JP2001328267A - Ink-jet recording head, piezoelectric vibrator unit used in the same, and method for manufacturing piezoelectric vibrator unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording head having a piezoelectric vibrator unit positioned with a high accuracy. SOLUTION: Dummy vibrators 7 and 7 are set to at least one end in an arrangement direction of piezoelectric vibrators. Moreover, regions near external side faces of the dummy piezoelectric vibrators 7 and 7 are formed only of a piezoelectric material. A cutting line is thus prevented as much as possible from being deviated by the high hardness of internal electrodes when the external side faces of the dummy piezoelectric vibrators 7 and 7 are cut.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head using, as a pressure generating means, a longitudinal vibration mode piezoelectric vibrator in which a plurality of internal electrodes are alternately laminated with a piezoelectric material interposed therebetween.

[0002]

2. Description of the Related Art In an ink jet recording head using a piezoelectric vibrator in a longitudinal vibration mode, a plurality of pressure generating chambers are arranged in the same row, each communicating with a nozzle opening, and a part thereof is sealed by a plate material capable of being elastically deformed. The pressure generating chamber is configured to be expanded and contracted by individual piezoelectric vibrators which are displaced in the axial direction in accordance with the drive signal, thereby ejecting ink droplets.

As shown in FIG. 15, such a piezoelectric vibrator includes a plurality of piezoelectric vibrating plates having a size corresponding to a plurality of piezoelectric vibrating plates.
The piezoelectric vibrator 61 is configured as a unit in which a plurality of piezoelectric vibrators 61 are fixed to 0, and are bladed at a constant pitch by a wire saw or the like.

In order to enhance the workability of the alignment at the time of assembling, dummy piezoelectric vibrators 62 and 63 which are not involved in ink droplets are formed on both sides in the row direction, and the outside of the dummy piezoelectric vibrators 62 and 63 is formed. Each piezoelectric vibrator 61 is positioned within a predetermined tolerance with respect to the flow path unit by setting the side surfaces 62 'and 63' in a case with reference to the case.

[0005]

However, since the piezoelectric vibrating plate is formed by laminating a plurality of layers of the internal electrode forming material including metal and the piezoelectric material, and firing them, the piezoelectric vibrating plate is required to be cut by a wire saw. Due to the high hardness of the internal electrodes 64 and 65, a slight shift occurs in the cutting line. This shift greatly affects the relative positioning accuracy of the piezoelectric vibrator unit when the area of the tip of the piezoelectric vibrator is reduced in order to improve the printing density. The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ink jet recording head in which a piezoelectric vibrator is positioned at a predetermined position with high accuracy. Another object of the present invention is to provide a piezoelectric vibrator unit having high shape accuracy. A third object of the present invention is to propose a method for manufacturing a piezoelectric vibrator unit.

[0006]

According to the present invention, a plurality of piezoelectric vibrators extending in the axial direction by alternately laminating piezoelectric materials and internal electrodes are arranged on the same substrate. A piezoelectric vibrator unit, wherein the volume of the pressure generating chamber is expanded and reduced by the piezoelectric vibrator, and a dummy vibrator is arranged at at least one end in the row direction of the piezoelectric vibrators. A region where no internal electrode is provided is provided near the outer side surface of the dummy piezoelectric vibrator.

[0007]

[Function] Since there is no internal electrode in the region near the outer side surface of the dummy piezoelectric vibrator, when the outer side surface of the dummy piezoelectric vibrator is cut out, deviation of the cutting line due to the high hardness of the internal electrode is possible. And high precision cutting is possible.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. FIG. 1 shows an embodiment of the present invention. A piezoelectric vibrator unit 1 according to the present invention includes an internal electrode 2 having different poles parallel to an axial direction.
The piezoelectric vibrators 5 are laminated with a piezoelectric material 4 interposed therebetween so as to expose one end of each of the piezoelectric vibrators 3 and wrap in the vibrating region.
4 are arranged on the fixed substrate 6 at a constant pitch as shown in FIG. 4, and dummy piezoelectric vibrators 7, 7 are disposed at the ends of the piezoelectric vibrators in the row direction. Then, debris 7 ′, 7 ′ at the time of forming the dummy piezoelectric vibrators 7, 7 adhere to the outside of the dummy piezoelectric vibrators 7, 7.

[0010] As shown in FIG. 2, the dummy piezoelectric vibrator has no electrodes on its outer side surface, and is formed of only the piezoelectric material 4. From the exposed surfaces of the internal electrodes 2 and 3 at the front and rear ends of each piezoelectric vibrator 5 to the front side of the fixed substrate 6, external electrodes 9 and 10 forming connection portions with a flexible cable 8 for supplying a drive signal are provided. It is formed by vapor deposition or sputtering.

The flow path forming unit 11 includes a reservoir 12,
A flow path forming substrate 15 that partitions and forms the ink supply port 13 and the pressure generating chamber 14, and an elastic plate 16 that abuts against the tip of the piezoelectric vibrator 5 to expand and reduce the volume of the pressure generating chamber 14.
And a nozzle opening 1 for sealing the other surface of the flow path forming substrate 15 and discharging the ink in the pressure generating chamber 14 as ink droplets.
And a nozzle plate 18 provided with the nozzle 7.

The flow path forming unit 11 includes the head holder 1
The piezoelectric vibrator unit 1 is fixed to the opening surface 19a of the piezoelectric vibrator 9 and the elastic plate 1
6, the fixed substrate 6 and the head holder 19 are fixed by an adhesive to form an ink jet recording head. Piezoelectric vibrator unit 11
As shown in FIG. 3, the side surfaces of the dummy piezoelectric vibrators located on both sides are in contact with the inner wall surface 19b of the piezoelectric vibrator accommodating chamber of the head holder 19, and the position thereof is regulated.

In this embodiment, when a drive signal is applied to the piezoelectric vibrator 5 facing the pressure generating chamber 14 communicating with the nozzle opening 17 from which ink droplets are to be ejected, the piezoelectric vibrator 5 contracts and expands, and The generation chamber 14 is expanded and contracted. As a result, the ink in the reservoir 12 is
3 flows into the pressure generating chamber 14, and then the ink in the pressure generating chamber 14 is pressurized and discharged from the nozzle opening 17 as an ink droplet.

FIGS. 5 to 7 show such a piezoelectric vibrator 5.
An example is shown in the manufacturing method of the present invention, wherein the width W1 is slightly larger than the width W1 of the piezoelectric vibrator of the piezoelectric vibrator unit and the dummy piezoelectric vibrator on the surface plate 20 having a flat surface.
Then, a green sheet 21 made of a piezoelectric material pre-formed to a thickness of each layer is placed (FIG. 5 (I)).

On the surface thereof, the conductive layer 2 of one of the internal electrodes 3 is formed.
2 is formed using a mask having a pattern with a width W3 inside the side surface of the dummy piezoelectric vibrator and outside the adjacent piezoelectric vibrator (FIG. 5 (II)). Green sheets 21 of the same size piezoelectric material are stacked (FIG. 5 (III)).

The conductive layer 23 forming the internal electrode 4 serving as the other pole is provided with a mask provided with a pattern having a width W3 'inside the side surface of the dummy piezoelectric vibrator and outside the adjacent piezoelectric vibrator. (FIG. 6 (I)), and a green sheet 21 made of a piezoelectric material having the same size as that described above is laminated (FIG. 6 (II)).

Hereinafter, such a process is repeated by the number of layers to be formed (FIG. 6 (III)). The green sheet is dried and fired to form an external electrode on the surface to be an electrode for connection with a flexible cable. 24 and 25 are formed by sputtering or vapor deposition, and a voltage is applied to the electrodes 24 and 25 to perform a predetermined polarization process to form the piezoelectric material plate 27. The non-vibration area of the piezoelectric material plate 27 is positioned on the fixed substrate 28 and fixed with an adhesive (FIG. 7 (I)).

The width of the piezoelectric vibrator of the dummy 7 and the width of the driving piezoelectric vibrator 5 are set by using a cutting tool such as a wire saw so that the cutting lines on both sides are located outside the conductive layers 21 and 23. Split the teeth so that they match. In this cutting step, since the outermost cutting lines C, C are located in a region formed by only the piezoelectric material 21 without the conductive layers 21, 23 (FIG. 8), the conductive layers 21, 23 are formed. Slip does not occur due to the influence of the metal material to be cut, and the cutting proceeds smoothly. For this reason, cutting can be performed at a cutting plane that matches the intended cutting line.

Finally, the uncut portion 29 located on the outermost side,
After removing 29, the piezoelectric vibrator unit is completed (FIG. 7 (III)). Of course, since the conductive layers 21 and 23 do not exist here, the strength is relatively low, and it can be easily folded.

In the above-described embodiment, the electrodes 24 and 25 for external connection are formed to have a full width, but a dummy driving piezoelectric vibrator should be formed as shown in FIG. When formed in the region and recessed by the width W4 from the outermost cutting lines C and C to the inside by a width W4, the influence of the hardness of the external connection electrodes 24 and 25 is eliminated during the tooth splitting process, so that it is even more smooth. Can be cut into

In the above-described embodiment, the piezoelectric vibrating plate is formed to have a size capable of forming a single piezoelectric vibrator unit. In this case, a region in which the above-described internal electrode is not formed may be provided at a boundary for dividing into individual piezoelectric vibrator units.

FIG. 10 shows an embodiment of a piezoelectric vibrator unit having a piezoelectric constant d33 in which internal electrodes are formed in parallel with the laminating direction. The driving piezoelectric vibrators 33 laminated with the piezoelectric material 32 (FIG. 10B) interposed therebetween so as to be wrapped in the vibrating region so as to be exposed at a constant pitch on the fixed substrate 34, At the end of the 33 in the row direction,
Dummy piezoelectric vibrators 35 are arranged. Outside the dummy piezoelectric vibrators 35, 35, debris 35 ', 35' at the time of forming the dummy piezoelectric vibrators 35, 35 are provided.
Is attached.

Also in this embodiment, the width W5 from the both sides of the piezoelectric vibrating plate to be cleaved to the inside of the slits S formed for cutting out the dummy piezoelectric vibrators 35, 35 is shown in FIG. As shown in (a), there is no electrode in the region on the outer side surface, and the region is formed only of the piezoelectric material 32.

In the above embodiment, the internal electrodes are not formed for the dummy piezoelectric vibrator. However, as shown in FIG. 11, the dummy piezoelectric vibrator 7 '
For internal electrodes 3 ′ and 4 ′ only in the region D to be cut.
Is not present, the region to be cut off, that is, the region above the region D can be reinforced by the internal electrode 37,
The piezoelectric vibrating plate can be reliably folded at a target position, the thickness of the entire piezoelectric vibrating plate can be made as uniform as possible, and distortion and warpage during firing can be minimized.

In the above-described embodiment, the recording head in which the ink-sealed channel unit expands and contracts from the outside has been described. However, as shown in FIG. The present invention can be similarly applied to a Saar type ink jet recording head using the space 41 as a pressure generating chamber.

That is, the piezoelectric vibrator 4 located on the outermost side
By forming a region of only the piezoelectric material 43 where the internal electrode 42 does not exist in the side region of 0 'and setting a cutting line C in a region W6 formed only of the piezoelectric material 43, the entire width can be accurately determined. Can be specified.

FIG. 13 shows another embodiment of the piezoelectric vibrator unit according to the present invention in the manufacturing process. In this embodiment, a dummy piezoelectric vibrator comprises a piezoelectric vibrating plate and a second piezoelectric vibrating plate. It is configured by combining members.

That is, on both sides of the piezoelectric vibrating plate 27 on the surface of which the external electrodes 24 and 25 serving as electrodes for connection to the flexible cable are formed, the thickness is slightly smaller by ΔG1 than the thickness of the piezoelectric vibrating plate 27 and the front end surface A block 50 made of ceramic such as alumina or a metal such as non-rusting steel is fixed via an adhesive layer so as to be slightly closer to the fixed substrate 28 by ΔG2. The surface of the block 50 facing the fixed substrate 28 is also fixed via an adhesive layer (FIG. 13 (I)).

When the block 50 is made of a conductive material, it is preferable that the internal electrodes of the piezoelectric vibrating plate 27 are not exposed on the side surfaces as in the above-described embodiment.

In this state, the polarization process is performed by bringing the electrodes for applying the polarization voltage having an area at least capable of covering the piezoelectric vibration plate 27 into contact with the connection electrodes 24 and 25. At this time, since the block 50 is thinner than the piezoelectric diaphragm 27,
The polarization voltage applying electrode surely contacts the piezoelectric vibration plate 27.

After the polarization process is completed, the cutting lines C, C on both sides are set so as to be positioned in the block 50 by a cutting tool such as a wire saw, and the width of the dummy piezoelectric vibrator 7 'and the driving piezoelectric The teeth are split so as to match the width of the vibrator 5 (FIG. 13 (II)). In this cutting step, block 5
Since 0 is made of a single material, cutting proceeds smoothly, and cutting can be performed at a cutting plane that matches the intended cutting line.

Finally, the uncut portion 5 located on the side most side
When 0 'and 50' are removed, the piezoelectric vibrator unit is completed (FIG. 13 (III)). Of course, since it is a single material, it can be broken off relatively easily.

Since the dummy piezoelectric vibrator 7 'of the completed piezoelectric vibrator unit is defined by the piezoelectric vibrating plate 27 whose tip position is formed with high precision, the position of the dummy piezoelectric vibrator 7' is higher than the flow path unit. Since the positioning can be performed with high accuracy, and the dummy piezoelectric vibrator 7 ′ is reinforced by the block 50 having higher toughness than the piezoelectric material, the dummy piezoelectric vibrator 7 ′ is inserted into the head holder so that the outer surface of the block 50 is used as a reference. In addition, it is possible to prevent breakage sufficiently against external force during the assembling process.

In the above-described embodiment, the case where the block is provided on the piezoelectric vibrating plate having the piezoelectric constant d31 has been described. However, when the piezoelectric vibrator is cut out from the piezoelectric vibrating plate having the piezoelectric constant d33, a dummy piezoelectric vibrator is cut out. Obviously, the same effect is achieved even when applied to the formation of a vibrator.

[0034]

As described above, in the present invention,
A dummy vibrator was arranged at at least one end in the direction in which the piezoelectric vibrators were arranged, and a region in which no internal electrode was present was provided in a region near the outer side surface of the dummy piezoelectric vibrator. When cutting out the side surface, the deviation of the cutting line due to the high hardness of the internal electrode is small, the shape can be adjusted with high accuracy, and the piezoelectric vibrator unit is high using the dummy piezoelectric vibrator as the positioning reference body Positioning can be performed with accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of an ink jet recording head of the present invention by a cross-sectional structure in a region of a driving piezoelectric vibrator.

FIG. 2 is a diagram showing a cross-sectional structure in a region of a dummy piezoelectric vibrator of the recording head.

FIG. 3 is a diagram showing an assembling structure of the piezoelectric vibrator unit and the head holder.

FIG. 4 is a perspective view showing an embodiment of the piezoelectric vibrator unit according to the embodiment.

FIGS. 5 (I) to (III) are diagrams showing the first half of a method for manufacturing a piezoelectric vibrating plate in the method for manufacturing a piezoelectric vibrator unit according to the first embodiment.

FIGS. 6 (I) to (III) are views showing the latter half of the method of manufacturing the piezoelectric vibrating plate in the method of manufacturing the piezoelectric vibrator unit.

FIGS. 7 (I) to (III) are diagrams showing steps of forming a piezoelectric vibrator using a piezoelectric vibrating plate in the method of manufacturing the piezoelectric vibrator unit of the above.

FIG. 8 is a diagram showing a sectional structure of a cutting region of a dummy piezoelectric vibrator.

FIG. 9 is a view showing another embodiment of the piezoelectric vibration substrate.

FIGS. 10A and 10B are diagrams showing another embodiment of the ink jet recording head according to the present invention, showing a cross-sectional structure of a piezoelectric vibrator unit and a driving piezoelectric vibrator.

FIG. 11 is a perspective view showing another embodiment of the piezoelectric vibrator unit of the present invention.

FIG. 12 is a diagram showing an example of application to a recording head in which a pressure generating chamber is formed by a piezoelectric vibrator.

FIGS. 13 (I) to (III) are views showing another embodiment of the piezoelectric vibrator unit of the present invention in the manufacturing process.

FIG. 14 is an enlarged view showing a region E in FIG. 13;

FIG. 15 is a diagram showing an example of a piezoelectric vibrator unit used in a conventional ink jet recording head.

[Explanation of symbols]

 Reference Signs List 1 piezoelectric vibrator unit 2 internal electrode of one pole 3 internal electrode of the other pole 4 piezoelectric material 5 piezoelectric vibrator 6 fixed substrate 7 dummy piezoelectric vibrator 11 flow path forming unit C cutting line

Claims (31)

[Claims] 1. A piezoelectric vibrator unit in which a plurality of piezoelectric vibrators extending in the axial direction by alternately laminating piezoelectric materials and internal electrodes are arranged on the same substrate, and a volume of a pressure generating chamber is formed by the piezoelectric vibrators. In the ink jet recording head, which expands and contracts, a dummy vibrator is arranged at at least one end in the direction in which the piezoelectric vibrators are arranged, and an internal electrode exists near an outer side surface of the dummy piezoelectric vibrator. An ink jet recording head in which an area not to be formed is formed. 2. The ink jet recording head according to claim 1, wherein the vicinity of the outer side surface of the dummy piezoelectric vibrator is formed only of the piezoelectric material. 3. A piezoelectric material in which the piezoelectric vibrator exposes a first internal electrode and a second internal electrode of different poles parallel to each other in an axial direction only at respective end faces, and wraps in a vibration region. 2. The ink jet recording head according to claim 1, wherein the ink jet recording head is formed as a piezoelectric vibrator having a piezoelectric constant d31 laminated with interposing. 4. The piezoelectric vibrator exposes a first internal electrode and a second internal electrode of different poles orthogonal to each other in an axial direction only on one side, and wraps the piezoelectric vibrator in a vibrating region. 2. The ink jet recording head according to claim 1, wherein the ink jet recording head is formed as a piezoelectric vibrator having a piezoelectric constant d33 laminated by interposing a material. 5. The ink jet recording head according to claim 1, wherein a broken piece exists outside the dummy piezoelectric vibrator. 6. An external electrode which is electrically connected to each of said internal electrodes and connected to a signal supply means.
3. The ink jet recording head according to item 1. 7. The ink jet recording head according to claim 6, wherein an external electrode formed on the dummy piezoelectric vibrator is narrower than a width of the dummy piezoelectric vibrator. 8. The method according to claim 1, wherein the piezoelectric vibrator unit comprises a reservoir,
A flow path forming substrate that partitions and forms the ink supply port and the pressure generating chamber; an elastic plate that abuts on the tip of the piezoelectric vibrator to expand and contract the volume of the pressure generating chamber; The dummy piezoelectric vibrator is brought into contact with a flow path unit in which a nozzle plate having a nozzle opening for discharging ink droplets by sealing the other surface in a liquid-tight manner with the dummy piezoelectric vibrator as a positioning reference body via a head holder. The inkjet recording head according to claim 1. 9. An outer side surface of the dummy piezoelectric vibrator,
2. The ink jet recording head according to claim 1, which functions as a positioning surface for the head holder. 10. The ink jet recording head according to claim 1, wherein a block is arranged on an outer side surface of the dummy piezoelectric vibrator. 11. The ink jet recording head according to claim 10, wherein the block is thinner than the thickness of the piezoelectric vibrator and is located closer to the fixed substrate than a front end surface of the piezoelectric vibrator. 12. The ink jet recording head according to claim 10, wherein the block is made of a material having higher toughness than the piezoelectric vibrator. 13. The ink jet recording head according to claim 10, wherein said block is made of ceramic or metal. 14. The ink jet recording head according to claim 10, wherein a broken piece of the block exists outside the dummy piezoelectric vibrator. 15. A dummy vibrator is disposed at least at one end in the direction in which the piezoelectric vibrators are arranged, and a region where no internal electrode is formed is formed near a region near an outer side surface of the dummy piezoelectric vibrator. Piezoelectric vibrator unit. 16. The ink jet recording head according to claim 15, wherein the vicinity of the outer side surface of the dummy piezoelectric vibrator is formed only of the piezoelectric material. 17. A piezoelectric material in which the piezoelectric vibrator exposes a first internal electrode and a second internal electrode of different poles parallel to each other in an axial direction only at respective end faces, and wraps in a vibration region. 16. The piezoelectric vibrator unit according to claim 15, wherein the piezoelectric vibrator unit is formed as a piezoelectric vibrator having a piezoelectric constant d31 laminated with a piezoelectric element interposed therebetween. 18. The piezoelectric vibrator may expose a first internal electrode and a second internal electrode of different poles orthogonal to each other in the axial direction only on one side, respectively, and wrap them in a vibration region. 16. The piezoelectric vibrator unit according to claim 15, wherein the piezoelectric vibrator unit is formed as a piezoelectric vibrator having a piezoelectric constant d33 laminated with a material interposed therebetween. 19. The piezoelectric vibrator unit according to claim 15, wherein a broken piece exists outside the dummy piezoelectric vibrator. 20. The piezoelectric vibrator unit according to claim 15, wherein an external electrode which is electrically connected to each of said internal electrodes and connected to a signal supply means is formed. 21. The piezoelectric vibrator unit according to claim 20, wherein an external electrode formed on the dummy piezoelectric vibrator is narrower than a width of the dummy piezoelectric vibrator. 22. The piezoelectric vibrator unit according to claim 15, wherein a block is disposed on an outer side surface of the dummy piezoelectric vibrator. 23. The piezoelectric vibrator unit according to claim 22, wherein the block is thinner than a thickness of the piezoelectric vibrator and is located closer to a fixed substrate than a front end surface of the piezoelectric vibrator. 24. The ink jet recording head according to claim 22, wherein the block is made of a material having higher toughness than the piezoelectric vibrator. 25. The piezoelectric vibrator unit according to claim 22, wherein the block is made of ceramic or metal. 26. The piezoelectric vibrator unit according to claim 22, wherein a broken piece of the block exists outside the dummy piezoelectric vibrator. 27. A piezoelectric material having a predetermined size and thickness,
A step of alternately laminating the dummy piezoelectric vibrator while forming a conductive layer up to a region inside the outer cutout line, a step of firing when the lamination is completed to a predetermined thickness, and a step of connecting to the surface for connection. Forming an external electrode, fixing a non-vibration region to a fixed substrate, and driving a piezoelectric vibrator in a region where the conductive layer is formed, and forming a dummy piezoelectric vibrator in a region where the conductive layer does not exist. And a method of manufacturing a piezoelectric vibrator unit for an ink jet recording head. 28. The method of manufacturing a piezoelectric vibrator unit for an ink jet recording head according to claim 27, further comprising the step of breaking the vibrator outside the dummy vibrator. 29. A piezoelectric material having a predetermined size and thickness,
A step of alternately laminating while forming a conductive layer, a step of firing when lamination to a predetermined thickness is completed, a step of forming an external electrode for connection on the surface to form a piezoelectric diaphragm, A step of arranging blocks on both sides of the diaphragm to fix a non-vibration region to a fixed substrate; cutting the piezoelectric diaphragm to cut out a piezoelectric vibrator; and cutting out a dummy piezoelectric vibrator in the block region. And a method of manufacturing a piezoelectric vibrator unit for an ink jet recording head. 30. The method according to claim 29, wherein a side portion of the piezoelectric vibrator has a non-conductive layer. 31. The method of manufacturing a piezoelectric vibrator unit for an ink jet recording head according to claim 29, further comprising a step of breaking a block outside the block serving as the dummy vibrator.