the same, which can surely satisfy the above requirement (I) even when a thin portion is formed on the electrode.

The piezoelectric actuator according to the first aspect of the present invention includes a piezoelectric body having a plurality of piezoelectric layers laminated in the first direction, a first electrode, and a second electrode separated from the first electrode in the first direction. A piezoelectric actuator comprising a third electrode separated from the first electrode in the first direction, the piezoelectric body being sandwiched between the first electrode and the second electrode in the first direction. It is sandwiched between the first active portion, the second active portion sandwiched between the first electrode and the third electrode in the first direction, and the first electrode and the third electrode in the first direction. A third active portion, which has a third active portion separated from the second active portion in a second direction orthogonal to the first direction, and the first active portion is in the second direction. It has a portion arranged between the second active part and the third active part, and the second active part is separated from the first active part in one of the second directions, and the third active part is separated from the first active part. The part is located at any of the following positions (a) to (c).
(A) Position of the first active portion that overlaps the other end of the second direction in the first direction (b) In the other end of the first active portion in the second direction and in the second direction Adjacent position (c) The first active portion is separated from the other in the second direction, and the distance between the third active portion and the first active portion in the second direction is the distance between the second active portion and the second active portion. A position shorter than the distance between the first active portion and the first active portion in the second direction. The second electrode has a second thick portion and a second thin wall having a thickness smaller than that of the second thick portion in the first direction. The second electrode has a portion, and in the second direction, one end forming one end of the second direction in the first active portion and the second direction in the first active portion. The second thin-walled portion is formed at the other end of the second electrode and is not formed at the other end of the second electrode. And.

The piezoelectric actuator according to the second aspect of the present invention includes a piezoelectric body having a plurality of piezoelectric layers laminated in the first direction, a first electrode, and a second electrode separated from the first electrode in the first direction. A piezoelectric actuator comprising a third electrode separated from the first electrode in the first direction, the piezoelectric body being sandwiched between the first electrode and the second electrode in the first direction. It is sandwiched between the first active portion, the second active portion sandwiched between the first electrode and the third electrode in the first direction, and the first electrode and the third electrode in the first direction. A third active portion, which has a third active portion separated from the second active portion in a second direction orthogonal to the first direction, and the first active portion is in the second direction. It has a portion arranged between the second active part and the third active part, and the second active part is separated from the first active part in one of the second directions, and the third active part is separated from the first active part. The part is located at any of the following positions (a) to (c).
(A) Position of the first active portion that overlaps the other end of the second direction in the first direction (b) In the other end of the first active portion in the second direction and in the second direction Adjacent position (c) The first active portion is separated from the other in the second direction, and the distance between the third active portion and the first active portion in the second direction is the distance between the second active portion and the second active portion. Position shorter than the distance between the first active portion and the second direction The third electrode has a third thick portion and a third thin wall having a thickness smaller than that of the third thick portion in the first direction. The third electrode has a portion, and in the second direction, one end forming one end of the second direction in the third active portion and the second direction in the second active portion. The third thin-walled portion is formed at the one end of the third electrode and is not formed at the other end of the third electrode. And.

The method for manufacturing a piezoelectric actuator according to a third aspect of the present invention includes a piezoelectric body having a plurality of piezoelectric layers laminated in the first direction, a first electrode, and a first electrode separated from the first electrode in the first direction. A method for manufacturing a piezoelectric actuator including two electrodes and a third electrode separated from the first electrode in the first direction. The piezoelectric body is the first electrode and the first electrode in the first direction. A first active portion sandwiched between two electrodes, a second active portion sandwiched between the first electrode and the third electrode in the first direction, and the first electrode and the first electrode in the first direction. It has a third active portion sandwiched between the three electrodes and a third active portion separated from the second active portion in a second direction orthogonal to the first direction, and the first active portion has. The second active portion has a portion arranged between the second active portion and the third active portion in the second direction, and the second active portion is separated from the first active portion in one of the second directions. However, the third active portion is located at any of the following positions (a) to (c).
(A) Position of the first active portion that overlaps the other end of the second direction in the first direction (b) In the other end of the first active portion in the second direction and in the second direction Adjacent position (c) The first active part is separated from the other in the second direction, and the distance between the third active part and the first active part in the second direction is the distance between the second active part and the second active part. A position shorter than the distance from the first active portion in the second direction The second electrode is provided with a step of moving the squeegee from one of the second directions toward the other and forming the second electrode by screen printing. It is characterized by.

The method for manufacturing a piezoelectric actuator according to a fourth aspect of the present invention includes a piezoelectric body having a plurality of piezoelectric layers laminated in the first direction, a first electrode, and a first electrode separated from the first electrode in the first direction. A method for manufacturing a piezoelectric actuator including two electrodes and a third electrode separated from the first electrode in the first direction. The piezoelectric body is the first electrode and the first electrode in the first direction. A first active portion sandwiched between two electrodes, a second active portion sandwiched between the first electrode and the third electrode in the first direction, and the first electrode and the first electrode in the first direction. It has a third active portion sandwiched between the three electrodes and a third active portion separated from the second active portion in a second direction orthogonal to the first direction, and the first active portion has. The second active portion has a portion arranged between the second active portion and the third active portion in the second direction, and the second active portion is separated from the first active portion in one of the second directions. However, the third active portion is located at any of the following positions (a) to (c).
(A) Position of the first active portion that overlaps the other end of the second direction in the first direction (b) In the other end of the first active portion in the second direction and in the second direction Adjacent position (c) The first active part is separated from the other in the second direction, and the distance between the third active part and the first active part in the second direction is the distance between the second active part and the second active part. A position shorter than the distance from the first active portion in the second direction The third electrode is provided with a step of moving the squeegee from the other in the second direction toward one side and forming the third electrode by screen printing. It is characterized by.

FIG. 5 is an overall configuration diagram of a printer 1 including a head 3 provided with a piezoelectric actuator 22 according to the first embodiment of the present invention. It is a top view of the head 3 of FIG. It is a top view which shows each of the three piezoelectric layers 41 to 43 in the piezoelectric actuator 22 of FIG. 2 is a cross-sectional view taken along the line IV-IV of FIGS. 2 and 3. 2 is a cross-sectional view taken along the line VV of FIGS. 2 and 3. It is a figure which shows the operation of the actuator part in the cross section of FIG. FIG. 5 is a cross-sectional view corresponding to FIG. 5, showing a step of forming a high potential electrode 52 on the upper surface of the piezoelectric layer 42 by screen printing. It is sectional drawing corresponding to FIG. 5 which shows the piezoelectric actuator 222 which concerns on 2nd Embodiment of this invention. It is sectional drawing corresponding to FIG. 5 which shows the piezoelectric actuator 322, 422, 522 which concerns on 3rd to 5th Embodiment of this invention, respectively.

In the following description, the Z direction is the vertical direction, and the X and Y directions are the horizontal directions. Both the X and Y directions are orthogonal to the Z direction. The X direction is orthogonal to the Y direction. The Z direction corresponds to the "first direction" of the present invention, and the X direction corresponds to the "second direction" of the present invention.

<First Embodiment>
First, with reference to FIG. 1, the overall configuration of the printer 1 including the head 3 provided with the piezoelectric actuator 22 according to the first embodiment of the present invention will be described.

The printer 1 includes a head 3, a carriage 2, and two transport roller pairs 4.

The carriage 2 is supported by two guide rails 5 extending in the Y direction, and can move in the Y direction along the guide rails 5.

The head 3 is a serial type, is mounted on the carriage 2, and can move in the Y direction together with the carriage 2. A plurality of nozzles 15 are opened on the lower surface of the head 3 (the surface facing downward in the Z direction).

The two transport roller pairs 4 are arranged so as to sandwich the carriage 2 in the X direction. Under the control of the control unit (not shown) of the printer 1, the paper P is transported in the transport direction along the X direction by rotating the transport roller pair 4 in a state of sandwiching the paper P.

The control unit alternately performs an ejection operation of ejecting ink from the nozzle 15 while moving the head 3 together with the carriage 2 in the Y direction, and a conveying operation of conveying a predetermined amount of paper P in the conveying direction by the conveying roller pair 4. Let me. As a result, the image is recorded on the paper P.

Next, the configuration of the head 3 will be described with reference to FIGS. 2 to 7.

As shown in FIG. 2, the head 3 includes a flow path unit 21, a piezoelectric actuator 22, and a COF (Chip On Film) 23.

The flow path unit 21 has a rectangular shape when viewed from the Z direction, and has two sides 21a and 21b along the Y direction and two sides 21c and 21d along the X direction.

Like the flow path unit 21, the piezoelectric actuator 22 has a rectangular shape when viewed from the Z direction, and has two sides 22a and 22b along the Y direction and two sides 22c and 22d along the X direction. The piezoelectric actuator 22 is one size smaller than the flow path unit 21 when viewed from the Z direction.

As shown in FIG. 4, the flow path unit 21 is composed of four plates 31 to 34 stacked in the Z direction.

A plurality of pressure chambers 10 are formed in the plate 31. As shown in FIG. 2, each pressure chamber 10 has a substantially rectangular shape when viewed from the Z direction, and the length in the Y direction is longer than the length in the X direction. The plurality of pressure chambers 10 form four pressure chamber rows 9. The four pressure chamber rows 9 are arranged in the Y direction. Each pressure chamber row 9 is composed of eight pressure chambers 10 arranged at equal intervals in the X direction.

As shown in FIG. 4, the plate 32 is formed with through holes 12 and 13 for each pressure chamber 10. The through holes 12 and 13 overlap with one end 10c in the Y direction and the other end 10d in the Y direction of the corresponding pressure chamber 10 in the Z direction, respectively. The through hole 12 has a cross-sectional area orthogonal to the Z direction smaller than the cross-sectional area orthogonal to the Y direction in the pressure chamber 10, and functions as a throttle flow path.

As shown in FIG. 4, a through hole 14 is formed in the plate 33 for each through hole 13. The through hole 14 overlaps with the corresponding through hole 13 in the Z direction.

As shown in FIG. 4, the plate 33 is further formed with four manifold flow paths 11. As shown in FIG. 2, the four manifold flow paths 11 correspond to each of the four pressure chamber rows 9. Each manifold flow path 11 extends in the X direction and has a portion that overlaps the eight pressure chambers 10 of the corresponding pressure chamber row 9 in the Z direction. Each manifold flow path 11 communicates with eight pressure chambers 10 in the corresponding pressure chamber row 9 through through holes 12.

On the upper surface of the plate 31, four ink supply ports 8 are formed in a region where the piezoelectric actuator 22 is not arranged (see FIG. 2). The four ink supply ports 8 correspond to each of the four manifold flow paths 11. Each ink supply port 8 is located at a position overlapping the one end (lower end in FIG. 2) of the corresponding manifold flow path 11 in the X direction in the Z direction. Ink is supplied from the four ink supply ports 8 to each of the four manifold flow paths 11.

As shown in FIG. 4, a plurality of nozzles 15 are formed through the plate 34. The plurality of nozzles 15 overlap with the through hole 14 in the Z direction, respectively. The nozzle 15 communicates with the pressure chamber 10 through the through holes 13 and 14.

The ink supplied to each manifold flow path 11 flows upward in the Z direction through the through hole 12 and flows into the pressure chamber 10. The ink flows in the pressure chamber 10 from one end 10c toward the other end 10d along the Y direction, flows downward in the through holes 13 and 14 in the Z direction, and is ejected from the nozzle 15.

As shown in FIG. 4, the piezoelectric actuator 22 is located above the flow path unit 21 in the Z direction and is fixed to the upper surface of the plate 31.

The piezoelectric actuator 22 has a piezoelectric body 40, an ink separation layer 44, a plurality of drive electrodes 51, a high potential electrode 52, and a low potential electrode 53. The drive electrode 51 corresponds to the "first electrode" of the present invention, the high potential electrode 52 corresponds to the "second electrode" of the present invention, and the low potential electrode 53 corresponds to the "third electrode" of the present invention.

The piezoelectric body 40 includes three piezoelectric layers 41 to 43 laminated in the Z direction. The piezoelectric layers 41 to 43 and the ink separation layer 44 have the same shape and size as each other when viewed from the Z direction, and define the outer shape of the rectangular piezoelectric actuator 22 shown in FIG.

As shown in FIG. 4, the ink separation layer 44 is arranged on the upper surface of the plate 31 and covers all the pressure chambers 10 formed in the plate 31. The ink separation layer 44 is made of, for example, a metal material such as stainless steel, a piezoelectric material containing lead zirconate titanate as a main component, a synthetic resin material, or the like.

The piezoelectric layer 43 is arranged on the upper surface of the ink separation layer 44. The piezoelectric layer 42 is arranged on the upper surface of the piezoelectric layer 43. The piezoelectric layer 41 is arranged on the upper surface of the piezoelectric layer 42. The piezoelectric layers 41 to 43 are made of a piezoelectric material containing lead zirconate titanate as a main component.

The plurality of drive electrodes 51, the high potential electrode 52, and the low potential electrode 53 are separated from each other in the Z direction. Specifically, a plurality of drive electrodes 51, a high potential electrode 52, and a low potential electrode 53 are arranged in order from the top in the Z direction.

As shown in FIG. 3A, the plurality of drive electrodes 51 are arranged on the upper surface of the piezoelectric layer 41, and are provided corresponding to each of the plurality of pressure chambers 10. That is, the plurality of drive electrodes 51 form four rows each composed of eight drive electrodes 51 arranged at equal intervals in the X direction, as in the case of the plurality of pressure chambers 10. Each drive electrode 51 includes a portion that overlaps the corresponding pressure chamber 10 in the Z direction and a portion that does not overlap the corresponding pressure chamber 10 in the Z direction. In each drive electrode 51, the non-overlapping portion is located on one side in the X direction (below FIG. 3A) with respect to the overlapping portion.

In each drive electrode 51, a contact that is electrically connected to the wiring of the COF 23 (see FIG. 2) is provided in the non-overlapping portion. The driver IC 24 mounted on the COF 23 individually imparts either a high potential (VDD potential) or a low potential (GND potential) to the plurality of drive electrodes 51 via the wiring of the COF 23.

As shown in FIG. 3B, the high potential electrode 52 is arranged on the upper surface of the piezoelectric layer 42, and has a plurality of individual portions 52a, four connecting portions 52b, a connecting portion 52c, and a drawing portion 52d. .. The plurality of individual portions 52a are provided corresponding to each of the plurality of pressure chambers 10. Each individual portion 52a overlaps the corresponding pressure chamber 10 in the Z direction. The four connecting portions 52b are provided corresponding to each of the four pressure chamber rows 9. Each connection portion 52b extends in the X direction and connects one end (right end in FIG. 3B) of the individual portion 52a corresponding to each of the eight pressure chambers 10 of the pressure chamber row 9 in the Y direction. There is. The connecting portion 52c extends in the Y direction and connects one ends (lower ends of FIG. 3B) of the four connecting portions 52b in the X direction. The pull-out portion 52d is pulled out from the other end of the connecting portion 52c in the Y direction (the left end in FIG. 3 (b)) to the other end in the X direction (above the upper side of FIG. 3 (b)). The direction in which the drawer portion 52d extends from the connecting portion 52c and the direction in which each connecting portion 52b extends from the connecting portion 52c are the same as each other. The extraction portion 52d is connected to the surface electrode 72 via a through hole 41x (see FIG. 3A) formed in the piezoelectric layer 41. The surface electrode 72 is arranged on the upper surface of the piezoelectric layer 41 and overlaps the extraction portion 52d in the Z direction.

The surface electrode 72 is electrically connected to the wiring of the COF 23 (see FIG. 2). The driver IC 24 applies a high potential (VDD potential) to the high potential electrode 52 via the wiring of the COF 23.

As shown in FIG. 3C, the low potential electrode 53 is arranged on the upper surface of the piezoelectric layer 43 and has a plurality of individual portions 53a, four connecting portions 53b, a connecting portion 53c, and a drawing portion 53d. .. An individual portion 53a is arranged between two pressure chambers 10 adjacent to each other in the X direction. Further, an individual portion 53a is arranged between the side 22a of the piezoelectric actuator 22 and the pressure chamber 10 adjacent to the side 22a in the X direction. Of the plurality of individual portions 53a, the individual portions 53a excluding the four individual portions 53a located at one end in the X direction (the lower end of FIG. 3C) are placed in two pressure chambers 10 adjacent to each other in the X direction. It straddles and has a portion that overlaps the two pressure chambers 10 in the Z direction. Each of the four individual portions 53a has a side 22a, a pressure chamber 10 adjacent to each other in the X direction, and a portion overlapping in the Z direction. The four connecting portions 53b are provided corresponding to each of the four pressure chamber rows 9. Each connection portion 53b extends in the X direction and connects the other ends (left end in FIG. 3C) of the individual portions 53a corresponding to each of the eight pressure chambers 10 in the pressure chamber row 9 in the Y direction. ing. The connecting portion 53c extends in the Y direction and connects the other ends (upper end of FIG. 3C) of the four connecting portions 53b in the X direction. The connecting portion 53c has a portion that overlaps the side 22b of the piezoelectric actuator 22 with each of the four pressure chambers 10 adjacent to each other in the X direction in the Z direction. The drawer portion 53d is pulled out from the other end of the connecting portion 53c in the Y direction (the left end in FIG. 3C) to one in the X direction (below FIG. 3C). The direction in which the drawer portion 53d extends from the connecting portion 53c and the direction in which each connecting portion 53b extends from the connecting portion 53c are the same as each other. The extraction portion 53d is connected to the surface electrode 73 through the through hole 41y formed in the piezoelectric layer 41 (see FIG. 3A) and the through hole 42y formed in the piezoelectric layer 42 (see FIG. 3B). It is connected. The surface electrode 73 is arranged on the upper surface of the piezoelectric layer 41 and overlaps the extraction portion 53d in the Z direction.

The surface electrode 73 is electrically connected to the wiring of the COF 23 (see FIG. 2). The driver IC 24 applies a low potential (GND potential) to the low potential electrode 53 via the wiring of the COF 23.

As shown in FIGS. 4 and 5, the portion of the piezoelectric layer 41 sandwiched between the driving electrode 51 and the high potential electrode 52 in the Z direction is referred to as a “first active portion 61”. Of the piezoelectric layers 41 and 42, the portions sandwiched between the drive electrode 51 and the low potential electrode 53 in the Z direction are referred to as "second active portion 62" and "third active portion 63". The first active part 61 is mainly polarized upward, and the second active part 62 and the third active part 63 are mainly polarized downward.

The piezoelectric actuator 22 has an actuator unit 60 composed of a first active unit 61, a second active unit 62, and a third active unit 63 for each pressure chamber 10.

The second active part 62 and the third active part 63 have a function of suppressing crosstalk. Crosstalk is a phenomenon in which pressure fluctuations associated with deformation of the actuator unit 60 in a certain pressure chamber 10 are transmitted to another pressure chamber 10 adjacent to the pressure chamber 10 in the X direction.

Hereinafter, with reference to FIG. 5, the positional relationship between the active units 61 to 63 in one actuator unit 60 and the positional relationship between the active units 61 to 63 of one actuator unit 60 and the corresponding pressure chamber 10 will be described. do.

The first active portion 61 overlaps the substantially central region of the pressure chamber 10 in the X direction in the Z direction, and does not have a portion that does not overlap the pressure chamber 10 in the Z direction. The second active portion 62 and the third active portion 63 are separated from each other in the X direction. The first active portion 61 has a portion arranged between the second active portion 62 and the third active portion 63 in the X direction.

The second active portion 62 is separated from the first active portion 61 in one direction in the X direction (left side in FIG. 5), and overlaps with one end in the X direction (left end in FIG. 5) of the pressure chamber 10 in the Z direction. It has a pressure chamber 10 and a portion that does not overlap in the Z direction.

The third active portion 63 has a portion that overlaps the region between the center of the pressure chamber 10 in the X direction and the other end (right end in FIG. 5) in the Z direction and does not overlap the pressure chamber 10 in the Z direction. Not. The third active portion 63 overlaps the other end portion (right end in FIG. 5) in the X direction of the first active portion 61 in the Z direction.

Next, with reference to FIG. 6, the operation of the actuator unit 60 corresponding to the nozzle 15 when the ink is ejected from the nozzle 15 will be described.

Before the printer 1 starts the recording operation, a low potential (GND potential) is applied to each drive electrode 51 as shown in FIG. 6A. At this time, in each actuator section 60, an upward electric field equal to the polarization direction is generated in the first active section 61 due to the potential difference between the drive electrode 51 and the high potential electrode 52, and the first active section 61 is in the plane direction (X direction). And the direction along the Y direction). As a result, the portion of the laminate composed of the piezoelectric body 40 and the ink separation layer 44 that overlaps the pressure chamber 10 in the Z direction is bent so as to be convex (downward) toward the pressure chamber 10. At this time, the volume of the pressure chamber 10 is smaller than that in the case where the laminated body is flat.

When the printer 1 starts the recording operation and ink is ejected from a certain nozzle 15, first, as shown in FIG. 6B, the potential of the drive electrode 51 corresponding to the nozzle 15 is a low potential (GND potential). ) Can be switched to a high potential (VDD potential). At this time, in the actuator unit 60, the contraction of the first active unit 61 is eliminated by eliminating the potential difference between the drive electrode 51 and the high potential electrode 52. On the other hand, when the potential difference between the driving electrode 51 and the low potential electrode 53 is generated, a downward electric field equal to the polarization direction is generated in the second active portion 62 and the third active portion 63, and the second active portion 62 and the third active portion 62 are activated. The portion 63 contracts in the plane direction. However, the second active unit 62 and the third active unit 63 have a crosstalk suppressing function as described above, and hardly contribute to the deformation of the actuator unit 60. That is, at this time, the laminated body does not bend so that the portion overlapping the pressure chamber 10 in the Z direction becomes convex (upward) in the direction away from the pressure chamber 10, and is in a flat state. As a result, the volume of the pressure chamber 10 becomes larger than that in FIG. 6A.

After that, as shown in FIG. 6A, the potential of the drive electrode 51 corresponding to the nozzle 15 is switched from a high potential (VDD potential) to a low potential (GND potential). At this time, in the actuator section 60, the contraction of the second active section 62 and the third active section 63 is eliminated by eliminating the potential difference between the drive electrode 51 and the low potential electrode 53. On the other hand, due to the potential difference between the driving electrode 51 and the high potential electrode 52, an upward electric field equal to the polarization direction of the first active portion 61 is generated, and the first active portion 61 contracts in the plane direction. As a result, the portion of the laminated body that overlaps the pressure chamber 10 in the Z direction bends so as to be convex (downward) toward the pressure chamber 10. At this time, since the volume of the pressure chamber 10 is greatly reduced, a large pressure is applied to the ink in the pressure chamber 10, and the ink is ejected from the nozzle 15.

By repeating such an operation of the actuator unit 60, there is a concern that the amount of deformation of the actuator unit 60 may decrease (that is, drive deterioration). However, in the present embodiment, the drive deterioration of the actuator unit 60 can be suppressed by satisfying the following requirements (I) and (II-a).

Requirement (I): The second active part 62 is separated from the first active part 61 in one of the X directions (left side in FIG. 5).

Requirement (II-a): The third active portion 63 overlaps the other end of the first active portion 61 in the X direction (the right end in FIG. 5) in the Z direction.

Specifically, as shown in Japanese Patent Application Laid-Open No. 2019-177562, by satisfying the above requirements (I) and (II-a), the second activity increases as the number of deformations of the actuator unit 60 increases. Although the amount of deformation of the portion 62 may decrease, the amount of deformation of the third active portion 63 increases, and the amount of deformation of one actuator unit 60 as a whole becomes stable.

Here, the piezoelectric actuator 22 of the present embodiment is manufactured by sequentially forming the piezoelectric layers 41 to 43 and the electrodes 51 to 53 on the upper surface of the ink separation layer 44 (see FIG. 5). Each of the electrodes 51 to 53 is formed by screen printing using a squeegee. In this case, bleeding is likely to occur at the downstream end of the squeegee in the moving direction, and the bleeding can be formed as thin-walled portions 51s, 52s, 53s (see FIG. 5).

For example, when forming the high potential electrode 52, as shown in FIG. 7, a mask 101 having holes 101x corresponding to the high potential electrode 52 is arranged on the upper surface of the piezoelectric layer 42, and the squeegee 100 is moved. The high potential electrode 52 is formed by screen printing. At this time, the squeegee 100 moves while holding the electrode material (for example, silver, nickel, gold, etc.) 110 on the downstream side in the moving direction D. When the material 110 enters the hole 101x, the high potential electrode 52 is formed. At this time, the material 110 flows into the downstream end of the high potential electrode 52 in the moving direction D, so that bleeding A is likely to occur. This bleeding A is formed as a thin-walled portion 52s.

As described above, the high potential electrode 52 has a thick portion 52t corresponding to the hole 101x of the mask 101 and a thin portion 52s located on the downstream side of the moving direction D with respect to the thick portion 52t. The thin portion 52s has a smaller thickness in the Z direction than the thick portion 52t.

The same applies to the drive electrode 51 and the low potential electrode 53, and as shown in FIG. 5, the thick portions 51t and 53t and the thin portions located downstream of the thick portions 51t and 53t in the moving direction D, respectively. It has 51s and 53s. The thin-walled portions 51s and 53s have a smaller thickness in the Z direction than the thick-walled portions 51t and 53t.

The thick portion 51t corresponds to the "first thick portion" of the present invention, and the thin portion 51s corresponds to the "first thin portion" of the present invention. The thick portion 52t corresponds to the "second thick portion" of the present invention, and the thin portion 52s corresponds to the "second thin portion" of the present invention. The thick portion 53t corresponds to the "33rd thick portion" of the present invention, and the thin portion 53s corresponds to the "third thin portion" of the present invention.

For example, the thickness of the thick portions 51t to 53t in the Z direction is about 1 μm, and the thickness of the thin portions 51s to 53s in the Z direction is 0.1 μm or less. The length of the thin portions 51s to 53s in the X direction is, for example, 10 to 100 μm, which is equal to or greater than the distance S between the second active portion 62 and the first active portion 61 in the X direction.

In the present embodiment, the moving direction D of the squeegee 100 when forming the drive electrode 51 is the direction from the other (right side in FIG. 5) to one side (left side in FIG. 5) in the X direction. Therefore, the thin portion 51s is located on one side (left side in FIG. 5) in the X direction with respect to the thick portion 51t.

The drive electrode 51 has one end 51x forming one end (left end in FIG. 5) of the second active portion 62 in the X direction and the other end (FIG. 5) of the third active portion 63 in the X direction. It has the other end 51y forming the right end of 5). The thin portion 51s is formed at one end 51x and not at the other end 51y. The thin portion 51s is arranged in a portion that does not overlap with the pressure chamber 10 in the Z direction.

The moving direction D of the squeegee 100 is the same for all the driving electrodes 51. Therefore, in all the drive electrodes 51, the thin portion 51s is arranged on the same side in the X direction with respect to the thick portion 51t.

When the high potential electrode 52 is formed, the moving direction D of the squeegee 100 is the direction from one (left side in FIG. 5) to the other (right side in FIG. 5) in the X direction. Therefore, the thin portion 52s is located on the other side (right side in FIG. 5) in the X direction with respect to the thick portion 52t.

The individual portion 52a of the high potential electrode 52 has one end 52ax forming one end (left end in FIG. 5) of the first active portion 61 in the X direction and the other end 52a of the first active portion 61 in the X direction. It has an other end 52ay forming an end portion (right end in FIG. 5). The thin portion 52s is formed at the other end 52ay and is not formed at one end 52ax.

The moving direction D of the squeegee 100 is the same in all the individual portions 52a. Therefore, for each of the plurality of drive electrodes 51, the thin-walled portion 52s is arranged on the same side in the X direction with respect to the thick-walled portion 52t.

When the low potential electrode 53 is formed, the moving direction D of the squeegee 100 is the direction from the other (right side in FIG. 5) to one (left side in FIG. 5) in the X direction. Therefore, the thin portion 53s is located on one side (left side in FIG. 5) in the X direction with respect to the thick portion 53t.

The individual portion 53a of the low potential electrode 53 has one end 53ax forming one end (left end in FIG. 5) of the third active portion 63 in the X direction and the other end 53a of the second active portion 62 in the X direction. It has an other end 53ay forming an end portion (right end in FIG. 5). The thin portion 53s is formed at one end 53ax and not at the other end 53ay.

The moving direction D of the squeegee 100 is the same in all the individual portions 53a. Therefore, for each of the plurality of drive electrodes 51, the thin-walled portion 53s is arranged on the same side in the X direction with respect to the thick-walled portion 53t.

In the present embodiment, as shown in FIG. 5, the end portion to which the thin-walled portion 52s of the thick-walled portion 52t of the individual portion 52a is connected and the end portion to which the thin-walled portion 53s of the thick-walled portion 53t of the individual portion 53a is connected are connected. , Are in the same position with each other in the X direction. The thick portion 52t and the thick portion 53t do not overlap each other in the Z direction and are adjacent to each other in the X direction. The thin portion 52s overlaps the thick portion 53t in the Z direction, and the thin portion 53s overlaps the thick portion 52t in the Z direction.

As described above, according to the piezoelectric actuator 22 of the present embodiment, in the individual portion 52a of the high potential electrode 52, the thin portion 52s is formed at the other end 52ay and not at one end 52ax (FIG. 5). reference). The method for manufacturing the piezoelectric actuator 22 of the present embodiment includes a step of moving the squeegee 100 from one side in the X direction toward the other side (right side in FIG. 5) and forming the high potential electrode 52 by screen printing. (See FIG. 7). When the thin portion 52s is formed at one end at 52ax, the first active portion 61 becomes longer in the direction approaching the second active portion 62. In this case, the second active portion 62 and the first active portion 61 are not separated from each other in the X direction, are adjacent to each other in the X direction, or overlap each other in the Z direction, so that the requirement (I) may not be satisfied. On the other hand, in the present embodiment, since the thin-walled portion 52s is formed at the other end 52ay and not formed at one end 52ax, the first active portion 61 does not become longer in the direction approaching the second active portion 62, which is the above requirement. (I) can be surely satisfied.

According to the piezoelectric actuator 22 of the present embodiment, in the individual portion 53a of the low potential electrode 53, the thin portion 53s is formed at one end 53ax and not at the other end 53ay (see FIG. 5). The method for manufacturing the piezoelectric actuator 22 of the present embodiment includes a step of moving the squeegee 100 from the other side in the X direction toward one side (left side in FIG. 5) and forming the low potential electrode 53 by screen printing. .. When the thin portion 53s is formed at the other end 53ay, the second active portion 62 becomes longer in the direction approaching the first active portion 61. In this case, the second active portion 62 and the first active portion 61 are not separated from each other in the X direction, are adjacent to each other in the X direction, or overlap each other in the Z direction, so that the requirement (I) may not be satisfied. On the other hand, in the present embodiment, since the thin-walled portion 53s is formed at one end 53ax and not at the other end 53ay, the second active portion 62 does not become longer in the direction approaching the first active portion 61, which is a requirement ( I) can be surely satisfied.

In a configuration that satisfies the requirement (II-a) [the requirement that the third active portion 63 overlaps the other end portion in the X direction (right end in FIG. 5) in the first active portion 61 in the Z direction], the thick portion 52t The 53ts are adjacent to each other in the X direction without overlapping in the Z direction, the thin portion 52s overlaps the thick portion 53t in the Z direction, and the thin portion 53s overlaps the thick portion 52t in the Z direction (see FIG. 5). .. When the thick portions 52t and 53t overlap each other in the Z direction, the rigidity of the portion increases, and the deformation of the actuator portion 60 can be hindered. On the other hand, in the present embodiment, since the thick portions 52t and 53t do not overlap each other in the Z direction, it is possible to suppress the increase in rigidity as described above and suppress the inhibition of deformation of the actuator portion 60.

In the drive electrode 51, the thin portion 51s is formed at one end 51x and not at the other end 51y (see FIG. 5). It is assumed that the piezoelectric actuator 22 of the present embodiment is fixed to the flow path unit 21 so that one end 51x does not overlap the pressure chamber 10 in the Z direction and the other end 51y overlaps the pressure chamber 10 in the Z direction. NS. In this case, if the thin portion 51s is formed at the other end 51y, the rigidity of the portion overlapping the pressure chamber 10 in the Z direction is increased, so that the deformation of the actuator portion 60 can be hindered. On the other hand, in the present embodiment, since the thin portion 51s is formed at one end 51x and not at the other end 51y, it is possible to suppress an increase in the rigidity of the portion overlapping the pressure chamber 10 in the Z direction, and the actuator portion. Inhibition of deformation of 60 can be suppressed.

The distance S between the second active portion 62 and the first active portion 61 in the X direction is equal to or less than the length of the thin portion 52s in the X direction (see FIG. 5). In this case, if the thin-walled portion 52s is formed at one end at 52ax, the interval S is filled with the thin-walled portion 52s, and there is a high possibility that the requirement (I) is not satisfied. However, in the present embodiment, since the thin portion 52s is formed not at one end 52ax but at the other end 52ay, the problem that the requirement (I) is not satisfied can be suppressed.

The distance S between the second active portion 62 and the first active portion 61 in the X direction is equal to or less than the length of the thin portion 53s in the X direction (see FIG. 5). In this case, if the thin-walled portion 53s is formed at the other end 53ay, the interval S is filled with the thin-walled portion 53s, and there is a high possibility that the requirement (I) is not satisfied. However, in the present embodiment, since the thin portion 53s is formed not at the other end 53ay but at one end 53ax, the problem that the requirement (I) is not satisfied can be suppressed.

The thin portion 52s is arranged on the same side of the thick portion 52t in the X direction (arrangement direction of the drive electrodes 51) with respect to each of the plurality of drive electrodes 51. In this case, in the plurality of actuator units 60 arranged in the X direction, the arrangement modes of the active units 61 to 63 are aligned. As a result, it is possible to suppress variations in deformation characteristics of the plurality of actuator units 60 arranged in the X direction.

For each of the plurality of drive electrodes 51, the thin portion 53s is arranged on the same side in the X direction (arrangement direction of the drive electrodes 51) with respect to the thick portion 53t. In this case, similarly to the above, in the plurality of actuator units 60 arranged in the X direction, the arrangement modes of the active units 61 to 63 are aligned. As a result, it is possible to suppress variations in deformation characteristics of the plurality of actuator units 60 arranged in the X direction.

<Second Embodiment>
Subsequently, the piezoelectric actuator 222 according to the second embodiment of the present invention will be described with reference to FIG.

In the first embodiment (FIG. 5), requirement (II-a) [requirement that the third active portion 63 overlaps the other end in the X direction (right end in FIG. 5) in the first active portion 61 in the Z direction]. In the configuration satisfying the above conditions, the thick portions 52t and 53t are adjacent to each other in the X direction without overlapping in the Z direction, the thin portion 52s overlaps the thick portion 53t and the Z direction, and the thin portion 53s overlaps the thick portions 52t and Z. It overlaps in the direction. On the other hand, in the second embodiment (FIG. 8), in the configuration satisfying the requirement (II-a), the thick portions 52t and 53t are separated from each other in the X direction, and the thin portion 52s and the thin portion 53s are separated from each other in the X direction. Between the thick portions 52t and 53t in the direction, they overlap each other in the Z direction.

In the present embodiment, as in the first embodiment, since the thick portions 52t and 53t do not overlap each other in the Z direction, it is possible to suppress the inhibition of deformation of the actuator portion 60. Further, in the present embodiment, by adopting a configuration in which the thin-walled portions 52s and 53s overlap each other in the Z direction, it is possible to more reliably suppress the increase in rigidity and further suppress the inhibition of deformation of the actuator portion 60.

<Third Embodiment>
Subsequently, the piezoelectric actuator 322 according to the third embodiment of the present invention will be described with reference to FIG. 9A.

In the first embodiment (FIG. 5), requirement (II-a) [requirement that the third active portion 63 overlaps the other end in the X direction (right end in FIG. 5) in the first active portion 61 in the Z direction]. The configuration that satisfies is adopted. On the other hand, in the third embodiment (FIG. 9 (a)), the requirement (II-b) [the third active portion 63 is the other end of the first active portion 61 in the X direction (of FIG. 9 (a)). A configuration that satisfies the requirement that it is adjacent to the right end in the X direction] is adopted. That is, in the third embodiment, the third active portion 63 does not have a portion that overlaps the first active portion 61 in the Z direction and is adjacent to the first active portion 61 in the X direction.

In the third embodiment (FIG. 9A), the positions of the high potential electrode 52 and the low potential electrode 53 in the Z direction are opposite to those in the first embodiment (FIG. 5). In the third embodiment (FIG. 9A), the driving electrode 51, the low potential electrode 53, and the high potential electrode 52 are arranged in this order from the top in the Z direction.

In the third embodiment (FIG. 9A), in the individual portion 52a of the high potential electrode 52, the thin-walled portion 52s is formed at the other end 52ay and is formed at one end 52ax, as in the first embodiment (FIG. 5). It has not been. In the individual portion 53a of the low potential electrode 53, the thin-walled portion 53s is formed at one end 53ax and not at the other end 53ay.

In the third embodiment (FIG. 9A), the thick portions 52t and 53t do not overlap in the Z direction but are separated in the X direction. The thin portions 52s and 53s do not overlap in the Z direction and are adjacent to each other in the X direction.

In the third embodiment (FIG. 9A), when the thin portion 52s is formed at one end at 52ax, the first active portion 61 becomes longer in the direction approaching the second active portion 62. In this case, the second active portion 62 and the first active portion 61 are not separated from each other in the X direction, are adjacent to each other in the X direction, or overlap each other in the Z direction, so that the requirement (I) may not be satisfied. On the other hand, in the third embodiment, since the thin-walled portion 52s is formed at the other end 52ay and not formed at one end 52ax, the first active portion 61 does not become longer in the direction approaching the second active portion 62, as described above. The requirement (I) can be surely satisfied.

Further, when the thin portion 53s is formed at the other end 53ay, the second active portion 62 becomes longer in the direction approaching the first active portion 61. In this case, the second active portion 62 and the first active portion 61 are not separated from each other in the X direction, are adjacent to each other in the X direction, or overlap each other in the Z direction, so that the requirement (I) may not be satisfied. On the other hand, in the third embodiment, since the thin-walled portion 53s is formed at one end 53ax and not at the other end 53ay, the second active portion 62 does not become longer in the direction approaching the first active portion 61, which is a requirement. (I) can be surely satisfied.

<Fourth Embodiment>
Subsequently, the piezoelectric actuator 422 according to the fourth embodiment of the present invention will be described with reference to FIG. 9B.

In the fourth embodiment (FIG. 9 (b)), as in the third embodiment (FIG. 9 (a)), the requirement (II-b) [the third active portion 63 is the other in the X direction in the first active portion 61. The configuration that satisfies the requirement that the end portion (the right end of FIG. 9B) is adjacent to the end portion in the X direction] is adopted. That is, in the fourth embodiment (FIG. 9 (b)), as in the third embodiment (FIG. 9 (a)), the third active portion 63 has a portion that overlaps with the first active portion 61 in the Z direction. Instead, it is adjacent to the first active portion 61 in the X direction.

In the fourth embodiment (FIG. 9 (b)), the positions of the drive electrode 51 and the high potential electrode 52 in the Z direction are opposite to those in the first embodiment (FIG. 5). In the fourth embodiment (FIG. 9B), the high potential electrode 52, the driving electrode 51, and the low potential electrode 53 are arranged in this order from the top in the Z direction.

In the fourth embodiment (FIG. 9B), in the individual portion 52a of the high potential electrode 52, the thin-walled portion 52s is formed at the other end 52ay and is formed at one end 52ax, as in the first embodiment (FIG. 5). It has not been. In the individual portion 53a of the low potential electrode 53, the thin-walled portion 53s is formed at one end 53ax and not at the other end 53ay.

In the fourth embodiment (FIG. 9 (b)), as in the third embodiment (FIG. 9 (a)), the thick portions 52t and 53t do not overlap in the Z direction and are separated in the X direction. .. The thin portions 52s and 53s do not overlap in the Z direction and are adjacent to each other in the X direction.

In the fourth embodiment (FIG. 9B), when the thin portion 52s is formed at one end at 52ax, the first active portion 61 becomes longer in the direction approaching the second active portion 62. In this case, the second active portion 62 and the first active portion 61 are not separated from each other in the X direction, are adjacent to each other in the X direction, or overlap each other in the Z direction, so that the requirement (I) may not be satisfied. On the other hand, in the fourth embodiment, since the thin-walled portion 52s is formed at the other end 52ay and not formed at one end 52ax, the first active portion 61 does not become longer in the direction approaching the second active portion 62, as described above. The requirement (I) can be surely satisfied.

Further, when the thin portion 53s is formed at the other end 53ay, the second active portion 62 becomes longer in the direction approaching the first active portion 61. In this case, the second active portion 62 and the first active portion 61 are not separated from each other in the X direction, are adjacent to each other in the X direction, or overlap each other in the Z direction, so that the requirement (I) may not be satisfied. On the other hand, in the fourth embodiment, since the thin-walled portion 53s is formed at one end 53ax and not at the other end 53ay, the second active portion 62 does not become longer in the direction approaching the first active portion 61, which is a requirement. (I) can be surely satisfied.

<Fifth Embodiment>
Subsequently, the piezoelectric actuator 522 according to the fifth embodiment of the present invention will be described with reference to FIG. 9 (c).

In the first embodiment (FIG. 5), requirement (II-a) [requirement that the third active portion 63 overlaps the other end in the X direction (right end in FIG. 5) in the first active portion 61 in the Z direction]. The configuration that satisfies is adopted. On the other hand, in the fifth embodiment (FIG. 9 (c)), the requirement (II-c) [the third active portion 63 is separated from the first active portion 61 to the other in the X direction, and the third active portion is separated. The requirement that the distance S1 between the 63 and the first active unit 61 in the X direction is shorter than the distance S2 between the second active unit 62 and the first active unit 61 in the X direction] is adopted. In the fifth embodiment (FIG. 9 (c)), the third active portion 63 does not have a portion overlapping the first active portion 61 in the Z direction and is separated from the first active portion 61 in the X direction.

In the fifth embodiment (FIG. 9 (c)), the lowermost piezoelectric layer 43 in the first embodiment (FIG. 5) is omitted, and the piezoelectric body 40 has two piezoelectric layers 41 laminated in the Z direction. , 42.

In the fifth embodiment (FIG. 9 (c)), in the individual portion 52a of the high potential electrode 52, the thin-walled portion 52s is formed at the other end 52ay and is formed at one end 52ax, as in the first embodiment (FIG. 5). It has not been. In the individual portion 53a of the low potential electrode 53, the thin-walled portion 53s is formed at one end 53ax and not at the other end 53ay.

In the fifth embodiment (FIG. 9 (c)), the thick portions 52t and 53t do not overlap in the Z direction but are separated in the X direction. The thin portions 52s and 53s do not overlap in the Z direction and are separated in the X direction.

In the fifth embodiment (FIG. 9 (c)), when the thin portion 52s is formed at one end at 52ax, the first active portion 61 becomes longer in the direction approaching the second active portion 62. In this case, the second active portion 62 and the first active portion 61 are not separated from each other in the X direction, are adjacent to each other in the X direction, or overlap each other in the Z direction, so that the requirement (I) may not be satisfied. On the other hand, in the fifth embodiment, since the thin-walled portion 52s is formed at the other end 52ay and not formed at one end 52ax, the first active portion 61 does not become longer in the direction approaching the second active portion 62, as described above. The requirement (I) can be surely satisfied.

Further, when the thin portion 53s is formed at the other end 53ay, the second active portion 62 becomes longer in the direction approaching the first active portion 61. In this case, the second active portion 62 and the first active portion 61 are not separated from each other in the X direction, are adjacent to each other in the X direction, or overlap each other in the Z direction, so that the requirement (I) may not be satisfied. On the other hand, in the fifth embodiment, since the thin-walled portion 53s is formed at one end 53ax and not at the other end 53ay, the second active portion 62 does not become longer in the direction approaching the first active portion 61, which is a requirement. (I) can be surely satisfied.

<Modification example>
Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as it is described in the claims.

In the first embodiment, the moving direction D of the squeegee 100 when forming the drive electrode 51 is the same for all the drive electrodes 51, but is not limited to this (the same applies to the high potential electrode 52 and the low potential electrode 53). ). For example, the moving direction of the squeegee 100 may be different for each row of electrodes 51 to 53 (row corresponding to the pressure chamber row 9 shown in FIG. 2). Even in this case, a plurality of thin portions 51 to 53s and thick portions 51t to 53t arranged in the row are arranged in the X direction by aligning the positional relationships and the arrangement modes of the active portions 61 to 63. It is possible to suppress variations in deformation characteristics of the actuator unit 60.

The distance between the second active portion 62 and the first active portion 61 in the second direction (interval S in FIG. 5) is the second direction of the thin-walled portion 52s (second thin-walled portion) and the thin-walled portion 53s (third thin-walled portion). May exceed the length of.

In the piezoelectric actuator according to the present invention, "the second thin-walled portion is formed at the other end of the second electrode and not at one end of the second electrode" and "the third thin-walled portion is formed at one end of the third electrode". It is sufficient to satisfy at least one of "they are formed in the above and not formed at the other end of the third electrode", and the present invention is not limited to both.

The first active portion may include a portion that does not overlap the pressure chamber in the first direction.

The positions of the first to third electrodes in the third direction can be arbitrarily changed as shown in FIGS. 9A to 9C.

The ink separation layer 44 (see FIG. 5) may be omitted.

The present invention is not limited to printers, and can be applied to facsimiles, copiers, multifunction devices, and the like. The present invention is also applicable to a liquid discharge device used for purposes other than image recording (for example, a liquid discharge device that discharges a conductive liquid onto a substrate to form a conductive pattern). Further, the piezoelectric actuator according to the present invention can be applied to any device other than the liquid discharge device.

22; 222; 322; 422; 522 Piezoelectric actuator 40 Piezoelectric body 41-43 Piezoelectric layer 51 Drive electrode (first electrode)
51x one end 51y other end 51t thick part (first thick part)
51s thin-walled part (first thin-walled part)
52 High potential electrode (second electrode)
52ax one end 52ay other end 52t thick part (second thick part)
52s thin wall part (second thin wall part)
53 Low potential electrode (third electrode)
53ax one end 53ay other end 53t thick part (third thick part)
53s thin-walled part (third thin-walled part)
60 Actuator part 61 1st active part 62 2nd active part 63 3rd active part 100 Squeegee

Claims (13)

A piezoelectric body having a plurality of piezoelectric layers laminated in the first direction,
With the first electrode
With the second electrode separated from the first electrode in the first direction,
A piezoelectric actuator comprising a third electrode separated from the first electrode in the first direction.
The piezoelectric body has a first active portion sandwiched between the first electrode and the second electrode in the first direction, and a first active portion sandwiched between the first electrode and the third electrode in the first direction. The two active parts and the third active part sandwiched between the first electrode and the third electrode in the first direction, and separated from the second active part in the second direction orthogonal to the first direction. The first active portion has a portion arranged between the second active portion and the third active portion in the second direction.
The second active part is separated from the first active part in one of the second directions.
The third active part is located at any of the following positions (a) to (c).
(A) Position of the first active portion that overlaps the other end of the second direction in the first direction (b) In the first active portion of the other end of the second direction and in the second direction Adjacent position (c) The first active portion is separated from the other in the second direction, and the distance between the third active portion and the first active portion in the second direction is the distance between the second active portion and the second active portion. A position shorter than the distance between the first active portion and the first active portion in the second direction. The second electrode has a second thick portion and a second thin wall having a thickness smaller than that of the second thick portion in the first direction. With a part,
In the second direction, the second electrode forms one end of the first active portion in the second direction and the other end of the first active portion in the second direction. With the other end,
A piezoelectric actuator characterized in that the second thin-walled portion is formed at the other end of the second electrode and is not formed at the one end of the second electrode. The third electrode has a third thick portion and a third thin portion having a thickness smaller in the first direction than the third thick portion.
In the second direction, the third electrode forms one end of the third active portion in the second direction and the other end of the second active portion in the second direction. With the other end,
The piezoelectric actuator according to claim 1, wherein the third thin-walled portion is formed at one end of the third electrode and not at the other end of the third electrode. A piezoelectric body having a plurality of piezoelectric layers laminated in the first direction,
With the first electrode
With the second electrode separated from the first electrode in the first direction,
A piezoelectric actuator comprising a third electrode separated from the first electrode in the first direction.
The piezoelectric body has a first active portion sandwiched between the first electrode and the second electrode in the first direction, and a first active portion sandwiched between the first electrode and the third electrode in the first direction. The two active parts and the third active part sandwiched between the first electrode and the third electrode in the first direction, and separated from the second active part in the second direction orthogonal to the first direction. The first active portion has a portion arranged between the second active portion and the third active portion in the second direction.
The second active part is separated from the first active part in one of the second directions.
The third active part is located at any of the following positions (a) to (c).
(A) Position of the first active portion that overlaps the other end of the second direction in the first direction (b) In the first active portion of the other end of the second direction and in the second direction Adjacent position (c) The first active portion is separated from the other in the second direction, and the distance between the third active portion and the first active portion in the second direction is the distance between the second active portion and the second active portion. A position shorter than the distance between the first active portion and the first active portion in the second direction. The third electrode has a third thick portion and a third thin wall having a thickness smaller than that of the third thick portion in the first direction. With a part,
In the second direction, the third electrode forms one end of the third active portion in the second direction and the other end of the second active portion in the second direction. With the other end,
A piezoelectric actuator characterized in that the third thin-walled portion is formed at one end of the third electrode and not at the other end of the third electrode. The second electrode has a second thick portion and a second thin portion having a thickness smaller in the first direction than the second thick portion.
In the second direction, the second electrode forms one end of the first active portion in the second direction and the other end of the first active portion in the second direction. With the other end,
The piezoelectric actuator according to claim 3, wherein the second thin-walled portion is formed at the other end of the second electrode and is not formed at the one end of the second electrode. The third active part is
(A) At a position overlapping the other end of the first active portion in the second direction in the first direction.
The second thick portion and the third thick portion do not overlap each other in the first direction and are adjacent to each other in the second direction.
The second thin-walled portion overlaps with the third thick-walled portion in the first direction.
The piezoelectric actuator according to claim 2 or 4, wherein the third thin-walled portion overlaps the second thick-walled portion in the first direction. The third active part is
(A) At a position overlapping the other end of the first active portion in the second direction in the first direction.
The second thick portion and the third thick portion are separated from each other in the second direction.
The second thin-walled portion and the third thin-walled portion overlap each other in the first direction between the second thick-walled portion and the third thick-walled portion in the second direction. The piezoelectric actuator according to claim 2 or 4. The first electrode has a first thick portion and a first thin portion having a thickness smaller in the first direction than the first thick portion.
In the second direction, the first electrode forms one end of the second active portion in the second direction and the other end of the third active portion in the second direction. With the other end,
The first thin-walled portion according to any one of claims 1 to 6, wherein the first thin-walled portion is formed at one end of the first electrode and not at the other end of the first electrode. Piezoelectric actuator. Claims 1, 2, and 4, wherein the distance between the second active portion and the first active portion in the second direction is equal to or less than the length of the second thin-walled portion in the second direction. 5. The piezoelectric actuator according to any one of 5 and 6. Claims 2, 3, and 4, wherein the distance between the second active portion and the first active portion in the second direction is equal to or less than the length of the third thin-walled portion in the second direction. 5. The piezoelectric actuator according to any one of 5 and 6. A plurality of the first electrodes are arranged in the second direction, and the plurality of first electrodes are arranged in the second direction.
Claims 1, 2 and 1, wherein the second thin-walled portion is arranged on the same side of the second thick portion with respect to each of the plurality of first electrodes. 4. The piezoelectric actuator according to any one of 4, 5, 6 and 8. A plurality of the first electrodes are arranged in the second direction, and the plurality of first electrodes are arranged in the second direction.
The third thin portion is arranged on the same side in the second direction with respect to the third thick portion with respect to each of the plurality of first electrodes. 4. The piezoelectric actuator according to any one of 4, 5, 6 and 9. A piezoelectric body having a plurality of piezoelectric layers laminated in the first direction, a first electrode, a second electrode separated from the first electrode in the first direction, and a separation from the first electrode in the first direction. This is a method for manufacturing a piezoelectric actuator provided with a third electrode.
The piezoelectric body has a first active portion sandwiched between the first electrode and the second electrode in the first direction, and a first active portion sandwiched between the first electrode and the third electrode in the first direction. The two active parts and the third active part sandwiched between the first electrode and the third electrode in the first direction, and separated from the second active part in the second direction orthogonal to the first direction. The first active portion has a portion arranged between the second active portion and the third active portion in the second direction.
The second active part is separated from the first active part in one of the second directions.
The third active part is located at any of the following positions (a) to (c).
(A) Position of the first active portion that overlaps the other end of the second direction in the first direction (b) In the first active portion of the other end of the second direction and in the second direction Adjacent position (c) The first active part is separated from the other in the second direction, and the distance between the third active part and the first active part in the second direction is the distance between the second active part and the second active part. A position shorter than the distance from the first active portion in the second direction The second electrode is provided with a step of moving the squeegee from one of the second directions toward the other and forming the second electrode by screen printing. A method for manufacturing a piezoelectric actuator. A piezoelectric body having a plurality of piezoelectric layers laminated in the first direction, a first electrode, a second electrode separated from the first electrode in the first direction, and a separation from the first electrode in the first direction. This is a method for manufacturing a piezoelectric actuator provided with a third electrode.
The piezoelectric body has a first active portion sandwiched between the first electrode and the second electrode in the first direction, and a first active portion sandwiched between the first electrode and the third electrode in the first direction. The two active parts and the third active part sandwiched between the first electrode and the third electrode in the first direction, and separated from the second active part in the second direction orthogonal to the first direction. The first active portion has a portion arranged between the second active portion and the third active portion in the second direction.
The second active part is separated from the first active part in one of the second directions.
The third active part is located at any of the following positions (a) to (c).
(A) Position of the first active portion that overlaps the other end of the second direction in the first direction (b) In the first active portion of the other end of the second direction and in the second direction Adjacent position (c) The first active part is separated from the other in the second direction, and the distance between the third active part and the first active part in the second direction is the distance between the second active part and the second active part. A position shorter than the distance from the first active portion in the second direction The third electrode is provided with a step of moving the squeegee from the other in the second direction toward one side and forming the third electrode by screen printing. A method for manufacturing a piezoelectric actuator.

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